JPH10249534A - Method for joining welding wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To join the welding wire with the strength necessary for stably feeding the welding wire without generating any burrs in a joined part by joining the welding wires so that the side parts at the tip of the welding wires each and part to be joined is formed in a ridge shape and arranged opposite to each other in the mutually crossing manner. SOLUTION: The apex angle θ of the ridge of welding wires W1, S2 to be joined with each other is preferably 80-120 deg.. The welding wire W2 clamped to a movable side electrode D2 is brought into contact with the welding wire W1 clamped to a fixed side electrode D1 with the angle intersection between the side parts E1, D2 being 90 deg.. Energization is started as soon as the contact of the wires, and heat generation is started. The welding wires W1, W2 are constantly brought into contact with a center part of the wire diameter, the center part is melted, the melting is expanded in the outer circumferential direction, the welding wire W2 is pressed against the welding wire W1, the molten metal is projected, and energization is shut off immediately before the projected molten metal becomes burns. The procedure can be served for the welding without generating any burrs on the joined parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining welding wires used for, for example, MIG welding, mag welding, carbon dioxide arc welding, and the like.

[0002]

2. Description of the Related Art A welding wire wound around a reel,
When performing the above-mentioned MIG welding or carbon dioxide gas arc welding using a welding wire stored in a pail can, the end of the welding wire cannot be fed any more and is used for welding. Terminal loss that cannot be performed. This length corresponds to the distance from the feed roller of the welding machine to the welding torch via the conduit cable,
For example, every time a welding wire reel (20 kg or 25 kg winding) or a pail can (200 kg or 250 kg winding) is replaced, 700 mm to 4000 mm is used.
Some wire will be discarded.

[0003] In order to prevent such a loss of the welding wire, a butt welding machine for joining the terminal end of the welding wire to be used to the beginning of a new welding wire for replacement is commercially available.

[0004]

However, when welding wires are joined in the usual procedure using the butt welding machine described above, it is not possible to suppress the occurrence of burrs due to the protruding molten metal. There is.

That is, in a welding method such as the above-described MIG welding or carbon dioxide gas arc welding, the burrs hinder the passage of the welding wire through the feed roller and the current-carrying tip in the welding torch. However, such a work of removing burrs, particularly a work of removing a small-diameter welding wire, is complicated and time-consuming. Therefore, the development of a welding wire joining method capable of suppressing the generation of burrs and reducing the work of removing burrs has been an issue for eliminating terminal loss of welding wires and reducing welding costs.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in a conventional welding wire joining method, and is intended to provide a welding wire necessary for stable feeding of a welding wire without generating burrs at a joining portion. An object of the present invention is to provide a welding wire joining method that can reliably obtain strength and can be used for welding as it is without performing a burr removal operation after joining.

[0007]

In order to achieve the above object, the present inventor has proposed that the welding conditions for butt welding, the tip shape of the welding wire to be joined, and the smooth feeding of the welding wire to the welding torch. As a result of intensive studies on the joint strength necessary for performing stable welding, it is necessary to prevent the welding part of the welding wire from being broken by the tensile force of the feed roller or buckling in the conduit cable Although the feed resistance slightly varied depending on the welding equipment used, it was confirmed that it was sufficient to withstand a tensile load of about 2.5 kg, and it was not necessary to necessarily perform welding at a joint cross section equivalent to the wire cross section. .

In order to prevent burrs from being generated during butt welding, the welding wire is joined at the center of the wire so that the molten metal does not protrude beyond the wire diameter of the welding wire in any direction. Must be
For this purpose, it is necessary to form the welding tip of the welding wire into a mountain shape and join the welding wire in a state where the ridges of the tip of the welding wire formed in the shape intersect each other. The inventors have found that this is extremely effective in that the wires can always be brought into contact with each other near the center of the wire.

The present invention is based on the above findings, and the method for joining welding wires according to the first aspect of the present invention, when joining welding wires by butt welding,
It is characterized in that the ends of both wires to be joined are formed in a chevron shape, and a configuration is adopted in which the ridges at the tips of the welding wires formed in the chevron face and join each other in a state of crossing each other. The configuration of the wire bonding method is used as means for solving the above-mentioned conventional problems.

According to a second aspect of the present invention, there is provided a method for joining welding wires, wherein when welding wires are joined by butt welding, the ends of both wires to be joined are cut into a mountain shape. In addition, in a configuration in which the ridges of the tips of the welding wires that are cut into a mountain shape face each other in a crossing manner, the welding method according to claim 3 is also an embodiment. A configuration in which the ridge lines cross in a cross shape,
In the welding wire joining method according to the fourth aspect, the peak angle θ of the chevron at the tip of the welding wire is 80 to 120 °. When the end is cut into a mountain shape, the end is cut by using a double-edged wire cutter, and the structure of such a welding wire joining method is a means for solving the above-mentioned conventional problems.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The butt welding apparatus used in the welding wire joining method according to the present invention is not particularly limited, and a conventional commercial product can be used.
In order to prevent the occurrence of burrs due to the protrusion of the molten metal, it is necessary to set conditions slightly different from those of conventional butt welding.

