JPH0223800A - Piezo-electric diaphragm - Google Patents
Piezo-electric diaphragmInfo
- Publication number
- JPH0223800A JPH0223800A JP63174746A JP17474688A JPH0223800A JP H0223800 A JPH0223800 A JP H0223800A JP 63174746 A JP63174746 A JP 63174746A JP 17474688 A JP17474688 A JP 17474688A JP H0223800 A JPH0223800 A JP H0223800A
- Authority
- JP
- Japan
- Prior art keywords
- grooves
- piezoelectric material
- groove
- support plate
- piezo
- 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.)
- Pending
Links
- 239000000463 material Substances 0.000 claims description 55
- 230000002093 peripheral effect Effects 0.000 claims description 6
- 238000006073 displacement reaction Methods 0.000 abstract description 36
- 238000009826 distribution Methods 0.000 abstract description 15
- 239000002305 electric material Substances 0.000 abstract 5
- 239000000853 adhesive Substances 0.000 description 13
- 230000001070 adhesive effect Effects 0.000 description 13
- 230000000694 effects Effects 0.000 description 7
- 230000005684 electric field Effects 0.000 description 5
- 230000008602 contraction Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- FKSZLDCMQZJMFN-UHFFFAOYSA-N [Mg].[Pb] Chemical group [Mg].[Pb] FKSZLDCMQZJMFN-UHFFFAOYSA-N 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000003486 chemical etching Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 210000005069 ears Anatomy 0.000 description 1
- 239000002003 electrode paste Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
Landscapes
- Piezo-Electric Transducers For Audible Bands (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は圧電振動板、特に小型でかつ低周波において高
い音圧レベルを得る圧電型発音体などとして用いる圧電
振動板に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a piezoelectric diaphragm, and particularly to a piezoelectric diaphragm used as a piezoelectric sounding body that is small and produces a high sound pressure level at low frequencies.
圧電型発音体は支持板に両面電極を形成した圧電材を貼
付け、この電極間に交番電圧を加えることで、圧電材の
面方向l\の伸縮と支持板の無伸縮との関係から生じる
たわみ振動を利用したもので、支持板の片側に圧電材を
接着したユニモルフ構造と支持板の両面に圧電材を接着
したバイモルフ構造とがある−
この圧電型発音体は小型・薄型化が可能であり、特に取
扱いに注意を要する磁気を生じないことがら情報機器の
IDカート等と一緒に携帯する可能性のあるポケットベ
ルや移動通信機器になくてはならないものとなってきて
いる。In the piezoelectric sounding body, a piezoelectric material with electrodes formed on both sides is attached to a support plate, and by applying an alternating voltage between these electrodes, the deflection caused by the relationship between the expansion and contraction of the piezoelectric material in the plane direction l\ and the non-stretching of the support plate It uses vibration, and there are two types: a unimorph structure in which a piezoelectric material is bonded to one side of the support plate, and a bimorph structure in which piezoelectric material is bonded to both sides of the support plate.This piezoelectric sounding body can be made smaller and thinner. Because it does not generate magnetism that requires special handling, it has become indispensable for pagers and mobile communication devices that may be carried along with information equipment such as ID carts.
従来、この圧電型発音体は単に円板状の圧電材に電極を
形成して、これを金属製の薄い支持板に接着するだ【1
の構造とな−)でいて、これを小型・低周波化するため
に圧電材および支持板の厚みを50μm11以下I\と
薄くすると同時に、この支持板の外周部を自由状態に近
い支持とするため弾性接着剤て固定するものかぁ−)た
し、がし、支持板の厚みが薄くなると弾性接着剤の影
響が大きくなり、弾性接着剤の不均一な塗布によって性
能のバラツキか多くなる欠点かあった3
このような欠点を解決するために、’J′i即昭(−+
’。Conventionally, this piezoelectric sounding body was created by simply forming electrodes on a disc-shaped piezoelectric material and gluing this to a thin metal support plate [1].
