JPH0511033Y2 - - Google Patents

Description

[Detailed description of the invention] A. Purpose of the invention (1) Industrial application field This invention consists of a pair of electrode shafts rotatably supported by a support member, and a pair of electrode shafts each fixed to the tip of the electrode shafts. This invention relates to a cooling device for an electrode head in a seam welding machine, which comprises an electrode roller and an electrode roller.

(2) Prior Art Conventionally, as a cooling device for an electrode head in such a seam welding machine, those described in, for example, Japanese Unexamined Utility Model Publication No. 53-138628 and Japanese Utility Model Application No. 51-23022 are known.

(3) Problems that the invention aims to solve However, the one described in the previous publication only has a coolant circulation passage in the electrode shaft to cool the inside of the electrode shaft. The surface or the object to be welded cannot be sufficiently cooled, and therefore, during welding, excessive joule heat is generated in the welding area, which may result in welding defects at the welding area. In addition, the structure described in the later publication has a structure in which cooling liquid is applied directly to the electrode roller from the outside to cool it, so contrary to the above, the inside of the electrode shaft cannot be sufficiently cooled, and the electrode roller is cooled. There is a problem in that the life of the electrode head is shortened due to the deterioration of the bearing part of the shaft.

The present invention was developed in view of the above circumstances, and is designed to cool the electrode head from the inside and outside, and to cool the object to be welded at the same time, thereby preventing the generation of excessive joule heat.
It is an object of the present invention to provide a cooling device for an electrode head in the seam welding machine, which can accurately weld objects to be welded and extend the life of the electrode head.

B. Structure of the invention (1) Means for solving the problem In order to achieve the above object, the present invention has an electrode shaft that is rotatably supported by a support member, and an inner end surface that is joined to the tip of the electrode shaft. A seam welding machine in which a pair of electrode heads each having a flat plate-shaped electrode roller are arranged in parallel, and a workpiece to be welded is sandwiched between the outer peripheries of the electrode rollers of both electrode heads and welded. In the cooling device, first and second coolant passages are formed independently of each other along the axial direction of each of the electrode shafts, and cooling liquid supply holes are communicated with the entrances of these passages. The tip portion is formed to have a larger diameter than the intermediate portion thereof, and an internal cooling passage with an open outlet is defined between the bonding surface of the large diameter tip portion and the electrode roller, and extends along the bonding surface. , the outlet of the first coolant passage is communicated with the internal cooling passage, and the outlet of the second coolant passage is directed along the outer end surface of the electrode roller and toward the contact portion between the roller and the workpiece to be welded. The nozzle body is characterized in that it has a nozzle opening that opens so as to communicate with the nozzle body supported by the support member.

(2) Effect The coolant led from the coolant supply hole to the first coolant passage flows into the internal cooling passage connected to the outlet of this passage and cools the joint surface between the electrode roller and the electrode shaft. The coolant led from the liquid supply hole to the second coolant passage is discharged from the nozzle body continuous to the outlet of the passage along the outer end surface of the electrode roller and toward the contact area between the roller and the workpiece. hand,
The outer end surface of the roller and the welded part of the workpiece are quickly cooled.

(3) Example Hereinafter, an example of the present invention will be explained with reference to the drawings.As shown in Fig. 1, a seam welding machine S
is an electrode shaft 1 rotatably supported by a support member 5.
and an electrode roller 2 whose inner end surface is joined to the tip end 1a of the electrode shaft 1. A pair of electrode heads 3, 3 are arranged vertically in parallel. The welding part of the object W to be welded is sandwiched between the outer circumferential surfaces of the parts 2 and 2, pressure is applied, and electricity is applied to the welding part to perform welding.

Since the structures of the pair of electrode heads 3, 3 are exactly the same, one of the electrode heads 3 will be explained below.The tip portion 1a of the electrode shaft 1 is formed to have a larger diameter than the intermediate portion. The disk-shaped electrode roller 2 is fixed to the end face of the portion 1a with a bolt 6. The electrode shaft 1 is freely supported by a support cylinder 5 as a support member via a pair of front and rear bearings 4a, 4b, and a cover body 5a fixed to the base end of the support cylinder 5 is attached to the base end of the support cylinder 5. It is attached via seals 7a and 7b. A screw hole 8 is formed at the base end of the lid 5a, and a blind plug 9 is screwed into the screw hole 8. Further, a cooling liquid supply hole 10 for introducing cooling liquid into the electrode head 3 is bored in the side surface of the lid 5a.

A first coolant passage 11 is formed passing through the electrode shaft 1 along its axial direction, and a tube having a smaller diameter than this first coolant passage 11 and having a second coolant passage 12 inside thereof is formed. Body 13 is inserted. The proximal end of the tubular body 13 is supported by a mounting hole 9a formed at the distal end of the blind stopper 9, and the distal end of the tubular body 13 is connected to the first
The sleeve 16 is inserted into the tip of the coolant passage 11 and is rotatably supported by a sleeve 16 fixed to the electrode roller 2 with screws 15 . On the proximal side surface of the tube body 13, a second
Coolant introduction hole 12 as an inlet of the coolant passage 12
a is bored, and this introduction hole 12a and the first
The inlets 11a of the coolant passages 11 are both communicated with the coolant supply hole 10. Further, a nozzle body 17 having a nozzle 17a that opens along the outer end surface of the electrode roller 2 and toward the contact area between the roller 2 and the workpiece W to be welded is fixed to the tip opening of the tube body 13. , the second coolant passage 12 is connected to this nozzle body 17.
communicated internally.

