韩占群^1,2，徐洋^1,2，赵国东^1,2，刘亚奇^1,2

（1.长城汽车股份有限公司技术中心，河北 保定 071000；2.河北省汽车工程技术研究中心，河北 保定 071000）

摘要：针对增压柴油机排气道及排气门积碳的现象，研究配气正时对燃烧以及积碳产生的影响。过多的缸内残余废气会导致燃烧缓慢，燃烧持续期变长，较大的排气提前角会导致缸内还未完全燃烧的混合物被排出气缸，废气经过长时间的积累，在排气门处与排气道内形成积碳。通过合理设置配气正时，减少缸内残余废气，加速燃烧过程，降低或避免积碳形成。

关键词：柴油机；气门正时；残余废气；积碳

Abstract: For the deposit phenomenon on exhaust ports and exhaust valves of turbocharged diesel engines, research about influence of valve timing on combustion and formation of deposit has been performed. The results show that too much in-cylinder residual gas leads to low combustion speed and longer combustion duration. Along with much earlier EVO, evaporated fuel in the cylinder will have no time to combust completely when being pushed out of the cylinder. After accumulating there will be deposits on exhaust valves and exhaust ports. By setting up suitable valve timing，in-cylinder residual gas can be reduced to reasonable level, leading to much faster combustion process. As a result deposits could be reduced or avoided.

Keywords：diesel engine；valve timing；residual gas；deposits