Patent US4766774A successfully refreshed from Google Patents.
US4766774A
Expired / Lapsed
US
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Shift control method and apparatus for automatic transmissions used in automotive vehicles
Assignee: Isuzu Motors Ltd
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Filing: 1986-08-19
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Granted: 1988-08-30
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Expires: 2006-08-19
Abstract
Abstract At an initial shifting operation of an automatic transmission, a shift actuator is operated to move a shift fork shaft to an initial target gear shift position which is deepest, followed by removing driving force from the actuator. A value is then read in from a stroke sensor for sensing the position of the actuator that prevails when a detent mechanism of the transmission is in a stable state. Shifting control is performed by using the read value as a target value for the next shifting operation.
Inventors
- 👤 Hidefumi Tamai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:29
CPC Classifications
F; F16; F16H; F16H59/00; F16H61/00; F16H61/26; F16H61/28; B; B60; B60W; B60W10/00; B60W10/10; B60W10/11; F16H2061/0075; F16H2061/0087; F16H2061/2823; F16H59/68; F16H63/00; F16H63/02; F16H63/30; F16H63/38; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19219; Y10T74/19251; Y10T74/20; Y10T74/20012; Y10T74/20018; Y10T74/2003
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
212 words
A method of controlling the shifting of an automotive automatic transmission having a detent mechanism for performing shift positioning of a shift fork shaft which actuates a clutch sleeve of the transmission, a shift actuator for actuating the shift fork shaft, a stroke sensor for constantly sensing an operating position of the shift actuator, and an electronic control unit for controlling drive of the shift actuator, said method comprising: a first step in which the electronic control unit operates the shift actuator at an initial shifting operation of the transmission to move the shift fork shaft for each and every gear stage to the position of a maximum stroke for which said clutch sleeve is designed to move; a second step in which the electronic control unit removes driving force from the shift actuator at the end of said first step; a third step, executed at the end of said second step, in which the electronic control unit reads in a value from the stroke sensor that prevails when the detent mechanism is in a stable state; and a fourth step, executed at the end of said third step, in which the electronic control unit selects the read value from the stroke sensor as a target value for the next shifting operation.
Claim 2
Independent Claim
212 words
A method of controlling the shifting of an automotive automatic transmission having a detent mechanism for performing shift positioning of a shift fork shaft which actuates a clutch sleeve of the transmission, a shift actuator for actuating the shift fork shaft, a stroke sensor for constantly sensing an operating position of the shift actuator, and an electronic control unit for controlling drive of the shift actuator, said method comprising: a first step in which the electronic control unit operates the shift actuator at an initial shifting operation of the transmission to move the shift fork shaft for each and every gear stage to the position of a maximum stroke for which said clutch sleeve is designed to move; a second step in which the electronic control unit removes driving force from the shift actuator at the end of said first step; a third step, executed at the end of said second step, in which the electronic control unit reads in a value from the stroke sensor that prevails when the detent mechanism is in a stable state; and a fourth step, executed at the end of said third step, in which the electronic control unit selects the read value from the stroke sensor as a target value for the next shifting operation.
Claim 3
Dependent Claim
58 words
A method according to claim 1, further comprising a fifth step in which, when the position of the maximum stroke which is designed is not attained within a predetermined period of time after a gear shifting operation starts in said second step, the electronic control unit halts the gear shifting operation and performs the gear shifting operation again.
Claim 4
Dependent Claim
107 words
A method according to claim 2, further comprising a sixth step in which the electronic control unit judges whether a present gear shift position is of a manufacturing error range for a designed stroke position for the clutch sleeve, and a seventh step in which the electronic control unit judges whether an initial gear shifting operation is completed when the present gear shift position is within the manufacturing error range, these steps being executed in a case where the position of the maximum stroke which is designed is not attained even when the gear shifting operation is repeated a predetermined number of times in said fifth step.
Claim 5
Dependent Claim
157 words
A shift control apparatus for a vehicular automatic transmission having a clutch sleeve of the transmission, a shift fork shaft which actuates the clutch sleeve, and a detent mechanism for performing shift positioning of the shift fork shaft, said shift control apparatus comprising: a shift actuator for actuating the shift fork shaft; a stroke sensor for constantly sensing an operating position of said shift actuator; reading means for reading in a value from said stroke sensor that prevails in a state where the detent mechanism has stabilized, this being performed after said shift actuator moves the shift fork shaft for each gear stage to the position of a maximum stroke which is designed for said clutch sleeve to move at an initial shifting operation of the transmission and a driving force is removed from said shift actuator; and means for selecting the value read by said reading means as a target value for the next shifting operation.
Claim 6
Dependent Claim
157 words
A shift control apparatus for a vehicular automatic transmission having a clutch sleeve of the transmission, a shift fork shaft which actuates the clutch sleeve, and a detent mechanism for performing shift positioning of the shift fork shaft, said shift control apparatus comprising: a shift actuator for actuating the shift fork shaft; a stroke sensor for constantly sensing an operating position of said shift actuator; reading means for reading in a value from said stroke sensor that prevails in a state where the detent mechanism has stabilized, this being performed after said shift actuator moves the shift fork shaft for each gear stage to the position of a maximum stroke which is designed for said clutch sleeve to move at an initial shifting operation of the transmission and a driving force is removed from said shift actuator; and means for selecting the value read by said reading means as a target value for the next shifting operation.
Claim 7
Dependent Claim
14 words
An apparatus according to claim 4, wherein said shift actuator is a hydraulic actuator.
Claim 8
Dependent Claim
15 words
An apparatus according to claim 4, wherein said transmission is a parallel shaft gear-type transmission.
References Cited (Backward Citations)
US4539858A
Cited
US4543856A
Cited
JPS5997349A
Cited
US4625577A
Cited
US4646582A
Cited
US4580457A
Cited
EP0130811A1
Cited
EP0130812A1
Cited
EP0134646A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |