WO2011083925A2

WO2011083925A2 - Method and apparatus for manufacturing a corrugated steel pipe

Info

Publication number: WO2011083925A2
Application number: PCT/KR2010/009138
Authority: WO
Inventors: 김한곤
Original assignee: Kim Han Gon
Priority date: 2010-01-08
Filing date: 2010-12-21
Publication date: 2011-07-14
Also published as: WO2011083925A3; KR100956425B1

Abstract

The present invention relates to a method and apparatus for manufacturing a corrugated steel pipe, in which a spiral corrugation is formed on the body of the pipe, and the inner surface of the body of the pipe is smooth without any curvature to thereby improve the strength of the pipe and enable a fluid to stably flow during use. The method for manufacturing a corrugated pipe according to the present invention comprises the following steps: feeding a steel sheet into a first roll forming machine (100a); forming a first corrugated portion (A), including a recess formed integrally therein, on the surface of the steel sheet; forming a pair of tilted portions (136) outwardly from either side of the first corrugated portion (A); forming said pair of tilted portions (136) into a pair of second corrugated portions (B) having a recesses formed integrally therein, and which are corrugated in the direction opposite to the first corrugated portion; firstly pressing the top of the first corrugated portion (A) such that the second corrugated portions (B) are tightly disposed opposite one another; secondly pressing the top of the first corrugated portion (A) such that the top of the first corrugated portion (A) forms the same plane as the surface of the steel sheet and tightly contacts the recesses of the second corrugated portions (B); and passing the steel sheet through a second roll forming machine (100b) and winding the steel sheet into a cylindrical shape.

Description

Manufacturing method and apparatus of corrugated steel pipe

The present invention is made of a corrugated steel pipe spirally formed in the tube body to the inner diameter portion is smooth without bending to improve the strength of the product itself, as well as the production of corrugated steel pipe to ensure that the flow of fluid at all times during use A method and apparatus are disclosed.

In general, a concrete fume pipe is mainly used as a pipe for guiding fluid movement in a road, a harbor, and a sewage treatment plant. The concrete fume pipe requires heavy equipment input during transportation and handling due to an increase in its weight and volume. During construction, the construction period becomes longer due to the increase of the joints due to the deterioration of workability due to the installation and dismantling of the formwork, and there is a problem of being subject to seasonal constraints due to freezing of the foundation cement connecting the joints.

In addition, the concrete fume pipe is excellent in strength, but weak to the impact from the outside during transportation and construction has a problem that is easily cracked or broken when severe.

Therefore, in recent years, steel pipes are rolled in a spiral shape, and steel pipes having a lock seam connected to the rolled boundary are being used.

As shown in Figs. 1 and 2, a general steel pipe is made of a tubular body 1, which is rolled in a spiral and whose boundary portion is lock cored. And this tube body (1) is made of a simple form, all of which is smooth except for the lock core connecting portion. The steel pipe of such a structure solves the problems of the concrete fume pipe, but has a problem that the strength of the inner diameter part 11 except the lock core connection portion is considerably inferior, and is used for guiding the transfer of fluids such as water and sewage. It was not widely used.

In order to solve the above problems of the general steel pipe, as shown in FIGS. 3 and 4, spirally wound the steel plate along the longitudinal direction around the tube body 1 connecting the rolled boundary to the lock core. A corrugated steel pipe is known in which a pleat (2) in which a recessed portion (2a) in the form of a recess is formed on the inner diameter portion (11) is formed.

The conventional corrugated steel pipe is manufactured through the following process.

First, provided with a plate-shaped steel sheet rolled in a roll state, and then mounted on the uncoiler to operate the uncoiler to release the rolled steel sheet, and pass the released steel sheet to the first roll forming machine, the first roll forming machine According to the structure, the corrugations 2 in the state where the recessed portion 2a of the depression shape is integrated in the steel sheet are formed in the longitudinal direction, and the connecting rings are formed at both ends.

