A vibration damping pedestal
By setting an acoustic black hole structure and a vibration damping oscillator on the vibration damping platform, the problem of poor vibration damping and noise reduction effect of the acoustic black hole structure in the low frequency range was solved, and a vibration damping effect in a wider frequency range was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN ENG UNIV
- Filing Date
- 2024-04-03
- Publication Date
- 2026-07-21
AI Technical Summary
Existing bases for acoustic black hole structures have poor vibration reduction and noise reduction effects in the low-frequency range.
An acoustic black hole structure is set on the first plane of the vibration reduction platform, and a vibration reduction oscillator is installed on the second plane. The vibration reduction oscillator includes a cantilever structure and a mass block, and is designed to resonate at a specific frequency range. A damping layer is combined to extend the vibration reduction frequency range.
It achieves effective vibration reduction and noise reduction over a wider frequency range, improving the vibration reduction performance of the base.
Smart Images
Figure CN118066239B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vibration reduction and noise reduction technology, and in particular to the field of vibration reduction and noise reduction technology for the base of power machinery equipment. Background Technology
[0002] Vibration is inevitable during the operation of power machinery. As the main structure supporting the power equipment, the base not only supports its operation but also transmits the vibrations generated by the equipment to the foundation structure. This vibration, transmitted to the foundation, generates significant noise that negatively impacts the environment, and over time, it can also cause fatigue damage to the foundation structure.
[0003] Vibration reduction and noise reduction technologies can effectively reduce vibration and noise, thereby reducing the damage caused by vibration and noise. Vibration reduction and noise reduction technologies are mainly divided into two categories: active vibration reduction and noise reduction and passive vibration reduction and noise reduction technologies.
[0004] Active vibration damping and noise reduction technologies are relatively complex, technically challenging, and costly. Passive vibration damping and noise reduction technologies are generally simpler and less expensive. Passive vibration damping and noise reduction technologies have already been applied to engine bases, such as in Chinese invention patent application number 202210672571.4, entitled "A Diesel Engine Vibration Damping Base Based on Acoustic Black Hole Nonlinear Contact." The technical solution described in this patent application uses an acoustic black hole structure as a means of vibration damping and noise reduction in a diesel engine base.
[0005] The principle behind acoustic black hole structures is to change the structural impedance by altering the structure's thickness. This reduces the speed, shortens the wavelength, and gradually increases the amplitude of the bending waves propagating within the structure. Ideally, when the thickness of a local portion of the acoustic black hole structure decreases to zero, the speed of the bending waves also decreases to zero. Simultaneously, all the vibrational energy within the structure concentrates at that location. Damping in this energy-concentrated region dissipates the energy, thereby reducing the structure's vibration noise.
[0006] However, the acoustic black hole structure itself has a cutoff frequency, which means that the base of the acoustic black hole structure still has the problem that the vibration reduction and noise reduction effect in the low frequency range cannot meet the requirements. Summary of the Invention
[0007] To address the problem that existing acoustic black hole structure bases cannot meet the requirements for vibration reduction and noise reduction at low frequencies, this invention provides a vibration-damping base.
[0008] The technical solution of the present invention is as follows:
[0009] A vibration damping base includes a vibration damping platform. The vibration damping platform has a first plane and a second plane that is opposite to and parallel to the first plane. An acoustic black hole structure is disposed on the first plane. The acoustic black hole structure includes a circular groove. The projection of the circular groove onto the first plane is a circle. The perpendicular distance h(x) from any point on the bottom of the circular groove to the second plane conforms to the following functional relationship:
[0010] h(x) = εx m +h0
[0011] Where x is the distance from the center of the circle to the projection of the point onto the circle; h0 is the perpendicular distance from the point at the bottom of the circular groove to the second plane when the projection of the point onto the circle is the center of the circle; m is a real number greater than or equal to 2; ε is an adjustment coefficient.
[0012] A vibration damping oscillator is provided on the second plane.
[0013] Optionally, the vibration damping oscillator includes a cantilever structure with an L-shaped form, the first end of which is directly or indirectly connected to the second plane.
[0014] Optionally, a mass block is provided at the second end of the cantilever structure.
[0015] Optionally, the damping oscillator is disposed within the range of the projection of the acoustic black hole structure onto the second plane.
[0016] Optionally, the number of the damping oscillators is greater than 1.
