JPH09292056A - Connection structure for underground cable laying common ditch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure which takes a few man-hours of work and keeps cut-off performance for a long time. SOLUTION: In a connection structure for a common bitch 1, a bolt through- hole 2 is formed on a center portion, while a plurality of cable through-holes 4 are formed around it. The groove 1 has one end provided with a cylindrical collar 6 and the other end provided with a male portion 1B fitted to a fitting portion 6B of the cylindrical collar 6. The fitting portion is connected to the male portion by means of paired packings 8, 20 which are separately arranged on a longitudinal direction. The common ditches are unitedly connected to each other by fastening a connection rod 10 which is inserted into the bolt through-hole 2 and connectable through screwing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure of a common groove used when installing cables for power, communication, etc. underground.

[0002]

2. Description of the Related Art In recent years, in order to improve the scenery of cities and urban areas, a means for laying cables for electric power and communication underground has been adopted. A box-shaped concrete product, a flexible pipe made of resin, or a perforated pipe made of concrete or porcelain is used as a member for constructing the pipeline for accommodating the cable. In this case, since the weight of the vehicle extends to the pipeline, product performance such as strength, flatness of the pipeline (the strain is unlikely to occur in the pipeline), and durability are important.

As described above, in the case of a pipe line installed in a place where a vertical load is applied by a vehicle or the like, even if the pipe is made of resin having a relatively small structural strength, concrete is placed after the installation to improve the strength. Although there is a means for achieving it, it is preferable to use a perforated pipe made of concrete or ceramics in view of the ease of construction and construction cost.

In the case of a concrete perforated pipe, first, a product or a construction method in which a socket-shaped connection structure and packing which maintain watertightness are sufficiently applied in order to protect the cable from dirty water and the like. However, for pipelines installed further underground, durability against vibration due to earthquake and impact due to unequal settling, and especially when constructing pipelines in the roadway, In order to achieve this, it is necessary to pursue its workability.

In view of the both durability and workability against excessive load or long-term load, a prefabricated pipe with a connecting rod is disclosed, for example, as in the invention disclosed in Japanese Patent Publication No. 60-10235. There is a connection method.

[0006]

However, the aforementioned Japanese Patent Publication No. Sho 6
In the case of firmly connecting the common grooves by the means disclosed in Japanese Patent Application Laid-Open No. 0-10235, when the common grooves are connected to each other, a screw rod required for pushing and fitting and a connecting bolt for maintaining a fastening state. There is room for improvement in the workability because it requires two steps, and there is a labor during the work of replacing with the insertion hole after the connection.

Further, in the common groove having the conventional socket structure, the watertightness of the connecting portion is ensured by the fitting structure of the male portion and the female portion and the installation of the rubber packing closely attached to the joint peripheral surface. However, the joint surfaces are not directly and mutually adhered, and if the connector is loosened or loosened due to vibration, load, etc., the adhesion of the packing will be lost, from which groundwater or There is also a possibility that foreign matter may enter and damage the cable installed in the pipeline.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is capable of reducing the number of construction steps and maintaining the waterproof property of the connecting portion for a long period of time. The purpose is to provide what can be done, and the gist of the invention is to install a bolt insertion hole in the center and a plurality of cable insertion holes in the periphery of the bolt insertion hole. A common groove having a male collar fitted in the fitting portion of the tubular collar at the other end, and the male portion fitted in the fitting portion and the inside thereof are separated from each other in the front and rear direction. When connecting through a pair of packings arranged as described above, the joint groove is integrally connected by fastening a connecting rod which is inserted into the bolt insertion hole and can be connected by screw connection. It is in the joint structure of the joint ditch for underground cable installation.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. In FIGS. 1 and 2, A is a common ditch for installing underground cables, and this common ditch A is
It is constructed by connecting box-shaped joint grooves 1, 1-1 formed of concrete as shown in FIGS. 3 and 4. That is, the common groove 1 has a solid rectangular parallelepiped shape, and a bolt insertion hole 2 penetrates through the center of the common groove 1 in the longitudinal direction.
Has a funnel-like hole shape in which a large-diameter opening and a small-diameter opening having substantially the same cross section as the outer shape of the enlarged head of the connecting rod, which will be described later, are connected on the inclined peripheral surface 3A.

