Manufacturing device for permanent magnet

Abstract

An apparatus for manufacturing a permanent magnet includes a compression molding mechanism and a magnetic field generating mechanism. The compression molding mechanism includes a pair of punches facing each other and a cylindrical die into which the pair of punches is inserted. The magnetic field generating mechanism includes a pair of coils. The compression molding mechanism is disposed between the pair of coils. A raw material containing a magnet powder is supplied into the die. A magnetic field generated by at least one coil is applied to the feedstock and the feedstock within the die is compressed with a pair of punches. The direction of the magnetic field applied to the raw material is changed by at least one operation selected from the group consisting of movement of the entire magnetic field generation mechanism, rotation of the entire magnetic field generation mechanism, and rotation of the at least one coil.

Description

Technical Field

[0001] The invention relates to a manufacturing device for a permanent magnet. Background Art

[0002] In the manufacture of anisotropic permanent magnets such as bonded magnets and sintered magnets, a raw material containing magnet powder (a plurality of magnet particles formed by a permanent magnet) is supplied into a mold. A magnetic field generated by a coil is applied to the raw material in the mold and the raw material is compressed by the mold, thereby forming a molded body from the raw material. Each magnet particle (magnetic region in each magnet particle) in the molded body is magnetized and oriented along the magnetic field. (Refer to the following patent documents 1 and 2.) For example, in a conventional method for manufacturing a permanent magnet, the mold is configured so that a portion with a high density of magnetic flux (magnetic lines of force) in the magnetic field passes through the raw material in the mold, and a magnetic field parallel to or perpendicular to the pressurization direction (compression direction) of the raw material is applied to the raw material in the mold. As a result, the easy axis of magnetization (crystal axis) of each magnet particle (or each magnetic region) in the permanent magnet is magnetized and oriented parallel to the magnetic field.

[0003] Nd-Fe-B magnets, a type of permanent magnet, are used as raw materials for both bonded magnets and sintered magnets. On the other hand, since the crystal structure of Sm-Fe-N magnets is easily degraded at high temperatures (about 500°C), it is difficult to manufacture sintered magnets from Sm-Fe-N magnets. Therefore, Sm-Fe-N magnets are used as raw materials for bonded magnets that can be manufactured by heating at low temperatures that maintain the crystal structure (thermal curing of thermosetting resins mixed with magnet powders). Compared with Nd-Fe-B magnets, Sm-Fe-N magnets can be manufactured with inexpensive raw materials and have excellent magnetic properties.

[0004] Previous technical literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 10-193189

[0007] Patent Document 2: Japanese Utility Model Application Laid-Open No. 6-79134 Summary of the invention

[0008] Technical issues to be solved by the invention

[0009] Permanent magnets are used in various technical fields as parts constituting motors or actuators. For example, permanent magnets are used in various industrial products such as electric vehicles, hybrid vehicles, smart phones, magnetic resonance imaging devices (MRI), digital cameras, thin TVs, hard disk drives, scanners, air conditioners, heat pumps, refrigerators, vacuum cleaners, washing and drying machines, elevators and wind turbines. According to these various uses, the size, shape and magnetization direction (magnetization direction) required for permanent magnets are different. Therefore, in order to manufacture a variety of permanent magnets, it is expected that the magnetization direction of the permanent magnet can be easily changed according to the use, size and shape of the permanent magnet. In order to easily change the magnetization direction of the permanent magnet, it is expected that the direction and intensity of the magnetic field applied to the raw material in the mold can be easily changed and controlled. In particular, with the miniaturization of permanent magnets, it is necessary to accurately change and control the direction and intensity of the magnetic field in a narrow area (the area where a small mold containing the raw material is set). For example, the magnet powder in the raw material can be oriented along the magnetic field lines with a specified curvature. In other words, each magnetic region in the permanent magnet can be oriented along a curve with a specified curvature. The magnetic powder in the raw material may be oriented along the magnetic force lines while the angle between the pressurization direction of the raw material and the magnetic force lines is maintained at an arbitrary value. In other words, the angle between the pressurization direction of the raw material and the orientation direction of the magnetic powder in the raw material may be adjusted to an arbitrary value. The magnetic field may also be controlled in such a way that a portion of the magnetic flux density is relatively low in the magnetic field is applied to the raw material in the mold.

[0010] However, in conventional permanent magnet manufacturing devices, the movable area of ​​the mold is limited, and the position and direction of the coil are fixed. Therefore, in conventional permanent magnet manufacturing devices, it is difficult to freely change the direction of the magnetic field applied by the coil to the raw material in the mold. In other words, it is difficult to freely change the magnetization direction of the permanent magnet using conventional permanent magnet manufacturing devices.

[0011] An object of one aspect of the present invention is to provide a permanent magnet manufacturing apparatus capable of easily changing the magnetization direction of the permanent magnet.

[0012] Means for solving technical problems

[0013] For example, one aspect of the present invention relates to a permanent magnet manufacturing apparatus as described in any one of the following [1] to [5].

[0014] [1] A permanent magnet manufacturing device, wherein:

[0015] The manufacturing device includes a compression molding mechanism and a magnetic field generating mechanism.

[0016] The compression forming mechanism includes a pair of punches facing each other and a cylindrical die into which the pair of punches are inserted.

[0017] The magnetic field generating mechanism includes a pair of coils.

[0018] The compression molding mechanism is arranged between a pair of coils.

[0019] The compression molding mechanism does not penetrate the inner side of each of the pair of coils.

[0020] The raw material containing magnet powder is supplied into the die,

[0021] A magnetic field is generated by at least one coil of the pair of coils,

[0022] A magnetic field is applied to the raw material in the die, and a pair of punches are used to compress the raw material in the die, thereby forming a compact from the raw material.

[0023] The direction of the magnetic field applied to the material in the die changes by at least one operation selected from the group consisting of overall movement of the magnetic field generating mechanism, overall rotation of the magnetic field generating mechanism, and rotation of at least one coil.

[0024] [2] A permanent magnet manufacturing device, wherein:

[0025] The manufacturing device includes a compression molding mechanism and a magnetic field generating mechanism.

[0026] The compression forming mechanism includes a pair of punches facing each other and a cylindrical die into which the pair of punches are inserted.

[0027] The magnetic field generating mechanism includes a pair of coils.

[0028] At least a portion of the compression molding mechanism is disposed inside each of the pair of coils.

[0029] The raw material containing magnet powder is supplied into the die,

[0030] A magnetic field is generated by at least one coil of the pair of coils,

[0031] A magnetic field is applied to the raw material in the die, and the raw material in the die is compressed by a pair of punches, thereby forming a formed body from the raw material.

[0032] The direction of the magnetic field applied to the material in the die changes by at least one operation selected from the group consisting of overall movement of the magnetic field generating mechanism, overall rotation of the magnetic field generating mechanism, and rotation of at least one coil.

[0033] [3] The permanent magnet manufacturing device according to [1] or [2], wherein:

[0034] The pressing direction is defined as the direction in which a pair of punches face each other.

[0035] The entire magnetic field generating mechanism moves in at least one of a direction parallel to the pressurizing direction and a direction perpendicular to the pressurizing direction.

[0036] [4] The permanent magnet manufacturing device according to any one of [1] to [3], wherein:

[0037] The pressing direction is defined as the direction in which a pair of punches face each other.

[0038] The distance from the rotation axis of the entire magnetic field generating mechanism to one coil is equal to the distance from the rotation axis to the other coil.

[0039] The rotation axis is perpendicular to the pressurization direction.

[0040] The entire magnetic field generating mechanism rotates relative to the rotation axis.

[0041] [5] The permanent magnet manufacturing device according to any one of [1] to [4], wherein:

[0042] The pressing direction is defined as the direction in which a pair of punches face each other.

[0043] At least one coil is rotated so that the angle between the central axis of the coil and the pressing direction changes.

[0044] Effects of the Invention

[0045] According to one aspect of the present invention, there is provided a permanent magnet manufacturing apparatus capable of easily changing a magnetization direction of the permanent magnet. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic cross-sectional view of a manufacturing apparatus according to a first embodiment of the present invention, Figure 1 The cross section shown is parallel to the direction of pressing and passes through the pair of punches, the die and the pair of coils.

[0047] Figure 2 yes Figure 1 Schematic side view of the manufacturing apparatus shown.

[0048] Figure 3 yes Figure 1 The schematic top view of the manufacturing device shown in FIG. 1 shows the parts of the compression molding mechanism other than the die. Figure 3 is omitted.

[0049] Figure 4 Shown in Figure 1The overall movement state of the magnetic field generating mechanism in the manufacturing device shown.

[0050] Figure 5 Shown in Figure 1 The entire magnetic field generating mechanism in the manufacturing device shown is rotated.

[0051] Figure 6 Shown in Figure 1 The manufacturing apparatus shown is in a state where a pair of coils are rotated independently.

[0052] Figure 7 Show Figure 1 An example of a magnetic field applied to a material by a pair of coils included in the manufacturing apparatus shown.

[0053] Figure 8 Show Figure 1 An example of a magnetic field applied to a material by a pair of coils included in the manufacturing apparatus shown.

[0054] Fig. 9 Show Figure 1 An example of a magnetic field applied to a material by a pair of coils included in the manufacturing apparatus shown.

[0055] Fig.10 It is shown Figure 1 An example of a magnetic field applied to a material by one coil included in the manufacturing apparatus shown.

[0056] Fig.11 Show Figure 1 An example of a magnetic field applied to a material by a pair of coils included in the manufacturing apparatus shown.

[0057] Fig.12 is a schematic cross-sectional view of a manufacturing apparatus according to a second embodiment of the present invention, Fig.12 The cross section shown is parallel to the direction of pressing and passes through the pair of punches, the die and the pair of coils.

[0058] Fig.13 yes Fig.12 Schematic side view of the manufacturing apparatus shown.

[0059] Fig.14 yes Fig.12 The schematic top view of the manufacturing device shown in FIG. 1 shows the parts of the compression molding mechanism other than the die. Fig.14 is omitted.

[0060] Fig.15 Show Fig.12 An example of a magnetic field applied to a material by a pair of coils included in the manufacturing apparatus shown.

[0061] Fig.16 Show Fig.12 An example of a magnetic field applied to a material by a pair of coils included in the manufacturing apparatus shown. DETAILED DESCRIPTION

[0062] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals are used for the same components. The present invention is not limited to the following embodiments. Figures 1 to 16 The X, Y, and Z axes shown in FIG. 1 are three coordinate axes that are orthogonal to each other. The directions of the X, Y, and Z axes are respectively Figures 1 to 16 The "permanent magnet" described below refers to at least one anisotropic magnet among a bonded magnet and a sintered magnet.

[0063] (First Embodiment)

[0064] Figures 1 to 11 A permanent magnet manufacturing apparatus 100 according to a first embodiment of the present invention is shown. Figure 1 A cross section of the manufacturing apparatus 100 is shown. Figure 1 The cross section shown is parallel to the front face of the manufacturing apparatus 100 . Figure 2 Show Figure 1 A side view of the manufacturing apparatus 100 is shown. Figure 3 Show Figure 1 The upper surface of the manufacturing apparatus 100 is shown. Figures 4 to 11 The front side of the manufacturing device 100 is shown respectively. Figures 4 to 11 (Each front view) shows a cross section of a raw material rm1 containing magnet powder and a cross section of a cylindrical die d1.

