JP4032967B2

JP4032967B2 - Glass break sensor

Info

Publication number: JP4032967B2
Application number: JP2002377837A
Authority: JP
Inventors: 究柴田; 秀夫森
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 2002-12-26
Filing date: 2002-12-26
Publication date: 2008-01-16
Anticipated expiration: 2022-12-26
Also published as: JP2004206616A

Description

【０００１】
【発明の属する技術分野】
本発明は、室内外を仕切るガラス板に取り付けられガラス板の破壊を検知するガラス破壊センサに関するものである。
【０００２】
【従来の技術】
従来から、窓ガラスやガラス扉など室内外を仕切るガラス板に取り付けられ、室内に侵入しようとする者（以下、侵入者）がガラス板を破壊したときにこれを検知して音や光によって報知する防犯用のガラス破壊センサが提供されている。この種のガラス破壊センサは、振動検知手段としてガラス板の振動を電圧信号に変換する圧電素子を用いて、警報閾値よりも圧電素子の出力信号の振幅が大きければ警報を出力するもので、一般に図２、図３に示すようにガラス破壊センサの外郭を形成してガラス板に取り付けられるハウジング１が成形品である場合、円板状の圧電素子２をハウジング１に接着剤３で貼り付けていた。
【０００３】
また、圧電素子２をハウジング１に接着剤３を使って固定する場合図１８に示すように、接着剤３の塗布量と硬化時に圧電素子２に加える荷重とを管理することで接着剤層の厚みを管理していた。
【０００４】
あるいは、ハウジングの接着面に凹部を設けて、凹部の深さに応じた接着剤層を形成したり、ハウジングの接着面に凸部を設けて、凸部の高さに応じた接着剤層を形成したりして、接着剤層の厚みを管理していた。（例えば、特許文献１参照。）
さらに圧電素子２は図２に示すように、ハウジング１との接着面（裏面）と、接着面に対向する面（表面）とに各々電極２１を形成しており、非金属のハウジング１に接着する場合は、ハウジング１に接着する裏面の電極２１からの信号を取り出すために圧電素子２の裏側の電極２１から側面へ延長され圧電素子２の表面側に引き出す折り返し電極２２の電極パターンを形成している。表面の電極２１及び折り返し電極２２は各々、電線５を介して回路部と電気的に接続されている。
【０００５】
【特許文献１】
特開平６−６１２７６号公報（２頁左欄第２４行〜第２７行、２頁右欄第１９行〜第４８行、図１〜図４）
【０００６】
【発明が解決しようとする課題】
しかし、上述した従来のガラス破壊センサでは接着剤３として硬度の高いエポキシ系接着剤等を用いており、圧電素子２を成形品のハウジング１に貼り付けると、図１９に示すように、周囲環境の温度変化によりハウジング１が図中破線のように変形し、その歪み（例えば接着面に対して垂直なＹ１，Ｙ２方向）が接着剤３を介して圧電素子２に伝わり、ハウジング１と接着剤３及び圧電素子２との線膨張係数の違いにより圧電素子２がハウジング１の変形に追従できずに破損するという問題があった。
【０００７】
本発明は、上記事由に鑑みてなされたものであり、その目的は、周囲環境の温度変化による圧電素子の破損を防止したガラス破壊センサを提供することにある。
【０００８】
【課題を解決するための手段】
請求項１の発明は、建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記接着剤は、硬化後の硬度がショア−硬度Ａで４０以下であり、前記ハウジングは、前記圧電素子が接着される箇所に、前記圧電素子を載置して予め定めた接着剤層の厚みに相当する同一高さの複数の凸部を備え、前記複数の凸部は、載置される前記圧電素子が前記ハウジングに対する平行度を維持できる箇所に各々配置されることを特徴とする。
【０００９】
請求項２の発明は、建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記接着剤は、硬化後の硬度がショア−硬度Ａで４０以下であり、前記ハウジングは、前記圧電素子が接着される箇所に、前記圧電素子の接着面の周縁部を載置する台部と、前記台部の内側に形成されて予め定めた接着剤層の厚みに相当する一定深さの凹部とを備え、前記台部は、載置された前記圧電素子が前記ハウジングに対する平行度を維持できる形状に形成されることを特徴とする。
【００１０】
請求項３の発明は、建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記ハウジングは、前記圧電素子の接着面を囲むように前記圧電素子の周囲に立設した壁を有するとともに、前記圧電素子が接着される箇所に、前記圧電素子を載置して予め定めた接着剤層の厚みに相当する同一高さの複数の凸部を備え、前記複数の凸部は、載置される前記圧電素子が前記ハウジングに対する平行度を維持できる箇所に各々配置されることを特徴とする。
【００１１】
請求項４の発明は、建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記ハウジングは、前記圧電素子の接着面を囲むように前記圧電素子の周囲に立設した壁を有するとともに、前記圧電素子が接着される箇所に、前記圧電素子の接着面の周縁部を載置する台部と、前記台部の内側に形成されて予め定めた接着剤層の厚みに相当する一定深さの凹部とを備え、前記台部は、載置された前記圧電素子が前記ハウジングに対する平行度を維持できる形状に形成されることを特徴とする。
【００１２】
請求項５の発明は、請求項１乃至４いずれかにおいて、前記圧電素子は、接着面と該接着面に対向する面とに各々電極を設け、外面の少なくとも一部を前記電極の対向方向に段差を設けた階段形状としたことを特徴とする。
【００１３】
請求項６の発明は、請求項１乃至４いずれかにおいて、前記圧電素子は、少なくとも一方面に電極を各々形成した第１，第２の素子部の各他方面間に第３の素子部を挟んだ３段構成となり、第１，第２の素子部に各々設けた電極間の絶縁距離は、少なくとも第１，第２の素子部間の第３の素子部の厚みを含むことを特徴とする。
【００１４】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて説明する。
【００１５】
（参考例１）
本参考例のガラス破壊センサは図１（ａ）に示すように、ガラス板Ｇに両面粘着シートによって取り付けられる成形品のハウジング１内に固定されてガラス板Ｇの振動を電圧信号に変換する円板状の圧電素子２を備えて、警報閾値よりも圧電素子２の出力信号の振幅が大きければ警報を出力するもので、その回路部の構成は図１（ｂ）に示すように、圧電素子２に並列接続された抵抗Ｒ１と、圧電素子２の出力信号のうちガラス板Ｇの破壊に関わる周波数が通過しノイズが除去される程度にカットオフ周波数が設定されたハイパスフィルタ回路Ｓ１と、ハイパスフィルタ回路Ｓ１の出力と警報閾値電圧Ｖｔｈとを比較する比較判断部Ｓ２と、比較判断部Ｓ２の判断結果が、警報閾値電圧Ｖｔｈよりもハイパスフィルタ回路Ｓ１の出力が大きければ警報を発する警報出力部Ｓ３とから構成される。
【００１６】
圧電素子２は図２、図３に示すようにハウジング１に接着剤３で貼り付けられ、従来例と同様に表面の電極２１及び折り返し電極２２は各々、電線５を介して図１（ｂ）に示す回路部と電気的に接続されている。
【００１７】
本参考例では、接着剤３にショア−硬度Ａ＝４０以下のもの、例えばシリコン系接着剤を用いている点が従来例と異なる。
【００１８】
次に、この圧電素子２を硬度の各々異なる接着剤３で成形品のハウジング１に貼りつけたサンプルについて、周囲環境の温度変化に対して圧電素子２の破損の有無を確認するために、熱衝撃試験により破損状況の有無の確認を行った。サンプルとして、接着剤３ａ：ショア−硬度Ｄ＝８９（ショア−硬度Ａ＝９０以上）、接着剤３ｂ：ショア−硬度Ｄ＝７５（ショア−硬度Ａ＝９０以上）、接着剤３ｃ：ショア−硬度Ｄ＝４０（ショア−硬度Ａ＝９０）、接着剤３ｄ：ショア−硬度Ａ＝４０の４種類を用意した。尚、試験条件は使用温度範囲に対し低温側高温側ともに２５℃拡張した−４０℃〜８０℃で、５０サイクルという厳しい条件とした。
【００１９】
熱衝撃試験の結果は図４に示すように、接着剤３ａ，３ｂを用いたサンプルは、圧電素子２が厚み方向で２つに分断され、接着剤３ｃを用いたサンプルは、サンプルの一部が破損、あるいは電極部分の剥離による感度劣化を起こしていた。しかし、接着剤３ｄを用いたサンプルは破損、感度劣化共なかった。したがって本参考例では接着剤３にショア−硬度Ａ＝４０以下のものを用いることで、ハウジング１と圧電素子２との間で接着剤３が各々の線膨張係数の違いによる伸縮を吸収する形となって、圧電素子２の破損をなくすことができる。
【００２０】
（参考例２）
本参考例のガラス破壊センサの基本構成は参考例１と略同様であり、同様の構成には同一の符号を付して説明は省略する。図５、図６は本参考例のハウジング１と円板状の圧電素子２との接着部分を示しており、ハウジング１は圧電素子２の接着面を囲むように圧電素子２の外周に沿って立設した円環状の壁１０を一体成形している。圧電素子２はこの一体成形した壁１０の内側でハウジング１に接着剤３で貼り付けられているので、周囲環境の温度変化によりハウジング１が図６中破線のように変形しようとしても壁１０の剛性によって接着面の変形（そり）を抑えることができ、接着面に平行なＸ１，Ｘ２方向に働く伸縮力も大幅に削減されている。
【００２１】
したがって、圧電素子２の接着面の変形は少なく、圧電素子２に歪みが伝わらないために硬度の高い接着剤３を使用しても圧電素子２の破損はない。尚、図５、図６の壁１０の平面形状は円となっているが、圧電素子を囲むことのできる形状であれば、その他の形状、例えば矩形であっても対応は可能である。
【００２２】
（実施形態１）
図７（ａ），（ｂ）は、本実施形態のハウジング１と円板状の圧電素子２との接着部分を示し、他の構成は参考例１または２と同様であり、同様の構成には同一の符号を付して説明は省略する。本実施形態のハウジング１の圧電素子２を接着する部分には、円形の凹部１２を形成し、凹部１２の底面上にその高さが予め定めた接着剤層の厚みＴ１と一致する凸部１１ａ〜１１ｃを３ヶ所配置する。凸部１１ａ〜１１ｃは、その各中心が圧電素子２の円形の接着面の中心位置に対して１２０°間隔となるように同心円上に配置され、圧電素子２はこの凸部１１ａ〜１１ｃに載置されてハウジング１に対する平行度を保っている。
【００２３】
ここで従来、図１８のように圧電素子２をハウジング１に接着剤３を使って固定する場合、硬化後の接着剤層厚みの管理が難しくセンサの振動検出感度にバラツキがあるという問題があった。しかし、本実施形態のように圧電素子２の接着部分に接着剤３を塗布し、圧電素子２を凸部１１ａ〜１１ｃ上に置いて接着剤３を硬化させると、接着剤層の厚みＴ１は凸部１１ａ〜１１ｃの高さで決まるため振動の伝達経路の厚み（接着剤層の厚みＴ１）が一定となり、センサの振動検出感度のバラツキは小さくなり、一定の範囲内に収まる。
【００２４】
また、凸部１１ａ〜１１ｃの代わりに図８に示す円環状の凸部１３や、図９に示す互いに平行に配置された１対の直線状の凸部１４ａ，１４ｂであってもよく、接着剤層の厚みＴ１及び圧電素子２のハウジング１に対する平行度を保つことできるものであればよい。
【００２５】
（実施形態２）
図１０（ａ），（ｂ）は、本実施形態のハウジング１と円板状の圧電素子２との接着部分を示し、他の構成は参考例１または２と同様であり、同様の構成には同一の符号を付して説明は省略する。本実施形態のハウジング１の圧電素子２を接着する部分には、円形の凹部１２を形成し、凹部１２よりその径が小さく、その深さが予め定めた接着剤層の厚みＴ１と一致する円形の凹部１５を凹部１２の底面に形成する。圧電素子２はその接着面の周縁部を凹部１２の円周部（台部）上に載置されてハウジング１に対する平行度を保っている。
【００２６】
ここで従来、図１８のように圧電素子２をハウジング１に接着剤３を使って固定する場合、硬化後の接着剤層厚みの管理が難しくセンサの振動検出感度にバラツキがあるという問題があった。しかし、本実施形態のように圧電素子２の接着部分に接着剤３を塗布し、圧電素子２を凹部１２の円周部上に置いて接着剤３を硬化させると、接着剤層の厚みＴ１は凹部１５の深さで決まるため振動の伝達経路の厚み（接着剤層の厚みＴ１）が一定となり、センサの振動検出感度のバラツキは小さくなり、一定の範囲内に収まる。
【００２７】
また、凹部１５の形状は四角等、接着剤層の厚みＴ１及び圧電素子２のハウジング１に対する平行度を保つことできる形状であればよい。
【００２８】
（実施形態３）
図１１、図１２は、本実施形態の圧電素子２を示し、他の構成は参考例１，２、実施形態１，２いずれかと同様であり、同様の構成には同一の符号を付して説明は省略する。本実施形態の圧電素子２は、径の異なる円板状の素子部２ａ，２ｂの一方の側端部同士を一致させて重ねた２段構成となっており、径が小さい素子部２ａの裏面は、非金属のハウジング１との接着面であると共に電極２１を全面に形成している。また素子部２ｂの表面にも素子部２ａと同径に形成されたもう一方の電極２１が形成される。ここで、圧電素子２の表裏面の各電極２１の径は、検出周波数での感度を確保するために検出周波数で決まる径Ｒ１となる。
【００２９】
そして素子部２ａの裏面の電極２１から素子部２ａの側面、素子部２ｂの裏面及び側面にまで延長した延長電極２３が形成されており、素子部２ｂの裏面の延長電極２３に予め電線を半田付けしておいてからハウジング１に貼り付け、回路部に配線する。素子部２ｂの表面に形成されたもう一方の電極２１も回路部に配線される。
【００３０】
ここで従来、図２のように折り返し電極２２の電極パターンの圧電素子２を製造する場合、セラミックを分極する際に２つの電極間同士の絶縁距離を確保するために圧電素子２の厚み相当の距離を開ける必要があるため、両面全面電極パターンに比べ感度が低いという問題があった。
【００３１】
しかし本実施形態では、圧電素子２の厚み方向は階段状に形成されているので、表裏面の各電極２１間の絶縁距離Ｚ１は十分に確保できると同時に、検出周波数で決まる電極２１の径Ｒ１の部分すべてが分極処理されるため、従来の折り返し電極パターンに比べて感度は向上する。なお、素子部２ｂ側面の延長電極２３は無くてもよい。
【００３２】
また図１３、図１４に示すように、径の異なる円板状の素子部２ａ，２ｂの中心同士を一致させて重ねた２段構成としても同様の効果を得ることができる。図１３、図１４では素子部２ｂ側面には延長電極２３はなく、表裏面の各電極２１間の絶縁距離Ｚ２となり、素子部２ｂ側面の延長電極２３がある場合の絶縁距離Ｚ１に比べて素子部２ｂの厚み分だけ絶縁距離を大きくとることができる。
【００３３】
さらに本実施形態では圧電素子２の厚み方向の形状を階段状にしてあるが、図１５に示すように素子部２ｂの側面を、表面に近付くにしたがって径が小さくなるスロープ状に形成しても問題は無い。
【００３４】
（実施形態４）
図１６、図１７は、本実施形態の圧電素子２を示し、他の構成は参考例１，２、実施形態１，２いずれかと同様であり、同様の構成には同一の符号を付して説明は省略する。本実施形態の圧電素子２は、同一径の円板状の素子部２ｄ，２ｆの間に素子部２ｅ，２ｆより径の大きい円板状の素子部２ｅを挟んだ３段構成となっており、素子部２ｄの表面及び素子部２ｆの裏面は電極２１を全面に形成しており、素子部２ｆの裏面を非金属のハウジング１との接着面としている。ここで、圧電素子２の表裏面の各電極２１の径は、検出周波数での感度を確保するために検出周波数で決まる径Ｒ１となる。
【００３５】
そして素子部２ｄの表面の電極２１から素子部２ｄの側面、素子部２ｅの表面にまで延長した延長電極２３、及び素子部２ｆの裏面の電極２１から素子部２ｆの側面、素子部２ｅの裏面にまで延長した延長電極２３が各々形成されており、素子部２ｆの裏面の延長電極２３に予め電線を半田付けしておいてからハウジング１に貼り付け、回路部に配線する。素子部２ｂの表面に形成されたもう一方の電極２１も回路部に配線される。
【００３６】
本実施形態では、素子部２ｅの厚みを表裏面の各電極２１間の絶縁距離Ｚ３としており、絶縁距離は十分に確保できると同時に、検出周波数で決まる電極２１の径Ｒ１の部分すべてが分極処理されるため、従来の折り返し電極パターンに比べて感度は向上する。さらに、実施形態３に比べて構造体の対称性を確保してあるため、スプリアスも抑えることができる。
【００３７】
【発明の効果】
請求項１の発明は、建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記接着剤は、硬化後の硬度がショア−硬度Ａで４０以下であり、前記ハウジングは、前記圧電素子が接着される箇所に、前記圧電素子を載置して予め定めた接着剤層の厚みに相当する同一高さの複数の凸部を備え、前記複数の凸部は、載置される前記圧電素子が前記ハウジングに対する平行度を維持できる箇所に各々配置されるので、ハウジングと圧電素子との間で接着剤が各々の線膨張係数の違いによる伸縮を吸収し、周囲環境の温度変化による圧電素子の破損を防止することができるという効果がある。さらには、ハウジングの寸法管理によって接着剤層の厚みを一定とすることで、センサの振動検出感度のバラツキを小さくして一定の範囲内に収めることができるという効果がある。
