KR102488172B1 - Forming apparatus double wall sewer pipe and Double wall sewer pipe manufacturing equipment included the same - Google Patents

Abstract

The present invention relates to a forming apparatus for a double-walled sewer pipe and double-walled sewer pipe manufacturing equipment including the same. The forming apparatus includes: a pair of concave-convex forming rollers which are disposed on left and right sides of a rectangular profile having a hollow of a synthetic resin product to be extruded and conveyed and which continuously form concave-convex parts having a concave-convex structure by pressing and pressing the left and right sides of the rectangular profile; a pair of shape deformation prevention rollers which are disposed between sides of the pair of concave-convex forming rollers, are positioned on upper and lower sides of the rectangular profile, and support upper and lower surfaces of the rectangular profile to prevent the upper and lower surfaces of the rectangular profile from being extended and deformed outward when the concave-convex parts are formed on the left and right sides by pressing of the upper and lower surfaces of the rectangular profile; an air cooler which is disposed on a front side of the pair of concave-convex forming rollers and on the left and right sides of the rectangular profile and which cools air by discharging the air air from the left and right sides of the rectangular profile where the concave-convex parts are formed by the pair of concave-convex forming rollers, wherein the forming apparatus further includes a pair of preheating heaters which are positioned on a rear side of the pair of concave-convex forming rollers and disposed on the left and right surfaces of the rectangular profile to be conveyed as needed, and which preheat a concave-convex forming surface of the rectangular profile to enhance the concave-convex parts. According to the present invention, productivity can be increased.

Description

Forming apparatus double wall sewer pipe and Double wall sewer pipe manufacturing equipment included the same}

The present invention relates to a forming apparatus for a double-wall sewer pipe and a double-wall sewer pipe manufacturing facility including the same, which strengthens the bonding force and adhesion by the adhesive part on the side of the double-wall sewer pipe having a continuous coupling structure of a square profile, improves the compressive strength and flexural strength, and improves the existing It relates to a double wall sewer pipe forming device and a double wall sewer pipe manufacturing facility including the same to increase productivity compared to the above.

In general, various types of sewage pipes for discharging various sewage or rainwater have been developed and used, and are mainly made of materials that are easy to install in the process of burial underground, have excellent durability, and do not corrode wastewater, sewage, and seawater. Among them, a sewage pipe with increased durability by molding polyethylene into a double wall has been proposed.

The polyethylene (PE) double-walled sewer pipe is manufactured by winding a polyethylene tube in a spiral shape and then adhesively fixing the polyethylene tube by injecting a polyethylene resin therebetween.

Polyethylene (PE) double-walled sewer pipe is easy to install and join compared to other pipes, so it is economical when considering material cost, construction cost, and service life. .

Such a conventional double-walled sewer pipe is manufactured by extruding into a square profile having a hollow, vacuum sizing and cooling the square profile, and then forming it into a circular tube shape using roller rotational force. In this forming process, the square profile is manufactured. While winding the outside of the roller in a spiral shape, an adhesive is injected between the rolled square profiles to bond adjacent square profiles, thereby forming a double wall structure as a single circular tube body.

The conventional double-wall sewer pipe 100 manufactured in this way has a circular tubular shape, and forms a cross-sectional coupling structure in which square profiles 110 as shown in FIG. 1 are continuously coupled by an adhesive layer 200.

However, the conventional double-walled sewer pipe 100 having the above-described process and cross-sectional coupling structure is manufactured by simply bonding a square profile 110 having a flat outer surface with an adhesive layer 200 using an adhesive, which is cured in the manufacturing process. Since the square profiles in the state are simply adhered, there is a problem in that the adhesion between the square profiles 110 is poor.

In particular, the double-walled sewer pipe is a material that is put into the manhole, and external factors such as bending act when it is put into the manhole. There is a problem that the adhesive force is easily released and the adhesive part between the square profiles is separated while being bent by this bending force.

In addition, when used after being buried underground, even when an impact is applied from the outside, there is a problem such that the bonding force on the side of the adhesive portion between the square profiles is easily released, so there is an inconvenience that frequent replacement or maintenance work must be performed.

Republic of Korea Patent No. 10-1764745

The present invention has been devised in consideration of and solving the above problems, for a double wall sewer pipe capable of greatly improving the bonding force and adhesion at the side of the adhesive part between square profiles through improvement of the structure on the side of the square profile, which is a component for the double wall sewer pipe. Its purpose is to provide a molding device and a double wall sewer pipe manufacturing facility including the same.

