JPS6077334A - Quick interruption type fuse - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a fuse that has a fast-acting performance and is used in a rectifying circuit of a rotating shaft portion of a rotary generator, etc., and is particularly capable of withstanding external forces such as centrifugal force and impact force generated during rotation. This article relates to a quick-acting type fuse that has been improved.

Generally, this type of fast-acting fuse is provided for the purpose of protecting the rotating shaft of a generator or a rectifying element installed around the rotating shaft, or for quickly removing the faulty element from the circuit in the event that the rectifying element fails. Therefore, it is made of a thin plate such as a chime with excellent interrupting properties, with a narrow part in the center of the fuse fusible body, so that it operates with an extremely quick blowing time and suppresses the maximum passing peak current of the fault current to a low value. It is known that a fusible material is provided and an arc extinguishing agent such as crushed sand is filled around the fusible material. However, considering the shape of the above-mentioned thin sheet fusible material, the central narrow part is extremely fragile, so when it is fixed to the rectangular terminals at both ends, it is likely to be cut or broken, which often presents difficulties during assembly. There was a drawback.

In addition, there is no problem in use when it is stationary, but when it is installed on or around the rotating shaft of the above-mentioned generator, the central narrow part of the fusible body of the fuse is subjected to forced tensile force caused by the large centrifugal force caused by rotation. There is a disadvantage that when the fuse is cut under force, it is twisted and broken due to impact vibration, and therefore, it is necessary to specify the method, direction, and position of fuse installation.

The present invention has been made to eliminate the above-mentioned drawbacks, and has mechanical strength against external forces (particularly centrifugal force and impact vibration generated by rotational motion) applied to the fusible body, as well as excellent electrical performance. forming a reinforced fusible body in which the narrow part of the fusible body is clamped and locked with two sandwiching plates made of heat-resistant insulating material;
This increases υ mechanical strength, and the multiple small holes drilled in the clamping plates and the gaps between the clamping plates prevent the dissipation of Joule heat generated from the fusible material when a normal current passes through. To provide a quick-acting type fuse having a structure in which the metal molten gas generated from the fusible body is quickly absorbed into the surrounding arc extinguishing agent when a large current passes through such as in a short circuit, and the cutting effect is enhanced. This is the purpose.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 2A and 2B are cross-sectional views of a quick-acting fuse of the present invention, and the same parts as in FIG. 1 are designated by the same reference numerals.

In the figure, 1 and 1' are rectangular terminals made of a metal good conductor, and each of the rectangular terminals 1 and 1' has a mounting hole 1all on the outside.
'a, inwardly facing fusible body connection fixing groove 1c+1'
c, and two screw holes bored in the square terminal 1 that communicate with the outside for filling arc extinguishing agent, and into which either one of the sword-shaped terminals 1 and 1' is inserted. A tube 3 made of a heat-resistant insulating material is covered, and a core portion 3 and a double-edged terminal 1.1' are fixed by driving radially with a plurality of rivets 2.

Inside the cylinder 3, the soldering margins 4b and 4c are square terminals l,
1' is fitted into the fusible connection groove 1 (!, 1'c) and the solder 9
The reinforcing fusible body 1o as shown in Fig. 4 was fixed by
is arranged, and furthermore, two screw holes ib communicating from the outside are provided.
An arc extinguishing agent 8 such as silica sand is filled so that the reinforcing fusible body 1o is buried therein, and the arc extinguishing agent 8 is closed with a screw 7. FIG. 3 is a perspective view showing the assembly structure of the reinforcing fusible body 1° of the quick-acting fuse of the present invention. According to this figure, the ribbon-shaped fusible body is made of a thin plate of silver or the like and has a narrow portion 4a in the center. 4 and a small hole 5a in the short side direction of the rectangle.

5b, 5c, and two sandwiched sheets made of glass fiber melamine resin, etc., which has heat resistance, insulation, and high mechanical strength, and has a small hole of 5d + se + sf + 5g in the vertical direction with the small hole 5b as the axis. Using the plates 5, 5', the narrow part 4a of the fusible body 4 is connected to the small hole 5a+s'a in the center of the clamping plates 5, 5'.
The fusible body 4 is sandwiched and overlapped so that the locking holes 5h and s'h, 5i and 5'l and 5j and s'j+sk and 5'k match, and the locking holes 5h are aligned. and 51 and 5j and s k The KU-shaped clasp 6 is inserted into the locking holes 5' h, 5/ i and s/ of the clamping plate 5'.
The reinforcing fusible body 10 shown in FIG. 4 is formed by penetrating J and 5'k and then bending and locking.

The reinforcing fusible body 10 has left and right soldering margins 4b.

4C, the central narrow part 4a of the fusible body 4 is clamped and locked by the clamping plates 5, 5', so even if an external force is directly applied to this part, no bending or twisting will occur, and the machine Coercive pressure is greatly improved. Therefore, even if the fusible body 4 is very thin, it can be easily handled during manufacturing operations, and the assembly process becomes extremely efficient.

Also, the reinforced fusible body 10 assembled as a quick acting fuse
In this case, the edges in the short side direction of the two clamping plates 5゜5' that sandwich the fusible body 4 are fitted and fixed in the opposing groove 1ell'C between the rectangular terminals 1 and 1' in a nearly fitted state. Therefore, the edges of the short sides of the clamping plates 5 and 5' are blocked by the opposing walls of the double-edged terminals l and 1' against external forces applied in the longitudinal direction of the fuse body, so that the clamping plates 5° 5', there is no movement, etc. Therefore, secondary mechanical deformation such as bending or twisting is prevented in the narrow portion 4a of the fusible body 4, and a stable state can be maintained at all times.

Next, in terms of electrical performance, the small holes 5a to 5g and 5/a to s/g formed on the surfaces of the two sandwich plates 5 and 5' on which the reinforcing fusible material 1O is formed are impervious to the rated current that normally flows. The Joule heat generated from the melt 4 is evenly dissipated into the cylinder 3, and when a large current passes due to a short circuit, the metal molten gas from the melt 4 is quickly absorbed into the surrounding arc extinguisher 8, increasing the breaking effect. has advantages.

Furthermore, more conveniently, the two sandwiching plates 5, 5' that sandwich the fusible material 4 have small holes 5h and 51 (5'h and 5') on their surfaces.
'i), 5j and 5k (5'j and 5'k) are locked with the U-shaped clasp 6, so there is a minute gap sb between the stacks, and this gap occurs when shutting off. This has the effect of making it easier to diffuse the ejection of molten metal gas, arc, etc. into the arc extinguisher 8.

If the rated current is further increased, the number of reinforcing fusible bodies 10 may be increased as necessary, for example, as shown in FIG. That is, in addition to the facing groove IC91'C of the double-edged terminals 1, 1', there is another facing groove 1d in parallel thereto.

1/d is provided in advance, and both ends 4b and 4c of the reinforcing fusible body 10 are fitted into this groove in the same manner as described above and fixed with solder 9. A strong reinforced fusible body made by sandwiching the narrow part of the fusible body between two clamping plates without applying any stress is placed inside the cylinder, which streamlines the quick-acting fuse assembly process. It is possible to obtain a significant improvement in mechanical strength.
Regarding the installation of conventional quick-acting type fuses, it is now possible to install them in any way you like, without having to consider the installation method or direction separately, since it is the rotating shaft of the generator, and it is fast-acting without any electrical problems. shape fuse can be provided.

[Brief explanation of drawings]

FIG. 1(A) is a cross-sectional view of a conventional quick-acting fuse, FIG. 2(B) is a cross-sectional view along line x-x', and FIG. Figure (B) is a Y-Y' cross-sectional view, Figure (C) is a longitudinal cross-sectional view, Figure 3 is a perspective view showing the assembly configuration of the reinforcing fusible body of the quick-acting fuse of the present invention, and Figure 4 (
A) is a perspective view of the reinforcing fusible body of the quick-acting fuse of the present invention seen from one side, the same figure ←) is a perspective view of figure (A) seen from the other side, and Fig. 5 is a longitudinal cross-section showing still another embodiment of the present invention. It is a front view. In the figure, 1 is a square terminal, 2 is a rivet, 3-piece insulating tube,
4 is a fusible body, 5 is a clamping plate, 6 is a U-shaped clasp, 7 is a screw, 8 is an arc extinguisher, 9 is solder, and 10 pieces are a fusible body for reinforcement.

Claims (1)

[Claims] In a quick-acting fuse which is fitted into opposing grooves 1c and l'c of 1', bonded with solder 9, and filled with an arc extinguishing agent 8, the fusible body 4 is Both ends 4b. 4C is left as a soldering part, and the surface is made with multiple small holes 5a.
~5g, 5'a~5'g and locking holes 5h~5, 5
The sandwiching plates 5, 5' made of two congruent heat-resistant insulating materials with holes /h to 5'k are inserted into the fusible body 4, and the central narrow part 4a is the central hole 5b, 5/b of the sandwiching plate. The clamping plates 5.5' are stacked with the fusible body 4 in between so that the holes are exposed from the holes 5h+51 and 5h'+5' and the respective holes match.
A reinforcing fusible body 1 in which U-shaped clasps 6 are inserted into r, sj, 5 and 5'j, s'k and secured by bending the tips.
0, and after fitting both ends 4b and 4c of the reinforcing fusible body 10 into the opposing grooves ic+t'c of the double-edged terminals 1 and 1',
The tube 3 can be overturned by joining and fixing with solder 9, and the double-edged terminal 1
, 1' are fixed with a plurality of rivets 2, and an arc extinguishing agent 8 is filled through two screw holes ib communicating from the outside of the cylinder 3, which are closed with screws 7. Shape fuse.