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US5201818A Expired / Lapsed US ⏱️ 0.0 years remaining

Power steering apparatus

Assignee: Koyo Seiko Co Ltd
•
Filing: 1991-04-16
•
Granted: 1993-04-13
•
Expires: 2011-04-16
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Abstract

Abstract The power steering apparatus for assisting the return of a steering wheel by the rotating force of a motor for assisting steering force wherein noting the fact that the steering torque when the steering wheel is being returned is within the dead zone, whether the steering wheel is being returned is judged on the basis of the steering torque detected by a torque sensor and the terminal voltage of the motor, and the direction and magnitude of a driving current for the motor when the steering wheel is being returned are determined corresponding to the vehicle speed. Accordingly, the steering wheel is returned to the neutral position without using a steering angle sensor.

Inventors

  • 👤 Mitsuhiko Nishimoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 14:49
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/04; B62D5/0457; B62D5/046; B62D5/0466

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 207 words
A power steering apparatus which comprises: a detecting means for detecting the speed of a vehicle; a torque sensor for detecting a steering torque exerted onto a steering wheel; driving current generating means, responsive to the torque sensor, for generating a driving current corresponding to the steering torque detected by said torque sensor; a motor for assisting steering force, driven by the driving current; wherein the driving current generating means comprises: a means for detecting the terminal voltage of said motor; a steering wheel return detecting means for detecting whether the steering wheel is being returned to the neutral position on the basis of the detected result of said terminal voltage detecting means and of said torque sensor; a returning current calculating means, responsive to the vehicle speed detecting means, for calculating a current to drive said motor to assist the return of the steering wheel on the basis of the detected result of said vehicle speed detecting means when said steering wheel return detecting means detects that the steering wheel is being returned; and a means for driving said motor by the driving current calculated by said returning current calculating means when said steering wheel return detecting means detects that the steering wheel is being returned.
Claim 2
Dependent Claim 207 words
A power steering apparatus which comprises: a detecting means for detecting the speed of a vehicle; a torque sensor for detecting a steering torque exerted onto a steering wheel; driving current generating means, responsive to the torque sensor, for generating a driving current corresponding to the steering torque detected by said torque sensor; a motor for assisting steering force, driven by the driving current; wherein the driving current generating means comprises: a means for detecting the terminal voltage of said motor; a steering wheel return detecting means for detecting whether the steering wheel is being returned to the neutral position on the basis of the detected result of said terminal voltage detecting means and of said torque sensor; a returning current calculating means, responsive to the vehicle speed detecting means, for calculating a current to drive said motor to assist the return of the steering wheel on the basis of the detected result of said vehicle speed detecting means when said steering wheel return detecting means detects that the steering wheel is being returned; and a means for driving said motor by the driving current calculated by said returning current calculating means when said steering wheel return detecting means detects that the steering wheel is being returned.
Claim 3
Dependent Claim 63 words
A power steering apparatus as set forth in claim 1, wherein said steering wheel return detecting means detects that the steering wheel is being returned when the steering torque detected by said torque sensor is in the dead zone of a predetermined range during said steering wheel being turned, and the terminal voltage of said motor is not smaller than a predetermined value.
Claim 4
Dependent Claim 47 words
A power steering apparatus as set forth in claim 1, wherein said returning current calculating means calculates such a returning current that the returning force of the motor for the steering wheel increases as the vehicle speed becomes closer to a predetermined value of the low speed.

References Cited (Backward Citations)

US4800975A Cited
JPS61115771A Cited
GB2188891A Cited
JPS6490870A Cited
JPH01309876A Cited
US5027276A Cited
EP0350817A2 Cited
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JPH0285061A Cited
US5122958A Cited
US5050697A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-04-12 1996-10-12 1997-04-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-04-12 2000-10-12 2001-04-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-04-12 2004-10-12 2005-04-13 $7700.00 Window Closed / Lapsed

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