JPS60257924A - Method and device for producing square pipe - Google Patents

Abstract

PURPOSE:To decrease the number and kind of the rolls required for forming a base pipe and to reduce an equipment cost by forming a belt-like blank material into the base pipe having an oval shape or elliptical section and forming the base pipe into a square pipe. CONSTITUTION:The belt-like blank material is formed into the tubular shape having gradually curved parts on both sides during the time when said material passes through breakdown rolls and arrives at fin pass rolls 20. The side rolls 24, 25 of the rolls 20 are formed with the oval or elliptical caliber by approximately short circular cylindrical auxiliary rolls 26, 27 interposed therebetween and the upper and lower rolls 21, 23 thereof are rolls having a round caliber and therefore the blank material is formed to the tubular shape having the oval or elliptical shape. The butt ends thereof are then subjected to seam welding to form the base pipe having the oval or elliptical section. Such base pipe is passed through square shape forming rolls, by which the base pipe is formed into the square pipe. The device is made adaptable to the formation of plural sizes of the base pipes by increasing or decreasing the rolls 26, 27 and the reduction in the number and kind of the rolls required in the process for forming the base pipe are decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for manufacturing a rectangular tube having a square or rectangular cross section, and an apparatus for carrying out the method.
In particular, the present invention relates to a method and apparatus for manufacturing rectangular tubes using a roll forming method.

Among the conventional manufacturing methods for rectangular tubes, the roll forming method involves passing a metal strip material, such as steel strip, through a multi-stage group of rolls to create a mother tube, and then forming the mother tube into a rectangular shape. This is a method of forming (fixing) the cross section.To briefly explain this based on the drawings, in Fig. 5, the coil 1
The steel strip 2 fed out from the belt passes through an uncoiler, a leveler, etc. (not shown), and then is sent to a series of breakdown rolls 3 at the first stage. Steel strip 2, which originally had a flat cross section
Figure 5 (B) while passing breakdown roll 3
As shown in the figure, both sides are gradually curved toward the top side.
The fin pass roll 4 in the next stage is formed to have a round cross section, and the angle control and centering of the side edge surface (edge surface) are performed by the fin plate of the upper roll. The band r#2 thus formed with a round cross section is welded by a resistance welder 6 while controlling the butt shape of the side edges (edges) by a squeeze roll 5, and then bead cut by a bead cutter 7. The main pipe 8 has a round cross section. The size of the main tube 8 is corrected using sizing rolls 9 while forming it, and finally it is formed into a rectangular tube 11 using Turk's head rolls 10.

Problems to be Solved by the Invention However, when manufacturing a rectangular tube by the above-mentioned roll forming method, conventionally, the steel strip 2 is formed into a round cross section in the forming process leading to the breakdown roll 3 and the fin pass roll 4. However, since the main tube 8 was a round tube, there were problems described below.

That is, FIG. 6 is a diagram showing an example of a conventionally used fin pass roll 4. As shown here, an upper roll 4a having a fin plate 12, a lower roll 4b arranged parallel to this, and left and right rolls 4a are shown. side roll 4c,
4d, but these rolls 4a to 4
d is a drum-shaped roll whose caliber is circular in order to perform fire forming. By the way, the curvature of the outer circumference of a circle is determined by its radius, so when changing the size of the round tube that is the main tube 8 depending on the size of the square tube 11 to be manufactured, the curvature of the outer circumference will depend on the radius. Therefore, it is necessary to use a fin pass roll 4 with a hole type that matches the change. Therefore, in a series of pipe-making lines using the roll-forming method, pipes of several sizes are usually manufactured, so it is necessary to prepare fire-forming rolls for each size, and the number of rolls to be prepared for this is limited. 3- Since the number of rolls increases considerably, there is a problem that equipment costs increase and running costs rise due to roll wear.

In addition, square pipes made by the roll forming method are
In addition to those with a square cross section, there are also cases with a rectangular cross section, but rectangular tubes with a rectangular cross section have so-called anisotropy. Not only is it necessary to increase the output, but also the roll stand for square forming cannot increase the amount of rolling formed per machine.
There was a problem in that the number of roll stands had to be increased, resulting in an increase in the size of the equipment and an increase in equipment costs.

Means for Solving the Problems In view of the above circumstances, the present invention involves forming a material such as a steel band into an oval-shaped tube or an oval-shaped tube, and then manufacturing a rectangular tube by using this as a mother tube and performing square forming. In order to implement the method and direction, one of the rolls in the process of forming the material into a pipe, which applies pressure from both the left and right sides of the pipe.
A pair of hourglass-shaped rollers is structured so that it can be divided into two parts along the radial direction at the axial center position, and an approximately short cylindrical auxiliary roll is inserted between each divided part. The object of the present invention is to provide an apparatus for manufacturing a rectangular tube with a structure that is possible.

