JPS62177903A - Permanent magnet type uniform magnetic-field magnet - Google Patents
Permanent magnet type uniform magnetic-field magnetInfo
- Publication number
- JPS62177903A JPS62177903A JP61019326A JP1932686A JPS62177903A JP S62177903 A JPS62177903 A JP S62177903A JP 61019326 A JP61019326 A JP 61019326A JP 1932686 A JP1932686 A JP 1932686A JP S62177903 A JPS62177903 A JP S62177903A
- Authority
- JP
- Japan
- Prior art keywords
- permanent magnet
- magnetic field
- section
- plate
- uniform magnetic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000696 magnetic material Substances 0.000 claims abstract description 6
- QNRATNLHPGXHMA-XZHTYLCXSA-N (r)-(6-ethoxyquinolin-4-yl)-[(2s,4s,5r)-5-ethyl-1-azabicyclo[2.2.2]octan-2-yl]methanol;hydrochloride Chemical compound Cl.C([C@H]([C@H](C1)CC)C2)CN1[C@@H]2[C@H](O)C1=CC=NC2=CC=C(OCC)C=C21 QNRATNLHPGXHMA-XZHTYLCXSA-N 0.000 claims description 3
- 230000004907 flux Effects 0.000 abstract description 39
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 6
- 229910052742 iron Inorganic materials 0.000 abstract description 3
- 229910000976 Electrical steel Inorganic materials 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 13
- 230000005415 magnetization Effects 0.000 description 10
- 239000000463 material Substances 0.000 description 9
- 230000008901 benefit Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000035699 permeability Effects 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000005481 NMR spectroscopy Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000011796 hollow space material Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 238000003325 tomography Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔発明の属する技術分野〕
本発明は核磁気共鳴コンビ二−タ断層像撮影装置（以下
ＮＭＲ−ＣＴと略称する）などに用いられる永久磁石形
均一磁場マグネソトに関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to a permanent magnet homogeneous magnetic field magnetograph used in a nuclear magnetic resonance combinatorial tomography apparatus (hereinafter abbreviated as NMR-CT).
ＮＭＲ−ＣＴにおいては、均一磁場マグネットに包囲さ
れた空間の中央部の直径４００〜５００ｗ８にの均一磁
場空間に、磁場の強さの均一度が数ｌ ＱＰＰＭという
均一磁場を発生させる必要があり、永久磁石を使用する
ことにより、常電導均一磁場コイルを用いる方式におけ
る膨大な電力消費、−！た超ｉｔｓマグネット方式にお
ける冷却用電力消費吟が排除でき、したがって運転コス
トの低い均一磁場マグネットが得られる利点があり注目
を集めている。しかしながら、永久磁石と銅線材の１曲
格全比較した場合、フェライト磁石で数倍。In NMR-CT, it is necessary to generate a uniform magnetic field with a uniformity of magnetic field strength of several liters QPPM in a uniform magnetic field space with a diameter of 400 to 500w8 at the center of the space surrounded by a uniform magnetic field magnet. By using permanent magnets, huge power consumption in the system using normal conducting uniform magnetic field coils, -! This method is attracting attention because it has the advantage of eliminating the power consumption required for cooling in the ultra-its magnet method, and therefore provides a uniform magnetic field magnet with low operating costs. However, when comparing the full curvature of permanent magnets and copper wires, ferrite magnets are several times larger.
希土類磁石では１００倍に達する程永久磁石が高価であ
るために、永久磁石の使用量が少く、かつ小形ａｍな永
久磁石形均一磁場マグネットの出現が求められている。Since permanent magnets are 100 times more expensive than rare earth magnets, there is a need for a permanent magnet type uniform magnetic field magnet that uses less permanent magnets and is small in size.
第１３図は従来技術を示す要部の正面図であり、方形筒
状に形成されたコア１の均一磁場の方向１００に垂直な
内壁面２Ａ 、２Ｂに、均−磁場方向１００と同方向に
磁化された永久磁石３Ａ、３Ｂと漏れ磁束を阻止するた
めの環状突起５を有する鉄板等の軟質磁性材からなる磁
極片４Ａ 、４Ｂとを設け、一対の磁極片４Ａ、４Ｂ間
の空隙６の中火部に直径４００ない１〜５００關程度の
均一磁場空間１０を形成するよう構成されている。とこ
ろが、磁極片４Ａ、４Ｂ間の空隙６の磁気抵抗が高いた
めに、磁極片の外周からコア１側に漏れ出す漏れ磁束１
０１を完全に阻止することは不可能であり、磁極とコア
との間の距離Ｓを大きくとって漏れ磁束１０１を低減す
るよう構成しても、なお漏れ磁束による空隙乙の磁束の
変歪により均一磁場１０の磁場の均一度が低下する。し
たがって、均一磁場１０の磁場の均一度を保持するため
に永久磁石３Ａ、３Ｂの直径が大きくなυ高価な永久磁
石材を多量に必要とし、そノ］、に伴なって総発生磁束
量が増大するためにこ力、金環流するコア１の断面積が
増太し、距離Ｓを保持するだめのコア１の磁路長の増大
と併せて均一磁場マグネットが高１葉化するという問題
があり、設置スペースの増大を考厘した場合にはさらに
大きな経済的不利益をもたらす欠点がおる。FIG. 13 is a front view of the main part showing the prior art, in which inner wall surfaces 2A and 2B of the core 1 formed in a rectangular cylindrical shape perpendicular to the direction 100 of the uniform magnetic field are placed in the same direction as the direction 100 of the uniform magnetic field. Magnetized permanent magnets 3A, 3B and magnetic pole pieces 4A, 4B made of a soft magnetic material such as an iron plate having an annular protrusion 5 for blocking leakage magnetic flux are provided, and a gap 6 between the pair of magnetic pole pieces 4A, 4B is provided. It is configured to form a uniform magnetic field space 10 with a diameter of about 400 mm or 1 to 500 mm in the medium heat section. However, since the magnetic resistance of the air gap 6 between the magnetic pole pieces 4A and 4B is high, leakage magnetic flux 1 leaks from the outer periphery of the magnetic pole pieces to the core 1 side.
