A carbon fiber barrel axle structure for a bicycle

Abstract

The utility model discloses a bicycle carbon fiber barrel axle rod structure and the bicycle with it relates to bicycle accessory field. This bicycle carbon fiber barrel axle rod structure includes axle rod body, fastener and connecting piece, and axle rod body is carbon fiber composite material spare, has the central hole of extending along the axial direction, and fastener is titanium alloy material spare, and fastener has the cooperation hole of extending along the axial direction in, and one end of axle rod body is fixed in at least partial cooperation hole, to make the coaxial communication of central hole and cooperation hole, and the common definition of fastening cavity, and the inside of connecting piece is equipped with the internal hexagon hole for connecting with external component, and wherein, the outer peripheral wall of connecting piece is fixedly connected with the hole wall of central hole and the hole wall of cooperation hole respectively. The bicycle carbon fiber barrel axle rod structure of utility model embodiment has lighter weight, and has higher rigidity and torque simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of bicycle accessories, and in particular to a bicycle carbon fiber stub shaft structure. Background Technology

[0002] Thru-axle is a connecting component used to fix bicycle wheelsets to the rear or front fork of the frame. It achieves a high-rigidity connection between the wheelset and the frame by inserting into the axle and locking it, thereby improving the handling stability and safety of the whole vehicle.

[0003] Currently, some thru-axles on the market are made of metal, which, while strong, is heavy and detrimental to overall vehicle weight reduction. To reduce weight, some manufacturers have introduced thru-axles made entirely of carbon fiber. While this is effective in reducing weight, the material and properties of carbon fiber make it impossible to manufacture high-strength threads and internal hexagonal joints. Therefore, the ends of the carbon fiber thru-axles are connected with titanium alloy.

[0004] Therefore, how to balance lightweight design and cost control in barrel shafts is one of the research directions of this application. Utility Model Content

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the first aspect of the present invention aims to provide a bicycle carbon fiber spool axle structure that is lightweight while possessing high rigidity and torque capacity.

[0006] The second aspect of this utility model is to provide a bicycle having the above-mentioned carbon fiber barrel axle structure.

[0007] According to a first aspect of the present invention, a bicycle carbon fiber cantilever shaft structure includes: a shaft body, a fastener, and a connector. The shaft body is made of carbon fiber composite material and has a central hole extending axially. The fastener is made of titanium alloy and has a mating hole extending axially. One end of the shaft body is fixed in at least a portion of the mating hole so that the central hole and the mating hole are coaxially connected and together define a fastening cavity. At least a portion of the connector is fixedly disposed in the fastening cavity, and the connector has an internal hexagonal hole for connecting to an external component. The outer peripheral wall of the connector is fixedly connected to the hole wall of the central hole and the hole wall of the mating hole, respectively.

[0008] According to the bicycle carbon fiber cantilever axle structure of this utility model embodiment, by using a lightweight and high-strength carbon fiber composite material for the axle body of the main part and integrating titanium alloy fasteners at the stress-bearing end, a combination of lightweight and high strength is achieved. Simultaneously, the central hole of the axle body and the mating hole of the fastener are coaxially connected, forming a continuous fastening cavity, allowing the connector to cross the interface between two materials and obtain a longer effective support length. This not only increases the depth of the internal hexagonal hole, improving the engagement reliability and operational safety of the internal hexagonal wrench, but also avoids the metal adhesion problem caused by long-term assembly in all-metal structures. The overall structure significantly optimizes overall weight and maintenance convenience while ensuring torsional stiffness, connection reliability, and durability.

[0009] In some alternative embodiments, the fastener includes a first end face located at one end of the axial direction; the connector includes a second end face located at one end along the axial direction; the bicycle carbon fiber cantilever shaft structure further includes: a welded layer; the side surface of the welded layer is welded to the first end face and the second end face, and the welded layer has a through hole for communicating with the internal hexagonal hole.

