Purge valve for on board fuel vapor recovery systems
First Claim
1. A purge valve for controlling the flow of vapor from a vapor source to a vacuum source, said valve comprising an elongate generally tubular main housing having a first chamber opening at one axial end of said housing and a second chamber opening at the opposite axial end of said housing, means defining an inlet passage adapted to be connected to a vapor source extending into said housing and an outlet passage adapted to be connected to a vacuum source extending into said housing, means defining a first axial passage extending from said inlet passage to an opening at the inner end of said first chamber, means defining a second axial passage extending from an outlet opening in said second chamber to said outlet passage, means defining a third passage placing said first and second chambers in constant communication with each other, first and second end cap means sealingly mounted at the opposite ends of said main housing to respectively seal said first and second chambers from atmopshere, first solenoid controlled valve means in said housing operable to selectively block or accommodate flow from said first axial passage into said first chamber, and second pressure responsive valve means operable to selectively block or accommodate flow from said second chamber into said second axial passage in response to variations in pressure in said outlet passage.
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Accused Products
Abstract
A purge valve for a vehicle mounted fuel vapor recovery system is made up of a main housing and two end caps which snap fit together to seal and mount a computer controlled solenoid valve and a diaphragm controlled regulating valve. The housing is designed so that the required valve seats are integrally molded in the housing as are the various internal passages and chambers. A compression post formed on one end cap seats the solenoid assembly firmly against an abutment surface on the housing.
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Citations
10 Claims
- 1. A purge valve for controlling the flow of vapor from a vapor source to a vacuum source, said valve comprising an elongate generally tubular main housing having a first chamber opening at one axial end of said housing and a second chamber opening at the opposite axial end of said housing, means defining an inlet passage adapted to be connected to a vapor source extending into said housing and an outlet passage adapted to be connected to a vacuum source extending into said housing, means defining a first axial passage extending from said inlet passage to an opening at the inner end of said first chamber, means defining a second axial passage extending from an outlet opening in said second chamber to said outlet passage, means defining a third passage placing said first and second chambers in constant communication with each other, first and second end cap means sealingly mounted at the opposite ends of said main housing to respectively seal said first and second chambers from atmopshere, first solenoid controlled valve means in said housing operable to selectively block or accommodate flow from said first axial passage into said first chamber, and second pressure responsive valve means operable to selectively block or accommodate flow from said second chamber into said second axial passage in response to variations in pressure in said outlet passage.
- 5. A purge valve for controlling the flow of vapor from a vapor source to a vacuum source, said valve comprising a one piece molded vertically elongate main housing having a first bore extending upwardly into said housing from its lower end to a horizontal downwardly facing shoulder, a second bore coaxial with and of a diameter less than said first bore extending upwardly into said housing from said shoulder to an upper end, and a third bore coaxial with and of a diameter less than said second bore extending upwardly into said housing from said upper end of said second bore, means defining an inlet passage adapted to be connected to said vapor source and intersecting said third bore, a downwardly facing annular valve seat on the upper end of said second bore coaxial with said third bore, a generally cylindrical solenoid assembly received within said first bore and having one end engaged with said shoulder, said solenoid assembly including a coil and an armature projecting coaxially upwardly from said one end of said assembly, a valve head on the upper end of said armature, an end cap mounted on the lower end of said housing sealingly closing the lower end of said first bore, integral compression means on said end cap compressively engaged with the lower end of said solenoid assembly pressing said assembly upwardly against said shoulder, spring means in said solenoid assembly biassing said armature upwardly to sealingly engage said valve head with said valve seat to block fluid communication between said second and third bores, electrical connector means in said end cap for connecting said coil to an electric power source, said coil being operable when energized to withdraw said armature downwardly to disengage said valve head from said valve seat to accommodate fluid flow from said third bore into said second bore, means on said housing defining an outlet passage adapted to be connected to a vacuum source, and second valve means in said housing for controlling flow of fluid from said third bore into said outlet passage in accordance with pressure variations in said outlet passage.
- 8. In a vehicle driven by an internal combustion engine, the combination of plurality of fuel system-related components including fuel induction means for the engine, a plurality of separate means each sensing and generating an output signal representative of the instantaneous value of an engine operating parameter, an on-board computer receiving one or more of said sensor output signals and controlling certain engine functions in accordance with certain of said parameters, a fuel storage tank, a fuel vapor canister for storing therein fuel vapors from said tank and purge means for subsequently purging said vapors from said canister to said fuel induction means at a controlled rate for combustion in said engine, said purge means comprising a valve housing having a vapor inlet connected to said canister, a vapor outlet connected to said fuel induction means, and vapor flow passage means extending through said housing from said inlet into an internal chamber and from said chamber to said outlet, first normally closed solenoid actuated valve means in flow passage means between said inlet and said chamber operable upon actuation of its solenoid to accommodate flow of vapor from said inlet into said chamber, and second normally open pressure differential responsive valve means in said flow passage means moveable to a closed position in response to a predetermined reduction in a pressure applied to said outlet by said induction means for controlling the rate of flow of vapor from said chamber into said outlet.
Specification