A low-deflection composite material electric pole and a forming process thereof

Abstract

The application discloses a kind of low deflection composite material electric pole and its forming process, it is related to fiber reinforced composite material forming technical field.Electric pole is conical rotary body, by inner lining, structural reinforcement layer and outer protective layer constitute, inside is equipped with integrated Y type three prong through reinforcing rib, with pole body through resin matrix integrated solidification forming, deflection span ratio under rated load is less than or equal to 7 / 100.Forming core mould is made of three independent sectoral petal and is spliced, and there is no center connecting shaft between petal, no internal tensioning mechanism, only through two ends external clamping positioning, cavity surface is provided with rib position groove for preloading reinforcing rib.Forming process includes core mould splicing, reinforcing rib preloading, inner and outer layer winding, solidification and natural loosening demoulding and the like steps.The application realizes the integrated forming of reinforcing rib and pole body, greatly improves pole body rigidity, core mould structure is extremely simple, demoulding is efficient, yield is high, suitable for the conical composite material pole body large-scale production in the fields such as power transmission, communication etc..

Description

Technical Field

[0001] This invention relates to the field of fiber-reinforced resin matrix composite material molding and manufacturing technology, specifically to a low-deflection tapered composite material pole for use in overhead power transmission lines and communication base station lines, as well as a matching integral winding molding process and a three-lobed mandrel device; in particular, it relates to a three-lobed independent mandrel structure without internal connecting mechanisms and without central support, and an integrated winding molding method based on the mandrel, which can realize high-precision, high-efficiency, and low-defect mass production of large-taper composite material poles. Background Technology

[0002] Traditional power transmission and communication poles are mainly prestressed concrete poles, which have long dominated the market due to their low cost and mature technology. However, with the improvement of power grid construction standards and the increasing demand for complex operating conditions, the inherent defects of concrete poles have become increasingly prominent: First, they are heavy; a typical 12-meter tapered concrete pole weighs over 1.2 tons, making transportation and hoisting in mountainous and hilly areas difficult and costly. Second, they are brittle, with poor impact and earthquake resistance, and are prone to fracture failure under extreme loads such as typhoons and icing. Third, they have weak corrosion resistance; in coastal saline-alkali areas and high-humidity industrial areas, the reinforcing steel is prone to corrosion and expansion, leading to pole cracking, and their service life is usually only 15-20 years. Although steel pipe poles have higher strength, they have problems such as heavy weight, high cost of corrosion protection and maintenance, low-temperature brittleness, and susceptibility to theft, making them difficult to adapt to the needs of all application scenarios.

[0003] With the development of composite material technology, fiber-reinforced resin matrix composite (FRP) poles have been gradually promoted and applied in power distribution lines and communication pole systems due to their outstanding advantages such as high specific strength, corrosion resistance, excellent insulation, and light weight (only 1 / 9 to 1 / 7 of that of concrete poles of the same specifications). However, the molding technology and structural design of existing composite material poles still have many industry bottlenecks, especially in the field of large-tapered tapered poles, where a mature and reliable large-scale mass production solution has not yet been formed. The specific shortcomings are as follows:

[0004] First, the pole stiffness is insufficient, making it difficult to meet high standards for deflection control. Existing composite material poles are mostly produced using a conical mold winding process, resulting in poor longitudinal strength continuity and low overall bending stiffness. Under rated wind loads, the deflection at the pole tip generally exceeds 13 / 100 of the pole length, and the deformation further increases under strong typhoon conditions, easily leading to safety hazards such as line flashover and hardware detachment, failing to meet the State Grid's high standards for pole deflection in strong wind areas. Although the industry has attempted to increase stiffness by increasing wall thickness, this significantly increases material costs and pole weight, contradicting the core advantage of lightweight composite materials.

