Patent US2639429A successfully refreshed from Google Patents.
US5035308A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lock-up control system for automatic transmission
Assignee: Mazda Motor Corp
•
Filing: 1988-09-29
•
Granted: 1991-07-30
•
Expires: 2008-09-29
Abstract
Abstract A lock-up control system for an automatic transmission including a torque converter having an input member and an output member, a multiple stage gear transmission gear mechanism connected with the output member of the torque converter and having a plurality of gear stages and a lock-up clutch for connecting the input member and the output member bypassing the torque converter wherein an engaging force in the lock-up clutch is controllable so as to change the amount of torque transmitted through the lock-up clutch. The system comprises shift detecting device for detecting a shift operation in the transmission mechanism and control device for controlling the engaging force of the torque converter to be maintained at a predetermined value smaller than a fully engaged condition of the lock-up clutch and larger than an entirely released condition of the lock-up clutch when the shift operation is detected by the shift detecting device.
Inventors
- 👤 Fumiaki Baba
- 👤 Masanori Izumi
- 👤 Kenji Sawa
- 👤 Susumu Kurumida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:20
CPC Classifications
B; B60; B60K; B60K20/00; B60K20/02; F; F16; F16H; F16H61/00; F16H61/14; F16H61/143; F16H45/00; F16H45/02; F16H2045/0273; F16H2045/0294; F16H2061/145
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
135 words
In a lock-up control system for an automatic transmission including a torque converter having an input member and an output member, a multiple stage gear transmission mechanism connected with the output member of the torque converter and having a plurality of gear stages, and a lock-up clutch for connecting the input member and the output member bypassing the torque converter wherein an engaging force in the lock-up clutch is controllable so as to change the amount of torque transmitted through the lock-up clutch, the improvement comprising: shift detecting means for detecting a shift operation in the transmission mechanism, and control means for maintaining the engaging force at a predetermined value smaller than a fully engaged condition of the lock-up clutch and larger than an entirely released condition of the lock-up clutch throughout the shift operation.
Claim 2
Dependent Claim
135 words
In a lock-up control system for an automatic transmission including a torque converter having an input member and an output member, a multiple stage gear transmission mechanism connected with the output member of the torque converter and having a plurality of gear stages, and a lock-up clutch for connecting the input member and the output member bypassing the torque converter wherein an engaging force in the lock-up clutch is controllable so as to change the amount of torque transmitted through the lock-up clutch, the improvement comprising: shift detecting means for detecting a shift operation in the transmission mechanism, and control means for maintaining the engaging force at a predetermined value smaller than a fully engaged condition of the lock-up clutch and larger than an entirely released condition of the lock-up clutch throughout the shift operation.
Claim 3
Dependent Claim
43 words
A lock-up control system in accordance with claim 1 wherein the control means is provided with compensating means for compensating said predetermined value of the engaging force of the lock-up clutch in accordance with an engine load detected by engine load detecting means.
Claim 4
Dependent Claim
27 words
A lock-up control system in accordance with claim 2 wherein the compensating means increases said predetermined value of the engaging force as the engine load is increased.
Claim 5
Dependent Claim
46 words
A lock-up control system in accordance with claim 1 wherein the control means is provided with compensating means for compensating said predetermined value of the engaging force of the lock-up clutch in accordance with a mode of the shift operation detected by shift mode detecting means.
Claim 6
Dependent Claim
29 words
A lock-up control system in accordance with claim 4 wherein the shift mode detecting means detects whether a shift operation is a shift down operation or shift up operation.
Claim 7
Dependent Claim
35 words
A lock-up control system in accordance with claim 5 wherein the compensating means provides a greater value as said predetermined value of the engaging force in the shift up operation than the shift down operation.
Claim 8
Dependent Claim
24 words
A lock-up control system in accordance with claim 4 wherein the shift mode detecting means detects gear stages selected for a shift up operation.
