Multifunctional Piezoelectric Performance Testing Device

Abstract

The present invention discloses a multifunctional piezoelectric performance testing device. The multifunctional piezoelectric performance testing device includes a U-shaped support rod, a support straight rod, an insulating support table, and an electromagnetic controller; the U-shaped support rod has a long rod and a short rod, the long rod passes through a through hole of the insulating support table and is connected to a support spring, and one end of the short rod and the support straight rod clamps a sample to be tested; the other end of the support straight rod relatively far from the sample to be tested passes through a through hole of the insulating support table and is connected to a vibration source; the conversion between the free vibration state and the clamped vibration state of the sample to be tested is achieved by turning on or off the electromagnetic controller.

Description

Technical Field

[0001] The present invention relates to the technical field of piezoelectric performance testing, and particularly to a multifunctional piezoelectric performance testing device. Background Art

[0002] Piezoelectric ceramic materials are an important class of functional materials that can generate net charges on the material surface under the action of an external force. Piezoelectric coefficient and electromechanical coupling coefficient are two key technical indicators for evaluating the piezoelectric performance of piezoelectric ceramic materials. The quasi-static method and the dynamic resonance method are the most widely used piezoelectric performance testing methods at present, and national standards GB11309-89 and GB / T3389-2008 have been formed respectively. The quasi-static method is mainly used to measure the piezoelectric coefficient of piezoelectric ceramics, such as d 33 . The testing equipment d 33 tester, such as the ZJ-3 type d 33 piezoelectric measuring instrument, etc., can be used for the piezoelectric performance testing of the quasi-static method. The dynamic resonance method is mainly used to measure the electromechanical coupling coefficient of piezoelectric ceramics. The testing equipment impedance analyzer, such as Keysight 4990, etc., can be used for the piezoelectric performance testing of the dynamic resonance method. However, the quasi-static method and the dynamic resonance method respectively require the piezoelectric ceramic material to be in a clamped vibration state and a free vibration state. Therefore, in the existing testing devices, different testing equipment and corresponding testing fixtures need to be used to perform the piezoelectric performance testing. At the same time, the piezoelectric ceramic samples also need to be continuously placed and removed from the corresponding testing equipment, so the testing efficiency is relatively low. At present, there is no testing device that can synchronously integrate the quasi-static method and the dynamic resonance method in a single time. Summary of the Invention

[0003] In view of the above problems, the present invention proposes a multifunctional piezoelectric performance testing device that can realize the conversion between the clamped vibration state and the free vibration state, and can synchronously measure different piezoelectric performances of the quasi-static method and the dynamic resonance method without changing the loaded samples, reducing the time cost and labor cost brought by continuously placing and removing the piezoelectric ceramic samples, and greatly improving the testing efficiency.

[0004] The present invention is realized through the following technical solutions:

[0005] The present invention provides a multifunctional piezoelectric property testing device, which includes a U-shaped support rod, a support straight rod, an insulating support table and an electromagnetic controller; the U-shaped support rod has a long rod and a short rod, the long rod passes through a through hole of the insulating support table and is connected to a support spring, and one end of either the short rod or the support straight rod clamps the sample to be tested; the other end of the support straight rod, which is relatively far from the sample to be tested, passes through the through hole of the insulating support table and is connected to a vibration source; by turning on or off the electromagnetic controller, the conversion between the free vibration state and the clamped vibration state of the sample to be tested can be achieved; when the electromagnetic controller switch is turned on, the magnetic force generated by the electromagnetic controller locks the long rod of the U-shaped support rod, and the sample to be tested is in the clamped vibration state through the connection between the support straight rod and the vibration source; when the electromagnetic controller switch is turned off, the electromagnetic controller does not generate magnetic force, and the long rod of the U-shaped support rod is in a free telescopic state. Therefore, the end of the short rod of the U-shaped support rod contacts the sample to be tested without applying a clamping force, so that the sample to be tested is in the free vibration state.

[0006] Preferably, the central axes of the support straight rod and the short rod of the U-shaped support rod are the same straight line.

[0007] Preferably, the end of the short rod of the U-shaped support rod and the end of the support straight rod in contact with the sample to be tested are both hemispherical.

