JPH06253443A - Prefabricated connection part for power cable - Google Patents

Abstract

PURPOSE:To finely measure the distribution of pressure applied directly to a rubber mold stress cone by arranging a piece of or a plurality of optical fiber pressure-sensitive sensors in the rear of the rubber mold stress cone, and monitoring the mounting pressure of the rubber mold stress cone, using this. CONSTITUTION:A rubber mold stress cone 4 is made by integrally molding the conductive rubber part 2 on rear side and the conical insulating rubber part 3 on the side of a pointed end. And, an optical fiber pressure-sensitive sensor or a rubber optical fiber pressure-sensitive sensor 1 is arranged in spiral shape at the rear, where a press metal fitting abuts, at the right of the conductive rubber part 2. Accordingly, the distribution of pressure applied to the rubber mold stress cone 4 can be measured accurately with the sensor 1, and besides, since this measures it with a light, it becomes possible to always measure the pressure distribution without being affected at the connection at current application.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a prefabricated type connection portion of a power cable.

[0002]

2. Description of the Related Art The structure of a conventional prefabricated type connecting portion will be described below with reference to the drawings. FIG. 3 is a cross-sectional view showing a part of the prefabricated type connection part, in which the tip of the power cable to be connected is stripped off, the cable conductor 10 is exposed and inserted into the connection sleeve 11, and the connection is made by pressure welding. It Next, the connection sleeve 11 is covered with the epoxy unit 7 having the embedded electrode 8, and the rubber mold stress cone 4 composed of the insulating rubber 3 and the conductive rubber 2 is provided on the outer periphery of the cable insulator 9.
And press it from the back by a pressing device composed of a spring 6 and a press fitting 5 provided in a connection part protection case 12 to bring the tip of the rubber mold stress cone 4 into contact with the taper surface of the epoxy unit 7 to assemble the connection part. Has been.

At this time, the rubber mold stress cone 4
In order to grasp the pressure distribution applied to the pressure device, conventionally, the change amount of the length of the spring 6 of the pressing device is measured, and whether the rubber mold stress cone 4 is attached to the taper surface of the epoxy unit 7 by applying an appropriate pressure. I was making a decision.

[0004]

However, since the measurement of the pressure distribution applied to the rubber mold stress cone of such a prefabricated type connection portion is an indirect measurement from the spring, an accurate pressure distribution can be obtained. Since it was not possible, and measurement on the actual line was also impossible, it was not possible to fully grasp the pressure change due to expansion and contraction due to the thermal behavior when the power cable was energized.

The present invention has been made in view of the above point, and it is possible to eliminate the above-mentioned drawbacks of the prior art, to directly measure the pressure distribution directly on the rubber mold stress cone, and to constantly monitor the actual line. It is also an object of the present invention to provide a prefabricated type connection part and a rubber mold stress cone in which measurement accuracy is extremely improved.

[0006]

SUMMARY OF THE INVENTION According to the present invention, an epoxy unit having embedded electrodes is arranged on the outer periphery of a conductor connecting pipe connecting cable conductors, and a rubber mold stress cone is provided between the cable insulator and the epoxy unit. In the prefabricated type connection portion for the CV cable which is mounted by the pressure of the pressing device, the mounting pressure of the rubber mold stress cone is one or a plurality of optical fiber pressure sensors or the rubber optical fiber pressure sensor is attached to the back of the rubber mold stress cone. It is a prefabricated connection portion for a power cable characterized in that it is provided on the monitor and can be monitored using it. A rubber mold stress cone for a power cable prefabricated connection, characterized in that the optical fiber pressure sensor or the rubber optical fiber pressure sensor is installed in a spiral shape on the back surface of the rubber mold stress cone.

[0007]

[Function] The pressure distribution applied to the rubber mold stress cone can be accurately measured by the optical fiber pressure sensor or the rubber optical fiber pressure sensor, and since it is measured by light, there is no influence on the connection portion when energized. It is possible to measure at any time.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view of a part of a rubber mold stress cone used for a prefabricated connection portion for a power cable, FIG.
FIG. 4 is a front view of a rubber mold stress cone. That is,
The rubber mold stress cone 4 is formed by integrally molding the conductive rubber portion 2 on the back side and the conical insulating rubber portion 3 on the tip side. A pressure sensor or a rubber optical fiber pressure sensor 1 is provided in a spiral shape.

