JP3147731U - Electrodes for interchangeable electrical resistance spot welders - Google Patents

Abstract

An electrode for an electric resistance spot welding machine of an exchange type, in which an exchange electrode does not fall off during welding.
A bottomed cylindrical exchange electrode 2 whose upper surface is a contact surface 2a with a member to be welded, and an electrode body to which the exchange electrode 2 is attached by covering the exchange electrode 2 at the tip thereof 1, the pin 3 is provided on the side surface of the electrode body 1, and the engagement groove 2 b that engages with the pin 3 is formed on the side surface of the exchange electrode 2, so that the exchange electrode 2 can be exchanged.
[Selection] Figure 1

Description

  The present invention relates to an electrode for an electric resistance spot welder that can be easily repaired without being shaped when the electrode of the electric resistance welder is consumed.

  Conventionally, an electric resistance spot welder is one that presses and energizes a member to be welded between an upper electrode and a lower electrode and melts and welds the member to be welded with electric resistance heat flowing through the member to be welded. Yes, it is widely used when welding white bodies of automobiles.

  The electrode used in this electric resistance spot welder is deformed due to the applied pressure or wear with the use of the electrode. When the electrode is deformed, the member to be welded is scratched, causing poor welding or sputtering. For this reason, it is necessary for a skilled worker to perform recutting and shaping using a lathe or a drilling machine every predetermined number of times of welding (for example, 1500 to 5000 times). For this reason, skilled workers had to be stationed at the welding site.

  In addition, since the number of electrodes is reduced every time cutting is performed, there is a limit to the number of times of cutting, and when cutting a predetermined number of times, there is a problem that the entire electrode needs to be replaced and the running cost increases. In addition, the electrode used in the electric resistance spot welder must be prepared in accordance with the shape of the member to be welded and the welding conditions, and after these electrodes have been cut a predetermined number of times, the electrode must be replaced. For this reason, it is necessary to always stock an electrode having a shape matched to the shape of the member to be welded and the welding conditions as a stock, and inventory management has been difficult.

  In view of this, an electrode resistance spot welding electrode as shown in Patent Document 1 in which only the tip is replaceable has been proposed. In this electrode for electric resistance spot welding, a fitting recess is formed at the tip of the electrode body, and an exchange electrode is fitted into this fitting recess. With such a structure, when the electrode is consumed, the electrode repair work is completed simply by replacing the replacement electrode, so that productivity is improved. However, since the replacement electrode is fitted into the fitting recess of the electrode body and the replacement electrode is attached to the electrode body, when the replacement electrode is welded to the member to be welded, the member to be welded is removed from the electrode body at the same time. There has been a problem that the exchange electrode falls off from the electrode body.

Registered Utility Model No. 3130582

  An object of the present invention is to solve the above-mentioned problems and to provide an electrode for an electric resistance spot welding machine of an exchange type in which the exchange electrode does not fall off during welding.

The device according to claim 1, which has been made in order to solve the above problems, has a bottomed cylindrical exchange electrode whose upper surface is a contact surface with a member to be welded,
The exchange electrode is composed of an electrode main body to which the exchange electrode is attached by covering the tip of the exchange electrode,
The replacement electrode is configured to be replaceable.

The device according to claim 2 is the device according to claim 1, wherein a center pin sliding portion is formed in communication with the electrode body,
A center pin through hole communicating with the center pin sliding portion is formed on the upper surface of the exchange electrode,
A center pin that holds the screw hole of the weld nut at its tip is passed through the center pin through hole, and its tip protrudes from the replacement electrode, and is slidably disposed on the center pin sliding portion. It was set up.

The invention according to claim 3 is the invention according to claim 1, wherein a bolt insertion part having an open shape is formed on the upper surface of the electrode body, and a screw part of a weld bolt is inserted,
A bolt insertion hole that communicates with the bolt insertion portion is formed in the exchange electrode.

  The device described in claim 4 is characterized in that, in the devices described in claims 1 to 3, the replacement electrode is fixed to the electrode body by a fixing mechanism.

The device according to claim 5 is the device according to claim 4, wherein a projection is provided on a side surface of the electrode body,
An engagement groove that engages with the protrusion is formed on a side surface of the exchange electrode to form a fixing mechanism.

  The device described in claim 6 is characterized in that, in the device described in claim 5, a pin hole is formed in a side surface of the electrode body, and a pin is inserted into the pin hole to form a protrusion. To do.

  The device according to claim 7 is the device according to claim 5 or 6, wherein the engaging groove includes a vertical groove communicating with the lower end of the exchange electrode and a horizontal groove connected to the upper end of the vertical groove. It is characterized by comprising.

The invention according to claim 8 is the invention according to claim 4 or claim 4, wherein a through hole is formed on a side surface of the exchange electrode,
The pin is inserted into the side surface of the electrode body in a state in which the pin is passed through the through hole, thereby forming a fixing mechanism.

