Welding method

Abstract

To provide a welding method capable of suppressing the flow of molten metal into a hole part at welding while avoiding a decrease in the working efficiency of welding.SOLUTION: The welding method is to join, by welding: a curved surface corner portion 1b of a square steel pipe 1 which is a first member; and an edge portion 2b in a beam-connecting plate material 2 which is a second member having a bolt hole 2c in the vicinity of the edge portion 2b, and in which the edge portion 2b protrudes toward the curved surface corner portion 1b side, and a part of a lower end of the bolt hole 2c facing the curved surface corner portion 1b and positioned in an unclosed state. Therein a rod-like member 3 is welded in a state of being inserted into the bolt hole 2c.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a welding method that can be used for welding an end plate or the like to a square steel pipe column or the like. [Background technology]

[0002] Patent Document 1 discloses a column-beam connection method in which a reinforcing plate has a width approximately the same as the outer width of a square steel pipe column, and welding is performed in the gaps between the left and right edges of the reinforcing plate and the outer curved corners of the square steel pipe column. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-162554 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a configuration in which a bolt hole is formed in a beam connection plate material such as the reinforcing plate or end plate at a position close to the outer curved corner of the square steel pipe column, and part of the lower end of the bolt hole faces the curved corner and is not closed, if welding is performed to obtain deep penetration by targeting the back side between the beam connection plate material and the curved corner (near the part of the bolt hole facing the curved corner), there is a risk of molten metal flowing into the bolt hole.

[0005] On the other hand, in order to prevent the molten metal from flowing into the bolt hole, there is a measure to temporarily screw a bolt into the bolt hole. However, such a measure has a risk that the molten metal will bond the bolt to the beam connection plate material, making it difficult to remove the bolt from the bolt hole. In such a case, if the bolt is forcibly removed from the bolt hole, the thread of the bolt hole may be damaged. Furthermore, the task of turning the bolt in and out of the bolt hole each time is relatively time-consuming, which reduces the efficiency of the work.

[0006] In view of the above circumstances, an object of the present invention is to provide a welding method capable of preventing molten metal from flowing into a bolt hole during welding while avoiding a decrease in welding efficiency. [Means for solving the problem]

[0007] In order to solve the above-mentioned problem, the welding method of the present invention is a welding method for joining by welding a curved corner portion of a first member to an edge portion of a second member, the edge portion having a bolt hole near the edge portion, the edge portion protruding toward the curved corner portion and a portion of the lower end of the bolt hole facing the curved corner and not closed, characterized in that welding is performed with a rod-shaped member inserted into the bolt hole.

[0008] With the above method, the edge portion and the curved corner portion are welded together while the rod-shaped member is inserted into the bolt hole, so that molten metal can be prevented from flowing into the bolt hole. Furthermore, the operation of inserting and removing the rod-shaped member into and from the bolt hole does not require the rotation of the rod-shaped member, so that it is possible to avoid the decrease in work efficiency that occurs in the past when the bolt must be turned each time, and also to suppress damage to the bolt hole.

[0009] The second member may have a grommet hole near the edge portion, and a grommet rod member may be inserted into the grommet hole and welded.

[0010] The rod-shaped member may be made of a metal having a thermal conductivity of 200 W / m·k or more. This suppresses the temperature rise of the rod-shaped member even if the molten metal that has reached the bolt hole comes into contact with the rod-shaped member, so that the rod-shaped member can be prevented from melting and being joined to the welded portion. Furthermore, if the heat around the welded portion does not escape well, the welded portion may be slowly cooled and an annealed state may occur. However, if the thermal conductivity of the rod-shaped member is high, the heat around the welded portion can escape easily (the temperature does not easily rise), so that the annealed state can be prevented from occurring. Furthermore, if the thermal conductivity of the rod-shaped member is high in this way, it becomes easy to input a large amount of heat to the welded portion to achieve deep penetration welding.

[0011] The rod-shaped member may be made of metal having a melting point of 1500° C. or more. With this, even if the molten metal that has reached the bolt hole comes into contact with the rod-shaped member, the rod-shaped member will not melt, and therefore the rod-shaped member can be prevented from being joined to the second member.

[0012] The rod-shaped member may be made of a ceramic material, which has a high melting point and does not melt even if the molten metal that has reached the bolt hole comes into contact with the rod-shaped member, thereby preventing the rod-shaped member from melting and being joined to the second member.