Reference numeral 4 denotes a plurality of cable insertion holes formed around the bolt insertion hole 2 and having different diameters. Each cable insertion hole 4 extends in parallel with the bolt insertion hole 2 and penetrates the common groove 1. A pipe 5 made of vinyl chloride is installed in each cable insertion hole 4. This is because when a heavy cable is inserted into the cable insertion hole 4, the frictional resistance with the inner peripheral surface of the cable insertion hole 4 is reduced to facilitate the insertion.

Reference numeral 6 denotes a rectangular tubular collar made of metal, and one end portion 6A thereof is fitted to the outer periphery of one end portion of the common groove 1 through an embedded packing 7 as shown in FIGS. The other end extends outwardly from one end surface 1A of the common groove 1 to form a fitting portion 6B, and a male portion 1B formed at the other end of the common groove 1 in the fitting portion 6B. Are formed so as to be fitted therein.

Reference numeral 8 denotes a fixed packing having a substantially triangular cross section, and the fitting portion 6 of the cylindrical collar 6 is provided on the outer peripheral surface thereof.
It is fixed to the inner circumference of the base portion of B, and the inclined surface portion 8A of the fixed packing 8 faces in the direction facing the opening portion of the fitting portion 6B.
That is, from the inner peripheral surface of the tubular collar 6 to the one end surface 1 of the common groove 1.
It is installed in a state of gradually descending toward A. In the figure, 9A is a pipe for injecting a sealing material which is attached to the lower portion of the cylindrical collar 6 in a penetrating state, and 9B is an air bleeding pipe attached to the upper portion.

Reference numeral 10 denotes a connecting rod which is inserted into the bolt insertion hole 2. As shown in FIG. 5, a male screw 11 is formed on the outer periphery of the tip end thereof, and the other end is continuous with a tapered peripheral surface 12A. A dish-shaped enlarged head 12 is provided, and the enlarged head 1 is provided.
A female screw 13 that is screwed with the male screw 11 is formed on the inner periphery of a central hole 12C that extends in the axial direction following a large-diameter hole 12B formed at the center of 2. Reference numeral 14 in the drawing denotes a recess formed on the end surface of the enlarged head 12 for engagement with a rotary tool described later.

Reference numeral 15 is a rotary tool for rotating the connecting rod 10, and as shown in FIG.
6, a rotation shaft 17 fixed to the center of one end surface of the rotation support portion 16, a grip portion 18 fixed to one end of the rotation shaft 17 in a T-shape, and the above-mentioned protruding portion from the other end surface of the rotation support portion 16. Each of the engaging projections 19 is configured to engage with the locking recess 14.

Next, the method of connecting the common grooves 1 in series to form the common groove path A will be described in detail. As shown in FIG. 7, first, the common grooves 1-1 to be connected are already laid. When the male portion 1B of the joint groove 1-1 is made to face the fitting portion 6B of the tubular collar 6 of the joint groove 1 which has been completed, in close proximity, the joint groove 1-in the fitting portion 6B. The male part 1B of 1 is loosely fitted. At this time, the packing 20 is fitted in advance on the outer circumference of the base of the male portion 1B of the common groove 1-1.

Then, the connecting rod 10 is inserted into the bolt insertion hole 2 of the common groove 1-1 to be connected from the opening 3 from its tip, and the male screw 11 formed at the tip of the connecting rod 10 is inserted. It is put in the central hole 12C following the large diameter hole 12B of the enlarged head 12 of the connecting rod 10 which is fastened in the bolt insertion hole 2 of the existing joint groove 1. And the inserted connecting rod 1
0 around the enlarged head 12 to move the central hole 1
The male screw 11 of the inserted connecting rod 10 is screwed into the female screw 13 formed in 2C.

In this state, as shown in FIG. 6, each engaging projection 19 provided on the other end surface of the rotary support 16 of the rotary tool 15 and the end surface of the enlarged head 12 of the inserted connecting rod 10. And the convex portions 19 for engagement are engaged with the concave portions 14 for engagement. Then, when the rotating shaft 17 is rotated by the gripping portion 18 while supporting the rotary supporting portion 16 with one hand, the connecting rod 10 is screwed in the direction of the existing common groove 1 by the engagement of the male screw 11 and the female screw 13, The tapered peripheral surface 12A of the enlarged head 12 collides with the inclined peripheral surface 3A in the opening 3 of the common groove 1-1.

Further, the rotary shaft 1 is further provided via the grip portion 18.
When 7 is rotated and the connecting rod 10 is screwed into the bolt insertion hole 2, the taper peripheral surface 12A of the enlarged head 12 moves the inclined peripheral surface 3A in the opening 3 of the common groove 1-1 to the common groove 1 of the common groove 1. Press in the direction. In this case, since the enlarged head 12 and the opening 3 of the joint groove 1-1 are in contact with each other at the tapered peripheral surface 12A and the inclined peripheral surface 3A, the joint groove of the connecting rod 10 due to the rotation of the enlarged head 12 is in contact. The pressing force in the direction 1 is easily transmitted to the common groove 1-1, and the male portion 1B of the common groove 1-1 moves in the arrow direction in FIG.

Thus, as shown in FIG. 7, the common groove 1-1
The end portion of the male portion 1B of the fixed portion 8 abuts on the inclined surface portion 8A of the fixed packing 8.
The male portion 1B is fitted into the fitting portion 6B in a state where A is pressed toward the inner peripheral surface of the tubular collar 6 and the fixed packing 8 is crushed. At the same time, the tip of the fitting portion 6B flattens the packing 20 fitted on the outer circumference of the base of the male portion 1B, and the common groove 1-1 and the existing common groove 1 are fixed packing 8 as shown in FIG. And when they are connected in a sealed state via the packing 20,
As shown in FIG. 11, the existing common groove 1 and the common groove 1-1 are integrally connected by a connecting rod 10.

As described above, the joint groove 1-1 and the existing joint groove 1 are water-tightly and rigidly connected to each other in an integrated structure. However, in the present invention, the water-tight structure is further improved by the following constitution. Can be improved. That is, as shown in FIG. 9, the space portion 2 surrounded by the outer periphery of the fixed packing 8, the packing 20, and the male portion 1B in the fitting portion 6B.
The seal material 21 is injected into the inside of the pipe 2 from the seal injection pipe 9A attached to the lower portion of the tubular collar 6, and the injection operation is continued until the seal material 21 overflows from the air bleed pipe 9B attached to the upper portion. The space 22 is filled with the seal material 21.

When the sealing material 21 is hardened, as shown in FIG. 10, the joint groove 1-1 to be connected to the joint groove 1 is the fitting portion 6B of the tubular collar 6.
In, fixed packing 8, packing 20, sealing material 2
1 provides a connection structure that is more densely bonded to a wider area and has watertightness and durability against vibration and load. Here, it is desirable that the seal material 21 has physical properties (fluidity during construction, strength after curing, adhesive strength) similar to mortar, grout material, etc. having high fluidity.

In the same manner, the next joint groove 1-2 is connected to the joint groove 1-1, and by repeating this operation, as shown in FIGS. 1, 2 and 12, a desired length is obtained. Since the common groove A is formed, the cables for electric power, communication, etc. are installed underground by inserting the cables into the respective cable insertion holes 4 of the common groove A communicating with each other.

In FIGS. 1 and 2, reference numeral 23 in the drawings denotes a single pipe portion, which is constituted by a flexible pipe 24, and individually draws out a plurality of cables K from the cable insertion hole 4 of the common groove 1. It is the part that Then, as shown in FIG. 13, the connecting means between the single pipe portion 23 and the common groove 1 is, as shown in FIG. 13, the projecting portion 5A of the synthetic resin pipe 5 installed in each cable insertion hole 4 and one end of the flexible pipe 24. Are connected via both receiving sockets 25, and watertightness and durability can be ensured with a simple structure.

Further, in the figure, reference numeral 26 is a branch box, which is for branching the cables in the branch box 26, pulling out each branched cable from the branch box 26 and installing it at a required place. As shown in FIG. 14, the connecting means between the other end of the flexible pipe 24 and the branch box 26 of FIG. 23 forms a through hole 27 in a side wall 26A of the branch box 26, and a mortar or the like 28 is formed in the through hole 27. Bell-mouth-shaped opening 29 of connecting tube 29 fixed via
The other end of the flexible pipe 24 is connected to the inside of A by fitting, so that the construction efficiency and watertightness can be improved.

