机械电子专业英语翻译

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第一篇:机械电子专业英语翻译

Quality Control Fundamentals质量控制基本原理 Quality质量

Quality has become one of the most important consumer decision factors in the selection among competing products and services.The phenomenon is widespread, regardless of whether the consumer is an individual, an industrial organization, a retail store, a bank or financial institution, or a military defense program.Consequently, understanding and

improving quality are key factors leading to business success, growth, and enhanced competitiveness.There is a substantial return on investment from improved quality and from successfully employing quality as an integral part of overall business strategy.质量是消费者在激烈的产品和服务竞争中进行选择的一个重要因素.不管这个消费者是个人、产业组织、零售店或防务工程,这个想象是普遍存在的.因此,关注并提升质量是取得成功、发展并强化竞争力的关键因素.投资质量的提升并把质量作为经营策略的主要部分将会得到极大地回报.We may define quality in many ways.Most people have a conceptual understanding of quality as relating to one or more desirable characteristics that a product or service should possess.Although this conceptual understanding is certainly a useful starting point, we will give a more precise and useful definition.我们对质量有很多种定义.许多人在观念上把质量理解为产品或服务拥有一个或更多满意的性能.尽管这种概念性理解是有效地,我们将给出更精确、有效地定义.Quality----characteristic or property consisting of several well-defined technical and aesthetic, hence subjective, considerations;conformance to design(customer)requirement.质量-特性或性能中包含几种明确定义的技术的美学的,因此主观考虑;满足设计(顾客)需求.Quality control------detecting poor quality(nonconformance)in manufactured products and taking corrective action to eliminate it.质量控制-检测在工业产品中检测不合格的质量(不合格品)并采取纠正措施去避免.The traditional definition of quality is based on the viewpoint that products and services must meet the requirement of those who use them.Therefore, Quality means fitness for use.传统的质量定义是产品或服务必须满足使用者的需求.因此,质量就是适用度

There are two general aspects of fitness for use: quality of design and quality of conformance.适用度一般有两个方面:设计质量和一致性的质量。

Quality by design intent refers to the various grades or levels of quality that are intentionally determined by design.All goods and services are produced in various grades or levels of quality.These variations in grades or levels of quality are intentional, and, consequently, the appropriate technical term is quality of design.设计意图的质量指的是设计中故意设计的各种等级或质量等级。所有的商品和服务都是在不同的等级或质量等级中产生的。这些变化的等级或质量水平是故意的,因此,适当的技术术语称之为设计质量。

Quality of conformance refers to how well the product conforms to specifications required by design.产品质量的一致性是指如何符合规范设计的要求。

Quality of conformance is influenced by a number of factors, including the choice of manufacturing processes, the training and supervision of the workforce, the types of process controls, tests, and inspection activities that are employed, the extent to which these procedures are followed, and the motivation of the workforce to achieve quality.一致性质量受到很多因素的影响,包括生产流程的选择、员工的培训和监督,所采用的过程控制,测试,和检查活动的类型,这些程序被遵循的程度 ,激励员工来实现质量。

Unfortunately, this definition has become associated more with the conformance aspect of quality than with design.This is in part due to the lack of formal education most designers and engineers receive in quality engineering methodology.This also leads to much less focus on the customer and more of a ―conformance-to-specifications‖ approach to quality, regardless of whether the product, even when produced to standards, was actually ―fit-foruse‖ by the customer.Also, there is still a widespread belief that quality is a problem that can be dealt with solely in manufacturing, or that the only way quality can be improved is by ―gold-plating‖ the product.不幸的是,相对于设计,这个定义更多的关于质量的一致性。这部分是由于大多数设计师和工程师缺乏质量工程方法的正规教育。这也导致更少地关注客户和更多关注质量与规格一致, 无论产品,即使生产标准,实际上是“适合使用”的客户。同时,普遍仍认为,在生产制造中质量问题完全可以解决, 或者唯一的可以提高质的方式是给产品“镀金”。

We prefer a modern definition of quality: Quality is inversely proportional to variability.Note that this definition implies that if variability in the important characteristics of a product decreases, the quality of the product increases.As an example of the operational effectiveness of this definition, a few years ago, one of the automobile companies in the United States performed a comparative study of a transmission that was manufactured in a domestic plant and by a Japanese supplier.我们倾向于质量的现代定义:质量与变化成反比。请注意,这个定义意味着如果产品的重要特征的变化减少,产品的质量就会提高。举一个这个定义的操作效益的例子,几年前, 美国的一个汽车公司进行了一个在国内工厂制造过程的传输和由日本供应商制造过程的传输的比较研究。

An analysis of warranty claims and repair costs indicated that there was a striking difference between the two sources of production, with the Japanese-produced transmission having much lower costs, as shown in Fig.5.1.As part of the study to discover the cause of this difference in cost and performance, the company selected random samples of transmissions from each plant, disassembled them, and measured several critical quality characteristics.保修索赔和维修费用的分析表明,两者的生产有着显着的区别,如图5.1所示,日本制造的运输成本很低。这项研究的一部分是发现成本和表现中这种差异的原因,公司从每个工厂随机选择抽样,拆卸样本,并测量了几个关键的质量特性。

Figure 5.2 is generally representative of the results of this study.Note that the distribution of the critical characteristics for the transmissions manufactured in the United States takes up about 75% of the width of the specifications, implying that very few nonconforming units would be produced.In fact, the plant was producing at a quality level that was quite good, based on the generally accepted view of quality within the company.However, the Japanese plant produced transmissions for which the same critical characteristics take up only about 25% of the specification band.As a result, there is considerably less variability in the critical quality characteristics of the Japanese-built transmissions in comparison to those built in the United States.图5.2通常是这项研究的结果的代表。注意的是美国生产传输的临界特征的分布 占宽度规格的75%左右,这意味着不相容的产品很少。事实上, 根据公司内部的质量标准,工厂生产的质量水平很好,然而,日本工厂的生产传输的相同的临界特征规范只占用约25%的规格带。因此,日本建立的生产传输中的关键质量特征的变化要比美国的少很多。

There are two obvious questions here: Why did the Japanese do this? How did they do this? The answer to the ―why‖ question is obvious from examination of Fig.5.1.Reduced variability has directly translated into lower costs。Furthermore, the Japanese-built transmissions shifted gears more smoothly, ran more quietly, and were generally perceived by the customer as superior to those built domestically.Fewer repairs and warranty claims means less rework and the reduction of wasted time, effort, and money.Thus, quality truly is inversely proportional to variability.How did the Japanese do this? The answer lies in the systematic and effective use of the methods described in this text.这里有两个明显的问题:为什么日本人这样做呢?他们是如何做到这一点呢? 再看图5.1,“为什么”的问题的答案是显而易见的。减少的变化直接转化为低成本。此外,日本造的变速齿轮更顺畅,更安静,客户通常认为日本的变速齿轮要比国内的好。更少的维修和保修索赔意味着很少的返工,节约时间 ,精力,和金钱。因此,质量真的是与变化成反比。日本人是怎么做的呢?答案就在于系统和有效地使用本文中描述的方法。

Dimensions of Quality质量维度 The quality of a product can be described and evaluated in several ways.It is often very important to differentiate these different dimensions of quality.Garvin provides an excellent discussion of eight components or dimensions of quality.We summarize his key points concerning these dimensions of quality as follows: 一个产品的质量可以用几种方法来描述和评价。区分这些不同维度的质量往往是很重要的。加文 对于质量的八种要素做了一个很好的讨论。我们总结了他的关键点,这些尺寸的质量如下:

Performance –product does intended job

表现—产品满足特定功能 Reliability—product is available 可靠性----产品是可用的

Durability—product lasts for a reasonable time 持久性---产品能使用一个合理的时间 Serviceability—product is easy to repair/service

维护性---产品维修维护方便

Aesthetics—product has acceptable/appealing appearance

美观---产品具有可接受或吸引人的外观

Features—product has capabilities beyond basic performance 功能性---产品具有超越基本功能的功能

Perceived Quality—product & company have good reputation;measured by customer loyalty 感知质量—产品和公司在消费者中具有良好的声誉。

Conformance to Standards—product made consistent with designer intent(and consistent with industry & national standards)标准一致---制造的产品符合设计师的意图(并符合行业和国家标准)。

Quality Improvement质量的提升 Quality improvement is the reduction of variability in processes and products.Excessive variability in process performance often results in waste.For example, consider the wasted money, time, and effort that is associated with the repairs represented in Figure 5.1.Therefore, an alternate and frequently very useful definition is that quality improvement is the reduction of waste.质量改进是减少过程和产品中的变化。过程性能的过度变化往往导致浪费。例如,图5.1所反映的维修中浪费的金钱,时间和精力。因此,一个替代的,通常是非常有用的定义是,质量改进是减少浪费。

Implementing quality improvement: management must 实施质量改进:管理

Evaluate dimensions of quality as they pertain to their business objectives(assuming the objectives are defined);评估质量维度与他们的业务目标(假设定义了目标); Think strategically about quality;战略性地考虑质量;

Recognize critical role of suppliers in quality management strategies;认识到供应商在质量管理战略中的重要作用;

Recognize that everyone in the organization is responsible for quality;认识到组织中的每个人都对质量富有责任;

Recognize that statistical quality control techniques communicate both problems & solution;认识到统计质量控制技术,沟通问题和解决方案;

Implement effective quality improvement programs tailored to their business;针对他们的业务实施有效的质量改进方案;

Total quality management;全面质量管理;

Quality improvement benefits—business growth;enhanced competition;cost reduction;reduced product liability;improved productivity.质量改进的效益----业务增长;增强竞争;降低成本;减少产品债务;提高生产率。

Quality Engineering Terminology质量工程术语

Every product possesses a number of elements that jointly describe what the user or consumer thinks of as quality.These parameters are often called quality characteristics.Quality characteristics –-Physical;Sensory;Time Orientation;can be attributes or variable.每个产品都有许多描述用户或消费者心目中的质量的要素。这些参数通常被称为质量特性。

品质特性–身体;感官;时间方向;可以是属性或变量。

Quality engineering—the set of operational, managerial and engineering activities used to ensure that quality characteristics of a product are at nominal or the required levels.质量工程---一套确保产品的质量特性是在名义或所需的水平操作,管理和工程活动。

Statistical methods—applied to measurements for product’s quality characteristics, they are usually the result of the engineering design process for the product.统计方法---用于测量产品的质量特性,通常是产品的工程设计过程的结果。Quality measurement---compare measured value to nominal or target value for characteristic;values bounded by allowable limits, namely, upper specification limit(USL)and low specification limit(LSL)(determined by design engineer);values outside limits are considered to be nonconforming, hence, product is defective.质量测量——将质量的测量值与真值相比较,特征值被范围所限制,即规范上限(USL)和规范下极限(LSL)(由设计工程师决定);特征值外部限制被认为是不一致的,因此,产品是有缺陷的。

Concurrent engineering---multi-disciplinary, team-based approach to design(early in design process).并行工程---多学科,以团队为基础的设计方法(多在早期的设计过程)。

History of Quality Methodology质量方法学史

Quality always has been an integral part of virtually all products and services.However, our awareness of its importance and the introduction of formal methods for quality control and improvement have been an evolutionary development.Table 5.1 presents a timeline of some the important milestones in this evolutionary process.质量几乎一直是所有产品和服务的一个组成部分。然而,我们意识到它的重要性,并介绍了正式的质量控制和改进的方法,一直是一个进化的发展。表5.1给出了一些在这个进化过程中的重要里程碑的时间线。

A Timeline of Quality Methods质量测量方法的时间线

1700—1900 Quality was largely determined by the efforts of an individual craftsman.Eli Whitney introduces standardized, interchangeable parts to simplify assembly.质量在很大程度上取决于个人的努力。伊莱·惠特尼介绍标准化,可互换的零件以简化装配。1875 Frederick W.Taylor introduces principles of Scientific Management;division of labor &work standards;improved productivity.1875年弗雷德里克·W·泰勒 介绍了科学管理的原则;劳动分工和劳动标准;提高生产率。

1900–1930 Henry Ford—the assembly line—further refinement of work methods to improve productivity and quality;Ford developed mistake-proof assembly concepts, self-checking, and in-process inspection.亨利福特的装配线进一步细化工作方法以提高生产率和质量;福特开发的防误装配的概念,自我检查和中间验收,1924 Walter.A.Shewhart introduces the control chart concept in a Bell Laboratories technical memorandum.沃尔特在贝尔实验室的技术备忘录介绍了控制图的概念。1928 Acceptance sampling methodology is developed and refined by H.F.Dodge and H.G.Roming at Bell Labs.H.F.道奇和H.G.漫游在贝尔实验室开发和总结了验收抽样方法。1940 The U.S.War Department publishes a guide for using control charts to analyze process data.美国战争部出版了一份使用控制图来分析处理数据指南。

1946 ASQC formed to promote use of quality improvement methods for products & service.建立美国质量控制协会以促进使用产品与服务质量改进方法。

1946–1949 Deming is invited to japan by the Economic and Scientific Services Section of the U.S.War Department to help occupation forces in rebuilding Japanese industry.He was invited to give statistical quality control seminars to Japanese industry.戴明被美国国防部的经济和科学服务部邀请到日本帮助占领军重建日本工业。他被邀请给日本工业的统计质量控制开研讨会。

1951 Dr.A.V.Feigenbaum publishes the first edition of his book, Total Quality Control.G.E.P.Box & Wilson published work on designed experiments & process optimization methods.在1951年,费根鲍姆博士出版了他的第一本书---全面质量控制。威尔逊发明了工作流程优化设计和在线实验的方法。

1960s Courses in statistical quality control become widespread in industrial engineering academic programs.Zero defects(ZD)programs are introduced in certain U.S.industries.在20世纪60年代的统计质量控制的广泛的课程成为工业工程学术课程。零缺陷(ZD)计划被美国工业产业引进。

1989 Motorola’s six-sigma initiative began.摩托罗拉开始倡议六西格玛。

1990s ISO 9000 certification activities increase in U.S.industry;applicants for the Baldrige award grow steadily;many states sponsor quality awards based on the Baldrige criteria.上世纪90年代,在美国工业行业,ISO 9000认证活动增加;对波多里奇奖的申请稳步增长;许多国家赞助基于波多里奇标准的质量奖。

1995 Many undergraduate engineering programs require formal courses in statistical techniques, focusing on basic methods for process characterization and improvement.许多本科工程项目需要专注于过程特性和改进的基本方法 统计技术的正式课程。

1997 Motorola’s six-sigma approach spreads to other industries.1997年,摩托罗拉的六西格玛方法扩展到其他行业。

1998 The American Societies for Quality Control becomes the

American Society for quality, attempting to indicate the broader aspects of the quality improvement field.1998年,美国质量控制协会成为美国质量学会,其试图表明更广泛的质量改善领域。

Statistical Methods统计方法 Statistical process control(SPC): use control charts to reduce variability & maintain measure of process quality within acceptable limits, namely, upper control limit(UCL)and lower control limit(LCL).统计过程控制(SPC):使用控制图来减少变化及维持质量测量在可接受的范围内,即控制上限(UCL)和控制下限(LCL)。

Statistically designed experiment: used to discover key variables that influence quality characteristics of interest;systematically vary process controllable input factors to determine their effects on output product parameters.统计学设计的实验:用于发现影响质量特性的关键变量,系统变化的过程可控的输入因素,以确定其对输出产品参数的影响。

Process modeling: captures the relationship between input and output variable of process;statistical such as regression or time-series analyses, also, neural network techniques, used to determine the nature &magnitude of adjustments required to bring process back into control.过程建模:捕捉过程中的输入和输出变量之间的关系;统计,如回归或时间序列分析,神经网络技术,用于确定控制过程中所需调整的性质和幅度。

Acceptance sampling: inspection & classification of sampled units, selected at random, from larger batch of product(lot)for the purpose of determining disposition of lot;decision may be to accept, reject, or rework lot;emphasizes conformance to requirements approach to quality control.验收抽样: 从大批产品(很多)检查和分类抽样单位,随机选择以确定处置方式, 决定可能是接受,拒绝,或返工;强调符合要求的质量控制方法。

Manufacturing Process Characteristics制造工艺特点

Random variations----caused by variability among operators, Raw materials, machine vibrations, and environmental changes;usually uncontrollable;regarded as process noise;no particular pattern or trend.随机变化--由操作者,原材料,机器振动,和环境改变中的变化造成;通常无法控制的;被视为过程噪声;没有特定的模式或趋势。

Assignable variations---exception from normal operating conditions, e.g, operator mistakes;defective raw materials;tool failures;machine malfunctions, can be traced to specific causes.可分配的变化---从正常工作条件下,例如,操作者错误的异常;有缺陷的原料;工具失效;机器故障,都可以追溯到具体原因。

Machining processes are capable of tolerances of +_0.002 in(+_0.05), e.g, sand castings generally have tolerances of 10 to 20 times those used for machined parts.加工过程能够在(+_0.05)公差允许+-0.002,比如沙铸件的公差通常是用于加工零件的公差的10至20倍。

Total Quality Management(TQM)全面质量管理

Total quality management(TQM)is a strategy for implementing and managing quality improvement activities on an organization wide basis.TQM began in the early 1980s, with the philosophies of Deming and Juran as the focal point.It evolved into a broader spectrum of concepts and ideas, involving participative organizations and work culture, customer focus, supplier quality improvement, integration of the quality system with business goals, and many other activities to focus all elements of the organization around the quality improvement goal.Typically, organizations that have implemented a TQM approach to quality improvement have quality councils or high-level teams that deal with strategic quality initiatives, workforce-level teams that focus on routine production or business activities, and cross-functional teams that address specific quality improvement issues.全面质量管理(TQM)在组织基础中是一种实现和管理质量改进活动的战略。全面质量管理始于上世纪80年代初,随着戴明和朱兰的理念为焦点。它演变成一个涉及参与组织和工作文化,关注客户,供应商的质量改进,质量体系与业务目标的整合,以及许多其他的围绕质量改进目标的组织的所有元素的活动的概念。通常情况下,已经实施了全面质量管理方法以提升质量的组织具有处理质量的战略举措的质量委员会或者高层团队,聚焦日常生产、经营活动的劳动力水平的队伍,解决具体的质量改进问题的跨 职能团队。

机械专业词汇

Manufacturing process 制造工艺 Serviceability 维护性

Conformance to standards 标准一致 Quality engineering 质量工程 Measured value 测量值 Nominal value 真值 Multi-disciplinary 多学科的 Concurrent engineering 并行工程 Standardized parts 标准件 Six-sigma 六西格玛 LSL 下限 USL 上限

ISO9000 质量保证体系9000 Process modeling 过程建模 Process control 过程控制 TQM全面质量管理 Sand casting 沙铸件

Acceptance sampling 进料抽样实验 Assignable variation 系统变差 Critical dimension 临界大小 科技特殊句式 1.动名词做主语

Understanding and improving quality are key factors leading to business success, growth, and enhanced competitiveness.2.非谓语动词做定语

Quality----characteristic or property consisting of several well-defined technical and aesthetic, hence subjective, considerations;conformance to design(customer)requirement.3.复杂长句

This also leads to much less focus on the customer and more of a ―conformance-to-specifications‖ approach to quality, regardless of whether the product, even when produced to standards, was actually ―fit-for use‖ by the customer.4.名词短语

There are two general aspects of fitness for use: quality of design and quality of conformance.5.复杂长句 Organizations that have implemented a TQM approach to quality improvement have quality councils or high-level teams that deal with strategic quality initiatives, workforce-level teams that focus on routine production or business activities, and cross-functional teams that address specific quality improvement issues.典型句式

1.定义句式

Quality by design intent refers to the various grades or levels of quality that are intentionally determined by design.Paradigm refers to models of inquiry that guides scientific work

2.满足标准

The traditional definition of quality is based on the viewpoint that products and services must meet the requirement of those who use them.All structural steel, plate and sheet meet the requirements of certain specifications.3.比例关系

Quality is inversely proportional to variability.Al Most objects are big in proportion to the size of an atom but small in proportion to the size of the sun.4.图表所占比例

The Japanese plant produced transmissions for which the same critical characteristics take up only about 25% of the specification band.Girl students accounted for 47.3 percent of total primary school enrollment.Figure 4.2 gives the results of the experiment.5.研究表明

An analysis of warranty claims and repair costs indicated that there was a striking difference between the two sources of production.A study indicated that the successful language learners are same at many aspects.6.结论

Therefore, an alternate and frequently very useful definition is that quality improvement is the reduction of waste.It can be concluded that baud rate is very important to the telephone engineer.7.举例

For example, consider the wasted money, time, and effort that is associated with the repairs represented in Figure 5.1.For example, consultants and freelancers interviewed for this article set targets from$ 50 to$ 300 per hour.8.相关性

This definition has become associated more with the conformance aspect of quality than with design.The density of a soil is directly associated to its bearing capability.9.图表引用

Figure 5.2 is generally representative of the results of this study.Figure 4.2 gives the results of the experiment.10.It---that语句

It is often very important to differentiate these different dimensions of quality.It is evident that a well lubricated bearing turns more easily than a dry one.