As shown in FIGS. 2 and 3, a notched circular internal cooling passage 18 is provided between the joint surface between the large-diameter tip 1a of the electrode shaft 1 and the electrode roller 2, and extends along the joint surface. Formed almost concentrically. The entrance 18b of this internal cooling passage 18 is a branch passage 2 bored in the electrode shaft 1.
0 to the first coolant passage 11. The tip of the internal cooling passage 18 is a dead end portion 18
a, and this dead end portion 18a communicates with a coolant discharge hole 19 formed in the electrode roller 2 and is opened to the outside. O-rings 21a and 2 are provided on the inner and outer peripheral portions of the internal cooling passage 18 to prevent liquid leakage from the boundary between the large diameter portion 1a and the electrode roller 2.
1b is interposed.

Next, the operation of this embodiment will be explained.

When the cooling liquid is supplied to the electrode head 3 from the cooling liquid supply hole 10 of the lid body 5a during seam welding, a part of the cooling liquid is introduced into the internal cooling passage 18 from the inlet 11a via the first cooling liquid passage 11 and the branch passage 20. is,
After circulating through the passage 18, the coolant is discharged to the outside through the coolant discharge hole 19. At this time, the cooling liquid cools the joint between the electrode roller 2 and the large-diameter tip 1a of the electrode shaft 1 from inside the electrode head 3 over substantially the entire circumference thereof. The remaining coolant flows through the second coolant passage 12 inside the pipe body 13 from the introduction hole 12a to the nozzle body 1.
It is emitted from the nozzle 17a of No. 7, flows along the surface of the electrode roller 2, reaches the objects W to be welded, and quickly cools them. Therefore, the tip of the electrode head 3, which is easily heated by Joule heat during seam welding, is efficiently cooled from inside and outside to prevent deterioration of the bearing 4a, O-rings 21a, 21b, O-rings 14a, 14b, sleeve 16, etc. This can be prevented and the life of the electrode head 3 can be extended. Furthermore, it is possible to prevent excessive joule heat from being generated in the welded portion and to cause welding defects in the welded portion, thereby allowing accurate welding to be performed.

C. Effects of the invention As described above, according to the invention, the cooling liquid led from the cooling liquid supply hole to the first cooling liquid passage flows into the internal cooling passage connected to the outlet of this passage, and flows between the electrode roller and the electrode shaft. On the other hand, the cooling liquid led from the cooling liquid supply hole to the second cooling liquid passage is directed from the jet port of the nozzle body connected to the outlet of the passage along the outer end surface of the electrode roller and toward the second cooling liquid passage. The electrode head is emitted toward the contact area between the roller and the workpiece, and the outer end surface of the roller and the welding part of the workpiece can be quickly cooled. The welded part of the workpiece can also be directly cooled, and the tip of the electrode head and the welded part can be prevented from overheating due to joule heat during seam welding, thus extending the life of the electrode head. It is possible to always accurately weld objects to be welded.

In particular, by dividing the cooling liquid passage in the electrode head into a first cooling liquid passage connected to the internal cooling passage and a second cooling liquid passage connected to the nozzle body, each of the internal cooling passage and the nozzle The cross-sectional areas of the first and second coolant passages can be individually and accurately set according to the required characteristics. Furthermore, the tip of the electrode shaft is formed to have a larger diameter than the middle portion thereof, and the internal cooling passage extending along the bonding surface is defined between the large-diameter tip and the electrode roller. , the internal cooling passage can be easily formed and processed, and the degree of freedom in setting the position and shape of the passage can be increased. Furthermore, since the electrode roller and the nozzle body can be made as separate parts and the outer peripheral surface of the roller and the nozzle orifice can be placed apart from each other, the structure of the electrode roller itself, which is a consumable item, can be simplified as much as possible to reduce costs. Moreover, even if the electrode roller is brought into strong pressure contact with the workpiece, there is no risk of the nozzle body being compressed or deformed or damaged.

[Brief explanation of drawings]

The drawings show an embodiment of the device according to the present invention, in which Fig. 1 is a longitudinal sectional view of one electrode head of a seam welding machine, Fig. 2 is a partially cutaway view taken along the line in Fig. 1, and Fig.
The figure is a cross-sectional view taken along the line -- in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line -- in FIG. S... seam welding machine, 1... electrode shaft, 2... electrode roller, 3... electrode head, 5... support cylinder as support member, 10... coolant supply hole, 11,
12...First and second coolant passages, 11a...Inlet, 12a...Introduction hole as an inlet, 17...Nozzle body, 17a...Spout port, 18...Internal cooling passage.

Claims (1)

[Scope of utility model registration request] Electrode shaft 1 rotatably supported by support member 5
and a flat electrode roller 2 whose inner end surface is joined to the tip 1a of the electrode shaft 1. In a cooling device for an electrode head in a seam welding machine which welds a workpiece W between the electrodes, each electrode shaft 1 has first and second cooling fluid passages 11 along its axial direction.
12 are formed independently of each other, and these passages 1
Coolant supply holes 1 are provided at the inlets 11a and 12a of 1 and 12.
0 are in communication with each other, and the tip portion 1a of each electrode shaft 1 is formed to have a larger diameter than the intermediate portion thereof, so that the large diameter tip portion 1
An internal cooling passage 18 with an open outlet is defined between the joint surface of the electrode roller 2 and the electrode roller 2 and extends along the joint surface, and an outlet of the first cooling liquid passage 11 is provided in the internal cooling passage 18. communication, and also the second
It is supported by the support member 5 and has a spout 17a that opens the outlet of the coolant passage 12 along the outer end surface of the electrode roller 2 and toward the contact area between the roller 2 and the workpiece W to be welded. A cooling device for an electrode head in a seam welding machine, characterized in that the cooling device communicates with a nozzle body 17.