[0065] [Overview of Manufacturing Apparatus 100]

[0066] The permanent magnet manufacturing apparatus 100 includes a compression molding mechanism P10 and a magnetic field generating mechanism M10.

[0067] The compression forming mechanism P10 includes: a pair of punches (a first punch p1 and a second punch p2) facing each other; and a cylindrical die d1 into which the pair of punches are inserted. A first opening (first opening) is formed on the end surface of the die d1 opposite to the first punch p1, and the first punch p1 is inserted into the first opening. A second opening (second opening) is formed on the end surface of the die d1 opposite to the second punch p2, and the second punch p2 is inserted into the second opening. The second punch p2 inserted into the die d1 and the die d1 can form a cavity (concave). The first punch p1 can function as a core (convex).

[0068] The compression forming mechanism P10 further includes a first pressing mechanism p11 and a second pressing mechanism p21. For example, the first pressing mechanism p11 and the second pressing mechanism p21 may be hydraulic devices, respectively. The first punch p1 is connected to the first pressing mechanism p11 and is freely driven by the first pressing mechanism p11. The second punch p2 is connected to the second pressing mechanism p21 and is freely driven by the second pressing mechanism p21. The die d1, the first pressing mechanism p11, and the second pressing mechanism p21 may be fixed in the manufacturing device 100.

[0069] Raw material rm1 containing magnet powder is supplied into die d1. Raw material rm1 in die d1 is sandwiched between first punch p1 and second punch p2 and pressed by first punch p1 and second punch p2. Magnet powder can also be referred to as a plurality of magnet particles formed of permanent magnets.

[0070] The size and shape of each of the first punch p1, the second punch p2, and the die d1 are not limited. For example, the size and shape of each of the first punch p1, the second punch p2, and the die d1 can be changed according to the desired size and shape of the formed body (or permanent magnet). The composition of each of the first punch p1, the second punch p2, and the die d1 is not limited. For example, the first punch p1, the second punch p2, and the die d1 can be metals having sufficient mechanical strength as molds.

[0071] The pressing direction Dp (compression direction) is defined as the direction in which the pair of punches (first punch p1 and second punch p2) face each other. The pressing direction Dp (compression direction) may also be referred to as the direction in which the end faces of the pair of punches face each other or the direction perpendicular to the end faces of the pair of punches.

[0072] The magnetic field generating mechanism M10 includes a pair of coils (first coil c1 and second coil c2). The compression forming mechanism P10 is disposed between the pair of coils (first coil c1 and second coil c2). The compression forming mechanism P10 does not penetrate the inside of each of the pair of coils (first coil c1 and second coil c2).

[0073] The manufacturing device 100 further includes an electric power supply mechanism. The first coil c1 and the second coil c2 are electrically connected to the electric power supply mechanism, respectively. The direction and absolute value of the first current Ic1 generated in the first coil c1 and the direction and absolute value of the second current Ic2 generated in the second coil c2 are freely controlled by the electric power supply mechanism. The electric power supply mechanism is omitted in each figure.

[0074] As long as the first coil c1 and the second coil c2 are conductors, the composition of each of the first coil c1 and the second coil c2 is not limited. The first coil c1 and the second coil c2 can be air core coils. An iron core (soft iron) can also be provided inside each of the first coil c1 and the second coil c2. The inner diameter and the number of turns (number of turns) of each of the first coil c1 and the second coil c2 are not limited. The inner diameters of each of the first coil c1 and the second coil c2 can be the same as each other. The inner diameters of each of the first coil c1 and the second coil c2 can also be different from each other. The number of turns of each of the first coil c1 and the second coil c2 can be the same as each other. The number of turns of each of the first coil c1 and the second coil c2 can also be different from each other.

[0075] In addition to a pair of coils (first coil c1 and second coil c2), the magnetic field generating mechanism M10 also includes a first rotating mechanism Ac1, a second rotating mechanism Ac2, a connecting member M5 and a third rotating mechanism AM10. The first coil c1 is arranged near one end of the connecting member M5 via the first rotating mechanism Ac1. The second coil c2 is arranged near the other end of the connecting member M5 via the second rotating mechanism Ac2. The manufacturing device 100 also includes a moving mechanism. The connecting member M5 is connected to the moving mechanism via the third rotating mechanism AM10. The moving mechanism is omitted in each figure.

[0076] [Overall Movement of Magnetic Field Generating Mechanism M10]

[0077] By connecting the above-mentioned moving mechanism with the connecting part M5, the entire magnetic field generating mechanism M10 can move freely in at least one of the directions parallel to the pressurizing direction Dp and the direction perpendicular to the pressurizing direction Dp. In other words, the position of the magnetic field generating mechanism M10 is adjusted and fixed at the desired position by the moving mechanism. By connecting the above-mentioned moving mechanism with the connecting part M5, the entire magnetic field generating mechanism M10 can move freely in both the direction parallel to the pressurizing direction Dp and the direction perpendicular to the pressurizing direction Dp. However, the range of the overall movement of the magnetic field generating mechanism M10 is limited to the range in which the magnetic field generating mechanism M10 does not physically interfere with the compression molding mechanism P10. The direction parallel to the pressurizing direction Dp can also be referred to as the Z-axis direction. The direction perpendicular to the pressurizing direction Dp can also be referred to as the direction parallel to the XY plane.

[0078] Figure 1 The arrangement of each of the first coil c1 and the second coil c2 before the entire magnetic field generating mechanism M10 moves is shown. Figure 4 An example of the arrangement of each of the first coil c1 and the second coil c2 after the entire magnetic field generating mechanism M10 has moved in two directions, a direction parallel to the pressurizing direction Dp and a direction perpendicular to the pressurizing direction Dp, is shown.

[0079] As long as the moving mechanism has the function of moving the magnetic field generating mechanism M10 as a whole in at least one of the directions parallel to the pressurizing direction Dp and the directions perpendicular to the pressurizing direction Dp, the specific structure of the moving mechanism is not limited. For example, the moving mechanism may include a first actuator (linear actuator) that moves the magnetic field generating mechanism M10 (connecting component M5) in a direction parallel to the pressurizing direction Dp. The moving mechanism may include a second actuator (linear actuator) that moves the magnetic field generating mechanism M10 (connecting component M5) in a direction perpendicular to the pressurizing direction Dp. The moving mechanism may be a multi-axis actuator that moves the magnetic field generating mechanism M10 in two directions, a direction parallel to the pressurizing direction Dp and a direction perpendicular to the pressurizing direction Dp. For example, the multi-axis actuator may include a first actuator and a second actuator. For example, the magnetic field generating mechanism M10 (connecting component M5) may be directly driven by the first actuator, and the magnetic field generating mechanism M10 (connecting component M5) and the first actuator as a whole may be driven by the second actuator. The magnetic field generating mechanism M10 (connecting member M5) may be directly driven by the second actuator, and the magnetic field generating mechanism M10 (connecting member M5) and the second actuator may be driven as a whole by the first actuator. For example, each of the above actuators may be an electric actuator or a hydraulic actuator.

[0080] [Overall Rotation of Magnetic Field Generating Mechanism M10]

[0081] The magnetic field generating mechanism M10 as a whole can freely rotate relative to the third rotation axis LM10 by the third rotating mechanism AM10 connected to the connecting member M5. After the magnetic field generating mechanism M10 rotates, the direction (inclination) of the magnetic field generating mechanism M10 as a whole is fixed. Figure 2 and Figure 3 As shown. For example, the third rotating mechanism AM10 may include a rotating shaft connected to the magnetic field generating mechanism M10 (connecting member M5), a bearing connected to the rotating shaft, and a motor driving the rotating shaft. The overall rotation axis (third rotating axis LM10) of the magnetic field generating mechanism M10 is perpendicular to the pressurizing direction Dp. The overall rotation range of the magnetic field generating mechanism M10 is limited to a range where the magnetic field generating mechanism M10 does not physically interfere with the compression molding mechanism P10.

[0082] The distance from the overall rotation axis (third rotation axis LM10) of the magnetic field generating mechanism M10 to one coil (first coil c1) is equal to the distance from the third rotation axis LM10 to another coil (second coil c2). For example, the distance from the overall rotation axis (third rotation axis LM10) of the magnetic field generating mechanism M10 to the first rotation axis Lc1 of the first coil c1 may be equal to the distance from the third rotation axis LM10 to the second rotation axis Lc2 of the second coil c2. For example, the distance from the overall rotation axis (third rotation axis LM10) of the magnetic field generating mechanism M10 to the center of gravity of the first coil c1 may be equal to the distance from the third rotation axis LM10 to the center of gravity of the second coil c2.

[0083] Figure 1 The arrangement of each of the first coil c1 and the second coil c2 before the entire magnetic field generating mechanism M10 rotates is shown. Figure 5 An example of the arrangement of each of the first coil c1 and the second coil c2 after the entire rotation of the magnetic field generating mechanism M10 is shown.

[0084] [Rotation of coil]

[0085] At least one coil is rotated in such a way that the angle between the central axis of the coil and the pressurization direction Dp changes. That is, by rotating at least one coil, the angle between the central axis of the coil and the pressurization direction Dp is adjusted to a desired value. Only one coil of a pair of coils (the first coil c1 and the second coil c2) can be rotated. A pair of coils (the first coil c1 and the second coil c2) can rotate independently.

[0086] For example, through the first rotating mechanism Ac1, the first coil c1 rotates freely relative to the first rotation axis Lc1. Through the rotation of the first coil c1, the angle θ between the center axis (first center axis Cc1) of the first coil c1 and the pressurization direction Dp changes freely. After the rotation of the first coil c1, the direction (inclination) of the first coil c1 is fixed. The range of rotation of the first coil c1 is limited to the range in which the first coil c1 does not physically interfere with the compression molding mechanism P10. The rotation axis (first rotation axis Lc1) of the first coil c1 is perpendicular to the pressurization direction Dp and is parallel to the overall rotation axis (third rotation axis LM10) of the magnetic field generating mechanism M10. The first rotating mechanism Ac1 may include a rotating shaft connected to the first coil c1, a bearing connecting the rotating shaft, and a motor driving the rotating shaft.

[0087] For example, through the second rotating mechanism Ac2, the second coil c2 rotates freely relative to the second rotation axis Lc2. Through the rotation of the second coil c2, the angle between the center axis of the second coil c2 (the second center axis Cc2) and the pressurization direction Dp changes freely. After the rotation of the second coil c2, the direction (inclination) of the second coil c2 is fixed. The range of rotation of the second coil c2 is limited to the range in which the second coil c2 does not physically interfere with the compression molding mechanism P10. The rotation axis of the second coil c2 (the second rotation axis Lc2) is perpendicular to the pressurization direction Dp and is parallel to the overall rotation axis (the third rotation axis LM10) of the magnetic field generating mechanism M10. The second rotating mechanism Ac2 may include a rotating shaft connected to the second coil c2, a bearing connected to the rotating shaft, and a motor driving the rotating shaft.

