Welding apparatus and method and program

Abstract

To improve welding accuracy in a welding apparatus, a welding method, and a welding program.SOLUTION: This welding apparatus for an object to be welded, which is formed by connecting a first member, a second member, and a third member so as to be orthogonal, comprises: a welding robot; and a control device that controls the welding robot. The control device calculates first three-dimensional measurement data containing the position of a first direction in the first member and the inclination of a second direction orthogonal to the first direction, calculates second three-dimensional measurement data containing the position of the second direction in the first member, calculates third three-dimensional measurement data containing the position of a third direction orthogonal to the first and second directions in the second member and the inclination of the second direction, defines three-dimensional coordinates of the object to be welded with respect to a reference point in the welding robot on the basis of three-dimensional design data of the object and the first, second and third three-dimensional measurement data, and controls the welding robot on the basis of the three-dimensional coordinates of the object to be welded to perform weld.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a welding apparatus, method, and program for performing welding using a robot.

Background Art

[0002] When performing an automatic welding operation using a welding robot, the welding object is fixed at a predetermined position, and the welding position on the welding object is detected by touch sensing or the like. Then, by automatically controlling the welding robot, the welding torch is moved along the welding position to perform welding. Examples of such welding apparatuses include those described in the following patent documents.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when welding along the welding position of the welding object, thermal distortion occurs in the welding object. When thermal distortion occurs in the welding object, there is a problem that the welding position for the next welding is shifted and the welding accuracy is reduced.

[0005] The present disclosure solves the above-described problems and aims to provide a welding apparatus, method, and program for improving welding accuracy.

Means for Solving the Problems

[0006] A welding apparatus of the present disclosure for achieving the above objective is a welding apparatus for a workpiece configured by connecting a first member, a second member, and a third member orthogonally, comprising a welding robot and a control device for controlling the welding robot, wherein the control device calculates first three-dimensional measurement data having a position in a first direction and an inclination in a second direction orthogonal to the first direction in the first member, calculates second three-dimensional measurement data having a position in a second direction in the first member, calculates third three-dimensional measurement data having a position in a third direction orthogonal to the first and second directions in the second member and an inclination in the second direction, defines the three-dimensional coordinates of the workpiece with respect to a reference point in the welding robot based on the three-dimensional design data of the workpiece, the first three-dimensional measurement data, the second three-dimensional measurement data, and the third three-dimensional measurement data, and controls the welding robot based on the three-dimensional coordinates of the workpiece to perform welding.

[0007] Furthermore, the welding method of the present disclosure is a welding method for an object to be welded, which is composed of a first member, a second member, and a third member connected together, and comprises the steps of: calculating first three-dimensional measurement data having a position in a first direction and an inclination in a second direction perpendicular to the first direction in the first member; calculating second three-dimensional measurement data having a position in a second direction in the first member; calculating third three-dimensional measurement data having a position in a third direction perpendicular to the first and second directions in the second member and an inclination in the second direction; defining the three-dimensional coordinates of the object to be welded with respect to a reference point in a welding robot based on three-dimensional design data of the object to be welded, the first three-dimensional measurement data, the second three-dimensional measurement data, and the third three-dimensional measurement data; and performing welding by controlling the welding robot based on the three-dimensional coordinates of the object to be welded.

[0008] Furthermore, the program of this disclosure is a program for welding a weldable object composed of a first member, a second member, and a third member connected together, and causes a computer operating as a welding device to execute the following steps: calculating first three-dimensional measurement data having a position in a first direction and an inclination in a second direction perpendicular to the first direction in the first member; calculating second three-dimensional measurement data having a position in a second direction in the first member; calculating third three-dimensional measurement data having a position in a third direction perpendicular to the first and second directions in the second member and an inclination in the second direction; defining the three-dimensional coordinates of the weldable object with respect to a reference point in a welding robot based on three-dimensional design data of the weldable object, the first three-dimensional measurement data, the second three-dimensional measurement data, and the third three-dimensional measurement data; and controlling the welding robot based on the three-dimensional coordinates of the weldable object to perform welding. [Effects of the Invention]

[0009] The welding apparatus, method, and program of this disclosure can improve welding accuracy. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic plan view representing the welding apparatus of this embodiment. [Figure 2] Figure 2 is a schematic diagram showing the welding apparatus. [Figure 3] Figure 3 is a flowchart illustrating the welding method using the welding apparatus of this embodiment. [Figure 4] Figure 4 is a schematic diagram showing the sensing locations when setting the coordinates of the support legs. [Figure 5] Figure 5 is a schematic diagram showing the sensing locations when setting the coordinates of the support legs. [Figure 6] Figure 6 is a schematic diagram showing the sensing locations when setting the coordinates of the support legs. [Figure 7]FIG. 7 is a schematic diagram showing sensing positions during correction of the instruction position of the support leg. [Figure 8] FIG. 8 is a schematic diagram showing sensing positions during correction of the instruction position of the support leg. [Figure 9] FIG. 9 is an explanatory diagram showing a welded portion along the horizontal direction. [Figure 10] FIG. 10 is an explanatory diagram showing a welded portion along the vertical direction. [Figure 11] FIG. 11 is a perspective view showing the support leg. [Figure 12] FIG. 12 is a plan view showing the support leg. [Figure 13] FIG. 13 is a plan view showing the positioner of the support leg. [Figure 14] FIG. 14 is a side view showing the positioner of the support leg.

MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited by this embodiment, and when there are multiple embodiments, those configured by combining each embodiment are also included. In addition, the constituent elements in the embodiment include those that can be easily assumed by those skilled in the art, substantially the same ones, and those within the so-called equivalent range.