[0017] Optionally, the damping oscillators are arranged in a 3x3 matrix; the center of the projection of the damping oscillator located at the center of the matrix onto the second plane coincides with the center of the projection of the acoustic black hole structure onto the second plane.
[0018] Optionally, the vibration damping oscillator is mounted on an oscillator carrier plate; the oscillator carrier plate is suspended on the second plane.
[0019] Optionally, the number of vibration damping platforms is greater than 1.
[0020] Optionally, at least one of the second planes of the vibration damping platform may not be provided with the vibration damping oscillator.
[0021] Optionally, a damping layer is provided on the concave inner surface of the circular groove in the acoustic black hole structure.
[0022] Optionally, the damping layer includes a first surface and a second surface; the first surface is flush with the first plane; and the second surface is fitted and matched with the recessed inner surface of the circular groove.
[0023] Optionally, it includes a vertical support plate disposed perpendicular to the first plane of the vibration damping platform.
[0024] Optionally, the acoustic black hole structure is provided on the vertical support plate.
[0025] The technical effects of this invention are as follows:
[0026] The vibration-damping base of this invention features an acoustic black hole structure (i.e., a circular groove) on the first plane of its vibration-damping platform, and a vibration-damping oscillator on the second plane of the platform. The acoustic black hole structure provides excellent vibration reduction within a certain frequency range. The vibration-damping oscillator can be configured to provide vibration reduction in frequency ranges outside the aforementioned range. Since the vibration-damping oscillator's frequency range can be pre-designed, the combination of the oscillator and the acoustic black hole structure enables the vibration-damping base of this invention to achieve vibration reduction over a wider range of vibration frequencies, thus fulfilling the objective of this invention.
[0027] The further effects of the above-mentioned alternative methods will be explained in detail below with reference to specific implementation methods. Attached Figure Description
[0028] Figure 1 This is a perspective view of one embodiment of the vibration damping base of the present invention.
[0029] Figure 2 for Figure 1 Top view of the embodiment shown.
[0030] Figure 3 for Figure 1 A cross-sectional view of an acoustic black hole structure in the illustrated embodiment.
[0031] Figure 4 for Figure 1 A perspective view of the embodiment shown from another angle.
[0032] Figure 5 for Figure 1 A perspective view of the first angle of the oscillator carrier plate in the illustrated embodiment.
[0033] Figure 6 for Figure 1 A perspective view of the second angle of the oscillator carrier plate in the illustrated embodiment.
[0034] Figure 7 for Figure 1 The comparative experimental results of the illustrated embodiment are shown in the figure.
[0035] Figure 8 This is the first experimental example of setting up a vibration damping oscillator on the oscillator carrier plate.
[0036] Figure 9The second test case involves setting up a vibration damping oscillator on the oscillator carrier plate.
[0037] Figure 10 A comparative chart of test results for an example of setting a vibration damping oscillator on an oscillator carrier plate.
[0038] Figure 11 The figure shows the comparative experimental results of a single-layer uniform base and a double-layer uniform base.
[0039] The markings in the image are explained as follows:
[0040] 101. Acoustic black hole structure; 102. Vibration damping platform; 103. Mounting hole; 104. Vibration damping platform; 105. Vertical support plate; 106. Vibrator carrier plate;
[0041] 301. Damping layer; 302. First plane; 303. Second plane;
[0042] 501. Suspension link;
[0043] 601. Vibration-damping oscillator;
[0044] 801. Second plane; 802. Vibration damping oscillator;
[0045] 901, Second plane; 902, Vibration damping oscillator. Detailed Implementation
[0046] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.
[0047] Figures 1 to 5 The specific results of one embodiment of the vibration damping base of the present invention are shown. For example... Figure 1 As shown, the vibration damping base includes a flat vibration damping platform 102. The vibration damping platform 102 has two parallel planes, namely... Figure 1 The visible plane (the plane indicated by label 102) and another plane that is opposite to and parallel to it. (See reference) Figure 3 It can be seen that these two planes are the first plane 302 and the second plane 303, respectively. Figure 1 The visible plane is the first plane 302.
