Method for manufacturing anisotropic magnets, method for manufacturing magnet assemblies, anisotropic magnets, magnet assemblies, and composite magnet assemblies

Abstract

To provide a method for producing a highly anisotropic magnet and a method for producing a magnet assembly that offer higher design flexibility and improved economic efficiency, compared with existing techniques.SOLUTION: The method for producing a highly anisotropic magnet having four surfaces SF1, SF2, SF3, and SF4 includes: a magnetic-field forming step S20 in which a magnetic field in a first direction is applied to one effective surface VSF (SF1) among the four surfaces and magnetic fields in a second direction are respectively applied to the remaining three surfaces SF2, SF3, and SF4 while performing in-field molding; and a four-side magnetizing step S40 in which the magnetic field in the first direction is applied to the effective surface VSF (SF1) and the magnetic fields in the second direction are applied to the remaining three surfaces SF2, SF3, and SF4 to perform magnetization.SELECTED DRAWING: Figure 17

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a polar anisotropic magnet, a method for manufacturing a magnet assembly, a polar anisotropic magnet, a magnet assembly, and a composite magnet assembly. [Background technology]

[0002] It is known that magnet assemblies composed of magnets arranged in a so-called Halbach configuration can produce magnetic flux at high magnetic flux density. However, realizing this Halbach configuration presents many difficulties, as it involves bonding strongly magnetized magnets together under conditions of strong attractive and repulsive forces, and for this reason, mass production is still not in sight.

[0003] As an alternative technology that can obtain a magnetic flux density at the same level as a Halbach array and has the potential for mass production, a magnet assembly with the configuration described in Figure 3 of Patent Document 1 (hereinafter simply referred to as the magnet assembly described in Patent Document 1) is known.

[0004] Figure 30 is a cross-sectional view illustrating the magnet assembly 900 described in Patent Document 1. The arrows drawn inside the magnet assembly 900 indicate the magnetization direction. As shown in Figure 30, the magnet assembly 900 consists of a cylindrical outer magnet assembly 900EX and an inner magnet assembly 900IN. The outer magnet assembly 900EX has a polar anisotropic arrangement in which the magnetization direction is tilted at an angle θHEX with respect to the normal NL of the magnet assembly 900EX. The angle θHEX is greater than 45 degrees and close to 90 degrees, meaning that the magnetization direction has a relatively shallow angle with respect to the tangent to the outer surface (not shown in the figure), making it a magnet assembly with a "horizontal polar anisotropic arrangement". On the other hand, the inner magnet assembly 900IN has a polar anisotropic arrangement in which the magnetization direction is tilted at an angle θHIN with respect to the normal NL. The angle θHIN is greater than or equal to 0 degrees and less than 45 degrees, meaning that the magnetization direction has a relatively deep angle with respect to the tangent to the inner surface (not shown in the figure), making it a magnet assembly with a "vertical polar anisotropic arrangement".

[0005] This magnet assembly 900 was obtained by separately manufacturing the outer magnet assembly 900EX (also called cylindrical body 900EX) and the inner magnet assembly 900IN (also called cylindrical body 900IN), and then fitting these cylindrical bodies together to form a single unit.

[0006] Since the manufacturing methods for the outer-circumferential magnet assembly 900EX and the inner-circumferential magnet assembly 900IN are basically the same, the manufacturing of the outer-circumferential cylindrical body 900EX will be used as a representative example for explanation. Figure 31 is a diagram illustrating the conventional manufacturing method of the magnet assembly 900EX. (1) in Figure 31 shows the mold 810 and magnetic force sources 820S and 820N used in the magnetic field molding process, (2) shows the magnet base material M1, (3) shows the magnetization process, and (4) shows the magnet assembly 900EX removed after the magnetization process is completed.

[0007] Conventional methods for manufacturing magnet assemblies are generally as follows: First, prepare the powder material for the magnets, the mold 810, etc. The mold 810 is formed in a cylindrical shape, with the inside conforming to the shape of the final magnet assembly 900EX. Next, a magnetic field molding process is performed. Powder material is placed inside the mold 810a, and a predetermined magnetic field is applied from the outside of the mold 810 using magnetic sources 820S and 820N to mold the powder material while orienting each molecule along the magnetic field lines (see Figure 31 (1)). This yields the magnet base material M1 (see Figure 31 (2)). After that, necessary intermediate processes (sintering / heat treatment process, surface treatment process, etc.) are carried out, and then a magnetization process is performed by applying a predetermined magnetic field using magnetic sources 830S and 830N (magnetization yoke, etc.) (see Figure 31 (3)). This yields the magnet assembly 900EX (see Figure 31 (4)). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2010-142082 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] However, conventional methods for manufacturing magnet assemblies have several drawbacks, including high costs, low mass production capabilities (e.g., low yield), and numerous design constraints, as described below.

[0010] For example, the mold 810 used in the magnetic field molding process had to be prepared each time the product specifications changed, in a shape that matched the final magnet assembly, which resulted in high mold costs and overall high costs (the mold cost problem).

[0011] Furthermore, when the radial wall thickness of the outer magnet assembly 900EX was designed to be relatively thin with small dimensions, breakage could occur during the sintering and heat treatment process after the magnetic field molding process, resulting in a decrease in yield (the problem of breakage).

[0012] To prevent such damage, the outer magnet assembly 900EX had to be set to a thickness larger than necessary to achieve the intended performance (a design margin had to be added). As a result, the radial thickness of the inner magnet assembly 900IN was reduced, and consequently, the ratio of the thickness of the horizontal polar anisotropic arrangement to the thickness of the vertical radial anisotropic arrangement could not be obtained as intended, and in some cases the desired magnetic force characteristics could not be obtained.

[0013] Furthermore, when attempting to change dimensional specifications such as the radial thickness or outer diameter of the magnet assembly due to model changes or other reasons, problems such as reduced yield or inability to secure the necessary magnetic properties sometimes occurred.

[0014] When a design can ensure sufficient radial thickness of the magnet assembly (refer to thickness T1) as shown in Fig. 32(a), in the vicinity where magnetic field lines are released to the outside, the orientation direction of the powder after the magnetic field forming process can be ensured at a corresponding angle with respect to the outer peripheral surface (it can be an angle relatively close to the normal line NL). Since the orientation direction of the powder becomes the magnetization direction when the magnetization process is performed, ultimately, an axially anisotropic magnet assembly with the desired magnetic properties can be obtained. However, when a design requires reducing the radial thickness as shown in Fig. 32(b) (refer to thickness T2), the orientation direction of the powder can only be ensured at a shallow angle with respect to the outer peripheral surface (it becomes an angle almost 90 degrees with respect to the normal line NL). As a result, it becomes impossible to release magnetic field lines to the outside with the intended intensity, and ultimately, the required magnetic properties as a product may not be ensured. That is, prioritizing reducing the thickness of the magnet assembly would result in sacrificing the design freedom of the orientation direction (magnetization direction), and prioritizing the orientation direction (magnetization direction) would result in sacrificing the design freedom of the thickness of the magnet assembly.

[0015] Furthermore, conventionally, there were also many mass production issues in obtaining axially anisotropic magnets (for example, the axially anisotropic magnets in the portion surrounded by the dashed line C in Fig. 30) that constitute a part of the magnet assembly on the outer peripheral side. If it is assembled in the magnetized state, magnets 905 and 906 magnetized in a substantially horizontal direction would be joined with the same magnetic pole surfaces facing each other. Since it is a joining under a large repulsive force between them, it was difficult to perform mass production (the same applies to the axially anisotropic magnets by magnets 907 and 908 within the dashed line D).

[0016] Incidentally, if it is the base materials before magnetization that become magnets 905 and 906 (temporarily referred to as base materials 905' and 906' (not shown in the figure)), no repulsive force occurs between base material 905' and base material 906', so joining is easy. However, the magnetization method in the subsequent magnetization process has not been established. Ultimately, it was difficult to mass produce the axially anisotropic magnets shown by the dashed lines D and C in Fig. 30.

[0017] Therefore, the present invention has been made in view of the above circumstances, and aims to provide a method for manufacturing polar anisotropic magnets and magnet assemblies that offer greater design flexibility and cost-effectiveness than conventional methods. Furthermore, it aims to provide polar anisotropic magnets, magnet assemblies, and composite magnet assemblies. [Means for solving the problem]

[0018] According to one aspect of the present invention, a method for manufacturing a polar anisotropic magnet having four faces that face four directions when viewed in cross-section is provided. The method for manufacturing a polar anisotropic magnet includes, in this order: a powder material preparation step of preparing a powder material for a magnet; a magnetic field molding step of sequentially introducing the powder material into a mold corresponding to the desired shape of the polar anisotropic magnet, while applying a magnetic field in a first direction to a virtual effective surface and a magnetic field in a second direction to the remaining three surfaces from the outside of the mold, with the surface on which magnetic flux should be concentrated being the effective surface; and a four-way magnetization step of magnetizing the magnet material by surrounding the magnet material obtained from the magnet material and applying a magnetic field in a first direction to the effective surface and a magnetic field in a second direction to the remaining three surfaces.

[0019] Furthermore, the polar anisotropic magnet of the present invention is a polar anisotropic magnet having four faces that face four directions when viewed in cross-section, and when the face on which magnetic flux should be concentrated is designated as the effective face, one magnetic pole is arranged on the effective face, and the other magnetic poles are arranged on each of the remaining three faces other than the effective face, and when viewed in cross-section, it is formed continuously without any adhesive marks inside.

[0020] Furthermore, the magnet assembly of the present invention comprises a plurality of the above-mentioned anisotropic magnets, and the anisotropic magnets are arranged and joined to each other so that one magnetic pole and the other magnetic pole appear alternately.

[0021] Furthermore, according to another aspect of the present invention, a method for manufacturing a cylindrical magnet assembly is provided. A method for manufacturing a magnet assembly comprises a powder material preparation step for preparing powder material for magnets, and a magnetic field molding step for forming a "magnet base material" having a first main surface and a second main surface opposite to the first main surface, wherein the magnetic field molding step involves placing powder material inside a mold corresponding to the shape of the magnet base material, and applying a unidirectional parallel magnetic field from the side corresponding to the first main surface on the outside of the mold to the side corresponding to the second main surface to form the magnet base material, and defining the surface that will become the outer diameter surface of the magnet assembly when assembled as a magnet assembly as the "planned outer diameter surface" and the surface that will become the inner diameter surface as the "planned inner diameter surface", and the cut line of the planned outer diameter surface as the first main surface The process includes, in this order: a cutting step in which the magnet base material is cut along the cut line of the planned outer diameter surface, with the cut line of the planned inner diameter surface set to have an inclination of angle θ1 with respect to the first main surface, and the magnet base material is cut along the cut line of the planned inner diameter surface, with the cut line of the planned inner diameter surface set to have an inclination of angle θ2 with respect to the first main surface, thereby cutting out magnet base material pieces having at least the planned outer diameter surface and the planned inner diameter surface as outer surfaces; an assembly step in which a plurality of magnet base material pieces are combined with each other to assemble a magnet base material assembly; and a magnetization step in which a predetermined magnetic field is applied to the magnet base material assembly from outside the magnet base material assembly at a predetermined position to magnetize the magnet base material assembly.

[0022] Furthermore, the magnet assembly of the present invention has a substantially planar outer diameter surface and an inner diameter surface, and comprises magnet blocks magnetized at a predetermined angle to the outer diameter surface and the inner diameter surface and parallel to a single direction, and a plurality of magnet blocks are joined to each other via surfaces other than the outer diameter surface and the inner diameter surface.

[0023] Furthermore, the composite magnet assembly of the present invention comprises a first embodiment of the magnet assembly in which the angle of the magnetization direction with respect to the outer diameter surface and inner diameter surface of each magnet block is a first angle, and a second embodiment of the magnet assembly in which the angle of the magnetization direction with respect to the outer diameter surface and inner diameter surface of each magnet block is a second angle which is different from the first angle. The composite magnet assembly is joined to each other, with the magnet assembly of the first embodiment positioned on the side that will become the effective H magnetic flux surface of the composite magnet assembly, and the magnet assembly of the second embodiment positioned on the side that will become the effective V magnetic flux surface of the composite magnet assembly.

[0024] According to yet another aspect of the present invention, a method for manufacturing a polarly anisotropic magnet having four faces when viewed in cross-section is provided. A method for manufacturing a polar anisotropic magnet comprises a powder material preparation step for preparing powder material for magnets, and a magnetic field molding step for forming a "magnet base material" having a first main surface and a second main surface opposite to the first main surface, wherein the magnetic field molding step involves placing powder material inside a mold corresponding to the shape of the magnet base material, and applying a unidirectional parallel magnetic field from the side corresponding to the first main surface on the outside of the mold to the side corresponding to the second main surface to form the magnet base material, and when the polar anisotropic magnets are assembled as a magnet assembly, the magnet When the surface that will become the outer diameter surface of the aggregate is defined as the "planned outer diameter surface" and the surface that will become the inner diameter surface is defined as the "planned inner diameter surface", the cut line of the planned outer diameter surface is set to have an inclination of angle θ1 with respect to the first main surface, and the magnet base material is cut along the cut line of the planned outer diameter surface, and the cut line of the planned inner diameter surface is set to have an inclination of angle θ2 with respect to the first main surface, and the magnet base material is cut along the cut line of the planned inner diameter surface, thereby creating a magnet base material piece having at least the planned outer diameter surface and the planned inner diameter surface as its outer surfaces. A subassembly step comprising, in this order, a cutting step to cut out a magnet base material, a subassembly of a magnet base material having four faces by combining at least four magnet base material pieces, wherein, when the face on which magnetic flux should be concentrated is designated as the effective face of the magnet base material subassembly, a horizontal magnet base material piece cut with angles θ1 and θ2 in the cutting step set to be within the range of more than 45 degrees and less than 90 degrees is placed on the side that will be the effective face of the magnet base material subassembly, and a vertical magnet base material piece cut with angles θ1 and θ2 in the cutting step set to be within the range of 0 degrees or more and less than 45 degrees is placed on the side opposite to the effective face to assemble the magnet base material subassembly, and a four-way magnetization step to magnetize the magnet base material subassembly by applying a magnetic field in a first direction to the effective face of the magnet base material subassembly and a magnetic field in a second direction to the remaining three faces, surrounding the magnet base material subassembly.

[0025] The above configuration provides a method for manufacturing polar anisotropic magnets and magnet assemblies that offers greater design flexibility and cost-effectiveness than conventional methods. [Brief explanation of the drawing]

[0026] [Figure 1] This is a cross-sectional view illustrating an example of a magnet assembly 100. [Figure 2] This is a cross-sectional view showing the state of the material 5 before magnetization, before it becomes a polar anisotropic magnet (1N,1S). [Figure 3] This diagram illustrates an example of a polar anisotropic magnet, 1N,1S. [Figure 4] This diagram illustrates another example of a polar anisotropic magnet, 1N,1S. [Figure 5] This flowchart illustrates the manufacturing method for an anisotropic magnet according to Embodiment 1. [Figure 6] This is a schematic cross-sectional view showing the process of performing the magnetic field molding process S20. [Figure 7] This is a schematic diagram of the magnet base material M1 after the magnetic field molding process S20 has been carried out. [Figure 8] This is a schematic diagram of the magnet material M2 after the processing step S32 has been carried out. [Figure 9] This is a schematic diagram of the magnet material M2' removed after the surface treatment process S33. [Figure 10] This is a schematic cross-sectional view showing the process of performing the four-way magnetization process S40. [Figure 11] This is a diagram illustrating the magnet assembly 100 according to Embodiment 1. [Figure 12] This diagram illustrates the motor 510, generator 520, and actuator 530 related to the application example. [Figure 13] This figure illustrates a modified example of the method for performing the four-way magnetization process S40. [Figure 14] This figure illustrates the modified magnet assemblies 110 and 120. [Figure 15] This figure shows a modified example of a double-layered cylindrical magnet unit 400. [Figure 16]This figure shows a modified example of a double-layered, linear magnet unit 420. [Figure 17] This flowchart illustrates the manufacturing method for the magnet assembly according to Embodiment 2. [Figure 18] This is a diagram illustrating the magnetic field molding process SS20. [Figure 19] This diagram illustrates the cutting process SS40. [Figure 20] This diagram illustrates the SS60 assembly process. [Figure 21] This diagram illustrates the magnetization process SS70. [Figure 22] This is a cross-sectional view showing the cutting process SS40 of Embodiment 3. [Figure 23] This is a cross-sectional view illustrating the assembly process SS60 of Embodiment 3. [Figure 24] This is a cross-sectional view of the magnet assembly 100IN after the magnetization process SS70 of Embodiment 3 has been carried out. [Figure 25] This flowchart illustrates the manufacturing method of the magnet assembly and the manufacturing method of the polar anisotropic magnet according to Embodiment 5. [Figure 26] This diagram illustrates the sub-assembly process SS80. [Figure 27] This diagram illustrates the four-way magnetization process SS85. [Figure 28] This is a schematic diagram illustrating a modified linear motor structure 550 of the application example. [Figure 29] This is a diagram illustrating the details of the linear motor structure 550. [Figure 30] This is a cross-sectional view illustrating the magnet assembly 900 described in Patent Document 1. [Figure 31] This diagram illustrates a conventional manufacturing method for the magnet assembly 900EX. [Figure 32] This is a schematic diagram showing the orientation of powder material in a magnetic field molding process using a conventional manufacturing method. [Modes for carrying out the invention]

[0027] The following describes embodiments of the method for manufacturing an anisotropic magnet, the method for manufacturing a magnet assembly, the anisotropic magnet, the magnet assembly, and the composite magnet assembly according to the present invention with reference to the drawings. Each drawing is a schematic diagram showing an example and does not necessarily strictly reflect the actual dimensions, proportions, etc. In Figures 17 to 32, the dashed or solid lines drawn inside the magnet base material 10, magnet base material pieces 20, 30, etc., indicate the orientation direction of the molecules (easy magnetization axis), and the solid lines with arrows drawn inside the magnet assembly or anisotropic magnet indicate the magnetization direction.

[0028] A. Method for manufacturing a polar anisotropic magnet by tetradirectional magnetization First, we disclose a manufacturing method for polar anisotropic magnets, which are elements that constitute a magnet assembly, by tetradirectional magnetization.

[0029] [Embodiment 1] 1. Anisotropic magnets 1N, 1S and magnet assembly 100 Before explaining the manufacturing method of polar anisotropic magnets, we will describe an example of the polar anisotropic magnets 1N and 1S and the magnet assembly 100 (sometimes called a composite magnet assembly) to be manufactured.

[0030] (1) Magnet assembly 100 Figure 1 is a cross-sectional view illustrating an example of a magnet assembly 100. In Figure 1, the arrow B drawn inside the polar anisotropic magnets 1N and 1S indicates the magnetization direction. The magnet assembly 100 shown in Figure 1 can produce magnetic properties almost identical to those of the magnet assembly 900 described in Figure 3 of Patent Document 1. In the method for manufacturing polar anisotropic magnets according to Embodiment 1, the polar anisotropic magnets 1N and 1S are manufactured in units enclosed by the dotted line in Figure 1.

[0031] (2) Pre-magnetization material 5 by linear molecular orientation (easy magnetization axis) Figure 2 is a cross-sectional view of the portion corresponding to the unit enclosed by the dotted line in Figure 1, showing the state of the pre-magnetization material 5 before it is magnetized to become a polar anisotropic magnet 1N,1S. The thick solid line drawn inside the pre-magnetization material 5 indicates the molecular orientation (easy magnetization axis). As shown in Figure 2, when the interior of the pre-magnetization material 5 is divided into four regions, the molecular orientation (easy magnetization axis) within each region is linear and parallel to each other. Here, θout is the angle between the molecular orientation (easy magnetization axis) of the outer diameter region and the tangent TL to the central part of the outer surface of the pre-magnetization material 5, and θin is the angle between the molecular orientation (easy magnetization axis) of the inner diameter region and the normal NL to the central part of the outer surface of the outer surface of the pre-magnetization material 5. As one example, a split ring-shaped soft magnetic material 6 can be placed on the inner diameter side of the pre-magnetized material 5. In this case, by setting θin to a value greater than 0 degrees, the thickness of the soft magnetic material 6 can be reduced. Furthermore, by appropriately changing the value of θout, the magnetic flux density form of the magnetic field lines output from the central part of the outer surface, which is the position indicated by the normal NL, can be changed. By magnetizing the pre-magnetization material 5 corresponding to Figure 2 above using an appropriate method, anisotropic magnets 1N and 1S as shown in Figure 3 can be constructed.

[0032] (3) Polar anisotropy of magnets 1N, 1S due to linear magnetization direction Figure 3 is a diagram illustrating an example of a polar anisotropic magnet 1N, 1S. Figures 3(a) and 3(b) show the polar anisotropic magnets 1N and 1S, respectively. In Figure 3, the arrow B drawn inside the polar anisotropic magnets 1N and 1S indicates the magnetization direction. As shown in Figure 3(a), the polar anisotropic magnet 1N has four faces SF1, SF2, SF3, and SF4 when viewed in cross-section. These four faces SF1, SF2, SF3, and SF4 face four directions (thick arrows). Here, "four faces" refers to roughly four faces. When viewed in cross-section, the contours formed by each face may be straight or curved. Furthermore, multiple straight or curved lines may be partially refracted. For example, straight or curved lines that are refracted at an angle of 90 degrees or less and continue are also treated as roughly one face in this context.

[0033] The shapes shown in Figures 2 and 3 are also the "intended shapes of the polar anisotropic magnets" to be manufactured. Here, the "intended shapes of the polar anisotropic magnets" are what is known as arc shapes, and when viewed in cross-section, examples of segmented ring shapes obtained by dividing a ring into N equal parts are shown (where N is a natural number greater than or equal to 2). If polar anisotropic magnets 1N and 1S are applied, for example, as a cylindrical rotor, the first surface SF1 becomes the outer surface and the second surface SF2 becomes the inner surface.

