电控发动机排气制动功能研究

Research of Braking Function of Electrically Controlled Engine Exhaust Valve

国内电控发动机传统的辅助制动方式采用蝶形阀开关关闭排气管通道的方法,使活塞在发动机某几个冲程受到压缩气体的阻力,阻止发动机运转而产生制动作用,达到控制车速的目的。EVB排气门制动是建立在传统蝶形阀排气辅助制动装置之上,利用电磁阀控制高压气路通断引起蝶阀偏转,同时电控单元控制发动机喷油以及其他执行器工作,在缓速过程中达到低排放、低能耗的目的。本论文重点研究了某型号发动机排气制动系统工作过程中相关部件的响应,结合电控单元控制逻辑讨论如何实现精确控制。

Traditionally, the butterfly valve is used in the domestic electrically controlled engine as an auxiliary braking mean to close the exhaust path so as to produce resistance onto the operating pistons, as result, lowering engine speed. The EVB （exhaust valve brake） is realized on the basis of the traditional butterfly valve. The solenoid closes or opens, activating the butterfly valve to move. At the same time, the electrically controlled unit controls the fuel injection and other actua- tors. This means may lower energy combustion and decrease emissions produced by the engine in the process of deceleration. This paper emphasizes on the research on the response of the relevant engine parts in the process of braking and discusses how to control the precise control via the control unit.