JPH0135541Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a cable termination box that can facilitate transportation of the cable termination box.

Conventionally, a so-called slip-on type air termination box, as shown in FIG. It is composed of a hard insulator 4 and a sleeve 6 which encloses this hard insulator with a required gap and is filled with a high viscosity asphalt-based or polybutene-based insulating mixture. It has been known.

However, in a cable termination box having such a configuration, there is a breathing air space 7 within the sleeve 6, so that the cable termination box may fall over, be placed horizontally, rotate, or vibrate, etc. during transportation. There was a problem that air bubbles were mixed into the insulating mixture 5, and removal of the air bubbles was difficult due to the high viscosity.

For this purpose, as shown in FIG. 2, an insulating mixture is oil-tightly filled in the sleeve 6 together with a cushion material 8 made of sponge or the like, and as shown in FIG.
Attempts have been made to fill the insulating mixture 5 into the mantle 6 in an oil-tight manner without leaving any air space, and then attach a compensation tank 9 at a lower position. Therefore, it is difficult to maintain the cushioning function of the cushioning material 8 within the sleeve, and there is a drawback that reliability is lacking. Further, in the latter case, when applied to a slip-on type cable termination section, the existence of the compensation tank 9 becomes a hindrance in its handling, resulting in poor workability.

The present invention was developed with attention to these points, and attempts to solve the above-mentioned difficulties by filling the cannula with low-viscosity insulating oil, leaving some air space for breathing. .

Hereinafter, the present invention will be explained based on the drawings of one embodiment. Figure 4, with the same numbers attached to the same parts as in Figure 1.
In the figure, the lower end of a sleeve 6 having an upper metal fitting 10 and an upper cover 11 on the top is fixed near the outer circumferential line of the annular bottom plate 3, and a cable terminal portion (described later) is fixed near the inner circumferential edge. A lower end portion of a hard insulator 4 made of epoxy or the like and having an insertion hole 12 is housed within the sleeve 6 and fixed coaxially with the sleeve.

In the deep part of the insertion hole 12 of the hard insulator 4, the upper end is passed through the upper fitting 10 and the upper cover 11 in an airtight and slidable manner, and the lower end is fixed to the hard insulator 4. A receptacle 1 electrically connected to a conductor pull-out rod 2 is provided, and a low viscosity insulating oil 5' is filled between the sleeve 6 and the hard insulator 4, leaving a slight air space 7 for breathing. There is. Note that the low-viscosity insulating oil 5' is made of insulating oil for OF cables, silicone oil, polybdenum oil, etc., and its viscosity is approximately 1000 CS or less.

The lower end of the conductor pull-out rod 2 is fixed to the hard insulator 4 in the following manner, for example. That is, the conductor pull-out rod 2 is inserted from the insertion hole 12 side, and the stopper 13 formed at the lower end of the conductor pull-out rod is molded and fixed to the inner periphery of the hard insulator 4.
4 and is brought into contact with the stepped portion 15 of No. 4. Next, a fixing fitting 16 consisting of a double nut or the like that has been fitted in advance
is screwed into a screw 17 formed at a predetermined location of the conductor pull-out rod 2, and then tightened.

Further, the upper end portion of the conductor pull-out rod 2 is slidably penetrated through the upper metal fitting 10 and the upper cover 11 in the following manner. That is, as shown in FIG. 5, which shows an enlarged view of the main part, the through holes of the upper metal fitting 10 and the upper cover 11 through which the conductor pull-out rod 2 is passed are each made to have a slightly larger diameter than the outer diameter of the conductor pull-out rod 2. O between each large-diameter through hole and the conductor pull-out rod
This is accomplished by arranging rings 18 and 19.

Note that the O-ring 18 on the upper metal fitting side is tightened from above by a restraining metal fitting 20, thereby maintaining the seal in the cannula.

Next, the method of inserting the cable terminal section will be described. As shown in FIG. 6, the insertion hole of the termination box 21 has a cable terminal portion 2 with a bullet-shaped plug 23 attached to the tip of the conductor 22 exposed by the step stripping process.
4 is inserted, thereby inserting the plug 23 into the receptacle 1.

In addition, when inserting the cable terminal part, the cable semi-conducting layer 26 is placed on the outer periphery of the cable insulator 25 in advance.
A stress cone 27 is mounted across the space, and a pusher 28 is brought into contact with the inclined surface of the stress cone.

On the inclined surface of the stress cone, a protective fitting 30 whose lower end is sealed 29 by taping is compressed by a bolt 32 between a stop fitting 31 provided on the inner periphery of the middle part and a push fitting 28. A pressing force is applied by a spring 33.

In addition, in the figure, 34 is a cable shielding layer, 35 is a cable sheath, 36a to 36d are packings, and 3
7 and 38 indicate upper and lower fixing metal fittings, and 39a to 39d indicate bolts.

As mentioned above, in the present invention, a small amount of air space is left in the cannula constituting the unit type slip-on type air termination box and the low viscosity insulating oil is filled, so that the cannula can easily fall over during transportation. Air gets mixed into the insulating oil due to vibration, vibration, etc., but if the terminal box is assembled on the stand on-site, the insulating oil has a low viscosity, so
The mixed air quickly rises and disappears, no longer exists in the insulating oil, and the cable termination box returns to a usable state.

Therefore, in the present invention, a special bubble prevention device is not required, and a cable termination box that is easy to handle at a low price can be provided.

Further, since there is no need to take special consideration to the inclusion of air bubbles during transportation, the cable sleeve can be prevented from falling over, stacking on its side, or vibrating.

[Brief explanation of the drawing]

Figures 1 to 3 are longitudinal sectional views of a conventional slip-on type cable termination box, Figure 4 is a longitudinal sectional view of the slip-on type cable termination box of the present invention, and Figure 5 is a longitudinal sectional view of the main part of the upper part of the cannula. FIG. 6 is a vertical cross-sectional view of a main part showing a state in which a cable terminal part is inserted into a cable termination box according to the present invention. 1... Receptacle, 2... Conductor pull-out rod, 3...
...Annular bottom plate, 4...Hard insulator, 5'...Low viscosity insulating oil, 6...Tube.

Claims (1)

[Scope of utility model registration request] Near the outer periphery of the annular bottom plate, the lower end of a sleeve having an upper metal fitting and an upper cover is fixed to the top, and near the inner periphery, the lower end of a hard insulator is provided with an insertion hole for the cable end at its lower end. A part is housed in the mantle and is fixed coaxially with the mantle, and a part is located deep in the insertion hole of the hard insulator.
A receptacle is provided, the upper end of which airtightly and slidably penetrates the center of the upper metal fitting and the upper cover, and the lower end of which is electrically connected to a conductor pull-out rod fixed to the hard insulator; A cable termination box characterized in that a low viscosity insulating oil is filled between the sleeve and the hard insulator, leaving an air space above the sleeve.