Welding system and welding method

Abstract

To provide a mounting jig which enables a robot arm to be mounted to columns of different sizes.SOLUTION: Provided is a mounting jig 10 for mounting a robot arm 80 to a column 1. The mounting jig 10 comprises: a pair of first support members 20 for supporting the robot arm 80; and a rail member 40 which is supported by the pair of first support members 20, and guides traveling of a carriage 90 on which the robot arm 80 is to be placed. The pair of first support members 20 are removably fixed to an outer surface 1b of the column 1 so as to extend in a horizontal first direction and so as to sandwich the column 1, whereas the rail member 40 is fixed by straddling the pair of first support members 20 so as to extend in a horizontal second direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an attachment jig for attaching two robot arms to columns, which are used for welding the butt joints of steel columns. [Background technology]

[0002] Conventionally, at construction sites, etc., the butt joints of steel columns arranged one above the other are fixed by welding. As such a welding method, a welding method using a robot arm is known (see, for example, Patent Document 1).

[0003] Patent Document 1 describes a welding system in which a guide rail that goes around a steel pipe is fixed to the steel pipe, and a welding robot is moved along the guide rail to weld the butt joints of the steel pipes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-58078 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above Patent Document 1, it is necessary to prepare guide rails according to the size (diameter) of the steel pipe. Since there are usually steel columns of different sizes at a construction site, the welding system of the above Patent Document 1 has a problem in that it is necessary to prepare guide rails of different sizes for one welding robot.

[0006] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a mounting jig that can mount a robot arm to pillars of different sizes. [Means for solving the problem]

[0007] The mounting jig of the present invention is an mounting jig for mounting a robot arm used to weld the butt joints of steel columns arranged above and below the columns, and comprises a pair of first support members that support the robot arm, and a rail member that is supported by the pair of first support members and guides the movement of a cart on which the robot arm is placed, wherein the pair of first support members extend in a horizontal first direction and are removably fixed to the outer surface of the columns so as to sandwich the columns, and the rail member is fixed across the pair of first support members so as to extend in a horizontal second direction that intersects the first direction.

[0008] According to the mounting jig of the present invention, a pair of first support members extend in a first direction and are fixed to the pillar so as to sandwich the pillar, and the rail member is fixed to the pair of first support members so as to extend in a second direction. This allows the mounting jig to be fixed to the pillar regardless of the size (diameter) of the pillar, so there is no need to prepare mounting jigs for each size (diameter) of the pillar as in Patent Document 1.

[0009] The above mounting jig preferably further includes a second support member fixed across the pair of first support members so as to extend in the second direction, the second support member supporting the rail member. With this configuration, the strength required to support the robot arm can be ensured by the second support member, thereby reducing the strength required for the rail member. This prevents the rail member from becoming larger and heavier.

[0010] In the above-described mounting jig, the second support member preferably has a truss structure including a plurality of chord members extending in the second direction and a plurality of reinforcing members arranged perpendicular to the chord members and connecting adjacent chord members so as to complete a full loop around the chord members at the same position in the second direction. By providing reinforcing members perpendicular to the chord members so as to complete a full loop around the chord members, the torsional strength of the second support member can be improved. Therefore, even if the center of gravity of the robot arm changes due to the extension or contraction of the arm portion of the robot arm, causing a torsional load to be applied to the second support member, twisting of the second support member can be suppressed. This suppresses deviation of the tip position of the welding torch of the robot arm from the desired position due to the effects of gravity or vibration.

[0011] The above-mentioned mounting jig including a second support member preferably further includes a fixing member for fixing the second support member to the first support member, the fixing member including a plate-shaped first mounting fixture attached to the first support member and a second mounting fixture for fixing the second support member to the first mounting fixture, the first mounting fixture having protrusions protruding from both sides in the width direction of the first support member, the protrusions of the first mounting fixture being provided with mounting position adjustment portions for adjusting the mounting position of the second mounting fixture along the width direction of the first support member. With this configuration, the second mounting fixture can be attached to the first mounting fixture in various positions, thereby preventing the second mounting fixture from becoming unable to be attached to the first mounting fixture regardless of the position of a diagonal member, reinforcing member, etc. relative to the first mounting fixture.

[0012] In the above-described mounting jig including a second support member, preferably, the second support member is integrally provided with a mounting piece that extends along the second direction and is attached to the first support member, and the mounting piece is provided with a mounting position adjustment portion that adjusts the mounting position relative to the first support member along the second direction. With this configuration, the mounting position of the mounting piece relative to the first support member can be adjusted. In other words, even if the spacing between a pair of first support members is different (if the pillars are different sizes), the second support member can be easily mounted to the first support member.

