JPH0691385A - Butt welding method for extremely fine wire - Google Patents

Abstract

PURPOSE:To enable the endless drawing of extremely fine wires by specifying the deviation in the wire diameter in the weld zone at the ends of the extremely fine wires and the bending angle of the other wire to the one wire to specific values at the time of butting the ends of the wires and welding these ends by irradiation with a laser, thereby executing exact welding. CONSTITUTION:The fine wires 1, 2 subjected to a patenting treatment after drawing and to a surface treatment with Ni, etc., at need are fixed by butting the ends of the fine wires to be joined by using a retaining jig 7 made of glass and the butt parts are irradiated with the laser 4 and are thereby welded. The weld zone is formed to have the straightness of <=6mm deviation in the wire diameter in the weld zone and <=10 deg. bending angle of the other wire to the one wire. As a result, the need for a wire passing operation is eliminated and the straightness is extremely good. In addition, the exact welding is possible and the drawn rods are made continuous with each other with high accuracy. The endless drawing of the extremely fine wire is thus possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butt welding method for superfine wires having excellent straightness, which enables endless wiredrawing by joining between wiredrawing rods when drawing metal into ultrafine wires. It is a thing.

[0002]

2. Description of the Related Art In order to continuously draw a thin metal wire, it is necessary to join the wires between the rods. But it is possible to butt-weld even a fine wire with a relatively large diameter, that is, with a diameter of about 150 μm, but if the diameter of the wire is as small as 50 μm or less, it becomes difficult to butt and it is difficult to weld accurately, and bending, constriction or protrusion occurs. If the wire is passed through with a defective shape such as a portion formed, the wire will be broken, and it will be necessary to pass the wire through the die again. Therefore, extremely advanced technology is required. Further, when further drawing a fine wire having such a small wire diameter, it is usual to perform a patenting treatment in a lead bath or an inert gas, or a surface treatment such as Ni plating before the drawing. , These treatments are usually performed simultaneously for a large number of wires, and are divided at the time of wire drawing in consideration of the treatment efficiency, and the wire weight is optimized up to about 1 kg (for example, 62 km at 50 μmφ), and if it is more than that, the treatment efficiency is increased. Is significantly deteriorated.

In other words, due to such processing restrictions, an extra fine wire having a relatively short length is manually passed through the drawn wire each time. However, the ultra fine drawn wire has many ultra fine wires. It is composed of small-diameter surface-reducing dies, and it takes a considerable amount of skill and time to pass the ultra-fine wire through each die, and the productivity is extremely hindered.

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems in the present situation. When continuously drawing an ultrafine wire, the ultrafine wire is formed by a laser while maintaining its straightness. An object of the present invention is to provide a butt welding method for ultra-fine wires, which has extremely high productivity by performing minute spot welding.

[0005]

SUMMARY OF THE INVENTION The present invention for achieving the above object is a butt welding method for continuously drawing an ultrafine wire, which comprises a patenting treatment after drawing and, if necessary, a Ni coating. A thin wire that has been surface treated such as is fixed by abutting the ends of the thin wires to be joined using a holding jig, and laser welding is applied to the abutted portion to cause a wire diameter deviation (a) at this welded portion. It has a straightness of 6 μm or less and a bending angle (θ) of one line with respect to the other line of 10 ° or less.

The method of the present invention will be described in detail below. Usually, butt welding is a method in which materials to be welded are strongly butted to each other and an electric current is caused to flow through this portion to generate resistance heat, and upset welding is performed. It is also used for thin wire welding, and it is said that welding up to about 100 μm is possible. In such an ultrafine wire, when the butt strength is given, the wire is bent at the waist and accurate butting is difficult, and even if welding is possible, desired straightness cannot be obtained at the welded portion. That is, although the illustration of straightness in the welding unit 1, one of the hairline w ₁
And the bending angle θ formed by the other thin line w ₂ becomes large,
If the wire diameter deviation a between the ultrafine wires w ₁ and w ₂ is severe, a wire break will occur during wire passing, and the operation will have to be stopped.
The inventors of the present invention investigated the relationship between the bending angle θ and the wire diameter deviation a at the welded portion, that is, the relationship between the straightness and the wire drawing trouble (mainly wire breakage) in the ultrafine wire having a wire diameter of 44 μm. The results shown in are obtained. That is, when the bending angle θ exceeds 10 °, the wire diameter deviation a is 6 μm.
It was found that wire drawing becomes impossible when the value exceeds.

