Stiffness-variable micro linear vibration table

Abstract

The application discloses a variable stiffness micro linear vibration table, which comprises a linear vibration table body, a piezoelectric ceramic seat, a stiffness adjusting screw, a pre-tightening spring cover, a sensor cover, a piezoelectric ceramic, a stiffness adjusting buckle, a stiffness adjusting spring, a pre-tightening spring and a sensor. The first side wall of the linear vibration table 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. The second side wall of the linear vibration table body is provided with a second groove, the pre-tightening spring is arranged in the second groove, and the pre-tightening spring cover is connected with the second groove. The linear vibration table body is provided with a third groove, the sensor is arranged in the third groove, and the sensor cover is connected with the third groove. The third side wall of the linear vibration table body is provided with a threaded hole, and the stiffness adjusting buckle and the stiffness adjusting spring are arranged in the threaded hole. The application has the advantages of compact structure, simple use, extremely small displacement or linear vibration and high measurement precision.

Description

Technical Field

[0001] This invention belongs to the field of vibration measurement technology, and in particular relates to a variable stiffness micro linear vibration table. Background Technology

[0002] High-precision inertial devices (such as accelerometers) are primarily used in aerospace and other fields requiring precise attitude control. They acquire accurate motion data through measurement, providing reliable support for the tracking and control of spacecraft. With technological advancements, the requirements for the accuracy and dynamic performance of vibration measurements are becoming increasingly stringent. The continuous improvement in the dynamic performance of measurement devices necessitates high-accuracy dynamic calibration. Accurate evaluation of the dynamic performance of inertial devices is crucial for ensuring and improving the operational stability of spacecraft platforms, including satellites, and for enhancing the quality of aerospace imaging. Therefore, vibration tables capable of generating and measuring high-precision vibrations are of paramount importance.

[0003] Existing vibration tables can be divided into large and micro types. Large vibration tables are generally used to test large structures and typically employ electro-hydraulic or electromagnetic actuation methods. They are complex electromechanical coupling systems, large in size and mass, often fixed in specific locations, making their operation cumbersome. Furthermore, their large size prevents them from providing vibrations at extremely small magnitudes. Micro vibration tables are used to provide minute vibrations for machine tool processing, sensor calibration, etc. They are usually small and easy to use, but current micro vibration tables generally have a very high first-order fundamental frequency to ensure stable dynamic characteristics within the operating frequency range. This results in extremely high stiffness in the vibration direction, requiring a large driving force to drive the table. Therefore, large piezoelectric ceramics or motors are often used for driving, increasing ineffective dimensions. There is also an ultra-miniature satellite vibration table, which is directly fabricated from piezoelectric ceramic sheets. This type of vibration table is typically used for sensor chip calibration, and its size is similar to the chip itself, making it unsuitable for conventional load testing. All of the above vibration tables have a fixed structure and therefore cannot operate near their fundamental frequency. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a variable stiffness micro linear vibration table with a compact structure, simple use, and the ability to generate extremely small displacements or linear vibrations with high measurement accuracy. It can provide the required micro-level, high-precision vibration environment for the load and can adjust the connection stiffness of the moving parts to change the fundamental frequency of the vibration table and avoid resonance to adapt to the needs of different vibration conditions.

[0005] The objective of this invention is achieved through the following technical solution: A variable stiffness micro linear vibration table, comprising: a linear vibration table body, a piezoelectric ceramic seat, a stiffness adjusting screw, a preload spring cover, a sensor cover, a piezoelectric ceramic, a stiffness adjusting buckle, a stiffness adjusting spring, a preload spring, and a sensor; wherein, a first groove is formed on the first side wall of the linear vibration table body, the piezoelectric ceramic is disposed within the groove, the piezoelectric ceramic seat is connected to the first groove, and the piezoelectric ceramic seat presses against the piezoelectric ceramic; a second groove is formed on the second side wall of the linear vibration table body, the preload spring is disposed within the second groove, and the preload spring... The spring cover is connected to the second groove, and the spring cover presses against the spring. The first sidewall and the second sidewall are opposite to each other. The main body of the linear vibration table has a third groove, the sensor is disposed in the third groove, and the sensor cover is connected to the third groove. The third sidewall of the main body of the linear vibration table has a threaded hole, the stiffness adjustment buckle and the stiffness adjustment spring are both disposed in the threaded hole, and the stiffness adjustment screw pushes the stiffness adjustment buckle into the threaded hole and presses the stiffness adjustment spring. The third sidewall is adjacent to the first sidewall and the second sidewall respectively.

