摘要 |
A hydraulic control system for an automatic transmission, the system including: a fluid pump; a proportional control valve for reducing a hydraulic pressure in accordance with a vehicle speed; a valve body including a line pressure inlet port for receiving the hydraulic pressure compressed by a fluid pump, a line pressure outlet port for flowing out the hydraulic pressure to be used as a driving pressure in a "D" range; a reverse pressure port for flowing out the hydraulic pressure to be used as the driving pressure in an "R" range; and a first, a second, a third and a fourth speed ports for receiving the hydraulic pressure from the line pressure outlet port and for flowing out the hydraulic pressure to shift a speed stage in accordance with a vehicle speed; a manual valve rotatably disposed in the valve body and rotates in accordance with a movement of a shift lever; and a shift control valve rotatably disposed in a same concentric axis with said manual valve in the valve body; the manual valve including a neck portion, the neck portion integrally forming a first, a second and a third blades thereon for selectively supplying the line pressure to the line pressure inlet port, the line pressure outlet port, and the reverse pressure port. |