JP3039021B2 - Manufacturing method of rotary transformer - Google Patents
Manufacturing method of rotary transformerInfo
- Publication number
- JP3039021B2 JP3039021B2 JP3202841A JP20284191A JP3039021B2 JP 3039021 B2 JP3039021 B2 JP 3039021B2 JP 3202841 A JP3202841 A JP 3202841A JP 20284191 A JP20284191 A JP 20284191A JP 3039021 B2 JP3039021 B2 JP 3039021B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- rotary transformer
- core
- coil
- cylindrical
- 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.)
- Expired - Fee Related
Links
Description
【０００１】[0001]
【産業上の利用分野】本発明はビデオテープレコーダや
デジタルオーディオテープレコーダなどの回転する磁気
ヘッドに対する信号の授受に用いるロータリートランス
の製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a rotary transformer for transmitting and receiving signals to and from a rotating magnetic head such as a video tape recorder and a digital audio tape recorder.
【０００２】[0002]
【従来の技術】ビデオテープレコーダやデジタルオーデ
ィオテープレコーダなどの磁気記録再生機器に使用され
るロータリートランスには円板型と円筒型の２種類があ
るが、近年、機器の高性能化，多機能化に伴い必要とさ
れるチャンネル数の増加と高密度化によって、円筒型ロ
ータリートランスの使用が増えてきた。このロータリー
トランスの構造は円筒型のフェライトからなる内側コア
とフェライトからなる外側コアの両者が同軸に相対向し
て一定の極小間隙を保たれて配置されており、対向する
それぞれの表面には必要とするチャンネル数のコイル用
凹溝が設けられ、そのコイル用凹溝内にコイルが装着さ
れている。また内側コアの各チャンネル間にはショート
リングをはめこむ凹溝が設けてある。2. Description of the Related Art There are two types of rotary transformers used in magnetic recording / reproducing devices such as video tape recorders and digital audio tape recorders, disc type and cylindrical type. The use of cylindrical rotary transformers has been increasing due to the increase in the number of channels required and the increase in density with the development. In this rotary transformer, the inner core made of cylindrical ferrite and the outer core made of ferrite are coaxially opposed to each other with a certain minimum gap between them. The number of channels for the coil is set as follows, and the coil is mounted in the groove for the coil. In addition, a concave groove is provided between each channel of the inner core to receive a short ring.
【０００３】上記構成のロータリートランスにおいて
は、記録再生信号電流の損失を極力少なくする上で回転
に支障をきたさない限り、内側コアと外側コアの相対向
間隙は狭ければ狭いほど好ましい。実際には７０μｍ以
下という極めて高精度の間隙量が要求されている。この
要求を満たすためには、各々の内側コア，外側コアの特
に対向面となる表面粗度，真円度，同軸度さらには組立
て精度を正確に制御しなければならない。[0003] In the rotary transformer having the above configuration, it is preferable that the opposing gap between the inner core and the outer core is as narrow as possible, as long as the rotation is not hindered in minimizing the loss of the recording / reproducing signal current. In practice, an extremely accurate gap amount of 70 μm or less is required. In order to satisfy this requirement, it is necessary to precisely control the surface roughness, roundness, coaxiality, and assembling accuracy of the inner core and the outer core, particularly, the opposing surfaces.
【０００４】ロータリートランス用フェライトコアは通
常次のようにして作製される。まず、図１７に示すよう
に、円筒型フェライト焼結体を作製し、次に所望の寸法
精度を得るために特殊な機械加工で仕上げるが、上記フ
ェライト焼結体を作成する方法としては、同図において
所望の組成で原料を配合，混合した後、１０００℃以下
の温度で仮焼成する。次にこの仮焼成物を粉砕し、この
粉砕粉末に適量のポリビニルアルコール（ＰＶＡ）水溶
液などバインダーを加え造粒した後、この造粒粉を円筒
型金型で一軸圧縮成形する。こうして得られた円筒型成
形体を１０００℃以上の高温で本焼成して円筒型フェラ
イト焼結体を得るか、あるいは上記フェライト仮焼粉砕
粉末を樹脂と混練し、円筒状にトランスファー成形した
後、脱脂のための熱処理工程を経て同じく１０００℃以
上の高温本焼成を行って同様のフェライト焼結体を得る
という２つの方法がある（特開昭６１−８４００６号公
報参照）。A ferrite core for a rotary transformer is usually manufactured as follows. First, as shown in FIG. 17, a cylindrical ferrite sintered body is produced, and then, it is finished by a special machining process to obtain a desired dimensional accuracy. In the figure, the raw materials are blended and mixed with a desired composition, and then temporarily calcined at a temperature of 1000 ° C. or less. Next, the calcined product is pulverized, and a suitable amount of a binder such as an aqueous solution of polyvinyl alcohol (PVA) is added to the pulverized powder to granulate the granulated powder. The granulated powder is uniaxially compression-molded by a cylindrical mold. The cylindrical molded body obtained in this way is fired at a high temperature of 1000 ° C. or higher to obtain a cylindrical ferrite sintered body, or the ferrite calcined and pulverized powder is kneaded with a resin, and transfer molded into a cylindrical shape. There are two methods in which a similar ferrite sintered body is obtained by performing a high-temperature main firing at 1000 ° C. or higher through a heat treatment step for degreasing (see JP-A-61-84006).
