JPH0364227B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for winding a welding wire such as a twisted solid wire, a flux wire, particularly a seamed wire with seams welded together, or a seamless wire without a seam in a loop shape in a pale pack. This invention relates to a load of welding wire stored in a stack.

A pail pack with a cylindrical structure having an inner tube and an outer tube or only an outer tube is generally used as a large-capacity welding wire storage container.
Because the wire is twisted 360° during winding, the wire coming out of the welding torch rotates around the torch axis, causing the weld bead to meander. Therefore, when loading the welding wire into the pail pack, make sure that the wire is within its elastic limit. A method has been put into practical use in which the wire is loaded with a 360° reverse twist per turn, which offsets the twist experienced when unloading, thereby eliminating the wobbling of the wire coming out of the welding torch.

However, when the conventional twisted welding wire is taken out of the pail pack, the shape of the wire is substantially straight, and the wire with this straightness is fed and brought into contact with the contact tip of the welding torch. When the wire is energized, as shown in FIG. 1, since the wire through hole 2 of the contact chip 1 is straight and the wire 3 is also substantially straight, the contact between the inner surface of the wire through hole and the wire is insufficient and the energization does not occur. It becomes defective, the arc becomes unstable, and in severe cases, sparks may be generated within the through hole, causing welding and stopping the wire feeding.

The present invention solves the problems of the prior art described above, and the gist thereof is to provide a welding wire charge in which twisted welding wires are stacked and stored in a loop shape in a pail pack.
The welding wire has a plastic bend in the range of 250 mm to 2500 mm in diameter with respect to the straight wire through hole of the contact tip, and further provides a reverse twist within the elastic limit to offset the twist received during removal. This is due to the fact that it is being loaded.

The bend in the present invention refers to the plastic expansion of the wire in its open, natural state. In other words, when you grab several loops of wire stored in the pail pack, take them out of the pail pack, and open them on a flat surface, the few loops of wire that were released will bend according to the plastic bending inherent in the wire itself. The diameter of the new loop is called the curve.
This plastic bending of the wire can be achieved by using appropriate mechanical means, such as a commonly used bending mechanism consisting of a plurality of rollers, or by winding the wire several times around a rotating shaft with a predetermined diameter. good. The diameter is regulated within the above range.
The loading material of the present invention is a welding wire with a diameter
It is obtained by giving the wire a plastic bend of 250 mm to 2500 mm, giving the wire a reverse twist within the elastic limit, and loading it into a pail pack.

Since the plastically curved wire is loaded into the pail pack with stress within the elastic limit, the wire pulled out from the pail pack when used for welding sufficiently retains this curve. Therefore, even if the wire through hole 2 of the contact chip 1 is straight as shown in FIG.
Since the wire 4 is curved, the wire always makes sufficient contact with the inner surface of the wire through hole of the contact chip 1, and stable welding can be performed without causing conduction failure. Furthermore, since the advantage of the twisted wire that the weld bead does not meander is naturally maintained, the wire coming out from the contact tip does not sway, and good welding can be performed without meandering of the weld bead.

Next, the reason for limiting the upper and lower limits of the curve of the present invention will be explained. First, the upper limit value (2500 mm) is related to the stability of the arc during welding. In other words, the twist
If it exceeds 2500 mm, the wire becomes substantially straight, so the contact between the contact chip and the inner surface of the wire through hole becomes insufficient, and the arc becomes unstable. Next is the lower limit value (250 mm), which is related to the wire feedability. In other words, if the bend is less than 250 mm, the contact resistance between the wire and the inner surface of the conduit tube that guides the wire from the pail pack to the contact chip will be large, and the wire will receive a large resistance when passing through the conduit tube, causing the wire to The feed becomes unstable, and as a result, the arc becomes unstable.

