JP2016087628A - Welding torch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding torch which is suitable for resolving a trouble in a liner inserted in a welding cable due to the extension or twisting of the welding cable, while an installation structure is simplified.SOLUTION: A welding torch includes: a torch body; a welding cable 200 which is shaped in a longitudinal cylinder, is attached to a wire feeder side at a base end portion, and is attached with the torch body at a tip end portion; a liner 300 for guiding a welding wire which is inserted in the welding cable 200, is attached to the base end portion of the welding cable 200 at a base end portion, and attached to the torch body at a tip end portion; and locking means which is provided at an attaching part of the base end portion of the liner 300 to the base end portion of the welding cable 200, prevents the axial movement of the liner 300 to the welding cable 200, and accepts the relative rotations of the liner 300 and the welding cable 200.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a welding torch including a welding cable, a liner inserted in the welding cable, and a torch body connected to the tip of the welding cable.

  For example, in consumable electrode gas shielded arc welding, automatic welding using a welding robot or a traveling carriage or semi-automatic welding operated by an operator is employed. At the time of welding operations such as automatic welding, a welding wire is sent out from the wire feeder toward the welding torch, and electric power and shielding gas are supplied to the welding torch.

  The welding torch includes, for example, a welding cable, a liner, and a torch body (see, for example, Patent Document 1). The welded cable has a configuration in which an insulator is coated on a cylindrical conductor portion, and the cylindrical conductor portion has a stranded structure of a number of fine metal wires. The base end portion of the welding cable is attached to the wire feeder side, and the torch body is attached to the distal end portion of the welding cable. A liner guides the welding wire sent out from the wire feeder, and is inserted in the welding cable. The base end portion of the liner is fixedly attached to the base end portion of the welding cable. The liner includes, for example, a cylindrical metal fitting on the base end side and a spiral coil portion connected to the metal fitting. The metal fitting and the coil portion are connected and fixed by means such as crimping, and the metal fitting is fixed to the proximal end portion of the welding cable. The tip of the liner is inserted into the torch body and reaches a power feed chip provided on the tip side of the torch body. In some cases, the welding torch and the welding cable are distinguished and referred to. When these are distinguished and called, the above-described torch body is called a welding torch. In addition, the welding cable may be represented by another name such as a conduit cable.

  In automatic welding, the torch body is mounted on a welding robot or traveling carriage. Regarding the welding cable, it is necessary to follow the movement of the welding robot and the traveling carriage, and the length of the welding cable is relatively long. In the welding operation, the welding cable repeats operations such as bending and twisting. If it does so, in the welding cable, twist of a metal fine wire may return and the full length of a welding cable may be extended. For the liner inserted in the welding cable, the base end is fixed, but if the tip is not fixed, the liner tip is retracted from the power feed tip by the length of the weld cable. There will be a gap between the liner tip. When the gap is generated in this way, there is a possibility that the feeding of the welding wire is unstable and the welding quality is deteriorated.

  On the other hand, in the said patent document 1, the structure which fixes the front-end | tip part of a liner to a torch main body is disclosed. When the liner tip is fixed to the torch body in this way, the liner tip can be prevented from separating from the power feed tip, and the above-described problems caused by the total length of the welding cable extending can be eliminated. it can.

  However, the welding cable itself may be twisted due to the return of twisting of the thin metal wire of the welding cable. As described above, when both ends (base end portion and tip end portion) of the liner are fixed, when the welding cable is twisted, a twisting force acts on the liner. If it does so, the connection part of the metal fitting of a liner and a coil part may fracture | rupture, and there existed a possibility of causing the feeding failure of a welding wire.

  Also, the liner is a component with a relatively high exchange frequency because it easily deposits the plating powder of the welding wire inserted through the liner. Therefore, it is desirable to improve the replacement workability by making the attachment portion of the liner to the welding cable and the torch body relatively simple.

Japanese Patent No. 4739825

  The present invention has been conceived under such circumstances, and for the liner inserted in the welding cable, while simplifying the mounting structure, the disadvantage caused by the expansion and twisting of the welding cable is eliminated. It is an object of the present invention to provide a welding torch suitable for solving the problem.

  In order to solve the above problems, the present invention employs the following technical means.

  The welding torch provided by the present invention has a torch main body and a longitudinal cylindrical shape, a welding cable in which a base end portion is attached to the wire feeder side and the tip portion is attached to the torch main body, A liner for guiding a welding wire, inserted into the welding cable, having a proximal end attached to the proximal end of the welding cable and a distal end attached to the torch body; and the welding The liner with respect to the welding cable or the torch body, provided at at least one of the attachment part of the base part of the liner to the base part of the cable and the attachment part of the tip part of the liner to the torch body Locking means for preventing the axial movement of the liner and allowing relative rotation between the liner and the welding cable or the torch body, It is characterized in that it comprises.

