JPH05332479A - Corrugated sleeve - Google Patents

Abstract

PURPOSE:To carry out bending with a small radius of curvature by reducing the bending rigidity from both the edge parts toward the center part by forming each corrugated sleeve from the installation parts at both the edge parts and the corrugated part at the center part and setting the wave shape of the corrugated part to a specific pattern. CONSTITUTION:A corrugated sleeve 10 is installed as buffer pipe outside a corrugated pipe 12 for an electric wire protecting pipe, and embedded into a concrete wall 14. In this case, the corrugated sleeve 10 is formed from each installation part 16 at both the edge parts, central corrugated part 18 at the center part, and an intermediate corrugated part 20 at the intermediate part therebetween. The wave form of each corrugated part 18, 20 is formed from one or the combination of both, i.e., the pattern in which the pitch of the waves reduces gradually or stepwise from both the edge parts towards the center part and the pattern in which the height of the wave increases gradually or stepwise from both the edge parts towards the center part. Accordingly, the bending rigidity is reduced from both the edge parts of the corrugated sleeve 10 toward the center part, and bending is carried out with a small radius of curvature.

Description

Detailed Description of the Invention [Industrial application]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrugated sleeve, and more particularly, it is a corrugated sleeve consisting of a relatively short mounting portion provided at both ends and a corrugated portion in the middle thereof so that it can be bent with a small radius of curvature. Relates to a corrugated sleeve.

[0002]

2. Description of the Related Art A corrugated sleeve utilizes its flexibility to bend a pipe, connect rigid or flexible pipes to each other, and connect a flexible electric wire protection pipe to a concrete structure. It is used for various purposes including parts. For example, flexible resin corrugated sleeves are used in the bent parts of the pipes because of their good workability and the need to maintain the bent shape, or the ends of the pipes to be connected are connected to each other. A flexible corrugated sleeve is required to adjust the positional deviation between the parts. In addition, although the synthetic resin corrugated pipe that is generally used as a flexible electric wire protection pipe is flexible, it requires high mechanical strength because of its use, so a small radius of curvature is required. If it needs to be bent, it cannot be adapted. In such a case, it is necessary to use a corrugated sleeve that bends with a small radius of curvature in the bent portion.

In particular, when a corrugated pipe and a structure are connected, for example, when a corrugated pipe made of synthetic resin buried in the ground is connected to a concrete structure or the like, in a region where ground subsidence is remarkable, Is unequal subsidence between the synthetic resin corrugated pipe and the concrete structure, so the synthetic resin corrugated pipe will sink more than the concrete structure (and vice versa). In the connection portion between the corrugated pipe and the concrete structure, a large stress is generated in the synthetic resin corrugated pipe, and the synthetic resin corrugated pipe is often locally deformed and further broken. In such a case, in order to buffer the transmission of stress due to unequal settling to the synthetic resin corrugated pipe, it is suitable for the outside of the synthetic resin corrugated pipe at the embedded connection between the synthetic resin corrugated pipe and the concrete structure. A construction method as shown in FIG. 2 (b) in which a simple sleeve is covered as a sheath tube and embedded in a structure is adopted. A synthetic resin sleeve used as a sheath tube in such a case is generally called a buffer pipe.

[0004]

However, the conventional corrugated sleeve cannot be bent with a desired small radius of curvature because its bending rigidity is greater than its radius and it is difficult to bend. In particular, the conventional buffer pipe is a smooth, non-corrugated pipe type as shown in FIG. 2 (b), which cannot be freely deformed due to its large bending rigidity, and a small deformation causes a large stress to easily occur. Tended to destroy. Therefore, when time passes after construction and the ground subsides compared to the time of construction,
In the mounting portion between the synthetic resin corrugated pipe and the buffer pipe and the concrete structure, the conventional buffer pipe is extremely deformed and easily crushed or destroyed, and thus the synthetic resin corrugated pipe and the concrete structure. It often happened that the deformation due to unequal subsidence between and could not be alleviated and the stress was transmitted to the synthetic resin corrugated pipe as it was, and the synthetic resin corrugated pipe was broken.

In view of such a problem, an object of the present invention is to provide a corrugated sleeve which has a bending rigidity smaller than a radius and can be easily bent with a desired small radius of curvature, particularly when used as a buffer pipe in an area where ground subsidence is remarkable. An object of the present invention is to provide a corrugated sleeve having a structure that does not easily follow the uneven settlement and is not destroyed.

