尹子明1, 余伟1, 张春丽1, 黄黎明2

1.奇瑞汽车股份有限公司动力系统技术中心，安徽 芜湖 241000；

2.博格华纳汽车零部件有限公司，上海 201100

摘要：对某直喷汽油机正时系统进行仿真计算和试验验证。优化凸轮轴设计，调整燃油泵凸轮相对凸轮轴凸轮的角度，将燃油泵扭矩峰值滞后凸轮轴扭矩峰值的角度由72°调整到125°，使合成扭矩峰值最小，降低对正时系统负载影响。仿真结果表明，链条张力和张紧器柱塞位移均达到设计标准，系统运行稳定；发动机正时系统功能测试结果表明，凸轮轴优化后，链条对固定导轨的振动加速度从270g（g为重力加速度）降低到100g；链条最大张力满足强度要求；张紧器柱塞位移在发动机转速范围内小于3 mm，稳定工况下小于0.5 mm。仿真和测试结果接近，优化后的凸轮轴链条负载大幅度降低，张紧器工作稳定，能够控制整个系统平稳运行，凸轮轴优化合理，达到了设计目标。

关键词：缸内直喷；高压油泵；正时系统；合成扭矩；凸轮轴优化

Abstract:In terms of a fuel pump used for gasoline direct injection (GDI) engine, the angle between fuel pump lobe and camshaft lobe is adujsted, and the fuel pump peak torque retarded camshaft peak torque is set from 72° to 125°,in order to minimize the resultant torque and reduce the effect to chain load. By numerical simulation of timing drive system, two main features,chain force and piston motion satisfy design specification. The test results show the optimized camshaft reduce the vibration acceleration of chain guide from 270 g to 100 g, which means the adjusted fuel pump lobe angle is effective. The chain drive test results show, the chain max force meet the strength requirement and the tensioner piston motion less than 3 mm for all engine speeds and less than 0.5 mm in the steady speed. Both the simulation and test results show that the chain load reduced with optimized camshaft and tensioner work steadily, theoptimized camshaft is reasonable and the system runs smoothly which meet the initial design target.

Keywords:GDI；high pressure fuel pump；timing drive system；resultant torque；camshaft optimization