Manufacturing equipment for magnetic molded bodies
The apparatus addresses the challenge of achieving high residual magnetic flux density by integrating a yoke within the mold, enhancing magnetic field orientation and density in magnetic molded bodies, facilitating easier and more efficient production.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- RESONAC CORP
- Filing Date
- 2024-12-20
- Publication Date
- 2026-07-02
Smart Images
Figure 2026109880000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to an apparatus for manufacturing a magnetic molded body.
Background Art
[0002] Permanent magnets such as bonded magnets and sintered magnets are formed using magnetic molded bodies. Examples of manufacturing methods for magnetic molded bodies are disclosed in Patent Documents 1 and 2. In the manufacture of a magnetic molded body, first, a material containing magnet powder (a large number of magnet particles) is supplied into a space in a mold. The mold has an opening leading to the space in the mold, and the material is supplied into the space in the mold through the opening. Subsequently, a punch for compressing the material is inserted into the space in the mold through the opening. While applying a magnetic field generated by a coil to the material in the mold, the material is compressed by the punch, thereby forming a magnetic molded body from the material. Each magnet particle (magnetic domain in each magnet particle) in the magnetic molded body is magnetized and oriented along the magnetic field.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] Permanent magnets are used in various technical fields as components constituting, for example, motors or actuators. Depending on the use of the permanent magnet, a high residual magnetic flux density (Br) may be required for the magnetic molded body. Therefore, a technique capable of easily manufacturing a magnetic molded body having a high residual magnetic flux density is desired.
[0005] The object of this disclosure is to provide a magnetic molding apparatus that can easily produce magnetic moldings having a high residual magnetic flux density. [Means for solving the problem]
[0006] One aspect of the present disclosure is [1] "a manufacturing apparatus for a magnetic molded body, comprising: a mold including a space into which a material for a magnetic molded body containing magnetic powder is supplied; a compression mechanism for compressing the material supplied into the space; a magnetic field generating mechanism having a pair of coils arranged to sandwich the space; and a functional component having a predetermined function disposed within the mold, wherein the functional component further functions as a yoke that guides the magnetic field generated by the magnetic field generating mechanism toward the material supplied into the space."
[0007] In the above-described magnetic molded body manufacturing apparatus, a functional component that acts as a yoke is placed inside the mold to guide the magnetic field generated by the magnetic field generation mechanism toward the magnetic molded body material supplied to the mold space. In this case, compared to when the yoke is placed outside the mold, the functional component that functions as a yoke is placed closer to the magnetic molded body material, so the magnetic field applied to the material can be made larger. This increases the orientation of the manufactured magnetic molded body and increases the residual magnetic flux density. Furthermore, in the above-described magnetic molded body manufacturing apparatus, a functional component having a predetermined function also functions as a yoke. That is, for example, a functional component such as a heater or thermocouple placed inside the mold also functions as a yoke, so there is no need to provide a yoke as a separate component (without making the manufacturing apparatus complex), and magnetic molded bodies can be easily manufactured. Therefore, according to the above-described magnetic molded body manufacturing apparatus, magnetic molded bodies with a high residual magnetic flux density can be easily manufactured.
[0008] The above-described magnetic molded body manufacturing apparatus may also be [2] "the magnetic molded body manufacturing apparatus described in [1] above, wherein the functional component is arranged between one of the pair of coils and the space, and the longitudinal direction of the functional component is aligned with the direction from the one coil toward the space." In this case, the magnetic field generated by the magnetic field generation mechanism can be efficiently applied to the magnetic molded body material supplied to the space of the mold, and a magnetic molded body with a higher residual magnetic flux density can be manufactured.
[0009] The above-described apparatus for manufacturing a magnetic molded body may also be [3] "the apparatus for manufacturing a magnetic molded body according to [1] or [2] above, wherein the functional component is arranged between one of the pair of coils and the space, and has a shape that becomes smaller from the one coil toward the space." In this case, the magnetic field generated by the magnetic field generation mechanism can be efficiently applied to the material of the magnetic molded body supplied to the space of the mold, and a magnetic molded body with a higher residual magnetic flux density can be manufactured.
[0010] The above-described apparatus for manufacturing a magnetic molded body may also be [4] "the apparatus for manufacturing a magnetic molded body according to any one of [1] to [3] above, wherein the functional component is a heater having the function of heating the material supplied to the space as the predetermined function." In this case, there is no need to provide a yoke as a separate component from the heater, and the magnetic molded body can be easily manufactured.
[0011] The above-described apparatus for manufacturing a magnetic molded body may also be [5] "the apparatus for manufacturing a magnetic molded body according to any one of [1] to [3] above, wherein the functional component is a thermocouple having the function of measuring the temperature of the material supplied to the space as a predetermined function." In this case, there is no need to provide a yoke as a separate component from the thermocouple, and the magnetic molded body can be easily manufactured.
[0012] The above-described apparatus for manufacturing a magnetic molded body may also be [6] "the apparatus for manufacturing a magnetic molded body according to any one of [1] to [5] above, wherein the mold has a surface facing one of the pair of coils, the mold has a recess formed on the surface that opens, and the functional component is arranged in the recess." In this case, since the recess in which the functional component is arranged opens on the surface of the mold facing one of the coils, the functional component can be placed close to one of the coils. This makes it possible to efficiently collect the magnetic field generated by the magnetic field generation mechanism with the functional component, and to manufacture a magnetic molded body with a higher residual magnetic flux density.
[0013] The above-described magnetic molded body manufacturing apparatus may also be [7] "the magnetic molded body manufacturing apparatus described in [6] above, wherein the distance from the bottom surface of the recess to the space is smaller than the depth of the recess." In this case, functional components can be placed closer to the magnetic molded body material supplied to the mold space. This makes it possible to efficiently apply the magnetic field generated by the magnetic field generation mechanism to the magnetic molded body material supplied to the mold space, and to manufacture a magnetic molded body with a higher residual magnetic flux density.
[0014] The above-described magnetic molded body manufacturing apparatus may also be [8] "a magnetic molded body manufacturing apparatus according to any one of [1] to [7] above, comprising a pair of functional components, each of which is the functional component, wherein one of the pair of functional components is disposed between one of the pair of coils and the space, and the other of the pair of functional components is disposed between the other of the pair of coils and the space." In this case, the magnetic field generated by the magnetic field generation mechanism can be efficiently applied to the magnetic molded body material supplied to the mold space, and a magnetic molded body with a higher residual magnetic flux density can be manufactured. [Effects of the Invention]
[0015] According to one aspect of this disclosure, a magnetic molded body having a high residual magnetic flux density can be easily manufactured. [Brief explanation of the drawing]
[0016] [Figure 1] Figure 1 is a schematic diagram showing a manufacturing apparatus for a magnetic molded body according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing a manufacturing apparatus for a magnetic molded body according to the second embodiment. [Modes for carrying out the invention]
[0017] The following describes exemplary embodiments with reference to the drawings. In each drawing, the same or equivalent elements are denoted by the same reference numerals, and redundant explanations are omitted.
[0018] [First Embodiment] [Manufacturing equipment for magnetic molded products] Referring to Figure 1, the configuration of the magnetic molded body manufacturing apparatus 1 according to the first embodiment will be described. Figure 1 is a schematic diagram of the manufacturing apparatus 1. The manufacturing apparatus 1 is an apparatus for manufacturing a magnetic molded body from a material (raw material) containing magnetic powder. A magnetic molded body is an object that has magnetic properties, which is formed from a magnetic material into a specific shape. Magnetic molded bodies may be used, for example, in the manufacture of permanent magnets such as bonded magnets and sintered magnets. Permanent magnets are used in a variety of industrial products, such as electric vehicles, hybrid vehicles, smartphones, magnetic resonance imaging (MRI) devices, digital cameras, flat-screen TVs, hard disk drives, scanners, air conditioners, heat pumps, refrigerators, vacuum cleaners, washer-dryers, elevators, and wind turbines.
[0019] As shown in FIGS. 1 and 2, the manufacturing apparatus 1 includes a mold 2, a compression mechanism 3, a magnetic field generation mechanism 4, and a pair of functional components 5 and 6. The compression mechanism 3 has a first punch 31 and a second punch 32 that compress the material of the magnetic molded body supplied to the mold 2, and the first punch 31 and the second punch 32 face each other. Hereinafter, the direction in which the first punch 31 and the second punch 32 face each other is defined as the Z-axis direction, one direction intersecting the Z-axis direction is defined as the X-axis direction, and the direction intersecting the Z-axis direction and the X-axis direction is defined as the Y-axis direction. In this example, the X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other.
[0020] The mold 2 is supplied with a material M of a magnetic molded body containing magnetic powder. The magnetic powder contained in the material M may be, for example, an Nd-Fe-B-based magnet (an alloy such as Nd2Fe 14 B, etc.), a samarium-iron-nitrogen-based magnet (Sm2Fe 17 N3, etc.), a samarium cobalt-based magnet (Sm2Co 17 etc.), a praseodymium-based magnet (an alloy such as PrCo5), or a ferrite magnet. For example, Nd-Fe-B-based magnets are used for materials of magnetic molded bodies that become bonded magnets and sintered magnets. On the other hand, since the crystal structure of Sm-Fe-N-based magnets is likely to deteriorate at high temperatures (about 500°C), it is difficult to manufacture sintered magnets from Sm-Fe-N-based magnets. Therefore, Sm-Fe-N-based magnets are used for materials of magnetic molded bodies that become bonded magnets that can be manufactured by heating at a low temperature at which the crystal structure is maintained (thermosetting of the thermosetting resin mixed with the magnetic powder).
[0021] When a bonded magnet is manufactured using a magnetic molded body, the material M may contain components such as a thermosetting resin, a curing agent, a curing accelerator (curing catalyst), a silane coupling agent, wax (lubricant), a flame retardant, and an organic solvent in addition to the magnet powder. The material M for the bonded magnet may further contain a thermoplastic resin in addition to the thermosetting resin. When a sintered magnet is manufactured using a magnetic molded body, the material M may contain components such as wax (lubricant) in addition to the magnet powder. The material M may be preliminarily mixed substantially uniformly. The material M may be in the form of powder, tablet, or paste.
[0022] The mold 2 has a cylindrical shape extending along the Z-axis direction (having an axis along the Z-axis direction). The mold 2 is formed of, for example, metal. The mold 2 includes a space S into which the material M is supplied. The space S is formed inside the mold 2. The mold 2 has a surface 21 and a surface 22 located on the opposite side of the surface 21 in the Z-axis direction. Each of the surfaces 21 and 22 extends perpendicular to the Z-axis direction. An opening into which the end of the first punch 31 is inserted is formed in the surface 21. An opening into which the end of the second punch 32 is inserted is formed in the surface 22. The openings formed in each of the surfaces 21 and 22 are connected to the space S.
[0023] The mold 2 has a surface 23 and a surface 24 located on the opposite side of surface 23 in the X-axis direction. Each of surfaces 23 and 24 extends perpendicular to the X-axis direction. Surface 23 faces the first coil 41, which will be described later, in the X-axis direction. A recess 25 is formed on surface 23, which opens on surface 23. The recess 25 is recessed from surface 23 toward space S (surface 24). The recess 25 extends along the X-axis direction. The recess 25 does not reach space S. That is, the recess 25 has a bottom surface 25a, and a part of the mold (a wall that defines space S) exists between the bottom surface 25a and space S. The distance D1 (shortest distance) from the bottom surface 25a of the recess 25 to space S is smaller than the depth D2 (maximum depth) of the recess 25. The depth D2 is the distance in the X-axis direction from the opening of the recess 25 on surface 23 to the bottom surface 25a. The distance D1 may be 50% or less of the depth D2, 25% or less, or 10% or less.
[0024] Surface 24 faces the second coil 42, which will be described later, in the X-axis direction. A recess 26 is formed on surface 24, which opens on surface 24. The recess 26 is recessed from surface 24 toward space S (surface 23). The recess 26 extends along the X-axis direction. The recess 26 does not reach space S. That is, the recess 26 has a bottom surface 26a, and a part of the mold (a wall that defines space S) exists between the bottom surface 26a and space S. The distance D3 (shortest distance) from the bottom surface 26a of the recess 26 to space S is smaller than the depth D4 (maximum depth) of the recess 26. Depth D4 is the distance in the X-axis direction from the opening of the recess 26 on surface 24 to the bottom surface 26a. The distance D3 may be 50% or less of the depth D4, 25% or less, or 10% or less.
[0025] The compression mechanism 3 is a device for compressing the material M supplied to the space S of the mold 2. The compression mechanism 3 includes a first punch 31, a second punch 32, a first pressurizing mechanism 33, and a second pressurizing mechanism 34. The first punch 31 has a columnar shape (for example, a rectangular prism shape) extending along the Z-axis direction. The first punch 31 is made of, for example, metal. The first punch 31 has an end face 31a. In the Z-axis direction, the end face 31a faces the end face 32a of the second punch 32, which will be described later. The tip of the first punch 31 (the end where the end face 31a is located) is inserted into the space S through an opening formed in the surface 21 of the mold 2. The end of the first punch 31 opposite to the end face 31a is connected to the first pressurizing mechanism 33.
[0026] The second punch 32 has a columnar shape (for example, a rectangular prism shape) that extends along the Z-axis direction. The second punch 32 is made of, for example, metal. The second punch 32 has an end face 32a that faces the end face 31a in the Z-axis direction. The tip of the second punch 32 (the end where the end face 32a is located) is inserted into the space S through an opening formed in the surface 22 of the mold 2. The end of the second punch 32 opposite to the end face 32a is connected to the second pressurizing mechanism 34.
[0027] The first pressurizing mechanism 33 is a device that moves the first punch 31 along the Z-axis direction. The first pressurizing mechanism 33 may be, for example, a hydraulic device. The first pressurizing mechanism 33 is fixed in the manufacturing apparatus 1. The second pressurizing mechanism 34 is a device that moves the second punch 32 along the Z-axis direction. The second pressurizing mechanism 34 may be, for example, a hydraulic device. The second pressurizing mechanism 34 is fixed in the manufacturing apparatus 1. The first pressurizing mechanism 33 and the second pressurizing mechanism 34 move the first punch 31 and the second punch 32 closer to each other in the Z-axis direction. As a result, the first punch 31 and the second punch 32 compress the material M placed between the end faces 31a and 32a. At this time, the material M may be compressed by moving only the first punch 31 while the second punch 32 is fixed.
[0028] The magnetic field generating mechanism 4 is a device that applies a magnetic field H to a material M supplied into space S. The magnetic field generating mechanism 4 has a pair of first coils 41 and second coils 42. The first coil 41 and the second coil 42 are arranged to sandwich the mold 2 in the X-axis direction. Arrangement of the first coil 41 and the second coil 42 to sandwich the mold 2 means that the mold 2 is located between the first coil 41 and the second coil 42, and it is not necessary for the first coil 41 and the second coil 42 to be in contact with the mold 2. In this example, the first coil 41 and the second coil 42 are spaced apart from the mold 2. The first coil 41, the mold 2, and the second coil 42 are arranged in this order in the X-axis direction.