[0034] Here, we define the surface on which magnetic flux should be concentrated as the "effective surface VSF" among the four surfaces. In the polar anisotropic magnets 1N and 1S according to Embodiment 1, magnetic flux is concentrated outwards from near the center of the effective surface VSF (first surface SF1). When such anisotropic magnet is applied, for example, as a rotor in an electric machine such as a motor, the effective surface VSF is positioned on the side facing the stator. When the effective surface VSF is set on the outer circumferential surface side (first surface SF1), the anisotropic magnet can be suitably used as an inner rotor. When the effective surface VSF is set on the inner circumferential surface side (second surface SF2), the anisotropic magnet can be suitably used as an outer rotor.

[0035] In the polar anisotropic magnet 1N shown in Figure 3(a), the first surface SF1 is the effective surface VSF. The effective surface VSF (first surface SF1) has a north pole (one magnetic pole), while the remaining second surface SF2, third surface SF3, and fourth surface SF4 have south poles (other magnetic poles). On the other hand, the polar anisotropic magnet 1S shown in Figure 3(b) is magnetized in the opposite direction to the polar anisotropic magnet 1N, with a south pole (one magnetic pole) on the effective surface VSF (first surface SF1), and north poles (other magnetic poles) on the remaining second surface SF2, third surface SF3, and fourth surface SF4. Furthermore, the polar anisotropic magnets 1N and 1S shown in Figure 3 are also subject to this embodiment 1.

[0036] (4) Another polar anisotropic magnet 1N, 1S depending on the magnetization direction of the curve Figure 4 is a diagram illustrating another example of a polar anisotropic magnet 1N,1S. Figure 3 shows a polar anisotropic magnet 1N,1S with a linear magnetization direction. Another polar anisotropic magnet 1N,1S, shown in Figure 4, can be considered, which has a similar configuration to the polar anisotropic magnet 1N,1S shown in Figure 3 and can produce almost equivalent magnetic properties, such as one in which the internal magnetization direction traced is a curve. This other polar anisotropic magnet 1N,1S is also subject to this embodiment 1. The explanation of the four faces (SF1, SF2, SF3, SF4), effective surface VSF, etc., related to the other polar anisotropic magnet 1N,1S shown in Figure 4 will be based on the explanation of the polar anisotropic magnet 1N,1S shown in Figure 3. A detailed explanation of the polar anisotropic magnets 1N and 1S, and the magnet assembly 100 will be provided later.

[0037] 2. Method for manufacturing an anisotropic magnet according to Embodiment 1 Figure 5 is a flowchart illustrating the manufacturing method of a polar anisotropic magnet according to Embodiment 1. Figure 6 is a schematic cross-sectional view showing the magnetic field molding process S20. Figure 7 is a schematic diagram of the magnet base material M1 removed after the magnetic field molding process S20. Figure 8 is a schematic diagram of the magnet material M2 removed after the processing process S32. The dashed line in Figure 8 shows the outline of the outer shape of the magnet base material M1. Figure 9 is a schematic diagram of the magnet material M2' removed after the surface treatment process S33. Figure 10 is a schematic cross-sectional view showing the four-way magnetization process S40.

[0038] As shown in Figure 5, the method for manufacturing a polar anisotropic magnet according to Embodiment 1 includes at least a powder material preparation step S10, a magnetic field molding step S20, and a four-way magnetization step S40 in this order. Embodiment 1 further includes an intermediate step S30 (e.g., a sintering and heat treatment step S31) between the magnetic field molding step S20 and the four-way magnetization step S40.

[0039] (1) Powder material preparation process S10 The powder material preparation step S10 is the process of preparing the powder material PD for magnets. Existing general methods can be used to prepare the powder material for magnets. For example, assuming a neodymium magnet, raw materials such as neodymium, iron, and boron can be dissolved and solidified, and the solid material can be coarsely and finely ground using a crusher, mill, etc. to prepare the powder material PD for magnets.

[0040] (2) Magnetic field molding process S20 The magnetic field molding process S20 is a process in which powder material PD is sequentially introduced into the mold 710 from the outside of the mold 710 corresponding to the initial shape of the polar anisotropic magnet, while applying a magnetic field in a first direction to the virtual effective surface VSF' (the term "virtual" is used because the prototype of the polar anisotropic magnet has not yet been formed) and applying magnetic fields in a second direction to the remaining three surfaces (see Figures 5 and 6).

[0041] In terms of specific configuration, as shown in Figure 6, a mold 710 corresponding to the "intended shape of the polar anisotropic magnet" is prepared, and outside the mold 710, the first magnetic force source 721 is placed so that the first magnetic pole faces the virtual effective surface VSF', and the second magnetic force sources 722b, 722a, and 722c are placed so that the second magnetic pole faces each of the remaining three surfaces (bottom, right, and left sides in the figure) other than the virtual effective surface. In Figure 6, an example is shown where the first magnetic pole is the north pole and the second magnetic pole is the south pole.

[0042] With this arrangement in place, a magnetic field in a first direction is applied to the virtual effective surface VSF' by the first magnetic source 721, while magnetic fields in a second direction are applied to the remaining three surfaces by the second magnetic source 722. The powder material PD is then sequentially poured into the mold 710 to form a magnet base material M1 that conforms to the shape of the mold 710. Before pouring the powder material PD into the mold 710, a binder is mixed in. When the powder material PD is poured into the mold 710, which is subjected to a predetermined magnetic field, the powder is layered while the orientation of each molecule of the powder material PD aligns with the direction of the magnetic field. At this time, pressure is applied from the outside of the mold 710.

[0043] By performing the magnetic field molding process S20 in this manner, a magnet base material M1, as shown in Figure 7, can be obtained. The solid lines in the magnet base material M1 shown in Figure 7 schematically represent the molecular arrangement direction (molecular orientation).

[0044] Furthermore, the widths of the first magnetic field source 721 and the second magnetic field source 722, as well as the placement of the first magnetic pole (peak portion) of the first magnetic field source 721 and the second magnetic pole (peak portion) of the second magnetic field source 722 relative to the formwork 710, can be appropriately changed according to the design intent. The output (strength of the applied magnetic field) of the first magnetic field source 721 and the second magnetic field source 722 on each surface can also be set to an appropriate magnitude (magnetic field strength) according to the design intent. In this case, the molecular alignment direction (molecular orientation / easy magnetization axis / magnet arrangement) can be easily changed by adjusting the magnetic field line strengths of the second magnetic field sources 722b, 722a, and 722c. Consequently, the magnetic flux density form of the magnetic field lines output from the effective surface VSF of the polar anisotropic magnets 1N and 1S can also be appropriately modified in the design.

[0045] Here, "first direction" and "second direction" indicate either the direction towards the inside or outside of the formwork 710, and the first and second directions are opposite to each other. In the example in Figure 6, the "first direction" is the direction in which the magnetic field lines point from the first magnetic pole of the first magnetic source 721 towards the inside of the formwork 710, and the "second direction" is the direction in which the magnetic field lines point from the inside of the formwork 710 towards the second magnetic pole of the second magnetic source 722. The "first direction" and "second direction" are defined similarly not only as directions relative to the formwork 710 as described above, but also as directions relative to the magnetic materials M2 and M2'.

[0046] Furthermore, by positioning the inner surface SF2 facing the first magnetic source 721 and the outer surface SF1 facing the second magnetic source 722b, it is possible to create a polar anisotropic magnet with an effective surface VSF on the inner surface SF2. Such deformations are also possible in the four-way magnetization process S40 (Figure 10, etc.), which will be described later.

[0047] (3) Intermediate process S30 Intermediate process S30 is a process in which the magnet base material M1 obtained in the magnetic field molding process S20 is subjected to intermediate processing in order to be fed into the four-way magnetization process S40, which will be described later (see Figure 5).

[0048] In Embodiment 1, a sintering and heat treatment step S31 is performed on the magnet base material M1 (see Figure 7) obtained by the magnetic field molding step S20. When the sintering and heat treatment step S31 is performed, the binder contained in the magnet base material M1 is vaporized and removed by the heat, increasing the purity of the magnetic material. In addition, as a result of molding in a magnetic field, the inside of the magnet base material M1 may be slightly magnetized, but it is possible to demagnetize it by performing the sintering and heat treatment step S31.

[0049] In Embodiment 1, following the sintering and heat treatment process S31, a processing process S32 is performed to process the sintered and heat-treated magnet base material M1 into the "intended shape of a polar anisotropic magnet" to form a magnet material M2 (see Figure 8). Subsequently, a surface treatment process S33 is performed on the magnet material M2 to form a magnet material M2' by applying a surface treatment for rust prevention (e.g., nickel plating, bright chromate treatment, electrodeposition coating, etc.) (see Figure 9; reference numeral 7 indicates the surface treatment layer), and finally, an inspection process S34 is performed to inspect the finished state of the magnet material M2'. Furthermore, if the inner shape of the mold 710 is the "intended shape of the polar anisotropic magnet," the processing step S32 may be omitted. Also, the surface treatment step S33 may be omitted.

[0050] (4) Four-way magnetization process S40 The four-way magnetization process S40 is a process in which a magnetic field in a first direction is applied to the effective surface VSF (SF1) of the magnetic materials M2 and M2' obtained from the magnetic base material, and a magnetic field in a second direction is applied to the remaining three surfaces (SF2, SF3, SF4) to magnetize the magnetic materials M2 and M2' (see Figures 5 and 10).

[0051] In terms of specific configuration, as shown in Figure 10, first, a first magnetization magnetic force source 731 is placed so as to surround the magnet materials M2 and M2' obtained from the magnet base material M1, with the first magnetic pole facing the effective surface VSF (first surface SF1), and second magnetization magnetic force sources 732b, 732a, and 732c are placed so as to face the second magnetic poles on each of the remaining three surfaces (second surface SF2, third surface SF3, and fourth surface SF4). Note that a so-called magnetization yoke may be used as the first magnetization magnetic force source 731 and the second magnetization magnetic force sources 732b, 732a, and 732c.

[0052] Then, the first magnetization magnetic source 731 and the second magnetization magnetic sources 732a, 732b, and 732c are activated to apply a magnetic field in a first direction to the effective surface VSF (first surface SF1), and a magnetic field in a second direction to the remaining three surfaces (second surface SF2, third surface SF3, and fourth surface SF4) to magnetize the magnetic material M2. Regarding the method of applying the electric field, existing methods can be appropriately adopted. Furthermore, the explanation of the first magnetic pole, the second magnetic pole, the first direction, and the second direction will be based on the explanation in the magnetic field molding process S20. By performing the four-way magnetization process S40 in this manner, a polar anisotropic magnet of 1N or 2N can be obtained as shown in Figure 2 or Figure 3.

[0053] Furthermore, the widths of the first magnetizing magnetic source 731 and the second magnetizing magnetic source 732, as well as the placement of the first magnetic pole (peak portion) of the first magnetizing magnetic source 731 and the second magnetic pole (peak portion) of the second magnetizing magnetic source 732, can be appropriately changed according to the design intent. In addition, the output (strength of the applied magnetic field) of the first magnetizing magnetic source 731 and the second magnetizing magnetic source 732 on each surface can also be set to an appropriate size (magnetic field strength) according to the design intent. By making these adjustments as appropriate, the thickness of the horizontally polarly anisotropic arrangement and the thickness of the vertically radially anisotropic arrangement when the 1N,1S polarly anisotropic magnets are completed can be arbitrarily set, and the density of the imaginary lines indicating the magnetization direction can also be changed as appropriate.