【００３８】
請求項２の発明は、建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記接着剤は、硬化後の硬度がショア−硬度Ａで４０以下であり、前記ハウジングは、前記圧電素子が接着される箇所に、前記圧電素子の接着面の周縁部を載置する台部と、前記台部の内側に形成されて予め定めた接着剤層の厚みに相当する一定深さの凹部とを備え、前記台部は、載置された前記圧電素子が前記ハウジングに対する平行度を維持できる形状に形成されるので、ハウジングと圧電素子との間で接着剤が各々の線膨張係数の違いによる伸縮を吸収し、周囲環境の温度変化による圧電素子の破損を防止することができるという効果がある。さらには、ハウジングの寸法管理によって接着剤層の厚みを一定とすることで、センサの振動検出感度のバラツキを小さくして一定の範囲内に収めることができるという効果がある。
【００３９】
請求項３の発明は、建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記ハウジングは、前記圧電素子の接着面を囲むように前記圧電素子の周囲に立設した壁を有するとともに、前記圧電素子が接着される箇所に、前記圧電素子を載置して予め定めた接着剤層の厚みに相当する同一高さの複数の凸部を備え、前記複数の凸部は、載置される前記圧電素子が前記ハウジングに対する平行度を維持できる箇所に各々配置されるので、周囲環境の温度変化による圧電素子の接着面の変形は少なく、圧電素子の破損を防止することができるという効果がある。さらには、ハウジングの寸法管理によって接着剤層の厚みを一定とすることで、センサの振動検出感度のバラツキを小さくして一定の範囲内に収めることができるという効果がある。
【００４０】
請求項４の発明は、建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記ハウジングは、前記圧電素子の接着面を囲むように前記圧電素子の周囲に立設した壁を有するとともに、前記圧電素子が接着される箇所に、前記圧電素子の接着面の周縁部を載置する台部と、前記台部の内側に形成されて予め定めた接着剤層の厚みに相当する一定深さの凹部とを備え、前記台部は、載置された前記圧電素子が前記ハウジングに対する平行度を維持できる形状に形成されるので、周囲環境の温度変化による圧電素子の接着面の変形は少なく、圧電素子の破損を防止することができるという効果がある。さらには、ハウジングの寸法管理によって接着剤層の厚みを一定とすることで、センサの振動検出感度のバラツキを小さくして一定の範囲内に収めることができるという効果がある。
【００４１】
請求項５の発明は、請求項１乃至４いずれかにおいて、前記圧電素子は、接着面と該接着面に対向する面とに各々電極を設け、外面の少なくとも一部を前記電極の対向方向に段差を設けた階段形状としたので、圧電素子の感度を低下させることなく容易に電極を取り出すことができるという効果がある。
【００４２】
請求項６の発明は、請求項１乃至４いずれかにおいて、前記圧電素子は、少なくとも一方面に電極を各々形成した第１，第２の素子部の各他方面間に第３の素子部を挟んだ３段構成となり、第１，第２の素子部に各々設けた電極間の絶縁距離は、少なくとも第１，第２の素子部間の第３の素子部の厚みを含むので、圧電素子の感度を低下させることなく電極間の絶縁距離をとることができるという効果がある。
【図面の簡単な説明】
【図１】（ａ）本発明の参考例１のガラス破壊センサを示す外観構成図である。
（ｂ）同上の回路構成図である
【図２】同上の圧電素子近傍の斜視図である。
【図３】同上の圧電素子近傍の側面図である。
【図４】同上の各種接着剤に対する熱衝撃試験の結果を示す図である。
【図５】本発明の参考例２の圧電素子近傍の斜視図である。
【図６】同上のハウジングの変形を示す側面断面図である。
【図７】（ａ）本発明の実施形態１の第１の圧電素子近傍の表面図である。
（ｂ）同上の第１の圧電素子近傍の側面断面図である。
【図８】同上の第２の圧電素子近傍の表面図である。
【図９】同上の第３の圧電素子近傍の表面図である。
【図１０】（ａ）本発明の実施形態２の圧電素子近傍の表面図である。
（ｂ）同上の圧電素子近傍の断面図である。
【図１１】本発明の実施形態３の第１の圧電素子の構成を示す図である。
【図１２】同上の第１の圧電素子の斜視図である。
【図１３】同上の第２の圧電素子の構成を示す図である。
【図１４】同上の第２の圧電素子の斜視図である。
【図１５】同上の第３の圧電素子の斜視図である。
【図１６】本発明の実施形態４の圧電素子の構成を示す図である。
【図１７】同上の圧電素子の斜視図である。
【図１８】従来例の圧電素子とハウジングとの接着を示す図である。
【図１９】同上のハウジングの変形を示す側面図である。
【符号の説明】
１ハウジング
２圧電素子
３接着剤
Ｇガラス
Ｓ１ハイパスフィルタ回路
Ｓ２比較判断部
Ｓ３警報出力部
Ｖｔｈ警報閾値電圧[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a glass breakage sensor that is attached to a glass plate that partitions the interior and the exterior and detects the breakage of the glass plate.
[0002]
[Prior art]
Conventionally, it is attached to a glass plate that divides the interior and exterior of the room, such as a window glass and a glass door. When a person trying to enter the room (hereinafter referred to as an intruder) breaks the glass plate, this is detected and notified by sound or light. A glass break sensor for crime prevention is provided. This type of glass breakage sensor uses a piezoelectric element that converts the vibration of a glass plate into a voltage signal as vibration detection means, and outputs an alarm if the amplitude of the output signal of the piezoelectric element is larger than the alarm threshold. As shown in FIGS. 2 and 3, when the housing 1 that forms the outline of the glass breaking sensor and is attached to the glass plate is a molded product, the disk-shaped piezoelectric element 2 is attached to the housing 1 with the adhesive 3. It was.
[0003]
Further, when the piezoelectric element 2 is fixed to the housing 1 using the adhesive 3, as shown in FIG. 18, the adhesive layer is controlled by managing the application amount of the adhesive 3 and the load applied to the piezoelectric element 2 at the time of curing. The thickness was controlled.
[0004]
