机械设计制造及其自动化专业英语翻译超级大全.docx

Unit 1 Metals
金属
The use of metals has always 在人类社会的发展中，金
been a key factor in the 属的应用起着关键性的作用。构
development of the social 成物质的大约100种基本元素中，
systems of man. Of the roughly 大约有一半为金属。金属和非金
100 basic elements of which all 属之间的区别不是特别明显。最
matter is composed, about half 基本的定义集中在元素原子间存
are classified as metals. The 在的连接形式和与这些原子相关
distinction
between a metal 联的电子的某些特性。然而，在
and a nonmetal is not always 实际应用中，可以将具有某些特
clear-cut
. The most basic 性集合金属定义为某种元素。
definition
centers around
the 除了少数例外金属在常温
type of bonding existing 下是固态的。它们是热和电的良
between the atoms of the 导体，不透光。它们往往具有较
element, and around the 高的密度。许多金属具有延展性，
characteristics
of
certain of
也就是说，在不被破坏的情况下
the electrons
associated with 它们的形状在外力的作用下可以
these atoms. In a more 发生变化。引起永久变形所需的
practical way, however, a 力和最终使金属断裂所需的力相
metal can be defined as an 当大，尽管发生断裂所需的力远

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element which has a particular 没有像所预期的撕开金属原子所
package of properties. 需的力那么大。
Metals are
crystalline
when 从我们的观点来看，在所有的
in the solid state and, with 特性中结晶性是最重要的。结晶
few exceptions (e.g. mercury), 体是这样一种结构，组成它的原
are solid at
ambient
子定位在规则的三维排列中，仿
temperatures. They are good 佛位于三维棋盘的方格的角上。
conductors of heat and 原子间距随着原子大小呈规律性
electricity and are
opaque
to 变化，原子间距是金属的一种特
light. They usually have a 性。三维排列的轴线决定了晶体
comparatively high density. 在空间中的方向。在工程实践中
Many metals are
ductile
-that 应用的金属由大量的晶体组成，
is, their shape can be changed 这些晶体称之为晶粒。在大多数
permanently by the application 情况下，晶粒在空间中是自由排
of a force without breaking. 列的。在原子范围内，晶粒之间
The forces required to cause 相互接触紧密结合。晶粒之间连
this deformation and those 接区域被称为晶界。
required to break or fracture 绝对纯净的金属从来也没有
a metal are comparatively 被生产出来过。即使绝对纯净的
high, although, the fracture 金属可以生产出来，工程师们对
forces is not nearly as high as 它们也并不会特别感兴趣，因为
would be expected from simple 它们很柔软、脆弱。实际应用中
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consideration of the forces 的金属往往都包含着一定数量的
required to tear apart the 一种或多种外来金属或非金属元
atoms of the metal. 素，这些外来元素可能是有害的
One of the more significant 也可能是有益的或者它们对某种
of these characteristics from 特定的属性没有影响。如果是有
our point of view is that of
crystallinity. A crystalline
solid is one in which the
constituent atoms are located
in a regular three-dimensional
array as if they were located
at the corners of the squares
of a three-dimensional
chessboard. The spacing of the
atoms in the array is of the
same order as the size of the
atoms, the actual spacing
being a characteristic of the
particular metal. The
directions of the axes of the
array define the orientation
of the crystal in space. The
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害的 ，这些外来元素被认为是杂
质。如果是有益的，它们被认为
是合金元素。在工程材料中往往被特意地加入一定数量的合金元
素。得到的物质被叫做合金。
金属和合金区别不大。金 属这
个词可以包括工业用纯金属和它
的合金。也许可以这样说，合金
元素越故意的被添 加，被添加的
合金元素的量越大，那么生产出
来的产品越倾向于被称之为合
金。不管怎 样，如果想使一种金
属或合金在使用中表现出稳定一
致的特性，在其中添加何种化学
成 分，它的量多大都应该在控制
范围之内。因此，当想了解决定
金属和合金性质的因素时，应充< /p>

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metals commonly used in 分考虑它们的化学组成。
engineering practice are 在50种左右的金属元素里，
composed of a large number of 工程实践中只有少数金属被大量
such crystals, called grains. 生产和使用。到目前为止最重要
In the most general case, the 的是铁，以它为基础构成了处处
crystals of the various grains 可见的钢和铸铁。（主要由铁和
are randomly oriented in 碳构成的合金）它们的重量占所
space. The grains are 有生产出来的金属重量的98%。在
everywhere in intimate contact 结构应用（也就是说，可以承受
with one another and joined 载荷的结构）中居于其次位置的
together on an atomic scale. 是铝、铜、镍和钛。在所有的金
The region at which they join 属产量中，铝占0.8％，铜占0.7
is known as a grain boundary. ％，剩下的占0.5％。剩下的金属
An absolutely pure metal 用于相对特殊的用途。例如，镍
(i.e. one composed of only one 合金主要用于抗磨损和耐高温的
type of atom) has never been 用途，由于钛合金具有高强度和
produced. Engineers would not 低密度的综合特性，钛被广泛应
be particularly interested in 用于航空工业中。镍合钛有高成
such a metal even if it were to 本和高质量的使用特性，事实上，
be produced, because it would 它们高的成本限制了它们的应
be soft and weak. The metals 用。
used commercially
inevitably
我们不能在这里讨论这些深
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contain small amounts of one or 奥的特性。在合金材料被采用和
more foreign elements, either 应用于工程实际之前，掌握其结
metallic
or nonmetallic. These 构强度和它的综合性质就够了。
foreign elements may be 举例来说，它可以强度很高，并
detrimental
, they may be 且有好的耐磨性；它可以被例如
beneficial, or they may have no
influence at all on a
particular property. If
disadvantageous, the foreign
elements tend to be known as
impurities
. If advantageous,
they tend to be known as
alloying elements
. Alloying
elements are commonly added
deliberately
in substantial
amounts in engineering
materials. The result is known
as an alloy.
The distinction between the
descriptors “metal” and
“alloy” is not clear-cut.
The term “metal” may be used
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拉伸加工，机械加工，或焊接等
特殊工艺来加工出来；它可以被
循环利用；它的成本和实用性是
首要的。

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to encompass both a
commercially pure metal and
its alloys. Perhaps it can be
said that the
an
more
deliberately alloying
addition has been made and the
larger the amount of the
addition, the more likely it is
that the product will
specifically be called an
alloy.
In any event
, the
chemical composition of a
metal or an alloy must be known
and controlled within certain
limits if
consistent

performance is to be achieved
in service. Thus chemical
composition has to be taken
into account when developing
an understanding of the
factors which determine the
properties of metals and their
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alloys.
Of the 50 or so metallic
elements, only a few are
produced and used in large
quantities in engineering
practice. The most important
by far is
iron
, on which are
based the
ubiquitous
steels
and cast irons (basically
alloys of iron and carbon).
They account for about 98% by
weight of all metals produced.
Next in importance for
structural uses (that is, for
structures that are expected
to carry loads) are
aluminum
,
copper, nickel, and titanium.
Aluminum accounts for about
0.8% by weight of all metals
produced, and copper about
0.7%, leaving only 0.5% for all
other metals. As might be
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expected, the remainders are
all used in
rather
special
applications. For example,
nickel alloys are used
principally
in corrosion-and
heat-resistant applications,
while titanium is used
extensively
in the aerospace
industry because its alloys
have good combinations of high
strength and low density. Both
nickel and titanium are used in
high-cost, high-quality
applications, and, indeed, it
is their high cost that tends
to restrict their application.
We cannot discuss these
more
esoteric
properties here.
Suffice it to say
that a whole
complex of properties in
addition to structural
strength is required of an
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alloy before it will be
accepted into, and survive in,
engineering practice. It may,
for example, have to be strong
and yet have reasonable
corrosion resistance; it may
have to be able to be
fabricated by a particular
process such as deep drawing,
machining, or welding; it may
have to be
readily
recyclable;
and its cost and availability
may be of critical importance.
Unit 2 Selection of Construction Materials
工程材料的选择
There is not a great
械性能方面都是近似的。它们的选取标准是诸
difference between “this”
如脆硬性，价格，和可用性等。不仅仅是因为
这种钢含有2％的合金元素另一种 钢含有1％
而使前者具有了后者没有的某些能力，或者是
某种钢具有神奇的名字。经过热处理后 ，任何
一种钢都具有大范围的特性；这种性质同样在
合金钢中存在。
在钢之间没有太大的区别；所有的钢在机
steel and “that” steel; all are
very similar in mechanical
properties. Selection must be
made on factors such as
and
hardenability,

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price,

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availability
, and not with the
idea that “this” steel can do
something no other can do because
it contains 2 percent instead of
1 percent of a certain alloying
element, or because it has a
mysterious
(神秘的，不可思议的)
name. A
tremendous
range of
properties is available in any
steel after heat treatment; this
is particularly true of alloy
steels.
Considerations in
fabrication(制造)
The properties of the final
part (hardness, strength, and
machinability
), rather than
properties required by forging,
govern the selection of material.
The properties required for
forging have very little relation
to the final properties of the
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关于加工的考虑
最后零件的特性（硬度、强度和可加工性）
而不是锻造特性决定了材料的选择。可锻性与
材料的最后特性联系不大；因此，提高金属的
可锻造性价值不大。高碳钢很难锻造。如果在
随 后的热处理过程进行细化，大尺寸晶粒是最
好的。

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material; therefore, not much can
be done to improve its
forgeability. Higher-carbon
steel is difficult to forge.
Large grain size is best if
subsequent heat treatment will
refine the grain size.
Low-carbon,
nickel-chromium(铬) steels are
在高温下低碳，镍铬合金钢 在受到
520-ft·lb
的冲击下表现出与相同碳含量普
通钢几乎同样的塑性。镍减 少了中碳钢的可锻
性，但对低碳钢影响不大。铬在锻造温度下时
使钢硬化，但钒没有明显的效果 ；两种加工方
法对高碳钢没有影响。
just about
as plastic at high
temperature
under a single
520-ft·lb(1 ft·lb=1.35582J)
blow
as plain steels of similar
carbon content. Nickel decreases
forgeability of medium-carbon
steels, but has little effect on
low- carbon steels. Chromium
seems to harden steel at forging
temperatures, but
vanadium
(钒)
has no discernible(可辨别的)
effect; neither has the method of
manufacture
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any effect on

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high-carbon steel.
Formability
The cold-formability of steel
is a function(功能) of its
tensile strength combined with
成形
钢的冷成形是它的拉伸强度和延展性相结
合的结 果。拉伸强度和屈服点不能太高否则在
发生弯曲时需要做很多工作；与之相类似，钢
应该有高延 展性，使其在没有断裂的情况下成
形。加工力的大小取决于屈服点，因为钢在屈
服点之上才开始 变形。与此同时，加工硬化也
ductility. The tensile strength
and yield point must not be high
or too much work will be required
in bending（弯曲）; likewise（同
样地）, the steel must have
sufficient（充足的） ductility to
flow to the required shape
without cracking. The force
required depends on the yield
point, because deformation
starts in the plastic range above
the yield point of steel.
Work-hardening also occurs here,
progressively（日益增多地）
stiffening（使变硬） the metal and
causing difficulty, particularly
（独特的，显着的） in the
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同时发生，金属变得越来越硬，增加加工难度，
尤其在低碳钢中容易发生。

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low-carbon steels.
It is quite interesting in
通过一次快速加载完成大拉伸，但以缓慢的方
this connection（关于这一点，就
此而论） to discover that deep
draws can sometimes be made in one
在这方面，相当 有趣的是你将发现有时可
式两三次加载却不能实现。如果拉伸进行了一
半就停止了，那么在再加 工之前应先退火，也
就是说工件是否有时间进行加工硬化。这不是
一种科学的叙述方法，但确实 是发生了。
rapid operation that could not
possibly be done leisurely（缓慢
地，从容不迫地） in two or three.
If a draw is half made and then
stopped, it may be necessary to
anneal（退火） before proceeding,
that is（换句话说）, if the piece
is given time to work-harden.
This may not be a scientific
statement, but it is actually
what seems to happen.
Internal stresses
Cold forming is done above the
yield point in the work-hardening
range, so internal stresses can
be built up easily. Evidence of
this is the springback（回弹） as
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内应力
在高于屈服点的加工硬化区进行冷加工很
容易产生内应力。例如工件停止成型 加工后会
发生回弹，在随后的热处理后，工件会发生翘
曲。即使是一个简单的垫圈，由于打孔和 随后
的平整加工中产生内应力，也会在热处理中呈
现严重的翘曲。

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the work leaves the forming
operation and the warpage（翘曲，
扭曲） in any（任何一种）
subsequent heat treatment. Even a
simple washer might, by virtue
of(依靠) the internal stresses
resulting from punching（冲压）
and then flattening（整平）, warp
（弯曲） severely（严格地，激烈
地） during heat treating.
（virtue n.德行, 美德, 贞操, 优
点, 功效, 效力, 英勇 believed
in the virtue of prayer.相信祈祷
的力量
When doubt exists as to（关
于） whether internal stresses
will cause warpage, a piece can be
checked by heating it to about
1100 and then letting it cool. If
there are internal stresses, the
piece is likely to（可能） deform.
Pieces that will warp severely
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当是否内应力会引起翘曲的怀疑存在时，
可以通过将工件加工至110 0然后进行冷却来
验证。如果存在内应力，工件会发生变形。经
过热处理的工件像我们看到的那 样会发生严
重的翘曲，但是我们仍然希望工件被扔到热处
理炉中被处理，这样好过它存在内应力 的状
态。

