JPS60119703A - Manufacture of permanent magnet for highly uniform magnetic field - Google Patents

Manufacture of permanent magnet for highly uniform magnetic field

Info

Publication number
JPS60119703A
JPS60119703A JP58228050A JP22805083A JPS60119703A JP S60119703 A JPS60119703 A JP S60119703A JP 58228050 A JP58228050 A JP 58228050A JP 22805083 A JP22805083 A JP 22805083A JP S60119703 A JPS60119703 A JP S60119703A
Authority
JP
Japan
Prior art keywords
permanent magnet
magnetic field
notch
highly uniform
dimensions
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.)
Pending
Application number
JP58228050A
Other languages
Japanese (ja)
Inventor
Goji Oku
剛司 奥
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Electric Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Industries Ltd
Priority to JP58228050A priority Critical patent/JPS60119703A/en
Publication of JPS60119703A publication Critical patent/JPS60119703A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/02—Permanent magnets [PM]
    • H01F7/0205—Magnetic circuits with PM in general
    • 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
    • H01F41/0253—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 for manufacturing permanent magnets

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)

Abstract

PURPOSE:To obtain a permanent magnet having a magnetic field of desirable uniformity, by molding magnetic powdcer mixed in resin into a primary cylindrical product having a notch with required tolerance in dimensions and finishing it by machining into desired dimensions. CONSTITUTION:Magnetic powder is mixed in resin, and the mixture is molded to produce a primary cylindrical product having a required notch 7 with some tolerance in the dimensions. The notch is formed on one of the outer or inner periphery of the cylinder so as to have one or two steps. The primary product is thereafter finished by machining into a desired dimensions to complete a permanent magnet 5. According to this constitution, a permanent magnet with a magnetic field of high uniformity can be obtained in conformity with a disign.

Description

【発明の詳細な説明】 （イ）産業上の利用分野 この発明は、核磁気共鳴を利用した機器、例えは、核磁
気共鳴コンピュータ断層写真撮影機器（ＮＭＲ−ＣＴ）
等に使用される高均一磁場用磁石に関するものである。DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention is directed to an apparatus using nuclear magnetic resonance, for example, a nuclear magnetic resonance computed tomography apparatus (NMR-CT).
This relates to magnets for high uniform magnetic fields used in applications such as magnets.

（ロ）従来技術とその問題点 ＮＭＲ−ＣＴに使用されている従来の高均一磁場用磁石
は、常伝導または超電導の電磁石である。(b) Prior art and its problems Conventional highly uniform magnetic field magnets used in NMR-CT are normal or superconducting electromagnets.

常伝導電磁石は、コイル抵抗による発熱があるため冷却
装置を必要とし、また超電導電磁石は、コイルを超電導
状態まで冷却する液体ヘリウムに要するコストが高くつ
くと共にクエンチの問題もある。Normal conducting electromagnets require a cooling device because of the heat generated by the coil resistance, and superconducting electromagnets require high costs for liquid helium to cool the coils to a superconducting state and also have problems with quenching.

また、一般に電磁石の場合は、コイル巻きの精度に限界
があるため、得られる磁場の均一度にも限界があり、そ
の均一度をさらに向−トさせようとすると、補正用の磁
石が必要となる。例えは、第１図に示すような外周一段
ノツチイ」きのソレノイド１について、コイル巻きによ
って形成されるノツチ２のずれが、どの程度磁場の均一
度に影響を及ぼすかについて計算した結果を示したのか
、第２図および第３図である。In addition, in the case of electromagnets, there is generally a limit to the precision of coil winding, so there is a limit to the uniformity of the magnetic field that can be obtained, and if you try to further improve the uniformity, a correction magnet is required. Become. For example, for a solenoid 1 with a single-stage notch on the outer periphery as shown in Fig. 1, the calculation results are shown as to how much the deviation of the notch 2 formed by the coil winding affects the uniformity of the magnetic field. 2 and 3.

第１図のａＮはノツチ２の半径、ｂＮはノツチ２の長さ
の半分を示している。In FIG. 1, aN indicates the radius of the notch 2, and bN indicates half the length of the notch 2.

第２図はａＮを固定し、ｂＮをずらせた場合の磁場。Figure 2 shows the magnetic field when aN is fixed and bN is shifted.

の均一度Ｎを示すものである。縦軸に示した磁場の均一
度へは、 て定義されるものであり、実線はボア３の径×１／２の
範囲、破線はボア３の径×３／１ｏの範囲における均一
度を示す（以下間し）。また、横軸に示したｂＮのプラ
ス、マイナスは、第１図のｂＮの矢印方向・２プラスに
とった場合である。It shows the uniformity N of. The uniformity of the magnetic field shown on the vertical axis is defined as follows, where the solid line indicates the uniformity in the range of the diameter of the bore 3 x 1/2, and the broken line indicates the uniformity in the range of the diameter of the bore 3 x 3/1o. (Below). Further, the positive and negative values of bN shown on the horizontal axis are when bN is taken in the direction of the arrow in FIG.

