JPH0436324B2 - - Google Patents
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- Publication number
- JPH0436324B2 JPH0436324B2 JP59192318A JP19231884A JPH0436324B2 JP H0436324 B2 JPH0436324 B2 JP H0436324B2 JP 59192318 A JP59192318 A JP 59192318A JP 19231884 A JP19231884 A JP 19231884A JP H0436324 B2 JPH0436324 B2 JP H0436324B2
- Authority
- JP
- Japan
- Prior art keywords
- piezoelectric
- piezoelectric layer
- cable
- electrode
- layer
- 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.)
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- 239000000463 material Substances 0.000 claims description 20
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 18
- 239000000919 ceramic Substances 0.000 claims description 5
- 239000002131 composite material Substances 0.000 claims description 5
- 230000035882 stress Effects 0.000 description 7
- 230000010287 polarization Effects 0.000 description 6
- NKZSPGSOXYXWQA-UHFFFAOYSA-N dioxido(oxo)titanium;lead(2+) Chemical compound [Pb+2].[O-][Ti]([O-])=O NKZSPGSOXYXWQA-UHFFFAOYSA-N 0.000 description 4
- 229920001971 elastomer Polymers 0.000 description 4
- 239000005060 rubber Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000006355 external stress Effects 0.000 description 3
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 3
- 239000011368 organic material Substances 0.000 description 3
- 239000003973 paint Substances 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920002379 silicone rubber Polymers 0.000 description 2
- 239000004945 silicone rubber Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 241000251468 Actinopterygii Species 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 229920001328 Polyvinylidene chloride Polymers 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 230000001151 other effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920002620 polyvinyl fluoride Polymers 0.000 description 1
- 239000005033 polyvinylidene chloride Substances 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 229920003051 synthetic elastomer Polymers 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 239000005061 synthetic rubber Substances 0.000 description 1
- 238000004506 ultrasonic cleaning Methods 0.000 description 1
Landscapes
- Geophysics And Detection Of Objects (AREA)
- Insulated Conductors (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、海底地震探査や魚群探知用のハイド
ロフオン、または超音波洗浄装置の洗浄液内にお
ける音響測定子等に好適に利用される水中用圧電
ケーブルに関する。[Detailed Description of the Invention] <Industrial Application Field> The present invention is suitable for use in underwater applications such as hydrophons for submarine seismic exploration and fish detection, or acoustic probes in the cleaning liquid of ultrasonic cleaning equipment. Regarding piezoelectric cables.
〈従来技術〉
ポリ弗化ビニリデン、ポリ弗化ビニール、ポリ
塩化ビニリデン、ポリ塩化ビニール、ナイロン等
の圧電性有機物もしくは合成ゴムや合成樹脂の有
機物中にチタン酸ジルコニア酸鉛、チタン酸鉛等
の強誘電セラミツク粒子を混合してなる圧電性有
機セラミツク複合物は、一般の焼結質圧電磁器材
料に比し、その音響インピーダンスが水の音響イ
ンピーダンスに近似する特性を有し、このため、
これを圧電トランデユーサとして用いると水中を
伝播する音響波を効率良く受波し、感度を高め得
る利点を生じる。<Prior art> Piezoelectric organic materials such as polyvinylidene fluoride, polyvinyl fluoride, polyvinylidene chloride, polyvinyl chloride, and nylon, or strong organic materials such as lead zirconia titanate and lead titanate in the organic materials of synthetic rubber and synthetic resin. A piezoelectric organic ceramic composite formed by mixing dielectric ceramic particles has a characteristic that its acoustic impedance is close to that of water, compared to general sintered piezoelectric ceramic materials.
When this is used as a piezoelectric transducer, it has the advantage of efficiently receiving acoustic waves propagating in water and increasing sensitivity.
