Arc extinguishing medium, fuse and manufacturing method thereof

Abstract

The invention discloses an arc extinguishing medium, a fuse and a manufacturing method thereof, the arc extinguishing medium comprises vermiculite and quartz sand, and the mass ratio of the vermiculite to the quartz sand is (5-8): (12-15). The quartz sand and the vermiculite form high-compactness powder, so that the arc column has a buffering and weakening effect on the enhancement of the pressure of the pipe wall, and the doped vermiculite and quartz sand have relatively good insulativity, flame retardance, adiabaticity and water absorption, so that the influence of an electric arc can be weakened; in addition, vermiculite is doped, after the vermiculite is heated and expanded, a stress effect causing plastic deformation of the fuse link is given, and the problem that the low-power overload breaking speed is too low due to the fact that only the thermal effect of the fuse link is relied on is solved.

Description

Technical Field

[0001] The present application relates to the technical field of electrical protection elements, and in particular to an arc extinguishing medium, a fuse and a manufacturing method thereof. Background Art

[0002] As a protective device for short circuit or overload current systems, fuses are widely used in electrical equipment, especially in high-voltage power distribution systems, large current loop systems, etc., and are the key to ensuring safe operation. When abnormal currents such as short circuits and large currents appear in the loop, due to the thermal effect of the energized fuse in the fuse, its heat generation continues to increase and heat accumulation continues to rise. When it reaches its tolerance limit (generally based on the melting point), it disconnects to protect each device in the loop.

[0003] Under high voltage and low current, the heat accumulation of the fuse is slow, the melting speed is slow, the gap generated is small (or in a crack state), and the ion concentration in the arc column is relatively high, which makes it easy to have high-energy arcs. One of the difficulties of fuses at present is that the design of the fuse is not enough to solve the problem of insufficient heat accumulation under low current and poor breaking capacity. Fuses generally use insulating materials such as solidified quartz sand to absorb melting energy or adsorb vaporized metal to achieve the purpose of arc extinguishing. Although it has a certain arc extinguishing effect, it is difficult to fundamentally solve or weaken the impact of the arc. Therefore, how to solve the poor arc weakening effect of the arc extinguishing medium has become the key. Summary of the invention

[0004] The purpose of the present application is to provide an arc extinguishing medium, a fuse and a method for manufacturing the same, so as to solve the problem of poor arc weakening effect.

[0005] To achieve the purpose of this application, this application provides the following technical solutions:

[0006] In a first aspect, the present application provides an arc extinguishing medium for a fuse, wherein the arc extinguishing medium comprises vermiculite and quartz sand, wherein the mass ratio of the vermiculite to the quartz sand is (5-8):(12-15).

[0007] In one embodiment, the vermiculite has a particle size of 300 μm to 500 μm.

[0008] In one embodiment, the particle size of the quartz sand is 300 μm to 500 μm.

[0009] In one embodiment, the outer surface of the vermiculite is also coated with a silicone coating layer.

[0010] In one embodiment, the thickness of the silicone resin coating layer is 1 μm to 5 μm.

[0011] In one embodiment, the arc extinguishing medium further comprises asbestos, and the mass ratio of the asbestos to the vermiculite is (0.01-0.2):(0.8-0.99).

[0012] In one embodiment, the arc extinguishing medium further includes mica, and the mass ratio of the mica to the vermiculite is (0.1-0.3):(0.7-0.9).

[0013] In a second aspect, the present application provides a method for preparing an arc extinguishing medium, comprising: cleaning vermiculite to remove metal oxide impurities on the surface of the vermiculite; mixing the vermiculite and quartz sand in a mass ratio to obtain the arc extinguishing medium, wherein the mass ratio of the vermiculite to the quartz sand is (5-8):(12-15).

[0014] In a third aspect, the present application provides a fuse, comprising an insulating shell, a fuse element and the arc-extinguishing medium described in the first aspect, wherein the insulating shell encloses a receiving cavity, and the fuse element and the arc-extinguishing medium are received in the receiving cavity.

[0015] In one embodiment, the fuse further includes a first connecting terminal and a second connecting terminal, the first connecting terminal and the second connecting terminal are arranged at opposite ends of the insulating shell, and the first connecting terminal and the second connecting terminal at least partially extend into the accommodating cavity to be connected to the fuse body.

