Welding method and welding apparatus

Abstract

To provide a welding method and a welding apparatus which can automatically weld diagonal members with each other.SOLUTION: A welding method includes a lamination step of laminating in the depth direction metal layers by forming the metal layers extending in the oblique direction and vertical direction with a melted wire 51 while weaving a welding torch 6 that melts the wire 51 (weld material) by movement means to a groove 4 which extends in the oblique direction and whose depth direction becomes the horizontal direction. The weaving repeatedly performs the first operation of advancing in the direction heading to the upper side along an end surface of the first diagonal member 2 (first member) for each metal layer, the second operation of advancing in the horizontal direction to the end surface of the second diagonal member 3 (second member) from the end surface of the first diagonal member 2 following the first operation, the third operation of advancing in the direction heading to the upper side along the end surface of the second diagonal member 3 following the second operation, and the fourth operation of advancing to the lower side gradually from the end surface of the second diagonal member 3 to the end surface of the first diagonal member 2 following the third operation in this order, and switches between the attitude of the welding torch 6 in the first operation and the attitude of the welding torch 6 in the third operation.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] This invention relates to a welding method and a welding apparatus. [Background technology]

[0002] Conventionally, welding robots that perform automatic welding are devices that automatically perform downward welding or sideways welding, and are intended for welding columns and beams (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-130557 [Patent Document 2] Japanese Patent Publication No. 2021-79444 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] When welding diagonal members together using a groove extending diagonally, a problem arises when welding horizontally: the shape of the weld bead is unstable due to the effects of gravity. This makes it difficult to control the shape of the weld bead and the direction in which the beads are layered when performing automated welding. For this reason, it is difficult to use automated welding for welding diagonal members together.

[0005] The present invention aims to provide a welding method and welding apparatus that can automatically weld diagonal members together. [Means for solving the problem]

[0006] To achieve the above objective, the welding method according to the present invention includes a lamination step of forming metal layers extending in the diagonal and vertical directions with the molten welding material in a groove formed between the end faces of a first member and a second member to be welded together, which extends in a diagonal direction intersecting a horizontal plane and has a depth direction that is horizontal, while weaving a welding torch that melts the welding material with a moving means, thereby stacking the metal layers in the depth direction, and repeating in the order of a first movement that moves upward along the end face of the first member, a second movement that moves horizontally from the end face of the first member to the end face of the second member following the first movement, a third movement that moves upward along the end face of the second member following the second movement, and a fourth movement that moves gradually downward from the end face of the second member to the end face of the first member following the third movement, and switching the position of the welding torch in the first movement and the position of the welding torch in the third movement.

[0007] To achieve the above objective, the welding apparatus according to the present invention comprises a welding torch for melting a welding material, a moving means for moving the welding torch, a moving control unit for controlling the moving means, and a posture control unit for controlling the posture of the welding torch. The moving control unit controls the welding torch to weave into a groove formed between the end faces of a first member and a second member to be welded together, extending in an oblique direction intersecting a horizontal plane and having a depth direction that is horizontal, thereby forming metal layers extending in the oblique and vertical directions with the molten welding material, and stacking the metal layers in the depth direction. The weaving is performed repeatedly in the following order for each metal layer: a first movement that moves upward along the end face of the first member; a second movement that follows the first movement and moves horizontally from the end face of the first member to the end face of the second member; a third movement that follows the second movement and moves upward along the end face of the second member; and a fourth movement that follows the third movement and moves gradually downward from the end face of the second member to the end face of the first member. The attitude control unit controls the attitude of the welding torch in the first movement and the attitude of the welding torch in the third movement.

[0008] In this invention, by weaving the welding torch while switching its position, a metal layer can be formed stably, creating a vertically extending metal layer with height along the direction in which the groove extends. This stabilizes the shape of the metal layer (bead), allowing for control over the shape of the metal layer and the direction in which it is layered. As a result, it is possible to automatically weld diagonal members with grooves extending diagonally.

[0009] Furthermore, the welding method according to the present invention includes a metal layer vertical width calculation step for calculating the vertical width dimension of each metal layer to be formed, and a weaving path determination step for determining the weaving path according to the vertical width dimension of the metal layer calculated in the metal layer vertical width calculation step, wherein the lamination step may be performed along the weaving path determined in the weaving path determination step.

