CN115971022A - Acoustic signal transmitting device - Google Patents

Abstract

The invention belongs to the field of acoustic detection, and specifically relates to an acoustic signal transmitting device; the device includes: a metal plate, a matching layer, an electrode sheet, a piezoelectric composite material, an electrode sheet and a backing layer are stacked and connected sequentially from top to bottom, and the metal plate The first acoustic emission sensor and the second acoustic emission sensor are arranged on it; the present invention uses the piezoelectric composite material as the excitation material, uses the matching layer to increase the vibration mode, and then sticks a metal plate of a certain shape on the matching layer to form a multi-mode coupling Finally, an ultrasonic emission structure with a vibration frequency range of 30kHz to 500kHz is obtained, which can effectively solve the problem that the existing single ultrasonic transmitter is difficult to cover this frequency band.

Description

An acoustic signal transmitter

technical field

The invention belongs to the field of acoustic detection, and in particular relates to an acoustic signal emitting device.

Background technique

The bending vibration of the structure, the frequency range is usually 40kHz to 80kHz, the piezoelectric longitudinal vibration composite rod transducer is usually about a few kHz to 100kHz, and the frequency range of the ultrasonic sensor for the resonant flowmeter based on the piezoelectric ceramic thickness direction is usually 100kHz Therefore, it is difficult to find an acoustic emission structure that can cover the frequency range of 40kHz to 500kHz in existing products. Sensor testing and other applications provide a feasible solution.

Piezoelectric composite material is a common material used to increase bandwidth in underwater acoustic transducers. Piezoelectric composite material plus matching layer can obtain multiple working frequency bands, and coupled with the vibration coupling of metal plates, more work can be obtained frequency and a wider operating frequency band. Based on the above ideas, there is an urgent need for an acoustic signal transmitter consisting of a piezoelectric composite material, a matching layer and a metal plate that can cover a wide frequency range.

Contents of the invention

In view of the deficiencies in the prior art, the present invention proposes an acoustic signal transmitting device, which includes: a metal plate 1, a matching layer 7, an electrode sheet 2, a piezoelectric composite material 3, an electrode sheet 4 and a backing layer 5; The metal plate 1 , the matching layer 7 , the electrode sheet 2 , the piezoelectric composite material 3 , the electrode sheet 4 and the backing layer 5 are sequentially stacked and connected from top to bottom.

Preferably, the piezoelectric composite material 3 includes a piezoelectric column part and a filler part, and the piezoelectric composite material 3 is formed by interfitting the piezoelectric column part and the filler part.

Further, the filling part is a honeycomb grid column structure, and the piezoelectric column part is a column structure cooperating with the filling part.

Preferably, the manufacturing process of the piezoelectric composite material 3 includes:

The first step: the piezoelectric ceramic sheet is bonded to the substrate with an adhesive, the surface of the piezoelectric ceramic disc is coated with a protective layer, and the piezoelectric ceramic disc coated with the protective layer is cut to obtain a piezoelectric ceramic column array of components;

The second step: the array composed of piezoelectric ceramic columns is poured to form a filler between the piezoelectric ceramic columns;

The third step: remove the substrate to obtain the intermediate piezoelectric composite material; perform surface treatment on the intermediate piezoelectric composite material, and use a solvent to remove the protective layer on the surface of the intermediate piezoelectric composite material, so that the original silver electrode of the piezoelectric ceramic disc is exposed come out;

Step 4: Connect all the silver electrodes on the front and back of the intermediate piezoelectric composite material in parallel by coating conductive glue or metal electrodes to form a conductive layer to obtain the prepared piezoelectric composite material.

Preferably, the matching layer 7 , the electrode sheet 2 , the piezoelectric composite material 3 , the electrode sheet 4 and the backing layer 5 are all circular in shape and have the same area.

Preferably, the area of the metal plate 1 is larger than that of the matching layer 7 , the electrode sheet 2 , the piezoelectric composite material 3 , the electrode sheet 4 and the backing layer 5 .

The beneficial effects of the present invention are as follows: the present invention adopts the metal plate 1, the electrode sheet 2, the piezoelectric composite material 3, the electrode sheet 4 and the backing layer 5 to be sequentially stacked and connected, and the 1-3 type piezoelectric composite material is used as the excitation material , the matching layer is used to increase the vibration mode, and a metal plate of a certain shape is glued on the matching layer to form a multi-mode coupling vibration structure. Finally, an ultrasonic emission structure with a vibration frequency range of 30kHz to 500kHz is obtained, which can effectively solve the existing problems. It is difficult for a single ultrasonic transmitter to cover this frequency band.

