Evaporative emission control apparatus

• US 6,732,718 B2
• Filed: 03/01/2002
• Issued: 05/11/2004
• Est. Priority Date: 03/02/2001
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation, Nippon Soken, Inc. (DENSO Corporation)
• Original Assignee: DENSO Corporation, Nippon Soken, Inc. (DENSO Corporation)
• Inventors: Kobayashi, Yasunori, Amano, Noriyasu, Kano, Masao, Itakura, Hideaki
• Primary Examiner(s): Moulis, Thomas N.
• Application Number:
  US10/084,979
• Publication Number:
  US 20020121270A1
• Time in Patent Office: 802 Days
• Field of Search: 123/516, 123/518, 123/519, 123/520, 123/533
• US Class Current: 123/518
• CPC Class Codes: F02M 2025/0845 Electromagnetic valves
• CPC Class Codes: F02M 25/08 adding fuel vapours drawn from engine fuel reservoir electrical control of purge system F02D41/003
• CPC Class Codes: F02M 25/0836 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 Class Codes: F04B 45/041 double acting plate-like flexible pumping member
• CPC Class Codes: F04B 45/047 Pumps having electric drive

Abstract

In a double-acting diaphragm pump, a diaphragm is provided to divide a pump body into two pump chambers. An electromagnetic-type reciprocating actuator is provided in a housing hermetically integrated with the pump body. Different from an electric-type pump, the actuator is integrally mounted on the double-acting diaphragm pump and an entire system is hermetically sealed. Therefore, even if the diaphragm is torn, fuel vapor is prevented from leaking outside. Additionally, four check valves are provided to control the discharge of vapor from a canister side to an engine side. These check valves may employ a reed to control vapor flow or a spring and plate to control flow. In addition, since the pump may be a double-acting type, a large discharge volume is obtained and the pump can be made smaller. The pump may also be a non double-acting type.

Claims

1. An evaporative emission control apparatus comprising:

a fuel vapor adsorbing means connected to a fuel vapor generating source, the fuel vapor adsorbing means for storing adsorbent and for temporarily adsorbing fuel vapor;

a fuel vapor treating means for treating the fuel vapor removed from the fuel vapor adsorbing means; and

a drawing means provided on a purge pipe that connects the fuel vapor adsorbing means and the fuel vapor treating means, for drawing air though the fuel vapor adsorbing means to forcedly remove fuel vapor from the adsorbent and feed the fuel vapor into the fuel vapor treating means, wherein the drawing means has a double-acting diaphragm pump that includes a first pump chamber and a second pump chamber, one on each side of a diaphragm to draw fuel vapor.

2. The evaporative emission control apparatus according to claim 1, wherein the fuel vapor treating means has a combustion chamber of an internal combustion engine;

and

wherein an end of the purge pipe is connected to an air intake pipe of the internal combustion engine.

3. The evaporative emission control apparatus according to claim 2, wherein the double-acting diaphragm pump provides, as a diaphragm actuating means, a housing hermetically integrated with the diaphragm pump, a moving core provided in the housing and attached to the diaphragm, and a solenoid coil provided in the housing and for reciprocating the moving core by electromagnetic force that is generated and changed by electric power having AC voltage or pulse voltage.

4. The evaporative emission control apparatus according to claim 3, wherein a discharging amount per unit time of the double-acting diaphragm pump is changed by controlling at least one of a voltage, a current and a frequency supplied to the solenoid coil, and a purging amount of fuel vapor purged from the fuel vapor adsorbing means is controlled with the change of the discharge amount.

5. The evaporative emission control apparatus according to claim 4, wherein the moving core is made of a permanent magnet.

6. The evaporative emission control apparatus according to claim 5, wherein each of the pump chambers has a check valve at least in one of an inlet port and an outlet port thereof, the check valve being automatically opened and closed by a pressure difference between an upstream side and a downstream side of the pump chamber.

7. The evaporative emission control apparatus according to claim 6, wherein the check valve is a reed valve.

8. The evaporative emission control apparatus according to claim 7, wherein the check valve is arranged to be open during an absence of the pressure difference between the upstream side and the downstream side when a pumping operation is stopped.

