JPH06101879B2 - Aerial ultrasonic transducer - Google Patents
Aerial ultrasonic transducerInfo
- Publication number
- JPH06101879B2 JPH06101879B2 JP1421488A JP1421488A JPH06101879B2 JP H06101879 B2 JPH06101879 B2 JP H06101879B2 JP 1421488 A JP1421488 A JP 1421488A JP 1421488 A JP1421488 A JP 1421488A JP H06101879 B2 JPH06101879 B2 JP H06101879B2
- Authority
- JP
- Japan
- Prior art keywords
- matching layer
- acoustic matching
- piezoelectric element
- ultrasonic transducer
- case
- 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.)
- Expired - Fee Related
Links
- 229920005989 resin Polymers 0.000 claims description 11
- 239000011347 resin Substances 0.000 claims description 11
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- 229920001342 Bakelite® Polymers 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000004637 bakelite Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002040 relaxant effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
- G10K9/12—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated
- G10K9/122—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated using piezoelectric driving means
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
- G10K9/18—Details, e.g. bulbs, pumps, pistons, switches or casings
- G10K9/22—Mountings; Casings
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は空中超音波トランスジューサに関し、特にた
とえば円板状の音響整合層に円板あるいはリング状の圧
電素子が固着され、その圧電素子が樹脂ケースに封入さ
れている、空中超音波トランスジューサに関する。Description: TECHNICAL FIELD The present invention relates to an airborne ultrasonic transducer, and in particular, a disc-shaped or ring-shaped piezoelectric element is fixed to a disc-shaped acoustic matching layer, and the piezoelectric element is a resin. The present invention relates to an airborne ultrasonic transducer enclosed in a case.
〔従来技術〕 この種の空中超音波トランスジューサの一例が、たとえ
ば、昭和59年11月５日および昭和60年10月31日付でそれ
ぞれ出願公開された、実開昭59−164398号および実開昭
60−163899号公報などに開示されている。[Prior Art] An example of this type of aerial ultrasonic transducer is disclosed in, for example, No. 59-164398 and No. 164398, which were published on November 5, 1984 and October 31, 1985, respectively.
It is disclosed in Japanese Laid-Open Patent Publication No. 60-163899.
従来技術においては、熱膨張係数が極端に異なる圧電素
子と音響整合層とを接着ないし固着しているので、環境
温度が変化して、特に高温になると、熱応力によって圧
電素子が剥離したりクラックを生じたり、温度特性が悪
いという問題点があった。In the prior art, since the piezoelectric element having an extremely different thermal expansion coefficient and the acoustic matching layer are bonded or fixed to each other, when the environmental temperature changes, especially when the temperature becomes high, the piezoelectric element may be peeled or cracked due to thermal stress. However, there is a problem in that the temperature characteristic is poor.
それゆえに、この発明の主たる目的は、温度特性のよ
い、空中超音波トランスジューサを提供することであ
る。Therefore, a main object of the present invention is to provide an airborne ultrasonic transducer having good temperature characteristics.
この発明は、音響整合層と圧電素子との中間の熱膨張係
数を有する部材を、音響整合層および樹脂ケースの少な
くとも一方と一体的に設けた、空中超音波トランスジュ
ーサである。The present invention is an aerial ultrasonic transducer in which a member having a thermal expansion coefficient between the acoustic matching layer and the piezoelectric element is integrally provided with at least one of the acoustic matching layer and the resin case.
上述の部材によって音響整合層および／または樹脂ケー
スと圧電素子との熱膨張係数の極端な相違が緩和され
る。The above-mentioned members alleviate the extreme difference in thermal expansion coefficient between the acoustic matching layer and / or the resin case and the piezoelectric element.
