CLEANING CYCLE FOR CAPLESS REFUELING NECK

• US 20150211952A1
• Filed: 01/30/2014
• Published: 07/30/2015
• Est. Priority Date: 01/30/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Yang, Dennis Seung-Man, Dudar, Aed M., Ognjanovski, Rob Jr.
• Granted Patent: US 10,024,750 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system
• CPC Class Codes: G01M 3/025 Details with respect to the testing of engines or engine parts
• CPC Class Codes: G01M 3/32 for containers, e.g. radiators

Abstract

A method for a vehicle, comprising: following a refueling event, venting a capless refueling assembly to a fuel tank; and then executing an evaporative emissions leak test. In this way, residual fuel trapped in the capless refueling assembly may be removed. This, in turn will prevent a pressure build-up in the capless refueling assembly which could lead to the downstream door opening during a leak test, thereby confounding results.

Claims

1. A method for a vehicle, comprising:

following a refueling event, venting a capless refueling assembly to a fuel tank; and

then executing an evaporative emissions leak test.

2. The method of claim 1, where venting a capless refueling assembly to a fuel tank further comprises:

applying a vacuum greater than a threshold to the capless refueling assembly.

3. The method of claim 2, where applying a vacuum greater than a threshold to the capless refueling assembly further comprises:

applying a vacuum to the capless refueling assembly such that a downstream door of the capless refueling assembly opens; and

drawing fuel located upstream of the downstream door into the fuel tank.

4. The method of claim 3, where the threshold is based on a tension of a spring coupled to the downstream door of the capless refueling assembly.

5. The method of claim 4, where the threshold is −

20 inH₂O.

6. The method of claim 2, where applying a vacuum greater than a threshold to the capless refueling assembly further comprises:

opening a fuel tank isolation valve;

opening a canister vent valve; and

activating a vacuum pump within an evaporative leak check module coupled between a fuel vapor canister and atmosphere.

7. The method of claim 6, where executing an evaporative emissions leak test further comprises:

drawing a first vacuum on a reference orifice within the evaporative leak check module;

drawing a second vacuum on a fuel system; and

indicating a leak based on a comparison between the first vacuum and the second vacuum.

8. The method of claim 7, where drawing a first vacuum on the reference orifice further comprises:

placing a changeover valve within the evaporative leak check module in a first position;

closing the canister vent valve; and

activating the vacuum pump.

9. The method of claim 8, where drawing a second vacuum on the fuel system further comprises:

placing the changeover valve in a second position;

opening the canister vent valve;

opening the fuel tank isolation valve; and

activating the vacuum pump.

10. The method of claim 7, where indicating a leak based on the comparison between the first vacuum and the second vacuum further comprises:

indicating a leak if the first vacuum is greater than the second vacuum.

11. A system for a vehicle fuel system, comprising:

a fuel tank comprising a capless refueling assembly;

a fuel vapor canister coupled to the fuel tank via a fuel tank isolation valve;

a vacuum pump coupled to the fuel vapor canister via a canister vent valve;

a controller configured with instructions stored in non-transitory memory, that when executed cause the controller to;

following a refueling event, open the fuel tank isolation valve;

open the canister vent valve;

activate the vacuum pump to draw a vacuum on the fuel tank without checking for a leak; and

then

draw a vacuum on the fuel tank to check for a leak.

12. The system of claim 11, where drawing a vacuum on the fuel tank without checking for a leak further comprises:

drawing a vacuum greater than a threshold.

13. The system of claim 12, where the threshold is based on a minimum vacuum necessary to vent the capless refueling assembly.

14. The system of claim 13, where the threshold is −

20 inH₂O.

15. The system of claim 13, where the controller is further configured with instructions stored in non-transitory memory, that when executed cause the controller to:

determine whether the capless refueling assembly has been vented since a most recent refueling event; and

suspend a leak test if the capless refueling assembly has not been vented since the most recent refueling event.

16. The system of claim 11, where the vacuum pump is included in an evaporative leak check module.

17. A method for a vehicle, comprising:

following a refueling event, opening a fuel tank isolation valve;

activating an evaporative leak check module pump;

drawing a vacuum greater than a threshold without checking for a leak; and

then

drawing a vacuum to check for a leak.

18. The method of claim 17, where the threshold is based on a minimum vacuum necessary to vent a capless refueling assembly.

19. The method of claim 18, where the minimum vacuum necessary to vent the capless refueling assembly is based on the tension of a spring coupled to a downstream door of the capless refueling assembly.

20. The method of claim 17, where drawing a vacuum to check for a leak further comprises:

drawing a first vacuum on an reference orifice within an evaporative leak check module;

drawing a second vacuum on a fuel system; and

indicating a leak based on a comparison between the first vacuum and the second vacuum.