JPH1118244A - Coupling for communication line protective pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the workability of pulling-in work, when a communication line protective pipe is pulled in a housing hole of an external pipe by reducing the moving resistance of the protective pipe when the protective pipe is pulled in the housing hole and, at the same time, to effectively utilize the limited space of the housing hole of the outer pipe. SOLUTION: A coupling 1A consists of a pair of inserting sections 10 and 11 respectively, having outer peripheral surface 100 and 110 which are inserted into holes 20 of a pair of communication line protective pipes 2 and 2 to be connected to each other and a central section 12a, which is successively provided from the inserting sections 10 and 11 in an integral state and has a largest outside diameter D2 which is nearly equal to the outside diameter D3 of the pipes 2 and 2 and a central section 12a, in which a ring-like strip is formed by protruding the outer peripheral surfaces 100 and 110 of the inserting section 10 and 11. The two communication line protective pipes 2, which are respectively connected to the both outer peripheral surfaces 100 and 110 separated from each other by the central section 12a, are inserted into the central part 12a and joined with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint for a communication line protection pipe.

[0002]

2. Description of the Related Art Conventionally, for example, a communication cable (a cable to be laid such as a metal cable, an optical fiber cable, an electric wire, a power line, and a spare line) is a large-diameter outer tube previously set at a predetermined position in the ground. [Steel pipes, concrete pipes, polyvinyl chloride (PVC) pipes, etc.] One to three pipes that are sorted into a large number of inner pipes (hereinafter referred to as communication line protection pipes) that are drawn and laid in the hole passages. Is inserted in units of

The communication line protection tube has a length of, for example, 4 mm.
Are successively connected along the axial direction by a cylindrical joint, and are used after being extended to a target length (for example, 50 m to 250 m). Here, for example, in the conventional cylindrical joint 1D shown in FIGS. 8 to 10, two communication line protection tubes 2, 2 are inserted into the holes 12d from both ends opening sides 10d, 11d, respectively. It is configured.

[0004]

The conventional tubular joint 1 described above.
In the case of D, since the inner diameter d5 of the hole 12d and the outer diameter D3 of the communication line protection tubes 2 and 2 are substantially the same, the outer diameter D5 is equal to the outer diameter of the communication line protection tubes 2 and 2. It is larger than the diameter D3 and about 3 to 6 mm longer when compared by radius. Therefore,
The outer peripheral surface 13d of the cylindrical joint 1D forms a large step e protruding from the outer peripheral surface 22 of the communication line protection pipe 2, 2 in the radially outward direction R1 at both ends in the longitudinal direction. For this reason, the following problems occur. That is, (1) at the time of additionally drawing the communication line protection pipes 2, 2 connected using the cylindrical joint 1 </ b> D into the housing hole 40 of the outer tube 4, the joint of the inner peripheral surface 41 of the housing hole 40, Another tubular joint 1 joined to another already-retracted communication line protection pipe 2
The workability is reduced, for example, the step e contacts or gets caught on the D to increase the movement resistance, or the drawing resistance needs to be drawn in with a large traction force as the movement resistance increases. (2) Since the step e of the tubular joint 1D occupies an extra space in the limited space of the inner diameter d4 of the housing hole 40 of the outer tube 4, waste is generated by this amount, and the communication line protection tube 2 is removed. The number that can be arranged in a state of being stacked in parallel is reduced (reduced), and the space cannot be used effectively.

Further, as the communication line protection tubes 2 drawn into the housing hole 40 of the outer tube 4 are stacked in parallel, the remaining space of the housing hole 40 becomes narrower and there is almost no room, so that the drawing workability is further improved. And work efficiency becomes worse. ADVANTAGE OF THE INVENTION This invention can reduce the moving resistance at the time of pulling in the communication line protection pipe | tube into the accommodation hole of an outer tube, can improve the workability | operativity, and can effectively utilize the limited space of the accommodation hole of an outer tube. An object of the present invention is to provide a joint for a communication line protection pipe.

