JPH0560317B2 - - Google Patents
Info
- Publication number
- JPH0560317B2 JPH0560317B2 JP57130932A JP13093282A JPH0560317B2 JP H0560317 B2 JPH0560317 B2 JP H0560317B2 JP 57130932 A JP57130932 A JP 57130932A JP 13093282 A JP13093282 A JP 13093282A JP H0560317 B2 JPH0560317 B2 JP H0560317B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic circuit
- pole piece
- voice coil
- sintered metal
- 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 - Lifetime
Links
- 239000002184 metal Substances 0.000 claims description 24
- 229910052751 metal Inorganic materials 0.000 claims description 24
- 239000000463 material Substances 0.000 claims description 11
- 239000006247 magnetic powder Substances 0.000 claims description 6
- 239000000696 magnetic material Substances 0.000 claims description 5
- 239000000843 powder Substances 0.000 claims description 4
- 238000004663 powder metallurgy Methods 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 11
- 229910052802 copper Inorganic materials 0.000 description 11
- 239000010949 copper Substances 0.000 description 11
- 230000000694 effects Effects 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 7
- 230000004907 flux Effects 0.000 description 7
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000006249 magnetic particle Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 230000005381 magnetic domain Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
- H04R9/02—Details
- H04R9/025—Magnetic circuit
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、スピーカやマイクロホン等の電気音
響変換器、特にダイナミツク型電気音響変換器の
磁気回路に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic circuit for an electroacoustic transducer such as a speaker or a microphone, particularly a dynamic electroacoustic transducer.
背景技術とその問題点
ダイナミツク型電気音響変換器例えばダイナミ
ツク・スピーカにおいては、ボイスコイルに流れ
る音声信号電流によつて発生する交流磁束がその
コイル近傍の磁気回路部材を通過するとき渦電流
を生じ、この渦電流によりボイス・コイルに流れ
る音声電流に歪みを生じるため、スピーカから輻
射される音声に音の歪みが現われる。従来の磁気
回路では、このような電流歪み対策として、銅キ
ヤツプや銅メツキをポールピースに施したり、積
層した珪素鋼板をリング状にして磁気回路に挿入
したりして、ヒステリシス損を低減するようにし
ていた。第１及び第２図は、かかる従来例を示す
略断面図である。第１図において、１は振動板、
２はボイスコイル、３は磁石（フエライト）、４
はトツププレート、５はULMカツトされたポー
ルピース、６は銅キヤツプ、７はヨークを示す。
本例は、ポールピース５に銅キヤツプ６と共に
ULMカツトを施したものである。ULMとはウル
トラ・リニア・マグネチツク・サーキツトの略称
で、ULMカツトは銅キヤツプ６と同様に電流歪
みを低減する作用を有するものである。第２図に
おいて、第１図と対応する部分には同一の符号を
付してある。９は積層リング（ラミネート部材）、
Ｍは交流磁界におけるメジヤー・ループ、Ｎは交
流磁界におけるマイナー・ループを示す。マイナ
ー・ループＮは、ボイスコイル２の個々のコイル
による交流磁界である。本例においては、ラミネ
ート部材９によりマイナー・ループＮのヒステリ
シス損は低減できるが、メジヤー・ループＭにつ
いては効果が減少する。メジヤー・ループＭは、
ボイスコイル２のコイル全体による交流磁界であ
る。これらの従来例では、加工や結合ばかりでな
く磁界空隙の精度を出すのに手間がかかつてコス
トが高くつき、総じて熱や外乱による機械的安定
度が乏しい欠点がある。更に、実開昭49−134134
号公報にはポールピース５を含むヨーク７及びト
ツププレート４に音響的内部抵抗が多い焼結金属
を用いて機械振動系に相応した過渡振動波を減衰
させる様に構成した電気音響変換器の磁気回路が
示されているが、この磁気回路ではボイスコイル
２に流れる音声電流によつて生ずる交流磁束を打
ち消すことが出来ない。BACKGROUND TECHNOLOGY AND PROBLEMS In a dynamic electroacoustic transducer such as a dynamic speaker, when alternating current magnetic flux generated by an audio signal current flowing through a voice coil passes through a magnetic circuit member near the coil, an eddy current is generated. This eddy current causes distortion in the audio current flowing through the voice coil, resulting in sound distortion appearing in the audio radiated from the speaker. In conventional magnetic circuits, as a countermeasure against such current distortion, hysteresis loss is reduced by applying copper caps or copper plating to the pole pieces, or by inserting laminated silicon steel plates in a ring shape into the magnetic circuit. I was doing it. 1 and 2 are schematic sectional views showing such a conventional example. In Fig. 1, 1 is a diaphragm;
2 is a voice coil, 3 is a magnet (ferrite), 4
indicates the top plate, 5 indicates the ULM cut pole piece, 6 indicates the copper cap, and 7 indicates the yoke.
