JPH0993777A - Underground multi-purpose wire duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underground multi-purpose wire duct wherein any cast-in-situ concrete is not required to make the workers therefor unnecessary, and wires can be underlaid immediately after its execution to make the reductions of the period and cost of its construction possible, and further, the wires to be passed through the duct are not damaged. SOLUTION: An underground multi-purpose wire duct comprising a precast concrete block 1 with a predetermined length in whose square section an adequate number of pipes 2 are embedded, wherein annular sealing grooves 3 for storing packings therein are so formed in end surfaces 1a of both the end portions present in the longitudinal direction of the block 1 that the end surfaces of the pipes 2 are covered with concretes in the end surfaces 1a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric wire common groove as a facility for burying electric power lines, telephone cables and other electric wires underground in urban areas.

[0002]

2. Description of the Related Art An environment beautification movement is prospering in which electric wires in a city area, telephone cables and other electric wires are buried underground to improve the appearance of the city area and prevent traffic and other obstacles.

By the way, conventionally, in the work of burying an electric wire underground, an underground trench is excavated, an appropriate number of metal pipes are inserted into the underground trench, and these are hardened with concrete by on-site casting. Inserting wires is being done.

[0004]

However, according to the conventional construction, the concrete construction by pouring on-site is a metal pipe for inserting the formwork, various equipment and electric wires required for concrete pouring on the spot. In addition to transporting concrete, the construction work will be large-scale due to the need for concrete pouring personnel, etc., and it may be necessary to carry fresh concrete with a mixer truck, and further, curing after pouring concrete is required. , The construction period was long, and there were problems such as inconvenience of transportation.

Further, since the metal pipe is designed to obtain a required length by adding a fixed length of pipe, the end face of the pipe body is not completely matched at the joint, and the edge is exposed, whereby the electric wire is formed. Therefore, it is necessary to attach a collar or the like to the joint portion of the pipe body because of a problem such as damage to the pipe, which causes inconvenience such as cost increase caused by the necessity of the collar.

Accordingly, the present invention has been made in view of the above circumstances,
There is no need to cast concrete on-site, no personnel are required, electric wires can be laid immediately after construction, the construction period can be shortened and costs can be reduced, and electric wire joint grooves that do not damage the inserted electric wires I will provide a.

[0007]

The electric wire common groove according to the present invention comprises a precast concrete block having a predetermined length in which an appropriate number of pipes are embedded in a rectangular cross section, and both ends in the longitudinal direction of the precast concrete block. A seal groove for accommodating the packing is formed in a ring shape on the surface so as to surround the pipe body, and the end face of the pipe body is covered with concrete.

The portion covering the end face of the pipe body is formed of a taper surface of concrete cloth inclined toward the inner peripheral surface of the end portion of the pipe body which is recessed and retracted from the end face of the precast concrete block, and The precast concrete block is characterized in that connecting holes open at both ends thereof are formed so as to penetrate in the longitudinal direction.

With the above construction, a plurality of precast concrete blocks are arranged in a line in the underground groove in the longitudinal direction so as to have a required length, and the end faces are abutted with each other with a packing interposed in the opposing sealing grooves, and The electric wire joint groove is completed by inserting the connecting tools into the connecting holes and tightening them to connect them appropriately. Therefore, it can be laid in the ground by inserting the electric wire into the pipe. Since the end surface of the tube is covered with concrete, the wire is prevented from being caught by the edge of the end surface of the tube when the wire is inserted.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 3 to 6, an electric wire is provided in a cross section of a precast concrete 1 having a square cross section and a predetermined length. An appropriate number of pipes 2 to be inserted are buried, and a seal groove 3 for accommodating a packing made of an annular band of rubber or synthetic resin is formed annularly on the end faces 1a at both ends in the longitudinal direction. In addition, a pair of connecting holes 4 and 4 penetrate in the longitudinal direction in the substantially central portion of the end face 1a, and guide holes 5 and 5 having a predetermined depth are formed on one side.

The connecting hole 4 is expanded to a predetermined length on the side of the end face 1a, and when a plurality of precast concrete blocks 1 are continuously installed by abutting the end faces 1a in the longitudinal direction, a joint or the like of a connecting tool to be inserted therethrough. Can be fitted. When a plurality of the precast concrete blocks 1 are continuously provided by abutting the end faces 1a in the longitudinal direction, the guide hole 5 is inserted into one guide hole 5 with an appropriate steel rod or the like, and the steel rod or the like is inserted into the guide hole 5. It is formed so that the precast concrete blocks can be positioned so as not to shift from each other by fitting the precast concrete blocks into the guide holes 5.

