Fuel system for a motor vehicle

Patent metadata

Field	Value
Publication number	US-2016115907-A1
Application number	US-201514918913-A
Country	US
Kind code	A1
Filing date	Oct 21, 2015
Priority date	Oct 22, 2014
Publication date	Apr 28, 2016
Grant date	—

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.

First claim

What is claimed is:

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.

Assignees

• Audi Ag

Inventors

• Hagen Harald

Classifications

• B60K2015/03585

  by gas pressure · CPC title

• B60K2015/03576

  Venting during filling the reservoir · CPC title

• B60K2015/03538

  the venting tube being connected with the filler tube · CPC title

• B60K2015/03514

  with vapor recovery means · CPC title

• B60K2015/03566

  comprising means for stopping the venting of fuel vapor, e.g. during refuelling or engine stop · CPC title