[0006]

According to a first aspect of the present invention, a joint for a communication line protection pipe is a cylindrical joint for axially connecting communication line protection pipes accommodating communication lines (cables) in holes. hand,
The tubular joint is connected to the pair of insertion portions having an outer peripheral surface that is inserted into each hole of the pair of communication line protection tubes and abuts on the inner peripheral surface thereof. -A central portion which is physically connected, has a longest outer diameter substantially equal to the outer diameter of the communication line protection tube, and forms a ring-shaped ridge protruding from the outer peripheral surface of the insertion portion. The two communication line protection tubes to be connected to the outer peripheral surface on one side and the other outer peripheral surface partitioned on both sides by the central portion having the projection are inserted and joined. And

According to a second aspect of the present invention, in the joint for a communication line protection pipe according to the first aspect, the ridge has an inclined surface inclined toward at least one outer peripheral surface. According to a third aspect of the present invention, in the joint of the communication line protection pipe according to the first aspect, at least one side surface of the ridge is a flange-shaped surface with which the end face of the communication line protection pipe inserted into the fitting portion abuts. It has become.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A joint according to the present invention is provided between a pair of insertion portions for connecting a communication line protection tube in a longitudinal direction, and a pair of insertion portions. And a central portion that forms a ring-shaped protrusion that protrudes from the outer peripheral surface of the communication line protection tube.

For this reason, when the communication line protection tubes are respectively inserted into the pair of insertion portions formed on both sides of the central portion,
The outer peripheral surface of the communication line protection tube and the outer peripheral surface of the central portion are substantially flat. That is, according to the joint of the present invention, when drawn together with the communication line protection tube into the housing hole of the outer tube,
The space occupied in the radial direction can be reduced to almost the same space as the communication line protection tube, and by inserting the communication line protection tube into the joint hole as in the case of the conventional joint, the joint can be reduced. Can be prevented from projecting radially outward from the outer peripheral surface of the communication line protection tube to generate a large step.

Therefore, when the communication line protection pipe connected in the axial direction by using the joint of the present invention is drawn into the outer pipe, the outer peripheral surface of the joint may have a joint at the inner peripheral surface of the outer pipe or may have already been drawn. The pull-in operation can be performed promptly without being caught by another joint or the like joined to another already-used communication line protection tube. Furthermore, in the area where the joint is located, there is no need for extra occupied space, only a space corresponding to the outer diameter of the communication line protection tube is required, and only a limited number of housing holes for the outer tube are accommodated. We can utilize space effectively.

[0011] A resin molded product can be used for the tubular joint of the present invention. As the material of the tubular joint, a resin or the like having the same quality as that of the communication line protection tube can be used. Further, the material of the pair of insertion portions and the central portion can be changed.
In this case, for example, the same material as the communication line protection pipe made of hard polyvinyl chloride is used as the material of the insertion portion of the pair, and the material of the center portion is made of soft polyvinyl chloride. Can be.

The insertion portion and the central portion have different axial lengths and outer diameters. The difference between the outer peripheral surface diameter of the insertion portion and the longest outer diameter of the central portion is set to a value corresponding to the thickness of the communication line protection tube inserted into the insertion portion. Therefore, various settings can be made for each communication line protection tube having a different thickness. The longest outer diameter at the center of the tubular joint is substantially the same as the outer diameter of the communication line protection tube.

[0013] The range of the substantially the same is the case where the outer peripheral surface of the communication line protection pipe inserted through the insertion portion of the tubular joint and the outer peripheral surface of the central portion are the same, This includes a case where the outer peripheral surface of the central portion is set at a low position slightly (with a limit of 0 to 0.5 mm) with respect to the reference. For example, when the outer peripheral surface of the central portion is set to the low value, the outer peripheral surface is parallel to the axial direction (longitudinal direction), and the outer peripheral diameter of the outer peripheral surface of the communication line protection tube attached to the insertion portion is adjusted. Only slightly (0.
When the height is set to a low value (approximately 1 mm to 0.5 mm) and the height is set to a high position, an inclined surface having an inclined angle is provided on one side or both sides of the pair of insertion portions, and is slightly (0.1 mm to 0 mm). .5m
m).

