Power feeding cable and method for manufacturing power feeding cable

Abstract

To provide a power feeding cable and a method for manufacturing a power feeding cable which can improve the operability of a horizontal gun and realize a smooth flow of cooling water in a power feeding cable, and further can cut down the manufacturing cost of a resistance-welding device.SOLUTION: A conductive member 240 is constituted of a plurality of copper fluxes 240a, and circumferential grooves 204, 224 the axial direction of which is depth direction on the opening side of a body part are formed at a first connection terminal 200 and a second connection terminal 220, respectively, in which one end of each of the plurality of copper fluxes 240a is placed in the circumferential groove 204 of the first connection terminal, and the other end of each of them in the circumferential groove 224 of the second connection terminal. A first tubular member 260 is placed in an almost cylindrical space formed according to the placement of the copper fluxes 240a between the first connection terminal and the second terminal.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a power supply cable used in a resistance welding apparatus equipped with a welding gun and a method for manufacturing the power supply cable.

Background Art

[0002] Conventionally, there has been a resistance welding apparatus that sandwiches a welding portion with electrodes in a state where at least two metal workpieces are overlapped, applies pressure while passing an electric current, and connects the workpieces with Joule heat generated at the welding portion.

[0003] Some resistance welding apparatuses include a table electrode formed in a substantially square flat plate shape and disposed in a direction perpendicular to the height direction of the apparatus body, and a welding gun that is movable in the plane direction of the table electrode and is vertically movable in a direction perpendicular to the plane direction of the table electrode (see, for example, Patent Document 1). The resistance welding apparatus described in this document has a welding gun called a "horizontal gun". The resistance welding apparatus described in this document was proposed by the present applicant.

[0004] FIG. 9 is a side view showing the appearance of a conventional resistance welding apparatus 500. FIG. 10 is a partial cross-sectional view showing the structure of the horizontal gun 600 of the resistance welding apparatus 500 in FIG. 9 and a diagram showing a power supply cable set 700 connected to the horizontal gun 600. As shown in FIG. 9 or FIG. 10, the horizontal gun 600 includes a gun body 601, a shank holder 602 attached to the tip portion of the gun body 601, a shank 603 attached to the tip portion of the shank holder 602, and an electrode tip 604 attached to the tip of the shank 603. The horizontal gun 600 is supported by a gun bracket 800 in a direction substantially perpendicular to the height direction of the apparatus body.

[0005] Also, as shown in FIG. 10, two flow paths 605 and 606 along the length direction of the gun body 601 are formed inside the gun body 601. One flow path 605 is a flow path on the cooling water inflow side, and the other flow path 606 is a flow path on the cooling water outflow side. One end of a long tube (pipe) 710 is connected to one opening 607 of the flow path 605 on the cooling water inflow side, and one end of a short tube 720 is connected to one opening 608 of the flow path 606 on the cooling water outflow side. The other end of the long tube 710 is connected to the device body side. Note that a cooling water circulation device (not shown) is disposed on the device body side, and the cooling water sent from this cooling water circulation device is sent to the horizontal gun 600 through the long tube 710. The other end of the short tube 720 is connected to one end of a power supply cable 730. Both the long tube 710 and the short tube 720 are made of a resin material having flexibility. Note that the above-described cooling water circulation device is also called a "chiller".

[0006] FIG. 11 is a diagram showing a part of the power supply cable 730. As shown in the figure, the power supply cable 730 includes a conductor member 731 composed of a plurality of copper wires for energization, connection members 732 attached to both ends of the conductor member 731, and a tube 733 made of a cylindrical rubber member covering the conductor member 731 and the connection members 732.

[0007] The conductor member 731 is formed by bundling a plurality of bundles each formed by twisting a large number of copper wires. The cooling water that has circulated around the horizontal gun 600 flows into the tube 733. The cooling water that has flowed into the tube 733 flows toward the above-described device body. The connection member 732 includes a connection portion 7321, a screw portion 7322, a pipe portion 7323, a fixing portion 7324, and an L-shaped portion 7325. The screw portion 7322 has a cylindrical shape with a smaller diameter than the connection portion 7321. The pipe portion 7323 has a cylindrical shape with substantially the same diameter as the screw portion 7322.

[0008] The fixing part 7324 and the L-shaped part 7325 are both integrally formed with the pipe part 7323. Through holes are formed along the axis in each of the connecting part 7321, the threaded part 7322, the pipe part 7323, and the L-shaped part 7325. That is, a through hole 7326 is formed in the connecting part 7321, a through hole 7327 is formed in the threaded part 7322, a through hole 7328 is formed in the pipe part 7323, and a through hole 7329 is formed in the L-shaped part 7325, respectively. The diameters of the through holes 7326, 7327, 7328, and 7329 are all the same.

[0009] The fixing part 7324 is a part for fixing the power supply cable 730 to the gun body 601. The L-shaped part 7325 is a part for connecting the other end of the short tube 720 to the power supply cable 730. One end side of the conductor member 731 is connected to one end side of the connecting part 7321 by brazing. This brazing is performed around the connecting part 7321 so as not to block the opening 7326a. As a conventional power supply cable, for example, there is one described in Patent Document 2.

