| 摘要 |
PROBLEM TO BE SOLVED: To provide a pressure control unit of an injection molding machine, which is equipped with a pressure estimator capable of acquiring a highly precise pressure estimate without the need for the grasp of an accurate physical constant, and a pressure control method for the injection molding machine. SOLUTION: This pressure control unit of the injection molding machine controls injection pressure which is generated when a molten material in a cylinder 1 is injected by advancing a movable member by a driving force of a servomotor 6. The pressure control unit is equipped with the pressure estimator for computing injection pressure from the torque and rotational speed of the servomotor 6 on the basis of an inverse model of a transfer function in which the torque of the servomotor 6 and a reaction force imposed on the movable member by the injection pressure are set as input and in which the rotational speed of the servomotor 6 is set as output. The pressure estimator 25 is equipped with a dead time element which indicates a time lag between the input and the output, and a lowpass filter for removing noises. The pressure estimator 25 performs the feed-back control of the injection pressure on the basis of a deviation of the pressure estimate, acquired by the pressure estimator 25, from a given injection pressure command value. COPYRIGHT: (C)2009,JPO&INPIT
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