Apparatus for manufacturing compression bonded magnets and method for manufacturing the same

Abstract

To provide a manufacturing device capable of enhancing the productivity of a compression-bonded magnet obtained by final molding of a preform.SOLUTION: A manufacturing device for manufacturing a compression bond magnet (M) according to the present invention includes a first molding machine (1) that pressurizes a magnet raw material (p) composed of a mixture or kneaded material of magnet particles and a binder resin to obtain a first compact (F1), a second molding machine (2) that pressurizes a first molded body to obtain a second molded body (F2), and a conveying machine 3 that moves a transfer jig (35) having a housing space (351) along the shape of the first molded body from the side of the first molding machine to the side of the second molding machine. When the housing space of the transfer jig, and the plurality of holes forming a first cavity and a second cavity are arranged at approximately the same positions, a plurality of compression bond magnets can be efficiently manufactured collectively.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a manufacturing apparatus for compression bonded magnets and the like.

Background Art

[0002] Permanent magnets used in electromagnetic devices (such as electric motors) include sintered magnets obtained by sintering magnet powders and bonded magnets obtained by bonding magnet powders with resins. Bonded magnets have a high degree of freedom in shape and are superior in formability to sintered magnets.

[0003] Bonded magnets mainly include injection bonded magnets obtained by injecting a molten mixture of magnet powder and thermoplastic resin into a cavity for molding, and compression bonded magnets obtained by heat-compression molding a mixture or kneaded product of magnet powder and thermosetting resin in a cavity. Compression bonded magnets usually have a higher proportion of magnet powder than injection bonded magnets and have high magnetic characteristics. Also, compression bonded magnets using thermosetting resin as a binder resin (binding material) are excellent in heat resistance and the like.

[0004] By the way, when manufacturing a compression bonded magnet, if powdery or granular magnet raw materials are directly filled into a high-temperature cavity, inhomogenization of the magnet raw materials (variation in the distribution of magnet particles and resin) and the like may occur in the cavity. Therefore, a manufacturing method of a compression bonded magnet has been proposed in which a preformed body obtained by low-pressure molding of magnet raw materials is loaded into a cavity and heat-compression molded (main molding). Descriptions related to this are, for example, in the following patent documents.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Patent Document 1 describes a resin composition for bonded magnets that is molded at low pressure (0.1~0.2 t / cm²) at room temperature (non-heated state). 2 A pre-compressed body (pre-molded body) subjected to approximately 10-20 MPa pressure is subjected to high-pressure molding in the high-temperature cavity of the main molding mold to produce a compressed bond magnet (main molded body). During this process, the pre-compressed body, which is prone to collapse and difficult to transport, is dropped by gravity into the cavity of the main molding mold located directly below the pre-molding mold.

[0007] In manufacturing methods (apparatus) like that described in Patent Document 1, pre-forming and main forming can only be performed alternately, and switching between pre-forming and main forming (process transition) takes time. In other words, it is difficult to improve the productivity (mass production) of compression bond magnets with such methods (apparatus).

[0008] This invention has been made in view of these circumstances, and aims to provide a new manufacturing apparatus, etc., that can efficiently manufacture compression bond magnets. [Means for solving the problem]

[0009] The inventors diligently researched how to solve this problem and conceived the idea of ​​separating the pre-forming area from the main forming area and transporting the pre-formed body from the pre-forming area to the main forming area using a transport jig. By realizing and developing this idea, the inventors completed the present invention described below.

[0010] Manufacturing equipment for compressed bonded magnets (1) The present invention is a manufacturing apparatus for compression bonded magnets, comprising: a first molding machine that pressurizes a magnet raw material consisting of a mixture or kneaded product of magnet particles and binder resin in a first cavity to obtain a first molded body; a second molding machine that pressurizes the first molded body in a second cavity to obtain a second molded body; and a conveying machine that moves a conveying jig having a storage space conforming to the shape of the first molded body from the first molding machine side to the second molding machine side.