そこで第５図に示すように、前記圧電材料より
なる圧電層ａを電極芯ｂの周りに配置し、かつ該
圧電層ａの外周に導電塗料等の導電材ｃを配置
し、前記電極芯ｂと導電材ｃ間に所定の直流電圧
を印加して圧電層ａを径方向に分極した同軸状の
圧電ケーブルを形成し、これを水中に浸漬して、
前記電極芯ｂ及び導電材ｃ間から出力信号を取出
して前記水中を伝播する音響波を受信するように
した圧電ケーブルがある。 Therefore, as shown in FIG. 5, a piezoelectric layer a made of the piezoelectric material is arranged around the electrode core b, and a conductive material c such as a conductive paint is arranged around the outer periphery of the piezoelectric layer a. A coaxial piezoelectric cable is formed by applying a predetermined DC voltage between the conductive material c and the piezoelectric layer a in the radial direction, and immersing the cable in water.
There is a piezoelectric cable that receives an acoustic wave propagating in water by extracting an output signal from between the electrode core b and the conductive material c.
〈発明が解決しようとする問題点〉
ところで、前記構成による圧電ケーブルは、柔
軟であるため、音響波以外の圧力、例えば吹き流
し時の引張応力や水の流動、波立等による曲げ応
力が作用するが、これら機械的応力は圧電層ａの
長さ方向（分極軸に垂直な方向）に歪みを与え電
荷又は電圧を生じ、これがノイズ信号となつて音
響波に重畳的に加わり、Ｓ／Ｎ比を低下させると
いう欠点があつた。<Problems to be Solved by the Invention> By the way, since the piezoelectric cable having the above structure is flexible, pressure other than acoustic waves, such as tensile stress during windsocks, bending stress due to water flow, ripples, etc., acts on the piezoelectric cable. , these mechanical stresses cause a strain in the length direction of the piezoelectric layer a (perpendicular to the polarization axis) and generate a charge or voltage, which becomes a noise signal and is added to the acoustic wave in a superimposed manner, increasing the S/N ratio. It had the disadvantage of lowering the
本発明は、音響波以外の影響を阻止して前記従
来構成の欠点を除去し得る水中用圧電ケーブルの
提供を目的とするものである。 An object of the present invention is to provide an underwater piezoelectric cable that can eliminate the drawbacks of the conventional structure by blocking influences other than acoustic waves.
〈問題点を解決するための手段〉
本発明は、圧電性有機セラミツク複合物からな
る第一圧電層と第二圧電層をケーブルに沿つて設
け、前記いずれかの圧電層を、他方の圧電層に比
して水中での圧電定数の大きな圧電材料とすると
ともに、長さ方向に作用する応力により発生する
電荷又は電圧がほぼ相等しくなるよう構成し、か
つ前記第一圧電層と第二圧電層から生じる電荷又
は電圧の差異を取出す接続手段を備えてなるもの
である。<Means for Solving the Problems> The present invention provides a first piezoelectric layer and a second piezoelectric layer made of a piezoelectric organic ceramic composite along a cable, and connects one of the piezoelectric layers to the other piezoelectric layer. The first piezoelectric layer and the second piezoelectric layer are made of a piezoelectric material having a larger piezoelectric constant in water than that of It is provided with connection means for extracting the difference in charge or voltage arising from the connection.
〈作用〉
上記本発明におけるノイズキヤンセル原理は以
下の通りである。<Operation> The noise canceling principle in the present invention is as follows.
いま、一方の圧電層の水中での圧電定数を1dh
及び圧電定数をそれぞれ1d33，1d31とすると、これ
らの間には
1dh＝1d33＋21d31
の関係がある。 Now, the piezoelectric constant of one piezoelectric layer in water is 1 dh.
and piezoelectric constant are respectively 1 d 33 and 1 d 31 , there is a relationship between them as 1 dh= 1 d 33 +2 1 d 31 .
また、他方の圧電層についてもそれぞれ定数を
2dh，2d33，2d31とすると、これらの間には
2dh＝2d33＋22d31
の関係がある。 In addition, constants are also set for the other piezoelectric layer.
Assuming 2 dh, 2 d 33 and 2 d 31 , there is a relationship between them: 2 dh = 2 d 33 + 2 2 d 31 .
ところで、圧電定数1d33，2d33は径方向（分極軸
に平行な方向）の圧力に応答する電気変換率を示
し、音響波信号はこの定数に基づく電荷である。
また圧電定数1d31，2d31は長さ方向（分極軸に垂直
な方向）の圧力に応答する電気変換率を示しノイ
ズ信号はこの定数に基づく電荷である。 By the way, the piezoelectric constants 1 d 33 and 2 d 33 indicate the electrical conversion rate in response to pressure in the radial direction (direction parallel to the polarization axis), and the acoustic wave signal is a charge based on these constants.
Furthermore, the piezoelectric constants 1 d 31 and 2 d 31 indicate the electrical conversion rate in response to pressure in the length direction (direction perpendicular to the polarization axis), and the noise signal is a charge based on these constants.
従つてこれらの関係より
1dh−2dh≠０ …
1d31−2d31＝０ …
とすることによつて、1d33，2d33の差が取出され、
ノイズ信号が除去されて音響波による信号のみが
取出されるのである。 Therefore, from these relationships, by setting 1 dh- 2 dh≠0... 1 d 31 - 2 d 31 = 0..., the difference between 1 d 33 and 2 d 33 is extracted,
The noise signal is removed and only the acoustic wave signal is extracted.
そこで本発明では、一方の圧電層の材料に水中
での圧電定数1dhの大きい圧電性有機セラミツク
複合物、例えばチタン酸鉛（PbTiO3）にゴム、
樹脂等の有機物を混合したものを選択使用する。
ちなみにPbTiO3とシリコンゴムを７：10の比で
混合した材料は1dh＝35×10-12（Ｃ／Ｎ）である。 Therefore, in the present invention, one piezoelectric layer is made of a piezoelectric organic ceramic composite having a large piezoelectric constant of 1 dh in water, such as lead titanate (PbTiO 3 ) and rubber.
Select and use a mixture of organic substances such as resin.
By the way, a material made by mixing PbTiO 3 and silicone rubber at a ratio of 7:10 has 1 dh=35×10 -12 (C/N).
また他方の圧電層の材料に水中での圧電定数
2dhの小さい圧電複合材料、例えばジルコン酸・
チタン酸鉛（Pb（Zr・Ti）O3）にゴム、樹脂等
の有機物を混合したものを選択使用する。ちなみ
にPb（Zr・Ti）O3とシリコンゴムを７：10の比
で混合した材料は2dh＝８×10-12（Ｃ／Ｎ）であ
る。 In addition, the material of the other piezoelectric layer has a piezoelectric constant in water.
2 dh small piezoelectric composites, e.g. zirconate
Select and use a mixture of lead titanate (Pb(Zr・Ti)O 3 ) with organic substances such as rubber and resin. By the way, a material made by mixing Pb(Zr・Ti)O 3 and silicone rubber at a ratio of 7:10 has a ratio of 2 dh=8×10 -12 (C/N).
このように一方の圧電層を他方の圧電層に比し
水中での圧電定数の大きい圧電材料とすることで
上記関係式を満足することができる。一方、こ
れらの圧電材料は圧電定数1d31，2d31を異にし、水
中での圧電定数1dhの大きい材料ほど1d31が小さ
く、例えば上記特定の割合で配合したPbTiO3材
料の場合1d31＝−５×10-6（Ｃ／Ｎ）、同じくPb
（Ti・Zr）O3材料の場合2d31＝−25×10-6（Ｃ／
Ｎ）と異なる。そこで、本発明において上記関係
式を満足させるために、Pb（Ti・Zr）O3材料
に対し、圧電定数2d31がPbTiO3材料の1d31値に相
等しくするとか、分極電圧を下げて2d31の低下を
図ることが必要となる。 In this way, the above relational expression can be satisfied by making one piezoelectric layer a piezoelectric material having a larger piezoelectric constant in water than the other piezoelectric layer. On the other hand, these piezoelectric materials have different piezoelectric constants 1 d 31 and 2 d 31 , and the material with a larger piezoelectric constant 1 dh in water has a smaller 1 d 31. For example, in the case of the PbTiO 3 material blended in the above specific ratio 1 d 31 =-5×10 -6 (C/N), also Pb
For (Ti・Zr) O3 material, 2 d 31 = −25×10 -6 (C/
N) is different. Therefore, in order to satisfy the above relational expression in the present invention, the piezoelectric constant 2 d 31 of the Pb(Ti・Zr)O 3 material is made equal to the 1 d 31 value of the PbTiO 3 material, or the polarization voltage is lowered. Therefore, it is necessary to aim for a reduction of 2 d 31 .
