US4471438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lock-up type automatic transmission
Assignee: Nissan Motor Co Ltd
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Filing: 1981-05-22
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Granted: 1984-09-11
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Expires: 2001-05-22
Abstract
Abstract A lock-up control system for a lock-up type automatic transmission. A load detection circuit generates a reference acceleration signal that indicates a reference acceleration, and an actual acceleration signal that indicates an actual acceleration of an automotive vehicle. The circuit compares the actual acceleration signal with the reference acceleration signal for generating a first command signal when the actual acceleration signal is greater than the reference acceleration signal and generating a second command signal when the actual acceleration signal is smaller than the reference acceleration signal. The first command signal is fed to a first vehicle speed comparator means to render it operative. The second command signal is fed to a second vehicle comparator means to render same operative. Each of the first and second comparator means compares the vehicle speed signal with a set of reference vehicle speeds for generating a plurality of patterns of signals that indicate a corresponding plurality of lock-up ranges.
Inventors
- 👤 Masaaki Futagi
- 👤 Masaaki Suga
- 👤 Hideo Hamada
- 👤 Tadashi Suzuki
- 👤 Yoshiro Morimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:47
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/14; F16H61/143
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
208 words
A lock-up control system for an automatic transmission for a vehicle, the automatic transmission being shiftable between a plurality of gear ratios and having a lock-up torque converter shiftable between a lock-up operation state and a torque converter operation state in a first predetermined shift pattern, the lock-up control system comprising: vehicle speed signal generating means for producing a vehicle speed signal indicative of a vehicle speed; gear ratio signal generating means for determining which of the plurlity of gear ratios is selected in the automatic transmission and for producing a gear ratio signal indicative of the selected gear ratio; reference acceleration signal generating means responsive to said vehicle speed signal and said gear ratio signal for producing a reference acceleration signal indicative of a reference acceleration; actual acceleration signal generating means responsive to said vehicle speed signal for producing an actual acceleration signal indicative of an actual acceleration of the vehicle; comparing means for comparing said actual acceleration signal with said reference acceleration signal and generating a command signal; and means for changing from the first predetermined shift pattern to a second predetermined shift pattern in response to said command signal and for causing the lock-up torque converter to effect shifting in said second predetermined shift pattern.
Claim 2
Dependent Claim
208 words
A lock-up control system for an automatic transmission for a vehicle, the automatic transmission being shiftable between a plurality of gear ratios and having a lock-up torque converter shiftable between a lock-up operation state and a torque converter operation state in a first predetermined shift pattern, the lock-up control system comprising: vehicle speed signal generating means for producing a vehicle speed signal indicative of a vehicle speed; gear ratio signal generating means for determining which of the plurlity of gear ratios is selected in the automatic transmission and for producing a gear ratio signal indicative of the selected gear ratio; reference acceleration signal generating means responsive to said vehicle speed signal and said gear ratio signal for producing a reference acceleration signal indicative of a reference acceleration; actual acceleration signal generating means responsive to said vehicle speed signal for producing an actual acceleration signal indicative of an actual acceleration of the vehicle; comparing means for comparing said actual acceleration signal with said reference acceleration signal and generating a command signal; and means for changing from the first predetermined shift pattern to a second predetermined shift pattern in response to said command signal and for causing the lock-up torque converter to effect shifting in said second predetermined shift pattern.
Claim 3
Dependent Claim
48 words
A lock-up control system as claimed in claim 1, wherein said reference acceleration corresponds to an acceleration obtained when the vehicle operates on a horizontal flat road for the vehicle speed indicated by said vehicle speed signal and for the gear ratio indicated by said gear ratio signal.
Claim 4
Dependent Claim
168 words
A lock-up control system as claimed in claim 2, wherein: said comparing means generates a first command signal when said actual acceleration signal has a first predetermined relationship with said reference acceleration signal, and a second command signal when said actual acceleration signal has a second predetermined relationship with said reference acceleration signal; and said changing means comprises a first comparator for comparing said vehicle speed signal with a first plurality of predetermined reference values which respectively correspond to said plurality of gear ratios, when said first command signal is present, and a second comparator for comparing said vehicle speed signal with a second plurality of predetermined reference values which respectively correspond to said plurality of gear ratios when said second command signal is present, and a logic gate coupled to said first and second comparators for producing a lock-up signal in response to a comparison by said first comparator or by said second comparator, and means responsive to said lock-up signal for locking said lock-up torque converter.
Claim 5
Dependent Claim
26 words
A lock-up torque converter as claimed in claim 3, further comprising hysteresis setting means responsive to said second command signal for decreasing said actual acceleration signal.
