JPH07236195A - Manufacture of top plate - Google Patents

Manufacture of top plate

Info

Publication number
JPH07236195A
JPH07236195A JP2515394A JP2515394A JPH07236195A JP H07236195 A JPH07236195 A JP H07236195A JP 2515394 A JP2515394 A JP 2515394A JP 2515394 A JP2515394 A JP 2515394A JP H07236195 A JPH07236195 A JP H07236195A
Authority
JP
Japan
Prior art keywords
top plate
thickness
diameter
inner diameter
executed
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.)
Granted
Application number
JP2515394A
Other languages
Japanese (ja)
Other versions
JP3232854B2 (en
Inventor
Kazuhiro Yamamoto
和浩 山本
Tetsuji Koura
哲司 小浦
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP02515394A priority Critical patent/JP3232854B2/en
Publication of JPH07236195A publication Critical patent/JPH07236195A/en
Application granted granted Critical
Publication of JP3232854B2 publication Critical patent/JP3232854B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Landscapes

  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Punching Or Piercing (AREA)

Abstract

PURPOSE:To obtain the manufacturing method of a top plate reduced in a secondary higher harmonic distortion to be used for a speaker magnetic circuit. CONSTITUTION:A stepped press where a center part is projected by a diameter being larger than a last inner diameter phie with the outer diameter of a piece 1 as a guide, where a lower hole 1a with the diameter being smaller than the last inner diameter phie is opened, is executed. Next, drawing is executed in a direction opposite to the above projecting direction by making the lower hole 1a open and, then, final pressing is executed. Thus, the thickness of a magnet adhearing part can be sufficiently made thick to such a degree that magnetic saturation is prevented and also the top plate 4 whose central thickness is larger than outer peripheral thickness and where R is not provided at the upper end part of a center hole 1b is realized. Since the magnetic flux density distribution is uniform and the uniform magnetic flux density range becomes larger, the driving force of a voice coil becomes vertically symmetrical even at the time of maximum amplitude so that the secondary higher harmonic distortion can be reduced as speaker performance.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は各種音響機器に使用され
るスピーカの中で、磁石などと組合せて使用されて外磁
型の磁気回路を形成するトッププレートの製造方法に関
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 top plate which is used in combination with a magnet or the like in a speaker used in various audio equipment to form an external magnet type magnetic circuit.

【0002】[0002]

【従来の技術】スピーカの磁気回路は大別すると外磁型
と内磁型に分類され、この外磁型の磁気回路において磁
気効率をより高める目的でトッププレートの中央部(磁
気ギャップを形成する部分)をトッププレートの厚みよ
り大きくする方法が採用されている。
2. Description of the Related Art The magnetic circuit of a speaker is roughly classified into an outer magnet type and an inner magnet type. In this outer magnet type magnetic circuit, a central portion (a magnetic gap is formed of a top plate for the purpose of further enhancing magnetic efficiency. The thickness of the top plate is larger than the thickness of the top plate.

【0003】図5は上記従来のトッププレートを用いて
構成されたスピーカ用の外磁型の磁気回路を示した断面
図であり、同図において10は上記従来のトッププレー
ト、11はリング状の磁石、12はセンターポール部1
2aを備えたボトムプレートを示し、これらの部品を積
層結合して磁気ギャップ13を形成した外磁型の磁気回
路を構成するものであった。
FIG. 5 is a cross-sectional view showing an external magnet type magnetic circuit for a speaker, which is constructed by using the above-mentioned conventional top plate. In FIG. 5, 10 is the conventional top plate and 11 is a ring shape. Magnet, 12 is the center pole part 1
The bottom plate provided with 2a is shown, and these components are laminated and combined to form an outer magnet type magnetic circuit in which the magnetic gap 13 is formed.

【0004】図6は上記従来のトッププレート10を製
造する製造方法を示したものであり、まず同図(a)に
示すように所定の厚さの板材から所望の外径の個片8を
打ち抜きプレスによって得る外径抜き工程と、同図
(b)に示すように個片8の中心部に最終内径より小さ
い径の下孔8aを開ける下孔開け工程と、同図(c)に
示すように下孔8aを開けた個片8の外径をガイドしな
がら下孔8aを拡大するように絞り加工し、所望の内径
寸法に形成された中心孔を備えた凸形のトッププレート
10を得るように製造されていた。
FIG. 6 shows a manufacturing method for manufacturing the above-described conventional top plate 10. First, as shown in FIG. 6A, a piece 8 having a desired outer diameter is made from a plate material having a predetermined thickness. An outer diameter punching step obtained by a punching press, a pilot hole drilling step of drilling a pilot hole 8a having a diameter smaller than the final inner diameter in the central portion of the individual piece 8 as shown in FIG. While the outer diameter of the individual piece 8 having the lower hole 8a is guided as described above, the lower hole 8a is drawn so as to be enlarged, and a convex top plate 10 having a central hole formed to have a desired inner diameter dimension is formed. Was manufactured to get.

【0005】[0005]

【発明が解決しようとする課題】しかしながら上記従来
のトッププレートの製造方法では、下孔8aを開けてか
ら絞り込む製造方法であるために、中心孔の上端部に使
用する材厚に相当する大きさのR部10aが発生するた
めに材厚を厚くできず、従って磁気飽和をおこし、図5
に示すセンターポール12aとの間に形成される磁気ギ
ャップ13で発生する磁束密度が計算通りに上がらず、
また磁束密度分布も不均一になり、この磁気ギャップ1
3にはめ込まれる図示しないボイスコイルの駆動力が上
下非対称となる。
However, in the above-mentioned conventional method of manufacturing the top plate, since the manufacturing method is such that the lower hole 8a is opened and then narrowed down, the size corresponding to the material thickness used for the upper end portion of the central hole is required. The thickness of the material cannot be increased due to the generation of the R portion 10a in FIG.
The magnetic flux density generated in the magnetic gap 13 formed between the center pole 12a and the center pole 12a does not rise as calculated,
Also, the magnetic flux density distribution becomes non-uniform, and this magnetic gap 1
The driving force of a voice coil (not shown) fitted in 3 becomes vertically asymmetric.

【0006】また、R部10aのため均一磁束密度範囲
が小さくなってスピーカの性能として第2次高調波歪み
が高くなるという課題を有していた。
Further, there is a problem that the uniform magnetic flux density range becomes small because of the R portion 10a and the second harmonic distortion becomes high as the performance of the speaker.

【0007】本発明は上記従来の問題点を解決するもの
で、中心孔の上端部に発生するR部を無くし、優れた性
能を有したトッププレートを得ることが可能なトッププ
レートの製造方法を提供することを目的とするものであ
る。
The present invention solves the above-mentioned conventional problems, and provides a method for manufacturing a top plate which eliminates the R portion generated at the upper end of the center hole and can obtain a top plate having excellent performance. It is intended to be provided.

【0008】[0008]

【課題を解決するための手段】上記課題を解決するため
に本発明によるトッププレートの製造方法は、所定の厚
さの板材から所望の外径の個片を打ち抜き、この個片の
中心部に最終内径より小さい径の下孔を開け、この下孔
を開けた個片の外径と下孔をガイドしながら最終内径よ
り大きい寸法に設定した中央部を突出させる段付きプレ
ス加工を行い、この突出させた中央部を下孔を拡大する
ようにして突出させた方向と逆方向に絞り加工すること
によって中央部の厚さを中央部以外の外周部の厚さより
厚くし、この中央部をプレス加工することにより所望の
内径寸法に形成された中心孔を備えた凸形のトッププレ
ートを形成する製造方法としたものである。
In order to solve the above-mentioned problems, a method of manufacturing a top plate according to the present invention is such that a piece having a desired outer diameter is punched out from a plate material having a predetermined thickness, and a center portion of the piece is punched out. A pilot hole with a diameter smaller than the final inner diameter is opened, and stepped press working is performed to guide the outer diameter of the individual piece with the pilot hole and the pilot hole to project the central part set to a dimension larger than the final inner diameter. The thickness of the central portion is made thicker than the thickness of the outer peripheral portion other than the central portion by drawing the central portion that is projected so as to enlarge the pilot hole in the direction opposite to the direction in which it is projected, and press this central portion. This is a manufacturing method for forming a convex top plate having a center hole formed to have a desired inner diameter by processing.