[0010] According to some other embodiments of the bicycle carbon fiber cantilever shaft structure, the fastening cavity includes: a first connecting chamber and a second connecting chamber connected in sequence, the first connecting chamber being formed at the end of the central hole of the shaft body; the second connecting chamber being formed at the end of the mating hole of the fastener; a portion of the connector is fitted in the first connecting chamber, and the remainder is fitted in the second connecting chamber.

[0011] Furthermore, the inner wall of the first connecting chamber is provided with a first internal thread; the inner wall of the second connecting chamber is provided with a second internal thread; the first internal thread and the second internal thread are continuously mated along the axial direction to form a continuous internal thread structure; the outer peripheral wall of the connector is provided with an external thread structure adapted to the internal thread structure.

[0012] Optionally, the outer diameter of the connector is larger than the inner diameter of the first connecting chamber and the inner diameter of the second connecting chamber, so that after press fitting, the outer peripheral wall of the connector forms an interference fit with the inner wall of the first connecting chamber and the inner wall of the second connecting chamber, respectively.

[0013] In some alternative embodiments, the bicycle carbon fiber cantilever shaft structure further includes: an adhesive layer; the adhesive layer is disposed around the outer peripheral wall of the connector and is adhesively bonded to the inner wall of the shaft body and the inner wall of the fastener, respectively.

[0014] According to some alternative embodiments of the present invention, the outer peripheral wall of the shaft body for cooperating with the fastener is provided with a first anti-slip texture; the outer peripheral wall of the fastener for cooperating with the shaft body is provided with a second anti-slip texture adapted to the first anti-slip texture.

[0015] Optionally, the shaft body and the fastener are an integrated structural component.

[0016] Alternatively, the outer peripheral wall of the mating area between the shaft body and the fastener along the axial direction is coplanar and smoothly transitions.

[0017] A bicycle according to a second aspect of the present invention includes: a frame, a wheelset, and a carbon fiber thru-axle. The frame includes fork legs with mounting holes. The wheelset has an axle hole. The carbon fiber thru-axle passes through the mounting hole and the axle hole, and is detachably fixed to the frame by the wheelset. Here, the carbon fiber thru-axle is the type described in the first aspect of the present invention.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a cross-sectional view of the bicycle carbon fiber barrel axle structure in some embodiments of this utility model; Figure 2 This is a perspective view of the bicycle carbon fiber cantilever shaft structure in some embodiments of the present invention; Figure 3 This is a partial schematic diagram of the bicycle carbon fiber barrel axle structure in some embodiments of the present invention; Figure 4 This is an exploded view of a portion of the carbon fiber barrel axle structure of a bicycle in some embodiments of this utility model.

[0020] Figure label: 100 carbon fiber spool shaft structure for bicycles Shaft body 10, center hole 11, first internal thread 12, first anti-slip texture 13 Fastener 20, mating hole 21, first end face s1, second internal thread 22, second anti-slip texture 23 Connector 30, internal hexagonal hole 31, second end face s2, external thread structure 32 Weld layer 40, through hole 41 Fastening cavity t, first connecting chamber t1, second connecting chamber t2. Detailed Implementation

[0021] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0022] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model 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 utility model. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] The following is for reference. Figures 1-4 A bicycle carbon fiber cantilever shaft structure 100 according to a first aspect embodiment of the present invention is described.

[0025] like Figure 1 , Figure 2 and Figure 4 As shown, the bicycle carbon fiber cantilever axle structure 100 according to an embodiment of the present invention includes: an axle body 10, a fastener 20, and a connector 30. The axle body 10 is a carbon fiber composite material component and has a central hole 11 extending axially.

[0026] It is worth noting that in the bicycle carbon fiber thru-axle structure 100, the axle body 10 constitutes the main part, extending axially and occupying the main length of the bicycle carbon fiber thru-axle structure 100, while the fastener 20 is only set at one end of the axle body 10, used to achieve local reinforcement and connection functions. Therefore, the axle body 10 is a carbon fiber composite material component, which significantly reduces the overall weight while ensuring sufficient rigidity and strength, thereby effectively achieving the lightweighting of the thru-axle structure 100, which is beneficial to improving the handling performance and riding efficiency of the bicycle.

