EP1169143B1 - Impulse sound transducer with an elementary block made of piezoelectric material - Google Patents
Impulse sound transducer with an elementary block made of piezoelectric material Download PDFInfo
- Publication number
- EP1169143B1 EP1169143B1 EP00929375A EP00929375A EP1169143B1 EP 1169143 B1 EP1169143 B1 EP 1169143B1 EP 00929375 A EP00929375 A EP 00929375A EP 00929375 A EP00929375 A EP 00929375A EP 1169143 B1 EP1169143 B1 EP 1169143B1
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- Prior art keywords
- block
- elementary
- piezoelectric material
- electrode
- collar
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- 239000000463 material Substances 0.000 title claims abstract description 10
- 238000007493 shaping process Methods 0.000 claims 1
- 238000005516 engineering process Methods 0.000 abstract description 3
- 238000010276 construction Methods 0.000 description 6
- 230000005684 electric field Effects 0.000 description 6
- 230000010287 polarization Effects 0.000 description 6
- 238000013016 damping Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000002604 ultrasonography Methods 0.000 description 2
- 208000023514 Barrett esophagus Diseases 0.000 description 1
- 240000006829 Ficus sundaica Species 0.000 description 1
- 241000405217 Viola <butterfly> Species 0.000 description 1
- 230000006978 adaptation Effects 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
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000011295 pitch Substances 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 238000004154 testing of material Methods 0.000 description 1
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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
Definitions
- the invention relates to a pulse transducer in the ultrasonic range. Such converters are needed in many areas of technology where short pulses are necessary.
- the first priority is defectoscopy, which is what the Sonography in the medical field.
- Transducers also have relatively good pulse shapes and good repeatability lenticular elementary blocks, however, they produce only weak signals and are considerably less sensitive compared to classic converters. The same disadvantages have also been found on converters, which are caused by special Electrode design or inhomogeneous polarization of the piezo element capable are to deliver relatively short signals.
- the object underlying the invention is a sound transducer to create for the ultrasound range. that sends out strong and short impulses has a high sensitivity and repeatability of the parameters series production guaranteed.
- the object is achieved according to the invention the features of the pulse transducer contained in the characterizing part of claim 1 solved.
- the T-shaped block in longitudinal section, with the column, cone or pyramid shape round, oval or polygonal cross-section is dimensioned so that the shaft is damped and moves into the interior of the column in order to prevent it from reflecting on the free column wall and as an after-vibration comes out, which worsens the pulse quality. So it can further damping means are dispensed with.
- the manufacture as Bulk items due to the elimination of additional damping agents and adhesive connections much easier.
- the molding is essential for the invention of a covenant to the unit cell formation block.
- Figure 1 shows the unit cell 1 in a perspective view. This exists from block 2 and the collar 3 formed on it. The collar protrudes above the Block out.
- the unit cell 1 is in cross section Triangular shape, but it can also have any other shape. she can be round, oval or polygonal, and pointed towards the top as a cone or pyramid run.
- One electrode 4 is on the straight exit surface of the pulse arranged, while the other electrode 5 laterally along the block 2nd extends. It is not necessary for the electrode 5 to be around the whole block walks around and not that the bottom electrode covers the entire bottom surface covered.
- the thickness of the covenant is a, the height of the block is b, the width of the block marked with c and the total height of unit cell 1 with h.
- the active one The unit cell area is in the lower part of the block and inside of the federal government. As already mentioned, the proportions of the unit cell are important. It has been shown that the thickness of the federal government in relation to the Height of the block of piezoelectric material to the total height, i.e. a / b / h im Keep ratio 1 / 4-6 / 10 for best results. optimal Results means that strong and short impulses are sent out and the Transducers have a high sensitivity. In Figure 2 is that with the invention Sound transducer reached pulse curve shown
- the T-shape of unit cell 1 according to the invention is of very great importance, since it allows the electric field between the electrodes within the Unit cell is closed.
- the image of the electric field is in of the unit cell. As can be seen from this, this only runs within the converter's unit cell. This shape also enables volume oscillation and all up s.
- Fig. 1 directed waves, so against the impulse exit surface, propagating waves dampen so that they can no longer be reflected at the upper end of the unit cell.
- the proportions of the unit cell are of great importance.
- the ratio of the individual parts of the unit cell has already been specified Service.