[0088] Figure 1 The directions (inclinations) of the first coil c1 and the second coil c2 before they are respectively rotated are shown. Figure 6 An example of the directions (inclinations) of the first coil c1 and the second coil c2 after the first coil c1 and the second coil c2 have each rotated is shown.

[0089] [Method for manufacturing a permanent magnet using the manufacturing apparatus 100]

[0090] The magnetic field H is generated by at least one of the pair of coils (the first coil c1 and the second coil c2). The magnetic field H is applied to the raw material rm1 in the die d1, and the raw material rm1 in the die d1 is compressed by a pair of punches (the first punch p1 and the second punch p2). As a result, a formed body is formed from the raw material rm1, and each magnetic particle (the magnetic region in each magnetic particle) in the formed body is magnetized and oriented along the magnetic field H.

[0091] The magnetic field H may be synthesized by the magnetic field generated in the first coil c1 and the magnetic field generated in the second coil c2, or the synthesized magnetic field H may be applied to the raw material rm1 in the die d1. The magnetic field H generated by only one of the first coil c1 and the second coil c2 may also be applied to the raw material rm1 in the die d1. The magnetic field H may be a static magnetic field (a magnetic field in which the distribution of magnetic flux does not change over time). The magnetic field H may be a pulsed magnetic field.

[0092] The direction of the magnetic field H applied to the raw material rm1 in the die d1 is freely changed by at least one operation selected from the group consisting of the overall movement of the magnetic field generating mechanism M10, the overall rotation of the magnetic field generating mechanism M10, and the rotation of at least one of the first coil c1 and the second coil c2. That is, before the magnetic field H is applied to the raw material rm1 in the die d1, the direction of the magnetic field H applied to the raw material rm1 in the die d1 is freely adjusted by any of the above operations. Therefore, the magnetization direction and orientation direction (orientation direction) of each magnetic particle (magnetic region in each magnetic particle) in the formed body can be freely controlled. The magnetization direction and orientation direction of each magnetic particle (magnetic region in each magnetic particle) in the formed body are also maintained in the completed permanent magnet, so by controlling the magnetization direction and orientation direction of each magnetic particle (magnetic region in each magnetic particle) in the formed body, the magnetization direction of the permanent magnet can be easily changed and adjusted. In other words, according to the manufacturing device 100, the magnetization direction of the permanent magnet can be easily changed and adjusted according to the purpose, size and shape of the permanent magnet.

[0093] Below, reference Figures 7 to 11 , a specific example of the magnetic field H applied to the raw material rm1 in the die d1 is described.

[0094] exist Figure 7 In the manufacturing device 100 shown, the raw material rm1 in the die d1 is arranged between the first coil c1 and the second coil c2. The first coil c1 and the second coil c2 are opposite to each other. The central axes of the first coil c1 and the second coil c2 are consistent with each other, perpendicular to the pressing direction Dp, and pass through the center of the raw material rm1. The direction of the first current Ic1 in the first coil c1 is the same as the direction of the second current Ic2 in the second coil c2. Figure 7 In the manufacturing device 100 shown, the magnetic flux density of the magnetic field H is highest between the first coil c1 and the second coil c2, and the linear magnetic field H formed between the first coil c1 and the second coil c2 is applied to the raw material rm1. The magnetic field H applied to the raw material rm1 is perpendicular to the pressurization direction Dp. Therefore, each magnetic particle in the molded body (the magnetic region in each magnetic particle) is also magnetized and oriented in a direction perpendicular to the pressurization direction Dp.

[0095] exist Figure 8In the manufacturing device 100 shown, the magnetic field generating mechanism M10 is maintained in an overall rotating state. The raw material rm1 in the die d1 is arranged between the first coil c1 and the second coil c2. The first coil c1 and the second coil c2 are opposite to each other. The central axes of the first coil c1 and the second coil c2 are consistent with each other, inclined relative to the pressurizing direction Dp, and pass through the center of the raw material rm1. The direction of the first current Ic1 in the first coil c1 is the same as the direction of the second current Ic2 in the second coil c2. Figure 8 In the manufacturing device 100 shown, the magnetic flux density of the magnetic field H is highest between the first coil c1 and the second coil c2, and the linear magnetic field H formed between the first coil c1 and the second coil c2 is applied to the raw material rm1. The magnetic field H applied to the raw material rm1 is inclined relative to the pressurization direction Dp. Therefore, each magnetic particle in the molded body (the magnetic region in each magnetic particle) is also magnetized and oriented in a direction inclined relative to the pressurization direction Dp.

[0096] exist Fig. 9 In the manufacturing device 100 shown, the entire magnetic field generating mechanism M10 moves in a direction parallel to the pressurizing direction Dp (downward direction), and maintains the state in which the first coil c1 and the second coil c2 are respectively rotated. The first coil c1 and the second coil c2 are arranged below the raw material rm1 in the die d1. The central axis of each of the first coil c1 and the second coil c2 is parallel to the pressurizing direction Dp. That is, the angle between the central axis of each of the first coil c1 and the second coil c2 and the pressurizing direction Dp is zero degree. The direction of the first current Ic1 in the first coil c1 is opposite to the direction of the second current Ic2 in the second coil c2. A curved magnetic flux extends from the upper end of the first coil c1 toward the upper end of the second coil c2. The density of the curved magnetic flux becomes relatively low in the portion where the raw material rm1 is arranged. Since a curved magnetic field H (magnetic flux) is applied to the raw material rm1, each magnetic particle (magnetic region in each magnetic particle) in the formed body is also magnetized and oriented along the same curve as the magnetic field H (magnetic flux).

[0097] exist Fig.10In the manufacturing device 100 shown, the entire magnetic field generating mechanism M10 moves in a direction parallel to the pressurizing direction Dp (downward direction) and in a direction perpendicular to the pressurizing direction Dp (right direction), and the entire magnetic field generating mechanism M10 is maintained in a rotating state. The first coil c1 and the second coil c2 are arranged below the raw material rm1 in the die d1. The first current Ic1 is generated in the first coil c1, but the second current Ic2 is not generated in the second coil c2. Therefore, the magnetic field H is generated only by the first coil c1. A magnetic field H located outside the first coil c1 and having a curved magnetic flux and a relatively low magnetic flux density is applied to the raw material rm1. Since the curved magnetic field H (magnetic flux) is applied to the raw material rm1, each magnetic particle (magnetic domain in each magnetic particle) in the formed body is also magnetized and oriented along the same curve as the magnetic field H (magnetic flux). The magnetic field H applied to the raw material rm1 is inclined relative to the pressurizing direction Dp, so each magnetic particle (magnetic domain in each magnetic particle) in the formed body is also magnetized and oriented in a direction inclined relative to the pressurizing direction Dp.

[0098] exist Fig.11 In the manufacturing device 100 shown, the magnetic field generating mechanism M10 rotates as a whole, and the first coil c1 and the second coil c2 are maintained in a state of rotating respectively. The first coil c1 is arranged on the left side of the die d1, and the second coil c2 is arranged below the die d1. The central axis of the first coil c1 is perpendicular to the pressing direction Dp. That is, the angle between the central axis of the first coil c1 and the pressing direction Dp is 90 degrees. The central axis of the second coil c2 is parallel to the pressing direction Dp. That is, the angle between the central axis of the second coil c2 and the pressing direction Dp is zero degrees. In the magnetic field H generated by the first coil c1 and the second coil c2, a curved magnetic flux extends from the upper end of the second coil c2 toward the right end of the first coil c1. Since a curved magnetic field H (magnetic flux) is applied to the raw material rm1, each magnetic particle (magnetic region in each magnetic particle) in the formed body is also magnetized and oriented along the same curve as the magnetic field H (magnetic flux). The magnetic field H applied to the raw material rm1 is inclined relative to the pressing direction Dp, so each magnet particle in the molded body (the magnetic domain in each magnet particle) is also magnetized and oriented in a direction inclined relative to the pressing direction Dp.

[0099] The direction of the magnetic field H applied to the raw material rm1 in the die d1 is not limited to Figures 7 to 11The directions of the magnetic fields H shown. By changing the respective configurations and directions of the first coil c1 and the second coil c2 by the above operation, the direction and intensity of the magnetic field H applied to the raw material rm1 in the die d1 can be freely changed and adjusted. The direction and intensity of the magnetic field H applied to the raw material rm1 in the die d1 can also be freely changed and adjusted by changing the direction and absolute value of the first current Ic1 in the first coil c1 and the direction and absolute value of the second current Ic2 in the second coil c2. The direction and intensity of the magnetic field H (the direction and density of the magnetic flux) can be easily calculated by simulation using commercially available software.

[0100] The magnet powder contained in the raw material rm1 may be, for example, a Nd-Fe-B magnet (Nd 2 Fe 14 B alloys), samarium-iron-nitrogen magnets (Sm 2 Fe 17 N 3 Alloys), samarium cobalt magnets (Sm 2 Co 17 Alloys), cerium magnets (PrCo 5 For example, Nd-Fe-B magnets are used as raw materials for both bonded magnets and sintered magnets. On the other hand, since the crystal structure of Sm-Fe-N magnets is easily degraded at high temperatures (about 500°C), it is difficult to manufacture sintered magnets from Sm-Fe-N magnets. Therefore, Sm-Fe-N magnets are used as raw materials for bonded magnets that can be manufactured by heating at a low temperature that maintains the crystal structure (thermal curing of a thermosetting resin mixed with magnet powder).

[0101] As a permanent magnet, in the case of manufacturing a bonded magnet, the raw material RM1 may contain components such as a thermosetting resin, a curing agent, a curing accelerator (curing catalyst), a silane coupling agent, a wax (lubricant), a flame retardant, and an organic solvent in addition to the magnet powder. The raw material RM1 for bonded magnets may contain thermoplastic resins in addition to thermosetting resins. As a permanent magnet, in the case of manufacturing a sintered magnet, the raw material RM1 may contain components such as wax (lubricant) in addition to the magnet powder. The raw material RM1 is pre-mixed roughly uniformly.

[0102] In the manufacturing method of a bonded magnet, after a molded body is formed by the above method, a magnetic field (demagnetic field) in the direction opposite to the magnetic field H is applied to the molded body, thereby demagnetizing the molded body. Even in the demagnetized molded body, the easy magnetization axis of each magnet particle in the molded body is maintained in a state of being oriented in the same direction as the magnetic field H. The molded body can be demagnetized using the above manufacturing device 100. That is, the molded body can be demagnetized by applying a magnetic field (demagnetic field) in the direction opposite to the magnetic field H to the molded body clamped by the first punch p1 and the second punch p2 in the die d1. After the molded body is taken out from the die d1, the molded body can be demagnetized using a device different from the above manufacturing device 100. In the manufacturing method of a bonded magnet, a cured product of the molded body can be formed by heating the demagnetized molded body. That is, a cured product of the molded body can be formed by thermal curing of the thermosetting resin in the molded body. In the method for manufacturing a bonded magnet, a magnetic field in the same direction as the magnetic field H is applied to the solidified product of the molded body, so that the solidified product of the molded body is magnetized. By magnetizing the solidified product of the molded body, a permanent magnet (an anisotropic magnet magnetized in a specific direction) is obtained. The size and shape of the permanent magnet can be adjusted by cutting the permanent magnet.