Claim 6
Dependent Claim
234 words
A lock-up control system for an automatic transmission for a vehicle having an engine and a throttle, the automatic transmission being shiftable between a plurality of gear ratios and having a lock-up torque converter shiftable between a lock-up operation state and a torque converter operation state in a first predetermined shift pattern, the lock-up control system comprising: vehicle speed signal generating means for producing a vehicle speed signal indicative of a vehicle speed; throttle opening signal generating means for producing a throttle opening signal indicative of a degree of opening of said throttle; gear ratio signal generating means for determining which of the plurality of gear ratios is selected and producing a gear ratio signal indicative of the selected gear ratio; reference acceleration signal generating means responsive to said vehicle speed signal, said throttle opening signal, and said gear ratio signal, for producing a reference acceleration signal indicative of a reference acceleration; actual acceleration signal generating means responsive to said vehicle speed signal for producing an actual acceleration indicative signal indicative of an actual acceleration of the vehicle; comparing means for comparing said actual acceleration signal with said reference acceleration signal and generating a command signal; and means for changing from said first predetermined shift pattern into a second predetermined shift pattern in response to said command signal and for causing the lock-up torque converter to effect shifting in said second predetermined shift pattern.
Claim 7
Dependent Claim
234 words
A lock-up control system for an automatic transmission for a vehicle having an engine and a throttle, the automatic transmission being shiftable between a plurality of gear ratios and having a lock-up torque converter shiftable between a lock-up operation state and a torque converter operation state in a first predetermined shift pattern, the lock-up control system comprising: vehicle speed signal generating means for producing a vehicle speed signal indicative of a vehicle speed; throttle opening signal generating means for producing a throttle opening signal indicative of a degree of opening of said throttle; gear ratio signal generating means for determining which of the plurality of gear ratios is selected and producing a gear ratio signal indicative of the selected gear ratio; reference acceleration signal generating means responsive to said vehicle speed signal, said throttle opening signal, and said gear ratio signal, for producing a reference acceleration signal indicative of a reference acceleration; actual acceleration signal generating means responsive to said vehicle speed signal for producing an actual acceleration indicative signal indicative of an actual acceleration of the vehicle; comparing means for comparing said actual acceleration signal with said reference acceleration signal and generating a command signal; and means for changing from said first predetermined shift pattern into a second predetermined shift pattern in response to said command signal and for causing the lock-up torque converter to effect shifting in said second predetermined shift pattern.
Claim 8
Dependent Claim
60 words
A lock-up control system as claimed in claim 5, wherein said reference acceleration corresponds to an acceleration obtained when the vehicle operates on a horizontal flat road for the vehicle speed indicated by said vehicle speed signal; and for the throttle opening degree indicated by said throttle opening signal and for the gear ratio indicated by said gear ratio signal.
Claim 9
Dependent Claim
166 words
A lock-up control system as claimed in claim 6, wherein said comparing means generates a first command signal when said actual acceleration signal has a first predetermined relationship with said reference acceleration signal and a second command signal when said actual acceleration signal has a second predetermined relationship with said reference acceleration signal, and said changing means comprises a first comparator for comparing said vehicle speed signal with a first plurality of predetermined reference values which respectively correspond to said plurality of gear ratios when said first command signal is present, a second comparator for comparing said vehicle speed signal with a second predetermined plurality of reference values which respectively correspond to said plurality of gear ratios when said second command signal is present, a logic gate coupled to said first and second comparators for producing a lock-up signal in response to a comparison by said first comparator or by said second comparator, and means responsive to said lock-up signal for locking said lock-up torque converter.
Claim 10
Dependent Claim
26 words
A lock-up control system as claimed in claim 7, further comprising hysteresis setting means responsive to said second command signal for decreasing said actual acceleration signal.
Claim 11
Dependent Claim
149 words
A lock-up control system for an automatic transmission for a vehicle, the automatic transmission being shiftable between a plurality of gear ratios and having a lock-up torque converter shiftable between a lock-up operation state and a torque converter operation state in a first predetermined shift pattern, the lock-up control system comprising: vehicle speed signal generating means for producing a vehicle speed signal indicative of a vehicle speed; actual acceleration signal generating means responsive to said vehicle speed signal for producing an actual acceleration of the vehicle; means for generating a reference acceleration signal; comparing means for comparing said actual acceleration signal with said reference acceleration signal and generating a command signal; and means for changing from said first predetermined shift pattern into a second predetermined shift pattern in response to said command signal and for causing the lock-up torque converter to effect shifting in said second predetermined shift pattern.
Claim 12
Dependent Claim
149 words
A lock-up control system for an automatic transmission for a vehicle, the automatic transmission being shiftable between a plurality of gear ratios and having a lock-up torque converter shiftable between a lock-up operation state and a torque converter operation state in a first predetermined shift pattern, the lock-up control system comprising: vehicle speed signal generating means for producing a vehicle speed signal indicative of a vehicle speed; actual acceleration signal generating means responsive to said vehicle speed signal for producing an actual acceleration of the vehicle; means for generating a reference acceleration signal; comparing means for comparing said actual acceleration signal with said reference acceleration signal and generating a command signal; and means for changing from said first predetermined shift pattern into a second predetermined shift pattern in response to said command signal and for causing the lock-up torque converter to effect shifting in said second predetermined shift pattern.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |