JP2002346761A - Electrode structure for seam welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform the exchanging operation of a bearing ring fitted to an electrically conductive shaft when weared in an electrode for seal welding where the bearing ring is supported by a bearing, and a disk electrode is fitted to the tip of the electrically conductive shaft. SOLUTION: A first electrically conductive shaft 4 in which a disk electrode 3a is freely fitted to the tip, and a second electrically conductive shaft 5 in which terminal parts are fitted to a rotary part 9 by bolts 10 are freely split and joined by a screw system. This split part is located on the rear side of a bearing 7, and the exchange of the bearing ring 6 when weared is easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure of an electrode for seam welding.

[0002]

2. Description of the Related Art Conventionally, when welding a container requiring airtightness, such as a fuel tank of a motorcycle, a workpiece to be welded is moved while pressing a welding portion of the workpiece with a pair of rotating disk electrodes. By doing so, seam welding such as continuous welding is performed, as such a welding machine,
For example, a welding machine 51 as shown in FIG. 4 is known. The welding machine 51 includes an upper electrode 52 and a lower electrode 53. Each of the electrodes 52, 53 is provided with a disk electrode 52a, 53a rotatable around an axis. 53a sandwiches the welded portion of the workpiece and continuously welds it while applying pressure.
The lower electrode 53 is, as shown in FIG.
4 and a conductive shaft 56 rotatably supported by the holding plate 55, and a bearing ring 57 fitted to a bearing portion of the conductive shaft 56. And the disk electrode 5
Reference numeral 3a is freely attachable to the distal end of the conductive shaft 56.

[0003]

By the way, in the lower electrode 53 having the above structure, each of the disk electrodes 52a,
When the bearing ring 3a or the bearing ring 57 to which the load from the bearing 54 is liable to be worn is worn, the disc electrodes 52a and 53a are displaced from the center, and the conductivity of the electrode contact portion is reduced, resulting in poor welding. Disc electrodes 52a, 53a, bearing ring 57
For example, when the bearing ring 57 is replaced, the conductive shaft 56 is an integral structure, so the bolt hole 56 on the base end side of the conductive shaft 56 is used.
The bearing ring 57 must be replaced by removing all bolts (not shown) that are fastened through b, and there is a problem that the replacement operation requires time and is troublesome.

Therefore, the present invention provides, for example, a conductive shaft 56.
It is an object of the present invention to easily perform a replacement operation when the bearing ring 57 fitted to the bearing is worn.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a structure of a seam welding electrode in which a disk electrode is freely attached to a tip of a conductive shaft rotatably supported by a bearing. The conductive shaft can be divided on the rear side of the bearing.

[0006] By making the conductive shaft dividable in this way, it is easy to replace the bearing ring fitted to the bearing portion, and it is possible to prevent a decrease in the operability of the equipment. Here, the method of dividing and coupling the conductive shaft is arbitrary, but a structure that can easily perform the division and coupling work is preferable. In addition, by making it possible to divide on the rear side of the bearing, even if, for example, a screw-type splitting / coupling method is adopted, it is possible to suppress an excessive load from being applied to the fragile split screw part during welding, and to achieve durability. There is no problem that the performance is reduced. That is, most of the reaction force applied by the disk electrode is supported by the bearing, and the load directly acting on the divided screw portion is reduced.

Further, in the present invention, the divided structure of the conductive shaft is a screw type.

[0008] If the dividing structure is made into a screw type as described above, the dividing and joining can be facilitated, and the work of replacing the worn parts can be further facilitated. Here, in the case of the screw type, it is preferable that the tightening direction of the screw and the rotating direction of the disk electrode during welding match to prevent the screw from being loosened during welding.

[0009]

Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is an exploded perspective view of a lower electrode adopting the electrode structure for seam welding according to the present invention, FIG. 2 is a longitudinal sectional view of an assembled state, and FIG. 3 is an explanatory view showing a state of seam welding.

In the electrode structure for seam welding according to the present invention, in the electrode structure in which the intermediate portion of the conductive shaft is supported by the bearing and the bearing ring is fitted to the conductive shaft of the bearing portion, the bearing ring is worn. In such a case, the replacement work can be easily performed.

That is, as shown in FIG. 3, the present seam welding machine 1 includes an upper electrode 2 having a disk electrode 2a and a lower electrode 3 having a disk electrode 3a.
Are rotatable around their respective central axes,
The workpiece W sent between the two disk electrodes 2a and 3a is continuously welded while being pressed, and the present electrode structure is adopted as a structure on the lower electrode 3 side.

As shown in FIGS. 1 and 2, the lower electrode 3 includes first and second conductive shafts 4 and 5, which are divided into two parts.
A bearing for rotatably supporting the first conductive shaft, and a pressing plate for positioning and fixing the first conductive shaft to the bearing;
The bearing ring 6 is fitted on the outer peripheral surface of the first conductive shaft 4 corresponding to the positions of the bearing 7 and the holding plate 8. The disk electrode 3a is
The first conductive shaft 4 is detachably attached to a tip portion of the first conductive shaft 4 by a bolt or the like.