In order to make this structure compact and low-frequency, the thickness of the piezoelectric material and support plate is reduced to 50 μm or less, and at the same time, the outer periphery of this support plate is supported in a nearly free state. However, as the thickness of the support plate becomes thinner, the effect of the elastic adhesive becomes greater, and the uneven application of the elastic adhesive increases the variation in performance. 3 In order to solve these shortcomings, 'J'i Sokuaki (-+
'.
188194r圧電型発音体」ては支持板の外周固定部
と圧電材の外周部との間に、両面交互で異なる位置に溝
を持たせることで、弾性接着剤の場合より共振周波数が
低くて、小型て且つ低周波化の圧電振動板を実現してい
る9さらに特願昭62−188195 r圧電振動板」
では、低周波1ヒのために圧電材の厚みを薄くしたとき
、圧電材の接着による変位量の低下により生じる音圧し
ベルの低下を防止する構造として、圧電材と支持板との
接着を部分接着としていて、これち前者の発明と後者の
発明とを一体化することによって小型で低周波特性の良
好な圧電型発音体が得られている3
〔発明が解決しようとする課題〕
上述したように支持板の周辺に両面交互で異なる位置に
溝を持たせ、接着面には部分接着とするための溝を持な
ぜることにより、小型て低周波特性の良好な圧電振動板
が得られた、しかし、ボゲ71−/\ル等の応用では、
小さなスペースに多くカ機能を含めたいため、電池や光
音14\のスペースを更に小さくするように求められ、
電池1個て駆動てき、1311111 j(Jθ)小さ
な形状ても実用上十分な音圧レベルを有し、なおか−)
2〜31< Hzの低い周波数の音を得る発音体か望ま
れることになる 上記の従来の円板状の発音体では第4
図の側面図に示すように、最大変位となる部分が中心部
の一点てあり、変位分布が1−’−ム状となるため、振
動板としての媒質排除量はあまり大きくない、この結果
、電池1個から1月られるIVI・ライフては音圧レベ
ルが小さいなめ昇圧コイルを用いて圧電材にく加わる電
圧を高めたり、電磁型の発音体を使用しなりればならな
いなとの問題点を有している1課題を解決するための手
段〕
本発明の圧電振動板は、支持板に圧電材を貼1寸()る
ことで得られる圧電振動板において、前記圧電材か貼f
・10られる支持板の外周部が支持固定されるとともに
、支持板の振動の節となる部分を除いて前記圧電材と支
持固定された外周部との間の支持板に、両面交互で異な
る位置にそれぞれ連続した少なくとも1本の溝を設けた
ことにより構成される。The 188194r piezoelectric sounding element has grooves at different positions alternately on both sides between the outer peripheral fixed part of the support plate and the outer peripheral part of the piezoelectric material, so that the resonance frequency is lower than that of elastic adhesive. A piezoelectric diaphragm that is small in size and has a low frequency.
Now, when the thickness of the piezoelectric material is made thinner for low frequency 1, we have partially bonded the piezoelectric material and the support plate as a structure to prevent the reduction in sound pressure and bell caused by the reduction in displacement due to the adhesion of the piezoelectric material. By integrating the former invention and the latter invention, a compact piezoelectric sounding body with good low frequency characteristics has been obtained.3 [Problem to be solved by the invention] As mentioned above. A small piezoelectric diaphragm with good low-frequency characteristics was obtained by providing grooves at different positions alternately on both sides around the support plate, and by providing grooves on the adhesive surface for partial adhesion. ,However, in the application of Boge71-/\ru et al.
Because we wanted to include many functions in a small space, we were asked to further reduce the space for the battery and light sound 14\.
It is powered by a single battery and has a practically sufficient sound pressure level despite its small size (1311111j(Jθ)).
A sounding body that produces low frequency sounds of 2 to 31 Hz is desired.In the conventional disc-shaped sounding body mentioned above,
As shown in the side view of the figure, the maximum displacement is at one point in the center, and the displacement distribution is 1-'-mm-shaped, so the amount of medium removed by the diaphragm is not very large.As a result, The problem with IVI/life, which lasts a month from one battery, is that it is necessary to use a step-up coil with a low sound pressure level to increase the voltage applied to the piezoelectric material, or to use an electromagnetic sounding body. A piezoelectric diaphragm of the present invention is a piezoelectric diaphragm obtained by pasting a piezoelectric material on a support plate for one inch (1 inch).