The present invention enables to improve the compressive strength and flexural strength of the double wall sewer pipe side manufactured by the adhesive bonding force between square profiles, and to increase productivity compared to the conventional double wall sewer pipe forming device and providing a double wall sewer pipe manufacturing facility including the same But it has a purpose.

An object of the present invention is to provide a double-wall sewer pipe forming device and a double-wall sewer pipe manufacturing facility including the same to manufacture a double-wall sewer pipe with enhanced durability.

In order to achieve the above object, the molding apparatus for a double wall sewage pipe of the present invention is disposed on the left and right sides of a square profile side having a hollow of a synthetic resin product to be transported, and presses and presses the left and right sides of the square profile to continuously form the concave-convex portion having a concave-convex structure. A pair of concave-convex shaping rollers to form; Arranged between the pair of concave-convex shaping rollers and located on the upper and lower sides of the square profile, and support the upper and lower surfaces of the square profile to form concavo-convex parts on the left and right sides by pressing the pair of concavo-convex shaping rollers. a pair of shape-deformation prevention rollers to prevent expansion and deformation in an outward direction; An air cooler disposed at the front side of the pair of concavo-convex forming rollers and on the left and right sides of the square profile side, and discharging air from the left and right sides of the square profile side on which concavo-convex parts are formed by the pair of concavo-convex forming rollers for cooling. It is characterized by including;

Here, a pair of preheating heaters located at the rear side of the pair of concavo-convex forming rollers and disposed on the left and right sides of the square profile side to be transported and preheating the concavo-convex forming surface on the square profile side to increase the efficiency of concavo-convex forming It may be a configuration that further includes;

In addition, a double-walled sewer pipe manufacturing facility for achieving the above object is, in one form, an extruder for melting and extruding a synthetic resin; A vacuum sizing unit for cooling the extruded product extruded through the extruder by passing it through a water bath after vacuum sizing into a square profile having a hollow with a vacuum frame; A molding device for a double-walled sewer pipe that continuously forms concavo-convex portions having concavo-convex structures on the left and right sides of the square profile conveyed through the vacuum sizing portion; Forming machine that manufactures a double-walled sewer pipe in the form of a circular pipe by rolling up and taking out the square profile with concavo-convex parts formed on the left and right sides by the forming device for double-wall sewer pipe, and then injecting adhesive into the left and right side boundary parts between the square profiles and bonding them to each other. It is characterized by including;

Here, the forming device for the double-walled sewer pipe includes a pair of preheating heaters disposed on left and right sides of the square profile that is transferred through the vacuum sizing unit and preheating the left and right sides of the square profile; a pair of concavo-convex shaping rollers for continuously forming concavo-convex portions having a concavo-convex structure by pressing left and right side surfaces of the square profile preheated and transported by the pair of preheaters; Arranged between the pair of concave-convex shaping rollers and located on the upper and lower sides of the square profile, and support the upper and lower surfaces of the square profile to form concavo-convex parts on the left and right sides by pressing the pair of concavo-convex shaping rollers. a pair of shape-deformation prevention rollers to prevent expansion and deformation in an outward direction; An air cooler disposed at the front side of the pair of concavo-convex forming rollers and on the left and right sides of the square profile side, and discharging air from the left and right sides of the square profile side on which concavo-convex parts are formed by the pair of concavo-convex forming rollers for cooling. It may be a composition including;

In addition, several different forms and configurations may be described below.

According to the present invention, by improving the structure through concavo-convex molding on the side of the square profile, which is a component for manufacturing a double-walled sewer pipe, it is possible to significantly improve the bonding strength and adhesive strength of the bonding part between the square profiles compared to the prior art, and through this, the bonding between the square profiles It is possible to enhance durability, such as improving the compressive strength and flexural strength of the double wall sewer pipe manufactured by bonding force, and to increase the processing speed per minute compared to the existing ones, thereby achieving useful effects that can increase productivity.

According to the present invention, it is possible to reduce the defect rate compared to the prior art, and to achieve useful effects of extending the expiration date and maintenance period according to stable use in the field.

