JP7846964B2 - Welding apparatus and method and program - Google Patents

Description

This disclosure relates to a welding apparatus, method, and program for performing welding using a robot.

When performing automated welding using a welding robot, the object to be welded is fixed in a predetermined position, and the welding position on the object is detected using touch sensing or similar methods. Then, the welding robot is automatically controlled to move the welding torch along the welding position and perform welding. Examples of such welding devices include those described in the following patent document.

Patent No. 3355243 Patent No. 4353857

By the way, when welding is performed along the welding position of the object to be welded, thermal distortion occurs in the object. This thermal distortion causes a shift in the welding position for subsequent welds, leading to a decrease in welding accuracy.

This disclosure aims to solve the aforementioned problems and provide a welding apparatus, method, and program that improve welding accuracy.

To achieve the above objective, the welding apparatus of this disclosure comprises: a first welding robot positioned on one side of the axis of symmetry in the workpiece to be welded; a second welding robot positioned on the other side of the axis of symmetry in the workpiece to be welded; and a control device that controls the first and second welding robots to simultaneously weld the first and second welding lines on both sides of the axis of symmetry.

Furthermore, the welding method of this disclosure includes the steps of: positioning a first welding robot on one side of the axis of symmetry in the object to be welded; positioning a second welding robot on the other side of the axis of symmetry in the object to be welded; and controlling the first and second welding robots to simultaneously weld the first and second welding lines on both sides of the axis of symmetry.

Furthermore, the program of this disclosure causes a computer operating as a welding apparatus to execute the following steps: positioning a first welding robot on one side of the symmetric axis of the workpiece; positioning a second welding robot on the other side of the symmetric axis of the workpiece; and controlling the first and second welding robots to simultaneously weld the first and second welding lines on both sides of the symmetric axis.

The welding apparatus, method, and program described herein can improve welding accuracy.

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

Preferred embodiments of this disclosure will be described in detail below with reference to the drawings. However, this embodiment does not limit the disclosure, and where there are multiple embodiments, they may be combinations of these embodiments. Furthermore, the components in the embodiments include those readily conceivable by those skilled in the art, those that are substantially identical, and those within the so-called equivalent range.

[First Embodiment]
<Support legs>
Figure 11 is a perspective view of the support leg, and Figure 12 is a plan view of the support leg. In the following explanation, the width direction (horizontal direction) of the support leg will be referred to as the X direction, the longitudinal direction (horizontal direction) of the support leg as the Y direction, and the vertical direction of the support leg as the Z direction.

In this embodiment, the object to be welded in Figures 11 and 12 is the support leg 100. The support leg 100 is, for example, used to support a large structure. The support leg 100 consists of one base plate 101, two side plates 102 and 103, one support plate 104, and six ribs 105, 106, 107, 108, 109, and 110.

The base plate 101 has a plate shape that aligns with the X and Y directions, with its length in the Y direction being longer than its length in the X direction. The lower parts of the side plates 102 and 103 are connected to each end of the base plate 101 in the Y direction. The side plates 102 and 103 have a plate shape that aligns with the X and Z directions, with their length in the Z direction being longer than their length in the X direction. A support plate 104 is connected to the inside of the base plate 101 and the side plates 102 and 103. The support plate 104 has a plate shape that aligns with the Y and Z directions, with its length in the Y direction being longer than its length in the Z direction. The lower part of the support plate 104 is connected to the base plate 101, and each side is connected to the side plates 102 and 103, respectively. The support plate 104 is positioned at an intermediate position in the X direction relative to the base plate 101 and the side plates 102 and 103. Furthermore, the support plate 104 has a curved shape such that its upper part is concave downwards in the Z direction.

The base plate 101 and the support plate 104 are connected by ribs 105, 106, 107, 108, 109, and 110. Ribs 105, 106, 107, 108, 109, and 110 have a plate shape that aligns with the X and Z directions. Ribs 105, 106, 107, 108, 109, and 110 are connected perpendicularly to the base plate 101 and the support plate 104. Ribs 105, 106, 107, and 108 have the same shape, and ribs 109 and 110 also have the same shape. Ribs 105, 106, 107, 108, 109, and 110 have the same length in the X direction, while the Z-direction length of ribs 105, 106, 107, and 108 is longer than the Z-direction length of ribs 109 and 110.

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.

<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.

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 surface plate 121 and the lower surface of the base plate 101 of the support leg 100.

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. Note that 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. Furthermore, 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.

The support legs 100 are placed on multiple backing plates 122 arranged on the base plate 121. The support legs 100 are positioned so that their centers align with the center of the positioner 120. The support legs 100, positioned at a predetermined location on the positioner 120, have their base plates 101 fixed to the backing plates 122, for example, by welding. At this time, the underside of the base plate 101 of the support legs 100 faces multiple heaters 124. Therefore, the support legs 100 can be heated via the base plate 101 by the multiple heaters 124. 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 low-temperature cracking and deformation during welding.