[0016] In a fourth aspect, the present application provides a method for manufacturing a fuse, comprising: placing a fuse body in a receiving cavity of an insulating shell; filling an arc extinguishing medium into the receiving cavity from a filling port of the insulating shell, and sealing the filling port.

[0017] The arc extinguishing medium provided in the present application is a mixture of quartz sand and vermiculite, which has the following advantages: (1) Vermiculite has high-temperature expansion ability and can weaken the arc energy. When a small fault current occurs, the arc extinguishing medium has a large thermal conductivity, and its volume expands when heated, thereby enhancing the restraint ability on the fuse and increasing the contact area with the arc, thereby weakening the arc energy; (2) Vermiculite expands and exerts shear force on the fuse, which can accelerate the melting of the fuse, and after the melting, the gap of the fuse is enlarged, and the arc column is widened, which is beneficial to weakening the arc starting and arc extinguishing; (3) Quartz sand and vermiculite form a high-density powder, which causes the arc column to increase the pressure on the tube wall and has a buffering and weakening effect. Since the hardness of vermiculite is much smaller than that of quartz sand and alumina ceramic shell, and it has good toughness and ductility due to air absorption and water loss expansion, it can buffer the tube wall pressure; (4) the doped vermiculite has good insulation, flame retardancy, heat insulation and water absorption like quartz sand, which is conducive to weakening the influence of arc and improving its applicability; (5) When disconnecting under low overload, the disconnection speed relying on the thermal effect of the fuse is too slow and cannot protect the circuit in time. Therefore, vermiculite is added to give the fuse a stress effect of plastic deformation after thermal expansion, thereby accelerating the speed of low overload disconnection.

[0018] The fuse provided in the present application has the following advantages by adopting the above-mentioned arc extinguishing medium: (1) The mixed arc extinguishing medium is used to prepare the fuse, which is convenient, economical and efficient, and can suppress the arc to achieve the purpose of safe use; (2) The high-temperature expansion characteristics of the arc extinguishing medium and the thermal change characteristics of the fuse under high voltage and low current are complementary, which can not only solve or weaken the arc influence from the arc ignition characteristics, but also solve the problem that high voltage and low current overload are difficult to fuse; (3) The arc extinguishing medium is low in cost and easy to prepare, which reduces the manufacturing cost of the fuse, and the method is easy to implement and has low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 is a schematic diagram of the dissection of a fuse when it is not working in an embodiment;

[0021] Figure 2 is a schematic diagram of the working state of a fuse according to an embodiment;

[0022] Figure 3 is a flow chart of a method for making an arc extinguishing medium according to an embodiment;

[0023] Figure 4The present invention is a flow chart of a method for manufacturing a fuse according to an embodiment.

[0024] Description of the reference numerals: 1 - first connecting terminal, 2 - second connecting terminal, 3 - insulating housing, 4 - fuse, 5 - vermiculite, 6 - quartz sand. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there can be a central component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there can be a central component at the same time.

[0027] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this application and in the specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this application includes any and all combinations of one or more of the related listed items.

[0028] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0029] The present invention discloses an arc extinguishing medium and a fuse filled with the arc extinguishing medium. Figure 1 and Figure 2 The prepared arc extinguishing medium has the characteristics of high-temperature expansion, good insulation and flame retardant properties, mainly by restraining the fuse 4 and strengthening the contact between the doped medium and the arc, so as to accelerate the melting of the fuse 4 and accelerate the arc extinguishing ability.

[0030] In one embodiment, the present application provides an arc extinguishing medium for a fuse, the arc extinguishing medium is filled in the fuse and contacts the fuse body 4 for insulation and flame retardancy. The arc extinguishing medium includes vermiculite 5 and quartz sand 6, wherein the mass ratio of vermiculite 5 to quartz sand 6 is (5-8):(12-15).

[0031] Specifically, the arc extinguishing medium is based on quartz sand 6 and vermiculite 5 is a doping medium. Vermiculite 5 is a natural, inorganic, non-toxic mineral that expands under high temperature; vermiculite 5 belongs to silicate, and its crystal structure is monoclinic. The doping medium vermiculite 5 also has good insulation, flame retardancy, thermal insulation and other properties, which helps to weaken the impact of the arc and improve its applicability.

