Variable-stiffness miniature linear vibration table

Abstract

The invention discloses a variable-stiffness miniature linear vibration table, which comprises a linear vibration table main body, a piezoelectric ceramic seat, a stiffness adjusting screw, a pre-tightening spring gland, a sensor gland, piezoelectric ceramics, a stiffness adjusting buckle, a stiffness adjusting spring, a pre-tightening spring and a sensor, wherein a first side wall of the linear vibration table main body is provided with a first groove, the piezoelectric ceramic is arranged in the first groove, and the piezoelectric ceramic seat is connected with the first groove; a second groove is formed in the second side wall of the linear vibration table body, the pre-tightening spring is arranged in the second groove, and the pre-tightening spring gland is connected with the second groove. The linear vibration table main body is provided with a third groove, the sensor is arranged in the third groove, and the sensor gland is connected with the third groove; threaded holes are formed in the third side wall of the linear vibration table body, and the rigidity adjusting buckles and the rigidity adjusting springs are arranged in the threaded holes. The device is compact in structure, is simple to use, can generate tiny displacement or linear vibration, and is very high in measurement precision.

Description

Technical Field

[0001] The invention belongs to the technical field of vibration measurement, and in particular relates to a variable-rigidity micro-wire vibration table. Background Art

[0002] High-precision inertial devices (such as accelerometers) are mainly used in aerospace and other fields that require precise posture control. By measuring and obtaining accurate data of motion, they provide reliable guarantees for the measurement and control of spacecraft. With the development of technology, the requirements for the accuracy and dynamic performance of vibration measurement are becoming higher and higher. The continuous improvement of the dynamic performance of measuring devices has put forward an urgent need for high-accuracy dynamic calibration. Accurate evaluation of the dynamic performance of inertial devices is of vital importance to ensuring and improving the working stability of aircraft platforms including satellites and the quality of aerospace imaging. Therefore, a vibration table that can generate and measure high-precision vibrations is of great significance.

[0003] Existing vibration tables can be divided into large and micro types. The test object of a large vibration table is generally a large structure. It usually adopts electro-hydraulic, electromagnetic and other driving methods. It is a complex electromechanical coupling system. It has a large scale and mass. It is often fixed in a specific place. The use process is relatively cumbersome, and its huge size makes it impossible to provide extremely small vibrations. Micro vibration tables are used to provide tiny vibrations to cooperate with machine tool processing, sensor calibration, etc. They are usually small in structure and easy to use. However, in order to ensure stable dynamic characteristics within the frequency range of use, the current micro vibration tables generally have a very high first-order fundamental frequency, which leads to extremely high stiffness in the vibration direction of the vibration table. A large driving force is required to drive the vibration table to move. Therefore, large piezoelectric ceramics or motors are often used for driving, which increases the invalid size. In addition, there is also an extremely micro satellite vibration table, which is directly processed by piezoelectric ceramic sheets. This vibration table is usually used for sensor chip calibration. The size is similar to that of the chip and cannot be used for conventional load testing. The above vibration tables all have fixed structures, so they cannot work near their fundamental frequencies. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a variable stiffness micro linear vibration table, which has a compact structure, is easy to use, can produce extremely small displacements or linear vibrations, has high measurement accuracy, and can provide the required micro-level, high-precision vibration environment for the load; and can adjust the connection stiffness of the moving part, change the fundamental frequency of the vibration table, avoid resonance, and adapt to the needs of different vibration conditions.

[0005] The object of the present invention is achieved through the following technical solutions: A variable stiffness micro-wire vibration table, comprising: a wire vibration table body, a piezoelectric ceramic seat, a stiffness adjustment screw, a preload spring cover, a sensor cover, a piezoelectric ceramic, a stiffness adjustment buckle, a stiffness adjustment spring, a preload spring and a sensor; wherein, a first groove is formed on the first side wall of the wire vibration table body, the piezoelectric ceramic is arranged in the first groove, the piezoelectric ceramic seat is connected to the first groove, and the piezoelectric ceramic seat is pressed against the piezoelectric ceramic; a second groove is formed on the second side wall of the wire vibration table body, the preload spring is arranged in the second groove, the preload spring The pre-tensioning spring pressure cover is connected to the second groove, and the pre-tensioning spring pressure cover is pressed against the pre-tensioning spring; wherein the first side wall and the second side wall are opposite to each other; the line vibration table body is provided with a third groove, the sensor is arranged in the third groove, and the sensor pressure cover is connected to the third groove; the third side wall of the line vibration table body is provided with a threaded hole, the stiffness adjustment buckle and the stiffness adjustment spring are both arranged in the threaded hole, and the stiffness adjustment screw pushes the stiffness adjustment buckle into the threaded hole and presses the stiffness adjustment spring; wherein the third side wall is adjacent to the first side wall and the second side wall respectively.

[0006] In the above variable-rigidity micro-wire vibration table, the preload spring generates a preload force to make the piezoelectric ceramic contact with the wire vibration table body.

[0007] In the above-mentioned variable stiffness micro-wire vibration table, the wire vibration table body includes an external installation area, a load installation area and a stiffness adjustment area; wherein the load installation area and the stiffness adjustment area are located inside the external installation area; the load installation area and the stiffness adjustment area are connected, and the load installation area and the stiffness adjustment area are both connected to the external installation area.

[0008] In the above-mentioned variable-rigidity micro-wire vibration table, the external installation area is provided with a third groove, the sensor is arranged in the third groove, and the sensor pressure cover is connected to the third groove.

[0009] In the above-mentioned variable stiffness micro linear vibration table, the side surface of the load installation area corresponding to the sensor cover installation position in the external installation area is the measurement surface, and the sensor measures the measurement surface to obtain the movement of the linear vibration table.

[0010] In the above-mentioned variable-rigidity micro-wire vibration table, after the piezoelectric ceramic is energized, it generates displacement according to the voltage variation law, driving the load installation area of ​​the wire vibration table body to move, thereby generating corresponding vibration.

[0011] In the above-mentioned variable-rigidity micro-wire vibration table, a first groove is formed on the first side wall of the external installation area; a second groove is formed on the second side wall of the external installation area; wherein the first side wall and the second side wall are opposite to each other.

[0012] In the above-mentioned variable stiffness micro-wire vibration table, the stiffness preload force can be changed by rotating the stiffness adjustment screw, thereby adjusting the fundamental frequency of the wire vibration table.

[0013] In the above variable stiffness micro wire vibration table, the piezoelectric ceramic seat is connected to the wire vibration table body by bolts.

[0014] In the above-mentioned variable-rigidity micro-wire vibration table, the preload spring pressure cover is connected to the wire vibration table body by bolts; and the sensor pressure cover is connected to the wire vibration table body by bolts.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The present invention can generate extremely small displacement or vibration and perform high-precision measurement, providing an accurate micro-vibration environment for the load. The extremely low fundamental frequency ensures vibration stability while reducing the driving force requirement;

[0017] (2) The present invention can avoid resonance by adjusting its own fundamental frequency and adapt to various vibration conditions;

[0018] (3) The variable stiffness micro-wire vibration table of the present invention has a simple and compact structure and is easy to transport. It can be flexibly installed in any measurement environment by screws, and can achieve a variety of vibrations and measurement accuracies by combining different piezoelectric ceramics and sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0020] Figure 1 is a schematic diagram of the layout of the vibration sensor provided by an embodiment of the present invention during calibration;

[0021] Figure 2 is a schematic structural diagram of a variable stiffness micro-wire vibration table provided in an embodiment of the present invention;

[0022] Figure 3 It is a cross-sectional view of a variable stiffness micro-wire vibration table provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] Figure 1 This is a schematic diagram of the installation relationship of a variable stiffness micro-wire vibration table of the present invention when calibrating a vibration sensor. The load to be tested is replaced by a block, and the installation is achieved by connecting the screws with the threaded holes in the load installation area of ​​the wire vibration table. During the test, the external voltage is controlled to vibrate the wire vibration table, and the vibration is measured by the wire vibration table's own sensor, and compared with the measurement of the load to be tested to obtain the calibration result.

