JP3882769B2

JP3882769B2 - Dynamic speaker

Info

Publication number: JP3882769B2
Application number: JP2003056569A
Authority: JP
Inventors: 智今村; 猛平野; 知昭尾形; 敏勝桑波田
Original assignee: Victor Company of Japan Ltd
Current assignee: Victor Company of Japan Ltd
Priority date: 2003-03-04
Filing date: 2003-03-04
Publication date: 2007-02-21
Anticipated expiration: 2023-03-04
Also published as: JP2004266695A

Description

【０００１】
【発明の属する技術分野】
本発明は、オーディオ用スピーカの技術分野に属し、特に木製振動板を用いたコーン型やドーム型のダイナミック・スピーカに関する。
【０００２】
【従来の技術】
従来、図１２の断面図に示されるように、一般的に、略ラッパ状の振動板６１と、前記振動板６１を支持するエッジ６３と、ダンパー６４と、前記エッジ６３の外周部に接着されたガスケット６５と、フレーム６６と、前記振動板６１の中央の小径側開口部を覆う略ドーム状のキャップ６２と、振動板６１に駆動力を与えるボイスコイルボビン６７と、ボイスコイル６８と、マグネット６９と、トッププレート７０と、ポールピース７１と、バックプレート７２と、を備える構造のコーン型ダイナミック・スピーカ６０がフルレンジスピーカ若しくは低音域／中音域用スピーカとして汎用されている。
【０００３】
また、図１３の断面図に示されるように、一般的に、略ドーム状の振動板８１と、金網状のプロテクタ８２と、前記振動板８１を支持するエッジ８３と、フランジ８４と、トッププレート８５と、マグネット８６と、ボイスコイル８７と、ポールピース８８と、パッキン８９と、バックプレート７９を備える構造のドーム型ダイナミック・スピーカ８０が高音域用として一般に使用されている。
【０００４】
そして上記コーン型ダイナミック・スピーカ６０は例えば図１４の（ａ）正面図及び（ｂ）縦断面図に示されるような木製又はプラスチック製のキャビネット或いはエンクロージャと称される筺体９５内に取り付けられてスピーカ装置（スピーカユニットとも言う。）９０となる。
【０００５】
また、図１５の正面図に示されるように、前記ドーム型ダイナミック・スピーカ８０をツィータとして、図１６の（ａ）のネットワーク回路９２或いは（ｂ）のネットワーク回路９３を直列に挿入して低音域をカットし、これに前記コーン型ダイナミック・スピーカ６０をウーファとして組み合わせて筺体９５に取り付けた２ＷＡＹスピーカ装置１００もある。更には、スコーカ等を加えて３ＷＡＹ以上の構成としたスピーカ装置がある（図示せず）。
【０００６】
ダイナミック・スピーカの音響特性を決める主要素である前記略ラッパ状の振動板６１や前記略ドーム状の振動板８１の素材としては、紙パルプ製、プラスチック製又はアルミ等の金属製のものが殆どであった。これら従来の振動板は均一材料をプレス成形して成るので中心から半径方向の音の伝搬速度があらゆる方向で等しくなっている。したがって、必ず定在波が発生して共振ポイントを持ち、低周波領域での分割振動による音圧周波数特性の悪化を招き、しかも臨場感が欠落するという難点がある。また、紙パルプ製やプラスチック製の振動板は比較的大きな内部損失係数を有するものの、逆に剛性（ヤング率の大小）の点では劣り、音波伝搬速度は小さいので再生音の解像度にやや不満が残る。一方、アルミ等の金属製振動板は音波伝搬速度が高いものの内部損失係数が小さいので振幅の減衰が小さく、再生音の区切りが不明瞭、換言すると音のメリハリが悪いという難点がある。
【０００７】
上記のような一長一短のある既存素材の振動板を用いたダイナミック・スピーカに代わって、より自然に近い音を再現できる木製振動板を用いたダイナミック・スピーカの実現が望まれている。
【０００８】
即ち、木材の音波伝搬速度はその種類によって異なるが、一般に紙パルプよりも高く、さらに木目の方向とその直角方向とで異なり、木目方向（縦方向という。）の伝搬速度は速く、木目と直角方向（横方向という。）の伝搬速度は比較的遅いという異方性の伝搬性質を有している。また、木材は一般にスピーカ用振動板として適当な内部損失係数を有しており、且つ軽量で丈夫（高剛性）である。
【０００９】
したがって、木材そのものを素材とする木製振動板は定在波が発生しにくく共振ポイントが殆ど現れないので、分割振動が殆ど発生せず、音圧周波数特性の改善が期待されるとともに既存の紙パルプ製の振動板に比べて再生音の解像度向上や歯切れ良い音の向上が図れるのである。
【００１０】
上記木製振動板を用いたダイナミック・スピーカや木製振動板の製造方法として、例えば以下に挙げる公知文献に種々の提案が既に為されている。
【００１１】
下記［特許文献１］には、木質材の平板状薄板にポリエステル等のプラスチックを含浸硬化したＷＰＣ化処理木材の平面薄板を寸法安定性、内部摩擦、剛性などの特性において優れるスピーカ用平面振動板として用いたスピーカが提案されている。
【００１２】
下記［特許文献２］には、図１７の（ａ）、（ｂ）に示す製造手順のように、（ａ）一枚の木材薄板４から中心部に円弧状の切り欠き部１ａを有し、それに連続して扇形の切り欠き部１ｂを有する略ラッパ形状の展開形状である木材シート１を切り出し、（ｂ）木材シート１の扇形状の切り欠き部１ｂの両縁部ｂ１、ｂ２を糊代部分１ｃで互いに接着剤で重ね貼り合わせてラッパ状に形成し、その後にプレス成形してなるコーン振動板５が提案されている。
【００１３】
また、図１８の（ａ）、（ｂ）に示す製造手順のように、複数の木材小片シート２ａ、２ｂ・・・、２Ｌを接着剤で貼り合わせて（ｂ）のように略ラッパ状に形成し、その後にプレス成形してなるコーン振動板２が提案されている。また、上記コーン振動板１、２に物理的耐湿処理或いは化学的耐湿処理を加えたコーン振動板が提案されている。
【００１４】
下記［特許文献３］には、８０μｍ以下にスライスされた極薄木材シートと、その裏面に貼付された接着性の樹脂からなる不織布と、から構成される複合シートを、柔軟剤で柔軟化処理して複数枚積層し、さらに加熱及び加圧して円錐形状に成形した音響用振動板が提案されている。
【００１５】
下記［特許文献４］には、扇形形状に切断した平板状の木材薄板を成形時に割れ発生を防止するために高温度の蒸気、熱湯、又はｐＨ１０以上のアルカリ溶液でボイルした後、円錐状にプレス成形してなるコーン振動板が提案されている。
【００１６】
下記［特許文献５］には、１枚の木製シートの一面側に薄い不織布又は和紙を貼着した貼り合わせシートを作成し、これを潤滑剤入りの容器に含浸し、含浸された貼り合わせシートをプレス加熱成形して略ラッパ状に成形したスピーカ用振動板が提案されている。
【００１７】
下記［特許文献６］には、プレス成形時にしわや割れの生じない、かつ、経時変化の少ない木製のスピーカ用振動板を作るために、１枚の木製シートの一面側に薄い不織布又は和紙又はカーボンシートを貼着した貼り合わせシートを作成し、これを熱硬化性樹脂に含浸させた後、プレス加熱成形して略ラッパ状に成形してなるスピーカ用振動板が提案されている。
【００１８】
【特許文献１】
特開昭６２−２２４１９６号公報
【特許文献２】
特開平１−２８８１００号公報
【特許文献３】
特開平５−８３７９２号公報
【特許文献４】
特開平６−１７８３８６号公報
【特許文献５】
特開平１０−３０４４９２号公報
【特許文献６】
特開２０００−５９８８３号公報
【発明が解決しようとする課題】
木製振動板をダイナミック・スピーカに採用する場合において、特にポイントとなるのは、木材という素材の割れ易いという性質に如何に対処するか、また、成形性の悪さ、経年変化に如何に対処するかである。これらのハードルをクリアしない限り木材の特質を活かした優れた音響特性を備えるダイナミック・スピーカの実現は不可能である。
【００１９】
この点、［特許文献１］は対象が木製の平面振動板であって、木製であることの特質・利点は開示されているものの、略ラッパ状（コーン状）やドーム状に成形加工する際の問題点に関する技術的資料は何ら提供していない。
【００２０】
また、図１７及び図１８のような［特許文献２］の木製振動板の製造方法では、木材シート１若しくは木材小片シート２ａ、２ｂ・・が木の素材のみの状態で成形されているために、取り扱いの際やプレス成形時に割れが生じてしまったり、木材シートを互いに接着剤で貼り合わせるため、貼着部が障害となって所望の音響特性が得られないという問題や寸法精度が確保できないという問題がある。
【００２１】
また、［特許文献３］の極薄木材シートを複数枚積層してプレス成形する製造方法による木製振動板は、加工精度に難点があり、接着層が増えて接着剤の重量により振動板自体の重量が増加して所望の音響特性が得られず、多量の接着剤が音圧周波数特性にも悪影響を与えるので好ましくない。
【００２２】
また、［特許文献４］のようにプレス成形前に高温水蒸気やｐＨ１０以上のアルカリ溶液でのボイル処理が含まれる製造方法によって作られた木製振動板は、木材の中のリグニンという構成物質が取り去られてしまっているので木材の本来の特徴を発揮できず、音質に悪影響を与えることになる。
【００２３】
そして何よりも上記［特許文献２］、［特許文献３］、［特許文献４］の内容は製造工程での割れ、ひび、しわの発生といった不具合が多く、量産面での歩留まりが非常に悪くなって製品化が実現していないのである。
【００２４】
また、［特許文献５］や［特許文献６］における“張り”や“しなやかさ”を引き出すための潤滑剤の含浸及びしわや割れの発生防止、経時変化を防止するための熱硬化性樹脂の含浸後に、プレス加熱成形してなるスピーカ用振動板は、前記［特許文献１］〜［特許文献４］に比べて量産に向けた製造工程の優位性は認められるが、未だ十分な量産効率が達成されたとは言えず、実用化に向けてより一層の成形性の向上、延いては製造工程の歩留まりの向上が望まれる。
【００２５】
本発明は、上記事情に鑑みてなされたものであり、オーディオ用ダイナミック・スピーカとして、音響特性に優れ且つ量産に適する新規な木製振動板を用いたコーン型ダイナミック・スピーカ又はドーム型ダイナミック・スピーカを提供し、更には、それらを用いたスピーカ装置を提供するものである。
【００２６】
【課題を解決するための手段】
本発明は上記課題を解決するために、
（１）略ラッパ状の振動板と前記振動板の小径側開口部を覆う略ドーム状のキャップを備えたコーン型ダイナミック・スピーカにおいて、前記略ラッパ状の振動板が、１枚の木製シートの一面側に薄い不織布又は和紙を貼着して貼り合わせシートとし、前記貼り合わせシートの中心部に頂点が至る略Ｖ字状の切り込みを設け、前記切り込みを設けた貼り合わせシートに水分を与えて軟化させるとともに貼り合わせシート中に水分を保持する作用を有する潤滑剤を含ませ、前記潤滑剤が含まされた貼り合わせシートは１次プレス加熱成形によって前記略Ｖ字状の切り込みの縁部同士が重ね合わせられて略ラッパ状に仮成形され、仮成形の後に乾燥され、乾燥後に熱硬化性樹脂が含まされ、前記熱硬化性樹脂が半乾き状態になるまで５０℃〜６０℃の乾燥温度で略１〜１０分間乾燥が行われて半乾燥され、前記熱硬化性樹脂の半乾き状態で２次プレス加熱成形され、前記２次プレス加熱成形の後に少なくとも防湿剤が塗布され、前記防湿剤の塗布された貼り合わせシートに対してボイスコイル用の中心孔抜きと外形抜きを行って振動板としての所定寸法形状に成形してなる木製振動板であることを特徴とするコーン型ダイナミック・スピーカを提供する。
（２）略ラッパ状の振動板と前記振動板の小径側開口部を覆う略ドーム状のキャップを備えたコーン型ダイナミック・スピーカにおいて、前記略ドーム状のキャップが、１枚の木製シートの一面側に薄い不織布又は和紙を貼着して貼り合わせシートとし、前記貼り合わせシートに水分を与えて軟化させるとともに貼り合わせシート中に水分を保持する作用を有する潤滑剤を含ませ、前記潤滑剤が含まされた貼り合わせシートは１次プレス加熱成形によって略ドーム状に仮成形され、仮成形の後に乾燥され、乾燥後に熱硬化性樹脂が含まされ、前記熱硬化性樹脂が半乾き状態になるまで５０℃〜６０℃の乾燥温度で略１〜１０分間乾燥が行われて半乾燥され、前記熱硬化性樹脂の半乾き状態で２次プレス加熱成形され、前記２次プレス加熱成形の後に少なくとも防湿剤が塗布され、前記防湿剤の塗布された貼り合わせシートの外形抜きを行って略ドーム形状のキャップとしての所定寸法形状に成形してなるキャップであることを特徴とするコーン型ダイナミック・スピーカを提供する。
（３）前記（２）に記載のコーン型ダイナミック・スピーカにおいて、略ドーム状のキャップの素材となる木製シートの一面側に貼る薄い不織布又は和紙は厚さ０．０２〜０．３０ｍｍであり、貼り合わせシートは前記不織布又は和紙の繊維方向と木製シートの木目が略直角になるように貼り合わせてあることを特徴とするコーン型ダイナミック・スピーカを提供する。
（４）前記（２）に記載のコーン型ダイナミック・スピーカにおいて、略ドーム状のキャップの素材となる木製シートは、木目に沿った縦方向の音波の伝搬速度が４．５〜６．０ｋｍ／秒の範囲内であり、且つ内部損失係数が０．０２〜０．０３の範囲にある無垢材から切り出されたものであることを特徴とするコーン型ダイナミック・スピーカを提供する。
（５）前記（１）に記載のコーン型ダイナミック・スピーカにおいて、略ラッパ状の振動板の素材となる木製シートは、木目に沿った縦方向の音波の伝搬速度が４．５〜６．０ｋｍ／秒の範囲内であり、且つ内部損失係数が０．０２〜０．０３の範囲にある無垢材から切り出されたものであることを特徴とするコーン型ダイナミック・スピーカを提供する。
（６）略ラッパ状の振動板と前記振動板の小径側開口部を覆う略ドーム状のキャップを備え、前記振動板と前記キャップに磁気回路の磁力に基づき振動するボイスコイルの振動を伝達するように構成されているコーン型ダイナミック・スピーカにおいて、前記略ラッパ状の振動板が、１枚の木製シートの一面側に薄い不織布又は和紙を貼着して貼り合わせシートとし、前記貼り合わせシートの中心部に頂点が至る略Ｖ字状の切り込みを設け、前記切り込みを設けた貼り合わせシートに水分を与えて軟化させるとともに貼り合わせシート中に水分を保持する作用を有する潤滑剤を含ませ、前記潤滑剤が含まされた貼り合わせシートは１次プレス加熱成形によって前記略Ｖ字状の切り込みの縁部同士が重ね合わせられて略ラッパ状に仮成形され、仮成形の後に乾燥され、乾燥後に熱硬化性樹脂が含まされ、前記熱硬化性樹脂が半乾き状態になるまで５０℃〜６０℃の乾燥温度で略１〜１０分間乾燥が行われて半乾燥され、前記熱硬化性樹脂の半乾き状態で２次プレス加熱成形され、前記２次プレス加熱成形の後に少なくとも防湿剤が塗布され、前記防湿剤の塗布された貼り合わせシートに対してボイスコイル用の中心孔抜きと外形抜きを行って振動板としての所定寸法形状に成形してなる振動板であり、前記略ドーム状のキャップが、１枚の木製シートの一面側に薄い不織布又は和紙を貼着して貼り合わせシートとし、前記貼り合わせシートに水分を与えて軟化させるとともに貼り合わせシート中に水分を保持する作用を有する潤滑剤を含ませ、前記潤滑剤が含まされた貼り合わせシートは１次プレス加熱成形によって略ドーム状に仮成形され、仮成形の後に乾燥され、乾燥後に熱硬化性樹脂が含まされ、前記熱硬化性樹脂が半乾き状態になるまで５０℃〜６０℃の乾燥温度で略１〜１０分間乾燥が行われて半乾燥され、前記熱硬化性樹脂の半乾き状態で２次プレス加熱成形され、前記２次プレス加熱成形の後に少なくとも防湿剤が塗布され、前記防湿剤の塗布された貼り合わせシートの外形抜きを行ってドーム状のキャップとしての所定寸法形状に成形してなるキャップであることを特徴とするコーン型ダイナミック・スピーカを提供する。
（７）前記（６）に記載のコーン型ダイナミック・スピーカを筺体に取り付けて成ることを特徴とするスピーカ装置を提供する。
（８）略ドーム状の振動板を備えるドーム型ダイナミック・スピーカにおいて、前記略ドーム状の振動板が、１枚の木製シートの一面側に薄い不織布又は和紙を貼着して貼り合わせシートとし、前記貼り合わせシートに水分を与えて軟化させるとともに貼り合わせシート中に水分を保持する作用を有する潤滑剤を含ませ、前記潤滑剤が含まされた貼り合わせシートは１次プレス加熱成形によって略ドーム状に仮成形され、仮成形の後に乾燥され、乾燥後に熱硬化性樹脂が含まされ、前記熱硬化性樹脂が半乾き状態になるまで５０℃〜６０℃の乾燥温度で略１〜１０分間乾燥が行われて半乾燥され、前記熱硬化性樹脂の半乾き状態で２次プレス加熱成形され、前記２次プレス加熱成形の後に少なくとも防湿剤が塗布され、前記防湿剤の塗布された貼り合わせシートの外形抜きを行って振動板としての所定寸法形状に成形してなる振動板であることを特徴とするドーム型ダイナミック・スピーカを提供する。
【００２７】
【発明の実施の形態】
本発明に係るダイナミック・スピーカ及びスピーカ装置の実施の形態について、本発明の主構成要素である新規な木製振動板を主体に図面に基づいて説明する。
【００２８】
図１は本発明に係るコーン型ダイナミック・スピーカに用いられる木製振動板の製造工程フロー図である。図２、図３及び図４は前記コーン型ダイナミック・スピーカの木製振動板の製造工程フローにおける各加工状態を示す模式図である。図５は本発明に係るドーム型ダイナミック・スピーカに用いられている木製振動板の製造工程フローである。図６、図７及び図８は前記ドーム型ダイナミック・スピーカの木製振動板の製造工程フローにおける各加工状態を示す模式図である。図９は本発明に係るダイナミック・スピーカの構造を示す側面図である。図１０は本発明に係るコーン型ダイナミック・スピーカとドーム型ダイナミック・スピーカを筺体に取り付けて成るスピーカ装置（２ＷＡＹスピーカ）の音響特性（音圧周波数特性、インピーダンス、歪み特性）を示す実測グラフである。図１１は木製振動板の素材となりうる各種木材の有する内部損失係数と音伝搬速度（縦方向）についての関係を従来の材料であるアルミと紙と共に表したグラフである。
【００２９】
以下、本発明のダイナミック・スピーカに使用される木製振動板の製造方法について詳述する。
【００３０】
先ず、木製振動板の部材として、例えば選択された木材の丸太からロータリー方式により削り出し用刃で円周方向から薄く剥がし、実際に振動板となる成形部分よりも大きめの適当な矩形形状又は円形／楕円形状に切断して柾目の厚さ０．１〜０．９ｍｍの木製シートを準備する。
【００３１】
ここで、本発明のダイナミック・スピーカで使用する木製振動板の上記木製シートに適する木材について考察すると、図１０の各種木材の有する内部損失係数と音伝搬速度（縦方向）についての関係を従来の材料であるアルミと紙と共に表したグラフ及び各種木材の密度、ヤング率、音速、内部損失係数（ｔａｎδ）を表した下記［表１］から判るように、概ね合板を（Ｇ点、Ｈ点、Ｉ点、Ｊ点）除く木材（無垢材）が適度な内部損失係数と高い音伝搬速度を有する優れた素材となり得ることが判る。特に、カバ（Ａ点）やブナ（Ｃ点）が最適であることが判る。
【００３２】
【表１】

なお、図１０中のＡ点はカバ（無垢材）であり、以下、Ｂ点シナ（無垢材）、Ｃ点ブナ（無垢材）、Ｄ点オーク（無垢材）、Ｅ点チェリー（無垢材）、Ｆ点スプルース（無垢材）、Ｇ点シナ合板（共芯）、Ｈ点ラワン合板、Ｉ点ＭＦＤ、Ｊ点パーティクルボードである。
【００３３】
次に、本発明に係るコーン型ダイナミック・スピーカに用いられる略ラッパ状の木製振動板の製造手順を図１の（ａ）から（ｊ）までの製造工程フロー及び図２、図３の対応する（ａ）から（ｊ）までの各加工状態を示す模式図に従って説明する。
【００３４】
第１の実施の形態の製造工程は、図１に示されるように木製シートに対する（ａ）〜（ｊ）までの１０工程で構成され、（ａ）貼り合わせ、（ｂ）Ｖ字状切り込み、（ｃ）潤滑剤含浸、（ｄ）１次プレス、（ｅ）乾燥、（ｆ）熱硬化性樹脂含浸、（ｇ）半乾燥、（ｈ）２次プレス、（ｉ）防湿剤塗布、（ｊ）中心・外形抜きの順に行われて略ラッパ状の木製振動板の完成となる。
【００３５】
上記各工程の詳細内容を以下順に説明する。
工程（ａ）・・・０．ｌｍｍ〜０．９ｍｍ厚（好ましくは０．３ｍｍ程度）の木製シート１０の一面側に、接着剤により略０．０２〜０．３０ｍｍ厚の不織布又は和紙１３を貼り合わせて貼り合わせシート１５を作成する。上記木製シート１０の厚さは成形性と音響特性及びダイナミック・スピーカの口径を考慮した上での振動板として適正な厚さであり、上記不織布又は和紙１３の厚さ０．０２〜０．３０ｍｍの範囲は音響特性に与える影響と木製シート１０の補強という作用効果の兼ね合いで決まる適正な範囲である。また、ここにいう不織布はカーボン材その他の合成樹脂からなる周知材料である。なお、前記不織布又は和紙１３の繊維方向と木製シート１０の木目方向とが略直角になるように重ねて貼り合わせるようにすれば、取り扱い上非常に木目方向に沿って割れ易い木製シート１０の飛躍的な強度向上が図れるので好ましい。上記不織布又は和紙１３を貼り合わせた一面側が完成した木製振動板の背面側となる。
工程（ｂ）・・・貼り合わせシート１５に対して、中心部に頂点が至る略Ｖ字状の切り込み１１とその頂点近傍に小穴１２とを設ける。前記切り込み１１は、貼り合わせシート１５の木目方向（矢印ｆ）に概ね沿って設ける。
工程（ｃ）・・・Ｖ字状の切り込みをした前記貼り合わせシート１５が軟化するように、貼り合わせシート１５の中に浸透して水分を与え且つ水分を保持する作用のある潤滑剤１６の液中に５〜６０分浸し、十分に含浸させる。
【００３６】
これは後の１次プレス加熱成形を実施する時に割れを未然に防ぎ、歩留まり良く仮成形するためである。本発明者の研究によれば、前記潤滑剤１６としては、単なる水若しくはアルカリ水溶液ではなく、糖類を溶解させた水溶液が適する。工程（ｄ）・・・ヒータ３３を各々備えた上型３１と下型３２の金型構成のプレス装置Ｐ１によって、潤滑剤１６を含浸させた貼り合わせシート１５の前記Ｖ字状の切り込み１１の両縁部１１ａ、１１ｂを互いに重ね合わせて略ラッパ状になるように貼り合わせシート１５の成形部分以外の外周部分を掛止具等を利用して保持した状態で１次プレス加熱成形（仮成形）する。ここで１次プレス加熱成形の設定条件は、プレス圧力が略１〜１０Ｋｇ、金型温度は上型３１が略８０〜１５０℃、下型３２が略１００〜２００℃、プレス時間が略２〜６０秒である。この１次プレス加熱成形（仮成形）で貼り合わせシート１５は略ラッパ状の形状が維持される。
工程（ｅ）・・・乾燥炉（５０〜６０℃）に略１０〜３０分間入れて完全乾燥を行なう。
工程（ｆ）・・・乾燥後の仮成形された貼り合わせシート１５を熱硬化性樹脂１７液中に略３０分〜１８０分浸し、十分に含浸させる。上記熱硬化性樹脂１７としてはフェノール樹脂が適する。
工程（ｇ）・・・熱硬化性樹脂１７の含浸直後に後工程の２次プレスを実施すると、金型に熱硬化性樹脂１７が貼り付いてしまい、プレス後に貼り合わせシート１５を剥がす時に割れや引きちぎれが発生して歩留まりが極度に低下する。逆に完全に乾燥させると成形性が悪くなって割れやすくなる。これを防止するために、乾燥炉（５０℃〜６０℃）に略１〜１０分間入れて熱硬化性樹脂１７を半乾燥状態（指で触ってもべたつかない程度の所謂“指触乾燥状態”である。）にする。
工程（ｈ）・・・前記工程（ｄ）と同様の周知の構成のプレス装置Ｐ２によって、含浸させた熱硬化性樹脂１７が半乾燥状態の貼り合わせシート１５を再度プレス加熱成形する。ここで２次プレス加熱成形の設定条件は、プレス圧力が略２０〜４０Ｋｇ、金型温度は上型３４が略８０〜２００℃、下型３５が略１００〜２００℃、プレス時間が略１０〜１００秒である。成形後は揮発成分が蒸散して成形形状が略ラッパ形状に安定した貼り合わせシート１５となる。ここに、前記熱硬化性樹脂１７は貼り合わせシート１５の重ね合わせ部分の接着剤の役目も担っているのである。
工程（ｉ）・・・２次プレス後の貼り合わせシート１５の表裏両面に筆による塗布若しくはジャブ漬けにより防湿剤１８を塗布して自然乾燥又は乾燥炉に入れて完全乾燥を行なう。前記防湿剤１８としては、例えばポリイソシアネートとポリエステルポリオールを混合したものを用いる。この防湿剤の塗布によって木製振動板の湿度による経年変化が抑えられて寿命の長いダイナミック・スピーカが実現される。
工程（ｊ）・・・上記のように防湿処理されたプレス加熱成形後の貼り合わせシート１５にボイスコイル用の中心孔２５と外形抜きが施されて所定の振動板形状に加工されてコーン型ダイナミック・スピーカの木製振動板３０が完成する。
【００３７】
上記木製振動板３０の木目は中心から径方向を見ると種々の角度をもつことになり、殆どの方向において同一の音伝搬速度は存在せず、定在波が発生しにくく共振ポイントが殆ど発生しないので、分割振動が抑えられる。
【００３８】
また、上記木製振動板３０は前述のように木製であることに基づく優れた音響特性を備えるとともに特殊な潤滑剤や熱硬化性樹脂の含浸及び一連のプレス加熱成形工程の工夫等により、しわや割れが無く、湿度による経時変化が小さく寿命の長い木目の美しい仕上がりとなっている。そして特筆すべきは、その製造工程は簡単でありながら非常に歩留まり良く、製造コストを抑えた量産性に優れたものとなっている。
【００３９】
上記完成した略ラッパ状の木製振動板３０は、図９の（ａ）の断面図に示されるように、従来のコーン型ダイナミック・スピーカ６０と同様、ダンパー６４、エッジ６３、ボイスコイル６８等と組み合わされてコーン型ダイナミック・スピーカ３８となる。
【００４０】
次に、上記略ラッパ状の木製振動板３０の他の製造方法の形態として、図１における工程（ｈ）の２次プレスのみの工程に代えて、図１の破線枠で囲まれた（ｈ１）２次プレス、（ｈ２）離型剤含浸、（ｈ３）乾燥、（ｈ４）３次プレスという工程（図４の模式図を参照）を工程（ｉ）防湿剤塗布の前に行うと歩留まりが向上し、成形加工の仕上がり度も高まるので、好ましい木製振動板の製造方法といえる。ここに、工程（ｈ１）の２次プレス加熱成形のプレス装置Ｐ２の設定条件は、プレス圧力が略２０〜４０Ｋｇ、金型温度は上型３４が略８０〜２００℃、下型３５が略１００〜２００℃、プレス時間が略２〜３０秒であり、工程（ｈ４）の３次プレス加熱成形のプレス装置Ｐ３の設定条件は、プレス圧力が略２０〜４０Ｋｇ、金型温度は上型３６が略８０〜２００℃、下型３７が略１００〜２００℃、プレス時間が略２〜６０秒である。また、離型剤４６としてはシリコン（ケイ素）を用いる。
【００４１】
次に、本発明に係るドーム型ダイナミック・スピーカに用いる略ドーム状の木製振動板の製造方法について述べる。
【００４２】
略ドーム状の木製振動板の製造方法は、図５の製造工程フローから判るように、木製シートに対する（ａ）〜（ｉ）までの９工程で構成され、（ａ）貼り合わせ、（ｂ）潤滑剤含浸、（ｃ）１次プレス、（ｄ）乾燥、（ｅ）熱硬化性樹脂含浸、（ｆ）半乾燥、（ｇ）２次プレス、（ｈ）防湿剤塗布、（ｉ）中心・外形抜きの順に行われて略ドーム状の木製振動板４０の完成となる。
【００４３】
上記製造フローは前述のコーン型ダイナミック・スピーカの略ラッパ状の木製振動板３０における図１の製造工程フローの工程（ｂ）の貼り合わせシート１５に略Ｖ字状の切り込み１１を設ける工程が無い点以外、他の工程は同等である。Ｖ字状の切り込み工程が無く且つ工程（ｄ）の１次プレスを行う際に略ラッパ状に保持する必要がない点で、作業性は一層簡単であるといえる。
【００４４】
勿論、上記略ドーム状の木製振動板４０においても他の製造方法の形態として、図５における工程（ｇ）の２次プレスのみの工程に代えて、図５の破線枠で囲まれた（ｇ１）２次プレス、（ｇ２）離型剤含浸、（ｇ３）乾燥、（ｇ４）３次プレスという工程（図８の模式図を参照）を工程（ｈ）防湿剤塗布の前に行うことで歩留まりが向上し、成形加工の仕上がり度も高まるので、好ましい略ドーム状の木製振動板の製造方法といえる。なお、図８における工程（ｇ２）の離型剤４６はシリコンであることは前記と同様であり、工程（ｇ４）の３次プレス装置Ｐ３の上型４８、下型４７の貼り合わせシート１５に対するプレス条件も同様である。
【００４５】
上記略ドーム状の木製振動板４０も前述の略ラッパ状の木製振動板３０と同じく木製であることに基づく優れた音響特性等を備えた木目の美しい仕上がりとなっている。そしてその製造工程は簡単でありながら非常に歩留まり良く、製造コストを抑えた量産性に優れたものとなっている。
【００４６】
上記完成した略ドーム状の木製振動板４０は、図９の（ｂ）の断面図に示されるように、従来のドーム型ダイナミック・スピーカ８０と同様、エッジ８３、ボイスコイル８７等と組み合わされてドーム型ダイナミック・スピーカ５０となるところで、上記略ドーム状の木製振動板４０はその形状・寸法が従来のコーン型ダイナミック・スピーカ６０のキャップ６２の形状・寸法と極めて類似することから、上記略ドーム状の木製振動板４０を図９の（ａ）の本発明に係るコーン型ダイナミック・スピーカ３８の木製キャップ３９として利用することができる。この構成によれば、コーン型ダイナミック・スピーカ３８の前面側は木目の美しい木製振動板３０とその中心部の木製キャップ３９が組み合わされて、見た目に美しく高級感、統一感のあるスピーカとなる。
【００４７】
次に、前記コーン型ダイナミック・スピーカ３８は例えば従来と同様に図１４の（ａ）正面図及び（ｂ）縦断面図に示されるような木製又はプラスチック製の筺体９５内に取り付けられてスピーカ装置となる。また、ドーム型ダイナミック・スピーカ５０に図１６のネットワーク回路９２又は９３を挿入して高域周波数再生専用のツィータとし、それ以外の帯域を再生するウーファとして前記コーン型ダイナミック・スピーカ３８を組み合わせて筺体９５に取り付けることで、図１５のような２ＷＡＹスピーカ装置とすることもできる。更には、３ＷＡＹスピーカ装置や同軸２ＷＡＹスピーカシステムも可能である。
【００４８】
このようにウーファ及びツィータの振動板に前記木製振動板３０、４０を用いる構成として、全ての振動板が木製となることで、音質の向上が図られることになる。なお、ウーファの周波数特性がクロスオーバー周波数付近で暴れるようならば、図１６の（ｃ）のような高域カット用のネットワーク回路９９を挿入する。
【００４９】
以上のように、本発明のダイナミック・スピーカは、従来と同様に１個構成のスピーカ装置に限らず、種々の口径、ドーム型、コーン型の組み合わせ等で自然で優れた音響特性を備えるスピーカ装置を構成することができる。
【００５０】
本発明者の研究によれば、上記各実施の形態のダイナミック・スピーカにおいて、明確に従来の紙パルプ製の振動板やアルミ製の振動板に比べて再生音の解像度向上や歯切れ良い音の向上が得られるのは、縦方向伝搬速度が４．５〜６．０ｋｍ／秒、横方向伝搬速度が２．０〜４．５ｋｍ／秒の範囲の木材を選定した場合であった。
【００５１】
特に顕著に音質向上が実感されるのは、縦方向伝搬速度が４．５〜６．０ｋｍ／秒、横方向伝搬速度が２．０〜２．５ｋｍ／秒の範囲で、内部損失係数が０．０２〜０．０３の範囲の木材を選択して振動板に用いた場合であり、カバ（無垢材）が最良であった。
【００５２】
勿論、本発明のスピーカ用振動板は、カバのみならず、ブナ、オーク、チェリー、シナ等の他の材木を適用することもできる。
【００５３】
実際に、図１６の（ｂ）のネットワーク回路９３（容量Ｃ２＝１．５μＦ、インダクタＬ１＝０．１８ｍＨ）を用いた本発明のドーム型ダイナミック・スピーカ５０とコーン型ダイナミック・スピーカ３８（口径８ｃｍ程度）との組み合わせによる２ＷＡＹスピーカ装置では、図１０の実測グラフに示される優れた音圧、インピーダンス、歪みの各周波数特性を得ている。
【００５４】
【発明の効果】
上記のように本発明に係るダイナミック・スピーカはドーム型或いはコーン型の何れにおいてもその構成要素である振動板として、１枚の木材を素材とし、従来の紙パルプ製振動板の製造過程に存在するような化学薬品での蒸解や木材繊維の叩解処理が加えられていない木製振動板を用いているので音質劣化が無く、木製振動板であるが故の自然な振動による生音に迫る再生音が得られる。
【００５５】
木製振動板がプレス加熱成形時のしわや割れの発生が防止されて、仕上がりの良い均一なプレス加熱成形品となっており、変形や割れといった経時変化が少ない。
【００５６】
軽くて丈夫な略ラッパ状の木製振動板を用いたコーン型ダイナミック・スピーカなので、ウーファからフルレンジスピーカまで全ての帯域に対応したダイナミック・スピーカとなる。
【００５７】
また、ドーム型ダイナミック・スピーカはツィータとして、コーン型ダイナミック・スピーカはウーファとして組み合わせて種々の形態のスピーカ装置とすることができる。
【００５８】
また、既存の製造工程が利用でき、歩留まりが良好で量産性に優れていて、安価供給が実現できる。
【００５９】
さらに、コーン型ダイナミック・スピーカでは、振動板の表面或いは振動板とキャップの表面に自然の木目が表れているので、高級感、統一感のある外観体裁となる。
【００６０】
スピーカ装置に関しては、エンクロージャ（キャビネット）のみでなく、スピーカユニットの全ての振動板が木製振動板とできるので、本物の木目デザインで統一することが可能になり高級感溢れる外観が提供できる。
【図面の簡単な説明】
【図１】本発明に係るコーン型ダイナミック・スピーカに用いられる木製振動板の製造工程フロー図である。
【図２】前記コーン型ダイナミック・スピーカの木製振動板の製造工程フローの各加工状態（前半）を示す模式図である。
【図３】前記製造工程フローの各加工状態（後半）を示す模式図である。
【図４】前記製造工程フローの破線枠内の追加フローの加工状態を示す模式図である。
【図５】本発明に係るドーム型ダイナミック・スピーカに用いられている木製振動板の製造工程フローである。
【図６】前記ドーム型ダイナミック・スピーカの木製振動板の製造工程フローにおける各加工状態（前半）を示す模式図である。
【図７】前記製造工程フローの各加工状態（後半）を示す模式図である。
【図８】前記製造工程フローの破線枠内の追加フローの加工状態を示す模式図である。
【図９】（ａ）は本発明に係るコーン型ダイナミック・スピーカの断面図であり、（ｂ）は本発明に係るドーム型ダイナミック・スピーカの断面図である。
【図１０】本発明に係る２ＷＡＹスピーカ装置の音圧、インピーダンス、歪みの周波数特性の実測グラフである。
【図１１】各種木材の有する内部損失係数と音伝搬速度（縦方向）についての関係を従来の材料であるアルミと紙と共に表したグラフである。
【図１２】コーン型ダイナミック・スピーカの構造を示す断面図である。
【図１３】ドーム型ダイナミック・スピーカの構造を示す断面図である。
【図１４】コーン型ダイナミック・スピーカを筺体に取り付けて成るスピーカ装置の（ａ）正面図、（ｂ）断面図である。
【図１５】コーン型ダイナミック・スピーカとドーム型ダイナミック・スピーカを筺体に取り付けて成る２ＷＡＹスピーカ装置の正面図である。
【図１６】（ａ）、（ｂ）はツィータのネットワーク回路、（ｃ）はウーファの高域カット用ネットワーク回路である。
【図１７】従来の木製振動板の製造手順を示す図である。
【図１８】従来の木製振動板の製造手順を示す図である。
【符号の説明】
１０木製シート
１１略Ｖ字状の切り込み
１１ａ、１１ｂ両縁部
１２小穴
１３不織布又は和紙
１５貼り合わせシート
１６水分を与え且つ水分を保持する作用のある潤滑剤
１７熱硬化性樹脂
１８防湿剤
２５中心孔
３０略ラッパ状の木製振動板
３１、３４、３６、４３、４５、４８上型
３３ヒータ
３２、３５、３７、４２、４４、４７下型
４６離型剤
３８、６０コーン型ダイナミック・スピーカ
３９木製キャップ
４０略ドーム状の木製振動板
５０、８０ドーム型ダイナミック・スピーカ
６１略ラッパ状の振動板
６２キャップ
６３、８３エッジ
６４ダンパー
６８、８７ボイスコイル
８１略ドーム状の振動板
９５筺体
９０スピーカ装置
９２、９３、９９ネットワーク回路
１００２ＷＡＹスピーカ装置
Ｐ１、Ｐ２、Ｐ３プレス装置[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of audio speakers, and particularly relates to a cone-type or dome-type dynamic speaker using a wooden diaphragm.
[0002]
[Prior art]
Conventionally, as shown in the sectional view of FIG. 12, generally, a substantially trumpet-shaped diaphragm 61, an edge 63 that supports the diaphragm 61, a damper 64, and an outer peripheral portion of the edge 63 are bonded. A gasket 65, a frame 66, a substantially dome-shaped cap 62 that covers the opening on the small diameter side in the center of the diaphragm 61, a voice coil bobbin 67 that applies driving force to the diaphragm 61, a voice coil 68, and a magnet 69. A cone-type dynamic speaker 60 having a structure including a top plate 70, a pole piece 71, and a back plate 72 is widely used as a full range speaker or a low / mid range speaker.
[0003]
Further, as shown in the cross-sectional view of FIG. 13, generally, a substantially dome-shaped diaphragm 81, a wire mesh-shaped protector 82, an edge 83 that supports the diaphragm 81, a flange 84, and a top plate 85, a magnet 86, a voice coil 87, a pole piece 88, a packing 89, and a dome-type dynamic speaker 80 having a structure including a back plate 79 are generally used for a high sound range.
[0004]
The cone type dynamic speaker 60 is attached to a housing 95 called a wooden or plastic cabinet or enclosure as shown in FIG. 14 (a) front view and (b) longitudinal sectional view. Device (also referred to as a speaker unit) 90.
[0005]
As shown in the front view of FIG. 15, the network circuit 92 of FIG. 16A or the network circuit 93 of FIG. There is also a 2WAY speaker device 100 in which the cone type dynamic speaker 60 is combined as a woofer and attached to the housing 95. Furthermore, there is a speaker device (not shown) having a configuration of 3 WAY or more by adding a squawker or the like.
[0006]
As the material of the substantially trumpet-shaped diaphragm 61 or the substantially dome-shaped diaphragm 81 which is a main element that determines the acoustic characteristics of the dynamic speaker, most are made of metal such as paper pulp, plastic or aluminum. Met. Since these conventional diaphragms are formed by pressing a uniform material, the sound propagation speed in the radial direction from the center is the same in all directions. Therefore, a standing wave always occurs and has a resonance point. This causes a problem that sound pressure frequency characteristics are deteriorated due to divided vibrations in a low frequency region, and a sense of reality is lost. Paper pulp and plastic diaphragms have a relatively large internal loss factor, but on the contrary, they are inferior in terms of rigidity (Young's modulus), and the sound propagation speed is low, so the resolution of the reproduced sound is somewhat unsatisfactory. Remain. On the other hand, a metal diaphragm such as aluminum has a high sound wave propagation speed, but has a small internal loss coefficient, so that the attenuation of the amplitude is small, the division of the reproduced sound is unclear, in other words, the sound is not sharp.
[0007]
In place of the dynamic speaker using the existing diaphragm having the advantages and disadvantages as described above, it is desired to realize a dynamic speaker using a wooden diaphragm that can reproduce a more natural sound.
[0008]
That is, the sound wave propagation speed of wood varies depending on the type, but is generally higher than that of paper pulp. Further, the propagation speed differs in the direction of the wood grain and the direction perpendicular thereto, and the propagation speed in the wood grain direction (referred to as the vertical direction) is fast and perpendicular to the grain The propagation velocity in the direction (referred to as the transverse direction) has an anisotropic propagation property that it is relatively slow. In addition, wood generally has an appropriate internal loss factor as a speaker diaphragm, and is light and strong (high rigidity).
[0009]
Therefore, a wooden diaphragm made of wood itself is less likely to generate standing waves, so there are almost no resonance points. Therefore, divided vibration hardly occurs, and improvement in sound pressure frequency characteristics is expected and existing paper pulp is expected. Compared to a diaphragm made of steel, the resolution of the reproduced sound can be improved and the sound can be improved crisply.
[0010]
Various proposals have already been made, for example, in the following publicly known literatures as methods for producing dynamic speakers and wooden diaphragms using the above-described wooden diaphragm.
[0011]
In the following [Patent Document 1], a flat plate made of WPC made by impregnating and hardening a plastic material such as polyester on a flat plate made of wood material is a flat plate diaphragm for a speaker excellent in characteristics such as dimensional stability, internal friction, and rigidity. The speaker used as is proposed.
[0012]
[Patent Document 2] includes (a) an arc-shaped cutout portion 1a in the center from one piece of wood sheet 4 as in the manufacturing procedure shown in FIGS. 17 (a) and 17 (b). Then, a wood sheet 1 having a substantially trumpet shape having a fan-shaped cutout portion 1b is cut out continuously, and (b) both edges b1 and b2 of the fan-shaped cutout portion 1b of the wood sheet 1 are glued. A cone diaphragm 5 has been proposed which is formed in a trumpet shape by being overlapped and bonded to each other at an allowance portion 1c and then press-molded.
[0013]
Further, like the manufacturing procedure shown in FIGS. 18A and 18B, a plurality of small pieces of

