Piston rotation stopping structure, piston and air spring

Abstract

The invention provides a piston rotation stopping structure, a piston and an air spring. The piston comprises a body part and a matching part which are connected. The rotation stopping structure comprises a first connecting structure and a second connecting structure; the first connecting structure is arranged at the first end, connected with the matching part, of the body part; the second connecting structure is arranged at the second end, connected with the body part, of the matching part; the first connecting structure and the second connecting structure are matched with each other so that the body part and the matching part can be connected in the circumferential direction in a rotation stopping mode, and the technical problem that relative rotation is prone to occurring at the connecting positions of all assemblies of the split type piston can be solved.

Description

Technical Field

[0001] This invention relates to the field of vehicle suspension technology, and in particular to a piston anti-rotation structure, a piston, and an air spring. Background Technology

[0002] In an air spring system, the piston, as the core component, is typically cylindrical and installed inside the spring. Its up-and-down movement adjusts the internal air pressure, achieving shock absorption and cushioning during vehicle operation. When the vehicle encounters an impact from an uneven road surface, the suspension system transmits the vibration to the air spring. The air spring reciprocates under air pressure, compressing or expanding the air to effectively absorb energy and reduce vehicle vibration, ensuring a smooth ride.

[0003] In the field of air springs, split piston structures have been used to meet different design requirements. However, after such split structures are connected, the components are prone to relative rotation under circumferential torque, which directly affects the sealing reliability and shock absorption stability of the air spring. Summary of the Invention

[0004] This invention provides a piston anti-rotation structure, a piston, and an air spring to improve the technical problem of relative rotation easily occurring at the connection points of the components of a split piston.

[0005] The present invention provides a piston anti-rotation structure, wherein the piston includes a connected body portion and a mating portion; the anti-rotation structure includes a first connecting structure and a second connecting structure; the first connecting structure is disposed at a first end where the body portion and the mating portion are connected; the second connecting structure is disposed at a second end where the mating portion and the body portion are connected; the first connecting structure and the second connecting structure cooperate with each other to realize an anti-rotation connection between the body portion and the mating portion in the circumferential direction.

[0006] In one embodiment of the anti-rotation structure of the present invention, the anti-rotation structure includes mutually cooperating grooves and protrusions; wherein, the first connecting structure includes grooves and / or protrusions, and the second connecting structure includes protrusions and / or grooves.

[0007] In one embodiment of the anti-rotation structure of the present invention, the protrusion and the groove that cooperate with each other are in an interference fit.

[0008] In one embodiment of the anti-rotation structure of the present invention, a limiting groove is provided on the side wall of the groove, and a limiting block is provided on the corresponding side of the protrusion. The limiting block cooperates with the limiting groove to lock the body part and the mating part along the axial direction.

[0009] In one embodiment of the anti-rotation structure of the present invention, both the main body and the mating part are cylindrical structures. The main body includes a surrounding first wall, and the mating part includes a surrounding second wall. The first connecting structure consists of a plurality of first grooves and / or a plurality of first protrusions formed at the first end of the first wall. Along the axial direction of the main body, the first grooves are recessed at the first end, and the first protrusions protrude from the first end. The second connecting structure consists of a plurality of second protrusions and / or a plurality of second grooves formed at the second end of the second wall. Along the axial direction of the mating part, the second protrusions protrude from the second end, and the second grooves are recessed at the second end. The first protrusions mate with the second grooves, and / or the second protrusions mate with the first grooves, so that the main body and the mating part are connected in an anti-rotational manner.

[0010] In one embodiment of the anti-rotation structure of the present invention, when the first connecting structure is a first groove and the second connecting structure is a second protrusion, the first groove does not penetrate the first wall along the radial direction of the main body; or, when the first connecting structure is a first protrusion and the second connecting structure is a second groove, the second groove does not penetrate the second wall along the radial direction of the mating part.

[0011] The present invention also provides a piston comprising a body portion and a mating portion, wherein the body portion and the mating portion are connected by an anti-rotation structure as described in any of the preceding claims.

[0012] In one embodiment of the piston of the present invention, the body portion is made of plastic and the mating portion is made of metal.

[0013] In one embodiment of the piston of the present invention, the mating part is integrated with the body part by an insert injection molding process.

[0014] The present invention also provides an air spring, including an air bladder and a positioning ring, and further including a piston of any of the above. The piston includes a connected body portion and a mating portion, wherein the end of the body portion away from the mating portion is sealed to the air bladder, and the end of the mating portion away from the body portion is interference-fitted with the positioning ring.

[0015] The beneficial effects of the present invention are as follows: The piston anti-rotation structure, piston and air spring proposed in this invention achieve circumferential anti-rotation function by setting a first connecting structure and a second connecting structure that cooperate with each other at the connection end of the main body and the mating part, which improves the problem that relative rotation is easy to occur at the connection between the main body and the mating part, and has the advantages of ensuring the sealing reliability and shock absorption stability of the air spring. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram:

[0018] Figure 1 This is a partial structural schematic diagram of an air spring provided in an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the piston structure provided in one embodiment of the present invention;

[0020] Figure 3 This is an exploded view of a piston provided in one embodiment of the present invention;

[0021] Figure 4 This is an exploded front view of a piston provided in one embodiment of the present invention;

[0022] Figure 5 for Figure 4 A magnified view of a section at point A in the middle;

[0023] Figure 6 This is an exploded view of a piston provided in one embodiment of the present invention;

[0024] Figure 7 This is an exploded view of a piston provided in one embodiment of the present invention;

[0025] Figure 8 This is an exploded front view of a piston provided in one embodiment of the present invention.

[0026] The attached figures are labeled as follows:

[0027] 1. Air spring; 10. Piston; 11. Positioning ring; 100. Body part; 110. First end; 120. First wall; 200. Mating part; 210. Second end; 220. Second wall; 300. Anti-rotation structure; 310. First connecting structure; 320. Second connecting structure; 330. Groove; 331. First groove; 332. Second groove; 333. Limiting groove; 340. Protrusion; 341. First protrusion; 342. Second protrusion; 343. Limiting block. Detailed Implementation

[0028] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0029] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0030] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0031] As automotive design demands for lightweighting and cost control increase, the problem of increased weight and processing costs due to increased wall thickness in traditional metal pistons has become increasingly prominent, prompting the industry to shift towards plastic piston solutions to reduce overall weight and manufacturing costs.

[0032] However, the inherent weakness of plastic materials poses significant challenges in practical applications: during installation, to meet anti-rotation requirements, the piston and locating ring must be connected with an interference fit. However, plastic pistons are prone to local deformation under interference fit, leading to a significant reduction in structural strength and a deterioration in sealing performance. After long-term use, the strength of the deformed area continues to decrease, making it unable to effectively resist torsional forces, causing relative rotation between the piston and locating ring.

[0033] In view of this, this application provides a piston 10, please refer to... Figure 1 and Figure 2 The piston 10 includes a connected body portion 100 and a mating portion 200. The body portion 100 is made of plastic to reduce overall weight and control costs, while the mating portion 200 is made of high-strength metal to bear the main mechanical load and is used to connect with the positioning ring 11 via an interference fit. This design transfers the key stress of the anti-rotation function to the metal mating portion 200, so that the plastic body portion 100 only bears a small fitting stress, effectively preventing local deformation caused by insufficient material strength, while maintaining the structural integrity and sealing performance of the piston 10.

[0034] Considering that the body part 100 and the mating part 200 are usually fixedly connected by an interference fit, and that the piston 10 is prone to relative rotation at the connection point during long-term use, the risk of air leakage increases and the energy absorption efficiency during the shock absorption process decreases.

[0035] Please see Figures 2 to 8 This application provides a piston 10 anti-rotation structure 300, in which the main body 100 and the mating part 200 are connected and fixed by the anti-rotation structure 300. The anti-rotation structure 300 realizes the circumferential anti-rotation function, improves the relative rotation problem caused by deformation when the main body 100 and the mating part 200 are conventionally interference fit, and has the advantages of ensuring the sealing reliability and shock absorption stability of the air spring 1.