[0032] The mass ratio of vermiculite 5 and quartz sand 6 can be 5:12, 5:13, 5:14, 5:15, 6:12, 6:13, 6:14, 6:15, 7:12, 7:13, 7:14, 7:15, 8:12, 8:13, 8:14, 8:15.

[0033] The doped medium vermiculite 5 has the characteristic of high temperature expansion, which increases the contact area between the arc and the insulating flame retardant and other materials in the arc extinguishing medium, widens the melting gap, and effectively weakens the arc energy and accelerates arc extinguishing. At the same time, due to its expansion and hardness characteristics, the restraint force on the fuse 4 is enhanced, causing the fuse 4 to produce plastic deformation, thereby accelerating the melting of the fuse 4 and relieving the pressure of the arc on the tube wall.

[0034] Optionally, in order to make the doping medium in the arc extinguishing medium, the vermiculite 5, be evenly dispersed in the quartz sand 6 matrix to avoid the formation of clusters, etc., the quartz sand 6 and the vermiculite 5 may be processed by ultrasonic dispersion, air blasting, etc.

[0035] Under high voltage and low current, the fuse 4 conducts heat outward greatly, and the doping medium expands due to heat (200-600°C). As the volume of the doping medium expands, the density of the filling body increases, resulting in an increase in the contact area between the arc and the insulating and flame-retardant materials in the filling body, and the arc energy is absorbed to achieve the purpose of accelerating arc extinguishing.

[0036] Optional, but it can be given that when vermiculite expands due to temperature, the expansion volume increases by 20vol% to 30vol%, at which time the pressure in the cavity will increase by about an order of magnitude, which is conducive to applying normal shear stress to the fuse. In addition, the hardness of the expanded vermiculite will decrease, the texture will be soft, and the force on the shell will be very low, and the expansion force will be concentrated on the fuse.

[0037] The arc extinguishing medium provided in the present application is a mixture of quartz sand 6 and vermiculite 5, which has the following advantages: (1) Vermiculite 5 has high-temperature expansion capability and can weaken arc energy. When a small fault current occurs, the arc extinguishing medium has a large heat conductivity, and its volume expands when heated, thereby enhancing its ability to restrain the fuse 4 and increasing its contact area with the arc, thereby weakening the arc energy; (2) Vermiculite 5 expands and exerts a shear force on the fuse 4, which can accelerate the melting of the fuse 4. After the melting, the gap of the fuse 4 is enlarged, and the arc column is widened, which is beneficial to weakening arc starting and arc extinguishing; (3) Quartz sand 6 and vermiculite 5 form a high-density powder, which causes the arc column to increase the pressure on the tube wall and has a buffering and weakening effect. Since the hardness of vermiculite 5 is much smaller than that of quartz sand 6 and alumina ceramic shell, and it has good toughness and ductility due to air absorption and water loss expansion, it can buffer the tube wall pressure; (4) the doped vermiculite 5 has good insulation, flame retardancy, heat insulation and water absorption like quartz sand 6, which is beneficial to weaken the influence of arc and improve its applicability; (5) when disconnecting under low overload, the disconnection speed relying on the thermal action of the fuse is too slow and cannot protect the circuit in time, therefore, the vermiculite 5 is added to give the stress effect of plastic deformation on the fuse after thermal expansion, thereby accelerating the speed of low overload disconnection.

[0038] In one embodiment, the particle size of the vermiculite 5 is 300 μm to 500 μm. Specifically, the particle size of the vermiculite 5 can be 300 μm, 325 μm, 350 μm, 375 μm, 400 μm, 425 μm, 450 μm, 475 μm, or 500 μm.

[0039] When the particle size range of the vermiculite 5 is met, the arc extinguishing medium has good filling property, is not easy to agglomerate, and the expansion of the vermiculite 5 is uniform.

[0040] In one embodiment, the particle size of the quartz sand 6 is 300 μm to 500 μm. Specifically, the particle size of the quartz sand 6 can be 300 μm, 325 μm, 350 μm, 375 μm, 400 μm, 425 μm, 450 μm, 475 μm, or 500 μm.

[0041] When the particle size of the quartz sand 6 is within the above range, the arc extinguishing medium has good filling properties and is not easy to agglomerate, and the quartz sand 6 will not hinder the expansion of the vermiculite 5.

