JPH0237269B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric resistance welding tube welding device that can weld the rear end of an electric resistance welded tube without welding defects.

To manufacture pipe materials, first, a plate-shaped workpiece is processed into a tubular cross-sectional shape by roll forming.
After that, there is a method of joining the opposing sides using high-frequency welding. In this method, high frequency welding between both sides of the workpiece is performed as follows.

In other words, as shown in FIG.
The current-carrying chips (hereinafter simply referred to as chips) 3a, 3b are brought into contact with the sides 2a, 2b of the workpiece 2 being sent, and the side parts 2a, 2
b are brought into contact with each other in a V-shape. Chip 3
The current from the high frequency power supply connected to a and 3b is the first
Side part 2 forming a V shape as shown by arrows a and b in the figure
a, 2b, and at the turning point (the apex of the V-shape), it is rapidly heated due to the proximity effect and easily reaches the welding temperature. Therefore, apply pressure rolls (squeeze rolls) from both sides of workpiece 2.
When pressure is applied at step 4, the side portions 2a and 2b are welded together. In the figure, arrow A is the direction in which the workpiece 2 moves.

However, as shown in Figure 2 a and b, the chips 3a and 3b have come off from the work 2 at the rear end of the work 2, and the rear end of the work 2 is no longer welded by a length _L1 . Put it away.

For this reason, a method has been invented in which the rear end of the workpiece 2 can also be welded by welding or pressure-welding welding auxiliary pieces 5a and 5b to the rear end of the workpiece 2 and applying electricity to the workpiece 2, as shown in Fig. 3. has been done.

However, even if this method is implemented, there are the following drawbacks. The welding auxiliary piece must be cut off after welding the ERW tube, and it is inefficient to incorporate the welding and cutting of the welding auxiliary piece into the ERW tube welding line. In addition, to cut the welding auxiliary piece, it is possible to cut it at the welded part between the welding auxiliary piece and the workpiece, or to cut a part of the workpiece into rings and throw them away together, but this not only wastes the material, but also reduces the cutting work. In the former case, it takes a lot of labor time to correct the workpiece.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric resistance welding tube welding device that overcomes these drawbacks and can weld the rear end of an electric resistance welded tube without any special work before or after welding the electric resistance welded tube. shall be. The configuration of the present invention that achieves this object includes: a feeding means that is provided on the bed and feeds a material to be welded formed into a tubular shape with both sides of a plate-like member facing each other in the axial direction of the material to be welded;
In the electric resistance welding tube welding apparatus, the electric current carrying tip is provided above the bed, and the electric current carrying tip is in contact with the vicinity of the both sides during feeding of the material to be welded, and is energized to weld the both sides of the electric resistance welded tube. supported by a vertically movable table movable in the vertical direction, and an energizing jig capable of contacting the rear end of the welding material and the energizing chip and energizing the welding material by contacting the rear end of the welding material, and The present invention is characterized in that the vertically moving table is provided with a moving means for moving the energizing jig into or out of the welding material line, and a traveling means for moving the energizing jig in the welding material delivery direction.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

A front view of the electric resistance welding pipe welding device according to the present invention is shown in FIG. 4, and a view taken along the line A-A in FIG. 4 is shown in FIG.
A perspective view is shown in FIG. On the bed 11, there are three pairs of pinch rolls 13, 14, 15 as feeding means for feeding out the material to be welded (hereinafter referred to as the work) 12.
and a pair of squeeze rolls 16 for pressurizing the workpiece 12 from both sides. In this embodiment, the workpiece 12 is a plate-like member formed into a square tube shape with both sides 17 facing each other. When the workpiece 12 is being fed out, a pair of current-carrying tips 18 are brought into contact with the vicinity of the both sides 17 and energized, thereby welding the electric resistance welding tube at the portions of the both sides 17 that are pressurized by the squeeze rolls 16. Can be provided. Since the energizing chip 18 must be moved depending on the size of the workpiece 12, etc., it has the following structure. Work 1
The support member 2
0, and the dovetail groove 21 of the support member 20 is provided with a vertically movable table 22 so as to be movable in the longitudinal direction of the workpiece 12.
are fitted. A hydraulic cylinder 2 is used to move the vertically moving table 22 along the dovetail groove 21.
3 is fixed to the support member 20. Vertical moving table 22
A dovetail groove 24 is also provided in the dovetail groove 24, and a lateral moving table 25 is fitted into the dovetail groove 24 so as to be movable in a direction perpendicular to the longitudinal direction of the workpiece 12. A hydraulic cylinder 26 for moving the horizontally moving table 25 along the dovetail groove 24 is fixed to the vertically moving table 22.
The horizontal moving table 25 is provided with a vertically moving table 28 having a dovetail groove 27 so as to be movable in the vertical direction, and a hydraulic cylinder 29 for moving the vertically moving table 28 is fixed to the horizontally moving table 25. A matching transformer 30 is attached to the vertically movable table 28 on the side in the advancing direction of the workpiece 12, and a power supply cable 31 for feeding a high frequency current to the matching transformer 30 is connected. A contact support device 3 is provided below the matching transformer 30.
A pair of current-carrying chips 18 are attached via 2, and the current-carrying chips 18 are respectively brought into contact with the vicinity of both sides 17 of the workpiece 12.

