机械项目工程专业英语施平没翻译课本学习知识补充.doc
-!4、工程机械概述 As we look around us we see a world full of “things”: machines, devices, tools; things that we have designed, built, and used; things made of wood, metals, ceramics, and plastics. We know from experience that some things are better than others; they last longer, cost less, are quieter, look better, or are easier to use. 正如我们环顾四周我们看到世界的“东西”机器全设备工具;事情我们已经设计建造和使用;木材金属陶瓷制成的东西和塑料。我们从经验知道有些事情是比别人做得更好他们去年更长成本更低更安静看起来更好或者更容易使用。理想的情况. Ideally, however, every such item has been designed according to some set of “functional requirements” as perceived by the designers that is, it has been designed so as to answer the question, “Exactly what function should it perform?” In the world of engineering, the major function frequently is to support some type of loading due to weight, inertia, pressure, etc. 但是每个这样的项目已按设计一些“功能要求”由设计者认为也就是说它的设计以回答这个问题“究竟是什么职能应是执行在工程世界”频繁的主要功能是如此的支持由于一些装载重量惯性压力式 From the beams in our homes to the wings of an airplane, there must be an appropriate melding of materials, dimensions, and fastenings to produce structures that will perform their functions reliably for a reasonable cost over a reasonable lifetime. 从我们家中的光束飞机的一个机翼等必须对产品的材料尺寸适当的融合和紧固件生产结构将执行一个较合理的成本合理的一生中其职能可靠。 In practice, engineering mechanics methods are used in two quite different ways: (1) The development of any new device requires an interactive, iterative consideration of form, size, materials, loads, durability, safety, and cost. (2) When a device fails (unexpectedly) it is often necessary to carry out a study to pinpoint the cause of failure and to identify potential corrective measures. Our best designs often evolve through a successive elimination of weak points. 在实践中工程力学方法用于在两个完全不同的方式 1.任何新设备的发展需要一个互动形式尺寸材料载荷耐久性安全性和cost. 2.迭代审议。当一个设备出现故障往往是要进行一项研究以查明故障原因并找出潜在的纠正措施。我们最优秀的设计往往演变的薄弱环节通过逐步消除。 To many engineers, both of the above processes can prove to be absolutely fascinating and enjoyable, not to mention (at times) lucrative. 对许多工程师上述过程都可以被证明是绝对精彩和愉快的更不用提有利可图。 In any “real” problem there is never sufficient good, useful information; we seldom know the actual loads and operating conditions with any precision, and the analyses are seldom exact. While our mathematics may be precise, the overall analysis is generally only approximate, and different skilled people can obtain different solutions. In the study of engineering mechanics, most of the problems will be sufficiently “idealized” to permit unique solutions, but it should be clear that the “real world” is far less idealized, and that you usually will have to perform some idealization in order to obtain a solution. 在任何“真正”的问题从来就没有足够好的有用的信息我们很少知道实际的载荷和精确操作的任何条件准确的分析很少。虽然我们可以精确的数学综合分析一般只是近似不同技能的人可以得到不同的解决方案。在工程力学研究中大多数问题都将得到充分的“理想化”允许独特的解决方案但应该清楚“现实世界”远不如理想而且你通常会在命令必须执行一些理想化获得一个解决方案。 The technical areas we will consider are frequently called “statics” and “strength of materials,” “statics” referring to the study of forces acting on stationary devices, and “strength of materials” referring to the effects of those forces on the structure (deformations, load limits, etc.). 在技术领域中我们将考虑的是通常称为“静”与“材料力学”“静”指的是对固定设备作用力学风和“材料力学”指的是这些部队在结构上的影响。 While a great many devices are not, in fact, static, the methods developed here are perfectly applicable to dynamic situations if the extra loadings associated with the dynamics are taken into account (we shall briefly mention how this is done). static 尽管许多设备都没有事实上静态的这里开发的方法是完全适用于动态的情况如果与动态相关联的额外负荷考虑。. Whenever the dynamic forces are small relative to the static loadings, the system is usually considered to be 每当动态势力相对较小的静态负荷系统通常被认为是静态的。 