JP2019081232A - Method and apparatus for manufacturing steel pipe - Google Patents

Abstract

To provide a method for manufacturing steel pipes, in which cutting chips adhering to a pipe end inner surface are removed without deteriorating productivity, and which suppresses generation of push-in flaws on the pipe end inner surface.SOLUTION: In a method for manufacturing steel pipes 1, when aligning and conveying cut steel pipes 1 to a pipe end shape correction device using an aligning roll 2, cutting chips 4 adhering to a pipe end inner surface are brought into contact with cutting chips removal means 3, while the steel pipes 1 are rotated by the aligning roll 2, in order to remove the cutting chips 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and an apparatus for manufacturing a steel pipe.

  A steel pipe is generally manufactured by forming a steel strip and cutting it to a predetermined length to correct the shape of the pipe end. Further, the shape correction of the pipe end is generally performed by pushing the plug rotated from the pipe end to a predetermined position in a fixed state of the steel pipe (e.g., Patent Document 1).

In the process of manufacturing a steel pipe as described above, when cutting the steel pipe, cuttings of rice grain size may adhere to the inner surface of the pipe end. If the shape correction of the pipe end is carried out without removing such chips, a pushing crease due to the chips may be generated on the inner surface of the pipe end.
Since the generation of swarf depends on various factors such as cutting conditions, the state of the cutting blade, and the material of the steel pipe, it is practical to prevent the generation of swarf by controlling the conditions of the existing cutting device etc. Difficult to
On the other hand, air blow, vacuum suction, washing with water, etc. are known as a method of removing chips and the like adhering to the inner surface of the pipe end due to chamfering, and a method of bringing a brush into contact with the inner surface , Patent Document 2).

WO 2007/114176 Japanese Utility Model Application Publication No. 63-27239

However, if the above method using air blow or the like is adopted to remove cutting debris attached to the inner surface of the pipe end by cutting the steel pipe, it is necessary to newly add a process for performing the method. There is a problem that the productivity of
The present invention has been made to solve the above-described problems, and removes chips attached to the inner surface of the pipe end without reducing the productivity, thereby suppressing the generation of the pressure drop in the inner surface of the pipe end. It is an object of the present invention to provide a method and an apparatus for manufacturing a steel pipe that can be used.

  The inventors of the present invention conducted intensive studies to solve the above problems, and as a result, the aligned steel roll is rotated by the aligning roll when the cut steel pipe is aligned and transported to the pipe end shape correction device by the aligning roll. The inventors have found that the swarf can be efficiently removed by bringing the swarf adhering to the inner surface of the tube into contact with the swarf removing means, and the present invention has been accomplished.

  That is, according to the present invention, when the cut steel pipe is aligned and conveyed to the pipe end shape correction device by the aligning roll, the cutting scrap adhering to the inner surface of the pipe end is removed while rotating the steel pipe by the aligning roll. It is a manufacturing method of a steel pipe which contacts with a means and removes the said scrap.

Further, according to the present invention, there are provided a cutting device, a pipe end shape correcting device, an aligning roll for aligning and conveying a steel pipe from the cutting device to the pipe end shape correcting device, and cutting debris attached to the inner surface of the pipe end during the alignment and conveying. And an apparatus for producing a steel pipe, which has a scrap removal means capable of coming into contact therewith.

  According to the present invention, there is provided a method and an apparatus for manufacturing a steel pipe capable of removing swarf attached to the inner surface of the pipe end without reducing the productivity and suppressing the generation of the pressure drop in the inner surface of the pipe end. be able to.

It is a top view which shows the state which is carrying out alignment conveyance of the steel pipe cut | disconnected by the cutting device to a pipe end shape correction apparatus by an aligning roll. It is sectional drawing which shows the state when the swarf adhering to the tube end inner surface and swarf removal means contact. It is a perspective view which shows the state which provided the swarf removal means in the surface where a pipe end aligns.

The method for manufacturing a steel pipe according to the present invention cuts off chips attached to the inner surface of the pipe end while rotating the steel pipe by the aligning roll when the cut steel pipe is aligned and transported to the pipe end shape correction device by the aligning roll. Contact with debris removal means to remove debris.
The apparatus for manufacturing a steel pipe according to the present invention further includes a cutting device, a pipe end shape correcting device, an aligning roll for aligning and conveying the steel pipe from the cutting device to the pipe end shape correcting device, and It has swarf removal means which can be in contact with swarf.