・The outer periphery of the support plate to be supported and fixed is supported and fixed, and the support plate between the piezoelectric material and the supported and fixed outer periphery is alternately placed at different positions on both sides, except for the vibration nodes of the support plate. At least one continuous groove is provided in each of the grooves.
支持板が方形の支持板であり、この支持板の中心部に方
形状の圧電材を貼りf=Jす、この圧電材の三方の外周
部に両面交互で異なる位置に溝を持たせると、この溝が
ひた(襞)的にjY用をし、この溝の部分ては上下の動
きを容易にする。この結果、支持板を三方の溝の外側と
溝の無い他の一辺とて固定すれば、圧電材に電界を加え
ることで生じるたわみ振動は、三方の溝の中間の部分て
最大変位となる。またこの最大変位となる部分は三方の
溝の中間の辺の長さとなり、円板を用いた周辺固定の場
合に較べて最大変位面積はずっと広くなる。The support plate is a rectangular support plate, and a rectangular piezoelectric material is attached to the center of the support plate f = J.If grooves are provided at different positions alternately on both sides of the outer periphery of the piezoelectric material on three sides, then This groove serves as a fold for JY purposes, and this groove facilitates vertical movement. As a result, if the support plate is fixed on the outside of the grooves on three sides and the other side without grooves, the deflection vibration generated by applying an electric field to the piezoelectric material will have a maximum displacement at the middle part of the grooves on three sides. Furthermore, the portion where the maximum displacement occurs is the length of the middle side of the three grooves, and the maximum displacement area is much wider than in the case of peripheral fixation using a disk.
このなめ、振動板の媒質排除量は大きく5発音体として
用いた場合には生じる音圧レベルが媒質の排除量に比例
する関係から、円板を用いた周辺固定の発音体に比較し
て高くなる。単に方形の圧電材を支持板に賭けけてこの
周辺を固定したのでは、中心部かたわみ変形を起こすた
けて変形に等方性か無くなることから、高調波か多くな
るなど円板の場合より光音11J−性はM1ヒするか、
本発明ては方形の圧電材の三方の外周部に両面交互で異
なる位置に渦かあるため、圧電材の三方では自由状態に
近くなる。この結果、三方の講の中間部分の辺て圧電材
の曲線による変位か最大となる2このような最大変位と
なる部分が面状となる振動板は、発音体として有効なた
C)ではなく、外部からの力の入力により圧カセンザや
振動検出センサ、その他マイクロホン的な用途かあり、
また振動面の変位を(公達媒体を用いて変位を拡大する
なとして用いるアクチエータとし゛この用途もある。Because of this, the amount of medium removed by the diaphragm is large, and when used as a five-sounding element, the sound pressure level generated is proportional to the amount of medium removed, so it is higher than that of a circular sounding element that is fixed around the periphery. Become. If a rectangular piezoelectric material is simply placed on a support plate and its periphery is fixed, the central part will bend and deform, and the deformation will be isotropic or not, resulting in more harmonics than in the case of a disk. Koon 11J-Is it as good as M1?
In the present invention, since the vortices are alternately located on both sides and at different positions on the outer periphery of the three sides of the rectangular piezoelectric material, the piezoelectric material is almost in a free state on the three sides. As a result, the displacement due to the curve of the piezoelectric material is maximum at the middle part of the three-way diaphragm.2 A diaphragm in which the part where the maximum displacement occurs is planar is not effective as a sounding body (C). , pressure sensors, vibration detection sensors, and other microphone-like applications can be achieved by inputting external force.
It is also used as an actuator that uses the displacement of the vibrating surface (without expanding the displacement using a public medium).
「実施例:
以下、本発明の実施例に−)いて図面を参照して説明す
る。Embodiments: Hereinafter, embodiments of the present invention will be described with reference to the drawings.
第1図は本発明の一実施例の一部をbノ欠いた斜視図で
、圧電型光音(4i′として用いた場合を示している。FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, showing the case where it is used as a piezoelectric type optical sound (4i').
本実施例では圧電材11は方形となっていて、この圧電
材11を貼付ける支持板12は圧電材11の外周部であ
る三辺に沿って、両面交互て異なる位置に溝13を複数
本持っており、この方の講13の外側の溝の無い他の一
辺とを周辺固定体14て支持固定したものである。この
とき、圧電材11と支持板12との接着部は切欠いた部
分に示すように、支持板12の圧電材接着面には部分接
着の溝21を持っており、圧電材1]と支持板12が部
分接着となっている。さらに圧電材に形成する電極は、
接着面側は全面ベタ電極としているか、表側の面ては裏
面の電極をスルーポールで引上け、リード線を接続する
ための端子22と表側の電極の2つが形成されている。In this embodiment, the piezoelectric material 11 is rectangular, and the support plate 12 to which the piezoelectric material 11 is attached has a plurality of grooves 13 at different positions alternately on both sides along the three sides, which are the outer periphery of the piezoelectric material 11. This side is supported and fixed by a peripheral fixing body 14 on the other side without a groove on the outside of this side 13. At this time, the adhesive part between the piezoelectric material 11 and the support plate 12 has a groove 21 for partial adhesion on the piezoelectric material adhesive surface of the support plate 12, as shown in the notched part, and the piezoelectric material 1] and the support plate 12 is partially bonded. Furthermore, the electrodes formed on the piezoelectric material are
On the adhesive side, the entire surface is a solid electrode, or on the front side, the electrode on the back side is pulled up with a through pole, and two terminals 22 for connecting lead wires and the electrode on the front side are formed.
ここて示した部分接着の満21は、低周波化にとらなっ
て圧電材が薄くなることによって生L7る接着による変
位の低下を防止する効果を持なぜている。The partial adhesion 21 shown here has the effect of preventing a decrease in displacement due to adhesion, which occurs when the piezoelectric material becomes thinner as the frequency becomes lower.
このように構成した圧電型発音体は、従来の圧電発音体
と同様に圧電材の両面に形成した電極間に交流電界を加
えることで圧電材が面方向に伸縮するが、本発明では圧
電材の接着が部分接着となっているため、接着されてい
る部分より接着されていない部分の方が、この伸縮の変
位がすっと大きい。このなめ、圧電材の伸縮は部分接着
の溝に対し直角方向に効果を示し、これかたわみ変形を
生しさせる7さらに、このたわみ変形は圧電材の外周部
の三方に形成した両面交互で異なる位置に設けた溝を有
することにより、この三方の溝の部分て自由状態に近く
、講を形成していない残る一方が固定状態を作り出す。In the piezoelectric sounding body constructed in this way, the piezoelectric material expands and contracts in the plane direction by applying an alternating electric field between the electrodes formed on both sides of the piezoelectric material, similar to the conventional piezoelectric sounding body. Since the adhesive is a partial adhesive, the displacement of this expansion and contraction is much larger in the non-adhered part than in the adhesive part. This licking and expansion/contraction of the piezoelectric material have an effect in the direction perpendicular to the groove of the partial adhesion, causing a deflection deformation. By having grooves provided at certain positions, the grooves on these three sides are in a nearly free state, and the remaining one, which does not form a groove, is in a fixed state.
この結果、交流電界による振動の変位分布は三方の講σ
〕中間の辺で最大となる5
第2図は第1図の実施例の振動の変位分布図で、変位分
布か矢印と破線とて示されている。変位は溝の無い一辺
の側をゼロとして三方の湯の中間の辺側か最大となり、
最大となる部分は三方の溝の中間の辺の長さとなるため
、前記第4図に示したような従来の円板状の圧電型発音
体のような中心部だけの点となる最大変位の分布ではな
くなり、媒質排除量が大きく発生する音圧のレベルが高
くなる。As a result, the displacement distribution of vibration due to the AC electric field is
] Maximum at the middle side 5 FIG. 2 is a diagram of the vibration displacement distribution of the embodiment shown in FIG. 1, and the displacement distribution is indicated by arrows and broken lines. The displacement is zero on one side without grooves, and is maximum on the side in the middle of the three sides.
