A compact air spring

Abstract

The present invention relates to the technical field of air springs, and in particular, to a compact air spring, comprising: a bladder skin, an upper seat, a piston, a shock absorber, a casing and a bushing, wherein the casing is sleeved on the outside of the bladder skin, the upper end of the casing is connected to the top of the bladder skin and fixed to the upper fixed portion; the shock absorber comprises a shock absorber outer cylinder, the piston is coaxially arranged with the shock absorber outer cylinder, and there is a spacing space between the inner circumference of the piston and the outer circumference of the shock absorber outer cylinder; the bushing is annular, the inner ring surface of the bushing is sealed and connected to the outer circumference of the shock absorber outer cylinder, the outer ring surface of the bushing fits with the inner circumference of the piston, so that the bushing can partially fill the spacing space in the axial direction; the bushing is provided with a flexible portion coaxially arranged with the bushing and in an annular shape. In this way, the problem that the air spring has a complex structure and the bladder skin is partially exposed to the outside and easily damaged is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of air springs, and in particular to a compact air spring. Background Art

[0002] The air spring is a sealed container filled with compressed air, which uses the compressibility of gas to achieve its elastic effect. The air spring has ideal nonlinear elastic characteristics. After the height adjustment device is installed, the height of the vehicle body does not change with the increase or decrease of the load. The spring stiffness can be designed to be lower, and the ride comfort is good.

[0003] In the prior art, a portion of the bladder skin of the front air spring is usually exposed to the area between the protective tube and the upper top seat. This portion is mainly used to provide a space for the air spring to be twisted to a certain extent. However, this exposed portion also makes it easy to be damaged when subjected to external impacts, etc. However, directly protecting it with components will limit this portion of the bladder skin and also make the air spring lose the ability to be twisted to a certain extent. In addition, in the existing front air spring, the sealing structure of the lower end of the inflation cavity is relatively complex, and the fixing structure of the protective tube is also relatively complex, which not only has many parts, but also is complicated to assemble. Summary of the invention

[0004] In order to solve the problem that the air spring has a complex structure and a bladder skin is partially exposed to the outside and easily damaged, the present invention provides a compact air spring, comprising: a bladder skin, which is made of elastic material, is annular and has an inflatable cavity arranged inside; an upper top seat, which is provided with an upper fixing portion, and the top end of the bladder skin can be sealed and installed on the upper fixing portion; a protective tube, which is sleeved on the outside of the bladder skin, and the upper end of the protective tube is connected to the top end of the bladder skin and fixed to the upper fixing portion; a piston, which is arranged on the lower side of the inflatable cavity, and the top of the piston is provided with a lower fixing portion for fixing the bottom end of the bladder skin. The bottom end of the bladder skin is sealed and connected to the lower fixed part; the shock absorber, the shock absorber passes through the inflation cavity and is connected to the upper top seat through an elastic seal, the shock absorber includes a shock absorber outer tube, the piston is coaxially arranged with the shock absorber outer tube, and there is a spacing space between the inner circumference of the piston and the outer circumference of the shock absorber outer tube; the bushing is annular, the inner ring surface of the bushing is sealed and connected to the outer circumference of the shock absorber outer tube, the outer ring surface of the bushing fits with the inner circumference of the piston, so that the bushing can partially fill the spacing space along the axial direction; the bushing is provided with a flexible portion which is coaxially arranged with the bushing and is annular.

[0005] In some embodiments, the inner annular surface is sealingly connected to the upper portion of the outer circumferential surface of the shock absorber outer tube, and the outer annular surface is sealingly connected to the upper portion of the inner circumferential surface of the piston.

[0006] In some embodiments, the shock absorber also includes a fixed sleeve, which includes a top support portion, an extension portion and a supporting portion. The bottom surface of the support portion is fitted on the top surface of the outer tube of the shock absorber, the extension portion extends downward from the edge of the support portion, the supporting portion is annular, the inner annular surface of the supporting portion is connected to the outer side surface of the extension portion, and the supporting portion also includes a supporting surface arranged in the direction of the inflation cavity; the bushing is fixed to the outer tube of the shock absorber by the fixed sleeve, and the bottom surface of the bushing is fitted with the supporting surface.