Twisted wires with various bends were manufactured, welded fully automatically, and the relationship between arc stability and bends was determined, and the results shown in Figure 3 were obtained.
In other words, when a bead with a length of 700 mm is placed, the welding voltage is
The welding current was measured, and if the arc condition became partially stable, the product was judged to be rejected, and the defective rate when 100 beads were placed was shown. From this experimental result, the bend is 250mm.
In the range of ~2500 mm, the defective rate is 5% or less, and stable welding can be performed in practice.

FIG. 4 shows the fluctuations in welding current and welding voltage when welding was performed using the wire of the present invention and FIG. 5 using the wire of the comparative example. Both the invention wire and the comparative example wire are 1.2
A solid wire with a diameter of mm was used, and its bend was 1000 mm for the wire of the present invention and 3500 mm for the comparative example wire, and CO ₂ gas shield arc welding was performed under the following conditions.

Welding voltage: 27V Welding current: 200A Welding speed: 65cm/min Wire protrusion length: 20mm CO ₂ flow rate: 20/min As is clear from the figure, with the wire of the present invention, both welding current and welding voltage are stable, and good welding with a stable arc can be performed. was completed. In the comparative example wire, both welding current and welding voltage were unstable.
The arc condition was unstable.

Next, a specific example of the loading device for obtaining the loaded material of the present invention will be described in accordance with the sixth example. This loading device consists of a mechanism that supplies welding wire, a mechanism that gives the welding wire a plastic bend, and a mechanism that twists the welding wire to form a loop and drops the welding wire into the pail pack. configured. Welding wire 4 sent from a wire supply source (not shown) is given a predetermined bend by a bend adding mechanism 5 consisting of a plurality of rollers, and a wire supply mechanism consisting of a wire take-up capstan 6 and a presser roller 7. and inserted from the inlet 10 of the rotary fryer 8 forming the fryer mechanism,
It is loaded into the pail pack 9 through its rotating outlet 11. The upper end of the wire is connected to the wire feeding mechanism 6, 7.
Furthermore, since the lower end is fixed to the upper end surface of the wire stack W in the pail pack, the wire is twisted by 2π (360°) per rotation of the flyer.
Needless to say, the wire undergoes only deformation within its elastic limit in the processes after the bending mechanism 5, and each device is configured in this manner. Therefore, the welding wire is housed in the pail pack with only a predetermined plastic bend.

As described above, according to the present invention, the weld bead does not meander and travels in a straight line during welding, and the instability of the arc state, which had been a problem in the past, has been solved, and welding with good current conductivity and stable arc state can be achieved. can be carried out, and its practical value is great. Even if the bend is added when the wire is removed from the pail pack and sent to the welding torch,
Although contact between the wire and the contact tip is ensured, this requires a wire bending mechanism to be attached to the pail pack, which lacks versatility and increases feeding resistance when bending the wire, making it difficult to maintain a stable arc condition. If the wire is stored in a pail pack with a bent wire that would impede maintenance, the pail pack can be handled in the same way as before (there is no need to provide a bending mechanism in the pail pack), and the wire This provides the advantage of good contact with the contact chip and therefore good conductivity.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a contact state between a conventional twisted welding wire and a contact tip, and FIG. 2 is a schematic diagram showing a contact state between a twisted welding wire and a contact tip provided with curls according to the present invention. Figure 3 shows the upper limit of numerical values in the present invention,
Diagram 4 showing the defective rate to explain the lower limit value
Figures 5 and 5 are diagrams showing welding voltage and welding current fluctuations when the present invention wire and comparative example wire are subjected to welding, respectively, and Figure 6 shows an example of a loading device for obtaining the charge of the present invention. It is a schematic diagram. 1: contact tip, 3, 4: welding wire, 5: bending groove adding device, 6: wire take-up cab stan, 8: rotary flyer, 9: pail pack.

Claims (1)

[Claims] 1. In a welding wire load in which twisted welding wires are stacked and stored in a loop shape in a pail pack, the welding wire has a diameter of 250 mm to 2500 mm relative to the straight wire through hole of the contact tip.
1. A welding wire charge, characterized in that it has a plastic bend in the range of mm, and is loaded with an opposite twist within the elastic limit to offset the twist received during removal.