HYDRAULIC CONTROL DEVICE FOR BELT-TYPE CONTINUOUSLY VARIABLE TRANSMISSION

摘要

PROBLEM TO BE SOLVED: To provide a hydraulic control device for a belt-type continuously variable transmission capable of improving fuel economy by reducing differential pressure between primary pressure and line pressure to reduce a pump loss in overdrive. SOLUTION: The hydraulic control device for the belt-type continuously variable transmission has a line pressure control means for controlling the discharge pressure of an oil pump to obtain line pressure; a first hydraulic control means for controlling first oil pressure supplied to a driving side pulley with the line pressure as initial pressure; and a second hydraulic control means for controlling second oil pressure supplied to a driven side pulley with the line pressure as the initial pressure. The line pressure control means has a line pressure control part for controlling the line pressure to a value obtained by adding allowance pressure to the higher oil pressure between the first oil pressure and the second oil pressure, and lowering the allowance pressure when the first oil pressure is higher than the second oil pressure. COPYRIGHT: (C)2008,JPO&INPIT