[0007] In some embodiments, the piston also includes a lower pressing ring, which is sleeved on the outside of the lower fixing portion. The lower pressing ring can generate a clamping force toward the central axis of the lower pressing ring and can fix the bottom end of the bladder skin to the lower fixing portion.

[0008] In some embodiments, the lower pressing ring can push the lower fixing portion to press against the bushing.

[0009] In some embodiments, the bushing includes an outer ring portion and an inner ring portion, the outer ring surface is arranged on the outer ring portion, the inner ring surface is arranged on the inner ring surface, the outer ring portion and the inner ring portion are made of hard material, the outer ring portion is sleeved on the outer side of the flexible portion, and the inner ring portion is arranged on the inner side of the flexible portion; the outer ring portion, the inner ring portion and the flexible portion are coaxially arranged and integrated.

[0010] In some embodiments, the outer ring surface is provided with an outer sealing groove, which is circumferentially arranged around the outer ring surface, and the opening of the outer sealing groove faces the inner circumferential surface of the piston; the sleeve also includes an outer sealing ring, which matches the outer sealing groove, and the outer sealing ring can partially protrude from the outer ring surface.

[0011] In some embodiments, the inner ring surface is provided with an inner sealing groove, which is arranged circumferentially along the inner ring surface, and the opening of the inner sealing groove faces the inner circumferential surface of the piston. The bushing also includes an inner sealing ring, which matches the inner sealing groove, and the inner sealing ring can partially protrude from the inner ring surface.

[0012] In some embodiments, a buckling portion is provided on the upper portion of the protective tube, and the buckling portion can be attached to the top end of the bladder skin under the action of an external force, and exert a buckling pressure toward the central axis on the top end of the bladder skin.

[0013] In some embodiments, the protective tube further comprises an upper buckling ring, which is sleeved on the outer side of the upper portion of the protective tube. The upper buckling ring can squeeze the buckling portion and the top end of the bladder skin and be fixed to the upper fixing portion.

[0014] In order to solve the problem that the air spring has a complex structure and the air spring skin is partially exposed to the outside and easily damaged, the present invention has the following advantages:

[0015] First, by directly connecting the protective tube with the upper top seat, the outer side of the bladder skin can be covered in the space inside the protective tube, thereby effectively preventing the problem of damage caused by part of the bladder skin being exposed to the outside and being easily impacted by foreign objects. At the same time, since the conventional air spring utilizes the mobility of the partially exposed (unconstrained) bladder skin, it is ensured that the shock absorber can twist relative to the upper top seat fixed to the vehicle body within a certain range. However, in the present application, the protective tube covers the bladder skin on the inside, resulting in the originally movable part of the bladder skin being restricted by the protective tube, which will make the shock absorber lose the ability to twist. In order to solve the above problems, the present application also utilizes the setting of the bushing. Since the bushing includes a flexible part, that is, this part has a certain twisting ability, and this structure replaces the original fixed sealing structure between the shock absorber and the piston, the shock absorber can be twisted relative to the piston to a certain extent, so that the shock absorber can still obtain the ability to twist, and the setting of the bushing simplifies the original sealing structure at the lower end of the inflation cavity, thereby simplifying the structure of the air spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic cross-sectional structure diagram of a compact air spring according to an embodiment is shown;

[0017] Figure 2 Shows Figure 1 The partial enlarged structure diagram of the middle A part;

[0018] Figure 3 Shows Figure 1 A partial enlarged structural diagram of the middle B part;

[0019] Figure 4 A schematic structural diagram of a bushing according to an embodiment is shown;

[0020] Figure 5 A schematic cross-sectional structure diagram of a bushing according to an embodiment is shown.

[0021] Figure markings: 10-bladder skin; 11-inflatable cavity; 20-upper seat; 21-upper fixing part; 30-casing; 31-buckle part; 40-shock absorber; 41-shock absorber outer tube; 42-fixing sleeve; 421-support part; 422-extension part; 423-support part; 50-piston; 51-lower fixing part; 60-bushing; 61-flexible part; 62-outer ring part; 621-outer sealing groove; 63-inner ring part; 631-inner sealing groove; 64-outer sealing ring; 65-inner sealing ring; 70-elastic sealing member; 80-lower buckling ring; 90-dust cover. DETAILED DESCRIPTION

[0022] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, rather than implying any limitation on the scope of the present disclosure.

[0023] As used herein, the term "including" and its variants are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal" and the like is based on the orientation or position relationship shown in the accompanying drawings. These terms are mainly for better describing the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. In addition, in addition to being used to indicate an orientation or position relationship, some of the above terms may also be used to indicate other meanings, such as the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to the specific circumstances. In addition, the terms "install", "set", "provided with", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0024] This embodiment discloses a charging pile, such as Figures 1 to 5As shown, it may include: a bladder skin 10, which is made of elastic material, is annular and has an inflatable cavity 11 disposed therein; an upper top seat, which is provided with an upper fixing portion 21, and the top of the bladder skin 10 can be sealed and installed on the upper fixing portion 21; a protective tube 30, which is sleeved on the outside of the bladder skin 10, and the upper end of the protective tube 30 is connected to the top of the bladder skin 10 and fixed to the upper fixing portion 21; a piston 50, which is disposed on the lower side of the inflatable cavity 11, and the top of the piston 50 is provided with a lower fixing portion 51 for fixing the bottom end of the bladder skin 10, and the bottom end of the bladder skin 10 is sealed and connected to the lower fixing portion 51; a shock absorber 40 The shock absorber 40 passes through the inflation cavity 11 and is connected to the upper seat through an elastic seal 70. The shock absorber 40 includes an outer tube of the shock absorber 40. The piston 50 is coaxially arranged with the outer tube of the shock absorber 40, and there is a spacing space between the inner circumference of the piston 50 and the outer circumference of the outer tube of the shock absorber 40; the bushing 60 is annular, and the inner ring surface of the bushing 60 is sealingly connected to the outer circumference of the outer tube of the shock absorber 40. The outer ring surface of the bushing 60 is in contact with the inner circumference of the piston 50, so that the bushing 60 can partially fill the spacing space along the axial direction; the bushing 60 is provided with a flexible portion 61 which is coaxially arranged with the bushing 60 and is annular.

[0025] It should be noted that the above-mentioned technical solution of the present application is mainly applied to the front air spring of the vehicle, wherein the bladder skin 10 is usually made of elastic materials such as rubber, and its two ends are sealed and connected to other components to form a sealed inflation cavity 11 inside. The inflation cavity 11 can accommodate pressurized gas and can drive its capacity to expand or shrink by changing the gas pressure to further adjust its height. In order to make it have a certain rigidity and enhance its strength, structures such as metal wires or metal meshes are usually buried inside the material. The casing 30 is usually made of aluminum material and is a relatively light and thin cylindrical structure. Its inner wall is directly in contact with the bladder skin 10 and limits the expansion of the bladder skin 10 in the radial direction. When the volume of the inflation cavity 11 in the bladder skin 10 changes, it will change along the axial direction of the casing 30 rather than the radial direction, thereby achieving the purpose of adjusting the height of the inflation cavity 11; in the prior art, the upper part of the casing 30 is usually fixed to the middle part of the bladder skin 10 by a buckling ring arranged inside the bladder skin 10, so that part of the bladder skin 10 between the top of the casing 30 and the fixed position of the top of the bladder skin 10 is exposed to the outside and is not restricted by the casing 30. Therefore, this part of the bladder skin 10 can undergo torsional deformation within a certain range. The piston 50 is arranged at the bottom of the air-filled cavity 11. Since the upper end of the air spring is connected to the vehicle body through the upper top seat, that is, it is fixedly arranged, and the lower part is connected to the wheel of the vehicle, when the air-filled cavity 11 expands, the piston 50 will move away from the upper top seat, and when the air-filled cavity 11 contracts, the piston 50 will move toward the upper top seat. The upper part of the shock absorber 40 is arranged to penetrate the air-filled cavity 11 and is sealed to the upper top seat through an elastic member. Therefore, in the prior art, the air spring uses the elastic member used to connect the shock absorber 40 to the upper top seat and the elastic deformation of the exposed bladder skin 10, so that the lower piston 50, shock absorber 40 and other structures can be twisted relative to the upper top seat. This twisting is a design requirement of the vehicle's suspension system, and the twisting angle is usually very small.

