Quasi-zero stiffness vibration isolator simulating insect jumping foot structure

Abstract

The invention relates to the technical field of vibration control, and discloses a quasi-zero stiffness vibration isolator imitating an insect jumping foot structure, which comprises a base and a bearing table between which a vertical spring is arranged, the two sets of connecting rod mechanisms are arranged between the base and the bearing table, each set of connecting rod mechanism comprises two lower connecting rods, two upper connecting rods and two middle connecting rods, the two lower connecting rods are hinged to the top face of the base, the two upper connecting rods are hinged to the bottom face of the bearing table, and the two middle connecting rods are distributed in an X shape; two ends of the two middle connecting rods are respectively hinged with the lower connecting rod and the upper connecting rod; the transverse springs are arranged at the hinged positions of the two lower connecting rods and the two middle connecting rods and the hinged positions of the two upper connecting rods and the two middle connecting rods correspondingly. The vibration isolator is simple in structure, small in transverse size, convenient to assemble and disassemble and easy to adjust, quasi-zero-stiffness vibration isolation is achieved through the special mechanical property of the overall structure, vibration energy can be efficiently absorbed, and the vibration isolator has wide application prospects in the field of low-frequency vibration control.

Description

Technical Field

[0001] The invention relates to the technical field of vibration control, in particular to a quasi-zero stiffness vibration isolator with an insect jumping foot imitation structure. Background Art

[0002] With the rapid development of modern engineering technology and the continuous improvement of people's living standards, equipment vibration issues have received increasing attention and become a research hotspot. Based on the analysis of vibration theory, it is shown that the traditional linear vibration isolation method has obvious limitations: it can only be used when the excitation frequency exceeds the natural frequency of the vibration isolation system. Effective vibration isolation can only be achieved when the vibration coefficient is increased by several times. To achieve low-frequency vibration isolation, the system stiffness must be significantly reduced, but this inevitably weakens the load-bearing capacity of the mechanical system. Therefore, achieving effective low-frequency vibration isolation while maintaining load-bearing capacity remains a technical challenge that needs to be overcome in the field of vibration engineering.

[0003] To address this technical difficulty, the prior art has developed a quasi-zero stiffness vibration isolator. This device is constructed by arranging a plurality of mutually hinged and parallel X-shaped links with a transverse spring negative stiffness mechanism on both sides of the stage and the base plate. Although this quasi-zero stiffness vibration isolator can adapt to low-frequency and even ultra-low-frequency vibration isolation, during the vibration isolation process of the above-mentioned vibration isolator, the negative stiffness mechanism first causes the plurality of mutually hinged X-shaped links to extend laterally under the force, and then indirectly transmits the vibration force to the transverse spring, so that the entire negative stiffness mechanism is difficult to efficiently absorb vibration energy. At the same time, the negative stiffness mechanism arranged on both sides of the stage and the base plate causes the lateral size of the entire vibration isolator to be large, which restricts its diversified application in actual engineering. Summary of the Invention

[0004] The present invention proposes a quasi-zero stiffness vibration isolator with an insect jumping foot-like structure to address the deficiencies in the above-mentioned prior art. The quasi-zero stiffness vibration isolator with an insect jumping foot-like structure can efficiently absorb vibration energy on the basis of having low-frequency and even ultra-low-frequency vibration isolation effects, and has a small lateral size, adapting to diverse working environments in engineering.

[0005] The technical solution of the present invention is: a quasi-zero stiffness vibration isolator with an insect jumping foot structure, comprising a base and a bearing platform, a vertical spring is provided between the base and the bearing platform, and further comprising:

[0006] Two groups of connecting rod mechanisms are arranged between the base and the bearing platform, and the vertical spring is located between the two groups of connecting mechanisms. Each group of the connecting rod mechanisms includes two lower connecting rods, two upper connecting rods and two middle connecting rods. The two lower connecting rods are hinged to the top surface of the base, and the two upper connecting rods are hinged to the bottom surface of the bearing platform. The two middle connecting rods are distributed in an X shape, and the two ends of the two middle connecting rods are respectively hinged to the lower connecting rods and the upper connecting rods;

[0007] A plurality of transverse springs are respectively and horizontally arranged at the hinges of the two lower connecting rods and the two middle connecting rods and at the hinges of the two upper connecting rods and the two middle connecting rods on each group of connecting rod mechanisms.

[0008] In at least one embodiment of the present invention, the length of the middle connecting rod is greater than the lengths of the lower connecting rod and the upper connecting rod.

[0009] In at least one embodiment of the present invention, two mounting plates are provided on both sides of the length direction of the transverse spring, the two upper connecting rods and the two middle connecting rods on each group of the connecting rod mechanism are hinged on the two mounting plates, and the two ends of the plurality of transverse springs are respectively provided on the two mounting plates.

[0010] In at least one embodiment of the present invention, two mounting blocks are provided on both sides of the length direction of the transverse spring, the two lower connecting rods and the two middle connecting rods on each group of the connecting rod mechanism are hinged on the two mounting blocks, and the two ends of the transverse spring are respectively connected to the two mounting blocks.

[0011] In at least one embodiment of the present invention, the hinge points between the four lower connecting rods and the base are arranged in a rectangular pattern, and the hinge points between the four upper connecting rods and the support platform are arranged in a rectangular pattern. In each group of the linkage mechanisms, the distance between the hinge points between the two lower connecting rods and the base is smaller than the distance between the hinge points between the two upper connecting rods and the support platform.

[0012] In at least one embodiment of the present invention, mounting tubes are provided opposite to each other at the center of the top surface of the base and the center of the bottom surface of the supporting platform, and both ends of the vertical spring are respectively embedded in the two mounting tubes.

[0013] In at least one embodiment of the present invention, the base, the supporting platform, the lower connecting rod, the upper connecting rod and the middle connecting rod are made of foamed aluminum, magnesium-based bionic material or EPP, and the vertical spring and the transverse spring are made of the same material.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The application sets two groups of link mechanisms composed of lower links, two upper links and two middle links between the base and the bearing table, when the bearing table is displaced under force, the movement mode of the lower links, upper links and middle links is similar to the skeletal movement of insect jumping legs in the jumping process, and the lateral springs simulate the elastic effect of the muscles in the insect jumping legs; the effective absorption of vibration energy is realized, according to the positive and negative stiffness cancellation principle, the vibration isolator reaches quasi-zero stiffness, that is, when the object to be isolated vibrates up and down in the balance position, the dynamic stiffness is very low, so that the whole system has a very low natural frequency, thereby achieving low-frequency and ultra-low-frequency vibration isolation; and since the two middle links in each group of link mechanisms are distributed in X shape and the two middle links are not hinged, the link mechanism of the application is two degrees of freedom, and under the cooperation of multiple lateral springs, the bearing table can bear axial vibration and directly convert part of the axial vibration into swinging motion inside the link mechanism, so that the vibration energy can be efficiently absorbed, the overall size of the vibration isolator is reduced, the space utilization is improved, and the diversified working environment in engineering is adapted.

[0016] 2. The quasi-zero stiffness vibration isolator provided by the application has the advantages of simple and reliable structure design, low manufacturing cost and strong universality. The vibration isolator can flexibly design the connecting piece according to the actual working condition, and adapt to different bearing conditions by actively adjusting the spring pre-tensioning state, thereby effectively avoiding the risk of failure of the vibration isolation system.

[0017] 3. The application solves the problems of limited applicability of the current quasi-zero stiffness vibration isolator and insufficient application of the tensegrity structure in engineering practice, and provides an innovative solution for controlling and eliminating various low-frequency harmful vibrations (such as vehicle driving bumping, aircraft flight vibration and mechanical equipment operation vibration, etc.). At the same time, the research also opens up a new way for the practical application of tensegrity structure in engineering field, and has important theoretical value and practical significance. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the application;

[0019] Figure 2 It is a stiffness and bearing table-base relative height relationship trend graph of the link mechanism of the application;

[0020] Figure 3 It is an equivalent force and bearing table-base relative height relationship trend graph generated by the application.

[0021] Explanation of reference signs:

[0022] 1. base; 2. bearing table; 3. vertical spring; 4. link mechanism; 41. lower link; 42. upper link; 43. middle link; 5. lateral spring; 6. mounting plate; 7. mounting block; 8. mounting pipe. DETAILED DESCRIPTION

[0023] The drawings in the present invention are not drawn strictly to scale, and the specific size and quantity of each structure can be determined according to actual needs. The drawings described in the present invention are only schematic structural diagrams.

