A method for manufacturing a carbon fiber vibration rod and a carbon fiber vibration rod

Abstract

The application discloses a kind of preparation method of carbon fiber vibration rod and carbon fiber vibration rod, belong to bladeless wind power generation technical field, the preparation method includes weaving, mould assembly, solidification, demolding and post-processing step, by optimizing the design of lay-up, and weaving, solidification process parameter, so that finished product can stabilize the required first-order bending natural frequency of recurrence.The carbon fiber vibration rod is single-cavity hollow cylindrical structure without reinforcing rib, and the wall thickness of the fixed section at both ends is greater than the wall thickness of the middle effective vibration section.The application has simple process, quantifiable production, realizes the accurate control of first-order bending natural frequency, and can flexibly adapt to the product demand of various application scenarios, and the finished vibration rod has no any internal reinforcing structure, has high lightweight degree, and has long service life.

Description

Technical Field

[0001] This invention belongs to the field of bladeless wind power generation technology, specifically relating to a method for preparing a carbon fiber vibrating rod and the carbon fiber vibrating rod itself. Background Technology

[0002] Bladeless wind power generation technology is a new type of clean energy utilization. Unlike traditional horizontal axis wind turbines, bladeless power generation equipment does not require rotating parts such as blades, gearboxes, and bearings. It has a simple structure, low maintenance costs, and minimal impact on the ecological environment, making it particularly suitable for distributed power generation and urban environments. It is based on the von Kármán vortex street principle. When wind blows over a slender rod-like structure, periodic vortices are generated on the leeward side of the rod, causing the rod to bend and resonate. The vibrational energy of this structure is then converted into electrical energy to generate electricity.

[0003] In bladeless wind turbines, the vibratory rod, as the core vibration transmission component, directly determines whether the equipment can achieve resonance locking with the wind force due to its first-order bending natural frequency, thus affecting power generation efficiency and stability. Carbon fiber composite materials, with their high specific stiffness, high specific strength, excellent fatigue performance, and lightweight characteristics, have become an ideal material for manufacturing vibratory rods for bladeless wind turbines.

[0004] The invention patent with publication number CN114731092A discloses an electric generator that uses vibration to achieve bladeless wind power generation, and mentions in the specification that carbon fiber can be used to make the capture element. However, regarding the manufacturing of the capture element, i.e., the vibrating rod, this patent only provides a conceptual technical solution and does not disclose various process parameters such as layup angle, curing temperature, pressure, and time. Therefore, those skilled in the art cannot know the manufacturing method of the capture element based on the disclosed content, cannot reproduce the first-order bending natural frequency that needs to be matched with the wind force and resonate with it, and cannot realize the industrial production of this product. Therefore, in the field of bladeless wind power generation technology, there is currently a lack of a carbon fiber vibrating rod manufacturing process and a carbon fiber vibrating rod that can control the first-order bending natural frequency and can be industrially mass-produced. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned shortcomings by providing a method for manufacturing a carbon fiber vibrating rod and a carbon fiber vibrating rod itself. This aims to solve the problem that current carbon fiber vibrating rods suffer from poor technical feasibility, making it difficult to control the first-order bending natural frequency and thus hindering industrial-scale mass production. To achieve the above objective, this invention provides the following technical solution: In a first aspect, the present invention provides a method for preparing a carbon fiber vibrating rod, comprising the following steps: Weaving steps: The carbon fiber material to be processed is mixed and woven according to the preset layup design ratio to form a preform; after weaving, OPP tape is used to wrap it to eliminate interlayer gaps; wherein, the weaving density is ≥95%, the weaving speed is 1.5m / h~2m / h, and the fiber tension is 5N~8N; the layup design includes one or more of 0° axial layup, ±45° oblique layup, and 90° circumferential layup; Mold assembly steps: Apply release agent evenly to the mold surface, and put the woven preform onto the mold; then use OPP tape to make the preform fit tightly with the mold; Curing step: The mold containing the preformed blank is heated and cured; the curing temperature is 110~140℃, the constant temperature curing time is 2h~3h, the heating rate is ≤2℃ / min, and the cooling rate is ≤2.5℃ / min. Demolding and post-processing steps: Demold after natural cooling to room temperature to obtain carbon fiber rods; grind both the inner and outer surfaces of the carbon fiber rods to make the outer surface roughness Ra≤1.6μm; then cut according to the preset rod length, and thicken the fixed sections at both ends of the carbon fiber rods to finally obtain the finished vibration rod.

[0006] Furthermore, the ply design is configured such that the 0° axial ply accounts for 60%~70%, the ±45° diagonal ply accounts for 30% in total, and the +45° ply and the -45° ply occupy the same number of layers; the 90° circumferential ply accounts for 0%~10%.

[0007] Furthermore, in the curing step, when the carbon fiber material has a standard modulus or a medium modulus, the curing temperature is 110℃~135℃; when the carbon fiber material has a high modulus, the curing temperature is 120℃~140℃.

[0008] Furthermore, in the demolding and post-processing steps, the fixed sections at both ends of the carbon fiber rod have the same thickness after thickening.

[0009] Furthermore, it also includes a testing step; the testing step specifically involves: after the cutting is completed, the carbon fiber rod is tested for parameters such as coaxiality, wall thickness tolerance, first-order bending natural frequency, and bending strength. If any one of these parameters fails to meet the preset testing conditions, the product is deemed unqualified and reworked.

[0010] In a second aspect, the present invention provides a carbon fiber vibrating rod, which employs the aforementioned preparation method and has the following specific structure: The vibrating rod is a hollow cylindrical structure with no internal reinforcing ribs, supporting ribs, or partitions.

[0011] Furthermore, the vibrating rod includes an effective vibrating section and two fixed sections; the two fixed sections are located at both ends of the effective vibrating section; the wall thickness of the fixed sections is greater than the wall thickness of the effective vibrating section.

[0012] Furthermore, the wall thickness of the fixed section is 11.5mm to 12.5mm.

[0013] Furthermore, the effective vibration section wall thickness is 6.5mm to 8.0mm.

[0014] Furthermore, the carbon fiber material is 24K carbon fiber.

[0015] The beneficial effects of this invention are: 1. By optimizing the layup design and weaving process parameters in the weaving step, this invention not only ensures the uniformity and density of the preform but also achieves precise control of the first-order bending natural frequency, stabilizing the first-order bending natural frequency of the finished product above 9Hz, thus solving the current problem of difficulty in controlling the first-order bending natural frequency.

[0016] 2. The preparation process of this invention is simple, highly feasible, and can be achieved using conventional equipment. It has good repeatability and adaptability to large-scale production. At the same time, by selecting different grades of carbon fiber materials and adjusting the corresponding process parameters, it can flexibly adapt to the cost and performance requirements of various application scenarios and realize the configuration of multiple solutions.

[0017] 3. The carbon fiber vibrating rod of the present invention has no internal reinforcing structure, is highly lightweight, and can avoid stress concentration while meeting the frequency required for resonance locking, thus improving service life. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the production process of the present invention; Detailed Implementation In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0019] In the description of this invention, "first feature" and "second feature" may include one or more of the features.

[0020] In the description of this invention, "a plurality of" means two or more.

[0021] In the description of this invention, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0022] In the description of this invention, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature.

[0023] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," and "some examples" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is 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.

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the following embodiments.

[0025] Example 1: See attached Figure 1 In a first aspect, this embodiment provides a method for preparing a carbon fiber vibrating rod, comprising the following steps: Weaving steps: The carbon fiber material to be processed is mixed and woven according to the preset layup design ratio to form a preform; after weaving, OPP tape is used to wrap it to eliminate interlayer gaps; wherein, the weaving density is ≥95%, the weaving speed is 1.5m / h~2m / h, and the fiber tension is 5N~8N; the layup design includes one or more of 0° axial layup, ±45° oblique layup, and 90° circumferential layup; Mold assembly steps: Apply release agent evenly to the mold surface, and put the woven preform onto the mold; then use OPP tape to make the preform fit tightly with the mold; Curing step: The mold containing the preformed blank is heated and cured; the curing temperature is 110~140℃, the constant temperature curing time is 2h~3h, the heating rate is ≤2℃ / min, and the cooling rate is ≤2.5℃ / min. Demolding and post-processing steps: Demold after natural cooling to room temperature to obtain carbon fiber rods; grind both the inner and outer surfaces of the carbon fiber rods to make the outer surface roughness Ra≤1.6μm; then cut according to the preset rod length, and thicken the fixed sections at both ends of the carbon fiber rods to finally obtain the finished vibration rod.

[0026] As can be seen from the above, the carbon fiber material referred to in this invention is a composite material composed of at least two materials: carbon fiber and epoxy resin. Epoxy resin serves as the matrix, used to bond the carbon fiber and transfer load, and ultimately, through a cross-linking reaction during the curing step, shapes the preform into the desired vibrating rod structure. Specifically, in this invention, the carbon fiber volume content is ≥70%.

[0027] In the weaving step, conventional three-dimensional weaving equipment can be used for weaving at a speed of 1.5m / h to 2m / h, with fiber tension controlled at 5N to 8N and weaving density controlled at over 95%. This ensures that the fibers are evenly and densely arranged in the preform, and that the weaving is uniform, without broken fibers or missing fibers, providing a good foundation for subsequent curing and avoiding problems such as uneven fiber arrangement or broken fibers caused by excessive weaving speed or excessive tension. After weaving, OPP tape is used to wrap the preform. The OPP tape can effectively compact the fiber layers, expel interlayer air, eliminate interlayer gaps, and ensure that each layup is tightly bonded.

[0028] Regarding the ply design, it includes one or more of 0° axial ply, ±45° diagonal ply, and 90° circumferential ply. The 0° axial ply primarily provides longitudinal stiffness to the preform made of carbon fiber, determining the bending natural frequency and bending strength of the vibrating rod. The ±45° diagonal ply provides torsional stiffness and shear strength to the preform, helping to resist torsional deformation during vibration and facilitating the uniform transfer of stress between the ply layers. The 90° circumferential ply provides circumferential restraint, preventing cross-sectional deformation of the rod under bending and compression. Specifically, the ply angles and proportions can be adjusted according to actual product manufacturing requirements.

[0029] In the mold assembly process, a release agent is first evenly applied to the mold surface to prevent the cured carbon fiber rod from sticking to the mold. Then, the preform is fitted onto the mold surface, and after fitting, OPP tape is wrapped again to ensure a tight fit between the preform and the mold. Specifically, the mold can be a smooth steel round tube, and the outer diameter of the mold matches the inner diameter of the vibrating rod. The secondary wrapping of the OPP tape further compacts the preform, eliminating tiny gaps between the fiber layer and the mold, ensuring uniform wall thickness and a smooth inner wall for the cured rod.

[0030] During the curing process, the epoxy resin matrix in the carbon fiber material undergoes a cross-linking reaction upon heating, firmly bonding the carbon fiber layers together to form a dense composite structure. The curing temperature is related to the type of carbon fiber material, with a specific range of 110℃ to 140℃. Controlling the heating rate during curing avoids excessive resin fluidity, fiber displacement, or thermal stress concentration that could lead to structural deformation due to rapid heating. Conversely, controlling the cooling rate prevents thermal stress concentration and internal microcracks caused by rapid cooling, thus ensuring the structural strength of the carbon fiber rods and extending their service life.

[0031] After curing, the demolding and post-processing steps begin. First, the cured carbon fiber rod and mold are allowed to cool naturally to room temperature before demolding. After demolding, both the inner and outer surfaces of the carbon fiber rod are polished to remove any residual release agent and minor imperfections, and to control the outer surface roughness Ra ≤ 1.6 μm. The post-processing step can be done manually or by machine, preferably using sandpaper of 800 grit or finer. After polishing, the carbon fiber rod is cut to a predetermined length, ultimately forming a vibratory rod suitable for bladeless wind power generation.

[0032] The carbon fiber rod consists of two fixed sections at both ends and an effective vibration section in the middle. The required length for cutting products After that, The fixed section is locally thickened to prevent the rod from breaking or loosening due to stress concentration during long-term vibration, ensuring a reliable connection between the finished vibratory rod and the fixed end of the equipment. Specifically, the two fixed sections have equal wall thickness.

[0033] Preferably, the ply design is configured such that the 0° axial ply accounts for 60%~70%, the ±45° diagonal ply accounts for 30%, and the +45° ply and -45° ply occupy the same number of layers; the 90° circumferential ply accounts for 0%~10%.

[0034] This invention allows for flexible adjustment of the performance parameters of the vibratory rod by adjusting the layup ratio according to actual needs, meeting the requirements of different application scenarios. For example, increasing the 0° layup ratio can significantly improve the first-order bending natural frequency and bending strength of the finished product, making it suitable for high-frequency, high-stiffness applications; increasing the ±45° layup ratio helps improve torsional performance and stress transfer uniformity, enhancing the durability of the rod under complex vibration modes; the 90° circumferential layup provides circumferential restraint to prevent cross-sectional deformation of the rod under bending and compression, and its proportion can be added or adjusted according to actual needs. In addition, the +45° layup and the -45° layup have the same number of layers to ensure symmetrical balance of the layup and avoid warping deformation during curing and under stress.

[0035] In the curing step, when the carbon fiber material has a standard or medium modulus, such as T300, T700, or T800 grade, the carbon fiber surface activity is high, and the matching curing temperature with epoxy resin is relatively low. Full cross-linking can be achieved at a curing temperature of 110℃ to 135℃. When the carbon fiber has a high modulus, such as T1100 or M60J grade, the degree of graphitization on the carbon fiber surface is higher, and the activity is lower, requiring a higher temperature to promote the cross-linking reaction. Therefore, the curing temperature is set to 120℃ to 140℃. This invention matches the optimal curing process according to the characteristics of different carbon fiber materials. By curing in different temperature ranges, it can effectively avoid poor interfacial bonding or structural deformation caused by improper curing temperature, ensuring the stable and reliable mechanical properties of the vibrating rod.

[0036] Preferably, in the demolding and post-processing steps, the fixed sections at both ends of the carbon fiber rod have the same thickness after thickening, ensuring that the clamping rigidity of the two ends of the carbon fiber rod is symmetrical, and avoiding local stress concentration or unbalanced force during vibration caused by thickness differences.

[0037] It also includes a testing step; the testing step specifically involves testing the parameters of coaxiality, wall thickness tolerance, first-order bending natural frequency, and bending strength of the carbon fiber rod after cutting. If any one of these parameters fails to meet the preset testing conditions, the product is deemed unqualified and reworked.

[0038] After cutting, this invention can perform performance tests on the carbon fiber rods, including coaxiality, wall thickness tolerance, first-order bending natural frequency, and bending strength, to eliminate defective products and ensure that the finished carbon fiber vibratory rods meet the application requirements of bladeless wind power generation. Specifically, coaxiality testing ensures the straightness of the rods; large deviations can cause eccentric vibration after installation, affecting power generation efficiency and equipment stability. Wall thickness tolerance testing prevents uneven mass distribution due to localized wall thickness deviations, which could affect the stable reproduction of the first-order bending natural frequency. The first-order bending natural frequency test verifies whether the finished product meets the resonance locking condition. Bending strength testing checks whether the finished product can withstand long-term reciprocating vibration without fracture or plastic deformation, ensuring a long fatigue life. If any of the above tests fails to meet the preset conditions, the product is deemed unqualified and reworked.

[0039] Specifically, the preset testing conditions can be set such that the coaxiality deviation of the finished product is less than or equal to 0.15 mm, and the wall thickness tolerance is controlled within ±0.1 mm. As for the testing requirements for the first-order bending natural frequency and bending strength, they can be set adaptively according to the required performance of the product. For example, for the subsequent Examples 3 to 5, under the condition that the customer requires the vibrating rod to achieve resonance locking in a low wind speed range of about 4.5 to 5.5 m / s, its first-order bending natural frequency should be between 9 Hz and 10.5 Hz.

[0040] This embodiment achieves control over the first-order bending natural frequency of the finished product through layering design in the weaving step, enabling the product to be stably reproduced. The process is simple, highly feasible, and can be adjusted according to different materials to meet different power generation scenarios and performance requirements. In addition, the carbon fiber vibrating rod is a hollow cylindrical structure without any internal reinforcement, which makes the structure simple and reliable, with high bending strength and long service life.

[0041] Example 2: See attached Figure 1 Secondly, this embodiment provides a carbon fiber vibrating rod, which is prepared using the carbon fiber vibrating rod preparation method described in Embodiment 1, as follows: The vibrating rod is a hollow cylindrical structure without internal reinforcing ribs, supporting ribs, or partitions. As can be seen from the above structure, the carbon fiber vibrating rod has an overall cylindrical structure, hollow inside and without any reinforcing ribs, supporting ribs, or partitions. This structure can significantly reduce the weight of the rod, achieving lightweight construction, thereby obtaining a larger amplitude and higher energy conversion efficiency under the same vibration excitation. At the same time, the absence of internal reinforcing ribs avoids stress concentration, which is beneficial to improving the fatigue life of the rod under long-term reciprocating vibration.

[0042] The vibrating rod includes an effective vibrating section and two fixed sections; the two fixed sections are located at both ends of the effective vibrating section; the wall thickness of the fixed sections is greater than that of the effective vibrating section. As can be seen from the above structure, the vibrating rod includes one effective vibrating section and two fixed sections, located at both ends of the effective vibrating section. The fixed sections are used for connection with components of other power generation equipment. To ensure the rigidity of the connection between the rod and the external equipment, the fixed sections are thickened.

[0043] Specifically, the wall thickness of the fixed section is 11.5mm to 12.5mm, and the wall thickness of the effective vibration section is 6.5mm to 8.0mm. As can be seen from the above structure, the effective vibration section of the vibrating rod is the main area where bending resonance occurs. Its wall thickness directly determines the mass distribution and bending strength of the rod, thus affecting the first-order bending natural frequency. A thinner wall thickness is beneficial for reducing mass and increasing frequency, but too thin a wall will lead to insufficient strength and easy breakage. A thicker wall thickness, while increasing strength, will increase mass and decrease frequency, making it difficult to meet the resonance locking requirements. Therefore, this embodiment provides a wall thickness parameter for the vibrating rod, controlling the wall thickness of the fixed section within the range of 11.5mm to 12.5mm and the wall thickness of the effective vibration section within the range of 6.5mm to 8.0mm. This achieves both lightweighting and first-order bending natural frequency control while meeting the bending strength requirements. In addition, the specific value of the wall thickness range of the effective vibration section of the vibrating rod needs to be adapted according to the grade of carbon fiber, so that finished products made of different grades of carbon fiber can achieve the required fixed vibration frequency and meet the application needs of different power generation scenarios.

[0044] The carbon fiber material is 24K carbon fiber. As can be seen from the above structure, 24K carbon fiber is a small-tow carbon fiber, with one bundle containing 24,000 monofilaments. This invention uses 24K carbon fiber, which can ensure the strength and stiffness of the fiber bundle while also considering weaving efficiency and cost. For example, T300, T700, T800, T1100, M60J, or other carbon fiber materials with different modulus grades can be used.

[0045] Example 3: This embodiment is prepared according to the preparation method described in Embodiment 1 and has the carbon fiber vibrating rod structure described in Embodiment 2, as detailed below: The carbon fiber material in this embodiment is a composite material of T700 grade 24K carbon fiber and epoxy resin matrix, wherein the fiber volume content is ≥70% and the resin content is ≤30%.

[0046] During the weaving process, the weaving speed is 1.8 m / h, the fiber tension is controlled at 6-7 N, and the weaving density is ≥95%. The specific layup design is as follows: 0° axial layup accounts for 60%, +45° diagonal layup accounts for 15%, -45° diagonal layup accounts for 15%, and 90° circumferential layup accounts for 10%.

[0047] In the curing step, the curing temperature is set to 110℃~135℃, and a tolerance of ±5℃ can be set for this temperature range; the constant temperature curing time is 2h~3h; the heating rate is ≤2℃ / min, and the cooling rate is ≤2.5℃ / min.

[0048] Specifically, the carbon fiber vibrating rod obtained based on this embodiment has an outer diameter of 105mm, an effective vibration section length of 5.0m, a wall thickness of 8.0mm, and an inner diameter of 89mm.

[0049] The finished products made according to the above method shall have the following testing requirements: first-order bending natural frequency of 9.0Hz~9.2Hz, bending strength ≥1850MPa, equivalent mass of 19.5kg~20.5kg, coaxiality ≤0.12mm, and wall thickness tolerance of ±0.1mm.

[0050] This solution is a mid-cost option for the T700, compatible with mainstream mass-produced bladeless wind turbines. It achieves a balance between cost and performance while ensuring that the first-order bending natural frequency meets customer requirements.

[0051] Example 4: This embodiment is prepared according to the preparation method described in Embodiment 1 and has the carbon fiber vibrating rod structure described in Embodiment 2, as detailed below: The carbon fiber material in this embodiment is a composite material of T800 grade 24K carbon fiber and epoxy resin matrix, wherein the fiber volume content is ≥70% and the resin content is ≤30%.

[0052] During the weaving process, the weaving speed is 1.8 m / h, the fiber tension is controlled at 6-7 N, and the weaving density is ≥95%. The specific layup design is as follows: 0° axial layup accounts for 60%, +45° diagonal layup accounts for 15%, -45° diagonal layup accounts for 15%, and 90° circumferential layup accounts for 10%.

[0053] In the curing step, the curing temperature is set to 110℃~135℃, and a tolerance of ±5℃ can be set for this temperature range; the constant temperature curing time is 2h~3h; the heating rate is ≤2℃ / min, and the cooling rate is ≤2.5℃ / min.

[0054] Specifically, the carbon fiber vibration rod obtained based on this embodiment has an outer diameter of 105mm, an effective vibration section length of 5.0m, a wall thickness of 7.5mm, and an inner diameter of 90mm.

[0055] The finished products made according to the above method shall have the following testing requirements: their first-order bending natural frequency is 9.0Hz~9.1Hz, bending strength is ≥1820MPa, equivalent mass is 18.5kg~19.5kg, coaxiality is ≤0.10mm, and wall thickness tolerance is ±0.1mm.

[0056] This solution is a mid-cost option for the T800. While ensuring that the first-order bending natural frequency meets customer requirements, it achieves a lighter design and is suitable for mass production applications where weight is a certain requirement.

[0057] Example 5: See attached Figure 1 This embodiment is prepared according to the preparation method described in Embodiment 1 and has the carbon fiber vibrating rod structure described in Embodiment 2, as detailed below: The carbon fiber material in this embodiment is a composite material of M60J grade 24K carbon fiber and epoxy resin matrix, wherein the fiber volume content is ≥70% and the resin content is ≤30%.

[0058] During the weaving process, the weaving speed is 1.5 m / h, the fiber tension is controlled at 7-8 N, and the weaving density is ≥95%. The specific layup design is as follows: 0° axial layup accounts for 70%, +45° diagonal layup accounts for 15%, -45° diagonal layup accounts for 15%, and 90° circumferential layup is not set.

[0059] In the curing step, the curing temperature is set to 120℃~140℃, and a tolerance of ±5℃ can be set for this temperature range; the constant temperature curing time is 2h~3h; the heating rate is ≤2℃ / min, and the cooling rate is ≤2.5℃ / min.

[0060] Specifically, the carbon fiber vibrating rod obtained based on this embodiment has an outer diameter of 105mm, an effective vibration section length of 5.0m, a wall thickness of 6.5mm, and an inner diameter of 92mm.

[0061] The finished products made according to the above method shall have the following testing requirements: their first-order bending natural frequency is 9.7Hz~9.9Hz, bending strength is ≥1950MPa, equivalent mass is 19.2kg~20.2kg, coaxiality is ≤0.10mm, and wall thickness tolerance is ±0.1mm.

[0062] This solution is the M60J high-performance solution, which has better anti-instability capabilities than Embodiments 3 and 4, strong long-term vibration stability, and can be adapted to high-end application scenarios that require products with high stability and long lifespan.

[0063] Example 6: This embodiment is prepared according to the preparation method described in Embodiment 1 and has the carbon fiber vibrating rod structure described in Embodiment 2, as detailed below: The carbon fiber material in this embodiment is a composite material of T300 grade 24K carbon fiber and epoxy resin matrix, wherein the fiber volume content is ≥70% and the resin content is ≤30%.

[0064] During the weaving process, the weaving speed is 1.8 m / h, the fiber tension is controlled at 6-7 N, and the weaving density is ≥95%. The specific layup design is as follows: 0° axial layup accounts for 60%, +45° diagonal layup accounts for 15%, -45° diagonal layup accounts for 15%, and 90° circumferential layup accounts for 10%.

[0065] In the curing step, the curing temperature is set to 110℃~135℃, and a tolerance of ±5℃ can be set for this temperature range; the constant temperature curing time is 2h~3h; the heating rate is ≤2℃ / min, and the cooling rate is ≤2.5℃ / min.

[0066] Specifically, the carbon fiber vibrating rod obtained based on this embodiment has an outer diameter of 105mm, an effective vibration section length of 5.0m, a wall thickness of 8.0mm, and an inner diameter of 89mm.

[0067] The finished products made according to the above method shall have the following testing requirements: their first-order bending natural frequency is 7.5Hz~7.7Hz, bending strength ≥1500MPa, equivalent mass is 19.5kg~20.5kg, coaxiality ≤0.13mm, and wall thickness tolerance is ±0.1mm.

[0068] Unlike the aforementioned Embodiments 3 to 5, this solution is a low-cost comparison solution for T300, designed for temporary or low-frequency use scenarios with limited budgets. In this case, performance requirements are reduced, and the limitations on detection parameters are different.

[0069] Comparative Example 1: The carbon fiber material used in this comparative example is a composite material of T700 grade 24K carbon fiber and epoxy resin matrix. The rod is a hollow cylindrical tube with a fiber volume content of ≥70%. Its outer diameter is 105mm, inner diameter is 89mm, wall thickness is 8.0mm, and effective vibration section length is 5.0m. That is, the dimensions are consistent with those of Example 3.

[0070] The difference between Comparative Example 1 and Example 3 is that the carbon fiber vibrating rod was prepared by conventional pultrusion molding process, and the carbon fibers were arranged unidirectionally with 0° axial layup, without ±45° oblique layup or 90° circumferential layup.

[0071] The key mechanical properties of Comparative Example 1 are shown in Table 1 after testing.

[0072] Table 1:

[0073] As shown in Table 1, in Comparative Example 1, the excessively high first-order bending natural frequency resulted in an inability to match the customer's target wind speed range, and also exhibited defects such as susceptibility to instability and low fatigue life. However, this invention, through process optimization, precisely controls the first-order bending natural frequency between 9Hz and 10.5Hz. Furthermore, while maintaining precise control over the first-order bending natural frequency, it also achieves significant improvements in circumferential stiffness, instability resistance, and fatigue life. Specifically, compared to Comparative Example 1, Example 3 shows a 122% increase in circumferential stiffness, a 137% increase in resistance to localized flattening, a 54% increase in critical load against instability, and a 38% increase in fatigue life.

[0074] It is evident that this invention can significantly improve the reliability and fatigue life of the vibratory rod while precisely controlling its first-order bending natural frequency.

[0075] It should be noted that the above description is merely a preferred embodiment of the present invention and does not limit the scope of the patent. The carbon fiber vibratory rod of the present invention is not limited to bladeless wind power generation equipment, but can also be used in other vibration energy harvesting devices or structural supports that require lightweight, high rigidity, and specific frequencies. Those skilled in the art should understand that the vibratory rod of the present invention can be applied to other technical fields without departing from the concept of the present invention. That is, any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for preparing a carbon fiber vibrating rod, characterized in that, Includes the following steps: Weaving steps: The carbon fiber material to be processed is mixed and woven according to the preset layup design ratio to form a preform; after weaving, OPP tape is used to wrap it to eliminate interlayer gaps; wherein, the weaving density is ≥95%, the weaving speed is 1.5m / h~2m / h, and the fiber tension is 5N~8N; the layup design includes one or more of 0° axial layup, ±45° oblique layup, and 90° circumferential layup; Mold assembly steps: Apply release agent evenly to the mold surface, and put the woven preform onto the mold; then use OPP tape to make the preform fit tightly against the mold; Curing step: The mold containing the preformed blank is heated and cured; the curing temperature is 110~140℃, the constant temperature curing time is 2h~3h, the heating rate is ≤2℃ / min, and the cooling rate is ≤2.5℃ / min. Demolding and post-processing steps: Demold after natural cooling to room temperature to obtain carbon fiber rods; grind both the inner and outer surfaces of the carbon fiber rods to make the outer surface roughness Ra≤1.6μm; then cut according to the preset rod length, and thicken the fixed sections at both ends of the carbon fiber rods to finally obtain the finished vibration rod.

2. The method for preparing the carbon fiber vibrating rod according to claim 1, characterized in that, The ply design is configured such that the 0° axial ply accounts for 60%~70%, the ±45° diagonal ply accounts for 30% in total, and the +45° ply and the -45° ply occupy the same number of layers; the 90° circumferential ply accounts for 0%~10%.

3. The method for preparing the carbon fiber vibrating rod according to claim 1 or 2, characterized in that, In the curing step, when the carbon fiber material has a standard modulus or a medium modulus, the curing temperature is 110℃~135℃; when the carbon fiber material has a high modulus, the curing temperature is 120℃~140℃.

4. The method for preparing the carbon fiber vibrating rod according to claim 1, characterized in that, In the demolding and post-processing steps, the fixed sections at both ends of the carbon fiber rod have the same thickness after thickening.

5. The method for preparing the carbon fiber vibrating rod according to claim 1, characterized in that, It also includes a testing step; the testing step specifically involves testing the parameters of coaxiality, wall thickness tolerance, first-order bending natural frequency and bending strength of the carbon fiber rod after cutting. If any one of these parameters fails to meet the preset testing conditions, the product is deemed unqualified and reworked.

6. A carbon fiber vibrating rod, manufactured using the method described in any one of claims 1 to 5, characterized in that: The vibrating rod is a hollow cylindrical structure with no internal reinforcing ribs, supporting ribs, or partitions.

7. The carbon fiber vibrating rod according to claim 6, characterized in that: The vibrating rod includes an effective vibrating section and two fixed sections; the two fixed sections are located at both ends of the effective vibrating section; the wall thickness of the fixed sections is greater than the wall thickness of the effective vibrating section.

8. The carbon fiber vibrating rod according to claim 7, characterized in that: The wall thickness of the fixed section is 11.5mm to 12.5mm.

9. The carbon fiber vibrating rod according to claim 8, characterized in that: The effective vibration section has a wall thickness of 6.5 mm to 8.0 mm.

10. The carbon fiber vibrating rod according to claim 9, characterized in that: The carbon fiber material is 24K carbon fiber.

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