A large-scale precision instrument and equipment air-floating vibration isolation platform with surrounding support

Abstract

The utility model discloses a kind of around support type ultra-low frequency large-scale precision instrument and equipment air floatation vibration isolation platform, including profile steel-concrete platform, permanent steel formwork, air spring vibration isolation system, profile steel-concrete platform is the composite structure platform of four edge overhanging that H-shaped steel rigid skeleton and filling concrete pouring are formed, permanent steel formwork is except platform upper surface, platform remaining surface is all covered with 18mm thick steel plate, air spring is evenly arranged along platform periphery, composition annular array, form unique around pneumatic vibration isolation platform.This patent improves the overall rigidity and installation adaptability of vibration isolation platform by outer permanent steel formwork profile steel-concrete platform, through the air spring of around arrangement, the problem that air spring is easily uneven stress under eccentric load is solved.The present application has the following advantages compared with prior art: excellent vibration isolation performance, high stability, strong adaptability, convenient construction.

Description

Technical Field

[0001] This utility model relates to the field of vibration isolation for high-precision instruments and equipment, specifically a surround-supported air-bearing vibration isolation platform for large-scale ultra-low frequency precision instruments and equipment. Background Technology

[0002] With the booming development of China's high-tech industries and the steady implementation of advanced scientific laboratory projects, the importance of environmental micro-vibrations in production and experimentation has become increasingly prominent, and it has become an issue that cannot be ignored. This is especially true when there are strong vibration sources (such as vibration tables and large impact equipment) near precision instruments and equipment, where vibration control becomes even more critical. Environmental vibrations near strong vibration sources are characterized by large amplitude, wide frequency range, and concentrated energy, posing a severe challenge to the normal operation of nearby precision instruments and equipment. Installing vibration isolation devices in such harsh vibration environments requires solving the unique challenges of micro-vibrations far exceeding those in conventional production and experimental environments. To address this problem, there are generally three approaches: active vibration isolation at the source, structural design along the path, and passive vibration isolation at the precision instruments. In practical engineering, these three vibration suppression schemes often need to be considered comprehensively. Among these, installing passive vibration isolation devices at the precision instruments and equipment is a common approach. Traditional passive vibration isolation (such as rubber pads and mechanical springs) is only effective at frequencies far above their natural frequencies, but in the low-frequency range where strong vibration sources are abundant, the isolation efficiency drops sharply, and may even amplify vibrations due to resonance, resulting in insufficient overall isolation efficiency. Air-bearing vibration isolation platforms exhibit excellent vibration isolation performance for medium- and high-frequency vibrations. Furthermore, their low natural frequency effectively isolates low-frequency interference from surrounding vibration sources, making them excellent passive vibration isolation devices. However, for precision instruments and equipment with uncertain or frequently changing positions, shifts in the center of gravity can lead to coupling between the various degrees of freedom in the isolation system, easily resulting in horizontal and rotational coupled motions, thus degrading vibration isolation performance. To address this issue, large-mass counterweights are often used to reduce changes in the system's center of gravity and ensure that the modal frequency of the flexible body is higher than the sensitive frequency of the precision equipment itself. For large-mass counterweights, more air springs are needed to distribute the load. Conventional two-sided air spring vibration isolation platforms are sensitive to changes in the center of gravity, and under eccentric loads, the air springs are prone to uneven stress. Therefore, a surround-supported ultra-low-frequency air-bearing vibration isolation platform for large precision instruments and equipment is proposed. Its shape is fully customized, and it features excellent vibration isolation performance, strong adaptability, and high durability. Utility Model Content

[0003] To address the shortcomings of existing passive vibration isolation devices, such as insufficient vibration isolation efficiency, poor spatial adaptability, and sensitivity to changes in center of gravity, this invention provides a ring-supported air-floating vibration isolation platform for large-scale precision instruments and equipment operating at ultra-low frequencies. This invention utilizes H-beams as a rigid frame, combined with concrete to form a "steel-concrete" composite structure platform, achieving an innovative integration of materials and structure. The platform's outer side employs an integrated permanent steel formwork, effectively improving the overall rigidity of the platform, significantly enhancing structural stability and vibration isolation performance. Furthermore, it effectively improves the adaptability and precise installation speed of the vibration isolation platform in complex environments such as those with limited space. Air springs are evenly arranged around the bottom perimeter of the platform, forming a ring array, creating a unique ring-supported pneumatic vibration isolation platform. This effectively solves the problem of uneven stress distribution on air springs under eccentric loads, providing a more stable support environment for precision equipment.

[0004] The technical solution of this utility model is implemented as follows:

[0005] A surround-supported air-bearing vibration isolation platform for large-scale precision instruments and equipment with ultra-low frequency vibrations includes a steel-concrete platform, a permanent steel formwork, and an air spring vibration isolation system. The steel-concrete platform is a composite structure platform with four cantilevered sides, composed of an H-shaped steel rigid frame and filled concrete. The steel-concrete platform can provide greater stiffness and mass, ensuring that the vibration isolation system has a low natural frequency. The permanent steel formwork consists of 18mm thick steel plates covering the entire surface of the platform except for the top surface, ensuring the construction efficiency and overall rigidity of the vibration isolation platform. The air spring vibration isolation system is evenly distributed around the platform, under the four cantilevered sides, providing excellent vibration isolation effect.

[0006] Furthermore, based on the appearance and location of the upper precision instruments, as well as the volume and height of the air springs, the planar dimensions and height of the steel-concrete platform are customized to adapt to space-constrained installation environments.

[0007] Furthermore, the H-shaped steel rigid frame is made of high-strength steel, including H-shaped steel columns and H-shaped steel beams, which are welded to the external permanent steel formwork to form an integral whole. The interior is filled with concrete and reinforced with crack-resistant steel mesh. When the concrete is poured, the gaps inside the frame are fully filled to form a solid structure without cavities.

[0008] Furthermore, the outer surface of the air-float vibration isolation platform is coated with epoxy resin.

[0009] Furthermore, the design of air springs is based on the shape and mass of the vibration isolation platform, and the number is determined according to the overall mass and load of the structure.

[0010] Furthermore, the air spring vibration isolation system includes an air spring, a viscous damper, an air supply device, embedded parts, and concrete supports. The air spring is a single-cavity air spring, consisting of a metal shell, a piston mechanism, and a sealing diaphragm. The piston is sealed to the shell via the sealing diaphragm, which possesses good elasticity and airtightness, ensuring the stable support performance of the air spring. To achieve good damping characteristics, the air spring employs an external viscous damper to adjust the damping coefficient of the isolator, adapting to vibration isolation requirements under different vibration environments. The supporting air supply device uses an oil-free air source to provide stable air pressure to the air spring.

[0011] Furthermore, the air spring is installed on the upper part of the concrete support via embedded parts.

[0012] Furthermore, the dimensions and height of the concrete support are determined based on the dimensions of the air spring, and are obtained by pre-reserving reinforcing bars during the construction of the concrete foundation before pouring.

[0013] Furthermore, the embedded part is a steel plate with leveling bolts and anchor bars. After the concrete support is poured, the flatness of the embedded part is adjusted by the leveling bolts.

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

[0015] Using H-beams as the stiffening frame, combined with concrete to form a "steel-concrete" composite structure platform, provides greater stiffness and mass, ensuring a lower natural frequency for the vibration isolation system. Simultaneously, the platform's outer surface is covered with permanent steel formwork, facilitating on-site construction and installation, and guaranteeing construction efficiency and overall rigidity. Appropriate design of the air springs allows for the creation of a vibration isolation platform with the target frequency. By evenly arranging the air springs around the platform's perimeter in a ring array, a unique surround-type pneumatic vibration isolation platform is formed, effectively solving the problem of uneven stress distribution on air springs under eccentric loads, providing a more stable support environment for precision equipment. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0017] Figure 2 This is a plan view of the present invention;

