Motorcycle fuel tank

• US 20060108369A1
• Filed: 11/15/2005
• Published: 05/25/2006
• Est. Priority Date: 11/19/2004
• Status: Active Grant

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Yamagata, Hiroshi, Hirose, Atsushi, Kitsunai, Toru
• Granted Patent: US 7,390,023 B2
• Time in Patent Office: Days
• US Class Current: 220/567.200
• CPC Class Codes: B62J 35/00 Fuel tanks specially adapted for motorcycles or engine-assisted cycles; Arrangements thereof fuel tanks forming part of cycle frames B62K11/00; tanks in general B60K ; closure caps for fuel tanks B60K15/0406

Abstract

A motorcycle fuel tank according to a preferred embodiment of the present invention includes an upper shell, and a lower shell including a body and fixing portions. The lower shell body is bonded to the upper shell and arranged to define a fuel storage space with the upper shell. The fixing portions are used to fix the lower shell body onto a motorcycle body. The lower shell is made of an aluminum alloy and the lower shell body and the fixing portions are formed by a casting process such that the fixing portions are integral with the lower shell.

Claims

1. A motorcycle fuel tank comprising:

an upper shell; and

a lower shell including fixing portions, the lower shell being bonded to the upper shell and defining a fuel storage space with the upper shell, the fixing portions arranged to attach the lower shell onto a motorcycle body;

wherein

the lower shell is made of a cast aluminum alloy such that the fixing portions are integral with the lower shell.

2. The fuel tank of claim 1, wherein the upper shell is made of a press-formed aluminum or an aluminum alloy material.

3. The fuel tank of claim 2, wherein the upper shell is made of Al, an Al—

Mg based alloy, or an Al—

Si—

Mg based alloy and the lower shell is made of an Al—

Si based alloy, an Al—

Si—

Mg based alloy, or an Al—

Si—

Cu based alloy.

4. The fuel tank of claim 1, further comprising a welded or brazed joint connecting the upper shell and the lower shell.

5. The fuel tank of claim 1, wherein the fixing portions include a first set of fixing portions arranged to be fixed on a first frame of the motorcycle body and a second set of fixing portions arranged to be fixed on a second frame of the motorcycle body.

6. The fuel tank of claim 5, wherein the lower shell includes a bottom and a side surface extending from a periphery of the bottom, the first set of fixing portions being arranged on the side surface.

7. The fuel tank of claim 6, wherein the first set of fixing portions includes two fixing portions and a rib portion arranged on the side surface to connect the two fixing portions of the first set together.

8. The fuel tank of claim 6, wherein the lower shell includes a fuel supply port having an opening through the bottom of the lower shell, and a flange arranged around the opening, wherein the fuel supply port and the lower shell are integral with each other.

9. The fuel tank of claim 6, wherein the second set of fixing portions includes two fixing portions respectively arranged on two opposing sides on the periphery of the bottom of the lower shell.

10. The fuel tank of claim 1, wherein the upper shell includes a plurality of upper sub-portions with welded or brazed joints connecting the sub-portions.

11. A motorcycle comprising:

a frame;

an engine supported on the frame; and

the fuel tank of claim 1, the fuel tank being fixed on the frame.

12. A motorcycle fuel tank comprising:

an upper shell; and

a lower shell including fixing portions, the lower shell being bonded to the upper shell and defining a fuel storage space with the upper shell, the fixing portions arranged to attach the lower shell onto a motorcycle body;

wherein

the upper and lower shells are made of aluminum or an aluminum alloy and have mutually different compositions.

13. The fuel tank of claim 12, wherein at least the lower shell is made of an aluminum alloy containing silicon and a weight percentage of silicon in the lower shell is greater than a weight percentage of silicon in the upper shell.

14. The fuel tank of claim 13, wherein the upper shell is made of Al, an Al—

Mg based alloy, or an Al—

Si—

Mg based alloy and the lower shell is made of an Al—

Si based alloy, an Al—

Si—

Mg based alloy, or an Al—

Si—

Cu based alloy.

15. The fuel tank of claims 13, further comprising a welded or brazed joint connecting the upper shell and the lower shell.

16. The fuel tank of claim 12, wherein the fixing portions include a first set of fixing portions arranged to be fixed on a first frame of the motorcycle body and a second set of fixing portions arranged to be fixed on a second frame of the motorcycle body.

17. The fuel tank of claim 16, wherein the lower shell includes a bottom and a side surface extending from a periphery of the bottom, the first set of fixing portions being arranged on the side surface.

18. The fuel tank of claim 17, wherein the first set of fixing portions includes two fixing portions and a rib portion arranged on the side surface to connect the two fixing portions of the first set together.

19. The fuel tank of claim 17, wherein the lower shell includes a fuel supply port having an opening through the bottom of the lower shell, and a flange arranged around the opening, wherein the fuel supply port and the lower shell are integral with each other by casting.

20. The fuel tank of claim 17, wherein the second set of fixing portions includes two fixing portions respectively arranged on two opposing sides on the periphery of the bottom of the lower shell.

21. The fuel tank of claim 12, wherein the upper shell includes a plurality of upper sub-portions with welded or brazed joints connecting the sub-portions.

22. A motorcycle comprising:

a frame;

an engine supported on the frame; and

the fuel tank of claim 12, the fuel tank being fixed on the frame.

23. A method of making a motorcycle fuel tank, the method comprising the steps of:

(A) making an upper shell;

(B) casting an integral lower shell having fixing portions from an aluminum alloy, the lower shell being arranged to define a fuel storage space with the upper shell, the fixing portions arranged to fix the lower shell onto a motorcycle body; and

(C) welding or brazing the upper shell and the lower shell together.

24. The method of claim 23, wherein the step (A) includes subjecting an aluminum plate or an aluminum alloy plate to a press forming process.

25. The method of claim 24, wherein the steps (A) and (B) include making at least the lower shell of an aluminum alloy containing silicon such that a weight percentage of silicon in the lower shell is greater than a weight percentage of silicon in the upper shell.

26. The method of claim 25, wherein the step (A) includes forming the upper shell of Al, an Al—

Mg based alloy, or an Al—

Si—

Mg based alloy and wherein the step (B) includes forming the lower shell of an Al—

Si based alloy, an Al—

Si—

Mg based alloy, or an Al—

Si—

Cu based alloy.

27. The method of claim 23, wherein the step (B) includes forming the lower shell so as to have a first set of fixing portions arranged to be fixed on a first frame of the motorcycle body and a second set of fixing portions arranged to be fixed on a second frame of the motorcycle body.

28. The method of claim 27, wherein the step (B) includes forming the lower shell to include a bottom and a side surface extending from a periphery of the bottom, and the first set of fixing portions being arranged on the side surface.

29. The method of claim 23, wherein the step (B) includes casting a fuel supply port integral with the lower shell, the fuel supply port having an opening through the bottom of the lower shell, and a flange arranged around the opening.

30. The method of claim 23, wherein the step (A) includes forming a plurality of upper sub-portions by subjecting a plate of aluminum or a plate of an aluminum alloy to a press forming process, and welding or brazing the upper sub-portions together to make the upper shell.

31. The method of claim 23, wherein the steps (A) and (B) include forming the upper and lower shells of aluminum or an aluminum alloy having mutually different compositions.