wood

2a, 2b,... A cone diaphragm 2 formed and then press-molded has been proposed. Further, there has been proposed a cone diaphragm obtained by adding physical moisture resistance treatment or chemical moisture resistance treatment to the

cone diaphragms

1 and 2.
[0014]
In the following [Patent Document 3], a composite sheet composed of an ultrathin wood sheet sliced to 80 μm or less and a non-woven fabric made of an adhesive resin attached to the back surface thereof is softened with a softening agent. Thus, there has been proposed an acoustic diaphragm in which a plurality of sheets are stacked and further heated and pressed to form a conical shape.
[0015]
In the following [Patent Document 4], a flat timber sheet cut into a fan shape is boiled with high-temperature steam, hot water, or an alkaline solution having a pH of 10 or more to prevent cracking during molding, and then conical. A cone diaphragm formed by press molding has been proposed.
[0016]
In the following [Patent Document 5], a laminated sheet in which a thin non-woven fabric or Japanese paper is pasted on one side of one wooden sheet is prepared, and this is impregnated into a container containing a lubricant, and the impregnated laminated sheet There has been proposed a loudspeaker diaphragm that is press-heated and formed into a substantially trumpet shape.
[0017]
The following [Patent Document 6] describes a thin non-woven fabric or Japanese paper on one side of one wooden sheet in order to produce a wooden speaker diaphragm that does not cause wrinkles or cracks during press molding and has little change over time. There has been proposed a speaker diaphragm in which a bonded sheet with a carbon sheet attached is prepared, impregnated with a thermosetting resin, and then press-heat molded to form a substantially trumpet shape.
[0018]
[Patent Document 1]
JP-A-62-2224196
[Patent Document 2]
JP-A-1-288100
[Patent Document 3]
JP-A-5-83792
[Patent Document 4]
JP-A-6-178386
[Patent Document 5]
JP-A-10-304492
[Patent Document 6]
JP 2000-59883 A
[Problems to be solved by the invention]
When adopting a wooden diaphragm for a dynamic speaker, the key point is how to deal with the nature of the material of wood, which is easy to break, and how to deal with poor formability and aging. It is. Unless these hurdles are cleared, it is impossible to realize a dynamic speaker having excellent acoustic characteristics utilizing the characteristics of wood.
[0019]
In this regard, [Patent Document 1] is a flat vibration plate made of wood, and the characteristics and advantages of being a wood are disclosed, but when forming into a substantially trumpet shape (cone shape) or dome shape. It does not provide any technical data on the problem.
[0020]
In addition, in the method for manufacturing a wooden diaphragm of [Patent Document 2] as shown in FIGS. 17 and 18, the wood sheet 1 or the