In engineering mechanics, we will appreciate the various types of approximations that are inherent in any real problem: Primarily, we will be discussing things which are in “equilibrium,” i.e., not accelerating. However, if we look closely enough, everything is accelerating. We will consider many structural members to be “weightless” but they never are. We will deal with forces that act at a “point” but all forces act over an area. We will consider some parts to be “rigid” but all bodies will deform under load. 在工程力学我们赞赏逼近了在任何类型的固有的各种现实问题 首先我们将要讨论的事情这是在“均衡”即没有加速。但是如果我们仔细观察的话一切都正在加速。我们会考虑很多构件是“失重”但是他们从来没有的。我们将按 照部队的这种行为在一个“点”但所有力量在一个区域的行为。我们会考虑的某些部分“刚性”但所有机构将在负荷下变形。 We will make many assumptions that clearly are false. But these assumptions should always render the problem easier, more tractable. You will discover that the goal is to make as many simplifying assumptions as possible without seriously degrading the result. 我们会作出这样的假设显然是错误的。但是这些假设应始终呈现的问题更容易更容易处理。你会发现他们的目标是使尽可能多的简化假设没有严重退化的结果。 Generally there is no clear method to determine how completely, or how precisely, to treat a problem: If our analysis is too simple, we may not get a pertinent answer; if our analysis is too detailed, we may not be able to obtain any answer. It is usually preferable to start with a relatively simple analysis and then add more detail as required to obtain a practical solution. 一般来说没有明确的方法来确定如何彻底或如何精确地说对待一个问题如果我们的分析过于简单我们可能无法获得相关的答案如果我们的分析过于详细我们可能无法获得任何答案。它通常是最好先从相对简单的分析然后添加更多的细节因为需要得到实际的解决办法。 During the past two decades, there has been a tremendous growth in the availability of computerized methods for solving problems that previously were beyond solution because the time required to solve them would have been prohibitive. At the same time the cost of computer capability and use has decreased by orders of magnitude. We are experiencing an influx of “personal computers” on campus, in the home, and in business. 在过去的二十年来一直在为解决以往无法解决的问题进行电脑化方法的途径巨大增长因为所需的时间来解决这些问题将被禁止。在同一时间内计算机能力和使用成本下降了几个数量级。我们正经历一个“个人电脑”校园涌入在家里和商业活动中。 26、车床 The general characteristics of the machine tools used in cutting operations are reviewed in this text. The equipment can be classified in different categories depending on their function and the accessories involved. The major categories are described below. 在切割操作中使用的机床的一般特征在这篇文章进行阐述。依据功能和所包含的配件设备可分为不同类别。主要类别如下所述。 Lathes Lathes are generally considered to be the oldest machine tools and were developed in the 1750s.The basic operations carried out on a lathe are turning, boring, and facing. 车床 车床通常被认为是最古老的机床并在1750s产生.车床上进行基本操作有车削镗和端面车削。 The basic components of the most common lathe( engine lathe ) are the bed, headstock, tailstock, and carriage. One end of the workpiece is clamped in a chuck that is mounted on the spindle, the spindle rotates in the headstock. The other end of the workpiece is supported by the tailstock. The headstock contains the drive gears for the spindle speeds, and through suitable gearing and the feed rod, drives the carriage and cross slide assembly. The carriage provides motion parallel to the axis of rotation, and the cross slide provides motion normal to it. A cutting tool, attached to a tool post and to the carriage, removes material by traveling along the bed. The cutting operation is performed at a certain desired peripheral speed of the workpiece, feed rate, and depth of cut 最常见的车床普通车床的基本组成部分是床身床头尾座和.托架。工件的一端是被一个安装在主轴的夹头夹紧主轴在床头旋转。工件的另一端是由尾座支撑。床头包含主轴转速传动齿轮并通过适当的齿轮和进给杆驱动车架使滑动装配滑动。托架提供运动平行旋转轴横滑板提供了正常的运动。切削刀具连接到一个刀架和托架沿床消除材料。切割操作是按工件所需的一定的外设速度进给速度切削深度运行。 