商用车气压驻车制动系统继动阀压力特性研究

Research on the pressure characteristics of the relay valve of the pneumatic parking brake system of commercial vehicle

为研究商用车气压驻车制动系统继动阀压力特性的影响因素,对驻车制动回路中的继动阀等主要部件进行数学建模,搭建了继动阀的压力响应仿真模型,并参照国际标准设计了继动阀压力特性试验台架;通过仿真与试验结果对比分析,两者数据的整体一致性比较好,证明仿真模型的准确性比较高;通过改变继动阀的进气口直径、进气阀门直径、控制口进气速率和相通气室初始容积进行仿真研究,分析其对继动阀压力特性的影响。结果表明:继动阀进气口直径越大,进气阀门直径越小,压力响应速度越快,当进气口直径超过10 mm时,对压力响应时间的影响不明显;继动阀控制口进气速率越快,相通气室初始容积越小,压力响应时间越短,当控制口进气时间变长时,压力波动越来越明显。研究结果可为继动阀的结构优化设计和系统匹配选型提供参考,有利于提高商用车气压驻车制动系统的制动性能。

The mathematical modeling of the main components such as the relay valve of the parking brake circuit was carried out,and the pressure response simulation model of the relay valve was built to study the influencing factors of the pressure characteristics of the relay valve of the pneumatic parking brake system of commercial vehicles.The relay valve pressure characteristic test bench was designed according to international standards.Through the comparative analysis of simulation and test results,the overall consistency of the two data was relatively good,which proves that the accuracy of the simulation model is relatively high.Simulation was conducted to analyze the influence on the pressure characteristics of the relay valve by changing the diameter of the air inlet of the relay valve,the diameter of the intake valve,the intake rate of the control port,and the initial volume of the phase ventilation chamber.The results show that the larger the diameter of the intake port of the relay valve,the smaller the diameter of the intake valve,and the faster the pressure response speed.When the diameter of the intake port exceeds 10 mm,the influence on the pressure response time is not obvious;The faster the air intake rate,the smaller the initial volume of the phase ventilation chamber,and the shorter the pressure response time.When the air intake time of the control port becomes longer,the pressure fluctuation becomes more and more obvious.The research results can provide a reference for the structural optimization design and system matching selection of the relay valve,which is beneficial to improve the braking performance of the commercial vehicle pneumatic parking brake system.