  In a preferred embodiment, the locking means includes a radially outward annular groove provided in the liner, and a locking member provided in the torch body or the welding cable and capable of entering the annular groove. , Including.

  In a preferred embodiment, the locking member is a screw member that can move forward and backward along the radial direction of the annular groove with respect to the annular groove.

  In a preferred embodiment, the locking means has a retraction preventing mechanism that prevents the locking member from retreating from the annular groove.

  In a preferred embodiment, the receding prevention mechanism is configured such that the engagement length of the locking member into the annular groove when the locking member is attached is the locking member and the locking member in the attached state. The structure which becomes larger than the clearance gap with the contact part contact | abutted when a locking member reverse | retreats is included.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is an external view which shows an example of the welding torch which concerns on this invention. It is a principal part perspective view which shows the base end part of a welding cable and a liner. It is a principal part longitudinal cross-sectional view which shows the base end part of a welding cable and a liner, (a) is the state before attaching a locking member, (b) shows the state which attached the locking member. It is a principal part longitudinal cross-sectional view which shows an example of the state which attached the base end part of the welding cable to the wire feeder side. It is sectional drawing which follows VV of FIG. It is a principal part longitudinal cross-sectional view around a torch main body. It is a principal part longitudinal cross-sectional view which shows the other structural example of a latching means.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an external view showing an example of a welding torch according to the present invention. The welding torch 100 of this embodiment includes a welding cable 200, a liner 300, and a torch body 400. The welding torch 100 is used, for example, in a welding apparatus for performing consumable electrode gas shielded arc welding, and is suitable for automatic welding using a traveling carriage.

  The welding cable 200 guides the welding wire sent out from a wire feeder (not shown) to the torch body 200, and has a longitudinal cylindrical shape as a whole. When the welding torch 100 is used for automatic welding, the length of the welding cable 200 is relatively long. Although the intermediate portion is omitted in FIG. 1, the total length of the welding cable 200 is, for example, about 6 m to 10 m.

  The welding cable 200 includes a cable body 210, holders 220 and 230, and a connection member 240. Although detailed illustration explanation is omitted, the cable body 210 has a configuration in which the cylindrical conductor portion is covered with an insulating cover, and the cylindrical conductor portion has a stranded wire structure of a number of fine metal wires.

  The connection member 240 is connected and fixed to one end of the cable body 210. The connecting portion is held by the holder 220. The connection member 240 is a portion corresponding to the “base end portion of the welding cable” in the present invention.

  As shown in FIGS. 2 and 3, the connection member 240 has a substantially cylindrical shape, and supports a mounting bracket 310 of a liner 300 described later. More specifically, as shown in FIG. 3, the base end portion 241 of the connection member 240 is formed with a mounting hole 242 having a larger inner diameter than other portions, and the mounting bracket 310 of the liner 300 is attached to the base end 241. The mounting hole 242 is inserted with almost no gap. As shown in FIG. 2, the base end portion 241 of the connection member 240 is shaped such that a part of the outer peripheral portion is cut off, and has a flat surface 243. As shown in FIG. 3A, a screw hole 245 that communicates in the radial direction from the flat surface 243 to the mounting hole 242 is formed in the base end portion 241.

  As shown in FIG. 1, the holder 230 is provided at the other end of the cable main body 210 and holds the torch main body 400. Although details will be described later, in the present embodiment, the connection member 240 is connected to a cylindrical wire outlet 600 provided in the wire feeder (see FIG. 4).

  Note that the welding cable 200 also plays a role of supplying electric power and shielding gas to the torch body 400. As shown in FIG. 1, a hose 261 for supplying a shielding gas and power supply, switch, and control cables 262, 263, and 264 are connected to appropriate positions of the welding cable 200. .

  The liner 300 guides the welding wire delivered from the wire feeder to the torch body 400 and is inserted into the welding cable 200. As shown in FIG. 3, the liner 300 includes a cylindrical mounting bracket 310 on the proximal end side and a coil portion 320 connected to the mounting bracket 310. The coil part 320 has a configuration in which a metal wire is wound in a spiral shape and has a substantially cylindrical shape. The proximal end portion of the coil portion 320 is connected and fixed to the mounting bracket 310 by appropriate means such as crimping. In addition, the outer periphery of the coil part 320 is covered with the resin cover 321 in the range of a predetermined length in the axial direction from the part that contacts the mounting bracket 310. Although detailed illustration explanation is omitted, the space between the cable body 210 and the coil part 320 functions as a passage for flowing the shield gas.

