JPS6217965Y2 - - 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 through-holes located in a straight line and driving the pins 6, 6' into these through-holes, twisting and tensile strength were imparted. However, this work was extremely complicated and time-consuming, and also had the disadvantage of increasing costs. Furthermore, since the inner cylinder 1 made of porcelain or glass is supported in the outer cylinder 3 by the sealing plugs 2 and 2', it is vulnerable to internal and external impact forces, such as the impact of internal pressure when shutting off. Also, cracks may occur due to vibrations during transportation of the fuse, vibrations due to the influence of wind after installation, or when the fuse is accidentally dropped while being installed on a pole. There was a risk that cracks would develop and reduce the ability to interrupt large currents. Note that 7 and 7' are protective caps placed over the ends of the outer cylinder, and 8 and 8' are terminal force bars.

In view of the points mentioned above, this invention is easy to assemble, and has high torsional strength and tensile strength.
Furthermore, we provide a sealed electric wire fuse that increases the breakdown resistance of the inner cylinder and prevents damage due to internal and external forces.The outer peripheral surface of the inner end of the terminal fitting is provided with unevenness such as knurling and is fixed and integrated with the cap during cap molding. This cap seals the openings at both ends of the outer cylinder, and is characterized in that an elastic coating layer made of rubber or synthetic resin is provided on the entire or part of the outer peripheral surface of the inner cylinder.

Hereinafter, specific examples of the sealed electric wire fuse according to the 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 example, as shown in the figure, one end is attached to the terminal fitting 9' by soldering, and the other end is inserted into the mounting hole of the terminal fitting 9 and then fixed by compressing the terminal fitting from the outside. Reference numerals 10 and 10' denote caps fixed and sealed to the openings at both ends of the outer cylinder 3 using adhesive, high frequency, ultrasonic welding, etc., and the terminal fittings 9 and 9' are attached to these caps 10 and 10' in advance. It is mounted in a rotating position. Figure 3 shows an example of how it is installed. As shown in Figure C, unevenness is formed on the outer peripheral surface of the inner end of the terminal fitting by knurling, etc., and is integrated when the cap is molded. This makes it possible to maintain torsional strength and tensile strength. 1
Reference numeral 1 denotes a resilient coating layer provided on the entire or part of the outer circumferential surface of the inner cylinder 1. Both the inner and outer cylinders are densely coated with a rubber layer or a resin layer such as vinyl, silicone, polyethylene, or the like. The inner cylinder 1 is formed by being covered with a shrinkable tube made of the same material, or 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 coating layer 11 having such elasticity is provided, the coating layer 11 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. can be raised. This can prevent damage caused by internal and external forces. In addition, in FIG. 2, the symbols 12 and 12'
is a coating layer for the terminal fittings 9, 9' and the caps 10, 10', which is made of an elastic material like the coating layer 11, and protects the inner cylinder from external impact forces more effectively. There is. The procedure for assembling the sealed electric wire fuse is as follows. first,
One end of the fusible body 4 is fixed by soldering to the terminal fitting 9' integrated with the cap 10'. Next, one end of the structure consisting of the inner tube 1, the coating layer 11, and the outer tube 3 is fitted into the cap 10', and the other end of the fusible body 4 is aligned with the mounting hole of the terminal fitting 9 integrated with the cap 10. A cap 10 is fitted to the other end of the structure. Thereafter, the terminal fitting 9 may be compressed from the outside to fix the outer end of the fusible body 4 to the terminal fitting. The covering layers 12, 12' are finally placed over the outer periphery of the cap by utilizing their elasticity. The terminal fitting 9' and one end of the fusible body 4 may be fixed by compression instead of soldering.

As mentioned above, the sealed electric wire fuse of this invention has unevenness such as knurling on the outer peripheral surface of the inner end of the terminal fitting, which is fixed and integrated when the cap is molded, and this cap seals the openings at both ends of the outer cylinder. Since the structure is such that a resilient covering layer made of rubber or synthetic resin is provided on the entire or part of the outer peripheral surface of the inner cylinder, which has weak mechanical strength, assembly of the fuse is extremely simple, and wire connection is easy. In addition to being able to withstand the twisting and tensile forces that are applied at times, it is also resistant to shock internal pressure when shutting off, vibrations during transportation, vibrations due to the influence of wind after installation, and even when dropped during work on a pole. However, it was possible to prevent damage to the inner cylinder, thereby providing an extremely practical sealed wire fuse.

[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 how the terminal fitting is attached to the cap. It's a thing, A
is a front view in the installed state, B is a right side view, and C is a front view of only the terminal fitting. 1... Inner cylinder, 3... Outer cylinder, 4... Fusible body, 9,
9'...Terminal fitting, 10,10'...Cap, 1
1...Covering layer.

Claims (1)

[Scope of utility model registration request] It has an inner and outer fuse cylinder with an inner cylinder made of porcelain or glass material and an outer cylinder made of polycarbonate resin, etc., with terminal fittings for connecting electric wires protruding from the openings at both ends of the outer cylinder, and both openings are capped. In a sealed electric wire fuse in which a fusible body is connected between the terminals in an inner cylinder, the terminal fitting has irregularities such as knurling on the outer peripheral surface of the inner end,
It is fixed and integrated during cap molding, and
In the whole or part of the outer circumferential surface of the inner cylinder,
A closed electric wire fuse in which a resilient covering layer made of rubber or synthetic resin is densely provided between the inner and outer cylinders.