CN210243687U

CN210243687U - Universal measuring clamp for measuring transverse piezoelectric constant of piezoelectric material

Info

Publication number: CN210243687U
Application number: CN201920550643.1U
Authority: CN
Inventors: Chao Pan; 潘潮
Original assignee: Institute of Acoustics CAS
Current assignee: Institute of Acoustics CAS
Priority date: 2019-04-22
Filing date: 2019-04-22
Publication date: 2020-04-03
Anticipated expiration: 2029-04-22

Abstract

The utility model relates to a piezoelectric material measuring equipment technical field, concretely relates to a general measurement anchor clamps for measuring piezoelectric material's horizontal piezoelectric constant, it includes: the device comprises a stress application probe mechanism, a first transverse test probe mechanism, a second transverse test probe mechanism, a sliding track (11), an angle-adjustable base (9) and a circular truncated cone base (10); a round table base (10) is arranged on the angle-adjustable base (9), and a second transverse test probe mechanism is arranged on a vertical through screw hole on the sliding track (11); the first transverse test probe mechanism is aligned to the middle position of the second transverse test probe mechanism and is oppositely arranged, and the first transverse test probe mechanism and the second transverse test probe mechanism are respectively abutted against two opposite sides with electrode surfaces of a piezoelectric sample (16) to be tested; the stress application probe mechanism is arranged on the first transverse test probe mechanism; the piezoelectric sample (16) to be tested is arranged on the sliding track (11), and the stress application probe mechanism is positioned above the piezoelectric sample (16) to be tested.

Description

Universal measuring clamp for measuring transverse piezoelectric constant of piezoelectric material

Technical Field

The utility model belongs to the technical field of piezoelectric material measuring equipment, concretely relates to a general measurement anchor clamps for measuring piezoelectric material's horizontal piezoelectric constant.

Background

The piezoelectric constant is an important parameter for characterizing the piezoelectric performance of a piezoelectric material, and mainly comprises: longitudinal direction d₃₃Piezoelectric strain constant (d for short)₃₃Piezoelectric constant), transverse direction d₃₁Piezoelectric strain constant (d for short)₃₁Piezoelectric constant) and tangential d₁₅Piezoelectric strain constant (d for short)₁₅Piezoelectric constant). In the field of functional materials, the discipline of piezoelectric materials, d represents a piezoelectric constant; the subscripts represent directions, wherein the first subscript represents a direction in which piezoelectric charges are generated, and the second subscript represents a direction in which force is applied, wherein "1" represents an x-direction, "2" represents a y-direction, and "3" represents a z-direction, and the piezoelectric constant in any direction can be measured by using the piezoelectric effect of the piezoelectric material itself, that is, by measuring the piezoelectric charges generated in a specific direction due to the piezoelectric effect by applying a force in a specific direction.