  The mounting bracket 310 has a substantially cylindrical shape and has a larger outer diameter than the coil part 320. The mounting bracket 310 is a portion that is supported by the connection member 240 when the liner 300 is mounted. The outer diameter of the mounting bracket 310 is slightly smaller than the inner diameter of the connection member 240 (mounting hole 242). When the liner 300 is mounted, the distal end of the coil portion 320 is inserted from the proximal end of the connection member 240, and the attachment fitting 310 is inserted into the attachment hole 242 of the connection member 240.

  A radially outward annular groove 311 is formed at an appropriate position of the mounting bracket 310. When the liner 300 is mounted, the annular groove 311 and the screw hole 245 of the connecting member 240 are in a position overlapping each other when viewed in the radial direction. A set bolt 500 is attached to the screw hole 245. The set bolt 500 has, for example, a head portion 510 and a screw shaft portion 520, and is a so-called hexagon socket head bolt. As understood from FIGS. 3A and 3B, when the screw shaft portion 520 is screwed into the screw hole 245 and the head 510 is turned, the set bolt 500 is moved along the radial direction of the annular groove 311. Move forward and backward. As shown in FIG. 3B, the head 510 is in pressure contact with the flat surface 243 of the connection member 240 in a state where the set bolt 500 is tightened. At this time, the screw shaft portion 520 has entered the annular groove 311, the tip of the screw shaft portion 520 is not in contact with the bottom portion of the annular groove 311, and there is a slight gap between them. Here, even if an axial force (left-right direction in the figure) acts on the liner 300, the set bolt 500 (screw shaft portion 520) is locked by the connecting member 240 (side wall portion constituting the annular groove 311), The axial movement of the base end portion of the liner 300 relative to the mounting bracket 310 (base end portion of the welding cable 200) is prevented.

  On the other hand, since there is a gap between the tip of the screw shaft portion 520 and the bottom of the annular groove 311, relative rotation between the liner 300 and the connecting member 240 (welding cable 200) is allowed. The mounting bracket 310 (liner 300) having the annular groove 311, the connecting member 240 (welding cable 200) having the screw hole 245, and the set bolt 500 constitute locking means. The set bolt 500 corresponds to a “locking member” in the present invention.

  As shown in FIG. 3B, when the set bolt 500 is tightened (when the head 510 is in pressure contact with the flat surface 243), the length of the screw shaft portion 520 entering the annular groove 311 is constant. In the present embodiment, a set bolt 500 having a small head 510 is used, the significance of which will be described later.

  Connection member 240 (base end portion of welding cable 200) is connected to, for example, a wire outlet of a wire feeder. 4 and 5 show an example of a state in which the connection member 240 is connected to a wire outlet 600 of a wire feeder (not shown). The wire outlet 600 includes a connection hole 610 having an inner diameter that is substantially the same as the outer diameter of the connection member 240, and the connection member 240 is inserted into the connection hole 610.

  As shown in FIG. 5, since the head 510 of the set bolt 500 is thin, the head 510 is accommodated in the connection hole 610 without interfering with the inner surface of the connection hole 610. At this time, a slight gap is provided between the head 510 and the inner surface of the connection hole 610. The entry length L1 of the set bolt 500 (screw shaft portion 520) into the annular groove 311 is between the head portion 510 and a portion (contact portion) where the head portion 510 can abut on the inner surface of the connection hole 610. It is larger than the gap L2. As an example of these dimensions, the entry length L1 is about 3 mm, the gap L2 is about 0.5 mm, and the entry length L1 is sufficiently larger than the gap L2. In the state shown in FIG. 5, even if the set bolt 500 is loosened and retracted from the annular groove 311, the head 510 of the set bolt 500 immediately hits the inner surface (contact portion) of the connection hole 610, and the set bolt 500 The slack stops. Thus, even if the set bolt 500 is loosened, the approach length L1 and the clearance L2 are in the above relationship, and therefore the approach length L1 of the set bolt 500 (screw shaft portion 520) to the annular groove 311 is Sufficiently secured, the mounting bracket 310 (liner 300) relative to the connection member 240 (welding cable 200) is prevented from moving in the axial direction. Such a connection structure of the connection member 240 to the wire outlet 600 constitutes a receding prevention mechanism.

  Note that a retaining bolt 620 is provided at an appropriate position of the wire outlet 600. The retaining bolt 620 is attached so as to cross a radially outward portion of the connection hole 610 in the circumferential direction. Since the retaining bolt 620 engages with the step 246 of the connecting member 240, the connecting member 240 is prevented from coming out of the connecting hole 610 (wire outlet 600).

  As shown in FIG. 1, the torch body 400 is attached to the distal end portion of the welding cable 200 (cable body 210). As shown in FIG. 6, the torch body 400 includes a torch body 410, a chip body 420, an insulating member 430, a power feeding chip 440, and a nozzle 450. The tip of the liner 300 (coil portion 320) extends to the power feed tip 440 while being inserted into the tip body 420. A set screw 460 is attached to an appropriate position of the chip body 420. The set screw 460 is screwed into a screw hole formed along the radial direction of the chip body 420. The set screw 460 has a shape with a sharp tip, and is a so-called hexagon socket set screw. When the set screw 460 is tightened, the tip of the set screw 460 bites into the outer surface of the coil part 320, and the tip of the liner 300 (coil part 320) is fixed to the torch body 400. The insulating member 430 is externally fitted to the chip body 420, and immediately hits the insulating member 430 even if the set screw 460 is loosened. With such a configuration, the insulating member 430 functions as a set screw 460 to prevent the set screw 460 from being loosened, and the fixing state of the front end portion of the liner 300 (coil portion 320) to the torch body 400 is appropriately maintained.

  Next, the operation of the welding torch 100 according to the above-described embodiment will be described.

  When automatic welding is performed using the welding torch 100, the welding cable 200 repeats operations such as bending and twisting. Then, in the welding cable 200, the twist of the thin metal wire of the cylindrical conductor portion may return, and the entire length of the welding cable 200 may be extended, or the welding cable 200 itself may be twisted.

  According to the welding torch 100 of the present embodiment, the front end portion of the liner 300 inserted in the welding cable 200 is fixed to the torch main body 400. Regarding the base end portion (mounting bracket 310) of the liner 300, as described above, the connection bolt 240 (base end of the welded cable 200) is configured by the set bolt 500 attached to the connection member 240 entering the annular groove 311 of the liner 300. In the axial direction of the base end portion of the liner 300 relative to the portion) is prevented. Therefore, since the liner 300 follows the elongation of the welding cable 200, it is possible to eliminate problems caused by the welding cable 200 being elongated.

  Further, as described above, relative rotation between the base end portion (mounting bracket 310) of the liner 300 and the connection member 240 (welding cable 200) is allowed. Thereby, even if the welding cable 200 is twisted, the twisting force does not act on the liner 300. Accordingly, it is possible to avoid problems such as breakage of the liner 300 due to the twist of the welding cable 200.

  Further, the above-described locking structure at the base end portion of the liner 300 can be realized by a relatively simple structure in which the set bolt 500 and the annular groove 311 are provided. Further, when the liner 300 is replaced, it can be replaced by removing the set bolt 500 and the set screw 460, so that the replacement workability is excellent.

  When the set bolt 500 is tightened, the set length of the set bolt 500 (screw shaft portion 520) into the annular groove 311 is constant. As a result, the locking by the set bolt 500 is accurately performed, and the liner 300 is prevented from being accidentally pulled out.

  As described above with reference to FIG. 5 and the like, in this embodiment, the set bolt 500 is prevented from retreating from the annular groove 311 even if the set bolt 500 is loosened. Thereby, the locking by the set bolt 500 is more reliably performed.

  In the above-described embodiment with reference to FIGS. 1 to 5, the case where the locking means is provided on the proximal end side of the liner 300 has been described. However, FIG. 7 is the case where the locking means is provided on the distal end side of the liner 300. Is shown.

  FIG. 7 shows a cross-section of the main parts of the chip body 420 and the insulating member 430 in the torch body 400. As shown in FIG. 7, a locking fitting 330 is externally fitted and fixed to the front end portion of the liner 300 (coil portion 320) by appropriate means such as crimping. The locking metal fitting 330 is formed with a radially outward annular groove 331. The annular groove 331 and the screw hole 421 formed in the chip body 420 are in a position overlapping each other when viewed in the radial direction.

  A set bolt 500 is attached to the screw hole 421. The set bolt 500 has the same configuration as the set bolt 500 shown in FIGS. 2 to 5 and the like, and has a head portion 510 and a screw shaft portion 520. When the screw shaft portion 520 is screwed into the screw hole 421 and the head 510 is rotated, the set bolt 500 moves forward and backward along the radial direction of the annular groove 331. In a state where the set bolt 500 is tightened, the head portion 510 is in pressure contact with the outer peripheral surface of the chip body 420. At this time, the screw shaft portion 520 has entered the annular groove 331, and the tip of the screw shaft portion 520 and the bottom of the annular groove 331 are not in contact with each other, and there is a slight gap therebetween. Here, even if an axial force (left-right direction in the figure) acts on the liner 300, the set bolt 500 (screw shaft portion 520) is locked by the locking bracket 330 (side wall portion constituting the annular groove 331). Thus, the axial movement of the tip of the liner 300 with respect to the tip body 420 (torch body 400) is prevented.

