直接压电驱动水液压节流控制阀静态特性的仿真与试验

Design and static experiments of water hydraulic throttle valve with direct piezoelectric actuation

水的黏度低,水液压控制阀采用传统的电机械转换器,因润滑和密封问题其性能与油压元件差距大。压电驱动刚度大,响应快,精度高,能有效提高水液压控制阀的性能。采用球式座阀结构,通过设计合理的微调预紧机构、阀体和阀口,研制了直接压电驱动水液压节流控制阀。建立了直接压电驱动节流阀的仿真模型,仿真与静态试验结果表明,压电叠堆输入电压高时,控制阀具有相对较高的线性度;而压电叠堆输入电压低时控制刚度不足,受阀芯不平衡液压力影响,试验与仿真结果偏差大,控制阀性能不佳。采用座阀结构的水液压控制阀提高了阀口密封性,但在阀的设计和加工中应减小不平衡液压力。

The performance of water hydraulic control valves driven by traditional electromechanical converters is much lower than that of oil hydraulic control valves for the reason of poor seal and lubrication. The piezoelectric actuation is a new technology with fast response,high precision and control stiffness. The performance improvement could be obtained by applying piezoelectric stack in the water hydraulic control valve. Therefore,a novel water hydraulic throttle valve with direct piezoelectric actuation was developed through the design of ball seat valve structure,fine displacement adjustment and spring preloading device. The simulation model of the developed valve was built. The results of the static experiments and simulation show that the valve has good linearity as the input drive voltage of piezoelectric stack is high. However,the performance of the developed valve is poor with the effect of imbalance in hydraulic force on the valve core as the input voltage is low. This indicates that it is necessary to minimize the imbalance in hydraulic force while a water hydraulic valve with fine-sealing seat valve structure is designed and manufactured.