Pump Assembly and Method for Leak Detection of Fluid System

• US 20090007638A1
• Filed: 07/05/2007
• Published: 01/08/2009
• Est. Priority Date: 07/05/2007
• Status: Active Grant

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: Chrysler Group LLC (Stellantis NV)
• Inventors: Meskouri, Mohamed S., Wade, Leon T., Clar, Baltasar, Kahlon, Awtar S., Engel, Gary H.
• Granted Patent: US 7,624,624 B2
• Time in Patent Office: Days
• US Class Current: 73/40
• CPC Class Codes: F02M 25/0818 having means for pressurising the evaporative emission space

Abstract

A method of detecting a leak in a fluid system, which includes a switch that changes state according to pressure in the fluid system. The method includes changing pressure in the fluid system with a pump assembly. The pump assembly includes a predetermined leak that is in fluid communication with the fluid system and that causes the switch to change state after a predetermined time period. The method also includes detecting a leak in the fluid system if the switch changes state within an amount of time less than the predetermined time period.

Claims

1. A method of detecting a leak in a fluid system, the fluid system including a switch that changes state according to pressure in the fluid system, the method comprising:

changing pressure in the fluid system with a pump assembly, the pump assembly including a predetermined leak that is in fluid communication with the fluid system and which causes the switch to change state after a predetermined time period; and

detecting a leak in the fluid system if the switch changes state within an amount of time less than the predetermined time period.

2. The method of claim 1, wherein the amount of time is at least approximately five (5) seconds and at most approximately twenty {20} seconds from the time that the pump assembly achieves a predetermined pressure in the fluid system.

3. The method of claim 2, wherein the predetermined pressure is approximately 1.5 inches H₂O of a vacuum in the fluid system.

4. The method of claim 1, wherein the predetermined teak is at least approximately 0.010 inches wide.

5. The method of claim 1, wherein the changing pressure in the fluid system comprises reducing pressure in the fluid system.

6. The method of claim 1, wherein the detecting a leak comprises detecting a leak if the switch changes state from CLOSED to OPEN within the amount of time less than the predetermined time period.

7. The method of claim 1, further comprising stopping the pump assembly, and wherein the detecting a leak comprises detecting a leak in the fluid system if the switch changes state within the amount of time from the time that the pump assembly is stopped.

8. A method of defecting a leak in a vehicle fuel system, the vehicle fuel system including a switch that changes state according to pressure in the vehicle fuel system, the method comprising:

changing pressure in the vehicle fuel system with a pump assembly, the pump assembly including a predetermined leak that is in fluid communication with the vehicle fuel system and which causes the switch to change state after a predetermined time period; and

detecting a leak in the vehicle fuel system if the switch changes state within an amount of time less than the predetermined time period.

9. The method of claim 8, wherein the amount of time is at least approximately five (5) seconds and at most approximately twenty (20) seconds from the time that the pump assembly achieves a predetermined pressure in the vehicle fuel system.

10. The method of claim 9, wherein the predetermined pressure is approximately 1.5 inches H₂O of a vacuum in the vehicle fuel system.

11. The method of claim 8, wherein the predetermined leak is at least approximately 0.010 inches wide.

12. The method of claim 8, wherein the changing pressure in the vehicle fuel system comprises reducing pressure in the vehicle fuel system.

13. The method of claim 8, wherein the defecting a leak comprises detecting a leak if the switch changes state from CLOSED to OPEN within the amount of time less than the predetermined time period.

14. The method of claim 8, further comprising stopping the pump assembly, and wherein the detecting a leak comprises detecting a leak in the vehicle fuel system if the switch changes state within the amount of time from the time that the pump assembly is stopped.

15. The method of claim 8, further comprising fluidly coupling the pump assembly to the vehicle fuel system via a fuel filler tube of the vehicle.

16. A pump assembly for leak detection of a fuel system of a vehicle, the fuel system including a switch that changes state according to pressure in the fuel system, the pump assembly comprising:

a pump for changing pressure in the fuel system;

a pipe for fluidly coupling the pump to the fuel system;

a coupling member for coupling to the vehicle such that the pipe is in fluid communication with the fuel system;

wherein the pipe includes a predetermined leak that is in fluid communication with the fluid system and that causes the switch to change state after a predetermined time period.

17. The pump assembly of claim 16, wherein the predetermined leak is at least approximately 0.010 inches wide.

18. The pump assembly of claim 16, wherein the vehicle comprises a fuel filler tube, and wherein the coupling member is threaded so as to threadably couple to the vehicle via the fuel filler tube.

19. The pump assembly of claim 16, wherein the pump is a vacuum pump for drawing a vacuum in the fuel system.

20. The pump assembly of claim 16, further comprising a check valve for allowing fluid flow in one direction through the pipe and limiting fluid flow in an opposite direction through the pipe.