Welding wire feeding device

Abstract

The present invention provides a welding wire feeding device that has a configuration to avoid the formation of unexpected current paths in the drive motor. [Solution] This welding wire feeding device 1 is a welding wire feeding device that feeds welding wire 4 to a welding site, and comprises a housing 100, a power supply block 811, a wire feeding path WF, and a nozzle holder 801 housed inside the housing 100, and when viewed along the direction in which the welding wire 4 is fed, the power supply block 811, the wire feeding path WF, and the nozzle holder 801 are arranged in this order, and the power supply block 811 and the nozzle holder 801 are electrically connected by a first relay wire E1, a second relay wire E2, a third relay wire E3, and a fourth relay wire E4.

Description

Technical Field

[0001] The present invention relates to a welding wire feeding device.

Background Art

[0002] When welding is performed using a robot hand, a welding wire feeding device having a welding nozzle attached to the tip side is used to feed the welding wire to the welded portion.

[0003] Such a welding wire feeding device is disclosed in Japanese Patent Application Laid-Open No. 2023-093903 (Patent Document 1), Japanese Patent Application Laid-Open No. 2023-093902 (Patent Document 2), Japanese Patent Application Laid-Open No. 2023-093901 (Patent Document 3), and the like.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above-described welding wire feeding device, drive rollers and pressure rollers for sandwiching the welding wire are provided to feed the welding wire to the welding nozzle side. The drive rollers are rotationally controlled by a drive motor provided inside the welding wire feeding device.

[0006] It is necessary to transmit a welding current to the welding nozzle. This welding current is transmitted to the welding nozzle through the robot hand and relayed by the welding wire feeding device.

[0007] During the feeding of welding wire, the surface of the welding wire is scraped by the surfaces of the drive roller and pressure roller, causing welding wire debris to accumulate around the drive roller and pressure roller. Since welding wire debris is conductive, there are concerns that this debris could cause unexpected current paths to form, leading to welding current flowing into the drive motor (short circuit).

[0008] In addition to short circuits caused by welding wire debris, there is a risk that unexpected current paths may be formed in the drive motor, causing welding current to flow into the drive motor (short circuit).

[0009] This disclosure is made to solve the above-mentioned problems and aims to provide a welding wire feeding device that has a configuration to avoid the formation of unexpected current paths in the drive motor. [Means for solving the problem]

[0010] [1] The welding wire feeding device of the present disclosure is a welding wire feeding device for feeding a welding wire to a workpiece, comprising a housing, a power supply block, a wire feeding path, and a nozzle holder housed inside the housing, wherein the power supply block, the wire feeding path, and the nozzle holder are arranged in this order when viewed along the direction in which the welding wire is fed, and the power supply block and the nozzle holder are electrically connected by one or more relay wires.

[0011] [2] The welding wire feeding device according to [1], wherein the wire feeding path, when viewed along the direction in which the welding wire is fed, includes an inlet wire guide, a welding wire feeding mechanism, an outlet wire guide, a coil spring, a bearing for a swing shaft, and a swing shaft.

[0012] [3] The welding wire feeding device according to [2], wherein the bearing for the swing shaft includes a flange that protrudes radially outward, the flange has one or more recesses that are recessed radially inward, and the relay wire is routed inside the housing so as to pass through the recesses. [Effects of the Invention]

