Air spring top rubber and sealing structure thereof

Abstract

The invention 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 invention belongs to the technical field of automobile air springs, and in particular relates to an air spring top rubber and a sealing structure thereof. Background Art

[0002] With the development of the automobile industry, air springs are widely used in automobiles. The rubber airbag of the automotive air spring is filled with compressed air, which uses the compressibility of air to achieve elasticity. By adjusting its internal air pressure, the height and stiffness of the suspension system are changed, so that the vehicle can better adapt to road conditions and improve the comfort and handling stability of the vehicle. Automotive air springs are usually used in conjunction with shock absorbers. The shock-absorbing sleeve of the shock absorber is set in the piston of the air spring and is sealed with the piston. The piston rod of the shock absorber passes through the gas chamber of the air spring and is sealed with the top seat of the air spring. During the driving process of the vehicle, the telescopic end of the piston rod will move up, down, 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 structure between the traditional air spring and the piston rod includes a top seat, which has an axially penetrating step hole. The step hole is provided with a piston rod, a top rubber assembly, a nut and a retaining ring arranged coaxially therewith. The piston rod passes through the top rubber assembly, and the top rubber assembly is respectively interference fit with the step hole and the piston rod. The lower end face of the top rubber assembly abuts against the step of the step hole, and the nut is arranged above the top rubber assembly and is threadedly connected to the piston rod. The retaining ring cooperates with the step in the step hole to clamp the top rubber assembly axially and position it. An annular groove is machined on the surface of the top rubber assembly in contact with the piston rod, and a sealing ring is installed in the annular groove, and the rubber and sealing ring of the top rubber assembly itself are used for sealing. The Chinese utility model with publication number CN218440364U records an external connection sealing structure of an automobile air spring shock absorber, which not only sets a sealing ring between the top rubber and the piston rod, but also sets a sealing ring between the inner hole side wall of the inner core welding assembly and the top rubber, and sets a wavy structure at both ends of the top rubber, which abuts against the end face of the inner core welding assembly and the top rubber gland, further improving the sealing effect of the sealing connection structure between the air spring and the piston rod. Among them, the top rubber includes an inner skeleton rubber and an outer skeleton that are sequentially mounted from the inside to the outside, and the wavy structure is set at both ends of the rubber.

[0004] The top rubber 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 large in number 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. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an air spring top rubber and its sealing structure with a simple structure, so as to ensure the sealing connection between the air spring top seat and the piston rod, reduce the number of sealing elements, improve the air spring assembly efficiency, and save manpower and production costs.

[0006] The technical solution adopted by the present invention 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 of the skeleton; the rubber body is an integral structure formed in one piece; 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 supporting ring body protruding from the upper end surface of the sleeve, and a lower supporting 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 supporting 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 supporting ring body is provided with an air duct radially penetrating its side wall.

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

[0009] Furthermore, the rubber body also includes an inner sealing sleeve coaxially arranged below the frame, and the inner sealing sleeve is arranged inside the lower support ring body and spaced apart from the lower support ring body;

[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 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 comprises a top seat, wherein a stepped through hole with a thickness at the top and a thickness at the bottom is provided at the axis center of the top seat, wherein a piston rod, a nut and a gland coaxial with the stepped through hole are provided in the stepped through hole; the piston rod comprises a thin rod section and a thick rod section arranged adjacent to each other in the upper and lower parts, and the nut is threadedly connected to the thin rod section;

[0015] Any of the above-mentioned air spring top glues is also arranged in the step through hole, and the sleeve of the air spring top glue is interference fit with the step through hole; the thin rod section passes through the through hole of the skeleton of the air spring top glue and is gap fit with it; the lower end surface of the skeleton abuts against the upper end surface of the thick rod section, and the lower end surface of the nut abuts against the upper end surface of the skeleton; the lower end surface of the nut is provided with an upper sealing ring, and the thin rod section and the through hole of the skeleton are sealed and connected through 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 rubber 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 surface of the upper support ring body.