For d₃₃The measurement of piezoelectric constant is easy to realize because the direction of force application is same as that of measuring piezoelectric charge, and the force application probe and test probe are shared, so that at present, the most used piezoelectric constant measuring instrument in industry is quasi-static d₃₃And (7) a measuring instrument. Wherein d is₃₁Although the piezoelectric constant is also important in the research and application of piezoelectric materials, the stress application probe and the test probe cannot be shared and must be separated because the stress application direction is vertical to the measurement direction in the measurement process, so that the test difficulty is increased; thus, d can be measured simultaneously₃₃Piezoelectric constant and d₃₁Quasi-static d of piezoelectric constant₃₃/d₃₁The price of the measuring instrument is often higher than that of the quasi-static d with single performance₃₃The price of the measuring instrument is several times, and the cost is very high; and the higher-price quasi-static d widely used in the industry at present₃₃/d₃₁In the measuring instrument, for two samples with different shapes of sheet and round tube, the respective d is measured₃₁When the piezoelectric constant is high, the whole or part of the measuring jig is usually replaced. Therefore, the existing measuring clamp has the defects of high manufacturing cost, poor applicability, complex operation and incapability of meeting the requirement of testing accuracy of piezoelectric samples with different shapes₃₁And (4) measuring a piezoelectric constant.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a for solving current measuring fixture and have above-mentioned defect, the utility model provides a general measuring fixture for measuring piezoelectric material's transverse piezoelectric constant is at current quasi-static d₃₃D of piezoelectric material measured on measuring instrument₃₁Piezoelectric constant by which quasi-static d can be measured₃₃On the measuring instrument for measuring d₃₃The longitudinal alternating force provided by the piezoelectric constant being a measure d₃₁The required transverse alternating force of the piezoelectric constant is separated out, the test probe is changed from the vertical direction to the horizontal direction by rotating 90 degrees, and then quasi-static d is utilized₃₃Current test function of the measuring instrument is obtained d₃₁Measuring the result so that a quasi-static d₃₃The measuring instrument has d₃₃Piezoelectric constant and d₃₁Piezoelectric constant and two test functions. Meanwhile, the universal measuring clamp has wider application range and can be used for the sheet-shaped piezoelectric material d₃₁The measurement of the piezoelectric constant can also be used for the piezoelectric material d with the circular tube-shaped structure₃₁The piezoelectric constant is measured, so that the cost is saved; in addition, the universal measuring jig measures d of the piezoelectric material sample₃₁Piezoelectric constant, quasi-static d commonly used in the market₃₁Compared with the measuring instrument, the measuring instrument has the advantages of simple operation, simple structure and reliable measuring result.

In order to achieve the above object, the present invention provides a general measuring jig for measuring a transverse piezoelectric constant of a piezoelectric material, including: the device comprises a stress application probe mechanism, a first transverse test probe mechanism, a second transverse test probe mechanism, a sliding track 11, an angle-adjustable base 9 and a circular truncated cone base 10;

a circular table base 10 is installed on the angle-adjustable base 9, a radially through groove is formed in the table top of the circular table base 10, a sliding rail 11 is embedded in the groove, a vertical through screw hole is formed in the position 1/3 close to the end part of the sliding rail 11, and a second transverse test probe mechanism is installed on the vertical through screw hole; the first transverse test probe mechanism moves vertically and horizontally and, in use, will moveThe second transverse test probe mechanism is aligned to the middle position of the second transverse test probe mechanism and is oppositely arranged; the stress application probe mechanism is arranged on the first transverse test probe mechanism and is connected with the first transverse test probe mechanism; the piezoelectric sample 16 to be tested is placed on the sliding rail 11 on the circular table base 10, two sides of the piezoelectric sample 16 to be tested are supported by the first transverse test probe mechanism and the second transverse test probe mechanism, namely the piezoelectric sample 16 to be tested is positioned between the first transverse test probe mechanism and the second transverse test probe mechanism, the two opposite sides of the piezoelectric sample 16 to be tested are provided with electrode surfaces, the first transverse test probe mechanism and the second transverse test probe mechanism respectively and correspondingly abut against the two opposite sides with the electrode surfaces of the piezoelectric sample 16 to be tested and are used for measuring the transverse piezoelectric charges of the piezoelectric sample 16 to be tested, the stress application probe mechanism is positioned above the piezoelectric sample 16 to be tested and is used for applying a longitudinal acting force to the piezoelectric sample 16 to be tested, and the transverse piezoelectric constant d of the piezoelectric sample 16 to be tested is obtained according to the longitudinal acting force₃₁。

As an improvement of the above technical means, the force probe mechanism includes: a main bracket 1 and an upper stress application probe 8; the first lateral test probe mechanism comprises: the device comprises a bidirectional movable bracket 3, a positioning probe sleeve 4, an elastic test probe pull handle 5 and an elastic test probe 6;

one end of the main bracket 1 is provided with a through hole in the vertical direction, and the bidirectional movable bracket 3 passes through the through hole; a threaded hole is formed in the horizontal direction of the end part, and the longitudinal positioning wheel 2 is screwed into the threaded hole and used for limiting and fixing the longitudinal movement of the bidirectional movable bracket 3; the lower end of the bidirectional movable support 3 is of a square structure, a horizontal round hole is formed in the left and right directions, and the positioning probe sleeve 4 penetrates into the horizontal round hole; the elastic test probe pull handle 5 and the elastic test probe 6 are connected into a whole, are arranged in the positioning probe sleeve 4 and limit the transverse movement of the elastic test probe 6 through a transverse positioning wheel 7 arranged in front of the square structure; the other end of the main bracket 1 is provided with a through hole in the vertical direction, and the upper stress application probe 8 is arranged at the through hole. Wherein, the elastic test probe pull handle 5 and the elastic test probe 6 can do the transverse reciprocating motion in the positioning probe sleeve 4.

