Fuse with magnetic arc blowing function and preparation method thereof

Abstract

The present invention discloses a fuse with a magnetic arc blowing function and a preparation method thereof, wherein the steps of the preparation method include: (1) providing an alloy melt, wherein at least two wide sections are formed on the alloy melt, and a narrow section is formed between two adjacent widths, wherein the cross-sectional area of ​​the narrow section is smaller than the cross-sectional area of ​​the wide section; (2) printing a magnetic composite slurry on the surface of the wide section to form at least two magnetic composite material layers, wherein the magnetic composite slurry includes hard magnetic magnetic powder; (3) magnetizing the magnetic composite material layer so that two adjacent magnetic composite material layers generate a magnetic field in the same direction in the narrow section, wherein the angle between the direction of the magnetic field and the length direction of the alloy melt is an acute angle or a right angle; (4) placing the alloy melt inside a shell, and then adding quartz sand into the shell. The fuse of the present invention includes a magnetic composite material layer and quartz sand, wherein the magnetic composite material layer has a magnetic arc blowing function, and the quartz sand can effectively separate the arc, thereby having a better arc extinguishing effect.

Description

Technical Field

[0001] The invention belongs to the technical field of fuse preparation, and in particular relates to a fuse with a magnetic arc blowing function and a preparation method thereof. Background Art

[0002] Fuses are widely used in high and low voltage power distribution systems, control systems and electrical equipment to protect against short circuits and overload currents. The arc extinguishing ability of a fuse is one of the important factors affecting its breaking capacity and safety. Traditional fuses usually fill quartz sand into the fuse. When the alloy melt of the fuse melts and an arc is generated, the quartz sand can separate the arc, absorb metal vapor, and physically cool the arc, thereby playing a role in arc suppression and arc extinguishing. Although quartz sand has certain arc suppression and arc extinguishing capabilities and is low in cost, its function is relatively single, and arc extinguishing materials or methods with a single function often find it difficult to achieve the ideal arc suppression and arc extinguishing effect. At the same time, since there is an upper limit to the filling amount of quartz sand, its ability to absorb metal vapor and cool the arc is also limited.

[0003] Magnetic field arc blowing technology can significantly shorten the arc burning time and improve the breaking capacity of fuses by generating a magnetic field to guide and accelerate the extinction of the arc. It is also widely used in various electrical equipment and electronic devices. At present, the magnetic field arc blowing method mostly uses accessories such as energized coils or permanent magnets to provide the magnetic field. However, when such accessories are applied to fuses, there are certain requirements for their design and installation, and other auxiliary accessories such as insulating partitions are usually required to be installed, which makes the device preparation process complicated and cumbersome while increasing the manufacturing cost. In addition, due to space and volume limitations, such accessories are also difficult to meet the needs of the increasing miniaturization and miniaturization of electronic components in terms of size.

[0004] Therefore, there is an urgent need for a fuse with a magnetic arc blowing function and a preparation method thereof to solve the deficiencies of the prior art. Summary of the invention

[0005] In view of the above problems, an object of the present invention is to provide a fuse with a magnetic arc blowing function and a preparation method thereof. The preparation process of the method is simple and the cost is low, and the prepared fuse has a good arc extinguishing effect.

[0006] To achieve the above objectives, the present invention provides a method for preparing a fuse with a magnetic arc blowing function in a first aspect, comprising the following steps:

[0007] (1) providing an alloy melt, wherein the alloy melt has at least two wide sections along its length direction, a narrow section is formed between two adjacent widths, and a cross-sectional area of ​​the narrow section is smaller than a cross-sectional area of ​​the wide section;

[0008] (2) printing a magnetic composite slurry on the surface of the wide section, and then curing it to form at least two magnetic composite material layers, wherein the magnetic composite slurry includes hard magnetic powder;

[0009] (3) magnetizing the magnetic composite material layer so that two adjacent magnetic composite material layers generate magnetic fields in the same direction in the narrow section, and the angle between the magnetic field direction and the length direction of the alloy melt is an acute angle or a right angle;

[0010] (4) The alloy melt obtained after step (3) is placed inside the shell, and quartz sand is then added into the shell.

[0011] Compared with the prior art, the present invention prints magnetic composite slurry on the wide section surface of the alloy melt, and obtains a magnetic composite material layer after solidification. The magnetic composite material layer can be firmly attached to the alloy melt surface of the fuse, which can improve the stability of the fuse and facilitate arc extinguishing. Then the magnetic composite material layer is magnetized so that the adjacent magnetic composite material layers generate a magnetic field in the same direction in the narrow section. The angle between the direction of the magnetic field and the length direction of the alloy melt is an acute angle or a right angle. When the narrow section of the alloy melt is melted and disconnected, the charged particles in the arc are subjected to the Lorentz magnetic force in the magnetic field, causing the arc to be elongated, changing the arc volt-ampere characteristics, thereby accelerating the arc extinguishing; in addition, the elongated arc will also quickly diffuse into the quartz sand, and the quartz sand can effectively separate the arc, absorb metal vapor and cool the arc, thereby improving the arc extinguishing effect. In particular, the hard magnetic powder in the magnetic composite material layer can provide a high-intensity and lasting magnetic field, which is conducive to further improving the arc extinguishing effect and its arc extinguishing stability. Therefore, the preparation method of the fuse with magnetic arc blowing function provided by the present invention has a simple preparation process and low cost, and the prepared fuse has a good arc extinguishing effect.

[0012] Furthermore, the curing of the present invention includes curing at room temperature for 2 to 48 hours.

[0013] Furthermore, the magnetic composite material layer of the present invention is in the shape of a cuboid or a cylinder.

[0014] Furthermore, the magnetization treatment of the present invention includes magnetization at a magnetic field strength of 0.5 to 5 T for 0.5 to 5 h.

[0015] Furthermore, after the magnetic composite material layer is magnetized in the present invention, the magnetic composite material layer has an N pole and an S pole along the width or height direction of the alloy melt, and the direction of the magnetic field is from the N pole to the S pole.

[0016] Furthermore, the hard magnetic powder of the present invention includes at least one of neodymium iron boron magnetic powder, neodymium iron nitrogen magnetic powder, aluminum nickel cobalt magnetic powder, ferrite magnetic powder, chromium oxide magnetic powder and samarium cobalt magnetic powder.

[0017] Furthermore, the raw materials for preparing the magnetic composite slurry of the present invention include, by mass, 30 to 60 parts of epoxy resin, 5 to 30 parts of epoxy resin curing agent, 10 to 30 parts of SiO2 particles, 5 to 50 parts of hard magnetic powder and 5 to 15 parts of flame retardant.

[0018] Furthermore, the SiO 2 The particle size of the particles is 40 to 250 μm, the particle size of the quartz sand is 0.5 to 4 mm, and the particle size of the hard magnetic powder is 5 to 150 μm.

[0019] Furthermore, the epoxy resin of the present invention includes at least one of bisphenol A epoxy resin, butanediol bisglycidyl ether epoxy resin and epoxidized polybutadiene resin.

[0020] Further, the epoxy resin curing agent of the present invention comprises at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, m-phenylenediamine, xylylenediamine, triethanolamine, 4,4'-diaminodiphenylmethane, benzyldimethylamine, maleic anhydride, pyromellitic anhydride and tung oil modified anhydride.

[0021] Furthermore, the flame retardant of the present invention is at least one of aluminum hydroxide, calcium aluminate, ammonium polyphosphate, perchlorobiphenyl, nickel monoxide, antimony trioxide, halides and tricresyl phosphate.

[0022] To achieve the above objectives, the second aspect of the present invention further provides a fuse with a magnetic arc blowing function, which is manufactured by the above-mentioned method for manufacturing a fuse with a magnetic arc blowing function.

[0023] Compared with the prior art, the fuse of the present invention utilizes the magnetic composite material layer on the surface of the alloy melt to provide a magnetic arc blowing effect. Therefore, the fuse of the present invention not only has a better arc extinguishing effect, but also does not require the installation of other auxiliary accessories so that the fuse can meet the requirements of the increasing miniaturization and miniaturization of electronic components in size. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a process flow chart of a method for preparing a fuse with a magnetic arc blowing function.

[0025] Figure 2 It is a schematic diagram of the structure of the magnetic composite material layer of the present invention.

[0026] Figure 3 It is a schematic structural diagram of the magnetic composite material layer after magnetization treatment of the present invention.

[0027] Figure 4 Another schematic diagram of the structure of the magnetic composite material layer after magnetization treatment of the present invention.

[0028] Figure 5It is a schematic diagram of the magnetic field structure of the magnetic composite material layer after magnetization treatment of the present invention.

[0029] Figure 6 Another schematic diagram of the magnetic field structure of the magnetic composite material layer after magnetization treatment of the present invention.

[0030] Figure 7 This is a fusing waveform diagram of the fuse with magnetic arc blowing function made in Example 1 of the present invention. DETAILED DESCRIPTION

[0031] In order to better illustrate the purpose, technical solution and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments and drawings. It should be noted that the following implementation method is a further explanation of the present invention and should not be used as a limitation of the present invention.

[0032] Please see Figure 1 The present invention provides a method for preparing a fuse with a magnetic arc blowing function, comprising steps S1 to S4:

[0033] In step S1, a molten alloy 11 is provided, and the molten alloy 11 is formed with at least two wide sections 111 along its length direction X, and a narrow section 112 is formed between two adjacent wide sections 111, and the cross-sectional area of ​​the narrow section 112 is smaller than the cross-sectional area of ​​the wide section 111. When current passes through the molten alloy 11, under the action of overload current, the temperature at the narrow section 112 of the molten alloy 11 rises sharply, and the alloy 11 is melted, thereby generating an arc at the fracture.

[0034] Wherein, step S2 includes printing magnetic composite slurry on the surface of wide section 111, and then curing to form at least two magnetic composite material layers 12. Specifically, it includes printing the magnetic composite slurry on the surface of alloy melt 11 by steel plate printing or screen printing. Specifically, curing includes curing at room temperature for 2 to 48 hours, and room temperature generally refers to 10°C to 30°C. The curing time can be 2h, 4h, 6h, 8h, 10h, 12h, 16h, 20h, 24h, 28h, 32h, 35h, 40h, 44h, 46h, 48h. The curing time is preferably 12 to 36h, and more preferably 18 to 26h. Step (2) can enable the magnetic composite material layer 12 to be firmly attached to the surface of alloy melt 11 of fuse 100, which can improve the stability of fuse 100 and facilitate arc extinguishing.

[0035] In step S3, the magnetic composite material layer 12 is magnetized so that two adjacent magnetic composite material layers 12 generate magnetic fields in the same direction in the narrow section 112, and the angle α between the magnetic field direction B and the length direction X of the alloy melt is an acute angle or a right angle. Specifically, the magnetization treatment can be performed by a magnetization device (such as a strong electromagnet, a magnetizer, etc.), and the magnetization treatment includes magnetization at a magnetic field strength of 0.5 to 5T for 0.5 to 5h; specifically, the magnetic field strength can be but not limited to 0.5T, 1.2T, 1.5T, 1.8T, 2.2T, 2.5T, 2.8T, 3.2T, 3.6T, 4T, 4.4T, 5T, and the magnetization time can be but not limited to 0.5h, 1.3h, 1.6h, 1.8h, 2h, 2.2h, 2.6h, 3h, 3.2h, 3.5h, 3.9h, 4.2h, 4.6h, 5h. The magnetic field strength is preferably 1-2 T, more preferably 1.3-1.8 T; the magnetization time is preferably 2-4 h, more preferably 2.5-3.5 h. Step (3) allows the charged particles in the arc to be subjected to the Lorentz magnetic force in the magnetic field, causing the arc to be elongated, changing the arc volt-ampere characteristics, thereby accelerating the arc extinction.

[0036] Among them, step S4 includes placing the alloy melt 11 obtained after step S3 inside the housing 13, and then adding quartz sand 14 into the housing 13 to obtain a fuse 100 with a magnetic arc blowing function. Specifically, the particle size of the quartz sand is 0.5-4 mm; the particle size of the quartz sand can be but is not limited to 0.5 mm, 0.8 mm, 1.2 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4 mm. The particle size of the quartz sand is preferably 0.5-2 mm, and more preferably 0.5-1 mm.

[0037] Furthermore, in step (2) of the present invention, the magnetic composite slurry is formed on the surface of the wide section 111 of the alloy melt 11 by printing, which makes it possible to design and change the shape of the magnetic composite material layer 12 according to actual needs, such as Figure 2 The cylinder shown or Figure 3 The distribution of the magnetic composite material layer 12 on the alloy melt 11 can also be designed and changed according to actual needs, such as using a steel plate with a high mesh density to form a rectangular parallelepiped. Figure 2 The magnetic composite material layer 12 shown can be formed by single-sided printing. Figure 3 The magnetic composite material layer 12 shown in the figure can be printed on the upper and lower surfaces to form Figure 4 As shown in the magnetic composite material layer 12 , the magnetic composite slurry is formed on the surface of the wide section 111 of the alloy melt 11 by printing, which undoubtedly improves the practical value and application range of the fuse 100 .

[0038] Furthermore, after the present invention magnetizes the magnetic composite material layer 12, the magnetic composite material layer 12 has an N pole and an S pole that repels the N pole. Specifically, before the magnetization treatment, the relative position of the N pole and the S pole can be adjusted by adjusting the position of the magnetization device to obtain different magnetic field directions. Specifically, Figure 5 As shown, the magnetic composite material layer 12 may have an N pole and an S pole along the width direction Y of the alloy melt 11, and the direction of the magnetic field is from the N pole to the S pole. In addition, the magnetic composite material layer may also have an N pole and an S pole along the height direction Z of the alloy melt, and the direction of the magnetic field is from the N pole to the S pole (such as Figure 6 Furthermore, Figure 5-6 The angles between the magnetic field direction B and the alloy melt length direction X are both right angles, that is, the magnetic field direction and the arc direction are perpendicular. According to the Lorentz force formula, the charged particles in the arc will be subjected to the maximum Lorentz force, thereby further enhancing the arc drawing effect. Therefore, the angle α between the magnetic field direction B and the alloy melt length direction X of the present invention is preferably a right angle.

[0039] Furthermore, the raw materials for preparing the magnetic composite slurry used in step (2) of the present invention include, by weight, 30 to 60 parts of epoxy resin, 5 to 30 parts of epoxy resin curing agent, 10 to 30 parts of SiO 2 particles, 5 to 50 parts of hard magnetic powder and 5 to 15 parts of flame retardant. Specifically, the epoxy resin can be but not limited to 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts; the epoxy resin curing agent can be but not limited to 5 parts, 8 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts; SiO 2 The particles can be, but are not limited to, 10, 14, 15, 20, 25, 30 parts; the hard magnetic powder can be, but are not limited to, 5, 8, 10, 15, 20, 25, 30, 35, 40, 45, 50 parts. The flame retardant can be, but are not limited to, 5, 8, 10, 12, 15 parts.

[0040] Furthermore, the SiO 2 The particle size is 40 to 250 μm, such as SiO 2 The particle size of the particles may be, but is not limited to, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 190 μm, 210 μm, 230 μm, and 250 μm. SiO 2 The particle size of the particles is preferably 40 to 180 μm, more preferably 40 to 50 μm.

[0041] Furthermore, the particle size of the hard magnetic powder of the present invention is 5 to 150 μm, such as the particle size of the hard magnetic powder can be but not limited to 5 μm, 10 μm, 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 150 μm. The particle size of the hard magnetic powder is preferably 10 to 90 μm, more preferably 30 to 70 μm. Compared with soft magnetic powder, hard magnetic powder can provide a stronger and more durable magnetic field, which is not only conducive to improving the magnetic field arc blowing ability of the magnetic composite material layer, but also conducive to maintaining the long-term stability of the performance of the magnetic composite material layer.

[0042] Furthermore, the preparation of the magnetic composite slurry in step (2) of the present invention comprises: mixing the epoxy resin, epoxy resin curing agent, hard magnetic powder, SiO 2 The particles and the flame retardant are mixed and stirred at room temperature. After the stirring is completed, a degassing machine is used for degassing. The stirring time is 2 to 30 minutes, preferably 5 to 15 minutes, and more preferably 8 to 10 minutes. Specifically, the degassing machine is used for degassing, and the rotation speed is 500 to 3000 rpm, preferably 800 to 2000 rpm, and more preferably 1000 to 1500 rpm. The epoxy resin is used as a carrier, and the hard magnetic powder, SiO 2 The particles and flame retardant are uniformly dispersed in the epoxy resin. After the magnetic powder particles dispersed in the epoxy resin are magnetized, the internal magnetic domains have a consistent orientation, so that the magnetic composite material layer shows magnetism to the outside. 2 The particles act as a thixotropic agent when the magnetic composite slurry is printed, and also help to improve the mechanical strength and crack resistance of the magnetic composite material layer; the flame retardant helps to prevent the magnetic composite material layer from catching fire at high temperatures.

[0043] The following is a further description of the preparation method and effect of the fuse with magnetic arc blowing function of the present invention in combination with specific examples and comparative examples. The bisphenol A epoxy resin E-51, triethylenetetramine, SiO 2 Particles, NdFeB magnetic powder (NdFeB), Al(OH) 3 , magnesium-zinc ferrite and quartz sand are all commercially available.

[0044] The magnetic composite slurry used in Examples 1 to 5 is prepared by raw materials including 40 parts of bisphenol A epoxy resin E-51, 5 parts of triethylenetetramine, 20 parts of SiO 2 Particles, 20 parts of NdFeB magnetic powder and 15 parts of Al(OH) 3 , SiO 2The particle size of the particles is 40-50 μm, and the particle size of the NdFeB magnetic powder is about 30 μm. Specifically, the steps for preparing the magnetic composite slurry used in Examples 1 to 5 include: (1) mixing bisphenol A epoxy resin E-51, triethylenetetramine, SiO 2 Particles, NdFeB magnetic powder and Al(OH) 3 The mixture was stirred at room temperature for 10 min to obtain a slurry; (2) the slurry was degassed using a degassing machine at 1000 rpm for 2 min.

[0045] Example 1

[0046] This embodiment provides a method for preparing a fuse with a magnetic arc blowing function, comprising the following steps:

[0047] (1) providing an alloy melt, wherein the alloy melt has five wide sections along its length direction, a narrow section is formed between two adjacent widths, and a cross-sectional area of ​​the narrow section is smaller than a cross-sectional area of ​​the wide section;

[0048] (2) Print the magnetic composite slurry on the upper surface of the five wide sections and then cure it at room temperature for 24 hours to form a Figure 3 The rectangular parallelepiped magnetic composite material layer shown;

[0049] (3) a strong electromagnet with a magnetic field strength of 1.5 T is used to magnetize the magnetic composite material layer for 3 hours, wherein the magnetic composite material layer has an N pole and an S pole along the width direction of the alloy melt, the direction of the magnetic field is from the N pole to the S pole, and the angle between the magnetic field direction and the length direction of the alloy melt is a right angle;

[0050] (4) The alloy melt obtained after step (3) is placed inside the shell, and quartz sand with a particle size of 0.5 to 1 mm is added into the shell.

[0051] Example 2

[0052] This embodiment provides a method for preparing a fuse with a magnetic arc blowing function, comprising the following steps:

[0053] (1) providing an alloy melt, wherein the alloy melt has five wide sections along its length direction, a narrow section is formed between two adjacent widths, and a cross-sectional area of ​​the narrow section is smaller than a cross-sectional area of ​​the wide section;

[0054] (2) Print the magnetic composite slurry on the upper surface of the five wide sections and then cure it at room temperature for 28 hours to form a Figure 3 The rectangular parallelepiped magnetic composite material layer shown;

[0055] (3) using a strong electromagnet with a magnetic field strength of 1.8 T to magnetize the magnetic composite material layer for 4 hours, wherein the magnetic composite material layer has an N pole and an S pole along the width direction of the alloy melt, the direction of the magnetic field is from the N pole to the S pole, and the angle between the magnetic field direction and the length direction of the alloy melt is a right angle;

[0056] (4) The alloy melt obtained after step (3) is placed inside the shell, and quartz sand with a particle size of 0.5 to 1 mm is added into the shell.

[0057] Example 3

[0058] The preparation method of the fuse with magnetic arc blowing function in Example 3 is basically the same as that in Example 1. The difference between Example 3 and Example 1 is that in step (3), the magnetic composite material layer has an N pole and an S pole along the height direction of the alloy melt.

[0059] Example 4

[0060] The preparation method of the fuse with magnetic arc blowing function in Example 4 is basically the same as that in Example 1. The difference between Example 4 and Example 1 is that in step (2), the magnetic composite slurry is printed on the upper and lower surfaces of the five wide sections, and then cured at room temperature for 28 hours to form a Figure 4 The rectangular parallelepiped magnetic composite material layer shown.

[0061] Example 5

[0062] The preparation method of the fuse with magnetic arc blowing function in Example 5 is basically the same as that in Example 1. The difference between Example 5 and Example 1 is that in step (2), the curing is performed at room temperature for 24 hours to form a Figure 2 The cylindrical magnetic composite material layer shown.

[0063] Comparative Example 1

[0064] The preparation method of the fuse with magnetic arc blowing function of Comparative Example 1 is basically the same as that of Example 1. The difference between Comparative Example 1 and Example 1 is that step (2) and step (3) are removed.

[0065] Comparative Example 2

[0066] The preparation method of the fuse with magnetic arc blowing function in Comparative Example 2 is basically the same as that in Example 1. The difference between Comparative Example 2 and Example 1 is that the magnetic composite slurry in step (2) includes 40 parts of bisphenol A epoxy resin E-51, 5 parts of triethylenetetramine, 20 parts of SiO 2 Particles, 20 parts of soft magnetic magnesium zinc ferrite powder and 15 parts of Al(OH) 3 ; The preparation steps of the magnetic composite slurry are exactly the same as those in Example 1.

[0067] The arc suppression performance test was performed on the fuses of Examples 1 to 5 and Comparative Examples 1 to 2. The test instruments were a short circuit test platform (DL10KV-100), a megohmmeter (AR3127), a DC programmable power supply (IT6932A) and a 6.5-digit multimeter (34401A); the test environment temperature was 20.5°C and the humidity was 46%RH. The arc suppression performance test results of the fuses of Examples 1 to 5 and Comparative Examples 1 to 2 are shown in Table 1; the fuse waveform of the fuse with magnetic arc blowing function prepared in Example 1 is shown in Table 1. Figure 7 shown.

[0068] Table 1 Arc suppression performance test results of fuses

[0069] Group Arcing time(ms) Example 1 13.2 Example 2 13.6 Example 3 11.6 Example 4 7.8 Example 5 9.2 Comparative Example 1 21.6 Comparative Example 2 18.9

[0070] It can be seen from Table 1 that the arc suppression performance of the fuse of Example 1 is better than that of Comparative Example 1. This is because the arc extinguishing system in the fuse prepared by the preparation method of the present invention is composed of a magnetic composite material layer and quartz sand, wherein the magnetic composite material layer has a magnetic arc blowing effect. When the alloy melt of the fuse melts and disconnects to generate an arc, it can stretch the arc, thereby accelerating the extinction of the arc; in addition, the elongated arc will also quickly diffuse into the quartz sand, and the quartz sand can effectively separate the arc, absorb metal vapor and cool the arc, thereby improving the arc extinguishing effect.

