JP2003164082A - Ferrite magnet, rotating machine and production method of ferrite magnet - Google Patents
Ferrite magnet, rotating machine and production method of ferrite magnetInfo
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- JP2003164082A JP2003164082A JP2001356811A JP2001356811A JP2003164082A JP 2003164082 A JP2003164082 A JP 2003164082A JP 2001356811 A JP2001356811 A JP 2001356811A JP 2001356811 A JP2001356811 A JP 2001356811A JP 2003164082 A JP2003164082 A JP 2003164082A
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- Prior art keywords
- peripheral surface
- ferrite magnet
- outer peripheral
- ferrite
- inner peripheral
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、凸曲面である外周
面及び内周面を備える棒状フェライト磁石に係わり、特
に高性能の回転機に設けるフェライト磁石に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rod-shaped ferrite magnet having an outer peripheral surface and an inner peripheral surface which are convex curved surfaces, and more particularly to a ferrite magnet provided in a high performance rotating machine.
【０００２】[0002]
【従来の技術】電動機、発動機などの磁気回路には、ハ
ードフェライト磁石が用いられている。この種の磁石
は、一般的に円筒状あるいはそれを複数に分割したセグ
メント形状を有している。セグメント磁石を用いた回転
機においては、回転力を生み出す磁束の分布に起因する
磁気騒音を極力低くすることが望まれている。ここで、
磁気騒音とは電動機の磁気回路における空隙の磁束密度
の波形が正弦波から歪んで凹凸を呈することに起因す
る。永久磁石界磁方式の回転機効率を左右する空隙磁束
密度波形、有効磁束量は界磁磁石の形状および磁気異方
性の付与パターンにより大きく変化する。すなわち、固
定子と回転子との間に働く磁気吸引力に基づいたトルク
の回転子角に対する変化、いわゆるコギングというトル
ク変動によって、回転むらや振動が生じ、騒音を発生す
る。2. Description of the Related Art Hard ferrite magnets are used in magnetic circuits of electric motors and motors. This type of magnet generally has a cylindrical shape or a segment shape obtained by dividing the magnet into a plurality of pieces. In a rotating machine using segment magnets, it is desired to minimize magnetic noise caused by the distribution of magnetic flux that produces a rotating force. here,
The magnetic noise is caused by the fact that the waveform of the magnetic flux density of the air gap in the magnetic circuit of the electric motor is distorted from a sine wave to present irregularities. The air gap magnetic flux density waveform and the effective magnetic flux amount that influence the efficiency of the permanent magnet field type rotating machine greatly vary depending on the shape of the field magnet and the pattern of imparting magnetic anisotropy. That is, due to a change in torque with respect to the rotor angle based on the magnetic attraction force acting between the stator and the rotor, that is, torque fluctuation called so-called cogging, uneven rotation and vibration occur and noise is generated.
【０００３】特に、エアコン用の圧縮機には静粛性が重
視されている。従来、圧縮機のモーターには、ステータ
ーを巻線とヨークで構成し、断面形状が瓦状の板状磁石
をローターに固定した永久磁石型モーターが用いられて
いる。In particular, silence is emphasized in compressors for air conditioners. Conventionally, as a motor of a compressor, a permanent magnet type motor in which a stator is composed of a winding wire and a yoke, and a plate magnet having a tile-shaped cross section is fixed to a rotor is used.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、従来の
フェライト磁石について、トルクを大きくするために、
ステーターに対向する側の面を強磁性面にすべく磁化を
配向させると、ステーターに印加する磁束密度の波形が
正弦波状にならず、大きく歪んでしまい、コギングトル
クを発生させる。そこで、本発明の目的はモーターのコ
ギングトルクを抑制することができるフェライト磁石を
提供するものである。However, in order to increase the torque of the conventional ferrite magnet,
When the magnetization is oriented so that the surface on the side facing the stator is a ferromagnetic surface, the waveform of the magnetic flux density applied to the stator does not become sinusoidal, but is greatly distorted, and cogging torque is generated. Then, the objective of this invention is providing the ferrite magnet which can suppress the cogging torque of a motor.
【０００５】[0005]
【課題を解決するための手段】本発明のフェライト磁石
は、棒状のフェライト磁石であって、軸方向に垂直な断
面形状が紡錘形状であり、前記紡錘形状は外周面と内周
面で囲われており、前記内周面の曲率半径が１０ｍｍ以
上且つ３０ｍｍ以下であることを特徴とする。The ferrite magnet of the present invention is a rod-shaped ferrite magnet having a spindle shape in a cross section perpendicular to the axial direction, and the spindle shape is surrounded by an outer peripheral surface and an inner peripheral surface. The radius of curvature of the inner peripheral surface is 10 mm or more and 30 mm or less.
【０００６】ここで、紡錘形状とは、円弧状の外周と内
周で囲われた形状、紡錘型、目玉形状、凸レンズ形状、
それらのアウトラインの一部を短い直線に置換した近似
形状などを含む。外周面もしくは内周面の断面が、放物
線状の線や直線を含んだ線である場合には、それらの形
状がほぼ重なる円弧をもって曲率半径を算出する。円弧
を重ねてみる方法が難しい場合には、外周もしくは内周
に対して、内接する円弧と外接する円弧を描き、両方の
円弧の曲率半径の平均値を本発明に係る曲率半径とす
る。内周とは、このフェライト磁石を回転機のローター
に備え付けたときに、軸中心を向く面に相当する。ま
た、棒状とは、円柱、準円柱あるいは楕円柱などについ
て、その一部を軸方向に沿って取り除いた形状を含む。
これらの断面形状は、中央部の肉厚（＝最大厚さｔ）を
大きくし、端部の肉厚を薄くするとともに、内周の曲率
半径を所定の範囲に規定することにより、磁束密度分布
の歪みを抑制することができる。Here, the spindle shape means a shape surrounded by an arc-shaped outer circumference and an inner circumference, a spindle shape, an eyeball shape, a convex lens shape,
It includes an approximate shape in which a part of the outline is replaced with a short straight line. When the cross section of the outer peripheral surface or the inner peripheral surface is a parabolic line or a line including a straight line, the radius of curvature is calculated with an arc that substantially overlaps these shapes. When it is difficult to overlap the arcs, an inscribed arc and an circumscribed arc are drawn on the outer circumference or the inner circumference, and the average value of the curvature radii of both arcs is set as the curvature radius according to the present invention. The inner circumference corresponds to the surface facing the center of the axis when the ferrite magnet is mounted on the rotor of the rotating machine. Further, the rod-like shape includes a cylindrical shape, a quasi-cylindrical shape, an elliptic cylinder, and the like, a part of which is removed along the axial direction.
These cross-sectional shapes are such that the thickness of the central portion (= maximum thickness t) is increased, the thickness of the end portions is reduced, and the radius of curvature of the inner circumference is regulated within a predetermined range, whereby the magnetic flux density distribution is Distortion can be suppressed.
【０００７】本発明の他のフェライト磁石は、回転機の
ローターに設ける棒状のフェライト磁石であって、軸方
向の断面が曲率の異なる二つの円弧で囲われた形状をし
ており、一方の円弧が外周面であり、他方の円弧が内周
面であり、前記内周面の曲率半径が前記外周面の曲率半
径より小さく、且つ内周面の曲率半径が１０ｍｍ以上且
つ３０ｍｍ以下であることを特徴とする。Another ferrite magnet of the present invention is a rod-shaped ferrite magnet provided in a rotor of a rotary machine, and has a cross section in the axial direction surrounded by two arcs having different curvatures, and one arc Is an outer peripheral surface, the other arc is an inner peripheral surface, the radius of curvature of the inner peripheral surface is smaller than the radius of curvature of the outer peripheral surface, and the radius of curvature of the inner peripheral surface is 10 mm or more and 30 mm or less. Characterize.
【０００８】外周面と内周面は、円柱面（Cylindrical
surface）状の凸面である。内周面と外周面で棒状の
フェライト磁石の主要な面を構成する。更に内周面と外
周面の境界に幅の狭い平坦面を設けてもよい。The outer peripheral surface and the inner peripheral surface are cylindrical surfaces (Cylindrical surfaces).
surface) -like convex surface. The inner peripheral surface and the outer peripheral surface form the main surface of the rod-shaped ferrite magnet. Further, a narrow flat surface may be provided at the boundary between the inner peripheral surface and the outer peripheral surface.
【０００９】上記本発明に係るのフェライト磁石のいず
れかで、軸方向の長さＬと、外周面と内周面間の最大厚
さｔの関係は、０．０７≦ｔ／Ｌ≦０．３の関係を満た
すことが望ましい。棒状フェライト磁石の軸方向の端部
では、ステーターに向かうべき磁力線の向きがステータ
ーからずれてしまう。このズレにより、ステーターがロ
ーターを回転させるエネルギー効率（モーターの効率）
が低下する。本発明の棒状のフェライト磁石について、
ｔ／Ｌを上記範囲に規定し、外周面側が強磁性面となる
よに着磁すると、フェライト磁石がステーターに印加す
る磁束密度を、フェライト磁石の軸方向について均一化
することができ、モーターの効率向上に寄与する。In any of the ferrite magnets according to the present invention, the relationship between the axial length L and the maximum thickness t between the outer peripheral surface and the inner peripheral surface is 0.07≤t / L≤0. It is desirable to satisfy the relationship of 3. At the end of the rod-shaped ferrite magnet in the axial direction, the direction of the magnetic force lines that should be directed to the stator is deviated from the stator. Due to this deviation, the energy efficiency that the stator rotates the rotor (motor efficiency)
Is reduced. Regarding the rod-shaped ferrite magnet of the present invention,
By defining t / L in the above range and magnetizing so that the outer peripheral surface side becomes a ferromagnetic surface, the magnetic flux density applied to the stator by the ferrite magnet can be made uniform in the axial direction of the ferrite magnet. Contributes to improved efficiency.
【００１０】上記本発明に係るフェライト磁石のいずれ
かで、軸方向の端に端面を備え、前記端面の周囲の少な
くとも一部に面取り加工または丸め加工を施されている
ことを特徴とする。面取りは、外周面取り、内周面取
り、周縁のＣ面取り等とすることができる。端面と側面
（外周面や内周面）間の角を丸めてＲを付けたり、ある
いは面取りを施すことにより、棒状のフェライト磁石か
らステーターに印加する磁力線の平行性を磁気回路的に
高め、モーターの効率を向上する効果が更に強められ
る。すなわち、ローター表面の磁界をローターの回転方
向に沿って測定したところ、最大値Ｂｏは１ｋＧより大
となる。この磁界分布はやや膨らんだ正弦波状になる。
横軸を距離にとり、縦軸をローター表面の磁界でプロッ
トすると、半値幅が全幅の７０％より大である良好な波
形を得ることができる。また、ローターのスロットにフ
ェライト磁石を挿入する際に、端面のカケを抑制するた
め、回転機の歩留まり向上にも寄与する。One of the ferrite magnets according to the present invention is characterized in that an end face is provided at an end in the axial direction, and at least a part of the periphery of the end face is chamfered or rounded. The chamfer may be an outer peripheral chamfer, an inner peripheral chamfer, a peripheral C chamfer, or the like. By rounding the corner between the end surface and the side surface (outer peripheral surface or inner peripheral surface) and attaching R or chamfering, the parallelism of the magnetic force lines applied from the rod-shaped ferrite magnet to the stator is enhanced by a magnetic circuit, The effect of improving the efficiency of is further strengthened. That is, when the magnetic field on the rotor surface was measured along the rotation direction of the rotor, the maximum value Bo was larger than 1 kG. This magnetic field distribution has a slightly swollen sinusoidal shape.
By plotting the horizontal axis as the distance and the vertical axis as the magnetic field on the rotor surface, it is possible to obtain a good waveform having a full width at half maximum of more than 70% of the full width. Further, when the ferrite magnet is inserted into the slot of the rotor, chipping of the end face is suppressed, which contributes to the improvement of the yield of the rotating machine.
【００１１】上記本発明に係るフェライト磁石のいずれ
かにおいて、外周面が強磁性面である。内周面側に比べ
て外周面側で磁束密度が高くなるように磁化を配向させ
る。ここで、外周面とは、このフェライト磁石を回転機
のローターに設けたときに、ローターの外周側に対応す
る面をいう。同様に、内周面とはローターの軸側に対応
する面をいう。より具体的には図１で説明する。In any of the ferrite magnets according to the present invention, the outer peripheral surface is a ferromagnetic surface. The magnetization is oriented so that the magnetic flux density is higher on the outer peripheral surface side than on the inner peripheral surface side. Here, the outer peripheral surface means a surface corresponding to the outer peripheral side of the rotor when the ferrite magnet is provided on the rotor of the rotating machine. Similarly, the inner peripheral surface means a surface corresponding to the shaft side of the rotor. A more specific description will be given with reference to FIG.
【００１２】また、内周面の中央に、更に平坦面を設け
る構成とすることができる。この平坦面の長手方向は軸
方向に平行とする。この平坦面を下にしてフェライトを
冶具上に置いて固定すると、外周面を精度良く加工する
ことができる。Further, a flat surface may be provided in the center of the inner peripheral surface. The longitudinal direction of this flat surface is parallel to the axial direction. When the ferrite is placed on a jig and fixed with the flat surface facing downward, the outer peripheral surface can be processed with high accuracy.
【００１３】本発明に係るフェライト磁石を構成する材
料として、正弦波状の強い磁界をステーターに印加する
ためには、下記一般式：
(Ａ１−ｘＲｘ)Ｏ・ｎ［(Ｆｅ１−ｙＭｙ)２Ｏ３］（原
子比率）
(ただし、ＡはＳｒおよび／またはＢａであり、ＲはＬ
ａ，Ｎｄ，ＰｒおよびＣｅのうちの少なくとも１種であ
り、Ｒに占めるＬａの比率が30原子％以上であり、Ｍは
ＣｏまたはＣｏおよびＺｎであり、ｘ、ｙおよびｎはそ
れぞれ下記条件：
0.01≦ｘ≦0.4，
0.005≦ｙ≦0.04，および
５≦ｎ≦6.2
を満たす数字である。）により表される基本組成を有
し、実質的にマグネトプランバイト型結晶構造を有する
フェライト磁石を用いることが望ましい。特に、上記組
成式でＲ＝Ｌａであり、残留磁束密度Ｂｒ≧４１００Ｇ
であり、保磁力ｉＨｃ≧４０００Ｏｅであり、角型比
（Ｂｒ／ｉＨｃ）≧９２．３％であるＬａＣｏ添加Ｓｒ
系フェライト磁石材料を用いると良い。As a material constituting the ferrite magnet according to the present invention, in order to apply a strong sinusoidal magnetic field to the stator, the following general formula: (A 1-x R x ) O · n [(Fe 1-y M y) 2 O 3] (atomic ratio) (wherein, a is Sr and / or Ba, R is L
at least one of a, Nd, Pr and Ce, the ratio of La in R is 30 atomic% or more, M is Co or Co and Zn, and x, y and n are each under the following conditions: It is a number that satisfies 0.01 ≦ x ≦ 0.4, 0.005 ≦ y ≦ 0.04, and 5 ≦ n ≦ 6.2. It is desirable to use a ferrite magnet having a basic composition represented by (1) and having a substantially magnetoplumbite type crystal structure. In particular, in the above composition formula, R = La and the residual magnetic flux density Br ≧ 4100G
And coercive force iHc ≧ 4000 Oe and squareness ratio (Br / iHc) ≧ 92.3% LaCo-added Sr
It is preferable to use a ferrite ferrite material.
【００１４】上記ＲにはＬａ，Ｎｄ，ＰｒおよびＣｅの
うちの少なくとも１種以外の不可避の希土類元素（Ｙを
含む）を含むことが許容される。実用に耐える磁気特性
を具備するためにｘ，ｙおよびｎをそれぞれ0.01≦ｘ≦
0.4，0.005≦ｙ≦0.04および5≦ｎ≦6.2 にするととも
にＲに占めるＬａの比率を30原子％以上にするのが好ま
しく、Ｒに占めるＬａの比率を50原子％以上にするのが
より好ましい。モル比ｎは５〜6.2とする必要があり、
5.5〜6.1がより好ましく、5.7〜6.0が特に好ましい。ｎ
が6.2超ではマグネトプランバイト相以外の異相(α−Fe
2O3等)の存在により固有保磁力ｉＨｃが大きく低下し、
ｎが５未満では残留磁束密度Ｂｒが大きく低下する。ｘ
は0.01〜0.4が好ましく、0.1〜0.3がより好ましく、0.1
5〜0.25が特に好ましい。ｘが0.01未満では添加効果を
得られず、0.4超では逆に磁気特性が低下する。It is allowed that R contains an unavoidable rare earth element (including Y) other than at least one of La, Nd, Pr and Ce. X, y, and n are each 0.01 ≦ x ≦ in order to have magnetic properties that can be used practically.
It is preferable that 0.4, 0.005 ≦ y ≦ 0.04 and 5 ≦ n ≦ 6.2, and the ratio of La in R is 30 atomic% or more, and the ratio of La in R is 50 atomic% or more. . The molar ratio n must be 5 to 6.2,
5.5-6.1 are more preferable, and 5.7-6.0 are particularly preferable. n
Is more than 6.2, a different phase other than the magnetoplumbite phase (α-Fe
(2 O 3 etc.) greatly reduces the intrinsic coercive force iHc,
When n is less than 5, the residual magnetic flux density Br is significantly reduced. x
Is preferably 0.01 to 0.4, more preferably 0.1 to 0.3, 0.1
5 to 0.25 is particularly preferable. If x is less than 0.01, the effect of addition cannot be obtained, and if it exceeds 0.4, the magnetic properties are deteriorated.
【００１５】ｙとｘとの間には電荷補償のために理想的
には、ｙ＝ｘ/(2.0ｎ)の関係が成立する必要があるが、
ｙがｘ/（2.6ｎ）以上、ｘ／（1.6ｎ）以下であれば高
いBrおよび高い減磁曲線の角形比を具備するフェライト
焼結磁石を作製可能である。なお、ｙがｘ/（2.0ｎ）か
らずれた場合、Ｆｅ２＋を含む場合があるが、何ら支障
はない。典型的な例では、ｙの好ましい範囲は0.04以下
であり、特に0.005〜0.03である。Ideally, the relationship of y = x / (2.0n) should be established between y and x for charge compensation.
If y is x / (2.6n) or more and x / (1.6n) or less, a ferrite sintered magnet having a high Br and a high demagnetization curve squareness ratio can be produced. If y deviates from x / (2.0n), Fe 2+ may be contained, but there is no problem. In a typical example, the preferable range of y is 0.04 or less, and particularly 0.005 to 0.03.
【００１６】緻密なフェライト焼結磁石を得るために焼
結性を制御する添加物としてSiO2およびCaOを所定量含
有することが実用上極めて重要である。SiO2は焼結時の
結晶粒成長を抑制する添加物であり、フェライト焼結磁
石の総重量を100重量％としてSiO2含有量を0.05〜0.55
重量％とするのが好ましく、0.25〜0.50重量％とするの
がより好ましい。SiO2含有量が0.05重量％未満では焼結
時に結晶粒成長が過度に進行し保磁力が大きく低下し、
0.55重量％超では結晶粒成長が過度に抑制され結晶粒成
長による配向度の改善が不十分となりBrが大きく低下す
る。CaOは結晶粒成長を促進する添加物であり、フェラ
イト焼結磁石の総重量を100重量％としてCaO含有量を0.
35〜1.5重量％にするのが好ましく、0.4〜1.0重量％に
するのがより好ましく、0.5〜0.9重量％にするのが特に
好ましい。CaO含有量が1.5重量％超では焼結時に結晶粒
成長が過度に進行し、保磁力が大きく低下し、0.35重量
％未満では結晶粒成長が過度に抑制され、結晶粒成長に
よる配向度の改善が不十分となりBrが大きく低下する。In order to obtain a dense ferrite sintered magnet, it is extremely important for practical use to contain a predetermined amount of SiO 2 and CaO as additives for controlling the sinterability. SiO 2 is an additive that suppresses crystal grain growth during sintering, and the total weight of the ferrite sintered magnet is 100% by weight, and the SiO 2 content is 0.05 to 0.55.
It is preferably in the range of 0.25 to 0.50% by weight, more preferably in the range of 0.25 to 0.50% by weight. If the SiO 2 content is less than 0.05% by weight, the crystal grain growth excessively progresses during sintering and the coercive force greatly decreases,
If it exceeds 0.55% by weight, the crystal grain growth is excessively suppressed and the improvement of the orientation degree due to the crystal grain growth becomes insufficient, resulting in a large decrease in Br. CaO is an additive that promotes crystal grain growth, and the total weight of the sintered ferrite magnet is 100% by weight, and the CaO content is 0.
It is preferably 35 to 1.5% by weight, more preferably 0.4 to 1.0% by weight, and particularly preferably 0.5 to 0.9% by weight. If the CaO content exceeds 1.5% by weight, the crystal grain growth excessively progresses during sintering and the coercive force greatly decreases, and if it is less than 0.35% by weight, the crystal grain growth is excessively suppressed, and the degree of orientation is improved by the crystal grain growth. Becomes insufficient and Br decreases significantly.
【００１７】また5.7≦ｎ≦6.2，0.2≦ｘ≦0.3および1.
0＜ｘ/2ny≦1.3 というＲ過剰の基本成分組成を選択
し、かつCaO含有量が0.5〜0.9重量％及びSiO2含有量が
0.25〜0.55重量％のときに従来に比べて減磁曲線の角形
比を顕著に高めることができるので最も好ましい。5.7 ≦ n ≦ 6.2, 0.2 ≦ x ≦ 0.3 and 1.
0 <x / 2ny ≦ 1.3 was selected as the basic component composition in excess of R, and the CaO content was 0.5 to 0.9% by weight and the SiO 2 content was
The range of 0.25 to 0.55% by weight is most preferable because the squareness ratio of the demagnetization curve can be remarkably increased as compared with the conventional case.
