Magnetic-embedded paper-cut type quasi-zero stiffness vibration isolator

Abstract

A magnetic-embedded paper-cut type quasi-zero stiffness vibration isolator comprises a base, a movable frame and four bearing blocks which are rotatably arranged in the movable frame and are of the same structure, one side of each bearing block is rotatably connected with the movable frame or the base, the other side of each bearing block is connected with the adjacent bearing block, and the third side of each bearing block and the adjacent bearing block mutually repel through magnetic force. Therefore, the movable frame is in a single-degree-of-freedom motion mode, vertical compression and stretching are allowed, and the whole device realizes nonlinear displacement coupling of positive and negative rigidity magnetic groups. Through the modular magnetic group design, the embedded layout of the standardized bearing blocks and the magnet grooves is adopted, the negative stiffness mechanism and the positive stiffness mechanism jointly contribute nonlinear stiffness, and quasi-zero stiffness is achieved through modulation. The rigidity of the positive part and the rigidity of the negative part are both generated by the magnets, so that the rigidity of the vibration isolation device can be flexibly adjusted and controlled only by adjusting the specifications of the magnets, rapid modular splicing and reconstruction of the vibration isolation units can be achieved, and different load requirements are met. And meanwhile, through the self-stability of the magnetic repulsive force, the performance consistency of the vibration isolator under long-term high load is remarkably improved.

Description

Technical Field

[0001] The present invention relates to a technology in the field of mechanical vibration isolation, in particular to a magnetic embedded paper-kirigami type quasi-zero stiffness vibration isolator. Background Art

[0002] Traditional elastic vibration isolation structures utilize material elasticity to generate restoring force, but due to their low stiffness, they are unable to effectively isolate high-load vibrations. They are also prone to fatigue softening after long-term loads, resulting in uncontrollable overall stiffness. Furthermore, the material's elastic modulus is highly sensitive to environmental changes, impacting system stability. Summary of the Invention

[0003] To address the problems of low stiffness, insufficient fatigue resistance, and limited application scenarios in existing elastic vibration isolation structures, this paper-cut magnetic quasi-zero stiffness isolator is proposed. This design utilizes a modular magnetic assembly and an embedded layout of standardized bearing blocks and magnet grooves. Both negative and positive stiffness mechanisms contribute to the nonlinear stiffness, and both components are generated by magnets. Therefore, the stiffness of the isolation device can be flexibly adjusted by simply adjusting the magnet specifications. This allows for rapid modular assembly and reconstruction of the isolation unit to accommodate varying load requirements. Furthermore, the self-stability of the magnetic repulsion significantly improves the performance consistency of the isolator under long-term high loads.

[0004] The present invention is achieved through the following technical solutions:

[0005] The present invention relates to a magnetically embedded paper-kirigami-type quasi-zero stiffness vibration isolator, comprising: a base, a movable frame, and four bearing blocks of the same structure rotatably arranged therein, wherein: one side of each bearing block is rotatably connected to the movable frame or the base, the other side is connected to the adjacent bearing block, and the third side thereof and the adjacent bearing block repel each other through magnetic force, thereby making the movable frame a single-degree-of-freedom motion mode, allowing up and down compression and stretching, and the entire device realizes nonlinear displacement coupling of positive and negative stiffness magnetic groups.

[0006] Two adjacent side surfaces of the bearing block are each provided with a pair of magnetic components, which are respectively used to provide repulsive forces to the bearing blocks on the adjacent sides.

