JP3230290B2 - High frequency ERW pipe welding equipment - Google Patents

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 an improvement in a bead cutting portion of an electric resistance welded pipe outer surface.

[0002]

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

In this apparatus, a work coil 3 heats both edges 2a of a tube material 2 bent and formed into a pipe shape by a forming roll section 1, and presses and joins the edges to each other with a ceramic squeeze roll 4. Build body 2. Pipe 2 sent out from squeeze roll 4
Cuts the bead 5 raised on the outer surface of the welded portion continuously with a cutting tool 6. The pipe 2 from which the beads 5 have been removed in this way is cooled to room temperature by the cooling device 7 with the heat applied for welding, and sent to the next sizing step.

[0004]

In the conventional apparatus as described above, when forming a thin-walled tube, the pipe material is made of a bite compared to 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 apparatus must have a sharp cutting edge in order to improve the machinability.

In addition, 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 apparatus, since the welding point of the pipe 2 and the cutting point of the cutting tool 6 are separated only by several tens of centimeters, the residual welding heat at the cutting point of the cutting tool is high. As the temperature becomes high, the cutting edge is easily formed on the cutting tool 6. For this reason, the conventional device has a problem that the cutting performance of the cutting tool is poor and the service life of the cutting tool 6 is short.

In addition, since the cutting operation is performed with the cutting tool 6 immediately after the welding operation of the pipe 2, spatters and the like at the time of welding are entangled in the cutting edge of the cutting tool 6 and the transport rolls, and are formed on the cutting surface and the pipe surface. There has been a problem that the surface of the pipe becomes messy because dents and scratches are left.

Further, when the tube material 2 is induction-heated by the work coil 3, in addition to the main current flowing in both edges 2a as shown by the solid line in FIG. appear. Since the ceramic squeeze roll 4 is used in the apparatus of this embodiment, the high-frequency leak current flows through a short circuit from the pipe to the ground through the cutting tool 6 around the work coil 3 as shown by the broken line in FIG. Since the tube material is a good conductor metal material such as brass, aluminum, copper or the like as compared with general iron, high-frequency leakage current flows more easily. Therefore, when cutting the bead 5 of the tube body 2 with the cutting tool 6, there is a problem that discharge chipping occurs and causes an obstacle.

In view of the above, the present invention provides a high-frequency electric resistance welded tube having improved cutting performance of a cutting tool, a long service life of the cutting tool, a clean cutting surface, and no trouble caused by electric discharge chipping of the cutting tool. It is intended to provide a new welding device.

[0010]

According to the high frequency electric resistance welded pipe welding apparatus of the present invention, a cooling water is provided between a squeeze roll position on a pipe passage during pipe making and a bead cutting bit position on an outer surface of the pipe. And a cooling washing tank using both air and air, and a ferrite core that allows a tube to pass through a hollow portion of the ring body is installed in the cooling washing tank.

[0011]

With the construction described above, the magnetic flux generated by the high-frequency leak current flowing through the short circuit from the cutting tool through the ground to the pipe is linked to the ferrite core to generate a high-frequency leak current and a reverse current. . This increases the impedance of the tube and reduces the high-frequency leakage current, thereby eliminating discharge chipping of the cutting tool. Further, since the residual heat of the welded portion of the tube is cooled in the cooling / cleaning tank, even if the tube is formed of a material such as brass, aluminum, or copper, the cutting property of the cutting tool can be greatly improved. . Furthermore, dents and scratches on the pipe surface can be eliminated by removing spatters and the like adhering to the pipe surface with cooling water and air.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the high-frequency electric resistance welded pipe welding apparatus according to the present invention will be described below with reference to FIGS. In FIG.
Parts corresponding to the above-described 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 a schematic configuration of the apparatus of this example, 1 is a forming roll portion, 2 is a tube, 2a is an edge, 3 is a work coil, 4 is a squeeze roll, 5 is an external bead, 6 is a bite, and 7 is a conventional The cooling device 8 is a cooling washing tank of the present invention.

