JP6536339B2 - Welding torch, welding apparatus, and method of manufacturing welding product - Google Patents

Description

  The present invention relates to a welding torch, a welding apparatus using the same, and a method of manufacturing a welded product.

DESCRIPTION OF RELATED ART Conventionally, the arc welding utilized as a technique which joins the joining target object (henceforth a "work") which consists of metal materials is known. TIG (Tungsten Inert Gas) welding, which is a type of arc welding, supplies an inert gas such as argon gas as a shielding gas around an electrode made of tungsten, and an arc plasma generated by arc discharge between a work and the electrode The workpiece is melted and bonded by the heat of
The welding apparatus described in Patent Document 1 performs welding of a work by generating arc discharge between the electrode and the work while spraying shield gas toward the work from the inside of the cylindrically formed electrode. It is.

JP, 2006-51521, A

  However, in the welding device described in Patent Document 1, the shield gas injected from the opening on the work side of the electrode diffuses along the work. As a result, the arc plasma has a shape that spreads in the region where the shield gas is present. Therefore, in this welding device, it is considered that penetration of welding to a work becomes shallow or distortion occurs in the work.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a welding torch capable of controlling the shape of arc plasma, a welding apparatus using the same, and a method of manufacturing a welded product. I assume.

The welding torch of the first invention comprises a nozzle body (20), an electrode (12), a supply passage (50) and a suction passage (60). The electrode passes through the inside of the cylindrical nozzle body and is exposed at the tip (21) of the nozzle body. The supply passage is provided in the nozzle body, and jets and supplies shield gas from the tip of the nozzle body. The suction passage is provided radially inward of the supply passage in the nozzle body and around the electrode, and sucks shield gas from the tip end side of the nozzle body. In the suction passage, the minimum width (F) of the flow passage cross-section in the direction orthogonal to the direction in which the work and the electrode move relative to each other (hereinafter referred to as "relative movement direction A") Equal to or greater than the minimum width (G). Therefore, the suction force of the shield gas by the suction passage is such that the suction force in the direction orthogonal to the relative movement direction A is the same as or larger than the suction force in the relative movement direction A. Therefore, the shape of the arc plasma formed between the work and the electrode is a substantially circular shape having a small diameter or a substantially elliptical shape having a major axis in the relative movement direction A. As a result, since the arc plasma is densified at the welding portion of the workpiece, the welding can be deeply melted into the workpiece.
In one aspect of the first aspect of the invention, the suction port (65) of the suction passage provided at the tip of the nozzle body has a distance (B) between the inner walls in a direction orthogonal to the direction in which the work and the electrode relatively move. The shape is longer than the distance (C) between the inner walls in the direction in which the work and the electrode move relative to each other .
In another aspect of the first aspect of the present invention, the cross-sectional area (D) of the suction port (65) of the suction channel provided at the tip of the nozzle body is the suction channel located on the back side of the nozzle body than the suction port. It is smaller than the flow passage cross-sectional area (E).

A second invention is an invention of a welding apparatus provided with the welding torch of the first invention. The welding apparatus includes, in addition to the welding torch, an installation unit (6), a power supply unit (7), a gas supply source (8) and a gas discharge mechanism (9). The welding torch is installed such that the electrode is directed to the welding portion of the work installed in the installation portion. The power supply unit supplies power to the electrodes of the welding torch. The gas supply source supplies shield gas to the supply path of the welding torch. The gas discharge mechanism discharges shield gas from the suction passage by applying negative pressure to the suction passage of the welding torch.
Thereby, the 2nd invention enables deep penetration of welding to a work like the 1st invention.

The third invention is an invention of a method of manufacturing a welded product. This manufacturing method includes a work installation process (S1), a torch installation process (S2), an injection process (S3), a suction process (S4) and a welding (S5) process. In the work installation step, the work is installed in the installation unit of the welding apparatus. In the torch installation step, the welding torch is installed in the welding apparatus. In the injection step, shielding gas is injected and supplied toward the central axis side of the nozzle body in the space between the tip of the nozzle body and the work from the supply passage provided in the nozzle body of the welding torch. In the suction step, shield gas is sucked from the tip end side of the nozzle body by a suction passage provided radially inward of the supply passage in the nozzle body and around the electrode. At this time, the suction force of the shield gas in the direction orthogonal to the direction in which the work and the electrode move relative to each other is larger than the suction force in the direction in which the work and the electrode move relative to each other. In the welding process, the workpiece and the electrode move relative to each other while arcing from the electrode to the workpiece.
Thus, the shield gas injected and supplied from the supply passage in the injection step is sucked into the suction passage in the suction step. Therefore, the shape of the arc plasma formed between the work and the electrode is narrowed. Therefore, since the arc plasma is densified at the welding portion of the workpiece, the welding can be deeply embedded in the workpiece.

It is a block diagram of the welding apparatus by 1st Embodiment of this invention. It is sectional drawing of the welding torch of 1st Embodiment. It is a top view of the welding torch tip in the III direction of FIG. It is sectional drawing of the welding torch tip in the IV-IV line of FIG. It is sectional drawing of the welding torch tip in the VV line | wire of FIG. It is an enlarged view of VI part of FIG. It is sectional drawing of the VII-VII line of FIG. 2 and FIG. It is a schematic diagram of the arc plasma by the welding torch of 1st Embodiment. It is a schematic diagram of the arc plasma by the welding torch of 1st Embodiment. It is a flowchart of the manufacturing method of the welding product which used the welding apparatus. It is a top view of the welding torch tip by a 2nd embodiment of the present invention. It is a top view of the welding torch tip by a 3rd embodiment of the present invention. It is a top view of the welding torch tip by a 4th embodiment of the present invention. It is a schematic diagram of the arc plasma by the welding torch of 4th Embodiment. It is a top view of the welding torch tip by a 5th embodiment of the present invention. FIG. 14 is a plan view of a welding torch tip according to a sixth embodiment of the present invention. FIG. 21 is a cross-sectional view of a welding torch tip according to a seventh embodiment of the present invention. It is a schematic diagram of the welding torch of a comparative example, and arc plasma by it.

Hereinafter, a plurality of embodiments of the present invention will be described based on the drawings.
First Embodiment
A first embodiment of the present invention is shown in FIGS. The welding device 1 according to the first embodiment joins together the connection points 4 of two work pieces 2 and 3 made of metal by arc welding.
As shown in FIG. 1, the welding apparatus 1 includes a base 5, an installation unit 6, a power supply unit 7, a gas supply source 8, a gas discharge mechanism 9, a welding torch 10 and the like.
The works 2 and 3 are installed in an installation unit 6 provided on the base 5. The base 5 is provided with a support 11 for supporting the welding torch 10. The welding torch 10 is provided such that an electrode 12 of the welding torch 10 is directed to a position where two workpieces 2 and 3 are welded. The workpieces 2 and 3 and the welding torch 10 can be moved relative to each other in the direction in which the connection points 4 of the two workpieces 2 and 3 extend by driving the installation portion 6 or the support portion 11. Thereby, when welding the connection location 4 of the two works 2 and 3 by the welding torch 10, the location where the welding is performed moves in the direction in which the connection location 4 of the two works 2 and 3 extends.

In the power supply unit 7, the wiring 16 extending from one of the positive electrode or the negative electrode is electrically connected to the electrode 12 provided in the welding torch 10, and the wiring 17 extending from the other of the positive electrode or the negative electrode is electrically Connected. The power supply unit 7 supplies power to the electrode 12 and the works 2 and 3 to give a predetermined potential difference to the electrodes 12 and the works 2 and 3.
The gas supply source 8 supplies a shield gas made of argon gas to the pipe connection port 51 of the supply passage provided in the welding torch 10 through the pipe 13.
The gas discharge mechanism 9 is, for example, a compressor, and supplies air to the air pipe connection port 63 of the gas passage provided in the welding torch 10 through the pipe 14.
The control unit 15 is configured of a microcomputer and the like. The control unit 15 controls each part of the welding apparatus 1 such as the relative moving speed of the works 2 and 3 and the welding torch 10 or the electric power supplied from the power source 7 to the electrodes 12 and the works 2 and 3.

Next, the configuration of the welding torch 10 and the function and effect thereof will be described.
As shown in FIG. 2, the welding torch 10 includes a nozzle body 20, a guide member 30, an electrode gripping portion 40, an electrode 12, a supply passage 50, a suction passage 60, a gas passage 61, an orifice 62 and the like. The respective components such as the nozzle body 20, the guide member 30, and the electrode gripping portion 40 provided in the welding torch 10 can be formed by, for example, a metal 3D printer. A metal 3D printer has, for example, a curved space inward by a powder sintering method in which three-dimensional modeling is performed by irradiating a laser onto a flat fine metal powder and sintering layer by layer and repeating this process. Parts of various shapes can be formed.

  The nozzle body 20 is formed in a tubular shape, and has a nozzle portion 22 and a rectangular parallelepiped base end portion 23 from the tip end 21 side in the axial direction. The nozzle portion 22 and the base end portion 23 are integrally formed. The nozzle body 20 has an axial hole 24 in which the guide member 30 can be inserted and in which a suction passage 60 is formed. The axial hole 24 is formed in the order of the throttle hole 28, the small diameter hole 25, the tapered hole 26 and the large diameter hole 27 from the side of the tip 21 in the axial direction.

The guide member 30 has a small diameter portion 31, a tapered portion 32 and a large diameter portion 33 from the tip end 21 side of the nozzle body 20. The small diameter portion 31 and the large diameter portion 33 are cylindrical. The outer diameter of the small diameter portion 31 is smaller than the outer diameter of the large diameter portion 33. Further, the tapered portion 32 connects the small diameter portion 31 and the large diameter portion 33. In the guide member 30, a part of the large diameter portion 33, the tapered portion 32 and the small diameter portion 31 are provided inside the axial hole 24 of the nozzle main body 20.
The guide member 30 also has a first flange 34 and a second flange 35 extending radially outward from the large diameter portion 33. The first flange portion 34 of the guide member 30 and the proximal end portion 23 of the nozzle body 20 are fixed by bolts 36.
The guide member 30 has a hole 37 at its center through which the electrode 12 passes. The guide member 30 surrounds the outer periphery of the electrode 12 and positions the electrode 12.

The electrode gripping portion 40 is provided on the opposite side to the nozzle body 20 of the guide member 30. The third flange portion 41 provided in the electrode gripping portion 40 and the second flange portion 35 of the guide member 30 are fixed by bolts 42. The electrode gripping portion 40 can grip the electrode 12 and can send the electrode 12 toward the tip portion 21 side of the nozzle main body 20 when the tip of the electrode 12 is exhausted. An electrode cap 43 is provided on the side opposite to the nozzle body 20 of the electrode gripping portion 40.
The electrode 12 is formed in a rod shape, for example, of tungsten. The electrode 12 is gripped by the electrode gripping portion 40, passes through a central hole 37 of the guide member 30, and is exposed to the tip portion 21 of the nozzle body 20.

The supply passage 50 is provided inside the nozzle body 20. The supply passage 50 has a pipe connection port 51 at the proximal end 23 of the nozzle body 20 and an injection port 52 at the distal end 21 of the nozzle body 20. A shield gas is supplied to the pipe connection port 51 from the gas supply source 8 through the pipe 13. As shown in FIG. 3, in the present embodiment, four elliptical injection ports 52 are provided around the electrode 12 at the distal end portion 21 of the nozzle body 20.
In FIG. 3, when welding the workpieces 2 and 3 using the welding torch 10, the direction in which the welding torch 10 moves relative to the workpieces 2 and 3 is indicated by an arrow A. In the following description, this direction is referred to as a relative movement direction A.
The two injection ports 52 are arranged in the relative movement direction A and provided at symmetrical positions with the electrode 12 interposed therebetween. Further, the other two injection ports 52 are arranged in a direction perpendicular to the relative movement direction A, and are provided at positions symmetrical with respect to the electrode 12.

  As shown in FIG. 2, the supply passage 50 changes its direction from the pipe connection port 51 to the tip portion 21 side of the nozzle main body 20 and extends in parallel with the axis of the nozzle portion 22. And an inclined passage 54 communicating with the port 52. As shown in FIGS. 4 and 5, the inclined passage 54 is inclined from the base end 23 side of the nozzle body 20 toward the tip end 21 side toward the central axis O of the nozzle body 20. Thus, the supply passage 50 injects and supplies shield gas from the injection port 52 toward the central axis O of the nozzle body 20 in the space between the tip portion 21 of the nozzle body 20 and the workpieces 2 and 3. It is possible. In addition, the inclined passage 54 is curved in a circular arc shape protruding outward in the radial direction from the proximal end 23 side of the nozzle main body 20 to the distal end portion 21 side. Furthermore, the inclined passage 54 goes from the base end 23 side of the nozzle main body 20 to the tip end 21 side, and the flow passage cross-sectional area gradually decreases. Thus, the supply passage 50 can reduce the fluid resistance of the shield gas and can increase the injection pressure of the shield gas.

The suction passage 60 is formed between the inner wall of the axial hole 24 of the nozzle body 20 and the outer wall of the guide member 30. That is, the suction passage 60 is provided radially inward of the supply passage 50 in the nozzle body 20 and around the electrode 12.
Further, as shown in FIGS. 2 and 6, a gas passage 61 is provided at the proximal end 23 of the nozzle body 20. The gas passage 61 has an air pipe connection port 63 on one side, and the other side 66 is open to the atmosphere. Air is supplied to the air pipe connection port 63 from the compressor as the gas discharge mechanism 9 through the pipe 14. As a result, as shown by arrow H in FIG. 6, air having a predetermined pressure flows through the gas passage 61.

  As shown in FIGS. 6 and 7, an orifice 62 is provided at a position where the suction passage 60 and the gas passage 61 communicate with each other. That is, the suction passage 60 and the gas passage 61 are in communication via the orifice 62. Further, the suction passage 60 has a cylindrical tapered flow passage 64 toward the orifice 62 and the flow passage cross-sectional area gradually decreases. Thereby, when the gas flows in the gas passage 61, the orifice 62 becomes negative pressure, and the shield gas is sucked from the tip portion 21 side of the nozzle main body 20 through the suction passage 60 as shown by arrow I in FIG.

  As shown in FIG. 3, the suction port 65 of the suction passage 60 is provided at the distal end portion 21 of the nozzle body 20. The suction port 65 has a shape in which the distance B between the inner walls in the direction orthogonal to the relative movement direction A is longer than the distance C between the inner walls in the relative movement direction A. On the other hand, the electrode 12 exposed from the suction port 65 is cylindrical. Therefore, in the suction passage 60, the minimum width F (see FIG. 4) of the flow channel cross section in the direction orthogonal to the relative movement direction A is larger than the minimum width G (see FIG. 5) of the flow channel cross section in the relative movement direction A. Therefore, the suction force of the shield gas in the direction orthogonal to the relative movement direction A is larger than the suction force of the shield gas in the relative movement direction A.

  Further, as shown in FIG. 4, the cross-sectional area D of the suction port 65 of the suction passage 60 is smaller than the flow channel cross-sectional area E of the suction passage 60 located on the back side of the suction port 65. Thus, the suction passage 60 can increase the flow velocity of the shield gas drawn from the space between the tip 21 of the nozzle body 20 and the work 2, 3 to the suction port 65. Arrows J in FIGS. 4 and 5 indicate the flow of shield gas that is supplied to the tip portion 21 of the nozzle main body 20 from the supply passage 50 and drawn into the suction passage 60.

FIGS. 4, 5, 8 and 9 show schematic views of the arc plasma 70 when welding is performed using the welding torch 10 of the present embodiment.
In the present embodiment, since the suction force of the shield gas in the direction orthogonal to the relative movement direction A is larger than the suction force of the shield gas in the relative movement direction A, as shown by the arrow 71 in FIGS. It is compressed relatively large in the direction orthogonal to the relative movement direction A, and has a substantially elliptical shape having a major axis in the relative movement direction A. Therefore, the shape of the arc plasma 70 is also compressed in the direction orthogonal to the relative movement direction A to be densified, and becomes a substantially elliptical shape extended in the relative movement direction A. Therefore, in the welding device 1 of the present embodiment, deep melting of the base material melting portion 73 into the works 2 and 3 is possible. Moreover, distortion of the workpieces 2 and 3 can be suppressed.

  Here, FIG. 18 shows a schematic view of the arc plasma 80 when welding is performed using the welding torch 100 of the comparative example. The welding torch 100 of the comparative example is configured not to include the suction passage. Further, the welding torch 100 of the comparative example is configured to inject the shield gas from the supply passage 500 perpendicularly to the works 2 and 3. In this case, as shown by the arrow 81 in FIG. 18, the shield gas injected from the supply passage 500 toward the workpieces 2 and 3 turns radially outward in the vicinity of the workpieces 2 and 3. Spread along. Therefore, the arc plasma 80 has a shape that spreads in the region where the shield gas is present. Therefore, in the welding apparatus 100 of the comparative example, since the width W of the arc plasma 80 is wide and the energy density is small, the penetration of the base material melting portion 73 into the works 2 and 3 becomes shallow or wide for the works 2 and 3 It is considered that distortion occurs in the range.

On the other hand, as shown in FIG. 4, FIG. 5, FIG. 8 and FIG. 9, the arc plasma 70 at the time of welding using the welding torch 10 of this embodiment is perpendicular to the relative movement direction A. It is compressed and becomes a substantially elliptical shape having a major axis in the relative movement direction A. In addition, the broken line 80 of FIG.4, FIG.5, FIG.8 and FIG. 9 shows typically the arc plasma of the workpieces 2 and 3 at the time of welding using the welding torch 100 of a comparative example.
Here, in the welding portion in FIG. 9, the base material temperature rising portion 72, the base material melting portion 73, and the base material cooling portion 74 are sequentially taken from the front side in the direction in which the electrode 12 moves relative to the workpieces 2 and 3. In this case, in the welding using the welding torch 10 of the present embodiment, the length of the base material melting portion 73 is longer than the welding using the welding torch 100 of the comparative example, so It can blend in.

Next, a method of manufacturing a welded product using the welding apparatus 1 of the present embodiment will be described with reference to FIG.
This manufacturing method includes a work installation process S1, a torch installation process S2, an injection process S3, a suction process S4, and a welding process S5. In the manufacturing method, the work installation step S1 and the torch installation step S2 may be reversed in order or may be performed simultaneously. Moreover, in this manufacturing method, the injection step S3, the suction step S4, and the welding step S5 are performed simultaneously.

In the workpiece installation step S1, the workpieces 2 and 3 are installed in the installation portion 6 of the welding apparatus 1 (see FIG. 1).
In the torch installation step S2, the welding torch 10 is installed such that the electrode 12 is directed to the welding portion of the work pieces 2 and 3.
Subsequently, in the injection step S3, the central axis O of the nozzle body 20 in the space between the tip portion 21 of the nozzle body 20 and the workpieces 2 and 3 from the supply passage 50 provided in the nozzle body 20 of the welding torch 10 The shield gas is injected toward the side (see FIGS. 4 and 5).

In the suction step S4, the shield gas is sucked from the tip portion 21 side of the nozzle body 20 by the suction passage 60 provided radially inward of the supply passage 50 in the nozzle body 20 and around the electrode 12. At this time, in the welding torch 10 of the present embodiment, the suction force of the shield gas in the relative movement direction A is larger than the suction force of the shield gas in the relative movement direction A due to the above-described configuration.
Then, in the welding step S5, the workpieces 2, 3 and the electrode 12 are relatively moved while arcing from the electrode 12 to the workpieces 2, 3. As a result, the connection points 4 of the two workpieces 2 and 3 are welded and joined in order in the relative movement direction A.

The first embodiment described above has the following effects.
(1) In the suction passage 60 provided in the welding torch 10 of the first embodiment, the minimum width F of the flow passage cross section in the direction orthogonal to the relative movement direction A is larger than the minimum width G of the flow passage cross section in the relative movement direction A . Therefore, the shape of the arc plasma 70 formed between the workpieces 2 and 3 and the electrode 12 has a substantially elliptical shape having a major axis in the relative movement direction A. Therefore, since the arc plasma 70 is densified at the welding portion of the workpieces 2 and 3, the welding can be deeply embedded in the workpieces 2 and 3.

(2) In the first embodiment, in the suction port 65 of the suction passage 60, the distance B between the inner walls in the direction orthogonal to the relative movement direction A is longer than the distance C between the inner walls in the relative movement direction A .
Thereby, for example, when the cylindrical electrode 12 is used, the minimum width F of the flow path cross section in the direction orthogonal to the relative movement direction A can be made larger than the minimum width G of the flow path cross section in the relative movement direction A .

(3) In the first embodiment, the cross-sectional area D of the suction port 65 is smaller than the flow channel cross-sectional area E of the suction passage 60 located on the back side of the nozzle main body 20 than the suction port 65.
As a result, it is possible to increase the flow velocity of the shield gas drawn into the suction port 65 from the space between the tip portion 21 of the nozzle body 20 and the workpieces 2 and 3. Therefore, the shape of the arc plasma 70 can be narrowed.

(4) In the first embodiment, the orifice 62 is provided at a position where the suction passage 60 and the gas passage 61 communicate with each other.
As a result, by causing the gas to flow through the gas passage 61, the orifice 62 has a negative pressure, and the shield gas is discharged from the suction passage 60 to the gas passage 61. Therefore, it is possible to discharge the shield gas from the suction passage 60 by using only the compressor without using, for example, a vacuum pump as the gas discharge mechanism 9. Therefore, since the welding torch 10 can reduce the inner diameter of the suction passage 60 and the gas passage 61, the size of the welding torch 10 can be reduced. In addition, the size of the welding apparatus 1 provided with the welding torch 10 can also be reduced.

(5) In the first embodiment, the suction passage 60 has the cylindrical tapered flow passage 64 toward the orifice 62 and the flow passage cross-sectional area gradually decreases.
This reduces the fluid resistance of the shield gas flowing from the suction passage 60 to the orifice 62. Therefore, it is possible to increase the flow rate of the shield gas discharged from the suction passage 60 through the orifice 62 to the gas passage 61. Therefore, the flow velocity of the shield gas sucked into the suction passage 60 from the space between the tip portion 21 of the nozzle body 20 and the workpieces 2 and 3 can be increased.

(6) In the first embodiment, the suction passage 60 and the orifice 62 are formed between the inner wall of the axial hole 24 of the nozzle body 20 and the outer wall of the guide member 30.
Thus, the shapes of the suction passage 60 and the orifice 62 can be easily formed by the shape of the inner wall of the nozzle body 20 and the shape of the outer wall of the guide member 30.

