在探索研制高经济性与低排放量内燃机的途径时,专家们既努力改善其结构,又努力改善其工作过程。例如美国工程师米勒(Miller R)采用一种新的换气方法,以消除四冲程循环活塞行程与曲轴角速度严格对应的固定上、下“止点”的缺陷。其方法实质如下。在进气行程远未完成时,就将进气门关闭,而活塞继续朝下止点运动,气缸内形成一定的真空度。因此,在压缩行程开始时实际上并未进行压缩,稍后它才象常规发动机那样,开始进行压缩。因此,米勒将发动机的压缩行程分成两部分:无 While exploring ways to develop high-economy and low-emission internal combustion engines, the experts worked hard to improve their structure and strive to improve their work processes. For example, American engineer Miller R adopted a new ventilation method to eliminate the fixed upper and lower “dead center” defects that exactly match the stroke speed of the four-stroke cycle piston with the crank angle. The method is as follows. In the intake stroke is far from complete, the intake valve will be closed, while the piston continues to move down to stop the cylinder to form a certain degree of vacuum. Therefore, compression is not actually performed at the beginning of the compression stroke, and later it starts to be compressed just like a conventional engine. Therefore, Miller will be the engine compression stroke is divided into two parts: None