[0010] Because the weaving path can be determined according to the vertical width dimension of the formed metal layer, the shape of the metal layer can be made more stable, and diagonal members with grooves extending diagonally can be automatically welded together. [Effects of the Invention]

[0011] According to the present invention, diagonal members can be automatically welded together. [Brief explanation of the drawing]

[0012] [Figure 1] This is a view of the welded first and second diagonal members in the thickness direction. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This figure shows the layered state of the metal layers in the welding method according to this embodiment. [Figure 4] This figure shows the layering state of metal layers in a conventional welding method. [Figure 5] This diagram shows the position of the welding torch when performing the first operation. [Figure 6] This diagram shows the position of the welding torch when performing the third operation. [Figure 7] It is a diagram showing weaving. [Figure 8] It is a diagram for explaining the process of calculating the vertical width of the metal layer. [Figure 9] It is a diagram for examining the presence or absence of interference between the welding torch and the second end face with respect to the welding angle θ. [Figure 10] It is a diagram showing a welding torch with a welding angle of 0°.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, a welding method and a welding apparatus according to an embodiment of the present invention will be described based on FIGS. 1 - 10. The welding method according to the present embodiment is a method for automatically welding two diagonal members 2 and 3 such as braces as shown in FIGS. 1 and 2. The two diagonal members 2 and 3 have their respective end faces 21 and 31 welded to each other. A groove-shaped groove 4 is provided between the end faces 21 and 31 of the two diagonal members 2 and 3 to be welded to each other, and a metal layer 5 formed of a welding material is laminated. The groove 4 extends in an oblique direction intersecting the horizontal plane and opens in the horizontal direction. The direction in which the groove 4 extends is referred to as the first oblique direction. Among the first oblique directions, the upward side is referred to as the upper side and the downward side is referred to as the lower side.

[0014] The two diagonal members 2 and 3 are each long plate-shaped members. The two diagonal members 2 and 3 are arranged such that their plate surfaces are vertical planes and extend in a second oblique direction orthogonal to the first oblique direction. The directions in which the plate surfaces of the two diagonal members 2 and 3 face, that is, the thickness directions of the two diagonal members 2 and 3, are the same as the direction in which the groove 4 opens. Among the two diagonal members 2 and 3, the diagonal member arranged on the lower side in the first oblique direction is referred to as the first diagonal member 2 (first member), and the diagonal member arranged on the upper side is referred to as the second diagonal member 3 (second member). The end face of the first diagonal member 2 welded to the second diagonal member 3 is referred to as the first end face 21. The end face of the second diagonal member 3 welded to the first diagonal member 2 is referred to as the second end face 31.

[0015] The first end face 21 is a surface perpendicular to the plate surface of the first diagonal member 2. The first end face 21 extends in the first diagonal direction. The second end face 31 is a surface that intersects the plate surface of the second diagonal member 3 at an angle. The edge of the second end face 31 is positioned on the side of the second diagonal direction of the second diagonal member 3 that is closer to the center than one edge in the thickness direction of the second diagonal member 3. The second end face extends in the first diagonal direction. The groove 4 widens in height (groove width) from one side to the other in the thickness direction of the first diagonal member 2 and the second diagonal member 3. The groove 4 opens to the other side in the thickness direction of the first diagonal member 2 and the second diagonal member 3. In this embodiment, a backing plate 41 is provided on one side of the groove 4 in the thickness direction, covering the groove 4 from that side. The backing plate 41 is joined to the first diagonal member 2 and the second diagonal member 3.

[0016] As shown in Figure 3, metal layers 5 formed from the welding material are stacked in the groove 4 from one side in the thickness direction to the other, that is, from the back of the groove 4 to the opening. The metal layer 5 is a layer whose surface is oriented approximately in the thickness direction and is approximately a vertical surface. In conventional welding methods, as shown in Figure 4, the metal layers are stacked in a direction that gradually moves upward from one side in the thickness direction to the other. In conventional welding methods, the shape of the bead is unstable, and the thickness of the layers varies due to the influence of gravity. For this reason, automatic welding is difficult with conventional welding methods.