In this example, a copper cap 6 is attached to the pole piece 5.
It has a ULM cut. ULM is an abbreviation for ultra linear magnetic circuit, and the ULM cut has the same effect as the copper cap 6 to reduce current distortion. In FIG. 2, parts corresponding to those in FIG. 1 are given the same reference numerals. 9 is a laminated ring (laminate member),
M indicates a major loop in an alternating magnetic field, and N indicates a minor loop in an alternating magnetic field. The minor loop N is the alternating magnetic field due to the individual coils of the voice coil 2. In this example, the hysteresis loss of the minor loop N can be reduced by the laminate member 9, but the effect on the major loop M is reduced. Mezier loop M is
This is an alternating magnetic field generated by the entire coil of the voice coil 2. These conventional examples have the disadvantage that not only machining and coupling but also obtaining precision of the magnetic field gap is time consuming and costly, and mechanical stability against heat and external disturbances is generally poor. Furthermore, Utsukai Showa 49-134134
The publication describes a magnetic electroacoustic transducer configured to attenuate transient vibration waves corresponding to a mechanical vibration system by using sintered metal with high acoustic internal resistance for the yoke 7 including the pole piece 5 and the top plate 4. Although a circuit is shown, this magnetic circuit is unable to cancel out the alternating magnetic flux produced by the audio current flowing through the voice coil 2.
発明の目的
本発明は、上記の如き欠点がなく、しかも電流
歪みを低減しうるダイナミツク型電気音響変換器
の磁気回路を提供しようとするものである。OBJECTS OF THE INVENTION The present invention aims to provide a magnetic circuit for a dynamic electroacoustic transducer that does not have the above-mentioned drawbacks and can reduce current distortion.
発明の概要
本発明は、トツププレートと、磁石と、この磁
石が取り付けられる共にトツププレートに対し、
ボイスコイルが挿入される間〓を有して相対向す
るポールピースを有するヨークとからなる磁気回
路を具備してなる電気音響変換器の磁気回路にお
いて、この磁気回路の少なくともボイスコイルと
相対向する部分を焼結金属で形成し、この焼結金
属は磁気粉末材料の表面をこの磁気粉末材料の導
電率より高い導電率を有する非磁性の金属で覆つ
た粉末冶金材料で形成して、個々の焼結粉末がシ
ヨート・リングされボイスコイルに流れる音声電
流によつて発生する交流磁束を打ち消し、電流歪
みを低減できるようにしたものである。SUMMARY OF THE INVENTION The present invention provides a top plate, a magnet, and a top plate to which the magnet is attached.
In a magnetic circuit of an electroacoustic transducer, the magnetic circuit comprises a magnetic circuit including a yoke having a pole piece facing each other with a gap between which a voice coil is inserted. The parts are formed of sintered metal, the sintered metal being formed of a powder metallurgy material in which the surface of the magnetic powder material is covered with a non-magnetic metal having a higher conductivity than the magnetic powder material, and the individual The sintered powder is shot-ringed to cancel out the alternating current magnetic flux generated by the audio current flowing through the voice coil, thereby reducing current distortion.
