EP0757924A2 - Electroacoustic transducer - Google Patents

Electroacoustic transducer Download PDF

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Publication number
EP0757924A2
EP0757924A2 EP96112471A EP96112471A EP0757924A2 EP 0757924 A2 EP0757924 A2 EP 0757924A2 EP 96112471 A EP96112471 A EP 96112471A EP 96112471 A EP96112471 A EP 96112471A EP 0757924 A2 EP0757924 A2 EP 0757924A2
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EP
European Patent Office
Prior art keywords
ring body
ceramic plates
axial slots
transducer according
ring
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.)
Withdrawn
Application number
EP96112471A
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German (de)
French (fr)
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EP0757924A3 (en
Inventor
Egidius Dipl.-Ing. Arens
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Atlas Elektronik GmbH
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STN Atlas Elektronik GmbH
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Publication date
Application filed by STN Atlas Elektronik GmbH filed Critical STN Atlas Elektronik GmbH
Publication of EP0757924A2 publication Critical patent/EP0757924A2/en
Publication of EP0757924A3 publication Critical patent/EP0757924A3/en
Withdrawn legal-status Critical Current

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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B06GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06BMETHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/06Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
    • B06B1/0607Methods 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 multiple elements
    • B06B1/0622Methods 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 multiple elements on one surface
    • B06B1/0633Cylindrical array

Definitions

  • the invention relates to an electroacoustic transducer, in particular for underwater use, of the type defined in the preamble of claim 1.
  • the ring body has an oval cross section and carries the ceramic plates in recesses on the less strongly curved longitudinal sides of the ring oval, which are assembled to form two piezoelectric stacks, which in turn are in the ring oval are axially symmetrical.
  • the ceramic plates are glued together with metal electrodes so that the shape of the stack matches the arcuate curvature of the long sides.
  • the adjacent ceramic plates in the stack are oppositely polarized, and the electrodes are arranged between the ceramic plates so that the electrodes connected to the negative ceramic plates protrude on one end of the ring oval and the electrodes connected to the positive ceramic plates protrude on the other end of the ring oval.
  • the positive and negative electrodes are wired together.
  • the two piezoelectric stacks are held in the recesses of the ring oval by a jacket which consists of a plurality of circumferentially extending glass fibers which are embedded in epoxy resin. This jacket also produces the circumferential bias required for the ceramic plates.
  • the invention has for its object to provide a ring converter of the type mentioned, which has a good bandwidth, allows the emission of extremely long sound pulses and can be manufactured at a low cost.
  • the electroacoustic transducer according to the invention as a so-called ring transducer, has the essential advantage of being able to be manufactured at extremely low manufacturing costs.
  • the ring body which is preferably cut from an aluminum tube, has a customary cylindrical shape and not an expensive special shape like the known ring transducer. Milling the axial slots with parallel side walls into the ring body is easy and requires little manufacturing effort.
  • the ceramic plates have a rectangular shape, which, in contrast to other shapes, can be produced particularly inexpensively. The ceramic plates are held under prestress by the ring body itself, which prevents the ceramic plates from tearing even under extreme loads.
  • the prism-shaped material webs of the ring body remaining between the slots act as cooling vanes and thus allow extreme pulse lengths to be emitted.
  • the thickness of a pair of ceramic plates is dimensioned somewhat larger than the slot width of the axial slots in order to generate the prestress in the ring body acting on the ceramic plates.
  • the ring body is temporarily widened so that the slot width increases accordingly, so that the pair of ceramic plates can be inserted.
  • the ceramic plates of the ceramic plate pairs are preferably glued into the axial slots. After the adhesive has set, the expansion of the ring body is removed, so that the ceramic plates are now put under tension by the ring body, which contracts again. Now the electrodes are mounted on the ceramic plates, which is preferably done by gluing.
  • the ring body provided with the ceramic plates is enclosed on the outside by a protective jacket, which is preferably encapsulated and made of an acoustically transparent material, such as polyurethane or rubber.
  • This jacket only has a protective function against damage to the ceramic plates and the electrodes that are cast into the jacket.
  • the expansion of the ring body is achieved by a core coaxially pressed into it, the outer diameter of which is dimensioned somewhat larger than the inner diameter of the ring body.
  • a core coaxially pressed into it, the outer diameter of which is dimensioned somewhat larger than the inner diameter of the ring body.
  • the core can either be deep-frozen to such an extent that its outer diameter is slightly smaller than the inner diameter of the ring body, or can be provided with a cone so that it can be pressed into the ring body by axial pressure.
  • the core is removed from the ring body.
  • the electroacoustic transducer shown in side view in FIG. 1 and in cross section in FIG. 2, called a ring transducer due to its design, has an annular body 10 and a multiplicity of piezoelectric ceramic plates 11 held therein.
  • the ring body 10 is preferably made of an aluminum tube into which a plurality of axial slots 13 are milled, which are offset from one another by the same angular spacing.
  • the axial slots 13 end at a distance from the two end faces 101, 102 of the ring body 10 and penetrate the ring body 10 completely in the radial direction, so that the radial depth of the axial slots 13 is equal to the wall thickness of the ring body 10.
  • the slot walls 131 and 132 of the axial slots 13 run parallel to one another and to the radially aligned slot center plane 133 (FIG. 2).
  • the ceramic plates 11, 12 are inserted into the axial slots 13 in pairs, the ceramic plates 11 and the ceramic plates 12 being polarized in opposite directions to one another.
  • Fig. 2 is only the clearer graphical representation because of one of the axial slots 13 without ceramic plate pair 11, 12 reproduced. Basically, however, all axial slots 13 are covered with a pair of ceramic plates 11, 12.
  • the slot width of the axial slots 13 is dimensioned somewhat smaller than the thickness of a pair of ceramic plates 11, 12.
  • the ring body 10 temporarily widened so that the slot width is slightly larger than the thickness of the ceramic plate pairs 11, 12, so that the latter can be inserted into the axial slots 13.
  • This expansion of the ring body 10 takes place through a solid cylinder core, not shown here, whose outer diameter is somewhat larger than the inside diameter of the ring body 10 and which is inserted coaxially into the ring body 10.
  • the core can be deep-frozen so far before inserting it into the ring body 10 that its outer diameter is slightly smaller than the inner diameter of the ring body 10. When heated, the core expands and causes the desired expansion of the slot width in the axial slots 13.
  • the core can also be provided with an insertion cone, via which the core is pressed into the ring body 10 by axial pressure.
  • the ceramic plate pairs 11, 12 are now glued into the axial slots 13 with polarization directed towards one another.
  • the core is removed from the ring body 10, as a result of which the now contracting Ring body 10 presses the ceramic plates 11, 12 together in the axial slots 13.
  • the required electrodes are mounted on the ceramic plates 11, 12.
  • the thus assembled ring body 10 with ceramic plates 11, 12 inserted therein is provided on its inside and outside with a protective jacket 14 made of acoustically transparent material.
  • a protective jacket 14 made of acoustically transparent material.
  • polyurethane or rubber can be used as the material, the protective jacket 14 being produced by encapsulation.
  • the protective jacket 14 can also cover the two annular end faces 101 and 102 of the ring body 10.
  • the protective jacket 14 is designed as a rubber skin, it can also be provided with an oil filling.
  • the invention is not limited to the exemplary embodiment described. So the ring body does not necessarily have to be made of aluminum. Any good heat-conducting metal is suitable.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Transducers For Ultrasonic Waves (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)

Abstract

The transducer has a ring (10) supporting a number of piezoelectric ceramic plates (11, 12), positioned in oppositely polarised pairs fitted into equi-angularly spaced axial slits (13) formed in the ring. The axial slits end at a given spacing from each end face of the ring, with the piezoelectric ceramic plates pressed together by the parallel sidewalls of the slit. Pref. the ring is made of Al.