[0013] The welding wire feeding device of this disclosure provides a welding wire feeding device that has a configuration to avoid the formation of unexpected current paths in the drive motor. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows the overall configuration of a welding nozzle and welding wire feeding device mounted on a robot arm. [Figure 2] This is a perspective view showing the overall configuration of the welding wire feeding device according to the embodiment. [Figure 3] This is a side view showing the overall configuration of the welding wire feeding device according to the embodiment. [Figure 4] This is a side view of the embodiment with the opening / closing cover in the open position. [Figure 5] This is a first perspective view of the embodiment with the opening / closing cover in the open position. [Figure 6] This is a second perspective view of the embodiment with the opening / closing cover in the open position. [Figure 7] This is a perspective cross-sectional view showing the internal configuration of the welding wire feeding device according to the embodiment. [Figure 8] This is a first perspective view showing the internal configuration of the welding wire feeding device according to the embodiment. [Figure 9] This is a second perspective view showing the internal configuration of the welding wire feeding device according to the embodiment. [Figure 10] This is a third perspective view showing the internal configuration of the welding wire feeding device according to the embodiment. [Figure 11] This is a fourth perspective view showing the internal configuration of the welding wire feeding device according to the embodiment.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, the welding wire feeding device of the present embodiment will be described with reference to the drawings. In the embodiments described below, when referring to the number, amount, etc., unless otherwise specified, the scope of the present invention is not necessarily limited to such number, amount, etc. The same parts and corresponding parts are given the same reference numerals, and redundant descriptions may not be repeated. It is initially planned to use the configurations in the embodiments in appropriate combinations.

[0016] (Welding Wire Feeding Device 1) Referring to FIGS. 1 to 3, the welding wire feeding device 1 of the present embodiment will be described. In the following description, the downstream side in the direction (X direction) in which the welding wire 4 is fed may be referred to as the front side, and the upstream side may be referred to as the rear side. When the X direction is referred to as the front-rear direction, the direction intersecting this front-rear direction may be referred to as the lateral direction.

[0017] Referring to FIG. 1, a welding nozzle 2 for feeding a welding wire to the welded portion is attached to the front side of the welding wire feeding device 1. A robot arm 3 is connected to the rear side of the welding wire feeding device 1.

[0018] Referring to FIGS. 2 and 3, the welding wire feeding device 1 is a device for feeding the welding wire 4 to the welded portion. The welding wire feeding device 1 includes a housing 100 provided so that the welding wire 4 can be inserted from the rear side toward the front end side, and a housing region R1 (see FIG. 4) that houses a welding wire feeding mechanism that abuts against the welding wire 4 and feeds the welding wire 4 to the welded portion. The housing 100 constitutes the outer shell of the welding wire feeding device 1 including a hood 101 and a motor cover 102 described later.

[0019] A nozzle holder 801 for attaching the welding nozzle 2 is provided on the front side of the housing 100. A robot arm mounting portion 110 for connecting to the robot arm 3 is provided on the rear side of the housing 100.

[0020] The housing 100 includes an opening / closing cover 130 that covers the containment area R1. The opening / closing cover 130 has a cover rotation support portion 132 on its rear side, which has an opening / closing central axis a1 extending in a direction intersecting the direction in which the welding wire 4 is fed. The opening / closing cover 130 is provided on the housing 100 so as to be able to open and close with the opening / closing central axis a1 as the opening / closing center. A locking mechanism 140A is provided on the front side of the opening / closing cover 130 between it and the housing 100. The opening / closing cover 130 may be made of a transparent material so that the containment area R1 is visible from the outside, or it may be made of an opaque material so that the containment area R1 is not visible from the outside.

[0021] In this way, by positioning the opening / closing central axis a1 of the opening / closing cover 130 on the rear side of the opening / closing cover 130, the storage area R1 can be opened up significantly, and the lateral side of the bottom surface 111, which will be described later, can be opened up significantly to the outside.

[0022] Referring to Figures 4 to 6, the state in which the opening / closing cover 130 is opened to the rear of the housing 100 will be described.

[0023] The containment area R1 includes a flat bottom surface 111, and the welding wire feeding mechanism M1 is placed on the bottom surface 111.

[0024] The containment area R1 is positioned at a predetermined distance from the bottom surface 111 in the X direction from which the welding wire 4 is fed, and includes a first wall 112 located on the upstream (rear) side in the X direction from which the welding wire 4 is fed, and a second wall 113 located on the downstream (front) side in the X direction from which the welding wire 4 is fed. The bottom surface 111 is open to the outside in the lateral direction (perpendicular to the plane of the paper in Figure 4) that intersects with the direction from which the welding wire 4 is fed.

[0025] The shape of the recessed storage area R1, defined in a side view by the bottom surface 111, the first wall 112, and the second wall 113, is matched to the shape of the cover edge 134 of the opening / closing cover 130. As a result, when the opening / closing cover 130 is closed to the housing 100, the storage area R1 can be completely covered by the opening / closing cover 130.

[0026] The locking mechanism 140A, provided between the opening / closing cover 130 and the housing 100, locks the opening / closing cover 130 to the housing 100 when a locking claw 131t provided in a recess 131s of the opening / closing cover 130 engages with the locking member 140.

[0027] A first inclined wall 112c is provided between the bottom surface 111 and the first wall 112, extending in a direction intersecting the X direction from which the welding wire 4 is fed. A second inclined wall 113c is provided between the bottom surface 111 and the second wall 113, extending in a direction intersecting the X direction from which the welding wire 4 is fed.

[0028] The welding wire feeding mechanism M1, positioned on the flat bottom surface 111, includes at least a drive roller 400 that contacts the welding wire 4, and a pressure roller 320 that, together with the drive roller 400, grips the welding wire 4. The drive roller 400 is driven by a drive mechanism provided on the bottom surface 111 and inside the housing 100. The pressure roller 320 is provided on a pressure arm 300. The pressure arm 300 includes a rotating arm 310. One end of the rotating arm 310 is provided with an arm rotation support shaft 330 that rotatably supports the rotating arm 310 relative to the bottom surface 111. The support rotation axis c1 of the arm rotation support shaft 330 is positioned substantially perpendicular to the bottom surface 111.

[0029] The rotating arm 310 is equipped with the aforementioned pressure roller 320 in its central position, and a lock groove 310m is provided on the side of the rotating arm 310 opposite the arm rotation support shaft 330, flanking the pressure roller 320. This lock groove 310m is used to lock the welding wire 4 in place between the pressure roller 320 and the drive roller 400.

[0030] A lock pin 200, including an adjustment screw 210 that engages with a lock groove 310m, is provided on the first wall 112. The lock pin 200 includes the adjustment screw 210 and a spring case 220 that provides elastic force in the axial direction of the adjustment screw 210. The spring case 220 is rotatably supported on the first wall 112 with respect to a case rotation support 230 provided on the first wall 112. The case rotation axis b1 is an axis that extends perpendicular to the first wall 112 and is the same as the X direction in which the welding wire 4 is fed.

[0031] An inlet wire guide 500 is provided on the first wall 112, and an outlet wire guide 600 is provided on the second wall 113. The welding wire 4 is fed from the inlet wire guide 500 toward the outlet wire guide 600. The welding wire 4 is held between the pressure roller 320 and the drive roller 400 in the region between the inlet wire guide 500 and the outlet wire guide 600.

[0032] Figure 5 shows the state in which the pressure arm 300 is locked by the lock pin 200. The clamping force on the welding wire 4 by the pressure roller 320 and the drive roller 400 can be changed by adjusting the elastic force of the spring provided in the spring case 220.

[0033] Figure 6 shows the state in which the lock on the pressurizing arm 300 is released by the lock pin 200. By rotating the adjustment screw 210 along the case rotation axis b1, the adjustment screw 210 is released from the lock groove 310m. As a result, the rotating arm 310 becomes rotatable along the support rotation axis c1 of the arm rotation support shaft 330.

[0034] (Internal configuration of welding wire feeding device 1) Referring to Figure 7, the internal configuration of the welding wire feeding device 1 will be described. A plug body 810 is provided on the robot arm mounting portion 110 side of the first wall 112 via a first insulating wall 115. A power supply block 811 is fixed to the plug body 810. A first wire passage 810a is provided in the plug body 810, and a second wire passage 115a is provided in the first insulating wall 115. The first wire passage 810a and the second wire passage 115a are in communication with the inlet wire guide 500.

[0035] A drive motor 700 that drives the drive roller 400 is located in the area of ​​the bottom surface 111 opposite to the housing area R1. A second insulating wall 116 is located between the bottom surface 111 and the drive motor 700. The drive motor 700 is covered by a motor cover 102, and the other internal equipment is completely covered by a hood 101.

[0036] As viewed from the outlet wire guide 600 mounted on the second wall 113, the coil spring 806, swing shaft 804, and nozzle holder 801 are arranged in this order. A spring guide 805 is mounted on the outer circumferential surface of the coil spring 806. The side of the swing shaft 804 facing the coil spring 806 is fixed to the swing shaft 804 so that it can swing by a swing shaft bearing 807.

[0037] The welding wire 4, fed out from the outlet wire guide 600, passes through the inside of the coil spring 806, the swing shaft 804, and the nozzle holder 801.

[0038] The nozzle holder 801 side of the swing shaft 804 is fitted with a cylindrical insulating ring 803 and an insulating bush 802.

[0039] When viewed along the X-direction from which the welding wire 4 is fed, a wire feeding path WF is formed by at least an inlet wire guide 500, a welding wire feeding mechanism M1, an outlet wire guide 600, a coil spring 806, a bearing 807 for a swing shaft, and a swing shaft 804, from which the welding wire 4 is fed. A plug body 810 and a power supply block 811 are positioned on the inlet side of the wire feeding path WF for the welding wire 4, and a nozzle holder 801 is positioned on the outlet side of the wire feeding path WF for the welding wire 4.

[0040] When an external force is applied to the welding nozzle 2 to which the nozzle holder 801 is attached, the nozzle holder 801 and the swing shaft 804 swing. At this time, the swing shaft 804 absorbs the impact by compressing the coil spring 806 (shock absorber mechanism). This impact is detected by a sensor (not shown), and control is performed to stop the welding wire feeding device 1.

[0041] (Path for transmitting welding current) Referring to Figures 8 to 11, the path for supplying welding current to the welding nozzle 2 via the welding wire feeder 1 will be described. To facilitate the explanation of the internal mechanism, the hood 101 and motor cover 102 are shown in a partially transparent state.

[0042] As shown in Figure 8, the welding wire feeding device 1 of this embodiment relays the current supplied from the robot arm 3 via a power supply block 811. One end of the first relay wire E1, the second relay wire E2, the third relay wire E3, and the fourth relay wire E4 are connected to the power supply block 811. The other ends of the first relay wire E1, the second relay wire E2, the third relay wire E3, and the fourth relay wire E4 are connected to a nozzle holder 801. The relay wires are not limited to wires suitable for power transmission, but strand wires, for example, may be used.

[0043] This embodiment describes a case using four relay wires, but the number of wires used can be appropriately selected according to the amount of current to be transmitted, and it is preferable to use one or two or more relay wires.

[0044] Of the first relay wire E1, second relay wire E2, third relay wire E3, and fourth relay wire E4, which are routed through the gap between the hood 101 and one side of the drive motor 700, the third relay wire E3 and fourth relay wire E4 are routed toward the front side shown in the figures, as shown in Figures 9 and 10, and then connected to the nozzle holder 801. The first relay wire E1 and second relay wire E2 are routed toward the opposite side shown in the figures, as shown in Figures 9 and 11, and then connected to the nozzle holder 801.

[0045] The swing shaft bearing 807 of the swing shaft 804 is provided with a flange 807f that protrudes radially outward. This flange 807f is provided with curved first recess 807a, second recess 807b, and third recess 807c that are recessed radially inward.

[0046] In the circumferential direction of the flange 807f, the first recess 807a and the second recess 807b are located on the opposite side from the opening / closing cover 130, and the third recess 807c is located closer to the opening / closing cover 130 than the first recess 807a and the second recess 807b.

[0047] The number of recesses provided in flange 807f can be selected as appropriate, and it is preferable to have one or two or more recesses.

[0048] To facilitate the wiring of the relay wires inside the hood 101, the first relay wire E1 and the second relay wire E2 are routed inside the hood 101 so as to pass through the first recess 807a, and the third relay wire E3 and the fourth relay wire E4 are routed so as to pass through the second recess 807b. A gas pipe G1 for supplying welding gas from the robot arm 3 toward the welding nozzle 2 is routed through the third recess 807c.