実施例
第３図は、本発明の第１実施例を示す略断面図
である。図示のものは、ダイナミツク・スピーカ
の磁気回路のポールピース及びトツププレートに
上記の焼結金属を用いた例である。図において、
４′は上記の焼結金属で構成したトツププレート、
５′1は上記の焼結金属で構成したポールピース部
である。上記の焼結金属は、次のようにして製作
する。まず、粉末磁性材料（例えば鉄）をこれよ
り導電率が高く非磁性体の金属（例えば銅、銀）
で例えばメツキ等によりコートする。すなわち、
粉末冶金材料である磁性粉を１粒ごとに上記金属
層で被う。次に、このように金属コートされた粉
末冶金材料を焼結して作る。又は、粉末磁性材料
（例えば鉄）にこれより導電率が高く融点の低い
非磁性体金属（例えば銅）の粉末を混合してから
焼結してもよい。この場合は、融点の低い銅が先
に溶融して鉄の粉末をほぼ粒単位で銅コートす
る。Embodiment FIG. 3 is a schematic sectional view showing a first embodiment of the present invention. What is shown is an example in which the above-mentioned sintered metal is used for the pole piece and top plate of the magnetic circuit of a dynamic speaker. In the figure,
4' is a top plate made of the above sintered metal;
5'1 is a pole piece portion made of the above-mentioned sintered metal. The above sintered metal is manufactured as follows. First, a powdered magnetic material (e.g. iron) is mixed with a non-magnetic metal (e.g. copper, silver) with a higher conductivity than the powdered magnetic material (e.g. iron).
For example, it is coated by a method such as methuki. That is,
Each particle of magnetic powder, which is a powder metallurgy material, is covered with the metal layer. The metal-coated powder metallurgy material is then sintered. Alternatively, powder of a non-magnetic metal (for example, copper) having a higher conductivity and lower melting point may be mixed with a powdered magnetic material (for example, iron) and then sintered. In this case, the copper, which has a low melting point, is melted first and the iron powder is coated with the copper almost grain by grain.
このようにして製作した焼結磁性材でトツププ
レート４′及びポールピース部５′1を構成すると、
個々の焼結磁性粒子が上記銅キヤツプのようにシ
ヨート・リングされ１個の磁区単位となつて音声
電流により発生する交流磁束を打ち消す働きを生
じ、ヒステリシス損を低減する。これは、従来の
銅メツキ、銅キヤツプ、ULMカツトなどと同様
に電流歪みを低減する作用をする。また、ボイス
コイル２に対向している磁気回路の部分が磁性微
粒子のシヨート・リングされた構造であるため、
ボイスコイル２近傍のマイナー・ループＮに対し
ても充分に渦電流発生を低減させる働きがあり、
ポールピース部５′1やトツププレート４′も全体
的に同様にコートされた焼結金属から成つている
ので、メジヤー・ループＭに対しても同様な働き
があり、電流歪み低減効果が大である。 When the top plate 4' and the pole piece part 5'1 are constructed from the sintered magnetic material manufactured in this way,
The individual sintered magnetic particles are short-ringed like the copper cap described above and form a single magnetic domain unit, which acts to cancel out the alternating current magnetic flux generated by the audio current, thereby reducing hysteresis loss. This works to reduce current distortion in the same way as conventional copper plating, copper caps, ULM cuts, etc. In addition, since the part of the magnetic circuit facing the voice coil 2 has a short ring structure of magnetic particles,
It also works to sufficiently reduce eddy current generation in the minor loop N near the voice coil 2.
Since the pole piece portion 5'1 and the top plate 4' are made of sintered metal coated in the same way as a whole, they have a similar effect on the measurer loop M, and have a great effect of reducing current distortion. be.
第４〜第６図は、本発明の第２〜第４実施例を
示す略断面図である。第１〜第４実施例は、トツ
ププレートとポールピース部（又はポールピー
ス）が焼結金属より成る２ピース構成で、いずれ
も同様な作用効果を有する。これらの実施例にお
いて、ポールピース部は図示のように５′1から
５′2，５′3，５′4へと変形している。第６図の例
では、ヨークとポールピースが一体の焼結金属よ
り成り、５′4はそのポールピース部、７′はその
ヨーク部を示す。第７〜第８図は、本発明の第５
〜第６実施例を示す略断面図である。第５〜第６
実施例は、ポールピース５′2のみ又はポールピー
ス部５′4とヨーク部７′とが一体の焼結金属より
成る１ピース構成で、いわば簡略型である。これ
らの実施例においても、２ピース構成より程度は
やや落ちるが同様な効果が得られる。 4 to 6 are schematic sectional views showing second to fourth embodiments of the present invention. The first to fourth embodiments have a two-piece structure in which the top plate and the pole piece portion (or pole piece) are made of sintered metal, and all have similar effects. In these embodiments, the pole piece portions are modified from 5' 1 to 5' 2 , 5' 3 , and 5' 4 as shown. In the example shown in FIG. 6, the yoke and the pole piece are made of integral sintered metal, and 5'4 indicates the pole piece portion, and 7' indicates the yoke portion. 7 and 8 show the fifth embodiment of the present invention.
- It is a schematic sectional view showing a 6th example. 5th to 6th
The embodiment has a one-piece construction in which only the pole piece 5' 2 or the pole piece portion 5' 4 and the yoke portion 7' are made of integral sintered metal, so to speak, it is a simplified type. In these embodiments, similar effects can be obtained, although to a slightly lesser degree than in the two-piece configuration.
応用例
以上ダイナミツク・スピーカを例にとつて説明
したが、本発明がダイナミツク・マイクロホン等
あらゆるダイナミツク型電気音響変換器の磁気回
路に適用可能であることはいうまでもない。APPLICATION EXAMPLE Although the present invention has been explained using a dynamic speaker as an example, it goes without saying that the present invention is applicable to the magnetic circuit of any dynamic type electroacoustic transducer such as a dynamic microphone.
発明の効果
本発明によれば、焼結粉末が個々にシヨート・
リングされているため、ボイスコイルに流れる音
声電流によつて発生する交流磁束を打ち消し、コ
イルのインダクタンスを低減させ、電流歪みを低
減することができる。すなわち、ボイスコイル近
傍のマイナー・ループに対してだけでなく、メジ
ヤー・ループに対しても充分に渦電流発生を低減
するので、電流歪み低減の効果は大きい。また、
従来のものに比べ、磁気回路のエア・ギヤツプの
精度が出し易く、磁気回路全体の構成が簡単で加
工に手数を要せず量産性に優れている更に、磁気
回路を単に焼結材料で構成させたものに比べて焼
結された金属が磁性粉末材料の表面をこの磁性粉
末材料の導電率より高い導電率を有する非磁性体
の金属で覆つているので大なる磁束ループ及び小
なる磁束ループに対しても電流歪みや過電流の発
生を低減させることが出来る利点を有する。Effects of the Invention According to the present invention, the sintered powder is individually shot and
Because of the ring, it is possible to cancel the alternating current magnetic flux generated by the audio current flowing through the voice coil, reduce the inductance of the coil, and reduce current distortion. That is, the generation of eddy current is sufficiently reduced not only in the minor loop near the voice coil but also in the major loop, so the effect of reducing current distortion is large. Also,
Compared to conventional products, it is easier to achieve precision in the air gap of the magnetic circuit, and the overall structure of the magnetic circuit is simple and requires no processing effort, making it excellent for mass production.Furthermore, the magnetic circuit is simply constructed of sintered material. The sintered metal covers the surface of the magnetic powder material with a non-magnetic metal whose conductivity is higher than that of the magnetic powder material, resulting in a large magnetic flux loop and a small magnetic flux loop. It also has the advantage of being able to reduce the occurrence of current distortion and overcurrent.
