Patent ID: 8393999

Claim:
A hydraulic control system for a transmission to control hydraulic pressure for adjusting sheave pressures applied to a drive pulley and a driven pulley, both being wound with a belt thereabout, wherein the transmission varies the speed by changing the belt winding radii of the pulleys in accordance with the sheave pressures, the system comprising: a first solenoid valve for generating a first solenoid pressure to adjust the first sheave pressure to be applied to the drive pulley; a second solenoid valve for generating a second solenoid pressure to adjust the second sheave pressure to be applied to the driven pulley; a first sheave pressure adjustment valve for adjusting line pressure serving as a source control pressure in accordance with the first solenoid pressure so as to generate the first sheave pressure; a second sheave pressure adjustment valve for adjusting the line pressure in accordance with the second solenoid pressure so as to generate the second sheave pressure; and line pressure adjustment mechanism for adjusting the line pressure based on the first sheave pressure and the second solenoid pressure.