[0017] Furthermore, an air spring top rubber having an inner sealing sleeve and an inner sealing ring is used, the thick rod section is located in the inner sealing sleeve and is interference fit therewith, and the inner sealing sleeve and the thick rod section are sealingly 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 on the piston rod that contacts 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 rubber 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 beneficial effects of the present invention are as follows: providing an air spring top rubber and its sealing structure, by arranging a first outer sealing ring on the top rubber rubber body so that when it is applied to the sealing structure, it bends inward under force and fits with the step surface of the top seat upper seat hole, by arranging an air passage on the lower support ring body so that the annular chamber is connected with the main chamber of the air spring, and the gas pressure of the main chamber of the air spring is used to make the first outer sealing ring that bends inward fit closely with the step surface, thereby improving the air tightness 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. By arranging a downward convex inner sealing sleeve on the rubber body and arranging an inner sealing ring on the inner side of the inner sealing sleeve, the piston rod in the sealing structure is sealed and connected with the inner sealing sleeve through the inner sealing ring, ensuring the sealing 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, which facilitates the assembly of the piston rod and the top rubber. By arranging an elastic hoop connected to the inner sealing sleeve, a radial pre-pressure is applied to the inner sealing sleeve, ensuring the sealing connection between the inner sealing sleeve and the piston rod, and improving the reliability of the sealing structure. By setting the outer side surface of the piston rod in contact with the top rubber as a smooth plane with a roughness less than 1.6 μm, the piston rod and the top rubber 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 rubbers;

[0022] Figure 4 is an axial cross-sectional structural schematic diagram 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 is further described below in conjunction with 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 which are coaxially arranged from the inside to the outside, a through hole is provided at the axis center of the skeleton 1; the rubber body 2 is an integral structure formed in one piece; the skeleton 1 and the sleeve 3 are respectively vulcanized and bonded to the rubber body 2; 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 and bonded to 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 there is an annular cavity 24 with an opening facing downwards between the two, and an air passage 231 radially penetrating through its side wall is provided on the lower support ring body 23. The first outer sealing ring 21 cannot protrude from the outer side face 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 skeleton 1 and is sealed and connected thereto, and 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 that originally protrudes from the lower end of the sleeve 3 is bent inwardly after being compressed and is tightly fitted 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 is tightly fitted 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 with the step surface 41, and the better the sealing effect, ensuring the sealing connection between the top rubber and the step surface 41 of the seat hole, improving the sealing between the top rubber of the air spring and the mounting seat 4, and no need to install an additional sealing ring between the seat hole and the sleeve 3, reducing the sealing elements, simplifying the top rubber structure and the sealing structure, facilitating assembly, saving manpower, and improving the assembly efficiency of the air spring; accordingly, there is no need to set an annular groove for installing the sealing ring on the top seat 4 or the top rubber, simplifying the part structure, simplifying the part processing technology, improving production efficiency, and saving manufacturing costs. The gap between the piston rod 5 and the skeleton 1 can be blocked by setting a sealing ring or a sealing gasket.

[0028] The skeleton 1 and the sleeve 3 cooperate to support the rubber body 2 to enhance the overall strength of the air spring top rubber. The skeleton 1 and the sleeve 3 can be made of metal materials with high strength and hardness such as aluminum alloy and stainless steel, or non-metal materials with high strength and hardness such as PA66 and PA66+GF. 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 an annular plate structure, a sleeve structure with an annular plate, a regular polygonal plate structure or a cylindrical structure, etc. Its specific structure should be determined according to the overall shape, size and mechanical properties required by the top rubber. In order to prevent the sleeve 3 from being separated from the rubber body 2, preferably, a transition slope 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 slope 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 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 fits tightly with the step surface 41 to ensure that the top rubber and the hole wall of the seat hole of the top seat 4 are sealed. The outer side surface 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 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, wherein the sealing sleeve can be a straight cylinder structure, or a cylinder 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, and 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, and the air passage 231 can be a through hole arranged on the side wall of the lower support ring body 23, or a groove arranged on its end face.

[0030] like Figure 3-5As shown, preferably, the rubber body 2 also includes an inner sealing sleeve 25 coaxially arranged below the skeleton 1, and the inner sealing sleeve 25 is arranged inside the lower support ring body 23 and spaced therefrom; the inner side surface of the inner sealing sleeve 25 has an inner sealing ring 26 integrally formed therewith. When in use, the piston rod 5 of the shock absorber is located in the inner sealing sleeve 25, and the piston rod 5 is sealed and connected to the inner sealing sleeve 2 through the inner sealing ring 26, so as to ensure the sealing connection between the piston rod 5 and the top rubber, and improve the air tightness of the air spring. The outer diameter of the inner sealing sleeve 25 should be smaller than the minimum aperture of the seat hole of the top seat 4, that is, there is a gap between the inner sealing sleeve 25 and the seat hole wall, so as to ensure that the main chamber of the air spring is connected to the annular cavity 24. Similarly, the air pressure of the main chamber of the air spring will also act on the inner sealing sleeve 25, so that it fits tightly with the piston rod 5. In addition, the inner sealing ring 26 and the inner sealing sleeve 25 are set as an integrally formed structure, which is convenient for the 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 sealing ring, which can be a Y-ring, a U-ring, a V-ring, etc. The lip sealing ring deforms under the action of gas pressure, so that the lip is close to the piston rod 5. The greater the gas pressure, the tighter the lip fits the piston rod 5, ensuring the sealing 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. One sealing ring 26 can be set, or multiple sealing rings can be set. Preferably, multiple inner sealing rings 26 are set, and multiple inner sealing rings 26 are arranged axially to further ensure the sealing connection between the piston rod 5 and the inner sealing sleeve 25 on the top rubber. As a further preference, 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 limit the elastic hoop 27 axially, and the elastic hoop 27 applies radial pre-pressure to the inner sealing sleeve 25, further ensuring the sealing connection between the inner sealing sleeve 25 and the piston rod 5.