The maximum displacement is the length of the middle side of the three grooves, so the maximum displacement is only at the center of the conventional disc-shaped piezoelectric sounding body as shown in Fig. 4. The distribution will no longer be the same, and the level of sound pressure generated will increase as the amount of medium exclusion increases.
外形寸法の仕様が13IIIIll×1311mの従来
例と本発明の実施例との圧電型発音体の場合について性
能を示す。まず、従来の周辺部にリング状の溝を設けた
例では、外形13龍の条件から外周部に支持固定するた
めの耳を1市幅とすると、支持直径が11mmとなり、
振動の変位分布が外周固定の条件から中心部で最大とな
るドーム状となるため、最大変位の得られるのは中心部
の一点だけである。Performance will be shown in the case of a piezoelectric sounding body of a conventional example and an embodiment of the present invention whose external dimensions are 13IIIll x 1311 m. First, in the conventional example where a ring-shaped groove is provided on the periphery, if the ears for supporting and fixing on the outer periphery are one city wide, the support diameter is 11 mm.
Due to the condition that the outer periphery is fixed, the vibration displacement distribution becomes dome-shaped with the maximum at the center, so the maximum displacement can only be obtained at one point at the center.
この結果、測定距離30 cmでI■ドライブのとき2
kH7〜3kH7で70〜75dBであり、実用レベル
とするにはドライブ電圧を高くするなどしてやらなけれ
ばならない。As a result, when the measurement distance is 30 cm and I drive
It is 70 to 75 dB at kHz 7 to 3kHz 7, and to achieve a practical level, the drive voltage must be increased.
これに対し、本発明の実施例では、圧電材の外周部の三
方の溝により、最大変位となる点は講の無い固定端から
の距離かほぼ2倍となるため、共振周波数は低くなり、
このとき最大変位の絶対値も高くなおかつ、この変位分
布は面状となる。この結果、同じ測定距離30cmで1
■ドライブのとき2 k Hz 〜3 k Hzの音が
80〜85dBと高い音圧レベルとなった。このため従
来の昇圧コイルの使用や電池の電圧を高くする必要がな
く、電池1個(1,5V)でも実用上十分な音圧レベル
が得られる。In contrast, in the embodiment of the present invention, due to the three-sided grooves on the outer periphery of the piezoelectric material, the point at which the maximum displacement occurs is approximately twice the distance from the free fixed end, so the resonant frequency is low.
At this time, the absolute value of the maximum displacement is also high, and the displacement distribution becomes planar. As a result, 1 at the same measurement distance of 30 cm.
■When driving, the sound pressure level of 2 kHz to 3 kHz was as high as 80 to 85 dB. Therefore, there is no need to use a conventional booster coil or to increase the battery voltage, and a practically sufficient sound pressure level can be obtained with just one battery (1.5V).