When the corrugation (2) is formed in the longitudinal direction and the steel plate formed with the linking ring is passed through the second roll forming machine, the steel sheet formed with the corrugation (2) and the linking ring is rolled in a spiral while the rolled boundary portion is connected to the lock core. Accordingly, the steel sheet is formed in the tubular body 1 in a cylindrical shape while the corrugation 2 is formed, thereby obtaining a corrugated steel pipe having a structure as shown in FIGS. 3 and 4.

However, such a corrugated steel pipe has a problem that the flowability of the fluid passing through the concave portion 2a is greatly deteriorated, and in this case, the pressure acting on the inner diameter 11 of the pipe body 1 is excessively increased. There is a problem that the leakage occurs because the lock core connection part is often broken. In addition, the sediment is accumulated in the concave portion (2a) has a problem that the fluid is contaminated due to the decay of the sediment when used for a long time.

Meanwhile, in order to solve the above problems, Utility Model Registration No. 187831 and Patent Application No. 2001-67507 are provided with a double-wall corrugated steel pipe, and the above techniques are smooth pipes having smooth surfaces on the inner diameter of the corrugated body. Contact the pipe body and weld the pipe and the smooth pipe to form a corrugated pipe to form an integrated concave indentation to form a corrugated body so that the flow does not interfere with the flow when the fluid is guided during use after construction In addition, the sediment does not accumulate, but in the structure fixed by contacting the smooth tube with a smooth surface on the inner diameter of the corrugated tube body as in the above structure, the material cost is increased as well as the use of the smooth tube, and the overall weight is also increased. There are other problems such as, and workability also decreases because welding must be performed in the working process. There were other problems.

Therefore, as shown in FIG. 5, the pleats 12 are formed in a spiral shape by closely contacting both ends of the inlet of the concave portion 12a formed in the tube body 1 to be in contact with each other. While the corrugation 12 is formed, the inner diameter portion 11 of the tubular body 1 is developed to have a corrugated steel pipe smoothed without bending, so that the strength of the tubular body 1 itself is improved and the use of a smooth tube. Except to reduce the weight and manufacturing cost, as well as to ensure a stable flow of the fluid during use.

Prior art literature

Patent Literature

(Patent Document 0001) Domestic Utility Model Registration No. 187831 (announced on July 15, 2000), Figure 2

(Patent Document 0002) Domestic Patent Application No. 2001-67507 (published May 9, 2003), Figure 7

However, the conventional corrugated steel pipes as described above have a pipe body (1) due to various reasons, such as being pulled to the floor or collided with heavy equipment during construction, or a heavy weight such as a vehicle passes over the steel pipe after construction. There is a problem that the wrinkles 12 protruding outwardly are frequently damaged.

This is because the pleats 12 have a structure that is very vulnerable to external force because they are molded to be in close contact with the inlet end of the concave portion (12a). Therefore, when an external force is applied to the pleats 12, the structure in which the external force is concentrated on both ends of the inlet of the concave portion 12a is inevitable regardless of the shape of the pleats 12.

For example, as shown in Figure 6a, when the pleat 12 receives a positive pressure (F), the inlet of the concave portion (12a) is opened while the close pleat 12 is pressed, so that the flow of fluid flowing inside the tube 6B, when the wrinkle 12 receives the transverse pressure F1, the wrinkle 12 easily breaks and is lost, and the strength of the tube is not only weak, but also the wrinkle is severe. 12) Cracks in the area lead to a serious problem of leakage into the area.

The present invention has been made to solve the above problems, it is an object of the present invention to provide a method and apparatus for producing a corrugated steel pipe excellent in the strength of the wrinkles while the inner diameter of the tube body excluding the wrinkles are smooth.

In order to achieve the above object, the manufacturing method of the corrugated steel pipe of the present invention comprises the steps of inputting a flat plate to the first roll forming; Forming a first wrinkle part having a recess in the flat steel plate surface; Forming a pair of inclined portions inclined outward on both sides of the first wrinkle portion; Shaping each of the inclined portions into a pair of spaced apart second wrinkle portions that are opposite to the first wrinkles and have a recess portion; Pressing the first upper end of the first wrinkle part to form the second wrinkle part in close contact with each other; Pressing the second upper end of the first wrinkle part to form the upper end of the first wrinkle part to be in close contact with the recess of the second wrinkle part while forming the same plane as the surface of the steel sheet; And forming the cylindrical shape by passing the steel sheet through a second roll forming machine to roll in a spiral shape.

