JPH0679475A - High frequency electric welded tube welding equipment - Google Patents

Abstract

PURPOSE:To prevent a fault caused by discharge chipping of a cutting tool by providing a cooling washing tank between a squeeze roll and the cutting tool, providing an annular ferrite iron core in this tank and allowing a tube body to pass through its hollow part. CONSTITUTION:A cooling washing tank 8 is arranged between a squeeze roll 4 and a cutting tool 6 on a moving path of a tube body 2. In the inside of the cooling washing tank 8, a ferrute iron core is arranged. The ferrite iron core is an annular high frequency ferrite core, and the tube body 2 is allowed to pass through a hollow part of its annular body. The ferrite iron core constitutes a kind of current limiting reactor together with a part of the passing tube body 2, and an impedance of the tube body 2 is increased. By this ferrite iron core, a conductive closed circuit impedance is raised, and a high frequency leak current flowing through a short circuit through an earth from the cutting tool 6 generated at the time of induction heating is reduced. Accordingly, discharge chipping of the cutting tool 6 is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency electric resistance welded pipe welding apparatus, and more particularly to improvement of a bead cutting portion on the outer surface of the electric resistance welded pipe.

[0002]

2. Description of the Related Art Conventionally, a high-frequency electric resistance welded pipe welding apparatus as schematically illustrated in FIG. 3 has been used as a thin-walled tube forming equipment made of brass, aluminum or copper used for a radiator tube or the like.

In this apparatus, both edges 2a of a tubular material 2 bent and formed into a pipe shape by a forming roll section 1 are heated red by a work coil 3 and a squeeze roll 4 made of ceramics press-bonds the edges to each other. Produce body 2. Tube 2 sent out from squeeze roll 4
Continuously cuts the bead 5 rising on the outer surface of the welded portion with a cutting tool 6. The tube body 2 from which the bead 5 has been removed in this way is cooled by the cooling device 7 to room temperature by the heat applied for welding, and then sent to the next sizing step.

[0004]

In the conventional apparatus as described above, when a thin-walled tube is produced, the pipe material is a bite as compared with iron such as brass (BS), aluminum (Al), or copper (Cu). Use a material with poor machinability. For this reason, the cutting tool 6 used in the conventional device must have a sharp cutting edge in order to improve the cutting performance.

Moreover, the cutting speed of the cutting tool 6 is as high as 120 m / min, which is the same as the pipe forming speed.

Further, in the conventional device, since the welding point of the pipe 2 and the cutting point of the cutting tool 6 are separated from each other by only several tens of centimeters, the residual heat of welding at the cutting point of the cutting tool is high, so that the material temperature at the time of cutting by the cutting tool 6 is high. The temperature is high, and it is a condition that the cutting edge is likely to be formed on the cutting tool 6. For this reason, the conventional device has a problem that the cutting property of the cutting tool is poor and the working life of the cutting tool 6 is short.

In addition, since the cutting work is performed with the cutting tool 6 immediately after the welding work of the pipe body 2, at this time, spatter and the like at the time of welding are caught in the cutting edge of the cutting tool 6 and the transfer roll and the like on the cutting surface and the pipe surface. Since dents and scratches are left, there is a problem that the surface properties of the pipe become unusable.

Further, when the tube material 2 is induction-heated by the work coil 3, in addition to the main current flowing in both edge portions 2a as shown by the solid line in FIG. Occur. Since this high frequency leak current uses the ceramic squeeze roll 4 in the apparatus of this embodiment, as shown by the broken line in FIG. 3, the high frequency leak current flows from the tubular body through the bite 6 to the ground through the work coil 3 as a center. Since the tube material is a good conductor metal material such as brass, aluminum, and copper, high-frequency leak current is easier to flow. Therefore, when cutting the bead 5 of the tubular body 2 with the cutting tool 6, there is a problem that discharge chipping occurs and causes a trouble.

In view of the above points, the present invention has a high-frequency electric resistance welded pipe having a good cutting property of the cutting tool, a long working life of the cutting tool, a clean cutting surface, and no trouble caused by the discharge chipping of the cutting tool. The purpose is to newly provide a welding device.

[0010]

A high frequency electric resistance welded pipe welding apparatus according to the present invention is provided with a cooling water between a squeeze roll position on a pipe passage during pipe making and a bead cutting bite arrangement position on the outer face of the pipe. , And a cooling and washing tank that also uses air are installed, and in this cooling and washing tank, a ferrite core that allows the tubular body to pass through the hollow portion of the ring is installed.

[0011]

With the above-described structure, the magnetic flux generated by the high frequency leak current flowing from the bite to the short circuit via the ground in the tube is linked to the ferrite core to generate the high frequency leak current and the reverse current. . This increases the impedance of the tube body and reduces the high frequency leak current, so that the discharge chipping of the bite can be eliminated. Further, since the residual heat of the welded portion of the pipe is cooled in the cooling and washing tank, the machinability of the cutting tool can be greatly improved even if the pipe is made of a material such as brass, aluminum or copper. . Further, by removing spatter and the like adhering to the surface of the pipe body with cooling water and air, it is possible to eliminate dents and scratches on the pipe surface.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the high frequency electric resistance welded pipe welding apparatus of the present invention will be described below with reference to FIGS. In Figure 1,
Portions corresponding to the above-mentioned conventional example shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, which shows the schematic configuration of the apparatus of this example, 1 is a forming roll part, 2 is a tubular body, 2a is an edge, 3 is a work coil, 4 is a squeeze roll, 5 is an outer bead, 6 is a bite, and 7 is a conventional one. The cooling device 8 is the cooling and washing tank of the present invention.

