液压驱动全可变气门机构的运动特性
孙常林1，谢宗法2，3*
1.潍坊职业学院汽车工程学院，山东 潍坊 261041；2.山东大学机械工程学院，山东 济南 250061；
3.山东大学高效洁净机械制造教育部重点实验室，山东 济南 250061
摘要：为改善高速工况下全可变气门正时机构性能，以某液压驱动全可变气门机构为例，采用ADINA软件对气门机构的气门运动规律及液压系统内压力波动进行计算流体动力学(computational fluid dynamics，CFD）仿真分析，并结合K157型发动机进行试验研究对比。结果表明：通过调节泄油相位角，气门正时机构仿真模型可实现配气相位、气门升程全可变；泄油相位角对气门运动规律影响较大，曲轴转速对气门运动规律的影响较小；液压系统压力波动大过严重影响机构的可靠性；基于理论分析，可从减小运动组件质量、采用直流道、增加气门弹簧的设计刚度及预紧力等方面，提高气门机构性能。
关键词：全可变气门机构；CFD；气门运动规律；压力波动
Motion characteristic of hydraulic driven fully variable valve mechanism
SUN Changlin1, XIE Zongfa2,3*
1. College of Automotive Engineering, Weifang Vocational College, Weifang 261041, China；
2. School of Mechanical Engineering, Shandong University, Jinan 250061 ,China;
3. Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, Shandong University, Jinan 250061, China
Abstract：In order to improve the performance of the fully variable valve timing mechanism under high-speed working conditions, taking a hydraulic driven fully variable valve mechanism as an example, ADINA software is used to perform computational fluid dynamics (CFD) simulation analysis on the valve motion law and pressure fluctuations in the hydraulic system of the valve mechanism, and experimental research and comparison are conducted with the K157 engine. The results show that by adjusting the oil leakage phase angle, the simulation model of the valve timing mechanism can achieve fully variable valve timing phase and valve lift. The phase angle of oil leakage has a significant impact on the valve motion law, while the crankshaft speed has a relatively small impact on the valve motion law. Excessive pressure fluctuations in the hydraulic system seriously affect the reliability of the mechanism. Based on theoretical analysis, the performance of the valve mechanism can be improved by reducing the mass of the moving components, adopting a DC channel, increasing the design stiffness and preload of the valve spring, and so on.
Keywords:fully variable valve mechanism; CFD;movement of valve;pressure fluctuation
