Anti-cracking rubber bushing and preparation method thereof

Abstract

The invention relates to an anti-cracking rubber bushing and a preparation method thereof. The anti-cracking rubber bushing comprises a first bushing and a second bushing, the second sleeve is coaxially arranged in the first sleeve; the composite elastomer group is arranged between the first sleeve and the second sleeve, extends in the axial direction of the second sleeve and comprises a plurality of composite elastomers distributed in the circumferential direction, a cavity is formed between every two adjacent composite elastomers, and each composite elastomer comprises an elastic base body and a plurality of elastic bodies, the reinforcing rib net is wound outside the elastic base body in a prestress state; and the bonding layer is arranged between the elastic base body and the first sleeve and between the elastic base body and the second sleeve. A reinforcing rib net is wound on the surface of an elastic base body through preset tension, a continuous pre-compression stress field is applied to the elastic base body, when tensile stress generated by an external load acts on an elastic body, the pre-compression stress needs to be counteracted firstly, so that the net tensile stress actually borne by the elastic body is greatly reduced, and the elastic body is prevented from being damaged. Therefore, the cracking threshold is obviously improved.

Description

Technical Field

[0001] This application relates to the field of rubber bushing technology, and in particular to a crack-resistant rubber bushing and its preparation method. Background Technology

[0002] Rubber bushings, as a critical elastic connecting element, are widely used in automotive suspension systems, powertrain mounts, and various industrial vibration damping structures. Under actual operating conditions, rubber bushings need to withstand complex multi-directional loads, including axial force, radial force, torsional moment, and their combined effects. Especially under high loads or high-frequency reciprocating motion conditions, stress concentration easily occurs within the rubber elastomer. After long-term service, these stress concentration areas can trigger the initiation and propagation of microcracks, ultimately leading to fatigue failure phenomena such as cracking of the rubber bushing and debonding of the rubber from the sleeve. Once the bushing fails, it will directly affect the vehicle's handling stability, ride comfort, and even pose safety risks.

[0003] To address these issues, existing technologies typically improve the tear strength of rubber materials by optimizing their formulation. This can be achieved by adding reinforcing fillers, antioxidants, or employing novel raw rubber systems to enhance the tear strength and fatigue resistance of the rubber matrix. However, simple material modification has inherent limitations and is insufficient to suppress crack formation. Summary of the Invention

[0004] This application provides a crack-resistant rubber bushing and its preparation method to address the inherent limitations of simple material modification in related technologies, which makes it difficult to suppress the generation of cracks in rubber bushings.

[0005] In a first aspect, a crack-resistant rubber bushing is provided, comprising: First casing; The second sleeve is coaxially disposed inside the first sleeve; A composite elastomer assembly is disposed between a first sleeve and a second sleeve, and extends axially along the first sleeve. It includes multiple composite elastomers distributed circumferentially along the second sleeve, with cavities between adjacent composite elastomers. Each composite elastomer includes: - Elastic matrix; -A reinforcing mesh, prestressed and wound around the elastic matrix; - An adhesive layer is placed outside the reinforcing mesh and disposed between the elastic substrate and the first sleeve, and between the elastic substrate and the second sleeve.

[0006] In some embodiments, the reinforcing mesh includes: A plurality of first stirrups are arranged around the outside of the elastic matrix, spaced apart and parallel to each other along the axial direction of the elastic matrix.

[0007] In some embodiments, the reinforcing mesh further includes: A plurality of second stirrups are provided at intervals around the outside of the elastic matrix; The plane containing the first stirrup is perpendicular to the plane containing the second stirrup.

[0008] In some embodiments, the two ends of the second sleeve extend axially 3-10 mm beyond the ends of the composite elastomer assembly.

[0009] In some embodiments, a limiting rib is provided in the cavity. The limiting rib is connected to the inner wall of the first sleeve and extends along the axial direction of the first sleeve, and protrudes toward the outer wall of the second sleeve.

[0010] In some embodiments, the cross-section of the limiting rib is trapezoidal or semi-circular, and there is a gap between its top end and the outer wall of the second sleeve. The size of the gap is smaller than the radial compression of the composite elastomer under the maximum design load.

[0011] In some embodiments, the adhesive layer is a vulcanized adhesive layer.

[0012] In some embodiments, the reinforcing mesh is a mixed fiber bundle of aramid fibers and carbon fibers.

[0013] Secondly, a method for preparing a crack-resistant rubber bushing is provided, comprising the following steps: A vulcanized adhesive is applied to the inner wall of the first sleeve and the outer wall of the second sleeve. A vulcanizing adhesive is coated onto the surface of a pre-formed elastic matrix; After the reinforcing mesh is completely soaked in rubber mortar, it is evenly wrapped around the surface of the elastic matrix with a preset tension to form an elastic preform with embedded reinforcing mesh. The first sleeve, the second sleeve, and the plurality of the elastomer preforms are loaded into a vulcanizing mold, and a molding core is placed between adjacent elastomer preforms to form the cavity. The mold is subjected to heating and pressure vulcanization treatment. After vulcanization, the mold is demolded to obtain a crack-resistant rubber bushing.

[0014] In some embodiments, the mass mixing ratio of aramid fiber to carbon fiber in the reinforcing mesh is 1:0.5 to 1:2.

[0015] This application provides a crack-resistant rubber bushing and its preparation method. By winding a reinforcing mesh around the surface of an elastic matrix with a preset tension, the stress state and crack propagation conditions of the elastomer under stress are fundamentally changed, thereby significantly improving its crack resistance. From a mechanical perspective, cracking of rubber materials usually originates from local tensile stress exceeding its critical tear energy, leading to crack initiation and propagation. Without prestress, when the bushing is subjected to external loads, the microscopic defects on the surface or inside the elastomer directly bear tensile stress. Once the stress concentration reaches the threshold, cracks will form and gradually propagate. However, after introducing prestressed winding, the reinforcing mesh is equivalent to applying a continuous pre-compression stress field to the elastic matrix. When the tensile stress generated by the external load acts on the elastomer, this pre-compression stress must first be offset, significantly reducing the net tensile stress actually borne by the elastomer, thereby significantly increasing the crack threshold. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the planar structure of the anti-cracking rubber bushing provided in an embodiment of this application; Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the middle AA section; Figure 3 This is a schematic diagram of the cross-sectional structure of the anti-cracking rubber bushing provided in an embodiment of this application; Figure 4 This is a schematic diagram of the composite elastomer structure in the anti-cracking rubber bushing provided in the embodiments of this application; Figure 5 This is a schematic diagram of the reinforcing mesh structure in the anti-cracking rubber bushing provided in the embodiments of this application.

[0018] In the figure: 1. First sleeve; 2. Second sleeve; 3. Composite elastomer; 301. Elastic matrix; 302. Reinforcing mesh; 3021. First stirrup; 3022. Second stirrup; 303. Bonding layer; 4. Cavity; 5. Limiting rib. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] This application provides a crack-resistant rubber bushing that overcomes the inherent limitations of simple material modification in related technologies, which makes it difficult to suppress the generation of cracks in rubber bushings.

[0021] In a first aspect, this application provides a crack-resistant rubber bushing, including a first sleeve 1, a second sleeve 2 coaxially disposed within the first sleeve 1, and a composite elastomer assembly disposed between the first sleeve 1 and the second sleeve 2.

[0022] In this embodiment, the first sleeve 1 and the second sleeve 2 are made of metal, typically carbon steel, stainless steel or aluminum alloy, which are metal materials with high strength and high modulus properties.

[0023] In some alternative embodiments, high-strength engineering plastics, carbon fiber reinforced composites, or other non-metallic composites may also be used. These alternatives are designed to meet lightweight or corrosion-resistant requirements under specific operating conditions.

[0024] In this embodiment, the first sleeve 1 and the second sleeve 2 have circular cross-sections. The inner wall of the first sleeve 1 and the outer wall of the second sleeve 2 can be designed with knurling, pitting or rough texture. These micro-geometric features can form a mechanical interlocking effect with the adhesive layer 303, significantly enhancing the bonding force between the metal sleeve and the elastic substrate 301, and preventing interface peeling under long-term alternating load.

[0025] Furthermore, the composite elastomer assembly is disposed between the first sleeve 1 and the second sleeve 2, and extends axially along the first sleeve 1, including multiple composite elastomers 3 distributed circumferentially along the second sleeve 2, with cavities 4 provided between adjacent composite elastomers 3.

[0026] like Figures 1 to 3 As shown in this application, the composite elastomer assembly includes two composite elastomers 3 and two cavities 4 arranged alternately along the circumference of the second sleeve 2. This symmetrical layout structure of two bodies and two cavities enables the bushing to have balanced mechanical response characteristics in the radial plane. When the vehicle is subjected to alternating loads from the left and right or up and down directions during driving, the two composite elastomers 3 can evenly share the load, avoiding the phenomenon of uneven load caused by excessive force on one side, thereby preventing early fatigue cracking caused by local stress concentration.

[0027] In some optional embodiments, the number and distribution angle of the composite elastomer 3 and the cavity 4 can be flexibly adjusted according to the actual working conditions. For example, three or four composite elastomers 3 can be uniformly distributed circumferentially to further refine the stress distribution grid and improve the isolation effect of high-frequency vibration; or an asymmetric distribution design can be adopted to increase the cross-sectional area of ​​the composite elastomer 3 or reduce the size of the cavity 4 in a specific direction, thereby constructing an anisotropic stiffness matrix to meet the differentiated matching requirements of the suspension system for vertical support stiffness and lateral comfort stiffness.

[0028] The bushing includes a first sleeve 1 and a second sleeve 2 arranged coaxially, with an axially extending composite elastomer assembly between them. This assembly consists of multiple circumferentially distributed composite elastomers 3, and cavities 4 are provided between adjacent composite elastomers 3. This segmented composite elastomer assembly design, compared to the traditional integral rubber ring, can better adapt to multi-directional loads such as axial force, radial force, and torsional moment in automotive suspension or powertrain mountings. The presence of cavities allows the composite elastomers 3 to deform independently, effectively dispersing stress concentration and avoiding structural damage caused by excessive local deformation.

[0029] Furthermore, each composite elastomer 3 includes: The elastic matrix 301 is usually made of rubber materials with excellent elasticity, fatigue resistance and aging resistance, such as EPDM rubber or nitrile rubber. The reinforcing mesh 302 is prestressed and wrapped around the elastic matrix 301. The adhesive layer 303 is placed outside the reinforcing mesh 302 and is disposed between the elastic substrate 301 and the first sleeve 1, and between the elastic substrate 301 and the second sleeve 2.

[0030] Cracking of rubber materials typically originates from local tensile stress exceeding its critical tear energy. This application addresses this by pre-stressing the outer wall of the elastic matrix 301 with a reinforcing mesh 302, effectively applying a continuous pre-compression stress field to the elastic matrix 301. When tensile stress from external loads acts on the elastic matrix 301, this pre-compression stress must first be offset, significantly reducing the net tensile stress actually borne by the elastic matrix 301. This significantly raises the crack threshold and inhibits the initiation and propagation of microcracks. Furthermore, the adhesive layer 303 positioned between the elastic matrix 301 and the first sleeve 1 and the second sleeve 2 ensures a strong connection between the rubber and the metal sleeve, preventing the common problem of rubber debonding after long-term service and guaranteeing effective load transfer.

[0031] Furthermore, such as Figure 4 and Figure 5 As shown, the reinforcing mesh 302 includes: Multiple first stirrups 3021 are arranged around the outside of the elastic matrix 301 at intervals and parallel to each other along the axial direction of the elastic matrix 301.

[0032] In some alternative embodiments, the first stirrup 3021 is spirally wound around the outside of the elastic matrix 301 along the axial direction of the elastic matrix 301.

[0033] Whether using annular stirrups or helical windings, tension is typically applied during the fabrication process. This prestress allows the elastomer to be in a slightly compressed state when unloaded, thereby increasing its tensile crack threshold. In this application, annular stirrups are preferred. Prestress is applied through multiple independent closed loops rather than continuous helices. This utilizes the high modulus of the fiber to achieve a radial hoop effect to resist large loads, while the spacing between the stirrups preserves the local deformation capacity of the elastic matrix. This improves stiffness while avoiding structural hardening due to excessive constraint, which is beneficial for absorbing torsional loads and improving ride comfort. More importantly, this discrete constraint structure has a unique "segmented crack arrest" effect: when microcracks initiate in the rubber under long-term alternating loads, because the stirrups are independent, the cracks are confined within a single stirrup interval, making it difficult for them to continue propagating axially across the stirrup barrier, thus effectively preventing through-cracks. In contrast, if a helical winding structure debonds at a certain interface, the crack may continue to extend along the helical path, leading to extensive peeling failure. Furthermore, the independent annular stirrups primarily bear circumferential tension, exhibiting minimal interference with axial shear and reducing the risk of fiber-rubber interface delamination due to deformation incompatibility. In summary, this structure significantly improves the bushing's fatigue resistance and structural integrity while maintaining necessary flexibility.

[0034] Furthermore, the reinforcing mesh 302 also includes: Multiple second stirrups 3022 are arranged at intervals around the outside of the elastic matrix 301; The plane containing the first stirrup 3021 is perpendicular to the plane containing the second stirrup 3022.

[0035] In this embodiment, the cross-section of the elastic matrix 301 is fan-shaped. The first stirrup 3021 is arranged around the outer surface of the elastic matrix along the radial plane to form a circumferential constraint; the second stirrup 3022 extends along the axial direction of the elastic matrix and is perpendicular to the plane where the first stirrup is located, together forming a bidirectional orthogonal prestressed reinforcement grid.

[0036] A second stirrup 3022 is introduced based on the first stirrup 3021, and the planes of the two stirrups are perpendicular to each other, constructing an orthogonal grid-like prestressed reinforcement structure. The first stirrup 3021 is spaced around the first stirrup 3021 along the axial direction, providing a radial hoop effect, mainly constraining the expansion deformation of the elastic body under radial load; the plane of the second stirrup 3022 is perpendicular to the first stirrup 3021 and orthogonally distributed along the axial direction, used to constrain the shear deformation of the elastic matrix 301 in the axial direction. This orthogonal layout creates a bidirectional precompression stress field on the surface of the elastic matrix 301. When the bushing is subjected to external loads in any direction, at least one set of stirrups is in a direct load-bearing state, which can effectively offset the tensile stress generated in that direction, thereby comprehensively improving the crack resistance. Compared with single-direction stirrups, the orthogonal structure eliminates the weak direction of mechanical properties, avoiding the region from cracking first due to insufficient constraint in a certain direction. At the same time, the grid formed by the bidirectional stirrups divides the surface of the elastic matrix into multiple independent reinforcement units. If a crack initiates in a grid, its propagation will be blocked by adjacent stirrups, making it difficult to cross the grid boundary and form a through crack. Furthermore, the spacing of the orthogonal stirrups does not completely fill the surface of the elastomer, preserving the matrix's local deformation capacity at the grid gaps. This allows the bushing to achieve bidirectional reinforcement while maintaining the necessary flexibility to adapt to complex multidirectional loads. Ultimately, this structure significantly improves the fatigue life and structural integrity of the rubber bushing under combined stress conditions.

[0037] Furthermore, the two ends of the second sleeve 2 extend axially 3-10 mm beyond the ends of the composite elastomer assembly.

[0038] When the bushing is subjected to axial load or deflection, the rubber composite elastomer at the end region usually becomes a stress peak area due to deformation concentration, which is also a high-incidence site for crack initiation. The protruding part of the second sleeve 2 acts as a mechanical baffle, limiting the excessive axial flow or extrusion of the composite elastomer 3 under extreme working conditions, and preventing the end rubber from tearing due to exceeding its limit deformation. The protrusion length is the optimal range after optimization design. If the protrusion length is less than 3mm, the protective effect and guiding function are not obvious, and it is difficult to effectively avoid installation damage; if it is greater than 10mm, it may occupy too much axial installation space, causing interference with surrounding components, or reducing the effective rubber working length, thus affecting the stiffness characteristics of the bushing. Therefore, this size range ensures end protection, stress optimization and installation convenience, while taking into account the space constraints of the overall vehicle layout, achieving the best balance between structural reliability and assembly processability.

[0039] Furthermore, a limiting rib 5 is provided inside the cavity 4. The limiting rib 5 is connected to the inner wall of the first sleeve 1 and extends along the axial direction of the first sleeve 1, and protrudes towards the outer wall of the second sleeve 2.

[0040] During operation, the first sleeve 1 and the second sleeve 2 will move relative to each other. When encountering a large impact load that causes excessive relative displacement, the limiting rib 5 can act as a mechanical stop, contacting the outer wall of the second sleeve 2 or limiting the closing limit of the cavity 4, thereby forcibly constraining the deformation range of the elastic matrix 301. Since bushing cracking mainly originates from the tensile stress generated by the elastic matrix 301 under excessive deformation exceeding its critical tear strength, the limiting rib 5 effectively avoids stress concentration and microcrack initiation caused by extreme working conditions by limiting the strain of the elastic matrix 301 within a safe threshold, fundamentally solving the technical problem of rubber cracking easily occurring at the location of the elastic matrix 301.

[0041] Furthermore, the cross-section of the limiting rib 5 is trapezoidal or semi-circular, and there is a gap between its top end and the outer wall of the second sleeve 2. The size of the gap is smaller than the radial compression of the composite elastomer 3 under the maximum design load.

[0042] Since the gap size is smaller than the radial compression of the composite elastomer 3 under the maximum design load, this means that when the load increases to the design limit range, the limiting rib 5 will contact the second sleeve 2 in advance and form a rigid support. This mechanism forcibly restricts the relative displacement between the first sleeve 1 and the second sleeve 2, locking the deformation of the elastic matrix 301 within a safe range, and preventing the rubber from cracking due to excessive compression causing internal molecular chain breakage or stress concentration.

[0043] Furthermore, the adhesive layer 303 is a vulcanized adhesive layer.

[0044] Furthermore, the reinforcing mesh 302 is a mixed fiber bundle of aramid fiber and carbon fiber.

[0045] Furthermore, the mass mixing ratio of aramid fiber to carbon fiber in the reinforcing mesh 302 is 1:0.5 to 1:2.

[0046] The 302 reinforcing mesh utilizes a hybrid fiber bundle of aramid and carbon fibers. Through the synergistic effect of these two high-performance fibers, an optimized combination of mechanical properties and structural stability is achieved. Carbon fiber possesses extremely high tensile modulus and tensile strength, providing primary rigid support when the bushing bears heavy loads, effectively limiting the macroscopic deformation of the elastic matrix and preventing structural failure due to overload. Aramid fibers, on the other hand, exhibit excellent toughness and elongation at break, absorbing impact energy and delaying the propagation of fatigue cracks under dynamic alternating loads. The combined use of these two fibers creates a complementary reinforcement effect: carbon fiber bears the main load, ensuring the overall stiffness of the reinforcing mesh; aramid fibers impart flexibility to the mesh, allowing it to better adapt to the deformation of the elastic matrix during winding and service without brittle fracture. Furthermore, aramid fibers have good affinity with the rubber matrix, facilitating the bonding between the fiber and rubber interface and reducing the risk of interfacial delamination; the addition of carbon fiber enhances the fatigue resistance and creep resistance of the mesh, ensuring that the prestressed state is maintained during long-term service.

[0047] Secondly, this application provides a method for preparing a crack-resistant rubber bushing, comprising the following steps: S1: Apply a vulcanized adhesive to the inner wall of the first sleeve 1 and the outer wall of the second sleeve 2.

[0048] Before coating, the surfaces of the first sleeve 1 and the second sleeve 2 typically require rigorous pretreatment, including degreasing, sandblasting, or phosphating, to remove surface contaminants and oxide layers, and to create a uniform micro-roughness, thereby increasing the adhesion area and mechanical anchoring effect of the adhesive. The selection of the vulcanizing adhesive must be compatible with the subsequent rubber material, and typically includes a two-layer coating system: the primer chemically couples with the metal surface to form a corrosion-resistant passivation layer; the topcoat contains active groups that can co-crosslink with the rubber during vulcanization. When the elastomer preform is subsequently loaded and heated for vulcanization, the vulcanizing adhesive is activated at high temperature, undergoes a crosslinking reaction with the rubber molecular chains, and simultaneously forms a stable metal-organic compound layer at the metal interface, ultimately achieving integrated chemical bonding between the rubber and the metal.

[0049] S2: Apply a vulcanizing adhesive to the surface of the pre-formed elastic matrix 301.

[0050] After the elastic matrix 301 is prepared using a vulcanization tool, it is cooled to allow the rubber molecular chains to fully relax and solidify after the cross-linking reaction, eliminating thermal stress and internal residual deformation generated during vulcanization. The cooled elastic matrix 301 requires surface cleaning, typically using organic solvents or plasma cleaning, to remove release agent residue, oil, and weak boundary layers, ensuring the wettability and chemical bonding of the subsequent adhesive. The vulcanized adhesive is then uniformly coated onto the cleaned elastic matrix surface. During coating, the active ingredients in the adhesive penetrate into the micropores of the rubber surface, forming physical entanglement with the rubber molecular chains, and undergoing a co-crosslinking reaction through thermal activation during subsequent vulcanization. After coating, the elastic matrix needs to be left to dry in a clean environment to allow the solvent in the adhesive to fully evaporate, forming a uniform, continuous, and viscous thin film layer. At this point, the surface of the elastic matrix possesses an active interface for chemical bonding with the reinforcing mesh and metal sleeve, providing interfacial bonding assurance for subsequent winding and overall vulcanization.

[0051] It should be noted that there is no strict order requirement for performing steps S1 and S2. In practice, the first and second sleeves can be coated first, followed by the preparation and coating of the elastic substrate; or the elastic substrate can be prepared and coated first, followed by the treatment of the metal sleeve. The two processes are independent of each other and do not interfere with each other. They can be flexibly adjusted according to the production flow without affecting the subsequent assembly and vulcanization effects.

[0052] S3: After the reinforcing mesh 302 is completely soaked in rubber mortar, it is evenly wound around the surface of the elastic matrix 301 with a preset tension to form an elastic preform with embedded reinforcing mesh 302.

[0053] The reinforcing mesh 302 is completely impregnated with rubber mortar. This process ensures that the surface of each fiber bundle is fully coated with the mortar, allowing it to penetrate into the gaps within the fiber bundles and eliminate air gaps between the fibers and rubber. This provides a prerequisite for the co-crosslinking of the fibers and the rubber matrix during subsequent vulcanization. After impregnation, the reinforcing mesh 302 is uniformly wound around the surface of the elastic matrix 301 coated with vulcanizing adhesive under a preset tension. The tension is set based on the modulus of the fiber material, the hardness of the elastic matrix 301, and the required prestress level: too low a tension will prevent the establishment of an effective pre-compression stress field in the elastic matrix; too high a tension may cause excessive shrinkage and deformation of the elastic matrix 301 or relaxation failure before subsequent vulcanization. During the winding process, the tension must be kept constant, and the reinforcing mesh must be evenly distributed along the surface of the elastic matrix according to the designed path, ensuring consistent spacing between adjacent stirrups and avoiding overlap or excessive gaps. For orthogonal mesh structures, the stirrups in one direction must be wound first, followed by winding in the vertical direction under the same tension control to form a bidirectional prestressed reinforcement layer. After winding, the reinforcing mesh 302 is tightly attached to the surface of the elastic matrix, and due to the tension, it applies a continuous radial compression to the elastic matrix, forming a prestressed elastomer.

[0054] S4: The first sleeve 1, the second sleeve 2 and multiple elastomer preforms are loaded into the vulcanization mold, and a molding core mold is placed between adjacent elastomer preforms to form a cavity 4.

[0055] The first sleeve 1 and the second sleeve 2 are coaxially installed, and their relative positions are fixed by a positioning mandrel or end face pressure plate on the mold to prevent displacement during mold closing and vulcanization. Multiple elastomer preforms are evenly arranged circumferentially along the second sleeve 2 and embedded in the annular gap between the first sleeve 1 and the second sleeve 2, with their sides contacting the adhesive layer on the inner wall of the first sleeve 1 and the outer wall of the second sleeve 2, respectively. A pre-formed mandrel is placed between adjacent elastomer preforms to form the final shape of cavity 4. After assembly, the mold is closed and locked, so that all components are under pressure and pre-tightened within the mold cavity. The first sleeve 1, the second sleeve 2, the elastomer preforms, and the mandrel together constitute a complete vulcanization cavity.

[0056] S5: The mold is heated and pressurized for vulcanization. After vulcanization, the mold is demolded to obtain a crack-resistant rubber bushing.

[0057] The vulcanization temperature needs to be determined based on the vulcanization characteristic curve of the rubber material, and is usually controlled between 140℃ and 180℃ to allow the rubber molecular chains to undergo a cross-linking reaction under the action of heat. Vulcanization pressure is applied using a hydraulic press or vulcanizing machine. The pressure acts on the mold, causing the components within the mold cavity to fit tightly together. Simultaneously, it promotes the flow of rubber slurry and the elastic matrix 301 under pressure, filling the tiny gaps in the cavity and ensuring sufficient contact between the elastic matrix 301 and the interfaces of the first sleeve 1, the second sleeve 2, and the reinforcing mesh 302. During the heating and pressurization process, multiple chemical reactions occur: the rubber molecular chains in the elastic matrix 301 co-crosslink with the vulcanizing adhesive coated on its surface, forming chemical bonds; the vulcanizing adhesive layer on the inner wall of the first sleeve 1 and the second sleeve 2 simultaneously undergoes a coupling reaction with the elastic matrix 301 and the metal surface; the rubber slurry impregnated on the surface of the reinforcing mesh 302 fuses with the elastic matrix 301 during vulcanization, making the fiber bundles an internal reinforcing skeleton of the elastic matrix 301. The vulcanization time needs to be precisely controlled to ensure that the cross-linking reaction is fully completed without over-vulcanization degradation. After vulcanization, heating is stopped and pressure is maintained for cooling, allowing the rubber molecular chains to solidify in the cross-linked state and eliminating thermal stress. After cooling to the specified temperature, the pressure is released, the mold is opened, the vulcanized part is removed, and the molding core is dismantled to obtain a complete crack-resistant rubber bushing.

[0058] After demolding, the bushing needs to undergo flash trimming and visual inspection to ensure that the composite elastomer 3 is firmly bonded to the sleeve, the cavity shape is intact, and there are no air bubbles or missing adhesive defects. This final step integrates all components into an inseparable whole through chemical cross-linking, permanently anchoring the prestressed reinforcing mesh in the elastic matrix to achieve the designed crack resistance performance.

[0059] Through the complete preparation process from S1 to S5, a systematic construction of the crack-resistant rubber bushing from raw materials to finished product was achieved. Each step is interconnected and works synergistically, ultimately endowing the product with excellent comprehensive performance. Coating the inner and outer walls of the first bushing 1 and the second bushing 2 with a vulcanizing adhesive, as well as coating the surface of the elastic matrix with an adhesive, establishes a chemically bonded interface between the rubber and the metal, ensuring a strong, integrated connection during subsequent vulcanization and fundamentally eliminating the risk of interface delamination. The reinforcing mesh 302, after being impregnated with rubber slurry, is wound around the surface of the elastic matrix under a preset tension. This allows the high-modulus fibers to establish a continuous pre-compression stress field within the elastomer. When the bushing is subjected to external loads, the pre-compression stress effectively counteracts the tensile stress, significantly increasing the crack threshold. Simultaneously, the interfacial bonding formed between the fibers and rubber during impregnation ensures that the reinforcing mesh becomes an internal skeleton of the elastomer after vulcanization, rather than a simple attachment. Assembling each component and molding core into a vulcanization mold ensures the circumferential uniformity of the composite elastomer, the dimensional accuracy of the cavities, and the relative positional relationships between the components, giving the final product the expected multi-directional stiffness characteristics and deformation space. The final high-temperature, high-pressure vulcanization process integrates the elastic matrix 301, reinforcing mesh 302, adhesive layer 303, first sleeve 1, and second sleeve 2 into an inseparable whole through thermochemical cross-linking. The prestressed state is permanently anchored within the product, while eliminating residual stress from the manufacturing process. This organic integration of the entire process results in a product with high-strength chemical bonding, bidirectional prestress reinforcement, and a segmented crack-arresting structure, exhibiting excellent crack resistance, superior interface durability, and stable long-term fatigue life, fully meeting the stringent requirements of automotive suspension and damping systems for highly reliable elastic connecting components.

[0060] In summary, the core innovation of this solution lies in the structural design of the composite elastomer 3. Fiber-reinforced ribs are uniformly arranged on the outer surface of the elastic matrix 301. Through the high modulus of the fibers and prestressed winding, a continuous residual compressive stress field is established on the surface of the elastic matrix 301. When external loads generate tensile stress, this compressive stress can effectively counteract the tensile stress, fundamentally inhibiting crack initiation and propagation. Secondly, through a secondary vulcanization process, the composite elastomer 3 is embedded inside the first sleeve 1 and the second sleeve 2, allowing the fiber-reinforced ribs and the elastic matrix 301 to undergo a co-crosslinking reaction during vulcanization. The fiber bundles are permanently anchored in the elastic matrix 301, fixing and maintaining the prestressed state for a long time. Simultaneously, the interfaces form an integrated structure through chemical bonding, eliminating the risk of interface delamination. Furthermore, the shape of the composite elastomer 3 can be flexibly designed according to the specific working conditions of the bushing, achieving adjustability of stiffness and damping characteristics.

[0061] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0062] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0063] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A crack-resistant rubber bushing, characterized in that, It includes: First sleeve (1); The second sleeve (2) is coaxially disposed inside the first sleeve (1); A composite elastomer assembly is disposed between a first sleeve (1) and a second sleeve (2) and extends axially along the first sleeve (1). It includes a plurality of composite elastomers (3) distributed circumferentially along the second sleeve (2). A cavity (4) is provided between adjacent composite elastomers (3). Each composite elastomer (3) includes: - Elastic matrix (301); - The reinforcing mesh (302) is wrapped around the elastic matrix (301) in a prestressed state; - Adhesive layer (303), placed outside the reinforcing mesh (302), is disposed between the elastic matrix (301) and the first sleeve (1), and between the elastic matrix (301) and the second sleeve (2).

2. The anti-cracking rubber bushing as described in claim 1, characterized in that, The reinforcing mesh (302) includes: A plurality of first stirrups (3021) are arranged around the outside of the elastic matrix (301) at intervals and parallel to each other along the axial direction of the elastic matrix (301).

3. The crack-resistant rubber bushing as described in claim 2, characterized in that: The reinforcing mesh (302) also includes: A plurality of second stirrups (3022) are provided at intervals around the outside of the elastic matrix (301); The plane containing the first stirrup (3021) is perpendicular to the plane containing the second stirrup (3022).

4. The crack-resistant rubber bushing as described in claim 1, characterized in that: The two ends of the second sleeve (2) extend axially 3-10 mm from the end of the composite elastomer assembly, respectively.

5. The anti-cracking rubber bushing as described in claim 1, characterized in that: The cavity (4) is provided with a limiting rib (5), which is connected to the inner wall of the first sleeve (1) and extends along the axis of the first sleeve (1), and protrudes toward the outer wall of the second sleeve (2).

6. The crack-resistant rubber bushing as described in claim 5, characterized in that: The cross-section of the limiting rib (5) is trapezoidal or semi-circular, and there is a gap between its top end and the outer wall of the second sleeve (2). The size of the gap is smaller than the radial compression of the composite elastomer (3) under the maximum design load.

7. The crack-resistant rubber bushing as described in claim 1, characterized in that: The adhesive layer (303) is a vulcanized adhesive layer.

8. The crack-resistant rubber bushing as described in claim 1, characterized in that: The reinforcing mesh (302) is a mixed fiber bundle of aramid fiber and carbon fiber.

9. A method for preparing a crack-resistant rubber bushing as described in any one of claims 1 to 8, characterized in that, Includes the following steps: A vulcanizing adhesive is applied to the inner wall of the first sleeve (1) and the outer wall of the second sleeve (2); A vulcanizing adhesive is coated on the surface of the preformed elastic matrix (301); After the reinforcing mesh (302) is completely soaked in rubber mortar, it is evenly wrapped around the surface of the elastic matrix (301) with a preset tension to form an elastic preform with embedded reinforcing mesh (302); The first sleeve (1), the second sleeve (2) and the plurality of the elastomer preforms are loaded into the vulcanization mold, and a molding core is placed between adjacent elastomer preforms to form the cavity (4). The mold is subjected to heating and pressure vulcanization treatment. After vulcanization, the mold is demolded to obtain crack-resistant rubber bushing.

10. The method for preparing the crack-resistant rubber bushing as described in claim 9, characterized in that: The mass mixing ratio of aramid fiber and carbon fiber in the reinforcing mesh (302) is 1:0.5 to 1:2.

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