The above is the basic structure of the conventional electric resistance welding pipe welding device, but the present invention includes the following means. An energizing jig that is movable in the vertical direction and in the advancing direction of the workpiece 12 is provided on the anti-matching transformer 30 side with respect to the vertically movable table 28 . Support plates 3 parallel to each other
One side of support plates 3 and 33' is attached to the vertically movable table 28, respectively, and the support plates 33 and 33' are connected and reinforced by connection members 34, 35 and 36. A suspension member 38 is attached to the connecting member 35 via a hydraulic cylinder 37 as a moving means, and by operating the hydraulic cylinder 37, the suspension member 38 is moved into or out of the line in which the workpiece 12 moves, that is, in the vertical direction. It can be moved. Also,
Rod-shaped guide pillars 39 and 40 are provided before and after the hydraulic cylinder 37 so that the suspension member 38 can maintain a substantially horizontal position even when a force is applied to the suspension member 38.
9 and 40 are slidably inserted into sliding bearings 41 and 42 fixed to the connecting members 36 and 34, respectively. A dovetail groove 43 is formed in the lower part of the suspension member 38 (see FIG. 7), and a sliding member 44 that can freely slide in the dovetail groove 43 in the feeding direction of the workpiece 12 is fixed to the suspension member 38. It is connected to a rod 45' of a hydraulic cylinder 45 as a means. An energizing jig 46 is detachably connected to the tip of the sliding member 44. The energizing jig 46 is shown in an enlarged view in the sixth figure.
As shown in the figure, a pair of current-carrying pieces 4 are placed on a holding member 47 via an insulating buffer member 48 made of rubber or the like.
9,49' is attached. The current carrying piece 4
9 and 49' are made of a material such as copper alloy so that sufficient current can be passed from the current-carrying chip 18 to the workpiece 2. Due to the above structure, the weight balance between the front and rear of the vertically movable table 28 is improved.

In this embodiment, a hydraulic cylinder is used as the moving means and traveling means, but the present invention is not limited to this, and the energizing jig may be moved linearly using a servo motor and a rack and pinion.

The operation of such an electric resistance welding pipe welding device will be explained. Workpiece 12 transferred by pinch rolls 13 and 14
is pressurized from both sides by the squeeze roll 16, so the both sides 17, which were separated from each other, are brought into pressure contact at this position. On the other hand, the high-frequency current supplied from the power supply cable 31 is transformed by the matching transformer 30, flows from the current-carrying chip 18 to the workpiece 12, and is turned back at the center of the line segment connecting the axes of the squeeze rolls 16 (SQR center 50). become. this
The workpiece 12 is heat welded at the SQR center 50.

When the rear end of the work 12 approaches the squeeze roll 16 as shown in FIG. 8, a limit switch (not shown) detects the rear end of the work 12,
The pinch rolls 13 and 14, which were pinching and transporting the workpiece 12, move in a direction away from the workpiece 12, and at the same time, the hydraulic cylinder 37 is operated and the energizing jig 46 is lowered to a position slightly lower than the upper surface of the workpiece 12. Next, a limit switch (not shown) detects that the energizing jig 46 has descended to a predetermined position, the hydraulic cylinder 45 is activated, and the energizing jig 46 follows the workpiece 12 at a faster speed than the workpiece 12, with the energizing pieces 49, 49' A touch sensor (not shown) detects that the tip of the energizing jig 46 has come into contact with the inner peripheral surface of the rear end of the work 12, and then the energizing jig 46 is raised several mm and at the same time moves the work 1 at the same speed as the work 12.
It is made to run together with 2. The workpiece 12 is sent out in this state, and the energizing chip 18 is turned on to the workpiece 1.
The current-carrying tip 18 is placed on the current-carrying pieces 49, 49' even when it is removed from the rear end of the workpiece 12, and as a result, the current-carrying chips 49, 49' remain on the current-carrying pieces 49, 49' until the rear end of the workpiece 12 comes to the SQR center 50. Electricity can be applied from the energizing chip 18 to the workpiece 12 via the energizing chip 18.
In other words, the same effect as when the welding auxiliary piece is welded to the rear end of the workpiece as explained in FIG. 3 can be obtained, and the rear end of the workpiece 12 can be completely welded. The rear end of the workpiece 12 is at the SQR center 50
When it reaches this point, the energizing jig 46 descends several mm and
2, the hydraulic cylinders 37 and 45 operate, and the energizing jig 46 returns to its original position, completing one cycle.