(7) In the first embodiment, the inclined passage 54 of the supply passage 50 is inclined from the base end 23 side of the nozzle body 20 toward the tip end 21 toward the central axis O of the nozzle body 20.
Thus, the supply passage 50 can inject and supply a shield gas toward the arc plasma 70 formed between the workpieces 2 and 3 and the electrode 12. Therefore, the shape of the arc plasma 70 can be narrowed.

(8) In the first embodiment, the inclined passage 54 of the supply passage 50 is curved in the shape of a circular arc convex radially outward from the base end 23 side to the tip end 21 side of the nozzle body 20.
Thereby, it is possible to reduce the fluid resistance of the shield gas flowing through the supply passage 50. Therefore, the pressure of the arc plasma 70 injected from the supply passage 50 can be increased, and the shape of the arc plasma 70 can be narrowed.

(9) In the first embodiment, a plurality of injection ports 52 of the supply passage 50 provided at the distal end portion 21 of the nozzle main body 20 are provided in the circumferential direction of the nozzle main body 20.
Thereby, the shape of the arc plasma 70 can be narrowed in the circumferential direction.

(10) The welding torch 10 of the first embodiment is used for the welding device 1.
Thus, the welding device 1 can deeply weld the work pieces 2 and 3 with each other. In addition, it is also possible to perform welding operation using this welding device 1 in place of the welding operation conventionally performed by the laser welding device. As a result, the welding equipment can be miniaturized and the cost of the power supply equipment used for the welding operation can be reduced.

(11) In the method of manufacturing a welded product according to the first embodiment, the tip portion 21 of the nozzle main body 20 and the work pieces 2 and 3 are provided from the supply passage 50 provided in the nozzle main body 20 provided in the welding torch 10 in the injection step S3. The shield gas is injected and supplied toward the central axis O side of the nozzle body 20 in the space between them. Further, in the suction step S4, the shield gas is suctioned from the tip end 21 side of the nozzle main body 20 by the suction passage 60.
Thereby, the shape of the arc plasma 70 formed between the workpieces 2 and 3 and the electrode 12 is narrowed. Therefore, since the arc plasma 70 is densified at the welding portion of the workpieces 2 and 3, the welding can be deeply embedded in the workpieces 2 and 3.

(12) In the method of manufacturing a welded product according to the first embodiment, the suction force of the shield gas in the direction orthogonal to the relative movement direction A is larger than the suction force of the shield gas in the relative movement direction A in the suction step S4.
Thereby, the shape of the arc plasma 70 can be made into a substantially elliptical shape having the major axis in the relative movement direction A.

Second Embodiment
A second embodiment of the present invention is shown in FIG. In addition, in several embodiment described below, the same code | symbol is attached | subjected to the structure substantially the same as 1st Embodiment mentioned above, and description is abbreviate | omitted.
In the second embodiment, the suction port 65 of the suction passage 60 is circular. That is, in FIG. 11, B = C. Further, in the second embodiment, the shape of the electrode 12 as viewed in the axial direction is a substantially elliptical shape having the major axis in the relative movement direction A. As a result, in the suction passage 60, the minimum width of the flow path cross section in the direction orthogonal to the relative movement direction A is larger than the minimum width of the flow path cross section in the relative movement direction A. Therefore, the suction force of the shield gas in the direction orthogonal to the relative movement direction A is larger than the suction force of the shield gas in the relative movement direction A. Therefore, the shape of the arc plasma 70 formed between the workpieces 2 and 3 and the electrode 12 has a substantially elliptical shape having a major axis in the relative movement direction A. Therefore, also in the second embodiment, the same operation and effect as those of the first embodiment described above can be achieved.

Third Embodiment
A third embodiment of the present invention is shown in FIG. In the third embodiment, six injection ports 52 of the supply passage 50 are provided at equal intervals in the circumferential direction of the nozzle body 20.
In the third embodiment, the suction port 65 of the suction passage 60 has a substantially elliptical shape having a major axis in the relative movement direction A. That is, in FIG. 12, B = C. The electrode 12 has a circular shape when viewed in the axial direction. Therefore, in the suction passage 60, the minimum width of the flow path cross section in the direction orthogonal to the relative movement direction A is larger than the minimum width of the flow path cross section in the relative movement direction A. Therefore, the suction force of the shield gas in the direction orthogonal to the relative movement direction A is larger than the suction force of the shield gas in the relative movement direction A. Therefore, also in the third embodiment, the same function and effect as those of the first and second embodiments described above can be obtained.