As an improvement of the above technical solution, an upper pressurizing disc 21 is inserted between the upper pressurizing probe 8 and the piezoelectric sample to be measured 16, and is used for generating a longitudinal acting force for measuring the cylindrical piezoelectric sample to be measured 20.

As an improvement of the above technical solution, the second lateral test probe mechanism includes: a test probe positioning knob 12, a test probe 13, a first elastic washer 14 and a second elastic washer 15;

a vertical through screw hole is formed at a position close to the end 1/3 of the sliding rail 11, the test probe 13 is installed on the vertical through screw hole, and a first elastic gasket 14 and a second elastic gasket 15 are respectively and correspondingly installed at two ends of the test probe 13; the test probe 13 is provided with a test probe positioning knob 12 for defining and fixing the position of the test probe 13. Wherein the sliding track 11 and the test probe 13 can be slid laterally within the groove and locked in movement by screwing or unscrewing the test probe positioning knob 12.

As one improvement of the above technical solution, the test probe 13 is a circular tube structure; the first elastic washer 14 and the second elastic washer 15 are both circular ring structures.

As an improvement of the above technical solution, the measuring jig further includes: d₃₃A measuring head 17 and an adjusting hand wheel 18; the angle-adjustable base 9 is arranged at d through a consolidation screw at the bottom₃₃On the measuring head 17, an adjusting hand wheel 18 is arranged on d₃₃And the measuring head 17 is used for adjusting the distance between the piezoelectric sample 16 to be measured and the force application probe 8, and ensuring that the force application probe 8 is lightly pressed on the piezoelectric sample 16 to be measured.

The utility model discloses compare in prior art's beneficial effect and lie in:

the test probe and the upward force application probe in the test fixture of the utility model not only have flexible longitudinal and horizontal position adjusting functions, but also retain the original electrical connection performance; by rotating the circular truncated cone base clockwise and rotating the angle-adjustable base anticlockwise, the sliding rail can be positioned at any position, and the sliding rail is ensured to be aligned with the elastic test probe; the electrode surface of one side of the sheet-shaped sample to be tested is in line contact with the electrode surface of the other side of the sheet-shaped sample to be tested through a test probeThe elastic test probe is propped against to form point contact, so that the piezoelectric sample to be tested can be stably erected on the table top of the circular table base, meanwhile, the piezoelectric sample to be tested is propped against by the upper stress application probe, the first transverse test probe mechanism and the second transverse test probe mechanism, and the transverse d of the sample to be tested is realized according to the applied longitudinal acting force and the measured transverse piezoelectric charge₃₁And (4) measuring a piezoelectric constant.

Drawings

Fig. 1 is a schematic structural diagram of a general measuring jig for measuring a transverse piezoelectric constant of a piezoelectric material according to the present invention;

fig. 2 is a front view of a general measuring jig for measuring a transverse piezoelectric constant of a piezoelectric material according to the present invention;

FIG. 3 shows a universal measuring fixture for measuring transverse piezoelectric constant of piezoelectric material, which is installed at d₃₃A schematic of the structure on the measuring head;

FIG. 4 shows a general measuring fixture for measuring transverse piezoelectric constant of piezoelectric material, which is installed at d₃₃A front view on the measuring head;

fig. 5 is a schematic structural diagram of the utility model of a universal measuring fixture for measuring transverse piezoelectric constant of piezoelectric material for measuring a rectangular piezoelectric sample to be measured;

fig. 6 is a schematic structural diagram of the utility model of a general measuring fixture for measuring transverse piezoelectric constant of piezoelectric material measuring a square piezoelectric sample to be measured;

fig. 7 is a schematic structural diagram of the utility model discloses a general measurement fixture for measuring transverse piezoelectric constant of piezoelectric material measures the round tubular piezoelectric sample that awaits measuring.

Reference numerals:

1. main support 2, longitudinal positioning wheel 3, bidirectional movable support

4. Positioning probe sleeve 5, elastic test probe pull handle 6 and elastic test probe

7. Transverse positioning wheel 8, upper stress application probe 9 and angle-adjustable base

10. Round platform base 11, sliding rail 12, test probe location knob

13. Test probe 14, first elastic washer 15, second elastic washer

16. Piezoelectric test piece 17, d to be tested₃₃Measuring head 18 and adjusting hand wheel

19. Cube piezoelectric sample 20 to be tested, round tube piezoelectric sample 21 to be tested, and upper pressurizing disc

Detailed Description

The invention will now be further described with reference to the accompanying drawings.

As shown in fig. 1 and 2, the utility model provides a general measurement anchor clamps for measuring transverse piezoelectric constant of piezoelectric material, it includes: the device comprises a stress application probe mechanism, a first transverse test probe mechanism, a second transverse test probe mechanism, a sliding track 11, an angle-adjustable base 9 and a circular truncated cone base 10;

as shown in fig. 3 and 4, the bottom of the adjustable angle base 9 is fixed with a screw for installing d₃₃A measuring head 17; the angle-adjustable base 9 is provided with a circular truncated cone base 10, the table top of the circular truncated cone base 10 is provided with a radially through groove, a sliding rail 11 is embedded in the groove, a vertical through screw hole is formed at a position close to the end 1/3 of the sliding rail 11, and a second transverse test probe mechanism is arranged on the vertical through screw hole; the first transverse test probe mechanism moves along the vertical and horizontal directions, and is aligned to the middle position of the second transverse test probe mechanism and oppositely arranged when in use; the stress application probe mechanism is arranged on the first transverse test probe mechanism and is connected with the first transverse test probe mechanism; the piezoelectric sample 16 to be tested is placed on the sliding track 11 on the circular table base 10, and two sides are supported by the first transverse test probe mechanism and the second transverse test probe mechanism, namely, the piezoelectric sample 16 to be tested is positioned between the first transverse test probe mechanism and the second transverse test probe mechanism, electrode surfaces are arranged on two opposite sides of the piezoelectric sample 16 to be tested, the first transverse test probe mechanism and the second transverse test probe mechanism respectively and correspondingly abut against two opposite sides with the electrode surfaces of the piezoelectric sample 16 to be tested,the stress application probe mechanism is positioned above the piezoelectric sample 16 to be measured and is used for applying a longitudinal acting force on the piezoelectric sample 16 to be measured and obtaining a transverse piezoelectric constant d of the piezoelectric sample 16 to be measured according to the applied longitudinal acting force and the measured transverse piezoelectric charge₃₁。

one end of the main bracket 1 is provided with a through hole in the vertical direction, and the bidirectional movable bracket 3 passes through the through hole; a threaded hole is formed in the horizontal direction of the end part, and the longitudinal positioning wheel 2 is screwed into the threaded hole and used for limiting and fixing the longitudinal movement of the bidirectional movable bracket 3; one end of the bidirectional movable support 3 is of a square structure, a horizontal round hole is formed in the left and right directions, and the positioning probe sleeve 4 penetrates into the horizontal round hole; the elastic test probe pull handle 5 and the elastic test probe 6 are connected into a whole, are arranged in the positioning probe sleeve 4 and limit the transverse movement of the elastic test probe 6 through a transverse positioning wheel 7 arranged in front of the square structure; the other end of the main bracket 1 is provided with a through hole in the vertical direction, and the upper stress application probe 8 is arranged at the through hole. Wherein, the elastic test probe pull handle 5 and the elastic test probe 6 perform transverse reciprocating motion in the positioning probe sleeve 4.