【0009】[0009]

【作用】この製造方法により、マグネットと貼り合わさ
れる部分となる基材の板厚を磁気飽和しない程度に十分
厚くすることができ、さらに中央部を凸形に加工した場
合でも中心孔の上端部にR部が発生しないトッププレー
トを得ることができ、このトッププレートを用いてスピ
ーカ用の磁気回路ならびにスピーカを組み立てた場合に
磁束密度分布も均一で、かつ均一磁束密度範囲が大きく
なるために最大振幅時においてもボイスコイルの駆動力
が上下対称となり、スピーカの性能として第2次高調波
歪みを低くすることができる。
With this manufacturing method, the thickness of the base material to be bonded to the magnet can be made thick enough not to cause magnetic saturation, and even when the central portion is processed into a convex shape, the upper end portion of the central hole is formed. It is possible to obtain a top plate in which no R part is generated, and when the magnetic circuit for the speaker and the speaker are assembled using this top plate, the magnetic flux density distribution is uniform, and the uniform magnetic flux density range becomes large. The driving force of the voice coil becomes vertically symmetrical even at the time of amplitude, and the second harmonic distortion can be reduced as the performance of the speaker.

【0010】[0010]

【実施例】以下、本発明の一実施例について図面を参照
しながら説明する。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

【0011】図1は同実施例によるトッププレートの製
造方法を示した製造工程図であり、同図(a)は所定の
厚さt1の板材を所望の外径φaの円形状の個片1に打
ち抜く外径抜き工程であり、上記外径φa、材厚t1は
磁気回路として使用するマグネットサイズにより磁気飽
和しないようにその寸法を決定するものである。
FIG. 1 is a manufacturing process diagram showing a method of manufacturing a top plate according to the embodiment, and FIG. 1 (a) is a circular piece 1 of a plate material having a predetermined thickness t1 and a desired outer diameter φa. The outer diameter φa and the material thickness t1 are determined so as not to cause magnetic saturation depending on the size of the magnet used as the magnetic circuit.

【0012】同図(b)は上記個片1をポンチ型にて絞
りを行うために下孔1aを開ける下孔開け工程であり、
外径φaをガイドとして下孔1a同心円状に開けるよう
にし、その下孔1aの外径φbは下孔1aを除く個片1
の体積が最終形状の体積に相当するように決定する。
FIG. 1 (b) shows a pilot hole forming step for drilling the pilot hole 1a for punching the individual piece 1 by a punch type.
The outer diameter φa is used as a guide to open the lower hole 1a concentrically, and the outer diameter φb of the lower hole 1a is the individual piece 1 excluding the lower hole 1a.
The volume of is determined so that it corresponds to the volume of the final shape.

【0013】同図(c)は上記下孔1aを開けた個片1
の中央部を突出させる段付きプレス工程であり、個片1
の外径と下孔1aをガイドしながら図中φcに示す中央
部を厚さt2だけ突出させて段付き形状にするもので、
図中のφdは最終の中心孔1bの径より大きくし、φc
はさらに上記φdより大きくした寸法に決定する。
FIG. 1C shows an individual piece 1 in which the above-mentioned pilot hole 1a is opened.
It is a stepped pressing process that projects the central part of the
While guiding the outer diameter and the pilot hole 1a, the central portion indicated by φc in the figure is projected by a thickness t2 to form a stepped shape.
Φd in the figure is made larger than the diameter of the final center hole 1b, and φc
Is determined to be larger than φd.

【0014】同図(d)は上記中央部を突出させた個片
1を絞り加工する絞り工程であり、下孔1aを拡大する
ようにして突出させた方向と逆方向に絞り加工すること
により、下孔1aの径をφbからφgまで拡大すると共
に、中央部の厚さを外周部の厚さt1より厚くなるよう
にしている。
FIG. 3D shows a drawing process for drawing the individual piece 1 having the central portion projected. By drawing the pilot hole 1a in a direction opposite to the direction in which it is projected so as to be enlarged. The diameter of the pilot hole 1a is increased from φb to φg, and the thickness of the central portion is made thicker than the thickness t1 of the outer peripheral portion.