ここで用いた圧電材は、マグネシウム ニオブ酸鉛Pb
(Mgl/3・N l)2/3)03を主成分とする電
歪材料の粉末を有機バインダとともに溶媒中に分散して
スラリ状とする5これをドクタブレードを用いたスリッ
プキャスティング法によって、厚さ100μrn前後の
均一な厚みの圧電材グリーンシートとする。次に、この
圧電材クリーンシートを規定の大きさに打抜き、接着面
側の電極を表側に引上げるためのスルーホール接続用の
穴をパンチおよびタイによって形成する。次に、この穴
明けを行った圧電材クリーンシートの両面にスクリーン
印刷機を用いて電極ペーストを印刷する。さらに、この
印刷された圧電材グリーンシートをプレス金型にセラ1
〜し、100℃前後の温度で加熱し、250 k g、
/cm2程度の圧力を加えて密度を高めた圧電材グリー
ンシー)・とする。次に、プレスした圧電材クリーンシ
ートを所定の寸法に切断した後、まず空洞パターンやセ
ラミッククリーンシート中に存在する有機物を脱パイン
ダニ程において酸化雰囲気中でゆっくりと加熱し、分解
・消失させる。通常これらの有機物は500℃〜600
℃までには完全に分解・酸化するが、急激に温度を分解
温度まで上げると圧電材が破損するので25℃/時間あ
るいは、これよりもゆっくりとした温度上昇スピードで
温度を上げ、500℃〜600℃に充分長い時間保持す
ることで有機物を完全に消失させる。この後、900℃
〜1200 ’(’の温度で焼成することで、前記説明
で述べた圧電型発音体を構成する圧電材平板が得られる
。The piezoelectric material used here is magnesium lead niobate Pb
(Mgl/3・Nl)2/3)03 is dispersed in a solvent together with an organic binder to form a slurry. A piezoelectric green sheet with a uniform thickness of about 100 μrn is used. Next, this piezoelectric material clean sheet is punched out to a specified size, and holes for through-hole connections for pulling up the electrodes on the adhesive side to the front side are formed using punches and ties. Next, electrode paste is printed on both sides of the piezoelectric material clean sheet with holes using a screen printer. Furthermore, this printed piezoelectric material green sheet is placed in a press mold with Cera 1.
~, heated at a temperature of around 100℃, 250 kg,
Greensea is a piezoelectric material whose density is increased by applying pressure of about /cm2. Next, after cutting the pressed piezoelectric material clean sheet into predetermined dimensions, first, the organic matter present in the cavity pattern and the ceramic clean sheet is slowly heated in an oxidizing atmosphere in the depine mite removal process to decompose and eliminate it. Usually these organic substances are heated to 500℃~600℃
℃, it will completely decompose and oxidize, but if the temperature is suddenly raised to the decomposition temperature, the piezoelectric material will be damaged, so raise the temperature at 25℃/hour or at a slower rate of temperature rise to 500℃~ By keeping the temperature at 600°C for a sufficiently long time, organic substances are completely eliminated. After this, 900℃
By firing at a temperature of ~1200'('), a piezoelectric material flat plate constituting the piezoelectric sounding body described in the above description can be obtained.
一方、支持板は厚さ50μm程度のステンレス板を用い
、支持板に形成する溝は通常の化学エツチングによって
得られ、深さを厚さの215〜315以上とした。On the other hand, the support plate was made of a stainless steel plate with a thickness of about 50 μm, and the grooves formed in the support plate were obtained by ordinary chemical etching, and the depth was set to be 215 to 315 times greater than the thickness.
第3図(a>、(b)、(c)および(d)はそれぞれ
本発明の別の実施例を示す固定部分と溝形成部分との配
置関係を示すモデル図で、固定部分とするために溝を形
成しない部分を破線で囲って示してあり、両面交互に形
成する溝の位置を太い実線で示しである。いずれの場合
にも、貼付ける圧電材の位置は、両面交互に形成した溝
の内側であり、この溝か2個所に形成されている(C)
および(d)の場合は固定部分を中間にして2つの溝に
囲まれた内側になる。FIGS. 3(a), (b), (c), and (d) are model diagrams showing the arrangement relationship between the fixed part and the groove forming part, respectively, showing another embodiment of the present invention. The parts where grooves are not formed are shown surrounded by broken lines, and the positions of grooves formed alternately on both sides are shown by thick solid lines.In either case, the position of the piezoelectric material to be pasted is It is inside the groove and is formed in two places in this groove (C)
In the case of (d), the fixed part is in the middle surrounded by two grooves.