Description

Die Erfindung betrifft einen elektroakustischen Wandler, insbesondere für Unterwassereinsatz, der im Oberbegriff des Anspruchs 1 definierten Gattung.The invention relates to an electroacoustic transducer, in particular for underwater use, of the type defined in the preamble of claim 1.

Bei einem bekannten elektroakustischen Wandler dieser Art (US-PS 4 435 794) weist der Ringkörper einen ovalen Querschnitt auf und trägt in Ausnehmungen an den weniger stark gekrümmten Längsseiten des Ringovals die Keramikplatten, die zu zwei piezoelektrischen Stapeln zusammengesetzt sind, die ihrerseits im Ringoval einander achssymmetrisch gegenüberliegen. In jedem piezoelektrischen Stapel sind die Keramikplatten zusammen mit Metallelektroden so zusammengeklebt, daß die Form des Stapels der bogenförmigen Krümmung der Längsseiten angepaßt ist. Die im Stapel benachbarten Keramikplatten sind entgegengesetzt polarisiert, und die Elektroden sind zwischen den Keramikplatten so angeordnet, daß die an den negativen Keramikplatten angeschlossenen Elektroden auf der einen Stirnseite des Ringovals und die an den positiven Keramikplatten angeschlossenen Elektroden auf der anderen Stirnseite des Ringovals vorstehen. Jeweils die positiven und negativen Elektroden werden miteinander verdrahtet. Die beiden piezoelektrischen Stapel sind in den Ausnehmungen des Ringovals durch einen Mantel gehalten, der aus einer Vielzahl von in Umfangsrichtung verlaufenden Glasfasern besteht, die in Epoxidharz eingebettet sind. Dieser Mantel erzeugt zugleich die für die Keramikplatten erforderliche, in Umfangsrichtung gerichtete Vorspannung.In a known electroacoustic transducer of this type (US Pat. No. 4,435,794), the ring body has an oval cross section and carries the ceramic plates in recesses on the less strongly curved longitudinal sides of the ring oval, which are assembled to form two piezoelectric stacks, which in turn are in the ring oval are axially symmetrical. In each piezoelectric stack, the ceramic plates are glued together with metal electrodes so that the shape of the stack matches the arcuate curvature of the long sides. The adjacent ceramic plates in the stack are oppositely polarized, and the electrodes are arranged between the ceramic plates so that the electrodes connected to the negative ceramic plates protrude on one end of the ring oval and the electrodes connected to the positive ceramic plates protrude on the other end of the ring oval. The positive and negative electrodes are wired together. The two piezoelectric stacks are held in the recesses of the ring oval by a jacket which consists of a plurality of circumferentially extending glass fibers which are embedded in epoxy resin. This jacket also produces the circumferential bias required for the ceramic plates.

Der Erfindung liegt die Aufgabe zugrunde, einen Ringwandler der eingangs genannten Art zu schaffen, der eine gute Bandbreite aufweist, das Aussenden extrem langer Schallimpulse ermöglicht und zu einem niedrigen Gestehungspreis gefertigt werden kann.The invention has for its object to provide a ring converter of the type mentioned, which has a good bandwidth, allows the emission of extremely long sound pulses and can be manufactured at a low cost.

Die Aufgabe ist bei einem elektroakustischen Wandler der im Oberbegriff des Anspruchs 1 angegebenen Gattung erfindungsgemäß durch die Merkmale im Kennzeichenteil des Anspruchs 1 gelöst.The object is achieved according to the invention in an electroacoustic transducer of the type specified in the preamble of claim 1 by the features in the characterizing part of claim 1.

