CN107615418A - The manufacture method of the analytic method of sintered anisotropic magnet and the sintered anisotropic magnet of use this method - Google Patents

The manufacture method of the analytic method of sintered anisotropic magnet and the sintered anisotropic magnet of use this method Download PDF

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Publication number
CN107615418A
CN107615418A CN201680027254.XA CN201680027254A CN107615418A CN 107615418 A CN107615418 A CN 107615418A CN 201680027254 A CN201680027254 A CN 201680027254A CN 107615418 A CN107615418 A CN 107615418A
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China
Prior art keywords
magnetic field
sintered
stress
shape
distribution
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CN201680027254.XA
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Chinese (zh)
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枣田充俊
南坂拓也
久村刚之
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Proterial Ltd
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Hitachi Metals Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
    • H02K15/02—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
    • H02K15/03—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies having permanent magnets

Abstract

The present invention provides a kind of analytic method and manufacture method of sintered anisotropic magnet, and it can establish simulation in the production process of sintered anisotropic magnet, and can obtain reasonable and appropriate manufacturing conditions.Methods described is by making magnetic its shaping is sintered so as to obtain the process of formed body and the formed body to producing so as to obtain the sintering circuit of sintered body while carrying out magnetic field orientating, the method parsed to the sintered anisotropic magnet produced, in the sintering circuit, the two stages of stress path for being divided into the unstressed process for not applying stress and application stress are parsed.

Description

The analytic method of sintered anisotropic magnet and the anisotropy sintering using this method The manufacture method of magnet
Technical field
The present invention relates to the analytic method of the sintering process of sintered anisotropic magnet and use each to different of this method The manufacture method of property sintered magnet, the sintered anisotropic magnet is that the magnet being orientated in magnetic field is sintered and made 's.
Background technology
In the whirlers such as stepper motor, multipole magnetized cylindric permanent magnet is widely used for.In actual use will It is with anisotropic radial anisotropic toroidal magnet and each with the anisotropic polarity of multipole on surface in radial direction Anisotropy toroidal magnet is applied as this cylindric anisotropy toroidal magnet.
Figure 21 is the figure for the direction of magnetization for representing polar anisotropic toroidal magnet therein, and shows that 10 is extremely magnetized Example.In the neighboring of the polar anisotropic toroidal magnet 11 of cylindrical shape, alternately five N poles are there are at an equal pitch 12nd, five S poles 13.As shown in Figure 21 arrow, the direction of magnetization is the direction of the arc-shaped from S poles 13 to N poles 12.
Due to this polar anisotropic toroidal magnet being orientated on the direction close to Halbach array, so that Magnetic flux between adjacent magnetic pole is flowed with arc-shaped in magnet, therefore the magnetic flux density on surface is high, and turns into sinusoidal wave shape Magnetic flux distribution.Thus, in the case where being assembled in motor, height output torque can not only be obtained, but also can obtain Obtain Low gullet torque.As so above-mentioned, the advantages of polar anisotropic toroidal magnet is than radial anisotropic toroidal magnet, is more, The utilization of polar anisotropic toroidal magnet is energetically promoted.
All the time, it has been proposed that relevant with the structure and its manufacture method of the anisotropy toroidal magnet of cylindrical shape Various technologies (patent document 1-4).In patent document 1-3, disclose structure on polar anisotropic toroidal magnet with And manufacture method；In patent document 4, structure and manufacture method on radial anisotropic toroidal magnet are disclosed.
Prior art literature
Patent document
Patent document 1：Japanese Unexamined Patent Application 64-27208 publications
Patent document 2：Japanese Unexamined Patent Publication 2003-257762 publications
Patent document 3：Japanese Unexamined Patent Publication 2005-44820 publications
Patent document 4：Japanese Unexamined Patent Publication 8-306519 publications
The content of the invention
Invent problem to be solved
Such as when making polar anisotropic toroidal magnet, typically to pass through following process.
First, such as to R-Fe-B alloy (R is the rare earth elements such as Nd, Pr, Dy) crushed so as to obtain magnetic. Magnetic core that is that radial center is set and extending in the axial direction and the mould (shaping for possessing the given size of coil in outer peripheral face side Mould) inner space in, fill the magnetic.Moreover, because pulse current caused by electric capacity electric discharge applies by coil and to magnetic Desired magnetic field, punch process is axially simultaneously carried out, so as to cylindric after being magnetized and (being applied with alignment magnetic field) Formed body.The process is molding procedure.
Secondly, as the formed body by obtained by inert gas, 1000~1100 DEG C or so and entered with the defined time Row sintering, so as to obtain sintered body.The process is sintering circuit.For the sintered body of gained, implement and used product The working process (particularly positive round processing) that shape is consistent, produces polar anisotropic toroidal magnet.
In above-mentioned sintering circuit, the formed body after orientation deforms because of sintering, but due to being anisotropy orientation, So its deflection with the direction of magnetization parallel (easy axis) and the direction vertical with magnetization (hard axis direction) Upper difference, it is difficult to predict deflection, the setting of the treatment conditions in mold design or sintering circuit is all not easy.In addition, by Then cylindric shape, therefore compared with non-cylindrical shape (such as rectangular shape), stress is easily accumulated and held It is easily rupturable, so at this point, the setting of the treatment conditions in mold design or sintering circuit is all not easy.
In the case where making sintered anisotropic magnet as described above, such as Imitating is not yet established：It can sentence Break and under what kind of manufacturing conditions in molding procedure and sintering circuit can finally to produce what kind of shape, magnetic characteristic Sintered anisotropic magnet, but pass through the rule of thumb based on trial result, it is determined that the treatment conditions of each operation.
Such as, it is necessary to consider that the shrinkage ratio in sintering circuit is come really in the case of the mould designed for obtaining formed body The size of fixed mold, but up to the present, the determination is the rule of thumb based on past trial result.In addition, in shaping work , it is necessary to which the size of the voltage of inductive charging is set as into optimal value, Yi Mian when being magnetized in sequence using the energization of pulse current In sintering circuit produce rupture, crackle, but this be also based on it is caused rupture, crackle occurrence frequency result (rule of thumb) And determine.
Thus, there are the following problems all the time：Based on experience up to the present, to set various manufacturing conditions, but This is not reasonable and appropriate manufacturing conditions.
Not only polar anisotropic toroidal magnet has above mentioned problem, and each comprising the radial direction produced by sintering circuit Block magnet (block-shaped, bowed shape magnet), the anisotropy block magnet of anisotropy toroidal magnet, polar anisotropic orientation Other kinds of anisotropy magnet including (block-shaped, bowed shape magnet) also has above mentioned problem.Particularly in polarity The local degree of orientation and alignment magnetic field vector in anisotropy toroidal magnet is different, thus to sintering when deformation or split Line occurrence frequency has an impact, and it is highly difficult to be predicted (parsing) to them.
In addition, less than as in the alignment magnetic field being fully oriented, it is known that if alignment magnetic field it is of different sizes if remanence Change intensity Br, HCJ HCJ, recoil relativepermeabilityμr as magnetic characteristic can change.Especially polarity respectively to In different in nature toroidal magnet, uniform alignment magnetic field can not be applied to toroidal magnet inside.Therefore, in each several part inside magnet Magnetic characteristic it is different, it is highly difficult that correctly predicted (parsing) is carried out to it.
The present invention is to complete in view of the foregoing, its object is to, there is provided a kind of solution of sintered anisotropic magnet The manufacture method of the sintered anisotropic magnet of analysis method and use this method, the parsing side of the sintered anisotropic magnet Method be in the production process of sintered anisotropic magnet, especially in sintering circuit establish simulation, and can obtain rationally and Appropriate manufacturing conditions.
Means for solving the problems
The analytic method of the sintered anisotropic magnet of the present invention, it is characterised in that the analytic method is to different to each Property the method that is parsed of sintered magnet, the sintered anisotropic magnet be through while the magnetic is carried out magnetic field orientating into Type is so as to obtaining the process of formed body and the formed body to producing is sintered so as to obtain the sintering circuit of sintered body and is made Produce, in the sintering circuit, be divided into the unstressed process that does not apply stress and apply the stress path of stress the two ranks Duan Jinhang is parsed.
In the analytic method of the sintered anisotropic magnet of the present invention, enter in the formed body to the magnetic by magnetization orientation In the sintering circuit of row sintering, the sintering circuit is divided into the unstressed process for not applying stress and the stress mistake for applying stress Journey, carry out different parsings.Due to carrying out different types of parsing according to the presence or absence of stress, therefore correctly parsing knot can be obtained Fruit.
The analytic method of the sintered anisotropic magnet of the present invention is characterised by, in the parsing of the unstressed process In, use the shrinkage factor of easy axis and the shrinkage factor in hard axis direction；In the parsing of the stress path, use The linear expansion coefficient of easy axis and the linear expansion coefficient in hard axis direction.
In the analytic method of the sintered anisotropic magnet of the present invention, easy axis/hard axis direction is used Anisotropic shrinkage factor and linear expansion coefficient, come parse formed body is sintered obtained by sintered body shape. Thus, it is possible to parse the correct shape of sintered body.
The analytic method of the sintered anisotropic magnet of the present invention is characterised by, the shrinkage factor and line is expanded system Several alignment magnetic fields according to the formed body and change.
The present invention sintered anisotropic magnet analytic method in, in the parsing of sintering circuit, using according into The alignment magnetic field of type body and the shrinkage factor and linear expansion coefficient to change.Therefore, it is possible to obtain the more accurate sintering bodily form The analysis result of shape.
The analytic method of sintered anisotropic magnet of the present invention is characterised by, the parsing bag in the sintering circuit Contain：In the process being sintered to formed body, shape before the stress path of application stress is entered during unstressed Row parsing, the shape at the end of sintering is parsed in stress path according to the shape before the stress path after the parsing And stress.
In the analytic method of the sintered anisotropic magnet of the present invention, to the stress of application stress during unstressed Shape before process is parsed, and is being sintered in stress path according to the shape before the stress path after parsing to parse At the end of shape and stress.
The analytic method of the sintered anisotropic magnet of the present invention is characterised by, according to the orientation magnetic of the formed body , obtain the magnetic characteristic distribution of the sintered body.
In the analytic method of the sintered anisotropic magnet of the present invention, it is contemplated that the alignment magnetic field of formed body, to sintering The magnetic characteristic distribution of body is parsed.Therefore, it is possible to obtain the analysis result of the correct magnetic characteristic distribution of sintered body.
The analytic method of sintered anisotropic magnet of the present invention is characterised by, after the sintering circuit, based on from The shape distortion of formed body makes alignment magnetic field Vector Rotation, and obtain institute into the analysis result of the deflection after sintering shape State the distribution of the alignment magnetic field vector of sintered body.
In the analytic method of the sintered anisotropic magnet of the present invention, the parsing knot of the deformation in sintering circuit Fruit, make alignment magnetic field Vector Rotation, and the alignment magnetic field vector distribution to sintered body parses.Therefore, it is possible to sintered The analysis result of the correct alignment magnetic field vector distribution of body.
The analytic method of the sintered anisotropic magnet of the present invention is characterised by, the sintered anisotropic magnet is entered Row magnetic field parses and/or demagnetization parsing.
In the analytic method of the sintered anisotropic magnet of the present invention, it is contemplated that made sintered anisotropic magnet Magnetic characteristic distribution, can carry out magnetic field parsing and/or demagnetization parsing.
The analytic method of the sintered anisotropic magnet of the present invention, it is characterised in that the analytic method is to different to each Property the method that is parsed of sintered magnet, the sintered anisotropic magnet be through while the magnetic is carried out magnetic field orientating into Type is so as to obtaining the process of formed body and the formed body to producing is sintered so as to obtain the sintering circuit of sintered body and is made Produce, the analytic method has following steps：Make alignment magnetic field that various change occur so as to produce sintered body in advance, to it Size and thermo-mechanical property are measured, and shrinkage factor and line are determined respectively in easy axis and hard axis direction The coefficient of expansion, parsing is made with database and the step of stored in advance by measurement result；To in molding procedure into The step of 3 D tropism Distribution of Magnetic Field of type body is parsed；Extract two-dimensional orientation magnetic field out from the 3 D tropism Distribution of Magnetic Field The step of distribution；In sintering circuit do not apply stress it is unstressed during, using according to the two-dimensional orientation magnetic field point Cloth and the shrinkage factor of easy axis and the shrinkage factor in hard axis direction to change, are parsed to deflection, and The step of obtaining the shape before the stress path of stress is applied；In the stress path of application stress in sintering circuit, Using the shape before the stress path as original shape, changed using according to the two-dimensional orientation Distribution of Magnetic Field The linear expansion coefficient of easy axis and the linear expansion coefficient in hard axis direction, are parsed to deflection and stress, And the step of obtaining shape and stress distribution；After sintering circuit, based on the shape distortion from formed body into sintering shape The step of analysis result of deflection afterwards, making alignment magnetic field Vector Rotation, and obtaining the alignment magnetic field vector distribution of sintered body； From the distribution of the magnetic characteristic of sintered body, the step of mapping out the magnetic characteristic distribution of the shape after being processed to sintered body.
The analytic method of the sintered anisotropic magnet of the present invention is characterised by, also with following steps：To described each The step of anisotropy sintered magnet carries out the step of magnetic field parsing and/or carries out demagnetization parsing.
The manufacture method of the sintered anisotropic magnet of the present invention is characterised by thering is following process：Prepare comprising tool The process for having the mould of mold cavity shapes and the pressing under magnetic field decompressor of electromagnetic field generating coil；Prepare magnet alloy powder Process；Using the pressing under magnetic field decompressor, the process being molded in magnetic field to the magnet alloy powder；To The process being sintered in the magnetic field by being molded the formed body produced, the mold cavity shapes are according to as follows Sintered anisotropic magnet analysis result, be designed less than reference set value as condition using the internal stress of sintered body , the step is as follows：Make alignment magnetic field that various change occur so as to produce sintered body in advance, in easy axis and difficulty Shrinkage factor and linear expansion coefficient are determined respectively on magnetization direction of principal axis, and parsing database and advance is made by measurement result The step of being stored；The step of being parsed to the 3 D tropism Distribution of Magnetic Field of the formed body in molding procedure；In agglomerant In sequence do not apply stress it is unstressed during, use and be distributed and the easy axis that changes according to alignment magnetic field Shrinkage factor and the shrinkage factor in hard axis direction, are parsed to deflection, and are obtained before the stress path of stress is applied Shape the step of；In sintering circuit application stress stress path in, using the shape before the stress path as Original shape, linear expansion coefficient and hard axis side using the easy axis for being distributed and being changed according to alignment magnetic field To linear expansion coefficient, the step of being parsed to deflection and stress, and obtain shape and stress distribution；In agglomerant After sequence, based on from the shape distortion of formed body into sintering shape after deflection analysis result, make alignment magnetic field vector revolve The step of turning, and obtaining the alignment magnetic field vector distribution of sintered body；From the magnetic characteristic distribution of sintered body, map out to sintered body The step of magnetic characteristic distribution of shape after being processed.
In the manufacture method of the sintered anisotropic magnet of the present invention, mold cavity shapes are respectively to different according to as described above Property sintered magnet analysis result, reference set value be less than using the internal stress of sintered body be designed as condition, use bag Include the pressing under magnetic field decompressor including the mould with above-mentioned mold cavity shapes.Thus, it is possible to it is easy to provide most suitable mould Tool, the mould can produce the sintered anisotropic magnet not cracked.
The manufacture method of the sintered anisotropic magnet of the present invention is characterised by, is preparing the pressing under magnetic field punching press In the process of device, the electromagnetic field generating coil is pole piece shape, closest with the die cavity of the pressing under magnetic field decompressor The distance between the coil at position, more narrower than farthest position.
In the manufacture method of the sintered anisotropic magnet of the present invention, by using this electromagnetic field generating coil, so that The stress of formed body is diminished, produce rupture after sintering even if very thin thickness, in sintered anisotropic magnet that also will not be, split Line.