[0027] Some traditional thru-axles are made entirely of metal, resulting in a high overall weight, often reaching 60g. In contrast, the carbon fiber thru-axle structure 100 of this invention significantly reduces the overall weight to 30g by using carbon fiber composite materials for the axle body 10, while maintaining structural strength and rigidity. Compared to other methods, the thru-axle structure 100 of this invention reduces its weight by approximately 50%, effectively achieving the goal of lightweight design.

[0028] In addition, some traditional all-metal thru-axles, after being installed on the frame, have their metal surfaces in close contact with the frame or other metal components (such as hubs and nuts) for extended periods. If not disassembled for a long time, especially under humid or high-load conditions, metal adhesion can easily occur, making disassembly difficult and requiring the use of impact tools for forced separation, which carries the risk of damaging the frame or wheelset. In this embodiment, the axle body made of carbon fiber composite material is used to directly contact the frame, hubs, or nuts. Since carbon fiber is a non-metallic material, there is no metal-to-metal contact at this interface, thus avoiding the metal adhesion problem caused by long-term assembly, improving disassembly convenience and maintenance reliability.

[0029] The fastener 20 is located at one end of the shaft body 10 and is used to connect the main stress-bearing area of ​​the overall structure—namely, the connector 30. To improve the torsional strength and connection reliability of the main stress-bearing area, in this embodiment, the fastener 20 is made of titanium alloy.

[0030] Because titanium alloy has high strength and rigidity, fasteners 20 made of this material can effectively improve the overall torsional resistance of the barrel shaft.

[0031] The fasteners 20 made of titanium alloy also have high corrosion resistance, which helps to extend the overall service life. This also helps to further reduce the weight of local structures. Applying them to the carbon fiber swivel shaft structure 100 of bicycles not only helps to achieve overall structural lightweighting but also significantly improves the reliability and durability of the end connection area.

[0032] Thus, in the bicycle carbon fiber cantilever shaft structure 100 of this embodiment, the shaft body 10 of the main part is made of carbon fiber composite material, while the fasteners 20 of the local connection area are made of titanium alloy. By adopting a composite structure, the overall weight is reduced while taking into account the structural rigidity and torsional performance.

[0033] It should be noted that the connection between the carbon fiber composite shaft body 10 and the titanium alloy fastener 20 can adopt conventional methods in the prior art. Since this connection method is not the core innovation of this application, it will not be described in detail here.

[0034] The fastener 20 has an axially extending mating hole 21, and one end of the shaft body 10 is fixed in at least part of the mating hole 21 so that the center hole 11 and the mating hole 21 are coaxially connected and together define the fastening cavity t.

[0035] By fixing the shaft body 10 in the partial mating hole 21 of the fastener 20 and ensuring that the center hole 11 is coaxially aligned with the mating hole 21, stress concentration or loosening of the connection due to eccentricity or misalignment can be effectively avoided. This coaxial connection structure provides a stable reference for the subsequent installation of the connector 30, which is beneficial to ensuring reliable docking between the barrel shaft structure 100 and the frame or hub.

[0036] The fastening cavity t formed by the central hole 11 and the mating hole 21 spans the interface between the two materials of the shaft body 10 and the fastener 20, allowing the connector 30 to contact both at the same time and form a fixed connection.

[0037] It can be seen that by constructing a fastening cavity t together in the central hole 11 and the mating hole 21, the axial length of the fastening cavity t can be extended, thereby increasing the support length of the connector 30, thus improving the stability and torque transmission capability of the connector 30.

[0038] At least a portion of the connector 30 is fixedly disposed within the fastening cavity t, and the connector 30 has an internal hexagonal hole 31 for connection with external components. The outer peripheral wall of the connector 30 is fixedly connected to the wall of the central hole 11 and the wall of the mating hole 21, respectively.