<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.

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

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

The support legs 100 are supported by the positioner 120. The first welding robot 11 is positioned on one side of the support legs 100 in the X direction. The second welding robot 12 is positioned on the other side of the support legs 100 in the X direction. That is, the first welding robot 11 and the second welding robot 12 face each other across the support legs 100, which are supported by the positioner 120. The first welding robot 11 is positioned on the support base 21 and is supported so as to be movable along the Y direction. The second welding robot 12 is positioned on the 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.

The first welding robot 11 has a first articulated arm 22, with a first welding torch 23 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, with a second welding torch 33 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.

The first welding robot 11 is connected to the first robot control unit 26. The first robot control unit 26 controls the welding operation 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 operation performed by the second welding robot 12 based on a preset program. Furthermore, the first robot control unit 26 is connected to the first display device 27, and the second robot control unit 36 is 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 operation 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 display images of the welding operation (such as the welding bead) captured by a CCD camera located at the tip of a multi-joint arm 22 or 32 (not shown). The first display device 27 and the second display device 37 also display information such as the remaining amount of welding wire and the timing for replacing the welding tip.

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. The control device 13 is connected to an input device 14. The input device 14 is connected to various databases, allowing the operator to input various data stored in the databases into the control device 13 using the input device 14. Furthermore, 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.

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.

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

Furthermore, the first welding robot 11 and the second welding robot 12 may simultaneously weld the first and second welding lines located diagonally opposite each other with respect to the support plate 104. That is, the first welding robot 11 welds the support leg 100 in the order of welding sections A1, B1, C1, and D1. The second welding robot 12 welds the support leg 100 in the order of welding sections B2, A2, D2, and C2. While the first welding robot 11 is welding welding section A1 of the support leg 100, the second welding robot 12 welds 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: welding sections B1, A2, welding sections C1, D2, and welding sections D1, C2.

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. Welding line a11 is formed by moving the first welding torch 23 (see Figure 1) in a U-shape along the horizontal direction (X and Y directions) and welding the bottom plate 101 to the ribs 105 and 109, and the bottom plate 101 to the support plate 104, respectively. Welding line a12 is formed by moving the first welding torch 23 along the vertical direction (Z direction) and welding 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 second welding robot 12, which performs welding in welding area A2, operates similarly, and welding lines a21, a22, and a23 are set as second welding lines.

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.

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. That is, 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 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.

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.

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 support leg arrangement 100 is not limited to using the touch probes 24 or 34; for example, a wire touch sensor that detects the wire emanating from the welding torches 23 or 33 by applying current 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.

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 measurement data of the support legs 100's position. 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.

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.

<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.

The following explanation describes the case where 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. However, the same principle applies when the first welding robot 11 and the second welding robot 12 simultaneously weld the first and second welding lines that are positioned diagonally to the support plate 104.

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 aligns with 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, into 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, as controlled by the control device 13.

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.

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 stopped 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.

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 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 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-direction position and X-direction inclination on the base plate 101 are calculated.

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.

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.

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. Finally, 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.

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 moves to welding area A1, and the tip of the second welding robot 12 moves 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.

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, and P20 on the base plate 101 in the region along the weld line a11.

Furthermore, 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 position in the X direction on the rib 105 is calculated based on the X-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 position in the X direction on the rib 109 is calculated based on the X-coordinate of position P22.

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. Additionally, the Z-coordinate of the upper surface position P36 near the corner of the welding section A1 on the base plate 101 is determined using the first touch probe 24. In this way, the Y-direction position and inclination of the rib 105 are calculated based on the Y-direction position coordinates of the rib 105 positions P31, P32, and P33 in the region along the welding line a12, and the X-direction position and inclination of the support plate 104 are calculated based on the X-direction position coordinates of the support plate 104 positions P34 and P35.

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.

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.

Furthermore, the control device 13 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.

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.

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. Then, the first welding robot 11 performs welding in the order of welding lines a11, a12, and a13, and the second welding robot 12 performs welding in the order of welding lines a21, a22, and a23. The first welding robot 11 and the second welding robot 12 operate synchronously, simultaneously welding the first and second welding lines of welding sections A1 and A2, which are positioned on either side of the support plate 104.

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. That is, 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". Also, 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 on the 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 of layers.

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 along welding line a11. After welding 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. This method allows for the detection of thermal deformation of the support leg 100 due to welding line a11 during sensing along welding lines a12 and a13, enabling high-precision welding of welding lines a12 and a13.

