Patent ID: 6837694

Claim:
A hydraulic pump unit for vehicle brake control system comprising: a pump housing; a cylinder received in a receiving hole formed in the pump housing, the cylinder having a bottom portion and being provided at the bottom portion with an outlet valve; a plunger received in the cylinder with a slidable contact, the plunger being driven by a cam and defining a pump chamber in cooperation with the cylinder; an inlet valve provided on the plunger; an inlet passage formed in the pump housing, an opening of the inlet passage being provided in the receiving hole; an outlet passage formed in the pump housing, an opening of the outlet passage being provided in the receiving hole; a plug member for closing an opening of the receiving hole, the plug member being fixed to the bottom portion of the cylinder; and an orifice passage formed on an orifice plate, the orifice plate being arranged between the bottom portion and the plug member.