JP5797089B2 - Chip removal tool and chip removal method - Google Patents

Description

  The present invention relates to a tip removal tool and a tip removal method for removing an electrode tip from a shank of a spot welding gun.

  In a body assembly line for automobiles and the like, automobile bodies are manufactured by combining various panels and performing spot welding. The welding robot is equipped with a welding gun having a pair of arm members, and an electrode tip is attached to the tip of the arm member extending from the welding gun. Then, by applying a large current in a short time while pressing the panel with a pair of electrode tips, the panel can be welded by resistance heat generation. Further, since the electrode tip is worn with use, periodic replacement work is required. In order to facilitate such an electrode tip exchange operation, an exchange tool used for manually exchanging the electrode tip has been developed (see, for example, Patent Document 1). Furthermore, in order to further simplify the replacement work, an exchange device that automatically replaces the electrode tip has been developed (see, for example, Patent Document 2).

JP-A-7-251274 JP 2004-114109 A

  However, the changer described in Patent Document 2 as well as the exchange tool described in Patent Document 1 have a complicated structure composed of many parts. In this manner, removing the electrode tip using a complicated exchange device or exchange tool is a factor that increases the cost of removing the electrode tip.

  An object of the present invention is to reduce the cost of removing an electrode tip.

The tip removal tool of the present invention includes a pair of electrode tips that sandwich a workpiece , an arm member that includes a shank to which the electrode tip is mounted, and an arm member that is separate from the arm member and is pressed against one surface of the workpiece. one and member, an actuator for driving the pressing member, used in a spot welding gun comprising, before carboxymethyl Yanku a chip removal tool removing the electrode tip, the tip surface facing the electrode tip A plate member having a pressure receiving surface facing the pressure member on the other side, engaging the plate member with a gap between the shank and the electrode chip, and pressing the pressure member against the plate member Thus, the thrust of the pressure member is transmitted to the electrode tip via the plate member, and the electrode chip is transferred from the shank. And wherein the removal of the flop.

  In the chip removal tool of the present invention, the plate member is movably attached to a support member.

  In the chip removal tool of the present invention, the plate member is formed using an elastic material and is fixed to a support member.

The chip removing method of the present invention includes a pair of electrode chips sandwiching a workpiece, an arm member having a shank to which the electrode chip is mounted, and an arm member that is separate from the arm member and pressed against one surface of the workpiece. one and member, an actuator for driving the pressing member, used in a spot welding gun comprising, a chip removal method from the prior carboxymethyl Yanku removing the electrode tip, the tip surface facing the electrode tip A plate engaging step of engaging a plate member having a pressure receiving surface facing the pressure member on the other side into a gap between the shank and the electrode chip, and pressing the pressure member against the plate member, The thrust of the pressure member is transmitted to the electrode tip through the plate member, and the electrode tip is removed from the shank. And-up removing process, characterized by having a.

  According to the present invention, the plate member provided on one side with the chip surface facing the electrode chip and the pressure receiving surface facing the pressure member on the other is engaged with the gap between the shank and the electrode chip. It becomes possible to transmit the thrust of the pressure member to the electrode tip via the plate member. Thereby, an electrode tip can be easily removed from a shank, and it becomes possible to reduce the removal cost of an electrode tip.