[0054] In the above explanation and the corresponding drawings, an example of manufacturing an anisotropic magnet 1N was used for explanation. However, when manufacturing an anisotropic magnet 1S, the same procedure can be followed by reversing the polarity by making the first magnetic pole the south pole and the second magnetic pole the north pole, and then reversing the directions of the first and second directions.

[0055] 3. Polar anisotropic magnets 1N, 1S according to Embodiment 1 Next, returning to Figure 4, we will provide a supplementary explanation of the configuration of the polar anisotropic magnets 1N and 1S obtained by the above-described method for manufacturing polar anisotropic magnets.

[0056] The polar anisotropic magnet 1N,1S is a polar anisotropic magnet that has four faces (first face SF1, second face SF2, third face SF3, fourth face SF4) facing four directions (thick arrows) when viewed in cross-section. Of the four faces SF1, SF2, SF3, and SF4 of the polar anisotropic magnet 1N,1S, the face that should concentrate the magnetic flux is designated as the effective face VSF(SF1). One magnetic pole is located on the effective face VSF(SF1), and the other magnetic poles are located on the remaining three faces (SF2, SF3, SF4) other than the effective face VSF. When one magnetic pole is a north pole, the other magnetic poles become south poles. Conversely, when one magnetic pole is a south pole, the other magnetic poles become north poles.

[0057] In the description of Embodiment 1, the polar anisotropic magnets 1N and 1S have a divided ring shape when viewed in cross-section, with the ring divided into N equal parts (where N is a natural number of 2 or more). In this case, when the polar anisotropic magnets 1N and 1S are applied, for example, as a cylindrical rotor, the first surface SF1 becomes the outer surface and the second surface SF2 becomes the inner surface.

[0058] As shown in Figures 2 and 3, for example, the area from the upper part of the third surface SF3 to the central part of the first surface SF1 has a magnetization direction that is relatively close to horizontal, representing a horizontal polar anisotropy arrangement. On the other hand, for example, the area from the lower part of the third surface SF3 to the area close to the second surface SF2 has a magnetization direction that is relatively close to vertical, representing a vertical radial anisotropy arrangement.

[0059] Furthermore, when the polar anisotropic magnets 1N and 1S are viewed in cross-section, there are no adhesive marks inside, and the interior is formed continuously, indicating that the polar anisotropic magnets 1N and 1S constitute a single, continuous component.

[0060] 4. Method for manufacturing a polar anisotropic magnet according to Embodiment 1, and the effects of the polar anisotropic magnet and magnet assembly. The method for manufacturing a polar anisotropic magnet according to Embodiment 1 involves arranging a magnetic force source (first magnetic force source 721 or first magnetic force source 731 for magnetization) such that the first magnetic pole faces the effective surface VSF (including a virtual effective surface VSF') (SF1), and arranging a magnetic force source (second magnetic force source 722 or second magnetic force source 732 for magnetization) such that the second magnetic pole faces the remaining three surfaces SF2, SF3, and SF4 other than the effective surface VSF (SF1), and then applying a magnetic field in a first direction to the effective surface VSF and a magnetic field in a second direction to the remaining three surfaces. Therefore, the method for manufacturing polar anisotropic magnets according to Embodiment 1 can simultaneously manufacture polar anisotropic magnets 1N and 1S that have both a horizontal polar anisotropic arrangement and a vertical radial anisotropic arrangement inside, and can significantly improve mass production compared to conventional methods for manufacturing magnet assemblies with Halbach arrangements or similar magnet assemblies.

[0061] Furthermore, by appropriately changing the positions of the magnetic sources (first magnetic source 721, second magnetic source 722, first magnetic source 731 for magnetization, second magnetic source 732 for magnetization) for each of the four surfaces SF1, SF2, and SF4, and by appropriately changing the output (strength of the applied magnetic field) of each magnetic source, the thickness of both the portion with a horizontal polar anisotropic arrangement and the portion with a vertical radial anisotropic arrangement can be appropriately changed. In other words, there is no design constraint similar to the trade-off between the radial wall thickness of the outer cylindrical body 900EX and the wall thickness of the inner cylindrical body 900IN, as in the manufacturing method of the magnet assembly 900 described in Patent Document 1.

[0062] From the above, the method for manufacturing polar anisotropic magnets according to Embodiment 1 can improve mass production efficiency, and it can also increase the design freedom for the thickness of the horizontal polar anisotropic arrangement and the thickness of the vertical radial anisotropic arrangement. In other words, it is a method for manufacturing polar anisotropic magnets that offers greater design freedom and is more economical than conventional methods.

[0063] Furthermore, in order to obtain the magnet assembly 100 of Embodiment 1, polar anisotropic magnets 1N and 1S with different magnetization directions are joined together. In this case, for example, the south pole appearing on the first surface SF1 of the polar anisotropic magnet 1N and the north pole appearing on the fourth surface SF4 of the polar anisotropic magnet 1S will attract each other, making the arrangement, joining, and bonding of multiple polar anisotropic magnets extremely easy. Therefore, this also contributes to improving mass production efficiency.

[0064] 5. Magnet assembly 100 according to Embodiment 1 Figure 11 is a diagram illustrating the magnet assembly 100 according to Embodiment 1. Figure 11(a) is a cross-sectional view of the magnet assembly 100, and Figure 11(b) is a perspective view of the magnet assembly 100.

[0065] As shown in Figure 11, the magnet assembly 100 is composed of anisotropic magnets arranged and joined together such that one magnetic pole and the other magnetic pole alternately appear on the outside. Specifically, the magnet assembly 100 is configured such that anisotropic magnets 1N and anisotropic magnets 1S are arranged alternately in a predetermined direction, and two adjacent anisotropic magnets are magnetized in opposite directions.

[0066] In other words, the magnet assembly 100 here consists of polar anisotropic magnets 1N and 1S arranged along the circumferential direction centered on axis AX, and has a roughly cylindrical shape. Here, polar anisotropic magnets 1N and 1S, which are divided into eight equal rings (N=8), are joined and bonded to each other so that their third faces SF3 and fourth faces SF4 are in contact with each other, and their first faces SF1 (effective face VSF) form the same surface (formed so that there is no gap at the joint).

[0067] [Examples of application] Figure 12 is a diagram illustrating motor 510, generator 520, and actuator 530 as application examples using polar anisotropic magnets and magnet assemblies according to each embodiment. The polar anisotropic magnets 1N and 1S obtained in Embodiment 1 and the magnet assembly 100 constructed using them are applicable to various product fields. For example, a motor equipped with a rotor including the magnet assembly 100 (see Figure 12(a)), a generator equipped with a rotor including the magnet assembly 100 (see Figure 12(b)), an actuator equipped with a rotor including the magnet assembly 100 (see Figure 12(c)), and so on can be constructed.

[0068] Although the present invention has been described above based on Embodiment 1, the present invention is not limited to Embodiment 1. It can be implemented in various forms without departing from the spirit of the invention, and for example, the following modifications are also possible.

[0069] (1) In the magnetic field forming process S20 and / or four-way magnetization process S40 of Embodiment 1, the width of the side on which the first magnetic pole of the first magnetic force source 721 or the first magnetic force source 731 for magnetization is located is approximately equal to the width of the effective surface VSF (including the virtual effective surface), but the present invention is not limited thereto. Figure 13 is a diagram illustrating a modified method for carrying out the four-way magnetization process S40. For example, as shown in Figure 13, in the four-way magnetization process S40, the width W1 on the side where the first magnetic pole of the first magnetization magnetic source 731 is located may be set to be smaller than the width W2 of the effective surface VSF. In other words, the magnetic field application surface of the first magnetization magnetic source 731 facing the effective surface VSF may be set to overlap only a part of the effective surface VSF. By doing so, it is possible to adjust the degree of density and sparseness of the magnetic flux density distribution outside the effective surface VSF, as well as the strength of the magnetic field lines.

[0070] Although Figure 13 and the above description show modified methods for implementing the four-way magnetization process S40, the same procedure may be followed in the magnetic field forming process S20. That is, in the magnetic field forming process S20, the width of the side on which the first magnetic pole of the first magnetic source 721 is located may be set to be smaller than the width of the virtual effective surface VSF'.

[0071] (2) The method for manufacturing an anisotropic magnet according to Embodiment 1 describes a method for manufacturing an anisotropic magnet that generates a high-density magnetic flux on the outside of the outer circumference of a cylinder when the anisotropic magnets are divided ring-shaped, which are part of a cylindrical magnet assembly 100, and the magnet assembly 100 is created by combining them. However, the present invention is not limited thereto. For example, in the magnetic field forming step S20 and the four-way magnetization step S40, the second surface SF2 is set as the effective surface VSF, and the remaining three surfaces other than the effective surface VSF are set as the first surface SF1, the third surface SF3, and the fourth surface SF4, and by changing the polarity of each magnetic force source and magnetization magnetic force source and the setting of the magnetic field to be applied so that lines in the molecular arrangement direction or lines in the magnetization direction are concentrated on the inner circumference side of the arc-shaped anisotropic magnet, an anisotropic magnet that can generate a high-density magnetic flux on the inside of the inner circumference of a cylinder can also be manufactured. Such anisotropic magnet can be suitably used, for example, as an outer rotor.

[0072] (3) Although the magnet assembly 100 according to Embodiment 1 was described as being substantially cylindrical, the present invention is not limited thereto. For example, as shown in Figure 14(a), it can also be a linear magnet assembly 110 or an arc-shaped magnet assembly 120. Figure 14 is a diagram shown to illustrate modified magnet assemblies 110 and 120.

[0073] (4) The method for manufacturing a polar anisotropic magnet according to Embodiment 1, the polar anisotropic magnets 1N, 1S, and the magnet assembly 100 have been described as corresponding to the magnet assembly 900 shown in Figure 3 of Patent Document 1, but the present invention is not limited thereto. For example, the method for manufacturing a polar anisotropic magnet according to Embodiment 1 can also be applied to a magnet assembly using a Halbach arrangement or to a polar anisotropic magnet applied to a magnet assembly similar to a Halbach arrangement.

[0074] (5) The method for manufacturing an anisotropic magnet and the anisotropic magnets 1N,1S according to the present invention can also be applied to a double-structured magnet unit with opposing magnetic fields. Figure 15 shows a cylindrical double-layered magnet unit 400. The cylindrical double-layered magnet unit 400 comprises an outer-circumferential magnet assembly 400EX and an inner-circumferential magnet assembly 400IN. The polar anisotropic magnets 1N, 1N', 1S, and 1S' that constitute the magnet assemblies 400EX and 400IN can also be obtained by the method for manufacturing polar anisotropic magnets of the present invention, and the polar anisotropic magnets 1N, 1N', 1S, and 1S' of the present invention can be applied to the magnet assemblies 400EX and 400IN.

[0075] On the other hand, Figure 16 shows a linear double-structured magnet unit 420. The linear double-structured magnet unit 420 comprises an upper magnet assembly 420U and a lower magnet assembly 420L, and a magnet assembly 430 positioned between them. The polar anisotropic magnets 2N, 2N', 2S, and 2S' that constitute the magnet assemblies 420U and 420L can also be obtained by the method for manufacturing polar anisotropic magnets of the present invention, and the polar anisotropic magnets 2N, 2N', 2S, and 2S' of the present invention can be applied to the magnet assemblies 420U and 420L.

[0076] (6) Although Embodiment 1 and its modifications describe a polar anisotropic magnet having four sides (four faces) in cross-section, the invention is not limited thereto. Embodiment 1 is not limited to four faces and can also be applied to polar anisotropic magnets having three or more faces. For example, in a magnet base material M1 and magnet material M2 having three triangular faces in cross-section, or a magnet base material M1 and magnet material M2 having six hexagonal faces in cross-section, it is possible to apply a magnetic field in a first direction to one face while applying magnetic fields in a second direction to the remaining faces. By doing so, a polar anisotropic magnet can be obtained in which one face has one magnetic pole (e.g., an N pole) and the other faces have other magnetic poles (e.g., S poles).

[0077] B. Manufacturing method of magnet assemblies using parallel magnetic fields and cutting technology Next, a method for manufacturing a magnet assembly using parallel magnetic fields and cutting technology will be disclosed.

[0078] [Embodiment 2] 1. Method for manufacturing a magnet assembly according to Embodiment 2 Figure 17 is a flowchart illustrating the manufacturing method of the magnet assembly according to Embodiment 2. The method for manufacturing the outer magnet assembly 100EX will be described below as Embodiment 2.

[0079] The method for manufacturing a magnet assembly according to Embodiment 2 is a method for manufacturing a cylindrical magnet assembly. As shown in Figure 17, the method for manufacturing a magnet assembly according to Embodiment 2 includes at least a powder material preparation step SS10, a magnetic field molding step SS20, a cutting step SS40, an assembly step SS60, and a magnetization step SS70 in this order. Embodiment 2 further includes a sintering and heat treatment step SS30 between the magnetic field molding step SS20 and the cutting step SS40. Furthermore, a surface treatment step SS50 is further included between the cutting step SS40 and the assembly step SS60. For reference, the materials and components input and output to the predetermined steps are shown on the right side of Figure 17.

[0080] (1) Powder material preparation process SS10 The powder material preparation process SS10 is the process of preparing the powder material PD for magnets. Existing general methods can be used to prepare the powder material for magnets. For example, assuming a neodymium magnet, raw materials such as neodymium, iron, and boron can be dissolved and solidified, and the solid material can be coarsely and finely ground using a crusher, mill, etc. to prepare the powder material PD for magnets.

[0081] (2) Magnetic field molding process SS20 Figure 18 is a diagram illustrating the magnetic field molding process SS20. Figure 18(a) is a perspective view showing the magnetic field molding process, Figure 18(b) is a perspective view of the magnet base material 10, Figure 18(c) is a cross-sectional view of the magnet base material 10 in Figure 18(b) when cut along a virtual plane PL1, and Figure 18(d) is a cross-sectional view of the magnet base material 10 in Figure 18(b) when cut along a virtual plane PL2.

[0082] The magnetic field molding process SS20 is a process for molding a "magnet base material 10" having a first main surface 11 and a second main surface 12 opposite to the first main surface 11 (see Figure 18(b)). In the figure, reference numeral 13a indicates side A, 13b indicates side B, 13c indicates side C, and 13d indicates side D. In the magnetic field molding process SS20, the powder material PD prepared in the powder material preparation process SS10 is placed inside a mold 890 corresponding to the shape of the magnet base material 10 (not shown in the figure), and a unidirectional parallel magnetic field is applied from the side corresponding to the first main surface 11 (upper side in the figure) to the side corresponding to the second main surface 12 (lower side in the figure) on the outside of the mold 890.

[0083] In terms of specific configuration, for example, a first magnetic source (not shown) is placed on the outside of the mold 890, on the side that will become the first main surface 11 when molded into the magnet base material 10 (the upper side of the mold 890 in the figure), such that its north pole faces the other side. A second magnetic source (not shown) is placed on the side that will become the second main surface 12 (the lower side of the mold 890 in the figure), such that its south pole faces the other side. Then, the first and second magnetic sources are activated to apply a uniform magnetic field to the entire first and second main surfaces 11 and 2, perpendicular to the first and second main surfaces 12, such that the magnetic field lines are parallel to each other, and the magnetic flux density is the same (see Figure 18(a)). Although a magnetic field directed from the top to the bottom of the figure is shown as an example here, the direction of the magnetic field may be reversed.

[0084] When the above-described magnetic field is applied while pressure is being applied inside the mold 890, each molecule of the powder material PD aligns in the direction of the magnetic field and orients along the direction of the magnetic field, and a magnet base material 10 having a shape corresponding to the shape of the mold 890 is formed (see Figure 18(b)). The first main surface 11 is substantially planar. The second main surface 12 is also substantially planar and substantially parallel to the first main surface. However, it is not limited to this. Inside the magnet base material 10, as shown by the dashed lines in Figures 18(c) and 18(d), the molecular orientation is uniformly oriented in a direction perpendicular to the first main surface 11 and the second main surface 12. Once the molecular orientation is aligned here, the material will be strongly magnetized along this alignment direction by performing the magnetization process SS70 described later. In this specification, the orientation of each powder particle in the powder material PD that has been aligned by performing the magnetic field molding process SS20 (the direction of molecular orientation) is sometimes referred to as the "easy magnetization axis".

[0085] (3) Sintering and heat treatment process SS30 The sintering and heat treatment process SS30 involves sintering and heat treating the magnet base material 10 obtained in the magnetic field molding process SS20. During the sintering and heat treatment process SS30, the binder contained in the magnet base material 10 is vaporized and removed by the heat, increasing the purity of the magnetic material. Furthermore, although the magnet base material M1 may be slightly magnetized internally as a result of magnetic field molding, it is possible to demagnetize it through the sintering and heat treatment.

[0086] (4) Cutting process SS40 (4-1) Cutting out the magnet base material piece 20 Figure 19 is a diagram illustrating the cutting process SS40. Figure 19(a) is a right side view of the magnet base material 10 before cutting, viewed from a direction perpendicular to side C 13c. The solid line (virtual line) drawn on the cross-section of the magnet base material 10 is the cut line, which is the line along which the cutting is performed; it is essentially a marking line. When the cutting is performed along the cut line, the outline (outer surface) of the magnet base material piece 20, which will be described later, will be exposed to the outside. Figure 19(b) is a perspective view showing the magnet base material piece 20 obtained after performing the cutting process SS40.

[0087] The cutting process SS40 is a process in which the magnet base material 10 is cut along the cut line described above to cut out the magnet base material piece 20, which will be described later. The cutting process SS40 is performed here by wire cutting. When performing wire cutting, it is preferable to cut while cooling. Note that the processing method introduced in the cutting process SS40 is not limited to wire cutting; for example, water jet cutting or machining may also be used. With these methods, unlike conventional magnet assembly manufacturing methods, it is not necessary to develop a new mold each time the specifications are changed, and the specifications can be changed using only conventional general magnet manufacturing equipment.

[0088] (4-2) Setting the cut line Here, the surface that will become the outer diameter surface of the magnet assembly when assembled is defined as "planned outer diameter surface 20EX," and the surface that will become the inner diameter surface is defined as "planned inner diameter surface 20IN." Note that the corresponding cut lines before cutting are indicated by adding an apostrophe ('') to the same symbol. In Embodiment 2, the cutting process is performed so that the planned outer diameter surface 20EX and / or planned inner diameter surface 20IN that are cut out are flat. By making the planned outer diameter surface 20EX and the planned inner diameter surface 20IN flat, the cutting work becomes simpler compared to when they are curved, and it is expected that productivity can be increased while ensuring high precision. Furthermore, in Embodiment 2, the planned outer diameter surface 20EX and the planned inner diameter surface 20IN are parallel to each other.

[0089] As shown in Figure 19(a), the cut line 20EX' of the planned outer diameter surface is set to have an inclination of angle θ1 with respect to the first main surface 11. Similarly, the cut line 20IN' of the planned inner diameter surface is set to have an inclination of angle θ2 with respect to the first main surface 11. Embodiment 2 illustrates the case where the planned outer diameter surface and the planned inner diameter surface are parallel, so the relationship is θ1 = θ2 here. In this specification, the cut line is set based on the first main surface 11; however, in practice, the cut line may be set based on either the first main surface 11 or the second main surface 12. Therefore, in this specification, it is possible to substitute "first main surface 11" with "second main surface 12," and such cases are also included within the technical scope of the present invention.

[0090] (4-3) Cut line parameters In the cutting process SS40 of Embodiment 2, the angles θ1 and θ2 with respect to the first main surface 11 are set to a range greater than 45 degrees and less than 90 degrees, and under these settings, the magnet base material 10 is cut along the cut line 20EX' on the planned outer diameter surface and the cut line 20IN' on the planned inner diameter surface. In other words, in the cutting process SS40 of Embodiment 2, the cut line 20EX' of the planned outer diameter surface is set to a range greater than 0 degrees and less than 45 degrees with respect to the easy magnetization axis (direction of the dashed line) (θ3), and the cut line 20IN' of the planned inner diameter surface is set to a range greater than 0 degrees and less than 45 degrees with respect to the easy magnetization axis (θ4). Under these settings, the magnet base material 10 is cut along the cut line 20EX' of the planned outer diameter surface and the cut line 20IN' of the planned inner diameter surface (see Figure 19(a)). By setting θ1, θ2, θ3, and θ4 in this way, it is possible to manufacture a magnet assembly (outer magnet assembly) with a horizontal polar anisotropic arrangement.

[0091] (4-4) Cutting out the magnet base piece 20 Next, after the cut lines are determined as described above, the magnet base material 10 is cut along the cut line 20EX' on the planned outer diameter surface, and the magnet base material 10 is cut along the cut line 20IN' on the planned inner diameter surface, thereby cutting out a magnet base material piece 20 having at least the planned outer diameter surface 20EX and the planned inner diameter surface 20IN on its outer surface (see Figure 19(b)).

[0092] As shown in Figure 19(b), the magnet base material piece 20 cut out in the cutting process SS40 has a planned outer diameter surface 20EX and a planned inner diameter surface 20IN on its outer surface, as well as joining surfaces 21 and 24 that will be joined to each other in the subsequent assembly process SS60. In the example of Embodiment 2, the joining surface 21 is the part that was the same surface as the first main surface 11 of the magnet base material 10 before the cutting process SS40. The joining surface 24 is a surface that has newly appeared after being cut along a separate cut line. The magnet base material piece 20 also has a surface 22 on one end in the longitudinal direction and a surface 23 on the other end. Note that in Figure 19, there are multiple magnet base material pieces 20 -1 ,20 -2 ,20 -3 ,20 -4 Although an example of cutting out ,, is shown, cutting out a single character is also included in this embodiment of the cutting process SS40.

[0093] (5) Surface treatment process SS50 The surface treatment process involves applying a rust-preventive surface treatment (e.g., nickel plating, bright chromate treatment, electrodeposition coating, electrostatic coating, etc.) to the magnet base material piece 20.

