A differential acoustic emission and acceleration integrated piezoelectric sensor

Abstract

A differential acoustic emission and acceleration integrated piezoelectric sensor belongs to the field of aerospace technology. The differential acoustic emission and acceleration integrated piezoelectric sensor includes a connecting base, the connecting base is provided with a conductive base, the conductive base is provided with an insulating base, a piezoelectric element 1 and a piezoelectric element 2, the insulating base is provided with an upper piezoelectric sheet and a lower piezoelectric sheet, the upper piezoelectric sheet and the lower piezoelectric sheet are connected through a conductive sheet, the upper piezoelectric sheet is provided with a vibration conduction device, the vibration conduction device is connected to the shell through a spring, the upper surface of the piezoelectric element 1, the upper surface of the upper piezoelectric sheet and the lower surface of the lower piezoelectric sheet are connected to the adapter through a wire, and the upper surface of the piezoelectric element 2 and the conductive sheet are connected to the adapter through a wire. The differential acoustic emission and acceleration integrated piezoelectric sensor realizes the synchronous acquisition of vibration signals and acoustic emission signals, which can greatly reduce the error caused by separate measurements.

Description

Technical Field

[0001] The invention relates to the field of aerospace technology, and in particular to a differential acoustic emission and acceleration integrated piezoelectric sensor. Background Art

[0002] The problems caused by mechanical vibration have always been an important topic in the aviation field. The breakthrough in studying vibration problems is to study the acceleration caused by vibration, the changes in physical parameters such as the internal mechanical properties of materials, etc. Therefore, researchers will collect physical parameter data through a variety of sensors and analyze them. However, current measuring instruments such as sensors only measure a single indicator. When two or even more indicators need to be measured, multiple sensors are required, which will increase the error of the measurement data and reduce the accuracy of the data. Summary of the invention

[0003] In order to solve the technical problems existing in the prior art, the present invention provides a differential acoustic emission and acceleration integrated piezoelectric sensor, which can realize twice collection of vibration signals generated by the same vibration, and can greatly reduce the error caused by single measurement, thereby ensuring the accuracy of the measurement and reducing the difficulty of implementing the measurement.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A differential acoustic emission and acceleration integrated piezoelectric sensor, comprising a connecting base, a conductive base, an insulating base, a shell, an upper piezoelectric sheet, a lower piezoelectric sheet, a first piezoelectric element, a second piezoelectric element and a vibration conduction device;

[0006] A conductive base is arranged on the top of the connection base, an insulating base, a piezoelectric element 1 and a piezoelectric element 2 are arranged on the top of the conductive base, the insulating base is coaxially arranged with the conductive base, and the piezoelectric element 1 and the piezoelectric element 2 are arranged on both sides of the insulating base;

[0007] An upper piezoelectric sheet and a lower piezoelectric sheet are arranged in the insulating base, the upper piezoelectric sheet and the lower piezoelectric sheet are connected by a conductive sheet, a vibration conduction device is arranged on the top of the upper piezoelectric sheet, the vibration conduction device is connected to the shell through a spring, and the shell is engaged with the connection base;

[0008] The upper surface of the piezoelectric element one, the upper surface of the upper piezoelectric sheet and the lower surface of the lower piezoelectric sheet are connected to the adapter through a wire, and the upper surface of the piezoelectric element two and the conductive sheet are connected to the adapter through a wire. The specific connection method is: the upper surface of the piezoelectric element one is connected to the adapter through a wire, the upper surface of the upper piezoelectric sheet and the lower surface of the lower piezoelectric sheet are connected through a wire and then led out of the shell to be connected to the adapter through the wire; the upper surface of the piezoelectric element two and the conductive sheet are connected through a wire and then led out of the shell to be connected to the adapter through the wire.

[0009] An insulating block is arranged between the piezoelectric element 1 and the piezoelectric element 2. The piezoelectric element 1 and the piezoelectric element 2 have the same structure and are symmetrically arranged.