[0011] (2) According to the present invention, the first molded body, which has been molded at low pressure, is transferred to a transport jig having a storage space that conforms to its shape, and transported from the first molding machine to the second molding machine. Therefore, even the first molded body, which is low in density and easily collapses, can be supplied to the second molding machine while maintaining its shape. Thus, according to the present invention, the first molded body can be transferred in good condition between the first and second molding machines, which can be operated independently, thereby improving the productivity and stabilizing the quality of compression bonded magnets.

[0012] Method for manufacturing compressed bonded magnets The present invention can also be understood as a method for manufacturing a compression bonded magnet. For example, the present invention may be a method for manufacturing a compression bonded magnet comprising: a first molding step of pressurizing a magnet raw material consisting of a mixture or kneaded product of magnet particles and binder resin in a first cavity with a first pressure to obtain a first molded body; a transfer step of moving the first molded body from the first cavity to a transfer jig having a housing space conforming to the shape of the first molded body; a transport step of transporting the transfer jig containing the first molded body to the second cavity side; a loading step of moving the first molded body from the transfer jig to the second cavity; and a second molding step of pressurizing the first molded body in the second cavity with a second pressure greater than the first pressure to obtain a second molded body.

[0013] Compression-bonded magnets / magnetic components The present invention can also be understood as a compression bonded magnet, a magnetic member (electromagnetic member) equipped with the compression bonded magnet, a method for manufacturing the magnetic member, etc. Hereinafter, the compression bonded magnet will also be referred to simply as a "bonded magnet" as appropriate in this specification.

[0014] "others" (1) In this specification, "first" and "second" are convenient designations for explanatory purposes. The molding according to the present invention is not limited to two stages, but may be three or more stages. In the case of two-stage molding, the low-pressure molding (first molding) is appropriately referred to as pre-molding, and the high-pressure molding (second molding) is referred to as main molding.

[0015] The specific (relative) density and disintegration properties of the first molded body (pre-molded body) are not relevant. The first molded body may have sufficient density and shape retention for handling. Furthermore, the number of molded bodies obtained in a single molding process may be single or multiple. In other words, the first and second molded bodies referred to in this specification may be a single body, multiple bodies, or a group. A group refers to a case where multiple molded bodies are morphologically or functionally correlated with each other.

[0016] (2) The storage space of the transport jig should be shaped to accommodate the first molded body and maintain its orientation and shape. For example, the storage space and the first cavity should consist of voids (gaps) that are substantially the same in shape (shape, arrangement, size, etc.). However, if the first molded body is to be transported to the storage space without collapsing, the storage space may be slightly (one size larger) than the first cavity. For example, the cross-section of the voids in the storage space may be slightly larger in the direction of pressure relative to the first cavity. The length of the storage space and the first cavity in the direction of pressure (also referred to as the "vertical direction" as appropriate) may be the same or different.

[0017] The first and second cavities should similarly consist of voids with substantially the same shape. However, the second cavity should be slightly larger (one size larger) than the first cavity (the cross-section of the void is slightly expanded) in order to ensure the loading of the first molded body. The length (vertical direction) of the second cavity is usually shorter than that of the first cavity.

[0018] The containment space and the second cavity should similarly consist of voids of substantially the same shape. Their size and length should be adjusted as appropriate. The above also applies when the first cavity, the second cavity, or the containment space consists of multiple or a group of voids.

[0019] (3) Unless otherwise specified, "x~y" as used herein includes the lower limit x and the upper limit y. Any numerical value included in the various numerical values ​​or ranges of numerical values ​​described herein may be used to create new lower or upper limits, such as a range "a~b". [Brief explanation of the drawing]

[0020] [Figure 1A] It is a schematic diagram showing a manufacturing apparatus (an example) of a compression bonded magnet. [Figure 1B] It is a perspective view showing an enlarged part of the manufacturing apparatus. [Figure 2A] It is a schematic diagram showing an example of a manufacturing process of a preform. [Figure 2B] It is a schematic diagram showing an example of a manufacturing process of the main formed body.

Embodiments for Carrying out the Invention

[0021] One or two or more constituent elements arbitrarily selected from the matters described in this specification can be added to the constitution of the present invention described above. The constituent elements related to the method can also be the constituent elements related to the object (apparatus, bonded magnet, member, etc.). Whether any embodiment is the best depends on the object, required performance, etc.

[0022] 《Manufacturing Apparatus》 (1) First molding machine The first molding machine usually includes a mold for forming a magnet raw material into a first molded body. The mold includes, for example, a die in which a first cavity is formed and a punch for pressing the magnet raw material in the first cavity. The punch consists of, for example, an upper punch and a lower punch and is driven by hydraulic pressure, electric power, etc. The tip of the punch has a form (shape, arrangement, size, etc.) along the first cavity.

[0023] The first molding machine may include a supply device (powder feeding device, hopper, etc.) for filling the first cavity with a compound or powdered magnet raw material. Also, when the magnet raw material is hot-pressed, a heater for heating the magnet raw material in the first cavity may be provided on the die or the like.

[0024] (2) Second molding machine The second molding machine may also be equipped with a molding die (e.g., a die and a punch) similar to the first molding machine. If the second cavity is a void (slot) formed in the material, the second molding machine only needs to be equipped with a punch that pressurizes the first molded body within the second cavity. The punch may be either an upper punch or a lower punch. The punch is driven by hydraulics, electric power, etc., and its tip is shaped to conform to the second cavity.

[0025] The second molding machine may include a heater for heating the second cavity and a magnetic field source (permanent magnet, electromagnet, etc.) for applying an oriented magnetic field to the second cavity.

[0026] (3) Conveyor The conveyor moves the conveying jig between the first molding machine and the second molding machine. The forward path of the conveying jig containing the first molded body and the return path of the conveying jig discharging the first molded body may be the same or different. In other words, the conveying jig may move back and forth linearly or in a loop. When the conveying jig moves approximately horizontally between the first and second molding machines, the configuration of the conveyor and manufacturing equipment can be simplified. Furthermore, if the conveying jig is moved smoothly along a (linear) rail or the like, it is possible to transport the first molded body at high speed while suppressing collapse and changes in posture.

[0027] (4) Loading machine Various methods can be considered for loading (dropping, dropping, transporting, etc.) the first molded body from the storage space of the transport jig into the second cavity. For example, if the first molded body is a single unit or has a simple shape, the first molded body can be loaded into the second cavity by gravity simply by moving (positioning) the transport jig onto the second cavity.

[0028] On the other hand, if the first molded body consists of multiple bodies, a loading machine (means) for controlling the loading of the first molded body into the second cavity may be provided. This makes it possible to stably load the entire first molded body into the second cavity.

[0029] The loading mechanism is, for example, a shutter that opens and closes on the underside of the containment space. When the shutter is closed, the first molded body is held in place so as not to fall off the transport jig. When the shutter opens, the first molded body can be lowered from the transport jig (loaded into the second cavity). The shutter opening operation should preferably be performed at a desired timing, for example, when the transport jig is in the second molding machine (particularly on the second cavity).

[0030] The shutter can be of any shape or drive mechanism. For example, the shutter may be plate-shaped, spiral-shaped, etc., and a drive mechanism suitable for its shape will be selected. The shutter may also move together with the transport jig. Such a shutter can be considered part of the transport machine.

[0031] (5) Guide If the size of the outlet of the containment space (e.g., the lower opening) and the inlet of the second cavity (e.g., the upper opening) are different, or if there is a step between the inlets and outlets, a guide may be provided to guide the first molded body from the containment space of the transport jig to the second cavity. This makes it easier to load the first molded body into the second cavity. The guide also makes it easier for the low-density, large-volume first molded body to be pressure-molded into the denser, smaller-volume second molded body.

[0032] Incidentally, there only needs to be at least one of each: the first molding machine, the second molding machine, the conveying machine, the conveying jig, etc., and they do not need to be in equal numbers. For example, there may be two or more first molding machines or conveying jigs for each second molding machine.

