Patent ID: 7651176

Claim:
A brake-by-wire brake system comprising: a tandem-type master cylinder including two fluid pressure chambers for generating a brake fluid pressure in response to a braking operation by a driver; a tandem-type slave cylinder including: a cylinder body having a rear fluid pressure chamber and a front fluid pressure chamber formed therein for electrically generating brake fluid pressure corresponding to the braking operation, a rear piston and a front piston slidably fitted in the rear of the rear fluid pressure chamber and the front fluid pressure chamber, respectively, and a regulator disposed in the cylinder body, the regulator operatively attached to and operatively interconnecting the front and rear pistons, wherein the slave cylinder generates the brake fluid pressure in the rear fluid pressure chamber and the front fluid pressure chamber when the rear piston is advanced by an actuator; wherein a wheel cylinder of a first stream is connected to one of the fluid pressure chambers of the master cylinder via the rear fluid pressure chamber of the slave cylinder; wherein a wheel cylinder of a second stream is connected to the other fluid pressure chamber of the master cylinder via the front fluid pressure chamber of the slave cylinder; and wherein the regulator is configured and arranged to limit a maximum distance between the rear piston and the front piston of the slave cylinder, and thereby to limit a maximum volume of a pressurized one of the first and second pressure chambers in the event of a pressure loss in the other pressure chamber, and wherein the wheel cylinders of the first and second streams are operated by the brake fluid pressure generated by the slave cylinder in a normal operation of the system, and the wheel cylinders of the first and second streams are operated by the brake fluid pressure generated by the master cylinder in an abnormal operation of the system.