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:
Jun. 09, 2009
Filed:
Oct. 04, 2005
Tetsuya Izumi, Yokohama, JP;
Hironori Nihei, Kanagawa, JP;
Seonjae Kim, Yokohama, JP;
Takayuki Tanaka, Kanagawa, JP;
Toshiji Iida, Kanagawa, JP;
Tetsuya Izumi, Yokohama, JP;
Hironori Nihei, Kanagawa, JP;
Seonjae Kim, Yokohama, JP;
Takayuki Tanaka, Kanagawa, JP;
Toshiji Iida, Kanagawa, JP;
JATCO Ltd, Fuji-shi, Shizuoka, JP;
Abstract
In a line pressure control apparatus of a belt-drive CVT, a shift is achieved by varying V- groove widths of primary and secondary pulleys by a differential pressure between primary and secondary pulley pressures, originating from line pressure. The differential pressure is created by bringing a shift actuator, such as a step motor, into a control position corresponding to a target transmission ratio. The target transmission ratio is calculated based on a theoretical transmission ratio based on engine-and-vehicle operating conditions, taking account of a hardware response delay and a disturbance. The target transmission ratio is converted into a reference-model operative position, corresponding to a reference-model number-of-steps of the shift actuator. An actual transmission ratio is converted into an actual-transmission-ratio related operative position. Line pressure is corrected in a manner so as to reduce the positional deviation between the reference-model operative position and the actual-transmission-ratio related operative position.