[0024] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Inside", "outside", "up", "down", "far", "near", "front", "back" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0026] The jumping leg of an insect is a highly specialized leg designed primarily for rapid leaping. Its structural features are primarily reflected in the femur and tibia. The femur is typically highly developed and thicker than other leg types, housing extensive muscles that store a large amount of elastic potential energy. The tibia is slender and, in conjunction with the femur, achieves rapid extension through muscle contraction and relaxation, generating jumping force. The jumping leg provides insects with powerful jumping capabilities, enabling them to move quickly and efficiently, effectively avoiding predators or finding food. For example, locusts can leap several or even dozens of times their body length. A 3-gram locust can leap 30 centimeters high and 70 centimeters long. The jumping leg converts stored elastic potential energy into kinetic energy through rapid muscle contraction and extension, enabling efficient leaps. Crickets also have specialized jumping legs, possessing powerful jumping abilities, enabling them to quickly evade predators. Despite their tiny size, fleas possess remarkable jumping abilities, reaching heights exceeding 100 times their body length. The jumping legs of these insects are adaptive structures formed during their long evolution process, helping them survive in complex ecological environments.

[0027] The engineering community generally uses a method of connecting positive and negative springs in parallel to design quasi-zero-stiffness isolators. These isolators possess the unique mechanical properties of high static stiffness and low dynamic stiffness, effectively isolating low- and even ultra-low-frequency vibrations. However, existing quasi-zero-stiffness isolators often only achieve this characteristic under specific load conditions, severely limiting their diverse applications in practical engineering.

[0028] Based on this, drawing on the unique skeletal-muscle coordination mechanism of natural insect jumping legs (such as locusts), a generalized tensegrity structure with adjustable negative stiffness range characteristics was designed. Leveraging this structure's excellent adjustable mechanical properties, the present invention proposes a novel quasi-zero stiffness vibration isolator that mimics the structure of an insect jumping leg.

[0029] like Figure 1 As shown, a quasi-zero stiffness vibration isolator with an insect jumping foot structure includes a base 1 and a bearing platform 2, a vertical spring 3 is provided between the base 1 and the bearing platform 2, and further includes:

[0030] Two groups of connecting rod mechanisms 4 are arranged between the base 1 and the supporting platform 2, and the vertical spring 3 is located between the two groups of connecting mechanisms 4. Each group of connecting rod mechanisms 4 includes two lower connecting rods 41, two upper connecting rods 42 and two middle connecting rods 43. The two lower connecting rods 41 are hinged to the top surface of the base 1, and the two upper connecting rods 42 are hinged to the bottom surface of the supporting platform 2. The two middle connecting rods 43 are distributed in an X shape, and the two ends of the two middle connecting rods 43 are hinged to the lower connecting rods 41 and the upper connecting rods 42 respectively; the connecting rod mechanism 4 can withstand axial vibration of the supporting platform 2 while converting part of it into swinging motion inside the connecting rod mechanism 4, so that it can not only efficiently absorb vibration energy, but also reduce the overall size of the vibration isolator, improve space utilization, and at the same time.

[0031] Multiple transverse springs 5 ​​are horizontally positioned at the hinges of the two lower links 41 and the two middle links 43, as well as at the hinges of the two upper links 42 and the two middle links 43, on each linkage 4. The elastic parameters and pre-tension state of the transverse springs 5 ​​can be adjusted according to the actual load, ensuring that the tensegrity structure achieves adjustable negative stiffness under axial load. The restoring force provided by the vertical springs 3 ensures that the tensegrity structure operates within the negative stiffness range. When connected in parallel, the two achieve a quasi-zero stiffness state, significantly reducing the system's dynamic stiffness and widening the low-frequency vibration isolation range. The pre-strained transverse springs 5 ​​of the linkage 4 facilitate adjustment of the structure's mechanical properties.

[0032] Specifically, the material selection and sizing of the lower connecting rod 41, upper connecting rod 42, middle connecting rod 43, and transverse spring 5 are optimized based on the biomechanical properties of an insect's jumping foot. By simulating the multi-rod coordinated motion and elastic energy storage mechanism of an insect's foot, the articulated motion of the connecting rod mechanism 4 and the elastic deformation of the transverse spring 5 work together to efficiently absorb vibration energy. Depending on the load conditions, the isolator's spring can be replaced or its pre-tensioned state can be changed to ensure the ideal dynamic stiffness of the isolator is near zero under static load, thus preventing failure of the isolation system.

[0033] As an alternative embodiment, the length of the middle connecting rod 43 is greater than the length of the lower connecting rod 41 and the upper connecting rod 42, thereby making the connecting rod mechanism 4 of the quasi-zero stiffness vibration isolator closer to the shape of an insect jumping foot, providing a larger swing space for the connecting rod mechanism 4, so that the quasi-zero stiffness vibration isolator can not only efficiently absorb vibration energy, but also reduce the overall size of the vibration isolator.