[0033] 《Manufacturing method》 (1) First molding process The first pressure applied to the magnet material is sufficient to obtain a first molded body that does not collapse during the transfer process from the first cavity to the transfer jig and during the transfer process from the first cavity side to the second cavity side.

[0034] To be precise, the first pressure is, for example, 0.1-50 MPa, 0.5-25 MPa, 0.1-10 MPa, and even 3-8 MPa. If the first pressure is too low, molding itself becomes difficult. If the first pressure is too high, it leads to cracking of the magnet particles and an increase in the density of the first molded body.

[0035] Such a first molded body has a relative density (ρ / ρ0), which is the ratio of the apparent density (ρ) to the true density (ρ0), of 40-80%, 50-70%, and even 55-65%. The true density is determined from the density and mixing ratio of the magnet particles and binder resin that make up the magnet raw material. The apparent density is determined by dividing the mass of the first molded body by its apparent volume (for example, the volume calculated from the external dimensions).

[0036] The first molding step may be performed by heating the magnet material (die) in the first cavity. For example, the first molding step may be a warm molding step in which the magnet material is pressurized at around the softening temperature of the binder resin.

[0037] (2) Transfer process Various methods (means) can be considered for transferring the first molded body from the first cavity to the storage space of the transfer jig. For example, the transfer jig may be placed above the first cavity, and the first molded body may be lifted from the first cavity and transferred to the storage space of the transfer jig. This makes it easier to transfer even low-density first molded bodies without them collapsing. The upward transfer of the first molded body can be performed, for example, by a knockout mechanism that moves the lower punch provided on the first molding machine upward.

[0038] When multiple separated first molded bodies are molded together in the first molding process, it is efficient to transfer all of these first molded bodies together into the storage space of the transfer jig during the transfer process. Naturally, the positions of the voids between the first cavity and the storage space should be aligned with respect to the transfer direction of the first molded body (for example, the vertical direction).

[0039] (3) Conveying process During the transport process, the first molded body is moved toward the second cavity while housed in the transport jig. The transport jig should stop at a position where the positions of each void between the second cavity and the housing space are aligned with respect to the loading direction (e.g., vertical direction) of the first molded body.

[0040] (4) Loading process Various methods (means) can be considered for transferring the first molded body from the storage space of the transport jig to the second cavity. For example, the first molded body may be lowered into the second cavity from a transport jig positioned above the second cavity. In this case, the first molded body may be allowed to fall naturally due to its own weight, or it may be guided from above to below using a lower punch provided on the second molding machine. In the latter case, the first molded body is more likely to be loaded into the second cavity without collapsing. Furthermore, when multiple first molded bodies are stored in the transport jig, it is efficient to transfer them all at once from the transport jig to the second cavity.

[0041] (5)Second forming process The second pressure applied to the first molded body can be appropriately adjusted within a range greater than the first pressure. For example, the second pressure can be 5-500 MPa, 10-250 MPa, 20-100 MPa, or even 30-50 MPa. If the second pressure is too high, cracking of the magnet particles (especially particles obtained by hydrogen treatment (HDDR, d-HDDR) of the magnet alloy), a decrease in the dimensional accuracy of the bonded magnet or component, etc. Incidentally, even without setting the second pressure too high (for example, below 100 MPa), a second molded body (bonded magnet) with high magnetic properties can be obtained.

[0042] The second molding process is preferably carried out in a temperature range where the binder resin softens or melts. This suppresses cracking of the magnet particles while achieving densification and high orientation of the bonded magnets. The molding temperature depends on the type of binder resin, but is, for example, 120-200°C or even 130-170°C.

[0043] When the magnet material contains anisotropic magnet particles (especially rare-earth anisotropic magnet particles), the second molding process may be carried out while applying an orientation magnetic field to the second cavity. The orientation magnetic field is applied, for example, in a direction intersecting (or even perpendicular to) the compression direction of the first molded body. The magnitude of the orientation magnetic field is, for example, 0.5 to 3 T and even 1 to 2 T. The orientation magnetic field is the magnetic flux density on the inner surface of the second cavity. The magnetomotive force source for the orientation magnetic field may be an electromagnet or a (rare-earth) permanent magnet. When loading the first molded body into the second cavity or removing the second molded body from the second cavity, the orientation magnetic field should preferably be shut off or reduced.

[0044] 《Magnet raw materials》 (1) The magnet raw material consists of a mixture or paste of magnet particles (powder) and binder resin (powder), and is in powder or granular form. The mixture may be a powder obtained by mixing the binder resin and magnet particles at room temperature, or it may be a granular form obtained by mixing the binder resin and magnet particles while heating. The paste is a granular form obtained by kneading (especially heated kneading) magnet particles and binder resin. The granular magnet raw material consists of composition particles (simply called "compounds") in which the binder resin is attached almost uniformly to the surface of the magnet particles. In kneaded compounds, the binder resin is usually attached more densely to the surface of the magnet particles than in mixed compounds.

[0045] By mixing or kneading the binder resin in a fluid state (softened or molten), cracking of the magnet particles can be suppressed. Solid (particulate, etc.) binder resin is preferably mixed or kneaded in a warm state (e.g., 40-120°C or even 80-100°C).

[0046] (2) The magnetic particles may be single-type or multiple-type. Multiple-type magnetic particles can be obtained by mixing powders that differ in at least one of the following: alloy composition, particle size (particle size distribution), properties (anisotropy / isotropy), etc.

[0047] The magnetic particles may be, for example, a mixture of coarse and fine powders with different average particle sizes. The average particle size of the coarse powder is, for example, 40-200 μm or even 80-160 μm. The average particle size of the fine powder is, for example, 1-10 μm or even 2-6 μm. The average particle size is determined, for example, by measurement using a laser diffraction particle size distribution analyzer (HELOS manufactured by Nippon Laser Co., Ltd.) (measurement using the Fraunhofer method).

[0048] The mass ratio of coarse powder to the total of coarse and fine powder (or the total magnet powder) is, for example, 60-90% by mass or even 65-80% by mass. In other words, the mass ratio of fine powder to the total is, for example, 10-40% by mass or even 20-35% by mass. Also, the ratio of magnet particles to the total of magnet raw materials (magnet particles and resin (including additives, etc.)) is, for example, 80-98% by mass or even 85-94% by mass.

[0049] Examples of magnetic particles include rare earth magnetic particles. Rare earth magnetic particles include NdFeB systems (based on Nd, Fe, and B), SmFeN systems (based on Sm, Fe, and N), and SmCo systems (based on Sm and Co). The magnetic particles may also be a mixture of coarse particles made of NdFeB anisotropic magnetic particles and fine particles made of SmFeN anisotropic magnetic particles or SmCo anisotropic magnetic particles. The magnetic particles may also contain rare earth isotropic magnetic particles or ferrite particles.

[0050] (3) The binder resin may be a thermoplastic resin or a thermosetting resin. Thermosetting resins are usually used for compression bonded magnets. Examples of thermosetting resins include epoxy resins, phenolic resins, melamine resins, urea resins, and unsaturated polyester resins. The binder resin as used herein includes the main component, curing agent, and various additives (e.g., surfactants, mold release agents, etc.).

[0051] The second molded article, made of thermosetting resin, is subjected to a curing treatment as appropriate. The heating temperature is, for example, 130-250°C or even 150-230°C. The curing treatment may be performed inside the second cavity or after it has been discharged from the second cavity.

[0052] Bonded magnets The bonded magnet may be the second molded body as is, or the second molded body may have undergone heat treatment (curing) or magnetization. Magnetization is performed, for example, by applying a magnetic field of about 2 to 6 T.

[0053] Bonded magnets may be those removed (discharged) from the second cavity after the second molding process, or they may be integrated with a housing (core, etc.) having a second cavity (magnet hole, etc.) during the second molding process. Examples of magnetic components in which bonded magnets are integrated into the cavity of a housing include the field elements (rotor, stator) of electric motors (vehicle drive motors, air conditioner motors, home appliance motors, etc.). Note that electric motors may be DC motors or AC motors. Furthermore, electric motors include not only motors but also generators.

[0054] The rotor may be, for example, an internal magnet motor (IPM) rotor in which bonded magnets are integrated into magnet holes (slots) formed on the inside, or a surface magnet motor (SPM) rotor in which bonded magnets are integrally formed on the outer surface. In either case, the number of magnetic poles is at least two.

[0055] In the case of IPM rotors, a bonded magnet is embedded in each magnetic pole. The magnetic holes (bonded magnets) of each magnetic pole may be multilayered or divided into multiple parts to increase the output power and efficiency of the motor. According to the present invention, even IPM rotors with a complex arrangement of bonded magnets can be efficiently manufactured while performing pre-forming and final molding. [Examples]

[0056] The present invention will be described in detail below, with examples of a manufacturing apparatus and method for an IPM rotor in which bonded magnets are integrated into slots (magnetic holes).

[0057] 《Manufacturing equipment》 Figure 1A schematically shows the outline of the IPM rotor manufacturing apparatus M (simply referred to as "apparatus M"). Figure 1B shows an enlarged perspective view of a part of it. Apparatus M comprises a pre-forming machine 1 (first molding machine), a main molding machine 2 (second molding machine), a conveyor 3, and a shutter 33 (loading machine). For the sake of explanation, the directions indicated by arrows in Figure 1A are considered to be up / down or left / right.

[0058] (1) The preforming machine 1 comprises an upper press table 11 and a lower press table 12 that move up and down along a support column 19 extending vertically upward from a base 10, an upper punch 141 and a lower punch 142 attached to them respectively, a table 13 located near the center of the upper and lower sections and extending horizontally, a powder box 16 that slides horizontally on the table 13, a hopper 17 that supplies compound p (magnetic material) to the powder box 16, and a die 15 located between the upper punch 141 and the lower punch 142 and built into the table 13.

[0059] As shown in Figure 1B, the die 15 is cylindrical, and a roughly U-shaped cavity 151 (first cavity) is formed on its outer circumference. The cavity 151 is a cylindrical void that penetrates the die 15 vertically, and its shape and arrangement correspond to the slot 251 (second cavity) of the rotor core 25. That is, the cross-sections (cross-sections in the left-right direction) of the cavity 151 and the slot 251 are roughly similar, but the cross-section of the cavity 151 is slightly smaller than that of the slot 251. However, the cavity 151 is longer vertically than the slot 251.

[0060] (2) The molding machine 2 comprises an upper press table 21 and a lower press table 22 that move up and down along a support column 29 extending vertically upward from a base 20, an upper punch 241 and a lower punch 242 attached to them respectively, an orientation die 27 that houses the rotor core 25, a magnetic field switch 271 that switches the orientation magnetic field H (see Figure 1B) applied to the slot 251 ON and OFF, and a table 23 that holds the orientation die 27 and the magnetic field switch 271 and moves up and down along the support column 29.

[0061] The rotor core 25 is for an 8-pole IPM and has eight roughly U-shaped slots 251 formed on its outer circumference. Upper guides 261 and lower guides 262, which are the molding jigs, are positioned on the upper and lower surfaces of the rotor core 25, respectively. The upper guides 261 and lower guides 262 are also cylindrical (their outer diameter is approximately the same as that of the rotor core 25), and eight roughly U-shaped guide holes 2611 and 2621 corresponding to the slots 251 are formed on their outer circumferences, respectively.

[0062] Slots 251, guide holes 2611, and 2621 are all cylindrical cavities that penetrate vertically. The upper guide 261, rotor core 25, and lower guide 262 are housed in the orientation mold 27 in that order, with each cavity aligned vertically (without any circumferential misalignment).

[0063] The guide hole 2611 has a gentle taper (funnel shape) in which the cross-section narrows from the top (towards the conveying jig 35) to the bottom (towards the rotor core 25), so that the preformed body F1 is guided from the storage space 351 of the conveying jig 35 to the slot 251 of the rotor core 25.