Embodiment First, an embodiment of the apparatus of the present invention will be explained.The rectangular tube manufacturing apparatus of the present invention has a breakdown roll, a fin pass roll, a squeeze roll, and a sizing roll, similar to the conventional apparatus shown in FIG. 5(A). It consists of a series of rolls arranged in multiple stages, such as rolls and Turk's head rolls, and welding equipment such as a resistance welder and bead cutter.

Among these roll groups, the fin pass roll 20 is constructed as shown in FIG. That is, the upper roll 21 is a drum-shaped roll having a circular hole as a whole, and is provided with a radially extending fin plate 22 at the center position in the axial direction. Further, the lower roll 23 is a pair with the upper roll 21, and is an hourglass-shaped roll with a circular hole. Further, each of the left and right side wheels 24.25 that form a pair with each other is configured to be divisible in the axial direction, and each of the divided portions 24a, 24b, 25a
, 25b, auxiliary rolls 26, 27 can be inserted between them. That is, each side roll 24.25 is
It is mainly composed of divided parts 24a, 24b, 25a, and 25b located at both ends in the axial direction (both upper and lower sides in FIG. 1), and by joining the divided surfaces along the radial direction, It forms a drum-shaped roll similar to the lower roll 23. In other words, each side roll 24, 25 is an hourglass-shaped roll that can be divided at the center in the axial direction. And the auxiliary rolls 26 and 27 are
It is formed into a substantially short cylindrical shape with the same diameter as the outer diameter at the dividing point of the side 0-rules 24 and 25.

Next, the operation of the apparatus of the present invention equipped with the above-mentioned fin pass roll 20, that is, the detailed explanation of the present invention, will be explained in the second section.
The figure is an explanatory view showing the process of changing the cross-sectional shape of a steel band into a square tube. The material, which is initially a flat plate, is turned over on both sides while passing through a breakdown roll and reaching the fin pass roll 20. Form into a tube by gradually curving it to the side. In the fin pass roll 20, the side rolls 24.25 have auxiliary rolls 26.27 inserted therein, so that the hole shape is oval or oval. Since the roll 23 is a round hole type roll, the material is formed into a tubular shape with an oval or elliptical cross section as shown in FIG. Then, seam welding is performed on the butt ends, and pea cutting is performed to form the main pipe. The main tube is an oval cross-section tube or an oval tube, and is formed into a square tube by passing it through a sizing roll and a Turk's head roller. In that case, if you make a rectangular tube as a square tube,
Since the main tube has an anisotropic shape such as an oval shape, it can be easily formed into a square shape.

Also, when making a rectangular tube that is one size larger, the equipment mentioned above uses tf Zr on the fin pass roll 20.
@ ,,,i1,. -7,24,251C,□. -J
26.27 is additionally inserted as shown in Fig. 3. According to such a fin pass roll 20, it is possible to create an oval or elliptical main tube with a longer major axis than before. Therefore, by forming the main tube into a square shape, a large-sized square tube can be manufactured.

When changing the size in this way, the upper roll 21 and lower roll 23 of the fin pass roll 20 are not replaced, but the auxiliary rolls 26 and 27 are replaced with the side rolls 24 and 25.
Since the existing rolls can be reused, there is no need to trowel rolls for each size of rectangular tube to be manufactured, and the number and type of rolls can be reduced, reducing equipment costs and operation. Costs can be reduced.

Note that the side rolls 24 and 25 in the fin pass roll 20 described above have divided portions 24a in which the hole shape is circular.
124b, 25a, and 25b, if the auxiliary rolls 26 and 27 are removed as shown in Figure 4, it becomes an hourglass-shaped roll with a circular hole shape, so that the main tube of the Hokage can also be formed. 8- Can also be done.

In addition, square steel pipes are generally used as building materials, and their sizes are in 50-inch increments for millimeter pipes and in 2-inch increments for inch pipes.
If the axial length of 6.27 is made to match these size intervals, each size can be accommodated by preparing a large number of identical auxiliary rolls and simply changing the number used. Therefore, by doing this, it is possible to reduce the number of types of auxiliary rolls required.

Effects of the Invention As is clear from the above explanation, according to the method of the present invention, a strip-shaped material is formed into a main tube with an oval cross section or an elliptical cross section, and then the main tube is formed into a square tube. The rolls used in the tube forming process are not particularly restricted by the size of the rectangular tube and can be shared across multiple sizes, reducing the number of required rolls and reducing equipment and running costs. .

In addition, the apparatus of this invention can handle main tube forming of many different sizes by changing the number of auxiliary rolls used for the side rolls in the fin pass roll, so the number and types of rolls that need to be prepared can be reduced. Equipment costs and running costs can be reduced.

