JP3088618B2 - Torch for gas shielded arc welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torch for a welding machine, and more particularly to a torch for use in a gas shielded arc welding machine for performing arc welding in a shielding gas atmosphere using a continuously supplied filler material.

[0002]

2. Description of the Related Art A torch used in a gas shielded arc welding machine for performing arc welding in a shielding gas atmosphere such as an inert gas or a carbon dioxide gas is disclosed in Japanese Utility Model Laid-Open No. 59-20986. The torch includes a tip member for supporting a welding wire serving as a filler material, a cylindrical nozzle arranged on the outer periphery of the tip member, and a shield gas supply unit for supplying a shield gas to a space between the tip member and the nozzle. And a gas supply unit for supplying a sputter removal gas to the space. During welding, the shield gas supplied from the shield gas supply unit comes out from between the nozzle and the filler material support unit and wraps the arc and the molten metal. As a result, oxidation and nitridation of the molten metal do not occur. Further, in this gas shielded arc welding torch, the gas supply unit is two air supply tubes fixed outside the nozzle. 2
The air supply pipes face in the direction of the dividing line with respect to the annular air passage, and the air supplied from the two air supply pipes swirls around the support portion to blow off the spatter attached to each member. As described above, since the amount of spatter attached is reduced,
It is difficult to reduce the amount of shielding gas jet.

[0003]

With the vortex air according to the above-mentioned conventional structure, spatters attached to each member of the torch cannot be sufficiently blown off. As a result, the amount of sputter adherence increases, and the amount of jet of the shielding gas decreases. It is necessary to stop the welding machine in a short time and clean each member manually.

[0004] It is an object of the present invention to sufficiently blow off spatter attached to each member of a torch, thereby extending the continuous operation time of a welding machine.

[0005]

According to a first aspect of the present invention, there is provided a torch for a gas shielded arc welding machine which performs arc welding in a shield gas atmosphere using a continuously supplied wire-like filler material. It has an additive support, a cylindrical nozzle, a shield gas supply, and an air source. The filler support extends in one direction to support the filler. A plurality of communication holes penetrating inside and outside are formed in the filler material support portion. The cylindrical nozzle portion is arranged at intervals around the filler material support portion. An air introduction port penetrating the inside and outside is formed in the cylindrical nozzle portion. The shield gas supply unit supplies a shield gas between the filler support and the nozzle unit. The air source supplies 50 spatter removing gas from between the plurality of communication holes and outside the air inlet between the filler support and the nozzle.
Supply at a flow rate of 00 liter / min or more . In gas shielded arc welding machine torch according to claim 2, claim 1
In the above, the shield gas supply section supplies the shield gas between the filler support section and the nozzle section from the plurality of communication holes.

[0006]

[0007]

In the torch for a gas shielded arc welding machine according to the present invention, at the time of welding, the filler material supported by the filler material support portion is continuously supplied, and at the same time, the welding is performed by the shield gas supply portion. A shielding gas is supplied between the material support and the nozzle. As a result, the arc and the molten metal in the welded portion are wrapped in the shielding gas and welded. At this time, the molten metal scatters as spatter and adheres to each member of the torch. After the welding is completed, a gas for removing spatter is supplied from the air source to the space between the filler material support portion and the nozzle portion from the inside of the plurality of communication holes and from outside the air inlet to blow off the spatter. Here, gas is supplied from inside and outside of the nozzle portion, so that the entire gas flow rate can be increased. For example, the gas can be supplied at a flow rate of 5000 liter / minute or more in total. As a result, even if the welding and spatter removing operations are continuously performed, the continuous operation can be performed for 3 hours or more.

[0008]

[0009]

EXAMPLES In the first embodiment FIG. 1, inert gas shielded arc welding machine 1 in which one embodiment of the present invention is employed mainly from the welding power source 2 and the gas supply device 3 and the wire feeder 4 and the torch 5 which It is configured.

The welding power source 2 is for generating a DC welding current from a three-phase 200 volt AC power source. The welding power source 2 includes a control unit 14 (described later). Further, an earth electrode 16 is connected to the welding power source 2. The gas supply device 3 includes an argon gas cylinder 6 filled with a high-pressure argon gas, a carbon dioxide gas cylinder 7 filled with a high-pressure carbon dioxide gas, and a mixing chamber 8 for mixing the argon gas and the carbon dioxide gas to form a shielding gas. And An argon gas flow controller 9 is arranged between the argon gas cylinder 6 and the mixing chamber 8. A carbon dioxide gas flow controller 10 is arranged between the carbon dioxide gas cylinder 7 and the mixing chamber 8. A mixing prevention circuit 35 is connected to the mixing chamber 8 via a pipe and a rubber hose. The mixing prevention circuit 35 is also connected to an unillustrated air source composed of a high-pressure compressor that generates compressed air of 1 MPa, for example. The mixing prevention circuit 35 is provided to control the air supplied from the air source and the shielding gas supplied from the gas supply device 3 and to prevent the mixing of the air and the shielding gas. The mixing prevention circuit 35 is a rubber hose 17
Is connected to the torch 5.

