Method and equipment for producing carbon fiber composite mandrels with embedded optical fibers

Abstract

This invention provides a method and equipment for producing carbon fiber composite core rods with embedded optical fibers, belonging to the technical field of carbon fiber composite core conductors. The equipment includes a fiber feeding device, a first impregnation device, a pre-forming positioning device, a curing and shaping device, and a traction device connected sequentially. The fiber feeding device has an optical fiber feeding unit, a protective fiber feeding unit, and multiple carbon fiber feeding units. The pre-forming positioning device forms a central channel and an edge channel. The traction device provides traction force for the cured and shaped carbon fiber composite core rod, and the winding device is used for winding the finished core rod. The method and equipment for producing carbon fiber composite core rods with embedded optical fibers provided by this invention can ensure that the optical fiber is basically centered in the carbon fiber core rod under minimal tension, effectively improving the problem of difficult-to-control optical fiber position in the carbon fiber core rod and ensuring the accuracy of testing.

Description

Technical Field

[0001] This invention belongs to the field of carbon fiber composite core conductor technology, specifically relating to a method and equipment for producing carbon fiber composite core rods for implanting optical fibers. Background Technology

[0002] With rapid economic development and continuously increasing social electricity demand, situations where the power supply load exceeds the transmission capacity limit of power lines are commonplace. Power grid companies have had to invest heavily in upgrading existing transmission lines, significantly increasing operation and maintenance costs. Furthermore, traditional transmission conductors, primarily steel-cored aluminum stranded wire, suffer from problems such as high elongation and poor heat resistance. During peak summer electricity consumption periods, under extremely high temperatures and heavy loads, lines overheat, and sag exceeds safe operating limits, easily leading to line faults and power outages. Therefore, to improve transmission capacity and meet the ever-increasing power load demands, the research and development of new conductor types has never ceased.

[0003] Transmission conductors mainly consist of two parts: an outer aluminum conductor, which primarily transmits the load; and an inner core, which provides mechanical support. The transmission capacity of a transmission conductor is determined by a combination of factors, including the intrinsic conductivity (IACS) of the aluminum conductor, the line's heat resistance (sag), and line losses (including resistance and reactance). Carbon fiber composite cores, however, possess advantages such as light weight, high mechanical strength, low sag, high current carrying capacity, low coefficient of thermal expansion, and energy efficiency. They exhibit unparalleled advantages over other types of conductors in increasing transmission capacity, reducing sag, minimizing line losses, and improving wind resistance, earning them the industry name "superconducting conductors." Upgrading transmission lines using carbon fiber composite cores not only fully utilizes existing tower resources but also significantly increases transmission capacity, making it an effective means of addressing rapid load growth and limited transmission corridor resources.

[0004] However, the core of carbon fiber composite conductors is made of carbon fiber impregnated with resin, which has low elongation and a limited bending radius, making it susceptible to damage during construction. This can lead to problems such as strand breakage, coiling, and core pull-out, and may even cause the core rod to break. Since the core rod is encased within the aluminum conductor, damage to it is a hidden defect. Once this occurs, the carbon fiber composite conductor will operate with this defect, ultimately causing a transmission line outage, posing a significant threat to the safe operation of the power grid and the safety of people and property. Therefore, non-destructive testing technology for carbon fiber composite conductor defects, especially non-destructive testing technology for carbon fiber composite cores during construction, has always been a research hotspot in this field.

[0005] Existing non-destructive testing methods for carbon fiber composites mainly include infrared, eddy current, ultrasonic, acoustic emission, and X-ray. For conventional steel-cored aluminum stranded conductors, eddy current testing and magnetic flux leakage testing can be used simultaneously to detect damage to the aluminum strands and steel core, respectively. However, because carbon fiber composites are non-magnetic, methods such as magnetic flux leakage testing and metal magnetic memory testing cannot be used. X-ray real-time imaging technology, with the X-ray transmission direction perpendicular to the tangent of the core rod, can detect most interface defects as the conductor rotates. It allows for real-time online inspection of products at any position and rotation angle, producing images with high clarity and sensitivity. However, X-ray inspection methods have low sensitivity for detecting surface or internal cracks in carbon fiber conductors, resulting in blurry images with insufficient contrast at defect locations. Furthermore, due to the long transmission lines, online inspection requires the identification of numerous images, making it prone to missed detections due to personnel fatigue, thus limiting its feasibility in field applications. Laser ultrasound utilizes the instantaneous thermal effect of high-energy laser pulses on the surface of a material to create a thermal characteristic zone on the solid surface, forming thermal stress and generating ultrasonic waves inside the object. However, power transmission lines are hundreds to thousands of meters long, and the defect signal suffers from attenuation. Furthermore, the surface of the power transmission line is not smooth, resulting in significant sound wave divergence. Therefore, ultrasonic testing is only suitable for short-distance damage detection of carbon fiber composite core rods. Based on the structure of carbon fiber composite conductors, the glass fibers of the core rod separate the carbon fiber bundles and aluminum strands, allowing individual heating of the carbon fibers. Infrared thermal imagers can then be used to detect defects on the surface of objects or materials using radiation. Defects such as voids, cracks, and uneven thickness may form due to impact or during manufacturing. These defects cause uneven heat transfer, resulting in different temperatures at different locations. After processing, these differences are displayed on an oscilloscope or computer screen, showing higher temperatures at the defect locations. However, infrared technology can only sample and inspect the carbon fiber core rod, thus not enabling practical non-destructive testing of carbon fiber composite core conductors.