[0048] like Figure 1 and Figure 3 As shown, an acoustic black hole structure 101 is disposed on the first plane 302. The acoustic black hole structure 101 is a groove structure, and the trajectory of the groove structure intersecting the first plane 302 is circular (i.e., the projection of the circular groove onto the first plane 302), that is, the acoustic black hole structure 101 is a circular groove. The perpendicular distance h(x) from the surface of the concave portion of the circular groove to the second plane 303 conforms to the following functional relationship:
[0049] h(x) = εxm +h0
[0050] Where x is the distance from the center of the circle to the projection of the point onto the circle; h0 is the perpendicular distance from the point at the bottom of the circular groove to the second plane when the projection of the point onto the circle is the center of the circle; m is a real number greater than or equal to 2; and ε is an adjustment coefficient.
[0051] like Figure 3 As shown, a damping layer 301 is provided on the inner surface of the recessed circular groove. Figure 1 and Figure 2 In the diagram, the dashed crosshairs within the circular groove represent the damping layer 301 disposed therein. The damping layer 301 is formed by filling the circular groove with damping material. The damping layer 301 has a first surface and a second surface. The first surface is... Figure 3 The upper plane of the intermediate damping layer 301 is flush with the first plane 302. The second surface is a curved surface, that is, a curved surface that conforms to the inner surface of the recessed circular groove.
[0052] like Figure 1 , Figure 2 and Figure 3 As shown, eight acoustic black hole structures 101 are arranged on the first plane 302 of the vibration damping platform 102. On the second plane 303 of the vibration damping platform 102, a vibrator carrier plate 106 is arranged corresponding to the position of each acoustic black hole structure 101. A vibration damping platform 104 parallel to the vibration damping platform 102 is also arranged on the vibration damping base. In other embodiments, the number of vibration damping platforms can be adjusted according to actual conditions. The vibration damping base also has vertical support plates 105 perpendicular to the vibration damping platform 104. Two parallel vertical support plates 105 form a group, and two groups of vertical support plates vertically form a grid structure, constituting the support structure of the vibration damping base perpendicular to the vibration damping platform 102. In other embodiments, acoustic black hole structures such as the acoustic black hole structures 101 can also be arranged on the vertical support plates.
[0053] Figure 4 Showing Figure 1 The image shows another angle view of the vibration damping base, revealing the structure of the second plane 303. (See image for details.) Figure 4 As shown, a vibrator carrier plate 106 is provided on the second plane 303 of the vibration damping platform 102. Specifically, in conjunction with... Figure 1 and Figure 2 Corresponding to the location of each acoustic black hole structure 101, a oscillator carrier plate 106 is set on the second plane 303. For example... Figure 4 As shown, no vibration damping oscillator is provided on this side of the plane of the vibration damping platform 104. In other embodiments, a vibration damping oscillator may also be provided.
[0054] Figure 5 The structure of the vibrator carrier plate 106 is shown, which is a rectangular plate with suspension rods 501 installed at each of the four corners on the same plane. The suspension rods 501 are mounted to the vibration damping platform 102 through mounting holes 103. Figure 1 and Figure 2 As shown, mounting holes 103 are provided on the outer side of the circular edge of each acoustic black hole structure 102.
[0055] Figure 6 The structure on another plane of the rectangular plate of the oscillator carrier 106 is shown. Nine damping oscillators 601 are arranged in a 3x3 matrix on this plane. The centroid of the damping oscillator 601 at the center of the 3x3 matrix coincides with the center of the acoustic black hole structure corresponding to the matrix, that is, the center of the projection of the damping oscillator on the second plane 303 coincides with the center of the projection of the acoustic black hole structure 101 on the second plane 303.
[0056] like Figure 6 As shown, the vibration damping oscillator 601 includes a rectangular elastic plate and mass blocks disposed on opposite sides of the plate, forming an L-shaped structure when viewed from the side. One mass block is fixedly connected to the surface of the oscillator carrier plate 106, while the other mass block forms a cantilever structure with the rectangular elastic plate. When subjected to external vibration, the mass block at the free end of the vibration damping oscillator 601 swings, thereby dissipating vibration energy and achieving vibration reduction and noise reduction.
[0057] The working process of this invention is as follows:
[0058] The equipment supported by the vibration damping base is mounted on the vibration damping platform 102. When the equipment vibrates, the acoustic black hole structure on the vibration damping platform 102 has a good vibration damping effect within a certain frequency range. The vibration damping oscillator, whose vibration damping frequency is pre-designed according to the equipment's vibration characteristics, can expand the vibration damping frequency range of the vibration damping base. When vibration energy is transmitted, the vibration damping oscillator generates local resonance at a specific frequency, producing a local resonance bandgap, thereby suppressing vibration and sound radiation. The vibration damping platform 104 further reduces the vibration energy, effectively reducing the vibration energy transmitted to the base plate.