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 is not complete (No), then in step S22, it determines whether welding of the N layers has been completed. That is, if welding of a predetermined layer is still in progress, it is determined that welding of the N layers is not complete (No), and the process returns to step S20 to continue the welding operation. On the other hand, if welding of the predetermined layer is complete, it is determined that welding of the N layers is complete (Yes), and the process returns to step S18 to measure the temperature of the support leg 100, and then executes the processes from step S19 onwards. In other words, the control device 13 confirms that the temperature of the support leg 100 is within the welding temperature range after each layer is welded and then executes the welding operation.

In step S21, if it is determined (Yes) that welding of all layers in welding lines a11, a12, and a13 is complete, then in step S23, it is determined whether welding of all layers in the opposing welding sections A1 and A2 is complete. If it is determined (No) that welding of all layers in welding sections A1 and A2 is not complete, 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 is not complete, or if welding of either welding section A1 or A2 is not complete, the welding robot that has completed welding the section is not moved to the next welding section, but remains in that position.

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 on welding sections B1 and B2 as described above. Welding is then performed on all welding sections A1, B1, C1, D1, A2, B2, C2, and D2.

[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.

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, improving welding accuracy. Furthermore, the welding time can be shortened.

In the welding apparatus according to the second embodiment, the first and second welding lines have a line-symmetrical 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 and second welding lines, 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 and second welding lines.

In the welding apparatus according to the third embodiment, the first and second welding lines have a point-symmetrical 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 and second welding lines, 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 and second welding lines.

In the welding apparatus according to the fourth embodiment, the first and second welding lines are of the same length. This suppresses the occurrence of thermal distortion in the member during welding of the first and second welding lines.

In the fifth embodiment of the welding apparatus, the control device 13 initiates welding operations by the first welding robot 11 and the second welding robot 12. The first welding torch 23 of the first welding robot 11 moves along the first welding line, while the second welding torch 33 of the second welding robot 12 moves along the second welding line. As a result, the first welding robot 11 and the second welding robot 12 weld at opposing positions along the first and second welding lines, effectively suppressing thermal distortion of the material.

The welding apparatus according to the sixth embodiment has a support leg 100 with multiple welding sections A1, B1, C1, D1, A2, B2, C2, and D2. The control device 13 controls the first welding robot 11 and the second welding robot 12 to perform welding operations in the first welding sections A1, B1, C1, and D1 on one side of the symmetry axis L, and in the second welding sections A2, B2, C2, and D2 on the other side. This allows the first welding robot 11 and the second welding robot 12 to perform welding operations in each of the multiple welding sections A1, B1, C1, D1, A2, B2, C2, and D2, thereby improving work efficiency.

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. This ensures that 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.

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 location. This allows for highly accurate definition of the positional relationship between the welding robots 11 and 12 and the support leg 100 fixed to the positioner 120.

In the ninth embodiment of the welding apparatus, 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, and 110, which are multiple welding target members forming the first and second welding lines. Based on the measurement data of the measured positions, the control device corrects the defined position of the support legs 100. This allows for highly accurate definition of the positional relationship between the welding robots 11, 12 and the welding lines of the support legs 100, thereby improving welding accuracy.

The welding apparatus according to the tenth embodiment is equipped with a heater (heating device) 124 for heating the support legs 100. The control device 13 initiates welding operations 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 suppresses thermal deformation of the support legs 100 during welding.

The welding apparatus according to the eleventh embodiment has a heater 124 and a plurality of backing plates 122 thicker than the heater 124 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.

The welding method according to the twelfth embodiment includes the steps of: positioning a first welding robot 11 on one side of the 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 (workpiece to be welded) 104 on the support leg 100. This suppresses the occurrence of thermal distortion of the member during welding of the first and second welding lines, thereby improving welding accuracy. Furthermore, it allows for a reduction in welding time.

The program according to the 13th embodiment involves causing a computer operating as a welding apparatus 10 to execute the following steps: positioning a first welding robot 11 on one side of the 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 (workpiece to be welded) 104 on the support leg 100. This suppresses the occurrence of thermal distortion of the workpiece during welding of the first and second welding lines, thereby improving welding accuracy. Furthermore, it shortens the welding time.

In the above-described embodiment, touch probes 24 and 34 attached to the tips of welding robots 11 and 12 were used to obtain three-dimensional measurement data of the object to be welded. However, 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. Furthermore, non-contact type laser measuring instruments or the like may be used instead of the contact-type touch probes 24 and 34.

Furthermore, in the embodiment described above, the first welding robot 11 and the second welding robot 12 were 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, depending on its shape.