Der erfindungsgemäße elektroakustische Wandler, hat als sog. Ringwandler den wesentlichen Vorteil, zu äußerst geringen Fertigungskosten hergestellt werden zu können. Der bevorzugt aus einem Aluminiumrohr abgestochene Ringkörper hat eine übliche Zylinderform und keine teure Sonderform wie der bekannte Ringwandler. Das Einfräsen der Axialschlitze mit parallelen Seitenwänden in den Ringkörper ist proplemlos und mit geringem Fertigungsaufwand verbunden. Die Keramikplatten haben eine rechteckige Form, die im Gegensatz zu anderen Formgebungen besonders kostengünstig hergestellt werden kann. Die Keramikplatten werden von dem Ringkörper selbst unter Vorspannung gehalten, die ein zerreißen der Keramikplatten auch bei extremen Belastungen verhindert. Die zwischen den Schlitzen verbleibenden prismenförmigen Materialstege des Ringkörpers wirken als Kühlfahnen und erlauben damit das Aussenden extremer Impulslängen.The electroacoustic transducer according to the invention, as a so-called ring transducer, has the essential advantage of being able to be manufactured at extremely low manufacturing costs. The ring body, which is preferably cut from an aluminum tube, has a customary cylindrical shape and not an expensive special shape like the known ring transducer. Milling the axial slots with parallel side walls into the ring body is easy and requires little manufacturing effort. The ceramic plates have a rectangular shape, which, in contrast to other shapes, can be produced particularly inexpensively. The ceramic plates are held under prestress by the ring body itself, which prevents the ceramic plates from tearing even under extreme loads. The prism-shaped material webs of the ring body remaining between the slots act as cooling vanes and thus allow extreme pulse lengths to be emitted.

Vorteilhafte Ausführungsformen des erfindungsgemäßen elektroakustischen Wandlers mit vorteilhaften Ausgestaltungen und Weiterbildungen der Erfindung sind in den nachfolgenden Ansprüchen angegeben.Advantageous embodiments of the electroacoustic transducer according to the invention with advantageous refinements and developments of the invention are specified in the following claims.

Gemäß einer zweckmäßigen Ausführungsform der Erfindung wird zur Erzeugung der auf die Keramikplatten wirkenden Vorspannung im Ringkörper die Dicke eines Keramikplattenpaars etwas größer bemessen als die Schlitzbreite der Axialschlitze. Zum Einsetzen der Keramikplatten in die Axialschlitze wird der Ringkörper vorübergehend so aufgeweitet, daß sich die Schlitzbreite entsprechend vergrößert, so daß das Keramikplattenpaar eingefügt werden kann. Die Keramikplatten der Keramikplattenpaare werden dabei bevorzugt in die Axialschlitze eingeklebt. Nach Abbinden des Klebers wird die Aufweitung des Ringkörpers weggenommen, so daß nunmehr die Keramikplatten von dem sich wieder zusammenziehenden Ringkörper unter Spannung gesetzt werden. Nunmehr werden die Elektroden an die Keramikplatten montiert, was vorzugsweise durch Kleben erfolgt.According to an expedient embodiment of the invention, the thickness of a pair of ceramic plates is dimensioned somewhat larger than the slot width of the axial slots in order to generate the prestress in the ring body acting on the ceramic plates. To insert the ceramic plates into the axial slots, the ring body is temporarily widened so that the slot width increases accordingly, so that the pair of ceramic plates can be inserted. The ceramic plates of the ceramic plate pairs are preferably glued into the axial slots. After the adhesive has set, the expansion of the ring body is removed, so that the ceramic plates are now put under tension by the ring body, which contracts again. Now the electrodes are mounted on the ceramic plates, which is preferably done by gluing.

Gemäß einer bevorzugten Ausführungsform der Erfindung wird der mit den Keramikplatten versehene Ringkörper außen von einem Schutzmantel umschlossen, der vorzugsweise umgossen wird und aus einem akustisch transparenten Material, wie Polyurethan oder Gummi, besteht. Dieser Mantel hat ausschließlich Schutzfunktion gegen Beschädigung der Keramikplatten und der Elektroden, die in den Mantel mit eingegossen werden.According to a preferred embodiment of the invention, the ring body provided with the ceramic plates is enclosed on the outside by a protective jacket, which is preferably encapsulated and made of an acoustically transparent material, such as polyurethane or rubber. This jacket only has a protective function against damage to the ceramic plates and the electrodes that are cast into the jacket.

Gemäß einer vorteilhaften Ausführungsform der Erfindung wird die Aufweitung des Ringkörpers durch einen in diesen koaxial eingepreßten Kern erzielt, dessen Außendurchmesser etwas größer bemessen ist als der Innendurchmesser des Ringkörpers. Zum Einsetzen des Kerns kann dieser entweder so weit tiefgekühlt werden, daß sein Außendurchmesser geringfügig kleiner ist als der Innendurchmesser des Ringkörpers, oder mit einem Konus versehen werden, so daß er durch Axialdruck in den Ringkörper eingepreßt werden kann. Nach Einsetzen der Keramikplatten und Abbinden des Klebers wird der Kern wieder aus dem Ringkörper entfernt.According to an advantageous embodiment of the invention, the expansion of the ring body is achieved by a core coaxially pressed into it, the outer diameter of which is dimensioned somewhat larger than the inner diameter of the ring body. To insert the core, it can either be deep-frozen to such an extent that its outer diameter is slightly smaller than the inner diameter of the ring body, or can be provided with a cone so that it can be pressed into the ring body by axial pressure. After inserting the ceramic plates and setting the adhesive, the core is removed from the ring body.

Die Erfindung ist anhand eines in der Zeichnung dargestellten Ausführungsbeispiels im folgenden näher beschrieben. Es zeigen jeweils in schematischer Darstellung:

Fig. 1
eine Seitenansicht eines Ringwandlers,
Fig. 2
einen Schnitt längs der Linie II-II in Fig. 1.
The invention is described below with reference to an embodiment shown in the drawing. Each shows in a schematic representation:
Fig. 1
a side view of a ring converter,
Fig. 2
a section along the line II-II in Fig. 1st

Der in Fig. 1 in Seitenansicht und in Fig. 2 im Querschnitt dargestellte elektroakustische Wandler, aufgrund seiner Bauform Ringwandler genannt, weist einen Ringkörper 10 und eine Vielzahl von darin gehaltenen piezoelektrischen Keramikplatten 11 auf. Der Ringkörper 10 ist bevorzugt aus einem Aluminiumrohr gefertigt, in das eine Vielzahl von Axialschlitzen 13 eingefräst ist, die um gleiche Drehwinkelabstände zueinander versetzt sind. Die Axialschlitze 13 enden mit Abstand vor den beiden Stirnseiten 101, 102 des Ringkörpers 10 und durchdringen den Ringkörper 10 in Radialrichtung vollständig, so daß also die radiale Tiefe der Axialschlitze 13 gleich der Wanddicke des Ringkörpers 10 ist. Die Schlitzwände 131 und 132 der Axialschlitze 13 verlaufen parallel zueinander und zu der radial ausgerichteten Schlitzmittelebene 133 (Fig. 2).The electroacoustic transducer shown in side view in FIG. 1 and in cross section in FIG. 2, called a ring transducer due to its design, has an annular body 10 and a multiplicity of piezoelectric ceramic plates 11 held therein. The ring body 10 is preferably made of an aluminum tube into which a plurality of axial slots 13 are milled, which are offset from one another by the same angular spacing. The axial slots 13 end at a distance from the two end faces 101, 102 of the ring body 10 and penetrate the ring body 10 completely in the radial direction, so that the radial depth of the axial slots 13 is equal to the wall thickness of the ring body 10. The slot walls 131 and 132 of the axial slots 13 run parallel to one another and to the radially aligned slot center plane 133 (FIG. 2).

