Disc wheel for passenger car

A disc wheel for a passenger car comprising a rim and a disc, said disc having a hub mounting portion extending in a direction perpendicular to an axis thereof, a hat middle portion continuously extending from said hub mounting portion toward an outer side in a radial direction and an outer side in an axial direction, a hat top portion continuously extending from said hat middle portion, a ventilation hole portion continuously extending from said hat top portion toward an inner peripheral surface of the rim and a flange portion continuously extending from said ventilation hole portion and fitted to the inner peripheral surface of the rim, and said rim inner peripheral surface and the disc flange being welded,

• wherein a thickness of said disc wheel is varied in a diametrical direction at at least one of said hub mounting portion, the hat middle portion, the hat top portion, the ventilation hole portion and the flange portion,
• wherein the thickness of said hub mounting portion is equal to or smaller than an original thickness of the raw material, the thicknesses of said hat middle portion and the hat top portion are smaller than that of the hub mounting portion, the thickness of said ventilation hole portion is equal to the original thickness of the raw material, and the thickness of said flange portion is smaller than those of said hat middle portion and the hat top portion.

A disc wheel for a passenger car comprising a rim and a disc, said disc having a hub mounting portion extending in a direction perpendicular to an axis thereof, a hat middle portion continuously extending from said hub mounting portion toward an outer side in a radial direction and an outer side in an axial direction, a hat top portion continuously extending from said hat middle portion, a ventilation hole portion continuously extending from said hat top portion toward an inner peripheral surface of the rim and a flange portion continuously extending from said ventilation hole portion and fitted to an inner peripheral surface of the rim, and said rim inner peripheral surface and the disc flange being welded,

• wherein a thickness of said disc wheel is varied in a diametrical direction at at least one of said hub mounting portion, the hat middle portion, the hat top portion, the ventilation hole portion and the flange portion,
• wherein the thickness from said hub mounting portion via the hat middle portion to the hat top portion is substantially equal to the original thickness of the raw material, the thickness from said hat middle portion to the ventilation hole portion and the flange portion are smaller than the thickness of the hub mounting portion, and the inner periphery of said ventilation hole portion is thicker than the hub mounting portion by a burring process.