JPH0731031A - Protective pipe for cable - Google Patents

Abstract

PURPOSE:To facilitate addition and replacement of cable while enhancing mechanical strength and watertightness through the use of a protective pipe comprising inner and outer tubes with a space therebetween. CONSTITUTION:Identically molded upper and lower half bodies 12 and 14 are combined 10 to constitute a protective pipe for cable. The combination 10 comprises an outer tube 16, a supporting wall 32 extending inward therefrom, and an inner tube 18 supported by an intermediate supporting wall 34 within the outer tube 16, wherein the cross-section perpendicularly intersecting the longitudinal center line is formed 180 deg. rotary symmetrical to an axis passing the center Y thereof. The supporting wall 32 is formed to contact tightly on the contact face thereof when the upper and lower half bodies 12, 14 are combined. Consequently, even when the impact of a pick acts on the outer tube 16, it is relaxed by the space existing between the inner and outer tubes 18, 16 before acting on the inner tube 18. The upper and lower half bodies 12, 14 are separated from each other by moving an L-shaped wall 42 outward at the tip thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable protection tube, and more particularly, to make it easy to add a cable or replace an already installed cable after laying a cable in the cable protection tube. It relates to a devised cable protection tube.

[0002]

2. Description of the Related Art When a cable or an electric wire (hereinafter, referred to as a cable including the electric wire) is buried in the ground, the cable is generally protected by a cable except for a special cable that is installed so as to be directly buried. It is buried in the ground in the form of being inserted into the pipe, and thus is protected from the outside.
Conventionally, when burying a cable, a general synthetic resin smooth tube or corrugated tube as shown in FIG. 5A is used as a cable protection tube. In most cases, the pipes are buried in the ground along the desired route and the cables are routed through the pipes. If such a general pipe is used as a cable protection pipe, the whole bulk becomes large, and it becomes necessary to increase the width and depth of the trench to be excavated,
As a result, the amount of civil engineering work at the site increases and the cost increases.
Therefore, a polyvinyl chloride perforated cable protection tube shown in FIG. 5 (b) in which a plurality of smooth tubes are integrated to reduce the bulk is also commercially available.

[0003]

By the way, after laying a cable, it is necessary to add a cable or replace a laid cable for reasons such as expansion of electrical equipment and increase in power requirement. Is often experienced. However, as long as the conventional cable protection tube is used, it is extremely labor-intensive and costly to add another cable in the same cable protection tube or replace the installed cable after laying the cable. there were. This is because all the cables that have already passed through the cable protection tube must be pulled out once, and then the cable to be added again or a new replacement cable must be routed through the cable protection tube together with the pulled out cable. It was Otherwise, for example, if you try to put the cable you want to add into the cable protection tube by itself, it will damage other cables, and if you try to pull out only the cable you want to replace, there is a great risk of damaging other cables as well. It was expensive.

Moreover, the conventional cable protection tube as shown in FIGS. 5 (a) and 5 (b) was extremely weak against mechanical force from the outside, especially impact force. In many cases, the cable protection pipe is buried in a place where a load acts on the laid cable protection pipe, for example, under the road. Therefore, it has been desired to provide a cable protection tube having high mechanical strength.

On the other hand, as a recent tendency, in consideration of disaster prevention against fire or the like and a demand for aesthetics, there are more cases where the cable is buried in the ground rather than being laid on the ground in the form of an overhead wire. Therefore, there is a strong demand to provide a cable protection tube having high mechanical strength and which allows easy addition and replacement of cables. Further, when water flows into the cable protection tube, the water enters the manhole or the electric device to which the cable is connected via the cable protection tube, which causes trouble. Therefore, it is also important that the cable protection tube has watertightness.

In view of the above situation, an object of the present invention is to provide a high cable protection tube having a sufficient mechanical strength and a watertightness, and further, after the cables are passed, the cables can be added or replaced. The purpose of the present invention is to provide a cable protection tube that is easy to perform.