[0026] In the above technical solution, the protective tube 30 is directly connected to the upper top seat, so that the outer side of the bladder skin 10 can be covered in the space inside the protective tube 30, thereby effectively preventing part of the bladder skin 10 from being exposed to the outside, thereby solving the problem that the exposed part of the bladder skin 10 is easily damaged by the impact of foreign objects. Compared with the method of adding a protective cover, since the simple protective cover does not need to limit the activity of the exposed bladder skin 10, the radial volume of the protective tube 30 will be increased, and the protective tube 30 in the present application does not need to be avoided. In addition, since the protective tube 30 is directly connected to the upper top seat, the structure such as the buckling ring used to fix the protective tube 30 is also eliminated. While simplifying the structure of the protective tube 30, it also saves the setting of some parts and simplifies the structure of the air spring. At the same time, the conventional air spring utilizes the mobility of the partially exposed (unconstrained) bladder skin 10 and the elasticity of the elastic member used for sealing connection between the shock absorber 40 and the upper top seat to ensure that the shock absorber 40 can be twisted relative to the upper top seat fixed to the vehicle body within a certain range, that is, it can bend and deform to a certain extent. However, in the above technical solution, the protective tube 30 covers the bladder skin 10 on the inside, resulting in the originally movable bladder skin 10 being restricted by the protective tube 30, which will cause the shock absorber 40 to lose its torsion. To solve the above problem, the present application provides a bushing 60, which includes a flexible portion 61. The flexible portion 61 and the bushing 60 are both annular and are provided between the piston 50 and the outer cylinder of the shock absorber 40. When torsion occurs, the flexible portion 61 can undergo elastic deformation and work together with the elastic member for sealing connection between the shock absorber 40 and the upper top seat, so that the shock absorber 40 can undergo a certain torsion relative to the upper top seat. Therefore, as in the prior art, the wheel can undergo a certain torsion relative to the vehicle body. In addition, the bushing 60 is used to replace the original fixed sealing structure between the shock absorber 40 and the piston 50, so that the shock absorber 40 can undergo a certain torsion relative to the piston 50, so that the shock absorber 40 can still obtain the ability of torsion activity, and the setting of the bushing 60 simplifies the sealing structure of the lower end of the original inflation cavity 11, thereby simplifying the structure of the air spring and will not increase the radial volume of the air spring.

[0027] In the prior art, the outer cylinder of the shock absorber 40 is usually connected to the bottom of the piston 50 and sealed, so as to achieve the purpose of sealing the gas-filled cavity 11. However, in the present application, Figure 1 , Figure 2As shown, the inner annular surface is sealed and connected to the upper part of the outer peripheral surface of the outer cylinder of the shock absorber 40, and the outer annular surface is sealed and connected to the upper part of the inner peripheral surface of the piston 50. That is, the bushing 60 is sealed and arranged on the outer cylinder of the shock absorber 40 and the upper part of the piston 50. Since the original torsion dynamic relationship is changed in this application, there is no relative torsion or movement between the piston 50 and the shock absorber 40 in the prior art, but in this application, the shock absorber 40 and the piston 50 will be relatively torsion. If the bushing 60 is arranged on the outer cylinder of the shock absorber 40 and the lower part of the piston 50, at this time, the distance between the bushing 60 and the upper top seat is long. Even if a small angle torsion occurs, the middle part of the shock absorber 40 may actually move radially for a long distance, which may cause the shock absorber 40 to touch the piston 50. Therefore, the bushing 60 is arranged on the outer tube of the shock absorber 40 and the upper part of the piston 50 to shorten the distance between the bushing 60 and the upper top seat. When the same angle of torsion occurs, the deflection distance of the shock absorber 40 will be able to be reduced (similar to shortening the length of the lever and thus shortening the moving distance of its end in the lever principle). This can avoid excessive torsion of the shock absorber 40 and is more conducive to the stability of the overall structure of the air spring.

[0028] In addition, since the piston 50 is fixed to the outer tube of the shock absorber 40 and the upper part of the piston 50, the sealing component at the lower part of the piston 50 is eliminated, and the length of the piston 50 and the length of the dust cover 90 connected to the lower side of the protective tube 30 can be shortened, making the structure of the entire air spring more compact.

