Halbach array magnet magnetizing device and magnetizing method

Abstract

The application relates to a Halbach array magnet magnetizing device and a magnetizing method, wherein a lower magnetizing head and an upper magnetizing head are installed on a bottom plate, the upper side of the lower magnetizing head is provided with a containing groove for placing a glass fiber plate, and a plurality of Halbach array magnets are embedded in the glass fiber plate; in the application, the first magnet of the Halbach array magnet is first saturatedly magnetized before being assembled, the first magnet and the second magnet are fixed by being adhered according to the Halbach array, and then the second magnet on the glass fiber plate is magnetized by the Halbach array magnet magnetizing device, the fixing and adhering process of the Halbach array magnet does not need to overcome the force in the vertical direction, the assembly thickness can be greatly reduced, the yield is high, and the flatness is good; the post-magnetizing scheme can magnetize the second magnet after the assembly process at a high temperature, and the magnetic decay is far less than that of the pre-magnetizing high-temperature assembly, so that the benefits of the Halbach array can be maximized.

Description

Technical Field

[0001] This invention relates to magnet manufacturing technology, and in particular to a magnetizing device and method for a Heilbeck array magnet. Background Technology

[0002] The Halbach array is a magnetic structure that is an almost ideal structure in engineering. Permanent magnets with different magnetization directions are arranged in a certain order, so that the magnetic field on one side is significantly enhanced while the magnetic field on the other side is significantly weakened. The goal is to generate the strongest magnetic field in the working area with the minimum number of magnets.

[0003] Existing Hellbeck array magnet assemblies are manufactured by first processing magnets into specific sizes and magnetization directions, then magnetizing them according to the specified magnetization direction, and finally assembling them into a Hellbeck array. During assembly, the magnetized magnets are glued together to form a magnetic assembly with a specific magnetic field distribution. Because each magnetized magnet has a specific magnetization direction, when the magnets are arranged in different directions, there will be large repulsive forces and rotational torques between them, which brings great difficulties to the assembly. For example, the "Integrated Magnetization Method of a Hellbeck Array Magnet Assembly" disclosed in CN111009407A includes the following steps: 1) Selecting a suitable blank; 2) First, machining the dimensions of the blank in the assembly direction to the specified dimensions; 3) Assembling the blank in a Hellbeck array according to different magnetization directions to form a Hellbeck array assembly; 4) Then machining the assembled Hellbeck array assembly to the required dimensions to form a Hellbeck array semi-finished product; 5) Performing surface treatment on the Hellbeck array semi-finished product; 6) Integratically magnetizing the surface-treated Hellbeck array semi-finished product to form a Hellbeck array magnet. By assembling without magnetization first, the influence of repulsive force is eliminated, the safety factor of employee operation is increased, and the assembly difficulty is greatly reduced. However, since a Hellbeck array magnet usually includes two sets of magnets with mutually perpendicular magnetization directions, it is technically difficult to magnetize the two sets of magnets with mutually perpendicular magnetization directions separately. Summary of the Invention

[0004] The purpose of this invention is to provide a magnetizing device and method for a Hellbeck array magnet, which solves the problem of difficult assembly and manufacturing of existing Hellbeck array magnets.

[0005] To address the aforementioned problems, this invention provides a Hellbeck array magnetization device. A lower magnetization head and an upper magnetization head are mounted on a base plate. The upper magnetization head is correspondingly positioned to the lower magnetization head and can be raised and lowered vertically. The upper side of the lower magnetization head has a receiving groove for placing a fiberglass plate. Multiple Hellbeck array magnets are embedded in the fiberglass plate. Each Hellbeck array magnet includes a first magnet and a second magnet, both rectangular and of equal thickness. The first magnet is already magnetized, and the second magnet is to be magnetized. The first and second magnets are of the same length and are arranged alternately along the width direction. The magnetization direction of the first magnet is horizontal along the width direction, and the magnetization direction of the second magnet is vertical along the thickness direction. The upper and lower magnetization heads each contain a magnetization core corresponding to one of the second magnets. The cross-sectional shape of the magnetization core is the same as that of the second magnet, and a magnetization coil is wound around the magnetization core.

