Carbon fiber bicycle rim

Abstract

The utility model discloses a carbon fiber bicycle wheel rim which comprises an annular wheel rim body, the wheel rim body is integrally formed by carbon fibers, the wheel rim body comprises an outer ring wall, an inner ring wall and two side walls connecting the outer ring wall and the inner ring wall, a semi-closed tire groove is formed in the outer side of the outer ring wall, and the outer side of the tire groove is connected with the inner ring wall. A closed cavity is defined by the inner side of the outer ring wall, the inner ring wall and the side wall, a connecting part is arranged in the cavity, one end of the connecting part is connected with the outer ring wall, the other end of the connecting part is connected with the side wall, and a hollow channel is defined by the connecting part, the outer ring wall and the side wall. According to the carbon fiber bicycle rim, the hollow channel is formed between the outer ring wall and the side wall of the carbon fiber bicycle rim through the arrangement of the connecting parts, the weight of carbon fibers is basically unchanged, but the strength and the impact resistance of the carbon fibers are effectively improved, the relation between the weight and the strength of the carbon fiber bicycle rim is well balanced, and the service life of the carbon fiber bicycle rim is prolonged. And the overall performance of the rim is effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of carbon fiber products, in particular to a carbon fiber bicycle rim. Background Art

[0002] Carbon fiber not only has the inherent intrinsic properties of carbon materials, but also has the softness and processability of textile fibers. Its specific gravity is less than 1 / 4 of that of steel, but its strength is very strong and has been widely used. Carbon fiber bicycles have become mainstream racing bicycles with their excellent performance such as light weight and high strength. Among them, the rims of carbon fiber bicycles are made of carbon fiber. Weight reduction and reinforcement have always been its main research and development directions. However, weight reduction usually requires making them thinner and smaller, while reinforcement usually requires making them thicker and larger. There are contradictions between the two. Therefore, there is currently no carbon fiber bicycle rim on the market that can achieve both weight reduction and reinforcement.

[0003] In view of this, the inventor of the present application invented a carbon fiber bicycle rim. Utility Model Content

[0004] The utility model aims to provide a carbon fiber bicycle wheel rim with substantially unchanged weight but effectively improved strength.

[0005] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a carbon fiber bicycle rim, comprising an annular rim body, the rim body is integrally formed from carbon fiber, the rim body comprises an outer annular wall, an inner annular wall, and two side walls connecting the outer annular wall and the inner annular wall, the outer side of the outer annular wall forms a semi-closed tire groove, the inner side of the outer annular wall is surrounded by the inner annular wall and the side walls to form a closed cavity, a connecting part is provided in the cavity, one end of the connecting part is connected to the outer annular wall, and the other end is connected to the side wall, the connecting part and the outer annular wall and the side walls are surrounded to form a hollow channel.

[0006] Furthermore, the connecting parts are connected between the two side walls and the outer ring wall.

[0007] Furthermore, the inner diameter of the hollow channel is 2-6 mm.

[0008] Furthermore, the hollow channel is arranged in a ring shape along the rim body.

[0009] Furthermore, the hollow channel is predetermined by a preformed strip embedded in the rim body.

[0010] Furthermore, the connecting portion is provided with a clearance notch connecting the cavity and the hollow channel, and the end of the preformed strip is correspondingly exposed to the clearance notch.

[0011] Furthermore, the thermal expansion coefficient of the preform is 5×10 -4~8.0x10 -4 / ℃.

[0012] Furthermore, the inner annular wall and / or the outer annular wall is provided with a communicating hole communicating with the cavity, and the preformed strip is drawn out from the clearance notch through the communicating hole.

[0013] Furthermore, the communicating hole is a spoke assembly hole.

[0014] After adopting the above technical solution, the utility model has the following advantages compared with the prior art:

[0015] The carbon fiber bicycle rim of the utility model forms a hollow channel between the outer ring wall and the side wall of the carbon fiber bicycle rim by arranging a connecting portion. The weight of the carbon fiber remains basically unchanged, but its strength, especially the impact resistance, is effectively improved. The relationship between the weight and the strength of the carbon fiber bicycle rim is well balanced, so that the overall performance of the rim is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a three-dimensional diagram of the carbon fiber bicycle wheel rim of the utility model;

[0017] Figure 2 This is a schematic diagram of the structure of a carbon fiber bicycle wheel rim of the utility model;

[0018] Figure 3 It is a partial cross-sectional view of the notch of the carbon fiber bicycle wheel rim of the utility model;

[0019] Figure 4 This is a schematic diagram of the utility model of preforming strips to preform a carbon fiber bicycle rim.

[0020] Description of reference numerals:

[0021] 10- wheel rim body,

[0022] 11-outer annular wall, 111-extension portion, 112-tire groove,

[0023] 12- Inner ring wall,

[0024] 13- Side wall,

[0025] 14- Cavity,

[0026] 15-connecting part, 151-relief gap,

[0027] 16-Hollow channel,

[0028] 20-Preformed strips,

[0029] 30-Isolation film. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0031] It should be noted that in the present invention, the terms "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element of the present invention must have a specific orientation, and therefore cannot be understood as a limitation on the present invention. Example

[0032] Cooperate Figures 1 to 4 As shown, the utility model discloses a carbon fiber bicycle rim, which has a substantially unchanged weight compared with carbon fiber bicycle rims of the same specification, but has a higher strength, especially better impact resistance and is more stable.

[0033] Cooperate Figures 1 to 4 As shown, a carbon fiber bicycle rim includes a ring-shaped rim body 10, which is integrally formed from carbon fiber. The rim body 10 includes an outer ring wall 11, an inner ring wall 12, and two side walls 13 connecting the outer ring wall 11 and the inner ring wall 12. The outer side of the outer ring wall 11 forms a semi-closed tire groove 112, and the inner side of the outer ring wall 11, the inner side of the inner ring wall 12 and the side wall 13 form a closed cavity 14. A connecting portion 15 is provided in the cavity 14, and one end of the connecting portion 15 is connected to the outer ring wall 11, and the other end is connected to the side wall 13. The connecting portion 15, the outer ring wall 11 and the side wall 13 form a hollow channel 16.

[0034] The entire wheel rim is integrally formed of carbon fiber and is annular in shape. The outer ring wall 11 is located on the outer ring of the wheel rim, and its two ends are extended outward to form an extension portion 111, which encloses a semi-enclosed tire groove 112 for installing a tire. The inner ring wall 12 is located on the inner ring of the wheel rim, and one end of the side wall 13 is connected to the outer ring wall 11, and the other end is connected to the inner ring wall 12. The arrangement of the two side walls 13 makes the outer ring wall 11, the inner ring wall 12, and the two side walls 13 finally enclose a cavity 14, which is arranged in an annular shape along the extension direction of the wheel rim. The inner ring wall 12 usually needs to be provided with spoke holes for installing spokes. Among them, the outer surface of the extension portion 111 or the outer surface of the extension portion 111 and part of the side wall 13 form the braking surface of the wheel rim.

[0035] When the wheel rim is in use, its outer ring wall 11 (where the tire is installed) is the main stress-bearing area. The connection portion 15 is provided to provide a certain support to the outer ring wall 11, so that its strength and impact resistance are effectively improved and the wheel rim is more stable. The hollow channel 16 is provided to effectively improve the strength of the wheel rim, especially the impact resistance, without increasing the weight of the entire wheel rim compared to existing wheel rims of the same specification. The relationship between weight and strength is well balanced, and the overall performance is effectively improved.

[0036] The connecting parts 15 are connected between the two side walls 13 and the outer ring wall 11. The two connecting parts 15 are basically symmetrically arranged, so that the impact resistance of the wheel rim in all directions is more balanced and stable.

[0037] The inner diameter of the hollow channel 16 is 2-6 mm. The hollow channel 16 is arranged at the connection between the outer annular wall 11 and the side wall 13. The inner diameter of the hollow channel 16 should not be too large, otherwise the length of the connecting portion 15 extending is too long, which requires more carbon fiber materials, resulting in an increase in the weight of the entire wheel rim and an increase in cost. In addition, when the wheel rim is in use, its outer annular wall 11 is the main stress-bearing area, and the length of the connecting portion 15 extending is too long, which has no obvious effect on the impact resistance of the entire wheel rim; the inner diameter of the hollow channel 16 should not be too small, otherwise either the connecting portion 15 is too short to improve the performance, or the corresponding wall thickness is too thick and the weight is too heavy. Preferably, the cross-sectional shape of the hollow channel 16 is circular, and its diameter is 3-5 mm.

[0038] The hollow channel 16 is arranged in an annular shape along the wheel rim body 10, so as to ensure that the performance of the entire wheel rim is consistent at all places, and it is also convenient to operate when producing and processing the wheel rim.

[0039] The hollow channel 16 is pre-formed by a preformed strip 20 embedded in the wheel rim body 10, and the thermal expansion coefficient of the preformed strip 20 is 5×10 -4 ~8.0x10 -4 / ℃. Preforming is performed through the preform strip 20, and the preform strip 20 enters the molding mold together with the product for molding. During the heating and pressurizing process of the product, the preform strip 20 provides support force to facilitate product molding. Therefore, the preform strip 20 needs to be able to provide support force and ensure that it can be pulled out after the product is molded. Preferably, the preform strip 20 has a slight elastic force and has a certain thermal expansion and contraction function. When heated and pressurized in the mold, its volume expands to a certain extent to facilitate product molding. After the product cools, the volume of the preform strip 20 can shrink to a certain extent, thereby facilitating its extraction from the hollow channel 16. In this embodiment, the material of the preform strip 20 is silicone.

[0040] Cooperate Figure 3As shown, the connecting portion 15 is provided with a clearance notch 151 connecting the cavity 14 and the hollow channel 16, and the end of the preform strip 20 is correspondingly exposed to the clearance notch 151. The end of the preform strip 20 is exposed in the cavity 14 at the position of the clearance notch 151. When the product is preformed, the carbon fiber prepreg is attached to the surface of the preform strip 20 to preform the hollow channel 16. During this process, the end of the preform strip 20 needs to be exposed without the carbon fiber prepreg attached. After the corresponding product is formed, a clearance notch 151 connecting the hollow channel 16 and the cavity 14 is formed, and the preform strip 20 is also pulled out from the hollow channel 16 through the clearance notch 151. The clearance notch 151 is provided to facilitate the subsequent extraction of the preformed strip 20. The length of the preformed strip 20 should not be too long, otherwise it will be inconvenient for the extraction of the preformed strip 20 and will increase the risk of breaking. Preferably, a hollow channel 16 is pre-formed by splicing two preformed strips 20 end to end, and the ends of the preformed strips 20 are exposed through the clearance notch 151, that is, one hollow channel 16 corresponds to two clearance notches 151.

[0041] The utility model also discloses a method for preparing a carbon fiber bicycle rim, which is used to prepare the above-mentioned carbon fiber bicycle rim, comprising the following steps:

[0042] S1: preparing a wheel rim preforming jig, a preforming strip 20 and cut carbon fiber prepreg.

[0043] The shape and size of the wheel rim preform jig are designed according to the shape and size of the wheel rim. The carbon fiber prepreg has been cut into multiple smaller sheet structures according to the shape of the wheel rim. The cut carbon fiber prepreg is attached and laid in the preform jig in sequence according to the designed attachment process, which can preform the shape of the wheel rim. Its shape and size are consistent with the final product. This process is an existing process and will not be elaborated here. The preform strip 20 is a component used to preform the hollow channel 16.

[0044] S2: Preform the corresponding carbon fiber prepreg layers in a preforming jig into a wheel rim shape, wherein the preform strip 20 is wrapped in the carbon fiber prepreg to preform a hollow channel 16, and the end of the preform strip 20 is reserved outside the hollow channel 16, and an air bag is inserted into the preformed cavity 14.

[0045] The preforming process of the rim by a preforming jig and inserting an air bag into the preformed cavity 14 is basically the same as the preforming process of the existing rim. The difference is that the process of the utility model requires the preforming strip 20 to be wrapped in a carbon fiber prepreg cloth so that its position corresponds to the preformed hollow channel 16.

[0046] The end of the preform strip 20 is reserved outside the hollow channel 16 so that the preform strip 20 can be pulled out of the hollow channel 16 through the end of the preform strip 20 after the product is formed, so as to reduce the overall weight of the rim.

[0047] In order to better extract the preform strip 20, the preform strip 20 is first coated with a layer of isolation film 30, and then the preform strip 20 and the isolation film 30 are coated together in the carbon fiber prepreg cloth, wherein the isolation film 30 is a PA film (nylon) or other suitable films, the thickness of the isolation film 30 is less than 0.05mm, and the weight is almost negligible (finally remaining in the hollow channel 16), but the isolation film 30 can effectively prevent the preform strip 20 from adhering to the wheel rim, thereby facilitating the extraction of the preform strip 20. Furthermore, the preform strip 20 is first coated with a layer of talcum powder, or other materials that can reduce friction, so as to further facilitate the extraction of the preform strip 20 from the isolation film 30.

[0048] In this embodiment, the preform strip 20 is made of silicone. Silicone has a certain elasticity and a certain ability to expand and contract with heat. In the environment where the mold is heated and pressurized, its volume expansion is more conducive to product molding. After the product is cooled, the volume of the silicone preform strip 20 shrinks to a certain extent, making it easier to be pulled out of the hollow channel 16.

[0049] In addition, in order to better extract the preform strip 20, a hollow channel 16 is pre-formed by splicing two preform strips 20 end to end, and both ends of the preform strip 20 are exposed in the cavity 14, and the position of the exposed end of the preform strip 20 corresponds to forming a clearance gap 151 connecting the cavity 14 and the hollow channel 16. That is, a hollow channel 16 has two clearance gaps 151, and the two preform strips 20 can be extracted from any one of the clearance gaps 151. Preferably, the two clearance gaps 151 are located on the same diameter of the rim.

[0050] S3: placing the preformed product into a molding die, heating and pressurizing it to form it. Placing the preformed product into the mold to form it is a prior art and will not be elaborated here.

[0051] S4: The product formed in the mold is taken out, a connecting hole communicating with the cavity 14 is processed, and the preform strip 20 is pulled out from the connecting hole.

[0052] After the product is formed, the air bag and the preform strip 20 need to be taken out. The method of taking out the air bag is a prior art and will not be described here. After the product is cooled, the preform strip 20 is taken out. At this time, a connecting hole connected to the cavity 14 needs to be processed on the wheel rim. Through the connecting hole, the preform strip 20 is pulled out from the hollow channel 16. Preferably, the connecting hole is a spoke assembly hole located on the outer ring wall 12 (the outer ring wall 11 and the inner ring wall 12 of the wheel rim body 10 both need to be processed with spoke assembly holes. The spoke assembly hole of the inner ring wall 12 is used for fitting and assembling with the spokes. The spoke assembly hole of the outer ring wall 11 is a channel for the nut. The nut enters the cavity and is assembled and fixed with the spoke. The spoke assembly hole of the outer ring wall 11 is usually larger than the spoke assembly hole of the inner ring wall 12). Such clever use of the existing structure eliminates the need to process additional connecting holes. One hole can be used for two purposes, thereby improving efficiency and reducing costs.

[0053] The above is only a preferred specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A carbon fiber bicycle rim, characterized in that: The invention comprises an annular wheel rim body, which is integrally formed from carbon fiber. The wheel rim body comprises an outer annular wall, an inner annular wall, and two side walls connecting the outer annular wall and the inner annular wall. The outer side of the outer annular wall forms a semi-closed tire groove, and the inner side of the outer annular wall is surrounded by the inner annular wall and the side walls to form a closed cavity. A connecting part is provided in the cavity, one end of the connecting part is connected to the outer annular wall, and the other end is connected to the side wall. The connecting part, the outer annular wall and the side walls are surrounded by a hollow channel.

2. A carbon fiber bicycle rim as claimed in claim 1, characterized in that: The connecting parts are connected between the two side walls and the outer ring wall.

3. A carbon fiber bicycle rim as claimed in claim 1, characterized in that: The inner diameter of the hollow channel is 2-6 mm.

4. A carbon fiber bicycle rim as claimed in claim 1, characterized in that: The hollow channel is arranged in an annular shape along the wheel rim body.

5. A carbon fiber bicycle rim as claimed in claim 1, characterized in that: The hollow channel is predetermined by a preformed strip embedded in the wheel rim body.

6. A carbon fiber bicycle rim as claimed in claim 5, characterized in that: The connecting portion is provided with a clearance notch connecting the cavity and the hollow channel, and the end of the preformed strip is correspondingly exposed to the clearance notch.

7. A carbon fiber bicycle rim as claimed in claim 5, characterized in that: The thermal expansion coefficient of the preform is 5×10 -4 ~8.0x10 -4 / ℃.

8. A carbon fiber bicycle rim as claimed in claim 6, characterized in that: The inner annular wall and / or the outer annular wall is provided with a communicating hole communicating with the cavity, and the preformed strip is drawn out from the clearance notch through the communicating hole.

9. A carbon fiber bicycle rim as claimed in claim 8, characterized in that: The communicating hole is a spoke assembly hole.

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