Proportional pressure control valve

Abstract

The technical field of the invention generally concerns electronically controlled hydraulic valves adapted for use in electro-hydraulically controlled automotive transmissions. The proportional pressure control valve 20 includes a hollow cage 42 pierced by cage tank ports 52, cage clutch ports 54, and by cage pump ports 56. The cage pump ports 56 receive fluid from a pump. The cage clutch ports 54 supply fluid to a hydraulic actuator, such as that for an automotive clutch. The cage clutch ports 54 supply the fluid at a pressure that is proportional to an electrical control signal applied to a solenoid coil 252 of the valve 20. The cage tank ports 52 return fluid from the valve 20 to a tank from which the fluid circulates back to the pump. Located in the cage 42 is a main spool 112 that is movable laterally relative to the cage 42 for controlling a flow of hydraulic fluid between the cage clutch ports 54 and either the cage pump ports 56 or the cage 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 cage clutch ports 54 to a feedback pressure surface 114 at the opposite end of the spool. The feedback restriction orifice 128 restrains the rate at which fluid may flow between the cage 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 cage clutch ports 54.

What is claimed is:  
     
         1 . A proportional pressure control valve comprising: 
 a hollow cage that includes a wall pierced by a pump port that is adapted for receiving fluid from a pump at a pressure provided by the pump, the wall also being pierced by a clutch port that is adapted for supplying pressurized fluid to a hydraulic actuator, and the wall also being pierced by a tank port that is adapted for supplying fluid to a tank;    a main spool adapted to be positioned within said hollow cage in which location said main spool is moveable relative to said cage for controlling a flow of fluid passing between the clutch port in said cage and either the pump port or the tank port in said cage, said main spool including a control pressure surface to which pressure may be applied for urging said main spool to move within said cage to a position in which said main spool allows a flow of fluid to pass between the pump port and the clutch port, said main spool also including a feedback pressure surface to which pressure may be applied for urging said main spool to move within said cage to a position in which said main spool allows a flow of fluid to pass between the clutch port and the tank port;    a control pressure chamber located within said cage for receiving fluid under pressure and applying the pressure of the fluid to the control pressure surface of said main spool;    an electromagnetically operated pilot valve means for supplying a regulated pressure of fluid to said control pressure chamber responsive to an electrical control signal;    a feedback pressure chamber located within said cage for receiving fluid at a pressure and coupling the pressure of the fluid to the feedback pressure surface of said main spool; and    a clutch port pressure feedback passage for coupling the pressure of fluid within the clutch port in said cage to said feedback pressure chamber, said clutch port pressure feedback passage including a feedback restriction orifice for restraining the rate at which fluid may flow between the clutch port in said cage and said feedback pressure chamber.    
     
     
         2 . The proportional pressure control valve of  claim 1  further comprising pressure spike suppression means for relieving any abnormally high pressure that occurs in the clutch port.  
     
     
         3 . The proportional pressure control valve of  claim 2  wherein said pressure spike suppression means includes a check valve for allowing fluid to flow from the clutch port to the tank port if an abnormally high pressure occurs in the clutch port.  
     
     
         4 . The proportional pressure control valve of  claim 3  wherein the check valve of the pressure spike suppression means is mounted within said main spool.  
     
     
         5 . The proportional pressure control valve of  claim 2  wherein the pressure spike suppression means further includes a spike suppression orifice between said control pressure chamber and said pressure spike suppression means for restraining the rate at which fluid may flow between said control pressure chamber and said pressure spike suppression means.  
     
     
         6 . The proportional pressure control valve of  claim 1  further comprising a pilot valve supply passage for supplying a control pressure flow of fluid from the pump port to said control pressure chamber; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means restraining the rate at which fluid flows from said pilot valve supply passage into said control pressure chamber, and thereby regulating the pressure of the fluid within said control pressure chamber.  
 