[0025]

As described above, the joint structure of the joint groove for installing an underground cable according to the present invention has a bolt insertion hole in the center and a plurality of cable insertion holes around the bolt insertion hole. A common groove having a cylindrical collar on the outer circumference of one end and a male portion that fits inside the fitting portion of the tubular collar on the other end, and is fitted into the fitting portion and the inside thereof. When the male part and the male part are connected via a pair of packings spaced apart from each other in the front and rear, both joint grooves are integrally connected by fastening a connecting rod which can be connected by a screw connection inserted in the bolt insertion hole. Because of the structure, a solid integration is achieved by fastening the connecting rods of the common grooves, and a watertight connection structure is formed by the pair of packings associated with the integration. Therefore, a common ditch can be constructed in a short time with a small number of construction steps, and it is particularly effective when laying in a place where traffic is required to be opened promptly, such as in a roadway. In addition, when the space between the pair of packings is filled with the sealing material, the sealing effect is further improved due to the adhesive effect of the sealing material. Even if the connecting part is loosened, distorted, or damaged due to a load, the waterproof property of the connecting part is not easily lost. Further, one end opening portion of the bolt insertion hole penetrating in the center is formed into a funnel-shaped hole shape, the connecting rod is provided with a male screw at the tip end, and the other end is provided with an enlarged head having substantially the same cross section as the one end opening portion. By having a structure in which a central hole extending from the enlarged head has a female screw that is screwed with the male screw, it is possible to smoothly perform the connecting work of the joint grooves by the connecting rod with a relatively small force. , The fixed packing has a substantially right-angled triangular cross section, and the inclined surface portion is installed so as to face the opening of the fitting portion. Water-tight joining can be performed at the same time, and there are various effects that the number of working steps can be reduced.

[Brief description of drawings]

FIG. 1 is a front view of a laid state of a common ditch applying a connection structure according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a front view in which a common groove is partially omitted.

FIG. 4 is a right side view of FIG.

FIG. 5 is a partially omitted perspective view of a connecting rod.

FIG. 6 is a perspective view of a rotary tool.

FIG. 7 is an enlarged cross-sectional first operation explanatory partial view of the connecting portion.

FIG. 8 is an enlarged cross-sectional second operation explanation partial view of the connecting portion.

FIG. 9 is a third operation explanatory view of the connecting portion.

FIG. 10 is a fourth operation explanatory view of the connecting portion.

FIG. 11 is an enlarged partial view taken along the line II-II of FIG.

12 is an enlarged partial view taken along line III-III of FIG.

FIG. 13 is an enlarged partial view taken along line IV-IV of FIG.

14 is an enlarged partial view taken along line VV of FIG.

[Explanation of symbols]

 A common groove 1 common groove 1A end face 1B male part 2 bolt insertion hole 3 opening 3A inclined peripheral surface 4 cable insertion hole 5 PVC pipe 6 tubular collar 6A one end 6B fitting part 7 embedded packing 8 fixed packing 8A sloped part 9A Injection pipe 9B Air bleeding pipe 10 Connecting rod 11 Male screw 12 Enlarged head 12A Tapered peripheral surface 12B Large diameter mouth 12C Center hole 13 Female screw 14 Recessed groove 15 Rotating tool 20 Packing 21 Sealing material 22 Space part 23 Single pipe part 24 Flexible tube 25 Both receiving socket 26 Branch box

Claims (5)

[Claims] 1. A bolt insertion hole is formed in the center and a plurality of cable insertion holes are formed around the bolt insertion hole, and a cylindrical collar is formed on the outer periphery of one end and the cylindrical collar is formed on the other end. A joint groove provided with a male part that fits inside the fitting part, wherein the fitting part and the male part fitted inside the fitting part are connected via a pair of packings that are spaced apart in the front-rear direction. (1) A joint structure for connecting a joint groove for installing an underground cable, characterized in that the joint groove is integrally connected by fastening a connecting rod which is inserted into the bolt insertion hole and is connectable by screw connection. 2. The joint structure for connecting a joint groove for installing underground cables according to claim 1, wherein the space between the pair of packings is filled with a sealing material. 3. A bolt insertion hole formed at the center has a funnel-shaped opening at one end, and a connecting rod has a male screw at the tip and an enlarged head having a cross-section substantially the same as the one-end opening at the other end. The connection structure for a joint groove for installing underground cables according to claim 1 or 2, wherein each of them has a structure in which a central hole extending from the enlarged head has a female screw to be screwed with the male screw. 4. The underground according to claim 1, wherein the pair of packings are a fixed packing fixed to the inner circumference of the base of the fitting portion and a packing fitted to the outer circumference of the base of the male portion. Joint structure for joint groove for cable installation. 5. The fixing packing has a substantially right-angled triangular cross section, and is installed so that its inclined surface portion faces the opening of the fitting portion. Connection structure of the joint groove for installation of the underground cable described.