Preparation method of ferromagnetic annular rubber magnet

Abstract

The invention discloses a preparation method of a ferromagnetic annular rubber magnet, which comprises the following steps: providing a sheet material of the rubber magnet, and cutting the sheet material into strips to form a plurality of rubber magnetic strips; performing primary cold pressing treatment on the rubber magnetic strip, so that the two ends of the rubber magnetic strip are jointed to form a conical annular magnet; performing secondary cold pressing treatment on the conical annular magnet to form an annular magnet; and carrying out hot-pressing vulcanization, cooling shaping and magnetizing on the annular magnet in a high-intensity magnetic field to realize special magnetic circuit magnetization so as to obtain the ferromagnetic annular rubber magnet. According to the preparation method, the annular rubber magnet which is high in raw material utilization rate and has strong magnetism can be prepared.

Description

Technical Field

[0001] This application belongs to the field of magnet processing technology, specifically relating to a method for preparing a strong magnetic ring-shaped rubber magnet. Background Technology

[0002] Magnetic materials, as one of the key basic materials of modern industry, have been widely used in motors, sensors, smart devices and other fields. Rubber magnets are flexible permanent magnet materials composed of magnetic powder and rubber. In some special equipment, magnets need to be made into continuous rings to fit irregular curved surfaces. This is usually achieved by stamping or injection molding, but these processing technologies generally suffer from low raw material utilization.

[0003] Furthermore, rubber magnets typically do not require orientation processes and are mostly made of ferrite or isotropic magnetic powder, resulting in relatively weak magnetic properties and magnetic field strength. This limitation restricts the application range of toroidal rubber magnets, especially in environments requiring strong attraction or large gaps. Summary of the Invention

[0004] In view of this, the primary objective of this application is to provide a method for preparing a strongly magnetic toroidal rubber magnet, thereby endowing the toroidal rubber magnet with strong magnetic properties and expanding the application range of the toroidal rubber magnet.

[0005] To achieve the above objectives, this application adopts the following technical solution: One aspect of this application discloses a method for preparing a strongly magnetic toroidal rubber magnet, comprising the following steps: A sheet of rubber magnet is provided, and the sheet is cut into strips to form a plurality of rubber magnet strips; The rubber magnetic strip is subjected to a first cold pressing treatment, so that the two ends of the rubber magnetic strip are joined together to form a conical ring magnet; The conical annular magnet is subjected to a second cold pressing process to form an annular magnet. The ring-shaped magnet is hot-pressed and vulcanized under a strong magnetic field, cooled and shaped, and then magnetized to achieve a special magnetic circuit, thereby obtaining a strongly magnetic ring-shaped rubber magnet.

[0006] Another aspect of this application discloses a strongly magnetic ring-shaped rubber magnet, which is prepared using the preparation method described in the first aspect of this application.

[0007] Another aspect of this application discloses the application of the strong magnetic ring-shaped rubber magnet described herein in motors, drivers, or super-strong magnetic attraction.

[0008] The beneficial effects of this application are: This application employs anisotropic magnetic powder for processing toroidal rubber magnets. Through a progressive cold-pressing process combined with strong magnetic field hot-pressing vulcanization, it not only significantly improves the utilization rate of raw materials (sheet utilization rate approaches 100%), endowing the toroidal rubber magnets with excellent elasticity and toughness, but more importantly, the strong magnetic field orients the anisotropic magnetic powder in the toroidal rubber magnet, enhancing the magnetization effect of the material's magnetic powder and achieving a higher degree of uniformity in orientation. This ensures that the toroidal magnet possesses strong magnetism after orientation and magnetization, increasing the magnetic energy product and magnetic field strength of the toroidal rubber magnet. This allows it to be used in applications requiring high magnetic strength, broadening the application range of toroidal rubber magnets. Attached Figure Description

[0009] Figure 1 This is a flowchart illustrating the manufacturing process of a strongly magnetic ring-shaped rubber magnet in a preferred embodiment of this application.