【００１８】本発明のフェライト焼結磁石が前記基本組
成を有し、Ｍ元素がＣｏおよびＺｎからなる場合、室温
のiHcを279kA/m（3.5kOe）以上とし耐熱性を具備するた
めに、［Ｃｏ/（Ｃｏ＋Ｚｎ）］比率を50〜90原子％に
するのが好ましく、70〜90原子％にするのがより好まし
い。Ｃｏ含有量が90原子％超ではＺｎの含有によるBrの
向上効果が事実上得られず、Ｃｏ含有量が50原子％未満
では室温のiHcで279kA/m（3.5kOe）以上を得られなくな
る。When the ferrite sintered magnet of the present invention has the above-mentioned basic composition and the M element is composed of Co and Zn, iHc at room temperature is 279 kA / m (3.5 kOe) or more so as to have heat resistance, The Co / (Co + Zn)] ratio is preferably 50 to 90 atom%, and more preferably 70 to 90 atom%. If the Co content exceeds 90 atomic%, the effect of improving Br by the inclusion of Zn is practically not obtained, and if the Co content is less than 50 atomic%, iHc at room temperature cannot attain 279 kA / m (3.5 kOe) or more.
【００１９】本発明のフェライト磁石が実質的にマグネ
トプランバイト型結晶構造を有するフェライト焼結磁石
からなる場合、磁気特性発現相がマグネトプランバイト
相のみの場合に限定されず、主相がマグネトプランバイ
ト相である場合を包含する。When the ferrite magnet of the present invention is substantially composed of a ferrite sintered magnet having a magnetoplumbite type crystal structure, it is not limited to the case where the phase exhibiting magnetic characteristics is only the magnetoplumbite phase, and the main phase is magnetoplumbite. Including the case of bite phase.
【００２０】本発明のフェライト磁石の製造方法は、金
型を用い、上パンチと下パンチで材料をプレスする成形
装置でフェライトの成形体を作製する成形工程と、前記
成形体を焼成して焼結体を得る焼成工程と、前記焼結体
を研削加工して棒状フェライト磁石を作製する加工工程
を備え、成形工程にて下パンチで成形した側を凸面の外
周面とし、軸方向に垂直な断面でみた形状が円弧状の外
周と内周に囲われた形状であり、外周の凸方向と内周の
凸方向は逆向きであるフェライト磁石を得ることを特徴
とする。さらに、この製造方法において、前記下パンチ
の側から磁界を印加することにより、外周面側の磁化配
向を密にして外周面を強磁性面にすることができる。The method for producing a ferrite magnet according to the present invention comprises a forming step of producing a ferrite molded body by a molding apparatus in which a die is used to press a material with an upper punch and a lower punch, and the molded body is fired and baked. It comprises a firing step of obtaining a bonded body and a processing step of grinding the sintered body to produce a rod-shaped ferrite magnet. The side formed by the lower punch in the forming step is the outer peripheral surface of the convex surface, and is perpendicular to the axial direction. The ferrite magnet is characterized in that the shape seen in cross section is a shape surrounded by an arc-shaped outer circumference and an inner circumference, and the outer peripheral convex direction and the inner peripheral convex direction are opposite. Further, in this manufacturing method, by applying a magnetic field from the lower punch side, the magnetization orientation on the outer peripheral surface side can be made dense and the outer peripheral surface can be made a ferromagnetic surface.
【００２１】ここで、成形装置を地面に設置したとき
に、地面に近い側の金型を下パンチと称し、遠い側の金
型を上パンチと称する。上パンチおよび下パンチはとも
にフェライトをプレスする側の面を凹んだ形状とする。
成形方法は、湿式成形もしくは乾式成形のいずれでも可
能である。研削加工は、研削／研磨のいずれも可能であ
るが、回転砥石を用いた研削を選択することが望まし
い。すなわち、この製法では、アークセグメントあるい
はブロック形状の焼結磁石から断面が二つの円弧で囲わ
れた形状となるように研削もしくは切り出す製法に相当
する。Here, when the molding apparatus is installed on the ground, the metal mold on the side closer to the ground is called a lower punch, and the metal mold on the far side is called an upper punch. Both the upper punch and the lower punch have a recessed surface on the side where ferrite is pressed.
The molding method may be either wet molding or dry molding. Both grinding and polishing can be performed, but it is desirable to select grinding using a rotary grindstone. That is, this manufacturing method corresponds to a manufacturing method in which an arc segment or a block-shaped sintered magnet is ground or cut so as to have a cross section surrounded by two arcs.
【００２２】内周側（内周面側）の曲率半径を小さくす
ると共に外周面側を強磁性面とするフェライト磁石の外
形を一括で成形・着磁しようとすると、棒状のフェライ
ト磁石の磁束密度分布に歪みが生じ易い。そこで、成形
体を大きくして研削加工で削る量を多くすることで、こ
の歪みを防止する、まず、成形工程では、上下のパンチ
における凹面の凹み具合を、棒状フェライト磁石の外周
面の曲率半径程度にし、棒状というよりむしろ板状の成
形体を形成する。この大きめの成形体の下パンチ成形側
を削って凸曲面状の外周面を形成する。When it is attempted to form and magnetize the outer shape of a ferrite magnet having a ferromagnetic surface on the outer peripheral surface side while reducing the radius of curvature on the inner peripheral side (inner peripheral surface side), the magnetic flux density of the rod-shaped ferrite magnet is reduced. Distribution tends to be distorted. Therefore, this distortion is prevented by increasing the size of the compact and increasing the amount of grinding to cut it.First, in the forming process, the degree of depression of the concave surface of the upper and lower punches is determined by the radius of curvature of the outer peripheral surface of the rod-shaped ferrite magnet. To a degree, a plate-shaped molded body is formed rather than a rod-shaped molded body. The outer peripheral surface of the convex curved surface is formed by scraping the lower punch forming side of this larger formed body.
【００２３】本発明に係る他のフェライト磁石の製造方
法は、金型を用い、パンチで材料をプレスする成形装置
でフェライトの成形体を作製する工程と、前記成形体を
焼成して焼結体を得る工程と、前記焼結体を研削加工し
て棒状フェライト磁石を作製する加工工程を備え、前記
成形工程において、棒状フェライト磁石の軸方向の端に
おける面取り加工の少なくとも一部を行うことにより、
軸方向に垂直な断面でみた形状が円弧状の外周と内周に
囲われた形状であり、外周の凸方向と内周の凸方向は逆
向きであるフェライト磁石を得ることを特徴とする。Another method for producing a ferrite magnet according to the present invention is a step of producing a ferrite molded body using a molding apparatus in which a die is used to press a material, and a sintered body obtained by firing the molded body. And a processing step of producing a rod-shaped ferrite magnet by grinding the sintered body, by performing at least a part of the chamfering processing at the axial end of the rod-shaped ferrite magnet in the forming step,
A feature of the ferrite magnet is that a shape viewed in a cross section perpendicular to the axial direction is a shape surrounded by an arcuate outer circumference and an inner circumference, and the outer peripheral convex direction and the inner peripheral convex direction are opposite to each other.
【００２４】棒状フェライト磁石は断面の厚さが一定で
ない。特に、内周面と外周面が近接もしくは接続する稜
線の端（端面の尖った部分）を加工工程で面取りしよう
とすると、チッピング（カケ）を生じ易いという問題が
ある。そこで、稜線の端に予め面取り形状を付けられる
ように、金型もしくはパンチの少なくとも1つを予め面
取り面に応じた形状に設計しておき、成形工程で稜線の
端を面取り加工することで稜線の端のチッピングを無く
し、歩留まりを向上させる（型面取り）。より望ましく
は稜線全体を面取りすることや、端面の全周に面取りを
施すことについても、成形体工程で行うと更に歩留まり
を向上させることができる。The rod-shaped ferrite magnet does not have a constant cross-section thickness. In particular, there is a problem that chipping (chip) is likely to occur when chamfering the edge (the pointed portion of the end surface) of the ridgeline where the inner peripheral surface and the outer peripheral surface are close to or connected to each other in the processing step. Therefore, at least one of the mold or punch is designed in advance to have a shape corresponding to the chamfered surface so that the edge of the ridgeline can be preliminarily chamfered, and the edge of the ridgeline is chamfered in the molding process. Eliminates chipping at the edge of and improves the yield (mold chamfering). More desirably, the chamfering of the entire ridge line or the chamfering of the entire circumference of the end face can be further improved by performing the chamfering in the molding process.
【００２５】[0025]
【発明の実施の形態】以下、図面を用いて本発明の実施
形態を説明する。
（実施形態１）図１は本発明の一実施形態の斜視図であ
る。同図の（ａ）は端面２の形状が凸レンズ状である棒
状フェライト永久磁石１である。軸方向の長さＬ＝９０
ｍｍ、軸方向に垂直な厚さ成分：最大厚さｔ＝１０ｍｍ
とした。凸曲面である外周面３の曲率半径はＲ３０ｍｍ
とし、内周面４の曲率半径はＲ１５ｍｍとした。外周面
と内周面の境界は稜線５とした。（ａ）の棒状フェライ
ト永久磁石を軸方向に垂直な面でみた断面図を図２に示
す。外周面と内周面間の厚さｔは従来のアークセグメン
ト状フェライト永久磁石より厚く、外周面３側が強磁性
面となるように磁化を配向させた。外周面側について、
中央で測定した磁束密度は約２０００Ｇ、磁束量は３９
０００Ｍｘとなった。フェライト永久磁石の材料として
は、ｉＨｃ＝３４００Ｏｅ且つＢｒ＝４４００ＧのＬａ
ＣｏＳｒフェライト磁石を用いた。なお、ｉＨｃ＝４８
００Ｏｅ且つＢｒ＝４３００ＧのＬａＣｏＳｒフェライ
ト磁石を用いることもできた。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a perspective view of an embodiment of the present invention. 1A shows a rod-shaped ferrite permanent magnet 1 whose end face 2 has a convex lens shape. Axial length L = 90
mm, thickness component perpendicular to the axial direction: maximum thickness t = 10 mm
And The radius of curvature of the outer peripheral surface 3 which is a convex curved surface is R30 mm
The radius of curvature of the inner peripheral surface 4 was R15 mm. The boundary between the outer peripheral surface and the inner peripheral surface was the ridge line 5. FIG. 2 shows a cross-sectional view of the rod-shaped ferrite permanent magnet of (a) seen from a plane perpendicular to the axial direction. The thickness t between the outer peripheral surface and the inner peripheral surface is thicker than that of the conventional arc segment ferrite permanent magnet, and the magnetization is oriented so that the outer peripheral surface 3 side becomes a ferromagnetic surface. About the outer peripheral surface side,
The magnetic flux density measured at the center is about 2000 G, and the magnetic flux amount is 39
It became 000Mx. The material of the ferrite permanent magnet is La of iHc = 3400 Oe and Br = 4400 G.
A CoSr ferrite magnet was used. Note that iHc = 48
A LaCoSr ferrite magnet with 00 Oe and Br = 4300G could also be used.
【００２６】図１の（ｂ）は同様な棒状フェライト永久
磁石１０であり、さらに面取りなどを施したものであ
る。（ａ）の構成と異なる点を説明する。まず、内周面
１４の中央に平坦面１６を有し、外周面１３と内周面１
４の境界を面取りして形成した一組の平坦面１５を有す
る。外周面１３の曲率半径はＲ２５ｍｍとし、内周面１
４の曲率半径はＲ１５ｍｍとした。平坦面１５の幅ｔ２
は１．５ｍｍとし、平坦面１６の幅ｓは５ｍｍとした。
軸方向長さＬと幅ｔ２と幅ｓの向きはほぼ直交させた。
平坦面１６を冶具に固定しつつ外周面１３を加工したの
で、外周面の曲面形状を精度良く仕上げることができ
た。この精度によって、棒状フェライト永久磁石をロー
ターのスロットにガタツキなく収納することができた。FIG. 1B shows a similar rod-shaped ferrite permanent magnet 10, which is further chamfered. Differences from the configuration of (a) will be described. First, a flat surface 16 is provided at the center of the inner peripheral surface 14, and the outer peripheral surface 13 and the inner peripheral surface 1
4 has a set of flat surfaces 15 formed by chamfering the boundaries. The radius of curvature of the outer peripheral surface 13 is R25 mm, and the inner peripheral surface 1
The radius of curvature of No. 4 was R15 mm. Width t2 of flat surface 15
Was 1.5 mm, and the width s of the flat surface 16 was 5 mm.
The directions of the axial length L, the width t2, and the width s were substantially orthogonal to each other.
Since the outer peripheral surface 13 was processed while fixing the flat surface 16 to the jig, the curved surface shape of the outer peripheral surface could be accurately finished. Due to this accuracy, the rod-shaped ferrite permanent magnet could be stored in the rotor slot without rattling.
【００２７】次に、図１の（ｂ）の永久磁石の製造工程
を説明する。まず、炭酸ストロンチウム、フェマタイ
ト、酸化ランタン、酸化コバルトの各々の原料粉をｎ＝
５．９、ｘ＝０．０７５、ｙ＝ｘ／２ｎとなるように湿
式混合した。次に、ローターリーキルンによって温度１
２００℃、２時間大気中の条件で仮焼してクリンカーを
形成した。このクリンカーをローラーミルで解砕して粗
粉砕粉を得た。さらに、粗粉砕粉をアトライターで粉砕
しつつ炭酸ストロンチウム、酸化シリコン、炭酸カルシ
ウムを焼結助剤として添加し、ｘ＝０．１５、ｙ＝ｘ／
２ｎ、ｎ＝５．５５となるように酸化ランタン及び酸化
コバルトを添加し、湿式で微粉砕を行った。こうして平
均粒径が０．７〜０．８μｍの微粉を含むスラリーを得
た。Next, the manufacturing process of the permanent magnet shown in FIG. 1B will be described. First, n = each raw material powder of strontium carbonate, fematite, lanthanum oxide, and cobalt oxide.
Wet mixing was performed so that 5.9, x = 0.075, and y = x / 2n. Next, the temperature is set to 1 by the rotary kiln.
It was calcined at 200 ° C. for 2 hours in the air to form a clinker. The clinker was crushed with a roller mill to obtain coarsely crushed powder. Further, strontium carbonate, silicon oxide, and calcium carbonate were added as sintering aids while crushing the coarsely crushed powder with an attritor, and x = 0.15, y = x /
Lanthanum oxide and cobalt oxide were added so that 2n and n = 5.55 were obtained, and wet pulverization was performed. Thus, a slurry containing fine powder having an average particle size of 0.7 to 0.8 μm was obtained.