[0103] In the manufacturing method of a sintered magnet, the molded body formed by the above method is sintered to form a sintered body. The sintered body can be used as a permanent magnet (anisotropic magnet magnetized in a specific direction). Before the molded body is sintered, the molded body can be degreased by heating the molded body at a temperature lower than the sintering temperature of the molded body. The sintered body is magnetized by applying a magnetic field in the same direction as the above magnetic field H to the sintered body. The magnetized sintered body can be used as a permanent magnet. The size and shape of the permanent magnet can be adjusted by cutting the permanent magnet.

[0104] (Second Embodiment)

[0105] Figures 12 to 16 A permanent magnet manufacturing apparatus 200 according to a second embodiment of the present invention is shown. Fig.12 A cross section of the manufacturing apparatus 200 is shown. Fig.12 The cross section shown is parallel to the front face of the manufacturing apparatus 200 . Fig.13 Show Fig.12 A side view of manufacturing apparatus 200 is shown. Fig.14 Show Fig.12 The upper surface of the manufacturing apparatus 200 is shown. Fig.15 and Fig.16The front side of the manufacturing device 200 is shown respectively. Fig.15 and Fig.16 (Each front view) shows a cross section of a raw material rm1 containing magnet powder and a cross section of a cylindrical die d1.

[0106] Hereinafter, the differences between the second embodiment and the first embodiment will be mainly described.

[0107] In the permanent magnet manufacturing device 200, at least a portion of the compression molding mechanism P10 is disposed inside each of the pair of coils (the first coil c1 and the second coil c2). In other words, at least a portion of the compression molding mechanism P10 passes through each of the pair of coils. Fig.12 As shown, the first punch p1 penetrates the inside of the first coil c1, and the second punch p2 penetrates the inside of the second coil c2. In the manufacturing apparatus 200, the entire compression molding mechanism P10 can be disposed inside each of the pair of coils (the first coil c1 and the second coil c2).

[0108] The range of the overall movement of the magnetic field generating mechanism M10 is limited to a range in which the compression molding mechanism P10 disposed inside each of the pair of coils does not physically interfere with the magnetic field generating mechanism M10 .

[0109] The range of the overall rotation of the magnetic field generating mechanism M10 is limited to a range in which the compression molding mechanism P10 disposed inside each of the pair of coils does not physically interfere with the magnetic field generating mechanism M10 .

[0110] The range in which the first coil c1 rotates is limited to a range in which the compression-molding mechanism P10 disposed inside the first coil c1 does not physically interfere with the first coil c1.

[0111] The range in which the second coil c2 rotates is limited to a range in which the compression-molding mechanism P10 disposed inside the second coil c2 does not physically interfere with the second coil c2.

[0112] The manufacturing apparatus 200 according to the second embodiment is the same as the manufacturing apparatus 100 according to the first embodiment except for the above matters. The manufacturing method of the permanent magnet using the manufacturing apparatus 200 is the same as the manufacturing method of the permanent magnet using the manufacturing apparatus 100 except for the above matters.

[0113] In the manufacturing device 200, the direction of the magnetic field H applied to the raw material rm1 in the die d1 is freely changed by at least one operation selected from the group consisting of the overall movement of the magnetic field generating mechanism M10, the overall rotation of the magnetic field generating mechanism M10, and the rotation of at least one of the first coil c1 and the second coil c2. That is, before the magnetic field H is applied to the raw material rm1 in the die d1, the direction of the magnetic field H applied to the raw material rm1 in the die d1 is freely adjusted by any of the above operations. Therefore, the magnetization direction and orientation direction of each magnetic particle (magnetic region in each magnetic particle) in the formed body can be freely controlled. The magnetization direction and orientation direction of each magnetic particle (magnetic region in each magnetic particle) in the formed body are also maintained in the completed permanent magnet, so by controlling the magnetization direction and orientation direction of each magnetic particle (magnetic region in each magnetic particle) in the formed body, the magnetization direction of the permanent magnet can be easily changed and adjusted. In other words, according to the manufacturing apparatus 200 , the magnetization direction of the permanent magnet can be easily changed and adjusted according to the purpose, size, and shape of the permanent magnet.

[0114] For example, in Fig.15 In the manufacturing device 200 shown, the raw material rm1 in the die d1 is arranged between the first coil c1 and the second coil c2. The first coil c1 and the second coil c2 are opposite to each other. The central axes of the first coil c1 and the second coil c2 are consistent with each other, parallel to the pressurization direction Dp, and pass through the center of the raw material rm1. The direction of the first current Ic1 in the first coil c1 is the same as the direction of the second current Ic2 in the second coil c2. Fig.15 In the manufacturing device 100 shown, the magnetic flux density of the magnetic field H is highest between the first coil c1 and the second coil c2, and the linear magnetic field H formed between the first coil c1 and the second coil c2 is applied to the raw material rm1. The magnetic field H applied to the raw material rm1 is parallel to the pressurization direction Dp. Therefore, each magnetic particle in the molded body (the magnetic region in each magnetic particle) is also magnetized and oriented in a direction parallel to the pressurization direction Dp.