このようにして構成した振動板でも、最大変位の得られ
る部分は連続した溝の中間部分となり、いずれの場合に
も円板のときのような最大変位となる部分が一点となる
ドーム状の変位分布とは異なり、変位分布は面状となる
。この結果、振動板としての媒質排除量は大きくなり、
発音体としての音圧レベルは高くなる。さらに、これら
実施例の中の(c)および(d)の場合は振動部分が2
つとなるため、同−形状内では共振周波数は高くなるが
、比較的周波数の高くて良い発音体としての使用では音
圧レベルを高くするたりてなく、固定部分の位置を中心
からどちらかにすらすことによって、2つの振動板の共
振周波数を異なる位置に設定することができる、この結
果、発音体としての特性は2つの振動板の特性が重ね合
わされることになるため広帯域な特性が得られる。Even with a diaphragm configured in this way, the part where the maximum displacement can be obtained is the middle part of the continuous grooves, and in either case, the part with the maximum displacement is a dome-shaped displacement where the part with the maximum displacement is at one point like in the case of a disk. Unlike the distribution, the displacement distribution is planar. As a result, the amount of medium removed by the diaphragm increases,
The sound pressure level as a sounding body increases. Furthermore, in cases (c) and (d) of these examples, the vibrating portion is 2
Therefore, the resonant frequency will be high within the same shape, but when used as a good sounding body with a relatively high frequency, the sound pressure level will not be high, and the position of the fixed part will not be shifted from the center to either side. By doing so, the resonant frequencies of the two diaphragms can be set at different positions.As a result, the characteristics of the sounding body are overlapping the characteristics of the two diaphragms, resulting in broadband characteristics. .
このように圧電材の一辺が支持固定状態となるように、
この部分では溝を形成せず、残る他の辺に連続の両面交
互の溝を形成すれば、振動板の形状に限定されることな
く、この効果は第1図の実施例で示したものとまったく
同じとなる。In this way, so that one side of the piezoelectric material is supported and fixed,
If no grooves are formed in this part and continuous grooves are formed alternately on both sides on the remaining sides, this effect is not limited to the shape of the diaphragm and can be achieved as shown in the embodiment shown in Fig. 1. It will be exactly the same.
なお、以上の実施例で示してきた溝を形成する支持板と
しては、ステンレス板、黄銅板やその他の金属板だけで
なく溝形成を行える材料ならどのようなものでも可能で
、この溝の形成方法もエツチングに限定されることはな
い。例えば、このエツチングによる溝と同じ形状となる
金型をエツチング等で作っておいて、これを用いて支持
板をプレス成形しても良い。Note that the support plate for forming the grooves shown in the above embodiments can be made of not only stainless steel plates, brass plates, and other metal plates, but also any material that can form grooves. The method is not limited to etching either. For example, a mold having the same shape as the etched groove may be made by etching, and the support plate may be press-molded using this mold.
さらに、圧電材を片面にだけ接着したものについて示し
たが、圧電材を支持板の両面に形成しても良い。また、
圧電材も前記実施例で述べた材料に限定されることはな
い。Further, although the piezoelectric material is bonded to only one side of the support plate, the piezoelectric material may be formed on both sides of the support plate. Also,
The piezoelectric material is also not limited to the materials described in the above embodiments.
また、前記実施例では、接着面に溝をもうけて部分接着
としたか、溝が無くても接着時の接着剤の形成を部分接
着のパターンとすることでも拘わす、音質的に高い性能
が要求されない高調波の発生等の許される用途では、部
分接着を用いず全面接着としても得られる振動変位分布
は面状となり音圧レベルは高くなる。In addition, in the above-mentioned embodiments, grooves are formed on the adhesive surface for partial adhesion, or even if there are no grooves, the adhesive is formed in a partial adhesion pattern during adhesion, resulting in high performance in terms of sound quality. In applications where the generation of undesired harmonics is permissible, the vibration displacement distribution obtained even if the entire surface is bonded without using partial bonding will be planar and the sound pressure level will be high.
以上の説明では、本発明の圧電振動板を圧電型発音体と
して示してきたが、圧電材に電界を加えるのではなく、
外力によって生じる電荷を利用するセンサとし、ても利
用ができ、圧カセンザやマイクロホンとして用いる場合
にも外部入力に対する電荷の発生効率の高いものが得ら
れる。In the above explanation, the piezoelectric diaphragm of the present invention has been shown as a piezoelectric sounding body, but instead of applying an electric field to the piezoelectric material,
It can also be used as a sensor that utilizes charges generated by external force, and when used as a pressure sensor or a microphone, a sensor with high charge generation efficiency in response to external input can be obtained.
