Hydraulic press closure speed control system - has sensor to measure speed and position of moving platen and value is compared with set figure before varying proportional control valve

摘要

A hydraulic circuit for controlling the closure speed of a press with a fixed and moving platen is described. The circuit has a pump with variable output connected to the hydraulic cylinder by an oil oil line passing through a magnetic directional control valve. The by-pass line around the directional control valve has a magnetic proportional flow control valve. A sensor determines the position or speed of the moving tool half which can be adjusted by a speed control unit. The sensor reading is compared with a set speed and the opening of the proportional control valve is adjusted to bring the speed to the set figure. USE/ADVANTAGE - The control system allows press closure speed to be varied at slow speeds without considering oil leakage and moulding pressure effect on the pressure cylinder side.