[0029] In order to fix the bushing 60 to the upper end of the outer tube of the shock absorber 40, as shown in FIG. Figure 1 As shown, since the bushing 60 also seals the bottom of the inflatable cavity 11, the pressure inside the inflatable cavity 11 will be greater than the external pressure. If the bushing 60 has no axial limit, especially when the bottom lacks axial limit, it will be displaced or even fall out due to the pressure inside the inflatable cavity 11 during long-term use. Figure 1 as well as Figure 2 As shown, the shock absorber 40 also includes a fixed sleeve 42, which includes a top support portion 421, an extension portion 422 and a supporting portion 423. The bottom surface of the support portion 421 is fitted on the top surface of the outer tube of the shock absorber 40, and the extension portion 422 extends downward from the edge of the support portion 421. The supporting portion 423 is annular, and the inner annular surface of the supporting portion 423 is connected to the outer side surface of the extension portion 422. The supporting portion 423 also includes a supporting surface arranged in the direction of the inflation cavity 11; the bushing 60 is fixed to the outer tube of the shock absorber 40 through the fixed sleeve 42, and the bottom surface of the bushing 60 is fitted with the supporting surface.

[0030] The bushing 60 is supported by the supporting portion 423, so as to achieve the purpose of fixing it to the upper part of the outer tube of the shock absorber 40. Since the top of the piston 50 is substantially the same height as the top of the outer tube of the shock absorber 40, the bushing 60 also corresponds to the upper position of the piston 50. In addition, with the help of the supporting portion 423, the bottom of the bushing 60 can be limited to prevent it from shifting under the pressure in the gas-filled cavity 11. The specific fixed position can be adjusted by adjusting the length of the extension portion 422. When the length of the extension portion 422 increases, the supporting portion 423 will be further away from the support portion 421, thereby further away from the top of the outer tube of the shock absorber 40, so as to achieve the purpose of adjusting the position of the bushing 60.

[0031] Since there is a spacing space between the piston 50 and the outer tube of the shock absorber 40, in order to fix the bushing 60, the spacing distance between the inner wall of the piston 50 and the outer tube of the shock absorber 40 can be set to be slightly smaller than the thickness of the bushing 60. When the bushing 60 is installed in the spacing space, a certain squeezing force will be generated on the flexible part 61 of the bushing 60. With the help of the reaction force generated by the flexible part 61, the bushing 60 can be fixed in the spacing space. However, since there is a certain pressure in the inflation cavity 11, in order to achieve better sealing performance, it is possible to further apply an external force to the flexible part 61. As a specific implementation method, Figure 2 As shown, the piston 50 also includes a lower pressing ring 80, which is sleeved on the outer side of the lower fixing portion 51. The lower pressing ring 80 can generate a clamping force toward the central axis of the lower pressing ring 80 and can fix the bottom end of the bladder skin 10 to the lower fixing portion 51.

[0032] In the prior art, the lower retaining ring 80 is usually used to fix the bottom end of the bladder skin 10. Through special equipment or tools, radial force is applied to it to cause a certain plastic deformation, thereby exerting a certain force on the bladder skin 10 and the lower fixing part 51 inside it.

[0033] Specifically, the lower pressing ring 80 can push the lower fixing portion 51 to press the bushing 60 .

[0034] In the present application, since a bushing 60 is provided, the bushing 60 can be provided correspondingly on the inner side of the lower fixing portion 51 to provide a certain radial support to the lower fixing portion 51. Therefore, compared with the prior art, it is possible to select a greater force to be applied to the lower pressing ring 80 to ensure the stability of the fixation of the bladder skin 10. At the same time, the force of the deformation of the lower pressing ring 80 can be used to further apply force to the bushing 60, thereby increasing the friction between the bushing 60 and the inner wall of the piston 50 to achieve a better sealing effect.

[0035] The bushing 60 may only include the flexible portion 61, and the side wall of the flexible portion 61 is directly attached to the outer cylinder of the shock absorber 40 and the side wall of the piston 50 to achieve a sealing effect. However, the flexible portion 61 itself is made of elastic material, so its strength is not high. Since the pressure in the inflation cavity 11 is always higher than the external pressure, the flexible portion 61 will be deformed. After a long period of use, it may be damaged and then fail. As a specific implementation method, Figure 1 , Figure 4 as well as Figure 5 As shown, the bushing 60 includes an outer ring portion 62 and an inner ring portion 63, the outer ring surface is arranged on the outer ring portion 62, and the inner ring surface is arranged on the inner ring surface, the outer ring portion 62 and the inner ring portion 63 are made of hard materials, the outer ring portion 62 is sleeved on the outer side of the flexible portion 61, and the inner ring portion 63 is arranged on the inner side of the flexible portion 61; wherein, the outer ring portion 62, the inner ring portion 63 and the flexible portion 61 are coaxially arranged and integrated.

[0036] The outer ring portion 62 and the inner ring portion 63 can be made of hard materials such as metal, nylon, etc., preferably metal materials such as steel. The hard outer ring portion 62 and the inner ring portion 63 can protect the flexible portion 61 clamped between the two to prevent excessive friction with the outer tube of the shock absorber 40 and the piston 50, thereby preventing damage.

[0037] Furthermore, since the outer ring portion 62 and the inner ring portion 63 are made of hard materials, they are in hard contact with the outer tube of the shock absorber 40 and the piston 50, and therefore, the sealing is insufficient. In order to solve the above problem, a structure or component for sealing can be provided, for example, Figure 4 , Figure 5 As shown, the outer ring surface is provided with an outer sealing groove 621, which is arranged circumferentially around the outer ring surface, and the opening of the outer sealing groove 621 faces the inner circumferential surface of the piston 50; the bushing 60 also includes an outer sealing ring 64, which matches the outer sealing groove 621, and the outer sealing ring 64 can partially protrude from the outer ring surface. Specifically, a plurality of outer sealing grooves 621 can be arranged at intervals along the axial direction, and the specific number can be selected according to actual conditions. In the case shown in the figure, two are arranged.

[0038] Similar to the outer ring, Figure 4 as well as Figure 5 As shown, the inner ring surface is provided with an inner sealing groove 631, which is arranged along the circumference of the inner ring surface, and the opening of the inner sealing groove 631 faces the inner circumference of the piston 50. The bushing 60 also includes an inner sealing ring 65, which matches the inner sealing groove 631 and can partially protrude from the inner ring surface. The outer sealing ring 64 and the inner sealing ring 65 are directly in contact with the sealing surface to be sealed, so as to achieve a better sealing effect and purpose.

[0039] As an implementation method, Figure 3 As shown, a buckling portion 31 is provided on the upper portion of the protective tube 30 , and the buckling portion 31 can be attached to the top end of the bladder skin 10 under the action of external force, and apply a buckling pressure toward the central axis to the top end of the bladder skin 10 .

[0040] In the prior art, the bladder skin 10 is fixed by directly pressing the bladder skin 10 through a pressing ring, and the protective tube 30 does not extend to the top position of the bladder skin 10. In the present application, since the structure of the protective tube 30 is changed, in order to fix the protective tube 30, the pressing portion 31 of the protective tube 30 can be pressed to the top position of the bladder skin 10 by squeezing the pressing portion 31 or by interference fit. While achieving the fixing purpose, the bladder skin 10 can also be directly fixed, thereby eliminating the need for the pressing ring and simplifying the number of assembly parts and the process.

[0041] Since the casing 30 is usually made of aluminum and is a thin-walled part, if the bladder skin 10 is sealed and fixed only by the buckling portion 31, there may be problems such as insufficient force and easy damage. Therefore, the casing 30 also includes an upper buckling ring, which is sleeved on the outer side of the upper part of the casing 30. The upper buckling ring can squeeze the buckling portion 31 and the top of the bladder skin 10 and be fixed to the upper fixing portion 21. The upper buckling ring can adopt a structure similar to that in the prior art, and the upper buckling ring is squeezed by a special tool or equipment to deform it, and the buckling portion 31 and the top of the bladder skin 10 are squeezed at the same time to achieve a further fixing purpose.

[0042] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in actual applications, various changes may be made thereto in form and detail without departing from the scope of the present disclosure.