第二篇:机械专业英语翻译

第一单元 极限与公差

几何精度设计是在机械制图上使用的一个三维国际工程设计语言。这个语言主要由符号组成,这些符号是清楚地定义在由美国机械工程协会出版的ASME Y14.5M-1994中。这个制图标准在北美使用和全世界都认同。它代替了更早的ANSI Y14.5M-1982标准和已经发展到几乎等同于它的ISO副本。这个标准在确定使用各种几何符号的方式和在清楚地展示设计者的意图的其他方法上是完善的。

几何精度设计的合理使用保证了工程设计想要的形状、配合和功能,没有在车间的假想或每个人都诠释不同的精细制作的笔记。几何精度设计将通过在整个工程设计、制造和品质功能中提供相同的解释,增加制造公差,提升效率和品质来节约公司花销。我们的经验表明许多设计者、车间和品质控制人员,尽管在几何精度设计工作了许多年,但还是没有完全了解要求和没有利用到几何精度设计的所有优点。

设计和生产系统,复杂性,电算化,和全球制造对准确的工程图纸提出了强制性要求。功能测量,刀具,零件尺寸和制造受益于几何精度设计。几何精度设计的学习是重要的,因为它是设计、制造过程和质量三者沟通的粘合剂。

制造,设计系统需要一个易懂的语言,否则,它是不一致的和不可用的。一门技术语言被定义为一个标准,这个被广泛使用的标准是ASME Y14.5M-1994。我们的目的是让几何精度设计和制造过程协调一致。你可以已经在计算机辅助设计课或制图课上接触到几何精度设计。

第二单元

力学概论

力学的基本概念:

力学是用来处理运动,时间和力的科学分析的分支,它由静力学和动力学组成。静力学研究静态系统的分析,这时,时间不是一个考虑的因素;动力学则是随时间变化的系统。力是通过相配合的表面传递到机器各个构件的。例如,从齿轮到轴或一个齿轮通过啮合齿传动到另一个齿轮或连杆通过轴承传到杠杆,从V带到滚轮或从凸轮到传动件。有许多理由都必须知道力的大小。力在边界及配合表面的分布必须要合理,其强度必须在构成表面的材料的工作极限内。例如,如果作用在套筒轴承上的力太大,将会把油膜挤出,并导致金属表面的胶合,过热和轴承过快失效,动力学的研究主要是确定李的大小、时间和位置。

下面将说明一下我们这方面的研究

力:我们最早的关于力的想法是源于我们对推、举和拉河中物体的需要。因此力是一个物体对另一个物体的作用。自觉对力的联系包括力作用的位置,方向和大小,这些称为力的特性。

物质:物质是一种材料或实物,如果它完全封闭则称为物体。

质量:牛顿吧质量定义为物体的数量,由体积和密度来衡量。这定义并不是很多人满意的,因为密度是单位体积的质量。通过猜想我们可以谅解牛顿,可能他并不认为那是个定义。然而,他已经认识到了一个事实,那就是所有的物体都具有不同于重量的内在性质。所以,尽管月球重量不同于地球重量,但一块月球上的岩石仍有特定不变的本质数量。这个恒定的本质数量或物质食粮就是岩石的质量。

国际单位制最大的有点事它对任何物体有且仅有一个单位。长度的单位为米,质量的单位为千克,力的单位为牛顿,时间的单位为秒等等。为了和这种特性保持一致,就要求一个给定的单位或词不能仅一个被认可的技术名称在二个物理量中使用。然而,习惯叫做“重量”的这个词已经在技术和非技术领域广泛使用,表示着物体所受的引力和其本身质量。

粒子:粒子就是指尺寸小到可以忽略的物体。

刚体:物体要么是弹性的,要么是塑性的,只要作用上力都会产生变形。当物体形变量很小时,通常将其假想为刚体,即没有变形的能力,作此假想以便简化分析。

可变形的物体,作为应力和应变是由将要分析的作用力所提供的,则刚体假说将不再适用。因此我们认为物体时可变形的。这种分析常称为弹性物体分析,兵并应用这附加的假说,即在力作用范围内,物体仍保持弹性。

牛顿定律,牛顿三大定律是:

牛顿第一定律:如果一对平衡力作用在一个质点上,那么这个质点仍将保持静止或匀速直线运动。

牛顿第二定律:如果作用在质点上的力不是平衡的,则该质点将经历一个加速度且加速度与合理大小成比例,沿合力方向。

牛顿第三定律:当一对质点相互作用,作用力与反作用力其大小相同,方向相反,作用在过二个质点的直线上。

2,力和力矩:

当一个物体从一个组成系统中聚集到一起,任意两物体间相互作用的力称为约束力。约束力使物体以特定的方式运动。作用在系统上的力称为作用力。

有的力在作用中并没有实际的物理接触。例如,电力磁力和引力。有许多,但不是大多数的力我们会涉及到。这些力是通过物理的或机械上的接触相互作用的。

力是个矢量,力的要素是:力的大小,方向和作用点。力的方向包括那条沿力的指向为方向的直线。因此力可能沿直线正向,也可能沿直线反向。二个大小相等,方向相反,作用不共线的合力。任意二个这种力作用在物体上将会形成一个力偶,力臂是作用线的垂直距离,作用和面是通过二个作用力的平面。

第三单元

简单机械

图3-1给出了直杠的三种布置情况,每个例子中F是支点;P是作用力,作用在b点上;W是载荷,作用在c点上,当杠杆处于平衡时,为P使杠杆绕f转动的趋势必须与载荷w使杠杆往反方向旋转的趋势相平衡。忽略在支点上的摩擦力,以上关系可用数学式表达为:P*BF=WX从上式可以看出,施加的作用力乘以支点到一作用点应等于另一侧的乘积,从这可以导出“机械效率”这个量,它等于载荷除以作用力:

机械效率=W/P=bf/cf

图3-1A中如果bf/cf=3,就意味着30磅的载荷能被10磅的为所平衡。如果力稍超过这个数值,杠杆将会随着为P的增大而绕点f旋转,为P比载荷W增加得更快更大,这也是机械效率,但应忽略摩擦力的作用,显然,f、c间的距离越短,杠杆的力放大八月入越大。

图3-1A的布置情况可在钳子和剪刀上找到,而图3-1B的情况可在手推车中找到,f相相当是车轮,W为载荷,力P由操作者施加在手柄上。图3-1C中,杠杆的作用于是作为一种运动放大装置,它用在脚踏板上来驱动一些小机械。脚踏板上b的小运动可在c产生大运动。

图3-1D中所示的差动滑轮就是基于杠杆原理。半径为R的轮A和半径为r的轮B固定在轴上,并可以转动。力P是由一条位于轮边缘一个槽中的绳子所提供的,载荷 W由绕在驱动轴上的绳子来提升。当驱动轴静止时,力P促使轴的转动趋势与W促使轴的转动趋势相等,且方向相反。忽略轴承摩擦力的话,力P和大轮半径R的乘积将等于载荷W与驱动轴半径的乘积:P*R=w*r 机械效率还是等于W/P,也等于轮R与驱动轴R的比值。

这种情况和杠杆类似。然而杠杆只能移动载荷很短的距离。而差动滑轮能移动开荷 的距离,只限制于线强长度。

当轮A和绳由装辐条的轮代替时,差动涔轮就仅适于从井里提升一桶桶的水。然而更重要的是差动滑轮的原理在许多工具和机械中是很显而易见的。例如,螺刀,由手提供的力作用在大半径上就能在小半径上转化出很大的力作用在螺钉上。

滑轮是一种最基本的简单机械之一。它从根本上说是由一个轮子和一个支承组成,轮子的轮边带有槽,槽上绕着柔软的绳子,而支承有如固定的或可动的轴承组,一个往下的拉力会产生一个大小相同的向上的力。图3-1E中滑轮和可动组B结合时,如果饭略摩察力的话,绳中所有点的张力P是一样的,因此在绳松开的这边给定一个向下的拉力,将可以提起这个拉力两倍的重物W,而重物W的上升速度交为绳移动速度的一半。因此机械效率为2倍,若使用种种带有固定的和可动的轴承组的滑轮组合,那机械效率将比2倍还要大。例如熟知的轴承级和滑车组合就是一种基本的力放大装置。

现在来考虑一下图3-2中楔的运动。它由力P向左边击打。当角度Q越小,摩擦力F也越小时,以r表示的分力N将会越大。对于任一楔表面的粗糙度以及对奕的摩托车擦力,如果角Q大于一个给定值,即使力P撤掉后,楔仍会保持原位或像粘住了。

可楔紧的锥度在机床主轴中常用来夹抚持切削刀具,如钻头铰刀。其它应用楔原理的机械装置有木刨,子,刀,金属世削刀具和凸轮

丝杠可以认为是楔锥在一个圆柱体上。丝杠是由在实心圆柱上切削出连续不断的槽所形成的,这些被实心材料分开的,连续的,圆周的槽称为螺纹。螺纹和槽都是螺旋形的。

如果将图3-3右侧所示的图ACC`A`H上线段AB`和BD 在左侧直径为d的圆柱上,将会形成1。5图的螺旋。其对应的轴向距离l称为导程。导程角λ是用来度量螺旋的倾斜角。

一些早期的螺钉,其切削方法类似于用展开的如图3-3左边的螺旋一条柔软的金属薄板,以右螺角形式,缠绕在圆柱形毛坯上,以便右角的一臂能平行于轴线,斜边用在圆柱上形成螺旋,用作切削螺旋槽的导向。

如果滑动无件被约束为沿平行圆柱轴线运动,如图3-3中的F,沿着轴线00`运动,它就能被圆柱体的旋转、螺旋或是拉直螺旋的平移所驱动。另一种情况,楔的运动是很明显的。如果螺帽的一部分构件F,它限制了旋转运动但轴向运动是自由的,丝杆螺帽组合将会把螺旋运动转化成

第四单元

机构

基本类型

机构的目的是为了传递运动,而不管机构有没有变更。虽然机构有许多中组成形式,但总的来说只有三种分类,如图4-1所示

图中的每种机构,杆2和杆4都是通过O点和Q点联接到杆1的。这两种机构的运动传递方式如图4-1所示:(A)通过柔性的包裹联接器传递,如皮带,绳子,缆和链条等;(B)通过直接接触传递,如用凸轮,齿轮或是摩擦轮;(C)用刚性的联接杆或联轴器传递。在各种情况中杆2都是驱动件,它以每分钟n2转的转速转动,而杆4是从动件,以每分钟n4的转速转动,对于这三种情况,杆2和杆4的转速比是由Of的长度与Qf的长度比值所决定的。图4-1A中由于点f固定与OQ的中心,所以它的速率是一个常量,在图4-1B和4-1C中,由于点f将会随着物体的转动而移动,故其速率是变化的。直接接触的物体能设计成只会摆动,如图4-1B,或只会持续转动。在所有的情况中,点f都是位于有公法线和中心线的交点上。

直接接触机构

在大多数的情况中,直接接触的表面互相之间是滑动的,并仅仅只有滑动运动。这样表面情况是很容易恶化的。而在特定的条件下,表面磨损不厉害的纯滚动接触具有更高的效率。如果其他条件满足了,物体将会以匀速传递运动。这些特定的情况在齿轮联接和凸轮联接中是很有用的。纯滚动的条件是接触点位于中心线上。

共有三种纯滚动接触的情况,当两物体是圆柱体时,公法线和中心线是重合的,所能传递的载荷是由其表面摩擦所决定的,这就是所谓的基于摩擦的滚动。对于不依赖于摩擦的驱动,其公法线一定不能穿过驱动件或从动件的中心。忽略摩擦,且两相互接触物体间的力沿着法线作用时,当力的作用线没有穿过从动件的转动枢轴线时,从动件将被主动驱动。图4-1B中的物体,接触点在P,提供主动驱动。

任一直接接触物体,其速率比的公式中唯一的变量就是图4-1B中点f的位置。因此,保持匀速或恒定速率比的条件是公法线在一些固定点上通过中心线。尽管法线可能会转动,但只要它在相同点通过中心线,速率比将会保持恒定。

对于大多数给定的物体形状或轮廓,另一物体的,轮廓都能被构造出来,用于以匀速速率传递运动。这就是共轭轮廓。其本身就是存在能传递共轭运动的数学曲线;摆线和渐进线就是其中的两种;用于齿轮轮齿中。摆线就是跟踪空间中滚动轮边缘的一点所形成的轨迹。轮齿的轮廓是跟踪小圆边缘的一点在大圆内外侧滚动所形成的轨迹。渐开线就是处于大圆的内外侧,渐开线就是跟踪小圆边缘一点沿大圆内外侧滚动所形成的轨迹。渐开线也是跟踪从圆柱体上展开的线上的一点所形成的轨迹。通过研究一对渐开线的接触能很好地理解两渐开线轮齿表面的相互作用方式。图4-2中,由基圆1和基圆2产生的两条渐开线通过点m、f和n想联接,且应注意到由于基圆2比基圆1大,渐开线便有不同的形状。

第五单元

连杆机构

连杆机构也许可以定义为实体物体或连杆的载体,其中每根杆件通过销联接(铰链)或滑动接头至少和其他两个杆件相联接。为了满足这个定义,连杆机构必须形成一个无限的封闭的链或一系列封闭的链。很明显,由很多杆联接的链与只有一个杆相比,其性能是不同的。这在机械上就提出了一个非常重要的问题,那就是为传递运动而给定机构的适应性问题。其适应性取决于杆件和街头的数量。

自由度,三杆机构(包括三杆联接在一起的)很明显是一个刚性框架;连杆之间不可能有相对运动,为了表达四杆机构中连杆的相对位置,只需知道任意两杆间的夹角。(算上固定连杆OQ,图5-1C所示机构有4个连杆,因此是四杆机构。)这个连杆机构有一个自由度。要确定五杆机构中连杆的相对位置需要两个角度,也就是它有两个自由度。

带有一个自由度的连杆机构,其运动是有约束的。例如,连杆所有点在其它连杆上的轨迹是固定而又确定的。通过假定连杆上所求轨迹是固定的,并移动与约束相协调的连杆,轨迹是很容易得到的或很容易可视化观察到。

四杆机构。当所受约束的连杆机构中的一个构件固定时,这个连杆机构将变成一个在机械中能够完成有用的机械功能的机构,在销连接的连杆机构中,输入杆(主动杆)和输出杆(从动杆)通常是以枢轴的连接方式连接到固定杆上的;这个连接杆(连接件)通常既不是输入杆,也不是输出杆。由于任意连杆都能固定。如果四种机构中,连杆都不等长,并且都有不同的输入-输出关系,那么就能得到四杆机构。这四种机构也就是所谓的基本连杆机构的转换。

当图5-1左边中最短杆a固定时,杆b和杆d就能完成整圈的旋转运动。这就是双曲柄机构。若曲柄b以恒定的速度转动,则曲柄d将以变化的速度作同向转动。双曲柄机构本身,或者和别机构联接起来时,其曲柄都能提供有用的运动效果,图中,曲柄b是主动杆,它以匀速率逆时针旋转;曲柄d为从动件;三者都能同时完成整圈的旋转运动。但当b转过150°的角度是,从动杆d只能转动50°的角度。这就是意味着从B运动到B’时,曲柄d将比b转得慢,而从B’运动到B时,d比b转得快。如果将同样比例的曲柄d联接到包装机械的主轴上,例如联接运动较慢的轴上,那它将会暂停运动或者停顿。这在必须慢速的地方将派上用场。

通过将最短杆a作为主动杆能得到四杆机构的第二种转换。如图5-1右所示,在杆a做整圈旋转运动的同时;其相对的杆,可能在杆b,c,或杆d,却只能在φ角的范围内摆动。这称为曲柄摇杆机构。它是产生带有急回动作的摆动运动的有用装置。产生急回运动的原因是:当杆a逆时针旋转时,会带动杆 c从B摆动到B’,其摆过角度为θ1,而杆c从B’摆动到B时,其摆过的角度为θ2。由于曲柄a的转速是恒定的,且θ1大于θ2,因此摇杆从右摆动到左的时间将长于其它摆动途径。只有当活动杆件沿一个方向移动,急回装置快速将杆件送回初始位置时,机械才是做有用功。

图5-1右所示的极端位置,曲柄a与连接杆b共线,且假定摇杆c为主动杆时,就必须提供方法使从动杆a通过死点。在用脚踏式操作的磨刀机上,脚踏板连接着杆c,磨刀机主轴连接着杆a,就是靠着磨刀机的角动量使杆通过死点。

