Welding torch target position setting method, weaving method, and welding system

Abstract

To provide a welding torch target position setting method which can set a target position of a welding torch without being affected by a curl of a welding wire and can improve working efficiency and welding quality, and to provide a weaving method and a welding system.SOLUTION: In a welding torch target position setting method of a portable welding robot which moves along a guide rail attached to a workpiece having a bevel to weld the workpiece, the portable welding robot includes: a welding torch; and a moving mechanism which moves the welding torch in an extension direction, a width direction, and a depth direction of the bevel. The method includes: a shape information acquisition step of calculating shape information of the bevel; a relative position acquisition step of acquiring relative position relation data; a lamination design step; and a target position setting step of moving a tip of a welding wire of the welding torch to a welding torch target position.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a welding torch target position setting method, a weaving method, and a welding system. [Background technology]

[0002] In the manufacturing of welded structures in shipbuilding, steel frames, bridges, etc., welding work in factories places emphasis on work efficiency, and systems that apply large, stationary multi-axis welding robots are often used, mainly for flat position welding. A system that applies a stationary multi-axis welding robot is, for example, a welding robot system in which the workpiece (hereinafter referred to as the "work") is placed in a stationary positioner and automatically welded using a multi-axis welding robot. On the other hand, for on-site welding where large multi-axis welding robots cannot be used, or for welding small components or components with complex shapes, manual welding such as semi-automatic welding, or automatic welding using lightweight and small portable welding robots that can be carried by a single worker, are widely used. Portable welding robots in particular are being increasingly used for on-site welding, taking advantage of their portability.

[0003] In such a portable welding robot, from the viewpoint of preventing defects such as insufficient fusion and insufficient penetration of the welded portion, Patent Document 1 shows a welding torch angle adjuster that can adjust the angle of the welding torch around the wire target position of the welding torch. According to Patent Document 1, the welding torch angle adjuster has a guide member having an arc-shaped groove of a certain curvature centered on the wire target position of the welding torch, a slide member that moves along the arc-shaped groove of the guide member, a means for fixing the slide member to an arbitrary position of the arc-shaped groove, and a welding torch holder connected to the slide member. Furthermore, according to Patent Document 1, when welding a portion close to the groove wall surface, the welding torch angle adjuster can adjust the welding torch angle so that penetration can be easily obtained without changing the welding target position and without the welding torch interfering with the groove wall surface.

[0004] In Patent Document 2, a guide member having an arc-shaped groove of a certain curvature centered on the wire target position of the welding torch is fitted with an arc-shaped rack of the same curvature, and a pinion that meshes with the arc-shaped rack is fitted to a slide member. The pinion moves along the arc-shaped rack by its rotation, and the welding torch holder moves along the guide, making it possible to precisely adjust the welding torch angle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-328831 [Patent Document 2] Japanese Patent Application Publication No. 8-276267 Summary of the Invention [Problem to be solved by the invention]

[0006] According to Patent Documents 1 and 2, the angle of the welding torch is adjusted by moving the welding torch holder along a guide member having an arc-shaped groove with a certain curvature centered on the wire target position of the welding torch. However, in reality, the welding wire at the tip of the welding torch is bent due to a bending tendency, and the tip of the welding wire is positioned at a position that is different from the expected wire target position of the welding torch. In this state, even if the angle of the welding torch is adjusted centered on the wire target position of the welding torch, the actual tip of the welding wire will move, and the wire target position will be shifted.

[0007] In addition, the bending tendency of the welding wire changes depending on the storage state of the welding wire and the feeding path from the welding wire feeder to the welding torch, and the bending tendency is arbitrary, so it is difficult to predict the bending state of the welding wire in advance and determine the center of rotation. In other words, Patent Documents 1 and 2 make no mention of the bending tendency of the welding wire, and do not allow the angle of the welding torch to be adjusted around the actual tip position of the welding wire. In order to adjust the angle of the welding torch with the tip of the welding wire as the target position, it is necessary to take the bending tendency of the welding wire into consideration.

[0008] Generally, welding wire is stored in a cylindrical frame or container, as in the case of spool wire or packed wire, and before being fed to a welding torch, bending caused by storage is corrected by a device called a straightener, but it is difficult to completely correct the bending. In addition, from the viewpoint of ensuring stable power supply between the welding tip and the welding wire, a certain degree of bending is required to stabilize power supply, so the welding wire coming out of the welding torch always has a bending tendency. The bending amount of the welding wire changes arbitrarily every time welding is performed or every time the feeding path of the welding wire from the feeding device to the welding torch is changed, so it is difficult to predict the bending state of the welding wire in advance and adjust the angle of the welding torch.

[0009] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a welding torch target position setting method, a weaving method, and a welding system that can set the target position of a welding torch without being affected by the bending tendency of a welding wire, thereby improving work efficiency and welding quality. [Means for solving the problem]

[0010] The above object of the present invention can be achieved by the following configuration. (1) A method for setting a welding torch target position of a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, comprising the steps of: The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; Equipped with A shape information acquisition process of touch-sensing the groove using the welding torch and calculating shape information of the groove; A relative position acquisition process for acquiring relative positional relationship data between a tip of the welding wire having a bending tendency and a shape of the groove; A lamination design process for performing a lamination design based on the shape information of the groove; a target position setting process of moving a tip of the welding wire of the welding torch to a welding torch target position of the welding pass designed based on the correlation positional relationship data; Equipped with How to set the welding torch aim position. (2) A weaving method for a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, comprising: The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; a torch angle adjustment mechanism that changes an angle of the welding torch by rotating the welding torch around a tip of a welding wire that is imaginary on a straight extension line of the welding torch within a plane perpendicular to an extension direction of the groove; Equipped with a displacement amount acquisition process for performing touch sensing of the groove using the welding torch having a first torch angle and a second torch angle different from the first torch angle, which are changed by the torch angle adjustment mechanism before welding, to calculate shape information of the groove, and acquiring correlation positional relationship data between the tip of the welding wire having a bending habit and the shape of the groove, and a displacement amount of the tip of the welding wire in the width direction of the groove and the depth direction of the groove at the first torch angle and the second torch angle; a torch angle adjustment process in which the welding torch is changed to a desired torch angle by the torch angle adjustment mechanism when welding while weaving the welding torch in the width direction of the groove; a deviation amount correction process of correcting the deviation amount at the desired torch angle, the deviation amount being calculated from the deviation amounts at the first torch angle and the second torch angle, by the movement mechanism; Equipped Weaving methods. (3) A welding system having a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, and a control device that controls an operation of the portable welding robot, The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; Equipped with The control device includes: Using the welding torch, touch sensing is performed on the groove to calculate shape information of the groove, and correlation position relationship data between the tip of the welding wire having a bending tendency and the shape of the groove is obtained; Based on the shape information of the groove, a layering design is performed. moving a tip of the welding wire of the welding torch to a welding torch target position of the welding pass designed according to the layered design based on the correlated positional relationship data; Welding system. Effect of the Invention