[0006] In the aforementioned variable stiffness micro linear vibration table, the preload spring generates a preload force that causes the piezoelectric ceramic to contact the main body of the linear vibration table.

[0007] In the aforementioned variable stiffness micro linear vibration table, the main body of the linear vibration table includes an external mounting area, a load mounting area, and a stiffness adjustment area; wherein, the load mounting area and the stiffness adjustment area are located inside the external mounting area; the load mounting area and the stiffness adjustment area are connected, and both the load mounting area and the stiffness adjustment area are connected to the external mounting area.

[0008] In the aforementioned variable stiffness micro linear vibration table, a third groove is provided in the external mounting area, the sensor is disposed in the third groove, and the sensor cover is connected to the third groove.

[0009] In the aforementioned variable stiffness micro linear vibration table, the side of the load mounting area corresponding to the sensor cover mounting position in the external mounting area is the measurement surface. The sensor measures the measurement surface to obtain the motion of the linear vibration table.

[0010] In the aforementioned variable stiffness micro linear vibration table, when the piezoelectric ceramic is energized, it generates displacement according to the voltage change law, which drives the load mounting area of ​​the main body of the linear vibration table to move, thereby generating corresponding vibration.

[0011] In the aforementioned variable stiffness micro linear vibration table, a first groove is formed on the first sidewall of the external mounting area; a second groove is formed on the second sidewall of the external mounting area; wherein the first sidewall and the second sidewall are opposite to each other.

[0012] In the aforementioned variable stiffness micro linear vibration table, the stiffness preload can be changed by rotating the stiffness adjustment screw, thereby adjusting the fundamental frequency of the linear vibration table.

[0013] In the aforementioned variable stiffness micro linear vibration table, the piezoelectric ceramic base is connected to the main body of the linear vibration table by bolts.

[0014] In the aforementioned variable stiffness micro linear vibration table, the pre-tightening spring cover is connected to the main body of the linear vibration table by bolts; the sensor cover is also connected to the main body of the linear vibration table by bolts.

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

[0016] (1) The present invention can generate extremely small displacements or vibrations and perform high-precision measurements, providing a precise 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 linear vibration table of the present invention has a simple and compact structure, is easy to transport, and can be flexibly installed in any measurement environment by screws. In addition, with different piezoelectric ceramics and sensors, it can achieve a variety of vibration and measurement accuracies. Attached Figure Description

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

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

[0021] Figure 2 This is a schematic diagram of the structure of the variable stiffness micro linear vibration table provided in an embodiment of the present invention;

[0022] Figure 3 This is a cross-sectional view of the variable stiffness micro linear vibration table provided in an embodiment of the present invention. Detailed Implementation

[0023] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This diagram illustrates the installation relationship of a variable stiffness micro linear vibration table during vibration sensor calibration according to the present invention. The load to be measured is represented by a cube, which is installed by connecting screws to the threaded holes in the load mounting area of ​​the linear vibration table. During testing, an external voltage is controlled to cause the linear vibration table to vibrate. The vibration is measured by the sensor on the linear vibration table itself and compared with the measurement of the load to be measured to obtain the calibration result.

[0025] Figure 2 This is a schematic diagram of the structure of the variable stiffness micro linear vibration table provided in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the variable stiffness micro linear vibration table provided in an embodiment of the present invention. Figure 2 and Figure 3 As shown, the variable stiffness micro linear vibration table includes: a linear vibration table body 1, a piezoelectric ceramic seat 2, a stiffness adjusting screw 3, a preload spring cover 4, a sensor cover 5, a piezoelectric ceramic 6, a stiffness adjusting buckle 7, a stiffness adjusting 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 disposed in the 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 together; a second groove is formed on the second side wall of the linear vibration table body 1, the preload spring 9 is disposed in the second groove, and the preload spring 9 is pressed together. The spring pressure cover 4 is connected to the second groove, and the pre-tension spring pressure cover 4 is pressed against the pre-tension spring 9; wherein, the first side wall and the second side wall are opposite to each other; the main body 1 of the linear vibration table has a third groove, the sensor 10 is set in the third groove, and the sensor pressure cover 5 is connected to the third groove; the third side wall of the main body 1 of the linear vibration table has a threaded hole, the stiffness adjustment buckle 7 and the stiffness adjustment spring 8 are both set 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 that causes the piezoelectric ceramic 6 to contact the main body 1 of the linear vibration table.

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

[0028] The external mounting area 11 has a third groove, the sensor 10 is placed in the third groove, and the sensor cover 5 is connected to the third groove.

[0029] In the external installation area, the side of the load installation area corresponding to the sensor cover installation position is the measurement surface. The sensor measures the measurement surface to obtain the motion of the linear vibration table.

[0030] When the piezoelectric ceramic 6 is energized, it generates displacement according to the voltage change law, which drives the load mounting area 12 of the main body 1 of the linear vibration table to move, thereby generating corresponding vibration.

[0031] The first sidewall of the external mounting area 11 has a first groove; the second sidewall of the external mounting area 11 has a second groove; wherein the first sidewall and the second sidewall are opposite to each other.

[0032] The stiffness preload can be changed by rotating the stiffness adjustment screw 3, thereby adjusting the fundamental frequency of the linear vibration table.

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

[0034] The piezoelectric ceramic holder is bolted to the main body of the linear vibration table, allowing the piezoelectric ceramic to be installed inside the main body. The preload spring cover is bolted to the main body of the linear vibration table, pressing the preload spring in to generate a preload force to ensure contact between the piezoelectric ceramic and the main body. The sensor cover is bolted to fix the sensor to the main body of the linear vibration table, allowing for real-time measurement of the vibration of the table. The stiffness adjustment screw pushes the stiffness adjustment clip into the threaded hole and tightens the stiffness adjustment spring. Rotating the stiffness adjustment screw changes the magnitude of the stiffness preload force, thus adjusting the fundamental frequency of the linear vibration table.

[0035] The fundamental frequency of the variable stiffness micro linear vibration table is much lower in the vibration direction than in other directions, making it easy to generate unidirectional deformation while having sufficient support stiffness to mount loads. By controlling the input voltage, it is possible to generate extremely small displacements or linear vibrations in the expansion and contraction directions of the piezoelectric ceramic, and the displacements or vibrations can be accurately measured by sensors, thereby providing precise and minute displacements or vibrations for the load.

[0036] Within the limits of available installation space, different types of piezoelectric ceramics can be selected for variable stiffness micro linear vibration tables, enabling the linear vibration tables to have different stroke and displacement accuracies.

[0037] The main body of the linear vibration table comprises an external mounting area, a load mounting area, and a stiffness adjustment area. The external mounting area is used to fix the load mounting area, the load mounting area is used to install the load required for the vibration environment, and the stiffness adjustment area allows for adjustment of the fundamental frequency of the micro-vibration table. On the top surface of the linear vibration table body, the load mounting area is slightly higher than the other areas; on the bottom surface, the external mounting area is slightly higher than the other areas, ensuring that the load mounting area and the stiffness adjustment area do not come into contact with other areas or the external environment during movement.

[0038] The main body of the vibration table is integrally molded without any other connecting parts, resulting in a compact structure. The three installation areas are connected by a thin sheet structure, ensuring that the linear vibration table can easily generate displacement or vibration, as well as adjust its stiffness, and has sufficient support stiffness to install loads.

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

[0040] The selection of sensors is highly flexible. Various sensors can be matched with tooling at the sensor mounting point to achieve different measurement accuracies. While ensuring accuracy, the sensor does not necessarily have to be connected to the main body of the linear vibration table and can be an external sensor.

[0041] The stiffness adjustment zone consists of inner and outer layers, which not only releases the degree of freedom of the load mounting area and reduces the fundamental frequency of the linear vibration table in the direction of motion, but also avoids shear load on the stiffness adjustment screw. By applying pressure to the stiffness adjustment zone through the stiffness adjustment screw, pressure is applied to the connection with the load mounting area, which can change the fundamental frequency of the load mounting area and prevent resonance when the desired vibration is generated.

