Fuel-vapor discharge structure in a fuel tank for engine apparatus

• US 20080178851A1
• Filed: 08/28/2006
• Published: 07/31/2008
• Est. Priority Date: 08/26/2005
• Status: Active Grant

• Current Assignee: Yamaha Motor Power Products Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Motor Power Products Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Makino, Satoshi
• Granted Patent: US 7,540,276 B2
• Time in Patent Office: Days
• US Class Current: 123/520
• CPC Class Codes: F02M 33/08 returning to the fuel tank

Abstract

A fuel tank has a fuel-vapor discharge structure in which the piping connecting to external equipment is not obtrusive. The fuel-vapor discharge structure allows the passage of fuel vapor between an upper space in the fuel tank and an induction system. The communication passage can be formed by a communication tube arranged vertically within the interior of the fuel tank and a connecting tube located outside the fuel tank. A lower portion of the fuel tank includes a one-way valve which allows fuel vapor to flow from the fuel tank to the induction system.

Claims

1. A fuel-vapor discharge structure for a fuel tank comprising:

a communication passage between an upper space of a fuel tank and outside of the fuel tank; and

an extraction portion disposed at a bottom of the fuel tank, wherein a portion of the communication passage extends between the upper space and the extraction portion of the fuel tank.

2. The fuel-vapor discharge structure according to claim 1 further comprising an air induction system, wherein a distal end portion of the communication passage disposed outside the fuel tank is in flow communication with the air induction system.

3. The fuel-vapor discharge structure according to claim 1, wherein a portion of the communication passage located between the extraction portion and the upper space is a communication tube having its axis oriented in a substantially vertical direction.

4. The fuel-vapor discharge structure according to claim 3 further comprising a cylindrical portion projecting downward from the bottom of the fuel tank, and wherein a lower end portion of the communication tube is connected to the cylindrical portion.

5. The fuel-vapor discharge structure according to claim 4 further comprising a recess, the recess being formed in the bottom of the fuel tank, and wherein the extraction portion is disposed within the recess.

6. The fuel-vapor discharge structure according to claim 4, wherein a portion of the communication tube on the outside of the fuel tank is formed with a connecting tube connected to the extraction portion.

7. The fuel-vapor discharge structure according to claim 1 further comprising a one-way valve disposed within the communication passage, the one-way valve being adapted to open when a fuel vapor pressure exceeds a predetermined value.

8. The fuel-vapor discharge structure according to claim 4, wherein the one-way valve is disposed within a hole in the extraction portion.

9. A fuel-vapor discharge system for a fuel tank comprising:

a communication passage between an inside and outside of a fuel tank, a portion of the communication passage being disposed within the fuel tank; and

an extraction portion being disposed at the bottom of the fuel tank.

10. The fuel-vapor discharge system according to claim 9, wherein the extraction portion is a separate member attached to the fuel tank.

11. The fuel-vapor discharge structure according to claim 9 further comprising an induction system, the induction system being in flow communication with the communication passage.

12. The fuel-vapor discharge structure according to claim 11, wherein the induction system includes an air filter and a carburetor located downstream of the air filter.

13. The fuel-vapor discharge structure according to claim 9, wherein a portion of the communication passage between the inside and outside of the fuel tank has an axis that is disposed in a substantially vertical direction.

14. The fuel-vapor discharge structure according to claim 9, wherein at least a portion of the extraction portion is cylindrically shaped and projects from a bottom surface of the fuel tank in a downward direction.

15. The fuel-vapor discharge structure according to claim 9, wherein at least a portion of the communication tube disposed outside the fuel tank includes a connecting tube, the connecting tube being connected to the extraction portion.

16. The fuel-vapor discharge structure in a fuel tank for an engine apparatus according to claim 9 further comprising a one-way valve, the one-way valve being disposed in the communication passage and being configured to open when vapor pressure within the fuel tank exceeds a predetermined value.

17. A fuel tank for an engine generator comprising:

a lower surface;

an internal upper region;

a member having an internal passageway that extends between the upper region and the lower surface, at least a portion of the member being disposed within the fuel tank; and

an extraction portion disposed on the lower surface and in flow communication with internal passageway.

18. The fuel tank according to claim 17, wherein the extraction portion is integral to the fuel tank.

19. The fuel tank according to claim 17, wherein at least a portion of the member has an axis that is disposed in a substantially vertical direction.

20. The fuel tank according to claim 17, wherein at least a portion of the extraction portion has a cylindrically shape and projects from the lower surface in a downward direction.

21. The fuel tank according to claim 17 further comprising a one-way valve disposed within the extraction portion, the one-way valve being adapted to open when a fuel vapor pressure within the fuel tank exceeds a predetermined value.