Method for operating a fuel system, and fuel system

• US 9,163,591 B2
• Filed: 12/16/2011
• Issued: 10/20/2015
• Est. Priority Date: 12/21/2010
• Status: Active Grant

• Current Assignee: Audi AG (Volkswagen AG)
• Original Assignee: Audi AG (Volkswagen AG)
• Inventors: Hagen, Harald
• Primary Examiner(s): SOLIS, ERICK R
• Application Number:
  US13/328,333
• Publication Number:
  US 20120180760A1
• Time in Patent Office: 1,404 Days
• Field of Search: 123518-520
• US Class Current: 1/1
• CPC Class Codes: B60K 15/03519 Valve arrangements in the vent line
• CPC Class Codes: B60K 2015/0319 with electronic systems, e.g. for controlling fuelling or venting
• CPC Class Codes: B60K 2015/0321 characterised by special sensors, the mounting thereof
• CPC Class Codes: B60K 2015/03289 Float valves; Floats therefor
• CPC Class Codes: B60K 2015/03296 Pressure regulating valves
• CPC Class Codes: B60K 2015/03388 in case of a roll over of the vehicle
• CPC Class Codes: B60K 2015/03514 with vapor recovery means
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 2200/0606 Fuel temperature
• CPC Class Codes: F02D 41/0032 Controlling the purging of the canister as a function of the engine operating conditions
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02M 25/0836 Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
• CPC Class Codes: F02M 25/089 Layout of the fuel vapour installation

Abstract

In a method for operating a fuel system of an internal combustion engine, the fuel system has a fuel tank and a ventilation device for ventilating the fuel tank which has at least one ventilation valve. In a first operating mode the ventilation valve is adjusted for ventilating the fuel tank based exclusively on a temperature and/or the ventilation occurs over a defined period of time when the internal combustion engine is deactivated. The invention further relates to a fuel system of an internal combustion engine.

Claims

1. A method for operating a fuel system of an internal combustion engine, comprising adjusting a ventilation valve of a ventilation device of a fuel system for ventilating a fuel tank in a first operating mode exclusively as a function of a temperature when the internal combustion engine is deactivated.

2. The method of claim 1, further comprising ventilating the fuel tank over a defined period of time when the internal combustion engine is deactivated.

3. The method of claim 1, wherein the ventilation valve is adjusted for ventilating the fuel tank when the temperature falls below or exceeds a threshold temperature.

4. The method of claim 2, wherein the defined period of time is selected so that an internal fuel tank pressure is reduced by a defined pressure differential.

5. The method of claim 1, wherein the temperature is a member selected from the group consisting of an ambient temperature, an internal fuel tank temperature, a fuel temperature, a ventilation valve temperature, a line temperature or a separation device temperature.

6. The method of claim 1, wherein the ventilation valve is integrated in a member selected from the group consisting of an aeration valve which switches in dependence on the fuel tank fill level, a safety valve which is assigned to the fuel tank, a tank lid of the fuel tank, a separation device, the fuel tank and an overflow valve or fluidly arranged upstream of, downstream of, or in parallel to the member.

7. The method of claim 1, wherein the ventilation valve has at least one temperature deforming element.

8. The method of claim 7, wherein the temperature deforming element is a temperature expansion element.

9. The method of claim 7, wherein the temperature deforming element is a wax expansion element or a bimetal element.

10. The method of claim 7, wherein the temperature deforming element is a bimetal element.

11. The method of claim 1, further comprising adjusting the ventilation valve in a second operating mode exclusively as a function of a pressure.

12. The method of claim 11, further comprising ventilating the fuel tank over a defined period of time when the internal combustion engine is deactivated.

13. The method of claim 11, wherein the ventilation valve is adjusted for ventilating the fuel tank when the temperature falls below or exceeds a threshold temperature.

14. The method of claim 12, wherein the defined period of time is selected so that an internal fuel tank pressure is reduced by a defined pressure differential.