[0039] The external component here is an Allen wrench. When it is necessary to install or remove the bicycle carbon fiber spool rod structure 100, the end of the Allen wrench can be inserted into the Allen hole 31 of the connector 30, and torque can be applied to lock or release the spool rod and nut.

[0040] In the above technical solution, the internal hexagonal hole 31 is integrated into the connector 30 inside the fastening cavity t, so that the operation interface is completely embedded, avoiding exposed protrusions and improving the uniformity of appearance.

[0041] Furthermore, since the fastening cavity t is formed by the mating hole 21 and the center hole 11, spanning both the fastener 20 and the shaft body 10, its overall length is effectively extended. Therefore, the connector 30 can be designed to be longer, and correspondingly, the depth of the hexagonal socket 31 can also be increased. This allows the hexagonal wrench to be inserted deeper during use, forming a more complete engagement with the hexagonal socket 31, which not only improves the reliability of torque transmission but also reduces the risk of slippage or tool dislodgement.

[0042] The outer peripheral wall of the connector 30 is fixedly connected to the wall of the central hole 11 and the wall of the mating hole 21, respectively. When transmitting the torque of the wrench, the load can be distributed throughout the entire fastening cavity t, preventing local stress concentration or loosening of the connection. This ensures the convenience and reliability of installation / disassembly operations.

[0043] Optionally, the fixed connection between the connector 30 and the wall of the center hole 11 and the wall of the mating hole 21 can be any one or more combinations of threaded fit, interference fit, and adhesive fit.

[0044] In summary, the bicycle carbon fiber cantilever axle structure 100 according to this utility model embodiment achieves a combination of lightweight and high strength by using a lightweight, high-strength carbon fiber composite material for the axle body 10 of the main body and integrating a titanium alloy fastener 20 at the load-bearing end. Simultaneously, the central hole 11 of the axle body 10 and the mating hole 21 of the fastener 20 are coaxially connected, forming a continuous fastening cavity t, allowing the connector 30 to cross the interface between two materials and obtain a longer effective support length. This not only increases the depth of the internal hexagonal hole 31, improving the engagement reliability and operational safety of the internal hexagonal wrench, but also avoids the metal adhesion problem caused by long-term assembly in all-metal structures. The overall structure significantly optimizes weight and maintenance convenience while ensuring torsional stiffness, connection reliability, and durability.

[0045] In some alternative embodiments, such as Figure 3 As shown, the fastener 20 includes a first end face s1 located at one end in the axial direction. The connector 30 includes a second end face s2 located at one end in the axial direction.

[0046] Specifically, after the fastener 20 and the connector 30 are assembled, the first end face s1 and the second end face s2 are located on the same end side of the barrel shaft structure 100 and are flush with each other, forming a flat end profile.

[0047] The bicycle carbon fiber cantilever shaft structure 100 also includes a welding layer 40. The side surface of the welding layer 40 is welded to the first end face s1 and the second end face s2, and the welding layer 40 has a through hole 41 for connecting the internal hexagonal hole 31.

[0048] In the above technical solution, the welding layer 40 covers the outer side of the first end face s1 of the fastener 20 and the second end face s2 of the connector 30, and is fixedly connected to these two end faces by welding.

[0049] The fastener 20 and the connector 30 are firmly connected at the end by the weld layer 40, effectively suppressing the relative rotation tendency of the two under torque. At the same time, the continuous metal structure formed by welding enhances the overall rigidity of the end area, thereby improving the torsional performance of the bicycle carbon fiber toggle shaft structure 100.

[0050] Since the first end face s1 and the second end face s2 are flush after assembly, the welding layer 40 can evenly fit the entire end area, forming a strong and well-sealed connection, effectively ensuring the connection strength and overall torsional resistance of the structure.

[0051] In some specific examples, the torque of the barrel shaft without the added weld layer is 6N, while after adding a 0.5mm weld layer, the overall torque can reach 30N.

[0052] Meanwhile, the continuous and flat end surfaces and high consistency in appearance help improve the overall neatness of the bicycle after assembly.