[0059] To further verify the technical effects of the present invention, a simulation experiment was conducted to verify the technical solution of the present invention. The specific simulation experiment settings are as follows:
[0060] The vibration damping platform measures 75cm in length, 75cm in width, and 1cm in height; the vertical support plate measures 75cm in length, 1cm in width, and 30cm in height.
[0061] The radius of the circle projected onto the first plane of the acoustic black hole structure is 0.1m, h0 = 0.001m, and m = 2.
[0062] The vibration damping oscillator is defined with a coordinated frequency of 450Hz. The plate in the vibration damping oscillator is 3mm thick and 40mm long (i.e., the length between the two ends where the two mass blocks are located). The cross-section of the two mass blocks is a 10×10mm square.
[0063] The vibration damping base is made of steel with a density of 7800 kg / m³. 3 The Young's modulus is 210 GPa and the Poisson's ratio is 0.3.
[0064] The damping layer has a material density of 950 kg / m³, a Young's modulus of 5 GPa, and a Poisson's ratio of 0.3.
[0065] The plate in the vibration damping oscillator is made of acrylic with a density of 1190 kg / m³, a Young's modulus of 3.2 GPa, and a Poisson's ratio of 0.3.
[0066] With the centroid of the first plane as the origin, a downward harmonic force of 100N is applied at the point (0, -0.145).
[0067] Figure 7 The result is the root mean square average of the vibration acceleration response transmitted to the ground. This includes three case settings: 1. "Double-layer uniform base" refers to... Figure 1 The vibration damping base shown does not have an acoustic black hole structure or vibration damping oscillator on the vibration damping platform; 2. "Double-layer black hole base" refers to... Figure 1 The vibration damping platform of the damping base shown has a corresponding acoustic black hole structure, but no vibration damping oscillator; 3. "Double-layer black hole base + oscillator plate" refers to... Figure 1 The structure of the embodiment shown is illustrated. The curves corresponding to the names in quotation marks in the figure represent the corresponding experimental result data.
[0068] like Figure 7 As shown, comparing the data of the "double-layer uniform base" and the "double-layer black hole base", the "double-layer black hole base" is about 7dB higher than the "double-layer uniform base" at the first resonance peak near 240Hz, and 6dB lower at the second resonance near 470Hz. It has a better vibration reduction effect in multiple wide frequency bands such as 470Hz-1000Hz, 1150Hz-1500Hz, 1700-1800Hz, and 1900-3000Hz.
[0069] like Figure 7As shown, comparing the data of the "double-layer black hole base" and the "double-layer black hole base + oscillator plate", the acceleration of the "double-layer black hole base + oscillator plate" does not change at the first resonance peak of 245Hz; at the second resonance peak of 485Hz, due to the addition of the oscillator plate and the damping oscillator, the resonance peak shifts forward to 450Hz, and the amplitude decreases by 3dB; it decreases by 9dB near the third resonance peak of 615Hz; and there are multiple resonance peak amplitude reduction phenomena at frequencies above 615Hz, such as 875Hz, 1045Hz, 1125Hz, and 1210Hz, indicating that the scheme of adding the oscillator plate and the damping oscillator produces a damping effect not only in the first few resonances.
[0070] Figure 11 This demonstrates that under the same experimental conditions, the "single-layer uniform base" and... Figure 7 Comparison results of the "double-layer uniform base" in China. Figure 11 The data curve of the "double-layer uniform base" is Figure 1 The data curve of the "double-layer uniform base". Figure 11 The "single-layer uniform base" refers to, for example, Figure 1 The vibration damping base shown consists of only a top-level vibration damping platform, and this platform does not contain an acoustic black hole structure or a vibration damping oscillator. For example... Figure 11 As shown, the "double-layer uniform base" has a significant vibration reduction effect at multiple resonance peaks compared to the "single-layer uniform base". Figure 11 The data shows the vibration reduction effect of three resonance peaks, namely the vibration reduction effect formed at the resonance peaks where the data points of 7dB, 12dB and 9dB are located. Figure 11 The experimental results show that the vibration reduction effect of the "double-layer uniform base" is better than that of the "single-layer uniform base".