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while being heated have been
seen, yet （然而）the heat-treater
was expected to put them through
and bring them out better than
they were in the first place.
Welding
The maximum carbon content of
plain carbon steel safe for
welding without preheating or
subsequent heat treatment is
0.3%. higher-carbon steel is
welded every day, but only with
proper preheating. There are two
important factors: the amount of
heats that is put in the rate at
which it is removed.
Welding at a slower rate puts
in more heat and heats a large
volume of metal, so the cooling
rate due to loss of heat to the
base metal is decreased(减少). A
preheat will do the same thing.
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焊接
不需要预热或之后进行热处理就能安全焊
接的最高碳含量为0.3％。高碳钢通过合适的
预热通常也可焊接。有两点值得注意：吸收热
量的多少；移除速度。
低速焊接带来了更多的热量，这对金属的
大量体积进行了加热，所以冷 却速度降低。预
热可以取得与之相当的效果。例如当 被预
热至 或 时可以很好 的焊接。由于周围金
属的较高温度，当焊接弧移开焊接点后，冷却
速度不会太快，产生了低速冷 却的结果。即使
是冷作硬化速度最快的金属也可以通过预热
和慢速焊接达到良好的焊接效果。

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For example, sae4150 steel,
preheated to 600 or 800, can be
welded readily（容易地）. When the
flame or arc is taken away from
the weld, the cooling rate is not
so great, owing to the higher
temperature of the surrounding
metal and slower cooling results.
Even the most rapid air- hardening
（风硬钢） steels are weldable if
preheated and welded at a slow
rate.
Machinability
Machinability（机械加工性能）
means several things. To
production men it generally means
being able to remove metal at the
fastest rate, leave the best
possible finish, and obtain the
longest possible tool life.
Machinability applies to（应用于）
the tool-work（工具，零件）
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可加工性
可加工性意味着几件事情。对于加工者来
说，它意味着可以快速的移除金属 ，取得最好
的加工效果，得到最长的刀具寿命。可加工性
是刀具和零件的结合。

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combination.
It is not determined by
微观结构，化学成分和在冷加工下金属所呈现
hardness（硬度） alone, but by the
toughness（韧性）,
加工性不仅仅只由硬度决定，它还由韧性，
microstructure, chemical
的硬化特性所决定。在容易混淆的表示“难加
工”中，“hard”与“d ifficult”同义。许
多时候，因为材料过软而难于稳定加工。材料
柔软性和韧性能够产 生金属撕裂，使金属在完
成切削前流动至刀具前端。柔软的金属往往会
composition （成分）, and tendency
（倾向） of a metal to harden
under cold work. In the
misleading expression “too hard
to machine”, the word “hard”
is usually meant to be synonymous
（同义的） with “difficult”.
Many times a material is actually
too soft to machine readily.
Softness and toughness may cause
the metal to tear（撕裂） and flow
ahead of the cutting tool rather
than cut cleanly. Metal that are
inherently（天性地，固有地） soft
and tough are sometimes alloyed
to improve their machinability at
some sacrifice（牺牲） in
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被加入合金从而牺牲它的延展性来提高加工
性能。如黄铜中加入铅钢中加入硫磺。

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ductility. Examples are use of
lead（铅） in brass（黄铜） and of
sulfur（硫磺） in steel.
Machinability is a term used
进行诸如车、钻、铣、拉削、铰加工时的难易
to indicate the relative（比较的）
程度。
机械加工性能是在指对工件材料使用刀具
ease（不费力） with which a
material can be machined by sharp
cutting tools in operations such
as turning（车）, drilling（钻）,
milling（铣）, broaching（拉削）,
and reaming（铰）.
In the machining of metal, the
metal being cut, the cutting
tool, the coolant, the process
and type of machine tool（机床）,
and the cutting conditions all
influence the results. By
changing any one of these
factors, different results will
be obtained. The criterion（标准）
upon which the ratings（等级）
listed are based(等级评定的标准)
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在对金属进行加工时，被切削的金属，切
削刀具，冷却液，使用的机床 的种类，切削条
件均影响着切削效果。改变任何一种均会产生
不同的切削效果。切削效果评定的 准则是：车
削时在固定的切削条件下产生一定量的刀具
磨损时，被加工试件相应的材料去除量。

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is the relative volume of various
（不同种） materials that may be
removed by turning under fixed
conditions to produce an
arbitrary（任意的） fixed amount
of tool wear.
淬透性：指在规定条件下，决定钢材淬硬深度和硬度分布的特 性。即
钢淬火时得到淬硬层深度大小的能力，它表示钢接受淬火的能力。钢材淬
透性好与差，常 用淬硬层深度来表示。淬硬层深度越大，则钢的淬透性越
好。钢的淬透性是钢材本身所固有的属性，它只 取决于其本身的内部因素，
而与外部因素无关。钢的淬透性主要取决于它的化学成分，特别是含增大淬透性的合金元素及晶粒度，加热温度和保温时间等因素有关。淬透性好
的钢材，可使钢件整个截面 获得均匀一致的力学性能以及可选用钢件淬火
应力小的淬火剂，以减少变形和开裂。
淬 透性主要取决于其临界冷却速度的大小，而临界冷却速度则主
要取决于过冷奥氏体的稳定性，影响奥氏体 的稳定性主要是：
1.化学成分的影响 碳的影响是主要的，当C％小于1.2％时，随
着奥氏体中碳浓度的提高，显着降低临界冷却速度，C曲线右移，钢的淬
透性增大；当C％大于时，钢的 冷却速度反而升高，C曲线左移，淬透性
下降。其次是合金元素的影响，除钴外，绝大多数合金元素溶入 奥氏体后，
均使C曲线右移，降低临界冷却速度，从而提高钢的淬透性。
2.奥氏体晶粒大小的影响 奥氏体的实际晶粒度对钢的淬透性有
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较大的影响，粗大的奥氏体晶粒能使C曲线右移，降低了钢的临 界冷却
速度。但晶粒粗大将增大钢的变形、开裂倾向和降低韧性。
3.奥氏体均匀程度的影响 在相同冷度条件下，奥氏体成分越均匀，
珠光体的形核率就越低，转变的孕 育期增长，C曲线右移，临界冷却速度
减慢，钢的淬透性越高。
4.钢的原始组织的影响 钢的原始组织的粗细和分布对奥氏体的
成分将有重大影响。
5.部分元素，例如Mn，Si等 元素对提高淬透性能起到一定作用，但
同时也会对钢材带来其他不利的影响。
可锻性(forgeability)
金属具有热塑性，在加热状态(各种金属要求温度不同 )，可以进行压力加
工，称为具有可锻性。可锻性：指金属材料在压力加工时，能改变形状而
不 产生裂纹的性能。它包括在热态 或 冷态下能够进行锤锻，轧制，拉伸，
挤压等加工。可锻性的好坏主要与金属材料的化学成分有关
[讨论] 元素在钢中的形成物对可锻性的影响
1C 与Fe形成渗碳体Fe3C，与其它合金元素形成合金渗碳体
(FeM)3C或合金碳化物。
所有碳化物都有硬度高、塑性低、熔点高的特点，但渗碳体型碳化物
在加热到锻造温度时经适当保温可大 部分或全部溶入固溶体中，而合
金碳化物较难溶入固溶体中，对钢的可锻性影响最大。一般高合金工具钢含碳高，故具有变形抗力大，塑性差，碳化物不易被粉碎等特点。
2Mn 在钢中形成MnS以代替FeS。因MnS熔点高（1620℃），且
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呈断续分布，不像FeS熔点988℃，呈网状分布在晶界，所以可减少
热脆。
锰对 钢的过热性（粗晶）很敏感，钢锭加热温度过高，易生粗晶，使
锻造困难。锰对珠光体钢的可锻性影响较 小，奥氏体锰钢临界点将降
低。
3 Ni 炼钢时有Ni极易吸收氢形成大量气泡，锻造时 引起开裂。
Ni与Mn的作用相反，它促使硫化物成网状分布于晶界，使锻造时开
裂，所以不宜 在含硫的炉气中加热。
珠光体Ni钢在锻造时易形成片状破裂和带状组织。为了消除这种组
织 可采用镦粗和拔长交错进行，或在1000～1100℃下长时期扩散退
火。
4 Cr 铬在钢中形成较稳定的碳化物，提高碳化物在钢中的溶解
温度，减慢溶解速度。
铬能促进使铸锭生成大晶粒，冷却时沿晶界形成内裂。
高铬钢在空气中冷却即能淬火，常在表面生裂，所以不易锻造。
5 V 与碳形成稳定碳化物
V能使钢生成细晶组织，阻止过热，适当加入对锻性有利。
6 Mo 钼的熔点高，能降低钢的过热倾向它和Ni一样，使硫化物以
网状分布在晶界。
含有0.7% C，2～5%Mo的钼钢，锻造时无特殊困难。这些钢在空冷时
间淬火，要防止冷裂。Mo提高钢的热强 性，提高变形抗力。
7 W 与碳形成稳定的碳化物
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提高钢的热强性，增大变形抗力
8 Cu 铜在钢中可溶于铁素体中，也可沿晶界析出游离铜
铜中含0.15%Cu时，加热不当，表面易生裂纹，高温轧制时易产生热
脆
9 B 硼能细化晶粒，能溶解在γ和α固溶体中，与Fe化合成
Fe2B
钢中含B＞0.007%时，锻造易裂
10 S 在钢中形成硫化物或共晶体，如FeS、Fe的熔点为985℃，
且成网状布于晶界
显著降低可锻性（红脆）
11 P 促成偏析，使晶粒粗大，容易引起锻件表面龟裂
降低可锻性
Unit 3 Mechanical Properties of Materials
The material properties can be 材料特性主要分为三类：(i)
classified into three major 物理特性，(ii)化学特性，(iii)
headings: (i) Physical, (ii) 力学性能。
Chemical, (iii) Mechanical.
Physical properties
物理特性
密度或特定的重力，湿度等都
Density or specific gravity, 属于此范畴。
moisture content, etc., can be 化学特性
classified
category.
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under this 许多化学特性都归入到这个
范畴。其中包括酸性或碱性，活

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Chemical properties 性和耐腐蚀性。而在这其中最重
Many chemical properties come 要的是耐腐蚀性，通俗的解释是
under this category. These 材料在特定大气中长期使用时，
include acidity or alkalinity, 抵抗腐蚀的能力。
reactivity and corrosion. The 力学特性
most important of these is
corrosion which can be
explained in layman’s terms
as the resistance of the
material to decay while in
continuous use in a particular
atmosphere.
Mechanical properties
Mechanical properties include
the strength properties like
tensile, compression, shear,
torsion, impact, fatigue and
creep. The tensile strength of
a material is obtained by
dividing the maximum load,
which the specimen bears by the
area of cross-section of the
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力学特性包括诸如拉伸 ，压
缩，剪切，扭转，冲击，疲劳和
蠕变等强度特性。一种材料的拉
伸强度由试件承载 的最大载荷除
以试件的横截面积得到。
如图所示为在拉伸试验中沿
着X轴（横轴） 的应变和沿着Y
轴（纵轴）的应力之间的关系曲
线。材料在加载时，随着载荷大
小的变 化，尺寸会发生改变。当
卸载时，变形消失。对于许多材
料来说，上述情况发生的应力极
限值称为弹性极限。在应力- 应变
曲线中，直线关系和随后的小小
的弯曲描述了上述的加载和卸
载。
在弹性范围内，应力应变成比

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specimen. 例的应力极限值称为比例极限。
This is a curve plotted between 在这个区域中，金属服从胡克定
the stress along
and
the 律—阐述了在加载的弹性范围
the 内，应力和应变成比例关系（材
the 料在卸载后，能够完全回复它原
Y-axis(ordinate)
strain along
X-axis(abscissa) in a tensile
test. A material tends to
change or changes its
dimensions when it is loaded,
depending upon the magnitude
of the load. When the load is
removed it can be seen that the
deformation disappear s. For
many materials this occurs up
to a certain value of the
stress called the elastic
limit. This is depicted by the
straight line relationship and
a small deviation thereafter,
in the stress-strain curve.
Within the elastic range, the
limiting value of the stress up
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来的尺寸）。在曲线的实际绘制
中，比例极限值要稍微比弹性极
限值低。这可能是由于 材料回复
原尺寸需要的时间延迟。这种现
象在一些有色金属中常常出现。
铁和镍存 在明显的弹性范围，
铜，锌，锡等即使在相当低的应
力值下弹性也表现得不是很充
分。 实际上依靠测试仪器的精确
性可以使比例极限和弹性极限区
分得更清晰。
当在弹性 极限之上增大载荷
时会产生塑性变形。同时，试件
发生加工硬化。到达某点后变形
的速 度快于载荷增加的速度。这
一点叫做屈服极限点。一开始一
直在抵抗载荷的金属在这一点后

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to which the stress and strain 开始迅速地发生形变，也就是，
are proportional, is called 屈服。屈服应力叫做屈服极限。
the limit of proportionality. 试件从Q到S在到T不断地延
In this region, the metal obeys 长。在这个塑性流动期间的应力-
Hooke’s law, which states 应变关系表示为曲线上的QRST
that the stress is
proportional to strain in the
elastic range of loading (the
material completely regains
its original dimensions after
the load is removed). In the
actual plotting of the curve,
the proportionality limit is
obtained at a slightly lower
value of the load than the
elastic limit. This may be
attributed to the time-lag in
the regaining of the original
dimensions of the material.
This effect is very frequently
noticed in some no-ferrous
metals.
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段。在T点试件断裂，此时的载
荷称为断裂载荷。最大荷载值S
除以试件的横截面积为金属的最
大拉伸强度或简单地称为拉伸强
度。
逻辑上来说 ，一旦超过弹性极
限，金属应该就会屈服直至最后
断裂，在应力值上应该没有增加。
但 是实际的曲线却记录了在超过
弹性极限后的增加了的应力。这
种现象的发生可能有两种原因：
材料的应变强化；
由于塑性变形引起的试件横截面
积的缩小。
（For Christ was God, and
suffered on account of us,
being himself the Father, that

