Device with functions of energy collection and variable-load low-frequency vibration isolation

Abstract

The invention provides a device with energy collection and variable-load low-frequency vibration isolation functions. Comprising a vibration isolation platform (1), a vibration isolation base (2), a central force bearing mechanism (3), a negative stiffness mechanism (4) and a piezoelectric plate (5), the vibration isolation platform (1) and the vibration isolation base (2) are arranged in parallel, and the center force bearing mechanism (3) is a telescopic mechanism capable of stretching out and drawing back in the vertical direction of the vibration isolation platform (1), installed between the vibration isolation platform (1) and the vibration isolation base (2) and used for providing vertical positive rigidity and supporting the weight of a vibration isolation object. The negative stiffness mechanism (4) is arranged beside the center force bearing mechanism (3) and used for providing negative stiffness parallel to the direction of the vibration isolation platform (1). The piezoelectric plate (5) is attached to the negative stiffness mechanism (4) and used for generating tension and compression deformation along with bending vibration of the negative stiffness mechanism (4) in the vibration process, and finally mechanical energy is converted into electric energy through the positive piezoelectric effect. The structure has the advantages of being large in bearing capacity, high in load adaptability, compact in structure, easy to manufacture, easy to implement and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of vibration control and vibration energy collection, and in particular relates to a device with both energy collection and variable load low-frequency vibration isolation. Background Art

[0002] A large number of electronic equipment such as sensors and controllers are often installed on the aircraft body structure, and the accuracy and life of these onboard equipment are heavily dependent on the vibration characteristics of the structure; therefore, isolating vibrations from vibration sources such as power machinery has important practical significance for the safety, reliability and durability of infrastructure and equipment.

[0003] As mechanical structures develop towards extreme environments and performance limits, the demand for low-frequency or even ultra-low-frequency vibration isolation is becoming increasingly urgent. In traditional linear vibration isolation theory, only when the excitation frequency is greater than The vibration isolation can only be effective when the natural frequency is more than 10 times. If the low-frequency vibration isolation belt is to be extended, it must be achieved by reducing the stiffness of the system. However, in the case of reducing the stiffness, the spatial layout of the system will be changed and the stability will be sacrificed.

[0004] Quasi-zero stiffness vibration isolation devices solve the contradiction between stiffness and large displacement of linear vibration isolators in low-frequency vibration isolation by introducing negative stiffness. However, most existing quasi-zero stiffness vibration isolation devices are only for rated loads, and undesired load detuning will reduce the low-frequency vibration isolation effect and even affect the stability and reliability of the vibration isolation system.

[0005] On the other hand, the rapid development of microelectronics technology has made low-power independent devices, represented by wireless sensor nodes, widely used in various fields. When the number of devices is large and the deployment is special, the traditional battery-powered method will face difficulties such as high maintenance costs and limited functions. Therefore, the research on the technology of collecting vibration energy from the surrounding environment to power low-power components is important and urgent.

[0006] At present, there is no device that takes into account both low-power independent device power supply and low-frequency vibration isolation. The present invention proposes a device that combines energy collection and variable load low-frequency vibration isolation. Summary of the invention

[0007] The purpose of the present invention is to provide a device that combines energy collection and variable load low-frequency vibration isolation. The present invention can effectively isolate the energy generated by the low-frequency vibration source and is suitable for different load masses. At the same time, it can also collect low-frequency vibration energy to power low-power components. The structure of the present invention has the advantages of large load-bearing capacity, strong load adaptability, compact structure, simple manufacturing, and easy implementation.

[0008] The technical solution of the present invention is: a device with both energy collection and variable load low-frequency vibration isolation, including a vibration isolation platform, a vibration isolation base, a central load-bearing mechanism, a negative stiffness mechanism and a piezoelectric sheet; the vibration isolation platform is arranged in parallel with the vibration isolation base, the central load-bearing mechanism is a telescopic mechanism that can be vertically extended and retracted along the vibration isolation platform, installed between the vibration isolation platform and the vibration isolation base, and is used to provide vertical positive stiffness and support the weight of the vibration isolation object; the negative stiffness mechanism is arranged next to the central load-bearing mechanism, and is used to provide negative stiffness parallel to the direction of the vibration isolation platform; the piezoelectric sheet is attached to the negative stiffness mechanism, and is used to follow the bending vibration of the negative stiffness mechanism during the vibration process to produce tensile and compressive deformation, and finally convert mechanical energy into electrical energy using the positive piezoelectric effect.

