JPH0537117Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The pressure-resistant synthetic resin pipe for underground burial as referred to in the invention is a buried pipe for use by being buried underground, and is used for water pipes, sewage (drainage water), etc. ) This is a tube mainly used as a protective tube for electric wires and telephone lines.

<Conventional technology> Conventionally, concrete pipes and cast iron pipes have often been used as underground pipes of this type, but these pipes are both heavy and long. The workability was extremely poor because it was difficult to form, and it required a great deal of time and effort to lay it underground. In recent years, a spiral tube made of synthetic resin material has been developed as a new tube that can solve this problem (see Figure 13), but this synthetic resin tube is much lighter than the Huyum tube, etc., so it can be transported easily. is easy,
Since it has the advantage of being convenient to bury underground, it has become widely used today.

<Problem that the invention aims to solve> However, underground pipes need to withstand strong earth pressure, and in order to have pressure resistance,
As shown in FIG. 13, the tube wall 01 had to be made thick. However, if the pipe wall is made thick, a large amount of synthetic resin material is required as a molding material, and it is difficult to transport especially large diameter pipes.
The work of laying it underground had to be difficult.

Therefore, the present invention eliminates the various drawbacks of the conventional synthetic resin pipes for underground burial, maximizes the advantages of the pipes, reduces the amount of synthetic resin material used, The objective is to obtain a pressure-resistant synthetic resin pipe for underground burial with a completely new structure that is light in overall weight and has excellent pressure resistance.

<Means for solving the problem> The present inventor researched, prototyped, and tested various structures of synthetic resin pipes that could achieve this purpose. It was concluded that the weight of the pipe as a whole could not be reduced, and that the amount of synthetic resin material used could not be significantly reduced.

The present invention was developed as a result. In other words, the present invention departs from the conventional technical concept of forming pipe walls only with synthetic resin materials, and instead uses thin metal strips that have a Young's modulus (E) much higher than synthetic resin materials. It is designed to be efficiently used as a pressure-resistant deformation strength member for pipe walls.For example, rigid polyethylene has a Young's modulus (E) of 80 to 100 Kg/ ^mm2 , and rigid polyvinyl chloride has a Young's modulus (E) of 200 to 200. 250Kg/mm ² , and the Young's modulus (E) of polypropylene is 320-500Kg/mm ² , whereas for example, iron 20×10 ³ Kg/mm ² , steel and stainless steel 21×10 ³ Kg/mm ² This makes efficient use of metals with high Young's modulus (E). The technical solution is as follows. That is, it is a synthetic resin pipe with an outer tube wall formed in a spiral wave shape, and includes a spiral wave-shaped peak portion 2 forming the outer tube wall 1 and at least part of both side wall portions 3 and 4 continuous to the peak portion 2. Over the course of the process, a band plate 6A made of a thin metal plate is disposed internally on the synthetic resin wall forming the inner pipe wall, and further, at least the peak portion 2 of the synthetic resin wall forming the inner pipe wall 8 is Opposing part 8
A also has a structure in which a reinforcing strip 6B made of a thin metal plate having a width that is approximately the same as or wider than the width of the portion 8a is arranged in an interior shape so as to cover approximately the entire width of the portion 8a. It is something.

<Operation> In order to bury the pipe constructed in this manner underground, the pipe is laid along a trench excavated to a required depth at the planned pipe site, and the excavated soil is covered thereon. The installed pipe exhibits pressure resistance against earth pressure and internal pressure of the pipe, with the reinforcing strip working together with the synthetic resin wall.

<Examples> Examples of the present invention will be described below with reference to the drawings.