[0006] It is evident that commonly used non-destructive testing (NDT) methods all have significant limitations, resulting in low practicality. To address this practicality issue, carbon fiber composite conductors with embedded optical fibers have emerged. These conductors utilize the principle of optical time-domain reflectometry (OTDR) to inject probe light pulses into the sensing fiber. As the pulsed light propagates within the fiber, it generates backscattered light. By connecting the fiber to an external monitoring device, the attenuation loss value of the backscattered light can be used to determine if there are hidden defects in the core rod. The return time of the backscattered light can be used to determine the location of light scattering (i.e., the location of abnormal strain points), thus achieving the purpose of defect detection and localization. NDT methods based on this conductor structure are not limited by conductor length and offer high accuracy, effectively overcoming the limitations of traditional testing methods. In carbon fiber composite conductors with embedded optical fibers, the position of the optical fiber significantly affects the sensing accuracy. The optical fiber needs to be centered on the carbon fiber core rod to ensure synchronous deformation, thereby accurately sensing stress changes and reflecting defect locations. However, in existing manufacturing processes, the stability of the optical fiber position is difficult to control, and the fiber is prone to significant deviations from the center of the carbon fiber core rod, affecting the accuracy of the detection. Summary of the Invention

[0007] This invention provides a method and equipment for producing a carbon fiber composite core rod with embedded optical fiber, aiming to solve the problem of difficulty in controlling the position of the optical fiber in the carbon fiber core rod in the limiting technology.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] In a first aspect, a method for producing a carbon fiber composite mandrel with embedded optical fiber is provided, comprising:

[0010] S100. Release the optical fiber with a first tension, release the protective fiber bundle with a second tension, and release multiple carbon fiber bundles with a third tension, wherein the second tension is greater than the first tension, and the first tension is greater than the third tension;

[0011] S200, Impregnate the optical fiber, the protective fiber bundle, and the multiple bundles of the carbon fiber bundle with resin;

[0012] S300, the optical fiber, the protective fiber bundle, and at least one of the carbon fiber bundles are passed through the central channel, and the remaining multiple carbon fiber bundles are passed through multiple edge channels respectively. The multiple edge channels are evenly distributed around the central channel, and the protective fiber bundle forms a protective fiber bundle layer on the outer periphery of the optical fiber, and the carbon fiber bundles form a carbon fiber bundle layer on the outer periphery of the protective fiber bundle layer.

[0013] S400, the optical fiber, the protective fiber bundle, and the carbon fiber bundle are cured and shaped.

[0014] In conjunction with the first aspect, in one possible implementation, step S200 further includes:

[0015] The optical fiber and the protective fiber bundle are passed through the central channel, and multiple carbon fiber bundles are passed through multiple side channels respectively. The central channel and the multiple side channels are all located on the same horizontal plane, and the multiple side channels are symmetrically arranged about the central channel.

[0016] In conjunction with the first aspect, in one possible implementation, step S400 specifically includes:

[0017] S410. Bundle the optical fiber, the protective fiber bundle, and the carbon fiber bundle together to obtain a preformed bundle;

[0018] S420. Wrap the outer periphery of the preformed bundle with an impregnated outer protective strip to obtain a preformed core rod;

[0019] S430. The preformed mandrel is heated and cured to obtain a carbon fiber composite mandrel.

[0020] In some embodiments, step S430 specifically includes:

[0021] S431. The preformed mandrel is introduced into the shaping channel for shaping and heating.

[0022] S432. The pre-formed mandrel that has been shaped and heated is introduced into the curing channel for curing and heating to obtain a carbon fiber composite mandrel.

[0023] In conjunction with the first aspect, in one possible implementation, step S200 further includes:

[0024] The carbon fiber bundles are pre-dried.

[0025] In conjunction with the first aspect, in one possible implementation, step S300 further includes the following prior to:

[0026] The carbon fiber bundles are dried a second time;

[0027] The optical fiber, the protective fiber bundle, and the multiple bundles of carbon fiber that have undergone secondary drying are impregnated with resin.

[0028] In conjunction with the first aspect, in one possible implementation, step S300 further includes the following prior to:

[0029] The optical fiber, the protective fiber bundle, and the multiple bundles of carbon fiber are subjected to protective heating.

[0030] Compared with the prior art, the solution shown in this application, by reasonably controlling the first tension, the second tension, and the third tension, allows the optical fiber and the protective fiber bundle to pass through the same central channel before entering the curing and shaping stage. This allows the protective fiber bundle with higher tension to wrap more evenly around the outer periphery of the optical fiber with relatively lower tension. The optical fiber and the protective fiber bundle together constitute the core structure. Since the carbon fiber bundle has the lowest tension and is located relatively far outward from the core structure, after being guided by the edge channel, the carbon fiber bundle spontaneously and evenly wraps around the outer periphery of the core structure, forming a pre-formed bundle centered on the optical fiber. After the pre-formed bundle is cured, it can ensure that the optical fiber is basically in the center of the carbon fiber core rod under the premise of minimum tension, effectively improving the problem of difficult control of the position of the optical fiber in the carbon fiber core rod and ensuring the accuracy of detection.

[0031] Secondly, embodiments of the present invention also provide a carbon fiber composite core rod production equipment for implanting optical fibers, used to implement the above-mentioned carbon fiber composite core rod production method for implanting optical fibers, including a fiber feeding device, a first impregnation device, a pre-forming positioning device, a curing and shaping device, a traction device, and a winding device connected in sequence:

[0032] The fiber feeding device has an optical fiber feeding unit, a protective fiber feeding unit, and multiple carbon fiber feeding units;

[0033] The preforming positioning device has the central channel and the edge channel, the traction device is used to provide traction force to the cured and shaped carbon fiber composite mandrel, and the winding device is used to roll the finished mandrel.