[0013] The first member may be a square steel pipe, and the second member may be a beam connecting plate. Effect of the Invention

[0014] The present invention has various advantages, such as preventing a decrease in welding work efficiency while preventing molten metal from flowing into the bolt hole. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a diagram showing a welding method according to an embodiment, and is an explanatory perspective view showing a state in which a beam connection plate, which is a second member, is pre-welded to a flat portion of a square steel pipe, which is a first member. [Diagram 2]FIG. 2 is a diagram showing a welding method according to an embodiment, and is an explanatory diagram showing a cross section of a groove formed between a curved corner portion of a square steel pipe and an edge portion of a beam connection plate material adjacent to the curved corner portion of the square steel pipe. [Diagram 3] FIG. 13 is a cross-sectional explanatory diagram showing a welding method according to an embodiment, illustrating the process of inserting a rod-shaped member into a bolt hole in a beam connection plate and overlapping passes (weld beads) in the groove portion to perform multi-layer welding. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. In this embodiment, as shown in Fig. 1, before actual welding, beam connection plates 2 as second members are placed on adjacent flat portions 1a, 1a of square steel pipes 1 as first members, and ends 2a of each beam connection plate 2 are pre-welded to the flat portions 1a.

[0017] Then, as shown in Fig. 2, actual welding is performed to join the curved corner 1b of the square steel pipe 1 to the edge parts 2b, 2b of each beam connection plate material 2 adjacent to the curved corner 1b, that is, flare welding is performed at the groove part formed by the arc part and the straight part. In this welding, the square steel pipe 1 is placed with its curved corner 1b facing upward. In addition, in this welding, an arc welding machine is used, and the welding wire 5a at the tip of the welding torch 5 of this arc welding machine is directed from above toward the back side of the groove. In addition, the corners of the edge parts 2b, 2b of each beam connection plate material 2 adjacent to the curved corner 1b are chamfered.

[0018] In this welding method, as shown in Fig. 3, in the groove between the curved corner 1b of the square steel pipe 1 and the edge parts 2b, 2b of the beam connection plate material 2, 2, a single weld is performed multiple times without interruption along each edge part 2b, and multi-layer welding is performed. In other words, multiple passes p (weld beads) are formed in the groove to form multiple weld layers.

[0019] Each beam connection plate 2 has a plurality of bolt holes 2c formed at a predetermined interval along the edge portions 2b near the edge portions 2b on both sides (see also FIG. 1). Each edge portion 2b protrudes toward the curved corner portion 1b, and a part of the lower end of the bolt hole 2c faces the curved corner portion 1b and is not closed.

[0020] Each beam connection plate 2 has a grommet hole 2d near the edge portion 2b through which a grommet (not shown) can be passed (see FIG. 1). The square steel pipe 1 also has a grommet hole (not shown) at a position corresponding to the grommet hole 2d. After the grommet is inserted into the grommet hole 2d and moved to adjust the position of the beam connection plate 2, the end portion 2a of the beam connection plate 2 is pre-welded to the flat portion 1a as described above.

[0021] Welding to join the curved corner portion 1b and the edge portion 2b of each beam connection plate 2 is performed with cylindrical metal rod members 3 inserted into the bolt holes 2c and the shim holes 2d to match the respective hole diameters.

[0022] In the welding method of this embodiment, a pass is formed by inserting a rod-shaped member 3 for bolt holes into three bolt holes 2c and a rod-shaped member 3 for a shank hole into a shank hole 2d on the side of the edge portion 2b of the beam connection plate material 2 on the side where a pass p (weld bead) is formed, and when this pass formation is completed, the rod-shaped member 3 inserted in the above three bolt holes 2c and the shank hole 2d is once removed, and the rod-shaped member 3 is inserted in three bolt holes 2c and the shank hole 2d on the opposite side where the next pass p is formed on the edge portion 2b of the beam connection plate material 2. Of course, the present invention is not limited to this embodiment, and the pass may be formed in a state where the rod-shaped member 3 is inserted in all three bolt holes 2c and two shank holes 2d on both sides. In addition, after one weld layer is formed, the pass may be formed in a state where the rod-shaped member 3 is removed, or even after one or more weld layers are formed, the pass may be formed in a state where the rod-shaped member 3 is inserted.

[0023] The rod-shaped members 3 inserted into the bolt holes 2c and the mandrel holes 2d should preferably have a diameter as close as possible to the diameter of those holes, but it is better to set the diameter considering the ease of insertion operation. The length of the rod-shaped members 3 is made longer than the plate thickness of the beam connection plate material 2, and the longer it is, the better the heat dissipation effect will be, but it is made to a length that does not interfere with welding.