  The device described in claim 9 is the device described in any one of claims 6 to 8, wherein a screw groove is screwed into the pin hole, and a screw thread that is screwed into the screw groove is screwed into the outer peripheral surface of the pin. The pin is screwed into the pin hole.

  The device described in claim 10 is characterized in that, in the devices described in claims 6-9, the pin is made of a metal having high hardness and toughness.

  The device described in claim 11 is characterized in that, in the device described in claim 10, the pin is made of an iron-based metal.

  The device described in claim 12 is characterized in that, in the devices described in claims 1 to 11, the electrode body and the exchange electrode are made of different materials.

  The device described in claim 13 is characterized in that, in the device described in claim 12, the exchange electrode is made of chromium copper.

  A device described in claim 14 is characterized in that, in the device described in claim 12, the exchange electrode is made of beryllium copper.

  The invention according to claim 15 is the invention according to claim 12, wherein the exchange electrode is made of any one of cadmium copper, zirconium copper, chromium zirconium copper, titanium copper, alumina dispersion strengthened copper, and sintered copper. It is characterized by.

  The invention described in claim 16 is the invention described in claims 9-15, wherein the electrode body is made of pure copper.

  The device described in claim 17 is characterized in that, in the devices described in claims 9-15, the electrode body is made of chromium copper.

  The invention according to claim 1 comprises a bottomed cylindrical exchange electrode, and an electrode body to which the exchange electrode is attached by covering the tip of the exchange electrode so that the exchange electrode can be exchanged. Because it is configured, when the electrode is consumed, it is possible to provide an electrode for an electric resistance spot welder that can be easily repaired without having to reshape the electrode by simply replacing the replacement electrode. It becomes. Further, since only the replacement electrode needs to be replaced, the running cost can be reduced. In addition, there is no need to stock stock electrodes that match the shape of the workpiece to be welded and welding conditions, and it is sufficient to stock only the common replacement electrodes for each electrode, making stock management easier. Become. Since the exchange electrode is in contact with the entire circumferential surface of the electrode body, the contact area is large and the exchange electrode is difficult to come off from the electrode body.

  According to the second aspect of the present invention, a center pin sliding portion is formed in communication with the electrode body, a center pin through hole communicating with the center pin sliding portion is formed on the upper surface of the replacement electrode, and a weld is formed at the tip thereof. Since the center pin that holds the screw hole of the nut is passed through the center pin through hole and the tip of the center pin protrudes from the exchange electrode, the center pin slide part is slidably disposed on the center pin. The weld nut can be welded, and the electrode repair work is completed by replacing only the replacement electrode. Therefore, there is no need for shaping, and electric resistance spot welding for weld nut welding can be easily repaired. It has become possible to provide mechanical electrodes.

  The invention according to claim 3 forms a bolt insertion part having an open shape into which the screw part of the weld bolt is inserted into the electrode body, and communicates with the bolt insertion part on the upper surface of the exchange electrode. Since the bolt insertion hole is formed and the weld bolt can be welded to the welded member, the weld bolt can be welded, and the electrode repair work is completed by replacing only the replacement electrode. Therefore, it is possible to provide an electrode for an electric resistance spot welder for welding bolt welding that can be easily repaired without being shaped.

  The invention described in claim 4 is characterized in that the replacement electrode is fixed to the electrode body by a fixing mechanism. For this reason, even if the replacement electrode is welded to the member to be welded during welding, it is possible to prevent the replacement electrode from dropping from the electrode body because the replacement electrode is fixed to the electrode body.

  According to the fifth aspect of the present invention, the protrusion is provided on the side surface of the electrode body, and the engaging groove that engages with the protrusion is formed on the side surface of the replacement electrode. Electrodes can be detached and workability is improved.

  According to the sixth aspect of the present invention, the pin hole is formed in the side surface of the electrode main body, and the pin is inserted into the pin hole to form the protrusion. Therefore, the strong protrusion can be easily formed on the side surface of the electrode main body. It became possible to project to.

  In the invention according to claim 7, since the engaging groove is composed of a vertical groove communicating with the lower end of the exchange electrode and a horizontal groove connected to the upper end of the vertical groove, a protrusion is put in the vertical groove, The replacement electrode can be attached to the electrode body by a simple operation of covering the replacement electrode on the electrode body, rotating the replacement electrode by a predetermined angle with respect to the electrode body, and positioning the protrusion at the bottom of the horizontal groove, Workability is very good, and production efficiency can be improved. Also, the exchange electrode can be removed from the electrode body simply by rotating the exchange electrode in the opposite direction to release, releasing the engagement state between the protrusion and the horizontal groove, and pulling the exchange electrode upward. Workability is very good, and production efficiency can be improved.

  In the invention according to claim 8, a through hole is formed in the side surface of the exchange electrode, a pin hole is drilled in the side surface of the electrode body, and the pin is inserted into the through hole. Since the replacement electrode is firmly fixed to the electrode body because it is inserted into the pin hole, it is possible to completely prevent the replacement electrode from falling off the electrode body.

  In the invention according to claim 9, since the screw groove is screwed into the pin hole, the screw thread screwed into the screw groove is screwed into the outer peripheral surface of the pin, and the pin is screwed into the pin hole. The pin is firmly fixed to the pin hole, and the pin does not fall out of the pin hole.

  In the device according to the tenth aspect, since the pin is made of a metal having high hardness and toughness, the pin is not damaged.

  According to the eleventh aspect of the present invention, since the pin is made of an iron-based metal, a pin having high hardness and toughness can be manufactured at a low cost, and the pin is not damaged.

  According to the twelfth aspect of the present invention, since the electrode body and the exchange electrode are made of different materials, it is possible to select optimum materials for the electrode body and the exchange electrode. For this reason, the replacement electrode can be made of a material that hardly deforms even at a high temperature, and the electrode body can be made of a material having a low electrical resistivity. Chrome copper is about 2.5 times more expensive than pure copper, and beryllium copper is about 10 times more expensive than pure copper. There is no need to use the battery, which can greatly reduce the cost.

  In the invention according to claim 13, since the exchange electrode is made of chromium copper, it is possible to suppress softening of the electrode at high temperature and to suppress deformation at high temperature.

  In the invention described in claim 14, since the exchange electrode is made of beryllium copper, not only can the deformation at high temperature be suppressed, but also the hardness at room temperature is high, so welding is performed with a high pressure. It became possible.

  In the invention described in claim 15, since the exchange electrode is composed of any one of cadmium copper, zirconium copper, chromium zirconium copper, titanium copper, alumina dispersion strengthened copper, and sintered copper, it suppresses deformation at high temperature. Became possible.

  In the device according to claim 16, since the electrode body is made of pure copper having a low electrical resistance, the electrical resistance of the pure copper is small, so that heat generation in the electrode body can be suppressed and the efficiency can be improved. .

  In the device according to claim 17, since the electrode main body is made of chrome copper, it is possible to suppress the deformation of the electrode main body.

(First embodiment)
Hereinafter, a preferred embodiment (first embodiment) of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a replaceable electric resistance spot welding electrode 10 of the present invention. An electrode 10 for an electric resistance spot welder according to the first embodiment includes an electrode body 1, an exchange electrode 2, and a pin 3. In FIG. 1, (A) is a top view of the electrode 10 for replaceable electric resistance spot welding, (B) is a side sectional view of (A), and (C) is a side view of the exchange electrode 2.

  The electrode body 1 has a substantially cylindrical shape. The base side of the electrode main body 1 has a tapered shape in which the outer diameter gradually decreases toward the base end, and serves as a mounting portion 1b. The electrode main body 1 is attached to an electric resistance spot welder (not shown) by the attachment portion 1b, and current is supplied. The electrode body 1 is provided with a cooling water passage 1 a that opens to the base end of the electrode body 1. Cooling water is introduced into the cooling water passage 1a from an electric resistance spot welder so that the electrode body 1 is cooled. The material of the electrode body 1 is preferably pure copper having a low electrical resistivity, but may be the same material as the exchange electrode 2 described later.

  A pin hole 1 c is formed in the peripheral surface (side surface) of the tip portion of the electrode body 1. In the present embodiment, the pin hole 1c is a screw hole. The pin 3 penetrates and is attached to the pin hole 1c. In the present embodiment, the pin 3 is a so-called imo screw in which a screw thread is formed on the outer peripheral surface and a hexagonal hole is formed on the base end. The pin 3 may be press-fitted into the pin hole 1c and the pin 3 may be fixed to the pin hole 1c. In a state where the pin 3 is attached to the electrode body 1, the base end of the pin 3 protrudes from the peripheral surface (side surface) of the distal end portion of the electrode body 1. In the present embodiment, since the pin 3 is made of an iron-based metal having high hardness and toughness such as stainless steel or steel, the pin 3 is hardly damaged.

  FIG. 2 is an explanatory diagram of another example of the pin 3. As shown in FIG. 2A, a pin 3 having a screw head with a hexagonal hole may be used. Further, as shown in FIG. 2B, a pin 3 having a hexagonal cylindrical screw head may be used. Alternatively, as shown in FIG. 2C, a pin 3 having a thumbscrew shape may be used.

  The exchange electrode 2 has a flat bottomed cylindrical shape and covers the tip of the electrode body 1. The inner diameter of the exchange electrode 2 is slightly larger than the outer diameter of the electrode body 1. The bottom surface (upper surface) of the exchange electrode 2 is a contact surface 2a that contacts the member to be welded, and current flows from the contact surface 2a to the member to be welded.

The exchange electrode 2 is made of chromium copper (copper obtained by adding 0.5 to 1% chromium to copper) or beryllium copper (copper added to copper), which is a material that hardly deforms even at high temperatures in order to reduce deformation during welding. It is preferable to use (copper added with 0.5 to 1.5% beryllium and 2 to 2.5% cobalt). The beryllium copper includes nickel and beryllium copper (copper obtained by adding 0.2 to 0.5 beryllium and 1.2 to 1.6% nickel to copper). The material of the exchange electrode 2 is cadmium copper (copper obtained by adding 0.5 to 1% cadmium to copper), zirconium copper, chromium zirconium copper, titanium copper, alumina dispersion strengthened copper, sintered copper, and the like. There is no problem. Here, the alumina dispersion-strengthened copper is copper strengthened by dispersing fine particles of alumina (Al ₂ O ₃ ) in copper, and sintered copper is powdered copper and copper obtained by sintering tungsten. is there.