[0034] In conjunction with the second aspect, in one possible implementation, the fiber feeding device forms an upper fiber feeding region, a middle fiber feeding region, and a lower fiber feeding region distributed sequentially from top to bottom, wherein at least two of the carbon fiber fiber feeding units are distributed along a preset horizontal path in the upper fiber feeding region, the remaining carbon fiber fiber feeding units are distributed along the preset horizontal path in the lower fiber feeding region, and the optical fiber feeding unit and the protective fiber feeding unit are distributed in the middle fiber feeding region.

[0035] In some embodiments, the fiber feeding device further has a plurality of upper fiber feeding holes and a plurality of lower fiber feeding holes; the plurality of upper fiber feeding holes correspond to a plurality of carbon fiber feeding units located in the upper fiber feeding region; the plurality of lower fiber feeding holes correspond to a plurality of carbon fiber feeding units located in the lower fiber feeding region.

[0036] Compared with the prior art, the solution shown in this application, by controlling the traction speed of the traction device and the release speed of the fiber laying unit, the protective fiber laying unit, and the carbon fiber laying unit, achieves control over the first tension, the second tension, and the third tension. This allows the optical fiber and the protective fiber bundle to pass through the same central channel before entering the curing and shaping device, thus ensuring that the protective fiber bundle with higher tension is more evenly wrapped around the outer periphery of the optical fiber with relatively lower tension. The optical fiber and the protective fiber bundle together constitute the core structure. Since the carbon fiber bundle has the lowest tension and is positioned relatively outward from the core structure, after being guided by the edge channel, the carbon fiber bundle spontaneously and evenly covers the outer periphery of the core structure, forming a pre-formed bundle centered on the optical fiber. After the pre-formed bundle is cured, it ensures that the optical fiber is essentially at the center of the carbon fiber core rod under the premise of minimum tension, effectively improving the problem of difficult-to-control position of the optical fiber in the carbon fiber core rod and ensuring the accuracy of detection. Attached Figure Description

[0037] Figure 1 A cross-sectional view of a carbon fiber composite core rod produced by the method for producing a carbon fiber composite core rod with implanted optical fiber provided in an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the structure of a carbon fiber composite mandrel production equipment with implanted optical fiber provided in an embodiment of the present invention, wherein the solid arrows indicate the moving directions of the optical fiber, the protective fiber bundle, and the carbon fiber bundle.

[0039] Figure 3 for Figure 2 Right view of the center positioning plate;

[0040] Figure 4 for Figure 2 Right view of the upper wire feeding plate;

[0041] Figure 5 This is a usage state diagram of the wire breakage alarm mechanism used in an embodiment of the present invention, wherein the dashed line represents the signal path;

[0042] Figure 6 This is a schematic diagram of the carbon fiber feeding unit used in an embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of the first impregnation device used in an embodiment of the present invention, wherein the dashed arrows indicate the moving directions of the optical fiber, the protective fiber bundle, and the carbon fiber bundle;

[0044] Figure 8 for Figure 2 Right view of the splitting wire device;

[0045] Figure 9 for Figure 8 Enlarged view of part A.

[0046] Explanation of reference numerals in the attached figures:

[0047] 100. Carbon fiber composite mandrel;

[0048] 1. Optical fiber; 2. Protective fiber bundle; 3. Carbon fiber bundle; 4. Inner protective layer; 5. Carbon fiber layer; 6. Central channel; 7. Edge channel; 8. Middle channel; 9. Side channel; 10. Outer protective layer;

[0049] 11. Fiber feeding device; 1110. Fiber optic fiber feeding unit; 1111. Signal transmitter; 1112. Signal receiver; 1113. Wire breakage triggering component; 1120. Protective fiber feeding unit; 1130. Carbon fiber feeding unit; 1131. Feeding shaft; 1132. Braking ring; 1133. Braking pad; 1134. Braking elastic element; 1135. Flexible rope; 1140. Upper feeding hole; 1160. Upper feeding plate; 1170. Lower feeding plate;

[0050] 12. First dipping device; 1210. First glue tank; 1220. First dipping roller; 1230. Second dipping roller; 1240. Dipping pressure roller assembly;

[0051] 13. Pre-forming positioning device; 1310. Positioning plate;

[0052] 14. Curing and shaping device; 1410. Shaping and heating mold; 1420. Curing mechanism;

[0053] 15. Traction device;

[0054] 16. Winding device;

[0055] 17. Meter counter;

[0056] 18. Tape feeding device;

[0057] 19. First drying device;

[0058] 20. Transition roller frame;

[0059] 21. Wire separating device; 2110. Wire separating guide roller; 2120. Wire separating grid;

[0060] 22. Second drying device;

[0061] 23. Heating device. Detailed Implementation

[0062] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0063] Unless otherwise expressly defined, the use of terms such as "first," "second," or "third" in the claims, description, and accompanying drawings of this invention is for distinguishing different objects and not for describing a specific order.

[0064] Unless otherwise expressly defined, in the claims, description, and accompanying drawings of this invention, the use of directional terms such as "center," "lateral," "longitudinal," "horizontal," "vertical," "top," "bottom," "inner," "outer," "upper," "lower," "front," "rear," "left," "right," "clockwise," "counterclockwise," "high," and "low" to indicate orientation or positional relationships is based on the orientation and positional relationships shown in the accompanying drawings and is only for the convenience of describing the invention and simplifying the description, and is not intended to 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 limiting the specific scope of protection of this invention.

