JPH082504B2 - Resistance seam welding method for goby fold of welded material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resistance seam welding method for a goby fold portion of a material to be welded, and particularly to a goby fold portion when a damping steel plate is used as the material to be welded. The present invention relates to a method of rotating an electrode wheel while sandwiching an area where an anchor piece for fixing the area is present and an area where the anchor piece is not present from both sides by a pair of electrode wheels to continuously perform resistance seam welding.

[Prior Art] Recently, damping steel sheets have come to be used as roofing materials for large buildings such as gymnasiums. As is well known, the vibration-damping steel plate has a sandwich structure in which a thin synthetic resin layer is sandwiched between two thin steel plates to be integrally formed. It does not produce rain noise and has a high degree of freedom in architectural design. Is widely used as a roof material.

Generally, a stainless steel plate is used as a damping steel plate as a roofing material, and the thickness of the damping steel plate is about 0.4 mm in total. To lay a roof plate, as shown in FIGS. 6 and 7 (the synthetic resin layer is omitted, the same applies to the following drawings), the adjacent damping steel plates 10a and 10b are used. While gripping the goby fold portion 11 with the pair of electrode wheels 2a and 2b from both sides, the electrode wheels 2a and 2b are rotated and joined by resistance seam welding in the welding direction indicated by the arrow a. At this time, a large number of anchor pieces 12 referred to as suspenders for fixing the roof to the inner roof member 30 are attached at regular intervals (the pitch is about 400 to 600 mm). Further, it is necessary to simultaneously resistance-seam weld four damping steel plates 10a and 10b at the goby fold portion 11. As shown in FIG. 7, the nugget of the welded portion 14 is preferably continuous with a constant width regardless of the presence or absence of the anchor piece 12, and if it may be intermittent, rain leakage or corrosion may occur from that portion. Causes a big problem.

[Problems to be Solved by the Invention] The thickness of the vertical portion of the anchor piece 12 to be welded is 0.2 m.
Although it is very thin such as about m, the anchor piece 12
There is a 0.2 mm difference in the total thickness of the goby-folded portion 11 between the portion where the marks are formed and the portion where it is not formed. Figure 8 (a), (b)
Shows this relationship, and the total thickness t ₀ of the goby-folded portion 11 is 1.
2mm, the total thickness at the place where the anchor piece 12 in Fig. 8 (b) entered
t ₁ is 1.4 mm.

Because of this change in thickness, and because resistance seam welding of stainless steel damping steel plates has a narrower range of appropriate welding conditions than welding of a single stainless steel plate, so-called surface burning is likely to occur, so the continuity of the nugget 14a is maintained. Therefore, it is necessary to change the welding conditions at the location of the anchor piece 12 and other locations.

In the conventional case, the welding current mode is intermittent, or the welding speed is reduced to 1/2 or less at the anchor piece 12 for welding, but still at the inlet and outlet of the anchor piece 12, FIG. As shown in, there was a problem that the nugget 14a became extremely thin or completely separated, and the sealing property of the roof plate became incomplete. It may be possible to repair such an incomplete sealing property later, but the work is extremely difficult because the number of anchor pieces 12 is tens of thousands.

Therefore, the present invention prevents the discontinuity of the nugget at the inlet and outlet of the anchor piece as described above, the resistance seam welding method of the goby fold portion of the welded material to complete its sealing property. It is intended to be provided.

[Means for Solving the Problems] In order to achieve the above object, the resistance seam welding method for the goby fold portion of the material to be welded according to the present invention has a pair of positions of the anchor pieces attached to the goby fold portion described above. The position detection device is located at a position in front of the electrode wheel in the welding direction (position preceding the electrode wheel), and based on the detection signal, the welding condition is changed after a certain time or a certain distance to change the resistance seam. Welding, in this case,
Welding conditions are such that the energization mode is intermittent in the region where the anchor piece does not exist in the goby fold part, and the energization mode is continuous in the region where the anchor piece exists in the goby fold part. The welding current is made larger and the welding speed is made slower.

Further, the position detecting device uses a minute displacement meter capable of detecting a minute amount of change in the thickness of the goby-folded portion, and the minute displacement meter is used for each of a pair of running wheels arranged at a position preceding the electrode wheel. It is good to provide it between the arms. The small displacement gauge provided between the pair of traveling wheel arms is provided with, for example, a cantilever that responds to the movement of the traveling wheel arm, and the displacement of the cantilever is taken out as an electrical output by a strain gauge. .

[Operation] The position of the anchor piece is detected before the electrode wheel reaches that position, and the welding conditions are changed by delaying it for a certain time or a certain distance from the time of detection. Therefore, the welding conditions can be changed sufficiently in time, and the continuity of the nugget can be secured under the above welding conditions even when the range of proper welding conditions is narrow, such as a stainless steel damping steel plate. .

