Patent ID: 8287409
Filing Date: 2012-10-16
Classification: F16H,Y10T

Abstract:
1. A hydraulic control system that is applied to a belt-type continuously variable transmission that includes a drive pulley and a driven pulley, around which a belt is wound, and that changes the belt turning radii of the pulleys on the basis of hydraulic pressures applied respectively to the pulleys to shift gears, wherein the hydraulic control system performs hydraulic control to regulate the hydraulic pressures applied respectively to the pulleys, the hydraulic control system comprising: a first sheave pressure regulating valve that regulates a line pressure to obtain a first sheave pressure; a fail-safe valve that selects and outputs any one of the first sheave pressure and a fail-safe hydraulic pressure to one of the pulleys; and a line pressure regulating portion that regulates the line pressure on the basis of an output pressure from the fail-safe valve, wherein the line pressure is used as a source pressure for hydraulic control.