Patent ID: 8733848

Claim:
A vehicular braking apparatus comprising: a shut-off valve that shuts off, as needed, a flow of a working liquid from a wheel cylinder to a master cylinder; a pressure increase-decrease control valve that increases and decreases a pressure in the wheel cylinder; a reservoir that receives and stores in a reservoir chamber the working liquid from the wheel cylinder when the pressure increase-decrease control valve is in a pressure decrease position and at a time when the working liquid in the master cylinder is pressurized; pressurizing supply means for sucking in and pressurizing the working liquid from the reservoir chamber and supplying the working liquid to the wheel cylinder via the pressure increase-decrease control valve when the pressure increase-decrease control valve is in a pressure increase position; and a communication control valve that controls communication between the master cylinder and the reservoir chamber, wherein the communication control valve includes a normally-closed on-off valve, and valve-opening means for opening the on-off valve by being driven by means of the suction pressure of the pressurizing supply means, wherein the normally-closed valve comprises a valve element and a valve element-urging member for urging the valve element to a closed position, and wherein the communication control valve maintains a closed condition at the time of nonbraking, and wherein the valve-opening means includes a reciprocally movable member disposed within the reservoir so as to be reciprocally movable in a direction of opening and closing of the on-off valve and that is driven in a direction of opening of the on-off valve by means of the suction pressure of the pressurizing supply means, the direction of opening of the on-off valve is a direction of reduction of a volume of the reservoir chamber, the reservoir has a housing, a reservoir piston disposed within the housing in a reciprocally movable manner and that defines the reservoir chamber in cooperation with the housing, and piston-urging means for urging the reservoir piston in the direction of reduction of the volume of the reservoir chamber, and the reservoir chamber communicates at all times with a suction side of the pressurizing supply means and communicates with the master cylinder via the communication control valve, and the reciprocally movable member includes a piston portion which is enclosed and supported by the reservoir piston so as to be telescopically displaceable in relation to the reservoir piston in a direction of reciprocal movement of the reservoir piston, and a stem portion united with the piston portion, the stem portion opens the on-off valve, and the piston portion and the stem portion, in cooperation with the reservoir piston, define a pressure chamber that communicates with the reservoir chamber at all times and functions as part of the reservoir chamber.