Compartmental evaporative canister and pressure control valve assembly

• US 5,148,793 A
• Filed: 05/20/1991
• Issued: 09/22/1992
• Est. Priority Date: 05/20/1991
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Reddy, S. Raghuma
• Primary Examiner(s): MILLER, CARL STUART
• Application Number:
  US07/702,859
• Time in Patent Office: 491 Days
• Field of Search: 123/520, 123/521, 123/518, 123/516, 123/519, 123/198 D, 55/387, 55/316
• US Class Current: 123/520
• CPC Class Codes: F02M 2025/0845 Electromagnetic valves
• CPC Class Codes: F02M 25/0854 Details of the absorption canister

Abstract

A fuel vapor storage canister to prevent breakthrough evaporative emission loss and facilitate purging by concentrating the fuel vapor close to the vent to the engine. The canister is divided into two compartments which communicate through a connective means that only allows vapor into the second compartment when a control valve, located in the connective means, opens at a threshold pressure.

Claims

1. A fuel vapor storage canister assembly for an engine fuel system, comprising:

a main vapor storage compartment,

an auxiliary vapor storage compartment,

a vapor inlet/outlet aperture to the main compartment, and adapted for connection to a fuel tank and a source of engine vacuum,

an atmospheric vent opening to the auxiliary compartment,

a connective means between the main compartment and the auxiliary compartment, and

a control valve, comprising a diaphragm and spring, in the connective means between said main compartment and the auxiliary compartment, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, and is responsive to pressure in the main compartment to permit the diaphragm to unseat from against the connective means and allow the connective means to be open when the pressure in the main compartment reaches a selected level, whereby substantially all vapor is collected in the main compartment.

2. A fuel vapor storage canister assembly for an engine fuel system, comprising:

a generally elongated, adsorbent filled housing having a main compartment and an auxiliary compartment,

a vapor inlet/outlet aperture to the main compartment, and adapted for connection to a fuel tank and a source of engine vacuum,

an atmospheric vent opening to said auxiliary compartment,

a connective means between the main compartment and the auxiliary compartment, and

a control valve, comprising a diaphragm and spring, in the connective means between said main compartment and the auxiliary compartment, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, and is responsive to pressure in the main compartment to permit the diaphragm to unseat from against the connective means and allow the connective means to be open when the pressure in the main compartment reaches a selected level, whereby substantially all vapor is collected in the main compartment.

3. A fuel vapor storage canister assembly for an engine fuel system, comprising:

a generally elongated, adsorbent filled housing having a volume partitioned either vertically or horizontally into a plurality of separate chambers that communicate with each other in succession to compose a main compartment,

an adsorbent filled auxiliary compartment within the housing where the auxiliary volume is smaller than the main volume,

a vapor inlet/outlet aperture to the first chamber of the main compartment, and adapted for connection to a fuel tank and a source of engine vacuum,

an atmospheric vent opening to auxiliary compartment,

a connective means between the last chamber of the main compartment and the auxiliary compartment, and

a control valve, comprising a diaphragm and spring, in the connective means between said main compartment and the auxiliary compartment, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, and is responsive to pressure in the main compartment to permit the diaphragm to unseat from against the connective means and allow the connective means to be open when the pressure in the main compartment reaches a selected level, whereby substantially all vapor is collected in the main compartment.

4. A fuel vapor storage canister assembly for an engine fuel system, comprising:

a main adsorbent filled compartment comprising of multiple separate chambers that communicate with each other in succession to compose the main compartment,

an adsorbent filled auxiliary compartment where the auxiliary volume is smaller than the main volume,

a vapor inlet/outlet aperture to the first chamber of the main compartment,

an atmospheric vent opening to auxiliary compartment,

a connective means between the last chamber of the main compartment and the auxiliary compartment, and

a control valve, comprising a diaphragm, and spring, in the connective means between said main compartment and auxiliary compartment, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, and is responsive to pressure in the main compartment to permit the diaphragm to unseat from against the connective means and allow the connective means to be open when the pressure in the main compartment reaches a selected level, whereby substantially all vapor is collected in the main compartment.

5. A fuel vapor storage canister assembly for an engine fuel system, comprising:

a main vapor storage compartment,

an auxiliary vapor storage compartment,

a vapor inlet/outlet aperture to the main compartment, and adapted for connection to a fuel tank and a source of engine vacuum,

an atmospheric vent opening to the auxiliary compartment,

a connective means between the main compartment and the auxiliary compartment,

a control valve, comprising a diaphragm, spring, and vacuum orifice, in the connective means between said main compartment and the auxiliary compartment, and

a vacuum line connectable to the induction system of the engine and joining the control valve at the vacuum orifice, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, thereby keeping the auxiliary compartment'"'"'s adsorbent material clean from hydrocarbon vapors by concentrating said vapors closer to the inlet/outlet aperture, and

thereby improving purging capabilities during which engine vacuum acts upon the spring in the control valve to unseat the diaphragm which opens the control valve and draws in air through the atmospheric vent which successively flows into the auxiliary compartment, through the control valve, and into the main compartment to retrieve the hydrocarbon vapors and return them to the engine.

6. A fuel vapor storage canister assembly for an engine fuel system, comprising:

a generally elongated, adsorbent filled housing having a main compartment and an auxiliary compartment,

a vapor inlet/outlet aperture to the main compartment, and adapted for connection to a fuel tank and a source of engine vacuum,

an atomspheric vent opening to said auxiliary compartment,

a connective means between the main compartment and the auxiliary compartment,

a control valve, comprising a diaphragm, spring, and a vacuum orifice, in the connective means between said main compartment and auxiliary compartment, and

a vacuum line connectable to the induction system of the engine and joining the control valve at the vacuum orifice, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, thereby keeping the auxiliary compartment'"'"'s adsorbent material clean from hydrocarbon vapors by concentrating said vapors closer to the inlet/outlet aperture, and

thereby improving purging capabilities during which engine vacuum acts upon the spring in the control valve to unseat the diaphragm which opens the control valve and draws in air through the atmospheric vent which successively flows into the auxiliary compartment, through the control valve, and into the main compartment to retrieve the hydrocarbon vapors and return them to the engine.

7. A fuel vapor storage canister assembly for an engine fuel system, comprising:

a generally elongated, adsorbent filled housing having a total volume partitioned either vertically or horizontally into a plurality of separate chambers that communicate with each other in succession to compose a main compartment,

an adsorbent filled auxiliary compartment within the housing where the auxiliary volume is smaller than the main volume,

a vapor inlet/outlet aperture to the first chamber of the main compartment, and adapted for connection to a fuel tank and a source of engine vacuum,

an atmospheric vent opening to auxiliary compartment,

a connective means between the last chamber of the main compartment and the auxiliary compartment,

a control valve, comprising a diaphragm, spring, and vacuum orifice, in the connective means between said main compartment and auxiliary compartment, and

a vacuum line connectable to the induction system of the engine and joining the control valve at the vacuum orifice, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, thereby keeping the auxiliary compartment'"'"'s adsorbent material clean from hydrocarbon vapors by concentrating said vapors closer to the inlet/outlet aperture, and

thereby improving purging capabilities during which engine vacuum acts upon the spring in the control valve to unseat the diaphragm which opens the control valve and draws in air through the atmospheric vent which successively flows into the auxiliary compartment, through the control valve, and into the main compartment to retrieve the hydrocarbon vapors and return them to the engine.

8. A fuel vapor storage assembly for an engine fuel system, comprising:

a main adsorbent filled compartment having a volume partitioned either vertically or horizontally into a plurality of separate chambers that communicate with each other in succession to compose a main compartment,

an adsorbent filled auxiliary compartment where the auxiliary volume is smaller than the main volume,

a vapor inlet/outlet aperture to the first chamber of the main compartment, and adapted for connection to a fuel tank and a source of engine vacuum,

an atmospheric vent opening to auxiliary compartment,

a connective means between the last chamber of the main compartment and the auxiliary compartment,

a control valve, comprising a diaphragm, spring, and vacuum orifice, in the connective means between said main compartment and auxiliary compartment, and

a vacuum line connectable to the induction system of the engine and joining the control valve at the vacuum orifice, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, thereby keeping the auxiliary compartment'"'"'s adsorbent material clean from hydrocarbon vapors by concentrating said vapors closer to the inlet/outlet aperture, and

thereby improving purging capabilities during which engine vacuum acts upon the spring in the control valve to unseat the diaphragm which opens the control valve and draws in air through the atmospheric vent which successively flows into the auxiliary compartment, through the control valve, and into the main compartment to retrieve the hydrocarbon vapors and return them to the engine.

9. A fuel vapor storage canister assembly for an engine fuel system, comprising:

a generally elongated, adsorbent filled housing having a volume partitioned either vertically or horizontally into a plurality of separate chambers that communicate with each other in succession to compose a main compartment,

an adsorbent filled auxiliary compartment within the housing where the auxiliary volume is smaller than the main volume,

a vapor inlet/outlet aperture to the first chamber of the main compartment, and adapted for connection to a fuel tank and a source of engine vacuum,

an atmospheric vent opening to the auxiliary compartment,

a connective means between the last chamber of the main compartment and the auxiliary compartment,

a control valve, comprising a diaphragm, spring, and vacuum orifice, in the connective means between said main compartment and auxiliary compartment, and

a vacuum line connectable to the induction system of the engine and joining the control valve at the vacuum orifice, and

wherein said control valve is biased to prevent vapors from flowing from the main compartment into said auxiliary compartment, and is responsive to pressure in the main compartment to permit the diaphragm to unseat from against the connective means and allow the connective means to be open when the pressure in the main compartment reaches a selected level, thereby keeping the auxiliary compartment'"'"'s adsorbent material clean from hydrocarbon vapors by concentrating said vapors closer to the inlet/outlet aperture, and

thereby improving purging capabilities during which engine vacuum acts upon the spring in the control valve to unseat the diaphragm which opens the control valve and draws in air through the atmospheric vent which successively flows into the auxiliary compartment, through the control valve, and into the main compartment to retrieve the hydrocarbon vapors and return them to the engine.