Patent ID: 6102176
Filing Date: 2000-08-15
Classification: F16H,Y10S

Abstract:
A hydraulic circuit for a transmission, comprising:a regulator valve connected to a hydraulic pump driven by a motor, for regulating oil discharged from the hydraulic pump to produce line pressure;a plurality of control valves connected to said regulator valve to receive said line pressure, for controlling an operation of the transmission using said line pressure, said control valves including at least one electric control valve;a restrictor formed on a discharge oil passage which is connected to said regulator valve;a bypass oil passage for connecting the upstream side and the downstream side of said restrictor while bypassing said restrictor;a bypass closing valve, connected to said bypass oil passage, for closing said bypass oil passage by receiving oil pressure produced when a supply of power to said at least one electric control valve is stopped; anda signal pressure generating valve, connected to said discharge oil passage, for generating signal pressure which corresponds to one of oil pressure on the upstream side of said restrictor and an oil pressure difference between the upstream side and the downstream side when said bypass oil passage is closed.