[0018] Figures 3-4 This is a longitudinal sectional view of the present invention;

[0019] Figure 5 This is a drawing of the embedded parts for installation in this utility model;

[0020] Figure 6 This is the vibration isolation curve diagram of this utility model;

[0021] In the diagram: 1. Steel-concrete platform; 2. Air spring; 3. Concrete support; 4. Concrete foundation; 5. H-beam; 6. H-column; 7. Permanent steel formwork; 8. Crack-resistant steel mesh; 9. Filling concrete; 10. Embedded parts; 11. Leveling bolts; 12. Anchor bars; 13. Grouting holes; 14. Air spring mounting holes; 15. Typical vibration isolation curve; 16. Natural frequency of the vibration isolation platform; 17. Operating frequency of the vibration isolation platform. Detailed Implementation

[0022] The following will be combined with the appendix Figures 1-6 This utility model will be described in detail, and the technical solutions in the embodiments of this utility model will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0023] like Figures 1-6 As shown, a surround-supported air-floating vibration isolation platform for large-scale precision instruments and equipment with ultra-low frequency includes a steel-concrete platform 1, a permanent steel formwork 7, and an air spring 2. The steel-concrete platform 1 is a composite structure platform with four cantilevered sides, composed of an H-shaped steel rigid frame and filled concrete 9. The H-shaped steel rigid frame is formed by welding H-shaped steel beams 5 and H-shaped steel columns 6. The permanent steel formwork 7 is welded and wrapped around the surfaces of the H-shaped steel rigid frame except for the upper surface of the platform, and the interior is filled with concrete 9. The air spring 2 with damper is a passive vibration isolation unit. The embedded parts 10, concrete supports 3, and concrete foundations 4 constitute the lower platform installation system.

[0024] In this invention, the vibration isolation foundation platform is custom-designed based on the appearance and layout of the upper precision instruments, the reserved space of the platform, and the vibrations generated by the external vibration source. The outer envelope plane dimensions are 10m × 10m, and the height is 2.6m. The upper plane dimensions of the platform are 10m × 10m, and the height is 1m. The lower plane dimensions are 5.3m × 7.8m, and the height is 1.6m. The upper and lower platforms are integrally cast to form a four-sided cantilevered composite structure platform. The total mass of the designed vibration isolation platform foundation is 474.14 tons, with a horizontal rigid mode of 0.795Hz and a vertical rigid mode of 1.0081Hz.

[0025] In this invention, the design of the air springs is determined by calculation based on the shape and mass of the vibration isolation platform. In this example, 24 air springs are evenly arranged below the four cantilevered sides of the steel-concrete platform 1 to form a ring array.

[0026] In this invention, the typical vibration isolation curve 15 of the vibration isolation platform is shown in [reference 15]. Figure 6This is the vibration transfer function curve of ground vibration transmitted to the top surface of the vibration isolation platform. Here, 16 is the natural frequency of the vibration isolation platform, and 17 is the frequency at which the platform begins operation, which is 1.414 times the natural frequency. In practical vibration isolation platform design, it is necessary to ensure that the operating frequency 17 of the vibration isolation platform is less than the dominant frequency of ground vibration.

[0027] Preferably, the H-beam 5 is made of Q355B H-beams with a cross-sectional dimension of 200mm×200mm×8mm×12mm.

[0028] Preferably, the H-shaped steel column 6 is made of Q355B H-shaped steel, and the beam cross-section is 200mm×200mm×8mm×12mm.

[0029] Preferably, the permanent steel formwork 7 is made of Q355B thick steel plate with a thickness of 18mm.

[0030] Preferably, the filling concrete 9 is C35 grade concrete, which is densely poured into the steel-concrete platform 1.

[0031] Preferably, the steel anti-crack mesh 8 is distributed on the top of the steel-concrete platform 1 and welded to the upper flange of the H-beam 5. It uses single-layer bidirectional HRB400 steel bars with a diameter of 14mm and a spacing of 150mm, in order to prevent cracking on the upper surface of the steel-concrete platform 1.

[0032] Preferably, all steel surfaces should be sandblasted or shot-blasted to remove rust before painting; manual rust removal is prohibited. After rust removal, apply two coats of epoxy zinc-rich primer with a dry film thickness ≥70μm; then apply one coat of epoxy micaceous iron oxide intermediate paint with a dry film thickness ≥70μm; finally, apply three coats of epoxy topcoat with a dry film thickness ≥100μm. Damaged areas should be locally touched up during installation.

[0033] Preferably, the air spring 2 is a single-cavity air spring with a single load capacity of about 20 tons, a vertical natural frequency of 0.6 to 0.8 Hz, and a horizontal natural frequency of 0.4 to 0.7 Hz, ensuring that the vibration isolation platform has an ultra-low frequency natural frequency.

[0034] Preferably, the embedded part 10 is made of Q235B steel plate with a thickness of 30mm, and includes 3 leveling bolts 11, 15 anchor bars 12 with a diameter of 25mm and through-hole plug welding, 1 grouting hole 13 with a diameter of 400mm, and 4 air spring mounting holes 14.

[0035] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A surround-supported ultra-low frequency large precision instrument air-bearing vibration isolation platform, characterized in that, The system includes a steel-concrete platform (1) customized according to the appearance, layout and vibration of the upper precision instrument and the external vibration source, a permanent steel formwork (7) to improve the overall rigidity of the platform, and air springs (2) evenly arranged around the bottom of the platform to form a ring array; the air springs (2) are installed on the upper part of the concrete support (3) through embedded parts (10), the size and height of the concrete support (3) are determined according to the size of the air springs (2), and are obtained by pre-reserving steel bars during the construction of the concrete foundation (4) and then pouring.

2. The air-bearing vibration isolation platform for ultra-low frequency large-scale precision instruments and equipment with surrounding support as described in claim 1, characterized in that, The steel-concrete platform (1) is composed of an H-shaped steel rigid frame and filled concrete (9).

3. The air-bearing vibration isolation platform for ultra-low frequency large-scale precision instruments and equipment with surrounding support as described in claim 2, characterized in that, The H-shaped steel stiffening frame is formed by welding H-shaped steel beams (5) and H-shaped steel columns (6).

4. The air-bearing vibration isolation platform for ultra-low frequency large-scale precision instruments and equipment with surrounding support as described in claim 1, characterized in that, The permanent steel formwork (7) is welded to the surfaces of the H-beam rigid frame, excluding the upper surface of the platform.

5. The air-bearing vibration isolation platform for ultra-low frequency large-scale precision instruments and equipment with surrounding support as described in claim 1, characterized in that, A steel anti-crack mesh (8) is provided on the top of the steel-concrete platform (1) and welded and fixed to the upper flange of the H-beam (5).

6. The air-bearing vibration isolation platform for ultra-low frequency large-scale precision instruments and equipment with surrounding support as described in claim 2, characterized in that, The filling concrete (9) is made of C35 strength concrete and is densely poured into the steel-concrete platform (1).

7. The air-bearing vibration isolation platform for ultra-low frequency large-scale precision instruments and equipment with surrounding support as described in claim 1, characterized in that, The vibration isolation platform starts operating at a frequency 1.414 times its natural frequency, and the operating frequency of the vibration isolation platform is less than the main frequency of ground vibration.

8. The air-bearing vibration isolation platform for ultra-low frequency large-scale precision instruments and equipment with surrounding support as described in claim 1, characterized in that, The damping coefficient of the air spring (2) is adjusted by using an external viscous damper.

9. The air-bearing vibration isolation platform for ultra-low frequency large-scale precision instruments and equipment with surrounding support as described in claim 1, characterized in that, The embedded part (10) is a steel plate with leveling bolts (11) and anchor bars (12). After the concrete support pier (3) is poured, the flatness of the embedded part (10) is adjusted by leveling bolts (11).

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