Noise reduction type double-cavity air spring structure

Abstract

The noise reduction type double-cavity air spring structure comprises an upper top seat and a shock absorber, the upper top seat comprises an upper shell and a lower shell, the upper shell is arranged at the upper end of the lower shell, and a reinforcing structure is arranged on the upper shell; a piston is arranged outside the shock absorber, a bag skin is connected between the bottom end of the lower shell and the top end of the piston, a protective barrel is arranged outside the bag skin, a dust cover is arranged between the bottom end of the protective barrel and a piston cushion block, and the piston cushion block is arranged among the bottom of the piston, the shock absorber and the dust cover.

Description

Technical Field

[0001] This invention belongs to the field of air spring technology. Specifically, this invention relates to a noise-reducing dual-cavity air spring structure. Background Technology

[0002] Currently, air springs are widely used in vehicle shock absorption. The advantage of dual-chamber air springs over single-chamber air springs is that their stiffness is adjustable. However, dual-chamber air springs have a relatively complex structure due to the need to arrange stiffness valves. Depending on the overall vehicle layout, air springs are divided into integrated or separate structures of shock absorbers and air springs.

[0003] When the shock absorber and air spring are integrated into a single structure, the upper end of the air spring is connected to the vehicle body via bolts, and the lower end of the shock absorber is connected to the lower control arm via a bushing assembly or ball joint. Currently, most shock absorbers are connected to the lower control arm via a bushing assembly. Therefore, during vehicle operation, insufficient friction at the piston-shock absorber mating point causes torsion between the piston and shock absorber, generating noise. Furthermore, when the shock absorber and air spring are integrated, the stiffness valve is generally located on the upper mounting seat. Due to the complex structure of the upper mounting seat, it is usually made of plastic. However, the upper mounting seat needs to contact the vehicle body and bear a large load, resulting in insufficient strength. It also requires threaded holes to match the bolts. Because the bolts need to be disassembled and tightened multiple times with a large torque, the threads frequently strip.

[0004] Utility model patent CN208982568U, published on June 14, 2019, discloses a nitrogen spring with noise reduction and anti-seize function. This nitrogen spring includes a cylinder, a piston rod, and a bushing assembly. The bushing assembly is installed inside the cylinder. A noise reduction groove is formed on the upper end face of the piston rod. The lower part of the piston rod passes through the bushing assembly and extends into the cylinder. A sealing element is provided between the piston rod and the bushing assembly. The lower end of the piston rod extends circumferentially to form a limiting step, and a groove is provided at the center of the lower end of the piston rod. This nitrogen spring cannot solve the problem of thread stripping. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a noise-reducing dual-cavity air spring structure that offers reliable connection and reduced noise.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The noise-reducing dual-chamber air spring structure includes an upper base and a shock absorber. The upper base includes an upper shell and a lower shell. The upper shell is located on top of the lower shell and has a reinforcing structure. A piston is provided outside the shock absorber. A bladder is connected between the bottom end of the lower shell and the top end of the piston. A protective sleeve is provided outside the bladder. A dust cover is provided between the bottom end of the protective sleeve and the piston pad. A piston pad is provided between the bottom of the piston, the shock absorber, and the dust cover.

[0008] The reinforcing structure includes a mounting plate, which is embedded in the upper end of the upper housing. The upper end of the mounting plate is on the same plane as the upper end of the upper housing. The end of the mounting plate is provided with a mounting seat, and a threaded sleeve is embedded in the mounting seat. The bottom of the threaded sleeve is provided with a waist-shaped platform, which extends from the bottom of the mounting plate. The end of the mounting plate is provided with a limiting boss, one side of which is parallel to the side of the waist-shaped platform. There is a gap between the limiting boss and the waist-shaped platform.

