JP5419508B2 - Cable protective pipe and cable protective conduit - Google Patents

Description

  The present invention relates to a cable protection pipe and a cable protection pipe for protecting a communication cable.

  A communication cable such as a telephone line is composed of a plurality of trunk cables connecting between telephone offices, and a plurality of lead-in cables branched from the trunk cable and drawn into a building such as a house or a store. It is buried under the road surface for the safety of traffic such as landscapes and cars. The expansion of underground communication cables will be further promoted in the future, and it is thought that various buried pipes will be buried in places where they are densely buried in the ground, or placed under the road surface of narrow roads. However, in view of such circumstances, for example, a protective pipe as disclosed in Patent Document 1 below is provided as a compact underground cable protective pipe that can efficiently store a cable wire. .

The protective tube main body of the cable protective conduit disclosed in Patent Document 1 can accommodate the retracting cable 70 and the trunk cable 80 in a single protective tube main body 101 as shown in FIG. There is a structure in which ribs 105A and 105B are provided on the inner wall surface 101a of a single-layer pipe. The protective tube main body 101 is provided with a separator 102 for dividing the inside of the protective tube main body 101 into upper and lower parts, and constitutes a cable protective conduit 100. In the cable protection conduit 100, when embedment, the drawing cable 70 is accommodated in the upper space 103 in the protection tube main body 101, and a sheath tube 81 is disposed in the lower space 104 and the sheath tube 81. A main line cable 80 is accommodated therein.
The protective tube main body 101 is made of a synthetic resin material having high strength such as hard vinyl chloride.

The ribs 105 </ b> A and 105 </ b> B are provided so as to protrude inward of the protective tube main body 101 and extend in a direction in which the protective tube main body 101 extends.
On the other hand, the separator 102 has a plate-like shape, and both side edges that come into contact with the inner wall 101a of the protective tube main body 101 are formed to have the concave stripes 106A and 106B along the ribs 105A and 105B and the inner wall 101a. Yes.

  Therefore, when the separator 102 is inserted into the protective tube main body 101, the ribs 105A and 105B of the inner wall surface 101a of the protective tube main body 101 engage with the concave strips 106A and 106B on both side edges of the separator 102, Even if the separator 102 tries to rotate in the protective tube main body 101, the separator 102 is fixed in the protective tube main body 101 so as not to rotate due to the engagement, and the cable disposed in the protective tube main body 101 is stably installed. be able to.

JP 2008-67455 A

  By the way, according to the cable protection conduit 100 disclosed in Patent Document 1, when a load or impact is applied to the protection tube main body 101, a load is applied to the separator 102 by the drawing cable 70. Therefore, as shown in FIG. 5 (b), a force (in the direction of the arrow in the figure) that the protective tube main body 101 tries to move relative to the separator 102 is generated. Thus, there is a problem that a crack occurs in this portion and the protective tube main body 101 is broken.

  The present invention has been made in view of the above circumstances, and even when an external load or impact is applied, it is difficult to cause breakage at the portion where the rib on the inner wall surface of the cable protection tube is formed, and the compact and The object is to provide a cable protection pipe and a cable protection pipe that can appropriately protect the cable line.

In order to achieve the above object, the present invention provides the following means.
The cable protection tube according to the first aspect of the present invention is a cable protection tube having an internal space in which a cable is accommodated, and can lock a separator for partitioning the internal space on an inner wall surface. An inner layer pipe having a rib, and a shock absorbing layer laminated on the outside of the inner layer pipe,
An outer layer pipe laminated outside the buffer layer, and the thickness of the buffer layer is set in a range of 3% to 33% of the total thickness of the inner layer pipe, the buffer layer, and the outer layer pipe, And the thickness of the outer layer pipe is set to 10% or more and 77% or less of the total thickness of the inner layer pipe, the buffer layer and the outer layer pipe, and the thickness of the buffer layer and the thickness of the outer layer pipe The total is set to be not less than 13% and not more than 80% of the total thickness of the inner layer tube, the buffer layer, and the outer layer tube .
The cable protection tube according to the first aspect of the present invention is the impact resistance improving resin in which the inner layer tube is made of a material mainly composed of an inorganic filler-containing vinyl chloride resin , and the buffer layer has rubber properties. It may be made of a vinyl chloride resin containing or a thermoplastic elastomer .
In addition, the cable protection conduit according to the second aspect of the present invention is characterized in that a separator is disposed so as to be engaged with the rib of the cable protection tube of the present invention.

