JPH0456081A - Cable connecting structure - Google Patents

Abstract

PURPOSE:To connect cables well by improving seal effect at a cable insertion part of an end plate, and making the end plate to correspond to cables having different outer diameter from each other without changing size of the end plate. CONSTITUTION:Since a bushing 22 made of the elastic material such as rubber is engaged with a through hole 20 formed in an end plate 12, in the case that the end plate 12 receives heat cycle to repeat the expansion and the shrinkage, this expansion and shringkage is absorbed by the elastic force of the bushing 22. Since flange parts 26, 28 are formed in both sides of the bushing 22, seal effect is generated. Furthermore, for cables 6 having different outer diameter, several kinds of bushing 22 with a cable insertion hole 24 having different diameter are prepaired previously, and since a diameter of the through hole 20 of the end plate 12 is manufactured in response to an outer diameter of the bushing 22, the end plate 12 in one kind form can correspond to any cable.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a cable connection structure that improves the airtightness of a connection portion for connecting optical fiber cables, metal cables, and the like.

<Prior Art> In general, when transmitting signals, electric wires, etc. over long distances using optical fiber cables or metal cables, it is necessary to interconnect each cable.

If moisture gets into the connection part of the cable, the insulation resistance of the metal cable will drop, causing crosstalk or breaking of the cable due to electrolytic corrosion. Furthermore, optical fiber cables have problems such as increased transmission loss.

Therefore, in the prior art, as shown in FIGS. 3 and 4, a structure is provided in which the connecting portion of the cable can be kept airtight. This conventional example has a cylindrical plastic connection case 1, and an opening/closing slit 2 for inserting a cable is formed over the entire length of this connecting case l in the longitudinal direction, and a flange 3 of this opening/closing slit 2 Fastening metal fittings 4 are inserted from the left and right sides, and both fastening metal fittings 4 are fastened with a band 5. Also, inside the connection case 1, there are a core connection part 8 of the cable 6 and a jacket grip part IO.
is provided. On the other hand, plastic end plates 12 are provided at both longitudinal ends of the connection case 1 to seal the openings of the connection case 1.
2nd cable insertion hole! A cable 6 is inserted through 4. Each end plate 12 described above includes a pair of abutting members 15,
I6, and both abutting members 15 and 16 are integrally fastened with a wrapping band 18.

When connecting the cables 6 to each other, the core wires of the cables 6 are connected at the core wire connection part 8, and the jacket is gripped by the jacket grip part 1O, while the end plate 12 of the cable 6 is attached. Clay sealing material I9 formed into a tape shape at the location
Also, after attaching a sealing material 19 made of the same material to the opposing surfaces of the abutting members 15 and 16 that constitute the end plate 12 and abutting both the abutting members 15 and 16, the two are joined together with the wrapping band 18. to be concluded. Further, a rod-shaped sole material I9 made of the same material is wrapped around the outer peripheral portion of the end plate 12. Then, the above-mentioned core wire connection part 8 and jacket gripping part IO are housed in the connection case 1, and the outer periphery of the end plate 12 is surrounded by the end of the connection case 1. Then, a bar-shaped sealing material made of the same material as above is interposed on the opposing surface of the opening/closing slit 2, and then the fastening fittings 4 are inserted from the left and right into the collar 3 of the opening/closing slit 2 and fastened with the band 5. . As a result, the inside of the connection case I is sealed.

<Problems to be Solved by the Invention> As described above, in the past, a clay sealing material 1 was used between the cable 6 and the end plate 12 provided at both ends of the connection case l.
9, airtightness was maintained.

However, since the sealing material 19 is made of clay, once it is deformed during placement, it will not return to its original shape.

Therefore, for example, if the end plate 12 repeatedly expands and contracts due to thermal cycles, a gap may be created between the sealing material 19 and the cable 6 or the end plate 12, resulting in insufficient sealing effect. was there. To prevent this, it is possible to match the diameter of the cable insertion hole 14 of the end plate 12 with the outer diameter of the cable 6 as much as possible, and to increase the tightening force of the wrapping band 18. If bending stress is applied to the cable 6, the cable 6 may be damaged at the edge of the cable insertion hole 14 of the end plate 12.

Furthermore, since there are various outer diameters of the cable 6, conventionally, the cable insertion hole 14 of the end plate 12 has been drilled at the site according to the outer diameter. There were problems such as the need to replace the end plate 12.

Means for Solving the Problems> The present invention has been made in view of the above circumstances, and it improves the sealing effect in the cable insertion portion of the end plate compared to the conventional one, and This makes it possible to easily adapt to various types of objects without changing the size of the end plate.

Therefore, the present invention has a cylindrical plastic connection case, and each of the longitudinal ends of the connection case is provided with a plastic end plate that seals the opening of the connection case. A cable connection structure in which cables are inserted from the outside to the inside of the connection case with each end plate as a boundary and both cables are connected to each other inside the connection case has the following configuration.

That is, in the cable connection structure of the present invention, a through hole is formed in the end plate, a bushing made of an elastic material such as rubber is fitted into the through hole, and the bushing is located at least on the inner wall side of the end plate. A flange portion extending outward along the inner wall surface is formed in the portion.

<Function> In the above configuration, since the bushing made of an elastic material such as rubber is fitted into the through hole formed in the end plate, even if the end plate undergoes thermal cycles and repeatedly expands and contracts, this Since expansion and contraction are absorbed by the elastic force of the bushing, no gap is created between the sealing material and the cable or end plate, and the Knoll effect is sufficiently maintained over a long period of time.