[0011] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a method for setting an aim position of a welding torch for a portable welding robot, a method for correcting the aim position of a portable welding robot, a weaving method for a portable welding robot, and a welding system, which are capable of setting the aim position of a welding torch without being affected by the bending tendency of a welding wire, and thereby improving work efficiency and welding quality. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a welding system according to this embodiment. [Figure 2A] FIG. 2A is a diagram showing a portable welding robot with a welding torch tilted. [Figure 2B] FIG. 2B is a diagram showing the portable welding robot with the welding torch in an upright position. [Diagram 3] FIG. 3 is a diagram showing the torch approximate linear movement mechanism. [Figure 4] FIG. 4 is a diagram showing the tip of a welding torch when a welding wire having a bent tendency is used. [Diagram 5] FIG. 5 is a diagram illustrating a procedure for acquiring groove shape information by a touch sensor. [Figure 6] FIG. 6 is a diagram illustrating the correlation position acquisition process. [Figure 7] FIG. 7 is a diagram showing a layered design for forming a welded joint in a groove. [Figure 8] FIG. 8 is a schematic diagram showing a state in which the torch angle of a welding torch using a welding wire with a bent tendency is adjusted. [Figure 9] FIG. 9 is a schematic diagram showing a method for correcting the target position of the welding torch when the torch angle is adjusted using a welding wire that has a bent tendency. [Figure 10] FIG. 10 is a diagram showing groove shape data for the first torch angle θ1 and groove shape data for the second torch angle θ2. [Figure 11] FIG. 11 is a schematic diagram showing a weaving method involving a change in torch angle. [Figure 12] FIG. 12 is a diagram showing a portable welding robot equipped with a torch angle adjustment mechanism according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the configuration of a welding system to which the present invention is applied will be described with reference to the accompanying drawings. Note that each drawing is created for the purpose of explaining the present invention, and the embodiment of the present invention is not limited to the contents of the drawings.

[0014] <Welding system configuration> Fig. 1 is a schematic diagram showing the configuration of a welding system according to this embodiment. As shown in Fig. 1, welding system 50 includes portable welding robot 100 (hereinafter referred to as "welding robot"), feeder 300, welding power source 400, shielding gas supply source 500, and controller 600.

[0015] (Control device 600) Control device 600 is connected to welding robot 100 via robot control cable 610, and to welding power source 400 via power source control cable 620. Control device 600 has a data storage unit 601 that stores teaching data that defines in advance the motion pattern, welding start position, welding end position, welding conditions, weaving motion, etc. of welding robot 100, and sends commands to welding robot 100 and welding power source 400 based on this teaching data to control the motion of welding robot 100 and the welding conditions.

[0016] The control device 600 has a groove shape information calculation unit 602 that calculates groove shape information from detection data obtained by touch sensing, which will be described later, and a welding condition acquisition unit 603 that corrects and acquires the welding conditions of the teaching data based on the groove shape information. The groove shape information calculation unit 602 and the welding condition acquisition unit 603 constitute a control unit 604. The control unit 604 is configured to be capable of executing target position setting control for setting the tip 220' of the welding wire 211', which has a tendency to bend, to a predetermined target position.

[0017] (Welding power source 400) In response to a command from control device 600, welding power source 400 supplies power to consumable electrode (hereinafter also referred to as "welding wire") 211 and workpiece W, thereby generating an arc between welding wire 211 and workpiece W. Power from welding power source 400 is sent to wire feeder 300 via power cable 410, and is sent from wire feeder 300 to welding torch 200 via conduit tube 420.

[0018] (Shielding gas source 500) The shielding gas supply source 500 is composed of a container filled with shielding gas and auxiliary members such as a valve. The shielding gas is sent from the shielding gas supply source 500 to the feeder 300 via a gas tube 510. The shielding gas sent to the feeder 300 is sent to the welding torch 200 via a conduit tube 420. The shielding gas sent to the welding torch 200 flows inside the welding torch 200, is guided by the nozzle 210, and is ejected from the tip side of the welding torch 200. For example, argon (Ar), carbon dioxide (CO2), or a mixture of these gases is used as the shielding gas.

[0019] (Feeding device 300) The feeder 300 pays out the welding wire 211 and feeds it to the welding torch 200. The welding wire 211 fed by the feeder 300 is not particularly limited and is selected depending on the properties of the workpiece W, the welding form, etc., and for example, a solid wire or a flux-cored wire (hereinafter also referred to as "FCW") is used. The material of the welding wire 211 is also not limited, and may be, for example, mild steel, stainless steel, aluminum, titanium, or other materials. Furthermore, the wire diameter of the welding wire 211 is also not limited. In this embodiment, it is preferable to use an FCW from the viewpoint of welding workability, and a basic FCW is even more preferable. Furthermore, when a basic FCW is used, it is preferable to use a positive polarity.

[0020] (Welding Robot 100) Fig. 2A is a diagram showing a welding robot with a tilted welding torch, Fig. 2B is a diagram showing a welding robot with a standing welding torch, and Fig. 3 is a diagram showing a torch approximate linear movement mechanism. The welding robot 100 includes a robot body 110 , a guide rail 120 , a torch connection portion 130 , a torch angle adjustment mechanism 140 , and a torch approximate linear movement mechanism 150 . The robot body 110 moves along a guide rail 120 extending along a groove 10 formed in a workpiece W to be welded. A torch connection part 130 to which a welding torch 200 is attached is supported on the robot body 110 via a torch angle adjustment mechanism 140 and a torch approximate linear movement mechanism 150 so that the posture of the torch connection part 130 can be changed. In the example shown in this embodiment, the groove 10 is formed in a trapezoidal shape by groove walls 11, 12 which are inclined left and right surfaces, and a root portion 13 which is a bottom surface formed between the groove walls 11, 12. This configuration may be seen in Figs. 2A to 3.

[0021] The welding robot 100 also has a detection means for detecting the shape of the groove to be welded. The welding robot 100 uses a touch sensor as the detection means, which applies a voltage between the workpiece W and the welding wire 211 and uses a voltage drop phenomenon that occurs when the welding wire 211 comes into contact with the workpiece W to touch-sense the surface of the groove 10, etc.

[0022] The robot body 110 has a movement mechanism that is capable of moving the welding torch 200 in three orthogonal axes, and includes an X-axis movement mechanism, a Y-axis movement mechanism, and a Z-axis movement mechanism. The X-axis movement mechanism moves the robot body 110 along a guide rail 120 that extends in the X-axis direction, which is perpendicular to the paper and corresponds to the weld line direction, as indicated by an arrow X in FIG. 2A. The Y-axis movement mechanism slides a movable body 112 provided on the robot body 110 in the Y-axis direction, which is perpendicular to the X-axis direction and the Z-axis direction and also the width direction of the groove 10, as indicated by the arrow Y in Figure 2A. The Z-axis movement mechanism moves the robot body 110 in an expanding and contracting manner in the Z-axis direction, which is the depth direction of the groove 10 perpendicular to the X-axis direction and the Y-axis direction, as indicated by the arrow Z in FIG. 2A. The movement mechanism may be configured to move the welding torch 200 in the extension direction of the groove, the width direction of the groove, and the depth direction of the groove.

[0023] The torch connection portion 130 includes torch clamps 132, 134 that secure the welding torch 200. Torch connection part 130 is configured so that a torch angle θ of the tip of welding torch 200 can be adjusted by a torch angle adjustment mechanism 140 provided on robot body 110. Torch angle θ is an angle centered on tip 220 of welding wire 211, which is imaginary on a straight extension line of welding torch 200, and is an angle at which welding torch 200 is inclined in the groove width direction. Torch connection part 130 is configured so that torch angle φ of the tip of welding torch 200 can be adjusted by torch approximate linear movement mechanism 150 provided in torch angle adjustment mechanism 140, without changing the height position of welding torch 200. Torch angle φ is an angle centered on tip 220 of welding wire 211, which is supported movably in the extension direction (X-axis direction) of groove 10 and is an angle at which welding torch 200 is inclined with respect to the weld line direction.

[0024] The torch angle adjustment mechanism 140 has a slide support portion 141 , a fixed arm portion 142 , a movable arm portion 143 , and a drive motor 144 . The slide support portion 141 is a support member attached and fixed to the movable body 112 that slides in the Y-axis direction. The fixed arm portion 142 is attached and fixed to the slide support portion 141. The movable arm portion 143 is supported so as to be rotatable along a predetermined movement trajectory relative to the fixed arm portion 142 by the driving force of a drive motor 144. This configuration may be seen in Figures 2A and 2B.

[0025] Fixed arm portion 142 is a support plate that extends on the YZ plane and is fixed to slide support portion 141, and has an arc-shaped guide groove 142a formed therein. Driving motor 144 is attached and fixed to the upper end of fixed arm portion 142. The axis position of arc-shaped guide groove 142a is configured to be the position of tip 220 of welding wire 211 that has no bending tendency, which is imaginary on a straight extension line of welding torch 200. This configuration may be seen in FIG. 2A.

[0026] The movable arm portion 143 is a rotating plate that extends on the YZ plane and rotates along the fixed arm portion 142. The movable arm portion 143 is provided with a guide body 147 that is inserted into the guide groove 142a, and a circular arc rack portion 148 that is attached and fixed to the upper end side of the movable arm portion 143. The movable arm portion 143, the guide body 147, and the plate-shaped fixed arm portion 142 are arranged to sandwich them. The arcuate rack portion 148 is formed with the same curvature as the guide groove 142a, and has an arcuate meshing portion 148a that meshes with a pinion gear 144a provided on the output shaft of the drive motor 144.

[0027] According to this configuration, in the torch angle adjustment mechanism 140, a signal is sent from the control device 600 to the drive motor 144, and this command signal causes the rotating shaft of the drive motor 144 to rotate, thereby causing the movable arm portion 143 to rotate along the guide groove 142a via the arc rack portion 148. This makes it possible to arbitrarily adjust the torch angle θ of the welding torch 200 supported by the torch connecting part 130. This configuration can be seen in Figures 2A and 2B.

[0028] The above-described torch angle adjustment mechanism 140 may be a torch angle adjustment mechanism 170 that can manually adjust the torch angle θ of the welding torch 200, as shown in Fig. 12. Fig. 12 is a diagram showing a welding robot equipped with a torch angle adjustment mechanism of another embodiment. As shown in FIG. 12, the torch angle adjustment mechanism 170 has a slide support portion 171, a fixed arm portion 172, and a movable arm portion 173. The slide support portion 171 is a support member attached and fixed to the movable body 112 that slides in the Y-axis direction, and is supported so as to be capable of sliding also in the Z-axis direction. The fixed arm portion 172 is a plate-like member that is attached and fixed to the slide support portion 171, and is formed with an arc-shaped guide groove 172a. The movable arm portion 173 is a rotating plate that swings along the guide groove 172a of the fixed arm portion 172. The movable arm portion 173 has a guide body 174 that is inserted into the guide groove 172a and is manually fastened to restrict the movement along the guide groove 172a, and a support portion 175 that is supported on the fixed arm portion 172 side so as to be swingable. This configuration may be seen in FIG. 12.

[0029] Torch approximate linear movement mechanism 150 has a sliding table 151 to which torch connecting part 130 is attached, a welding torch rotation drive part 153 attached to the movable arm part 143 side of torch angle adjustment mechanism 140, and a crank 152 connecting between sliding table 151 and welding torch rotation drive part 153. This configuration may be seen in FIG. 3.

[0030] Sliding table 151 is a plate-like member extending along welding torch 200, and has a long groove 151a formed in the middle part along the longitudinal direction. A fixed pin 156 fixed to welding torch rotation drive part 153 is slidably fitted into long groove 151a. The welding torch rotation drive unit 153 has a drive motor (not shown), and a rotary shaft 154 of the drive motor is connected to one end of the crank 152 . One end of the crank 152 is connected to a rotating shaft 154 , and the other end is connected to the upper end of the sliding table 151 via a connecting pin 155 .

