| 摘要 |
PURPOSE:To realize mold opening speed at ultra-low speed stably, and to mold a thin molded form having a small draft angle by installing a cylinder with a rod being interlocked in the same direction as a prefill valve and closing the communication of the prefill valve and a mold-clamping cylinder oil chamber at the time of mold opening operation to the rear end of the prefill valve and connecting a duct for pushing the cylinder with the rod to a pump for generating oil pressure through a direction changeover valve. CONSTITUTION:When the signal of an ultra-low speed start position is introduced, the side (a) of a direction changeover valve 33 is excited, pressure oil in a pump 30 is admitted into a single acting cylinder 32 through ducts 34-35, and a rod 31 is pushed out and a prefill valve 13 is held to 'close'. Oil in a mold-clamping ram piston side chamber 20 is passed through a through-path 17 formed to the prefill valve 13, and introduced into a prefill-valve close-side chamber 22, and one of the oil escapes to an oil tank 15 from a duct 23 together with oil in a boost cylinder 18 through a path 16, and the other is passed through a communicating duct 38, and escapes to the oil tank 15 from the direction changeover valve 33 through a duct 39. |
