Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Masato Sakai

Shigeki Saito

Hiroshi Kimura

Toshiaki Okuyama

Kazuo Tahara

Toshimi Abukawa

Mitsuyuki Hombu

Tsutomu Ohmae

Seizi Yamashita

Hisatugu Ishikura

Toshiyuki Koterazawa

Shuichi Takamatsu

Toru Tatsuzaki

Hiroshisa Yamamura

Katsuji Murumoto

An electric power steering control system includes an electric motor for producing an assisting torque for the vehicle steering system through a reduction gear, a steering torque sensor fitted on the steering shaft, a controller for controlling the input to the motor in accordance with the torque sensor output, a battery for supplying power to the controller, and a voltage step-up circuit connected to the battery for driving the motor at a voltage higher than the battery voltage. The controller drives the motor at a high voltage.

Electric power steering control system

An electric power steering apparatus comprises a steering shaft 34, a detector 27 for detecting an operation of the power steering apparatus, an electric motor 3 driven in response to an output of the detector 27 for generating an assisting force for a steering operation, and a reduction gear 1 including an input shaft 2 driven by the electric motor 3, an output shaft 13 connected to the steering shaft 34, and a planetary gear mechanism 36 for reducing the rotational speed of the input shaft 2 and transmitting the reduced rotational speed to the output shaft 13. The planetary gear mechanism 36 includes a sun gear 6 rotatable with the input shaft 2, a ring gear 8, planet gears 7 connected to the output shaft 13 and adapted to transmit revolving motion thereof around the sun gear 6 to the output shaft 13, and a gear case 18 for accommodating the sun gear 6, the ring gear 8, and the planet gear 7. As electromagnetic clutch 35 is accommodated in the gear case 18 and is switched over in response to the output of the detector 27 between a first position in which it locks the ring gear 8 unrotatably and a second position in which it releases the ring gear 8 to allow it to be rotatable with respect to the output shaft 13.

Electric power steering apparatus

Growing community of inventors

Katsuta, Japan

Masato Sakai