JP2996597B2 - 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 Generally, 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 fixed to a tip end of a coil liner extended from a wire feeder. It has a tip member and a cylindrical nozzle arranged on the outer periphery of the tip member. The tip member has a wire hole through which the welding wire passes. A cylindrical insulating member is disposed between the base of the tip member and the base of the cylindrical nozzle. This insulating member is for insulating the cylindrical nozzle from the tip member functioning as a welding electrode. The insulating member is screwed to the tip member and screwed to the cylindrical nozzle.

Further, the torch includes a shield gas supply unit for supplying a shield gas to a space between the tip member and the cylindrical nozzle, and a gas supply unit for supplying a gas for removing spatter to the space. . The gas supply unit includes an air blow tube connected to the outer periphery of the nozzle in order to increase the flow rate of the supplied gas and enhance the sputter removal effect. Further, the coil liner is bent at a predetermined location so that the tip of the torch can be moved to a narrow place by operation of the robot.

[0004]

In the torch for a welding machine according to the above-mentioned conventional construction, when a cylindrical nozzle is screwed to an insulating member previously screwed to a tip member,
An air blow tube extending from the cylindrical nozzle as a gas supply may interfere with the bent coil liner.
Therefore, if the air blow tube is arranged at a position where it does not interfere, the fixing between the cylindrical nozzle and the insulating member becomes uncertain.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a welding torch having a gas supply section for supplying a gas for removing spatter from the outside of a nozzle member. The object is to prevent interference between the supply unit and other members.

[0006]

A torch for a gas shielded arc welding machine according to the present invention performs arc welding in a shield gas atmosphere with a wire-like filler material continuously supplied from a filler material supply unit. And a tip member, a cylindrical nozzle member, a cylindrical insulating member, a fixing member, a shield gas supply unit, and a gas supply pipe. The tip member is fixed to the filler material supply section and has a hole for inserting and supporting the filler material. The cylindrical nozzle member is arranged around the tip member at an interval. The cylindrical insulating member is
It is arranged between the base of the tip member and the base of the nozzle member, is fixed to the tip member in a non-rotatable manner, and has a tip outer peripheral surface in contact with the inner peripheral surface of the nozzle member. The fixing member fixes the insulating member and the nozzle member. The shielding gas supply unit
A shield gas is supplied between the tip member and the nozzle member. The gas supply pipe is fixed to the outer periphery of the nozzle member so as to supply a gas for removing sputter between the tip member and the nozzle member.

[0007] In the insulating member and the nozzle member,
The contact surface has a tapered surface that decreases in diameter in the torch tip direction.
ing. A screw is formed on the outer peripheral surface on the base side of the nozzle member.
Have been. The fixing member is arranged on the outer peripheral side of the base of the nozzle member.
A cylindrical member placed on the inner peripheral surface of the nozzle member.
A screw to be screwed into the jig is formed. The fixing member is the same as the screw
The contact surfaces of the insulating member and the nozzle member are
The nozzle members are urged together to fix the nozzle member to the insulating member.

It is preferable that a chamfered portion is formed on the base side of the tapered surface of the insulating member, and a chamfered portion that contacts the chamfered portion of the insulating member is formed on the base of the nozzle member.

[0009]

The welding material supported by the tip member is continuously supplied to the torch for a gas shielded arc welding machine according to the present invention at the time of welding, and the welding material is supported by the shielding gas supply section. The shielding gas is supplied between the section and the nozzle section. As a result, the arc and the weld metal at 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, gas is supplied between the tip member and the nozzle member from the outside of the nozzle member by the gas supply pipe, and the spatter attached to each member is blown off. Here, since the gas supply pipe is provided outside the nozzle member, the flow rate of the gas is increased and the sputter removal effect is improved.

