JPH0428699Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is a welding device for long structures, in particular, welding that extends in the longitudinal direction using a welding machine installed at a fixed position while the workpiece is transported in the longitudinal direction by a conveyor. This invention relates to a grounding means for a welding device for welding wires.

Prior Art In order to streamline welding work on welding lines extending longitudinally of long structures such as columns and beams of buildings or welded steel pipes, welding workpieces are conveyed longitudinally using a conveyor such as a roller conveyor, and A welding device is used that performs welding in a fixed position by a welding machine installed at a position.

When welding, it is necessary to ground the workpiece, but if welding is carried out while moving the workpiece, it is necessary to devise a method for grounding the workpiece.
Conventionally, when welding such a long workpiece while moving it in the longitudinal direction, it was either attached to the welding end tab attached to the end of the workpiece with a clamp, or directly attached to the workpiece using various devices. It was a method of fixing the ground. in this case,
Since the ground wire moves together with the workpiece, install a long enough ground wire so that the ground wire can follow this, store it, and provide room on the side of the conveyor for it to move. I needed to leave it there.

It has also been done to ground the roller conveyor, but in this case the position of the ground constantly changes, making it difficult to perform stable welding. Further, since neither the workpiece nor the conveyor roller are in complete contact with each other with their metal surfaces, continuous arc strikes are likely to occur.

Therefore, a grounding member is brought into sliding contact with the workpiece to obtain the ground, and a grinding device is provided upstream of the workpiece in the conveying direction and within the range of the ground contact width so that it can be pressed against the workpiece. Although there are examples of improving the surface condition of objects, even in such cases, grounding occurs at sliding contact parts, and defects such as arc strikes are unavoidable.

Purpose The present invention eliminates the above-mentioned drawbacks of welding equipment for long structures in which workpieces are welded in a fixed position while being transported by a conveyor. It is an object of the present invention to provide a welding device for long structures that does not cause defects or arc strike-like defects.

Means for Achieving the Objective In order to achieve the above objective, the present invention uses a welding machine installed at a fixed position to weld a welding line extending in the longitudinal direction while conveying a long structure in the longitudinal direction by a conveyor. , a grounding member capable of resiliently contacting the structure to be welded at a fixed position near the welding machine, and a grounding member having a contact width of the grounding member on the upstream side in the conveyance direction of the structure to be welded. In a long structure welding device that includes a grinding device that can be pressed against the structure, the grounding member has an endless belt having a resilient force whose inner peripheral surface is supported by a plurality of support rollers, and the A crawler-like member that is held on the outer peripheral surface and is configured by connecting a plurality of copper plate flat plates to each other, and sliding on the copper plate flat plate of the crawler-like member at a position other than the contact portion of the crawler-like member with the structure to be welded. and an electrode connected to a ground wire.

Effect With this configuration, the contact range of the grounding member is such that before the grounding member makes contact,
Since the copper plate of the grounding member and the structure to be welded are ground by a grinding device and the black scale has been removed, the metal surfaces of the grounding member and the structure to be welded come into elastic contact with each other, and since the grounding member has a crawler structure, Mutual movement does not occur between the flat copper plate of the grounding member and the surface of the structure to be welded with which it comes into contact, and a welding device that does not generate arc strikes due to generation of grounding can be obtained.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to welding a joint between webs on both sides of a box-shaped column and an upper flange. The box-shaped column 10 consists of a lower flange 1, webs 2 and 3 on both sides, an upper flange 4, and a diaphragm 5 provided at an appropriate pitch inside the flange.The lower flange 1 and the webs 2 and 3 are temporarily attached. The diaphragm 5 is placed in a predetermined position and temporarily attached, and the upper flange 4 is placed on top of it.
Welding of the joint between the webs 2 and 3 and the upper flange 4 is carried out by placing the workpiece on a roller conveyor 6 and conveying it in the longitudinal direction at a predetermined speed, while the workpiece is attached to a welding machine fixed at a fixed position. , welding is carried out by a welding torch 7 held in a fixed position. In order to obtain grounding in this case, an arm 11 extending from the welding machine is equipped with a grounding member 12 that can elastically contact the upper surface of the upper flange 4, and a grounding member 12 located upstream of the upper surface of the upper flange 4 in the direction of conveyance of the workpiece. A grinder 13 is provided within a contact width range of the workpiece and grinds the surface of the workpiece using a power source (not shown).

The grounding member 12 is, for example, as shown in FIG.
A flat plate 15 made of a copper plate is fixed to the outer periphery of an endless belt 14 made of a leaf spring to form a crawler.The inner surface of the plate is supported by a roller 17 supported by a spring 16 held by an arm 11, and the lower surface of the crawler is attached to the workpiece 10. An electrode plate 19 connected to a ground wire 18 is pressed to the top surface of the crawler.

Since this device has the above-described configuration, when the workpiece 10 moves on the roller conveyor 6 in the direction shown by the arrow in FIG. The copper plate 15 rotates in place while being in pressure contact with the upper surface of the upper flange 4 without relative movement, and the copper plate 15 slides into contact with the electrode 19 on the upper surface of the crawler, thereby performing grounding.
The area where the grounding member 12 of the upper flange makes contact is ground by a grinder 13 installed upstream of the area, and the black crust is removed and the metal skin is exposed, so a good electrical conduction state is obtained and the contact occurs when contact occurs. Arc strike-like surface defects are prevented.
Further, since the grounding member 12 is fixed in position with respect to the welding machine, there is no need to extend the grounding wire and route it around as the workpiece moves.

The ground member is not limited to the configuration of the above embodiment, and a rubber tire filled with compressed air may be used instead of the endless belt made of a leaf spring.

Furthermore, the grounding device according to the present invention is not limited to temporary welding between the web and flange of a box-shaped column as explained in the embodiment, but can also be used for welding at a fixed position while moving a long workpiece in the longitudinal direction. It can be effectively used for grounding when welding various workpieces such as welded steel pipes and rectangular steel pipes to which welding lines extending in the longitudinal direction are welded by machines.

Effects As described above, according to the present invention, grounding can be easily and reliably established when automatically welding a welded joint extending in the longitudinal direction of a long structure while the workpiece is conveyed in the longitudinal direction by a conveyor. This makes it possible to prevent arc strike-like surface defects from occurring on the workpiece.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment in which the present invention is applied to welding a weld line in the longitudinal direction of a box-shaped column, and FIG. 2 is a perspective view showing an example of the configuration of the grounding member. 6...Roller conveyor, 7...Welding torch, 1
0... Workpiece (long structure), 12... Earth member, 13... Grinder, 14... Endless belt made of leaf spring, 18... Earth wire.

Claims (1)

[Scope of claim for utility model registration] In order to weld a weld line extending in the longitudinal direction while conveying a long structure in the longitudinal direction by a conveyor,
A welding machine installed at a fixed position, a ground member capable of elastically contacting the structure to be welded at a fixed position near the welding machine, and a grounding member located upstream of the welding structure in the direction of conveyance of the structure to be welded. In the welding device for a long structure, the grounding member has a grinding device that can be pressed against the structure within a contact width of the grounding member. A powerful endless belt, a crawler-like member held on its outer circumferential surface and configured by connecting a plurality of copper flat plates to each other, and a crawler-like member at a position other than the contact portion of the crawler-like member with the structure to be welded. A welding device characterized by comprising an electrode that is in sliding contact with a flat copper plate of a member and connected to a ground wire.