KR101443242B1

KR101443242B1 - Angled pipe and method for manufacturing the same

Info

Publication number: KR101443242B1
Application number: KR1020140042012A
Authority: KR
Inventors: 천인수; 천영종
Original assignee: 주식회사 대동강업; (주) 엠제이스틸; 주식회사 대우스틸
Priority date: 2014-04-08
Filing date: 2014-04-08
Publication date: 2014-09-22

Abstract

The present invention relates to a method of manufacturing an angled pipe with improved flexural rigidity. The purpose of the present invention is to reinforce a steel plate structurally by cold rolling and reinforcing ribs and save materials. The method of manufacturing an angled pipe with improved flexural rigidity according to the present invention includes a first step of preparing plate-shaped raw materials having uniform thickness; a second step of molding a reinforcement unit having a thinner thickness and a denser tissue than that in other sections by performing cold rolling on a portion of the raw materials prepared in the first step; and a third step of forming the plate-shaped material having the reinforcement unit and the reinforcing ribs by the second step into a quadrangle having four edges and four faces and manufacturing an angled pipe.

Description

TECHNICAL FIELD [0001] The present invention relates to an angled pipe manufacturing method,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a steel pipe used for various applications such as construction, civil engineering, and the like, and more particularly to a steel pipe manufacturing method in which a steel plate is structurally reinforced by cold rolling and reinforcing ribs, .

Generally, various pipes are used for construction and civil engineering.

As shown in FIG. 1, each of the conventional pipes 1 (rectangular pipes are shown and described as an example) has four sides and corners. As shown in FIG. 2, the plate- (2) are rounded to form a circular shape. - Welded joints of the round foaming tube (3) are welded. - Welded joints are cut do. Of course, the manufactured tube 1 is used through the cutting process.

Since the conventional pipe 1 having such a structure has the same thickness and four surfaces in all portions, the rigidity against bending is poor, and if a high strength material is used, it is possible to increase rigidity, but the manufacturing cost is high High-strength materials are not realistic.

In order to solve this problem, as shown in FIG. 3, a tube 1 having a reinforcing rib 1a has been proposed. Each tube 1 provided with the reinforcing ribs 1a provides the bending force against the bending of the reinforcing ribs 1a, so that the flexural rigidity is improved as compared with the tubes without the reinforcing ribs.

However, since the reinforcing ribs 1a have limitations in improving the flexural rigidity of the tubes 1, the number of tubes 1 to be used is increased and the safety of the structure to which each tube 1 is applied is deteriorated.

On the other hand, Patent Literature 1 (Laid-Open Patent Application No. 10-2010-0109820) is a technique for machining the reinforcing ribs 1a on the respective pipes 1. The above-mentioned Patent Document 1 includes a step of sandwiching a die having a tapered portion to be inserted into or removed from a hollow tube and having a chamfer at four corners and a recess having recesses for forming recesses on upper and lower surfaces, ; Inserting a die into which the die is divided, which is divided or integrated into two pieces according to the length of each pipe, into the pipe holder of the lower mold having the lower punch and the pipe holder with the protrusion having the same shape as the groove; Lowering the upper mold having the upper punch having the protrusion having the same shape as the groove and pressing the hollow pipe into which the die is inserted by the upper punch and the lower punch to form a groove in the hollow pipe; Forming a groove in the hollow pipe, and then removing the die inserted into the pipe, thereby forming a reinforcing rib in each pipe.

Patent Literature 1 has a problem that productivity is very low because a reinforcing rib is formed in each pipe by lifting and lowering the upper and lower punches by inserting a die in each pipe and the die is taken out from each pipe to form a reinforcing rib.

Published Patent No. 10-2010-0109820

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing a square pipe having improved bending rigidity and reduced bending stiffness.

According to the present invention, there is provided a square pipe having three or more corners and three or more surfaces, a reinforcing portion which is rolled on the surface to have a thickness thinner than the other portion, and at least one reinforcing rib protruding from the reinforcing portion .