第１及び第２図は従来例を示す略断面図、第３
〜第８図は本発明の各種実施例を示す略断面図で
ある。
４′……焼結金属より成るトツププレート、
５′1，５′2，５′3，５′4……焼結金属より成るポ
ールピース部又はポールピース、７′……焼結金
属より成るヨーク部。
1 and 2 are schematic sectional views showing the conventional example, and 3.
8 are schematic sectional views showing various embodiments of the present invention. 4'...Top plate made of sintered metal,
5' 1 , 5' 2 , 5' 3 , 5' 4 ... Pole piece part or pole piece made of sintered metal, 7'... Yoke part made of sintered metal.
Claims (1)
ププレートに対し、ボイスコイルが挿入される間
〓を有して相対向するポールピースを有するヨー
クとからなる磁気回路を具備してなる電気音響変
換器の磁気回路において、 上記磁気回路の少なくとも上記ボイスコイルと
相対向する部分を焼結金属で形成し、該焼結金属
は磁気粉末材料の表面を該磁気粉末材料の導電率
より高い導電率を有する非磁性体の金属で覆つた
粉末冶金材料で形成してなることを特徴とする電
気音響変換器の磁気回路。[Claims] 1. A yoke comprising: a top plate; a magnet; and a yoke having a pole piece to which the magnet is attached and which faces the top plate with a gap in between which a voice coil is inserted. In a magnetic circuit of an electroacoustic transducer comprising a magnetic circuit, at least a portion of the magnetic circuit facing the voice coil is formed of a sintered metal, and the sintered metal covers the surface of the magnetic powder material with the magnetic material. A magnetic circuit for an electroacoustic transducer, characterized in that it is formed of a powder metallurgy material covered with a non-magnetic metal having a conductivity higher than that of the powder material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13093282A JPS5921199A (en) | 1982-07-27 | 1982-07-27 | Magnetic circuit of electroacoustic transducer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13093282A JPS5921199A (en) | 1982-07-27 | 1982-07-27 | Magnetic circuit of electroacoustic transducer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5921199A JPS5921199A (en) | 1984-02-03 |
| JPH0560317B2 true JPH0560317B2 (en) | 1993-09-02 |
Family
ID=15046075
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13093282A Granted JPS5921199A (en) | 1982-07-27 | 1982-07-27 | Magnetic circuit of electroacoustic transducer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5921199A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006060333A (en) * | 2004-08-17 | 2006-03-02 | Pioneer Electronic Corp | Magnetic circuit for speaker, and speaker system |
| JP2007074378A (en) * | 2005-09-07 | 2007-03-22 | Pioneer Electronic Corp | Magnetic circuit for speaker device and speaker device |
| DK2705673T3 (en) | 2011-05-04 | 2015-10-19 | Dali As | Electromagnetic drive |
| JP5880166B2 (en) | 2012-03-13 | 2016-03-08 | 株式会社Ihi | Blanket installation method and blanket unit |
| WO2013140719A1 (en) | 2012-03-19 | 2013-09-26 | パナソニック株式会社 | Magnetic circuit for loudspeaker, and loudspeaker using same |
| KR102663543B1 (en) * | 2018-12-06 | 2024-05-03 | 현대자동차주식회사 | Yoke for speaker, Method form manufacturing the same And Speaker device including the same |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5132454U (en) * | 1974-08-31 | 1976-03-10 | ||
| JPS5228696A (en) * | 1975-08-29 | 1977-03-03 | Toshiba Corp | Resin-ferrite composition |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49134134U (en) * | 1973-03-20 | 1974-11-18 |
-
1982
- 1982-07-27 JP JP13093282A patent/JPS5921199A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5132454U (en) * | 1974-08-31 | 1976-03-10 | ||
| JPS5228696A (en) * | 1975-08-29 | 1977-03-03 | Toshiba Corp | Resin-ferrite composition |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5921199A (en) | 1984-02-03 |
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