锻造操作机行走系统液压冲击振动及定位控制

Hydraulic shock vibration and positioning control for forging manipulator walking system

针对锻造操作机大车行走系统在停止时刻液压冲击振动噪声大、定位不准确等问题,分析产生液压冲击和定位不准的原因,建立了大车行走液压系统数学模型,提出在大车位移到达目标值精度范围临界点时,控制策略由PID控制切换为比例方向阀零控制信号,并在靠近行走液压马达进出油口背向并联二次溢流阀组,设置阻尼孔连通液压马达进出油口,通过AMESim平台进行仿真分析对比。结果表明:切换控制策略结合二次溢流阀组和连通阻尼孔的硬件补偿措施,可以隔离高压油源和快锻压机锻压工件的反作用力对大车行走马达的影响,有效降低操作机停止时刻液压冲击振动,提高系统阻尼比,加快液压冲击的衰减,提高大车定位精度。

For the problem of loud noise of hydraulic shock vibration and inaccurate positioning for forging manipulator walking system at stopping time, the causes were analyzed, and the mathematical model of hydraulic system for cart walking was established. Then, the method for switching the control strategy from PID control to proportional directional valve zero control signal was proposed when the cart displacement reached the critical point of accuracy range of target value. Close to the inlet and outlet ports of walking hydraulic motor, the secondary relief valve group was back-to-parallel, and the damping hole was set between the inlet and outlet parts of the walking hydraulic motor. Furthermore, the simulation and comparison analysis were conducted by the platform AMESim. The results show that switching control strategy combined with the hardware compensation measures of the secondary relief valve group and the connecting damping hole can isolate the influence of high pressure oil source and reaction force of forging workpiece for fast forging press on the cart walking motor, reduce the hydraulic shock vibration effectively when the machine stops, improve the damping ratio of the system, speed up the attenuation of hydraulic impact, and improve the positioning accuracy of the cart.