在四杆机构的第三种转换中,最短杆a为连接杆,其它的杆件只能摆动,这就是双摇杆机构。

连杆机构的综合,在连杆机构中,用图形法和分析法很容易测定出杆件的位移,速度和加速度。设计或综合连杆来满足特定要求就难得多了。还没有可用的方法来设计双曲柄机构以满足给定的输入-输出的关系谱。能做的就是调查一些选定的特定结构的性能特性。并挑选出其中最佳的

在曲柄摇杆机构中,设计者能控制摇杆的摆动角度,并在一定的程度上控制急回。而曲柄和要干的位移,速度和加速度却无法关联起来。

若四杆机构中的连杆总是以相同或相反的方向转动,并且他们的转动范围远小于180°,那么就有可能将曲柄转动在3点,4点,5点或者甚至更多的位置关联起来。图形法和分析法都能建立这种关联。

第六单元 飞轮

飞轮是一个连接到机械主轴上的重的轮子,它的目的是为了抵消和减轻在机械速度上由所提供的或所需要的动力的造成的速度不均匀性引起的任何波动。飞轮也被用来测试制动器和储存可以在紧急情况下使用的能量,或者可以在快速释放时提供大的力。

抵抗一个旋转物体使其速度发生变化的办法是改变它的惯性矩。这个性质取决于对旋转轴的材料的处置上。惯性矩是与物体的每个构件的重量和它们到旋转轴的距离的平方获得的乘积成正比。普通几何形状物体的惯性矩可以在手册中得到;对于非普通的形状,它们可以由整体的积分或者通过经验来确定。从惯性矩的性质可知,一个飞轮的材质在尽可能离旋转轴远的地方集中是最有效的。因此最好的飞轮有一个通过轮辐或圆盘连接到中心轮毂重的轮缘。

一个飞轮的运行情况完全取决于扭矩或作用在它身上的转动力。如果一个顺时针的扭矩作用在一个固定的飞轮一段时间,这个飞轮将获得一个顺时针角度方向的速度,它与平均扭矩乘以时间段的积成正比,与飞轮的惯性矩成反比。如果一个旋转飞轮受到与它旋转方向相同的一个扭矩作用,它的速度将提升;反之,速度将下降。飞轮的惯性矩越大,由一个给定的扭矩引起的速度变化将越小。如果没有扭矩作用在飞轮上,它的速度将不会改变。

在一个往复式发动机的每个旋转期间作用在曲柄轴上的扭矩都会变化。这种变化是由于在汽缸中的蒸汽或气压的不均匀性和连杆(将活塞压力转变为曲柄轴扭矩)与曲柄轴之间的变化的夹角造成的。当曲柄和连杆是共线的,这时将没有扭矩传递给曲柄,每次旋转这种情况会发生两次。在发动机上飞轮的一个附带的功能是带领曲柄轴经过这些死点位置。

所有的旋转机械都构件都具有惯性矩和像飞轮一样都会对扭矩变化作出反应。这些构件启动、暂停或速度变化所需要的扭矩被称之为惯性扭矩或惯性载荷。惯性载荷存在于所有机械中,当机械启动时它们的存在尤其明显。

飞轮在间歇地传递机械功的机械上是特别有用的。例如,在冲床上,在活塞的下行冲程期间冲压或成型金属盘所需的大的力才会发生。在下行冲程的剩余时间,整个上行冲程和冲程之间的时段,机器是空转的,来自驱动马达的所需的动力是很低的。使用一个具有传递足够大的扭矩去创造冲孔成型所需的大的力的驱动马达是不经济的。飞轮作用于储存在机器空转时由低动力马达造成的能量和在下行冲程做工部分释放部分能量。

在1880年代,一个快速旋转的飞轮被用作鱼雷推动系统的动力源;据报道,在450米的距离将获得24海里/时的速度。在飞机上,直径25厘米,转速52000转/分钟的飞轮有足够的能量去升起和降下起落架。这个飞轮储能系统重90千克,低于完成相同功能的液压系统。在公交运输方面的一个近来(1970年)的应用是在无轨电车上使用飞轮的提议。新型的高密度的钢轮,重300千克,转速为每分钟20000转,它将允许电车离开电线行驶在临近十公里的区域内。在飞轮上获得高密度储能能力的关键在于由材料可以带动的旋转引起的离心应力的大小。相同的材料,平的圆盘可以比轮缘形的轮子多储能百分之50,而锥形的等压力盘可以比轮缘形的轮子多储能百分之100。

第八单元 材料的热处理

热处理是在固态下加热和冷却材料来改变它的的物理性质的工艺。根据所使用的工序,钢可以被硬化来抵抗切割运动和磨损,或者它可以被软化来进行进一步加工。结合适当的热处理,可以消除内部应力,细化晶粒,增加韧性,或生产一个韧性的内部和硬的表面的材料。直到热处理之前,在机械车间制造的大部分产物只有很少的价值或没有价值。热处理不仅可以用于钢上面,也可以用在许多非铁金属上面,例如铝,铜和黄铜。钢热处理的工序包括硬化淬火,回火,退火和表面淬火。

在许多人处理工艺上,加热的速度是重要的。热度以一定的速率从钢的外部传导到内部。如果钢加热太快,外部将会比内部更热,不会得到均匀的结构。如果工件在形状上是不规则的,为了消除变形和裂纹,缓慢的加热速度是更加必要的。工件越重,为了达到均匀的结果,加热时间必须更久。尽管已经达到了正确的温度,工件也应该保持在这个温度相当一段时间来使它最厚的截面达到相同的温度。

1硬化

硬化是一个加热和冷却的过程来增加它的硬度和拉伸强度,降低延展性,和得到一个良好的晶粒结构。这工序包括在温度的临界点加热金属,随后快速冷却。随着金属被加热,铁和碳之间发生物理和化学的改变。这个临界点或临界温度是钢具有最理想特性的点。当钢达到在1400到1600华氏度间的某个温度,如果它被快速冷却,这个变化对制出硬,又强的材料是理想的。如果金属缓慢冷却,它将会变回原本的状态。通过把热的金属投入水,油或盐水中(淬火),可以得到所想要的特性。金属对比之前是非常强和硬的和有更少的延展性。

2回火

已经通过快速淬火硬化的钢是脆的和不适合于大部分用途。通过回火,硬度和脆性将减少到耐用条件所需要的点。随着这些性质减少,钢的抗拉强度也会减小,而在延展性和韧性会增加。这个工艺包括了淬硬钢再加热到低于临界范围的某个温度,随后以任何速度冷却。虽然这个过程软化了金属,但它完全不同于退火,在这个过程中回火有助于对物理性质的精细控制,和在大部分过程中,回火不会把金属软化到退火将达到的程度。最后从硬化金属完全回火所得到的结构被称为回火马氏体。

因为硬化金属的主要成分马氏体的不稳定性,所以回火是合理的。从300到400华氏度的低温不会造成硬度降低,它主要用于消除内部应变。随着回火温度的增高,马氏体的分解将以更快的速度发生,和在大约600华氏度,变成被称为回火马氏体的结构是非常快的。

回火工艺可以被描述成沉淀和结块,或渗碳体聚结的工艺。大量渗碳体的沉淀是在600华氏度,这会产生硬度降低。温度升高会造成碳化物的聚结,而硬度会继续降低。

3退火

退火的主要目的是软化硬的钢以致使它可以被机加工和冷加工。通常这是通过加热金属到稍稍在形成奥氏体的临界温度之上,并保持这个温度直到工件的温度处处相同,和那时以一个缓慢的可控速度冷却以致使工件的表面温度和中心温度近似相等来完成的。这个过程被称为完全退火,因为它消除了之前结构的所有的痕迹,提纯了结晶结构,和软化了金属。退火也消除了以前在金属产生的内部应力。

当硬化的金属二次加热到临界范围之上,组织将变回奥氏体,和缓慢冷却,那时将提供足够的时间完成奥氏体到更软的结构的转变。对于亚共析钢,这些结构是珠光体和铁素体。通过参考平衡态图标,可以注意到过共析钢退火温度是更低的,稍稍在A线之上。没有理由去加热到A线之上,因为在这个点硬的组织渗碳体开始析出。通过加热到更低的临界范围之上和缓慢冷却,所有的马氏体会转变成珠光体。在钢里面任何自由的渗碳体都不收这些处理的影响。

第九单元 材料的选择与机械零件的强度

1材料的选择

这些年来,工程材料的选择已经显得非常重要。此外,选择过程应该是一个对材料的连续不断的重新评价过程。新材料不断出现,而一些原有的材料的可以被利用的数量可能会减少。环境污染,材料的回收利用.工人的健康及安全等方面的关心经常会对材料选择附加新的限制条件。为了减轻重量或者节约能源,可能会要求使用不同的材料,来自国内和国际的竞争.对产品维修方便性要求的提高和顾客的反馈等方面的压力。此外,材料与材料加工之间的相互依赖关系已经被人们认识得更清楚,新的加工方法的出现通常会促使人们对被加工材料进行重新评价。因此,为了能在合理的成本和确保质量的前提下获得满意的结果,设计工程师和制造工程师都必须认真仔细地选择,确定和使用材料。

制造任何产品的第一步工作都是设计,设计通常可以分为几个明确的阶段,(a)总体设计b)功能设计c)生产设计。在总体设计阶段,设计者着重考虑产品应该具有的功能。通常要设想和考虑几个方案,然后决定这种想法是否可行;如果可行,则应该对其中一个或几个方案作进一步的改进,在此阶段,关于材料选择唯一要考虑的问题是:是否有性能符合要求的材料可供选用,如果没有的话,是否有较大的把握在成本和时间都允许的限度内研制出一种新材料。

在功能设计或工程设计阶段,要做出一个切实可行的设计,在这个阶段要绘制出和相当完整的图纸,选择并确定各种零件的材料,通常要制造出样机或者实物模型,并对其进行试验,评价产品的功能,可靠性,外观和适用性等,虽然这种试验可能会表明,在产品进入到生产阶段之间,应该更换某些材料,但是,绝对不能将这一点作为不认真选择材料的借口,应该结合产品的功能,认真仔细地考虑产品外观,成本和可靠性。一个很有成就的公司在制造所有样机时,所选用的材料应该和其在生产中使用的材料相同,并尽可能使用同样的制造技术,这样做对公司是很有的。功能完备的样机如果不能根据预期的销售量经济地制造出来,或者是样机与正式生产的装置在质量和可靠性方面有很大不同,则这种样机就没有多大的价值。设计工程师最好能在这一阶段全部完成材料的分析,选择和和确定工作,而不是将其留到生产设计阶段去做。因为,在生产设计阶段材料的更换是由其他人进行的,这些人对产品的所有功能的了解可能不如设计工程师。

在生产设计阶段中,与材料有关的主要问题是应该把材料完全确定下来,使它与现有的设备相一对一,能够利用现有设备经济地进行加工,材料的数量能够比较容易地保证供应。

在制造过程中,不可避免地会出现对使用中的材料作一些更改的情况,经验表明,可以采用某些理家材料作为替代品。然而,在大多数情况下,在进行生产以后改换材料要比在开始生产前改换材料所花费的代价要高在生产设计阶段做好材料选择工作,可以避免大多数的这种材料更换情况,在生产制造开始后出现了可供使用的新材料的。当然,这些新核燃料可能降低成本,改进产品性能。但是,必须对新材料进行认真的平价,以倚其所有性能都被人们所了解。应当时刻牢记,新材料的性能和可靠性很少能像现有材料那样为人们所了解大部分的产品失效和产品责任事故案件是由于在选用新材料作为替代材料之前,没有真正了解它们的长期使用性能而引起的。

产品的责任诉讼迫使设计人员和公司在选择材料时,采用最好的程序,在材料选择过程中,五个最觉的问题为:(A)不了解或者未能利用关于材料应用方面的最新和最好的信息资料(B)未能和考虑产品可以的合理用途,如有可能,设计人员还应进一步和考虑由于产品使用方法不当造成的后果。在近年来的许多产品责任诉讼案件中,由于错误地使用产品而受到伤害的控告生产大家,并且赢得判决(C)所使用材料的数据不全或者有些数据不确定,尤其是当具长期性能数据是如此的时候(D)质量控制方法不适当和经验证明由一些完全 不称职的人员选择材料。

通过对上违一个问题的分析,可以得出这些问题是没有充分理由存在的结论,对这些问题的分析和研究以给避免这些问题的指明方向。以往采用最好的材料选择办法也不能避免发生产品责任诉讼,设计人员工业界按照适当的程序进行最佳选择,可以大减少诉讼的数量。

因为所生产的压痕尺寸的函数,这表明由于硬度是非破坏性试验,而且不需要专门的,因而硬度是一个容易测量的性能,通常可以直接在实际的机械零件上进行硬度试验。

第十单元

车床及其他机床

车床

1.车床用于旋转工件,并朝着生成所需要加工的表面方向进给切削刀具。2.最常见的车床形式是图10-1a中以图解方式显示的六角车床,它由一个支撑着床头箱,拖板和六角刀架的水平床身组成,工件夹在卡盘和夹头中,或者安装在机床主轴端部的花盘上。3.工件的旋转由一台电机通过一个齿轮系驱动主轴提供。4.切削刀具安装在横向滑板及六角刀架上,在横向滑板上的刀具在平行于工件旋转轴线方向或在工件旋转轴线的法线方向驱动或给进。六角刀架可以通过分度头将各种刀具定位并可以沿车床的床身方向驱动或给进。

5.现代六角车床由计算机控制所有工件和刀具运动,这些车床称为计算机数字控制(CNC)车床,而且刀具或横向滑板可以在水平面上的任一方向进给以使工件上产生所需的廓形。6.图10-1b说明的是通过工件旋转以及托板沿车床床身运动所产生的柱面,这一工序称为外圆车削。

7.车床设定的进给运动也就是工件每转一圈刀具移动的距离,机床的进给量f的定义是:刀具或工件每一行程或每转一圈,刀具相对于工件在进给运动的方向的位移,这样,为了车削长度为Lw的柱面,工件的转数是Lw/f,则加工时间Tm由下式给出的Tm=Lw/(fnw),式中nw是工件的旋转速度。

8.在此应当强调t,是刀具沿工件走一次(一次切削)的时间,但是,这一次通过并不意味着加工工序的完成,如果首次切削用于以高进给来去除大量材料(粗切),在操作过程中产生的力将有可能引起机床结构的明显挠曲,引起的精度损失可能需要以小进给量进一步加工(精切),使工件直径在规定的界限内并提供光滑的加工表面。由于这些原因,在粗切时常被加工成稍大一点的尺寸,留下少量材料在随后的精加工中去除。立式镗床

9.水平主轴的车床不适于车削沉重的大直径工件,否则机床主轴的轴线将不得不升高到机床操作工够不到固定刀具或固定工件的装置的高度,此外,在垂直的花盘上安装零件或在顶尖之间支撑零件会有困难,因此使用了一种与车窗相同的工作原理,但具有垂直轴线的机床并称为立式镗床(图10-2),这种机床像车床那样旋转工作并向刀具施加连续的,线性的进给运动。

10.(立式镗床)使用单刃刀具,而且进行的作业一般限于车削,端面车削和镗削。

11.便于定位大型工件的水平工件台由一个带有径向T型槽的,起夹持作用的旋转工作台构成

卧式镗床

12,这里介绍的另一种实用单刃刀具并具有旋转主运动的机床是卧式镗床(图10-3),这种机床主要用于沉重的圆柱形工件,在这种工件内有一个待加工的内圆柱形表面,一般讲,在描述机床时,使用卧式或立式来讲。两个词指的是提供主运动的机床轴(主轴)的姿态,可见,在卧式镗床中,主轴是水平的。

13,此类机床的主要特征是,工件在加工过程中保持静止,所有造型运动都施加在刀具上。最常见的加工工序是镗削,如图所示,镗削是通过旋转刀具来实现的,刀具安装在与主轴相连接的镗杆上,然后沿旋转线进给主轴,镗杆和刀具的进给是用于移动工件的机床运动只是用来给工件定位,在进行加工时一般不使用,端面车削工序可以通过使用专门刀具架(图10-4),在其旋转时径向进给刀具来实现。

此外先前推导的镗削和端车加工时间和金属切削率的公式仍将适用。刨床

14,刨床适用于在非常大的部件上加工平面,在这种机床(图10-5)上,线性运动作用在工件上,二刀具则垂直于该运动的方向进给,主运动通常利用变速马达通过齿条与齿轮传动来实现,而且进给运动是断续的工序用提供的T型槽固定在机床的工作台上,加工时间tm和金属切削率zw可以按下面公式估算:tm=bw/(fnr),式中bw是待加工面得宽度。Nr是切削行程的频率,f是进给量,金属切削率zw由下式给出zw=fapv,式中v是切削速度,ap是切口深度(去除材料层的深度)

第十一单元基本的加工工序——切削、镗削、和磨削

基本的加工工序

机床是从早期的埃及人的脚踏动力车床和约翰。威尔金森的镗床发展而来,它们用于为工件和刀具两者提供坚固的支撑并且可以精确控制它们的相对位置和相对速度。基本上讲,在金属切削中一个磨尖的楔形工具以紧凑变形的切削形式从有韧性的工件表面去除一条很窄的金属。切削是一种废弃的产品,与其他工件相比它相当短但是比未切削的部分厚度有相对的增加。机器表面的几何形状取决于刀具的形状和加工操作过程中刀具的路径。

大多数加工工序产出不同几何形状的部件。如果一个粗糙的圆柱形工件绕中心轴旋转而且刀具穿破工件表面并与旋转中心平行的方向前几,就会产生一个旋转面,这道工序叫做车削。如果以类似的方式加工一根空心管的内部,则这道工序叫镗削。制造一个直径均匀变化的锥形外表面叫做锥体车削。短的锥面或柱面也可以仿形车削。如果刀具尖端以一条半径可变的路径前进,就可以制造出像保龄球杆那种仿形表面。如果工件足够短(约1英寸)而且支撑具有足够的刚性,仿形表面可以通过进给一个垂直于旋转轴的仿形刀具来制造。

常常需要的是平坦的或平的表面。它们可以通过径向车削或端面车削来完成,期中刀具尖端沿垂直于旋转轴的方向运动。在其他情况下,更方便的是固定工件不动;以一系列直线式切削的方式使刀具横过工件作往复运动,在每次切削行程前具有一定横向进给量。这一工序叫做刨削,是在牛头刨床上进行的。对于大一些的工件,很容易保持刀具固定不动,而像龙门刨削那样在其厦门拉动工件。仿形面可以通过使用仿形刀具来制造。

在每次往复时进给刀具。也可以使用多刃刀具。钻削使用两刃刀具,孔深可达钻头直径的5~10倍。不管是钻头转动还是工件旋转,切削刃与工件间的相对运动是一个重要的因素。在铣削操作中,有许多切削刃的旋转铣刀与工件相接合,这种工件相对铣刀运动缓慢。根据铣刀的几何形状和进给的方式,可以加工出平面和仿形面。可以使用水平或垂直旋转轴,工件可以沿三个坐标方向中的任意一个进给。

基本的机床

机床用于以切削的形式从韧性材料上去除金属来加工特殊几何形状和精密尺寸的部件。切屑是废品,其变化形状从像钢这样的韧性材料的长的连续带状到铸铁形成的易于处理、彻底断掉的切屑,就处理的观点来讲,不想要长的连续带状屑。机床完成5种基本的金属切削工艺:车削,刨削,钻削,铣削和磨削。其他所有金属切削工艺都是这5种基本工艺的变形。因此,仅有4种使用专用可控几何形状的刀具的基本机床:

1、车床

2、刨床

3、钻床

4、磨床。例如:镗削是内部车削:铰削、攻丝和平底锪孔是修改已钻好的孔,与钻削有关;滚齿与切齿基本上是铣削作业;弓锯削和拉削是刨削和研磨的一种形式;而研磨、超精加工、抛光和磨光则是磨削和研磨切削加工作业的各种变化形式。磨削工艺形成碎屑,但是磨粒的几何形状不可控制。

不同加工工艺切削材料的量和速度可能很大,如在大型车削作业或极小,如研磨或超精加工作业,只有表面高出的点被去除。

机床完成3种主要功能:

1、刚性支撑工件或工件的夹具以及切削刀具;

2、提供工件与切削工具间的相对 运动;

3、提供了一定范围的进给和速度,通常每种情况有4~32种选择。加工中的速度和进给

切削速度、进给和深度是经济加工的3个主要变量,其他变量还有工件和刀具材料,冷却剂以及切削刀具的几何形状,金属切削的速率和加工所需的功率就取决于这些变量。

切削深度,进给和切削速率是在任何金属切削作业中都必须建立的机器设置,它们都会影响切削力,功率和对金属切削的速率。切削的深度是唱针进入唱片的量或者是槽的深度。切削速度由任意时刻唱片表面和对于拾音器臂内的唱针的速度来表示进给由唱针每圈径向向内的前进量或者把两个相邻槽的位置间来表示可以通过把它们与留声机的唱针和唱片相比较给出其定义。

第十二单元 计算机辅助设计

好的工程设计需要保证一个部件或机构正确的运转和持续相当长的一段时间。此外,在设计过程的功能性因素包含重量,强度,热性能,运动学和动力学。

第十五单元

柔性制造、一、柔性制造的定义

制造的演变用图表示为一个连续统一体,如图15-1所示。如此图显示的那样,制造的过程和系统处在把手工操作到最后实现全盟的集成制造的过度状态。计算机集成制造的前一步叫做柔性制造。

柔性在现代制造环境中是一个重要的特征。它意味着一个制造系统是用途多且适应性强,同时又能进行产量相对较大的制造。柔性制造系统是多用途的,这是因为它能制造多种多样的部件。它适应性强,因为它能很快地加以改变来制造完全不同的另一种部件。这种柔性在竞争激烈的国际市场上可能成败有别。

这是一个平衡的问题。独立的计算机数字控制(nc)机床有着高度的柔性,但是只能处理批量相对较小的制造。正相反,系列连锁生产线能进行批量较大的制造,但都不很灵活。柔性制造试图运用工业技术在灵活的与制造运行间达到最佳的平衡。这些工业技术包括自动化的材料、处理,成组技术及计算机和分布数字控制。

柔性制造系统(FMS)是一个独立的机床或一组机床服务于一个自动材料处理系统。它是由计算机控制的而且有对刀具处理的能力。由于他有刀具处理能力并受计算机控制,这样的系统可以不断的重新配置来制造更加多样的部件,这就是它被称作柔性制造系统的原因。

一个制造系统要成为柔性制造系统必须具备的要素有:

1、计算机控制

2、自动处理材料能力

3、刀具处理能力

柔性制造向全面集成化制造的目标迈进了重要的一部。它实现了自动制造过程的集成化。在柔性制造中,自动化的制造机器(如车床、铣床、钻床)和自动化材料处理系统之间,通过计算机网络进行即时的沟通。这是小规模的集成,图15-2是柔性制造系统的一个样例。

二、柔性制造的概况

通过综合几个自动化的制造概念,柔性制造系统向全面集成化的目标迈出了重要的一步,这些观念是:

1、独立机床的计算机数字控制

2、制造系统的分布式数字控制

3、自动化的材料处理系统

4、成组技术,零件族

当这些自动化工艺,机器和观念合成到一个集成的系统时,就产生柔性制造系统。在柔性制造系统中,和计算机起了重要作用,当然大的劳动量比手工操作的制造系统要小得很多。然而,人仍然在柔性制造系统的操作中起了至关重要的作用,人的任务包括几个方面:

1、设备故检、维护和修理

2、刀具的变换和设置

3、安装和拆卸系统

4、数据输入

5、部件程序的变换

6、程序的开发

柔性制造系统设备像所有制造设备一样,必须有人监管以免出现失常、机器程序错误,以及故障。当发现问题时检修人员必须确定问题的根源,然后给出正确的措施,人还要采取指定的措施来修理运行不正常的机器。甚至当所有系统正常运转时,定期的维护也是必要的。

操作人员还要根据需要设置机床,换刀具,以及重新配置系统。柔性制造系统的刀具处理能力消弱了,但并没有消除,在刀具变换和设置上仍需要人力。在装卸柔性制造系统时也是这样,一旦原材料被送到自动化材料处理系统上,它就会以规定的方式,在系统中移动。然而,初装到材料处理系统仍然是由人员完成的,成品的拆卸也是同样。

与计算机的交流仍需要人力完成,人开发零件程序,通过计算机控制柔性制造系统。当重新配置FMS制造另一种类型零件时,他们还在必要的时候变换程序。人在柔性制造系统中劳动力密集型的成分越来越少,但仍然是很重要的。

柔性制造系统中的各层控制都是由计算机来完成的。在柔性制造系统中独立的机床是由CNC来控制点。整个的系统是由DNC来控制的。自动化的材料处理系统是计算机来控制的,其他的功能如数据收集、系统监控、刀具控制、运输控制也是计算机控制的,人机交互是柔性制造系统中的关键。

二、柔性制造的历史发展

柔性制造产生于20世纪60年代中期,当时英国莫林斯有限公司开发了24号系统。24号系统是一个真正的FMS。然而,它从一开始就注定是失败的,因为自动化、集成化和计算机控制技术还没有发展到能够恰好支持这一系统的程度。第一个FMS是超前的开发。因此,最终因不能工作而被放弃。

在20世纪60年代和70年代的其余时间里,柔性制造仍然是一个学术观念。然而,随着复杂计算机控制技术在20世纪70年代末和80年代初的出现,柔性制造便成为可能。在美国最初的主要用户是汽车、卡车和拖拉机制造商。

四、柔性制造的理由 在制造中,生产率和柔性之间经常存在协调一致的问题。在该领域的一端是具有高生产率却低柔性的连续生产线,在该领域的另一端是能提供最大柔性的独立的计算机数字控制的机床,但它只能进行低生产率的制造。柔性制造处在此连续统一体的中间。在制造中总是需要一个系统,这个系统比单个机床能制造更大批量且用于更多制作过程,但仍保持其柔性。

连续生产线能以高生产率制造大量的零件。这条生产线需要大量的准备工作,但却能制造出大量的相同的零件。它的主要缺点是即使一个部件在设计上有小的改变都能造成整个生产线的停产和建构改变。这是一个致命的弱点,因为这意味着没有高成本,耗时停工和变化连锁生产线结构是不能制造出不同的零件的,即使是来自同一个零件族。

传统上计算机数字控制机床是用来制造少量在设计上稍有不同的零件。这种机床很适合这一用途。因为它们能迅速地改变程序来适应设计上小的或者更大的改变。然而,作为独立的机床它们不能大量地或高生产率地制造零件。

柔性制造系统比独立的计算机数控机床具有更大的生产能力和更高的生产率。它们在柔性方面比不上计算机数字控制机床,但它们却相差不多。柔性制造的中间性能的特殊意义在于大多数制造要求中等量的生产率来制造中等及的产品。同时有足够的柔性以快速改变结构来制造另一个零件或产品。柔性制造填补了制造中长期存在的空白。

柔性制造以其基本能力给制造者提供了许多有点:

1、在一个零件族内具有柔性

2、随意进给零件

3、同时制造不同的零件

第三篇:机械专业英语翻译——推荐书籍

口语猫英语 · 在家上外教课

https://kouyumao.com 机械专业英语翻译——推荐书籍

随着国际交往日益增多,我国进出口产品与日俱增。在与外方交流过程中,正确使用机械专业英语术语相当重要,否则人家听不懂你在讲什么。如“hypoid gear”,国内常用英汉词典就有译名:双曲线齿轮、准双曲面螺旋锥齿轮、准双曲面齿轮、偏轴伞齿轮、直角交错轴双曲面齿轮、海波齿轮(音译)等,不懂机械专业英语翻译的同学就会不知所措,现译名为“准双曲面齿轮”。同学们在翻译机械专业英语的学习资料时,如果翻译不准确也会发生很多问题。在进行机械专业英语翻译时小伙伴们需要结合应用场合准确翻译,比如“crossed helical gear”译为螺旋齿轮不妥,应译为“交错轴斜齿轮”、“standard pitch diameter”应译为分度圆直径而不宜译为标准节圆直径,对单个齿轮而言只有分度圆没有节圆;而“working(or operating)pitch diameter”应译为啮合节圆直径。再比如系数,在几何量上用“coefficient”,如“addendum modification coefficient”应该翻译成径向变位系数;在强度方面用“factor”,如“application factor”是使用系数的意思;“overload factor“为过载系数;”dynamic factor“为动载系数。凡此种种都要求翻译术语规范化,符合国情便于交流。

口语猫英语 · 在家上外教课

https://kouyumao.com 所以就推荐几本机械专业英语的书给有需要的小伙伴们:

1、《英

这本书主要介绍英汉机械工程常用词汇,所以在一定程度上可以帮助读者准确地阅读英文专业文献以及进行机械领域方面简单的英文交流。内容主要包括数学、数学表达式和方程式、物理学、化学、机械制图、公差与配合、理论力学、材料力学、机械原理、机械零部件、金属材料与热处理、电工学、切削加工、液压传动等等

容。

这本书的编排合理、内容实用且查询方便是一本参考性极强的工具书。

2、《图解机械制造专业英语(增强版)》 这本书具有系统、呈面、简明、形象之特色。对于已经学习过专业课程的读者来说可以温故而知“英”,而且还可以扩大已有的关于机械的知识面、开阔技术视野;对于非机类专业人士来说可以简单学习专业术语、名称并认识机械各类零件、结构、设备和加工方法,所以这本书也便于给机械初学者进行自学和应用于实际工作。这本书不仅适合作为机械类专业的大、中专院校的专业英语教材,也可供机类及非机类专业从事技术翻译、技术交流、进出口贸易等工作的各界涉外人士、工矿企业的专业技术人员学习参考。

第四篇:机械英语翻译

机械英语翻译.txt你无法改变别人,但你可以改变自己;你无法改变天气,但你可以改变心情;你无法改变生命长度,但你可以拓展它的宽度。第一单元 ? Types of Materials 材料的类型

Materials may be grouped in several ways.Scientists often classify materials by their state: solid, liquid, or gas.They also separate them into organic(once living)and inorganic(never living)materials.材料可以按多种方法分类。科学家常根据状态将材料分为:固体、液体或气体。他们也把材料分为有机材料(曾经有生命的)和无机材料(从未有生命的)。

For industrial purposes, materials are divided into engineering materials or nonengineering materials.Engineering materials are those used in manufacture and become parts of products.就工业效用而言,材料被分为工程材料和非工程材料。那些用于加工制造并成为产品组成部分的就是工程材料。

Nonengineering materials are the chemicals, fuels, lubricants, and other materials used in the manufacturing process, which do not become part of the product.非工程材料则是化学品、燃料、润滑剂以及其它用于加工制造过程但不成为产品组成部分的材料。

Engineering materials may be further subdivided into: ①Metal ②Ceramics ③Composite ④Polymers, etc.工程材料还能进一步细分为:①金属材料②陶瓷材料③复合材料 ④聚合材料,等等。? Metals and Metal Alloys 金属和金属合金

Metals are elements that generally have good electrical and thermal conductivity.Many metals have high strength, high stiffness, and have good ductility.金属就是通常具有良好导电性和导热性的元素。许多金属具有高强度、高硬度以及良好的延展性。

Some metals, such as iron, cobalt and nickel, are magnetic.At low temperatures, some metals and intermetallic compounds become superconductors.某些金属能被磁化,例如铁、钴和镍。在极低的温度下,某些金属和金属化合物能转变成超导体。

What is the difference between an alloy and a pure metal? Pure metals are elements which come from a particular area of the periodic table.Examples of pure metals include copper in electrical wires and aluminum in cooking foil and beverage cans.合金与纯金属的区别是什么?纯金属是在元素周期表中占据特定位置的元素。例如电线中的铜和制造烹饪箔及饮料罐的铝。

Alloys contain more than one metallic element.Their properties can be changed by changing the elements present in the alloy.Examples of metal alloys include stainless steel which is an alloy of iron, nickel, and chromium;and gold jewelry which usually contains an alloy of gold and nickel.合金包含不止一种金属元素。合金的性质能通过改变其中存在的元素而改变。金属合金的例子有:不锈钢是一种铁、镍、铬的合金,以及金饰品通常含有金镍合金。Why are metals and alloys used? Many metals and alloys have high densities and are used in applications which require a high mass-to-volume ratio.为什么要使用金属和合金?许多金属和合金具有高密度,因此被用在需要较高质量体积比的场合。

Some metal alloys, such as those based on aluminum, have low densities and are used in aerospace applications for fuel economy.Many alloys also have high fracture toughness, which means they can withstand impact and are durable.某些金属合金,例如铝基合金,其密度低,可用于航空航天以节约燃料。许多合金还具有高断裂韧性,这意味着它们能经得起冲击并且是耐用的。

What are some important properties of metals? Density is defined as a material’s mass divided by its volume.Most metals have relatively high densities, especially compared to polymers.金属有哪些重要特性?

密度定义为材料的质量与其体积之比。大多数金属密度相对较高,尤其是和聚合物相比较而言。

Materials with high densities often contain atoms with high atomic numbers, such as gold or lead.However, some metals such as aluminum or magnesium have low densities, and are used in applications that require other metallic properties but also require low weight.高密度材料通常由较大原子序数原子构成,例如金和铅。然而,诸如铝和镁之类的一些金属则具有低密度,并被用于既需要金属特性又要求重量轻的场合。Fracture toughness can be described as a material’s ability to avoid fracture, especially when a flaw is introduced.Metals can generally contain nicks and dents without weakening very much, and are impact resistant.A football player counts on this when he trusts that his facemask won’t shatter.断裂韧性可以描述为材料防止断裂特别是出现缺陷时不断裂的能力。金属一般能在有缺口和凹痕的情况下不显著削弱,并且能抵抗冲击。橄榄球运动员据此相信他的面罩不会裂成碎片。

Plastic deformation is the ability of bend or deform before breaking.As engineers, we usually design materials so that they don’t deform under normal conditions.You don’t want your car to lean to the east after a strong west wind.塑性变形就是在断裂前弯曲或变形的能力。作为工程师,设计时通常要使材料在正常条件下不变形。没有人愿意一阵强烈的西风过后自己的汽车向东倾斜。

However, sometimes we can take advantage of plastic deformation.The crumple zones in a car absorb energy by undergoing plastic deformation before they break.然而,有时我们也能利用塑性变形。汽车上压皱的区域在它们断裂前通过经历塑性变形来吸收能量。

The atomic bonding of metals also affects their properties.In metals, the outer valence electrons are shared among all atoms, and are free to travel everywhere.Since electrons conduct heat and electricity, metals make good cooking pans and electrical wires.金属的原子连结对它们的特性也有影响。在金属内部,原子的外层阶电子由所有原子共享并能到处自由移动。由于电子能导热和导电,所以用金属可以制造好的烹饪锅和电线。It is impossible to see through metals, since these valence electrons absorb any photons of light which reach the metal.No photons pass through.因为这些阶电子吸收到达金属的光子,所以透过金属不可能看得见。没有光子能通过金属。Alloys are compounds consisting of more than one metal.Adding other metals can affect the density, strength, fracture toughness, plastic deformation, electrical conductivity and environmental degradation.合金是由一种以上金属组成的混合物。加一些其它金属能影响密度、强度、断裂韧性、塑性变形、导电性以及环境侵蚀。

For example, adding a small amount of iron to aluminum will make it stronger.Also, adding some chromium to steel will slow the rusting process, but will make it more brittle.例如,往铝里加少量铁可使其更强。同样,在钢里加一些铬能减缓它的生锈过程,但也将使它更脆。

? Ceramics and Glasses 陶瓷和玻璃 A ceramic is often broadly defined as any inorganic nonmetallic material. By this definition, ceramic materials would also include glasses;however, many materials scientists add the stipulation that “ceramic” must also be crystalline.陶瓷通常被概括地定义为无机的非金属材料。照此定义,陶瓷材料也应包括玻璃;然而许多材料科学家添加了“陶瓷”必须同时是晶体物组成的约定。

A glass is an inorganic nonmetallic material that does not have a crystalline structure.Such materials are said to be amorphous.玻璃是没有晶体状结构的无机非金属材料。这种材料被称为非结晶质材料。Properties of Ceramics and Glasses Some of the useful properties of ceramics and glasses include high melting temperature, low density, high strength, stiffness, hardness, wear resistance, and corrosion resistance.陶瓷和玻璃的特性

高熔点、低密度、高强度、高刚度、高硬度、高耐磨性和抗腐蚀性是陶瓷和玻璃的一些有用特性。

Many ceramics are good electrical and thermal insulators.Some ceramics have special properties: some ceramics are magnetic materials;some are piezoelectric materials;and a few special ceramics are superconductors at very low temperatures.Ceramics and glasses have one major drawback: they are brittle.许多陶瓷都是电和热的良绝缘体。某些陶瓷还具有一些特殊性能:有些是磁性材料,有些是压电材料,还有些特殊陶瓷在极低温度下是超导体。陶瓷和玻璃都有一个主要的缺点:它们容易破碎。

Ceramics are not typically formed from the melt.This is because most ceramics will crack extensively(i.e.form a powder)upon cooling from the liquid state.陶瓷一般不是由熔化形成的。因为大多数陶瓷在从液态冷却时将会完全破碎(即形成粉末)。

Hence, all the simple and efficient manufacturing techniques used for glass production such as casting and blowing, which involve the molten state, cannot be used for the production of crystalline ceramics.Instead, “sintering” or “firing” is the process typically used.因此,所有用于玻璃生产的简单有效的—诸如浇铸和吹制这些涉及熔化的技术都不能用于由晶体物组成的陶瓷的生产。作为替代,一般采用“烧结”或“焙烧”工艺。