  As described above, the electrode 10 for the replaceable electric resistance spot welder is constituted by the exchange electrode 2 that can be exchanged with the electrode body 1, so that the electrode body 1 and the exchange electrode 2 can be constituted by different materials. It becomes possible to select the most suitable material for each.

  An engagement groove 2 b is formed in communication with the peripheral surface (side surface) of the exchange electrode 2. The engaging groove 2b has a substantially L shape and is composed of a vertical groove 2c and a horizontal groove 2d. The lower end of the vertical groove 2 c communicates with the lower end of the peripheral surface of the exchange electrode 2 and is open. The horizontal groove 2d is connected to the upper end of the vertical groove 2c. Note that the engaging groove 2b may be substantially T-shaped.

  In order to attach the exchange electrode 2 to the electrode body 1, a pin 3 is inserted into the vertical groove 2c, the exchange electrode 2 is covered with the electrode body 1, and the exchange electrode 2 is rotated by a predetermined angle with respect to the electrode body 1. Then, the pin 3 is positioned at the bottom of the horizontal groove 2d. In the state where the exchange electrode 2 is attached to the electrode body 1, the pin 3 and the horizontal groove 2d are engaged, and the exchange electrode 2 is restricted from moving upward with respect to the electrode body 1. Even if the exchange electrode 2 is welded to the member to be welded, the exchange electrode 2 does not fall off from the electrode body 1.

  When the predetermined number of welding passes and the exchange electrode 2 is deformed by repeating welding, the electrode replacement is completed by removing the exchange electrode 2 and replacing it with a new exchange electrode 2. Note that the replacement electrode 2 may be cut and used with a drilling machine or a lathe. In the present invention, the exchange electrode 2 is rotated in the direction opposite to that at the time of attachment, the engagement state between the pin 3 and the horizontal groove 2d is released, and the exchange electrode 2 is simply lifted upward. Therefore, the replacement work of the replacement electrode 2 is easy.

(Second Embodiment)
FIG. 3 shows an explanatory diagram of the second embodiment, and the second embodiment will be described. The electrode 20 for a replaceable electric resistance spot welder according to the second embodiment includes an electrode body 11, an electrode holder 12, a center pin 13, an exchange electrode 14, a packing 15, a coil spring 16, and a spring holding member 17. . 2A is a top view of the replaceable electric resistance spot welding electrode 20, FIG. 2B is a side sectional view of FIG. 2A, and FIG. 2C is a side view of the exchange electrode 14.

  In addition, 22 is a member to be welded, 23 is a weld nut, and a plurality of projections 23a are projected on the seating surface. The projection 23a is attached by concentrating an electric current at the time of electric resistance spot welding, melting at the time of welding, and melted with the molten metal of the member 22 to be welded and integrated with the member 22 to be welded.

  The electrode body 11 has a substantially cylindrical shape, and a center pin sliding portion 11c is formed in communication with the shaft center. The lower part of the electrode main body 11 is smaller than the outer diameter other than the lower part, and a screw thread is formed to form an attachment part 11a.

  The electrode holder 12 has a substantially cylindrical shape, and is formed with an air conduction port 12a opened at the top. From the side surface of the electrode holder 12, an air introduction port 12b communicating with the air conduction port 12a is formed. A screw thread is formed in the upper part of the air conduction port 12a, and the electrode body 11 is integrally attached to the electrode holder 12 by being screwed with the screw thread formed in the mounting portion 11a of the electrode body 11. It has been. The base side of the electrode holder 12 has a tapered shape with the outer diameter gradually decreasing toward the base end, and serves as a mounting portion 12d. With the attachment portion 12d, the electrode holder 12 is attached to an electric resistance spot welder (not shown), and current is supplied. On the proximal end side of the electrode holder 12, a cooling water passage 12 c that opens to the proximal end of the electrode holder 12 is formed.

  The center pin 13 includes a cylindrical shaft portion 13a, a nut holding portion 13b formed at the tip of the shaft portion 13a, and a flange portion 13c provided at the base end of the shaft portion 13a. The center pin 13 is made of an insulating material such as KCF (stainless steel, whose surface is treated with an insulating coating), ceramics, and the like.

  The outer diameter of the nut holding portion 13b of the center pin 13 is smaller than the outer diameter of the shaft portion 13a. A tapered portion 13d whose outer diameter gradually decreases from the upper end of the shaft portion 13a toward the nut holding portion 13b is formed.