At the time of assembling, first, the chip member is fixed to a filler supply section (for example, the tip of a coil liner). Subsequently, the cylindrical insulating member is non-rotatably fixed to the tip member. Here, the inner peripheral surface of the cylindrical nozzle member is brought into contact with the outer peripheral surface of the cylindrical insulating member. At this time, for example, if the gas supply pipe interferes with the coil liner or the like, the cylindrical nozzle member may be rotated by a predetermined angle to avoid the interference between the two. In this state, replace the screw of the fixing member with the screw of the nozzle member.
Screwed into. In this way, the rotation of the fixing member
The operation is easy because the chisel and insulating member are fixed.
You. In addition, the release by the fixing member is easy.

As described above, after the nozzle member and the insulating member are securely fixed, interference between the gas supply pipe and other members is further prevented. Since the insulating member and the nozzle member is in contact with small tapered surface of the diameter to the torch tip direction,
The sealing property between the two is improved. When the chamfered portion of the insulating member is in contact with the chamfered portion of the nozzle member, foreign matter such as dust is unlikely to enter between them. As a result, both chamfered portions are less likely to be damaged, and the sealing performance is improved. Fixed part
At the end opposite to the tip of the torch, project radially inward.
An annular abutting part is formed so that the gas shield
It is preferable that the torch for workpiece welder is further equipped with a snap ring.
Good. The retaining ring is located on the outer peripheral surface of the insulating member.
Installed on the opposite side of the torch tip direction,
Abutting on the side of the torch tip
It is a member for restricting the movement to.

When the insulating member and the nozzle member are in contact with each other with a tapered surface having a smaller diameter in the direction of the tip of the torch, the sealing property between the two is improved. When the chamfered portion of the insulating member is in contact with the chamfered portion of the nozzle member, foreign matter such as dust is unlikely to enter between them. As a result, both chamfered portions are less likely to be damaged, and the sealing performance is improved.

[0013]

FIG. 1 shows an inert gas shielded arc welding machine 1 according to an embodiment of the present invention.
And a gas supply device 3, a wire supply device 4, and a torch 5. The welding power supply 2 is for generating a DC welding current from a three-layer 200 volt AC power supply. The welding power source 2 includes a control unit 14. Further, an earth electrode 16 is connected to the welding power source 2.

The gas supply device 3 forms an shielding gas by mixing an argon gas cylinder 6 filled with high-pressure argon gas, a carbon dioxide gas cylinder 7 filled with high-pressure carbon dioxide gas, and argon gas and carbon dioxide gas. And a mixing chamber 8. An argon gas flow controller 9 is arranged between the argon gas cylinder 6 and the mixing chamber 8. Further, a carbon dioxide gas flow regulator 18 is arranged between the carbon dioxide gas cylinder 7 and the mixing chamber 8. A mixing prevention circuit 19 is connected to the mixing chamber 8 via a pipe and a rubber hose. An air source (not shown) including a high-pressure compressor that generates compressed air of 1 MPa, for example, is also connected to the mixing prevention circuit 19.

The wire supply device 4 includes a wire reel mounting portion 12 for mounting a wire reel 11 around which a welding wire is wound, and a feed roller 1 for feeding the welding wire wound around the wire reel 11 into the torch 5.
3 is provided. The feed roller 13 supplies the welding wire to the torch 5 at a constant speed with respect to the welding speed.

The torch 5 includes a coil liner 20 for inserting a welding wire, and a torch nozzle 21 attached to a tip of the coil liner 20. A hole 20a is formed in the coil liner 20. At the base end of the coil liner 20, the above-described mixing prevention circuit 19 is provided.
Rubber hose 17 is connected. The tip of the coil liner 20 is bent in one direction so that the tip of the torch 5 can be moved to a narrow place by operation of the robot.

As shown in FIGS. 2 and 3, the torch nozzle 21 is mainly a cylindrical nozzle body 22 made of oxygen-free copper.
A wire support 23 (tip member) fixed to the tip of the coil liner 20 and arranged concentrically inside the nozzle body 22; a base of the nozzle body 22 and the wire support 23
And a fixing nut 26 for fixing the insulating tube 25 and the nozzle body 22 to each other.