[0012] [First Embodiment] <Support Leg> FIG. 11 is a perspective view showing the support leg, and FIG. 12 is a plan view showing the support leg. In the following description, the width direction (horizontal direction) of the support leg will be described as the X direction, the longitudinal direction (horizontal direction) of the support leg will be described as the Y direction, and the vertical direction of the support leg will be described as the Z direction.

[0013] In this embodiment, in FIGS. 11 and 12, the object to be welded is the support leg 100. The support leg 100 is, for example, for placing and supporting a large structure. The support leg 100 is composed of one bottom plate 101, two side plates 102 and 103, one support plate 104, and six ribs 105, 106, 107, 108, 109, and 110.

[0014] The bottom plate 101 has a plate shape along the X and Y directions, and the length in the Y direction is longer than the length in the X direction. The lower parts of the side plates 102 and 103 are connected to each end in the Y direction of the bottom plate 101. The side plates 102 and 103 have a plate shape along the X and Z directions, and the length in the Z direction is longer than the length in the X direction. The support plate 104 is connected to the inside of the bottom plate 101 and the side plates 102 and 103. The support plate 104 has a plate shape along the Y and Z directions, and the length in the Y direction is longer than the length in the Z direction. The lower part of the support plate 104 is connected to the bottom plate 101, and each side part is connected to the side plates 102 and 103 respectively. The support plate 104 is arranged at the intermediate position in the X direction with respect to the bottom plate 101 and the side plates 102 and 103. Also, the upper part of the support plate 104 has a curved shape that is concave downward in the Z direction.

[0015] The ribs 105, 106, 107, 108, 109, and 110 are connected to the bottom plate 101 and the support plate 104. The ribs 105, 106, 107, 108, 109, and 110 have a plate shape along the X and Z directions. The ribs 105, 106, 107, 108, 109, and 110 are connected so as to be orthogonal to the bottom plate 101 and the support plate 104. The ribs 105, 106, 107, and 108 have the same shape, and the ribs 109 and 110 have the same shape. The ribs 105, 106, 107, 108, 109, and 110 have the same length in the X direction, and the length in the Z direction of the ribs 105, 106, 107, and 108 is longer than the length in the Z direction of the ribs 109 and 110.

[0016] Ribs 109 and 110 are positioned at an intermediate position in the Y direction between side plates 102 and 103. Ribs 105 and 106 are positioned at an intermediate position in the Y direction between side plate 102 and ribs 109 and 110. Ribs 107 and 108 are positioned at an intermediate position in the Y direction between side plate 103 and ribs 109 and 110. Ribs 105 and 106, ribs 107 and 108, and ribs 109 and 110 are each positioned at the same location in the Y direction.

[0017] <Positioner> Figure 13 is a plan view showing the positioner of the support leg, and Figure 14 is a side view showing the positioner of the support leg.

[0018] As shown in Figures 13 and 14, the positioner 120 supports the support legs 100. The positioner 120 includes a base plate 121, a backing plate 122, an insulating material (heat-insulating material) 123, and a heater 124. The base plate 121 is a plate material of a predetermined thickness, and its levelness is ensured. Multiple backing plates 122 are fixed to the upper surface of the base plate 121. The multiple backing plates 122 are block-shaped with a predetermined thickness and are all the same shape. The multiple backing plates 122 are arranged at predetermined intervals in the X and Y directions and are fixed, for example, by welding. The lower surface of the bottom plate 101 of the support legs 100 rests on the upper surface of the multiple backing plates 122. The multiple backing plates 122 are arranged to support support legs 100 of different sizes. Therefore, a space equal to the thickness of the contact plate 122 is secured between the upper surface of the base plate 121 and the lower surface of the bottom plate 101 of the support leg 100.

[0019] The surface plate 121 has an insulating material 123 placed on its upper surface, excluding the multiple backing plates 122. The thickness of the insulating material 123 is thinner than the thickness of the backing plates 122. Multiple heaters (heating devices) 124 are placed on the upper surface of the insulating material 123. The multiple heaters 124 are placed at predetermined intervals in the X direction. The heaters 124 are, for example, electric heaters, but other types of heaters may also be used. Here, the multiple backing plates 122 are arranged to form a frame, and the multiple heaters 124 are placed inside the multiple backing plates 122. Alternatively, the multiple backing plates 122 may be placed between the multiple heaters 124. The thickness of the heaters 124 is thinner than the thickness of the backing plates 122. The combined thickness of the insulating material 123 and the heaters 124 is thinner than the thickness of the backing plates 122. Therefore, a small gap is secured between the upper surface of the heaters 124 and the lower surface of the bottom plate 101 of the support legs 100. The upper surface of the heater 124 may be in contact with the lower surface of the bottom plate 101 of the support leg 100, but it is preferable that the load of the support leg 100 does not act on the heater 124. In addition, the heat insulating material 123 may be placed in the space between the base plate 121 and the support leg 100 where the heater 124 is not located.

[0020] The support legs 100 are placed on a plurality of backing plates 122 arranged on a surface plate 121. The support legs 100 are positioned so that their centers are at the center of the positioner 120. Once the support legs 100 are positioned in the predetermined location on the positioner 120, their base plates 101 are fixed to the plurality of backing plates 122, for example, by welding. At this time, the lower surface of the base plate 101 of the support legs 100 faces a plurality of heaters 124. Therefore, the support legs 100 can be heated by the plurality of heaters 124 via the base plate 101. Because the base plate 101 of the support legs 100 is thick, it is necessary to heat it with the heaters 124 before welding to suppress welding defects such as cold cracks and deformation during welding.

[0021] <Welding equipment> Figure 1 is a schematic plan view representing the welding apparatus of this embodiment, and Figure 2 is a schematic configuration diagram representing the welding apparatus.

