Tip structure of weld torch, weld torch, and weld method

Abstract

To provide a tip structure of a weld torch in which a weld wire is guided into a weld portion while preventing a nozzle from contacting with a base material.SOLUTION: A tip structure of a weld torch guiding a weld wire into a weld portion to perform weldment comprises: a tubular nozzle with a hollow part which is attached to a tip part of the weld torch; a first holding part which is movably held in a direction orthogonal to a central axis of the nozzle in the nozzle; and a second holding part which includes a hollow guide part capable of guiding a weld wire and is held at a tip side of the nozzle in the first holding part. The second holding part is held to be inclinable regarding the central axis of the nozzle with respect to the first holding part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tip structure of a welding torch, a welding torch, and a welding method. [Background technology]

[0002] An example of an invention involving a tiltable welding torch is the welding device disclosed in Patent Document 1. The welding device disclosed in Patent Document 1 is a device for butt welding pipes, and the welding torch can be tilted in the circumferential direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-200866 Summary of the Invention [Problem to be solved by the invention]

[0004] One example of a groove used in welding structures is a square groove. When welding a square groove, unless the nozzle of the welding torch is tilted toward the slope of the square groove, the nozzle comes into contact with the base material, making it impossible to guide the tip of the welding wire to the center of the groove. The welding device disclosed in Patent Document 1 can tilt the welding torch, but can only tilt it toward the weld line. Therefore, when welding a square groove, the nozzle cannot be tilted toward the slope of the square groove, making it impossible to solve the problem of not being able to guide the tip of the welding wire to the center of the groove.

[0005] The present invention has been made in view of the above, and has an object to guide a welding wire to a welding point without bringing the nozzle into contact with the base metal. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the tip structure of a welding torch of the present invention is a tip structure of a welding torch for guiding a welding wire to a welding site and welding, and includes a tubular, hollow nozzle attached to the tip portion of the welding torch, a first holding part held within the nozzle so as to be movable in a direction perpendicular to the central axis of the nozzle, and a hollow guide part capable of guiding the welding wire, and a second holding part held on the nozzle tip side of the first holding part, and the second holding part is held so as to be tiltable with respect to the first holding part with respect to the central axis of the nozzle.

[0007] In the welding torch tip structure according to the present invention, the first holding portion may have a gas flow path that guides a shielding gas to the hollow portion.

[0008] A welding torch according to the present invention includes the tip structure of the welding torch described above.

[0009] Furthermore, the welding method according to the present invention is a welding method using the above welding torch, and when the welding portion is a V-shaped groove that is forward welded, the first holding portion is moved in a direction perpendicular to the front side of the central axis of the nozzle to hold the portion and perform welding. [Effects of the Invention]

[0010] According to the present invention, it is possible to guide the welding wire to the welding point without bringing the nozzle into contact with the base material. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of a welding system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram of a cross section of the tip of a welding torch. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. [Figure 4A] FIG. 4A is a diagram showing a state in which the contact tip is eccentric. [Figure 4B] FIG. 4B is a diagram showing a state in which the contact tip is tilted. [Figure 5A] FIG. 5A is a schematic diagram of the tip when welding a T-joint. [Figure 5B] FIG. 5B is a schematic diagram of the tip when welding a T-joint. [Figure 6A] FIG. 6A is a schematic diagram of the tip when welding a V-groove. [Figure 6B] FIG. 6B is a schematic diagram of the tip when welding a V-groove. [Figure 7A] FIG. 7A is a schematic diagram of the tip when forward welding a V-groove. [Figure 7B] FIG. 7B is a schematic diagram of the tip when forward welding a V-groove. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below. In addition, in the description of the drawings, the same or corresponding elements are appropriately designated by the same reference numerals. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationships between the elements may differ from the actual ones. There may also be parts in which the dimensional relationships and ratios between the elements differ from one another.

[0013] 1 is a diagram showing the configuration of a welding system 1000 according to an embodiment of the present invention. The welding system 1000 is a system for performing semi-automatic welding, and includes a welding torch 1, a wire feeder 2, a power source 3, and a gas cylinder 4.

[0014] The power supply 3 is connected by a cable to the feeder 2 and the base material 5 to be welded. The power supply 3 has a rectifier circuit, an inverter circuit, and a smoothing circuit, and converts AC from a commercial power source into DC suitable for welding the base material 5 and supplies it to the feeder 2.

[0015] The gas cylinder 4 is connected to the feeder 2 by a gas hose. The gas cylinder 4 supplies the feeder 2 with a shielding gas for isolating the periphery of the arc and molten pool from the atmosphere in semi-automatic welding.