尚、Pb（Ti・Zr）O3材料の2d31の低下は同時に
2dhも小さくなるため、PbTiO3材料の1dhとの差
が益々大きくなつて感度を最良にならしめる効果
もある。 In addition, the decrease in 2 d 31 of Pb(Ti・Zr)O 3 material is at the same time
Since 2 dh also becomes smaller, the difference from 1 dh of PbTiO 3 material becomes larger and larger, which has the effect of making the sensitivity optimal.
また上記は圧電層に発生する電荷Ｑに基づくノ
イズキヤンセル原理を説明したが、発生電圧Ｖに
よつてもＶ＝Ｑ／Ｃなる関係式から静電容量Ｃを
考慮するだけで、電荷Ｑが異なつても勿論、同様
に説明することができる。 In addition, although the noise canceling principle based on the charge Q generated in the piezoelectric layer has been explained above, the charge Q can also be changed depending on the generated voltage V by simply considering the capacitance C from the relational expression V=Q/C. Of course, the same explanation can be given.
本発明は、かかるノイズキヤンセル原理に基
き、圧電ケーブルが引つ張り又は屈撓により長さ
方向の応力を受けた場合に、該応力に基づいて第
二圧電層および第一圧電層に発生する電荷（又は
電圧）は夫々等しくかつ電気的減算により消滅す
る。このため、音響波が水中に発生すると、前記
接続手段から２つの圧電層の水中での圧電定数の
差に基づく電荷（又は電圧）のみの取出しが可能
となる。 The present invention is based on such a noise canceling principle, and when a piezoelectric cable receives longitudinal stress due to tension or bending, electric charges are generated in the second piezoelectric layer and the first piezoelectric layer based on the stress. (or voltage) are respectively equal and vanish by electrical subtraction. Therefore, when an acoustic wave is generated in water, only the charge (or voltage) based on the difference in the piezoelectric constants of the two piezoelectric layers in water can be taken out from the connecting means.
〈実施例〉
第１，２図は同軸型の圧電ケーブルに本発明を
適用した実施例に関する。<Embodiment> Figures 1 and 2 relate to an embodiment in which the present invention is applied to a coaxial type piezoelectric cable.
ここで２は圧電ゴム等からなる第一圧電層であ
つてその内側が正、外側が負となるように分極さ
れ、電極芯１がその中心を通つている。前記第一
圧電層２の周りには導電塗料等からなる接続電極
３が形成されており、さらにその外側には、内側
を正、外側を負に分極した圧電ゴム等からなる第
二圧電層５が設けられている。また前記第二圧電
層５の周面には導電塗料を塗着して形成した電極
６が設けられ、さらに導電性の網組７がその外周
に被着されている。 Here, reference numeral 2 denotes a first piezoelectric layer made of piezoelectric rubber or the like, which is polarized so that its inside is positive and its outside is negative, and the electrode core 1 passes through its center. A connection electrode 3 made of a conductive paint or the like is formed around the first piezoelectric layer 2, and a second piezoelectric layer 5 made of a piezoelectric rubber or the like with the inside polarized positively and the outside polarized negatively. is provided. Further, an electrode 6 formed by applying a conductive paint is provided on the circumferential surface of the second piezoelectric layer 5, and a conductive network 7 is further applied to the outer periphery of the electrode 6.
前記第一圧電層２と、第二圧電層５のうちのい
ずれか、例えば第二圧電層５を前記したように水
中での圧電定数の大きい、例えばチタン酸鉛
（PbTiO3）系材料により形成し、第一圧電層２
を通常のPb（Ti・Zr）O3系材料により形成する。 Either the first piezoelectric layer 2 or the second piezoelectric layer 5, for example, the second piezoelectric layer 5, is formed of a material having a large piezoelectric constant in water, such as lead titanate (PbTiO 3 ), as described above. and the first piezoelectric layer 2
is formed from ordinary Pb(Ti・Zr)O 3 based material.
