Hitachi Automotive Systems, Ltd.

Daichi Nomura

Toshiyuki Ajima

Takuya Usui

Kazuhiko Nakano

Hidefumi Iwaki

Hiroshi Shigeta

Hirohumi Watanabe

An electric motor () is controlled according to the stroke of an input rod () moved in response to an operation of a brake pedal. The rotation of the electric motor is transmitted through a belt transmission mechanism () to a ball-screw mechanism () to propel a primary piston (), thereby generating a brake hydraulic pressure in a master cylinder (). The belt transmission mechanism has pulleys (A,B), one of which is secured to an output shaft of the electric motor. The output shaft and a nut member () of the ball-screw mechanism are held by bearings (A,B andC) secured to a rear housing (B) which is a single member. Thus, before an electric motor-driven booster () is assembled, the belt transmission mechanism can be subassembled to the rear housing. Therefore, a belt () can be adjusted for tension in the state of a subassembly.

Electric motor-driven booster

An electric booster includes a housing having one end including a coupling surface where the housing is coupled to a master cylinder, and the other end including an attachment surface where the housing is attached to a vehicle. A controller includes a flat plate-like control board, and the control board is disposed so as to be positioned between a first plane including the attachment surface of the housing where the housing is attached to the vehicle, and a second plane including the coupling surface of the housing where the housing is coupled to the master cylinder.

Electric booster

Growing community of inventors

Kawasaki, Japan

Daichi Nomura