JP2001327018A - Bellmouth for corrugated tube, and connecting structure to transverse wall thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bell mouth for a corrugated tube by which a cable can be pulled and inserted always quickly, and to provide a mounting structure to an end wall which can be attached to a manhole, a hand hole or the like stably. SOLUTION: An internal thread 2b, which uses resin concrete as a blank and into which the spiral thread 4a of the corrugated tube 4 is inserted to be screwed, is provided. A guide 2c, which continues to the internal thread 2b and whose inside diameter is smaller than the inside diameter of the corrugated tube 4, is provided. The bellmouth 1, where profiling faces 2c-1, 2c-2 whose cross section is annular to be expanded gradually are formed on both ends in the axial line direction of the guide part 2c, is taper-fitted to a mounting hole 3a in the resin concrete ed wall 3, to be bonded and fixed by an adhesive 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bell mouth attached to an end of a corrugated pipe for burying a power cable, a communication cable and the like underground, and a structure for attaching the bell mouth to a wall.

[0002]

2. Description of the Related Art Corrugated pipes for passing these cables are used for underground construction of power cables and communication cables and construction of construction facilities. A bell mouth is attached to the end of the corrugated pipe to guide the cable into and out of the corrugated pipe and to protect the surface of the cable.

A bell mouth for such a corrugated tube is disclosed in, for example, Japanese Patent No. 2802931. The bell mouth described in this publication has a configuration in which an end of a corrugated pipe is inserted into an opening formed in a side wall of a manhole, and the bell mouth is inserted into the corrugated pipe. The bell mouth forms a spiral part to be screwed into the spiral of the corrugated tube at a part of the tip, and inserts and rotates the bell mouth into the corrugated tube from the inside of the manhole and rotates the spiral of the corrugated tube and the spiral of the bell mouth. The parts are fixed together by screwing. Mortar is filled around the corrugated pipe inserted into the opening,
A sealant is filled between the end of the corrugated tube and the end of the bell mouth.

In the case of a corrugated pipe having such a bell mouth, the bell mouth quickly guides the cable when the cable is inserted into or pulled out of the corrugated pipe, thereby improving workability and protecting the surface of the cable. Can be

[0005]

However, since the bell mouth is inserted into the inside of the corrugated tube, its tip in the insertion direction protrudes from the inner periphery of the corrugated tube (see FIG. 1 of the publication). For this reason, there is no problem when inserting the cable from the bell mouth, but when trying to pull out the cable passed through the corrugated pipe from the bell mouth with the pilot wire, the end of the bell mouth protruding from the inner periphery of the corrugated pipe Easy to poke. Therefore, the cable may not be quickly pulled out, and the cable may be damaged by abutting against the end of the bell mouth.

[0006] The tip of the corrugated pipe inserted into the opening formed in the side wall of the manhole is fixed by mortar. In this case, if the side wall is made of concrete, the joint strength with the mortar can be sufficiently obtained. However,
Since the corrugated pipe is made of resin, the bonding strength with the mortar mainly composed of cement is not so high. For this reason, if there is a change in the position of the manhole after the construction, an earthquake, or the like, there is a problem that the corrugated pipe and the mortar are easily separated, and the corrugated pipe cannot be stably held. In addition, water may be leaked due to peeling of the mortar, and the inside of the manhole or the handhole is wetted.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bell mouth for a corrugated pipe in which a cable can always be quickly connected and disconnected, and a mounting structure to a wand wall capable of stably mounting to a manhole or a handhole.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a bell mouth which is attached to an end of a corrugated pipe and guides a cable. The bell mouth is made of resin concrete, and a spiral strip of the corrugated pipe is inserted and screwed. A female screw and a guide portion connected to the female screw and having an inner diameter smaller than the inner diameter of the corrugated tube, and forming a scanning surface that gradually expands as an arc-shaped cross section at both axial ends of the guide portion. Features.

In the bell mouth of the present invention, when the spiral thread of the corrugated pipe is inserted into the female screw while being screwed into the female thread, the end of the corrugated pipe abuts on the guide part having a reduced inner diameter,
The profiling surface having an arc-shaped cross section connected to the guide portion is a continuous surface with the corrugated pipe. For this reason, there is no projecting step between the corrugated pipe and the guide portion, and the cable can be moved quickly.

In the present invention, at least the surface of the guide portion may be formed with a gel coat layer having a low friction coefficient.

[0011] In this configuration, the surface of the guide portion is made smooth by the gel coat, so that the cable is slid and the cable can be easily inserted and removed.