[0071] By comparing Example 1 and Comparative Example 2, it can be seen that the arc extinguishing effect of Example 1 is better than that of Comparative Example 2, which indicates that compared with soft magnetic powder, hard magnetic powder can provide a stronger and more lasting magnetic field, which is not only beneficial to improving the magnetic field arc blowing ability of the magnetic composite material layer, but also beneficial to maintaining the long-term stability of the performance of the magnetic composite material layer.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a fuse with a magnetic arc blowing function, characterized in that: The following steps are involved: (1) providing an alloy melt, wherein the alloy melt has at least two wide sections along its length direction, a narrow section is formed between two adjacent wide sections, and a cross-sectional area of ​​the narrow section is smaller than a cross-sectional area of ​​the wide section; (2) directly printing a magnetic composite slurry on the surface of the wide section, and then curing it to form at least two magnetic composite material layers, wherein the magnetic composite slurry includes hard magnetic powder; (3) performing magnetization treatment on the magnetic composite material layers so that the two adjacent magnetic composite material layers generate magnetic fields in the same direction in the narrow section, and the angle between the direction of the magnetic field and the length direction of the alloy melt is an acute angle or a right angle; (4) placing the alloy melt obtained after step (3) inside a shell, and then adding quartz sand into the shell; Calculated by weight, the raw materials for preparing the magnetic composite slurry include 30 to 60 parts of epoxy resin, 5 to 30 parts of epoxy resin curing agent, 10 to 30 parts of SiO2 particles, 5 to 50 parts of hard magnetic powder and 5 to 15 parts of flame retardant.

2. The method for preparing a fuse with a magnetic arc blowing function according to claim 1, characterized in that: The curing includes curing at room temperature for 2 to 48 hours.

3. The method for preparing a fuse with a magnetic arc blowing function according to claim 1, characterized in that: The magnetic composite material layer is in a rectangular parallelepiped or cylindrical shape.

4. The method for preparing a fuse with a magnetic arc blowing function according to claim 1, characterized in that: The magnetization treatment includes magnetization at a magnetic field strength of 0.5 to 5 T for 0.5 to 5 hours.

5. The method for preparing a fuse with a magnetic arc blowing function according to claim 1, characterized in that: After the magnetic composite material layer is magnetized, the magnetic composite material layer has an N pole and an S pole along the width or height direction of the alloy melt, and the direction of the magnetic field is from the N pole to the S pole.

6. The method for preparing a fuse with a magnetic arc blowing function according to claim 1, characterized in that: The hard magnetic powder includes at least one of neodymium iron boron powder, neodymium iron nitrogen powder, aluminum nickel cobalt powder, ferrite powder, chromium oxide powder and samarium cobalt powder.

7. The method for preparing a fuse with a magnetic arc blowing function according to claim 1, characterized in that: The particle size of the SiO2 particles is 40 to 250 μm, the particle size of the quartz sand is 0.5 to 4 mm, and the particle size of the hard magnetic powder is 5 to 150 μm.

8. The method for preparing a fuse with a magnetic arc blowing function according to claim 1, characterized in that: The epoxy resin includes at least one of bisphenol A epoxy resin, butanediol diglycidyl ether epoxy resin and epoxidized polybutadiene resin; the epoxy resin curing agent includes at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, metaphenylenediamine, benzyldimethylamine, triethanolamine, 4,4'-diaminodiphenylmethane, benzyldimethylamine, maleic anhydride, pyromellitic anhydride and tung oil modified anhydride.

9. A fuse with magnetic arc blowing function, characterized in that: The invention is prepared by the preparation method of a fuse with magnetic arc blowing function as claimed in any one of claims 1 to 8.

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