JPH05185232A - Wire for welding incorporated in pail-pack - Google Patents

Abstract

PURPOSE:To prevent the meandering of welding bead caused by the swing of a wire, because the swing of the welding wire incorporated in a pail-pack paid out of the torch at the time of welding is large in comparison with a reel winding wire. CONSTITUTION:In the welding wire incorporated in the pail-pack, the cross section of the wire has the shape of ellipse or in similar to ellipse, and further, this shape is in the range of 0.002<=(a-b)/the nominal wire diameter <=0.006 at the time of using (a) for the major axis and (b) for the minor axis and further, the directional change of the major axis (a) in the wire at the time of paying out from the pale-pack is within 60 deg. angle per 3m of the wire length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic welding wire, and more particularly to a large capacity welding wire loaded in a pail pack or the like.

[0002]

2. Description of the Related Art In recent years, as represented by the widespread use of welding robots, automation of welding, labor saving and unmanned welding have been further promoted. The welding wire in this case is, for example, 100
A wire in a winding form called a pail pack, which is loaded in a unit weight of kg or more, is used. Compared with the conventional 10 kg unit winding, this large weight unit loading wire can reduce the number of times required for wire replacement and enables continuous welding for a long time, so it is expected that the application will be expanded further in the future.

The performance of the wire required in an automated use condition environment such as such a welding robot is the target property of welding, that is, the target position of the wire is stable and high-precision welding can be maintained. It is indispensable to be able to always reproduce accurately and continuously with respect to the initial setting of the wire aiming at. In order to improve the accuracy and stability of aiming the wire, usually, there are four methods in which the wire is loaded in a straight line without bending the wire. However, the wire loaded in the pail pack is often used by being placed at a position that is far from the welding member. Therefore, the wire is sometimes used through a long conduit cable that exceeds 6 m, and during this time, it passes through a number of curved sections with different directions, so the wire when it reaches the tip of the tip due to the small bends imparted by this curved section Produces various swells with different directions and curvatures. Since this undulation hinders the stability of the wire aiming at the time of welding, the wire is required to have a performance that is difficult to bend.

As a countermeasure against this, a method of increasing the rigidity of the wire is generally adopted and effective. However, although the linearity of the wire is improved by increasing the rigidity of the wire, the contact point between the feeding tip of the welding torch and the wire becomes unstable, and the electric conductivity tends to become unstable. As another means, for example, the aim is to improve the feedability of the welding wire. However, as disclosed in JP-A-51-105949 or JP-A-55-147497, the wire cross-sectional shape is changed. Although it was considered to make it a variant,
The commonly used welding tip cannot be used because it has a true cylindrical shape, and it is a special product that is specially adapted to the wire cross-sectional shape, which is a cost problem.

As described above, although various technical proposals have been made, there is still a demand for solving the problems in the continuous automatic welding as described above. This is due to the rapid increase in higher current and higher precision with the progress of welding robots.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems of the wire containing the pail pack and to stably maintain the targetability of the wire coming out of the welding torch. Especially, it is an object of the customer of welding wire to realize this by improving the characteristic of the wire itself without taking any special new means.

[0007]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and in a large-capacity wire loaded in a pail pack, the wire cross section has an elliptical shape or a shape similar to an elliptical shape. Is 0.002 ≦ (ab) / nominal wire diameter ≦ 0.0 as an ellipse with major axis a and minor axis b.
The wire for welding with a pail pack is characterized in that it is in the range of 06 and the direction change of the major axis a in the wire when pulled out from the pail pack is within 60 degrees per 3 m of the wire length.

[0008]

The reason why the automatic welding wire loaded in the pail pack according to the present invention has the above-mentioned structure will be described in detail below. As a result of various studies on the targetability of the welding wire, the present inventor has found that the targetability of the wire wound on the spool is much better than that of the wire loaded in the pail pack. The reason is that the winding of the wire wound on the spool is in one direction. In contrast, the peculiarities of the wire loaded in the pail pack have no particular orientation, so when used over a long conduit cable, it is imparted at this bend while passing through different bends with multiple directions. This is because a small bend causes the wire to reach various ridges having different directions and curvatures when reaching the tip of the chip.

It is possible to intentionally give a unidirectional winding behavior similar to spool winding to a wire containing a pail pack, but this is difficult. That is, when the wire is pulled out from the pail pack during welding, 360 turns per turn.
Since the wire is twisted to a certain degree, the wire pack is filled in advance while giving the wire a reverse twist to cancel the twist. For this reason, it is difficult to load the wire into the pail pack while maintaining the state of being wound in a certain direction. As described above, the wire with the pail pack has a special problem in securing the target property.