1 to 5 are views showing one embodiment of the present invention (hereinafter referred to as the first embodiment), and the spirally corrugated tube shown in FIG. As shown in FIG. 4, the synthetic resin band 9 is a flat band-shaped stainless steel reinforced band plate 6B made of punched metal.
A flat band body 9a is formed by integrally fusing a synthetic resin layer in the shape of a sandwich on the entire inner and outer circumferential surfaces of the flat band body 9a, and the flat band body 9a is in a state in which both side edge portions are separated by a predetermined distance as shown in FIG. It is wound in a spiral one after another while maintaining the same shape, and on the outer peripheral surface, the cross section is in the shape of a downwardly open U-shape as shown in FIG. protruding edges 6a, 6b
The peak part 2, the left and right side walls 3 and 4, and the valley part are made by fusing and integrating a synthetic resin layer in the shape of a sandwich on the entire inner and outer circumferential surfaces of the punched metal reinforcing strip plate 6A made of stainless steel plate. A corrugated band A having a structure having laterally outwardly projecting edges 5a and 5b forming a 5 is sequentially wound spirally as shown in FIG. Further, the projecting edges 5a and 5b made of only the synthetic resin material and projecting laterally outward are overlapped at the central part of the valley 5 to form a cylindrical inner wall 8 part where the flat strip body 9a does not exist. and the flat strip body 9a
It has a structure in which it is integrally fused and connected.
In this embodiment, the synthetic resin layers on both the inner and outer surfaces of the reinforcing strips 6A, 6B are integrally connected to the inner and outer surfaces through a large number of small holes 7 formed in the reinforcing strips 6A, 6B. Since the corrugated band A and the flat band 9a are integrally fused together using the synthetic resin coating, they can be firmly integrated.

Regarding the pipe shown in this example, iron strips 6A and 6B with a thickness of 0.5 mm are buried throughout the pipe wall, and the synthetic resin on the front and back is made of hard polyvinyl chloride material with a Young's modulus (E) of 250 Kg/mm ² . A 1 mm thick tube coated with 0.25 mm thick and a Young's modulus (E) of 250 Kg/mm ² for the entire tube.
Calculating the flattening load and flattening amount for a pipe made of hard polyvinyl chloride material with a thickness of 3 mm: Flattening load W = E × I × ΔY / 0.1488 × R ³ Flattening amount ΔY = 0.1488WR ³ / EI (However, , W = flat load E = Young's modulus (longitudinal elasticity coefficient) I = second moment of area (varies depending on thickness, wall thickness, shape, etc.) R = neutral axis radius) is calculated using this formula. Therefore, by substituting the values for both pipes into the above formula, with the remaining element after removing the wall thickness element from the above quadratic moment of area (), the flat load W is calculated as follows: W≒(20000×0.5′+250×0.5′)×ΔY／0
.1488×R ³ ≒10125′×ΔY／0.1488×R ^3Latter W≒250×3.0′×ΔY／0.1488×R ³ ≒750′×
ΔY/0.1488×R ³ , and the flattening amount ΔY is ΔY≒0.1488WR ³ /20000×0.5′+250×0.5′
≒0.1488WR ³ /10125′ Latter ΔY≒0.1488WR ³ /250×3.0′≒0.1488WR ³ /750
′ becomes. Therefore, since 10125:750=13.5:1, the former pipe has about 13.5 times the compressive strength and the same flat load even though the wall thickness is one-third that of the latter pipe. About 1/13.5
This results in a tube that is strong enough to resist deformation.

Therefore, since the specific gravity of iron is 7.86 and the specific gravity of PVC resin is 1.406, calculating the weight ratio of these two pipes, the former has a steel thickness of 0.5 mm and a resin thickness of 0.5 mm, and the latter has a Since the resin thickness is 3.0 mm, the former 0.5 x 7.86 + 0.5 x 1.406 = 4.633, the latter 3.0 x 1.406 = 4.218 4.633: 4.218 ≒ 1.098: 1, and the former pipe is approximately 10% heavier, but compared to the above example In the case of the pipe, the valley part 5 of the pipe wall
1 has a portion in which no metal strip is embedded, so it can be considered that the weights of both tubes are essentially the same. Further, if the flat strength of the former tube is about 10 times that of the latter tube, it can be made lighter in weight even though the flat strength is about 10 times higher. Furthermore, since the synthetic resin materials used are 0.5 mm thick for the former and 3.0 mm thick for the latter, the amount of the former tube can be approximately one-sixth that of the latter tube.

The embodiment shown in Figs. 6 and 7 is
In this embodiment, a band 9b corresponding to the flat band-shaped synthetic resin band 9a in the embodiment is extended horizontally outwardly to the left and right, including the reinforcing band 6B, and a synthetic resin layer is integrally fused to only one side (the lower side) of the reinforcing band 6B. The laterally outward extending portion made only of the synthetic resin is laminated to form a continuous cylindrical inner wall corresponding to the cylindrical inner wall 8 in the first embodiment.

