A bicycle rim and its manufacturing process

Abstract

The present invention belongs to the technical field of hub processing, and in particular relates to a bicycle rim and its manufacturing process. The rim body has a hollow structure with a wider upper part and a narrower lower part in cross-section. A first cavity is formed inside the rim body. On both sides inside the rim body, a number of buffer belts protruding inwards are formed. On both sides of the top of the rim body, symmetrical anti-bite wheel rims are formed, and the top edge of the anti-bite wheel rim is an arc-shaped structure. In the manufacturing process of the present invention, the extruded profile is directly bent. At this time, the profile has a high plasticity due to its high temperature. After bending, the profile is cut, cooled, etched, and then heat-treated. The rim has a low strength before heat treatment and is easy to process. By this method, a rim with a higher height can be processed, thereby improving the stability and wind-breaking ability of the bicycle during driving. At the same time, the high-profile rim has higher strength and impact resistance and is not easily deformed.

Description

Technical Field

[0001] The present invention belongs to the technical field of hub processing, and particularly relates to a bicycle rim and its manufacturing process. Background Art

[0002] A bicycle hub, that is, a rim, is an important part of a bicycle wheel, undertaking functions such as supporting the wheel, connecting with the axle, and providing rotation. The design and materials of the hub not only affect the performance and riding experience of the bicycle, but also relate to the weight and durability of the whole vehicle; there are many types of hubs, usually including front hubs; rear hubs; integrated hubs; adjustable hubs. According to the selected materials, hubs can be commonly divided into; aluminum alloy; carbon fiber; steel; high-quality hubs play a key role in the riding experience. It not only affects the comfort and controllability of riding, but also affects the transmission efficiency and reaction speed of the whole vehicle. Selecting a suitable hub and its configuration can significantly improve the performance of the vehicle.

[0003] However, due to process limitations, it is difficult to manufacture rims with a relatively high rim width in existing bicycle rims. The height of the rim affects the wind-breaking ability, stability, and shock resistance of the vehicle. When bending a relatively high profile, defects such as wrinkling and cross-section are likely to occur, and the defective rate is relatively high.

[0004] To solve the above problems, it is urgent to propose a high-profile bicycle rim and its manufacturing process. Summary of the Invention

[0005] To solve the problems raised in the above background art. The present invention provides a bicycle rim and its manufacturing process, which has characteristics such as relatively high stability, high wind-breaking ability, and high earthquake resistance, can obtain high-quality high-profile rims, and changes the problem that it is difficult to manufacture high-profile rims in the existing process.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a bicycle rim. The rim includes an integrally formed rim body. The cross-section of the rim body is a hollow structure that is wider at the top and narrower at the bottom. A first cavity is formed inside the rim body. A number of buffer bands protruding inward are formed on the inner circumferences of both sides inside the rim body. Symmetrical anti-bite wheel rims are formed on both sides of the top of the rim body. The top edge of the anti-bite wheel rim is an arc surface structure or a groove structure; a second cavity is opened inside the anti-bite wheel rim, and the second cavity and the anti-bite wheel rim form a hollow convex rim. A tire card slot is formed on the surface of the rim body at the middle position between the two anti-bite wheel rims;

[0008] Among them, the buffer bands inside the rim body are a number of uniformly distributed corrugated groove structures.

[0009] Preferably, the corrugation period of the corrugated groove structure is 5-8 mm, the wave amplitude is 1.2-1.8 mm, and the corrugation inclination angle is 45±5°.

[0010] Preferably, the top edge of the anti-bite wheel edge 13 is a continuous arc with a radius of 2.5 mm - 3 mm.

[0011] Preferably, a plurality of mounting holes are provided on the inner side of the rim body.

[0012] Preferably, the outer surface of the rim body has a plating layer.

[0013] Preferably, the height of the rim body is 45 mm to 65 mm.

[0014] In a second aspect, the present invention also provides a manufacturing process for a bicycle rim, which is applied to the aforementioned bicycle rim and includes the following steps:

[0015] S1, using an eddy current heating device to heat and soften an aluminum-magnesium alloy rod, and then using a hydraulic profile extruder, the pressure of the hydraulic profile extruder cooperates with a mold to extrude the rod into a profile. The cross-sectional shape of the mold cavity matches the final cross-sectional shape of the rim body, including a hollow structure that is wider at the top and narrower at the bottom, pre-formed buffer belt grooves that protrude inward on both sides, and a forming cavity for the anti-bite wheel edge at the top;

[0016] S2, after the profile is extruded, direct bending processing is carried out. Specifically: when the profile is in a high-temperature state of 380 - 450 °C, use the profiling roller group of a metal bending machine for bending processing. The profile of the roller group matches the cross-sectional shape of the rim body. When bending, the wider part at the top faces outward, and through the control of the roller pressure, directional deformation is generated on the buffer belt side; the extruded profile is bent into a spiral shape of 3 to 5 turns, and the remaining profile is cut off;

[0017] S3, put the spiral profile into a cutting machine and perform cutting processing along the cross-sectional direction to form a number of annular rims with notches;

[0018] S4, dissipate heat from the rim and cool it to room temperature;

[0019] S5, pickle the cooled rim to clean impurities and contaminants on the surface, and at the same time etch the surface;

[0020] S6, perform heat treatment on the rim processed in step S5, including solution treatment and aging treatment;

[0021] S7, weld the notches of the heat-treated rim;

[0022] S8, after welding is completed, perform milling processing to remove the weld scars generated by welding;

[0023] S9. After removing the welding scars, electroplating is carried out to form a coating on the surface of the rim.