[0022] In this embodiment, as shown in Figures 1 and 2, the welding apparatus 10 manufactures the support leg 100 by welding together the bottom plate 101, the side plates 102, 103, the support plate 104, and the ribs 105, 106, 107, 108, 109, and 110. The support leg 100 is formed by tack welding, connecting the bottom plate 101, the side plates 102, 103, the support plate 104, and the ribs 105, 106, 107, 108, 109, and 110. The welding apparatus 10 then performs final welding to connect the bottom plate 101, the side plates 102, 103, the support plate 104, and the ribs 105, 106, 107, 108, 109, and 110.

[0023] The welding apparatus 10 comprises a first welding robot 11, a second welding robot 12, and a control device 13.

[0024] The support legs 100 are supported by a positioner 120. The first welding robot 11 is positioned on one side in the X direction relative to the support legs 100. The second welding robot 12 is positioned on the other side in the X direction relative to the support legs 100. That is, the first welding robot 11 and the second welding robot 12 face each other with the support legs 100, which are supported by the positioner 120, in between. The first welding robot 11 is positioned on a support base 21 and is supported so as to be movable along the Y direction. The second welding robot 12 is positioned on a support base 31 and is supported so as to be movable along the Y direction. The first welding robot 11 and the second welding robot 12 have substantially the same configuration.

[0025] The first welding robot 11 has a first articulated arm 22, and a first welding torch 23 is attached to the tip of the first articulated arm 22. The first welding robot 11 also has a first touch probe 24 and a first temperature sensor 25 attached to the tip of the first articulated arm 22. The second welding robot 12 has a second articulated arm 32, and a second welding torch 33 is attached to the tip of the second articulated arm 32. The second welding robot 12 also has a second touch probe 34 and a second temperature sensor 35 attached to the tip of the second articulated arm 32.

[0026] The first welding robot 11 is connected to the first robot control unit 26. The first robot control unit 26 controls the welding work performed by the first welding robot 11 based on a preset program. The second welding robot 12 is connected to the second robot control unit 36. The second robot control unit 36 ​​controls the welding work performed by the second welding robot 12 based on a preset program. The first robot control unit 26 is also connected to the first display device 27, and the second robot control unit 36 ​​is also connected to the second display device 37. The first display device 27 and the second display device 37 can display various data related to the welding work performed by the first welding robot 11 and the second welding robot 12. For example, the first display device 27 and the second display device 37 can display images of the welding work (such as the welding bead) captured by a CCD camera located at the tip of an articulated arm 22, 32 (not shown). The first display device 27 and the second display device 37 can also display the remaining amount of welding wire, the timing for replacing the welding tip, etc.

[0027] The control device 13 is connected to the first robot control unit 26 and the second robot control unit 36. The control device 13 can control the first welding robot 11 and the second welding robot 12 via the first robot control unit 26 and the second robot control unit 36. An input device 14 is connected to the control device 13. The input device 14 is connected to various databases, and the operator can input various data stored in the databases to the control device 13 using the input device 14. In addition, the control device 13 is connected to the first touch probe 24 and the first temperature sensor 25 and the second touch probe 34 and the second temperature sensor 35. The control device 13 receives the measurement results from the first touch probe 24 and the first temperature sensor 25 and the second touch probe 34 and the second temperature sensor 35.

[0028] Specifically, the control device 13 controls the first welding robot 11 and the second welding robot 12 to simultaneously weld the first and second welding lines on both sides of the symmetry axis L in the support leg 100. The support leg 100 has multiple welding sections A1, B1, C1, D1, A2, B2, C2, and D2.

[0029] The first welding robot 11 and the second welding robot 12 simultaneously weld the first and second welding lines that are positioned opposite each other to the support plate 104. That is, the first welding robot 11 welds the welding sections A1, B1, C1, and D1 of the support leg 100 in that order. The second welding robot 12 welds the welding sections A2, B2, C2, and D2 of the support leg 100 in that order. While the first welding robot 11 is welding welding section A1 of the support leg 100, the second welding robot 12 is welding welding section A2 of the support leg 100. The first welding robot 11 and the second welding robot 12 similarly weld the other welding sections B1, C1, D1, B2, C2, and D2.

[0030] Furthermore, the first welding robot 11 and the second welding robot 12 may simultaneously weld the first and second welding lines that are diagonally opposite each other with respect to the support plate 104. That is, the first welding robot 11 welds the welding sections A1, B1, C1, and D1 of the support leg 100 in that order. The second welding robot 12 welds the welding sections B2, A2, D2, and C2 of the support leg 100 in that order. At the same time that the first welding robot 11 welds the welding section A1 of the support leg 100, the second welding robot 12 welds the welding section B2 of the support leg 100. The first welding robot 11 and the second welding robot 12 also simultaneously weld the other welding sections, specifically welding sections B1, A2, C1, D2, and D1, C2.

[0031] The support legs 100 have a line-symmetric shape in the X direction with respect to the axis of symmetry L. As shown in Figures 11 and 12, in welding section A1, the first welding robot 11 performs welding along welding lines a11, a12, and a13. At this time, the first welding robot 11 forms a layered weld bead by moving back and forth multiple times along the welding lines a11, a12, and a13, which are the first welding lines. For welding line a11, the first welding torch 23 (see Figure 1) is moved in a U-shape along the horizontal direction (X and Y directions) to weld and connect the bottom plate 101 to the ribs 105 and 109, and the bottom plate 101 to the support plate 104, respectively. For welding line a12, the first welding torch 23 is moved in the vertical direction (Z direction) to weld and connect the rib 105 to the support plate 104. Weld line a13 is created by moving the first welding torch 23 along the vertical direction (Z direction) to weld and connect the rib 109 and the support plate 104. The same applies to the second welding robot 12 that performs welding in welding area A2, and weld lines a21, a22, and a23 are set as second welding lines.