[0008] Preferably, the quasi-static parameters measured when the sample to be tested is in the clamped vibration state include the piezoelectric coefficient.

[0009] Preferably, the dynamic resonance parameters measured when the sample to be tested is in the free vibration state include the electromechanical coupling coefficients Kt and / or Kp.

[0010] Preferably, the telescopic displacement of the support spring is adjustable between 0 - 5 cm.

[0011] Preferably, the vibration source has an output with a frequency of 30 Hz to 300 Hz and a pressure of 0.05 N to 0.5 N.

[0012] Preferably, the U-shaped support rod and the support straight rod also serve as electrodes at the same time.

[0013] Preferably, the insulating support table is provided with a mounting groove, and the mounting groove communicates with a limiting groove on the insulating support table to form a through hole. The U-shaped support rod is connected to the support spring through the mounting groove and the limiting groove.

[0014] Preferably, the insulating support table is provided with a mounting groove, and the mounting groove communicates with a limiting groove on the insulating support table to form a through hole. The support straight rod is connected to the vibration source through the mounting groove and the limiting groove.

[0015] The multi-functional piezoelectric performance testing device proposed by the present invention, which can realize the conversion between the free vibration state and the clamped vibration state, can measure the multi-parameter piezoelectric performance of piezoelectric materials by using the quasi-static method and the dynamic resonance method respectively under the condition of single sample loading once, simplifying the testing process. Especially in the testing of high-temperature piezoelectric performance, it is not necessary to take out the sample to be tested from the heating furnace cavity, and the quasi-static method testing and the dynamic resonance method testing can be directly realized under high temperature, saving time and greatly improving the testing efficiency. Description of the Drawings

[0016] Figure 1 It is a schematic cross-sectional structure diagram of the multi-functional piezoelectric performance testing device; 1 - sample to be tested, 2 - support straight rod, 3 - U-shaped support rod, 4 - insulating support table, 5 - support spring, 6 - electromagnetic controller, 7 - vibration source. Detailed Embodiments

[0017] The following describes the multi-functional piezoelectric performance testing device of the present invention that can realize the conversion between the free vibration state and the clamped vibration state.

[0018] The multi-functional piezoelectric performance testing device can be used for samples to be tested with different sizes and shapes. In a specific example, the thickness of the sample to be tested is 0.5 - 2 mm, and the diameter is 10 - 20 mm.

[0019] The multi-functional piezoelectric performance testing device includes a U-shaped support rod. The U-shaped support rod has a long rod and a short rod. The sample to be tested is clamped between the short rod of the U-shaped support rod and the support straight rod. Due to the fixing effect of the through hole and the elastic force of the support spring, the U-shaped support rod can move in the vertical direction. Therefore, by controlling the elastic displacement of the support spring, the position of the U-shaped support rod can be adjusted to adapt to samples to be tested with different sizes. In some embodiments, the telescopic displacement range of the support spring is adjustable between 0 - 5 mm.

[0020] Preferably, the end of the short rod of the U-shaped support rod is hemispherical. This can better clamp the sample to be tested.

[0021] The long rod passes through the through hole of the insulating support table and is connected to the support spring. That is, directly forming a through hole on the insulating support table enables the long rod to pass through the through hole and be connected to the support spring. In some technical solutions, the insulating support table is provided with an installation groove, and the installation groove communicates with the limiting groove on the insulating support table to form a through hole. Thereby, the U-shaped support rod is connected to the support spring through the installation groove and the limiting groove.

[0022] The long rod and the short rod of the U-shaped support rod can be designed in a segmented manner by mechanical connection, or can be integrally configured. Preferably, the U-shaped support rod is integrally formed.

[0023] The end of the supporting straight rod relatively far from the sample to be measured passes through the through hole of the insulating support platform and is connected to the vibration source. In some technical solutions, the insulating support platform is provided with a mounting groove, and the mounting groove communicates with the limiting groove on the insulating support platform to form a through hole. Thus, the supporting straight rod is connected to the vibration source through the mounting groove and the limiting groove.

[0024] The central lines of the supporting straight rod and the short rod of the U-shaped supporting rod are the same straight line. In this way, the sample to be measured can be stably clamped to facilitate improving the accuracy of the test results.

[0025] For the high-temperature piezoelectric performance test environment of the piezoelectric material, the materials of the short rod of the U-shaped supporting rod and the supporting straight rod are preferably high-temperature resistant materials, such as metal materials. As an example, Inconel 718 superalloy material with excellent machining performance and strong oxidation resistance is selected. The above materials can meet the usage requirements of the test device in a high-temperature environment (such as 600 °C).

[0026] The multifunctional piezoelectric performance test device further includes an electromagnetic controller. The conversion between the free vibration state and the clamped vibration state of the sample to be measured is realized by opening or closing the electromagnetic controller. When the electromagnetic controller switch is turned on, the long rod of the U-shaped supporting rod is locked by the magnetic force generated by the electromagnetic controller, the whole U-shaped supporting rod is fixed, and the sample to be measured is in the clamped state through the connection between the supporting straight rod and the vibration source. That is, when the electromagnetic controller is in the open mode, the electromagnetic controller can lock the long rod of the U-shaped supporting rod and keep the U-shaped supporting rod fixed and stationary. By adjusting the amplitude and frequency of the vibration source, etc., the quasi-static piezoelectric coefficient d of the piezoelectric ceramic material in the clamped vibration state 33 is measured.

[0027] Adjusting the frequency and dynamic output of the vibration source will change the dynamic clamping force of the sample to be measured. In some embodiments, the vibration source has an output with a frequency of 30 Hz to 300 Hz. At this time, according to the principle of the piezoelectric effect, the dynamic clamping force of the sample to be measured is 0.05 to 0.5 N.

[0028] When the electromagnetic controller switch is turned off, no magnetic force is generated, the long rod end of the U-shaped supporting rod is not locked, and it can freely expand and contract up and down, being in a free state. The elastic contraction of the supporting spring makes the end of the short rod of the U-shaped supporting rod contact the sample to be measured without applying a clamping force. The weight of the supporting spring and the U-shaped supporting rod should be matched. When in the free vibration state, the appropriate supporting spring makes the hemispherical end of the U-shaped supporting rod contact the sample to be measured but does not apply a clamping force. In this mode, the vibration source does not work and has no output, and the sample to be measured is in the free vibration state.

[0029] The U-shaped supporting rod and the supporting straight rod are respectively in contact with the two surfaces of the sample to be measured, and correspondingly with the piezoelectric coefficient d 33The measuring instrument or impedance analyzer together form a complete test circuit. Therefore, the U-shaped support rod and the support straight rod are part of the piezoelectric performance test circuit and also have electrode functions. For example, when the sample to be tested is in a free vibration state, the electrode is connected to the impedance analyzer, and an alternating current electric field signal is applied to test the performance parameters of the sample to be tested of the piezoelectric ceramic material in the free vibration state. The performance parameters include but are not limited to the electromechanical coupling coefficient kt, the electromechanical coupling coefficient kp, etc.

[0030] The following further describes in detail the multifunctional piezoelectric performance test device capable of realizing the conversion between free and clamped vibrations according to the present invention with reference to the accompanying drawings.

[0031] As Figure 1 shown, the insulating support table 4 is provided with two installation grooves and corresponding limit grooves. The installation groove and the corresponding limit groove communicate with each other to form a through hole. The long rod of the U-shaped support rod 3 is connected to the corresponding limit groove and the support spring 5 through one of the installation grooves. The sample to be tested 1 is clamped between the hemispherical end of the short rod of the U-shaped support rod 3 and the hemispherical end of the support straight rod 2. The other end of the support straight rod 2 passes through the other installation groove and is connected to the corresponding limit groove and the vibration source 7.

[0032] By adjusting the mode of the electromagnetic controller 6, the position of the U-shaped support rod 3 is adjusted to realize the conversion of the sample to be tested between the free vibration state and the clamped vibration state. When the switch of the electromagnetic controller is in the open position, the magnetic force generated by the electromagnetic controller 6 locks the long rod of the U-shaped support rod 3, and the entire U-shaped support rod 3 is fixed. The sample to be tested is in the clamped vibration state through the connection between the support straight rod 2 and the vibration source 7. The support straight rod 2 and the U-shaped support rod 3 that act as electrodes are connected to the externally applied piezoelectric coefficient d 33 measuring instrument to form a test circuit in the clamped vibration state. By adjusting the amplitude and frequency of the vibration source, etc., the quasi-static piezoelectric coefficient d of the sample to be tested in the clamped vibration state is measured. 33 is measured.