[0024] S10. The rim is evenly drilled to provide holes for installing the spoke assembly and the tire valve.

[0025] Preferably, after cutting the remaining profiles in step S2, it further includes: clamping out the bent profiles by a manipulator, and the metal bending machine continues to perform the bending process on the next section of the profiles.

[0026] Preferably, the cutting process in step S3 is specifically: putting the spiral profiles into a cutting machine by a manipulator, and cutting all the turns of the profiles in one cut along the cross-sectional direction to form several annular rims with notches.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The manufacturing process of the present invention directly performs bending on the extruded profiles, taking advantage of the relatively high temperature reached by the profiles during the extrusion process to endow them with good plasticity, making the bending process simpler and more efficient. Specifically, performing the bending operation at a high temperature can effectively reduce the processing difficulty of the material, while improving the bending quality and ensuring the shape accuracy and consistency of the rim.

[0029] The profiles after bending will undergo subsequent processes such as cutting, cooling, and etching. This series of treatments not only ensure that the profiles meet the designed dimensions and appearance requirements, but also lay the foundation for the subsequent heat treatment. During the heat treatment process, although the strength of the rim is relatively low at this stage, it also makes the material easier to further process. After heat treatment, the strength of the material will be significantly improved, thus greatly enhancing the overall performance of the rim.

[0030] The high-profile rim manufactured by this process has a higher height and strength. The high-profile rim not only improves the driving stability and wind-breaking ability of the bicycle, but also, due to its superior geometric shape and structural design, can effectively disperse impacts and pressures, thereby enhancing the impact resistance and rigidity of the entire rim. This characteristic makes the rim less likely to deform when facing uneven roads, potholes, etc., thus providing a safer and more reliable user experience for cyclists.

[0031] In addition, the design of the high-profile rim also helps to improve the aerodynamic performance of cycling and reduce wind resistance. The reduction of wind resistance can enable cyclists to feel less resistance during long rides, enhancing the efficiency and speed performance of cycling. This rim design significantly promotes the development of bicycle technology, enabling it to fully exhibit excellent performance in both competitive and daily cycling.

[0032] In summary, the manufacturing process of the present invention optimizes the bending process and heat treatment process of the profile, not only improving the strength and performance of the rim, but also significantly reducing the processing difficulty. This innovative process realizes the improvement of the high-profile rim in terms of stability, impact resistance and aerodynamic performance, bringing a better riding experience to consumers and promoting the technological progress and development of the bicycle industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0034] Figure 1 is a schematic structural diagram of the rim body of Embodiment 1 of the present invention;

[0035] Figure 2 is a three-dimensional schematic diagram of the cross-section of the rim body of Embodiment 1 of the present invention;

[0036] Figure 3 is a schematic cross-sectional structure diagram of the rim body of Embodiment 1 of the present invention;

[0037] Figure 4 is a schematic cross-sectional structure diagram of the rim body of Embodiment 2 of the present invention;

[0038] In the figure: 1, rim body; 11, first cavity; 12, second cavity; 13, anti-biting wheel edge; 14, tire slot; 15, buffer belt. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] Embodiment 1

[0041] As Figures 1 to 3 shown;

[0042] A bicycle rim, comprising an integrally formed rim body 1, the cross-section of the rim body 1 being a hollow structure that is wider at the top and narrower at the bottom. A first cavity 11 is formed inside the rim body 1. On both inner sides of the inside of the rim body 1, a number of buffer bands 15 that protrude inward are formed. On both sides of the top of the rim body 1, symmetrical anti-bite wheel rims 13 are formed. The top edge of the anti-bite wheel rim 13 is an arc-shaped structure. A second cavity 12 is formed inside the anti-bite wheel rim 13. The second cavity 12 and the anti-bite wheel rim 13 form a hollow convex rim. On the surface of the rim body 1, a tire card slot 14 is formed at the middle position between the two anti-bite wheel rims 13.

[0043] In this embodiment: The hub of the bicycle, that is, the rim, plays a crucial role throughout the ride. It not only affects the stability and wind-breaking ability of the ride, but also is directly related to the impact resistance and the service life of the tire. In order to improve the overall performance of the bicycle, the present invention designs a new type of rim body 1, which has a relatively high rim design, aiming to improve the mechanical properties and structural stability of the hub.

[0044] In this design, the rim body 1 adopts the structural design of the first cavity 11. This innovative design successfully reduces the overall weight of the rim. The reduced weight helps to improve the overall performance of the bicycle, reduce the energy consumption during the ride, and thus improve the efficiency and comfort of the ride.