     
     
         7 . The proportional pressure control valve of  claim 6  further comprising a control pressure flow return passage for directing the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         8 . The proportional pressure control valve of  claim 1  further comprising a pilot valve supply passage for supplying a control pressure flow of fluid from the pump port to said control pressure chamber, said pilot valve supply passage including a control flow restriction orifice for restraining the flow rate of the control pressure flow of fluid; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means restraining the rate at which fluid flows from said control pressure chamber through the control pressure chamber outlet, and thereby regulating the pressure of the fluid within said control pressure chamber.  
 
     
     
         9 . The proportional pressure control valve of  claim 8  further comprising a control pressure flow return passage for conducting the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         10 . The proportional pressure control valve of  claim 1  further comprising a pilot valve supply passage for supplying a control pressure flow of fluid from the pump port to said control pressure chamber; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means both restraining the rate at which fluid flows from said pilot valve supply passage into said control pressure chamber and restraining the rate at which fluid flows from said control pressure chamber through the control pressure chamber outlet, and thereby regulating the pressure of the fluid within said control pressure chamber.  
 
     
     
         11 . The proportional pressure control valve of  claim 10  further comprising a control pressure flow return passage for directing the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         12 . The proportional pressure control valve of  claim 2  further comprising a pilot valve supply passage for supplying a control pressure flow of fluid from the pump port to said control pressure chamber; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means restraining the rate at which fluid flows from said pilot valve supply passage into said control pressure chamber, and thereby regulating the pressure of the fluid within said control pressure chamber.  
 
     
     
         13 . The proportional pressure control valve of  claim 12  further comprising a control pressure flow return passage for directing the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         14 . The proportional pressure control valve of  claim 2  further comprising a pilot valve supply passage for supplying a control pressure flow of fluid from the pump port to said control pressure chamber, said pilot valve supply passage including a control flow restriction orifice for restraining the flow rate of the control pressure flow of fluid; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means restraining the rate at which fluid flows from said control pressure chamber through the control pressure chamber outlet, and thereby regulating the pressure of the fluid within said control pressure chamber.  
 
     
     
         15 . The proportional pressure control valve of  claim 14  further comprising a control pressure flow return passage for directing the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         16 . The proportional pressure control valve of  claim 2  further comprising a pilot valve supply passage for supplying a control pressure flow of fluid from the pump port to said control pressure chamber; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means both restraining the rate at which fluid flows from said pilot valve supply passage into said control pressure chamber and restraining the rate at which fluid flows from said control pressure chamber through the control pressure chamber outlet, and thereby regulating the pressure of the fluid within said control pressure chamber.  
 
     
     
         17 . The proportional pressure control valve of  claim 16  further comprising a control pressure flow return passage for directing the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         18 . In a proportional pressure control valve that includes: 
 a hollow cage a wall pierced by a pump port that is adapted for receiving hydraulic fluid from a pump at a pressure established by the pump, the wall also being pierced by a clutch port that is adapted for supplying pressurized hydraulic fluid to a hydraulic actuator, and the wall also being pierced by a tank port that is adapted for supplying hydraulic fluid to a tank;    a main spool adapted to fit within the cage in which location the main spool is moveable relative to the cage for controlling a flow of hydraulic fluid passing between the clutch port in the cage and either the pump port or the tank port in the cage, the main spool including a control pressure surface to which pressure may be applied for urging the main spool to move within the cage to a position in which the main spool allows a flow of hydraulic fluid to pass between the pump port and the clutch port, the main spool also including a feedback pressure surface to which pressure may be applied for urging the main spool to move within the cage to a position in which the main spool allows a flow of hydraulic fluid to pass between the clutch port and the tank port;    a control pressure chamber located within the cage for receiving fluid under pressure and applying the pressure of the fluid to the control pressure surface of the main spool;    an electromagnetically operated pilot valve for supplying a regulated pressure of fluid to the control pressure chamber responsive to an electrical control signal;    a feedback pressure chamber located within the cage for receiving fluid at a pressure and coupling the pressure of the fluid to the feedback pressure surface of the main spool; and    a clutch port pressure feedback passage for coupling the pressure of hydraulic fluid within the clutch port in the cage to the feedback pressure chamber;    the improvement comprising: 
 a feedback restriction orifice located in the clutch port pressure feedback passage for restraining the rate at which fluid may flow between the clutch port in the cage and the feedback pressure chamber.  
   