As shown in fig. 1, when the elastic test probe pull handle 5 is pulled rightwards, the elastic test probe 6 moves rightwards together, and after the elastic test probe pull handle 5 is released, the elastic test probe 6 rebounds to the original position, namely, the reset is completed; the upper stress application probe 8 is arranged at a through hole arranged at the left end of the main bracket 1, namely, the combined probe mechanism is arranged and fixed at a quasi-static state d₃₃The original quasi-static d is measured by the position of the stress application test probe on the measuring head of the measuring instrument₃₃The common probe for the stress application test of the measuring instrument is divided into two independent functions of longitudinal stress application and transverse test electrodes. The force application probe 8 not only applies a longitudinal acting force to the piezoelectric sample to be tested,the device also plays a role in mounting and fixing a combined probe mechanism of a suspension structure, namely the longitudinal stress application function of the original stress application probe is unchanged, and meanwhile, the circuit connection attribute of the 'common grounding end' of the original measuring probe is also reserved through the connection of the main bracket 1, the longitudinal positioning wheel 2, the bidirectional movable bracket 3, the positioning probe sleeve 4, the elastic testing probe pull handle 5, the elastic testing probe 6 and the transverse positioning wheel 7.

As an improvement of the above technical solution, an upper pressurizing disc 21 is inserted between the upper pressurizing probe 8 and the piezoelectric sample to be measured 16, and is used for generating a longitudinal acting force applied to the circular tube-shaped piezoelectric sample to be measured 20.

a vertical through screw hole is formed at a position close to the end 1/3 of the sliding rail 11, the test probe 13 is installed on the vertical through screw hole, and a first elastic gasket 14 and a second elastic gasket 15 are respectively and correspondingly installed at two ends of the test probe 13; the test probe 13 is provided with a test probe positioning knob 12 for defining and fixing the position of the test probe 13. As shown in fig. 1, wherein a first elastic washer 14 is disposed between the upper end of the test probe 13 and the test probe positioning knob 12, and a second elastic washer 15 is disposed between the test probe 13 and the sliding rail 11, since the sliding rail 11 is mounted in the groove of the circular table base 10, the circular table base 10 is mounted on the angle-adjustable base 9, and the bottom of the angle-adjustable base 9 is fixed with a screw rod mounted on d₃₃On the measuring head 17; d₃₃When the measuring head 17 provides a longitudinal alternating action to generate vibration, the first elastic washer 14 and the second elastic washer 15 can effectively reduce an additional tangential force between the second testing probe and the side surface of the piezoelectric sample 16 to be tested during measurement, so that the measurement error caused by the additional tangential force is reduced. Wherein the sliding track 11 can be slid laterally within the groove and locked in its movement while fixing the position of the test probe 13 by screwing or unscrewing the test probe positioning knob 12.

As one improvement of the above technical solution, as shown in fig. 2, 3 and 4, the sliding rail 11 is embedded in the groove, the upper surface of the sliding rail is flush with the table top of the circular table base 10, and the test probe 13 mounted on the sliding rail 11 is arranged opposite to the elastic test probe 6, and the included angle between the two is 0 degree.

As one improvement of the above technical solution, as shown in fig. 1 and 3, the measuring jig further includes: d₃₃A measuring head 17 and an adjusting hand wheel 18; d₃₃A measuring head 17 is arranged on a consolidation screw rod at the bottom of the angle-adjustable base 9, and an adjusting hand wheel 18 is arranged at d₃₃And the measuring head 17 is used for adjusting the distance between the piezoelectric sample 16 to be measured and the force application probe 8, and ensuring that the force application probe 8 is lightly pressed on the piezoelectric sample 16 to be measured.