[0045] In the embodiment of the present invention, as Figures 2 - 3 shown, the number of buffer bands 15 that protrude inward are a number of uniformly distributed corrugated groove structures, symmetrically distributed on both inner sides of the rim body 1, with a depth of about 2.5 - 3 mm from the inner wall surface. The buffer bands 15 are integrally formed with the rim body 1.

[0046] In the preferred embodiment of the present invention, for the corrugated groove structure of the buffer band 15, the corrugation period is 5 - 8 mm, the wave amplitude is 1.2 - 1.8 mm, and the corrugation inclination angle is 45 ± 5°.

[0047] Through the buffer strip 15 with a corrugated groove structure, the present invention can play a role in stress buffering during the bending process of the rim profile. Specifically, during profile extrusion, the corrugated preformed groove in the die guides the metal flow to form an initial stress release channel; during high-temperature bending, the corrugated structure of the buffer strip 15 allows stress to concentrate preferentially at the grooves of the buffer strip 15, avoiding transmission to key structures of the rim, such as the anti-bite wheel edge 13 or the welding notch, etc. Specifically, during bending, the outer-ring metal of the rim body 1 is stretched, and the corrugated structure can absorb the elongation through corrugation expansion; during bending, the inner-ring metal of the rim body 1 is compressed, and the corrugated structure can provide contraction space through corrugation shrinkage. Thus, the stress during high-temperature bending can be alleviated. Through finite element analysis and physical experiment tests, the present invention finds that compared with the traditional rim structure without the buffer strip 15, the buffer strip 15 with a corrugated groove structure of the present invention can reduce the stress concentration coefficient from 3.8 to 2.1 under the impact condition of 25 km / h, and can reduce the peak bending stress by up to 42%, which undoubtedly breaks through the technical difficulty of ineffective stress alleviation during traditional rim processing.

[0048] Through the buffer strip 15 with a corrugated groove structure, the present invention can also play a role in improving the load-bearing capacity during the use of the rim. Specifically, first, the corrugated structure can convert the radial load force F into multi-directional component forces, which can be specifically expressed as: F = F_{vertical}·sinθ + F_{horizontal}·cosθ, where θ is the corrugation inclination angle, F_{vertical} is the component force of the radial load force F in the vertical direction, and F_{horizontal} is the component force of the radial load force F in the horizontal direction. Dynamic tests show that the rim with the buffer strip 15 of the present invention has a more uniform load distribution, increasing the radial stiffness of the rim by 22% while reducing the weight by 9%. Second, the corrugated units of the corrugated structure have a progressive response from elastic deformation to plastic deformation when loaded. Through drop hammer experiments, it is proved that the rim with the buffer strip 15 of the present invention can absorb 15 - 18% more impact energy.

[0049] It can be seen that the buffer strip 15 can effectively reduce the stress of the metal material generated due to bending processing, enabling the inner-ring metal to have a movable space during contraction and ensuring that the outer-ring metal can adapt to the requirements of tensile deformation. In this way, the reject rate during the production of high-profile wheels is effectively reduced, the yield rate of the product during the processing is improved, and the production efficiency is significantly increased.

[0050] In addition, compared with the traditional flat structure, the corrugated structure of the buffer strip 15 can more effectively absorb and disperse the instantaneous impact and vibration generated during the bending process. This buffering effect will significantly reduce the risk of damage caused by metal plastic deformation during the processing, thereby improving the overall production yield of high-profile rims. At the same time, the corrugated design of the material also enhances the toughness of the rim, enabling it to better resist external impacts during use.

[0051] During actual riding, the performance of the wheel rim is particularly affected by the severe impacts during turning and bumpy rides. When turning / bumpy, due to the concentration of weight / pressure on the edge of the wheel hub, a large shear force will be generated at the edge positions of the tire and the wheel hub. This shear force is likely to cause rim cutting damage to the tire (commonly known as snake bite rupture in the industry). To solve the problem of rim cutting damage in existing wheel rims, the wheel rim body 1 of the present invention is designed with anti-bite rims 13 on both sides of the top. This design is in direct contact with the bicycle tire and adopts an arc surface design, which can effectively disperse the shear force concentrated here. This dispersion mechanism significantly reduces the occurrence probability of the snake bite phenomenon and enhances the safety and stability of riding.

[0052] Specifically, the top edge of the anti-bite rim 13 is a continuous arc with a radius of 2.5 mm - 3 mm; the second cavity 12 forms a flexible deformation zone, where the wall thickness of the second cavity 12 in the anti-bite rim 13 is 1.2 - 1.5 mm; at the same time, to improve the durability of the anti-bite rim 13, electroplating treatment is carried out on the contact surface, and the thickness of the electroplating layer is about 1 μm.

[0053] In this embodiment: Through the continuous arc design of the top edge of the anti-bite rim 13, the stress can be effectively dispersed, significantly reducing the risk of rim cutting damage and enhancing the safety and stability of riding; the combination of the second cavity 12 and the anti-bite rim 13 constitutes a hollow convex rim. This innovative structure not only effectively reduces the overall weight of the wheel rim body 1, but also the hollow structure absorbs energy through plastic deformation, which also plays a significant role in enhancing performance.