[0029] The first coil 41 is an air-core coil having a helical shape. The first coil 41 is formed of a conductor. The first coil 41 may be formed, for example, by winding a wire in a helical shape. In this example, the coil axis direction of the first coil 41 is along the X-axis direction in which the first coil 41 and the second coil 42 are aligned. The coil axis of the first coil 41 passes through the central part of the space S (material M) in the Z-axis direction.
[0030] The second coil 42 is an air-core coil having a helical shape. The second coil 42 is formed of a conductor. The second coil 42 may be formed, for example, by winding a wire in a helical shape. In this example, the coil axis direction of the second coil 42 is along the X-axis direction in which the first coil 41 and the second coil 42 are aligned. The coil axis of the second coil 42 passes through the central part of space S (material M) in the Z-axis direction. The inner diameter and number of turns of the first coil 41 and the second coil 42 are not limited. The inner diameters of the first coil 41 and the second coil 42 may be the same or different from each other. The number of turns of the first coil 41 and the second coil 42 may be the same or different from each other.
[0031] The manufacturing apparatus 1 further includes a power supply device (not shown) electrically connected to the first coil 41 and the second coil 42. The power supply device supplies power to the first coil 41 and the second coil 42. The power supply device controls the direction and magnitude of the current flowing through the first coil 41 and the current flowing through the second coil 42. When current flows through the first coil 41 and the second coil 42, a magnetic field is generated in each of the first coil 41 and the second coil 42. The magnetic field generated in the first coil 41 and the magnetic field generated in the second coil 42 combine to form a magnetic field H. The combined magnetic field H is applied to the material M in the mold 2.
[0032] Functional component 5 is a component having a predetermined function. The predetermined function is a function that can be used in the process of manufacturing a permanent magnet from material M. In this example, functional component 5 is a heater whose predetermined function is to heat the material M supplied to space S. The manufacturing apparatus 1 further includes a heating control device (not shown) that is electrically connected to functional component 5 and controls the temperature of functional component 5, which functions as a heater (heating part). The heat generated in functional component 5 is transferred to material M via the mold 2.
[0033] Functional component 5 further functions as a yoke, guiding the magnetic field H generated by the magnetic field generation mechanism 4 toward the material M supplied to space S. That is, functional component 5 according to this embodiment has at least two functions, including the function of a heater and the function of a yoke. A yoke is a member for guiding a magnetic field in a specific direction. Functional component 5 is formed by including a high-permeability material such as Permendur, Permalloy, or Sendust. The relative permeability of the high-permeability material included in functional component 5 may be 10 or more, preferably 100 or more, more preferably 1000 or more, and even more preferably 5000 or more. Relative permeability is the value obtained by dividing the permeability of the high-permeability material by the permeability of vacuum. Functional component 5, which functions as a yoke, has the function of collecting the magnetic field lines (magnetic flux) of the magnetic field H generated by the first coil 41 and the second coil 42. That is, the magnetic field lines of the magnetic field H preferentially pass through the region where functional component 5 is located. As a result, the density of magnetic field lines in the region where the functional component 5 is located becomes higher compared to other parts. In other words, the magnetic field strength in the region where the functional component 5 is located becomes relatively larger within the magnetic field H.
[0034] The functional component 5 is located within the mold 2. More specifically, the functional component 5 is located within the recess 25. In this example, the entire functional component 5 is housed within the recess 25. The functional component 5 is located between the first coil 41 and space S. When viewed from the direction in which the first coil 41 and the mold 2 are aligned (X-axis direction), the functional component 5 overlaps with the first coil 41 and space S. The functional component 5 extends along the X-axis direction. The width (maximum width) of the functional component 5 in the X-axis direction is greater than the width (maximum width) of the functional component 5 in the Y-axis direction and the width (maximum width) in the Z-axis direction. The longitudinal direction of the functional component 5 is along the X-axis direction. The longitudinal direction of the functional component 5 is along the direction from the first coil 41 toward space S. One end of the functional component 5 in the longitudinal direction is in contact with the bottom surface 25a of the recess 25. The other end of the functional component 5 in the longitudinal direction is exposed to the outside of the mold 2 through the opening of the recess 25 on the surface 23.
[0035] Functional component 6 is a component having a predetermined function. In this example, functional component 6 is a heater whose predetermined function is to heat the material M supplied to space S. The manufacturing apparatus 1 further includes a heating control device (not shown) that is electrically connected to functional component 6 and controls the temperature of functional component 6, which functions as a heater (heat-generating part). The heat generated in functional component 6 is transferred to material M via mold 2.
[0036] The functional component 6 further functions as a yoke, guiding the magnetic field H generated by the magnetic field generation mechanism 4 toward the material M supplied to space S. That is, the functional component 6 according to this embodiment has at least two functions, including the function of a heater and the function of a yoke. The functional component 6 is formed by including a high-permeability material such as Permendur, Permalloy, or Sendust. The relative permeability of the high-permeability material included in the functional component 6 may be 10 or more, preferably 100 or more, more preferably 1000 or more, and even more preferably 5000 or more. The relative permeability is the value obtained by dividing the permeability of the high-permeability material by the permeability of vacuum. The functional component 6, which functions as a yoke, has the function of collecting the magnetic field lines (magnetic flux) of the magnetic field H generated by the magnetic field generation mechanism 4 (first coil 41 and second coil 42). That is, the magnetic field lines of the magnetic field H preferentially pass through the region where the functional component 6 is located. As a result, the density of magnetic field lines in the region where the functional component 6 is located is higher than in other parts. In other words, the magnetic field strength in the region where the functional component 6 is located becomes relatively larger within the magnetic field H.
[0037] The functional component 6 is located within the mold 2. More specifically, the functional component 6 is located within the recess 26. In this example, the entire functional component 6 is housed within the recess 26. The functional component 6 is located between the second coil 42 and space S. When viewed from the direction in which the second coil 42 and the mold 2 are aligned (X-axis direction), the functional component 6 overlaps with the second coil 42 and space S. The functional component 6 extends along the X-axis direction. The width (maximum width) of the functional component 6 in the X-axis direction is greater than the width (maximum width) of the functional component 6 in the Y-axis direction and the width (maximum width) in the Z-axis direction. The longitudinal direction of the functional component 6 is along the X-axis direction. The longitudinal direction of the functional component 6 is along the direction from the second coil 42 toward space S. One end of the functional component 6 in the longitudinal direction is in contact with the bottom surface 26a of the recess 26. The other end of the functional component 6 in the longitudinal direction is exposed to the outside of the mold 2 through the opening of the recess 26 on the surface 24.
[0038] In the example shown in Figure 1, the central portions of functional component 5 and functional component 6 in the Z-axis direction coincide with the central portion of space S (material M). That is, the positions of functional component 5 and functional component 6 in the Z-axis direction coincide with each other. As a result, the magnetic field lines of the magnetic field H that are collected by functional component 5 pass through space S (material M) and then reach functional component 6. In this example, the magnetic field lines passing through space S (material M) are aligned with the X-axis direction. The density of magnetic field lines passing through space S (material M) is higher than the density of magnetic field lines passing outside space S (material M) (e.g., the first punch 31 and the second punch 32) when viewed from the X-axis direction. That is, the magnetic field strength in space S (material M) is greater than the magnetic field strength outside space S (material M). The magnetic field lines that have passed through functional component 6 spread out toward the second coil 42.
[0039] [Method for manufacturing magnetic molded bodies and permanent magnets] Next, a method for manufacturing a magnetic molded body and a permanent magnet will be described. First, the material M for the magnetic molded body is supplied to the mold 2. At this time, the tip of the second punch 32 (the end where the end face 32a is located) is inserted into the space S through an opening formed on the surface 22 of the mold 2. This creates a recess between the inner surface of the mold 2 and the end face 32a. The material M is supplied into this recess. The supply mechanism for supplying the material M to the mold 2 may be provided as part of the manufacturing apparatus 1, or it may be provided as a separate component from the manufacturing apparatus 1. The configuration of the supply mechanism is not limited. After the material M has been supplied, the tip of the first punch 31 is inserted into the space S through an opening on the surface 21 of the mold 2. This houses the material M within the space defined by the inner surface and surfaces 21 and 22 of the mold 2.
[0040] Next, the material M is compressed while a magnetic field is applied to it and it is heated. In this example, the magnetic field generation mechanism 4 (first coil 41 and second coil 42) applies a magnetic field H to the material M. The power supply device supplies current to the first coil 41 and the second coil 42, generating a magnetic field in each of the first coil 41 and the second coil 42. The magnetic field H generated in the first coil 41 and the magnetic field generated in the second coil 42 are combined. The combined magnetic field H is applied to the material M in the mold 2. The magnetization direction of the entire magnetic molded body is approximately or perfectly parallel to the direction of the magnetic field H applied to the material M.
[0041] In this configuration, the functional components 5 and 6, which function as yokes, have the function of collecting the magnetic field lines (magnetic flux) of the magnetic field H generated by the magnetic field generation mechanism 4 (first coil 41 and second coil 42). The magnetic field lines of the magnetic field H preferentially pass through the region where the functional components 5 and 6 are located. As a result, the density of magnetic field lines in the region where the functional components 5 and 6 are located is higher than in other parts. That is, the magnetic field strength in the region where the functional components 5 and 6 are located is relatively larger than in other parts of the magnetic field H. Because the functional components 5 and 6, which function as yokes, are located inside the mold 2 (located near the material M), a larger magnetic field is applied to the material compared to a configuration in which the functional components 5 and 6 do not function as yokes and a configuration in which the yokes are located outside the mold.
[0042] Each magnetic particle in material M is magnetized and rotated by a magnetic field H, and the easy magnetization axis of the magnetic domain in each magnetic particle is oriented along the magnetic field H. In other words, each magnetic particle in material M is oriented so that its magnetization direction is approximately parallel to the magnetic field H. If each magnetic particle is a single crystal grain (single magnetic domain), the magnetization direction of each magnetic particle is the same as the direction in which the easy magnetization axis of each magnetic particle extends.
[0043] The application of the magnetic field H may be terminated at the same time as the molding pressure reaches its maximum value. The application of the magnetic field H may be terminated when the molding pressure begins to decrease. The application of the magnetic field H may be terminated at the same time as the compression of the material M in the mold 2 ends. The magnetic field H applied to the material M may be a static magnetic field (a continuous, constant magnetic field). The magnetic field H may be a pulsed magnetic field (a pulsed magnetic field). The start and end of the application of the magnetic field H may be performed by the control unit of the power supply mechanism controlling the power supplied to the first coil 41 and the second coil 42.
[0044] In this example, functional components 5 and 6, which function as heaters, heat the material M. The operation (temperature, etc.) of the functional components 5 and 6 may be controlled by a heating control device electrically connected to the functional components 5 and 6. Heat from the functional components 5 and 6 is transferred to the material M in the space S via the mold 2. More specifically, heat from the functional components 5 and 6 may be transferred to the material M via, for example, the portion of the mold 2 between the bottom surface 25a and the space S, and the portion of the mold 2 between the bottom surface 26a and the space S. Heating by the functional components 5 and 6 may end simultaneously with the time when the temperature of the material M reaches a predetermined temperature. The temperature of the material M may be measured, for example, by a temperature sensor (thermocouple, etc.) placed inside the mold 2.
[0045] In this example, the compression mechanism 3 compresses the material M. Specifically, the first pressurizing mechanism 33 and the second pressurizing mechanism 34 move the first punch 31 and the second punch 32 closer to each other in the Z-axis direction. This causes the first punch 31 and the second punch 32 to compress the material M positioned between the end faces 31a and 32a. At this time, the material M may be compressed by moving only the first punch 31 while keeping the second punch 32 fixed. Alternatively, the material M may be compressed by moving only the second punch 32 while keeping the first punch 31 fixed. In other words, it is sufficient that the first punch 31 and the second punch 32 move so that the distance between the surface 21 and the surface 22 becomes relatively close. In this embodiment, the material M is compressed by the compression mechanism 3 while a magnetic field H is applied by the magnetic field generating mechanism 4 and heating is performed on the material M by the functional components 5 and 6. Through the above process, a magnetic molded body is formed.
[0046] When a magnetic molded body is used in the manufacture of bonded magnets, the magnetic molded body may be demagnetized by applying a magnetic field (reverse magnetic field) that is oriented in the opposite direction to the magnetic field H described above. Even in a demagnetized magnetic molded body, the state in which the easy magnetization axis of each magnet particle in the magnetic molded body is oriented in the same direction as the magnetic field H is maintained. The demagnetization mechanism for demagnetizing the magnetic molded body may be provided as part of the manufacturing apparatus 1, or it may be provided as a separate component from the manufacturing apparatus 1. The configuration of the demagnetization mechanism is not limited. Subsequently, the demagnetized magnetic molded body may be heated to form a cured product of the magnetic molded body. When a magnetic molded body is used in the manufacture of bonded magnets, the material M may contain a thermosetting resin. Therefore, a cured product of the magnetic molded body may be formed by thermosetting the thermosetting resin in the magnetic molded body. Subsequently, the cured product of the magnetic molded body may be magnetized by applying a magnetic field that is oriented in the same direction as the magnetic field H to the cured product of the magnetic molded body. By magnetizing the cured product of the magnetic molded body, a permanent magnet (an anisotropic magnet magnetized in a specific direction) is obtained. The magnetic molded body formed through the steps of applying a magnetic field H, heating the material M, and compressing the material M may be a completed anisotropic bonded magnet. In this case, the demagnetization step described above may not be performed.
[0047] When a magnetic molded body is used in the manufacture of a sintered magnet, the magnetic molded body may be sintered to form a sintered body. The sintered body may be used as a permanent magnet (an anisotropic magnet magnetized in a specific direction). Before the magnetic molded body is sintered, it may be degreased by heating it at a temperature lower than its sintering temperature. The sintered body may be magnetized by applying a magnetic field that is oriented in the same direction as the magnetic field H mentioned above. The magnetized sintered body may be used as a permanent magnet.
[0048] Next, the formed magnetic molded body is removed from the mold 2. For example, first, the first pressing mechanism 33 removes the first punch 31 from the mold 2. Then, the second pressing mechanism 34 moves the second punch 32 from the surface 22 to the surface 21 of the mold 2. As a result, the magnetic molded body is pushed out by the second punch 32 and removed from the space S outside through the opening formed on the surface 21.
[0049] [Mechanism of Action and Effects] In the magnetic molded body manufacturing apparatus 1, functional components 5 and 6, which function as yokes, are arranged inside the mold 2 to guide the magnetic field H generated by the magnetic field generation mechanism 4 toward the magnetic molded body material M supplied to the space S of the mold 2. As a result, compared to the case where the yoke is arranged outside the mold 2, the functional components 5 and 6 that function as yokes are positioned closer to the magnetic molded body material M, so the magnetic field H applied to the material M can be made larger. This increases the orientation of the manufactured magnetic molded body and increases the residual magnetic flux density. Furthermore, in the magnetic molded body manufacturing apparatus 1, the functional components 5 and 6 that function as heaters (predetermined functions) also function as yokes. That is, there is no need to provide a yoke as a separate configuration from the functional components 5 and 6 that function as heaters (without making the manufacturing apparatus 1 a complex configuration), and magnetic molded bodies can be easily manufactured. Therefore, with the magnetic molded body manufacturing apparatus 1, magnetic molded bodies with high residual magnetic flux density can be easily manufactured.
[0050] Functional component 5 is positioned between the first coil 41 and space S, and the longitudinal direction of functional component 5 is aligned with the direction from the first coil 41 toward space S. Functional component 6 is positioned between the second coil 42 and space S, and the longitudinal direction of functional component 6 is aligned with the direction from the second coil 42 toward space S. This allows the magnetic field H generated by the magnetic field generation mechanism 4 to be efficiently applied to the material M of the magnetic molded body supplied to space S of the mold 2, making it possible to manufacture a magnetic molded body with a higher residual magnetic flux density.
[0051] Functional components 5 and 6 are heaters whose predetermined function is to heat the material M supplied to the space S. This eliminates the need to provide a yoke as a separate component from the heater, making it easy to manufacture magnetic molded bodies.
[0052] The mold 2 has a surface 23 facing the first coil 41, and the mold 2 has a recess 25 that opens on the surface 23. The functional component 5 is placed in the recess 25. The mold 2 also has a surface 24 facing the second coil 42, and the mold 2 has a recess 26 that opens on the surface 24. The functional component 6 is placed in the recess 26. As a result, the recess 25 in which the functional component 5 is placed is open on the surface 23 of the mold 2 facing the first coil 41, allowing the functional component 5 to be placed close to the first coil 41. Similarly, the recess 26 in which the functional component 6 is placed is open on the surface 24 of the mold 2 facing the second coil 42, allowing the functional component 6 to be placed close to the second coil 42. Therefore, the magnetic field H generated by the magnetic field generation mechanism 4 can be efficiently collected by the functional components 5 and 6, making it possible to manufacture a magnetic molded body with a higher residual magnetic flux density.
[0053] The distance D1 from the bottom surface 25a of recess 25 to space S is smaller than the depth D2 of recess 25. The distance D3 from the bottom surface 26a of recess 26 to space S is smaller than the depth D4 of recess 26. This allows the functional components 5 and 6 to be placed closer to the magnetic molded material M supplied to space S of the mold 2. Therefore, the magnetic field H generated by the magnetic field generation mechanism 4 can be efficiently applied to the magnetic molded material M supplied to space S of the mold 2, making it possible to manufacture a magnetic molded body with a higher residual magnetic flux density.
[0054] Functional component 5 is positioned between the first coil 41 and space S, and functional component 6 is positioned between the second coil 42 and space S. This allows the magnetic field H generated by the magnetic field generation mechanism 4 to be efficiently applied to the magnetic molded material M supplied to space S of the mold 2, making it possible to manufacture a magnetic molded body with a higher residual magnetic flux density.
[0055] [Second Embodiment] Referring to Figure 2, the manufacturing apparatus 1 for magnetic molded bodies according to the second embodiment will be described. Below, the differences from the manufacturing apparatus 1 according to the first embodiment will be mainly described, and common points may be omitted from the explanation. The shapes of the functional parts 5 and 6 according to this embodiment are different from the shapes of the functional parts 5 and 6 according to the first embodiment. Specifically, the functional part 5 according to this embodiment has a shape that becomes smaller as it moves from the first coil 41 toward space S. The shape of the functional part 5 becoming smaller as it moves from the first coil 41 toward space S means that the outer edge of the functional part 5, when viewed from the direction toward space S from the first coil 41 (X-axis direction), becomes smaller as it moves from the first coil 41 toward space S. The functional part 5 has a tapered shape that decreases in diameter as it moves from the first coil 41 toward space S. In this example, the functional part 5 has a frustoconical shape.
[0056] Functional component 5 has a top surface 5a located on the space S side (facing the material M) and a bottom surface 5b located on the first coil 41 side (facing the first coil 41). The width W1 of the top surface 5a is smaller than the width W2 of the bottom surface 5b. Width W1 is the maximum width of the top surface 5a, which in this example is the diameter. Width W2 is the maximum width of the bottom surface 5b, which in this example is the diameter. Width W2 is larger than the width W3 of functional component 5 in the X-axis direction. Width W3 is the maximum width of functional component 5 in the X-axis direction, which in this example is the distance between the top surface 5a and the bottom surface 5b.
[0057] The functional component 6 according to this embodiment has a shape that becomes smaller as it moves from the second coil 42 toward space S. The shape of the functional component 6 becoming smaller as it moves from the second coil 42 toward space S means that the outer edge of the functional component 6, when viewed from the direction toward space S (X-axis direction), becomes smaller as it moves from the second coil 42 toward space S. The functional component 6 has a tapered shape that decreases in diameter as it moves from the second coil 42 toward space S. In this example, the functional component 6 has a frustoconical shape.
