JP3208649B2 - Perforated protective tube for cable burial - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to power, communication,
The present invention relates to a cable burying porous protection tube (hereinafter, simply referred to as a porous protection tube) used to protect cables when a plurality of transmission cables for television broadcasting are buried in a plurality of sites.

[0002]

2. Description of the Related Art When a transmission line is buried underground, as shown in FIG. 5, a buried groove 1 dug along a transmission line is used.
Are provided at important points of the second and the porous protective tubes M ', M'.
Are connected to each other to connect the hand holes 14, 14, and bury the buried groove 12 so that the porous protective tube M
, M 'form a plurality of cable insertion paths, and various cables are inserted in these cable insertion paths. The porous protective tube is made of ceramic, metal, synthetic resin and various materials and is formed firmly and firmly.The porous protective tubes are bolted together so as not to be separated from each other. In some cases, buffers 15, 15,... For absorbing bending moment against external force are interposed as a measure against earthquake.

[0003]

When the ground shakes due to an earthquake, vibration is absorbed by the bending moment absorbing packing at the connecting portion, so that the damage is minimized. When the ground fluctuates, the buried porous protective tubes are connected to each other via the packing for absorbing the bending moment, but cannot absorb the lateral fluctuation strain. When the connecting portion is displaced or pressure is applied in the longitudinal direction, the central portion of the continuously provided porous protective tube M 'is lifted up as shown in FIG. Depending on the degree of destruction, there is a possibility that the inserted cable 16 may be broken, such as protruding in a bent state. If the transmission line is disconnected, communication may be interrupted, or power supply may stop, leading to a secondary disaster.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a porous protection tube having an earthquake-resistant structure developed for the purpose of securing a transmission function without interrupting a transmission path even when an earthquake occurs. A pair of connecting boards provided with a plurality of cable insertion holes are arranged facing each other with a predetermined interval therebetween, and the corresponding cable insertion holes of the connection boards are individually formed by at least a tubular body having elasticity. At the same time, the connecting boards are connected to each other by a protective cover that is slidably attached to the outer cylinder and the inner cylinder, and the cylindrical body is arranged in the protective cover. Another object of the present invention is to make it possible to insert and connect an arbitrary portion in a transmission path formed by connecting protective tubes. As the cylindrical body, a rubber corrugated pipe alone or a rubber corrugated pipe in which a coil spring is incorporated coaxially with the corrugated pipe and closely attached to the inner peripheral surface thereof are preferably used.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a porous protective tube according to the present invention will be described with reference to the drawings. FIG. 1 is an exploded view showing constituent members of a perforated protective tube, and FIG. 2 is an assembled perforated protective tube, wherein 1 and 1 are square connecting substrates and 2 is a corrugated tube as a cylindrical body. The connection board 1 is made of metal and has four transmission cable insertion holes 3, 3,.
Are provided in the center and four corners, and on the side edges between the transmission cable insertion holes 3 and 3, respectively.
.. 4a are provided. Corrugated pipe 2
Has an inner diameter made of rubber having the same diameter as the transmission cable insertion hole 3, has flange portions 5 and 5 at both end edges, and is capable of extending and contracting in the length direction. Reference numeral 6 denotes a cover composed of an outer cylinder 6a and an inner cylinder 6b slidably fitted in the outer cylinder 6a, each having a cross section smaller than the connecting substrate 1 and formed into a square with a chamfered corner. Have been. Numerals 7 and 7 denote fixing plates which are tightly fixed to the inner surface of the connection board 1. Transmission cable insertion holes 3 and 3 and bolt insertion holes 4 of the connection board 1 are provided.
a and 4a are formed at positions corresponding to the transmission cable insertion holes 3 ', 3' and screw holes 8, 8, respectively. The recessed steps 9, 9,... Concentric with the flanges are formed to have outer peripheral shapes matching the inner circumferences of the outer cylinder 6a and the inner cylinder 6b, respectively.

[0006] Each of the above members is firstly provided with four corrugated tubes 2, 2, ... in a cover 6 in which an inner tube 6b is fitted into an outer tube 6a.
, And the ends of the corrugated pipes 2, 2,... Are respectively inserted into the transmission cable insertion holes 3 ', 3',. The fixing plates 7 and 7 are fitted into the step portions 9, respectively, are brought into close contact with the back surfaces of the connection substrates 1 and 1, and are fixed with bolts using the bolt insertion holes 4 a and 4 a and the screw holes 8. Next, one ends of the outer cylinder 6a and the inner cylinder 6b of the cover 6 are fitted into the fixing plates 7, 7, respectively, and screw holes 10, 10... 7 are screwed using the screw holes 11, 11...

The porous protective tube thus formed is shown in FIG.
As shown in (a) and (b), the cover 6, in which the outer tube 6a and the inner tube 6b slide relatively, allows the connection substrates 1 and 1 to move only in a direction perpendicular to the plate surface. The corrugated pipes 2, 2,... Are guarded by a cover 6 so that the corrugated pipes 2, 2,... The elasticity of the porous protective tube hardly changes even when an adult tries to compress it by applying weight, and is adjusted to be reduced by about 20 to 30% by applying a force of several tons.

At the time of constructing the transmission path, as shown in FIG. 4, a conventional porous protective tube M ', M' in which a porous protective tube M of the present invention is continuously installed in a dug buried groove 11 is provided. Between,
Arrange them so that they are inserted every few bolts.
The bolts 13, 13 are used to connect the handholes 14, 14, and so on. No special work is required, and the insulation between the inserted transmission lines is also reduced.
Perfect with rubber corrugated tube.

By connecting the porous protective tube of the present invention, even if the ground fluctuates due to an earthquake, the strain is absorbed by the expansion and contraction action to prevent deformation of the transmission line and secure the transmission path.

In the porous protective tube shown in the embodiment, a rubber corrugated tube is used as a tube having elasticity, and the outer periphery of the corrugated tube is guarded by a cover so that air can flow between the corrugated tube and the cover. It has a layered structure, but it is filled with foam resin between the corrugated pipe and the cover. Shape power can be increased.

Further, the material of the connecting board and the cylindrical body, the expansion and contraction structure of the cylindrical body, the connecting structure between the cylindrical body and the connecting board, and the like are not limited to the embodiments, and the number of cable insertion holes can be changed as appropriate. You can also set multiple lengths.

Further, the material and type of the porous protective tube to be connected can be arbitrarily selected, and the present invention may be applied to a transmission path having a plurality of cable insertion holes by bundling independent cable insertion tubes.

If the perforated pipe of the present invention is inserted and connected every several pipes to the conventional perforated pipe, distortion due to ground fluctuation is absorbed by expansion and contraction, and the transmission cable is protected. If a rubber corrugated tube is used for the cylinder, the insulation between the transmission cable insertion holes and the expansion and contraction function can be kept high. Further, if a coil spring is incorporated in the corrugated pipe, the influence of an external force can be eliminated.

[Brief description of the drawings]

FIG. 1 is an exploded view of a porous protective tube according to the present invention.

FIG. 2 is an explanatory view for assembling a perforated protective tube.

FIG. 3 is an explanatory view of an elastic structure shown by a cross section taken along line AA.

FIG. 4 is an explanatory diagram of a construction example.

FIG. 5 is an explanatory diagram of a conventional example.

FIG. 6 is an explanatory diagram of an example of destruction due to an earthquake.

[Explanation of symbols]

1, connecting board, 2, corrugated pipe, 3, 3 ', transmission cable insertion hole, 4, 4a, bolt insertion hole, 5, ...
Flange part, 6 cover, 6a outer cylinder, 6b inner cylinder, 7 fixing plate, 8 screw holes, 9 flange step fitting step, 10, 11 screw holes, M ··· Perforated protective tube (of the present invention);
..Buried grooves, 13 bolts, 14 hand holes,
15 ... buffer, 16 ... cable, M ... perforated protection tube (of the present invention), M '... perforated protection tube.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-93772 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02G 1/06, 9/06 F16L 1 / 00

Claims (3)

(57) [Claims] 1. A pair of connecting boards provided with a plurality of cable insertion holes are opposed to each other with a predetermined space therebetween, and the corresponding cable insertion holes of the connection boards are formed at least in a cylinder having elasticity. While individually connected by a body, the two connection boards are connected by a protective cover that is slidably assembled with the outer cylinder and the inner cylinder, and the cylindrical body is arranged in the protective cover, and a large number of A cable-embedding porous protection tube that can be inserted and connected to an arbitrary portion of a transmission path formed by connecting cable-embedding porous protection tubes in series. 2. The porous protective tube for burying a cable according to claim 1, wherein the cylindrical body is a rubber corrugated tube. 3. The cable-embedded porous protective tube according to claim 1, wherein the cylindrical body has a coil spring incorporated therein coaxially with a rubber corrugated tube in close contact with an inner peripheral surface.