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:
Apr. 28, 2009
Filed:
Jul. 06, 2006
Kazutoshi Nozaki, Aichi-gun, JP;
Atsushi Honda, Seto, JP;
Akiharu Abe, Toyota, JP;
Hirofumi Ota, Toyota, JP;
Kazutoshi Nozaki, Aichi-gun, JP;
Atsushi Honda, Seto, JP;
Akiharu Abe, Toyota, JP;
Hirofumi Ota, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, JP;
Abstract
In a hydraulic control apparatus for a vehicular automatic transmission, if it is determined that there is a failure that may cause tie-up in an automatic transmission, communication is provided between a first output port and a first drain port in a switching valve. As a result, a hydraulic frictional engagement device, which should be disengaged when there is a failure, is disengaged. Also, a specific shift speed is achieved by controlling the switching valve. Therefore, it is not necessary to select a shift speed that is achieved on the condition that the hydraulic frictional engagement device, which should be disengaged when there is a failure, is engaged. Thus, it is possible to prevent a shift that may impair driveability when there is a failure that may cause tie-up in the automatic transmission.