| 摘要 |
PURPOSE:To prevent a molded product from warping by varying the timing for raising a mold on the fixed side and a mold on the movable side, and the timing for lowering them, and also the lowering speed when the molding temperature control for raising the molding temperature temporarily during the molding cycle is carried out. CONSTITUTION:Maximum introducing power is applied for raising the temperature in a short period of time at the time of heating, and the attained temperature is controlled by the time of applying the introducing power. When the power is applied to a molded product which is likely to warp from a fixed side to a movable side on the assumption that the heat volumes of both molds are equal, the application of the power to a movable side mold plate is delayed by (r) seconds than the application of the power to a fixed side mold plate. Said process is also applied in the case the heat volume on the fixed side mold plate is larger than that of the movable side mold plate. As for warping, in case the heat volume is contrary to the above-mentioned situation, the contrary side is delayed. A control device to realize said control method sends timing signals for each process from a molding machine 1 to a sequence control unit 2. The sequence control unit 2 switches the direction of a valve V1 and changes the divergence of valves V2 and V3 according to the procedures of valves V1, V2 and V3 and a setting instrument 5 to set the opening degrees of valves V2 and V3 and also by the procedures fixed by timers 3 and 4. |