[0094] (6) Assembly process SS60 Figure 20 is a diagram illustrating the assembly process SS60. Figure 20(a) shows the magnet base material pieces 20 when four pieces are combined. Figure 20(b) is a perspective view showing the magnet base material assembly 40EX. For reference, the area indicated by the dashed line SA in Figure 20(b) is the same as in Figure 20(a).

[0095] The assembly process SS60 is a process of assembling a plurality of magnet base pieces 20 together to form a magnet base assembly 40EX. Specifically, a plurality of magnet base pieces 20 obtained by the cutting process SS40 are prepared (see Fig. 19(b)), and the joining side surfaces 21, 24 of the magnet base pieces 20 are joined and adhered to each other. At this time, the adjacent planned outer diameter surfaces 20EX and the adjacent planned inner diameter surfaces 20IN are joined at the joint without a gap (it may be angled). By doing so, a continuous outer peripheral surface and inner peripheral surface can be formed by combining a plurality of magnet base pieces 20.

[0096] As an example, the case of combining four magnet base pieces 20 in Fig. 19(b) will be described (see Fig. 20(a)). From the left side, first, with the surface 22 on one end side facing forward, the magnet base piece 20 <s -1 is placed. Next to its right, with the one end side and the other end side in the longitudinal direction swapped so that the 23 on the other end side faces forward, the magnet base piece 20 <s -2 is placed. At this time, the joining side surface 24 of the magnet base piece 20 <s -1 and the joining side surface 24 of the magnet base piece 20 <s -2 are joined. Then, next to its right, with the surface 22 on one end side facing forward, the magnet base piece 20 <s -3 is placed. At this time, the joining side surface 21 of the magnet base piece 20 <s -2 and the joining side surface 21 of the magnet base piece 20 <s -3 are joined. Then, next to its right, with the one end side and the other end side in the longitudinal direction swapped so that the 23 on the other end side faces forward, the magnet base piece 20 <s -4 is placed. At this time, the joining side surface 24 of the magnet base piece 20 <s -3 and the joining side surface 24 of the magnet base piece 20 <s -4 are joined. In the above manner, four magnet base pieces 20 <s -1 ~20<s -4 can be assembled by combining them. By repeating such assembly, the magnet base assembly 40EX shown in Fig. 20(b) can be obtained.

[0097] (7) Magnetization process SS70 Figure 21 is a diagram illustrating the magnetization process SS70. Figure 21(a) is a cross-sectional view showing the arrangement of the magnetic sources 840N and 840S during magnetization, and Figure 21(b) is a cross-sectional view of the magnet assembly 100EX after the magnetization process has been carried out.

[0098] The magnetization process SS70 is a process in which a predetermined magnetic field is applied to the magnet base material assembly 40EX from outside the magnet base material assembly 40EX at a predetermined position to magnetize the magnet base material assembly 40EX. For example, as shown in Figure 21(a), four magnetic force sources 840N and 840S, each composed of a magnetizing yoke, are arranged at equal angles with alternating polarities along the outer diameter surface (more precisely, the circumference around the central axis) of the magnet base material assembly 40EX. The poles of the magnetic force sources 840N and 840S are positioned at the joint (indicated by P1 and P2 in Figure 23(a)) such that they approach the joint surfaces 21 and 24 as they move radially outward from the central axis. Then, the magnetic sources 840N and 840S are activated at a predetermined timing and output to apply a magnetic field to the magnet base material assembly 40EX. In this way, the inside of the magnet base material assembly 40EX can be magnetized according to the orientation direction (easy magnetization axis) of the molecules formed in the magnetic field molding process SS20. As a result, the magnet assembly 100EX is magnetized in the direction (magnetization direction) shown in Figure 21(b).

[0099] A magnet assembly 100EX can be obtained by performing at least the above steps: the forming process in a magnetic field SS20, the cutting process SS40, the assembly process SS60, and the magnetization process SS70.

[0100] 2. Magnet Assembly 100EX Next, we will describe the magnet assembly 100EX obtained by the manufacturing method of the magnet assembly according to Embodiment 2. As shown in Figure 21(b), the magnet assembly 100EX has a substantially planar outer diameter surface and an inner diameter surface, and comprises magnet blocks 50 that are magnetized at a predetermined angle (θ3, θ4) with respect to the outer diameter surface and the inner diameter surface and parallel to a single direction, and multiple (in this case, N) magnet blocks 50 are joined to each other via surfaces other than the outer diameter surface and the inner diameter surface (joining surfaces 21, 24 in Figure 20(a)). Specifically, the magnet assembly 100EX is made up of N magnet blocks 50 joined together, and is constructed as a cylindrical shape with an N-sided polygon formed by the magnet assembly 100EX on both the outer and inner diameter sides. The magnet assembly 100EX shown in Figure 21(b) is an example where nps (number of like poles) = 2, npNS (number of opposite poles) = 2, and ns (number of sets, a natural number of 1 or more), and ns = 4, so N = 2·2·4 = 16.

[0101] Furthermore, between the assembly process SS60 and the magnetization process SS70, a cylindricalization process (not shown in the diagram) may be performed to cylindricalize the entire magnet base material assembly 40EX, which is roughly N-shaped and cylindrical, by grinding the corners of the outer diameter surface or by attaching a protective film or the like to the outer surface. In this case, the magnet assembly 100EX will also become cylindrical accordingly. Although the magnet assembly 100EX was described above as a cylindrical shape with a substantially flat outer diameter surface and a substantially N-sided polygon, magnet assemblies in which the final outer diameter surface is curved or the entire shape is substantially cylindrical after undergoing the cylindricalization process are also included as one aspect of this embodiment, since they were originally substantially flat and substantially N-sided.

[0102] 3. Effects of the manufacturing method for magnet assemblies according to Embodiment 2 The manufacturing method for the magnet assembly of Embodiment 2 involves applying a unidirectional parallel magnetic field from the side corresponding to the first main surface 11 to the side corresponding to the second main surface 12 to form the magnet base material 10, then cutting the magnet base material 10 by setting the cut line 20EX' of the planned outer diameter surface to have an inclination of angle θ1 with respect to the first main surface 11, and cutting the magnet base material 10 by setting the cut line 20IN' of the planned inner diameter surface to have an inclination of angle θ2 with respect to the first main surface 11 to cut out magnet base material pieces 20, and then assembling the magnet base material assembly 40EX by combining the magnet base material pieces 20 with respect to each other and performing magnetization to obtain a magnet assembly 100EX.

[0103] In other words, once a magnet base material 10 with a unidirectional molecular orientation (easy magnetization axis) is obtained, the design and model of the magnet assembly can be changed by modifying the cutting angle, shape, etc., in the cutting process SS40. That is, the magnetization direction, thickness, shape, etc. can be changed as appropriate simply by changing how the cutting lines are set. For this reason, the manufacturing method of the magnet assembly of the present invention offers a high degree of design freedom. From another perspective, the processes up to the powder material preparation process SS10, the magnetic field molding process SS20, and the sintering and heat treatment process SS30 can be standardized and shared. By simply changing the setting of the cut line in the cutting process SS40, it is possible to produce both the outer magnet assembly 100EX and the inner magnet assembly 100IN. Therefore, there is no need for large-scale process changes for each product variation. Furthermore, unlike conventional methods, there is no need to prepare a dedicated mold for each product variation, and the SS40 cutting process itself can be performed using conventional general magnet manufacturing equipment. In particular, the manufacturing method of Embodiment 2 is useful even when utilizing equipment that constructs sintered magnets by so-called unipolar manufacturing, and because it is easy to change the design and offers a high degree of flexibility, it leads to reduced development costs and shorter development periods, making it useful even in the development and prototyping stages. Thus, the method for manufacturing the magnet assembly of the present invention is more economical than conventional methods.

[0104] Furthermore, even if the radial thickness of the magnet assembly 100EX to be assembled is thin, the cutting angle, cut shape, etc. can be changed as appropriate, and the magnetization direction can be freely controlled even with a thin magnet assembly. For example, a magnet assembly with a thickness T2 of about 1 mm to 2 mm, which was difficult to achieve with conventional manufacturing methods, can be realized using the manufacturing method of this embodiment (see Figure 32). Therefore, in this respect as well, the design freedom is greater than in the conventional method. Furthermore, since the material is not sintered or heat-treated in the same thin state as in conventional methods, there is no risk of damage during the sintering and heat-treatment process. As a result, the yield is higher than conventional methods, making it highly economical.

[0105] Furthermore, since the parts handled in the assembly process SS60 are unmagnetized magnet base material pieces 20, they are assembled without attractive or repulsive forces. For example, this eliminates the problem of attractive and repulsive forces between adjacent magnets, which is a problem when assembling magnets in a Halbach arrangement in the past. This makes the process very easy to manufacture and highly suitable for mass production.

[0106] Therefore, the magnet assembly manufacturing method of Embodiment 2 provides a magnet assembly manufacturing method that offers greater design flexibility and is more economical than conventional methods.

[0107] Furthermore, conventionally, as shown in Figure 32, the orientation direction of molecules (easy magnetization axis) can be affected by variations in the arrangement of the magnetic source, the magnitude of the output of the magnetic source, and the output method. Due to these variations, individual differences in magnetization direction are likely to occur in each product, resulting in variations in quality. However, the manufacturing method of the magnet assembly in Embodiment 2 simply applies a parallel magnetic field in a single direction, resulting in a uniform molecular orientation direction (easy magnetization axis) inside, which suppresses variations and makes it easier to maintain high quality.

[0108] [Embodiment 3] Figure 22 is a cross-sectional view showing the cutting process SS40 of Embodiment 3. Figure 22(a) is a right side view of the magnet base material 10 before cutting, viewed from a direction perpendicular to side C 13c. Figure 19(b) is a cross-sectional view showing the magnet base material piece 30 obtained after performing the cutting process SS40. Figure 23 is a cross-sectional view shown to explain the assembly process SS60 of Embodiment 3. Figure 23(a) shows four magnet base material pieces 30 combined. Figure 23(b) is a perspective view showing the magnet base material assembly 40IN. Figure 24 is a cross-sectional view of the magnet assembly 100IN after performing the magnetization process SS70 of Embodiment 3. In the figures, reference numeral 30EX indicates the planned outer diameter surface, and reference numeral 30IN indicates the planned inner diameter surface. For components whose basic configuration and characteristics are the same as those in Embodiment 2, the reference numerals used in Embodiment 2 will be used, and their explanation will be omitted here.

[0109] The manufacturing method for the magnet assembly 100IN according to Embodiment 3 basically has the same configuration as the manufacturing method for the magnet assembly 100EX according to Embodiment 2, but differs from the manufacturing method for the magnet assembly 100EX according to Embodiment 2 in the setting of the cutting angle, shape, etc. in the cutting process SS40.

[0110] In other words, as shown in Figure 22(a), in the cutting process SS40, the angle θ1 of the cut line 30EX' of the planned outer diameter surface with respect to the first main surface 11, and the angle θ2 of the cut line 30IN' of the planned inner diameter surface with respect to the first main surface 11 are set to within the range of 0 degrees or more and less than 45 degrees, and under these settings, the magnet base material 10 is cut along the cut line 30EX' of the planned outer diameter surface and the cut line 30IN' of the planned inner diameter surface. In other words, the cut line 30EX' on the planned outer diameter surface and the cut line 30IN' on the planned inner diameter surface are set to be within a range of more than 45 degrees and less than or equal to 90 degrees with respect to the easy magnetization axis (direction of the dashed line), and under these settings, the magnet base material 10 is cut along the cut line 30EX' on the planned outer diameter surface and the cut line 30IN' on the planned inner diameter surface.