[0042] In one embodiment, the outer surface of the vermiculite 5 is also coated with a silicone coating layer. In order to controllably and selectively adjust the high-temperature expansion characteristics of the doped medium vermiculite 5, the doped medium vermiculite 5 can be surface modified, specifically, a silicone coating layer is provided on the surface of the vermiculite 5. Silicone can achieve temperature insulation for the vermiculite 5. At a lower temperature, the vermiculite 5 will not expand at will, thereby improving the stability of the arc extinguishing medium; at the same time, silicone is also deformable and can expand with the vermiculite 5, so it will not affect the expansion of the vermiculite 5 at a higher temperature.

[0043] In one embodiment, the thickness of the silicone resin coating layer is 1 μm to 5 μm. Specifically, the thickness of the silicone resin coating layer may be 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, or 5 μm.

[0044] The thickness of the silicone coating layer can achieve temperature control and regulation of the vermiculite 5, and can also ensure the expansion characteristics of the vermiculite 5. The silicone coating layer can increase the temperature-expansion action ability of the vermiculite from 200°C to 500°C to 260°C to 520°C, avoiding premature expansion when the vermiculite is connected to the circuit for normal operation, resulting in abnormal disconnection.

[0045] In one embodiment, the surface of the vermiculite 5 and / or the quartz sand 6 is rough. In order to reduce the stratification and unevenness of the mixed filler body caused by transportation vibration, crushing method and dry grinding can be used to increase the surface roughness and enhance the mechanical bite force between particles.

[0046] In one embodiment, the arc extinguishing medium further includes asbestos, and the mass ratio of asbestos to vermiculite is (0.01-0.2):(0.8-0.99). Specifically, the mass ratio of mica to vermiculite can be 0.01:0.99, 0.05:0.95, 0.1:0.9, 0.15:0.85, 0.2:0.8.

[0047] Adding asbestos to the arc extinguishing medium can enhance the heat insulation and insulation properties of the arc extinguishing medium, further weaken the impact of the arc and improve its applicability.

[0048] In one embodiment, the arc extinguishing medium further includes mica, and the mass ratio of mica to vermiculite is (0.1-0.3):(0.7-0.9). Specifically, the mass ratio of mica to vermiculite can be 0.1:0.9, 0.15:0.85, 0.2:0.8, 0.25:0.75, 0.3:0.7.

[0049] Since mica is a layered material, adding mica to the arc extinguishing medium can reduce the friction between the materials, improve the expansion of the vermiculite 5, and make the expansion action point of the vermiculite 5 obvious.

[0050] In one embodiment, the present application also provides a method for making an arc extinguishing medium, please refer to Figure 3 , including the following steps:

[0051] Step S10 , cleaning the vermiculite 5 to remove metal oxide impurities on the surface of the vermiculite 5 .

[0052] Step S20, mixing vermiculite 5 and quartz sand 6 according to a mass ratio to obtain an arc extinguishing medium, wherein the mass ratio of vermiculite 5 to quartz sand 6 is (5-8):(12-15).

[0053] Specifically, in step S10, the vermiculite 5 is cleaned to remove metal oxide impurities on the surface of the vermiculite 5, including: selecting vermiculite 5 particles with a mesh size of about 30 to 40 (300 μm to 500 μm); cleaning with 1 mol / L copper chloride solution, 0.1 mol / L dilute hydrochloric acid solution, etc., to remove surface metal oxide impurities and weaken their cation exchange capacity, thereby preventing them from affecting the flow capacity of the fuse 4 and agglomeration of particles and causing abnormal fusing. Then wash with water three times, dry at 80°C, and set aside.

[0054] Optionally, in step S20, the vermiculite 5 and the quartz sand 6 are mixed according to a mass ratio, including: selecting quartz sand 6 with a mesh size of about 30 to 40 (300 μm to 500 μm), mixing the quartz sand 6 with the vermiculite 5 in the above weight ratio, and using ultrasonic dispersion to ensure that the doping medium is evenly dispersed in the quartz sand 6. Then drying at 80°C, standing, and standby.

[0055] In one implementation, the present application also provides a fuse, please refer to Figure 1 and Figure 2 The fuse includes an insulating shell 3, a fuse body 4 and an arc extinguishing medium. The insulating shell 3 encloses a receiving cavity, and the fuse body 4 and the arc extinguishing medium are received in the receiving cavity.