[0054] The design of the hollow convex rim enables the wheel rim body 1 to be lighter while maintaining strength and rigidity, reducing the amount of material used. This lightweight design has a positive significance for improving the overall performance of the bicycle. Especially when riding, it reduces inertia, improves acceleration performance, and enhances the rider's control experience. At the same time, reducing the weight of the wheel rim helps the rider reduce fatigue during long-term use and makes riding more relaxed and enjoyable.

[0055] In addition, the existence of the second cavity 12 is not only for weight reduction, but more importantly, it further improves the buffering performance of the anti-bite rim 13. This cavity utilizes the elastic characteristics of air and can effectively absorb part of the impact force when the wheel rim is subjected to external impact or pressure. This buffering effect reduces the severe shear force generated when the tire contacts the ground and significantly reduces the risk of snake bite (the phenomenon that the tire sidewall is pinched and ruptured).

[0056] The anti-bite wheel rim 13 is designed with an arc structure. Its combination with the second cavity 12 creates an effect that transcends traditional anti-bite designs. At the same time, the above design of the anti-bite wheel rim 13 also cooperates with the buffer belt 15 with a corrugated structure. The corrugated structure of the buffer belt 15 provides radial elasticity (radial refers to the direction perpendicular to the rotation axis of the wheel rim (i.e., the wheel radius direction). Radial elasticity means that when the wheel rim body is stretched (outer ring), the corrugations unfold to absorb the extension deformation and reduce stress concentration. When the wheel rim body is compressed (inner ring), the corrugations contract to provide contraction space and avoid wrinkling), and the cavity structure of the anti-bite wheel rim 13 provides axial flexibility (axial refers to the direction parallel to the rotation axis of the wheel rim (i.e., the wheel width direction). Axial flexibility means that when the cavity structure of the anti-bite wheel rim 13 is subjected to a lateral impact, the second cavity 12 absorbs energy through plastic deformation, and the arc surface / groove design disperses the contact stress), achieving system stiffness matching; when subjected to a severe impact, the buffer belt 15 first absorbs high-frequency vibrations, and the anti-bite wheel rim 13 then dissipates low-frequency energy, thereby optimizing the dynamic response.

[0057] The design of the anti-bite wheel rim 13 of the present invention through the innovative design of arc surface contact + hollow energy absorption. When the tire runs on the road surface, the dynamic loads and shear forces caused by the uneven road surface will be evenly distributed to the wheel rim body 1 through the anti-bite wheel rim 13. This design not only enhances the cooperation between the tire and the wheel rim, but also utilizes the elastic absorption characteristics of the second cavity 12 to further improve the overall stability and safety.

[0058] In addition, a tire slot 14 is provided in the wheel rim body 1. This slot can not only accurately position the tire, but also accommodate the end of the support spoke of the bicycle. This design effectively prevents the contact between the tire and the end of the support spoke, further protecting the tire and extending its service life. Through this protective measure, the vehicle owner does not need to worry about accidental damage during the riding process, thereby improving the overall safety and reliability of the riding.

[0059] In an alternative embodiment, a plurality of mounting holes are provided on the inner side of the wheel rim body 1.

[0060] In this embodiment: A plurality of mounting holes are provided on the inner side of the wheel rim body 1. This design plays an important role in the structural stability and functionality of the wheel rim. These mounting holes are not only used to install key components such as wheel spokes and valve cores, but also ensure the tight connection between the wheel rim body 1 and other components, thereby improving the safety and reliability of the whole vehicle.

[0061] Specifically, the provision of the mounting holes allows the wheel spokes to be evenly distributed on the rim body 1. This design can effectively transfer the forces exerted on the wheel evenly to the rim, enhancing the strength of the overall structure. When riding, when the wheel bears the impact force from the ground or the centrifugal force during driving, the spokes are tightly connected to the rim body 1 through the mounting holes, ensuring the effective transfer of forces and reducing the occurrence of local stress concentration, thereby improving the durability and service life of the wheel.

[0062] The design of the mounting holes also enables more flexible combination between the rim body 1 and other components, facilitating future adaptation with different types of wheel accessories and allowing for quick replacement and adjustment according to the needs of the rider. Whether it is a lightweight wheel for racing or a durable mountain biking accessory, the diverse mounting hole designs can meet the needs of riders with different styles and requirements.

[0063] Furthermore:

[0064] In an alternative embodiment, the outer surface of the rim body 1 has a plating layer.

[0065] In this embodiment, the outer surface of the rim body 1 having a plating layer not only has significant implications for enhancing the functionality of the rim, but also makes an important contribution to its aesthetics. The application of the plating layer provides the rim body 1 with higher surface hardness and excellent corrosion resistance, thereby extending its service life and improving safety.

[0066] In terms of enhancing hardness, the plating layer enables the rim to better resist wear when subjected to various external impacts and frictions. This increased hardness helps to keep the rim intact during long rides and under different terrain conditions, reducing the occurrence of surface scratches and damages.

[0067] In terms of corrosion resistance, the plating layer provides an effective protective barrier for the rim, blocking the erosion of potential corrosive substances such as moisture, salts, acids, and alkalis. It can effectively prevent rusting and oxidation, keeping the appearance and performance of the rim as good as new. This corrosion-resistant property ensures the stability and safety of the rim under various climatic conditions, enhancing the durability of the entire bicycle.

[0068] In addition, the plating treatment can also significantly improve the ornamental value of the rim. The smooth and shiny plated surface can attract the attention of riders and consumers, adding a layer of style and modernity to the rim body 1. This aesthetic surface treatment not only enhances the overall value of the product, but also meets the consumers' pursuit of personalization and visual appeal, adding more trendy elements to cycling.

[0069] Furthermore:

[0070] In an alternative embodiment, the height of the rim body 1 ranges from 45 mm to 65 mm.

[0071] In this embodiment: The height of the rim body 1 of the present invention can reach 45 mm to 65 mm, exceeding the common rim heights on the market (generally 20 - 35 mm). The higher rim body 1 performs excellently in terms of air-breaking performance. Its increased height enables the rim to delay the separation of airflows during driving, reduce the wake vortices, cut through the air more effectively, and reduce the resistance of the airflows. This design is particularly suitable for high-speed cycling, can significantly reduce air resistance, improve the speed performance of the cyclist, and the increased rim height also directly enhances the stability of the vehicle during high-speed driving. In the case of high-speed cycling, the influence of airflows on the wheels may lead to unstable dynamic effects, while the rim design with a greater height helps to enhance the stability of the wheels, thereby reducing the feeling of bumps and shakes.

[0072] Meanwhile, the high-profile design of the rim body 1 also achieves the effect of structural strengthening by increasing the height of the rim cross-section. Specifically, through testing, when the high-profile design of the rim body 1 of the present invention is within the height range of 45 - 65 mm, the measured bending stiffness is increased to 3.3 times that of the traditional low-profile rim, significantly enhancing the anti-deformation ability.

[0073] Furthermore, the high-profile design of the rim body 1 also achieves the effect of suppressing vibrations by increasing the height of the rim cross-section. Specifically, the natural frequency of the high-profile structure (≈85 Hz) is far from the road surface excitation frequency band (5 - 30 Hz), thus well suppressing vibrations.

[0074] Embodiment Two

[0075] As Figure 4 shown, the present invention also provides a bicycle rim, which is different from Embodiment One only in the anti-biting rim edge 13, and the rest of the structure is the same as that of Embodiment One, so it will not be elaborated here. To further enhance the performance of the anti-biting rim edge 13, a groove structure is added to the top edge of the anti-biting rim edge 13 in this embodiment.

[0076] The primary function of the groove design is to disperse the shear force concentrated at the anti-biting rim edge 13. During bicycle riding, the tire and the rim edge will be subjected to greater pressure, especially when turning, bumping, or quickly going downhill, and the contact part between the rim and the tire often bears huge impact forces. The traditional anti-biting rim edge 13 cannot effectively disperse these forces and is prone to generating cracks or damages at the contact points. However, the design with the added grooves can create multiple stress points on the rim surface, slow down and disperse the concentrated action of external forces, thereby significantly enhancing the anti-compression ability of the rim when encountering impacts and reducing the risk of rim deformation and damage.

[0077] Secondly, the groove structure reduces the friction between the tire and the rim. The groove structure of the anti-bite wheel edge 13 can effectively reduce the friction between the tire and the rim, especially when riding at high speed, excessive friction can easily cause tire wear and even scratches. The groove provides a tiny air gap and buffer zone, so that during the rotation process, the contact force between the rim and the tire is properly distributed, effectively reducing the friction coefficient, thereby extending the service life of the tire and the rim.

[0078] In addition, the groove design is not only to increase the compression resistance of the rim, but also to improve the stability and rigidity of the top structure of the rim by optimizing the force distribution. Due to the presence of the groove, the anti-bite wheel edge 13 can distribute the stress more evenly when subjected to external force, reducing the possibility of local plastic deformation or fracture of the rim due to excessive local stress. Especially at the connection between the tire and the rim, the addition of the groove improves the bearing capacity of the entire structure.

[0079] Although the addition of grooves adds a certain degree of complexity to the manufacturing process of the rim, due to its subtle depth and width, the grooves as a whole do not have too much impact on the weight of the rim. On the contrary, it achieves a lightweight design of the rim by optimizing the use of materials while ensuring sufficient strength and performance. The reduced weight helps improve the acceleration performance and handling flexibility of the bicycle and reduce energy consumption during riding.

[0080] Embodiment 3

[0081] The present invention also includes a manufacturing process for a bicycle rim, which is used to form the bicycle rims described in the first and second embodiments. In order to clearly illustrate the specific manufacturing process of the present invention, the following process will be carried out by taking the preparation of the bicycle rim of the first embodiment as an example, and specifically includes the following steps:

[0082] S1, using eddy current heating equipment to heat and soften the aluminum-magnesium alloy bar, and then using a hydraulic profile extruder and a pressure-matching die of the hydraulic profile extruder to extrude the bar into a profile; specifically,

[0083] First, material selection is performed: the wheel rim of the present invention adopts high-strength aluminum-magnesium alloy material with excellent strength and light weight characteristics. Material selection directly affects the comprehensive performance of the wheel rim. Aluminum-magnesium alloy has high strength and corrosion resistance, while further reducing the weight of the wheel rim.

[0084] In the preferred embodiment of the present invention, before formally entering into production, the material is also pickled to remove oxides, impurities and oil stains on the surface in preparation for subsequent processing.

[0085] Secondly, profile extrusion is carried out: the aluminum-magnesium alloy billet is heated to a softened state by an eddy current heating device, and the temperature is controlled between 400 - 500 °C. Then, the softened billet is extruded into shape by a hydraulic profile extruder in cooperation with the special mold of the present invention. During the extrusion process, ensure that the geometric shape and dimensions of the mold meet the design requirements of the rim, and a high-strength rim profile is formed.

[0086] Furthermore, the special mold includes an upper mold and a lower mold, and a cavity structure is formed between the upper mold and the lower mold in cooperation. The cross-sectional shape of the cavity structure of the special mold in step S1 matches the final cross-sectional shape of the rim body 1, and includes a hollow structure with a wider upper part and a narrower lower part, a preformed buffer zone groove protruding inward on both sides, and a top anti-bite wheel rim forming cavity.

[0087] The buffer zone preformed groove of the mold is designed as a corrugated strip-shaped groove, with a depth of 1 / 3 - 1 / 2 of the profile thickness and a spacing of 3 - 5 mm;

[0088] The cross-section of the profile after extrusion by the special mold includes: a main structure with a wider upper part and a narrower lower part (for example, the width ratio is 1.2:1), preformed buffer zone protrusions on both sides (for example, with a height of 2 - 3 mm), and a thickened edge at the top for preparing to form an anti-bite wheel rim;

[0089] S2, after the profile is extruded, bending processing is directly carried out;

[0090] In an alternative embodiment, the bending processing in S2 is specifically: while the profile is in a high-temperature state of 380 - 450 °C (the high-temperature state of 380 - 450 °C can ensure that the material has sufficient plasticity and avoid cracks or damage. This process enhances the structural stability of the rim and optimizes the geometric shape), the profiling roller group of a metal bending machine is used for bending processing. The profile of the roller group matches the cross-sectional shape of the rim body. When bending, the wider upper part faces outward, and directional deformation is generated on the buffer zone side by controlling the roller pressure; the extruded profile is bent into a spiral shape of 3 to 5 turns, the remaining profile is cut off, and the bent profile is clamped out by a manipulator, and the metal bending machine continues to carry out the bending processing of the next section of the profile.

[0091] It should be noted that: in the process of manufacturing high-profile wheels, due to the direct bending processing after profile extrusion, the high-temperature aluminum-magnesium alloy profile has better plasticity. This improvement in plasticity enables the metal material to be more easily stretched and contracted during the bending process, and thus form a three-dimensional and complex high-profile wheel shape, so as to meet the design requirements.

[0092] In particular, a buffer strip 15 is added to the internal design of the rim body 1. This design not only enhances the overall structural strength of the wheel hub but also effectively absorbs the impacts and vibrations generated during use. The presence of the buffer strip 15 allows the rim body to effectively relieve the concentration of internal and external stresses when undergoing bending processing. The wheel hub processed in this way not only has higher toughness and stability in structure but also can maintain better performance under dynamic loads.

[0093] In addition, due to the high adaptability and controllability of the profile during the forming process, the manufactured high-profile wheel hub also achieves a good balance in terms of weight and strength. This design concept enables the wheel hub to effectively improve the handling and safety of the vehicle in practical applications, especially being particularly prominent during high-speed riding or on complex terrains.

[0094] S3. Place the spiral profile into the cutting machine and perform cutting along the cross-sectional direction.

[0095] Cutting process: The bent spiral profile will enter the cutting machine for cutting and be cut off in one knife along the cross-sectional direction to form several annular rims with notches. This cutting operation can ensure that the size and shape of each part of the rim meet the accuracy requirements. Specifically:

[0096] Place the spiral profile in a cutting machine equipped with a limiting fixture.

[0097] Perform a one-time cut along the cross-sectional direction perpendicular to the spiral axis.

[0098] After cutting, several blank open annular rims with a standard circumference error of ±5% are formed.

[0099] S4. Cool and dissipate heat to room temperature.

[0100] Cooling and heat dissipation: The cut rim is quickly cooled to room temperature. During the cooling process, the rim is kept in a radially constrained state to ensure that the shape of the rim remains stable and to avoid deformation caused by temperature differences.

[0101] Furthermore, cool it down to room temperature at a rate of 10 - 15 °C / min in a temperature-controlled cooling chamber.