  According to the cable protective tube of the present invention, when an impact or the like is applied to the protective tube from the outside, the impact force is absorbed by the buffer layer, so that the rib on the inner wall surface of the cable protective tube is formed. There is an effect that it is difficult to cause breakage at a location, and a cable that is compact and appropriately buried in the ground can be protected.

These are the perspective views of the protective tube for cables shown as one Embodiment of this invention. (A) is sectional drawing which shows the protective pipe line for cables which provided the separator in the internal space of the protective pipe for cables, (b) is a rib and a concave line engaging in drawing of (a). FIG. These are the protective conduits for cables of this invention, Comprising: It is sectional drawing which showed the state which penetrated the cable wire. These are the schematic block diagrams which show the manufacturing apparatus of the protective pipe | tube for cables by this invention. (A) is sectional drawing which shows the conventional cable protection pipeline, (b) is an expanded sectional view which showed the convex part periphery part.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a protective tube for a cable (hereinafter referred to as “protective tube main body”) 1 shown as an embodiment of the present invention. FIG. 2 (a) is an internal space of the protective tube main body 1. It is sectional drawing which showed the protective conduit A for cables which has arrange | positioned the separator 60 in FIG.

  The protective tube main body 1 includes an inner layer tube 2, a buffer layer 3 stacked on the outer side of the inner layer tube 2, and an outer layer tube 4 stacked on the outer side of the buffer layer 3.

As shown in FIG. 1, ribs 5 </ b> A and 5 </ b> B extending in the direction in which the inner layer tube 2 extends are formed on the inner wall surface 2 a of the inner layer tube 2.
These ribs 5A and 5B are for locking a separator 60 which will be described later. As shown in FIG. 1 and FIG. It is formed so as to protrude and inward of the inner layer pipe 2.
As shown in FIG. 2B, the ribs 5A and 5B have a substantially trapezoidal cross-sectional shape, the width of the root portion is larger than the width of the tip, and the inclined surfaces 5s, 5u, and The top surface 5t is configured.

The protective tube body 1 is formed by an extrusion method described later.
The inner tube 2 is made of a synthetic resin material with good dimensional stability and strength, such as hard vinyl chloride containing calcium carbonate, and various cable wires are buried under the road surface of the road. It is used to house and protect the cable from underground loads and groundwater.
As the material of the inner tube 2, other than the above, a vinyl chloride resin having thermoplasticity, or a vinyl chloride resin containing an inorganic filler such as talc, mica, silica, and alumina can be used.

The buffer layer 3 protects the inner layer pipe 2 from external loads and impacts when the cable protection conduit A is buried in the ground. As a material of the buffer layer 3, when a load or an impact force is applied to the outer layer pipe 4, a slight radial or rotational direction of the entire protective tube body 1 is provided between the outer layer pipe 4 and the inner layer pipe 2. Desirable to allow relative movement and absorb impact etc., for example, vinyl chloride resin containing impact resistance improving resin (reinforcing material) having rubber properties such as MBS, ABS, acrylic rubber, chlorinated polyethylene, EVA, etc. Alternatively, thermoplastic elastomers such as polyester elastomers, polyurethane elastomers, polyamide elastomers, styrene butadiene styrene elastomers, and olefin elastomers can be employed.
When the thickness of the buffer layer 3 is less than 3% of the thickness of the protective tube main body 1 (the total thickness of the inner layer tube 2, the buffer layer 3, and the outer layer tube 4), the buffer layer 3 is sufficiently thick against impact. If the buffering action is difficult to obtain and is thicker than 33%, the strength of the tube is reduced. Therefore, in order to appropriately absorb the impact force and load in the buffer layer 3, it is desirable that the thickness is set in a range of 3% to 33% of the thickness of the protective tube body 1.

