| 摘要 |
PURPOSE:To detect generation of a defective molding during operation and to improve workability by measuring the time since a melt is injected at a high speed into a metallic mold until a gas vent valve is automatically closed and comparing the same with the preset control time. CONSTITUTION:When a molten metal is supplied into a die cavity 4 and is filled therein, a gas vent valve 13 is closed as its valve 15 contacts tightly a valve seat 14a. A detaining bar 19 moves to actuate a sensor 20, the signal from which is inputted as the closing time of the valve 13 to a measuring device 29. The device 29 measures a measuring time Tm from the signal for starting the high speed injection and the closing signal of the valve 13. The time Tm is compared with the control time Ts which is preset by a control time setter 30 in a comparator 31 and if the former Tm is within the latter control time Ts, the absence of a defective molding is judged and an alarm device 32 is not operated. |
