液压打桩锤主控阀换向性能的动态特性分析

为满足液压打桩锤高频工作下对换向快速性的要求,设计采用主控阀控制的快速换向柔性冲击系统。该阀通过4个控制口压力的变化控制阀芯的运动,通过内部反馈油孔实现对换向状态的记忆。根据主控阀换向工作基本原理,建立主控阀换向过程的动态数学模型,采用Stateflow处理换向过程的状态转换结合Simulink建立换向过程的仿真模型。结合实验的相关参数对主控阀换向过程进行仿真分析,仿真得到的换向所需时间和实验结果基本一致。利用仿真模型,分析内腔直径,内部反馈孔直径和长度以及弹簧刚度4个主要因素对主控阀换向性能的影响。研究结果表明:主控阀内腔直径对主控阀换向快速性的影响最大,内部反馈油孔直径和长度次之,弹簧刚度影响最小。

Dynamic analysis of main control valve reversing performance for hydraulic pile hammer

To make hydraulic pile hammer work at high frequencies when control system rapidly reverses,the main control valve was designed to realize the flexible control of the system with rapid reversing.The spool movement was controlled by pressure variation on four ports and the state of spool movement was remembered through inner feedback hole.According to the working principle of main control valve,the dynamic mathematic model of main control valve reversing was established.Using Stateflow to manage the state transfer of spool movement,the simulation model was presented in combination with Simulink.The simulation was done with parameters in the experiment and the reversing time required is in accord with the results of experiment.The effects of main parameters to reversing performance of main control valve were analyzed.The results show that inner chamber diameter has the greatest effects on reversing performance,the diameter of feedback hole was the second,the length of the feedback hole follow and the spring stiffness is the smallest.