JP3869229B2 - Cable connection between water-proof and non-water-proof cables - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection part of a cable in which one cable to be connected has a water-impervious structure and the other has a non-water-impervious structure, and relates to a plug-in type or a room temperature shrink type connection part using an insulating cylinder Is.
[0002]
[Prior art]
The non-water-impervious cable having a non-water-impervious structure and the water-impervious cable having a water-impervious structure may be connected using an insulating cylinder.
[0003]
FIG. 6 and FIG. 7 are perspective views of portions where the non-water shielding cable 20a and the water shielding cable 20b are stripped. 6 and 7, 21a and 21b are cable conductors, 22a and 22b are cable inner semiconductive layers, 23a and 23b are cable insulating layers, 24a and 24b are cable outer semiconductive layers, 25a and 25b are shielding copper tapes, Reference numerals 26a and 26b denote cable sheaths. Reference numeral 27 denotes a water shielding layer.
[0004]
In the water-impervious cable 20b, the cable insulating layer 23b is unlikely to absorb moisture. Therefore, the insulation design is strict and the thickness of the cable insulating layer 23b is thinner than the thickness of the cable insulating layer 23a of the non-water-impervious cable 20a. is doing.
[0005]
FIG. 8 is a longitudinal sectional view of an insulating cylinder used for the connection. As shown in FIG. 8, the insulating cylinder 31 has an outer semiconductive layer 32 made of semiconductive rubber outside an insulating layer 33 made of insulating rubber, and an inner semiconductive layer 34 made of semiconductive rubber inside. It is expanded and held by a cylindrical expanded diameter holding member 35. The inner diameter of the insulating cylinder 31 is formed smaller than the outer diameter of the cable insulating layer of the cable to be connected, but is held by the diameter-expanding holding member 35 so as to be larger than the outer diameter of the cable insulating layer.
[0006]
As shown in FIG. 9A, the expanded diameter holding member 35 is formed by spirally winding a belt-like object 37 made of plastic. As shown in FIG. 9B, the belt-like object 37 is provided with concave and convex portions 37a and 37b in the longitudinal direction on the opposing surfaces of both side ends, and as shown in FIG. 9C, the concave and convex portions 37a and 37b, 37b is fitted and it is wound spirally.
[0007]
In forming the cable connecting portion, the insulating tube 31 whose diameter has been expanded by the diameter-enlargement holding member 35 is inserted in advance onto one cable sheath 26a (or 26b) before connecting the cable conductors 21a and 21b. In addition, after the cable conductors 21a and 21b are connected, the insulating cylinder 31 is returned to the conductor connection portion. Then, by pulling out the extraction member 36 on one end side of the enlarged diameter holding member 35 and pulling out the enlarged diameter holding member 35, the insulating cylinder 31 is mounted so as to be in close contact with the cable insulating layers 23a and 23b by the self-shrinking force. .
[0008]
[Problems to be solved by the invention]
By the way, the non-water-impervious cable 20a has a cable sheath 26a made of plastic, and cannot completely prevent the passage of moisture as in the case of a metal layer. Therefore, in the non-water-impervious cable 20a that has been subjected to long-term water immersion or the like, moisture that has passed through the cable sheath 26a reaches the shielded copper tape 25a and the cable conductor 21a. This moisture passes through the connecting portion in the axial direction and reaches the other cable of the connecting portion.
[0009]
If the other cable of the connecting portion is the water shielding cable 20b, the water shielding cable 20b itself has a water shielding structure, so that moisture does not enter from the outside. However, the water enters from the non-water-impervious cable 20a through the connecting portion. For this reason, the water shielding cable 20b which is designed to be insulated on the assumption that it is water-insulated is susceptible to insulation deterioration due to infiltrated moisture, and in the worst case, there is a problem of dielectric breakdown.
[0010]
Further, when the band-shaped object 37 that expands and holds the insulating cylinder 31 is spirally wound to form the diameter expansion holding member 35, depending on the difference in size of the concave and convex portions 37a and 37b or the degree of their fitting, FIG. As shown in c), a step 38 may occur in the fitting portion at the side end of the diameter-enlargement holding member 35. When the enlarged diameter holding member 35 is mounted in the insulating cylinder 31, the step 38 is transferred to the inner surface of the insulating cylinder 31 (made of a rubber elastic body), and the inner surface of the insulating cylinder 31 may be uneven.
