JPH082503B2 - Resistance seam welder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resistance seam welder for a goby fold portion of a material to be welded, and particularly to a goby fold portion and an anchor piece for fixing the goby fold portion. In the case of resistance seam welding, the present invention relates to a resistance seam welding machine in which the position of the anchor piece is accurately detected to prevent the welded portion at that position from causing discontinuity or the like.

[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. In order to lay the roof plate, as shown in FIGS. 4 and 5 (the synthetic resin layer is omitted, the same applies to the following figures), the adjacent damping steel plates 10a and 10b are used. While rotating 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, anchor pieces 12 referred to as suspenders for fixing the roof to the inner roof member 30 are arranged at regular intervals (the pitch is about 400 to 600 mm).
It is necessary to simultaneously perform resistance seam welding of four vibration damping steel plates 10a and 10b at the goby fold portion 11 together with the anchor piece 12. The nugget of weld 14 is
As shown in FIG. 5, it is desirable to continue with a constant width regardless of the presence or absence of the anchor piece 12, and if it is intermittent, rain leakage or corrosion will occur from that part and it will be a big problem. Become.

The thickness of the vertical part 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 6 (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. 6 (b) entered
t ₁ is 1.4 mm.

Because of this change in thickness, and resistance seam welding of stainless steel vibration-damping steel plates, the range of appropriate welding conditions is narrower than welding of a single stainless steel plate, and 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 the 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.

Since it is known that welding conditions can be changed at the position to secure the continuity of the nugget 14a at the entrance and the exit of the anchor piece 12, the detection of the position of the anchor piece 12 becomes extremely important. As a means for detecting this position,
Conventionally, for example, the one shown in FIG. 8 has been used. This is one in which a load cell is incorporated in the machining mechanism of a pair of electrode wheels. In the figure, 31 is a load cell, 8a and 8b are electrode wheel arms for supporting the electrode wheels 2a and 2b, respectively, and the welding machine main body ( A shaft 9 (not shown) pivots the shaft 9 so that the shaft 9 can be freely opened and closed. 32 is a return spring attached between the electrode wheel arms 8a and 8b, 33 is a pressurizing spring for pressurizing one of the electrode wheel arms 8a, and is provided between the frame 34 of the welding machine body. There is. Reference numeral 35 is a pressure adjusting screw for setting the load cell 31 attached to the other electrode wheel arm 8b.

According to this detection device, the electrode wheels 2a and 2b are fixed to the anchor piece 12
Since the electrode wheel arm 8b is slightly displaced according to the change in the thickness of the goby fold portion 11 when approaching to the position, a corresponding load change appears in the load cell 31, and by detecting this, the lower piece 12 of the lower piece is detected. The position can be detected.

[Problems to be Solved by the Invention] However, the difference in thickness of the goby-folded portion 11 is as small as 0.2 mm as described above, and at the time of welding, the electrode wheel 2a,
Since the movement of 2b is irregular, it is difficult to accurately detect the amount of change in the thickness, and it is almost impossible to detect the position of the anchor piece 12.

Further, even if the position can be detected, it takes time to switch the welding conditions, so that the discontinuity of the nugget 24a at the entrance of the anchor piece 12 cannot be eliminated.

Therefore, the present invention is capable of reliably detecting a minute amount of change in the thickness of the goby-folded portion as described above, thereby accurately detecting the position of the anchor piece, and ensuring the continuity of the nugget. It is intended to provide a welding machine.

[Means for Solving the Problem] In order to achieve the above object, the resistance seam welding machine according to the present invention is provided at a position in front of the pair of electrode wheels in the welding direction (position preceding the electrode wheel). A micro-displacement sensor for detecting a micro-displacement is provided between each arm of a pair of traveling wheels arranged. The traveling-wheel arm can be opened and closed with respect to each other like the electrode-wheel arm. Each of them is supported by a traveling wheel, and at the time of welding, the goby folds are rotated while being pressed from both sides to run. The minute 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. It is a thing.

[Operation] When the running wheel approaches the position of the anchor piece, the running wheel arm opens slightly. This small fluctuation causes elastic displacement of the cantilever, so that the strain gauge attached to the cantilever causes a clear change in electrical output at that position. Further, unlike the electrode wheels, the running wheels have relatively stable movements even during welding, so that the change in the electrical output can be easily identified. As a result, the position of the anchor piece can be accurately detected.

If the position of the anchor piece is known, the electrode wheel is behind the running wheel, so the welding conditions can be switched sufficiently by the normal delay circuit, and the continuity of the nugget at the anchor piece can be maintained. .

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an embodiment of a resistance seam welding machine of the present invention, and FIG. 2 is a side view of the same. Although these drawings do not show the position detecting device of the anchor piece of the present invention, This is shown in detail in FIG.

