Overhanging steel and concrete combined structure precision instrument and equipment air floating vibration isolation platform

Abstract

The utility model relates to the technical field of precision instrument equipment vibration isolation, provide a kind of overhanging steel and concrete combined structure precision instrument equipment air floatation vibration isolation platform.It contains the core counterweight formed by the steel structure framework filled with concrete and the permanent steel formwork of outer cladding;Symmetrically arranged in the two sides of core counterweight, through the overhanging structure connected with it by through type steel;Air spring vibration isolation system with external damper is set in the region of core counterweight;Precision reference device is set in the top of overhanging structure;And the maintenance passageway and auxiliary facilities of platform periphery.It is innovative in that: large mass high stiffness core counterweight significantly reduces the overall modal frequency of system, overhanging structure design realizes the full use of confined space, adjustable damping vibration isolation system ensures that platform disturbance recovers quickly after stable.Compared with prior art, effectively solve the problem that the vibration isolation efficiency of precision instrument equipment vibration isolation device near strong vibration source is insufficient, space adaptability is poor and anti-disturbance recovery ability is weak.

Description

Technical Field

[0001] This utility model relates to the technical field of vibration isolation for precision instruments and equipment, and in particular to a cantilevered steel and concrete composite structure air-floating vibration isolation platform for 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 is becoming increasingly prominent. 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 unique challenges far exceeding those of conventional production and experimental environments. To address these issues, active control vibration isolation systems or passive vibration isolation devices can generally be installed at the precision instruments and equipment. Specifically, the design of vibration isolation devices must be customized based on the weight and dimensions of the precision equipment and the reserved installation space. This is particularly important when space is limited near strong vibration sources such as vibration tables, where the device's dimensions must strictly meet the site's space constraints and requirements. For vibration isolation devices with customized dimensions exceeding 10m, active control requires multiple large actuators to ensure dynamic characteristics. This places extremely high demands on actuator manufacturing, and the coordinated control of multiple active actuators is very difficult, making active control challenging to achieve. Conventional passive vibration isolation devices (such as rubber pads and mechanical springs) have high natural frequencies, and their actual vibration isolation effect is only effective above the natural frequency. In the low-frequency range where strong vibration sources are abundant, the vibration isolation efficiency drops sharply, and may even amplify vibrations due to resonance, resulting in insufficient overall vibration isolation efficiency. Air-floating vibration isolation platforms, on the other hand, can arrange air springs according to the size and mass of the vibration isolation device. They have low natural frequencies and excellent vibration isolation performance for medium- and high-frequency vibrations, significantly isolating low-frequency interference from surrounding vibration sources, making them excellent passive vibration isolation devices. Furthermore, some precision instruments and equipment have specific performance requirements for vibration isolation devices: the maximum displacement and tilt angle of the vibration isolation device in any dimension at the equipment installation location must meet extremely small limits, and the vibration isolation device should recover stability within a short time after a strong disturbance to avoid affecting precision operation. Therefore, extremely stringent requirements are placed on the design of vibration isolation devices. Based on the above background, a cantilevered steel and concrete composite structure air-floating vibration isolation platform for precision instruments and equipment is proposed. Its shape is completely customized, and it features excellent vibration isolation performance, strong adaptability, and high durability. Utility Model Content

[0003] This invention aims to solve the vibration control problem of precision instruments and equipment near strong vibration sources (such as shaking tables and large impact equipment). Addressing the shortcomings of existing vibration isolation devices, such as insufficient isolation efficiency, poor spatial adaptability, and weak disturbance recovery capability, this invention provides a cantilevered steel-concrete composite structure air-floating vibration isolation platform for precision instruments and equipment. Through the design of this vibration isolation platform, while strictly meeting site space constraints and requirements, it significantly improves the platform's vibration isolation performance and meets the requirements for minimal displacement and tilt angle limits and rapid stable recovery under harsh vibration environments.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A cantilevered steel-concrete composite structure precision instrument air-bearing vibration isolation platform includes a core counterweight, a cantilever structure, an air spring vibration isolation system, a precision reference device, and maintenance access facilities. The core counterweight is a steel-concrete composite structure, consisting of an internally cast concrete steel frame and an externally encased permanent steel formwork, providing the vibration isolation platform with high mass and rigidity, ensuring a sufficiently low natural frequency for the vibration isolation system. The cantilever structure is a pure steel structure, symmetrically arranged on both short sides of the core counterweight. This design adapts to the limited space near the vibration table and concentrates the platform's mass in the central core counterweight, effectively reducing the vibration mode frequency at the cantilever end. The air spring vibration isolation system, constrained by space, is located on both long sides of the core counterweight, providing excellent vibration isolation for the platform. The precision reference device is located on the top surface of the cantilever structure, used to place precision equipment and instruments, providing a high-precision installation reference for the instruments. The maintenance access facilities are arranged around the vibration isolation platform, ensuring its operation throughout its entire life cycle.

[0006] Furthermore, the core counterweight adopts a steel and concrete composite structure. Its internal steel frame is filled with concrete, and except for the exposed top surface, all other surfaces are covered with permanent steel formwork to form a solid counterweight. This meets the counterweight requirements of precision equipment and ensures the vibration isolation platform possesses the necessary strength, rigidity, and overall stability. The steel frame is welded from high-strength steel, with a large-section steel main beam at the top and a small-section steel frame at the bottom (the lower part of the counterweight). The two parts are welded together as a whole, filled with concrete, and reinforced with crack-resistant steel mesh. The densely poured concrete fills the gaps inside the frame, forming a solid structure without cavities.

[0007] Furthermore, the cantilever structure is a pure steel structure, symmetrically arranged on both short sides of the core counterweight. A high-strength, large-section through-beam connects the central core counterweight to the cantilever structures on both sides, making the cantilevered portion and the core counterweight an integral whole. The cantilever structure is covered with permanent steel formwork to enhance the overall integrity of the vibration isolation platform structure. The length and width of the cantilever structure are customized according to the dimensions of the precision equipment, installation positioning, and the reserved space on both sides of the vibration isolation platform to ensure adaptability to space-constrained installation environments.

[0008] 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 for the air spring. Embedded parts are pre-installed in the concrete supports, providing a stable installation foundation for the air spring and viscous damper. The air springs are located on both long sides of the core counterweight block, with the number determined based on the overall mass and load of the structure.

[0009] Furthermore, the precision reference device is located at the top of the cantilever platform and includes a precision reference plate and fixing components. The precision reference plate is made of high-strength steel plate and is connected to the cantilever structure by bolts, providing a high-precision installation reference for precision instruments.

[0010] Furthermore, the maintenance access ancillary facilities include maintenance ports and maintenance channels. Maintenance ports are located on both sides of the core counterweight block, with dimensions designed according to maintenance requirements. Sealing strips are installed between the maintenance cover and the edge of the maintenance port to prevent dust from entering. Maintenance channels are arranged around the air springs for easy installation, adjustment, and maintenance.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The core counterweight of this invention features high mass and stiffness, significantly reducing the system's natural frequency. Combined with an ultra-low frequency air-bearing vibration isolation system, it effectively isolates mid-to-high frequency and low-frequency vibrations. Especially in the low-frequency range where strong vibration sources are abundant, its vibration isolation efficiency is significantly superior to passive vibration isolation devices such as rubber pads and mechanical springs. Furthermore, compared to active control systems, this platform has a simpler structure and is easier to implement, ensuring the stable operation of precision instruments in harsh vibration environments. The cantilever structure is custom-designed to address space constraints near strong vibration sources and the layout requirements of precision equipment, effectively solving the installation problem of vibration-sensitive precision equipment in space-constrained environments. The air spring vibration isolation system equipped with an external damper allows the platform to quickly recover stability after being disturbed by external forces. The precision reference device provides a high-precision installation reference surface for precision instruments and equipment, ensuring the positioning accuracy of the equipment and thus improving the accuracy of experiments or production. The inclusion of inspection ports and access channels facilitates the installation, debugging, and maintenance of the air spring vibration isolation system, ensuring reliable operation of the vibration isolation platform throughout its entire lifespan. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a plan view of the present invention;

[0015] Figure 3 This is a cross-sectional view (AA) of this utility model;

[0016] Figure 4 This is a BB cross-sectional view of this utility model;

[0017] Figure 5 This is a diagram of the installation embedded parts for this utility model;

[0018] Figure 6 This is the vibration isolation curve of this utility model.

[0019] In the diagram: 1. Core counterweight; 2. Cantilever structure; 3. Air spring; 4. Precision reference area; 5. Inspection cover plate; 6. Support pier; 7. Concrete foundation; 8. Longitudinal continuous steel beam; 9. Transverse steel beam; 10. Permanent steel formwork; 11. Transverse stiffening rib; 12. Counterweight lower swing steel; 13. Concrete; 14. Steel mesh; 15. Installation embedded parts; 16. Leveling bolt; 17. Anchor bar; 18. Reserved hole; 19. Air spring mounting hole; 20. Typical vibration isolation curve; 21. Natural frequency of vibration isolation platform; 22. Operating frequency of vibration isolation platform. Detailed Implementation

[0020] The following will be combined with the appendix Figures 1-6This 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.