[0053] In addition, the weld layer 40 is provided with a through hole 41, which is coaxially aligned and connected with the internal hexagonal hole 31 inside the connector 30. Specifically, the shape and size of the through hole 41 are adapted to the shape and size of the internal hexagonal hole 31, so that the internal hexagonal wrench can be smoothly inserted into the internal hexagonal hole 31 through the weld layer 40 to realize the installation or disassembly operation without affecting the normal intervention of the tool.

[0054] According to another embodiment of the bicycle carbon fiber stub shaft structure 100, combined with Figure 1 and Figure 3 The fastening cavity t includes, in sequence, a first connecting chamber t1 and a second connecting chamber t2. The first connecting chamber t1 is formed at the end of the central hole 11 of the shaft body 10. The second connecting chamber t2 is formed at the end of the mating hole 21 of the fastener 20. A portion of the connector 30 fits into the first connecting chamber t1, and the remainder fits into the second connecting chamber t2.

[0055] The connector 30 spans the interface between the carbon fiber shaft body 10 and the metal fastener 20, and is embedded in both chambers, increasing its effective support length and contact area, thereby improving the stability of torque transmission and its resistance to loosening.

[0056] By mates of connector 30 with chambers of different materials, the fixing methods between different chambers and connector 30 can also be different.

[0057] In some embodiments, the first connecting chamber t1 and the second connecting chamber t2 are fixed in the same way as the connector 30. For example, the connector 30 is connected by one or more of the following mating methods: threaded fit, interference fit, or adhesive fit, and at the same time, it achieves a consistent connection with the wall of the central hole 11 and the wall of the mating hole 21.

[0058] In some other embodiments, the first connecting chamber t1 and the second connecting chamber t2 may be fixed to the connector 30 in different ways to adapt to the structural characteristics of different materials.

[0059] For example, since the second connecting chamber t2 is located within the fastener 20 of the metal component, a threaded connection or interference fit can be used to obtain higher load-bearing capacity and torsional stiffness. The first connecting chamber t1 is located within the carbon fiber composite shaft body 10 and can be fixed using an interference fit.

[0060] During assembly, the connector 30 can be screwed into the second connecting chamber t2 located within the fastener 20 to complete preliminary mechanical positioning and pre-tightening. Then, the connector 30 is further screwed axially into the center hole 11 of the shaft body 10, allowing it to enter the first connecting chamber t1. The inner diameter of the first connecting chamber t1 can be slightly smaller than the inner diameter of the second connecting chamber t2, thereby forming a suitable interference fit in the mating area.

[0061] In some specific embodiments, the inner wall of the first connecting chamber t1 is provided with a first internal thread 12. The inner wall of the second connecting chamber t2 is provided with a second internal thread 22. The first internal thread 12 and the second internal thread 22 are continuously mated along the axial direction to form a continuous internal thread structure. The outer peripheral wall of the connector 30 is provided with an external thread structure 32 adapted to the internal thread structure.

[0062] In the above embodiments, since the internal thread structure spans the shaft body 10 and the fastener 20 and remains continuous, the connector 30 can simultaneously form a reliable thread engagement with both parts during screwing in, simplifying the assembly operation and improving the overall integrity and torsional stiffness of the connection. In addition, the continuous thread structure effectively avoids stress concentration caused by thread interruption or misalignment, enhancing the structural stability and durability of the barrel shaft under high load conditions.

[0063] Here, "the first internal thread 12 and the second internal thread 22 are continuously connected along the axial direction to form a continuous internal thread structure" means that the first internal thread 12 and the second internal thread 22 have the same thread type, direction of rotation, pitch and tooth angle, and at the joint of the two (i.e. the interface between the shaft body 10 and the fastener 20), the thread crest, root and helix are smoothly connected in the axial direction without misalignment, steps and gaps, so that the external thread on the connector 30 can continuously mesh with the entire internal thread structure during the screwing process, just like cooperating with a single, integral threaded hole, thereby achieving smooth assembly and uniform load transmission.