[0065] Unless otherwise expressly defined, the terms "fixed connection" or "fixed connection" used in the claims, description and drawings of this invention should be interpreted broadly to refer to any connection in which there is no displacement or relative rotation relationship between the two parties, including non-removable fixed connection, detachable fixed connection, integral connection and fixed connection by other means or components.

[0066] In the claims, description and accompanying drawings of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0067] The method for producing a carbon fiber composite core rod for implanting optical fibers provided by the present invention will now be described. The method for producing the carbon fiber composite core rod for implanting optical fibers includes the following steps:

[0068] S100. Fiber 1 is released under a first tension, protective fiber bundle 2 is released under a second tension, and multiple carbon fiber bundles 3 are released under a third tension, wherein the second tension is greater than the first tension, and the first tension is greater than the third tension.

[0069] S200, impregnate optical fiber 1, protective fiber bundle 2 and multiple carbon fiber bundles 3 with resin;

[0070] S300, make the optical fiber 1, the protective fiber bundle 2 and at least one of the carbon fiber bundles 3 pass through the central channel 6, and make the remaining multiple carbon fiber bundles 3 pass through multiple edge channels 7 respectively. The multiple edge channels 7 are evenly distributed around the central channel 6, so that the protective fiber bundle 2 forms a protective fiber bundle layer on the outer periphery of the optical fiber 1, and the carbon fiber bundle 3 forms a carbon fiber bundle layer on the outer periphery of the protective fiber bundle layer.

[0071] S400, solidify and shape optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3.

[0072] The carbon fiber composite mandrel manufactured using the method provided in this embodiment mainly includes an optical fiber 1 at the center, an inner protective layer 4 covering the outer periphery of the optical fiber 1, and a carbon fiber layer 5 covering the outer periphery of the inner protective layer 4. The inner protective layer 4 is formed by curing a protective fiber bundle 2, and the carbon fiber layer 5 is formed by curing a carbon fiber bundle 3. Figure 1 As shown.

[0073] It should also be noted that in this embodiment, the protective fiber bundle layer is a layer structure that protects the fiber bundle surrounding the optical fiber 1. It has not yet been cured and has not formed the inner protective layer 4. The protective fiber bundle layer forms a protective layer on the outer periphery of the optical fiber 1, enhancing the ability of the optical fiber 1 to resist external forces and preventing the optical fiber 1 from breaking. The carbon fiber bundle layer is also a similar structure. It has not yet been cured and has not formed the carbon fiber layer 5.

[0074] In this embodiment, in order to make the carbon fiber bundles 3 evenly distributed, the multiple carbon fiber bundles 3 are evenly distributed in the central channel 6 and the edge channel 7. That is, the number of carbon fiber bundles 3 passing through the central channel 6 is the same as the number of carbon fiber bundles 3 passing through a single edge channel 7, and the number of carbon fiber bundles 3 passing through different edge channels 7 is also the same.

[0075] The fiber-coated carbon fiber composite core rod production method provided in this embodiment, compared with the prior art, can, by reasonably controlling the first tension, the second tension, and the third tension, allow the fiber 1 and the protective fiber bundle 2 to pass through the same central channel 6 before entering the curing and shaping stage. This allows the protective fiber bundle 2, which has a higher tension, to wrap more evenly around the outer periphery of the fiber 1, which has a relatively lower tension. The fiber 1 and the protective fiber bundle 2 together constitute the core structure. Since the carbon fiber bundle 3 has the lowest tension and is located relatively far outward from the core structure, after being guided by the edge channel, the carbon fiber bundle 3 spontaneously and evenly wraps around the outer periphery of the core structure, forming a pre-formed bundle centered on the fiber 1. After the pre-formed bundle centered is cured, it can ensure that the fiber 1 is basically in the center of the carbon fiber core rod under the premise of minimum tension, effectively improving the problem of difficult control of the position of the fiber 1 in the carbon fiber core rod and ensuring the accuracy of detection.

[0076] In some embodiments, before step S200, the method further includes: passing the optical fiber 1 and the protective fiber bundle 2 through the intermediate channel 8, and passing the multiple carbon fiber bundles 3 through the multiple side channels 9 respectively, wherein the intermediate channel 8 and the multiple side channels 9 are located on the same horizontal plane, and the multiple side channels 9 are symmetrically arranged about the intermediate channel 8.

[0077] In this embodiment, before the optical fiber 1, protective fiber bundle 2, and carbon fiber bundle 3 enter the central channel 6 and the edge channel 7 respectively, they first pass through the guide splitting of the middle channel 8 and the side channel 9. On the one hand, this can split the optical fiber 1, protective fiber bundle 2, and carbon fiber bundle 3, avoiding the problem of the optical fiber 1, protective fiber bundle 2, and carbon fiber bundle 3 becoming entangled later. On the other hand, it can also reduce the influence of gravity on the sag of the optical fiber 1, protective fiber bundle 2, and carbon fiber bundle 3, which is conducive to more precise control of tension.

[0078] In some embodiments, step S400 specifically includes:

[0079] S410. The optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3 that pass through the central channel 6 and the edge channel 7 respectively are bundled together. The optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3 are bonded together under the action of adhesive to form a preformed bundle.

[0080] S420. Wrap the outer periphery of the preformed bundle with an outer protective strip that has been impregnated with resin to obtain a preformed mandrel;

[0081] S430. The preformed mandrel is heated and cured to obtain a carbon fiber composite mandrel, and an outer protective layer 10 is formed by an outer protective strip.

[0082] like Figure 1 As shown, in this embodiment, an outer protective layer 10 is formed on the outer periphery of the carbon fiber layer 5. The outer protective layer 10 forms an isolation between the carbon fiber layer 5 and the aluminum stranded wire, avoiding galvanic corrosion between the two and ensuring the reliability of the overall performance of the conductor.

[0083] In some embodiments, step S430 specifically includes:

[0084] S431. The preformed mandrel is introduced into the shaping channel and heated for shaping to achieve the initial shaping of the preformed mandrel;

[0085] S432. In order to compensate for the problem of insufficient shaping and heating time and to make the adhesive curing reaction more complete, the pre-shaped mandrel after shaping and heating is introduced into the curing channel for curing and heating to obtain carbon fiber composite mandrel 100.

[0086] In this embodiment, the protective fiber bundle layer forms a buffer protection on the outer periphery of the optical fiber 1, which alleviates the squeezing and deformation force on the optical fiber 1 and reduces the attenuation loss of the optical fiber 1.

[0087] Based on the above embodiments, step S431 specifically includes: dividing the shaping channel into multiple segments sequentially connected along the moving direction of the pre-formed mandrel, and the heating temperature of each segment increasing sequentially along the moving direction of the pre-formed mandrel. This zoned heating method allows the temperature inside the pre-formed mandrel to rise gradually, improving the uniformity of the temperature field within the pre-formed mandrel, resulting in a more complete curing reaction, increased structural strength of the mandrel, and also saving heat energy and reducing energy consumption.

[0088] In some embodiments, in order to reduce the moisture content of the carbon fiber bundle 3, the process further includes pre-drying the carbon fiber bundle 3 before step S200.

[0089] In some embodiments, to further reduce the water content of the carbon fiber bundle 3, the method further includes the following steps before step S300:

[0090] Secondary drying of carbon fiber bundles 3;

[0091] The optical fiber 1, the protective fiber bundle 2, and the multiple carbon fiber bundles 3 that have undergone secondary drying are impregnated with resin.

[0092] In some embodiments, before step S300, the process further includes: protective heating of the optical fiber 1, the protective fiber bundle 2, and the multiple carbon fiber bundles 3. Before entering the shaping channel, the cross-section of the preformed mandrel is generally flat, and after entering the shaping channel, the cross-section becomes circular. To prevent the mandrel from bending, it is necessary to maintain the viscosity fluctuation of the adhesive before entering the shaping channel, hence the protective heating is performed before entering the shaping channel.

[0093] Given that the carbon fiber bundle 3 is of type T700-12K and the optical fiber 1 is a single-mode optical fiber with a temperature resistance greater than 150℃, the specific implementation method of the carbon fiber composite core rod with embedded optical fiber in this application is illustrated below:

[0094] 1) Determine the number of carbon fiber bundles 3 according to the size requirements of the carbon fiber composite mandrel. In this embodiment, five bundles are shown as an example.

[0095] 2) Determine the release positions of optical fiber 1 and protective fiber bundle 2, and divide the release positions of carbon fiber bundle 3 into two groups, one group located above the release positions of optical fiber 1 and protective fiber bundle 2, and the other group located below the release positions of optical fiber 1 and protective fiber bundle 2.

[0096] 3) Adjust the pulling speed and release tension of optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3 so that the third tension is 500-800N, the first tension and the second tension are 800-1200N (for example, the third tension is 700N, the first tension is 1000N and the second tension is 1200N), and the pulling speed of optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3 is 35-60cm / min.

[0097] 4) The optical fiber 1, the protective fiber bundle 2 and the carbon fiber bundle 3 are pre-dried by infrared heating at a temperature of 60-100℃ (e.g., 80℃).

[0098] 5) Splitting: One optical fiber 1, one bundle of protective fiber 2, and one bundle of carbon fiber 3 are passed together through the central channel 8, and the remaining carbon fiber bundles 3 are passed through the symmetrically distributed side channels 9 located on both sides of the central channel 8, wherein each side channel 9 corresponds to one bundle of carbon fiber 3; or, one optical fiber 1, two bundles of protective fiber 2, and one bundle of carbon fiber 3 are passed together through the central channel 8, and the remaining carbon fiber bundles 3 are passed through the symmetrically distributed side channels 9 located on both sides of the central channel 8, wherein each side channel 9 corresponds to two bundles of carbon fiber 3.

[0099] 6) The split optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3 are dried a second time. The drying method can be infrared heating drying, and the drying temperature is 60-100℃ (e.g. 80℃).

[0100] 7) The optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3, which have been dried twice, are impregnated with a resin at a constant temperature of 25-35℃ (e.g., 30℃). The resin can be a high-temperature epoxy resin with a glass transition temperature of 150-230℃ and a viscosity of 1000-3500 mPa·s (25℃).

[0101] 8) The resin-impregnated optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3 are subjected to protective heating, and the heating temperature is kept constant at 25-35℃ (e.g. 30℃) and the humidity is kept constant at 20%-45% (e.g. 40%).

[0102] 9) Pass the optical fiber 1 and the protective fiber bundle 2 through the middle channel 8, and pass the multiple carbon fiber bundles 3 through the multiple side channels 9 respectively to obtain a preformed bundle, wherein the number of carbon fiber bundles 3 accommodated in each side channel 9 is the same.

[0103] 10) Wrap an impregnated outer protective tape around the preformed bundle formed by optical fiber 1, protective fiber bundle 2 and carbon fiber bundle 3 to obtain a preformed mandrel. The outer protective tape can be an alkali-free and boron-free glass fiber woven tape with a width of 10-20 mm and a thickness of 0.1-0.2 mm.