A method for manufacturing a square pipe having improved flexural rigidity according to the present invention includes: a first step of preparing a plate-shaped raw material having a uniform thickness; A second step of rolling a part of the raw material prepared in the first step to form a reinforcing rib which is thinner in thickness than the other rim but has a dense structure and a concave-convex reinforcing rib in the reinforcing part; And a third step of forming a plate-like material having a reinforcing portion and a reinforcing rib in a square shape having at least three corners and faces through the second step to manufacture a square pipe.

According to the method for manufacturing a square pipe with improved bending stiffness according to the present invention, a reinforcing portion by cold rolling and an embossing type reinforcing rib are formed on a plate made of steel to increase the compactness of the structure and increase the rigidity against bending Since the flexural rigidity of each pipe itself is maximized, the use amount of each pipe can be reduced, thereby reducing cost and improving workability.

In addition, the raw material is expanded by cold rolling, and the cost can be reduced because the size of the raw material for manufacturing the same size of the tube can be reduced by the increased size.

1 is a perspective view of a conventional pipe.
2 is a view showing a manufacturing process of each tube according to the prior art.
3 is a front view of an embossed tube having embossed ribs as a conventional tube.
4 is a perspective view of each tube according to the present invention.
Fig. 5 is a view showing a manufacturing process of raw materials for each pipe according to the present invention. Fig.
6A and 6B are views showing another manufacturing state of the reinforcing rib and the reinforcing rib of each tube according to the present invention, respectively.
7A to 8D are diagrams showing another example of each tube according to the present invention.

A square pipe having improved bending stiffness according to the present invention is a square having three or more edges and three or more surfaces, and a square pipe is described as an example in the detailed description and drawings.

As shown in FIG. 4, each tube 10 of the present invention has a square shape having four vertexes, corners, and faces, and four faces 11 are provided with reinforcing portions 12 And the reinforcing ribs 13 are formed in the reinforcing portion 12 in the form of an embossing.

The reinforcing portion 12 is made thinner than the surface 11 by the two cold rolling rollers, but the bending rigidity of each tube 10 is improved because the structure is dense and the mechanical properties such as elongation and tensile strength are excellent.

In addition, since the material is increased during the processing of the reinforcing portion 12, the material can be reduced, thereby reducing the cost.

The reinforcing portion 12 may be formed on each of the four faces 11 as shown in the figure, and each of the reinforcing portions 12 may be elongated along the longitudinal direction of the reinforcing portion 12, but the present invention is not limited thereto. .

The reinforcing ribs 13 may protrude toward the inside or protrude toward the outside as shown in the drawing when the finished product is taken as a reference, and may be formed in various shapes in the reinforcing portion 12.

The reinforcing rib 13 may be formed on both the surface 11 and the reinforcing portion 12 without being formed in the reinforcing portion 12 and may be formed independently at the other position or surface 11.

A method of manufacturing a square pipe with improved flexural stiffness according to the present invention will be described with reference to FIG.

1. Raw material preparation.

Prepare a flat steel plate with the raw material (10-1). The length of the raw material 10-1 is not limited, and the width is cut so as to fit around the circumference of the tube 10.

2. Processing of reinforcement parts.

The reinforcing portion 12 is processed by cold rolling the raw material 10-1 (cold rolling conditions are known and vary depending on the material and thickness, etc., so that specific numerical values are not described), and the upper and lower cold rolling rollers 20 The raw material 10-1 passes between the cold rolling rollers 20 and 21 when the cold rolling rollers 20 and 21 are rotated when the raw material 10-1 is passed between the cold rolling rollers 20 and 21. In this process, 10-1) is formed by cold rolling to form a reinforcing portion 12 that becomes denser in structure.

