| 摘要 |
PURPOSE: A separated type injection piston for controlling the stepless variable speed is provided to mechanically control the speed of an injection piston through all stroke intervals of the injection piston using a control pin so that a filling rate of molten metal corresponds to the change of volume inside a mold as 1:1 in the process that the molten metal is filled in the space of the mold. CONSTITUTION: In a separated type injection piston for controlling the stepless variable speed comprising an injection piston (40) for infusing molten metal into a mold, wherein a moving speed is determined by the fluid amount (hydraulic pressure) applied to the injection piston; a speed control pin (40) which is separately installed from the injection piston and has a shape for corresponding to the volume variation in the mold; and an orifice (12) having a larger diameter than the maximum diameter of the speed control pin so that the speed control pin can move inside the orifice, wherein a speed of the piston (40) is controlled as a flow rate applied to the injection piston is determined by a gap between the orifice (12) and the speed control pin (30) that is formed as the speed control pin is being slipped away from the orifice, the separated type injection piston is characterized in that a speed of the injection piston is controlled over the total stroke distance of the injection piston by having a length of the speed control pin corresponding to the total stroke distance of the injection piston.
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