JPS59152469A - Magnet roll for magnetic brush development - Google Patents

Abstract

PURPOSE:To reduce the weight of a magnet roll by providing concentrically a roll-shaped magnet consisting of a composite ferrite material which has plural magnetic poles on the surface and are arranged radially with ferromagnetic axes with each magnetic pole as a center and excluding a part of the magnetic material. CONSTITUTION:A composite ferrite material mixed with ferrite particles subjected to a magnetic anisotropic treatment and a medium for binding the ferrite particles is used, and ferromagnetic axes are radially arranged with the respective magnetic poles on the roll-shaped surface as a center, by which a roll-shaped magnt 1 is formed and is fixed to a shaft 2. A nonmagnetic cylindrical sleeve 3 is concentrically disposed on the outside of the magnet 1. The magnetic forces of the surface magnetic poles are distributed in such a way that a developing pole 4 requires the largest magnet and that the pole 5 for conveying a toner, a pole 6 for attracting the toner, etc. are given the magnetic force smaller than for the pole 4. A magnetic pole part 7 which is continuous from the roll-shaped outside circumferential surface to the inside circumferential surface and where the magnet material does not exist over the entire region in the axial direction is formed in the part where the small magnetic field is required. The intensity of the magnetic field in the part 7 is adjustable by changing the size A of the excluded part, by which the reduction in the weight of the magnet roll is made possible.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は電子写真やファクシミリ受信機などの磁気ブラ
シ現像用磁石ロールに関するものである○従来例の構成
とその問題点 従来の磁気ブラシ現像用磁石ロールにおけるロール状磁
石の製造方法としては、フェライト粒子を円筒状に一体
成形し、焼結工程を経た後、その外周面に着磁を施した
円筒形の・焼結フェライト磁石を設けるものがよく知ら
れている。[Detailed Description of the Invention] Industrial Application Field The present invention relates to a magnet roll for developing magnetic brushes for electrophotography, facsimile receivers, etc. ○Conventional structure and problems thereof Conventional magnet roll for developing magnetic brushes A well-known method for manufacturing roll-shaped magnets is to integrally mold ferrite particles into a cylindrical shape, undergo a sintering process, and then provide a cylindrical sintered ferrite magnet whose outer peripheral surface is magnetized. It is being

このような方法によって製造されるロール状磁石は、磁
気ブラシ現像用磁石ロールとして、軸方向に継目が無い
ため、現像ムラを生じないという利点があるが、同時に
、円筒状にて一体の焼結１−程が必要なため、焼結条件
にて部分的に収縮率が異なり、一定の寸法のものが得ら
れに＜＜、また工程的にも複雑で、取扱いとしても破損
じやすく歩留りの点でも著しく不利なるという問題があ
った。The rolled magnet manufactured by this method has the advantage that it can be used as a magnet roll for magnetic brush development because there is no seam in the axial direction, so uneven development does not occur. 1), the shrinkage rate varies depending on the sintering conditions, making it difficult to obtain a product with a constant size, and the process is complicated and easily damaged when handled, resulting in poor yield. However, there was a problem that was a significant disadvantage.

さらりここのロール状磁石は、比重が６．０〜６．２と
大きく、ロール状一体成形されているため磁石ロール全
体が重くなるという欠点があった。Sarariko's rolled magnets have a high specific gravity of 6.0 to 6.2, and because they are integrally molded into rolls, they have the disadvantage that the entire magnet roll is heavy.

上記の利点を維持しながら、これらの欠点を除くために
他の従来のロール状磁石の製造法としては、磁気異方性
娠理をしたフェライト粒子と、このフェライト粒子を接
合するゴム系および、合成樹脂を混合した複合フェライ
ト］オ料を使用し、ロール状表面の各磁極を中心（／こ
強磁性軸を放射状に配列させて、強磁力のロール状磁石
としたものが提案されている（％公昭６６−５１４８１
号公報）。In order to eliminate these disadvantages while maintaining the above-mentioned advantages, another conventional method for manufacturing roll magnets is to use ferrite particles with magnetic anisotropy, a rubber system for bonding the ferrite particles, and It has been proposed that a roll-shaped magnet with strong magnetic force is created by using a composite ferrite mixed with synthetic resin and arranging the ferromagnetic axes in a radial manner with each magnetic pole on the roll-shaped surface at the center. % Kosho 66-51481
Publication No.).

そしてその方法により製造された磁気現像用磁（−１０
−ルは第１図に示すように、ロール状磁石１がノヤフト
２に固定されており、磁白１の外側には、非磁性の円筒
状スリーブ３が同心状に配置されて、両端の輔受部（図
示しない）を介して、回転可能に取伺けた構成である。And the magnetic developing magnet (-10
As shown in FIG. 1, a rolled magnet 1 is fixed to a magnet 2, and a non-magnetic cylindrical sleeve 3 is arranged concentrically on the outside of the magnet 1. It is configured to be rotatably accessible via a receiving part (not shown).