[0006]

As a result of experiments and studies, the present inventor has found that the bending rigidity of the center portion of the corrugated sleeve is smaller than that of the other portions so that the sleeve has a smaller radius of curvature, that is, a shorter sleeve. We have found that the length can be changed so that it can change direction significantly. Based on this finding, in order to achieve the above-mentioned object, the corrugated sleeve according to the present invention comprises a relatively short mounting part provided at both ends and a corrugated part in the middle thereof. The mold has a pattern in which the pitch of the waves decreases from both directions toward the center from the mounting portion gradually or stepwise or in a combination of both, and the wave height of the waves gradually increases from both directions toward the mounting portion toward the center. It is characterized in that it is formed by any one of a pattern that increases gradually or stepwise or in the form of a combination of both, and a pattern of a combination of both a pitch pattern and a wave height pattern. ..

The central portion of the corrugated portion has a smaller pitch and / or a larger wave height than the other portions, so that the central portion of the corrugated portion has a bending rigidity smaller than that of the other portions by providing corrugated waves. Therefore, the entire corrugated sleeve can be largely bent with a small radius of curvature. For example, even when the ground at the place where the corrugated sleeve according to the present invention is used as a buffer pipe is unevenly submerged, such a corrugated sleeve is deformed following the uneven subsidence of the ground and is destroyed by local stress. It will not be done.

To further explain, the corrugated pipe 12 made of synthetic resin, which is covered with the corrugated sleeve according to the present invention as a buffer pipe,
As shown in Fig. 4, the concrete manhole 14 after construction
In contrast, when S is sunk, one end of the corrugated sleeve 13 at the connection with the concrete wall is not bent because it has a large bending rigidity and is supported by the concrete wall 14. Further, since the wave height of the corrugated sleeve 13 increases from the connecting portion with the concrete wall toward the center, the bending rigidity becomes small, and therefore the bending becomes large (the curvature becomes small), and when passing the central portion. , The bend gradually becomes smaller, and finally reaches the buried level of the synthetic resin corrugated pipe for electric wire protection pipe, extends flat in the same way as the synthetic resin corrugated pipe, and breaks due to extreme bending Can be prevented.

The corrugated sleeve according to the present invention is formed of a flexible material, for example, plastic, metal or the like according to its application, but it is preferably made of plastic which is easy to mold and is extrusion molded. It is manufactured by blow molding or the like.
The mounting portions at both ends of the corrugated sleeve are configured so as to be connected by being covered on the outside of a rigid pipe or a flexible synthetic resin corrugated pipe, or welded to the pipe or corrugated pipe. However, there is no particular limitation as long as it is smooth or corrugated as long as it can be connected to the pipe or corrugated pipe to be connected. When the corrugated sleeve is used as a buffer pipe, one of the mounting portions of the corrugated sleeve is embedded in the wall of a concrete structure or the like. Also in this case, the mounting portion may be smooth or corrugated, and preferably has a large bending rigidity. The size of the pitch and the wave height, the degree of the gradual decrease of the pitch, and the degree of the gradual increase of the wave height can be appropriately selected depending on the diameter and the thickness of the corrugated sleeve. Hereinafter, the present invention will be described in more detail based on examples with reference to the accompanying drawings.

[0010]

【Example】

Example 1 A corrugated sleeve 10 of Example 1 according to the present invention has an overall length of 100 cm, and has smooth mounting portions 16 at both ends, a central corrugated portion 18, and an end portion 16. And an intermediate corrugated portion 20 intermediate the central corrugated portion 18 and made of impact-resistant hard vinyl chloride resin. The dimensions and mechanical properties of each part are shown in the following table.

Mounting portion 16 Intermediate corrugated portion 20 Central corrugated portion 18 Shape dimension Length mm 50 225 400 Inner diameter mm 70 70 70 Wall thickness mm 4.0 4.0 4.0 Pitch mm ─ 16.5 16.5 Wave height mm ─ 2.0 5.1 Young's modulus kg / cm ² 300 300 300 Poisson's ratio 0.3 0.3 0.3 Bending rigidity kgfm ² 500 100 15