- the height of the cell h should be at least 10 times greater than the height of the To be federal a.
- Such a converter produces Pulses that are 10 ns long and have a bandwidth of 4-35 as a receiver MHz.
- the ultrasonic wave that goes up in the drawing, totally subdued.
- the complete one Transducer does not have to be thicker than 2 mm. It is even possible to make it significant to make it thinner if the unit cell is designed to face up forms a peak which is sufficient for the wave going in this direction ahead of time attenuates.
- the component in the selected proportions of the electric field that go to the base of unit cell 1, i.e. the Crossbar of the T is parallel, comparable to the component perpendicular to it.
- the properties of the transducer according to the invention are only by Properties of the selected piezoelectric material and the precision of the Shape of the unit cell determined, d. H. in other words, the invention Transducers can be manufactured with very good repeatability.
- converter This type can contain one or more unit cells that are connected to each other can be connected.
- the converter according to the invention is capable of very short and very strong pulses to produce that cannot be achieved with other converter designs.
- the amplitude of the pulses produced is at least twice that of the classic converters. Its sensitivity is with the classic constructions comparable.
- the converter according to the invention can be used with considerably lower ones Produce costs and use them wherever classic types of converter can be used.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Piezo-Electric Transducers For Audible Bands (AREA)
- Surgical Instruments (AREA)
Abstract
Description
Die Erfindung bezieht sich auf einen Impulsschallwandler im Ultraschallbereich. Solche Wandler werden auf vielen Gebieten der Technik benötigt, wo kurze Impulse notwendig sind. An erster Stelle steht dabei die Defektoskopie, woran sich die Sonographie im medizinischen Bereich anschließt.The invention relates to a pulse transducer in the ultrasonic range. Such converters are needed in many areas of technology where short pulses are necessary. The first priority is defectoscopy, which is what the Sonography in the medical field.
Die klassische Konstruktion eines solchen Wandlers besteht aus einer planparallelen Platte aus piezoelektrischem Material, die an den beiden flachen Ober- und Unterseiten Elektroden aufweist, wobei die Platte senkrecht zu den mit Elektroden belegten Seiten polarisiert ist. Diese Platte ist auf einen Block aufgeklebt, der die Ultraschallwelle dampft und akustische Impedanz hat, die an die Piezoplatte angepaßt ist. An der Austrittsseite sind sogenannte Anpassungsschichten vorgesehen, die eine reflexionsfreie Schallübertragung und im Impulsbetrieb sehr kurze Impulse erzielen lassen. Wandler dieser Art gehören zum bekannten Stand der Technik, und eine gute Erörterung darüber und der dabei auftretenden Probleme finden sich z. B. in den Büchern von M. G. Silk, Ultrasonic Transducers for Nondestructive Testing, Adam Hilger 1984und J.und H. Krautkrämer, Werkstoffprüfung mit Ultraschall, Springer-Verlag 1986. Wandler der bekannten Bauart verlangen eine aufwendige und damit kostspielige Technologie, falls sie wirklich gute Impulse generieren sollen. Ferner sind die bekannten Wandler relativ dick (mindestens 5 mm) und es ist so gut wie unmöglich, sie für Frequenzen zu fertigen, die größer als 30 MHz sind. Auch werden bei Impulsanregung nur relativ lange Pulse erzeugt, die sich nachteilig auf die Messungen auswirken. Ein weiterer Nachteil besteht darin, dass sie sich nicht für automatische Massenfertigungen eignen und auch ihre Parameter nicht in einem engen Toleranzbereich gehalten werden können.The classic construction of such a converter consists of a plane-parallel one Plate made of piezoelectric material attached to the two flat top and Bottom electrodes has, the plate perpendicular to the electrodes occupied pages is polarized. This plate is glued to a block, which is the Ultrasonic wave vapors and has acoustic impedance that is matched to the piezo plate is. So-called adaptation layers are provided on the exit side, which is a reflection-free sound transmission and very short pulses in pulse mode let achieve. Converters of this type belong to the known prior art, and a good discussion about it and the problems that arise can be found e.g. B. in the books by M. G. Silk, Ultrasonic Transducers for Nondestructive Testing, Adam Hilger 1984 and J. and H. Krautkrämer, material testing with ultrasound, Springer-Verlag 1986. Transducers of the well-known type require a complex one and therefore expensive technology if they really generate good impulses should. Furthermore, the known transducers are relatively thick (at least 5 mm) and it is virtually impossible to manufacture them for frequencies greater than 30 MHz are. Even with pulse excitation, only relatively long pulses are generated adversely affect the measurements. Another disadvantage is that they are not suitable for automatic mass production and also their parameters cannot be kept within a narrow tolerance range.
