JPH0337467B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a consumable electrode wire for arc welding, and in particular, in automatic welding in which a welding wire wound into a coil is unwound and continuously fed by a feed roller, the arc point swings. This reduces fluctuations in wire feeding speed and wire feeding speed, and reduces the feeling of torch resistance during wire feeding in semi-automatic welding, allowing stable welding to be performed. Types of welding operations performed using wire include automatic welding, which is performed using a traveling truck or robot, and semi-automatic welding, which is performed manually.
In either type of welding, the welding wire as a consumable electrode is wound into a coil and then unwound one after another by a wire feeding roller.
It passes through the conduit tube and the current-carrying chip hole, and is fed from the tip of the chip to a predetermined position of the welding part. There are many ways to wind the coil of this welding wire, such as aligned winding, twill winding, random winding, etc., and the coil winding shapes include coil winding, rim winding, spool winding, etc.
Alternatively, there is a drum winding method. By the way, the various coil-wound welding wires described above leave curls in the unwound state, and the degree of curling varies depending on the position of the wire.
As shown in the figure, the orientation direction of the wire 2 led out from the current-carrying tip 1 changes, and the deflection r of the wire changes as welding progresses. The sharper the change in the degree of winding of the wire, the more rapid the variation in runout r, and the arc point often deviates from a predetermined position on the weld line. Furthermore, the wire inside the conduit tube becomes slightly distorted depending on the degree of curl, so that the wire feeding speed also changes over time. Changes in wire feeding speed cause fluctuations in the arc point and impair arc stability. Furthermore, in semi-automatic welding, as the wire feeding resistance fluctuates, the hand of the worker holding the welding torch feels "lumpy" and resistant, which significantly impairs welding workability. The degree of curl in the welding wire depends on the tensile strength of the wire, the rolling force of the wire feed roller, etc., so the degree of curl can be adjusted by appropriately adjusting the rolling force of the roller. Although it is not theoretically impossible to make the runout r constant, in practice such control requires extremely complicated operations and cannot be said to be a practical method at all. The present invention has been made in view of the above-mentioned circumstances, and is aimed at freeing the cast diameter of any two adjacent wire rings of a spool-wound welding wire wound in multiple layers into a coil shape, that is, the wire from the restriction of the coil shape. The difference in diameter between adjacent arcuate wire rings in the free state is approximately 10 mm or less, and the difference between the maximum cast diameter and minimum cast diameter of the wire rings over the entire length of the wire is 40 mm or less, and at least the outermost layer provides a welding wire made of a wire ring having a cast diameter larger than the flange diameter of the spool. The cast diameter of ordinary spool-wound wire varies depending on each wire ring, and generally increases from the beginning of winding to the end of winding, as shown by curve A in FIG. In addition, in order to prevent the coil from coming apart during use, the wire is sometimes pressed with a pressing roller or the like near the end of the winding to reduce the cast diameter at the end of the winding as shown in curve B. In this case, the cast diameter of at least the outermost layer is usually equal to or larger than the flange diameter of the spool. The greater the difference in the cast diameters of the respective wire rings, the more pronounced the above-mentioned disadvantages due to curling become. With conventional wires, the difference in cast diameter between two adjacent wire rings is usually about 15 to 50 mm, which impairs welding stability. According to experiments conducted by the present inventors, by adjusting the difference in the cast diameters of arbitrary adjacent wire rings to about 10 mm or less, there is almost no fluctuation in wire runout r or fluctuation in the arc point, and the feeding speed is It was also confirmed that the unpleasant feeling of feeding resistance in semi-automatic welding can be significantly alleviated. Note that the diameter of the wire cast in the present invention refers to the diameter of the cut wire 1 as shown in FIG.
This refers to the average value of the maximum value D and minimum value d of the diameter in a free state when the winding is placed on a flat surface. FIG. 4 shows an example of a wire rewinding device. In the figure, the wire 2 is passed from the bobbin 3 to the straightener 4 to the curling roller 5 (the figure shows a three-point curling roller consisting of three rollers). (for example)], the winding device 6 is configured to wind the winding machine 6. A conventional winding method will be explained with reference to FIG.