The corrugated sleeve 10 of Example 1 was applied to a buffer pipe and its performance was evaluated. FIG. 1 (a) shows a corrugated pipe 12 made of hard polyethylene for a wire protection pipe having a nominal diameter of 50 mm.
The corrugated sleeve 10 made of polyethylene of Example 1 is used as a buffer pipe on the outside of the concrete wall 14 of the concrete structure.
It shows a state in which it is embedded and connected. The polyethylene corrugated pipe covered with the corrugated sleeve 10 of Example 1 was subjected to a shape deformation test as follows, and the performance of the corrugated sleeve 10 of Example 1 was evaluated according to the degree of shape deformation of the polyethylene corrugated pipe. evaluated. That is, the smaller the deformation of the polyethylene corrugated pipe, the greater the cushioning effect of the corrugated sleeve and the higher the performance. In the shape deformation test of the polyethylene corrugated pipe, in order to simulate unequal settlement, first, the portion of the polyethylene corrugated pipe 12 is set to a settlement rate of 10 cm /
It was submerged in 2 minutes to make the subsidence 10 cm. Next, a test ball was threaded to determine the degree of deformation of the polyethylene corrugated tube 12 when the subsidence amount reached 10 cm.

The test ball threading is the deformation of the corrugated tube 12 by successively passing test balls having different diameters in order from the small diameter to the large diameter through the corrugated tube and confirming the maximum diameter of the test ball that can be passed. It is a method of measuring the degree. In other words, if the ratio of the maximum diameter of the test sphere that can pass and the original diameter of the corrugated tube is large, the degree of deformation of the corrugated tube is small. After the completion of the test ball threading at a sinking amount of 10 cm, the test ball threading was further performed under the same conditions for 10 cm, and the test ball threading was repeated every 10 cm of the sinking amount. After the test was completed, the appearance of the corrugated sleeve 10 of Example 1 used in the test was observed.

The measurement result is as shown in FIG.
In Fig. 3, the horizontal axis represents the subsidence amount (cm) of the corrugated pipe against the concrete wall, and the vertical axis represents the maximum passage diameter of the test sphere that passed through the corrugated pipe at the subsidence ratio as a ratio to the diameter of the corrugated pipe. It is displayed. Therefore, it is shown that the deformation of the corrugated pipe is smaller as the ratio is larger for the same subsidence amount of the corrugated pipe. The marks in the graph show calculated values based on the respective measured values. As a result of observing the appearance of the corrugated sleeve 10 of Example 1 that was subjected to the test, some deformation was observed in the smooth portion on the concrete wall surface side. Examples 2 and 3 described below
Was the same.

Example 2 The corrugated sleeve 40 of Example 2 is a corrugated tube made of impact-resistant hard vinyl chloride resin and having a length of 100 cm and an inner diameter of 70 mm, and the whole has a length of 50 mm at both ends. It is composed of a smooth mounting portion 42, a central corrugated portion 44 having a length of 500 mm, and an intermediate corrugated portion 46 having a length of 225 mm intermediate between the end portion 42 and the central corrugated portion 44. The intermediate corrugated portion 46 has a corrugated shape with a pitch of 30 mm and a wave height of 7 mm, and the central corrugated portion 44 has the same wave height as the intermediate corrugated portion 46, but the pitch is as small as 10 mm. Corrugated sleeve 4 of Example 2
Its performance was evaluated using 0 as a buffer pipe. Fig. 1 (b) shows a corrugated tube 12 for wire protection tube with a nominal diameter of 50 mm.
A corrugated sleeve 40 of the second embodiment as a buffer pipe on the outside of the
Is used and is embedded and connected to the wall 14 of the concrete structure. The corrugated tube 12 covered with the corrugated sleeve 40 of Example 2 was passed through a test ball in the same manner as in Example 1, and the results are shown in FIG.

Example 3 The corrugated sleeve 50 of Example 3 is a corrugated tube made of impact-resistant hard vinyl chloride and having a length of 100 cm and an inner diameter of 70 mm, and is entirely smooth at both ends at a length of 50 mm. Na mounting part 5
4, a central corrugated portion 56 having a length of 500 mm, and an intermediate corrugated portion 58 having a length of 225 mm between the end portion 54 and the central corrugated portion 56.
It consists of and. The wavy portion 58 of the intermediate wave is 1
Formed with a pitch of 6.8 mm and a wave height of 5.9 mm, the central corrugated portion 56 has a pitch that gradually decreases from the transitional portion with the intermediate corrugated portion 58 toward the center to 10.0 mm, and the corrugated height is Gradually increases toward the center to 9.4 mm. The performance was evaluated by using the corrugated sleeve 50 of Example 3 as a buffer pipe. In Fig. 1 (c), the nominal diameter is 5
It shows a state in which the corrugated sleeve 50 of the third embodiment is covered on the outer side of the corrugated pipe 12 for electric wire protection pipe of 0 mm and is embedded and connected to the wall 14 of the concrete structure via the joint 52. The corrugated tube 12 covered with the corrugated sleeve 50 of Example 3 was passed through a test ball in the same manner as in Example 1, and the result is shown in FIG.
It was shown to.

