大功率水压比例卸荷阀功率级动态特性仿真研究

Simulation on dynamic characteristics of power stage of high power hydraulic proportional unloading valve

针对开关式电磁卸荷阀工作中压力冲击严重的问题,提出采用比例控制方式对泵站压力升降过程进行调节的方法,并设计了一种1 200 L/min,50 MPa的比例卸荷阀.针对功率级主阀大尺寸、大容腔等特点,采用功率键合图建立了数学模型,研究了主阀弹簧腔直径、阻尼孔直径、先导阀开度、主阀弹簧刚度和预紧力对主阀升压响应时间、卸荷响应时间和卸荷残余压力的影响规律.结果表明:卸荷响应时间与卸荷残余压力具有变化的一致性,而与升压响应时间呈反比例关系;在满足卸荷残余压力不大于1.2 MPa的基础上,可以确定各关键参数的优选值;最终升压响应时间为160 ms,卸荷响应时间为60 ms;在25%输出幅值状况下幅频宽为9 Hz,在100%输出幅值状况下幅频宽为3 Hz.

A proportional control method was proposed to adjust the pressure change process of the pump station in response to the serious pressure impact during the operation of the electromagnetic unloading valve.And a 1200 L/min,50 MPa proportional unloading valve was designed.Considering the large size and large capacity of the main valve,a mathematical model was developed by power bonding diagrams to investigate the effects of main valve spring cavity diameter,orifice diameter,pilot valve opening,main valve spring stiffness,and preload on main valve loading response time,unloading response time and unloading pressure.The research results show that the unloading response time is consistent with the unloading pressure,and it is an inherent contradiction with the loading response time.On the basis of satisfying that the unloading pressure is not greater than 1.2 MPa,the optimal value of each key parameter can be determined.The final loading response time is 160 ms,and the unloading response time is 60 ms.When the output amplitude is 25%,the amplitude bandwidth is 9 Hz,and when the output amplitude is 100%,the amplitude bandwidth is 3 Hz.