JP3193853U - End tab for arc welding - Google Patents

Abstract

An end tab is provided that can generate a stable arc between an end tab and a welding wire at an arc welding start location and prevent occurrence of welding defects at the arc welding start location. SOLUTION: An open front end surface of a base material faces another base material, a groove groove is formed therebetween, and a welding backing material is arranged over both base materials so as to form a bottom portion of the groove groove. When welding both base metals by sequentially laminating a molten metal layer in the groove groove portion by arc welding, it is installed in contact with the side surface of at least one base material outside the one end portion of the groove groove portion. The end tab 10 is made of ceramic having a welding use surface 14 formed at a depressed position on one surface side and a base material contact surface 18 formed on a side portion of the welding use surface via a stepped surface 16. And a metal thin film layer 20 having a thickness of 10 to 500 μm formed in a lower portion of the tab body, which is a portion where the initial layer of the molten metal layer is located when the end tab is installed at a predetermined position and welded. It comprises. [Selection] Figure 1

Description

  The present invention relates to an end tab used together with a welding backing metal when welding a base material to another base material by arc welding such as MAG (Metal Active Gas) welding.

  In assembling a building steel frame, various base materials are welded to each other by an automatic arc welding machine or a semi-automatic arc welding machine. As an example of such a conventional welding method, a case where two base materials such as beam flanges are welded to each other using a welding backing metal and an end tab will be described. The end of one beam flange is inclined by groove processing. The end face is formed as an open end face, and the end face of the other beam flange is formed as a vertical end face. Both beam flanges are arranged so that the open front end surface of one beam flange faces the vertical end surface of the other beam flange and a groove groove having a substantially V-shaped cross section is formed therebetween. A welding backing metal is applied between the bottom surfaces of the end portions so as to be the bottom portion of the groove portion. The welding backing metal is longer than the length of both groove grooves, and both ends of the welding backing metal for this purpose are projected from the side surfaces of the ends of both beam flanges. The end tab is disposed so as to close the end of the groove portion.

  Next, the automatic arc welding machine or the semi-automatic arc welding machine is operated, whereby the feeding head for the welding wire is moved to one end portion of the groove groove portion, that is, the first end portion side, so that the predetermined height is reached. Is positioned. Next, when the welding wire is fed from the feeding head and the tip thereof is brought into contact with the bottom portion on the first end side of the groove portion, a predetermined voltage is applied between the base material side and the welding wire. Therefore, an excessive short-circuit current flows during that time. When a short-circuit current is passed through the welding wire, its tip melts for heating and an arc is generated in the meantime, thereby starting the welding operation. That is, while the welding wire is fed from the feeding head at a predetermined feed amount, the feeding head is moved toward the other end side of the groove groove portion, that is, the second end portion side, thereby the groove groove portion. An initial layer of molten metal, that is, a first molten metal layer is formed at the bottom of the substrate. When the feeding head reaches the second end side of the groove portion, the feeding head is raised by a predetermined amount, and then the movement of the feeding head is reversed. That is, the feeding head is moved from the second end portion side of the groove portion toward the first end portion thereof, thereby forming a second molten metal layer on the first molten metal layer. The By repeating such a welding operation, a molten metal layer is sequentially laminated in the groove groove portion, whereby the groove groove portion is filled with the molten metal to form a weld bead.

  In the above-described example, the molten metal layer is sequentially laminated while reciprocating the arc between the first and second ends of the groove groove portion. However, after the first molten metal layer is formed, the arc The generation is temporarily stopped, and the feeding head is returned from the second end side of the groove groove to the first end side, where an arc is generated again to move toward the second end of the groove groove. Then, the welding operation may be resumed to form the second molten metal layer on the first molten metal layer.

  As described above, when the molten metal layer is sequentially laminated in the groove portion having a substantially V-shaped cross section, the width of the molten metal layer increases as the molten metal layer becomes an upper layer. Therefore, in order to make the thickness uniform when each molten metal layer is formed, when the feeding head is moved between the first and second end sides of the groove groove, the feeding head is moved to the groove groove. The arc is shifted in a zigzag manner along the groove portion by oscillating in the width direction, and the amplitude of the zigzag transition of such an arc is gradually increased as the molten metal layer becomes an upper layer.