[0031] According to this configuration, when the crank 152 rotates about the rotating shaft 154 by a drive motor (not shown), the sliding table 151 rotates about the fixed pin 156 as a fulcrum and moves along the long groove 151a, guided by the fitted fixed pin 156. That is, the torch connection part 130 to which the welding torch 200 is attached drives the tip of the welding wire 211 along the approximate straight line shown by the imaginary line IL in Fig. 3 with respect to the X-axis direction while tilting the welding torch 200 by rotating the crank 152 as shown by the arrow R2 in Fig. 3. In other words, the torch angle φ of the welding torch 200 supported by the torch connection part 130 can be arbitrarily adjusted without changing the height position of the tip of the welding wire. This configuration may be seen in Fig. 3.

[0032] As described above, the welding torch 200 can move in the X-axis direction, which is the extension direction of the groove 10, by the robot body 110 moving along the guide rail 120. In addition, the welding torch 200 can move in the Y-axis direction, which is the width direction of the groove 10, and in the Z-axis direction, which is the depth direction of the groove 10, by controlling the position of the torch connection part 130 supported by the robot body 110. In addition, welding torch 200 can be rotated by torch angle adjustment mechanism 140 along the YZ plane perpendicular to the weld line, centered on tip 220 of welding wire 211, which is an imaginary straight line extension of welding torch 200. In addition, the welding torch 200 can be rotated by the torch approximate linear movement mechanism 150 along the XZ plane along the weld line depending on the construction situation, such as setting a forward angle or a backward angle, thereby adjusting the torch angle φ of the welding torch 200.

[0033] Next, a state in which the welding wire is actually inserted into the welding torch will be described with reference to Fig. 4. Fig. 4 is a diagram showing the tip of the welding torch when a welding wire having a bent tendency is used. As shown in FIG. 4, tip 220' of welding wire 211' having an actual bent tendency is located away from tip 220 of welding wire 211 assumed to be a straight extension of welding torch 200, resulting in a deviation from the intended target. Since the welding arc is directed directionally from the tip 220 of the welding wire 211 toward the base metal, the position of the base metal where actual penetration is obtained will deviate from the hypothetical base metal position on an extension of the tip 220 of the welding wire, which may induce defects such as insufficient fusion and insufficient penetration, thereby affecting the welding quality. Hereinafter, a method for setting the welding torch target position for eliminating deviation from the target position of tip 220 of welding wire 211 will be described.

[0034] <How to set the target position of the welding torch> A method for setting the target position of a welding torch when a welding wire having a bending tendency is used will be described with reference to Fig. 5 to Fig. 7. Fig. 5 is a diagram illustrating a procedure for acquiring groove shape information by a touch sensor. Fig. 6 is a diagram illustrating a correlation position acquisition process. Fig. 7 is a diagram illustrating a layered design for forming a welded joint in a groove.

[0035] The method for setting the target position of the welding torch when the welding wire 211' having a bending tendency is used includes a shape information acquisition step S101, a relative position acquisition step S102, a layered design step S103, and a target position setting step S104.

[0036] (Shape information acquisition step S101) The shape information acquisition step S101 will be described with reference to FIG. Before detecting the shape information of the groove 10 by touch sensing in the shape information acquisition step S101, the welding robot 100 automatically performs initial operation after power is applied to the controller, and the X-axis in the traveling direction, the Y-axis in the width direction of the groove 10, the Z-axis in the depth direction of the groove 10, and the torch angles θ and φ are set to the origin. A pulse motor is used as the drive source for each axis, and the travel distance or torch angle from the origin is calculated by counting pulses, but the detection direction is not limited to this.

[0037] When detecting shape information of the groove 10 by touch sensing, the X-axis in the traveling direction is stopped, and the torch angle φ is fixed perpendicular to the base material by the torch approximate linear movement mechanism 150. The torch angle adjustment mechanism 140 fixes the torch angle θ as a preset arbitrary first torch angle θ1. In this state, the robot body 110 is driven along the Y-axis in the width direction of the groove 10 and the Z-axis in the depth direction of the groove 10, and shape information of the groove 10 on the YZ-axis plane is detected.

[0038] As a preparation before touch sensing, the protruding length of the welding wire from the tip 212 is cut to a predetermined length. In this embodiment, the protruding length of the welding wire is between 20 and 25 mm, and is cut to a predetermined dimension using an automatic cutter or by an operator using a gauge or the like. In this embodiment, after cutting to the predetermined protruding length of the welding wire, detection of groove shape information is performed with the welding wire 211' that still has a bent tendency.

[0039] In the shape information acquisition step S101, the control device 600 controls the operation of the welding torch 200 by controlling the operation of the moving mechanism, and acquires the shape information of the groove 10 by touch sensing. Specifically, the detection of the shape information of the groove 10 by the touch sensor is performed by electrically detecting the contact of the tip 220' of the welding wire 211' with a bending tendency with the base metal surface, and the detected position is specified from the movement distance of the Y axis and Z axis at that time. The detection point by the touch sensor starts from, for example, point A0, and sensing is performed while moving in the direction shown by the arrow in the figure in the order of point A1, point A2, ..., point A14. Based on FIG. 5, the procedure of touch sensing for acquiring the shape information of the groove 10 in the shape information acquisition step S101 will be specifically described.