[0104] 11) The preformed mandrel is introduced into the shaping channel for shaping heating. The length of the shaping channel is 500-900mm, and the diameter of the shaping channel is (Ф-0.02mm) to (Ф+0.02mm), where Ф is the designed diameter of the mandrel in mm. In addition, the heating area of ​​the shaping channel is divided into three sections along the direction of mandrel movement: section one, section two, and section three. The temperature of section one is 145-155℃, the temperature of section two is 175-190℃, and the temperature of section three is 190-210℃.

[0105] 12) The preformed mandrel that has been shaped and heated is introduced into the curing channel for curing heating to obtain a carbon fiber composite mandrel, wherein the curing heating temperature is 180~220℃.

[0106] Based on the same inventive concept, this application also provides a carbon fiber composite mandrel production equipment with implanted optical fibers, used to realize the above-mentioned carbon fiber composite mandrel production method with implanted optical fibers, including a fiber feeding device 11, a first impregnation device 12, a pre-forming positioning device 13, a curing and shaping device 14, and a traction device 15 connected in sequence: the fiber feeding device 11 has an optical fiber feeding unit 1110, a protective fiber feeding unit 1120, and a plurality of carbon fiber feeding units 1130; the pre-forming positioning device 13 forms a central channel 6 and an edge channel 7, and the traction device 15 is used to provide traction force to the cured and shaped carbon fiber composite mandrel 100.

[0107] In this embodiment, the outlet side of the traction device 15 is also equipped with a winding device 16 for winding the finished mandrel. The inlet side of the traction device 15 is equipped with a meter counter 17 and a continuous diameter measurement early warning device. The meter counter 17 is used to measure the length of the carbon fiber composite mandrel, while the continuous diameter measurement early warning device monitors the outer diameter of the carbon fiber composite mandrel in real time. If a sudden change in the outer diameter is detected, an alarm is triggered, and the operator can mark the abnormal area in time. In specific implementation, the traction device 15 is a tracked traction device, that is, the carbon fiber composite mandrel is squeezed and pulled by two tracks, which can provide a reliable traction force.

[0108] In this embodiment, the optical fiber feeding unit 1110, the protective fiber feeding unit 1120, and the carbon fiber feeding unit 1130 are all spool structures capable of winding and releasing filaments, and each is equipped with a tension sensor (the specific setting of the tension sensor can refer to existing settings, such as a cantilever tension sensor, which will not be described in detail here); the optical fiber feeding unit 1110 also has a tension adjustment wheel assembly supporting the optical fiber 1 (such as... Figure 2 As shown, tension adjustment can be achieved by adjusting the position of each tension wheel in the tension adjustment wheel group; the fiber release unit 1120 directly adjusts the second tension by controlling the release speed and adjusting the difference between the release speed and the traction speed.

[0109] The fiber-embedded carbon fiber composite core rod production equipment provided in this embodiment, compared with the prior art, controls the first tension, second tension, and third tension by controlling the traction speed of the traction device 15 and the release speed of the fiber laying unit 1110, the protective fiber laying unit 1120, and the carbon fiber laying unit 1130. This allows the fiber 1 and the protective fiber bundle 2 to pass through the same central channel 6 before entering the curing and shaping device 14, thus ensuring that the protective fiber bundle 2, with higher tension, is more evenly wrapped around the outer periphery of the fiber 1, with relatively lower tension. The fiber 1 and the protective fiber bundle 2 together constitute the core structure. Since the carbon fiber bundle 3 has the lowest tension and is positioned relatively outward from the core structure, after being guided by the edge channel 7, the carbon fiber bundle 3 spontaneously and evenly covers the outer periphery of the core structure, forming a pre-formed bundle centered on the fiber 1. After the pre-formed bundle is cured, it ensures that the fiber 1 is basically in the center of the carbon fiber core rod under the premise of minimum tension, effectively improving the problem of difficult-to-control fiber position in the carbon fiber core rod and ensuring the accuracy of detection.

[0110] In some embodiments, see Figure 1 The fiber feeding device 11 has an upper feeding area, a middle feeding area, and a lower feeding area distributed sequentially from top to bottom. At least two carbon fiber feeding units 1130 are distributed along a preset horizontal path in the upper feeding area, and the remaining carbon fiber feeding units 1130 are distributed along a preset horizontal path in the lower feeding area. The optical fiber feeding unit 1110 and the protective fiber feeding unit 1120 are distributed in the middle feeding area. In this embodiment, the positions of each feeding unit are rationally arranged to accurately control the tension.

[0111] See Figure 2 and Figure 4 In some embodiments, the fiber feeding device 11 further has a plurality of upper fiber feeding holes 1140 and a plurality of lower fiber feeding holes; the plurality of upper fiber feeding holes 1140 correspond to a plurality of carbon fiber feeding units 1130 located in the upper fiber feeding region, and the plurality of upper fiber feeding holes 1140 correspond one-to-one with the plurality of carbon fiber feeding units 1130 located in the upper fiber feeding region; the plurality of lower fiber feeding holes correspond to a plurality of carbon fiber feeding units 1130 located in the lower fiber feeding region, and the plurality of lower fiber feeding holes correspond one-to-one with the plurality of carbon fiber feeding units 1130 located in the lower fiber feeding region. In specific implementation, the upper wire feeding hole 1140 is located on the upper wire feeding plate 1160, and the lower wire feeding hole is located on the lower wire feeding plate 1170. Both the upper and lower wire feeding holes have ceramic eyes on their edges, allowing the optical fiber 1, protective fiber bundle 2, and carbon fiber bundle 3 to come into contact with and rub against the ceramic material, thereby reducing friction on the optical fiber 1, protective fiber bundle 2, and carbon fiber bundle 3 and preventing snagging. Furthermore, the multiple upper wire feeding holes 1140 and multiple lower wire feeding holes are arranged along oblique paths that form an angle with the horizontal plane, such as... Figure 4 As shown.

[0112] In some embodiments, the curing and shaping device 14 is further provided with an auxiliary guide plate on its inlet side. The auxiliary guide plate has an auxiliary guide hole corresponding to the inlet of the shaping channel in the curing and shaping device 14. The diameter of the auxiliary guide hole is larger than the inner diameter of the shaping channel inlet, which allows the outer diameter of the preformed core rod composed of optical fiber 1, protective fiber bundle 2, carbon fiber bundle 3, and outer protective tape to gradually decrease, avoiding stress concentration caused by sudden diameter change, and also squeezing out excess adhesive to ensure curing effect. More specifically, there is one auxiliary guide hole, and its diameter remains unchanged in the moving direction of the preformed core rod; or, there are multiple auxiliary guide holes along the moving direction of the preformed core rod, and the diameters of the multiple auxiliary guide holes decrease sequentially along the moving direction of the preformed core rod; or, there is one auxiliary guide hole, and its diameter gradually decreases in the moving direction of the preformed core rod. In actual use, the outer protective tape and the preformed bundle enter the auxiliary guide hole together, and then enter the shaping channel.

[0113] In some embodiments, see Figure 1 The first impregnation device 12 has a heating device 23 at its outlet side for protective heating. This can be achieved by heating with resistance wires, with resistance wires positioned on both the upper and lower sides of the heating channel to ensure more uniform heating. More specifically, the heating device 23 has an insulation cover around its periphery to provide a relatively sealed heating space, improving heating reliability while reducing energy consumption.

[0114] In some embodiments, see Figure 2 and Figure 3 The pre-forming positioning device 13 includes a positioning plate 1310, on which a central channel 6 and an edge channel 7 are formed. More specifically, the sidewalls of the central channel 6 and the edge channel 7 are covered with a ceramic layer to reduce friction on the optical fiber 1, the protective fiber bundle 2, and the carbon fiber bundle 3, and to prevent snagging.

[0115] In some embodiments, the carbon fiber feeding unit 1130 described above can be adopted as follows: Figure 6 The structure shown. See also Figure 2The carbon fiber feeding unit 1130 includes a feeding shaft 1131, a brake ring 1132, a brake pad 1133, and a brake elastic element 1134. The brake ring 1132 is sleeved outside the feeding shaft 1131, and the brake pad 1133 is provided on the inner ring surface. The brake pad 1133 is in frictional contact with the feeding shaft 1131. The brake elastic element 1134 is connected between the outer ring surface of the brake ring 1132 and the frame of the feeding device 11 to provide an elastic preload force opposite to the rotation direction of the feeding shaft 1131. In a specific implementation, the brake elastic element 1134 is a spring, which is connected to the outer ring surface of the brake ring by a flexible rope 1135. A carbon fiber bundle 3 is wound onto the unwinding shaft 1131. Under the action of the drive device, the shaft rotates to release the carbon fiber bundle 3. In this embodiment, the release speed of the unwinding shaft 1131 is controlled by the friction between the brake pad layer 1133 and the unwinding shaft 1131, combined with the elastic force of the brake elastic element 1134. By reasonably controlling the traction speed, the third tension can be adjusted. It is understood that the greater the elastic restoring force provided by the brake elastic element 1134, the greater the rotational resistance to the unwinding shaft 1131, i.e., the greater the third tension. In this embodiment, existing tension sensor arrangements such as cantilever tension sensors can also be used to measure the third tension, which will not be elaborated further here.

[0116] In some embodiments, the curing and shaping device 14 described above may employ, for example... Figure 2 The structure shown. See also Figure 2 The curing and shaping device 14 includes a shaping heating mold 1410 and a curing mechanism 1420. The shaping heating mold 1410 forms a shaping channel, and the curing mechanism 1420 forms a curing channel.

[0117] In some embodiments, the first impregnation device 12 described above can be as follows: Figure 7 The structure shown. See also Figure 7 The first dipping device 12 includes a first dip tank 1210, a first dip roller 1220, a second dip roller 1230, and a dip pressure roller assembly 1240. The first dip tank 1210 is a V-shaped groove. The first dip roller 1220 is located above the inlet side of the first dip tank 1210. The second dip roller 1230 is located at the bottom of the first dip tank 1210 and forms a thread-passing space with the bottom of the tank. The dip pressure roller assembly 1240 is located above the outlet side, and a squeezing space is formed between the two pressure rollers of the dip pressure roller assembly 1240. Optical fiber 1, protective fiber bundle 2, and carbon fiber bundle 3 pass over the top of the first impregnation roller 1220 and enter the first glue tank 1210 downwards. They then pass through the fiber passage space below the second impregnation roller 1230. The second impregnation roller 1230 ensures that each filamentous structure is in full contact with the glue. After being impregnated, optical fiber 1, protective fiber bundle 2, and carbon fiber bundle 3 then enter the extrusion space of the impregnation pressure roller group 1240 to expel excess glue.

[0118] In some embodiments, see Figure 2 The production equipment for carbon fiber composite core rods with embedded optical fibers also includes a tape release device 18, which is used to collect the outer protective tape and release the outer protective tape according to production needs. After curing and shaping, the outer protective tape forms the outer protective layer 10.

[0119] In some embodiments, see Figure 2 The outlet side of the tape feeding device 18 is also provided with a second impregnation device to apply the impregnated outer protective tape to the outer periphery of the carbon fiber bundle layer.

