JPH10226555A - Cable protecting tube holder, its production and structure of cable protecting tube connecting part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an inexpensive, lightweight (<=1 sp.gr.) and easy-to-handle cable protecting tube holder by which electric cables are more easily embedded in the ground, the application is facilitated and the term of works is shortened and to easily release the heat generated in the tube into the ground. SOLUTION: This cable protecting tube holder 1 is produced by mixing 100 pts.wt. of a lightweight inorg. aggregate having 0.4-6mm grain diameter, 30-50 pts.wt. of inorg. cement, 0.5-5 pts.wt. of a synthetic-resin emulsion as solid and water in 0.55-0.75, preferably 0.6-0.7, weight ratio of the water to inorg. cement and shaping the mixture. One or plural cable protecting tubes 2 arranged in a line are vertically held in the holder, a semicircular-sectioned recessed groove is provided on upper face and/or the lower face, and the whole forms a rectnagular parallelepiped. The structure of the cable protecting tube connecting part is obtained by forming a tube connecting part 3 between the end faces of the holders separated from each other, covering the connecting part with a sheet material holding a fluid packing such as sand, and the packing is filled in the connecting part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube holder for holding a cable protection tube used when a power / communication cable or the like is buried underground, a method of manufacturing the same, and a structure of a connection portion of the cable protection tube. .

[0002]

2. Description of the Related Art Conventionally, a cable protection tube having a plurality of cable insertion holes as cable burying means has been proposed (see Japanese Utility Model Application Laid-Open No. 54-140297). According to this, a plurality of cable insertion holes 2 are formed between both ends of a rectangular parallelepiped protective tube made of a material such as a unit length ceramic.
1 are penetrated, and a plurality of these are connected to form a long pipe. In such a cable protection tube,
It was heavy, inflexible, vulnerable to vibrations such as earthquakes, and the connection was not sufficiently sealed. Therefore, the present inventors can assemble a cable protection tube and a rectangular parallelepiped foam holding the protection tube so as to be light and easy to handle, easy to perform construction, and sufficient for measures against water leakage and the like. A unit was proposed (see Japanese Patent Application No. 7-269153).

[0003]

However, when heat is generated as in the case of a power cable, it is necessary to release the generated heat as much as possible. Techniques sufficient to solve the problem in heat transfer have been proposed. Did not. Therefore, an object of the present invention is to provide an inexpensive, lightweight (specific gravity of 1 or less), easy to handle, easy to construct, shorten the construction period, and protect cables to promote the underground of electric wires. The purpose is to allow the heat generated in the tubes to escape easily into the ground.

[0004]

Means for solving the problems of the present invention is to add water and a binder to a lightweight aggregate, mix them,
The lightweight aggregate is moistened, the inorganic cement is added to and mixed with the lightweight aggregate, and the inorganic cement is made to react with the surface water held by the lightweight aggregate, thereby forming a cable protection tube holder having a high porosity. There. If this cable protection tube holder is used, the specific gravity during handling will be 1 or less,
The heat transfer coefficient is required to release the heat generated from the power cable due to the fact that the water content is reduced to about 1/2 or less of that of ordinary concrete products, and that the moisture in the ground penetrates into the voids in the pipe holder. Was able to be. In the structure of the cable protection tube connecting portion of the present invention, a pipe connecting portion is formed with an interval between the end faces of the cable protection tube holding body, and the connection portion is covered with a sheet material holding a fluid filler such as sand. And the connecting portion is filled with the filler.

[0005] The inorganic cement used in the present invention includes all inorganic cements which harden by reacting with water, such as gypsum cement, or by reacting with water and carbon dioxide, to increase the strength. As the lightweight inorganic aggregate, an inorganic aggregate having a specific gravity of 1 or less, such as pumice, perlite, vermiculite, foamed glass beads, and foamed shirasu, is used.
The compounding amount of the inorganic cement is in the range of 35 to 50 parts by weight based on 100 parts by weight of the lightweight inorganic aggregate. If the amount is less than 35 parts by weight, the strength is insufficient, and if the amount is more than 50 parts by weight, the specific gravity increases, and the workability deteriorates. As the synthetic resin emulsion, an emulsion such as an acrylic resin, a vinyl acetate resin, a urethane resin, or a styrene butadiene copolymer is used.

