定量泵负载敏感系统卸荷压力冲击抑制研究

定量泵负载敏感系统在快速卸荷时容易出现压力冲击现象,对系统的可靠性和寿命产生较大危害。三通压力补偿阀是定量泵负载敏感系统中关键的调压元件,本文以三通压力补偿阀为切入点,建立定量泵负载敏感系统功率键合图模型,基于键合图模型推导系统的状态方程,建立Matlab动态仿真模型,探讨系统卸荷压力冲击的抑制方案。基于系统仿真模型,首先对系统卸荷压力冲击的仿真与试验进行对比,验证了仿真模型的正确性;然后,针对三通压力补偿阀的系统压力腔阻尼、阀芯直径、Ls腔阻尼、阀口锥角等关键参数,对卸荷压力冲击影响规律进行仿真;最后,基于关键参数对卸荷压力冲击影响规律的分析,提出了一种"小阀芯、双阀口"型三通压力补偿阀结构优化方案,并对其卸压冲击抑制效果进行了仿真和试验。结果表明,该方案可以有效抑制卸荷压力冲击,优化后系统卸压冲击压差比原系统降低了89%,卸荷压力降低了20%,进一步实现了节能。

Suppression of Unloading Pressure Shock in Load Sensitive System of Constant Displacement Pump

The load sensitive system of constant displacement pump is prone to pressure shock when unloading rapidly, which is harmful to the reliability and life of the system. As the three-way pressure compensation valve is the key pressure regulating element in the load sensitive system of constant displacement pump, the three-way pressure compensation valve was studied to find the suppression scheme of the system unloading pressure shock. Firstly, the power bond graph model of the system was built, and the state equation of the system were deduced. Then the dynamic simulation model of Matlab was established according to the state equation. After that, the correctness of the simulation model was verified by the simulation and test analysis of unloading pressure shock. The influences of the damping of pressure chamber, diameter of valve core, damping of Ls chamber and the cone angle of valve port on unloading pressure shock were analyzed by using the simulation model. Finally, based on the structure optimization of three-way pressure compensation valve, a new type of three-way pressure compensation valve with double valve ports was proposed, and it was verified that the valve could effectively suppress the unloading pressure shock. The simulation and experimental results showed that the new valve could effectively suppress the unloading pressure shock, and the optimized system reduced the unloading pressure shock by 89% compared with the original system, at the same time, it also reduced the unloading pressure by 20%, further realizing the energy saving.