     
     
         19 . The proportional pressure control valve of  claim 18  further comprising pressure spike suppression means for relieving any abnormally high pressure that occurs in the clutch port if a flow of hydraulic fluid through the clutch port is interrupted.  
     
     
         20 . The proportional pressure control valve of  claim 19  wherein said pressure spike suppression means includes a check valve for allowing hydraulic fluid to flow from the clutch port to the tank port if an abnormally high pressure occurs in the clutch port.  
     
     
         21 . The proportional pressure control valve of  claim 20  wherein the check valve of the pressure spike suppression means is mounted within said main spool.  
     
     
         22 . The proportional pressure control valve of  claim 19  wherein the pressure spike suppression means further includes a spike suppression orifice between said control pressure chamber and said pressure spike suppression means for restraining the rate at which fluid may flow between said control pressure chamber and said pressure spike suppression means.  
     
     
         23 . The proportional pressure control valve of  claim 19  further comprising a pilot valve supply passage for supplying a control pressure flow of hydraulic fluid from the pump port to said control pressure chamber; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means restraining the rate at which fluid flows from said pilot valve supply passage into said control pressure chamber, and thereby regulates the pressure of the fluid within said control pressure chamber.  
 
     
     
         24 . The proportional pressure control valve of  claim 23  further comprising a control pressure flow return passage for directing the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         25 . The proportional pressure control valve of  claim 19  further comprising a pilot valve supply passage for supplying a control pressure flow of hydraulic fluid from the pump port to said control pressure chamber, said pilot valve supply passage including a control flow restriction orifice for restraining the flow rate of the control pressure flow of hydraulic fluid; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means restraining the rate at which fluid flows from said control pressure chamber through the control pressure chamber outlet, and thereby regulates the pressure of the fluid within said control pressure chamber.  
 
     
     
         26 . The proportional pressure control valve of  claim 25  further comprising a control pressure flow return passage for conducting the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         27 . The proportional pressure control valve of  claim 19  further comprising a pilot valve supply passage for supplying a control pressure flow of hydraulic fluid from the pump port to said control pressure chamber; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 is said electromagnetically operated pilot valve means both restraining the rate at which fluid flows from said pilot valve supply passage into said control pressure chamber and restraining the rate at which fluid flows from said control pressure chamber through the control pressure chamber outlet, and thereby regulates the pressure of the fluid within said control pressure chamber.  
 
     
     
         28 . The proportional pressure control valve of  claim 27  further comprising a control pressure flow return passage for conducting the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         29 . The proportional pressure control valve of  claim 18  further comprising a pilot valve supply passage for supplying a control pressure flow of hydraulic fluid from the pump port to said control pressure chamber; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means restraining the rate at which fluid flows from said pilot valve supply passage into said control pressure chamber, and thereby regulates the pressure of the fluid within said control pressure chamber.  
 
     
     
         30 . The proportional pressure control valve of  claim 29  further comprising a control pressure flow return passage for conducting the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         31 . The proportional pressure control valve of  claim 18  further comprising a pilot valve supply passage for supplying a control pressure flow of hydraulic fluid from the pump port to said control pressure chamber, said pilot valve supply passage including a control flow restriction orifice for restraining the flow rate of the control pressure flow of hydraulic fluid; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means restraining the rate at which fluid flows from said control pressure chamber through the control pressure chamber outlet, and thereby regulates the pressure of the fluid within said control pressure chamber.  
 
     
     
         32 . The proportional pressure control valve of  claim 31  further comprising a control pressure flow return passage for conducting the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         33 . The proportional pressure control valve of  claim 18  further comprising a pilot valve supply passage for supplying a control pressure flow of hydraulic fluid from the pump port to said control pressure chamber; 
 said control pressure chamber having a control pressure chamber outlet through which fluid flows from said control pressure chamber;  
 said electromagnetically operated pilot valve means both restraining the rate at which fluid flows from said pilot valve supply passage into said control pressure chamber and restraining the rate at which fluid flows from said control pressure chamber through the control pressure chamber outlet, and thereby regulates the pressure of the fluid within said control pressure chamber.  
 