Alternatively, a concave portion is provided on the adhesive surface of the housing to form an adhesive layer according to the depth of the concave portion, or a convex portion is provided on the adhesive surface of the housing, and an adhesive layer according to the height of the convex portion is provided. Or controlling the thickness of the adhesive layer. (For example, refer to Patent Document 1.)
Further, as shown in FIG. 2, the piezoelectric element 2 has electrodes 21 formed on a bonding surface (back surface) to the housing 1 and a surface (front surface) opposite to the bonding surface, and is bonded to the nonmetallic housing 1. In this case, in order to take out a signal from the electrode 21 on the back surface bonded to the housing 1, an electrode pattern of the folded electrode 22 extending from the electrode 21 on the back surface of the piezoelectric element 2 to the side surface and extending to the surface side of the piezoelectric element 2 is formed. ing. The surface electrode 21 and the folded electrode 22 are each electrically connected to the circuit portion via the electric wire 5.
[0005]
[Patent Document 1]
JP-A-6-61276 (page 2, left column, lines 24 to 27, page 2, right column, lines 19 to 48, FIGS. 1 to 4)
[0006]
[Problems to be solved by the invention]
However, the above-described conventional glass breakage sensor uses an epoxy adhesive having a high hardness as the adhesive 3, and when the piezoelectric element 2 is attached to the housing 1 of the molded product, as shown in FIG. The housing 1 is deformed as indicated by a broken line in the figure due to the temperature change, and the distortion (for example, the Y1 and Y2 directions perpendicular to the bonding surface) is transmitted to the piezoelectric element 2 through the adhesive 3, and the housing 1 and the adhesive 3 and the piezoelectric element 2 have a problem in that the piezoelectric element 2 cannot follow the deformation of the housing 1 and is damaged due to the difference in linear expansion coefficient.
[0007]
This invention is made | formed in view of the said reason, The objective is to provide the glass breakage sensor which prevented the failure | damage of the piezoelectric element by the temperature change of ambient environment.
[0008]
[Means for Solving the Problems]
The invention of claim 1 includes a housing attached to a glass plate that partitions the interior and exterior of a building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, and a notification unit amplitude of the output signal of the piezoelectric element to output an alarm greater, the adhesive, the hardness after curing Shore - Ri der 40 or less in hardness a, the housing, wherein the piezoelectric element is bonded A plurality of convex portions having the same height corresponding to a predetermined thickness of the adhesive layer by placing the piezoelectric element at a place where the piezoelectric element is placed. It is respectively arranged at the place which can maintain the parallelism to the housing .
[0009]
According to a second aspect of the present invention, there is provided a housing attached to a glass plate that partitions the interior and exterior of a building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, A warning means for outputting an alarm if the amplitude of the output signal of the piezoelectric element is large, and the adhesive has a hardness after curing of Shore-A hardness of 40 or less, and the housing is bonded to the piezoelectric element. A base part for mounting a peripheral part of the bonding surface of the piezoelectric element, and a concave part having a constant depth corresponding to a predetermined thickness of the adhesive layer formed inside the base part, The base portion is formed in a shape in which the mounted piezoelectric element can maintain parallelism with the housing .