[0010] Figure 2 This is a schematic diagram of the structure of each stage in the preparation process of the strong magnetic ring rubber magnet in this application.

[0011] Figure 3 This is a schematic diagram of different products obtained after orienting and magnetizing a strongly magnetic ring-shaped rubber magnet in a preferred embodiment of this application. Detailed Implementation

[0012] The embodiments of this application will be clearly and completely described below. The technical solutions in the embodiments described below are exemplary and only possible technical implementations of this application, not all possible implementations. Those skilled in the art can combine the embodiments of this application to obtain other embodiments without creative effort, and these embodiments are also within the protection scope of this application.

[0013] The first aspect of this application discloses a method for preparing a strongly magnetic ring-shaped rubber magnet, comprising the following steps: A sheet of rubber magnet is provided, and the sheet is cut into strips to form a plurality of rubber magnet strips; The rubber magnetic strip is subjected to a first cold pressing treatment, so that the two ends of the rubber magnetic strip are joined to form a conical ring magnet; The conical annular magnet is subjected to a second cold pressing process to form an annular magnet. The ring-shaped magnet is hot-pressed and vulcanized under a strong magnetic field, cooled and shaped, and then magnetized to achieve a special magnetic circuit, thereby obtaining a strongly magnetic ring-shaped rubber magnet.

[0014] In the process of preparing toroidal rubber magnets, this application involves hot-pressing vulcanization and shaping under a strong magnetic field. The strong magnetic field is used to orient the magnetic powder in the toroidal rubber magnet, thereby improving the magnetization effect of the magnetic powder and achieving a higher degree of uniformity in orientation. This increases the magnetic energy product and magnetic field strength of the toroidal rubber magnet, providing a specific solution for its application in a particular field.

[0015] Meanwhile, this application processes several (three or more) rubber magnetic strips into a ring-shaped rubber magnet through a first cold pressing process and a second cold pressing process, thereby achieving a near 100% utilization rate of the sheet material, significantly improving the utilization rate of raw materials and reducing production costs. Furthermore, this application first forms the planar ring shape of the ring-shaped rubber magnet through a cold pressing process, and then performs vulcanization and shaping through a hot pressing process, ensuring the elasticity, toughness, and mechanical strength of the ring-shaped rubber magnet.

[0016] In this application, the preparation of the rubber magnet sheet is not particularly limited, and the sheet can be prepared using techniques known in the art or independently developed. In some specific examples, the preparation of the sheet includes the following steps: Anisotropic magnetic powder, rubber, and rubber additives are mixed to form a composite rubber compound; The composite adhesive is processed into sheet blanks and cooled and shaped to obtain the sheet material.

[0017] Specifically, the anisotropic magnetic powder can be neodymium iron boron magnetic powder or samarium cobalt magnetic powder. Using anisotropic magnetic powder enables highly consistent orientation, thus ensuring that the toroidal rubber magnet possesses strong magnetism after orientation and magnetization.

[0018] In some specific examples, the anisotropic magnetic powder is neodymium iron boron (NdFeB) magnetic powder. As a specific example, the composition of the NdFeB magnetic powder can be RE... x (Fe 1-a M a ) 100-x-y B y In this formula, RE represents rare earth elements, B represents boron, and M represents at least one of Ga, Ti, Cu, Al, and Co. x, y, and a represent the mass content, where x is 28.5 wt.% to 31.0 wt.%, y is 0.90 wt.% to 1.00 wt.%, a does not exceed 2 wt%, and the balance is iron (Fe) and unavoidable impurities.

[0019] The shape of the magnetic powder is generally not limited. The method in this application forces the easy magnetization axis of anisotropic magnetic powder particles to rotate efficiently and accurately along the magnetic field direction, thus eliminating the dependence on particle geometry and achieving a higher degree of uniform orientation. Therefore, magnetic powder of any shape is applicable to this application. Before use, the magnetic powder undergoes drying and sieving. Drying removes moisture from the raw material, reducing its moisture content. Sieving separates the raw material according to particle size, ensuring its dispersibility. There are no particular limitations on the drying and sieving methods; methods well-known in the art, such as hot air drying ovens for hot air circulation drying and vibrating screens for sieving, are used, but the method is not limited to these.

[0020] In this application, the rubber raw material is of a type well known in this application, and specific examples include, but are not limited to, at least one of natural rubber, nitrile rubber, and chloroprene rubber. The rubber undergoes a plasticizing treatment before use to reduce the Mooney viscosity of the rubber raw material and improve the uniformity of subsequent mixing. There is no particular limitation on the plasticizing method; methods well known in the art can be used. As a specific example, the plasticizing treatment is carried out using a two-roll mill, which has two relatively rotating rollers. During plasticizing, the rubber raw material is subjected to compression and shearing action between the two rollers.

[0021] In this application, the rubber additives include vulcanizing agents, accelerators, and coupling agents. The vulcanizing agents and accelerators ensure that the magnetic powder-rubber composite compound can form a stable three-dimensional network structure during subsequent hot pressing, thereby achieving good elasticity and mechanical strength. The coupling agent greatly enhances the interfacial bonding force between the magnetic powder and the rubber matrix, significantly improving not only the strength and toughness of the magnetic powder-rubber composite compound but also the dispersibility of the magnetic powder, further enhancing its magnetic properties. There are no particular limitations on the specific types of vulcanizing agents, accelerators, and coupling agents; types well-known in the art can be used. For example, the vulcanizing agent can be sulfur, the accelerator can be dibenzothiazole disulfide, and the coupling agent can be a silane coupling agent, but it is not limited to the above examples.

[0022] In composite rubber compounds, the proportions of each component can be adjusted based on the actual product requirements without particular limitations. In some specific examples, the mass ratio of the anisotropic magnetic powder, rubber, and rubber additives is (4-10):1:(0.1-0.4); and in the rubber additives, the mass ratio of the vulcanizing agent, coupling agent, and accelerator is (2-4):(2-4):(1-3).

[0023] In the preparation of the composite rubber compound, the magnetic powder, rubber raw materials, and rubber additives can generally be mixed using a Banbury mixer. Furthermore, there are no particular limitations on the method of processing the composite rubber compound into sheet blanks. As a preferred example, the composite rubber compound can be extruded or calendered, followed by shaping and cooling to obtain sheets. Specific process parameters are not particularly required or limited, and can be determined experimentally by those skilled in the art. Subsequent processing and corrections can be avoided and subsequent steps saved by controlling the size of the sheet blank and the circumference of the target annular rubber magnet. As a preferred example, the thickness of the formed sheet blank is 2-10 mm. In some specific examples, shaping and cooling can be performed by conveying the extruded sheet blank to a cooling area (ambient temperature 25℃-30℃) via a conveyor belt, where it is cooled to room temperature by air cooling or natural cooling to complete the shaping of the sheet blank.

[0024] Furthermore, the rubber magnetic strips can typically be cut from sheet material using a CNC cutting machine. The width and length of the rubber magnetic strips should be uniform. As a preferred example, the width of the rubber magnetic strips should be appropriately controlled to ensure that a ring-shaped rubber magnet of the target width is obtained. By determining the width of the rubber magnetic strip during the cutting stage, subsequent processes do not require further correction or cutting of the width of the ring-shaped rubber magnet, reducing post-processing steps, simplifying the process flow, thereby improving production efficiency and avoiding material waste during subsequent trimming of the ring-shaped rubber magnets.

[0025] In this application, the temperatures for the first and second cold pressing processes are independently 45℃-55℃, and the pressures are independently 10-20MPa. At these processing temperatures, the viscosity and plasticity of the magnetic powder-rubber composite material can reach a rational state, making it not only sufficiently soft but also able to flow fully under pressure, fill the mold, and perfectly fuse the overlapping surfaces. At the same time, it will not cause pre-vulcanization due to excessively high temperatures, which would lead to the material hardening and losing its plasticity, thus affecting the final shaping.

[0026] For the first cold pressing process, the two ends of the rubber magnetic strip are joined together and then placed in a cold pressing mold. Cold pressing is performed at 45-55°C to join the two ends of the rubber magnetic strip and form a conical ring magnet (see [reference]). Figure 2 The conical annular magnet has a large ring and a small ring distributed at both ends, and an annular inclined surface extending from the small ring to the large ring. Preferably, the large ring and the small ring are parallel to each other and their centers are located on the same axis. Such a conical annular magnet is a transitional state of annular magnets, which can guide the material to flow smoothly and uniformly radially during subsequent pressing. As a preferred example, the inclination angle of the annular inclined surface is 30°-45°.

[0027] For the second cold pressing process, the conical ring magnet is placed in a cold pressing mold and subjected to a second cold pressing at 45-55℃. Specifically, a vacuum chuck can be used to transfer the conical ring magnet from the mold used in the first cold pressing process to the mold used in the second, where a stamping machine is used to perform the second cold pressing. Because the conical ring has been pre-formed after the first cold pressing, only small radial and axial displacements are needed to evenly fill the mold cavity and form the ring magnet, avoiding severe material deformation. Furthermore, the two cold pressing processes ensure a high utilization rate of the sheet material (close to 100%), significantly reducing production costs.

[0028] In this application, a ring-shaped magnet is hot-pressed and vulcanized under a strong magnetic field to give the ring-shaped rubber magnet a high degree of orientation. As described in this application, the magnetic field strength is not less than 2T, and the direction of the magnetic field can be arbitrary without particular limitation. The distribution pattern of the magnetic field can be single-sided monopole or single-sided multipole, which can be selected according to the performance requirements of the final product.

[0029] In this application, the hot-pressing temperature is 120℃-170℃, and the pressure is 6-15MPa. At this temperature, the rubber molecular chains at the overlapping surfaces of the annular rubber magnets are in a highly active state, thereby macroscopically eliminating the bonding lines between the annular rubber magnets and microscopically forming chemical bonds that are no different from the material's bulk. In practice, a hot press is generally used. The hot press contains heating and pressure devices, enabling precise control of the hot-pressing temperature and pressure. After hot-pressing vulcanization, natural cooling or air cooling is used to cool and solidify the annular rubber magnets, thereby preventing deformation and stabilizing their dimensions.

[0030] This application also includes a step of magnetizing the cooled and shaped annular rubber magnet. Magnetization yields a magnet with a strong magnetic field and a special magnetic circuit, thereby expanding the product's application range. The specific magnetization method can be single-sided unipolar magnetization or single-sided multipolar magnetization. For example... Figure 3 As shown, products magnetized by using different magnetization methods form special magnetic circuits, which can be applied to different fields, expanding the application range of toroidal rubber magnets, such as applications in motors, drivers, or super magnetic attraction.

[0031] In some specific examples, a surface treatment step to form an anti-corrosion layer is included before the final product is formed. By spraying an anti-corrosion layer onto the surface of the annular rubber magnet, the environmental resistance and service life of the annular rubber magnet can be significantly improved. As a specific example, epoxy resin solutions commonly used in the art can generally be used to spray the surface of the annular rubber magnet to form an epoxy resin coating, thereby improving the corrosion resistance of the annular rubber magnet. It is understood that the anti-corrosion layer is not limited to the epoxy resin coating in this application, and those skilled in the art can select appropriate coatings as needed.

[0032] The toroidal rubber magnet obtained in this application not only possesses excellent elasticity, toughness, and mechanical strength, but also retains the inherent softness of rubber, allowing for easy bending and conforming to curved surfaces. The progressive molding method, employing two cold-pressing processes, effectively avoids excessive stretching and stress concentration in the rubber magnetic material, ensuring uniform internal density, precise dimensions, and the absence of cracking defects. More importantly, it overcomes the shortcomings of traditional rubber magnets, such as low magnetic energy product and low magnetic field strength, thereby broadening the application range of toroidal rubber magnets.

[0033] The present application will be further illustrated below with reference to specific embodiments. It should be noted that the specific embodiments below are for illustrative purposes only and do not limit the scope of the present application in any way.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0035] In addition, unless otherwise specified, methods without detailed conditions or steps are conventional methods, and the reagents and materials used are commercially available.

[0036] Example 1 This embodiment discloses a method for preparing a strongly magnetic ring-shaped rubber magnet, the specific steps of which are as follows: (1) Preparation of sheet material: Take 800g of anisotropic NdFeB magnetic powder 30.5 M 0.2 B 0.95 Fe bal The mixture was blended with 80g of natural rubber on a two-roll mill. Then, 6g of sulfur vulcanizing agent, 6g of silane coupling agent, and 4g of dibenzothiazole disulfide accelerator were added sequentially and mixed evenly. The mixture was then sheeted to obtain a compound. The compound was then calendered at a pressure of 10MPa and a temperature of 160℃. After cooling and curing, an anisotropic magnet sheet with a thickness of 3mm was obtained.

[0037] (2) Cut the sheet material into strips to form rubber magnetic strips with a thickness of 3 mm and a width of 20 mm.

[0038] (3) Connect the two ends of each rubber magnetic strip and perform the first cold pressing treatment at a temperature of 50℃ and a pressure of 10MPa to form a conical ring magnet. The inclination angle of the conical ring magnet's ring inclined surface is 30°.

[0039] (4) The conical annular magnet is subjected to a second cold pressing treatment at a temperature of 50°C and a pressure of 10MPa to form an annular magnet with a thickness of 3mm.

[0040] (5) The ring magnet is hot-pressed and vulcanized under a strong magnetic field of 2T at a temperature of 170℃ and a pressure of 15MPa. After cooling and shaping, it is magnetized on one side and one pole to obtain a ring rubber magnet with a thickness of 3mm.

[0041] Example 2 This embodiment discloses a method for preparing a strongly magnetic ring-shaped rubber magnet, the specific steps of which are as follows: (1) Preparation of sheet material: Take 800g of anisotropic NdFeB magnetic powder 30.5 M 0.2 B 0.95 Fe bal The mixture was blended with 80g of natural rubber on a two-roll mill. Then, 6g of sulfur vulcanizing agent, 6g of silane coupling agent, and 4g of dibenzothiazole disulfide accelerator were added sequentially and mixed evenly. The mixture was then sheeted to obtain a compound. The compound was then calendered at a pressure of 10MPa and a temperature of 160℃. After cooling and curing, an anisotropic magnet sheet with a thickness of 5mm was obtained.

[0042] (2) Cut the sheet into strips to form a rubber magnetic strip with a thickness of 5 mm and a width of 20 mm.

[0043] (3) Connect the two ends of each rubber magnetic strip and perform the first cold pressing treatment at a temperature of 50℃ and a pressure of 10MPa to form a conical ring magnet. The inclination angle of the conical ring magnet's ring inclined surface is 40°.

[0044] (4) The conical annular magnet is subjected to a second cold pressing treatment at a temperature of 50°C and a pressure of 10MPa to form an annular magnet with a thickness of 5mm.

[0045] (5) The ring magnet is hot-pressed and vulcanized under a strong magnetic field of 2T at a temperature of 170℃ and a pressure of 15MPa. After cooling and shaping, it is magnetized on one side and one pole to obtain a ring rubber magnet with a thickness of 5mm.

[0046] Example 3 This embodiment discloses a method for preparing a strongly magnetic ring-shaped rubber magnet, the specific steps of which are as follows: (1) Preparation of sheet material: Take 800g of anisotropic NdFeB magnetic powder RE 30.5 M 0.2 B 0.95 Fe bal The mixture was blended with 80g of natural rubber on a two-roll mill. Then, 6g of sulfur vulcanizing agent, 6g of silane coupling agent, and 4g of dibenzothiazole disulfide accelerator were added sequentially. The mixture was mixed evenly and sheeted to obtain a compound. The compound was then calendered at a pressure of 10MPa and a temperature of 160℃. After cooling and curing, an anisotropic magnet sheet with a thickness of 5mm was obtained.

