Quan Long

(Institute for Mechatronics, Taiyuan University of Technology, Taiyuan 030024)

Lian Zisheng

(Mechanical Engineering Department, Taiyuan University of Technology, Taiyuan 030024)

Abstract: The research, for an innovative electro-hydraulic servo system that a differential cylinder is controlled closed loop with two speed variable pumps, specially used to control a clamping unit of plastic injection moulding machine, is carried out. On the base of summer pressure and chamber pressure controller, further a new idea that control the inlet and outlet of cylinder separately is put forward. With this principle the back pressure keeps a constant low value, that make the pressure of system always keeping adaptive with load automatically. The capability of each motor can be used sufficiently, the energy consumption of system and electric motors be reduced greatly, and the heat of pumps also be reduced without any influence of dynamic and static performance of system. The researching work is approved by simulation and test. The results have important significance for developing new type of plastic injection moulding machine with high efficiency and low energy consumption.

Key words: Electro-hydraulic servo control  Speed variable pump  Differential cylinder  Efficiency

CLC No: TH137

国家自然科学基金(50275102)和浙江大学流体传动与控制国家重点实验室开放基金(GZKF-2002004)资助项目. Received 20040303, received in revised form 20040918