以上詳細に説明したとおり本発明の圧電振動板は、圧電
材を貼り付ける支持板に圧電材の一部を支持固定するた
めの溝の無い辺を設け、残る他の辺の周辺部に両面交互
で異なる位置に溝をもうけることによって、この辺に設
けた溝の部分で自由状態を作り出し、溝を形成していな
い残る一方が固定状態を作り出すことができる。この結
果、圧電材に電界を加えることによって生じるたわみ振
動の変位分布は、溝を形成していない辺の部分をゼロと
して溝を形成した中間の辺側か最大となり、この最大変
位となる部分は面状となるなめ、従来の円形の振動板の
ようなドーム状となる変位分布ではなくなり、発音体と
して用いる場合には高い音圧レベルが得られる。またセ
ンサとし゛この用途では、外部入力に対して発生する電
荷は大きくなり、検出感度が向上する効果がある。As explained in detail above, in the piezoelectric diaphragm of the present invention, a side without grooves for supporting and fixing a part of the piezoelectric material is provided on the support plate to which the piezoelectric material is attached, and both sides are alternately arranged around the other remaining sides. By creating grooves at different positions on this side, the grooves on this side can create a free state, and the remaining part without grooves can create a fixed state. As a result, the displacement distribution of the flexural vibration caused by applying an electric field to the piezoelectric material is zero at the side where no grooves are formed, and reaches a maximum at the middle side where the grooves are formed, and the area where the maximum displacement is The diaphragm has a planar shape and does not have a dome-like displacement distribution like the conventional circular diaphragm, and when used as a sounding body, a high sound pressure level can be obtained. Furthermore, in this application as a sensor, the electric charge generated in response to an external input becomes large, which has the effect of improving detection sensitivity.
第1図は本発明の一実施例の一部を切欠いた斜視図、第
2図は第1図の振動板の変位分布を示す斜視図、第3図
(a>、 (1:+)、 <<2)および(d)は
別の実施例のモデル図、第4図は従来の円形振動板の振
動の変位分布を示す側面図である。
11・・・圧電材、12・・・支持板、13・・両面交
互の溝、14・・・周辺固定体、21・・部分接着のた
めの講、22・・裏面電極の端子。Fig. 1 is a partially cutaway perspective view of an embodiment of the present invention, Fig. 2 is a perspective view showing the displacement distribution of the diaphragm in Fig. 1, Fig. 3 (a>, (1:+), <<2) and (d) are model diagrams of another embodiment, and FIG. 4 is a side view showing the vibration displacement distribution of a conventional circular diaphragm. DESCRIPTION OF SYMBOLS 11... Piezoelectric material, 12... Support plate, 13... Grooves alternately on both sides, 14... Peripheral fixing body, 21... Lecture for partial adhesion, 22... Terminal for back electrode.
Claims (1)
において、前記圧電材が貼付けられる支持板の外周部が
支持固定されるとともに、支持板の振動の節となる部分
を除いて前記圧電材と支持固定された外周部との間の支
持板に、両面交互で異なる位置にそれぞれ連続した少な
くとも1本の溝を設けたことを特徴とする圧電振動板。In a piezoelectric diaphragm obtained by pasting a piezoelectric material on a support plate, the outer periphery of the support plate to which the piezoelectric material is pasted is supported and fixed, and the piezoelectric material is removed except for the vibration nodes of the support plate. 1. A piezoelectric diaphragm characterized in that a support plate between the support plate and the supported and fixed outer peripheral part is provided with at least one consecutive groove at different positions alternately on both sides.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63174746A JPH0223800A (en) | 1988-07-12 | 1988-07-12 | Piezo-electric diaphragm |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63174746A JPH0223800A (en) | 1988-07-12 | 1988-07-12 | Piezo-electric diaphragm |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0223800A true JPH0223800A (en) | 1990-01-25 |
Family
ID=15983958
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP63174746A Pending JPH0223800A (en) | 1988-07-12 | 1988-07-12 | Piezo-electric diaphragm |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0223800A (en) |
-
1988
- 1988-07-12 JP JP63174746A patent/JPH0223800A/en active Pending
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