Self-contained leak detection module having enclosure-mounted toggle levers for pump and valve

• US 6,192,743 B1
• Filed: 02/22/1999
• Issued: 02/27/2001
• Est. Priority Date: 02/25/1998
• Status: Expired due to Term

• Current Assignee: Siemens Canada Limited (Siemens AG)
• Original Assignee: Siemens Canada Limited (Siemens AG)
• Inventors: Perry, Paul Douglas
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): WIGGINS, JOHN DAVID
• Application Number:
  US09/253,994
• Time in Patent Office: 736 Days
• Field of Search: 73/40, 73/492, 73/497, 731/181, 123/520, 123/518, 123/516, 137/907
• US Class Current: 73/40
• CPC Class Codes: F02M 25/0818 having means for pressurising the evaporative emission space
• CPC Class Codes: Y10S 137/907 Vacuum-actuated valves

Abstract

A module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of an automotive vehicle fuel system. A pump disposed within interior space of the module has an inlet in communication with the interior space and a flow passage through which the evaporative emission space is pressurized by the pump. A vent valve within the interior space is selectively operable to a first state that vents the flow passage to the interior space of the module and to a second state that does not vent the flow passage to the interior space. An electromechanical actuator within the interior space operates both the pump and the vent valve. A first lever for operating the pump is mounted for pivotal motion on a wall of the enclosure, and a second lever for operating the vent valve is mounted for pivotal motion on a wall of the enclosure. The material of the parts that provide the pivotal mountings is polymeric. An electric circuit board assembly contains electric circuitry operatively connected to the actuator and with a pressure sensor for performing a test.

Claims

1. A module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle, the module comprising:

a walled enclosure comprising an interior space adapted to be communicated to atmosphere;

a pump disposed within the interior space comprising a pumping chamber having an inlet in communication with the interior space and a flow passage for communicating the pumping chamber with an evaporative emission space to allow the evaporative emission space to be pressurized by the pump;

a vent valve that is disposed within the interior space and is selectively operable to a first state that vents the flow passage to the interior space to thereby vent the evaporative emission space to atmosphere and to a second state that does not vent the flow passage to the interior space; and

an electric-operated actuator mechanism disposed within the interior space for operating the pump and the vent valve to perform a leak test on the evaporative emission space;

the actuator mechanism comprising a coupling through which one of the pump and the vent valve is operated, the coupling comprising a lever that has first and second lever arms and comprises a part having a formation that is proximate proximal ends of the first and second lever arms and is received in a complementary formation in a wall of the enclosure to thereby pivotally mount the lever on the wall of the enclosure.

2. A module as set forth in claim 1 in which the part comprises non-metallic material and the complementary formation in the wall of the enclosure also comprises non-metallic material.

3. A module as set forth in claim 2 in which the complementary formation in the wall of the enclosure comprises a channel that opens to the interior space of the enclosure.

4. A module as set forth in claim 3 in which the channel, as viewed in transverse cross section, comprises a polygonal shape having a rounded corner, and the formation of the part, as viewed in transverse cross section, comprises a rounded edge that bears on the rounded corner of the channel.

5. A module as set forth in claim 4 in which the part has a second formation disposed within the channel to provide a dimensional interference with the channel that prevents removal of both formations from the channel through a throat via which the channel opens to the interior space of the enclosure.

6. A module as set forth in claim 3 in which the channel, as viewed in transverse cross section, comprises a concave wall that opens via a throat to the interior space of the channel, and the formation in the part, as viewed in transverse cross section, comprises an enlargement that is disposed within the rounded wall of the channel and has a rounded surface bearing against the rounded wall of the channel, and a neck that extends from the enlargement and passes through the channel throat.

7. A module as set forth in claim 6 in which the throat of the channel is dimensioned to provide an interference with the enlargement that prevents removal of the enlargement from the channel via the throat.

8. A module as set forth in claim 1 in which the part comprises non-metallic material and forms at least a portion of each of the first and second lever arms, and one of the first and second lever arms further includes a ferromagnetic part fastened to the non-metallic material of the one lever arm.

9. A module as set forth in claim 1 in which the coupling operates the pump.

10. A module as set forth in claim 1 in which the coupling operates the vent valve.

11. An on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle and that comprises:

a pump for creating in the evaporative emission space a pressure condition suitable for performing a leak test;

a vent valve that is selectively operable to a first state for venting the evaporative emission space to atmosphere and to a second state for closing the evaporative emission space to atmosphere; and

an electric-operated actuator mechanism for operating at least one of the pump and the vent valve to perform a leak test on the evaporative emission space;

the actuator mechanism comprising a coupling through which one of the pump and the vent valve is operated, the coupling comprising a lever that has first and second lever arms and comprises a non-metallic part having a formation that is proximate proximal ends of the first and second lever arms and is received within a complementary formation of a non-metallic mounting to thereby pivotally mount the lever for rocking motion to operate the one of the pump and the vent valve.

12. A system as set forth in claim 11 in which the complementary formation in the mounting comprises a channel.

13. A module as set forth in claim 12 in which the channel, as viewed in transverse cross section, comprises a polygonal shape having a rounded corner, and the formation of the part, as viewed in transverse cross section, comprises a rounded edge that bears on the rounded corner of the channel.

14. A module as set forth in claim 13 in which the part has a second formation disposed within the channel to provide a dimensional interference with the channel that prevents removal of both formations from the channel through a throat of the channel.

15. A module as set forth in claim 12 in which the channel, as viewed in transverse cross section, comprises a concave wall having a throat, and the formation in the part, as viewed in transverse cross section, comprises an enlargement that is disposed within the rounded wall of the channel and has a rounded surface bearing against the rounded wall of the channel, and a neck that extends from the enlargement and passes through the channel throat.

16. A module as set forth in claim 15 in which the throat of the channel is dimensioned to provide an interference with the enlargement that prevents removal of the enlargement from the channel via the throat.

17. A module as set forth in claim 11 in which the part forms at least a portion of each of the first and second lever arms, and one of the first and second lever arms further includes a ferromagnetic part fastened to the non-metallic material of the one lever arm.

18. A module as set forth in claim 11 in which the coupling operates the pump.

19. A module as set forth in claim 11 in which the coupling operates the vent valve.

20. A module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle, the module comprising:

a walled enclosure comprising an interior space adapted to be communicated to atmosphere;

a pump disposed within the interior space comprising a pumping chamber having an inlet in communication with the interior space and a flow passage for communicating the pumping chamber with an evaporative emission space to allow the evaporative emission space to be pressurized by the pump;

a vent valve that is disposed within the interior space and is selectively operable to a first state that vents the flow passage to the interior space to thereby vent the evaporative emission space to atmosphere and to a second state that does not vent the flow passage to the interior space;

an electric-operated actuator mechanism disposed within the interior space for operating the pump and closing the vent valve to perform a leak test on the evaporative emission space;

a pressure sensor for sensing pressure in the flow passage; and

an electric circuit board assembly containing electric circuitry operatively connected to both the electric-operated actuator mechanism and the pressure sensor.

21. A module as set forth in claim 20 in which the electric circuit board assembly comprises a microprocessor that contains an algorithm for operating the actuator mechanism and for processing pressure information from the pressure sensor to perform a complete test.