The divided portion of the first conductive shaft 4 and the second conductive shaft 5 is formed into a screw type, and a male screw portion 4t formed on the base end side of the first conductive shaft 4 It can be screwed into a female screw hole 5s provided at the tip. The direction of the screw is such that the direction of rotation of the disk electrode 3a during welding matches the direction in which the screw is tightened.

A fitting portion 4k for fitting the bearing ring 6 is provided near the position of the male screw portion 4t of the first conductive shaft 4.
Are provided, and the bearing 7 and the holding plate 8 are provided corresponding to the position of the fitting portion 4k. Then, as shown in FIG. 2, after the bearing ring 6 is fitted to the fitting portion 4 k of the first conductive shaft 4, the upper part of the bearing ring 6 is positioned by the holding plate 8, and both ends of the holding plate 8 are positioned. Is fixed to the bearing 7.

The base end of the second conductive shaft 5 is connected to the rotating part 9 by a plurality of bolts 10.

In the electrode structure on the lower electrode 3 side as described above, as shown in FIG. 3, a welding portion of the workpiece W is sandwiched between the disk electrodes 2a, 3a, and the disk electrodes 2a, 3a are sandwiched.
The workpiece W is moved and welded continuously while pressing the welded portion of the workpiece W while rotating the workpiece. Particularly, the bearing ring 6 to which a load is easily applied from the bearing 7, the disk electrode 3a, etc. Are severely worn, and it is necessary to replace these worn products in order to perform accurate welding.

The procedure for replacing the bearing ring 6 with the electrode structure of the lower electrode 3 will now be described.
The holding plate 8 on the lower electrode 3 side is removed, and the first conductive shaft 4 is removed.
Is rotated to separate from the second conductive shaft 5, and then the bearing ring 6 is extracted. At this time, since the first conductive shaft 4 and the second conductive shaft 5 are of a screw type, removal is easy.

Next, a new bearing ring 6 is inserted into the fitting portion 4k.
After fitting, the male screw portion 4t of the first conductive shaft 4 is screwed into the female screw hole 5s of the second conductive shaft 5 and joined, and the bearing ring 6 is pressed down by the pressing plate 8 so that the bearing 7 is pressed. , The replacement work is completed. By the way, before fixing with the holding plate 8, the disk electrodes 2a, 3a
It is convenient to replace the new parts with new ones, since later adjustments and the like can be omitted.

Then, when welding is started, the disk electrodes 2a,
The precision of welding can be improved by eliminating the misalignment of 3a and the welding quality can be improved. However, even if a pressing force is applied to the workpiece W by the disk electrode 3a at the time of welding, the male screw portion 4t is a bearing. 7, there is no problem that a large load is directly applied to the male screw portion 4t. On the other hand, the first conductive shaft 4 and the second conductive shaft 5
When the divided portion is located forward of the bearing 7, when a pressure is applied to the workpiece W by the disk electrode 3a, the reaction force is directly applied to the male screw portion 4t, which is disadvantageous in terms of durability. Become. Further, since the tightening direction of the male screw portion 4t and the female screw hole 5s coincides with the direction in which the disk electrode 3a rotates during welding, there is no problem that the connection between the two is loosened during welding.

The present invention is not limited to the above embodiment. Those having substantially the same configuration as those described in the claims of the present invention and having the same functions and effects belong to the technical scope of the present invention. For example, the specific structure of the lower electrode 3 and the like are merely examples, and the male screw portion 4t and the female screw hole 5s may be in opposite directions.

[0021]

As described above, the electrode structure for seam welding according to the present invention has a structure of a seam welding electrode in which a disk electrode is freely attachable to the tip of a conductive shaft rotatably supported by a bearing. In the above, since the conductive shaft can be divided on the rear side of the bearing, for example, the work of replacing a bearing ring fitted to the bearing portion becomes easy, and the operability of the equipment is improved. In addition, by making it possible to divide on the rear side of the bearing, even if, for example, a screw-type division or coupling method is adopted, it is possible to suppress an excessive load from being applied to the divided screw portion during welding, and to improve durability. Problems such as reduction can be prevented. Further, in the present invention, the dividing structure of the conductive shaft is made to be a screw type, so that the division and the coupling are further facilitated, and the work of replacing the worn parts is further facilitated.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a lower electrode employing a seam welding electrode structure according to the present invention.

FIG. 2 is a longitudinal sectional view of an assembled state.

FIG. 3 is an explanatory view showing a state of seam welding;

FIG. 4 is a perspective view of a conventional seam welding machine.

FIG. 5 is an explanatory view of a conventional electrode structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Seam welding machine, 2 ... Upper electrode, 3 ... Lower electrode, 3a
... disk electrode, 4 ... first conductive shaft, 4t ... male screw part,
5: second conductive shaft, 5s: female screw hole, 6: bearing ring, 7: bearing.

Claims (2)

[Claims] 1. A seam welding electrode structure in which a disk electrode is detachably attached to a distal end of a conductive shaft rotatably supported by a bearing, wherein the conductive shaft is located rearward of the bearing. An electrode structure for seam welding, characterized in that it can be divided. 2. The electrode structure for seam welding according to claim 1, wherein the divided structure of the conductive shaft is a screw type.