In addition, after the step of inserting the flat plate into the first roll forming machine, the step of forming the first ring portion and the second wrinkle portion during the forming of the connecting ring for forming the lock core connection to both ends of the steel sheet further go through In the step of rolling the steel sheet through a second roll forming machine to form a spiral by rolling in a spiral shape, the steel sheet is formed such that the boundary portion is connected to a lock core by a connecting ring to form a tubular body in a cylindrical shape.

In addition, the apparatus for manufacturing a corrugated steel pipe of the present invention comprises a first roll forming machine for forming the uncoiler and the corrugations in the longitudinal direction in which the recessed portion of the recess is formed on the surface of the flat steel sheet rolled into the uncoil in a roll state; In the apparatus for producing corrugated steel pipes having a second roll forming machine for rolling a steel sheet exiting the first roll forming machine in a spiral shape and forming a cylindrical shape, the first roll forming machine is rotated while being engaged with each other through an uneven portion formed in the center. A first upper and lower die roller for forming a first wrinkle part having a recess in the flat steel plate; Conical, lower die rollers disposed behind the first upper and lower dies to form inclined portions inclined outwardly to both sides of the first pleats; A dual upper and lower die rollers which engage with each other through a pair of uneven parts formed at a center thereof and rotate to form a pair of second wrinkle parts having a concave part in a direction opposite to the first wrinkles on the inclined part; In the center has a recess having a width larger than the second wrinkles, and the first wrinkles are first pressed downward in the state in which the first wrinkles and the second wrinkles are seated on the recesses so that the second wrinkles are mutually in the grooves. A second upper and lower roller configured to be formed in close contact with each other; And positioned behind the second upper and lower die rollers to pressurize the first wrinkle part downwards to make the upper end of the first wrinkle part coplanar with the surface of the steel sheet and to be in close contact with both ends of the inlet of each recess of the second wrinkle part. And the third upper and lower die rollers are formed to shape the recess to maintain the airtightness without any gaps.

In this case, the third upper roller is a flat roller, and the recess formed in the second lower roller consists of a single horizontal plane and a pair of vertical walls.

In addition, the dual phase, the lower roller has a double roller, the lower roller has a pair of first uneven portion formed in the center and the second uneven portion formed between the first uneven portion, in this case the first uneven portion and It is preferable that 2 uneven parts are formed continuously, and the length of a said 1st uneven part is smaller than a 2nd uneven part, and the width | variety of a 1st uneven part is narrower than a 2nd uneven part.

In addition, between the upper and lower rollers, and the upper and lower rollers, the middle upper roller having the same shape as the second upper roller, and the stone located at the center of the recess of the first fold part in the center of the recess of the second roller An intermediate lower roller having an additional shape may be disposed.

The present invention configured as described above forms a crease in the shape of a dimple which consists of a pair of right-angled triangular creases facing each other to be in close contact with each other, and the smooth support part which is tightly supported at both ends of the inlet of the recess is formed at both ends of the inlet of the recess. Formed to be connected integrally, when the external force is applied to the wrinkles by effectively canceling or dispersing the external force applied to the wrinkles can effectively produce a corrugated steel pipe that can significantly improve the strength of the wrinkles in a simple way There is.

1 is a main view of the general steel pipe.

Figure 2 is a longitudinal sectional view of the main portion of a typical steel pipe.

3 is a yab perspective view showing an example of a conventional corrugated steel pipe.

Figure 4 is a longitudinal sectional view of the main portion showing an example of a conventional corrugated steel pipe.

Fig. 5 is a longitudinal sectional view of a main portion showing another example of a conventional corrugated steel pipe.

6A and 6B are enlarged longitudinal cross-sectional views, respectively, showing a state in which an external force is applied to the corrugated steel pipe of FIG.

7 is a perspective view showing a corrugated steel pipe according to the present invention.