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While iron and nickel exhibit he might be able to save us.
clear ranges of elasticity, 因为基督就是上帝，为我们受苦，
copper, zinc（锌）, tin（锡）, 他自己身为父，好叫祂也能救赎
etc, are found to be 我们。）
imperfectly elastic even at 由于加工硬化，金属在发生塑
relatively（相当地） low values
of stresses. Actually the
elastic limit is
distinguishable（可区分的）
from the proportionality（比
例性） limit more clearly
depending upon the sensitivity
（灵敏性） of the measuring
instrument.
When the load is increased
beyond the elastic limit,
plastic deformation starts.
Simultaneously the specimen
gets work-hardened. A point is
reached when（这时） the
deformation starts to occur
more rapidly than the
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性变形 时会变得越来越硬。金属
拉伸越长它的直径越小。这种现
象一直持续到曲线上的S点。
超过S点后，面积减少的速度
超过了应力增加的速度。应变变
得很大，面积的减少在 某些点产
生了局部效应。叫做颈缩。
横截面积减小的速度非常快；
以至于实际上载荷降低。
伸长率和面积减少率表示了
材料的延展性。

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increasing load. This point is
called the yield point Q. the
metal which was resisting the
load till then, starts to
deform somewhat rapidly, i.
e. , yield. The yield stress is
called yield limit.
The elongation of the specimen
continues form Q to S and then
to T. the stess-strain
relation in this plastic flow
period is indicated by the
portion QRST of the curve. At
T the specimen breaks, and this
load is called the breaking
load. The value of the maximum
load S divided by the original
cross- sectional area of the
specimen is referred to as the
ultimate tensile strength of
the metal or simply the tensile
strength.
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Logically speaking, once the
elastic limit is exceeded, the
metal should starts to yield,
and finally break, without any
increase in the value of
stress. But the curve records
an increased stress even after
the elastic limit is exceeded.
Two reasons can be given for
this behavior:
the strain hardening of the
material;
the diminishing
cross- sectional area of the
specimen, suffered on account
of the plastic deformation.
The more plastic deformation
the metal undergoes, the
harder it becomes, due to
work- hardening. The more the
metal gets elongated the more
its diameter(and hence,
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cross-sectional area) is
decreased. This continues
until the point S is reached.
After S, the rate at which the
redution in area takes place,
exceeds the rate at which the
stress increases. Strain
becomes so high that the
redution in area begins to
produce a localized effect at
some point. This is called
neching.
Reduction in cross-sectional
area takes place very rapidly;
so rapidly that the load value
actully drops. This is
indicated by ST. Failure
occurs at this point T.
Then percentage elongation and
reduction in area indicate the
ductility or plasticity of the
material:
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Where and are the original and
the final length of the
specimen; and are the original
and the final cross-sectional
area.
Unit5 Design of machine and machine elements
机器和机器零件的设计
Machine design机器设计
Machine design is the art of planning or devising new or improved
machines to accomplish specific purposes. In general, a machine will
consist of a combination of several different mechanical elements
properly designed and arranged to work together, as a whole. During
the initial planning of a machine, fundamental decisions must be made
concerning loading, type of kinematic elements to be used, and
correct utilization of the properties of engineering materials.
Economic considerations are usually of prime importance when the
design of new machinery is undertaken. In general, the lowest
over-all costs are designed. Consideration should be given not only
to the cost of design, manufacture the necessary safety features and
be of pleasing external appearance. The objective is to produce a
machine which is not only sufficiently rugged to function properly
for a reasonable life, but is at the same time cheap enough to be
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economically feasible.
机器设计为了特定的目的而发明或改进机器 的一种艺术。一般来讲，机
器时有多种不同的合理设计并有序装配在一起的部件构成的，在最初的机器设计阶段，必须基本明确负载、元件的运动情况、工程材料的合理使用
性能。负责新机器的设计最 初的最重要的是经济性考虑。一般来说，选择
总成本最低的设计方案，不仅要考虑设计、制造、销售、安 装的成本。还
要考虑服务的费用，机械要保证必要的安全性能和美观的外形。制造机器
的目标不 仅要追求保证只用功能的合理寿命，还要保证足够便宜以同时保
证其经济的可行性。
The engineer in charge of the design of a machine should not only
have adequate technical training, but must be a man of sound judgment
and wide experience, qualities which are usually acquired only after
considerable time has been spent in actual professional work.
负责 设计机器的工程师，不仅要经过专业的培训，而且必须是一个准确
判断而又有丰富经验的人，具有一种有 足够时间从事专门的实际工作的素
质。
Design of machine elements机器零件的设计
The principles of design are, of course, universal. The same theory
or equations may be applied to a very small part, as in an instrument,
or, to a larger but similar part used in a piece of heavy equipment.
In no ease, however, should mathematical calculations be looked upon
as absolute and final. They are all subject to the accuracy of the
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various assumptions, which must necessarily be made in engineering
work. Sometimes only a portion of the total number of parts in a
machine are designed on the basis of analytic calculations. The form
and size of the remaining parts are designed on the basis of analytic
calculations. On the other hand, if the machine is very expensive,
or if weight is a factor, as in airplanes, design computations may
then be made for almost all the parts.
相同的 理论或方程可应用在一个一起的非常小的零件上，也可用在一个
复杂的设备的大型相似件上，既然如此， 毫无疑问，数学计算是绝对的和最
终的。他们都符合不同的设想，这必须由工程量决定。有时，一台机器 的零
件全部计算仅仅是设计的一部分。零件的结构和尺寸通常根据实际考虑。另
一方面，如果机 器和昂贵，或者质量很重要，例如飞机，那麽每一个零件都
要设计计算。
The purpose of the design calculations is, of course, to attempt
to predict the stress or deformation in the part in order that it
may sagely carry the loads, which will be imposed on it, and that
it may last for the expected life of the machine. All calculations
are, of course, dependent on the physical properties of the
construction materials as determined by laboratory tests. A rational
method of design attempts to take the results of relatively simple
and fundamental tests such as tension, compression, torsion, and
fatigue and apply them to all the complicated and involved situations
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encountered in present-day machinery.
当然， 设计计算的目的是试图预测零件的应力和变形，以保证其安全的
带动负载，这是必要的，并且其也许影响 到机器的最终寿命。当然，所有的
计算依赖于这些结构材料通过试验测定的物理性能。国际上的设计方法 试图
通过从一些相对简单的而基本的实验中得到一些结果，这些试验，例如结构
复杂的及现代机 械设计到的电压、转矩和疲劳强度。
In addition, it has been amply proved that such details as surface
condition, fillets, notches, manufacturing tolerances, and heat
treatment have a market effect on the strength and useful life of
a machine part. The design and drafting departments must specify
completely all such particulars, must specify completely all such
particulars, and thus exercise the necessary close control over the
finished product.
另外，可以充分证明，一些细节，如表面粗糙 度、圆角、开槽、制造公
差和热处理都对机械零件的强度及使用寿命有影响。设计和构建布局要完全详细地说明每一个细节，并且对最终产品进行必要的测试。
As mentioned above, machine design is a vast field of engineering
technology. As such, it begins with the conception of an idea and
follows through the various phases of design analysis, manufacturing,
marketing and consumerism. The following is a list of the major areas
of consideration in the general field of machine design:
综上所述，机械设计是一个非常宽的工程技术领域。例如，从设计理念
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到设计分析的每一个阶段，制造，市场，销售。以下是机械设计 的一般领域
应考虑的主要方面的清单：
① Initial design conception; 最初的设计理念
② Strength analysis;受力分析
③ Materials selection;材料的选择
④ Appearance; 外形
⑤ Manufacturing;制造
⑥ Safety;安全性
⑦ Environment effects;环境影响
⑧Reliability and life; 可靠性及寿命
Strength is a measure of the ability to resist, without fails,
forces which cause stresses and strains. The forces may be;
在没有破坏的情况下，强度是抵抗引起应力和应变的一种量度。这些力
可能是：
① Gradually applied;渐变力
② Suddenly applied;瞬时力
③ Applied under impact;冲击力
④ Applied with continuous direction reversals;不断变化的力
⑤ Applied at low or elevated temperatures.温差
If a critical part of a machine fails, the whole machine must be
shut down until a repair is made. Thus, when designing a new machine,
it is extremely important that critical parts be made strong enough
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to prevent failure. The designer should determine as precisely as
possible the nature, magnitude, direction and point of application
of all forces. Machine design is mot, however, an exact science and
it is, therefore, rarely possible to determine exactly all the
applied forces. In addition, different samples of a specified
material will exhibit somewhat different abilities to resist loads,
temperatures and other environment conditions. In spite of this,
design calculations based on appropriate assumptions are invaluable
in the proper design of machine.
如果一个机器的关键件损坏，整个机器必须关 闭，直到修理好为止。设
计一台新机器时，关键件具有足够的抵抗破坏的能力是非常重要的。设计者应尽可能准确地确定所有的性质、大小、方向及作用点。机器设计不是这样，
但精确的科学是这样， 因此很难准确地确定所有力。另外，一种特殊材料的
不同样本会显现出不同的性能，像抗负载、温度和其 他外部条件。尽管如此，
在机械设计中给予合理综合的设计计算是非常有用的。
Moreover, it is absolutely essential that a design engineer knows
how and why parts fail so that reliable machines which require minimum
maintenance can be designed. Sometimes, a failure can be serious,
such as when a tire blows out on an automobile traveling at high speeds.
On the other hand, a failure may be no more than a nuisance. An example
is the loosening of the radiator hose in the automobile cooling system.
The consequence of this latter failure is usually the loss of some
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radiator coolant, a condition which is readily detected and
corrected.
此外，显而易见的是一个知道零件是如何和为什麽破坏的设计师 可以设
计出需要很少维修的可靠机器。有时，一次失败是严重的，例如高速行驶
的汽车的轮胎爆 裂。另一方面，失败未必是麻烦。例如，汽车的冷却系统
的散热器皮带管松开。这种破坏的后果通常是损 失一些散热片，可以探测
并改正过来。
The type of load a part absorbs is just as significant as the
magnitude. Generally speaking, dynamic loads with direction
reversals cause greater difficulties than static loads and,
therefore, fatigue strength must be considered. Another concern is
whether the material is ductile or brittle. For example, brittle
materials are considered to be unacceptable where fatigue is
involved.
零件负载类型是一个重要的标志。一般而言，变化的动负载比静负 载会
引起更大的差异。因此，疲劳强度必须符合。另一个关心的方面是这种材
料是否直或易碎。 例如有疲劳破坏的地方不易使用易碎的材料。
In general, the design engineer must consider all possible modes
of failure, which include the following:
一般的，设计师要靠考虑所有破坏情况，其包括以下方面：
① Stress;应力
② Deformation;应变
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③ Wear;外形
④ Corrosion;腐蚀
⑤ Vibration;震动
⑥ Environmental damage;外部环境破坏
⑦ Loosening of fastening devices. 紧固件的松脱
The part sizes and shapes selected must also take into account many
dimensional factors which produce external load effects such as
geometric discontinuities, residual stresses due to forming of
desired contours, and the application of interference fit joints.
零件的尺寸和 外形的选择也有很多因素。外部负荷的影响，如几何间断，
由于轮廓而产生的残余应力和组合件干涉。
1. Unit 7 Shaper, Planer, Milling and Grinding Machines
Shapers
Shapers are machine tools used
刨床
刨床是主要用于加工平
primarily in the production of flat(平面和斜面的加工机床。此外，
坦的；扁平的) and angular(有角的） 刨床还可用于加工在其它机
surfaces. In addition, the shaper is 床上难于加工的不规则形状
used to machine irregular shapes and 和外形轮廓。内外表面和形状
contours（轮廓） which are difficult to 都可以在刨床上加工。刨床可
produce on other machine tools. Internal 以加工的形状通常有平面，斜
as well as external surfaces and shapes 面，凹槽，燕尾槽，T型槽，
can be produced on the shaper. Common 键槽，槽，锯齿和外形轮廓。
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shapes produced on the shaper are flat, 与车床上使用的刀具相类似
angular, grooves, dovetails（鸠尾榫头;的单点切削刀具在刨床上用
楔形榫头）, T-slots, keyways, slots, 来加工大多数表面。轮廓面可
serrations（锯齿状）, and contours. 以用单点的方式或成型的方
Single-point cutting tools similar to 式切削出来。用单点切削刀具
the type used on the lathe are used in
machining most surfaces on the shaper.
Contour surfaces can be produced with
either a single-point tool or a formed
cutting tool. When using a single-point
cutting tool for contour surfaces, the
depth of cut must be constantly（不断
地） regulated by the machine operator
to achieve the proper contour .
Profiling（仿形） attachments can be used
on some shapers to regulate the feed
motion and provide duplication of other
parts. Numerical control units also
enable the production of irregular
surfaces with constant regulation of the
depth of cut.
Shapers are classified by the plane
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加工曲面时，操作人员应不停
地连续调整切削深度来加工
出合适的轮廓。在一些刨床上
用仿形附件来复制其它零件
的轮廓调整进给运动。使用数
字控制单元能不断地调整切< br>削深度来完成不规则曲面的
加工。
刨床类型由发生切削的
平面来定义，或者是 卧式的或
者是立式的。另外，卧式的还
被进一步划分为推刨或拉刨。
龙门刨床 龙门刨床与刨床类似，因
为两者都用来加工平面或斜
面。不同的是龙门刨床适合加
工更大尺寸的工件。龙门刨床

