-
(1)
Today
’
s
average
car
contains
more
than
15,000
separate,
individual
parts
that
must
work
parts
can
be
grouped
into four major categories: body, engine, chassis
and electrical equipment
。
<
/p>
当今的车辆一般都由
15000
多个分散
、独立且相互配合的零部件组成。这些零部件主要分为四类：车身、发动机、底
盘和电气
设备。
(2) The body is designed
to keep passengers safe and comfortable. The body
styling provides an
attractive,
colorful, modern appearance for the vehicle.
车身的设计要保证乘客安全舒适。车身的款式使得汽车看起来漂亮迷人、色彩斑斓、时
尚前卫。
1)
Engines used in automobiles are internal
combustion heat engines. They convert the chemical
energy of the gasoline into
heat within
a power chamber that is called a combustion
energy released in the combustion chamber raises
the
temperature of the combustion gases
within the chamber. The increase in gas
temperature causes the pressure of the gases to
increase.
The
pressure
developed
within
the
combustion
chamber
is
applied
to
the
head
of
a
piston
to
produce
a
usable
mechanical force, which is then
converted into useful mechanical power.
2) Linking the piston by a connecting
rod to a crankshaft causes the gas to rotate the
shaft through half a turn. The power stroke
this control of gas movement
is the duty of the valves; (Page 10)
活塞
通过连杆和曲轴连接，使得气体带动曲轴旋转半圈。作功冲程耗尽了所有的气体，这样就必须采取相应的措施排<
/p>
出废气以及向气缸内再充入新鲜的可燃混合气：气体的运动由气门来控制。
1)
The
engine
block
is
the
basic
frame
of
the
engine.
All
other
engine
parts
either
fit
inside
it
or
fasten
to
it.
It
holds
the
cylinders, water jackets, and oil
galleries. The engine block also holds the
crankshaft, which fastens to the bottom
of the block. (Page 13)
缸体是发动机的基体。发动机其它
的部件都安装或固定在缸体上，包括气缸、水套和油
道，以及固定在缸体底部的曲轴等。
2) Cylinder sleeves are used in engine
blocks to provide a hard wearing material for
pistons and piston rings. The block can be
made of one kind of iron that is light
and easy to cast while the sleeves uses another
that is better able to stand up wear and tear.
There are two main types
of
sleeves: dry and wet. (Page 10)
缸体中的气缸套
为活塞和活塞环提供了一种坚硬耐磨的材料。缸体可以采用某种重量轻且易铸造的铁来制造，而缸套
使用的却是另一种更加耐磨损的材料制
成。主要有两种类型的气缸套：干缸套和湿缸套。
3)
The
cylinder
head
fastens
to
the
top
of
the
block,just
as
a
roof
fits
over
a
house.
The
underside
forms
the
combustion
chamber with the
top of the piston. In-line engines of light
vehicles have just one cylinder head for all
cylinders; larger in-line
engines
can have two or more. (Page 14)
气缸盖安装在缸体的顶部，就像安在房子上的屋顶一样。缸盖的下方和活塞顶部形成燃烧室。轻型车上使
用的直列发
动机，所有气缸仅有一个气缸盖，较大的直列发动机有两个或更多缸盖。
4) The oil pump in the
lubricating system draws oil from the oil pan and
sends it to all working parts in the engine. The
oil
drains
off
and
runs
down
into
the ,
there
is
constant
circulation
of
oil
between
thepan and
the
working
pats
of
the
engine. (Page 15)
润滑系的机油泵从油底壳抽出机油，并把机油输送给发动机的所有工作部件。机油从油底壳流进流出。
因而在油底壳
和发动机的工作部件之间就有机油定向循环流动。
1)
Most
pistons
are
made
from
cast
aluminum.