第３図はｂＮを固定し、ａＮをすらせた場合のＮを示す
ものであり、縦軸は上記と同様、横軸に示したａＮのプ
ラス、マイナスは、第１図のａＮの矢印方向をプラスに
とった場合である。Figure 3 shows N when bN is fixed and aN is slid.The vertical axis is the same as above, and the horizontal axis indicates the plus and minus of aN in the direction of the arrow of aN in Figure 1. This is the case when we take it as a plus.

第２図および第３図かられかるように、ノツチ２の長さ
方向または径方向へのずれが０．１ｍ　あると、均一度
が約１桁以上低下することがわかる。As can be seen from FIGS. 2 and 3, if the notch 2 shifts by 0.1 m in the length direction or radial direction, the uniformity decreases by about one order of magnitude or more.

なお、第４図から第６図は２段のノツチ２，４を設けた
場合について、前記の場合と同様の計算結果であり、ま
た第７図から第９図は１段のノツチ２を内周に形成した
場合である。これらの場合も前記の場合と同様の傾向を
示す。Note that Figures 4 to 6 show the same calculation results as the above case when two stages of notches 2 and 4 are provided, and Figures 7 to 9 show the calculation results when one stage of notches 2 and 4 are provided. This is the case where it is formed around the periphery. These cases also show the same tendency as the above case.

（ハ）問題点を解決するための手段 上記の問題点を解決し、磁場の均一度の精度を向上させ
るために、この発明は、磁性粉を樹脂に混合して円筒形
ノツチ付の一次製品を所要の余裕寸法をもって成形し、
成形後機械加工により所要寸法に仕上けることにより永
久磁石を製造するようにしたものである。(c) Means for Solving the Problems In order to solve the above problems and improve the accuracy of the uniformity of the magnetic field, the present invention has developed a primary product with cylindrical notches by mixing magnetic powder with resin. is formed with the required allowance dimensions,
Permanent magnets are manufactured by machining after molding and finishing to the required dimensions.

に）実施例 第１０図はこの発明の実施によって製造される永久磁石
５を示している。この場合は、所要径のボ１アロを有し
、外周に１段のノツチ７を形成したものであるが、これ
以外に先に第４図、第７図で示したソレノイド１と同様
外周に２段のノツチを形成する場合、内周に１段または
２段のノツチを形成する場合がある。B) Embodiment FIG. 10 shows a permanent magnet 5 manufactured by carrying out the present invention. In this case, it has a bore of the required diameter and a single stage notch 7 on the outer periphery. When forming two notches, one or two notches may be formed on the inner periphery.

これらの永久磁石５は、磁性粉を樹脂に混合して接着成
形され、多少の余裕寸法（第１０図の一点鎖線参照）を
もって所要のノツチ７を有する円筒形の一次製品として
製造され、そ′の後機械加工により所要の設計寸法に仕
上げる。These permanent magnets 5 are manufactured as cylindrical primary products by mixing magnetic powder with resin and adhesively molding them, and having the required notches 7 with some allowance (see the dashed line in Fig. 10). After that, it is finished to the required design dimensions by machining.

機械加工により仕上げると、各部の寸法、特にノツチ７
の寸法を０．０１＋ｍｎ程度の誤差の範囲に抑えること
ができ、設計どおりの形状のものを得ることができる。When finished by machining, the dimensions of each part, especially notch 7.
It is possible to suppress the dimensions to within an error range of approximately 0.01+mn, and it is possible to obtain a product having the shape as designed.

したがって、第２．３．５．６．７および８図でわかる
ように、設計どおりの高均一度磁場をもった永久磁石が
得られる。Therefore, as can be seen in Figures 2.3.5.6.7 and 8, a permanent magnet with a highly uniform magnetic field as designed can be obtained.

（ホ）　効　宋 以−上述へたように　この発明は磁性粉を樹脂で固める
ことにより成形した永久磁石を機械加工により仕」二げ
ることによって製造することができるものであるため、
磁場分布をより広い範囲で高均一に保つことができる効
果がある。(e) Effects Since the Song Dynasty - As mentioned above, this invention can be manufactured by machining a permanent magnet formed by solidifying magnetic powder with resin.
This has the effect of keeping the magnetic field distribution highly uniform over a wider range.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図、第４図および第７図は従来のソレノイドの断面
図、第２図と第３図は第１図の場合、第５図と第６図は
第４図の場合、第８図と第９図は第７図の場合のそれぞ
れノツチのずれと磁場の均一度の関係を示すグラフ、第
１０図はこの発明の実施例の断面図である。 ５・・・永久磁石、６・・・ボア、７・・・ノツチ。 特許出願人　住友電気工業株式会社 同　代理人　鎌　１）文　二 第２図 第５図 第３図 第６図 −ｂ２のすわ 第８図 第１０図 第９図 ＋ａＮのすＪ１Figures 1, 4 and 7 are cross-sectional views of conventional solenoids, Figures 2 and 3 are for Figure 1, Figures 5 and 6 are for Figure 4, and Figure 8 is for Figure 4. and FIG. 9 are graphs showing the relationship between the notch deviation and the uniformity of the magnetic field in the case of FIG. 7, and FIG. 10 is a cross-sectional view of an embodiment of the present invention. 5...Permanent magnet, 6...Bore, 7...Notch. Patent Applicant: Sumitomo Electric Industries, Ltd. Agent: Kama 1) Text 2 Figure 2 Figure 5 Figure 3 Figure 6 - b2 Nosuwa Figure 8 Figure 10 Figure 9 + aN Nosu J1

Claims (1)

【特許請求の範囲】 （１）磁性粉を樹脂に混合して円筒形ノツチ付の一次製
品を所要の余裕寸法をもって成形し、成形後機械加工に
より所要寸法に仕上けることを特徴とする高均一磁場用
永久磁石の製造方法。 ＋２＋　−１＝記のノツチを、円筒の外周または内周の
いずれか一方に形成することを特徴とする特許請求の範
囲第１項に記載の高均一磁場用永久磁石の製造方法。 （３）に記の７ツチが１段式または２段式であることを
特徴とする特許請求の範囲第１項または第２項に記載の
高均一磁場用永久磁石の製造方法。[Claims] (1) A highly uniform method characterized by mixing magnetic powder with resin, molding a primary product with a cylindrical notch with the required margin dimensions, and finishing the required dimensions by machining after molding. A method of manufacturing a permanent magnet for magnetic fields. The method of manufacturing a permanent magnet for a highly uniform magnetic field according to claim 1, characterized in that the notch described in +2+ -1= is formed on either the outer periphery or the inner periphery of the cylinder. The method for manufacturing a permanent magnet for a highly uniform magnetic field according to claim 1 or 2, wherein the seven elements described in (3) are one-stage type or two-stage type.
JP58228050A 1983-11-30 1983-11-30 Manufacture of permanent magnet for highly uniform magnetic field Pending JPS60119703A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP58228050A JPS60119703A (en) 1983-11-30 1983-11-30 Manufacture of permanent magnet for highly uniform magnetic field

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP58228050A JPS60119703A (en) 1983-11-30 1983-11-30 Manufacture of permanent magnet for highly uniform magnetic field

Publications (1)

Publication Number Publication Date
JPS60119703A true JPS60119703A (en) 1985-06-27

Family

ID=16870413

Family Applications (1)

Application Number Title Priority Date Filing Date
JP58228050A Pending JPS60119703A (en) 1983-11-30 1983-11-30 Manufacture of permanent magnet for highly uniform magnetic field

Country Status (1)

Country Link
JP (1) JPS60119703A (en)

Similar Documents

Publication Publication Date Title
US5229723A (en) Magnetic field generating device for mri
US4678616A (en) Method of producing permanent magnet
CN107017082B (en) Three-phase reactor, motor drive device, power conditioner, and machine
KR102410836B1 (en) Dipole ring magnetic field generator
JPH03501076A (en) Electromagnet and its manufacturing method
US20200064424A1 (en) Permanent magnet arrangement for generating a homogeneous field ("3d halbach")
US5034715A (en) Permanent magnet field sources of conical orientation
US5028902A (en) Permanent magnet field sources of radial orientation
JPH0378592B2 (en)
EP2450918B1 (en) Dipole-ring magnetic circuit
USH591H (en) Method of manufacturing of a magic ring
EP0092440B1 (en) Magnet roller
US5075662A (en) Enhanced magnetic field within enclosed annular cavity
JPS60119703A (en) Manufacture of permanent magnet for highly uniform magnetic field
US5666097A (en) Periodic magnetizer
US6525633B1 (en) Radial periodic magnetization of a rotor
JPS58219705A (en) Anisotropic ring polymer magnet and apparatus for manufacturing the same
JPS6028377B2 (en) Manufacturing method for rolled magnets
JPS621208A (en) Shell type multipolar superconducting magnet
US7232495B2 (en) Method of magnetizing rare-earth magnet and rare-earth magnet
JPS55165608A (en) Method and apparatus for manufacturing anisotropic magnet
JPH06124822A (en) R-tm-b group anisotropic ring magnet and its manufacture
JPH03141619A (en) Magnet for generating magnetic field uniform in wide region
JPH0556644B2 (en)
JPH06330103A (en) Die for compacting magnetic powder