Handy welding torch mounting structure

Abstract

A handy welding torch mounting structure (SK) is provided with: an attachment part (111) which is fixed to an arm (861) of a robot (86); a rectangular base plate (12) which is integrally formed with the attachment part (111) and on which a handy welding torch (7) is placed; a first side plate (13) which is supported on a first edge part (12a) of the base plate (12) so as to be capable of rotating in a direction of opening from a standing posture; and a second side plate (17) which is fixed to a second edge part (12b) facing the first edge part (12a) in the standing posture. The handy welding torch (7) is attached to the arm (861) by being sandwiched and held between the first side plate (13) made to stand in a state of being placed on the base plate (12) and the second side plate (17).

Description

Handy welding torch mounting structure

[0001] The present invention relates to a handheld welding torch mounting structure.

[0002] A technique for performing automatic welding by attaching a welding torch to the tip of an arm of an articulated robot is known, and is described in Patent Document 1.

[0003] Japanese Patent Application Publication No. 8-25274

[0004] There are welding torches known as handheld welding torches that can be held by a worker while welding. It would be useful to attach such handheld welding torches to the end of the arm of an articulated robot so that they can also be used for automatic welding. However, because handheld welding torches have a characteristic shape that allows them to be held by hand, it is currently difficult to attach them to the arm of a robot that repeatedly starts and stops its movement at high acceleration without causing rattle or other problems over a long period of time. Therefore, there is a need for a handheld welding torch attachment structure that can reliably attach a handheld welding torch to a robot's arm without rattle or misalignment.

[0005] A handheld welding torch mounting structure according to one embodiment of the present invention comprises an attachment portion fixed to the arm of a robot, a rectangular base plate formed integrally with the attachment portion and on which the handheld welding torch is placed, a first side plate supported on a first edge of the base plate so as to be rotatable in a direction opening from an upright position, and a second side plate fixed in an upright position to a second edge opposite the first edge, and the handheld welding torch is attached to the arm by being clamped and held between the first side plate and the second side plate which are upright while placed on the base plate.

[0006] In this embodiment, the handheld welding torch is sandwiched and held between the first and second side plates, allowing the handheld welding torch to be securely mounted without rattle or misalignment.

[0007] According to the handheld welding torch mounting structure of one aspect of the present invention, the handheld welding torch can be securely mounted on the arm of the robot without rattle or misalignment.

[0008] FIG. 1 is a schematic diagram showing an example of a usage form of a mounting structure SK for a handheld welding torch according to an embodiment of the present invention. FIG. 2A is a left side view of a torch 7. FIG. 2B is a front view of the torch 7. FIG. 3A is a left side view of a torch mounting unit 1. FIG. 3B is a right side view of the torch mounting unit 1. FIG. 3C is a front view of the torch mounting unit 1. FIG. 4A is a left side view showing the torch 7 mounted on the torch mounting unit 1. FIG. 4B is a right side view showing the torch 7 mounted on the torch mounting unit 1. FIG. 4C is a front view showing the torch 7 mounted on the torch mounting unit 1. FIG. 5A is a schematic left side view showing the force applied to the torch 7 by the torch mounting unit 1. FIG. 5B is a front view showing the force applied to the torch 7 by the torch mounting unit 1. FIG. 6 is a block diagram showing the configuration of the torch 7 and torch control unit 62. FIG. 7 is a left side view for explaining a modified torch mounting unit 1A.

[0009] The torch mounting unit 1 equipped with the handheld welding torch mounting structure SK according to an embodiment of the present invention will now be described. The torch mounting unit 1 is attached to the arm of an articulated robot 86 in a laser welding room 8ST, for example, as shown in FIG.

[0010] 1 is a schematic diagram showing an articulated robot 86 equipped with a handheld welding torch 7 via a handheld welding torch mounting structure SK. The articulated robot 86 is housed in a laser welding room 8ST. The laser welding room 8ST is separated by a partition 81 having a door 811, preventing the laser beam from leaking to the outside. Hereinafter, the handheld welding torch 7 will also be referred to simply as the torch 7.