Claim 9
Dependent Claim
38 words
A lock-up control system in accordance with claim 7 wherein the compensating means reduces said predetermined value of the engaging force as a difference in gear ratio between gear stages selected for the shift up operation is increased.
Claim 10
Dependent Claim
36 words
A lock-up control system in accordance with claim 4 wherein the shift mode detecting means detects a shift down operation during an acceleration operation in which the compensating increases the engaging force of the lock-up clutch.
Claim 11
Dependent Claim
107 words
A lock-up control system in accordance with claim 1 wherein the lock-up clutch is provided with a clutch plate operated in accordance with a hydraulic pressure introduced into an oil chamber for establishing a frictional engagement between the input and output members of the torque converter, the control means being provided with magnetic means for adjusting the hydraulic pressure to thereby keeping the engaging force of the lock-up clutch at a predetermined value, the magnetic means being provided with a duty solenoid actuated base on a variable duty signal in a manner of increasing the engaging force of the lock-up clutch as the duty signal is increased.
Claim 12
Dependent Claim
26 words
A lock-up control system in accordance with claim 10 wherein the control means increases the duty signal for the duty solenoid as engine load is increased.
Claim 13
Dependent Claim
35 words
A lock-up control system in accordance with claim 10 wherein the control means provides a greater value of the duty signal for the duty solenoid in a shift up operation than a shift down operation.
Claim 14
Dependent Claim
38 words
A lock-up control system in accordance with claim 10 wherein the control means reduces the duty signal for the duty solenoid as a difference in gear ratio between gear stages selected for a shift up operation is increased.
Claim 15
Dependent Claim
177 words
In a lock-up control system for an automatic transmission including a torque converter having an input member and an output member, a multiple stage gear transmission gear mechanism connected with the output member of the torque converter and having a plurality of gear stages and a lock-up clutch for connecting the input member and the output member bypassing the torque converter wherein an engaging force in the lock-up clutch is controllable so as to change the amount of torque transmitted through the lock-up clutch, the improvement comprising shift detecting means for detecting a shift operation in the transmission mechanism and control means for providing one of a lock-up condition in which the lock-up clutch is fully engaged, a released condition in which the lock-up clutch is entirely released and a slip condition in which a speed difference between the input and output members of the torque converter falls into a predetermined value resulting from a slippage in the lock-up clutch throughout the shift operation in at least two shift gear stages provided by the transmission gear mechanism.
Claim 16
Dependent Claim
177 words
In a lock-up control system for an automatic transmission including a torque converter having an input member and an output member, a multiple stage gear transmission gear mechanism connected with the output member of the torque converter and having a plurality of gear stages and a lock-up clutch for connecting the input member and the output member bypassing the torque converter wherein an engaging force in the lock-up clutch is controllable so as to change the amount of torque transmitted through the lock-up clutch, the improvement comprising shift detecting means for detecting a shift operation in the transmission mechanism and control means for providing one of a lock-up condition in which the lock-up clutch is fully engaged, a released condition in which the lock-up clutch is entirely released and a slip condition in which a speed difference between the input and output members of the torque converter falls into a predetermined value resulting from a slippage in the lock-up clutch throughout the shift operation in at least two shift gear stages provided by the transmission gear mechanism.
References Cited (Backward Citations)
US4457411A
Cited
EP0042542A2
Cited
US4468988A
Cited
US4509124A
Cited
US4577737A
Cited
US4579208A
Cited
US4580671A
Cited
US4687083A
Cited
US4565267A
Cited
US4618041A
Cited
US4570770A
Cited
EP0153798A1
Cited
US4582185A
Cited
US4640394A
Cited
JPS60256675A
Cited
GB2163230A
Cited
US4669441A
Cited
US4720003A
Cited
US4724939A
Cited
JPS6367461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-29 | 1995-01-28 | 1995-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-29 | 1999-01-28 | 1999-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-29 | 2003-01-28 | 2003-07-30 | $7700.00 | Window Closed / Lapsed |