Low-frequency vibration isolation device under combined action of air spring and inerter
By using a low-frequency vibration isolation device that combines air springs and inertial capacities, the structural mass is increased by utilizing the inertial capacities, which solves the problems of reduced vertical vibration isolation stiffness and high cost of active vibration isolation, and achieves the effectiveness and real-time performance of low-frequency vibration isolation.
Patent Information
- Application Number
- CN202511090937.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-05
- Publication Date
- 2025-11-21
AI Technical Summary
Existing technologies for vertical vibration isolation suffer from reduced stiffness, leading to insufficient load-bearing capacity. Meanwhile, active vibration isolation technology is costly and carries the risk of failure, making it difficult to effectively isolate low-frequency vibrations.
A low-frequency vibration isolation device combining air springs and inertial capacitance is used. The inertial capacitance device effectively increases the structural mass while maintaining the structural stiffness. Low-frequency vibration isolation is achieved by combining the inertial container and rubber air spring.
Without changing the structural stiffness, the system frequency is reduced to achieve effective low-frequency vibration isolation, avoiding the high cost and potential failure risk of active vibration isolation, and has the advantages of real-time performance and high efficiency.
Smart Images
Figure CN120991022A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vibration isolation device technology, and in particular to a low-frequency vibration isolation device under the combined action of air spring and inertial capacitance. Background Technology
[0002] Common vibration isolation techniques for Loads at multiples of the frequency have a very good vibration isolation effect. For vertical vibration isolation, the self-weight of the structure is generally fixed. The frequency of the structure can be reduced by decreasing the stiffness. However, the reduction in stiffness leads to insufficient vertical bearing capacity. Therefore, vertical vibration isolation is more complicated than horizontal vibration isolation.
[0003] For instruments and equipment, vibration isolation is often necessary. High-frequency signals can attenuate during propagation, or vibration isolation can be achieved using traditional techniques. However, low-frequency signals still exist. To isolate low-frequency effects, a common measure is to use active vibration isolation technology. Sensors collect signals and apply an opposing force to the object being isolated to resist the external load, thereby maintaining the stability of the isolated object. Active control requires an external power source and the ability to provide accurate feedback in real time. For equipment operating for extended periods, these factors incur additional costs and also pose a risk of failure. Passive vibration isolation, with its inherent advantages such as real-time performance and the absence of an external power source, has been widely used in engineering.
[0004] Inertial capacitance is a novel structural control element with acceleration correlation at both ends. It can increase the structural mass equivalently without changing the structural mass, and increase the equivalent structural mass without changing the structural stiffness. This makes the system frequency lower than the external load frequency, thus achieving low-frequency vibration isolation.
[0005] Based on this, the present invention designs a low-frequency vibration isolation device under the combined action of air spring and inertial capacitance, which can achieve low-frequency vibration isolation. Summary of the Invention
[0006] In order to increase the equivalent structural mass through an inertial-capacitive device without changing the structural mass, and to increase the equivalent structural mass without changing the structural stiffness, thereby making the system frequency lower than the external load frequency and achieving low-frequency vibration isolation, this invention provides a low-frequency vibration isolation device under the combined action of air spring and inertial-capacitive device.
[0007] A low-frequency vibration isolation device based on the combined action of an air spring and inertial capacitance includes a rubber air spring, an outer support, a load platform, a limiting mechanism, a connecting rod, a hydraulic inertial capacitance mechanism, and a mass block. The rubber air spring is mounted on the outer support, the load platform is mounted on the top of the rubber air spring, and the mass block is placed on the load platform. Limiting mechanisms are respectively provided on both sides of the mass block. One end of the connecting rod is hinged to the outer support, the middle part of the connecting rod is hinged to the load platform, and the other end of the connecting rod is connected to the hydraulic inertial capacitance mechanism. The hydraulic inertial capacitance mechanism is fixedly connected to the outer support. The rubber air spring is connected to an auxiliary air chamber.
[0008] Furthermore, the outer support is rectangular in shape.
[0009] Furthermore, the hydraulic inertia mechanism includes a hydraulic inertia container, a piston, and a spiral tube. The piston is connected to the connecting rod and is located inside the hydraulic inertia container. The spiral tube is coiled around the outside of the hydraulic inertia container and communicates with the inside of the hydraulic inertia container.
[0010] Furthermore, the diameter of the spiral tube is 0.2cm-0.8cm.