In sintering, ceramic powders are processed into compacted shapes and then heated to temperatures just below the melting point.At such temperatures, the powders react internally to remove porosity and fully dense articles can be obtained.在烧结过程中,陶瓷粉末先挤压成型然后加热到略低于熔点温度。在这样的温度下,粉末内部起反应去除孔隙并得到十分致密的物品。

An optical fiber contains three layers: a core made of highly pure glass with a high refractive index for the light to travel, a middle layer of glass with a lower refractive index known as the cladding which protects the core glass from scratches and other surface imperfections, and an out polymer jacket to protect the fiber from damage.光导纤维有三层:核心由高折射指数高纯光传输玻璃制成,中间层为低折射指数玻璃,是保护核心玻璃表面不被擦伤和完整性不被破坏的所谓覆层,外层是聚合物护套,用于保护光导纤维不受损。

In order for the core glass to have a higher refractive index than the cladding, the core glass is doped with a small, controlled amount of an impurity, or dopant, which causes light to travel slower, but does not absorb the light.为了使核心玻璃有比覆层大的折射指数,在其中掺入微小的、可控数量的能减缓光速而不会吸收光线的杂质或搀杂剂。

Because the refractive index of the core glass is greater than that of the cladding, light traveling in the core glass will remain in the core glass due to total internal reflection as long as the light strikes the core/cladding interface at an angle greater than the critical angle.由于核心玻璃的折射指数比覆层大,只要在全内反射过程中光线照射核心/覆层分界面的角度比临界角大,在核心玻璃中传送的光线将仍保留在核心玻璃中。

The total internal reflection phenomenon, as well as the high purity of the core glass, enables light to travel long distances with little loss of intensity.全内反射现象与核心玻璃的高纯度一样,使光线几乎无强度损耗传递长距离成为可能。? Composites 复合材料

Composites are formed from two or more types of materials.Examples include polymer/ceramic and metal/ceramic composites.Composites are used because overall properties of the composites are superior to those of the individual components.复合材料由两种或更多材料构成。例子有聚合物/陶瓷和金属/陶瓷复合材料。之所以使用复合材料是因为其全面性能优于组成部分单独的性能。

For example: polymer/ceramic composites have a greater modulus than the polymer component, but aren’t as brittle as ceramics.Two types of composites are: fiber-reinforced composites and particle-reinforced composites.例如:聚合物/陶瓷复合材料具有比聚合物成分更大的模量,但又不像陶瓷那样易碎。

复合材料有两种:纤维加强型复合材料和微粒加强型复合材料。Fiber-reinforced Composites Reinforcing fibers can be made of metals, ceramics, glasses, or polymers that have been turned into graphite and known as carbon fibers.Fibers increase the modulus of the matrix material.纤维加强型复合材料

加强纤维可以是金属、陶瓷、玻璃或是已变成石墨的被称为碳纤维的聚合物。纤维能加强基材的模量。

The strong covalent bonds along the fiber’s length give them a very high modulus in this direction because to break or extend the fiber the bonds must also be broken or moved.沿着纤维长度有很强结合力的共价结合在这个方向上给予复合材料很高的模量,因为要损坏或拉伸纤维就必须破坏或移除这种结合。

Fibers are difficult to process into composites, making fiber-reinforced composites relatively expensive.把纤维放入复合材料较困难,这使得制造纤维加强型复合材料相对昂贵。Fiber-reinforced composites are used in some of the most advanced, and therefore most expensive sports equipment, such as a time-trial racing bicycle frame which consists of carbon fibers in a thermoset polymer matrix.纤维加强型复合材料用于某些最先进也是最昂贵的运动设备,例如计时赛竞赛用自行车骨架就是用含碳纤维的热固塑料基材制成的。

Body parts of race cars and some automobiles are composites made of glass fibers(or fiberglass)in a thermoset matrix.竞赛用汽车和某些机动车的车体部件是由含玻璃纤维(或玻璃丝)的热固塑料基材制成的。Fibers have a very high modulus along their axis, but have a low modulus perpendicular to their axis.Fiber composite manufacturers often rotate layers of fibers to avoid directional variations in the modulus.纤维在沿着其轴向有很高的模量,但垂直于其轴向的模量却较低。纤维复合材料的制造者往往旋转纤维层以防模量产生方向变化。Particle-reinforced composites Particles used for reinforcing include ceramics and glasses such as small mineral particles, metal particles such as aluminum, and amorphous materials, including polymers and carbon black.微粒加强型复合材料

用于加强的微粒包含了陶瓷和玻璃之类的矿物微粒,铝之类的金属微粒以及包括聚合物和碳黑的非结晶质微粒。

Particles are used to increase the modulus of the matrix, to decrease the permeability of the matrix, to decrease the ductility of the matrix.An example of particle-reinforced composites is an automobile tire which has carbon black particles in a matrix of polyisobutylene elastomeric polymer.微粒用于增加基材的模量、减少基材的渗透性和延展性。微粒加强型复合材料的一个例子是机动车胎,它就是在聚异丁烯人造橡胶聚合物基材中加入了碳黑微粒。? Polymers 聚合材料

A polymer has a repeating structure, usually based on a carbon backbone.The repeating structure results in large chainlike molecules.Polymers are useful because they are lightweight, corrosion resistant, easy to process at low temperatures and generally inexpensive.聚合物具有一般是基于碳链的重复结构。这种重复结构产生链状大分子。由于重量轻、耐腐蚀、容易在较低温度下加工并且通常较便宜,聚合物是很有用的。

Some important characteristics of polymers include their size(or molecular weight), softening and melting points, crystallinity, and structure.The mechanical properties of polymers generally include low strength and high toughness.Their strength is often improved using reinforced composite structures.聚合材料具有一些重要特性,包括尺寸(或分子量)、软化及熔化点、结晶度和结构。聚合材料的机械性能一般表现为低强度和高韧性。它们的强度通常可采用加强复合结构来改善。

Important Characteristics of Polymers Size.Single polymer molecules typically have molecular weights between 10,000 and 1,000,000g/mol—that can be more than 2,000 repeating units depending on the polymer structure!聚合材料的重要特性

尺寸:单个聚合物分子一般分子量为10,000到1,000,000g/mol之间,具体取决于聚合物的结构—这可以比2,000个重复单元还多。The mechanical properties of a polymer are significantly affected by the molecular weight, with better engineering properties at higher molecular weights.聚合物的分子量极大地影响其机械性能,分子量越大,工程性能也越好。Thermal transitions.The softening point(glass transition temperature)and the melting point of a polymer will determine which it will be suitable for applications.These temperatures usually determine the upper limit for which a polymer can be used.热转换性:聚合物的软化点(玻璃状转化温度)和熔化点决定了它是否适合应用。这些温度通常决定聚合物能否使用的上限。For example, many industrially important polymers have glass transition temperatures near the boiling point of water(100℃, 212℉), and they are most useful for room temperature applications.Some specially engineered polymers can withstand temperatures as high as 300℃(572℉).例如,许多工业上的重要聚合物其玻璃状转化温度接近水的沸点(100℃, 212℉),它们被广泛用于室温下。而某些特别制造的聚合物能经受住高达300℃(572℉)的温度。

Crystallinity.Polymers can be crystalline or amorphous, but they usually have a combination of crystalline and amorphous structures(semi-crystalline).结晶度:聚合物可以是晶体状的或非结晶质的,但它们通常是晶体状和非结晶质结构的结合物(半晶体)。

Interchain interactions.The polymer chains can be free to slide past one another(thermo-plastic)or they can be connected to each other with crosslinks(thermoset or elastomer).Thermo-plastics can be reformed and recycled, while thermosets and elastomers are not reworkable.原子链间的相互作用:聚合物的原子链可以自由地彼此滑动(热可塑性)或通过交键互相连接(热固性或弹性)。热可塑性材料可以重新形成和循环使用,而热固性与弹性材料则是不能再使用的。

Intrachain structure.The chemical structure of the chains also has a tremendous effect on the properties.Depending on the structure the polymer may be hydrophilic or hydrophobic(likes or hates water), stiff or flexible, crystalline or amorphous, reactive or unreactive.链内结构:原子链的化学结构对性能也有很大影响。根据各自的结构不同,聚合物可以是亲水的或憎水的(喜欢或讨厌水)、硬的或软的、晶体状的或非结晶质的、易起反应的或不易起反应的。

第二单元

The understanding of heat treatment is embraced by the broader study of metallurgy.Metallurgy is the physics, chemistry, and engineering related to metals from ore extraction to the final product.对热处理的理解包含于对冶金学较广泛的研究。冶金学是物理学、化学和涉及金属从矿石提炼到最后产物的工程学。

Heat treatment is the operation of heating and cooling a metal in its solid state to change its physical properties.According to the procedure used, steel can be hardened to resist cutting action and abrasion, or it can be softened to permit machining.热处理是将金属在固态加热和冷却以改变其物理性能的操作。按所采用的步骤,钢可以通过硬化来抵抗切削和磨损,也可以通过软化来允许机加工。

With the proper heat treatment internal stresses may be removed, grain size reduced, toughness increased, or a hard surface produced on a ductile interior.The analysis of the steel must be known because small percentages of certain elements, notably carbon, greatly affect the physical properties.使用合适的热处理可以去除内应力、细化晶粒、增加韧性或在柔软材料上覆盖坚硬的表面。因为某些元素(尤其是碳)的微小百分比极大地影响物理性能,所以必须知道对钢的分析。Alloy steel owe their properties to the presence of one or more elements other than carbon, namely nickel, chromium, manganese, molybdenum, tungsten, silicon, vanadium, and copper.Because of their improved physical properties they are used commercially in many ways not possible with carbon steels.合金钢的性质取决于其所含有的除碳以外的一种或多种元素,如镍、铬、锰、钼、钨、硅、钒和铜。由于合金钢改善的物理性能,它们被大量使用在许多碳钢不适用的地方。The following discussion applies principally to the heat treatment of ordinary commercial steels known as plain carbon steels.With this process the rate of cooling is the controlling factor, rapid cooling from above the critical range results in hard structure, whereas very slow cooling produces the opposite effect.下列讨论主要针对被称为普通碳钢的工业用钢而言。热处理时冷却速率是控制要素,从高于临界温度快速冷却导致坚硬的组织结构,而缓慢冷却则产生相反效果。? A Simplified Iron-carbon Diagram 简化铁碳状态图

If we focus only on the materials normally known as steels, a simplified diagram is often used.如果只把注意力集中于一般所说的钢上,经常要用到简化铁碳状态图。

Those portions of the iron-carbon diagram near the delta region and those above 2% carbon content are of little importance to the engineer and are deleted.A simplified diagram, such as the one in Fig.2.1, focuses on the eutectoid region and is quite useful in understanding the properties and processing of steel.铁碳状态图中靠近三角区和含碳量高于2%的那些部分对工程师而言不重要,因此将它们删除。如图2.1所示的简化铁碳状态图将焦点集中在共析区,这对理解钢的性能和处理是十分有用的。

The key transition described in this diagram is the decomposition of single-phase austenite(γ)to the two-phase ferrite plus carbide structure as temperature drops.在此图中描述的关键转变是单相奥氏体(γ)随着温度下降分解成两相铁素体加渗碳体组织结构。

Control of this reaction, which arises due to the drastically different carbon solubility of austenite and ferrite, enables a wide range of properties to be achieved through heat treatment.控制这一由于奥氏体和铁素体的碳溶解性完全不同而产生的反应,使得通过热处理能获得很大范围的特性。To begin to understand these processes, consider a steel of the eutectoid composition, 0.77% carbon, being slow cooled along line x-x’ in Fig.2.1.At the upper temperatures, only austenite is present, the 0.77% carbon being dissolved in solid solution with the iron.When the steel cools to 727℃(1341℉), several changes occur simultaneously.为了理解这些过程,考虑含碳量为0.77%的共析钢,沿着图2.1的x-x’线慢慢冷却。在较高温度时,只存在奥氏体,0.77%的碳溶解在铁里形成固溶体。当钢冷却到727℃(1341℉)时,将同时发生若干变化。

The iron wants to change from the FCC austenite structure to the BCC ferrite structure, but the ferrite can only contain 0.02% carbon in solid solution.铁需要从面心立方体奥氏体结构转变为体心立方体铁素体结构,但是铁素体只能容纳固溶体状态的0.02%的碳。

The rejected carbon forms the carbon-rich cementite intermetallic with composition Fe3C.In essence, the net reaction at the eutectoid is austenite 0.77%C→ferrite 0.02%C+cementite 6.67%C.被析出的碳与金属化合物Fe3C形成富碳的渗碳体。本质上,共析体的基本反应是奥氏体0.77%的碳→铁素体0.02%的碳+渗碳体6.67%的碳。

Since this chemical separation of the carbon component occurs entirely in the solid state, the resulting structure is a fine mechanical mixture of ferrite and cementite.Specimens prepared by polishing and etching in a weak solution of nitric acid and alcohol reveal the lamellar structure of alternating plates that forms on slow cooling.由于这种碳成分的化学分离完全发生在固态中,产生的组织结构是一种细致的铁素体与渗碳体的机械混合物。通过打磨并在弱硝酸酒精溶液中蚀刻制备的样本显示出由缓慢冷却形成的交互层状的薄片结构。

This structure is composed of two distinct phases, but has its own set of characteristic properties and goes by the name pearlite, because of its resemblance to mother-of-pearl at low magnification.这种结构由两种截然不同的状态组成,但它本身具有一系列特性,且因与低倍数放大时的珠母层有类同之处而被称为珠光体。Steels having less than the eutectoid amount of carbon(less than 0.77%)are known as hypo-eutectoid steels.Consider now the transformation of such a material represented by cooling along line y-y’ in Fig.2.1.含碳量少于共析体(低于0.77%)的钢称为亚共析钢。现在来看这种材料沿着图2.1中y-y’ 线冷却的转变情况。

At high temperatures, the material is entirely austenite, but upon cooling enters a region where the stable phases are ferrite and austenite.Tie-line and level-law calculations show that low-carbon ferrite nucleates and grows, leaving the remaining austenite richer in carbon.在较高温度时,这种材料全部是奥氏体,但随着冷却就进入到铁素体和奥氏体稳定状态的区域。由截线及杠杆定律分析可知,低碳铁素体成核并长大,剩下含碳量高的奥氏体。

At 727℃(1341℉), the austenite is of eutectoid composition(0.77% carbon)and further cooling transforms the remaining austenite to pearlite.The resulting structure is a mixture of primary or pro-eutectoid ferrite(ferrite that formed above the eutectoid reaction)and regions of pearlite.在727℃(1341℉)时,奥氏体为共析组成(含碳量0.77%),再冷却剩余的奥氏体就转化为珠光体。作为结果的组织结构是初步的共析铁素体(在共析反应前的铁素体)和部分珠光体的混合物。

Hypereutectoid steels are steels that contain greater than the eutectoid amount of carbon.When such steel cools, as shown in z-z’ of Fig.2.1 the process is similar to the hypo-eutectoid case, except that the primary or pro-eutectoid phase is now cementite instead of ferrite.过共析钢是含碳量大于共析量的钢。当这种钢冷却时,就像图2.1的z-z’线所示,除了初步的共析状态用渗碳体取代铁素体外,其余类似亚共析钢的情况。

As the carbon-rich phase forms, the remaining austenite decreases in carbon content, reaching the eutectoid composition at 727℃(1341℉).As before, any remaining austenite transforms to pearlite upon slow cooling through this temperature.随着富碳部分的形成,剩余奥氏体含碳量减少,在727℃(1341℉)时达到共析组织。就像以前说的一样,当缓慢冷却到这温度时所有剩余奥氏体转化为珠光体。

It should be remembered that the transitions that have been described by the phase diagrams are for equilibrium conditions, which can be approximated by slow cooling.With slow heating, these transitions occur in the reverse manner.应该记住由状态图描述的这种转化只适合于通过缓慢冷却的近似平衡条件。如果缓慢加热,则以相反的方式发生这种转化。However, when alloys are cooled rapidly, entirely different results may be obtained, because sufficient time is not provided for the normal phase reactions to occur, in such cases, the phase diagram is no longer a useful tool for engineering analysis.然而,当快速冷却合金时,可能得到完全不同的结果。因为没有足够的时间让正常的状态反应发生,在这种情况下对工程分析而言状态图不再是有用的工具。? Hardening 淬火

Hardening is the process of heating a piece of steel to a temperature within or above its critical range and then cooling it rapidly.淬火就是把钢件加热到或超过它的临界温度范围,然后使其快速冷却的过程。If the carbon content of the steel is known, the proper temperature to which the steel should be heated may be obtained by reference to the iron-iron carbide phase diagram.However, if the composition of the steel is unknown, a little preliminary experimentation may be necessary to determine the range.如果钢的含碳量已知,钢件合适的加热温度可参考铁碳合金状态图得到。然而当钢的成分不知道时,则需做一些预备试验来确定其温度范围。

A good procedure to follow is to heat-quench a number of small specimens of the steel at various temperatures and observe the result, either by hardness testing or by microscopic examination.When the correct temperature is obtained, there will be a marked change in hardness and other properties.要遵循的合适步骤是将这种钢的一些小试件加热到不同的温度后淬火,再通过硬度试验或显微镜检查观测结果。一旦获得正确的温度,硬度和其它性能都将有明显的变化。

In any heat-treating operation the rate of heating is important.Heat flows from the exterior to the interior of steel at a definite rate.If the steel is heated too fast, the outside becomes hotter than the interior and uniform structure cannot be obtained.在任何热处理作业中,加热的速率都是重要的。热量以一定的速率从钢的外部传导到内部。如果钢被加热得太快,其外部比内部热就不能得到均匀的组织结构。

If a piece is irregular in shape, a slow rate is all the more essential to eliminate warping and cracking.The heavier the section, the longer must be the heating time to achieve uniform results.如果工件形状不规则,为了消除翘曲和开裂最根本的是加热速率要缓慢。截面越厚,加热的时间就要越长才能达到均匀的结果。

Even after the correct temperature has been reached, the piece should be held at that temperature for a sufficient period of time to permit its thickest section to attain a uniform temperature.即使加热到正确的温度后,工件也应在此温度下保持足够时间以让其最厚截面达到相同温度。The hardness obtained from a given treatment depends on the quenching rate, the carbon content, and the work size.In alloy steels the kind and amount of alloying element influences only the hardenability(the ability of the workpiece to be hardened to depths)of the steel and does not affect the hardness except in unhardened or partially hardened steels.通过给定的热处理所得到的硬度取决于淬火速率、含碳量和工件尺寸。除了非淬硬钢或部分淬硬钢外,合金钢中合金元素的种类及含量仅影响钢的淬透性(工件被硬化到深层的能力)而不影响硬度。

Steel with low carbon content will not respond appreciably to hardening treatment.As the carbon content in steel increases up to around 0.60%, the possible hardness obtainable also increases.含碳量低的钢对淬火处理没有明显的反应。随着钢的含碳量增加到大约0.60%,可能得到的硬度也增加。

Above this point the hardness can be increased only slightly, because steels above the eutectoid point are made up entirely of pearlite and cementite in the annealed state.Pearlite responds best to heat-treating operations;and steel composed mostly of pearlite can be transformed into a hard steel.高于此点,由于超过共析点钢完全由珠光体和退火状态的渗碳体组成,硬度增加并不多。珠光体对热处理作业响应最好;基本由珠光体组成的钢能转化成硬质钢。As the size of parts to be hardened increases, the surface hardness decreases somewhat even though all other conditions have remained the same.There is a limit to the rate of heat flow through steel.即使所有其它条件保持不变,随着要淬火的零件尺寸的增加其表面硬度也会有所下降。热量在钢中的传导速率是有限的。No matter how cool the quenching medium may be, if the heat inside a large piece cannot escape faster than a certain critical rate, there is a definite limit to the inside hardness.However, brine or water quenching is capable of rapidly bringing the surface of the quenched part to its own temperature and maintaining it at or close to this temperature.无论淬火介质怎么冷,如果在大工件中的热量不能比特定的临界速率更快散发,那它内部硬度就会受到明确限制。然而盐水或水淬火能够将被淬零件的表面迅速冷却至本身温度并将其保持或接近此温度。Under these circumstances there would always be some finite depth of surface hardening regardless of size.This is not true in oil quenching, when the surface temperature may be high during the critical stages of quenching.在这种情况下不管零件尺寸如何,其表面总归有一定深度被硬化。但油淬情况就不是如此,因为油淬时在淬火临界阶段零件表面的温度可能仍然很高。? Tempering 回火

Steel that has been hardened by rapid quenching is brittle and not suitable for most uses.By tempering or drawing, the hardness and brittleness may be reduced to the desired point for service conditions.