On the other hand, the corrugated band B has a peak part 2 and a peak part 2.
It has a structure in which a reinforcing band plate 6A made of punched metal, which has a U-shaped cross section and is open downward, is fused and integrated on the inner surface of a part of both side walls 3 and 4 that are connected to each other, and is made only of synthetic resin material. Left and right protruding edges 5
a, 5b are wound on the flat band body 9b in an overlapping position, and are integrally fused or adhesively bonded to the flat band body 9b via an adhesive, and the left and right protruding edges 5a,
5b forms the corrugated trough 5 of the tube and constitutes a part of the cylindrical inner wall of the tube.

In the case of this embodiment, the reinforcing strips 6A and 6B are opposed within the corrugated cavity P by the synthetic resin layers 2 and 9b, which are fused and integrated on the respective outer peripheral surfaces, and the synthetic resin walls The structure is arranged like an interior.

In the embodiment shown in FIGS. 8 and 9, a reinforcing band plate 6A made of non-porous stainless steel plate with a downwardly open U-shaped cross section is provided with a mountain top 2, both side walls 3 connected to the mountain top 2, The corrugated band C, which is internalized in a sandwich-like manner in a part of the synthetic resin material of 4, is integrally fused with a synthetic resin layer on the entire lower surface and the middle part of the upper surface of the non-porous stainless steel flat reinforcing strip 6B. It has a structure in which it is fused and integrated with the upper surface of the cylindrical inner wall 8 formed by the attached band 9c, and the left and right protruding edges 5a and 5b are formed only of the synthetic resin material of the corrugated band C,
It is integrated so as to cover the outer surface of the left and right bare portions of the flat reinforcing band plate 6B.

Although the spirally corrugated tube shown in the above embodiments is shown as having an approximately right cylindrical inner surface, it is assumed that the inner wall is not necessarily a right cylindrical shape but has a somewhat uneven corrugated shape. Good too. However, since the inner wall formed in a right cylindrical shape has low fluid resistance, it is mainly used for water supply and sewer (drainage) pipes. In addition, although the spiral waveform is shown as having a rectangular cross-sectional shape, it is not necessarily intended to be limited to this shape, and it may also be a chevron-shaped or wave-shaped spiral waveform as shown in Figures 10 and 11 below. Needless to say, it's a good thing.

Next, an example will be described regarding a pressure-resistant synthetic resin pipe for underground burial, which is mainly used as a protection pipe for electric wires, telephone lines, etc.

The embodiment shown in FIG. 10 and FIG.
As shown in Fig. 1, the reinforcing strip plate 6A having a chevron-shaped cross-sectional shape is coated with a synthetic resin layer in the form of a sandwich trench on its entire inner and outer circumferential surfaces, as in the embodiments shown in Figs. 8 and 9. The coated corrugated band D is obtained by covering both the inner and outer surfaces of the flat reinforcing band plate 6B with a synthetic resin material in the shape of a sanderch, and forming a particularly thick protrusion 9e on one end of the inner surface. It is wound spirally on the cylindrical inner wall 8 formed by the band 9d, and the left and right lateral outward protruding edges 5a, 5b of the band D are wound spirally on the cylindrical inner wall 8 formed by the band 9d.
It has a structure in which these are polymerized and fused together.

Therefore, the tube of this embodiment has protrusions 9e on the inner surface of the tube.
A tube is obtained in which... is formed.

When inserting an electric wire, etc. into a tube having such a structure, the electric wire, etc. is supported only on the inner circumferential surface of the protrusion 9e, so the friction area between the inner circumferential surface and the electric wire, etc. is small. This has the advantage that the work of inserting electric wires etc. can be done easily.

In the embodiment shown in FIG. 12, reinforcing strips 6A, 6
This figure shows the plate material 6a forming B. When the reinforcing band plate 6 according to the present invention is made of a material having a corrugated shape in the direction orthogonal to the longitudinal direction of the band, it will have a flat plate shape. It is possible to obtain a tube with even greater pressure resistance and deformation strength than in the case of other materials.

In addition, in the embodiment, a punched metal thin stainless steel plate was described as the material for the reinforcing strip 6, but a steel plate or other strength material may also be used. It may be a plate material in which no punched holes are formed. Furthermore, the shape, size, and density of the punched holes are matters that can be set arbitrarily, and there is no intention to specify them.