The wire supply device 4 includes a wire reel mounting portion 12 for mounting the wire reel 11 around which the welding wire 26 is wound, and a feed roller for feeding the welding wire 26 wound around the wire reel 11 into the torch 5. 13 is provided. The feed roller 13 supplies the welding wire 26 to the torch 5 at a constant speed with respect to the welding speed.

The torch 5 includes a coil liner 20 through which a welding wire 26 is inserted, and a torch nozzle 21 attached to a tip of the coil liner 20. At the base end of the coil liner 20, the above-described mixing prevention circuit 3 is provided.
Rubber hoses 17 from 5 are connected. As shown in FIG. 2, the torch nozzle 21 includes a cylindrical oxygen-free copper nozzle body 22, a wire support portion 23 screwed to a tip of the coil liner 20 and arranged concentrically inside the nozzle body 22. The air blow adapter 24 is mainly composed of an aluminum air blow adapter 24 disposed at two locations on the bottom outer periphery of the nozzle body 22 so as to face each other.

A flanged cylindrical carbon coating 25 is screwed into the opening on the tip end of the nozzle body 22. The covering portion 25 is arranged so as to cover the inner peripheral surface from the tip of the nozzle main body 22 to the back side of the predetermined portion. Since the covering portion 25 is screwed, the nozzle body 22
Can be attached to and detached from. The wire support portion 23 is arranged on the inner peripheral side of the nozzle body 22 and forms an annular passage 34 with the nozzle body 22. Wire support 23
Is composed of a tip body 23a screwed to the coil liner 20 and a contact tip 23b screwed to the tip of the tip body 23a. The tip of the contact tip 23b extends further than the tip of the nozzle body 22. At the center of the wire support 23, a wire hole 27 is formed having a diameter substantially the same as the wire diameter and extending in the longitudinal direction of the torch for inserting a welding wire 26 therethrough. The wire hole 27 supports the welding wire 26 movably in the axial direction. The wire support 23 is used for the welding power source 2
And has a function as a welding electrode. The tip body 23a of the wire support 23
, A hole 28 having a larger diameter than the wire hole 27 is formed inside. This hole 28 is provided with a hole 29 in the coil liner 20.
Is in communication with At the tip of the hole 28, the wire support 23
And eight communication holes 30 communicating with a space 34 formed by the outer peripheral surface of the nozzle body 22 and the inner peripheral surface of the nozzle body 22. The hole diameter of each communication hole 30 is 2 mm.

An insulating bush 45 made of an insulating resin is screwed to the outer periphery of the base side of the wire supporting portion 23. The base of the nozzle body 22 is screwed to the outer periphery of the insulating bush 45. Two air inlets 31 are formed around the shoulder portion of the insulating bush 45 in the nozzle body 22 so as to penetrate in the radial direction and face the insulating bush 45.

Each air blow adapter 24 has a bolt 46
Is fixed to the outer periphery of the nozzle body 22. Since the air blow adapter 24 is provided at two locations, the flow rate supplied from the air blow adapter 24 increases. An air supply port 32 is provided at the end of the air blow adapter 24.
Is formed therein, and an air introduction hole 33 that connects the air introduction port 31 and the air supply port 32 is formed therein.
The hole diameter of the air introduction hole 33 is 5 mm. Air supply port 32
Is a mixing prevention circuit 35 via a rubber hose (not shown).
It is connected to the. Here, the air blow adapter 24
Is detachable from the nozzle body 22, the air blow adapter 2 is used when the consumable nozzle body 22 is replaced.
4 can be removed. Therefore, the externally supplied air supply unit, which was conventionally wasted, is not wasted.

The mixing prevention circuit 35 is a circuit for preventing air from entering the shield gas during welding. As shown in FIG. 3, the mixing prevention circuit 35 includes a shield gas on-off valve 3 for opening and closing the shield gas supplied from the gas supply device 3.
9 and 40, air on / off valves 41 and 42 for opening and closing high-pressure air from an air source, respectively, and mixing prevention valves 43 and 44 connected to the air on / off valves 41 and 42, respectively.
The shield gas on-off valves 39 and 40 are, for example, a direct-acting 2
The air on-off valves 41 and 42 are, for example, pilot-type two-port piston driven valves. The mixing prevention valves 43 and 44 are, for example, three-port poppet type valves. The shield gas on-off valve 39 and the mixing prevention valve 44 are connected to an air connection port (not shown) of the coil liner 20 via the rubber hose 17. The shield gas on-off valve 40 and the mixing prevention valve 43 are connected to the air supply port 32 of the air blow adapter 24 via a rubber hose.

