Patent Number: 8,066,595

Title: Hydraulic control system for vehicular power transmitting mechanism

Abstract: A hydraulic control system for a vehicular drive system including a hydraulically operated belt-and-pulley type continuously variable transmission and a hydraulically operated frictional coupling device engaged for running of a vehicle, the hydraulic control system including: a first solenoid valve for regulating a belt-tensioning hydraulic pressure for tensioning a belt of the transmission, a second solenoid valve for regulating a transient coupling hydraulic pressure to be applied to the frictional coupling device in the process of an engaging action, a line-pressure regulating valve for regulating a line pressure used for hydraulically operated devices of the mechanism, and a hydraulic-circuit switching device operable to apply a control pressure of the second solenoid-operated valve to the line-pressure regulating valve after the frictional coupling device has been placed in a fully engaged state, and to apply a first control pressure of the first solenoid-operated valve to the line-pressure regulating valve while the frictional coupling device is in the process of the engaging action.

Inventors: Ogata; Yusuke (Toyota, JP), Soga; Yoshinobu (Toyota, JP), Habuchi; Ryoji (Toyota, JP)

Assignee: Toyota Jidosha Kabushiki Kaisha

International Classification: F16H 59/00 (20060101); F16H 63/00 (20060101); F16H 61/26 (20060101); F16H 7/08 (20060101); F16H 61/662 (20060101); F16H 61/00 (20060101); F16H 7/22 (20060101)

Expiration Date: 2020-11-29 0:00:00