[0007]

In order to achieve the above object, the cable protection tube according to the present invention is a cable protection tube composed of a combination of shaped bodies of the same shape paired together. , An outer cylinder and an inner cylinder supported in the outer cylinder by a support wall extending inward from the outer cylinder, and a cross-sectional shape orthogonal to the longitudinal centerline is 180 ° rotational symmetry about a symmetry axis passing through the center. And two of the supporting walls are arranged so as to extend from the inner cylinder to the outer cylinder along a plane including the axis of symmetry, and each of the molded bodies is formed. Has a contour obtained by dividing the double cylindrical body into upper and lower parts along a dividing surface along the wall cores of the two supporting walls, and has a hooking convex portion on one side edge and a hooking convex portion on one side edge. Each of the opposite side edges is provided with a hooking concave portion, and one hooking convex portion of the pair of molded bodies is fitted to the other hooking portion of the pair of molded bodies. A double cylinder is formed as a combination by fitting into the recesses and hooking with each other, and when the double cylinder is formed, the divided surfaces of the two support walls are in close contact with each other. It is characterized by being.

The cable protection tube according to the present invention can be used as a cable protection tube regardless of whether it is laid on the ground or buried in the ground, and particularly preferably used as a cable protection tube for underground buried. The number and shape of the inner cylinders are not particularly limited, and it is possible to arrange any number of inner cylinders in the outer cylinders. However, it is desirable that the shape of the inner cylinder has a circular cross section in order to increase the accommodation capacity and mechanical strength of the cable. The shape of the outer cylinder is not particularly limited and may be any shape. However, for convenience of stacking the cable protection tubes in a stack and stacking them in multiple stages, it is preferable that the cross section has a square or rectangular shape as described below. preferable. The number of support walls is
The number of sheets is arbitrary and is necessary for strength. In order to increase the mechanical strength, it is desirable that the support walls are provided radially from the inner cylinder to the outer cylinder at substantially equal angular intervals.

In a preferred embodiment of the cable protection tube of the present invention, the outer cylinder is formed in a square or rectangular shape in a cross section orthogonal to the longitudinal center line, and is provided on the side wall of the outer cylinder having no hook portion. A cable protection tube provided with a convex portion extending parallel to the longitudinal centerline and a concave portion having a shape that can be fitted into the convex portion and extending parallel to the convex portion When stacked on a protective tube, the convex portion and the concave portion of another cable protective tube are fitted into the concave portion and the convex portion of the cable protective tube, respectively, so that both cable protective tubes can be hooked. There is.

The cable protection tube of the present invention is preferably
A synthetic resin is used as a material and molded by atypical extrusion molding. More desirably, as in this example described later, a vinyl chloride resin blended with an acrylic resin is used to improve weather resistance, and even if it is used for a long period of time while being exposed to the atmosphere on the ground, it deteriorates. So that there is no

[0011]

According to the first aspect of the present invention, the cable protection tube is a double cylinder body including an outer cylinder and an inner cylinder, so that even if an impact force, for example, a pickaxe impact force acts on the outer cylinder. The impact force exerted on the cylinder is mitigated by the space existing between the outer cylinder and the inner cylinder, and the degree of impact is greatly reduced. Therefore, the cable protection performance is increased as compared with the conventional cable protection tube. Since the cable protection tube of the present invention is formed by a combination of a pair of molded bodies in which a double cylinder is symmetrically divided, a pair of molded bodies can be formed when a cable needs to be added or replaced. You can remove one side of your body and add or replace the cables you need. In other words, as in the past,
Pull out all the laid cables from the cable protection tube,
It is no longer necessary to run the newly added cable or the replaced cable together with the drawn cable in the cable protection tube. Therefore, adding cables,
Replacement is much easier than conventional cable protection tubes. Further, when forming the cable protection tube as a combined body, the pair of molded bodies are in close contact with each other at the division surfaces of the support wall, and form the cable protection tube in a form that prevents water from entering the inner cylinder from the outside. Therefore, the watertightness of the cable protection tube is high. More desirably, if a packing, for example, a thin rubber packing, is attached between the divided surfaces, the watertightness is further improved.