快速淬火硬化的钢是硬而易碎的,不适合大多数场合使用。通过回火,硬度和脆性可以降低到使用条件所需要的程度。

As these properties are reduced there is also a decrease in tensile strength and an increase in the ductility and toughness of the steel.The operation consists of reheating quench-hardened steel to some temperature below the critical range followed by any rate of cooling.随着这些性能的降低,拉伸强度也降低而钢的延展性和韧性则会提高。回火作业包括将淬硬钢重新加热到低于临界范围的某一温度然后以任意速率冷却。

Although this process softens steel, it differs considerably from annealing in that the process lends itself to close control of the physical properties and in most cases does not soften the steel to the extent that annealing would.The final structure obtained from tempering a fully hardened steel is called tempered martensite.虽然这过程使钢软化,但它与退火是大不相同的,因为回火适合于严格控制物理性能并在大多数情况下不会把钢软化到退火那种程度。回火完全淬硬钢得到的最终组织结构被称为回火马氏体。

Tempering is possible because of the instability of the martensite, the principal constituent of hardened steel.Low-temperature draws, from 300℉ to 400℉(150℃~205℃), do not cause much decrease in hardness and are used principally to relieve internal strains.由于马氏体这一淬硬钢主要成分的不稳定性,使得回火成为可能。低温回火,300℉到400℉(150℃~205℃),不会引起硬度下降很多,主要用于减少内部应变。As the tempering temperatures are increased, the breakdown of the martensite takes place at a faster rate, and at about 600℉(315℃)the change to a structure called tempered martensite is very rapid.The tempering operation may be described as one of precipitation and agglomeration or coalescence of cementite.随着回火温度的提高,马氏体以较快的速率分解,并在大约600℉(315℃)迅速转变为被称为回火马氏体的结构。回火作业可以描述为渗碳体析出和凝聚或聚结的过程。

A substantial precipitation of cementite begins at 600℉(315℃), which produces a decrease in hardness.Increasing the temperature causes coalescence of the carbides with continued decrease in hardness.渗碳体的大量析出开始于600℉(315℃),这使硬度下降。温度的上升会使碳化物聚结而硬度继续降低。

In the process of tempering, some consideration should be given to time as well as to temperature.Although most of the softening action occurs in the first few minutes after the temperature is reached, there is some additional reduction in hardness if the temperature is maintained for a prolonged time.在回火过程中,不但要考虑温度而且要考虑时间。虽然大多数软化作用发生在达到所需温度后的最初几分钟,但如果此温度维持一段延长时间,仍会有些额外的硬度下降。Usual practice is to heat the steel to the desired temperature and hold it there only long enough to have it uniformly heated.通常的做法是将钢加热到所需温度并且仅保温到正好使其均匀受热。

Two special processes using interrupted quenching are a form of tempering.In both, the hardened steel is quenched in a salt bath held at a selected lower temperature before being allowed to cool.These processes, known as austempering and martempering, result in products having certain desirable physical properties.两种采用中断淬火的特殊工艺也是回火的形式。这两种工艺中,淬硬钢在其被允许冷却前先在一选定的较低温度盐浴淬火。这两种分别被称为奥氏体回火和马氏体回火的工艺,能使产品具有特定所需的物理性能。? Annealing 退火

The primary purpose of annealing is to soften hard steel so that it may be machined or cold worked.退火的主要目的是使坚硬的钢软化以便机加工或冷作。

This is usually accomplished by heating the steel too slightly above the critical temperature, holding it there until the temperature of the piece is uniform throughout, and then cooling at a slowly controlled rate so that the temperature of the surface and that of the center of the piece are approximately the same.通常是非常缓慢地将钢加热到临界温度以上,并将其在此温度下保持到工件全部均匀受热,然后以受控的速率慢慢地冷却,这样使得工件表面和内部的温度近似相同。

This process is known as full annealing because it wipes out all trace of previous structure, refines the crystalline structure, and softens the metal.Annealing also relieves internal stresses previously set up in the metal.这过程被称为完全退火,因为它去除了以前组织结构的所有痕迹、细化晶粒并软化金属。退火也释放了先前在金属中的内应力。

The temperature to which a given steel should be heated in annealing depends on its composition;for carbon steels it can be obtained readily from the partial iron-iron carbide equilibrium diagram.When the annealing temperature has been reached, the steel should be held there until it is uniform throughout.给定的钢其退火温度取决于它的成分;对碳钢而言可容易地从局部的铁碳合金平衡图得到。达到退火温度后,钢应当保持在此温度等到全部均匀受热。This usually takes about 45min for each inch(25mm)of thickness of the largest section.For maximum softness and ductility the cooling rate should be very slow, such as allowing the parts to cool down with the furnace.The higher the carbon content, the slower this rate must be.加热时间一般以工件的最大截面厚度计每英寸(25mm)大约需45min。为了得到最大柔软性和延展性冷却速率应该很慢,比如让零件与炉子一起冷下来。含碳量越高,冷却的速率必须越慢。

The heating rate should be consistent with the size and uniformity of sections, so that the entire part is brought up to temperature as uniformly as possible.加热的速率也应与截面的尺寸及均匀程度相协调,这样才能使整个零件尽可能均匀地加热。? Normalizing and Spheroidizing 正火和球化

The process of normalizing consists of heating the steel about 50℉ to 100℉(10℃~40℃)above the upper critical range and cooling in still air to room temperature.正火处理包括先将钢加热到高于上临界区50℉到100℉(10℃~40℃)然后在静止的空气中冷却到室温。

This process is principally used with low-and medium-carbon steels as well as alloy steels to make the grain structure more uniform, to relieve internal stresses, or to achieve desired results in physical properties.Most commercial steels are normalized after being rolled or cast.退火主要用于低碳钢、中碳钢及合金钢,使晶粒结构更均匀、释放内应力或获得所需的物理特性。大多数商业钢材在轧制或铸造后都要退火。

Spheroidizing is the process of producing a structure in which the cementite is in a spheroidal distribution.If steel is heated slowly to a temperature just below the critical range and held there for a prolonged period of time, this structure will be obtained.球化是使渗碳体产生成类似球状分布结构的工艺。如果把钢缓慢加热到恰好低于临界温度并且保持较长一段时间,就能得到这种组织结构。

The globular structure obtained gives improved machinability to the steel.This treatment is particularly useful for hypereutectoid steels that must be machined.所获得的球状结构改善了钢的可切削性。此处理方法对必须机加工的过共析钢特别有用。? Surface Hardening 表面硬化 Carburizing The oldest known method of producing a hard surface on steel is case hardening or carburizing.Iron at temperatures close to and above its critical temperature has an affinity for carbon.渗碳

最早的硬化钢表面的方法是表面淬火或渗碳。铁在靠近并高于其临界温度时对碳具有亲合力。

The carbon is absorbed into the metal to form a solid solution with iron and converts the outer surface into high-carbon steel.The carbon is gradually diffused to the interior of the part.The depth of the case depends on the time and temperature of the treatment.碳被吸收进金属与铁形成固溶体使外表面转变成高碳钢。碳逐渐扩散到零件内部。渗碳层的深度取决于热处理的时间和温度。

Pack carburizing consists of placing the parts to be treated in a closed container with some carbonaceous material such as charcoal or coke.It is a long process and used to produce fairly thick cases of from 0.03 to 0.16 in.(0.76~4.06mm)in depth.固体渗碳的方法是将要处理的零件与木炭或焦炭这些含碳的材料一起放入密闭容器。这是一个较长的过程,用于产生深度为0.03到0.16 英寸(0.76~4.06mm)这么厚的硬化层。Steel for carburizing is usually a low-carbon steel of about 0.15% carbon that would not in itself responds appreciably to heat treatment.In the course of the process the outer layer is converted into high-carbon steel with a content ranging from 0.9% to 1.2% carbon.用于渗碳的一般是含碳量约为0.15%、本身不太适合热处理的低碳钢。在处理过程中外层转化为含碳量从0.9%到1.2%的高碳钢。

A steel with varying carbon content and, consequently, different critical temperatures requires a special heat treatment.含碳量变化的钢具有不同的临界温度,因此需要特殊的热处理。

Because there is some grain growth in the steel during the prolonged carburizing treatment, the work should be heated to the critical temperature of the core and then cooled, thus refining the core structure.The steel should then be reheated to a point above the transformation range of the case and quenched to produce a hard, fine structure.由于在较长的渗碳过程中钢内部会有些晶粒生长,所以工件应该加热到核心部分的临界温度再冷却以细化核心部分的组织结构。然后重新加热到高于外层转变温度再淬火以生成坚硬、细致的组织结构。

The lower heat-treating temperature of the case results from the fact that hypereutectoid steels are normally austenitized for hardening just above the lower critical point.A third tempering treatment may be used to reduce strains.由于恰好高于低临界温度通常使过共析钢奥氏体化而硬化,所以对外层采用较低的热处理温度。第三次回火处理可用于减少应变。Carbonitriding Carbonitriding, sometimes known as dry cyaniding or nicarbing, is a case-hardening process in which the steel is held at a temperature above the critical range in a gaseous atmosphere from which it absorbs carbon and nitrogen.碳氮共渗

碳氮共渗,有时也称为干法氰化或渗碳氮化,是一种表面硬化工艺。通过把钢放在高于临界温度的气体中,让它吸收碳和氮。

Any carbon-rich gas with ammonia can be used.The wear-resistant case produced ranges from 0.003 to 0.030 inch(0.08~ 0.76mm)in thickness.An advantage of carbonitriding is that the hardenability of the case is significantly increased when nitrogen is added, permitting the use of low-cost steels.可以使用任何富碳气体加氨气,能生成厚度从0.003到0.030英寸(0.08~ 0.76mm)的耐磨外层。碳氮共渗的优点之一是加入氮后外层的淬透性极大增加,为使用低价钢提供条件。Cyaniding Cyaniding, or liquid carbonitriding as it is sometimes called, is also a process that combines the absorption of carbon and nitrogen to obtain surface hardness in low-carbon steels that do not respond to ordinary heat treatment.氰化

氰化,有时称为液体碳氮共渗,也是一种结合了吸收碳和氮来获得表面硬度的工艺,它主要用于不适合通常热处理的低碳钢。

The part to be case hardened is immersed in a bath of fused sodium cyanide salts at a temperature slightly above the Ac1 range, the duration of soaking depending on the depth of the case.The part is then quenched in water or oil to obtain a hard surface.需表面硬化的零件浸没在略高于Ac1温度熔化的氰化钠盐溶液中,浸泡的持续时间取决于硬化层的深度。然后将零件在水或油中淬火。Case depths of 0.005 to 0.015in.(0.13~0.38mm)may be readily obtained by this process.Cyaniding is used principally for the treatment of small parts.通过这样处理可以容易地获得0.005到0.015英寸(0.13~0.38mm)的硬化深度。氰化主要用于处理小零件。Nitriding Nitriding is somewhat similar to ordinary case hardening, but it uses a different material and treatment to create the hard surface constituents.渗氮

渗氮有些类似普通表面硬化,但它采用不同的材料和处理方法来产生坚硬表面成分。In this process the metal is heated to a temperature of around 950℉(510℃)and held there for a period of time in contact with ammonia gas.Nitrogen from the gas is introduced into the steel, forming very hard nitrides that are finely dispersed through the surface metal.这种工艺中金属加热到约950℉(510℃),然后与氨气接触一段时间。氨气中的氮进入钢内,形成细微分布于金属表面又十分坚固的氮化物。Nitrogen has greater hardening ability with certain elements than with others, hence, special nitriding alloy steels have been developed.氮与某些元素的硬化能力比其它元素大,因此开发了专用的渗氮合金钢。

Aluminum in the range of 1% to 1.5% has proved to be especially suitable in steel, in that it combines with the gas to form a very stable and hard constituent.The temperature of heating ranges from 925℉ to 1,050℉(495℃~565℃).在钢中含铝1%到1.5%被证明特别合适,它能与氨气结合形成很稳定坚固的成分。其加热温度范围为925℉到1,050℉(495℃~565℃)。

Liquid nitriding utilizes molten cyanide salts and, as in gas nitriding, the temperature is held below the transformation range.Liquid nitriding adds more nitrogen and less carbon than either cyaniding or carburizing in cyanide baths.液体渗氮利用熔化的氰化物盐,就像气体渗氮,温度保持在低于转化范围内。液体渗氮时在氰化物溶液中加入比氰化及渗碳都较多的氮和较少的碳。

Case thickness of 0.001 to 0.012in.(0.03~0.30mm)is obtained, whereas for gas nitriding the case may be as thick as 0.025 in.(0.64mm).In general the uses of the two-nitriding processes are similar.液体渗氮可以获得厚度为0.001到0.012英寸(0.03~0.30mm)的硬化层,然而气体渗氮则能获得厚0.025英寸(0.64mm)的硬化层。一般而言两种渗氮方法的用途是类似的。

Nitriding develops extreme hardness in the surface of steel.This hardness ranges from 900 to 1,100 Brinell, which is considerably higher than that obtained by ordinary case hardening.渗氮在钢表面获得远远超出正常标准的硬度。其硬度范围为900到1,100布氏硬度,这远高于普通表面硬化所获得的硬度。

Nitriding steels, by virtue of their alloying content, are stronger than ordinary steels and respond readily to heat treatment.It is recommended that these steels be machined and heat-treated before nitriding, because there is no scale or further work necessary after this process.由于渗氮钢的合金比例,它们比普通钢更强,也容易热处理。建议对这种钢在渗氮前先机加工和热处理,因为渗氮后没有剥落并不需要更多的加工。

Fortunately, the interior structure and properties are not affected appreciably by the nitriding treatment and, because no quenching is necessary, there is little tendency to warp, develop cracks, or change condition in any way.The surface effectively resists corrosive action of water, saltwater spray, alkalies, crude oil, and natural gas.值得庆幸的是由于渗氮处理一点都不影响内部结构和性能,也无需淬火,所以几乎没有任何产生翘曲、裂缝及变化条件的趋势。这种表面能有效地抵御水、盐雾、碱、原油和天然气的腐蚀反应。

第八单元

Grinding is a manufacturing process that involves the removal of metal by employing a rotating abrasive wheel.The latter simulates a milling cutter with an extremely large number of miniature cutting edges.磨削是通过采用旋转磨轮去除金属的制造工艺。磨轮用非常大量的微型切削刃模仿铣刀进行切削。

Generally, grinding is considered to be a finishing process that is usually used for obtaining high-dimensional accuracy and better surface finish.Grinding can be performed on flat, cylindrical, or even internal surfaces by employing specialized machine tools, which are referred to as grinding machines.一般而言,磨削被认为是一种通常用于获得高尺寸精度和较好表面光洁度的精加工作业。磨削通过采用被称为磨床的特殊机床能在平面、圆柱面甚至内表面上进行。

Obviously, grinding machines differ in construction as well as capabilities, and the type to be employed is determined mainly by the geometrical shape and nature of the surface to be ground, e.g., cylindrical surfaces are ground on cylindrical grinding machines.显然,磨床根据结构和功能的不同有所区别,使用何种形式的磨床主要取决于被磨削表面的几何形状和物理性质。例如,圆柱面在外圆磨床上磨削。? Type of Grinding Operations 磨削作业的类型

1.Surface grinding.As the name surface grinding suggests, this operation involves grinding of flat or plane surfaces.Fig.8.1 indicates the two possible variations, either a horizontal or vertical machine spindle.1.表面磨削:就像其名称暗示的那样,表面磨削和平面磨削直接有关。图8.1表示了两种可能的变化:卧式磨床主轴或立式磨床主轴。

In the first case(horizontal spindle), the machine usually has a planer-type reciprocating table on which the workpiece is held.However, grinding machines with vertical spindles can have either a planer type table like that of the horizontal-spindle machine or a rotating worktable.在第一种情况(卧式主轴),卧式磨床通常具有安装工件的刨床式往复工作台。而立式主轴磨床既可以像卧式主轴磨床那样具有刨床式工作台也可以具有旋转工作台。

Also, the grinding action in this case is achieved by the end face of the grinding wheel(Fig.8.1b), contrary to the case of horizontal-spindle machines, where the workpieces ground by the periphery of the grinding wheel.而且在这种情况下,磨削动作是通过砂轮端面完成的(图8.1b),这与通过砂轮周边磨削工件的卧式主轴磨床正好相反。

Fig.8.1a and b also indicate the equations to be used for estimating the different parameters of the grinding operation, such as the machining time and the rate of metal removal.图8.1a和b同时简述了用于估计诸如加工时间和金属去除率之类的磨削作业不同参数的方程式。During the surface-grinding operations, heavy workpieces are either held in fixtures or clamped on the machine table by strap clamps and the like, whereas smaller workpieces are usually held by magnetic chucks.在平面磨削时,重的工件用夹具固定或用压板等夹紧在磨床工作台上,而小的工件则通常是用电磁卡盘固定的。