[0034] As an alternative embodiment, two mounting plates 6 are provided on both sides of the transverse spring 5 in the length direction, and the two upper connecting rods 42 and the two middle connecting rods 43 on each group of connecting rod mechanisms 4 are hinged on the two mounting plates 6. The two ends of multiple transverse springs 5 ​​are respectively arranged on the two mounting plates 6. The arrangement of the mounting plates 6 can be adjusted to allow multiple transverse springs 5 ​​to be arranged between the two mounting plates 6 according to actual needs. Specifically, the transverse spring 5 is detachably connected to the two mounting plates 6.

[0035] As an alternative embodiment, two mounting blocks 7 are provided on both sides of the transverse spring 5 in the length direction, and the two lower connecting rods 41 and the two middle connecting rods 43 on each group of connecting rod mechanisms 4 are hinged on the two mounting blocks 7. The two ends of the transverse spring 5 are respectively connected to the two mounting blocks 7. Specifically, the two ends of the transverse spring 5 are detachably connected to the two mounting blocks 7.

[0036] As an alternative embodiment, the hinge points between the four lower connecting rods 41 and the base 41 are distributed in a rectangular shape, and the hinge points between the four upper connecting rods 42 and the supporting platform 2 are distributed in a rectangular shape; so that when the supporting platform 2 is subjected to vibration force, the force applied to each connecting rod mechanism 4 is more uniform, and the distance between the two lower connecting rods 41 on each group of connecting rod mechanisms 4 and the hinge point of the base 1 is smaller than the distance between the two upper connecting rods 42 and the hinge point of the supporting platform 2.

[0037] As an alternative embodiment, mounting tubes 8 are provided relative to each other at the center of the top surface of the base 1 and the center of the bottom surface of the supporting platform 2, and the two ends of the vertical spring 3 are respectively embedded in the two mounting tubes 8; the positioning of the vertical spring 3 by the mounting tubes 8 can facilitate the adjustment and replacement of the vertical spring 3 according to needs.

[0038] As an alternative embodiment, the base 1, the supporting platform 2, the lower connecting rod 41, the upper connecting rod 42 and the middle connecting rod 43 are made of foam aluminum, magnesium-based bionic material or EPP, which is required to be a lightweight and high-strength buffering and energy-absorbing material. The vertical spring 3 and the transverse spring 5 are made of the same material.

[0039] The working principle and usage of this embodiment:

[0040] The present invention provides a quasi-zero stiffness vibration isolator that simulates the structure of an insect jumping leg. When the quasi-zero stiffness vibration isolator is in use, after the object to be isolated is placed on the support platform 2 and reaches the equilibrium position, the vertical spring 3 generates positive stiffness in the vertical direction, providing a high static bearing capacity; the connecting rod mechanism 4 generates negative stiffness in the vertical direction in cooperation with the transverse spring 5: when the support platform 2 is displaced by force, the movement pattern of the lower connecting rod 41, the upper connecting rod 42 and the middle connecting rod 43 in the connecting rod mechanism 4 is similar to the skeletal movement of the insect jumping leg during the jumping process, and the transverse spring 5 simulates the elastic effect of the muscles in the insect jumping leg. Through the mutual cooperation between the lower connecting rod 41, the upper connecting rod 42 and the middle connecting rod 43 of each component, effective absorption of vibration energy is achieved. According to the principle of positive and negative stiffness cancellation, the vibration isolator achieves quasi-zero stiffness, that is, when the object to be isolated vibrates up and down at the equilibrium position, the dynamic stiffness is extremely low and can be considered to be equal to zero, so that the entire system has a very low natural frequency, thereby achieving the purpose of low-frequency and ultra-low-frequency vibration isolation.

[0041] The tensegrity structure of the insect-like jumping foot has adjustable positive / negative stiffness. Under vertical load, its configuration changes, achieving adjustment from positive stiffness to negative stiffness. The vertical stiffness curve of the structure with the relative height y of the support platform 2 and the base 1 is shown in the figure below. Figure 2 As shown. For the tensegrity structure simulating the jumping feet of insects, the initial equilibrium configuration of the structure is obtained when the relative height y=1.5, at which time the structural stiffness is the minimum. In the deformation range 1.0<y<3.0, the lower connecting rod 41, the upper connecting rod 42, the middle connecting rod 43 and the transverse spring 5 will not interfere with each other. When the structure is subjected to axial tensile load, the relative height of the structure gradually increases, and the axial stiffness of the structure changes nonlinearly. Specifically: when 1≤y<y1, the stiffness of the structure first decreases from a positive value to 0; when y1≤y<y2, the stiffness of the structure first decreases and then increases, and is always a negative value; when y2≤y<3, the stiffness of the structure starts from 0 and continues to increase, and is always a positive value. Among them, the values ​​of the positive and negative stiffness interval conversion points y1 and y2 are related to the material and pre-tension state of the transverse spring 5.

