“中南林业科技大学”热能与动力工程专业
“不落的星尘”全力打造，华丽的一个金币，传说中的物美价廉
发动机英文翻译、内燃机英文翻译、汽车英文翻译、热动英文翻译
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期待各位的指正，谢谢！
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…………分割线…………割了烦恼…………毕业愉快…………工作愉快……
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（本文来自《汽车专业英语》/陈勇、边明远主编）
The Engine’s System
The engine is an important part of the automobile; it acts as the heart of a person, which provides the power that the cars need to run on the road. All the automotive engines today are the Internal Combustion Engines ( ICEs ) becau the fuel is burnt inside their cylinders and the energy is provided.
ICEs are tho heat engines that burn their fuel inside the engine cylinder. In ICEs, the chemical energy stored in their fuel converted into heat energy during the burning part of their operation. The heat energy is converted into mechanical energy by the expansion of gas against the piston attached to crankshaft that can rotate. The engines that burn petrol are known as petrol engine. Other types of ICEs burn heavier oils, of the types the diel engine has come into the widest u.
Diel and petrol engines have the same mechanical parts, except that diel components are generally stronger and heavier. Both engines are internal combustion engines, but they have different fuel system and u different fuels. With a diel, only air enters the cylinder during the intake stroke. A petrol engine takes in an air-fuel mixture. Following are some general comparisons between diel and petrol engines:
In a diel, the fuel is injected into the cylinder as a fine spray near the top of the compression stroke. With a petrol engine, the fuel is injected into the exhaust ports at the start of the induction stroke.
Ignition in a diel is by the high temperature from the highly compresd air. A petrol engine needs a spark for ignition.
Diel engines generally operate at lower engine rpm than petrol engines.
Diel engines u distillate for fuel, which is less volatile than petrol.
The design of diel engines makes them noisier than petrol engines and they have a unique diel knock.
Small diel engines, as well as petrol engines, are ud in pasnger cars and light commercial vehicles. Larger diel engines are ud in all heavy commercial vehicles, earthmoving equipment, and farm machinery.
1. Engine Configurations
The term engine configuration refers to the way that the cylinders of an engine are arranged. The cylinders can be in-line, or at an angle ( V-type ). Within the three basic arrangements, there are a number of variations.
In-line engine
With in-line engines, the cylinders are arranged in a straight line, one behind the other. Most in-line engines have their cylinders vertical, but some are slanted. That is, the engine is tilted at an angle to reduce the overall height. The engines are sometimes referred to as slanted engines.
Some in-line engines have their cylinders horizontal, so that the engine is more or less on its side. This reduces the overall height of the engine. This arrangement is
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ud mainly in larger commercial vehicles with the engine mounted under part of the cab. The mechanical arrangement of a four-cylinder in-line for a pasnger car is shown in Fig.
1-9. The cut-away view in Fig.1-10 enables the various parts to be identified.
Horizontally oppod engine
This arrangement has its cylinders arranged in two flat blanks with the crankshaft between them. The engine shown has a short rigid crankshaft with five bearings. A horizontally oppod engine has even firing impuls and good balance. Movement of a piston in direction is oppod by movement of a piston in the opposite direction.
Horizontally oppod engines, with their flat design, give the engine a low height and also help to keep the center of gravity of the vehicle low. A low center of gravity gives the vehicle stability.
V-type engines
With V-type engines, the cylinders are arranged in two blanks at an angle. This reduces the length of the engine and makes it more compact. This also reduces the length of the crankshaft, which can be designed to be more rigid than a long shaft.
2. The Engine Asmbly and Components
The complete engine asmbly consists of the mechanical components that make up the engine itlf and also a number of associated systems. The are the systems that are needed to start the engine and also to control it and keep it running. The mechanical parts of the engine asmbly can be broken down into a number of sub-asmblies, or groups of associated components, although the are usually referred to merely as asmblies, for example, cylinder-head asmbly and piston asmbly. Some parts of an engine are internal, other parts are external, this illustration identifies a number of external parts.
