FUEL SYSTEM FOR A MOTOR VEHICLE

• US 20160115907A1
• Filed: 10/21/2015
• Published: 04/28/2016
• Est. Priority Date: 10/22/2014
• Status: Active Grant

• Current Assignee: Audi AG (Volkswagen AG)
• Original Assignee: Audi AG (Volkswagen AG)
• Inventors: Hagen, Harald
• Granted Patent: US 10,549,628 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60K 15/03519 Valve arrangements in the vent line
• CPC Class Codes: B60K 2015/03514 with vapor recovery means
• CPC Class Codes: B60K 2015/03538 the venting tube being connected with the filler tube
• CPC Class Codes: B60K 2015/03566 comprising means for stopping the venting of fuel vapor, e.g. during refueling or engine stop
• CPC Class Codes: B60K 2015/03576 Venting during filling the reservoir
• CPC Class Codes: B60K 2015/03585 by gas pressure
• CPC Class Codes: F02M 25/08 adding fuel vapours drawn from engine fuel reservoir electrical control of purge system F02D41/003

Abstract

A fuel system for a motor vehicle includes a fuel tank, a filling tube closable by a tank cover; a pressure sensor for measuring a pressure in the fuel tank; an activated carbon filter, a tank isolation valve arranged between the fuel tank and the activated carbon filter, and a control for opening and closing the tank isolation valve, wherein the control opens the tank isolation valve in response to receiving input indicating an intent to refuel and closes the opened tank isolation valve again when the pressure in the fuel tank measured by the pressure sensor falls below a predetermined first pressure threshold value, wherein the control subsequent to the closing of the tank isolation valve opening the closed tank isolation valve again when the pressure in the fuel tank measured by the pressure sensor exceeds the predetermined first pressure threshold value and/or exceeds a predetermined second pressure threshold value, which is higher than the predetermined first pressure threshold value.

Claims

1. A fuel system for a motor vehicle, said fuel system comprising:

a fuel tank configured as pressure tank, a filling tube closable by a tank cover;

a pressure sensor for measuring a pressure in the fuel tank;

an activated carbon filter;

a tank isolation valve arranged between the fuel tank and the activated carbon filter; and

a control for opening and closing the tank isolation valve, said control opening the tank isolation valve in response to receiving input indicating an intent to refuel and closing the opened tank isolation valve again when the pressure in the fuel tank measured by the pressure sensor falls below a predetermined first pressure threshold value, said control subsequent to the closing of the tank isolation valve opening the closed tank isolation valve again when the pressure in the fuel tank measured by the pressure sensor exceeds the predetermined first pressure threshold value and/or exceeds a predetermined second pressure threshold value, said predetermined second pressure threshold value being higher than the predetermined first pressure threshold value.

2. The fuel system of claim 1, wherein the predetermined first pressure threshold value is about 25 mbar.

3. The fuel system of claim 1, wherein the control opens the closed tank isolation valve again when the pressure in the fuel tank exceeds the predetermined second pressure threshold value.

4. The fuel system of claim 1, wherein the predetermined second pressure threshold value is about 50 mbar.

5. The fuel system of claim 1, wherein the control repeatedly closes and opens the tank isolation valve when the pressure in the tank falls below the predetermined first pressure threshold value or exceeds the predetermined second pressure threshold value.

6. The fuel system of claim 1, wherein the filling tube communicates with a head or gas space of the fuel tank through a refueling venting line.

7. The fuel system of claim 1, wherein the control keeps the tank isolation valve closed during the refueling.

8. The fuel system of claim 1, wherein the predetermined first pressure threshold value is about 5 mbar.

9. The fuel system of claim 1, wherein the control opens the tank isolation valve again when the pressure in the fuel tank exceeds the first pressure threshold value.

10. The fuel system of claim 9, wherein the control actuates the tank isolation valve again for opening when the pressure in the fuel tank exceeds the predetermined second pressure threshold value.

11. The fuel system of claim 1, wherein the control holds the tank isolation valve open during the refueling.

12. The fuel system of claim 1, wherein the control analyzes a gradient of the pressure increase from the predetermined first pressure threshold value to the predetermined second pressure threshold value.