【0015】同図(e)は上記絞り工程を終えた個片1
を所望の形状・寸法に仕上げる最終工程となる決め押し
工程であり、外径φa、内径φe、板厚t1、中央部の
板厚t3、突起部外径φfの凸形のトッププレート4を
得るようにしている。
FIG. 1E shows an individual piece 1 after the drawing process.
Is a final pressing step that is a final step of finishing the desired shape and dimensions, and obtains a convex top plate 4 having an outer diameter φa, an inner diameter φe, a plate thickness t1, a central plate thickness t3, and a protrusion outer diameter φf. I am trying.

【0016】なお、上記最終形状の中心孔1bの内径φ
eは、使用するボイスコイルの最大外径より大きくなる
よう決定し、また中央部の厚さ(磁極幅)t3は基材厚
t1より大きく、ボイスコイルの振幅長により決定し、
外径φfは磁気飽和しない程度により決定することが必
要な条件である。
The inner diameter φ of the center hole 1b having the final shape is
e is determined to be larger than the maximum outer diameter of the voice coil to be used, and the thickness (magnetic pole width) t3 of the central portion is larger than the base material thickness t1 and is determined by the amplitude length of the voice coil,
The outer diameter φf is a condition that needs to be determined depending on the degree of magnetic saturation.

【0017】図2(a),(b)は上記図1で説明した
トッププレートの製造工程の中で、絞り工程に使用する
プレス金型の上型2を示した平面図と断面図、また図3
(a),(b)は同決め押し工程で使用するプレス金型
の上型3を示した平面図と断面図であり、同図における
記号φa,φb,φe,φg,t2は全て図1の同記号
と対応するものである。
2 (a) and 2 (b) are a plan view and a cross-sectional view showing the upper die 2 of the press die used in the drawing step in the manufacturing process of the top plate described in FIG. Figure 3
(A) and (b) are a plan view and a sectional view showing an upper die 3 of a press die used in the same pressing step, and symbols φa, φb, φe, φg, and t2 in FIG. Corresponds to the same symbol.

【0018】また、図4は本発明によるトッププレート
の製造方法により得られたトッププレート4を用いて構
成したスピーカ用の磁気回路を示したものであり、同図
において4はトッププレート、5はリング状のマグネッ
ト、6はセンターポール部6aを有したボトムプレー
ト、7は磁気ギャップである。
FIG. 4 shows a magnetic circuit for a loudspeaker constructed by using the top plate 4 obtained by the method for manufacturing a top plate according to the present invention. In FIG. 4, 4 is a top plate and 5 is a top plate. A ring-shaped magnet, 6 is a bottom plate having a center pole portion 6a, and 7 is a magnetic gap.

【0019】このように本発明によるトッププレートの
製造方法は、基材厚となる外周部の厚さよりも中央部の
厚さを厚くした中心孔1bを備えた凸形のトッププレー
ト4を安価に得ることができ、さらに上記中心孔1bの
上端部にR部が発生することもないことから磁束密度分
布を均一にすることができ、スピーカの性能向上に大き
く貢献することができるものである。
As described above, in the method of manufacturing a top plate according to the present invention, the convex top plate 4 having the central hole 1b in which the thickness of the central portion is made thicker than the thickness of the outer peripheral portion which is the thickness of the base material is inexpensive. Further, since the R portion is not generated in the upper end portion of the center hole 1b, the magnetic flux density distribution can be made uniform, which can greatly contribute to the performance improvement of the speaker.

【0020】[0020]

【発明の効果】以上のように本発明によるトッププレー
トの製造方法は、マグネットと貼り合わせる部分となる
基材厚部の肉厚を磁気飽和しない程度に十分厚くするこ
とができ、さらに上記肉厚より中央部の肉厚を大きくし
た凸形形状で中心孔の上端部にRがつかないトッププレ
ートが実現できることから磁束密度分布も均一で、均一
磁束密度範囲が大きくなるため、最大振幅時においても
ボイスコイルの駆動力が上下対称となり、スピーカの性
能として第2次高調波歪みを低くすることが可能とな
る。
As described above, in the method for manufacturing a top plate according to the present invention, the thickness of the base material thick portion to be bonded to the magnet can be made thick enough not to cause magnetic saturation. Since a top plate that has a convex shape with a thicker central portion and does not have R at the upper end of the center hole can be realized, the magnetic flux density distribution is uniform and the uniform magnetic flux density range becomes large, so even at the maximum amplitude. The driving force of the voice coil becomes vertically symmetrical, and the second harmonic distortion can be reduced as the performance of the speaker.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例によるトッププレートの製造
方法を示す製造工程図
FIG. 1 is a manufacturing process diagram showing a method of manufacturing a top plate according to an embodiment of the present invention.

【図2】(a)同実施例の絞り工程に用いる金型の平面
図 (b)同正面断面図
FIG. 2A is a plan view of a mold used in the drawing step of the embodiment, and FIG. 2B is a front sectional view of the same.

【図3】(a)同実施例の決め押し工程に用いる金型の
平面図 (b)同正面断面図
FIG. 3 (a) is a plan view of a mold used in the final pressing step of the same embodiment. FIG.

【図4】同実施例により得られたトッププレートを用い
たスピーカ用磁気回路の断面図
FIG. 4 is a sectional view of a magnetic circuit for a speaker using a top plate obtained in the same example.

【図5】従来のトッププレートを用いたスピーカ用磁気
回路の断面図
FIG. 5 is a cross-sectional view of a conventional magnetic circuit for a speaker using a top plate.

【図6】従来のトッププレートの製造方法を示す製造工
程図
FIG. 6 is a manufacturing process diagram showing a conventional method for manufacturing a top plate.

【符号の説明】[Explanation of symbols]

1 個片 1a 下孔 1b 中心孔 2 金型 3 金型 4 トッププレート 5 マグネット 6 ボトムプレート 6a センターポール部 7 磁気ギャップ 1 piece 1a Lower hole 1b Center hole 2 Mold 3 Mold 4 Top plate 5 Magnet 6 Bottom plate 6a Center pole part 7 Magnetic gap

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 所定の厚さの板材から所望の外径の個片
を打ち抜き、この個片の中心部に最終内径より小さい径
の下孔を開け、この下孔を開けた個片の外径と下孔をガ
イドしながら最終内径より大きい寸法に設定した中央部
を突出させる段付きプレス加工を行い、この突出させた
中央部を下孔を拡大するようにして突出させた方向と逆
方向に絞り加工することによって中央部の厚さを中央部
以外の外周部の厚さより厚くし、この中央部をプレス加
工することにより所望の内径寸法に形成された中心孔を
備えた凸形のトッププレートを形成するトッププレート
の製造方法。
1. A piece having a desired outer diameter is punched out from a plate material having a predetermined thickness, a pilot hole having a diameter smaller than the final inner diameter is made at the center of the piece, and the outside of the piece having the pilot hole opened. Stepped press working is performed to guide the diameter and the pilot hole so that the central part set to a size larger than the final inner diameter is projected, and the projected central part is in the direction opposite to the direction in which the pilot hole is expanded to project. The thickness of the central part is made thicker than the thickness of the outer peripheral part other than the central part by drawing, and the central part is pressed to form a convex top with a central hole formed to the desired inner diameter. A method of manufacturing a top plate for forming a plate.
JP02515394A 1994-02-23 1994-02-23 Top plate manufacturing method Expired - Fee Related JP3232854B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP02515394A JP3232854B2 (en) 1994-02-23 1994-02-23 Top plate manufacturing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP02515394A JP3232854B2 (en) 1994-02-23 1994-02-23 Top plate manufacturing method

Publications (2)

Publication Number Publication Date
JPH07236195A true JPH07236195A (en) 1995-09-05
JP3232854B2 JP3232854B2 (en) 2001-11-26

Family

ID=12158077

Family Applications (1)

Application Number Title Priority Date Filing Date
JP02515394A Expired - Fee Related JP3232854B2 (en) 1994-02-23 1994-02-23 Top plate manufacturing method

Country Status (1)

Country Link
JP (1) JP3232854B2 (en)

Also Published As

Publication number Publication date
JP3232854B2 (en) 2001-11-26

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