When the outer peripheral surface of the central portion is formed by the inclined surface, when the communication line protection tube is pulled into the housing hole of the outer tube together with the joint, the communication line protection tube becomes lower toward the side opposite to the drawing direction. By using it at the inclined angle, even if it comes into contact with the joint on the inner peripheral surface of the accommodation hole or another joint joined to another communication line protection tube that has already been drawn in, it will not hinder the drawing in and will not contact. The effect of reducing the movement resistance by the sliding action at the time can be obtained.

[0015] Both side surfaces of the central portion forming the ring-shaped projection are opposed to the end surface of the communication line protection tube inserted through the pair of insertion portions, and are flange-shaped surfaces with which the end surfaces abut. Therefore, it functions as an insertion positioning stopper for the communication line protection tube. Further, as the outer pipe for drawing in and containing the communication line protection pipe connected by using the joint of the present invention, a steel pipe, a concrete pipe, a cylindrical and a substantially square tubular shape, or an upper opening can be detachably attached. A U-shaped or substantially U-shaped groove provided with a lid for mounting is used.

Further, when the communication line protection tube connected by using the joint of the present invention is drawn into the housing hole of the outer tube, a plurality of the communication line protection tubes are held at the same time while being held in a parallel state. A guide member (guide laying guide for pipe laying) having a spherical body that slides and slides on the inner bottom surface of the housing hole of the outer tube can also be used.

The joint of the communication line protection pipe of the present invention is used as follows. First, the joint is used during a preparation operation prior to the drawing operation into the outer tube. In other words, the number of communication line protection tubes to be drawn into the outer tube is prepared in advance, and the required number of communication line protection tubes in the longitudinal direction at both ends of the connection line protection tube are connected in the opposite directions. The paired insertion parts are joined and connected (integrated).

In order to join the connecting part of the joint of the joint to the communication line protecting tube, an adhesive is applied to the connecting part of the joint, and then the communication line protecting tube to be joined is applied. Insert into the hole.
Thus, the communication line protection tube before being drawn into the outer tube is
One opening is connected to the other end of the joint of the joint, and the other opening is left as it is (unconnected state), and a large number of openings are prepared.

First, the communication line protection pipes for the first pull-in are arranged singly or in parallel from the entrance into the housing hole of the outer pipe with the other opening without the joint at the head (front side). Are pulled in at the same time. At this time, the communication line protection tube is pulled in until the other insertion portion of the joint previously connected to the opening side projects from the inlet of the outer tube to the outside.

After applying an adhesive to the other insertion portion of the joint protruding to the outside of the outer tube, another communication line protection tube is joined through the other opening not having the joint. -Body and add. Thereafter, the extended communication line protection tube is drawn into the housing hole of the outer tube in the same manner as the communication line protection tube for the first retraction, and the other of the joints protruding to the outside of the outer tube. The step of adding another communication line protection tube to the insertion portion is repeated.

That is, the refilling operation and the drawing operation of the outer tube into the receiving hole are repeated, and the communication line protection tube, the joint, the communication line protection tube, the joint, the communication line protection tube,... One after another, another communication line protection tube is connected and added to extend the required length.

[0022]

【Example】

(Embodiment 1) Embodiment 1 of the present invention, a joint will be described with reference to FIGS. The joint 1A of the communication line protection pipe of the first embodiment shown in FIG.
It is used when it is drawn into the accommodation hole 40 of the outer pipe 4 (cylindrical steel pipe) shown in FIGS. 2 and 3 and is extended in the axial direction (longitudinal direction) P to a desired length.