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in which the cutting action occurs, 在加工过程中，工件被安装在
either horizontal or vertical. In 提供直线切削和进给运动的
addition the horizontal-type shapers 沿水平往复运动的工作台上。
are further classified as push or pull 刀具被安装在上方的交叉导
cut. A push-cut shaper cuts while the ram
（滑枕） is pushing the tool across the
work, and a pull cut machine removes
material while the tool is pulled toward
the machine. Vertical shapers use a
pushing-type cutting action and are
sometimes referred to as slotters or
keyseaters.
Planers
Planers are similar to shapers
because both machines are primarily used
to produce flat and angular surfaces.
However, planers are capable of
accommodating much larger work- pieces
than the shaper. In planer operations
the workpiece is mounted on the table
which reciprocates（往复运动） in a
horizontal plane providing a
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轨和垂直立柱上。刀具在水平
方向和垂直方 向朝向工件或
远离工件做进给运动，因此刀
具有四个直线进给运动。
因为工件尺寸和 使用刀
具类型的关系，龙门刨床的切
削速度比较慢。为了提高龙门
刨床的生产效率会使 用多个
动力头来进行切削。在上方交
叉导轨上会安装两个刀架，在
垂直导轨上会安装一 个。另一
种提高龙门刨生产率的方法
是在工作台上同时装夹多个
零件。只有工件具有相 同的切
削要求和工件尺寸较小时才
能使用这种方法。龙门刨的规
格是由机床所能加工零 件的
最大尺寸决定的。能够加工零

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straight- line cutting and feed action. 件的长、宽、高随着龙门刨型
Single-point cutting tools are mounted 号的不同而不同。
on an overhead cross rail and along the 铣床
vertically supported columns（柱状物）. 铣床可能是现代加工中除
The cutting tools are fed into or away 了车床外最为多样化的一种
from the workpiece on either the
horizontal or vertical plane, thus being
capable of four straight- line feed
motions.
Cutting speeds are slow on the planer
because of the workpiece size and type
of cutting tool being used. In order to
increase the production of the planer,
multiple tooling stations are employed.
Two tooling stations are located on the
overhead cross rails, with usually one
tooling station on the vertical
supports. Another method of increasing
production on the planer is to mount a
number of workpieces on the table at the
same time. This method is only feasible
when the workpieces require the same cut
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机床。主要设计用来加工平面
和斜面，铣床还可以 用来加工
不规则形状，曲面，槽。铣床
还可以进行钻，镗，铰和齿轮
加工。
不同种类的铣床被制造出
来以适应于不同的需求。铣床
通过其结构来定义其类型，包
括 卧式，固定工作台式，龙门
式和专用铣床。
磨床
磨床使用磨粒进行切削，
磨粒粘接在一起形成不同形
状不同尺寸的砂轮和砂带用
于切削。磨削可以带来高质量
的 工件表面。另外，工件的尺
寸精度在磨削过程中以

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and are relatively small in size. The 0.00025的精度得到提高。使
planer size is designated（指定，选定） 用不同种类的磨床可以加工
by the maximum workpiece capacity of the 工件的内外表面。相同的加工
machine. The height, width, and length 方法--使用不同形式的研磨
of the workpiece that can be 介质诸如粘接剂，粉状颗粒和
accommodated on the planer's worktable
varies with the type of planer.
Milling Machines
Milling machines are probably the
most versatile machine tools used in
modern manufacturing with the exception
of the lathe. Primarily designed to
produce flat and angular surfaces, the
milling machine is also used to machine
irregular shapes, surfaces, grooves,
and slots. The milling machine can also
be used for drilling, boring, reaming,
and gear- cutting operations.
A number of different types of
milling machines are manufactured in
order to serve the multitude of needs and
the diverse applications. Milling
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磨粒--还包括研磨，珩磨和圆
形砂轮磨削。
磨床类型由加工表面类
型来定义。通常有平面磨，外
圆磨内圆磨，和专用磨床等。

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machines are classified according to
their structure and include
column-knee, fixed bed, planer, and
special machines.
Grinding Machines
Grinding machines utilize abrasive
（研磨料） grains, bonded into various
shapes and sizes of wheels and belts to
be used as the cutting agent（介质）.
Grinding operations are used to impart
（给予，传递） a high-quality surface
finish on the workpiece. In addition,
the dimensional accuracy of the
workpiece is improved since tolerances
of 0.00001 in. [0. 00025mm] are possible
in grinding operations. Both internal
and external surfaces can be ground by
using the variety of grinding machines
available. Related operations—which
use abrasives（研磨剂）in various forms
such as paste, powder, and
grains—include lapping（研磨）, honing,
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and drum finishing.
Grinding machines are classified
according to the type of surface
produced. Common surfaces and
classifications of grinding machines
are surface, cylindrical[si'lindrik?l] ,
and special machines.
Unit 10 Hydraulic System
10单元 液压系统
The history of hydraulic power is a long one，dating from man’s prehistoric efforts to
harness the energy in the world around him．The only sources readily available were the
water and the wind—two free and moving streams.
液压动力的历史由来已久，始于人类为利用他周围的能源而作出的努力。来源只有现 成的水和风—两
种自由移动流。
The watermill，the first hydraulic motor，was an early invention· One is pictured on a
mosaic at the Great Palace in Byzantium，dating from the early fifth century·The mill had
been built by the Romans． But the first record of a watermill goes back even further, to
around 100 BC，and the origins may indeed have been much earlier·The domestication of
grain began some 5000 years before and some enterprising farmer is bound to have become
tired of pounding or grinding the grain by hand．Perhaps， in fact，the inventor was some
farmer’s wife，since she often drew the heavy jobs·
水车，第一台液压马达，是一种早期的发明。是一张画在镶嵌在大皇宫在拜占庭的图片，可 追溯到第
五世纪初，被罗马人修建的工厂。但第一次记录水车去更久远，在公元前100年左右，起源可 能更早。
驯化谷物开始大约5000年前，有进取心的农夫一定厌倦了用手磨粒加工。也许，事实上，发 明者是
一些农民的妻子，因为她经常从事沉重的工作
Manv mills staved in use until the end of the 19th century，but they had been in the
process of being replaced by the Steam engine as a source of power for the previous 150
years．The transmission of the power generated by the waterwheels was by shafting and
crude gears or pulleys．The steam engine for the first time employed an enclosed moving
stream of fluid(steam) under pressure—the principle to be later employed in hydraulic
power transmission—for transmitting power continuously from the point of generation to
the place where it was used·
许多米尔斯避免使用直到第十九世纪末 ，但他们已经在这个过程中被蒸汽发动机取代作为动力源的前
150年。电力传动产生的水车的轴系和齿 轮或滑轮。蒸汽机的第一次使用利用一个封闭的移动流液（汽）
压力，后来采用液压传动传递功率，在以 后的时代不断被使用
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The transmission of hydrostatic power to a distant point began long before that,however
．Hero of A1exandria，in the first century AD，built a device in which a fire on the temple
altar expanded air in a closed container．The air pressure forced water to travel along a tube
to the temple doors where，spilling into a container，it provided the force through ropes and
pulleys to magically open the doors
他在传输到一个遥远的水压力量点之前就开始 了,但是亚历山大在公元一世纪,建造了一个设备,其
中上底部的火增加了空气压力在一个封闭的容器， 空气压力迫使水沿着一根管子到容器口,蔓延到一
个容器,它提供的强行通过绳索和滑轮神奇地打开门
Hero also produced a steam engine of sorts． Its motion depended on the reaction forces
from jets of steam，as in the present steam turbine，but it was little understood and it was no
more than an interesting curiosity·
英雄也生 产了各种各样的蒸汽引擎。它的运动取决于反应蒸汽喷发的速度,蒸汽涡轮机至今,但很少
有人理解，它 只不过是一个有趣的好奇心?
The invention of early forms of the hydraulic pump has a similarly early origin·The first pumps were not
used to develop hydraulic power，however' but only to transfer water for irrigation or to remove it from
mines
这项发明的早期起源的形式是一个类似液压泵的东西，第一个泵已经 不只用来开发液压动力,然
而 但只有将用于矿山灌溉水
Archimedes applied the principle of the screw to hydraulic machines in the third century BC．
His screw pumps were used to raise water for irrigation or to the level of aqueducts·The piston
pump，the first mechanical device capable of generating pressure in a column of liquid，is believed to have
come from Egypt at a similarly early date．Like the screw pump，it was used only as a means for moving
water and not as a means for generating hydraulic power·
在公元 前3世纪阿基米德应用螺丝原理的液压机械在公元前3世纪。他的螺杆泵被用来提高灌溉用
水或水平沟渠 。柱塞泵是历史上第一台能够使液柱内产生压力的机械装置,它被认为来源于埃及且与
螺旋泵有同样悠久 的历史，它仅是用来作为一种移动水的手段,而不是作为一种生成液压动力的手段
In more recent years， the role of leadership in hydraulic power application has been taken over largely
by some of the larger earthmoving and construction equipment manufacturers the total Power involved is often
greater than that required in even the largest aircraft systems．the concentration of this power in a few very
large loads，as compared to the multitude of smaller loads in an airplane，has spurred the system designer to
find new，creative ways to distribute and control the power．This he has succeeded in doing to obtain
maximum precision of control and productivity while minimizing power consumption．
近年来，一些规模较大的生产土建设备的厂商在液压动力应用方面一直站着 主导地位。总功率
涉及常常会超过需要,即使在最大的系统集中的飞机，这种力量也是非常大的负载,相 比之下,许多的小
负荷,在飞机上促使系统设计者找到新的有创意的方法来分配和控制蒸发式冷凝器，他 成功地做到控
制和生产力的精度,同时最小化能耗。
in modern mobile and industrial applications，the system designer has made full use of
the wonderful flexibiIity and adaptability of hydraulics． It can readily be directed around corners and past
involving joints that virtually defy mechanical power transmission． It can be divided easily to serve
individual loads or recombined to power a high，single一load demand．
Electrical and pneumatic power distribution have similar flexibility，but lack the compactness
and certain of the other important characteristics of hydraulics．
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在现代的移 动和工业应用,系统设计者充分利用了美妙的柔性和适应性的水力学。在过去的涉及关节
它随时会被定向 转弯和,几乎可以忽略机械动力传输。它可以分为容易为各自的负载或重组来驱动一
个高单一需求。电动 、气动分布也有类似的灵活性,但缺乏的密实度和某些其他的重要特征的水力学。
A very significant feature of hydraulic power is its extreme power density． Fig．1 0．1
shows a comparison of a 400 hP(1hp=0·7457kW)hydraulic pumping source with a diesel
engine and an electrical motor of the same power capacity．The contrast is obvious and is one
that otters both an opportunity to the user of hydraulic power and a challenge to the designer
of hydraulic components.
一个非常重要的特征是它的极端水力发电功率密度。图0.1显示了一个比较的400马力(1惠普=
0?7457千瓦)液压抽油机源与柴油发动机和电动马达相同的电力产量的对比是很明显的,对用户对 液
压动力是一个机遇,对液压元件的设计师是一个挑战。
the high—power density in a hydraulic pump or motor creates design challenges beyond
those found in many other products·High loads on rapidly sliding surfaces，extreme fluid
velocities and rapidly recurring pressure applications on pumping elements(vanes，pistons。
gears) demand careful design attention to assure long life，complete reliability and efficient
operation·The user,on the other hand，reaps the benefit of a family of apparatus that is
highly responsive，finely controllable and simple to apply．When the designer understands
the user’s needs and the user understands the equipment’s full capabilities，the maximum potential of
hydraulic power can be achieved．
大功率密度液压泵或运动创造的设计的挑战,除了那些在许多其他产品的发现?高负载的迅速滑面,极< br>端的流体流速和压力应用重复元素(叶片 活塞.齿轮)需求精心设计以保证较长的使用寿命,完整的可靠
性及高效运行,另一方面是高度响应有利于家庭使用的装置,精细的可控性和简单的应用，设计师理解< br>用户的需求和用户了解设备的全部功能,其最大潜能可以达到对液压动力的实现。
Unit 12 Fluid Mechanics in Engineering
流体力学的应用
一、New words and expressions
二、Translation
Fluid Mechanics in Engineering
流体力学的应用
1、Fluid Mechanics is the branch of engineering science that is
concerned with forces and energies generated by fluids at rest and
in motion.
fluid
n.a.
流体 液体
mechanics
n.
力学，机械学
branch
n.
分支 部门
concerned 关心 关系 有关 be concerned with与…有关
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energy
n.
能源 能量 能力
rest
n.v.
休息
流体力学是工程学的一个分支，它是研究流体在静止状态与运动中的情 况下
所产生的力与能量的一门科学。
The study of fluid mechanics involves application of the
fundamental principles of mechanics and, to a lesser degree, of
thermodynamics to develop a qualitative understanding and
quantitative analysis techniques that an engineer can apply to design
or evaluation of equipment and processes that involve fluids.
involve
v.
涉及 包括 牵涉 包含 涉 牵扯 累及 卷入 带有 意味着 牵
连 波及 连累 累 意味 缠 攀 带累 笼罩
application
n.
应用 申请 应用程式 运用 申请书 用途 采用 用场 诉
状 采取 议案 意见
fundamental
a.
根本 基本的
n.
基本原理 基调
principle
n.
原则 原理 道理 信念 学说 道 意向 机宜
fundamental principles基本原理
thermodynamic 热力 热力学 热动力学
qualitative
a.
质的 性质上的 定性的qualitative analysis定性分析
quality
n.
质量 品质 素质 质 性质 品 性 成色 色
a.
最高品质的
quantitative
a.
量 定量的 quantitative analysis定量分析 quantity
n.
数量 量份量 额
technique
n.
技术 技巧 术 手法 表演法
analysis
n.
分析 分解
evaluation
n.
评价 评估 评测 evaluate
v.
评估 评价 评定 估价 鉴定
作价 评说 折价
equipment
n.
设备 装备 装置 具 武装
process
n.
过程 进程 加工 对...处置
v.
处理 提炼
流体力学研究的内容包括应用力学基本原理和少量热力学基本原理来 发
展一种定性理解和定量分析的方法，使工程师能用于设计或评估与流体有关
的设备和工艺过程 。
2、You are probably reading this book because fluid mechanics is a
required course in your curriculum.
course
n.
课程 过程 进程 历程 期间 航向 航线 航道 经过 轨道 路程
轨 程序 required course 必修课 selected course 选修课
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curriculum n.课程 课表
你也许正在读这本书，因为流体力学是你所修课程中的一门必修课。
The study of fluid mechanics is included in most engineering
curricula because the principles and methods of fluid mechanics find
many technological applications.
curricula
n.
课程
在多数工 科教学中都包含有流体力学的学习内容，因为流体力学的原理
和方法得到了很多巧妙的应用。
To illustrate a few applications, we will consider the following
fields:
① Fluid transport；
② Energy generation；
③ Environmental contro1;
④ Transportation．
illustrate
t.
（用图、实例等）说明，阐明 显示 演示 图解说明 绘图
下列领域，或多或少的都会涉及到流体力学：
① 液体传输
② 能量形成
③ 环境控制
④ 运输业
3、Fluid transport is movement of a fluid from one place to another
so that the fluid may be used or processed.
transport
n.
运输 输送 运 转运 输 航运
v.
传输 运送 搬运 搬 盘运
盘
流体运输是指将液体从某地到另外一个地方的运动过程，以便对流体进行利
用或加工。
Examples include home and city water supply systems,
cross-country oil, natural gas, and agricultural chemical pipelines,
and chemical plant piping.
include
v.
包括 包含 括 包 囊括 收录 包罗 收入 并把 赅 算
supply
v.
提供 供应 供给 供 给 补给 输送 补 输 接应 给以 资 上
补发赍
n.
输送 输
agricultural
a.
农业的 农艺的 agriculture
n.
农业 农 农 农艺
比如：家庭和市区的供水系统，跨国石油管道，天然气管道，农业化学
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品管线以及化工厂管网等。
Engineers involved in fluid transport might design systems
involving pumps, compressors, pipes, valves, and a host of other
components all directly involved with motion of fluids.
involve
v.
涉及 包括 牵涉 包含 涉 牵扯 累及 卷入 带有 意味着 牵连
波及 连累 累 意味 缠 攀 带累 笼罩
transport
n.
运输 输送 运 转运 输 航运
v.
传输 运送 搬运 搬 盘运
盘
pump
v.
抽 抽水 打气
n.
抽水机
compress
v.
压缩 压紧 压碎 compressor
n.
压缩机
valve
n.
阀 阀门 瓣膜 瓣 活门 活塞 闸门 灯
a host of许多，大量
component
n.
元件 部件 组成 构件 分枝
a.
组成的
涉及流体输送的 工程师们在系统设计时，需要包含各种与流体运动直接
相关的泵、压缩机、管道、阀门以及大量的，与流 体运动直接相关的其它部
件。
In addition to the design of new systems, engineers may evaluate
the adequacy of existing systems to meet new demands or they may
maintain or upgrade existing systems.
evaluate
v.
评估 评价 评定 估价 鉴定 作价 评说 折价 evaluation
n.
评价 评估 评测
adequacy
n.
充足 适当 足够 是否足够 是否充足 充足性 充足率
maintain
v.
保持 维持 维护 保留 维修 保养 保 持 主张 养护 认定 保
全 树立 安定 拥护maintenance n.维持，保养，维修，抚养
upgrade
n.
升级
v.
提升
除了设计新的系统之外，工程师们还需对现有系 统进行充裕性评估以满
足新的需要，或是对现有系统进行维护或升级。
4、In the field of energy generation, we find that, with the exception
of chemical batteries and direct energy-conversion devices such as
solar cells, no useful energy is
generated without fluid movement.
exception
n.
例外 反驳 不赞同 不赞成 责备
battery
n.
电池 组 炮台 炮兵连 chemical battery 化学电池
cell
n.
细胞 电池 元件 牢房 蜂房 密室 solar cell 太阳能电池
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电池之外，其它所有有效 能源的产生均离不开流体运动。
Typical energy-conversion devices such as steam turbines,
reciprocating engines, gas turbines, hydroelectric plants, and
windmills involve many complicated flow processes.
steam turbines 蒸汽轮机 蒸汽涡轮机
reciprocating engines往复式发动机
gas turbines燃气轮机
hydroelectric plant 水电站
windmill 风车
complicate 复杂
典型的能量转化装置，诸如 如蒸汽轮机、往复式发动机、燃气轮机、水
力发电厂以及风车都涉及到许多复杂的流体过程。
In all of these devices, energy is extracted from a fluid, usually
in motion.
extract vt.抽出 用力取出 使劲拔出 提取 提炼 摘录 选用
在所有这些装置中，能量均从某种流体中得到，而流体通常是运动中的。
The thermodynamic cycles of these devices usually require fluid
machinery such as pumps or compressors to do work on the fluid.
thermodynamic 热力 热力学 热动力学
cycle
n.
周期 循环 周 学时
v.
骑车 轮转
machinery
n.
机械 机器 机械装置
这些装置的热力学循环，通常需要有流体机械，如泵类、压缩机，对流
体做功。
Auxiliary equipment such as oil pumps, carburetors, fuel-injection
systems, boiler, draft fans, and cooling systems also depends on fluid
motion.
auxiliary
a.
副 辅 附属 辅助的 附加的
n.
辅助者 辅助物
carburetor n.化油器
fuel-injection systems 燃油喷射系统
boiler n.锅炉 boil
v.
烧开 熬 煮 煲 滚 沸 煮熟 烹n.沸腾 脓肿
draft fan 抽风机
辅助设备，诸如油泵、化油器、燃油喷射系统、锅炉、排风扇以及冷却
系统也 都依赖于流体的运动。
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5、Environmental control involves fluid motion.
environmental
a.
环境的 environment
n.
环境 周围
环境控制也涉及流体运动。
An estimated 75 percent of American homes are heated by forced- air
systems，in which the home air is continually recirculated to transport
heat from the combustion of fuel.
estimate
v.
估计 预计 估 估量 测度 计量 揣度 揣 臆测
n.
预算 量
force
n.
力 力量 武力 部队 动力 势力 暴力 势 强 兵 威武
v.
强行 迫
使 强迫 逼 迫 逼迫 胁迫 强加 胁 要 逼勒
continually
ad.
不断 持续 继续 连续
recirculate 循环 circulate
v.
流通 流传 发行 circul 圆弧 circu 环
流
transport
n.
运输 输送 运 转运 输 航运
v.
传输 运送 搬运 搬 盘运
盘
heat
n.
热 热力 热度 热气 燥热 暑 暑气
v.
发热 煲
combustion
n.
燃烧
fuel
n.
燃料 薪
v.
加燃料
据估计大约75%的美国家庭利用压力气 体系统来取暖，在该系统中，家庭
内的空气连续不断地进行循环以传送来自燃料燃烧的热量。
In air-conditioning systems the circulating air is cooled by a
flowing refrigerant.
circulate
v.
流通 流传 发行 circul 圆弧 circu 环流recirculate 循
环
refrigerant 制冷剂 refrigerantor 冰箱 电冰箱 冷藏室freezer 冷冻
室
在空调系统里，循环的空气被流动的致冷剂冷却。
Similar processes occur in automobile engine cooling systems, in
machine tool cooling systems, and in the cooling of electronic
components by ambient air.
ambient 环境 环境温度 周围环境
在汽车发动机冷却系统中，机床冷 却系统中和电子器件的冷却系统中都是
与此过程相类似的，电子器件的冷却是由周围的空气来完成。
6、With the exception of space travel, all transportation takes place
within a fluid medium (the atmosphere or a body of water).
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exception
n.
例外 反驳 不赞同 不赞成 责备
除了太空旅行，所有运输均发生在流体介质内（或大气中或水体里）。
The relative motion between the fluid and the transportation device
is responsible for the generation of a force that opposes the desired
motion.
流体和运输工具间的相对运动，产生了期望运动方向的反力。
This force can be minimized by the application of fluid mechanics
to vehicle design.
这种反力可以通过车辆的流体力学上的设计而降低到最小。
The fluid often contributes in a positive way, such as by floating
a ship or generating lift by air motion over airplane wings.
contribute
v.
有助于 贡献 捐助 捐献 缴纳 捐赠 投稿 捐 建树 合作
立功contribution
n.
贡献 捐助 汗马功劳 功绩 contributive
ad.
贡献
出资
float
v.
浮动 浮 漂浮 飘 漂 飘动 飘荡 泛
n.
浮筒 浮游物 彩车
generat
v.
产生generator发生器 发电机 母线
lift
n.
电梯elevator 升降机 升程
v.
抬 举起 举 提 掀起 升高 开放
拔 揭 剽窃 空运 抄袭 竖起 昂扬
wing
n.
翼 翅膀 翅 羽翼 边锋 膀 膀子
v.
空运 装以翼
ship
n.
船舰；飞船，飞艇，大型飞机（美口语）
by
prep
.(介词)就…来说（表关系）
流体也常有正面的作用，比如利用掠过机翼的空气所产生的浮力可以托起
一架飞机。
In addition, ships and airplanes derive propulsive force from
propellers or jet engines that interact with the surrounding fluid.
derive
v.
派生 导出 推导 推导出 中获得 导源
propulsive 推进 推进力
propeller
n.
螺旋桨 推进器
interact
v.
相互作用 相互影响
n.
幕间休息
surround
v.
环绕 包围 周围 围 围住 抱 拱抱 拱 困
n.
镶边
同时，船和飞机从螺旋桨或喷气式发动机获得推进力，这个推进力是螺< br>旋桨或喷气式发动机与周围流体之间的相互作用而获得的。
7、These examples are by no means exhaustive.
by no means exhaustive 不胜枚举 并非详尽无遗exhaustive
a.
详细 彻
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底的 全面的 exhaust
v.
排气 耗尽 排出 尽 竭尽 竭 用光 耗竭 穷竭 殚
澌 吃 殚竭 废语 枯窘
n.
用尽 排气 尾气
类似的例子不胜枚举。
Other engineering applications of fluid mechanics include the
design of canals and harbors as well as dams for flood control.
canal
n.
运河，沟渠，水道
harbor
n.
港湾，海港；避难所，避风港
dams
n.
水坝
flood
n.
洪水 水灾 洪 汛 滥
v.
泛滥 淹没 注满 滔 喷
流体力学在工程方面的应用还很多，比如运河、港口以及为控制洪水的堤
坝。
The design of large structures must account for the effects of wind
loading.
account
n.
帐户 帐 记事 诉说 诉 状
v.
占 认为 认定
大型建筑的设计必须考虑风载的影响。
In the relatively new fields of environmental engineering and
biomedical engineering, engineers must deal with naturally occurring
flow processes in the atmosphere and lakes, rivers, and seas or within
the human body.
environment n.环境 周围 environmental a. 环境的
biomedical 生物医学
deal with
v.
处理 处置 应付 办理 周旋 处 从事 办 待 应 经手 来往
贩 营支应
natural
a.
自然 天然 固有 当然 迹先 扑质蒙昧的
n.
白痴 天然的东西
naturally
ad.
自然 理所当然 自是
occur
v.
发生 遇 遇见 蕴蓄 来 遇合 蕴
在环境工程和生物医学等相对新兴领域，工程师们还必须应付自然存在的
流体的流动过程，包括在大气 中、湖泊中、河流中、大海中以及人体内的流
动过程。
Although it is not usually considered an engineering discipline,
the phenomena of fluid motion are central to the field of meteorology
and weather forecasting.
consider
v.
考虑 认为 研究 虑 思量 算 看成 酌量 思 深思 思虑 思忖
酌 意 动脑筋 忖 讲 熟思
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disciple
n.
弟子 门徒 徒弟 信徒 discipline
n.
纪律 学科 专业 纪 规
律 课程 风纪 学术
v.
惩戒 训练 律 惩 锻
phenomena
n.
现象
meteorology
n.
气象
weather forecasting 天气预报
尽管一般来讲，不认为气象学和天气预报是工程类学科，但是，流 体运动
现象仍是气象学和天气预报的核心。
8、Few engineers can function effectively without at least a
rudimentary knowledge of fluid mechanics.
rudimentary
a.
初步 起码 低级
很少有工程师能够一点不懂流体力学的基本知识，就能有效地发挥作用的。
Large numbers of engineers are primarily involved with processes,
devices, and systems in which a knowledge of fluid mechanics is
essential to intelligent design, evaluation, maintenance or decision
making.
primarily 主要
involve
v.
涉及 包括 牵涉 包含 涉 牵扯 累及 卷入 带有 意味着 牵连
波及 连累 累 意味 缠 攀 带累 笼罩
process
n.
过程 进程 加工 对...处置
v.
处理 提炼
essential
a.
必要 必不可少 必需 根本 要紧
n.
要点 要领
intelligent
a.
智能 聪明 聪慧 聪颖 慧 聪 懂事 心灵 机灵 合理的
evaluation
n.
评价 评估 评测 evaluate
v.
评估 评价 评定 估价 鉴定
作价 评说 折价
maintain
v.
保持 维持 维护 保留 维修 保养 保 持 主张 养护 认定 保
全 树立 安定 拥护maintenance n.维持，保养，维修，抚养
decision
a.
决断 定案 果断 主意 裁
多数工程师从事工艺、设备和系统等方面的工作， 在这些工作中，流体力
学的知识对于聪颖的设计、评估、维护与决策制定是至关重要的。
You probably cannot foresee exactly what problems you will be called
on to solve in your professional career; therefore, you would be wise
to obtain a firm grasp of the fundamentals of fluid mechanics.
foresee
v.
预知 预料 料到 预卜 未卜先知 意想 意 意料 预段
exactly
ad.
准确 究竟 恰好 刚好 恰恰 就是 恰 整 刚刚 exact
a.
确切
精确 准确 准 过份周到的 过份注意的
v.
索取 索 掊 罚金 罚款 exaction
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n.勒索 苛求 摊派
professional
a.
专业的 行
n.
专业人才
career
n.
事业 生涯 速度
wise
a.
明智 英明 高明 合理 聪 哲
firm
n.
公司 企业 厂商 果断
a.
坚定 坚决 牢固 稳固 坚固 坚 严格 硬
稳健固 牢 牢靠 决心 狠 刚 确 刚强 硬性 监 磐 严竣
v.
加固 加强 弄
结实
ad.
坚固地 坚硬地
grasp
v.
把握 掌握 了解 领会 握 把 秉 捉 持 执 意识 掺 操
fundamental
a.
根本 基本的
n.
基本原理 基调
你也许不能准确预见你的职业生涯中将会面对什么样的问题，但你牢固把
握流体力学的基础知识 肯定是应明智的。
9、These fundamentals include a knowledge of the nature of fluids and
the properties used to describe them, the physical laws that govern
fluid behavior, the ways in which these laws may be cast into
mathematical form, and the various methodologies (both analytical and
experimental) that may be used to solve engineering problems.
fundamental
a.
根本 基本的
n.
基本原理 基调
natural
a.
自然 天然 固有 当然 迹先 扑质蒙昧的
n.
白痴 天然的东西
naturally
ad.
自然 理所当然 自是
cast
v.
投 投射 抛 撒 下 撇 付
n.
铸件 抛掷 辗转
methodology
n.
方法论
这些基础包括对下列问题的了解：流 体的种类，以及用来描述流体的那些
属性、支配流体行为的物理学定律、由这些物理学定律生成的数学模 型方法
和那些用来解决实际问题的方法（既包括分析的方法，也包括实验的方法）。
Unit15 control system fundamentals
(1)Numerically controlled machines often weigh up to 100 tons and
yet are required to position a cutting tool with an accuracy of the
order of 0.002mm. The control system must move the tool at federates
as high as 8cmsec while encountering loads which may vary
dramatically on a given path. The NC machine must have dynamic response
characteristics that enable it to follow intricate contours with a
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minimum of path error. Clearly, these requirements dictate a
control system that is matched to the mechanical characteristics of
the machine it drives.
数控机械通常重达100吨，可是却要求安装一个精度高达0.002mm数量
级的切削刀具。在遇到预定路径下载荷变化较大的情况时，控制系统仍要以
高达8厘米秒的进给速度下 移动刀具。数控机床必须具有动态响应特性，
使它能够复制较复杂的轮廓线，并具有最小的路径误差。显 然，这些条件要
求控制系统必须与它所驱动的机器机械特征相匹配。
(2) A control system is a combination of devices that regulate
an operation by administering the flow of energy and other resources
to and from that operation . Essentially, a control system is made
up of interrelated subsystems that perform tasks which in orthodox
machining processes are managed by an intelligent human operator.
控制系统是一组设备的组合，他通过管理能量流和与该操作有关的其它
资 源来控制操作。从本质上说，控制系统由相互关联的子系统组成，并有它
们执行传统上通常由只能人工操 作员控制的机械加工过程。
(3) The control systems for NC machines therefore serve to replace
the human machine operator and significantly improve upon even the
best human performance. A direct analogy can be made between numerical
controls and the human operators the replace. Both:
因此， 数控机床的控制系统用于代替人工机器操作员并可显著地改进即
使最好的人工操作。可从以下几个方面对 数字控制系统和它们代替的人工操
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作员直接进行类比：
① Sense the current status of the machine;
② Make logical decisions which are required to accomplish a task;
③ Communicate decisions to the machine by actuating proper
mechanical devices;
④ Have the ability to store information: instructions, data, and
the results of logical decisions.
① 检测机器的现状；
② 做出完成任务所需的逻辑决策；
③ 通过操纵机械设备向机器传送决策信息；
④ 具有储存指令、数据、与逻辑决策结果等各种信息的能力。
(4) In summary, a machine control system is a combination of
electronic circuitry, sensing devices, and mechanical components
which guide the cutting tool along a predefined path.
总之，机械控制系统是电路系统、检 测装置以及机器零件的结合体，并
指导切削刀具沿着预定路径实现进给动作。
(5) In the sections that follow, the reader is introduced to the
theory of machine control.
以下的内容，将给读者介绍机械控制的原理。
(6) We have attributed four major characteristics to any control
system: the ability to sense data; make logical decisions; communicate
and actuate; and store information in a memory. If a system performs
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these functions without the aid of a human operator, by definition
it automatically controls a given task. Let us consider one such simple
operation.
译文：我们已经总结了所有控制系统具有的四个主要特 征：监测数据的能
力；做出逻辑决策；通讯及操纵机械；及在内存中存储信息。如果系统在不
借 助人工帮助下执行这些操作，根据定义它是自动地控制给定任务。让我们
考虑下面这个简单的操作。
(7) Suppose that an electric motor is used to a freight conveyor
between two floors of a building. To operate smoothly the conveyor
must maintain a constant speed as additional loads are added from
loading shoots. We can assume that the speed of rotation of an electric
motor is directly proportional to the electric current supplied to
it. Hence as the load increases on the conveyor, the torque requirement
of the motor is increased and additional power must be supplied to
maintain constant speed. This is usually achieved by increasing the
supply voltage.
译文：假设电子马达被用于某建筑物两层楼的货物传送，为 了顺利操作，
当额外的载荷被加上时，传送带必须维持恒定的速度。我们可以假设，电动
机马达 的转速和直接所供给的电流成正比。因此，当传送带上的载荷增加时，
马达的扭矩要求增加，因此为了维 持恒定的速度必须提供附加的动力，这通
常通过增加供给电压来实现。
（8）If a motor speed indicator is within sight of a human operator,
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he can control the conveyor speed by increasing or decreasing the
voltage supply manually. S
如果一个电机的速度指示器在人类操作者的视线范围内，他可以通过手动
增加或减小电源电压来控制传送 带速度。该系统如图15.1所示。
（9）As indicated by Fig.15.1 (a), the operator first senses that
the speed is below the desired value. Logically, he determines at an
increase in power will increase motor speed. He communicates a
decision, by actuating the power supply control lever, to increase
voltage until the desired speed reading is obtained. In Fig.15.1 (b)
the desired speed is read; hence, the operator takes no action. If
the load is decreased so that a speed greater than the desired value
is registered in Fig.15.1 (c), the operator will decrease voltage.
上述过程如示意图15.2所示。图中所示的系统并不会 自动化的。然而。
如果操作员模块用一个设备替换，并执行所显示的功能，自动控制系统将会
实 现。
自动控制系统有时被称作伺服机械。伺服机械或者是机电元件的复杂组
合，或者就是一个 简单的机械装置。不管伺服机械是否复杂，它总是具有如
图15.2所示的那些特性。
(12) Consider a simple mechanical device that performs the
automatic control function for our conveyor system(Fig,15.3).Such a
device , called a Watt speed governor , can automatically control the
speed of an electric motor.
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考虑执行我们的输送机系统的一个简单的机械设备(Fig. 15.3)。这样的
设备，称为瓦特调速器，可以自动地控制一台电动机的速度
(13) As shown in Fig.15.3, the Watt speed governor consists of
two weighted arms connected to a shaft, S2, and a sleeve. The motor
shaft, S1, is coupled to the governor shaft, S2, so that the rotational
velocity of S2 is proportional to S1. As motor speed increases ,
centrifugal force moves the weights ,W, outward , causing the weighted
arms to rotate through some angle,
θ
.The weights, angle, and sleeve
position are chosen so that the proper speed will cause the voltage
supply lever to be positioned at a neutral position. Variations in
speed will cause the appropriate movement of the sleeve and lever.
如fig.15.3所示，瓦特调速器由两个 加权臂连接到轴，s2中和套筒。
耦合到的电动机轴中，s1，s2的旋转速度，从而使调速器轴，s2 的比例给
s1。在马达速度增加时，离心力的权重，瓦特，向外移动，通过，导致加权
臂旋转一 定的角度，重量，角度，和套筒位置的选择，以便恰当的速度将会
导致电压供应拉杆将定位在中立的位置 。速度的变化将导致的套筒和杠杆适
当运动