The principles of the optical fiber pressure-sensitive sensor and the rubber optical fiber pressure-sensitive sensor will be described with reference to FIG. That is, when no external force acts on the optical fiber pressure-sensitive sensor and the rubber optical fiber pressure-sensitive sensor 1,
As shown in (A), the incident light 13 that has entered one end thereof is directly transmitted and becomes a transmitted light 14. However, Figure 4
As shown in (B), when an external force 15 acts on the optical fiber pressure sensitive sensor and the rubber optical fiber pressure sensitive sensor 1, the optical fiber pressure sensitive sensor and the rubber optical fiber 1
Is distorted by the external force 15, the incident light 13 incident on one end thereof is partially scattered at the distorted light, and the lost light 16
Occurs. Therefore, the transmitted light 14 is small.
The lost light 16 is proportional to the strain of the optical fiber pressure sensitive sensor and the rubber optical fiber pressure sensitive sensor 1 based on the external force. Therefore, the stress applied to the optical fiber pressure sensitive sensor and the rubber optical fiber pressure sensitive sensor 1 can be measured by measuring the transmitted light 14.

The rubber mold stress cone 4 thus formed is used to assemble a connecting portion as shown in FIG. That is, the tip of the power cable to be connected is stripped off to expose the cable conductor 10 and the cable insulator 9, and the cable conductor 10 is inserted into the connection sleeve 11 and pressure-contacted for connection. Next, the epoxy unit 7 having the embedded electrode 8 previously inserted in the power cable is moved around the outer circumference of the connection sleeve 11 to cover it. Then, the rubber mold stress cone 4 previously inserted in the power cable is fitted from the left and right, and the tips thereof are fitted to the tapered surfaces provided on the inner diameter side of the epoxy unit 7, respectively. Then, the spiral optical fiber pressure sensor and the rubber optical fiber pressure sensor provided on the back surface of the conductive rubber portion 2 of the rubber mold stress cone 4 by the pressing device composed of the spring 6 and the pressing member 5 attached to the connection portion protection case 12. The pressing member 5 is brought into contact with the sensor 1 from above, and the tip of the rubber mold stress cone 4 is assembled so as to press against the tapered surface of the epoxy unit 7.

At this time, whether or not the epoxy unit 7 and the rubber mold stress cone 4 are properly assembled is determined by connecting the light emitting element and the light receiving element to the optical fiber pressure sensor and the rubber optical fiber pressure sensor 1 and transmitting the light. It can be found by measuring the stress distribution applied to the rubber mold stress cone 4 due to the change of.

In the above example, the fiber provided on the back surface of the rubber mold stress cone 4 has been described as a spiral wound fiber. However, the fiber is separately installed on the outer layer, the middle layer and the inner layer on the back surface of the rubber mold stress cone 4. This makes it possible to measure the pressure difference between the inside and outside of the rubber mold stress cone.

[0013]

As described above, in the conventional prefabricated type connection portion, the pressure distribution applied to the rubber mold stress cone and the constant monitoring cannot be performed. It becomes possible to constantly monitor the pressure distribution on the cone,
As a result, the effect of thermal behavior on the actual line has become fully understood. Moreover, the pressure distribution can be easily understood by installing a plurality of pressure-sensitive sensors or measuring the pressure-sensitive distribution of the pressure-sensitive sensor, and in particular, the difference in pressure applied to the inner layer and the outer layer can be easily understood. .

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a configuration of a rubber mold stress cone applied to an embodiment,

[Figure 2] Rear view of the rubber mold stress cone,

FIG. 3 is a partial cross-sectional view showing a configuration of a power cable prefab connection portion of the embodiment;

4A and 4B are explanatory diagrams for explaining the principle of the optical fiber pressure-sensitive sensor. FIG. 4A shows a state where no external force is applied, and FIG. 4B shows a state where an external force is applied.

[Explanation of symbols]

 1 Optical Fiber Pressure Sensitive Sensor 2 Conductive Rubber Part 3 Insulating Part 4 Rubber Mold Stress Cone 5 Push Metal 6 Spring 7 Epoxy Unit 8 Embedded Electrode 9 Cable Insulator 10 Cable Conductor 11 Connection Sleeve 12 Connection Case Protective Case

Claims (3)

[Claims] 1. An epoxy unit having an embedded electrode is arranged on the outer periphery of a conductor connecting pipe connecting cable conductors to each other.
CV in which a rubber mold stress cone is mounted between the cable insulator and the epoxy unit by the pressure of the pressing device
In the cable prefabricated type connection part, one or more optical fiber pressure-sensitive sensors or rubber optical fiber pressure-sensitive sensors are installed on the back surface of the rubber-molded stress cone for the mounting pressure of the rubber-molded stress cone, and connection is made using this. A prefabricated connection for power cables, characterized in that it can be monitored. 2. A rubber mold stress cone for a power cable prefabricated connection, wherein the optical fiber pressure sensor or the rubber optical fiber pressure sensor is installed in a spiral shape on the back surface of the rubber mold stress cone. 3. A prefabricated connection portion for a power cable, characterized in that a plurality of the optical fiber pressure-sensitive sensor or the rubber optical fiber pressure-sensitive sensor are arranged on an inner layer, an inner layer and an outer layer on a back surface of a rubber mold stress cone. Rubber mold stress cone.