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

10 Welding apparatus 11 First welding robot 12 Second welding robot 13 Control device 14 Input device 21 Support base 22 First articulated arm 23 First welding torch 24 First touch probe 25 First temperature sensor 26 First robot control unit 27 First display device 31 Support base 32 Second articulated arm 33 Second welding torch 34 Second touch probe 35 Second temperature sensor 36 Second robot control unit 37 Second display device 100 Support legs 101 Bottom plate 102, 103 Side plate 104 Support plate 105, 106, 107, 108, 109, 110 Rib 120 Positioner 121 Surface plate 122 Backing plate 123 Insulation material 124 Heater (heating device)
A1, B1, C1, D1: First welding area; A2, B2, C2, D2: Second welding area; a11, a12, a13: Weld line (first welding 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 (12)

A welding apparatus for a workpiece having multiple welding sections, wherein the end of a second member is connected to the flat portion of a first member, and the ends of a plurality of third members are connected to the flat portions of the first member and the flat portions of the second member at intervals in the longitudinal direction of the first member, the apparatus being configured such that the apparatus has multiple welding sections .
A first welding robot is positioned on one side of the axis of symmetry along the second member,
A second welding robot is positioned on the other side of the axis of symmetry,
A control device for controlling the first and second welding robots, such that the first welding robot welds a first weld line forming a U shape in a first welding section along the connection between the first, second, and third members on one side of the axis of symmetry, and the second welding robot welds a second weld line forming a U shape in a second welding section along the connection between the first , second, and third members on the other side of the axis of symmetry.
A welding apparatus equipped with the following features. The first weld line and the second weld line have a line-symmetric shape with respect to the axis of symmetry, and the first welding robot and the second welding robot weld the first weld line and the second weld line which are positioned opposite each other with respect to the axis of symmetry.
The welding apparatus according to claim 1. The first weld line and the second weld line are point-symmetrical with respect to the center position of the object to be welded, and the first welding robot and the second welding robot weld the first weld line and the second weld line which are located diagonally opposite each other with respect to the center position of the object to be welded.
The welding apparatus according to claim 1. The first weld line and the second weld line are of the same length.
A welding apparatus according to any one of claims 1 to 3. The control device starts welding operations by the first welding robot and the second welding robot, moves the first welding torch of the first welding robot along the first welding line, and moves the second welding torch of the second welding robot along the second welding line.
A welding apparatus according to any one of claims 1 to 4. The control device, once both the welding work in the first welding area and the welding work in the second welding area are completed, starts the welding work in the next welding area.
The welding apparatus according to claim 1 . The control device defines the position of the object to be welded relative to the respective reference points of the first welding robot and the second welding robot based on the three-dimensional design data of the object to be welded and the three-dimensional measurement data of the object to be welded positioned at a predetermined location.
A welding apparatus according to any one of claims 1 to 6 . The control device measures the positions of a plurality of welding targets that form the first and second welding lines, and corrects the position of the welding target defined based on the measured data of the positions of the welding targets.
The welding apparatus according to claim 7 . A heating device is provided for heating the object to be welded, and the control device starts welding operations by the first welding robot and the second welding robot when the temperature of the object to be welded reaches a preset welding temperature range.
A welding apparatus according to any one of claims 1 to 8 . The heating device and a plurality of backing plates thicker than the heating device are arranged on a surface plate, and the object to be welded can be placed on the plurality of backing plates.
The welding apparatus according to claim 9 . A welding method for an object to be welded having multiple weld sections, wherein the end of a second member is connected to the flat portion of a first member, and the ends of a plurality of third members are connected to the flat portions of the first member and the flat portions of the second member at intervals in the longitudinal direction of the first member, the welding method comprising:
The steps include: positioning the first welding robot on one side of the axis of symmetry along the second member;
The steps include: positioning a second welding robot on the other side of the aforementioned axis of symmetry;
A process of controlling the first welding robot and the second welding robot so that the first welding robot welds a first weld line forming a U shape in a first welding section along the connection portion between the first member, the second member and the third member on one side of the axis of symmetry, and the second welding robot welds a second weld line forming a U shape in a second welding section along the connection portion between the first member, the second member and the third member on the other side of the axis of symmetry,
A welding method. A program for welding an object to be welded having multiple welding sections, wherein the end of a second member is connected to the flat portion of a first member, and the ends of a plurality of third members are connected to the flat portions of the first member and the flat portions of the second member at intervals in the longitudinal direction of the first member, the program comprising:
The steps include: positioning the first welding robot on one side of the axis of symmetry along the second member;
The steps include: positioning a second welding robot on the other side of the aforementioned axis of symmetry;
A process of controlling the first welding robot and the second welding robot so that the first welding robot welds a first weld line forming a U shape in a first welding section along the connection portion between the first member, the second member and the third member on one side of the axis of symmetry, and the second welding robot welds a second weld line forming a U shape in a second welding section along the connection portion between the first member, the second member and the third member on the other side of the axis of symmetry,
A program that causes a computer operating as a welding device to execute.