[0033] When the switch of the electromagnetic controller is in the closed position, no magnetic force is generated, the long rod end of the U-shaped support rod 3 is not locked, and it can freely expand and contract up and down, being in a free state. The appropriate support spring 5 makes the hemispherical end of the U-shaped support rod 3 contact the sample to be tested but does not apply a clamping force. At this time, the vibration source does not work and has no output, and the sample to be tested is in a free state. The support straight rod 2 and the U-shaped support rod 3 that act as electrodes are connected to the externally applied impedance analyzer to form a test circuit in the free vibration state, and an alternating current electric field signal is applied to measure the electromechanical coupling coefficients (Kt, Kp, etc.) in the free vibration state.

[0034] Although the above embodiments of the present invention have been described, the present invention is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Those of ordinary skill in the art can also make many forms under the inspiration of this specification and without departing from the scope protected by the claims of the present invention, and all of these fall within the scope of protection of the present invention.

Claims

1. A multifunctional piezoelectric performance testing device, characterized in that, It includes a U-shaped support rod, a support straight rod, an insulating support platform and an electromagnetic controller; the U-shaped support rod has a long rod and a short rod, the long rod passes through the through hole of the insulating support platform and is connected to the support spring, and one of the ends of the short rod and the support straight rod clamps the sample to be tested; the materials of the short rod of the U-shaped support rod and the support straight rod are metal materials; the other end of the support straight rod relatively far from the sample to be tested passes through the through hole of the insulating support platform and is connected to the vibration source; the conversion between the free vibration state and the clamped vibration state of the sample to be tested is realized by turning on or off the electromagnetic controller; when the electromagnetic controller switch is turned on, the magnetic force generated by the electromagnetic controller makes the long rod of the U-shaped support rod in a locked state, and the sample to be tested is in the clamped vibration state through the connection between the support straight rod and the vibration source; when the electromagnetic controller switch is turned off, the electromagnetic controller does not generate magnetic force, the long rod of the U-shaped support rod is in a free telescopic state, so the end of the short rod of the U-shaped support rod contacts the sample to be tested without applying a clamping force, making the sample to be tested in the free vibration state.

2. The multifunctional piezoelectric property testing device according to claim 1, wherein The center lines of the support straight rod and the short rod of the U-shaped support rod are the same straight line.

3. The multifunctional piezoelectric property testing device according to claim 1 or 2, characterized in that, The end of the short rod of the U-shaped support rod and the end of the support straight rod in contact with the sample to be tested are both hemispherical.

4. The multifunctional piezoelectric property testing device according to claim 1, characterized in that The quasi-static parameters measured when the sample to be tested is in the clamped vibration state include the piezoelectric coefficient.

5. The multifunctional piezoelectric property testing device according to claim 1, characterized in that, The dynamic resonance parameters measured when the sample to be tested is in the free vibration state include the electromechanical coupling coefficients Kt and / or Kp.

6. The multifunctional piezoelectric property testing device according to claim 1, characterized in that The telescopic displacement of the support spring is adjustable between 0 - 5 cm.

7. The multifunctional piezoelectric property testing device according to claim 1, characterized in that The vibration source has an output with a frequency of 30 Hz to 300 Hz and a pressure of 0.05 N to 0.5 N.

8. The multifunctional piezoelectric property testing device according to claim 1, characterized in that The U-shaped support rod and the support straight rod also act as electrodes at the same time.

9. The multifunctional piezoelectric property testing device according to claim 1, wherein, The insulating support platform is provided with a mounting groove, and the mounting groove communicates with the limiting groove on the insulating support platform to form a through hole, and the U-shaped support rod is connected to the support spring through the mounting groove and the limiting groove.

10. The multifunctional piezoelectric property testing device according to claim 1, wherein The insulating support platform is provided with a mounting groove, and the mounting groove communicates with the limiting groove on the insulating support platform to form a through hole, and the support straight rod is connected to the vibration source through the mounting groove and the limiting groove.

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