It is the schematic which shows a spot welding gun. It is explanatory drawing which shows the use condition of a spot welding gun. (a)-(c) is a side view, a top view, and a front view which show a part of sub pressure arm. (a)-(c) is explanatory drawing which shows the procedure of spot welding. It is explanatory drawing which shows the pressurization state of the workpiece | work by an electrode tip and a sub pressurization arm. (a)-(c) is explanatory drawing which shows the procedure of spot welding. It is explanatory drawing which shows the installation state of a chip | tip removal tool. (a) is sectional drawing which shows the internal structure of a chip removal tool, (b) is sectional drawing which shows a chip removal tool along the AA line of Fig.8 (a). (a)-(d) is explanatory drawing which shows the use procedure of a chip | tip removal tool. (a) And (b) is a perspective view which shows a shank, an electrode tip, an engagement plate, and a pressurization piece. (a)-(d) is explanatory drawing which shows the use procedure of a chip | tip removal tool. (a) And (b) is a perspective view which shows a shank, an electrode tip, an engagement plate, and a pressurization piece. (a) And (b) is a perspective view which shows the chip | tip removal tool which is other embodiment of this invention. (a) is a side view which shows the chip | tip removal tool which is other embodiment of this invention, (b) is a top view which shows a chip | tip removal tool from the arrow A direction of Fig.14 (a). (a)-(d) is explanatory drawing which shows the use procedure of a chip | tip removal tool.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing a spot welding gun 10. FIG. 2 is an explanatory view showing a usage state of the spot welding gun 10. As shown in FIGS. 1 and 2, the illustrated spot welding gun 10 is a so-called straight type C-type gun. The spot welding gun 10 includes a welding gun body 13 that is fixed to a robot arm 12 of a welding robot 11. A fixed gun arm 14 formed in a substantially U shape is fixed to the welding gun body 13. A shank 15 is fixed to the tip of the fixed gun arm 14, and an electrode tip 16 is attached to the tip of the shank 15. An actuator 17 incorporating a servo motor (not shown) is fixed to the welding gun body 13. The actuator 17 has a drive rod 18 that is driven back and forth. A movable gun arm 19 is fixed to the drive rod 18. A shank 20 is fixed to the tip of the movable gun arm 19, and an electrode tip 21 is attached to the tip of the shank 20. The electrode tips 16 and 21 of the gun arms 14 and 19 are arranged coaxially so as to face each other. The movable gun arm 19 is driven in a direction approaching the electrode tip 16 by extending the drive rod 18 of the actuator 17. On the other hand, by retracting the drive rod 18 of the actuator 17, the movable gun arm 19 is driven away from the electrode tip 16. Further, as shown in the enlarged portion of FIG. 1, tapered fitting convex portions 15 a and 20 a are formed at the tips of the shanks 15 and 20, and the fitting convex portions 15 a and 20 a are formed on the electrode chips 16 and 21. Tapered fitting recesses 16a and 21a corresponding to the above are formed. By fitting the fitting recesses 16a and 21a of the electrode tips 16 and 21 into the fitting protrusions 15a and 20a of the shank 15 and 20, the fitting protrusions 15a and 20a and the fitting recesses 16a and 21a are brought into close contact with each other. The electrode tips 16 and 21 can be fixed to the shanks 15 and 20.

  Further, an actuator 22 incorporating a servo motor (not shown) is fixed to the welding gun body 13. The actuator 22 has a drive rod 23 that is driven forward and backward, and an auxiliary pressure arm (pressure member) 24 is fixed to the drive rod 23. The sub pressure arm 24 includes a base portion 25 attached to the drive rod 23 and a pressure piece 27 connected to the base portion 25 via a connecting rod 26. Here, FIGS. 3A to 3C are a side view, a plan view, and a front view showing a part of the auxiliary pressure arm 24. 3B is a plan view showing the auxiliary pressure arm 24 from the direction of arrow A in FIG. 3A, and FIG. 3C is a plan view from the direction of arrow B in FIG. A front view showing the pressure arm 24 is shown. As shown in FIGS. 3A and 3B, the pressure piece 27 has a piece main body 28 cut out in an arc shape. The inner diameter of the cutout of the piece body 28 is formed larger than the outer diameter of the electrode tips 16 and 21 and the shanks 15 and 20. A pair of pressure surfaces 28 a projecting upward is formed at the upper end of the piece body 28, and a pair of pressure surfaces 28 b projecting downward are formed at the lower end of the piece body 28. An insulating member (not shown) is provided between the pressurizing piece 27 and the connecting rod 26, and the pressurizing piece 27 and the connecting rod 26 are electrically insulated.