[0009] The vibration damper includes an outer cylinder, a piston pad is fitted onto the outer cylinder, and a piston sealing ring is provided between the outer cylinder, the bottom end of the piston, and the end of the piston pad. A vibration damper tray is fixedly connected to the outer cylinder, and the vibration damper tray abuts against the inner side of the piston pad. The piston pad is provided with a mounting boss that extends from the vibration damper tray. Second ribs are evenly distributed on the outside of the mounting boss, and the second ribs are interference-fitted with the vibration damper tray.

[0010] The outer side of the threaded sleeve is uniformly distributed with first raised ribs, which are interference fit with the mounting plate; the inner side of the piston pad is uniformly distributed with first reinforcing ribs, and the outer side of the piston pad is uniformly distributed with second reinforcing ribs; the piston pad is clearance fit with the outer cylinder of the shock absorber, and the second reinforcing rib is clearance fit with the inner side of the piston.

[0011] The piston pad has a stepped structure. The upper end of the piston pad is provided with an installation step. The installation step is located between the piston and the outer cylinder of the shock absorber. The top of the installation step contacts the piston sealing ring. The first reinforcing rib and the second reinforcing rib are respectively provided on the inner and outer sides of the installation step. The bottom end of the piston pad is provided with a snap-fit ​​step. The bottom end of the dust cover snaps into the snap-fit ​​step.

[0012] The mounting plate has a top cover in the middle, the upper end of which extends out of the mounting plate. A retaining spring is provided between the inner side of the mounting plate and the end of the top cover, and a sealing ring is provided at the end of the top cover. A bushing assembly is provided between the top cover and the upper housing. A piston rod is provided inside the outer cylinder of the shock absorber. The piston rod extends out of the outer cylinder of the shock absorber and into the bushing assembly. A nut is connected between the bushing assembly and the top of the piston rod. A buffer block is fitted on the piston rod. The buffer block is located inside the lower housing, and the top of the buffer block is engaged with the upper housing.

[0013] The lower housing has a first toothed section at its bottom end and a second toothed section at its top end. Both the first and second toothed sections have a serrated cross-section. The two ends of the bladder skin are in contact with the first and second toothed sections, respectively. The two ends of the bladder skin are fitted with a first and a second clamping ring, respectively, which press the two ends of the bladder skin tightly. The bottom end of the lower housing has a stepped structure, and a steel ring is embedded in the inner side of the bottom end of the lower housing. The upper end of the protective sleeve is fitted over the outside of the bladder skin, and the bottom end of the protective sleeve is engaged with the top end of the dust cover.

[0014] The upper shell is provided with an upper shell reinforcing rib on its exterior, and the lower shell is provided with a lower shell reinforcing rib on its exterior. The upper shell reinforcing rib has a boss at its end, and the bottom of the boss is higher than the top of the lower shell reinforcing rib.

[0015] The upper housing is externally connected to an air transfer channel, which is connected to a pressure holding valve; a stiffness valve is provided inside the upper top seat, and a pad is provided at one end of the stiffness valve inside the upper top seat. A retaining ring is provided on one side of the pad, and a first sealing ring is provided between one end of the stiffness valve and the upper top seat, and a second sealing ring is provided between the other end of the stiffness valve and the upper top seat.

[0016] The piston stop is made of a material with a low coefficient of friction.

[0017] The technical advantages of this invention are as follows: The noise-reducing dual-chamber air spring structure of this invention incorporates an embedded mounting plate within the upper housing, enhancing the structural strength of the upper top seat. A threaded sleeve is also provided within the mounting plate; this rationally designed embedded threaded sleeve structure satisfies bolt installation while preventing rotation, thus improving the threaded connection strength and reliability between the upper top seat and the vehicle body. This ensures that the threads do not strip or the embedded threaded sleeve does not come loose after repeated disassembly and reassembly of the air spring. Furthermore, the piston pad changes the connection method between the piston and the shock absorber, avoiding direct contact between them and preventing direct metal-to-metal contact, thereby solving the problem of torsional noise in the air spring and achieving noise reduction. This noise-reducing dual-chamber air spring structure optimizes and improves the installation, assembly, and fit between components, offering advantages such as convenient installation, compact structure, reliable structural strength, and ease of processing and molding. Attached Figure Description