Unit 17 Feedback and Its Effect
1 The concept of feedback plays an important role in control system.
Feedback is a major requirement of a closed-loop control system.
Without feedback, a control system would not be able to achieve the
accuracy and reliability that are practical required in most
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applications. In reality, the reasons for using feedback carry far
more meaning than the simple one of comparing the input with the output
in order to reduce the error. The reduction of system error is merely
one of the many effect that feedback may bring upon a system. We shall
now show that feedback also has effects on such system performance
characteristics as stability, bandwidth, overall gain, impedance, and
sensitivity.
反馈的概念在控制系统中扮演了一个重要的角色。在一个闭环控制系统
中反馈是一个主要条件，没有反馈 ，一个控制系统将不能实现在实际应用中
所需要的准确性和可靠性。现实中，使用反馈承载着更重大的意 义与减小输
入、输出误差相比。减小系统错误，仅仅是反馈带给系统的影响之一。我们
现在举几 个反馈也能影响系统的性能特征：稳定性、频宽、总增益、阻抗和
灵敏度。
2 To understand the effects of feedback on a control system, it is
essential that we examine this phenomenon with a broad mind. When
feedback is deliberately introduced for the purpose of control, its
existence is easily identified. However, there are numerous
situations wherein a physical system that we normally recognize as
an inherently non- feedback system may turn out to have feedback when
it is observed in a certain manner. In general we can state that
whenever a closed sequence of cause-and-effect relation exists among
the variables of a system, feedback is said to exist. This viewpoint
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will inevitably admit feedback in a large number of systems that
ordinarily would be identified as non-feedback systems.
为了理解反馈对控制系 统的影响，从广义上说我们分析这个现象也是必
要的。当反馈被有意的引入作为控制的目的，它的存在是 不容易确定的。然
而，在许多情况下，在一个物理系统中，我们通常认为一个本质上没有反馈
的 系统也许原来是有反馈的，当它被观察在一个特殊的方式下。通常，我们
可以指出，只要系统的变量之间 存在闭合序列的因果关系，就认为反馈存在。
这个观点将不可避免地承认，许多反馈系统通常被认为是无 反馈的系统。
3 We shall now investigate the effects of feedback on the various
aspects of system t the necessary background and
mathematical foundation of linear system theory,at this point we can
only rely on simple static system notation for our discussion. Let
us consider the simple feedback system configuration shown in
Fig.17.1,where r is the input signal,c the output signal, e the
error ,and b the feedback signal. The parameters G and H may be
considered as constant gains. By simple algebraic manipulations it
is simple to show that the input-output relation of the system is
M=cr=G(1+GH) （17.1）
Using this basic relationship of the feedback system structure, we
can uncover some of the significant effects of feedback.
我们现在调查 反馈在不同方面对系统的影响。没有必要的背景和线性系
统理论的数学基础，在这一点上，我们只能依靠 简单的静态系统表示我们的
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讨论。让我 们考虑简单的反馈系统结构如公式17.1所示，其中r是输入信号，
C的输出信号，e是误差，b是反 馈信号。参数G和H可以被认为是恒定的
增益。通过简单的代数运算，它是简单的显示系统的输入 - 输出关系是M =
C R= G（1+ GH）（17.1）。使用这个反馈系统结构的基本关系，我们可
以揭示一些显着效果反馈。
Effect of feedback on overall again
4 As seen from Eq. (17.1) , feedback affects the gain G of a
non-feedback system by a factor of 1+ GH. The reference of the feedback
in the system of Fig. 17.1 is negative, since a minus sign is assigned
to the feedback signal. The quantity GH may itself include a minus
sign, so the general effect of the feedback that it may increase or
decrease again. In a practical control system, G and H are functions
of frequency, so the magnitude of 1+GH may be greater than 1 in one
frequency range but less than 1 in another. Therefore, feedback could
increase the gain of system in one frequency range but decrease it
in another.
反馈队总增益的影响
由式（17.1）可知，反馈对无反馈系统增益G的影响是除以因式1 +GH。
在图17.1 系统的参考反馈是负的，因此，给反馈信号加一个负号。GH量本
身也可能包含一个负号，所以反馈的总 效应可以使增加增益，也可以是减小
增益。在一个实际控制系统中，G和H是频率的函数，所以1 + GH的大小
在某一频率变化中可能大于1，但在另一频率中小于1。因此，反馈可以在
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某一频率范围变化中增加系统增益，但在另一频率中减小增益。
Effect of Feedback on Stability
5 Stability is a notion that describes whether the system will be
able to follow the input command. In a nonrigorous manner, a system
is said to be unstable if its output is out of control or increase
without bound.
反馈在稳定性方面的影响
稳定性是描述系统是否会跟随输入指令而动作的概念。在不严格的 情况
下，一个系统的输出失控或者是对外增加无界限就说明失去了稳定性.
6 To investigate the effect of feedback on stability, we can gain
refer to the expression in Eq. (17.1). If GH=-1, the output of the
system is infinite for any infinite input. Therefore, we may state
that feedback can cause a system that is originally stable to become
unstable. Certainly, feedback is a two-edged sword; when it is
improperly used, it can be harmful. It should be pointed out, however,
that we are only dealing with the static case here, and, in general
GH=-1 is not the only condition for instability.
探讨反馈对稳定性的影响，我们可以参考公式中的表达（17.1）。如果
GH = 1，该系 统的输出是无限的任何无限输入。因此，我们可能会导致系统
状态反馈，原本是稳定不稳定。当然，反馈 一二双刃剑；用得不好，它可以
是有害的。应当指出，然而，我们只在这里处理，静态情况下，在一般的
GH = - 1是不是唯一的条件不稳定。
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Effect of Feedback on Sensitivity（反馈在灵敏度方面的影响）
7 Sensitivity considerations often play an important role in the
design of control systems. Since all physical elements have properties
that change with environment and age, we cannot always consider the
parameters of a control system to be completely stationary over the
entire operating life of the system. For instance, the winding
resistance of an electric motor changes as the temperature of the motor
rises during operation. In general, a good control system should be
very insensitive to these parameter variations while still able to
follow the command responsively.
灵敏度的考虑往往在 控制系统的设计中发挥着重要的作用。由于所有物
理元素的属性都会随着环境和时间而改变，所以我们不 能总是认为控制系统
的参数在整个系统的工作寿命中是完全固定的。例如，在操作过程中电动机
绕组随着马达温度的上升而改变。通常，一个良好的控制系统对这些参数的
变化应该是非常不敏感的，然 而仍旧能够按照命令响应。
8 In general, the sensitivity of the system gain of a feedback system
to parameter variations depends on where the parameter is located.
The reader may derive the sensitivity of the system in Fig.17.1 due
to the variation of H.
通常，反馈系 统的增益对参数的变化的灵敏度取决于参数所在的位置。
读者会在图17.1中根据H值的变化而取得灵 敏度的变化。
Effect of Feedback on External Disturbance or Noise