The compounding amount of the synthetic resin emulsion is calculated by converting the solid content to 100 parts by weight of the above-mentioned lightweight inorganic aggregate.
It is used in the range of 0.5 to 5 parts by weight, preferably 1 to 4 parts by weight. If the amount is less than 0.5 part by weight, the strength is insufficient, and if the amount is more than 5 parts by weight, the cost only increases but the strength does not increase much. The amount of water (including the amount of water in the emulsion) is such that the weight ratio of water / inorganic cement is in the range of 0.55 to 0.75, preferably 0.6 to 0.7. If it is less than 55%, the amount required to adhere the inorganic cement to the surface of the aggregate is insufficient, and the strength of the product is insufficient. If it is more than 75%, the inorganic cement flows after the inorganic cement is fluidized and filled into the mold. Insufficient product strength.

As a compounding agent other than the above, reinforcing fibers are appropriately used, and inorganic or organic fibers are used as reinforcing fibers, thereby adding strength (bending strength, tensile strength, compressive strength, etc.) to the finished product. ,Strengthen. For example,
Glass fiber, ceramic fiber (alumina, silica, etc.), metal fiber, carbon fiber, rock wool, synthetic polymer fiber (olefin, nylon, vinylon, aramid, etc.), natural fiber (manila hemp, bagasse, cotton, jute) , Wood fiber). In particular, when glass fibers are used, it is preferable to perform pretreatment for imparting durability to alkalinity or use alkali-resistant glass. Further, it is preferable that the length / width ratio (aspect ratio) of the fiber is in a range of at least 10: 1. Further, a net (a wire net or an aramid fiber mesh) made of these fibers, a woven fabric, a nonwoven fabric, or the like may be integrally formed in or on the product.

[0008]

FIG. 1 is a perspective view showing a tube holder 1 holding a cable protection tube 2. The tube holder 1 is an upper tube holder 1-1.
And a lower tube holder 1-2. The pipe holding part 1 is not covered on the pipe connection part of the cable protection pipe 2. Therefore, the wall thickness of the tube holder 1 can be determined without considering the projecting portion such as the seal portion, and the weight can be reduced accordingly. FIG. 2 is a perspective view showing the upper tube holder 1-1 and the lower tube holder 1-2. 1-3 is an upper recess, and 1-4 is a lower recess. The cable protection tube 2 is formed so as to fit therein. FIG. 3 shows the connection in a cross-sectional view. Reference numeral 3 denotes a pipe connection part, and reference numeral 4 denotes a rubber ring for sealing. Pipe connection 3
Thereby, the connection of the cable protection tube 2 is adjusted. 2-1
Is an adjustment interval for adjusting the interval between the pipe connection portions 3 and the interval between the pipe holders 1.

FIG. 4 shows the parallel pipe holder 5 in a perspective view.
5-1 is an upper parallel pipe holder, and 5-2 is a lower parallel pipe holder. FIG. 5 shows a process of forming the tube holder 1. FIG. 6 shows a compression test method performed in the process of determining the material of the tube holder 1 and in which the sample 8 was formed into a rectangular parallelepiped shape.
7-1 is an upper compression plate, and 7-2 is a lower compression plate. FIG.
2 shows a compression test method performed on the product shape of the tube holder 1. 7-1 is an upper compression plate, and 7-2 is a lower compression plate. The cable protection tube 2 was inserted between the upper tube holder 1-1 and the lower tube holder 1-2. FIG. 8 is a view showing a structure in which the upper tube holding member 1-1 and the lower tube holding member 1-2 are connected more reliably, and furthermore, in order to improve the efficiency of releasing the heat generated in the cable protection tube 2 to the outside, the upper tube holding member 1-1 and the lower tube holding member 1-2 are connected. The figure shows that a flexible rubber magnet sheet and a flexible rubber sheet containing iron powder are fixed to a portion where the holding body 1-1 and the lower tube holding body 1-2 are in contact with each other. FIG.
This shows a tube holder 1 in which a net 6 made of a wire mesh or other material is incorporated. The size of the mesh was larger than the maximum particle size of the aggregate.