[0056] Specifically, the fuse also includes baffles on both sides, the shell can be in the shape of a rectangular sleeve, two baffles are respectively arranged at the opposite ends of the shell, and the baffles on both sides and the shell together enclose a receiving cavity. The fuse 4 and the arc extinguishing medium are both accommodated in the receiving cavity enclosed by the shell.

[0057] Optionally, the shell and the baffle are connected by fixing screws, and a proper amount of fastening glue is applied to the screw holes connecting the shell and the baffle.

[0058] The arc extinguishing medium is provided by the above-mentioned embodiment, which will not be described in detail here. The fuse 4 can have any number of fuse effect points connected in series, and any number of fuses 4 can be connected in parallel in the fuse. The fuse 4 can be a sheet or plate structure of silver or silver-copper alloy.

[0059] Since the hardness of vermiculite 5 is about 1 / 5 of that of quartz sand 6 and insulating tube, and it has relatively good toughness and ductility, its expansion helps to relieve the high tube wall pressure caused by high density and protect the safe operation of the device. In addition, due to the large heat conduction to the outside of the fuse 4 under high voltage and low current, the heat accumulation is insufficient, resulting in a slow melting time of the fuse 4. When the volume of the doping medium expands, the constraint force on the fuse 4 is enhanced, which can be regarded as the shear force applied to the fuse 4 in the Z-axis direction. This effect will cause plastic deformation of the fuse 4 and accelerate the melting of the fuse 4. And after melting, the constraint force of the expanded doping medium on the fuse 4 still exists, and the shear force in this direction will further widen the melting gap and the arc column, thereby effectively weakening the arc energy and accelerating arc extinguishing.

[0060] The fuse provided in the present application has the following advantages by adopting the above-mentioned arc extinguishing medium: (1) The mixed arc extinguishing medium is used to prepare the fuse, which is convenient, economical and efficient, and can suppress the arc to achieve the purpose of safe use; (2) The high-temperature expansion characteristics of the arc extinguishing medium and the thermal change characteristics of the fuse 4 under high voltage and low current are complementary, which can not only solve or weaken the arc influence from the arc ignition characteristics, but also solve the problem that high voltage and low current overload are difficult to fuse; (3) The arc extinguishing medium is low in cost and easy to prepare, which reduces the manufacturing cost of the fuse, and the method is easy to implement and has low production cost.

[0061] In one implementation, please refer to Figure 1 and Figure 2 The fuse also includes a first connecting terminal 1 and a second connecting terminal 2, which are arranged at two opposite ends of the insulating shell 3, and the first connecting terminal 1 and the second connecting terminal 2 at least partially extend into the receiving cavity and are connected to the fuse body 4.

[0062] Specifically, the first connection terminal 1 and the second connection terminal 2 are connected to the corresponding baffles, and the first connection terminal 1 and the second connection terminal 2 at least partially pass through the baffle and extend into the receiving cavity to connect with the fuse 4. The connection terminal has good electrical and thermal conductivity, corrosion resistance, and is easy to weld with the fuse 4. The material can be brass or pure copper. A proper amount of fastening glue can be applied to the screw hole between the connection terminal and the baffle.

[0063] In one embodiment, the present application also provides a method for manufacturing a fuse, please refer to Figure 4 ,include:

[0064] Step S30 , placing the fuse 4 in the receiving cavity of the insulating housing 3 .

[0065] Step S40, filling the arc extinguishing medium into the receiving cavity from the filling port of the insulating housing 3, and sealing the filling port.

[0066] Specifically, a conventional fuse 4 with a fuse group is prepared; the two ends of the fuse 4 are electrically connected to the first connection terminal 1 and the second connection terminal 2 respectively; the first connection terminal 1 is connected to the baffle on one side by using a fixing screw, and a proper amount of fastening glue is applied to the screw hole; the baffle is connected to the ceramic shell by using a fixing screw, and a proper amount of fastening glue is applied to the screw hole; the second connection terminal 2 is connected to the baffle on the other side by using a fixing screw, and a proper amount of fastening glue is applied to the screw hole.

[0067] Pour the prepared arc extinguishing medium into the assembled fuse from the sand filling port, seal it, and bake it in an 80℃ oven for 2 hours to solidify the fastener in the screw hole. After filling, the drying temperature shall not exceed 200℃.