[0064] In actual manufacturing, the shaft body 10 and fastener 20 can be fixedly assembled first, and then threading processes such as integral tapping or precision turning can be used to continuously machine internal threads on the inner walls of both in one go, thereby ensuring a smooth connection of the threads at the mating interface. Alternatively, locating pins, keyways, or other circumferential positioning structures can be provided on the mating end faces of the fastener 20 and the shaft body 10 to maintain precise angular alignment after assembly, thereby ensuring that the first internal thread 12 and the second internal thread 22, which are machined separately, are in phase when mated, forming a continuous thread structure.

[0065] Optionally, the outer diameter of the connector 30 is larger than the inner diameter of the first connecting chamber t1 and the inner diameter of the second connecting chamber t2, so that after press fitting, the outer peripheral wall of the connector 30 forms an interference fit with the inner wall of the first connecting chamber t1 and the inner wall of the second connecting chamber t2, respectively.

[0066] The connector 30 is tightly fitted with the shaft body 10 and the fastener 20 through radial compressive stress, which simplifies the structure and improves assembly efficiency.

[0067] Furthermore, since the interference fit is continuously distributed along the entire length of the fastening cavity t, the load can be evenly transferred to both the carbon fiber shaft body 10 and the metal fastener 20, effectively avoiding local stress concentration and improving the overall torsional stiffness and fatigue durability.

[0068] It should be noted that although the first connecting chamber t1 is located within the carbon fiber composite component, controlling the interference fit within the range of 0.01–0.05 mm can prevent cracking or fiber damage. Furthermore, the outer peripheral wall of the connector 30 is provided with rounded corners and a surface polishing layer, which can effectively reduce stress concentration during assembly, thereby improving the assembly efficiency of the interference fit.

[0069] The second connecting chamber t2 is located in the metal fastener 20 and can withstand a larger interference fit, further enhancing the connection strength.

[0070] In some optional embodiments, the inner diameters of the first connecting chamber t1 and the second connecting chamber t2 can be the same. In actual manufacturing, the shaft body 10 can be fixedly assembled with the fastener 20 first, and then machining processes such as integral boring, reaming, or internal grinding can be used to continuously machine mating inner holes with consistent diameters and high coaxiality on the inner walls of both, thereby providing a uniform and continuous mating surface for the subsequent installation of the connecting piece 30.

[0071] Alternatively, the inner diameter of the first connecting chamber t1 can be slightly larger than the inner diameter of the second connecting chamber t2. In actual manufacturing, the ends of the central hole 11 of the shaft body 10 and the mating hole 21 of the fastener 20 can be machined independently to form their respective required inner diameters. Subsequently, the shaft body 10 and the fastener 20 are fixedly connected as a single unit, thereby forming a fastening cavity t with a stepped inner hole structure.

[0072] In some alternative embodiments, the bicycle carbon fiber cantilever axle structure 100 further includes an adhesive layer (not shown). The adhesive layer is disposed around the outer peripheral wall of the connector 30 and is adhesively bonded to the inner wall of the axle body 10 and the inner wall of the fastener 20, respectively.

[0073] In the above technical solution, the adhesive layer is arranged on the outer peripheral wall of the connector 30 and is bonded to the inner wall of the shaft body 10 and the inner wall of the fastener 20 respectively. The connector 30 forms a uniform and continuous stress transmission path between the shaft body 10 and the fastener 20, effectively improving the integrity, torsional resistance and fatigue durability of the connection.

[0074] It should be noted that "circumferential arrangement" here refers to the circumferential arrangement of the adhesive layer along the outer peripheral wall of the connector 30.

[0075] In some technical solutions, the adhesive layer is a continuous annular structure. Specifically, the adhesive layer continuously covers the outer periphery of the connector 30 along the entire circumference, thereby providing a uniform bonding interface and full-circumferential load transfer capability.

[0076] In other technical solutions, the adhesive layer can also be arranged in segments. Specifically, the adhesive layer consists of multiple circumferentially spaced adhesive regions. For example, they can be dotted, arc-shaped, or axially striped. This ensures sufficient adhesive strength while facilitating adhesive air release and controlling the adhesive layer thickness.