[0040] [Step 1] The Y-axis and Z-axis are driven manually or automatically so that the tip 220' of the welding wire 211', which has a tendency to bend, is located near point A0. [Step 2] Starting from point A0, the position of the workpiece surface Wu on one end side of the groove 10 is detected by detecting points A1 and A3. [Step 3] At point A4', when the position of the work surface Wu detected at points A1 and A3 has fallen a set movement distance, it is determined to be inside the groove 10, and the sensor returns to a height immediately below the work surface Wu and moves on to detection of point A5. [Step 4] By detecting points A6 and A9, a tentative inclination angle η1 of the groove wall 11 on one end side of the groove 10 is detected. [Step 5] By detecting points A5 and A8, a tentative inclination angle η2 of the groove wall 12 on the other end side of the groove 10 is detected. [Step 6] After determining a position where the root 13 of the groove 10 can be reliably detected by detecting the provisional inclination angle η1, detect point A10 of the root 13. For example, a position a predetermined distance below point A8 is actually set as the root 13. [Step 7] By detecting points A1, A3, and A10, the plate thickness H1 is calculated, and using the plate thickness H1, points A11 and A12 close to the root 13 of the groove 10 are detected, and by detecting points A12 and A6, a more accurate inclination angle η1 of the groove wall 11 on one end side is detected. In addition, by detecting points A11 and A5, a more accurate inclination angle η2 of the groove wall 12 on the other end side is determined. [Step 8] Calculate the root gap G from the intersection of the line connecting points A6 and A12 (i.e., the inclined surface on one end), and the line connecting points A5 and A11 (i.e., the inclined surface on the other end), and a straight line that is parallel to the line connecting points A3 and A1 and passes through point A10. [Step 9] Also, at point A13, it is detected whether or not there is a wall that constitutes the groove wall 12 on the other end side of the groove 10. In this embodiment, the groove 10 is a flat joint in which no wall exists. [Step 10] If no wall is detected even after passing the extension of the line connecting points A5 and A11, it is determined that there is no wall, and the work surface Wi on the other end side is detected at point A14. Next, the plate thickness H2 is calculated by detecting points A14 and A10, and the step D on both sides of the groove 10 is calculated from the difference between plate thickness H1 and plate thickness H2. [Step 11] A threshold value is set for the step D, and if the step D is greater than this threshold value, it is regarded as a T-joint groove 10 rather than a flat joint groove, and the welding conditions for the T-joint are selected. [Step 12] If the step D is below the threshold, it is considered to be a misalignment of a flat joint, and the welding conditions for a flat joint are selected.

[0041] In addition, the steps 1 to 12 of the touch sensing for acquiring the shape information of the groove 10 are not limited to the trapezoidal groove 10 shown in Fig. 5, and the groove shape can be detected in the same manner for other types of grooves, such as a V-shaped groove. In addition, the detection pitch Sp between the detection points in the touch sensing is not particularly limited and can be set appropriately. Moreover, the detection points for obtaining information on the cross-sectional shape of the groove 10 must maintain sufficient accuracy as shape information of the groove 10. For this reason, the number of detection points is preferably five or more. In addition, by selecting the positions of the detection points, it is possible to obtain detection data with higher accuracy. For example, as shown in Fig. 5, the five detection points may be set at four corners C1, C2, C3, and C4 including the upper and lower ends of the groove walls 11 and 12 on both the left and right sides, and at a portion C5 of the root portion 13. From the viewpoint of sensing efficiency, the number of detection points for obtaining groove shape information is preferably 10 or less. By the above-described touch sensing, shape information of the groove 10 can be calculated and acquired using the welding wire 211′ having a bending tendency.

[0042] (Correlation position acquisition step S102) Next, the correlation position acquisition step S102 will be described with reference to FIG. In the relative position acquisition process S102, the control device 600 acquires relative position relationship data between the position of the tip 220' of the welding wire 211' having a bending tendency and the shape of the groove 10 based on the shape information of the groove 10 acquired in the shape information acquisition process S101.

[0043] The shape information of the groove 10 acquired by touch sensing is based on the detection of the position where the tip 220' of the bent welding wire 211' contacts the base metal surface. Therefore, a correlation is established between the shape information of the groove 10 acquired by touch sensing and the position of the tip 220' of the bent welding wire 211'. That is, in the relative position acquisition step S102, as shown in Fig. 6, by setting an origin O at an arbitrary point of the groove shape drawn from the shape information of the groove 10 acquired by touch sensing, it is possible to acquire relative positional relationship data for calculating movement distances Yt, Zt from a point (coordinate) at which a tip 220' of a welding wire 211' with a bending tendency is to be arbitrarily positioned to the origin O. As a result, the tip 220' of the welding wire 211' with a bending tendency can be accurately moved to an arbitrary coordinate (Y, Z) in the groove 10.

[0044] (Layer design process S103) Next, the stacking design process S103 will be described with reference to FIG. In the layered design step S103, the control device 600 performs layered design for forming a welded joint or the like in the groove 10 based on the shape information of the groove 10 acquired in the shape information acquisition step S101. The example shown in Fig. 7 shows a layered design in which a welded joint is completed in 6 layers and 13 passes. The circled numbers in Fig. 7 show the number of welding passes designed by the layered design. When the number of layers is determined by the layered design, appropriate welding conditions are assigned to each welding pass. Next, the target position of the welding torch 200 is set for each welding pass, and the weaving width Wy is also set based on the target position. 7, the circle shown on each welding pass indicates coordinate data (Y, Z) showing the target position of welding torch 200, and the double-headed arrow indicates the weaving width Wy in each welding pass. Note that welding pass 8 to welding pass 13 are so-called straight beads without weaving, so there is no double-headed arrow indicating weaving. In passes with weaving, the coordinate data (Y, Z) showing the welding torch target position is set to the weaving end.

[0045] (Target position setting process S104) Next, the target position setting step S104 will be described with reference to FIGS. In the target position setting process S104, the control device 600 calculates movement distances Yt, Zt from the origin O to the target positions Y, Z of each welding pass in order to move the tip 220' of the welding wire 211', which has a bending tendency, to the target positions of each welding pass designed in a stacking manner, and controls the operation of the movement mechanism so that the tip 220' of the welding wire 211' moves to the target positions Y, Z of each welding pass.

[0046] As a result, when actually performing welding work based on the layered design, the robot body 110 moves the Y-axis and Z-axis to bring the tip 220' of the welding wire 211', which has a tendency to bend, to the welding torch target position (Y, Z) based on the shape information of the groove 10 and the movement distances Yt, Zt from the origin O, as shown in Fig. 6, and this position can be used as the welding start position. In addition, when weaving is involved, it is performed by swinging the Y-axis with the set weaving width Wy. As described above, according to the method for setting the target position of the welding torch of this embodiment, the tip 220' of the welding wire 211', which has a bending tendency, can be accurately positioned at the target positions (Y, Z) of each predetermined welding pass set in the layered design.