[0017] As shown in Figures 5 and 6, the welding apparatus 1 used in the welding method according to this embodiment includes a welding torch 6, a moving means for moving the welding torch 6, a moving control unit for controlling the moving means, and a posture control unit for controlling the posture of the welding torch 6. The welding apparatus 1 is capable of automatic welding. Figure 5 shows the welding torch 6 performing welding along the first end face 21. Figure 6 shows the welding torch 6 performing welding along the second end face 31.

[0018] The welding torch 6 generates an arc discharge at its tip, melting the supplied wire 51. The wire 51 is discharged linearly in the axial direction from the center of the nozzle 61. In this embodiment, the tip portion 611 of the nozzle 61 of the welding torch 6 is a frustoconical shape that tapers from the base end to the tip end. The base portion 612 of the nozzle 61 is cylindrical. The corner at the boundary between the tip portion 611 and the base portion 612 is referred to as the nozzle corner 613. The means of movement is a vertical articulated robot, etc. The means of movement is capable of moving and changing the orientation of the welding torch 6. The means of movement is capable of weaving the welding torch 6.

[0019] The welding method of this embodiment using the welding apparatus 1 described above will now be explained. In the welding method of this embodiment, a metal layer 5 is formed by moving the welding torch 6 from the bottom to the top in the first oblique direction while weaving, and the metal layer 5 is stacked in the depth direction of the groove 4 (stacking process). The weaving path 7 is shown in Figure 7. By forming the metal layer 5 in this way, it is possible to form a metal layer 5 that extends in the vertical direction and the first oblique direction and whose surface is substantially a vertical plane.

[0020] Weaving is performed by repeating the following first, second, third, and fourth operations in this order, from the lower side to the upper side in the first oblique direction of the groove 4. Since weaving is performed for each metal layer 5, the groove 4 is not moved in the depth direction. In Figure 7, the path of the first operation is indicated by the symbol "71", the path of the second operation by the symbol "72", the path of the third operation by the symbol "73", and the path of the fourth operation by the symbol "74". The first movement is to move a predetermined distance upward in the first diagonal direction along the first end face 21. The distance traveled in the first diagonal direction during the first movement is denoted as the first distance dx1. The second movement is to move horizontally from the end position of the first movement on the first end face 21 to the second end face 31. The second movement ends when the second end face 31 is reached. The third movement is to move a predetermined distance upward in the first diagonal direction along the second end face 31 from the end position of the second movement. The fourth movement is to move diagonally, gradually downward from the end position of the third movement to the first end face. The fourth movement ends when the first end face 21 is reached. The end position of the fourth movement is higher than the final position of the first movement that preceded it. The distance between the final position of the first movement and the end position of the fourth movement in the first diagonal direction is denoted as the second distance dx2. The first, second, third, and fourth operations are repeated until one metal layer 5 is formed, at which point another metal layer 5 is formed on the other side of the thickness direction of that metal layer 5 in the same manner.

[0021] As described above, the groove 4 widens in height (groove width) from one side to the other in the thickness direction. Therefore, the height dimension differs for each metal layer 5, and the width (height) of the weaving also differs. In the welding method of this embodiment, a metal layer vertical width calculation step is performed to calculate the vertical width dimension of each metal layer 5 to be formed, and a weaving path determination step is performed to determine the weaving path 7 according to the vertical width dimension of the metal layer 5 determined in the metal layer vertical width calculation step. Weaving is then performed along the weaving path 7 determined in the weaving path determination step. The welding apparatus 1 is provided with means for calculating the vertical width dimension of each metal layer 5 to be formed, and means for determining the weaving path 7 according to the vertical width dimension of the metal layer 5 calculated by means of means.

[0022] The vertical width dimension of metal layer 5, calculated by the metal layer vertical width calculation process, corresponds to the weaving width of each metal layer 5. In the metal layer vertical width calculation process, the weaving width of metal layer 5 is calculated using the following formula (1), referring to Figure 8.

