Method and device for diagnosing tank leaks using a reference measuring method

• US 20030015022A1
• Filed: 06/24/2002
• Published: 01/23/2003
• Est. Priority Date: 06/22/2001
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Streib, Martin, Stegmann, Volker, Hassdenteufel, Armin, Wiltsch, Peter, Fritz, Thorsten
• Granted Patent: US 6,845,652 B2
• Time in Patent Office: Days
• US Class Current: 73/40.5R
• CPC Class Codes: F02M 25/0818 having means for pressurising the evaporative emission space
• CPC Class Codes: G01M 3/025 Details with respect to the testing of engines or engine parts
• CPC Class Codes: G01M 3/3236 by monitoring the interior space of the containers
• CPC Class Codes: G01M 3/3263 using a differential pressure detector G01M3/3245, G01M3/3272 take precedence

Abstract

In a method and a device for leak testing of a vessel, e.g., a tank venting system of a motor vehicle, a leak-tightness measurement is performed by introducing a positive pressure or partial vacuum and detecting the variation over time of a positive pressure or partial vacuum in the vessel, and a reference measurement is performed using a reference leak. A conclusion is drawn as to the presence of a leak in the vessel by comparing the results of the leak-tightness measurement and the reference measurement. To avoid faulty diagnoses, the positive pressure or partial vacuum during the leak-tightness measurement and the reference measurement is detected by using a single pressure measuring device.

Claims

1. A method for leak testing a vessel, comprising the steps of:

introducing one of a positive pressure and a partial vacuum into the vessel;

detecting a variation over time of the one of the positive pressure and the partial vacuum in order to perform a leak-tightness measurement and a corresponding reference measurement using a reference leak; and

determining a presence of a leak in the vessel by comparing results of the leak-tightness measurement and the reference measurement;

wherein during the leak-tightness measurement and the reference measurement, the one of the positive pressure and the partial vacuum is detected using a single pressure measuring device.

2. The method according to claim 1, wherein:

the vessel is a tank venting system of a motor vehicle.

3. The method according to claim 1, further comprising:

alternatively subjecting the vessel and the reference leak to the one of the positive pressure and the partial vacuum; and

detecting and comparing respective resulting pressure variations upstream from a pressure source to one another, from which a determination is made as to leak-tightness of the vessel.

4. The method according to claim 3, further comprising:

determining a malfunction of the pressure source from a fluctuation over time in a pressure characteristic that occurs upstream from the pressure source.

5. The method according to claim 4, further comprising:

diagnosing at least one jammed pump vane from a pressure fluctuation.

6. A device for leak testing a vessel, comprising:

a reversing valve;

a pressure source that is optionally connectable to the vessel and to a reference leak using the reversing valve; and

a pressure measuring device connected upstream from the pressure source and for detecting a respective pressure present at the pressure source on a pressure side.

7. The device according to claim 6, wherein:

the vessel is a tank venting system of a motor vehicle.

8. The device according to claim 7, wherein:

the reference leak in an opened state is sealingly connected to one of the vessel and the tank venting system.

9. The device according to claim 6, further comprising:

an adsorption filter that is connected to the vessel via a connection line;

a vent line that is connected to the adsorption filter;

a diagnostic unit including at least a pressure source and the reference leak, the pressure source being connected upstream from the vent line; and

a pressure measuring device that is one of arranged in and arranged on the diagnostic unit and that is pressure-conductively connected at least to the pressure source.

10. The device according to claim 6, wherein:

the pressure source is a vane-type pump.

11. A diagnostic unit, comprising:

a pressure measuring device that is one of arranged in and arranged on the diagnostic unit and that is pressure-conductively connected to a pressure source.