A further development is the automatic lathe. The movements and controls are actuated by various mechanical means, such as cams and numerical and computer control, thus reducing labor or requiring less skilled labor. 进一步发展的是自动车床。通过各种机械手段运动和控制更加精确。如凸轮和数控和计算机控制从而减轻了工人的劳动或要求不太熟练的劳动力。 Turret lathes (developed in the 1850s)carry out multiple cutting operations, such as turning, boring, drilling, thread cutting, and facing. Various cutting tools, usually up to six are installed on a turret. The operation is quite versatile. It may be operated by hand or automatically and, once set up properly, it does not require skilled labor. There are a great variety of turret lathes available for different purposes. 转塔车床在19世纪50年代开发的能够进行了多种切割操作如车削镗钻线切割端面车削。各种切削工具通常在最多六个炮塔上安装。操作相当灵活。它可能是手工操作或自动一旦正确安装它并不需要熟练的劳动力。有种类繁多的炮塔车床可用于不同的目的 Screw machines (the first screw lathe was developed in the 1770s)are designed for high production rate machining of screws and similar parts. All the operations are performed automatically with tools attached to a special turret. The bar stock is fed automatically after each screw has been machined to a finished product. These machines may be equipped with single or multiple spindles to reduce the cycle time per piece. 螺杆机在18世纪70年代开发了第一个螺丝车床是专为高产率自动化生产螺钉 和类似部件的设计的。所有的操作都由连接到一个特殊的炮塔的工具自动执行。每个螺丝加工成成品后棒料自动送入。这些机器可能会配有单个或多个主轴 Milling Machines These are among the most versatile and useful machine tools because they are capable of performing a variety of cutting operations. There is a large selection of milling machines (developed in the 1860s)available with numerous features. The basic types are outlined below.Knee-and-column type milling machines are the most common and are used for general-purpose machining. The spindle, to which the milling cutter is attached, may be horizontal (for slab milling), or vertical (for face milling). 铣床铣床是最通用和最有用的工具机因为它们能够执行各种切割操作。有大量的提供众多特性的铣床可供选择在19世纪60年代开发的。基本类型概述如下。 升降台式铣床是最常见的用于一般用途的加工。连接铣刀的主轴可水平板坯铣削或垂直面铣。 Bed-type milling machines have the table mounted on a bed (replacing the knee) and can move only in the longitudinal direction. These machines are simple and rigidly constructed and are used for high-quantity production. The spindles may be horizontal or vertical and can be of duplex or triplex types (that is, with two or three spindles for simultaneous machining of two or three surfaces on a part). Other types of milling machines are also available, such as the planer type for heavy work and machines for special purposes 床身式铣床上安装一个平台只可以在纵向方向移动。这些机器很简单严格装配并用于高量产。主轴可水平或垂直可以双工或三工类型即有两个或三个主轴同时加工两个或三个部分表面。其他类型的铣削机也可用如用于繁重的工作的龙门式和特殊用途的机器。 Among accessories for milling machines, one of the most widely used is the universal dividing head. This is a fixture that rotates the workpiece to specified angles between individual machining steps. Typical uses are in milling parts with polygonal surfaces and in machining gear teeth. 铣床使用最广泛的配件是通用的分度头。这是一个夹具在各个加工步骤使工件旋转到指定角度。典型的用途是加工铣削有多边形表面的零件和加工齿轮齿。 Planers and Shapers These machine tools are generally used for machining large flat surfaces although other shapes, such as grooves, can also be machined. In a planer, the workpiece travels under the cross-rail equipped with cutting tools, whereas in a shaper the tool travels and the workpiece is stationary 龙门刨床和牛头刨床这些机床一般用于加工大平面 虽然其他形状如凹槽也可以加工。在龙门刨床工件上在装有刀具的下轨移动而在牛头刨床工具移动和工件是固定的。 Because of the size of the workpieces involved, planers are among the largest machine tools. Shapers may be horizontal or vertical and are also used for machining notches and keyways 由于所涉及的工件的大小龙门刨床是位于最大的机床之列。刨边机可水平或垂直也用于加工凹槽和键槽。 