The cooling and washing tank 8 is arranged at a position between the squeeze roll 4 on the moving path of the pipe body 2 and the cutting tool 6 of the outer bead 5.

As shown in FIG. 2, the cooling and washing tank 8 has a cylinder 10 integrated with a mounting base 9, and a ferrite core 12 fixed by a core fixing ring 11 at the center of the inside of the cylinder 10. A lid 13 provided with a passage hole for the tubular body is attached to the inlet side of the tubular body 2, and an outlet side is made to pass through the tubular body 2 to which a drain 14 and a drain lid 15 for draining are attached to pass through. It is a tank. The cooling and washing tank 8 is provided with the cooling water introduced from the cooling water nozzle 16 for the pipe body 2,
The ferrite core 12 is cooled, spatter debris attached to the tube body 2 is washed away during welding by high frequency induction heating, and is washed and removed by the air nozzle 17 arranged on the outlet side.

In the cooling and washing tank 8, as shown in FIG. 2, two ferrite iron cores 12 are arranged in this example.
The ferrite core 12 is an annular high frequency ferrite core, and is configured to pass through the tubular body 2 through the hollow portion of the annular body. The ferrite core 12 forms a kind of current limiting reactor by being mixed with a part of the tube body 2 that passes through it, and increases the impedance of the tube body 2. That is, the ferrite core 12 raises the impedance of the conductive closed circuit, reduces the high frequency leak current flowing from the cutting tool 6 through the short circuit through the ground during induction heating, and eliminates the discharge chipping of the cutting tool 6. Looking at the action of the ferrite core 12, the tubular body 2
The magnetic flux generated by the high frequency leakage current is applied to the ferrite core 1
2 is linked to generate a leak current and a reverse current. As a result, the impedance of the ferrite core 12 insertion portion of the tubular body 2 is increased and the leak current is reduced. Furthermore, since the increase in impedance of the tubular body 2 is approximately proportional to the length of the ferrite core 12, the tubular body 2
The high-frequency leakage current flowing through the core decreases in inverse proportion to the number (length) of the ferrite cores 12. Further, although the ferrite core 12 used as described above is heated during use,
It is cooled together with the tubular body 2 in the cooling and washing tank 8.

The present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0017]

As described in detail above, according to the high frequency electric resistance welded pipe welding apparatus of the present invention, the position between the squeeze roll position on the pipe passage during pipe making and the bead cutting bite position on the outer face of the pipe is arranged. In addition, a cooling and washing tank is installed in the cooling and washing tank, and a ferrite iron core that allows the pipe to pass through the hollow part of the annulus is installed in the cooling and washing bath. The magnetic flux generated by the leak current flowing through the ferrite core is linked to the magnetic flux to generate a leak current and a reverse current. As a result, the impedance of the tube is increased and the leak current is reduced, so that the discharge chipping of the bite can be eliminated.

Further, since the residual heat of the welded portion of the pipe body is cooled in the cooling / cleaning tank, the machinability of the cutting tool can be greatly improved even if the pipe body is made of a material such as brass, aluminum or copper. There is an effect. Furthermore, the wound core that has generated heat in the cooling and washing tank can be cooled together with the tubular body, eliminating the need for a dedicated cooling device for the wound core. In addition, since the cutting property of the cutting tool is improved, the surface properties of the tubular body are improved, the cutting surface can be finished neatly, and the service life of the cutting tool can be improved.

Further, spatters and the like on the welded pipe can be washed away before bead cutting in the cooling and washing tank described above, and spatters can be removed by the air nozzle provided on the outlet side of the cooling and washing tank. This has the effect of preventing dents and scratches due to jamming.

Further, after cooling in the cooling and washing tank, cooling in the next cooling device has the effect of favorably cooling the tubular body during pipe making and improving the deformation strain in the sizing step.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of essential parts showing an embodiment of a high frequency electric resistance welded pipe welding apparatus of the present invention.

FIG. 2 is a front view of a main part of the above embodiment.

FIG. 3 is a schematic explanatory diagram of a main part illustrating a conventional high frequency electric resistance welded pipe welding apparatus.

[Explanation of symbols]

 1 ... Forming roll part 2 ... Tube body 2a ... Edge 4 ... Squeeze roll 5 ... Bead 6 ... Bit 8 ... Cooling and washing tank 10 ... Cylinder 11 ... Core fixing ring 12 ... Ferrite core 16 ... Cooling water nozzle 17 ... Air nozzle

Claims (1)

[Claims] 1. A high-frequency electric resistance welded pipe welding apparatus in which both edges of a tubular material are induction-heated, the both edges are pressure-welded with a squeeze roll, and the bead on the outer surface of the welded portion is cut with a cutting tool. A cooling cleaning tank having a cooling function and a cleaning function such as spatter is installed between the squeeze roll position and the bite position on the body passage, and the pipe is provided in the hollow portion of the ring in the cooling cleaning tank. A high frequency electric resistance welded pipe welding apparatus, characterized in that a ferrite core adapted to pass through the body is provided to prevent a leak current flowing through the tubular body.