JPS6126399A - Ultrasonic transmitter-receiver - Google Patents
Ultrasonic transmitter-receiverInfo
- Publication number
- JPS6126399A JPS6126399A JP14694284A JP14694284A JPS6126399A JP S6126399 A JPS6126399 A JP S6126399A JP 14694284 A JP14694284 A JP 14694284A JP 14694284 A JP14694284 A JP 14694284A JP S6126399 A JPS6126399 A JP S6126399A
- Authority
- JP
- Japan
- Prior art keywords
- annular
- piezoelectric element
- thin plate
- ultrasonic transducer
- ultrasonic
- 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
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
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/02—Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators
- G10K11/025—Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators horns for impedance matching
-
- 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
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/18—Methods or devices for transmitting, conducting or directing sound
- G10K11/26—Sound-focusing or directing, e.g. scanning
- G10K11/32—Sound-focusing or directing, e.g. scanning characterised by the shape of the source
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Piezo-Electric Transducers For Audible Bands (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、空中での超音波応用計測に必要な超音波送受
波器に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ultrasonic transducer necessary for ultrasonic applied measurement in the air.
（従来例の構成とその問題点）
空気中での超に波の送受波器は、圧電セラミクスの貼合
せ型圧電素子が多く用いられており、上記貼合せ型圧電
素子の撓み振動の共振点・***振点で使用するように作
られている。また、空気の機械的インピーダンスは、圧
電セラミクスのそれと比して著しく小さいため、貼合せ
型圧電素子を振動板と結合させて、機械的インピーダン
スの低下を図っている。(Conventional structure and its problems) For ultra-high wave transducers in the air, laminated piezoelectric elements made of piezoelectric ceramics are often used, and the resonance point of the bending vibration of the laminated piezoelectric element is - Made to be used at the anti-resonance point. Furthermore, since the mechanical impedance of air is significantly smaller than that of piezoelectric ceramics, the bonded piezoelectric element is coupled to the diaphragm to reduce the mechanical impedance.
従来の超音波送受波器の構造を第１図に示す。The structure of a conventional ultrasonic transducer is shown in FIG.
貼合せ型圧電素子１の中心部に結合軸２が貫通固定され
、結合軸２に振動板３が取付けられている。A coupling shaft 2 is fixed through the center of the bonded piezoelectric element 1, and a diaphragm 3 is attached to the coupling shaft 2.
そして、貼合せ型圧電素子１の振動の節部が支持台４の
先端に弾性接着剤５で支持されている。なお、６，６′
は端子、７は貼合せ型圧電素子１等を覆うケース、８は
ケース７の上部に形成された透孔に数句けられた保護用
メツソー、９．９′は貼合せ型圧電素子１と端子６．６
”ｅ電気的に接続しているリード線である。さらにケー
ス７は、放物面ホーン１０の喉部に挿着保持されている
Ｏ第２図は、上記構造の超音波送受波器の指向特性を示
したものである。ただし、駆動周波数４０ｋＨｚ 、ホ
ーン１０の直径が４２ｍｍのときの指向特性である。The vibration nodes of the bonded piezoelectric element 1 are supported by an elastic adhesive 5 at the tip of the support base 4. In addition, 6,6′
7 is a terminal, 7 is a case that covers the laminated piezoelectric element 1, etc., 8 is a protective hole formed in the upper part of the case 7, and 9.9' is the laminated piezoelectric element 1. Terminal 6.6
``e'' is a lead wire that is electrically connected. Furthermore, the case 7 is inserted and held in the throat of the parabolic horn 10. The directional characteristics are shown when the driving frequency is 40 kHz and the diameter of the horn 10 is 42 mm.
このとき、ピストン振動を行なう円形振動板の場合、音
圧半減角及び第１サイドローブの理論値は、それぞれ１
６４°及び−１７，６ｄＢ（メインローブに比して）で
、ｂｂ、この理論値近傍の値を示す超音波送受波器を実
現することは、極めて困難である。At this time, in the case of a circular diaphragm that performs piston vibration, the theoretical values of the sound pressure half angle and the first sidelobe are each 1
It is extremely difficult to realize an ultrasonic transducer that exhibits bb at 64° and −17.6 dB (compared to the main lobe), a value close to this theoretical value.
測定対象となる物体に対して分解能を上げようとすると
、さらに尖鋭な指向性が要求される。尖鋭な指向性は、
公知のように音源の大きさを増大させ、使用周波数を高
くすることにより実現される。しかし、使用層！皮敢を
高くすると音の減衰は著しく増大するとともに、貼合せ
型圧電素子を採用した超音波送受波器は感度が低下する
。したがって使用周波数を高くすることに限界があり、
音源を大きくせざ、るを得ない。Increasing the resolution of the object to be measured requires even sharper directivity. The sharp directivity is
As is well known, this can be achieved by increasing the size of the sound source and increasing the frequency used. But the usage layer! When the skin pressure is increased, the attenuation of sound increases significantly, and the sensitivity of the ultrasonic transducer using a bonded piezoelectric element decreases. Therefore, there is a limit to increasing the frequency used,
I have no choice but to make the sound source louder.
