Portable welding robot and welding torch target position setting method

Abstract

To provide a portable welding robot in which a torch angle adjustment mechanism for changing a welding torch angle of a welding torch while maintaining a tip position of a welding wire is configured to be small, and a welding torch target position setting method using the portable welding robot.SOLUTION: A robot main body including a welding torch and a moving mechanism that moves the welding torch in an extending direction of a groove, a width direction of the groove, and a depth direction of the groove; A torch angle adjustment mechanism configured to change a welding torch angle of the welding torch by rotating the welding torch around a tip of the welding wire assumed on a linear extension line of the welding torch, the torch angle adjustment mechanism includes a moving body that moves along the width direction of the groove, a sliding part that is provided in the moving body and rotates around a slide rotation axis extending in the extending direction of the groove, a guide rail on which the sliding part slides, and a movable support that is attached to the guide rail, supports the welding torch, and is inclined with the rotation of the guide rail, and slides the sliding part with respect to the guide rail and rotates the guide rail and the sliding part around the slide rotation axis.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] The present invention relates to a portable welding robot and a method for setting a welding torch target position. [Background technology]

[0002] In the manufacture 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 system in which the workpiece (hereinafter referred to as the "work") is placed on 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 in on-site welding, taking advantage of their portability.

[0003] In order to prevent defects such as insufficient fusion and penetration in the weld in such portable welding robots, Patent Document 1 discloses 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 with an arc-shaped groove of a constant 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 at a desired position in the arc-shaped groove, and a welding torch holder connected to the slide member. 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 achieved 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 has an arc-shaped groove of a certain curvature centered on the wire target position of the welding torch, and a circular rack of the same curvature is attached to the guide member, and a pinion that meshes with the circular rack is attached to a slide member. The pinion moves along the circular rack as it rotates, and the welding torch holder moves along the guide, thereby enabling the welding torch angle to be adjusted with high precision. [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 torch angle adjustment mechanism for adjusting the angle of a welding torch moves the welding torch holder along a guide member that has an arc-shaped groove with a constant curvature centered on the wire target position of the welding torch. However, in order to adjust the welding torch angle centered on the wire target position of the welding torch, the guide member needs to be large enough to extend to both outer sides of the groove width, which can cause interference with other components during welding. Furthermore, shortening the guide member in response to this can cause a problem in that the range in which the welding torch angle can be adjusted can be narrowed.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a portable welding robot having a compact torch angle adjustment mechanism that changes the welding torch angle of a welding torch while maintaining the tip position of a welding wire, and a method for setting the welding torch aim position using a portable welding robot. [Means for solving the problem]

[0008] The above object of the present invention can be achieved by the following configuration. (1) A portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, A welding torch, A robot body having a movement mechanism that moves the welding torch in the extension direction of the groove, the width direction of the groove, and the depth direction of the groove; a torch angle adjustment mechanism that changes the welding torch angle 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 the extending direction of the groove; Equipped with The torch angle adjustment mechanism includes a moving body that moves relative to the robot body along the width direction of the groove, a sliding part that is provided on the moving body and rotates around a sliding rotation axis that extends in the extension direction of the groove, a guide rail on which the sliding part slides, and a movable support body that is attached to the guide rail, supports the welding torch, and tilts with the rotation of the guide rail, and causes the sliding part to slide relative to the guide rail and rotates the guide rail and the sliding part around the sliding rotation axis. Portable welding robot. (2) A method for setting a welding torch target position using a portable welding robot according to (1), which moves along the guide rail attached to the workpiece having the groove and welds the workpiece, comprising: A shape information acquisition process in which the groove is touch-sensed using the welding torch and shape information of the groove is calculated; a correlation position acquisition step of acquiring correlation position relationship data between the tip of the welding wire and the shape of the groove; a lamination design process for performing lamination design based on the groove shape information; 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; a welding torch angle setting process for setting a welding torch angle of the welding torch for each welding pass designed by the layered process; Equipped with How to set the welding torch's target position. [Effects of the Invention]

[0009] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a compact torch angle adjustment mechanism that can change the welding torch angle of a welding torch while maintaining the tip position of the welding wire. [Brief explanation of the drawings]

[0010] [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 welding robot in a neutral state with a welding torch standing upright. [Figure 2B] FIG. 2B is a diagram showing the welding robot in a first tilted state in which the welding torch is tilted at a first torch angle. [Figure 2C] FIG. 2C is a diagram showing the welding robot in a second tilted state in which the welding torch is tilted to a second torch angle. [Figure 3] FIG. 3 is a diagram showing the torch approximate linear movement mechanism. [Figure 4A] FIG. 4A is a front view showing the torch angle adjustment mechanism. [Figure 4B] FIG. 4B is a side view showing the torch angle adjustment mechanism. [Figure 5] FIG. 5 is a front view of the torch angle adjustment mechanism showing a first tilt state in which the welding torch is tilted at a first torch angle. [Figure 6] FIG. 6 is a front view of the torch angle adjustment mechanism showing a second tilt state in which the welding torch is tilted to a second torch angle. [Figure 7A] FIG. 7A is a front view of a model diagram of the torch angle adjustment mechanism 160 in a neutral state, with the drive system omitted. [Figure 7B]FIG. 7B is a side view of a model diagram in which the drive system of the torch angle adjustment mechanism in the neutral state is omitted. [Figure 8] FIG. 8 is a model diagram in which the drive system of the torch angle adjustment mechanism is omitted, comparing the neutral state, the first tilt state, and the second tilt state. [Figure 9] FIG. 9 is a diagram illustrating a procedure for acquiring groove shape information using a touch sensor. [Figure 10] FIG. 10 is a diagram illustrating the correlation position acquisition process. [Figure 11] FIG. 11 is a diagram showing a layered design for forming a welded joint in a groove. [Figure 12] FIG. 12 is a diagram showing the amount of deviation when the welding torch angle is changed. [Figure 13] FIG. 13 is a diagram showing groove shape data detected in the first tilt state and groove shape data detected in the second tilt state. [Figure 14] FIG. 14 is a schematic diagram showing a weaving method involving a change in torch angle. [Figure 15A] FIG. 15A is a front view showing the torch angle adjustment mechanism of the second embodiment. [Figure 15B] FIG. 15B is a side view showing the torch angle adjustment mechanism of the second embodiment. [Figure 15C] FIG. 15C is a rear view showing the torch angle adjustment mechanism of the second embodiment. [Figure 16] FIG. 16 is a front view of the torch angle adjustment mechanism of the second embodiment, showing a first tilted state in which the welding torch is tilted at a first torch angle. [Figure 17] FIG. 17 is a front view of the torch angle adjustment mechanism of the second embodiment, showing a second tilted state in which the welding torch is tilted at a second torch angle. DETAILED DESCRIPTION OF THE INVENTION

[0011] The configuration of a welding system to which the present invention is applied will be described below with reference to the accompanying drawings. Note that each drawing is created for the purpose of explaining the present embodiment of the present invention, and the present invention is not limited to the contents of the drawings.

[0012] <Welding system configuration> 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 control device 600.

[0013] (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 supply control cable 620. Control device 600 has a data storage unit 601 that stores teaching data that defines in advance the operation pattern, welding start position, welding end position, welding conditions, weaving operation, 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 operation of welding robot 100 and the welding conditions.

[0014] 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. Control unit 604 is configured to be able to execute welding torch angle setting control for changing the welding torch angle without moving the wire target position of tip 220 of the welding wire.

[0015] (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 then sent from wire feeder 300 to welding torch 200 via conduit tube 420.

[0016] (Shielding gas supply source 500) Shielding gas supply source 500 is composed of a container filled with shielding gas and accessory components such as a valve. Shielding gas is sent from shielding gas supply source 500 to feeder 300 via gas tube 510. The shielding gas sent to feeder 300 is sent to welding torch 200 via conduit tube 420. The shielding gas sent to welding torch 200 flows inside welding torch 200, is guided by nozzle 210, and is ejected from the tip side of welding torch 200. For example, argon (Ar), carbon dioxide (CO2), or a mixture of these may be used as the shielding gas.

[0017] (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, and the like. 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, or titanium. Furthermore, the diameter of the welding wire 211 is also not particularly limited.

[0018] (Welding Robot 100) Fig. 2A is a diagram showing welding robot 100 in a neutral state with welding torch 100 upright. Fig. 2B is a diagram showing welding robot 100 in a first tilted state with the welding torch tilted to a first torch angle. Fig. 2C is a diagram showing welding robot 100 in a second tilted state with the welding torch tilted to a second torch angle. 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 connector 130 , a torch angle adjustment mechanism 160 , and a torch approximate linear movement mechanism 150 . The robot body 110 moves along a guide rail 120 that extends along a groove 10 formed in the 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 160 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 can be seen in FIGS. 2A to 3.

[0019] The welding robot 100 also has a detection means for detecting the shape of the groove to be welded. The welding robot 100 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, using a touch sensor as the detection means.

[0020] The robot body 110 has a movement mechanism that can move the welding torch 200 in three orthogonal axes, including 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 surface and corresponds to the direction of the weld line, as indicated by the arrow X in FIG. 2A. The Y-axis movement mechanism slides the 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 is also the width direction of the groove 10, as shown by the arrow Y in Figure 2A. The Z-axis movement mechanism moves the robot body 110 in an expanding and contracting direction in the Z-axis direction, which is the depth direction of the groove 10 perpendicular to the X-axis and Y-axis directions, as indicated by the arrow Z in FIG. 2A. The movement mechanism may be configured to move welding torch 200 in the groove extension direction, the groove width direction, and the groove depth direction.

[0021] The torch connection portion 130 includes torch clamps 132 and 134 that secure the welding torch 200 . Torch connecting unit 130 is configured so that welding torch angle θ at the tip of welding torch 200 can be adjusted by torch angle adjustment mechanism 160 provided on robot body 110. Welding torch angle θ is an angle centered on tip 220 of the welding wire, which is an imaginary straight extension of welding torch 200, and is the angle at which welding torch 200 is tilted 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 160, without changing the height position of welding torch 200. Torch angle φ is an angle centered on tip 220 of the welding wire, which is supported so as to be movable in the extension direction of groove 10 (X-axis direction) and is an angle at which welding torch 200 is tilted with respect to the welding line direction.

[0022] 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 torch angle adjustment mechanism 160, and a crank 152 connecting sliding table 151 and welding torch rotation drive part 153. This configuration can be seen in Figure 3.

[0023] Sliding table 151 is a plate-like member extending along welding torch 200, and has a longitudinal groove 151a formed in the middle thereof. 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 rotary shaft 154 , and the other end is connected to the upper end of the sliding table 151 via a connecting pin 155 .

[0024] According to this configuration, when the crank 152 rotates around the rotation axis 154 by a drive motor (not shown), the sliding table 151 rotates around the fixed pin 156 as a fulcrum and moves along the long groove 151a, guided by the fitted fixed pin 156. That is, torch connector 130 to which welding torch 200 is attached rotates crank 152 as shown by arrow R2 in Figure 3, tilting welding torch 200 and driving tip 220 of welding wire 211 along the approximate straight line indicated by imaginary line IL in Figure 3 with respect to the X-axis direction. In other words, torch angle φ of welding torch 200 supported by torch connector 130 can be adjusted arbitrarily without changing the height position of tip 220 of welding wire 211. This configuration can be seen in Figure 3.

[0025] As described above, welding torch 200 can move in the X-axis direction, which is the extension direction of groove 10, by moving robot body 110 along guide rail 120. Furthermore, welding torch 200 can move in the Y-axis direction, which is the width direction of groove 10, and in the Z-axis direction, which is the depth direction of groove 10, by controlling the position of torch connecting part 130 supported by robot body 110. In addition, the welding torch angle φ of the welding torch 200 can be adjusted by rotating the welding torch 200 along the XZ plane along the welding line using the torch approximate linear movement mechanism 150 depending on the construction situation, for example, by setting a forward angle or a backward angle. In addition, welding torch 200 can be rotated by torch angle adjustment mechanism 160 along the YZ plane perpendicular to the welding line around tip 220 of the welding wire, which is assumed to be a straight line extension of welding torch 200.

[0026] <Specific Configuration of Torch Angle Adjustment Mechanism 160> 2A to 2C, 4A, and 4B, a specific configuration of the torch angle adjustment mechanism 160 will be described. Fig. 4A is a front view showing the torch angle adjustment mechanism 160. Fig. 4B is a side view showing the torch angle adjustment mechanism 160.

[0027] The torch angle adjustment mechanism 160 includes a slide support part 161 , a slide mechanism part 162 , a rotation mechanism part 163 , a drive motor 164 , a moving body 165 , and a crank support part 166 . The slide support part 161 is a support member fixed to the movable body 112 that slides in the Y-axis direction relative to the robot body 110. The slide mechanism 162 supports the moving body 165 between the groove 10 and the robot body 110 (slide support part 161) so that the moving body 165 can slide in the Y-axis direction. The moving body 165 supports a rotation mechanism 163 and a drive motor 164 . The rotation mechanism 163 rotatably supports the welding torch rotation drive unit 153 that constitutes the torch approximate linear movement mechanism 150 via a linear rail 188, and the welding torch 200 is attached and fixed to the welding torch rotation drive unit 153 via the torch approximate linear movement mechanism 150. The crank support portion 166 changes the posture (inclination) of the linear motion rail 188 constituting the rotation mechanism portion 163 in accordance with the height position (rotation position) of the linear motion rail 188 . As a result, torch angle adjustment mechanism 160 can adjust welding torch angle θ by tilting welding torch 200 without substantially moving the position of welding wire tip 220. Each component will be described below.

[0028] The slide mechanism 162 has a board rail 171 that extends in the Y-axis direction and has its base end attached and fixed to the slide support 161 side, a board sliding part 172 that is slidably attached to the bottom of the board rail 171, a rack support 173 that is attached to the top of the board rail 171, and a slide rack part 174 that is attached and fixed to the rack support 173 and extends in the Y-axis direction along the board rail 171.

[0029] The upper end of the moving body 165 protruding in the Y-axis direction is attached and fixed to the lower surface of the board sliding part 172, so that the moving body 165 is supported so as to be slidable in the Y-axis direction along the board rail 171. The movable body 165 extends in the vertical direction, has a rotation mechanism part 163 attached to the lower part, a drive motor 164 attached to one side of the vertical part in the Y direction, and a protruding arm 192 of a crank support part 166 attached and fixed to the other side of the upper part in the Y direction.

[0030] The drive motor 164 has an output shaft 164a that protrudes upward (in the Z-axis direction) from its upper end, an output gear 176 provided on the output shaft 164a, a bevel gear 177 that meshes with the output gear 176, a drive rotation shaft 178 that extends in the X-axis direction and rotates integrally with the bevel gear 177, a pair of motor support plates 179, 179 that are a pair of plate-like members arranged side by side in the X-axis direction and have their upper ends fixed to the moving body 165 side and on which the drive rotation shaft 178 is journaled, and a first gear 175 that is provided at one axial end of the drive rotation shaft 178 and drives around the drive rotation shaft 178. An upper portion of a first gear 175 driven by the drive motor 164 is engaged with a slide rack portion 174. This configuration can be seen in FIGS. 4A and 4B.

[0031] The rotation mechanism 163 extends in the X-axis direction and includes a sliding rotation shaft 181 fixed to the lower part of the moving body 165, a sector gear 182 journaled on the sliding rotation shaft 181, a first rotation shaft 183 disposed above the sliding rotation shaft 181, a second gear 184 and a third gear 185 that rotate integrally with the first rotation shaft 183, a support block 180 journaled on the first rotation shaft 183, and a sliding part 186 provided on the support block 180. The torch approximate linear movement mechanism 150 includes a fourth gear 187 provided on the sliding portion 186, a linear rail 188 to which the sliding portion 186 is slidably assembled, a rotating side rack 189 extending along the linear rail 188 and supported by the linear rail 188, and a movable body fixing portion 190 for fixing the welding torch rotation drive portion 153 that constitutes the torch approximate linear movement mechanism 150 to the lower end of the rotating side rack 189 (or the linear rail 188). The sector gear 182 has an outer gear 182 a that meshes with the first gear 175 and an inner gear 182 b that meshes with the second gear 184 . The support block 180 is provided between the second gear 184 and the third gear 185 in the X-axis direction, and is connected to a rotating arm portion 197 that is journaled on the sliding rotation shaft 181, thereby rotating in conjunction with the rotation of the sector gear 182. The third gear 185 meshes with a fourth gear 187 that is journaled on a second rotating shaft 191 that is fixed to the support block 180 or the sliding portion 186 , and the fourth gear 187 meshes with a rotating rack 189 . As a result, the rotation mechanism 163 can use the driving force of the drive motor 164 to slide the sliding part 186 along the linear motion rail 188 and rotate the sliding part 186 and the linear motion rail 188 around the sliding rotation shaft 181. This configuration can be seen in Figures 4A and 4B.

[0032] The crank support portion 166 connects the rotation mechanism portion 163 to a linear rail 188, which is a guide rail, and thereby determines the movement direction of the welding torch rotation drive portion 153 that constitutes the torch approximate linear movement mechanism 150 via the linear rail 188. The crank support portion 166 has a protruding arm 192 , a crank rotation shaft 193 , a crank arm 194 , a hinge portion 195 , and a connecting portion 196 . The protruding arm 192 has its base end supported by the moving body 165, extends in the Y-axis direction opposite to the robot body 110, and has a crank rotation shaft 193 journaled at its tip. One end of a crank arm 194 is rotatably supported on the crank rotation shaft 193 . The other end of the crank arm 194 is pivotally supported by a hinge portion 195 provided on a connecting portion 196 , and is fixed to the upper end portion of the linear motion rail 188 via the connecting portion 196 .

[0033] (Action and effect) Next, the operation of the above-mentioned torch angle adjustment mechanism 160 will be described with reference to Figures 4A to 6. Figure 5 is a front view of the torch angle adjustment mechanism showing a first tilt state in which the welding torch is tilted to a first torch angle. Figure 6 is a front view of the torch angle adjustment mechanism showing a second tilt state in which the welding torch is tilted to a second torch angle.

[0034] As shown in FIG. 5, when the first gear 175 of the slide mechanism part 162 of the torch angle adjustment mechanism 160 is driven to rotate in the forward direction (see 198a in FIG. 5), the movable body 165 slides a predetermined distance a along the substrate rail 171 toward the robot main body 110 (see 198b in FIG. 5).

[0035] In the rotation mechanism 163 of the torch angle adjustment mechanism 160, when the first gear 175 is driven to rotate in the forward direction (see 198a in FIG. 5), the sector gear 182 rotates to one side (see 198c in FIG. 5), and the sliding part 186 rotates integrally via the rotating arm 197 and the support block 180. Accordingly, the sliding part 186 slides relatively toward the upper side of the linear motion rail 188, causing the linear motion rail 188 to slide downward (see 198d in FIG. 5). As a result of the above operation, the hinge portion 195 of the crank support portion 166 moves in an arc, causing the linear motion rail 188 to tilt to one side (clockwise in FIG. 5) at a predetermined angle (+θa). That is, the movable body fixing portion 190, which is integral with the linear motion rail 188, also tilts, and the welding torch rotation drive portion 153, which is fixed to the movable body fixing portion 190, also tilts at the predetermined angle (+θa). This action switches the welding torch angle θ of the welding torch 200 supported via the torch approximate linear movement mechanism 150 from the neutral state, in which the welding torch angle θ is 0° and the welding torch 200 is vertical, to a first tilt state in which the welding torch angle θ of the welding torch 200 is tilted clockwise by a predetermined angle (+θa) to one side. The tilt angle of the linear motion rail 188 and the tilt angle of the welding torch 200 are configured to match.

[0036] As shown in FIG. 6, when the first gear 175 of the slide mechanism 162 of the torch angle adjustment mechanism 160 is driven to rotate in the reverse direction (see 199a in FIG. 6), the movable body 165 slides a predetermined distance b along the board rail 171 to the opposite side of the robot body 110 (see 199b in FIG. 6).

[0037] 6, in the rotation mechanism unit 163 of the torch angle adjustment mechanism 160, when the first gear 175 is rotationally driven in the reverse direction (see 199a in FIG. 6), the sector gear 182 rotates to the other side (see 199c in FIG. 6), and the sliding unit 186 rotates integrally via the rotating arm unit 197 and the support block 180. Accordingly, the sliding unit 186 slides relatively toward the lower side of the linear motion rail 188, causing the linear motion rail 188 to slide upward (see 199d in FIG. 6). As a result of the above operation, hinge portion 195 of crank support portion 166 moves in an arc, causing linear motion rail 188 to tilt at a predetermined angle (-θb) to the other side (counterclockwise in FIG. 6). That is, movable body fixing portion 190, which is integrated with linear motion rail 188, also tilts, causing welding torch rotation drive portion 153, which is fixed to movable body fixing portion 190, to further tilt, and welding torch angle θ of welding torch 200 supported via torch approximate linear movement mechanism 150 can be switched from the neutral state, in which welding torch angle θ = 0°, in which welding torch 200 is vertical, to a second tilt state in which welding torch angle θ is tilted counterclockwise by a predetermined angle (-θb) to the other side.

[0038] Next, a specific description will be given of the operation of the welding torch by the above-mentioned torch angle adjustment mechanism 160 with reference to Figures 7A to 8. Figure 7A is a front view of a model diagram of the torch angle adjustment mechanism 160 in the neutral state, omitting the drive system. Figure 7B is a side view of a model diagram of the torch angle adjustment mechanism in the neutral state, omitting the drive system. Figure 8 is a diagram comparing the neutral state, the first tilt state, and the second tilt state in a model diagram of the torch angle adjustment mechanism, omitting the drive system.

[0039] 7A to 8 show, of torch angle adjustment mechanism 160, movable body 165, slide mechanism 162 (board rail 171 and board sliding portion 172), turning mechanism 163 (sliding rotation shaft 181, sliding portion 186, and linear motion rail 188), crank support portion 166 (extension arm 192, crank rotation shaft 193, crank arm 194, and hinge portion 195), and movable support portion 167. Movable support portion 167 here refers to the portion from movable body fixing portion 190 to welding torch 200 supported via torch approximate linear movement mechanism 150 in FIG. 4A that is fixed as a single unit, and therefore the portion from movable body fixing portion 190 to welding torch 200 is represented as movable support portion 167.

[0040] As shown in FIG. 8 , when the above-described torch angle adjustment mechanism 160 is set to a first tilted state (a) by rotating welding torch 200 by angle +θa clockwise around tip 220 of welding wire as an axis from a neutral state (o) where welding torch 200 is vertical and welding torch angle θ=0°, the rotation mechanism 163 causes the tip position of welding torch 200 to shift by a predetermined distance a in the direction opposite to robot body 110 as welding torch 200 rotates. However, this deviation in the Y-axis direction is corrected by welding torch 200 automatically sliding by the predetermined distance a to the right side of the page as welding torch 200 rotates. Similarly, as shown in FIG. 8 , when the above-described torch angle adjustment mechanism 160 is set to a second tilted state (b) by rotating welding torch 200 counterclockwise by angle −θb around tip 220 of the welding wire as an axis from a neutral state (o) where welding torch 200 is vertical and welding torch angle θ=0°, the rotation mechanism 163 causes the tip position of welding torch 200 to shift by a predetermined distance b in a direction approaching robot body 110 as welding torch 200 rotates, but this deviation in the Y-axis direction is corrected by welding torch 200 automatically sliding by the predetermined distance b to the left side of the page as welding torch 200 rotates.

[0041] That is, torch angle adjustment mechanism 160 can change welding torch angle θ by controlling the drive of single drive motor 164 using control device 600 or the like, without moving the tip position of welding torch 200 much.

[0042] At this time, torch angle adjustment mechanism 160 slides movable body 165 (the entire torch angle adjustment mechanism 160) along base rail 171 so as to offset the amount of horizontal movement of the tip of welding torch 200 (welding wire 211) that accompanies a change in welding torch angle θ of welding torch 200, but it is possible to geometrically calculate how much the tip of welding torch 200 moves horizontally at the angle at which welding torch 200 rotates. For this reason, by calculating in advance the relationship between the rotation angle of welding torch 200 and the amount of movement of the tip of welding torch 200, movable body 165 can be slid in accordance with the rotation angle of welding torch 200 so that the position of the tip of welding torch 200 does not move.

[0043] Furthermore, torch angle adjustment mechanism 160 can move welding wire tip 220 in a linear approximation along a horizontal line by appropriately determining the length of crank arm 194 so that the position of hinge portion 195 is on a circle centered on crank rotation shaft 193 in welding torch 200's neutral state (o), first tilted state (a), and second tilted state (b). Furthermore, by appropriately setting length K of linear motion rail 188, vertical length H from welding wire tip 220 to sliding rotation shaft 181, and length M of movable support portion 167, the error in the linear approximation can be minimized.