[0032] Here, the first weld lines (weld lines a11, a12, a13) of welding area A1, which is the first welding area, and the second weld lines (weld lines a21, a22, a23) of welding area A2, form a symmetrical shape with respect to the axis of symmetry L of the support leg 100. However, the welding directions of weld line a11 and weld line a21 are opposite. Furthermore, the first weld lines (weld lines a11, a12, a13) and the second weld lines (weld lines a21, a22, a23) are of the same length. The same applies to the other welding areas B1, C1, D1, B2, C2, and D2.

[0033] As shown in Figures 1 and 2, the control device 13 simultaneously starts welding operations by the first welding robot 11 and the second welding robot 12. The first welding robot 11 moves the first welding torch 23 along the first welding line, while the second welding robot 12 moves the second welding torch 33 along the second welding line. In other words, by controlling the first welding robot 11 and the second welding robot 12, the control device 13 simultaneously performs welding operations in welding section A1 on one side of the support plate 104 and welding operations in welding section A2 on the other side. Once the welding operations in welding section A1 and welding section A2 are completed, the control device 13 starts welding operations in the next welding sections B1 and B2.

[0034] The control device 13 defines the position of the support leg 100 relative to the respective reference points in the first welding robot 11 and the second welding robot 12, based on the three-dimensional design data of the support leg 100 and the three-dimensional measurement data of the support leg 100 positioned by the positioner 120. The three-dimensional design data of the support leg 100 is stored in a database, for example, as a drawing. The operator inputs the three-dimensional design data of the support leg 100 stored in the database into the control device 13 using the input device 14.

[0035] The control device 13 measures the arrangement of the support legs 100 using either the touch probes 24 or 34 provided on the first welding robot 11 or the second welding robot 12, and calculates three-dimensional measurement data. In this case, the measurement of the arrangement of the support legs 100 is not limited to using the touch probes 24 or 34; for example, a wire touch sensor that detects the wire coming out of the welding torches 23 or 33 by energizing it may also be used. Based on the three-dimensional design data and three-dimensional measurement data of the support legs 100, the control device 13 defines the position of the support legs 100 relative to the respective reference points (three-dimensional coordinates) on the first welding robot 11 and the second welding robot 12 as three-dimensional coordinates. The method for calculating the three-dimensional measurement data and the method for defining the three-dimensional coordinates of the support legs 100 will be described later.

[0036] The control device 13 measures the positions of the base plate 101, side plates 102, 103, support plate 104, and ribs 105, 106, 107, 108, 109, 110 that form the first and second weld lines, and corrects the position of the support legs 100 as defined based on the measured position data of the support legs 100. The support legs 100 are temporarily connected based on the 3D design data and fixed to a predetermined position on the positioner 120. However, the 3D design data does not take into account manufacturing errors, assembly errors, positioning errors on the positioner 120, etc. of the side plates 102, 103, support plate 104, and ribs 105, 106, 107, 108, 109, 110. Furthermore, the 3D measurement data is obtained by measuring the support legs 100 using touch probes 24, 34. However, the 3D measurement data has a limited number of measurement points on the support legs 100. Also, deformation of the support legs 100 after welding is not taken into consideration. Therefore, the control device 13 measures the positions of the first and second weld lines for each welding section A1, B1, C1, D1, A2, B2, C2, and D2. The method for measuring the positions of the first and second weld lines will be described later.

[0037] The control device 13 starts welding operations by the first welding robot 11 and the second welding robot 12 when the temperature of the support leg 100 reaches a preset welding temperature range. The control device 13 receives the measurement results from the temperature sensors 25 and 35 installed on the first welding robot 11 and the second welding robot 12. The control device 13 keeps the welding operations by the first welding robot 11 and the second welding robot 12 on standby until the temperature of the support leg 100, as input from the temperature sensors 25 and 35, reaches the welding temperature range.

[0038] <Welding Method> Figure 3 is a flowchart illustrating the welding method using the welding apparatus of this embodiment; Figures 4 to 6 are schematic diagrams showing sensing points when setting the coordinates of the support legs; Figures 7 and 8 are schematic diagrams showing sensing points when correcting the teaching position of the support legs; Figure 9 is an explanatory diagram showing a weld along the horizontal direction; and Figure 10 is an explanatory diagram showing a weld along the vertical direction.

[0039] In the following explanation, we describe the case where the first welding robot 11 and the second welding robot 12 simultaneously weld a first weld line and a second weld line that are positioned opposite each other with respect to the support plate 104. However, the same applies when the first welding robot 11 and the second welding robot 12 simultaneously weld a first weld line and a second weld line that are positioned diagonally opposite each other with respect to the support plate 104.

[0040] In the welding method using the welding apparatus of this embodiment, as shown in Figures 1 to 3, in step S11, the operator places the support leg 100 on the positioner 120. In this case, the support leg 100 is positioned and fixed so that its center is located at the center of the positioner 120. In step S12, the operator inputs the 3D design data of the support leg 100 stored in the database to the control device 13 using the input device 14. In step S13, the operator senses the position of the support leg 100 using the first touch probe 24 of the first welding robot 11 via the control device 13.

[0041] First, as shown in Figure 4, the first touch probe 24 is moved in the Y direction from one side of the support leg 100 toward the outer surface of the side plate 102, and stopped at position P1 where the tip of the first touch probe 24 makes contact. At this time, the Y-coordinate of position P1 with respect to the reference point of the first welding robot 11 is determined. The first touch probe 24 is then shifted in the X direction and similarly moved in the Y direction from one side of the support leg 100 toward the outer surface of the side plate 102, and stopped at position P2 where the tip of the first touch probe 24 makes contact. At this time, the Y-coordinate of position P2 with respect to the reference point of the first welding robot 11 is determined. Then, based on the Y-coordinates of positions P1 and P2, the Y-direction position and X-direction inclination of the side plate 102 are calculated.