[0010] The insulating base, the first piezoelectric element and the second piezoelectric element are located at the same depth in the conductive base.

[0011] The vibration conducting device adopts a mass block to conduct the same vibration as the connection base.

[0012] The upper piezoelectric sheet and the lower piezoelectric sheet are both quartz piezoelectric sheets.

[0013] A connecting portion is provided at the bottom of the connecting base for connecting with a vibration component.

[0014] Beneficial effects of the present invention:

[0015] 1) The present invention can realize the acquisition of the vibration signal generated by the same vibration twice, so as to acquire multiple physical quantities such as the acceleration of the vibration of the same object and the morphological change inside the material, so as to make accurate analysis of multiple physical quantities;

[0016] 2) By effectively combining the acoustic emission sensor and the piezoelectric accelerometer, the vibration signal and the acoustic emission signal can be collected synchronously, which can greatly reduce the error caused by separate measurement and reduce the difficulty of installing multiple sensors, thereby ensuring the accuracy of the measurement and reducing the difficulty of implementing the measurement.

[0017] 3) The present invention can be applied to the collection of vibration signals of various mechanical parts, and provides data collection preparation for multi-angle research and analysis of vibration characteristics, optimization of transmission characteristics and mechanical characteristics of the structure in subsequent work.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of a front view of a differential acoustic emission and acceleration integrated piezoelectric sensor provided by an embodiment of the present invention;

[0020] Figure 2 It is a top view schematic diagram of a differential acoustic emission and acceleration integrated piezoelectric sensor provided by an embodiment of the present invention.

[0021] The reference numerals in the drawings of the specification include:

[0022] 1-connecting base, 2-conductive base, 3-insulating base, 4-housing, 5-upper piezoelectric sheet, 6-lower piezoelectric sheet, 7-piezoelectric element 1, 8-piezoelectric element 2, 9-vibration conduction device, 10-conductive sheet, 11-connecting part, 12-insulating block, 13-spring, 14-adapter. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "vertical", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "one" and "two" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0026] In order to solve the problems existing in the prior art, such as Figure 1 to Figure 2 As shown, the present invention provides a differential acoustic emission and acceleration integrated piezoelectric sensor, including a connecting base 1, a conductive base 2, an insulating base 3, a shell 4, an upper piezoelectric sheet 5, a lower piezoelectric sheet 6, a piezoelectric element 1 7, a piezoelectric element 2 8 and a vibration conduction device 9;

[0027] A conductive base 2 is arranged on the top of the connection base 1, an insulating base 3, a piezoelectric element 1 7 and a piezoelectric element 2 8 are arranged on the top of the conductive base 2, the insulating base 3 is coaxially arranged with the conductive base 2, and the piezoelectric element 1 7 and the piezoelectric element 2 8 are arranged on both sides of the insulating base 3;

[0028] An upper piezoelectric sheet 5 and a lower piezoelectric sheet 6 are arranged in the insulating base 3. Both the upper piezoelectric sheet 5 and the lower piezoelectric sheet 6 are quartz piezoelectric sheets. The upper piezoelectric sheet 5 and the lower piezoelectric sheet 6 are in a parallel structure, that is, the polarities generated on the same side are opposite. The upper piezoelectric sheet 5 and the lower piezoelectric sheet 6 are connected by a conductive sheet 10. A vibration conduction device 9 is arranged on the top of the upper piezoelectric sheet 5. The vibration conduction device 9 adopts a mass block and is used to conduct the same vibration as the connection base 1. The vibration conduction device 9 is connected to the housing 4 through a spring 13, and the housing 4 is engaged with the connection base 1.