Broaching Machines These machines push or pull broaches, either horizontally or vertically, to generate various external or internal surfaces. They are of relatively simple construction and are actuated hydraulically and have only linear motion of the broach. Because of the great variety of shapes and parts involved, broaching machines are manufactured in a wide range of designs and sizes. 拉床 这些机器推或拉拉刀水平或垂直从而加工各种内部或外部的表面。他们的构造相对简单液压驱动可实现拉刀只有直线运动。由于涉及的形状和部分种类繁多拉床被制造成各式的设计和尺寸。 Drilling Machines These machines are used for drilling holes, tapping, counterboring, reaming, and other general-purpose boring operations. They are usually vertical, the most common one being a drill press. Drilling machines are manufactured in a wide variety of sizes, from simple bench type units to radial drills and large production machines with multiple spindles. 钻孔机这些机器用于钻孔攻丝锪孔铰孔和其他通用的镗操作。它们通常是垂直的最常见的一种是钻床。钻床制造成种类繁多的尺寸从简单的板凳类型单元到摇臂钻床和有多个主轴的大型生产设备。 46课 Computer-aided designCADinvolves the use of computers to create design drawings and product models. Computer-aided design is usually associated with interactive computer graphicsknown as a CAD system. 计算机辅助设计(CAD)涉及到电脑的使用来创建设计图纸和产品模型。计算机辅助设计通常是与交互式计算机图形学(称为CAD系统)。 Computer-aided design systems are powerful tools and are used in the mechanical design and geometric modeling of products and components 计算机辅助设计系统是强大的工具,用于产品的机械设计和几何建模和组件 In CADthe drawing board is replaced by electronic input and output devices. When using a CAD systemthe designer can conceptualize the object to be designed more easily on the Graphics screen and can consider alternative designs or modify a particular design quickly to meet the necessary design requirements or changes. 在CAD图纸被电子输入和输出设备。当使用CAD系统中,设计人员可以概念化设计的对象更容易在图形屏幕上,可以考虑替代设计或修改一个特定设计迅速满足必要的设计要求或更改。 The designer can then subject the design to a variety of engineering analyses and can identify potential problems such as an excessive load or deflection. The speed and accuracy of such analyses far surpass what is available from traditional methods. 设计师可以设计各种各样的工程分析和可以识别潜在的问题(如过度负荷或偏转)。这种分析的速度和准确度远远超过可以从传统的方法是什么。 Draft productivity rises dramatically. When something is drawn onceit never has to be drawn again. 草案生产率大幅上升。当有了一次,它从来没有再画。 it can be retrieved from a library ,and can be duplicated, stretched, sized, and changed in many ways without having to be redrawn。Cut and paste techniques are used as labor-saving aids. 它可以从库检索,可以复制,拉伸,大小,改变在许多方面不用redrawn.Cut粘贴技术用作省力艾滋病。 CAD makes possible multiview 2D drawings and the drawings can be reproduced in different levels of reduction and enlargement. CAD使可能的多视图2 d图纸,图纸可以复制在不同程度的减少和扩大。 It gives the mechanical engineer the ability to magnify even the smallest of components to ascertain if assembled components fit properly. 它让机械工程师的能力放大甚至最小的组件来确定如果组装组件配合得当。 Parts with different characteristicssuch as movable or stationary can be assigned different colors on the display. 部分具有不同特点,如移动或静止不动的,可以指定不同的颜色显示。 Designers have even more freedom with the advent of 3-D parts and manipulate them in endless variations to achieve the desired results. 设计师有更多自由随着3 d部分和操纵他们无穷无尽的变化来获得期望的结果。 Through finite element analysis stresses can be applied to be a computer model and the results graphically displayedgiving the designer quick feedback on any inherent proble
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4、工程机械概述
As we look around us we see a world full of “things”: machines, devices, tools;
things that we have designed, built, and used; things made of wood, metals, ceramics,
and plastics. We know from experience that some things are better than others; they
last longer, cost less, are quieter, look better, or are easier to use.
