Air spring top rubber and sealing structure thereof

Abstract

The utility model belongs to the technical field of automobile air springs, and particularly relates to air spring top rubber and a sealing structure thereof. The air spring top rubber comprises a framework, a rubber body and a sleeve, wherein a through hole is formed in the framework; the rubber body comprises an outer sealing ring body protruding out of the lower end face of the sleeve, an upper supporting ring body protruding out of the upper end face of the sleeve and a lower supporting ring body protruding out of the lower end face of the outer sealing ring body, the outer circumferential face of the outer sealing ring body is attached to the inner wall of the sleeve, the outer sealing ring body sleeves the lower supporting ring body, and an annular containing cavity is formed between the outer sealing ring body and the lower supporting ring body; the lower supporting ring body is provided with an air duct penetrating through the side wall. The sealing structure comprises the air spring top rubber. The outer sealing ring body of the top rubber on the sealing structure is pressed to be bent inwards and then attached to the step face of the top seat hole, the annular cavity is communicated with the main cavity of the air spring through the air duct, the inwards-bent outer sealing ring body is tightly attached to the step face through the air pressure of the main cavity of the air spring, the air tightness of the sealing structure is enhanced, the structure is simplified, and the service life of the sealing structure is prolonged. Assembling and manufacturing are facilitated, and production efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of automobile air springs, and particularly relates to an air spring top glue and a sealing structure thereof. Background Art

[0002] With the development of the automotive industry, air springs are widely used in automobiles. The rubber airbag of an automotive air spring is filled with compressed air, which uses the compressibility of air to achieve elasticity. By adjusting the internal air pressure, the height and stiffness of the suspension system are changed, allowing the vehicle to better adapt to road conditions and improving vehicle comfort and handling stability. Automotive air springs are usually used in conjunction with shock absorbers. The shock absorber's damping sleeve is set in the air spring's piston and is sealed to the piston. The shock absorber's piston rod passes through the air chamber of the air spring and is sealed to the top seat of the air spring. During vehicle driving, the telescopic end of the piston rod will move up and down and left and right relative to the air spring. Therefore, the sealing connection structure between the top seat of the air spring and the piston rod is particularly important.

[0003] The sealing connection between a traditional air spring and piston rod consists of a top seat with an axially extending stepped hole. The stepped hole houses the coaxially arranged piston rod, a top mount assembly, a nut, and a retaining ring. The piston rod extends through the top mount assembly, and the top mount assembly forms an interference fit with the stepped hole and piston rod, respectively. The bottom end of the top mount assembly abuts against the step in the stepped hole. The nut is positioned above the top mount assembly and is threadedly connected to the piston rod. The retaining ring cooperates with the step in the stepped hole to axially clamp the top mount assembly in place. The surface of the top mount assembly that contacts the piston rod is machined with an annular groove, within which a sealing ring is installed. The rubber and sealing ring of the top mount assembly are used for sealing. Chinese utility model publication number CN218440364U describes a sealing structure for the external connection of an automotive air spring shock absorber. This structure incorporates a sealing ring between the top rubber and the piston rod, as well as between the inner hole sidewall of the inner core weld assembly and the top rubber. Wave-shaped structures are installed at both ends of the top rubber, respectively abutting against the end face of the inner core weld assembly and the top rubber gland. This further enhances the sealing effect of the air spring and piston rod connection. The top rubber comprises an inner and outer rubber skeleton, which are sequentially mounted from the inside out. The wave-shaped structures are located at both ends of the rubber.

[0004] The top glue in the above-mentioned sealing structure must cooperate with the sealing ring to ensure the sealed connection between the shock absorber piston rod and the air spring. The required sealing components are numerous and the processing technology is complicated. The assembly process of the sealing structure is also relatively cumbersome, which wastes manpower, affects the production efficiency of the air spring, and is costly. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide an air spring top rubber and its sealing structure with a simple structure, thereby ensuring a sealed connection between the air spring top seat and the piston rod, reducing the number of sealing elements, improving the air spring assembly efficiency, and saving manpower and production costs.