[0011]
For this reason, when the insulating cylinder 31 expanded in diameter by the diameter expansion holding member 35 is used for a cable connection portion, a void is formed between the inner surface of the insulating cylinder 31 and the surfaces of the cable insulating layers 23a and 23b. As a result, the electric field is concentrated and the electrical performance is degraded.
[0012]
Further, when the outer diameters of the cable insulation layer 23a of the non-water-impervious cable 20a to be connected and the cable insulation layer 23b of the water-impervious cable 20b are different, the insulating cylinder 31 is attached to the cable insulation layers 23a and 23b with equal pressure. In other words, there was a problem that the electrical performance of the cable on the side where the outer diameter was narrow was lowered.
[0013]
The present invention has been made in order to solve the above-described conventional problems, and its purpose is to stop the moisture at the connection portion even when moisture enters the non-water-impervious cable and connect at the connection portion. It is intended to prevent moisture from entering the waterproof cable, and to prevent damage to the waterproof cable due to the penetration of moisture. Another object is to prevent a gap from being formed between the insulating cylinder and the cable insulating layer. Still another object is to allow the insulating cylinder to be attached to the cable insulating layer with equal pressure even when the outer diameters of the cable insulating layers to be connected are different. As a result, it is possible to provide a cable connecting portion between a water-proof cable and a non-water-proof cable that does not deteriorate the electrical performance.
[0014]
[Means for Solving the Problems]
The present invention has been made to solve the above problems, and the invention according to claim 1 is characterized in that the cable conductors of a water-impervious cable having a water-impervious layer and a non-water-impervious cable not having a water-impervious layer are connected. In the cable connection part of the water-proof cable and the non-water-proof cable formed by compressing and connecting with a conductor connection pipe with a partition wall and attaching an insulating tube across the cable insulation layers of both the cables, the conductor connection pipe and the both cables A first waterproof means is provided across the cable insulation layer, a second waterproof means is provided across the cable sheath end of the non-waterproof cable and the cable outer semiconductive layer, and the insulation A third waterproof means is provided covering the tube and straddling the cable sheaths of the two cables.
[0015]
The invention described in claim 2 is characterized in that, in the invention described in claim 1, a flowable insulating substance is interposed between the inner surface of the insulating tube and the surface of the cable insulating layer.
[0016]
The invention according to claim 3 is the invention according to claim 1 or 2, wherein the outer diameters of the cable insulation layers of the two cables are different, and the cable insulation layer having a smaller outer diameter has an outer diameter. A spacer for aligning the outer diameter with the larger cable insulating layer is mounted.
[0017]
Furthermore, the invention according to claim 4 is the invention according to claim 1 or 2, wherein the outer diameters of the cable insulation layers of the two cables are different, and the insulation tube is different from the cable insulation layers of the two cables. It has an inner diameter part.
[0018]
According to invention of Claim 1, since the 1st waterproofing means was provided ranging over the cable insulation layer by the side of the non-water-proof cable connected with a conductor connection pipe, It is possible to prevent moisture from entering the impermeable cable through the cable conductor from the inside. In addition, the water | moisture content transmitted in the cable conductor is stopped by the partition provided in the conductor connection pipe | tube. In addition, since the second prevention means is provided across the cable sheath end of the non-water-impervious cable and the cable outer semiconductive layer, moisture from between the cable sheath of the non-water-impervious cable and the cable outer semi-conductive layer, For example, it can be prevented from entering the water shielding cable through the shielding copper tape. Furthermore, since the third waterproofing means is provided across the cable sheaths of the cables on both sides of the insulating cylinder, it is possible to prevent moisture from entering the impermeable cable from the outside of the connecting portion.
[0019]
According to the second aspect of the present invention, since the flowable insulating material is interposed between the inner surface of the insulating cylinder and the surface of the cable insulating layer, the inner surface of the insulating cylinder is not interposed via the insulating material. The water shielding cable and the cable insulation layer of the water shielding cable are attached without generating a gap, and the deterioration of the electrical insulation performance at the connection portion can be prevented. The insulating material is preferably a non-moisture permeable material equivalent to or better than the cable insulator.