[0010] In the horizontal gun 600, the cooling water sent out from a cooling water circulation device (not shown) flows into the internal flow path 605 of the gun body 601 through the tube 710. The cooling water flowing into the flow path 605 reaches the electrode tip 604 through the flow path inside the shank holder 602 and the flow path inside the shank 603 in sequence. The cooling water reaching the electrode tip 604 flows into the outer flow path 606 of the gun body 601 through the outer flow path of the shank 603 and the outer flow path of the shank holder 602 in sequence. The cooling water flowing into the outer flow path 606 of the gun body 601 flows into the power supply cable 730 through the tube 720. The cooling water flowing into the power supply cable 730 flows toward a cooling water circulation device (not shown).

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0012] By the way, the operability of the horizontal gun 600 improves as the number of tubes and cables connected thereto decreases. However, at present, since it is composed of three components: tubes 710 and 720 and the power supply cable 730, it cannot be said that good operability is necessarily obtained.

[0013] In addition, the need for tubes 710 and 720 and the power supply cable 730 increases the manufacturing cost of the resistance welding apparatus 500.

[0014] In addition, in the manufacture of the power supply cable 730, the connecting member 732 is joined to each of one end and the other end of the conductor member 731 by brazing. Although care is taken not to block the opening 7326a of the connecting member 732 during brazing, due to the somewhat random attachment, the flow of cooling water in the tube 733 may not be smooth. In such a case, stable cooling cannot be obtained. If the opening 7326a is blocked during brazing, it is necessary to reopen it.

[0015] The present invention has been made in view of such circumstances, and an object thereof is to provide a power supply cable and a method for manufacturing a power supply cable that can improve the operability of a horizontal gun, realize a smooth flow of cooling water in the power supply cable, and further reduce the manufacturing cost of a resistance welding apparatus.

Means for Solving the Problems

[0016] The power supply cable of the present invention includes a first flow path on the cooling water inflow side and a Second flow pathA power supply cable used in a resistance welding apparatus equipped with a horizontal gun having the following, comprising a flange portion and a main body portion made of a metallic material having conductivity, the flange portion having a columnar shape with a larger diameter than the main body portion, the main body portion having a columnar shape extending in the central axis direction from the flange portion, and formed in the main body portion and the flange portion, a first connection terminal having a through hole penetrating from the main body portion to the flange portion on the central axis of the main body portion and the flange portion, a second connection terminal having the same shape and made of the same metallic material as the first connection terminal, a conductive member made of a metallic material having conductivity and flexibility, one end of which is connected to the main body portion of the first connection terminal and the other end of which is connected to the main body portion of the second connection terminal, a first tubular member made of a resin material having flexibility, one end portion of which protrudes from the main body portion of the first connection terminal through the through hole and protrudes from the flange portion of the first connection terminal, and the other end portion of which protrudes from the main body portion of the second connection terminal through the through hole and protrudes from the flange portion of the second connection terminal, and a second tubular member made of a resin material having flexibility, one end of which is located on the flange portion side of the first connection terminal and the other end of which is located on the flange portion side of the second connection terminal, and accommodating the conductive member, the first tubular member, and cooling water. The conductive member is composed of a plurality of copper wire bundles. In each of the first connection terminal and the second connection terminal, a circumferential groove having an axial direction as a depth direction is formed on the opening side of the main body portion. One end portion of each of the plurality of copper wire bundles serving as the conductive member is disposed in the circumferential groove of the first connection terminal, and the other end portion of each of the plurality of copper wire bundles serving as the conductive member is disposed in the circumferential groove of the second connection terminal. The first tubular member is disposed within a substantially cylindrical space formed by the arrangement of the plurality of copper wire bundles between the first connection terminal and the second connection terminal. The flange portion side of the through hole of the first connection terminal communicates with the first flow path on the cooling water inflow side of the horizontal gun, and the protruding portion side of the first tubular member from the flange portion of the first connection terminal communicates with the second flow path on the cooling water outflow side of the horizontal gun. Part is located on the flange portion side of the first connection terminal, and the other end Part is located on the flange portion side of the second connection terminal, and a second tubular member that accommodates the conductive member, the first tubular member, and cooling water. The conductive member is composed of a plurality of copper wire bundles. In each of the first connection terminal and the second connection terminal, a circumferential groove having an axial direction as a depth direction is formed on the opening side of the main body portion. One end portion of each of the plurality of copper wire bundles serving as the conductive member is disposed in the circumferential groove of the first connection terminal, and the other end portion of each of the plurality of copper wire bundles serving as the conductive member is disposed in the circumferential groove of the second connection terminal. The first tubular member is disposed within a substantially cylindrical space formed by the arrangement of the plurality of copper wire bundles between the first connection terminal and the second connection terminal. The flange portion side of the through hole of the first connection terminal communicates with the first flow path on the cooling water inflow side of the horizontal gun, and the protruding portion side of the first tubular member from the flange portion of the first connection terminal communicates with the second flow path on the cooling water outflow side of the horizontal gun.