[0044] Torch angle adjustment mechanism 160 can also adjust the driving position of drive motor 164 to adjust welding torch angle θ to any angle between −θb and +θa. Furthermore, in the above-described torch angle adjustment mechanism 160, the tip 220 of the welding wire moves approximately linearly along the horizontal line, so strictly speaking, the tip 220 of the welding wire moves up and down slightly deviating from the horizontal line. This deviation of the tip 220 of the welding wire can be corrected by the welding torch angle setting method described below.

[0045] <How to set the welding torch target position and welding torch angle> Next, a method for setting the target position of the welding torch and the welding torch angle when a welding wire is used will be described with reference to Figs. 9 to 12. Fig. 9 is a diagram illustrating the procedure for acquiring groove shape information using a touch sensor. Fig. 10 is a diagram illustrating the correlation position acquisition process. Fig. 11 is a diagram illustrating a layer design for forming a welded joint in the groove. Fig. 12 is a diagram illustrating the amount of deviation when the welding torch angle is changed. Fig. 13 is a diagram illustrating groove shape data detected in a first tilt state and groove shape data detected in a second tilt state.

[0046] The method for setting the welding torch target position and welding torch angle 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 torch angle change process S105, and a torch angle correction process S106.

[0047] (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 from the origin or the welding torch angle is calculated by counting pulses, but the detection direction is not limited to this.

[0048] When detecting the 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. In addition, the torch angle adjustment mechanism 160 fixes the welding torch angle θ to a preset arbitrary first torch angle θ1. In this state, the robot main 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.

[0049] As a preparation before touch sensing, the welding wire is cut to a predetermined length so that it protrudes from the tip 212. In this embodiment, the welding wire protrusion length 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 the welding wire is cut to the predetermined protrusion length, the welding wire 211 is used to detect groove shape information.

[0050] In the shape information acquisition step S101, the control device 600 controls the operation of the moving mechanism to control the operation of the welding torch 200, and acquires shape information of the groove 10 by touch sensing. Specifically, detection of shape information of the groove 10 by the touch sensor electrically detects contact of the tip 220 of the welding wire with the base metal surface, and identifies the detected position from the movement distance in the Y and Z axes at that time. For example, the detection point by the touch sensor starts from point A0, and sensing is performed while moving in the direction indicated by the arrow in the figure in the order of point A1, point A2, ..., point A14. The touch sensing procedure for acquiring shape information of the groove 10 in the shape information acquisition step S101 will be specifically described with reference to FIG. 9.

[0051] [Step 1] The Y-axis and Z-axis are driven manually or automatically so that the tip 220 of the welding wire is located near point A0. [Step 2] Starting from point A0, the position of the work 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 by the set movement distance, it is determined to be inside the groove 10, and the robot returns to a height immediately below the work surface Wu and moves towards detecting point A5. [Step 4] By detecting points A6 and A9, the provisional 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, the provisional 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 portion 13 of the groove 10 can be reliably detected by detecting the provisional inclination angle η1, the A10 point of the root portion 13 is detected. For example, in practice, the root portion 13 is set to a position a predetermined distance below the A8 point. [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 near the root 13 of the groove 10 are detected, and points A12 and A6 are detected to more accurately determine the inclination angle η1 of the groove wall 11 on one end side. In addition, points A11 and A5 are detected to more accurately determine the inclination angle η2 of the groove wall 12 on the other end side. [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) with 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 groove 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, by detecting points A14 and A10, the plate thickness H2 is calculated, 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 in advance for the step D, and if it is greater than that, it is considered to be 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 the flat joint, and the welding conditions for the flat joint are selected.

[0052] Note that steps 1 to 12 of touch sensing for acquiring shape information of the groove 10 are not limited to the trapezoidal groove 10 shown in Fig. 9, and the groove shape can also be detected by the same procedure for other grooves, such as a V-shaped groove. Also, the detection pitch Sp between the detection points in touch sensing is not particularly limited and can be set as appropriate. Furthermore, 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 purpose, the number of detection points is preferably five or more. Furthermore, by selecting the positions of the detection points, it is possible to obtain detection data with higher accuracy. For example, as shown in Fig. 9, 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 one point at a portion C5 of the root portion 13. From the viewpoint of sensing efficiency, it is preferable that the number of detection points for obtaining groove shape information is 10 or less. By touch sensing the welding wire 211 as described above, shape information of the groove 10 can be calculated and acquired.

[0053] (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 and the shape of the groove 10 based on the shape information of the groove 10 acquired in the shape information acquisition process S101. 10, in the relative position acquisition step S102, by setting an origin O at an arbitrary point on 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) where the tip 220 of the welding wire is to be arbitrarily positioned to the origin O. This makes it possible to accurately move the tip 220 of the welding wire to any coordinate (Y, Z) within the groove 10.

[0054] (Layer design process S103) Next, the stacking design step S103 will be described with reference to FIG. In the layer design step S103, the control device 600 performs layer 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 Figure 11 shows a layer design in which a welded joint is completed in 6 layers and 13 passes. The circled numbers in Figure 11 indicate the number of welding passes designed by the layer design. Once the number of layers is determined by the layer 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. 11, the circle shown for each welding pass indicates coordinate data (Y, Z) that represents the target position of welding torch 200, and the double-headed arrow indicates the weaving width Wy for each welding pass. Note that welding passes 8 to 13 do not weave, and are so-called straight beads, so there are no double-headed arrows indicating weaving. For passes that involve weaving, the coordinate data (Y, Z) that represents the welding torch target position is set at the weaving end.

[0055] (Target position setting step 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 to the target positions Y, Z of each welding pass in the stacking design, and controls the operation of the movement mechanism so that the tip 220 of the welding wire moves to the target positions Y, Z of each welding pass.

[0056] As a result, when actually performing welding work based on the layered design, the tip 220 of the welding wire can be brought to the welding torch target position (Y, Z) by moving the Y-axis and Z-axis of the robot body 110 based on the shape information of the groove 10 and the movement distances Yt, Zt from the origin O, as shown in Fig. 9, and this position can be used as the start of welding. Furthermore, if weaving is involved, it is performed by oscillating the Y-axis by 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 can be accurately positioned at the target position (Y, Z) of each predetermined welding pass set in the layer design.

[0057] (Torch angle change process S105) In the torch angle changing process S105, the control device 600 controls the operation of the drive motor 164 of the torch angle adjustment mechanism 160 to set the welding torch angle θ to a predetermined welding torch angle for each welding pass, in the same way as when moving the tip 220 of the welding wire to the target position for each welding pass that is designed in layers.

[0058] In the example of the layer design shown in Figure 11, in multi-layer welding where the groove wall has an angle, defects such as insufficient fusion and penetration can be prevented by adjusting the welding torch angle θ within a range where the welding torch does not interfere with the groove wall so that the base material of the groove wall can easily penetrate depending on the angle of the groove wall. Depending on the welding pass, for example, for passes adjacent to the groove wall, the welding torch angle θ is adjusted so that it is as perpendicular as possible to the groove wall in order to obtain penetration of the groove wall. Also, for surface welding passes, the welding torch angle θ is adjusted so that it is perpendicular to the plate thickness direction to reduce the flow of weld metal and improve the finish of the weld joint surface. In such a case, it is necessary to prevent the initially determined target position of each welding pass from moving even if the welding torch angle θ is changed multiple times. However, by using the above-described torch angle adjustment mechanism 160, the target position of the tip 220 of the welding wire hardly moves even if the welding torch angle θ is changed multiple times. However, in the above-described torch angle adjustment mechanism 160, the tip 220 of the welding wire moves approximately linearly along the horizontal line, so strictly speaking, the tip 220 of the welding wire moves up and down slightly deviating from the horizontal line. This deviation of the tip 220 of the welding wire is corrected by the following process (control).

[0059] (Torch angle correction process S106) FIG. 12 shows the positional relationship of tip 220 of welding wire (target position of the wire) when torch angle adjustment mechanism 160 is used to switch from a first tilt state in which welding torch angle θ of welding torch 200 is changed to first torch angle +θa to a second tilt state in which welding torch angle θ is changed to second torch angle −θb. As shown in FIG. 12, when the welding torch angle θ is changed from the first torch angle +θa to the second torch angle −θb by the torch angle adjustment mechanism 160, the tip 220 of the welding wire moves slightly toward the center. In the torch angle correction step S106, the deviation amounts ΔY and ΔZ of the tip 220 of the welding wire in the Y-axis direction and the Z-axis direction, which occur slightly when the torch angle adjustment mechanism 160 changes the welding torch angle θ, are corrected.

[0060] A method for calculating the deviation amounts ΔY and ΔZ that occur when the welding torch angle θ is changed will be described with reference to FIG. First, the torch angle adjustment mechanism 160 changes the welding torch angle θ to the first torch angle +θa, and then touch sensing is performed on the groove 10 to acquire groove shape information A1. Thereafter, the torch angle adjustment mechanism 160 changes the welding torch angle θ to the second torch angle −θb, and then touch sensing is performed on the groove 10 to acquire groove shape information A2. Next, as shown in FIG. 13, based on the groove shape information A1 and the groove shape information A2, the torch angle adjustment mechanism 160 calculates the deviation amounts ΔY and ΔZ of the welding wire tip 220 that occur when the welding torch angle θ is changed from the first torch angle +θa to the second torch angle −θb.

[0061] The control device 600 can correct the deviation amounts ΔY and ΔZ of the tip 220 of the welding wire by controlling the robot body 110 (movement mechanism) and moving the welding torch 200 in the Y-axis direction and the Z-axis direction by the deviation amounts ΔY and ΔZ of the tip 220 of the welding wire calculated by touch sensing.

[0062] It is also possible to continuously adjust the welding torch angle θ to any (desired) torch angle θi as needed while changing the welding torch angle θ from the first torch angle +θa to the second torch angle -θb. When adjusting the torch angle θi, the deviations Δyi and Δzi calculated using the following formulas are simultaneously used as the correction amounts for the Y and Z axes. Δyi=(θi-θ1) / (θ2-θ1)·ΔY····Formula (1) Δzi=(θi-θ1) / (θ2-θ1)·ΔZ····Formula (2)

[0063] The arbitrary torch angle θi does not have to be limited to the range between the first torch angle +θa and the second torch angle −θb.

[0064] (How to correct the torch angle while weaving a weld) The above-described torch angle correction step S106 can also be applied to a weaving method in which welding torch 200 is repeatedly moved back and forth in the width direction of groove 10 while performing welding work along the extension direction of groove 10 (weld line direction). When both ends of a welding pass are adjacent to groove walls 11 and 12, as in welding pass 1 and welding pass 2 in Figure 11, better welding can be achieved by adjusting the welding torch angle θ at both ends of the weaving to be appropriate for the nearby groove walls 11 and 12. To achieve this, in addition to weaving in the width direction (Y-axis direction) of the groove 10, it is necessary to change the welding torch angle θ during weaving.

[0065] 14 is a schematic diagram showing a weaving method involving a change in torch angle. In the example shown, for a weaving width Wy, the weaving is performed so that the first torch angle is +θa at the left edge of the paper and the second torch angle is -θb at the right edge of the paper.

[0066] At this time, welding robot 100 is instructed by control device 600 to vary the Y-axis, Z-axis, and welding torch angle θ as follows. Welding torch angle θ: First torch angle + θa←→ Second torch angle - θb Y axis (left and right direction of groove): ± (weaving width Wy + deviation amount 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. By using equations (1) and (2), the welding torch angle θ can be set to any torch angle θi between the first torch angle +θa and the second torch angle -θb.

[0067] Second Embodiment Next, a second embodiment of the torch angle adjustment mechanism 260 will be described with reference to FIGS. 15A to 15C, focusing on the differences from the above-described example. Figure 15A is a front view showing the torch angle adjustment mechanism of the second embodiment, Figure 15B is a side view showing the torch angle adjustment mechanism of the second embodiment, and Figure 15C is a rear view showing the torch angle adjustment mechanism of the second embodiment.

[0068] The torch angle adjustment mechanism 260 includes a slide support part 161 , a slide mechanism part 162 , a rotation mechanism part 163 , a drive motor 164 , a moving body 165 , and a transmission mechanism 270 . The torch angle adjustment mechanism 260 differs in configuration from the torch angle adjustment mechanism 160 of the first embodiment in that it adds a transmission mechanism 270 that transmits the driving force of the drive motor 164 to the sliding rotation shaft 281 of the rotation mechanism part 163, and omits the crank support part 166 that regulates the movement of the linear rail 188 of the rotation mechanism part 163.

