Motor-driven power steering apparatus

• US 4,960,178 A
• Filed: 09/22/1988
• Issued: 10/02/1990
• Est. Priority Date: 09/30/1987
• Status: Expired due to Fees

• Current Assignee: Hitachi Automotive Engineering Company Limited (Hitachi, Ltd.), Hitachi, Ltd.
• Original Assignee: Hitachi Automotive Engineering Company Limited (Hitachi, Ltd.), Hitachi, Ltd.
• Inventors: Takahashi, Tadashi, Okuyama, Toshiaki, Tahara, Kazuo, Marumoto, Katsuji, Hombu, Mitsuyuki, Abukawa, Toshimi, Yamamura, Hirohisa, Omae, Tsutomu, Koterazawa, Toshiyuki, Ishikura, Hisatugu, Tatsuzaki, Toru, Takamatsu, Shuichi
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): Johnson, Brian L.
• Application Number:
  US07/247,509
• Time in Patent Office: 740 Days
• Field of Search: 180/79.1, 180/142, 307/16, 320/15, 320/16, 322/90
• US Class Current: 180/443
• CPC Class Codes: B62D 5/04 electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
• CPC Class Codes: B62D 5/0457 characterised by control features of the drive means as such

Abstract

A generator generates two voltage outputs which have different voltage levels. One voltage output from the generator is used for operating a power steering apparatus. Another voltage output from the generator is used for charging a battery which supplies current to other loads.

Claims

1. A motor driven power steering apparatus for a vehicle which depends on a DC power source as an energy source for electrical devices mounted on the vehicle having a steering shaft, comprising:

a generator driven by an engine of the vehicle, said generator having first winding means for generating a first DC voltage having a first voltage level and second winding means for generating a second DC voltage having a second voltage level which is higher than said first voltage level;

first and second voltage suppliers connected to said first and second winding means, respectively; and

actuator means for generating an auxiliary steering force for the vehicle, including a motor for providing an auxiliary steering force, torque detector means for detecting a torque applied to the steering shaft of the vehicle and current control means connected between said second voltage supplier and said motor for controlling a current supplied to said motor to control said auxiliary steering force in response to said torque detector means, said first voltage supplier being connected to supply voltage to other electrical devices of the vehicle.

2. An apparatus according to claim 1, wherein said generator includes a field winding connected to receive an excitation voltage from said first winding means and to supply flux to both said first and second winding means.

3. An apparatus according to claim 1, wherein said first and second voltage suppliers are batteries.

4. An apparatus according to claim 1, wherein said first voltage supplier is a battery and said second voltage supplier is a condenser.