A screw 22a is formed on the outer peripheral surface on the base side of the nozzle body 22. Further, two air blow tubes 24 are fixed to an intermediate portion of the nozzle body 22.
The air blow pipe 24 extends rearward from the nozzle body 22. An air supply hole 24 a is formed in the air blow pipe 24. The hole diameter of the air supply hole 24a is 5 mm. The two air blow pipes 24 join and are further connected to the mixing prevention circuit 19 via a rubber hose (not shown). The nozzle body longitudinally rearward inner peripheral surface has a tapered surface 22 whose diameter decreases as it goes forward in the longitudinal direction.
c. The rear portion in the longitudinal direction of the tapered surface 22c is
The chamfered portion 22d has a sharp corner.

At the tip end side opening of the nozzle main body 22, a cylindrical carbon covering portion 22b with a lip is screwed. The covering portion 22b 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 22b is screwed to the nozzle body 22, it is detachable. The wire support part 23 is the nozzle body 2
2, an annular space 34 is secured. The wire support 23 includes 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. In the contact chip 23b,
A wire hole 23c having a diameter substantially equal to the wire diameter and extending in the torch longitudinal direction is formed. The wire hole 23c supports the welding wire movably in the torch longitudinal direction. The wire support 23 is electrically connected to the welding power source 2 and functions as a welding electrode. A hole 23d having a larger diameter than the wire hole 23c is formed in the tip body 23a of the wire support portion 23.
Are formed inside. The hole 23d communicates with the hole 20a of the coil liner 20. Eight communication holes 23e communicating with the space 34 are formed in the tip body 23a on the tip side of the hole 23d. The diameter of each communication hole 23e is 2 mm.

The insulating tube 25 is made of a cylindrical metal part 27 made of brass.
And a resin portion 28 integrally formed inside the metal portion 27. A resin retaining ring 29 is fixed to the outer peripheral surface of the middle part of the metal part 27. Further, the outer peripheral surface on the distal end side of the metal portion 27 has a tapered surface 31 whose diameter decreases toward the distal end side.
It has become. Behind the tapered surface 31, there is a chamfer 32 having a sharp corner. The tapered surface 31 is in contact with the tapered surface 22c of the nozzle body 22. The chamfer 32 is in contact with the chamfer 22d of the nozzle body 22.

The fixing nut 26 has a screw 35 formed on the inner peripheral surface on the front side in the longitudinal direction, and the screw 35 is screwed to the screw 22 a of the nozzle body 22. Further, an annular abutting portion 36 protruding radially inward is formed at a longitudinally rear end of the fixing nut 26. This contact portion 36
Abuts against a retaining ring 29 fixed to the insulating cylinder 25 from the rear side in the longitudinal direction. As shown in FIG.
With the nozzle attached, the nozzle body 22 and the insulating cylinder 25
Are pressed in the longitudinal direction. As described above, the tapered surfaces and the chamfered portions are in strong contact with each other, so that they cannot be relatively rotated. In addition, since the tapered surfaces and the chamfered portions are in strong contact with each other, the sealing properties at the contact portions are improved, and foreign matter is less likely to enter. Since foreign matter is hardly penetrated, the contact portion between the two members is hardly damaged, and the sealing property is maintained for a long time.

The mixing prevention circuit 19 is provided for controlling the air supplied from the air source and the shielding gas supplied from the gas supply device 3 and for preventing the mixing of the air and the shielding gas. As shown in FIG. 4, the mixing prevention circuit 19 includes shield gas on-off valves 39 and 40 for opening and closing the shield gas supplied from the gas supply device 3, and air on-off valves 41 and 40 for opening and closing high-pressure air from an air source, respectively. 4
2 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, 40 are, for example, direct-acting two-port valves, and the air on-off valves 41, 42 are, for example, pilot-type two-port piston drive valves. The mixing prevention valves 43 and 44 are
For example, a three-port poppet type valve. The shield gas on-off valve 39 and the mixing prevention valve 44 are connected to a connection port (not shown) of the coil liner 20 via the rubber hose 17. In addition, the shield gas on-off valve 40 and the mixing prevention valve 4
Reference numeral 3 is connected to the air blow pipe 24 via a rubber hose.