正如我们环顾四周我们看到世界的“东西”机器全设备工具;事情我们已经设
计建造和使用;木材金属陶瓷制成的东西和塑料。我们从经验知道有些事情是比
别人做得更好他们去年更长成本更低更安静看起来更好或者更容易使用。理想的
情况.
Ideally, however, every such item has been designed according to some set of
“functional requirements” as perceived by the designers — that is, it has been
designed so as to answer the question, “Exactly what function should it perform?”
In the world of engineering, the major function frequently is to support some type
of loading due to weight, inertia, pressure, etc.
但是每个这样的项目已按设计一些“功能要求”由设计者认为也就是说它的设
计以回答这个问题“究竟是什么职能应是执行在工程世界”频繁的主要功能是如此的
支持由于一些装载重量惯性压力式
From the beams in our homes to the wings of an airplane, there must be an
appropriate melding of materials, dimensions, and fastenings to produce structures
that will perform their functions reliably for a reasonable cost over a reasonable
lifetime.
从我们家中的光束飞机的一个机翼等必须对产品的材料尺寸适当的融合和紧固
件生产结构将执行一个较合理的成本合理的一生中其职能可靠。
In practice, engineering mechanics methods are used in two quite different ways:
(1) The development of any new device requires an interactive, iterative
consideration of form, size, materials, loads, durability, safety, and cost.
(2) When a device fails (unexpectedly) it is often necessary to carry out a study
to pinpoint the cause of failure and to identify potential corrective measures. Our
best designs often evolve through a successive elimination of weak points.
在实践中工程力学方法用于在两个完全不同的方式
1.任何新设备的发展需要一个互动形式尺寸材料载荷耐久性安全性和cost.
2.迭代审议。当一个设备出现故障往往是要进行一项研究以查明故障原因并找出
潜在的纠正措施。我们最优秀的设计往往演变的薄弱环节通过逐步消除。
To many engineers, both of the above processes can prove to be absolutely
fascinating and enjoyable, not to mention (at times) lucrative.
对许多工程师上述过程都可以被证明是绝对精彩和愉快的更不用提有利可图。
In any “real” problem there is never sufficient good, useful information; we
seldom know the actual loads and operating conditions with any precision, and the
analyses are seldom exact. While our mathematics may be precise, the overall analysis
is generally only approximate, and different skilled people can obtain different
solutions. In the study of engineering mechanics, most of the problems will be
sufficiently “idealized” to permit unique solutions, but it should be clear that
the “real world” is far less idealized, and that you usually will have to perform
some idealization in order to obtain a solution.
在任何“真正”的问题从来就没有足够好的有用的信息我们很少知道实际的载荷和
精确操作的任何条件准确的分析很少。虽然我们可以精确的数学综合分析一般只是近
似不同技能的人可以得到不同的解决方案。在工程力学研究中大多数问题都将得到充分
的“理想化”允许独特的解决方案但应该清楚“现实世界”远不如理想而且你通常会
在命令必须执行一些理想化获得一个解决方案。
The technical areas we will consider are frequently called “statics” and
“strength of materials,” “statics” referring to the study of forces acting on
stationary devices, and “strength of materials” referring to the effects of those
forces on the structure (deformations, load limits, etc.).
在技术领域中我们将考虑的是通常称为“静”与“材料力学”“静”指的是对固定设
备作用力学风和“材料力学”指的是这些部队在结构上的影响。
While a great many devices are not, in fact, static, the methods developed here
are perfectly applicable to dynamic situations if the extra loadings associated with
the dynamics are taken into account (we shall briefly mention how this is done).
static
尽管许多设备都没有事实上静态的这里开发的方法是完全适用于动态的情况如果
与动态相关联的额外负荷考虑。.
Whenever the dynamic forces are small relative to the static loadings, the system
is usually considered to be
每当动态势力相对较小的静态负荷系统通常被认为是静态的。
In engineering mechanics, we will appreciate the various types of approximations
that are inherent in any real problem:
Primarily, we will be discussing things which are in “equilibrium,” i.e., not
accelerating. However, if we look closely enough, everything is accelerating. We
will consider many structural members to be “weightless” — but they never are.
