US4843922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic control system for automatic transmission
Assignee: Toyota Motor Corp
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Filing: 1988-02-22
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Granted: 1989-07-04
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Expires: 2008-02-22
Abstract
Abstract A hydraulic control system for an automatic transmission detects the rotating speed of the parts whose rotating speed varies due to shifting, and controls the transitional oil pressure applied to the frictionally engaging device in the automatic transmission so that the detected rotating speed matches the locus of the target rotating speed that said parts should follow after the shift command is outputted. Thus, the optimum shifting transitional characteristics can be obtained regardless of the inherent differences among otherwise identical vehicles which differences are created at the time of manufacturing or vary with time and vehicle use.
Inventors
- 👤 Yuji Kashihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:48
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/04; F16H61/06; F16H61/061; F16H61/065; F16H61/067; F16H59/00; F16H59/68; F16H2059/6807; F16H2061/0075; F16H2061/0078; F16H61/02; F16H61/0202; F16H61/0251; F16H2061/0255; F16H59/36; F16H59/38; F16H59/42; F16H59/46
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
128 words
A hydraulic control system for an automatic transmission which includes a frictionally engaging device, comprising: means for detecting the rotating speed of at least one part whose rotating speed is varied during transmission shifting; means for determining the locus of the target rotating speed that said part must follow after a command of said shifting: means for detecting the difference between said target rotating speed and the actual rotating speed; means for detecting a varying state of said difference between the target rotating speed and the actual rotating speed; and means for controlling a transitional oil pressure applied to the frictionally engaging device in accordance with the varying state of said difference so that the rotating speed of said part varies in accordance with said target rotating speed.
Claim 2
Dependent Claim
128 words
A hydraulic control system for an automatic transmission which includes a frictionally engaging device, comprising: means for detecting the rotating speed of at least one part whose rotating speed is varied during transmission shifting; means for determining the locus of the target rotating speed that said part must follow after a command of said shifting: means for detecting the difference between said target rotating speed and the actual rotating speed; means for detecting a varying state of said difference between the target rotating speed and the actual rotating speed; and means for controlling a transitional oil pressure applied to the frictionally engaging device in accordance with the varying state of said difference so that the rotating speed of said part varies in accordance with said target rotating speed.
Claim 3
Dependent Claim
36 words
A hydraulic control system as set forth in claim 1, further comprising: means for detecting different types of transmission shiftings, and said locus of said target rotating speed is determiined for each of said shifting types.
Claim 4
Dependent Claim
39 words
A hydraulic control system as set forth in claim 1, further comprising: means for detecting pattern selecting state of said automatic transmission, and said locus of said target rotating speed is determined for each of said pattern selecting states.
Claim 5
Dependent Claim
39 words
A hydraulic control system as set forth in claim 1, further comprising: means for detecting torque being inputted to said automatic transmission, and said locus of said target rotating speed is determined in response to said torque being inputted.
Claim 6
Dependent Claim
51 words
A hydraulic control system as set forth in claim 1, further comprising: means for detecting different types of transmission shiftings; means for detecting pattern selecting state of said automatic transmission; and said locus of said target rotating speed is determined for each of said shifting types and said pattern selecting states.
Claim 7
Dependent Claim
53 words
A hydraulic control system as set forth in claim 1, further comprising: means for detecting different types of transmission shiftings; means for detecting torque being inputted to said automatic transmission; and said locus of said target rotating speed is determined for each of said shifting types in response to said torque being inputted.
Claim 8
Dependent Claim
57 words
A hydraulic control system as set forth in claim 1, further comprising: means for detecting pattern selecting state of said automatic transmission shiftings; means for detecting torque being inputted to said automatic transmission; and said locus of said target rotating speed is determined for each of said pattern selecting states in response to said torque being inputted.
Claim 9
Dependent Claim
67 words
A hydraulic control system as set forth in claim 1, further comprising: means for detecting different types of transmission shiftings; means for detecting pattern selecting state of said automatic transmission, means for detecting torque being inputted to said automatic transmission; and said locus of said target rotating speed is determined for each of said shifting types and pattern selecting states in response to said torque being inputted.
Claim 10
Dependent Claim
33 words
A hydraulic control system as set forth in claim 4, further comprising: means for detecting throttle opening, and said torque being inputted to said automatic transmission is determined according to the throttle opening.
Claim 11
Dependent Claim
33 words
A hydraulic control system as set forth in claim 6, further comprising: means for detecting throttle opening, and said torque being inputted to said automatic transmission is determined according to the throttle opening.
Claim 12
Dependent Claim
33 words
A hydraulic control system as set forth in claim 7, further comprising: means for detecting throttle opening, and said torque being inputted to said automatic transmission is determined according to the throttle opening.
Claim 13
Dependent Claim
33 words
A hydraulic control system as set forth in claim 8, further comprising: means for detecting throttle opening, and said torque being inputted to said automatic transmission is determined according to the throttle opening.
Claim 14
Dependent Claim
60 words
A hydraulic control system as set forth in claim 1, wherein said detecting means for detecting varying state of the difference between the target rotating speed and actual rotating speed detects whether or not the difference between the target rotating speed and actual rotating speed at the present detecting timing is greater than the difference at the preceding detecting timing.
Claim 15
Dependent Claim
69 words
A hydraulic control system as set forth in claim 1, further comprising: an accumulator with a backpressure chamber in an oil passage of said hydraulic control system; an accumulator backpressure control valve for controlling oil pressure applied to said backpressure chamber; and the means for controlling said transitional oil pressure includes the combined means of said accumulator and said accumulator backpressure control valve for controlling said transitional oil pressure.
Claim 16
Dependent Claim
48 words
A hydraulic control system as set forth in claim 1, wherein: the means for controlling said transitional oil pressure adjusts the oil pressure mechanically, and corrects electrically said oil pressure adjusted mechanically so that the actual rotating speed varies according to the locus of the target rotating speed.
Claim 17
Dependent Claim
49 words
A hydraulic control system as set forth in claim 16, wherein: the means for controlling said transitional oil pressure basically adjusts the oil pressure mechanically, and corrects electrically said oil pressure adjusted mechanically so that the actual rotating speed varies according to the locus of the target rotating speed.
Claim 18
Dependent Claim
44 words
A hydraulic control system as set forth in claim 17, further comprising: a throttle pressure valve for controlling the transitional oil pressure mechanically in accordance with a throttle opening, and said means for controlling the transitional oil pressure further includes said throttle pressure valve.
Claim 19
Dependent Claim
44 words
A hydraulic control system as set forth in claim 18, further comprising: a throttle pressure valve for controlling the transitional oil pressure mechanically in accordance with a throttle opening, and said means for controlling the transitional oil pressure further includes said throttle pressure valve.
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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) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |