JPH07155955A - Welding torch - Google Patents

Abstract

PURPOSE:To eliminate a long distance reciprocation of a welding torch or a coil at the time of removing spatter, and to shorten a loss time caused on a spatter removing process. CONSTITUTION:This torch has a torch body 1, an electromagnetic 3 which is installed on the outer periphery of the torch body 1 and movable in the axial direction, and a driving means 2 which drives the coil 3 forth and back so that the coil 3 is placed at an advanced position projecting from the tip end of the torch body 1 or the tip end of the torch body 1 is placed at the retracted position projecting from the coil 3. Because only energizing the coil 3 at the advanced position can remove the spatter 6, the torch body 1 can execute the spatter removing process at the welding position as it is, and it can shorten the loss time caused on the long distance movement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding torch used for arc welding, and more particularly to a welding torch having a device for removing molten metal particles (spatter) attached to the tip.

[0002]

2. Description of the Related Art In arc welding, welding is performed by generating an arc between a welding wire and a material to be welded to melt the welded portion. In this arc welding, there is a phenomenon in which spatter is scattered from the molten portion during welding, and spatter adheres and accumulates on the tip of the welding torch.

However, it is known that the use of such a welding torch in which spatter is deposited causes various troubles in the welding operation. For example, in the case of gas shielded arc welding, the flow of the shield gas is disturbed by the accumulated spatter, and air may be mixed into the arc or molten metal to cause a welding defect. Therefore, it is necessary to remove the spatter attached to the welding torch.
Japanese Patent Publication No. 86, Japanese Utility Model Publication No. 58-47381, etc. describe a method of mechanically removing spatter using a brush, a rotary blade, or the like. However, the mechanical removal method may damage the nozzle at the tip of the torch, and scratches on the nozzle may cause new problems such as spatter being more likely to accumulate.

Japanese Patent Publication No. 3-6867 discloses a method in which the tip of the welding torch and the electromagnetic coil are brought close to each other and the spatter is sucked and removed by the magnetic flux generated in the coil. According to this method, since no mechanical force is applied to the welding torch body, damage and scratches are prevented and the life of the welding torch can be extended.

[0005]

[Problems to be Solved by the Invention] However, Japanese Patent Publication No. 3-6867
In the method disclosed in the publication, the welding torch and the coil are separate bodies. Therefore, when removing the spatter, it is necessary to bring them close to each other, and in addition to the time required for removing the sputter, time is required for the movement, and there is a problem that the loss time is long.

For example, when welding a large structure such as an automobile by robot welding, the teaching of the robot is uniform. Therefore, the coil is not necessarily installed near the welding line, and a long distance reciprocating movement is required to bring the welding torch and the coil close to each other when removing spatter, which causes a large loss time. Further, for example, in the case of automatic welding, the welding torch is fixed or movable only in one direction by a cylinder device or the like. Therefore, in order to bring the coil and the torch close to each other, it is necessary to further install an actuator for moving the welding torch or the coil, and moreover, a place for installing the actuator and a space for moving the actuator are required. It is often difficult to apply within the line.

The present invention has been made in view of the above circumstances, and an object thereof is to eliminate the need for long-distance reciprocating movement of a welding torch or coil when removing spatter, and to reduce the loss time due to the spatter removing process. .

[0008]

A welding torch according to the present invention for solving the above-mentioned problems comprises a substantially rod-shaped torch body, an electromagnetic coil provided on the outer periphery of the torch body and movable in the axial direction of the torch body, and a coil. Drive means for driving the coil back and forth such that the coil is moved forward and backward so as to project from the tip of the torch or at the retracted position where the tip of the torch body projects from the coil.

[0009]

In the welding torch of the present invention, at the time of welding, the tip of the torch body projects from the coil to the retracted position, and the torch tip projecting from the coil performs welding as usual. Then, when spatter is deposited on the tip of the torch and it is necessary to remove it, the coil is driven forward by the drive means to the forward position where it is projected from the torch tip. Then, when a large current is momentarily applied to the coil, the spatter can be removed from the tip of the torch by the attraction force generated by the magnetic flux passing through the coil.

[0010]

EXAMPLES The present invention will be specifically described below with reference to examples. Figure 1
The welding torch of one Example of this invention is shown in FIG. This welding torch is composed of a torch body 1, an air cylinder device 2 provided around the torch body, and an electromagnetic coil 3 provided on the inner peripheral surface of the tip of a cylindrical piston 21 of the air cylinder device 2. ing.

As shown in FIG. 2, the torch body 1 has a cylindrical torch nozzle 10, a cylindrical ceramic nozzle 11 provided at the tip of the torch nozzle 10, and a torch nozzle 10.
And a power supply tip 12 coaxially arranged inside the ceramic nozzle 11. The welding wire 4 penetrates through the center of the power feeding tip 12 and can be led out from the tip of the power feeding tip 12. Further, a gas inlet 13 (not shown) is provided on the side wall of the torch nozzle 10,
The shield gas is allowed to flow into the torch nozzle 10 and the ceramic nozzle 11 and flow out from the tip of the ceramic nozzle 11 toward the welded portion.