[0013] In the above-described mounting jig, preferably, the second support member is formed so as to be separable between the pair of first support members. This configuration allows the second support member to be separated, making it easier to transport. Furthermore, even in this case, when a carriage carrying a robot arm moves to the end of the second support member, a large force is applied to the second support member. However, even in this case, since the second support member is fixed to the first support member between the connecting portion (separation position) of the robot arm and the second support member, the stress acting on the connecting portion (separation position) can be relatively small. Therefore, damage to the second support member at the connecting portion (separation position) can be suppressed.

[0014] In the above mounting jig, preferably, cable avoidance members are provided at both ends of the first support member, protruding outward in the width direction of the first support member and preventing a cable connected to the robot arm from contacting the first support member. With this configuration, when a carriage carrying a robot arm moves along a rail, the cable avoidance members can prevent a cable extending from the robot arm to a welding machine or the like from getting caught on the first support member.

[0015] In the above mounting jig, preferably, a pair of rail members are provided, and the pair of rail members extend in the second direction and are fixed across the pair of first support members so as to sandwich the pillar. By providing the pair of rail members so as to sandwich the pillar in this way, robot arms can be positioned on both sides of the pillar. This allows welding to be performed from both sides of the pillar, thereby shortening the welding time. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a mounting jig that can mount a robot arm to pillars of different sizes. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view showing a state in which a robot arm is attached to a pillar using an attachment jig according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a perspective view showing the structure of a first support member of the mounting jig according to the first embodiment of the present invention. [Figure 3] 1 is a perspective view showing a mounting structure of a first support member of a mounting jig according to a first embodiment of the present invention to a pillar. [Figure 4] FIG. 2 is a perspective view illustrating the structure of a first mounting fixture and a cable shelter member attached to a first support member of the mounting jig according to the first embodiment of the present invention. [Figure 5] FIG. 2 is a perspective view showing the structure of a support member structure that constitutes a second support member of the mounting jig according to the first embodiment of the present invention. [Figure 6] FIG. 3 is a perspective view illustrating the structure of a second mounting fixture and a rail fixing member of the mounting jig according to the first embodiment of the present invention. [Figure 7] 1 is a cross-sectional view showing a state in which a rail member of the mounting jig according to the first embodiment of the present invention is fixed to a rail fixing member. [Figure 8] 1 is a plan view showing the structure around a cable shelter member of a mounting jig according to a first embodiment of the present invention. FIG. [Figure 9]2 is a perspective view showing a state in which the mounting jig according to the first embodiment of the present invention is mounted on a pillar larger in size than the pillar shown in FIG. 1. FIG. [Figure 10] FIG. 10 is a perspective view for explaining the structure around the first mounting fixture in FIG. 9. [Figure 11] 10 is a perspective view for explaining the structure around the second mounting fixture and the rail fixing member in FIG. 9. FIG. [Figure 12] FIG. 10 is a perspective view showing the structure of a mounting jig according to a second embodiment of the present invention. [Figure 13] FIG. 10 is a perspective view showing the structure of a mounting jig according to a modified example of the second embodiment of the present invention. [Figure 14] FIG. 10 is a perspective view showing the structure of a mounting jig according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, a mounting jig according to an embodiment of the present invention will be described with reference to the drawings.

[0019] (First embodiment) FIG. 1 is a perspective view showing a state in which a robot arm 80 is attached to a pillar 1 using an attachment jig 10 according to a first embodiment of the present invention.

[0020] As shown in Fig. 1, at a construction site or the like, a robot arm 80 is used to weld the butt joints 1a of columns 1 made of polygonal steel pipes arranged one above the other. The robot arm 80 is detachably attached to the columns 1 using an attachment jig 10.

[0021] The outer surface 1b of the pillar 1 is formed by four flat portions and four curved portions. Multiple (four in this case) protrusions (also called erection pieces) 2 are welded to predetermined positions on the flat portions of the outer surface 1b of each pillar 1. These protrusions 2 are provided to temporarily fix adjacent pillars 1 together vertically. Temporary fixing jigs 3 are attached to the two protrusions 2 arranged vertically.

