| 摘要 |
PURPOSE:To prevent the generation of overshoot or undershoot without replacing an injection servo motor, by a method wherein an output torque limit value is increased or decreased from the torque limit value of the previous stage to that of this stage so that the change value thereof gradually approaches zero at least in the vicinity of the finish of a change-over time width. CONSTITUTION:In change-over from the torque limit value of the previous stage to that of this stage, the output torque limit value of a servo motor 1 for driving a screw 2 in the axial direction thereof is successively increased or decreased from the torque limit value of the previous stage to that of this stage in a set change-over time width and controlled so that the change value of said output torque limit value gradually approaches zero in the vicinity of the finish of the chnage-over time width. As a result, the torque limit value is not changed suddenly at the change-over time of holding pressure and gradually changed over a predetermined change-over time width and, since the change value of the torque limit value is small in the vicinity of the finish of the change-over time width, the overshoot or undershoot of the holding pressure is reduced. |