The air cylinder device 2 as the driving means is
It is composed of a cylinder 20 fixed to the torch body 1 and arranged coaxially with the torch body 1, and a piston 21 arranged in the cylinder 20 and movable back and forth in the axial direction of the torch body 1. An upper end port 22 and a lower end port 23 that communicate the outside with the inside of the cylinder are formed on both side walls of the cylinder 20, and air can be supplied to the upper end port 22 and the lower end port 23, respectively.

That is, when air is supplied from the upper end port 22, the piston 21 is exhausted while exhausting from the lower end port 23.
Moves downward and is driven forward in a direction projecting from the cylinder 20. Further, when air is supplied from the lower end port 23, the piston 21 moves upward while exhausting from the upper end port 22, and is driven backward in the direction of being housed in the cylinder 20.

An electromagnetic coil 3 is coaxially provided on the inner peripheral surface of the tip of the piston 21, and the electromagnetic coil 3 can be energized by a power source 5. A cylindrical ferromagnetic body 30 (made of carbon steel or oxide ferrite) is fixed to the inner peripheral surface of the electromagnetic coil 3. This ferromagnet 30
Has a function of strengthening the magnetic field generated in the electromagnetic coil 3.

At the forward position where the piston 21 is driven forward, the electromagnetic coil 3 is further projected from the tip of the ceramic nozzle 11 as shown in FIG. 3, and at the retracted position where the piston 21 is driven backward, as shown in FIG. As shown in FIG. 3, the ceramic nozzle 11 is configured so as to project from the electromagnetic coil 3. Now, with the welding torch of this embodiment configured as described above, welding is performed in the retracted position shown in FIG. That is, the gas shield arc welding is performed by the discharge between the welding wire 4 and the welding portion while supplying the shielding gas (Ar or CO ₂ ) from the gas inlet (not shown) and flowing out from the tip of the ceramic nozzle 11.

As the welding work progresses, spatters 6 scattered from the welded portion, as shown in FIG.
1 is deposited on the tip and inner peripheral surface. Therefore, the flow of the shield gas at the torch outlet is disturbed, the shield effect is reduced, air is mixed in the arc or molten metal, and defects such as blowholes that remain in the weld may occur.

Therefore, in the welding torch of this embodiment, the deposits of spatter are regularly removed as follows. After the welding is stopped at the time of removing the spatter, air is supplied to the upper end port 22 of the cylinder 20 with the torch body 1 hardly moving at the welding position. As a result, the piston 21 is driven forward, and as shown in FIG.
Is an advanced position protruding from the tip of the ceramic nozzle 11. Then, a current is supplied from the power supply 5 to the electromagnetic coil 3.

Then, a magnetic field is generated in the electromagnetic coil 3, and the magnetic flux is strengthened by the presence of the ferromagnetic body 30. Therefore, as shown in FIG. 3, the attractive force to the ferromagnetic material 30 acts on the sputter, and the sputter 6 deposited can be removed by separating from the ceramic nozzle 11.
After removing the spatter, the air is supplied to the upper end port 22.
By switching from to the lower end port 23, the piston 21 is set to the retracted position, and welding can be restarted at that position.

Although the ferromagnetic body 30 is provided in this embodiment, the ferromagnetic body 30 is not essential, and the same effect can be obtained without providing it. That is, according to the welding torch of the present embodiment, it is possible to easily remove the spatter deposited at the position at the time of welding, so that it is possible to reduce the loss time for movement. In addition, since welding defects due to the accumulation of spatter can be prevented in advance, the number of man-hours such as rework can be significantly reduced.

[0020]

That is, according to the welding torch of the present invention,
It is possible to remove spatter deposited in a non-contact manner without applying a mechanical external force. Therefore, damage to the nozzle can be prevented and the life can be extended. Since the electromagnetic coil is provided integrally with the torch body, it is not necessary to move the torch body and the coil for a long distance at the time of removing the spatter, the loss time required for the movement can be shortened, and the space for the actuator is also unnecessary. Therefore, man-hours and required space can be reduced, and welding cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state of a welding torch according to an embodiment of the present invention during welding.

FIG. 2 is an enlarged sectional view of a main part of a welding torch according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state of the welding torch according to one embodiment of the present invention when deposit spatter is removed.

[Explanation of symbols]

1: Torch body 2: Air cylinder device (driving means) 3: Electromagnetic coil 4: Welding wire 6: Sputter 11: Ceramic nozzle 20: Cylinder 3
0: Ferromagnetic material

Claims (1)

[Claims] 1. A substantially rod-shaped torch body, an electromagnetic coil which is provided on the outer periphery of the torch body and is movable in the axial direction of the torch body, and a forward position in which the coil projects from the tip of the torch or from the coil. A welding torch, comprising: a driving unit that drives the coil back and forth so that the tip of the torch body is in a retracted position.