| 摘要 |
PURPOSE:To mold thin molded products stably with a high accuracy by a method wherein the timing of starting mold re-clamping is controlled by a time while a mold clamping force upon the mold re-clamping is controlled so as to be increased gradually. CONSTITUTION:When the finish of increasing a mold clamping pressure is detected by a pressure switch 41, a mold re-clamping timing setting timer, different from an injection starting delaying timer, is put ON by the signal of the pressure switch 41 and only a solenoid valve 40 is exited by the time-out of the timer. As a result, only the amount of the delivered oil of a small- capacity pump 28 is employed for the mold re-clamping and a large-capacity pump 30 is not employed, therefore, the flow amount of the oil is smaller compared with a conventional embodiment. Accordingly, the pressure increasing curve of the mold re-clamping is gentle and a mold is closed so as to cope with the internal shrinkage of molten resin in a cavity, therefore, good molded products may be obtained and this method is especially effective for the molded products having a thickness less than 2mm. |