wood piece sheets

2a, 2b,... , Cracking occurs during handling or press molding, or wood sheets are bonded together with an adhesive, so the problem of the desired acoustic properties not being obtained due to the sticking part being obstructed and dimensional accuracy cannot be ensured There is a problem.
[0021]
Further, the wooden diaphragm produced by the manufacturing method in which a plurality of ultra-thin wood sheets of [Patent Document 3] are laminated and press-molded has a difficulty in processing accuracy, and the number of adhesive layers increases and the weight of the adhesive increases the vibration of the diaphragm itself. The weight is increased and desired acoustic characteristics cannot be obtained, and a large amount of adhesive adversely affects sound pressure frequency characteristics, which is not preferable.
[0022]
Further, as in [Patent Document 4], a wooden diaphragm made by a manufacturing method that includes boil treatment with high-temperature steam or an alkaline solution having a pH of 10 or more before press molding takes a component called lignin in the wood. Since it has been left, the original characteristics of wood cannot be demonstrated, and the sound quality will be adversely affected.
[0023]
Above all, the contents of [Patent Document 2], [Patent Document 3], and [Patent Document 4] have many problems such as cracks, cracks and wrinkles in the manufacturing process, and the yield in mass production becomes very poor. Therefore, commercialization has not been realized.
[0024]
In addition, in [Patent Document 5] and [Patent Document 6], a thermosetting resin is used to impregnate a lubricant for extracting “tension” and “flexibility”, prevent wrinkles and cracks from occurring, and prevent change over time. The speaker diaphragm formed by press-heating after impregnation has an advantage in the manufacturing process for mass production as compared with [Patent Document 1] to [Patent Document 4], but still has sufficient mass production efficiency. It cannot be said that it has been achieved, and it is desired to further improve the moldability for practical use, and further improve the yield of the manufacturing process.
[0025]
The present invention has been made in view of the above circumstances, and as a dynamic speaker for audio, a cone type dynamic speaker or a dome type dynamic speaker using a new wooden diaphragm having excellent acoustic characteristics and suitable for mass production is provided. Furthermore, the present invention provides a speaker device using them.
[0026]
[Means for Solving the Problems]
In order to solve the above problems, the present invention
(1) In a cone-type dynamic speaker comprising a substantially trumpet-shaped diaphragm and a substantially dome-shaped cap that covers the small-diameter side opening of the diaphragm, the substantially trumpet-shaped diaphragm is made of one wooden sheet. Applying a thin non-woven fabric or Japanese paper on one side to form a laminated sheet, providing a substantially V-shaped cut leading to the center of the laminated sheet, and applying moisture to the laminated sheet provided with the cut A lubricant having an action of softening and holding moisture in the bonded sheet is included, and the bonded sheet containing the lubricant has the edges of the substantially V-shaped cuts formed by primary press thermoforming. Overlaid and temporarily formed into a substantially trumpet shape, dried after temporary molding, and after drying, contains a thermosetting resin, until the thermosetting resin is in a semi-dry state Drying is performed at a drying temperature of 50 ° C. to 60 ° C. for about 1 to 10 minutes. Semi-dried, heat-molded in a semi-dry state of the thermosetting resin, secondary press-heat-molded, and after the secondary press heat-molding, at least a moisture-proofing agent is applied. There is provided a cone type dynamic speaker characterized in that it is a wooden diaphragm formed by performing a center hole for a coil and an outer shape to be molded into a predetermined size shape as a diaphragm.
(2) In a cone-type dynamic speaker comprising a substantially trumpet-shaped diaphragm and a substantially dome-shaped cap that covers the small-diameter side opening of the diaphragm, the substantially dome-shaped cap is a surface of one wooden sheet. A thin non-woven fabric or Japanese paper is attached to the side to form a laminated sheet, and a lubricant having an action of retaining moisture in the laminated sheet is included while softening the laminated sheet with moisture, and the lubricant is The contained laminated sheet is temporarily formed into a substantially dome shape by primary press thermoforming, dried after temporary forming, and after drying, contains a thermosetting resin, until the thermosetting resin is in a semi-dry state. Drying is performed at a drying temperature of 50 ° C. to 60 ° C. for about 1 to 10 minutes. Semi-dried and heat-molded in a semi-dry state of the thermosetting resin, and subjected to secondary press thermoforming. After the secondary press thermoforming, at least a moisture-proofing agent is applied, and an outer shape of the laminated sheet coated with the moisture-proofing agent is removed. A cone-type dynamic speaker is provided which is a cap formed to have a predetermined dimensional shape as a substantially dome-shaped cap.
(3) In the cone-type dynamic speaker according to (2), the thin nonwoven fabric or Japanese paper to be attached to one side of the wooden sheet that is the material of the substantially dome-shaped cap has a thickness of 0.02 to 0.30 mm. The bonded sheet is provided so that the fiber direction of the nonwoven fabric or Japanese paper and the wood grain of the wooden sheet are approximately perpendicular to each other.
(4) In the cone-type dynamic speaker according to (2), the wooden sheet that is the material of the substantially dome-shaped cap has a propagation speed of acoustic waves in the vertical direction along the grain of 4.5 to 6.0 km / There is provided a cone type dynamic speaker characterized by being cut from a solid material having an internal loss coefficient in a range of 0.02 to 0.03.
(5) In the cone-type dynamic speaker described in (1) above, the wooden sheet that is the material of the substantially trumpet-shaped diaphragm has a propagation speed of sound waves in the vertical direction along the grain of 4.5 to 6.0 km. A cone-type dynamic speaker characterized by being cut out from a solid material having an internal loss coefficient in the range of 0.02 to 0.03.
(6) A substantially trumpet-shaped diaphragm and a substantially dome-shaped cap that covers the small-diameter opening of the diaphragm are provided, and the vibration of the voice coil that vibrates based on the magnetic force of the magnetic circuit is transmitted to the diaphragm and the cap. In the cone-type dynamic speaker configured as described above, the substantially trumpet-shaped diaphragm is attached to one side of a single wooden sheet with a thin non-woven fabric or Japanese paper as a laminated sheet, A substantially V-shaped notch having a vertex at the center is provided, and a lubricant having an action of retaining moisture in the bonded sheet is added to the bonded sheet provided with the notch and softened by adding moisture, The bonded sheet containing the lubricant is temporarily formed into a substantially trumpet shape by overlapping the edges of the substantially V-shaped cuts by primary press thermoforming, Dried after the molding, the thermosetting resin is included after drying, until the thermosetting resin is half-dried state Drying is performed at a drying temperature of 50 ° C. to 60 ° C. for about 1 to 10 minutes. Semi-dried, heat-molded in a semi-dry state of the thermosetting resin, secondary press-heat-molded, and after the secondary press heat-molding, at least a moisture-proofing agent is applied. A diaphragm formed by removing a center hole for a coil and an outer shape to form a predetermined shape as a diaphragm. The substantially dome-shaped cap is a thin non-woven fabric or Japanese paper on one side of one wooden sheet. To form a laminated sheet, and to add a moisture to the laminated sheet to soften it and to contain a lubricant having an action of retaining moisture, the laminated sheet containing the lubricant Is temporarily molded into a substantially dome shape by primary press thermoforming, dried after temporary molding, and after drying, contains a thermosetting resin, until the thermosetting resin is in a semi-dry state Drying is performed at a drying temperature of 50 ° C. to 60 ° C. for about 1 to 10 minutes. Semi-dried and heat-molded in a semi-dry state of the thermosetting resin, and subjected to secondary press thermoforming. After the secondary press thermoforming, at least a moisture-proofing agent is applied, and the laminated sheet to which the moisture-proofing agent is applied is removed. A cone-type dynamic speaker is provided which is a cap formed by molding into a predetermined dimensional shape as a dome-shaped cap.
(7) Provided is a speaker device comprising the cone type dynamic speaker according to (6) attached to a housing.
(8) In the dome-type dynamic speaker provided with a substantially dome-shaped diaphragm, the substantially dome-shaped diaphragm is a laminated sheet obtained by sticking a thin non-woven fabric or Japanese paper on one side of one wooden sheet, The bonded sheet is softened by applying moisture, and the bonded sheet contains a lubricant having a function of retaining moisture, and the bonded sheet containing the lubricant is substantially dome-shaped by primary press thermoforming. Until the thermosetting resin is in a semi-dried state. Drying is performed at a drying temperature of 50 ° C. to 60 ° C. for about 1 to 10 minutes. Semi-dried and heat-molded in a semi-dry state of the thermosetting resin, and subjected to secondary press thermoforming. After the secondary press thermoforming, at least a moisture-proofing agent is applied, and the laminated sheet to which the moisture-proofing agent is applied is removed A dome-type dynamic speaker is provided which is a diaphragm formed by being molded into a predetermined size and shape as a diaphragm.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a dynamic speaker and a speaker device according to the present invention will be described with reference to the drawings, focusing on a novel wooden diaphragm that is a main component of the present invention.
[0028]
FIG. 1 is a manufacturing process flow chart of a wooden diaphragm used in a cone type dynamic speaker according to the present invention. 2, 3 and 4 are schematic views showing respective processing states in the manufacturing process flow of the wooden diaphragm of the cone type dynamic speaker. FIG. 5 is a manufacturing process flow of the wooden diaphragm used in the dome type dynamic speaker according to the present invention. 6, 7 and 8 are schematic views showing each processing state in the manufacturing process flow of the wooden diaphragm of the dome type dynamic speaker. FIG. 9 is a side view showing the structure of the dynamic speaker according to the present invention. FIG. 10 is an actual measurement graph showing acoustic characteristics (sound pressure frequency characteristics, impedance, distortion characteristics) of a speaker device (2WAY speaker) in which a cone type dynamic speaker and a dome type dynamic speaker according to the present invention are attached to a housing. . FIG. 11 is a graph showing the relationship between the internal loss coefficient and the sound propagation speed (longitudinal direction) of various kinds of wood that can be used as a material for the wooden diaphragm together with aluminum and paper as conventional materials.
[0029]
Hereinafter, the manufacturing method of the wooden diaphragm used for the dynamic speaker of the present invention will be described in detail.
[0030]
First, as a member of a wooden diaphragm, for example, a selected wooden log is peeled thinly from the circumferential direction with a cutting blade by a rotary method, and a suitable rectangular shape or circle larger than the molded part that actually becomes the diaphragm / Cut into an elliptical shape to prepare a wooden sheet having a thickness of 0.1 to 0.9 mm.
[0031]
Here, considering wood suitable for the wooden sheet of the wooden diaphragm used in the dynamic speaker of the present invention, the relationship between the internal loss coefficient and the sound propagation speed (longitudinal direction) of the various types of wood in FIG. As can be seen from the following [Table 1] representing the density, Young's modulus, sound velocity, and internal loss factor (tan δ) of various woods with the aluminum and paper materials, the plywood (G point, H point, It can be seen that wood (solid material) excluding point I and point J can be an excellent material having an appropriate internal loss coefficient and high sound propagation speed. In particular, it is found that hip (point A) and beech (point C) are optimal.
[0032]
[Table 1]