The joint 1A includes a pair of first cylindrical insertion portions 10,
It comprises a second cylindrical insertion portion 11, and a central portion 12a which is provided in a middle between the first cylindrical insertion portion 10 and the second cylindrical insertion portion 11 and forms a ring-shaped ridge. First cylindrical insertion portion 10 and second
The cylindrical insertion portion 11 is an outer peripheral surface 100, 110 that is inserted into each of the holes 20, 20 of the pair of communication line protection tubes 2, 2 to be connected and abuts on the inner peripheral surfaces 21, 21 thereof. With.

First cylindrical insertion portion 10, second cylindrical insertion portion 11
Have an outer diameter D1 of 56 mm and an inner diameter d1 of 52
mm, thickness t1 is 2 mm, and length L1 in the axial direction P is 105.
mm. The central portion 12a has, on both sides thereof, a first vertical surface 16 connected to the first cylindrical insertion portion 10 and a second vertical surface 17 connected to the second cylindrical insertion portion 11, respectively. The first vertical surface 16 and the second vertical surface 17 are flange-shaped surfaces with which the end face 23 of the communication line protection tube 2 abuts, and the communication line protection tube 2 is connected to the first cylindrical insertion portion 10 and the second vertical surface 17. It functions as the positioning of the insertion depth at the time of insertion into the two cylindrical insertion portions 11.

The central portion 12a has an outer diameter D2 of 59 mm,
The thickness t2 is 4 mm, and the width w1 in the axial direction P (the first vertical surface 16
Is set at 3 mm. The outer peripheral surface 120a of the central portion 12a is flat and parallel to the axis P, and is the outer peripheral surface 22 of the communication line protection tube 2 inserted through the first cylindrical insertion portion 10 and the second cylindrical insertion portion 11. More than 0.5m
m lower position.

The communication line protection tube 2 has an outer diameter D3 of 60 mm, an inner diameter d3 of 56 mm, a thickness t3 of 2 mm, and a length L3 (see FIG. 2) of 4000 mm.
The outer tube 4 has an inner diameter d4 (see FIG. 3) of the accommodation hole 40 of 250.
mm. The joint 1 according to the first embodiment configured as described above.
According to A, it is used as follows. This joint 1
A is used at the time of a preparation work prior to the work of drawing the communication line protection pipe 2 into the outer pipe 4.

Here, this number of communication line protection tubes 2 to be drawn into the outer tube 4 is prepared in advance, and each communication line protection tube 2 has one end opening at both ends in the longitudinal direction P.
Either one of the first tubular insertion portion 10 and the second tubular insertion portion 11 of the joint 1A is inserted and connected (shown in a case where the first cylindrical insertion portion 10 is inserted and connected for explanation). . First of joint 1A
In order to connect the cylindrical insertion portion 10 to the communication line protection tube 2,
After applying an unillustrated adhesive to the outer peripheral surface 100 of the first cylindrical insertion portion 10, the connection is performed by inserting the bonding agent into the hole 20 of the communication line protection tube 2 to be connected and joining.

As described above, the communication line protection tube 2 before being drawn into the outer tube 4 has a large number of tubes each having the first cylindrical insertion portion 10 of the joint 2 connected to only one of the openings at both ends. A book is prepared. Then, first, the communication line protection pipe 2 for the first draw-in is set at the top (front side) of the other opening without the joint 1A.
As a result, one or a plurality of tubes arranged in parallel are simultaneously drawn into the receiving hole 40 of the outer tube 4 from the inlet 4a.

At this time, the communication line protection tube 2 is pulled in.
The second cylindrical insertion portion 11 of the joint 1A, to which the first cylindrical insertion portion 10 is previously connected to the opening side of the outer tube 4, extends from the inlet 4a of the outer tube 4 to the outside. After applying an unillustrated adhesive to the second cylindrical insertion portion 11 of the joint 1A protruding to the outside of the outer tube 4, the other opening of the other communication line protection tube 2 is inserted and joined. It is connected and added together.