  The flange portion 13c has a tapered portion whose outer diameter gradually increases from the base end of the center pin 13 to the lower side, and the lower side of the tapered portion has a substantially cylindrical shape. The center pin 13 is slidably disposed on the center pin sliding portion 11 c of the electrode main body 11. The nut holding portion 13b of the center pin 13 passes through the center pin through hole 14e and protrudes from the contact surface 14a of the exchange electrode 14. The outer diameter of the center pin sliding portion 11c is slightly larger than the outer diameter of the shaft portion 13a of the center pin 13, and an air described later between the center pin sliding portion 11c and the shaft portion 13a of the center pin 13 is used. Has a structure capable of conducting.

  A receiving portion 11d that slidably receives the flange portion 13c with an outer diameter slightly larger than the outer diameter of the flange portion 13c of the center pin 13 below the center pin sliding portion 11c of the electrode body 11. It is provided coaxially with the center pin sliding portion 11c. The receiving portion 11 d communicates with the air conduction port 12 a of the electrode holder 12.

  A ring-shaped packing 15 is disposed at the upper end of the receiving portion 11d in a state where the shaft portion 13a of the center pin 13 is inserted. The flange portion 13c of the center pin 13 presses the packing 15 to prevent air from leaking. The packing 15 prevents the flange portion 13c and the upper end of the receiving portion 11d from coming into direct contact, and prevents the flange portion 13c from being worn or cracked.

  A spring holding member 17 is disposed at the bottom of the air conduction port 12 a of the electrode holder 12. A coil spring 16 is attached to the spring holding member 17. The coil spring 16 is in contact with the lower surface of the flange portion 13c of the center pin 13 and urges the center pin 13 upward. At the center of the spring holding member 17, an air conduction hole 17 a is formed so as to communicate vertically, and air supplied from the air introduction port 12 b is supplied to the air conduction port 12 a. Instead of the coil spring 13, the center pin 13 may be urged upward by air.

  A pin hole 11 b is formed in the side surface (circumferential surface) of the distal end portion of the electrode body 11. In the present embodiment, the pin hole 11b is a screw hole. The pin 3 penetrates and is attached to the pin hole 11b. In the present embodiment, the pin 3 is a so-called imo screw in which a screw thread is formed on the outer peripheral surface and a hexagonal hole is formed on the base end. Note that the pin 3 may be press-fitted into the pin hole 11b and the pin 3 may be fixed to the pin hole 11b. In a state where the pin 3 is attached to the electrode body 11, the base end of the pin 3 protrudes from the side surface (circumferential surface) of the electrode body 11. In the present embodiment, since the pin 3 is made of an iron-based metal having high hardness and toughness such as stainless steel or steel, the pin 3 is hardly damaged. In addition, the pin 3 may be the pin 3 shown to (A)-(B) of FIG.

  The exchange electrode 14 has a flat bottomed cylindrical shape and covers the tip of the electrode body 11. The inner diameter of the exchange electrode 14 is slightly larger than the outer diameter of the electrode body 11. The bottom surface (upper surface) of the exchange electrode 14 is a contact surface 14a that comes into contact with the member to be welded, and a current flows from the contact surface 14a to the member to be welded. A center pin through hole 14e is formed in communication with the center of the bottom surface of the exchange electrode 14. The center pin through hole 14 e communicates with the center pin sliding portion 11 c of the electrode body 11. The center pin 13 protrudes from the center pin through hole 14e and is exposed to the outside.

  An engagement groove 14 b is formed in communication with the peripheral surface (side surface) of the exchange electrode 14. The engaging groove 14b has a substantially L shape and is composed of a vertical groove 14c and a horizontal groove 14d. The lower end of the vertical groove 14 c communicates with the lower end of the peripheral surface (side surface) of the exchange electrode 14 and is open. The horizontal groove 14d is connected to the upper end of the vertical groove 14c. Note that the engagement groove 14b may be substantially T-shaped.

  In order to attach the exchange electrode 14 to the electrode body 11, as in the first embodiment, the pin 3 is inserted in the vertical groove 14c, the exchange electrode 14 is covered with the electrode body 11, and the exchange electrode 14 is attached to the electrode body. The pin 3 is positioned at the bottom of the horizontal groove 14d by rotating it by a predetermined angle with respect to the main body 11.

  The weld nut 23 is held by the screw hole 23b being inserted into the nut holding portion 13b of the center pin 13. As described above, the coil spring 16 presses the flange portion 13c of the center pin 13, and the center pin 13 is lifted. The weld nut 23 is also lifted. At this time, the tapered portion 23c formed at the lower end of the screw hole 23b of the weld nut 20 and the tapered portion 13d of the center pin 13 come into contact with each other, so that the weld nut 23 is Centering is performed by being arranged at the center of the axis of the center pin 13.