[0006] The technical solution adopted by the utility model to solve the technical problem is: an air spring top rubber, comprising a skeleton, a rubber body and a sleeve coaxially arranged from the inside to the outside, wherein a through hole is provided at the axis center of the skeleton; the rubber body is an integrally formed structure; the skeleton and the sleeve are respectively vulcanized and bonded to the rubber body;

[0007] The rubber body includes a first outer sealing ring protruding from the lower end surface of the sleeve, an upper support ring body protruding from the upper end surface of the sleeve, and a lower support ring body protruding from the lower end surface of the first outer sealing ring; the first outer sealing ring is located on the inner side of the outer surface of the sleeve, and the outer surface of the first outer sealing ring is vulcanized and sealed with the inner wall of the sleeve; the lower support ring body is located on the inner side of the first outer sealing ring and there is an annular cavity with an opening facing downward between the two, and the lower support ring body is provided with an air duct radially passing through its side wall.

[0008] Furthermore, a transition slope is provided between the end face of the sleeve and the inner side face thereof, and the outer side face of the rubber body is vulcanized and bonded to the transition slope.

[0009] Furthermore, the rubber body further comprises an inner sealing sleeve coaxially arranged below the frame, the inner sealing sleeve being arranged inside the lower support ring body and spaced apart therefrom;

[0010] The inner side surface of the inner sealing sleeve is provided with an inner sealing ring integrally formed therewith.

[0011] Furthermore, the inner sealing ring is a lip-shaped sealing ring.

[0012] Furthermore, a plurality of inner sealing rings are provided, and the plurality of inner sealing rings are arranged along the axial direction.

[0013] Furthermore, an annular groove is provided on the outer side surface of the inner sealing sleeve, and an elastic hoop is provided in the annular groove.

[0014] An air spring sealing structure includes a top seat, wherein a stepped through hole with a thickness of the top and the bottom being tapered is provided at the axis center of the top seat, wherein a piston rod, a nut, and a gland coaxially arranged therewith are provided in the stepped through hole; the piston rod includes a thin rod section and a thick rod section arranged adjacent to each other in upper and lower directions, and the nut is threadedly connected to the thin rod section;

[0015] Any of the above-mentioned air spring top mounts is further provided in the stepped through-hole, the sleeve of the air spring top mount having an interference fit with the stepped through-hole; the thin rod section passes through the through-hole of the frame of the air spring top mount and has a clearance fit therewith; the lower end face of the frame abuts against the upper end face of the thick rod section, and the lower end face of the nut abuts against the upper end face of the frame; an upper sealing ring is provided on the lower end face of the nut, and the thin rod section and the through-hole of the frame are sealed and connected via the upper sealing ring;

[0016] The step surface in the step through hole is perpendicular to the axis of the top seat, the sleeve of the air spring top glue and the lower support ring body both abut against the step surface, the first outer sealing ring is bent inward and fits tightly against the step surface; the pressure cover is axially fixed in the step through hole and abuts against the upper end face of the upper support ring body.

[0017] Furthermore, an air spring top glue having an inner sealing sleeve and an inner sealing ring is used, the thick rod section is located in the inner sealing sleeve and has an interference fit therewith, and the inner sealing sleeve and the thick rod section are sealed and connected via the inner sealing ring.

[0018] Furthermore, the surface roughness Ra of the step surface in the step through hole on the top seat is less than or equal to 1.6 μm; the roughness Ra of the outer peripheral surface of the piston rod in contact with the air spring top rubber is less than or equal to 1.6 μm.

[0019] Furthermore, an annular groove is coaxially provided on the hole wall of the stepped through hole on the top seat, a second outer sealing ring is provided in the annular groove, and the sleeve of the air spring top glue is sealed and connected to the hole wall of the stepped through hole through the second outer sealing ring.