Claims

1. A compact air spring, characterized in that: The compact air spring comprises: The bladder skin is made of elastic material, is annular and has an inflatable cavity inside; An upper top seat, wherein the upper top seat is provided with an upper fixing portion, and the top end of the bag skin can be sealed and mounted on the upper fixing portion; A protective tube, wherein the protective tube is sleeved on the outer side of the bladder skin, the upper end of the protective tube is connected to the top end of the bladder skin and fixed to the upper fixing portion, and the inner wall of the protective tube is directly attached to the bladder skin and limits the expansion of the bladder skin in the radial direction; A piston, the piston is arranged at the lower side of the inflation cavity, the top of the piston is provided with a lower fixing part for fixing the bottom end of the bladder skin, and the bottom end of the bladder skin is sealed and connected to the lower fixing part; A shock absorber, the shock absorber passes through the inflatable cavity and is connected to the upper seat through an elastic seal, the shock absorber comprises a shock absorber outer cylinder, the piston is coaxially arranged with the shock absorber outer cylinder, and a spacing space is provided between the inner circumference of the piston and the outer circumference of the shock absorber outer cylinder; A bushing, wherein the bushing is annular, the inner ring surface of the bushing is sealingly connected to the outer peripheral surface of the shock absorber outer cylinder, and the outer ring surface of the bushing is in contact with the inner peripheral surface of the piston, so that the bushing can partially fill the interval space in the axial direction; the bushing is provided with a flexible portion coaxially arranged with the bushing and in an annular shape; The inner annular surface is sealed and connected to the upper portion of the outer peripheral surface of the shock absorber outer tube, and the outer annular surface is sealed and connected to the upper portion of the inner peripheral surface of the piston; The shock absorber further comprises a fixing sleeve, the fixing sleeve comprises a top supporting portion, an extending portion and a supporting portion, the bottom surface of the supporting portion is arranged in close contact with the top surface of the shock absorber outer tube, the extending portion extends downward from the edge of the supporting portion, the supporting portion is annular, the inner annular surface of the supporting portion is connected to the outer side surface of the extending portion, and the supporting portion further comprises a supporting surface arranged in the direction of the inflation cavity; The bushing is fixed on the outer cylinder of the shock absorber through the fixing sleeve, and the bottom surface of the bushing is arranged in contact with the supporting surface.

2. A compact air spring according to claim 1, characterized in that: The piston also includes a lower pressing ring, which is sleeved on the outer side of the lower fixing portion. The lower pressing ring can generate a pressing force toward the central axis of the lower pressing ring and can fix the bottom end of the bladder skin to the lower fixing portion.

3. A compact air spring according to claim 2, characterized in that: The lower pressing ring can push the lower fixing portion to squeeze the bushing.

4. A compact air spring according to claim 1, characterized in that: The bushing includes an outer ring portion and an inner ring portion, the outer ring surface is arranged on the outer ring portion, the inner ring surface is arranged on the inner ring surface, the outer ring portion and the inner ring portion are made of hard materials, the outer ring portion is sleeved on the outer side of the flexible portion, and the inner ring portion is arranged on the inner side of the flexible portion; The outer ring portion, the inner ring portion and the flexible portion are coaxially and integrally arranged.

5. A compact air spring according to claim 4, characterized in that: The outer ring surface is provided with an outer sealing groove, the outer sealing groove is circumferentially arranged around the outer ring surface, and the opening of the outer sealing groove faces the inner circumferential surface of the piston; The bushing also includes an outer sealing ring, which matches the outer sealing groove and can partially protrude from the outer annular surface.

6. A compact air spring according to claim 4, characterized in that: The inner ring surface is provided with an inner sealing groove, which is arranged along the circumference of the inner ring surface, and the opening of the inner sealing groove faces the inner circumferential surface of the piston. The bushing also includes an inner sealing ring, which matches the inner sealing groove and can partially protrude from the inner ring surface.

7. A compact air spring according to claim 1, characterized in that: The upper part of the protective tube is provided with a buckling part, and the buckling part can be attached to the top end of the bladder skin under the action of external force, and exert a buckling pressure toward the central axis on the top end of the bladder skin.

8. A compact air spring according to claim 7, characterized in that: The protective tube also includes an upper buckling ring, which is sleeved on the outer side of the upper part of the protective tube. The upper buckling ring can squeeze the buckling part and the top end of the bladder skin and be fixed to the upper fixing part.

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