In addition, A point in FIG. 10 is a hip (solid wood), and below, B point China (solid wood), C point beech (solid wood), D point oak (solid wood), E point cherry (solid wood) F point spruce (solid material), G point China plywood (core), H point lauan plywood, I point MFD, J point particle board.
[0033]
Next, the manufacturing procedure of the substantially trumpet-shaped wooden diaphragm used for the cone type dynamic speaker according to the present invention corresponds to the manufacturing process flow from (a) to (j) of FIG. 1 and FIGS. 2 and 3. A description will be given in accordance with schematic diagrams showing each processing state from (a) to (j).
[0034]
The manufacturing process of 1st Embodiment is comprised by 10 process to (a)-(j) with respect to a wooden sheet, as shown in FIG. 1, (a) bonding, (b) V-shaped cutting, (C) Lubricant impregnation, (d) primary press, (e) drying, (f) thermosetting resin impregnation, (g) semi-drying, (h) secondary press, (i) moisture-proofing agent application, (j ) This is done in the order of center and outer shape, and a substantially trumpet-shaped wooden diaphragm is completed.
[0035]
The detailed contents of the above steps will be described in the following order.
Step (a) ... 0. A non-woven fabric or Japanese paper 13 having a thickness of approximately 0.02 to 0.30 mm is bonded to one side of a wooden sheet 10 having a thickness of 1 mm to 0.9 mm (preferably about 0.3 mm) with an adhesive to create a bonded sheet 15. To do. The thickness of the wooden sheet 10 is an appropriate thickness as a diaphragm considering the moldability, acoustic characteristics, and the diameter of the dynamic speaker, and the thickness of the nonwoven fabric or Japanese paper 13 is 0.02 to 0.30 mm. The range is an appropriate range determined by the balance between the effect on the acoustic characteristics and the effect of reinforcing the wooden sheet 10. The non-woven fabric here is a well-known material made of a carbon material or other synthetic resin. If the fiber direction of the non-woven fabric or Japanese paper 13 and the grain direction of the wooden sheet 10 are overlapped and bonded so as to be substantially perpendicular, the leap of the wooden sheet 10 that is very easy to break along the grain direction in handling. This is preferable because the strength can be improved. One side where the nonwoven fabric or Japanese paper 13 is bonded is the back side of the completed wooden diaphragm.
Step (b): A substantially V-shaped cut 11 having a vertex at the center and a small hole 12 in the vicinity of the vertex are provided on the laminated sheet 15. The cuts 11 are provided substantially along the grain direction (arrow f) of the bonded sheet 15.
Step (c): The lubricant 16 having the function of permeating into the bonding sheet 15 to impart moisture and holding moisture so that the laminated sheet 15 having the V-shaped cut is softened. Immerse in the liquid for 5-60 minutes and fully impregnate.
[0036]
This is in order to prevent the cracking in the subsequent primary press heat forming and to perform temporary forming with a high yield. According to the inventor's research, the lubricant 16 is not simply water or an alkaline aqueous solution, but an aqueous solution in which saccharides are dissolved. Step (d)... Of the V-shaped cuts 11 of the laminated sheet 15 impregnated with the lubricant 16 by the press device P1 having the mold configuration of the upper mold 31 and the lower mold 32 each provided with the heater 33. Primary press thermoforming (temporary molding) with the outer peripheral portion other than the molding portion of the laminated sheet 15 held by using a latching tool so that both edge portions 11a and 11b are overlapped with each other to form a substantially trumpet shape. ) Here, the setting conditions of the primary press thermoforming are as follows: the press pressure is approximately 1 to 10 kg, the mold temperature is approximately 80 to 150 ° C. for the upper die 31, approximately 100 to 200 ° C. for the lower die 32, and the press time is approximately 2 to 2. 60 seconds. The bonded sheet 15 is maintained in a substantially trumpet shape by this primary press thermoforming (temporary molding).
Step (e): Complete drying is carried out in a drying furnace (50-60 ° C.) for about 10-30 minutes.
Step (f) ... The temporarily bonded bonded sheet 15 after drying is immersed in the thermosetting resin 17 liquid for approximately 30 minutes to 180 minutes and sufficiently impregnated. As the thermosetting resin 17, a phenol resin is suitable.
Step (g): When the secondary press of the subsequent step is performed immediately after impregnation with the thermosetting resin 17, the thermosetting resin 17 is stuck to the mold, and cracks occur when the laminated sheet 15 is peeled off after pressing. As a result, tearing occurs and the yield decreases extremely. On the other hand, when it is completely dried, the moldability deteriorates and it becomes easy to crack. In order to prevent this, the thermosetting resin 17 is placed in a drying oven (50 ° C. to 60 ° C.) for approximately 1 to 10 minutes in a semi-dried state (so-called “finger-dried state” that is not sticky to the touch) ).
Step (h): The laminated sheet 15 in which the impregnated thermosetting resin 17 is semi-dried is press-heated again by the press device P2 having a known configuration similar to the step (d). Here, the setting conditions of the secondary press thermoforming are as follows: the press pressure is approximately 20 to 40 kg, the mold temperature is approximately 80 to 200 ° C. for the upper die 34, approximately 100 to 200 ° C. for the lower die 35, and the press time is approximately 10 to 10 ° C. 100 seconds. After the molding, the volatile components are evaporated, and the bonded sheet 15 having a molded shape stabilized in a substantially trumpet shape is obtained. Here, the thermosetting resin 17 also serves as an adhesive for the overlapping portion of the laminated sheet 15.
Step (i): The moisture-proofing agent 18 is applied to both the front and back surfaces of the bonded sheet 15 after the secondary press by brushing or jabbing, and then dried in a natural oven or in a drying oven. As the moisture-proof agent 18, for example, a mixture of polyisocyanate and polyester polyol is used. By applying this moisture-proofing agent, a secular change due to the humidity of the wooden diaphragm is suppressed, and a dynamic speaker having a long life is realized.
Step (j)... The press-molded laminated sheet 15 that has been moisture-proofed as described above is subjected to a central hole 25 for voice coil and an outer shape, and processed into a predetermined diaphragm shape so as to have a cone shape. A dynamic speaker wooden diaphragm 30 is completed.
[0037]
The wood grain of the wooden diaphragm 30 has various angles when viewed in the radial direction from the center, and the same sound propagation velocity does not exist in most directions, so that standing waves are hardly generated and almost resonance points are generated. As a result, split vibration is suppressed.
[0038]
In addition, the wooden diaphragm 30 has excellent acoustic characteristics based on being wooden as described above, and has been improved by impregnation with a special lubricant and thermosetting resin and a series of press heat forming processes. There are no cracks, the change with time due to humidity is small, and the grain has a beautiful finish with a long life. It should be noted that the manufacturing process is simple but has a very good yield and is excellent in mass productivity with reduced manufacturing costs.
[0039]
As shown in the cross-sectional view of FIG. 9A, the completed substantially trumpet-shaped wooden diaphragm 30 includes a damper 64, an edge 63, a voice coil 68, and the like, as in the conventional cone type dynamic speaker 60. The cone type dynamic speaker 38 is combined.
[0040]
Next, instead of the step of only the secondary press of the step (h) in FIG. 1 as a form of another manufacturing method of the substantially trumpet-shaped wooden diaphragm 30, it is surrounded by a broken line frame (h1) in FIG. Yield can be improved by performing steps (i) secondary press, (h2) mold release agent impregnation, (h3) drying, (h4) tertiary press (see schematic diagram in FIG. 4) before applying step (i) moisture-proofing agent. Since it improves and the finishing degree of a shaping | molding process also increases, it can be said that it is a preferable manufacturing method of a wooden diaphragm. Here, the setting conditions of the press apparatus P2 for the secondary press thermoforming in the step (h1) are a press pressure of about 20 to 40 kg, a mold temperature of the upper mold 34 of about 80 to 200 ° C., and a lower mold 35 of about 100. ~ 200 ° C, press time is about 2 to 30 seconds, and the setting conditions of the press apparatus P3 for the third press thermoforming in the step (h4) are a press pressure of about 20 to 40 kg and a mold temperature of the upper mold 36 About 80-200 degreeC, the lower mold | type 37 is about 100-200 degreeC, and press time is about 2 to 60 second. Further, as the release agent 46, silicon (silicon) is used.
[0041]
Next, a method for manufacturing a substantially dome-shaped wooden diaphragm used for the dome-type dynamic speaker according to the present invention will be described.
[0042]
As can be seen from the manufacturing process flow of FIG. 5, the manufacturing method of the substantially dome-shaped wooden diaphragm is composed of 9 steps (a) to (i) for the wooden sheet, (a) bonding, (b) Lubricant impregnation, (c) primary press, (d) drying, (e) thermosetting resin impregnation, (f) semi-drying, (g) secondary press, (h) moisture-proofing agent application, (i) center The outline dome-shaped wooden diaphragm 40 is completed in the order of outline drawing.
[0043]
In the manufacturing flow described above, there is no step of providing the substantially V-shaped cut 11 in the bonding sheet 15 in step (b) of the manufacturing process flow of FIG. 1 in the substantially trumpet-shaped wooden diaphragm 30 of the cone-type dynamic speaker described above. Other than that point, the other steps are equivalent. It can be said that the workability is simpler in that there is no V-shaped cutting step and it is not necessary to hold it in a substantially trumpet shape when performing the primary press in step (d).
[0044]
Of course, in the substantially dome-shaped wooden diaphragm 40, as another form of manufacturing method, instead of the step of only the secondary press in step (g) in FIG. Yield by performing steps (see schematic diagram in FIG. 8) of secondary press, (g2) mold release agent impregnation, (g3) drying, (g4) tertiary press before step (h) application of moisture-proofing agent And the finishing degree of the molding process is increased, so that it can be said to be a preferable method for producing a substantially dome-shaped wooden diaphragm. In addition, it is the same as the above that the release agent 46 in the step (g2) in FIG. 8 is silicon, and the upper die 48 and the lower die 47 of the tertiary press apparatus P3 in the step (g4) The press conditions are the same.
[0045]
The substantially dome-shaped wooden diaphragm 40 also has a beautiful finish with excellent acoustic characteristics and the like based on the fact that it is made of wood like the aforementioned substantially trumpet-shaped wooden diaphragm 30. The manufacturing process is simple but has a very good yield and is excellent in mass productivity with reduced manufacturing costs.
[0046]
The completed substantially dome-shaped wooden diaphragm 40 is combined with an edge 83, a voice coil 87, etc., as in the conventional dome-type dynamic speaker 80, as shown in the sectional view of FIG. 9B. Where the dome-shaped dynamic speaker 50 is formed, the shape and size of the substantially dome-shaped wooden diaphragm 40 is very similar to the shape and size of the cap 62 of the conventional cone-type dynamic speaker 60. 9 can be used as the wooden cap 39 of the cone type dynamic speaker 38 according to the present invention shown in FIG. According to this configuration, the front side of the cone-type dynamic speaker 38 is combined with the wooden diaphragm 30 having a beautiful grain and the wooden cap 39 at the center thereof, so that the speaker has a beautifully high-class feeling and unity.
[0047]
Next, the cone type dynamic speaker 38 is mounted in a wooden or plastic housing 95 as shown in FIG. 14 (a) front view and FIG. It becomes. Also, the

network circuit

92 or 93 of FIG. 16 is inserted into the dome type dynamic speaker 50 to make a tweeter dedicated to high frequency reproduction, and the corn type dynamic speaker 38 is combined as a woofer to reproduce other bands. By attaching to 95, it can also be set as a 2WAY speaker apparatus like FIG. Furthermore, a 3WAY speaker device and a coaxial 2WAY speaker system are also possible.
[0048]
As described above, when the