Thereafter, the extended communication line protection tube 2 is drawn into the housing hole 40 of the outer tube 4 in the same manner as the communication line protection tube 2 for the first draw-in, and the outer tube 4 In the second cylindrical insertion portion 11 of the joint 2 protruding outside,
The step of adding another communication line protection pipe 2 is repeated. That is, the refilling operation and the drawing operation of the outer tube 4 into the accommodation hole 40 are repeated, and the communication line protection tube 2, the joint 1A, the communication line protection tube 2, the joint 1
A, communication line protection tubes 2... Are connected one after another, and another communication line protection tube 2 is connected and added, and is extended to a required length.

As described above, in the joint 1A, the hole 20 of the communication line protection pipe 2 is inserted into the outer peripheral surface 100 of the first cylindrical insertion portion 10 and the outer peripheral surface 110 of the second cylindrical insertion portion 11. , In the axial direction P. Here, in the joint 1A, the maximum outer diameter D2 of the central portion 12a is substantially the same as the outer diameter D3 of the communication line protection tube 2.

For this reason, the joint 1A does not have a configuration in which the plurality of communication line protection tubes 2, 2 are expanded in the radially outward direction when the plurality of communication line protection tubes 2, 2 are connected in the axial direction P. 40
No extra space is required in the radial outer direction R1 at the time of retraction, the accommodation space of the accommodation hole 40 of the outer tube 4 can be effectively utilized, and the required number of communication line protection tubes 2 is required.
Can be accommodated in a state of being installed in parallel with a margin.

Therefore, the joint 1 of the communication line protection pipe according to the embodiment will be described.
According to this, the communication line protection tubes 2 and 2 are connected between the communication line protection tubes 2 and 2 connected to the pair of first cylindrical insertion portions 10 and second cylindrical insertion portions 11. In order not to generate a large step projecting in the radially outward direction R1 from the outer peripheral surface 22, when drawing into the housing hole 40 of the outer tube 4, a seam (not shown) of the inner peripheral surface 41 of the housing hole 40 or another seam already drawn in The contact resistance can be reduced during the contact movement with another joint 1A or the like joined to the communication line protection pipe 2, so that the drawing operation can be performed easily, quickly, and efficiently. The large traction force can be greatly reduced, and a strong special traction machine is not required, which is advantageous in terms of cost.

In the hole 20 of the communication line protection tube 2,
The communication line (cable) 3 is accommodated. (Embodiment 2) Embodiment 2 of the present invention will be described with reference to FIG. In the joint 1B of the communication line protection pipe according to the second embodiment shown in FIG. 4, the tapered outer peripheral surface 120b forming the longest outer diameter of the central portion 12b moves toward the first cylindrical insertion portion 10 in the pull-in traveling direction ( The configuration is the same as that of the joint 1A of the first embodiment, except that the joint 1A is formed so as to be inclined (so as to be lower on the side opposite to the arrow Y1 in FIG. 1)].

The top portion O1 of the tapered outer peripheral surface 120b, which is the longest outer diameter of the central portion 12b, is slightly (0.1 mm to 0.5 m) from the outer peripheral surface 22 of the communication line protection tubes 2, 2.
m). According to the joint 1B of the second embodiment, the tapered outer peripheral surface 1 that is inclined so as to become lower toward the side opposite to the drawing-in progress direction when drawn into the housing hole 40 of the outer tube 4.
Even if 20b comes into contact with an unillustrated seam of the inner peripheral surface 41 of the housing hole 40 or another joint 1B joined to another communication line protection tube 2 that has already been drawn in, it does not hinder the drawing in. The effect of reducing the movement resistance by the sliding action at the time of contact can be obtained.

