JP2003052119A - Connection metal fitting for cable conductor, cable intermediate connection part and cable terminal connection part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for a cable connection part, displaying strong anchor force with respect to extracting force acting in a cable conductor, which can readily make connection furthermore quickly without complicated soldering works or particular tools and jigs required at connection work to the cable conductor. SOLUTION: This cable connection metal fitting, comprising an electrode conductor having an almost cylindrical part which has a tapered inner surface diametrically contracted toward the end part, a metal-made wedge fitted to the tapered inner surface to be formed in almost a conic cylindrical shape, and a spring pressing the wedge in the electrode conductor in the direction of the end part, is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductor connecting fitting for high-voltage / ultra-high-voltage cables, an intermediate connecting portion of a cable using the same, and a cable end connecting portion.

[0002]

2. Description of the Related Art High-pressure / ultra-high pressure cross-linked polyethylene (C
V) As a method of connecting the cable conductors at the intermediate connection portion and the terminal connection portion of the cable, a method of covering the conductor with a cylindrical sleeve for soldering, a method of covering the conductor with the cylindrical sleeve and fixing by pressure welding, Conventionally, a method of tightening with a wedge has been used.

FIG. 6 shows an example of an intermediate connecting portion in which conductors are connected by using a pressure contact sleeve. There is a pair of Cs in the intermediate connecting portion 3.
The V cable 1 is inserted and connected. In each CV cable 1, the outer sheath and the semiconductive layer are stripped off at the connecting portion, and the insulating layer 5 is stripped off to expose the stranded conductors 7a and 7b of the cable. The exposed pair of stranded conductors 7a and 7b are compression-connected by a sleeve 9. The sleeve 9 is made of copper and has a substantially cylindrical shape. In this example, a partition is provided near the center. The stranded conductors 7a and 7b are inserted from both sides of the sleeve 9, and the sleeve 9 is connected to each other by being compressed from the outer periphery by a pressure welding die. Sleeve 9 and stranded conductors 7a, 7b
An internal electrode 11 for adjusting the electric field distribution is provided in the periphery of the internal electrode 11, and the internal electrode 11 is electrically and mechanically connected to the sleeve 9. Insulation molded body 13 made of epoxy resin so as to surround the inner electrode 11 and the vicinity of the end of the cable 1.
Is provided and the rubber stress cone 17 is inserted between the insulating molded body 13 and the cable 1. The rubber stress cone 17 is composed of an insulating layer on the tip side and a semi-conductive layer on the root side, and is pressed in the insulating molded body 13 by a pressing mechanism 19 that is a combination of springs and screws. The insulating mold body 13 and the rubber stress cone 17 serve as an insulating reinforcing body that insulates the high voltage portion of the cable connecting portion. A metal case 15 is provided around the insulating mold body. Such an intermediate connecting portion is a known one, and an example of a sleeve used for this is an actual flat blade 5-1.
1327 and the like.

In connection with a cable conductor using a wedge stopper, a tapered opening is provided in the conductor metal portion of the cable connecting portion, and a conical tubular wedge is inserted with the cable conductor inserted therein, There are those that are tightened with the screws of the tightening metal fittings.
It is described in Japanese Patent Publication No. 1 and the like. Also, the actual public 63-48
Japanese Patent Publication No. 059 describes an improvement of such a wedge preventing mechanism suitable for application to a cable intermediate connecting portion.

[0005]

Among the above-mentioned connecting methods, the method using soldering has the advantage that good conductivity can be obtained, but the soldering work for connecting conductors is complicated and Since fire was used for the attachment work, there was a problem in the work in the underground cave and manhole. The method using the pressure welding sleeve is widely used at present in the intermediate connection part, but a special hydraulic compression device is required for the compression work of the sleeve, which requires a large amount of work. It has the disadvantage that it is easily displaced or bent. Although the work using the wedge is slightly easier than the above method, it requires a special tool for tightening and fixing the wedge. Further, since the wedge is tightened by screwing in the tightening metal fitting, there is a disadvantage that a metal facet is apt to be generated by the screw, which easily causes deterioration of insulation. The present invention solves these disadvantages of the conventional method, and provides a connecting portion of a cable conductor which enables reliable conductor connection with a simple connecting operation.

[0006]

[Means for Solving the Problems] A first means is to fit a connecting fitting for a cable conductor to an electrode conductor having a substantially cylindrical portion having a tapered inner surface whose diameter decreases toward an end, and to the tapered inner surface. It is to have a substantially wedge-shaped metal wedge that is inserted and a spring that presses the wedge toward the end in the electrode conductor (claim 1).

The above-mentioned connecting metal fitting is one in which the conductor of the cable end connected from the end thereof is inserted into the wedge and the conductor is fixed by the tightening force of the wedge. In the present invention, the substantially conical cylindrical wedge is pressed by the tapered inner surface inside the electrode conductor, and the force for tightening the cable conductor works to fix the conductor. When a pulling force acts on the cable conductor, a force more tightening the wedge acts, so that a high retaining force of the cable conductor and good electrical contact can be obtained. In addition, the cable conductor can be easily connected without the need for complicated work such as soldering or sleeve pressure welding.
It is easy to remove the conductor once connected.

A second means is that the connection fitting has a stopper member which is detachably attached to the end portion of the electrode conductor and which prevents the wedge from moving toward the end portion (claim 2).

By providing such a stopper member, the wedge can be held in an open state. The cable conductor can be easily connected by previously attaching the stopper member in the opened state by pushing in the wedge and removing the stopper member when connecting the conductor.

The third means relates to a cable intermediate connecting portion, and has a connecting fitting for connecting conductor ends of a pair of cables to be connected, and an insulating reinforcing body surrounding the connecting fitting and the cable end. Then, the connection fitting, an electrode conductor having a substantially cylindrical portion having a tapered inner surface that reduces in diameter toward both ends, and a metal wedge having a substantially conical tubular shape fitted into the tapered inner surface, And a spring for pressing the wedge in the electrode conductor toward both ends thereof.

As described above, in the conventional cable intermediate connection portion, the pressure contact by the sleeve is often used for the conductor connection, but there is a disadvantage that the center axis of the conductor is easily displaced during the pressure contact. If the center axis of the cable conductor is displaced at the cable intermediate connection portion, the contact surface pressure between the cable and the insulating reinforcing member becomes uneven, which is not preferable from the viewpoint of ensuring the insulation characteristic. On the other hand, in the present invention, since the conductors are connected by using the tightening action of the wedge, there is no possibility that the center is displaced like the pressure contact by the sleeve, good insulating characteristics can be obtained, and the connection work is easy.

A fourth means relates to a cable terminal connecting portion, and has a connecting fitting for receiving the conductor end of the cable to be connected, and an insulating reinforcing body surrounding the connecting fitting and the cable end. The connection fitting includes an electrode conductor having a substantially cylindrical portion having a tapered inner surface whose diameter is reduced toward an end, and a metal wedge having a substantially conical cylindrical shape fitted into the tapered inner surface, And a spring for pressing the wedge toward the end in the electrode conductor, which is a connecting portion of a cable terminal (claim 4).

