Planetary gear transmission systems or components – Fluid drive or control of planetary gearing – Fluid controlled mechanical clutch or brake
Reexamination Certificate
2000-10-18
2004-01-20
Bonck, Rodney H. (Department: 3681)
Planetary gear transmission systems or components
Fluid drive or control of planetary gearing
Fluid controlled mechanical clutch or brake
C477S161000, C192S003580, C701S055000
Reexamination Certificate
active
06679800
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a hydraulic pressure control method and apparatus for an automatic transmission for a vehicle, in which a signal pressure is produced by an electrical signal, and an output pressure is controlled by this signal pressure.
BACKGROUND OF THE INVENTION
An automatic transmission for a vehicle performs speed changing by selectively engaging a plurality of frictional elements such as clutches and brakes etc. If at this time the engagement pressure for a frictional element is not appropriate, there is a possibility that speed change shock may occur, or that the speed changing response may be slow.
In this connection, it is proposed in Japanese Patent Laying-Open Publication Heisei 8-270777 to perform transition control for the line pressure which engages the frictional elements.
SUMMARY OF THE INVENTION
A hydraulic pressure control circuit for an automatic transmission produces a signal pressure by driving a solenoid, and controls by this signal pressure an engagement pressure for a frictional element which is an output pressure, or a line pressure which controls engagement of a frictional element, so as to perform speed changing. However there is the problem that the relationship between the drive electrical signal for the solenoid and the output pressure cannot be accurately determined, due to variation or individual differences in circuit resistance.
In order to solve this problem, it has been conceived of to store a complete set of data relating to actually measured output pressure for each level of electrical signal within the control device, to derive from this database the value of electrical signal which corresponds to the required value for the output pressure, and to send an electrical signal of this value as a command to the solenoid. In this case, an expanded memory capacity becomes necessary for storing the above database, and the cost is increased.
REFERENCES:
patent: 4351206 (1982-09-01), Lemieux et al.
patent: 4470117 (1984-09-01), Miki et al.
patent: 4704922 (1987-11-01), Suketomo et al.
patent: 4956776 (1990-09-01), Carre
patent: 4967385 (1990-10-01), Brekkestran et al.
patent: 5054599 (1991-10-01), Marcott
patent: 5213013 (1993-05-01), Fujiwara et al.
patent: 5251509 (1993-10-01), Pollack et al.
patent: 5342253 (1994-08-01), Mizobe et al.
patent: 5404301 (1995-04-01), Slicker
patent: 5802490 (1998-09-01), Droste
patent: 5871074 (1999-02-01), Easton
patent: 5957260 (1999-09-01), Kunii
patent: 6022293 (2000-02-01), Dourra et al.
patent: 6102825 (2000-08-01), Hisano et al.
patent: 6179107 (2001-01-01), Hall, III
patent: 6206802 (2001-03-01), Kim
patent: 6315692 (2001-11-01), Takahashi et al.
patent: 6319164 (2001-11-01), Runde et al.
patent: 199 37 053 (2000-02-01), None
patent: 64-24410 (1989-02-01), None
patent: 05-280623 (1993-10-01), None
patent: 05-312251 (1993-11-01), None
patent: 8-270777 (1996-10-01), None
patent: 09-014485 (1997-01-01), None
patent: 09-100939 (1997-04-01), None
patent: 09-273653 (1997-10-01), None
patent: 11-270731 (1999-10-01), None
Ishii Shigeru
Sugiuchi Masashi
Bonck Rodney H.
Foley & Lardner
Le David D.
Nissan Motor Co,. Ltd.
LandOfFree
Hydraulic pressure control method and apparatus of an... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulic pressure control method and apparatus of an..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulic pressure control method and apparatus of an... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3239851