Description of drawings

Fig. 1 is a side view of the structure of an acoustic signal transmitting device in the present invention;

Fig. 2 is an exploded view of the structure of the acoustic signal transmitting device in the present invention;

Fig. 3 is the schematic diagram of the first step of the manufacturing process of the piezoelectric composite material in the present invention;

Fig. 4 is the second schematic diagram of the manufacturing process of the piezoelectric composite material in the present invention;

Fig. 5 is the schematic diagram of the third step of the manufacturing process of the piezoelectric composite material in the present invention;

Fig. 6 is the schematic diagram of the fourth step of the manufacturing process of the piezoelectric composite material in the present invention;

Fig. 7 is a partial schematic diagram of the piezoelectric column of the piezoelectric composite material in the present invention;

Fig. 8 is a partial schematic diagram of the filler of the piezoelectric composite material in the present invention;

In the figure: 1. Metal plate; 2. Electrode sheet; 3. Piezoelectric composite material; 31. Piezoelectric ceramic column; 32. Piezoelectric ceramic electrode; 33. Substrate; 34. Filler; 4. Electrode sheet; 5. Backing layer; 61, first acoustic emission sensor; 62, second acoustic emission sensor; 7, matching layer.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The present invention proposes an acoustic signal transmitting device, as shown in Fig. 1 and Fig. 2, the device comprises: a metal plate 1, a matching layer 7, an electrode sheet 2, a piezoelectric composite material 3, an electrode sheet 4 and a backing layer 5; the metal plate 1, the matching layer 7, the electrode sheet 2, the piezoelectric composite material 3, the electrode sheet 4 and the backing layer 5 are sequentially stacked and connected from top to bottom.

Preferably, the vibration amplitudes at the installation positions of the first acoustic emission sensor 61 and the second acoustic emission sensor 62 are the same.

As shown in FIG. 7 and FIG. 8 , preferably, the piezoelectric composite material 3 includes a piezoelectric column part and a filler part, and the piezoelectric composite material 3 is formed by interfitting the piezoelectric column part and the filler part.

Further, the filling part is a honeycomb grid column structure, and the piezoelectric column part is a column structure cooperating with the filling part.

Preferably, the piezoelectric composite material 3 can be made of piezoelectric ceramic discs, and the specific implementation process is as follows:

The first step: as shown in Figure 3, the piezoelectric ceramic sheet is bonded to the substrate 33 with an adhesive, the surface of the piezoelectric ceramic disc is coated with a protective layer, and then the piezoelectric ceramic sheet coated with the protective layer is The sheet is cut into an array of piezoelectric ceramic columns 31. After the cutting is completed, the original electrodes 32 of the piezoelectric ceramic sheet still remain on the piezoelectric ceramic columns 31;

Step 2: as shown in FIG. 4 , use a mold to cast the array of piezoelectric ceramic pillars obtained in the first step, and form fillers 34 between the piezoelectric ceramic pillars;

Step 3: As shown in Figure 5, after the filler is cured, the substrate is removed to form the intermediate piezoelectric composite material shown in the figure, and the intermediate piezoelectric composite material is surface treated, and the intermediate piezoelectric composite material is removed using a solvent. The protective layer on the surface of the composite material exposes the original silver electrode of the piezoelectric ceramic disc;

Step 4: As shown in Figure 6, connect all the silver electrodes on the front and back of the intermediate piezoelectric composite material in parallel to form conductive layers 35 and 36 by coating conductive glue or transition metal electrodes to obtain the prepared piezoelectric composite material.

In FIGS. 3 to 6, only the electrode 32 on one piezoelectric column is marked as a representative. In fact, the upper and lower surfaces of all the piezoelectric columns retain the original electrodes of the piezoelectric ceramic sheet.

Preferably, the electrode sheet 2 and the electrode sheet 4 can be processed metal electrodes, and then stick to both sides of the piezoelectric composite material with conductive glue, etc. The positive and negative electrodes are created on both sides of the electrical composite.

Preferably, the matching layer 7 , the electrode sheet 2 , the piezoelectric composite material 3 , the electrode sheet 4 and the backing layer 5 are all circular in shape and have the same area.

Preferably, the area of the metal plate 1 is larger than that of the matching layer 7 , the electrode sheet 2 , the piezoelectric composite material 3 , the electrode sheet 4 and the backing layer 5 .

One working mode of the present invention is as an ultrasonic probe combined with transmitting and receiving, through the vibration of the piezoelectric composite material, the overall vibration of the structure is excited, and the ultrasonic wave is emitted to the propagation medium, and after being reflected by the measured object, it is received by the structure. Finally, a voltage signal is detected on the electrode sheet 2 and the electrode sheet 4 on both sides of the piezoelectric composite material. At this time, the device can be used as an ultrasonic emission device that penetrates a metal plate with a certain thickness, and can pass through the piezoelectric composite material and A variety of vibration modes of the metal substrate are coupled to form a wide operating frequency band, or work at multiple frequency points.

Another working mode of the present invention is as an ultra-wideband acoustic emission signal simulation device. At this time, a plurality of acoustic emission sensors are arranged on the metal plate. Preferably, two acoustic emission sensors are arranged on the metal plate, respectively These are the first acoustic emission sensor 61 and the second acoustic emission sensor 62 . Put the device in the working state of the approximate free boundary, and fix the acoustic emission sensors 61 and 62 above the metal plate in the same way, and the fixed position can be selected by structural simulation or laser vibration measurement. The vibration amplitude is equal or close to position in order to improve the test accuracy.

The orientation terms such as "upper" and "lower" expressed in the above schemes are only for the convenience of description, and are not used to limit the absolute orientation of the present invention when it is implemented. The change or adjustment of its relative relationship is not essential. Changes in technical content should also be regarded as the scope of the present invention that can be implemented.

In the present invention, unless otherwise clearly specified and limited, terms such as "arrangement" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical The connection can also be an electrical connection; it can be a direct connection or an indirect connection through an intermediary, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined, for ordinary people in this field Those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

The above examples have further described the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above examples are only preferred implementations of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made to the present invention within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. An acoustic signal transmitting apparatus, comprising: the piezoelectric ceramic comprises a metal plate (1), a matching layer (7), an electrode plate (2), a piezoelectric composite material (3), an electrode plate (4) and a backing layer (5); the metal plate (1), the matching layer (7), the electrode plate (2), the piezoelectric composite material (3), the electrode plate (4) and the backing layer (5) are sequentially stacked and connected from top to bottom.

2. The acoustic signal transmission device according to claim 1, wherein the piezoelectric composite material (3) comprises a piezoelectric pillar portion and a filler portion, and the piezoelectric composite material (3) is formed by the piezoelectric pillar portion and the filler portion being fitted to each other.

3. An acoustic signal transmission device according to claim 3, wherein the filler part is of a honeycomb lattice column structure and the piezoelectric column part is of a pillar structure which is fitted with the filler part.

4. The acoustic signal emitting device according to claim 1, wherein the piezoelectric composite material (3) is produced by a process comprising:

the first step is as follows: adhering the piezoelectric ceramic wafer to a substrate by using an adhesive, coating a protective layer on the surface of the piezoelectric ceramic wafer, and cutting the piezoelectric ceramic wafer coated with the protective layer to obtain an array consisting of piezoelectric ceramic columns;

the second step: pouring an array formed by the piezoelectric ceramic columns to form fillers among the piezoelectric ceramic columns;

the third step: removing the substrate to obtain an intermediate piezoelectric composite material; performing surface treatment on the intermediate piezoelectric composite material, and removing a protective layer on the surface of the intermediate piezoelectric composite material by using a solvent to expose the original silver electrode of the piezoelectric ceramic wafer;

the fourth step: and respectively connecting all silver electrodes on the front surface and the back surface of the middle piezoelectric composite material in parallel by using a mode of coating conductive adhesive or a transition metal electrode to form a conductive layer, thus obtaining the manufactured piezoelectric composite material.

5. The acoustic signal transmission device according to claim 1, wherein the matching layer (7), the electrode sheet (2), the piezoelectric composite material (3), the electrode sheet (4) and the backing layer (5) are all circular in shape and have the same area.

6. The acoustic signal transmission device according to claim 1, wherein the metal plate (1) has an area larger than the matching layer (7), the electrode sheet (2), the piezoelectric composite material (3), the electrode sheet (4) and the backing layer (5).

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