[0009] In the aforementioned device that combines energy collection and variable load low-frequency vibration isolation, the negative stiffness mechanism includes a negative stiffness component; the negative stiffness component includes a multi-stage cam structure with the top end fixedly connected to the vibration isolation platform next to the central load-bearing mechanism and a cantilever beam with the bottom end fixedly connected to the vibration isolation base, and a roller is connected to the top of the cantilever beam; the piezoelectric sheet is attached to the cantilever beam; when the vibration isolation platform moves vertically, the roller moves along the contour of the multi-stage cam structure, causing the cantilever beam to bend, vibrate and deform, thereby producing tensile and compressive deformation on the piezoelectric sheet.

[0010] In the aforementioned device for both energy collection and variable load low-frequency vibration isolation, the multi-stage cam structure includes more than one cam arranged linearly in the vertical direction.

[0011] In the aforementioned device combining energy collection and variable load low-frequency vibration isolation, after the vertical positive stiffness is determined, the level of the load mass is determined by the vertical distance d between the centers of each cam.

[0012] In the aforementioned device for both energy collection and variable load low-frequency vibration isolation, the profile curve of the cam is a parabola.

[0013] In the aforementioned device having both energy collection and variable load low-frequency vibration isolation, the highest position of each cam profile corresponds to a static balance position.

[0014] In the aforementioned device having both energy collection and variable load low-frequency vibration isolation, the negative stiffness components include a pair, which are symmetrically distributed on both sides of the central load-bearing mechanism.

[0015] In the aforementioned device that combines energy collection and variable load low-frequency vibration isolation, the central load-bearing mechanism includes a sleeve whose top end is fixedly connected to the vibration isolation platform, and a guide shaft whose bottom end is fixedly connected to the vibration isolation base. The top end of the guide shaft extends into the sleeve and is slidably connected to the sleeve; a spring is sleeved on the guide shaft between the bottom end of the sleeve and the vibration isolation base.

[0016] In the aforementioned device having both energy collection and variable load low-frequency vibration isolation, the spring is an air spring.

[0017] The advantages of the present invention are:

[0018] 1) The present invention realizes effective isolation of low-frequency or even ultra-low-frequency vibration energy by introducing a negative stiffness mechanism in parallel with a positive stiffness mechanism;

[0019] 2) Compared with the traditional low-frequency vibration isolator which only targets the rated load, the device of the present invention realizes multiple low dynamic stiffness areas by introducing multiple cams arranged in a vertical array, thereby achieving effective vibration isolation for various load-bearing masses;

[0020] 3) The present invention integrates low-frequency vibration isolation and energy harvesting technologies, which can not only isolate the low-frequency vibration source but also collect low-frequency vibration energy to power low-power components;

[0021] 4) The device of the present invention is suitable for low-frequency and small-amplitude vibration isolation occasions, and has the advantages of large bearing capacity, strong load adaptability, compact structure, simple manufacturing, and energy collection;

[0022] 5) The present invention can adapt to changes in load mass, that is, no additional manual adjustment is required when the load mass changes, which broadens the applicable scenarios of the vibration isolation device;

[0023] 6) The present invention introduces a parabolic cam profile, simplifies the solution process of the theoretical analysis, and avoids the introduction of truncation errors during theoretical analysis; at the same time, the present invention can also improve the matching degree of the vibration isolation scene by designing the cam profile parameters.

[0024] In summary, the present invention can effectively isolate the energy generated by the low-frequency vibration source, and is applicable to different load masses, while also being able to collect low-frequency vibration energy to power low-power components. The structure of the present invention has the advantages of large bearing capacity, strong load adaptability, compact structure, simple manufacturing, and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the overall structure of the energy collection and variable load low-frequency vibration isolation device described in the present invention.

[0026] Figure 2 It is a schematic diagram of the device of the present invention working in a static equilibrium state.

