JPH0614391A - Dust cap for loudspeaker - Google Patents

Abstract

PURPOSE:To obtain the dust cap which can be manufactured easily, and is light in weight and does not increase a mechanical impedance of a vibrating system, having moderate rigidity and vibration energy absorbing capability and also, having an action for suppressing abnormal vibration of a diaphragm, etc., by constituting the dust cap of a base material obtained by mixing and making a casein fiber and pulp. CONSTITUTION:This dust cap for a loudspeaker consists of a base material obtained by mixing and making a casein fiber and pulp. Also, it is desirable that the casein fiber is that which is obtained by drawing out a solution obtained by dissolving a milk casein in 10% alkali into a nitric acid coagulation bath from a spinnerret and coagulating it like a thread, and thereafter, letting it to pass through a formalin bath, as applying tension, and executing its unsolubilization treatment, and thereafter, executing hot air drying. In the figure, a full line and a dotted line show a characteristic of the loudspeaker using the embodiment dust cap, and a characteristic of the loudspeaker using a conventional example dust cap, respectively, and in a band of >=2kHz, a frequency characteristic of the embodiment shows a smooth characteristic in which a peak and a dip scarcely occurs.

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、各種の音響機器に使用
されるスピーカの振動板の中心近傍に装着されて、当該
スピーカの磁気空隙内に異物が侵入することを防止する
ダストキャップとその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust cap which is mounted in the vicinity of the center of a diaphragm of a speaker used in various kinds of audio equipment and prevents foreign matter from entering the magnetic gap of the speaker. It relates to a manufacturing method.

【０００２】[0002]

【従来の技術】周知のごとく、スピーカのダストキャッ
プは、本来は振動板の中心近傍に装着されて、当該スピ
ーカの磁気空隙内に異物が侵入することを防止する作用
を有するが、装着箇所は一般に、コーン振動板の中心孔
に結合接着されているボイスコイルボビンの上端部に接
着されるか、或いはコーン振動板の中心孔近傍の部位
に、中心孔とボイスコイルボビンとの結合部を覆うよう
にして装着されている。このうち、前者のボイスコイル
ボビンの上端部に接着される方式では、ボイスコイルボ
ビンの変形や釣鐘モードの振動を抑制し、又、後者のコ
ーン振動板に接着される方式では振動板の振動モードに
直接に影響を与え、いずれの場合も再生音の良否、即ち
スピーカの品質に関与する。2. Description of the Related Art As is well known, the dust cap of a speaker is originally attached near the center of a diaphragm to prevent foreign matter from entering the magnetic gap of the speaker, but the place of attachment is Generally, it is bonded to the upper end of the voice coil bobbin that is bonded and bonded to the center hole of the cone diaphragm, or the part near the center hole of the cone diaphragm is covered with the bonding part of the center hole and the voice coil bobbin. Have been installed. Among them, the former method of adhering to the upper end of the voice coil bobbin suppresses deformation of the voice coil bobbin and vibration of the bell mode, and the latter method of adhering to the cone diaphragm directly affects the vibration mode of the diaphragm. Influences the quality of the reproduced sound, that is, the quality of the speaker.

【０００３】この様なコーン振動板に接着されるダスト
キャップの材料としては、高剛性のもの、又は機械的な
内部損失が大きいもの、或いはこの両性質を適当に有す
るもの等、使用目的、要求される機能に応じて、金属、
合成樹脂、繊維質材料に賦形材として樹脂を含浸させた
もの、及びこれらの積層物等が用いられている。The material of the dust cap adhered to such a cone diaphragm is a material having high rigidity, a material having a large mechanical internal loss, or a material having both of these properties, the purpose of use and requirements. Metal, depending on the function
A synthetic resin, a fibrous material impregnated with a resin as a shaping material, and a laminate of these are used.

【０００４】[0004]

【発明が解決しようとする課題】上記構造を有する従来
の硬質のダストキャップに於ては、いずれも剛性と機械
的内部損失とのバランスを良好に保有することは困難
で、不自然な再生音となっているスピーカが多いという
解決すべき課題を抱えていた。In any of the conventional hard dust caps having the above structure, it is difficult to maintain a good balance between rigidity and mechanical internal loss, and it is difficult to reproduce unnatural sound. There was a problem to be solved that there are many speakers that have become.

【０００５】そこで本発明は、上記従来例の欠点を解消
し、製造が容易で、且つ軽量で振動系の機械インピーダ
ンスを増加させること無く、適度な剛性と振動エネルギ
ー吸収能力とを有して振動板等の異常振動も抑制する作
用を有するダストキャップ得ることで、優れた品質を保
持するスピーカを提供することを目的とする。Therefore, the present invention solves the above-mentioned drawbacks of the conventional example, is easy to manufacture, is light in weight, does not increase the mechanical impedance of the vibration system, has appropriate rigidity and vibration energy absorption capability, and vibrates. An object of the present invention is to provide a speaker that maintains excellent quality by obtaining a dust cap that also suppresses abnormal vibrations of plates and the like.