  As shown in FIG. 2, a welding control panel 30 incorporating a computer or the like is installed in the vicinity of the welding robot 11. The pre-taught spot position information is transmitted to the welding robot 11 via the cable 31, and the welding robot 11 moves the spot welding gun 10 toward a predetermined spot position. In addition, welding condition information (pressurization time, energization time, holding time, energization current, etc.) set for each spot is transmitted to the spot welding gun 10 via the cable 32. Perform spot welding according to the welding conditions. At the time of spot welding, by driving the actuator 17, the workpiece W is sandwiched between the electrode tips 16, 21 and pressurized, and by driving the actuator 22, the workpiece W is pressurized by the auxiliary pressure arm 24. It will be in the state.

  Then, the procedure of spot welding is demonstrated. 4A to 4C are explanatory views showing the procedure of spot welding. As shown to Fig.4 (a), the workpiece | work W which is welding object is comprised by the three panels P1-P3. The panel P3 arranged at the upper side is formed thinner than the panel P1 arranged at the lower side and the panel P2 arranged at the center. In addition, the panel P3 that is a thin plate has lower rigidity than the panels P1 and P2 that are thick plates. In the following description, the panel P1 is described as a thick plate P1, the panel P2 as a thick plate P2, and the panel P3 as a thin plate P3. The thick plates P1 and P2 may have the same thickness or different thicknesses.

  The workpiece W is fixed on the jig by a clamping device (not shown). In order to perform spot welding on the workpiece W, as shown in FIG. 4A, the movable gun arm 19 moves away from the fixed gun arm 14, and a predetermined gap is provided between the electrode tips 16 and 21. Then, the robot arm 12 moves the spot welding gun 10 so as to place the workpiece W between the electrode tips 16 and 21. At this time, the robot arm 12 moves the spot welding gun 10 so that the electrode tip 16 contacts the surface of the thick plate P1. Moreover, the sub pressurization arm 24 provided with the pressurization piece 27 is arrange | positioned at the thin plate P3 side. That is, in the illustrated case, the actuator 22 is driven so that the sub-pressurizing arm 24 is disposed on the electrode chip 21 side facing the thin plate P3.

  Subsequently, as shown in FIG. 4B, the movable gun arm 19 moves in a direction approaching the fixed gun arm 14, and the workpiece W is sandwiched between the electrode tips 16 and 21. That is, the workpiece W is pressed from the thick plate P1 side by the electrode tip 16, and the workpiece W is pressed from the thin plate P3 side by the electrode tip 21. As a result, the main applied pressure FL is applied from the electrode tip 16 to the striking point position of the workpiece W, and the main applied pressure FU is applied from the electrode tip 21. Next, as shown in FIG. 4 (c), the actuator 22 moves the sub pressure arm 24 downward so that the pressure piece 27 of the sub pressure arm 24 is pressed against the surface of the thin plate P3 (one surface of the workpiece W). Press down.

  In this way, the impact point position of the workpiece W is pressurized with the main pressures FU and FL by the electrode tips 16 and 21, and the vicinity of the impact point position of the workpiece W is pressurized with the auxiliary pressure Fα by the auxiliary pressure arm 24. It will be in the state. Under this pressurized state, a large current is passed between the electrode tips 16 and 21 in a short time, and a nugget for joining the panels P1 to P3 is formed. When such spot welding is completed, as shown in FIG. 4A, the movable gun arm 19 and the auxiliary pressure arm 24 are again lifted upward, and the robot arm 12 moves the spot welding gun 10 toward the subsequent spot position. Move.