[0017] According to the above configuration, in the second tubular portion, a plurality of conductive members are formed as bundles of copper wires, and these bundles of copper wires are arranged side by side in the circumferential direction so as to form a substantially cylindrical shape between the first connection terminal and the second connection terminal, and the first tubular member is disposed within the substantially cylindrical conductive member thus formed. Therefore, a stable flow of cooling water within the second tubular member can be realized, and the cooling efficiency can be improved.

[0018] In addition, compared with the conventional configuration that requires two tubes and one power supply cable, only one power supply cable is needed. As a result, the operability of the horizontal gun can be improved, and the cost of manufacturing the resistance welding apparatus can be reduced.

[0019] The method for manufacturing a power supply cable of the present invention is a method for manufacturing a power supply cable used in a resistance welding apparatus including a horizontal gun having a first flow path on the cooling water inflow side and a second flow path on the cooling water outflow side. The power supply cable includes a flange portion and a main body portion made of a conductive metal material. The flange portion has a cylindrical shape with a larger diameter than the main body portion, and the main body portion has a cylindrical shape extending in the central axis direction from the flange portion. In the flange portion and the main body portion, a through hole is formed that penetrates from the main body portion to the flange portion on the central axis of the main body portion and the flange portion. Further, at an end of the main body portion, a first connection terminal having a circumferential groove with an axial direction as the depth direction is formed, a second connection terminal having the same shape and made of the same metal material as the first connection terminal, a conductive member made of a metal material having conductivity and flexibility and used for connecting the main body portion of the first connection terminal and the main body portion of the second connection terminal, a first tubular member made of a resin material having flexibility and disposed through the through hole of the first connection terminal and the through hole of the second connection terminal for flowing cooling water to the horizontal gun side, and a second tubular member made of a rubber material and disposed between the flange portion of the first connection terminal and the flange portion of the second connection terminal. A first step of disposing a third tubular member made of metal, which has a total length longer than that of the second tubular member and an outer diameter smaller than the outer diameter of the through hole of the first connection terminal and larger than the outer diameter of the first tubular member, between the first connection terminal and the second connection terminal. A second step of disposing one end of each of a plurality of copper wire bundles made as the conductive members in the circumferential groove of the first connection terminal and disposing the other end of each of the copper wire bundles in the circumferential groove of the second connection terminal; A third step of inserting the first tubular member into the third tubular member; A fourth step of brazing one end of each of the plurality of copper wire bundles disposed in the circumferential groove of the first connection terminal to the first connection terminal and brazing the other end of each of the plurality of copper wire bundles disposed in the circumferential groove of the second connection terminal to the second connection terminal; A fifth step of disposing the second tubular member between the flange portion of the first connection terminal and the flange portion of the second connection terminal; A sixth step of extracting the third tubular member after completion of the fifth step.

[0020] According to the above method, in the second tubular portion, a plurality of conductive members are formed as a plurality of copper wire bundles, and these copper wire bundles are arranged side by side in the circumferential direction so as to form a substantially cylindrical shape between the first connection terminal and the second connection terminal. Since the first tubular member is disposed in the substantially cylindrical conductive member, a stable flow of cooling water in the second tubular member can be realized, and the cooling efficiency can be improved.

[0021] In addition, compared with the conventional method that requires two tubes and one power supply cable, only one power supply cable is required, so that the operability of the horizontal gun can be improved, and the cost of manufacturing the resistance welding device can be reduced.

Advantages of the Invention

[0022] According to the present invention, the operability of the horizontal gun can be improved, a smooth flow of cooling water in the power supply cable can be realized, and further, the manufacturing cost of the resistance welding device can be reduced.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0024] Hereinafter, preferred embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[0025] Fig. 1 is a view of the appearance of the resistance welding apparatus 1 according to the present embodiment as seen from the side. In the figure, the resistance welding apparatus 1 according to the present embodiment includes a support post 4, an arm 5 having a multi-joint structure, a gun bracket 6, a horizontal gun 7, a pressure cylinder 8, a power supply cable 9, a table electrode 10, a welding transformer 11, and a pedestal 12.

[0026] The arm 5 includes two arm portions 5A and 5B, and a rotating shaft 5C that rotatably connects these arm portions 5A and 5B in a direction perpendicular (horizontal direction) to the standing direction of the support post 4. The arm 5 is supported by the support post 4 at a rotating shaft 5D at its base end. The arm 5 supports the gun bracket 6 at the tip portion of the arm portion 5B in the same direction as the standing direction of the support post 4. The gun bracket 6 supports the horizontal gun 7 at its lower end. Also, the upper end of the gun bracket 6 is connected to the tip portion of the arm portion 5B in the same direction as the standing direction of the support post 4. The gun bracket 6 is rotatable in the same direction as the direction of the arm portion 5B (horizontal direction).

[0027] The horizontal gun 7 has a shank holder 71 for mounting the shank 15. An electrode tip 16 is mounted on the tip portion of the shank 15. The shank 15 has a bent shape called an "offset shank". Note that there is also a straight-shaped shank called a "straight shank" for the shank. The shank 15 in the present disclosure is a bent offset shank. The offset shank is mainly used for welding in narrow places.

