DE4320549C1 - Ultrasonic transducer with impedance matching surface layer - Google Patents
Ultrasonic transducer with impedance matching surface layerInfo
- Publication number
- DE4320549C1 DE4320549C1 DE19934320549 DE4320549A DE4320549C1 DE 4320549 C1 DE4320549 C1 DE 4320549C1 DE 19934320549 DE19934320549 DE 19934320549 DE 4320549 A DE4320549 A DE 4320549A DE 4320549 C1 DE4320549 C1 DE 4320549C1
- Authority
- DE
- Germany
- Prior art keywords
- ultrasonic transducer
- layer
- impedance matching
- paint
- transducer according
- 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
- 239000002344 surface layer Substances 0.000 title 1
- 238000000034 method Methods 0.000 claims abstract description 4
- 238000004528 spin coating Methods 0.000 claims abstract description 4
- 229920002635 polyurethane Polymers 0.000 claims abstract description 3
- 239000004814 polyurethane Substances 0.000 claims abstract description 3
- 239000004922 lacquer Substances 0.000 claims abstract 4
- 239000010410 layer Substances 0.000 claims description 20
- 239000003973 paint Substances 0.000 claims description 11
- 239000011241 protective layer Substances 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 238000002604 ultrasonography Methods 0.000 claims description 2
- 239000002966 varnish Substances 0.000 claims 1
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 abstract description 9
- LFQCEHFDDXELDD-UHFFFAOYSA-N tetramethyl orthosilicate Chemical compound CO[Si](OC)(OC)OC LFQCEHFDDXELDD-UHFFFAOYSA-N 0.000 abstract description 4
- 239000000443 aerosol Substances 0.000 abstract 3
- 239000011253 protective coating Substances 0.000 abstract 2
- 239000011248 coating agent Substances 0.000 abstract 1
- 238000000576 coating method Methods 0.000 abstract 1
- 239000000203 mixture Substances 0.000 abstract 1
- 239000000463 material Substances 0.000 description 7
- BFXIKLCIZHOAAZ-UHFFFAOYSA-N methyltrimethoxysilane Chemical compound CO[Si](C)(OC)OC BFXIKLCIZHOAAZ-UHFFFAOYSA-N 0.000 description 3
- 239000004964 aerogel Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 2
- PCLIRWBVOVZTOK-UHFFFAOYSA-M 2-(1-methylpyrrolidin-1-ium-1-yl)ethyl 2-hydroxy-2,2-diphenylacetate;iodide Chemical compound [I-].C=1C=CC=CC=1C(O)(C=1C=CC=CC=1)C(=O)OCC[N+]1(C)CCCC1 PCLIRWBVOVZTOK-UHFFFAOYSA-M 0.000 description 1
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical class O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0644—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element
- B06B1/0662—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element with an electrode on the sensitive surface
- B06B1/067—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element with an electrode on the sensitive surface which is used as, or combined with, an impedance matching layer
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transducers For Ultrasonic Waves (AREA)
Abstract
Description
Die vorliegende Erfindung betrifft einen Ultraschallwandler, auf dessen Oberfläche eine poröse Aerogelschicht zur Impe danzanpassung angeordnet ist.The present invention relates to an ultrasonic transducer, on the surface of a porous airgel layer to Impe Danzanpassung is arranged.
Aus dem Aufsatz "Modified SiO2 aerogels as acoustic impedance matching layers in ultrasonic devices" von R. Gerlach, O. Kraus, J. Fricke, P.Ch. Eccardt, N. Kroemer und V. Magori in der Zeitschrift Journ. Non-Cryst. Solids 145 (1992) S. 227-232 ist es bekannt, Ultraschallwandler mit einer hochporösen Aero gelschicht zu versehen, um hierdurch die in Luft abgestrahlte Schalleistung erheblich zu erhöhen. Dieser Maßnahme liegt die Erkenntnis zugrunde, daß Aerogele eine sehr kleine akustische Impedanz im Bereich von los kg/m2s haben. Wird die Stärke der Aerogelschicht so bemessen, daß sie einer Viertel Wellenlänge der Ultraschallwellen entspricht, so kann die Aerogelschicht als sog. λ/4-Transformator wirken. Ein wesentlicher Nachteil eines solchen mit einer Aerogelschicht versehenen Ultraschall wandlers besteht jedoch darin, daß infolge der offenen Porosi tät dieser Schicht Fremdmaterialien, wie Öl, Staub oder Wasser in das Material eindiffundieren und die akustischen Eigenschaf ten nachteilig beeinflussen, im Extremfall das Material zerstö ren, können.From the article "Modified SiO2 aerogels as acoustic impedance matching layers in ultrasonic devices" by R. Gerlach, O. Kraus, J. Fricke, P.Ch. Eccardt, N. Kroemer and V. Magori in the journal Journ. Non-Cryst. Solids 145 (1992) pp 227-232, it is known to provide ultrasound transducer gelschicht with a highly porous Aero, thereby significantly increase the radiated sound power in air. This measure is based on the finding that aerogels have a very small acoustic impedance in the range of los kg / m 2 s. If the thickness of the airgel layer is dimensioned such that it corresponds to a quarter wavelength of the ultrasonic waves, the airgel layer can act as a so-called λ / 4 transformer. A major disadvantage of such an airgel provided with an ultrasonic transducer, however, is that due to the open Porosi ity of this layer foreign materials, such as oil, dust or water diffuse into the material and the acoustic properties th adversely affect, in extreme cases destroy the material ren, can.
Der vorliegenden Erfindung liegt die Aufgabe zugrunde, einen Ultraschallwandler anzugeben, mit hoher an ein gasförmiges Medium, insbesondere Luft, abgestrahlter Schalleistung, bei dem aber die Nachteile des Eindiffundierens von Fremdmate rialien verhindert ist. The present invention is based on the object, a Specify ultrasonic transducer with high to a gaseous Medium, especially air, radiated sound power, at but the disadvantages of Eindiffundens of Fremdmate is prevented.
Die Erfindung löst diese Aufgabe durch einen Ultraschallwandler mit den kennzeichnenden Merkmalen des vorliegenden Anspruchs 1. Bei der Herstellung der dünnen Schutzschicht ist besonders darauf zu achten, daß einerseits der gewünschte Schutz des Aerogelmaterials erreicht wird, andererseits die gewünschte Wirkung der Impedanzanpassung durch die Aerogelschicht erhalten bleibt.The invention solves this problem by an ultrasonic transducer with the characterizing features of present claim 1. In the production of the thin protective layer is special to ensure that, on the one hand, the desired protection of the Airgel material is achieved, on the other hand, the desired Effect of impedance matching obtained by the airgel layer remains.
Als besonders geeignete und zweckmäßige Maßnahme hat sich die Aufbringung einer dünnen Lackschicht erwiesen. Es gelingt auf diese Weise, eine Schicht herzustellen, die gegenüber äußeren Einflüssen unempfindlich ist und deren Schichtstärke so dünn bemessen werden kann, daß das Ultraschallfeld nicht nachhaltig beeinflußt wird.As a particularly suitable and appropriate measure, the Application of a thin coat of paint proved. It succeeds this way to make a layer that is opposite to outer Insensitive and their layer thickness is so thin can be measured that the ultrasonic field is not sustainable being affected.
Die notwendige geringe Schichtdicke kann insbesondere durch Anwendung der Spin-Coating-Technik erreicht werden. Hierbei wird die zu beschichtende Oberfläche in eine schnelle Rotation versetzt (ca. 2000 Umdrehungen/Minute). Der aufgebrachte Lack wird durch die entstehende Fliehkraft gleichmäßig über die Aerogeloberfläche ausgebreitet. Es bleibt eine Lackschicht mit Schichtdicken von ca. 10 bis 100 µm je nach Drehgeschwindigkeit und verwendetem Lack zurück. Je nach verwendetem Lacktyp kann die Oberfläche resistent gegenüber verschiedenen Umwelteinflüs sen gestaltet werden. Als geeignet hat sich z. B. ein Polyure thanlack erwiesen.The necessary small layer thickness can in particular by Application of the spin-coating technique can be achieved. in this connection becomes the surface to be coated in a fast rotation offset (about 2000 revolutions / minute). The applied paint is due to the centrifugal force evenly over the Airgel surface spread. There remains a coat of paint Layer thicknesses of approx. 10 to 100 μm depending on the speed of rotation and used paint back. Depending on the type of paint used the surface is resistant to various environmental influences be designed. As suitable has z. As a polyure thanlack proved.
Durch die Aufbringung der Schutzschicht wird die Resonanzfre quenz der darunterliegenden Aerogelschicht um etwa 10 kHz nach unten verschoben. Zum Ausgleich dieses Effektes muß vornherein die Dicke der Aerogelschicht auf entsprechend höhere Resonanz frequenz eingestellt werden.By applying the protective layer, the Resonanzfre frequency of the underlying airgel layer by about 10 kHz after moved down. To compensate for this effect must be in advance the thickness of the airgel layer to a correspondingly higher resonance frequency can be adjusted.
Im folgenden wird ein Ausführungsbeispiel der Erfindung anhand der Figur beschrieben. In the following an embodiment of the invention is based on the figure described.
Die Figur zeigt auf einer Halterung 1 ein Wandlersystem, beste hend aus einer zylinderförmigen Piezokeramikscheibe 3 aus Blei- Zirkonat-Titanat (PZT), z. B. "Vibrit 429" der Siemens AG mit einem Durchmesser von 16 mm und einer Stärke von 1 mm mit nicht dargestellten Elektroden zum Anlegen der Erregerspannung mit einer Frequenz im Bereich von etwa 100 bis 130 kH. Die Piezoke ramikscheibe liegt nicht unmittelbar auf der Halterung 1 auf, sondern unter Zwischenlage eines Silikonringes 2. Auf der Pie zokeramikscheibe 3 ist eine Aerogelschicht 4 aufgebracht, deren λ/4-Resonanz ca. 10 kHz über der Radialresonanz der Piezokera mik liegt und deren Stärke 0,51 mm beträgt. Die Aerogelschicht 4 wird auf der Piezokeramikplatte 3 in folgender Weise herge stellt:The figure shows on a holder 1, a transducer system, best starting from a cylindrical piezoceramic disc 3 made of lead zirconate titanate (PZT), z. B. "Vibrit 429" Siemens AG with a diameter of 16 mm and a thickness of 1 mm with electrodes, not shown for applying the excitation voltage with a frequency in the range of about 100 to 130 kH. The Piezoke ramikscheibe is not directly on the holder 1 , but with the interposition of a silicone ring. 2 On the Pie zokeramikscheibe 3 an airgel layer 4 is applied, whose λ / 4 resonance is about 10 kHz above the radial resonance of the piezoelectric koker mik and whose thickness is 0.51 mm. The airgel layer 4 is Herge on the piezoceramic plate 3 in the following manner:
Für ca. 100 ml Aerogel werden:For about 100 ml of airgel are:
benötigt.needed.
TMOS, MeTMOS und Methanol werden unter Rühren gemischt. Hernach wird die Ammoniaklösung zugegeben. Dann geliert das Material und wird ca. eine Woche gealtert. Nach der Alterung erfolgt die Trocknung in einem Autoklaven unter überkritischen Bedingungen. Von dem fertigen Material werden die gewünschten Aerogelplätt chen mit Hilfe einer Präzisionssäge heruntergesägt (alternativ ist auch die Gelierung des Materials in der späteren Verwendung angepaßten Formen denkbar). Die Plättchen werden nun unter Ver wendung eines Polyurethanklebers, dessen akustische Impedanz im Bereich der Impedanz der Piezokeramik liegt, auf die Keramik aufgeklebt.TMOS, MeTMOS and methanol are mixed with stirring. afterwards the ammonia solution is added. Then the material gels and is aged about a week. After aging, the Drying in an autoclave under supercritical conditions. From the finished material are the desired Aerogelplätt sawed down using a precision saw (alternatively is also the gelation of the material in the later use adapted forms conceivable). The tiles are now under Ver Use of a polyurethane adhesive whose acoustic impedance in Range of impedance of the piezoceramic is on the ceramic glued.
Auf der Oberfläche der Aerogelschicht 4 ist sodann im Spin- Coating-Verfahren eine Lackschicht aus einem Lack mit dem Han delsnamen ALKFIX der Fa. Graupner in einer Stärke von ca. 10 µm aufgebracht. Eine Messung des Frequenzgangs des Ultraschall schwingers nach Austrocknen des Lackes ergab, daß die Sendein tensität nicht abgenommen hatte und die Bandbreite nur gering fügig verringert wurde.On the surface of the airgel layer 4 is then applied in the spin coating process, a paint layer of a paint with the trade name ALKFIX the company. Graupner in a thickness of about 10 microns. A measurement of the frequency response of the ultrasonic vibrator after drying of the paint showed that the Sendein had not decreased intensity and the bandwidth was only marginally reduced.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19934320549 DE4320549C1 (en) | 1993-06-21 | 1993-06-21 | Ultrasonic transducer with impedance matching surface layer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19934320549 DE4320549C1 (en) | 1993-06-21 | 1993-06-21 | Ultrasonic transducer with impedance matching surface layer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE4320549C1 true DE4320549C1 (en) | 1994-07-14 |
Family
ID=6490842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE19934320549 Expired - Fee Related DE4320549C1 (en) | 1993-06-21 | 1993-06-21 | Ultrasonic transducer with impedance matching surface layer |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE4320549C1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7525237B2 (en) | 2004-08-25 | 2009-04-28 | Denso Corporation | Ultrasonic sensor |
| WO2012152870A1 (en) * | 2011-05-10 | 2012-11-15 | Basf Coatings Gmbh | Wheelsets for rail vehicles or parts of wheelsets for rail vehicles and method for coating |
-
1993
- 1993-06-21 DE DE19934320549 patent/DE4320549C1/en not_active Expired - Fee Related
Non-Patent Citations (1)
| Title |
|---|
| GERLACH, R. u.a.: Modified Si02 aerogels as acoustic impedance matching layers in ultra- sonic devices. In: Journ. Non-Cryst. Solids 145(1992), S. 227-232 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7525237B2 (en) | 2004-08-25 | 2009-04-28 | Denso Corporation | Ultrasonic sensor |
| DE102005040081B4 (en) * | 2004-08-25 | 2012-06-14 | Denso Corporation | ultrasonic sensor |
| WO2012152870A1 (en) * | 2011-05-10 | 2012-11-15 | Basf Coatings Gmbh | Wheelsets for rail vehicles or parts of wheelsets for rail vehicles and method for coating |
| CN103502299A (en) * | 2011-05-10 | 2014-01-08 | 巴斯夫涂料有限公司 | Wheelsets for rail vehicles or parts of wheelsets for rail vehicles and method for coating |
| US9016211B2 (en) | 2011-05-10 | 2015-04-28 | Basf Coatings Gmbh | Wheelsets for rail vehicles or parts of wheelsets for rail vehicles and method for coating |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 8100 | Publication of the examined application without publication of unexamined application | ||
| D1 | Grant (no unexamined application published) patent law 81 | ||
| 8364 | No opposition during term of opposition | ||
| 8339 | Ceased/non-payment of the annual fee |