We will deal with forces that act at a “point” — but all forces act over an area.
We will consider some parts to be “rigid” — but all bodies will deform under load.
在工程力学我们赞赏逼近了在任何类型的固有的各种现实问题
首先我们将要讨论的事情这是在“均衡”即没有加速。但是如果我们仔细观察
的话一切都正在加速。我们会考虑很多构件是“失重”但是他们从来没有的。我们将按
照部队的这种行为在一个“点”但所有力量在一个区域的行为。我们会考虑的某些部分“刚
性”但所有机构将在负荷下变形。
We will make many assumptions that clearly are false. But these assumptions
should always render the problem easier, more tractable. You will discover that the
goal is to make as many simplifying assumptions as possible without seriously
degrading the result.
我们会作出这样的假设显然是错误的。但是这些假设应始终呈现的问题更容易更容
易处理。你会发现他们的目标是使尽可能多的简化假设没有严重退化的结果。
Generally there is no clear method to determine how completely, or how precisely,
to treat a problem: If our analysis is too simple, we may not get a pertinent answer;
if our analysis is too detailed, we may not be able to obtain any answer. It is usually
preferable to start with a relatively simple analysis and then add more detail as
required to obtain a practical solution.
一般来说没有明确的方法来确定如何彻底或如何精确地说对待一个问题如果我
们的分析过于简单我们可能无法获得相关的答案如果我们的分析过于详细我们可能无
法获得任何答案。它通常是最好先从相对简单的分析然后添加更多的细节因为需要得到
实际的解决办法。
During the past two decades, there has been a tremendous growth in the
availability of computerized methods for solving problems that previously were
beyond solution because the time required to solve them would have been prohibitive.
At the same time the cost of computer capability and use has decreased by orders
of magnitude. We are experiencing an influx of “personal computers” on campus,
in the home, and in business.
在过去的二十年来一直在为解决以往无法解决的问题进行电脑化方法的途径巨大增
长因为所需的时间来解决这些问题将被禁止。在同一时间内计算机能力和使用成本下降
了几个数量级。我们正经历一个“个人电脑”校园涌入在家里和商业活动中。
26、车床
The general characteristics of the machine tools used in cutting operations are reviewed in
this text. The equipment can be classified in different categories depending on their function
and the accessories involved. The major categories are described below.
在切割操作中使用的机床的一般特征在这篇文章进行阐述。依据功能和所包含的配
件设备可分为不同类别。主要类别如下所述。
Lathes Lathes are generally considered to be the oldest machine tools and were developed
in the 1750s.The basic operations carried out on a lathe are turning, boring, and facing.
车床 车床通常被认为是最古老的机床并在1750s产生.车床上进行基本操作有车削
镗和端面车削。
The basic components of the most common lathe( engine lathe ) are the bed, headstock,
tailstock, and carriage. One end of the workpiece is clamped in a chuck that is mounted on
the spindle, the spindle rotates in the headstock. The other end of the workpiece is supported
by the tailstock. The headstock contains the drive gears for the spindle speeds, and through
suitable gearing and the feed rod, drives the carriage and cross slide assembly. The carriage
provides motion parallel to the axis of rotation, and the cross slide provides motion normal
to it. A cutting tool, attached to a tool post and to the carriage, removes material by traveling
along the bed. The cutting operation is performed at a certain desired peripheral speed of
the workpiece, feed rate, and depth of cut
最常见的车床普通车床的基本组成部分是床身床头尾座和.托架。工件的一端
是被一个安装在主轴的夹头夹紧主轴在床头旋转。工件的另一端是由尾座支撑。床头包含
主轴转速传动齿轮并通过适当的齿轮和进给杆驱动车架使滑动装配滑动。托架提供运
动平行旋转轴横滑板提供了正常的运动。切削刀具连接到一个刀架和托架沿床消除材
料。切割操作是按工件所需的一定的外设速度进给速度切削深度运行。
A further development is the automatic lathe. The movements and controls
are actuated by various mechanical means, such as cams and numerical and computer
control, thus reducing labor or requiring less skilled labor.