The manufacture method of the sintered anisotropic magnet of the present invention is characterised by, is preparing the pressing under magnetic field punching press In the process of device, the electromagnetic field generating coil is more than four, and is arranged to the mould in the pressing under magnetic field decompressor The adjacent electromagnetic field generating coil is extremely different on chamber side.
In the manufacture method of the sintered anisotropic magnet of the present invention, the magnetized polarity that can be produced more than quadrupole is each Anisotropy toroidal magnet.
Invention effect
According to the analytic method of the sintered anisotropic magnet of the present invention, the anisotropy obtained by by sintering circuit The production process of sintered magnet, particularly can correctly it be parsed in sintering circuit.Based on the analysis result, can obtain Reasonable and appropriate manufacturing conditions are obtained, high efficiency when cost of manufacture decline etc. makes can be realized, can also carry out including and move back The magnetic field parsing of magnetic parsing.
In addition, according to the manufacture method of the sintered anisotropic magnet of the present invention, it is used to manufacture anisotropy burning making Tie magnet device before, can by whether can produce the sintered anisotropic magnet not cracked parsed from And study, and most suitable mould can just be made with few practical measurement number.
Brief description of the drawings
Fig. 1 is the hardware structure diagram for implementing the device of the analytic method of the sintered anisotropic magnet of the present invention.
Fig. 2 is the flow chart of the operating procedure for the analytic method for representing the sintered anisotropic magnet of the present invention.
Fig. 3 is the two-dimensional orientation Distribution of Magnetic Field for representing the half-shadow in the formed body of polar anisotropic toroidal magnet Figure.
Fig. 4 be represent in the easy axis direction, utilize the temperature after the parsing of sintering circuit and formed body/sintered body The image figure of relation between size.
Fig. 5 is the content (shrinkage factor and linear expansion coefficient) for representing the database used in the parsing of sintering circuit Figure.
Fig. 6 is the figure for the J-H curves for representing parameter of magnetic characteristic.
Fig. 7 is the figure for the content (various magnetic characteristics) for representing the database used in the parsing of sintering circuit.
Fig. 8 is the analysis result (alignment magnetic field distribution) represented in the sintering circuit of polar anisotropic toroidal magnet Figure.
Fig. 9 is the figure for representing the analysis result (shape) in the sintering circuit of polar anisotropic toroidal magnet.
Figure 10 is the figure for representing the analysis result (stress distribution) in the sintering circuit of polar anisotropic toroidal magnet.
Figure 11 is the figure for illustrating the rotation of alignment magnetic field vector.
Figure 12 A are to represent the threedimensional model (the polar anisotropic toroidal magnet being processed after sintering) after mapping Characteristic (BrMagnetic characteristic distribution) figure.
Figure 12 B are to represent the threedimensional model (the polar anisotropic toroidal magnet being processed after sintering) after mapping Characteristic (HCJMagnetic characteristic distribution) figure.
Figure 12 C are to represent the threedimensional model (the polar anisotropic toroidal magnet being processed after sintering) after mapping Characteristic (Br、HCJ, μ r maximum, minimum value and bulk averaged value) figure.
Figure 13 A are to represent the magnet monomer shape after being processed to the sintered body of polar anisotropic toroidal magnet In, analysis result (charging voltage during magnetization of the magnetic flux distribution of magnet surface under normal temperature (20 DEG C)：250V) Figure.
Figure 13 B are to represent the magnet monomer shape after being processed to the sintered body of polar anisotropic toroidal magnet In, analysis result (charging voltage during magnetization of the magnetic flux distribution of magnet surface under normal temperature (20 DEG C)：400V) Figure.
Figure 14 is represented in the magnet monomer shape after being processed to the sintered body of polar anisotropic toroidal magnet , demagnetization characteristic analysis result figure.
Figure 15 is represented in the magnet monomer shape after being processed to the sintered body of polar anisotropic toroidal magnet , BrThe figure of the analysis result of the slip distribution of value.
Figure 16 is the drawing in side sectional elevation for the mould structure for representing pressing under magnetic field decompressor.
Figure 17 is the profilograph for the mould structure for representing pressing under magnetic field decompressor.
Figure 18 is the figure for the analysis result for representing internal stress.
Figure 19 is the figure for the surface magnetic flux density waveform for representing polar anisotropic toroidal magnet.
Figure 20 is the figure for the surface magnetic flux density waveform for representing polar anisotropic toroidal magnet.
Figure 21 is the figure for the direction of magnetization for representing polar anisotropic toroidal magnet.
Embodiment
Below, based on the accompanying drawing for representing embodiments of the present invention, the present invention is described in detail.
It is each to the polarity produced by above-mentioned molding procedure, sintering circuit in addition, in the following embodiments Anisotropy toroidal magnet illustrates.Specifically, material is R-Fe-B alloy (composition：Nd is that 24.0 mass %, Pr are 7.0 mass %, Dy are that 1.16 mass %, Nb are that 0.15 mass %, Al is that 0.1 mass %, Co is that 2.0 mass %, Ga are 0.1 matter It is that 0.1 mass %, B is 0.95 mass %, remaining as Fe, density to measure %, Cu：2.5g/cm3).Crush the alloy and obtain micro- Powder.The micro mist of gained is filled in into magnetic pole has in the polar anisotropic toroidal magnet mould of 10 poles, and magnetic field is carried out making it It is molded while orientation, obtains formed body.Resulting formed body is sintered at 1090 DEG C, is cooled to normal temperature (20 DEG C), produce polar anisotropic toroidal magnet.The polar anisotropic toroidal magnet produced is as shown in figure 21 The 10 poles magnetization of circumferencial direction, and be cylindric polar anisotropic toroidal magnet, the polar anisotropic toroidal magnet It is external diameter 27mm, internal diameter 20mm, length 38mm size with the net shape after processing.To above-mentioned polar anisotropic annular The parsing of magnet illustrates.
Fig. 1 is the hardware structure diagram for implementing the device of the analytic method of the sintered magnet of the present invention.In Fig. 1,1 is By CPU (central processing unit (Central Processing Unit)), MPU (microprocessor (Micro Processing The analysis unit of composition such as Unit)), analysis unit 1 via bus 7 and storage part 2, interim storage portion 3, input unit 4, display part 5 with And output section 6 connects.
By analysis unit 1, various dissection process are carried out in sintered anisotropic magnet.Storage part 2 can use hard disk The external memories such as (Hard Disk) or SSD (solid state hard disc (Solid State Drive)), storage part 2, which can store, to be used for By analysis unit 1 operate the program of processing, while also store for carrying out the various databases required for dissection process.Face When storage part 3 can use DRAM (dynamic random access memory (Dynamic Random Access Memory)), SRAM The random access memory of volatibility such as (static RAM (Static RAM)), and the solution of analysis unit 1 will be utilized The data that analysis is handled and generated are temporarily stored in interim storage portion 3.
Input unit 4 has the input units such as keyboard, numerical key, and carries out operation instruction, data input etc..Display part 5 has There are the display devices such as liquid crystal panel, and show analysis result etc..Output section 6 has the output devices such as printer, and exports parsing As a result etc..
Below, the analytic method on sintered anisotropic magnet of the invention, will be with reference to for representing its operating procedure Fig. 2 flow chart illustrate.
<The preparation of parsing database>
Prepare the parsing database (shrinkage factor used in the analytic method of the sintered anisotropic magnet of the present invention And the data of linear expansion coefficient) (step S1).Make alignment magnetic field that various change occur in advance to burn so as to produce anisotropy The sample of magnet is tied, passes through sintered body size and TMA (Thermomechanical Analyzer：Thermomechanical analyzer), come Determine thermo-mechanical property.Here, the linear expansion coefficient as thermo-mechanical property is measured.In easy axis and difficult magnetic Change the measure of the enterprising line coefficient of expansion of direction of principal axis, parsing database is made by resulting measurement result, and in advance It is stored in storage part 2.And then magnetic characteristic is determined by B-H tracing instruments, gaussmeter equimagnetic characteristic detecting apparatus, pass through survey Determine result and be made parsing database, and be pre-stored within storage part 2.
<The dissection process of alignment magnetic field>
In the molding procedure for the formed body for producing the magnetic by magnetization orientation, to consider excitation supply constant, Caused vortex in mould structure part, the alignment magnetic field at each position of formed body is parsed, and to the three-dimensional of formed body Alignment magnetic field distribution is parsed (step S2).
