CN112908801A

CN112908801A - Composite melt for fuse and fuse

Info

Publication number: CN112908801A
Application number: CN202110276854.2A
Authority: CN
Inventors: 段少波; 王欣; 石晓光; 戈西斌
Original assignee: Xian Zhongrong Electric Co Ltd
Current assignee: Xian Zhongrong Electric Co Ltd
Priority date: 2021-03-15
Filing date: 2021-03-15
Publication date: 2021-06-04

Abstract

The composite fuse body is characterized by being provided with a narrow diameter or a metallurgical effect point on the fuse body, and an insulating protective layer is coated on the narrow diameter or the metallurgical effect point. The composite melt can be used as a fuse melt. The composite fuse and the fuse have the advantages of difficult deformation of the fuse, quicker fusing, higher working reliability and improved rated current and breaking capacity of the fuse.

Description

Composite melt for fuse and fuse

Technical Field

The invention relates to the field of power control, in particular to a structure of a fuse used for a high-low voltage distribution system, a control system, electric equipment and the like.

Background

Fuses are widely used as protection devices in high and low voltage power distribution systems and control systems as well as in electrical equipment. The fuse has more types, and the common hot-melt fuse structure on the market at present comprises a contact knife, a gland, a melt, an arc extinguishing medium, a porcelain tube and the like. The working principle is as follows: when the current in the line exceeds a specified value, namely when fault current occurs, the line current passes through the melt through the contact knife, and a current sensing point (narrow neck) arranged on the melt is melted and disconnected in a certain time by utilizing the current heat accumulation effect, so that the arc is extinguished, and the fault current is safely cut off. At present, the thermal fuse fuses mostly adopt a plurality of rows of bent melts with narrow diameters.

It presents major problems and drawbacks:

1. the fuse element is weak at the melt throat and is easily damaged or deformed during the production process.

2. When the fuse fuses in multiple rows of narrow diameters, because gaps at fusing points of the narrow diameters are small, lap-joint adhesion of fusing points between different narrow diameters can occur, electric arcs cannot be extinguished quickly, and the insulation performance after the fusing is not facilitated.

3. The general fuse can not be fused in time delay due to the low heat accumulation of the narrow diameter of the fuse body under the lower multiple current, has long fusing time and can not realize the rapid protection

Disclosure of Invention

The technical problem to be solved by the invention is to provide a fuse element for a fuse, wherein the outer peripheral surface of the narrow diameter is an insulating protective layer, the fuse element can be rapidly fused when fused, and the outer periphery of the fuse element is the insulating protective layer, so that the bad phenomena that the fuse element can not be thoroughly disconnected due to the lap joint of the fused part after the fuse element is fused can be avoided.

In order to solve the technical problems, the technical scheme provided by the invention is that the composite melt for the fuse is characterized in that a narrow diameter or a metallurgical effect point is arranged on the melt, and an insulating protective layer is coated at the narrow diameter or the metallurgical effect point.

When there are a plurality of melt slots or metallurgical effect points, an insulating protective layer may be provided at each slot or metallurgical effect point or a plurality of slots or metallurgical effect points may be grouped, with an insulating protective layer being provided at each set of slots or metallurgical effect points.

The insulating protective layer is coated on the outer peripheral surface of the melt narrow diameter or the metallurgical effect point.

The composite fuse body is located in the fuse shell, and the two ends of the composite fuse body are in conductive connection with the contact knife in the fuse shell.

When the composite melt is densely arranged, the narrow diameter or metallurgical effect points of the composite melt are arranged in a staggered mode.

And arc extinguishing substances are filled in a gap between the composite melt and the inner wall of the fuse shell.

The invention has the beneficial effects that:

1. the plastic insulating protective layer is wrapped at the narrow diameter position or the metallurgical effect point of the melt, so that the rigidity of the melt is enhanced, and the melt is not easy to deform.

2. The insulating protective layer can protect the weak part of the melt narrow diameter or the weak part of the metallurgical effect point and avoid the damage of the narrow diameter part or the metallurgical effect point.

3. The insulating protective layer separates many fuse-elements fusing department, and the fusing department is difficult to take place the overlap joint adhesion during fusing for electric arc extinguishes fast, is favorable to fusing back insulating properties.

4. The insulating protective layer is made of plastic, can be melted when the melt narrow-diameter part or the metallurgical effect point generates heat, accumulates heat storage capacity and prevents heat at the narrow-diameter part or the metallurgical effect point from dissipating, and fusing of the melt is accelerated.

5. The high-temperature heating when the melt is fused enables the plastic insulating protective layer material to be melted to generate gas, the air pressure at the fused fracture is increased, arc extinction is facilitated, and the arc extinction time is shortened.

Drawings

FIG. 1 is a schematic view of a composite melt structure.

FIG. 2 is a schematic cross-sectional view of a composite melt.

FIG. 3 is a schematic cross-sectional view of a fuse using the composite melt.

Detailed Description

With respect to the above technical solutions, preferred embodiments are described in detail with reference to the drawings. Wherein:

referring to fig. 1 and 2, the composite melt includes a conductive melt 2, the melt 2 is a strip-shaped sheet structure, at least one narrow diameter 3 is arranged on the melt 2, an insulating protection layer 4 covering the narrow diameter is arranged on the outer peripheral surface of the narrow diameter 3, and two ends of the melt are positioned outside the insulating protection layer. When a plurality of narrow diameters are arranged on the melt, if the interval of each narrow diameter is wider, an insulating protective layer can be arranged at each narrow diameter; when the narrow diameters are adjacent to each other, an insulating protective layer can be arranged on the peripheries of the narrow diameters; or a plurality of slits are grouped, and an insulating protective layer is arranged at each group of slits.

In order to reduce the volume of the composite melt better, the insulating protective layer is optimally coated, attached and fixed on the outer peripheral surface of the melt. The insulating protection layer is made of plastic or other insulating materials. The composite melt having an insulating protective layer on the outer peripheral surface of the narrow diameter portion has sufficient rigidity and is less likely to be deformed in the lateral or longitudinal direction. When the composite melt is multiple, the existence of the insulating protective layer at the narrow diameter part can ensure that the distance between the melts is relatively uniform, the insulating capability is improved, the composite melt is not easy to deform in the production process, and the composite melt is easier to assemble.

The melt can also be provided with a plurality of metallurgical effect points, the metallurgical effect point structure coats a layer of low-melting-point metal layer on the outer peripheral surface of the melt, and when the low-melting-point metal layer is melted, the melting of the melt at the cladding part of the low-melting-point metal layer is accelerated. An insulating protective layer can be coated on the outer peripheral surface of the metallurgical effect point. When a plurality of metallurgical effect points are arranged on the melt, if the interval of each metallurgical effect point is wider, an insulating protective layer can be arranged at each metallurgical effect point; when the metallurgical effect points are close to each other, an insulating protective layer can be arranged on the periphery of the plurality of metallurgical effect points; or grouping a plurality of metallurgical effect points, and arranging an insulating protective layer at each group of metallurgical effect points.

Or a plurality of narrow diameter and metallurgical effect points are arranged on the melt at intervals, and the outer peripheral surfaces of the narrow diameter or the metallurgical effect points are coated with insulating protective layers. When a plurality of narrow diameters and metallurgical effect points are arranged, and the plurality of narrow diameters and the plurality of metallurgical effect points are adjacent to each other, an insulating protective layer can be arranged on the periphery of the plurality of metallurgical effect points; or grouping a plurality of narrow diameter and metallurgical effect points, and arranging an insulating protective layer on the outer peripheral surface of the narrow diameter and metallurgical effect point of each group.

The fuse, see fig. 3, comprises a housing 5, the composite melt 1 is arranged in the housing 5, as shown in fig. 3, and both ends of the composite melt in the housing 5 are welded and fixed on a contact knife 6 in the housing. And filling arc extinguishing substances in a gap between the composite melt and the inner wall of the fuse shell. The arc-extinguishing medium is generally quartz sand, and can also be arc-extinguishing gel or other arc-extinguishing substances which are helpful to arc extinction.

The existence of the insulating protective layer at the narrow-diameter part or the metallurgical effect point of the composite melt enables the composite melt to be densely arranged in the shell without causing overlapping, for example, a plurality of composite melts are densely arranged, and the dense arrangement of the composite melts can improve the rated current and the breaking capacity of the fuse. When a plurality of composite melts are densely arranged, the narrow diameter or metallurgical effect points on the composite melts need to be arranged in a staggered mode so as to ensure the insulation resistance of the adjacent fusing fracture after the composite melts are fused. If not misplaced and arranged, when fusing, a plurality of fractures are generated at the same position, and the generated electric arc easily causes short circuit at the fractures and can not be effectively disconnected.

When the composite melt is fused, the melt narrow diameter part or the metallurgical effect point melts the insulating protective layer when heating, the insulating protective layer can accumulate heat and prevent the heat dissipation of the melt fusing point, and the fusing of the melt is accelerated.

The high-temperature heating when the fuse-element fuses makes insulating protective layer melt and produce gas, increases the atmospheric pressure of melting point fracture department, is favorable to the arc extinguishing, shortens arc extinguishing time. Moreover, due to the existence of the insulating protective layer, when the melt is fused, the bad phenomenon of lap joint conduction at the fused part can not be generated.

The working principle of the composite fuse-element is used:

when the current in the line exceeds a specified value, namely when fault current occurs, the line current passes through the melt through the contact knife, and the current sensing point arranged on the melt, namely the narrow diameter or metallurgical effect point, is melted and disconnected in a certain time by utilizing the current heat accumulation effect. Due to the existence of the plastic insulating protective layer coated on the melt throat or the metallurgical effect point, the melt throat or the metallurgical effect point is spaced, lap joint adhesion is not easy to occur at a melt fracture, and the plastic insulating material at the fracture is gasified at high temperature to generate higher pressure to help arc extinction, so that electric arcs are extinguished in an arc extinguishing medium quickly, and fault current is cut off.

Claims

1. The composite melt for the fuse is characterized in that a narrow diameter or a metallurgical effect point is arranged on the melt, and an insulating protective layer is coated at the narrow diameter or the metallurgical effect point.

2. The composite melt for a fuse according to claim 1, wherein when there are a plurality of melt slits or metallurgical effect points, an insulating protective layer is provided at each slit or metallurgical effect point or a plurality of slits or metallurgical effect points are grouped, and an insulating protective layer is provided at each group of slits or metallurgical effect points.

3. The composite melt for a fuse according to claim 1, wherein the insulating protective layer is coated on an outer peripheral surface of the melt throat or the metallurgical effect point.

4. A fuse element made of a composite melt according to any one of claims 1 to 3, wherein the composite melt is located in a fuse housing, and both ends of the composite melt are electrically connected to contact blades located in the fuse housing.

5. A fuse element made of a composite melt according to claim 4, wherein the narrow diameters or metallurgical effect points of the composite melt are arranged in a staggered manner when the composite melt is arranged densely.

6. A fuse element made from a composite melt according to claim 4, wherein the gap between the composite melt and the inner wall of the fuse housing is filled with an arc suppressing material.