| 摘要 |
PURPOSE: A hydraulic control system of an automatic transmission for a vehicle is provided to improve control response performance and to minimize additional operation elements by sharing a back pressure control route of an accumulator applied for a friction element and controlling the back pressure by a solenoid valve. CONSTITUTION: A hydraulic control system of an automatic transmission for a vehicle regulates hydraulic pressure generated from an oil pump in starting an engine at the constant pressure by a regulator valve, supplies some of the hydraulic pressure to operation pressure of a damper clutch and a reducing valve and the rest of the hydraulic pressure to a plurality of friction elements(C2,C3,B2) by a hydraulic control unit comprising a shift control device, a hydraulic control device, a switching device, a fail safe device, and an N-R control device for supplying selectively the operation pressure to the friction elements operated at each shift level. The hydraulic control system shares a back pressure route of accumulators(AC2,AC3,AC4) applied on the friction elements that are not operated at the same time and arranges a solenoid valve controlled by a transmission control unit to regulate the back pressure in the back pressure route.
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