变量泵、比例阀和蓄能器复合控制差动缸回路原理及应用

提出用单台变速泵或伺服泵,结合蓄能器和旁通比例节流阀复合控制差动缸,改善注塑机能量效率的回路原理。液压泵仅在液压缸进给过程工作,蓄能器存储液压缸运动和制动过程的能量并用作液压缸回程的动力。比例节流阀控制液压缸回程的运动速度,通过新提出的流量校正原理,消除蓄能器内压力变化和负载对阀流量的影响,使液压缸的速度能够实时跟踪预定的轨迹。同正反向都采用泵驱动的原理相比,可消除回程中电动机制动产生的能耗。研究表明,新的回路原理可满足注塑机控制性能的要求。

PRINCIPLE AND APPLICATION OF DIFFERENTIAL CYLINDER SYSTEM CONTROLLED WITH DISPLACEMENT PUMP, ACCUMULATOR AND PROPORTIONAL VALVE

The principle to control the differential cylinder with one servo pump or a speed variable pump, accumulator and proportional throttle valve together is put forward to improve the efficiency applied to control the plastic injection modeling machine. By using this principle, the pump only works during cylinder protrudes. The kinetic energy that system holds during this process will be absorbed by accumulator and be reused as the power for cylinder withdrawal. When cylinder draws back, the movement is controlled by proportional throttle valve. The flow through the proportional throttle valve is corrected according to the new flow control principle to eliminate the influence of the pressure in accumulator and the load. Compared with the system that the velocity in both directions is controlled by speed variable pump, the energy consumption caused by braking of electric motor during cylinder withdrawal can be eliminated completely. The research results prove that the new circuit principle can meet the requirement of plastic injection molding machine to its dynamic and static performance.