15. The method of claim 11, wherein the ventilation valve is integrated in a member selected from the group consisting of an aeration valve which switches in dependence on the fuel tank fill level, a safety valve which is assigned to the fuel tank, a tank lid of the fuel tank, a separation device, the fuel tank and an overflow valve or fluidly arranged upstream of, downstream of, or in parallel to the member.

16. The method of claim 11, wherein the ventilation valve has at least one temperature deforming element.

17. The method of claim 16, wherein the temperature deforming element is a temperature expansion element.

18. The method of claim 16, wherein the temperature deforming element is a wax expansion element or a bimetal element.

19. The method of claim 16, wherein the temperature deforming element is a bimetal element.

20. The method of claim 11, further comprising adjusting the ventilation valve in a third operating mode as a function of a temperature and a pressure.

21. The method of claim 20, further comprising ventilating the fuel tank over a defined period of time when the internal combustion engine is deactivated.

22. The method of claim 20, wherein the ventilation valve is adjusted for ventilating the fuel tank when the temperature falls below or exceeds a threshold temperature.

23. The method of claim 21, wherein the defined period of time is selected so that an internal fuel tank pressure is reduced by a defined pressure differential.

24. The method of claim 20, wherein the temperature is a member selected from the group consisting of an ambient temperature, an internal fuel tank temperature, a fuel temperature, a ventilation valve temperature, a line temperature or a separation device temperature.

25. The method of claim 20, wherein the fuel system further comprises a control device and a further control device, wherein at least when the internal combustion engine is deactivated, the control device analyzes the temperature and correspondingly adjusts the ventilation valve, and wherein the control device or the further control device analyzes at least the pressure and correspondingly adjusts the ventilation valve, only when the internal combustion engine is deactivated.

26. The method of claim 20, wherein the ventilation valve is integrated in a member selected from the group consisting of an aeration valve which switches in dependence on the fuel tank fill level, a safety valve which is assigned to the fuel tank, a tank lid of the fuel tank, a separation device, the fuel tank and an overflow valve or fluidly arranged upstream of, downstream of, or in parallel to the member.

27. The method of claim 20, wherein the ventilation valve has at least one temperature deforming element.

28. The method of claim 27, wherein the temperature deforming element is a temperature expansion element.

29. The method of claim 27, wherein the temperature deforming element is a wax expansion element or a bimetal element.

30. The method of claim 27, wherein the temperature deforming element is a bimetal element.

31. A fuel system of an internal combustion engine, comprising:

a fuel tank; and

a ventilation device for ventilating the fuel tank, said ventilation device having at least one ventilation valve, wherein the fuel system is configured for adjusting the ventilation valve for ventilation of the fuel tank in a first operating mode exclusively as a function of a temperature, wherein the ventilation occurs over a defined period of time when the internal combustion engine is deactivated.

32. The fuel system of claim 31, wherein the fuel system is configured for adjusting the ventilation valve for ventilation of the fuel tank in a second operating mode exclusively as a function of a pressure.

33. The fuel system of claim 31, wherein the fuel system is further configured for adjusting the ventilation valve for ventilation of the fuel tank in a third operating mode exclusively as a function of pressure.

34. the fuel system of claim 31, wherein the fuel system is further configured for adjusting the ventilation valve for ventilation of the fuel tank in a third operating mode exclusively as a function of a temperature and a pressure.

35. A method for operating a fuel system of an internal combustion engine, comprising adjusting at least one ventilation valve of a ventilation device of the fuel system for ventilating a fuel tank in one of three ways, a first way corresponding to a first operating mode, exclusively as a function of a temperature, a second way corresponding to a second operating mode, exclusively as a function of a pressure, a third way, corresponding to a third operating mode, as a function of the temperature and the pressure, wherein said ventilating takes place over a defined period of time when the internal combustion engine is deactivated.