[0042] Furthermore, as shown in Figure 5, the first touch probe 24 is moved in the X direction from the front of the support leg 100 toward the end face of the side plate 102, and stops at position P3 where the tip of the first touch probe 24 makes contact. At this time, the X-direction coordinate of position P3 with respect to the reference point of the first welding robot 11 is determined. Then, the X-direction position on the side plate 102 is calculated based on the X-direction position coordinate of position P3.

[0043] Furthermore, as shown in Figure 6, the first touch probe 24 is moved in the Z direction from above the support leg 100 toward the upper surface of the base plate 101 and stopped at position P4 where the tip of the first touch probe 24 makes contact. At this time, the Z coordinate of position P4 with respect to the reference point of the first welding robot 11 is determined. The first touch probe 24 is shifted in the X direction and similarly moved in the Z direction from above the support leg 100 toward the upper surface of the base plate 101 and stopped at position P5 where the tip of the first touch probe 24 makes contact. At this time, the Z coordinate of position P5 with respect to the reference point of the first welding robot 11 is determined. Then, based on the Z coordinates of positions P4 and P5, the Z position and X inclination on the base plate 101 are calculated.

[0044] Next, moving the first touch probe 24 in the opposite direction to the one described above, that is, relative to the side plate 103 of the support leg 100 and the bottom plate 101 on the side plate 103, the position coordinates of positions P1, P2, P3, P4, and P5 are determined in the same way as described above.

[0045] As shown in Figures 1 to 3, in step S14, the control device 13 defines the position of the support leg 100 relative to the respective reference points (3D coordinates) of the first welding robot 11 and the second welding robot 12 as 3D coordinates, based on the 3D design data and 3D measurement data of the support leg 100.

[0046] Specifically, as shown in Figure 6, the three-dimensional coordinates in the X, Y, and Z directions of angle Pa, where the base plate 101, side plate 102, and support plate 104 are connected, are calculated based on the position coordinates P1, P2, P3, P4, and P5 of the support leg 100 measured from one side of the support leg 100. Similarly, the three-dimensional coordinates in the X, Y, and Z directions of angle Pb (not shown), where the base plate 101, side plate 103, and support plate 104 are connected, are calculated based on the position coordinates P1, P2, P3, P4, and P5 of the support leg 100 measured from the other side of the support leg 100. Once the three-dimensional coordinates of angle Pa and angle Pb are calculated, the three-dimensional coordinates of the center position O of the support leg are calculated based on the three-dimensional coordinates of angle Pa and angle Pb. Then, the three-dimensional coordinates of angle Pa and angle Pb are used to convert the support leg 100 into a three-dimensional coordinate system with the center position O of the support leg 100 as the origin.

[0047] As shown in Figures 1 to 3, in step S15, the control device 13 moves the tips of the first welding robot 11 and the second welding robot 12 to the target welding area. At the start of welding, the tip of the first welding robot 11 is moved to welding area A1, and the tip of the second welding robot 12 is moved to welding area A2. In step S16, the control device 13 senses the first welding lines (welding lines a11, a12, a13) and the second welding lines (welding lines a21, a22, a23) in welding areas A1 and A2, respectively, using the first welding robot 11 and the second welding robot 12.

[0048] Specifically, first, as shown in Figure 7, the first touch probe 24 is moved in the Z direction from above the support leg 100 toward the upper surface of the base plate 101, and stopped at position P11 where the tip of the first touch probe 24 makes contact. At this time, the Z coordinate of position P11 with respect to the origin (center position O) of the support leg 100 is determined. The first touch probe 24 is then shifted in the X direction and similarly moved in the Z direction from above the support leg 100 toward the upper surface of the base plate 101, and stopped at position P12 where the tip of the first touch probe 24 makes contact. At this time, the Z coordinate of position P12 with respect to the origin of the support leg 100 is determined. In this way, the Z position and inclination of the base plate 101 are calculated based on the Z position coordinates of 10 positions P11, P12, P13, P14, P15, P16, P17, P18, P19, P20 on the base plate 101 in the region along the weld line a11.

[0049] Next, the first touch probe 24 is moved in the X direction from the front of the support leg 100 toward the end face of the rib 105, and stopped at position P21 where the tip of the first touch probe 24 makes contact. At this time, the X-coordinate of position P21 relative to the origin of the support leg 100 is determined. Then, the X-direction position on the rib 105 is calculated based on the X-direction position coordinate of position P21. Similarly, the first touch probe 24 is moved in the X direction from the front of the support leg 100 toward the end face of the rib 109, and stopped at position P22 where the tip of the first touch probe 24 makes contact. At this time, the X-coordinate of position P22 relative to the origin of the support leg 100 is determined. Then, the X-direction position on the rib 109 is calculated based on the X-direction position coordinate of position P22.

[0050] Furthermore, as shown in Figure 8, the same method is used to determine the Y-coordinates of the planar positions P31, P32, and P33 of the rib 105 using the first touch probe 24. The X-coordinates of the planar positions P34 and P35 of the support plate 104 are also determined using the first touch probe 24. The Z-coordinate of the upper surface position P36 near the corner of the welding section A1 on the bottom plate 101 is also determined using the first touch probe 24. In this way, in the region along the welding line a12, the Y-coordinates of the rib 105 are calculated based on the Y-coordinates of the rib 105 positions P31, P32, and P33, and the X-coordinates of the support plate 104 are calculated based on the X-coordinates of the support plate 104 positions P34 and P35.