2.Cylindrical grinding.In cylindrical grinding, the workpiece is held between centers during the grinding operation, and the wheel rotation is the source and cause for the rotary cutting motion, as shown in Fig.8.2.In fact, cylindrical grinding can be carried out by employing any of the following methods: 2.圆柱面磨削:在圆柱面磨削中,作业时工件支撑在两顶尖之间,砂轮转动是导致回转切削运动的动力源,如图8.2所示。实际上,圆柱面磨削能通过采用下列任意方法来实现:(1)The transverse method, in which both the grinding wheel and the workpiece rotate and longitudinal linear feed is applied to enable grinding of the whole length.The depth of cut is adjusted by the cross feed of the grinding wheel into the workpiece.(1)横向方法:这种方法中砂轮与工件均旋转且采用线性纵向进给以保证能磨削整个长度。切削深度通过改变砂轮对工件的横向进给来进行调整。

(2)The plunge-cut method, in which grinding is achieved through the cross feed of the grinding wheel and no axial feed is applied.As you can see, this method can be applied only when the surface to be ground is shorter than the width of the grinding wheel used.(2)插入-切削方法:这种方法通过砂轮的横向进给完成磨削而不采用轴向进给。正如料想的那样,这种方法只在要磨削表面比所用砂轮宽度短时才使用。(3)The full-depth method, which is similar to the transverse method except that the grinding allowance is removed in a single pass.This method is usually recommended when grinding short rigid shafts.(3)全深度方法:这种方法除了一次加工就能去除磨削余量外其它与横向方法相同。这种方法通常在磨削较短刚性轴时推荐使用。

Internal grinding.Internal grinding is employed for grinding relatively short holes, as shown in Fig.8.3.The workpiece is held in a chuck or a special fixture.Both the grinding wheel and the workpiece rotate during the operation and feed is applied in the longitudinal direction.内表面磨削:内表面磨削用于相对较短的孔,如图8.3所示。工件安装在卡盘或特殊夹具上。作业时砂轮和工件都回转并且采用纵向进给。

Any desired depth of cut can be obtained by the cross feed of the grinding wheel.A variation from this type is planetary internal grinding, which is recommended for heavy workpieces that cannot be held in chucks.通过砂轮的横向进给能得到任意所需的切削深度。这种方法的一个变体是行星式内表面磨削,当工件较重不能用卡盘固定时推荐使用。

In that case, the grinding wheel not only spins around its own axis but also rotates around the centerline of the hole that is being ground.在这种情况下,砂轮不但绕自身轴线回转,同时还绕被磨削孔的中心线旋转。

Centerless grinding.Centerless grinding involves passing a cylindrical workpiece, which is supported by a rest blade, between two wheels, i.e., the grinding wheel and the regulating or feed wheel.无心磨削:无心磨削用于加工圆柱形工件,工件由托板支撑,在两轮即砂轮和调节或进给轮之间通过去。The grinding wheel does the actual grinding, while the regulating wheel is responsible for rotating the workpiece as well as generating the longitudinal feed.This is possible because of the frictional characteristics of that wheel, which is usually made of rubber-bonded abrasive.砂轮完成实际磨削,而调节轮负责旋转工件和产生纵向进给。由于调节轮通常用橡胶粘结的磨料制成,其摩擦特性使这成为可能。

As can be seen in Fig.8.4, the axis of the regulating wheel is tilted at a slight angle with the axis of the grinding wheel.Consequently, the peripheral velocity of the regulating wheel can be resolved into two components, namely, workpiece rotational speed and longitudinal feed.正如在图8.4中所看到的那样,调节轮的轴与砂轮轴倾斜一个微小角度。因此调节轮的圆周速度可以分解为两个分量,即工件回转速度和纵向进给。These can be given by the following equations: Vworkpiece=Vregulating wheel×cosα Axial feed=Vregulating wheel×c×sinα

Where c is a constant coefficient to account for the slip between the workpiece and the regulating wheel(c=0.94~0.98).其值可由下列公式给出:

V工件=V调节轮×cosα

轴向进给=V调节轮×c×sinα 式中c是考虑工件和调节轮之间滑动的恒定系数(c=0.94~0.98)。

The velocity of the regulating wheel is controllable and is used to achieve any desired rotational speed of the workpiece.The angleαis usually taken from 1°to 5°and the larger the angle, the larger the longitudinal feed would be.调节轮的速度是可控的并被用于实现工件任意所需的转动速度。α角通常取1到 5°,这角度越大则纵向进给也将越大。

Whenαis taken as 0°, i.e., the two axes of the grinding and regulating wheels are parallel, there is no longitudinal feed of the workpiece.当α取0°时,即砂轮和调节轮轴线平行时,则工件没有纵向进给。? Grinding Wheels 砂轮

Grinding wheels are composed of abrasive grains having similar size and a binder.The actual grinding process is performed by the abrasive grains.Pores between the grains within the binder enable the grains to act as separate single-point cutting tools.砂轮由具有相近尺寸的磨料颗粒和粘合剂组成。实际磨削作业由磨粒完成。在粘合剂中磨粒之间的孔隙使磨粒能象独立的单刃切削刀具一样工作。

These pores also provide space for the generated chips, thus preventing the wheel from clogging.In addition, pores assist the easy flow of coolants to enable efficient and prompt removal of the heat generated during the grinding process.这些孔隙同时还为产生的切屑提供空间以防砂轮堵塞。另外孔隙帮助冷却液容易流动,从而使在磨削作业中产生的热量能有效而迅速地散发。Grinding wheels are identified based on their shape and size, kind of abrasive, grain size, binder, grade(hardness), and structure.砂轮根据它们的形状和尺寸、磨料的类型、磨粒的大小、粘合剂、等级(硬度)和结构组织来分类。

Shape and size of grinding wheels.Grinding wheels differ in shape and size, depending upon the purpose for which they are to be used.Various shapes are shown in Fig.8.5 and include the following types: 砂轮的形状和尺寸:根据砂轮的用途,它们的形状和尺寸是不同的。各种形状如图8.5所示,其中包括:

1)Straight wheels used for surface, cylindrical, internal, and centerless grinding.2)Bevelled-face or tapered wheels used for grinding threads, gear teeth, and the like.3)Straight recessed wheels for cylindrical grinding and facing.1)用于表面、圆柱面、内部和无心磨削的直轮。2)用于磨削螺纹、齿轮轮齿之类的斜面或锥形轮。3)用于圆柱面和端面磨削的直凹轮。

4)Abrasive disks for cutoff and slotting operations.(thickness 0.02 up to 0.2in.(0.5 to 5mm)).5)Cylinders, straight cups, and flaring cups are used for surface grinding with the end face of the wheel.4)用于切断和开槽作业的砂轮片(其厚度从0.02到0.2英寸(0.5到5毫米))。5)用其端面进行表面磨削的圆柱、直杯及外展杯状砂轮。

The main dimensions of a grinding wheel are the outside diameter D, the bore diameter d, and the height H.These dimensions vary widely, depending upon the grinding process for which the wheel is to be used.砂轮的主要尺寸有外径D、孔径d和厚度H。根据采用砂轮的磨削工艺,这些尺寸变化很大。

Kind of abrasive.Grinding wheels can be made of natural abrasives such as quartz, emery, and corundum or of industrially prepared chemical compounds such as aluminum oxide or silicon carbide(known as carborundum).磨料的类型:砂轮可以由象石英、金刚砂、刚玉之类的自然磨料制成,或者由象氧化铝或碳化硅(也称人造金刚砂)之类的工业制备的化学化合物制成。

Generally, silicon carbide grinding wheels are used when grinding low-tensile-strength materials like cast iron, whereas aluminum oxide wheels are employed for grinding high-strength metals such as alloy steel, hardened steel, and the like.当磨削象铸铁类低拉伸强度材料时,一般采用碳化硅砂轮,而磨削合金钢、淬火钢等高强度金属则要用氧化铝砂轮。

Grain size of abrasive used.As you may expect, the grain size of the abrasive particles of the wheel plays a fundamental role in determining the quality of ground surface obtained.所用磨粒的尺寸:正如料想的那样,砂轮磨粒的尺寸对决定所得磨削表面的质量起着根本的作用。

The finer the grains, the smoother the ground surface is.Therefore, coarse-grained grinding wheels are used for roughing operations, whereas fine-grained wheels are employed in final finishing operations.磨粒越细,磨削表面越光滑。所以,粗粒砂轮用于粗加工,而细粒砂轮则用于最后精加工。The grade of the bond.The grade of the bond is actually an indication of the resistance of the bond to pulling off the abrasive grains from the grinding wheel.Generally, wheels having hard grades are used for grinding soft materials and vice versa.粘结体的等级:粘结体的等级实际上是其抵抗将磨粒从砂轮上拉脱的指标。一般而言,具有较硬等级的砂轮用于磨削较软材料,反之亦然。

If a hard-grade wheel were to be used for grinding a hard material, the dull grains would not be pulled off from the bond quickly enough, thus impeding the self-dressing process of the surface of the wheel and finally resulting in clogging of the wheel and burns on the ground surface.如果较硬等级的砂轮用于磨削较硬材料,磨钝的磨粒将不能足够快地脱离粘结体,这会妨碍砂轮表面的自修复,最终导致砂轮的堵塞并在被磨表面留下灼斑。

In fact, the cutting properties of all grinding wheels must be restored periodically by dressing with a cemented carbide roller or a diamond tool to give the wheel the exact desired shape and remove all worn abrasive grains.实际上,所有砂轮的磨削性能都必须定期地通过使用硬质合金滚轮或金刚石修整器修整而被恢复,以求很准确地把砂轮加工成要求的形状,并去除已磨钝的磨粒。

Structure.Structure refers to the amount of void space between the abrasive grains.When grinding softer metals, larger void space are needed to facilitate the flow of the removed chips.结构组织:结构组织与磨粒间的空隙量有关。当磨削较软金属时,需要较大的空隙以便去除切屑的流动。

The binder.Abrasive particles are bonded together in many different ways.These include bond, silicate, rubber, resinoid, shellac, and oxychloride.Nevertheless, the bond is the most commonly used one.粘合剂:磨粒可用多种不同方法粘结在一起。其中包括粘合剂、硅酸盐、橡胶、树脂、虫胶和氯氧化物。然而,粘合剂是最常用的。

In fact, the standard marking system is employed for distinguishing grinding wheels, by providing all the preceding parameters in a specific sequence.在实际生产中,为了区分砂轮采用标准标注系统,通过用一特定顺序将所有上述参数都表示出来。

第十一单元

? The Lathe and Its Construction 车床及其结构

A lathe is a machine tool used primarily for producing surfaces of revolution and flat edges.车床是主要用于生成旋转表面和平整边缘的机床。

Based on their purpose, construction, number of tools that can simultaneously be mounted, and degree of automation, lathes-or, more accurately, lathe-type machine tools can be classified as follows: 根据它们的使用目的、结构、能同时被安装刀具的数量和自动化的程度,车床—或更确切地说是车床类的机床,可以被分成以下几类:

(1)Engine lathes(2)Toolroom lathes(3)Turret lathes(4)Vertical turning and boring mills(5)Automatic lathes(6)Special-purpose lathes(1)普通车床(2)万能车床(3)转塔车床(4)立式车床(5)自动车床(6)特殊车床

In spite of that diversity of lathe-type machine tools, they all have common features with respect to construction and principle of operation.These features can best be illustrated by considering the commonly used representative type, the engine lathe.Following is a description of each of the main elements of an engine lathe, which is shown in Fig.11.1.虽然车床类的机床多种多样,但它们在结构和操作原理上具有共同特性。这些特性可以通过普通车床这一最常用的代表性类型来最好地说明。下面是关于图11.1所示普通车床的主要部分的描述。

Lathe bed.The lathe bed is the main frame, involving a horizontal beam on two vertical supports.It is usually made of grey or nodular cast iron to damp vibrations and is made by casting.车床床身:车床床身是包含了在两个垂直支柱上水平横梁的主骨架。为减振它一般由灰铸铁或球墨铸铁铸造而成。

It has guideways to allow the carriage to slide easily lengthwise.The height of the lathe bed should be appropriate to enable the technician to do his or her job easily and comfortably.它上面有能让大拖板轻易纵向滑动的导轨。车床床身的高度应适当以让技师容易而舒适地工作。

Headstock.The headstock is fixed at the left hand side of the lathe bed and includes the spindle whose axis is parallel to the guideways(the slide surface of the bed).The spindle is driven through the gearbox, which is housed within the headstock.主轴箱:主轴箱固定在车床床身的左侧,它包括轴线平行于导轨的主轴。主轴通过装在主轴箱内的齿轮箱驱动。The function of the gearbox is to provide a number of different spindle speeds(usually 6 up to 18 speeds).Some modern lathes have headstocks with infinitely variable spindle speeds, which employ frictional ,electrical ,or hydraulic drives.齿轮箱的功能是给主轴提供若干不同的速度(通常是6到18速)。有些现代车床具有采用摩擦、电力或液压驱动的无级调速主轴箱。The spindle is always hollow, i.e., it has a through hole extending lengthwise.Bar stocks can be fed through that hole if continuous production is adopted.主轴往往是中空的,即纵向有一通孔。如果采取连续生产,棒料能通过此孔进给。Also, that hole has a tapered surface to allow mounting a plain lathe center.The outer surface of the spindle is threaded to allow mounting of a chuck, a face plate, or the like.同时,此孔为锥形表面可以安装普通车床顶尖。主轴外表面是螺纹可以安装卡盘、花盘或类似的装置。

Tailstock.The tailstock assembly consists basically of three parts, its lower base, an intermediate part, and the quill.The lower base is a casting that can slide on the lathe bed along the guideways, and it has a clamping device to enable locking the entire tailstock at any desired location, depending upon the length of the workpiece.尾架:尾架总成基本包括三部分,底座、尾架体和套筒轴。底座是能在车床床身上沿导轨滑动的铸件,它有一定位装置能让整个尾架根据工件长度锁定在任何需要位置。The intermediate part is a casting that can be moved transversely to enable alignment of the axis of the tailstock with that of the headstock.The third part, the quill, is a hardened steel tube, which can be moved longitudinally in and out of the intermediate part as required.尾架体为一能横向运动的铸件,它可以调整尾架轴线与主轴箱轴线成一直线。第三部分,套筒轴是一淬硬钢管,它能根据需要在尾架体中纵向进出移动。

This is achieved through the use of a handwheel and a screw, around which a nut fixed to the quill is engaged.The hole in the open side of the quill is tapered to enable mounting of lathe centers or other tools like twist drills or boring bars.The quill can be locked at any point along its travel path by means of a clamping device.这通过使用手轮和螺杆来达到,与螺杆啮合的是一固接在套筒轴上的螺母。套筒轴开口端的孔是锥形的,能安装车床顶尖或诸如麻花钻和镗杆之类的工具。套筒轴通过定位装置能沿着它的移动路径被锁定在任何点。The carriage.The main function of the carriage is mounting of the cutting tools and generating longitudinal and/or cross feeds.It is actually an H-shaped block that slides on the lathe bed between the headstock and tailstock while being guided by the V-shaped guideways of the bed.大拖板:大拖板的主要功能是安装刀具和产生纵向和/或横向进给。它实际上是一由车床床身V形导轨引导的、能在车床床身主轴箱和尾架之间滑动的H形滑块。

The carriage can be moved either manually or mechanically by means of the apron and either the feed rod or the lead screw.大拖板能手动或者通过溜板箱和光杆(进给杆)或丝杆(引导螺杆)机动。

When cutting screw threads, power is provided to the gearbox of the apron by the lead screw.In all other turning operations, it is the feed rod that drives the carriage.The lead screw goes through a pair of half nuts, which are fixed to the rear of the apron.在切削螺旋时,动力通过丝杆提供给溜板箱上的齿轮箱。在其余车削作业中,都由光杆驱动大拖板。丝杆穿过一对固定在溜板箱后部的剖分螺母。

When actuating a certain lever, the half nuts are clamped together and engage with the rotating lead screw as a single nut, which is fed, together with the carriage, along the bed.When the lever is disengaged, the half nuts are released and the carriage stops.当开动特定操作杆时,剖分螺母夹在一起作为单个螺母与旋转的丝杆啮合,并带动拖板沿着床身提供进给。当操作杆脱离时,剖分螺母释放同时大拖板停止运动。

On the other hand, when the feed rod is used, it supplies power to the apron through a worm gear.The latter is keyed to the feed rod and travels with the apron along the feed rod, which has a keyway extending to cover its whole length.另一方面,当使用光杆时则通过蜗轮给溜板箱提供动力。蜗轮用键连接在光杆上,并与溜板箱一起沿光杆运动,光杆全长范围开有键槽。

A modern lathe usually has a quick-change gearbox located under the headstock and driven from the spindle through a train of gears.It is connected to both the feed rod and the lead screw and enables selecting a variety of feeds easily and rapidly by simply shifting the appropriate levers.现代车床一般在主轴箱下装备快速变换齿轮箱,通过一系列齿轮由主轴驱动。它与光杆和丝杆连接,能容易并快速地通过简单转换适当的操作杆选择各种进给。

The quick-change gearbox is employed in plain turning, facing and thread cutting operations.Since that gearbox is linked to the spindle, the distance that the apron(and the cuttingtool)travels for each revolution of the spindle can be controlled and is referred to as the feed.快速变换齿轮箱可用于普通车削、端面切削和螺旋切削作业中。由于这种齿轮箱与主轴相连,主轴每转一圈溜板箱(和切削刀具)运动的距离能被控制,这距离就可以被认为是进给。? Lathe Cutting Tools 车床切削刀具

The shape and geometry of the lathe tools depend upon the purpose for which they are employed.车床刀具的形状和几何参数取决于它们的使用目的。

Turning tools can be classified into two main groups, namely, external cutting tools and internal cutting tools.Each of these two groups include the following types of tools: 车削刀具可以分为两个主要组别,即外部切削刀具和内部切削刀具。这两组中的每一组都包括以下类型刀具: Turning tools.Turning tools can be either finishing or rough turning tools.Rough turning tools have small nose radii and are employed when deep cuts are made.车削刀具:车削刀具可以是精车刀具或粗车刀具。粗车刀具刀尖半径较小,用于深切削。

On the other hand, finishing tools have larger nose radii and are used for obtaining the final required dimensions with good surface finish by making slight depths of cut.Rough turning tools can be right-hand or left-hand types, depending upon the direction of feed.They can have straight, bent, or offset shanks.而精车刀具刀尖半径较大,用于通过微量进刀深度来获得具有较好表面光洁度的最终所需尺寸。粗车刀具按其进给方向可以是右手型的或是左手型的。它们可以有直的、弯的或偏置的刀杆。

Facing tools.Facing tools are employed in facing operations for machining plane side or end surfaces.There are tools for machining left-hand-side surfaces and tools for right-hand-side surfaces.Those side surfaces are generated through the use of the cross feed, contrary to turning operations, where the usual longitudinal feed is used.端面刀具:端面刀具用在端面作业中加工平板侧面或端部表面,也有加工左右侧表面之分。与一般采用纵向进给的车削作业相反,那些侧表面通过采用横向进给产生。

Cutoff tools.Cutoff tools, which are sometimes called parting tools, serve to separate the workpiece into parts and/or machine external annular grooves.切断刀具:切断刀具,有时也称为分割刀具,用于将工件分割成若干部分和/或加工外部环形槽。

Thread-cutting tools.Thread-cutting tools have either triangular, square, or trapezoidal cutting edges, depending upon the cross section of the desired thread.Also, the plane angles of these tools must always be identical to those of the thread forms.螺纹切削刀具:螺纹切削刀具根据所需螺纹的横截面,有三角形的、矩形的或梯形的切削刃。同时,这些刀具的平面角必须始终与螺纹形状的平面角保持一致。

Thread-cutting tools have straight shanks for external thread cutting and are of the bent-shank type when cutting internal threads.车外螺纹的螺纹切削刀具为直刀杆,而车内螺纹的螺纹切削刀具则是弯刀杆。

Form tools.Form tools have edges especially manufactured to take a certain form, which is opposite to the desired shape of the machined workpiece.成形刀具:成形刀具有专门制成特定形状的刀刃,这种刀刃形状与被加工工件所需外形正好相反。An HSS tool is usually made in the form of a single piece, contrary to cemented carbides or ceramic, which are made in the form of tips.The latter are brazed or mechanically fastened to steel shanks.