Conventional Examples 1 and 2 In order to compare with the performance of the corrugated sleeve according to the present invention, an example in which a buffer pipe is not used is referred to as a conventional example 1, and a conventional smooth sleeve is used as a buffer pipe. As Example 2, a shape deformation test was performed on the corrugated pipe in the same manner as in Example 1. FIG. 2 (a) shows a corrugated pipe 12 for a wire protection pipe having a nominal diameter of 50 mm without a buffer pipe and a wall 1 of a concrete structure.
2 shows a state in which it is embedded and connected, and FIG. 2 (b) shows a conventional smooth sleeve 60 having a length of 1 m and a nominal diameter of 65 mm with a nominal diameter of 50 mm.
It is used as a buffer pipe on the outside of the corrugated pipe 12 for electric wire protection pipe of mm, and is shown embedded in the wall 14 of the concrete structure. The sleeve of Conventional Example 2 is made of steel.
The corrugated tubes of Conventional Example 1 and Conventional Example 2 were passed through a test ball in the same manner as in Example 1, and the results are shown in FIG. The corrugated pipe used in Conventional Example 1 was completely buckled with the concrete wall surface, and in the corrugated pipe used in Conventional Example 2, the corrugated pipe was extremely bent at the outlet of the buffer pipe.

As is apparent from FIG. 3 and the results of the appearance inspection of the corrugated pipes used in the test, the corrugated sleeve of the embodiment has a deformation of the synthetic resin corrugated pipe at the same sinking amount as compared with the conventional example. It has the effect of reducing the degree of, and fully fulfills the function of a buffer pipe. This is because, in the corrugated sleeve of the embodiment, the bending rigidity in the central portion of the corrugated portion is smaller than that in the other portions, so that it is possible to easily follow uneven settlement.

[0019]

According to the present invention, the corrugation of the corrugated portion of the corrugated sleeve is made such that the pitch of the corrugation is made smaller toward the center of the corrugated sleeve, or the corrugation height is made larger, or both of them are combined. With the corrugated shape, the bending rigidity becomes smaller from the end to the center, and it is possible to bend with a small radius of curvature. If the corrugated sleeve according to the present invention is used as a buffer pipe, it is easily deformed by following uneven settlement of the ground at the connection portion with the structure, buffering local stress and extreme deformation or It has the effect of preventing destruction.

[Brief description of drawings]

1 (a), 1 (b) and 1 (c) each show a state in which a corrugated sleeve of a different embodiment according to the present invention is used as a buffer pipe to cover the corrugated pipe outside and to be embedded and connected to a concrete wall. FIG. 4 is a partial cross-sectional explanatory view showing

FIG. 2 (a) is a partial cross-sectional explanatory view showing a state in which a corrugated pipe is directly embedded and connected to a concrete wall without using a buffer pipe, and FIG. 2 (b) shows a smooth sleeve. It is a partial cross-sectional explanatory view showing a state in which the corrugated pipe is covered on the outside as a buffer pipe and is embedded and connected to a concrete wall.

[Fig. 3] The horizontal axis represents the subsidence amount (cm) of the corrugated pipe against the concrete wall, and the vertical axis represents the ratio of the maximum passage diameter of the test ball passing through the corrugated pipe to the diameter of the corrugated pipe. Shows the graph displayed in.

FIG. 4 shows a deformed state of the buffer pipe according to the present invention on the unequal deposition substrate.

[Explanation of symbols]

 10, 40, 50 Corrugated sleeve according to the present invention 12 Corrugated pipe 14 Concrete wall 16, 42, 54 Mounting portion 18, 44, 56 Central corrugated portion 20, 46, 58 Intermediate corrugated portion 60 Smooth sleeve

Claims (1)

[Claims] 1. A corrugated part of the corrugated part, which has relatively short mounting parts provided at both ends and a corrugated part in the middle of the mounting part, has a wave pitch from both directions from the mounting part toward the center. A pattern that decreases gradually or stepwise or in a combination of both, and a wave height of the wave increases gradually from both directions from the mounting part toward the center in both directions or gradually or stepwise or a combination of both. The corrugated sleeve, wherein the corrugated sleeve is formed by any one of the following pattern and a pattern in which both the pitch pattern and the wave height pattern are combined.