[0051] Similarly, in the region along the weld line a13, the Y-direction position and inclination of the rib 109 are calculated based on the Y-direction position coordinates of multiple locations on the rib 109, and the X-direction position and inclination of the support plate 104 are calculated based on the X-direction position coordinates of multiple locations on the support plate 104.

[0052] As shown in Figures 1 to 3, in step S17, the control device 13 determines the three-dimensional coordinates along the first weld line (welding lines a11, a12, a13) based on the position and inclination of the base plate 101, support plate 104, and ribs 105, 109 in the region along the first weld line (welding lines a11, a12, a13) obtained by sensing, and corrects the three-dimensional coordinates of the support leg 100 defined in step S14. That is, the three-dimensional coordinates of the welding area A1 at the support leg 100 defined in step S14 are replaced with the three-dimensional coordinates of the welding area A1 calculated from the measurement data obtained in step S16.

[0053] The control device 13 also performs the same processing for welding area A2, replacing the three-dimensional coordinates of welding area A2 at the support leg 100 defined in step S14 with the three-dimensional coordinates of welding area A2 calculated from the measurement data obtained in step S16.

[0054] In step S18, the control device 13 operates the first welding robot 11 and the second welding robot 12, and measures the temperature by bringing the temperature sensors 25 and 35 into contact with the vicinity of the weld lines in welding sections A1 and A2. In step S19, the control device 13 determines whether the temperature input from the temperature sensors 25 and 35 is within a preset welding temperature range. If it is determined that the temperature of welding sections A1 and A2 is not within the welding temperature range (No), the process returns to step S18.

[0055] On the other hand, if it is determined (Yes) that the temperatures of welding sections A1 and A2 are within the welding temperature range, in step S20, the control device 13 activates the first welding robot 11 and the second welding robot 12 to start welding work in welding sections A1 and A2. In this case, it is determined that the temperatures of both welding sections A1 and A2 are within the welding temperature range. The first welding robot 11 then welds in the order of welding lines a11, a12, and a13, and the second welding robot 12 welds in the order of welding lines a21, a22, and a23. The first welding robot 11 and the second welding robot 12 operate synchronously and simultaneously weld the first and second welding lines of welding sections A1 and A2 on both sides of the support plate 104.

[0056] The first welding robot 11 and the second welding robot 12 perform welding by moving back and forth along the welding line multiple times, thereby forming multiple layers of weld beads. Specifically, as shown in Figure 9, when the first welding robot 11 moves the first welding torch 23 along the welding line a11, it stacks the first layer "1", the second layers "2-1" and "2-2", the third layers "3-1", "3-2", "3-3" and "3-4", and the fourth layers "4-1", "4-2", "4-3", "4-4", "4-5" and "4-6". Similarly, as shown in Figure 10, when the first welding robot 11 moves the first welding torch 23 along the welding line a12, it stacks the first layer "1", the second layer "2", the third layer "3", and the fourth layer "4". The number of layers along welding lines a11, a12, and a13 is set appropriately according to the thickness of the material, and the number of layers described above is just an example and is not limited to this number.

[0057] In the above explanation, sensing is performed first along welding line a11, then along welding lines a12 and a13, followed by welding along welding line a11, then welding along welding line a12, and finally welding along welding line a13. However, the method is not limited to this procedure. For example, sensing may be performed first along welding line a11, then welding may be performed along welding line a11. After welding along welding line a11, sensing may be performed along welding lines a12 and a13, followed by welding along welding line a12, and finally welding along welding line a13. With this method, the thermal deformation of the support leg 100 due to welding line a11 can be detected when sensing along welding lines a12 and a13, and welding along welding lines a12 and a13 can be performed with high precision.

[0058] In step S21, the control device 13 determines whether welding of all layers at welding lines a11, a12, and a13 has been completed. If it is determined that welding of all layers has not been completed (No), then in step S22, it determines whether welding of N layers has been completed. That is, if welding of a predetermined layer is still in progress, it is determined that welding of N layers has not been completed (No), and the process returns to step S20 to continue the welding work. On the other hand, if welding of a predetermined layer has been completed, it is determined that welding of N layers has been completed (Yes), and the process returns to step S18 to measure the temperature of the support leg 100, and then the process from step S19 onwards is executed. That is, the control device 13 confirms that the temperature of the support leg 100 is within the welding temperature range after each layer of welding is completed and then executes the welding work.

[0059] If, in step S21, it is determined (Yes) that welding of all layers in welding lines a11, a12, and a13 has been completed, then in step S23, it is determined whether welding of all layers in the opposing welding sections A1 and A2 has been completed. If, here, it is determined (No) that welding of all layers in welding sections A1 and A2 has not been completed, then in step S24, the robot is made to wait before moving to the next target welding section. That is, if welding of both welding sections A1 and A2 has not been completed, or if welding of either welding section A1 or A2 has not been completed, the welding robot that has completed welding in the welding section is not moved to the next welding section, but is made to wait in that position.

[0060] On the other hand, if it is determined (Yes) that welding of all layers in welding sections A1 and A2 is complete, in step S15, the control device 13 moves the tips of the first welding robot 11 and the second welding robot 12 to the next target welding sections B1 and B2, respectively. Then, the control device 13 uses the first welding robot 11 and the second welding robot 12 to perform the same welding operation as described above on welding sections B1 and B2. Welding is performed on all welding sections A1, B1, C1, D1, A2, B2, C2, and D2 in this manner.

[0061] [Effects of this embodiment] The welding apparatus according to the first embodiment comprises a first welding robot 11 positioned on one side of the axis of symmetry L in the support leg (workpiece to be welded) 100, a second welding robot 12 positioned on the other side of the axis of symmetry L in the support leg 100, and a control device 13 that controls the first welding robot 11 and the second welding robot 12 to weld the first and second welding lines on both sides of the axis of symmetry L in the support leg 100.