1 is a view showing a configuration including a cross-sectional structure of a conventional double wall sewer pipe.
2 is a schematic block diagram showing a double wall sewer pipe manufacturing facility including a forming device for a double wall sewer pipe according to an embodiment of the present invention.
Figure 3 is a schematic configuration diagram showing a forming apparatus for a double wall sewage pipe in the present invention.
Figure 4 is a view showing a double-walled sewage pipe side coupling structure manufactured through the molding apparatus and manufacturing equipment of the present invention.
5 is a view showing a square profile structure molded by a molding device for a double wall sewer pipe in the present invention.
6 is a cross-sectional state view showing a main part of a double wall sewer pipe manufactured through a forming machine in the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the present invention can have various changes and various forms, specific embodiments will be illustrated in the drawings and described in detail in the text. However, it should be understood that this is not intended to limit the present invention to the specific disclosed form, and includes all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals have been used for like elements throughout the description of each figure. In the accompanying drawings, the dimensions of the structures are shown enlarged than actual for clarity of the present invention.

Also, in this application, the terms "length", "height", "width" and "thickness" may be used to describe the relative arrangement and orientation of components as shown in the figures.

In the present invention, the concavo-convex part 111 formed on the square profile 110 will be formed as a part where the adhesive is injected and the boundary between the square profiles is adhesively connected, and the components will have a corresponding arrangement. will be.

As shown in FIG. 2, the double-wall sewer pipe manufacturing facility 1000 including the double-wall sewer pipe molding device according to an embodiment of the present invention includes an extruder 1100, a vacuum sizing unit 1200, and a double-wall sewer pipe molding device 1300. , a take-off machine 1400, and a forming machine 1500.

The extruder 1100 melts and extrudes the synthetic resin and molds a hollow tubular synthetic resin product having a predetermined shape according to the shape of the extrusion die.

The vacuum sizing unit 1200 includes a vacuum frame for sizing (standardizing) the tubular body of a square profile having a hollow for the synthetic resin product passing through the extruder 100 and a water tank for water cooling.

The retractor 1400 is a component that induces smooth transfer by traction for a square profile transferred on a manufacturing facility.

The forming machine 1500 includes a forming roller and an adhesive dispenser, and performs a function of winding and withdrawing a square profile in a roll form through rotation in the forming roller, and winding and rolling in a roll form in the adhesive dispenser to adjacent square profiles. It is provided to perform the function of injecting the adhesive into the boundary portion.

That is, the double-walled sewer pipe 100 in the form of a circular pipe made of a square profile can be manufactured only when it finally passes through the formr 1500.

At this time, the vacuum sizing unit 1200 and the take-up unit 1400 can be omitted if necessary.

The vacuum sizing unit 1200 is a configuration for sizing (standardizing) the tubular body of the square profile, and if this is omitted, it can be replaced by providing a square frame having a hollow for the extrusion die on the side of the extruder 1100 In other words, manufacturing facilities and production speed can be reduced.

Here, the extruder 1100, the vacuum sizing unit 1200, the take-up machine 1400, and the foaming machine 1500 can use known devices as they are or remove any one or more of them, and a more detailed description is to omit

The forming device 1300 for the double-wall sewer pipe is a configuration that forms the main feature in the present invention, and will be mainly described.

As shown in FIG. 3 , the forming apparatus 1300 for a double-wall sewer pipe includes a preheater 1310, a concavo-convex forming roller 1320, a shape deformation prevention roller 1330, and an air cooler 1340.

The preheater 1310, the concavo-convex forming roller 1320, the shape-deformation prevention roller 1330, and the air cooler 1340 are disposed at opposite positions to each other and are provided in a pair arrangement.

At this time, the preheater 1310 is also a configuration that can be omitted when the vacuum sizing unit 1200 on the manufacturing facility side is omitted and the extruder 1100 side directly provides a square profile.

In the present invention, the front side is referred to as 'front' and the rear side is referred to as 'rear' based on the direction in which the square profile 110 is transported on the manufacturing facility.

The preheater 1310 is located at the rear side of the concavo-convex forming roller 1320 and is disposed on the left and right sides of the square profile 110 to be transferred, and the concave-convex forming surface (left and right side surfaces) to be formed on the square profile 110 side ) as a configuration for preheating, it is possible to prevent and minimize molding defects as well as to increase molding efficiency during concavo-convex molding work through preheating before molding.

At this time, the preheater 1310 dries the left and right sides of the square profile 110 to remove moisture and soften them.