At cable end connections, such as cable end connections, the cable ends are often terminated vertically, requiring the weight of the cable to be held at the end connections. According to the present invention, when the weight of the cable is applied to the conductor, a tightening force is further applied to the wedge for tightening the conductor, and a sufficient holding force can be obtained.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a sectional explanatory view showing the structure of the connection fitting according to the present invention when it is used for a cable intermediate connection portion. The connection fitting 31 includes a pair of metal wedges 23 inside the electrode conductor 21 having a substantially cylindrical shape.
Equipped with. The electrode conductor 21 is made of copper with good electrical conductivity,
Its inner surface is tapered so that its diameter is reduced toward both ends. In the present embodiment, the connection fitting 31 is assembled by connecting with the connection member 21c in a state where the two cylindrical members 21a and 21b having tapered inner surfaces are abutted in opposite directions. Wedges 23a and 23b are fitted and inserted into the pair of tapered inner surfaces of the electrode conductor 21, respectively.
Further, twisted wire conductors 7a and 7b of a pair of cables to be connected are inserted inside the respective wedges 23a and 23b. The diagram (b) shows the structure of the wedge 23. The wedge 23 is made of a copper alloy having appropriate electric conductivity and elasticity, and has a substantially conical cylindrical shape having a cylindrical inner surface and a conical outer surface. The wedge 23 has a plurality of axial slits 23d. This slit 23
The d is alternately cut from the small-diameter front end side and the large-diameter rear end side of the wedge 23, which allows the wedge 23 to contract radially like a spring. Wedge 2
The inner surface of 3 has a saw-toothed concave-convex surface 23c so that friction and electrical contact with the gripped stranded wire conductor 7b are enhanced. The end face of the wedge 23 on the rear end side of the large diameter is provided with a flange-shaped flange extending inward.

Referring again to FIG. 3 (a), a spring 25 is arranged between the wedges 23a and 23b which are arranged in opposite directions, sandwiched between the facing flanges,
A force that pushes the wedges 23a and 23b toward both ends is applied. As a result, the wedges 23a and 23b are
The tapered inner surface of the electrode conductor 21 is tightened to reduce the diameter, and a force to firmly grip the stranded conductors 7a and 7b is exerted. In this way, a pair of cable stranded conductors 7a, 7b
Are electrically connected to each other and mechanically firmly fixed to the electrode conductor 21.

FIG. 2 is an explanatory view of a cable intermediate connecting portion having the connecting fitting 31 as a component. In the present embodiment, the twisted wire conductors 7a, 7 of the pair of CV cables 1 are used.
b is connected by the above-mentioned connecting fitting 31, and the connecting fitting 31 is electrically and mechanically connected and fixed in the internal electrode 11. Since the other parts are the same as those shown in FIG. 6 described in the description of the conventional technique, description thereof will be omitted.

When such a connecting fitting 31 is used,
Fig. 3 shows how the cable conductor is connected. As shown in (a), a piece of stopper member 27 is detachably attached to the end of the connection fitting 31 with a screw 29. The stopper member 27 is a rectangular metal piece with a screw 29.
It has a shape with a hole for passing through. Stopper member 27
Is attached when the connecting fitting 31 is assembled in advance at the factory, and thereby the wedge 23 is held in a state of being pressed in the direction of contracting the spring 25. In this state, the wedge 23 is in a state of being expanded in the radial direction inside the tapered inner surface of the electrode conductor 21 by its own elasticity.
Although FIG. (A) shows only one side of the connection fitting 31, the other side is also the same.

At the construction site where the cable is connected, the stranded wire conductor 7b of the cable is inserted into the connection fitting 31, and then the screw 29 and the stopper member 27 are removed.
Then, as shown in (b), the wedge 23 is pushed rightward in the figure by the spring 25 and the diameter of the wedge 23 is reduced in the tapered inner surface of the electrode conductor 21.
Will be fixed against. After the twisted wire conductors of the pair of cables are fixed to each other, the insulating molded body 1 is provided around the cable end and the connection fitting 31 as shown in FIG.
3 is covered, and the rubber stress cones 17 are inserted from both sides of the insulating mold body 13. After that, a pressing mechanism for the stress cone 17, protective metal fittings and the like are attached, and the cable intermediate connection portion is completed.

