| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection-molding machine capable of controlling the fluctuations of a mold clamping force during automatic operation and thereby stabilizing the mold clamping force, in the injection-molding machine using a toggle-type mold clamping device driven by a servo motor. SOLUTION: The peak current value of the mold clamping servo motor which drives the toggle-type mold clamping device, is proportional to the clamping force. The steps during automatic operation are as follows: the peak current value Pact per number of set molding cycles S is sought (S9 to S13); the difference between this peak current value Pact and a peak current value Pave stored as a reference is sought (S14); the variation level Fdiff of the clamping force and the adjustment level Tadj of a rear platen are sought based on the difference (S15 and S16); the clamping force is controlled so as to reach the set value by moving the rear platen based on the adjustment level Tadj (S20 to S25); operating safety is ensured by performing an abnormality treatment when the adjustment level Tadj of the rear platen and its integrated value Tu exceed the preset values (S17 to S19, S26 and S27); and the fluctuations of the clamping force are controlled even when the mold temperature changes and the mold thickness varies and consequently, the clamping force is stabilized. A special sensor is not necessary. COPYRIGHT: (C)2004,JPO
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