Here, it is preferable that the preheater 1310 is provided so as to be movable so that when the standard of the square profile 110 is changed, it can be used by adjusting the arrangement interval.

The uneven shaping roller 1320 is arranged to be located on the left and right sides of the square profile 110 having a hollow of the synthetic resin product to be transferred, and presses the left and right sides of the square profile 110 to be transferred, as shown in FIG. It is a configuration for continuously forming the concave-convex portion 111 having a concavo-convex structure.

The concave-convex forming roller 1320 has a configuration in which a plurality of protrusions 1321 are continuously and repeatedly formed along the outer diameter, and a pair is installed to rotate relative to each other.

That is, it plays a role of continuously forming a concavo-convex structure corresponding to the shape of the protruding molding part on the left and right sides of the square profile 110 that is transferred through the protruding molding part 1321.

The concave-convex forming roller 1320 is preferably configured to adjust the arrangement interval with the square profile through position movement on the left and right sides of the square profile 110 being transferred. Through such a position movement structure, the square profile 110 Of the concave-convex portions 111 formed on the left and right side surfaces, the molding depth for the concave portion can be adjusted.

The concave-convex forming roller 1320 is provided to form the concave-convex portion 111 by alternately forming concave and convex portions on the left and right sides of the square profile 110 being transferred, respectively. ) is preferably provided to form a depth of 0.5 mm to 1.1 mm for the portion.

Here, when the depth is less than 0.5 mm, the adhesion and adhesion at the boundary between the square profiles 110 may decrease, and when the depth exceeds 1.1 mm, the adhesion and adhesion at the boundary between the square profiles 110 may be improved. However, since its durability is low, the manufactured double wall sewer pipe 100 has a weakness in use, such as being easily bent or deformed.

Here, the concavo-convex part 111 side concave part formed through the protruding molding part 1321 of the concavo-convex forming roller 1320 has a certain depth within the above-mentioned range, but the injection efficiency of the adhesive and the square profile 110 ) In order to maintain the durability of the side itself, it is formed to have an inclined surface at the upper and lower ends, respectively.

Here, in the inclined plane, it is preferably formed in the range of 25 degrees to 35 degrees relative to the vertical plane.

The shape deformation prevention roller 1330 is located on the upper and lower sides of the square profile 10 that is disposed and transported between the sides of the uneven forming roller 1320, which is a pair of configurations, and supports the upper and lower surfaces of the square profile 110 to be uneven. It is a configuration to prevent the upper and lower surfaces of the square profile 10 from being expanded outward and deformed when the concavo-convex part 111 by the pressing of the forming roller 320 is formed on the left and right sides of the square profile 110.

That is, when forming the concavo-convex part on the side of the square profile 110, it performs a function of enabling a stable molding operation and preventing the occurrence of defects.

At this time, it is preferable that the shape deformation prevention roller 1330 is also provided to be movable in the vertical direction so that the position can be adjusted and used when the standard of the square profile 110 is changed.

The air cooler 1340 is located in the front side of the pair of concave-convex forming rollers 1320 and is disposed on the left and right sides of the square profile 110 to be transferred, and is It is a configuration for cooling by discharging air from the left and right sides of the square profile 110 on which the concavo-convex portion 111 is formed by the concave-convex portion 111.

That is, the air cooler 1340 performs a function of drying and curing the square profile 110 on which the concavo-convex portion 111 has been formed.

At this time, it is preferable that the air cooler 1340 be configured to be movable in the left and right directions or to be used by adjusting the air discharge pressure and speed.

The operation and use state of the double wall sewer pipe manufacturing equipment 1000 including the double wall sewer pipe forming apparatus 1300 according to the present invention having the above-described configuration will be described with reference to FIGS. 2 to 6 .

Here, manufacturing facilities including both the vacuum sizing unit 1200 and the take-up unit 1400 will be mainly described.

In the extruder 1100, the synthetic resin product is extruded into a tubular body having a hollow shape by melting and extruding the synthetic resin.

In the vacuum sizing unit 1200, the synthetic resin product extruded through the extruder 1100 is sized into a square profile 110 having a predetermined standard, and cooled via a water bath.

In the forming apparatus 1300 for a double-walled sewer pipe, first, the left and right sides of the square profile 110 having a hollow being transported via the vacuum sizing unit 1200 are preheated through the preheating heater 1310.

