JP2511766B2 - Fuel tank manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a fuel tank for a motorcycle or the like.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional fuel tank for a motorcycle has stays d and e on the outer surface of a tank body formed by joining a pair of upper and lower half shells a and b at their flanges c. Are polymerized and fixed, and at the same time, pipes composed of a lubrication mouthpiece f and a fuel cock set pipe g are inserted and fixed in the tank body. At the time of manufacturing, after inserting the base f and the set pipe g into the upper and lower half shells a and b respectively and brazing them with silver brazing or the like, the flanges c of the two half shells a and b are overlapped and misaligned. Not to be attached by spot welding, and in this state, the flange c is sandwiched between the upper and lower roller electrodes of the seam welding machine to perform seam welding, and then the patch plates h and i are spotted on the outer surface of the upper half shell a.
Welding, and the stays d and e are arc-welded on these . In the figure, black dots are dents of spot welding, S is a seam welding line, and W is a bead for arc welding or brazing.

[0003]

By the way, as described above,
Small curvature when seam welding the flanges of both shells
The roller electrode is a tank in the part that is recessed inward at the radius.
Since it interferes with the main body, seam welding cannot be performed, and the tank shape
There is a problem that the degree of freedom in design is restricted. this
In contrast, the flanges of both half-shells should be joined by laser welding.
In this case, such a problem does not occur, which is advantageous. In this case,
Pipes for the tank body to unify the contact plan
It is also conceivable to join the above by laser welding. Only
And insert it into the component mounting hole on the tank body where the pipes are inserted.
In order to ensure the airtightness of the joint,
Even if laser welding is applied over, like the flange part
Airtightness cannot be secured stably. Also, check the corrosion and rust prevention.
As a result, the tank body and pipes are treated with a corrosion-resistant surface treatment material.
If formed, laser welding around the entire circumference of the component mounting hole
If it is applied, the amount of heat input is
As the size increases, the extent of deterioration of the surface treatment layer due to heat increases.
Corrosion resistance is reduced. In view of the above points, the present invention is a half
Joining at the flange of the shell and the tank body
Laser welding is a unified method for joining pipes.
And the airtightness of the joint between the tank body and the pipes.
It is an object of the present invention to provide a method for manufacturing a fuel tank that ensures corrosion resistance and corrosion resistance .

[0004]

In order to achieve the above object,
The present invention, laser in both of the flange half shell pair
The pipe is attached to the tank body that is constructed by welding
A method of manufacturing a fuel tank, comprising the step of inserting and fixing a pipe , wherein the pipe is joined to the tank body by a pipe.
There is a space in the circumferential direction of the component mounting hole in the tank body where the
Laser welding applied intermittently and then
It is characterized in that soldering is performed over the entire circumference of the product mounting hole .

[0005]

[Action] To perform the laser welding flange joint of the half-shell of the pair, you can join the flanges without causing interference problems such the roller electrode and the tank body, such as when performing seam welding, to the tank shape The degree of freedom in design is increased, and the width of the flange can be narrowed to further reduce the weight. Further, component mounting holes in the circumferential direction facilities intermittently laser welding at intervals in Sutame, thermal effects of laser welding
There is a corrosion resistance and the bonding strength is ensured is suppressed as much as possible,
After that, since soldering is applied over the entire circumference of the component mounting hole,
Airtightness Ru is secured.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a fuel tank manufactured according to the present invention, which comprises a pair of upper and lower half-shells 1 and 2 which are press-molded to form a tank body and an upper half-shell 1. It is composed of stays 3 and 4 which are polymerized and fixed to each other, a lubrication mouthpiece 5 which is inserted and fixed to the upper half shell 1, and a fuel cock set pipe 6 which is inserted and fixed to the lower half shell 2.