01 cannot be completely prevented, and even if the distance S between the magnetic pole and the core is increased to reduce the leakage magnetic flux 101, the leakage flux still causes distortion of the magnetic flux in the air gap B. The uniformity of the magnetic field of the uniform magnetic field 10 is reduced. Therefore, in order to maintain the uniformity of the magnetic field 10, the permanent magnets 3A and 3B have large diameters and a large amount of expensive permanent magnet material is required. Due to this increase, the cross-sectional area of the core 1 through which the metal ring flows increases, and along with the increase in the magnetic path length of the core 1 that maintains the distance S, there is a problem that the uniform magnetic field magnet becomes one leaf high. However, if consideration is given to an increase in the installation space, there is a drawback that it brings about an even greater economic disadvantage.
第１４図は改善された従来技術を示す要部の正面図であ
り、８個の台形棒状の永久磁石１６を八角筒状に組合わ
せてその内側に六角形の均一磁場空間１６を形成するよ
う構成されておシ、図中実線矢印で示す各永久磁石の磁
化の方向１０２を、均一磁場の方向１００に対して各永
久磁石がなす角度θの２倍の角度方向とすることにより
、発生磁束を八角筒状の均一磁場マグネット内に閉じ込
めることができ、コアを用いずに漏れ磁束１０１の量を
低減できるとともに、均一磁場マグネットの中空部を広
く均一磁場空間として利用できることにより総発生磁束
量も少くてすみ、外径寸法を縮小できるなどの利点を有
する。しかしながら、永久磁石１６を総発生磁束の循環
通路に利用しているために台形の高さ方向の寸法が犬き
くなシ、高価な永久磁石材を多量に使用する必要があシ
、経済的不利益をまねくとともに、永久磁石１６それぞ
れの磁化の方向が異なるために、その着磁処理および組
立加工に困難が伴うと考えられる。FIG. 14 is a front view of a main part showing an improved conventional technique, in which eight trapezoidal bar-shaped permanent magnets 16 are combined into an octagonal tube shape to form a hexagonal uniform magnetic field space 16 inside. By setting the magnetization direction 102 of each permanent magnet shown by the solid line arrow in the figure to an angle twice the angle θ that each permanent magnet makes with respect to the direction 100 of the uniform magnetic field, the generated magnetic flux is can be confined within the octagonal cylindrical uniform magnetic field magnet, reducing the amount of leakage magnetic flux 101 without using a core, and the hollow part of the uniform magnetic field magnet can be widely used as a uniform magnetic field space, thereby reducing the total amount of generated magnetic flux. It has the advantage of being small in amount and being able to reduce the outer diameter. However, since the permanent magnet 16 is used as a circulation path for the total generated magnetic flux, the height dimension of the trapezoid is quite large, and it is necessary to use a large amount of expensive permanent magnet material, resulting in economical inconvenience. However, since the direction of magnetization of each permanent magnet 16 is different, it is considered that the magnetization process and assembly process are difficult.
本発明は前述の状況に艦みてなされたもので、コアの中
空部を均一磁場として広く活用できることによシ総発生
磁束量が少く、かつ永久磁石材の使用量の少い永久磁石
形均一磁場マグネットを提供することを目的とする。The present invention has been made in view of the above-mentioned situation, and it is possible to widely utilize the hollow part of the core as a uniform magnetic field, thereby reducing the total amount of generated magnetic flux and using a small amount of permanent magnet material. The purpose is to provide magnets.
本発明は、永久磁石材料の比透磁率が空気のそれに近く
中空部の磁場を乱さないこと、板状の永久磁石の断面形
状とその磁化の方向との組合せによ＃）％定の面に所定
の電流が板の長さ方向に一様に流れる断面積が零の理想
導体（カーレントシートと呼ぶ）にＩｔきかえて考えら
れることなどに着目することによシなされたもので、総
発生磁束の循環通路となる軟質磁性材よシなるコアを多
角筒状に形成し、その内壁面のうち均一磁場方向に垂直
な内壁面には、台形断面を有する板状に形成され互いに
平行な二面に垂直な方向に磁化された台６一
形断面を有する板状永久磁石を１幅の広い底面側が前記
内壁面を密接して徨うよう配し、前記内壁面と異なる角
度方向の内壁面には、断面が長辺。The present invention is characterized by the fact that the relative magnetic permeability of the permanent magnet material is close to that of air and does not disturb the magnetic field in the hollow part, and by the combination of the cross-sectional shape of the plate-shaped permanent magnet and the direction of its magnetization, It was developed by focusing on the fact that it can be considered as an ideal conductor (called a current sheet) with a cross-sectional area of zero in which a given current flows uniformly in the length direction of the plate, and the total generated A core made of a soft magnetic material that serves as a circulation path for magnetic flux is formed in the shape of a polygonal cylinder, and on the inner wall surface perpendicular to the direction of the uniform magnetic field, there are two parallel plates formed in the shape of a trapezoidal cross section. A plate-like permanent magnet having a flat cross section of a table 6 magnetized in a direction perpendicular to the surface is arranged so that its wide bottom side closely follows the inner wall surface, and the inner wall surface is in a different angular direction from the inner wall surface. The cross section is the long side.
短辺および申送を有する不等辺三角形に形成され申送側
の面に垂直な方向に磁化された不等辺三角形断面を有す
る板状の永久磁石全長辺側の面が内壁面を密接して機う
よう配するとともに、例えば不等辺三角形断面を有する
板状の永久磁石の短辺側の面および台形断面を有する板
状の永久磁石の傾斜面とからなシ内壁面の境界線を通る
共通の接合面の中空部側の端すなわち不等辺三角形断面
を有する板状の永久磁石の頂点の一つを、前記境界線を
中心とし前記台形断面を有する板状の永久磁石の厚みを
半径とする円周上の接線と一致させるよう構成したこと
により、中空部と永久磁石との界面におけるカーレント
シートは永久磁石の磁化の方向がこの面に直交するとい
う条件により消去されて′この面における磁場の乱れが
排除され、隣接する永久磁石の接合面におけるカーレン
トシートは接合面の位［’ｆｒ前述の条件に適合させる
ことによシ消去されて接合部における磁場の乱れが排除
され、その結果、不等辺三角形断面を有する板状の永久
磁石とコアの内壁面との界面にのみカーレントシートを
配したと等価な状ねとすることが６Ｊ能となり均一磁場
と異なる方向の漏れ磁束を阻止できることによシ、各板
状の永久磁石の極性方向を内壁面が均一磁場方向に対し
てなす角度に対応して均一磁場の発生に好適な極性とす
ることによシ、コアの内側の板状の永久磁石を除く中空
部全体に均一磁場を発生できるようにしたものである。A plate-shaped permanent magnet with a scalene triangular cross section that is magnetized in the direction perpendicular to the surface on the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the surface of the plate is placed in close contact with the inner wall surface. For example, a common line passing through the short side surface of a plate-shaped permanent magnet having a scalene triangular cross section and the inclined surface of a plate-shaped permanent magnet having a trapezoidal cross section and the boundary line of the inner wall surface of the frame. The end of the joint surface on the hollow side, that is, one of the apexes of the plate-shaped permanent magnet having a scalene triangular cross section, is a circle whose center is the boundary line and whose radius is the thickness of the plate-shaped permanent magnet having the trapezoidal cross section. By arranging the lines to coincide with the tangents on the circumference, the current sheet at the interface between the hollow part and the permanent magnet is erased by the condition that the magnetization direction of the permanent magnet is perpendicular to this plane, and the magnetic field on this plane is The disturbances are eliminated, and the current sheet at the joint surfaces of adjacent permanent magnets is eliminated by matching the above conditions to the position of the joint surface ['fr], and the disturbance of the magnetic field at the joint is eliminated, so that By creating a state equivalent to arranging a current sheet only at the interface between a plate-shaped permanent magnet having a scalene triangular cross section and the inner wall surface of the core, it is possible to obtain a 6J function and prevent leakage magnetic flux in a direction different from that of a uniform magnetic field. In addition, by setting the polar direction of each plate-shaped permanent magnet to a polarity suitable for generating a uniform magnetic field in accordance with the angle that the inner wall surface makes with respect to the direction of the uniform magnetic field, the plate-shaped permanent magnet inside the core A uniform magnetic field can be generated throughout the hollow part except for the permanent magnet.
以下本発明を実施例に基づいて説明する。 The present invention will be explained below based on examples.
第１図は本発明の実施例装置の概略斜視図、第２図は第
１図の正面図である。図において、２１は鉄板、けい素
鋼板等の軟質磁性材からなる方形筒状のコアであシ、均
一磁場方向１００に垂直な内壁ＦｋＪ２人および２Ｂに
は主磁束を発生する一対の台形断面を有する板状の永久
磁石２３Ａ、２５Ｂが、また均一磁場方向１００に平行
な内壁面２Ｃ，２Ｄ側には、不等辺三角形断面合有する
４個の板状の永久磁石２４Ａ 、２４Ｂ 、２５Ａ 、
２５Ｃが、長辺側の面が内壁面２Ｃ，２ＤＫ密接し、短
辺側の面が台形断面を有する板状の永久磁石２３Ａ、２
３Ｂの傾斜面にそれぞれ接合して内壁面の境界［２７’
に通る接合面２８を形成するとともに、各永久磁石は中
空部２６との界面に垂直な方向に、かつ図中Ｎ４−８で
示す極性方向に一様に磁化されることにより、中空部２
６の長さ方向の中央部に方形の中空部２６全体に広がっ
た均一磁場１０を発生できるよう構成されている。FIG. 1 is a schematic perspective view of an apparatus according to an embodiment of the present invention, and FIG. 2 is a front view of FIG. 1. In the figure, 21 is a rectangular cylindrical core made of a soft magnetic material such as an iron plate or a silicon steel plate, and an inner wall FkJ2 perpendicular to the uniform magnetic field direction 100 and 2B have a pair of trapezoidal cross sections that generate the main magnetic flux. The plate-shaped permanent magnets 23A, 25B have four plate-shaped permanent magnets 24A, 24B, 25A with scalene triangular cross sections on the inner wall surfaces 2C, 2D parallel to the uniform magnetic field direction 100.
25C is a plate-shaped permanent magnet 23A, 2 whose long side surface is in close contact with the inner wall surface 2C, 2DK, and whose short side surface has a trapezoidal cross section.
3B and the boundary of the inner wall surface [27'
At the same time, each permanent magnet is uniformly magnetized in the direction perpendicular to the interface with the hollow part 26 and in the polar direction indicated by N4-8 in the figure.
It is configured to generate a uniform magnetic field 10 that spreads over the entire rectangular hollow part 26 at the center of the lengthwise direction of the magnet 6 .
第６図は不等辺三角形断面を有する板状の永久磁石の形
状決定とカーレントシートへの置きかえの原理的説明図
であり、第２図の右上の部分を例に説明しようとするも
のである。図において長辺ＡＢが内壁向２Ｄの幅の半分
に相当する長さを有する不等辺三角形断面ＡＢＣに形成
される板状の永久磁石２４Ａの申送Ｂｅの位置は、頂点
Ａ（内壁面の境界線２７）を中心とし、台形断面を有す
る板状の永久磁石２３Ａの厚みｄを半径とする円周面２
９と頂点Ｂとを結ぶ接ＩｖｉＩＢＤに一致するよう決め
られ、也点Ｃの位置は上記接＆ＩＢＤと台形断面を有す
る板状の永久磁石の中空部側の底辺とが交差する位置に
決められることにより、両永久磁石の間に共通の接合面
２８（辺ＡＣ）が形成される。Figure 6 is an explanatory diagram of the principle of determining the shape of a plate-shaped permanent magnet with a scalene triangular cross section and replacing it with a current sheet, and is intended to be explained using the upper right part of Figure 2 as an example. . In the figure, the position of the transmission Be of the plate-shaped permanent magnet 24A formed in the scalene triangular cross section ABC in which the long side AB has a length equivalent to half the width of the inner wall direction 2D is at the vertex A (the boundary of the inner wall surface). A circumferential surface 2 whose center is line 27) and whose radius is the thickness d of the plate-shaped permanent magnet 23A having a trapezoidal cross section.
9 and the vertex B, and the position of the point C is determined to be the intersection of the tangent &IBD and the bottom side of the hollow part of the plate-shaped permanent magnet having a trapezoidal cross section. As a result, a common joint surface 28 (side AC) is formed between both permanent magnets.
上述のように形状決定され保磁力ＨＯで申送ＢＣに垂直
な方向に磁化された不等辺三角形断面を有する板状の永
久磁石２４Ａは、短辺ＡＯと長辺ＡＢ上に互いに逆向き
の電流工を通ずる細線を想定して長さｄなるＡＤ力方向
均等な密度で配列した状態、すなわちカーレントシート
に置きかえて考えることができ、カーレントシートそれ
ぞれのアンペアターンは保磁力Ｈａと辺ＡＤの長さｄと
の積で与えられる。また台形断面を有する板状の永久磁
石２３Ａの傾斜面ＡＣについても電流工を通ずるｌｌ１
ｌｌＩｉ！を厚みｄ方向に均等に配列したカーレントシ
ートに置き換えて考えることができ、接合部１２８にお
ける二つの力〜レントシ一トの大キサが吟しく電流が逆
向きとなることによシカーレン−１〇−
トシートは互いに打消しあって零となり、不等辺三角形
断面を有する板状の永久磁石２４Ａの長辺ＡＢ側に配さ
れたカーレントシートのみが残される。The plate-shaped permanent magnet 24A, which has a scalene triangular cross section whose shape is determined as described above and is magnetized in a direction perpendicular to the sender BC with a coercive force HO, receives currents in opposite directions on the short side AO and the long side AB. Assuming thin wires passing through the wire, it can be thought of as a state in which they are arranged with equal density in the direction of AD force of length d, that is, in place of a current sheet, and the ampere turn of each current sheet is calculated by the coercive force Ha and the side AD. It is given by the product of length d. In addition, the slope AC of the plate-shaped permanent magnet 23A having a trapezoidal cross section is also
llIi! can be considered by replacing it with a current sheet arranged evenly in the thickness direction d, and the two forces at the joint 128 - the large excursion of the current sheet is large and the current is in the opposite direction. - The current sheets cancel each other out and become zero, leaving only the current sheet disposed on the long side AB of the plate-shaped permanent magnet 24A having a scalene triangular cross section.
第４図は第２図のように形成された均一磁場マグネット
のカーレントシートの状態を示゛す説明図でめ）、コア
２１の内壁面２Ｃおよび２Ｄに配され電流の向きをクロ
ス・ドツト記号で示すカーレントシート３ＱＣ，３０１
）で均一磁場マグネットを等価的に置き換えることがで
きる。FIG. 4 is an explanatory diagram showing the state of the current sheet of the uniform magnetic field magnet formed as shown in FIG. 2). Current sheet shown by symbols 3QC, 301
) can equivalently replace the uniform field magnet.
第５図は前述の実施例における磁束分布図であり、第４
図に示すカーレントシート配置により等価的に求められ
たものである。図から明らかなように、カーレントシー
ト３０Ｃ，３０Ｄにょｐ内壁面２０，２Ｄに交差する漏
れ磁束を完全に排除できるので、磁束線１１０は完全に
ｈ線かつ等間隔であり、永久磁石を含めたコア２１の中
空部全体に均一磁場空間１０を発生できることを示して
いる。なお永久磁石２３Ａ、２４Ａの永久磁石材を比透
磁率が１．０５以下のバリウムフェライト磁石あるいｅ
、１８十類磁石で形成するとともに、永久磁石の磁化面
＆ｌを減磁処理などにより内線化すね、げ、カーレント
シートを永久磁石で置き換えても第５図に小すと同様な
均一磁場を発生する永久磁石形均一磁場マグネットを得
ることかできる。FIG. 5 is a magnetic flux distribution diagram in the above-mentioned embodiment, and the fourth
This is equivalently obtained using the current sheet arrangement shown in the figure. As is clear from the figure, leakage magnetic flux crossing the inner wall surfaces 20, 2D of the current sheets 30C, 30D can be completely eliminated, so the magnetic flux lines 110 are completely H-lines and equally spaced, including the permanent magnets. This shows that a uniform magnetic field space 10 can be generated throughout the hollow portion of the core 21. The permanent magnets 23A and 24A are made of barium ferrite magnets with a relative magnetic permeability of 1.05 or less.
, 180 class magnet, and by demagnetizing the magnetized surface &l of the permanent magnet and replacing the inner wire, ridge, and current sheet with permanent magnets, the same uniform magnetic field as shown in Fig. 5 can be obtained. It is possible to obtain a permanent magnet type uniform magnetic field magnet.
第６図は前述の実施例の比較例を示す磁束分布図であり
、不等辺三角形断面を壱する板状の永久磁石２４Ａの磁
化の方向Ｎ −＋ ８を内壁面２Ｄに密接した長辺ＡＢ
側の而に画論な方向と１７だ点が前述の実施例と異なっ
ており、この場合にはカーレントシートを中込ＢＣ側の
中空部との性向と短辺ＡＣ側の接合面２８とに配した等
価となるために、不等辺三角形断面を有する板状の永久
磁石２４Ａ内における磁束線１１０が大幅に乱れ、内壁
面２Ｄに垂直な漏り、磁束１０２が発生する。この磁束
線の乱れが均一磁場空間１０の磁場の均一度にも影響を
及ぼすので前述の実施例に比べ磁場の均一度は大幅に低
下する。FIG. 6 is a magnetic flux distribution diagram showing a comparative example of the above-described embodiment, in which the magnetization direction N −+ 8 of a plate-shaped permanent magnet 24A having a scalene triangular cross section is set to the long side AB close to the inner wall surface 2D.
It is different from the above-mentioned embodiment in that the drawing direction of the side is 17. In this case, the current sheet is placed in the direction of the hollow part on the BC side and the joint surface 28 on the short side AC side. As a result, the magnetic flux lines 110 within the plate-shaped permanent magnet 24A having a scalene triangular cross section are significantly disturbed, and leakage and magnetic flux 102 perpendicular to the inner wall surface 2D are generated. This disturbance of the magnetic flux lines also affects the uniformity of the magnetic field in the uniform magnetic field space 10, so that the uniformity of the magnetic field is significantly reduced compared to the previous embodiment.
前述の第５図および第６図を比較することにより明らか
なように、台形断面を有する板状の永久磁石と不等辺三
角形断面を廟する板状の永久磁石とを単に額縁状に接合
するだけでは均一磁場を発生させることは不用能であり
、両永久磁石の磁化をそれぞれ中空部との界面に垂直方
向に行うことによって界面のカーレントシートを排除し
、不等辺三角形断１１］］ｋ有する板状の永久磁石の形
状を特定することにより両永久磁石の接合面におけるカ
ーレントシートを排除し、不等辺三角形断面を有する板
状の永久磁石の内壁側界面にのみカーレントシートを残
すよう構成するとともに、両永久磁石の磁化の極性を第
２図に示すように内壁面２Ｃ＋２ＤＫ直交する漏れ磁束
を反発する極性とすることによシ、内壁面２Ｃ，２Ｄに
直交する漏れ磁束１１０は完全に排除され、コア２１の
内側の中空部全体に広がる均一磁場１０を発生させるこ
とができる。したがって、台形断面を有する板状の永久
磁石２３Ａ、２３Ｂの厚みｄは均一磁場空間１０に均一
磁場を発生させるに必要な最小重量ですむので永久磁石
を＠量化することができ、かつ均一磁場空間としての中
空部の利用率が高く、漏れ磁束が排除されて酩発生磁宋
址が減るのでコア２１０寸法、車ｉを必要最小限に低減
することができる。As is clear by comparing the above-mentioned FIGS. 5 and 6, a plate-shaped permanent magnet having a trapezoidal cross section and a plate-shaped permanent magnet having a scalene triangular cross section are simply joined together in a frame shape. In this case, it is not necessary to generate a uniform magnetic field, and by magnetizing both permanent magnets in the direction perpendicular to the interface with the hollow part, the current sheet at the interface is eliminated, and the scalene triangle section 11]k is created. By specifying the shape of the plate-shaped permanent magnet, the current sheet is eliminated at the joint surface of both permanent magnets, and the current sheet is left only at the interface on the inner wall side of the plate-shaped permanent magnet with a scalene triangular cross section. At the same time, by setting the polarity of magnetization of both permanent magnets to a polarity that repels the leakage magnetic flux perpendicular to the inner wall surfaces 2C+2DK as shown in FIG. 2, the leakage magnetic flux 110 perpendicular to the inner wall surfaces 2C and 2D is completely A uniform magnetic field 10 can be generated that spreads throughout the hollow space inside the core 21. Therefore, the thickness d of the plate-shaped permanent magnets 23A and 23B having a trapezoidal cross section is the minimum weight necessary to generate a uniform magnetic field in the uniform magnetic field space 10, so the permanent magnets can be quantified, and the uniform magnetic field space Since the utilization rate of the hollow part is high, leakage magnetic flux is eliminated, and the amount of magnetic flux generated is reduced, the dimensions of the core 210 and the diameter of the core 210 can be reduced to the necessary minimum.
第７図は本発明の異なる実施例を示す正面図、第８図は
カーレントシートの状態の説明図であり、方形筒状のコ
ア３１の内側に台形断面を有する板状の永久磁石３３Ａ
と、これに接合した一対の不等辺三角形断面を有する板
状の永久磁石６４Ａ。FIG. 7 is a front view showing a different embodiment of the present invention, and FIG. 8 is an explanatory diagram of the state of the current sheet, in which a plate-shaped permanent magnet 33A having a trapezoidal cross section is placed inside a rectangular cylindrical core 31.
and a pair of plate-shaped permanent magnets 64A having a scalene triangular cross section joined thereto.
６５Ａのみ金配した非対称構造とした点が前述の実施例
と異なっているが、カーレントシートは第８図に示すよ
うに前述の実施例と同じになり、不等辺三角形断面を有
する板状の永久磁石の靴断面積が前述の実施例のそれの
２倍になることを除けば前述の実施例と同様な性能を得
ることができる。It differs from the previous embodiment in that it has an asymmetrical structure in which only 65A is provided with gold, but the current sheet is the same as the previous embodiment as shown in Figure 8, and is a plate-shaped sheet with a scalene triangular cross section. Performance similar to the previous embodiment can be obtained except that the shoe cross-sectional area of the permanent magnet is twice that of the previous embodiment.
第９図は本発明のさらに異なる実施例を示す正面図、＃
ｉ１０図はカーレントシートの状態の説明図である。第
９図において、コア４１は六角筒状に形成されてお９、
その内壁面には台形断面を有する板状の永久磁石４３Ａ
と不等辺三角形断面を有する板状の永久磁石４４Ａ、４
５Ｂからなる永久磁石組と、この永久磁石組と対称に配
された４３Ｂ、４４Ｂ、４５Ｂからなる永久磁石組とが
配され、それぞれの永久磁石が均一磁場空間１０との界
面に垂直な方向に図中矢印で示す極性に磁化されること
により、均一磁場空間１０内に均一磁場方向１００で示
す均一磁場を発生するよう構成されている。なお、不等
辺三角形断面を有する板状の永久磁石の形状および接合
面の位置の決定は第６図に基づいて説明した前述の実施
例と同様であるが、不等辺三角形断面を有する板状の永
久磁石の磁化の方向の厚みの内壁面に沿った変化量は、
内壁面が均一磁場方向１００に対してなす角度θの余弦
に比例し、θの増大とともに減少する。第９図のように
構成された均一磁場マグネットは、第１０図に示すカー
レントシート配置に置きかえることができる。また第９
図、第１０図から明らかなように、不等辺三角形断面を
有する板状の永久磁石は、台形断面を有する板状の永久
磁石で発生した主磁束の変φを阻止するのみでなく、主
磁束の一部を発生する機能をはたしていることがわかる
。FIG. 9 is a front view showing still another embodiment of the present invention, #
Figure i10 is an explanatory diagram of the state of the current sheet. In FIG. 9, the core 41 is formed into a hexagonal cylinder shape.
A plate-shaped permanent magnet 43A having a trapezoidal cross section is attached to the inner wall surface.
A plate-shaped permanent magnet 44A, 4 having a scalene triangular cross section.
A permanent magnet set consisting of 5B and a permanent magnet set 43B, 44B, and 45B arranged symmetrically with this permanent magnet set are arranged, and each permanent magnet is arranged in a direction perpendicular to the interface with the uniform magnetic field space 10. It is configured to generate a uniform magnetic field shown in a uniform magnetic field direction 100 within a uniform magnetic field space 10 by being magnetized with the polarity shown by the arrow in the figure. Note that the shape of the plate-shaped permanent magnet having a scalene triangular cross section and the determination of the position of the bonding surface are the same as in the above-mentioned embodiment described based on FIG. The amount of change in the thickness of the permanent magnet in the direction of magnetization along the inner wall surface is:
It is proportional to the cosine of the angle θ that the inner wall surface makes with respect to the uniform magnetic field direction 100, and decreases as θ increases. The uniform magnetic field magnet configured as shown in FIG. 9 can be replaced with the current sheet arrangement shown in FIG. Also the 9th
As is clear from Figures 1 and 10, a plate-shaped permanent magnet with a scalene triangular cross section not only prevents the main magnetic flux from changing φ generated in a plate-shaped permanent magnet with a trapezoidal cross section, but also prevents the main magnetic flux from changing φ. It can be seen that it functions to generate a part of the .
第１１図は本発明の他の実施例を示す正面図、第１２図
は第１１図におけるカーレントシートの状態の説明図で
ある。第１１図において、コア５１は菱形筒状に形成さ
れ、その内壁面に短辺側の面が相互に接合された不等辺
三角形断面を有する板状の永久磁石５４Ａ、５５Ａと５
４Ｂ、５５Ｂとの２対の永久磁石対が上下方向に対称に
配され、各永久磁石が均一磁場１０との界面に垂直な方
向に図中矢印で示す極性に磁化されることによシ、縦方
向の対角線に沿った均一磁場方向１００の均一磁場を発
生するよう構成されておシ、各永久磁石対の接合面もま
た対角線に沿った方向に形成される。このように構成さ
れた均一磁場マグネットのカーレントシートは第１２図
に示す配置とな気合形断面を有する板状の永久磁石の機
能を不等辺三角形断面を有する板状の永久磁石が兼ねて
主磁束の発生と漏れ磁束の阻止の両機能をはだすことに
よシ前述の各実施例と同様な性能を有する永久磁石形均
一磁場でグネットを得ること必；できる。FIG. 11 is a front view showing another embodiment of the present invention, and FIG. 12 is an explanatory diagram of the state of the current sheet in FIG. 11. In FIG. 11, a core 51 is formed into a rhombic cylindrical shape, and plate-shaped permanent magnets 54A, 55A and 5 each have a scalene triangular cross section and their short side surfaces are joined to each other on the inner wall surface.
Two pairs of permanent magnets 4B and 55B are arranged symmetrically in the vertical direction, and each permanent magnet is magnetized in the direction perpendicular to the interface with the uniform magnetic field 10 with the polarity shown by the arrow in the figure. It is configured to generate a uniform magnetic field in the direction 100 of a uniform magnetic field along a longitudinal diagonal line, and the joining surface of each permanent magnet pair is also formed in a direction along the diagonal line. The current sheet of the uniform magnetic field magnet constructed in this way has the arrangement shown in Fig. 12, where the plate-shaped permanent magnet with the scalene triangular cross-section also serves as the main function of the plate-shaped permanent magnet with the Kiai-shaped cross section. By performing both the functions of generating magnetic flux and blocking leakage magnetic flux, it is possible to obtain a magnet with a permanent magnet type uniform magnetic field having the same performance as in each of the above-described embodiments.
なお、前述の各実施例におい王、永久磁石材の比透磁率
が１より僅かに大きいことが問題となる永久磁石形均一
磁場マグネットにおいては、不等辺三角形断面を有する
板状の永久磁石の磁化の方向を所定の算式に基づいて均
一磁場の界面に対して垂直な方向から僅かに変位させる
ことによシ、中空部における磁場の乱れを補正すること
が可能である。In addition, in each of the above-mentioned embodiments, in a permanent magnet type uniform magnetic field magnet where the relative magnetic permeability of the permanent magnet material is slightly larger than 1, the magnetization of a plate-shaped permanent magnet having a scalene triangular cross section is By slightly displacing the direction of the uniform magnetic field from the direction perpendicular to the interface of the uniform magnetic field based on a predetermined formula, it is possible to correct the disturbance of the magnetic field in the hollow part.
本発明は前述のように、永久磁石材の比透磁率が１に近
いことに着目し、軟質磁性材からなるコアを多角筒状に
形成し、その中空部の均一磁場方向に垂直な内壁面には
台形断面を有する板状の永久磁石を、゛前記内壁面とは
異なる角度方向の内壁面には不等辺三角形断面を有する
板状の永久磁石をそれぞれ長辺側の面が内壁面を援うよ
う密接して配し、各永久磁石を中空部との界面に垂直な
方向に磁化するとともに、不等辺三角形断面を有する板
状の永久磁石の断面形状およびその短辺側の面を含む隣
接永久磁石の接合面を長辺側の面にのみカーレントシー
トが残る条件を満たすよう決めるよう構成した。その結
果、不等辺三角形断面を有する板状の永久磁石側の内壁
面に交差する漏れ磁束およびそれに基づく永久磁石内部
の磁場の乱れをほぼ完全に排除することができ、したが
って多角形の中空部全体に広がる均一磁場を発生するこ
とが可能となシ、一対の円板状永久磁石を用いた従来技
術において漏れ磁束による磁場の乱れを廻避するに必要
とされた永久磁石径の増大、それに基づく総発生磁束量
の増大、コアの断面積および磁路長の増大等永久磁石材
の使用量の増加や均一磁場マグネットの高重量化をうな
がす間鴎点が排除され、中空部の均一磁場空間としての
利用率が高く、永久磁石材の使用量および総発生磁束量
が少く、したがって小形、＠量な永久磁石形均一磁場マ
グネットを経済的に有利に提供することができる。また
、コアを有しない従来の永久磁石形均一磁場マグネット
において間亀となった永久磁石を発生磁束の循環通路に
利用することによって永久磁石材の一使用量が増大する
という間組点を、小形かつ安価な多角筒状のコアを用い
ることによシ排除できる利点が得られる。さらに、多角
筒状のコアは方形筒状、六角筒状、羨形筒状等多柚類の
形状の中から人体を収納するに好適な形状を選択できる
利点が得られる。As mentioned above, the present invention focuses on the fact that the relative magnetic permeability of the permanent magnet material is close to 1, and forms a core made of a soft magnetic material into a polygonal cylinder shape, and the inner wall surface perpendicular to the uniform magnetic field direction of the hollow part. A plate-shaped permanent magnet with a trapezoidal cross section is placed on the inner wall surface in a different angular direction from the inner wall surface, and a plate-shaped permanent magnet with a scalene triangular cross section is placed on the inner wall surface in a different angular direction from the inner wall surface, and the long side surface supports the inner wall surface. Each permanent magnet is magnetized in a direction perpendicular to the interface with the hollow part, and the cross-sectional shape of the plate-shaped permanent magnet having a scalene triangular cross section and the adjacent surface including the short side surface thereof are magnetized in a direction perpendicular to the interface with the hollow part. The bonding surfaces of the permanent magnets were configured to satisfy the condition that the current sheet remains only on the long side surfaces. As a result, it is possible to almost completely eliminate the leakage magnetic flux that crosses the inner wall surface on the side of the plate-shaped permanent magnet that has a scalene triangular cross section, and the disturbance of the magnetic field inside the permanent magnet based on this, and therefore the entire polygonal hollow part. It is possible to generate a uniform magnetic field that spreads over a wide area, and the diameter of the permanent magnet is increased, which was necessary to avoid disturbance of the magnetic field due to leakage flux in the conventional technology using a pair of disc-shaped permanent magnets. This eliminates the need for an increase in the amount of generated magnetic flux, increases in the cross-sectional area of the core, increases in the length of the magnetic path, etc., which increase the amount of permanent magnet material used, and increases the weight of uniform magnetic field magnets. It is possible to economically advantageously provide a permanent magnet type uniform magnetic field magnet that has a high utilization rate, uses a small amount of permanent magnet material, and has a small amount of generated magnetic flux, and is therefore small and large in size. In addition, by using the permanent magnet, which has become a gap in conventional permanent magnet type uniform magnetic field magnets without a core, as a circulation path for the generated magnetic flux, the amount of permanent magnet material used increases. By using an inexpensive polygonal cylindrical core, an advantage can be obtained in that it can be eliminated. Further, the polygonal cylindrical core has the advantage that a shape suitable for accommodating a human body can be selected from among various shapes such as a rectangular cylindrical shape, a hexagonal cylindrical shape, and an encircled cylindrical shape.