[0049] As described above, according to the welding wire feeding device 1 of this embodiment, a power supply block 811 is provided near the robot arm mounting part 110 connected to the robot arm 3, and welding current is supplied to the nozzle holder 801 by a relay wire. As a result, it is possible to route the relay wire inside the housing 100 so as to bypass the drive motor 700. This makes it possible to avoid the formation of an unexpected power supply path to the drive motor 700.

[0050] Furthermore, the welding wire feeding device 1 described above allows for flexible wiring of the intermediate wire even within the complex internal structure of the housing 100, where wiring space is limited, by using an intermediate wire. As a result, the assembly work of the welding wire feeding device 1 is made more efficient, and the parts replacement work during maintenance is also made more efficient. Moreover, since commercially available products are used for the intermediate wire, there is no increase in the cost of the welding wire feeding device 1.

[0051] In conventional designs, a busbar was provided to bridge a movable shock absorber mechanism, thereby supplying welding current to the nozzle holder 801. However, in this configuration, the welding current path came close to the drive motor 700, making it highly likely that an unexpected current path would be formed in the drive motor 700. Furthermore, the busbar required the use of a highly conductive material (such as brass or copper), making the busbar itself an expensive component.

[0052] However, the welding wire feeding device 1 described above makes it possible to solve the problems of the conventional structure described above.

[0053] Although a welding wire feeding device has been described above in the embodiments, the embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims, and all modifications are made within the meaning and scope of equivalents of the claims. [Explanation of symbols]

[0054] 1 Welding wire feeder, 2 Welding nozzle, 3 Robot arm, 4 Welding wire, 100 Housing, 101 Hood, 102 Motor cover, 110 Robot arm mounting section, 111 Bottom surface, 112 First wall, 112c First inclined wall, 113 Second wall, 113c Second inclined wall, 114 Edge of containment area, 115 First insulating wall, 115a Second wire passage, 116 Second insulating wall, 130 Opening / closing cover, 131s Recess, 131t Locking claw, 132 Cover rotation support section, 134 Cover edge, 135,136 Locking claw, 140 Locking member, 140A Locking mechanism, 200 Locking pin, 210 Adjustment screw, 220 Spring case, 230 Case rotation support section, 300 Pressurizing arm, 310 Rotating arm, 310m Locking groove, 320 Pressure roller, 330 Arm rotation support shaft, 400 Drive roller, 500 Inlet wire guide, 600 Outlet wire guide, 700 Drive motor, 801 Nozzle holder, 802 Insulating bush, 803 Insulating ring, 804 Swing shaft, 805 Spring guide, 806 Coil spring, 807 Bearing for swing shaft, 807a First recess, 807b Second recess, 807c Third recess, 807f Flange, 810 Plug body, 810a First wire passage, 811 Power supply block, E1 First relay wire, E2 Second relay wire, E3 Third relay wire, E4 Fourth relay wire, G1 Gas piping, M1 Welding wire feeding mechanism, R1 Storage area, WF Welding wire feeding path, a1 Opening / closing central shaft, b1 Case rotation shaft, c1 Support rotation shaft.

Claims

1. A welding wire feeding device that feeds welding wire to the area to be welded, The casing and The following components are housed inside the aforementioned housing: a power supply block, a wire feeding path, and a nozzle holder. Equipped with, When viewed along the direction in which the welding wire is fed, the power supply block, the wire feeding path, and the nozzle holder are arranged in this order. The power supply block and the nozzle holder are electrically connected by one or more relay wires. Welding wire feeding device.

2. When viewed along the direction in which the welding wire is fed, the wire feeding path includes an inlet wire guide, a welding wire feeding mechanism, an outlet wire guide, a coil spring, a bearing for a swing shaft, and a swing shaft. The welding wire feeding device according to claim 1.

3. The aforementioned swing shaft bearing includes a flange that protrudes radially outward, The flange has one or more recesses that are recessed radially inward. The relay wire is routed inside the housing so as to pass through the recess. The welding wire feeding device according to claim 2.

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