Die Keramikplatten 11, 12 sind paarweise in die Axialschlitze 13 eingesetzt, wobei die Keramikplatten 11 und die Keramikplatten 12 zueinander entgegengesetzt polarisiert sind. In Fig. 2 ist nur der übersichtlicheren zeichnerischen Darstellung wegen einer der Axialschlitze 13 ohne Keramikplattenpaar 11, 12 wiedergegeben. Grundsätzlich sind aber alle Axialschlitze 13 mit einem Keramikplattenpaar 11, 12 belegt. Zur Erzeugung einer in Umfangsrichtung auf die Keramikplattenpaare 11, 12 wirkenden Vorspannung im Ringkörper 10 ist die Schlitzbreite der Axialschlitze 13 etwas geringer bemessen als die Dicke eines Keramikplattenpaares 11, 12. Deswegen muß zum Einsetzen der Keramikplatten 11, 12 in die Axialschlitze 13 der Ringkörper 10 vorübergehend so aufgeweitet werden, daß die Schlitzbreite geringfügig größer ist als die Dicke der Keramikplattenpaare 11, 12, so daß letztere in die Axialschlitze 13 eingeschoben werden können. Diese Aufweitung des Ringkörpers 10 erfolgt durch einen hier nicht dargestellten Vollzylinderkern, dessen Außendurchmesser etwas größer ist als der lichte oder Innendurchmesser des Ringkörpers 10 und der koaxial in den Ringkörper 10 eingesetzt wird. Beispielsweise kann hierbei der Kern vor Einsetzen in den Ringkörper 10 so weit tiefgekühlt werden, daß sein Außendurchmesser geringfügig kleiner ist als der Innendurchmesser des Ringkörpers 10. Damit läßt sich der Kern im tiefgekühlten Zustand problemlos in den Ringkörper 10 einschieben. Mit Erwärmen dehnt sich der Kern aus und bewirkt die angestrebte Erweiterung der Schlitzbreite in den Axialschlitzen 13. Alternativ kann der Kern aber auch mit einem Einführkonus versehen sein, über welchen der Kern durch Axialdruck in den Ringkörper 10 eingepreßt wird.The ceramic plates 11, 12 are inserted into the axial slots 13 in pairs, the ceramic plates 11 and the ceramic plates 12 being polarized in opposite directions to one another. In Fig. 2 is only the clearer graphical representation because of one of the axial slots 13 without ceramic plate pair 11, 12 reproduced. Basically, however, all axial slots 13 are covered with a pair of ceramic plates 11, 12. In order to generate a prestress in the ring body 10 in the circumferential direction on the ceramic plate pairs 11, 12, the slot width of the axial slots 13 is dimensioned somewhat smaller than the thickness of a pair of ceramic plates 11, 12. Therefore, for inserting the ceramic plates 11, 12 into the axial slots 13, the ring body 10 temporarily widened so that the slot width is slightly larger than the thickness of the ceramic plate pairs 11, 12, so that the latter can be inserted into the axial slots 13. This expansion of the ring body 10 takes place through a solid cylinder core, not shown here, whose outer diameter is somewhat larger than the inside diameter of the ring body 10 and which is inserted coaxially into the ring body 10. For example, the core can be deep-frozen so far before inserting it into the ring body 10 that its outer diameter is slightly smaller than the inner diameter of the ring body 10. When heated, the core expands and causes the desired expansion of the slot width in the axial slots 13. Alternatively, the core can also be provided with an insertion cone, via which the core is pressed into the ring body 10 by axial pressure.