(Embodiment 3) A third embodiment of the present invention will be described with reference to FIG. The joint 1C of the communication line protection pipe according to the third embodiment shown in FIG. 5 has a front surface forming an inclined surface inclined from the top portion O2, which is the longest outer diameter of the central portion 12c, toward the first cylindrical insertion portion 10. A side tapered outer peripheral surface 120c;
A rear tapered outer peripheral surface 121c forming an inclined surface inclined toward the second cylindrical insertion portion 11, and an outer peripheral surface 10 of the first cylindrical insertion portion 10 from the front tapered outer peripheral surface 120c.
0, and the outer peripheral surface 11 of the second tubular insertion portion 11 from the rear tapered outer peripheral surface 121c.
The configuration is the same as that of the joint 1 </ b> B of the second embodiment, except that a second vertical surface 17 that is vertically connected to 0 is formed.

The top portion O2 is a communication line protection tube 2,
2 slightly (about 0.1 mm to 0.5 mm) from the outer peripheral surface 22
High. According to the joint 1C of the third embodiment, the joint 1C can be used without considering the directionality with respect to the axial direction P. That is, whichever of the first tubular insertion portion 10 and the second tubular insertion portion 11 is used on the forward side when retracted into the outer tube 4, the front tapered outer peripheral surface 120c or the rear tapered outer peripheral surface 120c. Either one of the surfaces 121c can obtain the same effect as the tapered outer peripheral surface 120b in the central portion 11b of the joint 1B of the second embodiment.

The joint 1A of the first embodiment, the second embodiment
In the joint 1B of the third embodiment and the joint 1C of the third embodiment, a case is shown in which a plurality of communication line protection pipes 2 are connected to each other in the axial direction P and are drawn into a cylindrical steel pipe as the outer pipe 4. However, the present invention is not limited to this. For example, FIG.
As shown in FIG. 7, the present invention can be applied to a substantially U-shaped concrete grooved body 4A having a lid 4b on which an upper opening 400 is removably mounted, or as shown in FIG. When the communication line protection tube 2 connected by using the outer tube 4 is drawn into the housing hole 40 of the outer tube 4 while simultaneously holding the plurality of tubes in a state of being arranged in parallel with each other, each of the plurality of tubes is circumferentially inserted. The guide member (guide laying guide for pipe laying) 5 having the spherical body 51 that slides and slides on the grip portion 50 gripped by the S and the inner bottom surface 410 of the housing hole 40 of the outer tube 4 can also be used.

[0039]

【The invention's effect】

(1) The joint according to the first aspect of the present invention includes a pair of insertion portions, and a center portion formed in the middle thereof with a ring-shaped ridge protruding from the outer peripheral surface of the pair of insertion portions. The central portion has a longest outer diameter substantially equal to the outer diameter of the communication line protection tube inserted through the pair of insertion portions.

For this reason, the outer peripheral surface of the communication line protection tube inserted and connected to the pair of insertion portions of the joint according to the first aspect and the outer peripheral surface of the central portion are substantially flush and connected. Between the outer peripheral surface of the communication line protecting tube and the outer peripheral surface of the central portion, the outer peripheral surface of the joint extends radially outward from the outer peripheral surface of the communication line protecting tube, as in the case of the conventional joint. It does not protrude and form a large step.

Therefore, by using the joint according to the first aspect, the connected communication line protection pipe can be connected with the joint at the inner peripheral surface of the accommodation hole when the outer pipe is drawn into the accommodation hole.
It does not catch on other joints or the like that are already joined to other communication line protection pipes that have already been drawn in, and can reduce the movement resistance at the time of drawing in as compared with the case where the conventional joint is used, quickly and easily. Work can be performed and workability can be improved.

The radial size of the joint is substantially the same as that of the communication line protection tube, and does not protrude radially outward from the outer peripheral surface of the communication line protection tube. The hole space can be effectively utilized, and the communication line protection tube can be held without reducing the number of drawn-in communication line protection tubes into the hole passage of the outer tube. (2) According to the joint of the second aspect, since the outer peripheral surface side of at least one of the protrusions has an inclined surface, the communication line protection pipe is pulled together with the joint into the housing hole of the outer pipe when the communication line protection pipe is drawn. By using it at the angle of inclination that becomes lower on the side opposite to the traveling direction, if it comes into contact with the joint on the inner peripheral surface of the accommodation hole or other joint already joined to the other communication line protection pipe that has been drawn in Also, it is possible to obtain the effect of reducing the movement resistance by the sliding action at the time of contact without inhibiting the drawing.

Therefore, according to the joint of the second aspect, substantially the same effect as that of the joint of the second aspect can be obtained. (3) According to the joint of the third aspect, at least one side surface of the ridge is a flange-shaped surface that contacts the end face of the communication line protection pipe inserted into the fitting portion. In addition to providing the same effect as that of the first joint, the joint also functions as an insertion positioning stopper for the communication line protection tube.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a communication line protection tube is connected in the axial direction using the joint of Example 1.

FIG. 2 is a perspective view showing a state where the communication line protection tube is connected in the axial direction using the joint of Example 1 in FIG. 1 and is drawn into a housing hole of an outer tube.

FIG. 3 shows a state in which the communication line protection tube is connected in the axial direction using the joint of the first embodiment in FIG. 1 and is drawn into the housing hole of the outer tube, and there is room in the space of the housing hole. Sectional drawing of a communication line protection tube and an outer tube.

FIG. 4 is a cross-sectional view showing a state in which communication line protection tubes are connected in the axial direction using the joint of the second embodiment.

FIG. 5 is a cross-sectional view showing a state in which a communication line protection tube is connected in the axial direction using the joint of the third embodiment.

FIG. 6 is an application example in which a communication line protection tube connected by using the joints of the first to third embodiments is applied to a substantially U-shaped concrete grooved body provided with a lid as an outer tube to be retracted and accommodated. FIG.

FIG. 7 is a usage example applied to a case in which a communication line protection tube is connected using the joints of the first to third embodiments and a guide member (pipe laying guide spacer) is attached to the outer tube and retracted into the outer tube. FIG.

FIG. 8 is a cross-sectional view showing a state in which communication line protection tubes are connected in the axial direction using a conventional joint.

9 is a perspective view showing a state where the communication line protection tube is connected in the axial direction using the conventional joint shown in FIG. 8 and is drawn into a housing hole of the outer tube.

FIG. 10 shows a state in which the communication line protection tube is connected in the axial direction using the conventional joint in FIG. 9 and is drawn into the housing hole of the outer tube so that there is no room in the space of the housing hole. Sectional drawing of a protection tube and an outer tube.

[Explanation of symbols]

1A, 1B, 1C ... joint 10a ... 1st cylindrical insertion part 1
0b: second cylindrical insertion portion 11: central portion 110: maximum outer peripheral surface 11
DESCRIPTION OF SYMBOLS 1 ... Tapered surface 112 ... 1st vertical surface 113 ... 2nd vertical surface 2 ... Communication line protection tube 3 ... Communication line (cable) 4
… Outer tube

Claims (3)

[Claims] 1. A tubular joint for axially connecting communication line protection tubes accommodating communication lines (cables) in a hole, wherein the cylindrical joint is a pair of connecting tubes for protecting the communication line. An outer peripheral surface which is inserted into each hole of the pipe and has an outer peripheral surface which comes into contact with the inner peripheral surface; And a central portion forming a ring-shaped ridge protruding from the outer peripheral surface of the insertion portion, and is divided on both sides by the central portion having the ridge. A communication line protection pipe joint characterized in that two communication line protection tubes to be connected to one of the outer peripheral surface and the other outer peripheral surface are inserted and joined. 2. The joint for a communication line protection pipe according to claim 1, wherein said ridge has an inclined surface inclined at least toward the outer peripheral side. 3. The communication line protection tube according to claim 1, wherein at least one side surface of the ridge is a flange-shaped surface with which the communication line protection tube end face inserted into the fitting portion abuts. Fittings.