而て形成された圧電ケーブルは、第一圧電層２
の正電極側と接続した電極芯１と、第二圧電層５
の負電極と接続した電極６及び網組７とをリード
線１０により電気的に接続して、その端部を出力
端子Ａとし、さらに第一圧電層２の負電極側と、
第二圧電層５の正電極側とに介装した接続電極３
をリード線１２により接続して、その端部を出力
端子Ｂとし、前記出力端子Ａ，Ｂ間より出力信号
を取出すようにしている。尚前記出力端子Ａはア
ース側となつている。 The thus formed piezoelectric cable has the first piezoelectric layer 2
The electrode core 1 connected to the positive electrode side of the second piezoelectric layer 5
The electrode 6 and the mesh 7 connected to the negative electrode of are electrically connected by a lead wire 10, the end thereof is used as an output terminal A, and further the negative electrode side of the first piezoelectric layer 2,
Connection electrode 3 interposed between the positive electrode side of the second piezoelectric layer 5
are connected by a lead wire 12, the end of which is used as an output terminal B, and an output signal is taken out between the output terminals A and B. Note that the output terminal A is on the ground side.
前記実施例の作用を説明すると、前記圧電ケー
ブルが波立等により長さ方向の応力が生じると、
前記第一圧電層２、第二圧電層５に夫々電荷（又
は電圧）が生じる。ところで、第一圧電層２、第
二圧電層５のd31はほぼ等しくしてあるから、前
記長さ方向の応力によつて両圧電層に発生する電
荷量（又は電圧）は、ほとんど同じであり、前記
したように第一圧電層２の正電極と、第二圧電層
５の負電極とはリード線１０により電気的に短絡
し、また第一圧電層２の負電極と第二圧電層５の
正電極とは接続電極３を介して短絡しているので
消極し合い、結局出力端子Ａ，Ｂ間には前記波立
等の外的応力によつては電位差（又は電圧差）が
生じない。一方、音響波による影響はケーブル全
外周から圧電層２，５に作用するが、第二圧電層
５は水中での圧電定数の大きな材料によつて形成
されているから、第一圧電層２よりも音響波に対
する感度が高い。このためその液中に音響波が発
生すると、前記感度差に対応する出力が出力端子
Ａ，Ｂ間に発生する。 To explain the operation of the above embodiment, when stress is generated in the longitudinal direction of the piezoelectric cable due to undulation or the like,
Charges (or voltages) are generated in the first piezoelectric layer 2 and the second piezoelectric layer 5, respectively. By the way, since d 31 of the first piezoelectric layer 2 and the second piezoelectric layer 5 are approximately equal, the amount of charge (or voltage) generated in both piezoelectric layers due to the stress in the longitudinal direction is almost the same. As described above, the positive electrode of the first piezoelectric layer 2 and the negative electrode of the second piezoelectric layer 5 are electrically short-circuited by the lead wire 10, and the negative electrode of the first piezoelectric layer 2 and the negative electrode of the second piezoelectric layer Since it is short-circuited with the positive electrode of No. 5 through the connecting electrode 3, they are mutually negative, and as a result, no potential difference (or voltage difference) is generated between the output terminals A and B due to external stress such as the ripples. . On the other hand, the influence of acoustic waves acts on the piezoelectric layers 2 and 5 from the entire outer circumference of the cable, but since the second piezoelectric layer 5 is made of a material with a large piezoelectric constant in water, it is stronger than the first piezoelectric layer 2. are also highly sensitive to acoustic waves. Therefore, when an acoustic wave is generated in the liquid, an output corresponding to the sensitivity difference is generated between the output terminals A and B.
従つて、前記したように波立等の外的応力によ
る電位の発生は消去されるから端子Ａ，Ｂ間には
音響波に対応する電気信号のみが抽出されるよう
になる。このため、前記湾曲による影響を受けな
いで、音響波のみを受信することができる。 Therefore, as described above, the generation of potential due to external stress such as ripples is eliminated, so that only the electrical signal corresponding to the acoustic wave is extracted between terminals A and B. Therefore, only acoustic waves can be received without being affected by the curvature.