[0102] S5. Pickle the rim to clean the surface impurities and contaminants and etch the surface at the same time. Specifically:

[0103] Pickling and cleaning: After the rim is cooled, it enters the pickling tank. Clean the oxide layer, impurities, and contaminants on the surface of the rim through a mixed acid solution with a pH of 3.5 - 4.0. Pickling not only improves the surface finish of the rim but also effectively removes the stains during the production process. The pickling time is 15 - 20 minutes.

[0104] Surface etching: After pickling, surface etching treatment is carried out to ensure the uniformity of the rim surface and improve the electroplating effect.

[0105] Due to the pressure exerted on the profile surface during bending processing, there are certain scratches and oil stains on the profile surface. An oxide layer is generated on the profile surface during the cooling process. In order to facilitate the subsequent repair of the rim surface, pickling is performed on the rim at this time, which can wash away the surface stains. Hydrochloric acid, sulfuric acid, phosphoric acid and other pickling reagents are used during the pickling process. The purpose is to remove the stains on the rim surface and the oxide layer on the rim surface, so as to facilitate the subsequent electroplating treatment of the rim surface.

[0106] S6, heat-treat the rim to improve the strength of the rim; specifically include:

[0107] Solution and aging treatment: The rim after pickling and etching treatment enters the heat treatment furnace. In the furnace, the rim undergoes solution treatment (such as heating to 520 - 550 °C and holding for a period of time, such as 1 - 1.5 hours) to make the alloying elements evenly distributed. Then aging treatment is carried out (such as heating to 160 °C and holding for 8 hours). This step significantly improves the strength and hardness of the rim, and improves its wear resistance and impact resistance.

[0108] When performing heat treatment, the rim is in an environment with protective gas under high temperature and high pressure. After heating, holding, and cooling, the metallographic structure of the metal changes, thereby improving the overall quality and strength of the rim.

[0109] S7, weld the notch of the heat-treated rim; adopt friction welding process, welding pressure 8 - 10 MPa; rotational speed 1200 - 1500 rpm, welding time 30 - 45 seconds;

[0110] Welding: Weld the notch formed by cutting in step S3 of the heat-treated rim. Adopt friction welding technology to connect the rim joints. Friction welding can ensure that the joint strength is consistent with the rim body and avoid defects caused by improper welding.

[0111] When welding, by means of friction welding, the two ends of the rim are respectively installed on the two clamping platforms of the friction welding machine. After high-speed relative oscillation, the two ends of the rim rub violently, generating high temperature to achieve welding. Adopting friction welding can ensure that the strength of the welded part of the rim is consistent with the strength of the rim itself. It belongs to the same material. This method can avoid uneven mass distribution of the rim and further improve the stability of the rim.

[0112] S8, after welding is completed, milling processing is carried out to remove the welding scars generated by welding; mill the welding reinforcement, and control the surface roughness below Ra3.2 to ensure the flatness and dimensional accuracy of the rim.

[0113] After removing the welding scars in S9, electroplating is carried out to form a plating layer on the surface of the rim. Specifically, for electroplating: after milling, electroplating treatment is performed on the surface of the rim. Through anodic electroplating technology, the plating layer is evenly covered on the surface of the rim to improve its corrosion resistance, wear resistance and appearance quality. Commonly used electroplated metals include nickel, chromium, etc. The thickness of the electroplated layer needs to be strictly controlled to ensure the service performance and durability of the rim. For example, first deposit a 5-8μm nickel bottom layer, and then deposit a 10-15μm hard chromium layer.

[0114] Using anodic electroplating technology, according to requirements, chromium plating, nickel plating, etc. can be carried out on the surface of the rim, which can improve the surface smoothness, corrosion resistance and surface strength of the rim. Since the surface oxide layer has been removed by pickling, it is beneficial for the plating layer to adhere evenly and firmly to the surface of the rim.

[0115] In S10, the rim is evenly drilled to provide holes for installing the spoke assembly and the tire valve. A CNC drill is used to machine the spoke holes; the angular error of the hole position spacing is ≤0.5°. Specifically: according to the design requirements, precision drilling is carried out at the installation holes of the rim for the holes of the spokes and the tire valve. A CNC device is used to accurately control the hole position and hole diameter (such as the hole diameter is 2.5±0.05mm) to ensure the tight fit between the spokes and the rim and avoid rim deformation or unstable performance caused by inaccurate hole positions.

[0116] After step S10, it also includes:

[0117] Final inspection and quality control: After completing all the above technological processes, strict quality inspection is carried out to ensure that the strength, dimensions, appearance, welding quality, surface treatment effect, etc. of the rim meet the standards. Performance testing: Some rims are tested under simulated use environments to test the impact resistance, anti-deformation ability, corrosion resistance and service life of the rims, etc., to ensure that each product meets the standards.

[0118] It further includes packaging and ex-factory: The rims that have passed the quality inspection are cleaned, dried, and packaged in a suitable way to ensure that they are not damaged during transportation. Ex-factory: The rims after packaging enter the warehouse and are ready for ex-factory to ensure that the products can be delivered to customers on time.

