| 摘要 |
PURPOSE: A pressure regulating valve of a hydraulic control system in an automatic transmission for a vehicle is provided to enlarge the control range by responding promptly with applying control pressure to an operating land of a valve spool entirely in supplying regulating pressure from a solenoid valve. CONSTITUTION: A pressure control valve of a hydraulic control system is composed of a valve body and a valve spool. The valve body consists of a first port receiving decompressed hydraulic pressure from a reducing valve, a second port receiving hydraulic pressure from a manual valve, a third port supplying hydraulic pressure to a shift valve, and a fourth port(58) receiving control pressure from a solenoid valve. The valve spool has a first land having a small diameter, a second land opening and closing the second port selectively, and a third land(64) connecting the second port to the third port. A groove(70) is formed in the surface of the third land to connect a bore part and an outer diameter part. Responsiveness is improved with applying hydraulic pressure to the entire area of the land promptly by supplying control pressure from the solenoid valve. The control is performed efficiently with enlarging the control range.
|