尚、前記実施例において第一圧電層２を第二圧
電層５に比して水中での圧電定数の大きな材料に
よつて形成しても、音響波の影響は、その透過性
により内外の圧電層２，５に略等しく作用するか
ら、前記と同じ結果を得ることができる。 In the above embodiment, even if the first piezoelectric layer 2 is made of a material having a larger piezoelectric constant in water than the second piezoelectric layer 5, the influence of the acoustic waves will not affect the inner and outer piezoelectric layers due to its transparency. Since it acts approximately equally on layers 2 and 5, the same results as above can be obtained.
第３図は、第一圧電層２、第二圧電層５の分極
方向を逆とした実施例を示す。この場合には第一
圧電層２の外面と接触する電極４ａと、第二圧電
層５の内面と接触する電極４ｂとを絶縁層ｓによ
り絶縁し、第一圧電層２の正電極を第二圧電層５
の負電極と、第一圧電層２の負電極を第二圧電層
５の正電極と夫々電気的に接続する必要がある。
その他の作用効果は前記実施例と同じであり省略
する。 FIG. 3 shows an embodiment in which the polarization directions of the first piezoelectric layer 2 and the second piezoelectric layer 5 are reversed. In this case, the electrode 4a in contact with the outer surface of the first piezoelectric layer 2 and the electrode 4b in contact with the inner surface of the second piezoelectric layer 5 are insulated by an insulating layer s, and the positive electrode of the first piezoelectric layer 2 is Piezoelectric layer 5
It is necessary to electrically connect the negative electrode of the first piezoelectric layer 2 and the positive electrode of the second piezoelectric layer 5, respectively.
The other effects are the same as those of the previous embodiment, and will therefore be omitted.
第４図は、本発明を偏平な板状ケーブルに適用
したものである。 FIG. 4 shows the present invention applied to a flat plate cable.
すなわち第一圧電層２及び第二圧電層５を偏平
形状とし、電極板２０を介して重ね合わせ、その
外周を導電性被覆２１で覆つてなるものである。
この場合に前記第一圧電層２の内側を正、外側を
負の分極し、第二圧電層５の内側を負、外側を正
に分極し、前記電極板２０により第一圧電層２の
正電極と第二圧電層５の負電極を短絡し、導電性
被覆２１により第一圧電層２の負電極と第二圧電
層５の正電極を短絡する。而て、前記電極板２０
は出力端子Ａに接続され、導電性被覆２１は出力
端子Ｂに接続されて、該出力端子Ａ，Ｂ間から信
号が取出される。 That is, the first piezoelectric layer 2 and the second piezoelectric layer 5 have a flat shape, are stacked on top of each other with an electrode plate 20 in between, and the outer periphery thereof is covered with a conductive coating 21.
In this case, the inside of the first piezoelectric layer 2 is polarized positively and the outside is polarized negatively, the inside of the second piezoelectric layer 5 is polarized negatively and the outside is polarized, and the electrode plate 20 polarizes the first piezoelectric layer 2 to be positive. The electrode and the negative electrode of the second piezoelectric layer 5 are short-circuited, and the negative electrode of the first piezoelectric layer 2 and the positive electrode of the second piezoelectric layer 5 are short-circuited by the conductive coating 21 . Therefore, the electrode plate 20
is connected to output terminal A, conductive coating 21 is connected to output terminal B, and a signal is extracted from between output terminals A and B.
かかる偏平構造においても、同軸ケーブルにお
ける第３図の構成のように、第一圧電層２、第二
圧電層５の分極方向を同一とする構成にすること
は容易である。 Even in such a flat structure, it is easy to configure the polarization directions of the first piezoelectric layer 2 and the second piezoelectric layer 5 to be the same, as in the configuration of the coaxial cable shown in FIG. 3.
尚、前記各実施例に示す接続手段に換えて、一
方の圧電層から発生した電荷を反転し、他方の圧
電層から発生した電荷と結合し、その差を取出す
ようにしてもよい。 Incidentally, instead of the connection means shown in each of the embodiments described above, the electric charge generated from one piezoelectric layer may be inverted, combined with the electric charge generated from the other piezoelectric layer, and the difference between them may be extracted.