[0077] According to some alternative embodiments of the present invention, in combination with Figure 1 and Figure 3 The outer peripheral wall of the shaft body 10, which is used to mate with the fastener 20, is provided with a first anti-slip texture 13. The outer peripheral wall of the fastener 20, which is used to mate with the shaft body 10, is provided with a second anti-slip texture 23 that matches the first anti-slip texture 13.

[0078] Anti-slip textures can include axial grooves, spiral patterns, knurling, serrated protrusions, etc.

[0079] During assembly, a first anti-slip texture 13 is pre-machined on the outer wall surface of the fastener 20 of the metal component. Then, carbon fiber cloth is wrapped around the outer wall of the fastener 20 with the first anti-slip texture 13. After high-temperature curing, the carbon fiber composite material replicates its texture on the surface of the fastener 20, thereby forming a second anti-slip texture 23 on the inner wall of the shaft body 10 that interlocks with the first anti-slip texture 13. Thus, the shaft body 10 and the fastener 20 achieve circumferential locking through the positively engaging anti-slip texture structure, further enhancing their torsional transmission capacity and interfacial bonding strength.

[0080] Optionally, the shaft body 10 and the fastener 20 are structurally integrated.

[0081] Specifically, one or more layers of carbon fiber cloth can be wrapped around the outer wall of the metal fastener 20, and then cured at high temperature to form the carbon fiber composite material in situ on the surface of the fastener 20 as the shaft body 10. Thus, the shaft body 10 and the fastener 20 are directly integrated during the manufacturing process, forming a structurally integrated component that does not require subsequent assembly.

[0082] Compared to traditional adhesive or mechanical connections, this integrated structure eliminates the need for additional fastening components or bonding interfaces. This not only simplifies the assembly process but also fundamentally avoids problems such as loosening of connections, interface debonding, or strength reduction caused by long-term use, vibration, or environmental aging. It significantly improves the overall structural reliability, torsional stiffness, and durability of the barrel shaft.

[0083] Alternatively, the outer peripheral walls of the mating areas of the shaft body 10 and the fastener 20 along the axial direction are coplanar and smoothly transition.

[0084] In the above technical solution, the outer peripheral wall of the mating area of ​​the shaft body 10 and the fastener 20 along the axial direction together form a continuous, stepless outer contour.

[0085] In this way, when the thru-axle is inserted into the mounting hole of the bicycle front or rear fork, the smooth outer surface can avoid assembly resistance or scratches to the inner wall of the frame caused by local protrusions or sharp edges.

[0086] Meanwhile, when subjected to lateral impacts, braking reaction forces, or driving torques during riding, the continuity of the outer contour helps to distribute the load evenly along the axial direction, reduce stress concentration, improve structural fatigue life, and ensure the tight fit and connection stability between the thru-axle and the frame.

[0087] A bicycle according to a second aspect of the present invention includes: a frame, wheelset, and a bicycle carbon fiber thru-axle structure 100. Here, the bicycle carbon fiber thru-axle structure 100 adopts the bicycle carbon fiber thru-axle structure 100 of the first aspect of the present invention.

[0088] It is worth noting that the bicycles in this application embodiment may include various types, such as mountain bikes, road bikes, gravel road bikes, urban commuter bikes, electric-assisted bicycles, folding bicycles, or unicycles.

[0089] By adopting a lightweight, high-rigidity, and high-torque carbon fiber tube axle structure, the overall weight of the bicycle is reduced, and it still maintains high reliability after multiple disassembly and assembly, thus improving the bicycle's durability.

[0090] The frame includes fork legs with mounting holes. The wheelset has axle holes; the bicycle carbon fiber thru-axle structure 100 passes through the mounting holes and axle holes to detachably fix the wheelset to the frame.

[0091] This design allows for quick and secure mounting of the wheelset to the frame, while ensuring a reliable and secure connection during riding. Furthermore, the lightweight and rigid axle body contributes to a reduction in the overall bike weight.

