| 摘要 |
There are disclosed a method and an apparatus for forming disk wheel like formed parts, in a manner that the forming work is carried out by placing, in the vertical direction, the mold axis of a metal mold cavity, which corresponds to the axis of rotation of a disk wheel, thus to inject hot molten metal from the bottom in the mold axis direction, characterized in that the control mode of the injection speed comprises: a first phase to allow an injection speed when the hot molten metal has reached the inlet of the metal mold cavity to be low, a second phase to allow an injection speed from the time when the hot molten metal passes a disk wheel hub equivalent portion of the metal mold cavity until it passes the greater part of a disk wheel rim portion thereof via a disk wheel disk portion thereof to be, at the end portion of said rim equivalent portion, equal to a speed corresponding to a lower speed or less, which corresponds to a gas discharge ability of a degassing unit provided in association with the metal mold, and a third phase to close a discharge valve of the degassing unit after the hot molten metal has passed the greater part of the rim equivalent portion to continuously carry out injecting operation, thus allowing the hot molten metal to be completely filled up into the metal mold cavity. Thus, this permits gas within the metal mold cavity to be effectively discharged at any time without causing gas to be involved into hot molten metal, thus making it possible to easily provide nest-free, high quality formed parts. |