[0010]
According to a third aspect of the present invention, there is provided a housing attached to a glass plate that partitions the interior and exterior of a building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, Informing means for outputting an alarm if the amplitude of the output signal of the piezoelectric element is large, the housing has a wall erected around the piezoelectric element so as to surround the bonding surface of the piezoelectric element, and the piezoelectric element A plurality of convex portions having the same height corresponding to the thickness of the adhesive layer that is predetermined by placing the piezoelectric element on the element is provided, and the plurality of convex portions are placed The piezoelectric elements are respectively arranged at locations where parallelism with the housing can be maintained .
[0011]
According to a fourth aspect of the present invention, there is provided a housing attached to a glass plate that partitions the interior and exterior of a building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, Informing means for outputting an alarm if the amplitude of the output signal of the piezoelectric element is large, the housing has a wall erected around the piezoelectric element so as to surround the bonding surface of the piezoelectric element, and the piezoelectric element A base part on which the peripheral edge of the bonding surface of the piezoelectric element is placed at a position where the element is bonded, and a concave part formed inside the base part and having a predetermined depth corresponding to the thickness of a predetermined adhesive layer The pedestal is formed in a shape that allows the mounted piezoelectric element to maintain parallelism with the housing .
[0012]
According to a fifth aspect of the present invention, in the piezoelectric element according to any one of the first to fourth aspects, the piezoelectric element is provided with an electrode on each of a bonding surface and a surface facing the bonding surface, and at least a part of the outer surface is provided in a direction opposite to the electrode. It is characterized by a staircase shape with steps.
[0013]
According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the piezoelectric element includes a third element portion between the other surfaces of the first and second element portions each having an electrode formed on at least one surface. It has a three-stage structure, and the insulation distance between the electrodes provided in the first and second element parts includes at least the thickness of the third element part between the first and second element parts. To do.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
( Reference Example 1 )
As shown in FIG. 1A, the glass break sensor of this reference example is a circle that is fixed in a molded product housing 1 that is attached to the glass plate G by a double-sided adhesive sheet, and converts the vibration of the glass plate G into a voltage signal. A plate-like piezoelectric element 2 is provided, and an alarm is output if the amplitude of the output signal of the piezoelectric element 2 is larger than the alarm threshold, and the configuration of the circuit portion is as shown in FIG. A high-pass filter circuit S1 having a cut-off frequency set to such an extent that a frequency related to the destruction of the glass plate G of the output signal of the piezoelectric element 2 passes and a noise is removed. The comparison determination unit S2 that compares the output of the filter circuit S1 with the alarm threshold voltage Vth and the determination result of the comparison determination unit S2 indicate that the output of the high-pass filter circuit S1 is larger than the alarm threshold voltage Vth. It consists alarm output Portion S3 Metropolitan that emits play alarm.
[0016]
The piezoelectric element 2 is attached to the housing 1 with an adhesive 3 as shown in FIGS. 2 and 3, and the surface electrode 21 and the folded electrode 22 are respectively connected to the housing 1 via the electric wire 5 as shown in FIG. It is electrically connected to the circuit portion shown in FIG.
[0017]
This reference example differs from the conventional example in that an adhesive 3 having a Shore hardness of A = 40 or less, for example, a silicon-based adhesive is used.
[0018]
Next, with respect to a sample in which the piezoelectric element 2 is bonded to the molded housing 1 with adhesives 3 having different hardnesses, in order to confirm whether or not the piezoelectric element 2 is damaged with respect to temperature changes in the surrounding environment, The presence or absence of damage was confirmed by an impact test. As a sample, adhesive 3a: Shore-hardness D = 89 (Shore-hardness A = 90 or more), adhesive 3b: Shore-hardness D = 75 (Shore-hardness A = 90 or more), adhesive 3c: Shore-hardness Four types of D = 40 (Shore-Hardness A = 90) and adhesive 3d: Shore-Hardness A = 40 were prepared. The test conditions were -40 ° C. to 80 ° C. extended by 25 ° C. on both the low temperature side and high temperature side with respect to the operating temperature range, and strict conditions of 50 cycles.
[0019]
The results of the thermal shock test are as shown in FIG. 4. In the sample using the adhesives 3a and 3b, the piezoelectric element 2 is divided into two in the thickness direction, and the sample using the adhesive 3c is a part of the sample. Was damaged or the sensitivity was deteriorated due to peeling of the electrode part. However, the sample using the adhesive 3d was neither damaged nor deteriorated in sensitivity. Therefore, in this reference example , when the adhesive 3 has a Shore hardness of A = 40 or less, the adhesive 3 absorbs expansion and contraction due to the difference in linear expansion coefficient between the housing 1 and the piezoelectric element 2. Thus, damage to the piezoelectric element 2 can be eliminated.
[0020]
( Reference Example 2 )
The basic configuration of the glass breakage sensor of the present reference example is substantially the same as that of the reference example 1, and the same components are denoted by the same reference numerals and description thereof is omitted. 5 and 6 show a bonded portion between the housing 1 and the disk-shaped piezoelectric element 2 of this reference example , and the housing 1 extends along the outer periphery of the piezoelectric element 2 so as to surround the bonded surface of the piezoelectric element 2. A standing annular wall 10 is integrally formed. Since the piezoelectric element 2 is adhered to the housing 1 with the adhesive 3 inside the integrally formed wall 10, even if the housing 1 is deformed as shown by a broken line in FIG. The deformation (warping) of the bonding surface can be suppressed by the rigidity, and the stretching force acting in the X1 and X2 directions parallel to the bonding surface is also greatly reduced.
[0021]
Therefore, the deformation of the bonding surface of the piezoelectric element 2 is small, and since no distortion is transmitted to the piezoelectric element 2, the piezoelectric element 2 is not damaged even when the adhesive 3 having high hardness is used. The planar shape of the wall 10 shown in FIGS. 5 and 6 is a circle, but other shapes such as a rectangle can be used as long as the shape can surround the piezoelectric element.
[0022]
( Embodiment 1 )
FIGS. 7A and 7B show an adhesion portion between the housing 1 and the disk-shaped piezoelectric element 2 of the present embodiment, and the other configurations are the same as those in Reference Example 1 or 2, and the same configurations are used. Are denoted by the same reference numerals and description thereof is omitted. A circular concave portion 12 is formed in a portion to which the piezoelectric element 2 of the housing 1 of the present embodiment is bonded, and a convex portion 11a whose height coincides with a predetermined thickness T1 of the adhesive layer on the bottom surface of the concave portion 12. ˜11c are arranged in three places. The convex portions 11a to 11c are arranged concentrically so that the centers thereof are spaced 120 ° from the center position of the circular bonding surface of the piezoelectric element 2, and the piezoelectric element 2 is mounted on the convex portions 11a to 11c. The parallelism with respect to the housing 1 is maintained.
