A piezoelectric acoustic sensor

Abstract

This utility model discloses a piezoelectric acoustic sensor, including a transducer, a preamplifier, and an adapter structure. Sound waves act on the outer shell at the bottom of the transducer, and the shell transmits pressure to the piezoelectric element, causing polarization within the element. Through a series of processes, the sound signal is converted into an electrical signal. The piezoelectric acoustic sensor has a closed structure, requiring no sound-permeable hole, allowing it to adapt to harsh environments. It can also measure relatively large sound pressure levels and has a wide temperature range, operating from -40℃ to 120℃.

Description

Technical Field

[0001] This utility model relates to the field of acoustic sensor technology, and in particular to a piezoelectric acoustic sensor. Background Technology

[0002] The acoustic sensor industry is in a phase of rapid development, with continuously growing market demand driving its ongoing progress. With the rapid development of technologies such as the Internet of Things, big data, and cloud computing, acoustic sensors are being used more and more widely in various fields, such as oil and gas exploration, traffic noise monitoring, groundwater level monitoring, earthquake monitoring, and smart cities. The rapid development of these application areas provides the acoustic sensor industry with a vast market space and growth momentum.

[0003] However, in harsh high sound pressure scenarios, such as detecting explosives, conventional condenser microphones are often unable to meet practical needs due to their structural or material limitations. Summary of the Invention

[0004] To overcome the shortcomings of the above-mentioned technologies, this utility model proposes a piezoelectric acoustic sensor, comprising a transducer, a preamplifier, and an adapter structure:

[0005] (1) The transducer comprises a transducer housing, a piezoelectric sheet group consisting of a first piezoelectric sheet, a conductive sheet, and a second piezoelectric sheet stacked coaxially, as well as a mass block and a connector fixing block;

[0006] The piezoelectric element assembly is pressed and fixed inside the transducer housing by an insulating sleeve;

[0007] The mass block is located on the upper side of the piezoelectric sheet assembly, the connector fixing block is located on the upper side of the mass block, and a locking nut is provided on the upper side of the connector fixing block. The locking nut is fixed by the thread on the inner wall of the transducer housing.

[0008] The connector fixing block is provided with exposed electrical connectors;

[0009] (2) The preamplifier includes a probe that contacts the electrical connector, a probe holder that fixes the probe, a signal processing board that connects the probe, a connector that connects the signal processing board, an adapter sleeve that fixes the connector, and a front housing that accommodates the above components.

[0010] (3) The transducer and the preamplifier are connected through the adapter structure;

[0011] Preferably, a conductive path is provided between the conductive sheet and the center electrode of the electrical connector, penetrating the insulating sleeve and the connector fixing block;

[0012] Preferably, the two ends of the adapter structure have different diameters. The end with the larger diameter is connected to the transducer via a threaded structure, and the end with the smaller diameter is connected to the preamplifier via a threaded structure.

[0013] Preferably, the connector fixing block has internal threads, and the electrical connector is fixed to the inside of the connector fixing block by the threads;

[0014] Preferably, the interface includes an adapter sleeve and a connector, the adapter sleeve having internal threads, and the connector being fixed inside the adapter sleeve by the threads;

[0015] Preferably, the bottom of the transducer housing is a sound pressure receiving surface, and an annular groove is provided inside it.

[0016] This invention proposes a piezoelectric acoustic sensor. Sound waves act on a housing, which transmits pressure to a piezoelectric element, causing it to deform. This deformation generates polarization within the piezoelectric element, and through a series of processes, the sound signal is converted into an electrical signal. The advantages of this invention are: the piezoelectric acoustic sensor has a closed structure, requiring no sound-permeable hole, allowing it to adapt to harsh environments and measure relatively high sound pressure levels; it also has a wide temperature adaptability, operating from -40℃ to 120℃. Attached Figure Description

[0017] Figure 1 This is a cross-sectional structural diagram of a piezoelectric acoustic sensor according to the present invention;

[0018] Figure 2 This is a structural diagram of the internal part of the transducer of a piezoelectric acoustic sensor according to the present invention.

[0019] Figure 3 This is a longitudinal cross-sectional view of the transducer housing of a piezoelectric acoustic sensor according to this utility model.

[0020] Figure 4 This is a schematic diagram of the transducer of a piezoelectric acoustic sensor according to the present invention;

[0021] Figure 5 This is a schematic diagram of a preamplifier for a piezoelectric acoustic sensor according to the present invention;

[0022] Figure 6 This is a schematic diagram of the appearance of a piezoelectric acoustic sensor according to the present invention. Detailed Implementation

[0023] The following are specific embodiments of the present invention, and the technical solution of the present invention will be further described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0024] like Figure 1As shown, it specifically includes: transducer housing 1, insulating sleeve 2, connector fixing block 3, first locking nut 4, mass block 5, electrical connector 6, adapter structure 7, front housing 8, connector 9, signal processing board 10, probe fixing plate 11, second locking nut 12, probe 13, probe base 14, adapter sleeve 15, first piezoelectric sheet 16, second piezoelectric sheet 17, and conductive sheet 18.