[0016] The welding torch 1 is connected to the wire feeder 2, which contains the welding wire used for semi-automatic welding. The wire feeder 2 supplies the welding torch 1 with the welding wire, shielding gas supplied from a gas cylinder 4, and DC current supplied from a power source 3.

[0017] The welding torch 1 includes a tip 10, a torch body 11, a handle 12, and a torch cable 13. The torch cable 13 is connected to a welding wire feeder 2. The torch cable 13 includes a coiled conduit tube that guides the welding wire supplied from the welding wire feeder 2, a conductor that transmits the direct current supplied from the welding wire feeder 2 to the torch body 11, a gas passage that transmits the shielding gas supplied from the welding wire feeder 2 to the torch body 11, and the like.

[0018] Handle 12 is a part that is held by the hand of an operator performing welding. Handle 12 holds the end of torch cable 13. Torch switch 12a is an operating part for supplying welding wire, shielding gas, DC current, etc. to base material 5. When an operator operates torch switch 12a, the welding wire, shielding gas, and DC current fed from feeder 2 via torch cable 13 are sent to torch body 11.

[0019] Torch body 11 is bendable, and one end is held by handle 12. Torch body 11 includes a tube that guides the welding wire fed from torch cable 13, a conductor that sends the direct current supplied from torch cable 13 to tip 10, and a gas passage through which shielding gas fed from torch cable 13 passes. Tip 10 is attached to the other end of torch body 11.

[0020] 2 is a schematic diagram of a cross section of the end and tip portion 10 of torch body 11. The end of torch body 11 on the tip portion 10 side is provided with connection portion 112 formed of a conductor inside insulating sheath 111. Connection portion 112 is supplied with direct current from the conductor provided in torch body 11. Connection portion 112 is threaded on the outer peripheral surface at the end, and has a hole 11a that penetrates the center in the longitudinal direction and through which tube 113 is inserted and through which shielding gas passes. Tube 113 is a hollow tube that guides the welding wire, and the welding wire passes through the hollow portion.

[0021] The tip portion 10 includes a contact tip 20 , a tip body 30 , a movable portion 40 , an insulator 50 , and a nozzle 60 .

[0022] The cylindrical insulator 50 includes a bushing 51 and a base 52. The insulator 50 has a threaded hole 50a that penetrates from the inner peripheral surface to the outer peripheral surface. The bushing 51 is formed into a cylindrical shape from an insulating material such as a heat-resistant hard resin. The bushing 51 is threaded on the upper and lower ends of the inner peripheral surface, and the end of the connection portion 112 is fitted into the upper end. The base 52 is formed into a cylindrical shape from a metal such as brass, and is fixed to the outer surface of the bushing 51.

[0023] The nozzle 60 is a tubular metal component. The contact tip 20 and tip body 30 are located in a hollow portion 61 of the nozzle 60. The outer peripheral surface of the upper end of the nozzle 60 is threaded, and the upper end of the nozzle 60 is fitted onto the inner peripheral surface of the lower end of the bushing 51.

[0024] The movable part 40 is made of a conductive metal and is inserted inside the bushing 51. The movable part 40, which is an example of a first holding part, is composed of a flange part 41 that is circular when viewed from above and contacts the connecting part 112, and a holding part 42 that is below the flange part 41 and has a smaller diameter than the flange part 41 and into which the tip body 30 is inserted. The movable part 40 also has a hole 40a that penetrates the center from top to bottom, a hole 40b that penetrates the holding part 42 from the hole 40a toward the outer circumferential surface, and a threaded hole 40c that penetrates the holding part 42 from the hole 40a toward the outer circumferential surface. The holes 40a and 40b are an example of a gas flow path that guides shielding gas to the hollow part 61 of the nozzle 60. The shielding gas supplied from the hole 11a passes through the holes 40a and 40b and is supplied to the hollow part 61.

[0025] Fig. 3 is a cross-sectional view taken along line AA in Fig. 2. Screw holes 50a are formed in four locations at 90-degree intervals in the insulator 50. The screws 43 are insulating screws. The flange portion 41 is fixed inside the insulator 50 by the four screws 43 fitted into the screw holes 50a.

[0026] Tip body 30, which is an example of a second holding portion, is composed of holding portion 31 into which contact tip 20 fits and a spherical held portion 32, with holes 30a penetrating held portion 32 and holding portion 31 formed in the centers of both held portion 32 and holding portion 31. Hole 30a is an example of a guide portion that guides the welding wire. Held portion 32 is fixed inside holding portion 42 by screws 44. Holding portion 31 is threaded on its inner circumferential surface, and has a threaded hole 30b with a larger diameter than hole 30a.

