| 摘要 |
A pressure control valve for a selectively engageable friction device (10) has two flow rates for controlling piston movement during the application of the friction device. …<??>The valve (58) includes a spring-loaded valve capsule (60) slidably disposed in a stepped-diameter bore (44) between a feed passage (52) and a control passage (36). When the fluid pressure in the feed passage exceeds the fluid pressure in the control passage by a predtermined amount, the capsule is thereby moved in the bore against the bias of the spring (70) so tht the outer cylindrical surface of the capsule and the largest-diameter portion (46) or the bore co-operate to form an orifice which permits a high flow rate, resulting in a rapid fill operation of the piston cylinder (24) of the friction device. …<??>The pressure in the piston cylinder, sensed in the control passage, and the biasing force of the spring move the capsule into the next-largest diameter portion of the bore to provide a reduced flow during the final pressurization of the piston cylinder of the friction device. …<??>A cheque valve (62) in the capsule permits rapid exhausting of the friction device when the feed passage is exhausted. |