[0028] FIG. 2 is a diagram showing the structure of a part of the horizontal gun 7 and the structure of the power supply cable 9 of the resistance welding apparatus 1 according to the present embodiment. In the figure, the horizontal gun 7 includes a gun tip portion 7A to which the shank holder 71 is mounted and to which the power supply cable 9 is connected, a gun rear end portion 7B for attaching the horizontal gun 7 to the gun bracket 6, a handle 73 attached to the rear end portion of the gun rear end portion 7B, and the above-described shank holder 71. The horizontal gun 7 is supported by the shaft 61 of the gun bracket 6, and the tip of the horizontal gun 7 moves up and down so as to draw an arc around this shaft 61.

[0029] Inside the tip portion 7A of the horizontal gun 7, two flow paths 80 and 81 for passing cooling water are formed. Cooling water sent through the power supply cable 9 flows through one of these two flow paths (the first flow path) 80, and cooling water that has circulated inside the horizontal gun 7 flows through the other flow path (the second flow path) 81. Thus, one of the first flow paths 80 is a flow path for supplying cooling water to the horizontal gun 7, and the other second flow path 81 is a flow path for draining the cooling water that has flowed through the horizontal gun 7.

[0030] FIG. 3 is a cross-sectional view showing the structure of the tip portion of the horizontal gun 7 of the resistance welding apparatus 1 according to the present embodiment. In the figure, the shank holder 71 has an L-shaped configuration with a bent tip portion, and one flow path 74 is formed inside. A resin tube 75 is inserted into the flow path 74 of the shank holder 71. The length of the tube 75 is longer than that of the shank holder 71, and when the shank 15 is attached to the shank holder 71, a part thereof reaches inside the flow path 76 of the shank 15. The tube 75 is for flowing the cooling water sent from a cooling water circulation device (not shown) toward the shank 15 side. A resin tube 77 is inserted into the flow path 76 of the shank 15. The length of the tube 77 is longer than that of the shank 15, and when the electrode tip 16 is attached to the shank 15, a part thereof reaches inside the internal space 78 of the electrode tip 16.

[0031] The tube 77 inserted into the flow path 76 of the shank 15 has a smaller diameter than the tube 75 inserted into the flow path 74 of the shank holder 71 and can be inserted into the tube 75 on the shank holder 71 side. The tube 77 is for flowing the cooling water that has flowed through the tube 75 inserted into the shank holder 71 toward the electrode tip 16 side.

[0032] The electrode tip 16 is an electrode that pairs with the table electrode 10. One of the electrode tip 16 and the table electrode 10 is connected to one electrode of the welding transformer 11 (see FIG. 1), and the other is connected to the other electrode of the welding transformer 11.

[0033] Returning to FIG. 1, the pressing cylinder 8 is disposed on the upper surface side of the tip portion of the arm portion 5B. The pressing cylinder 8 receives the supply of compressed air during welding to pull up a chain (not shown) connected to the rear end portion of the horizontal gun 7, and rotates the horizontal gun 7 so that the tip end portion side of the horizontal gun 7 faces downward (toward the table electrode 10 side). At this time, the chain is pulled up so that a predetermined pressing force is applied to the material to be welded (not shown).

[0034] The table electrode 10 is formed in a rectangular flat plate shape made of a conductive metal material (mainly "copper") and is disposed below the horizontal gun 7. The gantry 12 is a table used for welding work, and the table electrode 10 is placed thereon. The welding transformer 11 supplies power to the horizontal gun 7, with one electrode connected to the table electrode 10 and the other electrode connected to the power supply cable 9. The welding transformer 11 is disposed within the gantry 12.

[0035] Next, the power supply cable 9 will be described. FIG. 4 is a cross-sectional view showing the overall structure of the power supply cable 9 of the resistance welding apparatus 1 according to the present embodiment. FIG. 5 is a cross-sectional view showing the structure of one end side portion of the power supply cable 9. Further, FIG. 6 is a cross-sectional view showing the structure of the other end side portion of the power supply cable 9. In FIG. 4, the power supply cable 9 includes a first connection terminal 200, a second connection terminal 220, a conductive member 240, a first tubular member 260, a second tubular member 280, a first connection block 300, and a second connection block 320.

[0036] In FIG. 5, the first connection terminal 200 is made of a conductive metal material (mainly "copper"), and includes a flange portion 202 for connecting to the first connection block 300 and a main body portion 203 that is integrated with the flange portion 202 and has a sawtooth-shaped surface portion on the outer peripheral side. The flange portion 202 has a cylindrical shape with a larger diameter than the main body portion 203. The main body portion 203 has a cylindrical shape extending in the central axis direction from the flange portion 202. Through holes 201 penetrating in the direction of the common central axis are formed in the flange portion 202 and the main body portion 203, respectively. The diameter of the through hole 201 is slightly larger on the flange portion 202 side. Since the through holes 201 are formed in both the flange portion 202 and the main body portion 203, the shapes of both the flange portion 202 and the main body portion 203 are cylindrical.

