Method of fabricating a gas tank

• US 20020121013A1
• Filed: 03/14/2002
• Published: 09/05/2002
• Est. Priority Date: 10/29/1999
• Status: Active Grant

• Current Assignee: Kyle P. Krejci
• Original Assignee: Kyle P. Krejci
• Inventors: Krejci, Kyle P.
• Granted Patent: US 6,725,519 B2
• Time in Patent Office: Days
• US Class Current: 29/421.1
• CPC Class Codes: B23K 11/105 Stitch welding
• CPC Class Codes: B23K 2101/12 Vessels
• 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
• CPC Class Codes: F17C 1/00 Pressure vessels, e.g. gas cylinder, gas tank, replaceable cartridge pressurised apparatus for purposes other than storage, see the relevant subclasses such as A62C, B05B; associated with vehicles, see the appropriate subclass of classes B60 - B64; pressure vessels in general F16J12/00 ; autoclaves B01J3/04; tank vehicles B60P3/22; railway tank wagons for carrying fluent materials B61D5/00; accumulators for supplying fluid under pressure F15B1/04; liquefied gas stoves F24C3/00
• CPC Class Codes: F17C 13/002 for vessels under pressure F17C13/008 and F17C13/02 - F17C13/12 take precedence
• CPC Class Codes: F17C 2209/221 Welding
• CPC Class Codes: F17C 2223/0123 gaseous, e.g. CNG, GNC
• CPC Class Codes: F17C 2270/0168 by vehicles
• CPC Class Codes: Y10T 29/49796 Coacting pieces
• CPC Class Codes: Y10T 29/49805 Shaping by direct application of fluent pressure
• CPC Class Codes: Y10T 29/49893 Peripheral joining of opposed mirror image parts to form a hollow body

Abstract

A method of making a gas tank includes hydroforming two halves and welding the halves together. Two types of welds are used in welding the two halves together, tack welds for holding the two halves together, and stitch welds to complete the welding of the two halves. Additional steps are taken prior to the finishing stitch welds. Reinforcement is added where necessary. Double tanks, for both gasoline and oil, are also fabricated by essentially the same method steps.

Claims

1. A method of making a gas tank comprising the steps of:

hydroforming two side halves of the gas tank;

tack welding the two side halves together;

cutting out a portion of the tack welded side halves for a bottom tunnel;

forming the bottom tunnel;

welding the formed bottom tunnel to the two side halves;

forming a bottom rear end piece;

welding the formed bottom rear end piece to the two side halves; and

welding the tacked side halves to form a tank.

2. The method of claim 1 which includes the further steps of:

forming mounting brackets;

welding the formed mounting brackets to the welded tank;

drilling holes in the mounting brackets;

drilling crossover holes and petcock holes;

placing tapped mounting bungs, crossover bungs, and petcock bungs in the respective drilled holes;

welding the mounting bungs, crossover bungs, and petcock bungs in their respective holes;

drill a gas cap fitting hole;

positioning a gas cap fitting in the gas cap fitting hole;

welding a gas cap fitting in the gas cap fitting hole;

positioning a seat pocket plate on the gas tank; and

welding the seat pocket plate to the gas tank.

3. The method of claim 2 which further includes the step of cleaning out the interior of the welded tank prior to the step of welding the gas cap fitting.

4. The method of claim 2 which further includes the step of pressure testing the tank after welding the gas cap fitting into the gas cap fitting hole.

5. The method of claim 1 in which the step of welding the tacked side halves further includes the step of stitch welding the tacked side halves.

6. The method of claim 1 in which the step of hydroforming two side halves includes the further step of trimming excess material from the hydroformed side halves.

7. The method of claim 1 which further includes the step of welding a sheet metal reinforcing strip to the inside of the two halves after the side halves have been cut to form a bottom tunnel.

8. The method of claim 1 in which the welding steps include stitch welding.

9. The method of claim 1 which includes the further steps of:

cutting off an oil portion to divide the tank into two portions;

welding plates onto the two portions;

drilling an oil cap hole;

welding the two portions together; and

welding an oil cap bung to the oil cap hole.

10. The method of claim 9 which includes the further steps, after the step of cutting off the oil portion, of:

cutting off a side panel for recessed panel;

drilling holes for return fittings in the recessed panel;

positioning return fittings in the drilled holes;

welding the return fittings in the drilled holes; and

tack welding the recessed panel.

11. The method of claim 10 which includes the further steps of:

drilling fitting holes; and

positioning and welding a breather tube.

12. The method of claim 11 which includes the further steps of:

welding the recessed panel, and

welding fittings in the drilled fitting holes after the two portions have been welded together.

14. The method of claim 13 in which the step of welding the tacked side halves includes the step of stitch welding the tacked side halves.

15. The method of claim 13 which further includes the step of welding a reinforcing strip to the inside of the two halves after the side halves have been cut to form the tunnel.

16. The method of claim 13 which further includes the steps of forming a bottom rear end piece, and welding the formed rear end piece to the two side halves.

17. The method of claim 13 in which the step of hydroforming two side halves includes the further step of trimming excess material from the hydroformed side halves.

18. The method of claim 13 which includes the further steps of:

forming mounting brackets;

welding the formed mounting brackets to the welded tank

drilling holes in the mounting brackets;

drilling crossover holes and petcock holes in the welded tank;

placing tapped mounting bungs, crossover bungs, and petcock bungs in the respective drilled holes;

welding the mounting bungs, crossover bungs, and petcock bungs in their respective holes;

drilling a gas cap fitting hole;

positioning a gas cap fitting in the gas cap fitting hole; and

welding the gas cap fitting in the gas cap fitting hole.

13. A method for making a motorcycle gas tank comprising the steps of:

hydroforming two side halves for the tank;

tack welding the two side halves together;

cutting out a portion of the tack welded side halves for a bottom tunnel;

forming a bottom tunnel;

welding the formed bottom tunnel to the two side halves; and

welding the tacked side halves to form a tank.

19. The method of claim which includes the further steps of forming a rear end piece and welding the formed rear end piece to the two side halves.