【０００６】[0006]

【課題を解決するための手段】上記目的を達成するため
の本発明に係るスピーカ用ダストキャップは、カゼイン
繊維とパルプとを混抄して得た基材からなるスピーカ用
ダストキャップである。更に上記カゼイン繊維が、牛乳
カゼインを１０％アルカリに溶解して得た溶液を紡糸口
金から硝酸凝固浴中に引出して糸状に凝固させた後、張
力をかけながらホルマリン浴中を通過させて不溶化処理
をした後熱風乾燥して得られるカゼイン繊維であること
を特徴とするスピーカ用ダストキャップである。[MEANS FOR SOLVING THE PROBLEMS] A speaker dust cap according to the present invention for achieving the above object is a speaker dust cap made of a base material obtained by mixing casein fiber and pulp. Further, the casein fiber is obtained by dissolving milk casein in 10% alkali and drawing the solution from the spinneret into a nitric acid coagulation bath to coagulate it into a filamentous shape, which is then passed through a formalin bath under tension to insolubilize it. A speaker dust cap, characterized in that it is casein fiber obtained by drying with hot air after drying.

【０００７】[0007]

【作用】本願のダストキャップにおいて、混抄されたカ
ゼイン繊維は植物性繊維と比較してその物性は、分子鎖
が屈曲しているという理由により弾力性があり、本願発
明のダストキャップと従来の繊維質材料に合成樹脂を含
浸した構成のダストキャップとの基材の物性値を比較し
て表１に示す様に、剛性はパルプ、即ち植物性繊維の存
在により従来例と大差なく、一方振動エネルギーの吸収
性の目安となるｔａｎδは従来例と比較して大きくなっ
ている。In the dust cap of the present application, the mixed casein fiber has elasticity as compared with the vegetable fiber due to the fact that the molecular chain is bent, and the dust cap of the present invention and the conventional fiber. As shown in Table 1 by comparing the physical properties of the base material with the dust cap in which the quality material is impregnated with the synthetic resin, the rigidity is not much different from the conventional example due to the presence of pulp, that is, plant fiber, while the vibration energy Tan δ, which is a measure of the absorptivity of, is larger than that of the conventional example.

【０００８】この結果として、適度な剛性と振動エネル
ギー吸収能力とを有して振動板等の異常振動も抑制する
作用を有し中高域での周波数特性が改善される。図１に
本願実施例のダストキャップを用いたスピーカの周波数
特性（実線）と従来例のダストキャップを用いたスピー
カの周波数特性（点線）を示す。As a result, the frequency characteristics in the middle and high frequencies are improved by having an appropriate rigidity and a vibration energy absorbing ability and also having an effect of suppressing abnormal vibration of the diaphragm and the like. FIG. 1 shows frequency characteristics of a speaker using a dust cap of the present embodiment (solid line) and frequency characteristics of a speaker using a dust cap of a conventional example (dotted line).

【０００９】[0009]

【表１】 [Table 1]

【００１０】[0010]

【実施例】牛乳に約５％の酢酸を加えて攪拌し、沈殿し
たカゼインを脱水乾燥して牛乳カゼインの粉末を得た。
この牛乳カゼインの粉末を１０％アルカリに溶解し、得
た溶液を、３mil の孔が多数穿設された紡糸口金に送
り、当該口金から引出されたフィラメントを１０ｍ／ｍ
ｉｎの速度で約０度Ｃの硝酸凝固浴を通過させて凝固さ
せた後、張力をかけながらホルマリン浴中を通過させて
不溶化処理をし、更に８０度Ｃの熱風で嵌挿させること
で不要な溶媒等を蒸発させてカゼイン繊維を得た。Example About 5% acetic acid was added to milk and stirred, and the precipitated casein was dehydrated and dried to obtain milk casein powder.
This milk casein powder was dissolved in 10% alkali and the resulting solution was sent to a spinneret with many 3 mil holes, and the filament drawn from the spinneret was 10 m / m.
After passing through a nitric acid coagulation bath of about 0 ° C at the speed of in to coagulate, pass through a formalin bath while applying tension to insolubilize, and then insert by hot air of 80 ° C to eliminate the need. Evaporating various solvents and the like, a casein fiber was obtained.

【００１１】未晒しのクラフトパルプ８０％、マニラ麻
パルプ２０％をビーターで叩解度２５度ＳＲになるまで
叩解し、その後に染色、サイズ処理をした。80% of unbleached kraft pulp and 20% of Manila hemp pulp were beaten with a beater until a beating degree of 25 ° SR, and then dyed and sized.

【００１２】一方、前記カゼイン繊維をホモジナイザー
で０．２〜２．０ミクロンに砕き、先程のパルプに対し
て重量％で５％混合し、全体の繊維濃度が０．０５％に
なるように調整し、ダストキャップ形状に抄造し、加熱
乾燥させて、公称１６cm口径スピーカ用の４０mm直径の
ダストキャップを得た。On the other hand, the casein fiber was crushed into 0.2 to 2.0 micron with a homogenizer and mixed with the pulp at 5% by weight to adjust the total fiber concentration to 0.05%. Then, the paper was formed into a dust cap shape and dried by heating to obtain a dust cap having a nominal diameter of 40 cm and a diameter of 40 mm for a speaker.

【００１３】又、従来例として比較のために上記パルプ
のみのダストキャップを作成し、同じパルプのみで抄造
したコーン振動板に、前記実施例のダストキャップ及び
従来例のダストキャップをつけてスピーカを組立てて周
波数特性を測定した。図１に夫々の周波数特性を示す。
図１に於て実線は実施例ダストキャップ使用のスピーカ
の特性、点線は従来例ダストキャップ使用のスピーカの
特性であって、両者を比較した場合、２ＫＨｚ以上の帯
域で実施例の周波数特性はピーク、ディップの少ない滑
らかな特性をしており、基材における表１に示した物性
値から予測される特徴を示している。For comparison, as a conventional example, a dust cap made of only the above pulp is prepared, and a cone diaphragm made of only the same pulp is attached with the dust cap of the embodiment and the dust cap of the conventional example to make a speaker. The assembled frequency characteristics were measured. FIG. 1 shows the respective frequency characteristics.
In FIG. 1, the solid line shows the characteristics of the speaker using the dust cap of the embodiment, and the dotted line shows the characteristics of the speaker using the dust cap of the conventional example. When the two are compared, the frequency characteristic of the embodiment peaks in the band of 2 KHz or more. , Has a smooth characteristic with little dip, and shows the characteristics predicted from the physical property values shown in Table 1 of the base material.

【００１４】以上、本発明に係るスピーカ用ダストキャ
ップとその製造方法について代表的と思われる実施例を
基に詳述したが、本発明によるダストキャップと、ポリ
オール、ポリイソシアネート等の原材料の種類、並びに
製造方法の実施態様は、上記実施例の構造に限定される
ものではなく、前記した特許請求の範囲に記載の構成要
件を具備し、本発明にいう作用を呈し、以下に述べる効
果を有する限りにおいて、適宜改変して実施しうるもの
である。The speaker dust cap according to the present invention and the method for producing the same have been described above in detail based on the examples considered to be typical. The dust cap according to the present invention and the types of raw materials such as polyol and polyisocyanate are In addition, the embodiment of the manufacturing method is not limited to the structure of the above-mentioned embodiment, and has the constituents described in the above-mentioned claims, exhibits the action referred to in the present invention, and has the effects described below. As long as it is possible, it can be appropriately modified and implemented.

【００１５】[0015]

【効果】本願発明に係るスピーカ用ダストキャップは以
下に述べる効果を有する。 (1) 本願のダストキャップは、従来のパルプにカゼイン
繊維を単に混抄するだけであるから従来の工程で製造出
来、極めて容易である。 (2) 原料であるカゼイン繊維は分子鎖が屈曲しており、
弾性が大きいので、基材の剛性は比較的高く、内部損失
が従来例より大きくなっているので、振動板の異常な分
割振動モードを抑制、変化させて、図１に示すように高
域での周波数特性が改善される。従って良好な性能で、
優れた再生音を有するスピーカを安価に提供することが
できる。[Effect] The speaker dust cap according to the present invention has the following effects. (1) The dust cap of the present application can be manufactured by the conventional process and is extremely easy because the casein fiber is simply mixed and mixed with the conventional pulp. (2) The molecular chain of casein fiber as a raw material is bent,
Since the elasticity is large, the rigidity of the base material is relatively high and the internal loss is larger than that of the conventional example. Therefore, by suppressing and changing the abnormal divided vibration mode of the diaphragm, as shown in FIG. The frequency characteristics of are improved. Therefore, with good performance,
A speaker having excellent reproduced sound can be provided at low cost.

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

【図１】本願実施例並びに従来例のダストキャップを用
いたスピーカの周波数特性図。FIG. 1 is a frequency characteristic diagram of a speaker using a dust cap according to an example of the present application and a conventional example.

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 カゼイン繊維とパルプとを混抄して得た
基材からなるスピーカ用ダストキャップ。1. A speaker dust cap comprising a base material obtained by mixing casein fibers and pulp. 【請求項２】 上記カゼイン繊維が、牛乳カゼインを１
０％アルカリに溶解して得た溶液を紡糸口金から硝酸凝
固浴中に引出して糸状に凝固させた後、張力をかけなが
らホルマリン浴中を通過させて不溶化処理をした後熱風
乾燥して得られるカゼイン繊維であることを特徴とする
請求項１記載のスピーカ用ダストキャップ。2. The casein fiber comprises 1 part of milk casein.
The solution obtained by dissolving it in 0% alkali is drawn out from the spinneret into a nitric acid coagulation bath to coagulate it into a filamentous form, which is then passed through a formalin bath under tension to insolubilize it and then dried with hot air. The speaker dust cap according to claim 1, wherein the dust cap is casein fiber.