[0023]
Conventionally, when the piezoelectric element 2 is fixed to the housing 1 using the adhesive 3 as shown in FIG. 18, there is a problem that the thickness of the adhesive layer after curing is difficult to control and the vibration detection sensitivity of the sensor varies. It was. However, when the adhesive 3 is applied to the adhesion portion of the piezoelectric element 2 as in the present embodiment, and the adhesive 3 is cured by placing the piezoelectric element 2 on the convex portions 11a to 11c, the thickness T1 of the adhesive layer is Since the thickness is determined by the height of the convex portions 11a to 11c, the thickness of the vibration transmission path (the thickness T1 of the adhesive layer) becomes constant, and the variation in the vibration detection sensitivity of the sensor becomes small and falls within a certain range.
[0024]
Further, instead of the convex portions 11a to 11c, the annular convex portion 13 shown in FIG. 8 or a pair of linear convex portions 14a and 14b arranged in parallel to each other shown in FIG. Any material that can maintain the thickness T1 of the agent layer and the parallelism of the piezoelectric element 2 to the housing 1 may be used.
[0025]
( Embodiment 2 )
FIGS. 10A and 10B show an adhesion portion between the housing 1 and the disk-like piezoelectric element 2 of the present embodiment, and the other configurations are the same as those in Reference Example 1 or 2, and the same configurations are used. Are denoted by the same reference numerals and description thereof is omitted. A circular concave portion 12 is formed in a portion to which the piezoelectric element 2 of the housing 1 of the present embodiment is bonded, the diameter of the concave portion 12 is smaller than that of the concave portion 12, and the depth of the circular concave portion matches the predetermined thickness T1 of the adhesive layer. The recess 15 is formed on the bottom surface of the recess 12. The piezoelectric element 2 is mounted on the circumferential portion (base) of the recess 12 with the peripheral edge of the bonding surface thereof, and maintains parallelism with the housing 1.
[0026]
Conventionally, when the piezoelectric element 2 is fixed to the housing 1 using the adhesive 3 as shown in FIG. 18, there is a problem that the thickness of the adhesive layer after curing is difficult to control and the vibration detection sensitivity of the sensor varies. It was. However, when the adhesive 3 is applied to the bonded portion of the piezoelectric element 2 as in the present embodiment, and the adhesive 3 is cured by placing the piezoelectric element 2 on the circumferential portion of the recess 12, the thickness T1 of the adhesive layer Is determined by the depth of the recess 15, the thickness of the vibration transmission path (adhesive layer thickness T1) becomes constant, and the variation in the vibration detection sensitivity of the sensor becomes small and falls within a certain range.
[0027]
Moreover, the shape of the recessed part 15 should just be a shape which can maintain the parallelism with respect to the housing 1 of thickness T1 of an adhesive bond layer and the piezoelectric element 2, such as a square.
[0028]
( Embodiment 3 )
11 and 12 show the piezoelectric element 2 of the present embodiment, and other configurations are the same as those of the reference examples 1 and 2 and the embodiments 1 and 2, and the same configurations are denoted by the same reference numerals. Description is omitted. The piezoelectric element 2 of the present embodiment has a two-stage configuration in which one side end portions of disk-shaped element portions 2a and 2b having different diameters are overlapped with each other, and the back surface of the element portion 2a having a small diameter. Is an adhesion surface with the non-metallic housing 1 and the electrode 21 is formed on the entire surface. The other electrode 21 having the same diameter as the element portion 2a is also formed on the surface of the element portion 2b. Here, the diameter of each electrode 21 on the front and back surfaces of the piezoelectric element 2 is a diameter R1 determined by the detection frequency in order to ensure sensitivity at the detection frequency.
[0029]
An extension electrode 23 extending from the electrode 21 on the back surface of the element portion 2a to the side surface of the element portion 2a, the back surface and the side surface of the element portion 2b is formed, and a wire is previously soldered to the extension electrode 23 on the back surface of the element portion 2b. After being attached, it is attached to the housing 1 and wired to the circuit portion. The other electrode 21 formed on the surface of the element portion 2b is also wired to the circuit portion.
[0030]
Here, conventionally, when the piezoelectric element 2 having the electrode pattern of the folded electrode 22 as shown in FIG. 2 is manufactured, in order to secure an insulation distance between the two electrodes when the ceramic is polarized, it corresponds to the thickness of the piezoelectric element 2. Since it is necessary to increase the distance, there is a problem that the sensitivity is lower than that of the double-sided full-surface electrode pattern.
[0031]
However, in the present embodiment, the thickness direction of the piezoelectric element 2 is formed in a stepped shape, so that a sufficient insulation distance Z1 between the electrodes 21 on the front and back surfaces can be secured, and at the same time, the diameter R1 of the electrode 21 determined by the detection frequency. Since all the portions are polarized, the sensitivity is improved as compared with the conventional folded electrode pattern. The extension electrode 23 on the side surface of the element portion 2b may not be provided.
[0032]
Further, as shown in FIGS. 13 and 14, the same effect can be obtained even in a two-stage configuration in which the centers of the disk-shaped element portions 2a and 2b having different diameters are aligned with each other. 13 and 14, there is no extension electrode 23 on the side surface of the element portion 2b, and the insulation distance Z2 between the respective electrodes 21 on the front and back surfaces becomes an element compared with the insulation distance Z1 when the extension electrode 23 on the side surface of the element portion 2b is present. The insulation distance can be increased by the thickness of the portion 2b.
[0033]
Further, in the present embodiment, the shape of the piezoelectric element 2 in the thickness direction is stepped. However, as shown in FIG. 15, the side surface of the element portion 2b may be formed in a slope shape in which the diameter decreases as it approaches the surface. There is no problem.
[0034]
( Embodiment 4 )
FIGS. 16 and 17 show the piezoelectric element 2 of the present embodiment, and other configurations are the same as those of any one of the reference examples 1 and 2 and the embodiments 1 and 2, and the same configurations are denoted by the same reference numerals. Description is omitted. The piezoelectric element 2 of the present embodiment has a three-stage configuration in which a disk-shaped element part 2e having a larger diameter than the element parts 2e and 2f is sandwiched between disk-shaped element parts 2d and 2f having the same diameter. The front surface of the element portion 2d and the back surface of the element portion 2f are formed with electrodes 21 over the entire surface, and the back surface of the element portion 2f is used as an adhesive surface with the non-metallic housing 1. Here, the diameter of each electrode 21 on the front and back surfaces of the piezoelectric element 2 is a diameter R1 determined by the detection frequency in order to ensure sensitivity at the detection frequency.