第１図は本発明の実施例を示す斜視図、第２図は第１図
の正面図、第６図は実施例の原理的説明図、第４図は実
施例におけるカーレントシートの配置説明図、第５図は
実施例における磁束分布図、第６図は比較例における磁
束分布図、第７図は異なる実施例を示す正面図、第８図
はｍ７図におけるカーレントシート配置説明図、第９図
はさらに異なる実施例を示す正面図、第１０図は第９図
におけるカーレントシート配置説明図、第１１図は他の
実施例を示す正面図、第１２図は第１１図におけるカー
レントシート配置説明図、第１３図は従来技術を示す正
面図、第１４図は改善された従来技術を示す正面図であ
る。
１．２１，３１，４１．５１・・・多角筒状コア、２Ａ
、２Ｂ・・・均一磁場に垂１Ｈな内壁面、２Ｃ，２Ｄ
・・・異なる角度方向の内壁面、２３Ａ、２３Ｂ。
３．５Ａ、４３Ａ、４３Ｂ・・・台形断面を有する板状
の永久磁石、２４Ａ 、２４Ｂ 、２５Ａ 、２５Ｂ
。
３４Ａ、３５Ａ・・・・・・・・不等辺三角形断面を有
する。
板状の永久磁石、２６・・・中空部、１ｏ・・・均一磁
場空間、３０Ｃ，３０Ｄ・・・カーレントシート、１゜
Ｏ・・・均一磁場方向、８−＋ Ｎ・・・磁化の方向、
ｄ・・・台形台面を有する板状の永久磁石の厚み、２７
・・・内壁面の境界線、２８・・・接合面、１０１，１
０２・・・漏れ磁束線、１１０・・・主磁束線。
第２図
第３図
第４図
第７図 第８図
特開昭６２−１７’、’９０３ （８）第１３図
１０、ＯFig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a front view of Fig. 1, Fig. 6 is a diagram explaining the principle of the embodiment, and Fig. 4 is an explanation of the arrangement of the current sheet in the embodiment. Figure 5 is a magnetic flux distribution diagram in the example, Figure 6 is a magnetic flux distribution diagram in a comparative example, Figure 7 is a front view showing a different example, Figure 8 is an explanatory diagram of the current sheet arrangement in the m7 diagram, 9 is a front view showing a further different embodiment, FIG. 10 is an explanatory diagram of the current sheet arrangement in FIG. 9, FIG. 11 is a front view showing another embodiment, and FIG. FIG. 13 is a front view showing a conventional technique, and FIG. 14 is a front view showing an improved conventional technique. 1.21, 31, 41.51... polygonal cylindrical core, 2A
, 2B...inner wall surface 1H perpendicular to the uniform magnetic field, 2C, 2D
...Inner wall surfaces in different angular directions, 23A, 23B. 3.5A, 43A, 43B...Plate-shaped permanent magnet with trapezoidal cross section, 24A, 24B, 25A, 25B
. 34A, 35A...Has a scalene triangular cross section. Plate-shaped permanent magnet, 26...Hollow part, 1o...Uniform magnetic field space, 30C, 30D...Current sheet, 1°O...Uniform magnetic field direction, 8-+N...Magnetization direction,
d...Thickness of a plate-shaped permanent magnet having a trapezoidal trapezoidal surface, 27
... Boundary line of inner wall surface, 28 ... Joint surface, 101,1
02... Leakage magnetic flux line, 110... Main magnetic flux line. Fig. 2 Fig. 3 Fig. 4 Fig. 7 Fig. 8 JP-A-62-17', '903 (8) Fig. 13 Fig. 10, O
Claims (1)
成された軟質磁性材からなるコア、ならびにこのコアの
複数の内壁面を覆うよう固着された複数の永久磁石によ
り、前記コアの内側の中空部に軸線に垂直な一方向の均
一磁場を発生するものであって、台形断面を有する板状
の互いに平行な二面の長辺側の面が前記コアの均一磁場
に垂直な内壁面に固着され前記二面に垂直な方向に磁化
された台形断面を有する板状の永久磁石と、不等辺三角
形断面を有する板状に形成され長辺側の面が前記台形断
面を有する板状の永久磁石とは異なる角度方向の内壁面
に固着され、短辺側の面が隣接する内壁面との境界線を
通る共通の接合面を形成して隣接する永久磁石と接合し
、前記中空部に接する中辺側の面に垂直な方向に磁化さ
れてなる不等辺三角形断面を有する板状の永久磁石との
うち少くともいずれか一方を備えたことを特徴とする永
久磁石形均一磁場マグネット。 ２）特許請求の範囲第１項記載のものにおいて、隣接す
る内壁面の境界線を通る共通の接合面が台形断面を有す
る板状の永久磁石の傾斜面と不等辺三角形断面を有する
板状の永久磁石の短辺側の面とからなり、前記接合面の
中空部側の端が不等辺三角形断面を有する板状の永久磁
石の長辺側および中辺側の交点と、前記境界線を中心と
し台形断面を有する板状の永久磁石の厚みを半径とする
円周上とを結ぶ接線上に位置することを特徴とする永久
磁石形均一磁場マグネット。 ３）特許請求の範囲第１項記載のものにおいて、コアが
菱形筒状に形成され、二つの不等辺三角形断面を有する
板状の永久磁石の短辺側の面からなる共通の接合面と均
一磁場の方向とが前記菱形筒状のコアの対角線に平行に
なるよう形成されたことを特徴とする永久磁石形均一磁
場マグネット。[Claims] 1) A polygonal cylindrical core made of a soft magnetic material having a plurality of pairs of inner wall surfaces parallel to each other, and a plurality of permanent magnets fixed to cover the plurality of inner wall surfaces of this core. This generates a uniform magnetic field in one direction perpendicular to the axis in the hollow part inside the core, and the long side surfaces of the two mutually parallel plate-shaped surfaces having a trapezoidal cross section are the uniform magnetic field of the core. a plate-shaped permanent magnet having a trapezoidal cross section that is fixed to an inner wall surface perpendicular to the magnetic field and magnetized in a direction perpendicular to the two surfaces; and a plate-shaped permanent magnet having a scalene triangular cross section, the long side of which has the trapezoidal shape. A plate-shaped permanent magnet with a cross section is fixed to an inner wall surface in a different angular direction, and the short side surface forms a common joint surface passing through the boundary line with the adjacent inner wall surface and joins with the adjacent permanent magnet. and a plate-shaped permanent magnet having a scalene triangular cross section that is magnetized in a direction perpendicular to the middle side surface in contact with the hollow part. Uniform magnetic field magnet. 2) In the item described in claim 1, the common joint surface passing through the boundary line of the adjacent inner wall surfaces includes an inclined surface of a plate-shaped permanent magnet having a trapezoidal cross section and a plate-shaped permanent magnet having a scalene triangular cross section. and the short side surface of a permanent magnet, and the end of the joint surface on the hollow side has a scalene triangular cross section. A permanent magnet type uniform magnetic field magnet characterized by being located on a tangent line connecting a circumference having a radius equal to the thickness of a plate-shaped permanent magnet having a trapezoidal cross section. 3) In the item described in claim 1, the core is formed in a rhombic cylindrical shape, and is uniform with a common joint surface consisting of the shorter side surfaces of two plate-shaped permanent magnets having scalene triangular cross sections. A permanent magnet type uniform magnetic field magnet, characterized in that the direction of the magnetic field is parallel to the diagonal line of the rhombic cylindrical core.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61019326A JPH079845B2 (en) | 1986-01-31 | 1986-01-31 | Permanent magnet type uniform magnetic field magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61019326A JPH079845B2 (en) | 1986-01-31 | 1986-01-31 | Permanent magnet type uniform magnetic field magnet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62177903A true JPS62177903A (en) | 1987-08-04 |
| JPH079845B2 JPH079845B2 (en) | 1995-02-01 |
Family
ID=11996282
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61019326A Expired - Lifetime JPH079845B2 (en) | 1986-01-31 | 1986-01-31 | Permanent magnet type uniform magnetic field magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH079845B2 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4912445A (en) * | 1988-01-22 | 1990-03-27 | Mitsubishi Denki Kabushiki Kaisha | Electromagnet with a magnetic shield |
| US4998976A (en) * | 1987-10-07 | 1991-03-12 | Uri Rapoport | Permanent magnet arrangement |
| WO1991013449A1 (en) * | 1990-02-22 | 1991-09-05 | Esaote Biomedica, S.P.A. | Terminations of cylindrical permanent magnets |
| US5063934A (en) * | 1987-10-07 | 1991-11-12 | Advanced Techtronics, Inc. | Permanent magnet arrangement |
| WO1993018707A1 (en) * | 1992-03-18 | 1993-09-30 | Sumitomo Special Metals Company Limited | Magnetic field generator for mri |
| US5280209A (en) * | 1989-11-14 | 1994-01-18 | The United States Of America As Represented By The Secretary Of The Army | Permanent magnet structure for use in electric machinery |
| US5334966A (en) * | 1991-12-05 | 1994-08-02 | Hitachi Medical Corp. | Magnetostatic field generator for magnetic resonance imaging apparatus |
| EP0660129A1 (en) * | 1993-12-27 | 1995-06-28 | Sumitomo Special Metals Company Limited | Magnetic field generating apparatus for use in MRI |
| JP2006511921A (en) * | 2002-12-18 | 2006-04-06 | バリアン・インコーポレイテッド | Magnet assembly for sputter ion pump |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58193557U (en) * | 1982-06-18 | 1983-12-23 | 三菱製鋼磁材株式会社 | Magnet device for ion pump |
| JPS60166110U (en) * | 1984-04-11 | 1985-11-05 | 住友特殊金属株式会社 | magnetic field generator |
-
1986
- 1986-01-31 JP JP61019326A patent/JPH079845B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58193557U (en) * | 1982-06-18 | 1983-12-23 | 三菱製鋼磁材株式会社 | Magnet device for ion pump |
| JPS60166110U (en) * | 1984-04-11 | 1985-11-05 | 住友特殊金属株式会社 | magnetic field generator |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4998976A (en) * | 1987-10-07 | 1991-03-12 | Uri Rapoport | Permanent magnet arrangement |
| US5063934A (en) * | 1987-10-07 | 1991-11-12 | Advanced Techtronics, Inc. | Permanent magnet arrangement |
| US4912445A (en) * | 1988-01-22 | 1990-03-27 | Mitsubishi Denki Kabushiki Kaisha | Electromagnet with a magnetic shield |
| US5280209A (en) * | 1989-11-14 | 1994-01-18 | The United States Of America As Represented By The Secretary Of The Army | Permanent magnet structure for use in electric machinery |
| WO1991013449A1 (en) * | 1990-02-22 | 1991-09-05 | Esaote Biomedica, S.P.A. | Terminations of cylindrical permanent magnets |
| US5162770A (en) * | 1990-02-22 | 1992-11-10 | Esaote Biomedica | Terminations of cylindrical permanent magnets |
| US5334966A (en) * | 1991-12-05 | 1994-08-02 | Hitachi Medical Corp. | Magnetostatic field generator for magnetic resonance imaging apparatus |
| WO1993018707A1 (en) * | 1992-03-18 | 1993-09-30 | Sumitomo Special Metals Company Limited | Magnetic field generator for mri |
| EP0660129A1 (en) * | 1993-12-27 | 1995-06-28 | Sumitomo Special Metals Company Limited | Magnetic field generating apparatus for use in MRI |
| JP2006511921A (en) * | 2002-12-18 | 2006-04-06 | バリアン・インコーポレイテッド | Magnet assembly for sputter ion pump |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH079845B2 (en) | 1995-02-01 |
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