[0036] Please see Figure 2 and Figure 3 The present invention provides a piston 10 anti-rotation structure 300, comprising a first connecting structure 310 and a second connecting structure 320. The first connecting structure 310 is disposed at a first end 110 where the body portion 100 connects to the mating portion 200. The second connecting structure 320 is disposed at a second end 210 where the mating portion 200 connects to the body portion 100. The first connecting structure 310 and the second connecting structure 320 cooperate to form a circumferential mechanical lock, thereby preventing relative rotation between the body portion 100 and the mating portion 200 during installation or operation. This achieves a circumferentially anti-rotational connection between the body portion 100 and the mating portion 200.

[0037] Please see Figure 3 The first connecting structure 310 refers to a structure disposed at the first end 110 where the body part 100 connects to the mating part 200, used to achieve circumferential anti-rotation. It can be implemented by means of keyways, pin holes, or polygonal mating, for example, by machining a flat keyway, providing a cylindrical pin hole, or forming a hexagonal cross-section at the end of the body part 100. Its main purpose is to provide circumferential fixation between the body part 100 and the mating part 200. Further, the second connecting structure 320 refers to a corresponding structure disposed at the second end 210 where the mating part 200 connects to the body part 100. It can be implemented by means of keys, pins, or polygonal bosses, for example, flat keys, cylindrical pins, or polygonal bosses. Its main purpose is to cooperate with the first connecting structure 310 to prevent relative rotation. Therefore, this application designs the piston 10 as a combination structure of the body part 100 and the mating part 200, and sets a mutually cooperating anti-rotation structure 300 at the connection end, thereby realizing the anti-rotation connection between the body part 100 and the mating part 200 in the circumferential direction, thus solving the technical problem that the anti-rotation function fails due to deformation caused by insufficient material strength when the plastic piston 10 is installed with an interference fit.

[0038] Specifically, this design allows the body 100 to use lightweight materials to reduce overall weight, while the mating part 200 bears the main load, preventing permanent deformation of the plastic parts due to stress concentration during mating, thereby maintaining structural strength and sealing performance. As a preferred embodiment, the anti-rotation structure 300 achieves circumferential anti-rotation based on a mechanical locking principle, without relying on interference fits that cause large material deformation, thus ensuring the long-term reliability of the anti-rotation function.

[0039] Please see Figures 3 to 8 In one embodiment of the anti-rotation structure 300 of the present invention, the anti-rotation structure 300 includes a mutually cooperating groove 330 and a protrusion 340. The mutually cooperating groove 330 and protrusion 340 refer to a mechanical interlocking structure for circumferential anti-rotation, which can be implemented using geometric shapes such as rectangles, trapezoids, or arcs. Its purpose is to provide a reliable anti-rotation function through shape matching, avoiding plastic deformation of the plastic material caused by interference fit. Specifically, the first connecting structure 310 includes a groove 330 and / or a protrusion 340, and the second connecting structure 320 includes a protrusion 340 and / or a groove 330. It should be noted that the groove 330 on the first connecting structure 310 cooperates with the protrusion 340 on the second connecting structure 320, and vice versa.

[0040] Please see Figures 3 to 8 Specifically, as one implementation, the first connecting structure 310 can be specifically formed as a plurality of grooves 330 on the first end 110 of the body portion 100, and the second connecting structure 320 can be specifically formed as a plurality of protrusions 340 on the second end 210 of the mating portion 200. The grooves 330 and the protrusions 340 fit together after axial docking, achieving circumferential constraint through geometric matching. The grooves 330 are recessed into the surface of the first end 110 along the axial direction of the body portion 100, and the protrusions 340 protrude from the surface of the second end 210 along the axial direction of the mating portion 200. During the mating process, the two can achieve anti-rotation locking without relying on interference stress, thereby eliminating the risk of plastic deformation of the plastic material under interference fit and ensuring the long-term stability of the anti-rotation function. This approach retains the lightweight advantage of the plastic body portion 100 while the metal mating portion 200 provides reliable torsional resistance, avoiding a decrease in sealing performance, ultimately achieving a balance between weight reduction, cost reduction, and functional reliability for the air spring 1 piston 10.

[0041] In some embodiments of this application, the groove 330 and the protrusion 340 are proposed to achieve an anti-rotation connection between the body part 100 and the mating part 200. However, in the implementation process, the lack of clear specification of the mating type may lead to insufficient anti-rotation effect or deformation of the plastic piston 10 due to interference fit, affecting structural strength and sealing performance.

[0042] In this regard, please refer to one embodiment of the anti-rotation structure 300 of the present invention. Figure 3 and Figure 8 The protrusion 340 and the groove 330 are in an interference fit. An interference fit refers to a dimensional difference between the protrusion 340 and the groove 330 during assembly, where the outer diameter of the protrusion 340 is slightly larger than the inner diameter of the groove 330. This generates radial compressive stress during assembly, which can be achieved by controlling dimensional tolerances through precision machining or by using thermal assembly processes. The solution in this application sets the interlocking protrusion 340 and groove 330 in an interference fit, forcing a tight compression during assembly. This significantly increases the normal pressure on the contact surface, thereby improving friction and effectively preventing relative rotation between the body 100 and the mating part 200 in the circumferential direction.

[0043] Please see Figure 3 and Figure 8 Specifically, in one of the above embodiments, the first connecting structure 310 can be specifically formed as a plurality of grooves 330 on the first end 110 of the body portion 100, and the second connecting structure 320 can be specifically formed as a plurality of protrusions 340 on the second end 210 of the mating portion 200. The outer diameter of the protrusions 340 can be designed to be slightly larger than the inner diameter of the first groove 331. During assembly, the two are tightly joined by a pressing process to achieve an interference fit. Considering the material characteristics of the body portion 100 being made of plastic and the mating portion 200 being made of metal, the stress generated by the interference fit is mainly borne by the high-strength metal mating portion 200. This solution avoids structural damage to the plastic body portion 100 due to stress concentration, thus maintaining the advantage of lightweight design while ensuring sealing performance during long-term use.

[0044] Considering that the main body 100 and the mating part 200 lack an axial restraint mechanism, the main body 100 and the mating part 200 may move axially relative to each other, resulting in a decrease in sealing performance, loosening of connection or weakening of anti-rotation effect. In particular, when the plastic piston 10 is deformed due to interference fit, axial movement will further aggravate the degree of deformation, affecting the stability and reliability of the product in long-term use.

[0045] Please see Figure 4 and Figure 5In one embodiment of the anti-rotation structure 300 of the present invention, a limiting groove 333 is formed on the side wall of the groove 330, and a limiting block 343 is provided on the corresponding side of the protrusion 340. The limiting block 343 cooperates with the limiting groove 333 to lock the axial movement of the body part 100 and the mating part 200. The limiting groove 333 refers to a groove structure formed on the side wall of the groove 330 for axial positioning. It can be implemented in the shape of a rectangular groove, trapezoidal groove, or dovetail groove, etc., and its purpose is to provide an axial locking point to prevent relative movement between the body part 100 and the mating part 200. The limiting block 343 refers to a protrusion 340 structure provided on the corresponding side of the protrusion 340 that cooperates with the limiting groove 333. It can be implemented in the shape of a rectangular protrusion, trapezoidal protrusion, or spherical protrusion, etc., and its purpose is to be embedded in the limiting groove 333 to form a mechanical lock, thereby achieving axial constraint.