[0042] The stiffness adjustment screw presses against the stiffness adjustment clip to tighten the stiffness adjustment spring, thereby applying pressure to the stiffness adjustment area and avoiding direct contact with the area that could cause wear.

[0043] When the piezoelectric ceramic 6 is energized, it generates displacement according to the voltage change law, which drives the load mounting area of ​​the linear vibration table body 1 to move, thereby generating corresponding vibration. The sensor 10 obtains vibration information by measuring the side of the load mounting area, and compares it with the measurement of the load to be measured to obtain the calibration result.

[0044] The variable stiffness micro linear vibration table features a compact structure, convenient transportation, flexible installation, and simple use. The installation position can be adjusted as needed to provide a high-precision micro-vibration environment under different conditions.

[0045] This embodiment can generate extremely small displacements or vibrations and perform high-precision measurements, providing a precise 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 linear vibration table of this embodiment has a simple and compact structure, is easy to transport, and can be flexibly installed in any measurement environment by screws. In addition, with different piezoelectric ceramics and sensors, it can achieve a variety of vibration and measurement accuracies.

[0046] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A variable stiffness micro linear vibration table, characterized in that... include: The linear vibration table consists of a main body (1), a piezoelectric ceramic base (2), a stiffness adjusting screw (3), a preload spring cover (4), a sensor cover (5), a piezoelectric ceramic (6), a stiffness adjusting buckle (7), a stiffness adjusting spring (8), a preload spring (9), and a sensor (10); among which, The first side wall of the main body (1) of the linear vibration table is provided with a first groove, the piezoelectric ceramic (6) is disposed in the first groove, the piezoelectric ceramic seat (2) is connected to the first groove, and the piezoelectric ceramic seat (2) is pressed against the piezoelectric ceramic (6); The second sidewall of the main body (1) of the linear vibration table is provided with a second groove, the preload spring (9) is disposed in the second groove, the preload spring cover (4) is connected to the second groove, and the preload spring cover (4) presses against the preload spring (9); wherein, the first sidewall and the second sidewall are opposite to each other; The main body (1) of the linear vibration table has a third groove, the sensor (10) is disposed in the third groove, and the sensor cover (5) is connected to the third groove; The third sidewall of the main body (1) of the linear vibration table is provided with a threaded hole. The stiffness adjustment buckle (7) and the stiffness adjustment spring (8) are both provided in the threaded hole. The stiffness adjustment screw (3) pushes the stiffness adjustment buckle (7) into the threaded hole and presses the stiffness adjustment spring (8). The third sidewall is adjacent to the first sidewall and the second sidewall respectively. The preload spring (9) generates a preload force that causes the piezoelectric ceramic (6) to contact the main body (1) of the linear vibration table; The main body (1) of the linear vibration table includes an external mounting area (11), a load mounting area (12), and a stiffness adjustment area (13); wherein, The load mounting area (12) and the stiffness adjustment area (13) are located inside the external mounting area (11); The load mounting area (12) and the stiffness adjustment area (13) are connected, and both the load mounting area (12) and the stiffness adjustment area (13) are connected to the external mounting area (11). The external mounting area (11) has a third groove, the sensor (10) is disposed in the third groove, and the sensor cover (5) is connected to the third groove; In the external installation area, the side of the load installation area corresponding to the sensor cover installation position is the measurement surface. The sensor measures the measurement surface to obtain the motion of the linear vibration table. When the piezoelectric ceramic (6) is energized, it generates displacement according to the voltage change law, which drives the load installation area (12) of the main body (1) of the linear vibration table to move, thereby generating corresponding vibration; The first sidewall of the external mounting area (11) is provided with a first groove; The second sidewall of the external mounting area (11) is provided with a second groove; wherein the first sidewall and the second sidewall are opposite to each other; The stiffness preload can be changed by rotating the stiffness adjustment screw (3), thereby adjusting the fundamental frequency of the linear vibration table.

2. The variable stiffness micro linear vibration table according to claim 1, characterized in that: The piezoelectric ceramic base (2) is connected to the main body of the linear vibration table (1) by bolts.

3. The variable stiffness micro linear vibration table according to claim 1, characterized in that: The pre-tightening spring cover (4) is connected to the main body (1) of the linear vibration table by bolts; The sensor cover (5) is connected to the main body (1) of the linear vibration table by bolts.

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