JP2001211522A - Widening jig of rubber unit for connecting electric power cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily insert an electrical cable without imparting a forcible deformation to a rubber unit and prevent enlargement of the connecting part. SOLUTION: The widening jig 1 for the rubber unit 2 used when inserting an electrical cable 6 into a cylindrical rubber unit 2 having a plug-in-contact type conductor pipe 3 is formed of a split cylindrical body 1a that a plurality of split pieces are cylindrically combined together so as to disassemble and remove the rubber unit 2 by longitudinally dividing it. At least the intermediate part 1B is tapered off from the rear end part 1C to the front end part 1A and the inside diameter of the front end part 1A is set small in such an extent, that the split cylindrical body 1a can move on an insulating material 11. The inside diameter of the rear end part 1C is set large at least in such an extent that the split cylindrical body 1a can move on a cable sheath 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for expanding a rubber unit for connecting a power cable to a rubber or plastic insulated power cable (hereinafter referred to as a power cable).

[0002]

2. Description of the Related Art In recent years, for the purpose of simplifying and shortening the connection work of power cables and improving workability, the outer periphery of a plug-in contact type conductor connection pipe is mainly made of, for example, a silicone rubber material. A one-piece cylindrical rubber unit formed integrally with a reinforcing insulating layer having an inner and an outer semiconductive layer is used as a reinforcing insulating member of a power cable connection portion. And this rubber unit
Due to the contraction force of the cable itself, surface pressure is applied to the interface between the power cable and the cable insulator, so that the inner diameter of the portion in contact with the cable insulator is outside the cable insulator so that good electrical insulation characteristics can be obtained. It is formed smaller than the diameter.

[0003] Therefore, in order to form a connection portion of the power cable, it is necessary to insert the power cable into the rubber unit. For this purpose, the following two methods have been used. The first method is a manual method. A second method is to tie a nylon string (nylon string) to the power cable and the rubber unit, or hold them with cleats, attach a chain block between the nylon strings or cleats, and activate the strings or the strings. In this method, the distance between the cleats is gradually reduced, and the power cable is inserted. Further, when inserting the power cable into the rubber unit, a method is conceivable in which the rubber unit is previously expanded to a diameter larger than the outer diameter of the cable insulator with a diameter expanding jig.

[0004]

However, the first manual method has the disadvantage that the insertion of the power cable requires a great deal of effort and is troublesome. In the method using the second nylon string or cleat, a large compressive force is applied to the portion of the power cable to which the nylon string or cleat is attached, and the power cable or rubber unit may be crushed and deformed, resulting in poor connection. there were.

[0005] Further, the method using the diameter-expanding jig can be considered in a case where the inner diameter of the diameter-expanding jig is larger or smaller than the outer diameter of the cable sheath. In the former case, the inner diameter of the rubber unit is generally considerably increased, and the deformation of the reinforcing insulating layer at the tip end of the diameter increasing jig increases. However,
Since the reinforcing insulating layer of the rubber unit and the internal conductor connection tube are bonded and fixed so as not to be easily peeled off, the reinforcing insulating layer near the bonded portion is hardly deformed. Therefore, when the inner diameter of the rubber unit is greatly increased, a crack is generated in a part of the reinforcing insulating layer (near the end of the enlarged diameter jig), and there is a great risk that the connection portion may cause electrical breakdown. In the latter case, the diameter difference between the inner diameter of the expanding jig and the inner diameter of the rubber unit before expansion is relatively small, and when the expanding jig is inserted into the rubber unit, the inner diameter of the jig near the tip end is reduced. Since the amount of deformation of the reinforced insulating layer is small, the risk of cracks occurring in the reinforced insulating layer as described above is reduced. However, in the latter case, the inner diameter of the diameter expansion jig is smaller than the outer diameter of the cable sheath.
If you try to pull out the expanding jig from this after inserting the power cable, the rear end of the jig will be caught by the step of the cable sheath and will not be pulled out, so the cable sheath will be long enough to pull out the expanding jig. Need to be removed. Normally, the total length of the diameter-enlargement jig is about 250 mm in consideration of workability, so the interval between the end of the rubber unit and the removed end of the cable sheath needs to be at least 250 mm.
In the conventional method using human power, the distance is 100 mm.
The length of the end portion of the connection portion is 150
There is a problem that mm also becomes longer.