[0022] The temporary fixing jig 3 extends in the vertical direction, with its upper end fastened to the protrusion 2 using bolts 4 or the like, and its lower end fastened to the protrusion 2 using bolts 4 or the like. Although detailed explanation of the temporary fixing jig 3 will be omitted here, it may be configured so that the distance between two protrusions 2 arranged above and below can be adjusted. This makes it possible to adjust the gap between the columns 1 arranged above and below, as well as to adjust the inclination of the column 1 arranged above. The temporary fixing jig 3 is removed from the protrusions 2 when welding of the butt portions 1a of the columns 1 is completed, or, even if welding of the butt portions 1a is in progress, when the joint strength between the columns 1 becomes strong enough to support the building under construction.

[0023] Additionally, support pieces 1c that support the mounting jig 10 are welded to predetermined positions on the pillar 1 arranged below. Two support pieces 1c are provided on opposing flat surfaces of the outer surface 1b of the pillar 1, and first support members 20 (described later) of the mounting jig 10 are fixed to the support pieces 1c.

[0024] The mounting jig 10 includes a pair of first support members 20 and a pair of second support members 30 that support two robot arms 80, and a pair of rail members 40. The pair of first support members 20 extend in a horizontal first direction (arrow A direction) and are fixed to the outer surface 1b of the pillar 1 so as to sandwich the pillar 1 between them. The pair of second support members 30 extend in a second direction (arrow B direction) that intersects (is perpendicular to) the first direction and are fixed across the pair of first support members 20 so as to sandwich the pillar 1 between them. Each rail member 40 is fixed on the second support member 30 and guides the robot arm 80 in the second direction (arrow B direction). The first direction (arrow A direction) and the second direction (arrow B direction) are parallel to or perpendicular to the flat portion of the outer surface 1b of the pillar 1.

[0025] Next, the detailed structures of the first support member 20 and the second support member 30 will be described.

[0026] Although the material and cross-sectional shape of the first support member 20 are not particularly limited, an aluminum alloy is used here to reduce weight. As shown in FIG. 2 , the first support member 20 has an H-shaped cross section and includes a pair of flanges 21 and 22 and a web 23 connecting the pair of flanges 21 and 22, and is formed so as to extend in a predetermined direction (the direction of arrow A when attached to the column 1). A plurality of through holes (also referred to as through holes) 21a are provided on both sides of the flange 21 in the longitudinal direction (the direction of arrow A) for fastening the first mounting fixture 51 described below. Because the plurality of through holes 21a are provided along the longitudinal direction of the flange 21, the fastening position of the first mounting fixture 51 relative to the flange 21 can be adjusted in the longitudinal direction of the flange 21 (the direction of arrow A).

[0027] A plurality of through holes 21b for fastening an L-shaped plate 26 (described later) are provided at a predetermined interval in the longitudinal direction of the flange 22 near the center of the flange 22. Because the through holes 21b are formed long in the longitudinal direction of the flange 22, it is possible to finely adjust the fastening position of the L-shaped plate 26 in the longitudinal direction of the flange 22 (direction of arrow A).

[0028] As shown in Fig. 3, the first support member 20 is detachably fixed to a pair of support pieces 1c provided on the pillar 1. Specifically, an L-shaped plate (also called an angle) 26 is fastened to each support piece 1c using a bolt 25a and a nut 25b. The L-shaped plate 26 is arranged so that the support surface that supports the first support member 20 is horizontal. A bolt 27a is inserted into the through-hole 21b of the first support member 20 and a through-hole (not shown) of the L-shaped plate 26, and the first support member 20 is fixed to the support piece 1c using the bolt 27a and the nut 27b.

[0029] As shown in FIG. 4 , cable shielding members 28 are fixed to both ends of the first support member 20. The cable shielding members 28 protrude outward in the width direction (direction of arrow B) of the first support member 20 and prevent a cable 89 (described later) connected to the robot arm 80 from coming into contact with the first support member 20. The cable shielding members 28 are formed so that the amount of protrusion in the width direction relative to the first support member 20 decreases toward both ends of the first support member 20. Specifically, the cable shielding members 28 include fixing surface portions 28a that are fixed to both ends of the first support member 20 using bolts 29a and nuts 29b, and extending portions 28b that protrude from the fixing surface portions 28a in the width direction (direction of arrow B) of the first support member 20 and extend inward in the longitudinal direction of the first support member 20. The extending portions 28b are formed by bending a pipe, a rod, or the like. In addition, the extension portion 28b is formed to extend to a position closer to the second support member 30 than the connection position of the cable 89 (here, the rear end 82a of the swivel base 82 of the robot arm 80, which will be described later; see dashed line L in Figure 8).