Hereinafter, preferred embodiments of the method and apparatus for manufacturing a steel pipe according to the present invention will be described with reference to the drawings.
FIG. 1 is a top view showing a state in which a steel pipe cut by a cutting device is aligned and conveyed to a pipe end shape correction device by an aligning roll.
The steel pipe 1 cut by the cutting device is aligned and conveyed by the aligning roll 2 to the pipe end shape straightening device.
The aligning roll 2 has a function of conveying the steel pipe 1 to the pipe end shape correction device while aligning the ends (also referred to as “pipe ends”) of the steel pipe 1 by its rotation. The diameter and the number of the aligning rolls 2 may be appropriately adjusted according to various conditions such as the distance from the cutting device to the pipe end shape correcting device, and are not particularly limited.

The steel pipe 1 aligned and conveyed by the aligning roll 2 is rotated by the aligning roll 2. At this time, by bringing the swarf adhering to the inner surface of the pipe end into contact with the swarf removing means 3, the swarf in contact with the swarf removing means 3 is scraped off by the rotation of the steel pipe 1.
Here, FIG. 2 shows a cross-sectional view showing a state in which the swarf adhering to the inner surface of the tube end and the swarf removing means 3 are in contact with each other.
The scraps 4 attached to the inner surface of the pipe end are difficult to remove simply by contacting with the scrap removal means 3, but the scraps attached to the inner surface of the pipe end by using the rotation of the steel pipe 1 by the aligning roll 2 4 can be made easy to peel off. Further, since the rotation of the steel pipe 1 by the aligning roll 2 is used, a driving mechanism or the like is not required for the swarf removing means 3 and the introduction cost of the swarf removing means 3 can also be suppressed.

  The installation site of the swarf removal means 3 is not particularly limited, but is preferably provided on the surface where the pipe end (the cut surface of the steel pipe 1) is aligned by the aligning roll 2 as shown in FIG. 1. Here, as an example, FIG. 3 shows a perspective view showing a state in which the swarf removal means 3 is provided on the surface 5 on which the tube ends are aligned. By providing the swarf removing means 3 at such a position, it is possible to use the swarf removing means 3 having a simple structure, so there is no need to significantly improve the existing manufacturing apparatus.

  The swarf removing means 3 is not particularly limited as long as it has a structure capable of coming into contact with the swarf 4 attached to the inner surface of the tube end. Specifically, the swarf removing means is preferably a member having a convex portion capable of invading the inside of the tube end. Examples of such a member include a member having a saw-like convex portion, a brush and the like, and among them, a member having a saw-like convex portion is preferable from the viewpoint of durability. Moreover, it is preferable that the member which has a saw-shaped convex part is formed from various metals, such as iron, stainless steel, and an alloy, from a durable viewpoint.

  There is no particular limitation on the shape of individual convex portions in a member having a saw-like convex portion, and other than the triangular plate shape as shown in FIGS. 1 to 3, it may be triangular pyramidal, semicircular, semiconical, etc. It can be in various shapes. Among these, it is preferable that the shape of each convex part is a triangular plate shape from a viewpoint of workability. If each protrusion is in the form of a triangular plate, the peeled off chips 4 can be easily removed to the outside of the steel pipe 1.

  The size of the individual convex portions may be appropriately adjusted according to the shape of the individual convex portions, the inner diameter of the steel pipe 1 and the like, and is not particularly limited. For example, when each protrusion is a triangular plate, the width of each protrusion is preferably smaller than the inner diameter of the steel pipe 1, and more preferably about half of the inner diameter of the steel pipe 1. The height of each protrusion may be about half of the width of each protrusion, and the thickness of each protrusion may be about 1 to 10 mm. By using the chip removing means 3 having such a saw-like convex portion, the chip 4 attached to the inner surface of the tube end can be stably removed.

  The length of the area where the convex portion is formed is not particularly limited because it depends on the length of the area to be aligned and transported by the aligning roll, but it is generally 100 mm to 1000 mm, more preferably 200 mm to 500 mm.

  In addition, since the manufacturing method and manufacturing apparatus of the steel pipe 1 of this invention have the main characteristics in the area | region which carries out the alignment conveyance of the steel pipe 1 between a cutting device and a pipe end shape correction device, other area | regions (for example, cutting device) And the tube end shape correction device etc. are not particularly limited, and those known in the art can be used.