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9 All physical control systems are subject to some types of
extraneous signals or noise during operation . Examples of these
signals are thermal noise voltage in electronic amplifiers and brush
or commutator noise in electric motors .
外部干扰或噪声影响的反馈
在操作期间，所有物理控制系统受到了某些类型的外部信号或噪声 。这
些信号的例子是热噪声电压的电子放大器和画笔或换向器噪声的电动马达。
10 The effect of feedback on noise depends greatly on where the noise
is introduced into the system no general conclusions can be made.
However , in many situations , feedback can reduce the effect of noise
on system performance .
对噪声的反馈影响极大地取决于地方噪音引入到系统 ；可没有一般性
的结论。然而，在许多情况下，反馈可以减少对系统性能的噪音影响。
11 In general , feedback also has effects on such performance
characteristics as bandwidth , impedance , transient response , and
frequency response .
一般情况下，反馈也有对这种性能特点作为带宽、 阻抗、 瞬态响应和
频率响应的影响。
UNIT 20
the role of measurement is to provide information on
system status which,in a
mechatronic system, is used to control the operation
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of the system. this function is performed by the measure
ment modules which incorporate the necessary sensors and
transducers together with any local signal processing.
在机电一体化系统中，测量 的角色是提供用于控制系统运行的系统状态信息。
这个功能是通过必要的传感器和转换器结合局部信号处 理而形成的测量组
件来完成的。
measurement technology is not a new science but can
be traced back to origins in trade,where the need to qu
antify,on a basis which was both repeatable and represent
ative,the nature of goods on offer led to the introducti
on of standards for measures such as volume and weight.
with the growth in science and technology as exemplifie
d by the renaissance, more and specific measuring instrum
ents evolved to support the growing interest in and inve
stigation of the physical world. 测量技术不是一门新 的光科学，
他可以追溯到交易的起源，在可重复性和典型性基础上，由于量化的需要，
出售商品 的自然特性导致了像体积、重量等测量标准的引入。随着以文艺复
兴时期为代表的科技发展，越来越多的 专门的测量工具逐步发展以支持我们
队物理世界日益增加的关注和研究。
with the advent of the industrial revolution, instrume
ntation and measurement science began to be applied to m
anufacturing. the early instruments were analogue in natur
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e and provided information about the basic physical param
eters concerned with the operation of the process. 随着
工业革命的出现，工 具盒测量科学开始应用与制造业。早期的工具是仿自然
的，只提供与加工过程有关的物理参数的信息。< br>feedback was achieved by the operator who read the instr
uments and then made the necessary adjustments to maintai
n the process within the required bounds. 反馈是通过操作人
员读取仪器上的读数，然后做必要的调整，以把 工艺过程维持在所要求的范
围之内来达到的。
the next step forward came with the introduction of
the steam engine and automatic feedback control mechan
isms such as the watt governor for speed control. follow
ing this lead, instrumentation gradually became more integ
rated with the process, providing feedback information to
a controller which then regulated the system behavior w
ith minimum of manual intervention. 向前推进的下一阶段是伴随
蒸汽机以及瓦特调速器等自动反馈机械装置的引入到来的。随之而来，仪器< br>产业与过程结合越来越紧密，它提供反馈信息给控制器而使系统操作依赖较
少的人工干预。
by the late 1960s the advantages of discrete control
had been recognized and production processes were often
controlled by relay based relay controllers,
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though complex in configuration and layout, were relativ
ely unsophisticated and incapable of handling complex in
formation. 到1960年代末，离散控制 的优势被认知，生产工艺常由继电
器系统控制，然而，这种伺服控制在装配和布局上很繁琐，相对不长久 且不
能出来复杂信息
the performance requirements of their associated sensors a
nd transducers were correspondingly restricted to the supp
ly of simple data at a level capable of being utilized
by the
controllers. 与之相关的传感器和转换器的性能要求也相应被限定
在提供能被控制体利用范围内的简单数据。
there conditions were largely maintained with the intr
oduction of computer monitored, as opposed to controlled,
systems in which the computer was used primarily in a
supervisory role as a central machine receiving informat
ion sequentially from a number of radially connected outs
tations. with the advent of minicomputers such as the DE
C PDP series, computer controlled systems increased in bo
th number and scope, though they were limited in applica
tion by both processing power and cost. 这种状况由于与控制
相反的引入较大范围内得以保持，该系统中计算 机主要作为中央机承担监管
角色，不断从一系列线性相关的外部接收信息。随着DEC，PDP等系列微 型
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计算机的出现，计算机控制系统的数 量更大范围更广，尽管由于处理能力和
成本等因素使得他们的应用受到限
制。 more recently, sophisticated microprocessor systems ha
ve resulted in the complex interconnected designs that ar
e now found in both products and manufacturing processes.
最近，复杂微处理器以可编程的逻辑控 制和分布式嵌入式的微处理机系统
激起了错综复杂的内部联系设计，这些在产品和制造工艺中都能实习。
the growth in microelectronics and computing technologi
es from the mid 1970s that made available low cost proc
essing prower has resulted in a parallel growth in the
demand for information about system conditions. 从19世纪开
始随着微电子技术和计算机技术的发展，使低成本操作成为可能，也导致了
信息系统状况的平行增长。 in many cases this increased demand could not be m
et by existing sensors and transducers and resulted in t
he development of a range of advanced sensors and transd
ucers, often incorporating local processing power, either
integral with the sensing element on the same silicon sl
ice or in the form of a single chip microprocessor.在很
多场合下，现有传感器和转换器不能满足这种增长需求，而引起了 一系列高
级传感器和转换器的发展。他们通常配合局部处理能力，可能用于硅片上构
成传感器元 件或者以单片机形式存在。
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sensors, transducers and measurement传感器、转换器和测量
in any measurement system, sensors and transducers a
re used to provide information about system conditions. u
nfortunately, the usage of the terms sensor and transduce
r is complicated by the variety of different meanings ad
opted internationally, including in some instances an appa
rent interchangeability. for the purpose of this book the
following definitions are adopted: 在许多测量系统中，传感器
和转换器都被用于提 供系统状态信息。不幸的是，条件传感器和转换器的使
用被国际上五花八门的应用形式复杂化了，包括在 一些场合下明显的可互换
能力，处于这种目的，本书引入一下概念。
sensors that part of the measurement system that re
sponds to the particular physical parameter to be measure
d.传感器是测量系统的组成部分,能对特定的物理参数的测量。
Transducer That component of the system that transfers
information in
the form of energy from one part of the system to
another, including in some cases changing the form of
energy containing the information. 转换器 系统的这 个组成部分
以能量的形式将信息从系统的一部分传递到另一部分，包括在一些情况下改
变带有信 息的能量的形式
In addition to a sensortransducer, a measurement ma
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y include a pre-processing stage and a post- processing st
age, as shown in Fig. 20. 除了传感器、转 换器以外，一个测试系
统还可能包括前处理单元和后处理单元。如图20.1所示
The pre-processing stage serves to characterize the inform
ation in the incoming signal before presentation to the
sensing element. this then detects and responds to the p
hysical stimulus at its input and provides the input to
the transducers. The output signal from the transducer
is then operated on by the post-processing stage to prod
uce the final output The relationship between these stage
s is illustrated by the optical encoder used for speed
measurement shown in Fig. ，前处理单元在它把信息传给传 感器之
前描述输入信号的信息特征，然后检测并对其输入做出物理模拟响应，将输
入信号传送给 转换器。从转换器传出的信号被后处理单元处理后生成最终的
输出信号。这些单元之间的关系可以通过用 于速度测量的光学编码器来描
述。 20. 2. Here, the light from the sources is pre-pro
cessed by the slotted disc to produce a series of pulse
s. These light pulses received by the transducer which c
onverts the signal into a series of electrical pulses. t
he post-processing stage then counts the number of pulses
occurring in a defined time interval to determine the
speed of rotation of the shaft carrying the encoder.
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图20.2所示，这里，从 光源发出的光被标码的圆盘进行前处理，产生一系
列的脉冲，后处理单元通过计算在特定的时间间隔内的 脉冲数来确定带有编
码器的轴的转速。
As has been stated the physical basis for the transm
ission of
information by a transducer is that of energy transfe
r. This concept has been developed by Middelhoek to iden
tify six signal energy domains for the transfer of infor
domains are as follows： radiant,mechanical, t
hermal，electrical, magnetic and chemical. 如上 所述，转换器
传递信息的物理基础是能量传递，这个概念是由MIDDELHOEK发明的，用以
确定传递信息的六个信息能量领域，这些领域如下：光的、机械的、热的、
电的、磁的和化学的。
Of these, the
electrical output domain is the most significant in a