[0011] Furthermore, the limiting mechanism includes a limiter and a limiting spring, with one end of the limiting spring connected to the load platform and the other end connected to the limiter.
[0012] Furthermore, the spring constant of the limiting spring is 1000 kN / m.
[0013] Furthermore, the limiter is made of steel.
[0014] Furthermore, the rubber air spring is connected to the additional air chamber via a throttle tube.
[0015] Furthermore, the mass block is rectangular.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: by generating an equivalent increase in structural mass through an inertial capacitance device, the equivalent structural mass is increased without changing the structural stiffness, thereby making the system frequency lower than the external load frequency and achieving low-frequency vibration isolation. Attached Figure Description
[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0018] Figure 1 This is a cross-sectional schematic diagram of a low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to an embodiment of the present invention;
[0019] Figure 2 This is a top view schematic diagram of a low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to an embodiment of the present invention;
[0020] Figure 3 This is a cross-sectional schematic diagram of the hydraulic inertial-capacitance mechanism according to an embodiment of the present invention;
[0021] Figure 4 This is a schematic diagram of the connecting rod and piston according to an embodiment of the present invention.
[0022] Explanation of reference numerals in the attached figures:
[0023] 1: Rubber air spring; 2: Rectangular external support; 3: Load platform; 4: Limiter; 5: Limit spring; 6: Connecting rod; 7: Hydraulic cylinder; 8: Piston; 9: Spiral tube; 10: Mass block; 11: Auxiliary air chamber; 12: Throttling tube. Detailed Implementation
[0024] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.
[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0027] This invention provides a low-frequency vibration isolation device based on the combined action of an air spring and inertial capacitance, comprising a rubber air spring 1, an outer support 2, a load platform 3, a limiting mechanism, a connecting rod 6, a hydraulic inertial capacitance mechanism, and a mass block 10. The outer support 2 is rectangular in shape. The rubber air spring 1 is mounted on the outer support 2, and the load platform 3 is mounted on the top of the rubber air spring 1. The mass block 10 is mounted on the load platform 3. Limiting mechanisms are provided on both sides of the mass block 10. One end of the connecting rod 6 is hinged to the outer support 2, the middle part of the connecting rod 6 is hinged to the load platform 3, and the other end of the connecting rod 6 is connected to the hydraulic inertial capacitance mechanism; the hydraulic inertial capacitance mechanism is fixedly connected to the outer support 2. The rubber air spring 1 is connected to an auxiliary air chamber 11, and the two achieve dynamic pressure balance through a throttling pipe 12.
[0028] In some preferred embodiments, the hydraulic inertia mechanism includes a hydraulic inertia container 7, a piston 8, and a spiral tube 9. The piston 8 is connected to the connecting rod 6 and is located inside the hydraulic inertia container 7. The spiral tube 9 is coiled around the outside of the hydraulic inertia container 7 and communicates with the inside of the hydraulic inertia container 7. The diameter of the spiral tube 9 is 0.2cm-0.8cm.
[0029] In some preferred embodiments, to prevent the system from tipping over, the limiting mechanism includes a limiter 4 and a limit spring 5. One end of the limit spring 5 is connected to the load platform 3, and the other end is connected to the limiter 4. The elastic coefficient of the limit spring 5 is 1000 kN / m. The limiter 4 is made of steel.
[0030] In some preferred embodiments, the rubber air spring 1 is connected to the additional air chamber 11 via a throttle tube 12.
[0031] The working principle of this invention is as follows: When an external load is applied to the system, the rectangular outer support 2 and the load platform 3 move relative to each other. At this time, points A and B in the connecting rod 6 are displaced relative to each other, thereby driving the hydraulic pipe container piston 8 to move. When the piston 8 moves inside the hydraulic pipe container cylinder, it drives the liquid inside the cylinder to flow through the spiral pipe 9. Since the pipe diameter is much smaller than the cylinder diameter, the fluid velocity inside the pipe is amplified relative to the piston velocity. The inertial coefficient of the device can be further amplified by increasing the piston area or decreasing the channel cross-sectional area.
[0032] System plan view (since the system vibration is less than millimeters, multiple links only need a certain height difference to avoid each other).
[0033] Links 6 are symmetrically distributed around the load platform 2, and there are height differences between them. There are a total of 4 links 6.