进一步发展的是自动车床。通过各种机械手段运动和控制更加精确。如凸轮和数控
和计算机控制从而减轻了工人的劳动或要求不太熟练的劳动力。
Turret lathes (developed in the 1850s)carry out multiple cutting operations,
such as turning, boring, drilling, thread cutting, and facing. Various cutting tools,
usually up to six are installed on a turret. The operation is quite versatile. It
may be operated by hand or automatically and, once set up properly, it does not
require skilled labor. There are a great variety of turret lathes available for
different purposes.
转塔车床在19世纪50年代开发的能够进行了多种切割操作如车削镗钻
线切割端面车削。各种切削工具通常在最多六个炮塔上安装。操作相当灵活。它可能是
手工操作或自动一旦正确安装它并不需要熟练的劳动力。有种类繁多的炮塔车床可用于
不同的目的
Screw machines (the first screw lathe was developed in the 1770s)are designed for high
production rate machining of screws and similar parts. All the operations are performed
automatically with tools attached to a special turret. The bar stock is fed automatically after each
screw has been machined to a finished product. These machines may be equipped with single or
multiple spindles to reduce the cycle time per piece.
螺杆机在18世纪70年代开发了第一个螺丝车床是专为高产率自动化生产螺钉
和类似部件的设计的。所有的操作都由连接到一个特殊的炮塔的工具自动执行。每个螺丝加
工成成品后棒料自动送入。这些机器可能会配有单个或多个主轴
Milling Machines These are among the most versatile and useful machine tools because
they are capable of performing a variety of cutting operations. There is a large selection of milling
machines (developed in the 1860s)available with numerous features.
The basic types are outlined below.Knee-and-column type milling machines are the most
common and are used for general-purpose machining. The spindle, to which the milling cutter is
attached, may be horizontal (for slab milling), or vertical (for face milling).
铣床铣床是最通用和最有用的工具机因为它们能够执行各种切割操作。有大量的
提供众多特性的铣床可供选择在19世纪60年代开发的。基本类型概述如下。
升降台式铣床是最常见的用于一般用途的加工。连接铣刀的主轴可水平板坯铣
削或垂直面铣。
Bed-type milling machines have the table mounted on a bed (replacing the knee) and can
move only in the longitudinal direction. These machines are simple and rigidly constructed and
are used for high-quantity production. The spindles may be horizontal or vertical and can be of
duplex or triplex types (that is, with two or three spindles for simultaneous machining of two or
three surfaces on a part). Other types of milling machines are also available, such as the
planer type for heavy work and machines for special purposes
床身式铣床上安装一个平台只可以在纵向方向移动。这些机器很简单严格装配并
用于高量产。主轴可水平或垂直可以双工或三工类型即有两个或三个主轴同时加工两
个或三个部分表面。其他类型的铣削机也可用如用于繁重的工作的龙门式和特殊用途的
机器。
Among accessories for milling machines, one of the most widely used is the universal
dividing head. This is a fixture that rotates the workpiece to specified angles between individual
machining steps. Typical uses are in milling parts with polygonal surfaces and in machining gear
teeth.
铣床使用最广泛的配件是通用的分度头。这是一个夹具在各个加工步骤使工件旋
转到指定角度。典型的用途是加工铣削有多边形表面的零件和加工齿轮齿。
Planers and Shapers These machine tools are generally used for machining large flat
surfaces although other shapes, such as grooves, can also be machined. In a planer, the
workpiece travels under the cross-rail equipped with cutting tools, whereas in a shaper the
tool travels and the workpiece is stationary
龙门刨床和牛头刨床这些机床一般用于加工大平面 虽然其他形状如凹槽也
可以加工。在龙门刨床工件上在装有刀具的下轨移动而在牛头刨床工具移动和工件是
固定的。
Because of the size of the workpieces involved, planers are among the largest machine tools.