The present invention has been made in view of the above, and it is possible to insert a power cable into a rubber unit without any labor or effort, and to make excessive deformation of the cable or the reinforcing insulating layer of the rubber unit. An object of the present invention is to provide a power cable connecting rubber unit expansion jig which does not cause damage to the cable unit and can prevent an increase in the length of the cable sheath removal and prevent the connection portion from being enlarged.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a cylindrical rubber formed by integrally molding a reinforcing insulating layer made of rubber on the outer periphery of a conductor connection tube of a plug-in contact type. When the power cable is inserted into the unit and the connection plug attached to the conductor end is inserted into the conductor connection tube of the rubber unit, the power that expands the inner diameter of the rubber unit larger than the outer diameter of the cable insulator In the diameter expansion jig of the rubber unit for cable connection, so as to be disassembled and removed in the vertical direction along the longitudinal axis of the rubber unit,
It is formed of a divided cylindrical body in which a plurality of divided pieces are combined in a cylindrical shape, at least an intermediate portion of which is tapered from the rear end side to the front end side, and the inner diameter of the front end is the divided cylindrical body. The configuration is characterized in that the body is set small enough to move on the cable insulator, and the inside diameter of the rear end is set large enough to allow the split cylindrical body to move at least over the cable sheath. It has become.

In the power cable connecting rubber unit expanding jig according to the present invention, as described above, at least the intermediate portion of the split cylindrical member is tapered from the rear end toward the front end. Since the inner diameter of the tip is set small enough to allow the split cylindrical body to move on the cable insulator, the rubber unit is gradually expanded, and without being greatly expanded, In particular, there is no danger of cracks occurring in the reinforcing insulating layer near the conductor connection pipe, and there is no danger that the power cable connection will cause electrical breakdown. Also, since the inner diameter of the rear end of the diameter-enlargement jig is set so large that the split-type cylindrical body can move at least over the cable sheath, after the rubber unit diameter-expansion and power cable insertion work are completed. When the diameter-expanding jig is pulled out from the rubber unit, the rear end of the diameter-expanding jig does not catch on the step of the cable sheath, and the diameter-expanding jig can be easily pulled out. Therefore, it is not necessary to remove the cable sheath by a length enough to pull out the diameter increasing jig, and it is possible to suppress an increase in the length of the connection portion. Furthermore, this expanding jig is
Since it is formed of a divided cylindrical body, it can be easily disassembled and removed after being pulled out of the rubber unit.

[0009]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described in more detail in 2. The power cable connecting rubber unit expansion jig 1 according to the present invention is a cylindrical rubber unit 2 used as a reinforcing insulating member of a power cable connecting portion.
When the cable is connected by inserting a power cable into the rubber unit 2, the rubber unit 2 is used to expand the diameter. Rubber unit 2
Is a one-piece cylindrical body formed by integrally molding, for example, a reinforcing insulating layer 4 having an inner and an outer semiconductive layer mainly composed of a silicone rubber material on the outer periphery of a conductor connection tube 3 of a plug-in contact type. It consists of. The inner diameter of the portion of the power cable 6 that contacts the cable insulator 11 is set smaller than the outer diameter of the cable insulator 11 so that a surface pressure is applied to the interface with the cable insulator 11. Therefore, it is necessary to increase the diameter of the rubber unit 2 in order to easily insert the power cable 6 into the rubber unit 2.

After the expansion of the rubber unit 2 and the insertion of the power cable 6 are completed, the diameter expanding jig 1 of the present invention is pulled out of the rubber unit 2 so that the jig 1 extends vertically along the longitudinal axis of the rubber unit 2. As shown in FIGS. 2 (a), 2 (b) and 2 (c), a split-type cylindrical shape obtained by combining two semi-cylindrical split pieces 1b and 1c into a cylindrical shape so that they can be disassembled and removed. The body 1a is formed. Although not shown, three or more divided pieces may be combined in a cylindrical shape so that the divided cylindrical body 1a can be divided into three or more.