[0034] When the piston 8 moves, it pushes the liquid in the cylinder to flow. The liquid flows from the inlet and outlet 13 on one side to the inlet and outlet 13 on the other side along the spiral tube 9.
[0035] When an external load is applied to the system, the velocity of the rectangular outer support 2 is: The speed of load platform 3 is When the inertial container piston moves, the velocity of the inertial container piston is: but
[0036]
[0037] Assuming the hydraulic oil is incompressible during operation, then based on the fact that the inflow and outflow are equal, then...
[0038]
[0039] Where A1 represents the cross-sectional area of the hydraulic cylinder (or the working area of the piston), A2 represents the cross-sectional area of the spiral pipe, L represents the pipe length, v is the flow velocity of the hydraulic oil in the pipe, and ρ is the density of the hydraulic oil.
[0040] The energy of the liquid in the spiral tube 9 is
[0041] E g =ρA2Lv 2 / 2
[0042] This energy originates from the external energy brought by connecting rod 8, and therefore can be equivalent to the inertial mass m. b ,but
[0043]
[0044] Due to vibration isolation Compare It is large, therefore it can be approximated by calculation.
[0045]
[0046] (2) Equivalent stiffness of rubber air spring
[0047] Based on the dynamic equations of the main air chamber and the auxiliary air chamber, the reduced equivalent stiffness of the rubber air spring is obtained as follows:
[0048]
[0049] q is the flow rate in the throttling tube, ρ0 is the initial density, γ is the adiabatic coefficient, A is the initial effective area, P0 is the initial pressure in the gas chamber, and A e V is the effective area of the main air chamber. t The volume of the additional air chamber, V b The volume of the main air chamber.
[0050] (3) The dynamic equations of the system
[0051]
[0052] F(t) is the external load excitation force, m b Here, c is the inertial-compressive equivalent mass, c is the system damping, and k is the system stiffness.
[0053] Then its frequency is
[0054]
[0055] Therefore, by increasing the length L of the spiral pipe, increasing the cross-sectional area A1 of the hydraulic cylinder, decreasing the cross-sectional area A2 of the spiral pipe, and increasing the ratio of L2 to L1, ω can be reduced. At the same time, by adding an air chamber to reduce stiffness, ω is further reduced.
[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A low-frequency vibration isolation device under the combined action of air spring and inertial capacitance, characterized in that, The device includes a rubber air spring (1), an outer support (2), a load platform (3), a limiting mechanism, a connecting rod (6), a hydraulic inertia mechanism, and a mass block (10). The rubber air spring (1) is mounted on the outer support (2), and the load platform (3) is mounted on the top of the rubber air spring (1). The mass block (10) is set on the load platform (3). Limiting mechanisms are set on both sides of the mass block (10). One end of the connecting rod (6) is hinged to the outer support (2), and the middle part of the connecting rod (6) is hinged to the load platform (3). The other end of the connecting rod (6) is connected to the hydraulic inertia mechanism. The hydraulic inertia mechanism is fixedly connected to the outer support (2). The rubber air spring (1) is connected to an auxiliary air chamber (11).
2. The low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to claim 1, characterized in that, The outer support (2) is rectangular in shape.
3. The low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to claim 1, characterized in that, The hydraulic inertial container mechanism includes a hydraulic inertial container (7), a piston (8), and a spiral tube (9). The piston (8) is connected to the connecting rod (6) and is located inside the hydraulic inertial container (7). The spiral tube (9) is coiled around the outside of the hydraulic inertial container (7) and communicates with the inside of the hydraulic inertial container (7).
4. The low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to claim 3, characterized in that, The diameter of the spiral tube (9) is 0.2cm-0.8cm.
5. The low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to claim 1, characterized in that, The limiting mechanism includes a limiter (4) and a limiting spring (5). One end of the limiting spring (5) is connected to the load platform (3), and the other end is connected to the limiter (4).
6. The low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to claim 5, characterized in that, The elastic coefficient of the limiting spring (5) is 1000KN / m.
7. The low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to claim 6, characterized in that, The limiter (4) is made of steel.
8. The low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to claim 7, characterized in that, The rubber air spring (1) is connected to the auxiliary air chamber (11) via a throttle tube (12).
9. The low-frequency vibration isolation device under the combined action of air spring and inertial capacitance according to claim 1, characterized in that, The mass block (10) is rectangular.