  Here, FIG. 5 is an explanatory view showing a pressure state of the workpiece W by the electrode tips 16 and 21 and the auxiliary pressure arm 24. As shown in FIG. 5, a main pressure FU is applied from the electrode tip 21 to the striking point position of the thin plate P3, and a main pressure FL is applied from the electrode tip 16 to the striking point position of the thick plate P1. Further, a sub pressurizing force Fα is applied from the sub pressurizing arm 24 to the vicinity of the striking point position of the thin plate P3. At this time, the main pressure FL applied from the electrode tip 16 to the thick plate P1 is the main pressure FU applied from the electrode tip 21 to the thin plate P3 and the sub pressure Fα applied from the pressure piece 27. (FL = FU + Fα). That is, the main pressure FU applied from the electrode tip 21 to the thin plate P3 is smaller than the main pressure FL applied from the electrode tip 16 to the thick plate P1.

  Here, if the main pressing force FU and the main pressing force FL are the same size, the thin plate P3 is more easily deformed than the thick plates P1 and P2, and therefore the joint α between the thin plate P3 and the thick plate P2. The contact area at is increased as compared with the contact area at the joint β between the thick plate P1 and the thick plate P2. That is, since the resistance of the joint portion α on the thin plate P3 side is lower than the resistance of the joint portion β on the thick plate P1 side, the amount of heat generated at the joint portion α is lower than the amount of heat generated at the joint portion β. However, it was difficult to obtain good welding quality because it was biased toward the thick plate P1 side. On the other hand, when the spot welding gun 10 provided with the auxiliary pressurizing arm 24 is used, the main pressing force FU can be lowered below the main pressing force FL, so that the contact area of the joint portion α on the thin plate P3 side is reduced. Can be reduced. As a result, the resistance of the joint α on the thin plate P3 side can be increased, and the amount of heat generated at the joint α can be increased, so that good welding quality can be obtained without the nugget being biased toward the thick plate P1. It becomes. Further, by adjusting the sub pressurizing force Fα of the sub pressurizing arm 24, the pressurizing difference between the main pressurizing pressures FU and FL can be adjusted, so that the main pressurizing pressures FU and FL can be controlled with high accuracy. It becomes possible. Furthermore, since the main pressure force FU, FL is not adjusted using the bending reaction force of the workpiece W, the main pressure force FU, FL can be adjusted without being affected by the rigidity of the panels P1 to P3. It has become. Further, since the thin plate P3 is pressed by the sub-pressurizing arm 24, the curved deformation of the thin plate P3 can be suppressed, and also from this point, it is possible to obtain good welding quality.

  In the above description, the thin plate P3 is disposed on the upper electrode chip 21 side. However, the thin plate P3 may be disposed on the lower electrode chip 16 side. 6A to 6C are explanatory views showing the procedure of spot welding. As shown to Fig.6 (a), the workpiece | work W which is a welding object reverses the workpiece W mentioned above up and down. Thus, when the thin plate P3 is disposed below the workpiece W, the actuator 22 moves the auxiliary pressure arm 24 so that the pressure piece 27 is positioned on the electrode chip 16 side facing the thin plate P3. Let Then, the robot arm 12 moves the spot welding gun 10 so as to place the workpiece W between the electrode tips 16 and 21. Subsequently, as shown in FIG. 6B, the movable gun arm 19 moves in a direction approaching the fixed gun arm 14, and the workpiece W is sandwiched between the electrode tips 16 and 21. That is, the workpiece W is pressed from the thin plate P3 side by the electrode tip 16, and the workpiece W is pressed from the thick plate P1 side by the electrode tip 21. As a result, the main applied pressure FL is applied from the electrode tip 16 to the striking point position of the workpiece W, and the main applied pressure FU is applied from the electrode tip 21. Next, as shown in FIG. 6 (c), the actuator 22 moves the sub pressure arm 24 upward so that the pressure piece 27 of the sub pressure arm 24 is pressed against the surface of the thin plate P3 (one surface of the workpiece W). Pull up. As described above, when the thin plate P3 is disposed below the work W, the main pressurizing force FL is lowered from the main pressurizing pressure FU by pushing up the work surface from below by the sub pressure arm 24. Thereby, it becomes possible to obtain good welding quality without biasing the nugget toward the thick plate P1.

