A double-helix type low-frequency vibration absorber

Abstract

The present invention discloses a double - helix type low - frequency vibration absorption device, which includes a central mass body, a constraint frame and a carving plate; two slits spiraling in opposite directions are engraved on the carving plate, so as to form a double - helix beam structure on the carving plate. The central mass body is arranged at the center of the carving plate and used to connect the two double - helix beam structures. The constraint frame is arranged in the circumferential direction of the carving plate and used to provide end constraints for the double - helix beam structures. In addition, by introducing partition pins into the double - helix beam structures, the double - helix beam structures are divided into multiple segments according to different length ratios between the pins to the central mass body and the constraint frame, and the effective stiffness of the vibration absorption device is adjusted, thereby realizing the adjustment of the vibration absorption frequency band. Compared with the existing local resonance vibration absorption units, the vibration absorption device of the present invention has a lower vibration absorption frequency band, a wider and adjustable band - gap frequency range, and more excellent structural performance, and can be widely applied to the low - frequency vibration absorption of various devices in various environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of damping and vibration absorption, and particularly relates to a double - helix type low - frequency vibration absorption device. Background Technique

[0002] Vibration absorption is a commonly used approach in vibration attenuation measures. By adding a subsystem with the same resonance frequency to the main system, the vibration energy is transferred and consumed, thereby achieving the effect of absorbing the vibration of the main system. According to whether external energy is introduced into the vibration absorption system, it can be divided into active vibration absorption technology, passive vibration absorption technology, and hybrid vibration absorption technology. Among them, traditional vibration absorption technology mainly relies on dynamic vibration absorbers (DVA). By utilizing the resonant characteristics of the additional sub - structure, the conversion and consumption of energy are realized. However, although traditional dynamic vibration absorbers can achieve low - frequency vibration attenuation to a certain extent, it is difficult to effectively attenuate low - frequency vibration through a lightweight and small - size structure, and a large additional weight and installation space are required. In addition, the working frequency band of traditional dynamic vibration absorbers is narrow, and it is difficult to meet the needs of broadband vibration suppression. Acoustic metamaterials have been a hot research topic in many fields such as acoustics, mechanics, machinery, civil engineering, and aerospace since the 21st century, providing a new approach to realize low - frequency vibration absorption technology through artificial micro - structures with sub - wavelength sizes.

[0003] Although the previously proposed local resonance vibration absorption units can obtain a certain vibration absorption bandwidth, it is difficult to balance the requirements of high environmental adaptability and deep sub - wavelength while achieving low - frequency vibration absorption. That is, for non - metallic material local resonance units, it is difficult to match the harsh working environment and the durability is poor; while for metal material local resonance units, the spatial size is often large, which is significantly limited in engineering applications. In addition, as a passive vibration absorption method, local resonance - type acoustic metamaterials can only fixedly absorb vibrations in a certain frequency range. For vibrations outside the target frequency, the vibration absorption units need to be redesigned and manufactured. In fact, from the existing frequency band adjustment methods of acoustic metamaterials, the control means are relatively complex. Therefore, new damping and vibration absorption technologies need to be developed to achieve local resonance damping and vibration absorption performance in a wider frequency band and lower frequency range, and to actively adjust the vibration absorption frequency band within a relatively wide frequency band. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the existing vibration absorption technology, and provide a double - helix type low - frequency vibration absorption device for achieving local resonance damping and vibration absorption performance in a wider frequency band and lower frequency range, and actively adjusting the vibration absorption frequency band within a relatively wide frequency band.

[0005] The present invention is implemented by adopting the following technical solutions:

[0006] A double - helix type low - frequency vibration absorption device includes a central mass body, a constraint frame, and an engraved plate;

[0007] Two slits spiraling in opposite directions are engraved on the engraving plate, so as to form a double - helix beam structure on the engraving plate. The central mass body is arranged at the center of the engraving plate and is used to connect the two double - helix beam structures. The constraint frame is arranged in the circumferential direction of the engraving plate and is used to provide end constraints for the double - helix beam structures.