Thepiston,
through
the
connecting
rod,
transfers
to
the
crankshaft
the
force
created
by the burning fuel mixture. This force turns the
crankshaft. (Page 17)
大多数活塞由铝铸造而成。通过连杆的
作用，活塞把可燃混合气燃烧产生的力传递给曲轴，带动曲轴旋转。
2) In diesel engines, the combustion
chamber may be formed totally or in part in the
piston crown, depending on method of
injection. (Page 18)
柴油机发动机根
据喷油方法不同，活塞头部可以形成全部燃烧室，也可以是燃烧室的一部分．
3) In modern engines, each piston has
three rings. (Piston in older engines sometimes
had four rings, or even five.)The inside
surface of the ring fits in the groove
on the piston. The ring's outside surface presses
against the cylinder walls.
在新型发动机上，每个活
塞有三个活塞环。
（在老式发动机上，每个活塞有四个甚至五个活塞环）环的内侧装在活
塞的
环槽里，环的外表面紧压在气缸壁上。
The cam is an egg-shaped piece of metal
on a shaft that rotates in coordination with the
crankshaft. The metal shaft, called the
camshaft, typically has individual cams
for each valve in the engine. As the camshaft
rotates, the lobe, or high spot of the cam,
pushes against parts connected to the
stem of the valve. This action forces the valve to
move downward. This action could open
an inlet valve for an intake stroke, or
open an exhaust valve for an exhaust stroke.
凸轮是一个蛋形的金属块，它安装在同曲轴协调运转的一根轴上，该轴称为凸轮轴，其上有同发动机 每一个气门对应
的凸轮。当凸轮轴旋转时，凸轮的最高点，也就是凸圆，推动连接气门杆
的部件，使得气门向下运动，在进气冲程打
开进气门，在排气冲程打开排气门。
In this arrangement, the cam
lobes push against round metal cylinders called
cam follower. As the lobe of the cam comes up
under the cam follower, it pushes the
cam follower upward (away from the camshaft). The
cam follower rides against a push
rod,
which pushes against a rocker arm. The rocker arm
pivots on a shaft through its center. As one side
of the rocker arm
moves up, the other
side moves down, just like a seesaw. The downward-
moving side of the rocker arm pushes on the
valve stem to open the valve.
（
p27
）
在这种方案中，凸轮凸圆推动圆形的金属筒，也就是挺柱。凸轮凸圆运动到挺柱下方时，
推动挺柱远离凸轮轴向上运
动。挺柱带着推杆，推杆推动摇臂，摇臂绕摇臂轴的中心转动
。摇臂的一端升起，另一端就落下，这类似于跷跷板。
摇臂向下运动的一端推动气门杆打
开气门。
When the engine runs in
compression stroke and power stroke, the valves
must close tightly on their seats to produce a
gas-tight
seal
and
thus
prevent
the
gases
escaping
from
the
combustion
chamber.
If
the
valves
do
not
close
fully
the
engine
will
not
develop
full power. Also the valve heads will be liable to
be burnt by the passing hot gases, and there is
the likelihood of the
piston crown
touching an open valve, which can seriously damage
the
engine.
（
p28
）
当发动机在压缩冲程和作功冲程工作时，气门必须紧贴在气门座上，形成良好的气密性以
防止燃烧室漏气。如果气门
关闭不严，发动机就不能发挥出全部的功率。而且气门头部容
易被经过的高温气体烧蚀，活塞顶部也可能会碰到气门
使发动机严重损坏。
1) Gasoline must vaporize easily.
This characteristic, called volatility, is
important. However, it must not vaporize too
easily, or
it will turn to vapor inside
the fuel tank or fuel lines. Inside the fuel line,
fuel vapor may block the flow ofliquid gasoline.
This
is called vapor lock. Vapor lock
is common in fuel lines where the inlet side of
the pump is exposed to high temperatures.
< br>汽油应易于蒸发，这个重要的特性称为挥发性。但是汽油也不能挥发得过快，不然它会在油箱或油管里转变 为蒸气。
在油管中汽油蒸气会阻碍液态汽油的流动，这称为气阻。汽油泵的入口处易受高
温，就经常出现气阻。
2)
Increasing
the
pressure
of
the
fuel
mixture
in
the
combustion
chamber
before
ignition
helps
to
increase
the
power
of
an
engine. This is done by compressing the
fuel mixture to a smaller volume.
