王超1，梁善飞1，杨陈1，袁爽1，沈源1，王瑞平1,2
1.宁波吉利罗佑发动机零部件有限公司；
2.浙江吉利罗佑发动机有限公司
摘要:凸轮型线的设计对发动机的性能有重要的影响。 高速利用进气惯性，进气门迟闭可以有效的增加气缸充量，而较大的迟闭角可能会因为活塞的上移将气体推出气缸，减小气缸充量。同样，排气提前可以有效的降低缸内残余废气，使排气通畅；而较大的排气提前角可能会造成有效功的损失，并导致各缸间进排气干涉，减小气缸充量。在凸轮型线设计时，不仅要考虑型线本身的设计，同时更要兼顾进排气门开始时刻的影响。本文采用仿真分析的方法，更改不同方案的进排气门凸轮型线，并通过试验验证，确定最终结论的有效性。英文
关键词:发动机，气门升程，气门包角，气门重叠角
Abstract: The design of cam profile plays the important role in engine performance. Due to intake inertia, the intake valve closing retard effectivel increase air charging of an engine. But, if a closing retard angle is too large, gas maybe expelled from pistons while pistons move toward causing a decrease of air charging in cylinders. Meanwhile, the advanced opening of exhaust valves may effectively reduce the residual exhaust gas in cylinders and smooth the exhaust flow. If the advanced angle of the exhaust valves is too large, it may cause the loss of active power and the reduce in-cylinder air charging. Therefore, the influence of intake and exhaust closing time should be considered in the process of cam profile design. In the paper, the simulation method is used to change the plans for the design of the cam profiles of intake and exhaust valves. The test proved its validity.
Keywords: Engine; Valve Lift; Valve angle; Valve Overlap
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