As a result of various studies, a slightly elliptical cross-sectional shape of the wire was used to make the wire exit direction constant even when the wire packed in the pail pack was used in a curved torch or a straight torch. He identified what he could do. In other words, bending the wire cross section in the direction of the minor axis does not require a large force, so even when used through a long conduit cable, the wire always bends in the direction of the minor axis, so when the wire comes out of the welding torch. , Because it always bends in a certain direction.

Next, the cross-sectional shape of the wire has a major axis a and a minor axis b.
Of 0.002 ≦ (ab) / nominal wire diameter ≦ 0.
The reason why it is limited to 006 will be described. (Ab) / Nominal wire diameter <0.002, the ellipse of the wire cross section becomes almost the same as a circle, and when loaded in the pail pack, the direction of the wire is not fixed and the welded bead meanders. Cause defects such as.

On the other hand, in the case of 0.006 <(ab) / nominal wire diameter, when the wire cross-sectional shape becomes an ellipse and it is loaded into a pail pack and welded, the wire directionality is good and the targetability is excellent. ing. However, since the degree of deformation is large, it cannot be used with a general welding tip, and there is a drawback that a welding tip adapted to a special wire shape is required and the cost becomes high.

By the way, in order to obtain good targetability, the cross section does not necessarily have to be a perfect elliptical shape, and for example, an oval shape or a shape obtained by unilaterally compressing a perfect circle may be used. I found it good. Therefore, the wire of the present invention may have an elliptical shape in a broad sense including the above shapes.

Next, the direction of the major axis a of the wire is the wire length 3
The reason for limiting the change within 60 degrees with respect to m will be described. When the wire comes out of the welding tip through the feeder and conduit cable from the pail pack, the wire tends to bend in the minor axis direction, so naturally the bending direction of the curved torch and the minor axis direction of the wire are on the same plane. . Also, even when not using a curved torch,
The final curved portion of the conduit cable and the minor axis direction of the wire are on the same plane.

However, when the major axis direction of the wire changes by more than 60 degrees per 3 m of wire length, the minor axis direction of the wire and the curved curved torch or the final curved portion of the conduit cable tend to be kept on the same plane. Remains in the welding torch or conduit cable. As welding is carried out, the torsional stress of the wire increases as the wire is supplied, and at some point the wire reverses at the exit of the welding tip, causing the arc position to change instantaneously and develop into a bead meandering.

On the other hand, when the change in the major axis direction of the wire is 60 degrees or less per 3 m of the wire length, the residual torsional stress is so small that there is no change such as reversal of the wire and no bead meandering develops. It was

As a method of measuring the major axis direction of the wire, the following measuring method was used. That is, as shown in FIG. 1, the wire W is taken out from the pail pack in a length of 3 m so as not to be bent, and placed on a plane in a natural state for about 20 minutes.
The wire diameter was measured for each cm, and the wire major axis direction was determined in units of 10 degrees. Wa is a cross-sectional view of the wire at each position (the degree of the ellipse is extremely exaggerated). , Θ is the measurement position θ
If there is no change in ₁ , θ ₂ , ..., There is no change in the direction of the wire length a. The difference between the two values of θ that differed most in the wire major axis direction from the measurement results at each position of θ was defined as the change in the wire direction per 3 m of the wire.

As a means for controlling the direction change of the wire major axis a, the wire loaded in the pail pack is twisted as described above. If the twist given to the wire and the twist caused when it is pulled out from the pail pack at the time of welding just cancel each other out, it is usually possible to keep the major axis direction of the wire constant before entering the wire filling device into the pail pack. Is not enough.

FIG. 2 is a principle view of a wire loading device for a pail pack. The wire W is fed into the pail pack 1 by the feeding roll 11, and the guide pipe 12 is rotated 13 so that the wire W is loaded while being twisted. Reference numeral 14 denotes a support tube for guiding the wire, which is non-rotatably supported by a device not shown. A projecting member 15 is attached to the support cylinder 14 to fill the pail pack with the wire eccentric. Then, by slowly rotating 17 the turntable 16 on which the pail pack is placed, the eccentric direction is slightly shifted, so that the wires can be stacked by being crossed and prevented from being entangled.

