Patent ID: 6478050
Filing Date: 2002-11-12
Classification: F16H,Y10T

Abstract:
A manual valve of a hydraulic pressure control system for an automatic transmission of a vehicle, comprising:a valve body provided with a line pressure receiving port, a P/N range port for supplying hydraulic pressure in more than one of parking range P and neutral range N, a plurality of hydraulic pressure supplying ports and a plurality of exhaust ports; and a valve spool slidably inserted into the valve body and having a plurality of valve lands, a first valve land of said plurality of valve lands having an exhaust groove depressed toward a neighboring land; wherein: each width of the line pressure receiving port and the P/N range port is smaller than each diameter of said plurality of valve lands, whereby a tight seal is maintained when each of the line pressure receiving port and the P/N range port is blocked by said plurality of valve lands; and each width of the plurality of hydraulic pressure supplying ports is greater than each diameter of said plurality of valve lands, whereby hydraulic pressure reserved in each of said plurality of hydraulic pressure supplying ports is exhausted through the exhaust groove when blocked by the first land.