[0037] The teeth formed on the main body portion 203 of the first connection terminal 200 have the tips of the teeth facing in the direction opposite to the insertion direction of the second tubular member 280 into the first connection terminal 200, so that the second tubular member 280 cannot easily come off from the first connection terminal 200. Further, a groove (hereinafter referred to as a "circumferential groove") 204 having an axial direction as a depth direction is formed in the circumferential direction on the opening side (the side opposite to the flange portion 202) of the main body portion 203 of the first connection terminal 200. The cross-sectional shape of the circumferential groove 204 is tapered so as to become narrower as it approaches the flange portion 202 It is like this. In addition to making the cross-sectional shape of the circumferential groove 204 tapered, for example, it may be U-shaped.

[0038] On the other hand, the second connection terminal 220 is made of the same shape and the same metal material as the first connection terminal 200. That is, in FIG. 6, the second connection terminal 220 is made of a conductive metal material (mainly "copper"), and includes a flange portion 222 for connecting to the second connection block 320 and a main body portion 223 that is integrated with the flange portion 222 and has a sawtooth-shaped surface portion on the outer peripheral side. The flange portion 222 has a cylindrical shape with a larger diameter than the main body portion 223, and the main body portion 223 has a cylindrical shape extending in the central axis direction from the flange portion 222. Through holes 221 penetrating in the direction of the common central axis are formed in the flange portion 222 and the main body portion 223, respectively. The through hole 221 is on the flange portion 222 sideis Some have become larger. Since the through holes 221 are formed in both the flange portion 222 and the main body portion 223, the shapes of both the flange portion 222 and the main body portion 223 are cylindrical.

[0039] The teeth formed on the main body portion 223 of the second connection terminal 220 have the tips thereof facing in a direction opposite to the insertion direction of the second tubular member 280 into the second connection terminal 220, so that the second tubular member 280 cannot easily come off from the second connection terminal 220. Further, on the main body portion 223 of the second connection terminal 220, a groove (hereinafter referred to as a "circumferential groove") 224 having an axial direction as a depth direction is formed in the circumferential direction on the opening side. The cross-sectional shape of the circumferential groove 224 is a tapered shape that becomes narrower as it approaches the flange portion 222. It is like this. In addition to making the cross-sectional shape of the circumferential groove 224 tapered, for example, it may be U-shaped.

[0040] In FIGS. 4 to 6, the conductive member 240 is made of a metal material (mainly "copper") having conductivity and flexibility. One end is connected to the main body portion 203 side of the first connection terminal 200, and the other end is connected to the main body portion 223 side of the second connection terminal 220. The conductive member 240 is composed of a plurality of copper wire bundles 240a (see FIG. 7). is Each copper wire bundle 240a 、 is formed by twisting a plurality of copper wires and has a circular cross-sectional shape. One end portion of each of the plurality of copper wire bundles 240a constituting the conductive member 240 is arranged along the circumferential groove 204 of the first connection terminal 200, and the other end portion of each of the plurality of copper wire bundles is arranged along the circumferential groove 224 of the second connection terminal 220. In this case, the plurality of copper wire bundles are arranged in the circumferential direction.

[0041] FIG. 7 is a cross-sectional view taken along the line A-A of FIG. 5. This figure shows the arrangement of the first connection terminal 200 and the second connection terminal 220 of the conductive member 240 in the power supply cable 9. As shown in this figure, one end of each copper wire bundle 240a is arranged along the circumferential direction with respect to the circumferential groove 204 of the first connection terminal 200. The other end of each copper wire bundle 240a is also arranged along the circumferential direction with respect to the circumferential groove 224 of the second connection terminal 220. In particular, one end and the other end of each copper wire bundle 240a are arranged at the same position with respect to the circumferential grooves 204 and 224. That is, when one end of the copper wire bundle 240a is arranged at the 12 o'clock position with respect to the circumferential groove 204, for example, the other end of the copper wire bundle 240a is arranged at the 12 o'clock position with respect to the circumferential groove 224. Similarly, when one end of the copper wire bundle 240a is arranged at the 3 o'clock position with respect to the circumferential groove 204, for example, the other end of the copper wire bundle 240a is arranged at the 3 o'clock position with respect to the circumferential groove 224. By arranging one end and the other end of the copper wire bundle 240a at the same position with respect to the circumferential grooves 204 and 224, the conductive member 240 has a substantially cylindrical shape.

[0042] Returning to FIGS. 4 to 6, the first tubular member 260 is made of a flexible resin material. One end portion passes through the through hole 201 from the main body portion 203 side of the first connection terminal 200 and reaches the inside of the first connection block 300, and the other end portion passes through the through hole 221 from the main body portion 223 of the second connection terminal 220 and reaches the inside of the second connection block 320.

[0043] The second tubular member 280 is made of a rubber material. One end is located on the flange portion 202 side of the first connection terminal 200, and the other end is located on the flange portion 222 side of the second connection terminal 220. The second tubular member 280 houses the conductive member 240, the first tubular member 260, and the cooling water. Since the shape of the conductive member 240 is substantially cylindrical, the cooling water can flow stably. That is, the cooling water can flow smoothly in the second tubular member 280. By allowing the cooling water to flow smoothly, the cooling efficiency can be improved.