[0120] In some embodiments, see Figure 5 The fiber optic cable laying unit 1110 has a disconnection alarm mechanism, which includes a signal transmitter 1111, a signal receiver 1112, and a disconnection triggering component 1113. The signal transmitter 1111 and the signal receiver 1112 are arranged opposite to each other. The disconnection triggering component 1113 is connected to the signal transmitter 1111 or the signal receiver 1112 via a rope, and can be attached to the fiber optic cable 1. The disconnection triggering component 1112 has a blocking state that blocks the signal path between the signal transmitter 1111 and the signal receiver 1112, and a conducting state that allows the signal path to be opened. Figure 5 The dashed line in the diagram shows the signal path. If fiber 1 breaks, the breakage trigger mechanism 1113 drops, and the signal path changes from an blocked state to a conductive state, enabling automatic detection of the continuity of fiber 1.

[0121] In some embodiments, see Figure 1 The fiber-embedded carbon fiber composite mandrel production equipment also includes a first drying device 19 for pre-drying, which is located on the outlet side of the fiber feeding device 11. It should be understood that although the first drying device 19 in this embodiment mainly dries the carbon fiber bundle 3, the optical fiber 1 and the protective fiber bundle 2 also pass through the drying channel of the first drying device 19 together with the carbon fiber bundle 3 during use.

[0122] In some embodiments, see Figure 2 A transition roller frame 20 is also provided between the first drying device 19 and the fiber feeding device 11. The transition roller frame 20 has multiple transition rollers arranged sequentially in the vertical direction. The rotation axis of the transition rollers is perpendicular to the fiber feeding direction to support the optical fiber 1, protect the fiber bundle 2 and the carbon fiber bundle 3, and prevent them from sagging. The support height can be adjusted by selecting transition rollers of different heights.

[0123] In some embodiments, see Figure 2 , Figure 8 and Figure 9The fiber-optic composite mandrel production equipment also includes a fiber splitting device 21. The fiber splitting device 21 includes a fiber splitting guide roller 2110 and a fiber splitting grid 2120 disposed above the fiber splitting guide roller 2110. An intermediate channel 8 and a side channel 9 are formed between adjacent fiber splitting grids 2120. In specific implementation, the fiber splitting guide roller 2110 is fixed and does not rotate, and the fiber splitting grid 2120 is fixed on the upper part of the fiber splitting guide roller 2110.

[0124] In some embodiments, feature A above may be adopted as follows: Figure 2 The structure shown. See also Figure 2 To achieve secondary drying, the fiber-embedded carbon fiber composite mandrel production equipment also includes a second drying device 22, which is located on the outlet side of the fiber splitting device 21. It should be understood that although the second drying device 22 in this embodiment mainly dries the carbon fiber bundle 3, the optical fiber 1 and the protective fiber bundle 2 also pass through the drying channel of the second drying device 22 together with the carbon fiber bundle 3 during use.

[0125] It should be noted that the above-mentioned devices can be installed together on the same main frame or separately; there is no single limitation here.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a carbon fiber composite core rod with embedded optical fiber, characterized in that, Includes the following steps: S100. Release the optical fiber with a first tension, release the protective fiber bundle with a second tension, and release multiple carbon fiber bundles with a third tension, wherein the second tension is greater than the first tension, and the first tension is greater than the third tension; S200, Impregnate the optical fiber, the protective fiber bundle, and the multiple bundles of the carbon fiber bundle with resin; S300, the optical fiber, the protective fiber bundle, and at least one of the carbon fiber bundles are passed through the central channel, and the remaining multiple carbon fiber bundles are passed through multiple edge channels respectively. The multiple edge channels are evenly distributed around the central channel, and the protective fiber bundle forms a protective fiber bundle layer on the outer periphery of the optical fiber, and the carbon fiber bundles form a carbon fiber bundle layer on the outer periphery of the protective fiber bundle layer. S400: The optical fiber, the protective fiber bundle, and the carbon fiber bundle are cured and shaped. The procedure preceding step S200 also includes: The optical fiber and the protective fiber bundle are passed through the central channel, and multiple carbon fiber bundles are passed through multiple side channels respectively. The central channel and the multiple side channels are all located on the same horizontal plane, and the multiple side channels are symmetrically arranged about the central channel.

2. The method for producing a carbon fiber composite core rod with implanted optical fiber as described in claim 1, characterized in that, Step S400 specifically includes: S410. Bundle the optical fiber, the protective fiber bundle, and the carbon fiber bundle together to obtain a preformed bundle; S420. Wrap the outer periphery of the preformed bundle with an impregnated outer protective strip to obtain a preformed core rod; S430. The preformed mandrel is heated and cured to obtain a carbon fiber composite mandrel.

3. The method for producing a carbon fiber composite core rod with implanted optical fiber as described in claim 2, characterized in that, Step S430 specifically includes: S431. The preformed mandrel is introduced into the shaping channel for shaping and heating. S432. The pre-formed mandrel that has been shaped and heated is introduced into the curing channel for curing and heating to obtain a carbon fiber composite mandrel.

4. The method for producing a carbon fiber composite core rod with implanted optical fiber as described in claim 1, characterized in that, The procedure preceding step S200 also includes: The carbon fiber bundles are pre-dried.

5. The method for producing a carbon fiber composite core rod with implanted optical fiber as described in claim 4, characterized in that, The procedure prior to step S300 also includes: The carbon fiber bundles are dried a second time; The optical fiber, the protective fiber bundle, and the multiple bundles of carbon fiber that have undergone secondary drying are impregnated with resin.

6. The method for producing a carbon fiber composite core rod with implanted optical fiber as described in claim 1, characterized in that, The procedure prior to step S300 also includes: The optical fiber, the protective fiber bundle, and the multiple bundles of carbon fiber are subjected to protective heating.

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