  On the other hand, since there is a gap between the tip of the screw shaft portion 520 and the bottom of the annular groove 331, relative rotation between the liner 300 and the tip body 420 (torch body 400) is allowed. When the set bolt 500 is tightened (the head 510 is in pressure contact with the outer peripheral surface of the chip body 420), the length of the screw shaft portion 520 entering the annular groove 331 is constant.

  As shown in FIG. 7, a slight gap is provided between the head 510 and the inner surface of the insulating member 430 when the set bolt 500 is tightened. The entry length L3 of the set bolt 500 (screw shaft portion 520) into the annular groove 331 is between the head portion 510 and a portion (contact portion) where the head portion 510 can abut on the inner surface of the insulating member 430. It is larger than the gap L4. In the state shown in FIG. 7, even if the set bolt 500 is loosened and retracted from the annular groove 331, the head 510 of the set bolt 500 immediately hits the inner surface (contact portion) of the insulating member 430, and the set bolt 500 Looseness stops. Thus, even if the set bolt 500 is loosened, the approach length L3 and the gap L4 are in the above relationship, and therefore, the approach length L3 of the set bolt 500 (screw shaft portion 520) to the annular groove 331 is It is sufficiently ensured that the locking metal fitting 330 (liner 300) is prevented from moving in the axial direction with respect to the chip body 420 (torch body 400). Such a locking structure of the front end portion of the liner 300 constitutes a receding prevention mechanism. 7 has the same effect as the locking structure of the base end portion of the liner 300 described above with reference to FIGS. 1 to 5.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to the above-described embodiments, and all modifications within the scope of the matters described in the claims are all within the scope of the present invention. Is included.

  In the above embodiment, the configuration in which the locking means is provided at the proximal end portion of the liner and the configuration in which the locking means is provided at the distal end portion of the liner have been described. Each part) may be provided with locking means.

  The specific configuration of the locking means is not limited to the configuration of the above embodiment using the set bolt 500. Various modifications are possible as long as they prevent the liner from moving in the axial direction with respect to the welding cable or torch body and allow relative rotation between the liner and the welding cable or torch body.

  In the said embodiment, although the liner comprised the coil part, it may replace with this and may use the liner provided with resin-made tubes, for example.

100 welding torch 200 welding cable 210 cable body 220, 230 holder 240 connecting member 241 base end 242 mounting hole 243 flat surface 245 screw hole 246 step 261 hose 262, 263, 264 cable 300 liner 310 mounting bracket 311 annular groove 320 coil 321 Resin cover 330 Locking metal fitting 331 Annular groove 400 Torch body 410 Torch body 420 Chip body 421 Screw hole 430 Insulating member 440 Power supply tip 450 Nozzle 460 Set screw 500 Set bolt (locking member)
510 Head 520 Screw shaft portion 600 Wire outlet 610 Connection hole 620 Retaining bolt

Claims (5)

The torch body,
A welded cable having a longitudinal cylindrical shape, a base end portion attached to the wire feeder side, and a tip end portion to which the torch body is attached;
A liner for guiding a welding wire, inserted into the welding cable, having a proximal end attached to the proximal end of the welding cable and a distal end attached to the torch body;
Provided in at least one of the attachment portion of the base end portion of the liner with respect to the base end portion of the weld cable and the attachment portion of the tip end portion of the liner with respect to the torch body, and with respect to the welding cable or the torch body Locking means for preventing the liner from moving in the axial direction and allowing relative rotation between the liner and the welding cable or the torch body;
A welding torch comprising: a welding torch.   The locking means includes a radially outward annular groove provided in the liner, and a locking member provided in the torch body or the welding cable and capable of entering the annular groove. The welding torch according to claim 1.   The welding torch according to claim 2, wherein the locking member is a screw member capable of moving forward and backward along the radial direction of the annular groove with respect to the annular groove.   The welding torch according to claim 2 or 3, wherein the locking means has a retraction preventing mechanism for preventing the locking member from retreating from the annular groove.   The retraction prevention mechanism is configured such that when the locking member enters the annular groove in a state in which the locking member is attached, the locking member in the attached state and the locking member are retracted. The welding torch according to claim 4, wherein the welding torch includes a configuration that is larger than a gap between the contact portion and the contact portion.

Images