摘要 |
PROBLEM TO BE SOLVED: To provide a clamping device which can detect an abnormal clamping force beyond a specified range with high accuracy without arranging a dedicated strain detector.SOLUTION: A clamping device for injection molding machines includes a toggle mechanism 20 which causes a movable disk 10 to approach and separate from a fixed disk 11, a servomotor 51 driving the toggle mechanism 20 and a controller 55 which controls the operation of servomotor 51 and issues a warning on the basis of results of comparing a monitor torque value with a criterion torque value for the servomotor 51 in a holding step carried out after completion of clamping. The torque limit value Tis set to be a value beyond the rating torque value Tof the servomotor 51, and the practical torque value Tis an average value of a plurality of preceding shots. |