[0046] Specifically, please refer to Figure 2 The solution of this application uses the limiting groove 333 on the side wall of the groove 330 and the limiting block 343 on the corresponding side of the protrusion 340 to cooperate with each other. During the connection between the main body 100 and the mating part 200, when the protrusion 340 and the groove 330 are engaged in circumferential anti-rotation, the limiting block 343 is naturally embedded in the limiting groove 333, forming a direct mechanical fit, thereby providing rigid constraint in the axial direction, preventing axial displacement caused by vibration or pressure changes, and further ensuring the stability and sealing performance of the anti-rotation connection.

[0047] Please see Figure 2 In one embodiment of the anti-rotation structure 300 of the present invention, both the main body 100 and the mating part 200 are cylindrical structures. This can be understood as having a hollow cylindrical or hollow prismatic geometric shape, which can be achieved by integral molding or modular assembly. This configuration optimizes the stress distribution path, allowing the connecting area to uniformly distribute the load when subjected to force. The main body 100 includes a surrounding first wall 120, and the mating part 200 includes a surrounding second wall 220. The surrounding first wall 120 and surrounding second wall 220 refer to continuous annular walls, which can be implemented using a uniform thickness or locally reinforced design; there is no limitation on this.

[0048] Please see Figure 3 , Figure 4 and Figure 8The first connecting structure 310 consists of a plurality of first grooves 331 and / or a plurality of first protrusions 341 formed on the first end 110 of the first wall 120. Along the axial direction of the body portion 100, the first grooves 331 are recessed into the first end 110, and the first protrusions 341 protrude from the first end 110. The plurality of first grooves 331 and / or the plurality of first protrusions 341 can be implemented using three, four, or more sets of grooves 330 and / or protrusions 340 to disperse the anti-rotation force and avoid damage to the plastic material from single-point overload.

[0049] Please see Figure 3 , Figure 4 and Figure 8 The second connecting structure 320 consists of a plurality of second protrusions 342 and / or a plurality of second grooves 332 formed on the second end 210 of the second wall 220. Along the axial direction of the mating portion 200, the second protrusions 342 protrude from the second end 210, and the second grooves 332 are recessed into the second end 210. The second connecting structure 320 consisting of a plurality of second protrusions 342 and / or a plurality of second grooves 332 can be understood as corresponding features provided on the second end 210 of the second wall 220. It can be implemented using a geometry complementary to the first connecting structure 310 to ensure the balance of the connection and prevent loosening of the connection due to eccentric force.

[0050] Please see Figure 3 , Figure 4 and Figure 8 In this configuration, the first protrusion 341 engages with the second groove 332, and / or the second protrusion 342 engages with the first groove 331. When the body portion 100 is connected to the mating portion 200, the first groove 331 and the second protrusion 342, and / or the first protrusion 341 and the second groove 332, fit together to form a mechanical interlock, thereby preventing relative rotation in the circumferential direction and ensuring a non-rotating connection between the body portion 100 and the mating portion 200. This application reduces the local deformation of the body portion 100 of the piston 10 during the non-rotating connection, maintains the overall strength and sealing performance of the piston 10, and ensures the reliable realization of the non-rotating function.

[0051] Please see Figure 4 and Figure 8In one embodiment of the anti-rotation structure 300 of the present invention, the first connecting structure 310 is a first groove 331 and the second connecting structure 320 is a second protrusion 342. Along the radial direction of the body portion 100, the first groove 331 does not penetrate the first wall 120. That is, the depth of the first groove 331 along the radial direction of the body portion 100 is less than the thickness of the first wall 120. It can be understood that a residual wall is formed at the location where the first groove 331 is provided on the first wall 120. The retained residual wall allows the first wall 120 to retain a complete circumferential profile at least on its inner or outer side. On the one hand, the complete circumferential profile can prevent external water vapor, dust, and other contaminants from entering radially from the connection interface of the first groove 331 and the second protrusion 342, thereby improving the sealing performance of the piston 10. On the other hand, the complete circumferential profile maintains the continuity and load-bearing capacity of the first connecting structure 310, and also ensures the geometric shape and dimensional stability of the interference fit surface. This further improves the service life of the piston 10.