  By the way, in the conventional arc welding method described above, the end tab is made of steel or ceramic. In the case of a steel end tab, an arc is also generated between the end tab and the welding wire at the arc welding start location, that is, at the end tab installation location, so that the occurrence of welding defects near the end tab can be kept relatively low. It is. On the other hand, in the case of a ceramic end tab, no arc can occur between the end tab and the welding wire at the arc welding start location, that is, where the end tab is installed. This causes a problem that welding defects are likely to occur.

  By the way, when the welding of both base materials is completed, the end tabs are removed, but the steel end tabs are firmly joined to both base materials by welding beads, so that the removal work is troublesome and troublesome. It will be a thing. On the other hand, the ceramic end tab can be easily removed by applying an impact using an appropriate tool. In short, in the case of a steel end tab, there is an advantage that the occurrence of welding defects can be kept relatively low, but on the other hand, there is a drawback that the removal work of the end tab is troublesome and troublesome, whereas the end tab made of ceramic is difficult. In some cases, there is a disadvantage that welding defects are likely to occur, but there is an advantage that the removal work of the end tab is easy.

  The arc welding method of Patent Document 1 is welded to the tab in the arc welding method in which welding is performed by attaching a tab made of a nonmetallic solid inorganic material that forms a surface perpendicular to the weld line at a welding start position or end position. A metal mesh or metal fiber mat made of the same kind of metal as the base metal is sandwiched and fixed between the base metal, and welding is performed.

In this arc welding method, it is expected that the arc will be stabilized to some extent because of the action of the metal mesh or metal fiber mat, so that the pre-treatment and post-treatment of welding are not troublesome.
However, in the method disclosed in Patent Document 1, since a metal mesh or metal fiber mat is used as described above, a welding rod is caught on the mat or the like, workability is poor, and conductivity is not stable. There's a problem.

JP 2000-117490 A

  Accordingly, an object of the present invention is a ceramic end tab used when welding a base material to another base material by arc welding such as MAG (Metal Active Gas) welding, and the end tab and the weld at the arc welding start location. By providing a welding backing that can generate an arc between wires and stabilize the arc when the arc occurs, thereby preventing the occurrence of weld defects generated at the arc welding start point. is there.

The object is achieved by the end tab of the present invention having the following configurations (1) to (6).
(1)
A grooved base material is faced to another base material, a groove groove is formed between them, and a backing for welding is formed over both the base materials so as to form the bottom of the groove groove. When welding the both base metals by sequentially laminating a molten metal layer on the groove grooves by arc welding and welding at least one of the base metals at one end of the groove grooves An end tab that is installed in contact with the side surface of the base material of
A welding use surface formed in a recessed position on one surface side, and a base material contact surface that is formed on at least one side portion of the welding use surface via a stepped surface and contacts an end surface of the base material. When the tab body made of ceramic and the end tab are installed at the predetermined position, the welding use surface, the step surface, and the base material contact of the tab body, which is a portion corresponding to the initial layer of the molten metal layer An end tab comprising: a metal thin film layer formed continuously in a lower portion of the surface, wherein the metal thin film layer has a thickness of 10 to 500 μm.
(2)
The end tab according to (1), wherein the metal thin film layer has a thickness of 30 to 100 μm.
(3)
The end tab according to (1) or (2), wherein the metal thin film layer has a height corresponding to at least the thickness of the initial layer of the molten metal layer.
(4)
In the end tab according to any one of (1) to (3), the base material contact surface is formed only on one side of the welding use surface, and the side surface of the tab main body contacts the surface of the other base material. An end tab characterized in that the metal thin film layer is also formed on this side surface.
(5)
The end tab according to any one of (1) to (4), wherein the other surface side of the tab body is formed symmetrically with the one surface side.
(6)
The end tab according to any one of (1) to (5), wherein the metal thin film layer is formed of iron, aluminum, nickel, copper, gold, silver, brass or beryllium copper. .

  According to the end tab of the present invention, an arc can be generated at the location of the metal thin film layer of the end tab at the start of welding, so that it is possible to prevent the occurrence of welding defects and to remove the original function of the ceramic end tab, that is, removal after welding. It also has the function of ease. Furthermore, since it is in a layer state, the surface can be flattened, the thickness can be made uniform, workability is good, and the conductivity is stable.

It is a perspective view which shows embodiment of the end tab by this invention. It is a perspective view which shows the beam flange and diaphragm which should be arc-welded using the end tab of FIG. 1, and the backing material for welding applied to these.

FIG. 1 is a perspective view of an end tab 10 according to an embodiment of the present invention.
As shown in FIG. 2, the end tab 10 is formed with a groove groove portion between the open end surface of a base material (beam portion) M1 that has been grooved facing another base material (diaphragm portion) M2. The welding backing material B is disposed across the two base materials so as to form the bottom of the groove groove portion, and a molten metal layer is sequentially laminated on the groove groove portion by arc welding to It is an end tab that is installed in contact with the side surface of at least one of the two base metals on the outside of one end of the groove groove when welding.

  The end tab 10 includes a tab main body 12, and the tab main body 12 has a welding use surface 14 formed at a depressed position on one surface side, and a step surface 16 on at least one side portion of the welding use surface 14. And a base material contact surface 18 that contacts the end surface of the base material. When the tab main body 12 and the end tab 10 are installed at the predetermined position (operation position) shown in FIG. 2, the tab main body 10 is a portion corresponding to an initial layer of the molten metal layer. A metal thin film layer 20 formed continuously is provided in a lower portion of the welding use surface 14, the step surface 16, and the base material contact surface 18. The metal thin film layer 18 may also be provided on the side surface 22 of the tab body 12 that contacts the base material M2.

The thickness of the metal thin film layer is 10 to 500 μm, preferably 30 to 100 μm. If the thickness of the metal thin film layer 18 is less than the above range, it burns before the occurrence of the arc, while if it exceeds the above range, there is a portion that remains as it is, resulting in poor penetration.
The metal thin film layer 18 preferably has a height corresponding to at least the thickness of the first layer of the molten metal layer.

  The end tab 10 shown in FIG. 1 shows a base material contact surface provided only on one side of the welding use surface 14, but a base material contact surface may be provided on both sides of the welding use surface 14. The other surface side of the tab body may be formed symmetrically with the one surface side.

  The metal thin film layer 18 is preferably formed of iron, aluminum, nickel, copper, gold, silver, brass or beryllium copper.

  The tab body 12 is configured by, for example, forming a ceramic raw material into a shape as shown in the figure and then performing a sintering process, and the metal thin film layer 18 is formed by attaching or plating a thin film made of steel, for example. It is formed by. It can be configured by machining the material appropriately according to the form of the tab body 11.

  The end tab 10 is appropriately fixed to the welding backing material B using an appropriate clamping means or an adhesive (not shown). The base material and the welding backing metal B are appropriately fixed by appropriate clamping means (not shown) as required.

  According to the end tab of the present invention, an arc can be generated at the location of the metal thin film layer of the end tab at the start of welding, so that it is possible to prevent the occurrence of welding defects and the original function of the ceramic end tab, that is, removal after welding It also has the function of ease. Furthermore, since it is in a layer state, the surface can be flattened, the thickness can be made uniform, workability is good, and the conductivity is stable.

10: End tab 12: Tab body 14: Welding use surface 16: Base material contact surface 18: Metal thin film layer 20: Side surface M1, M2 of tab body 12: Base material B: Backing material for welding

Claims (6)

A grooved base material is faced to another base material, a groove groove is formed between them, and a backing for welding is formed over both the base materials so as to form the bottom of the groove groove. When welding the both base metals by sequentially laminating a molten metal layer on the groove grooves by arc welding and welding at least one of the base metals at one end of the groove grooves An end tab that is installed in contact with the side surface of the base material of
A welding use surface formed in a recessed position on one surface side, and a base material contact surface that is formed on at least one side portion of the welding use surface via a stepped surface and contacts an end surface of the base material. When the tab body made of ceramic and the end tab are installed at the predetermined position, the welding use surface, the step surface, and the base material contact of the tab body, which is a portion corresponding to the initial layer of the molten metal layer An end tab comprising: a metal thin film layer formed continuously in a lower portion of the surface, wherein the metal thin film layer has a thickness of 10 to 500 μm.   The end tab according to claim 1, wherein the metal thin film layer has a thickness of 30 to 100 μm.   3. The end tab according to claim 1, wherein the metal thin film layer has a height corresponding to at least the thickness of the initial layer of the molten metal layer.   The end tab according to any one of claims 1 to 3, wherein the base material contact surface is formed only on one side of the welding use surface, and the side surface of the tab main body is in contact with the surface of the other base material. An end tab characterized in that the metal thin film layer is also formed on this side surface.   The end tab according to any one of claims 1 to 4, wherein the other surface side of the tab body is also formed symmetrically with the one surface side. The end tab according to any one of claims 1 to 5, wherein the metal thin film layer is formed of iron, aluminum, nickel, copper, gold, silver, brass or beryllium copper.

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