JPH04300019A - Device for manufacturing electro-resistance-welded tube - Google Patents

Abstract

PURPOSE:To improve the dimensional accuracy and the quality of the welding zone of tube products by improving the accuracy of the plate thickness and of the edge shape of a metal strip which is provided for tubular forming. CONSTITUTION:In the manufacturing device 10 of the electro-resistance-welded tube, which is comprised of steel strip rolling device 11 and a roll forming device 12 by which a steel strip rolled by the strip rolling device 11 is formed into a tube, a steel strip edge rolling device 13 is arranged between the steel strip rolling device 11 and the roll forming device 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric resistance welded tube manufacturing apparatus.

0002

[Prior art] When manufacturing ERW steel pipes, the wall thickness of the steel strip,
Usually, it corresponds uniquely to the wall thickness of the product pipe. At this time, the steel strip is mainly a hot-rolled steel strip, and there are large variations in thickness accuracy in the width direction and longitudinal direction, which may affect the dimensional accuracy of the product pipe.

[0003] Conventionally, the electric resistance welded tube manufacturing apparatus described in Japanese Patent Publication No. 11663/1980 includes a metal strip rolling device and a roll forming device for forming the metal strip rolled by the metal strip rolling device into a tubular shape. This equipment guarantees the thickness accuracy of steel strips and improves the dimensional accuracy of product pipes.

0004

However, in small-diameter electric resistance welded steel pipes, a steel strip with slits in the width direction is used, but these slits cause sagging on the edge of the steel strip (see FIG. 5). This sagging of the edge of the steel strip obstructs the butt shape of the welded portion and causes defective welding or defective bead cutting.

[0005] The present invention improves the plate thickness accuracy and edge shape accuracy of the metal strip used for tubular forming, and improves the dimensional accuracy and
The purpose is to improve weld quality.

[0006]

[Means for Solving the Problems] The present invention as set forth in claim 1 comprises a metal strip rolling device and a roll forming device for forming the metal strip rolled by the metal strip rolling device into a tubular shape. In the electric resistance welded pipe manufacturing apparatus, a metal strip edge rolling device is disposed between the metal strip rolling device and the roll forming device.

The present invention according to claim 2 is the invention according to claim 1, further comprising: a metal strip light rolling device being disposed between the metal strip edge rolling device and the roll forming device. It is something.

[0008] The present invention according to claim 3 is the invention according to claim 1 or 2, further comprising the step of rolling the metal strip edge from the side that will be the outer surface of the tube to the side that will be the inner surface of the tube. It is equipped with a tapered roll that forms a sloped surface in the shape of an indentation.

[0009]

According to the present invention, the metal strip rolling device can ensure plate thickness accuracy, the metal strip edge rolling device can eliminate sagging of the metal strip edge, and improve edge shape accuracy.

0010

[Embodiment] Fig. 1 is a schematic diagram showing an ERW steel pipe manufacturing line according to an embodiment of the present invention, Fig. 2 is a front view showing a steel strip edge rolling device, and Fig. 3 is an end view showing a pipe butt shape. 4 is a schematic diagram showing another example of an electric resistance welded steel pipe manufacturing line, and FIG. 5 is a schematic diagram showing sagging of edges.

The electric resistance welded steel pipe manufacturing apparatus 10 shown in FIG. 1 includes a steel strip rolling device 11 and a steel strip 1 rolled by the steel strip rolling device 11.
The steel strip edge rolling device 13 is further disposed between the steel strip rolling device 11 and the roll forming device 12.

The steel strip rolling apparatus 11 has an entry tension device 14 and an exit tension device 15 to minimize changes in strip width during rolling, thereby rolling the steel strip 1 to a predetermined thickness. do.

The steel strip edge rolling device 13 includes one or more pairs of straight rolls 16 on the left and right as shown in FIG. 2(A), or one or more pairs of tapered rolls 17 on the right and left as shown in FIG. 2(B). It is used interchangeably and completely eliminates sag on the edge of the steel strip 1 rolled by the steel strip rolling device 11. The straight roll 16 and the tapered roll 17 are provided with flanges at both ends, the lower flange prevents the steel strip 1 from buckling in the sheet width direction, and the upper flange guides the steel strip 1 in the event of buckling.