That is, as described above, the ends of the two wires to be joined are each formed into a mountain shape, and then energization is started in a state where the ridges of the cutting end portions forming the mountain shape cross each other to join. However, it is desirable to adjust the set interval of the welding wires so that energization is started immediately before the two welding wires come into contact with each other. Further, as for the pressing force at the time of joining, it is desirable to adopt a minimum pressing force that satisfies the followability at the time of melting of the wire. It is desirable to stop the energization when the melting of the welding wire has progressed to the middle of the mountain-shaped portion at the tip of the wire.

In the method of joining welding wires according to the present invention, the type of welding wire is not particularly limited, and the present invention can be applied to mild steel to high-tensile steel, stainless steel welding wires, and the like.

Also, the diameter of the welding wire is not particularly limited, and can be widely applied to, for example, a welding wire of about 0.8 mm to 4.8 mm.

The crossing angle of the ridge portion at the tip of the welding wire may be a cross, that is, 90 °, as described in claim 3, so that the welding wires are always in point contact with each other at the start of joining. This is desirable in that the contact area at the beginning of energization can be kept constant and the amount of heat generated can be stabilized.

Further, as described in claim 4, the angle of the apex of the chevron at the tip of the welding wire is desirably in the range of 80 to 120 ° in order to reduce the variation in joint strength and burr generation.

Further, when the welding tip of the welding wire is formed into a mountain shape, for example, a double-edged wire cutter is cut at right angles to the welding wire to cut the welding wire. The ends can be easily angled.

[0018]

In the method for joining welding wires according to the first aspect of the present invention, the ends of the two wires to be joined are each formed into a mountain shape, and the ridges at the tip ends of the mountain-shaped wires are crossed with each other. In this state, the power supply is started and the joining is performed, so that the tip shape is always constant, and the welding wires are always in contact with each other at a position near the center of the wire at the time of joining. Therefore, the welding wires are always joined at the center of the wire, and the molten metal is stably held between the chevron-shaped wire end faces. Sufficient bonding strength can be stably obtained.

FIGS. 1A to 1D are process diagrams showing the progress of butt welding at this time.
As shown in FIG. 1, the welding wire W2 clamped on the movable electrode D2 approaches the welding wire W1 clamped on the fixed electrode D1, and the welding wire W2 clamped to the electrodes D1 and D2 at the position shown in FIG. The energizing circuit is closed.

Then, in FIG. 1C, the welding wire W
1, the ridges E1 and E2 at the tips of W2 come into contact with each other, and at the same time as the contact, the energization is started and heat is generated. At this time, since the welding wires W1 and W2 always come into contact with each other at a position near the center of the wire diameter, the welding wires W1 and W2 always start to melt from the center, and the melting increases in the outer peripheral direction of the wire, and When the wire W2 is pressed against the welding wire W1 and the current is cut off immediately before the molten metal protrudes and becomes a burr, as shown in FIG.
The welding wires W1 and W2 are joined at the center without generating burrs.

In this case, it is required that the power supply be cut off at the same time as the melting of the welding wires W1 and W2 has progressed to the middle of the mountain-shaped portion. In the present invention, the welding wires W1 and W2 are turned off. Since the butt ends are formed in a chevron shape, the energization area expands synergistically as the energization time elapses, and the resistance heating decreases synergistically with the energization area. , The allowable range of the timing for interrupting the butt welding is large, and the appropriate range of the butt welding condition is wide.

According to a second aspect of the present invention, there is provided a method for joining welding wires, in which the ends of both wires to be joined are cut into a mountain shape. Is easy to form.

In the welding wire joining method according to the third aspect of the present invention, since the chevron ridge at the tip of the welding wire is crossed in a cross, the welding wires are always in point contact with each other at the start of joining. As a result, the contact area between the wires in the initial stage of energization is always constant, the heat generation is stabilized, and the bonding strength of the welding wire and the state of occurrence of burrs are more stable without variation.

In a welding wire joining method according to a fourth aspect of the present invention, the angle of apex θ at the tip of the welding wire is in the range of 80 ° to 120 °, so that the joining speed of the wire is appropriate. As a result, variations in the bonding strength and variations in the state of occurrence of burrs are eliminated, and the range of conditions for obtaining good bonding results becomes wider. As a further embodiment, in the welding wire joining method according to the fifth aspect, when the joining end of the welding wire is cut into a mountain shape, the welding end is cut using a double-edged wire cutter. And the angle of the apex angle θ of the chevron at the tip of the wire can be easily adjusted by selecting the cutting edge angle of the wire cutter to be used.

[0025]

The method for joining welding wires according to the first aspect of the present invention has the above-described structure. Therefore, a condition range for obtaining a predetermined joining strength without generating burrs at the joint portion. The welding wire can be easily joined to each other easily, without performing complicated deburring work.
This provides an extremely excellent effect that the joined welding wire can be directly used for welding.