Next, the operation of the above embodiment will be described. In this embodiment, the spatter is removed every time one welding is completed. Specifically, one cycle is welding (shield gas injection) → spatter removal (high-pressure air injection) → removal of residual air (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 is supplied to the air blow pipe 24 and the coil liner 20 by opening the shield gas on-off valves 39 and 40. The shielding gas is supplied to the air supply hole 24a and the tip body 23a.
From the communication hole 23e of the nozzle body 22 and further moves toward the tip of the torch through the annular space 34. As a result, the shield gas supplied from the gas supply device 3 is jetted from the tip of the torch nozzle 21. Thereby, the welding wire and the air are shut off during the welding operation.

At the time of the above welding, the mixing prevention valves 43, 44
Are exhausted. 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. If spatter occurs during this welding,
A part thereof adheres to each member such as the nozzle body 22 and the wire support 23. In addition, since the coating part 22b is made of carbon, spatter does not easily adhere.

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 is supplied from the air source to the air blow pipe 24 and the coil liner 20. In this way, the air supplied into the space 34 blows off the spatters attached to the respective members. Air blow pipe 2
4, the flow rate of air is increased, so that the effect of removing spatter is improved. Further, since the flow rate of the air is large, the cooling degree of each member is improved. as a result,
The amount of spatter adhered is greatly reduced.

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 shielding gas is supplied to the air blow pipe 24 and the coil liner 20. This shielding gas
The air remaining in the air supply hole 24a, the annular passage 34, and the hole 23d 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 pipe 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. Next, the assembling operation will be described. First, the wire support 23 is screwed to the tip of the coil liner 20. Subsequently, the insulating cylinder 25 is screwed to the outer periphery of the wire support 23. Further, the insulating cylinder 25 is inserted into the longitudinal rear end of the nozzle body 22. At this time, the tapered surface 22c and the chamfered portion 22d of the nozzle body 22 come into contact with the tapered surface 31 and the chamfered portion 32 of the insulating cylinder 25, respectively. At this time, if the air blow pipe 24 integrally fixed to the nozzle body 22 interferes with the coil liner 20, the nozzle body 22 is rotated by a predetermined angle to avoid interference between the two. Finally, the fixing nut 26 is attached. The fixing nut 26 is attached to the coil liner 2 from the rear side in the longitudinal direction.
Then, the screw 35 is screwed into the screw 22a of the nozzle body 22. As the screwing proceeds, the contact portion 36 of the fixing nut 26 comes into contact with the retaining ring 29, and moves the insulating cylinder 25 forward in the longitudinal direction. Therefore, the tapered surface 31 and the chamfered portion 32 of the insulating cylinder 25 are connected to the tapered surface 2 of the nozzle body 22.
2c and the chamfered portion 22d are strongly pressed. Thereby, the nozzle main body 22 cannot be rotated by the insulating cylinder 25.

As described above, the nozzle body 22 and the insulating cylinder 2
5 and the air blow pipe 24
And the coil liner 20 are prevented from interfering with each other. Since the nozzle body 22 and the insulating cylinder 25 are fixed by the rotation of the fixing nut 26, the operation is easy. Also, the fixing nut 26
Can be easily released. [Modifications] (a) In the above embodiment, spatters are removed each time welding is performed. However, spatters may be removed after performing welding several 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, another gas such as nitrogen gas may be used. (C) In the above embodiment, the tip of the insulating cylinder 25 may be rounded and chamfered. This can further reduce spatter adhesion.