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a time chart of welding conditions in the present invention. FIG. 1 (a) shows the waveform of the position detection signal h of the anchor piece 12 by the position detection device.
The electrode wheels 2a and 2b will approach the entrance of the anchor piece 12 after a certain time T ₁ from the time when the occurrence of the occurrence of. Therefore, as shown in (b), the welding current is set to a current I ₂ larger than the current I _{1 in the} region where the anchor piece 12 does not exist,
This is maintained for the time T ₂ during which the electrode wheels 2a and 2b pass through the anchor piece 12. Also, in the region where the anchor piece 12 exists, the welding speed is set to the velocity v ₂ slower than the velocity v _{1 in the} region where the anchor piece 12 does not exist, as shown in (c). For example, in the region of the three plates of the damping steel plates 10a, 10b (the region where the anchor piece 12 does not exist), the welding current I ₁ = 2800A, the welding speed v ₁ = 1500mm / min when the applied pressure of the electrode wheels 2a, 2b is 160kg.
In the region where the anchor piece 12 exists, the electrode wheels 2a, 2b
Welding pressure I ₂ = 3200A, welding speed v ₂ = 1300m
It is set to m / min. Welding conditions in the case of stainless steel vibration-damping steel plate are particularly delicate, but the appropriate range is that the welding current is increased by 20 to 30% and the welding speed is reduced by 15 to 20% in the region where the anchor piece 12 is present. Is appropriate. The upper limits of these welding currents and welding speeds are limited by the surface burning of the welds, and the lower limits are limited by the weldability and continuity of the welds.

Further, as shown in (d) and (e), the energization mode is set to the intermittent type in the region where the anchor piece 12 does not exist and the continuous type in the region where the anchor piece 12 exists. The reason is that in the case of a stainless steel vibration-damping steel plate, it is necessary to secure the continuity of the nugget while preventing the surface burn of the welded portion, so it is necessary to suppress the heat input to some extent in the region where the anchor piece 12 does not exist. Is because the intermittent method is suitable. On the other hand, in the region where the anchor piece 12 exists, due to the presence of the anchor piece 12, higher heat input is required, and discontinuity or the like of the nugget is particularly likely to occur at the inlet and outlet of the anchor piece 12, so This is because the continuous method is suitable for prevention.

Next, FIG. 2 to FIG. 5 show a structural example of a resistance seam welding machine for carrying out the above-described welding method. FIG. 2 is a front view showing an embodiment of this resistance seam welding machine, FIG. 3 is a side view of the same, FIG. 4 is an enlarged front view of an electrode wheel portion, and FIG. 5 is an enlarged front view of a running wheel portion. is there.

As shown in FIG. 2 and FIG. 3, the welder main body 1 has a goby fold 11 of welded materials 10a and 10b which are stainless steel damping steel plates.
It is mounted on top and is designed to run. For this reason, the welding machine main body 1 includes a pair of electrode wheels 2a and 2b for resistance seam welding of the goby fold portion 11 and the goby fold portion 11 which is arranged at a position preceding the electrode wheels 2a and 2b and is pressed from both sides. To rotate in the state 1
It has a pair of running wheels 3a, 3b, a front guide roller 4 and a rear guide roller 5 rolling on the goby folding part 11 to be welded, and a side roller 6 rolling on the adjacent goby folding part 11. . Reference numeral 7 is a support arm for the side roller 6. Further, the welder main body 1 is provided with a welding control device for appropriately changing welding conditions, a drive device for the electrode wheels 2a, 2b, and the traveling wheels 3a, 3b (neither is shown), and the like.

The electrode wheel arms 8a, 8b are pivotally supported on the welder body 1 so as to be openable and closable with respect to each other about a shaft 9 as shown in FIG. 4, and a rotary shaft 13a penetrating each electrode wheel arm 8a, 8b. The electrode wheels 2a and 2b are attached to the lower ends of 13 and 13b, respectively.
The electrode wheels 2a, 2b mesh with worm wheels 15a, 15b provided on the upper ends of the rotary shafts 13a, 13b and a worm 16 provided on the shaft 9, and are rotated by a motor (not shown). 28 is a return spring for the electrode wheel arms 8a, 8b.

Next, in FIG. 5, the traveling wheel arms 17a, 17b also have the same structure as the electrode wheel arms 8a, 8b, and are respectively attached to the lower ends of the rotary shafts 18a, 18b passing through the traveling wheel arms 17a, 17b. The traveling wheels 3a, 3b are attached, and the worm wheels 19a, 19b at the upper ends of the rotating shafts 18a, 18b are meshed with the worm 20 provided on the shaft 9 so that the electrode wheels 2a, 2b and the traveling wheels 3a, 3b are driven simultaneously. I have to.

The above-mentioned electrode wheel arms 8a, 8b and traveling wheel arms 17a, 1
7b can be opened and closed by a clamp mechanism (not shown), and is pressed by a pressing means (not shown) such as a spring or a cylinder device during welding. As a result, the running wheels 3a, 3b and the electrode wheels 2a, 2b press the goby folding portion 11 from both sides. Reference numeral 21 is a return spring for the traveling wheel arms 17a and 17b.