【００２８】次に、このスラリーを湿式成形装置７０内
に導入し、下パンチ７７とダイス７５と上パンチ７２に
囲われた空間に充填させた。図６に湿式成形装置の断面
図を示す。上下パンチによってスラリーを圧縮し、スラ
リー内の水分をパンチに設けたフィルター７４を通して
排出路７４から排出させ、コイル７６による１０ｋＯｅ
の磁場中で原料粉を成形体７１に成形した。得られた成
形体を１２１０〜１２３０℃で２時間焼成した。得られ
た焼結体の両面を回転砥石で研削加工して内周面と外周
面を形成し、断面が凸レンズ状の棒状焼結体とした。さ
らに内周面と外周面の境界の稜線を平面砥石で面取りし
て、棒状フェライト永久磁石を得た。Next, this slurry was introduced into the wet molding apparatus 70 and filled in the space surrounded by the lower punch 77, the die 75 and the upper punch 72. FIG. 6 shows a sectional view of the wet molding apparatus. The slurry is compressed by the upper and lower punches, the water content in the slurry is discharged from the discharge path 74 through the filter 74 provided in the punch, and the coil 76 causes 10 kOe.
The raw material powder was molded into the molded body 71 in the magnetic field. The obtained molded body was fired at 1210 to 1230 ° C. for 2 hours. Both surfaces of the obtained sintered body were ground with a rotary grindstone to form an inner peripheral surface and an outer peripheral surface to obtain a rod-shaped sintered body having a convex lens-shaped cross section. Furthermore, the ridgeline at the boundary between the inner peripheral surface and the outer peripheral surface was chamfered with a flat grindstone to obtain a rod-shaped ferrite permanent magnet.
【００２９】図１と同様の断面が目玉形状の棒状フェラ
イト磁石について、内周面の曲率半径を変えて複数のサ
ンプルを作製し、ローター表面の磁束密度分布を比較し
た。内周面側の曲率半径Ｒ＝１０ｍｍ、１５ｍｍ、２０
ｍｍ、２５ｍｍ、３０ｍｍの各々のサンプルについて、
磁束密度分布が正弦波状になり問題なく使用することが
できた。これに対して、曲率半径が１０ｍｍ未満になる
と、磁束密度分布の幅が狭くなりすぎてモーターで十分
なトルクを得ることができなくなった。曲率半径が３０
ｍｍを超えると、正弦波の中央付近がつぶれる傾向があ
り、コギングトルクの原因となった。このような結果か
ら内周面の曲率半径はＲ１０以上且つＲ３０以下が良い
ことが判った。With respect to the rod-shaped ferrite magnet having a cross section similar to that of FIG. 1, a plurality of samples were prepared by changing the radius of curvature of the inner peripheral surface, and the magnetic flux density distributions on the rotor surface were compared. Radius of curvature on the inner peripheral surface side R = 10 mm, 15 mm, 20
mm, 25 mm, 30 mm samples,
The magnetic flux density distribution became sinusoidal and could be used without problems. On the other hand, when the radius of curvature is less than 10 mm, the width of the magnetic flux density distribution becomes too narrow, and the motor cannot obtain sufficient torque. Radius of curvature is 30
If it exceeds mm, the vicinity of the center of the sine wave tends to be crushed, which causes cogging torque. From these results, it was found that the radius of curvature of the inner peripheral surface is preferably R10 or more and R30 or less.
【００３０】図３は、上記図１の棒状フェライト磁石を
ローターに用いたブラシレス３相モーターの概略を説明
する断面図である。ローター６０は、シャフト６１と、
ローター鉄心６３と外殻６３に囲われた４つのスロット
と、前記スロットの各々に挿入した本発明の棒状フェラ
イト磁石６４を主として構成した。棒状フェライト磁石
６４は、シャフト側を内周面４とし、ローターの外周側
を外周面３とした。ステーター５０は、ステーター鉄心
５１と、その内周側に一体に突出させた１２本のティー
ス５２と、ティース５２に巻いた巻線コイルを主として
構成した。図３では巻線コイルの断面の図示を省略した
が、多数回巻きつけたコイルをスロット５３に納めた。
ティース５２の先端は幅広で且つ端面が凹曲面になって
おり、円筒状であるローターの外殻６３との間に所定の
間隔（ギャップ５４）を持って対向させた。FIG. 3 is a sectional view schematically showing a brushless three-phase motor using the rod-shaped ferrite magnet shown in FIG. 1 as a rotor. The rotor 60 has a shaft 61,
The rotor core 63 and four slots surrounded by the outer shell 63, and the rod-shaped ferrite magnet 64 of the present invention inserted into each of the slots were mainly constituted. The rod-shaped ferrite magnet 64 has an inner peripheral surface 4 on the shaft side and an outer peripheral surface 3 on the outer peripheral side of the rotor. The stator 50 mainly includes a stator iron core 51, twelve teeth 52 that are integrally projected on the inner peripheral side thereof, and a winding coil wound around the teeth 52. Although illustration of the cross section of the wound coil is omitted in FIG. 3, the coil wound many times is housed in the slot 53.
The teeth 52 have wide ends and concave end surfaces, and are opposed to the cylindrical outer shell 63 of the rotor with a predetermined gap (gap 54).
【００３１】図３の概略構成をＡ−Ａ′に沿ってみた一
部断面図を図４に示す。ティース５２に巻いた巻線コイ
ル５３ｂはステーター鉄心５１に対して、シャフト６１
の軸方向に飛び出している。棒状フェライト永久磁石の
磁界はティースと巻線コイルに対して印加された。これ
に対し、従来の永久磁石を用いたローターは端部の磁界
が、軸方向に大きく曲がるため、巻線コイル５３ｂの端
部で受ける磁束密度が、巻線コイル５３ｂの中央部で受
ける磁束密度に比べて低下した。FIG. 4 is a partial sectional view of the schematic configuration of FIG. 3 taken along the line AA '. The winding coil 53b wound around the tooth 52 is attached to the shaft 61 with respect to the stator core 51.
Is protruding in the axial direction. The magnetic field of the rod-shaped ferrite permanent magnet was applied to the tooth and the winding coil. On the other hand, in the rotor using the conventional permanent magnet, the magnetic field at the end is greatly bent in the axial direction, so the magnetic flux density received at the end of the winding coil 53b is the magnetic flux density received at the center of the winding coil 53b. Decreased compared to.
【００３２】図３及び４の構成を用いることにより、従
来の構造に比べてコギングトルクを４０％以下に低減す
ることができた。さらに、モーターの効率を１０％改善
することができた。これらの結果は、棒状フェライト磁
石の内周面曲率半径を所定範囲に納め、更に軸方向にお
ける磁束密度分布を均一化したことに依ると考えられ
る。By using the configuration shown in FIGS. 3 and 4, the cogging torque could be reduced to 40% or less as compared with the conventional structure. Furthermore, the efficiency of the motor could be improved by 10%. It is considered that these results are due to the fact that the radius of curvature of the inner peripheral surface of the rod-shaped ferrite magnet is set within a predetermined range and the magnetic flux density distribution in the axial direction is made uniform.
【００３３】（実施形態２）図５は、面取りを行った棒
状フェライト永久磁石の一部側面図である。同図（ｄ）
は、成形工程において内周面２４と外周面２３間に型面
取りで平坦面２５を施し、加工工程において端面２２の
全周にＣ面取りを施した棒状フェライト永久磁石３０で
ある。同図（ｅ）は、成形工程において端面に型面取り
を行った棒状フェライト永久磁石３０である。外周面３
３と内周面３４の境界に型面取りで平坦面３５を設け
た。この平坦面の端は同様に型面取りでＲ面取り３５ｂ
を施した。磁石の端面３２の周囲にはＲ面取り３５ｂ以
外に、内周面側にＣ面取り３７を施し、外周面側にＣ面
取り３７ｂを施した。これらの面取りを行うことで、加
工時やスロット挿入時のカケを抑制することができた。(Embodiment 2) FIG. 5 is a partial side view of a chamfered rod-shaped ferrite permanent magnet. The same figure (d)
Is a rod-shaped ferrite permanent magnet 30 in which a flat surface 25 is formed between the inner peripheral surface 24 and the outer peripheral surface 23 by mold chamfering in the molding step, and C-chamfering is performed on the entire circumference of the end surface 22 in the processing step. FIG. 6E shows a rod-shaped ferrite permanent magnet 30 whose end face is chamfered in the molding process. Outer peripheral surface 3
A flat surface 35 was provided on the boundary between the inner peripheral surface 34 and the inner peripheral surface 3 by die chamfering. The edge of this flat surface is also chamfered with a mold to form a chamfer 35b.
Was applied. Around the end surface 32 of the magnet, in addition to the R chamfer 35b, a C chamfer 37 was provided on the inner peripheral surface side and a C chamfer 37b was provided on the outer peripheral surface side. By chamfering these, it was possible to suppress chipping during processing and slot insertion.
【００３４】上記図５の棒状フェライト磁石を用い、図
１とは異なるブラシレスモーターを検討したところ、実
施例１のモーターと同様の効果を得ることができた。ロ
ーターは６個のスロットを有し、各々に図５の棒状フェ
ライト永久磁石を挿入・固定したものを用いた。ステー
ターは、９本のティースを備えるステーター鉄心に巻線
コイルを設けたものを用いた。When a brushless motor different from that shown in FIG. 1 was examined by using the rod-shaped ferrite magnet shown in FIG. 5, the same effect as that of the motor of Example 1 could be obtained. The rotor had six slots, and the rod-shaped ferrite permanent magnet of FIG. 5 was inserted and fixed in each rotor. As the stator, a stator core provided with nine teeth and provided with winding coils was used.
【００３５】[0035]
【発明の効果】以上で説明したように、軸方向に垂直な
断面形状が紡錘形状であり、前記紡錘形状は外周面と内
周面で囲われており、前記内周面の曲率半径が１０ｍｍ
以上且つ３０ｍｍ以下である本発明の構成を用いること
により、強磁性面側に磁束を集中させても磁束密度の歪
みがほとんどなく、コギングトルクの発生を抑制するこ
とができる。As described above, the sectional shape perpendicular to the axial direction is the spindle shape, and the spindle shape is surrounded by the outer peripheral surface and the inner peripheral surface, and the radius of curvature of the inner peripheral surface is 10 mm.
By using the structure of the present invention having the length of 30 mm or less, even if the magnetic flux is concentrated on the ferromagnetic surface side, there is almost no distortion of the magnetic flux density, and the generation of cogging torque can be suppressed.
【図１】本発明に係る棒状フェライト磁石の斜視図であ
る。FIG. 1 is a perspective view of a rod-shaped ferrite magnet according to the present invention.
【図２】本発明に係る棒状フェライト磁石の断面図であ
る。FIG. 2 is a sectional view of a rod-shaped ferrite magnet according to the present invention.
【図３】ブラシレス３相モーターの断面図である。FIG. 3 is a cross-sectional view of a brushless three-phase motor.
【図４】図３の構成を軸方向に沿ってみた一部断面図で
ある。FIG. 4 is a partial cross-sectional view of the configuration of FIG. 3 as seen along the axial direction.
【図５】本発明の他の実施形態に係る一部側面図であ
る。FIG. 5 is a partial side view according to another embodiment of the present invention.
【図６】湿式成形装置の概略を示す断面図である。FIG. 6 is a sectional view showing the outline of a wet molding apparatus.
１ 棒状フェライト永久磁石、 ２ 端面、 ３ 外周
面、 ４ 内周面、５ 稜線、 １０ 棒状フェライト
永久磁石、 １３ 外周面、１４ 内周面、 １５ 平
坦面、 １６ 平坦面、２０ 棒状フェライト永久磁
石、 ２２ 端面、 ２３ 外周面、２４ 内周面、
２５ 平坦面、 ２７ Ｃ面取り、３０ 棒状フェライ
ト永久磁石、 ３２ 端面、 ３３ 外周面、３４ 内
周面、 ３５ 平坦面、 ３５ｂ Ｒ面取り、 ３７
Ｃ面取り、３７ｂ Ｃ面取り、５０ ステーター、 ５
１ ステーター鉄心、 ５２ ティース、５３ スロッ
ト、 ５３ｂ 巻線コイル、 ５４ ギャップ、６０
ローター、 ６１ シャフト、 ６２ ローター鉄心、
６３ 外殻、 ６４ 棒状フェライト永久磁石、７０
湿式成形装置、 ７１ 成形体、 ７２ 上パンチ、７
３ フィルター、 ７４ 排出路、 ７５ ダイス、７
６ コイル、 ７７ 下パンチ1 bar-shaped ferrite permanent magnet, 2 end surfaces, 3 outer peripheral surface, 4 inner peripheral surface, 5 ridge lines, 10 bar-shaped ferrite permanent magnet, 13 outer peripheral surface, 14 inner peripheral surface, 15 flat surface, 16 flat surface, 20 bar-shaped ferrite permanent magnet, 22 end surface, 23 outer peripheral surface, 24 inner peripheral surface,
25 flat surface, 27 C chamfer, 30 rod-shaped ferrite permanent magnet, 32 end surface, 33 outer peripheral surface, 34 inner peripheral surface, 35 flat surface, 35b R chamfer, 37
C chamfer, 37b C chamfer, 50 Stator, 5
1 stator core, 52 teeth, 53 slots, 53b winding coil, 54 gap, 60
Rotor, 61 shaft, 62 rotor core,
63 outer shell, 64 rod-shaped ferrite permanent magnet, 70
Wet molding machine, 71 molded body, 72 upper punch, 7
3 filter, 74 discharge path, 75 dice, 7
6 coils, 77 lower punch
Claims (9)
に垂直な断面形状が紡錘形状であり、前記紡錘形状は外
周面と内周面で囲われており、前記内周面の曲率半径が
１０ｍｍ以上且つ３０ｍｍ以下であることを特徴とする
フェライト磁石。1. A rod-shaped ferrite magnet, the cross-sectional shape of which is perpendicular to the axial direction is a spindle shape, and the spindle shape is surrounded by an outer peripheral surface and an inner peripheral surface, and the radius of curvature of the inner peripheral surface is A ferrite magnet having a length of 10 mm or more and 30 mm or less.
イト磁石であって、軸方向の断面が曲率の異なる二つの
円弧で囲われた形状をしており、一方の円弧が外周面で
あり、他方の円弧が内周面であり、前記内周面の曲率半
径が前記外周面の曲率半径より小さく、且つ内周面の曲
率半径が１０ｍｍ以上且つ３０ｍｍ以下であることを特
徴とするフェライト磁石。2. A rod-shaped ferrite magnet provided on a rotor of a rotating machine, wherein an axial cross section has a shape surrounded by two arcs having different curvatures, one arc being an outer peripheral surface and the other arc. The arc is the inner peripheral surface, the radius of curvature of the inner peripheral surface is smaller than the radius of curvature of the outer peripheral surface, and the radius of curvature of the inner peripheral surface is 10 mm or more and 30 mm or less.
ェライト磁石であって、軸方向の長さＬと外周面と内周
面間の最大厚さｔの関係は、０．０７≦ｔ／Ｌ≦０．３
であることを特徴とするフェライト磁石。3. The ferrite magnet according to claim 1, wherein the relationship between the axial length L and the maximum thickness t between the outer peripheral surface and the inner peripheral surface is 0.07 ≦ t. /L≦0.3
A ferrite magnet characterized in that
ライト磁石であって、軸方向の端に端面を備え、前記端
面の周囲の少なくとも一部に面取り加工または丸め加工
を施されていることを特徴とするフェライト磁石。4. The ferrite magnet according to claim 1, wherein an end face is provided at an end in the axial direction, and at least a part of the periphery of the end face is chamfered or rounded. A ferrite magnet characterized in that
ライト磁石であって、外周面側が強磁性面であることを
特徴とするフェライト磁石。5. The ferrite magnet according to claim 1, wherein the outer peripheral surface side is a ferromagnetic surface.
ライト磁石を用いることを特徴とする回転機。6. A rotating machine using the ferrite magnet according to any one of claims 1 to 5.
をプレスする成形装置でフェライトの成形体を作製する
成形工程と、前記成形体を焼成して焼結体を得る焼成工
程と、前記焼結体を研削加工して棒状フェライト磁石を
作製する加工工程を備え、 成形工程において下パンチで成形した側を凸面の外周面
とし、 軸方向に垂直な断面でみた形状が円弧状の外周と内周に
囲われた形状であり、外周の凸方向と内周の凸方向は逆
向きであるフェライト磁石を得ることを特徴とするフェ
ライト磁石の製造方法。7. A molding step of forming a ferrite molded body by a molding device that uses a die to press a material with an upper punch and a lower punch; and a firing step of firing the molded body to obtain a sintered body. It is equipped with a processing step to produce a rod-shaped ferrite magnet by grinding the sintered body, and the side formed by the lower punch in the forming step is the outer peripheral surface of the convex surface, and the arc-shaped outer periphery when viewed in a cross section perpendicular to the axial direction. A method for producing a ferrite magnet, characterized in that a ferrite magnet having a shape surrounded by an inner circumference and a convex direction on the outer circumference and a convex direction on the inner circumference are opposite to each other.
方法において、前記下パンチの側から磁界を印加するこ
とにより強磁性面を形成することを特徴とするフェライ
ト磁石の製造方法。8. The method of manufacturing a ferrite magnet according to claim 1, wherein a ferromagnetic surface is formed by applying a magnetic field from the side of the lower punch.
ライトの成形体を作製する工程と、前記成形体を焼成し
て焼結体を得る工程と、前記焼結体を研削加工して棒状
フェライト磁石を作製する加工工程を備え、 前記成形工程において、棒状フェライト磁石の軸方向の
端における面取り加工の少なくとも一部を行うことによ
り、 軸方向に垂直な断面でみた形状が円弧状の外周と内周に
囲われた形状であり、外周の凸方向と内周の凸方向は逆
向きであるフェライト磁石を得ることを特徴とするフェ
ライト磁石の製造方法。9. A step of producing a molded body of ferrite with a molding apparatus that presses a material with a mold, a step of firing the molded body to obtain a sintered body, and a grinding process of the sintered body to obtain a rod shape. In the forming step, at least a part of the chamfering at the axial end of the rod-shaped ferrite magnet is performed so that the shape of the cross section perpendicular to the axial direction is an arc-shaped outer circumference. A method for manufacturing a ferrite magnet, comprising obtaining a ferrite magnet having a shape surrounded by an inner circumference, and a convex direction of an outer circumference and a convex direction of an inner circumference are opposite to each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001356811A JP2003164082A (en) | 2001-11-22 | 2001-11-22 | Ferrite magnet, rotating machine and production method of ferrite magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001356811A JP2003164082A (en) | 2001-11-22 | 2001-11-22 | Ferrite magnet, rotating machine and production method of ferrite magnet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003164082A true JP2003164082A (en) | 2003-06-06 |
Family
ID=19168262
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001356811A Pending JP2003164082A (en) | 2001-11-22 | 2001-11-22 | Ferrite magnet, rotating machine and production method of ferrite magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003164082A (en) |
Cited By (9)
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| JP2005287271A (en) * | 2004-03-31 | 2005-10-13 | Honda Motor Co Ltd | Method for manufacturing rotor |
| JP2009022089A (en) * | 2007-07-11 | 2009-01-29 | Hitachi Ltd | Permanent magnet type rotary electric machine and permanent magnet type rotary electric machine system |
| CN101711313A (en) * | 2007-07-25 | 2010-05-19 | 约马-综合塑料技术有限公司 | Integrated internal gear pump with an electric motor |
| JP2013251948A (en) * | 2012-05-30 | 2013-12-12 | Mitsubishi Electric Corp | Permanent magnet embedded type electric motor |
| CN107394929A (en) * | 2017-09-22 | 2017-11-24 | 珠海格力节能环保制冷技术研究中心有限公司 | Rotor assembly and motor |
| JP2018125918A (en) * | 2017-01-30 | 2018-08-09 | シナノケンシ株式会社 | Outer rotor motor |
| JP2020068640A (en) * | 2018-10-26 | 2020-04-30 | 株式会社ｅ−Ｇｌｅ | Outer rotor motor and electric vehicle |
| EP3680919A1 (en) * | 2019-01-11 | 2020-07-15 | Kyocera Corporation | Core component, method of manufacturing same, and inductor |
| CN116599255A (en) * | 2023-04-06 | 2023-08-15 | 南京埃斯顿机器人工程有限公司 | Motor rotor structure and high-performance servo motor |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005287271A (en) * | 2004-03-31 | 2005-10-13 | Honda Motor Co Ltd | Method for manufacturing rotor |
| JP2009022089A (en) * | 2007-07-11 | 2009-01-29 | Hitachi Ltd | Permanent magnet type rotary electric machine and permanent magnet type rotary electric machine system |
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| CN101711313A (en) * | 2007-07-25 | 2010-05-19 | 约马-综合塑料技术有限公司 | Integrated internal gear pump with an electric motor |
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| JP2018125918A (en) * | 2017-01-30 | 2018-08-09 | シナノケンシ株式会社 | Outer rotor motor |
| CN107394929A (en) * | 2017-09-22 | 2017-11-24 | 珠海格力节能环保制冷技术研究中心有限公司 | Rotor assembly and motor |
| JP2020068640A (en) * | 2018-10-26 | 2020-04-30 | 株式会社ｅ−Ｇｌｅ | Outer rotor motor and electric vehicle |
| EP3680919A1 (en) * | 2019-01-11 | 2020-07-15 | Kyocera Corporation | Core component, method of manufacturing same, and inductor |
| CN116599255A (en) * | 2023-04-06 | 2023-08-15 | 南京埃斯顿机器人工程有限公司 | Motor rotor structure and high-performance servo motor |
| CN116599255B (en) * | 2023-04-06 | 2023-11-07 | 南京埃斯顿机器人工程有限公司 | Motor rotor structure and high-performance servo motor |
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