Relativ gute Impulsformen und auch gute Wiederholbarkeit besitzen Wandler mit linsenförmigen Elementarblöcken, jedoch produzieren sie nur schwache Signale und sind im Vergleich zu den klassischen Wandlern erheblich weniger empfindlich. Die gleichen Nachteile wurden auch an Wandlern festgestellt, die durch spezielle Elektrodengestaltung oder inhomogene Polarisation des Piezoelements in der Lage sind, relativ kurze Signale zu liefern.Transducers also have relatively good pulse shapes and good repeatability lenticular elementary blocks, however, they produce only weak signals and are considerably less sensitive compared to classic converters. The same disadvantages have also been found on converters, which are caused by special Electrode design or inhomogeneous polarization of the piezo element capable are to deliver relatively short signals.
Die der Erfindung zugrunde liegende Aufgabe besteht darin, einen Schallwandler für den Ultraschallbereich zu schaffen. der starke und kurze Impulse aussendet, eine große Empfindlichkeit aufweist und eine Wiederholbarkeit der Parameter bei der Serienherstellung garantiert. Die gestellte Aufgabe wird erfindungsgemäß durch die im kennzeichnenden Teil des Anspruchs 1 enthaltenen Merkmale des Impulsschallwandlers gelöst.The object underlying the invention is a sound transducer to create for the ultrasound range. that sends out strong and short impulses has a high sensitivity and repeatability of the parameters series production guaranteed. The object is achieved according to the invention the features of the pulse transducer contained in the characterizing part of claim 1 solved.
Der im Längsschnitt T-förmige Block, der Säulen-, Kegel- oder Pyramidenform mit rundem, ovalem oder mehreckigem Querschnitt haben kann, ist so bemessen, dass eine Dämpfung der Welle erfolgt, die sich ins Innere der Säule bewegt, um zu verhindern, dass sie an der freien Säulenwand reflektiert und als eine Nachschwingung nach außen tritt, die die Impulsqualität verschlechtert. Es kann somit auf weitere Dämpfungsmittel verzichtet werden. Außerdem wird die Herstellung als Massenartikel durch den Wegfall von zusätzlichen Dämpfungsmitteln und Klebeverbindungen wesentlich erleichtert. Essentiell für die Erfindung ist die Anformung eines Bundes an den Block zur Bildung der Elementarzelle. Diese Formgebung, die gewählten Proportionen sowie die Anordnung der Elektroden, die an der Austrittsfläche und um den Block herum oberhalb des Bundes angeordnet sind, sind ausschlaggebend für die Grundschwingung, die dadurch dreidimensional gestaltet ist Es ist auch wichtig, dass infolge der erfindungsgemäßen Konstruktion der Elementarzelle sich das elektrische Feld innerhalb der Elementarzelle schließt und somit ein starker Impuls nach außen gesendet werden kann. Die Grundpolarisationsrichtung des Piezomaterials soll senkrecht zu der Fußfläche, also der Austrittsfläche des Impulses der T-förmigen Elementarzelle verlaufen.The T-shaped block in longitudinal section, with the column, cone or pyramid shape round, oval or polygonal cross-section is dimensioned so that the shaft is damped and moves into the interior of the column in order to prevent it from reflecting on the free column wall and as an after-vibration comes out, which worsens the pulse quality. So it can further damping means are dispensed with. In addition, the manufacture as Bulk items due to the elimination of additional damping agents and adhesive connections much easier. The molding is essential for the invention of a covenant to the unit cell formation block. This shape, the selected proportions as well as the arrangement of the electrodes on the exit surface and placed around the block above the federal government are crucial for the fundamental vibration, which is three-dimensional It is also important that due to the construction of the unit cell according to the invention the electric field within the unit cell closes and thus a strong impulse can be sent out. The basic polarization direction of the piezo material should be perpendicular to the base surface, i.e. the exit surface of the momentum of the T-shaped unit cell.
Es wurde festgestellt, dass es besonders vorteilhaft ist, wenn die folgenden Abmessungsverhältnisse eingehalten werden, nämlich a/b/h = 1 / 4-6 / 10, wobei a die Dicke des Bundes, b der Durchmesser des Blocks bzw. dessen Breite und h die Höhe der Elementarzelle ist. Die Größenverhältnisse der schallerzeugenden Elemente, hier der Elementarzelle, sind bei allen schallwellenerzeugenden Konstruktionen von ganz besonderer Bedeutung, wie Beispiele aus der Musikwelt zeigen. So erzeugen die Violine, die Bratsche, das Cello und der Kontrabaß aufgrund ihrer unterschiedlichen Größenverhältnisse unterschiedliche Tonhöhen und -tiefen.It has been found that it is particularly advantageous if the following dimensional ratios are observed, namely a / b / h = 1 / 4-6 / 10, where a is the Thickness of the collar, b the diameter of the block or its width and h the Unit cell height. The proportions of the sound generating elements, here the unit cell are in all sound wave generating constructions of particular importance, as examples from the music world show. So produce the violin, viola, cello and double bass due to their different Ratios of different pitches and depths.
Es hat sich ebenfalls gezeigt, dass eine zusätzliche radiale Polarisierung durch Anlegen einer hohen Spannung die Stärke des Impulses verbessert. Höchstwahrscheinlich wirkt sich diese Polarisierung durch die Ausnutzung der zusätzlichen Piezoeffekte vorteilhaft aus. It has also been shown that an additional radial polarization Applying a high voltage improves the strength of the pulse. most likely this polarization affects by taking advantage of the additional Piezo effects advantageous.
Weitere Einzelheiten der Erfindung werden anhand der beigefügten Zeichnungen erläutert. Dabei zeigen:
- Fig. 1
- eine perspektivische Darstellung der Elementarzelle,
- Fig. 2
- den Verlauf des Impulses,
- Fig. 3
- das elektrische Feld innerhalb der Elementarzelle.
- Fig. 1
- a perspective view of the unit cell,
- Fig. 2
- the course of the impulse,
- Fig. 3
- the electric field inside the unit cell.
Figur 1 zeigt die Elementarzelle 1 in perspektivischer Darstellung. Diese besteht
aus dem Block 2 und dem daran angeformten Bund 3. Der Bund ragt über den
Block heraus. In der gezeigten Darstellung ist die Elementarzelle 1 im Querschnitt
drei-eckförmig gehalten, sie kann aber auch jede andere Form besitzen. Sie kann
rund, oval oder mehreckig sein, sowie nach obenhin spitz als Kegel oder Pyramide
zulaufen. Die eine Elektrode 4 ist an der geraden Austrittsfläche des Impulses
angeordnet, während die andere Elektrode 5 sich seitlich entlang dem Block 2
erstreckt. Es ist nicht erforderlich, dass die Elektrode 5 um den ganzen Block
herumläuft und auch nicht, dass die untere Elektrode die gesamte untere Fläche
bedeckt.Figure 1 shows the unit cell 1 in a perspective view. This exists
from
Die Dicke des Bundes ist mit a, die Höhe des Blocks mit b, die Breite des Blocks mit c und die Gesamthöhe der Elementarzelle 1 mit h gekennzeichnet. Der aktive Bereich der Elementarzelle befindet sich im unteren Teil des Blocks und innerhalb des Bundes. Wie schon erwähnt, sind die Proportionen der Elementarzelle von Bedeutung. Es hat sich dabei gezeigt, dass die Dicke des Bundes im Verhältnis zu der Höhe des Blocks aus piezoelektrischem Material zu der Gesamthöhe, also a/b/h im Verhältnis 1 / 4-6 / 10 zu halten ist, um optimale Ergebnisse zu erzeugen. Optimale Ergebnisse heißt, dass starke und kurze Impulse ausgesendet werden und die Wandler eine große Empfindlichkeit aufweisen. In Figur 2 ist die mit dem erfindungsgemäßen Schallwandler erreichte Impulskurve dargestellt The thickness of the covenant is a, the height of the block is b, the width of the block marked with c and the total height of unit cell 1 with h. The active one The unit cell area is in the lower part of the block and inside of the federal government. As already mentioned, the proportions of the unit cell are important. It has been shown that the thickness of the federal government in relation to the Height of the block of piezoelectric material to the total height, i.e. a / b / h im Keep ratio 1 / 4-6 / 10 for best results. optimal Results means that strong and short impulses are sent out and the Transducers have a high sensitivity. In Figure 2 is that with the invention Sound transducer reached pulse curve shown
Die erfindungsgemäße T-Form der Elementarzelle 1 ist von sehr großer Bedeutung, da sie ermöglicht, dass das elektrische Feld zwischen den Elektroden innerhalb der Elementarzelle geschlossen wird. In Figur 3 ist das Bild des elektrischen Feldes in der Elementarzelle wiedergegeben. Wie daraus ersichtlich, verläuft dieses nur innerhalb der Elementarzelle des Wandlers. Diese Form ermöglicht außerdem eine Volumenschwingung und dazu noch alle nach oben s. Fig. 1 gerichteten Wellen, also entgegen der Impulsaustrittsfläche sich fortpflanzenden Wellen so dämpft, dass sie nicht mehr an dem oberen Ende der Elementarzelle reflektiert werden können.The T-shape of unit cell 1 according to the invention is of very great importance, since it allows the electric field between the electrodes within the Unit cell is closed. In Figure 3 the image of the electric field is in of the unit cell. As can be seen from this, this only runs within the converter's unit cell. This shape also enables volume oscillation and all up s. Fig. 1 directed waves, so against the impulse exit surface, propagating waves dampen so that they can no longer be reflected at the upper end of the unit cell.
Von großer Bedeutung sind - wie schon ausgeführt - die Proportionen der Elementarzelle. Das Verhältnis der einzelnen Teile der Elementarzelle ist bereits angegeben worden. Die Höhe der Zelle h soll mindestens 10 mal größer als die der Höhe des Bundes a sein. Die tatsächlichen Abmessungen können beispielsweise folgende Werte haben: a = 0,2 mm, b = 1 mm und h = 2 mm. Ein solcher Wandler produziert Impulse, die 10 ns lang sind und hat als Empfänger eine Bandbreite von 4 -35 MHz.As already mentioned, the proportions of the unit cell are of great importance. The ratio of the individual parts of the unit cell has already been specified Service. The height of the cell h should be at least 10 times greater than the height of the To be federal a. The actual dimensions can be, for example, the following Values have: a = 0.2 mm, b = 1 mm and h = 2 mm. Such a converter produces Pulses that are 10 ns long and have a bandwidth of 4-35 as a receiver MHz.
Bei dem erfindungsgemäßen Wandler mit den genannten Proportionen wird die Ultraschallwelle, die in der Zeichnung noch oben geht, total gedämpft. Der komplette Wandler muß nicht dicker als 2 mm sein. Es ist sogar möglich, ihn bedeutend dünner zu machen, wenn die Elementarzelle so konstruiert ist, dass sie nach oben eine Spitze bildet, die die in diese Richtung gehende Welle vorzeitig ausreichend dämpft.In the transducer according to the invention with the proportions mentioned, the ultrasonic wave, that goes up in the drawing, totally subdued. The complete one Transducer does not have to be thicker than 2 mm. It is even possible to make it significant to make it thinner if the unit cell is designed to face up forms a peak which is sufficient for the wave going in this direction ahead of time attenuates.
Von Bedeutung ist es auch, dass bei den gewählten Größenverhältnissen die Komponente des elektrischen Feldes, die zu dem Fuß der Elementarzelle 1, also den Querbalken des T parallel, vergleichbar mit der dazu senkrechten Komponente ist. It is also important that the component in the selected proportions of the electric field that go to the base of unit cell 1, i.e. the Crossbar of the T is parallel, comparable to the component perpendicular to it.
Infolge dieser Tatsache spielen alle Piezokoeffizienten des Piezomaterials eine im wesentlichen gleichbedeutende Rolle. Es kommt zu einer Volumenschwingung des aktiven Bereichs der Elementarzelle, die durch ihre Form und gezielte Anbringung der Elektroden sowie nachträgliche Polarisierung in der radialen Richtung gestalbar ist. Die nachträgliche Polarisierung erfolgt nach Fertigstellung des Wandlers bzw. der Elementarzelle durch Anlegen einer relativ hohen Spannung an seine Elektroden. Diese Schwingungsart ermöglich offensichtlich eine bessere Nutzung des Piezoeffektes und beeinflusst auch die Dämpfung der nach hinten gehenden Welle.As a result of this fact, all the piezo coefficients of the piezo material essentially play one equivalent role. The volume of the active area of the unit cell due to its shape and targeted attachment of the electrodes and subsequent polarization in the radial direction is. The subsequent polarization takes place after completion of the converter or the unit cell by applying a relatively high voltage to its electrodes. This type of vibration obviously enables better use of the Piezo effect and also affects the damping of the shaft going backwards.
Die Eigenschaften des erfindungsgemäßen Wandlers werden dabei nur durch die Eigenschaften des gewählten piezoelektrischen Materials und die Präzision der Formgebung der Elementarzelle bestimmt, d. h. mit anderen Worten, der erfindungsgemäße Wandler lässt sich mit sehr guter Wiederholbarkeit herstellen. Wandler diesen Typs können eine oder mehrere Elementarzellen enthalten, die miteinander verbunden werden können.The properties of the transducer according to the invention are only by Properties of the selected piezoelectric material and the precision of the Shape of the unit cell determined, d. H. in other words, the invention Transducers can be manufactured with very good repeatability. converter This type can contain one or more unit cells that are connected to each other can be connected.
Der erfindungsgemäße Wandler ist in der Lage sehr kurze und sehr starke Impulse zu produzieren, die mit anderen Wandlerkonstruktionen nicht erreichbar sind. Die Amplitude der produzierten Impulse ist mindestens zweimal größer als bei den klassischen Wandlern. Seine Empfindlichkeit ist mit den klassischen Konstruktionen vergleichbar. Der erfindungsgemäße Wandler lässt sich aber mit erheblich niedrigeren Kosten herstellen und überall dort einsetzen, wo auch klassische Wandlertypen verwendet werden können.The converter according to the invention is capable of very short and very strong pulses to produce that cannot be achieved with other converter designs. The The amplitude of the pulses produced is at least twice that of the classic converters. Its sensitivity is with the classic constructions comparable. However, the converter according to the invention can be used with considerably lower ones Produce costs and use them wherever classic types of converter can be used.
Zusammenfassend lässt sich sagen, dass mit dem erfindungsgemäßen Wandler im Vergleich zu anderen nicht klassischen Konstruktionen eine erhebliche Steigerung der Effektivität erreicht werden kann, da keine Verluste des elektrischen Feldes nach außenhin auftreten und alle unerwünschten Schallwellen einer fast vollständigen Dämpfung unterworfen werden, ohne dass dazu eine große Keramikdicke oder andere Dämpfungskörper benutzt werden müssten. Im Vergleich zu den klassischen Konstruktionen ist die Impulslänge kürzer und die Amplitude größer. Keine der bekannten Konstruktionen ist leichter zu fertigen.In summary, it can be said that with the converter according to the invention in A significant increase compared to other non-classic constructions effectiveness can be achieved since there are no losses of the electric field to the outside world and all unwanted sound waves of an almost complete Damping can be subjected without a large ceramic thickness or other damping bodies would have to be used. Compared to the classic Designs, the pulse length is shorter and the amplitude larger. No the known constructions are easier to manufacture.
Claims (5)
- Sonic pulse transformer for the supersonic region, for use as emitter as well as receiver, containing an elementary block (2) made of a piezoelectric material,
characterised in that
the height (h) of the elementary block (2) of the transformer consisting of the piezoelectric material exceeds its width (b), and that the block (2), at the exit end of the pulses, exhibits an appropriately adapted collar (3) shaped to provide a plane exit face for the sonic wave and forming a T in the longitudinal section, the basic polarisation being oriented vertically to the exit face and the one electrode (4) being provided in the exit face while the other electrode (5) is placed above the collar (3) and along block (2). - Sonic pulse transformer according to Claim 1,
characterised in that
block (2) has the shape of a round or polygonal pillar, a cone or a pyramid with the collar (3) being appropriately adapted. - Sonic pulse transformer according to Claim 1 or 2,
characteerised in that
the proportions of the elementary cell are selected according to a/b/h = 1/(4-6)/10, with a being the thickness of collar (3), b the diameter or the breadth of block (2), and h the height of the entire cell (1). - Sonic pulse transformer according to one or several of the preceding Claims,
characterised in that
after its shaping the elementary cell (1) is exposed to an additional radial polarisation generated by application of a high voltage. - Sonic pulse transsformer according to one or several of the Claims 1 to 4,
characterised in that
the transformer is composed of several elementary cells (1), with electrodes assigned to the cells around the pillars and similar oblong bodies, while the entity of the cells involves only one electrode in the entire exit face of the pulses.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19917429 | 1999-04-19 | ||
| DE19917429A DE19917429A1 (en) | 1999-04-19 | 1999-04-19 | Impulse sound transducer, for operating in ultrasonic range, utilizes an elementary cell consisting of a piezoceramic block and a collar shaped to it and protruding beyond it. |
| PCT/EP2000/003489 WO2000062946A1 (en) | 1999-04-19 | 2000-04-18 | Impulse sound transducer with an elementary block made of piezoelectric material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP1169143A1 EP1169143A1 (en) | 2002-01-09 |
| EP1169143B1 true EP1169143B1 (en) | 2004-12-22 |
Family
ID=7904937
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP00929375A Expired - Lifetime EP1169143B1 (en) | 1999-04-19 | 2000-04-18 | Impulse sound transducer with an elementary block made of piezoelectric material |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US6720715B1 (en) |
| EP (1) | EP1169143B1 (en) |
| AT (1) | ATE285302T1 (en) |
| CA (1) | CA2366956A1 (en) |
| DE (2) | DE19917429A1 (en) |
| PL (1) | PL351622A1 (en) |
| WO (1) | WO2000062946A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SG165984A1 (en) * | 2001-11-02 | 2010-11-29 | Product Systems Inc | Radial power megasonic transducer |
| US6984922B1 (en) * | 2002-07-22 | 2006-01-10 | Matsushita Electric Industrial Co., Ltd. | Composite piezoelectric transducer and method of fabricating the same |
| JP4473532B2 (en) * | 2002-10-10 | 2010-06-02 | 日本碍子株式会社 | Piezoelectric / electrostrictive device and manufacturing method |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3271704A (en) * | 1963-03-25 | 1966-09-06 | Bell Telephone Labor Inc | Ultrasonic delay device |
| DE2314420C3 (en) * | 1973-03-22 | 1978-03-30 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Piezoelectric button |
| US3891869A (en) * | 1973-09-04 | 1975-06-24 | Scarpa Lab Inc | Piezoelectrically driven ultrasonic generator |
| SE455538B (en) * | 1985-12-06 | 1988-07-18 | Tekniska Roentgencentralen Ab | Ultrasonic probe for testing a slotted or semi-finished piece of material |
| GB2225426B (en) * | 1988-09-29 | 1993-05-26 | Michael John Gill | A transducer |
| WO1997016260A1 (en) * | 1995-11-02 | 1997-05-09 | Sonident Anstalt | Piezoelectric ultrasonic transducer |
| US5606297A (en) * | 1996-01-16 | 1997-02-25 | Novax Industries Corporation | Conical ultrasound waveguide |
| US6777856B2 (en) * | 2001-08-02 | 2004-08-17 | Kistler Holding Ag | Crystal element for piezo sensors |
-
1999
- 1999-04-19 DE DE19917429A patent/DE19917429A1/en not_active Withdrawn
-
2000
- 2000-04-18 CA CA002366956A patent/CA2366956A1/en not_active Abandoned
- 2000-04-18 DE DE50009032T patent/DE50009032D1/en not_active Expired - Fee Related
- 2000-04-18 EP EP00929375A patent/EP1169143B1/en not_active Expired - Lifetime
- 2000-04-18 WO PCT/EP2000/003489 patent/WO2000062946A1/en active IP Right Grant
- 2000-04-18 AT AT00929375T patent/ATE285302T1/en not_active IP Right Cessation
- 2000-04-18 PL PL00351622A patent/PL351622A1/en unknown
- 2000-04-18 US US10/070,351 patent/US6720715B1/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| DE50009032D1 (en) | 2005-01-27 |
| ATE285302T1 (en) | 2005-01-15 |
| CA2366956A1 (en) | 2000-10-26 |
| WO2000062946A1 (en) | 2000-10-26 |
| DE19917429A1 (en) | 2000-10-26 |
| US6720715B1 (en) | 2004-04-13 |
| PL351622A1 (en) | 2003-05-19 |
| EP1169143A1 (en) | 2002-01-09 |
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