高速钢刀具通常以单件形式制造,而硬质合金或陶瓷刀具则以刀尖形式制造。后者用铜焊或机械方法固定于钢质刀杆上。

Fig.11.2 indicates an arrangement of this latter type, which includes the carbide tip, the chip breaker, the pad, the clamping screw(with a washer and a nut), and the shank.图11.2所示为机械式固定布置方式,它包括了硬质合金刀尖、断屑槽、衬垫、卡装螺杆(带有垫圈和螺母)及刀杆。

As the name suggests, the function of the chip breaker is to break long chips every now and then, thus preventing the formation of very long twisted ribbons that may cause problems during the machining operation.顾名思义,断屑槽的功能就是不时地折断长切屑,以防形成很长的可能会在机加工操作中引起问题的缠绕切屑条。

The carbide tips(or ceramic tips)can have different shapes, depending upon the machining operations for which they are to be employed.The tips can either be solid or with a central through hole, depending on whether brazing or mechanical clamping is employed for mounting the tip on the shank.硬质合金刀尖(或陶瓷刀尖)根据采用它们的机加工操作,可以有不同的形状。根据将刀尖装配在刀杆上是通过用铜焊还是机械卡装,刀尖可以是实心的或是带有中心通孔的。? Lathe Operations 车床操作

In the following section, we discuss the various machining operations that can be performed on a conventional engine lathe.在下面这节中,要讨论的是能在传统普通车床上进行的各种机加工作业。

It must be borne in mind, however, that modern computerized numerically controlled lathes have more capabilities and can do other operations, such as contouring, for example.Following are conventional lathe operations.然而,必须记住现代计算机数控车床具有更多的功能并且可以进行其它操作,例如仿型。下面是传统车床的操作。

Cylindrical turning.Cylindrical turning is the simplest and the most common of all lathe operations.A single full turn of the workpiece generates a circle whose center falls on the lathe axis;this motion is then reproduced numerous times as a result of the axial feed motion of the tool.圆柱面车削:圆柱面车削是所有车床操作中最简单也是最普通的。工件旋转一整圈产生一个圆心落在车床主轴上的圆;由于刀具的轴向进给运动这种动作重复许多次。The resulting machining marks are, therefore, a helix having a very small pitch, which is equal to the feed.Consequently, the machined surface is always cylindrical.所以,由此产生的机加工痕迹是一条具有很小节距的螺旋线,该节距等于进给。因此机加工表面始终是圆柱形的。

The axial feed is provided by the carriage or the compound rest, either manually or automatically, whereas the depth of cut is controlled by the cross slide.轴向进给通过大拖板或复式刀架手动或自动提供,然而切削深度则由横向滑板控制。In roughing cuts, it is recommended that large depths of cuts(up to 0.25in.or 6mm, depending upon the workpiece material)and smaller feeds would be used.On the other hand, very fine feeds, smaller depths of cut(less than 0.05in, or 0.4mm), and high cutting speeds are preferred for finishing cuts.粗车中,推荐使用较大切削深度(根据工件材料可达0.25英寸或6毫米)和较小进给。另一方面,精车则最好采用很小的进给、较小的切削深度(小于0.05英寸或0.4毫米)和较高的切削速度。

Facing.The result of a facing operation is a flat surface that is either the whole end surface of the workpiece or an annular intermediate surface like a shoulder.During a facing operation, feed is provided by the cross slide, whereas the depth of cut is controlled by the carriage or compound rest.端面车削:端面车削操作的结果是将工件整个端部表面或者像轴肩之类的中间环形表面加工平整。在端面车削操作中,进给由横向滑板提供,而切削深度则通过大拖板或复式刀架控制。

Facing can be carried out either from the periphery inward or from the center of the workpiece outward.It is obvious that the machining marks in both cases take the form of a spiral.端面车削既可以从外表面向内切削也可以从工件中心往外切削。很明显在这两种情况下机加工痕迹都是螺线形式。

Usually, it is preferred to clamp the carriage during a facing operation, since the cutting force tends to push the tool(and, of course, the whole carriage)away from the workpiece.In most facing operations, the workpiece is held in a chuck or on a face plate.通常在端面车削作业时习惯于采用夹住大拖板,这是因为切削力倾向于将刀具(当然包括整个大拖板)推离工件。在大多数端面车削作业中,工件被支撑在卡盘或花盘上。

Groove cutting.In cut-off and groove-cutting operations, only cross feed of the tool is employed.The cut-off and grooving tools, which were previously discussed, are employed.开槽:在切断和开槽操作中,刀具只有横向进给。要采用前面已经讨论过的切断和开槽刀具。

Boring and internal turning.Boring and internal turning are performed on the internal surfaces by a boring bar or suitable internal cutting tools.If the initial workpiece is solid, a drilling operation must be performed first.The drilling tool is held in the tailstock, and the latter is then fed against the workpiece.镗孔和内部车削:镗孔和内部车削通过镗杆或合适的内部切削刀具在内表面进行。如果初始工件是实心的,则必须首先进行钻孔作业。钻孔刀具安装在尾架上,然后对着工件进给。

Taper turning.Taper turning is achieved by driving the tool in a direction that is not parallel to the lathe axis but inclined to it with an angle that is equal to the desired angle of the taper.Following are the different methods used in taper-turning practice: 锥面车削:锥面车削通过沿着与车床主轴不平行而倾斜成一个等于锥面所需角度的方向进刀来实现。下面是在实际锥面车削中采用的不同方法:

(1)Rotating the disc of the compound rest with an angle equal to half the apex angle of the cone.Feed is manually provided by cranking the handle of the compound rest.This method is recommended for taper turning of external and internal surfaces when the taper angle is relatively large.(1)将复式刀架盘旋转一个等于圆锥体顶角一半的角度。通过摇动复式刀架操纵柄手动提供进给。当锥角相对较大时切削外锥面和内锥面推荐使用这种方法。(2)Employing special form tools for external, very short, conical surfaces.The width of the workpiece must be slightly smaller than that of the tool, and the workpiece is usually held in a chuck or clamped on a face plate.In this case, only the cross feed is used during the machining process and the carriage is clamped to the machine bed.(2)对很短的外锥面采用特殊的成型刀具。工件的宽度必须略小于刀具的宽度,并且工件通常由卡盘支撑或夹紧在花盘上。在这种情况下,机加工作业时只有横向进给而大拖板则夹紧在床身上。

(3)Offsetting the tailstock center.This method is employed for external taper turning of long workpieces that are required to have small taper angles(less than 8°).The workpiece is mounted between the two centers;then the tailstock center is shifted a distance S in the direction normal to the lathe axis.(3)偏移尾架顶尖。对需要较小锥角(小于8°)的较长工件外锥面车削采用这种方法。工件安装于两顶尖之间;然后将尾架顶尖朝垂直于车床主轴方向移动一距离S。

(4)Using the taper-turning attachment.This method is used for turning very long workpieces, when the length is larger than the whole stroke of the compound rest.The procedure followed in such cases involves complete disengagement of the cross slide from the carriage, which is then guided by the taper-turning attachment.(4)采用锥面车削附加装置。这种方法用于车削很长的工件,其长度大于复式刀架的整个行程。在这种场合下要遵循的步骤是将横向滑板完全脱离大拖板,然后通过锥面车削附加装置进行引导。

During this process, the automatic axial feed can be used as usual.This method is recommended for very long workpieces with a small cone angle, i.e., 8°through 10°.在此作业中,能照常使用自动轴向进给。对具有较小锥角(即8°到10°)的很长工件推荐采用这种方法。

Thread cutting.When performing thread cutting, the axial feed must be kept at a constant rate, which is dependent upon the rotational speed(rpm)of the workpiece.The relationship between both is determined primarily by the desired pitch of the thread to be cut.螺纹切削:在螺纹切削作业时,轴向进给必须保持恒定速率,这取决于工件的转速(rpm)。两者之间的关系基本上由被切削螺纹所需的节距决定。

As previously mentioned, the axial feed is automatically generated when cutting a thread by means of the lead screw, which drives the carriage.When the lead screw rotates a single revolution, the carriage travels a distance equal to the pitch of the lead screw.如前所述,当依靠驱动大拖板的丝杆切削螺纹时轴向进给是自动产生的。丝杆旋转一圈,大拖板就行进等于丝杆节距的一段距离。Consequently, if the rotational speed of the lead screw is equal to that of the spindle(i.e., that of the workpiece), the pitch of the resulting cut thread is exactly equal to that of the lead screw.因此如果丝杆的旋转速度等于心轴的转速(即工件的转速),生成切削螺纹的节距就正好等于丝杆的节距。

The pitch of the resulting thread being cut therefore always depends upon the ratio of the rotational speeds of the lead screw and the spindle: Pitch of the lead screw/ Desired pitch of workpiece=rpm of the workpiece/rpm of lead screw=spindle-to-carriage gearing ratio.所以被切削生成螺纹的节距总是取决于丝杆和心轴的转速比:丝杆的节距/工件所需节距=工件转速/丝杆转速=心轴到大拖板的传动比。This equation is useful in determining the kinematic linkage between the lathe spindle and the lead screw and enables proper selection of the gear train between them.这公式在决定车床心轴和丝杆之间的运动学关系时很有用,并且提供了正确挑选它们之间轮系的方法。

In thread cutting operations, the workpiece can either be held in the chuck or mounted between the two lathe centers for relatively long workpieces.The form of the tool used must exactly coincide with the profile of the thread to be cut, i.e., triangular tools must be used for triangular threads, and so on.在螺纹切削作业中,工件既能支撑于卡盘中,对相对较长的工件也能安装在两个车床顶尖之间。使用的刀具外形必须正好与要切削螺纹的轮廓一致,即三角形刀具必须用于三角形螺纹等等。

Knurling.Knurling is mainly a forming operation in which no chips are produced.It involves pressing two hardened rolls with rough filelike surfaces against the rotating workpiece to cause plastic deformation of the workpiece metal.滚花:滚花主要是一种不产生切屑的成型操作。它使用两个带有粗锉式表面的淬火滚轮压在旋转的工件上使工件金属产生塑性变形。

Knurling is carried out to produce rough, cylindrical(or conical)surfaces, which are usually used as handles.Sometimes, surfaces are knurled just for the sake of decoration;there are different types of patterns of knurls from which to choose.滚花用于生成粗糙的圆柱(或圆锥)面,通常用来作手柄。有时表面滚花只为装饰之故;有不同的滚花图案类型可供选择。? Cutting Speeds and Feed 切削速度和进给

The cutting speed, which is usually given in surface feet per minute(SFM), is the number of feet traveled in the circumferential direction by a given point on the surface(being cut)of the workpiece in 1 minute.切削速度,通常用每分钟表面英尺给出,就是一分钟内工件(被切削)表面给定点在圆周方向上行进的英尺数。

The relationship between the surface speed and rpm can be given by the following equation: SFM=πDN Where D=the diameter of the workpiece in feet N=the rpm 表面速度与转速之间的关系可以用下式给出: SFM=πDN 式中

D=用英尺表示的工件直径 N=转速

The surface cutting speed is dependant primarily upon the material being machined as well as the material of the cutting tool and can be obtained from handbooks, information provided by cutting tool manufacturers, and the like.表面切削速度主要由被切削材料和切削刀具材料决定,可以从手册、切削刀具生产商提供的资料及类似的东西上查取。Generally, the SFM is taken as 100 when machining cold-rolled or mild steel, as 50 when machining tougher metals, and as 200 when machining softer materials.For aluminum, the SFM is usually taken as 400 or above.There are also other variables that affect the optimal value of the surface cutting speed.一般而言,SFM当机加工冷轧或低碳钢时取100,机加工较坚韧的金属时取50,而机加工较软材料时取200。对铝而言,SFM通常可取400以上。也还存在其它一些变量影响表面切削速度的最佳值。

These include the tool geometry, the type of lubricant or coolant, the feed, and the depth of cut.As soon as the cutting speed is decided upon, the rotational speed(rpm)of the spindle can be obtained as follows: N=SFM/(πD)其中包括刀具形状、润滑剂或冷却液的类型、进给和切削深度。切削速度一旦确定,心轴转速(rpm)就能按下式得到: N=SFM/(πD)The selection of a suitable feed depends upon many factors, such as the required surface finish, the depth of cut, and the geometry of the tool used.Finer feeds produce better surface finish, whereas higher feeds reduce the machining time during which the tool is in direct contact with the workpiece.合适进给的选择取决于许多因素,例如所需表面光洁度、切削深度和所用刀具的几何形状。进给越小生成的光洁度越好,而在刀具与工件直接接触时进给越大则可以减少机加工时间。

Therefore, it is generally recommended to use high feeds for roughing operations and finer feeds for finishing operations.Again, recommended values for feeds, which can be taken as guidelines, are found in handbooks and in information booklets provided by cutting tool manufacturers.所以对粗车一般推荐使用较大进给,而精车则用较小进给。再者,作为指导方针的进给推荐值可以从手册和切削刀具生产商提供的资料小册子上找到。

第五篇:机械电子工程专业

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开设院校

华南理工大学、中国矿业大学、东北大学、齐齐哈尔大学 长安大学 四川三峡学院 中原工学院 重庆工商大学 西南工学院 四川理工学院 四川师范大学 贵州大学 云南大学 云南民族大学 西北大学 西安理工大学 陕西理工学院 西北师范大学 宁夏大学 新疆大学 北京工业大学(五年)北方工业大学 北京联合大学 天津工业大学 天津理工大学 河北大学 河北工业大学 河北科技大学 燕山大学 山西大学 太原理工大学 山西师范大学 内蒙古工业大学 沈阳工业大学 鞍山科技大学 辽宁工程技术大学 辽宁工业大学 辽宁师范大学 沈阳师范学院 延边大学 吉林工学院 吉林工程技术师范学院 吉林职业师范学院 黑龙江大学 哈尔滨商业大学 哈尔滨理工大学 上海理工大学 上海师范大学 上海大学 南京师范大学 江南大学 扬州大学 常州技术师范学院 淮海工学院 浙江工业大学 杭州工商大学 安徽大学 安徽理工大学 安徽师范大学 安徽建筑工业学院 合肥联合大学 福州大学 赣南师范学院 江西科技师范学院 南昌大学 山东科技大学 青岛科技大学 山东农业大学 山东大学 山东工程学院 山东师范大学 曲阜师范大学 烟台师范学院 青岛大学 郑州大学 河南科技大学 河南师范大学 信阳师范学院 湖北大学 武汉科技大学 湘潭大学 汕头大学 湛

江海洋大学 广东职业技术师范学院 深圳大学 五邑大学 广西工学院 广西大学 广西师范大学 广西民族学院 海南大学 北京电子科技学院 中央民族大学 大连民族学院 中南民族大学 西南民族大学 中国人民公安大学 中国人民武装警察部队学院 天津工程师范学院 中国农业大学 大连水产学院 中南林学院 华北电力大学 上海电力学院 河海大学 吉林大学 中国地质大学 西安工程学院 北京邮电大学 北京信息科技大学 南京邮电学院 杭州电子科技大学 桂林电子工业学院 电子科技大学 华侨大学 西南交通大学 大连海事大学 上海海事大学 武汉理工大学 中国传媒大学 成都气象学院 中国民用航空学院 北京印刷学院 西安电子科技大学 暨南大学 武汉大学 中国科学技术大学(五年)哈尔滨工程大学 江苏科技大学 大庆石油学院 石油大学 长江大学 西南石油学院 东华理工学院 中南工学院 北京理工大学 中北大学 长春理工大学 南京理工大学 重庆工业管理学院 西安工业学院 北京航空航天大学 沈阳航空工业学院 南昌航空工业学院 西北工业大学 哈尔滨工业大学 株洲工学院 清华大学 北京科技大学 北京化工大学 天津大学 大连理工大学 吉林大学 同济大学 华东理工大学 东华大学 东南大学 宿迁学院 浙江大学 合肥工业大学 厦门大学 中国海洋大学 华中科技大学 湖南大学 中南大学 重庆大学 西南师范大学 四川大学 河北建筑科技学院 中国计量学院 桂林工学院 北方工业大学 长春邮电学院 重庆邮电学院 太原科技大学 东北林业大学 辽宁石油化工大学 湖北工业大学 江南大学 东北农业大学 南京工业大学 南通大学 杭州师范学院 集美大学 沈阳理工大学 西安邮电学院 石家庄经济学院 广西工学院 天津科技大学 首都师范大学 河北农业大学 内蒙古师范大学 东北电力学院 淮阴工学院 杭州科技学院 绍兴文理学院 江西师范大学 德州学院 山东理工大学 潍坊学院 青岛理工大学 山东建筑工程学院 山东轻工业学院 河南理工大学 河南工业大学 华中师范大学 荆州师范学院 湖南科技大学 岳阳师范学院 嘉应学院 乐山师范学院 西南林学院 西安石油学院 汉中师范学院 青海师范大学 武汉工程大学 湖北民族学院等。本专业是集机械、电子、液压、气动等技术和计算机控制、检测、传感等技术于一体的新兴 综合性学科。着重培养既有扎实的机械工程基础知识、又掌握基于计算机信息处理和自 动控制理论的机电系统集成技术,造就能从事机电 系统研究、开发、应用及教学工作的 高层次人才。

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