  Subsequently, a chip removal tool 40 and a chip removal method according to an embodiment of the present invention will be described. FIG. 7 is an explanatory view showing an installation state of the chip removal tool 40. 8A is a cross-sectional view showing the internal structure of the chip removal tool 40, and FIG. 8B is a cross-sectional view showing the chip removal tool 40 along the line AA in FIG. 8A. is there. First, as shown in FIG. 7, the tip removal tool 40 is installed on the line side of the spot welding process. When the electrode tips 16 and 21 are removed using the tip removal tool 40, the spot welding gun 10 is moved to the vicinity of the tip removal tool 40 by driving the robot arm 12 in accordance with position information taught in advance. As shown in FIGS. 8A and 8B, the chip removal tool 40 supports an engagement plate (plate member) 42 having a notch 41 formed at the tip thereof, and the engagement plate 42 movably. And a stand (support member) 43. The stand 43 has a rectangular tube-shaped sleeve 45 fixed to the pedestal 44 and a slider 46 slidably accommodated in the sleeve 45. A spring member 47 that urges the slider 46 upward is assembled to one end of the slider 46, and a spring member 48 that urges the slider 46 downward is assembled to the other end of the slider 46. The base end portion of the engagement plate 42 is fixed to the slider 46. That is, the engagement plate 42 of the chip removal tool 40 is movable in the direction of arrow B according to the applied load. When no load is applied to the engagement plate 42, the engagement plate 42 is stationary at the position shown in FIG. Further, as shown in FIG. 8B, a U-shaped notch 41 is formed at the tip of the engagement plate 42. The width dimension of the notch 41 is formed larger than the outer diameter dimension of the fitting projections 15 a and 20 a of the shanks 15 and 20 and smaller than the outer dimension of the electrode tips 16 and 21. Moreover, the width dimension of the engagement plate 42 is formed wider than the space | interval of the pressurization surface 28a (28b). That is, the width dimension of the engagement plate 42 is formed to be a width dimension that can simultaneously contact the pair of pressure surfaces 28a (28b). Furthermore, the thickness dimension of the engagement plate 42 is formed thinner than the gap t between the shanks 15 and 20 and the electrode tips 16 and 21 (hereinafter referred to as the tip gap t).

  Next, a procedure for using the chip removal tool 40 (chip removal method) will be described. FIGS. 9A to 9D are explanatory views showing a procedure for using the tip removal tool 40. FIGS. 10A and 10B are perspective views showing the shank 20, the electrode tip 21, the engagement plate 42, and the pressure piece 27. FIG. When removing the electrode tip using the tip removal tool 40, the robot arm 12 performs spotting so that the tip gap t faces the notch 41 of the engagement plate 42 as shown in FIG. 9A. The welding gun 10 is positioned. Further, when the upper electrode tip 21 is removed, the actuator 22 is driven in advance so that the pressure piece 27 is disposed above the electrode tip 21. Subsequently, as shown in FIGS. 9B and 10A, the spot welding gun 10 is moved in the horizontal direction by the robot arm 12, and the engagement plate 42 and the tip gap t are engaged (plate engagement). Joint process). That is, by inserting the fitting convex portion 20 a of the shank 20 into the notch 41 of the engagement plate 42, the end surface of the electrode chip 21 is opposed to the lower surface 42 a of the engagement plate 42. The pressing surface 28b of the pressing piece 27 faces the upper surface 42b. At this time, the lower surface 42a of the engagement plate 42 functions as a chip surface, and the upper surface 42b of the engagement plate 42 functions as a pressure receiving surface. Then, as shown in FIGS. 9C, 9D, and 10B, the actuator 22 is driven to lower the sub pressure arm 24, whereby the thrust of the sub pressure arm 24 is engaged. It is transmitted to the electrode tip 21 through the plate 42, and the electrode tip 21 is removed from the shank 20 (tip removal step). 9D, when the electrode tip 21 is removed from the shank 20, the engagement plate 42 moves downward together with the auxiliary pressure arm 24. The downward movement of 24 is not hindered.

