JPH0127393Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to cable terminations useful, for example, in horizontal or inverted installations of insulator termination boxes for rubber, plastic insulated power cables.

Conventionally, as shown in Fig. 1, when installing a cable end horizontally or upside down, a bellows 4 is provided inside the upper metal fitting 1 and the rain cover 2, covering the tip of the conductor pull-out rod 3. A device in which the inner chamber of the bellows and the inner chamber of the cable sleeve 5 are communicated is known.

However, at the end of the cable with such a configuration, since the conductor pull-out rod 3 is covered with the bellows 4, the height of the rain cover 2 must be increased by an amount corresponding to the expansion/contraction length L of the bellows 4. Up,
There is an inconvenience that the terminal 6 must be placed sideways. In addition, since the conductor pull-out rod 3 is fixed at the top of the sleeve 5, it is not suitable for forming a so-called slip-on type cable termination, which will be described later.

FIG. 2 shows a conventional example in which a cushioning material 7 is disposed in the upper part of the cable sleeve 5'. However, in the cable termination section having such a structure, there is a problem in the lifespan of the cushioning material 7. For ~40 years, it has been difficult to maintain the cushioning function within the cable terminations for high voltage cables, resulting in a lack of reliability.

FIG. 3 shows a conventional example in which a reservoir tank 8 that compensates for the expansion and contraction of an independent insulating fluid is connected below the cable end, which is separate from the end. When applied to a slip-on type cable termination, the reservoir tank 8 has the disadvantage that it becomes a nuisance in handling.

FIG. 4 shows a conventional example in which a donut-shaped bellows 10 is disposed around the outer periphery of the lower copper tube 9, but such a cable termination is also unsuitable for a slip-type cable termination.

That is, it is difficult to integrate the bellows 10 with the main body of the sleeve 5'' due to its position, and since the cable C passes through the center, the inner and outer diameters of the bellows 10 become larger than necessary, which is uneconomical. be.

The present invention has been made with attention to these points, and it is an object of the present invention to provide a cable termination section that can be arranged compactly and has a highly reliable hydraulic compensation mechanism.

Hereinafter, the present invention will be explained based on the drawings of one embodiment. In FIGS. 5 and 6, the cable termination section according to the present invention is mainly composed of a jacket unit 11 manufactured in advance at a factory and a cable terminal section 12 that is attached to this unit in the field.

The sleeve unit 11 has an insertion hole 13 at the lower end, a conductor pull-out rod 15 with a receptacle 14 in the insertion hole, an annular bottom plate 16 disposed below the conductor pull-out rod, and a conductor pull-out rod 15 provided with a receptacle 14 in the insertion hole. A hard insulator 17 is provided on the outer periphery with the tip of the conductor pull-out rod exposed, and its lower end extends from the lower position of the conductor pull-out rod and is fixed to the annular bottom plate 16; 17 with a desired spacing, and its lower end is fixed to the annular bottom plate 16.
8, an upper metal fitting 19 provided at the top of the cannula and having the conductor extraction rod 15 passed through it, and an upper cover 20 provided on the upper metal fitting and exposing the tip of the conductor extraction rod 15 to the outside thereof. , this upper cover and upper metal fitting 19
An annular bellows 21 provided in between and surrounding the conductor pull-out rod 15, a communication hole 22 formed in the upper metal fitting and communicating between the inner chamber of the cannula and the inner chamber of the bellows, and an annular bellows 21 that is filled in the inner chamber of the cannula and the inner chamber of the bellows. Insulating fluid 2
It is mainly formed by 3.

A large-diameter portion 24 and a stepped engagement element 25 connected to the large-diameter portion 24 are protruded from the lower end of the conductor pull-out rod 15 formed of a copper round rod or the like, and a garter spring 26 is attached to the outer periphery of this engagement element. One end of the finger socket 27 is locked.

The conductor pull-out rod 15 is fixed to the hard insulator 17 in the following manner. That is, after the large diameter portion 24 having the function of a stopper is engaged with the bottom surface 29 of the insertion hole of the internal shielding fitting 28 integrated on the periphery of the hard insulator, the double nut inserted into the conductor pull-out rod 15 is inserted. 30 is screwed into a screw 31 formed at a predetermined location on the conductor pull-out rod.

An upwardly extending ring 32 is implanted near the inner peripheral edge of the annular bottom plate 16, and the lower end of the hard insulator 17 is sandwiched between the rings and firmly fixed. Auxiliary fittings 33 and 34 are joined to the upper fitting 19 and the annular bottom plate 16 of the sleeve 18 made of an insulator or the like by cementing, respectively.The upper fitting 19 has a bottom plate 35 that constitutes the annular bellows 21.
However, the annular bottom plate 16 is fastened to the auxiliary fitting 34 by bolts 36a to 36d, respectively.

Reference numeral 37 denotes a packing provided between the conductor pull-out rod 15 and the upper fitting 19. This packing is tightened by screwing a holding fitting 39 into a screw 38 on the inner peripheral surface of a recess formed in the center of the upper fitting. The penetrating portion of the conductor pull-out rod is hermetically sealed.

Similarly, the penetration portion of the upper cover 20 is also hermetically sealed by the packing 40. The cable end portion 12 with a bullet-shaped plug 42 attached to the tip of the conductor 41 exposed by stripping the end portion is inserted into the insertion hole 13 of the sleeve unit 11, whereby the plug 42 is inserted into the receptacle 14. is inserted into the

In addition, when inserting the cable terminal part 12,
A stress cone 45 is attached in advance to the outer periphery of the cable insulator 43, spanning between the cable semiconducting layers 44, and a pusher 46 is brought into contact with the inclined surface of the stress cone.

On the inclined surface of the stress cone 45, a stopper 49 and a pusher 46 are provided on the inner periphery of the middle part of a protective metal 48 whose lower end is sealed 47 by taping.
A pressing force is applied by a spring 51 compressed by a bolt 50 therebetween.

In the figure, 52 is a bolt, 53 is a shielding layer, and 54 is a bolt.
indicates the sheath.

As described above, in the present invention, an annular bellows surrounding the conductor pull-out rod is provided between the upper metal fitting and the upper cover, and the inner chamber of the annular bellows is communicated with the inner chamber of the cannula. Since the oil pressure is compensated, it has the following effects.

(1) Since the hydraulic compensator is housed inside the upper cover, handling (especially transportation) of the cannula unit is easy.

(2) The conductor pull-out rod passes through the center of the annular bellows,
The conductor pull-out rod serves as a guide, so the first
Compared to the cable termination shown in the figure, the bellows will not bend even if the cable termination is installed horizontally, making it safer.

(3) Since the conductor pull-out rod can be fixed with a hard insulator and the conductor pull-out rod can be sealed at the upper metal fitting, the inside of the upper cover can be almost completely removed compared to the cable termination shown in Figure 1. It can be effectively used as a reservoir tank room. Therefore, the hydraulic pressure guarantee mechanism can be housed within the upper cover of the conventional height.

(4) Since the bellows is annular and the conductor pull-out rod is exposed from the center of the cable end,
It is easier to handle than the cable termination shown in FIG.

(5) Since the annular bellows is covered with the upper cover, there is no risk of the bellows being damaged and is safe.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of the main part showing a conventional cable termination part, Figs. FIG. 6 is a longitudinal cross-sectional view of the main part of the cable termination according to the present invention. DESCRIPTION OF SYMBOLS 11... Trunk unit, 12... Cable terminal part, 14... Receptacle, 15... Conductor pull-out rod, 17... Hard insulator, 18... Trunk tube, 19...
... Upper metal fitting, 20 ... Upper cover, 21 ... Annular bellows, 22 ... Communication hole, 23 ... Insulating fluid,
37...Patzking.

Claims (1)

[Scope of utility model registration request] an upper metal fitting provided on the top of the mantle having a conductor extraction rod in the center with the tip of the conductor extraction rod passed through in an airtight manner; and an upper part provided on the upper metal fitting with the tip of the conductor extraction rod passed through it; A cable termination section characterized in that an annular bellows is provided between the cover body and the conductor pull-out rod so as to surround the conductor pull-out rod, and the inner chamber of the annular bellows and the inner chamber of the sleeve are communicated with each other.