[0111] The magnet base material piece 30 obtained after the cutting process SS40 is as shown in Figure 22(b). Subsequently, by performing the assembly process SS60 in the same manner as in Embodiment 2, a magnet base material assembly 40IN as shown in Figure 23(b) can be obtained. Note that Figure 23(a) corresponds to Figure 20(a), and Figure 23(b) corresponds to Figure 20(b). Subsequently, by performing the magnetization process SS70, a magnet assembly 100IN as shown in Figure 24 can be obtained.

[0112] In the manufacturing method for the magnet assembly 100IN according to Embodiment 3, since the angle of the cut line is set as described above, it is possible to manufacture a magnet assembly (inner circumference magnet assembly 100IN) with a vertically polar anisotropic arrangement in which the magnetization direction is closer to the direction perpendicular to the outer diameter surface. Furthermore, according to the manufacturing method for the magnet assembly 100IN according to Embodiment 3, it is also possible to configure it so that the magnetization direction is at a 90-degree angle to the outer diameter surface (so that the magnetization direction coincides with the radial direction).

[0113] The manufacturing method for the magnet assembly 100IN according to Embodiment 3 has basically the same configuration as the manufacturing method for the magnet assembly 100EX according to Embodiment 2, except for the setting of the cutting angle, shape, etc. in the cutting process SS40. Therefore, it similarly possesses the effects of the manufacturing method for the magnet assembly 100EX of Embodiment 2.

[0114] [Embodiment 4] By combining the magnet assembly 100EX obtained by Embodiment 2 and the magnet assembly 100IN obtained by Embodiment 3, a composite magnet assembly 100 similar to the magnet assembly 900 described in Patent Document 1 can be obtained (see Figure 30).

[0115] As shown in Figure 30, the composite magnet assembly 100 is made up of N magnet blocks 50, 60 (see Figures 21(b) and 24) joined together, and is configured as a cylindrical shape with an N-sided polygon formed by the magnet assembly on both the outer and inner sides. Here, if we assume that nps = 2, where nps is the number of poles, npNS = 2, where npNS is the number of poles opposite to poles, and ns is the number of sets (a natural number greater than or equal to 1), then N is a natural number that satisfies the relationship N = nps·npNS·ns.

[0116] (1) The composite magnet assembly 100 comprises a first-mode magnet assembly 100EX obtained by Embodiment 2, in which the angle of the magnetization direction with respect to the outer diameter surface and inner diameter surface of each magnet block 50 is a first angle (an angle close to 0 degrees), and a second-mode magnet assembly 100IN obtained by Embodiment 3, in which the angle of the magnetization direction with respect to the outer diameter surface and inner diameter surface of each magnet block 60 is a second angle (an angle close to 90 degrees), which is a different angle from the first angle. The composite magnet assembly 100 is configured such that the magnet assembly 100EX of the first embodiment is positioned on the side that will become the effective H magnetic flux surface 100H of the composite magnet assembly 100, and the magnet assembly 100IN of the second embodiment is positioned on the side that will become the effective V magnetic flux surface 100V of the composite magnet assembly, and they are joined together (see Figure 30). Here, "effective H magnetic flux surface" refers to the outer surface of the composite magnet assembly 100 where the magnetization direction in the interior directly beneath that surface is close to the horizontal (H) direction with respect to the outer surface. Also, "effective V magnetic flux surface" refers to the outer surface of the composite magnet assembly 100 where the magnetization direction in the interior directly beneath that surface is close to the perpendicular (V) direction with respect to the outer surface. The example in Figure 30 shows a cylindrical composite magnet assembly 100 in which the outer surface is set as the effective H magnetic flux surface 100H and the inner surface is set as the effective V magnetic flux surface 100V. Such a composite magnet assembly 100 can be suitably used as an inner rotor.

[0117] Here, the first angle (θ) 10 )" is the angle θ between the tangent at the position of the magnetic pole appearing on the outer surface (outer diameter surface) of the magnet assembly 100EX and the magnetization direction of the adjacent magnet block located directly below the position of that magnetic pole. 10 This refers to the following. In Figure 21(b), for example, the magnetic block 50 -4 and magnetic block 50 -5A magnetic pole N appears on the outer surface side of the joint, and the θ shown in the figure is at the position of this magnetic pole N. 10 This corresponds to the first angle. Similarly, "the second angle (θ) 20 )" is the angle θ between the tangent at the position of the magnetic pole appearing on the outer surface (outer diameter surface) of the magnet assembly 100IN and the magnetization direction of the adjacent magnet block located directly below the position of that magnetic pole. 20 This refers to the magnetic block 60 shown in Figure 24. -5 and magnetic block 60 -6 A magnetic pole N appears on the outer surface side of the joint, and the θ shown in the figure is at the position of this magnetic pole N. 20 This corresponds to the second angle. Although the above explanation was based on the outer circumferential surface (outer diameter surface), the same definition applies when based on the inner circumferential surface (outer diameter surface).

[0118] (2) The composite magnet assembly 100 described above as an example is a magnet assembly of the type in which the outer surface is set as the effective H magnetic flux surface 100H, but Embodiment 4 is not limited to this. For example, the first angle θ 10 Let the first angle be close to 90 degrees, and set the second angle θ 20 By setting the angle close to 0 degrees, the inner circumferential surface can be set as the effective H magnetic flux surface, thereby constructing a different type of composite magnet assembly (not shown). Such a composite magnet assembly can be suitably used as an outer rotor.

[0119] [Embodiment 5] Figure 25 is a flowchart illustrating the manufacturing method of the magnet assembly and the manufacturing method of the polar anisotropic magnet according to Embodiment 5. Figure 26 is a diagram illustrating the sub-assembly process SS80. Figure 27 is a diagram illustrating the four-way magnetization process SS85. The components indicated by reference numerals 45 and 3 in Figure 27 represent components in a magnetized state. For components whose basic configuration and characteristics are the same as those in Embodiments 1 to 4, the reference numerals from Embodiments 1 to 4 are used, and their explanations are referred to therein, omitting the explanation in Embodiment 5.

[0120] The method for manufacturing a magnet assembly according to Embodiment 5 differs from the method described in the method for manufacturing a magnet assembly according to Embodiment 3 in the scope and manner of the assembly and magnetization processes performed after the cutting process.

[0121] As shown in Figure 25, the method for manufacturing a magnet assembly according to Embodiment 5 includes at least a powder material preparation step SS10, a magnetic field molding step SS20, a cutting step SS40, a sub-assembly step SS80, and a four-way magnetization step SS85, in this order. Embodiment 5 further includes a magnet assembly step SS90 after the four-way magnetization step SS85. A surface treatment step SS50 may be performed between the cutting step SS40 and the sub-assembly step SS80, or between the sub-assembly step SS80 and the four-way magnetization step SS85.

[0122] The powder material preparation step SS10, the magnetic field molding step SS20, and the cutting step SS40 are the same as those steps in Embodiment 3.

[0123] The sub-assembly process SS80 is a process of assembling a magnet base material subassembly 45 having four faces by combining at least four magnet base material pieces 20, 30. In Embodiment 5, the assembly process SS60 described in Embodiment 3 is composed of this sub-assembly process SS80. As shown in Figure 26, in the sub-assembly process SS80, horizontal magnet base material pieces 20, cut in the cutting process SS40 with angles θ1 and θ2 set to be within the range of more than 45 degrees and less than 90 degrees, are placed on the side of the magnet base material subassembly 45 that will be the effective surface VSF (referring to the surface among the four surfaces (cross-sectional view) constituting the magnet base material subassembly 45 that should generate concentrated magnetic flux). Vertical magnet base material pieces 30, cut in the cutting process SS40 with angles θ1 and θ2 set to be within the range of 0 degrees or more and less than 45 degrees, are placed on the side opposite to the effective surface VSF. These are then combined and joined / bonded to obtain the magnet base material subassembly 45. At this stage, the magnetic base material pieces 20 and 30 are not magnetized, and no repulsive or attractive forces are generated between them, making it easy to combine, join, or bond the magnetic base material pieces 20 and 30 together.

[0124] As shown in Figure 27, in the four-way magnetization process SS85, a magnetic field in a first direction is applied to the effective surface VSF of the magnet base material subassembly 45, and magnetic fields in a second direction are applied to the remaining three surfaces, surrounding the magnet base material subassembly 45, thereby magnetizing the magnet base material subassembly 45. In the example in Figure 27, a positive magnetic field generated from the first magnetization magnetic field source 731 is applied to the first surface SF1, which is the effective surface VSF of the magnet base material subassembly 45, and negative magnetic fields generated from the second magnetization magnetic field sources 732b, 732a, and 732c are applied to the remaining second surface SF2, third surface SF3, and fourth surface SF4, respectively, thereby obtaining a polar anisotropic magnet 3N that emits positive polarity magnetic field lines from the effective surface VSF. Furthermore, by appropriately switching the polarity of the first and second directions, which are the directions in which the magnetic field is applied, a polar anisotropic magnet 3S in which the polarity of the magnetic field lines emanating from the effective surface VSF of the polar anisotropic magnet is reversed can also be obtained as appropriate.

[0125] For a detailed explanation of the four-way magnetization process SS85 other than those described above, please refer to the explanation of the four-way magnetization process S40 in Embodiment 1, and omit the explanation here. For reference, the magnetization process described in Embodiment 3 is composed of this four-way magnetization process SS85 in Embodiment 5.

[0126] By following the above steps, a polar anisotropic magnet 3 can be obtained (the above describes the method for manufacturing a polar anisotropic magnet according to Embodiment 5).

[0127] The magnet assembly process SS90 is a process of assembling a magnet assembly by combining the polar anisotropic magnets 3N and 3S obtained in the four-way magnetization process SS85. For example, polar anisotropic magnets 3N and 3S, whose magnetic field lines radiating from the effective surface VSF have different polarities from each other, are joined or bonded together on their sides. In this case, since the magnetic poles on the sides of adjacent polar anisotropic magnets 3N and 3S are opposite poles (N pole and S pole), they are attracted to each other during joining or bonding, making assembly very easy. By going through the above process, a cylindrical (annular) magnet assembly 100' shown below in Figure 25 can be obtained (the above is the method for manufacturing a magnet assembly according to Embodiment 5).

[0128] The method for manufacturing a magnet assembly and a polar anisotropic magnet according to Embodiment 5 combines the acquisition of magnet base material pieces 20 and 30 by parallel magnetic field and cutting technology of Embodiments 2 to 4 with magnetization by four-way magnetization of Embodiment 1. Therefore, it is possible to simultaneously enjoy the advantages of acquiring magnets by parallel magnetic field and cutting technology of Embodiments 2 to 4 (such as no mold required and high design flexibility) and the advantages of four-way magnetization of Embodiment 1 (such as being freed from design constraints on thickness and being able to mass-produce polar anisotropic magnets having horizontal and vertical polar anisotropic arrangements).