在点火前增
加燃烧室内可燃混合气的压力有助于提高发动机的功率，这是通过把可燃混合气压缩到一个极小的体积来
实现的。高的压缩比不仅可以增加功率，而且会带来更多的有效功率。但随着压缩比的增加，爆震
的可能性也会增加。
Higher
compression
ratios
not
only
boost
power
but
also
give
more
efficient
power.
But
as
the
compression
ratio
goes
up,
knocking
tendency increases.
3)
Two
primary
standard
reference
fuels,
normal
heptane
and
iso-octane
arbitrarily
assigned
0
and
100
octane
number,respectively,
are then blended to produce the same knock
intensity as the test sample. The percentage of
iso-octane in
blend is considered the
octane number of the test , if the matching
reference blend is made up of 15% nheptane and
85% isooctane, the test sample is rated
85 motor or research octane number, according to
the test method used.
两种基准参考燃料正庚烷和异辛烷分别
被定义成辛烷值为
0
和辛烷值为
100
，
将它们混合产生与实验样本相等敲缸强度
的爆震。混合物中异辛烷的百分比就认为是实验样本的辛烷值。这样，依照实验方法，如果匹配的参考混合物 由
15%
的正庚烷和
85%
异辛烷组成，那么按照所用的实验方法，对比实验样本的辛烷值就是
85
4) Fuel pump: Most cars today have a
mechanical fuel pump. This pumps fuel out of the
tank and through the fuel lines to the
carburetor or injection system. In most
cars, the pump is mounted on the engine block.
Some cars have an electric fuel pump.
This pump mounts in the fuel tank with
the fuel pickup and the fuel-gauge-sending unit. <
/p>
当前大多数汽车采用机械汽油泵，汽油泵从油箱抽出汽油，通过油管送到化油器或喷射系统
。大部分汽车的汽油泵安
装在缸体上。一些汽车采用电动汽油泵，汽油泵安装在油箱上，
附带有油量传感器和燃油表油量传送装置。
5) Fuel
pump: The rotation of the lobe moves a rocker arm
in the pump. Inside the pump, a flexible diaphragm
connects to the
rocker arm though a
diaphragm spring,pull rod and link.
凸圆旋
转带动油泵中的摇臂运动。油泵中可变形膜片的泵膜通过膜片回位弹簧和膜片拉杆与摇臂相连。
< br>
1) (P.46) Diesel engine gets this
name from the pioneer work done by Dr Rudolf
Diesel. The diesel is used for the majority of
heavy
vehicles
and
the
excellent
fuel
economy
makes
it
an
attractive
alternative
to
the
petrol
engine
for
light
commercial
vehicles,
delivery vans and taxis.
柴油发动机的名称来源于
Rudolf
Diesel
博士所完成的开拓性工作。大多数重型车辆使用柴油，优良的燃油经济性
使得
柴油机成为具有吸引力的替代品
,
来代替轻型商用车、厢式运输货车和出租车上汽油机。
2)
(P.48)
As
diesel
engines
always
deal
with
interior
mixture
formation
only
a
heterogeneous
mixture
is
obtained
in
the
combustion
chamber.
In
heterogeneous
mixtures
the
excess-air
factor
λ
extends
from
pure
air
in
the
spray
periphery
(l=
infinite) to pure fuel
in the spray core (l= 0).
由于柴油机总是只在气缸内部
形成可燃混合气，在燃烧室内就会得到不均匀的混合气。不均匀混合气的过量空气系数
范
围从喷射外围纯空气的无穷大到喷射中心纯燃料的零。
3)
(P48) The fuel-injection system on a diesel engine
must do a number of important things. First, it
must meter the correct
amount of fuel
to run the engine at the speed and load demanded
by the driver. Then it must deliver the metered
fuel equally to
all cylinders, at
exactly the right time. Next, it must inject the
fuel at the correct rate and spray pattern for the
best burning in
the combustion chamber.