In manufacturing the above fuel tank, first, the stays 3 and 4 are directly attached to the outer surface of the upper half shell 1 by laser welding. At this time, the laser welding lines R3 and R4 are appropriately set in consideration of the joining strength and stress dispersion of the stays 3 and 4. Next, as shown in FIG. 2, the base 5 is inserted and set in the part mounting hole for the base formed in the upper half shell 1, and there is a space in the circumferential direction of the mounting hole as shown by R5 in the figure. Laser welding is performed intermittently, whereby the base 5 is joined to the hole edge of the mounting hole with the required strength while suppressing the thermal effect as much as possible, and then the soldering H is applied to the entire circumference of the mounting hole. To secure the airtightness and corrosion resistance of the joint and strengthen the strength.

Further, as shown in FIG. 3, the set pipe 6 is inserted and set in the component mounting hole for the pipe formed in the lower half shell 2, and there is a space in the circumferential direction of the mounting hole in the same manner as described above. Laser welding is performed intermittently as indicated by middle R6, and then soldering H is performed.

After assembling the accessory parts 3 to 6 on the respective half shells 1 and 2 as described above, the upper and lower half shells 1 and 2 are overlapped with the flanges 1a and 2a of the upper and lower half shells 1 and 2. As shown in, the lower half shell 2 is set on the jig 7 and fixed by the clamper 8. In this state, the laser beam B is applied from above to the flange 2a of the lower half shell 2 by the laser irradiation head 9. The head 9 is moved by a robot (not shown) and the flanges 1a and 2a are laser-welded over the entire circumference as indicated by R in FIG. 1 to hermetically bond the flanges 1a and 2a with a required bonding strength. In this case, even if the stay 3 overlaps the flange 1a of the upper half shell 1, the flange 1 is formed by the laser beam irradiation from the flange 2a side of the lower half shell 2.
It is possible to join a and 2a without trouble.

Here, in laser welding, since heat can be concentratedly input in a narrow range, each half-shell 1, 2 and accessory 3 are attached.
6 to 6 made of corrosion-resistant surface-treated steel material such as Pb-Sn system, the deterioration of the surface-treated layer due to heat is limited to a narrow range, and at least the joint portion of the base 5 and the set pipe 6 is soldered as described above. If the fuel tank is not exposed to the outer surface of the vehicle body like the inner tank of the scooter, it is possible to reduce the cost by providing the airtightness and the corrosion resistance.

In this embodiment, the base 5 and the set pipe 6 are used.
The joining was performed by laser welding and soldering, but pipes such as the base 5 and the set pipe 6 may be joined by brazing when rust prevention treatment such as painting is performed after joining.

[0012]

As is apparent from the above description, according to the present invention, the joining and piecing of the pair of half shell flanges are performed.
Bonding scheme used in the bonding of the flop such that enables the centralized order process integration and automation in laser welding, the attained and improvement of space and productivity, increased design flexibility regarding tank shape. Also, pipes can be
Since it is joined by intermittent welding, the heat effect on the welded part is possible.
The semi-shells and pipes are treated with corrosion-resistant surface-treated steel.
Deterioration of the surface treatment layer when formed is suppressed and corrosion resistance
As well as securing the joint strength, then soldering
In order to ensure airtightness by shaving,
No post-treatment is required and productivity can be improved.

[0013]

[Brief description of drawings]

FIG. 1 is a perspective view of an example of a fuel tank manufactured according to the present invention.

2A and 2B are views showing a joint portion of a lubrication die, in which FIG. 2A is a sectional view and FIG. 2B is a plan view.

3A and 3B are views showing a joint portion of a fuel cock set pipe, in which FIG. 3A is a sectional view and FIG. 3B is a plan view.

FIG. 4 is a diagram showing a flange joining process.

FIG. 5 is a perspective view of a fuel tank manufactured by a conventional method.

[Explanation of symbols]

 1, 2 Half-shell 1a, 1b Flange 3, 4 Stays 5, 6 Pipes

Claims (1)

(57) [Claims] 1. A pair of half-shells at both flanges
Pa in the tank body constituted by joining by laser welding
A method of manufacturing a fuel tank, comprising the step of inserting and fixing the pipes , wherein the pipes are joined to the tank body by a pipe.
Space in the circumferential direction of the component mounting holes in the tank body for inserting
The laser welding was applied intermittently, and then
A method of manufacturing a fuel tank, characterized in that soldering is performed over the entire circumference of the component mounting hole .