Patent ID: 10005441

Abstract:
An electric motor is controlled according to the back and forth movement of an input rod, which is caused by brake pedal operation; a primary piston is propelled to generate hydraulic brake pressure in a master cylinder; and the hydraulic brake pressure is fed back to the input rod through an input piston. The input piston is resiliently held by springs with respect to the primary piston. A jump-in clearance is created between the input piston and the input rod by a rearward spring. At the initial stage of braking, hydraulic brake pressure is not transmitted to the input rod due to the jump-in clearance, which provides jump-in characteristics. The jump-in clearance can be set, regardless of the amount of a relative displacement between the primary piston and the input piston, so that the range of adjustment for regenerative braking can be set larger than the jump-in clearance.