In addition, the synthetic resin materials that form the pipe walls include:
Olefin-based synthetic resins such as polyethylene and polypropylene and vinyl chloride-based synthetic resins are mainly used, but it goes without saying that other synthetic resins may also be used.

Although the embodiments considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the structures of these embodiments. It can be implemented with appropriate modification within the scope of achieving the following effects.

<Effects of the invention> As described above in detail in the description of the embodiments and as described in the section of means for solving the problems, the present invention provides a reinforcing structure for pipes used as reinforcing materials using wire rods, etc. It is not a reinforcing material that uses a wide metal plate, but a spiral corrugated plate that is continuous as a reinforcing material over the top of the spiral waveform that forms the outer tube wall and at least part of the side walls that follow the top of the spiral waveform. In addition, at least a portion of the inner wall portion of the tube facing the mountain top portion is provided with a reinforcing strip made of a thin metal plate having a width approximately equal to or greater than the width of the portion 8a. Since the reinforcing material has a continuous width and is disposed so as to cover almost the entire width of the portion 8a, and is placed inside and surrounded by the synthetic resin wall, it can be used not only for external pressure but also for external pressure. It is possible to obtain a synthetic resin pipe that is extremely strong even against internal pressure, and even if this reinforcing member is made of a fairly thin material, it can exhibit a sufficient reinforcing effect. Although it can be made quite thin and uses a thin metal plate as a reinforcing member, the overall weight of the pipe is reduced and it is convenient for transportation and handling, and the use of synthetic resin material. This has the remarkable effect that it is possible to provide the market with underground pipes that are inexpensive and can withstand long-term use by reducing the amount of pipes.

[Brief explanation of the drawing]

1 to 3 are views of a first embodiment of the present invention, and FIG. 1 is a partially cutaway front view of a tube;
Fig. 2 is a longitudinal sectional view of the main part, Fig. 3 is an exploded explanatory view of the main part, Fig. 4 and Fig. 5 are perspective views showing one embodiment of the reinforcing strip plate, Fig. 6 and Fig. 8 respectively. and 10th
The figures are longitudinal sectional views of main parts showing different embodiments,
7, 9, and 11 are exploded explanatory views of FIGS. 6, 8, and 10, respectively; FIG. 12 is a perspective view showing an example of the reinforcing band material; and FIG. 13. 1 is a vertical sectional view of main parts showing a conventional structure. In the figure, 1 is an outer tube wall, 2 is a mountain top, 3 and 4 are side wall portions, 6A and 6B are reinforcing strips, 8 is an inner tube wall, and 8a is a portion facing the mountain top.

Claims (1)

[Claims for Utility Model Registration] A synthetic resin pipe for underground burial with an outer pipe wall formed in a spiral wave shape, including a peak portion 2 of the spiral waveform forming the outer pipe wall 1 and both sides connected to the peak portion 2. A reinforcing strip 6A made of a thin metal plate having a continuous width is disposed inside the synthetic resin wall forming the pipe wall over at least a portion of each of the wall portions 3 and 4, and further At least a portion 8a of the synthetic resin wall forming the inner tube wall 8 facing the mountain top portion 2 is also provided with a reinforcing band plate 6B made of a thin metal plate having a width approximately equal to or greater than the width of the portion 8a. , a pressure-resistant synthetic resin pipe for underground burial, which is arranged internally so as to cover substantially the entire width of the portion 8a. Pressure-resistant synthetic resin for underground burial according to claim 1, wherein reinforcing strips 6A and 6B made of metal thin plates embedded in the synthetic resin wall are adhered to a synthetic resin material covering them. tube. Underground according to the scope of the utility model registration claim, in which reinforcing strips 6A and 6B made of thin metal plates embedded in the synthetic resin wall are in close contact with the synthetic resin material covering them, but are not bonded. Pressure-resistant synthetic resin pipe for burial. The pressure-resistant synthetic resin pipe for underground burial according to claim 1, wherein the synthetic resin material is olefin-based or vinyl chloride-based. The pressure-resistant synthetic resin pipe for underground burial according to claim 1, wherein the spiral waveform is a waveform with a rectangular cross section. The pressure-resistant synthetic resin pipe for underground burial according to claim 1, wherein the spiral waveform is a waveform with an arcuate cross section.