  The method and apparatus for manufacturing the steel pipe 1 according to the present invention rotates the steel pipe 1 by the aligning roll 2 when the steel pipe 1 cut by the cutting device is aligned and transported by the aligning roll 2 to the pipe end shape correction device. The scrap 4 can be removed mechanically by bringing the scrap 4 adhering to the inner end of the tube into contact with the scrap removal means 3. Therefore, it is not necessary to add a new process for removing the cuttings 4 adhering to the inner surface of the pipe end, and the generation of the pressure drop in the inner surface of the pipe end can be suppressed without reducing the productivity of the steel pipe 1 It becomes.

  Hereinafter, the present invention will be described in detail by way of Examples and Comparative Examples, but the present invention is not construed as being limited thereto.

Example 1
After the steel strip is formed, it is cut to a predetermined length by a cutting device, aligned and conveyed to the pipe end shape correction device by an aligning roll to carry out shape correction of the pipe end, and the inner diameter is 38.1 to 57.2 mm Of steel pipes (52, 151) were manufactured. Here, the alignment conveyance was performed by providing a chip removing means 3 having a saw-like convex portion as shown in FIG. 3 on the surface where the tube ends are aligned. The detailed shape of the chips removal means is as follows.
Shape of convex part: Triangle plate shape Height of convex part: 25 mm
Convex part width: 12.5 mm
Thickness of convex part: 3 mm
Length of area where convex part is formed: 320 mm

(Example 2)
The process was carried out in the same manner as Example 1 except that the shape of the scrap removal means was changed as follows and that a steel pipe (11,812) having an inner diameter of 60.5 to 76.3 mm was produced.
Shape of convex part: triangle plate-like convex part height: 40 mm
Width of convex part: 20 mm
Thickness of convex part: 3 mm
Length of area where convex part is formed: 320 mm

(Comparative example 1)
A steel pipe (34, 883) having an inner diameter of 38.1 to 57.2 mm was produced in the same manner as in Example 1 except that the scrap removing means was not provided.
(Comparative example 2)
A steel pipe (10, 966) having an inner diameter of 60.5 to 76.3 mm was produced in the same manner as in Example 2 except that the scrap removing means was not provided.

  About the steel pipe manufactured by said Example and comparative example, the presence or absence of generation | occurrence | production of the pressure drop in the pipe end inner surface was observed visually, and the number of steel tubes which the pressure drop generate | occur | produced in the pipe end inner surface was calculated | required. The results are shown in Table 1.

As shown in Table 1, in Examples 1 and 2, no indentations were generated on the inner surface of the steel pipe, whereas in Comparative Examples 1 and 2, indentations were generated on the inner surface of the steel pipe.
As can be seen from the above results, according to the present invention, it is possible to remove the chips attached to the inner surface of the pipe end without reducing the productivity, and to suppress the generation of the pressure drop in the inner surface of the pipe end. A manufacturing method and apparatus can be provided.

1 steel pipe 2 aligning roll 3 scrap removing means 4 scraps 5 surface where the pipe ends are aligned

Claims (8)

  When the cut steel pipe is aligned and transported to the pipe end shape correction device by the aligning roll, the cutting scrap attached to the inner surface of the pipe end is brought into contact with the scrap removing means while rotating the steel pipe by the aligning roll. The manufacturing method of a steel pipe which removes the said cutting waste.   The manufacturing method of the steel pipe of Claim 1 in which the said swarf removal means is provided in the surface where the said pipe end aligns with the said aligning roll.   The manufacturing method of the steel pipe of Claim 1 or 2 which is a member which has the convex part which the said cuttings removal means can penetrate | invade inside the said tube end.   The manufacturing method of the steel pipe of Claim 3 whose said convex part is sawtooth shape.   A cutting device, a pipe end shape correcting device, an aligning roll for aligning and conveying a steel pipe from the cutting device to the pipe end shape correcting device, and a cutting waste capable of contacting with cutting waste adhering to the inner surface of the pipe end during the alignment and transfer The manufacturing apparatus of a steel pipe which has a removal means.   The apparatus for manufacturing a steel pipe according to claim 5, wherein the chip removing means is provided on the surface where the pipe ends are aligned by the aligning roll.   The manufacturing apparatus of the steel pipe of Claim 5 or 6 whose said chip | tip removal means is a member which has a convex part which can penetrate | invade inside the said tube end.   The manufacturing apparatus of the steel pipe of Claim 7 whose said convex part is sawtooth shape.