FIG. 10 is a front view showing a state of a connection portion of the cable protection tube in the process of burying the power or communication cable protection tube 2 underground or the like. The connecting tool or connecting portion 18 of the stake 11, the holding plate 12, the strip 17 and the plate-like holding tool 19 are indicated by two-dot chain lines (virtual lines). The width of the sheet material 13 made of a water-permeable sheet material such as a woven fabric or a nonwoven fabric or a plastic film is almost the same as that of the holding plate 12. These sheet materials did not allow the sand or the like to be filled to pass through. When the sheet material such as the plastic film is impervious to water, the sheet material seals the pipe connection portion 3 and performs a waterproof function. FIG. 11 is a sectional view of the connection portion. A strip 17 such as a metal band or a wire is placed on the ground 15 where the pipe connection section 3 is to be located, a sheet material 13 is laid thereon, and the pipe holder 1 and the cable protection pipe 2 are placed thereon as shown in FIGS. 11, the sheet material 13 and the strip 17 are placed on the bundle of pipe holders 1, the pile 11 is driven in, the holding plate 2 is sandwiched between the sheet material 13 and the pile 11, and a wedge is formed. Holding plate 1
2 is pressed against the tube holder 1.

The upper sheet material 13 is opened, and a fluid filler 14 such as sand (hereinafter referred to as sand 14) is charged into the pipe connection portion 3, and the sand 14 is placed below the cable protection tube 2. To ensure proper filling. When filling is completed, sheet material 1
3 is closed and overlapped as shown in FIG. 11, a plate-shaped holding member 19 is placed on the overlapped portion, and a connecting member or connecting portion 18 is positioned thereon, so that a band such as a wire or a band is provided. The strips 17 are connected and tightened. If the holding plate 12 and the pile 11 are removed, they can be used for other purposes, but they need not be removed. The holding plate 12 does not need to be particularly removed as long as the holding plate 12 is, for example, in a lattice shape so that water can pass therethrough. The pile 11 does not need to be particularly removed. Next, fill the entire trench for construction with sand for backfilling,
Compact. Removal of the stake 11 and the holding plate 12 is as follows.
This may be performed in the process of backfilling. Since the pipe connection portion 3 is covered with the sheet material and filled with the fluid filler 14 such as sand as described above, the elasticity and flexibility characteristic of the rubber ring type receptacle can be maintained, so that the vibration resistance is improved. It can be a pipe connection part with.

FIG. 12 is a front view showing a state of a connecting portion of the cable protection tube in the process of embedding the power cable protection tube 2 underground or the like in another embodiment. FIG.
Is a sectional view of the connection portion. In this embodiment, the pile 1
It is a method that does not hit 1. A strip 17 such as a band or a wire on the ground 15 where the pipe connection portion 3 is to be located;
20, a sheet material 13 is spread thereon, and a pipe holder 1 and a cable protection tube 2 are arranged thereon as shown in FIGS. 12 and 13, and upper end portions of the sheet material 13 and the strip 17 are provided. Is placed on the bundle of tube holders 1. The grid-like holding plate 12 is arranged at a position as shown in FIGS.
The strip 20 is lifted from the outside of the sheet 2, and the pressing plate 12 is pressed against the sheet material 13, and connected and fastened by the connecting tool or the connecting portion 21. The sheet material 13 is opened upward to be opened, and sand or the like 14 is put into the pipe connection portion 3 so that the sand or the like 14 is properly filled also under the cable protection tube 2.

When the filling is completed, the sheet material 13 is closed and overlapped as shown in FIG.
For example, as shown in FIG. 11, a plate-shaped holding member 20 is placed, and the band members 17 are connected and fastened so that the connecting member 18 is positioned thereon. If the holding plate 12 is removed, the holding plate 12 can be used for other purposes. The holding plate 12 does not need to be particularly removed as long as the holding plate 12 is, for example, in a lattice shape so that water can pass therethrough. Next, the trench for the construction is backfilled. The holding plate 12 may be removed during this backfilling process. According to this method, the work is easier because there is no need to drive the pile. As the sand, mountain sand having a particle size of 0.05 mm to 4.00 mm was used. Some gravels (20 mm or less) may be included. Also, sodium silicate (water glass) used as a soil hardening agent in soft ground may be used in combination to harden the sand to help control runoff.

According to the present embodiment, in which the pipe connecting portion 3 is not covered with the pipe holding member 1 and is surrounded by a sheet material 13 and is filled with sand or the like 14, the pipe connecting portion 3 forms a pipe line. It is easy to adjust the interval, and even in the case of partial replacement of the pipeline, the work can be simplified by opening the sheet material 13 and removing the sand 14 or the like. Even if the pipe is bent at the pipe connection part 3, it can be easily handled. Table 1 shows the basic compounding ratios of the materials used in this example in terms of weight ratios. Table 2 shows the range of the mixing ratio per 100 parts by weight of the aggregate.

