Light alloy wheel for vehicle and method and apparatus for producing same

A method for producing a light alloy wheel for a vehicle, said light alloy wheel comprising a disc portion comprising a hub portion and a design portion and a rim portion, said design portion having substantially as-die-cast spoke portions having at least partially taper angles of less than 5.0°, said method comprising using a casting apparatus comprising a die assembly comprising at least a stationary lower die and a movable upper die, a movable platen to which said upper die is fixed, and one cylinder mounted onto a frame of said apparatus for moving said movable platen;

• and driving said cylinder to slowly reduce the clamping force of said lower die and said upper die.

A method for producing a light alloy wheel for a vehicle, said light alloy wheel comprising a disc portion comprising a hub portion and a design portion and a rim portion, said design portion having substantially as-die-cast spoke portions having at least partially taper angles of less than 5.0°, said method comprising using a casting apparatus comprising a die assembly comprising at least a stationary lower die and a movable upper die, a movable platen to which said upper die is fixed, and a first cylinder and at least three synchronous second cylinders both mounted onto a frame of said apparatus for moving said movable platen;

• synchronously driving said second cylinders to elevate said movable platen in parallel from a position at which said lower die and said upper die are clamped to a position at which said wheel would not impinge on said lower die even if said movable platen were slanted;
• and then further elevating said movable platen by said first cylinder.

A method for producing a light alloy wheel for a vehicle, said light alloy wheel comprising a disc portion comprising a hub portion and a design portion and a rim portion, said design portion having substantially as-die-cast spoke portions having at least partially taper angles of less than 5.0°, said method comprising using a casting apparatus comprising a die assembly comprising at least a stationary lower die and a movable upper die, a movable platen to which said upper die is fixed, a first cylinder and at least three synchronous second cylinders mounted onto a frame of said apparatus for moving said movable platen;

• driving said first cylinder to slowly reduce the clamping force of said lower die and said upper die;
• synchronously driving said second cylinders to elevate said movable platen in parallel from a position at which said lower die and said upper die are clamped to a position at which said wheel would not impinge on said lower die even if said movable platen were slanted;
• and then further elevating said movable platen by said first cylinder.

An apparatus for producing a light alloy wheel for a vehicle, said light alloy wheel comprising a disc portion comprising a hub portion and a design portion and a rim portion, said design portion having substantially as-die-cast spoke portions having at least partially taper angles of less than 5.0°, said apparatus comprising a die assembly comprising at least a stationary lower die and a movable upper die, a movable platen to which said upper die is fixed, and a vertical movement mechanism of said movable platen mounted onto a frame of said casting apparatus;

• said vertical movement mechanism comprising (a) a first cylinder for moving said movable platen up and down, and (b) at least three second cylinders synchronously driven for elevating said movable platen in parallel from a position at which said lower die and said upper die are clamped to a position at which said wheel would not impinge on said lower die even if said movable platen were slanted;
• and said movable platen being elevated by said first cylinder above the upper limit position of said second cylinders.