[0020] Compared with the prior art, the present invention has the following beneficial effects: providing an air spring top rubber and its sealing structure, wherein a first outer sealing ring is provided on the rubber body of the top rubber so that when applied to the sealing structure, it bends inward under force and fits against the stepped surface of the top seat upper hole; an air duct is provided on the lower support ring body to connect the annular chamber with the main chamber of the air spring; the gas pressure in the main chamber of the air spring is utilized to tightly fit the inward-bent first outer sealing ring against the stepped surface, thereby improving the airtightness of the top seat sealing structure; the structure is simple, easy to assemble and manufacture, saving manpower, improving the production efficiency of the air spring, and saving manufacturing costs; a downwardly convex inner sealing sleeve is provided on the rubber body and an inner sealing ring is provided on the inner side surface of the inner sealing sleeve so that the piston rod in the sealing structure is sealedly connected to the inner sealing sleeve via the inner sealing ring, ensuring a sealed connection between the piston rod and the top rubber; the inner sealing ring and the inner sealing sleeve are arranged as an integrally formed structure, facilitating assembly of the piston rod and the top rubber; an elastic hoop is provided to clamp the inner sealing sleeve to apply radial preload to the inner sealing sleeve, ensuring a sealed connection between the inner sealing sleeve and the piston rod, thereby improving the reliability of the sealing structure. By setting the outer side surface of the piston rod that contacts the top glue as a smooth plane with a roughness of less than 1.6μm, the piston rod and the top glue are easier to assemble, thereby improving the air tightness of the air spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1-3 They are schematic axial cross-sectional views of different embodiments of air spring top mounts;

[0022] Figure 4 1 is a schematic diagram of an axial cross-sectional structure of an embodiment of an air spring sealing structure;

[0023] Figure 5 for Figure 4 A schematic diagram of the enlarged structure of the middle part A;

[0024] Figure numerals: 1-skeleton; 2-rubber body; 21-first outer sealing ring; 22-upper supporting ring body; 23-lower supporting ring body; 231-air duct; 24-annular cavity; 25-inner sealing sleeve; 26-inner sealing ring; 27-elastic hoop; 3-sleeve; 31-transition slope; 4-top seat; 41-step surface; 5-piston rod; 51-thin rod section; 52-thick rod section; 6-nut; 7-pressure cover; 8-second outer sealing ring. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0026] As attached Figure 1-5As shown, an air spring top rubber comprises a skeleton 1, a rubber body 2, and a sleeve 3 coaxially arranged from inside to outside. The skeleton 1 has a through hole at its axis. The rubber body 2 is an integrally formed structure. The skeleton 1 and the sleeve 3 are vulcanized and bonded to the rubber body 2. The rubber body 2 includes a first outer sealing ring 21 protruding from the lower end surface of the sleeve 3, an upper support ring 22 protruding from the upper end surface of the sleeve 3, and a lower support ring 23 protruding from the lower end surface of the first outer sealing ring 21. The first outer sealing ring 21 is located inside the outer surface of the sleeve 3 and is vulcanized and sealed to the inner wall of the sleeve 3. The lower support ring 23 is located inside the first outer sealing ring 21 and defines a downwardly opening annular cavity 24 between the two. The lower support ring 23 is provided with an air duct 231 radially extending through its sidewall. The first outer sealing ring 21 cannot protrude from the outer surface of the sleeve 3.

[0027] When in use, the air spring top rubber is located in the seat hole of the air spring top seat 4 and the sleeve 3 is interference fit with the seat hole. The piston rod 5 of the shock absorber passes through the through hole on the air spring top rubber frame 1 and is sealed and connected to it. The upper support ring body 22 is pressed by the axial positioning piece so that the lower end face of the sleeve 3 is tightly fitted with the step surface 41 in the seat hole. At this time, the lower support ring body 23 is compressed, and the first outer sealing ring 21, which originally protruded from the lower end of the sleeve 3, is bent inward and deformed under pressure and fits tightly with the step surface 41 in the seat hole. The annular cavity 24 is connected to the main chamber of the air spring through the air duct 231. The gas in the main chamber of the air spring enters the annular cavity 24 and applies pressure to the first outer sealing ring 21 so that it fits tightly with the step surface 41. The greater the air pressure in the main chamber of the air spring, the tighter the first outer sealing ring 21 fits against the step surface 41, and the better the sealing effect, ensuring a sealed connection between the top seal and the step surface 41 of the seat hole, improving the sealing between the top seal of the air spring and the mounting seat 4, eliminating the need for an additional sealing ring between the seat hole and the sleeve 3, reducing sealing elements, simplifying the top seal structure and sealing structure, facilitating assembly, saving manpower, and improving the assembly efficiency of the air spring; accordingly, there is no need to provide an annular groove for installing the sealing ring on the top seat 4 or the top seal, simplifying the part structure, simplifying the part processing process, improving production efficiency, and saving manufacturing costs. The gap between the piston rod 5 and the skeleton 1 can be sealed by providing a sealing ring or a sealing gasket.

[0028] The skeleton 1 and the sleeve 3 cooperate to support the rubber body 2 and enhance the overall strength of the air spring top rubber. The material of the skeleton 1 and the sleeve 3 can be a metal material with high strength and hardness, such as aluminum alloy, stainless steel, or a non-metallic material with high strength and hardness, such as PA66, PA66+GF, etc. PA66 is polyamide 66, also known as nylon 66, and PA66+GF is glass fiber reinforced nylon 66. The skeleton 1 has a variety of structural forms, such as a ring plate structure, a sleeve structure with a ring plate, a regular polygonal plate structure or a cylindrical structure, etc. Its specific structure should be determined according to the overall shape and size of the top rubber and the mechanical properties required by the top rubber. In order to prevent the sleeve 3 from detaching from the rubber body 2, preferably, a transition bevel 31 is provided between the end face of the sleeve 3 and its inner side face, and the outer side face of the rubber body 2 is vulcanized and bonded to the transition bevel 31, thereby increasing the vulcanized bonding area between the rubber body 2 and the sleeve 3 and increasing the reliability of the air spring top rubber.

[0029] The rubber body 2 is used to connect the skeleton 1 and the sleeve 3. The rubber body 2 is elastic, so the skeleton 1 and the sleeve 3 can each be displaced to a certain extent relative to the rubber body 2, thereby limiting the movement of the piston rod 5 within the range limited by the rubber body 2, and playing a role in buffering and vibration reduction. The rubber body 2 is used to seal the skeleton 1 and the sleeve 3. When in use, the lower end of the rubber body 2 is tightly fitted with the step surface 41 to ensure that the top rubber is sealed with the hole wall of the seat hole of the top seat 4. The outer side of the rubber body 2 is vulcanized and bonded to the inner wall of the sleeve 3. The rubber body 2 can completely cover the outer wall of the skeleton 1, or it can only cover a part of the outer wall of the skeleton 1. The rubber body 2 is generally made of a rubber material with excellent elasticity, high temperature resistance, low temperature resistance, and corrosion resistance, such as butadiene rubber, nitrile rubber, EPDM rubber, fluororubber, etc. The first outer sealing ring 21 on the rubber body 2 can be a sealing sleeve, a sealing ring, or a sealing structure composed of a sleeve and a ring body. The sealing sleeve can be a straight cylindrical structure or a cylindrical structure with an inner diameter gradually decreasing from top to bottom; the sealing ring can be a ring body with a cross-section in a circular, triangular, rectangular, or other shape. The upper support ring body 22 and the lower support ring body 23 on the rubber body 2 are used to cooperate with the axial limiting structure to axially pre-tighten the top rubber. The displacement range of the top rubber upper frame 1 and the sleeve 3 can be changed by adjusting the pre-tightening degree of the two support ring bodies. The upper support ring body 22 and the lower support ring body 23 can be an annular structure or a cylindrical structure. The air duct 231 can be a through hole provided on the side wall of the lower support ring body 23 or a groove provided on its end face.

[0030] like Figure 3-5As shown, the rubber body 2 preferably also includes an inner sealing sleeve 25 coaxially arranged below the frame 1. The inner sealing sleeve 25 is positioned inside the lower support ring 23 and spaced apart therefrom. The inner side of the inner sealing sleeve 25 includes an inner sealing ring 26 integrally formed therewith. During use, the shock absorber's piston rod 5 is positioned within the inner sealing sleeve 25. The piston rod 5 is sealed to the inner sealing sleeve 2 via the inner sealing ring 26, ensuring a sealed connection between the piston rod 5 and the top rubber, thereby improving the airtightness of the air spring. The outer diameter of the inner sealing sleeve 25 should be smaller than the minimum aperture of the top seat 4. That is, there should be a gap between the inner sealing sleeve 25 and the seat aperture wall to ensure communication between the main chamber of the air spring and the annular cavity 24. Similarly, the air pressure in the main chamber of the air spring also acts on the inner sealing sleeve 25, ensuring a tight fit between it and the piston rod 5. Furthermore, the inner sealing ring 26 and the inner sealing sleeve 25 are integrally formed to facilitate assembly of the piston rod 5 and the top rubber.

[0031] The inner sealing ring 26 can be a common O-ring or rectangular sealing ring. Preferably, the inner sealing ring 26 is a lip-shaped sealing ring, which can be a Y-ring, U-ring, V-ring, etc. The lip-shaped sealing ring deforms under the action of gas pressure, so that the lip is in close contact with the piston rod 5. The greater the gas pressure, the tighter the lip fits the piston rod 5, ensuring a sealed connection between the piston rod 5 and the top rubber. In addition, the sealing lip has a certain compensation ability after wear, extending the service life of the sealing ring. The sealing ring 26 can be provided as a single one or multiple ones. Preferably, the inner sealing ring 26 is provided as a plurality, and the multiple inner sealing rings 26 are arranged axially to further ensure a sealed connection between the piston rod 5 and the inner sealing sleeve 25 on the top rubber. As a further preferred embodiment, the outer side of the inner sealing sleeve 25 is provided with an annular groove, and an elastic hoop 27 is provided in the annular groove. The annular groove is used to axially limit the elastic hoop 27. The elastic hoop 27 applies radial pre-pressure to the inner sealing sleeve 25, further ensuring a sealed connection between the inner sealing sleeve 25 and the piston rod 5.

[0032] An air spring sealing structure includes a top seat 4, a stepped through hole with a thickness of the upper part and the lower part is provided at the axis center of the top seat 4, a piston rod 5, a nut 6 and a pressure cover 7 coaxial therewith are provided in the stepped through hole; the piston rod 5 includes a thin rod section 51 and a thick rod section 52 arranged adjacent to each other in the upper and lower parts, the nut 6 is threadedly connected to the thin rod section 51; any of the above-mentioned air spring top glues is also provided in the stepped through hole, the sleeve 3 of the air spring top glue is interference fit with the stepped through hole, the thin rod section 51 passes through the through hole of the skeleton 1 of the air spring top glue and is clearance fit therewith; the lower end surface of the skeleton 1 abuts against Connected to the upper end face of the thick rod section 52, the lower end face of the nut 6 abuts against the upper end face of the skeleton 1; the lower end face of the nut 6 is provided with an upper sealing ring, and the thin rod section 51 and the through hole of the skeleton 1 are sealed and connected via the upper sealing ring; the step surface 41 in the step through hole is perpendicular to the axis of the top seat 4, and the sleeve 3 and the lower support ring body 23 of the air spring top glue are both abutted against the step surface 41, and the first outer sealing ring 21 is bent inward and fits tightly against the step surface 41; the pressure cover 7 is fixed in the step through hole and abuts against the upper end face of the upper support ring body 22.

[0033] The top seat 4 is sealed and connected to the airbag of the air spring to support the vehicle suspension. The upper end surface of the thick rod section 52 cooperates with the nut 6 to axially position the air spring top rubber and connect it to the thin rod section 51 of the piston rod 5. The pressure cap 7 and the step surface 41 cooperate to axially pre-compress the rubber body 2, and the step through hole radially positions the air spring top rubber, thereby ensuring that the shock absorber piston rod 5 moves radially and axially under the restriction of the rubber body 2. The pressure cap 7 can be a cover structure or a ring plate structure. In order to facilitate the assembly and disassembly of the nut 6, the pressure cap 7 is generally an annular structure. The pressure cap 7 can be threadedly connected to the hole wall of the step through hole, or it can be connected by bolts, pins and other connecting parts. An annular retaining ring groove can also be set on the side wall of the step through hole. The retaining ring groove is located above the pressure cap 7. The pressure cap 7 is axially limited by a retaining ring through the installation hole in the retaining ring groove, so that the pressure cap 7 presses the upper support ring body 22 downward. The air spring sealing structure described in the utility model simplifies the sealing structure, reduces the number of sealing parts, facilitates manufacturing and assembly, saves manpower, and improves the air spring assembly efficiency while ensuring the sealing performance.

[0034] like Figure 4-5 As shown, when an air spring top glue with an inner sealing sleeve 25 and an elastic hoop 27 is used, the thick rod section 52 is located in the inner sealing sleeve 25 and has an interference fit therewith. The inner sealing sleeve 25 and the thick rod section 52 are sealed and connected via the inner sealing ring 26. The elastic hoop 27 can also be used to clamp the inner sealing sleeve 25 onto the piston rod 5. Even if the inner sealing ring 26 is damaged, the inner sealing sleeve 25 is still sealed and connected to the piston rod 5, which is safe and reliable.

[0035] Preferably, the surface roughness Ra of the step surface 41 of the step through hole on the top seat 4 is less than or equal to 1.6 μm, which further makes the first outer sealing ring 21 and the lower end surface of the sleeve 3 tightly connected to the step surface 41; the roughness Ra of the outer peripheral surface of the piston rod 5 in contact with the air spring top glue is less than or equal to 1.6 μm, the surface of the piston rod 5 is smooth, the assembly is labor-saving, and it further ensures that the piston rod 5 is tightly connected to the top glue, thereby improving the air tightness of the sealing structure.

[0036] As a further preferred embodiment, an annular groove may be coaxially provided on the wall of the stepped through hole of the top seat 4. A second outer sealing ring 8 is provided in the annular groove. The sleeve 3 of the air spring top seal is sealed to the wall of the stepped through hole via the second outer sealing ring 8. This prevents air leakage from the sealing structure after damage to the first outer sealing ring 21, thereby improving the reliability of the sealing structure and the air spring. The second outer sealing ring 8 may be an O-ring or a lip-shaped sealing ring.

[0037] The embodiments of this specific implementation method are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention. In the description of the present invention, the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present invention.

Claims

1. An air spring top rubber, comprising a skeleton (1), a rubber body (2) and a sleeve (3) coaxially arranged from the inside to the outside, wherein a through hole is provided at the axis center of the skeleton (1); the rubber body (2) is an integrally formed structure; the skeleton (1) and the sleeve (3) are respectively vulcanized and bonded to the rubber body (2); and characterized in that: The rubber body (2) comprises a first outer sealing ring (21) protruding from the lower end face of the sleeve (3), an upper support ring body (22) protruding from the upper end face of the sleeve (3), and a lower support ring body (23) protruding from the lower end face of the first outer sealing ring (21); the first outer sealing ring (21) is located on the inner side of the outer side face of the sleeve (3), and the outer side face of the first outer sealing ring (21) is vulcanized and sealed with the inner wall of the sleeve (3); the lower support ring body (23) is located on the inner side of the first outer sealing ring (21) and an annular cavity (24) with an opening facing downward is provided between the two, and an air duct (231) is provided on the lower support ring body (23) which radially passes through its side wall.

