To detect brake torque on the basis of liquid pressure by generating liquid pressure complying with a friction force.
When braking is applied while a disc rotor 10 rotates in the regular direction, a friction force is generated between a frictional engagement member and the rotor 10, and calipers 14 are rotated in the regular direction. In a hydraulic cylinder 51, accordingly, a piston 54 is advanced against the energizing force of a return spring 66 to cause a decrease in the capacity of a liquid pressure chamber 64, and thereby the liquid pressure is generated. Because the liquid pressure has a magnitude in compliance with the braking force between the frictional engagement member and the rotor 10, the braking force can be determined on the basis of the liquid pressure, and the brake torque can be detected by multiplying the braking force by the radius of the position where the frictional engagement member is mounted on the rotor 10.
MIZUTANI KYOJI
YAMAMOTO TAKAYUKI
