Hydraulic control system for an injection molding machine
AssigneeToshiba Kikai Kabushiki Kaisha
InventorsMasahiko Furuya, Hiroki Arakawa
Life of this patent
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Abstract
A hydraulic control system for an injection molding machine is provided with a pump driving induction motor capable of operating at an operating speed corresponding to a flow rate at which a hydraulic fluid is to be supplied to a desired one of hydraulic actuators for operating the functional components of the injection molding machine to supply the hydraulic fluid efficiently at a reduced power consumption. Since the operating speed of the induction motor is controlled according to the desired flow rate of the hydraulic fluid corresponding to the operating speed of the hydraulic actuator, the hydraulic fluid can efficiently be supplied to the hydraulic actuator and the useless power consumption can be avoided.
Claims8
A hydraulic control system for an injection molding machine, comprising:
- a plurality of hydraulic actuators assigned respectively for driving functional units included in the injection molding machine;
- a hydraulic circuit including solenoid valves for serving to direct the hydraulic fluid to the optional hydraulic actuators to drive the hydraulic actuators selectively;
- a controller that provides flow control signals for instructing flow rates corresponding to predetermined operating speeds at which the hydraulic actuators are driven according to respective stages of an injection molding cycle;
- a speed control valve, disposed in the hydraulic circuit at a position downstream of the hydraulic fluid to be supplied to the hydraulic actuators on the basis of the flow control signals;
- a motor controller using an inverter to control the pump driving motor for rotation at a desired rotational speed;
- and
- a pump speed setting means, connected between the controller and the motor controller, for determining a rotational speed instruction given to the motor controller on the basis of the flow control signals provided by the controller.
Dependencies are inferred from the claim text.