[0018] This manual includes the following figures, which illustrate the following:

[0019] Figure 1 This is a cross-sectional view of the noise-reducing dual-cavity air spring structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the upper support of the present invention;

[0021] Figure 3This is a cross-sectional structural diagram of the stiffness valve installation of the present invention;

[0022] Figure 4 This is a schematic diagram of the mounting plate of the present invention;

[0023] Figure 5 This is a schematic diagram of the vibration damper of the present invention;

[0024] Figure 6-1 and Figure 6-2 This is a schematic diagram of the piston pad block of the present invention;

[0025] Figure 7 This is a schematic diagram of the structure of the screw sleeve of the present invention;

[0026] Figure 8 This is a cross-sectional schematic diagram of the connection position between the upper and lower housings of the present invention. Detailed Implementation

[0027] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.

[0028] like Figure 1 As shown, the noise-reducing dual-chamber air spring structure includes an upper top seat and a shock absorber. The upper top seat includes an upper shell and a lower shell. The upper shell is located on the upper end of the lower shell and has a reinforcing structure. A piston is provided outside the shock absorber. A bladder is connected between the bottom end of the lower shell and the top end of the piston. A protective sleeve is provided outside the bladder. A dust cover is provided between the bottom end of the protective sleeve and the piston pad. A piston pad is provided between the bottom of the piston, the shock absorber and the dust cover. The upper housing is embedded in the lower housing to form the upper top seat. The embedded metal parts and the threaded sleeve constitute the reinforcing structure of the upper housing. By designing the limiting boss and the waist-shaped platform of the threaded sleeve, the threaded sleeve achieves the anti-rotation effect of the bolt, improves the thread strength, and avoids the situation of thread stripping and threaded sleeve coming out. A piston pad is designed at the connection between the piston and the shock absorber. The piston pad is made of plastic, which improves the connection method between the piston and the shock absorber. The original relative torsion between metals is changed to relative torsion between metal and plastic, which solves the torsion problem of the air spring and achieves the purpose of reducing noise. The bladder can be expanded and contracted to adapt to the movement of the piston. The protective sleeve is used to maintain part of the shape of the bladder and protect it.

[0029] like Figure 1 and 4As shown, the reinforcing structure includes a mounting plate embedded in the upper end of the upper housing. The upper end of the mounting plate is on the same plane as the upper end of the upper housing. A mounting seat is provided at the end of the mounting plate, and a threaded sleeve is embedded within the mounting seat. A waist-shaped platform is provided at the bottom of the threaded sleeve, extending from the bottom of the mounting plate. A limiting boss is provided at the end of the mounting plate, with one side of the limiting boss parallel to the side of the waist-shaped platform, and a gap between the limiting boss and the waist-shaped platform. The mounting plate is an embedded metal part of the upper housing, made of aluminum. After being embedded, the mounting plate is on the same plane as the upper end of the upper housing, increasing the strength of the upper top seat without increasing the volume of the air spring, and ensuring a firm and compact connection. The embedded threaded sleeve is made of high-strength steel, improving the connection strength of the bolts. The limiting boss extends from the end of the mounting plate, with its flat end parallel to and clearance-fitted with the waist-shaped platform of the embedded threaded sleeve. After injection molding, the plastic fills the gap, preventing the embedded threaded sleeve from rotating and avoiding thread stripping or the embedded threaded sleeve from coming out. Because the limiting boss is set parallel to the side of the waist-shaped platform and the gap width is consistent, the uniformity of plastic filling is ensured, thereby ensuring the reliable strength of the connection between the limiting boss and the waist-shaped platform.