mechatronics context because of its information handlin
g capability, and transducer outputs in other domains may
well be further processed to transfer the information i
nto the electrical domain. 在这些领域中，电输出领域在机电一体
化领域中是最显著的，这是因为它的信息处理能 力，并且转换器在其他领域
的输出也被进一步处理成电信号来传递信息。
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Unit 23 what is “Mechatronics”?
“Mechatronics” is a term coined by the Japanese to describe the integration
of mechanical and electronic engineering .The concept may seem to be anything
but new, since we can look around us and see a myriad of products that utilize
both Mechanical and electronic disciplines .Mechatronics , however , specially
refers to a multidisciplined, integrated approach to product and manufacturing
system design. It represents the next generation of machines, robots, and smart
mechanisms necessary for carrying out work in a variety of environments-primarily,
factory automation,
译文：“机电一体化“是一个有日本人描述机械和电子集成的合成术语。这个概念看
上去不 再新颖，自从我们能观察四周和看到无数那些利用机械和电子学科的产品。机电
一体化，然而，特别是涉 及到许多学科，结合方法去生产和制造系统设计。他代表下一
代机械，机器人和灵巧机构必须执行工作在 各种环境，首要的，工厂自动化，办公自动
化，家庭自动化如图23.1所示。
By both implication and application, mechatronics represents a new level of
integration for advanced manufacturing technology and processes. The intent is
to force a multidisciplinary approach to these systems as well as to reemphasize
the role of process understanding and control. This mechatronic approach is
currently speeding up the already-rapid Japanese process for transforming ideas
into products.
译文：通过两个含义和应用，机电一体化代表了一个集成先进制造技术和过程 的新水
平。目的是将一个多学科的方法用到这些系统以及反复强调过程的作用的理解和控制。
这 个机械电子的方法目前加快了日本人已经将观念转化到产品的快速进程。
Currently, mechatronics describes the Japanese practice of using fully
integrated teams of product designers, manufacturing, purchasing, and marketing
personnel acting in concert with each other to design both the product and the
manufacturing system.
译文：目前，机电一体化阐述了日本人使 用充分结合的队伍的实践，这一队伍包括产
品设计者、制造人员、采购人员，他们相互一致行动，既设计 产品又设计制造系统。
The Japanese recognized that the future in production innovation would belong
to those who learned how to optimize the marriage between electronic and
mechanical systems. They realized, in particular, that the need for this
optimization would be most intense in application of advanced manufacturing and
production systems where artificial intelligence, expert systems, smart robots,
and advanced manufacturing technology systems would create the next generation
of tools to be used in the factory of the future.
日本人意识到生产 创新的未来会属于那些掌握了怎样使电子和机械系统结合得最
优的人。他们认识到在用人工智能，专家系 统，灵巧机器和先进制造技术来制造出将来
工厂要使用到的新一代工具的制造和生产系统，尤其需要这种 机电一体化的结合。
From the very beginnings of recorded time, mechanical systems have found their
way into every aspect of our society. Our simplest mechanisms, such as gears,
pulleys, springs, and wheels, have provided the basis for our tools. Our
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electronics technology, on the other hand, is completely twentieth-century, all
of it created within the past 75 years.
自有时间记录以来，机械系统出现在了我们社会的每一个方向 。我们最简单的机构，
例如：齿轮、滑轮、弹簧、和轮子，组成了人类工具的基础。在另一方面，我们的 电子
技术在过去的75年里创造了整个二十世纪。
Until now, the electronics were included to enhance mechanical systems’
performance, but the emphasis remained on the mechanical product. There had never
been any master plan on how the integration would be done. In the past, it had
been done on a case-by-case basis. More recently, however, because of the
overwhelming advances in the world of electronics and its capability to physically
simplify mechanical configurations, the technical community began to reassess
the marriage between these two disciplines.
直到现在，电子产品被用于提高机械系统的性能，而且强调保留在机械产品 中。在
怎样做一体化方面从来没有总体规划，在过去，它是在一件一件的基础上制作出来的。
然 而，近年来，由于电子世界重要的先进性和它对机械外形的物理简化能力，技术界开
始重新评估这两个学 科之间的结合。
The most obvious trend in the direction of mechatronic innovation can be observed
in the automobile industry. There was a time when a car was primarily a mechanical
marvel with a few electronic appendages.
在机电一体化改革方向最明显的趋势可以在汽车行业观察到。曾经有一段时间，汽
车主要是一个有几个电 子附件组成的机械奇迹。
First came the starter motor, and then the generator, each maiking the original
product a bit better than it was before. Then came solid-state electronics, and
suddenly the mechanical marvel became an electro-mechanical marvel. Today’s
macine is controlled by microprocessors, built by robots, and fault- analyzed by
a computer connected to its “external ieterface connector”. Automo- tive
mechanical engineers are no longer the masters of their creations.
首先是起动机电机，然后是发生器，每个制造的原 产品都比以前更好。然后是固体
电子学，突然变成了一个电气机械的奇迹。今天的机器是由微处理器控制 ，建立了机器
人，和故障分析的计算机连接到它的“外部接口连接器”。汽车的机械工程师不再是他们的创作大师。
The process that describes the evolution of the automobile is somewhat typical
of other products in our society. Electronics has repeatedly improved the
performance of mechanical systems, but that innovation has been more by
serendipity than by design. And that is the essence of mechatronics-the preplanned
application of, mechanical and electronics technology to create an optimum
product.
这个过程,描述了在我们的社会中汽车的进化过程中有些典型的其他产品。电子一再
提高机械系统的性能 ,但是,创新比设计更有可能。这是机电一体化应用的本质，机械和
电子技术来创造一个最佳的产品。
A recent U.S. Department of commerce report entitled “JTECH Panel report on
Mechatronics in Japan” compared U.S. and Japanese research and development
trends in specific areas of mechatronics technology. Except for a few areas, the
technology necessary to accomplish the development of the next generation of
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systems embodying the principles of mechatronics is fully within the
technological reach of the Japanese.
最近美国商 务部的报告题为“JTECH小组报告日本的机电一体化“相比美国和日本在特
定领域的机电一体化技术 的研究和发展趋势。除了少数地区,开发下一代系统需要创新技
术体现机电一体化的原则上是必须在其技 术达到的日本的程度
Comparisons were made in three categories: basic research, advanced
development,，and product implementation. Except for machine vision and software,
Japanese basic research was comparable to the United States, with the Japanese
closing in fast on machine vision system technology.. Japanese artificial
intelligence research is falling behind, primarily because the Japanese do not
consider it an essential ingredient of their future systems, they appear capable
of closing even that gap, if required . In the advanced development and product
implementation areas, Japan is equal to or better than the United States, and
is continuing to pull ahead at this time .
特别是在三个 方面:基础研究、先进的开发,和产品实现。除了机器视觉和软件,日本的基
本研究与美国的相提并论, 日本的机器视觉系统技术开发的较快. .日本的人工智能研究
落后,主要是因为日本不考虑这是他们的 未来的一个重要组成部分,他们表现出的系统关
闭甚至差距,如果需要。在先进的开发和产品实现地区、 日本接近或优于美国,将领先在
一段时间
The Department of Commerce report concluded that Japan is maintaining its position
and is in some cases gaining ground over the United States in the application
of mechatronics. Their progress in mechatronics is important because it addresses
the very means for the next generation of data-driven advanced design and
manufacturing technology. In fact, the Department of Commerce report concludes
that this has created a regenerative effect on Japan’s manufacturing industries.
To close the gap, we will need to go much further than creating new tools. If
we accept the fact that mechanical systems optimally coupled with electronics
components will be the wave of the future, then we must also understand that the
ripple effect will be felt all the way back to the university, where we now keep
the two disciplines of mechanics and electronics separated and allow them to meet
only in occasional overview sessions. New curricula must be created for a new
hybrid engineer---a mechatronics engineer. Only then can be assured that future
generations of product designers and manufacturing engineers will fully seek
excellence in these new techniques.
商务部报告结束后日本保持它的地位，和在某些情况下美国在机电一体化技术的应用
程序中获得地位。他 们在机电一体化方面的进展是重要的，因为它涉及的数据驱动的下
一代是手段先进的设计和制造技术。事 实上，商务部报告的结论造成了对日本制造业再
生的影响。
为了减小差距，我们需要进一 步研究而不仅仅是制造新的机器，如果我们接受机械系统
优化和电子元件将是未来的趋势，那么我们就不 得不明白，它在大学中的的连锁反应，
大学里，现在我们将机械学科和电子学科分离，而仅仅在偶然的会 议上才会碰面，所以
作为一个新的复合工程师，必须建立一门课程——机电一体化工程师，只有这样，我 们
才能够确保将来的产品设计师和制造工程师能够利用好这些新技术。
We need to rethink our present-day approach of separating our engineering staffs
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both from each other and from the production engineers. Living together and
communicating individual knowledge will create a new synergistic effect on
products. Maximum interaction will be the key to optimum designs and new product
development.
我们需要重新思考我们今天的做法，我们的工程技术人员都从对方 从生产工程师分离。
个人知识的共同生活和沟通，将创建一个新的产品协同效应。最大程度的互动将是最 佳
的设计和新产品开发的关键
The definition of mechatronics is much more significant upside down. It will
change the way we design and produce the next generation of high technology
products. The nation that fully implements the rudiments of mechatronics and
vigorously pursues it will lead the word to a new generation of technology
innovation with all its profound implications.
机电仪一体化的定义是更加重大颠倒的。它将改变我们设计并且引起高 科技产品的下
一代的方式。国家，充分实现了机电一体化技术的基本原理和大力追求它将带领这个词对一代新的技术创新具有其深远的影响。
Unit 25 Robots (1)
Industrial robots became a reality in the early 1960’s when Joseph
Engelberger and George Devol teamed up to form a robotics company they
called “Unimation”.(工业机器人在1960 年初成为了现实，是由约瑟
夫· 和乔治·德沃尔联合起来形成一个他们叫的机器人技术
公司。)
A robot is not simply another automated machine.(机器人不只是另
一个自动化机械。)Automation began during the industrial revolution
with machine that performed jobs that formerly had been done by human
workers. (自动化开始于机器工业革命期间，它能够执行以前人类工人的作
业。) Such a machine, however, can do only the specific job for which
it was designed, whereas a robot can perform a variety of jobs.
(这样一台机器，然而，只能做给它的设计的具体的工作，而一个机器人可
以执行各种作业。)
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A robot must have an arm. (机器人必须有一个手臂。) The arm must
be able to duplicate the movements of a human worker in loading and
unloading other automated machine, spraying paint, welding, and
performing hundreds of other jobs that cannot be easily done with
conventional automated machine. (手臂必须能够复制 一个人的工人在装
卸等自动化机器，喷漆，焊接，以及执行成百上千的其他不能很容易地完成
传 统的自动化机器的作业。)
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Definition of A Robot
The Robot Industries Association (RIA) has published a definition
for robots in an attempt to clarify which machines are simply automated
machines and which machines are truly robots.（ 机器人工业协会 (RIA)
发表了一个定义为机器人，试图澄清哪些机器是只是自动化的机器和哪些机
器是真 正的机器人。） The RIA definition is as follows:（RIA 的定义，
如下所示：）
A robot is a reprogrammable multifunctional manipulator designed
to move material, parts, tools, or specialized devices through
variable programmed motions for the performance of a variety tasks.
（机器人就是一种可重复编程的多 功能操纵器，旨在通过各种任务的性能变
量编程议案移动材料，零件，工具或专用设备。）
This definition, which is more extensive than the one in the RIA
glossary at the end of this book, is an excellent definition of a robot.
（这一定义，这是比一个在这本书的末尾的 RIA 词汇表中更广泛，是一种
优秀的机器人定义。）We will look at this definition, one phrase at
a time, so as to understand which machines are in fact robots and which
machines are little more than specialized automation.（我们将着眼
于这一定义，在一段时间内这都是一个 短语，只要去了解哪些机器其实是机
器人及哪些机器仅仅是特殊的自动化机械。）
First, a robot is a “reprogrammable multifunctional manipulator.”
（ 首先，机器人是“可再程序化的多功能操作器”。）In this phrase RIA
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tells us that a robot can be taught (reprogrammed) to do more than
one job by changing the information stored in its memory. （RIA 中
这句话告诉我们一个机器人可以通过更改其内存中存储的信息来 教授（再次
编程）它去做多个作业。） A robot can be reprogrammed to load and unload
machines, weld, and do many other jobs (multifunctional). （机器人
可以被重新编程去加载和卸载机器，焊缝，和做很多其他工作(多功能。) A
robot is a “manipulator”.（（机器人是一种机械手，能够用手臂 （或
手）去拿起或移动东西。）A manipulator is an arm (or hand) that can
pick up or moving things. At this point we know that a robot is an
arm that can be taught to do different jobs.（在这一点上我们知道一
个机器人相当于一只手臂，可以教给它做不同的工作。）
The definition goes on to say that a robot is “designed to move
material, parts, tools, or specialized devices”.（该定义上说，机
器人“旨在移动材料，零件，或者特殊 的设备”。）Material includes wood,
steel, plastic, cardboard... anything that is used in the manufacture
of a product.（材料包括木材，钢材，塑料，纸板...用于制造一个产品的
任何东西。）
A robot can also handle parts that have been manufactured. （机
器人还可以处理已经生产的零件。） For example, a robot can load a piece
of steel into an automatic lathe and unload a finished part out of
the lathe.（例如，一个机器人可以加载一块刚到自动车床和从车床上卸载
一个已经完成的零件。）
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In addition to handling material and parts, a robot can be fitted
with tools such as grinders, buffers, screwdrivers, and welding
torches to perform useful work.（除了处理材料和零件，一个机器人可
配备工具，如磨床、 缓冲剂，螺丝刀，和焊接气炬来执行有用的工作。）
Robots can also be fitted with specialized instruments or devices
to do special jobs in a manufacturing plant.（机器人也可以配备特殊
的仪器或设备在制造工厂做特殊的工作。）Robots can be fitted with
television cameras for inspection of parts or products.（机器人可
以装有电视摄像机，用于检查零件或产品。）They can be fitted with lasers
to accurately measure the size of parts being manufactured.(它们可
以配用激光准确地测量所制造的部件的大小。)
The RIA definition closes with the phrase, “…through variable
programmed motions for the performance of a variety of tasks.”( RIA
定义接近一个短语，“...... 通过可变的编程的运动给各种各样的任务”。)
This phrase emphasizes the fact that a robot can do many different
jobs in a manufacturing plant. (这句话强调的事实是一个机器人在制造
工厂可
以做很多不同的工作。)The variety of jobs that a robot can do is limited
only by the creativity of the application engineer.(机器人可以做的
各种工作只能由应用工程师的创造力来限制的。)
Jobs for Robots
Jobs performed by robots can be divided into two major categories:
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hazardous jobs and repetitive jobs.（由机器人来完成的工作可以分为
两个主要类别： 危险作业和重复性作业。）
Hazardous jobs
Many applications of robots are in jobs that are hazardous to humans.
（机器人的许多应用程序是在对人类有危险的工作。）Such jobs may be
considered hazardous because of toxic fumes, the weight of the
material being handled, the temperature of the material being handled,
the danger of working near rotating or press machinery, or
environments containing high levels of radiation.（这些工作可被认
为是有危险的，由于有毒烟雾，被处理的 材料的重量，被处理的材料的温度，
这些工作附近的旋转或重压的机械，或含有高剂量辐射的环境中。）
Repetitive Jobs
In addition to taking over hazardous jobs, robots are well suited
to doing extremely repetitive jobs that must be done in manufacturing
plants. （除了接管危险的工作，机器人很适合于在制造厂做重复的但必须
做工作。）Many jobs in manufacturing plants require a person to act
more like a machine than like a human. （许多工作在制造厂要求，更
像是一台机器，不是像人一样的人。）The job may be to pick a piece up
from here and place it there. （这份工作可能从这里接一片，并将其放
置在那里。））The job requires little or no judgment and little or
skill. （工作的要求很少或没有判断和小到不要技能。）The same job is
done hundreds of times each day. （同样的工作是做数百次的每一天。）
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This is not said as a criticism of the person who does the job, but
is intended simply to point out that many of these jobs exist in
industry and must be done to complete the manufacture of products.
（这不是一个批评对做工作的人，但纯粹为了指出 这些作业的许多行业中存
在和必须完成才能完成产品的生产。）A robot can be placed at such a work
station and can be perform the job admirably without complaining or
experiencing the fatigue and boredom normally associated with such
a job.(机器人可以放在这种工作站，并且可以极 好的执行作业而没有抱怨
或者通常的疲劳和厌烦这样一份工作的体验。)
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