Fourth Embodiment
A fourth embodiment of the present invention is shown in FIGS. 13 and 14. In the fourth embodiment, the suction port 65 of the suction passage 60 is circular. In addition, the shape of the electrode 12 as viewed in the axial direction is circular. That is, in FIG. 13, B = C. Therefore, in the suction passage 60, the minimum width of the flow path cross section in the direction orthogonal to the relative movement direction A and the minimum width of the flow path cross section in the relative movement direction A are substantially the same. Therefore, the suction force of the shield gas in the direction orthogonal to the relative movement direction A and the suction force of the shield gas in the relative movement direction A are substantially the same over the entire circumference.

In FIG. 14, the schematic diagram of the arc plasma 70 at the time of welding using the welding torch 10 of 4th Embodiment is shown. Arrow J in FIG. 14 shows the flow of shield gas. The broken line 80 in FIG. 14 schematically shows the shape of the arc plasma according to the above-described comparative example.
In the fourth embodiment, as shown by an arrow 71 in FIG. 14, the shield gas is uniformly compressed in the circumferential direction and has a substantially cylindrical shape. Therefore, the shape of the arc plasma 70 is also a substantially cylindrical shape having a relatively small diameter, which is uniformly compressed and narrowed in the circumferential direction. Therefore, since the arc plasma 70 is densified at the welding portion of the workpieces 2 and 3, the welding can be deeply embedded in the workpieces 2 and 3.

Fifth Embodiment
A fifth embodiment of the present invention is shown in FIG. In the fifth embodiment, the injection port 521 of the supply passage 50 is provided in a ring shape continuously in the circumferential direction of the nozzle body 20. Also in the fifth embodiment, the same operation and effect as those of the above-described first to fourth embodiments can be obtained.

Sixth Embodiment
A sixth embodiment of the present invention is shown in FIG. In the sixth embodiment, the injection ports 52 of the supply passage 50 are located radially outward of the four small injection ports 52 provided in the circumferential direction of the nozzle body 20 and the four small supply ports, And a ring supply port 521 provided in a ring shape continuously in the circumferential direction of the nozzle body 20. Also in this sixth embodiment, the same operation and effect as those of the above-described first to fifth embodiments can be achieved.

Seventh Embodiment
A seventh embodiment of the present invention is shown in FIG. FIG. 17 is a cross-sectional view of the same portion as FIG. 7 in the first embodiment. In the seventh embodiment, the orifice 62 communicating the tapered flow passage 64 of the suction passage 60 with the gas passage 61 is provided continuously in the circumferential direction. Also according to this configuration, when gas flows into the gas passage 61, the orifice 62 becomes negative pressure, and shield gas is sucked from the tip 21 side of the nozzle body 20 through the suction passage 60.
Also in the seventh embodiment, the same function and effect as those of the above-described first to sixth embodiments can be obtained.

(Other embodiments)
(1) In the embodiment described above, four or six injection ports 52 of the supply passage 50 are provided at equal intervals, or the injection ports 521 are ring-shaped. On the other hand, in the other embodiment, the shape, position, size, etc. of the injection ports 52, 521 of the supply passage 50 are set in accordance with the pressure of the welding fumes generated when welding the workpieces 2, 3. It is also good.

(2) In the embodiment described above, a compressor is used as the gas discharge mechanism 9. On the other hand, in another embodiment, the gas discharge mechanism 9 may use a vacuum pump instead of the compressor. In this case, the vacuum pump can be configured to suction shield gas directly from the suction passage 60.

(3) In the embodiment described above, the welding torch 10 is configured to include the guide member 30 that supports the electrode 12 around the electrode 12. On the other hand, in other embodiments, the welding torch 10 may abolish the guide member 30. In this case, the suction passage 60 is formed between the inner wall of the nozzle body 20 and the electrode 12.

(4) In the embodiment described above, the welding torch 10 is configured to form parts such as the nozzle body 20, the guide member 30, and the electrode holding portion 40 by a metal 3D printer. On the other hand, in other embodiments, those parts may be formed by cutting.
As described above, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the scope of the invention in addition to combining the above-described plurality of embodiments.

DESCRIPTION OF SYMBOLS 10 ... Welding torch 12 ... Electrode 20 ... Nozzle main body 21 ... Tip part 50 ... Supply passage 60 ... Suction passage

Claims (14)