[0047] (2) Cut the sheet into strips to form a rubber magnetic strip with a thickness of 5 mm and a width of 20 mm.

[0048] (3) Connect the two ends of each rubber magnetic strip and perform the first cold pressing treatment at a temperature of 50℃ and a pressure of 10MPa to form a conical ring magnet. The inclination angle of the conical ring magnet's ring inclined surface is 40°.

[0049] (4) The conical annular magnet is subjected to a second cold pressing treatment at a temperature of 50°C and a pressure of 10MPa to form an annular magnet with a thickness of 5mm.

[0050] (5) The ring magnet is hot-pressed and vulcanized under a strong magnetic field of 2.5T at a temperature of 170℃ and a pressure of 15MPa. After cooling and shaping, it is magnetized on one side and one pole to obtain a ring rubber magnet with a thickness of 5mm.

[0051] Comparative Example 1 This comparative example discloses a method for preparing a ring-shaped rubber magnet, which adopts the same implementation method as in Example 1, except that hot-pressing vulcanization and shaping are not performed under a strong magnetic field. The specific steps are as follows: Steps (1)-(4) are the same as in Example 1.

[0052] (5) The ring magnet is hot-pressed and vulcanized at a temperature of 170°C and a pressure of 15MPa. After cooling and shaping, it is magnetized on one side and one pole to obtain a ring rubber magnet with a thickness of 3mm.

[0053] Comparative Example 2 This comparative example discloses a method for preparing a toroidal rubber magnet, which adopts the same implementation method as in Example 1, except that the magnetic powder used in this comparative example is isotropic magnetic powder. The specific steps are as follows: (1) Preparation of sheet material: Take 800g of isotropic neodymium iron boron magnetic powder (NdFeB). 30.5 M 0.2 B 0.95 Fe bal80g of natural rubber was mixed with 80g of natural rubber on a two-roll mill. Then, 6g of sulfur vulcanizing agent, 6g of silane coupling agent, and 4g of dibenzothiazole disulfide accelerator were added in sequence. The mixture was mixed evenly and sheeted to obtain a compound. The compound was then calendered at a pressure of 10MPa and a temperature of 160℃. After cooling and curing, an isotropic magnet sheet with a thickness of 3mm was obtained.

[0054] Steps (2)-(4) are the same as in Example 1.

[0055] (5) The ring magnet is hot-pressed and vulcanized at a temperature of 170°C and a pressure of 15MPa. After cooling and shaping, it is magnetized on one side and one pole to obtain a ring rubber magnet with a thickness of 3mm.

[0056] Comparative Example 3 This comparative example discloses a method for preparing a ring-shaped rubber magnet using injection molding. The specific steps are as follows: Take 800g of anisotropic neodymium iron boron magnetic powder (NdFeB). 30.5 M 0.2 B 0.95 Fe bal 80g of PPS was blended with PPS on a two-roll mill, and then 6g of silane coupling agent and 4g of dibenzothiazole disulfide accelerator were added sequentially. The mixture was mixed evenly, sheeted out, and the compound was obtained. The compound was injection molded and then hot-pressed under a 2T strong magnetic field at a temperature of 170℃ and a pressure of 15MPa. After cooling and setting, it was magnetized on one side and unipolar to obtain a ring magnet with a thickness of 3mm.

[0057] Performance testing The attractive force, surface magnetism, Shore hardness, and elongation at break of the magnets on both sides A and B of Examples 1-3 and Comparative Examples 1-3 were tested using the following methods: Attraction test: Take rubber magnets of the same size, record the attraction force (F) using a tension gauge with an accuracy of ±1%, and measure the sliding force parallel to the adsorption surface by pulling the magnet horizontally. The constant loading speed is 5mm / min. Repeat the test 3 times for each type of magnet and take the average value.