wooden diaphragms

30 and 40 are used for the woofer and tweeter diaphragms, all the diaphragms are made of wood, so that sound quality can be improved. If the frequency characteristic of the woofer is rampant near the crossover frequency, a network circuit 99 for high frequency cut as shown in FIG. 16C is inserted.
[0049]
As described above, the dynamic speaker of the present invention is not limited to a single speaker device as in the prior art, and is a speaker device having natural and excellent acoustic characteristics by combining various apertures, dome types, cone types, and the like. Can be configured.
[0050]
According to the inventor's research, in the dynamic speaker of each of the above-described embodiments, the resolution of reproduced sound is improved and the improvement of crisp sound is clearly improved compared to conventional paper pulp diaphragms and aluminum diaphragms. Was obtained when wood having a longitudinal propagation velocity of 4.5 to 6.0 km / second and a lateral propagation velocity of 2.0 to 4.5 km / second was selected.
[0051]
It is particularly noticeable that the sound quality is improved when the longitudinal propagation velocity is 4.5 to 6.0 km / second, the lateral propagation velocity is 2.0 to 2.5 km / second, and the internal loss factor is 0. This is the case where wood in the range of 0.02 to 0.03 was selected and used for the diaphragm, and the cover (solid material) was the best.
[0052]
Of course, the speaker diaphragm of the present invention can be applied not only to the hippo but also other timbers such as beech, oak, cherry, and china.
[0053]
Actually, the dome-type dynamic speaker 50 and the cone-type dynamic speaker 38 (caliber 8 cm in diameter) of the present invention using the network circuit 93 (capacitance C2 = 1.5 μF, inductor L1 = 0.18 mH) of FIG. In the 2WAY speaker device in combination with the degree, the excellent sound pressure, impedance, and distortion frequency characteristics shown in the actual measurement graph of FIG. 10 are obtained.
[0054]
【The invention's effect】
As described above, the dynamic speaker according to the present invention is a diaphragm which is a constituent element of either the dome type or the cone type, and is present in the manufacturing process of a conventional paper pulp diaphragm using a single piece of wood. This is a wooden diaphragm that has not been cooked with chemicals or beating wood fibers, so there is no deterioration in sound quality. can get.
[0055]
The wooden diaphragm prevents the occurrence of wrinkles and cracks during press thermoforming, and is a uniform press thermoformed product with a good finish, with little change over time such as deformation and cracking.
[0056]
It is a cone-type dynamic speaker that uses a light and durable substantially trumpet-shaped wooden diaphragm, so it is a dynamic speaker that supports all bands from woofers to full-range speakers.
[0057]
The dome-type dynamic speaker can be combined as a tweeter and the cone-type dynamic speaker can be combined as a woofer to form various types of speaker devices.
[0058]
In addition, existing manufacturing processes can be used, yield is good, mass productivity is excellent, and inexpensive supply can be realized.
[0059]
Further, the cone-type dynamic speaker has a natural grain appearance on the surface of the diaphragm or on the surface of the diaphragm and the cap, so that the appearance looks high-class and unified.
[0060]
With respect to the speaker device, not only the enclosure (cabinet) but also all the diaphragms of the speaker unit can be made of wooden diaphragms, so that it can be unified with a real wood grain design and a high-quality appearance can be provided.
[Brief description of the drawings]
FIG. 1 is a manufacturing process flow diagram of a wooden diaphragm used in a cone type dynamic speaker according to the present invention.
FIG. 2 is a schematic diagram showing each processing state (first half) of a manufacturing process flow of the wooden diaphragm of the cone type dynamic speaker.
FIG. 3 is a schematic diagram showing each processing state (second half) of the manufacturing process flow.
FIG. 4 is a schematic diagram showing a processing state of an additional flow within a broken line frame of the manufacturing process flow.
FIG. 5 is a manufacturing process flow of a wooden diaphragm used in a dome-type dynamic speaker according to the present invention.
FIG. 6 is a schematic diagram showing each processing state (first half) in the manufacturing process flow of the wooden diaphragm of the dome type dynamic speaker.
FIG. 7 is a schematic diagram showing each processing state (second half) of the manufacturing process flow.
FIG. 8 is a schematic diagram showing a processing state of an additional flow within a broken line frame of the manufacturing process flow.
9A is a cross-sectional view of a cone-type dynamic speaker according to the present invention, and FIG. 9B is a cross-sectional view of a dome-type dynamic speaker according to the present invention.
FIG. 10 is an actual measurement graph of frequency characteristics of sound pressure, impedance, and distortion of the 2WAY speaker device according to the present invention.
FIG. 11 is a graph showing the relationship between the internal loss coefficient and sound propagation speed (longitudinal direction) of various kinds of wood together with aluminum and paper as conventional materials.
FIG. 12 is a cross-sectional view showing the structure of a cone-type dynamic speaker.
FIG. 13 is a cross-sectional view showing the structure of a dome type dynamic speaker.
14A is a front view and FIG. 14B is a cross-sectional view of a speaker device in which a cone-type dynamic speaker is attached to a housing.
FIG. 15 is a front view of a 2WAY speaker device in which a cone type dynamic speaker and a dome type dynamic speaker are attached to a housing.
16A and 16B are tweeter network circuits, and FIG. 16C is a woofer high-frequency cut network circuit.
FIG. 17 is a diagram showing a manufacturing procedure of a conventional wooden diaphragm.
FIG. 18 is a diagram showing a manufacturing procedure of a conventional wooden diaphragm.
[Explanation of symbols]
10 Wooden sheet
11 V-shaped notch
11a, 11b both edges
12 Small hole
13 Nonwoven fabric or Japanese paper
15 Bonding sheet
16 Lubricant that provides moisture and retains moisture
17 Thermosetting resin
18 Moisturizer
25 Center hole
30 Wooden trumpet shaped like a rough trumpet
31, 34, 36, 43, 45, 48 Upper mold
33 Heater
32, 35, 37, 42, 44, 47 Lower mold
46 Release agent
38, 60 Cone type dynamic speaker
39 wooden cap
40 Substrate-shaped wooden diaphragm
50, 80 Dome type dynamic speaker
61 A substantially trumpet-shaped diaphragm
62 cap
63, 83 edge
64 damper
68, 87 Voice coil
81 Substantially domed diaphragm
95 body
90 Speaker device
92, 93, 99 Network circuit
100 2WAY speaker device
P1, P2, P3 press machine

Claims

In a cone-type dynamic speaker having a substantially trumpet-shaped diaphragm and a substantially dome-shaped cap that covers a small-diameter side opening of the diaphragm,
The substantially trumpet-shaped diaphragm is formed by attaching a thin non-woven fabric or Japanese paper on one side of a single wooden sheet to form a laminated sheet, and a substantially V-shaped notch that reaches the apex at the center of the laminated sheet. Providing a lubricant having an action of providing moisture to the laminated sheet provided with the cut and softening the laminated sheet, and holding the moisture in the laminated sheet, and the laminated sheet containing the lubricant is a primary press The edges of the substantially V-shaped cuts are overlapped by thermoforming and temporarily formed into a substantially trumpet shape, dried after the temporary forming, and include a thermosetting resin after drying, and the thermosetting resin is It is dried for about 1 to 10 minutes at a drying temperature of 50 ° C. to 60 ° C. until it becomes a semi-dry state, and is semi-dried, and is subjected to secondary press thermoforming in the semi-dry state of the thermosetting resin, Addition A wooden vibration formed by forming at least a moisture-proofing agent after molding, and performing a center hole punching and outline cutting for the voice coil on the laminated sheet coated with the moisture-proofing agent to form a predetermined size shape as a diaphragm. A cone-type dynamic speaker characterized by being a plate.

In a cone-type dynamic speaker having a substantially trumpet-shaped diaphragm and a substantially dome-shaped cap that covers a small-diameter side opening of the diaphragm,
The substantially dome-shaped cap sticks a thin non-woven fabric or Japanese paper on one side of a single wooden sheet to form a bonded sheet, and softens the bonded sheet by giving moisture to the bonded sheet. A laminated sheet containing a lubricant having a holding action is temporarily formed into a substantially dome shape by primary press thermoforming, dried after temporary molding, and a thermosetting resin is dried after drying. It is included and dried at a drying temperature of 50 ° C. to 60 ° C. for approximately 1 to 10 minutes until the thermosetting resin is in a semi-dry state, and is semi-dried. Press heat forming, and after the secondary press heat forming, at least a moisture proofing agent is applied, and the laminated sheet to which the moisture proofing agent is applied is extracted to obtain a predetermined dome-shaped cap. Cone type dynamic speaker, which is a cap obtained by molding the law shape.

The cone-type dynamic speaker according to claim 2, wherein the thin non-woven fabric or Japanese paper to be attached to one side of the wooden sheet which is a material of the substantially dome-shaped cap has a thickness of 0.02 to 0.30 mm, A cone type dynamic speaker, wherein the fiber direction of the non-woven fabric or Japanese paper and the wood grain of the wood sheet are bonded so as to be substantially perpendicular to each other.

3. The cone-type dynamic speaker according to claim 2, wherein the wooden sheet as the material of the substantially dome-shaped cap has a propagation speed of sound waves in the vertical direction along the grain of 4.5 to 6.0 km / sec. A cone type dynamic speaker characterized by being cut out from a solid material having an internal loss coefficient in the range of 0.02 to 0.03.

2. The cone-type dynamic speaker according to claim 1, wherein the wooden sheet as a material of the substantially trumpet-shaped diaphragm has a propagation speed of sound waves in the vertical direction along the grain of 4.5 to 6.0 km / sec. A cone-type dynamic speaker characterized by being cut out from a solid material having an internal loss coefficient in the range of 0.02 to 0.03.

A substantially trumpet-shaped diaphragm and a substantially dome-shaped cap that covers the opening on the small diameter side of the diaphragm are configured to transmit the vibration of a voice coil that vibrates based on the magnetic force of a magnetic circuit to the diaphragm and the cap. In the cone type dynamic speaker
The substantially trumpet-shaped diaphragm is formed by attaching a thin non-woven fabric or Japanese paper on one side of a single wooden sheet to form a laminated sheet, and a substantially V-shaped notch that reaches the apex at the center of the laminated sheet. Providing a lubricant having an action of providing moisture to the laminated sheet provided with the cut and softening the laminated sheet, and holding the moisture in the laminated sheet, and the laminated sheet containing the lubricant is a primary press The edges of the substantially V-shaped cuts are overlapped by thermoforming and temporarily formed into a substantially trumpet shape, dried after the temporary forming, and include a thermosetting resin after drying, and the thermosetting resin is It is dried for about 1 to 10 minutes at a drying temperature of 50 ° C. to 60 ° C. until it becomes a semi-dry state, and is semi-dried, and is subjected to secondary press thermoforming in the semi-dry state of the thermosetting resin, Addition A diaphragm obtained by forming at least a moisture-proofing agent after molding, and performing a hole punching and outline-cutting for a voice coil on a laminated sheet coated with the moisture-proofing agent to form a diaphragm with a predetermined dimension. And
The substantially dome-shaped cap sticks a thin non-woven fabric or Japanese paper on one side of a single wooden sheet to form a bonded sheet, and softens the bonded sheet by giving moisture to the bonded sheet. A laminated sheet containing a lubricant having a holding action is temporarily formed into a substantially dome shape by primary press thermoforming, dried after temporary molding, and a thermosetting resin is dried after drying. It is included and dried at a drying temperature of 50 ° C. to 60 ° C. for approximately 1 to 10 minutes until the thermosetting resin is in a semi-dry state, and is semi-dried. Press-molded, and after the secondary press-molding, at least a moisture-proofing agent is applied, and the bonded sheet coated with the moisture-proofing agent is extracted to obtain a predetermined dimension as a dome-shaped cap Cone type dynamic speaker, which is a cap obtained by molding the Jo.

A speaker device comprising the cone type dynamic speaker according to claim 6 attached to a housing.

In a dome-shaped dynamic speaker having a substantially dome-shaped diaphragm,
The substantially dome-shaped diaphragm is attached to a laminated sheet by sticking a thin non-woven fabric or Japanese paper on one side of a single wooden sheet, and the bonded sheet is softened by applying moisture to the bonded sheet. And a laminated sheet containing the lubricant is temporarily formed into a substantially dome shape by primary press thermoforming, dried after the temporary forming, and thermosetting resin after drying. And is dried for about 1 to 10 minutes at a drying temperature of 50 ° C. to 60 ° C. until the thermosetting resin is in a semi-dry state, and 2 in the semi-dry state of the thermosetting resin. Next press heat forming, after the secondary press heat forming, at least a moisture proofing agent is applied, and the bonded sheet coated with the moisture proofing agent is removed from the outer shape and formed into a predetermined dimension shape as a diaphragm. Dome dynamic speaker, which is a diaphragm that.