8 is a main longitudinal cross-sectional view showing a corrugated steel pipe according to the present invention.

9 is a front view showing a manufacturing apparatus of corrugated steel pipe according to the present invention.

10 is a view sequentially arranged rollers of the first roll forming machine constituting the apparatus for manufacturing corrugated steel pipe according to the present invention in the molding order.

11 is a flow chart showing a method of manufacturing a corrugated steel pipe according to the present invention.

100a ... first roll forming machine 100b ... second roll forming machine

110 1st, upper and lower rollers 113, uneven

136 ... Tilt section 138 ... Connection

130 ... conical, lower roller 140 ... double, lower roller

143 ... 1st uneven part 144 ... 2nd uneven part

150 ... middle and lower rollers 160 ... 2nd and lower rollers

190 3rd, lower roller A ... 1st wrinkle

B ... second wrinkles

The features and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are defined in the technical spirit of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. It must be interpreted to mean meanings and concepts.

DETAILED DESCRIPTION Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. Like reference numerals refer to like elements, and only different parts will be mainly described so as not to overlap for clarity.

As shown in Fig. 7 and 8, the corrugated steel pipe made in accordance with the present invention is a whole of the bellows-shaped corrugated body having a concave concave portion 30 in the inner diameter portion 11 of the tube body (1) Has The pleats have a pair of right triangle pleats 21 and 21 facing each other in close contact with each other. The

wrinkles

21 and 21 form a flat support 22 that is in close contact with the inner ends 11 and 31 of the concave inlet 30 while forming the same plane as the inner diameter 11 of the tube body 1. It is connected integrally through.

Accordingly, the smooth support 22 has a gap between the recessed part 30 and the gap by completely closing the entrance of the recessed part 30 in a state in which both ends thereof are integrally connected to the hypotenuse 21a of the wrinkled part 21 forming a right triangle. Will remain confidential.

The corrugated steel pipe of such a structure has a crevice 20 of the crease 20 formed to improve the strength of the tubular body 1 when the fluid is guided to the corrugated steel pipe of the present invention in the process of being used after construction. Since the airtight state is maintained without the inner diameter portion 11 of the tube body 1 is a smooth smooth state except the lock core connection portion. Therefore, the fluid flowing inside the tube body 1 not only has good flow, but also no sediment.

In addition, when an external force is applied to the wrinkles 20 exposed to the outside, since the strength of the wrinkles 20 is structurally strong, the wrinkles 20 are not easily damaged.

That is, when the positive pressure (F) is applied to the pleats 20, the positive pressure (F) is the both ends of the inlet of the concave inlet portion 30 through the hypotenuses (21a, 21a) forming the

pleats

21, 21 It is delivered to (31, 31), the hypotenuses (21a, 21a) is a state that one end is supported while facing each other and the other end is supported on both ends (31, 31) of the inlet end of the indentation 30 The positive pressure F applied through the mutual supporting force of the

parts

21 and 21 cancels out, thereby minimizing damage and deformation of the wrinkles 20.

In addition, when the side pressure (F1) is applied to the pleats 20, the side pressure (F1) acts as a right angle surface of the pleats 21 on one side, each of the

pleats

21, 21 are supported facing each other Since the hypotenuse 21a of the corrugation portion 21 to which the side pressure F1 is applied is supported by the inlet end 31 of the concave portion 30, the side pressure F1 corresponds to the corrugation portion 21. It is dispersed along the hypotenuse 21a of () and is absorbed to the opposite wrinkle part 21 side. Thus, damage and deformation of the pleats 20 are minimized.

In addition, since most of the external force (F, F1) transmitted through the hypotenuse (21a) of the pleats 21 is absorbed by both ends (31, 31) of the inlet of the indentation 30, the inlet of the indentation 30 is closed The smooth support part 22 is hardly influenced by an external force. Therefore, since the damage and deformation caused by the external forces F and F1 hardly occur in the smooth support part 22, the fluid flowing in the tube always has good flowability.

The corrugated steel pipe configured as described above is manufactured through the following process.