The intermediate portion 1B of the split cylindrical body 1a has an inner and outer surface tapered from the rear end 1C to the front end 1A, for example, in a tapered (truncated cylindrical) shape. The front end 1A and the rear end 1C are straight cylinders having the same inner and outer diameters in the longitudinal direction and having inner and outer surfaces parallel to each other. The inner diameter of the distal end portion 1A is set so small that the diameter-expanding jig 1 can move on the cable insulator 11 of the power cable 6, and the gap between the inner surface of the distal end portion 1A and the outer surface of the cable insulator 11 is reduced. It is designed to be as small as possible. The inner diameter of the rear end 1C is set to be large enough to allow the diameter-expanding jig 1 to move at least on the cable sheath 7. Therefore, when nothing is provided on the cable sheath 7, the inner diameter of the rear end 1 </ b> C may be set to a size slightly larger than the outer diameter of the cable sheath 7. FIG.
As shown in (1), when the shield wire 8a of the shield layer 8 is provided on the cable sheath 7 by folding back to the sheath side, the expanding jig 1 is placed on the shield wire 8a (outside). It needs to be set to a size that can move more. Of course, even when nothing is provided on the cable sheath 7, the shield wire 8
It may be set to be larger than the inner diameter required when a is folded back. However, if the inner diameter of the rear end portion 1C is increased more than necessary, the diameter increasing jig becomes large,
It is not preferable because handling becomes inconvenient. Further, a circular flange 1d is provided at the rearmost end of the rear end 1C as a handle for facilitating the operation of inserting the jig 1 into the rubber unit 2 and pulling it out of the rubber unit 2. .

Reference numeral 5 denotes a semi-cylindrical divided piece 1b, 1c.
Is an L-shaped fastening piece, for example, which is connected and fixed so that the split-type cylindrical body 1a obtained by combining the two pieces into a cylindrical shape is not easily disassembled (disassembled) into the individual pieces 1b, 1c. The fastening piece 5 is arranged so as to straddle the outer peripheral surface near each of the divided surfaces of the divided pieces 1b and 1c facing 180 degrees, and to be in contact with the front side surface of the circular flange 1d. It is provided detachably by screwing. The material of the diameter-expanding jig 1 may be anything as long as it has a rigidity capable of expanding the diameter of the rubber unit 2, such as a steel material such as mild steel, carbon steel, or SUS steel, or a non-ferrous material such as copper, aluminum, or an alloy thereof. A metal material and a plastic material such as FRP are preferable.

Next, a method of using the diameter expanding jig 1 of the present invention will be described with reference to FIG. First, as a preparation for inserting the power cable 6 into the rubber unit 2 for expanding the diameter, at the end of the power cable 6, the shield layer 8, the intervening layer 9, the external semiconductive layer 10, The cable insulator 11 and the conductor end 12 are stripped off and exposed. Next, a shield layer 8 is formed on the cable sheath 7.
Of the conductor end portion 12a is folded back and provided.
An operation of mounting a connection plug 13 made of a highly conductive metal material such as copper is performed.

Next, the distal end 1A and the intermediate portion 1B of the diameter-expanding jig 1 are gradually inserted from the distal end 1A into the cable insertion hole 2a of the rubber unit 2 on the side where the power cable 6 is inserted. 2 is expanded in diameter. Next, the rubber unit 2
After the diameter expansion work is completed, the power cable 6 is inserted through the diameter expansion jig 1 into the cable insertion hole 2a of the rubber unit 2,
The connection plug 13 attached to the conductor end 12 of the power cable 6 is inserted into the conductor connection pipe 3 of the rubber unit 2. After that, the expanding jig 1 is connected to the cable insertion hole 2a of the rubber unit 2.
, The two fastening pieces 5 of the diameter-expanding jig 1 are removed, and the divided pieces 1b and 1c of the diameter-expanding jig 1 are vertically divided into two along the longitudinal axis of the rubber unit 2. Dismantle and remove.

In addition to the diameter expanding jig 1 shown in FIGS. 1 and 2, the diameter expanding jigs 14 and 1 shown in FIGS.
5, 16 or the like may be used. That is, in the diameter increasing jig 14 shown in FIG. 3, the intermediate portion 14B and the rear end portion 14C have the rear end portion 14C.
This is an example in which, for example, a tapered shape is tapered from the side toward the distal end portion 14A, and only the distal end portion 14A is a straight cylindrical body having the same inner diameter in the longitudinal direction and having parallel inner and outer surfaces. The diameter expanding jig 15 shown in FIG.
B has a tapered shape, for example, tapered from the rear end portion 15C side to the front end portion 15A side, and only the rear end portion 15C is a straight cylindrical body having the same inner diameter in the longitudinal direction and having parallel inner and outer surfaces. It is an example. Further, in the diameter expanding jig 16 shown in FIG. 5, the entire front end portion 16A, the intermediate portion 16B, and the rear end portion 16C have, for example, a tapered shape tapered from the rear end portion 16C side to the front end portion 16A side. It is an example.