[0025] Figure 2 is a schematic structural diagram of a variable stiffness micro-wire vibration table provided in an embodiment of the present invention; Figure 3 FIG. 2 is a cross-sectional view of a variable stiffness micro-wire vibration table provided by an embodiment of the present invention. Figure 2 and Figure 3 As shown, the variable stiffness micro wire vibration table comprises: a wire vibration table body 1, a piezoelectric ceramic seat 2, a stiffness adjustment screw 3, a preload spring cover 4, a sensor cover 5, a piezoelectric ceramic 6, a stiffness adjustment buckle 7, a stiffness adjustment spring 8, a preload spring 9 and a sensor 10; wherein, a first groove is provided on the first side wall of the wire vibration table body 1, in which the piezoelectric ceramic 6 is arranged, the piezoelectric ceramic seat 2 is connected to the first groove, and the piezoelectric ceramic seat 2 is pressed against the piezoelectric ceramic 6; a second groove is provided on the second side wall of the wire vibration table body 1, in which the preload spring 9 is arranged, and the preload spring 9 is pressed against the piezoelectric ceramic 6. The tightening spring pressure cover 4 is connected to the second groove, and the pre-tensioning spring pressure cover 4 is pressed against the pre-tensioning spring 9; wherein, the first side wall and the second side wall are opposite; the line vibration table body 1 is provided with a third groove, the sensor 10 is arranged in the third groove, and the sensor pressure cover 5 is connected to the third groove; the third side wall of the line vibration table body 1 is provided with a threaded hole, the stiffness adjustment buckle 7 and the stiffness adjustment spring 8 are both arranged in the threaded hole, and the stiffness adjustment screw 3 pushes the stiffness adjustment buckle 7 into the threaded hole and presses the stiffness adjustment spring 8; wherein, the third side wall is adjacent to the first side wall and the second side wall respectively.

[0026] The preload spring 9 generates a preload force to make the piezoelectric ceramic 6 contact with the wire vibration table body 1 .

[0027] like Figure 2As shown, the linear vibration table body 1 includes an external installation area 11, a load installation area 12 and a stiffness adjustment area 13; wherein the load installation area 12 and the stiffness adjustment area 13 are located inside the external installation area 11; the load installation area 12 and the stiffness adjustment area 13 are connected, and the load installation area 12 and the stiffness adjustment area 13 are both connected to the external installation area 11.

[0028] The external installation area 11 is provided with a third groove, the sensor 10 is arranged in the third groove, and the sensor gland 5 is connected to the third groove.

[0029] The side surface of the load installation area corresponding to the sensor cover installation position in the external installation area is the measuring surface, and the sensor measures the measuring surface to obtain the movement of the linear vibration table.

[0030] After the piezoelectric ceramic 6 is energized, it generates displacement according to the voltage variation law, driving the load installation area 12 of the linear vibration table body 1 to move, thereby generating corresponding vibration.

[0031] A first groove is formed on the first side wall of the external installation area 11 ; a second groove is formed on the second side wall of the external installation area 11 ; wherein the first side wall and the second side wall are opposite to each other.

[0032] By rotating the stiffness adjustment screw 3, the stiffness preload force can be changed and the fundamental frequency of the linear vibration table can be adjusted.

[0033] The piezoelectric ceramic seat 2 is connected to the main body 1 of the linear vibration platform by bolts. The preload spring pressure cover 4 is connected to the main body 1 of the linear vibration platform by bolts; and the sensor pressure cover 5 is connected to the main body 1 of the linear vibration platform by bolts.

