| 摘要 |
PURPOSE:To prevent the material in an injection nozzle from leaking and dropping due to the remaining pressure when the injection nozzle is moved away from the mold after the injection, by returning an injection plunger to its intermediate position immediately after the material is injected by moving the injection plunger forward, and keeping the injection plunger in said position for a prescribed period. CONSTITUTION:When a main body 1 is lowered to its prescribed position and the tip of an injection nozzle 6 is set to a sprue of a mold 3, a change-over valve 5 is changed to the injection side, and an injection plunger 7 is moved forward by an injection cylinder 8. Thus, the material in an injection chamber 4 is injected from the injection nozzle 6 into the cavity of the mold 3. When the injection plunger 7 reaches the forward end, a limit switch 6L is pushed and then the injection plunger 7 is immediately started to be withdrawn. When the injection plunger 7 is returned to the intermediate positin, a limit switch 7L is pushed, the withdrawing of the injection plunger 7 is stopped to allow it to remain in its intermediate position for a while so that the pressure of the material in the injection nozzle 6 may be allowed to decrease, thereafter the change-over valve 5 is changed to the filling side and the main body 1 is lifted up. |