[Table 1]

[Table 2] The particle size of the pumice used as the aggregate was A group (10.0
~ 6.0mm, average 8.5mm), B group (2.4 ~
4.7mm, average 4.0mm), C group (1.2-2.
4mm, average 2.0mm), D group (0.4-1.4m)
m, average 1.0 mm), E group (0.1-0.4 mm,
(0.3 mm on average).

These pumice stones may be used alone or as a mixture (weight ratio 1:
1) Used and tested. A rubber tip was added to improve the elasticity. In the basic formulation, as shown in FIG. 5, an acrylic resin emulsion and water were added to the aggregate and stirred for 5 to 7 minutes. Powdered cement was added in a state where surface water was present in the aggregate (a state where the surface was wet), and the mixture was further stirred for 3 to 5 minutes, filled in a mold, and compressed with an upper mold. The mold may be metal, FRP or wood. In order to maintain a proper water ratio, for example, in the case of a wooden mold, the inside of the mold was painted so that the wooden mold did not absorb water, or a plastic film or the like was stuck in the mold. As a result, the surface condition of the product was improved, the releasing effect was improved, and the release was facilitated. It was compacted in a mold, cured at room temperature for 8 hours or more, and then cured in an oven (50 ° C.) for a whole day and night. Next, the product was removed from the mold, and the product was dried in an oven (50 ° C.). It was easily ascertained that the voids in the product thus formed were continuous due to water absorption and the like.

A pressure resistance test was performed using a block-shaped product. The test was performed at 10 mm / mi as shown in FIG.
Loaded at speed n. The process was terminated when the sample cracked. The specific gravity of each sample is displayed together. Table 3 shows the results.

[Table 3] From the test results, when the aggregate of Group A having the largest particle size is used alone, the specific gravity is small at 0.50, but the cracking stress is extremely low at 2.8 kgf / cm2, and the particle size is small. When the smallest aggregate of Group E was used alone, the crack stress was large at 45.2 kgf / cm @ 2, but the specific gravity was greater than 1 and 1.15. Group D
Cracking stress 36.1 kgf / cm2, specific gravity lower than 1.
86, and the thermal conductivity was 0.127, which was relatively high.

Therefore, when an experiment was carried out for each of the groups B and C, B and D, and C and D (by weight ratio: 1: 1), it was found that B and D had the highest cracking stress. It was 42.3 kgf / cm2 in the mixed product, which was almost the same as 45.2 kgf / cm2 in the E group. Further, the thermal conductivity was the highest at 0.136 W / mK, which was almost the same as that of the E group at 0.140 W / mK, but the specific gravity was 0.10 W / mK.
82 was 1 or less. When you try, relatively thermal conductivity,
And, the crack stress is high and the specific gravity is 1 or less,
The D group and the B and D groups are mixed. Next, crack stress was tested in the shape of the tube holder as shown in FIG. Table 4 shows the results. The most stress is applied to the semi-cylindrical recess, which often cracks. In the case of group D, reinforcement was made with a wire mesh having a mesh larger than the particle size (see FIG. 9).

[0018]

[Table 4] As for the product shape, the product of Group B and Group D was mixed (weight ratio 1: 1) and molded, and the crack stress was 3.53 kgf / cm2. (See FIG. 10) had a crack stress of 3.5
9, which was higher than that of each of the groups A, B, C, and D alone, which was 0.30 to 2.28 kgf / cm2. As a result of these experiments, it is easy to handle in the product shape, and the strength is appropriate, because the product of the B group and the product of the D group are mixed at a weight ratio of 1: 1.
Group D alone is reinforced with wire mesh. In addition, one of the tube holders for the cable protection tube with an outer diameter of 147 mm
An example is 182 mm in width, 91 mm in height, 500 mm in length, and the volume is about 4038 cubic cm, about 3.4 kg. By the way, if it is made of conventional concrete, it will be about 10 kg.

[0019]

According to the present invention, an inexpensive material can be used, the weight of the tube holder can be reduced, the handling can be facilitated, and the working efficiency can be improved while maintaining appropriate thermal conductivity. At the same time, the flexibility of positional accuracy and the ease of burying and replacing the cable protection tube required for the promotion of underground cable could be obtained at the pipe connecting portion of the cable protection tube.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a tube holder holding a cable protection tube.