[0129] [Examples of application] The magnet assembly 100EX obtained in Embodiment 2, the magnet assembly 100IN obtained in Embodiment 3, and the composite magnet assembly 100 according to Embodiment 4, which is constructed using them, are applicable to various product fields. For example, a motor equipped with a rotor including the composite magnet assembly 100 (see Figure 12(a)), a generator equipped with a rotor including the composite magnet assembly 100 (see Figure 12(b)), an actuator equipped with a rotor including the composite magnet assembly 100 (Figure 12(c)), and so on can be constructed. While it is preferable to use the composite magnet assembly 100 as a rotor on the rotating side, it can also be used as a stator on the stationary side. In this case, the term "rotor" in this specification can be read as "stator," and the configuration in this case is also included within the technical scope of the present invention.

[0130] Although the present invention has been described above based on the embodiments described above, the present invention is not limited to the embodiments described above. It can be implemented in various forms without departing from the spirit of the invention, and for example, the following modifications are also possible.

[0131] (1) Although the magnet assemblies 100EX and 100IN obtained by carrying out Embodiments 2 and 3 have been described assuming a cylindrical shape, the present invention is not limited thereto. It can also be applied to linear magnet assemblies (not shown).

[0132] For example, in embodiments 2 and 3, the lengths of the cut lines 20EX' on the planned outer diameter surface and the cut lines 20IN' on the planned inner diameter surface are set to be the same, and the surfaces constituting the magnet blocks that are to become the effective H magnetic flux surfaces of the composite magnet assembly are arranged so that they are substantially on the same plane between adjacent magnet blocks, thereby creating a linear magnet assembly. In this case, the only difference from embodiments 2, 3, and 4 is that it is not cylindrical, but the other configurations can be implemented similarly. By combining the linear magnet assembly of the first embodiment and the magnet assembly of the second embodiment, for example, the linear composite magnet assembly 130 shown in Figure 29(a) can be obtained.

[0133] (2) A linear motor structure 550 including a linear composite magnet assembly 130 can also be constructed by using a linear composite magnet assembly 130 (see Figures 28, 29(b), and 29(c)). In this case, the term rotor in this specification can be read as mover. Figure 28 is a schematic diagram illustrating a modified linear motor structure 550 of the application example. Figure 29 is a diagram illustrating the details of the linear motor structure 550. Figure 29(b) shows a cross-sectional view of the linear motor structure 550 shown in Figure 28 when cut by a plane parallel to the longitudinal axis, and Figure 29(c) is a cross-sectional view when cut along line AA in Figure 29(b). In the figures, reference numeral 552 denotes the rail, 553 denotes the moving body, 553a denotes the coil portion of the moving body, 70 and 80 denotes the magnet block, 130EX denotes the outer diameter magnet assembly, 130IN denotes the inner diameter magnet assembly, and 130 denotes the composite magnet assembly. [Explanation of Symbols]

[0134] 1N, 1N', 1S, 1S', 2N, 2N', 2S, 2S', 3, 3N, 3S…Poly anisotropic magnets, 5…Material before magnetization, 6…Soft magnetic material, 10…Magnet base material, 11…First main surface, 12…Second main surface, 13a…A side, 13b…B side, 13c…C side, 13d…D side, 20, 30…Magnet base material pieces, 20EX, 30EX…Planned outer diameter surface, 20EX', 30EX'…Cut line of planned outer diameter surface, 20IN, 30IN ...Planned inner diameter surface, 20IN', 30IN'...Cut line of planned inner diameter surface, 21, 24...Joining side surface, 22...Face on one end, 23...Face on the other end, 40EX, 40IN...Magnet base material assembly, 45...Magnet base material sub-assembly, 50, 60, 70, 80...Magnet block, 100, 100', 100EX, 100IN, 110, 120, 130EX, 130IN, 400EX, 400IN, 420L, 420U, 4 30, 900, 900EX, 900IN…Magnet assemblies, 100H…Effective H magnetic flux surface, 100V…Effective V magnetic flux surface, 130…Composite magnet assemblies, 400…Double-structured cylindrical magnet unit, 420…Double-structured linear magnet unit, 510…Motor, 520…Generator, 530…Actuator, 550…Linear motor structure, 552…Rail, 553…Moving body, 553a…Movement Body coil section, 710...Mold, 721...First magnetic source, 722, 722a, 722b, 722c...Second magnetic source, 731...First magnetic source for magnetization, 732, 732a, 732b, 732c...Second magnetic source for magnetization, 890, 810...Mold, 810a...Inside of mold, 820N, 820S, 830N, 830S, 840N, 840S...Magnetic source, 905, 906, 907, 908...Magnet, 905', 906'...Base material

Claims

1. A method for manufacturing a cylindrical magnet assembly, A powder material preparation process for preparing powder materials for magnets, A magnetic field molding process for forming a "magnet base material" having a first main surface and a second main surface opposite to the first main surface, comprising: placing the powder material inside a mold corresponding to the shape of the magnet base material; and applying a unidirectional parallel magnetic field from the side of the mold corresponding to the first main surface to the side corresponding to the second main surface to form the magnet base material; When assembled as a magnet assembly, the surface that will become the outer diameter surface of the magnet assembly is defined as the "planned outer diameter surface" and the surface that will become the inner diameter surface is defined as the "planned inner diameter surface". The cutting process involves setting the cut line of the planned outer diameter surface to have an inclination of angle θ1 with respect to the first main surface, cutting the magnet base material along the cut line of the planned outer diameter surface, and setting the cut line of the planned inner diameter surface to have an inclination of angle θ2 with respect to the first main surface, cutting the magnet base material along the cut line of the planned inner diameter surface, thereby cutting out a magnet base material piece having at least the planned outer diameter surface and the planned inner diameter surface as its outer surface. An assembly process for assembling a magnet base material assembly by combining multiple magnet base material pieces with each other, A magnetization step in which a predetermined magnetic field is applied to the magnet base material assembly from outside the magnet base material assembly at a predetermined position to magnetize the magnet base material assembly, A method for manufacturing a magnet assembly, characterized by including the following in this order.

2. In the method for manufacturing a magnet assembly according to claim 1, A method for manufacturing a magnet assembly, characterized in that the cutting process is performed such that the planned outer diameter surface and / or the planned inner diameter surface cut out in the cutting step become flat.

3. In the method for manufacturing a magnet assembly according to claim 1 or 2, A method for manufacturing a magnet assembly, characterized in that the cutting step is carried out by wire cutting.

4. In the method for manufacturing a magnet assembly according to any one of claims 1 to 3, A method for manufacturing a magnet assembly, characterized in that the angles θ1 and θ2 in the cutting step are each within the range of more than 45 degrees and less than 90 degrees.

5. In the method for manufacturing a magnet assembly according to any one of claims 1 to 3, A method for manufacturing a magnet assembly, characterized in that the angles θ1 and θ2 in the cutting step are each within the range of 0 degrees or more and less than 45 degrees.

6. In the method for manufacturing a magnet assembly according to any one of claims 1 to 3, When the orientation of each powder in the powder material aligned by the aforementioned magnetic field molding process is defined as the "easy magnetization axis", A method for manufacturing a magnet assembly, characterized in that, in the cutting step, the cut line of the planned outer diameter surface and the cut line of the planned inner diameter surface are set to a range greater than 0 degrees and less than 45 degrees with respect to the easy magnetization axis, and the magnet base material is cut along the cut line of the planned outer diameter surface and the cut line of the planned inner diameter surface.

7. In the method for manufacturing a magnet assembly according to any one of claims 1 to 3, When the orientation of each powder in the powder material aligned by the aforementioned magnetic field molding process is defined as the "easy magnetization axis", A method for manufacturing a magnet assembly, characterized in that, in the cutting step, the cut line of the planned outer diameter surface and the cut line of the planned inner diameter surface are set within a range of more than 45 degrees and less than or equal to 90 degrees with respect to the easy magnetization axis, and the magnet base material is cut along the cut line of the planned outer diameter surface and the cut line of the planned inner diameter surface.

8. In the method for manufacturing a magnet assembly according to any one of claims 1 to 3, The assembly process is a sub-assembly process in which a magnet base material sub-assembly having four faces is assembled by combining at least four of the magnet base material pieces. In the sub-assembly process, when the surface on which magnetic flux should be concentrated is designated as the effective surface among the four surfaces, a horizontal magnet base material piece is placed on the side of the magnet base material subassembly that is the effective surface, with angles θ1 and θ2 in the cutting process set to be within the range of more than 45 degrees and less than 90 degrees, and a vertical magnet base material piece is placed on the side opposite to the effective surface, with angles θ1 and θ2 in the cutting process set to be within the range of 0 degrees or more and less than 45 degrees. The magnetization step is a four-way magnetization step in which a magnetic field in a first direction is applied to the effective surface of the magnet base material subassembly and a magnetic field in a second direction is applied to the remaining three surfaces of the magnet base material subassembly, surrounding the magnet base material subassembly. A method for manufacturing a magnet assembly, characterized by the above.

9. A method for manufacturing a polar anisotropic magnet having four faces when viewed in cross-section, A powder material preparation process for preparing powder materials for magnets, A magnetic field molding process for forming a "magnet base material" having a first main surface and a second main surface opposite to the first main surface, comprising: placing the powder material inside a mold corresponding to the shape of the magnet base material; and applying a unidirectional parallel magnetic field from the side of the mold corresponding to the first main surface to the side corresponding to the second main surface to form the magnet base material; When the polar anisotropic magnets are assembled as a magnet assembly, the surface that will become the outer diameter surface of the magnet assembly is defined as the "planned outer diameter surface," and the surface that will become the inner diameter surface is defined as the "planned inner diameter surface." The cutting process involves setting the cut line of the planned outer diameter surface to have an inclination of angle θ1 with respect to the first main surface, cutting the magnet base material along the cut line of the planned outer diameter surface, and setting the cut line of the planned inner diameter surface to have an inclination of angle θ2 with respect to the first main surface, cutting the magnet base material along the cut line of the planned inner diameter surface, thereby cutting out a magnet base material piece having at least the planned outer diameter surface and the planned inner diameter surface as its outer surface. A subassembly step of assembling a magnet base material subassembly having four faces by combining at least four of the magnet base material pieces, wherein, when the face on which magnetic flux should be concentrated is designated as the effective face of the magnet base material subassembly, a horizontal magnet base material piece cut in the cutting step with angles θ1 and θ2 each exceeding 45 degrees and less than 90 degrees is placed on the side of the magnet base material subassembly that will be the effective face, and a vertical magnet base material piece cut in the cutting step with angles θ1 and θ2 each exceeding 0 degrees and less than 45 degrees is placed on the side opposite to the effective face to assemble the magnet base material subassembly. A four-way magnetization step is performed in which a magnetic field in a first direction is applied to the effective surface of the magnetic base material subassembly and a magnetic field in a second direction is applied to the remaining three surfaces of the magnetic base material subassembly, surrounding the magnetic base material subassembly, and the magnetic base material subassembly is magnetized. A method for manufacturing a polar anisotropic magnet, characterized by including the following in this order.

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