[0062] According to the welding apparatus of the first embodiment, the first welding robot 11 and the second welding robot 12 weld the first and second welding lines on both sides of the support plate 104. Therefore, the occurrence of thermal distortion of the member during welding of the first and second welding lines can be suppressed, and welding accuracy can be improved. In addition, the welding time can be shortened.

[0063] In the welding apparatus according to the second embodiment, the first welding line and the second welding line have a line-symmetric shape with respect to the axis of symmetry L of the support leg 100, and the first welding robot 11 and the second welding robot 12 weld the first welding line and the second welding line which are positioned opposite each other with respect to the axis of symmetry L. This makes it possible to suppress the occurrence of thermal distortion of the member during welding of the first welding line and the second welding line.

[0064] In the welding apparatus according to the third embodiment, the first welding line and the second welding line have a point-symmetric shape with respect to the center position O of the support leg 100, and the first welding robot 11 and the second welding robot 12 weld the first welding line and the second welding line which are located diagonally to the support plate 104. This makes it possible to suppress the occurrence of thermal distortion of the member during welding of the first welding line and the second welding line.

[0065] In the welding apparatus according to the fourth embodiment, the first welding line and the second welding line are of the same length. This makes it possible to suppress the occurrence of thermal distortion of the member during welding of the first and second welding lines.

[0066] In the welding apparatus according to the fifth embodiment, the control device 13 starts welding work by the first welding robot 11 and the second welding robot 12, moves the first welding torch 23 of the first welding robot 11 along the first welding line, and moves the second welding torch 33 of the second welding robot 12 along the second welding line. As a result, the first welding robot 11 and the second welding robot 12 weld at opposing positions on the first and second welding lines, and the occurrence of thermal distortion of the member can be effectively suppressed.

[0067] In the welding apparatus according to the sixth embodiment, the support leg 100 has a plurality of welding sections A1, B1, C1, D1, A2, B2, C2, D2, and the control device 13 controls the first welding robot 11 and the second welding robot 12 to perform welding work in the first welding section A1, B1, C1, D1 on one side of the axis of symmetry L and welding work in the second welding section A2, B2, C2, D2 on the other side. As a result, the first welding robot 11 and the second welding robot 12 perform welding work for each of the plurality of welding sections A1, B1, C1, D1, A2, B2, C2, D2, thereby improving work efficiency.

[0068] In the welding apparatus according to the seventh embodiment, the control device 13 starts welding work for the next welding section once the welding work for both the first welding section A1, B1, C1, D1 and the second welding section A2, B2, C2, D2 is completed. As a result, the first welding robot 11 and the second welding robot 12 perform welding work for each opposing welding section A1, B1, C1, D1, A2, B2, C2, D2, thereby suppressing deviations in the welding position.

[0069] In the welding apparatus according to the eighth embodiment, the control device 13 defines the position of the support leg 100 relative to the respective reference points of the first welding robot 11 and the second welding robot 12 based on the three-dimensional design data of the support leg 100 and the three-dimensional measurement data of the support leg 100 positioned at a predetermined position. This makes it possible to define the positional relationship between the welding robots 11, 12 and the support leg 100 fixed to the positioner 120 with high precision.

[0070] In the welding apparatus according to the ninth embodiment, the control device 13 measures the positions of the bottom plate 101, side plates 102, 103, support plate 104, and ribs 105, 106, 107, 108, 109, 110, which are multiple weld target members forming the first and second weld lines, and corrects the position of the support legs 100, which are defined based on the measurement data of the measured positions. This makes it possible to define the positional relationship between the welding robots 11, 12 and the weld lines of the support legs 100 with high precision, thereby improving welding accuracy.

[0071] The welding apparatus according to the tenth embodiment is provided with a heater (heating device) 124 for heating the support legs 100, and the control device 13 starts welding work by the first welding robot 11 and the second welding robot 12 when the temperature of the support legs 100 reaches a preset welding temperature range. This makes it possible to suppress thermal deformation of the support legs 100 during welding.

[0072] In the welding apparatus according to the eleventh embodiment, a heater 124 and a plurality of backing plates 122 thicker than the heater 124 are arranged on a surface plate 121, and support legs 100 can be placed on the plurality of backing plates 122. This simplifies the structure and allows the support legs 100 to be heated appropriately.

[0073] The welding method according to the twelfth embodiment includes the steps of: positioning a first welding robot 11 on one side of a support leg (workpiece to be welded) 100; positioning a second welding robot 12 on the other side of the support leg 100; and controlling the first welding robot 11 and the second welding robot 12 to weld a first welding line and a second welding line on both sides of the support plate (member to be welded) 104 on the support leg 100. This makes it possible to suppress the occurrence of thermal distortion of the member during welding of the first welding line and the second welding line, thereby improving welding accuracy. In addition, the welding time can be shortened.

[0074] The program according to the 13th embodiment causes a computer operating as a welding apparatus 10 to execute the following steps: positioning a first welding robot 11 on one side of a support leg (workpiece to be welded) 100; positioning a second welding robot 12 on the other side of the support leg 100; and controlling the first welding robot 11 and the second welding robot 12 to weld the first and second welding lines on both sides of the support plate (member to be welded) 104 on the support leg 100. This makes it possible to suppress the occurrence of thermal distortion of the member during welding of the first and second welding lines, thereby improving welding accuracy. In addition, the welding time can be shortened.