[0027] Figure 3 It is a schematic diagram of the outline of the multi-stage cam structure of the device described in the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0030] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] Example 1: Figure 1 As shown, in this embodiment, a device with both energy collection and variable load low-frequency vibration isolation is composed of a vibration isolation platform 1, a vibration isolation base 2, a central force-bearing mechanism 3, a negative stiffness mechanism 4 and a piezoelectric sheet 5. The central force-bearing mechanism 3 is composed of a sleeve 31 and a spring 32 installed on a guide shaft 33 from top to bottom. The sleeve 31 and the guide shaft 33 can ensure that the vibration isolation device vibrates in the vertical direction; the spring 32 is fixed on the sleeve and the vibration isolation base, and can slide freely on the guide shaft 33 to cope with different load masses. The negative stiffness mechanism 4 is symmetrically distributed on both sides of the central load-bearing mechanism 3, and is specifically composed of a multi-stage cam structure 41, a roller 42 and a cantilever beam 43; the upper part of the multi-stage cam structure 41 is fixedly connected to the vibration isolation platform, and the lower part of the cantilever beam 43 is a fixed end to the vibration isolation base; the multi-stage cam structure 41 is composed of three cams arranged vertically and linearly, and the cam profile curve is in the form of a parabola. The function of the cam is to convert the vertical vibration displacement into the horizontal flexural deformation of the cantilever beam 43 through the interaction with the roller. The piezoelectric sheet 5 is pasted on the outside of two symmetrically distributed cantilever beams 43, and produces tensile and compressive deformations following the bending vibration of the cantilever beam 43 during the vibration process, and finally uses the positive piezoelectric effect to convert mechanical energy into electrical energy for energy collection.

[0032] like Figure 2 As shown, a schematic diagram of the device of this embodiment in a static balance position is shown. In the static balance state, the roller is at the highest position of the cam profile, and the resultant forces generated by the negative stiffness mechanism offset each other in the horizontal direction. The three cams are arranged vertically linearly, and the highest position of each cam profile corresponds to a static balance position, so as to achieve effective vibration isolation of the three load-bearing masses. When the cam is above or below the static balance position, the resultant forces of the negative stiffness mechanism in the horizontal direction offset each other, and the resultant forces in the vertical direction are used to generate negative stiffness to resist the positive stiffness of the spring 32 and then form low dynamic stiffness, so as to achieve the purpose of low-frequency vibration isolation.

[0033] like Figure 3 As shown, in this embodiment, the contour line of the cam is set to a parabola (i.e., a quadratic function), and the multi-stage cam structure is composed of a single cam arranged vertically linearly. When the spring 32 is selected, the level of the load mass is determined by the vertical distance d between the centers of each cam.

[0034] Example 2. A device that combines energy collection and variable load low-frequency vibration isolation, see Figure 1-Figure 3 , including a vibration isolation platform 1, a vibration isolation base 2, a central load-bearing mechanism 3, a negative stiffness mechanism 4 and a piezoelectric sheet 5; the vibration isolation platform 1 is arranged in parallel with the vibration isolation base 2, the central load-bearing mechanism 3 is a telescopic mechanism that can be vertically extended and retracted along the vibration isolation platform 1, installed between the vibration isolation platform 1 and the vibration isolation base 2, and is used to provide vertical positive stiffness and support the weight of the vibration isolation object; the negative stiffness mechanism 4 is arranged next to the central load-bearing mechanism 3, and is used to provide negative stiffness parallel to the direction of the vibration isolation platform 1; the piezoelectric sheet 5 is attached to the negative stiffness mechanism 4, and is used to follow the bending vibration of the negative stiffness mechanism 4 during the vibration process to produce tensile and compressive deformation, and finally use the positive piezoelectric effect to convert mechanical energy into electrical energy for energy collection.

[0035] The aforementioned negative stiffness mechanism 4 includes a negative stiffness component; the negative stiffness component includes a multi-stage cam structure 41 fixedly connected to the vibration isolation platform 1 next to the central load-bearing mechanism 3 at the top and a cantilever beam 43 fixedly connected to the vibration isolation base 2 at the bottom, and a roller 42 is connected to the top of the cantilever beam 43; the piezoelectric sheet 5 is attached to the cantilever beam 43; when the vibration isolation platform 1 moves vertically, the roller 42 moves along the contour of the multi-stage cam structure 41, causing the cantilever beam 43 to bend and vibrate and deform, thereby generating tensile and compressive deformation on the piezoelectric sheet 5. When the vibration environment provides vibration excitation to the vibration isolation platform 1 or the vibration isolation base 2 of the device, the cantilever beam 43 simultaneously undergoes bending vibration, causing the piezoelectric sheet 5 to vibrate at the same frequency as the cantilever beam 43, and finally the positive piezoelectric effect of the piezoelectric material is used to convert mechanical energy into electrical energy for energy collection.

[0036] The aforementioned multi-stage cam structure 41 includes more than one cam arranged vertically and linearly. The cam profile curve is in the form of a parabola, and the function of the cam is to convert the vertical vibration displacement into the horizontal deflection deformation of the long plate cantilever beam through the interaction with the roller.