この発明によれば、音響整合層および／または樹脂ケー
スとの熱膨張係数の差が緩和されるので、従来のものに
比べて、環境温度の変化による特性劣化が生じにくく、
したがってより高い温度、たとえば120〜150℃の高温環
境下でも十分使用できる。According to the present invention, the difference in thermal expansion coefficient between the acoustic matching layer and / or the resin case is reduced, so that characteristic deterioration due to changes in environmental temperature is less likely to occur as compared with the conventional one.
Therefore, it can be sufficiently used even at a higher temperature, for example, a high temperature environment of 120 to 150 ° C.
この発明の上述の目的，その他の目的，特徴および利点
は、図面を参照して行う以下の実施例の詳細な説明から
一層明らかとなろう。The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.
第１図はこの発明の一実施例を示す断面図解図である。
空中超音波トランスジューサ10は、この実施例では一体
的に樹脂成型された、音響整合層12およびケース14を含
む。しかしながら、この音響整合層12とケース14とは別
体のものとして構成されて、互いに接着されて一体化さ
れてもよいことは勿論である。FIG. 1 is a schematic sectional view showing an embodiment of the present invention.
The airborne ultrasonic transducer 10 includes an acoustic matching layer 12 and a case 14, which are integrally resin-molded in this embodiment. However, it is needless to say that the acoustic matching layer 12 and the case 14 may be configured as separate bodies and may be bonded and integrated with each other.
音響整合層12の内部には、所定の粒径たとえば10〜200
μｍを有するガラス製マイクロバルーン16が分散されて
いる。この音響整合層12の音響インピーダンスは、空気
中の音響インピーダンスと圧電素子18を音響インピーダ
ンスとの中間のものとなり、したがって両者の音響イン
ピーダンスを整合する作用を果たす。Inside the acoustic matching layer 12, a predetermined particle size, for example, 10 to 200
Dispersed are glass microballoons 16 with μm. The acoustic impedance of the acoustic matching layer 12 is intermediate between the acoustic impedance of the air and the acoustic impedance of the piezoelectric element 18, and therefore, the acoustic impedance of the two is matched.
音響整合層12の内面には、公知の円板状のあるいはリン
グ状の圧電素子18が接着される。この圧電素子18は、た
とえばPZTなどのセラミックユニットとその両主面上に
それぞれ形成された振動電極とを含み、その振動電極の
それぞれは、リード20によって端子板22に設けられた対
応の外部端子24に接続される。外部端子24によって圧電
素子18にトーンバースト波を印加すると圧電素子18から
所定の超音波信号が送波され、反射体から戻った超音波
が圧電素子18によって受波される。そして、その送受波
タイミングのずれ時間と音速とによって反射体までの距
離がわかる。A known disk-shaped or ring-shaped piezoelectric element 18 is adhered to the inner surface of the acoustic matching layer 12. This piezoelectric element 18 includes, for example, a ceramic unit such as PZT and vibrating electrodes respectively formed on both main surfaces thereof, and each vibrating electrode is provided with a corresponding external terminal provided on a terminal plate 22 by a lead 20. Connected to 24. When a tone burst wave is applied to the piezoelectric element 18 by the external terminal 24, a predetermined ultrasonic wave signal is transmitted from the piezoelectric element 18, and the ultrasonic wave returned from the reflector is received by the piezoelectric element 18. Then, the distance to the reflector can be known from the time difference between the transmission and reception timings and the sound velocity.
注目すべきは、音響整合層12とケース14とにまたがって
筒状体26が配置されている点である。この筒状体26は、
音響整合層12と圧電素子18との中間の熱膨張係数を有す
る材料、典型的には金属や樹脂で形成された円筒体であ
る。このような筒状体26は、予め型の中に位置決めされ
た後樹脂を型内に注入する樹脂モールディング技術によ
って、音響整合層12およびケース14と一体的に挿入され
得る。It should be noted that the tubular body 26 is arranged so as to straddle the acoustic matching layer 12 and the case 14. This tubular body 26 is
It is a cylindrical body formed of a material having a thermal expansion coefficient intermediate between that of the acoustic matching layer 12 and the piezoelectric element 18, typically a metal or a resin. Such a tubular body 26 can be integrally inserted with the acoustic matching layer 12 and the case 14 by a resin molding technique in which a resin is preliminarily positioned in the mold and then a resin is injected into the mold.
