摘要 |
In a hybrid injection system of a die casting machine, the occurrence of a large electric power loss can be prevented by avoiding a large current at a pressure-holding step and the size of a motor is reduced. In an injection system comprising an injection cylinder (16) housing an injection piston (15) for injecting molten metal to a mold and an electric booster (8) of hydraulic cylinder type, a head chamber (8H) to the electric booster communicates fluidly with a head chamber (16H) of the injection cylinder, causing a booster piston rod (5) to be housed in the electric booster (8) to move linearly and thus pressing under pressure to move the injection piston to perform injection molding. Because a stop valve (25) is provided in a pipe that causes the head chamber (16H) of the injection cylinder to communicate with a rod chamber (8R) of the booster (8), it is possible for the pressure of the hydraulic oil to act on a head area of the electric booster at a pressure-increasing step for increasing pressure of the molten metal, and for pressure of the hydraulic oil to act on a rod area of the electric booster at a pressure-holding step for holding pressure of the molten metal.
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