As shown in FIGS. 1 and 2, the main body 1 of the welding machine is made of the above-mentioned stainless steel damping steel plates, the materials to be welded 10a, 10b.
It is mounted on the goby folding part 11 so that it can 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. A pair of running wheels 3a, 3b that rotate in the above state, a front guide roller 4 and a rear guide roller 5 that roll on the goby folding portion 11 to be welded, and roll on the adjacent goby folding portion 11 And side rollers 6. 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 and 8b have shaft 9 as shown in FIG.
Are pivotally supported on the welder body 1 so as to be openable and closable with respect to each other, and rotating shafts 13a, 13b penetrating the electrode wheel arms 8a, 8b.
The electrode wheels 2a and 2b are attached to the lower ends of the respective. 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).

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

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.

The small displacement gauge 22 shown in FIG. 3 is an arm for one traveling wheel.
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 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, 3b are rotated in this state and the welding machine body 1 is caused to travel, the seam folds 11 are resistance seam welded by the electrode wheels 2a, 2b, but the traveling wheels 3a, 3b are anchor pieces. When approaching, the traveling wheel arms 17a and 17b open a very small amount because the thickness of the goby folding portion 11 changes. This movement contacts the stator 27
A cantilever 24 in constant elastic contact via 25
The strain gauge 23 changes the electrical output. Further, the traveling wheels 3a, 3b, unlike the electrode wheels 2a, 2b, move stably even during welding, so that the change in the electrical output can be easily discriminated. As a result, the anchor piece
Since the position of 12 can be detected accurately, the detection signal is sent to the welding control device (not shown) installed in the welding machine main body 1, and the delay circuit causes the electrode wheels 2a and 2b to move the anchor piece. If the welding conditions are changed when the position of 12 is reached, the nugget at the entrance and the exit of the anchor piece 12 will not be completely separated or extremely thin as in the conventional case, and the anchor piece 12 will not be present. It can be made continuous with a constant width like the point.

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 the electrode wheels 2a, 2b approach the exit position. Welding conditions will be restored. Thus, the continuity of the nugget can be ensured at the entrance and the exit of the anchor piece 12.

[Effects of the Invention] As described above, according to the present invention, the minute displacement gauge is provided between the arms of the pair of running wheels that travel to the pair of electrode wheels for resistance seam welding of the goby fold of the material to be welded. Therefore, the running wheel, unlike the electrode wheel, moves stably during welding,
Therefore, the minute displacement meter can reliably detect a minute amount of change in the thickness of the goby folded portion. Therefore, it is possible to accurately detect the position of the anchor piece to be welded together with the goby fold portion, and moreover, it is possible to sufficiently secure the switching time of the welding condition, so that the continuity of the seam welded portion at the entrance and the exit of the anchor piece is maintained. There is an effect that can be secured.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the resistance seam welding machine of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a front view showing a mounted state of a micro displacement meter of the present invention. Fig. 4 is an explanatory view of a conventional resistance seam welding method for a goby fold, Fig. 5 is a side view of Fig. 4, and Figs. 6 (a) and 6 (b) are locations where an anchor piece is not included in the goby fold. Explanatory diagram showing the part containing
FIG. 7 is an explanatory view showing the discontinuity of the welding nugget at the entrance and the exit of the anchor piece, and FIG. 8 is a front view showing the mounting state of the conventional thickness detecting device. 1 …… Welder body 2a, 2b …… Electrode wheel 3a, 3b …… Running wheel 8a, 8b …… Electrode wheel arm 9 …… Shaft 10a, 10b …… Welding material 11 …… Haze fold 12 …… Anchor piece 17a, 17b …… Rolling wheel arm 22 …… Small displacement gauge 23 …… Strain gauge 24 …… Cantilever 25 …… Contact 26 …… Adjustment screw 27 …… Stator

Front Page Continuation (72) Inventor Sakano et al. Marunouchi 1-2-2 Nihon Steel Pipe Co., Ltd., Chiyoda-ku, Tokyo (72) Inventor Hisao Kurosawa 1-2-1 Marunouchi Chiyoda-ku Tokyo In-house (72) Inventor Mitsui Mitsui, 2-1-1, Nishishinjuku, Shinjuku-ku, Tokyo Within Nippon Metal Industry Co., Ltd.

Claims (1)

[Claims] 1. A pair of electrode wheels for resistance seam welding the goby folds of a material to be welded, and a pair of electrode wheels arranged at a position in front of the electrode wheels in the welding direction and rotated with the goby folds being pressed from both sides. A resistance seam welding machine having a pair of traveling wheels and a pair of traveling wheel arms that support each of the traveling wheels and are pivotally supported by a welding machine body so as to be openable and closable relative to each other. A resistance seam welding machine characterized in that a minute displacement gauge for detecting minute displacement between the arms is provided between the wheel arms.