【０００５】しかし、上記のどちらの方法であっても得
られたフェライト焼結体は、焼成前の成形体作製時に一
軸成形の場合は成形体中央部の圧力伝達が不十分になる
のは避けられず、成形密度の不均一が原因で図１８に示
すように焼結体３４の中央部に反りが発生したり、成形
体３３の寸法に比べ１０％以上の大きい収縮を伴うの
で、そのままでは寸法および精度的にもロータリートラ
ンスコアとしての厳しい要求仕様内に納めることは非常
に困難である。However, the ferrite sintered body obtained by either of the above methods is required to avoid insufficient pressure transmission at the center of the compact in the case of uniaxial compaction during fabrication of the compact before firing. As shown in FIG. 18, warpage occurs at the center of the sintered body 34 due to uneven molding density, and the sintered body 34 is shrunk by 10% or more compared to the dimensions of the molded body 33. It is very difficult to meet the strict requirements for a rotary transformer core in terms of size and accuracy.
【０００６】従って、たとえば円筒型コアを作る場合は
通常次のようになされている。まずその内外径が所望の
寸法よりも約１mm以上の余裕をもった円筒型フェライト
焼結体を用意し、この円筒型コアの外周面をセンタレス
グラインダで１次研削し、次にこの外周面を基準にして
内周面を内面研削機で粗研削し、その後内外周面両方と
もに特殊研削機で表面仕上げした後、必要チャンネル数
のコイル用凹溝を内周もしくは外周に沿って溝研削砥石
または回転連続刃で同時溝加工されて円筒型ロータリー
トランスコアの最終製品としての寸法精度を得ている。Therefore, for example, when a cylindrical core is manufactured, the following is usually performed. First, a cylindrical ferrite sintered body whose inner and outer diameters have a margin of about 1 mm or more from the desired dimension is prepared, and the outer peripheral surface of the cylindrical core is first ground by a centerless grinder, and then the outer peripheral surface is After roughing the inner peripheral surface with an internal grinding machine as a reference, and then finishing both the inner and outer peripheral surfaces with a special grinder, groove grooves for coil of the required number of channels along the inner or outer circumference Simultaneous groove processing is performed by the rotary continuous blade to obtain dimensional accuracy as the final product of the cylindrical rotary transformer core.
【０００７】この際、特に精度が必要な部分は２つの円
筒型コアの相対間隙寸法であり、また加工工数としては
溝加工の占める割合が最も高い。その後、コイル用凹溝
にコイル巻線を行い、内側コアと外側コアを組立ててロ
ータリートランスの完成品とする。At this time, the portion requiring particularly high precision is the relative gap size between the two cylindrical cores, and the proportion of the groove processing is the highest as the number of processing steps. Thereafter, coil winding is performed on the groove for the coil, and the inner core and the outer core are assembled to obtain a completed rotary transformer.
【０００８】[0008]
【発明が解決しようとする課題】このように従来法によ
る円筒型ロータリートランスコアでは、焼結品が大幅に
収縮することや焼結品の中央部の反りの現象は不可避
で、収縮量をあらかじめ見込んで余裕ある寸法で円筒型
もしくは円板型フェライト焼結品を作製し、粗研削から
最終的に精密加工で所望の寸法，精度を出し、さらにコ
イル装着用の溝加工を行うことによってロータリートラ
ンス用フェライトコアに仕上げている。しかし、この方
法では特に溝加工をはじめとして加工工数が多いこと
や、また材料が堅いため加工時に割れや欠けなどが生じ
るなど工程歩留りが悪いため、低コストで作るのが難し
いという大きな課題があった。As described above, in the cylindrical rotary transformer core according to the conventional method, a large shrinkage of the sintered product and a warping phenomenon at the center of the sintered product are inevitable. A cylindrical or disc-shaped ferrite sintered product with a sufficient size is expected, and the desired dimensions and precision are finally obtained by rough machining from precision grinding, and furthermore, a groove for coil mounting is processed to produce a rotary transformer. Finished into ferrite core for use. However, this method has the major problems that it is difficult to make it at low cost because of the large number of processing steps, especially for grooving, and the poor process yield such as cracking and chipping due to the rigid material. Was.
【０００９】さらに従来の方法では外側コアの内周面の
溝形成を金型成形によって作製する方法はなく、溝加工
は全て機械加工で行う方法しかなかった。Further, in the conventional method, there is no method of forming a groove on the inner peripheral surface of the outer core by molding, and there is only a method of performing all groove processing by machining.
【００１０】本発明は上述した従来技術の欠点を解消
し、金型成形によって外側コアの内周面に溝形成をする
ことで円筒型ロータリートランスを安価に製造できる方
法を提供するものである。The present invention solves the above-mentioned drawbacks of the prior art and provides a method for manufacturing a cylindrical rotary transformer at low cost by forming a groove on the inner peripheral surface of an outer core by molding.
【００１１】[0011]
【課題を解決するための手段】上記課題を解決するため
に本発明は、中心軸の少なくとも一部に放射方向に突出
する縦溝形成片をもった縦溝形成用金型の中心軸の周辺
に２つ以上に分割され上記縦溝形成用金型の周辺に横溝
を形成する突条を複数個周面に設けた横溝形成用金型を
組み合わせて内形金型とし、この内形金型の外周に円筒
状の外形金型を被せ、この外形金型と内形金型の間に充
填する所望量の磁性粉を予備成形した成形物を少なくと
も２個以上に分割して両金型内に投入し、上記内形金型
と外形金型との間に押し金型を入りこませて上記磁性粉
を圧縮成形した後、内形金型の縦溝形成用金型を抜き出
し、横溝形成用金型を中心軸方向に移動させて成形体よ
り抜き出し、押し金型を抜きとった後、外形金型から抜
き出した成形体を高温処理して円筒状コアとし、この円
筒状コアの内周面の横溝にコイルを組み込んで外側コイ
ルを構成し、また外周面の横溝にコイルを形成した内側
コイルを上記外側コイル内に組込むロータリートランス
の製造方法に関するものである。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a mold for forming a vertical groove having a vertical groove forming piece protruding in a radial direction on at least a part of the central axis. The inner mold is formed by combining a horizontal groove forming mold in which a plurality of ridges are formed on the peripheral surface of the vertical groove forming mold and formed with a plurality of ridges around the vertical groove forming mold. The outer periphery of the mold is covered with a cylindrical outer mold, and a molded article obtained by pre-forming a desired amount of magnetic powder to be filled between the outer mold and the inner mold is divided into at least two or more pieces. After the magnetic powder is compression-molded by inserting a pressing mold between the inner mold and the outer mold, the mold for forming the vertical groove of the inner mold is extracted, and the horizontal groove is formed. After moving the mold in the direction of the center axis and extracting it from the molded body, removing the pressing mold, the molded body extracted from the external mold A rotary process which heat-processes to form a cylindrical core, incorporates a coil into a lateral groove on the inner peripheral surface of the cylindrical core to form an outer coil, and incorporates an inner coil having a coil formed in a lateral groove on the outer peripheral surface into the outer coil. The present invention relates to a method for manufacturing a transformer.