  Next, a procedure for removing the lower electrode tip 16 will be described. FIGS. 11A to 11D are explanatory views showing the procedure for using the tip removal tool 40. 12A and 12B are perspective views showing the shank 15, the electrode tip 16, the engagement plate 42, and the pressure piece 27. FIG. When the electrode tip 16 is removed using the tip removal tool 40, first, as shown in FIG. 11A, the robot arm 12 is set so that the tip gap t faces the notch 41 of the engagement plate. As a result, the spot welding gun 10 is positioned. When the lower electrode tip 16 is removed, the actuator 22 is driven in advance so that the pressure piece 27 is disposed below the electrode tip 16. Subsequently, as shown in FIGS. 11B and 12A, the spot welding gun 10 is moved in the horizontal direction by the robot arm 12, and the engagement plate 42 and the tip gap t are engaged (plate engagement). Joint process). That is, when the fitting convex portion 15a of the shank 15 is inserted into the notch 41 of the engagement plate 42, the end surface of the electrode chip 16 is opposed to the upper surface 42b of the engagement plate 42. The pressing surface 28a of the pressing piece 27 faces the lower surface 42a of 42. At this time, the upper surface 42b of the engagement plate 42 functions as a chip surface, and the lower surface 42a of the engagement plate 42 functions as a pressure receiving surface. 11 (c), 11 (d), and 12 (b), the actuator 22 is driven to lower the sub pressure arm 24 so that the thrust of the sub pressure arm 24 is engaged. It is transmitted to the electrode tip 16 through the plate 42, and the electrode tip 16 is removed from the shank 15 (tip removal step). Further, as shown in FIG. 11D, when the electrode tip 16 is removed from the shank 15, the engagement plate 42 moves upward together with the auxiliary pressure arm 24, so that the auxiliary pressure arm 24 moves upward. The engagement plate 42 is not obstructed.

  As described above, since the engagement plate 42 is engaged with the tip gap t, the thrust of the auxiliary pressure arm 24 can be transmitted to the electrode tips 16 and 21, and the shank 15 and 20 can transmit the electrode. The chips 16 and 21 can be removed. Thereby, the power source for removing the electrode tips 16 and 21 can be omitted from the tip removal tool 40, and the tip removal tool 40 can be simplified. In this way, by simplifying the tip removal tool 40, it is possible to reduce the removal cost of the electrode tips 16, 21. Moreover, since the spot welding gun 10 can be moved using the robot arm 12 and the electrode tips 16 and 21 can be removed using the actuator 22, the removal operation of the electrode tips 16 and 21 can be automated. . As described above, it is possible to reduce the cost of removing the electrode tips 16 and 21 by automating the removal operation.

  In the above description, the tip removal tool 40 is configured by attaching the engagement plate 42 to the stand 43. However, the present invention is not limited to this, and the tip removal tool may be configured only by the engagement plate 42. . Here, FIGS. 13A and 13B are perspective views showing a tip removal tool 50 according to another embodiment of the present invention. In FIG. 13, members similar to those shown in FIGS. 10 and 12 are given the same reference numerals and description thereof is omitted.