[0044] In FIG. 5, the first connection block 300 is made of a conductive metal material (mainly "copper") and has a first hole 301, a second hole 302, a first opening 303, and a second opening 304. The first connection block 300 is connected to the flange portion 202 of the first connection terminal 200. In this case, for example, screws are used for the connection to the flange portion 202. The inner diameter of the first hole 301 is approximately the same as the inner diameter of the through hole 201 of the first connection terminal 200. The first hole 301 communicates with the through hole 201 of the first connection terminal 200. The inner diameter of the second hole 302 is smaller than the inner diameter of the first hole 301. The second hole 302 communicates with the first hole 301.

[0045] The first opening 303 communicates with the first hole 301, and the second opening 304 communicates with the second hole 302. The second hole 302 has an inner diameter slightly smaller than the outer diameter of the first tubular member 260 (that is, an inner diameter small enough to press-fit the first tubular member 260 into the second hole 302). Note that rubber O-rings 305 for preventing water leakage are arranged at the opening ends of the first opening 303 and the second opening 304, respectively. An O-ring 307 is also arranged between the first connection block 300 and the flange portion 202 of the first connection terminal 200.

[0046] The first opening 303 is the opening on the inflow side of the cooling water, and the cooling water that has passed through the flow path in the horizontal gun 7 flows in. Arrow Y2 indicates the direction of the flow. On the other hand, the second opening 304 is the opening on the outflow side of the cooling water, and the cooling water sent from a cooling water circulation device (not shown) flows out. Arrow Y1 indicates the direction of the flow.

[0047] In FIG. 6, the second connection block 320 is made of a conductive metal material, similar to the first connection block 300. Also, the size and shape are the same. The second connection block 320 has a third hole 321, a fourth hole 322, a third opening 323, and a fourth opening 324. The inner diameter of the third hole 321 is approximately the same as the inner diameter of the through hole 221 of the second connection terminal 220. The third hole 321 communicates with the through hole 221 of the second connection terminal 220. The inner diameter of the fourth hole 322 is smaller than the inner diameter of the third hole 321. The fourth hole 322 communicates with the third hole 321.

[0048] The third opening 323 communicates with the third hole 321, and the fourth opening 324 communicates with the fourth hole 322. The fourth hole 322 has an inner diameter slightly smaller than the outer diameter of the first tubular member 260 (that is, an inner diameter small enough to press-fit the first tubular member 260 into the fourth hole 322). Note that O-rings 305 for preventing water leakage are arranged at the opening ends of the third opening 323 and the fourth opening 324, respectively. An O-ring 307 is also arranged between the second connection block 320 and the flange portion 222 of the second connection terminal 220.

[0049] The third opening 323 is the opening on the outflow side of the cooling water, and the cooling water that has flowed into the first opening 303 of the first connection block 300 flows out. Arrow Y4 indicates the direction of the flow. On the other hand, the fourth opening 324 is the opening on the inflow side of the cooling water, and the cooling water sent from a cooling water circulation device (not shown) flows in. Arrow Y3 indicates the direction of the flow.

[0050] Thus, in the power supply cable 9, an annular circumferential groove 204 is formed in the main body 203 of the first connection terminal 200, and an annular circumferential groove 224 is formed in the main body 223 of the second connection terminal 220. On the other hand, the conductive member 240 connecting the main body 203 of the first connection terminal 200 and the main body 223 of the second connection terminal 220 is composed of a plurality of copper wire bundles 240a. One end of each copper wire bundle 240a is arranged along the circumferential direction in the circumferential groove 204 of the main body 203 of the first connection terminal 200 and brazed. The other end of each copper wire bundle 240a is arranged along the circumferential direction in the circumferential groove 224 of the main body 223 of the second connection terminal 220 so as to be in the same position with respect to the circumferential groove 224 as the case of the circumferential groove 204 of one end of each copper wire bundle 240a and brazed. Further, since the first tubular member 260 through which the cooling water sent from the cooling water circulation device flows is disposed through the first connection terminal 200 and the second connection terminal 220, the first tubular member 260 for flowing the cooling water sent from the cooling water circulation device to the horizontal gun 7 is accommodated in the power supply cable 9. Therefore, the total number of tubes and cables can be reduced, the operability of the horizontal gun 7 can be improved, and the cost for manufacturing the resistance welding device 1 can be reduced. Further, since the copper wire bundles 240a are arranged in alignment between the first connection terminal 200 and the second connection terminal 220, a smooth flow of the cooling water in the second tubular member 280 can be realized, and the cooling efficiency can be improved.

[0051] Next, a method for manufacturing the power supply cable 9 of the resistance welding device 1 according to the present embodiment will be described. FIG. 8 is a diagram for explaining a method for manufacturing the power supply cable 9. This method is a method used for manufacturing the resistance welding device 1 including the horizontal gun 7 having the first flow path 80 on the cooling water inflow side and the second flow path 81 on the cooling water outflow side.