[0008] A further improvement of the present invention lies in that the double - helix beam structure satisfies the parametric equation:

[0009] where R is the radius of the central mass body, is the rotation angle of the spiral beam, t is the width of the spiral beam, and α is the shrinkage rate of the spiral beam.

[0010] A further improvement of the present invention lies in that by reducing the width and thickness of the double - helix beam structure, or increasing the number of turns and shrinkage rate of the double - helix beam structure, the vibration absorption frequency is reduced.

[0011] A further improvement of the present invention lies in that by increasing the weight of the central mass body, the vibration absorption frequency is reduced.

[0012] A further improvement of the present invention lies in that the device is made of metal materials.

[0013] A further improvement of the present invention lies in that it further includes a plug pin, which is separated in the double - helix beam structure and is used to divide the double - helix beam structure into multiple segments according to different length ratios between the plug pin and the central mass body and the constraint frame, so as to adjust the effective stiffness of the vibration absorption device, thereby realizing the adjustment of the vibration absorption frequency band.

[0014] A further improvement of the present invention lies in that the plug pin is made of the same material as the engraving plate.

[0015] A further improvement of the present invention lies in that by setting jacks at different angular positions on both sides of the double - helix beam structure and inserting the plug pin to separate the double - helix beam structure, continuous adjustment of the vibration absorption frequency band can be realized within a wide frequency band, and tunable design of the vibration absorption device can be achieved.

[0016] The present invention has at least the following beneficial technical effects:

[0017] 1. Through the design of the spiral beam structure, the vibration absorption frequency can be reduced to several Hz, and it can be widely applied to low - frequency vibration reduction and noise reduction of various equipment and instruments such as airplanes, high - speed rails, automobiles, and ships;

[0018] 2. Through the design of the spiral beam structure, the slender beam - shaped structure with low stiffness is compressed into a small size space, which can be widely adapted to various narrow application spaces and has the advantages of high space adaptability and deep sub - wavelength;

[0019] 3. Through the double - helix beam structure design, it is possible to avoid the asymmetric deformation of the beam under the action of the self - weight of the mass block, and it has better stability compared with the ordinary cantilever beam structure and single - helix structure;

[0020] 4. There are many available design parameters. By changing the width, thickness, number of turns, shrinkage rate of the helical beam, or the weight of the central mass body, the adjustment of the vibration absorption frequency can be achieved;

[0021] 5. Through the pure - metal structure design, it can adapt to harsh working environments such as high and low temperatures and radiation, and has the advantage of high environmental adaptability. It can be applied to situations where conventional damping materials and vibration absorption devices are not applicable;

[0022] 6. The total weight of the vibration absorption device is reduced to less than 1% of the main structure, and it has excellent lightweight characteristics;

[0023] 7. Through the adjustable design, the vibration absorption frequency band can be effectively changed by attaching accessories to the original vibration absorption structure. The adjustable range reaches more than 5 times, and the vibration attenuation effect is good within the adjustable range of the band gap, which can meet the requirements of broadband and high - efficiency vibration absorption.

[0024] In summary, according to the above characteristics of a double - helix type low - frequency vibration absorption device provided by the present invention, by using the low - frequency broadband vibration absorption device provided by the present invention, it is possible to achieve the local resonance damping vibration absorption performance in a wider frequency band and lower frequency range, and actively adjust the vibration absorption frequency band within a relatively wide frequency band. This device adopts a helical beam structure, effectively compresses the slender beam structure with low - stiffness characteristics in a smaller space size, thereby achieving a lower - frequency vibration absorption effect with both high space adaptability and deep sub - wavelength; and by dividing the helical beam into two segments with different length ratios, the effective stiffness of the local resonance unit is adjusted, so as to realize the tunable design of the vibration absorption frequency band and achieve the broadband vibration absorption effect. The advantages of this device include not only high space adaptability, deep sub - wavelength and tunable low - frequency broadband vibration absorption, but also good stability, many design parameters, high environmental adaptability, and small additional mass. Among them, good stability is reflected in that it can avoid the asymmetric deformation of the beam under the action of the self - weight of the mass block; many design parameters are reflected in that the width, thickness, number of turns, shrinkage rate of the helical beam and the weight of the central mass body can all be changed arbitrarily; high environmental adaptability is reflected in that a pure - metal structure can be adopted to adapt to harsh working environments such as high and low temperatures and radiation; small additional mass is reflected in that the additional mass is less than 1% of the main structure, but it can achieve the broadband and high - efficiency vibration absorption effect and make the adjustable range reach more than 5 times. In summary, compared with the existing local resonance vibration absorption units, this vibration absorption device has a lower vibration absorption frequency band, a wider and adjustable band - gap frequency range, and more excellent structural performance, and can be widely applied to the low - frequency vibration absorption of various devices in various environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1Schematic diagram of the double - helix local resonance unit structure;

[0026] Figure 2 is Figure 1 the top - view;

[0027] Figure 3 is Figure 1 the side - view;

[0028] Figure 4 In (a) is the calculation result of the energy band structure of the double - helix local resonance unit;

[0029] Figure 4 In (b) is the projection diagram of the calculation result of the normalized out - of - plane modal displacement of the double - helix local resonance unit;

[0030] Figure 5 In (a) is the influence relationship diagram of the upper and lower bandgap boundaries and bandwidth of the double - helix local resonance unit with the rotation angle of the helical beam;

[0031] Figure 5 In (b) is the influence relationship diagram of the upper and lower bandgap boundaries and bandwidth of the double - helix local resonance unit with the width of the double - helix beam;

[0032] Figure 5 In (c) is the influence relationship diagram of the upper and lower bandgap boundaries and bandwidth of the double - helix local resonance unit with the shrinkage rate of the double - helix beam;

[0033] Figure 6 In (a) is the schematic diagram of the structure of the second - group double - helix local resonance unit;

[0034] Figure 6 In (b) is the calculation result of the energy band structure of the second - group double - helix local resonance unit;

[0035] Figure 7 In (a) is the calculation result of the transmission curve of the double - helix local resonance unit S1;

[0036] Figure 7 In (b) is the calculation result of the transmission curve of the double - helix local resonance unit S2;

[0037] Figure 8 In (a) is the measurement result of the normalized vibration frequency response function of the steel plate with the additional double - helix local resonance unit S1;

[0038] Figure 8 In (b) is the measurement result of the normalized vibration frequency response function of the steel plate with the additional double - helix local resonance unit S2;

[0039] Figure 9 Schematic diagram of the adjustable double - helix local resonance unit structure;

[0040] Figure 10 is Figure 9 the top view of;

[0041] Figure 11 is the structural schematic diagram of the bolt;

[0042] Figure 12 In (a), it is the calculation result of the energy band structure after arranging the bolt holes in the double - helix local resonance unit S1;

[0043] Figure 12 In (b), it is the projection diagram of the calculation result of the normalized out - of - plane modal displacement after arranging the bolt holes in the double - helix local resonance unit S1;

[0044] Figure 13 In (a), it is the calculation result of the energy band structure after arranging the bolt in the S1 vibration absorption unit at 0°;

[0045] Figure 13 In (b), it is the calculation result of the energy band structure after arranging the bolt in the S1 vibration absorption unit at 40°;

[0046] Figure 13 In (c), it is the calculation result of the energy band structure after arranging the bolt in the S1 vibration absorption unit at 70°;

[0047] Figure 13 In (d), it is the calculation result of the energy band structure after arranging the bolt in the S1 vibration absorption unit at 80°;

[0048] Figure 14 is the influence relationship diagram of the upper and lower boundaries and bandwidth of the bandgap of the adjustable double - helix local resonance unit and the bolt arrangement position;

[0049] Figure 15 is the calculation diagram of the transmission curve of the adjustable double - helix local resonance unit. Specific implementation manners