The outer layer tube 4 is laminated outside the buffer layer 3 and protects the buffer layer 3 and the inner layer tube 2.
As the material of the outer layer pipe 4, the same material as that of the inner layer pipe 2 can be adopted, but it has an excellent elastic modulus and has load resistance, mechanical strength, wear resistance, chemical resistance, and the like. For example, a chlorinated vinyl chloride resin having a chlorination degree of 55% or more and not exceeding 70%, or an impact resistance improving resin having rubber characteristics such as MBS, ABS, acrylic rubber, chlorinated polyethylene, EVA and the like ( It is also possible to employ a chlorinated vinyl chloride resin containing a reinforcing material.
Further, when the thickness of the outer layer tube 4 is less than 10% of the thickness of the protective tube main body 1, it is difficult to sufficiently obtain the impact resistance of the outer layer tube 4. Therefore, the thickness of the outer layer pipe 4 is preferably set to 10% or more of the thickness of the protective pipe body 1.
Further, if the sum of the thickness of the buffer layer 3 and the thickness of the outer layer tube 4 exceeds 80%, the dimensional stability of the ribs of the inner layer tube 2 decreases. Therefore, it is desirable to set the sum of the wall thicknesses within a range not exceeding 80% of the protective tube main body 1.

  As shown in FIG. 2A, the separator 60 is formed of a single plate-like body, and is inserted so as to partition the internal space of the inner layer tube 2 into upper and lower spaces P and Q. As the material of the separator 60, the same material as that of the inner layer tube 2 can be used, but as the other material, a vinyl chloride resin composition having a polymerization degree in the range of 800 to 2400 that does not include an inorganic filler such as calcium carbonate is used. You can also.

  As shown in FIG. 2A, the plate-like body constituting the separator 60 is sandwiched between inclined portions 60a and 60b that are slightly inclined toward the center and downward of the pipe line of the tube main body, and the inclined portions 60a and 60b. And a horizontal portion 60c located at the center of the pipe line, and concave strips 60A and 60B that are connected to these and hold and fix the entire separator 60 at the inner center of the inner layer pipe 2.

As shown in FIG. 2 (b), in the groove 60A, a plate portion 60h connected to the inclined portion 60a and formed along the inner wall surface 2a abuts on the rib 5A and bends along the upper surface 5s. Plate portion 60i, plate portion 60i is bent downward and plate portion 60j is bent along top surface 5t of rib 5A, and plate portion 60j is bent toward inner wall surface 2a and plate portion 60k is bent along lower surface 5u of rib 5A. The plate portion 60k is again brought into contact with the inner wall surface 2a and bent, and is continuously provided with a plate portion 60l formed along the inner wall surface 2a.
Under this configuration, the recess 60A is brought into close contact with the rib 5A and locked.

  The concave strip 60B has a symmetrical shape with the concave strip 60A, and its configuration is the same as that of 60A.

  The protective tube main body 1 and the separator 60 constitute a cable protective conduit A.