[0047] <Second embodiment> FIG. 7 shows a stacked design as an example of an embodiment of the welding torch target position setting method of the present invention. In such multi-layer welding in which the groove wall has an angle, the torch angle θ is adjusted within a range in which the welding torch does not interfere with the groove wall so that the base material of the groove wall is easily melted according to the angle of the groove wall. This can prevent defects such as poor fusion and poor penetration.

[0048] In the stacking design shown in Fig. 7, the welding torch 200 is fixed at a first torch angle θ1, which is an angle that makes it easy for the vertical plate of the groove wall 12 on the left side of the paper to melt. To be more specific, in Fig. 7, the vertical plate has a larger cross-sectional area than the groove wall 11 on the right side of the paper, and the heat input from the welding arc is easier to escape, so the first torch angle θ1, which is advantageous for the vertical plate to penetrate, is set in advance. Therefore, the torch angle adjustment mechanism 140 is expected to prevent defects such as insufficient fusion and insufficient penetration in the welding pass 4, welding pass 7, and welding pass 11 adjacent to the groove wall 11 on the right side.

[0049] Here, in the case of welding wire 211' having a tendency to bend as shown in Fig. 8, simply adjusting torch angle θ may cause tip 220' of welding wire 211' to move and deviate from the target position of welding torch 200 set in Fig. 7, which may instead induce insufficient fusion or penetration. That is, in addition to the above, the welding torch aim setting method of the second embodiment aims to correct torch angle θ so that the target position does not change even when welding wire 211 has a tendency to bend.

[0050] Here, the amount of deviation of tip 220' of welding wire 211' when torch angle θ of welding torch 200 using welding wire 211' with a bending tendency is adjusted will be described with reference to Fig. 8. Fig. 8 is a schematic diagram showing a state in which the torch angle of a welding torch using welding wire with a bending tendency is adjusted. As shown in FIG. 8 , when the angle of welding torch 200 is adjusted so that torch angle θ changes from first torch angle θ1 to second torch angle θ2, when welding wire 211 that has no bending tendency is used, welding torch 200 rotates around imaginary welding wire tip 220, whereas when welding wire 211′ that has a bending tendency is used, the position of welding wire tip 220′ shifts significantly before and after the angle adjustment of welding torch 200.

[0051] At this time, tip 220' of welding wire 211' prone to bending when at first torch angle θ1 is the target position determined in Fig. 6, and so the position can be specified as (Y1, Z1) as coordinates on the Y and Z axes. On the other hand, by changing the torch angle θ from the first torch angle θ1 to the second torch angle θ2 with respect to these coordinates (Y1, Z1), the position of tip 220' of welding wire 211' moves to coordinates (Y2, Z2), and a predetermined amount of deviation occurs. The amount of deviation of tip 220' of welding wire 211' due to changing the torch angle θ of welding wire 211' prone to bending can be expressed as deviation amounts ΔY and ΔZ in the Y and Z axes, respectively. If the deviation amounts ΔY and ΔZ are known, then by adjusting the torch angle θ from the first torch angle θ1 to the second torch angle θ2 and simultaneously correcting the deviation amounts ΔY and ΔZ using the Y-axis and Z-axis, the torch angle θ can be adjusted without moving the tip 220' of the welding wire which has a bending tendency. This will be explained in detail below.

[0052] Hereinafter, a method for setting the target position of the welding torch in the second embodiment will be specifically described with reference to Fig. 8 to Fig. 10. Fig. 9 is a schematic diagram showing a method for correcting the target position of the welding torch when the torch angle is adjusted using a welding wire with a bending tendency. Fig. 10 is a diagram showing groove shape data for a first torch angle θ1 and groove shape data for a second torch angle θ2.

[0053] A method for setting the target position of a welding torch when using a welding wire with a bending tendency includes a shape information acquisition process S101, a correlation position acquisition process S102, a stack design process S103, a target position setting process S104, a deviation amount detection process S201, a torch angle change process S202, and a deviation amount correction process S203. The following describes the steps of detecting the amount of deviation S201, changing the torch angle S202, and correcting the amount of deviation S203 as differences from the first embodiment. The order of the steps does not matter as long as the same operational effects can be achieved.

[0054] (Misalignment detection step S201) First, a specific method for determining the amounts of deviation ΔY and ΔZ in the amount of deviation detection step 201 will be described with reference to FIG. In the deviation detection process S201, the control device 600 adjusts the torch angle θ from the first torch angle θ1 to the second torch angle θ2 using the torch angle adjustment mechanism 140, and then performs touch sensing on the groove 10 and acquires shape information A2 of the groove 10 again with the welding torch 200 fixed at the second torch angle θ2. Next, as shown in FIG. 10, the control device 600 calculates the deviation amounts ΔY and ΔZ in the Y-axis and Z-axis directions based on the shape information A1 of the groove 10 acquired at the first torch angle θ1 and the shape information A2 of the groove 10 acquired at the second torch angle θ2.

[0055] Next, the torch angle changing step S202 and the deviation amount correcting step S203 will be described with reference to FIG. (Torch angle change process S202)

[0056] In the torch angle changing process S202, the control device 600 changes the torch angle θ of the welding torch 200 from a first torch angle θ1 (1 in FIG. 9) to a second torch angle θ2 (2 in FIG. 9) by controlling the operation of the torch angle adjustment mechanism 140. As a result, predetermined deviation amounts ΔY, ΔZ are generated in the tip 220' of the welding wire 211' which has a bending tendency.

[0057] (Difference amount correction process S203) In the deviation correction process S203, the control device 600 corrects the deviations ΔY and ΔZ of the welding torch 200 by controlling the operation of the moving mechanism to move the welding torch 200 in the Y-axis direction and the Z-axis direction by the deviation calculated in the deviation detection process S201 (3 in Figure 9). As a result, the torch angle θ can be changed from the first torch angle θ1 to the second torch angle θ2 without changing the target position of the tip 220' of the welding wire 211' that has a tendency to bend. As a result, even when the welding wire 211' that has a tendency to bend is used, the layer design in FIG. 7 can be applied as is.

[0058] In addition, when the appropriate torch angle θ for welding pass 4, welding pass 7, and welding pass 10 adjacent to the groove plate of the right-side groove wall 11 shown in Figure 7 is the second torch angle θ2, the torch angle θ can be adjusted to the second torch angle θ2 by the above-mentioned torch position setting method only for the necessary passes, which can lead to prevention of defects such as insufficient fusion and insufficient penetration.