[0026] As an embodiment of the welding wire joining method according to the present invention, in the joining method according to the second aspect, since the ends of both welding wires to be joined are cut into a mountain shape, the tip end of the welding wire. Can be easily formed into a mountain shape, and in the welding wire joining method according to the third aspect as an embodiment, the ridges at the tips of the welding wires are made to cross in a cross shape, so that when joining is started, Since the welding wires can always be brought into point contact with each other and the welding progresses more stably, it is possible to achieve more consistent joining. In the welding wire joining method according to claim 4, the welding wire tip Since the apex angle θ of the chevron is in the range of 80 ° to 120 °, the bonding speed of the wire becomes appropriate, and the variation in the bonding can be eliminated. In the welding wire joining method according to 5, since the joining end of the welding wire is cut using a double-edged wire cutter, the welding wire to be joined is to be joined according to the cutting edge angle of the wire cutter to be used. Has an excellent effect of easily cutting the end portion into a chevron having a desired angle.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Inventive Example An end of a carbon dioxide arc welding wire (1.2 mm diameter) W1 for mild steel and 50 kg high-tensile steel specified as YCW1 in JIS Z 3312, the apex angle .theta. ° was cut into a mountain shape. Then, as shown in FIG. 2, the welding wire W2 of the same kind, which has been cut in the same manner, is opposed to the welding wire W2, and the ridges E1 and E2 at the tips of the welding wires W1 and W2 are positioned so as to cross each other. As shown in (a), they were respectively clamped to the electrodes D1 and D2 of the butt welding apparatus.

Then, the current is 0.5 A and the pressure is 0.8
The butt welding was carried out under various conditions by changing the energizing time to 5,000 kg, and the occurrence of burrs at the joints and the joint strength (rupture load) were examined.

Table 1 shows the results.

[0031]

[Table 1]

When cutting the welding wires W1 and W2, as shown in FIGS.
By using a wire cutter C having a cutting edge angle of 90 °, the vertex angle θ of the wire tip is made 90 °, and when the vertex angle θ is 60 °, the wire is cut using the cutter C. After that, the angle was adjusted by file finishing.

Conventional Example The ends of the same welding wires W1 and W2 as those of the above-mentioned invention were cut by using a shearing type wire cutter so that the ends became substantially flat. 0.5
A, butt welding was performed by changing the energizing time to two steps with a pressing force of 0.8 kg, and the occurrence of burrs at the joint and the joint strength were examined.

Table 2 shows the results.

[0035]

[Table 2]

As a result, as is apparent from Tables 1 and 2, the joining ends of the welding wires W1 and W2 are set at the apex angle θ =
Cut into 90 ° chevron, and ridges E1 and E2 at the wire tip
In the case of the invention example in which are joined at right angles to each other, no burr is generated over a wide energizing time, and 2.5 kg
While the above bonding strength is obtained, the welding wires W1,
In the case of the conventional example in which the end of W2 is cut into a substantially planar shape,
None of them could prevent the generation of burrs, and it was confirmed that the work of removing burrs was indispensable for providing the joined welding wires for welding.

Further, when the joining ends of the welding wires W1 and W2 are cut into a chevron with an apex angle θ = 60 °, the occurrence of burrs is eliminated and a predetermined joining strength cannot be obtained. Large variations in strength, burr generation,
It turned out that the stability as a joining method was slightly lacking.

[Brief description of the drawings]

1 (a) to 1 (d) are schematic process diagrams sequentially explaining the progress of butt welding in a welding wire joining method according to the present invention.

FIG. 2 is a perspective view showing a positional relationship of welding wires to be joined in a welding wire joining method according to the present invention.

FIGS. 3A and 3B are a perspective view and a cross-sectional view, respectively, showing an example of a procedure for cutting a welding wire in a welding wire joining method according to the present invention.

[Explanation of symbols]

 W1, W2 Welding wire E1, E2 Ridge

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masayuki Iwase Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa

Claims (5)

[Claims] When joining welding wires by butt welding, the ends of the two wires to be joined are formed in a mountain shape, and the ridges at the tips of the welding wires formed in a mountain shape face each other. A method for joining welding wires, comprising joining together. 2. When joining welding wires by butt welding, the ends of both wires to be joined are cut into a chevron, and the ridges at the tips of the welding wires cut into a chevron face each other. The welding method according to claim 1, wherein the welding wires are joined together. 3. The cross section of a mountain-shaped ridge at the tip of a welding wire.
The joining method of the welding wire according to 1. 4. The angle θ of the chevron at the tip of the welding wire is 80 to
The welding wire joining method according to any one of claims 1 to 3, wherein the angle is 120 °. 5. The welding wire joining method according to claim 2, wherein when the end of the wire is cut into a mountain shape, the end is cut using a double-edged wire cutter.