[0035]
And the extended electrode 23 extended from the electrode 21 on the surface of the element part 2d to the side surface of the element part 2d, the surface of the element part 2e, and the side surface of the element part 2f from the electrode 21 on the back surface of the element part 2f, the back surface of the element part 2e The extension electrodes 23 are formed so as to extend up to, and an electric wire is soldered in advance to the extension electrode 23 on the back surface of the element portion 2f, and then attached to the housing 1 and wired to the circuit portion. The other electrode 21 formed on the surface of the element portion 2b is also wired to the circuit portion.
[0036]
In the present embodiment, the thickness of the element portion 2e is the insulation distance Z3 between the electrodes 21 on the front and back surfaces, and the insulation distance can be sufficiently secured, and at the same time, all the portions of the diameter R1 of the electrode 21 determined by the detection frequency are polarized. Therefore, the sensitivity is improved as compared with the conventional folded electrode pattern. Furthermore, since the symmetry of the structure is ensured compared to the third embodiment , spurious can be suppressed.
[0037]
【The invention's effect】
The invention of claim 1 includes a housing attached to a glass plate that partitions the interior and exterior of a building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, and a notification unit amplitude of the output signal of the piezoelectric element to output an alarm greater, the adhesive, the hardness after curing Shore - Ri der 40 or less in hardness a, the housing, wherein the piezoelectric element is bonded A plurality of convex portions having the same height corresponding to a predetermined thickness of the adhesive layer by placing the piezoelectric element at a place where the piezoelectric element is placed. because are each disposed at a position capable of maintaining parallelism with respect to the housing, to absorb the expansion and contraction due to the difference adhesive of linear expansion coefficient of each between the housing and the piezoelectric element, the piezoelectric element due to temperature changes in the surrounding environment There is an effect that it is possible to prevent the loss. Further, by making the thickness of the adhesive layer constant by managing the dimensions of the housing, there is an effect that the variation in the vibration detection sensitivity of the sensor can be reduced and kept within a certain range.
[0038]
According to a second aspect of the present invention, there is provided a housing attached to a glass plate that partitions the interior and exterior of a building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, and a notification unit amplitude of the output signal of the piezoelectric element to output an alarm greater, the adhesive, the hardness after curing Shore - is the hardness a 40 or less, the housings, the piezoelectric element is bonded At a place where a peripheral portion of the adhesive surface of the piezoelectric element is placed, and a concave portion formed inside the base portion and having a predetermined depth corresponding to a predetermined thickness of the adhesive layer. The base portion is formed in a shape that allows the mounted piezoelectric element to maintain parallelism with the housing, so that the adhesive expands and contracts between the housing and the piezoelectric element due to the difference in coefficient of linear expansion. Absorb There is an effect that it is possible to prevent damage to the piezoelectric element due to temperature changes in the surrounding environment. Further, by making the thickness of the adhesive layer constant by managing the dimensions of the housing, there is an effect that the variation in the vibration detection sensitivity of the sensor can be reduced and kept within a certain range.
[0039]
According to a third aspect of the present invention, there is provided a housing attached to a glass plate that partitions the interior and exterior of a building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, Informing means for outputting an alarm if the amplitude of the output signal of the piezoelectric element is large, the housing has a wall erected around the piezoelectric element so as to surround the bonding surface of the piezoelectric element, and the piezoelectric element A plurality of convex portions having the same height corresponding to the thickness of the adhesive layer that is predetermined by placing the piezoelectric element on the element is provided, and the plurality of convex portions are placed Since the piezoelectric elements are arranged at locations where the parallelism with respect to the housing can be maintained, the deformation of the bonding surface of the piezoelectric elements due to the temperature change of the surrounding environment is small, and damage to the piezoelectric elements can be prevented There is an effect that. Further, by making the thickness of the adhesive layer constant by managing the dimensions of the housing, there is an effect that the variation in the vibration detection sensitivity of the sensor can be reduced and kept within a certain range.
[0040]
According to a fourth aspect of the present invention, there is provided a housing attached to a glass plate that partitions the interior and exterior of a building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, Informing means for outputting an alarm if the amplitude of the output signal of the piezoelectric element is large, the housing has a wall erected around the piezoelectric element so as to surround the bonding surface of the piezoelectric element, and the piezoelectric element A base part on which the peripheral edge of the bonding surface of the piezoelectric element is placed at a position where the element is bonded, and a concave part formed inside the base part and having a predetermined depth corresponding to the thickness of a predetermined adhesive layer And the base portion is formed in a shape that allows the mounted piezoelectric element to maintain parallelism with the housing, so that deformation of the adhesive surface of the piezoelectric element due to temperature change in the surrounding environment is small, There is an effect that it is possible to prevent damage to the conductive elements. Further, by making the thickness of the adhesive layer constant by managing the dimensions of the housing, there is an effect that the variation in the vibration detection sensitivity of the sensor can be reduced and kept within a certain range.
[0041]
According to a fifth aspect of the present invention, in the piezoelectric element according to any one of the first to fourth aspects, the piezoelectric element is provided with an electrode on each of a bonding surface and a surface facing the bonding surface, and at least a part of the outer surface is provided in a direction opposite to the electrode. Since the stepped shape is provided with a step, the electrode can be easily taken out without reducing the sensitivity of the piezoelectric element.
[0042]
According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the piezoelectric element includes a third element portion between the other surfaces of the first and second element portions each having an electrode formed on at least one surface. Since it has a three-stage structure, and the insulation distance between the electrodes provided in the first and second element portions includes at least the thickness of the third element portion between the first and second element portions. There is an effect that the insulation distance between the electrodes can be taken without lowering the sensitivity.
[Brief description of the drawings]
FIG. 1A is an external configuration diagram showing a glass breakage sensor of Reference Example 1 of the present invention.
FIG. 2B is a perspective view of the vicinity of the piezoelectric element.
FIG. 3 is a side view of the vicinity of the piezoelectric element.
FIG. 4 is a diagram showing the results of a thermal shock test on various adhesives as described above.
FIG. 5 is a perspective view of the vicinity of a piezoelectric element according to Reference Example 2 of the present invention.
FIG. 6 is a side sectional view showing a modification of the housing.
7A is a surface view in the vicinity of a first piezoelectric element according to the first embodiment of the present invention. FIG.
(B) It is side surface sectional drawing of the 1st piezoelectric element vicinity same as the above.
FIG. 8 is a surface view of the vicinity of the second piezoelectric element.
FIG. 9 is a surface view of the vicinity of the third piezoelectric element of the above.
FIG. 10A is a surface view of the vicinity of a piezoelectric element according to a second embodiment of the present invention.
(B) It is sectional drawing of the piezoelectric element vicinity of the same as the above.