First, as shown in FIG. 9, when the uncoiler is operated in a state in which a plate-shaped steel sheet rolled in a roll state is mounted on an uncoiler, the first roll forming machine 100a on one side is released while the rolled steel sheet is released. In this case, the steel sheet is gradually formed to have a wrinkle as described above while passing through the various forming rollers (110 ~ 190) constituting the first roll forming machine (100a) step by step. At this time, as shown in Figure 4, the connecting ring 138 for forming the lock core connection to both ends of the steel sheet is also formed together.

Therefore, the steel sheet formed by passing through the first roll forming machine (100a) to form a corrugation is passed through the second roll forming machine (100b) and rolled in a spiral shape to form a cylindrical shape while connecting the connecting ring 138 to the core of the steel sheet. When the edges are connected, a corrugated steel pipe having a plurality of corrugations having a spiral concave portion in the inner diameter portion of the tube body is completed.

The apparatus for manufacturing a corrugated steel pipe of the present invention for carrying out such a manufacturing method is basically the uncoiler and the wrinkles in the state in which the recessed portion of the recess shape is integrated on the surface of the flat steel plate rolled into the uncoil in the longitudinal direction. A first roll forming machine (100a) to form and a second roll forming machine (100b) for rolling a steel sheet exiting the first roll forming machine (100a) spirally to form a cylindrical shape, the first roll forming The rest of the uncoiler and the second roll forming machine 100b except for the machine 100a are the same as in the related art, and thus a detailed description thereof will be omitted.

As shown in Figure 10, the first roll forming machine (100a) is a first, upper, lower roller (formerly referred to as 'uneven portion') formed in the central portion 113a and protrusion 113b (hereinafter referred to as 'uneven portion') ( 110). The first, upper and lower rollers 110 are installed to be engaged with each other through the concave-convex portion 113 in a spaced apart state corresponding to the thickness of the flat steel plate. The flat plate inserted into the first roll forming machine 100a has a first wrinkle portion A having a recessed portion integrally formed on the surface thereof while passing between the first, upper and lower rollers 110.

On the other hand, the first, the upper and lower die roller 110 is the step of increasing the length of the uneven portion 113 in the direction of the flat plate for smooth molding of the first wrinkles (A) step by step of the uneven portion 113 It is desirable to be provided in multiple stages so that the width is reduced in stages. In this case, as the flat plate passes through the first, upper and

lower rollers

110 and 120 installed in multiple stages, the first wrinkle portion A increases to an appropriate height and is reduced to an appropriate width.

At the rear of the first, upper and lower rollers 110, conical and lower rollers 130 are disposed. The conical roller 131 has a body having the same concave portion 133a as the first upper roller 111 in the center and the conical surface 134 narrowing to both sides. The lower conical roller 132 is composed of a body having a conical surface 135 widening to both sides having the same protrusion 133b as the first lower roller 112 in the center. The conical, lower die roller 130 is of course spaced apart as much as the thickness of the steel sheet. The conical and lower die rollers 130 form inclined portions 136 inclined outwardly to both sides of the first wrinkle portion A of the steel sheet exiting the first, upper and lower die rollers 110.

The double upper and lower rollers 140 are disposed at the rear of the conical and lower rollers 130. The double upper and lower rollers 140 have a pair of first uneven parts 143 and a second uneven part 144 positioned between the first

uneven parts

143 and 143. The first concave-convex portion 143 includes a double protrusion 143a formed on the double upper roller 141 and a double recess 143b formed on the double lower roller 142 so as to correspond to the protrusions 143a. . In addition, the second uneven portion 144 has a recess 144a formed in the same manner as the recess 133a of the conical roller 132 between the protrusion 143a and the protrusion 143a of the dual roller 141. It consists of a protrusion 144b formed in the same manner as the protrusion 133b of the conical roller 132 between the recessed part 143b and the recessed part 143b of the double lowered roller 142.

At this time, the first uneven portion 143 and the second uneven portion 144 should be formed continuously, the length (h) of the first uneven portion 143 is the length (H) of the second uneven portion 144 It is smaller and the width w of the first uneven portion 143 should be narrower than the width W of the second uneven portion 144. Of course, the double upper and lower rollers 140 are spaced apart as much as the thickness of the steel sheet.