     
     
         34 . The proportional pressure control valve of  claim 33  further comprising a control pressure flow return passage for conducting the fluid that flows out of said control pressure chamber through the control pressure chamber outlet to the tank port of the valve.  
     
     
         35 . A method for operating a proportional pressure control valve comprising the steps of: 
 supplying pressurized fluid to a pump port formed through a wall of a hollow cage;    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 proportional pressure control valve, the control pressure chamber including a control pressure surface located on a main spool, the main spool positioned within the hollow cage and being moveable therein, said control pressure applied to the control pressure surface urging the main spool to move relative to the cage to a position in which the main spool allows a flow of 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 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 main spool, said feedback pressure applied to the feedback pressure surface urging the main spool to move relative to the cage to a position in which the main spool obstructs any flow of fluid between the pump port and the clutch port while simultaneously allowing a flow of fluid to pass between the clutch port and the tank port; and    restraining the rate at which fluid may flow between the clutch port in the cage and the feedback pressure chamber.    
     
     
         36 . The method for operating a proportional pressure control valve of  claim 35  further comprising the step of relieving any abnormally high pressure that occurs in the clutch port.  
     
     
         37 . The method for operating a proportional pressure control valve of  claim 36  wherein the abnormally high pressure is relieved by venting fluid from the clutch port to the tank port.  
     
     
         38 . The method for operating a proportional pressure control valve of  claim 35  wherein said regulated control pressure of fluid that is supplied to the control pressure chamber is generated by supplying a control pressure flow of fluid from the pump port to the control pressure chamber at a flow rate that is regulated in response to the electrical control signal applied to the proportional pressure control valve, and by allowing the fluid to flow out of the control pressure chamber at a restrained flow rate.  
     
     
         39 . The method for operating a proportional pressure control valve of  claim 35  wherein said regulated control pressure of fluid that is supplied to the control pressure chamber is generated by supplying a control pressure flow of fluid from the pump port to the control pressure chamber at a restrained flow rate, and by allowing the fluid to flow out of the control pressure chamber at a rate that is regulated in response to the electrical control signal applied to the proportional pressure control valve.  
     
     
         40 . The method for operating a proportional pressure control valve of  claim 35  wherein said regulated control pressure of fluid that is supplied to the control pressure chamber is generated by supplying a control pressure flow of fluid from the pump port to the control pressure chamber at a flow rate that is regulated in response to the electrical control signal applied to the proportional pressure control valve, and by allowing the fluid to flow out of the control pressure chamber at a rate that is also regulated in response to the electrical control signal.  
     
     
         41 . The method for operating a proportional pressure control valve of  claim 36  wherein said regulated control pressure of fluid that is supplied to the control pressure chamber is generated by supplying a control pressure flow of fluid from the pump port to the control pressure chamber at a flow rate that is regulated in response to the electrical control signal applied to the proportional pressure control valve, and by allowing the fluid to flow out of the control pressure chamber at a restrained flow rate.  
     
     
         42 . The method for operating a proportional pressure control valve of  claim 36  wherein said regulated control pressure of fluid that is supplied to the control pressure chamber is generated by supplying a control pressure flow of fluid from the pump port to the control pressure chamber at a restrained flow rate, and by allowing the fluid to flow out of the control pressure chamber at a rate that is regulated in response to the electrical control signal applied to the proportional pressure control valve.  
     
     
         43 . The method for operating a proportional pressure control valve of  claim 36  wherein said regulated control pressure of fluid that is supplied to the control pressure chamber is generated by supplying a control pressure flow of fluid from the pump port to the control pressure chamber at a flow rate that is regulated in response to the electrical control signal applied to the proportional pressure control valve, and by allowing the fluid to flow out of the control pressure chamber at a rate that is also regulated in response to the electrical control signal.