Patent ID: 7427114

Claim:
A brake fluid pressure control unit for a vehicle, the brake fluid pressure control unit comprising: a base block of aluminum material, formed with a cylinder bore extending axially from a bottom end to an open end, the base block including a fixing portion to fix a cover member to the base block; a piston received slidably in the cylinder bore and shaped to divide the inside of the cylinder bore into a fluid chamber and an atmospheric chamber; a bias member disposed between the piston and the cover member, and arranged to urge the piston toward the bottom end of the cylinder bore; and the cover member fixed to the base block to cover the open end of the cylinder bore, and made of aluminum material, wherein the cover member includes a flange, the flange including a tapered surface projecting outward in a direction toward the bottom end such that a diameter of an outer portion of the tapered surface toward the bottom end is greater than a diameter of an inner portion of the tapered surface, wherein a thickness of the flange at the inner portion of the tapered surface, wherein the fixing portion of the base block and the tapered surface of the flange are staked, wherein the base block includes a substantially flat annular shoulder surface facing away from the bottom end of the cylinder bore; and wherein the cover member includes a substantially flat annular cover end surface facing toward the bottom end of the cylinder bore, the annular cover end surface including a substantially flat outer region abutting on the annular shoulder surface of the base block and a substantially flat inner region projecting from the outer region radially inward beyond the annular shoulder surface into the cylinder bore and facing axially toward the piston.