[0034] The piezoelectric ceramic seat is connected to the main body of the line vibration table by bolts, and the piezoelectric ceramic is installed in the main body of the line vibration table; the preload spring cover is connected to the main body of the line vibration table by bolts, and the preload spring is pressed in to generate a preload force to ensure that the piezoelectric ceramic is in contact with the main body of the line vibration table; the sensor cover is fixed to the main body of the line vibration table by bolts to measure the vibration of the line vibration table in real time; the stiffness adjustment screw pushes the stiffness adjustment buckle into the threaded hole and compresses the stiffness adjustment spring. By rotating the stiffness adjustment screw, the stiffness preload force can be changed to adjust the fundamental frequency of the line vibration table.

[0035] The fundamental frequency of the variable stiffness micro linear vibration table in the vibration direction is much lower than the fundamental frequencies in other directions, which makes it easy to produce unidirectional deformation, and at the same time has sufficient support stiffness to install the load. By controlling the input voltage, it can produce extremely small displacement or linear vibration in the expansion and contraction direction of the piezoelectric ceramic, and can accurately measure the displacement or vibration through the sensor, thereby providing accurate and small displacement or vibration for the load.

[0036] Within the permitted range of the installation space, different types of piezoelectric ceramics can be selected for the variable stiffness micro linear vibration table, so that the linear vibration table has different strokes and displacement accuracies.

[0037] The main body of the line vibration table mainly includes the external installation area, the load installation area and the stiffness adjustment area. The external installation area is used to fix the load installation area, the load installation area is used to install the load that requires a vibration environment, and the stiffness adjustment area can adjust the fundamental frequency of the micro vibration table. On the top surface of the main body of the line vibration table, the load installation area is slightly higher than the rest of the area, and on the bottom surface, the external installation area is slightly higher than the rest of the area, ensuring that the load installation area and the stiffness adjustment area will not contact other areas and the external environment when moving.

[0038] The vibration table body is integrally formed, has no other connecting parts, and has a compact structure; the three installation areas are connected by a thin sheet structure to ensure that the linear vibration table is easy to displace or vibrate, and to adjust the stiffness, and has sufficient support stiffness to install the load.

[0039] The side of the load installation area corresponding to the sensor cover installation in the external installation area of ​​the vibration table body is the measuring surface. The movement of the linear vibration table is obtained by measuring the measuring surface with the sensor, and its accuracy depends on the accuracy of the sensor.

[0040] The selection of sensors is highly flexible. A variety of sensors can be matched at the sensor installation site through tooling to achieve different measurement accuracies. While ensuring accuracy, the sensor does not have to be connected to the main body of the linear vibration table, and an external sensor can be used.

[0041] The stiffness adjustment area includes an inner and outer layer, which not only releases the degree of freedom of the load installation area and reduces the fundamental frequency of the linear vibration table in the direction of movement, but also avoids shear load on the stiffness adjustment screw. By generating pressure on the stiffness adjustment area through the stiffness adjustment screw, and then generating pressure on the connection with the load installation area, the fundamental frequency of the load installation area can be changed to avoid resonance when the required vibration is generated.

[0042] The stiffness adjustment screw presses the stiffness adjustment spring by pressing against the stiffness adjustment buckle, thereby generating pressure on the stiffness adjustment area and avoiding wear caused by direct contact with the area.

[0043] After the piezoelectric ceramic 6 is energized, it will generate displacement according to the voltage change law, driving the load installation area of ​​the linear vibration table body 1 to move, thereby generating corresponding vibration. The sensor 10 obtains vibration information by measuring the measuring surface on the side of the load installation area, and compares it with the measurement of the load to be measured to obtain a calibration result.

[0044] The variable stiffness micro-wire vibration table has the characteristics of compact structure, convenient transportation, flexible installation and simple use. The installation position can be adjusted according to needs to provide a high-precision micro-vibration environment under different conditions.

[0045] This embodiment can generate extremely small displacement or vibration and perform high-precision measurement, providing an accurate micro-vibration environment for the load. The extremely low fundamental frequency ensures vibration stability while reducing the driving force requirement. This embodiment can avoid resonance by adjusting its own fundamental frequency and adapt to various vibration conditions. The variable stiffness micro-wire vibration table of this embodiment has a simple and compact structure and is easy to transport. It can be flexibly installed in any measurement environment by screws, and can achieve a variety of vibration and measurement accuracies in combination with different piezoelectric ceramics and sensors.