[0006] The Helbeck array magnetization device provided by this invention has the following technical features: Furthermore, two vertical guide rods are installed on the base plate, and a top plate is installed at the top of the two vertical guide rods. A lifting plate that moves up and down along the vertical guide rods is also installed between the base plate and the top plate. The charging magnetic head is installed on the lower side of the lifting plate. A lifting cylinder is installed on the upper side of the top plate. The telescopic rod of the lifting cylinder passes down through the top plate and connects to the upper side of the lifting plate to drive the lifting plate to move up and down. Furthermore, two sets of symmetrically arranged Hellbeck array magnets are embedded in the fiberglass board. Each set of Hellbeck array magnets includes seven Hellbeck array magnets arranged sequentially along the length of the second magnet. The upper and lower charging heads are provided with charging cores corresponding to the second magnets in each Hellbeck array magnet. The upper and lower charging heads are also provided with auxiliary winding iron cores located outside the charging cores of each set of Hellbeck array magnets.

[0007] Furthermore, each group of seven Helbeck array magnets has a gap between them that corresponds to the magnetization coil.

[0008] Furthermore, there are equivalent intervals for winding magnetizing coils between adjacent magnetizing cores, between adjacent magnetizing cores and auxiliary winding cores, and between adjacent auxiliary winding cores. The width of the equivalent interval is equal to the width of the first magnet.

[0009] This invention provides a method for magnetizing a Hellbeck array magnet, characterized by comprising the following steps: S10, process the first magnet and the second magnet, which are rectangular sheets of the same length and thickness, to the specified size; S20, saturate the first magnet with magnetization along the width direction of the first magnet; S30, the first magnet after being magnetized and the second magnet without being magnetized are arranged alternately along the width direction according to the Heilbeck array and then bonded and fixed to form a semi-finished assembly, so that the magnetic field of the first magnet is horizontal and the magnetization direction of the second magnet is vertical. S40, the semi-finished product assemblies are placed sequentially in the groove of the fiberglass board, and then a hot-melt cover plate is placed on the upper side of the fiberglass board; then, the hot-melt cover plate is thermoplastically molded and bonded to the upper side of the fiberglass board by high temperature hot pressing, and each of the semi-finished product assemblies is wrapped and fixed in the groove. S50, the high-temperature hot-pressed fiberglass board is placed into the above-mentioned Heilbeck array magnetization device, and the second magnet in each of the semi-finished product assemblies in the fiberglass board is saturated and magnetized according to the magnetization direction.

[0010] Furthermore, the high-temperature hot pressing temperature for thermoplastic molding in step S40 is 150°C to 170°C.

[0011] Furthermore, the high-temperature hot pressing temperature for thermoplastic molding in step S40 is 160°C.

[0012] Furthermore, in step S10, the width of the second magnet is greater than or equal to 1.5 times the width of the first magnet and less than or equal to 2.5 times the width of the first magnet. Furthermore, in step S10, the width of the first magnet is greater than or equal to twice the thickness of the first magnet, and the width of the first magnet is less than or equal to three times the thickness of the first magnet.

[0013] Furthermore, in step S10, the number of the first magnets is greater than the number of the second magnets.

[0014] Further, in step S10, the number of the first magnet is 2 and the number of the second magnet is 1; or the number of the first magnet is 3 and the number of the second magnet is 2.

[0015] Furthermore, in step S10, the length of the first magnet is greater than or equal to three times the width of the first magnet and less than or equal to six times the width of the first magnet. The Helbeck array magnet magnetization device and method of the present invention saturate magnetize the first magnet (auxiliary magnet) of the Helbeck array magnet before assembly. After the first magnet (auxiliary magnet) and the second magnet (main magnet) are bonded and fixed according to the Helbeck array, the second magnet (main magnet) on the fiberglass board is magnetized by the Helbeck array magnet magnetization device. During the bonding and fixing of the Helbeck array magnet, no vertical force needs to be overcome, and the assembly thickness can be greatly reduced, resulting in a high yield and good flatness. The post-magnetization scheme allows the second magnet (main magnet) to be magnetized after the assembly process at a higher temperature, and its magnetic decay is much less than that of the pre-magnetization high-temperature assembly, which can maximize the benefits of Helbeck. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the Heilbeck array magnetization device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the fiberglass board in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the Hellbeck array magnet in the embodiment of the invention; Figure 4 This is a schematic diagram of the structure of the Hellbeck array magnetization device in an embodiment of the present invention; Figure 5 for Figure 4 Enlarged view of part A in the middle Figure 6 This describes the arrangement of each group of Hellbeck array magnets on the fiberglass board and the arrangement of the charging core on the lower charging head in this embodiment of the invention. Figure 7 This describes the arrangement of the two sets of Hellbeck array magnets on the fiberglass plate and the arrangement of the charging core on the lower charging head in this embodiment of the invention. Figure 8 This is a longitudinal sectional view of the Hellbeck array magnetization device in an embodiment of the present invention; Figure 9 for Figure 8 Enlarged view of the arrangement of the centrally charged magnet cores; Figure 10 This is a cross-sectional view of the Hellbeck array magnetization device in an embodiment of the present invention; Figure 11 for Figure 10 Enlarged view of the arrangement of the centrally charged magnet cores. Detailed Implementation

[0017] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0018] like Figures 1 to 11 In the embodiment of the Hellbeck array magnet magnetization device of the present invention shown, a lower magnetizing head 20 and an upper magnetizing head 30 are mounted on a base plate 10. The upper magnetizing head 30 is correspondingly arranged with the lower magnetizing head 20 and can be raised and lowered in the vertical direction. A receiving groove for placing a fiberglass plate 50 is provided on the upper side of the lower magnetizing head 20. A plurality of Hellbeck array magnets 40 are embedded in the fiberglass plate 50. The Hellbeck array magnet 40 includes a first magnet 41 (auxiliary magnet) and a second magnet 42 (main magnet) that are rectangular sheets of the same thickness. 41 (auxiliary magnet) is magnetized, and the second magnet 42 (main magnet) is to be magnetized; the first magnet 41 and the second magnet 42 have the same length, and the first magnet 41 and the second magnet 42 are arranged alternately along the width direction. The magnetization direction of the first magnet 41 is horizontal along the width direction, and the magnetization direction of the second magnet 42 is vertical along the thickness direction; the upper magnetizing head 30 and the lower magnetizing head 20 are provided with magnetizing cores 401 corresponding to each second magnet 42. The cross-sectional shape of the magnetizing core 401 is the same as that of the second magnet 42, and a magnetizing coil 402 is wound on the magnetizing core 401.

[0019] The Hellbeck array magnet magnetization device and method disclosed in this application involve saturating magnetization of the first magnet (auxiliary magnet) of the Hellbeck array magnet before assembly. The first magnet (auxiliary magnet) and the second magnet (main magnet) are then bonded and fixed according to the Hellbeck array. The magnetization device then magnetizes the second magnet (main magnet) on the fiberglass board. During the bonding and fixing process of the Hellbeck array magnet, no vertical force needs to be overcome, resulting in a significantly reduced assembly thickness, high yield, and good flatness. Furthermore, the post-magnetization scheme allows for magnetization of the second magnet (main magnet) after a high-temperature assembly process, resulting in magnetic decay far less than that caused by the high temperature of the pre-magnetization process. Assembly maximizes the benefits of Hellbeck. This type of Hellbeck array magnet is suitable for both room temperature and high temperature assembly processes. When using the room temperature assembly process, the intrinsic coercivity requirements of the first magnet (auxiliary magnet) and the second magnet (main magnet) are relatively low. When using the high temperature assembly process, the first magnet (auxiliary magnet) needs to use magnets with higher intrinsic coercivity, while the second magnet (main magnet) can use magnets with lower intrinsic coercivity. After high temperature assembly, the second magnet (main magnet) is then magnetized, resulting in lower overall magnet cost and a lower magnetic decay rate in the second magnet (main magnet), thus maximizing overall benefits.

[0020] In one embodiment of this application, preferably, two vertical guide rods 11 are installed on the base plate 10, and a top plate 12 is installed at the top of the two vertical guide rods 11. A lifting plate 13 that moves up and down along the vertical guide rods 11 is also installed between the base plate 10 and the top plate 12. The upper charging magnetic head 30 is installed on the lower side of the lifting plate 13. A lifting cylinder 14 is installed on the upper side of the top plate 12. The telescopic rod of the lifting cylinder 14 passes down through the top plate 12 and connects to the upper side of the lifting plate 13 to drive the lifting plate 13 to move up and down. In one embodiment of this application, preferably, two sets of symmetrically arranged Hellbeck array magnets 40 are embedded in the fiberglass board 50. Each set of Hellbeck array magnets includes seven Hellbeck array magnets 40 arranged sequentially along the length direction of the second magnet 42. The upper filling head 30 and the lower filling head 20 are provided with filling cores 401 corresponding to the second magnets 42 in each Hellbeck array magnet 40. The upper filling head 30 and the lower filling head 20 are provided with auxiliary winding iron cores 403 located outside the filling cores 401 of each set of Hellbeck array magnets 40. This allows for efficient and rapid magnetization of the second magnets (main magnets) in the Hellbeck array magnets on the fiberglass board. The auxiliary winding iron cores 403 facilitate the winding of filling coils 402 according to the magnetization direction of the second magnets in the Hellbeck magnets.