FIG. 2 shows the upper tube holder and the lower tube holder in a perspective view.

FIG. 3 shows a connection part in a sectional view.

FIG. 4 is a perspective view showing an upper parallel pipe holder and a lower parallel pipe holder.

FIG. 5 shows a process of forming the tube holder.

FIG. 6 shows a compression test method in which a sample is formed in a rectangular parallelepiped shape.

FIG. 7 shows a compression test method performed on the product shape of the tube holder.

FIG. 8 shows a state in which a flexible rubber magnet sheet and a flexible rubber sheet containing iron powder are fixed to a connection portion between the upper tube holder and the lower tube holder.

FIG. 9 shows a tube holder incorporating a mesh.

FIG. 10 is a front view of a connection portion in the middle of an operation for burying a power protection or communication cable protection tube in an underground or the like.

FIG. 11 is a sectional view of the connection portion.

FIG. 12 is a front view of a connection part in the middle of an operation for burying a power protection or communication cable protection tube in an underground or the like in another embodiment.

FIG. 13 is a sectional view of the connection portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pipe holder 1-1 Upper pipe holder 1-2 Lower pipe holder 1-3 Upper recess 1-4 Lower recess 2 Cable protection pipe 2-1 Adjustment interval 3 Pipe connection part 4 Rubber ring 5 Parallel pipe holding Body 5-1 Upper parallel pipe holder 5-2 Lower parallel pipe holder 6 Wire mesh or net 7 Compressing plate 7-1 Upper compressing plate 7-2 Lower compressing plate 8 Rectangular parallelepiped sample 9 Flexible rubber magnet sheet REFERENCE SIGNS LIST 10 Flexible rubber sheet containing iron powder 11 Pile 12 Holding plate 13 Sheet material 14 Fluid filler such as sand 15 Ground 16 Groove wall 17 Strips such as band and wire 18 Connecting member or connecting portion 19 Holding member 20 Strips such as straps and wires 21 Connecting tools or connecting parts

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 24:26)

Claims (8)

[Claims] 1. A lightweight inorganic aggregate 100 having a particle size of 0.4 to 6 mm.
Per part by weight, 30 to 50 parts by weight of inorganic cement, 0.5 to 5 parts by weight of solid content of synthetic resin emulsion, and
Water is added in a weight ratio of water / inorganic cement of 0.55 to 0.7.
5, one or a plurality of parallelly arranged cable protection tubes, which are mixed and molded so as to be preferably 0.6 to 0.7, are arranged from above and below, and have a semicircular cross section on the upper surface and / or lower surface. A generally rectangular parallelepiped cable protection tube holder having a concave groove. 2. A cable protection tube having a tube end at one end and a cable protection tube having an opening at the other end, wherein one or more portions are serially divided and arranged at a portion other than the socket and the outlet. Item 2. A tube holder according to Item 1. 3. The tube holder according to claim 1, wherein the lightweight inorganic aggregate is pumice or foam glass beads. 4. The tube holder according to claim 1, wherein the synthetic resin emulsion is an emulsion of an acrylic resin, a vinyl acetate resin, a urethane resin or a styrene butadiene copolymer. . 5. A lightweight inorganic aggregate 100 having a particle size of 0.4 to 6 mm.
The solid content of the synthetic resin emulsion is 0.5
５5 parts by weight and water are mixed and stirred such that the weight ratio of water / inorganic cement is 0.55-0.75, preferably 0.6-0.7, and the aggregate is in a wet state. And then
Add 30-50 parts by weight of inorganic cement and further stir,
A method for producing a cable protection tube holder which is filled in a mold, molded, cured, and then released. 6. The method according to claim 5, wherein the lightweight inorganic aggregate is pumice or foam glass beads. 7. The method for producing a tube holder according to claim 5, wherein the synthetic resin emulsion is an emulsion of an acrylic resin, a vinyl acetate resin, a urethane resin, or a styrene-butadiene copolymer. 8. A pipe connecting portion is formed at intervals between the end faces of the cable protection tube holder, and the connecting portion is covered with a sheet material holding a fluid filler such as sand, and the connecting portion is filled with the filler. Structure of cable protection tube connection part filled with material.