HYDRAULIC CONTROL SYSTEM OF AUTOMATIC TRANSMISSION FOR AUTOMOTIVE VEHICLE

摘要

Disclosed is a hydraulic control system of an automatic transmission for an automotive vehicle. The system comprises a hydraulic pump (32); a pressure regulating valve (34); a torque converter (30); a converter clutch regulator valve (36) for actuating a damper clutch; first, second and third solenoid valves (S1; S2; and S3) controlled by a TCU for supplying the hydraulic pressure or obstructing a supply of the hydraulic pressure which is varied in the pressure regulating valve (34) to shift valves of a transmission control section (BB) to displace valve spools of the shift valves; first friction elements (96) commonly actuated at each speed stage; second, third, fourth and fifth friction elements (68; 76; 86; and 90), at least one of which is actuated according to the speed stages; reverse friction elements (98) actuated at the reverse mode; second speed and third speed clutch valves (64; 72) and a fourth speed band valve (80) controlled by ON/OFF functions and duty control functions of the solenoid valves (S1; S2; and S3) for selectively supplying the hydraulic pressure to the friction elements to perform shifting; a reverse clutch inhibiter valve (56) for obstructing a supply of the hydraulic pressure to a sixth friction element (99) to keep the vehicle from malfunctioning when the reverse mode is selected in error while driving forward; and a manual valve (34) operated by a shift select lever for supplying line pressure to a reverse pressure conduit or to a forward pressure conduit.