[0059] In addition, the torch angle θ can be continuously and appropriately adjusted to any (desired) torch angle θi between the first torch angle θ1 and the second torch angle θ2. When adjusting the torch angle to θi, the deviation amounts Δyi and Δzi calculated by the following formulas are set as the correction amounts for the Y-axis and Z-axis. Δyi=(θi-θ1) / (θ2-θ1)·ΔY····Formula (1) Δzi=(θi-θ1) / (θ2-θ1)·ΔZ····Formula (2)

[0060] The above formula is obtained assuming that the corrections of the Y-axis and Z-axis are proportional to the rate of change of the torch angle θ. For example, the relevant welding passes are welding pass 6, welding pass 9, and welding pass 13 in Fig. 7. In passes that are not adjacent to the groove walls 11 and 12, an intermediate torch angle θi between the first torch angle θ1 and the second torch angle θ2 is expected as the appropriate torch angle θi for the groove walls 11 and 12, so when it is desired to prevent defects such as insufficient fusion and penetration, the torch angle θi is adjusted to an arbitrary value between the first torch angle θ1 and the second torch angle θ2.

[0061] In addition, the arbitrary torch angle θi does not have to be limited to between the first torch angle θ1 and the second torch angle θ2.

[0062] <Third embodiment> The method for setting the target position of the welding torch described in the second embodiment above can also be applied to a weaving method in which the welding torch 200 is repeatedly moved back and forth in the width direction of the groove 10 while performing welding work along the extension direction of the groove 10 (weld line direction). When both ends of a welding pass are adjacent to groove walls 11, 12, as in welding pass 1 and welding pass 2 in Fig. 7, better welding can be achieved by adjusting the torch angle θ at both ends of the weaving to an appropriate angle for the nearby groove walls 11, 12. For this purpose, in addition to the weaving operation in the width direction (Y-axis direction) of the groove 10, it is necessary to change the torch angle θ during weaving.

[0063] Fig. 11 is a schematic diagram showing a weaving method involving a change in torch angle. In the example shown, the weaving width Wy is shown to be in a state where the weaving is performed such that the first torch angle is θ1 at the left end of the page and the second torch angle is θ2 at the right end.

[0064] At this time, the welding robot 100 is instructed by the control device 600 to vary the Y-axis, the Z-axis, and the torch angle θ as follows. Torch angle θ: First torch angle θ1←→Second torch angle θ2 Y axis (groove left and right direction): ±(weaving width Wy + deviation ΔY) Z axis (groove thickness direction): ± deviation amount ΔZ The above movements are all set so that the movement amount and movement speed per unit time are uniform. The torch angle θ can be set to any torch angle θi between the first torch angle θ1 and the second torch angle θ2 by using equations (1) and (2).

[0065] As described above, in this embodiment, for each welding pass of the stacked design shown in FIG. 7, even if the welding wire has a bending tendency, the torch angle θ can be adjusted to an appropriate angle suitable for each welding pass without changing the target position of the welding torch 200. Furthermore, this leads to prevention of defects such as insufficient fusion and insufficient penetration, thereby improving the welding quality.

[0066] The present invention is not limited to the above-described embodiments, and the present invention also contemplates the mutual combination of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the description in the specification and well-known technologies, and these are included in the scope of protection sought.

[0067] As described above, the present specification discloses the following: (1) A method for setting a welding torch target position of a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, comprising the steps of: The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; Equipped with A shape information acquisition process of touch-sensing the groove using the welding torch and calculating shape information of the groove; A relative position acquisition process for acquiring relative positional relationship data between a tip of the welding wire having a bending tendency and a shape of the groove; A lamination design process for performing a lamination design based on the shape information of the groove; a target position setting process of moving a tip of the welding wire of the welding torch to a welding torch target position of the welding pass designed based on the correlation positional relationship data; Equipped with How to set the welding torch aim position. According to this configuration, the target position of the welding torch can be set without being affected by the bending tendency of the welding wire, thereby improving work efficiency and welding quality.

[0068] (2) The portable welding robot further includes a torch angle adjustment mechanism that rotates the welding torch around a tip of the welding wire, which is imaginary on a straight extension line of the welding torch, in a plane perpendicular to the extension direction of the groove, to change the angle of the welding torch; a displacement amount calculation step of calculating displacement amounts of the tip of the welding wire in the width direction and the depth direction at the first torch angle and the second torch angle, the touch sensing being performed at a first torch angle obtained by changing the angle of the welding torch by the torch angle adjustment mechanism and a second torch angle different from the first torch angle, based on the two pieces of acquired correlated positional relationship data; a torch angle changing process of moving a tip of the welding wire of the welding torch at a welding torch target position of the laminated designed welding pass and changing the welding torch to a desired torch angle by the torch angle adjustment mechanism; a deviation amount correction process of correcting the deviation amount at the desired torch angle, the deviation amount being calculated from the deviation amounts at the first torch angle and the second torch angle, by the movement mechanism; Further comprising: A method for setting a welding torch target position as described in (1). According to this configuration, the torch angle of the welding torch can be changed without being affected by the bending tendency of the welding wire, thereby improving work efficiency and welding quality.

[0069] (3) the second torch angle is the desired torch angle; A method for setting a welding torch target position as described in (2). According to this configuration, even if the torch angle of the welding torch is continuously changed, an error in the target position of the welding wire can be corrected, thereby improving work efficiency and welding quality. can.

[0070] (4) The torch angle adjustment mechanism is a fixed arm portion provided on a robot body side that moves along the guide rail and having an arc-shaped linear guide centered on the imaginary tip of the welding wire; a drive motor attached to the fixed arm portion and having a pinion gear on an output shaft; a movable arm portion provided on the welding torch side, meshing with the pinion gear, and including an arc rack portion along an arc centered on the imaginary tip of the welding wire, and a guide block that slides along the arc linear guide; having A method for setting a welding torch target position according to (2) or (3). According to this configuration, the angle of the welding torch can be controlled by the control device, thereby improving work efficiency.