That is, in order to obtain the straightness of the weldable portion where wire drawing is possible, it is necessary to set the bending angle θ ≦ 10 ° and the wire diameter deviation a ≦ 6 μm. Therefore, in the present invention, a special jig is used to accurately butt the short portion of the ultrafine wire, and the butted portion is spot-welded with a laser.

The ultrafine wire product to be produced by the method of the present invention is a metal wire having a wire diameter of 20 μm or less, which is used for, for example, a screen printing gauze for high precision printing. A material for drawing a wire, that is, a thin wire to which the method of the present invention is applied has a wire diameter of about 40 to 50 μm (hereinafter simply referred to as a thin wire material). However, the wire diameter is not limited, and it goes without saying that the present invention can be applied to other materials and diameters.

The fine wire material is subjected to patenting treatment in a lead bath or an inert gas to form a uniform structure of pearlite, remove work strain and soften the wire easily. If necessary, surface treatment such as Ni plating is performed to improve lubricity during wire drawing.

FIG. 3 shows an example of welding the thin wire material treated as described above, in which the thin wire materials 1 and 2 are adhesively fixed to the surface of the adhesive tape 3 and the respective ends are brought into contact with each other. I have to meet. This method is difficult to match the thin wire materials 1 and 2 together, but is the simplest method to get used to in a short time and manually. At this time, adhesive tape 3
It is preferable to use a double-sided tape so as not to move, and fix the back side to a table or the like to work. After the butting, the butted portion is irradiated with the laser beam 4 for a short time to form the welded portion 5.

4A and 4B show another example of welding a thin wire material. FIG. 4A is an overall perspective view and FIG. 4B is a side view. As shown in the figure, this is a jig composed of a glass substrate 6 and a holding plate 7, and on the surface of the substrate 6, fine grooves 8 through which the thin wire materials 1 and 2 pass are provided. That is, the fine wire materials 1 and 2 are inserted into the fine groove 8 provided in the substrate 6, and the ends (faces) thereof are abutted so as to come into contact with each other, and then the cover plate 7 is fixed with the lid, and the laser beam 4 is used for a short time. If it is irradiated, the butted portion is welded 5. If the thin groove 8 is made slightly larger than the diameter of the thin wire material and the thin wire materials 1 and 2 are inserted from both ends of the thin groove 8 while being guided, both ends of the material can be easily butted against each other visually. Presser plate 7 at this time
If you cover with, you can guide more reliably.

FIGS. 5A and 5B show still another welding jig. The thin wire materials 1 and 2 are supported by the attachment jigs 9 and 10. As shown in FIG. 2B, the mounting jigs 9 and 10 have a base 11 having a groove 12 for supporting the thin wire materials 1 and 2 at the center thereof, and a thin wire material 1 and 2 fitted into the support groove 12. It is composed of a presser tool 13 for pressing and fixing. The shape of the support groove 12 is V-shaped in the case shown, but is not limited to this, and may be U-shaped or arc-shaped, for example, and a groove into which a thin wire material can be fitted. May be formed. In these cases, the retainer 13 is also shaped to fit into the support groove 12. As shown in FIG. 1A, one mounting jig 9 is fixed to a support 14, and the other mounting jig 10 rocks the jig 10 so that the tip of the supporting thin wire material 2 can be aligned. The stage 16 is supported by a freely adjustable three-axis adjusting stage 16, and the stage 16 is supported by a table 15 provided so as to be movable in x, y, and z directions. That is, the thin wire material 1 is supported by the mounting jig 9 fixed to the support column 14 to fix the tip position, and the thin wire material 2 is fixedly supported by the mounting jig 10 supported by the triaxial adjustment stage 16. Therefore, the movable table 15 and the triaxial adjustment stage 16
Can be aligned with the tip of the thin wire material 1,
After the butting, the laser beam 4 is irradiated to weld as in the above example. A sensor detector may be provided at the abutting of the ends of the two materials to detect contact between the ends, and a detection signal may be input to oscillate the laser beam.

