Tank leakage diagnosis having a fuel tank as a pressure store

Patent metadata

Field	Value
Publication number	US-9983090-B2
Application number	US-201415032107-A
Country	US
Kind code	B2
Filing date	Sep 25, 2014
Priority date	Oct 28, 2013
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

The invention relates to a system ( 1 ) and to a corresponding method for tank leakage diagnosis. The system ( 1 ) comprises a fuel tank ( 3 ), a pressure source ( 5, 9 ), and a pressure sensor ( 7 ). The pressure source ( 5, 9 ) is configured to increase the pressure in the fuel tank ( 3 ). The pressure sensor ( 7 ) is configured to detect the pressure progression at the fuel tank ( 3 ). The system ( 1 ) is configured to seal the fuel tank ( 3 ) in a gas-tight manner such that the fuel tank ( 3 ) can be used as a pressure store. Furthermore, the system ( 1 ) is configured to conclude, independently of a current operation of the pressure source ( 5, 9 ) based on the determined pressure progression at the fuel tank ( 3 ), that a leak is present.

First claim

What is claimed is:

1. A system for tank leakage diagnosis, the system comprising:
a fuel tank;
a pressure source, which is configured to increase a pressure in the fuel tank; and
a pressure sensor, which is configured to detect a pressure progression at the fuel tank,
wherein the system is configured to seal the fuel tank in a gas-tight manner such that the fuel tank can be used as a pressure store, wherein
the system is configured to conclude, independently of a current operation of the pressure source, based on a detected pressure progression at the fuel tank, that a leak is present,
wherein the fuel tank is configured to be connected to the pressure source via a first line,
wherein a first electric valve is provided on the first line,
wherein the system further comprises an adsorption filter,
wherein the fuel tank is configured to be connected to the adsorption filter via a second line,
wherein a second electric valve is provided on the second line, and
wherein, when detecting a pressure progression at the fuel tank, the first valve and the second valve seal the fuel tank in a gas-tight manner.

2. The system according to claim 1 , wherein the pressure source is a turbocharger.

3. The system according to claim 1 ,
wherein the adsorption filter is configured to be connected to a surrounding environment via a fourth line;
wherein a third electric valve is provided on the fourth line;
wherein the adsorption filter is configured to be connected via a fifth line to an intake manifold in order to be flushed with fresh air;
wherein a fourth electric valve is provided on the fifth line; and
wherein, when detecting a pressure progression at the adsorption filter, the second electric valve is open, whereas the first electric valve, the third electric valve and the fourth electric valve are closed in a gas-tight manner.

4. The system according to claim 1 ,
wherein the fuel tank is configured to be connected to the adsorption filter via a third line;
wherein a first pressure relief valve is provided on the third line; and
wherein the first pressure relief valve is designed to open in the direction of the adsorption filter as soon as a predefinable pressure threshold value has been exceeded in the fuel tank.

5. The system according to claim 1 , further comprising:
an adsorption filter;
wherein the pressure source is configured to be connected to the adsorption filter via a first line;
wherein a first electric valve is provided on the first line;
wherein the fuel tank is configured to be connected to the adsorption filter via a second line;
wherein a second electric valve is provided on the second line; and
wherein, when detecting a pressure progression at the fuel tank, the second valve seals the fuel tank in a gas-tight manner.

6. The system according to claim 5 ,
wherein the adsorption filter is configured to be connected to a surrounding environment via a fourth line;
wherein a directional control valve is provided between the first line, the fourth line and the adsorption filter;
wherein the directional control valve is configured in a first position to connect the adsorption filter to the first line; and
wherein the directional control valve is configured in a second position to connect the adsorption filter to the fourth line.

7. The system according to claim 6 ,
wherein the adsorption filter is configured to be connected to an intake manifold via a fifth line in order to be flushed with fresh air;
wherein a fourth electric valve is provided on the fifth line; and
wherein, when detecting a pressure progression at the adsorption filter, the second electric valve is open, whereas the first electric valve and the fourth electric valve are closed in a gas-tight manner and the directional control valve is disposed in the first position.

8. The system according to claim 7 ,
wherein the adsorption filter is configured to be connected to the intake manifold via a sixth line in order to be flushed with fresh air;
wherein a second pressure relief valve is provided on the sixth line; and
wherein the second pressure relief valve is designed to open in the direction of the intake manifold as soon as a predefinable pressure threshold value at the adsorption filter has been exceeded.

9. A method for carrying out a tank leakage diagnosis on a system according to claim 1 , the method comprising the following steps:
connecting the fuel tank to the pressure source;
increasing the pressure in the fuel tank by means of the pressure source;
sealing the fuel tank in a gas-tight manner;
using the fuel tank as a pressure store; and
detecting a presence of a leak independently of the current operation of the pressure source and based on a detected pressure progression at the fuel tank.

10. A system for tank leakage diagnosis, the system comprising:
a fuel tank;
a pressure source, which is configured to increase a pressure in the fuel tank; a pressure sensor, which is configured to detect a pressure progression at the fuel tank; and
an adsorption filter,
wherein the pressure source is configured to be connected to the adsorption filter via a first line,
wherein a first electric valve is provided on the first line,
wherein the fuel tank is configured to be connected to the adsorption filter via a second line,
wherein a second electric valve is provided on the second line,
wherein, when detecting a pressure progression at the fuel tank, the second valve seals the fuel tank in a gas-tight manner,
wherein the fuel tank is configured to be connected to the adsorption filter via a third line,
wherein a first pressure relief valve is provided on the third line, and
wherein the first pressure relief valve is designed to open in the direction of the adsorption filter as soon as a predefinable pressure threshold value has been exceeded in the fuel tank.

11. A method for carrying out a leakage diagnosis on a portion of a fuel system, the method comprising the following steps:
communicating a fuel tank with a pressure source;
increasing a pressure in the fuel tank by means of the pressure source;
sealing the fuel tank in a gas-tight manner;
detecting a presence of a leak independently of a current operation of the pressure source and based on a determined pressure progression at the fuel tank;
after the detecting, opening a valve connecting the fuel tank with an adsorption filter; and
after the opening, detecting a presence of a leak independently of a current operation of the pressure source and based on a determined pressure progression at either 1) a space including both the fuel tank and the adsorption filter or 2) the adsorption filter only.

12. The method of claim 11 , wherein detecting a presence of a leak independently of the current operation of the pressure source and based on a determined pressure progression at a space including both the fuel tank and the adsorption filter includes detecting with a pressure sensor positioned in the fuel tank.

13. The method of claim 11 , wherein detecting a presence of a leak independently of the current operation of the pressure source and based on a determined pressure progression at a space including both the fuel tank and the adsorption filter includes detecting with a pressure sensor positioned in the adsorption filter.

Assignees

• Bosch Gmbh Robert

Inventors

• Klee Peter
• Posselt Andreas
• Lorenz Marko
• Gutscher Andreas
• Kurz Roland
• Wieczorek Thomas
• Herges Thomas
• Koenig Joerg
• Guenther Florian
• Hoegl Johannes

Classifications

• F02M25/0836

  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 title

• Y02T10/40

  Engine management systems · CPC title

• F02D41/0007

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D2041/225

  Leakage detection · CPC title

• F02M25/0809

  Judging failure of purge control system · CPC title