[0071] (5) A weaving method for a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, comprising: The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; a torch angle adjustment mechanism that changes an angle of the welding torch by rotating the welding torch around a tip of a welding wire that is imaginary on a straight extension line of the welding torch within a plane perpendicular to an extension direction of the groove; Equipped with a displacement amount acquisition process for performing touch sensing of the groove using the welding torch having a first torch angle and a second torch angle different from the first torch angle, which are changed by the torch angle adjustment mechanism before welding, to calculate shape information of the groove, and acquiring correlation positional relationship data between the tip of the welding wire having a bending habit and the shape of the groove, and a displacement amount of the tip of the welding wire in the width direction of the groove and the depth direction of the groove at the first torch angle and the second torch angle; a torch angle adjustment process in which the welding torch is changed to a desired torch angle by the torch angle adjustment mechanism when welding while weaving the welding torch in the width direction of the groove; a deviation amount correction process of correcting the deviation amount at the desired torch angle, the deviation amount being calculated from the deviation amounts at the first torch angle and the second torch angle, by the movement mechanism; Equipped Weaving methods. According to this configuration, weaving welding can be performed while varying the welding torch angle according to the inclination angle to the groove wall, thereby improving work efficiency and welding quality.

[0072] (6) The first torch angle and the second torch angle are torch angles at both ends when the welding torch moves in the width direction of the groove. (5) A weaving method according to the above. According to this configuration, the torch angle of the welding torch can be changed during weaving, improving work efficiency.

[0073] (7) A welding system having a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, and a control device that controls an operation of the portable welding robot, The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; Equipped with The control device includes: Using the welding torch, touch sensing is performed on the groove to calculate shape information of the groove, and correlation position relationship data between the tip of the welding wire having a bending tendency and the shape of the groove is obtained; Based on the shape information of the groove, a layering design is performed. moving a tip of the welding wire of the welding torch to a welding torch target position of the welding pass designed according to the layered design based on the correlated positional relationship data; Welding system. According to this configuration, the target position of the welding torch can be set without being affected by the bending tendency of the welding wire, thereby improving work efficiency and welding quality. [Explanation of symbols]

[0074] 10 Bevel 50 Welding System 100 Portable welding robot 110 Robot body 120 Guide Rail 140,170 Torch angle adjustment mechanism 142 Fixed arm part 142a Guide groove (arc linear guide) 143 Movable arm part 144 Drive motor 144a Pinion gear 147 Guide body (guide block) 148 Circular rack section 200 Welding Torch 220 Tip 600 Control device θ1 First torch angle θ2 Second torch angle A1,A2 shape information

Claims

1. A method for setting a welding torch target position of a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, comprising: The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; Equipped with A shape information acquisition process of touch-sensing the groove using the welding torch and calculating shape information of the groove; A relative position acquisition process for acquiring relative positional relationship data between a tip of the welding wire having a bending tendency and a shape of the groove; A lamination design process for performing a lamination design based on the shape information of the groove; a target position setting process of moving a tip of the welding wire of the welding torch to a welding torch target position of the welding pass designed based on the correlation positional relationship data; Equipped with How to set the welding torch aim position.

2. The portable welding robot further includes a torch angle adjustment mechanism that rotates the welding torch around a tip of the welding wire imaginary on a straight extension line of the welding torch in a plane perpendicular to the extension direction of the groove, to change the angle of the welding torch, a displacement amount calculation step of calculating displacement amounts of the tip of the welding wire in the width direction and the depth direction at the first torch angle and the second torch angle, the first torch angle being obtained by changing the angle of the welding torch by the torch angle adjustment mechanism, and a displacement amount calculation step of calculating displacement amounts of the tip of the welding wire in the width direction and the depth direction at the first torch angle and the second torch angle based on the two pieces of correlated positional relationship data obtained; a torch angle changing process of moving a tip of the welding wire of the welding torch at a welding torch target position of the laminated designed welding pass and changing the welding torch to a desired torch angle by the torch angle adjustment mechanism; a deviation amount correction process of correcting the deviation amount at the desired torch angle, the deviation amount being calculated from the deviation amounts at the first torch angle and the second torch angle, by the moving mechanism; Further comprising: The welding torch target position setting method according to claim 1 .

3. the second torch angle being the desired torch angle; The welding torch target position setting method according to claim 2 .

4. The torch angle adjustment mechanism includes: a fixed arm portion provided on a robot body side that moves along the guide rail and having an arc-shaped linear guide centered on the imaginary tip of the welding wire; a drive motor attached to the fixed arm portion and having a pinion gear on an output shaft; a movable arm portion provided on the welding torch side, meshing with the pinion gear, and including an arc rack portion along an arc centered on the imaginary tip of the welding wire, and a guide block that slides along the arc linear guide; having The method for setting a welding torch target position according to claim 2 or 3.

5. A weaving method for a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, comprising: The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; a torch angle adjustment mechanism that changes an angle of the welding torch by rotating the welding torch around a tip of a welding wire that is imaginary on a straight extension line of the welding torch within a plane perpendicular to an extension direction of the groove; Equipped with a displacement amount acquisition process for performing touch sensing of the groove using the welding torch having a first torch angle and a second torch angle different from the first torch angle, which are changed by the torch angle adjustment mechanism before welding, to calculate shape information of the groove, and acquiring correlation positional relationship data between the tip of the welding wire having a bending tendency and the shape of the groove, and a displacement amount of the tip of the welding wire in the width direction of the groove and the depth direction of the groove at the first torch angle and the second torch angle; a torch angle adjustment process in which the welding torch is changed to a desired torch angle by the torch angle adjustment mechanism when welding while weaving the welding torch in the width direction of the groove; a deviation amount correction process of correcting the deviation amount at the desired torch angle, the deviation amount being calculated from the deviation amounts at the first torch angle and the second torch angle, by the moving mechanism; Equipped Weaving methods.

6. The first torch angle and the second torch angle are torch angles at both ends when the welding torch moves in the width direction of the groove. The weaving method according to claim 5.

7. A welding system having a portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, and a control device that controls the operation of the portable welding robot, The portable welding robot comprises: A welding torch, A moving mechanism that moves the welding torch in an extension direction of the groove, a width direction of the groove, and a depth direction of the groove; Equipped with The control device includes: Using the welding torch, touch sensing is performed on the groove to calculate shape information of the groove, and correlation position relationship data between the tip of the welding wire having a bending tendency and the shape of the groove is obtained; Based on the shape information of the groove, a layering design is performed. moving a tip of the welding wire of the welding torch to a welding torch target position of the welding pass designed according to the layered design based on the correlated positional relationship data; Welding system.

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