[0050] Next, in combination with the relevant calculation and measurement results of the embodiments of the present invention in the attached drawings, the technical solutions in the embodiments of the present invention will be described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0051] A double - helix low - frequency vibration absorber provided by the present invention includes a central mass body 1, a constraint frame 2, an engraved plate 3, and a pin 5. Two slits spiraling in opposite directions are engraved on the engraved plate 3, so as to form a double - helix beam structure 4 on the engraved plate 3. The central mass body 1 is arranged at the center of the engraved plate 3 and is used to connect the two double - helix beam structures 4. The constraint frame 2 is arranged in the circumferential direction of the engraved plate 3 and is used to provide end constraints for the double - helix beam structure 4. The pin 5 is separated in the double - helix beam structure 4 and is used to divide the double - helix beam structure 4 into multiple segments according to different length ratios between the pin 5 and the central mass body 1 and the constraint frame 2, and adjust the effective stiffness of the vibration absorber, thereby realizing the adjustment of the vibration absorption frequency band.

[0052] Embodiment

[0053] (1) Design and parameter influence of double - helix local resonance unit

[0054] As an implementation case, a steel plate with dimensions of 500mm×500mm×3mm is selected as the target vibration - damping structure. Through vibration tests, the target vibration absorption frequencies of the low - frequency oscillators are determined to be 77Hz and 169Hz. According to the law of influence of structural parameters, a double - helix cell structure is designed.

[0055] As shown in the appendix Figure 1 The double - helix low - frequency vibration absorber is composed of a constraint frame, an engraved plate, and a central mass body. Among them, a double - helix beam structure is engraved on the engraved plate, and the geometric characteristics of the double - helix beam structure are determined by parametric equations: The constraint frame and the engraved plate are made of aluminum material, and the central mass body is made of stainless - steel material. The specific structural parameters are: lattice constant A = 50mm, engraved plate thickness T = 1.5mm, central mass body radius R = 10mm, central mass body height H = 8.5mm, constraint frame width L = 3mm, constraint frame thickness B = 4mm, rotation angle of the double - helix beam structure width of the double - helix beam structure t = 2mm, shrinkage rate of the double - helix beam structure α = 1. The calculated energy band diagram and normalized out - of - plane modal displacement diagram of the S1 local resonance unit are as shown in the appendix Figure 4 It can be seen that the double - helix local resonance unit generates a bending wave bandgap with a bandwidth of 32.4Hz in the frequency range of 65.9 - 98.3Hz, which can absorb the out - of - plane vibration mode. The bandgap width is significantly improved compared with the previously proposed local resonance vibration absorption units, and is nearly twice the bandwidth of the common silica - based thin - plate vibration absorption units. While maintaining the low - frequency band, a wide - band vibration absorption effect is achieved. In addition, it can be seen that although a pure metal material is used for the low - frequency band design, the vibration absorption unit can still maintain a small spatial size, fully reflecting the deep sub - wavelength property of the double - helix local resonance unit.

[0056] Using the commercial finite element software COMSOL, the influence of structural parameters on the upper and lower boundaries and bandwidth of the unit bandgap in the double - helix local resonance unit was calculated. As shown in the appendix Figure 5 (a), as the rotation angle of the double - helix beam structure increases, the upper and lower boundaries of the bandgap decrease in a concave curve, and the bandwidth first increases and then decreases; as shown in the appendix Figure 5 (b), as the width t of the double - helix beam structure increases, the upper and lower boundaries of the bandgap and the bandwidth decrease linearly; as shown in the appendix Figure 5 (c), as the shrinkage rate α of the double - helix beam structure increases, the upper and lower boundaries of the bandgap first decrease linearly with a smaller slope and then decrease linearly with a larger slope. From the perspective of low - frequency vibration absorption, the increase in the rotation angle of the double - helix beam structure, the increase in width t, and the increase in shrinkage rate α are beneficial to further reducing the bandgap frequency range of the local resonance unit.

[0057] (2) Verification of the vibration absorption effect of the double - helix local resonance unit

[0058] According to the influence relationship of structural parameters, a second group of double - helix local resonance units S2 was designed for the target frequency of 169 Hz. As shown in the appendix Figure 6 (a), the specific structural parameters are: A = 50 mm, T = 1.5 mm, R = 7.5 mm, H = 8.5 mm, L = 3 mm, B = 4 mm, t = 2 mm, α = 1. The calculated energy band diagram is shown in the appendix Figure 6 (b). It can be seen that the S2 local resonance unit generates a flexural wave bandgap in the frequency range of 145.7 - 187.7 Hz, with a bandwidth of 42 Hz, and the target vibration absorption frequency of 169 Hz falls within the bandgap frequency range and is near the center frequency of the bandgap.

[0059] The transmission curves of the designed local resonance units S1 and S2 were calculated using finite element software, and the calculated result curves are shown in the appendix Figure 7 . It can be seen that for the vibration absorption unit S1, in the bandgap frequency range of 66.0 - 98.0 Hz (approx.), the average attenuation rate of the vibration signal reaches 29.7 dB; for the vibration absorption unit S2, in the bandgap frequency range of 146.0 - 188.0 Hz (approx.), the average attenuation rate of the vibration signal is 24.4 dB, and the transmission vibration reduction effect is excellent.

[0060] Through vibration test, the attenuation effect of the double - helix local resonance unit on the target frequency of the target vibration absorption object was verified. The normalized frequency response function curve obtained from the experiment is as Figure 8As shown, it can be seen that although the double - helix vibration - absorption units S1 and S2 weigh only 39.45 g and 30.31 g respectively, while the steel plate weighs 5.9 kg, and the total mass of the unit cell is only 0.67% and 0.51% of the mass of the steel plate, the vibration - absorption effect is good. Under the action of the vibration - absorption unit S1, the attenuation rate of the target frequency of 77 Hz reaches 78.5%; under the action of the vibration - absorption unit S2, the vibration - absorption effect of the target frequency of 169 Hz reaches 98.6%. At the same time, the vibration peaks in the frequency range of 20 - 200 Hz are all attenuated to a certain extent.

[0061] (III) Adjustable design of the double - helix local - resonance unit

[0062] In the present invention, by adjusting the effective stiffness of the local - resonance unit, the adjustment of the frequency band of the vibration - absorption unit is realized. Specifically, as shown in the appendix Figures 9 to 11 By introducing a partition pin into the double - helix beam structure, the double - helix beam structure is divided into two segments according to different length ratios of the pin between the central mass body and the constraint frame to adjust the effective stiffness of the vibration - absorption device and realize the adjustable design of the double - helix vibration - absorption unit. Here, taking the design of the local - resonance unit S1 as an example, the adjustable effect of the band gap of the local - resonance unit is analyzed and explained.

[0063] Holes are arranged at a certain angle on both sides of the double - helix beam structure for the S1 local - resonance unit. Different angles determine different length ratios of the pin between the central mass body and the constraint frame when arranging the pin. The band gap of the vibration - absorption unit after arranging the holes is calculated by COMSOL. As shown in the appendix Figure 12 It can be seen that the bending - wave band gap decreases from 65.9 - 98.3 Hz when no holes are arranged to 62.8 - 93.8 Hz. The upper and lower boundary frequencies of the band gap both decrease to a certain extent, but the target vibration - absorption frequency of 77 Hz still falls within the band - gap frequency range and is near the central frequency of the band gap.