[0020]
According to the invention described in claim 3, when the outer diameters of the cable insulation layers of the two cables are different, the insulation cylinder is closely attached to the cable insulation layer having a smaller outer diameter via the spacer. Therefore, even if the inner diameter of the insulating cylinder is uniform in the longitudinal direction, it is possible to prevent the electrical insulation performance from being deteriorated in the connection portion of the cable having the cable insulating layers having different outer diameters.
[0021]
Furthermore, according to the invention described in claim 4, when the outer diameters of the cable insulation layers of both cables are different, the insulation cylinder has different inner diameter portions that are in close contact with the cable insulation layers of both cables. Even if the outer diameters of the cable insulation layers of the cables are different, it is possible to prevent a decrease in the electrical insulation performance at the connection portion.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0023]
FIG. 1 is a partial vertical cross-sectional view of an embodiment of a cable connecting portion between a water-proof cable and a non-water-proof cable according to the present invention. In FIG. 1, the same parts as those described with reference to FIGS. 6 and 7 are designated by the same reference numerals. Reference numeral 7 denotes an external semiconductive layer processing section.
[0024]
As shown in FIG. 1, in this embodiment, the exposed cable conductors 21a and 21b of the non-water-proof cable 20a and the water-proof cable 20b are compression-connected to each other by the conductor connection pipe 1 with the partition wall 1a. Further, the surfaces of the cable insulation layer 23 a of the non-water-impervious cable 20 a and the cable insulation layer 23 b of the water-impervious cable 20 b are covered with an insulating cylinder 31.
[0025]
What is different from the conventional example in this embodiment is that the following waterproofing means is taken.
[0026]
First, as the first waterproofing means, the adhesive watertight tape 2 is tightly wound over the end of the conductor connecting pipe 1 connecting the cable conductors 21a and 21b and the end of the cable insulating layers 23a and 23b. That is.
[0027]
Further, as the second waterproofing means, the adhesive watertight sheet 4 is wound over the surface of the cable outer semiconductive layer 24a on the non-waterproof cable 20a side and the end of the cable sheath 26a.
[0028]
The grounding conductor for grounding the shielding copper tape 25a on the non-water-shielding cable 20a side is not shown, but after being connected to the shielding copper tape 25a, an adhesive watertight sheet is wound around it and pulled out of the sheath 26a. Thus, water tightness around the ground conductor can be ensured. In FIG. 1, reference numeral 28 denotes a metal shielding connection line that connects the shielding copper tape 25 a on the non-water shielding cable 20 a side and the shielding copper tape 25 b on the water shielding cable 20 b side.
[0029]
Further, as a third waterproofing means, the surface of the insulating cylinder 31 is straddled over the cable sheaths 26a and 26b of the non-water-proof cable 20a and the water-proof cable 20b, covered with the water-proof shrinkable tube 5, and That is, the waterproof tape 6 is wound around the part and the sheaths 26a and 26b. In addition, the adhesive watertight sheet 3 is wound over the end portion (external semiconductive layer 32) of the insulating cylinder 31 and the cable external semiconductive layers 24a and 24b.
[0030]
According to the present embodiment, even if moisture enters the cable conductor 21a of the non-waterproof cable 20a by the first waterproofing means, the moisture is blocked by the adhesive watertight tape 2 and the water shielded cable 20b side. It is not transmitted to.
[0031]
Moreover, even if moisture enters the shielding copper tape 25a between the cable outer semiconductive layer 24a and the cable sheath 26a of the non-waterproof cable 20a by the second waterproofing means, this moisture will enter the adhesive watertight sheet 4. It is blocked and does not enter the connection side.
[0032]
Furthermore, by the third waterproofing means, moisture from the outside of the connecting portion is blocked by the water shielding shrinkable tube 5 and the waterproof tape 6 and does not enter the connecting portion.