Bei im Ringkörper 10 eingesetztem Kern werden nunmehr die Keramikplattenpaare 11, 12 mit gegeneinander gerichteter Polarisierung in die Axialschlitze 13 eingeklebt. Nach Abbinden des Klebers wird der Kern aus dem Ringkörper 10 entfernt, wodurch der sich nunmehr zusammenziehende Ringkörper 10 die Keramikplatten 11, 12 in den Axialschlitzen 13 aneinanderpreßt. Jetzt werden die erforderlichen Elektroden an die Keramikplatten 11, 12 montiert. Der so fertig montierte Ringkörper 10 mit darin eingesetzten Keramikplatten 11, 12 wird auf seiner Innen- und Außenseite mit einem Schutzmantel 14 aus akustisch transparentem Material versehen. Als Material kann beispielsweise Polyurethan oder Gummi verwendet werden, wobei der Schutzmantel 14 durch Umgießen hergestellt wird. Der Schutzmantel 14 kann auch die beiden ringförmigen Stirnseiten 101 und 102 des Ringkörpers 10 überziehen. Bei der Ausführung des Schutzmantels 14 als Gummihaut kann diese noch mit einer Ölfüllung versehen werden.With the core inserted in the ring body 10, the ceramic plate pairs 11, 12 are now glued into the axial slots 13 with polarization directed towards one another. After the adhesive has set, the core is removed from the ring body 10, as a result of which the now contracting Ring body 10 presses the ceramic plates 11, 12 together in the axial slots 13. Now the required electrodes are mounted on the ceramic plates 11, 12. The thus assembled ring body 10 with ceramic plates 11, 12 inserted therein is provided on its inside and outside with a protective jacket 14 made of acoustically transparent material. For example, polyurethane or rubber can be used as the material, the protective jacket 14 being produced by encapsulation. The protective jacket 14 can also cover the two annular end faces 101 and 102 of the ring body 10. When the protective jacket 14 is designed as a rubber skin, it can also be provided with an oil filling.

Die Erfindung ist nicht auf das beschriebene Ausführungsbeispiel beschränkt. So muß der Ringkörper nicht notwendigerweise aus Aluminium hergestellt werden. Es eignet sich jedes gut wärmeleitende Metall.The invention is not limited to the exemplary embodiment described. So the ring body does not necessarily have to be made of aluminum. Any good heat-conducting metal is suitable.

Claims (9)

Elektroakustischer Wandler, insbesondere für Unterwassereinsatz, mit einem Ringkörper (10) und einer Vielzahl von darin gehaltenen piezoelektrischen Keramikplatten (11, 12), dadurch gekennzeichnet, daß der Ringkörper (10) eine Mehrzahl von um gleiche Drehwinkelabstände zueinander versetzte Axialschlitze (13) aufweist, die mit Abstand vor den beiden Stirnseiten (101, 102) des Ringkörpers (10) enden, und daß die Keramikplatten (11, 12) mit entgegengesetzter Polarisationsrichtung paarweise in den Axialschlitzen (13) einliegen und über die Schlitzwände (131, 132) durch den Ringkörper (10) aneinandergepreßt sind.Electroacoustic transducer, in particular for underwater use, with an annular body (10) and a multiplicity of piezoelectric ceramic plates (11, 12) held therein, characterized in that the annular body (10) has a plurality of axial slots (13) offset from one another by the same angular spacing, which end at a distance from the two end faces (101, 102) of the ring body (10), and that the ceramic plates (11, 12) lie in pairs in the opposite direction of polarization in the axial slots (13) and through the slot walls (131, 132) through the Ring body (10) are pressed together. Wandler nach Anspruch 1, dadurch gekennzeichnet, daß die Axialschlitze (13) jeweils den Ringkörper (10) radial vollständig durchdringen.Transducer according to claim 1, characterized in that the axial slots (13) each completely penetrate the ring body (10) radially. Wandler nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Schlitzwände (131, 132) der Axialschlitze (13) parallel zueinander und zu der radial ausgerichteten Schlitzmittelebene (133) verlaufen.Transducer according to Claim 1 or 2, characterized in that the slot walls (131, 132) of the axial slots (13) run parallel to one another and to the radially aligned slot center plane (133). Wandler nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß der Ringkörper (10) aus Aluminium besteht.Converter according to one of claims 1 to 3, characterized characterized in that the ring body (10) consists of aluminum. Wandler nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß der Ringkörper (10) mit eingesetzten Keramikplatten (11, 12) auf seiner Innen- und Außenseite mit einem akustisch transparenten Schutzmantel (14), z. B. aus Polyurethan oder Gummi, umschlossen, vorzugsweise umgossen, ist.Converter according to one of claims 1 to 4, characterized in that the ring body (10) with inserted ceramic plates (11, 12) on its inside and outside with an acoustically transparent protective jacket (14), for. B. of polyurethane or rubber, preferably encapsulated. Wandler nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß zur Erzeugung der auf die Keramikplatten (11, 12) wirkenden Preßspannung des Ringkörpers (10) die Schlitzbreite der Axialschlitze (13) etwas kleiner bemessen ist als die Dicke eines Keramikplattenpaars (11, 12) und daß der Ringkörper (10) zum Einsetzen der Keramikplatten (11, 12) in die Axialschlitze (13) vorübergehend so aufgeweitet wird, daß die Schlitzbreite sich entsprechend vergrößert.Transducer according to one of Claims 1 to 5, characterized in that the slot width of the axial slots (13) is dimensioned somewhat smaller than the thickness of a pair of ceramic plates (11, 12) to generate the compressive stress of the ring body (10) acting on the ceramic plates (11, 12). 12) and that the ring body (10) for inserting the ceramic plates (11, 12) in the axial slots (13) is temporarily expanded so that the slot width increases accordingly. Wandler nach Anspruch 6, dadurch gekennzeichnet, daß die Aufweitung des Ringkörpers (10) durch einen in diesen koaxial eingesetzen, vollzylindrischen Kern erzielt wird, dessen Außendurchmesser etwas größer bemessen ist als der Innendurchmesser des Ringkörpers (10).Transducer according to claim 6, characterized in that the expansion of the ring body (10) is achieved by a fully cylindrical core coaxially inserted therein, the outer diameter of which is dimensioned somewhat larger than the inner diameter of the ring body (10). Wandler nach Anspruch 7, dadurch gekennzeichnet, daß der Kern vor Einsetzen in den Ringkörper (10) so weit tiefgekühlt wird, daß sein Außendurchmesser geringfügig kleiner ist als der Innendurchmesser des Ringkörpers (10).Transducer according to claim 7, characterized in that the core is deep-frozen so far before insertion into the ring body (10) that its outer diameter is slightly smaller than the inner diameter of the ring body (10). Wandler nach Anspruch 7, dadurch gekennzeichnet, daß der Kern einen Konus zum Einführen in den Ringkörper (10) aufweist.Transducer according to claim 7, characterized in that the core has a cone for insertion into the ring body (10).
EP96112471A 1995-08-05 1996-08-02 Electroacoustic transducer Withdrawn EP0757924A3 (en)

Applications Claiming Priority (2)

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DE1995128881 DE19528881C1 (en) 1995-08-05 1995-08-05 Electroacoustic transducer for underwater applications
DE19528881 1995-08-05

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EP0757924A3 EP0757924A3 (en) 1999-06-30

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CN112954543A (en) * 2021-01-22 2021-06-11 哈尔滨工程大学 Double-end slotted piezoelectric circular ring underwater acoustic emission transducer

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DE19726442C1 (en) * 1997-06-23 1999-01-28 Stn Atlas Elektronik Gmbh Electroacoustic transducer
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DE102004038034A1 (en) * 2004-08-05 2006-02-23 Atlas Elektronik Gmbh Electroacoustic transmitting antenna
DE102011121006B4 (en) 2011-10-28 2015-08-13 Atlas Elektronik Gmbh Electroacoustic transducer
CN106782474B (en) * 2016-11-30 2020-06-16 哈尔滨工程大学 Deep sea broadband inlaying ring transducer

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CN112954543A (en) * 2021-01-22 2021-06-11 哈尔滨工程大学 Double-end slotted piezoelectric circular ring underwater acoustic emission transducer

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DE19528881C1 (en) 1996-06-27

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