FIG. 11 is a diagram illustrating a configuration of a first piezoelectric element according to a third embodiment of the present invention.
FIG. 12 is a perspective view of the first piezoelectric element same as above.
FIG. 13 is a diagram showing a configuration of a second piezoelectric element same as above.
FIG. 14 is a perspective view of the second piezoelectric element same as above.
FIG. 15 is a perspective view of a third piezoelectric element same as above.
FIG. 16 is a diagram showing a configuration of a piezoelectric element according to a fourth embodiment of the present invention.
FIG. 17 is a perspective view of the above piezoelectric element.
FIG. 18 is a diagram showing adhesion between a conventional piezoelectric element and a housing.
FIG. 19 is a side view showing a modification of the housing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 2 Piezoelectric element 3 Adhesive G Glass S1 High pass filter circuit S2 Comparison judgment part S3 Alarm output part Vth Alarm threshold voltage

Claims

建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記接着剤は、硬化後の硬度がショア−硬度Ａで４０以下であり、前記ハウジングは、前記圧電素子が接着される箇所に、前記圧電素子を載置して予め定めた接着剤層の厚みに相当する同一高さの複数の凸部を備え、前記複数の凸部は、載置される前記圧電素子が前記ハウジングに対する平行度を維持できる箇所に各々配置されることを特徴とするガラス破壊センサ。A housing attached to a glass plate that partitions the interior and exterior of the building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, and an amplitude of the output signal of the piezoelectric element that is higher than an alarm threshold and a notification unit for outputting an alarm if is large, the adhesive, the hardness after curing Shore - Ri der 40 or less in hardness a, the housing, the location where the piezoelectric element is bonded, the piezoelectric A plurality of convex portions having the same height corresponding to the thickness of the adhesive layer determined in advance by mounting the element are provided, and the plurality of convex portions maintain the parallelism of the mounted piezoelectric element with the housing. A glass breakage sensor, wherein the glass breakage sensor is arranged at a place where it can be formed .

建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記接着剤は、硬化後の硬度がショア−硬度Ａで４０以下であり、前記ハウジングは、前記圧電素子が接着される箇所に、前記圧電素子の接着面の周縁部を載置する台部と、前記台部の内側に形成されて予め定めた接着剤層の厚みに相当する一定深さの凹部とを備え、前記台部は、載置された前記圧電素子が前記ハウジングに対する平行度を維持できる形状に形成されることを特徴とするガラス破壊センサ。A housing attached to a glass plate that partitions the interior and exterior of the building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, and an amplitude of the output signal of the piezoelectric element that is higher than an alarm threshold A warning means for outputting an alarm if the pressure is large, the adhesive has a hardness after curing of Shore-hardness A of 40 or less, and the housing is provided at a location where the piezoelectric element is bonded. A base portion on which the peripheral edge of the adhesive surface is placed, and a concave portion formed inside the base portion and having a predetermined depth corresponding to a predetermined thickness of the adhesive layer, the base portion being placed The glass breakage sensor , wherein the piezoelectric element formed is formed in a shape capable of maintaining parallelism with the housing .

建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記ハウジングは、前記圧電素子の接着面を囲むように前記圧電素子の周囲に立設した壁を有するとともに、前記圧電素子が接着される箇所に、前記圧電素子を載置して予め定めた接着剤層の厚みに相当する同一高さの複数の凸部を備え、前記複数の凸部は、載置される前記圧電素子が前記ハウジングに対する平行度を維持できる箇所に各々配置されることを特徴とするガラス破壊センサ。A housing attached to a glass plate that partitions the interior and exterior of the building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, and an amplitude of the output signal of the piezoelectric element that is higher than an alarm threshold And a notification means for outputting an alarm if the size is large, the housing has a wall erected around the piezoelectric element so as to surround the bonding surface of the piezoelectric element, and at a location where the piezoelectric element is bonded. And a plurality of convex portions having the same height corresponding to a predetermined thickness of the adhesive layer on which the piezoelectric element is mounted, the plurality of convex portions being parallel to the housing. Each glass breakage sensor is arranged at a place where the degree can be maintained.

建物において室内外を仕切るガラス板に取り付けられるハウジングと、前記ハウジングに接着剤で固定されて前記ガラス板の振動を電圧信号に変換する圧電素子と、警報閾値よりも前記圧電素子の出力信号の振幅が大きければ警報を出力する報知手段とを備え、前記ハウジングは、前記圧電素子の接着面を囲むように前記圧電素子の周囲に立設した壁を有するとともに、前記圧電素子が接着される箇所に、前記圧電素子の接着面の周縁部を載置する台部と、前記台部の内側に形成されて予め定めた接着剤層の厚みに相当する一定深さの凹部とを備え、前記台部は、載置された前記圧電素子が前記ハウジングに対する平行度を維持できる形状に形成されることを特徴とするガラス破壊センサ。A housing attached to a glass plate that partitions the interior and exterior of the building, a piezoelectric element that is fixed to the housing with an adhesive and converts vibrations of the glass plate into a voltage signal, and an amplitude of the output signal of the piezoelectric element that is higher than an alarm threshold And a notification means for outputting an alarm if the size is large, the housing has a wall erected around the piezoelectric element so as to surround the bonding surface of the piezoelectric element, and at a location where the piezoelectric element is bonded. A base portion on which a peripheral portion of the bonding surface of the piezoelectric element is placed; and a concave portion formed inside the base portion and having a predetermined depth corresponding to a predetermined thickness of the adhesive layer; Is a glass breakage sensor, wherein the mounted piezoelectric element is formed in a shape capable of maintaining parallelism with the housing.

前記圧電素子は、接着面と該接着面に対向する面とに各々電極を設け、外面の少なくとも一部を前記電極の対向方向に段差を設けた階段形状としたことを特徴とする請求項１乃至４いずれか記載のガラス破壊センサ。 2. The piezoelectric element according to claim 1, wherein an electrode is provided on each of an adhesive surface and a surface opposite to the adhesive surface, and at least a part of the outer surface has a stepped shape in which a step is provided in the opposing direction of the electrode. The glass breakage sensor in any one of thru | or 4.

前記圧電素子は、少なくとも一方面に電極を各々形成した第１，第２の素子部の各他方面間に第３の素子部を挟んだ３段構成となり、第１，第２の素子部に各々設けた電極間の絶縁距離は、少なくとも第１，第２の素子部間の第３の素子部の厚みを含むことを特徴とする請求項１乃至４いずれか記載のガラス破壊センサ。 The piezoelectric element has a three-stage configuration in which a third element portion is sandwiched between the other surfaces of first and second element portions each having an electrode formed on at least one surface. The glass breakage sensor according to any one of claims 1 to 4 , wherein the insulation distance between the electrodes provided includes at least the thickness of the third element portion between the first and second element portions .