[0033]
In the present embodiment, as shown in FIGS. 2A and 2B, the insulating cylinder 31 is coated with a flowable insulating material 41 such as silicone grease, fluorine grease, silicone oil, fluorine oil, or the like on the inner surface. The expanded diameter holding member 35 is inserted in the state, and the diameter is expanded larger than the outer diameter of the cable insulating layers 23a and 23b. Therefore, the non-adhesive flowable insulating material 41 is interposed between the inner surface of the insulating cylinder 31 and the enlarged diameter holding member 35, and the step 38 of the enlarged diameter holding member 35 is clogged with the inner surface of the insulating cylinder 31. However, the flowable insulating material 41 and the insulating cylinder 31 are brought into close contact with each other by the flow of the flowable insulating material 41 after forming the cable connection portion, and no gap is generated at the interface between them.
[0034]
When the diameter-enlarged holding member 35 is pulled out and the insulation cylinder 31 is mounted on the cable insulation layers 23a and 23b, the insulation cylinder 31 comes into close contact with the cable insulation layers 23a and 23b without generating a gap. Is attached.
[0035]
The insulating cylinder 31 is not limited to the above embodiment. FIG. 3 is a vertical cross-sectional view of a main part of the insulating cylinder 31 used when the outer diameters of the cable insulating layers 23a and 23b of the non-water-proof cable 20a and the water-proof cable 20b to be connected are different. In FIG. 3, a cylindrical spacer 42 is provided on the inner surface of the insulating cylinder 31 on the side where the small-diameter cable insulating layer is inserted. The inner diameter on the large diameter side and the inner diameter on the small diameter side of the insulating cylinder 31 are set so that a substantially uniform interface pressure can be obtained when they are attached to cable insulation layers having different outer diameters. Reference numeral 33 denotes an insulating layer, 34 denotes an internal semiconductive layer, and 36 denotes an extraction member. The spacer 42 includes an insulating portion 42a and a semiconductive portion 42b.
[0036]
Further, two diameter expansion holding members 35 having different outer diameters are inserted from both sides of the insulating cylinder 31 in accordance with the difference in inner diameter between the insulating cylinder 31 and the spacer 42.
[0037]
The spacers 42 may be provided on both sides of the insulating cylinder 31 to form a desired inner diameter, and the diameter-enlarged holding member 35 may be a single member having portions having different outer diameters.
[0038]
FIG. 4 is a longitudinal sectional view of an essential part of another embodiment when the outer diameters of the cable insulating layers to be connected are different. In FIG. 4, 43 is a small-diameter cable insulation layer, and 44 is a large-diameter cable insulation layer. The inner diameter of the insulating cylinder 31 is uniform in the longitudinal direction, and a spacer 45 is covered on the small-diameter cable insulating layer 43. The outer diameter of the spacer 45 is set so that when the insulating cylinder 31 is attached to the cable insulating layers 43 and 44 having different outer diameters, a substantially uniform interface pressure is obtained in both. The spacer 45 includes an insulating portion 45a and a semiconductive portion 45b, and the external semiconductive layer 32 of the insulating tube 31 and the cable external semiconductive layer 24 are electrically connected by the semiconductive portion 45b. In this portion, as shown in FIG. 1, an external semiconductive layer processing section 7 may be provided.
[0039]
In forming this connection portion, before connecting the cable conductors 46 and 47, the spacer 45 is put on the end of the cable insulating layer 43 in advance, and then the cable conductors 46 and 47 are connected. Then, the insulating cylinder 31 inserted in advance on the cable insulating layer 43 is returned to the conductor connecting portion.
[0040]
FIG. 5 is a longitudinal sectional view of a main part of another embodiment of the insulating cylinder 31 used when the outer diameters of the cable insulating layers to be connected are different. In FIG. 5, the inner diameter of the insulating cylinder 31 is different on both sides of the central portion in the length direction, and the inner diameter is required for each cable when it is attached to a cable insulating layer having a different outer diameter. It is set so that an interface pressure exceeding a predetermined value can be obtained.
[0041]
In the above example, the flowable insulating material is applied to the inner surface of the insulating tube in advance, and the flowable insulating material is interposed between the surfaces of the insulating tube and the cable insulating layer. Instead of applying a flowable insulating material, instead of applying a flowable insulating material to the surface of the cable insulation layer, the flowable insulation material is interposed between the surface of the insulation cylinder and the cable insulation layer. You can also.
[0042]
【The invention's effect】
As described above, according to the first aspect of the present invention, the first, second, and third waterproofing means are provided at different positions in the connection portion. There is an excellent effect that intrusion can be prevented.