圧電セラミクスを用いた超音波送受波器に尖鋭な指向特
性を要求すると、振動板、貼合せ型圧電素子及び貼合せ
型圧電素子を支持する支持台等が著しく大きくなるとい
う欠点があった。When an ultrasonic transducer using piezoelectric ceramics is required to have sharp directivity characteristics, there is a drawback that the diaphragm, the bonded piezoelectric element, the support base for supporting the bonded piezoelectric element, etc. become significantly large.
また、ホーンを付加して指向特性を尖鋭にしようとする
場合、送受波感度を高くするために振動板を大きくする
と、尖鋭な指向特性を容易に実現することができないば
かりでなく、送受波感度を向上させることは困難であっ
た。Furthermore, when adding a horn to sharpen the directional characteristics, increasing the size of the diaphragm in order to increase the transmitting and receiving sensitivity not only makes it impossible to achieve sharp directional characteristics, but also increases the transmitting and receiving sensitivity. It was difficult to improve.
超音波による測距装置、特にカメラの自動焦点に用いる
場合、指向性が鋭くなると、カメラの撮１象レンズの光
軸と測距部が隔たるために・ぐララックスを生じるとい
う欠点があった。Ultrasonic distance measuring devices, especially when used for camera autofocus, have the disadvantage that when the directivity becomes sharp, the distance measuring section is separated from the optical axis of the camera's imaging lens, resulting in glare. .
また、円環状の振動子を用いて、細い超音波ビームを作
り方位分解能を向上する試みはすでに公知であるが、振
動子を円環状に作製する必要があり、加工が困難であっ
た。さらに、振動子の機械インピーダンスが空気中のそ
れと比して著しく大きく、その結果、音響エネルギーに
変換される度合は小さいという欠点があった。Furthermore, attempts to improve spatial resolution by creating a thin ultrasonic beam using an annular transducer have already been known, but the transducer had to be made in an annular shape and was difficult to process. Furthermore, the mechanical impedance of the vibrator is significantly larger than that in the air, and as a result, the degree of conversion into acoustic energy is low.
（発明の目的）
本発明は、円環状薄板と円環状圧電素子とを貼合せて、
尖鋭な指向特性かつ高送受波感度特性を有する超音波送
受波器を提供することを目的とする。(Object of the invention) The present invention is directed to bonding an annular thin plate and an annular piezoelectric element,
It is an object of the present invention to provide an ultrasonic transducer having sharp directivity characteristics and high wave transmission/reception sensitivity characteristics.
（発明の構成）
本発明は、上記の目的を実現するため、塀、下の構成を
有することを特徴とする。(Structure of the Invention) In order to achieve the above object, the present invention is characterized by having a structure of a wall and a bottom.
本発ｉの超音波送受波器は、円環状薄板と円環状圧電素
子を貼合せた構造を有し、その構潰体の撓み振動による
共振・***振周波数近傍の超音波信号を送波、受波する
ものである。The ultrasonic transducer of this invention has a structure in which an annular thin plate and an annular piezoelectric element are bonded together, and transmits ultrasonic signals near resonance and anti-resonance frequencies due to bending vibration of the collapsed structure. It is something that receives waves.
（実施例の説明）
本発明の一実施例について、図面を用いて説明する。第
３図は、この実施例の超音波送受波器の断面を示したも
のである。(Description of Embodiment) An embodiment of the present invention will be described with reference to the drawings. FIG. 3 shows a cross section of the ultrasonic transducer of this embodiment.
円環の中心を通過する法線を含む面での断面が、Ｕ字形
状を有する円環状薄板１３の内底部に円環状圧電素子１
１が貼付けられている。円環状圧電素子１１及び円環状
薄板１３から、リード線１９゜１９′によって電気的絶
縁物からなる端子板１４に設けられた端子１６及び１６
′に接続されている。円環状薄板１３の内側及び外側に
は、弾性コゝム２２等を介して放物面ホーン２０．２１
が設けられている。An annular piezoelectric element 1 is disposed at the inner bottom of an annular thin plate 13 whose cross section along a plane including a normal line passing through the center of the annular ring is U-shaped.
1 is attached. Terminals 16 and 16 are connected from the annular piezoelectric element 11 and the annular thin plate 13 to a terminal plate 14 made of an electrical insulator by lead wires 19°19'.
'It is connected to the. Parabolic horns 20 and 21 are connected to the inside and outside of the annular thin plate 13 via elastic combs 22 and the like.
is provided.
次に、上記横置による超音波送”・受波器の指向特性を
第４図に示す。図中、破線は円環状のピストン音源が示
す指向特性であシ、指向係数：Ｒ（θ）は次式で表わさ
れる。Next, Fig. 4 shows the directional characteristics of the ultrasonic transmitter and receiver when placed horizontally. In the figure, the broken line is the directional characteristic exhibited by the annular piston sound source, and the directional coefficient: R (θ) is expressed by the following equation.
ここで、Ｊｌは第１種ベッセル関数、ａ、ｂは円環状音
源の外半径、内半径、には波数、θは中心軸との角度で
ある。Here, Jl is a Bessel function of the first kind, a and b are the outer radius and inner radius of the annular sound source, the wave number is, and θ is the angle with the central axis.
本実施例の超音波送受波器は、第４図から円環状ピスト
ン音源の指向特性とほぼ同等の特性を示すことがわかる
。したがって、従来のものと比して、超音波放射面積が
等しい場合でも、狭指向性を示す。同時に、放射音圧レ
ベルも６ｄＢ程度増大したＯ
（発明の効果）
以上のように本発明の超音波送受波器は、尖鋭な指向特
性と高送受波感度特性を有し、音波を用７いた距離計等
、尖悦な指向特性が要求される超音波応用計測には極め
て有用なものである。It can be seen from FIG. 4 that the ultrasonic transducer of this embodiment exhibits characteristics almost equivalent to the directivity characteristics of the annular piston sound source. Therefore, compared to the conventional one, it exhibits narrow directivity even when the ultrasonic radiation area is equal. At the same time, the radiated sound pressure level also increased by about 6 dB. It is extremely useful for ultrasonic applied measurements that require sharp directional characteristics, such as distance meters.
第１図は、従来の超音波送受波器の一例を示す断面図、
第２図は、その指向特性を示す図であり、第３図は、本
発明の一実施例の断面図、第４図は、その指向特性を示
す図である。
１１・・円環状圧電素子、１３゛・・・円環状薄板、］
４・・・端子板、２（１，２トホーン。
第１図
第２図
−４（Ｊ −２００ｄＢFIG. 1 is a sectional view showing an example of a conventional ultrasonic transducer;
FIG. 2 is a diagram showing its directional characteristics, FIG. 3 is a sectional view of an embodiment of the present invention, and FIG. 4 is a diagram showing its directional characteristics. 11... Annular piezoelectric element, 13゛... Annular thin plate, ]
4...Terminal board, 2 (1, 2 horns. Figure 1 Figure 2-4 (J -200dB
Claims (3)
有し、その構造体の撓み振動を使用することを特徴とす
る超音波送受波器。(1) An ultrasonic transducer characterized in that it has a structure in which an annular thin plate and an annular piezoelectric element are bonded together, and uses bending vibration of the structure.
での断面がＵ字形形状であることを特徴とする特許請求
の範囲第（１）項記載の超音波送受波器。(2) The ultrasonic transducer according to claim (1), wherein the annular thin plate has a U-shaped cross section in a plane including a normal line passing through the center thereof.
いることを特徴とする特許請求の範囲第（１）項記載の
超音波送受波器。(3) The ultrasonic transducer according to claim (1), characterized in that horns are provided on the inside and outside of the annular thin plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14694284A JPS6126399A (en) | 1984-07-17 | 1984-07-17 | Ultrasonic transmitter-receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14694284A JPS6126399A (en) | 1984-07-17 | 1984-07-17 | Ultrasonic transmitter-receiver |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6126399A true JPS6126399A (en) | 1986-02-05 |
Family
ID=15419057
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14694284A Pending JPS6126399A (en) | 1984-07-17 | 1984-07-17 | Ultrasonic transmitter-receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6126399A (en) |
-
1984
- 1984-07-17 JP JP14694284A patent/JPS6126399A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4607186A (en) | Ultrasonic transducer with a piezoelectric element | |
| US5400788A (en) | Apparatus that generates acoustic signals at discrete multiple frequencies and that couples acoustic signals into a cladded-core acoustic waveguide | |
| US4228379A (en) | Diaphragm type piezoelectric electroacoustic transducer | |
| KR0152663B1 (en) | Imgae derived directional microphones | |
| US4044273A (en) | Ultrasonic transducer | |
| US4328569A (en) | Array shading for a broadband constant directivity transducer | |
| JPS5851697A (en) | Ultrasonic wave transceiver | |
| JPH078486A (en) | Ultrasonic transducer | |
| CA1136262A (en) | Electro-acoustic transducer with horn and reflector | |
| US4823327A (en) | Electroacoustic transducer | |
| JPS6126397A (en) | Ultrasonic transmitter-receiver | |
| JPH0242898A (en) | Ultrasonic oscillator | |
| US3253674A (en) | Ceramic microphone | |
| JPS6126399A (en) | Ultrasonic transmitter-receiver | |
| JPS6025956B2 (en) | Ultrasonic transducer | |
| JPS6126398A (en) | Ultrasonic transmitter-receiver | |
| JP2935551B2 (en) | Ultrasonic probe | |
| JPS642320B2 (en) | ||
| JPS6055798A (en) | Ultrasonic wave transmitting and receiving device | |
| JPS58124396A (en) | Ultrasonic wave transceiver | |
| JPS6133318B2 (en) | ||
| JPS58212300A (en) | Transceiver of ultrasonic wave | |
| JPS59175299A (en) | Ultrasonic wave transceiver | |
| JPH01270500A (en) | Ultrasonic element | |
| JPS58124398A (en) | Ultrasonic wave transceiver |