JPS60241743A - Core for flat motor and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a core having the prescribed characteristics without waste of a material by forming a blank added with the prescribed compressing margin at an arm portion of an iron sintered alloy, and densifying the arm to the prescribed sintering density. CONSTITUTION:A plurality of arms 2 are projected toward the center from a ring-shaped body 1 which operates as a function of a yoke and toothed poles 3 are formed at the end of a core. Coils 4 are mounted on the arm portions of the arms 2. The arm portions are formed thinly to be contained as the entire coil in the core. The core is made of an iron sintered alloy, the arm portions are densified to the prescribed sintering density to enhance the magnetic flux density of the portion higher than the pole. Thus, the core having the prescribed shape and characteristics is manufactured without waste of a material.

Description

【発明の詳細な説明】 この発明は、Ｖ　−ｒ　Ｒとかステッピングモーターそ
の他に賞用されている偏平モーター用に好適な鉄心に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an iron core suitable for flat motors such as V-rR and stepping motors.

偏平モーターの鉄心は一般に第１図に例示したような平
面形状で、継鉄として機能するリング状の本体１から複
数本のアーム２が中心に向けて突き出し、その先端には
通常歯形状の磁極３が形成されている。The iron core of a flat motor generally has a planar shape as shown in Fig. 1, with a plurality of arms 2 protruding toward the center from a ring-shaped main body 1 that functions as a yoke, and the tips of the arms 2 usually have tooth-shaped magnetic poles. 3 is formed.

鉄心の各アーム部にコイル４を巻線した固定子と、これ
と同軸の回転子（図示せず）でモーターの主要部が構成
される。第２図はコイル４を装盾した状態の縦断面を示
したものである。The main parts of the motor are composed of a stator in which a coil 4 is wound around each arm of an iron core, and a rotor (not shown) coaxial with the stator. FIG. 2 shows a longitudinal section of the coil 4 in a shielded state.

さて、鉄心がほぼ円板状の形なので、第２図における縦
方向の長さを「厚さＪと呼ぶことにすると、図のように
本体部、アーム部、磁極部ともに厚さが等しい場合、ア
ーム部に巻かれたコイルの厚さだけ、固定子全体の厚さ
が当然に増加づる。Now, since the iron core is approximately disk-shaped, the length in the vertical direction in Fig. 2 is called "thickness J." If the thickness of the main body, arm, and magnetic pole is equal as shown in the figure, Naturally, the thickness of the entire stator increases by the thickness of the coil wound around the arm.

しかし、厚さの増加は少しでも薄くする必要がある偏平
モーターにとっては大きな欠点であり、第３図のように
アーム部を薄くしてコイル全体を鉄心内に納めることが
できれば好都合であるが、それには次の問題を克服しな
ければならない。However, the increase in thickness is a major drawback for flat motors that need to be made as thin as possible, and it would be advantageous if the arm part could be made thinner and the entire coil could be housed within the iron core as shown in Figure 3. To do so, the following problems must be overcome.

即ち、磁極３から回転子に作用する磁力の強さはコイル
４が巻線されるアーム２の断面積とその部分の磁束密度
との積に比例するので、第２図の形状で必要十分な特性
を示すよう設計されている場合にそのアーム部を第３図
の如く薄くすると、必要な磁力が得られないことになる
。That is, the strength of the magnetic force acting on the rotor from the magnetic poles 3 is proportional to the product of the cross-sectional area of the arm 2 around which the coil 4 is wound and the magnetic flux density of that part, so the shape shown in Fig. 2 is necessary and sufficient. If the arm portion is designed to exhibit certain characteristics and is made thin as shown in FIG. 3, the necessary magnetic force will not be obtained.

また一方、アーム部が薄くても間に合うだけに磁束密度
の大きい高級材料を用いる場合は、本体部および磁極部
にコイル４の保護には役立つが、鉄心としての特性面で
は余分な材料が浪費されることになる。なお第２図の形
状の素材を切削して第３図の形状に加工する場合は、切
粉になる分も無駄になる訳である。On the other hand, if a high-quality material with a high magnetic flux density is used for the main body and the magnetic pole part even if the arm part is thin, it will be useful for protecting the coil 4, but in terms of the characteristics of the iron core, excess material will be wasted. That will happen. Note that when cutting a material having the shape shown in FIG. 2 and processing it into the shape shown in FIG. 3, the amount of cutting chips is also wasted.

これを避けるためアーム部は磁束密度の大きい＋Ａｎｒ
、それ以外の部分は低級材料で製作し接合することも考
えられるが、材料費の節減よりも複数の部材を接合する
工数と費用の方が高くつき、工業的には得策でない。To avoid this, the arm part has a large magnetic flux density +Anr.
It is conceivable to manufacture the other parts using lower-grade materials and join them together, but the man-hours and costs of joining multiple parts will be higher than the savings in material costs, so this is not an industrially advantageous idea.

さて、一般の溶製材ど異なり、焼結合金は焼結後の再圧
縮により全体または部分的に緻密化（ることができ、ま
た鉄系焼結合金を鉄心に用いた場合、その磁束密度は焼
結密度と一定の関係にあることも知られている。Now, unlike general molten materials, sintered alloys can be densified in whole or in part by recompression after sintering, and when iron-based sintered alloys are used for the iron core, the magnetic flux density is It is also known that there is a certain relationship with sintered density.

発明者らは、この現象を鉄心に応用するという発想によ
ってこの発明に到達したものであって、即ちこの発明は
、鉄心所定の形状と類似形でそのアーム部に所要の圧縮
代が付加された素材を鉄系焼結合金で作り、アーム部を
所定の焼結密度まで緻密化してその部分の磁束密億を磁
極の部分より＾めることを骨子とし、それにより所要の
形状と特性をもつ鉄心を材料の無駄なしに、しかも粉末
冶金の通常の工程に再圧縮工程を追加（るだけで製造可
能にしたものである。The inventors arrived at this invention based on the idea of applying this phenomenon to an iron core.In other words, this invention is based on the idea of applying this phenomenon to an iron core.In other words, this invention has a shape similar to a predetermined shape of an iron core, and a required compression allowance is added to its arm portion. The main idea is to make the material from iron-based sintered alloy, densify the arm part to a predetermined sintering density, and increase the magnetic flux density in that part from the magnetic pole part, thereby achieving the required shape and characteristics. The iron core can be manufactured without wasting material by simply adding a recompression process to the normal powder metallurgy process.

さて、磁極部の磁束密度を８．磁極の端面面積をＡとし
、アーム部の磁束密度をＢ′、断面積をＡ′とするとぎ
、前述の無駄を避けるための必要十分条件は Ａ　−ＢＡＡ’　・Ｂ′・・・・・・・・・■である。Now, the magnetic flux density of the magnetic pole part is 8. Assuming that the end surface area of the magnetic pole is A, the magnetic flux density of the arm part is B', and the cross-sectional area is A', the necessary and sufficient conditions to avoid the above waste are A - BAA'・B'... ...■.

そして焼結合金の磁束密度と焼結密度りとの間には第３
図の如く Ｂ＝にＤ・・・・・・・・・・・・・・・・・・■の関
係があるので、■、■から式■が導かれる。There is a third difference between the magnetic flux density of the sintered alloy and the sintered density.
As shown in the figure, there is a relationship between B= and D・・・・・・・・・・・・■, so the equation ■ can be derived from ■ and ■.

Ａ・にＤ≦Ａ′　・にＤ′ Ｄ′≧△／Ａ’　・Ｄ・・・・・・■ ところで、磁極３の形状および端面面槓、鉄心本体の厚
さおよび」イル４の厚さなどはモーターの基本設計から
与えられるので、アーム部の厚さも自ずと定まり、それ
に対応して磁束密度Ｂ′の目ｅｆｔ　ｌａ　、および式
■から焼結密度Ｄ′が定まる。A・D≦A′・D′ D′≧△/A′・D・・・・・・■ By the way, the shape of the magnetic pole 3, the end face ram, the thickness of the core body, and the thickness of the coil 4 Since these are given from the basic design of the motor, the thickness of the arm portion is also determined naturally, and correspondingly, the sintering density D' is determined from the magnetic flux density B', eft la , and the equation (2).

次に当初の焼結密度りについては、クラックの発生なし
に再圧縮できる最大加工率が材質ごとに存在するので、
その限界内で且つ式■を満足するようＤの値を定める。Next, regarding the initial sintered density, there is a maximum processing rate for each material that can be recompressed without cracking.
The value of D is determined so that it is within the limits and satisfies the formula (2).

この際必要に応じてアーム部の横幅を加減し、断面ＭＡ
’を補正することができる。かくしてＤとＤ′が定まれ
ば、アーム部の厚さに予め付加すべき圧縮代が算出され
る。At this time, adjust the width of the arm part as necessary, and
' can be corrected. Once D and D' are determined in this way, the compression allowance to be added to the thickness of the arm portion in advance is calculated.

なお、この明細書では、粉末冶金用語の一コイニング、
冷間および熱間の鍛造などを「再圧縮」と総称している
。In addition, in this specification, the powder metallurgy terms 1 coining,
Cold and hot forging are collectively referred to as "recompression."

実施例 対象となる鉄心には第１図Ｊ５よび第３図の形状で、本
体の厚さ７ｕ＋、磁極の厚さ６１１１１１（端面面積２
４＋ａｊ）　、　７−ム０）Ｎｃ　ａ２＋１１１　（ｌ
Ｉｉ面ｌ　１６−）のものを選択した。この鉄心の磁極
部３に必要な磁束密度＜８２５）の設計値は１０ｋＧで
ある。The core used in the example has the shapes shown in Figure 1 J5 and Figure 3, with a body thickness of 7u+ and a magnetic pole thickness of 611111 (end surface area 2).
4+aj), 7-mu0)Nc a2+111 (l
Ii side l 16-) was selected. The design value of the magnetic flux density <825) required for the magnetic pole portion 3 of this iron core is 10 kG.

そこで、純鉄とＦｃ−０，６％Ｐの２種類をこの鉄心の
候補とし、それぞれの焼結密度と磁束密度との関係をめ
た。その結果を第４図のグラノに示す。Therefore, two types of iron cores, pure iron and Fc-0.6%P, were selected as candidates for this core, and the relationship between the sintering density and magnetic flux density of each was determined. The results are shown in the graph of FIG.

さて、この鉄心のノアーム部２にｄ３ける磁束密度Ｂ′
の適正値は、式■に△−２４，△’　−１６゜８＝１０
ｋＧを代入して得られる［３′≧１ｂｋＧである。この
値は、第４図に明らかなように純鉄よりＦｅ−０，６％
Ｐ材の方が（ｑや寸く、この材料を焼結密度７．５１１
／ｃ＋ａまで緻密化寸れば得られることがわかる。Now, the magnetic flux density B′ at d3 in the no-arm part 2 of this iron core
The appropriate value for is △-24, △'-16°8=10 in the formula
[3'≧1bkG] obtained by substituting kG. As shown in Figure 4, this value is higher than pure iron by Fe-0.6%.
P material has a sintered density of 7.511
It can be seen that this can be obtained by densification up to /c+a.

この磁束密度（１０ｋＧ）は６．８（１／ｃａの焼結密
度で十分得られるが、製造上の余裕をもたせて系材の焼
結密度を７．ＯＱ／ｃＩＩｉに設定し７％、　６また、
磁権の厚さ６１Ｉｌｌに対してパンチで型出しぐぎる段
差が上下各々０．３Ｉｌｌ程度なので、素材におけるア
ーム部の厚さを５．４ｍｍに、従って横幅を３．２Ｉｌ
＋１に設定した。This magnetic flux density (10kG) can be sufficiently obtained with a sintered density of 6.8 (1/ca, but to allow for manufacturing margin, the sintered density of the system material is set to 7.OQ/cIIi, 7%, 6. Also,
The thickness of the magnet is 61 Ill, and the steps required to punch out the mold are about 0.3 Ill each on the top and bottom, so the thickness of the arm part of the material is 5.4 mm, and the width is therefore 3.2 Ill.
I set it to +1.

この素材のアーム部を製品所定の横幅５ｉｉまで塑性変
形させる際、焼結密度は変化しないと仮定すればぞの厚
さは３．４５１ａｍとなり、その場合の縦方向の加工率
は３６％どなるが、これはこの材料にとって、容易に加
工できる範囲内の値である。When the arm part of this material is plastically deformed to the product's specified width of 5ii, assuming that the sintered density does not change, the thickness of the arm will be 3.451 am, and the processing rate in the vertical direction will be 36%. , which is within the range that can be easily processed for this material.

ただし実際は厚さが３．２１まで圧縮され、その分だけ
密度が上昇する訳である。However, in reality, the thickness is compressed to 3.21, and the density increases by that amount.

重量化で０６％のリンを含む鉄粉を成形金型に入れて第
１図および第３図の形状で本体部の厚さ７ｖｉ、ｆａ極
の厚さ６１１１１．７−ムの厚さ５．４ｍｍ、幅３．２
１１１０に成形したのち、水素雰囲気中１１５０℃で１
時間焼結して焼結密度７．０（Ｊ／ｃａの素材を製作し
た。Iron powder containing 0.6% phosphorus by weight was put into a mold and formed into a mold having the shape shown in FIGS. 1 and 3, with a main body thickness of 7vi and a fa pole thickness of 61111.7mm. 4mm, width 3.2
1110 and then molded at 1150°C in a hydrogen atmosphere.
A material with a sintered density of 7.0 (J/ca) was produced by sintering for hours.

次に、この素材を鍛造金型に入れてアーム部にのみ冷間
鍛造を施して、アーム部の横幅を５１１１１１に拡張す
ると同時に厚さを３．２１１１１１．：　Ｈ縮して所要
の鉄心に仕上げた。鍛造後の鉄心からアーム部を切り出
して部分密度を調べた結果、７．５３Ｑ／ｃ−の実測値
が得られた。Next, this material is placed in a forging die and cold forging is performed only on the arm portion, expanding the width of the arm portion to 511111 mm and simultaneously reducing the thickness to 3.211111 mm. : H-shrinked and finished into the required iron core. As a result of cutting out the arm portion from the forged iron core and examining the partial density, an actual value of 7.53Q/c- was obtained.

この鉄心を用いたモーターの特１／Ｉ試験を行なった結
果設計通りの回転トルクが得られ、この発明が所期の効
果を奏覆ることが確認された。As a result of conducting a special 1/I test on a motor using this iron core, the rotational torque as designed was obtained, and it was confirmed that this invention achieved the desired effect.

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

第１図は鉄心の平面形状を例示Ｊる図面、第２図は本体
部および磁極部とアーム部の厚さが一様な鉄心の縦断面
図、第３図はこの発明が意図する断面形状の、アームの
厚さをコイルの分だけ幼くした鉄心の縦断面図、第４図
は鉄系焼結合金の焼結密度と磁束密度との関係を示すグ
ラフである。 １・・・鉄心の本体　２・・・アーム ３・・・磁　ｔｉ　４・・・コイル 代理人　増　渕　邦　彦 第１図 第４図 焼結密度Ｄ（９／ＣＴＩＩ３）Fig. 1 is a drawing illustrating the planar shape of the iron core, Fig. 2 is a longitudinal cross-sectional view of the iron core in which the main body, magnetic pole parts, and arm parts have uniform thicknesses, and Fig. 3 is the cross-sectional shape intended by the present invention. FIG. 4 is a longitudinal cross-sectional view of an iron core in which the thickness of the arm is reduced by the thickness of the coil. FIG. 4 is a graph showing the relationship between the sintered density and magnetic flux density of the iron-based sintered alloy. 1... Main body of iron core 2... Arm 3... Magnetic ti 4... Coil agent Kunihiko Masubuchi Figure 1 Figure 4 Sintered density D (9/CTII3)

Claims (1)

【特許請求の範囲】 １　リング状の本体１から複数本のアーム２が中心に向
けて突き出し、各アームの先端に！１１４３が形成され
、且つ各アームに巻線されるコイル４の厚さだけアーム
２の厚さが薄い形状の鉄心において、この鉄心が鉄系焼
結合金からなり、且つ磁極部の焼結密度よりもアーム部
の焼結密度が所定の割合で高いことを特徴とする、磁極
部とアーム部の磁束密度が異なる偏平モーター用鉄心。 ２　リング状の本体１から複数本のアーム２が中心に向
（ブて突き出し、各アームの先端に磁極３が形成され、
且つ各アームに巻線されるコイル４の厚さだけアーム２
の厚さが薄い鉄心を製造するに際し、この鉄心と類似形
でアーム部の厚さに所定の圧縮代を付加した素材を鉄系
焼結合金で作り、次いでこの素材のアーム部を所定の厚
さまで圧縮すると同時にアーム部を所定の焼結密度まで
緻密化することを特徴とする、磁極部とアーム部の磁束
密度が異なる偏平モーター用鉄心の製造法。[Claims] 1. A plurality of arms 2 protrude toward the center from the ring-shaped main body 1, and at the tip of each arm! 1143 is formed, and the arm 2 is thinner by the thickness of the coil 4 wound around each arm, this iron core is made of a ferrous sintered alloy, and has a sintered density lower than that of the magnetic pole part. A flat iron core for a flat motor in which the magnetic flux densities of the magnetic pole part and the arm part are different, characterized in that the sintered density of the arm part is high at a predetermined ratio. 2 A plurality of arms 2 protrude toward the center from a ring-shaped main body 1, and a magnetic pole 3 is formed at the tip of each arm.
In addition, the arm 2 has a thickness equal to the thickness of the coil 4 wound on each arm.
When manufacturing an iron core with a thin thickness, a material similar to this iron core with a predetermined compression allowance added to the thickness of the arm part is made from iron-based sintered alloy, and then the arm part of this material is made with a predetermined thickness. A method of manufacturing a flat iron core for a flat motor, characterized in that the arm part is densified to a predetermined sintering density at the same time as the magnetic pole part and the arm part are compressed.