[0115] exist Fig.16 In the manufacturing device 200 shown, the magnetic field generating mechanism M10 is maintained in an overall rotating state. The raw material rm1 in the die d1 is arranged between the first coil c1 and the second coil c2. The first coil c1 and the second coil c2 are opposite to each other. The central axes of the first coil c1 and the second coil c2 are consistent with each other, inclined relative to the pressurizing direction Dp, and pass through the center of the raw material rm1. The direction of the first current Ic1 in the first coil c1 is the same as the direction of the second current Ic2 in the second coil c2. Fig.16In the manufacturing device 200 shown, the magnetic flux density of the magnetic field H is highest between the first coil c1 and the second coil c2, and the linear magnetic field H formed between the first coil c1 and the second coil c2 is applied to the raw material rm1. The magnetic field H applied to the raw material rm1 is inclined relative to the pressurization direction Dp. Therefore, each magnetic particle in the molded body (the magnetic region in each magnetic particle) is also magnetized and oriented in a direction inclined relative to the pressurization direction Dp.

[0116] The direction of the magnetic field H applied to the raw material rm1 in the die d1 is not limited to Fig.15 and Fig.16 The directions of the magnetic fields H are shown.

[0117] The present invention is not necessarily limited to the above-described embodiment. Various modifications of the present invention can be made without departing from the gist of the present invention, and these modifications are also included in the present invention.

[0118] For example, the manufacturing apparatus 100 and the manufacturing apparatus 200 may further include a heating mechanism (heater) for heating the raw material rm1 or the formed body in the die d1.

[0119] Industrial Applicability

[0120] For example, a permanent magnet manufacturing apparatus according to one aspect of the present invention is used to manufacture a bonded magnet or a sintered magnet.

[0121] Explanation of symbols

[0122] 100, 200-permanent magnet manufacturing device, P10-compression molding mechanism, M10-magnetic field generating mechanism, LM10-the overall rotation axis of the magnetic field generating mechanism M10, AM10-the third rotation mechanism (the rotation mechanism of the magnetic field generating mechanism M10), p1-the first punch, p11-the first pressurizing mechanism (the pressurizing mechanism of the first punch p1), p2-the second punch, p21-the second pressurizing mechanism (the pressurizing mechanism of the second punch p2), Dp-pressurizing direction, d1-die, c1-the first coil, Cc1-the central axis of the first coil c1, Lc1-the rotation axis of the first coil c1, Ac1-the A rotating mechanism (rotating mechanism of the first coil c1), Ic1-the first current in the first coil c1 and its direction, c2-the second coil, Cc2-the central axis of the second coil c2, Lc2-the rotation axis of the second coil c2, Ac2-the second rotating mechanism (rotating mechanism of the second coil c2), Ic2-the second current in the second coil c2 and its direction, M5-connecting part, rm1-raw material containing magnet powder, H-the magnetic field applied to the raw material rm1 and its direction, θ-the angle between the central axis of the coil and the pressurizing direction Dp (the angle between the central axis Cc1 of the first coil c1 and the pressurizing direction Dp).

Claims

1. A permanent magnet manufacturing device, wherein: The manufacturing device comprises a compression molding mechanism and a magnetic field generating mechanism. The compression forming mechanism includes a pair of punches facing each other and a cylindrical die into which the pair of punches are inserted. The magnetic field generating mechanism comprises a pair of coils, The compression molding mechanism is arranged between the pair of coils, The compression molding mechanism does not penetrate the inner side of each of the pair of coils. A raw material containing magnet powder is supplied into the die, generating a magnetic field by at least one of the pair of coils, applying the magnetic field to the raw material in the die and compressing the raw material in the die with the pair of punches, thereby forming a formed body from the raw material, The direction of the magnetic field applied to the material in the die changes by at least one operation selected from the group consisting of overall movement of the magnetic field generating mechanism, overall rotation of the magnetic field generating mechanism, and rotation of at least one of the coils.

2. A permanent magnet manufacturing device, wherein: The manufacturing device comprises a compression molding mechanism and a magnetic field generating mechanism. The compression forming mechanism includes a pair of punches facing each other and a cylindrical die into which the pair of punches are inserted. The magnetic field generating mechanism comprises a pair of coils, At least a portion of the compression molding mechanism is disposed inside each of the pair of coils. A raw material containing magnet powder is supplied into the die, generating a magnetic field by at least one of the pair of coils, applying the magnetic field to the raw material in the die and compressing the raw material in the die with the pair of punches, thereby forming a formed body from the raw material, The direction of the magnetic field applied to the material in the die changes by at least one operation selected from the group consisting of overall movement of the magnetic field generating mechanism, overall rotation of the magnetic field generating mechanism, and rotation of at least one of the coils.

3. The permanent magnet manufacturing device according to claim 1 or 2, wherein: The pressing direction is defined as the direction in which the pair of punches face each other. The entire magnetic field generating mechanism moves in at least one of a direction parallel to the pressurizing direction and a direction perpendicular to the pressurizing direction.

4. The permanent magnet manufacturing device according to claim 1 or 2, wherein: The pressing direction is defined as the direction in which the pair of punches face each other. The distance from the rotation axis of the entire magnetic field generating mechanism to one of the coils is equal to the distance from the rotation axis to another of the coils. The rotation axis is perpendicular to the pressurizing direction, The entirety of the magnetic field generating mechanism rotates relative to the rotation axis.

5. The permanent magnet manufacturing device according to claim 1 or 2, wherein: The pressing direction is defined as the direction in which the pair of punches face each other. At least one of the coils rotates in such a manner that an angle between a central axis of the coil and the pressurizing direction changes.

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