The control unit 14 includes a microcomputer including a CPU, a ROM, a RAM, and the like. As shown in FIG. 4, a remote controller 15, a feed roller 13, shield gas on-off valves 39 and 40, air on-off valves 41 and 42, mixing prevention valves 43 and 44, and other input / output devices are connected to the control unit 14. Have been. With the above structure, the operator can easily change various operation settings via the remote controller 15. For example, the welding time per one time, the timing and time for injecting air for blowing off spatter after welding is completed,
The injection timing and time of the preflow gas can be set to optimal values according to the conditions.

Next, the operation of the above embodiment will be described. In this embodiment, the spatter is removed each time one welding is completed. Specifically, one cycle consists of welding (shield gas injection) → spatter removal (high-pressure air injection)
→ Residual air purge (shield gas injection). At the time of welding, the air on-off valves 41 and 42 are closed, and the mixing prevention valves 43 and 44 are exhausted. Then, the shield gas on / off valves 39 and 40 are opened to supply the shield gas to the air supply port 32 of the air blow adapter 24 and the hole 29 in the coil liner 20. The shielding gas is
The air enters the nozzle main body 22 through the communication hole 30 between the air inlet 31 and the tip body 23a, and further moves to the distal end side through the annular space. As a result, the shield gas supplied from the gas supply device 3 is jetted from the tip of the torch nozzle 21. This shuts off the molten material and air during the welding operation.

At the time of welding, both the mixing prevention valves 43 and 44 are in an exhaust state. Even if air leaks from the air on-off valves 41 and 42, the leaked air is exhausted by the mixing prevention valves 43 and 44. As a result, no air is supplied to the torch 5 during welding. During this welding, if spatter occurs, a part of the spatter tends to adhere to the tip of the nozzle body 22,
Since the coating portion 25 made of carbon is arranged at the inner peripheral end of the nozzle main body 22, the generated spatter hardly adheres.

When the welding is completed, for example, after waiting a predetermined time for the workpiece to move away from the torch 5, the air opening / closing valves 41, 42 are opened and the mixing prevention valves 43, 42 are opened.
44 is opened. In addition, shield gas on-off valve 3
9, 40 are turned off. As a result, high-pressure air from the air source is supplied to the air supply port 32 of the air blow adapter 24 and the hole 29 in the coil liner 20. The air supplied to the air supply port 32 is supplied from the air introduction port 31 on the side surface of the nozzle body 22 to the annular passage 34 on the inner peripheral side of the nozzle body 22. At this time, the flow rate of the air supplied to the air supply port 32 is 4500 liters / minute. On the other hand, the flow rate of the air supplied to the holes 29 is 3000 liter / minute. Air is supplied at a flow rate of 7500 liters / minute in total. This air blows off the spatter attached to each member. Since the flow rate is increased, the effect of removing spatter is improved. In addition, since the air cools each part of the torch 5, spatter generated at the time of the next welding is less likely to adhere to each part. Here, since the flow rate is large,
The cooling of each part is improved. Generally, it is preferable that the temperature of each component is about 100 ° C. or less. At 60 ° C., the amount of spatter adhered is greatly reduced. In this embodiment, during continuous operation, the number of times that the temperature at the tip of the nozzle body 22 reaches 60 ° C. is larger than in the conventional case. Furthermore, the temperature does not reach 100 ° C. even after 100 continuous operations.

Further, the air inlet 31 is connected to the insulating bush 4.
5 is directed to the shoulder portion, so that the air is
It is injected directly into the shoulder. Since the insulating bush 45 is a portion to which spatter easily adheres, blowing air directly to this portion to blow off spatter has excellent effects in terms of improving the durability of the insulating bush 45 and preventing spatter deposition.

When the torch 5 is used, the adhesion of spatter can be prevented with a simple structure in which the coating portion 25 made of carbon is disposed at the tip and high-pressure air is supplied.
For this reason, the weight of the torch nozzle 5 can be reduced, and the capacity of the automation device when automated can be reduced. Further, since the carbon-made coating portion 25 is detachable by screwing, when the sputter adhesion performance is deteriorated, by replacing it, a long-term spatter removal effect can be obtained.

When a predetermined time (about 2 minutes) elapses and the blowing of the spatter is completed, the shield gas on-off valves 39 and 4
0 is opened, the air on-off valves 41, 42 are shut off, and the mixing prevention valves 43, 44 are shut off. As a result, the shield gas is
Air supply port 32 and hole 29 in coil liner 20
Supplied to This shielding gas is supplied to the air introduction holes 33,
Air remaining in the annular space 34 and the hole 29 is expelled toward the tip of the torch 5 to create a shield gas atmosphere in the annular space 34. Thereby, the residual air is not injected from the tip of the torch 5 at the next welding. Since the pre-flow shielding gas is supplied from the air blow adapter 24, the flow rate is large. Therefore, the residual air can be reliably expelled in a short time (about 3 minutes).