[0030] The material of the second support member 30 is not particularly limited, but an aluminum alloy is used here from the viewpoint of weight reduction. The second support member 30 is formed to extend in a predetermined direction (the direction of arrow B when attached to the first support member 20). The second support member 30 is also configured to be separable at a predetermined position (here, the center position in the longitudinal direction (the direction of arrow B)). Hereinafter, the second support member 30 in a separated state will be referred to as a support member structure 30a.

[0031] As shown in Fig. 5, the support member structure 30a is formed in the shape of an elongated frame having a plurality of (four in this case) chord members 31 made of pipes or rods extending in the second direction (the direction of arrow B) and end plates 32 welded to both ends of the chord members 31. The end plates 32 maintain a constant distance between the chord members 31. The end plates 32 also have a plurality of through holes 32a into which bolts 30b (see Fig. 6) are inserted when connecting the support member structures 30a together to form the second support member 30.

[0032] In addition, the support member structure 30a is formed into a truss structure including a plurality of diagonal members 33 made of pipes or rods arranged at an angle to the chord member 31, and a plurality of reinforcing members 34 made of pipes or rods arranged perpendicular to the chord member 31.

[0033] The diagonal members 33 are welded to connect adjacent chord members 31. Furthermore, the multiple diagonal members 33 connecting two adjacent chord members 31 are arranged so that the inclination direction relative to the chord member 31 is alternately opposite in the longitudinal direction (direction of arrow B) of the chord member 31. Furthermore, the multiple diagonal members 33 are arranged at predetermined intervals from each other in the longitudinal direction (direction of arrow B) of the chord member 31.

[0034] The reinforcing members 34 are welded to connect adjacent chord members 31 together. Specifically, the reinforcing members 34 are arranged between adjacent diagonal members 33 in the second direction (the direction of arrow B) and between the diagonal members 33 and the end plates 32. In other words, the reinforcing members 34 are arranged so as to sandwich the diagonal members 33 in the second direction (the direction of arrow B). Furthermore, the multiple reinforcing members 34 (four in this case) are arranged at the same position in the second direction (the direction of arrow B) and are arranged so as to go around the multiple chord members 31 (the support member structure 30a).

[0035] As shown in Figures 1 and 6, this support member structure 30a is fixed to the first support member 20 using fixing members 50. As shown in Figures 4 and 6, the fixing members 50 include plate-shaped first mounting fixtures 51 that are attached to the first support member 20, and second mounting fixtures 52 that fix the chord members 31 to the first mounting fixtures 51. Each support member structure 30a is fixed to the first support member 20 using two first mounting fixtures 51, four second mounting fixtures 52, bolts 55a, 56, and nuts 55b, which will be described later.

[0036] The first mounting fixture 51 has a central portion 51a that is placed on the first support member 20, and a pair of protruding portions 51b that are positioned on either side of the central portion 51a in the second direction (the direction of arrow B) and protrude from both sides of the width direction of the first support member 20 (the direction of arrow B). The central portion 51a is formed with a plurality of (four here) through holes 51c (see FIG. 4) for fastening the first mounting fixture 51 to the first support member 20 using bolts 55a and nuts 55b, and a pair of screw holes 51d for fastening the second mounting fixture 52 to the first mounting fixture 51. The through holes 51c are formed long in the first direction (the direction of arrow A), so that the fastening position of the first mounting fixture 51 relative to the first support member 20 can be fine-tuned in the first direction (the direction of arrow A).

[0037] Each protrusion 51b has multiple pairs (four pairs here) of screw holes (mounting position adjustment portions) 51e formed along the second direction (the direction of arrow B) for fastening the second mounting fixture 52. This makes it possible to adjust the fastening position of the second mounting fixture 52 relative to the first mounting fixture 51 in the second direction (the direction of arrow B). In other words, since the second mounting fixture 52 can be attached to the first mounting fixture 51 in various positions, it is possible to prevent the second mounting fixture 52 from becoming unable to be attached to the first mounting fixture 51 regardless of the positions of the diagonal member 33, the reinforcing member 34, etc., relative to the first mounting fixture 51.

[0038] The second mounting fixture 52 has a pair of brackets 52a that sandwich the chord material 31 of the support member structure 30a from above and below. The brackets 52a are formed with a U-shaped cross section, with a concave surface that holds the chord material 31. The concave surface of the brackets 52a is formed to have approximately the same curvature as the outer circumferential surface of the chord material 31. Each bracket 52a is formed to extend in a first direction (the direction of arrow A) while holding the chord material 31, and through holes 52b are formed at both ends of the bracket 52a in the longitudinal direction (the direction of arrow A). The pair of brackets 52a are fastened to predetermined positions of the first mounting fixture 51 using bolts 56, with the chord material 31 of the support member structure 30a sandwiched between them. In this way, each support member structure 30a is fixed to one first support member 20. The end plates 32 of adjacent support member structures 30a in the second direction (the direction of arrow B) are fastened to each other using multiple (here, 12) bolts 30b. This forms the second support member 30. The fastening position between adjacent support member structures 30a (i.e., the dividing position of the second support member 30) is located between the pair of first support members 20, as shown in FIG.