9. The evaporative emission control apparatus according to claim 8, further comprising:

a first open/close valve provided on a purge pipe connecting the double-acting diaphragm pump and the fuel vapor adsorbing means.

10. The evaporative emission control apparatus according to claim 9, further comprising:

a second open/close valve provided at an air intake side of the fuel vapor adsorbing means; and

a pressure detecting means that detects air pressure in the fuel vapor adsorbing means, the fuel vapor generating source being connected to the fuel vapor adsorbing means, and the double-acting diaphragm pump.

11. The evaporative emission control apparatus according to claim 3, wherein the moving core is made of a permanent magnet.

12. The evaporative emission control apparatus according to claim 11, wherein each of the pump chambers has a check valve at least in one of an inlet port and an outlet port thereof, the check valve being automatically opened and closed by a pressure difference between an upstream side and a downstream side of the pump chamber.

13. The evaporative emission control apparatus according to claim 12, wherein the check valve is a reed valve.

14. The evaporative emission control apparatus according to claim 13, wherein the check valve is arranged to be open during an absence of the pressure difference between the upstream side and the downstream side when a pumping operation is stopped.

15. The evaporative emission control apparatus according to claim 14, further comprising:

a first open/close valve provided on a purge pipe connecting the double-acting diaphragm pump and the fuel vapor adsorbing means.

16. The evaporative emission control apparatus according to claim 15, further comprising:

a second open/close valve provided at an air intake side of the fuel vapor adsorbing means; and

a pressure detecting means that detects air pressure in the fuel vapor adsorbing means, the fuel vapor generating source being connected to the fuel vapor adsorbing means, and the double-acting diaphragm pump.

17. The evaporative emission control apparatus according to claim 1, wherein each of the pump chambers has a check valve at least in one of an inlet port and an outlet port thereof, the check valve being automatically opened and closed by a pressure difference between an upstream side and a downstream side of the pump chamber.

18. The evaporative emission control apparatus according to claim 17, wherein the check valve is a reed valve.

19. The evaporative emission control apparatus according to claim 18, wherein the check valve is arranged to be open during an absence of the pressure difference between the upstream side and the downstream side when a pumping operation is stopped.

20. The evaporative emission control apparatus according to claim 19, further comprising:

a first open/close valve provided on a purge pipe connecting the double-acting diaphragm pump and the fuel vapor adsorbing means.

21. The evaporative emission control apparatus according to claim 20, further comprising:

a second open/close valve provided at an air intake side of the fuel vapor adsorbing means; and

a pressure detecting means that detects air pressure in the fuel vapor adsorbing means, the fuel vapor generating source connected to the fuel vapor adsorbing means, and the double-acting diaphragm pump.

22. An evaporative emission control apparatus comprising:

a fuel vapor adsorbing means connected to a fuel vapor generating source, the fuel vapor adsorbing means for storing adsorbent and for temporarily adsorbing fuel vapor;

a fuel vapor treating means for treating the fuel vapor removed from the fuel vapor adsorbing means; and

a drawing means provided on a purge pipe that connects the fuel vapor adsorbing means and the fuel vapor treating means, for drawing air through the fuel vapor adsorbing means to forcedly remove fuel vapor from the adsorbent and feed the fuel vapor into the fuel vapor treating means, wherein the drawing means has a diaphragm pump with a chamber to draw fuel vapor;

wherein the diaphragm pump provides, as a diaphragm actuating means, a housing hermetically integrated with the diaphragm pump, a moving core provided in the housing and attached to the diaphragm, and a solenoid coil provided in the housing and for reciprocating the moving core by electromagnetic force that is generated and changed by electric power having AC voltage or pulse voltage; and

the chamber is continuously compressed by every back and forth motion of the movable core thereby continuously drawing the fuel vapor.

23. The evaporative emission control apparatus according to claim 22, wherein the fuel vapor treating means has a combustion chamber of an internal combustion engine;

and

wherein an end of the purge pipe is connected to an air intake pipe of the internal combustion engine.