[0032] An air spring sealing structure, comprising a top seat 4, wherein the top seat 4 is provided with a stepped through hole which is thick at the top and thin at the bottom at the axis center, wherein a piston rod 5, a nut 6 and a gland 7 coaxial therewith are provided in the stepped through hole; wherein 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 parts, wherein the nut 6 is threadedly connected to the thin rod section 51; wherein any one of the above-mentioned air spring top glues is also provided in the stepped through hole, wherein the sleeve 3 of the air spring top glue has an interference fit with the stepped through hole, wherein the thin rod section 51 passes through the through hole of the skeleton 1 of the air spring top glue and has a clearance fit therewith; wherein 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; an upper sealing ring is provided on the lower end face of the nut 6, 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 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 up and down 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 up and down to axially pre-compress and position 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 generally adopts 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 spring groove can also be set on the side wall of the step through hole. The retaining spring groove is located above the pressure cap 7. The pressure cap 7 is axially limited by a retaining spring installed in the retaining spring groove, so that the pressure cap 7 presses the upper support ring body 22 downward. The air spring sealing structure described in the present invention 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 rubber 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 is 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 1.6μm, 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 1.6μm, the surface of the piston rod 5 is smooth, the assembly is labor-saving, and it also 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 preference, an annular groove may be coaxially arranged on the hole wall of the step through hole of the top seat 4, a second outer sealing ring 8 is arranged in the annular groove, and the sleeve 3 of the air spring top rubber is sealed and connected to the hole wall of the step through hole through the second outer sealing ring 8, so as to avoid leakage of the sealing structure after the first outer sealing ring 21 is damaged, 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 mode are all preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby. Therefore, any equivalent changes made according to the structure, shape, and principle of the present invention should be included in the protection scope of the present invention. In the description of the present invention, the orientation or position relationship indicated by the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

Claims

1. An air spring top rubber, comprising a frame (1), a rubber body (2) and a sleeve (3) coaxially arranged from inside to outside, wherein a through hole is provided at the axis center of the frame (1); the rubber body (2) is an integral structure formed in one piece; the frame (1) and the sleeve (3) are respectively bonded to the rubber body (2) by vulcanization; and characterized in that: The rubber body (2) comprises a first outer sealing ring (21) protruding from the lower end surface of the sleeve (3), an upper supporting ring body (22) protruding from the upper end surface of the sleeve (3), and a lower supporting ring body (23) protruding from the lower end surface of the first outer sealing ring (21); the first outer sealing ring (21) is located on the inner side of the outer side surface of the sleeve (3), and the outer side surface of the first outer sealing ring (21) is vulcanized and sealed with the inner wall of the sleeve (3); the lower supporting ring body (23) is located on the inner side of the first outer sealing ring (21) and there is an annular cavity (24) with an opening facing downwards between the two, and the lower supporting ring body (23) is provided with an air passage (231) radially penetrating its side wall.

2. The air spring top rubber 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 rubber according to claim 1, characterized in that: The rubber body (2) further comprises an inner sealing sleeve (25) coaxially arranged below the frame (1); the inner sealing sleeve (25) is arranged inside the lower supporting 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 rubber according to claim 3, characterized in that: The inner sealing ring (26) is a lip sealing ring.

5. The air spring top rubber 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 rubber 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 thick upper portion and a thin lower portion 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 parts, and the nut (6) is threadedly connected to the thin rod section (51); and characterized in that: The step through hole is also 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 fit with the step 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 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 rubber 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 surface 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, characterized in that: An annular groove is coaxially arranged on the hole wall of the stepped through hole on the top seat (4), a second outer sealing ring (8) is arranged in the annular groove, and the sleeve (3) of the air spring top rubber is sealedly connected to the hole wall of the stepped through hole via the second outer sealing ring (8).

Images