[0052] Specifically, in one embodiment, such as Figure 6 As shown, the aforementioned residual wall is located on the radial outer side of the first wall 120, that is, the radial outer side of the first wall 120 has a complete circumferential contour. This arrangement makes the piston 10 have a relatively flat and smooth outer surface, which is beneficial for the airbag to roll along the piston 10, optimizes the deformation contour of the airbag, reduces stress concentration, and thus delays the fatigue aging of the airbag.

[0053] In another embodiment, such as Figure 3 and Figure 4 As shown, the aforementioned residual wall is located radially inside the first wall 120, that is, the second protrusion 342 of the second connecting structure 320 is located outside the first sidewall. Since the second wall 220 is interference-fitted with the positioning member, radial deformation will still occur during long-term use. This arrangement can provide space for radial deformation of the second wall 220 to avoid damaging the first wall 120, thereby improving the service life of the piston 10.

[0054] Please see Figure 8 In one embodiment of the anti-rotation structure 300 of the present invention, when the first connecting structure 310 is a first protrusion 341 and the second connecting structure 320 is a second groove 332, the second groove 332 does not penetrate the second wall 220 along the radial direction of the mating portion 200. This arrangement, as described in the above embodiments, can also improve the sealing performance of the piston 10, maintain the continuity and load-bearing capacity of the second connecting structure 320, and also ensure the geometric and dimensional stability of the interference fit surface, thereby improving the service life of the piston 10.

[0055] Please see Figure 7When the first wall 120 or the second wall 220 does not retain a complete circumferential profile, the groove 330 can also be set as a through groove that penetrates the first wall 120 or the second wall 220. This structural setting is conducive to reducing the processing difficulty of the groove 330, and also conducive to reducing the assembly accuracy of the groove 330 and the protrusion 340, thereby reducing production costs.

[0056] Please see Figure 3 and Figure 7 The present invention also provides a piston 10, which includes a body portion 100 and a mating portion 200. The body portion 100 is made of plastic, such as engineering plastics like polyamide, polyoxymethylene, or polypropylene, and is not limited thereto. Using plastic material for the body portion 100 can reduce the overall weight and control costs. The mating portion 200 is made of metal, including but not limited to aluminum alloy, stainless steel, or carbon steel. The metal mating portion 200, made of high-strength metal material, can bear the main mechanical load. The mating portion 200 is used to connect with the positioning ring 11 through an interference fit, thereby improving the structural strength at the connection between the piston 10 and the positioning ring 11. This alleviates the problem that the all-plastic piston 10 is prone to local deformation due to insufficient strength, which can lead to torsion and interference fit failure.

[0057] Please see Figure 3 and Figure 7 Furthermore, the main body 100 and the mating part 200 are connected by the anti-rotation structure 300 described in any of the above-mentioned embodiments. The anti-rotation structure 300 realizes the circumferential anti-rotation function of the main body 100 and the mating part 200, improves the relative rotation problem caused by deformation when the main body 100 and the mating part 200 are conventionally interference-fitted, and has the advantages of ensuring the sealing reliability and shock absorption stability of the air spring 1.

[0058] Please see Figure 3 and Figure 7 In one embodiment of the piston 10 of the present invention, the mating part 200 is integrally formed with the body part 100 through an insert injection molding process. The insert injection molding process can be understood as a manufacturing method in which a pre-prepared metal insert is placed into an injection mold, followed by the injection of molten plastic, allowing the plastic to solidify after cooling and forming an integrated structure with the metal insert. This process can be implemented using thermoplastic injection molding or thermosetting plastic injection molding, etc. Using this process can mitigate the deformation of the body part 100 caused by radial pressure due to interference fit during subsequent assembly stages, thereby ensuring the geometric integrity and material strength of the body part 100. Furthermore, it helps maintain a state of no relative displacement between the body part 100 and the mating part 200, ensuring the reliability of the anti-rotation function and the stability of the sealing interface.