As described above, the guide pipe 12 is twisted by 360 degrees per revolution, but since the pail pack is rotated by the turntable 16, the twist occurs. Generally, the turntable is rotated in the direction opposite to the guide pipe, and the twist becomes, for example, 240 to 270 degrees, and the insufficient amount of twist from 360 degrees becomes 90 to 120 degrees per turn. In the case of a pail pack containing 200 kg, the length of one turn is about 1.4 m. Therefore, when the wire length is 3 m, when the wire is pulled out during welding, the twist of 190 to 260 degrees occurs due to the above shortage.

Therefore, in this case, another means is required to keep the direction change of the major axis a within the range of 60 degrees per 3 m of wire length, which is the condition of the present invention. In order to make the cross section elliptical, wire drawing is performed using, for example, a die having an elliptical hole. At this time, if the wire is drawn while rotating the die, the direction with respect to the wire cross section of the major axis a can be changed. By such means, the major axis direction of the ellipse of the wire cross section can be controlled so as to satisfy the conditions of the present invention.

The effect of the present invention was also able to realize the improvement of the target property in the case of the flux-cored wire. The flux-cored wire according to the present invention is not affected by the type of flux to be filled inside, and can be applied regardless of its use. Also, as the outer skin material of the wire, not only general mild steel but also low alloy steel to high alloy steel can be freely selected according to the application.

[0023]

EXAMPLES Next, the effects of the present invention will be described more specifically with reference to examples. As shown in FIG. 3, the pail pack 1 and the wire feeder 3 are connected by a conduit cable 2 of 3 m, and further, as shown in FIG. ) And the loop direction is changed by 90 degrees and the diameter is 300m.
A loop 5b (1 turn) of m was formed and three curves 5c having a radius of 100 mm were formed near the tip, and a curved torch 6 was attached to the tip. Send each test wire loaded in the pail pack 1 into the conduit cable,
Whether the target property is good or bad was judged based on the magnitude of the deflection 1 of the wire tip when the wire W was projected 150 mm from the tip of the welding tip 7.

[0024]

[Table 1]

The run-out of the tip of the wire is such that 200 wires are continuously fed, and an average value Xbar of l from the average pointing point P 150 mm apart to each pointing point is expressed, and in Table 1, Xb
The ar having a value of 2 mm or less is shown as a circle, the Xbar having a value of 2 to 5 mm as a triangle, and the Xbar having a value of 5 mm or more as a cross. The wire feedability is evaluated by the feed resistance value related to the feed roll being 4 kg.
The following were judged to be good (circle) and those exceeding 4 kg were judged to be bad (x), and shown in Table 1 respectively.

The wires used in the examples are represented by the cross-sectional major axis a and minor axis b of the wire (ab) / the nominal wire diameter is different, and a large number of solids are obtained by varying the major axis direction of the wire. A wire and a flux-cored wire were manufactured, and the target property as a product wire was investigated for each. The result is (ab) / value of nominal wire diameter, wire 3
The change in the direction of the major axis a per m (change in wire angle) and the nominal wire diameter are collectively shown in Table 1.

As is clear from Table 1, those having a value of (ab) / nominal wire diameter of less than 0.002 are generally inferior in targetability. On the other hand, if it exceeds 0.006, the feeding performance is poor with a commercially available true-cylindrical chip, but 0.002-
When the wire diameter was within the proper range of 0.006 and the direction of the wire major axis a was within 60 degrees with respect to the wire cross section, both the feeding property and the target property were excellent.

[0028]

EFFECTS OF THE INVENTION The present invention is constructed as described above, but in a large capacity wire loaded in a pail pack, the major axis and minor axis of the cross-sectional shape of the wire are set in a specific range and the direction of major axis is changed. By limiting, even if a commercially available true-cylindrical welding tip was used, a welding wire having good feedability and good targetability could be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a change in the direction of a major axis a of a wire cross section.

FIG. 2 is a principle diagram of a wire loading device for a pail pack.

FIG. 3 is a diagram showing a wire targeting property and a wire feeding property test method.

Claims (1)

[Claims] 1. A large-capacity wire loaded in a pail pack has a wire cross section of an ellipse or a shape similar to an ellipse, and this shape is 0.002 ≦ (a) as an ellipse with a major axis a and a minor axis b. -B) / nominal wire diameter ≤ 0.006
And a change in the major axis a of the wire when pulled out from the pail pack is within 60 degrees per 3 m of the wire length.