The wire supplied from the bobbin 3 is adjusted by a straightener 4 to adjust the bending of the wire and the flatness of the wire (the vertical distance between adjacent turns when one turn of the wire is placed on a flat surface) in order to improve the wire characteristics. Then, the cast adjustment at the beginning of coil winding is performed by the left and right adjustment rollers and rollers of the three-point curling roller 5, and the wire is wound by a predetermined amount in this state. In this way, wire cast adjustment is generally performed only at the beginning of coil winding, and even if the winding weight of the winder increases, the winding remains as it is, so the curling roller The entrance angle (θ) between the wire 2 passing through the apex B of the coil winding of the winding machine 6 from the fulcrum A of the winding machine 5 and the horizontal plane gradually becomes smaller as the winding amount increases. For example, when winding a 20 kg spool and the entry angle at the beginning of winding is 64.5 degrees, after winding 20 kg of aligned winding, approximately
It becomes 73.5 degrees, and the entrance angle (θ) becomes smaller by about 9 degrees. This results in a significant change in the cast at the beginning of winding and the cast at the end of winding. This difference increases as the weight of the coil winding increases. In addition, when winding in alignment, the number of winding layers is 1.2φ at the left and right ends of the coil where the number of winding layers increases by one layer, especially from the first layer to the second layer and from the second layer to the third layer of the coil winding. For a wire with a wire diameter of 270 mm, when the distance from fulcrum A to fulcrum B is 270 mm, and the height of A and B is 130 mm, the entry angle in the first layer is 64.3 degrees, and when moving to the second layer, The height H is 128.96 mm (130-√3 x 1/2 x 1.2), which is 64.47 degrees, which is 0.17 degrees smaller. For this reason, changes in cast occur, especially for two adjacent wheels of each layer number. This means that as the diameter of the wire becomes thicker, the degree to which the wire entrance angle decreases becomes larger, and the change in cast also becomes larger. Therefore, the difference in cast diameter between two adjacent wire rings ranges from 15 to 50 mm. Thus, the difference in cast diameter between two adjacent wire wheels is approximately 10 mm.
By doing the following, the wire can be fed smoothly, and even if the distance from the coil spool to the arc point is short, stable welding can be performed without sudden fluctuations in the arc point. By the way, if the adjustment operation to reduce the difference in the cast diameter of each wire ring is performed over the entire length of the coil, it becomes possible to stabilize the wire feeding from the beginning of winding to the end of winding of the coil. . However, as shown in FIG. 2, the diameter of the coil cast by a conventional general winding device ranges from about 100 to 150 mm between the beginning and the end of winding. The fluctuation range of the arc point gradually increases, and the arc point may eventually deviate from the welding line. Therefore, by keeping this wire entry angle (θ) at a constant value from the beginning of winding to the end of winding of the coil, it is possible to reduce the change in cast diameter, and in particular, to maintain the maximum cast diameter throughout the entire length of the coil. It has been found that the above-mentioned disadvantages can be overcome by setting the minimum cast diameter difference between the wire and the wire to about 40 mm or less. FIG. 5 shows a specific example of a three-point curling roller section for keeping the line entrance angle (θ) constant. The curling rollers each have a shape corresponding to an increase in the coil diameter (increase from the diameter shown in the experiment to the diameter shown by the broken line) due to an increase in the winding weight of the winder 6 (increase in the number of winding layers). Since it is configured to sequentially move upward in parallel (ascends from the position shown by the solid line to the position shown by the broken line), the wire entry angle (θ) is always kept constant from the beginning of winding to the end of winding. In this operation, the entire curling roller is electrically interlocked with the traverse mechanism of the winder 6, and each time the wire of the winder traverses, the entire roller is raised by one layer of coil winding using a motor. All you have to do is let it happen. Alternatively, the length of the wire for one layer to be wound into a coil may be determined in advance, and the entire roller may be raised every time the coiled length reaches a certain amount. Alternatively, it is also possible to configure the winder 6 to move downward in parallel each time the number of layers wound by the winder 6 increases while the position of the curling roller remains fixed. By winding the wire under conditions where the wire entry angle (θ) is always kept constant, the difference in cast diameter of each wire from the beginning to the end of the wire is approximately 40