2. The air spring top seal according to claim 1, characterized in that: A transition slope (31) is provided between the end surface of the sleeve (3) and its inner side surface, and the outer side surface of the rubber body (2) is vulcanized and bonded to the transition slope (31).

3. The air spring top sealant according to claim 1, characterized in that: The rubber body (2) further comprises an inner sealing sleeve (25) coaxially arranged below the skeleton (1), wherein the inner sealing sleeve (25) is arranged inside the lower support ring body (23) and spaced apart therefrom; The inner side surface of the inner sealing sleeve (25) has an inner sealing ring (26) integrally formed therewith.

4. The air spring top seal according to claim 3, characterized in that: The inner sealing ring (26) is a lip-shaped sealing ring.

5. The air spring top seal according to claim 3, characterized in that: A plurality of inner sealing rings (26) are provided, and the plurality of inner sealing rings (26) are arranged along the axial direction.

6. The air spring top sealant according to claim 3, characterized in that: An annular groove is provided on the outer side surface of the inner sealing sleeve (25), and an elastic hoop (27) is provided in the annular groove.

7. An air spring sealing structure, comprising a top seat (4), wherein a stepped through hole with a thickness of the top and a thickness of the bottom is provided at the axis center of the top seat (4), wherein a piston rod (5), a nut (6) and a gland (7) coaxially therewith are provided in the stepped through hole; the piston rod (5) comprises a thin rod section (51) and a thick rod section (52) arranged adjacent to each other in the upper and lower directions, and the nut (6) is threadedly connected to the thin rod section (51); and characterized in that: The step through hole is further provided with an air spring top glue as claimed in any one of claims 1 to 6, the sleeve (3) of the air spring top glue is interference-fitted with the step through hole, and the thin rod section (51) passes through the through hole of the skeleton (1) of the air spring top glue and is clearance-fitted therewith; the lower end face of the skeleton (1) abuts against the upper end face of the thick rod section (52), and the lower end face of the nut (6) abuts against the upper end face of the skeleton (1); the lower end face of the nut (6) is provided with an upper sealing ring, and the thin rod section (51) and the through hole of the skeleton (1) are sealed and connected via the upper sealing ring; The step surface (41) in the step through hole is perpendicular to the axis of the top seat (4); the sleeve (3) of the air spring top glue and the lower support ring body (23) are both in contact with the step surface (41); the first outer sealing ring (21) is bent inward and fits tightly with the step surface (41); the pressure cover (7) is axially fixed in the step through hole and in contact with the upper end face of the upper support ring body (22).

8. The air spring sealing structure according to claim 7, characterized in that: The air spring top glue as claimed in claim 3 is used, the thick rod section (52) is located in the inner sealing sleeve (25) and is interference fit therewith, and the inner sealing sleeve (25) and the thick rod section (52) are sealed and connected via the inner sealing ring (26).

9. The air spring sealing structure according to claim 7, characterized in that: The surface roughness Ra of the step surface (41) of the step through hole on the top seat (4) is less than or equal to 1.6 μm; the surface roughness Ra of the outer peripheral surface of the piston rod (5) in contact with the air spring top rubber is less than or equal to 1.6 μm.

10. The air spring sealing structure according to claim 7, wherein: An annular groove is coaxially provided on the wall of the stepped through hole on the top seat (4), a second outer sealing ring (8) is provided in the annular groove, and the sleeve (3) of the air spring top glue is sealedly connected to the wall of the stepped through hole via the second outer sealing ring (8).

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