[0075] In the above-described embodiment, when obtaining 3D measurement data of the object to be welded, touch probes 24 and 34 attached to the tip of the welding robots 11 and 12 were used, but the configuration is not limited to this. The touch probes 24 and 34 do not necessarily have to be provided on the welding robots 11 and 12. Also, instead of the contact-type touch probes 24 and 34, a non-contact type laser measuring instrument or the like may be used.

[0076] Furthermore, in the embodiments described above, the first welding robot 11 and the second welding robot 12 are robots having articulated arms, but the configuration is not limited to this. Appropriate welding robots can be placed along the first and second welding lines of the member to be welded, according to its shape.

[0077] Furthermore, although the welded object was described as a support leg 100 in the above-described embodiment, the configuration is not limited to this. Any welded object may be used as long as a first weld line and a second weld line exist on both sides of the welded member. In this case, it is preferable that the first weld line and the second weld line are symmetrical with respect to the axis of symmetry L, but they do not have to be symmetrical. [Explanation of Symbols]

[0078] 10 Welding equipment 11. First welding robot 12. Second welding robot 13 Control device 14 Input devices 21 Support stand 22. First articulated arm 23. First welding torch 24. First touch probe 25. First temperature sensor 26. First Robot Control Unit 27 1st display device 31 Support stand 32. Second articulated arm 33. Second welding torch 34. Second touch probe 35. Second temperature sensor 36. Second Robot Control Unit 37 2nd display device 100 Support legs 101 Bottom plate 102,103 Side panels 104 Support plate 105, 106, 107, 108, 109, 110 Ribs 120 Positioner 121 Surface plate 122 Toban 123 Insulation 124 Heater (heating device) A1, B1, C1, D1 First welding section A2, B2, C2, D2 Second welding section a11, a12, a13 Weld lines (First weld line) a21, a22, a23 Weld lines (second weld line) O center position P1,P2,P3,P4,P5,P11,P12,P13,P14,P15,P16,P17,P18,P19,P20,P21,P22,P31,P32,P33,P34,P35,P36 Position

Claims

1. A welding apparatus for an object to be welded, wherein a first member, a second member, and a third member are connected orthogonally, Welding robots and A control device for controlling the welding robot, Equipped with, The control device is First three-dimensional measurement data is calculated, which has a position in a first direction and an inclination in a second direction perpendicular to the first direction. A second three-dimensional measurement data having the position in the second direction of the first member is calculated, A third three-dimensional measurement data is calculated, which has a position in the second member in a third direction perpendicular to the first and second directions and an inclination in the second direction. Based on the three-dimensional design data of the object to be welded, the first three-dimensional measurement data, the second three-dimensional measurement data, and the third three-dimensional measurement data, the three-dimensional coordinates of the object to be welded with respect to a reference point in the welding robot are defined. The welding robot is controlled based on the three-dimensional coordinates of the object to be welded to perform welding. Welding equipment.

2. By moving the touch probe in the first direction and bringing it into contact with the first member, two position coordinates in the first direction are determined at two locations in the second direction on the first member, and the control device calculates the position in the first direction and the inclination in the second direction on the first member. The control device moves the touch probe in the second direction and brings it into contact with the first member to determine the position coordinates of the first member in the second direction, and calculates the position of the first member in the second direction. The touch probe is moved in the third direction and brought into contact with the second member, thereby determining two position coordinates in the third direction on the second member at two locations in the second direction, and the control device calculates the position in the third direction and the inclination in the second direction on the second member. The welding apparatus according to claim 1.

3. The control device is Based on the three-dimensional design data of the object to be welded, the first three-dimensional measurement data, the second three-dimensional measurement data, and the third three-dimensional measurement data, the three-dimensional coordinates of the angle where the first member, the second member, and the third member are connected are calculated. Based on the three-dimensional coordinates of the angle, the three-dimensional coordinates of the center position of the object to be welded are calculated. The three-dimensional coordinates of the object to be welded are calculated with the center position of the object to be welded as the origin. The welding apparatus according to claim 1.

4. The control device moves the tip of the welding robot to the welding area, senses the welding line with a touch probe, calculates the three-dimensional coordinates along the welding line based on the positions and inclinations of the first member, the second member, and the third member in the region along the welding line determined by sensing, and corrects the three-dimensional coordinates of the object to be welded. The welding apparatus according to claim 1.

5. A welding method for an object to be welded, comprising a first member, a second member, and a third member connected together, A step of calculating first three-dimensional measurement data having a position in a first direction and an inclination in a second direction perpendicular to the first direction, A step of calculating second three-dimensional measurement data having the position in the second direction of the first member, A step of calculating a third three-dimensional measurement data having a position in a third direction perpendicular to the first and second directions and an inclination in the second direction in the second member, A step of defining the three-dimensional coordinates of the object to be welded with respect to a reference point in a welding robot based on the three-dimensional design data of the object to be welded, the first three-dimensional measurement data, the second three-dimensional measurement data, and the third three-dimensional measurement data, The steps include: controlling a welding robot based on the three-dimensional coordinates of the object to be welded and performing welding; A welding method.

6. A program for welding a weldable object, which is composed of a first member, a second member, and a third member connected together, A step of calculating first three-dimensional measurement data having a position in a first direction and an inclination in a second direction perpendicular to the first direction, A step of calculating second three-dimensional measurement data having the position in the second direction of the first member, A step of calculating a third three-dimensional measurement data having a position in a third direction perpendicular to the first and second directions and an inclination in the second direction in the second member, A step of defining the three-dimensional coordinates of the object to be welded with respect to a reference point in a welding robot based on the three-dimensional design data of the object to be welded, the first three-dimensional measurement data, the second three-dimensional measurement data, and the third three-dimensional measurement data, The steps include: controlling a welding robot based on the three-dimensional coordinates of the object to be welded and performing welding; A program that causes a computer operating as a welding device to execute.

Images