Patent ID: 8087911

Claim:
A pump of an electronically controlled brake system comprising: a bore formed in a modulator block and connected with a suction port and a discharge port; a piston installed in the bore in a reciprocating movable manner and defining an inlet path therein; an inlet valve to open or close an exit-side end of the inlet path according to a position of the piston; and an outlet valve provided at one side of the bore, operations of the inlet and outlet valves being contrary to each other, wherein the outlet valve comprises: a valve seat; a sleeve to surround the valve seat; an outlet ball interposed between the sleeve and the valve seat and used to open or close a path defined in the valve seat; and a valve cap provided at one side of the sleeve to isolate an interior from an exterior of the bore, wherein a damping region is formed between the sleeve and the valve cap to reduce pulsation of fluid, and wherein at least one groove is formed in an inner circumferential surface of the valve cap, said at least one groove arranged to guide fluid from the path to the damping region.