로 히팅시켜 사각프로파일(110)을 예열 처리할 수 있다.At this time, the preheating heater 1310 is 200 to 300

The square profile 110 may be preheated by heating.

In addition, by contacting the left and right side surfaces of the square profile 110 transferred in a preheated state by the concavo-convex forming roller 1320, the concavo-convex part 111 is formed on the left and right sides of the square profile 10, respectively. to mold

At this time, the concavo-convex part 111 is formed on the square profile 110 through the protruding molding part 321 of the concave-convex forming roller 1320, but formed to a depth of 0.5 mm to 1.1 mm with respect to the concave part. It can be made, and it can have a structure in which inclined surfaces are formed at the upper and lower ends, respectively.

In addition, when forming the concavo-convex part on the square profile 110, the shape deformation prevention roller 1330 supports the upper and lower surfaces of the square profile 110 side, which is a non-molded part, to prevent shape deformation, such as preventing up and down expansion. perform a function

The square profile 110 having the concavo-convex portion 111 formed in this way passes through the air cooler 1340, and is cooled and hardened by air discharge.

In the take-up machine 1400, the square profile 110 having the concavo-convex part 111 formed by the double-walled sewage pipe forming device 1300 is pulled by the formr 1500.

Subsequently, in the formr 1500, the square profile 110 having the concavo-convex part 111, which is pulled and transported through the rotating forming roller, is rolled up and pushed out, and at this time, the gap between the square profiles 110 adjacent to each other An adhesive layer is formed by injecting an adhesive through an adhesive dispenser between (boundary portions) to have adhesive strength and adhesive strength between the square profiles 110, and as shown in FIG. 4, the square profiles 110 are continuously formed by the adhesive layer 120. Arranged to manufacture and complete the double wall sewage pipe 100 made of a circular pipe shape.

At this time, on the forming machine 1500, as the adhesive resin is injected into the border of the square profile 110 through the adhesive dispenser, the adhesive layer 120 is injected and filled into the concave-convex portion 111, especially the concave portion, which is a concave groove. Since it is formed, it is possible to manufacture a double wall sewer pipe 100 with improved durability as well as increased adhesion and adhesion between the square profiles 110 compared to the prior art.

In the present invention, the feed speed of the square profile 110 on the manufacturing facility can be controlled to 5 to 10 m per minute, and the processing speed can be increased compared to the existing 2 to 3 m per minute, thereby increasing the productivity. can provide

Accordingly, according to the present invention, the structure of the square profile 110 side is improved through the forming device 1300 for double wall sewer pipe and finally formed, thereby reducing the defect rate due to the manufacture of the double wall sewer pipe 100 and improving the quality of the product. can provide an advantage that can be improved.

The present invention is not limited to the specific preferred embodiments described above, and various modifications can be made by anyone skilled in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes are within the scope of the claims.

1300: Forming device for double wall sewer pipe
1310: preheater
1320: concavo-convex forming roller
1330: shape deformation prevention roller
1340: air cooler

Claims (10)