[0071] Simulation experiments were also conducted to verify the effect of the vibration damping oscillator arrangement on the vibration damping effect. The simulation experiments were conducted in two groups.
[0072] The specific settings are as follows:
[0073] 1. For example Figure 8 As shown, the vibration damping oscillators are arranged in a 4x4 array on the second plane, and the array is arranged within the circular area of the acoustic black hole structure projected onto the second plane.
[0074] 2. For example Figure 9 As shown, the damping oscillators are arranged in a square outside the circle projected onto the second plane of the acoustic black hole structure. Five damping oscillators are evenly spaced on the sides of the square, that is, the damping oscillators are arranged around the aforementioned circle.
[0075] Figure 10 The experimental results of the two simulation experiments are shown. The experimental results data are the root mean square average of the vibration acceleration response transmitted to the ground. Figure 10In this context, "oscillator-less black hole plate" refers to a vibration damping platform with an acoustic black hole structure but no vibration damping oscillators; "oscillator array" refers to a vibration damping platform with an acoustic black hole structure, further enhanced by an array of oscillators. Figure 8 Experimental data for vibration-damping oscillators arranged as shown; "oscillator surround" refers to the addition of an acoustic black hole structure to the vibration-damping platform. Figure 9 Experimental data for the vibration damping oscillator arranged as shown.
[0076] like Figure 10 As shown, the "oscillator-surrounded" design has a better vibration reduction effect than the "oscillatorless black hole plate," but it is significantly worse than the "oscillator array" design, indicating that... Figure 8 The vibration reduction effect of the scheme shown is better than... Figure 9 The proposed solution has good vibration reduction effect.
[0077] It is worth noting that the above description is only a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. The present invention can also be replaced by equivalent technologies. Therefore, all equivalent changes made based on the description and figures of the present invention, or direct or indirect applications to other related technical fields, are included within the scope of the present invention.
Claims
1. A vibration damping base, comprising a vibration damping platform, wherein the vibration damping platform is provided with a first plane and a second plane opposite to and parallel to the first plane, characterized in that: An acoustic black hole structure is disposed on the first plane; the acoustic black hole structure includes a circular groove; the projection of the circular groove onto the first plane is a circle; the perpendicular distance h(x) from any point on the bottom of the circular groove to the second plane conforms to the following functional relationship: h(x)=εx m +h0 Where x is the distance from the center of the circle to the projection of the point onto the circle; h0 is the perpendicular distance from the point at the bottom of the circular groove to the second plane when the projection of the point onto the circle is the center of the circle; m is a real number greater than or equal to 2; ε is an adjustment coefficient. A damping oscillator is provided on the second plane; The vibration damping oscillator includes an L-shaped cantilever structure, the first end of which is directly or indirectly connected to the second plane. A mass block is provided at the second end of the cantilever structure; The vibration damping oscillator is positioned within the projection range of the acoustic black hole structure onto the second plane; The vibration damping oscillator is mounted on the oscillator carrier plate; the oscillator carrier plate is suspended on the second plane.
2. The vibration damping base according to claim 1, characterized in that: The number of vibration damping oscillators is greater than 1.
3. The vibration damping base according to claim 2, characterized in that: The damping oscillators are arranged in a 3x3 matrix; the center of the projection of the damping oscillator located at the center of the matrix onto the second plane coincides with the center of the projection of the acoustic black hole structure onto the second plane.
4. The vibration damping base according to claim 1, characterized in that: The number of vibration reduction platforms is greater than 1.
5. The vibration damping base according to claim 4, characterized in that: At least one of the second planes of the vibration damping platform is not equipped with the vibration damping oscillator.
6. The vibration damping base according to claim 1, characterized in that: A damping layer is provided on the concave inner surface of the circular groove in the acoustic black hole structure.
7. The vibration damping base according to claim 6, characterized in that: The damping layer includes a first surface and a second surface; the first surface is flush with the first plane; and the second surface is fitted and matched with the recessed inner surface of the circular groove.
8. The vibration damping base according to claim 1, characterized in that: It includes a vertical support plate that is perpendicular to the first plane of the vibration damping platform.
9. The vibration damping base according to claim 8, characterized in that: The acoustic black hole structure is provided on the vertical support plate.