[0007] Technical Effects

[0008] The present invention utilizes the geometric nonlinearity of the paper-kirigami structure to convert the nonlinear magnetic repulsion of the vertically opposed magnet groups into hardened positive stiffness, and the magnetic repulsion of the horizontally opposed magnet groups into negative stiffness. This mechanical conversion capability stems from the nonlinear evolution of the internal geometric configuration of the paper-kirigami unit when it is deformed by force, resulting in nonlinear modulation of the force transmission path and effective effect. Compared with the existing technology, the present invention achieves a wide quasi-zero stiffness region in a compact space and exhibits excellent low-frequency vibration isolation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic diagram of the present invention;

[0010] Figure 2 It is a schematic diagram of the structure of the present invention;

[0011] In the figure: 1 base, 2 bearing block, 3 movable platform, 4 magnetic component, 5 hinge;

[0012] Figure 3 This is the principle diagram of quasi-zero stiffness variable load modulation of the basic vibration isolation unit;

[0013] Figure 4 This is the vibration isolation performance test result of the basic vibration isolation unit under random frequency excitation. DETAILED DESCRIPTION

[0014] like Figure 1 and Figure 2 As shown, this embodiment relates to a magnetically embedded paper-kirigami-type quasi-zero stiffness vibration isolator, comprising: a base 1, a movable frame 3, and four bearing blocks 2 of the same structure rotatably arranged therein, wherein: one side of each bearing block 2 is rotatably connected to the movable frame 3 or the base 1, and the other side is connected to the adjacent bearing block, and the third side thereof and the adjacent bearing block repel each other through magnetic force, so that the movable frame 3 is a single-degree-of-freedom motion mode, allowing up and down compression and stretching and the entire device realizes nonlinear displacement coupling of positive and negative stiffness magnetic groups.

[0015] Two adjacent side surfaces of the bearing block 2 are each provided with a pair of magnetic components 4, which are respectively used to provide repulsive forces to the bearing blocks on the adjacent sides.

[0016] The adjacent side surfaces are respectively provided with embedded grooves for placing magnetic components.

[0017] The magnetic component adopts but is not limited to natural magnets.

[0018] The rotation connection is achieved through a hinge 5, the fulcrum of the hinge 5 is on the same horizontal line as the center of the magnet, ensuring the positive transmission of the repulsive force of the magnet.

[0019] like Figure 3 As shown, this embodiment relates to a quasi-zero stiffness vibration isolation method based on the above-mentioned device: when the movable platform is subjected to a downward load, the vibration isolation structure as a whole is compressed, the distance between the magnets decreases, and the repulsive magnetic force increases accordingly. For two pairs of magnets placed horizontally opposite each other, as the system is compressed in the second half, their repulsive force in the vertical direction gradually weakens, and eventually the repulsive force is completely in the horizontal direction, that is, no component force is generated in the vertical direction, showing a negative stiffness characteristic. For two pairs of magnets placed vertically opposite each other, as the system is compressed, the vertical component of the repulsive force continues to increase, showing a gradually hardening positive stiffness characteristic.

[0020] As shown in Table 1, some negative stiffness characteristic test data

[0021] Table 1

[0022] As shown in Table 2, some positive stiffness characteristic test data

[0023] Table 2

[0024] Before the system reaches a quasi-zero stiffness state, the positive stiffness of the isolator is dominated by the repulsive force generated by the four pairs of magnets. As the system is compressed, the two pairs of horizontally opposed magnets exhibit negative stiffness, while the two pairs of vertically opposed magnets produce positive stiffness, which offsets the negative stiffness, thereby achieving a quasi-zero stiffness state. As the system continues to be compressed, the repulsive force and stiffness generated by the two vertically opposed pairs of magnets continue to increase, while the vertical force of the two horizontally opposed pairs of magnets gradually weakens, causing the entire system to exhibit a hardened positive stiffness characteristic. By reasonably adjusting the spacing of the load-bearing components and the specifications of the magnets, the changes in positive and negative stiffness can be controlled, thereby achieving a customized design of the quasi-zero stiffness curve.

[0025] The adjustment is specifically as follows: fixing the diameter of the mutually repelling magnet group that provides negative stiffness, and systematically changing the magnet diameter of the vertically opposed magnet group that provides positive stiffness. When the force-displacement curve shows a gentle slope within a fairly wide displacement range, the entire system achieves an effective quasi-zero stiffness characteristic.