[0064] Aluminum pins are arranged on the holes in turn, and the arrangement angles are 0°, 40°, 70°, and 80° respectively. The band gap of the local - resonance unit after adjustment at different angles is calculated. As shown in the appendix Figure 13 It can be seen that after arranging the pin at 0° for the S1 vibration - absorption unit, the band gap moves from 62.8 - 93.8 Hz when no pin is arranged to 79.6 - 119.1 Hz; when the pin is arranged at 40° of the double - helix beam structure, the unit band gap is 112.6 - 168.2 Hz; when arranged at 70° of the double - helix beam structure, the band gap is 163.7 - 211.0 Hz; when continuously increasing the angle of the arrangement point, when the pin is located at 80° of the double - helix beam structure, the unit band gap moves to 198.0 - 234.3 Hz, realizing the adjustable effect of the band gap of the local - resonance unit. The specific curves of the upper and lower boundaries and the bandwidth of the band gap are shown in the appendix Figure 14As shown. It can be seen that within a certain range, as the angle of the pin arrangement increases, the band gap gradually increases, and the bandwidth first increases and then decreases. Based on this, the benefit of changing the effective stiffness of the resonant unit to adjust the band gap is obvious. Under the adjustment of the pin, the band gap of the vibration absorption unit S1 is expanded from the initial 65.9-98.3Hz to 62.8-234.3Hz, and the bandwidth is expanded from 32.4Hz to 171.5Hz, an increase of 5.3 times, achieving an excellent vibration absorption band continuous adjustment effect in a wider frequency band. Not only is the bandwidth further expanded on the basis of the wide bandwidth of the double helix local resonance unit, but the unit can be redesigned to cover new target vibration absorption frequencies, achieving a tunable design of the vibration absorption device.

[0065] (IV) Verification of the transmission effect of the adjustable double helix local resonance unit

[0066] Next, the transmission effect of the adjustable double helix local resonance unit needs to be verified to better illustrate the efficient broadband adjustable vibration absorption effect of the double helix unit. Here, the double helix local resonance unit A1 when the pin is not arranged and the double helix local resonance unit A2 with the pin arranged at 70° in the double helix beam structure are selected to calculate the transmission curve. Among them, the band gap of the vibration absorption unit A1 is 62.8-93.8Hz, and the band gap of the vibration absorption unit A2 is 163.7-211.0Hz.

[0067] The calculated transfer curve is shown in the attached figure. Figure 15 As shown, it can be seen that under the action of the adjustable double-helix local resonance units A1 and A2, the transmission effects are completely different. When the vibration absorption unit A1 is arranged, the average vibration attenuation rate reaches 35.3dB in the band gap range of 63.0-94.0Hz (approximately); when the vibration absorption unit A2 is arranged, the average vibration attenuation rate reaches 44.6dB in the band gap range of 163.5-211.0Hz (approximately). This shows that, on the one hand, under the regulation of the pin, the band gap of the double-helix local resonance unit can be moved to achieve the effect of adjustable band gap, expanding the band gap use frequency range of the vibration absorption unit; on the other hand, under the influence of the wide-band gap, the adjustable double-helix structure has a vibration attenuation rate of more than 35dB, achieving a high-efficiency vibration absorption effect.

[0068] According to the above data, it can be seen that the technical effects that the present invention can achieve are as follows:

[0069] 1. Through the double helical beam structure design, the vibration absorption frequency can be reduced to several Hz, which can be widely used in low-frequency vibration and noise reduction of various equipment and instruments such as aircraft, high-speed railways, automobiles, and ships;

[0070] 2. Through the design of the double-helix beam structure, the slender beam structure with low stiffness is compressed into a smaller size space, which can widely adapt to various narrow application spaces and has the advantages of high space adaptability and deep sub-wavelength.

[0071] 3. Through the design of the double-helix beam structure, the non-symmetric deformation of the beam caused by the self-weight of the mass block can be avoided, and it has better stability than the ordinary cantilever beam structure and single-helix structure.

[0072] 4. There are many design parameters available. By changing the width and thickness of the double-helix beam structure, the number of turns and shrinkage rate of the double-helix beam structure, or the weight of the central mass body, the adjustment of the vibration absorption frequency can be achieved.

[0073] 5. Through the design of the pure metal structure, it can adapt to harsh working environments such as high and low temperatures and radiation, and has the advantage of high environmental adaptability. It can be applied to situations where conventional damping materials and vibration absorption devices are not applicable.

[0074] 6. The total weight of the vibration absorption device is reduced to less than 1% of the main structure, and it has excellent lightweight characteristics.