[0042] In actual use, components of appropriate materials and sizes can be selected according to actual working conditions to assemble the above-mentioned tensegrity structure of the simulated insect jumping foot; and according to the required bearing capacity and the magnitude of the negative stiffness of the above-mentioned tensegrity structure of the simulated insect jumping foot, a vertical spring 2 of appropriate stiffness can be selected and fitted into the mounting tube 8 between the base 1 and the support platform 2. The combination of the two ensures that the vibration isolator is in an ideal state with a dynamic stiffness close to zero under static load, such as Figure 3 As shown in the figure, within the quasi-zero stiffness range, the force generated by the isolator hardly changes with the relative height of the platform. This prevents failure of the vertical spring and improves the load-bearing capacity of the isolator by adjusting its pre-compression.

[0043] The above embodiments are only specific implementation methods of the patent of the present invention, which are used to illustrate the technical solutions of the patent of the present invention rather than to limit it. The protection scope of the patent of the present invention is not limited thereto. Although the patent of the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that any technician familiar with this technical field can still modify the technical solutions recorded in the above embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions implemented by the patent of the present invention, and should all be covered by the protection scope of the present invention.

Claims

1. A quasi-zero stiffness vibration isolator with an insect jumping foot structure, comprising a base (1) and a bearing platform (2), wherein a vertical spring (3) is provided between the base (1) and the bearing platform (2), and characterized in that: Also includes: Two groups of connecting rod mechanisms (4) are both arranged between the base (1) and the bearing platform (2); the vertical spring (3) is located between the two groups of connecting rod mechanisms (4); each group of the connecting rod mechanisms (4) includes two lower connecting rods (41), two upper connecting rods (42) and two middle connecting rods (43); the two lower connecting rods (41) are hinged to the top surface of the base (1); the two upper connecting rods (42) are hinged to the bottom surface of the bearing platform (2); the two middle connecting rods (43) are distributed in an X shape; the two ends of the two middle connecting rods (43) are hinged to the lower connecting rods (41) and the upper connecting rods (42) respectively; A plurality of transverse springs (5) have their ends respectively connected to the hinges of the two lower connecting rods (41) and the two middle connecting rods (43) on each group of connecting rod mechanisms (4), and the hinges of the two upper connecting rods (42) and the two middle connecting rods (43).

2. The quasi-zero stiffness vibration isolator with an insect jumping foot structure as claimed in claim 1, characterized in that: The length of the middle connecting rod (43) is greater than the lengths of the lower connecting rod (41) and the upper connecting rod (42).

3. The quasi-zero stiffness vibration isolator with an insect jumping foot structure as claimed in claim 1, characterized in that: Two mounting plates (6) are provided on both sides of the transverse spring (5) in the length direction. The two upper connecting rods (42) and the two middle connecting rods (43) on each group of the connecting rod mechanism (4) are hinged on the two mounting plates (6). The two ends of the plurality of transverse springs (5) are respectively provided on the two mounting plates (6).

4. The quasi-zero stiffness vibration isolator with an insect jumping foot structure as claimed in claim 1, characterized in that: Two mounting blocks (7) are provided on both sides of the transverse spring (5) in the length direction. The two lower connecting rods (41) and the two middle connecting rods (43) on each group of the connecting rod mechanism (4) are hinged on the two mounting blocks (7). The two ends of the transverse spring (5) are respectively connected to the two mounting blocks (7).

5. The quasi-zero stiffness vibration isolator with an insect jumping foot structure as claimed in claim 1, characterized in that: Mounting tubes (8) are provided at the center of the top surface of the base (1) and the center of the bottom surface of the supporting platform (2) relative to each other, and the two ends of the vertical spring (3) are respectively embedded in the two mounting tubes (8).

6. The quasi-zero stiffness vibration isolator with an insect jumping foot structure as claimed in claim 1, characterized in that: The hinge points between the four lower connecting rods (41) and the base (41) are distributed in a rectangular shape, and the hinge points between the four upper connecting rods (42) and the bearing platform (2) are distributed in a rectangular shape.

7. The quasi-zero stiffness vibration isolator with an insect jumping foot structure as claimed in claim 1, characterized in that: The base (1), the supporting platform (2), the lower connecting rod (41), the upper connecting rod (42) and the middle connecting rod (43) are made of foamed aluminum, magnesium-based bionic material or EPP, and the vertical spring (3) and the transverse spring (5) are made of the same material.

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