[0029]

According to the torch for a gas shielded arc welding machine according to the present invention, at the time of assembling, first, the tip member is fixed to the filler supply portion (for example, the tip of the coil liner). Subsequently, the cylindrical insulating member is non-rotatably fixed to the tip member. Here, the inner peripheral surface of the cylindrical nozzle member is brought into contact with the outer peripheral surface of the cylindrical insulating member. At this time, for example, if the gas supply pipe interferes with the coil liner, etc.
It is sufficient to rotate the cylindrical nozzle member by a predetermined angle to avoid interference between the two. In this state, the nozzle member is fixed to the insulating member by the fixing member.

As described above, while the nozzle member and the insulating member are securely fixed, interference between the gas supply pipe and other members is further prevented. When the fixing member is a cylindrical member,
The screw of the fixing member is screwed into the screw of the nozzle member with the engaging portion of the fixing member engaged with the tip member. As described above, since the nozzle member and the insulating member are fixed by the rotation of the fixing member, the operation is easy. In addition, the release by the fixing member is easy.

When the insulating member and the nozzle member are in contact with each other with a tapered surface having a smaller diameter in the direction of the tip of the torch, the sealing property between the two is improved. When the chamfered portion of the insulating member is in contact with the chamfered portion of the nozzle member, foreign matter such as dust is unlikely to enter between them. As a result, both chamfered portions are less likely to be damaged, and the sealing performance is improved.

[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 side view of the torch.

FIG. 3 is a side view of a torch partially cut longitudinally.

FIG. 4 is a circuit diagram of a mixing prevention circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inert gas shield arc welding machine 3 Gas supply device 5 Torch 20 Coil liner 21 Torch nozzle 22 Nozzle main body 23 Wire support part 24 Air blow tube 25 Insulation cylinder 26 Fixing nut

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B23K 9/29

Claims (3)

(57) [Claims] 1. A torch for a gas shielded arc welding machine for performing arc welding in a shield gas atmosphere with a wire-like filler material continuously supplied from a filler material supply unit, A tip member fixed and having a hole for inserting and supporting the filler material, a cylindrical nozzle member disposed around the tip member at an interval, a base of the tip member, and the nozzle member A cylindrical insulating member fixed to the tip member in a non-rotatable manner and having an outer peripheral surface in contact with an inner peripheral surface of the nozzle member; and fixing the insulating member and the nozzle member. A fixing member, a shield gas supply unit for supplying a shield gas between the tip member and the nozzle member, and a sputter removal gas between the tip member and the nozzle member. As such, a gas supply pipe which is fixed to the outer periphery of the nozzle member, in the insulating member and the nozzle member, each abutment surface
It has a tapered surface with a smaller diameter in the direction of the torch tip.
A screw is formed on the outer peripheral surface on the base side of the nozzle member.
The fixing member is disposed on the outer peripheral side of the base of the nozzle member.
Cylindrical member, the inner peripheral surface of the nozzle member
A screw to be screwed into the screw is formed, and the fixing member is fixed to the insulating portion by screwing the screws together.
Urging both contact surfaces of the material and the nozzle member to each other,
A torch for a gas shielded arc welding machine , wherein a nozzle member is fixed to the insulating member . 2. A surface on the tapered surface base side of the insulating member.
A take-out portion is formed, and a front portion is provided at a base portion of the nozzle member.
A chamfered portion that contacts the chamfered portion of the insulating member is formed.
The gas shielded arc welding machine according to claim 1, wherein
For torch. 3. The end of the fixing member opposite to the torch tip direction.
Has an annular abutment projecting radially inward.
Is, the torch tip of the abutting surface at the outer peripheral surface of the insulating member
Attached on the opposite side to the direction, the torch tip of the contact part
By contacting the side, the fixing member moves toward the tip of the torch.
The contractor is further equipped with a retaining ring to regulate the movement of
The toe for a gas shielded arc welding machine according to claim 1 or 2.
Ji.