[0068] The technical solution of the present invention is described in detail below through specific embodiments.

[0069] Example 1

[0070] This embodiment provides a fuse, including an arc extinguishing medium, wherein the arc extinguishing medium includes quartz sand and vermiculite (13.5:6.5). The manufacturing method is as follows:

[0071] 1) Select vermiculite particles with a particle size of about 400 μm, and wash them with 1 mol / L copper chloride solution, 0.1 mol / L dilute hydrochloric acid solution, etc. to remove surface metal oxide impurities and weaken the cation exchange capacity of vermiculite, etc., to prevent it from affecting the current capacity of the fuse and agglomeration of particles. Then wash with water three times, dry at 80°C, and set aside.

[0072] 2) Select quartz sand with a particle size of about 400 μm, mix the quartz sand and the dopant in the above weight ratio, use ultrasonic dispersion to ensure that the doping medium is evenly dispersed in the quartz sand, dry at 80°C, let stand, and set aside.

[0073] 3) Preparing a conventional fuse having a fuse group;

[0074] 4) Electrically connecting two ends of the fuse to the first connection terminal and the second connection terminal respectively;

[0075] 5) Connect the first connection terminal to one side baffle with fixing screws, and apply appropriate amount of fastening glue to the screw holes;

[0076] 6) Connect the baffle to the ceramic shell with fixing screws, and apply appropriate amount of fastening glue to the screw holes;

[0077] 7) Connect the second connection terminal to the other side baffle with fixing screws, and apply appropriate amount of fastening glue to the screw holes;

[0078] 8) The assembled fuse is filled with the prepared doping filler from the sand filling port, sealed, and placed in an 80° C. oven for 2 hours to solidify the fastening glue in the screw hole.

[0079] Example 2

[0080] This embodiment provides a fuse, including an arc extinguishing medium, wherein the arc extinguishing medium includes quartz sand and vermiculite (12:8). The manufacturing method is as described in Example 1.

[0081] Example 3

[0082] This embodiment provides a fuse, including an arc extinguishing medium, wherein the arc extinguishing medium includes quartz sand and vermiculite (15:5). The manufacturing method is as described in Example 1.

[0083] Example 4

[0084] This embodiment provides a fuse, including an arc extinguishing medium, wherein the arc extinguishing medium includes quartz sand and vermiculite (13.5:6.5). The particle size of the vermiculite and quartz sand is 500 μm. The manufacturing method is as described in Example 1.

[0085] Example 5

[0086] This embodiment provides a fuse, including an arc extinguishing medium, the arc extinguishing medium includes quartz sand and vermiculite (13.5:6.5). The vermiculite surface has a silicone resin coating layer with a thickness of 1.2 μm to 3.3 μm. The manufacturing method is referred to in Example 1.

[0087] Example 6

[0088] This embodiment provides a fuse, including an arc extinguishing medium, wherein the arc extinguishing medium includes quartz sand and vermiculite (13.5:6.5). The surface roughness of the vermiculite and quartz sand is 0.8 μm to 1.6 μm. The manufacturing method is referred to in Example 1.

[0089] Example 7

[0090] This embodiment provides a fuse, including an arc extinguishing medium, wherein the arc extinguishing medium includes quartz sand and vermiculite (13.5:6.5). The arc extinguishing medium also includes asbestos and mica, wherein the mass ratio of mica to vermiculite can be 0.1:0.9, and the mass ratio of mica to vermiculite can be 0.25:0.75. The manufacturing method is referred to in Example 1.

[0091] Comparative Example 1

[0092] This embodiment provides a fuse, including an arc extinguishing medium, wherein the arc extinguishing medium includes quartz sand. The manufacturing method is as described in Embodiment 1.

[0093] Comparative Example 2

[0094] This embodiment provides a fuse, including an arc extinguishing medium, wherein the arc extinguishing medium includes quartz sand and vermiculite (10:10). The manufacturing method is similar to that of embodiment 1.

[0095] The fuses provided in the above-mentioned embodiments 1-7 and comparative examples 1-2 were tested, and the test items included breaking capacity, whether it could be broken safely, and time. Please refer to Table 1 for specific test results.