[0092] In this specification, the terms "embodiment," "example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0093] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A carbon fiber stub shaft structure (100) for bicycles, characterized in that, include: The shaft body (10) is a carbon fiber composite material and has a central hole (11) extending along the axial direction. The fastener (20) is made of titanium alloy and has a mating hole (21) extending axially. One end of the shaft body (10) is fixed in at least part of the mating hole (21) so that the center hole (11) and the mating hole (21) are coaxially connected and together define the fastening cavity (t). A connector (30) is fixedly disposed in the fastening cavity (t) at least part of which is provided inside the connector (30) for connecting with external components; The outer peripheral wall of the connector (30) is fixedly connected to the wall of the central hole (11) and the wall of the mating hole (21).

2. The bicycle carbon fiber cantilever shaft structure (100) according to claim 1, characterized in that, The fastener (20) includes a first end face (s1) located at one end of the axial direction; The connector (30) includes a second end face (s2) located at one end along the axial direction; The bicycle carbon fiber barrel axle structure (100) also includes: a welded layer (40). The side surface of the welding layer (40) is welded to the first end face (s1) and the second end face (s2), and a through hole (41) for connecting the internal hexagonal hole (31) is provided on the welding layer (40).

3. The bicycle carbon fiber spool shaft structure (100) according to claim 1, characterized in that, The fastening cavity (t) comprises the following components connected in sequence: The first connecting chamber (t1) is formed at the end of the central hole (11) of the shaft body (10); The second connecting chamber (t2) is formed at the end of the mating hole (21) of the fastener (20); A portion of the connector (30) fits into the first connecting chamber (t1), and the remainder fits into the second connecting chamber (t2).

4. The bicycle carbon fiber spool shaft structure (100) according to claim 3, characterized in that, The inner wall of the first connecting chamber (t1) is provided with a first internal thread (12); The inner wall of the second connecting chamber (t2) is provided with a second internal thread (22); The first internal thread (12) and the second internal thread (22) are continuously connected along the axial direction to form a continuous internal thread structure; The outer peripheral wall of the connector (30) is provided with an external thread structure (32) that is adapted to the internal thread structure.

5. The bicycle carbon fiber spool shaft structure (100) according to claim 3, characterized in that, The outer diameter of the connector (30) is larger than the inner diameter of the first connecting chamber (t1) and the inner diameter of the second connecting chamber (t2), so that after the connector (30) is press-fitted, the outer peripheral wall of the connector (30) forms an interference fit with the inner wall of the first connecting chamber (t1) and the inner wall of the second connecting chamber (t2).

6. The bicycle carbon fiber spool shaft structure (100) according to claim 1, characterized in that, Also includes: Adhesive layer; The adhesive layer is arranged in a ring around the outer peripheral wall of the connector (30) and is adhesively connected to the inner wall of the shaft body (10) and the inner wall of the fastener (20).

7. The bicycle carbon fiber spool axle structure (100) according to any one of claims 1-6, characterized in that, The outer peripheral wall of the shaft body (10) for cooperating with the fastener (20) is provided with a first anti-slip texture (13). The fastener (20) has a second anti-slip texture (23) on its outer peripheral wall that is adapted to the first anti-slip texture (13) for cooperating with the shaft body (10).

8. The bicycle carbon fiber spool shaft structure (100) according to claim 7, characterized in that, The shaft body (10) and the fastener (20) are structurally integrated.

9. The bicycle carbon fiber spool shaft structure (100) according to claim 7, characterized in that, The outer peripheral walls of the mating area of ​​the shaft body (10) and the fastener (20) along the axial direction are coplanar and smoothly transition.

10. A bicycle, characterized in that, include: A frame, the frame including forks, the forks being provided with mounting holes; Wheel assembly, the wheel assembly having an axle hole; The bicycle carbon fiber thru-axle as described in any one of claims 1-9, wherein the bicycle carbon fiber thru-axle passes through the mounting hole and the axle hole, and is detachably fixed to the frame by the wheelset.

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