JPH0337378B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high voltage coaxial cable terminal processing method in which the insulating rubber interposed between the outer wall of the coaxial cable center conductor insulator and the inner wall of the insulating container is improved.

When transmitting high voltage through a coaxial cable, it is necessary to shorten the creepage distance of the cable center conductor insulator in order to downsize the terminal processing section.

Figure 1 shows the terminal processing section of a conventional high voltage coaxial cable, where 1 is the outer conductor of the coaxial cable, 2
is a coaxial cable center conductor, 3 is a coaxial cable center conductor insulator, 4 is an outer conductor connection fitting, 5 is an outer conductor connection flange, 6 is a center conductor connection flange,
7 is an insulating container, 8 is a semiconductor electric rubber, 9 is an insulating rubber, and 10 is a spacer.

As shown in Fig. 1, an insulating rubber 9 is inserted between the outer wall of the coaxial cable center conductor insulator 3 and the inner wall of the insulating container 7, and the contact pressure between the inner and outer walls of the insulating rubber 9 improves the withstand voltage. If the contact pressure is too small, the necessary withstand voltage will not be obtained, and if the contact pressure is too large, it will have negative effects such as deforming the coaxial cable. In addition, it required a mechanism to obtain the necessary pressure, resulting in a complicated structure.

The present invention aims to provide a high voltage coaxial cable termination method that eliminates the above-mentioned drawbacks.

The present invention aims to obtain a pressure control mechanism using insulating rubber itself, and an embodiment shown in FIGS. 2 and 3 will be described below. In addition, Figures 2 and 3
In the figure, the same or corresponding parts as in FIG. 1 are given the same reference numerals.

FIG. 2 shows an embodiment of the terminal processing section of a high voltage coaxial cable according to the present invention, in which a stepped portion is provided on the outer wall of the insulating rubber 9 to form a close contact portion 9A and a non-contact portion 9B, and the close contact portion 9A is made of insulating rubber. The inner and outer walls of 9 are in close contact with the outer wall of the coaxial cable center conductor insulator 3 and the inner wall of the insulating container 7, and a withstand voltage is obtained by the contact pressure. A gap 11 is provided between them so that the non-adhesive part 9B of the insulating rubber 9 can be easily compressed in the axial direction of the coaxial cable, and the pressure from the compression is transferred to the adhering part of the insulating rubber 9 through the insulating rubber 9 itself. 9A to obtain the contact pressure necessary for withstanding voltage.

According to the structure shown in Figure 2 above, it is possible to obtain the necessary contact pressure for insulation within the practical dimensional tolerance of the parts used, and it does not cause excessive stress on coaxial cables, etc. .

FIG. 3 shows another embodiment of the terminal processing section of the high voltage coaxial cable according to the present invention, which maintains the contact pressure between the outer wall of the coaxial cable center conductor insulator 3 and the inner wall of the insulating rubber 9 in the part having a gap. show.

In FIG. 3, the contact portion 9 is attached to the outer wall of the insulating rubber 9.
A and a non-contact part 9B with a wave-shaped cross section are formed, and in the contact part 9A, the inner and outer walls of the insulating rubber 9 are in close contact with the outer wall of the coaxial cable center conductor insulator 3 and the inner wall of the insulating container 7, and due to the contact pressure. A withstand voltage is obtained, and a gap 11 is provided between the outer wall of the non-contact portion 9B and the inner wall of the insulating container 7, and this gap 11 allows the outer wall of the coaxial cable center conductor insulator 3 and the insulating rubber 9 to Maintains contact pressure with the inner wall.

Next, as an example of an experiment, when the cable axial distance of the contact portion 9A of the insulating rubber 9 was 30 km, it was able to withstand an impact voltage of 200 kV.

As described above, the high voltage coaxial cable terminal processing method of the present invention forms a contact part and a non-contact part in insulating rubber, and creates a void between the outer wall of the non-contact part of the insulating rubber and the inner wall of the insulating container. By providing this, when the insulating rubber is compressed by applying force in the axial direction, it provides room for the insulating rubber to expand in the radial direction, and prevents an unnecessary increase in pressure caused by volumetric compression of the insulating rubber. The terminal treatment of the high voltage coaxial cable of the present invention transmits the pressure generated by the elastic deformation of the non-contacted part to the adhered part through the insulating rubber itself, increasing the contact pressure of the contact part and improving the withstand voltage. This part has the advantage of being able to be used in conventional high-voltage generators and impact voltage generators, and has great industrial and practical value.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the terminal processing section of a conventional high voltage coaxial cable, FIG. 2 is a sectional view of an embodiment of the terminal processing section of the high voltage coaxial cable of the present invention, and FIG. 3 is a sectional view of the terminal processing section of the high voltage coaxial cable of the present invention. FIG. 7 is a cross-sectional view of another embodiment of a coaxial cable terminal processing section. 1: coaxial cable outer conductor, 2: coaxial cable center conductor, 3: coaxial cable center conductor insulator,
4: External conductor connection fitting, 5: External conductor connection flange, 6: Center conductor connection flange, 7: Insulating container, 8: Semi-conductive rubber, 9: Insulating rubber, 9A: Close contact part of insulating rubber 9, 9B: Non-adhesive part of insulating rubber 9, 11: void.

Claims (1)

[Claims] 1 In the terminal processing section of high voltage coaxial cable,
An external conductor connecting flange is provided at the upper end of the insulating container having a stepped cylindrical cavity, and an internal conductor connecting flange is provided at the lower end, and the outer conductor of the coaxial cable is connected to the external conductor connecting flange, and the outer conductor is connected to the internal conductor connecting flange. The coaxial cable center conductors are connected respectively, and a cylindrical insulating rubber is inserted around the outer periphery of the coaxial cable center conductor insulator, and a cylindrical insulating rubber is inserted between the outer wall of the insulating rubber and the inner wall of the insulating container, and between the inner wall of the insulating rubber and the center of the coaxial cable. A method for terminal processing a high-voltage coaxial cable, characterized in that the conductor and the outer wall of the insulator are comprised of a portion where the insulating rubber comes into close contact with both or one of the outer walls and a portion where the insulating rubber does not come into close contact with the conductor and the outer wall.