  In addition, the projection 23 a is also lifted from the member to be welded 22. In this state, when the weld nut 23 is pressed by the upper electrode (not shown) and pressed downward, the projection 23a comes into contact with the welded member 22, and the weld nut 23 and the welded member 22 are energized. The projection 23 a is melted, and the weld nut 23 is welded to the welded member 22. At this time, spatter is generated. At the time of welding, the center pin 13 is pushed by the upper electrode and slides downward, and the flange portion 13c of the center pin 13 is separated from the packing 15, so that the air conduction port 12a The supplied air is conducted and discharged between the center pin 13 and the center pin sliding portion 11c, and the spatter is blown to the outside so that the spatter adheres to the center pin 13, the exchange electrode 14, and the electrode body 11. And preventing the inside of the electrode body 11 from entering. Further, the electrode body 11 and the center pin 13 are cooled by the air conducted between the center pin 13 and the center pin sliding portion 11c. Thus, since the electrode main body 11 and the center pin 13 are cooled, the lifetimes of the electrode main body 11 and the center pin 13 are prolonged.

  In a state where the exchange electrode 14 is attached to the electrode body 11, the pin 3 and the horizontal groove 14d are engaged with each other, and the exchange electrode 14 is restricted from moving upward with respect to the electrode body 1. Even if the exchange electrode 14 is welded to the member to be welded, the exchange electrode 14 does not fall off the electrode body 11. Even if air is supplied from the air inlet 12b, the pin 3 and the horizontal groove 14d are engaged with each other, so that the exchange electrode 14 does not fall off the electrode body 11 due to the air.

  The electrode body 11 and the electrode holder 12 are made of the same material as the electrode body 1 of the first embodiment, and the exchange electrode 14 is made of the same material as the exchange electrode 2 of the first embodiment. is there.

(Third embodiment)
FIG. 4 shows a front view of the third embodiment, and the third embodiment will be described. The electrode 30 for the replaceable electric resistance spot welder according to the third embodiment includes an electrode body 31, an exchange electrode 32, an electrode holder 33, and an insulating member 38. 4A is a top view of the replaceable electric resistance spot welding electrode 30, FIG. 4B is a side sectional view of FIG. 4A, and FIG. 4C is a side view of the exchange electrode 32. Reference numeral 41 denotes a member to be welded, reference numeral 42 denotes a weld bolt, and a plurality of projections 42a project from the screw portion 42b side of the head portion 42c.

  The electrode body 31 has a substantially cylindrical shape. A bolt insertion portion 31 b is formed in communication with the axial center of the electrode body 31 in the vertical direction. The lower part of the electrode main body 31 is smaller than the outer diameter other than the lower part, and a screw thread is formed to form an attachment part 31a. The electrode holder 33 has a substantially cylindrical shape, and is formed with an air conduction port 33a opened at the top. From the side surface of the electrode holder 33, an air introduction port 33b communicating with the air conduction port 33a is formed. A screw thread is formed in the upper part of the air conduction port 33a, and the electrode body 31 is integrally attached to the electrode holder 33 by being screwed with the screw thread formed in the mounting portion 31a of the electrode body 31. It has been. The base side of the electrode holder 33 has a taper shape in which the outer diameter gradually decreases toward the base end, and serves as a mounting portion 33d. With the attachment portion 33d, the electrode holder 33 is attached to an electric resistance spot welder (not shown), and current is supplied. On the base end side of the electrode holder 33, a substantially cylindrical cooling water passage 33 c that opens to the base end of the electrode holder 33 is formed.

  A pin hole 31 c is formed in the side surface of the tip portion of the electrode body 31. In the present embodiment, the pin hole 31c is a screw hole. The pin 3 penetrates and is attached to the pin hole 31c. In the present embodiment, the pin 3 is a so-called imo screw in which a screw thread is formed on the outer peripheral surface and a hexagonal hole is formed on the base end. The pin 3 may be press-fitted into the pin hole 31c and the pin 3 may be fixed to the pin hole 31c. In a state where the pin 3 is attached to the electrode body 31, the proximal end of the pin 3 protrudes from the peripheral surface of the electrode body 31. In the present embodiment, since the pin 3 is made of an iron-based metal having high hardness and toughness such as stainless steel or steel, the pin 3 is hardly damaged. In addition, the pin 3 may be the pin 3 shown to (A)-(B) of FIG.

  The exchange electrode 32 has a flat bottomed cylindrical shape, and covers the tip of the electrode body 31. The inner diameter of the exchange electrode 32 is slightly larger than the outer diameter of the electrode body 31. The bottom surface (upper surface) of the exchange electrode 32 is a contact surface 32a that comes into contact with the member to be welded, and a current flows from the contact surface 32a to the member 41 to be welded. A bolt insertion hole 32e is formed in communication with the center of the bottom surface of the exchange electrode 32. The bolt insertion hole 32 e communicates with the bolt insertion portion 31 b of the electrode body 31.

  An engagement groove 32 b is formed in communication with the peripheral surface (side surface) of the exchange electrode 32. The engaging groove 32b is substantially L-shaped, and includes a vertical groove 32c and a horizontal groove 32d. The lower end of the vertical groove 32 c communicates with the lower end of the peripheral surface (side surface) of the exchange electrode 32 and is open. The horizontal groove 32d is connected to the upper end of the vertical groove 32c. The engaging groove 32b may be substantially T-shaped.