Next, a method for manufacturing the protective tube main body 1 having the above-described configuration will be described with reference to FIG.
FIG. 4 is a schematic configuration diagram showing the manufacturing apparatus 10 for the protective tube main body 1.
In the manufacturing apparatus 10, a resin material for forming the inner layer tube 2 is supplied to the first extruder 11, a resin material for forming the buffer layer 3 is supplied to the second extruder 12, and the third extruder 13 is supplied with the resin material. Are supplied with resin materials for forming the outer tube 4. These resin materials are each heated and melted and shaped into a multilayer tube shape with ribs formed on the inner wall surface by a die 14 for forming a ribbed three-layer tube attached to the tip of each extruder, It is sent into the VAC water tank 15. In the VAC water tank 15, the protection tube main body 1 is cooled in a state where the shape of the tube is maintained by the negative pressure suction of the guide tube, and is further cooled in the cooling water tank 16. Thereafter, the protective tube main body 1 is dried by blowing air from a blower (not shown), further cooled by the cooling water tank 17, taken in one direction by the take-up machine 18, and applied to the outer peripheral surface of the protective tube main body 1 by the marking device 19. Printing is performed as appropriate, and the product is cut into a predetermined length by the cutting machine 20 to obtain a product.

  The separator 60 is horizontally inserted into the central portion of the protective tube main body 1 manufactured as described above, so that the cable protective conduit A according to the present embodiment is obtained.

  Examples of various cables accommodated in the cable protection conduit A configured as described above include, for example, a plurality of trunk cables 80 connecting between telephone offices, branches from the trunk cables, and houses, stores, etc. There are a plurality of retracting cables 70 that are pulled into the building. The cable protection conduit A is used, for example, embedded in the ground. At this time, as shown in FIG. 3, as shown in FIG. 3, the lead-in cable 70 is divided into two by a separator 60. The main line cable 80 is accommodated in the lower space Q located below in a state where it is inserted into the sheath tube 81 one by one or more. Is done.

When a load or impact is applied to the cable protection conduit A from the outside, the outer layer pipe 4 receives the impact force as it is. The impact force applied to the outer layer pipe 4 is a buffer layer. 3 is absorbed and transmitted to the inner tube 2 in a state where the impact force is weakened.
That is, the inner layer tube 2 and the outer layer tube 4 can be moved slightly in the radial direction by the buffer layer 3, and can also move relative to each other in the rotational direction around the axis of the tube. It will be suppressed by the relative movement.

Therefore, according to the protective tube main body 1 of the present invention, it is possible to avoid applying a load or damaging the root portion of the ribs 5A and 5B of the inner layer tube 2.
Further, according to the protective tube main body 1 of the present invention, since the influence on the inside of the inner layer tube 2 is reduced even if a load or impact is applied to the protective tube main body 1 from the outside as described above, the ribs 5A and 5B and the concave portions are recessed. Engagement with the strips 6A and 6B can be further strengthened.

A Protective conduit for cable 1 Protective tube body (protective tube for cable)
2 Inner layer pipe 2a Inner wall surface 3 Buffer layer
4 Outer pipe 5A, 5B Rib 60 Separator 70 Pull-in cable 80 Trunk cable

Claims (3)

A cable protection tube having an internal space in which a cable is stored,
An inner tube having a rib that can lock a separator for partitioning the inner space on the inner wall;
A shock absorbing buffer layer laminated on the outside of the inner tube;
An outer tube laminated on the outside of the buffer layer ,
The wall thickness of the buffer layer is set in the range of 3% to 33% of the total thickness of the inner layer tube, the buffer layer, and the outer layer tube, and the wall thickness of the outer layer tube is set to the inner layer tube, the buffer layer, and the buffer layer. It is set to 10% or more and 77% or less of the total thickness of the outer layer pipe, and the total thickness of the buffer layer and the outer layer pipe is the total thickness of the inner layer pipe, the buffer layer, and the outer layer pipe. A protective tube for cables characterized by being set to 13% or more and 80% or less . In the protective pipe for cables according to claim 1,
The inner layer tube is made of a material mainly composed of an inorganic filler-containing vinyl chloride resin ,
A protective tube for a cable, wherein the buffer layer is made of a vinyl chloride resin containing an impact resistance improving resin having rubber characteristics , or a thermoplastic elastomer .   A cable protection conduit according to claim 1 or 2, wherein a separator is disposed to be engaged with the rib.

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