The method comprises the steps of placing a piezoelectric sample 16 to be tested on a sliding rail 11 on the table top of a circular table base 10 and between a testing probe 13 and an elastic testing probe 6, and placing an upper stress probe 8 above the piezoelectric sample 16 to be tested, specifically, as shown in fig. 5 and 6, placing the piezoelectric sample 16 to be tested between the testing probe 13 and the elastic testing probe 6, moving the sliding rail 11 and the testing probe 13 to enable the two to gradually approach the elastic testing probe 6, and ensuring that electrode surfaces on two sides of the piezoelectric sample 16 to be tested are respectively and correspondingly attached to the testing probe 13 and the elastic testing probe 6 to form electric contact for receiving generated piezoelectric charges, wherein the upper stress probe 8 is enabled to be abutted to the top of the piezoelectric sample 16 to be tested by adjusting a longitudinal positioning wheel 2 so as to enable the upper stress probe 8 to be longitudinally stressed. According to d₃₁Definition of piezoelectric constant:

wherein D is₃Is a potential shift; e₃Is the electric field strength; t is₁，S₁Stress and strain perpendicular to the polarization direction, respectively;

when the preset longitudinal acting force applied to the piezoelectric sample to be tested is a low-frequency sine wave alternating force, and the frequency of the longitudinal acting force is far lower than the inherent resonant frequency of the piezoelectric sample to be tested, the stress and the strain in the piezoelectric sample to be tested are uniformly distributed, so that the piezoelectric sample to be tested is regarded as quasi-static; based on this, formula (1) can be simplified as:

in the formula (d)₃₁Is the transverse piezoelectric constant; f₁Is d₃₃The low-frequency alternating force provided by the measuring head 17 is the longitudinal acting force applied by the force application probe; q₃For the piezoelectric sample to be tested being subjected to F₁When acting force is applied, the self piezoelectric effect generates transverse piezoelectric charge in the direction vertical to the applied force; a is applied stress F₁The stress area acted on the piezoelectric sample to be measured; b is transverse piezoelectric charge Q generated on two side surfaces of the piezoelectric sample to be tested₃The electrode area of (a); k is the ratio of A to B, and k is a quantitative coefficient for a known piezoelectric sample to be measured. Wherein, F₁By d₃₃Obtained by a measuring instrument, Q₃Obtained by the measurement of an elastic test probe and a test probe.

Therefore, according to the formula (2), the transverse piezoelectric constant d of the piezoelectric sample 16 to be measured can be obtained₃₁。

When the piezoelectric sample 16 to be tested is a rectangular piezoelectric sample to be tested, as shown in fig. 5, the rectangular piezoelectric sample to be tested is stood on the sliding track 11 on the circular truncated cone base 10, the test probe positioning knob 12 is unscrewed, the sliding track 11 is moved, the piezoelectric sample 16 to be tested is positioned at the middle position of the circular truncated cone base 10, the test probe positioning knob 12 is screwed, the position of the test probe can be locked, the rectangular piezoelectric test sample to be tested is placed between the test probe 13 and the elastic test probe 6, the bidirectional movable support 3 and the elastic test probe pull handle 5 are adjusted to ensure that the opposite two side surfaces with electrodes of the rectangular piezoelectric test sample to be tested are respectively and correspondingly clung to the test probe 13 and the elastic test probe 6 to form electric contact, and meanwhile, the adjusting hand wheel 18 is adjusted to ensure that the upward force application probe 8 is positioned above the rectangular piezoelectric sample to be tested and slightly presses the rectangular piezoelectric sample to be tested.On the sample, the transverse positioning wheel 7 and the longitudinal positioning wheel 2 are locked, and d is opened₃₃The switch of the measuring instrument applies longitudinal acting force F to the rectangular piezoelectric sample to be measured by the upper stress application probe 8₁Measuring the transverse piezoelectric charge Q of the rectangular piezoelectric test sample to be tested by the test probe 13 and the elastic test probe 6₃Then measuring the stress area A and the electrode area B of the rectangular piezoelectric sample 6 to be measured, and obtaining the transverse piezoelectric constant d by using the formula (2)₃₁。

When the piezoelectric sample to be measured is a square piezoelectric sample to be measured, as shown in fig. 6, for the square piezoelectric sample to be measured 19, since the force-receiving area is the same as the area where the piezoelectric charge is generated, k in the formula (2) is 1; d of the piezoelectric sample to be measured₃₁The piezoelectric constant being a transverse piezoelectric charge Q₃The longitudinal force F exerted by the loading probe 8 with the measuring head 17₁The ratio of (a) to (b).

When the piezoelectric sample to be measured is a circular tube-shaped piezoelectric sample to be measured, as shown in fig. 7, for the circular tube-shaped piezoelectric sample to be measured, a pressurizing disc 21 needs to be additionally arranged between the upward force application probe 8 and the piezoelectric sample 16 to be measured; the upper pressurizing disc 21 is made of hard non-metal materials, the diameter of the upper pressurizing disc is close to that of the circular table base 10, the thickness of the upper pressurizing disc 21 is 3-4mm, and a semicircular pit with the diameter of 2-3mm and the depth of 2mm is machined in the circle center of the upper plane of the upper pressurizing disc 21. The inner side and the outer side of the round tube-shaped piezoelectric sample 20 to be measured are two electrode surfaces with electrodes, the electrode surfaces are round curved surfaces, and the upper end surface and the lower end surface are stress surfaces.

Since the circular tube-shaped piezoelectric sample to be measured 20 is hollow, the upper force application probe 8 needs to apply a longitudinal force to the end face of the circular tube-shaped piezoelectric sample to be measured 20 through the upper pressing disk 21. The specific operation is as follows:

unscrewing the test probe positioning knob 12, placing the round tube-shaped piezoelectric sample to be tested 20 in the middle position of the round platform base 10, keeping the position unchanged, simultaneously adjusting the sliding rail 11 to move rightwards, enabling the test probe 13 to be in contact with the inner tube wall of the round tube-shaped piezoelectric sample to be tested 20, screwing the test probe positioning knob 12, and then placing the upper pressurizing disc 21 in the round tube shape to be testedThe upper end surface of the pressure measuring electric sample 20 is aligned with the semicircular concave pit on the upper pressure disk 21 to the upper force application probe 8, and the position d is adjusted₃₃The adjusting hand wheel 18 on the measuring head 17 presses the upper end face of the round pipe-shaped piezoelectric sample to be tested 20 by the upper pressurizing disc 21, and simultaneously adjusts the bidirectional movable support 3 and the elastic testing probe pull handle 5, so that the elastic testing probe 6 is pressed against the outer pipe wall of the round pipe-shaped piezoelectric sample to be tested 20, the transverse positioning wheel 7 and the longitudinal positioning wheel 2 are screwed, and the positions of the elastic testing probe 6 and the upper stress application probe 8 at the moment are fixed, wherein the outer pipe wall of the round pipe-shaped piezoelectric sample to be tested 20 and the inner pipe wall of the round pipe-shaped piezoelectric sample to be tested 20 are both circular curved surfaces. Is opened at d₃₃Meter switch, d₃₃The measuring head 17 generates low-frequency alternating acting force to apply longitudinal acting force F through the force application probe 8₁Applying the test probe 13 and the elastic test probe 6 on the round tube-shaped piezoelectric sample 20 to be tested to measure the transverse piezoelectric charge Q of the round tube-shaped piezoelectric sample 20 to be tested₃The transverse piezoelectric constant d is obtained by the formula (2)₃₁。

Here, to explain the holding structure of the round-tube-shaped pressure-measured electric sample 20 in measurement, the round-tube-shaped pressure-measured electric sample 20 is shown in fig. 5 as a schematic view of the round-tube-shaped pressure-measured electric sample 20 with a quarter cut away.

Based on this, d of the circular tube-shaped piezoelectric test piece to be measured is calculated by using the formula (2)₃₁The piezoelectric constant, the coefficient k thereof needs to be obtained by formula (3):

wherein a is the outer radius of the round pipe; b is the inner radius of the round tube; h is the height of the circular tube; ln is the natural logarithm.

Wherein, when the test probe 13 is installed, the upper and lower ends are respectively provided with a first elastic gasket 14 and a second elastic gasket 15, when in use, the test probe is in line contact with the electrode surface of the piezoelectric test sample to be tested (the sheet sample is a side surface, and the circular tube sample is an inner circular curved surface), when the end surface (or the horizontal plane) of the piezoelectric test sample to be tested is subjected to a vertical longitudinal force, the first elastic gasket 14 and the second elastic gasket 14 are respectively arranged on the upper end and the lower end of the test probeThe elastic washer 15 plays a role in up-and-down damping on the test probe 13, and reduces the action of external tangential force on a piezoelectric sample to be tested in use, thereby ensuring measurement d₃₁Accuracy of piezoelectric constant.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art will understand that modifications and equivalent substitutions can be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention, and all of them shall fall within the scope of the claims of the present invention.