  In order to attach the exchange electrode 32 to the electrode body 31, the pin 3 is inserted into the vertical groove 32 c and the exchange electrode 32 is covered on the electrode body 31 in the same manner as in the first embodiment and the second embodiment. The exchange electrode 32 is rotated by a predetermined angle with respect to the electrode body 31, and the pin 3 is positioned at the bottom of the horizontal groove 32d.

  A substantially cylindrical insulating member 38 is disposed inside the bolt insertion portion 31 b of the electrode body 31. The insulating member 38 is made of an insulator such as bakelite, KCF (stainless steel, whose surface is subjected to an insulating coating treatment), ceramics, or the like.

  With the member to be welded 41 placed on the exchange electrode 32, the screw part 42 a of the weld bolt 42 is inserted into the bolt insertion hole 32 e and the bolt insertion part 31 b of the exchange electrode 32. In this state, the threaded portion 42 b of the weld bolt 42 is in a state where the periphery is covered with the insulating member 38. In this state, when the upper electrode (not shown) presses and presses the head portion 42c of the weld bolt 42 and energizes between the upper electrode and the exchange electrode 32, the projection 42a melts and the weld bolt 42 is covered. It is welded to the welding member 41. At this time, spatter is generated. Air is supplied from the air inlet 33b immediately after welding, and this air is conducted and discharged between the threaded portion 42b of the weld bolt 42 and the insulating member 38. Blowing outside prevents the spatter from adhering to the exchange electrode 32 and the electrode body 31, and prevents the spatter from entering the insulating member 38 side. Further, the electrode body 31 is cooled by the air conducted between the threaded portion 42 b of the weld bolt 42 and the insulating member 38. Thus, since the electrode main body 31 is cooled, the lifetime of the electrode main body 31 becomes long. At the time of welding, the screw portion 42b of the weld bolt 42 is covered with the insulating member 38, so that the discharge between the screw portion 42b of the weld bolt 42 and the bolt insertion portion 31b is prevented. The thread portion 42b is protected.

  The weld bolt welded in the third embodiment also includes a weld bolt 52 having a projection 52a that protrudes on the opposite side of the threaded portion 52b of the head 52c, as shown in FIG. The threaded portion 52b of the weld bolt 52 is inserted into the bolt insertion portion 31b, and the welding member 51 is attached to the weld bolt 52 in a state where the head 52c of the weld bolt 52 which is a welded member and the contact surface 32a of the replacement electrode 32 are in contact. When the welded member 51 is pressed and pressed with the upper electrode (not shown) by placing it on the head 52c, a current flows between the upper electrode and the exchange electrode 32, and the projection 52a is melted. The weld bolt 52 is welded to the member 51 to be welded.

  In the above description, the present invention has been described with respect to an embodiment in which pin holes 1c, 11b, 31c are formed in the electrode bodies 1, 11, 31 and the pins 3 are attached to the pin holes 1c, 11b, 31c. The present invention is not limited to this embodiment, and the electrode body 1, 11, 31 may be provided with a pin-shaped protrusion by cutting, casting, or forging.

  In addition, as shown in FIG. 6, a through hole 2 e is formed in the side surface (circumferential surface) of the exchange electrode 2, and the pin 3 is inserted into the electrode bodies 1, 11 in a state where the pin 3 is passed through the through hole 2 e. , 31 may be inserted into pin holes 1c, 11b, 31c formed on the side surfaces (peripheral surfaces) of the electrode body 31 and the exchange electrode 2 may be fixed to the electrode bodies 1, 11, 31. In this case, it is possible to completely prevent the exchange electrode 2 from falling off the electrode bodies 1, 11, 31. Note that the pins 3 may be the pins (A) to (C) shown in FIG. Further, a screw thread is screwed into the pin 3, and a screw groove is screwed into the pin holes 1c, 11b, 31c to be screwed into the screw thread of the pin 3, and the pin 3 is pinned into the pin holes 1c, 11b, It does not matter even if it is fixed to 31c.

  Although the present invention has been described above in relation to the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein. The electrode for a replaceable resistance spot welder with such a change is also within the technical scope without departing from the scope of the utility model registration request and the gist or idea of the invention that can be read from the entire specification. Must be understood as encompassed by.

It is explanatory drawing of the electrode for interchangeable electrical resistance spot welding of 1st Embodiment. It is explanatory drawing which showed the other example of the pin. It is explanatory drawing of the electrode for interchangeable electrical resistance spot welding of 2nd Embodiment. It is explanatory drawing of the electrode for interchangeable electrical resistance spot welding of 3rd Embodiment. It is explanatory drawing of the electrode for interchangeable electrical resistance spot welding of 3rd Embodiment. (Another example) It is another example of the structure which fixes an exchange electrode to an electrode main body.