[0025] Figure 2 Includes insulating sleeve 2, connector fixing block 3, notch 101, and round hole 102. Figure 3 Includes transducer housing 1 and annular groove 103, Figure 4 Including transducer 201 and transition structure 7, Figure 5 For preamplifier 202, Figure 6 This is an overall view of the piezoelectric acoustic sensor.

[0026] A lead wire is welded to one end of the conductive sheet 18. The first piezoelectric sheet 16, the conductive sheet 18 and the second piezoelectric sheet 17 are coaxially stacked at the bottom of the transducer housing 1. The insulating sleeve 2 is fitted over the outside of the above structure and pressed and fixed to the bottom of the transducer housing. The insulating sleeve 2 is annular and has a notch 101 on its surface. The lead wire of the conductive sheet 18 is led out upward from this notch 101.

[0027] Furthermore, a mass block 5 is placed on the second piezoelectric sheet 17. The top of the mass block 5 has a groove that matches the circular structure at the bottom of the connector fixing block 3. One end of the electrical connector 6 has a threaded structure that can be directly screwed into the threaded hole inside the connector fixing block 3. The other end of the electrical connector 6 is exposed and used to connect with the probe 13. A first locking nut 4 is placed on the connector fixing block 3. The first locking nut 4 is fixed by the threaded structure on the inner wall of the transducer housing 1, thus forming the transducer 201.

[0028] Furthermore, the bottom of the transducer housing 1 is a sound pressure receiving surface, and there is an annular groove 103 inside it. The thickness of the housing at the groove is only 0.4 mm. The sound pressure change causes the housing at the groove to vibrate, thereby driving the vibration of the entire bottom, which generates pressure on the first piezoelectric sheet 16 and the second piezoelectric sheet 17. The piezoelectric material converts the pressure into charge based on its own properties, and further converts it into an electrical signal through a series of processes, thus realizing the conversion of sound signal into electrical signal.

[0029] Furthermore, corresponding components are soldered onto the signal processing board 10, the connector 9 is screwed into the internal thread of the adapter sleeve 15, and then the signal processing board 10 with the soldered components is soldered onto the connector 9. A lead wire is soldered to the other end of the signal processing board 10, and the lead wire is longer than the front housing 8. The adapter sleeve 15 is screwed into the internal thread of one end of the front housing 8, and the lead wire passes through the front housing 8 and comes out from the other end.

[0030] Furthermore, the lead wire passing through the front housing 8 is soldered to the probe fixing plate 11. There is a step inside the other end of the front housing 8. The probe 13 is soldered to the probe fixing plate 11 and placed on the step. Then the probe seat 14 presses down on the probe fixing plate 11 and the second locking nut 12 is tightened to fix it. The probe seat 14 is made of insulating material to prevent the probe from conducting with the housing.

[0031] Furthermore, the adapter structure 7 is tapered, and the preamplifier 202 is connected to the transducer 201 through a threaded structure. Finally, the receiver is screwed tightly to the preamplifier, sealed with glue, and thus constitutes a complete piezoelectric acoustic sensor.

Claims

1. A piezoelectric acoustic sensor, comprising a transducer, a preamplifier, and an adapter structure, characterized in that: (1) The transducer comprises a transducer housing, a piezoelectric sheet group consisting of a first piezoelectric sheet, a conductive sheet, and a second piezoelectric sheet stacked coaxially, as well as a mass block and a connector fixing block; The piezoelectric element assembly is pressed and fixed inside the transducer housing by an insulating sleeve; The mass block is located on the upper side of the piezoelectric sheet assembly, the connector fixing block is located on the upper side of the mass block, and a locking nut is provided on the upper side of the connector fixing block. The locking nut is fixed by the thread on the inner wall of the transducer housing. The connector fixing block is provided with exposed electrical connectors; (2) The preamplifier includes a probe that contacts the electrical connector, a probe holder that fixes the probe, a signal processing board that connects the probe, a connector that connects the signal processing board, an adapter sleeve that fixes the connector, and a front housing that accommodates the above components. (3) The transducer and the preamplifier are connected through the adapter structure.

2. The piezoelectric acoustic sensor according to claim 1, characterized in that, A conductive path is provided between the conductive sheet and the center electrode of the electrical connector, passing through the insulating sleeve and the connector fixing block.

3. The piezoelectric acoustic sensor according to claim 1, characterized in that, The two ends of the adapter structure have different diameters. The end with the larger diameter is connected to the transducer through a threaded structure, and the end with the smaller diameter is connected to the preamplifier through a threaded structure.

4. The piezoelectric acoustic sensor according to claim 1, characterized in that, The connector fixing block has internal threads, and the electrical connector is fixed inside the connector fixing block by the threads.

5. The piezoelectric acoustic sensor according to claim 1, characterized in that, The adapter sleeve has internal threads, and the connector is fixed inside the adapter sleeve by the threads.

6. The piezoelectric acoustic sensor according to claim 1, characterized in that, The bottom of the transducer housing is a sound pressure receiving surface, and an annular groove is provided inside it.

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