[0021] In one embodiment of this application, preferably, as shown below, Figure 2 , Figure 4 , Figure 6 As shown, there are gaps between the seven Helbeck array magnets 40 in each group of Helbeck array magnets 40, corresponding to the magnetizing coils 402.

[0022] In one embodiment of this application, preferably, there are equivalent intervals for winding magnetizing coils 402 between adjacent magnetizing cores 401, between adjacent magnetizing cores 401 and auxiliary winding iron cores 403, and between adjacent auxiliary winding iron cores 403. The width of the equivalent interval is equal to the width of the first magnet 41, so that the gap between two adjacent second magnets 42 of the magnetizing coil 402 corresponds, thereby reducing the magnetic field attenuation of the already magnetized first magnet 41 while magnetizing the second magnets 42.

[0023] The present invention also provides a method for magnetizing a Hellbeck array magnet, comprising the following steps: S10, the first magnet 41 and the second magnet 42, which are rectangular sheets of the same length and thickness, are processed to the specified size; S20, the first magnet is saturated and magnetized along the width direction of the first magnet 41; S30, the first magnet 41 after being magnetized and the second magnet 42 without being magnetized are arranged alternately along the width direction according to the Heilbeck array and bonded to form a semi-finished assembly, so that the magnetic field of the first magnet 41 is horizontal and the magnetization direction of the second magnet 42 is vertical. S40, the semi-finished product assembly is placed sequentially in the groove of the fiberglass board 50, and then a hot-melt cover plate is covered on the upper side of the fiberglass board 50; then the hot-melt cover plate is thermoplastically molded and bonded to the upper side of the fiberglass board 50 by high temperature hot pressing, and each of the semi-finished product assemblies is wrapped and fixed in the groove. S50, the high-temperature hot-pressed fiberglass board 50 is placed into the above-mentioned Heilbeck array magnetization device, and the second magnet 42 in each of the semi-finished product assemblies in the fiberglass board 50 is saturated magnetized according to the magnetization direction.

[0024] In one embodiment of this application, preferably, the high-temperature hot-pressing temperature of the thermoplastic molding in step S40 is 150°C to 170°C. Preferably, the high-temperature hot-pressing temperature of the thermoplastic molding in step S40 is 160°C. Specifically, the thermoplastic cover plate is usually made of fiberglass, and the hot-pressing temperature required for thermoplastic molding is 150°C to 170°C. Within this temperature range, most magnetic materials exhibit high magnetic decay. To reduce the impact of high temperature on the magnet, it is usually necessary to use magnets with high intrinsic coercivity, which significantly increases the cost of the magnets. This application, by adopting a scheme of thermoplastic molding followed by magnetization of the second magnet, can ensure the magnetic attraction of the first magnet while allowing the use of magnets with lower intrinsic coercivity for the second magnet, thereby reducing production costs. In one embodiment of this application, preferably, in step S10, the width of the second magnet is greater than or equal to 1.5 times the width of the first magnet and less than or equal to 2.5 times the width of the first magnet; the width of the first magnet is greater than or equal to 2 times the thickness of the first magnet and less than or equal to 3 times the thickness of the first magnet; the length of the first magnet is greater than or equal to 3 times the width of the first magnet and less than or equal to 6 times the width of the first magnet. Figure 3As shown, the dimensions of the first magnet 41 (auxiliary magnet) are 7.5*3.4*0.7 (length*width*thickness), and the dimensions of the second magnet 42 (main magnet) are 7.5*1.8*0.7 (length*width*thickness in the magnetization direction). Specifically, the overall dimensions are designed based on the total dimensions of the product. The length, width, and magnetization thickness of both the main and auxiliary magnets depend on the dimensions of the product to be designed. In terms of overall dimension matching, attention should be paid to the thickness of the auxiliary magnet in the magnetization direction. The thickness of the auxiliary magnet in the magnetization direction should not be too long (the longer the auxiliary magnet is, the greater the sacrifice of the adsorption area of ​​the main magnet). However, it is necessary to maintain the Pc value of the auxiliary magnet at 1.2 or even above 1.4. The purpose is to maximize the Pc value of the auxiliary magnet while minimizing the sacrifice of the adsorption area of ​​the main magnet, thereby enhancing the temperature resistance of the auxiliary magnet. The width / length of the main magnet is calculated by subtracting the length of the auxiliary magnet in the magnetization direction from the overall length and then dividing by the number of main magnets.