[0029] The upper surface of the piezoelectric element 7, the upper surface of the upper piezoelectric sheet 5 and the lower surface of the lower piezoelectric sheet 6 are connected to the adapter 14 through a wire, and the upper surface of the piezoelectric element 2 8 and the conductive sheet 10 are connected to the adapter 14 through a wire. The specific connection method is: the upper surface of the piezoelectric element 7 is connected to the adapter 14 through a wire, the upper surface of the upper piezoelectric sheet 5 and the lower surface of the lower piezoelectric sheet 6 are connected through a wire and then led out of the shell 4 through a wire to connect to the adapter 14, the upper surface of the piezoelectric element 7 and the upper surface of the upper piezoelectric sheet 5 and the lower surface of the lower piezoelectric sheet 6 are all positive or negative; the upper surface of the piezoelectric element 2 8 and the conductive sheet 10 are connected through a wire and then led out of the shell 4 through a wire to connect to the adapter 14, and both are all positive or negative.

[0030] In this embodiment, the conductive base 2 is a conductive structure, and can also be paved with conductive glue. The conductive base 2 and the insulating base 3 are both circular structures, and the insulating base 3 is arranged at the center of the conductive base 2; an insulating block 12 is arranged between the piezoelectric element 1 7 and the piezoelectric element 2 8. The piezoelectric element 1 7 and the piezoelectric element 2 8 have the same structure and are symmetrically arranged on both sides of the insulating base 3. The piezoelectric element 1 7, the piezoelectric element 2 8 and the insulating block 12 also form a circular structure. The insulating block 12 supports and fixes the piezoelectric element 1 7 and the piezoelectric element 2 8, and ensures the synchronous extraction of the signal. The insulating base 3, the piezoelectric element 1 7 and the piezoelectric element 2 8 are located at the same depth in the conductive base 2.

[0031] Piezoelectric element 1 7 and piezoelectric element 2 8 are both made of PZT-5 material. Piezoelectric element 1 7 and piezoelectric element 2 8 form a differential structure, that is, the polarities generated by the two are opposite at the same top and bottom, and are connected to the conductive base 2 at the same bottom. For example, the top of piezoelectric element 1 7 is the positive pole, and is led out of the shell 4 by a wire, and the top of piezoelectric element 2 8 is the negative pole, and is led out of the shell 4 by a wire and connected to the conductive sheet 10. The conductive base 2 is fixed to the connecting base 1, and the bottom of the connecting base 1 is provided with a connecting portion 11 for connecting the vibration component. The connecting portion 11 is fixed on the vibration part, such as a bolt hole. The connecting base 1 is engaged with the metal shell 4 above it, so that all sensor components are arranged inside the shell 4. Since the frequencies of the acoustic emission sensor and the piezoelectric acceleration sensor are different, the top of the shell 4 is connected to the spring 13 and connected to the mass block to damp its vibration. In subsequent processing, the adapter 14 can be connected to the amplifier circuit for signal processing.

[0032] The working principle of the above-mentioned differential acoustic emission and acceleration integrated piezoelectric sensor is as follows:

[0033] The piezoelectric element 1 7 and the piezoelectric element 2 8 constitute an acoustic emission sensor, which converts the mechanical vibration generated by the vibration components such as the engine into an electrical signal through two differentially placed piezoelectric elements; when the present invention is actually used, in order to ensure the symmetry of the structure and the symmetry of the positive and negative poles of the output signal, the requirements for the piezoelectric elements are relatively strict, and two piezoelectric elements with the same specifications and the same material performance parameters produced in the same batch are selected and placed in the conductive base 2, so that the signal measurement is more accurate; in the subsequent processing, the electrical signal can be received by the acoustic emission detection system, and then it can be processed and analyzed to infer the property changes inside the material;

[0034] The upper piezoelectric sheet 5, the lower piezoelectric sheet 6 and the conductive sheet 10 constitute a piezoelectric acceleration sensor. When the piezoelectric acceleration sensor senses vibration, the vibration transmission device 9 has the same vibration as the connection base 1, and the vibration transmission device 9 has an alternating force proportional to the acceleration acting on the piezoelectric sheet; due to the piezoelectric effect of the piezoelectric sheet, alternating charges are generated on the two surfaces. When the vibration frequency is much lower than the natural frequency of the sensor, the output charge (voltage) of the sensor is proportional to the force, that is, proportional to the acceleration of the vibrating component; in subsequent processing, the acceleration can be obtained through an external circuit, such as adding a suitable integration circuit to the amplifier, the vibration speed or displacement of the test piece can be measured;

[0035] The acoustic emission sensor and the piezoelectric acceleration sensor are combined by connecting the base 1, the conductive base 2, the insulating base 3, the shell 4, the vibration conduction device 9 and other components, thereby realizing the measurement of two index data, improving the synchronization performance of data acquisition, greatly reducing the experimental error, improving the accuracy, and effectively avoiding the problems of poor synchronization performance of existing single-function sensors during information fusion online monitoring.

[0036] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A differential acoustic emission and acceleration integrated piezoelectric sensor, characterized in that: It includes a connecting base, a conductive base, an insulating base, a shell, an upper piezoelectric sheet, a lower piezoelectric sheet, a first piezoelectric element, a second piezoelectric element and a vibration transmission device; A conductive base is arranged on the top of the connection base, an insulating base, a piezoelectric element 1 and a piezoelectric element 2 are arranged on the top of the conductive base, the insulating base is coaxially arranged with the conductive base, and the piezoelectric element 1 and the piezoelectric element 2 are arranged on both sides of the insulating base; An upper piezoelectric sheet and a lower piezoelectric sheet are arranged in the insulating base, the upper piezoelectric sheet and the lower piezoelectric sheet are in a parallel structure, the upper piezoelectric sheet and the lower piezoelectric sheet are connected by a conductive sheet, a vibration conduction device is arranged on the top of the upper piezoelectric sheet for conducting the same vibration as the connection base, the vibration conduction device is connected to the housing through a spring, and the housing is engaged with the connection base; The upper surface of the piezoelectric element 1, the upper surface of the upper piezoelectric sheet and the lower surface of the lower piezoelectric sheet are connected to the adapter through a wire, and the upper surface of the piezoelectric element 2 and the conductive sheet are connected to the adapter through a wire; The upper surface of the piezoelectric element 1 is connected to the adapter through a wire, the upper surface of the upper piezoelectric sheet and the lower surface of the lower piezoelectric sheet are connected through the wire and then led out of the shell through the wire to connect with the adapter, and the upper surface of the piezoelectric element 1, the upper surface of the upper piezoelectric sheet and the lower surface of the lower piezoelectric sheet are all positive or negative. The upper surface of the piezoelectric element 2 is connected to the conductive sheet through a wire and then led out of the shell through the wire to connect to the adapter. Both are positive or negative electrodes. The piezoelectric element 1 and the piezoelectric element 2 form a differential structure.

2. The differential acoustic emission and acceleration integrated piezoelectric sensor according to claim 1, characterized in that: An insulating block is arranged between the piezoelectric element 1 and the piezoelectric element 2. The piezoelectric element 1 and the piezoelectric element 2 have the same structure and are symmetrically arranged.

3. The differential acoustic emission and acceleration integrated piezoelectric sensor according to claim 1, characterized in that: The insulating base, the first piezoelectric element and the second piezoelectric element are located at the same depth in the conductive base.

4. The differential acoustic emission and acceleration integrated piezoelectric sensor according to claim 1, characterized in that: The vibration conducting device adopts a mass block to conduct the same vibration as the connection base.

5. The differential acoustic emission and acceleration integrated piezoelectric sensor according to claim 1, characterized in that: The upper piezoelectric sheet and the lower piezoelectric sheet are both quartz piezoelectric sheets.

6. The differential acoustic emission and acceleration integrated piezoelectric sensor according to claim 1, characterized in that: A connecting portion is provided at the bottom of the connecting base for connecting with a vibration component.

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