そして一般的にロール伏線で１１の表面磁極の磁ノ扮〆
ぽは現像面に対抗した現像極４が最もす（きな磁力を必
ヅと１２、その他トナーの搬送極らち・」：びトナーを
スリーブ３の表面Ｖ（吸着さぜるグこめの吸着極６等は
、現像極４よりも小さな磁力を与えるものである。In general, the magnetic force of the surface magnetic pole 11 in the roll foreshadowing is the greatest at the developing pole 4, which is opposed to the developing surface. The surface V of the sleeve 3 (the suction pole 6 and the like on the surface V of the sleeve 3) provides a smaller magnetic force than the development pole 4.

発明の目的 本発明は、上記ロール状磁石をさらに改善し、さらに軽
量化と低価格化とを達成する磁気ブラ・／現像用磁石ロ
ールを提供するものである。OBJECTS OF THE INVENTION The present invention provides a magnetic bra/developing magnet roll that further improves the roll-shaped magnet described above and achieves further weight reduction and cost reduction.

発明の構成 」＝記目的を達成するために、本発明は表面に複数個の
磁極を有し、その各磁極を中心に、強磁性軸を放射状に
配列した複合フェライト材料からなるロール状磁石を、
円筒形の非磁性スリーブ内に同心状に配置し、隣接する
両磁極より小さな磁石材料を軸方向全域にわたって排除
した構成である。In order to achieve the object described in "Structure of the Invention", the present invention provides a rolled magnet made of a composite ferrite material that has a plurality of magnetic poles on its surface and has ferromagnetic axes arranged radially around each magnetic pole. ,
It is arranged concentrically within a cylindrical non-magnetic sleeve, and has a structure in which magnetic material smaller than both adjacent magnetic poles is excluded throughout the entire axial direction.

磁石材料の排除により大中な軽量化が図れ、また磁石材
ｆ−’ｌの節約にもつながり、低価格の磁石ロールを得
ることができる。By eliminating the magnet material, the weight can be significantly reduced, and the magnet material f-'l can also be saved, making it possible to obtain a low-cost magnet roll.

実施例の説明 以下本発明の一実施例における磁気ブ？シ現像用磁石ロ
ールについて、図面とともに説明する。DESCRIPTION OF EMBODIMENTS Below is a description of a magnetic band in an embodiment of the present invention. The developing magnet roll will be explained with reference to the drawings.

本発明の一実施例における磁気ブラシ現像用磁石ロール
は、第２図に示すように、ロール状外周面から、内周面
に連続し、かつ軸方向全域にわたって、一部磁石材料を
排除することにある。この磁石材料の存在しない磁極部
で磁界の構成を、磁束の１ＡＩＩ’ｌから説明すると、
第３図および第４図シこ示ずように、−・方の隣接する
磁極６から発生する異Ｊ−ｊ向（隣接した磁極の表面が
Ｎ極の場合はＳ極）の磁束８と、もう一方の８接する磁
極９から発生する同様の異方向の磁束１０が、スリーブ
１０表面上においても７７在し、この２つの磁束８，１
０の合成された磁界１１が、この磁極７を構成すること
になる。As shown in FIG. 2, the magnet roll for magnetic brush development in one embodiment of the present invention has a structure in which a portion of the magnet material is removed from the roll-shaped outer circumferential surface, which is continuous with the inner circumferential surface, and over the entire axial direction. It is in. The configuration of the magnetic field at the magnetic pole part where no magnetic material is present is explained from the magnetic flux 1AII'l:
As shown in FIGS. 3 and 4, a magnetic flux 8 in a different J-j direction (or an S pole if the surface of the adjacent magnetic pole is an N pole) generated from the adjacent magnetic poles 6 on the - side, There are 77 similar magnetic fluxes 10 in different directions generated from the other 8 contacting magnetic poles 9 on the surface of the sleeve 10, and these two magnetic fluxes 8, 1
The combined magnetic field 11 of zero constitutes this magnetic pole 7.

／ヤ７１−２　（ｔこ固定した各磁極の磁ｆｉ　Ｉ°Ａ
料は、磁極を中、ｌｊｆ／こ、強磁性軸を放射状に配列
させているたｄ〕、ロール状表面の磁極Ｖこｉｌする異
方向の磁極は扇形の磁極６，９のピースの側面１２に存
７Ｅ　Ｌ、スリーブ外周外での距離が近いため、大きな
磁力を残した１寸、磁束８，１０は図のように流れる。/ya 71-2 (magnetic fi I°A of each fixed magnetic pole
The magnetic poles are arranged in the center, the ferromagnetic axes are arranged radially; Since the distance outside the outer periphery of the sleeve is short, the magnetic fluxes 8 and 10, which have a large magnetic force, flow as shown in the figure.

このようにしてできだ磁極７の磁界の強さは、排除部の
（」′法人によって、第５図のような特性を得ることが
でき、寸法大を小さくすると、両隣接の磁束が集中１〜
、大きな磁束密度を得ることになり、ζ１法Ａを大きく
すると磁束が分散して、磁束密度が小さくなる。The strength of the magnetic field of the magnetic pole 7 created in this way can obtain the characteristics shown in FIG. ~
, a large magnetic flux density is obtained, and when the ζ1 method A is increased, the magnetic flux is dispersed and the magnetic flux density becomes smaller.

したがって、ＮＪ″法人を変化させることにより隣接す
るどちらか強い方の磁極の７０％以内であれば、任意に
規定することが可能になり、その延長として、略零磁界
部を作ることも可能になる。Therefore, by changing the NJ'' corporation, it becomes possible to arbitrarily specify the magnetic field as long as it is within 70% of the stronger of either of the adjacent magnetic poles, and as an extension of this, it is also possible to create a nearly zero magnetic field section. Become.

発明の効果 以上のように本発明は現像極以外の磁極の一部および、
スリーブ表面からトナーを掻き落すための略零磁界部に
おいて、磁石材料を排除しているため、磁石ロールとし
て、大巾な軽量化が達成でき、従来の円筒状一体焼結フ
エライト磁石と比較すると、複合フェライト材料はその
比重が３．５〜３．６と約３０％軽減されているうえに
、さらに磁極分布によっては、約３０％の軽減が可能に
なる。Effects of the Invention As described above, the present invention provides a portion of the magnetic pole other than the developing pole and
Since the magnetic material is not used in the almost zero magnetic field area for scraping toner off the sleeve surface, the weight of the magnetic roll can be significantly reduced, compared to conventional cylindrical integrally sintered ferrite magnets. The specific gravity of the composite ferrite material is reduced by about 30% to 3.5 to 3.6, and depending on the magnetic pole distribution, it is possible to reduce the specific gravity by about 30%.

寸だ磁石相例の節約にもつながり、低価格の磁石ロール
を得ることができるなどの利点を持ち、工業的価値の犬
なるものである。It has advantages such as saving a lot of magnet phase and making it possible to obtain low-priced magnet rolls, making it an industrial value dog.

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

第１図は従来の磁石ロールの断面図、第２図は本発明の
磁石ロールの一実施例を示す断面図、第３図は同要部拡
大断面図、第４図は同スリーブ表面における磁束密度の
円周方向の分布図、第６図は磁極部の排除間隔とその磁
束密度との関係を示す特性図である。 １　・・ロール伏線白、２　・・シャフト、３・・・・
・・円筒状スリーブ、４，５，６．９・・・磁極。 代理人の武名　弁理士　中　尾　敏　男　ほか１名第１
図 第３図 第４図 図 β Ａす沫Fig. 1 is a sectional view of a conventional magnet roll, Fig. 2 is a sectional view showing an embodiment of the magnet roll of the present invention, Fig. 3 is an enlarged sectional view of the same main part, and Fig. 4 is a magnetic flux on the surface of the sleeve. FIG. 6, which is a distribution diagram of the density in the circumferential direction, is a characteristic diagram showing the relationship between the exclusion interval of the magnetic pole portion and its magnetic flux density. 1... Roll foreshadowing white, 2... Shaft, 3...
...Cylindrical sleeve, 4, 5, 6.9...Magnetic pole. Agent Takena Patent Attorney Toshio Nakao and 1 other person 1st
Figure 3 Figure 4 Figure β

Claims (2)

【特許請求の範囲】[Claims] （１）磁気異方性処理をしたフェライト粒子とそのフェ
ライト粒子を接合する媒質とを混合した複合フエライ）
　ｔＪ料からなり、表面に複数個の磁極を有しその各磁
極を中心に強磁性軸を放射状に配列したロール状磁石を
円筒形の非磁性スリーブ内に同心状に配置し、隣接する
」二記両磁極より小さな磁界を必要とする磁極部分の磁
石桐料を軸方向全域にわたって排除した磁気ブラシ現像
用磁石ロール。(1) Composite ferrite made by mixing magnetically anisotropically treated ferrite particles and a medium that bonds the ferrite particles)
A roll-shaped magnet made of TJ material and having a plurality of magnetic poles on its surface and ferromagnetic axes arranged radially around each magnetic pole is arranged concentrically within a cylindrical non-magnetic sleeve. A magnet roll for magnetic brush development in which the magnet material in the magnetic pole part, which requires a smaller magnetic field than both magnetic poles, is eliminated over the entire axial direction. （２）隣接する両磁極のうち、いずれか一方の磁極の７
０％以下の磁束密度を必要とする磁極部分の磁石材料全
排除した特許請求の範囲第１項記載の磁気ブラシ現像用
磁石ロール。(2) 7 of either magnetic pole among both adjacent magnetic poles
The magnetic roll for magnetic brush development according to claim 1, wherein the magnetic material of the magnetic pole portion that requires a magnetic flux density of 0% or less is completely eliminated.