US4735271A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor-driven power steering system for vehicles
Assignee: Honda Motor Co Ltd
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Filing: 1987-01-06
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Granted: 1988-04-05
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Expires: 2007-01-06
Abstract
Abstract A motor-driven power steering system for vehicles includes a control device which is responsive to output signals from a torque detector mechanism which detects a steering torque acting on an input shaft, for applying a driving signal to an electric motor to produce an assistive torque to be imposed on the output shaft. The power steering system further includes a device for detecting a freely returning state of a steering wheel to produce a motor damping signal and a motor damping device for damping the electric motor in response to the motor damping signal.
Inventors
- 👤 Yasuo Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:30
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/04; B62D5/0457; B62D5/046; B62D5/0466
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
107 words
A motor-driven power steering system for a vehicle, comprising: an input shaft operatively coupled to a steering wheel; an output shaft operatively coupled to a dirigible wheel; an electric motor for applying an assistive torque to said output shaft; torque detecting means for detecting a steering torque imposed on said input shaft; control means responsive to output signals from said torque detecting means for applying a driving signal to said electric motor; freely returning state detecting means for detecting a freely returning state of the steering wheel to generate a motor damping signal; and damping means responsive to the motor damping signal for damping said electric motor.
Claim 2
Dependent Claim
107 words
A motor-driven power steering system for a vehicle, comprising: an input shaft operatively coupled to a steering wheel; an output shaft operatively coupled to a dirigible wheel; an electric motor for applying an assistive torque to said output shaft; torque detecting means for detecting a steering torque imposed on said input shaft; control means responsive to output signals from said torque detecting means for applying a driving signal to said electric motor; freely returning state detecting means for detecting a freely returning state of the steering wheel to generate a motor damping signal; and damping means responsive to the motor damping signal for damping said electric motor.
Claim 3
Dependent Claim
71 words
A motor-driven power steering system according to claim 1, wherein said freely returning state detecting means comprises said torque detecting means and a rotational speed detecting means for detecting a rotational speed of said steering wheel, and wherein said freely returning state detecting means generates said motor damping signal when said steering torque is smaller than a presecribed steering torque and said steering speed is larger than a prescribed steering speed.
Claim 4
Dependent Claim
65 words
A motor-driven power steering syatem according to claim 2, wherein said freely returning state detecting means further includes a neutral position detecting means for detecting the condition that a said steering wheel is in the vicinity of a neutral position, and wherein said freely returning state detecting means generates said motor damping signal when said steering wheel passes in the vicinity of the neutral position.
Claim 5
Dependent Claim
27 words
A motor-driven power steering system according to claim 3, wherein said neutral position detecting means comprises a means for detecting a steering angle of said steering wheel.
Claim 6
Dependent Claim
32 words
A motor-driven power steering system according to claim 3, wherein said neutral position detecting means comprises a means for detecting the condition that a steering aceleration of said steering wheel is negative.
Claim 7
Dependent Claim
29 words
A motor-driven power steering system according to claim 2, wherein said prescribed steering torque has a relatively small value and said prescribed steering speed has a relatively large value.
Claim 8
Dependent Claim
75 words
A motor-driven power steering system according to claim 1, wherein said freely returning state detecting means comprises said torque detecting means and a rotational speed detecting means for detecting a rotational speed of said electric motor, and wherein said freely returning state detecting means generates said motor damping signal when said steering torque is smaller than a prescribed steering torque and said rotational speed of said electric motor is larger than a prescribed motor speed.
Claim 9
Dependent Claim
64 words
A motor-driven power steering system according to claim 7, wherein said freely returning state detecting means further includes a neutral postion detecting means for detecting the condition that said steering wheel is in the vicinity of a neutral position, and wherein said freely returning state detecting means generates said motor damping signal when said steering wheel passes in the vicinity of the neutral position.
Claim 10
Dependent Claim
27 words
A motor-driven power steering system according to claim 8, wherein said neutral position detecting means comprises a means for detecting a steering angle of said steering wheel.
Claim 11
Dependent Claim
32 words
A motor-driven power steering system according to claim 8, wherein said neutral position detecting means comprises a means for detecting the condition that a rotational acceleration of said electric motor is negative.
Claim 12
Dependent Claim
29 words
A motor-driven power steering system according to claim 7, wherein said prescribed steering torque has a relatively small value and said prescribed motor speed has a relatively large value.
References Cited (Backward Citations)
US4651840A
Cited
US4657103A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |