JPS6128376Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is mainly installed on outdoor power lines,
This relates to a sealed wire fuse that protects power distribution lines by shutting off the overcurrent or large current due to overload or short circuit, etc., silently and without emission.

Such wire fuses are required to have strength against twisting and tensile forces applied when connecting wires, but conventional wire fuses have a structure that takes a lot of time and reduces work efficiency. They had adopted a bad structure.

Therefore, the purpose of this invention is to provide a highly practical electric wire fuse that is easy to assemble and can reduce costs accordingly.

First, the conventional structure will be explained with reference to FIG. 1. Reference numeral 1 denotes an inner cylinder made of porcelain or glass, which is supported within an outer cylinder 3 by sealing plugs 2 and 2'. Reference numeral 4 denotes a fusible body supported within the inner cylinder 1 with both ends attached to terminal fittings 5, 5'. The terminal fittings 5, 5' are held by sealing plugs 2, 2', through which an electric wire can be connected to the protruding outer ends. The pins 6 and 6' are used as a means to provide twisting and tensile strength when connecting electric wires. By providing a through-hole located in a straight line and driving the above-mentioned pins 6, 6' into the through-hole, twisting resistance and tensile strength were imparted. However, this work was extremely complicated and time-consuming, and also had the disadvantage of increasing costs. Furthermore, the inner cylinder 1 made of porcelain or glass is directly connected to the outer cylinder 3 by means of sealing plugs 2 and 2'.
Because it was supported internally, it was vulnerable to internal and external impact forces.
For example, cracks may occur due to the shocking internal pressure when the fuse is shut off, or may occur due to vibrations during fuse transportation or the effects of wind after installation, or if the fuse is accidentally cracked during installation on a pole. There was also a risk that cracks would develop when the device was dropped, reducing its ability to interrupt large currents. Note that protective caps 7 and 7' are placed over the ends of the outer cylinder, and terminal covers 8 and 8' are terminal covers.

In view of the points mentioned above, this invention is easy to assemble, and has high torsional strength and tensile strength.
Moreover, it provides a sealed electric wire fuse that increases the breakdown strength of the inner cylinder and prevents damage due to external and external forces.The cap has a double structure of an inner cap and an outer cap, and both are fitted into each other in a non-rotating state. At the same time, the terminal fittings with irregularly shaped rotation prevention parts formed on the inner ends are fitted into the corresponding holes of the inner cap to connect them in a non-rotating state, and are fixed and integrated by the holding plate, and then the outer circumference of the inner cylinder is fixed. It is characterized by providing an elastic coating layer on the whole or part of the surface.

Hereinafter, specific examples of the sealed electric wire fuse according to this invention will be explained with reference to the drawings.

In FIG. 2, 1 is an inner cylinder made of porcelain or glass material similar to the conventional example, and 3 is an outer cylinder made of polycarbonate resin or the like. The fusible body 4 is supported within the inner cylinder 1 by having both ends attached to terminal fittings 9, 9' by soldering or the like. In this invention, the cap is the inner cap 10,1
0' and the outer caps 11 and 11' that contain it.
It has a heavy structure. The terminal fittings 9, 9' are preliminarily attached to the inner caps 10, 10' in a non-rotating state, and FIG. 3 shows an example of the attachment structure. That is, a deformed anti-rotation part 9a is formed at the inner end of the terminal fitting 9, and a corresponding fitting hole 10a is formed on the inner cap 10 side, so that the two can be combined in a non-rotating state. The presser plate 12 is fixedly attached, and the rotation stopper 9a and the fitting hole 10a are fitted to provide twisting resistance and tensile resistance. The inner caps 10, 10', to which the terminal fittings 9, 9 are attached in a non-rotating state by the above-described structure, can be fitted between the inner cylinder 1 and the outer cylinder 3 having the coating layer 13, and the inner caps 10, 10' Outer caps 11, 11' that can be fitted in a non-rotating state are fitted together, and the openings at both ends of the outer cylinder 3 are fixed and sealed with adhesive, high frequency welding, etc. It is. Figures 4 and 5 illustrate the fitted state of the inner cap and the outer cap, and the outer surface of the inner cap has a polygonal protrusion 10b as shown in Figure B of Figure 4 or a polygonal protrusion 10b as shown in Figure C. A protrusion 10c of an irregular shape is provided, and a correspondingly shaped fitting part 11a or 11 is provided on the outer cap 11 as shown in FIGS. 5B and 5C.
b, so that when the two are fitted, they cannot rotate independently of each other, thereby providing even higher torsion resistance and tensile strength.

The coating layer 13 is an elastic coating layer provided on the entire or part of the outer peripheral surface of the inner cylinder 1, and is coated with a rubber layer or a resin layer such as vinyl, silicone, or polyethylene, or made of the same material. The inner cylinder 1 is coated with a shrinkable tube made of the same material, or is formed by wrapping a sheet-like material made of the same material, thereby increasing the fracture resistance of the inner cylinder 1. In other words, when the covering layer 13 having such elasticity is provided, the covering layer 13 absorbs the impactive internal pressure, vibration, or external impact force at the time of interrupting a large current, so that the breakdown strength of the fuse inner cylinder is reduced. This can prevent damage due to internal and external forces. In addition, in FIG. 2, the reference numeral 14,1
4' indicates terminal fittings 9, 9 and outer caps 11, 1.
This is the covering layer 1', and like the covering layer 13, it is made of an elastic material, and further effectively protects the inner cylinder from external impact force.

As mentioned above, the sealed electric wire fuse of this invention has a cap with a double structure of an inner cap and an outer cap, and a terminal fitting with a deformed rotation stopper formed at the inner end is fitted into a corresponding hole in the inner cap. They are connected to each other in a non-rotatable state and are fixed and integrated by a presser plate, and the outer cap is attached to a fitting portion having a shape corresponding to a non-circular protrusion, such as a polygonal shape, provided on the outer surface of the inner cap. Because they are integrated and the openings at both ends of the outer cylinder are sealed with the inner and outer caps, the fuse assembly process is easier than with conventional models, and it can withstand twisting and tensile forces applied when connecting wires. It is something.

Furthermore, in this invention, a resilient covering layer made of rubber or synthetic resin is provided on the entire or part of the outer circumferential surface of the inner cylinder, which has relatively weak mechanical strength, so that it is possible to reduce the impact internal pressure when shutting off, and during transportation. This is an extremely practical sealed wire fuse that can prevent damage to the inner cylinder due to vibrations caused by wind, etc. after installation, or even if it is dropped while working on a pole. was able to provide the following.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of a conventional sealed electric wire fuse, Fig. 2 is a longitudinal cross-sectional view showing an embodiment of the sealed electric wire fuse according to this invention, and Fig. 3 shows the mounting structure of the terminal fitting. A is a front view in the installed state, partially shown in cross section, B is a left side view of the inner cap, C is a perspective view of the holding plate, D is a front view of the terminal fitting, E is a left side view, and Fig. 5 shows an example of the structure of the inner cap and outer cap. In Fig. 4, A is a front view of the inner cap to which the terminal fitting is fixed, B is a right side view of only the inner cap, and C is a right side view of the inner cap. 5 is a right side view showing another example; in FIG. 5, A is a vertical sectional view of the outer cap; B is a left side view of the outer cap that can house the inner cap of FIG. 4B;
4C is a left side view of an outer cap that can enclose the inner cap of FIG. 4C; FIG. 1... Inner cylinder, 3... Outer cylinder, 4... Fusible body, 9,
9'... Terminal fitting, 9a, 9'a... Rotating part,
10, 10'... Inner cap, 10a... Fitting hole, 10b, 10c... Non-circular protrusion, 11...
Outer cap, 11a, 11b...fitting portion, 12,
12'... Pressing plate, 13... Covering layer.

Claims (1)

[Scope of utility model registration request] It has a double internal and external fuse tube with an inner tube made of porcelain or glass and an outer tube made of polycarbonate resin, etc., with terminal fittings for connecting electric wires protruding from the openings at both ends of the outer tube, and both openings closed with caps. In a sealed electric wire fuse in which a fusible body is connected between these terminals in an inner cylinder, the cap has a double structure of an inner cap and an outer cap, and a terminal fitting with an irregularly shaped rotation stopper formed at the inner end is used. They are fitted into corresponding holes in the inner cap, connected to each other in a non-rotating state, and fixed and integrated by a holding plate.
The outer cap is fitted in a non-rotatable state at a fitting portion having a shape corresponding to a non-circular protrusion provided on the outer surface of the inner cap, and the openings at both ends of the outer cylinder are sealed with the inner and outer caps, and the inner cap is closed. A closed type electric wire fuse that has an elastic coating layer made of rubber or synthetic resin provided on the entire or part of the outer peripheral surface of the cylinder.