[0059] Please see Figure 1The present invention also provides an air spring 1, including an air bladder and a positioning ring 11, and further including a piston 10 as described above. The piston 10 includes a body portion 100 and a mating portion 200 connected by an anti-rotation structure 300. The end of the body portion 100 away from the mating portion 200 is sealed to the air bladder, and the end of the mating portion 200 away from the body portion 100 is press-fitted to the positioning ring 11. Since the body portion 100 of the piston 10 is made of plastic, the lightweight requirement of the air spring 1 is achieved. The mating portion 200, which press-fits with the positioning ring 11, is made of metal, and the mating portion 200 is firmly connected to the body portion 100 through the anti-rotation structure 300, ensuring extremely high structural strength and torsional resistance at the connection with the positioning ring 11, fundamentally solving the problem of easy deformation and damage due to insufficient strength of the all-plastic piston 10. It should be noted that the other mechanisms of this air spring 1 are readily available to those skilled in the art and will not be described in detail here.

[0060] The present invention proposes a piston anti-rotation structure, a piston and an air spring. By setting a first connecting structure and a second connecting structure that cooperate with each other at the connection end of the main body and the mating part, the circumferential anti-rotation function is achieved. This avoids the relative rotation problem caused by deformation when the main body and the mating part are conventionally interference-fitted, and has the advantages of ensuring the sealing reliability and shock absorption stability of the air spring.

[0061] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A piston anti-rotation structure characterized by, The piston comprises a connected body part and a matching part; the rotation-stopping structure comprises: a first connecting structure arranged at a first end where the body part and the matching part are connected; a second connecting structure arranged at a second end where the matching part and the body part are connected; wherein the first connecting structure and the second connecting structure cooperate with each other to achieve the circumferential rotation-stopping connection of the body part and the matching part.

2. The anti-rotation structure according to claim 1, characterized by The rotation-stopping structure comprises recesses and protrusions that cooperate with each other; wherein the first connecting structure comprises recesses and / or protrusions, and the second connecting structure comprises protrusions and / or recesses.

3. The anti-rotation structure according to claim 2, characterized in that The protrusions and the recesses that cooperate with each other are in interference fit.

4. The anti-rotation structure according to claim 2, characterized by The side wall of the recess is provided with a limiting groove, and the corresponding side of the protrusion is provided with a limiting block, which cooperates with the limiting groove to lock the axial movement of the body part and the matching part.

5. The anti-rotation structure according to claim 2, wherein The body part and the matching part are both cylindrical structures, the body part comprises a surrounding first wall body, and the matching part comprises a surrounding second wall body; The first connecting structure is a plurality of first recesses and / or a plurality of first protrusions formed at the first end of the first wall body, along the axial direction of the body part, the first recesses are recessed at the first end, and the first protrusions are protruded at the first end; The second connecting structure is a plurality of second protrusions and / or a plurality of second recesses formed at the second end of the second wall body, along the axial direction of the matching part, the second protrusions are protruded at the second end, and the second recesses are recessed at the second end; wherein the first protrusions cooperate with the second recesses, and / or the second protrusions cooperate with the first recesses, to achieve the rotation-stopping connection of the body part and the matching part.

6. The anti-rotation structure according to claim 5, characterized by When the first connecting structure is a first recess and the second connecting structure is a second protrusion, along the radial direction of the body part, the first recess does not penetrate the first wall body; or, When the first connecting structure is a first protrusion and the second connecting structure is a second recess, along the radial direction of the matching part, the second recess does not penetrate the second wall body.

7. A piston characterized by, The body part and the matching part are connected by the rotation-stopping structure according to any one of claims 1 to 8.

8. The piston of claim 7 wherein, The body part is made of plastic, and the matching part is made of metal.

9. The piston of claim 8 wherein, The matching part is integrated with the body part through an insert injection molding process.

10. An air spring comprising a bellows and a positioning ring, characterized in that, The piston according to any one of claims 7 to 9 comprises a connected body part and a matching part, one end of the body part away from the matching part is sealingly connected with the air bag, and one end of the matching part away from the body part is in interference fit with the positioning ring.

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