[Brief explanation of drawings]

Fig. 1 is a front view showing an example of the fin pass roll in the device of this invention, Fig. 2 is an explanatory diagram showing the process of changing the cross-sectional shape in the method of this invention, and Fig. 3 shows the state in which the auxiliary roll is added. 4 is a front view with the auxiliary rolls removed, FIG. 5(A) is a schematic diagram showing the pipe forming process by the roll forming method, and FIG. 5(B) is a cross-sectional view of the pipe forming process by the conventional method. An explanatory diagram showing the change process, FIG. 6 is a front view showing a fin pass roll in a conventional device. 20... Fin pass roll, 21... Upper roll,
22... Fin plate, 23... Lower roll, 2
4.25 ・-41-i'I' O-ru, 24a
, 24b. 25a, 25b...divided parts, 26.27-... auxiliary rolls. Applicant: Kawasaki Steel Co., Ltd. agent Patent attorney: Toyoda Sankaku (and 1 other person) Figure 6 Procedures (Amended on his own initiative) June 22, 1985 Commissioner of the Patent Office Manabu Shiga 1, Indication of the case 1988 Patent Application No. 113597 2, Name of the invention Method for manufacturing square tubes and its device 3, Relationship with the person making the amendment Patent applicant address 1-1-28 Kitahonmachi-dori, Chuo-ku, Kobe, Hyogo Prefecture Name (125) Kawasaki Steel Corporation 4, agent address: 3-4-18-5, Mita, Minato-ku, Tokyo, the “Scope of Claims” and “Detailed Description of the Invention” columns of the specification subject to amendment, and drawings; 6. Contents of amendment (1) The "Claims" will be corrected as shown in the attached sheet. (2) " from line 14 to line 16 on page 3 of the specification"
The main tube 8 is formed. " is corrected to "The main tube 8 is formed into a square tube 11 by the square forming roll group 9." (3) From page 5, line 6 to line 12 of the specification, "There was a problem with the rectangular cross section." is changed to "When a rectangular tube with a rectangular cross section is formed using a round tube as the main tube." Since a larger forming force is required, there is a problem in that the roll stand and drive device for corner forming must be made larger, or the number of roll stands must be increased, leading to a rise in equipment costs.'' (4) "Sizing roll," from line 9 to line 10 on page 6 of the specification is deleted, and "Turk's head roll" on line 10 is corrected to "angular forming roll j." (5) "81, lines 11 to 12 of the specification"
"Sizing roll and Turk's head roll" is corrected to "ragonal forming roll". (6) Delete “anisotropic” on line 14 of the same page,
In the 15th line, ``with a similar shape'' is added between ``easily'' and ``E-gon''. (7) Insert the following sentence after "Toga dekiru." on page 10, line 10 of the specification. ``This method can also be used to manufacture round tubes by first forming such an oval shape and then, for example, welding it and then forming it into a round shape. J(8) The reference number "10" in Figure 5 (A) of the drawings has been replaced with "9" as shown in the attached sheet.
Correct. Scope of Claims (1) A metal strip is passed through multiple forming rolls to bend both sides L1 in the longitudinal direction of the strip to form an oval or elliptical cross section, and the abutted side edges A method for manufacturing a square tube, which comprises welding to create an oval or elliptical mother tube, and then forming the mother tube into a square tube with a square cross section. (2) A series of main pipe forming rolls that run a metal strip material in its longitudinal direction and curve both sides of the material into a tubular shape, and a square tube forming process that forms the obtained main pipe into a square cross section. In the rectangular tube manufacturing apparatus comprising a group of rolls, the parent tube forming roll group presses the strip material curved into a tubular shape from four directions, up, down, right and left, with respect to a center line along its longitudinal direction; Equipped with a pair of drum-shaped rolls on the left and right,
Among the drum-shaped rolls, the left and right pair of rolls are configured to be able to be divided into two parts along a dividing plane along the radial direction at the center position in the axial direction, and between each divided part there is a roughly short cylindrical shape. A rectangular tube manufacturing device characterized by being configured such that an auxiliary roll can be inserted therein.・1. ′ −U−1□−

Claims (2)

[Claims] (1) By passing a metal strip through multiple forming rolls, both sides in the longitudinal direction of the strip are curved upward to form an oval or oval cross section, and the butted side edges are A method for manufacturing a rectangular tube, which comprises welding to create an oval or elliptical mother tube, and then forming the mother tube into a rectangular tube with a square cross section. (2) A series of main pipe forming rolls that run a metal strip in the longitudinal direction and gradually curve both sides toward the top to form a tube shape, and a square shape that forms the obtained main pipe into a square cross section. In the rectangular tube manufacturing apparatus equipped with a group of tube forming rolls, the group of main tube forming rolls is configured to move the tube-shaped material curved into a tubular shape into four directions above, below, left and right with respect to a center line along its longitudinal direction.
A pair of upper and lower drum-shaped rolls and a pair of left and right drum-shaped rolls are applied from the direction, and one pair of left and right of the drum-shaped rolls is divided into two parts along a dividing plane along the radial direction at the center position in the axial direction. 1. An apparatus for manufacturing a rectangular tube, characterized in that the apparatus is configured such that an approximately short cylindrical auxiliary roll can be inserted between each divided portion.