The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 21, 1999
Filed:
Aug. 12, 1997
Masao Saito, Anjo, JP;
Masaharu Chiba, Anjo, JP;
Masayuki Kuwata, Anjo, JP;
Masatoshi Taguchi, Anjo, JP;
Kenji Suzuki, Anjo, JP;
Hiroshi Tsutsui, Anjo, JP;
Aisin AW Co., LTD., , JP;
Abstract
A hydraulic control unit of an automatic transmission calculates deceleration during a coasting downshift, and calculates a piston play offsetting time, that is, the lag time that elapses between a shift decision and the start of the shift, on the basis of a correction value determined in accordance with the lag time learned from the previous shift. Based on the rate of deceleration and the piston play offsetting time, the downshift line in the speed shift map is corrected, that is, advanced in timing. Using this timing-advanced shift line, the control unit makes an earlier shift decision such that the shift starts in a proper state of operation, thus reducing shift shock during a coasting downshift and preventing excessive engine speed during a high-speed upshift.