[0027] The contact tip 20 has a thread cut on the outer peripheral surface of its upper end, and this end is fitted into and fixed in a threaded hole 30b in the tip body 30. The contact tip 20 also has a hole 20a formed therein that passes through the center from one longitudinal end to the other, through which a welding wire passes. The end of the tube 113 comes into contact with the upper end of the contact tip 20, and the welding wire fed from the tube 113 passes through hole 20a and protrudes from the lower end of the contact tip 20.

[0028] 4A is a diagram showing a state in which the central axis of contact tip 20 is offset from the central axis of nozzle 60. By fixing flange portion 41 with screws 43 in a state in which movable portion 40 is shifted in a direction perpendicular to the central axis of nozzle 60 so that the central axis of contact tip 20 is offset from the central axis of the nozzle, the position of the welding wire protruding from contact tip 20 can be made offset from the center of nozzle 60.

[0029] 4B is a diagram showing a state in which the contact tip 20 is tilted relative to the nozzle 60. The tip body 30 and the contact tip 20 can be tilted in any direction as a unit with respect to the central axis of the nozzle 60, and by fixing the held portion 32 with a screw 44 while the tip body 30 and the contact tip 20 are tilted, the welding wire can be fed out at an angle.

[0030] Next, an example of how to use the welding torch 1 will be described. Figures 5A and 5B are schematic diagrams of the tip portion 10 when welding a T-joint with the welding torch 1. When the contact tip 20 is not eccentric and not tilted, as shown in Figure 5A, the nozzle 60 holding the contact tip 20 comes into contact with the base metal 5 when it is brought close to the welding location. On the other hand, when the contact tip 20 is eccentric and tilted relative to the nozzle 60 as shown in Figure 5B, the welding wire W can be guided to the welding location without the nozzle 60 coming into contact with the base metal 5.

[0031] 6A and 6B are schematic diagrams of the tip 10 when welding a square groove with the welding torch 1. When the contact tip 20 is not eccentric and not tilted, the end of the nozzle 60 hits the inclined surface of the base material 5 as shown in Fig. 6A, and the welding wire W cannot be guided to the center of the groove. On the other hand, when the contact tip 20 is eccentric and tilted relative to the nozzle 60 as shown in Fig. 6B, the welding wire W can be guided to the center of the groove.

[0032] 7A and 7B are schematic diagrams of the tip 10 when forward welding a V-groove. When forward welding is performed, welding is performed at a forward angle, improving the front shielding provided by the shielding gas G. However, when the contact tip 20 is not eccentric as shown in FIG. 7A, the rear shielding is reduced, and when the base metal 5 is aluminum, the reduced shielding can lead to smut. On the other hand, when the contact tip 20 is eccentric to the welding direction as shown in FIG. 7B, the rear shielding is improved and smut can be suppressed.

[0033] [Variations] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be implemented in various other forms. For example, the above-described embodiments may be modified as follows to implement the present invention. The above-described embodiments and the following modifications may be combined with each other. The present invention also includes configurations in which the components of the above-described embodiments and modifications are appropriately combined. Furthermore, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the above-described embodiments and modifications, and various modifications are possible.

[0034] In the present invention, when the tip body 30 and the contact tip 20 are decentered and tilted, the decentering and tilting may be performed by a drive mechanism equipped with a motor.

[0035] The configuration of the embodiment in which the tip body 30 and the contact tip 20 are eccentric and tilted may be employed in a robot that performs automatic welding. [Explanation of symbols]

[0036] 1 welding torch 2 Feeding device 3 Power supply 4 gas cylinders 5 Base material 10 Tip 20 Contact Tips 30 Tip Body 40 Moving parts 50 insulator 60 nozzles 1000 Welding System

Claims

1. A tip structure of a welding torch for guiding a welding wire to a welding portion and welding, a nozzle having a tubular shape and a hollow portion, attached to a tip portion of the welding torch; a first holding portion that is held within the nozzle so as to be movable in a direction perpendicular to a central axis of the nozzle; a hollow guide portion capable of guiding a welding wire; and a second holding portion held by the first holding portion on the nozzle tip side, A tip structure of a welding torch in which the second holding portion is held by the first holding portion so as to be tiltable with respect to the central axis of the nozzle.

2. The first holding portion has a gas flow path that guides a shielding gas to the hollow portion. The tip structure of a welding torch according to claim 1.

3. A welding torch comprising the tip structure of a welding torch according to claim 1 or 2.

4. A welding method using the welding torch according to claim 3, A welding method in which, when a V-shaped groove is to be forward welded, the first holding part is moved and held in a direction perpendicular to the center axis of the nozzle, and welding is performed.

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