Claims

1. A universal measuring fixture for measuring the transverse piezoelectric constant of a piezoelectric material, comprising: the device comprises a stress application probe mechanism, a first transverse test probe mechanism, a second transverse test probe mechanism, a sliding track (11), an angle-adjustable base (9) and a circular truncated cone base (10);

a circular table base (10) is mounted on the angle-adjustable base (9), a radially through groove is formed in the table top of the circular table base (10), a sliding rail (11) is embedded in the groove, a vertical through screw hole is formed in the position 1/3 which is away from the end part of the sliding rail (11), and a second transverse test probe mechanism is mounted on the vertical through screw hole; the first transverse test probe mechanism moves along the vertical and horizontal directions and is aligned to the middle position of the second transverse test probe mechanism when in use; the stress application probe mechanism is arranged on the first transverse test probe mechanism and is connected with the first transverse test probe mechanism; the piezoelectric sample (16) to be tested is placed on the sliding rail (11) on the circular table base (10), the first transverse testing probe mechanism and the second transverse testing probe mechanism are respectively abutted to two opposite sides with electrode surfaces of the piezoelectric sample (16) to be tested, and the stress application probe mechanism is located above the piezoelectric sample (16) to be tested.

2. The universal measuring fixture for measuring the transverse piezoelectric constant of a piezoelectric material of claim 1, wherein the force probe mechanism comprises: a main bracket (1) and an upper stress application probe (8); the first lateral test probe mechanism comprises: the device comprises a bidirectional movable support (3), a positioning probe sleeve (4), an elastic test probe pull handle (5) and an elastic test probe (6);

one end of the main bracket (1) is provided with a through hole in the vertical direction, and the bidirectional movable bracket (3) passes through the through hole; a threaded hole is formed in the horizontal direction of the end part, and a longitudinal positioning wheel (2) is screwed into the threaded hole and used for limiting and fixing the longitudinal movement of the bidirectional movable bracket (3); the lower end of the bidirectional movable support (3) is of a square structure, a round hole is formed in the left and right horizontal directions, and the position-adjusting probe sleeve (4) is sleeved in the round hole; the elastic test probe pull handle (5) and the elastic test probe (6) are connected into a whole, are arranged in the positioning probe sleeve (4), and limit the transverse movement of the elastic test probe (6) through a transverse positioning wheel (7) arranged in front of the square structure; the other end of the main bracket (1) is provided with a through hole in the vertical direction, and the upper stress application probe (8) is arranged at the through hole.

3. The universal measuring fixture for measuring transverse piezoelectric constants of piezoelectric materials according to claim 2, characterized in that an upper pressurizing disc (21) is inserted between the upper force probe (8) and the piezoelectric sample to be measured (16) for generating a longitudinal force for measuring the cylindrical piezoelectric sample to be measured (20).

4. The universal measurement fixture for measuring transverse piezoelectric constants of piezoelectric materials of claim 1, wherein the second transverse test probe mechanism comprises: the test probe comprises a test probe positioning knob (12), a test probe (13), a first elastic gasket (14) and a second elastic gasket (15);

a vertical through screw hole is formed at the position 1/3 which is far away from the end part of the sliding track (11), a test probe (13) is arranged on the vertical through screw hole, and a first elastic gasket (14) and a second elastic gasket (15) are respectively and correspondingly arranged at the two ends of the test probe (13); the test probe (13) is provided with a test probe positioning knob (12) for defining and fixing the position of the test probe (13).

5. The universal measuring fixture for measuring transverse piezoelectric constants of piezoelectric materials according to claim 4, characterized in that the test probe (13) is a circular tube-shaped structure; the first elastic washer (14) and the second elastic washer (15) are both of circular ring structures.