[0039] The material of the rail member 40 is not particularly limited, but for example, steel can be used. As shown in Figures 6 and 7, the rail member 40 includes a main body 41 and a pair of rails (also referred to as linear guide rails) 42 fixed to the upper part of the main body 41 using bolts or the like, and is formed in an elongated shape extending in a second direction (arrow B direction). Note that Figure 7 is a cross-sectional view taken along a first direction (arrow A direction) passing through a through-hole 62d of a support plate 62 of a rail fixing member 60, which will be described later.

[0040] A pair of grooves 41a extending in the second direction (arrow B direction) and spaced a predetermined distance from each other are formed on the bottom surface of the main body 41. Nuts 41b are embedded in each groove 41a at predetermined positions in the longitudinal direction (arrow B direction).

[0041] The pair of rails 42 are formed with engagement grooves 42a extending in the second direction (the direction of arrow B) into which the carriage 90 of the robot arm 80 slidably engages.

[0042] The rail member 40 is fixed to the second support member 30 using a rail fixing member 60. The rail fixing member 60 includes a third mounting fixture 61 attached to the chord member 31 of the second support member 30, and a support plate 62 fixed to the third mounting fixture 61.

[0043] The third mounting fixture 61 is formed in the same manner as the second mounting fixture 52. That is, the third mounting fixture 61 has a pair of brackets 61a that sandwich the chord material 31 of the support member structure 30a from above and below. The brackets 61a are formed with a U-shaped cross section, with a concave surface that holds the chord material 31. The concave surface of the brackets 61a is formed to have approximately the same curvature as the outer peripheral surface of the chord material 31. Furthermore, each bracket 61a is formed to extend in a first direction (the direction of arrow A) while holding the chord material 31, and through holes 61b are formed at both ends of the brackets 61a in the longitudinal direction (the direction of arrow A).

[0044] The support plate 62 has a T-shaped cross section, including a thick portion 62a and a pair of thin portions 62b arranged on either side of the thick portion 62a in the width direction (the direction of arrow B), and is formed to extend in a first direction (the direction of arrow A). A plurality of (here, two) through holes 62c are formed at predetermined positions in each of the thin portions 62b for fastening the support plate 62 to the bracket 61a using bolts 63a and nuts 63b. Because the through holes 62c are formed long in the first direction (the direction of arrow A), the fastening position of the support plate 62 relative to the bracket 61a (i.e., relative to the chord member 31) can be finely adjusted in the first direction (the direction of arrow A).

[0045] A pair of brackets 61a sandwich the chord material 31 of the support member structure 30a from above and below, and with a support plate 62 placed on the upper bracket 61a, the support plate 62 and the pair of brackets 61a are fixed to a predetermined position on the chord material 31 using bolts 63a and nuts 63b.

[0046] The thick portion 62a of the support plate 62 is formed to a thickness that protrudes upward beyond the head of the bolt 63a when the bolt 63a is inserted into the through hole 62c of the thin portion 62b. This prevents the rail member 40 from coming into contact with the bolt 63a. A pair of through holes 62d are also formed in predetermined positions of the thick portion 62a. Then, with the rail member 40 placed on the support plate 62, the rail member 40 is fixed to the support plate 62 using the bolt 64 and the nut 41b.

[0047] As described above, the second support member 30 is formed so as to be separable between the pair of first support members 20. This allows the second support member 30 to be separated, making it easier to transport. Furthermore, when the carriage 90 carrying the robot arm 80 moves to the end of the second support member 30, a large force is applied to the second support member 30. However, even in this case, since the second support member 30 is fixed to the first support member 20 between the connecting portion (separation position) of the robot arm 80 and the second support member 30, the stress acting on the connecting portion (separation position) can be made relatively small. Therefore, it is possible to prevent the second support member 30 from being damaged at the connecting portion (separation position).

[0048] Next, the structure of the robot arm 80 will be briefly described.