【００１２】[0012]
【作用】上記製造方法により、従来方法では不可避であ
った成形密度の不均一性による焼成時の反りや大きな収
縮の発生に伴う変形のために円筒型コア内周面の溝形成
を機械加工で行っていた方法とは異なり、均一成形体の
実現と金型成形によってコアを作製するため、これまで
に行われていた溝加工工程が不要になるという効果があ
るため、従来のものよりはるかに安価なものが得られる
ことになる。According to the above-mentioned manufacturing method, the grooves on the inner peripheral surface of the cylindrical core are formed by machining due to the deformation caused by the occurrence of warpage and large shrinkage due to non-uniformity of the molding density which was inevitable in the conventional method. Unlike the method that had been used, since the core was manufactured by realizing a uniform molded body and molding, there was an effect that the groove processing step that had been performed so far was unnecessary, so it was much more than the conventional method Inexpensive things will be obtained.
【００１３】[0013]
【実施例】以下、本発明の実施例について説明する。Embodiments of the present invention will be described below.
【００１４】上記ロータリートランス用コアの製造方法
としては、一例として図２に示すように、まず中心軸７
に放射方向に突出した４枚の板状の縦溝形成片８をもっ
た縦溝形成用金型９の周辺に、４つに分割されしかも両
端にテーパ部１０ａをもち横溝を形成する突条１０ｂを
所望のチャンネル数だけ周辺に設けた横溝形成用金型１
０を内側円筒部にテーパを有するキャップ１１，１２で
縦溝形成用金型９の周辺に組み合わせて固定し図３に示
すような内形金型１３を得る。次に図４のように内形金
型１３を下押し金型１４に挿入した後、図５に示すよう
にこの内形金型１３の外周に円筒状の外形金型１５を被
せ、この外形金型１５と内形金型１３の間に所望量を２
個以上に分割した予備成形体１６を中央部が最も高密度
の予備成形体になるように投入し、上記内形金型１３と
外形金型１５との間に下押し金型１４と上押し金型１７
を入りこませて上記予備成形体１６を図６のように圧縮
成形する。As an example of a method of manufacturing the core for a rotary transformer, as shown in FIG.
In the vicinity of a vertical groove forming die 9 having four plate-shaped vertical groove forming pieces 8 protruding in the radial direction, a rib is divided into four and has a tapered portion 10a at both ends to form a horizontal groove. A lateral groove forming mold 1 in which 10b are provided around the desired number of channels.
0 is combined with and fixed to the periphery of the vertical groove forming die 9 by caps 11 and 12 having a tapered inner cylindrical portion to obtain an inner die 13 as shown in FIG. Next, as shown in FIG. 4, the inner mold 13 is inserted into the downward press mold 14, and then, as shown in FIG. The desired amount is 2 between the mold 15 and the inner mold 13.
The preformed body 16 divided into pieces or more is put in such a manner that the central part becomes the preformed body having the highest density, and the lower pressing die 14 and the upper pressing die are interposed between the inner die 13 and the outer die 15. Type 17
And the preform 16 is compression molded as shown in FIG.
【００１５】次に図７に示すように４個の横溝形成用金
型１０の固定用キャップ１１，１２を抜きとった後、図
８に示すように縦溝形成用金型９を抜き出す。Next, as shown in FIG. 7, the fixing caps 11, 12 of the four lateral groove forming dies 10 are removed, and then the vertical groove forming dies 9 are removed as shown in FIG.
【００１６】次に図９に示すように上下端部に相反する
ネジ部をそれぞれ有する中心棒３０を縦溝形成用金型９
を抜き取った空間を挿入し、上下端部のネジ部に内側円
筒部にテーパをもつ抜き型３１，３２を上下方向から４
個の横溝形成用金型１０のテーパ部直前までねじ込む。
そして図１０に示すように中心棒３０を抜き型３１，３
２がお互いが接近する方向に回転させることにより、抜
き型３１，３２を同速度で可動させ、抜き型と横溝形成
用金型１０のお互いのテーパを利用することで、４個の
横溝形成用金型１０を中心軸方向に移動させて図１１の
ように成形体１８より抜き出し、そして最後に図１２に
示すように外形金型１５から成形体１８を抜き型１９に
よって抜き出すのである。Next, as shown in FIG. 9, a center rod 30 having oppositely threaded portions at upper and lower ends is inserted into a vertical groove forming mold 9.
Are inserted into the space from which the holes have been removed, and punching dies 31 and 32 having a tapered inner cylindrical portion are inserted into the upper and lower threaded portions from above and below.
The horizontal groove forming die 10 is screwed down to just before the tapered portion.
Then, as shown in FIG.
2 are rotated in the direction in which they approach each other, so that the punching dies 31 and 32 are moved at the same speed, and by utilizing the mutual taper of the punching die and the lateral groove forming die 10, four lateral grooves are formed. The mold 10 is moved in the direction of the central axis to be extracted from the molded body 18 as shown in FIG. 11, and finally, the molded body 18 is extracted from the external mold 15 by the punch 19 as shown in FIG.
【００１７】この際、成形体１８の取り出し順序はこの
例に限ることはなく、まず外形金型１５から成形体１８
を抜いた後に内形金型１３の縦溝形成用金型９を抜き出
し、横溝形成用金型１０を上記と同様に中心軸方向に移
動させて成形体１８より抜き出してもよいものである。At this time, the order of taking out the molded body 18 is not limited to this example.
After extracting the mold, the mold 9 for forming the vertical groove of the inner mold 13 may be extracted, and the mold 10 for forming the horizontal groove may be moved in the central axis direction in the same manner as above, and may be extracted from the molded body 18.
【００１８】次にこうして得られた成形体１８を高温処
理して円筒状コアとし、図１３に示すように、この円筒
状コアを外側コア２としてその内周面の横溝にコイル４
を組み込み外側コイルを構成し、また内側コアではその
外周面の横溝にコイル４を形成して内側コイルとし、こ
れを上記外側コイル内に組み込んでロータリートランス
を作製するのである。Next, the compact 18 thus obtained is subjected to a high temperature treatment to form a cylindrical core. As shown in FIG. 13, this cylindrical core is used as the outer core 2 and the coil 4 is inserted into the lateral groove on the inner peripheral surface thereof.
To form an outer coil. In the inner core, a coil 4 is formed in a lateral groove on the outer peripheral surface to form an inner coil, which is incorporated in the outer coil to produce a rotary transformer.
【００１９】ここでは縦溝数が４本の場合の一例につい
て説明したがこれに限られるものではなく、基本的には
２本以上の縦溝数をもった縦溝形成用金型とそれに相当
した数に分割された横溝形成用金型とが組み合わされた
構成をしていればよいものである。Here, an example in which the number of vertical grooves is four has been described. However, the present invention is not limited to this. Basically, a vertical groove forming die having two or more vertical grooves and a mold corresponding thereto. It suffices to have a configuration in which the lateral groove forming dies divided into the predetermined number are combined.
【００２０】磁性粉の予備成形体を作製する際、個数は
２個以上が望ましく成形圧力としては予備成形体がハン
ドリングで壊れない程度であれば良いが、本成形におい
て中央部に配する予備成形体は少なくとも両端部に配す
る予備成形体以上の圧力で作製し、成形密度としては中
央部が最も高い状態が良く、本成形圧力近傍あるいはそ
れ以上で作製するのが好ましい。また形状は本金型内に
容易に投入できるものであれば良く本金型内の形状と相
似形のものが望ましい。When preparing a preform of magnetic powder, the number is preferably two or more, and the molding pressure may be such that the preform is not broken by handling. The body is produced at a pressure equal to or higher than that of the preformed body disposed at least at both ends, and the molding density is preferably the highest in the central part, and is preferably produced at or near the main molding pressure. The shape may be any shape that can be easily put into the main mold, and a shape similar to the shape in the main mold is desirable.
【００２１】また磁性粉としてはフェライトの仮焼成
粉、または高温焼成で十分フェライト化が進んだ高結晶
性フェライト磁性粉とガラス粉末との混合物、あるいは
それらと樹脂の混合物からなるものでもよい。The magnetic powder may be a preliminarily baked powder of ferrite, a mixture of a highly crystalline ferrite magnetic powder whose ferrite has been sufficiently sintered at a high temperature and glass powder, or a mixture of these and a resin.
【００２２】さらに圧縮成形の際、上記ガラス粉末ある
いは樹脂の混合物の場合はそのガラス粉末あるいは樹脂
が溶融する温度の加熱状態で行うこともできる。また樹
脂は熱硬化性，熱可塑性のいずれでも使用できるもので
ある。Further, in the case of compression molding, in the case of a mixture of the above-mentioned glass powder or resin, it may be carried out in a heated state at a temperature at which the glass powder or resin is melted. The resin can be either thermosetting or thermoplastic.
【００２３】以下、具体的な実施例について説明する。 （実施例１）図１に示すようにＦｅ2Ｏ3 ４８mol％，
ＮｉＯ １４mol％，ＺｎＯ ３４mol％，ＣｕＯ ４mo
l％よりなる出発原料を配合，混合し、この混合物にポ
リビニルアルコール（ＰＶＡ）の５wt％水溶液を５wt％
加え、これを造粒したものを１２５０℃で６時間焼成し
たものを粉砕して、平均粒径５０μｍのＮｉ−Ｚｎ−Ｃ
ｕ系ソフトフェライト本焼成粉を準備した。この粉末を
Ｘ線解析した結果、ソフトフェライト特有の鋭いスピネ
ル構造回折線が得られ結晶性の非常に高い磁性粉末であ
ることを確認した。次に上記高結晶性フェライト磁性粉
末に対して軟化点（Ｔｄ）３７０℃、平均粒径１μｍの
無アルカリホウケイ酸鉛系ガラス粉末を３wt％加えて混
合した後、造粒する。Hereinafter, specific embodiments will be described. (Example 1) Fe 2 O 3 as shown in FIG. 1 48 mol%,
NiO 14mol%, ZnO 34mol%, CuO 4mo
1% of a starting material is mixed and mixed, and a 5 wt% aqueous solution of polyvinyl alcohol (PVA) is added to the mixture at 5 wt%.
In addition, what was granulated and fired at 1250 ° C. for 6 hours was crushed to obtain a Ni—Zn—C having an average particle diameter of 50 μm.
A u-based soft ferrite main firing powder was prepared. As a result of X-ray analysis of this powder, a sharp spinel structure diffraction line peculiar to soft ferrite was obtained, and it was confirmed that the powder was a magnetic powder having extremely high crystallinity. Next, 3 wt% of a non-alkali lead borosilicate glass powder having a softening point (Td) of 370 ° C. and an average particle diameter of 1 μm is added to the highly crystalline ferrite magnetic powder and mixed, followed by granulation.
【００２４】次に、２つの円筒型コアがそれぞれ対向す
る面に各々コイルが巻装されるための凹溝と縦溝を成形
によって作製するため、外側コア成形の場合は図２〜図
１２に示す製造方法で金型内に所望量の造粒粉を３分割
し、図５に示すように本金型内に容易に入る形状で中央
部用予備成形体１個を３ton／cm2、両端部用予備成形体
２個を１ton／cm2の圧力でそれぞれ作製した。これらを
本金型内に投入し、３ton／cm2の圧力で本成形し、横
溝，縦溝を有した外側コア用の円筒成形体を得る。Next, in order to form a concave groove and a vertical groove for winding the coil on the surface where the two cylindrical cores respectively face each other, the outer core is formed as shown in FIGS. The desired amount of granulated powder is divided into three parts in a mold by the manufacturing method shown in FIG. 5, and one preform for the central part is 3 ton / cm 2 in a shape easily enterable in the mold as shown in FIG. Two part preforms were produced at a pressure of 1 ton / cm 2 . These are put into a main mold and are main-formed at a pressure of 3 ton / cm 2 to obtain a cylindrical molded body for the outer core having horizontal grooves and vertical grooves.
【００２５】また内側コアの場合、外周面に凹溝を形成
するため、図１５，図１６に示すように凸部を有した４
個の割り金型２１に上記造粒粉を所望量充填し、上記と
同様３ton／cm2の圧力で上下の押し金型２２，２３で加
圧成形し、コイル用凹溝およびショートリング用凹溝、
さらには縦溝を有した内側コア用の円筒成形体２４を作
製した。In the case of the inner core, in order to form a concave groove on the outer peripheral surface, as shown in FIGS.
A desired amount of the above-mentioned granulated powder is filled in each split mold 21, and the upper and lower pressing dies 22, 23 are press-formed with a pressure of 3 ton / cm 2 in the same manner as described above, and the concave groove for the coil and the concave for the short ring are formed. groove,
Further, a cylindrical molded body 24 for the inner core having a vertical groove was produced.
【００２６】そしてこれら成形体を電気炉内に個々に設
置し、１２００℃、６０分間空気中で加熱処理し、ガラ
ス結着型の円筒型ロータリートランス用フェライトコア
を得た。These compacts were individually placed in an electric furnace and heated in air at 1200 ° C. for 60 minutes to obtain a glass-bound ferrite core for a cylindrical rotary transformer.
【００２７】次に図１３に示すようにこれら凹溝３，５
にコイル４あるいはショートリング６を巻装し、２個の
コア１，２を組み合わせてロータリートランスを作製し
た。Next, as shown in FIG.
, A coil 4 or a short ring 6 was wound thereon, and two cores 1 and 2 were combined to produce a rotary transformer.
【００２８】上記実施例１の材料特性を（表１）に示し
た。実施例１では、コアの収縮率が０．１％以下と、ほ
とんど熱処理によるコア収縮がなく、またコアの中央部
の反りも０．０５％以下とほとんどないため金型寸法ど
おりのものが得られ、外側コアと内側コア間の間隙は、
７０μｍ以下の極めて高精度の円筒型ロータリートラン
スが実現でき、また磁気特性，トランス特性にも優れた
ものが得られた。The material properties of Example 1 are shown in (Table 1). In Example 1, the core shrinkage was 0.1% or less, there was almost no core shrinkage due to heat treatment, and the core warpage was almost 0.05% or less. And the gap between the outer core and the inner core is
An extremely high precision cylindrical rotary transformer having a diameter of 70 μm or less can be realized, and excellent magnetic and transformer characteristics can be obtained.
【００２９】ここでコア中央部の反り率はコア両端部の
寸法を基準にした反り量の寸法を％表示している。Here, the warpage ratio at the center of the core is expressed in% of the amount of warpage based on the size of both ends of the core.
【００３０】（実施例２）実施例１で用いた同一のフェ
ライト本焼粉に対して同一のガラス粉末を３wt％、樹脂
としてエポキシ粉末を５wt％加えて混合した後、樹脂の
軟化温度以上の９０℃で２分間熱混練し、これを粉砕，
造粒した後、この造粒粉を所望量だけ実施例１と同様の
金型に充填し、金型温度１８０℃で３０秒間、１ton／c
m2で圧縮成形し、円筒型成形体をそれぞれ２個作製し
た。Example 2 The same ferrite main powder used in Example 1 was mixed with 3 wt% of the same glass powder and 5 wt% of epoxy powder as a resin, and mixed. Heat kneading at 90 ° C for 2 minutes, pulverize,
After granulation, a desired amount of the granulated powder was filled in the same mold as in Example 1, and the mold temperature was 180 ° C. for 30 seconds, and 1 ton / c.
By compression molding with m 2 , two cylindrical molded bodies were produced.
【００３１】次にこれら成形体を電気炉内に個々に設置
し、脱脂工程を経た後、１２００℃、６０分間空気中で
加熱処理しガラス結着型の円筒型ロータリートランス用
フェライトを得、そして実施例１と同様にしてロータリ
ートランスを作製した。Next, these compacts are individually placed in an electric furnace, subjected to a degreasing step, and then heat-treated in air at 1200 ° C. for 60 minutes to obtain a glass-bound ferrite for a cylindrical rotary transformer. A rotary transformer was manufactured in the same manner as in Example 1.