[0011] Inside the laser welding room 8ST, there are arranged a jig table 82, an input / output device 83, a control device 84, and an articulated robot 86. An operator 85 enters and exits through a door 811. A torch 7 is attached to the arm at the tip of the articulated robot 86 via a torch attachment part 1 equipped with a handheld welding torch attachment structure SK.

[0012] The control device 84 has a robot control unit 61, a torch control unit 62, and a laser oscillator 63. Workpieces to be welded (members to be welded) and the like are fixed to the jig table 82. The articulated robot 86 is a robot in which multiple arms are rotatably connected in series, and its operation is controlled by the robot control unit 61 provided in the control device 84.

[0013] Torch 7 is a so-called handheld welding torch that can be held by an operator 85, and is attached to the tip of the arm of an articulated robot 86 via a torch attachment part 1. The operation of torch 7 is controlled by a torch control part 62.

[0014] The torch control unit 62 and the robot control unit 61 respectively control the operation of the torch 7 and the articulated robot 86, and this control is linked by a coordination control unit (not shown). The coordination control unit outputs the control status of the torch control unit 62 and the robot control unit 61, as well as the operating status of the torch 7 and the articulated robot 86, to the input / output device 83. The input / output device 83 has, for example, a display as an output device and a keyboard or a touch panel mounted on the display as an input device.

[0015] 6, the torch control unit 62 includes a CPU (Central Processing Unit) 621, which is a central processing unit, a current detection unit 622, and a memory unit 623. The memory unit 623 stores a processing application AP, and the processing application AP provides a welding program for the workpieces to be welded placed on the jig table 82 to the torch control unit 62 and the robot control unit 61, causing the torch 7 and the articulated robot 86 to cooperate to perform welding.

[0016] (Torch 7) The torch 7 will be described with reference to Figures 2A and 2B. Figure 2A is a left side view of the torch 7. Figure 2B is a front view of the torch 7. In the following description, the up, down, left, right, front, and rear directions are defined as the directions indicated by arrows in each figure. These up, down, left, right, front, and rear directions are set for the convenience of explanation and do not limit the orientation of the torch 7 in its usage position or configuration.

[0017] The torch 7 can be held in one hand and emits a laser beam LS generated by a fiber laser from its tip. The torch 7 has a main body 71, a nozzle chuck 72, and a nozzle 73. A fiber cable 74 that supplies a laser beam output from a laser oscillator 63 is connected to the rear end of the main body 71. The laser beam supplied from the fiber cable 74 passes through an optical system (not shown) housed inside the main body 71 and is emitted to the outside from the tip of the nozzle 73 as a laser beam LS.

[0018] The main body 71 has a housing 711. The cross section of the housing 711 is formed into a flat, generally rectangular shape that is thin in the left-right direction (width direction) and long (tall) in the up-down direction. In the front-to-rear direction, the housing 711 has, from the rear side, a cable support portion 71 d, a grip portion 71 a, a protrusion 71 b, and a tip portion 71 c.

[0019] The cable support portion 71d is a portion to which the fiber cable 74 is connected, and the grip portion 71a is a portion formed with a thickness and cross-sectional shape that can be held in the hand. The protruding portion 71b has a mountain-shaped portion 71b1 that houses an optical system such as a mirror and protrudes upward in a triangular mountain shape. The mountain-shaped portion 71b1 is a portion that fits between the thumb and index finger when the grip portion 71a is held in the hand, stabilizing the grip.

[0020] The tip portion 71c is a portion that slopes downward toward the tip when the gripping portion 71a is in the position shown in Figure 2A, extending horizontally in the front-to-rear direction. A nozzle chuck portion 72 is provided at the tip of the tip portion 71c. The nozzle chuck portion 72 detachably fastens and attaches the nozzle 73 in a position extending in the same inclined direction as the tip portion 71c. The nozzle 73 is a rod-shaped member, and its tip is a carbon tip portion 731. A laser beam LS is emitted from the tip of the carbon tip portion 731.

[0021] A trigger knob 712 and a contact portion 713 are provided on the bottom surface of the housing 711. The trigger knob 712 is located at a position where the index finger can rest when the grip portion 71a is held by hand. When the laser beam LS is ready to be emitted, pulling the trigger knob 712 with the index finger so as to push it into the housing 711 causes the laser beam LS to be emitted, and when the index finger is released, the trigger knob 712 returns to its original position and emission of the laser beam LS stops. The contact portion 713 is a portion that is electrically connected to the carbon tip portion 731 of the nozzle 73 and is a portion that comes into contact with the rod 321 of the second solenoid 32, which will be described later. Non-slip pads 714 and 715 are attached, for example, to the upper portion of the grip portion 71a and the lower portion from the grip portion 71a to the protruding portion 71b, respectively.

[0022] As shown in FIG. 2B, the maximum width of the housing 711 in the left-right direction is the distance between the left and right outer surfaces of the anti-slip pad 715, and this is referred to as housing width W7.

[0023] (Torch Mounting Part 1) Next, the torch mounting part 1 will be described with reference to Figures 3A to 3C. Figure 3A is a left side view of the torch mounting part 1, Figure 3B is a right side view of the torch mounting part 1, and Figure 3C is a front view of the torch mounting part 1.

[0024] The articulated robot 86 has a distal arm 861 which is the most distal of the multiple arms. In Figures 3A to 3C, the distal arm 861 is described as extending in the vertical direction with its tip facing downward. An attachment 862 is attached to the tip of the distal arm 861. The attachment 862 is a member that enables a flat plate to be fixed to the distal arm 861 with a bolt. Hereinafter, the distal arm 861 will also be simply referred to as the arm 861.

[0025] The torch mounting section 1 includes an arm plate 11, a base plate 12, a first side plate 13, a side plate 14, a second side plate 17, a clamp plate 18, a bottom box section 15, and a rear box section 16. The arm plate 11 has a plate-shaped, horizontally oriented mounting section 111 at its upper end, and is a plate-like member that extends downward in the vertical and front-rear directions from the right edge of the mounting section 111. The mounting section 111 is fastened and fixed to the attachment 862 with bolts.

[0026] The base plate 12 is fixed to the left surface of the lower end of the arm plate 11 and is a plate-like member extending horizontally with its longitudinal axis in the front-to-rear direction. The base plate 12 is formed in a roughly rectangular shape when viewed from above. A flat front cushion 122 that protrudes forward is attached to the front end surface of the base plate 12. The front cushion 122 is formed of, for example, low-elasticity rubber.

[0027] The first side plate 13 is supported at the left edge 12a (see FIG. 3A) of the base plate 12 by a pair of pins 135 fixed to the base plate 12 so as to be rotatable about an axis CL13 extending horizontally in the front-to-rear direction (see arrow DR1 in FIG. 3C). The left edge 12a is the first edge in this example. In FIGS. 3A and 3C, the first side plate 13 is shown in an upright position. In the upright position, the first side plate 13 is formed in a shape that has a roughly rectangular rear side and a triangular protruding edge 13a on the front side.

[0028] A handle 131, a hook receiving portion 132, and a bolt 133 are attached to the outer surface of the first side plate 13. The handle 131 can be held by hand, and makes it easy to manually change the position of the torch mounting portion 1 when the torch mounting portion 1 is attached to the distal arm portion 861.

[0029] The hook receiving portion 132 is attached to the upper portion of the protruding edge portion 13a, and a hook portion 183 attached to the clamp plate 18 is hooked and locked onto the hook receiving portion 132. In other words, the hook receiving portion 132 and the hook portion 183 constitute a so-called snap lock 19.

[0030] The bolt 133 has a head 133a that can be grasped by hand and a shaft 133b formed with a male thread, and is threaded into the first side plate 13 so as to be movable back and forth in the left-right direction. The bolt 133 is, for example, a resin bolt made of resin. When the bolt 133 is tightened and threaded, the shaft 133b penetrates the first side plate 13 and protrudes inward. A first cushion 134 that is long in the front-to-rear direction is affixed to the lower part of the inner surface of the first side plate 13. The first cushion 134 is made of, for example, low-elasticity rubber. The side plate 14 is a plate-shaped member fixed to the base plate 12 in an orientation extending in the front-to-rear and up-to-down directions.

[0031] As shown in FIG. 3B , the second side plate 17 has substantially the same outer shape and size as the first side plate 13. The second side plate 17 is fixed to the right edge 12b of the arm plate 11 in an upright position extending vertically and longitudinally by a set screw (not shown). In this example, the right edge 12b is the second edge. A base 182a of a hinge 182 and a bolt 173 are attached to the outer surface of the second side plate 17. A clamp plate 18 is attached to a pivot portion 182b that pivots relative to the base 182a of the hinge 182. This allows the clamp plate 18 to pivot about an axis CL18 that follows the outer shape of the second side plate 17 of the hinge 182 (see arrow DR2 in FIG. 3C ).

[0032] The clamp plate 18 has a base 181 (see FIG. 3C ) and a pair of side portions, and has a flat U-shaped cross section. The distance between the inner surfaces of the pair of side portions is equal to the distance between the inner surfaces of the first side plate 13 and the second side plate 17 when the clamp plate 18 is in the upright position. The rotating portion 182 b of the hinge 182 is fixed to the outer surface of one of the pair of side portions of the clamp plate 18. A hook portion 183 is fixed to the outer surface of the other of the pair of side portions. The hook portion 183 is hooked onto and engaged with the hook receiving portion 132 of the first side plate 13. As a result, when the clamp plate 18 rotates clockwise about the axis CL18 as shown in FIG. 3C , the pair of side portions abut against the upper end surfaces of the first side plate 13 and the second side plate 17, respectively, and the hook portion 183 can be further hooked onto and fixed to the hook receiving portion 132. That is, the first side plate 13, the clamp plate 18, and the second side plate 17 can form an integrated gate-like shape when viewed from the front.

[0033] When the first side plate 13 is raised in parallel with the second side plate 17, the axis of the bolt 133 and the axis of the bolt 173 coincide with each other.

[0034] 3A , the bottom box portion 15 is a box-shaped portion attached to the underside of the base plate 12. A first solenoid 31 and a second solenoid 32 are housed and fixed inside the bottom box portion 15. The first solenoid 31 and the second solenoid 32 have rods 311 and 321 that move in and out independently under the control of the torch control unit 62.

[0035] The rear box section 16 is a box-shaped section connected to the rear of the bottom box section 15 in a state where it protrudes from the base plate 12. A limit switch 33 is housed and fixed inside the rear box section 16. A contact 331 of the limit switch 33 protrudes upward from the top surface of the rear box section 16. The limit switch 33 turns ON when the contact 331 is pressed downward. The limit switch 33 outputs a signal indicating ON to the torch control section 62.

[0036] 3C , in a state in which the first side plate 13 is raised parallel to the second side plate 17, the distance between the inner surfaces of the first side plate 13 and the second side plate 17 in the left-right direction is defined as distance Wa, and the distance between the inner surfaces of the first cushion 134 and the second cushion 174 in the left-right direction is defined as distance Wb. Distance Wa is greater than the housing width W7 of the torch 7 (see FIG. 2B ), and distance Wb is smaller than housing width W7.

[0037] Next, the attachment of the torch 7 to the torch attachment part 1 will be described with reference to Figures 4A to 4C. Figure 4A is a left side view showing the torch 7 attached to the torch attachment part 1. Figure 4B is a right side view showing the torch 7 attached to the torch attachment part 1. Figure 4C is a front view showing the torch 7 attached to the torch attachment part 1.

[0038] First, the clamp plate 18 of the torch mounting unit 1 is rotated counterclockwise to an open position as shown in Figures 3B and 3C. The first side plate 13 is also rotated clockwise to an open position as shown in Figure 3C. Then, the operator 85 places the torch 7 on the base plate 12 of the torch mounting unit 1 so that it faces the second side plate 17 from the upper left.

[0039] Because the first side plate 13 and the clamp plate 18 are open, the torch 7 can be easily placed on the base plate 12. More specifically, the anti-slip pad 715 on the right side of the torch 7 is pressed against the second cushion 174 of the second side plate 17, and the torch 7 is placed on the base plate 12 in a position where the inner surface 71c1 (see FIG. 2A) of the tip end 71c of the main body 71 abuts against the front cushion 122 attached to the front end of the base plate 12. At this time, the bottom surface of the cable support part 71d of the torch 7 presses the contactor 331 of the limit switch 33 in the rear box part 16, turning the limit switch 33 ON.

[0040] The rod 311 of the first solenoid 31 is in a retracted position spaced close to the trigger knob 712 of the torch 7. The rod 321 of the second solenoid 32 is in a retracted position spaced apart from the contact portion 713.

[0041] Once the torch 7 is placed on the base plate 12, the first side plate 13 is rotated counterclockwise in FIG. 3C to close it. That is, the first side plate 13 is placed in the upright position shown in FIGS. 4A to 4C. Next, the clamp plate 18 is closed, and the hook portion 183 is hooked onto the hook receiving portion 132 and locked. This causes the upper cushion 184 attached to the base 181 of the clamp plate 18 to press the upper surface of the protrusion 71b of the torch 7 diagonally downward and rearward. Furthermore, because the distance Wb between the first cushion 134 of the first side plate 13 and the second cushion 174 of the second side plate 17 is smaller than the housing width W7, they are elastically compressed, and the resulting repulsive force presses the main body 71 of the torch 7 between them, sandwiching it from the left and right.

[0042] On the other hand, because the distance Wa (see FIG. 3C ) is greater than the housing width W7, a gap is generated between the first side plate 13 and the second side plate 17 and the housing 711. In response to this, the operator 85 tightens the bolts 133 and 173, threading the shafts 133 b and 173 b, respectively, and tightening them so as to press the housing 711 from the left and right. As a result, both the lower and upper parts of the torch 7 are pressed against the first side plate 13 and the second side plate 17 from the left and right, preventing rattling or misalignment in the left and right direction. Furthermore, by using resin bolts for the bolts 133 and 173, the housing 711 is less likely to be scratched.

[0043] As described above, the torch 7 is placed on the base plate 12 with the first side plate 13 and the clamp plate 18 open, and the first side plate 13 is raised (closed), and the clamp plate 18 is closed and the snap lock 19 is locked, thereby securely attaching the torch 7 to the torch attachment portion 1.

[0044] 5A and 5B, the force applied to the torch 7 when the torch 7 is attached to the torch attachment part 1 will be described. Fig. 5A is a schematic left side view showing the force applied to the torch 7 by the torch attachment part 1. Fig. 5B is a front view showing the force applied to the torch 7 by the torch attachment part 1.

[0045] 5A schematically shows forces acting in the up-down and front-rear directions on the torch 7. The torch 7 is in contact with the upper cushion 184 attached to the clamp plate 18, the base plate 12, and the front cushion 122 attached to the base plate 12. The torch 7's own weight Fg due to gravity acts on its center of gravity G.

[0046] In this state, the upper cushion 184 applies a force F1 to the torch 7 in a downward, rearward direction perpendicular to the inclination direction of the protrusion 71b. The force F1 is resolved into a downward component force F1v and a rearward component force F1h. The front cushion 122 applies a forward force F2 as a reaction force to the rearward component force F1h, thereby balancing the torch 7. The base plate 12 applies an upward force F3 as a reaction force to the resultant force of the downward component force F1v and its own weight Fg, thereby balancing the torch 7.

[0047] 5A, the forces acting on the torch 7 in the front-rear and up-down directions are balanced. Furthermore, the front-rear and left-right movement (linear movement) and rotation of the torch 7 due to the application of an unintended external force are restricted by the upper cushion 184, the front cushion 122, and the base plate 12. Therefore, the torch 7 does not substantially rattle or shift in position relative to the torch mounting part 1 in the front-rear and up-down directions.

[0048] 5B schematically shows left-right forces acting on the torch 7. The torch 7 is subjected to a rightward force F23, which is the compressive repulsive force of the first cushion 134 of the first side plate 13, and a leftward force F24, which is the compressive repulsive force of the second cushion 174 of the second side plate 17. Meanwhile, at the upper part, a rightward force F21 due to the tightening of the bolt 133 and a leftward force F22 due to the tightening of the bolt 173 are applied.

[0049] Forces F21 and F22 are concentric clamping forces acting in opposite directions on the torch 7, and therefore naturally balance out. Forces F23 and F24 also self-adjust and balance out so that the compression of the first cushion 134 and the second cushion 174 is uniform. Therefore, the lateral forces acting on the torch 7 are concentric and balanced, and the torch 7 does not move (linearly) in the lateral direction relative to the torch mounting part 1, nor does it rotate. Even if an unintended lateral external force is applied to the torch 7, the torch 7 is clamped in the lateral direction at both the lower and upper portions, so linear movement and rotation are restricted. Therefore, the torch 7 does not substantially rattle or shift in the lateral direction relative to the torch mounting part 1.

[0050] In this way, the forces acting on torch 7 in all directions are balanced, and linear movement and rotation are restricted even in response to unintended external forces, so torch 7 does not move in any direction or rotate after being attached to torch attachment part 1. Therefore, torch attachment part 1 having handy welding torch attachment structure SK can reliably attach torch 7 to distal arm 861 of articulated robot 86 without rattle or misalignment.

[0051] The laser beam LS is emitted in the state where the torch 7 is attached to the torch attachment part 1 according to the following procedure. As shown in Fig. 6, signals from the limit switch 33 and the door switch 812 are input to the torch control part 62.

[0052] Torch control unit 62 prohibits emission of laser beam LS under all circumstances when it determines that door 811 is open based on a signal indicating the open / closed state of door 811 input from door switch 812. When door 811 is closed and it determines that torch 7 is placed on torch mounting unit 1 based on a signal from limit switch 33, it operates second solenoid 32 to bring rod 321 into contact with contact portion 713 of torch 7, thereby establishing a conductive state.

[0053] The contact point 713 is electrically connected to the carbon tip 731 at the tip of the nozzle 73. The current detection unit 622 operates the second solenoid 32 to protrude the rod 321, and when the rod 321 comes into contact with the contact point 713 of the torch 7, starts monitoring whether or not there is electrical continuity between the rod 321 and the jig table 82.

[0054] If the workpieces to be welded are conductive materials such as iron, when the carbon tip portion 731 of the torch 7 comes into contact with the welding portion of the workpieces to be welded for welding, the contact portion 713, the carbon tip portion 731, the workpieces to be welded, and the jig table 82 become conductive, and the current detection portion 622 detects that they have changed from a non-conductive state to a conductive state.

[0055] When the energization detection unit 622 detects a conductive state, i.e., when contact between the nozzle 73 and the workpieces to be welded is detected, the CPU 621 immediately puts the laser oscillator 63 into a state where it can output a laser beam. When an emission start command is issued from the processing application AP in this state, the CPU 621 causes the first solenoid 31 to push out the rod 311, causing the rod 311 to push in the trigger knob 712. This causes the laser beam LS to be emitted from the tip of the nozzle 73 of the torch 7. Furthermore, when an emission stop command is issued from the processing application AP, the CPU 621 causes the first solenoid 31 to retract the rod 311, returning the trigger knob 712 to its original position. This stops emission of the laser beam LS from the tip of the nozzle 73.

[0056] This embodiment is not limited to the above-described configuration and procedure, and modifications may be made without departing from the spirit of the present invention.

[0057] The ON / OFF operation of the trigger knob 712, detection of contact of the tip of the nozzle 73 with the workpiece, and confirmation of attachment of the torch 7 to the torch attachment part 1 may be performed electronically. That is, a cable may be connected between the torch 7 and the torch control part 62 to enable signal transmission, and the laser beam LS may be emitted from the tip of the nozzle 73 in response to an emission signal from the torch control part 62, regardless of the operation of the trigger knob 712. Also, the continuity of the carbon tip part 731 may be directly detected without using the contact part 713, and attachment to the torch attachment part 1 may be confirmed by a sensor. In this case, the first solenoid 31, the second solenoid 32, and the limit switch 33 are not required in the torch attachment part 1.

[0058] Although the torch mounting unit 1 has been described as having a structure in which the first side plate 13 on the left side can be opened and closed and the second side plate 17 on the right side can be fixed in an upright position, the reverse is also possible. That is, instead of the structure shown in FIG. 5B in which the first side plate 13 can be opened and closed (see arrow DR5L) and the second side plate 17 is fixed to the base plate 12 with a lock bolt N2, for example, the second side plate 17 may be pivotally supported by a pin (not shown) so that it can be opened and closed as shown by arrow DR5R, and the first side plate 13 may be fixed with a lock bolt N1. In this case, the handle 131 (see FIG. 3C) may be attached to the openable side plate. In this way, the torch mounting unit 1 can be configured to facilitate operation according to the dominant hand of the operator 85. In this case, the left edge 12a becomes the second edge, and the right edge 12b becomes the first edge.

[0059] The first side panel 13, which opens and closes, may be locked in the upright position by a releasable locking mechanism (not shown). In this case, the snap lock 19 is not necessary, and the clamp plate 18 may not be provided, as shown in FIG. 5B. Without the clamp plate 18, the force restricting the movement of the torch 7 in the forward / backward and upward / downward directions is borne by frictional forces due to left / right forces F21 to F24. This is applicable when the mass of the torch 7 is relatively small and when the acceleration of the torch 7 caused by the operation of the articulated robot 86 is not excessively large.

[0060] The torch mounting unit 1 is not limited to a structure in which the first side plate 13 is opened and closed manually, but may be a modified torch mounting unit 1A in which opening and closing can be performed automatically. This will be described with reference to Fig. 7. Fig. 7 is a left side view illustrating the modified torch mounting unit 1A.

[0061] In the torch mounting section 1A, the side plate 13A, which opens and closes around an axis CL13A, is rotatably supported at its front by a pin 135 and has a long shaft 135A fixed to the side plate 13A at its rear. The shaft 135A extends along the axis CL13A, rotatably passes through the side plate 14A, and protrudes rearward. A gear 135b is attached to the rear end of the shaft 135A. A pinion Ma meshes with the gear 135b, and the pinion Ma is fixed to the drive shaft of a motor M, such as a step motor, whose operation is controlled by the control device 84. As a result, the side plate 13A is automatically opened and closed by the driving force of the motor M, whose operation is controlled by the control device 84. The drive source for opening and closing the side plate 13A is not limited to a motor. Furthermore, the power transmission method may be a structure that transmits power using a belt or link mechanism instead of gears. The articulated robot 86 does not have to have an articulated structure, and may be an articulated or single-joint robot.

[0062] As described above in detail, the mounting structure for the handheld welding torch in this embodiment comprises an attachment portion 111 fixed to the arm 861 of the robot 86, a rectangular base plate 12 formed integrally with the attachment portion 111 and on which the handheld welding torch 7 is placed, a first side plate 13 supported on a first edge of the base plate 12 so as to be rotatable in a direction opening from an upright position, and a second side plate 17 fixed in an upright position to a second edge opposite the first edge, and the handheld welding torch 7 is attached to the arm 861 by being clamped and held between the first side plate 13 and the second side plate 17, which are upright while placed on the base plate 12.

[0063] The handheld welding torch 7 is placed on the base plate 12 and is sandwiched and held between the first side plate 13 and the second side plate 17. Therefore, the movement of the handheld welding torch 7 is restricted from three sides. This allows the handheld welding torch 7 to be securely attached to the arm 861.

[0064] The handheld welding torch mounting structure may also include a clamp plate 18 that connects and fixes the first side plate 13 and the second side plate 17 together.

[0065] This allows the first side plate 13 and the second side plate 17 to be firmly integrated, and also makes it possible to press the handheld welding torch 7 from above using the clamp plate 18, so that the handheld welding torch 7 can be more firmly attached to the arm 861.

[0066] Furthermore, the first side plate 13 and the second side plate 17 may each have bolts 133, 173 that are threaded to tighten the clamped handheld welding torch 7.

[0067] This allows the handheld welding torch 7 to be clamped more firmly in the width direction, allowing the handheld welding torch 7 to be attached to the arm 861 more securely.

[0068] The bolts 133 and 173 may also be made of resin.

[0069] This makes it difficult for the clamped portion of the handheld welding torch 7 to be damaged.

[0070] DESCRIPTION OF SYMBOLS 1, 1A Torch mounting portion 11 Arm plate 111 Mounting portion 12 Base plate 12a Left edge portion 12b Right edge portion 122 Front cushion 13 First side plate 13A Side plate 13a Protruding edge portion 131 Handle 132 Hook receiving portion 133 Bolt 133a Head portion 133b Shaft portion 134 First cushion 135 Pin 135A Shaft 135b Gear 14, 14A Side plate 15 Bottom box portion 16 Rear box portion 17 Second side plate 173 Bolt 173b Shaft portion 174 Second cushion 18 Clamp plate 181 Base portion 182 Hinge 182a Base portion 182b Rotating portion 183 Hook portion 184 Upper cushion 19 Snap lock 31 First solenoid 311 Rod 32 Second solenoid 321 Rod 33 Limit switch 331 Contactor 61 Robot control unit 62 Torch control unit 621 CPU (Central Processing Unit) 622 Current detection unit 623 Memory unit 63 Laser oscillator 7 Torch (handheld welding torch) 71 Main body 71a Grip 71b Protrusion 71b1 Mountain-shaped portion 71c Tip 71c1 Surface 71d Cable support portion 711 Housing 712 Trigger knob 713 Contact portion 714, 715 Non-slip pad 72 Nozzle chuck portion 73 Nozzle 731 Carbon tip portion 74 Fiber cable 8ST Laser welding room 81 Partition 811 Door 812 Door switch 82 Jig table 83 Input / output device 84 Control device 85 Operator 86 Articulated robot 861 End arm 862 Attachment AP Processing application CL13, CL18, CL13A Axis Fg Weight F1 to F3, F21 to F24 Force F1h, F1v Component force G Center of gravity LS Laser beam M Motor Ma Pinion N1, N2 Lock bolt SK Handheld welding torch mounting structure Wa, Wb Distance W7 Housing width

Claims

1. A handheld welding torch attachment structure comprising: an attachment part fixed to the arm of a robot; a rectangular base plate formed integrally with the attachment part and on which a handheld welding torch is placed; a first side plate supported on a first edge of the base plate so as to be rotatable in a direction opening from an upright position; and a second side plate fixed in an upright position to a second edge opposite the first edge, wherein the handheld welding torch is attached to the arm by being clamped and held between the first side plate and the second side plate which are upright while placed on the base plate.

2. A handheld welding torch mounting structure according to claim 1, further comprising a clamp plate for connecting and fixing said first side plate and said second side plate.

3. A handheld welding torch mounting structure as claimed in claim 1 or claim 2, wherein each of the first side plate and the second side plate has a bolt which is screwed in to press the clamped handheld welding torch against the bolt.

4. A handheld welding torch mounting structure according to claim 3, wherein the bolt is a resin bolt.

Images