[0049] 1 and 8 , the robot arm 80 is placed on a carriage 90 that is placed on the rail member 40 and travels along the rail member 40. The robot arm 80 includes a swivel base 82 that is placed on the carriage 90 and is rotatable about an axis extending in the vertical direction, a main body 83 that is placed on the swivel base 82 and extends upward, a first shaft 84 that is placed on the main body 83 and is rotatable about an axis extending in the horizontal direction, a second shaft 85 that is connected to the first shaft 84 and is rotatable about the axis, a first arm 86 that is connected to the tip of the second shaft 85 and is rotatable about an axis perpendicular to the second shaft 85, a second arm 87 that is connected to the tip of the first arm 86 and is rotatable relative to the first arm 86, a welding torch 88 provided at the tip of the second arm 87, and a cable 89 that extends to the outside from a rear end 82 a of the swivel base 82.

[0050] The robot arm 80 is moved to a predetermined position by the carriage 90, and by driving the swivel base 82, the first shaft 84, the second shaft 85, the first arm 86, and the second arm 87, the tip of the welding torch 88 is positioned at a desired position on the butt joint 1a between the pillars 1 to perform welding. The robot arm 80 and the carriage 90 may be driven manually or automatically.

[0051] The cable 89 is not particularly limited, but examples thereof include a power cable and a control cable for manually controlling the robot arm 80.

[0052] Here, since both ends of the first support member 20 are formed to protrude further outward in the first direction (the direction of arrow A) than the second support member 30, it is conceivable that the cable 89 may get caught on the first support member 20 when the carriage 90 carrying the robot arm 80 moves along the rail member 40. Therefore, in the present embodiment, as described above, the cable avoiding members 28 are provided on both ends of the first support member 20. As a result, even if the carriage 90 carrying the robot arm 80 moves along the rail member 40, the cable 89 comes into contact with the extending portion 28b of the cable avoiding member 28 and moves along the extending portion 28b. This makes it possible to prevent the cable 89 from getting caught on the first support member 20.

[0053] When the robot arm 80 welds a position far from the second support member 30 (for example, the center position between a pair of second support members 30), the first arm portion 86 and other components are positioned to extend in the first direction (the direction of arrow A). At this time, the center of gravity of the robot arm 80 moves to a position farther away from the second support member 30 in the first direction (the direction of arrow A). As a result, a torsional load acts on the second support member 30. In this case, it is conceivable that the second support member 30 will twist, causing the tip position of the welding torch 88 to deviate from the desired position. Therefore, in this embodiment, in addition to the diagonal member 33 inclined relative to the chord member 31, the second support member 30 is provided with a plurality of reinforcing members 34 that are arranged perpendicular to the chord members 31 and connect adjacent chord members 31 so as to make a full circle around the plurality of chord members 31 at the same position in the second direction (the direction of arrow B). This improves the torsional strength of the second support member 30 in addition to the bending strength, and therefore, even if the position of the center of gravity of the robot arm 80 changes and a torsional load is applied to the second support member 30, it is possible to prevent the second support member 30 from twisting. Therefore, it is possible to prevent the tip position of the welding torch 88 of the robot arm 80 from shifting from the desired position due to the influence of gravity or vibration.

[0054] Next, as shown in FIG. 9, a case where the mounting jig 10 is mounted on a pillar 1 having a larger size (diameter) than the pillar 1 shown in FIG. 1 will be described.

[0055] 9 and 10 , when the size (diameter) of the pillar 1 is large, the distance between the second support members 30 becomes large, and therefore the first mounting fixtures 51 for attaching the second support members 30 to the first support members 20 are attached to positions close to both ends of the first support members 20. In this embodiment, a plurality of through holes 21a are provided along the longitudinal direction on both longitudinal sides of the first support member 20, so that even when the size (diameter) of the pillar 1 is large, it is possible to fix the second support members 30 to the first support members 20 while ensuring the distance between the pillar 1 and the second support members 30.

[0056] 9 and 11 , when the size (diameter) of the column 1 is large, the distance between the first support members 20 increases, causing the attachment position of the second mounting fixture 52 relative to the second support member 30 to shift in the second direction (arrow B direction). In this case, since the second support member 30 is provided with a plurality of diagonal members 33 and reinforcing members 34, it is conceivable that the attachment position of the second mounting fixture 52 relative to the second support member 30 will be restricted, making it impossible to attach the second mounting fixture 52 to the first mounting fixture 51. In this embodiment, as described above, the first mounting fixture 51 is provided with a plurality of screw holes 51d and 51e along the second direction (arrow B direction). Therefore, even if the attachment position of the second mounting fixture 52 relative to the second support member 30 is restricted, it is possible to prevent the second mounting fixture 52 from becoming unable to attach to the first mounting fixture 51.