3. Stiffening rib processing.

When the processing of the reinforcing portion 12 is completed, the reinforcing ribs 13 are formed on the reinforcing portions 12 of the raw material 10-1 by the upper and lower embossing rollers 30 and 31. The upper side embossing roller 30 and the lower side embossing roller 31 are provided with protrusions 30a and grooves 31a opposite to each other and the upper side embossing roller 30 and the lower side embossing roller 31 The reinforcing ribs 13 are processed by the projections and grooves while being rotated. The size, spacing, and quantity of the reinforcing ribs 13 vary depending on the size, quantity, distance, etc. of the protrusions 30a and the grooves 31a formed on the peripheries of the upper and lower embossing rollers 30 and 31.

4. Manufacture of pipes.

Up to the above step, the plate material 10-1 is provided with the reinforcing ribs 12 and the reinforcing ribs 13, and the raw material 10-1 is manufactured into the respective pipes 10.

That is, the plate-shaped raw material 10-1 is formed into a circular shape by joining the circular-shaped forming tube 10-2 and the circular tube 10-3, Each tube 10 is manufactured.

Examples that can be practiced from the present invention will be described below.

6A and 6B, the reinforcing ribs 13 are rolled only on one side of the raw material 10-1, and the reinforcing ribs 13 are not formed symmetrically by the same structure and conditions, It is possible to protrude the rolling direction of the sheet 12 or the direction opposite to the rolling direction.

The reinforcing ribs 12 and the reinforcing ribs 13 can be variously arranged as shown in FIGS. 7A to 7D, and two reinforcement portions 12 are formed on one surface 11 as shown in FIG. The reinforcing ribs 13 may be formed in a zigzag shape as shown in FIG. 7B, and the reinforcing ribs 13 may be formed in a zigzag shape as shown in FIG. The reinforcing portion 12 and the reinforcing rib 13 may have a certain length and may be parallel to each other or may have a zigzag shape so that the reinforcing portion 12 and the reinforcing rib 13 have a predetermined length as shown in FIG. 4, the reinforcing ribs 12 and the reinforcing ribs 13 may be formed to be long along the longitudinal direction of the tubes 10.

On the other hand, the reinforcing ribs 12 and the reinforcing ribs 13 can be simultaneously formed through equipment capable of performing two functions of cold rolling and embossing.

Up to now, it has been described that each pipe having the reinforcing portion and the reinforcing rib is made of the plate-shaped raw material as a starting material. However, it is also possible to manufacture each pipe first, and to process the reinforcing portion and the reinforcing rib in each pipe.

10: each tube, 11: cotton
12: reinforcing portion, 13: reinforcing rib

Claims

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A first step of preparing a plate-like raw material having a uniform thickness;
A second step of cold-rolling a part of the raw material prepared in the first step to form a reinforcing part having a thinner thickness than the other part but having a fine structure and molding a reinforcing rib in an embossed form in the reinforcing part;
And a third step of forming a plate-like material having a reinforcing portion and a reinforcing rib in a quadrangle shape having four corners and surfaces through the second step,
In the second step, the raw material is passed between the upper and lower cold rolling rollers 20 and 21, and the raw material is thinned by cold rolling by rotation of the two cold rolling rollers 20 and 21, A step 2-1 of forming the reinforcing portion 12 to be dense,
The upper side embossing roller 30 and the upper side embossing roller 30 are integrally formed with the upper side embossing roller 30 and the upper side embossing roller 30 by passing through the upper and lower embossing rollers 30 and 31, The embossing roller 31 and the lower side embossing roller 31 are provided with protrusions 30a and grooves 31a which are opposite to each other and process the embossing reinforcing ribs 13 protruding toward one side by the protrusions and grooves,
The third step is a step 3-1 of forming a circular shape in which the reinforcing portion and the reinforcing rib are joined to each other so that the joints facing the plate-shaped material are not bonded. In the third step, A step 3-2 of joining the welded portion of the circular material through the step 3-2, a step 3-3 of arranging the welded portion of the circular material passed through the step 3-2, And (3) a step of forming the grooves.

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