[0016]

According to the present invention, as described above, the power cable is connected to the cylindrical rubber unit obtained by integrally molding the rubber reinforcing insulating layer on the outer periphery of the plug-in contact type conductor connection tube. When inserting and inserting the connection plug attached to the conductor end into the conductor connection pipe of the rubber unit, the rubber unit for the power cable connection unit that expands the inner diameter of the rubber unit larger than the outer diameter of the cable insulator In the diameter-enlargement jig, the rubber unit is formed of a divided cylindrical body in which a plurality of divided pieces are combined in a cylindrical shape so that the rubber unit can be disassembled and removed in the longitudinal direction along the longitudinal axis of the rubber unit. The portion has a tapered shape from the rear end side to the front end side, and the inner diameter of the front end portion is set small enough to allow the split type tubular body to move on the cable insulator, and the inner diameter of the rear end portion is set. Has few split-type cylindrical bodies Since both set to be larger to the extent that can be moved over the cable sheath can be inserted without the labor and effort power cable into the rubber unit. In addition, when the diameter increasing jig having the above configuration is used, the rubber unit is gradually increased in diameter, and is not greatly increased. Eliminates the risk of electrical breakdown at cable connections. Also, since the inner diameter of the rear end of the diameter-enlargement jig is set so large that the split-type cylindrical body can move at least over the cable sheath, after the rubber unit diameter-expansion and power cable insertion work are completed. When the diameter-expanding jig is pulled out from the rubber unit, the rear end of the diameter-expanding jig does not catch on the step of the cable sheath, and the diameter-expanding jig can be easily pulled out. Therefore, it is not necessary to remove the cable sheath by a length enough to pull out the diameter increasing jig, and it is possible to suppress an increase in the length of the connection portion. Furthermore, since this diameter-expanding jig is formed of a divided cylindrical body, it can be easily disassembled and removed after being pulled out from the rubber unit.

[Brief description of the drawings]

FIG. 1 is a partially omitted upper half sectional view showing a use state of a diameter increasing jig of a rubber unit for power cable connection according to the present invention.

FIG. 2 is a view showing an outline of a diameter expanding jig of the present invention;
(A) is a front view of the upper half section, (b) is a plan view, (c)
Is a right side view.

FIG. 3 is an upper half sectional view showing a modified example of the diameter expanding jig of the present invention.

FIG. 4 is an upper half sectional view showing a modified example of the diameter expanding jig of the present invention different from that shown in FIG. 3;

FIG. 5 is an upper half sectional view showing a modification of the diameter expanding jig of the present invention which is different from those shown in FIGS.

[Explanation of symbols]

 1, 14, 15, 16 Diameter expanding jig 1a Divided cylindrical body 1b, 1c Divided piece 1d Circular flange 1A, 14A, 15A, 16A Tip 1B, 14B, 15B, 16B Intermediate 1C, 14C, 15C, 16C Rear end 2 Rubber unit 2a Cable insertion hole 3 Conductor connection tube 4 Reinforcement insulation layer 5 Fastening piece 6 Power cable 7 Cable sheath 8 Shield layer 8a Shield wire 9 Intervening layer 10 External semiconductive layer 11 Cable insulator 12 Conductor end Part 13 Connection plug

Claims (1)

[Claims] A power cable is inserted into a cylindrical rubber unit formed by integrally molding a rubber-made reinforcing insulating layer around the outer periphery of a plug-in contact type conductor connection tube, and is attached to the conductor end. When the connection plug is inserted into the conductor connection tube of the rubber unit, the inner diameter of the rubber unit is expanded larger than the outer diameter of the cable insulator. It is formed of a split-type cylindrical body in which a plurality of split pieces are combined into a cylindrical shape so that they can be disassembled and removed in the vertical direction along the axis of
At least the middle portion is tapered from the rear end toward the front end, and the inner diameter of the front end is set small enough to allow the split cylindrical body to move on the cable insulator. A jig for a rubber unit for connecting a power cable, wherein an inner diameter of the portion is set so large that the divided cylindrical body can move at least on the cable sheath.