[0057] In this embodiment, as described above, the pair of first support members 20 extend in a first direction (the direction of arrow A) and are fixed to the pillar 1 so as to sandwich the pillar 1 therebetween, and the pair of rail members 40 extend in a second direction (the direction of arrow B) and are fixed to the pair of first support members 20 so as to sandwich the pillar 1 therebetween. This allows the mounting jig 10 to be fixed to the pillar 1 regardless of the size (diameter) of the pillar 1, so there is no need to prepare mounting jigs for each size (diameter) of the pillar 1 as in Patent Document 1 mentioned above.

[0058] As described above, the robot further includes a pair of second support members 30 that extend in the second direction (the direction of arrow B) and are fixed across the pair of first support members 20 so as to sandwich the pillar 1. This allows the strength required to support the robot arm 80 to be ensured by the second support members 30, thereby reducing the strength required for the rail member 40. This prevents the rail member 40 from becoming larger and heavier.

[0059] (Second embodiment) Next, the structure of a mounting jig 10 according to a second embodiment of the present invention will be described.

[0060] 12, in this embodiment, an attachment piece 35 extending along the longitudinal direction (arrow B direction) of the second support member 30 is integrally welded to a chord member 31 of the support member structure 30a (second support member 30). The attachment piece 35 has a plurality of through holes (attachment position adjustment portions) 35a that open in the width direction (arrow A direction) of the second support member 30 and are formed along the second direction (arrow B direction). The attachment piece 35 is fixed to a predetermined position on the first support member 20 using an L-shaped plate (also called an angle) 36.

[0061] In this embodiment, the mounting piece 35 has a plurality of through holes 35a formed along the second direction (the direction of arrow B), so that the mounting position of the mounting piece 35 relative to the L-shaped plate 36 (i.e., the mounting position relative to the first support member 20) can be adjusted in the second direction (the direction of arrow B). In other words, even if the intervals between the pair of first support members 20 are different (if the sizes of the pillars 1 are different), the second support member 30 can be easily attached to the first support member 20.

[0062] Furthermore, by providing the mounting pieces 35 integrally with the support member structure 30a (second support member 30), the number of parts of the mounting jig 10 can be reduced, and the mounting workability can be improved.

[0063] Here, an example has been shown in which the mounting piece 35 is attached to the first support member 20 using an L-shaped plate 36, but it may also be configured as in the mounting jig 10 according to the modified example of the second embodiment shown in Fig. 13, for example. Specifically, the mounting piece 37 is integrally welded to the chord member 31 of the support member structure 30a (second support member 30) with a plurality of through holes (mounting position adjustment portions) 37a opening in the vertical direction. This makes it possible to further reduce the number of parts of the mounting jig 10 and further improve the ease of installation.

[0064] (Third embodiment) Next, the structure of a mounting jig 10 according to a third embodiment of the present invention will be described.

[0065] 14, in this embodiment, the cable avoidance member 128 is disposed so as to extend in parallel with and at a predetermined distance from the second support member 30. Specifically, the cable avoidance member 128 is formed so as to protrude outward in the width direction of the first support member 20, and is formed so as to have approximately the same length as the rail member 40. The cable avoidance member 128 is fixed using a bolt 29a and a nut 29b (see FIG. 4) so ​​as to straddle the ends of the pair of first support members 20.

[0066] Here, cable shielding member 128 is formed by a long member (also called an angle) formed with an L-shaped cross section. Note that cable shielding member 128 may be formed by, for example, a pipe material or a rod material instead of a member formed with an L-shaped cross section.

[0067] Furthermore, a plurality of through holes 128a that open in the vertical direction are provided along the second direction (the direction of arrow B) in the cable shelter member 128. Because the through holes 128a are formed long in the second direction (the direction of arrow B), it is possible to adjust the attachment position of the cable shelter member 128 relative to the first support member 20 in the second direction (the direction of arrow B).

[0068] In this embodiment, by providing a cable avoiding member 128, even if the cart 90 carrying the robot arm 80 moves along the rail member 40, the cable 89 moves along the cable avoiding member 128, so as in the first embodiment above, the cable 89 can be prevented from getting caught on the first support member 20.

[0069] It should be noted that the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims.

[0070] For example, in the above embodiment, an example is shown in which polygonal steel pipes are used as steel columns, but the present invention is not limited to this, and circular steel pipes may be used, or other steel columns such as H-shaped steel columns may be used.

