| 摘要 |
PURPOSE:To attain the miniaturization and weight reduction of an injection cylinder by providing pressure oil chambers for advancing and retracting purposes to the injection piston and also providing a pressure oil path leading the pressure oil chamber for advancing purpose to the cylindrical hollow of a rotary follow shaft to the rotary shaft. CONSTITUTION:By a drive motor 56, a rotary shaft 60 is held and turned by a bearing 72, and a rotary follow shaft 80 connected with a spline is held and turned by a bearing 104, through which resin is fluidized and sent under pressures by a screw 84. During the injection molding period, pressure oil is supplied from an oil supply hole 114 to the pressure oil portion 108 for advancing purpose to press the injection piston 90 and at the same time the pressure oil in the portion 18 enters through the pressure oil path 112 of the rotary shaft 60 into the cylindrical hollow 81 of the rotary follow shaft 80 to press the rotary follow shaft 80, whereby permitting injection to be performed with a great propulsion force entailed. The retracting of the injection piston 90 is made by supplying pressure oil to the pressure oil chamber 115 for retracting purpose. The diameter of the injection piston can thus be made smaller, the load of thrust bearing can be made smaller, and therefore, the size of the injection cylinder can be reduced. |