このようにして挿入された筒状体26の熱膨張係数によっ
て、音響整合層12およびケース14と圧電素子18との熱膨
張係数との間の熱膨張係数との差が緩和される。すなわ
ち、筒状体26は音響整合層12と圧電素子18との中間の熱
膨張係数を有するので、その筒状体26が音響整合層12お
よびケース14内に挿入ないし没入されていると、それら
一体物全体としての熱膨張係数は音響整合層12の固有の
熱膨張係数より小さくなり、圧電素子18の小さい熱膨張
係数により接近する。したがって、空中超音波トランス
ジューサ10が同じような高温環境下で使用されても、音
響整合層12全体の膨張率は従来のものに比べて小さく、
そのために熱応力による圧電素子18の剥離やクラックを
生じる可能性が少ない。したがって、従来のものに比べ
て、温度特性特に高温温度特性が大幅に改善され、従来
の金属ケースのものと同程度、たとえば120〜150℃程度
の高温環境下においても安定に動作する。Due to the thermal expansion coefficient of the tubular body 26 inserted in this way, the difference between the thermal expansion coefficients of the acoustic matching layer 12 and the case 14 and the thermal expansion coefficient of the piezoelectric element 18 is relaxed. That is, since the tubular body 26 has an intermediate thermal expansion coefficient between the acoustic matching layer 12 and the piezoelectric element 18, when the tubular body 26 is inserted or immersed in the acoustic matching layer 12 and the case 14, they are The coefficient of thermal expansion of the whole unit becomes smaller than the coefficient of thermal expansion specific to the acoustic matching layer 12, and comes closer to the small coefficient of thermal expansion of the piezoelectric element 18. Therefore, even if the aerial ultrasonic transducer 10 is used in a similar high temperature environment, the expansion coefficient of the acoustic matching layer 12 as a whole is smaller than that of the conventional one.
Therefore, the possibility of peeling or cracking of the piezoelectric element 18 due to thermal stress is low. Therefore, the temperature characteristic, especially the high temperature characteristic, is greatly improved as compared with the conventional one, and it operates stably even under the high temperature environment of about 120 to 150 ° C., which is similar to that of the conventional metal case.
第２図はこの発明の他の実施例を示す断面図解図であ
る。先の実施例では筒状体26が音響整合層12およびケー
ス14内に埋め込まれていたのに対し、この実施例では、
筒状体26はそれらに対して一体的に付着されている。詳
しく述べれば、筒状体26はケース14内の内壁面に接着剤
28によって接着ないし固着されている。このとき、筒状
体16は、好ましくは、ケース14のみならず音響整合層12
とも接触するように配置される。しかしながら、この実
施例においては、先の実施例においても同様であるが、
筒状体26は音響整合層12およびケース14の少なくとも一
方にのみ一体的に設けられて熱結合していればよく、必
ずしも両方に接触している必要はない。そして、第２図
実施例においても、第１図実施例と同じように、熱膨張
係数の差の緩和による温度特性の向上が期待できる。FIG. 2 is a schematic sectional view showing another embodiment of the present invention. While the tubular body 26 was embedded in the acoustic matching layer 12 and the case 14 in the previous embodiment, in this embodiment,
The tubular bodies 26 are integrally attached to them. More specifically, the tubular body 26 has an adhesive on the inner wall surface of the case 14.
It is adhered or fixed by 28. At this time, the tubular body 16 is preferably the acoustic matching layer 12 as well as the case 14.
It is placed so that it also contacts. However, in this embodiment, the same applies to the previous embodiment,
The tubular body 26 may be integrally provided only on at least one of the acoustic matching layer 12 and the case 14 so as to be thermally coupled, and it is not always necessary to be in contact with both. In the embodiment of FIG. 2 as well, similar to the embodiment of FIG. 1, it can be expected that the temperature characteristics are improved by relaxing the difference in the coefficient of thermal expansion.
