To increase the amount of regenerative braking during regenerative cooperative braking and to obtain a jump-in characteristic in an electric booster device. An electric motor (40) is controlled in accordance with the backward/forward movement of an input rod (43) caused by a brake pedal, a primary piston (10) is driven, thereby generating brake fluid pressure in a master cylinder (2), and the brake fluid pressure is fed back to the input rod (34) via an input piston (32). The input piston (32) is elastically held with respect to the primary piston (10) by means of springs (37, 38), and a jump-in clearance (JC) is provided between the input piston (32) and the input rod (34) by means of a return spring (80). When braking begins, as a result of the jump-in clearance (JC) the brake liquid pressure is not transmitted to the input rod (34), and thus a jump-in characteristic is obtained. The jump-in clearance (JC) can be set irrespective of the relative amount of displacement of the primary piston (10) and the input piston (32), so the range of adjustment for regenerative braking can be set larger than the jump-in clearance (JC).
Electric booster device
2015-11-18
Patent
Electronic Resource
English
IPC: | B60T Bremsanlagen für Fahrzeuge oder Teile davon , VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF |