SU621135A1 - Piezoelectric transducer - Google Patents

Description

The invention relates to non-destructive testing methods and can be used, in particular, for ultrasonic flaw detection and medical diagnostics. tiki.

Ultrasonic sensors are known that contain an active piezoelectric element and a damper, which is made integral with the active piezoelectric element in the form of an absorbing element l, 2J.

The disadvantage of these piezoelectric transducers is the presence of a matching transformer that provides matching of the resistance of the piezoelectric element with the input and output resistances of the gearboxes of the equipment, which reduces the accuracy of control of the materials under study.

The closest in technical essence to the proposed is a piezoelectric transducer containing a piezoelectric element, a damper and a matching transformer 3.

A disadvantage of the known device is the low accuracy of the control, caused by the small steepness of the leading front. This impulse and a small fragment of damping of oscillations in piezoelectric plastic. The use of various composite dampers, for example, made from a mixture of tungsten powder and epoxy resin, does not lead to the complete absorption of the vibrations emitted by the non-working surface of the piezoelectric element, and placing a matching transformer in the piezoelectric converter case increases the size and weight of the ultrasonic sensor.

The purpose of the invention is to increase the resolution of the device.

Claims (3)

The goal is achieved by the fact that a piezoelectric element, a damper and a matching transformer are made of a piezoactive material in the form of a single design with the front and current-carrying electrodes of the piezoelectric element and the front and thickness electrodes of the matching transformer, with one thick electrode of the co-transformer being connected to the current component and the current component of the current component and the component and the current component of the current component and the current component of the current component and the current component of the current component of the current component of the current component and the current component of the current component of the current component of the current component of the current component and the component of the current component of the current component and the component of the current component of the current component and the component of the current component of the current component and the component of the current component of the current component and the object is connected Thick electrode with grounded electrode The drawing schematically shows the proposed device. The Hz bezoelectric transducer contains end 1 and ring 2 electrodes of the piezoelectric element 3, thickness 4, 5, and end 6 electrodes of the piezotransformer 7,. The Converter works as follows. When the generator of radio pulses is connected to the pro: imam abb, piezotransformer is excited in the piezotransformer, which is converted into an electrical signal taken from the thickness electrode 4. The transformation ratio of the piezoelectric transformer 7 is chosen optimal for matching the input resistance of the piezoelectric element. 3 O; output resistance of the generator of electrical signals. Frequency and about Loyi radio pulses supplied by the center p | Transform) The rmator is chosen equal to its fteaoHaHCHoft frequency. The electrical signal from the piezotransformer 7 is fed to the ring electrode 2, excites the ultrasonic signal that is radiated into the working medium by the end electrode 1. In case of optimal matching of the piezoelectric element 3 with the electrical generator (the maximum voltage of the ultrasonic signal is maximal. The ultrasonic wave propagating c in the rod is absorbed by the damper, which is made integral with the active piezoelectric element in the form of a piezoelectric transformer. In this way, in the proposed piezoelectric transducer The mapping of the active piezoelectric element with the receiver transducer is performed, thereby increasing the control accuracy of the 6 4 s parameter of the test material. With the aid of the damper matched with the piezoelectric transducer, the mode of the driving wave in the piezoelectric transducer, i.e. emitted by an ultrasonic pulse. The possibility of using monolithic piezoelectrics makes it possible to simplify the technology of making such converters and Stich good repeats emosti parameters, since otsutstvut takie.otvetstvennye operation as watering damper and manufacturing soglaen transformer. Claims of the invention A piezoelectric transducer comprising a piezoelectric element, a damper and a matching transformer, characterized in that, in order to increase the resolution of the device, the piezoelectric element, the damper and the matching transformer are made of piezo-active material in the form of a single structure. with the end and current-carrying electrodes of the piezoelectric element and the end and thickness electrodes of the matching transformer, with one thickness electrode of the matching transformer connected with the current-carrying electrode of the piezoelectric element, and its other thickness electrode is connected to a grounded electrode of the piezoelectric element. Sources of information taken into account during the examination: 1. Author's certificate No. 539265 ,. , cl. Q01 N 29 / OO, 1975. 2. The copyright certificate number 434623, cl. H C4 1 17/00, 1972, 3. Copyrights certificate NO 423033, cl. QOi N29 / 04, 1974.