Further, the structure for mounting the bell mouth for a corrugated pipe to the wife wall of the present invention is a structure for mounting the bell mouth for a corrugated pipe to the wife wall, wherein the wife wall is made of resin concrete and the bell mouth is made of resin. The bell mouth and the mounting hole are taperedly fitted and fixed with an adhesive.

In such a mounting structure, since the bell mouth and the mounting hole are tapered, the construction can be simplified, and the bell mouth made of the same resin concrete and the rear wall are fixed with an adhesive. A strong bell mouth can be attached by adjusting the adhesive force of the adhesive.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show details of a bell mouth according to an embodiment of the present invention. FIG. 1A is a longitudinal sectional view taken along a plane including an axis, and FIG. 1B is a left side view.

In the figure, a bell mouth 1 is made of resin concrete, and has a gel coat layer 1a formed on a part of its surface by gel coating at the time of mold production. The gel coat layer 1a is formed by gel coating a polyester resin or the like, and has a static friction coefficient μ = 0.8 of resin concrete.
5, a coefficient of static friction of μ = 0.50 or less can be obtained.

The bell mouth 1 has a tapered surface 2a on the outer peripheral surface, and a female screw 2b for screwing into a corrugated tube (described later) except for the right end inside, and a female screw 2b on the right end. Is formed with a guide portion 2c smaller than the inner diameter. The aforementioned gel coat layer 1a is formed only on the surface and the right end face of the guide portion 2c, and the arcuate scanning surface 2c- is formed on both ends in the axial direction of the guide portion 2c.
1, 2c-2 are formed.

FIGS. 2A and 2B show details of the end wall, wherein FIG. 2A is a front view and FIG. 2B is a cutaway side view.

The wife wall 3 is made of resin concrete as in the case of the bell mouth 1, and is formed in a panel shape.
It is buried underground as a sidewall of a manhole or handhole. When constructed as this side wall, the right side of the end wall 3 in FIG. 2B is a manhole or a handhole, and the left side is a surface facing the ground. A plurality of mounting holes 3a having different inner diameters are formed in the rear wall 3, and the mounting holes 3a to which the corrugated pipe is not connected are sealed with, for example, a synthetic resin cap (not shown). The mounting hole 3a is
In FIG. 2B, the tapered hole has a large diameter on the right side, that is, the manhole or handhole side, and has a smaller diameter toward the left side.

FIG. 3 is a schematic view showing the steps from connection of the corrugated tube to the bell mouth 1 and fixing of the bell mouth 1 to the end wall 3.

In FIG. 3, the corrugated pipe 4 is made of synthetic resin and has a single spiral strip 4a. The female screw 2b of the bell mouth 1 is formed in accordance with the size and pitch of the peaks and valleys of the spiral strip 4a. Less than,
The steps will be described in order.

First, as shown in FIG. 3A, a corrugated pipe 4 is piped so as to correspond to the mounting hole 3a of the end wall 3,
The corrugated pipe 4 is pulled out from the mounting hole 3a to the manhole or handhole side (FIG. 2B). Next, the bell mouth 1 is screwed into the corrugated pipe 4 while holding the bell mouth 1 by hand so that the female screw 2b of the bell mouth 1 is screwed into the spiral ridge 4a on the drawing end side of the corrugated pipe 4 (FIG. )). Then, the adhesive 5 is applied to a portion corresponding to the inner peripheral wall of the mounting hole 3a on the tapered surface 2a of the bell mouth 1 (FIG. 4D). It is preferable to use, for example, a polyester-based or epoxy-based adhesive as the adhesive 5 so that the bell mouth 1 and the end wall 3 made of resin concrete can be firmly joined. After the adhesive 5 is applied, the bell mouth 1 is inserted into the mounting hole 3 as shown in FIG.
a, and the bell mouth 1 is fixed to the end wall 3 by taper fitting and joining by the adhesive 5.

FIG. 4 is a longitudinal sectional view of a main part when the bell mouth 1 to which the corrugated pipe 4 is connected is fixed to the rear wall 3, and FIG. 5 is a right side view of FIG.

As shown in FIG. 4, the spiral ridge 4a of the corrugated tube 4 is screwed and connected to the female screw 2b of the bell mouth 1, and the tip of the corrugated tube 4 is inserted until it comes into contact with the end face of the guide portion 2c. ing. The inner diameter of the guide portion 2c is smaller than the inner diameter of the female screw 2b, and is smaller than the inner diameter of the corrugated tube 4 as shown in the figure. For this reason, the end of the corrugated pipe 4 is connected so as to be included in the profiling surface 2c-2 of the guide portion 2c, and the end of the corrugated pipe 4 is gently connected to the profiling surface 2c-2 without unevenness. .

