JPH0938778A - Arc welding torch and its arc welding cable - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide an arc welding torch in which a stable welding arc is recovered and maintained even when the time during which the welding wire is in contact with the workpiece is not constant. And A flexible liner 1 is formed by spirally winding a metal wire, which is a passage for a welding wire 3 through a flexible hollow cable 2.
The liner 1 built in the central tube 2c of No. 1 was sparsely wound at one or several places, and the other part was tightly wound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc welding torch used for welding operation and a cable for the arc welding.

[0002]

2. Description of the Related Art A conventional arc welding torch and its arc welding cable will be described below.

In FIG. 2, reference numeral 2 denotes a flexible hollow cable, which is composed of an insulating coating 2a for insulating and protecting the outer periphery, a conductor 2b for supplying a welding current, and a central tube 2c for providing a hollow portion. There is.

Reference numeral 1 denotes a flexible liner incorporated in a hollow cable 2, which serves as a passage for a welding wire 3,
Usually, a metal wire is wound in a spiral shape so as to have flexibility. Further, by tightly winding this, the rigidity is increased and the fluctuation of the wire feeding speed due to the deflection of the liner 1 is reduced.

At one end of the hollow cable 2, a conductive connecting fitting 6 for connecting with a wire feeding device 7 is electromechanically coupled.

Further, a gas inlet fitting 8 is processed on this. A torch body 11 is connected to the other end of the hollow cable 2, and a contact tip 5 having a hole having an inner diameter slightly larger than the diameter of the welding wire 3 is coupled to the tip of the torch body 11 by screw fastening or the like. .

Further, the nozzle 4 is attached to the torch body 11 so as to enclose the contact tip 5 concentrically.

Reference numeral 9 indicates a welding arc generated between the object to be welded 10 and the welding wire 3. The operation of the arc welding torch configured as above will be described below. First, the welding wire 3 sent out from the wire feeding device 7 passes through the liner 1, is sent to the torch body 11 connected to the hollow cable 2, passes through the contact tip 5 attached to the torch body 11, and welds. The welding current is supplied to the welding arc portion 9 generated between the work wire 3 and the object to be welded 10, and the welding current flows from the contact fitting 5 through the conductor 2b of the cable 2 hollow from the connection fitting 6 and the torch body 11. Contact power is supplied to the working wire 3. On the other hand, the shield gas for cutting off the welding arc portion 9 from air or the like is supplied from the gas inlet fitting 8 to the central tube 2 of the hollow cable 2.
is supplied to the gap between c and the liner 1, and the torch body 11,
It is supplied to the welding arc portion 9 generated between the welding wire 3 and the workpiece 10 through the nozzle 4.

In addition to this, a liner (conduit tube) in a welding torch is formed by spirally winding a metal wire, one part of which is loosely wound and the other of which is closely wound (Japanese Patent Publication No. 2-24189 gazette).

[0010]

However, in the above-mentioned conventional structure, the welding wire 3 normally repeats contact (short circuit) and non-contact (arc state) with the workpiece 10 several times to several hundred times per second. In the welding arc portion 9 that is being welded, the welding wire 3 is to be welded due to factors such as a change in the distance between the contact tip 5 and the workpiece 10 The time of contact with the object 10 is not constant, and sometimes becomes longer.
Since the welding wire 3 is continuously fed from the instant wire feeding device 7 at a constant speed, the welding wire 3 receives a compressive force in the axial direction. Here, when the entire liner 1 is closely wound, the rigidity of the liner 1 is strong, so that when the welding wire 3 receives a strong compressive force in the axial direction,
The welding wire 3 bends. This bent welding wire 3
When the welding arc portion 9 is in the arc state, the axial compressive force is suddenly released and is fed to the workpiece 10 at an excessive speed. The short-circuited state occurs, and therefore the time of contact with the object 10 to be welded further increases.

This is repeated, resulting in the problem that the welding arc becomes unstable.

Further, the one disclosed in Japanese Patent Publication No. 2-24189 mentioned above relates to a torch main body portion whose shape does not change, and its purpose is to stabilize the arc, but more specifically, to vibrate the liner. Was to prevent.

The present invention solves the above-mentioned conventional problems, and the welding wire 3 causes the welding object 10 to be welded due to various factors.
It is an object of the present invention to provide an arc welding torch that prevents a rapid change in the wire feeding speed and recovers and maintains a stable welding arc even when the time during which the wire is in contact is not constant and sometimes becomes long. To do.

[0014]

In order to achieve this object, an arc welding cable of the present invention comprises a flexible hollow cable and a flexible cable which is inserted into the hollow portion of the cable and serves as a passage for a welding wire. And a liner having a property, the liner is formed by spirally winding a metal wire, and one or a plurality of places is loosely wound and the other part is closely wound.

The arc welding torch of the present invention comprises the above arc welding cable.

[0016]

Due to various factors, the time during which the welding wire is in contact with the object to be welded is not constant, and sometimes the welding wire is subjected to a strong axial compressive force when it becomes long. At this time, the loosely coiled part of the liner flexes slightly in the gap between the hollow cable and the liner in the radial direction,
This serves as a cushioning material and absorbs the compressive force of the welding wire, so it is possible to prevent a rapid change in the wire speed at the welding arc portion, thereby maintaining a stable welding arc. .

On the other hand, when the entire liner is sparsely wound, since the rigidity of the entire liner is weak, deflection occurs over the entire length of the liner cable in the gap between the center tube of the hollow cable and the liner during normal welding. The feeding speed of the work wire becomes irregular, which causes the welding arc to become unstable. Therefore, by partially winding the liner and closely winding the other, during normal welding, due to the action of the tightly wound tightly wound portion, the bending of the liner does not occur over the entire length of the cable, and the welding wire is not fed. The feed rate is stable. Also, due to various factors, the time during which the welding wire is in contact with the object to be welded is not constant and sometimes becomes long, but in this case, the loosely coiled part with weak rigidity is slightly bent, Prevents rapid changes in the feeding speed of the welding wire. By thus stabilizing the feeding speed of the welding wire, a stable welding arc can be maintained.

Normally, this sparsely wound portion is effective in maintaining the arc stability if it is owned by one, but depending on the diameter and rigidity of the welding wire and the cable routing state, several sparsely wound portions are provided. In some cases, it becomes an appropriate buffer, and it may be effective in the stability of the arc.

[0019]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 2 denotes a flexible hollow cable, which is composed of an insulating coating 2a for insulating and protecting the outer periphery, a conductor 2b for supplying a welding current, and a central tube 2c for providing a hollow portion. There is.

Reference numeral 1 denotes a flexible liner incorporated in a hollow cable 2, which serves as a passage for a welding wire 3.
The liner 1 has flexibility by winding a metal wire in a spiral shape. Further, in this winding, the portion A is loosely wound, and the other portion (portion B) is closely wound.

At one end of the hollow cable 2, a conductive connecting fitting 6 for connecting with the wire feeding device 7 is electrically coupled. Further, a gas inlet fitting 8 is processed on this. The torch body 11 is connected to the other end, and the contact tip 5 is coupled to the tip of the torch body 11 by screw fastening or the like. Further, the nozzle 4 is attached to the torch body 11 so as to enclose the contact tip 5 concentrically.

Reference numeral 9 indicates a welding arc generated between the object to be welded 10 and the welding wire 3. The operation of the arc welding torch configured as above will be described below. First, the welding wire 3 sent out from the wire feeding device 7 passes through the liner 1 and is sent to the torch body 11 connected to the hollow cable 2, and passes through the contact tip 5 attached to the torch body 11 to weld the wire. It is supplied to the welding arc portion 9 generated between the work wire 3 and the workpiece 10.

During normal welding, the welding wire 3 delivered from the wire feeder 7 tends to bend the entire liner 1 in the radial direction when passing through the liner 1. But,
The liner 1 is closely wound with high rigidity over almost the entire length, and since the liner 1 hardly bends, the welding wire 3 delivered from the wire feeder 7 is transmitted to the welding arc portion 9 at a constant speed. To be As a result, the wire feeding speed at the welding arc portion 9 becomes constant.

Further, due to various factors, the time during which the welding wire 3 is in contact with the object 10 to be welded is not constant, and at the moment when it becomes longer, the welding wire 3 is fed from the wire feeding device 7 at a constant speed. Are continuously fed, the welding wire 3 receives a force in the compression direction in the axial direction. At this time, the loosely-wound portion (A portion) of the liner 1 which is weak in rigidity slightly bends in the direction C in the gap between the central tube 2c of the hollow cable 2 and the liner 1, and this serves as a cushioning material for welding. In order to absorb the compressive force of the welding wire 3, the welding arc portion 9
Thus, it is possible to prevent the welding wire 3 from being fed to the workpiece 10 at an excessive speed when the arc state (non-contact) occurs.

With the above operation, a stable wire feeding speed is maintained at the welding arc portion 9. Also, the welding current is
The connecting wire 6 passes through the conductor 2b of the hollow cable 2, the torch body 11, and the contact tip 5 to the welding wire 3
Is contact-powered. On the other hand, the shield gas that shuts off the welding arc portion 9 from air or the like is supplied from the gas inlet fitting 8 to the gap between the central tube 2c of the hollow cable 2 and the liner 1,
It is supplied to the welding arc portion 9 generated between the welding wire 3 and the workpiece 10 through the torch body 11 and the nozzle 4.

[0027]

As described above, the present invention has a simple structure,
You can always maintain a stable wire feed rate, which allows
Since the stability of the welding arc can be greatly improved, the industrial benefit is great.

[Brief description of drawings]

FIG. 1 is a configuration diagram including a partial cross section of an arc welding torch and an arc welding cable according to an embodiment of the present invention.

FIG. 2 is a configuration diagram including a partial cross section of a conventional arc welding torch and its arc welding cable.

[Explanation of symbols]

 1 Liner 2 Hollow cable 2a Insulation coating 2b Conductor 3 Welding wire 4 Nozzle 5 Contact tip 6 Connection metal fitting 7 Wire feeder 8 Gas inlet metal fitting 9 Welding arc 10 Workpiece 11 Torch body

Front page continued (72) Inventor Kazaburo Kawabata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Takayuki Ida, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A flexible hollow cable, and a flexible liner that passes through the hollow portion of the cable and serves as a passage for a welding wire. The liner is formed by spirally winding a metal wire. An arc welding torch provided with a cable for arc welding that is formed and has one or a plurality of loosely wound windings and the other portion closely wound. 2. A flexible hollow cable, and a flexible liner that passes through the hollow portion of the cable and serves as a passage for a welding wire. The liner is formed by spirally winding a metal wire. A cable for arc welding that is formed and has one or more parts sparsely wound and the other part closely wound.