[0119] Working principle and usage process of the present invention: The rim body 1 of the present invention adopts the structural design of the first cavity 11. This innovative design successfully reduces the overall weight of the rim. The reduced weight helps to improve the overall performance of the bicycle, reduce energy consumption during cycling, and thus improve the cycling efficiency and comfort. At the same time, the buffer strip 15 provided inside the rim body 1 plays an important role in the bending process of the rim profile. The buffer strip 15 can effectively reduce the stress of the metal material generated due to bending processing, enabling the inner ring metal to have movable space during contraction and ensuring that the outer ring metal can adapt to the requirements of tensile deformation. In this way, the defective rate during the production of high-profile wheels is effectively reduced, the yield rate of the product during the processing is improved, and the production efficiency is significantly increased.

[0120] In addition, a tire slot 14 is provided in the rim body 1. This slot can not only accurately position the tire but also accommodate the end of the support spoke of the bicycle. This design effectively prevents the contact between the tire and the end of the support spoke, further protecting the tire and extending its service life. Through this protective measure, the vehicle owner does not need to worry about accidental damage during cycling, thereby improving the overall cycling safety and reliability; The manufacturing process adopted by the rim body 1 of the present invention directly bends the extruded aluminum-magnesium alloy profile. Utilizing the relatively high temperature reached by the profile during extrusion, it endows the profile with good plasticity, making the bending process simpler and more efficient. Conducting the bending operation at a high temperature can effectively reduce the processing difficulty of the material, improve the bending quality at the same time, and ensure the shape accuracy and consistency of the rim.

[0121] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A manufacturing process for a bicycle rim, applied to the manufacture of a bicycle rim, characterized in that: The bicycle rim is a high-profile rim, including an integrally formed rim body (1). The height of the rim body (1) is 45 mm to 65 mm. The cross-section of the rim body (1) is a hollow structure that is wider at the top and narrower at the bottom. A first cavity (11) is formed inside the rim body (1). A number of buffer bands (15) protruding inward are formed on the inner circumferences of both sides inside the rim body (1). Symmetrical anti-bite wheel rims (13) are formed on both sides of the top of the rim body (1). The top edge of the anti-bite wheel rim (13) is a groove structure; a second cavity (12) is formed inside the anti-bite wheel rim (13). The second cavity (12) and the anti-bite wheel rim (13) form a hollow convex rim. The hollow convex rim includes two side edges, a top groove, a bottom edge, and an arc structure. Among them, the two side edges, the top groove, and the bottom edge are connected by an arc structure. A tire card slot (14) is formed on the surface of the rim body (1) at the middle position between the two anti-bite wheel rims (13). The tire card slot (14) is connected to the side of the anti-bite wheel rim (13), and the connection part and the bottom edge are in an arc structure; Among them, the buffer bands (15) inside the rim body (1) are a number of uniformly distributed corrugated groove structures; the corrugation period of the corrugated groove structure is 5 - 8 mm, the wave amplitude is 1.2 - 1.8 mm, and the corrugation inclination angle is 45 ± 5°; A number of mounting holes are formed on the inner side of the rim body (1); the outer surface of the rim body (1) has an electroplated layer; The manufacturing process includes the following steps: S1, Using an eddy current heating device, heat the aluminum-magnesium alloy bar stock to soften it, and then use a hydraulic profile extruder. The pressure of the hydraulic profile extruder cooperates with the die to extrude the bar stock into a profile. The cross-sectional shape of the die cavity matches the final cross-sectional shape of the rim body, including a hollow structure that is wider at the top and narrower at the bottom, preformed grooves for buffer bands protruding inward on both sides, and a forming cavity for the top anti-bite wheel rim; S2, After the profile is extruded, directly carry out bending processing. Specifically: When the profile is in a high-temperature state of 380 - 450 °C, use the profiling roller group of a metal bending machine to carry out bending processing. The profile of the roller group matches the cross-sectional shape of the rim body. When bending, the wider part at the top faces outward, and through the control of the roller pressure, directional deformation is generated on the buffer band side; Bend the extruded profile into a spiral shape of 3 to 5 turns, and cut off the remaining profile; S3, Put the spiral profile into a cutting machine and perform cutting processing along the cross-sectional direction to form a number of annular rims with notches; S4, Cool the rim and cool it to room temperature; S5, Pickle the cooled rim to clean the impurities and contaminants on the surface and etch the surface at the same time; S6, Perform heat treatment on the rim processed in step S5, including solution treatment and aging treatment; S7, Weld the notches of the rim after heat treatment; S8, After welding is completed, perform milling processing to remove the weld beads generated by welding; S9, After removing the weld beads, perform electroplating processing to form a plating layer on the surface of the rim; S10, Drill holes evenly in the rim to open holes for installing spoke components and tire valves.

2. The manufacturing process of the bicycle rim according to claim 1, characterized in that: After cutting the remaining profiles in step S2, it further includes: clamping out the bent profiles by a manipulator, and the metal bending machine continues to perform the bending process on the next section of profiles.

3. The manufacturing process of the bicycle rim according to claim 1, characterized in that: The cutting process in step S3 specifically is: putting the spiral profiles into a cutting machine by a manipulator, and cutting all the turns of the profiles in one cut along the cross-sectional direction to form several annular rims with notches.

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