Evaporative solenoid control valve with enhanced durability features

Abstract

An evaporative solenoid valve assembly for use in a vehicle fuel system between a filtration canister and an intake manifold includes a plunger having a plunger body with central-bore and an elastomeric insert molded therein to define a stop cushion at the end of the insert proximal the valve stop and a valve tip at the end of the insert proximal the valve seat. The valve assembly may include a valve stop having a non-conducting insert received in an end proximal the plunger to reduce noise and wear as well as to improve magnetic flux path. Yet another improvement includes an enlarged pre-load spring disposed within the plunger to provide better spring force distribution and plunger to valve seat alignment.

1 . A valve assembly comprising: 
 a valve body defining an inlet, a controlled outlet and a passageway therebetween;    a valve stop and a valve seat supported within said valve body in axial alignment with said controlled outlet; and    a plunger reciprocable between the valve stop and the valve seat to open and close said controlled outlet, said plunger further including a central bore having an insert molded therein to define a stop-cushion at an end proximal the valve stop and a valve tip at an end proximal the valve seat.    
   
   
       2 . The valve assembly of  claim 1 , wherein the stop cushion is dome-shaped.  
   
   
       3 . The evaporative control valve assembly of  claim 1 , wherein the valve stop includes a plunger-impact surface formed of a non-conductive material.  
   
   
       4 . The evaporative control valve assembly of  claim 1 , wherein the valve stop includes a non-conductive insert received in an end proximal the plunger.  
   
   
       5 . The evaporative control valve assembly of  claim 1 , wherein said plunger includes a pocket formed in an end proximal the valve stop and a spring received with the pocket that urges the plunger toward the valve seat to close the passageway.  
   
   
       6 . The evaporative control valve assembly of  claim 4 , wherein the spring has an outer diameter at least 50% greater than the diameter of the pocket.  
   
   
       7 . The evaporative control valve assembly of  claim 1 , wherein a solenoid actuator is operable on said plunger to open and close said passageway.  
   
   
       8 . A method of manufacturing a plunger reciprocably moveable within a valve assembly between a valve stop and a valve seat, the method comprising: 
 providing a conductive elongate plunger body having a central bore formed therein;    molding an insert within the plunger body to define a stop-cushion at an end proximal the valve stop and a valve tip proximal an end proximal the valve seat.    
   
   
       9 . A plunger mnufactured according to the method of  claim 8 , comprising: 
 a conductive elongate plunger body having a central bore formed therein; and    an insert molded within the plunger body to define a stop-cushion at an end proximal the valve stop and a valve tip proximal an end proximal the valve seat.