The double upper and lower die rollers 140 have a first pleated portion (1) on the inclined portion 136 of the steel sheet exiting the conical and lower die rollers 130 while rotating in a state where the first and second

uneven parts

143 and 144 are engaged with each other. A pair of second wrinkles B having integrally recessed portions in the opposite direction to A) is molded. In addition, the dual upper and lower rollers 140 may be installed in multiple stages as the first, upper and lower rollers 110 so that the second wrinkles B may be smoothly formed.

The second upper and lower die rollers 160 are disposed at the rear of the double upper and lower die rollers 140. The second upper and lower die rollers 160 have

recesses

163 and 164 formed at their centers, respectively. First and second wrinkles A and B are seated on the

recesses

163 and 164, respectively. The

recesses

163 and 164 are formed to allow the first wrinkles A and the second wrinkles B to be seated in a relaxed manner, and the recesses 164 formed on the second lower roller 162 have a single horizontal surface. 164a and a pair of vertical surfaces 164b. Of course, the second upper and lower die rollers 160 are spaced apart as much as the thickness of the steel sheet.

The second upper and lower die rollers 160 configured as described above presses the upper end of the first wrinkle part A of the steel sheet exiting the dual upper and lower die rollers 140 downwardly, thereby causing the first wrinkle part ( A) is the inlet of the indents are in close contact with each other at the same time the top is formed flat, the second wrinkles (B) are in close contact with each other while being in close contact with the vertical surface (164b) of the recessed portion 164 of the second lower roller (162). It is molded into a pair of right triangles.

Meanwhile, the second upper and lower die rollers 160 are multi-stage like the double upper and lower die rollers 140 or the first and upper and lower die rollers 110 for smooth molding of the first and second wrinkles (A and B). It is preferable to install. In this case, the second upper and lower die

rollers

160, 170, and 180 are installed in multiple stages so that the depth of the recess is gradually decreased, and the upper and lower ends of the first wrinkle portion A are gradually lowered in accordance with the traveling direction of the flat plate to be flattened. do.

In addition, between the double upper and lower die rollers 140 and the second upper and lower die rollers 160, a separate intermediate upper and lower die rollers 150 are further provided for smooth molding of the first and second wrinkle parts A and B. It is desirable to. The intermediate upper roller 151 is formed in the same shape as the second upper roller 161, the intermediate lower roller 152 of the double lower roller 142 in the center of the main portion 163 of the second upper roller 161. A narrower and smaller sized protrusion 155 is formed than the protrusion 144b. Of course, the intermediate upper and lower die rollers 150 are spaced apart as much as the thickness of the steel sheet. The intermediate upper and lower rollers 150 configured as described above are pressurized on the upper end of the first wrinkle part A before the steel sheet exiting the dual upper and lower rollers 140 enters the second upper and lower rollers 160. The concave portion of the corrugated portion A is formed to be in close contact with both side walls of the protrusion 155 of the intermediate lower roller 152, and the intermediate lower roller 152 has the second wrinkles B of the intermediate lower roller 152. Preliminary molding is performed to facilitate the molding operation of the second upper and lower mold rollers 160, which are formed to be in close contact with the vertical wall surface of the recess 154.

According to the present invention, the third upper and lower rollers 190 are disposed behind the second upper and lower rollers 160. The third upper roller 191 is a flat roller, the third lower roller 192 is the same roller as the second lower roller 162. Accordingly, the third upper and lower die rollers 190 have a first wrinkle portion A such that the first wrinkle portion A of the steel sheet exiting the second upper and lower die rollers 160 is coplanar with the surface of the steel sheet. By fully pressing the upper end of the first wrinkle portion (A) is supported in close contact with the inlet end (B1, B1) of the inlet portion of each of the second wrinkle portion (B) while the recess portion of the second wrinkle portion (B) without a gap It prevents and shape | molds so that the smooth support part which may be integrated with the 2nd wrinkle part B may be. Of course, the third upper and lower die rollers 190 are spaced apart as much as the thickness of the steel sheet.

