US5485067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric power steering apparatus
Assignee: Koyo Seiko Co Ltd
•
Filing: 1994-07-01
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Granted: 1996-01-16
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Expires: 2014-07-01
Abstract
Abstract An electric power steering apparatus which is provided with a CPU for outputting a drive control signal of an electric motor for assisting the steering force on the basis of the detected steering torque, and a drive inhibition circuit for outputting a signal to stop the operation of the electric motor when the direction of the electric motor operation and the direction of the detected steering torque are opposite to each other, the output of the drive inhibition circuit is inputted to the CPU, which monitors the normal or abnormal condition of the drive inhibition circuit. While the abnormal condition of the CPU continues for a predetermined time period, the drive stop condition of the electric motor is kept. When the detected torque is not smaller than the predetermined value, the drive of the electric motor in the direction opposite to that of the detected torque is inhibited.
Inventors
- 👤 Mitsuhiko Nishimoto
- 👤 Hirofumi Matsuoka
- 👤 Hiroki Amako
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:39
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/04; B62D5/0457; B62D5/0481; B62D5/0493
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
163 words
An electric power steering apparatus including an electric motor which provides an assisting steering force, comprising: a processor to which a detected signal of steering torque and direction is inputted and which outputs a drive control signal of magnitude and direction for the electric motor on the basis of the detected steering torque; drive inhibition circuit means responsive to the detected steering torque direction which outputs a signal to stop the operation of the electric motor when the driving direction of the electric motor as directed by said processor and the direction of the detected steering torque are opposite to each other; and said processor including comparing means responsive to said drive inhibition circuit output signal and the steering torque direction signal for detecting when said drive inhibition circuit output signal is correctly stopping operation of the electric motor in the condition when the driving direction of the electric motor and the direction of the detected steering torque are opposite to each other.
Claim 2
Dependent Claim
163 words
An electric power steering apparatus including an electric motor which provides an assisting steering force, comprising: a processor to which a detected signal of steering torque and direction is inputted and which outputs a drive control signal of magnitude and direction for the electric motor on the basis of the detected steering torque; drive inhibition circuit means responsive to the detected steering torque direction which outputs a signal to stop the operation of the electric motor when the driving direction of the electric motor as directed by said processor and the direction of the detected steering torque are opposite to each other; and said processor including comparing means responsive to said drive inhibition circuit output signal and the steering torque direction signal for detecting when said drive inhibition circuit output signal is correctly stopping operation of the electric motor in the condition when the driving direction of the electric motor and the direction of the detected steering torque are opposite to each other.
Claim 3
Dependent Claim
96 words
An electric power steering apparatus as set forth in claim 1, wherein said comparing means comprises: a logic circuit for comparing the agreement between the drive control signal from said processor for representing the driving direction of the electric motor and the output signal from said drive inhibition circuit; and means for maintaining the drive stop of the electric motor while the condition of the driving direction of the electric motor and the direction of the detected steering torque are opposite to each other as detected by said logic circuit continues for a predetermined time period.
Claim 4
Dependent Claim
62 words
An electric power steering apparatus as set forth in claim 1, further comprising: means for comparing the detected steering torque and direction with a predetermined value, and said drive inhibiting circuit means inhibiting the drive of the electric motor in the direction opposite to that of the detected steering torque when the detected steering torque is not smaller than said predetermined value.
Claim 5
Dependent Claim
81 words
An electric power steering apparatus as set forth in claim 1, further comprising: first circuit means for calculating a differential signal of a signal corresponding to the detected steering torque; second circuit means for calculating the sum of the differential signal calculated by said first circuit means and the signal corresponding to the detected steering torque; and said drive inhibition circuit means inhibiting the drive of the electric motor on the basis of the sum calculated by said second circuit means.
Claim 6
Dependent Claim
55 words
An electric power steering apparatus as set forth in claim 4, further comprising: differentiating means for calculating a differential signal of the detected steering torque; said processor driving the electric motor on the basis of the sum of the current value determined according to the detected steering torque and the output of said differentiating means.
Claim 7
Dependent Claim
27 words
An electric power steering apparatus as set forth in claim 5, wherein a gain of said first circuit is greater than a gain of said differentiating means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-15 | 1999-07-17 | 2000-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-15 | 2003-07-17 | 2004-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-15 | 2007-07-17 | 2008-01-16 | $7700.00 | Window Closed / Lapsed |