Shapers may be horizontal or vertical and are also used for machining notches and keyways
由于所涉及的工件的大小龙门刨床是位于最大的机床之列。刨边机可水平或垂直
也用于加工凹槽和键槽。
Broaching Machines These machines push or pull broaches, either horizontally or vertically,
to generate various external or internal surfaces. They are of relatively simple construction and are
actuated hydraulically and have only linear motion of the broach. Because of the great variety of
shapes and parts involved, broaching machines are manufactured in a wide range of designs and
sizes.
拉床 这些机器推或拉拉刀水平或垂直从而加工各种内部或外部的表面。他们的构
造相对简单液压驱动可实现拉刀只有直线运动。由于涉及的形状和部分种类繁多拉床
被制造成各式的设计和尺寸。
Drilling Machines These machines are used for drilling holes, tapping, counterboring,
reaming, and other general-purpose boring operations. They are usually vertical, the most
common one being a drill press. Drilling machines are manufactured in a wide variety of sizes,
from simple bench type units to radial drills and large production machines with multiple spindles.
钻孔机这些机器用于钻孔攻丝锪孔铰孔和其他通用的镗操作。它们通常
是垂直的最常见的一种是钻床。钻床制造成种类繁多的尺寸从简单的板凳类型单元到摇
臂钻床和有多个主轴的大型生产设备。
46课
Computer-aided designCADinvolves the use of computers to create design drawings and product
models. Computer-aided design is usually associated with interactive computer graphicsknown as a
CAD system. 计算机辅助设计(CAD)涉及到电脑的使用来创建设计图纸和产品模型。计算机辅助设计通常
是与交互式计算机图形学(称为CAD系统)。 Computer-aided design systems are powerful tools and are used in the mechanical design and geometric
modeling of products and components 计算机辅助设计系统是强大的工具,用于产品的机械设计和几何建模和组件 In CADthe drawing board is replaced by electronic input and output devices. When using a CAD systemthe designer can conceptualize the object to be designed more easily on the Graphics screen and can
consider alternative designs or modify a particular design quickly to meet the necessary design
requirements or changes. 在CAD图纸被电子输入和输出设备。当使用CAD系统中,设计人员可以概念化设计的对象
更容易在图形屏幕上,可以考虑替代设计或修改一个特定设计迅速满足必要的设计要求或更
改。 The designer can then subject the design to a variety of engineering analyses and can identify potential
problems such as an excessive load or deflection. The speed and accuracy of such analyses far
surpass what is available from traditional methods. 设计师可以设计各种各样的工程分析和可以识别潜在的问题(如过度负荷或偏转)。这种分析
的速度和准确度远远超过可以从传统的方法是什么。 Draft productivity rises dramatically. When something is drawn onceit never has to be drawn again. 草案生产率大幅上升。当有了一次,它从来没有再画。 it can be retrieved from a library ,and can be duplicated, stretched, sized, and changed in many ways
without having to be redrawn。Cut and paste techniques are used as labor-saving aids. 它可以从库检索,可以复制,拉伸,大小,改变在许多方面不用redrawn.Cut粘贴技术用作省力
艾滋病。 CAD makes possible multiview 2D drawings and the drawings can be reproduced in different levels of
reduction and enlargement. CAD使可能的多视图2 d图纸,图纸可以复制在不同程度的减少和扩大。 It gives the mechanical engineer the ability to magnify even the smallest of components to ascertain if assembled components fit properly. 它让机械工程师的能力放大甚至最小的组件来确定如果组装组件配合得当。 Parts with different characteristicssuch as movable or stationary can be assigned different colors on the display. 部分具有不同特点,如移动或静止不动的,可以指定不同的颜色显示。 Designers have even more freedom with the advent of 3-D parts and manipulate them in endless variations to achieve the desired results. 设计师有更多自由随着3 d部分和操纵他们无穷无尽的变化来获得期望的结果。 Through finite element analysis stresses can be applied to be a computer model and the results
graphically displayedgiving the designer quick feedback on any inherent proble
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