Using the apparatus for producing a corrugated steel pipe of the present invention configured as described above can form a corrugated steel pipe through the following method.

First, after mounting the plate-shaped steel sheet rolled in an uncoiler, the uncoiler is operated to release the rolled steel sheet, and the released flat steel sheet is put into the first roll forming machine 100a. (S1)

In this way, the first steel sheet (A) having a recessed portion integrally formed on the surface of the flat steel plate is passed through the first, upper, lower die roller 110, the flat plate introduced into the first roll forming machine (100a). S2)

As described above, the steel sheet on which the first wrinkle portion A is formed passes through the conical and lower rollers 130. In this process, both sides of the first wrinkle portion A are pressed by the conical and lower rollers 130. A pair of inclined portions 136 inclined outward are formed. (S3)

The steel sheet having the inclined portion 136 is formed to pass through the double upper and lower rollers 140, and in this process, the inclined portions 136 are pressed by the dual upper and lower rollers 140, and are opposite to the first wrinkles A. Is formed into a pair of second wrinkles B having both the direction and the recess in one body. (S4)

On the other hand, in the middle of the form of the intermediate upper roller 151 of the same shape as the second upper roller 161 and the recessed portion 164 in the center of the second lower roller 162 in the rear of the double upper, lower mold roller 140 When the lower die roller 152 is further provided, the first wrinkle portion A before the middle upper roller 151 enters the second upper and lower die roller 160 from the dual phase and the lower die roller 140. ) By pressing the upper end of the first wrinkle portion (A) to be in close contact with both side walls of the protrusion 155 of the intermediate lower roller 152 and at the same time the intermediate lower roller (152) second wrinkles (B) ) May be molded to be in close contact with the vertical wall surface of the recessed portion of the intermediate roller. Therefore, the subsequent forming operation of the second upper and lower die rollers 160 is facilitated.

The steel sheet formed with the second wrinkle part B passes through the second upper and lower mold rollers 160, and in this process, the upper end of the first wrinkle part A is formed by the second upper mold roller 161. At the same time, the first wrinkle is formed flat and at the same time, the second wrinkle portion (B) is formed on the inner wall surface of the groove portion 164 of the second lower die roller 162 formed of a horizontal surface 164a and a pair of vertical surfaces 164b. While being in close contact, they are molded into a pair of right triangles facing each other.

The steel sheet formed by a pair of right angled triangles facing the second upper and lower die rollers 160 to be in close contact with each other to pass through the third upper and lower die rollers 190, In the process, the upper end of the first pressurized first wrinkle portion (A) is pressurized secondly and the first wrinkle portion (A) is completely in close contact with the inlets (B1, B1) of the indentation portion of the second wrinkle portion (B) and At the same time, it is molded to form the same plane as the surface of the steel sheet. Therefore, the recessed part of the 2nd wrinkle part B by the 1st wrinkle part A can be kept airtight without a gap. (S5)

Thereafter, when the first and second wrinkles (A, B) are formed in the longitudinal direction and the steel sheet having the connection ring 138 is passed through the second roll forming machine (100b), the steel sheet is a structural action of the mold Due to the spirally wound inside the tubular body (1) to form a tubular corrugated steel pipe of the structure as shown in Figure 7 and 8 is obtained. (S6)

On the other hand, when the first wrinkle portion (A) and the second wrinkle portion (B) in the state in which the concave portion is integrated in the longitudinal direction while the steel sheet passes through the first roll forming machine (100a) in the above process, the Both ends of the steel sheet may be molded together with a connecting ring 138 for the lock core connection is made. In this case, the first wrinkle portion (A) and the second wrinkle portion (B) is formed in the longitudinal direction and pass through the second roll forming machine (100b) the steel sheet with the connecting ring 138 is formed at both ends Then, due to the structural action of the second roll forming machine (100b) the steel sheet is rolled spirally in the second roll forming machine (100b) and the boundary portion is the lock core connection by the connecting ring 138, accordingly the steel sheet is In the state where the first and second wrinkles (A, B) is formed, the tubular body is formed in a cylindrical shape and eventually becomes a corrugated steel pipe having a structure as shown in FIGS. 7 and 8.

