| 摘要 |
PURPOSE:To complete mold clamping when parison exactly reaches its proper position by a method wherein the speed of a mold clamping hydraulic cylinder device is controlled by calculating the arrival time of the lower end of the parison to the lower end of a mold is calculated on the basis of the drooping speed of the parison, which is detected at the fixed position in the midway of the drooping course of the parison injected from a die. CONSTITUTION:Parison 12 is continuously lowered by being injected from a die part 10. When the tip of the parison 12 is detected with an upper photoelectric sensor 38, the measurement of time is started. In succession, when the tip of the parison 12 is detected with a lower photoelectric sensor 40, the measurement of time is completed. By inputting the measured times to the speed calculating section 44 of a controlling device 42, the drooping speed of the parison is calculated. By inputting the calculated result in a mold clamping speed setting section 46, the arrival time T of the parison 12 to the lower edge position of a cavity is calculated. Through the addition of minute time (alpha) to the time T for realizing proper pinching-in state, the mold clamping speed V is calculated so as to complete mold clamping after the time (T+alpha). By reading feed flow rate, which realizes said speed V, from a memory 45, the corresponding opening of a flow control valve 35 is set so as to output it to a valve driver 48. |
