| 摘要 |
Disclosed is a hydraulic control system of an automatic transmission for a vehicle which includes a pressure regulator for regulating hydraulic pressure created by an oil pump, manual and automatic shift controllers for forming a shift mode according to a position of a shift selection lever, a hydraulic controller for controlling shift quality and shift response to smoothly change transmission speeds when shifting, and a hydraulic pressure distributor and release mechanism which distributes an appropriate amount of hydraulic pressure to and releases pressure from each of the friction elements in the automatic transmission, wherein the hydraulic distribution and release means has a 2-4/3-4 shift valve, a 2-3/4-3 shift valve, and an end-clutch valve for supplying to or releasing from friction elements hydraulic pressure, controlled by first and second pressure control valves of the hydraulic pressure controller, through port conversion realized by control pressure, supplied to lines for each speed through a shift control valve operated according to ON/OFF states of solenoid valves by a transmission control unit, the 2-3/4-3 shift valve being connected to a line to which an exhaust port provided with an orifice is installed. |