The laser beam is applied in a pulsed or continuous manner, and the input energy is adjusted according to the material and size of the thin wire material. Although it is possible to perform welding in a short time by irradiating a laser beam, since the welded portion is cooled and hardened by the outside air, it is preferable to shift the focal length after welding and irradiate and anneal in the lengthwise direction of the welded portion. As a result, the cross-sectional hardness in the longitudinal direction can be dispersed as shown in FIG. Various lasers can be used to perform such an operation, but a YAG laser is preferable from the viewpoint of adjusting the incident energy and the ease of focusing when performing fine wire welding.

By accurately aligning the thin wire materials and carrying out the laser welding in this manner, the straightness of the welded portion becomes extremely good, and the drawn wire rods can be continuously connected with high precision, and the ultrafine wire Endless wire drawing is possible.

[0015]

[Example] As a steel component (wt%), C: 0.81%, S
i: 0.24%, Mn: 0.54%, P: 0.009
%, S: 0.007% The balance is essentially Fe.
A thin wire material having a diameter of 2 mm was subjected to lead patenting, Ni-plated, and drawn to a diameter of 0.044 mm.

This ultra-fine steel wire is made to have an incident angle at a right angle to this butt portion in a state where both ends of the fine wire are in contact with each other on the triaxial fine adjustment stage of FIG. Irradiated with a laser beam. Laser irradiation was performed under the conditions shown in Table 1 by the following method. Equipment used Model name: ML-2300A Pulse: Pulse with YAG laser Lens focal length: 40 mm Optical system: Fixed optical system With CCD camera

[Table 1]

Line deviation (a) of the obtained welded part: 1.5 μ
m, bending angle (θ): accuracy of 7 °, wire diameter 0.04
When a total of 17 passes were conducted so that the diameter was changed from 22 mmφ to 0.020 mmφ, continuous wire drawing could be performed without any breakage.

[0018]

As described above, according to the method of the present invention, the conventional wire threading work is not required, and the straightness is extremely good, and accurate welding can be performed. It is possible to achieve continuous endless drawing of ultra-fine wires. Also, welding and annealing can be performed with the optimum laser intensity, and a sound welded portion can be secured.

[Brief description of drawings]

FIG. 1 is an explanatory view of straightness in a welded portion.

FIG. 2 is a diagram showing a relationship between a bending angle exerted on wire drawing and a wire diameter deviation.

FIG. 3 is an explanatory view showing an example of welding the thin wire material of the present invention.

FIG. 4 is an explanatory view showing another example of welding the thin wire material of the present invention, in which (a) is a perspective view and (b) is a side view.

FIG. 5 is an explanatory view showing another example of welding the thin wire material of the present invention, (a) is a front view and (b) is a side view.

FIG. 6 is a diagram showing the hardness of the as-welded and annealed after-welding welds.

[Explanation of symbols]

 1, 2: Fine wire material 3: Adhesive tape 4: Laser beam 5: Welded part 6: Glass substrate 7: Glass holding plate 8: Fine groove 9, 10: Mounting jig 11: Base 12: Support groove 13: Presser foot 14: Support post 15: Table 16: 3-axis adjustment stage

Claims (1)

[Claims] 1. A patented wire after wire drawing and, if necessary, a surface treatment of Ni or the like is used to fix the ends of the thin wires to be joined together by using a holding jig, and the abutted portion is fixed. Laser welding is performed, and the wire diameter deviation (a) at the welded portion is 6 μm or less, and the bending angle (θ) of one wire to the other is straightness of 10 ° or less. Butt welding method for extra fine wires.