Explanation of symbols

1 Electrode body (first embodiment)
1a Cooling water passage 1b Mounting portion 1c Pin hole 2 Exchange electrode (first embodiment)
2a Contact surface 2b Engaging groove 2c Vertical groove 2d Horizontal groove 2e Through-hole 3 Pin 10 Electrode for replaceable electric resistance spot welding (first embodiment)
11 Electrode body (second embodiment)
11a Mounting portion 11b Pin hole 11c Center pin sliding portion 11d Receiving portion 12 Electrode holder (second embodiment)
12a Air conduction port 12b Air introduction port 12c Cooling water passage 12d Mounting portion 13 Center pin 13a Shaft portion 13b Nut holding portion 13c Flange portion 13d Taper portion 14 Replacement electrode (second embodiment)
14a Contact surface 14b Engagement groove 14c Vertical groove 14d Horizontal groove 14e Center pin through hole 15 Packing 16 Coil spring 17 Spring holding member 17a Air conduction hole 20 Electrode for spot-type exchange resistance (second embodiment)
22 to-be-welded member 23 weld nut 23a projection 23b screw hole 23c taper part 30 replaceable electrode for electric resistance spot welding (third embodiment)
31 Electrode body (third embodiment)
31a Mounting portion 31b Bolt insertion portion 31c Pin hole 32 Exchange electrode 32a Contact surface 32b Engaging groove 32c Vertical groove 32d Horizontal groove 32e Bolt insertion hole 33 Electrode holder (third embodiment)
33a Air conduction port 33b Air introduction port 33c Cooling water passage 33d Mounting portion 38 Insulating member 41 Welded member 42 Weld bolt 42a Projection 42b Screw portion 42c Head 51 Welded member 52 Weld bolt (another example)
52a Projection 52b Screw part 52c Head

Claims (17)

A bottomed cylindrical replacement electrode whose upper surface is a contact surface with the member to be welded,
The exchange electrode is composed of an electrode main body to which the exchange electrode is attached by covering the tip of the exchange electrode,
An electrode for an exchangeable electric resistance spot welder, characterized in that the exchange electrode can be exchanged. A center pin sliding part is formed in communication with the electrode body,
A center pin through hole communicating with the center pin sliding portion is formed on the upper surface of the exchange electrode,
A center pin that holds the screw hole of the weld nut at its tip is passed through the center pin through hole, and its tip protrudes from the replacement electrode, and is slidably disposed on the center pin sliding portion. The electrode for a replaceable electric resistance spot welder according to claim 1, wherein the electrode is provided. On the upper surface of the electrode body, a bolt insertion part having an open shape is formed, into which a threaded part of a weld bolt is inserted,
The electrode for a replaceable electric resistance spot welder according to claim 1, wherein a bolt insertion hole communicating with the bolt insertion portion is formed in the exchange electrode.   The exchangeable spot welding electrode according to any one of claims 1 to 3, wherein the exchange electrode is fixed to the electrode body by a fixing mechanism. Protrusion on the side of the electrode body,
The exchangeable resistance spot welding electrode according to claim 4, wherein an engagement groove that engages with the protrusion is formed on a side surface of the exchange electrode to constitute a fixing mechanism.   6. The replaceable electric resistance spot welding electrode according to claim 5, wherein a pin hole is formed in a side surface of the electrode body, and a projection is formed by inserting the pin into the pin hole.   The replaceable type according to claim 5 or 6, wherein the engaging groove is composed of a vertical groove communicating with the lower end of the peripheral surface of the exchange electrode and a horizontal groove connected to the upper end of the vertical groove. Electric resistance spot welding electrode. A through hole is formed on the side surface of the exchange electrode,
Make a hole in the side of the electrode body,
5. The replaceable electric resistance spot welding electrode according to claim 4, wherein a fixing mechanism is configured by inserting the pin into the pin hole in a state where the pin is passed through the through hole.   The screw hole is screwed into the pin hole, the screw thread to be screwed into the screw groove is screwed into the outer peripheral surface of the pin, and the pin is screwed into the pin hole. The exchangeable resistance spot welding electrode according to claim 8.   The replaceable electric resistance spot welding electrode according to any one of claims 6 to 9, wherein the pin is made of a metal having high hardness and toughness.   11. The replaceable electric resistance spot welding electrode according to claim 10, wherein the pin is made of an iron-based metal.   The electrode for an exchangeable electric resistance spot welder according to any one of claims 1 to 11, wherein the electrode body and the exchange electrode are made of different materials.   The electrode for an exchangeable electric resistance spot welder according to claim 12, wherein the exchange electrode is made of chromium copper.   The exchange electrode spot welding machine electrode according to claim 12, wherein the exchange electrode is made of beryllium copper.   13. The exchangeable electric resistance spot welding machine according to claim 12, wherein the exchange electrode is composed of any one of cadmium copper, zirconium copper, chromium zirconium copper, titanium copper, alumina dispersion strengthened copper, and sintered copper. electrode.   The electrode for a replaceable electric resistance spot welder according to any one of claims 12 to 15, wherein the electrode body is made of pure copper.   The electrode for a replaceable electric resistance spot welder according to any one of claims 12 to 15, wherein the electrode body is made of chromium copper.

Images