At this time, the taper roll 17 in FIG. 2(B)
A sloped surface is formed on the edge of the steel strip 1 in the shape of an indentation from the side that will become the outer surface of the tube toward the side that will become the inner surface of the tube. 3 (A
) can form an I-shaped butt as shown in FIG. This I-shaped butt is shown in Fig. 3 (
Compared to the V-shaped butt as shown in B), welding quality,
Enables improved bead cutting performance.

The roll forming device 12 is a steel strip rolling device 11.
The steel strip 1 which has been rolled and edge-formed by the steel strip edge rolling device 13 is formed into a tubular shape by the forming rolls 18, and both edges of the raw tube are heated by a welding device (not shown), and then the steel strip 1 is rolled by the squeeze roll 19. The steel pipe 2 is joined by pressure.
form.

According to the electric resistance welded steel pipe manufacturing apparatus 10, the steel strip rolling device 11 ensures plate thickness accuracy, and the steel strip edge rolling device 13 eliminates sagging of the steel strip edge, thereby improving edge shape accuracy. Therefore, the steel strip 1 to be subjected to tubular forming
It is possible to improve plate thickness accuracy and edge shape accuracy, and improve the dimensional accuracy and welded part quality of product pipes.

The electric resistance welded steel pipe manufacturing apparatus 20 shown in FIG.
The reason lies solely in the placement of the . According to this steel strip light rolling device 21, in the steel strip edge rolling device 13, the dogbone-like bulge shape that occurs around the edge of the steel strip 1 can be lightly rolled down and flattened.

[0018] Hereinafter, concrete implementation results of the present invention will be explained.

(1) Pipe manufacturing specifications A steel pipe with an outer diameter of 50.8 mm and a wall thickness of 4.0 mm was manufactured using a steel strip having a plate width of 149.0 mm and a plate thickness of 4.2 mm.

(2) Equipment Specifications The rolling load of the steel strip rolling machine was set at a maximum of 100 tons, and tension control devices were installed on the input and output sides.

[0021] The rolling load of the steel strip edge rolling machine is up to 20
ton.

(3) Rolling Conditions The reduction ratio in the thickness direction in the steel strip rolling machine was set to 4.8%.

The edge reduction amount (on one side) in the steel strip edge rolling machine was set to 1.0 mm, and the edge rolling roll shape was a straight roll with flanges at both ends.

(4) Regarding the welding defect rate as a result of pipe manufacturing, compared to 5.3% in the conventional method, it was 0.5% in the method of the present invention using a steel strip edge rolling device.
I was able to improve it.

Regarding the internal bead defect rate, the conventional method
．． 5%, it could be improved to 0.5% by the method of the present invention using a steel strip edge rolling machine.

[0026]

[Effects of the Invention] As described above, according to the present invention, it is possible to improve the plate thickness accuracy and edge shape accuracy of the metal strip used for tubular forming, and improve the dimensional accuracy and welded part quality of the product tube. .

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an electric resistance welded steel pipe production line according to an embodiment of the present invention.

FIG. 2 is a front view showing a steel strip edge rolling device.

FIG. 3 is an end view showing a tube butting shape.

FIG. 4 is a schematic diagram showing another example of an ERW steel pipe production line.

FIG. 5 is a schematic diagram showing edge sag.

[Explanation of symbols]

10 ERW steel pipe manufacturing equipment 11 Steel strip rolling equipment 12 Roll forming equipment 13 Steel strip edge rolling equipment 20 ERW steel pipe manufacturing equipment 21　Steel strip light rolling device

Claims (3)

[Claims] 1. An electric resistance welded tube manufacturing apparatus comprising a metal strip rolling device and a roll forming device for forming a metal strip rolled by the metal strip rolling device into a tubular shape. 1. An electric resistance welded pipe manufacturing apparatus characterized in that a metal band edge rolling device is disposed between a roll forming device and a metal band edge rolling device. 2. The electric resistance welded pipe manufacturing apparatus according to claim 1, wherein a metal band light rolling device is disposed between the metal band edge rolling device and the roll forming device. 3. The metal strip edge rolling device includes a tapered roll that forms an indented slope surface on the metal strip edge from the side that will become the outer surface of the tube toward the side that will become the inner surface of the tube. Or the electric resistance welded pipe manufacturing apparatus according to 2.