  As shown in FIGS. 13A and 13B, the chip removal tool 50 is constituted by a single engagement plate 51. The engagement plate 51 is formed with the same notch 41 as the engagement plate 42 described above. When such a chip removal tool 50 is used, the operator inserts the engagement plate 51 into the chip gap t and drives the auxiliary pressure arm 24. Thus, when manually removing the electrode tips 16 and 21, it is desirable to operate the actuator 22 of the spot welding gun 10 independently in order to ensure safety in the removal operation. That is, it is desirable to operate the actuator 22 in a state where a safety plug (not shown) surrounding the welding robot 11 is removed, that is, in a state where the welding robot 11 and the spot welding gun 10 are completely stopped. In this case, as shown by a dotted line in FIG. 1, the actuator 22 is provided with a raising button 52, a lowering button 53, and the like that function in a state where the safety plug is removed. After being inserted into t, the operator manually operates the up button 52 and the down button 53. Thereby, the pressure piece 27 of the sub pressure arm 24 can be pressed against the engagement plate 51, and the electrode tips 16, 21 can be easily removed from the shanks 15, 20. In the case shown in FIG. 13A, the lower surface 51a of the engagement plate 51 functions as a tip surface, and the upper surface 51b of the engagement plate 51 functions as a pressure receiving surface. 13B, the lower surface 51a of the engagement plate 51 functions as a pressure receiving surface, and the upper surface 51b of the engagement plate 51 functions as a chip surface.

  In the above description, the tip removal tool 40 is configured by movably attaching the engagement plate 42 to the stand 43. However, the present invention is not limited to this, and the engagement plate 42 is fixed to the stand 43. May be. Here, FIG. 14 (a) is a side view showing a tip removal tool 60 according to another embodiment of the present invention, and FIG. 14 (b) shows the tip removal tool 60 from the direction of arrow A in FIG. 14 (a). FIG. FIGS. 15A to 15D are explanatory views showing a procedure for using the tip removal tool 60 (tip removal method). 14 and 15, members similar to those shown in FIGS. 8 and 9 are given the same reference numerals and description thereof is omitted.

  As shown in FIGS. 14A and 14B, the tip removal tool 60 has an engagement plate (plate member) 61 in which a notch 41 is formed at the tip, and a base end portion of the engagement plate 61 fixed. And a stand (support member) 62. The engagement plate 61 is formed using an elastic material such as spring steel, and the distal end portion of the engagement plate 61 is freely displaceable in the arrow B direction according to the applied load. When removing the electrode tip 21 using such a tip removal tool 60, first, as shown in FIG. 15A, the tip gap t is opposed to the notch 41 of the engagement plate 61. The spot welding gun 10 is positioned by the robot arm 12. Further, when the upper electrode tip 21 is removed, the actuator 22 is driven in advance so that the pressure piece 27 is disposed above the electrode tip 21. Subsequently, as shown in FIG. 15B, the spot welding gun 10 is moved in the horizontal direction by the robot arm 12, and the engagement plate 61 and the tip gap t are engaged (plate engagement step). That is, when the fitting protrusion 20a of the shank 20 is inserted into the notch 41 of the engagement plate 61, the end surface of the electrode chip 21 is opposed to the lower surface 61a of the engagement plate 61. The pressure surface 28 b of the pressure piece 27 faces the upper surface 61 b of 61. At this time, the lower surface 61a of the engagement plate 61 functions as a chip surface, and the upper surface 61b of the engagement plate 61 functions as a pressure receiving surface. Then, as shown in FIGS. 15C and 15D, the actuator 22 is driven to lower the sub pressure arm 24, so that the thrust of the sub pressure arm 24 is transmitted through the engagement plate 61 to the electrode tip 21. , And the electrode tip is removed from the shank (chip removal step). Further, as shown in FIG. 9 (d), when the electrode tip 21 is removed from the shank 20, the distal end portion of the engagement plate 61 is displaced downward together with the secondary pressure arm 24, so The downward movement of the pressure arm 24 is not hindered.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, although spring steel is mentioned as an example of the elastic material used when forming the engagement plate 61, it is not restricted to this. Any material may be used as the elastic material as long as it can be elastically deformed by the stroke of the pressure piece 27 necessary for removing the electrode tip. Although the engagement plate 61 is fixed to the stand 62, the present invention is not limited to this, and the engagement plate 61 is attached to the stand 62 in the same manner as the chip removal tool 40 shown in FIG. You may attach it freely.