[0030] like Figure 6-1 and Figure 6-2 As shown, the shock absorber includes an outer cylinder, a piston pad fitted onto the outer cylinder, and a piston sealing ring between the outer cylinder, the bottom of the piston, and the end of the piston pad. A shock absorber tray is fixedly connected to the outer cylinder, and the tray abuts against the inner side of the piston pad. The piston pad has a mounting boss extending from the tray, and second ribs are evenly distributed around the outside of the boss, with an interference fit between the second ribs and the tray. The piston pad design avoids direct contact between the piston and the shock absorber, thus preventing noise caused by torsion. The lower end face of the piston pad abuts against the tray, which has grooves or through holes. The second ribs are interference-fitted with these grooves or through holes, connecting the piston pad to the shock absorber. The piston is pressed against the piston pad by high-pressure gas from an air spring.

[0031] like Figure 7As shown, the outer side of the threaded sleeve has a first raised rib evenly distributed, and the first raised rib is interference-fitted with the mounting plate; the inner side of the piston pad has a first reinforcing rib evenly distributed, and the outer side of the piston pad has a second reinforcing rib evenly distributed. The piston pad is clearance-fitted with the outer cylinder of the shock absorber, and the second reinforcing rib is clearance-fitted with the inner side of the piston. The first raised rib improves the connection strength between the threaded sleeve and the mounting plate, further improving the anti-torsion effect of the threaded sleeve; the inner wall of the piston pad is clearance-fitted with the outer cylinder of the shock absorber, ensuring that the inner wall of the piston pad will not scratch the outer cylinder of the shock absorber during assembly; the first reinforcing rib is interference-fitted with the outer wall of the shock absorber tray, improving the bonding strength and installation stability between the piston pad and the shock absorber tray. Considering the process forming and assembly of the shock absorber tray and the piston pad, a transition fit or clearance fit can be used. At the same time, the first reinforcing rib makes the end face of the piston pad in contact with the shock absorber tray form multiple ventilation grooves. When the air spring assembly is tested for air tightness, if there is air leakage at the piston seal ring, it can be detected in time. The second reinforcing rib is fitted with the piston with a clearance, which reduces assembly difficulty and minimizes damage to the piston during assembly.

[0032] like Figure 6-1 and Figure 6-2 As shown, the piston pad has a stepped structure. The upper end of the piston pad has an installation step located between the piston and the outer cylinder of the shock absorber. The top of the installation step contacts the piston sealing ring. The first and second reinforcing ribs are located on the inner and outer sides of the installation step, respectively. The bottom end of the piston pad has a snap-fit ​​step, and the bottom end of the dust cover snaps into the snap-fit ​​step. Designing the piston pad as a stepped structure provides a connection point for the piston, the outer cylinder of the shock absorber, and the dust cover. Its structural design is reasonable, and the piston pad is in a stable installation position, achieving the effects of preventing torsion and reducing noise.

[0033] like Figure 1 As shown, a top cover is provided in the middle of the mounting plate, and the upper end of the top cover extends out of the mounting plate. A retaining spring is provided between the inner side of the mounting plate and the end of the top cover, and a sealing ring is provided at the end of the top cover. A bushing assembly is provided between the top cover and the upper housing. A piston rod is provided inside the outer cylinder of the shock absorber. The upper end of the piston rod extends out of the outer cylinder of the shock absorber and into the bushing assembly. A nut is connected to the top of the bushing assembly and the piston rod. A buffer block is fitted on the piston rod. The buffer block is located inside the lower housing, and the top of the buffer block is engaged with the upper housing. The bushing assembly is installed in the upper top seat, the buffer block is snapped and fixed to the upper top seat, the top cover is press-fitted onto the bushing assembly, and the bushing assembly and top cover are pressed tightly onto the upper top seat by a snap ring. The inner skeleton of the bushing assembly is connected to the piston rod of the shock absorber by a nut. The top cover is sealed to the upper top seat by a sealing ring. The sealing surface of the upper top seat is the inner wall surface of the upper housing. After the mounting plate and the upper housing are injection molded, due to the different shrinkage rates of the materials, there is a gap between the upper housing and the mounting plate. Therefore, the sealing ring is set to achieve the sealing of the inner wall surface of the upper housing.