mm or less, and at the same time, the difference in cast diameter between two adjacent wire wheels is reduced, resulting in significant improvements in arc stability and feeding resistance. Note that there is no particular limit to the value of the wire entrance angle (θ), and it may be a value commonly used in normal winding operations, for example, about 50 to 70 degrees. Table 1 shows conventional coil-wound welding wire and 3
As the winding weight increases, the entire dot-type curling roller is raised upwards by a certain amount using a pulse motor, and the wire entry angle (θ) is set to 64.5 degrees. Regarding the wire of the present invention, in which the difference in cast diameter between rings was adjusted to 10 mm or less, and the difference between the maximum and minimum cast diameters of the entire wire was adjusted to 40 mm or less, the cast diameter and the tip of the welding machine tip An example of the results of 200 consecutive measurements of wire runout r from . The test wires were all spool-wound coils with a wire diameter of 1.2 mm and a weight of 20 kg. "Cast diameter"
Column (a) shows the difference in cast diameter between two arbitrary adjacent wire rings (however, the number of measurements in one coil is n = 5), and column (b) shows the cast diameter variation range from the beginning of winding to the end of winding. [Maximum cast diameter to minimum cast diameter] (The numbers in the box at the bottom are the difference between the maximum cast diameter and the minimum cast diameter).
The "middle layer" and "lower layer" columns show the fluctuation range of the wire runout r at the "start of winding", "middle", and "end of winding" of the coil (the value in the lower bracket is the average value), and the "maximum width", respectively. represents the maximum value of left and right swing width around the weld line from the beginning of winding to the end of winding of one coil. To measure the wire deflection, use a curved torch to guide the wire out of the tip hole, and measure the distance (l) from the tip of the tip.
This was done by measuring the value of the deviation r from the welding center at a position of 160 mm (see Figure 1).

[Table] As shown in Table 1, conventional wire No. 1~
6 and wire Nos. 7 to 12 of the present invention, with the conventional wire, the difference in cast diameter between the two wires exceeds 10 mm,
Furthermore, the difference between the maximum cast diameter and the minimum cast diameter is approximately 100 mm even for No. 1 wire, which has the smallest fluctuation value, whereas wires No. 7 to 12 of the present invention each have a difference of approximately 100 mm.
The difference in cast diameter for the wire wheels is less than 10mm, and the difference between the maximum and minimum cast diameters is less than 40mm, even for No. 8, which is the largest. Comparing this in terms of the wire runout r, with conventional wires, the runout r increases as you move from the lower layer of the coil to the upper layer, and the swing width exceeds about 40 mm as shown in the "Maximum Width" column. It can be seen that in the wire of the present invention, each layer exhibits a substantially constant value, and the amplitude of the entire coil remains stable at approximately 20 mm or less. In addition, in actual welding work, by using the wire of the present invention, fluctuations in the arc point are reduced, there is almost no sense of torch resistance, and the bead appearance is uniform and beautiful, resulting in improved welding workability and welding quality. It has also been confirmed that it is significantly superior to conventional wire in terms of both aspects.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the runout of the wire, Fig. 2 is a graph showing changes in the cast diameter of the coil-wound wire, Fig. 3 is an explanatory diagram showing the wire ring of the coil-wound wire, and Fig. 4
The figure is an explanatory diagram illustrating a wire winding device, and FIG. 5 is an explanatory diagram of a curling roller for adjusting the coil entrance angle (θ). The main symbols in the drawings are as follows. 1...
energizing chip, 2... welding wire, 4... straightening machine, 5... curling roller, 6... winding machine.

Claims (1)

[Claims] 1 Spool-wound welding wire wound in multiple layers into a coil, where the difference in cast diameter between any two adjacent wire rings is 10 mm or less, and the maximum cast diameter and minimum cast diameter of the wire rings over the entire length of the wire. A welding wire characterized in that the difference between the two is 40 mm or less, and at least the outermost layer is made of a wire ring having a cast diameter equal to or larger than the flange diameter of the spool.