According to the second aspect of the present invention, since the cable protection tube is provided with a hooking portion on its outer cylinder, which can be hooked with another cable protection tube, the cable protection tubes can be stacked in multiple stages. It's easy.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail based on embodiments with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of the cable protection tube according to the present invention, and FIG. 2 is a sectional view taken along the line XX of FIG. As shown in FIG. 1, the cable protection tube 10 is composed of a pair of an upper half body 12 of an upper part and a lower half body 14 of a lower part. The upper half body 12 and the lower half body 14 are exactly the same long body molded body having the cross section shown in FIG.
The cable protection tube 10 is an upper half body 1 formed in the same shape.
One of the two or the lower half bodies 14 is turned upside down, and these are combined so that the inside faces each other. As a result, the cross-sectional shape of the cable protection tube 10 is, as shown in FIG. 2, rotationally symmetrical with respect to the axis of symmetry passing through the center Y of 180 °.

Assuming that the cable protection tube 10 has the cross-sectional shape shown in FIG. 2 and is continuously formed in the longitudinal direction indicated by Z in FIG. 1, the cable protection tube will be described below with reference to FIG. The configuration of 10 will be described. Upper half 12 and lower half 14
Is provided with an outer case 16 and two half-cylindrical inner cases 18, 18 that are obtained by dividing a cylinder into two equal parts, symmetrically with respect to the Y point. When the upper half body 12 and the lower half body 14 are combined, each inner body 18 constitutes an inner cylinder of the cable protection tube 10 and forms a space for accommodating a cable therein. Similarly, when the upper half body 12 and the lower half body 14 are combined, each outer case 16 constitutes an outer cylinder of the cable protection tube 10 which is a protection member for protecting the inner cylinder, and is, for example, an external cylinder. It first receives the impact force from
External force does not reach the inner cylinder. Since the upper half 12 and the lower half 14 have the same shape, the structure of the upper half 12 will be described below. The outer case 16 is formed in a channel shape composed of a strip-shaped plate wall 20 and side walls 22 and 22 standing upright from both sides thereof. Meanwhile, the inner body 18
Is arranged in the outer case 16 such that a line D connecting both end edges 24 and 26 thereof is parallel to the plate wall 20.

To support the inner case 18 in the outer case 16,
The two support walls 32, 32 extend from the edges 24, 24 of the two inner shells 18, 18 to the edges 2 of the side walls 22 of the outer shell 16, respectively.
8 and 30 and a plurality of intermediate support walls 34 extend from the two inner barrels 18 to the outer cylinder 16 radially and at substantially equal angular intervals. In addition, the two inner barrels 18, 18 are connected to each other at the end edges 26 facing the end edges 24 by a connecting wall 36. Board wall 2 of outer body 16
0, a convex ridge 38 extends in the longitudinal direction at a position where a line passing through the center of one inner case 18 and orthogonal to the line D intersects the plate wall 20. In addition, a concave groove 40 formed in substantially the same contour as that of the ridge 40 so as to be fitted thereto passes through the center of the other inner case 18 and a line orthogonal to the line D is a plate wall 20.
It extends in the longitudinal direction at a position intersecting with.

Further, as shown in FIG. 3 (a), the outer case 16 is provided with one of a pair of a concave portion and a convex portion forming a hooking portion at the end portions 28 and 30, respectively. As one of the hook portions, the end portion 28 of the one side wall 22 of the outer case 16 is provided with the L-shaped wall 42.
And a wall 44 of a transition portion that transitions to the support wall 32 to form a groove-shaped recess 46. Furthermore, the L-shaped wall 4
2 has a small protruding portion 48 protruding at a right angle from the wall body toward the inside of the recess at the tip thereof. As shown in FIG. 3B, the other end of the side wall 22, which is the other of the hooking portions, has a wedge-shaped convex portion 50 that fits into the concave portion 46 and the convex portion 5.
The base end portion of 0 is provided with a step portion 54 which is a step toward the inside.

With the above structure, as shown in FIG. 1, the upper half body 12 and the lower half body 14 are combined to form the cable protection tube 1.
Pushing the end 30 of the lower half 14 into the end 28 of the upper half 12 to form a 0, as shown in FIG.
The convex portion 50 of the end portion 30 fits into the concave portion 46 of the end portion 28 so as to spread the L-shaped wall 42, and at the same time, the protruding portion 48 projects into the step portion 54 so that the convex portion 50 can be easily removed from the concave portion 46. The upper half body 12 and the lower half body 14 are hooked to each other so as not to come off. On the other hand, when removing the upper half body 12, by pointing the tip of the L-shaped wall 42 outward with an appropriate tool,
The upper half 12 and the lower half 14 can be easily separated. Incidentally, FIG. 3B is shown upside down for convenience.

The supporting walls 32, 32 extending from the ends 28, 30 of the outer case 16 to the end 24 of the inner case 18 are shown in FIG. 3 (c) when the upper half 12 and the lower half 14 are combined. like,
The contact surfaces 56 are formed so as to come into close contact with each other, and in order to improve the watertightness, a thin plate-shaped rubber packing can be mounted between the contact surfaces 56 when assembled. When a rubber packing is attached and used, it is desirable to engrave many fine grooves in parallel on the contact surface 56 by knurling to improve familiarity with the rubber packing.

When the upper half body 12 and the lower half body 14 are combined as shown in FIG. 1, the connecting wall 36 of the upper half body 12 and the connecting wall 36 of the lower half body 14 are as shown in FIG. , Are formed so as to be hooked on each other. That is, the connecting wall 3
6 is provided at a position deeper than the end surface of the inner case 18, and a convex portion 60 is provided on the outer surface of the end of one of the inner cases 18. As a result, the upper half 12 and the lower half 14
When combined with each other, the convex portion 6 projectingly provided on one inner case 18
The zero fits on the outer edge of the other inner barrel 18 and is hooked together so that the upper half 12 and the lower half 14 do not translate relative to each other.

In order to connect the cable protection tube 10 to the next cable protection tube 10 and lay it long in the longitudinal direction, a joint is often used at the connecting portion. In such a case, for example, a tubular joint having an outline matching the outer shape of the cable protection tube 10 on its inner periphery is prepared, both cable protection tubes 10 connected to the joint are fitted, and the joint and the cable protection tube 10 are inserted. It is also possible to fasten them with bolts and nuts. For convenience of adopting such a connecting method, a groove-shaped recess 62 is provided in the center of the plate wall 20 of the outer case 16. When fixing the joint and the cable protection tube 10 with the bolt and the nut, the recess 62 accommodates the head of the bolt (not shown) or the nut (not shown), and the cable protection tube 1
Avoid stacking 0s.

Although the cable protection tube 10 shown in FIG. 1 is shown in a single stage, the same cable protection tube 10 (not shown) can be stacked on the cable protection tube 10. When stacked, the raised portion 38 of the cable protection tube 10 shown in FIG. 1 fits into the groove 40 of the cable protection tube 10 that is stacked on top, and is stacked on the groove 40 of the cable protection tube 10 that is shown in FIG. The raised portion 38 (not shown) of the cable protection tube 10 is fitted. As a result, the cable protection tube 10
And the cable protection tube 10 stacked on top of each other are locked to each other, and the cable protection tube is prevented from moving in parallel and the stacking collapse.