[0021] like Figures 1-6 As shown, a cantilevered steel and concrete composite structure precision instrument air-floating vibration isolation platform consists of three levels from top to bottom: an upper vibration isolation platform, a middle air-floating vibration isolation system, and a lower platform installation system. The upper vibration isolation platform is composed of a core counterweight block 1 and cantilevered structures 2 symmetrically arranged on both sides of it, which are connected as a whole by a high-strength through-type steel main beam. Except for the exposed upper surface, the core counterweight block 1 is covered with permanent steel formwork 10, and its interior is a welded steel structure skeleton, which is divided into an upper main steel beam and a lower steel frame. The upper main steel beam is formed by welding longitudinal through steel beams 8 and transverse steel beams 9, and the lower steel frame is formed by welding the lower swing steel 12 of the counterweight block. The interior of the counterweight block is densely filled with concrete 13, and an inspection port is set in the middle of the long side of both sides of the counterweight block. The cantilevered structure 2 is covered with permanent steel formwork 10, and a precision reference area 4 is set on its top surface. The intermediate air-bearing vibration isolation system consists of air springs 3 with external viscous dampers, arranged symmetrically in a double "C" shape on both long sides of the core counterweight block 1. The lower platform installation system includes mounting embedded parts 15, concrete supports 6, and concrete foundations 7.

[0022] In this invention, based on the form and weight of the precision instruments and equipment, the reserved space of the platform, and the vibration generated by the external vibration source, the outer envelope plane dimensions of the vibration isolation foundation platform are customized to 17.7m × 7.5m. The central core counterweight block 1 is a rigid frame concrete structure with a plane dimension of 5.9 × 7.5m, with a 1.45m × 1.2m inspection port at the center of each side edge. The two symmetrical cantilever structures 2 are convex in shape, with a plane dimension of 3.85m × 3.6m + 2.05m × 5.8m. The total mass of the designed vibration isolation platform foundation is 288.38 tons, with a horizontal rigid mode of 0.632Hz and a vertical rigid mode of 0.801Hz.

[0023] In this utility model, the air springs are designed according to the shape, mass and reserved space of the vibration isolation platform. A total of 14 air springs are arranged on both sides of the core counterweight 1, with 7 on each side, arranged in a symmetrical double "C" shape.

[0024] In this invention, the typical vibration isolation curve 20 of the vibration isolation platform is shown in [reference 20]. Figure 6This is the vibration transfer function curve of ground vibration transmitted to the top surface of the vibration isolation platform. Here, 21 is the natural frequency of the vibration isolation platform, and 22 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 22 of the vibration isolation platform is less than the dominant frequency of ground vibration.

[0025] Preferably, the longitudinal through steel beam 8 is made of Q355B H-beams, the beam section of the core counterweight block 1 area is 880mm×550mm×25mm×30mm, the cantilever structure 2 area is a variable cross-section beam with a cross-section of 240~880mm×550mm×25mm×30mm, and the total length of the steel beam is 17.7m.

[0026] Preferably, the transverse steel beam 9 is made of Q355B H-beams with a cross-sectional dimension of 880mm×500mm×25mm×30mm and a length of 7.5m.

[0027] Preferably, the permanent steel formwork 10 is made of Q235B thick steel plate, wherein the thickness of the lower steel plate at the variable cross section of the cantilever area is 30mm, the thickness of the lower steel plate at the uniform cross section is 50mm, the thickness of the upper steel plate is 50mm, the thickness of the side wall steel plate is 18mm, and the thickness of the lower part of the core counterweight block and the side wall steel plate is 18mm.

[0028] Preferably, the transverse stiffening rib 11 is made of Q235B steel plate with a thickness of 20mm.

[0029] Preferably, the lower swing steel 12 of the counterweight is made of Q355B H-beam steel with a cross-sectional specification of 200mm×200mm×8mm×12mm.

[0030] Preferably, the concrete 13 is C35 grade concrete, which is densely poured into the core counterweight block 1.

