Patent US4953650A successfully refreshed from Google Patents.
US4953650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rear wheel steering control system
Assignee: Mazda Motor Corp
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Filing: 1989-03-13
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Granted: 1990-09-04
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Expires: 2009-03-13
Abstract
Abstract A rear wheel steering control system comprising a rear wheel steering mechanism, drive motor connected with said rear wheel steering mechanism for actuating the same, target setting means for setting a target steering angle of the rear wheels in accordance with a predetermined factor, motor control unit for controlling said drive motor so as to accomplish the target steering angle of the rear wheels, lock device for preventing the rear wheel steering mechanism from any steering movement when the target steering angle is substantially constant, release device for releasing the lock device to allow the steering movement of the rear wheel steering mechanism even when the target steering angle of the rear wheels is substantially constant under a predetermined condition, the control system is responsive in controlling the steering of the vehicle.
Inventors
- 👤 Hiroshi Ohmura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:30
CPC Classifications
B; B62; B62D; B62D7/00; B62D7/06; B62D7/14; B62D7/15; B62D7/159; B62D7/1581
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
135 words
A rear wheel steering control system comprising a rear wheel steering mechanism for steering rear wheels of a vehicle, drive motor means connected with said rear wheel steering mechanism for actuating the same, target setting means for setting a target steering angle of the rear wheels in accordance with a predetermined factor, motor control means for controlling said drive motor means so as to accomplish the target steering angle of the rear wheels, magnetic brake means for preventing the rear wheel steering mechanism from any steering movement when the target steering angle of the rear wheels is substantially constant, release means for releasing the magnetic brake means to allow the steering movement of the rear wheel steering mechanism under a predetermined condition even when the target steering angle of the rear wheels is substantially constant.
Claim 2
Dependent Claim
135 words
A rear wheel steering control system comprising a rear wheel steering mechanism for steering rear wheels of a vehicle, drive motor means connected with said rear wheel steering mechanism for actuating the same, target setting means for setting a target steering angle of the rear wheels in accordance with a predetermined factor, motor control means for controlling said drive motor means so as to accomplish the target steering angle of the rear wheels, magnetic brake means for preventing the rear wheel steering mechanism from any steering movement when the target steering angle of the rear wheels is substantially constant, release means for releasing the magnetic brake means to allow the steering movement of the rear wheel steering mechanism under a predetermined condition even when the target steering angle of the rear wheels is substantially constant.
Claim 3
Dependent Claim
51 words
A rear wheel steering control system in accordance with claim 1 wherein the rear wheel steering mechanism is provided with a relay rod for connecting right and left tie rods of the rear wheels and power transmitting means for transmitting an output of the drive motor means to the relay rod.
Claim 4
Dependent Claim
32 words
A rear wheel steering control system in accordance with claim 2 wherein the power transmitting means is provided with clutch means for controlling a transmission of the output of the drive motor.
Claim 5
Dependent Claim
31 words
A rear wheel steering control system in accordance with claim 3 wherein the power transmitting means is provided with speed reduction means for reducing a speed transmitted to the relay rod.
Claim 6
Dependent Claim
33 words
A rear wheel steering control system in accordance with claim 1 wherein the rear wheel steering mechanism is provided with a neutralizing means for returning and retaining the rear wheels at neutral positions.
Claim 7
Dependent Claim
31 words
A rear wheel steering control system in accordance with claim 5 wherein the neutralizing means is provided with a pair of spring seats and a spring disposed between the spring seats.
Claim 8
Dependent Claim
21 words
A rear wheel steering control system in accordance with claim 1 wherein the drive motor means comprises a DC servo motor.
Claim 9
Dependent Claim
72 words
A rear wheel steering control system in accordance with claim 1 wherein the rear wheel steering mechanism is further provided with steering angle detecting means for detecting a steering angle of a steering wheel, and speed detecting means for detecting a vehicle speed, the target setting means being adapted to set the target steering angle of the rear wheels based on the steering angle of the steering wheel and the vehicle speed.
Claim 10
Dependent Claim
61 words
A rear wheel steering control system in accordance with claim 8 wherein said steering angle detecting means is provided with a steering wheel steering angle sensor for detecting a rotation angle of a steering column connected with the steering wheel and a front wheel steering angle sensor for detecting a reduction means for reducing a speed transmitted to the relay rod.
Claim 11
Dependent Claim
35 words
A rear wheel steering control system in accordance with claim 8 wherein said speed detecting means is provided with a first vehicle speed sensor and a second speed sensor which detect the vehicle speed independently.
Claim 12
Dependent Claim
53 words
A rear wheel steering control system in accordance with claim 1 wherein the rear wheel steering mechanism is further provided with rotative position detecting means for detecting a rotative position of the drive motor means, said motor control means controlling the drive motor by utilizing a signal from the motor position detecting means.
Claim 13
Dependent Claim
51 words
A rear wheel steering control system in accordance with claim 11 wherein the rotative position detecting means is provided with an encoder for detecting the rotative position of the drive motor and a rear wheel steering angle sensor for detecting a displacement of a relay rod for steering the rear wheels.
Claim 14
Dependent Claim
41 words
A rear wheel steering control system in accordance with claim 1 wherein the release means revokes a steering lock operation of the magnetic brake means against the rear wheel steering mechanism when a vehicle speed is more than a predetermined value.
Claim 15
Dependent Claim
40 words
A rear wheel steering control system in accordance with claim 1 wherein the release means revokes a locking operation of the magnetic brake means against the rear wheel steering mechanism when the vehicle acceleration is more than a predetermined value.
Claim 16
Dependent Claim
40 words
A rear wheel steering control system in accordance with claim 1 wherein the release means revokes a locking operation of the magnetic brake means against the rear wheel steering mechanism when the vehicle deceleration is more than a predetermined value.
References Cited (Backward Citations)
JPS61175183A
Cited
US4645025A
Cited
JPS6225277A
Cited
US4770264A
Cited
JPS62160965A
Cited
WO1988004251A1
Cited
US4799566A
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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) | 1993-09-03 | 1994-03-05 | 1994-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-03 | 1998-03-05 | 1998-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-03 | 2002-03-05 | 2002-09-04 | $7700.00 | Window Closed / Lapsed |