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

As shown in FIG. 2, the cooling / cleaning tank 8 includes a cylinder 10 integrated with the mounting base 9 and a ferrite core 12 fixed by a core fixing ring 11 at a central portion inside the cylinder 10. A lid 13 provided with a passage hole for the pipe body is attached to the inlet side of the pipe body 2, and a boiler 14 for draining the water and a drain lid 15 are attached to the outlet side of the pipe 2. It is a tank. The cooling washing tank 8 is filled with cooling water introduced from a cooling water nozzle
In addition to cooling the ferrite core 12, spatters attached to the tube 2 during welding by high-frequency induction heating are washed away, and are washed and removed by an air nozzle 17 arranged on the outlet side.

As shown in FIG. 2, two ferrite iron cores 12 are arranged in the cooling and washing tank 8 in this embodiment.
The ferrite core 12 is an annular high-frequency ferrite core, which is formed so as to pass through the tube 2 through the hollow portion of the annular body. The ferrite core 12 constitutes a kind of current limiting reactor by increasing a part of the tube 2 passing therethrough to increase the impedance of the tube 2. That is, the ferrite core 12 increases the conductive closed circuit impedance, reduces the high-frequency leakage current flowing from the cutting tool 6 through the short circuit through the ground through the cutting tool 6 generated at the time of induction heating, and eliminates the discharge chipping of the cutting tool 6. Looking at the action of the ferrite core 12, the tube 2
Magnetic flux generated by high-frequency leakage current
2 to generate a leak current and a reverse current. Thereby, the impedance of the ferrite core 12 insertion portion of the tube 2 is increased, and the leak current is reduced. Further, since the increase in the impedance of the tube 2 is substantially proportional to the length of the ferrite core 12, the tube 2
The high frequency leakage current flowing through the ferrite core 12 decreases in substantially inverse proportion to the number (length) of the ferrite cores 12. The ferrite core 12 used as described above is heated during use,
It is cooled together with the tube 2 in the cooling and washing tank 8.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various other configurations can be adopted without departing from the spirit of the present invention.

[0017]

As described above in detail, according to the high-frequency electric resistance welded pipe welding apparatus of the present invention, the position between the position of the squeeze roll on the pipe passage during pipe formation and the position of the bead cutting tool on the outer surface of the pipe is formed. A cooling washing tank is installed in the cooling washing tank, and a ferrite core is installed in the cooling washing tank so that the tube passes through the hollow part of the ring. The magnetic flux generated by the leak current flowing through the ferrite core is linked to the ferrite core, thereby generating a leak current and a reverse current. This has the effect of increasing the impedance of the tube and reducing the leakage current, thereby eliminating the discharge chipping of the cutting tool.

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

Further, spatters and the like at the welded portions of the pipes are washed away in the cooling washing tank before bead cutting, and spatters can be removed by an air nozzle provided on the exit side of the cooling washing tank. This has the effect of preventing dents, scratches, and the like from being formed.

Further, if cooling is performed by the next cooling device after cooling in the cooling washing tank, there is an effect that the cooling of the pipe during pipe forming can be improved and the deformation distortion in the sizing step can be improved.

[Brief description of the drawings]

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

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

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

[Explanation of symbols]

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

Claims (1)

(57) [Claims] 1. A high-frequency electric resistance welded tube welding apparatus in which both edges of a tube material are induction-heated, the two edges are pressure-welded with a squeeze roll, and a bead on the outer surface of the weld is cut with a cutting tool. A cooling washing tank having a cooling function and a washing function such as spattering is installed at a position between the squeeze roll position on the body passage and the bite position. In the cooling washing tank, the pipe is inserted into a hollow portion of a ring body. A high-frequency electric resistance welded tube welding device, comprising: a ferrite core through which a body passes, and configured to prevent a leak current flowing through the tube.