[0031] Preferably, the steel mesh 14 is welded to the upper flange of the longitudinally penetrating steel beam 9 at the top of the core counterweight block 1, and uses single-layer bidirectional HRB400 steel bars with a diameter of 14mm and a spacing of 150mm to prevent cracking of the concrete upper surface of the core counterweight block 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 3 is a single-cavity air spring with a single load capacity of 20 to 25 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 mounting embedded part 15 is made of Q235B steel plate with a thickness of 30mm, and includes 3 leveling bolts 16, 15 anchor bars 17 with a diameter of 25mm and through-hole plug welding, 1 reserved hole 18 with a diameter of 400mm, and 4 air spring mounting holes 19.

[0035] Preferably, the precision reference area 4 is made of Q235B steel plate, which has mounting holes, leveling threaded holes and tapered positioning holes to ensure the horizontality of the precision equipment installation.

[0036] Preferably, the inspection cover 5 is made of Q235B steel plate with a thickness of 12mm.

[0037] 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; the general principles defined herein may be implemented in other embodiments without departing from the core spirit or scope of protection of the present invention. Therefore, the present invention is not to be limited to the embodiments shown in this specification, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cantilevered steel and concrete composite structure air-bearing vibration isolation platform for precision instruments and equipment, characterized in that, The system includes a core counterweight, a cantilever structure, an air spring vibration isolation system, a precision reference device, and maintenance access facilities. The core counterweight is a steel and concrete composite structure, consisting of a steel frame filled with concrete and an outer permanent steel formwork. The cantilever structure is a pure steel structure, symmetrically arranged on both short sides of the core counterweight and integrally connected to the core counterweight via longitudinal through-beams. The air spring vibration isolation system is arranged on both long sides of the core counterweight in a symmetrical double "C" shape. The precision reference device is located on the top surface of the cantilever structure. The maintenance access facilities are arranged around the vibration isolation platform.

2. The cantilevered steel and concrete composite structure precision instrument air-bearing vibration isolation platform according to claim 1, characterized in that, The core counterweight block adopts a steel and concrete composite structure. Its internal steel frame is filled with concrete, and except for the top surface which is exposed, the other surfaces are covered with permanent steel formwork to form a solid counterweight block. The steel frame is welded from high-strength steel, with a large-section steel main beam at the top and a steel frame made of small-section steel at the bottom. The two parts are welded together as a whole, and the interior is filled with concrete and equipped with crack-resistant steel mesh. The concrete is poured densely to fill the gaps inside the frame, forming a solid structure without cavities.

3. The cantilevered steel and concrete composite structure precision instrument and equipment air-floating vibration isolation platform according to claim 1, characterized in that, The cantilever structure is a pure steel structure, symmetrically arranged on both short sides of the core counterweight block; the central core counterweight block and the cantilever structures on both sides are connected by a high-strength, large-section through-type steel main beam. The outer surface of the cantilever structure is covered with permanent steel formwork to enhance the overall integrity of the vibration isolation platform structure; the length and width of the cantilever structure are customized according to the size of the precision equipment, installation positioning, and reserved space on both sides of the vibration isolation platform.

4. The cantilevered steel and concrete composite structure precision instrument air-bearing vibration isolation platform according to claim 1, characterized in that, The air spring vibration isolation system includes air springs, viscous dampers, air supply devices, embedded parts, and concrete supports. The air springs are single-cavity air springs, consisting of a metal shell, a piston mechanism, and a sealing diaphragm. The piston is sealed to the shell via the sealing diaphragm. The air springs utilize external viscous dampers to adjust the damping coefficient of the isolator. The air supply device uses an oil-free air source. The embedded parts are pre-embedded in the concrete supports. The air springs are located on both long sides of the core counterweight block, with the number determined based on the overall mass and load of the structure.

5. The cantilevered steel and concrete composite structure precision instrument and equipment air-floating vibration isolation platform according to claim 1, characterized in that, The precision reference device is located at the top of the cantilever platform and includes a precision reference plate and fixing components; the precision reference plate is made of high-strength steel plate and is connected to the cantilever structure by bolts.

6. The cantilevered steel and concrete composite structure precision instrument air-bearing vibration isolation platform according to claim 1, characterized in that, The maintenance access facilities include maintenance ports and maintenance channels; the maintenance ports are located on both sides of the core counterweight block, and their size is designed according to maintenance needs. Sealing strips are installed on the maintenance cover and the edge of the maintenance port to prevent dust from entering; the maintenance channels are arranged around the air spring to facilitate the installation, debugging and maintenance of the air spring.

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