24. The evaporative emission control apparatus according to claim 22, wherein a discharging amount per unit time of the diaphragm pump is changed by controlling at least one of a voltage, a current and a frequency supplied to the solenoid coil, and a purging amount of fuel vapor purged from the fuel vapor adsorbing means is controlled with the change of the discharge amount.

25. The evaporative emission control apparatus according to claim 24, wherein the moving core is made of a permanent magnet.

26. The evaporative emission control apparatus according to claim 25, wherein the pump chamber has a check valve at least in one of an inlet port and an outlet port thereof, the check valve being automatically opened and closed by a pressure difference between an upstream side and a downstream side of the pump chamber.

27. The evaporative emission control apparatus according to claim 26, wherein the check valve is a reed valve.

28. The evaporative emission control apparatus according to claim 27, wherein the check valve is arranged to be open during an absence of the pressure difference between the upstream side and the downstream side when a pumping operation is stopped.

29. The evaporative emission control apparatus according to claim 28, further comprising:

a first open/close valve provided on a purge pipe connecting the diaphragm pump and the fuel vapor adsorbing means.

30. The evaporative emission control apparatus according to claim 29, further comprising:

a second open/close valve provided at an air intake side of the fuel vapor adsorbing means; and

a pressure detecting means that detects air pressure in the fuel vapor adsorbing means, the fuel vapor generating source connected to the fuel vapor adsorbing means, and the diaphragm pump.

31. An evaporative emission control apparatus comprising:

a fuel vapor adsorbing means connected to a fuel vapor generating source, the fuel vapor adsorbing means for storing adsorbent and for temporarily adsorbing fuel vapor;

a fuel vapor treating means for treating the fuel vapor removed from the fuel vapor adsorbing means; and

a drawing means provided on a purge pipe that connects the fuel vapor adsorbing means and the fuel vapor treating means, for drawing air through the fuel vapor adsorbing means to forcedly remove fuel vapor from the adsorbent and feed the fuel vapor into the fuel vapor treating means, wherein the drawing means has a double-acting diaphragm pump that includes a first pump chamber and a second pump chamber, one on each side of a diaphragm to draw fuel vapor, the first and second pump chambers forming a parallel passage to an intake pipe and wherein the first and second pump chambers are alternately compressed by reciprocation of the diaphragm to thereby continuously draw the fuel vapor through the parallel passage.

32. An apparatus comprising:

a container connected to a fuel vapor generating source, the container storing adsorbent for temporarily adsorbing fuel vapor;

an intake pipe of an internal combustion engine; and

a double-acting diaphragm pump, provided on a purge pipe that connects the container and the intake pipe, for drawing air through the container to forcedly remove fuel vapor from the adsorbent and feed the fuel vapor into the intake pipe, wherein the double-acting diaphragm pump includes a first pump chamber and a second pump chamber, one on each side of a diaphragm to draw fuel vapor.

33. The evaporative emission control apparatus according to claim 32, wherein the first and second pump chambers form a parallel passage to the intake pipe, and the first and second pump chambers are alternately compressed by reciprocation of the diaphragm to thereby continuously draw the fuel vapor through the parallel passage.

34. An apparatus comprising:

a container connected to a fuel vapor generating source, the container storing adsorbent for temporarily adsorbing fuel vapor;

an intake pipe of an internal combustion engine;

a diaphragm pump, provided on a purge pipe that connects the container and the intake pipe, for drawing air through the container to forcedly remove fuel vapor from the adsorbent and feed the fuel vapor into the intake pipe, wherein the diaphragm pump includes a chamber to draw fuel vapor,

a housing hermetically integrated with the diaphragm pump;

a moving core provided in the housing and attached to the diaphragm; and

a solenoid coil provided in the housing for reciprocating the moving core by electromagnetic force that is generated and changed by electric power having AC voltage or pulse voltage;

wherein the chamber is continuously compressed by every back and forth motion of the movable core thereby continuously drawing the fuel vapor.