<Alignment magnetic field distribution is taken out>
Extract two-dimensional orientation Distribution of Magnetic Field (step S3) out from the 3 D tropism Distribution of Magnetic Field of gained.For example, by cylindrical shape Alignment magnetic field distribution in the axial central cross section of the formed body of shape is converted into the data of two dimension.Now, can extract out in grid Each element relative to the time maximum field vector.
Fig. 3 is to represent in the formed body of the polar anisotropic toroidal magnet of specific example, half-shadow two-dimensional orientation The figure of Distribution of Magnetic Field.Fig. 3 allows for the distribution of the alignment magnetic field vector in the analytic modell analytical model after symmetry.In the machine of reality In be shaped to ring-type, the distribution of alignment magnetic field vector, the sagittal plane in Fig. 3 pole position are symmetrical, and it is in interpolar position Repeated in sagittal plane with the half period, periphery surface side forms alternate 10 poles (reference picture 21) of N-S.The direction of arrow represents magnetic field Direction, in addition, the size in the length expression magnetic field of arrow, the more long then magnetic field of length of arrow are bigger.The periphery surface side of formed body Bigger than the magnetic field of inner peripheral surface side, the interpolar opening position especially in outer peripheral face side turns into maximum field.
<Dissection process in sintering circuit>
Fig. 4 be represent in the easy axis direction, utilize the temperature after the parsing of sintering circuit and formed body/sintered body The image figure of relation between size.In Fig. 4, transverse axis represents temperature, and the longitudinal axis represents the size of formed body/sintered body, and with one Tie up the change in size that (such as easy axis) represents the temperature relative to sintering circuit.In sintering circuit, from normal temperature (20 ℃：Fig. 4 A points) start to heat formed body, and it is heated to (1090 DEG C of sintering temperature：Fig. 4 B points), then, by Curie (340 DEG C of temperature：Fig. 4 C points), it is back to (20 DEG C of normal temperature：Fig. 4 D points), and obtain sintered body.
Here, the range of temperature (scope from A points by B points to C points in Fig. 4) from normal temperature to Curie temperature It is not produce the scope (unstressed process) of stress in the state of each particle during crystal boundary is liquid phase shrinks.On the other hand, from The Wen Duxiajiang scopes of Curie temperature to normal temperature are the freedom of firm, each particle of crystal boundary (in Fig. 4 from C points to the scope of D points) Degree disappearance simultaneously produces the scope (stress path) of stress.
In the present embodiment, be divided into unstressed the two stages of process and stress path to sintering parsed (step S4 and step S5).Specifically, in sintering circuit, do not apply stress it is unstressed during, using according to the two dimension The shrinkage factor of easy axis and the shrinkage factor in hard axis direction that alignment magnetic field is distributed and changed, enter to deflection Row parsing, and obtain the shape (step S4) before the stress path of stress is applied.Shrinkage factor used herein refers to, Come since each alignment magnetic field for the parsing database being made in step S1 and all directions (easy axis and difficult magnetization Direction of principal axis) in, the relation between the temperature and the size of formed body/sintered body that are made in expression sintering circuit as shown in Figure 4 Figure, A points and C points are connected with straight line, shrinkage factor is obtained by the gradient of the straight line.Then, in sintering circuit, applying should In the stress path of power, using the shape before the stress path as original shape, using according to the two-dimensional orientation magnetic field The linear expansion coefficient for the easy axis for being distributed and changing and the linear expansion coefficient in hard axis direction, to deflection with And stress is parsed, and obtain shape and stress distribution (step S5).Linear expansion coefficient used herein refers to, is coming Since each alignment magnetic field and all directions (easy axis and hard axis of the parsing database being made in step S1 Direction) in, the graph of a relation between the temperature and the size of formed body/sintered body that are made in expression sintering circuit as shown in Figure 4, C points and D points are connected with straight line, linear expansion coefficient is obtained by the gradient of the straight line.
Fig. 5 is the content (shrinkage factor and linear expansion coefficient) for representing the database used in the parsing of sintering circuit Figure.In Figure 5, relative to alignment magnetic field, by temperature from shrinkage factor when being heated to being cooled to 340 DEG C after 1090 DEG C for 20 DEG C Change, the change with temperature from linear expansion coefficient when being cooled to 20 DEG C for 340 DEG C, respectively in easy axis and difficult magnetic Change and be indicated on direction of principal axis.
Like this, relevant sintering is parsed due to being divided into unstressed the two stages of process and stress path, so The correct shape of the sintered body produced in sintering circuit, stress can be parsed.Further, since according to alignment magnetic field Distribution, and shrinkage factor and linear expansion coefficient used in making change, so correct analysis result can be obtained.
It is distributed according to the alignment magnetic field extracted out by step S3, obtains the magnetic characteristic distribution of the sintered body of gained.The magnetic obtained Characteristic is as follows, Br：Residual magnetic flux density；HCJ：Coercivity；μr：Recoil relative permeability；μk：Sagging relative permeability；α：Br's Temperature coefficient；β：HCJTemperature coefficient；R：The curvature of knick point (knick point).Fig. 6 is to represent their parameter of magnetic characteristic The figure of J-H curves.
The data of various magnetic characteristics used in the dissection process of magnetic characteristic distribution are to make in advance in step sl Various change occurs for alignment magnetic field so as to produce sintered body, and magnetic spy is determined by B-H tracing instrument equimagnetic characteristic detecting apparatus Property, parsing database is made by measurement result, and be stored in storage part 2.
Fig. 7 is the figure for the content (various magnetic characteristics) for representing the database used in the parsing of sintering circuit.In Fig. 7 In, illustrate above-mentioned seven kinds of magnetic characteristic (B according to alignment magnetic fieldr、HCJ, μ r, μ k, α, β, R) value.
Fig. 8 is the analysis result (alignment magnetic field distribution) represented in the sintering circuit of polar anisotropic toroidal magnet Figure, and the charging voltage discharged by electric capacity when carrying out magnetic field orientating is being set to 250V situation and is being set to 400V situation Under, illustrate in two examples alignment magnetic field distribution.Capacitance is 5000 μ F.In the interpolar position of outer peripheral face side, orientation Magnetic field is maximum, minimum in the inner peripheral surface side alignment magnetic field relative with pole position.As a result it is that the size of alignment magnetic field is with charging electricity The raising of pressure and increase.
Fig. 9 is the figure for representing the analysis result (shape) in the sintering circuit of polar anisotropic toroidal magnet, and table The shape of having shown formed body, the shape for the sintered body obtained by dissection process, pass through the detailed of the shape of the sintered body of practical measurement Thin size.In fig.9, the unit for representing the numerical value of shape is mm.Shape by the sintered body of practical measurement is, to multiple burnings The average value for the size that knot body is measured and obtained.Analysis result is as follows：The average value of internal diameter is 19.26mm, and external diameter is put down Average is 27.91mm.Shape by the sintered body of practical measurement is as follows：The average value of internal diameter is 19.23mm, and external diameter is averaged It is worth for 27.95mm.In the case of by analysis result compared with the result of practical measurement, the error of internal diameter is+0.03mm (error is+0.16%), the error of external diameter is -0.04mm (error is -0.14%), thus it can be appreciated that can be right with high accuracy Deformation in sintering circuit is parsed.
Figure 10 is the figure for representing the analysis result (stress distribution) in the sintering circuit of polar anisotropic toroidal magnet, And in the case where the charging voltage discharged by electric capacity when carrying out magnetic field orientating to be set to 250V situation and is set to 400V, Illustrate the stress distribution of the circumferencial direction composition in two examples.Capacitance is 5000 μ F.Relative with interpolar position Inner peripheral surface side, tensile stress is maximum, and the pole position compression stress in outer peripheral face side is maximum, if as a result, improving charging voltage Then stress increase.Due to the correct stress distribution in sintering circuit can be parsed by them, so by analysis result, Cope with because mould design alteration or condition of molding change etc. and caused by rupture, crackle.
<The calculating of alignment magnetic field vector after deformation>
Obtain the distribution (step S6) of the alignment magnetic field vector of the sintered body after being deformed in sintering circuit.