[0023]

number

[0024] Gap: Height dimension (mm) of one end of the groove 4 in the thickness direction. angle: The angle of inclination (°) when the second end face 31 is viewed from a horizontal direction perpendicular to the thickness direction, groove angle. l0: Thickness dimension of the first diagonal member 2 and the second diagonal member 3 l n : The distance (mm) from the other side of the thickness direction of the last laminated metal layer 5 to the other end faces of the thickness direction of the first diagonal member 2 and the second diagonal member 3, remaining amount height n : The height dimension from the first end face 21 to the second end face 31 of the last laminated metal layer 5. l n height n The "n" in this equation represents the number of already stacked metal layers 5, i.e., the number of passes.

[0025] In the weaving path determination process, the weaving path is determined by calculating the first distance dx1 along the first diagonal direction traveled in the first movement described above, and the second distance dx2 along the first diagonal direction between the final position of the first movement and the end position of the fourth movement. In the weaving path determination process, the first distance dx1 and the second distance dx2 are set to satisfy the following equations (2) to (5).

[0026]

number

[0027] In the weaving path determination process, as shown in FIG. 7, the start position of the first operation is indicated as P1, the start position of the second operation (the end position of the first operation) is indicated as P2, the start position of the third operation (the end position of the second operation) is indicated as P3, the start position of the fourth operation (the end position of the third operation) is indicated as P4, and the end position of the fourth operation (the start position of the next first operation) is indicated as P5. The x direction of the coordinates is the first diagonal direction, and the y direction is the second diagonal direction. The first distance dx1 is the distance connecting P1 and P2, and the second distance dx2 is the distance connecting P2 and P5. In the above formulas (3) and (4), h is the dimension in the y direction (the second diagonal direction) from the first end face 21 to the second end face 31 of the last laminated metal layer 5.

[0028] The posture control unit controls the posture of the welding torch 6 as follows. When performing welding along the first end face in the first operation, the posture control unit controls the posture of the welding torch 6 such that the tip of the wire 51 to be welded reaches the first end face 21 and the side face 62 of the tip portion of the nozzle 61 of the welding torch 6 contacts the second end face 31. When performing welding along the second end face 31 in the third operation, the posture control unit controls the posture of the welding torch 6 such that the tip of the wire 51 to be welded reaches the second end face 31 and the side face 62 of the tip portion of the nozzle 61 of the welding torch 6 contacts the second end face 31.

[0029] In the present embodiment, with reference to FIGS. 9 and 10, the presence or absence of interference between the welding torch 6 and the second end face 31 when performing welding along the second end face 31 in the third operation is examined as follows.

[0030] In the examination, when the angle of the welding torch 6 is 0° as shown in FIG. 9, the tip position of the wire 51 in the welding torch 6 is P 00 , the tip position of the nozzle 61 is P 01 , and the position of the nozzle corner 613 of the nozzle 61 is P 02 are shown. P 00 , P 01 , P 02The coordinates are expressed by the following equations (6), (7), and (8). The x-direction of the coordinates is the depth direction of groove 4, and the y-direction is the height direction. Tip position P of wire 51 00 From the tip position P of nozzle 61 01 l1 is the distance to the tip of nozzle 61, and P is the tip position of nozzle 61. 01 From position P of the nozzle corner 613 of nozzle 61 02 The distance to is denoted as l2. The tip position P of the nozzle 61. 01 Let d1 be the diameter, and P be the position of the nozzle corner 613 of the nozzle 61. 02 Let the diameter be denoted as d2.

[0031]

number

[0032] In Figure 10, when the angle of the welding torch 6 is θ, the tip position of the nozzle 61 is denoted as P1, and the position of the nozzle corner 613 of the nozzle 61 is denoted as P2. The coordinates of P1 and P2 are expressed as follows.

[0033]

number

[0034] The straight line f1 connecting P1 and P2 and the straight line f2 along the surface of the second end face 31 are expressed by the following equations (9) and (10). Here, the inclination angle of the second end face 31 is α. The height dimension of one end of the groove 4 in the thickness direction is defined as gap.

[0035]

number

[0036] If straight line f1 and straight line f2 are parallel and their intersection point is outside groove 4, then the welding torch 6 and groove 4 will not interfere with each other.

[0037] In the welding method and welding apparatus 1 according to this embodiment, by weaving the welding torch 6 while switching the position of the welding torch 6, a metal layer 5 that extends vertically and has height along the direction in which the groove 4 extends can be formed in a stable state. As a result, the shape of the metal layer 5 (bead) is stabilized, making it possible to control the shape of the metal layer 5 and the direction in which the metal layers 5 are stacked. Therefore, it is possible to automatically weld diagonal members with grooves 4 extending diagonally together.

[0038] Furthermore, the welding method according to this embodiment includes a metal layer vertical width calculation step for calculating the vertical width dimension of each metal layer 5 to be formed, and a weaving path determination step for determining the weaving path 7 according to the vertical width dimension of the metal layer 5 calculated in the metal layer vertical width calculation step, and in the lamination step, weaving is performed along the weaving path determined in the weaving path determination step. This allows for the determination of the weaving path 7 according to the vertical width dimension of the formed metal layer 5, thereby stabilizing the shape of the metal layer 5 and enabling automatic welding of diagonal members with grooves extending diagonally.

[0039] Although embodiments of the welding method and welding apparatus according to the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. For example, the posture control unit may control the posture of the welding torch 6 when welding along the first end face 21 in the first operation and the posture of the welding torch 6 when welding along the second end face 31 in the third operation to postures other than those described above.

[0040] The Sustainable Development Goals (SDGs) are among the 17 international goals adopted at the UN Summit in September 2015. The welding method and welding apparatus according to this embodiment can contribute to achieving goals such as "Goal 9: Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation," among the 17 Sustainable Development Goals (SDGs). [Explanation of symbols]

[0041] 1. Welding equipment 2. First diagonal member (first component) 3. Second diagonal member (second component) 4 Bevel 5 metal layer 6. Welding Torch 7. Weaving Path 21,31 End face 51 wire

Claims

1. The process involves forming a groove between the end faces of a first member and a second member to be welded together, extending in an oblique direction intersecting a horizontal plane and having a depth direction that is horizontal, and weaving a welding torch that melts the welding material into the groove with a moving means, thereby forming metal layers extending in the oblique and vertical directions with the molten welding material, and stacking the metal layers in the depth direction. The weaving is performed for each of the metal layers, A first movement that proceeds in an upward direction along the end face of the first member, Following the first movement, a second movement is performed, which moves horizontally from the end face of the first member to the end face of the second member, Following the second operation, a third operation proceeds in an upward direction along the end face of the second member, Following the third operation, a fourth operation is performed, which involves gradually moving downward from the end face of the second member to the end face of the first member, and this is repeated in this order. A welding method for switching the position of the welding torch in the first operation and the position of the welding torch in the third operation.

2. A metal layer vertical width calculation step for calculating the vertical width dimension of each metal layer to be formed, The process includes a weaving path determination step which determines the weaving path according to the vertical width dimension of the metal layer calculated in the metal layer vertical width calculation step, The welding method according to claim 1, wherein the lamination step is performed along the weaving path determined in the weaving path determination step.

3. A welding torch that melts the welding material, A means for moving the welding torch, A movement control unit that controls the aforementioned movement means, The welding torch has a posture control unit that controls the posture of the welding torch, The aforementioned movement control unit, A groove is formed between the end faces of a first member and a second member to be welded together, extending diagonally in a direction intersecting the horizontal plane and with a depth direction that is horizontal. The welding torch is weaved through this groove to form metal layers extending diagonally and vertically with the molten welding material, and the metal layers are controlled to be stacked in the depth direction. The weaving is performed for each of the metal layers, A first movement that proceeds in an upward direction along the end face of the first member, Following the first movement, a second movement is performed, which moves horizontally from the end face of the first member to the end face of the second member, Following the second operation, a third operation proceeds in an upward direction along the end face of the second member, Following the third operation, a fourth operation is performed, which involves gradually moving downward from the end face of the second member to the end face of the first member, and this sequence is repeated. The attitude control unit, A welding apparatus for controlling the position of the welding torch in the first operation and the position of the welding torch in the third operation.

Images