JPS5837768B2 - Connection for power cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to connection parts for power cables, more particularly
The present invention relates to a connection structure that electrically and mechanically connects an electrode embedded in an insulating structural member and a sleeve that connects a cable conductor in an oil-stop connection box, termination box, etc. for an F cable.

When installing power cables using insertion assembly type accessories such as OF cables, the conductor connection part is covered with an insulator and the electrode embedded in the insulating structural member is It is necessary to electrically and mechanically connect the conductor sleeves.

Conventionally, the structure of the connection part such as the upper part is as shown in Fig. 1 and Fig. 2.
As shown in the figure, the conductors 2 of the OF cables 1 and 1 are connected by a sleeve 3, and a stop unit 4 made of an insulating material is fitted onto the sleeve 3, and this unit 4
After connecting the electrode 5 embedded in the conductor 3 to the conductor 3, the outer periphery of the connection part is covered with reinforcing insulating paper 6 and an outer box 7.

As shown in FIG. 2, the conductor 3 and the embedded electrode 5 are connected by fitting a locking part 8 on the outer periphery of the sleeve 3 at one end, a male thread 9 at the other end, and a 01J ring 10 at the middle part. A flange portion 12 having an inner diameter that fits onto the middle portion of the sleeve 3 is provided on the inner periphery of the embedded electrode 5, and a tightening fitting 13 is screwed into the male thread 9 of the sleeve 3 to tighten the fitting groove 11. By squeezing the flange portion 12 between the metal fitting 13 and the locking portion 8, the sleeve 3 and the electrode 5 are electrically and mechanically connected.

However, as mentioned above, the stop unit 4 is
In the structure in which the screw-in type fastening fitting 13 is inserted from the left side in FIG. It is very difficult to properly screw the fastening fitting 13 in this state because the screwed part of the screw cannot be directly seen, and if the screw is not screwed together accurately, resistance will occur when screwing in. Not only could it not be tightened to the end, but a sufficient mechanical connection could not be obtained, and the sleeve 3 and electrode 5 could not be tightened to the end.
There is a risk that the electrical connection between the two will be incomplete and dielectric breakdown will occur due to discharge.

This results in the drawback that assembly is difficult and electrical and mechanical connections may be insufficient.

This invention was made in order to eliminate the above-mentioned drawbacks, and the threaded part is preassembled in a visible state before the stop unit is inserted, so that the assembly work is easy and the structure is electrically and mechanically strong. The object is to provide a connection structure for power cables with which a connection can be obtained.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 6.

As shown in FIG. 3, the outer circumferential surface of the sleeve 3 has a locking part 21 at one end, a tapered part 22 at the other end, and a zero part at the middle part.
A male thread 25 is provided in the fitting groove 24 of the 1J ring 23 and at the small-diameter end of the tapered portion 22. An embedded electrode 5 is provided inside a stop unit that is externally inserted into the sleeve 3.

A flange portion 26 that comes into contact with the locking portion 21 is provided inside the embedded electrode 5, and the tapered portion 26 is located at a position corresponding to the tapered portion 22 of the sleeve 3 on the inner periphery of the flange portion 26.
A tapered portion 27 having a slope opposite to that of 2 is formed.

Therefore, when the stop unit is inserted into the sleeve 3 and the end of the flange portion 26 is pressed against the locking portion 21, the tapered portions 22 and 27 create an annular space between the sleeve 3 and the electrode 5 whose inner end becomes narrower. 28 is in full form.

A wedge fitting 31 and a screw-in type fastening fitting 32 are temporarily attached to the outer periphery of the sleeve 3 before the stop unit 4 is fitted onto the outside.

The wedge fitting 31 is formed by a wedge body 33 that is divided into a plurality of pieces so that the diameter can be expanded.
6, and each wedge body 33 has a tapered inner and outer surface and is shaped to fit into the annular space 28.

The tightening fitting 32 is formed using a nut having an outer diameter smaller than the inner diameter D of the flange portion 26 of the embedded electrode 5, and when tightened with a predetermined tool, the wedge fitting 31 is pushed into the annular space 28.

When the above-mentioned tightening metal fitting 32 and wedge metal fitting 31 are temporarily attached to the sleeve 3, the small diameter state of the wedge body 33 group is maintained by the pin 34 which can be freely inserted and removed as shown in FIG. Alternatively, as shown in FIG. 5, the wedge bodies 33 are connected by a slack copper plate or copper wire 35 for electrical bonding between the wedge bodies 33 and for temporary holding of the wedge fittings 31. It can be anything.

Further, the wedge body 33 of the wedge fitting 31 shown in FIG.
A tap hole 37 is provided with a tap hole 37, so that the wedge can be easily removed when disassembling the junction box.

Although not shown, for example, the tightening fitting 32 and the wedge fitting 3
A countersunk or the like may be interposed between the parts 1 and 1 to further ensure the connection.

The connecting portion of the present invention has the above-mentioned structure, and the connecting method will be explained next.

After connecting the cable conductor and the conductor sleeve 3, a wedge fitting 31 and a fastening fitting 32 are temporarily attached to the male threaded portion 25 of the sleeve 3.

The wedge fitting 31 and the fastening fitting 32 are fastened with a pin 34 as shown in FIG. 3, and the wedge body 33 is held in a small diameter state.

Since the temporary screwing of the tightening member 32 is performed before the stop unit is inserted and inserted, the screwing operation can be performed while being sufficiently visually monitored, so that easy and accurate screwing can be performed.

Next, insert the stop unit with the embedded electrode 5 into the sleeve 3.
Insert it externally.

As shown in FIG. 3, since the clamping fitting 32 and the wedge fitting 31 have a smaller diameter than the inner diameter D of the flange portion 26, the electrode 5 can be easily inserted until the flange portion 26 comes into contact with the locking portion 21.

After that, when the pin 34 is removed and the fastening metal fitting 32 is rotated and screwed in using a predetermined tool, the wedge body 33 of the wedge metal fitting 31 slides on the tapered portion 22 of the sleeve 3 and the annular space 32 is tightened.
8, and the diameter of its circumscribed circle increases.

When the wedge fitting 31 is pushed in the most, the inner and outer tapered surfaces of the wedge body 33 come into pressure contact with the tapered part 22 of the sleeve 3 and the tapered part 27 of the electrode 5, and are compressed into the annular space 28 as shown in FIG. It connects the sleeve 3 and the embedded electrode 5 electrically and mechanically.

As described above, according to the present invention, the wedge fitting and the tightening fitting are temporarily attached to the sleeve before inserting the stop unit, and then the tightening fitting is screwed in to form the wedge fitting between the sleeve and the embedded electrode. Since the stop unit is press-fitted into the narrow annular space at the inner end, the fastening fitting can be temporarily attached in a visible manner, and the tightening after inserting the stop unit becomes smooth, making the connection work extremely easy.

Further, since the fastening fitting can be screwed in reliably and smoothly, and the wedge fitting is press-fitted between the sleeve and the tapered portion of the electrode, it is possible to obtain an electrically and mechanically strong connection.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the conventional connection structure, Fig. 2 is an enlarged view of the main parts of the same, Fig. 3 is a cross-sectional view showing the connection part of the present invention in a state before connection, and Fig. 4 is the same as above. FIG. 5 is a front view of a wedge fitting used in the above, and FIG. 6 is a sectional view showing another example of the wedge fitting. 3...Sleeve, 4...Stop unit, 5...Embedded electrode, 22, 27...
・Tapered part, 28... annular space, 31...
・Wedge fitting, 32... Tightening fitting, 33...
・Cuneiform body.

Claims (1)

[Claims] 1. When the outer peripheral surface of the sleeve that connects the conductor of the cable and the inner peripheral surface of the embedded electrode in the stop unit fitted into the sleeve are fitted, the slopes are reversed so as to form an annular space where the inner end becomes narrower. A wedge fitting is provided with a tapered portion, is divided into a plurality of pieces so as to be able to expand the diameter of the sleeve before the stop unit is inserted, and has a circumscribed circle smaller than the inner diameter of the embedded electrode, and fits appropriately into the cross-sectional shape of the annular space. Attach a tightening fitting that has an outer diameter smaller than the inner diameter of the implanted electrode and is screwed together, and after inserting the stop unit, screw the tightening fitting to press-fit the wedge fitting into the annular space to expand its diameter, and attach the sleeve. A power cable connection section characterized by electrically and mechanically connecting embedded electrodes.