Electrode exchanging apparatus

Abstract

To efficiently execute exchanging and polishing of electrodes.SOLUTION: A controller 60 is configured to: move, to, a second position, a used electrode 5 removed from a welding torch 4 at a first position; drive a third cylinder 13; move a polishing unit 6 toward a gripping unit 2; bring a distal end of the used electrode 5 into contact with the polishing unit 6; then execute polishing of the used electrode 5 using the polishing unit 6; and insert the polished electrode 5 polished by the polishing unit 6 into the welding torch 4 at the second position using a fourth cylinder 14.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electrode replacement device. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 5-285654 (Patent Document 1) discloses a welding robot with a welding torch attached to the tip of an arm. The welding robot in Japanese Patent Laid-Open Publication No. 5-285654 (Patent Document 1) fixes an electrode to the tip of the welding torch and automatically replaces the electrode when it is worn out during welding work. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-285654 Summary of the Invention [Problem to be solved by the invention]

[0004] In the welding robot of Japanese Patent Laid-Open No. 5-285654 (Patent Document 1), separate electrode replacement jigs are provided, one for used electrodes and one for new electrodes. Multiple electrodes are set in each electrode replacement jig. In the welding robot of Japanese Patent Laid-Open No. 5-285654 (Patent Document 1), a grinding device for grinding used electrodes is disposed in a position separate from each electrode replacement jig.

[0005] However, in a device such as that disclosed in Patent Publication No. 5-285654 (Patent Document 1), a polishing device for polishing used electrodes is provided in a position separate from each electrode replacement jig in which multiple electrodes are set, making it difficult to smoothly replace and polish the electrodes.

[0006] The present disclosure has been made to solve the above problems, and its object is to provide an electrode replacement device that can efficiently replace and polish electrodes. [Means for solving the problem]

[0007] The present disclosure relates to an electrode replacement device for replacing an electrode installed at the tip of a welding torch, which includes a first electrode-holding cylinder capable of holding an electrode, a second electrode-moving cylinder capable of moving the electrode together with the first cylinder, a holding unit for holding the electrode released from the first cylinder, a grinding unit for grinding the electrode, a third grinding unit-moving cylinder for moving the grinding unit toward the holding unit, a fourth cylinder capable of inserting the electrode into the welding torch, and a control device. The control device grips the used electrode removed from the welding torch at the first position with the first cylinder, moves the gripped used electrode to the second position with the second cylinder, releases the first cylinder at the second position, grips the released used electrode with the gripping unit, drives the third cylinder, moves the grinding unit toward the gripping unit, brings the tip of the used electrode into contact with the grinding unit, grinds the used electrode using the grinding unit, and inserts the ground electrode ground by the grinding unit into the welding torch at the second position with the fourth cylinder. [Effects of the Invention]

[0008] According to the electrode replacement device of the present disclosure, a used electrode removed from a welding torch at a first position is moved to a second position, the tip of the used electrode is brought into contact with a grinding unit, and grinding is performed, and the ground electrode ground by the grinding unit is inserted into the welding torch at the second position. This makes it possible to grind the electrode during the electrode replacement process, and allows for efficient electrode replacement and grinding. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of the electrode replacement device according to the embodiment. [Figure 2] 2 is a perspective view of the electrode replacement device according to the embodiment, seen from the opposite direction to that of FIG. 1. FIG. [Figure 3] 10 is a flowchart showing an electrode replacement process. [Figure 4] FIG. 10 is a side view for explaining insertion of a ground electrode in the embodiment. [Figure 5] FIG. 10 is a side view illustrating the lowering of a fourth cylinder in the embodiment. [Figure 6] 10A and 10B are diagrams illustrating a gripping unit according to an embodiment. [Figure 7] FIG. 10 is a perspective view for explaining inspection of a ground electrode in the embodiment. [Figure 8] FIG. 10 is a perspective view for explaining a state in which a used electrode is moved to an electrode polishing point in the embodiment. [Figure 9] FIG. 4 is a perspective view illustrating a state in which a first cylinder is opened in the embodiment. [Figure 10] FIG. 10 is a perspective view for explaining a state in which a first cylinder is moved to an electrode release point in the embodiment. [Figure 11] 10 is a side view for explaining a state in which a used electrode is brought into contact with a pin at the tip end by driving a fourth cylinder in the embodiment. FIG. [Figure 12] 10 is a side view illustrating how a used electrode is gripped by a gripping unit according to an embodiment. FIG. [Figure 13] 10 is a side view illustrating the state in which the polishing unit in the embodiment comes into contact with the tip of the used electrode. FIG. [Figure 14] FIG. 10 is a perspective view illustrating a state in which the gripping unit is rotated in the embodiment. [Figure 15] FIG. 4 is a side view illustrating a state in which the abrasive belt is rotated in the embodiment. [Figure 16] 10 is a side view illustrating a state in which the polishing unit is retracted and the fourth cylinder is returned to its initial position in the embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0011] Fig. 1 is a perspective view of an electrode replacement device 100 according to an embodiment. Fig. 2 is a perspective view of the electrode replacement device 100 according to an embodiment, viewed from the opposite direction to that of Fig. 1. When the X-axis, Y-axis, and Z-axis are defined as shown in Fig. 1, the X-axis direction is the left-right direction of the electrode replacement device 100, the Y-axis direction is the front-rear direction of the electrode replacement device 100, and the Z-axis direction is the up-down direction of the electrode replacement device 100.

[0012] The electrode replacement device 100 is enclosed in a housing (not shown). The electrode replacement device 100 includes a first cylinder 11, a second cylinder 12, a third cylinder 13, a fourth cylinder 14, and a fifth cylinder 15, and a control device 60. The electrode replacement device 100 is a device for replacing and polishing electrodes 5 worn down by, for example, TIG (Tungsten Inert Gas) welding. In TIG welding, the tip of the electrode 5 wears down with repeated welding operations, making it necessary to replace the electrode 5 midway through welding. The tip of the electrode 5 gradually becomes rounded due to wear and is also worn down due to deposition adhering to the tip of the electrode 5 during welding. The electrode replacement device 100 efficiently and automatically replaces and polishes used electrodes 5.

[0013] Here, a welding torch 4 is attached to the tip of the robot arm 3 of the welding robot. The welding torch 4 has an electrode 5 fixed to the tip of the torch head extending from the torch body. In the welding torch 4, a welding wire passing through the inside of a wire guide installed near the torch body is paid out during welding. The electrode 5 is clamped inside the torch head by an electrode-holding cylinder. In TIG welding, an arc is generated between the tungsten electrode 5 and the base metal, and the generated heat melts and joins the base metal and welding wire.

[0014] A used electrode 5 worn during welding work is moved above the electrode replacement device 100 by the robot arm 3. The electrode replacement device 100 performs the work of replacing the used electrode 5 installed at the tip of the welding torch 4 with a ground electrode 5. Position P1 in FIG. 1 is the electrode release point where the used electrode 5 is released from the welding torch 4. Position P2, just before position P1, is the electrode insertion point where the ground electrode 5 is inserted into the tip of the welding torch 4.

[0015] The first cylinder 11 is an electrode gripping cylinder capable of gripping the electrode 5. The first cylinder 11 is a driving device that grips and releases the electrode 5 by moving in the left-right direction (X-axis direction). The second cylinder 12 is an electrode moving cylinder that can move the electrode 5 together with the first cylinder 11. The second cylinder 12 is a driving device that moves the electrode 5 together with the first cylinder 11 in the front-back direction (Y-axis direction).

[0016] The third cylinder 13 is a cylinder for moving the grinding unit 6, which will be described later, toward the gripping unit 2, which will be described later. The third cylinder 13 is a driving device that moves the grinding unit 6 in the front-to-back direction (Y-axis direction). The fourth cylinder 14 is a cylinder that can insert the electrode 5 into the welding torch 4. The fourth cylinder is a driving device that moves the electrode 5 in the up-and-down direction (Z-axis direction). Note that as the third cylinder 13 is driven, the fourth cylinder 14 moves in the front-to-back direction (Y-axis direction) together with the grinding unit 6.

[0017] The fifth cylinder 15 is a cylinder for releasing a clamp that is configured to be able to press down the holder 20 (clamp portion) of the gripping unit 2, which will be described later. The fifth cylinder 15 is a driving device that presses down the holder 20 (clamp portion) of the gripping unit 2 downward (negative direction of the Z axis). Fig. 2 shows a motor 54 used to operate the gripping unit 2 and a motor 55 used to operate the polishing unit 6.

[0018] The control device 60 includes a control unit 61 and a memory unit 62. The control device 60 is capable of communicating with each device, such as the first cylinder 11, the second cylinder 12, the third cylinder 13, the fourth cylinder 14, the fifth cylinder 15, and the motors 54 and 55, in order to control each device. The control device 60 is also capable of communicating with a control device separately provided on the robot side, which includes the robot arm 3 and the welding torch 4. The control device 60 controls the robot arm 3 and the welding torch 4 by communicating with the control device on the welding robot side.

[0019] The control unit 61 is a computing entity that controls each device by executing various programs. The control unit 61 is composed of a computer such as a processor. The processor may be, for example, a microcontroller, a central processing unit (CPU), or a microprocessing unit (MPU). The processor has the function of executing various processes by executing programs, but some or all of these functions may be implemented using dedicated hardware circuits such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). The term "processor" is not limited to processors in the narrow sense that execute processes using stored programs, such as a CPU or MPU, but may also include hardwired circuits such as an ASIC or FPGA. Therefore, the term "processor" can also be interpreted as processing circuitry whose processes are predefined by computer-readable code and / or hardwired circuits. The processor may be composed of a single chip or multiple chips. Furthermore, the processor and related processing circuits may be composed of multiple computers interconnected by wire or wirelessly via a local area network or a wireless network. The processor and associated processing circuitry may be configured as a cloud computer that performs computations remotely based on input data and outputs the results of the computations to other devices at remote locations.

[0020] The memory unit 62 provides a storage area for storing program code, work memory, etc. when the processor of the control unit 61 executes various programs. The memory unit 62 may be one or more non-transitory computer-readable media. Examples of the memory unit 62 include volatile memories such as dynamic random access memory (DRAM) and static random access memory (SRAM), and non-volatile memories such as read-only memory (ROM) and flash memory. The memory unit 62 may also be one or more computer-readable storage media. Examples of the memory unit 62 include storage devices such as hard disk drives (HDDs) and solid-state drives (SSDs). The control unit 61 controls each device by executing the programs stored in the memory unit 62.

[0021] Fig. 3 is a flowchart showing the electrode replacement process. The process of the flowchart in Fig. 3 is repeatedly called and executed as a subroutine from the main routine under the control of the control device 60. The process of the flowchart in Fig. 3 corresponds to Fig. 1 and Figs. 4 to 16. Below, the process of the flowchart will be explained in association with each figure.

[0022] First, in step S1 (hereinafter simply referred to as "S"), the control device 60 determines whether a certain time has elapsed since the start of welding. The certain time is a predetermined time that takes into consideration the wear of the electrode due to welding. Note that in S1, the control device 60 may determine that the electrode 5 has been worn out based on, in addition to the elapse of time, a change in the value of the welding current, information from a sensor capable of measuring the shape of the electrode 5, or the like.

[0023] If the control device 60 determines that a certain amount of time has not elapsed since the start of welding (NO in S1), the process returns to S1. If the control device 60 determines that a certain amount of time has elapsed since the start of welding (YES in S1), the process proceeds to S2. In the following description, the robot arm 3 and welding torch 4 on the welding robot side may be collectively referred to as the robot, and the electrode replacement device 100 may be referred to as the device.

[0024] The following steps S2 to S6 correspond to those shown in Figure 1. After a certain period of time has passed, control device 60 moves the robot to the electrode release point (position P1) (S2). At position P1, control device 60 opens an electrode-holding cylinder (not shown) included in welding torch 4 on the robot side (S3). As a result of the step S3, used electrode 5 falls from the tip of welding torch 4 at position P1 toward electrode replacement device 100 due to its own weight.

[0025] Next, the control device 60 closes the first cylinder 11 on the device side (S4). By the processing of S4, the used electrode 5 is held by the first cylinder 11, as shown in FIG. 1. Next, the control device 60 moves the robot upward (S5). By the processing of S5, the welding torch 4 and the used electrode 5 are completely separated. Next, the control device 60 moves the robot to the electrode insertion point (position P2) (S6). As shown in FIG. 1, position P2 is a position where the ground electrode 5 is waiting.

[0026] The following processes of S7 to S10 correspond to Figs. 4 to 6. Fig. 4 is a side view for explaining the insertion of the ground electrode 5 in the embodiment. Fig. 5 is a side view for explaining the descent of the fourth cylinder 14 in the embodiment. Fig. 6 is a view for explaining the gripping unit 2 in the embodiment.

[0027] The control device 60 drives the fifth cylinder 15 shown in FIG. 4 to press down the clamping part of the gripping unit 2, thereby releasing the polished electrode 5 (S7). Here, the configuration of the gripping unit 2 will be described with reference to FIG. 6. The gripping unit 2 is a unit that can grip the electrode 5 or release the gripped state of the electrode 5. As shown in FIG. 6, the gripping unit 2 includes a collet chuck 21, a holder 20, a support base 22, a rotating body 23, a base portion 24, a bearing portion 25, and an elastic member 26.

[0028] The collet chuck 21 can grip the outer peripheral surface of the electrode 5 extending in the Z-axis direction (up and down direction). The collet chuck 21 has a generally truncated cone shape that narrows downward. The collet chuck 21 has a plurality of slits (not shown). The slits are formed at intervals in the circumferential direction of the Z-axis. The collet chuck 21 has a shape in which the inner peripheral surface can be contracted in diameter when an external force is applied from the outer peripheral side. As a result, when an external force is applied from the outer peripheral side, the inner peripheral surface of the collet chuck 21 contracts in diameter, allowing the collet chuck 21 to grip the electrode 5. When the external force from the outer peripheral side is released, the collet chuck 21, with its inner peripheral surface contracted, can expand in diameter to its original outer diameter. As a result, when the external force from the outer peripheral side is released, the inner peripheral surface of the collet chuck 21 expands in diameter, allowing the collet chuck 21 to release its grip on the electrode 5.

[0029] Holder 20 functions as a clamping section that can press the outer circumferential surface of collet chuck 21 from a direction intersecting the Z-axis direction. Holder 20 has a shape formed by joining three cylinders whose diameters gradually decrease downward, and the inner circumferential surface of the second cylinder section can abut against the outer circumferential surface of collet chuck 21. Note that holder 20 may also have a shape without any steps.

[0030] Support base 22 holds the position of collet chuck 21 in the Z-axis direction. Elastic member 26 biases holder 20 from one direction along the Z-axis direction. Elastic member 26 is, for example, a spring. Note that elastic member 26 is not limited to a spring, and may be made of rubber or the like having the necessary elastic force.

[0031] Two rods 40 extending from the fifth cylinder 15 are disposed between the holder 20 and the support base 22. The control device 60 drives the fifth cylinder 15 to lower the rods 40 toward the upper surface of the holder 20 and bring the rods 40 into contact with the upper surface of the holder 20. The control device 60 presses down the upper surface of the holder 20, thereby separating the holder 20 from the collet chuck 21 against the biasing force of the elastic member 26. This causes the collet chuck 21 to release the electrode 5 from its grip.

[0032] The rotating body 23 can rotate the gripping unit 2 in the circumferential direction of the Z axis with the electrode 5 as the axis center. The rotating body 23 is, for example, a pulley. A belt 51, which will be described later, is wound around the rotating body 23. When the motor 54 rotates, the belt 51 is driven and the rotating body 23 rotates. The rotating body 23 has a shape in which a cylindrical portion protrudes downward from a main body portion.

[0033] The rotating body 23 has a recess 80 formed in the Z-axis direction. The recess 80 includes an upper recess 81 formed in the main body of the rotating body 23 and a lower recess 82 formed in the protruding portion. The upper recess 81 has a bottom 83 formed therein. The third-stage cylindrical portion of the holder 20 is housed in the lower recess 82 of the rotating body 23. The second-stage cylindrical portion of the holder 20 and the elastic member 26 are housed in the upper recess 81 of the rotating body 23. One end of the elastic member 26 abuts against the bottom 83, and the other end of the elastic member 26 abuts against the outer circumferential surface connecting the first-stage cylindrical portion of the holder 20 to the second-stage cylindrical portion.

[0034] The base portion 24 is fixed to the main body of the electrode replacement device 100 (not shown). A through hole capable of accommodating the electrode 5 and the rotor 23 is provided in the base portion 24. The bearing portion 25 is provided on the inner circumferential surface of the through hole of the base portion 24. The bearing portion 25 is connected to the outer circumferential surface of the protruding portion of the rotor 23.

[0035] The polishing unit 6 polishes the tip portion 5a of the used electrode 5 in a direction oblique to the axial direction of the used electrode 5. The tip portion 5a of the electrode 5 held by the holding unit 2 is polished by the polishing belt 65 of the polishing unit 6 while rotating in the circumferential direction of the Z axis as the rotor 23 rotates. As a result, the tip portion 5a of the electrode 5 is polished into a conical shape.

[0036] Returning to the flowchart of FIG. 3, the control device 60 raises the fourth cylinder 14 as shown in FIG. 4 and inserts the ground electrode 5 into the welding torch 4 at the electrode insertion point (position P2) (S8). The process of S8 is a process of driving the fourth cylinder 14 to push upward the tip portion 5a of the electrode that abuts on the upper surface of the pin 14a protruding from the fourth cylinder 14. Next, the control device 60 closes an electrode-holding cylinder (not shown) included in the welding torch 4 on the robot side (S9). The process of S9 fixes the ground electrode 5 to the welding torch 4. Next, the control device 60 lowers the fourth cylinder 14 as shown in FIG. 5 (S10). The process of S10 is a process of driving the fourth cylinder 14 to lower the pin 14a connected to the fourth cylinder 14.

[0037] The following steps S11 to S16 correspond to Fig. 7. Fig. 7 is a perspective view for explaining the inspection of the ground electrode 5 in the embodiment. As shown in Fig. 7, the electrode replacing device 100 includes a limit switch 31. The limit switch 31 is disposed at an electrode confirmation point (position P3) and is a sensor that can detect the presence or absence of the electrode 5 when the electrode 5 comes into contact with a movable part of the limit switch 31.

[0038] The control device 60 moves the robot to the electrode confirmation point (position P3) (S11). Next, the control device 60 checks the presence or absence of the electrode 5 using the limit switch 31 (S12). Through the processes of S11 to S12, the control device 60 checks whether the ground electrode 5 is properly inserted into the welding torch 4 using the limit switch 31 at position P3. If the electrode 5 is not detected by the limit switch 31, the control device 60 may notify the user by an alarm or the like that the electrode 5 is not present.

[0039] Next, the control device 60 moves the robot to the electrode height adjustment point (position P4) (S13). As shown in Fig. 7, the electrode replacement device 100 includes a height adjustment table 32. The height adjustment table 32 is a table for abutting the tip 5a of the electrode 5 against its upper surface to adjust the protrusion of the electrode 5. At position P4, the control device 60 opens an electrode-holding cylinder (not shown) included in the welding torch 4 on the robot side (S14).

[0040] Next, the control device 60 moves the robot up and down to adjust the electrode protrusion, and then grips the electrode 5 in the correct position (S15). In S15, the control device 60 may adjust the protrusion of the electrode 5 using a sensor (for example, a photosensor) that detects the length of the electrode. After adjusting the protrusion of the electrode 5, the control device 60 grips the electrode 5 in the correct position by closing an electrode gripping cylinder (not shown) included in the welding torch 4 on the robot side. Next, the control device 60 moves the robot to the welding process (S16).

[0041] The next process in S17 corresponds to FIG. 8. FIG. 8 is a perspective view illustrating the movement of the used electrode 5 to the electrode polishing point in this embodiment. As shown in FIG. 8, the control device 60 drives the second cylinder 12 to move the first cylinder 11 to the electrode polishing point (position P5) (S17). Position P5 is the same position as position P2. The control device 60 grips the used electrode 5 removed from the welding torch 4 at position P1 with the first cylinder 11 (processing in S4), and moves the gripped used electrode 5 to position P2 with the second cylinder 12 (processing in S17).

[0042] The next process in S18 corresponds to Fig. 9. Fig. 9 is a perspective view for explaining the state in which the first cylinder 11 is opened in the embodiment. As shown in Fig. 9, the control device 60 opens the first cylinder 11 (S18). By the process in S18, the used electrode 5 falls by its own weight.

[0043] The next process in S19 corresponds to Fig. 10. Fig. 10 is a perspective view for explaining the state in which the first cylinder 11 in this embodiment is moved to the electrode release point. As shown in Fig. 10, the control device 60 drives the second cylinder 12 to move the first cylinder 11 to the electrode release point (position P1) (S19). By the process in S19, the first cylinder 11 can wait at position P1 in a state in which it can receive the used electrode 5 from the robot.

[0044] The next process in S20 corresponds to Fig. 11. Fig. 11 is a side view for explaining how the fourth cylinder in this embodiment is driven to bring the used electrode 5 into contact with the pin 14a at the tip. As shown in Fig. 11, the control device 60 drives the fourth cylinder 14 to bring the used electrode 5 into contact with the pin 14a at the tip (S20). By the process in S20, the used electrode 5 is positioned at an appropriate position for polishing, which will be described later.

[0045] The next process in S21 corresponds to FIG. 12. FIG. 12 is a side view illustrating how a used electrode 5 is gripped by the gripping unit 2 in this embodiment. As shown in FIG. 12, the control device 60 drives the fifth cylinder 15 to grip the electrode 5 with the gripping unit 2 (S21). Through the process of S21, the used electrode 5 released from the first cylinder 11 at position P5 (the same as position P2) is gripped by the gripping unit 2. Specifically, the driving of the fifth cylinder 15 moves the two rods 40 extending from the fifth cylinder 15 upward. As a result, an external force is applied by the elastic member 26 from the outer periphery of the collet chuck 21 inside the gripping unit 2, causing the inner circumferential surface of the collet chuck 21 to contract in diameter, thereby gripping the electrode 5.

[0046] The next process in S22 corresponds to Fig. 13. Fig. 13 is a side view for explaining the state in which the polishing unit 6 in this embodiment comes into contact with the tip 5a of the used electrode 5. As shown in Fig. 13, the control device 60 drives the third cylinder 13 to bring the polishing unit 6 into contact with the tip 5a of the electrode 5 (S22). This brings the polishing belt 65 of the polishing unit 6 into contact with the tip 5a of the electrode 5.

[0047] The next process in S23 corresponds to Fig. 14 and Fig. 15. Fig. 14 is a perspective view for explaining how the gripping unit 2 is rotated in the embodiment. Fig. 15 is a side view for explaining how the abrasive belt 65 is rotated in the embodiment. The control device 60 rotates the gripping unit 2 and also rotates the abrasive belt 65 (S23).

[0048] 9, the electrode replacement device 100 includes a pulley 53, a motor 54 that drives the pulley 53, and a belt 51. The rotating body 23 of the gripping unit 2 is a pulley that rotatably transmits the driving force from the pulley 53 via the belt 51. In the processing of S23, the control device 60 rotates the rotating body 23 by driving the motor 54 to rotate the pulley 53, and rotates the used electrode 5 in a direction perpendicular to the axial direction of the used electrode 5.

[0049] The control device 60 drives the motor 55 shown in FIG. 2 to rotate the polishing belt 65 of the polishing unit 6. The polishing unit 6 polishes the tip portion 5a of the used electrode 5 in a direction oblique to the axial direction of the used electrode 5. The control device 60 can polish the tip portion 5a of the used electrode 5 into a conical shape by simultaneously operating the motor 54 and the motor 55 of the polishing unit 6. The control device 60 may change the rotation speed of the motor 55 in the polishing unit 6 and the angle at which the polishing belt 65 contacts the tip portion 5a depending on the type of electrode 5 and the welding details. The control device 60 may adjust the rotation speed of the motor 54 and change the rotation speed of the gripping unit 2 depending on the type of electrode 5 and the welding details.

[0050] The next process in S24 corresponds to Figure 16. Figure 16 is a side view for explaining how the polishing unit 6 is retracted and the fourth cylinder 14 is returned to its initial position in this embodiment. The control device 60 drives the third cylinder 13 to retract the polishing unit 6 and return the fourth cylinder to its initial position (S24). Next, the control device 60 returns the process from the subroutine to the main routine.

[0051] By the process of S24, the polishing unit 6 and the fourth cylinder 14 move forward. As a result, the polishing belt 65 of the polishing unit 6 moves away from the tip 5a of the polished electrode 5 and is positioned so that the tip 5a of the polished electrode 5 overlaps the upper surface of the pin 14a of the fourth cylinder 14. The position of the polished electrode 5 in Fig. 16 corresponds to the electrode insert point (position P2) shown in the processes of S6 to S8.

[0052] As described above, electrode replacement device 100 moves used electrode 5 removed from welding torch 4 at position P1 to position P2, brings tip 5a of used electrode 5 into contact with grinding unit 6, grinds the electrode 5 at the same position P2, and inserts the ground electrode 5 ground by grinding unit 6 into welding torch 4 at position P2. This makes it possible to grind the electrode 5 during the process of replacing the electrode 5, and allows for efficient replacement and grinding of the electrode 5.

[0053] <Summary> (1) The present disclosure relates to an electrode replacement device 100 for replacing an electrode 5 installed at the tip of a welding torch 4. The electrode replacement device 100 includes a first electrode-holding cylinder 11 capable of holding the electrode 5, a second electrode-moving cylinder 12 capable of moving the electrode 5 together with the first cylinder 11, a holding unit 2 that holds the electrode 5 released from the first cylinder 11, a polishing unit 6 that polishes the electrode 5, a third polishing unit-moving cylinder 13 that moves the polishing unit 6 toward the holding unit 2, a fourth cylinder 14 capable of inserting the electrode 5 into the welding torch 4, and a control device 60. The control device 60 grips the used electrode 5 removed from the welding torch 4 at the first position (position P1) with the first cylinder 11, moves the gripped used electrode 5 to the second position (position P2) with the second cylinder 12, releases the first cylinder 11 at the second position (position P2), grips the released used electrode 5 with the gripping unit 2, drives the third cylinder 13, moves the grinding unit 6 toward the gripping unit 2, brings the tip 5a of the used electrode 5 into contact with the grinding unit 6, grinds the used electrode 5 using the grinding unit 6, and inserts the ground electrode 5 ground by the grinding unit 6 into the welding torch 4 at the second position (position P2) with the fourth cylinder 14.

[0054] According to the electrode replacement device 100 of the present disclosure, the used electrode 5 removed from the welding torch 4 at the first position (position P1) is moved to the second position (position P2), the tip 5a of the used electrode 5 is brought into contact with the grinding unit 6, and then grinding is performed, and the ground electrode 5 ground by the grinding unit 6 is inserted into the welding torch 4 at the second position (position P2). This makes it possible to grind the electrode 5 during the process of replacing the electrode 5, and the replacement and grinding of the electrode 5 can be performed efficiently.

[0055] (2) The electrode replacement device 100 of (1) further includes a limit switch 31 that detects the presence or absence of the electrode 5. The control device 60 checks whether the ground electrode 5 is properly inserted into the welding torch 4 by the limit switch 31 at the third position (position P3).

[0056] According to the electrode replacement device 100 of the present disclosure, the presence or absence of the electrode 5 can be easily detected by the limit switch 31 having a simple structure.

[0057] (3) In the electrode replacement device 100 of (1) or (2), the holding unit 2 includes a clamp portion (holder 20) biased by an elastic member 26. The electrode replacement device 100 further includes a fifth cylinder 15 for releasing the clamp, which is configured to be able to press down the clamp portion (holder 20). The control device 60 drives the fifth cylinder 15 to release the electrode 5 from the holding unit 2.

[0058] According to the electrode replacement device 100 of the present disclosure, the electrode 5 can be easily released from the gripping unit 2 by driving the fifth cylinder.

[0059] (4) The electrode replacement device 100 of any one of (1) to (3) further includes a first pulley (pulley 53) and a motor 54 that drives the first pulley (pulley 53). The gripping unit 2 includes a second pulley (rotating body 23) that is rotatably arranged with the first pulley (pulley 53) via a belt 51. The control device 60 rotates the second pulley (rotating body 23) by driving the motor 54 to rotate the first pulley (pulley 53), thereby rotating the used electrode 5 in a direction perpendicular to the axial direction of the used electrode 5.

[0060] According to the electrode replacement device 100 of the present disclosure, the used electrode 5 can be rotated in a direction perpendicular to the axial direction of the used electrode 5 .

[0061] (5) In the electrode replacement device 100 of (4), the polishing unit 6 polishes the tip 5a of the used electrode 5 in a direction oblique to the axial direction of the used electrode 5. The control device 60 simultaneously operates the motor 54 and the polishing unit 6 to polish the tip 5a of the used electrode 5 into a conical shape.

[0062] According to the electrode replacement device 100 of the present disclosure, the motor 54 and the grinding unit 6 are operated simultaneously, so that the tip 5a of the electrode 5 can be ground into a conical shape.

[0063] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0064] 2 gripping unit, 3 robot arm, 4 welding torch, 5 electrode, 5a tip portion, 6 polishing unit, 11 first cylinder, 12 second cylinder, 13 third cylinder, 14 fourth cylinder, 14a pin, 15 fifth cylinder, 20 holder, 21 collet chuck, 22 support base, 23 rotating body, 24 base portion, 25 bearing portion, 26 elastic member, 31 limit switch, 32 adjustment base, 40 rod, 51 belt, 53 pulley, 54, 55 motor, 60 control device, 61 control unit, 62 memory unit, 65 polishing belt, 80 recess, 81 upper recess, 82 lower recess, 83 bottom portion, 100 electrode replacement device.

Claims

1. An electrode replacement device for replacing an electrode installed at the tip of a welding torch, a first cylinder for holding an electrode capable of holding an electrode; a second cylinder for moving the electrode, which is capable of moving the electrode together with the first cylinder; a gripping unit that grips the electrode released from the first cylinder; a polishing unit for polishing the electrode; a third cylinder for moving the polishing unit toward the gripping unit; a fourth cylinder capable of inserting an electrode into the welding torch; a control device; The control device a used electrode removed from the welding torch at a first position is gripped by the first cylinder, and the gripped used electrode is moved to a second position by the second cylinder; releasing the first cylinder at the second position and gripping the released used electrode with the gripping unit; driving the third cylinder to move the polishing unit toward the gripping unit; After the tip of the used electrode is brought into contact with the polishing unit, the used electrode is polished using the polishing unit; an electrode replacement device that inserts the ground electrode ground by the grinding unit into the welding torch at the second position using the fourth cylinder;

2. Further provided is a limit switch for detecting the presence or absence of an electrode; 2. The electrode changing device according to claim 1, wherein the control device confirms whether the ground electrode is properly inserted into the welding torch by the limit switch at a third position.

3. the gripping unit includes a clamp portion biased by an elastic member; the electrode replacement device further includes a fifth cylinder for clamp release configured to be able to press down the clamp portion, The electrode replacement device according to claim 1 or 2, wherein the control device releases the electrode from the gripping unit by driving the fifth cylinder.

4. A first pulley; a motor that drives the first pulley, the gripping unit includes a second pulley rotatably disposed with respect to the first pulley via a belt; 3. The electrode replacement device according to claim 1, wherein the control device rotates the second pulley by driving the motor to rotate the first pulley, thereby rotating the used electrode in a direction perpendicular to an axial direction of the used electrode.

5. the polishing unit polishes the tip portion of the used electrode in a direction oblique to an axial direction of the used electrode, 5. The electrode replacing device according to claim 4, wherein the control device simultaneously operates the motor and the polishing unit to polish the tip of the used electrode into a conical shape.

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