In this embodiment, since the spatter removing effect is enhanced by various structures, it is not necessary to stop the welding machine every predetermined time and remove the spatter by hand as in the prior art. As a result, the continuous operation time of the welding machine can be set to 8 hours or more. (Experimental example)

[0025]

[Table 1]

As shown in Table 1, an experiment was conducted on the relationship between the flow rate of the spatter removing air and the spatter removing effect of the nozzle. The torch used in this experiment has almost the same structure as the above embodiment. First Example Sputter removal air was supplied only from the holes of the chip body without providing an air blow adapter. Holes are formed in four places and the diameter is 2 mm. Air flow is 1498
Feed at liter / min for 2 minutes. After 2 hours, spatter was deposited and the injection amount of inert gas became insufficient. The second example holes formed in eight locations. The flow rate was 2996 l / min. It took 3 hours for the inert gas to come out sufficiently. Third Example As in the second example, holes were provided at eight locations, and an air supply port from an air blow adapter was provided at one location outside the nozzle. The diameter of the air supply port of the air blow adapter is 5 mm. The flow from the air blow adapter was 2340 liters / minute, for a total flow of 5336 liters / minute. It took 5 hours for the inert gas to come out sufficiently. Fourth Example (Structure Corresponding to the Example) Similar to the above-described example, holes were provided at eight places, and air supply ports from an air blow adapter were provided at two places outside the nozzle. The hole diameter of the air blow adapter is 5 mm. The flow from the air blow adapter was 4680 liters / minute, for a total flow of 7676 liters / minute. It took 8 hours for the inert gas to come out sufficiently. Fifth Example The hole diameter of the air blow adapter in the fourth example was 6 mm. Although the flow rate was lower than in the fourth example, the flow rate was increased, and the total flow rate was 9736 liter / min. It took 8 hours for the inert gas to come out sufficiently. Sixth Example The hole diameter of the air blow adapter in the fifth example was set to 10 mm. Although the flow rate was lower than in the fifth example, the flow rate increased, and the total flow rate became 21722 liters / minute. It took 8 hours for the inert gas to come out sufficiently. [Modifications] (a) In the above embodiment, spatters are removed each time welding is performed, but spatters may be removed after welding is performed a plurality of times. Also in that case, the present invention can sufficiently remove spatter. (B) Although high-pressure air is used as a gas for removing spatter, other gases such as nitrogen gas may be used. (C) In the above embodiment, the tip of the covering portion 25 may be rounded. This can further reduce spatter adhesion.

[0027]

In the torch for a gas shielded arc welding machine according to the present invention, after the welding is completed , the welding is performed from inside and outside the nozzle.
Gas is supplied between the filler support section and the nozzle section,
Blows away. Here, gas is supplied from two types of holes
The total gas flow can be increased

[0028]

[Brief description of the drawings]

FIG. 1 is a side view of an inert gas shielded arc welding machine employing one embodiment of the present invention.

FIG. 2 is a partial sectional view of a torch.

FIG. 3 is a circuit diagram of a mixing prevention circuit.

FIG. 4 is a block diagram showing a control configuration of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inert gas shield arc welding machine 3 Gas supply device 5 Torch 21 Torch nozzle 22 Nozzle main body 23 Wire support part 24 Air blow adapter

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-46882 (JP, A) JP-A-7-40054 (JP, A) JP-A-49-106943 (JP, A) 5770 (JP, U) Japanese Utility Model Showa 57-176182 (JP, U) Japanese Utility Model Application Hei 2-28380 (JP, U) Japanese Patent Publication No. 51-27620 (JP, B1) Japanese Patent Publication No. 46-39449 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 9/29 B23K 9/16

Claims (2)

(57) [Claims] A gas shield for performing arc welding in a shield gas atmosphere using a continuously supplied wire-like filler material.
A torch for an arc welding machine, which is a member extending in one direction to support the filler material, and a filler material support part having a plurality of communication holes (30) penetrating inside and outside; A cylindrical nozzle portion, which is arranged at intervals around the filler material support portion and has an air inlet (31) penetrating inside and outside, and between the filler material support portion and the nozzle portion, A shielding gas supply unit for supplying a shielding gas; and a gas for removing spatter from the plurality of communication holes and between the filler support and the nozzle unit from outside the air introduction port. An air source for supplying at a flow rate of 1 liter / min or more, and a torch for a gas shielded arc welding machine, comprising: 2. The gas shielded arc welding machine according to claim 2, wherein the shield gas supply section supplies the shield gas from between the plurality of communication holes and between the filler support section and the nozzle section. torch.