| 摘要 |
PURPOSE: A low-pressure casting apparatus for manufacturing car wheels is provided to reduce a failure rate by preventing excessive external pressure transmitted during cooling of molten metal. CONSTITUTION: A low-pressure casting apparatus for manufacturing car wheels comprises a low-pressure casting machine(10) and a cylinder driving part(17). The low-pressure casting machine comprises a plurality of cylinders(13,14,15,16) that press upper and lower molds to complete a mold(M) and inject molten metal into the cavity of the mold. A controller of the cylinder driving part controls voltage applied to a motor to stop the motor when the pressure sensed by a pressure sensor(175) is a first set value or greater, thereby maintaining hydraulic pressure supplied from a hydraulic supply pump to the cylinders. If the cylinder pressure is lowered to a second set value or less when discharging a wheel product from the mold, reference voltage is applied again and the controller activates the motor.
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