| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic control device capable of reducing pump loss while securing each hydraulic pressure required on the primary side and the secondary side of a hydraulic control circuit of a belt continuously variable transmission. SOLUTION: In this hydraulic control device, the hydraulic control circuit 200 of the belt continuously variable transmission comprises a line pressure control circuit L2 having a pressure regulating valve V1, a primary side hydraulic pressure control circuit L3 having a primary side pressure reducing valve V2, and a secondary side hydraulic pressure control circuit L4 having a secondary side pressure reducing valve V3. A line pressure PL is aligned with one of the set values of a primary side target hydraulic pressure and a secondary side target hydraulic pressure set according to the reduction gear ratio, whichever is higher, and applied to the higher target hydraulic pressure without reduction. Since merely a minimum hydraulic pressure is required for the line pressure, the discharge pressure of an oil pump 20 can be set lower. Consequently, the pump loss can be reduced. COPYRIGHT: (C)2008,JPO&INPIT |