By the way, in the present invention, in order to detect the position of the anchor piece 12, the position detection device 22 is arranged at a position preceding the electrode wheels 2a, 2b. Therefore, as the position detection device 22,
For example, as shown in FIG. 5, a minute displacement gauge for detecting a minute change in the thickness of the goby fold portion 11 is used, and it is detected at a portion of the pair of running wheels 3a, 3b. Explaining the configuration, the minute displacement meter 22 is one of the traveling wheel arms.
It has a cantilever 24 provided on 17a and having a strain gauge 23 attached thereto. A contact 25 is attached to the tip of the cantilever 24.
Is adjustable by adjusting screw 26,
The tip of the contact 25 is constantly in pressure contact with the stator 27 fixed to the other traveling wheel arm 17b.

The output of the minute displacement meter 22 is set in a state where the cantilever 24 is flexed to some extent in advance when the traveling wheel arms 17a and 17b are clamped, that is, when the traveling wheels 3a and 3b press the goby folding portion 11. I am doing it. Therefore, when the traveling wheels 3a and 3b are rotated in this state and the welding machine main body 1 is traveled, the electrode wheels 2a and 2b cause the seam fold portion 11 to undergo resistance seam welding under welding conditions in a region where the anchor piece 12 does not exist. However, when the traveling wheels 3a, 3b approach the position of the anchor piece 12, the traveling wheel arms 17a, 17b open a slight amount because the thickness of the goby fold portion 11 changes. This movement is the stator
It appears as a displacement of the cantilever 24 that is constantly elastically contacting the contact 27 via the contact 25, and the electrical output is changed by the strain gauge 23. Then, the electrode wheels 2a, 2b reach the entrance of the anchor piece 12 after a lapse of a certain time or a certain distance from the time when the electric output is generated. Anchor piece 1
The detection signal of the position 2 is sent to the welding control device (not shown) installed in the main body 1 of the welding machine, and the delay circuit causes the electrode wheels 2a and 2b to reach the position of the anchor piece 12 at the same time. By changing the welding conditions in the region where the anchor piece 12 exists as described above, the nugget at the inlet and the outlet of the anchor piece 12 is not completely separated or extremely thin as in the conventional case, and the anchor piece is not. It can be made continuous with a constant width like the region where 12 does not exist.

Further, when the traveling wheels 3a, 3b pass through the location of the anchor piece 12, the information on the exit position is sent to the welding control device through the micro displacement gauge 22 as well, so that the electrode wheels 2a, 2b are at the exit position. When approaching, the welding conditions will be restored. Thus, the continuity of the nugget is anchor piece 12
It can be secured at the entrance and exit.

[Effects of the Invention] As described above, according to the present invention, the position of the anchor piece is accurately detected at a position preceding the pair of electrode wheels for resistance seam welding of the goby fold of the material to be welded, and the position is detected. Since the welding conditions were changed as described above with a delay of a certain time or a certain distance from the time, even if an anchor piece is present at the goby fold, it is different from the conventional method at the anchor piece inlet and outlet. The nugget does not become discontinuous or extremely thin, and the continuity of the nugget can be secured as in the area without the anchor piece, and the sealing property of the goby fold can be perfected. The effect is that you can do it.

[Brief description of drawings]

FIG. 1 is a time chart of welding conditions in the resistance seam welding method of the present invention. FIG. 2 is a front view showing an embodiment of a resistance seam welding machine for carrying out the method of the present invention, and FIG. 3 is a side view of FIG. FIG. 4 is an enlarged front view of an electrode wheel portion, FIG. 5 is an enlarged front view of a traveling wheel portion, FIG. 6 is an explanatory view of a conventional resistance seam welding method of a goby fold portion, and FIG. 7 is FIG. 8A and 8B are explanatory views showing a portion where the anchor piece is not included and a portion where the anchor piece is included in the goby fold portion, and FIG. 9 is a view of a welding nugget at an inlet and an outlet of the anchor piece. It is explanatory drawing which shows discontinuity. 1 ... Welder body 2a, 2b ... Electrode wheel 3a, 3b ... Running wheel 8a, 8b ... Electrode wheel arm 10a, 10b ... Welded material 11 ... Goby fold 12 ... Anchor piece 17a, 17b …… Rolling wheel arm 22 …… Position detection device 23 …… Strain gauge 24 …… Cantilever 25 …… Contact 26 …… Adjustment screw 27 …… Stator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sakano et al. 1-2, Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Hisao Kurosawa 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Inside the Steel Pipe Co., Ltd. (72) Inventor Mitsui Makoto Nishi 1-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside Nippon Metal Industry Co., Ltd.

Claims (1)

[Claims] 1. An area in which an anchor piece for fixing it to a goby fold portion of a material to be welded exists and an area in which there is no anchor piece,
In a method of resistance seam welding by rotating a pair of electrode wheels while sandwiching them from both sides, a position detection device in which the position where the anchor piece exists is located at a position ahead of the electrode wheels in the welding direction. The welding method according to claim 1, wherein the welding is performed by changing the welding conditions to the following welding conditions after a certain time or a certain distance based on the detection signal. In the area where the anchor piece does not exist, the conduction mode should be intermittent. In the region where the anchor piece exists, the energization mode is set to the continuous type, and the welding current is made larger and the welding speed is slower than in the region where the anchor piece does not exist.