[0075] 7. Through the adjustable design, the vibration absorption frequency band can be effectively changed by attaching accessories to the original vibration absorption structure. The adjustable range reaches more than 5 times, and the vibration attenuation effect is good within the adjustable bandgap, which can meet the broadband and high-efficiency vibration absorption requirements.

[0076] In summary, according to the above characteristics of a double - helix low - frequency vibration absorption device provided by the present invention, by using the low - frequency broadband vibration absorption device provided by the present invention, the local resonance damping vibration absorption performance in a wider frequency band and lower frequency range can be achieved, and the active tunability of the vibration absorption frequency band can be realized within a relatively wide frequency band. This device adopts a spiral beam structure, effectively compresses the slender beam structure with low - stiffness characteristics within a small space size, thereby achieving a lower - frequency vibration absorption effect with both high spatial adaptability and deep sub - wavelength characteristics; and by dividing the spiral beam into two segments with different length ratios, the effective stiffness of the local resonance unit is adjusted, so as to realize the tunable design of the vibration absorption frequency band and achieve the broadband vibration absorption effect. The advantages of this device include not only high spatial adaptability, deep sub - wavelength and tunable low - frequency broadband vibration absorption, but also good stability, many designable parameters, high environmental adaptability, small additional mass, etc. Among them, good stability is reflected in that it can avoid the asymmetric deformation of the beam under the action of the self - weight of the mass block; many designable parameters are reflected in that the width, thickness, number of turns, shrinkage rate of the double - helix beam structure and the weight of the central mass body can be arbitrarily changed; high environmental adaptability is reflected in that a pure - metal structure can be adopted to adapt to harsh working environments such as high and low temperatures and radiation; small additional mass is reflected in that the additional mass is less than 1% of the main structure, but it can achieve the broadband and high - efficiency vibration absorption effect and make the adjustable range reach more than 5 times. In summary, compared with the existing local resonance vibration absorption units, this vibration absorption device has a lower vibration absorption frequency band, a wider and adjustable band - gap frequency range, and more excellent structural performance, and can be widely applied to the low - frequency vibration absorption of various devices in various environments.

Claims

1. A double - helix type low - frequency vibration absorption device, characterized in that, It includes a central mass body (1), a restraint frame (2), a carving plate (3) and a pin (5); Two slits spiraling in opposite directions are engraved on the carving plate (3), so as to form a double-helix beam structure (4) on the carving plate (3). The central mass body (1) is arranged at the center of the carving plate (3) and used to connect the two double-helix beam structures (4). The restraint frame (2) is arranged in the circumferential direction of the carving plate (3) and used to provide end restraint for the double-helix beam structure (4); The double - helix beam structure (4) satisfies the parametric equation: where R is the radius of the central mass body, is the rotation angle of the spiral beam, t is the width of the spiral beam, and α is the shrinkage rate of the spiral beam; The pins (5) are separated in the double-helix beam structure (4) and used to divide the double-helix beam structure (4) into multiple segments according to different length ratios between the pins (5) to the central mass body (1) and the restraint frame (2), and adjust the effective stiffness of the vibration absorber, so as to realize the adjustment of the vibration absorption frequency band.

2. The double-helix type low-frequency vibration absorber according to claim 1, wherein By reducing the width and thickness of the double-helix beam structure (4), or increasing the number of turns and shrinkage rate of the double-helix beam structure (4), the vibration absorption frequency is reduced.

3. A double-helix low-frequency vibration absorption device according to claim 1, characterized in that, By increasing the weight of the central mass body (1), the vibration absorption frequency is reduced.

4. A double-helix low-frequency vibration absorption device according to claim 1, characterized in that, This device is made of metal materials.

5. A double-helix type low-frequency vibration absorption device according to claim 1, characterized in that, The pins (5) are made of the same material as the carving plate (3).

6. A double-helix low-frequency vibration absorption device according to claim 1, characterized in that, By arranging jacks at different angular positions on both sides of the double-helix beam structure (4) and inserting the pins (5) to separate the double-helix beam structure (4), continuous adjustment of the vibration absorption frequency band can be realized within a wide frequency band, and tunable design of the vibration absorber can be realized.

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