[0034] like Figure 1 As shown, the lower housing has a first toothed section at its bottom and a second toothed section at the top of the piston. Both the first and second toothed sections have a serrated cross-section. The two ends of the bladder skin contact the first and second toothed sections respectively. A first and second clamping ring are respectively fitted onto the two ends of the bladder skin, pressing the two ends of the bladder skin tightly. The bottom of the lower housing has a stepped structure, and a steel ring is embedded on the inner side of the bottom of the lower housing. The upper end of the protective sleeve is fitted over the outside of the bladder skin, fitting snugly against the bladder skin. The bottom end of the protective sleeve is engaged with the top of the dust cover. One end of the bladder skin and the toothed section of the lower housing are connected and sealed by a clamping ring. The other end of the bladder skin and the toothed section of the piston are sealed and fixed by a clamping ring. The toothed section increases the contact area between the bladder skin, the lower housing, and the piston, increases the friction after compression, and improves the sealing performance and installation stability of the bladder skin. The above structure fixes the bladder skin, support ring, and protective sleeve together. The air piston consists of a support ring, bladder skin, and protective sleeve from the inside out. A support ring is also provided inside the casing. The casing, casing, and support ring are fixed together by clamping. The steel ring increases the strength of the bottom end of the lower shell, maintains the shape of the lower shell, prevents deformation due to excessive pressure, and further improves the sealing performance. The dust cover has a corrugated cross-section and a certain degree of flexibility to adapt to the movement of the piston and aluminum casing. One end of the dust cover is fixed to the casing by a clamp, and the other end is fixed to the piston pad by a snap-fit. The snap-fit ​​method reduces installation difficulty and improves production efficiency. A vent is provided at the snap-fit ​​end of the dust cover.

[0035] like Figure 8 As shown, the upper shell is provided with an upper shell reinforcing rib on the outside, and the lower shell is provided with a lower shell reinforcing rib on the outside. The upper shell reinforcing rib has a boss at its end, and the bottom of the boss is higher than the top of the lower shell reinforcing rib. The upper and lower shells are made of plastic and require hot gas welding. Hot gas welding involves heating the plastic to the required melting temperature, making it molten and viscous, before applying pressure to join them. Generally, a 1mm molten surface is left on each of the welding surfaces of the upper and lower shells. Since the molten plastic needs to withstand pressure, a reinforcing rib is installed on the outer wall of the upper and lower shells, 2-4mm away from the welding surface. The height and width of the reinforcing rib are both greater than or equal to 2mm to prevent deformation of the sidewalls due to pressure after melting. After welding, plastic overflows at the weld seam, affecting the aesthetics of the area between the two reinforcing ribs. Therefore, a downward-facing boss is added to the upper shell's reinforcing rib. After welding, the lower surface of the boss extends beyond the upper surface of the lower shell's reinforcing rib to cover the overflowing plastic, creating a seal at the connection and achieving a better aesthetic effect.