[0052] (First step) A metal third tubular member 400, which has a total length longer than that of the second tubular member 280 and an outer diameter smaller than the outer diameter of the through hole 201 of the first connection terminal 200 and larger than the outer diameter of the first tubular member 260, is disposed between the first connection terminal 200 and the second connection terminal 220. Note that, in the first step, the first tubular member 260 is not used. The third tubular member 400 is used for passing the first tubular member 260 between the first connection terminal 200 and the second connection terminal 220 and for heat prevention when brazing the conductive member 240 to the first and second connection terminals 200 and 220.

[0053] (Second step) One end of each of a plurality of copper wire bundles 240a made of copper wires fabricated as the conductive member 240 is disposed in the circumferential groove 204 of the first connection terminal 200, and the other end of each is disposed in the circumferential groove 224 of the second connection terminal 220.

[0054] (Third step) The first tubular member 260 is inserted into the third tubular member 400.

[0055] (Fourth step) One end of each of the plurality of copper wire bundles 240a disposed in the circumferential groove 204 of the first connection terminal 200 is brazed to the first connection terminal 200, and the other end of each of the plurality of copper wire bundles 240a disposed in the circumferential groove 224 of the second connection terminal 220 is brazed to the second connection terminal 220.

[0056] Since the location becomes high temperature during brazing, the resin-made first tubular member 260 would melt if there were no metal-made third tubular member 400. However, by providing the third tubular member 400, it is possible to prevent the first tubular member 260 from being affected by the heat during brazing.

[0057] (Fifth step) The second tubular member 280 is disposed between the flange portion 202 of the first connection terminal 200 and the flange portion 222 of the second connection terminal 220.

[0058] The conductive member 240 is formed by a plurality of copper wire bundles 240a. These copper wire bundles 240a are arranged side by side in the circumferential direction between the first connection terminal 200 and the second connection terminal 220 so as to form a substantially cylindrical shape. By disposing the first tubular member 260 within the substantially cylindrical conductive member 240 thus formed, a stable flow of cooling water within the second tubular member 280 can be realized, and the cooling efficiency can be improved.

[0059] (Step 6) After the completion of the fifth step, the third tubular member 400 is removed. Since the conductive member 240 is brazed to the first and second connection terminals 200 and 220 and the first tubular member 260 is inserted, the third tubular member 400 becomes unnecessary. Therefore, the third tubular member 400 is removed.

[0060] In this method, compared with a method that requires two tubes and one power supply cable, only one power supply cable 9 is needed. Thus, the operability of the horizontal gun 7 can be improved, and the cost of manufacturing the resistance welding apparatus 1 can be reduced.

[0061] Next, a usage example of the resistance welding apparatus 1 according to the present embodiment will be described. When performing welding, for example, two steel plates are overlapped and placed on the table electrode 10. Thereafter, the tip portion of the horizontal gun 7 (the portion where the electrode tip 16 is attached) is applied to the upper steel plate. By performing an operation to start welding in this state, the pressurizing cylinder 8 starts to operate and the rear end portion of the horizontal gun 7 is pulled up. When the rear end portion of the horizontal gun 7 is pulled up, the tip end side of the horizontal gun 7 rotates downward and the electrode tip 16 comes into contact with the upper steel plate. In this case, the contact is made with a magnitude corresponding to the applied pressure. When the operation to start welding is performed, energization is performed simultaneously with pressurization, and welding of the two steel plates is performed.

[0062] Thus, according to the horizontal gun 7 of the resistance welding apparatus 1 according to this embodiment, in the second tubular member 280, a plurality of conductive members 240 are formed as a plurality of copper wire bundles 240a, and these copper wire bundles 240a are arranged side by side in the circumferential direction between the first connection terminal 200 and the second connection terminal 220 so as to form a substantially cylindrical shape, and the first tubular member 260 is arranged in the substantially cylindrical conductive member 240. Therefore, a stable flow of cooling water in the second tubular member 280 can be realized, and the cooling efficiency can be improved.

[0063] In addition, compared with the conventional one that requires two tubes 710, 720 and one power supply cable 730, only one power supply cable 9 is needed, so that the operability of the horizontal gun 7 can be improved, and the cost of manufacturing the resistance welding apparatus 1 can be reduced.

[0064] Although the present invention has been described with reference to specific embodiments, it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

Industrial Applicability

[0065] The present invention is suitable for a resistance welding apparatus including a welding gun that can move horizontally with respect to the apparatus main body and a table electrode formed in a substantially square flat plate shape.