In the welding torch that performs arc welding on the workpiece (2, 3),
A cylindrical nozzle body (20),
An electrode (12) that passes through the inside of the nozzle body and is exposed at the tip (21) of the nozzle body;
A supply passage (50) provided in the nozzle body and injecting and supplying shield gas to the tip end side of the nozzle body;
And a suction passage (60) provided radially inward of the supply passage in the nozzle body and around the electrode, and sucking shield gas from the tip end side of the nozzle body,
In the suction passage, the minimum width (F) of the channel cross section in the direction orthogonal to the direction (A) in which the workpiece and the electrode move relative to each other is the channel cross section in the direction in which the workpiece and the electrode move relative to each other the minimum width (G) and the same or larger than,
The suction port (65) of the suction passage provided at the tip end of the nozzle body has a distance (B) between the inner walls in a direction orthogonal to the direction in which the work and the electrode move relative to each other. The welding torch which is a shape longer than the distance (C) between the inner walls of the direction which a said electrode and a relative movement move . The cross-sectional area (D) of the suction port of the suction passage provided at the tip end of the nozzle body is the flow channel cross-sectional area (E) of the suction passage located on the back side of the nozzle body than the suction port. The welding torch according to claim 1, which is smaller than the above. In the welding torch that performs arc welding on the workpiece (2, 3),
A cylindrical nozzle body (20),
An electrode (12) that passes through the inside of the nozzle body and is exposed at the tip (21) of the nozzle body;
A supply passage (50) provided in the nozzle body and injecting and supplying shield gas to the tip end side of the nozzle body;
And a suction passage (60) provided radially inward of the supply passage in the nozzle body and around the electrode, and sucking shield gas from the tip end side of the nozzle body,
In the suction passage, the minimum width (F) of the channel cross section in the direction orthogonal to the direction (A) in which the workpiece and the electrode move relative to each other is the channel cross section in the direction in which the workpiece and the electrode move relative to each other the minimum width (G) and the same or larger than,
The cross-sectional area (D) of the suction port (65) of the suction passage provided at the tip end portion of the nozzle body is the flow channel cross-sectional area of the suction passage located on the back side of the nozzle body than the suction port. Welding torch which is smaller than (E) . A gas passage (61) through which the gas flows;
The welding torch according to any one of claims 1 to 3, further comprising an orifice (62) provided at a place where the suction passage and the gas passage communicate with each other.   The welding torch according to claim 4, wherein the suction passage has a tapered flow passage (64) in which the flow passage cross-sectional area gradually decreases toward the orifice. It further comprises a guide member (30) provided around the electrode,
The welding torch according to claim 4 or 5, wherein the suction passage and the orifice are formed between an inner wall of the nozzle body and an outer wall of the guide member.   The said supply channel is inclined toward the central axis (O) side of the said nozzle main body toward the said tip part side from the base end (23) side of the said nozzle main body in any one of Claim 1 to 6 Welding torch.   The welding torch according to any one of claims 1 to 7, wherein the supply passage goes from the proximal end side to the tip end side of the nozzle body, and the flow passage cross-sectional area gradually decreases.   The welding torch according to any one of claims 1 to 8, wherein the supply passage is curved in a radially outwardly convex arc shape extending from the base end side to the tip end side of the nozzle body.   The welding according to any one of claims 1 to 9, wherein a plurality of injection ports (52) of the supply passage provided at the tip end of the nozzle body are provided in the circumferential direction of the nozzle body. torch.   The injection port (521) of the supply passage provided at the tip end portion of the nozzle body is provided in a ring shape continuously in the circumferential direction of the nozzle body. Welding torch as described in. The injection port of the supply passage provided at the tip end of the nozzle body is
A plurality of small injection ports (52) provided in the circumferential direction of the nozzle body;
10. A ring injection port (521) provided in a ring shape continuously in the circumferential direction of the nozzle body at a position radially outward of the plurality of small injection ports. The welding torch according to any one of the preceding claims. In welding equipment that performs arc welding on workpieces,
An installation unit (6) for installing the work;
The welding torch according to any one of claims 1 to 12, wherein the welding torch is installed so that an electrode faces the welding portion of the work.
A power supply unit (7) for supplying power to the electrode provided in the welding torch;
A gas supply source (8) for supplying shielding gas to a supply passage provided in the welding torch;
And a gas discharge mechanism (9) for discharging shield gas from the suction passage by applying a negative pressure to a suction passage provided in the welding torch. A work setting step (S1) of setting a work in an installation portion of a welding apparatus;
A torch installation step (S2) of installing a welding torch in the welding device;
An injection step (S3) of injecting shield gas from the supply passage provided in the nozzle body provided in the welding torch toward the central axis side of the nozzle body in the space between the tip of the nozzle body and the work )When,
A suction step (S4) of suctioning shield gas from the tip end side of the nozzle body by a suction passage provided radially inward of the supply passage in the nozzle body and around the electrode;
While the arc discharge into the workpiece from the electrode, said a work and the electrode and relative movement to the welding step (S5), only contains,
In the suction step, the suction force of the shield gas in the direction orthogonal to the direction in which the work and the electrode move relative to each other is greater than the suction force in the direction in which the work and the electrode move relative to each other Method of manufacturing welded products.

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