초록 ▼

The technical field of the invention generally concerns electronically controlled valves for use in electro-hydraulically controlled transmissions. The valve 20 includes a hollow cage 42 pierced by tank ports 52, clutch ports 54, and by pump ports 56. The pump ports 56 receivefluid from a pump. The

The technical field of the invention generally concerns electronically controlled valves for use in electro-hydraulically controlled transmissions. The valve 20 includes a hollow cage 42 pierced by tank ports 52, clutch ports 54, and by pump ports 56. The pump ports 56 receivefluid from a pump. The clutch ports 54 supply fluid to a hydraulic actuator. The cage clutch ports 54 supply fluid at a pressure that is proportional to an electrical control signal applied to a coil 252 of the valve 20. The tank ports 52 return fluid from the valve 20 to a tank. Located in the cage 42 is a main spool 112 that moves laterally relative to the cage 42 for controlling a flow of hydraulic fluid between the clutch ports 54 and either the pump ports 56 or the tank ports 52. An electro-magnetically operated pilot valve regulates a control pressure of fluid applied to a control pressure surface 138 at one end of the main spool 112. A feedback pressure passage 126, having a feedback restriction orifice 128, couples the pressure of fluid in the clutch ports 54 to a feedback pressure surface 114 at the opposite end of the spool 112. The orifice 128 restrains the rate at which fluid flows between the clutch ports 54 and the feedback pressure surface 114. One embodiment of the valve 20 includes a pressure spike suppression check valve 504 for relieving any abnormally high pressure that occurs in the clutch ports 54.

대표청구항 ▼

[ What is claimed is:] [7.] A method for operating a proportional pressure control cartridge valve comprising the steps of:supplying pressurized hydraulic fluid to a pump formed through a wall of a hollow cage;supplying a flow of hydraulic fluid from the pump port to an electromagnetically operated

[ What is claimed is:] [7.] A method for operating a proportional pressure control cartridge valve comprising the steps of:supplying pressurized hydraulic fluid to a pump formed through a wall of a hollow cage;supplying a flow of hydraulic fluid from the pump port to an electromagnetically operated pilot valve through a pilot valve supply passage formed in a spool;supplying a regulated control pressure of fluid to a control pressure chamber within the cage which control pressure is regulated by an electrical control signal applied to the electromagnetically operated pilot valve proportional pressure control valve, the control pressure chamber including a control pressure surface located on the spool, the spool fitting snugly within the hollow cage and being moveable therein, said control pressure applied to the control pressure surface urging the spool to move relative to the cage to a position in which the spool allows a flow of hydraulic fluid to pass between the pump port in the wall of the cage to a clutch port also formed through the wall of the cage while simultaneously obstructing any flow of hydraulic fluid between the clutch port and a tank port also formed through the wall of the cage;supplying a feedback pressure of fluid from the clutch port to a feedback pressure chamber within the cage, the feedback pressure chamber including a feedback pressure surface on the spool, said feedback pressure applied to the feedback pressure surface urging the spool to move relative to the cage to a position in which the spool obstructs any flow of hydraulic fluid between the pump port and the clutch port while simultaneously allowing a flow of hydraulic fluid to pass between the clutch port and the tank port;restraining the rate at which fluid may flow between the clutch port in the cage and the feedback pressure chamber; andrelieving any abnormally high pressure that occurs in the clutch port in response to a difference in hydraulic fluid pressure between the clutch port and the control pressure chamber.