Next, workpiece 1 is smaller than workpiece 12.
2' (see Figure 5) will be explained. In this case, the hydraulic cylinder 29 is operated to lower the vertically movable table 28. Then, the vertical moving table 2
The energizing jig 46 is also attached to the energizing chip 8, and the energizing jig 46 also descends by the same amount as the energizing chip 18, so the relative positional relationship between the energizing chip 18 and the energizing jig 46 remains unchanged. There is no need to adjust the position again.

In addition, since the workpiece 12 may be misaligned in the gap (seam gap) between both side parts 17 due to bending during forming, etc., the resistance value of the welding current path should be made to be the same on both sides 17 to avoid deterioration of welding quality. There must be. Therefore, hydraulic cylinder 2
6 to move the horizontal moving table 25 in accordance with the seam gap, but at this time, since the energizing jig 46 is also attached to the horizontal moving table 25, the energizing jig 4
6 also moves at the same time, so there is no need to adjust the energizing jig 4 again when welding the rear end of the workpiece 12.
6 is the optimal position.

The same thing can be done by connecting the energizing chip 18 to the workpiece 1.
This also applies to the case where the vehicle is moved in the direction of movement in step 2. In order to optimize welding conditions, the distance between the SQR center 50 and the energizing tip 18 may be changed. In this case, the vertical moving table 22 may be moved in the advancing direction of the workpiece 12 by operating the hydraulic cylinder 23, but the energizing jig 46 also moves the vertical moving table 22.
Since it is attached to the energizing chip 18, the energizing jig 46 moves by the same amount as the moving amount of the energizing chip 18, and the energizing jig 46 is in the optimum position when welding the rear end of the workpiece 12.

As described above with reference to the embodiments and drawings, according to the present invention, it is possible to obtain the same effect as when welding an ERW pipe by welding a welding auxiliary piece to the material to be welded, and the following effects are obtained. . The labor and working time for welding the welding auxiliary piece are not required, and the cost is low because no material is required for the welding auxiliary piece. During welding work, spatters adhere to the roll, but there is no such inconvenience. In order to weld the welding auxiliary piece, it was necessary to stop the work line, but with the present invention, welding can be performed continuously without stopping. In addition, when the energizing chip is moved, the energizing jig is also moved by the same dimension in the same direction in which the energizing chip moves, so even when changing the pipe size, there is no need to adjust only the energizing jig anew. Furthermore, in the present invention, the energizing jig is provided above the tube and is set so as to catch up with the rear end of the tube during welding, so that even when set, it does not block the rear of the tube. This makes it possible to perform ERW pipe welding while using impeders, pipe rolls, etc.
Quality etc. can be improved.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams showing conventional ERW pipe welding, FIGS. 4 to 8 relate to an ERW pipe welding device according to the present invention, FIG. 4 is a front view, and FIG. 5 is an explanatory diagram showing conventional ERW pipe welding. A in Figure 4
-A arrow view, FIG. 6 is an enlarged perspective view of section B in FIG. 4, FIG. 7 is an enlarged view of section C in FIG. 5,
FIG. 8 is an overall perspective view. In the drawing, 12, 12' are workpieces, 13, 14,
15 is a pinch roll, 17 is a side part, 18 is an energizing chip, 37 and 45 are hydraulic cylinders, and 46 is an energizing jig.

Claims (1)

[Claims] 1. A feeding means provided on the bed and feeding out a material to be welded formed into a tubular shape with both sides of the plate member facing each other in the axial direction of the material to be welded, In the electric resistance welding tube welding apparatus, the electric current feeding tip is supported on a vertically movable table that is movable in the vertical direction above the bed. At the same time, the vertically movable table supports an energizing jig capable of energizing the welded material by contacting the rear end of the welded material and the energizing chip, and the energizing jig is placed within the line of the welded material. Alternatively, an electric resistance welding pipe welding apparatus characterized in that the vertically movable table is provided with a moving means for moving the material to be welded out of the line and a traveling means for moving the material to be welded in a sending direction.