[0043]
In the invention according to claim 2, since the flowable insulating material is interposed between the inner surface of the insulating cylinder and the surface of the cable insulating layer, it is possible to prevent the deterioration of the insulating performance in the connection portion. effective.
[0044]
In the inventions according to claims 3 and 4, when the outer diameters of the cable insulation layers of the non-waterproof cable and the watertight cable to be connected are different, the cable insulation layer having a smaller outer diameter has an outer diameter of A spacer is installed to align the outer diameter with the larger cable insulation layer, or the insulation cylinder is attached, or the insulation cylinder has a different inner diameter that is in close contact with the cable insulation layer of both cables, so it is connected Even if the outer diameters of the cable insulation layers of the non-water-proof cable and the water-proof cable are different, there is an excellent effect that the deterioration of the insulation performance can be prevented.
[Brief description of the drawings]
FIG. 1 is a partial longitudinal sectional view of an embodiment of a cable connecting portion between a water-proof cable and a non-water-proof cable according to the present invention.
FIGS. 2A and 2B are a partial sectional view of an insulating cylinder used in the embodiment and an enlarged view of a portion A in FIG.
FIG. 3 is a longitudinal sectional view of another embodiment of an insulating cylinder.
FIG. 4 is a longitudinal sectional view of still another embodiment of an insulating cylinder.
FIG. 5 is a longitudinal sectional view of still another embodiment of an insulating cylinder.
FIG. 6 is a perspective view of a part of the non-water-shielding cable that has been stripped.
FIG. 7 is a perspective view of a stepped portion of the water shielding cable.
FIG. 8 is a longitudinal sectional view of a conventional insulating cylinder.
FIGS. 9A to 9C are a side view of an enlarged diameter holding member, a cross-sectional view of a belt-shaped object constituting the enlarged diameter holding member, and an enlarged view of a portion A in FIG. 9A, respectively.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Conductor connection pipe 1a Bulkhead 2 Adhesive watertight tape 3, 4 Adhesive watertight sheet 5 Water shielding shrinkable tube 6 Waterproof tape 7 External semiconductive layer processing part 20a Non-water shielding cable 20b Water shielding cables 21a, 21b, 46, 47 Cable conductor 23a , 23b, 43, 44 Cable insulation layers 24, 24a, 24b Cable outer semiconductive layers 25a, 25b Shielding copper tape 26a, 26b Cable sheath 27 Water shielding layer 28 Metal shielding connection line 31 Insulating cylinder 32 External semiconductive layer 33 Insulating layer 34 Internal semiconductive layer 35 Expanded diameter holding member 36 Extraction member 37 Strips 37a, 37b Uneven portion 41 Flowable insulating material 42, 45 Spacers 42a, 45a Insulating portions 42b, 45b Semiconductive portion

Claims (4)

The cable conductors of the impermeable cable having the impermeable layer and the non-impermeable cable not having the impermeable layer are compressed and connected with the conductor connecting pipe with the partition wall, and the insulating cylinder is straddled between the cable insulating layers of the two cables. In the cable connection part of the impermeable cable and the non-impermeable cable,
A first waterproofing means is provided across the conductor connecting pipe and the cable insulation layers of the two cables, and a second waterproofing is provided across the cable sheath end of the non-waterproof cable and the cable outer semiconductive layer. A cable connecting portion for a water-proof cable and a non-water-proof cable, characterized in that a third waterproof means is provided across the cable sheath of the two cables. The cable connection part of the water-impervious cable and the non-water-impervious cable according to claim 1, wherein a flowable insulating material is interposed between an inner surface of the insulating tube and a surface of the cable insulating layer. The outer diameters of the cable insulation layers of the two cables are different, and the cable insulation layer having the smaller outer diameter is equipped with a spacer for aligning the outer diameter with the cable insulation layer having the larger outer diameter. The cable connection part of the impermeable cable and non-impermeable cable of Claim 1 or 2 characterized by the above-mentioned. The water shielding layer according to claim 1 or 2, wherein the outer diameters of the cable insulation layers of the two cables are different, and the insulation cylinder has different inner diameter portions that are in close contact with the cable insulation layers of the two cables. Cable connection between cable and non-waterproof cable.

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