Independent volume-in and volume-out control of an open circuit pump-controlled asymmetric cylinder system

To avoid the flow asymmetry of a closed circuit pump-controlled asymmetric cylinder system, an efficient open circuit pump-controlled asymmetric cylinder system (OPACS) with an independent displacement volume-in and volume-out (VIVO) control method is proposed. The energy transmission path of the OPACS was analyzed, and an energy calculation model was built. A position-pressure combined control method was adopted to validate the proposed OPACS. Based on a 0.6-MN open circuit pump-controlled forging press system, a series of experiments with different return cylinder pressures were conducted. The experimental results confirmed that the proposed OPACS with the position-pressure combined control method was able to recover energy to reduce the installment power without sensitivity to the return cylinder’s pressure variation and that the position accuracy and rapidity could be improved by increasing the pressure in the return cylinder.中文概要目的为减少能量排放和提升节能效果,并解决非对称 缸系统的流量不对称问题,本文对开式泵控非对 称缸负载容腔独立控制系统的控制特性及能耗 特性进行了深入的研究,以期为其实际应用提供 理论支撑。创新点1. 提出开式泵控非对称缸负载容腔独立控制系 统,建立其能量传输模型;2. 以压机为对象进行 实验研究,采用位置压力负载容腔独立控制方 法,获得其能耗与控制特性。方法1. 介绍开式泵控非对称缸负载容腔独立控制系统 的构型;2. 通过理论推导,建立能量传输模型, 得到具有能量回收功能的系统;3. 通过实验研究 和分析,验证所提系统和方法的有效性。结论1. 基于能量传输模型得到的系统具有较好的节能 特性;2. 开式泵控非对称缸负载容腔独立控制系 统增加了系统控制自由度,验证了负载容腔独立 控制方法的有效性;3. 开式泵控非对称缸负载容 腔独立控制系统采用无杆腔位置控制和有杆腔 压力控制组合的控制方法;随着有杆腔压力的提 高,在不增加系统能耗的前提下该方法改善了系 统的位置控制精度。