The precast concrete block 1 is
A groove-shaped mold whose upper portion and both ends are opened in advance is prepared, and an appropriate number of pipes 2 are arranged in appropriate rows in the longitudinal direction in the vertical direction in the mold, and the ends of the pipes 2 are arranged. In order to form the connecting hole 4, two rods, etc. are arranged in a diagonal direction in a substantially central portion while being surrounded and fixed by the reinforcing bars 6 and 6, and for forming end portions at both ends of the formwork. After arranging the formwork, it is formed by pouring fresh concrete into the formwork.
The tube body 2 is made of a metal tube such as a steel tube or a non-metal tube such as a synthetic resin. The rod or the like having the connecting hole 4 formed therein is extracted after molding.

The end forming mold has a projection for forming a seal groove 3 at the end of the precast concrete block 1 and is hung inward from the end face 1a to the end face 2a of each pipe body 2. It has a conical protrusion that can form a tapered surface 7. The ends of the protrusions are inserted into the tubular body 2. Therefore, as shown in FIG.
The end surface 2a is covered with concrete cloth so that the edge of the end surface 2a of the tubular body 2 is not exposed.

As the connecting tool to be inserted into the connecting hole 4, for example, a tie rod having threaded portions at both ends is used. The tie rods have a predetermined length, and can be connected to each other via collars as joints at both ends to obtain a required length. The precast concrete block 1 that has been inserted is tightened by attaching washers or the like to both ends of the tie rod having the required length and fastening with a nut. Instead of the tie rod, a PC steel wire may be inserted into the connecting hole 4 to tighten each block.

As shown in FIG. 1, the tubular bodies 2 are arranged such that nine tubular bodies 2 are vertically and horizontally arranged in three steps at equal intervals in the cross section of a precast concrete block 1 having a square cross section. Alternatively, as shown in FIG. 2, the six pipe bodies 2 may be arranged in two stages in the vertical direction within the cross section of the precast concrete block 1a having a rectangular cross section. Precast concrete block 1a
Is free to place the long side on the bottom of the trench or the short side on the bottom of the trench.

Furthermore, an insert 8 for screwing an eyebolt for hanging is embedded and formed on one side surface of the precast concrete blocks 1, 1a, so that an appropriate hanging member such as an eyebolt is connected to this. Then
When transporting the precast concrete blocks 1 and 1a, make it easy to hang them with a crane.

Therefore, a plurality of the precast concrete blocks 1 or 1a are laid side by side in the longitudinal direction at the bottom of the underground groove, and the end faces are abutted while the packing is fitted in the seal groove 3, and the end faces are brought into the connecting hole 4. By inserting a connecting tool such as a tie rod and tightening the blocks together, a wire common groove having a required length can be obtained. Therefore, the electric wires can be inserted and housed in the tube bodies 2 communicating with each other.

[0018]

According to the present invention described above, since the precast concrete block has the pipe body through which the electric wire is inserted, it is not necessary to place the concrete on site, no personnel are required, and the electric wire is laid immediately after the construction. In addition, the construction period can be shortened, the cost can be reduced, and since the end surface of the pipe body is covered, the electric wire which should be inserted through the pipe body is not damaged by the edge.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a front view showing another embodiment.

FIG. 3 is a side view of FIG. 1;

4 is a sectional view taken along the line aa of FIG.

5 is a sectional view taken along line bb of FIG.

6 is a sectional view taken along line c-c of FIG.

FIG. 7 is an enlarged view of part A of FIG.

[Explanation of symbols]

 1, 1a ... Precast concrete block 1a, 2a ... End surface 2 ... Tubular body 3 ... Seal groove 4 ... Connection hole 5 ... Guide hole 6 ... Bar arrangement 7 ... Tapered surface 8 ... Insert

Claims (3)

[Claims] 1. A precast concrete block having a predetermined length in which an appropriate number of pipes are embedded in a rectangular cross section, and seal pipes for accommodating packings are provided on both end faces in the longitudinal direction of the precast concrete block. An electric wire common groove, characterized in that it is formed in an annular shape so as to surround the tube and the end surface of the tubular body is covered with concrete. 2. A portion for covering the end face of the pipe body is formed by a taper surface of concrete material inclined toward the inner peripheral surface of the end portion of the pipe body which is recessed and embedded from the end face of the precast concrete block. Claim 1
The electric wire joint groove described. 3. The electric wire common groove according to claim 1, wherein the precast concrete block is provided with connecting holes open at both ends thereof so as to penetrate in the longitudinal direction.