Explanation of Reference Numerals

[0066] 1 Resistance welding apparatus 4 Support post 5 Arm 6 Gun bracket 7 Horizontal gun 7A Gun tip 7B Gun rear end 8 Pressing cylinder 9 Power supply cable 10 Table electrode 11 Welding transformer 12 Stand 15 Shank 16 Electrode tip 61 Shaft 71 Shank Holder 73 Handle 74, 76 Flow Path 75, 77 Tube 78 Internal Space 80 First Flow Path 81 Second Flow Path 200 First Connection Terminal 201 Through-Hole 202 Flange Portion 203 Body Portion 204, 224 Circumferential Groove 220 Second Connection Terminal 221 Through-Hole 222 Flange Portion 223 Body Portion 240 Conductive Member 240a Copper Wire Bundle 260 First Tubular Member 280 Second Tubular Member 300 First Connection Block 301 First Hole Portion 302 Second Hole Portion 303 First Opening 304 Second Opening 305, 307 O-Ring 320 Second Connection Block 321 Third Hole Portion 322 Fourth Hole Portion 323 Third Opening 324 Fourth Opening 400 Third Tubular Member

Claims

1. A power supply cable used in a resistance welding apparatus including a horizontal gun (71) having a first flow path (80) on the cooling water inflow side and a second flow path (81) on the cooling water outflow side, comprising a flange portion (202) and a main body portion (203) made of a conductive metal material, the flange portion having a cylindrical shape with a larger diameter than the main body portion, the main body portion having a cylindrical shape extending in the central axis direction from the flange portion, and a first connection terminal (200) formed with a through hole (201) penetrating through the central axis of the main body portion and the flange portion from the main body portion to the flange portion, a second connection terminal (220) having the same shape and made of the same metal material as the first connection terminal, a conductive member (240) made of a metal material having conductivity and flexibility, one end being connected to the main body portion of the first connection terminal and the other end being connected to the main body portion of the second connection terminal, a first tubular member (260) made of a resin material having flexibility, one end portion protruding from the main body portion of the first connection terminal through the through hole and beyond the flange portion of the first connection terminal, and the other end portion protruding from the main body portion of the second connection terminal through the through hole and beyond the flange portion of the second connection terminal, a second tubular member (280) made of a resin material having flexibility, one end portion being located on the flange portion side of the first connection terminal, the other end portion being located on the flange portion side of the second connection terminal, and accommodating the conductive member, the first tubular member, and the cooling water, and comprising, the conductive member is composed of a plurality of copper wire bundles, and a circumferential groove (204) with the axial direction as the depth direction is formed on the opening side of the main body portion of each of the first connection terminal and the second connection terminal. One end portion of each of the plurality of copper wire bundles serving as the conductive member is disposed in the circumferential groove of the first connection terminal, and the other end portion of each of the plurality of copper wire bundles serving as the conductive member is disposed in the circumferential groove (224) of the second connection terminal, the first tubular member is disposed in a substantially cylindrical space formed by the arrangement of the plurality of copper wire bundles between the first connection terminal and the second connection terminal, the flange portion side of the through hole of the first connection terminal communicates with the first flow path on the cooling water inflow side of the horizontal gun, and the portion side of the first tubular member protruding beyond the flange portion of the first connection terminal communicates with the second flow path on the cooling water outflow side of the horizontal gun, a power supply cable.

2. A first connection terminal (200) comprising a flange portion and a main body portion made of a conductive metal material, wherein the flange portion has a columnar shape with a larger diameter than the main body portion, the main body portion has a columnar shape extending in the central axis direction from the flange portion, through holes are formed in the flange portion and the main body portion, penetrating along the central axis of the main body portion and the flange portion from the main body portion to the flange portion, and a circumferential groove with an axial direction as the depth direction is formed at an end of the main body portion; a second connection terminal (220) having the same shape and made of the same metal material as the first connection terminal; a conductive member (240) made of a metal material having conductivity and flexibility, used for connecting the main body portion of the first connection terminal and the main body portion of the second connection terminal; a first tubular member (260) made of a flexible resin material, disposed through the through holes of the first connection terminal and the second connection terminal, for flowing cooling water to the horizontal gun side; and a second tubular member (280) made of a rubber material, disposed between the flange portion of the first connection terminal and the flange portion of the second connection terminal. For a horizontal gun having a first flow path on the cooling water inflow side and a second flow path on the cooling water outflow side, a method for manufacturing a power supply cable for a resistance welding device, wherein the flange portion side of the through hole of the first connection terminal is communicated with the first flow path on the cooling water inflow side of the horizontal gun, and the protruding portion side of the first tubular member from the flange portion of the first connection terminal is communicated with the second flow path on the cooling water outflow side of the horizontal gun, A first step of disposing a third tubular member made of metal, having a total length longer than that of the second tubular member and an outer diameter smaller than the outer diameter of the through hole of the first connection terminal and larger than the outer diameter of the first tubular member, between the first connection terminal and the second connection terminal; A second step of disposing one end of each of a plurality of copper wire bundles made of a plurality of copper wires produced as the conductive member in the circumferential groove of the first connection terminal, and disposing the other end of each in the circumferential groove of the second connection terminal; A third step of inserting the first tubular member into the third tubular member; A fourth step of brazing one end of each of the plurality of copper wire bundles disposed in the circumferential groove of the first connection terminal to the first connection terminal, and brazing the other end of each of the plurality of copper wire bundles disposed in the circumferential groove of the second connection terminal to the second connection terminal; A fifth step of disposing the second tubular member between the flange portion of the first connection terminal and the flange portion of the second connection terminal; A sixth step of extracting the third tubular member after completion of the fifth step; A method for manufacturing a power supply cable comprising the steps.

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