[0046] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A variable stiffness micro-wire vibration table, characterized in that include: A linear vibration table body (1), a piezoelectric ceramic seat (2), a stiffness adjustment screw (3), a preload spring pressure cover (4), a sensor pressure cover (5), a piezoelectric ceramic (6), a stiffness adjustment buckle (7), a stiffness adjustment spring (8), a preload spring (9) and a sensor (10); wherein, A first groove is formed on the first side wall of the linear vibration table body (1), the piezoelectric ceramic (6) is arranged in the first groove, the piezoelectric ceramic seat (2) is connected to the first groove, and the piezoelectric ceramic seat (2) and the piezoelectric ceramic (6) are pressed against each other; A second groove is formed on the second side wall of the linear vibration table body (1), the preload spring (9) is arranged in the second groove, the preload spring pressure cover (4) is connected to the second groove, and the preload spring pressure cover (4) is pressed against the preload spring (9); wherein the first side wall and the second side wall are opposite to each other; The linear vibration table body (1) is provided with a third groove, the sensor (10) is arranged in the third groove, and the sensor gland (5) is connected to the third groove; A threaded hole is provided on the third side wall of the linear vibration table body (1), the stiffness adjustment buckle (7) and the stiffness adjustment spring (8) are both arranged in the threaded hole, and the stiffness adjustment screw (3) pushes the stiffness adjustment buckle (7) into the threaded hole and presses the stiffness adjustment spring (8); wherein the third side wall is adjacent to the first side wall and the second side wall respectively.

2. The variable stiffness micro-wire vibration table according to claim 1, characterized in that: The preload spring (9) generates a preload force so that the piezoelectric ceramic (6) is in contact with the wire vibration table body (1).

3. The variable stiffness micro-wire vibration table according to claim 1, characterized in that: The linear vibration table body (1) comprises an external installation area (11), a load installation area (12) and a stiffness adjustment area (13); wherein: The load installation area (12) and the stiffness adjustment area (13) are located inside the external installation area (11); The load installation area (12) and the stiffness adjustment area (13) are connected, and both the load installation area (12) and the stiffness adjustment area (13) are connected to the external installation area (11).

4. The variable stiffness micro-wire vibration table according to claim 3, characterized in that: The external installation area (11) is provided with a third groove, the sensor (10) is arranged in the third groove, and the sensor pressure cover (5) is connected to the third groove.

5. The variable stiffness micro-wire vibration table according to claim 4, characterized in that: The side surface of the load installation area corresponding to the sensor cover installation position in the external installation area is the measuring surface, and the sensor measures the measuring surface to obtain the movement of the linear vibration table.

6. The variable stiffness micro-wire vibration table according to claim 3, characterized in that: After the piezoelectric ceramic (6) is energized, it generates displacement according to the voltage variation law, driving the load installation area (12) of the linear vibration table body (1) to move, thereby generating corresponding vibration.

7. The variable stiffness micro-wire vibration table according to claim 3, characterized in that: A first groove is formed on a first side wall of the external installation area (11); A second groove is formed on the second side wall of the external installation area (11); wherein the first side wall and the second side wall are opposite to each other.

8. The variable stiffness micro-wire vibration table according to claim 1, characterized in that: By rotating the stiffness adjustment screw (3), the stiffness preload force can be changed and the fundamental frequency of the linear vibration table can be adjusted.

9. The variable stiffness micro-wire vibration table according to claim 1, characterized in that: The piezoelectric ceramic seat (2) is connected to the linear vibration table body (1) via bolts.

10. The variable stiffness micro-wire vibration table according to claim 1, characterized in that: The preload spring gland (4) is connected to the linear vibration table body (1) via bolts; The sensor pressure cover (5) is connected to the line vibration table body (1) via bolts.

Images