JPH07236974A - Welding torch - Google Patents

Abstract

PURPOSE:To straighten the wire by feeding the wire along the recessed groove provided in a ceramics guide member, and pressing the wire into the recessed groove to reduce the play of the wire in the guide hole. CONSTITUTION:The wire 6 is guided along a V-shaped groove 20 provided in a ceramics guide member, and reaches the tip of the wire torch, and then, reaches the molten pool of the base metal. The tip of the wire 6 is brought into contact with the base metal, and the base metal is energized and heated between the energizing tip and the base metal. The highly heated and softened wire 6 is pressed against the V-shaped groove 20 by a pressing member 25 consisting of the electrically insulated, heat resistant, and wear resistant ceramic member in the middle, and the wire 6 which is likely to be bent itself is straightened by three sides consisting of the V-shaped groove 20 and the pressing member 25, and fed from the tip of the wire torch.

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 in, for example, an automatic arc welding apparatus, and more particularly to a welding torch suitable for stably guiding and feeding a welding wire to a welding portion. .

[0002]

2. Description of the Related Art FIG. 10 shows the construction of a welding apparatus that has been generally used as a hot wire TIG welding method.

Tungsten electrode 2 in TIG torch 1
The arc power source 4 for DC welding is connected to the base material 3 and the arc 5 is formed in the argon shield gas with the tungsten electrode 2 as the negative electrode. The welding addition wire 6 is guided from the wire feeding device 7 through the conduit 8 and the current-carrying tip 10 and the ceramic guide tip 11 of the wire torch 9 connected to the conduit 8 to the arc forming portion and brought into contact with the base material 3.

One output terminal of the wire heating power source 12 is connected to the current-carrying tip 10 and the other output terminal is connected to the base material 3 so that an electric current is passed through the addition wire 6 so that the current-carrying tip 10 and the base material 3 (extension). ), Joule heat is generated, thereby increasing the melting rate of the addition wire 6. The addition wire 6 is inserted from the outside of the gas shield nozzle 13 at the tip of the TIG torch 1.

Conventionally, even if the wire torch 9 is relatively fixed to the TIG torch 1, if the bending tendency (curvature and bending direction) of the additive wire 6 changes, it is inserted into the molten pool 14 near the tungsten electrode 2. The position of the tip of the added wire 6 fluctuates, the molten state of the wire 6 significantly changes, and the wire 6 often comes into contact with the tungsten electrode 2 to make welding difficult.

Therefore, an insulating ceramic guide 11 is placed at the tip of the current-carrying tip 10 to guide the wire 6 as close to the arc 5 as possible. Still, in order to avoid the ceramic guide tip 11 from being damaged by the arc 5, the wire length from the tip of the guide tip 11 to the molten pool 14 needs to be 15 mm or more, and the variation of the tip position of the wire 6 is suppressed. It was difficult to do.

In order to suppress the variation of the wire tip position,
The inventors previously proposed a ceramic guide chip 15 having a triangular hole, the cross-sectional shape of which is shown in FIG. This is a ceramic wire guide with an equilateral triangular hole having an inscribed circle with a diameter about 0.05 mm larger than the outer diameter of the wire. The wire 6 heated to about 500 to 800 ° C. by Joule heating is restrained by the three sides of the triangle and becomes straight,
It has the function of being sent out without bending. As a result, the wire insertion position is extremely stable and the hot wire TI
It greatly contributed to the stabilization of G welding.

A similar correction effect can be obtained by using a guide chip having a thin round hole having a diameter close to that of the wire. However, foreign matter such as plating scraps adhering to the wire accumulates in the guide chip and causes a wire clogging immediately. Can not. However, when the triangular hole is used, foreign matter such as plating scraps is transported in the spaces at the three corners while restraining the wire 6 on the three sides, so that the wire is not clogged, which is practical.

[0009]

However, in order to manufacture the above-mentioned chip, that is, the guide chip 15 made of ceramics having a triangular hole, it is necessary to manufacture a die having an expensive complicated shape, and the sintering is performed. Due to variations in the amount of shrinkage over time, there remains the problem that it is quite difficult to manufacture the hole shape accurately.

Further, in consideration of the variation of the diameter of the passing wire 6 itself, the inscribed circle of the hole had to be set slightly larger than the wire diameter, so that the wire diameter coincided with the inscribed circle of the hole. There was also a problem that the degree of straightening the wire was smaller than that in the case of being allowed to do so.

In addition, cracks occasionally occurred at the corners of the triangular holes due to thermal shock from an arc or a heated wire.
Further, since the ceramic chip is thin and relatively fragile, when a force is applied from the side to the wire on the exit side, the tip of the chip is often chipped off and damaged, which has been a problem.

It is an object of the present invention to reduce the wire play in the guide hole and straighten the wire.

Another object of the present invention is to provide a guide shape that is easy to manufacture, and to reduce the number of parts that are vulnerable to thermal shock.
It is to provide a ceramic guide having a structure that is more resistant to cracking even when external force is applied.

Still another object of the present invention is to provide a torch structure in which wire energization is performed more reliably and the chip life is long.

[0015]

SUMMARY OF THE INVENTION The above object is to provide a ceramic guide member having a concave groove represented by a V groove for guiding a wire which is being electrically heated, and to feed the wire along the concave groove. And a ceramic member that presses the wire toward the groove side.

The above object is also achieved by disposing a wire energizing tip on the wire inlet side of the ceramic member that presses the wire in the concave groove, and contacting and energizing the wire while pressing the wire in the concave groove ceramic member.

[0017]

Since the wire is pressed into the groove to form, for example, a triangular shape in close contact with the outer diameter of the wire with two ceramic members, the wire heated to a high temperature is straightened and delivered. The ceramic member having the concave groove can be formed by simply cutting the green body or by a simple die which can be manufactured at low cost. Moreover, since the pressing member may be flat, it is easy to manufacture.

Structurally, the margin of manufacturing precision required for these members becomes very large, and the yield is greatly improved. The notch has only the concave groove portion, which is also improved in heat resistance and impact resistance as compared with the triangular hole. Further, when a force is applied to the wire from the lateral direction, the force applied to the guide can be considerably escaped by the action of the spring that presses the pressing member.

Since the current-carrying tip has a structure in which it is constantly pressed against the wire by a spring even if it is worn out to some extent, it is possible to maintain a stable contact current and to keep it for a long time as compared with the case of a normal round-hole current-carrying tip. Extend the life.

[0020]

1 is a view showing an embodiment in which the present invention is applied to a wire torch of a hot wire TIG welding apparatus, showing a structure of a wire torch 16 for hot wire. 2 to 7 are sectional views taken along lines AA to FF shown in FIG.

The wire 6 is fed from the wire feeding device 7 shown in FIG. 10 through the conduit 8 to the torch body 17. Then, the wire 6 passes through the guide hole 18 of the torch body 17 and reaches the tip of the wire torch 16 along the V groove 20 of the V groove member 19, and exits the wire torch 16 to the position shown in FIG.
The molten pool 14 of the base material 3 shown in FIG. V groove member 1
Reference numeral 9 is made of insulating heat-resistant and wear-resistant ceramics such as silicon nitride, and is fixed to the torch body 17 with mounting screws 21h and 21i.

The V groove 20 has an equilateral triangular shape having a depth D to 1.4D, where D is the diameter of the wire 6. Therefore, in the case of a triangular groove having a depth of 1.7 mm, the diameter is 1.
It can be used as is for 2 mm to 1.6 mm wires. The torch body 17 is electrically connected to the output terminal of the wire heating power source 12 shown in FIG. 10, and the wire 6 is energized via the flexible energizing copper plate 22 and the energizing tip 23. The current-carrying tip 23 is pushed toward the V-groove member 19 by springs 24e and 24f to ensure contact current-carrying. At the same time, the life of the current-carrying tip 23 is increased so that it can be used even if the current-carrying tip 23 is slightly worn. ing.

The tip of the wire 6 comes into contact with the base material 3 (not shown), and the wire 6 is electrically heated between the current-carrying tip 23 and the base material 3. In the middle of the process, an insulating heat-resistant and abrasion-resistant material such as silicon nitride is used. The wire 6 softened at high temperature by the pressing member 25 made of a flexible ceramic member is pressed against the V groove 20 and the wire 6 having a bending tendency is pressed against the V groove 20 and the pressing member 25.
Wire torch 1 straightened with 3 sides
6 Send out from the tip. Although the above has described the embodiment applied to the wire torch of the hot wire TIG welding apparatus, the present invention is not limited to the wire torch of the hot wire TIG welding apparatus, but to the wire torch of various hot wire welding apparatuses combined with MAG welding or the like. Can also be applied.

Furthermore, the present invention is not limited to a wire torch for hot wires, but can be applied to a torch for consumable electrode arc welding equipped with a shield nozzle such as MAG welding. In particular, in the case of MAG welding or the like, there is a problem that bead meandering occurs due to a change in the arc target position due to a change in the bending tendency of the wire and a change in the direction of the bending tendency.
Since the influence of the wire bending tendency is eliminated by the present invention, the reproducibility of welding work such as robot welding is remarkably increased, and the occurrence of welding defects due to bead meandering is significantly reduced. Figure 1
In the embodiment, the triangular cross section is formed by the combination of the V groove and the flat surface, but FIG. 8 is a sectional view of the ceramic guide portion of another embodiment. In the V groove of the V groove member 26, the convex portion of the pressing member 27 is formed. The same function can be achieved even with the cross section of the intruding shape. The V groove in this case has an equilateral triangular shape with a depth of 1.7D to 3D, where D is the wire diameter. FIG. 9 is a sectional view of a ceramic guide portion according to still another embodiment.
This is also the case when the pressing member 29 is also a V groove having a right angle.

Although the V-grooves are used in the above embodiments, the present invention is not limited to the V-grooves, and similar functions can be achieved even if other cross-sectional shapes such as U-grooves close to the V-grooves. The case is also included.

[0026]

According to the present invention, since the three sides of a triangle formed by a concave groove typified by a V groove and one plane are pressed so as to be in close contact with the outer circumference of the wire, the diameter is larger than the conventional wire diameter. Compared to the case of using a triangular hole ceramic tip that was manufactured to have an inscribed circle, the wire is straightened and delivered, the wire insertion position is stable, and the welding work is more stable. There is.

Further, in the case of the triangular hole tip, one tip can be applied only to one nominal wire diameter, but according to the wire guide of the present invention, the nominal wire diameter range applicable to one set of wire guides. Spreads.

Further, according to the present invention, the ceramic member having the concave groove can be molded by simply cutting the green body or by a simple mold which can be manufactured at low cost. Further, since the pressing member may have a flat plate shape, it is easy to manufacture. The manufacturing tolerance range required for these members is considerably larger than that of the conventional triangular hole ceramic chip, and the manufacturing yield is greatly improved.

Further, according to the present invention, the notch has only one concave groove portion, which is also improved in heat resistance and impact resistance as compared with the case of the conventional triangular hole ceramic chip.

Further, since foreign matters such as plating scraps are discharged from the gap formed between the pressing member and the concave groove member,
Even when compared to the triangular hole tip, the wire is less likely to be clogged, so the wire is not clogged at all.

[Brief description of drawings]

FIG. 1 is a structural diagram of an embodiment of a wire torch to which a wire guide according to the present invention is applied.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a sectional view taken along line CC of FIG.

5 is a sectional view taken along line DD of FIG.

FIG. 6 is a EE view of FIG. 1.

7 is a cross-sectional view taken along line FF in FIG.

FIG. 8 is a structural view of another embodiment of the wire guide according to the present invention.

FIG. 9 is a structural view of still another embodiment of the wire guide according to the present invention.

FIG. 10 is an explanatory diagram of a configuration of a conventional hot wire TIG welding apparatus.

FIG. 11 is a cross-sectional view of a conventional triangular hole guide chip.

[Explanation of symbols]

 6 wire 19,26,28 V groove member (ceramic guide member) 20 V groove (concave groove) 25,27,29 pressing member (ceramic member)

Claims (3)

[Claims] 1. In a welding torch for guiding a wire to a welded portion, a heat-resistant and abrasion-resistant ceramic guide member having a groove for guiding a wire that is being electrically heated, and a wire extending along the groove. A welding torch, comprising: a ceramic member that presses a wire into a groove so as to be fed. 2. The wire conducting chip according to claim 1, wherein a wire energizing tip is arranged on a wire inlet side of the ceramic member that presses the wire into the concave groove, and the chip presses the wire against the concave groove ceramic member to conduct electric contact. Welding torch to do. 3. The welding torch according to claim 1, wherein the concave groove is a V groove.