In addition, since the bushing has a flange formed in the part located on the inner wall side of the end plate, for example, in the case of a type in which a detection gas is flowed inside the connection case to detect airtightness, The flange portion of the bushing is pressed against the end plate by the pressure of the internal gas, creating a self-sealing effect and further improving airtightness.

Furthermore, even for cables with different outside diameters, the size of the through hole in the end plate can be the same, and all you need to do is prepare bushings with different sizes of cable insertion holes. You can easily adapt to different things.

<Example> Fig. 1 is a sectional view of the end surface of the connection case of a cable connection structure according to an embodiment of the present invention, Fig. 2 is a perspective view showing a state in which a bushing is attached to the cable, and Fig. 3 and Fig. Components corresponding to the conventional example shown in FIG. 4 are given the same reference numerals.

The feature of this embodiment is that a through hole 20 having a diameter sufficiently larger than the outer diameter of the cable 6 is formed in the end plate 12, and a bushing 22 made of an elastic material such as rubber is fitted into the through hole 20. ing. This bushing 22 has a cable insertion hole 24 in the center, flanges 26 and 28 at both ends, and a slit cut from the outer wall of the bushing 22 to the cable insertion hole 24. 30 is coated at one location along the axial direction. The rest of the configuration is the same as that of the conventional example shown in FIG.

The hardness of the above bushing 22 is D40~
About 70 is preferable. The reason for this is that if the flange portion 26 is softer than this, it will easily deform due to external pressure.
．． If the effect of providing 28 is insufficient, and if it is too hard,
This is because it does not deform even when external pressure is applied, so the sealing effect becomes insufficient when subjected to thermal cycles. Also,
The provision of the slit 30 facilitates the work of inserting the cable 6, and also ensures that the bushing 22 is tightened along the circumferential direction and sufficiently adheres to the cable 6 even if there is some variation in the outer diameter of the cable 6. This is to ensure that.

In order to assemble the bushing 22 and end plate 12 to the cable 6, a tape-shaped clay sealant 19 is wrapped around a predetermined location of the cable 6 where the end plate 12 and bushing 22 are attached, and then the bushing 22 is attached. After the bushing 22 is fitted onto the outside and the outer periphery of the bushing 22 is temporarily secured with a band wire or the like, a similar tape-shaped sealing material 19 is wrapped around the outer periphery of the bushing 22. On the other hand, a similar sealing material is attached to the opposing surfaces of the abutting members 15.16 that constitute the end plate I2, and then both abutting members 15.16 are abutted against each other from above the bushing 22, and both 15.16 are integrated with the wrapping band 18. to be concluded. The following procedure is the same as in the conventional example.

In the above configuration, the through hole 20 formed in the end plate 12
Since the bushing 22 made of an elastic material such as rubber is fitted to the bushing 22, even if the end plate 12 repeatedly expands and contracts due to thermal cycles, this expansion and contraction will be prevented by the bushing 2.
It is absorbed by the elastic force of 2. Therefore, cable 6
and bushing 22, or between bushing 22 and end plate 1.
2, and the sealing effect is sufficiently maintained over a long period of time.

Additionally, flange portions 26 are provided at both ends of the bushing 22.
．． For example, in a system in which a detection gas is flowed inside the connection case 1 to detect airtightness, the pressure of the internal gas causes the flange portion of the bushing 22 on the inside side of the connection case 1 to 28 is pressed against the end plate 12, a self-sealing effect occurs and the airtightness is further improved. Conversely, when external pressure is applied, the other flange portion 26 is pressed against the end plate 12, producing a sealing effect.

Furthermore, for cables 6 with different outer diameters, it is sufficient to prepare in advance several types of cable insertion holes 24 of bushings 22 with different diameters.
Since the diameter of the through hole 20 of the end plate 12 may be made to match the outer diameter of the bushing 22, the shape of the end plate 12 may be constant.

<Effects of the Invention> According to the present invention, the sealing effect at the cable insertion portion of the end plate is enhanced compared to the conventional case, and it can be easily applied to cables with different outer diameters without changing the size of the end plate. It is possible to respond to various situations, and exhibits excellent effects such as cost reduction.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, with FIG. 1 being a cross-sectional view of the end surface of the connection case of the cable connection structure, and FIG. 2 being a perspective view showing a state in which a bushing is attached to the cable. 3 and 4 show a conventional example, with FIG. 3 being an exploded perspective view showing the entire cable connection structure, and FIG. 4 being a sectional view of the end face portion of the connection case of the cable connection structure. l Connection case, 2...opening/closing slit, 6...cable,! 2 end plate, 19 sole material, 20 through hole, 22 bushing, 26.28 flange portion.

Claims (1)

[Claims] (1) Has a cylindrical plastic connection case,
Plastic end plates that seal the openings of the connection case are provided at both ends of the connection case in the longitudinal direction, and cables are inserted from the outside of the connection case into the inside of the connection case using each end plate as a boundary. In a cable connection structure in which both cables are connected to each other inside a connection case, a through hole is formed in the end plate, a bushing made of an elastic material such as rubber is fitted into the through hole, and the bushing A cable connection structure characterized in that at least a portion of the end plate located on the inner wall side is formed with a flange portion projecting outward along the inner wall surface.