【００３２】上記実施例２の材料特性を（表１）に示し
た。実施例２では、コアの収縮率が０．１％以下と、ほ
とんど熱処理によるコア収縮がなく、またコアの中央部
の反りも０．０５％以下とほとんどないため金型寸法ど
おりのものが得られ、外側と内側コア間の間隙は、７０
μｍ以下の極めて高精度の円筒型ロータリートランスが
実現でき、また磁気特性，トランス特性にも優れたもの
が得られた。The material properties of Example 2 are shown in Table 1. In Example 2, the core shrinkage was 0.1% or less, there was almost no core shrinkage due to heat treatment, and the core warpage was almost 0.05% or less. And the gap between the outer and inner cores is 70
An extremely high precision cylindrical rotary transformer of less than μm could be realized, and a magnetic and transformer with excellent characteristics were obtained.
【００３３】（実施例３）実施例１と同一の配合組成を
もった出発原料の混合物に５wt％ＰＶＡ水溶液を５wt％
加え、この造粒粉を１０００℃、２時間で仮焼成を行
い、これを２〜５μｍに微粉砕し、この造粒粉を実施例
１，２と同様にして円筒型成形体をそれぞれ２個作製し
た。Example 3 A 5 wt% aqueous solution of PVA was added to a mixture of starting materials having the same composition as in Example 1 by 5 wt%.
In addition, the granulated powder was calcined at 1000 ° C. for 2 hours, and finely pulverized to 2 to 5 μm. The granulated powder was made into two cylindrical molded bodies in the same manner as in Examples 1 and 2. Produced.
【００３４】この成形品を電気炉内に設置し、１２００
℃、３時間空気中で焼成した後、徐冷しながら降温させ
Ｎｉ−Ｚｎ−Ｃｕ系フェライト焼結型の円筒型コアを得
た。This molded product was placed in an electric furnace, and 1200
After firing in air at 3 ° C. for 3 hours, the temperature was lowered while gradually cooling to obtain a cylindrical core of a Ni—Zn—Cu ferrite sintered type.
【００３５】上記実施例３の材料特性を（表１）に示し
た。実施例３ではコア収縮率が１０％になったが、中央
部コアの反りは０．５％以下と小さく、内側コア，外側
コアともに成形溝以外の内外周面を所望の寸法に最小限
の機械加工を施すことだけで簡単に高精度の円筒型ロー
タリートランスを得ることができ、また磁気特性，トラ
ンス特性にも優れたものが得られた。The material properties of Example 3 are shown in Table 1. In Example 3, the core shrinkage was 10%, but the warpage of the central core was as small as 0.5% or less. A high-precision cylindrical rotary transformer could be easily obtained only by machining, and a magnetic rotary transformer having excellent transformer characteristics was obtained.
【００３６】（実施例４）実施例１で用いた同一のフェ
ライト本焼粉に対して同一のガラス粉末を１０wt％加え
て混合した後、ＰＶＡ水溶液で造粒した。次にこの造粒
粉を実施例２と同様の方法でステライト製の同金型に所
望量均一に充填する。この際外形金型には図１４に示す
ように金型の周囲にヒータ２０が取りつけられ、温度４
５０℃で１分間、１ton／cm2の圧力で上下押し金型を圧
縮し、磁性粉間に介在するガラス粉末を軟化溶融させな
がら成形を行った。そして成形が終了した後、金型を冷
却しコアを実施例２と同様にして取り出し、円筒型成形
体をそれぞれ２個作製した。Example 4 The same ferrite main powder used in Example 1 was mixed with 10 wt% of the same glass powder, mixed, and then granulated with an aqueous PVA solution. Next, the granulated powder is uniformly filled in a desired amount in the same mold made of stellite in the same manner as in Example 2. At this time, a heater 20 is attached to the outer mold around the mold as shown in FIG.
The upper and lower pressing molds were compressed at 50 ° C. for 1 minute under a pressure of 1 ton / cm 2 , and molding was performed while softening and melting the glass powder interposed between the magnetic powders. After the completion of the molding, the mold was cooled, and the core was taken out in the same manner as in Example 2 to produce two cylindrical molded bodies.
【００３７】次にこれら成形体を電気炉内に個々に設置
し、１２００℃、６０分間空気中で加熱処理しガラス結
着型の円筒型ロータリートランス用フェライトコアを
得、そして実施例２と同様にしてロータリートランスを
作製した。Next, these compacts were individually placed in an electric furnace and heat-treated in air at 1200 ° C. for 60 minutes to obtain a glass-bound cylindrical ferrite core for a rotary transformer. To produce a rotary transformer.
【００３８】上記実施例４の材料特性を（表１）に示し
た。実施例４では、コアの収縮率が１％で熱処理による
コア収縮が小さく、またコア中央部の反りも０．１％以
下と非常に小さいため金型寸法に近いものが得られ、外
側と内側コア間の間隙は、７０μｍ以下の極めて高精度
の円筒型ロータリートランスが実現でき、また磁気特
性，トランス特性にも優れたものが得られた。The material properties of Example 4 are shown in (Table 1). In Example 4, the core shrinkage was 1%, the core shrinkage due to the heat treatment was small, and the warpage at the center of the core was very small at 0.1% or less. As for the gap between the cores, an extremely high precision cylindrical rotary transformer having a diameter of 70 μm or less was realized, and a magnetic rotary transformer excellent in transformer characteristics was obtained.
【００３９】（比較例１）実施例１と同一の配合組成を
もった出発原料の混合物に５wt％ＰＶＡ水溶液を５wt％
加え、この造粒粉を１０００℃、２時間で仮焼成を行
い、これを２〜５μｍに微粉砕し、この造粒粉を実施例
１〜３と同様にして円筒型成形体をそれぞれ２個作製し
た。Comparative Example 1 A 5 wt% aqueous solution of PVA was added to a mixture of starting materials having the same composition as in Example 1 to obtain a mixture of 5 wt%.
In addition, the granulated powder was calcined at 1000 ° C. for 2 hours, finely pulverized to 2 to 5 μm, and the granulated powder was made into two cylindrical molded bodies in the same manner as in Examples 1 to 3. Produced.
【００４０】この成形品を電気炉内に設置し、１２００
℃、３時間空気中で焼成した後、徐冷しながら降温させ
Ｎｉ−Ｚｎ−Ｃｕ系フェライト焼結型の円筒型コアを得
た。This molded product was placed in an electric furnace, and 1200
After firing in air at 3 ° C. for 3 hours, the temperature was lowered while gradually cooling to obtain a cylindrical core of a Ni—Zn—Cu ferrite sintered type.
【００４１】上記比較例１の材料特性を（表１）に示し
た。The material properties of Comparative Example 1 are shown in Table 1.
【００４２】[0042]
【表１】 [Table 1]
【００４３】比較例１ではコア収縮率が１０％になった
が、中央部コアの反りは２％以下と小さく、内側コア，
外側コアともに成形溝以外の内外周面を所望の寸法に最
小限の機械加工を施すことだけで簡単に高精度の円筒型
ロータリートランスを得ることができ、また磁気特性，
トランス特性にも優れたものが得られた。In Comparative Example 1, the core shrinkage was 10%, but the warpage of the central core was as small as 2% or less.
A high-precision cylindrical rotary transformer can be easily obtained by simply performing the minimum machining on the inner and outer peripheral surfaces of the outer core other than the molding grooves to the desired dimensions.
Excellent transformer characteristics were obtained.
【００４４】[0044]
【発明の効果】以上のように本発明によるロータリート
ランスの製造方法は、従来方法が全てコアを機械加工に
よって得るのに対し、金型成形によって作製するため製
造プロセスが非常に簡単になり、加工コストも大幅に低
減できることで、従来よりもはるかに安価なロータリー
トランスが得られるものである。As described above, in the method of manufacturing a rotary transformer according to the present invention, the core is obtained by machining in the conventional method, but the manufacturing process is very simple because the core is manufactured by molding. Since the cost can be significantly reduced, a rotary transformer that is far less expensive than the conventional one can be obtained.
【図１】本発明のロータリートランスの製造方法の一実
施例を示す製造工程の工程図FIG. 1 is a process diagram of a manufacturing process showing one embodiment of a method for manufacturing a rotary transformer according to the present invention.
【図２】同方法に用いる内形金型の分解斜視図FIG. 2 is an exploded perspective view of an inner mold used in the method.
【図３】同内形金型の斜視図FIG. 3 is a perspective view of the inner mold.
【図４】同内形金型を下押し金型に組み込んだ状態の斜
視図FIG. 4 is a perspective view showing a state in which the inner mold is assembled into a downward pressing mold.
【図５】同内形金型に外形金型を組み込んで予備成形物
を供給する状態の斜視図FIG. 5 is a perspective view showing a state in which an outer mold is incorporated into the inner mold and a preform is supplied.
【図６】同成形金型の成形時の斜視図FIG. 6 is a perspective view of the molding die during molding.
【図７】同成形後ギャップを取り除く状態を示す一部切
欠斜視図FIG. 7 is a partially cutaway perspective view showing a state in which a gap is removed after the molding.
【図８】同縦溝形成用金型を抜き取った状態の一部切欠
斜視図FIG. 8 is a partially cutaway perspective view showing a state in which the vertical groove forming mold is removed.
【図９】同抜き型を組み込む状態を示す一部切欠斜視図FIG. 9 is a partially cutaway perspective view showing a state in which the punching die is incorporated.
【図１０】同抜き型を組み込んだ状態の一部切欠斜視図FIG. 10 is a partially cutaway perspective view showing a state where the punching die is incorporated.
【図１１】同横溝形成用金型を抜いた状態の斜視図FIG. 11 is a perspective view of a state where the lateral groove forming mold is removed.
【図１２】同成形体を取り出す状態を示す一部切欠斜視
図FIG. 12 is a partially cutaway perspective view showing a state in which the molded body is taken out.
【図１３】同方法によって形成したロータリートランス
の断面図FIG. 13 is a sectional view of a rotary transformer formed by the same method.
【図１４】他の実施例の成形金型の斜視図FIG. 14 is a perspective view of a molding die according to another embodiment.
【図１５】本発明における内側コアの成形を示す断面図FIG. 15 is a sectional view showing the molding of the inner core according to the present invention.
【図１６】同説明図FIG. 16 is an explanatory view of the same.
【図１７】従来のロータリートランスの製造工程を示す
工程図FIG. 17 is a process diagram showing a conventional rotary transformer manufacturing process.
【図１８】従来の円筒型成形体の焼成によるコアの反り
と収縮の状態を示す斜視図FIG. 18 is a perspective view showing a state in which a core is warped and contracted by firing a conventional cylindrical molded body.
１ 内側コア ２ 外側コア ３ コイル用凹溝 ４ コイル ５ ショートリング用凹溝 ６ ショートリング ７ 中心軸 ８ 縦溝形成片 ９ 縦溝形成用金型 １０ 横溝形成用金型 １０ａ テーパ部 １０ｂ 突条 １１，１２ キャップ １３ 内形金型 １４ 下押し金型 １５ 外形金型 １６ 磁性粉の予備成形物 １７ 上押し金型 １８ 成形体 １９ 抜き型 ２０ ヒーター ２１ 割り金型 ２２ 上押し金型 ２３ 下押し金型 ２４ 成形体 ３０ 中心棒 ３１，３２ 抜き型 ３３ 円筒型成形体 ３４ 焼成体 REFERENCE SIGNS LIST 1 inner core 2 outer core 3 concave groove for coil 4 coil 5 concave groove for short ring 6 short ring 7 center axis 8 vertical groove forming piece 9 vertical groove forming die 10 horizontal groove forming die 10a taper portion 10b ridge 11 , 12 Cap 13 Inner mold 14 Down-press mold 15 Outer mold 16 Preform of magnetic powder 17 Up-press mold 18 Molded body 19 Die-cut 20 Heater 21 Split mold 22 Up-press mold 23 Down-press mold 24 Molded body 30 Center rod 31, 32 Die mold 33 Cylindrical molded body 34 Fired body
フロントページの続き (56)参考文献 特開 昭61−84006（ＪＰ，Ａ) 特開 昭63−51610（ＪＰ，Ａ) 特開 平３−289106（ＪＰ，Ａ) 特開 平３−289112（ＪＰ，Ａ) 特開 平３−289113（ＪＰ，Ａ) 特開 平３−71575（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01F 38/14 H01F 41/02 Continuation of front page (56) References JP-A-61-84006 (JP, A) JP-A-63-51610 (JP, A) JP-A-3-289106 (JP, A) JP-A-3-289112 (JP) JP-A-3-289113 (JP, A) JP-A-3-71575 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H01F 38/14 H01F 41/02
Claims (4)
する縦溝形成片をもった縦溝形成用金型の中心軸の周辺
に２つ以上に分割され上記縦溝形成用金型の周辺に横溝
を形成する突条を複数個周面に設けた横溝形成用金型を
組合せて内形金型とし、この内形金型の外周に円筒状の
外形金型を被せ、この外形金型と内形金型の間に充填す
る所望量の磁性粉を予備成形した成形物を少なくとも２
個以上に分割して両金型内に投入し、次に上記内形金型
と外形金型との間に押し金型を入りこませて上記磁性粉
の成形物を圧縮成形した後、まず内形金型の縦溝形成用
金型を抜き出し、横溝形成用金型を中心軸方向に移動さ
せて成形体より抜き出し、押し金型を抜きとった後、外
形金型から抜き出した成形体を高温処理して円筒状コア
とし、この円筒状コアの内周面の横溝にコイルを組込ん
で外側コイルを構成し、また外周面の横溝にコイルを形
成した内側コイルを上記外側コイル内に組込むロータリ
ートランスの製造方法。1. A longitudinal groove forming die having a longitudinal groove forming piece protruding in a radial direction on at least a part of a central axis thereof. An inner mold is formed by combining lateral groove forming dies having a plurality of ridges forming lateral grooves on the peripheral surface, and a cylindrical outer mold is placed on the outer periphery of the inner mold. A molded article preformed with a desired amount of magnetic powder to be filled between the mold and the inner mold is at least 2
After being divided into more than one piece and put into both molds, and then press-molding between the inner mold and the outer mold to press-mold the molded product of the magnetic powder, After extracting the mold for forming the vertical groove of the inner mold, moving the mold for forming the horizontal groove in the direction of the central axis, extracting from the molded body, removing the pressing mold, and then removing the molded body extracted from the outer mold. A high temperature treatment is performed to form a cylindrical core, an outer coil is formed by incorporating a coil in a lateral groove on the inner peripheral surface of the cylindrical core, and an inner coil in which a coil is formed in a lateral groove on the outer peripheral surface is incorporated into the outer coil. Manufacturing method of rotary transformer.
形密度がそれぞれ異なっていてこれらを金型内に充填す
る際に中央部に配置した予備成形物の成形密度が最も高
く、中央部から両端に近づくに従って予備成形物の成形
密度が低くなるようにした請求項１記載のロータリート
ランスの製造方法。2. The molding density of at least two or more preforms is different from each other, and when these are filled in a mold, the preform placed at the center has the highest molding density. 2. The method for manufacturing a rotary transformer according to claim 1, wherein the molding density of the preform decreases as the distance from the ends increases.
進んだ高結晶性フェライト磁性粉末とガラス粉末との混
合物からなるものかあるいはその磁性粉末またはそれら
混合物に樹脂を含むものからなる請求項１記載のロータ
リートランスの製造方法。3. A magnetic powder comprising a mixture of a highly crystalline ferrite magnetic powder and a glass powder, which have been sufficiently ferritized by firing at a high temperature, or a resin containing the magnetic powder or the mixture thereof. 2. The method for producing a rotary transformer according to 1.
融する加熱状態で行われる請求項３記載のロータリート
ランスの製造方法。4. The method for producing a rotary transformer according to claim 3, wherein the compression molding is performed in a heated state in which the glass powder or the resin is melted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3202841A JP3039021B2 (en) | 1991-08-13 | 1991-08-13 | Manufacturing method of rotary transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3202841A JP3039021B2 (en) | 1991-08-13 | 1991-08-13 | Manufacturing method of rotary transformer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0547575A JPH0547575A (en) | 1993-02-26 |
| JP3039021B2 true JP3039021B2 (en) | 2000-05-08 |
Family
ID=16464080
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3202841A Expired - Fee Related JP3039021B2 (en) | 1991-08-13 | 1991-08-13 | Manufacturing method of rotary transformer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3039021B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100733652B1 (en) | 2000-06-13 | 2007-06-28 | 미츠비시 가스 가가쿠 가부시키가이샤 | Polyester resin and molded article |
| US9064947B2 (en) | 2009-08-04 | 2015-06-23 | Gan Systems Inc. | Island matrixed gallium nitride microwave and power switching transistors |
| JP2012119452A (en) * | 2010-11-30 | 2012-06-21 | Sumitomo Electric Ind Ltd | Manufacturing method for reactor coil |
-
1991
- 1991-08-13 JP JP3202841A patent/JP3039021B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0547575A (en) | 1993-02-26 |
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