Deformed in sintering circuit because of anisotropic shrinkage, therefore it is believed that the formed body before sintering takes It is different from the alignment magnetic field vector of the sintered body after sintering to magnetic vector.Thus, based on the deformation in step S4 and S5 The analysis result of amount, make alignment magnetic field Vector Rotation by each grid.
Figure 11 is the figure for illustrating the rotation of the alignment magnetic field vector, and Figure 11 A represent the model of element, and Figure 11 B are represented Alignment magnetic field vector before deformation, Figure 11 C represent the alignment magnetic field vector after deformation.As shown in Figure 11 A, element is by four sections Point surrounds what is formed.As shown in Figure 11 B, in element before being deformed, the extended line of alignment magnetic field vector is stored with and component outline The point of intersection.In this example embodiment, starting point is side, the cutting c that will be made up of node 3 and node 4：D point；Terminal is by by saving The side of point 1 and the composition of node 2, cutting a：B point.Moreover, by the way that this definition is applied to because sintering is and the member that deforms Part, so as to which the alignment magnetic field vector after deformation as shown in Figure 11 C, can be obtained.The present inventor to material, alignment magnetic field it is big The shape of small, gained magnet, the species of magnet (polar anisotropic toroidal magnet, radial anisotropic toroidal magnet), magnetic The various conditions such as the number of magnetic poles of body are combined and tested, it was found that above-mentioned definition.
<Mapped to the magnetic characteristic of threedimensional model>
Typically, polar anisotropic toroidal magnet be the external diameter, internal diameter and axial end of sintered body are processed from And turn into final shape of product.When carrying out the magnetic field comprising demagnetization parsing to final shape of product and parsing, it is necessary to obtain Magnetic characteristic distribution in final shape of product.Thus, from the magnetic characteristic distribution of sintered body, it have mapped and sintered body is carried out The magnetic characteristic distribution (step S7) of shape after processing.
Magnetic characteristic distribution (the B of sintered bodyr、HCJ, μ r, μ k, α, β, R) be, according to the alignment magnetic field obtained in step S3 point Cloth, and the content (the various magnetic characteristics of measured in advance) based on database as shown in Figure 7 above and be configured in each element.Burn The distribution of the alignment magnetic field vector of knot body is obtained in step s 6.
Shape and chi due to the grid of the shape after being processed to sintered body, with having parsed the grid after sintered body Very little difference, therefore the interpolating function of FInite Element can be used, it is special to the magnetic comprising alignment magnetic field vector between different grids Property distribution mapped.In the case of the present example, it is two dimension to have parsed the grid after sintered body, by the sintering bodily form after processing Shape carries out magnetic field parsing with three-dimensional, therefore, is reflected as the shape after being processed in the axial direction without distribution, three-dimensional sintered body It is mapped to grid.
Figure 12 A-C are to represent that the threedimensional model after mapping (is directed to charging voltage when being magnetized by electric capacity electric discharge 250V is set to, perform orientation process and sinters the polar anisotropic toroidal magnet reprocessed afterwards, the three-dimensional after being simulated Model) characteristic figure, Figure 12 A represent BrMagnetic characteristic distribution, Figure 12 B represent HCJMagnetic characteristic distribution, Figure 12 C represent Br、 HCJ, μ r maximum, minimum value and bulk averaged value.Because in outer peripheral face side, alignment magnetic field is big, therefore BrBig and HCJIt is small, Because alignment magnetic field is smaller than periphery surface side in inner peripheral surface side, so BrSmall and HCJGreatly.
<Magnetic field parses>
Using the shape after being processed to sintered body, magnetic field parsing (step S8) is carried out.Figure 13 A, 13B are represented right Magnet monomer shape after the sintered body of anisotropy toroidal magnet is processed (is 27mm with external diameter, internal diameter 20mm, length Spend the cylindric polar anisotropic toroidal magnet for 38mm sizes) in, the magnetic flux of magnet surface under normal temperature (20 DEG C) The figure of the analysis result of Density Distribution.In Figure 13 A, 13B, illustrate charging when being magnetized by electric capacity electric discharge is electric Pressure is set to 250V situation (Figure 13 A) and is set in 400V situation (Figure 13 B), the analysis result in two examples, but also The result of practical measurement is illustrated together.Here, the surface magnetic flux density of the sintered body of practical measurement is after being determined with gaussmeter Result.
It is possible thereby to understand that the result of analysis result and practical measurement is unanimous on the whole.In addition, according to present embodiment, occur Low THD (Total Harmonic Distortion：Higher hamonic wave distortion rate), it is possible thereby to which understanding can be solved with high accuracy Analyse polar anisotropic toroidal magnet.
<Demagnetization parsing>
The demagnetization characteristic of sintered anisotropic magnet to producing is parsed (step S9).Figure 14 is represented to pole Property anisotropy toroidal magnet sintered body be processed after magnet monomer shape (have external diameter be 27mm, internal diameter 20mm, Length is the cylindric polar anisotropic toroidal magnet of 38mm sizes) in, the figure of the analysis result of demagnetization characteristic, and table Be shown as demagnetization rate, be heated to demagnetize evaluation temperature before and after normal temperature (20 DEG C) under magnetic flux density rate of descent.Scheming In 14, illustrate and charging voltage when being magnetized by electric capacity electric discharge is being set to 250V situation (solid line) and is being set to 400V Situation (dotted line) under, the analysis result in two examples, but also illustrate the result of practical measurement together.
If by the result of practical measurement compared with analysis result, the parsing precision of demagnetization rate is about 10~20 DEG C Left and right, when raising charging voltage makes alignment magnetic field become big, HCJReduce, demagnetization rate becomes big trend and surveyed in analysis result and reality It is all consistent in fixed result, and can confirm that out and demagnetization parsing can be carried out with enough precision.In addition, magnetic field analyzing step, Demagnetization analyzing step can be selected according to the parsing purpose of sintered anisotropic magnet.In the present invention, it is contemplated that make After the magnetic characteristic distribution of the sintered magnet gone out, magnetic field parsing, demagnetization parsing can be carried out.
Figure 15 is to represent (the tool of the magnet monomer shape after being processed to the sintered body of polar anisotropic toroidal magnet The cylindric polar anisotropic toroidal magnet that it is 27mm to have external diameter, internal diameter 20mm, length are 38mm sizes) in, Br The figure of the analysis result of the slip distribution of value, and illustrate and be set to by charging voltage when being magnetized by electric capacity electric discharge 250V, perform orientation process and sinter the analysis result for the polar anisotropic toroidal magnet reprocessed afterwards.In fig.15, table The solution in the situation (Figure 15 A) that demagnetization evaluation temperature is 100 DEG C and the situation (Figure 15 B) that demagnetization evaluation temperature is 120 DEG C is shown Analyse result.
As a result it is as follows：The B of interpolar position in outer peripheral face siderThe reduction of value is bigger than pole position, and with end phase Than the B of axial central portionrThe slip of value becomes big.
Due to according to present embodiment, high-precision analysis result can be obtained, therefore using the analysis result, can play Go out effect as described below.Due to can correctly be parsed to the deflection in sintering circuit, so mould can be optimized Shape, the mould is used to make formed body, and can design the good mould of qualification rate.Further, since in molding procedure In the various manufacturing conditions such as alignment magnetic field formation condition can be optimized, therefore can realize with low cost and effectively make Make sintered anisotropic magnet.And then due to without using the result after actual fabrication or measure, and use the solution by simulating Result is analysed, therefore, it is possible to study a variety of sintered anisotropic magnets in a short time, and anisotropy sintering magnetic can be improved The productivity ratio of body.
In addition, the operating procedure of above-mentioned analytic method is an example.In step s 2, to consider that excitation supply is normal Number, the caused vortex in mould structure part, are parsed to the alignment magnetic field at each position of formed body, and to formed body Two-dimensional orientation Distribution of Magnetic Field is parsed, it is also possible to obtain same effect.In addition, in step s3, obtained from step S2 3 D tropism Distribution of Magnetic Field in extract out 3 D tropism Distribution of Magnetic Field, it is also possible to obtain same effect.
Below, the method on manufacturing sintered anisotropic magnet using above-mentioned analytic method, with polar anisotropic Illustrated exemplified by the manufacture method of toroidal magnet.
<The design process of the mold cavity shapes of pressing under magnetic field decompressor and the preparatory process of pressing under magnetic field decompressor >
According to the analysis result of the analytic method acquisition by above-mentioned sintered anisotropic magnet, to be designed for being shaped to institute The mold cavity shapes of the pressing under magnetic field decompressor of the polar anisotropic toroidal magnet of intended shape.
In the mould as polar anisotropic magnetic field orientating, when the internal diameter is changed relative to defined external diameter, It is divided into the unstressed process for not applying stress and the two stages of stress path for applying stress, with the analytic method of the present invention How the internal stress of formed body is changed and is parsed.By the analysis result, by because of the application stress in two stages Stress path and cause the value of the internal stress of the sintered body of rupture or crackle, as reference set value, to consider finished product The conditions of molding such as the shape of polar anisotropic toroidal magnet, electromagnetic field generating coil, current value, compact density, so as to less than this Reference set value, mold cavity shapes are set, produce the mould of pressing under magnetic field decompressor, with obtain it is desired into The shape of type body.
Figure 16 and Figure 17 is the drawing in side sectional elevation and profilograph for the mould structure for representing pressing under magnetic field decompressor. In Figure 16 and Figure 17,21 be mould, and 22 be magnetic core, and 23 be electromagnetic field generating coil, and 24 be die cavity, and 25 be upper punching, and 26 are Lower punching, 27 be annulus.
Pressing under magnetic field for manufacturing polar anisotropic toroidal magnet has with decompressor：Mould is configured at same heart shaped In the annulus of tool 21 and section is the circular magnetic core 22 being made up of nonmagnetic material, and mould 21 is by pillar supporting, magnetic core 22 And pillar is all supported by lower frame.By the upper punching 25 being made up of the nonmagnetic material of tubular and lower punching 26, it is respectively embedded into In space between mould 21 and magnetic core 22.The periphery surface side of upper punching 25 and lower punching 26 is polygon, inner circumferential surface Side is the circle corresponding with the shape of magnetic core 22.Lower punching 26 is fixed on substrate, on the other hand, upper punching 25 fixed In upper frame.Upper frame is connected with upper hydraulic cylinder.Mould 21 is cylindrical shape, in the inner surface shape of the mould 21 of cylindrical shape Into multiple grooves, electromagnetic field generating coil 23 is embedded in each groove.In the annular that the inner surface setting of mould 21 is manufactured by nonmagnetic material Sleeve 27, to cover groove.Between annulus 27 and magnetic core 22 and upper punching 25 and lower punching 26, it is empty to form shaping Between.
In addition, the periphery surface side of upper punching 25 and lower punching 26 is polygon, inner circumferential surface side is the shape with magnetic core 22 The corresponding circle of shape, but be not limited thereto, periphery surface side can be circular, and inner peripheral surface side can also be polygon.At this In the case of, the magnetic core 22 being made up of nonmagnetic material is polygon.
Electromagnetic field generating coil 23 in each groove is configured to, electric current is flowed on the direction vertical with the upper surface of mould 21 It is dynamic, the electromagnetic field generating coil 23 in each groove is connected into, is alternately opposite the sense of current of circumferentially adjacent coil.If Electric current is flowed in electromagnetic field generating coil 23, then produce magnetic flux flows in molding space, bump against in magnetic flux and annulus 27 Point on, the magnetic pole of the magnetic that along the circumferential direction sequentially forms S, N, S, N ... alternately change.Now, electromagnetic field generating coil 23 is matched somebody with somebody It is set to so that the position on the side of the polygon of the position of the magnetic pole formed by electromagnetic field generating coil 23 and peripheral part side is in circumference It is unanimous on the whole on direction.
Shrinkage degree of the sintered anisotropic magnet because of the differently- oriented directivity of magnetic and in sintering is different.In polarity respectively to different Property toroidal magnet in the case of, if manufacturing magnet using internal diameter and external diameter are all circular die cavitys, after sintering, outside diameter The position of pole become flat, interpolar becomes relatively prominent shape (having the polygon on summit in interpolar), and internal side diameter becomes The polygon corresponding with the deformation of outside diameter or the circle with depression on the part that external diameter side protrudes.It is but this Deformation during sintering, orientation when will not hinder the polar anisotropic to be orientated and with effective inner diameter shape on the contrary, therefore, at this In the implementation of invention, the summit of the polygon of magnetic core 22 and the position consistency of magnetic pole are configured to.
In addition, the shape of coil is not particularly limited, but it is preferably, electromagnetic field generating coil is pole piece shape, with punching press It is the distance between coil at the immediate position of die cavity of device, more narrower than farthest position.Occurred by using this magnetic field Coil, so that the internal stress of formed body diminishes.Because the internal stress of formed body diminishes, even if after external diameter eliminates internal diameter Polar anisotropic toroidal magnet thickness it is thinner, in polar anisotropic toroidal magnet after sintering also without rupture, Crackle.More preferably, in terms of cross section, the shape of pole piece front end is triangle.
<The preparatory process of magnetic>
Preferably, it is divided into coarse crushing and finely divided magnetic is crushed.For example, on actually by R (R be Nd, Pr, The rare earth elements such as Dy), Fe, B form raw alloy coarse crushing, preferably with bruisher, jaw crusher, Blang's pulverizer (brown mill), dry pan, hydrogen crushing etc. carry out coarse crushing, preferably with jet pulverizer, vibromill, ball mill etc. Carry out finely divided.For anti-oxidation, carried out preferably using organic solvent or inert gas and in non-oxidizing atmosphere.Crush Granularity is preferably 2~8 μm (F.S.S.S).During less than 2 μm, because the active height of magnetic causes vigorous oxidation, therefore when sintering Deformation is big, and magnetic characteristic can also deteriorate.During more than 8 μm, the crystal particle diameter after sintering becomes big, easily causes magnetization inversion, causes to rectify The decline of stupid power.
<Molding procedure>
The shaping of polar anisotropic sintered ring magnet is carried out using above-mentioned pressing under magnetic field with decompressor.Pass through Powder batcher, the magnetic produced is filled in after the die cavity 24 of above-mentioned pressing under magnetic field decompressor, makes punching Hole 25 declines, and after molding space is formd with punching 25, lower punching 26, mould 21 and magnetic core 22, is applying magnetic field Meanwhile it is molded untill defined density.Here, in order that magnetic be orientated and to molding space apply magnetic field intensity, Preferably more than 159kA/m, more preferably more than 239kA/m.When the intensity of alignment magnetic field is less than 159kA/m, magnetic takes To insufficient, good magnetic characteristic can not be obtained.Briquetting pressure is preferably 0.5~2ton/cm2.Less than 0.5ton/cm2When, The weakened of formed body is easily broken.In addition, more than 2ton/cm2When, the orientation disorder of magnetic, magnetic characteristic declines.
<Sintering circuit>
Formed body after shaping is sintered.It is preferred that carried out in vacuum or argon gas atmosphere and at 1000~1150 DEG C Sintering.During less than 1000 DEG C, because of sintering deficiency, and required density can not be obtained, magnetic characteristic declines.During more than 1150 DEG C, Deformed because of excess agglomeration or the decline of magnetic characteristic.
In sintering circuit, general Mo plates used can be used.Mo plates are put into the heatproof container for used Mo, Formed body is placed thereon to be sintered.In order to prevent sintered body to be sintered on Mo plates, Mo plates are preferably made by machining etc. Surface roughness improve, to reduce the area that is contacted with formed body.It is rolling stock and the low feelings of surface roughness in Mo plates Under condition, the sintering of sintered body and Mo plates easily occurs, and exist be sintered in shrink during sintered magnet produce change The situation of shape.As the machining, preferably blasting treatment.Surface roughness (the JISR6001- of Mo plates after sandblasting 1983) it is preferably 5 μm~100 μm, more preferably 7 μm~50 μm, more preferably 10 μm~30 μm in terms of Rmax.Less than 5 μ During m, easily occur the sintering of sintered body and Mo plates, the magnet after sintering deforms.During more than 100 μm, in the process of contraction Middle sintered body is stuck on Mo plates and is deformed.Neodymia etc. is coated with Mo plates, can also prevent the sintered body in sintering With the sintering of Mo plates.
<Other processes>
As needed, the outer peripheral face, inner peripheral surface and end face of the sintered body of gained are processed into required size.This plus In work processing, it can be suitably used that external diameter grinding machine, inside diameter grinder, face lapping mill or molding machine etc. are existing to be set It is standby.As needed, the surface treatment such as the vacuum evaporation of plating, application, aluminium after being processed, chemical conversion treatment.This Outside, preferred pair sintered body implements heat treatment.Heat treatment can be carried out before above-mentioned working process, can also working process it After carry out.
Next, carried out using the analytic method of the present invention, exemplified by specifically having made polar anisotropic toroidal magnet Explanation.
As the precondition of parsing, the external diameter of made polar anisotropic toroidal magnet is 8.25mm, and number of poles is Quadrupole, electromagnetic field generating coil is connected into, be alternately opposite the sense of current of circumferentially adjacent coil, current value is 3kA, density 2.5g/cm3, sintering temperature is 1090 DEG C.In the mould as polar anisotropic magnetic field orientating, internal diameter phase When being changed for defined external diameter, using the analytic method of the present invention, how progress is changed to the internal stress of formed body Parsing.
Figure 18 is the figure for the analysis result for representing internal stress.In figure 18, transverse axis represents the internal diameter [mm] of formed body；It is vertical Axle represents inner circumferential tensile stress [MPa]；● represent：Analysis result in the case where having used mould (reference picture 16), it is described Mould is, the distance between the coil at the immediate position of die cavity of pressing under magnetic field decompressor in pole piece shape, It is more narrower than farthest position；■ is represented：Existing mould is being used (by Figure 16's in the pole piece described in patent document 1 Coil, the mould being converted into after the coil of rectangular shape) in the case of analysis result.In figure 16, in terms of cross section, pole The shape of piece front end is triangle, and multiple electric wires are set in pole piece.
As shown in figure 18, it can be appreciated that interior as the internal diameter of formed body becomes big in the case where having used existing mould Portion's stress is temporarily increased, but internal stress afterwards is reduced.If existing mould is become in pole piece shape furthermore it is also possible to understand It is the distance between coil at the immediate position of die cavity with pressing under magnetic field decompressor in shape, more narrower than farthest position Mould, then internal stress can be made further to reduce.
(embodiment 1)
Based on above-mentioned analysis result, in order to produce external diameter be 8.25mm, internal diameter 4.65mm, length 7.00mm and The quantity of magnetic pole is the polar anisotropic toroidal magnet of quadrupole, and has made the mould for pressing under magnetic field decompressor. Analysis result according to Figure 18, if internal diameter is 4.65mm, the internal stress of sintered body is less than reference set value.
By the shape of die cavity 24 be made external diameter be 10.5mm, internal diameter 5.05mm.Mould 21 is cylindrical shape, in cylindrical shape The inner surface of mould 21 forms multiple grooves, and electromagnetic field generating coil 23 is embedded in each groove.By the electromagnetic field generating coil 23 in each groove It is configured to, electric current is flowed up in the side vertical with the upper surface of mould 21, the electromagnetic field generating coil 23 in each groove is connected Into being alternately opposite the sense of current of circumferentially adjacent coil.In pressing under magnetic field decompressor along the circumferential direction Be configured with four coils, in pole piece between the coil at the immediate position of die cavity of pressing under magnetic field decompressor away from From, it is more narrower than farthest position.
Next, the R-Fe-B alloy (composition as magnetic is prepared：Nd is that 24.0 mass %, Pr are 7.0 matter Amount %, Dy be 1.16 mass %, Nb be 0.15 mass %, Al be 0.1 mass %, Co be 2.0 mass %, Ga be 0.1 mass %, Cu is that 0.1 mass %, B is 0.95 mass %, remaining as Fe).R-Fe-B alloy is made of method for continuous casting sheet band, is passed through Using hydrotreated coarse crushing, using the finely divided of jet pulverizer, average grain diameter has been made as 3 μm with F.S.S.S methods Magnetic.
By batcher, the magnetic produced is filled in the die cavity 24 of pressing under magnetic field decompressor, makes punching 25 decline, and after molding space is formd with punching 25, lower punching 26, mould 21 and magnetic core 22, are being applied with While 850kA/m magnetic field, it is 2.5g/cm to be molded to density3Untill.The formed body after shaping is placed on Mo plates in magnetic field On, it is sintered in argon gas atmosphere and at 1090 DEG C, is cooled to 20 DEG C.After sintering, using whetstone, by polarity respectively to Different in nature toroidal magnet be processed into external diameter be 8.25mm, internal diameter 4.65mm, length 7.00mm.
(embodiment 2)
Based on above-mentioned analysis result, except be 8.25mm to produce external diameter, internal diameter 5.75mm, length 7.00mm Polar anisotropic toroidal magnet and by the shape of die cavity 24 be made external diameter be 10.5mm, internal diameter be outside 6.5mm, using with The identical condition of embodiment 1, has made polar anisotropic toroidal magnet.Analysis result according to Figure 18, if internal diameter For 5.75mm, then the internal stress of sintered body is less than reference set value.
(embodiment 3)
Based on above-mentioned analysis result, in addition to the pole piece shape of mould is rectangular shape, utilization is same as Example 1 Condition, made the polar anisotropic toroidal magnet that external diameter is 8.25mm, internal diameter 4.65mm, length are 7.00mm.
Embodiment 1, embodiment 2, embodiment 3 any one example in, the polarity not cracked can be produced Anisotropy toroidal magnet.Especially, even if the very thin thickness of the low magnet of the internal stress of sintered body, will not also produce and split Line.This result is identical with the analysis result of the present invention.
In addition, for each polar anisotropic toroidal magnet for being made in embodiment 1, embodiment 2, embodiment 3 Surface magnetic flux density, surface magnetic flux density waveform compare.Surface magnetic flux density is measured with gaussmeter, utilizes analysis Device is calculated the data determined by gaussmeter, and has obtained surface magnetic flux density waveform.Figure 19 and Figure 20 is to represent The figure of the surface magnetic flux density waveform of polar anisotropic toroidal magnet, transverse axis represent angle [deg.], and the longitudinal axis represents magnet Surface magnetic flux density (T).In Figure 19, the result of calculation (solid line) of embodiment 1 and the result of calculation (void of embodiment 3 are illustrated Line), in fig. 20, illustrate the result of calculation (solid line) of embodiment 2 and the result of calculation (dotted line) of embodiment 3.
(the ginseng when surface magnetic flux density and surface magnetic flux density waveform to embodiment 1 and embodiment 3 compare According to Figure 19), the peak value Bg of embodiment 1 is 13% and very high.In addition, when comparing higher hamonic wave distortion rate (THD), embodiment 3 be 8.3%, on the other hand, embodiment 1 is 1.0%, and well.
In addition, compared in surface magnetic flux density and surface magnetic flux density waveform to embodiment 2 and embodiment 3 When (reference picture 20), peak value Bg is equal.But because the sectional area of embodiment 2 is than embodiment 3 few 25%, so, if relatively more each The peak value Bg of sectional area, then embodiment 2 high 24%.In addition, when comparing higher hamonic wave distortion rate (THD), embodiment 3 is 8.3%, on the other hand, embodiment 2 is 1.0%, and well.
The reasons why embodiment 1 and embodiment 2 low relative to the higher hamonic wave distortion rate of embodiment 3, is, due to by making The distance between coil at the immediate position of die cavity with pressing under magnetic field decompressor in pole piece shape, than farthest The narrower mould in position, so as to produce the alignment magnetic field close to sine wave.To obtain the surface magnetic flux density close to sine wave Distribution, and need access to the alignment magnetic field of sine wave.Most being connect with the die cavity of decompressor with pressing under magnetic field in pole piece shape The distance between near coil at position, the mould more narrower than farthest position, being capable of taking magnetic when being molded in magnetic field Sine wave is kept into magnetic field.In addition, the conductor area by increasing coil, can also make magnetomotive force become big.