  The spot welding gun 10 shown in the figure is a straight type C-type gun, but is not limited to this. When removing an electrode tip attached to a cam groove type C-type gun that swings a movable gun arm, the spot welding gun 10 is not limited thereto. The invention may be applied. Further, the present invention may be applied when removing an electrode tip attached to an X arm gun that swings a pair of gun arms, and is attached to a linear X gun that moves a pair of gun arms in parallel. The present invention may be applied when removing the electrode tip.

  In the above description, an electric servo motor is incorporated in the actuators 17 and 22. However, the present invention is not limited to this, and an actuator driven by hydraulic pressure or air pressure may be used. In the above description, the pressure piece 27 is pressed against the work surface after the work W is sandwiched between the electrode tips 16 and 21, but the present invention is not limited to this, and the pressure piece 27 is pressed against the work surface. After that, the workpiece W may be sandwiched between the electrode tips 16 and 21. Further, at the same timing, the workpiece W may be sandwiched between the electrode tips 16 and 21, and the pressure piece 27 may be pressed against the workpiece surface.

  In the above description, the workpiece W composed of three panels P1 to P3 is a welding target, but the present invention is not limited to this, and a workpiece composed of four or more panels may be the welding target. Furthermore, in the above description, the workpiece W composed of the panels P1 to P3 having different plate thicknesses is the welding target, but the present invention is not limited to this, and the workpiece composed of the panels having the same plate thickness may be the welding target. That is, when panels having different electrical resistances as physical property values are combined even if they have the same thickness, it is difficult to ensure the welding quality because the calorific value is different. By using the main pressurizing pressures FU and FL to be different from each other, appropriate welding quality can be obtained.

10 Spot welding gun 15 Shank 16 Electrode tip 20 Shank 21 Electrode tip 22 Actuator 24 Sub pressurizing arm (pressurizing member)
40 Chip removal tool 42 Engagement plate (plate member)
42a bottom surface (chip surface, pressure receiving surface)
42b Upper surface (pressure-receiving surface, chip surface)
43 Stand (support member)
50 Chip removal tool 51 Engagement plate (plate member)
51a Bottom surface (chip surface, pressure receiving surface)
51b Upper surface (pressure-receiving surface, chip surface)
60 Chip removal tool 61 Engagement plate (plate member)
61a Bottom surface (chip surface, pressure receiving surface)
61b Upper surface (pressure-receiving surface, chip surface)
62 Stand (support member)
t Tip gap (gap)
W Work

Claims (4)

A pair of electrode tips that sandwich the workpiece, an arm member that includes a shank to which the electrode tip is mounted, a pressure member that is separate from the arm member and is pressed against one surface of the workpiece, and the pressure member an actuator for driving a used spot welding gun comprising, a chip removal tool removing the electrode tip before carboxymethyl Yanku,
A plate member provided on one side with a chip surface facing the electrode chip, and a pressure receiving surface on the other side facing the pressure member;
By engaging the plate member in the gap between the shank and the electrode tip and pressing the pressure member against the plate member, the thrust of the pressure member is transmitted to the electrode tip via the plate member. A tip removing tool for removing the electrode tip from the shank. The tip removal tool according to claim 1,
The chip removing tool, wherein the plate member is movably attached to a support member. The tip removal tool according to claim 1,
The chip member is formed using an elastic material and fixed to a support member. A pair of electrode tips that sandwich the workpiece, an arm member that includes a shank to which the electrode tip is mounted, a pressure member that is separate from the arm member and is pressed against one surface of the workpiece, and the pressure member an actuator for driving a used spot welding gun comprising, a chip removal method from the prior carboxymethyl Yanku removing the electrode tip,
A plate engaging step of engaging a plate member provided on one side with a chip surface facing the electrode chip and having a pressure receiving surface facing the pressure member on the other in a gap between the shank and the electrode chip;
And wherein a, a chip remover step detaching the electrode tip from said pressure member pressed against the plate member, through the plate member to transmit the thrust of the pressure member to the electrode tip, said shank How to remove the tip.

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