[0037] After the vertical positive stiffness is determined, the level of the load mass is determined by the vertical distance d between the centers of each cam.

[0038] The profile curve of the aforementioned cam is a parabola.

[0039] The highest position of each cam profile corresponds to a static balance position, so as to achieve effective vibration isolation for various load-bearing masses.

[0040] The aforementioned negative stiffness components include a pair, which are symmetrically distributed on both sides of the central load-bearing mechanism 3 .

[0041] The aforementioned central load-bearing mechanism 3 includes a sleeve 1 whose top end is fixedly connected to the vibration isolation platform 1, and a guide shaft 33 whose bottom end is fixedly connected to the vibration isolation base 2. The top end of the guide shaft 33 extends into the sleeve 1 and is slidably connected to the sleeve 1; a spring 32 is sleeved on the guide shaft 33 between the bottom end of the sleeve 1 and the vibration isolation base 2. The sleeve 31 and the vertical guide shaft 33 ensure that the device maintains vertical movement; the vertical spring 32 is used to provide vertical positive stiffness and support the weight of the vibration isolation object.

[0042] The aforementioned spring 32 is an air spring, and the spring 32 may also be equivalent to an air spring or the like.

[0043] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A device for energy collection and variable load low frequency vibration isolation, characterized in that: The invention comprises a vibration isolation platform (1), a vibration isolation base (2), a central load-bearing mechanism (3), a negative stiffness mechanism (4) and a piezoelectric sheet (5); the vibration isolation platform (1) and the vibration isolation base (2) are arranged in parallel; the central load-bearing mechanism (3) is a telescopic mechanism that can be vertically telescopic along the vibration isolation platform (1), is installed between the vibration isolation platform (1) and the vibration isolation base (2), and is used to provide vertical positive stiffness and support the weight of the vibration isolation object; the negative stiffness mechanism (4) is arranged beside the central load-bearing mechanism (3), and is used to provide negative stiffness in a direction parallel to the vibration isolation platform (1); the piezoelectric sheet (5) is attached to the negative stiffness mechanism (4), and is used to generate tensile and compressive deformation in accordance with the bending vibration of the negative stiffness mechanism (4) during vibration, and finally converts mechanical energy into electrical energy by using the positive piezoelectric effect.

2. The device for energy collection and variable load low-frequency vibration isolation according to claim 1 is characterized in that: The negative stiffness mechanism (4) comprises a negative stiffness component; the negative stiffness component comprises a multi-stage cam structure (41) whose top end is fixedly connected to a vibration isolation platform (1) next to a central load-bearing mechanism (3) and a cantilever beam (43) whose bottom end is fixedly connected to a vibration isolation base (2), and a roller (42) is connected to the top end of the cantilever beam (43); the piezoelectric sheet (5) is attached to the cantilever beam (43); when the vibration isolation platform (1) moves vertically, the roller (42) moves along the contour of the multi-stage cam structure (41), causing the cantilever beam (43) to bend, vibrate and deform, thereby generating tensile and compressive deformation on the piezoelectric sheet (5).

3. The device for energy collection and variable load low frequency vibration isolation according to claim 2 is characterized in that: The multi-stage cam structure (41) comprises more than one cam arranged linearly in the vertical direction.

4. The device for energy collection and variable load low-frequency vibration isolation according to claim 3 is characterized in that: After the vertical positive stiffness is determined, the level of the load mass is determined by the vertical distance d between the centers of each cam.

5. The device for energy collection and variable load low frequency vibration isolation according to claim 3, characterized in that: The profile curve of the cam is a parabola.

6. The device for energy collection and variable load low frequency vibration isolation according to claim 3, characterized in that: The highest position of each cam profile corresponds to a static equilibrium position.

7. The device for energy collection and variable load low frequency vibration isolation according to claim 2, characterized in that: The negative stiffness components include a pair, which are symmetrically distributed on both sides of the central load-bearing mechanism (3).

8. The device for energy collection and variable load low frequency vibration isolation according to claim 1, characterized in that: The central load-bearing mechanism (3) comprises a sleeve (1) whose top end is fixedly connected to the vibration isolation platform (1), and a guide shaft (33) whose bottom end is fixedly connected to the vibration isolation base (2); the top end of the guide shaft (33) extends into the sleeve (1) and is slidably connected to the sleeve (1); a spring (32) is sleeved on the guide shaft (33) between the bottom end of the sleeve (1) and the vibration isolation base (2).

9. The device for energy collection and variable load low frequency vibration isolation according to claim 8, characterized in that: The spring (32) is an air spring.

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