[0036] like Figure 2 and Figure 3As shown, the upper housing is externally connected to an air transfer channel, which in turn connects to a pressure-holding valve. A stiffness valve is housed within the upper top seat, with a pad at one end of the stiffness valve and a retaining ring on one side. A first sealing ring is located between one end of the stiffness valve and the upper top seat, and a second sealing ring is located between the other end of the stiffness valve and the upper top seat. The stiffness valve is fixed to the end face of the upper top seat via the pad and retaining ring. A certain axial clearance should be reserved for the stiffness valve to compensate for dimensional tolerances caused by the injection molding of the upper top seat. The stiffness valve achieves a seal through the first and second sealing rings, preventing air leakage between the stiffness valve and the upper top seat. A groove is provided on the side of the lower housing where the stiffness valve is installed. The lower end of the groove is positioned in the retaining spring groove of the lower housing of the upper top seat, facilitating the disassembly of the stiffness valve. The space between the bladder, upper top seat, piston, and shock absorber forms a first chamber, and the space between the upper top seat and the stiffness valve forms a second chamber. The first and second chambers are connected or disconnected by opening and closing the stiffness valve. Due to the layout of the vehicle space and gas pipelines, the pressure holding valve assembly cannot be directly sealed and fixed to the upper top seat. Therefore, an adapter air passage is added and sealed and fixed to the upper top seat. The adapter air passage is fixed to the upper top seat by bolts and sealed to the upper top seat by a sealing ring. The pressure holding valve assembly is connected to the adapter air passage by threads. The upper top seat has an air passage that communicates with the first chamber. The air passage is connected to the adapter air passage, the pressure holding valve, and the vehicle gas pipelines.

[0037] The piston stop is made of a low-friction coefficient material. The piston pad is made of a high-strength, low-friction coefficient material, and a layer of low-friction coefficient material can also be added to the piston pad on the surface in contact with the piston, which reduces the friction between the piston and the piston stop.

[0038] This dual-chamber air spring structure includes an upper top seat assembly, a piston, a shock absorber, a piston seal ring, and a piston pad. The piston, piston seal ring, and piston pad are all fitted onto the shock absorber. The assembly sequence is as follows: first, the piston pad is fitted onto the shock absorber; then, the piston seal ring is fitted onto the shock absorber and abuts against the upper end face of the piston pad; finally, the piston is fitted onto the shock absorber and abuts against the piston pad. The shock absorber also has an external connecting plate with connecting holes to provide installation positions for the shock absorber.

[0039] This noise-reducing dual-chamber air spring structure features an embedded mounting plate within the upper housing, enhancing the structural strength of the upper top mount. A threaded sleeve is integrated into the mounting plate; its rational design ensures both bolt installation and anti-rotation, improving the strength and reliability of the threaded connection between the upper top mount and the vehicle body. This prevents thread stripping and sleeve dislodgement even after repeated disassembly and reassembly of the air spring. Furthermore, the inclusion of a piston pad alters the piston-damper connection, preventing direct contact between the piston and damper, and avoiding direct metal-to-metal contact. This resolves the torsional noise issue of the air spring, thus reducing noise. This noise-reducing dual-chamber air spring structure optimizes the installation, assembly, and inter-component fit of its parts, offering advantages such as convenient installation, compact structure, reliable structural strength, and ease of fabrication.

[0040] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A noise-reducing dual-cavity air spring structure, characterized in that: The device includes an upper base and a shock absorber. The upper base includes an upper housing and a lower housing. The upper housing is located on top of the lower housing and has a reinforcing structure. The shock absorber has a piston outside. A bladder is connected between the bottom of the lower housing and the top of the piston. A protective sleeve is provided outside the bladder. A dust cover is provided between the bottom of the protective sleeve and the piston pad. A piston pad is provided between the bottom of the piston, the shock absorber, and the dust cover.

2. The noise-reducing dual-cavity air spring structure according to claim 1, characterized in that: The reinforcing structure includes a mounting plate, which is embedded in the upper end of the upper housing. The upper end of the mounting plate is on the same plane as the upper end of the upper housing. The end of the mounting plate is provided with a mounting seat, and a threaded sleeve is embedded in the mounting seat. The bottom of the threaded sleeve is provided with a waist-shaped platform, which extends from the bottom of the mounting plate. The end of the mounting plate is provided with a limiting boss, one side of which is parallel to the side of the waist-shaped platform. There is a gap between the limiting boss and the waist-shaped platform.