In addition, in the above-described embodiment, anisotropy is burnt by taking R-Fe-B polar anisotropic toroidal magnet as an example The analytic method and manufacture method for tying magnet are illustrated, but on having used the anisotropy of ferrite type material to sinter Magnet, it can also apply to the present invention.
In addition, in the above-described embodiment, polar anisotropic toroidal magnet is illustrated, but on through oversintering The radial anisotropic toroidal magnet that process is produced, it can similarly be applied to the present invention.In addition, it is not limited in annular magnetic Body, on block-shaped or bowed shape magnet, it can similarly be applied to the present invention.
In addition, in the above-described embodiment, the polar anisotropic ring using outside diameter as polar anisotropic magnetic field orientating It is illustrated exemplified by shape magnet, but the polar anisotropic annular magnetic on internal side diameter for polar anisotropic magnetic field orientating Body, it can similarly be applied to the present invention.
Disclosed embodiment, be considered to be exemplary rather than in all aspects it is restricted.The model of the present invention Enclose and represented by claims rather than represented by described above, and mean to include the implication equal with claims with And being had altered in scope.
Description of reference numerals
1 analysis unit
2 storage parts
3 interim storage portions
4 input units
5 display parts
6 output sections
11 polar anisotropic toroidal magnets
12 N poles
13 S poles

Claims (12)

  1. A kind of 1. analytic method of sintered anisotropic magnet, it is characterised in that
    The analytic method is the method parsed to sintered anisotropic magnet, the sintered anisotropic magnet be by While the magnetic is carried out magnetic field orientating shaping so as to obtain the process of formed body and the formed body to producing be sintered from And obtain the sintering circuit of sintered body and produce,
    In the sintering circuit, it is divided into the unstressed process that does not apply stress and applies the stress path of stress the two ranks Duan Jinhang is parsed.
  2. 2. the analytic method of sintered anisotropic magnet according to claim 1, it is characterised in that
    In the parsing of the unstressed process, the shrinkage factor of easy axis and the shrinkage factor in hard axis direction are used； In the parsing of the stress path, system is expanded using the linear expansion coefficient of easy axis and the line in hard axis direction Number.
  3. 3. the analytic method of sintered anisotropic magnet according to claim 2, it is characterised in that
    The shrinkage factor and linear expansion coefficient is set to be changed according to the alignment magnetic field of the formed body.
  4. 4. the analytic method of sintered anisotropic magnet according to any one of claim 1 to 3, it is characterised in that
    Parsing in the sintering circuit includes：In the process being sintered to formed body, to applying during unstressed Shape before the stress path of stress is parsed, according to the shape before the stress path after the parsing in stress path Shape parses the shape and stress at the end of sintering.
  5. 5. the analytic method of sintered anisotropic magnet according to any one of claim 1 to 4, it is characterised in that
    According to the alignment magnetic field of the formed body, the magnetic characteristic distribution of the sintered body is obtained.
  6. 6. the analytic method of sintered anisotropic magnet according to any one of claim 1 to 5, it is characterised in that
    After the sintering circuit, the parsing knot based on the deflection after from the shape distortion of formed body into the shape of sintered body Fruit, make alignment magnetic field Vector Rotation, and obtain the distribution of the alignment magnetic field vector of the sintered body.
  7. 7. the analytic method of sintered anisotropic magnet according to any one of claim 1 to 6, it is characterised in that
    Magnetic field parsing and/or demagnetization parsing are carried out to the sintered anisotropic magnet.
  8. A kind of 8. analytic method of sintered anisotropic magnet, it is characterised in that
    The analytic method is the method parsed to sintered anisotropic magnet, the sintered anisotropic magnet be by While the magnetic is carried out magnetic field orientating shaping so as to obtain the process of formed body and the formed body to producing be sintered from And obtain the sintering circuit of sintered body and produce, the analytic method has following steps：
    Make alignment magnetic field that various change occur so as to produce sintered body in advance, size and thermo-mechanical property be measured, Shrinkage factor and linear expansion coefficient are determined respectively in easy axis and hard axis direction, and solution is made according to measurement result Analysis data storehouse and the step of stored in advance；
    The step of being parsed to the 3 D tropism Distribution of Magnetic Field of the formed body in molding procedure；
    The step of extracting two-dimensional orientation Distribution of Magnetic Field out from the 3 D tropism Distribution of Magnetic Field；
    In sintering circuit do not apply stress it is unstressed during, occur using according to the two-dimensional orientation Distribution of Magnetic Field The shrinkage factor of the easy axis of change and the shrinkage factor in hard axis direction, are parsed, and obtain and applying to deflection The step of adding the shape before the stress path of stress；
    In the stress path of application stress in sintering circuit, using the shape before the stress path as original shape, Linear expansion coefficient and hard axis side using the easy axis to be changed according to the two-dimensional orientation Distribution of Magnetic Field To linear expansion coefficient, the step of being parsed to deflection and stress, and obtain shape and stress distribution；
    After sintering circuit, based on the analysis result of the deflection after from the shape distortion of formed body into the shape of sintered body, make Alignment magnetic field Vector Rotation, and obtain sintered body alignment magnetic field vector distribution the step of；And
    From the distribution of the magnetic characteristic of sintered body, the step of mapping out the magnetic characteristic distribution of the shape after being processed to sintered body.
  9. 9. the analytic method of sintered anisotropic magnet according to claim 8, it is characterised in that
    Also there are following steps：The step of magnetic field parsing is carried out to the sintered anisotropic magnet and/or carry out demagnetization parsing The step of.
  10. 10. a kind of manufacture method of sintered anisotropic magnet, it is characterised in that there is following process：
    Preparation includes the process with the mould of mold cavity shapes and the pressing under magnetic field decompressor of electromagnetic field generating coil, described Mold cavity shapes are less than according to the analysis result of sintered anisotropic magnet as follows, with the internal stress of sintered body Reference set value is what condition was designed, and the step is as follows：Make alignment magnetic field that various change occur so as to produce in advance Sintered body, shrinkage factor and linear expansion coefficient are determined respectively in easy axis and hard axis direction, tied according to measure The step of fruit is made parsing with database and stored in advance；To the 3 D tropism Distribution of Magnetic Field of the formed body in molding procedure The step of being parsed；In sintering circuit do not apply stress it is unstressed during, using according to alignment magnetic field distribution and The shrinkage factor of the easy axis to change and the shrinkage factor in hard axis direction, are parsed, and obtain to deflection Apply stress stress path before shape the step of；In the stress path of application stress in sintering circuit, by institute The shape before stress path is stated as original shape, uses the easy axis for being distributed and changing according to alignment magnetic field Linear expansion coefficient and hard axis direction linear expansion coefficient, deflection and stress are parsed, and obtain shape with And the step of stress distribution；After sintering circuit, based on the deflection after from the shape distortion of formed body into the shape of sintered body Analysis result, make alignment magnetic field Vector Rotation, and obtain sintered body alignment magnetic field vector distribution the step of；And from sintering Body magnetic characteristic distribution in, map out the shape after being processed to sintered body magnetic characteristic distribution the step of；
    Prepare the process of magnet alloy powder；
    Using the pressing under magnetic field decompressor, the process being molded in magnetic field to the magnet alloy powder；And
    Process to being sintered in the magnetic field by being molded the formed body produced.
  11. 11. the manufacture method of sintered anisotropic magnet according to claim 10, it is characterised in that
    In the process for preparing the pressing under magnetic field decompressor, the electromagnetic field generating coil is pole piece shape, with the magnetic It is the distance between coil at the immediate position of die cavity of shaping decompressor, more narrower than farthest position.
  12. 12. the manufacture method of the sintered anisotropic magnet according to claim 10 or 11, it is characterised in that
    In the process for preparing the pressing under magnetic field decompressor, the electromagnetic field generating coil is more than four, and is arranged to The adjacent electromagnetic field generating coil is extremely different on the die cavity side of the pressing under magnetic field decompressor.
CN201680027254.XA 2015-12-16 2016-12-16 The manufacture method of the analytic method of sintered anisotropic magnet and the sintered anisotropic magnet of use this method Pending CN107615418A (en)

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