A pair of concavo-convex shaping rollers disposed on the left and right sides of the hollow square profile of the synthetic resin product to be transported, and pressurizing the left and right sides of the square profile to continuously form concavo-convex portions having a concavo-convex structure;
Arranged between the pair of concavo-convex shaping rollers and located on the upper and lower sides of the square profile, and support the upper and lower surfaces of the square profile to form concavo-convex parts on the left and right sides by pressing the pair of concavo-convex shaping rollers. a pair of shape-deformation prevention rollers to prevent expansion and deformation in an outward direction;
An air cooler for cooling by discharging air from the left and right sides of the square profile formed by the pair of concavo-convex shaping rollers and disposed on the left and right sides of the square profile side and located in the front side of the pair of concavo-convex shaping rollers. ; Including,
The pair of concavo-convex shaping rollers are provided to adjust the arrangement interval with the square profile by moving the position on the left and right sides of the square profile to be transferred, thereby forming depth for the concave-convex part formed on the left and right sides of the square profile. A forming device for a double wall sewer pipe configured to adjust the. According to claim 1,
A pair of preheating heaters located at the rear side of the pair of concavo-convex forming rollers and disposed on the left and right sides of the square profile side to be transferred and preheating the concavo-convex forming surface on the square profile side to increase concavo-convex forming efficiency; A molding apparatus for a double wall sewer pipe further comprising a. According to claim 1,
The pair of concave-convex shaping rollers are installed so that a plurality of protrusions are continuously and repeatedly formed along the outer diameter and rotate relative to each other;
A forming device for a double wall sewer pipe that continuously forms a concavo-convex structure corresponding to the shape of the protruding molding part on the left and right sides of the square profile to be transported. delete According to claim 1,
The pair of concave-convex forming rollers,
Forming apparatus for a double-walled sewer pipe that alternately forms concave parts and convex parts on the left and right sides of the square profile to be transferred, but forms them at a depth of 0.5 mm to 1.1 mm with respect to the concave part. An extruder for melting and extruding a synthetic resin;
A vacuum sizing unit for cooling the extruded product extruded through the extruder by passing it through a water bath after vacuum sizing into a square profile having a hollow with a vacuum frame;
A molding device for a double-walled sewer pipe that continuously forms concavo-convex portions having concavo-convex structures on the left and right sides of the square profile conveyed through the vacuum sizing portion;
Forming machine that manufactures a double-walled sewer pipe in the form of a circular pipe by rolling up and taking out the square profile with concavo-convex parts formed on the left and right sides by the forming device for double-wall sewer pipe, and then injecting adhesive into the left and right side boundary parts between the square profiles and bonding them to each other. ; Including,
The forming device for the double wall sewer pipe,
a pair of preheating heaters disposed on left and right sides of the square profile transported through the vacuum sizing unit and preheating the left and right sides of the square profile;
a pair of concavo-convex shaping rollers for continuously forming concavo-convex portions having a concavo-convex structure by pressing left and right side surfaces of the square profile preheated and transported by the pair of preheaters;
Arranged between the pair of concavo-convex shaping rollers and located on the upper and lower sides of the square profile, and support the upper and lower surfaces of the square profile to form concavo-convex parts on the left and right sides by pressing the pair of concavo-convex shaping rollers. a pair of shape-deformation prevention rollers to prevent expansion and deformation in an outward direction;
An air cooler disposed at the front side of the pair of concavo-convex forming rollers and on the left and right sides of the square profile side, and discharging air from the left and right sides of the square profile side on which concavo-convex parts are formed by the pair of concavo-convex forming rollers for cooling. ; including,
The pair of concavo-convex shaping rollers are provided to adjust the arrangement interval with the square profile by moving the position on the left and right sides of the square profile to be transferred, thereby forming depth for the concave-convex part formed on the left and right sides of the square profile. configured to regulate
The feed rate of the square profile is 5 to 10 m per minute,
The pair of preheating heaters are double wall sewage pipe manufacturing equipment that preheats by heating to 200 ~ 300 ℃. delete delete An extruder for melting and extruding synthetic resin into a hollow rectangular profile;
A molding device for a double-walled sewer pipe that continuously forms concavo-convex portions having concavo-convex structures on the left and right sides of the square profile that is extruded and transported through the extruder;
Forming machine that manufactures a double-walled sewer pipe in the form of a circular pipe by rolling up and taking out the square profile with concavo-convex parts formed on the left and right sides by the forming device for double-wall sewer pipe, and then injecting adhesive into the left and right side boundary parts between the square profiles and bonding them to each other. ; Including,
The forming device for the double wall sewer pipe,
A pair of concavo-convex forming rollers for continuously forming concavo-convex portions having a concavo-convex structure by pressing left and right sides of the square profile conveyed through the extruder;
Arranged between the pair of concave-convex shaping rollers and located on the upper and lower sides of the square profile, and support the upper and lower surfaces of the square profile to form concavo-convex parts on the left and right sides by pressing the pair of concavo-convex shaping rollers. a pair of shape-deformation prevention rollers to prevent expansion and deformation in an outward direction;
An air cooler disposed at the front side of the pair of concavo-convex forming rollers and on the left and right sides of the square profile side, and discharging air from the left and right sides of the square profile side on which concavo-convex parts are formed by the pair of concavo-convex forming rollers for cooling. ; including,
The pair of concavo-convex shaping rollers are provided to adjust the arrangement interval with the square profile by moving the position on the left and right sides of the square profile to be transferred, thereby forming the molding depth for the important concave part of the concavo-convex part formed on the left and right sides of the square profile. A double-walled sewer pipe manufacturing facility configured to adjust the delete

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