[0071] In the above embodiment, the second support member is disposed on the first support member, and the rail member is disposed on the second support member, but the present invention is not limited to this. The rail member may be disposed on the first support member without providing the second support member.

[0072] In the above embodiment, a pair of rail members is provided on either side of the column, and a robot arm is placed on each of the pair of rail members. However, the present invention is not limited to this. For example, when welding is performed using a single robot arm, only one of the pair of rail members shown in FIG. 1 may be provided. In this case, after welding half of the butt joint, the rail member may be reattached to the opposite side of the column, and the remaining half of the butt joint may be welded using the same robot arm. In this case, as in the above embodiment, the rail members (or the rail members via the second support member) may be configured to be fixed to both longitudinal sides of the first support member. Furthermore, for example, when welding an H-shaped steel column having two opposing flanges and a web connecting the flanges, by placing a rail member along one of the flanges, the entire butt joint 1a can be welded using a single robot arm without having to reattach the rail member to the opposite side of the column.

[0073] Furthermore, in the above embodiment, an example has been shown in which the support member structure (second support member) is formed into a truss structure including chord members 31, diagonal members 33 arranged at an angle to the chord members 31, and reinforcing members 34 arranged perpendicular to the chord members 31, but the present invention is not limited to this. For example, the support member structure (second support member) may be formed into a Vierendeel truss structure including chord members 31 and reinforcing members 34 arranged perpendicular to the chord members 31, without including diagonal members 33.

[0074] In addition, in the above embodiment, an example was shown in which the outer shape of the support member structure (second support member) was a quadrangular prism, but the present invention is not limited to this. For example, the outer shape of the support member structure (second support member) may be a triangular prism, or may be a shape obtained by cutting off a part of a cylinder (for example, a semicircular cross section). In this case, it is preferable that the outer shape of the support member structure (second support member) is formed so as to widen downward.

[0075] In the above embodiment, the first support member has an H-shaped cross section and the second support member has a truss structure, but the present invention is not limited to this. For example, the first support member may have a truss structure and the second support member may have an H-shaped cross section. Furthermore, both the first support member and the second support member may have an H-shaped cross section or a truss structure. [Explanation of symbols]

[0076] 1: pillar, 1a: butt joint, 1b: outer surface, 10: mounting jig, 20: first support member, 28: cable avoidance member, 30: second support member, 31: chord member, 34: reinforcement member, 35, 37: mounting pieces, 35a, 37a: through holes (mounting position adjustment portion), 40: rail member, 50: fixing member, 51: first mounting fixture, 51b: protrusion, 51e: screw hole (mounting position adjustment portion), 52: second mounting fixture, 80: robot arm, 89: cable, 90: dolly

Claims

1. A welding system used to weld the butt joints between steel columns arranged vertically, two robot arms that perform the welding; two carriages on which the two robot arms are respectively placed; two linear rail members that respectively guide the travel of the two carriages; the two linear rail members are arranged on the pillar so as to extend in a horizontal direction and face each other across the pillar, Each of the two linear rail members is attached to the column via a pair of support members, Each of the two robot arms can be driven to weld half of the circumference of the butt portion of the pillars, The pair of support members extend in a horizontal first direction and are detachably fixed to an outer surface of the pillar so as to sandwich the pillar, The welding system is characterized in that the rail member is fixed across the pair of support members so as to extend in a horizontal second direction perpendicular to the first direction.

2. A welding system as described in Claim 1, characterized in that a plurality of mounting through holes for adjusting the mounting position of the rail member in the first direction are provided on both sides of the support member at intervals along the longitudinal direction of the support member.

3. A welding method for welding the butt joints of steel columns arranged vertically, Two linear rail members are arranged on the pillar so as to extend horizontally opposite each other across the pillar, a carriage carrying a robot arm on each of the two linear rail members is caused to travel along the linear rail members; The welding of the butt joints is performed by the two robot arms, The two linear rail members are arranged by attaching each of the two linear rail members to the column via a pair of support members, The pair of support members are detachably fixed to an outer surface of the pillar so as to extend in a horizontal first direction and sandwich the pillar therebetween; The rail member is fixed across the pair of support members so as to extend in a horizontal second direction perpendicular to the first direction, A welding method characterized by driving each of the two robot arms so as to weld half of the circumference of the butt joint between the pillars.

4. A welding method as described in claim 3, characterized in that the mounting position of the rail member in the first direction is adjusted by using a plurality of mounting through holes spaced apart along the longitudinal direction of the support member on both sides of the support member.

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