As described above, preferred embodiments of the present invention are described above with reference to the drawings, but the present invention is not limited to the above-described embodiments, and those skilled in the art may modify the present invention without departing from the spirit of the present invention. Possible, such modifications will fall within the scope of the invention.

Claims

Injecting a flat plate into the first roll forming machine;

Forming a first wrinkle part having a recess in the flat steel plate surface;

Forming a pair of inclined portions inclined outward on both sides of the first wrinkle portion;

Shaping each of the inclined portions into a pair of spaced apart second wrinkle portions that are opposite to the first wrinkles and have a recess portion;

Pressing the first upper end of the first wrinkle part to form the second wrinkle part in close contact with each other;

Pressing the second upper end of the first wrinkle part to form the upper end of the first wrinkle part to be in close contact with the recess of the second wrinkle part while forming the same plane as the surface of the steel sheet; And

Passing the steel sheet through a second roll forming machine, the method of producing a corrugated steel pipe, characterized in that it comprises a step of forming in a spiral rolled in a cylindrical shape.
The method of claim 1,

After the step of inserting the flat plate into the first roll forming machine to the step of forming the first ring portion and the second wrinkle portion when forming the connecting ring for forming the lock core connection at both ends of the steel sheet further ,

Wherein the steel sheet is passed through a second roll forming machine to form a cylindrical shape rolled in a spiral form the steel sheet is formed to form a tubular body in a cylindrical shape by connecting the lock portion of the steel core by the connecting ring of the corrugated steel pipe How to make.
The uncoiler, the first roll forming machine for forming the wrinkles in the longitudinal direction in which the recessed portion of the recessed portion is integrated on the surface of the flat steel plate rolled in the uncoil, and the steel sheet exiting the first roll forming machine in a spiral shape In the manufacturing apparatus of the corrugated steel pipe having a second roll forming machine to be rolled into a cylindrical shape,

The first roll forming machine,

First upper and lower die rollers which engage with each other through the concave and convex portions formed at the center thereof to form a first wrinkle portion having the concave portions integrally on the flat steel plate surface;

Conical, lower die rollers disposed behind the first upper and lower dies to form inclined portions inclined outwardly to both sides of the first pleats;

A dual upper and lower die rollers which engage with each other through a pair of uneven parts formed at a center thereof and rotate to form a pair of second wrinkle parts having a concave part in a direction opposite to the first wrinkles on the inclined part;

In the center has a recess having a width larger than the second wrinkles, the first wrinkles are first pressed downward in the state in which the first wrinkles and the second wrinkles are seated on the recesses so that the second wrinkles are mutually A second upper and lower roller configured to be formed in close contact with each other; And

Located at the rear of the second upper and lower die rollers, the second wrinkle part is pressurized downward to support the upper end of the first wrinkle part in the same plane as the surface of the steel sheet and to be in close contact with both ends of the inlet of each recess of the second wrinkle part. Apparatus for producing a corrugated steel pipe, characterized in that comprises a third upper, lower die roller for molding so as to maintain the airtight without gaps.
The method of claim 3, wherein

The third phase roller is a flat roller manufacturing apparatus, characterized in that the roller.
The method of claim 3, wherein

The recessed part formed on the second lower roller has a single horizontal surface and a pair of vertical walls.
The method of claim 3, wherein

The double upper and lower rollers have a pair of first uneven portions formed in the center and a second uneven portion formed between the first uneven portions.
The method of claim 6,

The first uneven portion and the second uneven portion are formed continuously,

The length of the first concave-convex portion is smaller than the second concave-convex portion, the width of the first concave-convex portion manufacturing apparatus of the corrugated steel pipe, characterized in that narrower than the second concave-convex portion.
The method of claim 3, wherein

An intermediate upper roller having the same shape as the second upper roller, and a protrusion positioned at the center of the recess of the first fold portion are formed between the double upper and lower rollers and the second upper roller. Apparatus for producing corrugated steel pipe, characterized in that the intermediate lower roller made of a form.