| 摘要 |
PURPOSE:To make it possible to change suitably to a dwell step, to obviate the longer application of the filling stage pressure, and to make an expensive pressure detector unrequired, by finding the degree of filling of a melted resin into a mold cavity based on the amount of the displacement of a poppet of a relief valve on a hydraulic circuit led to an injection ram. CONSTITUTION:A relief valve 20 is provided with a poppet 32, a spring 31 and a manual handle 30. A poppet displacement detector 21 for detecting the amount of the displacement of the poppet 32 is provided to pass through the manual handle 30. A change-over signal originating circuit comprises an amplifier 22 for amplifying the amount of electricity detected by the the poppet displacement detector 21, a comparator 23 compares a set value of a dwell change-over poppet displacement setting apparatus 24 with the actual displacement detected value of the poppet 32 from the amplifier 22, and when the detected value coincides with the set value, it outputs a signal to effect the change to the dwell step. |