[0069] The transmission mechanism 270 is arranged on the opposite side of the moving body 165 in the X-axis direction, sandwiched between the welding torch rotation drive unit 153, and has a drive pulley 271 that rotates integrally with a drive rotation shaft 278 driven by the output gear 176 of the drive motor 164, a driven pulley 272 that rotates integrally with a sliding rotation shaft 281 of the turning mechanism unit 163, and a timing belt 273 that is looped around the drive pulley 271 and the driven pulley 272 in a cross-looped state. As shown in FIG. 15B, drive rotation shaft 278 and sliding rotation shaft 2812 extending in the X-axis direction are also formed to protrude toward the opposite side of moving body 165 sandwiched between welding torch rotation drive part 153.

[0070] The driving force transmitted from the drive rotation shaft 278 to the sliding rotation shaft 2812 by the transmission mechanism 270 rotates the sliding part 186 integrally via the rotating arm part 197 and the support block 180 . As described above, torch angle adjustment mechanism 260 can change and adjust welding torch angle θ by simultaneously rotating welding torch 200 (welding torch rotation drive unit 153) and sliding welding torch 200 in the Y-axis direction along base rail 171 using the driving force of drive motor 164.

[0071] (Action and effect) Next, the operation of the torch angle adjustment mechanism 260 of the second embodiment will be described with reference to Figures 16 and 17. Figure 16 is a front view of the torch angle adjustment mechanism of the second embodiment, showing a first tilted state in which the welding torch is tilted to a first torch angle. Figure 17 is a front view of the torch angle adjustment mechanism of the second embodiment, showing a second tilted state in which the welding torch is tilted to a second torch angle. Note that Figures 16 and 17 only show the main components so that the operation of the torch angle adjustment mechanism 260 can be easily seen.

[0072] As shown in Figure 16, in the slide mechanism part 162 of the torch angle adjustment mechanism 260, as in the first embodiment, when the first gear 175 is driven to rotate in the forward direction (see 298a in Figure 16), the moving body 165 slides a predetermined distance a along the board rail 171 toward the robot main body 110 (see 298b in Figure 16).

[0073] 16, in the rotation mechanism unit 163 of the torch angle adjustment mechanism 260, when the drive pulley 271 is rotationally driven in the forward direction (see 298a in FIG. 16), the sliding rotation shaft 281 is rotationally driven to one side (see 298c in FIG. 16), and the sliding unit 186 rotates integrally via the rotating arm unit 197 and the support block 180. Accordingly, the sliding unit 186 slides relatively toward the upper side of the linear motion rail 188, causing the linear motion rail 188 to slide downward (see 298d in FIG. 16).

[0074] As a result, torch angle adjustment mechanism 260 rotates sliding portion 186 clockwise on the page about sliding rotation shaft 281 using the driving force of drive motor 164, while simultaneously moving linear rail 188 a predetermined distance q and sliding movable body 165 a predetermined distance a in the Y-axis direction toward robot body 110, thereby changing welding torch angle θ of welding torch 200 to first torch angle + θa while maintaining the position of tip 220 of the welding wire.

[0075] As shown in Figure 17, in the slide mechanism part 162 of the torch angle adjustment mechanism 260, as in the first embodiment, when the first gear 175 is driven to rotate in the reverse direction (see 299a in Figure 17), the movable body 165 slides a predetermined distance b along the board rail 171 to the opposite side of the robot body 110 (see 299b in Figure 17).

[0076] 17, in the rotation mechanism unit 163 of the torch angle adjustment mechanism 260, when the drive pulley 271 is rotationally driven in the reverse direction (see 299a in FIG. 17), the sliding rotation shaft 281 is rotationally driven to the other side (see 299c in FIG. 17), and the sliding unit 186 rotates integrally via the rotating arm unit 197 and the support block 180. Accordingly, the sliding unit 186 slides relatively toward the lower side of the linear motion rail 188, causing the linear motion rail 188 to slide upward (see 299d in FIG. 17).

[0077] As a result, the torch angle adjustment mechanism 260 rotates the sliding part 186 counterclockwise on the page about the sliding rotation shaft 281 by the driving force of the drive motor 164, and at the same time moves the linear rail 188 by a predetermined distance r and slides the movable body 165 by a predetermined distance b in the Y-axis direction away from the robot body 110, thereby changing the welding torch angle θ of the welding torch 200 to the second torch angle -θb while maintaining the position of the tip 220 of the welding wire.

[0078] 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 techniques, and these modifications and applications are included in the scope of protection sought.

[0079] As described above, the present specification discloses the following: (1) A portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, A welding torch, A robot body having a movement mechanism that moves the welding torch in the extension direction of the groove, the width direction of the groove, and the depth direction of the groove; a torch angle adjustment mechanism that changes the welding torch angle 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 the extending direction of the groove; Equipped with The torch angle adjustment mechanism includes a moving body that moves relative to the robot body along the width direction of the groove, a sliding part that is provided on the moving body and rotates around a sliding rotation axis that extends in the extension direction of the groove, a guide rail on which the sliding part slides, and a movable support body that is attached to the guide rail, supports the welding torch, and tilts with the rotation of the guide rail, and causes the sliding part to slide relative to the guide rail and rotates the guide rail and the sliding part around the sliding rotation axis. Portable welding robot. According to this configuration, there is no need for a guide member extending across the widthwise outer side of the groove, so the torch angle adjustment mechanism that changes the welding torch angle of the welding torch while maintaining the tip position of the welding wire can be made compact.

[0080] (2) The torch angle adjustment mechanism uses a single motor to move the moving body, slide the sliding part, and rotate the sliding part. A portable welding robot according to (1). According to this configuration, the number of parts in the torch angle adjustment mechanism can be reduced to make it smaller, and the welding torch angle can be changed by a single motor, which simplifies control.

[0081] (3) The guide rail is rotated around the sliding rotation shaft by a crank member that is swingable relative to the guide rail and the moving body. A portable welding robot according to (1) or (2). According to this configuration, the movable support portion can be supported by the crank member so that it can move in an arc shape centered on the target position of the welding wire, so that the welding torch angle can be changed accurately with a simple configuration.

[0082] (4) The sliding portion is connected to an angle adjustment pulley provided around the sliding rotation shaft via a connecting member, The sliding portion rotates via the angle adjustment pulley by a belt that is stretched between the angle adjustment pulley and a pulley that is provided around a drive shaft driven by a motor. A portable welding robot according to (1) or (2). According to this configuration, the movable support part can be supported so as to move in an arc shape centered on the target position of the welding wire without using a crank member, thereby reducing the number of parts and making the configuration simpler.

[0083] (5) A welding torch target position setting method using a portable welding robot according to any one of (1) to (4), which moves along the guide rail attached to the workpiece having the groove and welds the workpiece, A shape information acquisition process in which the groove is touch-sensed using the welding torch and shape information of the groove is calculated; a correlation position acquisition step of acquiring correlation position relationship data between the tip of the welding wire and the shape of the groove; a lamination design process for performing lamination design based on the groove shape information; 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; a welding torch angle setting process for setting a welding torch angle of the welding torch for each welding pass designed by the layered process; Equipped with How to set the welding torch's target position. According to this configuration, an appropriate welding torch angle can be set for each welding pass, thereby improving the quality of welding.

[0084] (6) The touch sensing is performed at a first torch angle obtained by changing the welding torch angle using the torch angle adjustment mechanism and at a second torch angle different from the first torch angle, and based on the acquired two pieces of correlation positional relationship data, a deviation amount 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 is calculated; 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 welding pass designed by the layered process and changing the welding torch to a desired torch angle by the torch angle adjustment mechanism; a welding torch angle correction process in which the deviation amount at the desired torch angle, which is calculated from the deviation amounts at the first torch angle and the second torch angle, is corrected by the movement mechanism; Further provided with (5) A method for setting a welding torch target position according to the present invention. According to this configuration, the error (deviation amount) caused by the change in the welding torch angle by the torch angle adjustment mechanism can be corrected, further improving the quality of welding. [Explanation of symbols]

[0085] 10 Bevel 11 Grooved wall 12 Grooved wall 13 Root 50 Welding System 100 Portable welding robot 110 Robot body 112 Movable body 120 guide rail 130 Torch connection part 132 Torch clamp 134 Torch clamp 150 Torch Approximation Linear Movement Mechanism 151 Sliding Table 151a long groove 152 Crank 153 Welding torch rotation drive unit 154 Rotational Axis 155 connecting pin 156 Fixing pin 160 Torch angle adjustment mechanism 161 Slide support 162 Slide mechanism 163 Rotation mechanism 164 Drive motor (motor) 164a Output shaft 165 Mobile 166 Crank support 167 Movable support part (movable support body) 171 PCB rail 172 Substrate sliding part 173 Rack support 174 Slide rack 175 First Gear 176 Output gear 177 Bevel gear 178 Drive shaft 179 Motor support plate 180 Support Block 181 Sliding Rotating Shaft 182 Sector gear 182a outer gear 182b Internal gear 183 First rotation axis 184 2nd Gear 185 3rd Gear 186 Sliding part 187 4th Gear 188 Linear rail (guide rail) 189 Rotating side rack 190 Movable body fixed part (movable support body) 191 Second rotation axis 192 Protruding Arm 193 Crank rotating shaft 194 Crank arm (crank component) 195 Hinge part 196 Connection section 197 Rotating arm 200 welding torch 210 nozzle 211 Welding Wire 212 chips 220 welding wire tip 260 Torch angle adjustment mechanism 270 Transmission Mechanism 271 Drive pulley 272 Driven pulley (angle adjustable pulley) 273 Timing Belt (Belt) 278 Drive shaft 281 Sliding Rotating Shaft 300 Feeding device 400 Welding Power Source 410 Power Cable 420 Conduit Tube 500 Shielding gas supply source 510 Gas Tube 600 control device 601 Data storage unit 602 Bevel shape information calculation unit 603 Welding condition acquisition unit 604 Control Unit 610 Robot control cable 620 Power supply control cable

Claims

1. A portable welding robot that moves along a guide rail attached to a workpiece having a groove and welds the workpiece, A welding torch, A robot body having a movement mechanism that moves the welding torch in the extension direction of the groove, the width direction of the groove, and the depth direction of the groove; a torch angle adjustment mechanism that changes the welding torch angle 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 the extending direction of the groove; Equipped with The torch angle adjustment mechanism includes a moving body that moves relative to the robot body along the width direction of the groove, a sliding part that is provided on the moving body and rotates around a sliding rotation axis that extends in the extension direction of the groove, a guide rail on which the sliding part slides, and a movable support body that is attached to the guide rail, supports the welding torch, and tilts with the rotation of the guide rail, and causes the sliding part to slide relative to the guide rail and rotates the guide rail and the sliding part around the sliding rotation axis. Portable welding robot.

2. the torch angle adjustment mechanism uses a single motor to move the moving body, slide the sliding part, and rotate the sliding part. The portable welding robot according to claim 1 .

3. The guide rail is rotated around the sliding rotation axis by a crank member that is swingable relative to the guide rail and the moving body. The portable welding robot according to claim 1 .

4. the sliding portion is connected to an angle adjustment pulley provided around the sliding rotation shaft via a connecting member, The sliding portion rotates via the angle adjustment pulley by a belt that is stretched between the angle adjustment pulley and a pulley that is provided around a drive shaft driven by a motor. The portable welding robot according to claim 1 .

5. 5. A welding torch target position setting method using a portable welding robot according to claim 1, wherein the portable welding robot moves along the guide rail attached to the workpiece having the groove and welds the workpiece, A shape information acquisition process in which the groove is touch-sensed using the welding torch and shape information of the groove is calculated; a correlation position acquisition step of acquiring correlation position relationship data between the tip of the welding wire and the shape of the groove; a lamination design process for performing lamination design based on the groove shape information; 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; a welding torch angle setting process for setting a welding torch angle of the welding torch for each welding pass designed by the layered process; Equipped with How to set the welding torch's target position.

6. the touch sensing is performed at a first torch angle obtained by changing the welding torch angle using the torch angle adjustment mechanism and at a second torch angle different from the first torch angle, and based on the acquired two pieces of correlated positional relationship data, a deviation amount 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 is calculated; 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 welding pass designed by the layered process and changing the welding torch to a desired torch angle by the torch angle adjustment mechanism; a welding torch angle correction process in which the deviation amount at the desired torch angle, which is calculated from the deviation amount at the first torch angle and the deviation amount at the second torch angle, is corrected by the movement mechanism; Further provided with The welding torch target position setting method according to claim 5.

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