[0025] In one embodiment of this application, preferably, as shown below, Figure 3 As shown, the number of first magnets 41 in each Hellbeck array magnet 40 is greater than the number of second magnets 42. The number of first magnets 41 is 3 and the number of second magnets 42 is 2, so that the magnetic field of the Hellbeck array magnet 40 is evenly distributed in the attraction difference.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A Helbeck array magnet magnetizing device, comprising a lower magnetizing head and an upper magnetizing head mounted on a base plate, wherein the upper magnetizing head is correspondingly arranged to the lower magnetizing head and is vertically movable; characterized in that, The upper side of the lower charging head is provided with a receiving groove for placing a fiberglass plate. Multiple Hellbeck array magnets are embedded in the fiberglass plate. Each Hellbeck array magnet includes a first magnet and a second magnet, both rectangular and of equal thickness. The first magnet is already magnetized, and the second magnet is to be magnetized. The first and second magnets are of the same length and are arranged alternately along the width direction. The magnetization direction of the first magnet is horizontal along the width direction, and the magnetization direction of the second magnet is vertical along the thickness direction. The upper and lower charging heads are equipped with corresponding grooves for each of the second magnets. The magnet has a corresponding magnetic core with the same cross-sectional shape as the second magnet, and a magnetic coil is wound around the magnetic core. Two sets of symmetrically arranged Hellbeck array magnets are embedded in the fiberglass plate. Each set of Hellbeck array magnets includes seven Hellbeck array magnets arranged sequentially along the length of the second magnet. The upper and lower magnetic heads are provided with magnetic cores corresponding to the second magnets in each set of Hellbeck array magnets. The upper and lower magnetic heads are also provided with auxiliary winding iron cores located outside the magnetic cores of each set of Hellbeck array magnets.

2. The Hellbeck array magnet magnetizing device according to claim 1, characterized in that, Two vertical guide rods are installed on the base plate, and a top plate is installed at the top of the two vertical guide rods. A lifting plate that moves up and down along the vertical guide rods is also installed between the base plate and the top plate. The upper charging magnetic head is installed on the lower side of the lifting plate. A lifting cylinder is installed on the upper side of the top plate. The telescopic rod of the lifting cylinder passes down through the top plate and connects to the upper side of the lifting plate to drive the lifting plate to move up and down.

3. The Hellbeck array magnet magnetizing device according to claim 1, characterized in that: Each group of seven Hellbeck array magnets has a gap between them that corresponds to the magnetization coil.

4. The Hellbeck array magnet magnetizing device according to claim 1, characterized in that: An equivalent interval for winding a magnetizing coil is provided between adjacent magnetizing cores, between adjacent magnetizing cores and auxiliary winding cores, and between adjacent auxiliary winding cores. The width of the equivalent interval is equal to the width of the first magnet.

5. A method for magnetizing a Hellbeck array magnet, characterized in that, Includes the following steps: S10, process the first magnet and the second magnet, which are rectangular sheets of the same length and thickness, to a specified size; S20, saturate magnetize the first magnet along its width; S30, arrange the magnetized first magnet and the unmagnetized second magnet alternately along the width direction in a Hellbeck array and bond them together to form a semi-finished assembly, so that the magnetic field of the first magnet is horizontal and the magnetization direction of the second magnet is vertical; S40, place the semi-finished assembly in the groove of the fiberglass board, and then cover the upper side of the fiberglass board with a thermoplastic cover plate; then, use high temperature hot pressing to thermoplasticize and bond the thermoplastic cover plate to the upper side of the fiberglass board and wrap and fix each semi-finished assembly in the groove; S50, place the high temperature hot-pressed fiberglass board into the Hellbeck array magnetization device according to any one of claims 1 to 4, and saturate magnetize the second magnet in each semi-finished assembly in the fiberglass board according to the magnetization direction.

6. The method for magnetizing a Hellbeck array magnet according to claim 5, characterized in that: The high-temperature hot pressing temperature for thermoplastic molding in step S40 is 150°C to 170°C.

7. The method for magnetizing a Hellbeck array magnet according to claim 6, characterized in that: The high-temperature hot pressing temperature for thermoplastic molding in step S40 is 160℃.

8. The method for magnetizing a Hellbeck array magnet according to claim 5, characterized in that: In step S10, the width of the second magnet is greater than or equal to 1.5 times the width of the first magnet and less than or equal to 2.5 times the width of the first magnet.

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