(P48)
柴油机的燃油喷射系统要完成许多重要的工作。首先，它必须定量供应准确
数量的燃油，使发动机在驾驶员所要求的
转速和负荷条件下运行。然后，它必须准确地在
恰当的时刻把定量供应的燃油平均分配给每一个气缸。为使燃烧室中
燃料燃烧效果最好，
它又必须以准确的速度和喷射方式喷油。
With the
injector pump on the low part (base circle) of the
camshaft, the inlet and spill ports are open. This
allows fuel to flow
at 268 kPa into the
venturi on top of the plunger. As the camshaft
turns, the lobe moves the plunger upward. This
raised the fuel
pressure, forcing fuel
through the delivery valve and on through the
lines. The lobe continues to move the plunger
upward to a
point where the spiral
groove in the plunger uncovers the spill port in
the venturi. At this point, fuel above the plunger
drains
through the spill port. This is
the end of injection. (P.49)
当喷油泵处于凸轮轴基
圆时，进油孔和回油孔都打开，柴油以
268KPa
的压力流入
柱塞上方的柱塞腔。凸轮轴旋转时，
凸圆使柱塞向上移动，油压增加，柴油从出油阀流出
送入高压油管。凸圆继续推动柱塞向上移动，直到柱塞运动到螺
旋槽打开柱塞腔上的回油
孔时的位置，此时，柱塞上方的柴油从回油孔流出，喷油过程结束。
1) Dry Friction Clutch
When
a
vehicle
is
to
be
moved
from
rest
the
clutch
must
engage
a
stationary
gearbox
shaft
with
the
engine;
this
must
be
rotating at a high speed
to provide sufficient power or else the load will
be too great and the engine will stall (come to
rest).
当汽车原地起步时，离合器要将静止的变速器轴同发动机接合起来，此时
发动机必须高速旋转以提供足够大的功率，
否则载荷过大将引起发动机熄火。
2
）
The
driving member
（主动部分）
The driving member consists of two
parts: the flywheel and the pressure plate. The
flywheel is bolted directly to the engine
crankshaft and rotates when the
crankshaft turns. The pressure plate is bolted to
the flywheel. The result is that both flywheel
and pressure plate rotate together.
主动部分由飞轮和压盘两部件组成。飞轮用螺栓直接连接到发动机曲轴上，随曲轴旋转而旋转。
压盘与飞轮连接，这
样飞轮和压盘一起旋转。
1) The modern automobile engine is a
powerful, lightweight, and dependable powerplant.
However, it is not perfect for three
reasons.
新型的汽车发动机是一个动力强劲、质量轻
便而且性能可靠的动力装置。然而它美中不足有三个原因。
3)Sliding-mesh
transmission(
滑动啮合变速器
):
In the case of a sliding-mesh gearbox,
gear changing demands skill if noise is to be
avoided. Crashing (or clashing) of the gears
as the result of a bad change suggests
the reason why this type is often called a 'crash'
type gearbox. (P.79)
对滑动啮合变速器来说，换挡时要避免噪
声是需要技巧的。齿轮打齿是由换挡不当引起的，这也是滑动啮合变速器经
常被称为“碰
撞”型变速器的原因。
4) Constant-mesh
transmission(
常啮合变速器
)
< br>（
P.79
）
This type uses helical or double
helical gears which are always in mesh. The
mainshaft gear wheels are mounted on bearings
and when a gear is required the
mainshaft gear is locked to the shaft by a dog
clutch.
常啮合变速器采用斜齿轮或人字形齿轮，这些齿轮总是处于啮合状态。
输出轴上的齿轮安装在轴承上，换挡时爪形
/
牙
嵌式离合器（接合套）使输出轴齿轮和输出轴锁止在一起。
5) Although the mechanical efficiency
is lower the helical gears are quieter and any
damage resulting from a bad gear change