[0026] As shown in Table 3, some quasi-zero stiffness test data

[0027] Table 3

[0028] To verify the kirigami structure's ability to convert magnetic repulsion, the aforementioned method was run using a universal testing system. Pneumatic clamps were placed on the base and mobile platform to constrain horizontal displacement. Displacement loading was employed at a constant loading rate of 5 mm / min, with the loading force measured by a high-precision sensor. The results showed that the vibration isolation system exhibited a broad quasi-zero stiffness region.

[0029] like Figure 4 The following table shows the actual vibration isolation effect of this embodiment. The vibration isolation load was 1 kg, and the base was subjected to random frequency excitation with a frequency range of 0 to 20 Hz and an amplitude of 2 mm. Some of the data are shown in Table 4. During the test, the acceleration of the base was significantly greater than that of the movable platform, demonstrating that the basic vibration isolation unit can effectively suppress the transmission of vibration from the base to the platform.

[0030] Table 4

[0031] Compared with the existing technology, this device achieves a wide quasi-zero stiffness area in a compact space and exhibits excellent low-frequency vibration isolation performance.

[0032] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principles and purpose of the present invention. The scope of protection of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. All implementation schemes within its scope shall be subject to the constraints of the present invention.

Claims

1. A magnetic embedded paper-kirigami quasi-zero stiffness vibration isolator, characterized in that: include: A base, a movable frame, and four identically structured bearing blocks rotatably disposed therein, wherein: one side of each bearing block is rotatably connected to the movable frame or the base, the other side is connected to an adjacent bearing block, and the third side thereof and the adjacent bearing block are mutually repelled by magnetic force, thereby enabling the movable frame to have a single degree of freedom motion mode, allowing for up and down compression and extension, and the entire device to achieve nonlinear displacement coupling of positive and negative stiffness magnetic groups; Two adjacent side surfaces of the bearing block are each provided with a pair of magnetic components, which are respectively used to provide repulsive forces to the bearing blocks on the adjacent sides.

2. The magnetic embedded paper-kirigami quasi-zero stiffness vibration isolator according to claim 1 is characterized in that: The adjacent side surfaces are respectively provided with embedded grooves for placing magnetic components.

3. The magnetic embedded paper-kirigami quasi-zero stiffness vibration isolator according to claim 1 is characterized in that: The rotation connection is achieved through a hinge, the fulcrum of the hinge is on the same horizontal line as the center of the magnet, ensuring the positive transmission of the repulsive force of the magnet.

4. A quasi-zero stiffness vibration isolation method based on the device according to any one of claims 1 to 3, characterized in that: When the movable frame is subjected to a downward load, the entire vibration isolation structure compresses, the distance between the magnets decreases, and the repulsive magnetic force increases. For two pairs of magnets placed horizontally, as the system compresses in the second half, their vertical repulsive force gradually weakens, and eventually the repulsive force is completely horizontal, that is, no vertical component is generated, showing a negative stiffness characteristic. For two pairs of magnets placed vertically, as the system compresses, the vertical component of the repulsive force continues to increase, showing a gradually hardening positive stiffness characteristic. Before the movable frame reaches the quasi-zero stiffness state, the positive stiffness of the isolator is dominated by the repulsive force generated by the four pairs of magnets. As the system is compressed, the two horizontally opposing pairs of magnets exhibit negative stiffness, while the two vertically opposing pairs of magnets generate positive stiffness, which offsets the negative stiffness, thereby achieving a quasi-zero stiffness state. As the system continues to be compressed, the repulsive force and stiffness generated by the two vertically opposing pairs of magnets continue to increase, while the vertical force of the two horizontally opposing pairs of magnets gradually weakens, causing the entire system to exhibit a hardened positive stiffness characteristic.

5. The quasi-zero stiffness vibration isolation method according to claim 4, characterized in that: The adjustment is specifically as follows: fixing the diameter of the mutually repelling magnet group that provides negative stiffness, and systematically changing the magnet diameter of the vertically opposed magnet group that provides positive stiffness. When the force-displacement curve shows a gentle slope within a fairly wide displacement range, the entire system achieves an effective quasi-zero stiffness characteristic.

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