In the present embodiment, the cable protection tube 10 is formed by atypical extrusion using a die having an opening having the same shape as the cross section of the upper half body 12 or the lower half body 14 shown in FIG. ing. As the material, for example, a vinyl chloride resin having a weather resistance improved by mixing an appropriate amount of acrylic resin is used. By improving the weather resistance, not only the cable protection tube 10 can be used for underground embedding, but also the cable protection tube 10 can be used for a long period of time without deterioration even when laid on the ground exposed to the atmosphere. Outer body 1 mentioned above
6, inner body 18, support wall 32, intermediate support wall 34, connecting wall 3
6 and other parts all function as strength members constituting the cable protection tube 10, and their dimensions are the inner body 18
It is set according to the size of the cable to be housed in and the required mechanical strength. In this embodiment, the number of the inner shells 18 is two, but it may be one, or conversely, an arbitrary number of the inner shells 18 of three or more may be arranged in parallel.

In the present embodiment, the cable protection tube 10 is formed of a combination body in which the upper half body 12 and the lower half body 14 formed in the same shape are hooked by the hooking portions of the respective side walls 22. There is. Therefore, the cable protection tube 10 can be formed by molding a molded body having the same shape as the half body 12 or 14. Therefore, the manufacturing cost of the cable protection tube 10 including the mold cost and the molding cost is low. If you want to replace the additional cable or the laying cable after passing the cable through the cable protection tube 10,
By simply removing the upper half 12, the cables can be added or replaced without the need to pull out the entire laying cable as in the conventional case.

In the present embodiment, the combined cable protection tube 10 has a cross-sectional shape in which the support wall 32, the intermediate wall 34 and the connecting wall 36 extend radially around the inner case 18. Therefore, the mechanical strength against load is high. Therefore, even if the soil cover is small, that is, even if the burial depth is shallow, it is possible to sufficiently withstand the external load from the wheels of the automobile. Further, since the cable is protected by the double structure of the outer case 16 and the inner case 18, it has a structure that is strong against an impact force from the outside, such as a pickaxe.

The space between the outer case 16 and the inner case 18, for example, the space 70 shown in FIG. 2, can be used as a space for accommodating a control cable, a communication cable, etc. after the cable protection tube 10 is laid. Since the inner case 18, the support wall 32, the intermediate support wall 34, the connecting wall 36, and the like are arranged at intervals from each other, the cooling time and deformation are short during molding.

[0026]

According to the first aspect of the invention, since the cable protection tube is constructed as a double cylinder having a space between the outer cylinder and the inner cylinder, the impact force, for example, the impact force of a pickaxe. Even if acts on the outer cylinder, the degree of impact on the inner cylinder is significantly reduced, thereby improving the cable protection performance as compared with the conventional cable protection tube. Since the cable protection tube of the present invention is formed by a combination of a pair of symmetrically divided double cylinders, the cable protection tube is formed by molding one molded body having the same shape. be able to. Therefore, the cable protection tube of the present invention has a low manufacturing cost including mold cost, molding cost and the like. Further, when it becomes necessary to add or replace a cable, one of the paired combinations can be removed to add or replace the required cable. Therefore, it becomes very easy to add and replace the cable, and the cost required for it becomes low. Since the pair of molded products adheres closely to each other on the dividing surface of the support wall, it has watertightness as a cable protection tube, and external water may enter the manhole or electrical equipment to which the cable is connected through the cable protection tube. To be prevented.

According to the second aspect of the present invention, since the cable protection tube is provided with a latching portion on its outer cylinder, which can be latched with another cable protection tube, it is possible to stack the cable protection tubes in multiple stages. It is easy and requires less space. As a result, the size of the trench to be excavated is reduced, and excavation costs are reduced. According to the invention of claim 3, by using a vinyl chloride resin mixed with an acrylic resin as a material of the molded body, the weather resistance is improved, and even if it is used for a long time in a state of being exposed to the atmosphere on the ground, it deteriorates. There is nothing to do.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a cable protection tube according to the present invention.

2 is a cross-sectional view of the cable protection tube of FIG. 1 taken along arrow XX.

FIG. 3 shows a configuration of a latching portion for mutually latching a pair of molded bodies forming the cable protection tube shown in FIG. 1, and FIG. 3 (a) shows a latching recess provided on one side wall, FIG. 3B is a cross-sectional view showing a state in which the latching convex portion provided on the other side wall is latched, and FIG.

FIG. 4 is a cross-sectional view showing a configuration of a connecting wall that connects the inner shells to each other.

FIG. 5 (a) is a perspective view showing a conventional cable protection tube, and FIG. 5 (b) is a perspective view showing another conventional cable protection tube.

[Explanation of symbols]

 10 Example of Cable Protective Tube According to the Present Invention 12 Upper Half Body 14 Lower Half Body 16 Outer Body 18 Inner Body 20 Plate Wall 22 Side Walls 24, 26 Inner Body Edge 28, 30 Side Wall Edge 32 Support Wall 34 Intermediate Support wall 36 Connection wall 38 Raised ridge 40 Groove 42 L-shaped wall 44 Wall of transition part 46 Groove-shaped recessed portion 48 Projection portion 50 Wedge-shaped convex portion 54 Step portion 56 Support surface of contact wall 58 Wide groove-shaped recessed portion 60 Convex portion 62 Central concave portion

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuo Sadamitsu 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Noriho Furukawa 4-83, Shibaura, Minato-ku, Tokyo No. Kandenko Incorporated (72) Inventor Katsuo Oshi 4-83-3 Shibaura, Minato-ku, Tokyo Kandenko Incorporated (72) Inventor Eizo Date 4-83-3 Shibaura, Minato-ku, Tokyo Shares Company Kandenko (72) Inventor Yasushi Kaminaga 4-83-3 Shibaura, Minato-ku, Tokyo Kandenko Ltd.

Claims (3)

[Claims] 1. A cable protection tube comprising a combined body (10) in which formed bodies (12, 14) of the same shape are paired and combined with each other, wherein the combined body comprises an outer cylinder (16) and an inner cylinder from the outer cylinder. An inner cylinder (18) supported in the outer cylinder by supporting walls (32, 34) extending in a direction, and a cross-sectional shape orthogonal to the longitudinal centerline is 180 ° rotationally symmetric with respect to an axis of symmetry passing through the center. A double cylindrical body is formed, and two of the support walls (32) are arranged so as to extend from the inner cylinder to the outer cylinder along a plane including the axis of symmetry, Each of the molded bodies has a contour obtained by dividing the double cylindrical body into upper and lower two along a dividing surface (56) along the wall cores of the two supporting walls, and one side edge (30). ) On the hook (5
0) to the other side edge (28) opposite to the one side edge.
And a latching recess (46) respectively, and one latching protrusion of one of the pair of molded bodies is fitted to the other latching recess of the pair of molded bodies to latch each other, thereby forming a combination. And the double cylinder is formed, and when the double cylinder is formed, the split surface (56) of the two support walls is formed so as to be in close contact with each other. . 2. The outer cylinder is formed in a square or rectangular shape in a cross section orthogonal to the longitudinal centerline, and the longitudinal center is formed on the side wall (20) of the outer cylinder which does not have the hooking portion. A convex portion (38) extending parallel to the line, and a concave portion (40) having a shape that can fit into the convex portion and extending parallel to the convex portion (38), and the cable protection tube is provided separately. When it is stacked on the same cable protection pipe, the convex portion and the concave portion of the other cable protection pipe are fitted into the concave portion and the convex portion of the cable protection pipe, respectively, so that both the cable protection pipes can be hooked. The cable protection tube according to claim 1, wherein the cable protection tube is provided. 3. The cable protection tube according to claim 1 or 2, wherein the cable protection tube is formed of a vinyl chloride resin containing an acrylic resin.