[0096] Table 1

[0097] Breaking capacity Safe disconnection Break time Example 1 2.5In yes About 2s Example 2 2.5In yes About 1s Example 3 2.5In yes About 2s Example 4 2.5In yes About 1s Example 5 2.5In yes About 1s Example 6 2.5In yes About 1s Example 7 2.5In yes Less than 1s Comparative Example 1 2.5In no / Comparative Example 2 2.5In yes About 6s

[0098] It can be seen from the test results of Examples 1-7 and Comparative Examples 1-2 in Table 1 that, under the same breaking capacity, the fuses provided by Examples 1-7 can all be safely broken, and the breaking time is fast (all within 3 seconds), which illustrates the superiority of the arc extinguishing medium provided by the present application.

[0099] It can be seen from the test results of Examples 1-3 in Table 1 that the ratio of quartz sand to vermiculite in the arc extinguishing medium has an influence on the breaking time, and it is easy to see that as the content of vermiculite decreases, the segmentation time becomes longer.

[0100] It can be seen from the test results of Example 1 and Example 4 in Table 1 that the particle size of vermiculite and quartz sand also affects the breaking time of the arc extinguishing medium, and the breaking time becomes shorter as the particle size becomes larger.

[0101] It can be seen from the test results of Example 1 and Example 5 in Table 1 that whether or not a coating layer is provided on the surface of vermiculite also has an impact on the breaking time of the arc extinguishing medium, and when a coating layer is provided on the vermiculite, the breaking time becomes shorter.

[0102] It can be seen from the test results of Example 1 and Example 6 in Table 1 that the surface roughness of vermiculite and quartz sand also affects the breaking time of the arc extinguishing medium, and the breaking time becomes shorter as the roughness increases.

[0103] It can be seen from the test results of Example 1 and Example 7 in Table 1 that, on the basis of the combination of vermiculite and quartz sand, by adding mica and asbestos, the breaking time of the arc extinguishing medium can be further shortened.

[0104] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship of terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" are based on the orientation or positional relationship of the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0105] What is disclosed above is only a preferred embodiment of the present application, and it certainly cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiment and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. An arc extinguishing medium for a fuse, characterized in that: The arc extinguishing medium includes vermiculite and quartz sand, wherein the mass ratio of the vermiculite to the quartz sand is (5-8):(12-15).

2. The arc extinguishing medium according to claim 1, characterized in that: The particle size of the vermiculite is 300 μm to 500 μm.

3. The arc extinguishing medium according to claim 1, characterized in that: The particle size of the quartz sand is 300 μm to 500 μm.

4. The arc extinguishing medium according to claim 1, characterized in that: The outer surface of the vermiculite is also coated with a silicone resin coating layer.

5. The arc extinguishing medium according to claim 4, characterized in that: The thickness of the silicone resin coating layer is 1 μm to 5 μm.

6. The arc extinguishing medium according to claim 1, characterized in that: The arc extinguishing medium also includes asbestos, and the mass ratio of the asbestos to the vermiculite is (0.01-0.2):(0.8-0.99).

7. The arc extinguishing medium according to claim 1, characterized in that: The arc extinguishing medium further comprises mica, and the mass ratio of the mica to the vermiculite is (0.1-0.3):(0.7-0.9).

8. A method for producing an arc extinguishing medium, characterized in that: include: Washing the vermiculite to remove metal oxide impurities on the surface of the vermiculite; The vermiculite and quartz sand are mixed in a mass ratio to obtain the arc extinguishing medium, and the mass ratio of the vermiculite to the quartz sand is (5-8):(12-15).

9. A fuse, characterized in that: The fuse comprises an insulating shell, a fuse element and the arc-extinguishing medium according to any one of claims 1 to 8, the insulating shell encloses a receiving cavity, and the fuse element and the arc-extinguishing medium are received in the receiving cavity.

10. The fuse according to claim 9, characterized in that: The fuse further includes a first connecting terminal and a second connecting terminal, wherein the first connecting terminal and the second connecting terminal are arranged at two opposite ends of the insulating housing, and the first connecting terminal and the second connecting terminal at least partially extend into the receiving cavity to be connected to the fuse body.

11. A method for manufacturing a fuse, characterized in that: include: Placing the fuse in the receiving cavity of the insulating housing; The arc extinguishing medium as described in any one of claims 1 to 8 is filled into the receiving cavity from the filling port of the insulating shell, and the filling port is sealed.

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