なお、筒状体26の材料としては、金属であればアルミニ
ウム，銅，鉄などが、また樹脂であればベークライトな
どが利用可能である。As the material of the tubular body 26, aluminum, copper, iron or the like can be used if it is a metal, and bakelite or the like can be used if it is a resin.
第１図はこの発明の一実施例を示す断面図解図である。 第２図はこの発明の他の実施例を示す断面図解図であ
る。 図において、10は空中超音波トランスジューサ、12は音
響整合層、14はケース、18は圧電素子、22は端子板、26
は筒状体を示す。FIG. 1 is a schematic sectional view showing an embodiment of the present invention. FIG. 2 is a schematic sectional view showing another embodiment of the present invention. In the figure, 10 is an aerial ultrasonic transducer, 12 is an acoustic matching layer, 14 is a case, 18 is a piezoelectric element, 22 is a terminal plate, 26
Indicates a tubular body.
Claims (1)
音響整合層のその固着面と同一面側に樹脂ケースが形成
された空中超音波トランスジューサにおいて、 前記音響整合層と前記圧電素子との中間の熱膨張係数を
有する部材を前記音響整合層および前記樹脂ケースの少
なくとも一方と一体的に設けたことを特徴とする、空中
超音波トランスジューサ。1. A piezoelectric element is fixed to a plate-shaped acoustic matching layer,
In an aerial ultrasonic transducer in which a resin case is formed on the same side as the fixed surface of the acoustic matching layer, a member having a thermal expansion coefficient intermediate between the acoustic matching layer and the piezoelectric element is used as the acoustic matching layer and the resin. An airborne ultrasonic transducer, characterized by being provided integrally with at least one of the cases.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1421488A JPH06101879B2 (en) | 1988-01-25 | 1988-01-25 | Aerial ultrasonic transducer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1421488A JPH06101879B2 (en) | 1988-01-25 | 1988-01-25 | Aerial ultrasonic transducer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01190098A JPH01190098A (en) | 1989-07-31 |
| JPH06101879B2 true JPH06101879B2 (en) | 1994-12-12 |
Family
ID=11854841
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1421488A Expired - Fee Related JPH06101879B2 (en) | 1988-01-25 | 1988-01-25 | Aerial ultrasonic transducer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06101879B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001215143A (en) * | 2000-02-02 | 2001-08-10 | Ricoh Elemex Corp | Ultrasonic measuring apparatus |
| JP3944052B2 (en) * | 2001-12-27 | 2007-07-11 | 株式会社デンソー | Ultrasonic transducer and ultrasonic clearance sonar using the same |
| US6993967B2 (en) * | 2002-07-12 | 2006-02-07 | Ti Group Automotive Systems, L.L.C. | Fluid level sensor |
| DE112004001315T5 (en) * | 2003-07-16 | 2006-05-11 | Murata Mfg. Co., Ltd., Nagaokakyo | Ultrasonic transmitting and receiving device |
| DE10344741A1 (en) * | 2003-09-25 | 2005-04-14 | Endress + Hauser Gmbh + Co. Kg | Sound or ultrasonic transducer |
| DE102008055123B3 (en) * | 2008-12-23 | 2010-07-22 | Robert Bosch Gmbh | Ultrasonic transducer for use in a fluid medium |
| DE102008055126A1 (en) | 2008-12-23 | 2010-07-01 | Robert Bosch Gmbh | Ultrasonic transducer for use in a fluid medium |
| DE102014110163A1 (en) * | 2014-07-18 | 2016-01-21 | Endress + Hauser Gmbh + Co. Kg | Device for determining or monitoring a physical or chemical process variable of a medium |
-
1988
- 1988-01-25 JP JP1421488A patent/JPH06101879B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01190098A (en) | 1989-07-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |