| 摘要 |
PURPOSE:To extend the service life of a machine and to improve the working environment by reducing the descending speed of a slide just before upper and lower metallic molds collide and next collididing both metallic molds at the bottom dead center. CONSTITUTION:A servo valve 29 is arranged in the control circuit to cylinders 10a, 10b for preventing an over load and also sensors are arranged at the crank shaft for press and end of an eccentric gear shaft. The slide 5a is descended toward bottom dead center under descending condition at few mm from the position of top dead center of the slide 5a. Next, just before the upper and lower metallic molds M1, M1' collide, the fluid supplying quantity in the cylinders 10a, 10b for preventing over load is controlled from the sensor through control signal, to reduce the descending speed of the plunger 7 under descending. By this method, the impact force of the collision of the metallic molds M1, M1' at the bottom dead center is relaxed, and by the reduction of impact force, the service life of the machine is extended. Further, by the reduction of the impact sound, the working environment is improved.
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