In the above configuration, the end of the corrugate 4 is screwed into the bell mouth 1 and this end is fitted to the copying surface 2c.
-2 so that it is connected so as to be loosely connected, so when inserting or pulling out a cable (not shown),
The cable moves quickly and does not damage the surface. Further, since the gel coat layer 1a having a small static friction coefficient is formed on the surface of the guide portion 2c, the frictional resistance at the time of pulling out and inserting the cable is small, and the cable can be moved quickly. That is, since the profiling surfaces 2c-1 and 2c-2 are formed in the guide portion 2c, the cable moves lightly along these profiling surfaces 2c-1 and 2c-2, and the cable moves between the corrugated tube 4 and the corrugated tube 4. Since there are no projecting steps, the cable does not stick. Therefore, in the operation of pulling out or inserting the cable by the pilot wire, there is nothing that causes the cable to interfere with the external force between the bell mouth 1 and the corrugated pipe 4, and the wiring can be performed without damaging the cable.

On the other hand, since the bell mouth 1 is tapered into the mounting hole 3a, the bell mouth 1
Is firmly fixed. And bellmouth 1 and wife wall 3
Are made of the same resin concrete, and by using an adhesive 5 suitable for joining the resin concrete,
The bell mouth 1 can be more firmly fixed. Therefore, even if the rear wall 3 moves up, down, left, and right, the bell mouth 1 does not fall out of the mounting hole 3a, and the bell mouth 1 is stably held even in the event of an earthquake.

[0027]

According to the bell mouth for a corrugated pipe of the present invention, the corrugated pipe is inserted and screwed into the bell mouth so as not to form a projecting step.
Since the cable is guided by the guide section including the profiling surface connected to the corrugated pipe, the cable can be quickly inserted and removed, and the surface is prevented from being damaged. When a gel coat layer is formed on the guide portion, the frictional force is reduced, so that the cable can be handled more quickly.

Further, in the mounting structure of the bell mouth for a corrugated pipe of the present invention to the wife wall, the bell mouth is fixed to the mounting hole by taper fitting, so that the mounting becomes simple, and the same bell mouth and wife made of the same resin concrete are used. Since the wall and the wall are bonded with an adhesive, the adhesive strength can be maintained high, and stable mounting can be achieved.

[Brief description of the drawings]

FIG. 1 is a detail of a bell mouth according to an embodiment of the present invention, in which (a) is a longitudinal sectional view cut along a plane including an axis;
FIG. 2B is a left side view of FIG.

FIG. 2 shows details of the wall, (a) is a front view,
(B) is a cutaway side view.

FIG. 3 is a schematic view showing a process of connecting a bell mouth to a corrugated tube and fixing the bell mouth to a mounting hole.

FIG. 4 is a longitudinal sectional view when a bell mouth to which a corrugated tube is connected is fitted and fixed in a mounting hole of a wife wall.

FIG. 5 is a right side view of FIG.

[Explanation of symbols]

 Reference Signs List 1 bell mouth 1a gel coat layer 2a taper surface 2b female screw 2c guide portion 2c-1,2c-2 profiling surface 3 end wall 3a mounting hole 4 corrugated tube 4a spiral strip 5 adhesive

Claims (3)

[Claims] 1. A bell mouth which is attached to an end of a corrugated pipe and guides a cable, comprising: a female screw into which a spiral strip of the corrugated pipe is inserted and screwed using resin concrete as a material; A bell mouth for a corrugated tube, comprising: a guide portion having an inner diameter smaller than the inner diameter of the corrugated tube, and forming a gradually expanding scanning surface as an arc-shaped cross section at both ends in the axial direction of the guide portion. 2. The bell mouth for a corrugated pipe according to claim 1, wherein a gel coat layer having a low coefficient of friction is formed on at least a surface of said guide portion. 3. A structure for attaching the bell mouth for a corrugated pipe according to claim 1 or 2 to a rear wall, wherein the rear wall is made of resin concrete and a mounting hole for inserting and fixing the bell mouth is opened. The bellmouth and the mounting hole are taperedly fitted and fixed with an adhesive, and the bellmouth for a corrugated pipe is attached to the end wall.