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:
Dec. 10, 1996
Filed:
Mar. 06, 1996
Tetsuo Hamajima, Toyota, JP;
Hidehiro Oba, Aichi-ken, JP;
Hiromichi Kimura, Okazaki, JP;
Masahiko Ando, Okazaki, JP;
Akira Fukatsu, Anjo, JP;
Yoshihisa Yamamoto, Nishio, JP;
Masahiro Hayabuchi, Anjo, JP;
Kazumasa Tsukamoto, Toyota, JP;
Aisin Aw Co., Ltd., , JP;
Abstract
A shift control system for shifting an automatic transmission from a predetermined gear stage to another by draining an oil pressure from predetermined frictional engagement element to release the same frictional engagement element and by feeding the oil pressure to another frictional engagement element to engage the same frictional engagement element while controlling the drain oil pressure of the frictional engagement element to be released and the engaging oil pressure to the frictional engagement element to be engaged. The shift control system includes an engine racing detector for detecting the racing of the engine while the transmission is being shifted in a clutch-to-clutch manner, and a hydraulic control circuit for controlling at least one of the drain oil pressure and the engaging oil pressure, on the basis of the degree of racing of the engine, as detected by the engine racing detector, such that the amount of racing of the engine falls within a predetermined range. Since the rotational state of the engine being shifted is controlled by hydraulic control of the frictional engagement elements participating in the clutch-to-clutch shift, it is possible to reliably prevent any excessive racing of the engine and to prevent reduction of output shaft torque due to the tie-up of the frictional engagement elements.