〈発明の効果〉
本発明は前記の説明によつて明らかにしたよう
に、圧電ケーブルが外圧により湾曲した場合に、
前記第一圧電層２および第二圧電層５に発生する
電荷を打消し合うようにし、水中での圧電定数の
大きな材料によつて形成された圧電層に生ずる前
記音響波に対応する電荷のみを出力端子から取出
し得るようにしたから、前記波立等の外的応力に
よる影響を可及的に除去して抽出でき、圧電ケー
ブルの出力のＳ／Ｎ比を著しく向上できる等の優
れた効果がある。<Effects of the Invention> As clarified by the above explanation, the present invention provides
The electric charges generated in the first piezoelectric layer 2 and the second piezoelectric layer 5 are canceled out, and only the electric charge corresponding to the acoustic wave generated in the piezoelectric layer formed of a material with a large piezoelectric constant in water is Since it can be taken out from the output terminal, the influence of external stress such as the ripples can be removed and extracted as much as possible, which has excellent effects such as significantly improving the S/N ratio of the output of the piezoelectric cable. .
第１図は本考案の第一実施例の斜視図、第２図
は同縦断側面図であり、第３図は第二実施例の縦
断側面図、第４図は第三実施例の縦断側面図、第
５図は従来装置の斜視図である。
１…中心電線、２…第一圧電層、５…第二圧電
層、Ａ，Ｂ…出力端子。
Fig. 1 is a perspective view of the first embodiment of the present invention, Fig. 2 is a longitudinal side view of the same, Fig. 3 is a longitudinal side view of the second embodiment, and Fig. 4 is a longitudinal side view of the third embodiment. FIG. 5 is a perspective view of a conventional device. DESCRIPTION OF SYMBOLS 1... Center electric wire, 2... First piezoelectric layer, 5... Second piezoelectric layer, A, B... Output terminal.
Claims (1)
電層と第二圧電層をケーブルに沿つて設け、前記
いずれかの圧電層を、他方の圧電層に比して水中
での圧電定数の大きな圧電材料とするとともに、
長さ方向に作用する応力により発生する電荷又は
電圧がほぼ相等しくなるよう構成し、かつ前記第
一圧電層と第二圧電層から生じる電荷又は電圧の
差異を取出す接続手段を備えたことを特徴とする
水中用圧電ケーブル。1 A first piezoelectric layer and a second piezoelectric layer made of a piezoelectric organic ceramic composite are provided along the cable, and one of the piezoelectric layers is made of a piezoelectric material having a larger piezoelectric constant in water than the other piezoelectric layer. In addition,
It is characterized in that it is configured so that charges or voltages generated by stress acting in the length direction are approximately equal, and that it is provided with a connecting means for extracting the difference in charges or voltages generated between the first piezoelectric layer and the second piezoelectric layer. Underwater piezoelectric cable.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59192318A JPS6171503A (en) | 1984-09-12 | 1984-09-12 | Underwater piezoelectric cable |
| US06/772,911 US4695988A (en) | 1984-09-12 | 1985-09-05 | Underwater piezoelectric arrangement |
| DE8585420164T DE3574554D1 (en) | 1984-09-12 | 1985-09-11 | PIEZOELECTRICAL UNDERWATER ARRANGEMENT. |
| EP85420164A EP0174897B1 (en) | 1984-09-12 | 1985-09-11 | Underwater piezoelectric arrangement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59192318A JPS6171503A (en) | 1984-09-12 | 1984-09-12 | Underwater piezoelectric cable |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6171503A JPS6171503A (en) | 1986-04-12 |
| JPH0436324B2 true JPH0436324B2 (en) | 1992-06-15 |
Family
ID=16289286
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59192318A Granted JPS6171503A (en) | 1984-09-12 | 1984-09-12 | Underwater piezoelectric cable |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6171503A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2747593B2 (en) * | 1988-12-19 | 1998-05-06 | 日本特殊陶業株式会社 | Piezoelectric cable for towing and its heating method |
-
1984
- 1984-09-12 JP JP59192318A patent/JPS6171503A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6171503A (en) | 1986-04-12 |
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