In these operations, the stopper member 27
Since the stranded conductor can be fixed simply by removing, the conductor connection can be done quickly at the cable connection construction site.
There is no risk that the center axis of the stranded conductor will be displaced or bent as in the case of using pressure welding. Therefore, even when an insulating mold body or an insulating reinforcing body such as a rubber stress cone is provided in the periphery as in the above-described embodiment, there is no fear that the insulating reinforcing body and the cable shaft center are displaced from each other. Therefore, there is no concern that the surface pressure between the cable and the rubber stress cone will vary, which is advantageous in obtaining the pressure resistance characteristic of the prefabricated connection portion of the cable as in the above-described embodiment and the embodiment described later. In addition, it is desirable that the cables can be easily connected at the prefabricated connection portions of these cables and that the cables that have been once connected can be removed. In the connection fitting of the present invention, the force of pushing into the cable is applied to reduce the effect of the wedge, and then the wedge is pushed into the connection fitting, so that the cable conductor can be easily removed.

FIGS. 4 and 5 are explanatory views when the present invention is applied to a terminal connection portion in a gas of a cable, and FIG. 4 is an explanatory view showing a structure of the entire terminal connection portion.
The terminal connection portion 33 of the present embodiment is attached inside the gas-insulated power equipment, and the terminal of the CV cable 1 is inserted and connected. The terminal connection portion 33 is fixed to the equipment outer wall 43 of the gas-insulated power equipment, and in FIG.
An insulating gas such as sulfur hexafluoride gas is filled in the space inside the electric power equipment, which is the upper side of the. In the CV cable 1 to be connected, the sheath and the semiconductive layer on the outer periphery are stepped off at the end, and the insulating layer 5 is stripped off to expose the stranded conductor 7 of the cable. The exposed stranded conductor 7 is connected to the connection fitting 35. Connection fitting 35 and stranded conductor 7
An internal electrode 41 for adjusting the electric field distribution is provided around the, and the connection fitting 35 and the internal electrode 41 are electrically and mechanically connected. An insulating bushing 39 molded with epoxy resin is provided so as to surround the inner electrode 41 and the vicinity of the end of the cable 1, and the insulating bushing 39 is fixed to the inner surface of the outer wall 43 of the device. A rubber stress cone 17 is provided between the insulating bushing 39 and the insulator 5 of the cable 1.
Is inserted. The rubber stress cone 17 is composed of an insulating layer on the tip side and a semiconductive layer on the root side, and is pressed in the insulating bushing 39 by a pressing mechanism 49 which is a combination of a spring, a screw, and a push pipe. The insulating bushing 39 and the rubber stress cone 17 serve as an insulating reinforcing body that insulates the high voltage portion of the cable connecting portion. An adapter 45 and an insulating cylinder 47 are sequentially attached to the outer surface of the device outer wall 43, and a metal protective tube 51 is covered from the insulating cylinder to the sheath of the cable 1. The pressing mechanism described above is supported by the protective tube 51.

FIG. 5 shows details of the connection fitting 35.
The connection fitting 35 has a substantially cup-shaped electrode conductor 37 that receives the stranded wire conductor 7, and a wedge 23 provided inside thereof. The inside of the electrode conductor 37 has a tapered inner surface whose diameter is reduced toward the lower end in FIG. Then, on the tapered inner surface, the wedge 23 is urged downward in FIG. 5 by the spring 53, and the stranded wire conductor 7 is clamped and fixed. This mechanism is similar to that described above for the intermediate connection. The electrode conductor 35 has a shape in which a lid-shaped member 37b is attached to a cylindrical member 37a having a tapered inner surface, and an upper portion of the lid-shaped member 37b in the drawing is extended in a rod shape to form a pull-out rod 37c. Form. This withdrawal rod 37c is
It is connected to an internal device of a gas-insulated power device (not shown).
Further, a stopper fitting similar to that described in FIG. 3 is detachably attached to the end of the cylindrical member. Although FIGS. 4 and 5 have been described in the state where the terminal connecting portion is upright, the same applies to the case of lateral orientation.

The contents of the present invention are not limited to those described in the above embodiments. As an example of the cable intermediate connection portion, the type in which the rubber stress cone is pressed in the insulating mold body has been described, but the insulating reinforcing body may be formed without using such a mechanism. For example, the present invention is also applicable to a case where an insulating reinforcing body made of a tubular elastic insulator is put on the vicinity of the connection fitting and the cable end. Further, as the cable terminal connecting portion, not only the above-mentioned gas terminal connecting portion but also the air terminal connecting portion, the oil terminal connecting portion and the like can be applied. Further, the present invention can be applied to T-shaped and Y-shaped branch connection portions. Although an example in which a slit is provided in the conical tubular integral member as the structure of the wedge is shown, instead of providing the slit, the conical tubular member is divided into vertically divided members, and by providing a mechanism for connecting each other, The diameter may be expanded or contracted in the radial direction so as to have a function as a wedge for gripping the cable conductor.

[0023]

As described above, the cable connecting fitting of the present invention can be connected simply and quickly without the need for complicated soldering work or special tools or jigs when connecting to the cable conductor. It has a strong holding force against the pulling force acting on the cable conductor. It is also possible to remove the cable conductor once connected. further,
The center axis of the conductor is not displaced or bent at the time of connection, and it is particularly suitable for a cable intermediate connection part or a cable terminal connection part provided with an insulating reinforcement body around it.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view showing a structure of a connecting fitting used for a cable intermediate connecting portion.

FIG. 2 is a cross-sectional explanatory view showing a structure of a cable intermediate connection portion according to the present invention.

FIG. 3 is an explanatory diagram showing a work of connecting a cable conductor according to the present invention.

FIG. 4 is an explanatory cross-sectional view showing the structure of a cable terminating connection portion according to the present invention.

FIG. 5 is an explanatory cross-sectional view showing the structure of a connection fitting used for a cable terminating connection portion.

FIG. 6 is a cross-sectional explanatory view showing a structure of a conventional cable intermediate connecting portion.

[Explanation of symbols]

1 cable 5 insulating layers 7 Stranded conductor 11 internal electrodes 13 Insulation mold body 17 Rubber Stress Cone 19 Pressing mechanism 21, 37 Electrode conductor 23 wedge 25, 53 springs 27 Stopper member 31, 35 Connection fitting 39 Insulation bushing

Claims (4)

[Claims] 1. An electrode conductor having a substantially cylindrical portion having a tapered inner surface whose diameter decreases toward the end, and a substantially conical cylindrical metal wedge inserted into the tapered inner surface,
Cable conductor connecting fitting having a spring for pressing the wedge toward the end in the electrode conductor 2. An electrode conductor having a substantially cylindrical portion having a tapered inner surface whose diameter decreases toward an end, and a substantially wedge-shaped metal wedge fitted and inserted in the tapered inner surface,
A metal fitting for a cable conductor having a spring for pressing the wedge toward the end in the electrode conductor, and a stopper member detachably attached to the end of the electrode conductor to prevent movement of the wedge in the end direction. 3. A connecting fitting for connecting conductor ends of a pair of cables to be connected, and an insulating reinforcing body surrounding the connecting fitting and the cable end, wherein the connecting fitting faces both ends. An electrode conductor having a substantially cylindrical portion having a tapered inner surface that reduces in diameter, a metal cone-shaped wedge that is fitted and inserted into the tapered inner surface, and the wedge in the electrode conductor in both end directions. A cable intermediate connection part, which has a spring for pressing. 4. A connecting fitting for receiving a conductor end of a cable to be connected, and an insulating reinforcing body surrounding the vicinity of the connecting fitting and the cable end, wherein the connecting fitting has a diameter reduced toward an end portion. An electrode conductor having a substantially cylindrical portion having a tapered inner surface, a metal wedge having a substantially conical cylindrical shape fitted into the tapered inner surface, and the wedge pressed in the electrode conductor toward an end portion. A cable terminal connecting portion having a spring.