JPH0321175Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a cable oil stopper that is useful for alleviating electrical stress at both ends of a shield electrode in an insulating unit that constitutes an oil stop joint of an OF cable. It concerns the connection part.

[Technical background of the invention and its problems] In general, the oil stop joint of an OF cable consists of a pair of OF cable conductors 1, as shown in FIG.
An insulating unit 5 having a shielding electrode 4 embedded in the center of the inner layer is provided on a conductor connecting tube 3 which is compressed and connected to the conductor connecting tube 2. In addition, in FIG. 2, 8 is an epoxy bell mouth mounted on the reinforcing insulating layer 9;
10 is a connecting portion of the connecting portion 11; 12 is a connector; 1
Reference numeral 3 indicates a conductor connection fitting, and reference numeral 14 indicates an O-ring.

By the way, in the oil stopper connection portion of the cable having such a configuration, the insulation unit 5 made of epoxy or the like in which the shielding electrode 4 is embedded constitutes the main insulation and the oil stopper portion.

However, due to this configuration, both ends 4a of the shielding electrode 4
has the highest electrical stress.

Therefore, keeping the electrical stress at both ends of the shield electrode 4 low improves the insulation properties of the oil-proof connection part of the cable.

However, in the conventional cable oil-stop connection, both ends 3a of the conductor connecting tube 3 are located inside the both ends 4a of the shielding electrode 4 or in the vicinity of both ends of the shielding electrode, so the equipotential line 6 is shielded. The shielding electrode 4 is attracted toward the center of the electrode 4, and as a result, the electrical stress at both ends 4a of the shielding electrode 4 increases, resulting in dielectric breakdown at the ends 4a.

In order to solve this difficulty, the conductor connecting pipe 3
Conductor connecting pipe 3 by lengthening the sleeve part in the axial direction
It is sufficient to extend both ends of the shield electrode 4 beyond the positions of both ends 4a of the shield electrode 4, but if the sleeve portion of the conductor connecting tube 3 is lengthened in the axial direction, the compression connection work of the cable conductors 1 and 2 will be easier. In addition, the conductor connection tube bent after compression, making subsequent assembly difficult.

[Purpose of the invention] The present invention was made in order to solve these conventional problems, and aims to alleviate the electrical stress at both ends of the shielding electrode and provide an oil-proof connection for cables with good insulation properties. It is something.

[Summary of the invention] In other words, the oil-proof connection part of the cable of the present invention is a cable oil-proof connection in which a conductor connection pipe connecting a pair of cable conductors is covered with an insulating unit having a shielding electrode in the center of the inner layer. In the section, the outer periphery of both ends of the conductor connecting tube is set close to the inner peripheral surface of the shielding electrode and axially inward from the end of the shielding electrode as the proximal end, and the distal end is the end of the conductor connecting tube. The insulation unit is characterized by being surrounded by a cylindrical conductive cover extending toward the end of the insulation unit.

[Embodiment of the invention] Hereinafter, an embodiment of the invention will be described based on the drawings.

In Figure 1, in which the same parts as in Figure 2 are given the same numbers, a pair of OF cable conductors 1 are compressed and connected by a conductor connecting tube 3, and a shielding electrode 4 is embedded in the center of the inner layer of the conductor connecting tube 3. The point covered by the insulating unit 5 is the same as the oil stopper connection part of the cable of the conventional structure.

In the present invention, both ends of the conductor connection tube 3, that is, both ends 3a of the sleeve portion, are surrounded by cylindrical conductive covers 7 attached to both sides of the conductor connection tube 3.

The conductive cover 7 made of non-ferrous metal such as aluminum is divided into two parts, for example, and the tip part,
That is, the side of the conductor connecting tube 3 that covers the end 3a is tapered and extends beyond the end 3a of the conductor connecting tube 3 toward the end of the insulating unit 5.
Further, a base end portion 7 located near the inner circumferential surface 4b of the shield electrode 4 and closer to the center than the end portion 4a of the shield electrode 4
A screw hole (not shown) is bored in a.

After connecting the pair of cable conductors 1 and before covering the insulating unit 5, the conductive cover 7 locks the base end 7a to the shoulder 3b of the conductor connecting tube 3, and inserts a screw (not shown) into the screw hole. It can be attached to the side of the conductor connecting pipe 3 by screwing it.

Each tip of the conductive cover 7 is connected to an insulating unit 5.
The more it extends toward both ends of the
The slope of the equipotential line 6 becomes gentler, and the electrical stress at both ends 4a of the shield electrode 4 can be further alleviated.

In addition, in the above embodiment, both ends 3 of the conductor connecting pipe 3
In this example, a extends outward from the positions of both ends 4a of the shield electrode 4, but the present invention is not limited to such an embodiment, and both ends 3a of the conductor connecting tube 3 extend outside the positions of the ends 4a of the shield electrode 4. A similar effect can be obtained when the shield electrode 4 is located at substantially the same position as the positions of both ends 4a or inside thereof, and the electrical stress at both ends 4a of the shield electrode 4 can be alleviated.

[Effects of the invention] As explained above, according to the invention, the proximal end is near the inner circumferential surface of the shielding electrode and axially inward from the end of the shielding electrode, and the distal end is the conductor connecting tube. By attaching a cylindrical conductive cover that extends beyond the end toward the end of the insulating unit, the equipotential lines can be made smoother, so the electrical stress at both ends of the shield electrode can be reduced. can.

Therefore, it is possible to provide an oil-proof connection portion for cables with good insulation properties.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an oil-stop connection portion of a cable according to an embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view showing an oil-stop connection portion of a conventional cable. 1...Cable conductor, 3...Conductor connection pipe, 4...
...shielding electrode, 5... insulating unit, 6... equipotential line, 7... conductive cover.

Claims (1)

[Scope of utility model registration request] A conductor connection tube that connects a pair of cable conductors,
In an oil stop joint of a cable covered with an insulating unit having a shielding electrode in the center of the inner layer, the outer periphery of both ends of the conductor connecting tube is located near the inner circumferential surface of the shielding electrode and at the end of the shielding electrode. The cable is characterized in that the base end is located closer to the inside in the axial direction, and the distal end is surrounded by a cylindrical conductive cover that extends beyond the end of the conductor connecting tube toward the end of the insulating unit. oil stop connection.