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:
May. 05, 1992
Filed:
Feb. 21, 1989
Kazunori Ishikawa, Toyota, JP;
Kazumasa Tsukamoto, Toyota, JP;
Takuji Taniguchi, Okazaki, JP;
Yutaka Taga, Aichi, JP;
Aisin Aw Co., Ltd., Aichi, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
An accumulator back pressure control device for an automatic transmission regulates the accumulator back pressure when a shift valve is switched. For example, when up-shifting from first to second speed, when the second brake starts to engage by switching of a shift valve, the rotational speed of the input is varied to change the output torque of the transmission gear mechanism. By detecting the change in rotational speed with a sensor, a pressure control valve (linear solenoid) is controlled by signals from a control unit so that the control pressure is regulated at a desired time. Thus, for example, the change of hydraulic pressure at a control pressure port regulates the oil source pressure (line pressure) and applies such regulated pressure to the back pressure chamber of an accumulator to change the back pressure of the accumulator. When shifting from second to third speed, the back pressure of another accumulator is similarly controlled, and when shifting from third to fourth speed, the back pressure of still another accumulator is similarly controlled. When down-shifting, the operations are preformed in the same manner as described above.