?【编者按】 从本节开始我们进一步介绍发动机的分类及原理。

The engine is the heart of an automobile. The purpose of an automotive engine is to convert fuel into the energy that moves the automobile. Currently the easiest way to create motion from fuel is to burn the fuel inside an engine. Therefore, an automotive engine is an internal combustion engine, which burns fuel within the cylinders and converts the expanding force of the combustion into rotary force used to drive the automobile.

There are several types of internal combustion engines classified as reciprocating or rotary engine; spark ignition or compression ignition engine; and alternative-fuel engine or hybrid–electric vehicle.

【中文注解】

发动机是汽车的心脏，它的主要作用就是将燃料转化为驱动汽车行驶的能源。

发动机一般可以分为以下几种：往复式（旋转式）发动机、火花点火式（压燃式）发动机、替代燃料发动机、混合电力车辆等。

【延伸阅读】

* 汽车的心脏——发动机

* 发动机原理及详解之一

* 发动机原理及详解之二

* 发动机原理及详解之三

* 发动机原理及详解之四
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