3. The noise-reducing dual-cavity air spring structure according to claim 2, characterized in that: The vibration damper includes an outer cylinder, a piston pad is fitted onto the outer cylinder, and a piston sealing ring is provided between the outer cylinder, the bottom end of the piston, and the end of the piston pad. A vibration damper tray is fixedly connected to the outer cylinder, and the vibration damper tray abuts against the inner side of the piston pad. The piston pad is provided with a mounting boss that extends from the vibration damper tray. Second ribs are evenly distributed on the outside of the mounting boss, and the second ribs are interference-fitted with the vibration damper tray.

4. The noise-reducing dual-cavity air spring structure according to claim 3, characterized in that: The outer side of the threaded sleeve is uniformly distributed with first raised ribs, which are interference fit with the mounting plate; the inner side of the piston pad is uniformly distributed with first reinforcing ribs, and the outer side of the piston pad is uniformly distributed with second reinforcing ribs; the piston pad is clearance fit with the outer cylinder of the shock absorber, and the second reinforcing rib is clearance fit with the inner side of the piston.

5. The noise-reducing dual-cavity air spring structure according to claim 4, characterized in that: The piston pad has a stepped structure. The upper end of the piston pad is provided with an installation step. The installation step is located between the piston and the outer cylinder of the shock absorber. The top of the installation step contacts the piston sealing ring. The first reinforcing rib and the second reinforcing rib are respectively provided on the inner and outer sides of the installation step. The bottom end of the piston pad is provided with a snap-fit ​​step. The bottom end of the dust cover snaps into the snap-fit ​​step.

6. The noise-reducing dual-cavity air spring structure according to claim 3, characterized in that: The mounting plate has a top cover in the middle, the upper end of which extends out of the mounting plate. A retaining spring is provided between the inner side of the mounting plate and the end of the top cover, and a sealing ring is provided at the end of the top cover. A bushing assembly is provided between the top cover and the upper housing. A piston rod is provided inside the outer cylinder of the shock absorber. The piston rod extends out of the outer cylinder of the shock absorber and into the bushing assembly. A nut is connected between the bushing assembly and the top of the piston rod. A buffer block is fitted on the piston rod. The buffer block is located inside the lower housing, and the top of the buffer block is engaged with the upper housing.

7. The noise-reducing dual-cavity air spring structure according to claim 1, characterized in that: The lower housing has a first toothed section at its bottom end and a second toothed section at its top end. Both the first and second toothed sections have a serrated cross-section. The two ends of the bladder skin are in contact with the first and second toothed sections, respectively. The two ends of the bladder skin are fitted with a first and a second clamping ring, respectively, which press the two ends of the bladder skin tightly. The bottom end of the lower housing has a stepped structure, and a steel ring is embedded in the inner side of the bottom end of the lower housing. The upper end of the protective sleeve is fitted over the outside of the bladder skin, and the bottom end of the protective sleeve is engaged with the top end of the dust cover.

8. The noise-reducing dual-cavity air spring structure according to any one of claims 1-7, characterized in that: The upper shell is provided with an upper shell reinforcing rib on its exterior, and the lower shell is provided with a lower shell reinforcing rib on its exterior. The upper shell reinforcing rib has a boss at its end, and the bottom of the boss is higher than the top of the lower shell reinforcing rib.

9. The noise-reducing dual-cavity air spring structure according to claim 8, characterized in that: The upper housing is externally connected to an air transfer channel, which is connected to a pressure holding valve; a stiffness valve is provided inside the upper top seat, and a pad is provided at one end of the stiffness valve inside the upper top seat. A retaining ring is provided on one side of the pad, and a first sealing ring is provided between one end of the stiffness valve and the upper top seat, and a second sealing ring is provided between the other end of the stiffness valve and the upper top seat.

10. The noise-reducing dual-cavity air spring structure according to claim 4, characterized in that: The piston stop is made of a material with a low coefficient of friction.

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