Patent ID: 6739998
Filing Date: 2004-05-25
Classification: F16H,Y10T

Abstract:
A hydraulic controller for an automatic transmission, which controls a hydraulic pressure received from a hydraulic pressure generating source, comprising:a solenoid valve which outputs a signal pressure; a first control valve having a first oil chamber and a second oil chamber, arranged in opposition to the first oil chamber, said first oil chamber receiving the signal pressure of the solenoid valve, said first control valve receiving and adjusting the hydraulic pressure from the hydraulic pressure generating source responsive to the signal pressure; a switching valve receiving the hydraulic pressure of the hydraulic pressure generating source and the hydraulic pressure adjusted by the first control valve, and selectively outputting one of the received hydraulic pressures; and an oil passage which receives the output of the switching valve and inputs it into the second oil chamber of the first control valve, wherein when the switching valve outputs the adjusted hydraulic pressure, the hydraulic controller feeds the adjusted hydraulic pressure to said second oil chamber to feedback-control the first control valve, and when the switching valve outputs the hydraulic pressure of the hydraulic pressure generating source, the hydraulic controller feeds the hydraulic pressure of the hydraulic pressure generating source to said second oil chamber to fix the first control valve.