[0058] The functional component 6 has a top surface 6a located on the space S side (facing the material M) and a bottom surface 6b located on the second coil 42 side (facing the second coil 42). The width W4 of the top surface 6a is smaller than the width W5 of the bottom surface 6b. Width W4 is the maximum width of the top surface 6a, which in this example is the diameter. Width W5 is the maximum width of the bottom surface 6b, which in this example is the diameter. Width W5 is larger than the width W6 of the functional component 6 in the X-axis direction. Width W6 is the maximum width of the functional component 6 in the X-axis direction, which in this example is the distance between the top surface 6a and the bottom surface 6b.
[0059] In this embodiment, functional component 5 is positioned between the first coil 41 and space S, and has a shape that decreases in size from the first coil 41 toward space S. Functional component 6 is positioned between the second coil 42 and space S, and has a shape that decreases in size from the second coil 42 toward space S. As a result, functional components 5 and 6 function as yokes that collect the magnetic field lines (magnetic flux) of the magnetic field H generated by the magnetic field generation mechanism 4 (first coil 41 and second coil 42) toward space S (material M). Therefore, the magnetic field H generated by the magnetic field generation mechanism 4 can be efficiently applied to the material M of the magnetic molded body supplied to space S of the mold 2, and a magnetic molded body with a higher residual magnetic flux density can be manufactured.
[0060] [Differentiation] This disclosure is not limited to the embodiments described above. Modifications of the embodiments described above will be described below. For example, in the embodiments described above, the functional components 5 and 6 were heaters, but the functional components 5 and 6 may be thermocouples having the function of measuring the temperature of material M supplied to space S as a predetermined function. That is, the functional components 5 and 6 have at least two functions, including the function of a thermocouple and the function of a yoke. In this case, the heater for heating the material M may be provided inside or outside the mold 2 as a separate component from the functional components 5 and 6. Each of the functional components 5 and 6, which are thermocouples, may be made of metal. In this modification, the functional components 5 and 6 are thermocouples having the function of measuring the temperature of material M supplied to space S as a predetermined function. This eliminates the need to provide a yoke as a separate component from the thermocouple, making it easy to manufacture a magnetic molded body.
[0061] The shapes of the functional components 5 and 6 are not limited to the shapes of the embodiments described above, as long as they function as yokes that guide the magnetic field H toward the material M supplied to space S. For example, in the second embodiment, the shapes of the functional components 5 and 6 are not limited to frustoconical shapes, but may have polygonal frustoconical shapes such as frustoconical shapes.
[0062] The coil axes of the first coil 41 and the second coil 42 do not necessarily have to be aligned in the direction in which the first coil 41 and the second coil 42 are aligned, and may be inclined. Inside each of the first coil 41 and the second coil 42, a yoke (e.g., an iron core) separate from the functional components 5 and 6 may be placed.
[0063] In the method for manufacturing a magnetic molded body, the order of the steps of applying a magnetic field H, heating the material M, and compressing the material M is not limited. The steps of applying a magnetic field H, heating the material M, and compressing the material M do not have to be performed simultaneously, and may be performed at different times. [Explanation of symbols]
[0064] 1...Manufacturing equipment (manufacturing equipment for magnetic molded bodies), 2...Mold, 3...Compression mechanism, 4...Magnetic field generation mechanism, 5,6...Functional parts, 25a,26a...Bottom surface, 23,24...Surface, 25,26...Recess, 41...First coil, 42...Second coil, H...Magnetic field, M...Material, S...Space.
Claims
1. A mold including a space into which the material for a magnetic molded body containing magnetic powder is supplied, A compression mechanism for compressing the material supplied to the space, A magnetic field generating mechanism having a pair of coils arranged to sandwich the mold, The mold comprises a functional component having a predetermined function, The aforementioned functional component further has the function of a yoke that guides the magnetic field generated by the magnetic field generation mechanism toward the material supplied into the space. Manufacturing equipment for magnetic molded bodies.
2. The functional component is positioned between one of the pair of coils and the space. The longitudinal direction of the functional component is aligned with the direction from one of the coils toward the space. The apparatus for manufacturing a magnetic molded body according to claim 1.
3. The functional component is positioned between one of the pair of coils and the space, and has a shape that becomes smaller as it moves from the one coil toward the space. The apparatus for manufacturing a magnetic molded body according to claim 1 or 2.
4. The functional component is a heater having the function of heating the material supplied to the space as its predetermined function. The apparatus for manufacturing a magnetic molded body according to claim 1 or 2.
5. The functional component is a thermocouple having the function of measuring the temperature of the material supplied to the space as its predetermined function. The apparatus for manufacturing a magnetic molded body according to claim 1 or 2.
6. The mold has a surface facing one of the pair of coils, The mold has a recess formed on its surface that opens up, The aforementioned functional component is disposed within the recess. The apparatus for manufacturing a magnetic molded body according to claim 1 or 2.
7. The distance from the bottom surface of the recess to the space is less than the depth of the recess. The apparatus for manufacturing a magnetic molded body according to claim 6.
8. Each of the two functional components comprises a pair of functional components, One of the pair of functional components is positioned between one of the pair of coils and the space. The other functional component of the pair is positioned between the other coil of the pair and the space. The apparatus for manufacturing a magnetic molded body according to claim 1 or 2.