DE4424194C1 - Ultrasonic transducer for measuring applications in gas or fluid environment - Google Patents
Ultrasonic transducer for measuring applications in gas or fluid environmentInfo
- Publication number
- DE4424194C1 DE4424194C1 DE19944424194 DE4424194A DE4424194C1 DE 4424194 C1 DE4424194 C1 DE 4424194C1 DE 19944424194 DE19944424194 DE 19944424194 DE 4424194 A DE4424194 A DE 4424194A DE 4424194 C1 DE4424194 C1 DE 4424194C1
- Authority
- DE
- Germany
- Prior art keywords
- housing
- ultrasonic transducer
- transducer according
- thickness
- damping body
- 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.)
- Revoked
Links
- 239000012530 fluid Substances 0.000 title 1
- 238000013016 damping Methods 0.000 claims abstract description 10
- 239000000463 material Substances 0.000 claims abstract description 8
- 239000000853 adhesive Substances 0.000 claims abstract description 3
- 230000001070 adhesive effect Effects 0.000 claims abstract description 3
- 229910000679 solder Inorganic materials 0.000 claims abstract 2
- 239000007788 liquid Substances 0.000 claims description 6
- 238000005259 measurement Methods 0.000 claims description 5
- 230000006978 adaptation Effects 0.000 claims description 2
- 239000000919 ceramic Substances 0.000 claims description 2
- 239000000945 filler Substances 0.000 claims description 2
- 239000004033 plastic Substances 0.000 claims description 2
- 229920003023 plastic Polymers 0.000 claims description 2
- -1 polytetrafluoroethylene Polymers 0.000 claims description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 2
- 230000009972 noncorrosive effect Effects 0.000 claims 1
- 230000008054 signal transmission Effects 0.000 claims 1
- 230000005540 biological transmission Effects 0.000 abstract 1
- 230000007797 corrosion Effects 0.000 abstract 1
- 238000005260 corrosion Methods 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 4
- 239000004814 polyurethane Substances 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 2
- 239000003822 epoxy resin Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 229920000647 polyepoxide Polymers 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- 238000002604 ultrasonography Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000004830 Super Glue Substances 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- FGBJXOREULPLGL-UHFFFAOYSA-N ethyl cyanoacrylate Chemical compound CCOC(=O)C(=C)C#N FGBJXOREULPLGL-UHFFFAOYSA-N 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000005340 laminated glass Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 238000004382 potting Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
-
- 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
- B06B1/0681—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 and a damping structure
Abstract
Description
Die Erfindung betrifft einen Ultraschallwandler für meßtechnische Zwecke in flüssigen und gasförmigen Medien.The invention relates to an ultrasonic transducer for measurement purposes in liquid and gaseous media.
Bekannte Ultraschallwandler weisen gemeinsam in einem Gehäuse eine Piezo keramik, einen Dämpfungskörper und eine akustische Anpassungsschicht auf (Wissensspeicher, Ultraschalltechnik, Fachbuchverlag Leipzig 1987).Known ultrasonic transducers have a piezo in a housing ceramic, a damping body and an acoustic adjustment layer (Knowledge storage, ultrasound technology, specialist book publisher Leipzig 1987).
Die Stärke der akustischen Anpassungsschicht beträgt üblicherweise Lambda- Viertel oder ein Vielfaches davon. Sie dient gleichzeitig als vordere Abdichtung des Gehäuses und besteht meist aus Kunststoff (EP-PS 0021534; DE-PS 25 37 788).The thickness of the acoustic adaptation layer is usually lambda Quarters or a multiple thereof. It also serves as the front one Sealing the housing and usually consists of plastic (EP-PS 0021534; DE-PS 25 37 788).
Für meßtechnische Zwecke in flüssigen und gasförmigen Medien sind Wandler anordnungen erforderlich, die bei höheren Frequenzen zur Erzeugung zeitlich begrenzter kurzer Impulse und für einen Dauerbetrieb geeignet sind. Bekannte Wandleranordnungen sind für bestimmte enge Anwendungen entweder als Luft schall-Wandler oder für kurzzeitigen Gebrauch im flüssigen Medien geeignet. Aus der DE-PS 30 12 038 C2 ist eine Anordnung für einen kurzzeitigen Unter wassergebrauch bekannt. In einem rohrförmigen Gehäuse, das mit einer kupfer kaschierten glasfaserverstärkten Epoxidharzfolie verschlossen ist, wird die Piezokeramik und eine Vergußmasse angeordnet. Die Anordnung arbeitet mit Frequenzen von 100 bis 500 KHz. Sie ist für meßtechnische Zwecke in unter schiedlichen Medien nicht geeignet, da die Schallschwingungen durch die kaschierte, verstärkte Epoxidharzfolie sowie konstruktiv bedingte Grenz schichten zu stark gedämpft werden und die Anordnung nicht langzeitstabil ist. Die US-PS 4 326 274 beschreibt einen Luftschallwandler in einem zweiteiligen rohrförmigen Gehäuse mit aufgesetzter zylindrischen Kappe, offenbar aus Thermoplast, die Piezokeramik und einen Dämpfungskörper enthält. Als Frontabdeckung ist ein dünner Schutzfilm aus Thermoplast angeordnet. Beide Gehäuseteile sind durch eine Klebschicht verbunden. Diese Anordnung ist nicht für meßtechnische Anwendungen bei höheren Temperaturen in beiden Medien durch das gewählte Material und unterschiedliche thermische Ausdehnungskoeffizienten sowie fugenbedingte Diffusionsvorgänge geeignet.There are transducers for measurement purposes in liquid and gaseous media arrangements required to temporally generate at higher frequencies limited short pulses and are suitable for continuous operation. Known Transducer assemblies are either air for certain narrow applications sound transducer or suitable for short-term use in liquid media. From DE-PS 30 12 038 C2 is an arrangement for a brief sub known water use. In a tubular housing that with a copper laminated glass fiber reinforced epoxy resin film is closed, the Piezoceramic and a potting compound arranged. The arrangement works with Frequencies from 100 to 500 KHz. It is in under for metrological purposes different media not suitable because the sound vibrations by the laminated, reinforced epoxy resin film and design-related limits layers are damped too much and the arrangement is not long-term stable. U.S. Patent 4,326,274 describes an airborne transducer in two parts tubular housing with attached cylindrical cap, apparently from Thermoplastic that contains piezoceramic and a damping body. As Front cover is arranged a thin protective film made of thermoplastic. Both Housing parts are connected by an adhesive layer. This arrangement is not for metrological applications at higher temperatures in both media the chosen material and different coefficients of thermal expansion as well as joint-related diffusion processes.
Der Erfindung liegt die Aufgabe zugrunde, einen thermostabilen und langzeit stabilen akustisch transparenten Ultraschallwandler im Frequenzbereich über 500 KHz zu entwickeln, der für meßtechnische Zwecke in flüssigen und gas förmigen Medien bis zu einer Temperatur von 130°C geeignet ist.The invention has for its object a thermostable and long-term stable acoustically transparent ultrasonic transducer in the frequency range above To develop 500 KHz for measurement purposes in liquid and gas shaped media up to a temperature of 130 ° C is suitable.
Erfindungsgemäß wird die Aufgabe wie im Patentanspruch 1 angegeben gelöst. Zweckmäßige Ausgestaltungen sind in den Unteransprüchen 2 bis 7 angegeben.According to the invention the object is achieved as indicated in claim 1. Appropriate configurations are specified in subclaims 2 to 7.
Der erfindungsgemäße Ultraschallwandler ist für meßtechnische Zwecke lang zeitstabil sowohl in gasförmigen als auch in flüssigen Medien bis zu Temperaturen von 130°C einsetzbar. Möglich ist auch der Einsatz in aggressiven Gasen. Überraschend war, daß entgegen der herrschenden Meinung ein einteiliges, vorn geschlossenes Gehäuse verwendet wird, dessen Bodenfläche, gleichzeitig Schallaustrittsfläche, weniger als Lambda-Viertel der Wellenlänge des Ge häusematerials dick und akustisch transparent ist. Durch die Befestigungs möglichkeit an der offenen Seite des Gehäuses wird die Schallabstahlungs richtung definiert und eine genaue Ausrichtung von Sender und Empfänger ge währleistet. Vorteilhaft wirkt sich weiter aus, daß durch das beschriebene Gehäuse unterschiedliche thermische Ausdehnungskoeffizienten verschiedener Gehäusematerialien und fugenbedingte Diffusionserscheinungen vermieden werden. Darüber hinaus ist auch die Herstellung des Wandlers kostengünstiger möglich als bei bekannten Anordnungen. Eine zusätzliche akustische Anpassungsschicht ist nicht erforderlich.The ultrasonic transducer according to the invention is long for measurement purposes time stable in both gaseous and liquid media up to Temperatures of 130 ° C can be used. Use in aggressive is also possible Gases. It was surprising that contrary to the prevailing opinion, a one-piece, front closed housing is used, the bottom surface, at the same time Sound exit area, less than lambda quarter of the wavelength of the Ge material is thick and acoustically transparent. Through the attachment Possibility on the open side of the housing is the sound radiation direction defined and a precise alignment of sender and receiver ensures. Another advantage is that the described Housing different coefficients of thermal expansion different Housing materials and joint-related diffusion phenomena can be avoided. In addition, the converter can also be manufactured more cheaply than in known arrangements. An additional acoustic adjustment layer not necessary.
Ein Ausführungsbeispiel der Erfindung wird unter Bezugnahme auf eine in der Zeichnung dargestellte Ausführungsform des Ultraschallwandlers beschrieben.An embodiment of the invention is described with reference to one in FIG Drawing shown embodiment of the ultrasonic transducer described.
Es zeigt Fig. 1 einen Schnitt durch eine Ausführungsform des Ultraschall wandlers.It shows Fig. 1 transducer is a section through an embodiment of the ultrasound.
In einem einteiligen vorn geschlossenen Gehäuse 3 in "Topfform" aus nicht rostendem Stahl sind eine Piezokeramik 1 und ein Dämpfungskörper 2 unter gebracht. Das Gehäuse weist an der offenen Seite eine Befestigungsmöglich keit 4 in Form eines Randes auf. Die Bodenfläche des Gehäuses, gleichzeitig Schallaustrittsfläche, ist plan, und ihre Dicke beträgt weniger als Lambda-Viertel der Wellenlänge des Gehäusematerials. Die Dicke der Wandung des Gehäuses und des Randes ist stärker als die Dicke der Bodenfläche. Die untere Fläche des Randes ist parallel der Ebene der Schallaustrittsfläche. Die Piezokeramik 1 ist ein piezoelektrischer Dickenschwinger und ist senkrecht zur akustischen Achse angeordnet. Sie weist vorn eine geschlossene elektrische Kontaktfläche 5,1 und an der Rückseite eine Kontaktstelle 5,2 für elektrische Zuleitungen 6 auf. Verbunden wird die Piezokeramik 1 mit dem Gehäuse 3 durch einen Cyanoacrylat-Klebstoff, wobei die Stärke der Klebfuge weniger als 15 µm beträgt. Die elektrischen Zuleitungen 7 sind mit Polytetrafluorethylen ummantelt. Auf der Rückseite und den Seitenflächen der Piezokeramik 1 wurde ein Dämpfungskörper 2 aus einem Polyurethansystem (WEVO PU 403/900 Mischungsverhältnis 100 : 14) so aufgegossen, daß eine geneigte Fläche entstand, dessen Winkel über 5 Grad beträgt. Die Mischung des PU-Systems erfolgte bei VPU-Systeme Luftfeuchtigkeit, um Luftbläschen im Dämpfungskörper zu erzeugen. Als Füllstoff wurde Wolframpulver einer Körnung unter 20 µ verwendet.A piezoceramic 1 and a damping body 2 are placed in a one-piece, front-closed housing 3 in a “pot shape” made of stainless steel. The housing has a fastening possibility 4 in the form of an edge on the open side. The bottom surface of the housing, which is also the sound exit surface, is flat and its thickness is less than lambda quarter of the wavelength of the housing material. The thickness of the wall of the housing and the edge is thicker than the thickness of the bottom surface. The lower surface of the edge is parallel to the plane of the sound exit surface. The piezoceramic 1 is a piezoelectric thickness transducer and is arranged perpendicular to the acoustic axis. It has a closed electrical contact surface 5.1 at the front and a contact point 5.2 for electrical feed lines 6 at the rear. The piezoceramic 1 is connected to the housing 3 by a cyanoacrylate adhesive, the thickness of the adhesive joint being less than 15 μm. The electrical leads 7 are coated with polytetrafluoroethylene. On the back and the side surfaces of the piezoceramic 1 , a damping body 2 made of a polyurethane system (WEVO PU 403/900 mixing ratio 100: 14) was poured in such a way that an inclined surface was created, the angle of which is over 5 degrees. In the case of VPU systems, the PU system was mixed with air humidity in order to generate air bubbles in the damping body. Tungsten powder with a grain size below 20 μ was used as filler.
Claims (7)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19944424194 DE4424194C1 (en) | 1994-07-08 | 1994-07-08 | Ultrasonic transducer for measuring applications in gas or fluid environment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19944424194 DE4424194C1 (en) | 1994-07-08 | 1994-07-08 | Ultrasonic transducer for measuring applications in gas or fluid environment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE4424194C1 true DE4424194C1 (en) | 1996-02-08 |
Family
ID=6522710
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE19944424194 Revoked DE4424194C1 (en) | 1994-07-08 | 1994-07-08 | Ultrasonic transducer for measuring applications in gas or fluid environment |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE4424194C1 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE29611678U1 (en) * | 1996-07-04 | 1997-08-07 | Siemens Ag | Sound transducers, in particular ultrasound transducers |
| DE19816456C1 (en) * | 1998-04-14 | 1999-06-17 | Trw Automotive Electron & Comp | Ultrasound sensor used in automobile |
| DE19927796C1 (en) * | 1999-06-18 | 2001-04-19 | Fraunhofer Ges Forschung | Damping material for ultrasonic waves |
| DE10045646A1 (en) * | 2000-09-15 | 2002-04-04 | Hydrometer Gmbh | Ultrasound converter for flow meter in liquid or gaseous medium, has electrodes at piezoelectric body defining overlapping area and contact points for electrodes are provided outside overlapping area |
| DE10133395A1 (en) * | 2001-07-13 | 2003-01-23 | Flowtec Ag | Ultrasonic flow meter sensor has heat conducting moulded mount |
| WO2013037616A1 (en) * | 2011-09-13 | 2013-03-21 | Endress+Hauser Flowtec Ag | Ultrasonic transducer of an ultrasonic flow meter |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4004266A (en) * | 1975-12-05 | 1977-01-18 | The United States Of America As Represented By The Secretary Of The Navy | Transducer array having low cross-coupling |
| DE2537788C3 (en) * | 1975-08-25 | 1980-04-10 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Ultrasonic transducer |
| US4326274A (en) * | 1979-07-04 | 1982-04-20 | Kabushiki Kaisha Morita Seisakusho | Transmission system of aerial ultrasonic pulse and ultrasonic transmitter and receiver used in the system |
| DE3012038C2 (en) * | 1980-03-28 | 1982-08-19 | Honeywell-Elac-Nautik Gmbh, 2300 Kiel | Electroacoustic water-borne sound converter |
| EP0021534B1 (en) * | 1979-06-25 | 1983-03-30 | Koninklijke Philips Electronics N.V. | Acoustic transducer |
| DE4215271A1 (en) * | 1992-05-09 | 1993-11-11 | Tridelta Ag | Ultrasonic transducer with piezoceramic element on ceramic diaphragm - has electrodes on opposite faces of ceramic block supplied from connection pins via soldered wire and internal metallisation of housing. |
-
1994
- 1994-07-08 DE DE19944424194 patent/DE4424194C1/en not_active Revoked
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2537788C3 (en) * | 1975-08-25 | 1980-04-10 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Ultrasonic transducer |
| US4004266A (en) * | 1975-12-05 | 1977-01-18 | The United States Of America As Represented By The Secretary Of The Navy | Transducer array having low cross-coupling |
| EP0021534B1 (en) * | 1979-06-25 | 1983-03-30 | Koninklijke Philips Electronics N.V. | Acoustic transducer |
| US4326274A (en) * | 1979-07-04 | 1982-04-20 | Kabushiki Kaisha Morita Seisakusho | Transmission system of aerial ultrasonic pulse and ultrasonic transmitter and receiver used in the system |
| DE3012038C2 (en) * | 1980-03-28 | 1982-08-19 | Honeywell-Elac-Nautik Gmbh, 2300 Kiel | Electroacoustic water-borne sound converter |
| DE4215271A1 (en) * | 1992-05-09 | 1993-11-11 | Tridelta Ag | Ultrasonic transducer with piezoceramic element on ceramic diaphragm - has electrodes on opposite faces of ceramic block supplied from connection pins via soldered wire and internal metallisation of housing. |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE29611678U1 (en) * | 1996-07-04 | 1997-08-07 | Siemens Ag | Sound transducers, in particular ultrasound transducers |
| DE19816456C1 (en) * | 1998-04-14 | 1999-06-17 | Trw Automotive Electron & Comp | Ultrasound sensor used in automobile |
| DE19927796C1 (en) * | 1999-06-18 | 2001-04-19 | Fraunhofer Ges Forschung | Damping material for ultrasonic waves |
| DE10045646A1 (en) * | 2000-09-15 | 2002-04-04 | Hydrometer Gmbh | Ultrasound converter for flow meter in liquid or gaseous medium, has electrodes at piezoelectric body defining overlapping area and contact points for electrodes are provided outside overlapping area |
| DE10045646C2 (en) * | 2000-09-15 | 2002-10-17 | Hydrometer Gmbh | Ultrasonic transducer and use of the same in an ultrasonic counter |
| DE10133395A1 (en) * | 2001-07-13 | 2003-01-23 | Flowtec Ag | Ultrasonic flow meter sensor has heat conducting moulded mount |
| WO2013037616A1 (en) * | 2011-09-13 | 2013-03-21 | Endress+Hauser Flowtec Ag | Ultrasonic transducer of an ultrasonic flow meter |
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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 | ||
| 8363 | Opposition against the patent | ||
| 8331 | Complete revocation |