[0024] The above welding method welds (forms a path) between the curved corner 1b and the edge 2b while the rod-shaped member 3 is inserted into the bolt hole 2c and the shim hole 2d, so that it is possible to prevent molten metal from flowing into the bolt hole 2c and the shim hole 2d. Furthermore, since the operation of inserting and removing the rod-shaped member 3 into and from the bolt hole 2c and the shim hole 2d does not require the rotation of the rod-shaped member 3, it is possible to avoid the decrease in work efficiency that occurs in the past when the bolt must be rotated each time into the bolt hole 2c. This effect can be obtained even when the rod-shaped member 3 is made of iron.

[0025] On the other hand, if the rod-shaped member 3 is made of a metal with a thermal conductivity of 200 W / m·k or more (for example, copper (398 W / m·k) etc.), even if the molten metal that has reached the bolt hole 2c or the mandrel hole 2d comes into contact with the rod-shaped member 3, the temperature rise of the rod-shaped member 3 is suppressed, so that the rod-shaped member 3 can be prevented from melting and being joined to the welded portion. In addition, when multi-layer welding is performed by performing multiple welding passes along each edge portion 2b as described above, if the heat around the welded portion is difficult to escape, the welded portion may become gradually cooled and may become annealed. In particular, when welding is performed with a large heat input, such a problem is likely to occur, but if a rod-shaped member 3 with a high thermal conductivity is used, the heat around the welded portion can easily escape (the temperature is difficult to rise), and the annealing can be prevented from occurring. In addition, since metals such as copper are inexpensive, the manufacturing cost of the rod-shaped member 3 can be reduced.

[0026] When a metal having high thermal conductivity as described above is used for the rod-shaped member 3, the second and third weld layers are preferably formed by inserting the rod-shaped member 3 into the bolt hole 2c or the bolt hole 2d in order to promote the escape of heat around the welded area.

[0027] Furthermore, the rod-shaped member 3 may be made only of a metal having high thermal conductivity as described above. However, since aluminum (236 W / m k), a metal with high thermal conductivity, has a low melting point, it is also possible to use a rod-shaped member 3 made of multiple metals, for example, in which an aluminum rod is inserted into a metal tube having a high melting point and a relatively high thermal conductivity.

[0028] If the rod-shaped member 3 is made of a metal with a melting point of 1500°C or higher (for example, tungsten (3387°C), titanium (1725°C), etc.), even if the molten metal that has reached the bolt hole 2c or the mandrel hole 2d comes into contact with the rod-shaped member 3, the rod-shaped member 3 will not melt, and therefore the rod-shaped member 3 can be prevented from being joined to the welded point. However, since metals such as tungsten are relatively expensive, the manufacturing cost of the rod-shaped member 3 will be high. Note that the rod-shaped member 3 is not limited to being made only of a metal with a melting point of 1500°C or higher, and may be a combination with other metals (a configuration including other metals) as described above.

[0029] The rod-shaped member 3 is not limited to being made of metal. The rod-shaped member 3 may be made of a ceramic material. In this case, even if the molten metal that has reached the bolt hole 2c or the bolt hole 2d comes into contact with the rod-shaped member 3, the ceramic material has a high melting point and does not melt, so it is possible to prevent the rod-shaped member 3 from melting and being joined to the beam connection plate material 2. However, since the ceramic material is relatively expensive like tungsten, the manufacturing cost of the rod-shaped member 3 is high.

[0030] Although the embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the illustrated embodiment. Various modifications and variations can be made to the illustrated embodiment within the same scope as the present invention or within an equivalent scope. [Explanation of symbols]

[0031] 1: Square steel pipe 1a: Flat part 1b: Curved corner 2: Beam connection plate 2a: End 2b: Edge area 2c: Bolt hole 2d: Sinohole 3: Rod-shaped member 5: Welding torch 5a: Welding wire p :path

Claims

1. A curved corner portion of the first member; an edge portion of a second member having a bolt hole in the vicinity of the edge portion, the edge portion protruding toward the curved corner portion and a part of a lower end of the bolt hole facing the curved corner portion and not closed; A welding method for joining by welding, comprising the steps of: A welding method comprising the steps of: inserting a rod-shaped member into the bolt hole; and welding the rod-shaped member in that state.

2. 2. The welding method according to claim 1, wherein the second member has a shim hole near the edge portion, and welding is performed with a rod-shaped member for a shim hole inserted into the shim hole.

3. 3. The welding method according to claim 1, wherein the rod-shaped member is made of a metal having a thermal conductivity of 200 W / m·k or more.

4. 3. The welding method according to claim 1, wherein the rod-shaped member is made of a metal having a melting point of 1500° C. or higher.

5. 3. The welding method according to claim 1, wherein said rod-shaped member is made of a ceramic material.

6. 3. The welding method according to claim 1, wherein the first member is a square steel pipe, and the second member is a beam connecting plate.

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