[0064] (3) The conveyor 3 includes a linear rail 31 that extends horizontally to the left and right above the table 13, and a conveying jig 35 attached to a slider 32 (see Figure 1B) that moves along the linear rail 31.

[0065] The shutter 33 is positioned approximately in the center of the molding machine 2 and moves open and closed from side to side. When the shutter 33 is closed, its upper surface and the upper surface of the table 13 become flush. The slider 32 and the shutter 33 are driven by a servo motor (not shown) and stop at a predetermined position.

[0066] 《Manufacturing method》 Figures 2A and 2B show an example of the process for manufacturing an IPM rotor R (simply referred to as "rotor R") using apparatus M. Specifically, the process is as follows:

[0067] (1) Preforming The lower punch 142 of the preforming machine 1 is inserted into the cavity 151 of the die 15, and the upper end surface of the lower punch 142 is aligned with the upper end surface of the table 13 (step S10). From this position (referred to as the "origin position"), the upper end surface of the lower punch 142 is lowered to a predetermined position corresponding to the amount of compound p filling (step S11).

[0068] The powder box 16 is moved onto the die 15, and the compound p is leveled and supplied to the cavity 151 (Step S12 / Magnet material supply process). Note that the die 15 may be heated to a warm state when supplying the compound p. The heating temperature should be such that, for example, the binder resin contained in the compound p softens on the inner wall surface of the cavity 151.

[0069] The upper punch 141 and / or the lower punch 142 are driven to compress the compound p in the cavity 151 at a predetermined molding pressure (first pressure) to obtain a pre-molded body F1 (step S13 / first molding step). The molding pressure may be such that the pre-molded body F1 maintains its shape (e.g., 0.1 to 0.5 MPa).

[0070] (2)Transfer The upper punch 141 is moved upward, and the slider 32 is moved along the linear rail 31 to position the transport jig 35 on the die 15 (step S14). At this time, the transport jig 35 is stopped at a position where the occupants of the storage space 351 and the cavity 151 are approximately aligned in the vertical direction.

[0071] The lower punch 142 is raised to the origin position to knock out the preformed body F1 from the cavity 151, and the preformed body F1 is transferred to the storage space 351 of the transfer jig 35 (step S15 / transfer process).

[0072] (3) Transport With the shutter 33 open (moved to the left), the rotor core 25 and the upper guide 261 and lower guide 262 are set inside the orientation mold 27 (step S20). At this time, the magnetic field switch 271 is turned OFF so that the orientation magnetic field H is not applied to the rotor core 25 (slot 251).

[0073] The rotor core 25 may also be preheated beforehand or heated by a heater built into the orientation mold 27. The heating temperature should be, for example, just enough to melt the binder resin contained in the compound p.

[0074] The shutter 33 is closed (moved to the right) (step S21). This makes the top surface of the table 13 and the top surface of the shutter 33 flush with each other.

[0075] The slider 32 is moved to the left along the linear rail 31, and the transport jig 35 containing the preformed body F1 is placed on the shutter 33 (step S22 / transport process). At this time, the transport jig 35 is stopped at a position where the accommodating space 351 and the openings of the slots 251 (guide holes 2611, 2621) are approximately aligned in the vertical direction.

[0076] (4) Loading The lower punch 242 is raised, and its upper end surface is positioned near the lower end surface of the lower guide 262. The shutter 33 is moved to the left and opened (step S23 / loading process). As a result, the preformed body F1 moves by its own weight from the storage space 351 into the guide hole 2611, slot 251, and guide hole 2621.

[0077] (5) Main molding The slider 32 is moved to the right along the linear rail 31, and the transport jig 35 is moved away from the orientation mold 27. The magnetic field switch 271 is turned ON, and the orientation magnetic field H is applied to the rotor core 25 (slot 251).

[0078] The upper punch 241 and / or lower punch 242 are driven to compress the preformed body F1 at a predetermined molding pressure (second pressure) (step S24 / second molding step). This results in a rotor R in which a bonded magnet F2 (second molded body / main molded body) is integrally molded in the slot 251 (second cavity). The molding pressure at this time is, for example, 10 to 50 MPa.

[0079] The magnetic field switch 271 is turned OFF, causing the upper punch 241 to retract upward and the lower punch 242 to rise. As a result, the rotor R is removed from the orientation die 27 along with the upper guide 261 and the lower guide 262.

[0080] The rotor R obtained in this way may be further subjected to heat treatment (e.g., curing), magnetization, rust prevention treatment, etc.

[0081] 《Magnet raw materials》 The magnet raw material is, for example, a granular compound obtained by mixing coarse powder (NdFeB-based anisotropic magnet powder) and fine powder (SmFeN-based anisotropic magnet powder) and then adding a binder resin and melt-mixing (kneading) the mixture. The coarse powder is produced, for example, by hydrogen treatment (d-HDDR). The binder resin is, for example, an epoxy resin (thermosetting resin) that is in powder form at room temperature.

[0082] For example, the mass ratio of coarse powder to total magnet powder is 60-80% by mass (fine powder: 20-40% by mass), the mass ratio of thermosetting resin to total magnet raw materials is 20-40% by mass (magnet powder: 60-80% by mass), and the density of the premolded product is 2-4 g / cm³. 3 (Relative density: 40-60%), the density of this molded body is 5-6 g / cm³ 3 That is the case.

[0083] As described above, according to the manufacturing apparatus of the present invention, even bonded magnets with complex shapes can be efficiently produced. [Explanation of Symbols]

[0084] M manufacturing equipment 1 Preforming machine 2 molding machines 3. Conveyor 33 Shutter 35 Conveying fixture 151 Cavity (First Cavity) 251 slots (second cavity) 351 Containment space

Claims

1. A first molding machine that obtains a first molded body by pressurizing a magnet raw material consisting of a mixture or kneaded product of magnet particles and binder resin in a first cavity, A second molding machine that pressurizes the first molded body in a second cavity to obtain a second molded body, The system includes a transporter that moves a transport jig having a storage space conforming to the shape of the first molded body from the first molding machine side to the second molding machine side, The housing space of the transport jig, the first cavity, and the second cavity each consist of a plurality of voids arranged substantially in the same manner. The second cavity is formed in the rotor core, The second molded body is a manufacturing apparatus for compression bond magnets, which are integrated with the rotor core.

2. Furthermore, the manufacturing apparatus for compression bond magnets according to claim 1, further comprising a shutter that switches between holding and lowering the first molded body housed in the transport jig that has moved to the second molding machine side.

3. Furthermore, the manufacturing apparatus for compression bond magnets according to claim 1 or 2, further comprising a guide for guiding the first molded body from the storage space of the transport jig to the second cavity.

4. The manufacturing apparatus for compression bond magnets according to any one of claims 1 to 3, wherein the conveying machine is capable of reciprocating the conveying jig substantially horizontally between the first molding machine and the second molding machine.

5. A first molding step involves pressurizing a magnet raw material consisting of a mixture or kneaded product of magnet particles and binder resin in a first cavity with a first pressure to obtain a first molded body, A transfer step of moving the first molded body from the first cavity to a transfer jig having a storage space conforming to the shape of the first molded body, A transport step of transporting the transport jig containing the first molded body to the second cavity side, A loading step of transferring the first molded body from the transport jig to the second cavity, The process includes a second molding step of pressurizing the first molded body in the second cavity with a second pressure greater than the first pressure to obtain a second molded body, The transfer process involves moving the separated multiple first molded bodies together into the storage space of the transfer jig. The loading process involves transferring the multiple first molded bodies together to the second cavity. The second cavity is formed in the rotor core, The method for manufacturing a compression bond magnet in which the second molded body is integrated with the rotor core.

6. The method for manufacturing a compression bond magnet according to claim 5, wherein the transfer step involves lifting the first molded body onto the transfer jig positioned above the first cavity.

7. The method for manufacturing a compression bond magnet according to claim 5 or 6, wherein the loading step involves lowering the first molded body from the transport jig positioned above the second cavity.

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