[0058] According to GB / T 43264 Test method for magnetic field distribution on the surface of permanent magnets, GB / T 531.1-2008 Test method for indentation hardness of vulcanized rubber or thermoplastic rubber - Part 1: Shore hardness test (Shore hardness) and GB / T 528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber, the magnetic field strength, Shore hardness and elongation at break are tested.

[0059] The test results are shown in Table 1.

[0060] Table 1. Magnet performance test results

[0061] The test results in Table 1 show that the preparation method of this application can significantly change the magnetic field strength of the rubber magnet and improve its flexibility: the annular rubber magnets obtained in Examples 1-3 have greater surface attraction and surface magnetic field strength, and better flexibility. While the annular rubber magnets obtained in Comparative Examples 1 and 2 have better flexibility, their surface attraction and surface magnetic field strength are relatively low; and while the injection-molded annular magnet obtained in Comparative Example 3 has greater surface attraction and surface magnetic field strength, its Shore hardness is high and its fracture toughness is low. In summary, the annular rubber magnets obtained using the preparation method of this application possess both strong magnetism and flexibility, exhibiting excellent overall performance and broadening the application range of rubber magnets.

[0062] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing a strongly magnetic ring-shaped rubber magnet, characterized in that, Includes the following steps: A sheet of rubber magnet is provided, and the sheet is cut into strips to form a plurality of rubber magnet strips; The rubber magnetic strip is subjected to a first cold pressing treatment, so that the two ends of the rubber magnetic strip are joined to form a conical ring magnet; The conical annular magnet is subjected to a second cold pressing process to form an annular magnet. The ring-shaped magnet is hot-pressed and vulcanized under a strong magnetic field, cooled and shaped, and then magnetized to achieve a special magnetic circuit, thereby obtaining a strongly magnetic ring-shaped rubber magnet.

2. The preparation method according to claim 1, characterized in that, The preparation of the sheet material includes the following steps: Anisotropic magnetic powder, rubber, and rubber additives are mixed to form a composite rubber compound; The composite adhesive is processed into sheet blanks and cooled and shaped to obtain the sheet material; Preferably, the anisotropic magnetic powder is neodymium iron boron or samarium cobalt magnetic powder; Preferably, the anisotropic magnetic powder is dried and sieved; the rubber is plasticized. Preferably, the mass ratio of the anisotropic magnetic powder, rubber, and rubber additives is (4-10):1:(0.1-0.4). Preferably, the rubber additives include vulcanizing agents, accelerators, and coupling agents; Preferably, the mass ratio of the vulcanizing agent, coupling agent and accelerator is (2-4):(2-4):(1-3).

3. The preparation method according to claim 1, characterized in that, The temperatures for the first and second cold pressing treatments are independently 45-55℃, and the pressures are independently 10-20MPa.

4. The preparation method according to claim 1, characterized in that, The conical annular magnet has a large ring and a small ring distributed at both ends, and an annular inclined surface extending from the small ring to the large ring; Preferably, the inclination angle of the annular inclined plane is 30°-45°.

5. The preparation method according to claim 1, characterized in that, The magnetic field strength is not less than 2T, the direction of the magnetic field is arbitrary, and the distribution pattern of the magnetic field is either single-sided monopole or single-sided multipole.

6. The preparation method according to claim 1, characterized in that, The hot pressing temperature is 120℃-170℃, and the pressure is 6-15MPa.

7. The preparation method according to claim 1, characterized in that, After cooling, a surface treatment step is also included to form an anti-corrosion layer.

8. The preparation method according to claim 1, characterized in that, The magnetization method is either single-sided unipolar magnetization or single-sided multipolar magnetization.

9. A strongly magnetic ring-shaped rubber magnet, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. The application of the strong magnetic ring-shaped rubber magnet of claim 9 in motors, drivers, or super magnetic attraction.

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