[0005] Secondly, the internal reinforcing structure is difficult to mold, and the interface bonding strength is insufficient. To improve the longitudinal stiffness of the rod, some solutions propose to set reinforcing ribs inside the rod. However, traditional molding mandrels are either integral or segmented mandrels with internal tensioning mechanisms. The internal space of the mandrel is completely occupied by components such as the central shaft, support frame, and tensioning cylinder, making it impossible to pre-embed an integral through-type reinforcing rib. If the reinforcing rib is added by pasting after molding, the reinforcing rib is only bonded to the inner wall of the rod by adhesive, resulting in low interfacial shear strength. Under long-term alternating loads, delamination and detachment are likely to occur, failing to effectively enhance the stiffness of the reinforcing rib.

[0006] Third, the mold structure is complex, resulting in high manufacturing and maintenance costs. Existing molding dies for tapered composite material poles mainly fall into two categories: one is a two-part split mold. For products with large tapers and large diameters, the resin shrinkage after curing causes the product to tightly grip the mold's tapered surface, creating significant demolding resistance. Forced demolding can easily scratch the inner wall of the product or even cause the pole to crack, resulting in a low yield. The other type is a three-part core mold with a central shaft. Demolding is achieved by driving the expansion and contraction of the parts through an internal tensioning mechanism. However, this structure requires numerous complex components such as a central tie rod, hydraulic tensioning unit, and internal support frame. The manufacturing cost is 2-3 times that of the two-part mold, and the internal moving mechanism is prone to wear and has a high failure rate, making daily maintenance difficult and costly. Furthermore, the internal mechanism leaves obvious mold-closing steps and mechanism marks on the inner wall of the product, resulting in poor inner wall molding quality and affecting the product's mechanical uniformity and corrosion resistance. A long-standing technical bias within the industry—that "segmented tapered core molds must be equipped with internal tensioning support mechanisms to withstand winding tension"—has prevented the fundamental simplification of the mold structure.

[0007] Fourth, production efficiency is low, making it difficult to meet the needs of large-scale supply. The demolding process of traditional three-part molds with internal mechanisms is cumbersome. It is necessary to first disassemble the end connecting mechanism and retract the internal tensioning device, and then separate and pull out the mold piece by piece. The demolding time for a single pole can be as long as 2 to 4 hours, and product damage is easy to occur, with an overall yield rate of less than 80%. At the same time, the long mold assembly and disassembly time and the long production cycle of a single mold make it difficult to match the large-volume, short-cycle supply needs of power grid projects.

[0008] Furthermore, existing winding processes lack precise load matching for the layup design of tapered poles, mostly employing uniform wall thickness or simple variable wall thickness designs. This results in insufficient stiffness redundancy in the bending moment resistance region at the large end and significant material waste at the small end, failing to achieve the optimal balance between low deflection and lightweight design. Currently, no perfect solution exists that can achieve both high stiffness and low deflection in poles, while also providing a simple mold and efficient demolding process. The industry urgently needs to develop a composite material pole molding technology that combines excellent mechanical properties, a simple mold structure, and efficient mass production capabilities to overcome current industry development bottlenecks. Summary of the Invention

[0009] To address the aforementioned shortcomings of existing technologies, the core objective of this invention is to provide a low-deflection composite material pole and its molding process, achieving systematic innovation in three dimensions: product structure, mold design, and molding process, thereby solving the following technical problems:

[0010] 1. Solve the technical problems of insufficient stiffness, large deflection, and excessive deformation under strong wind conditions of existing tapered composite material poles, and achieve low deflection characteristics with a deflection-to-span ratio of ≤7 / 100 under rated load;

[0011] 2. Solve the problems of difficulty in integral molding of built-in reinforcing ribs and low interface bonding strength, and achieve complete integration of through-type reinforcing ribs with the rod body;

[0012] 3. Break through the industry's technical prejudice that "segmented molds must have internal support", solve the problems of complex structure, space occupied by internal mechanisms, and high manufacturing cost of traditional segmented molds, and create a minimalist three-lobed core mold without central connection and internal mechanism;

[0013] 4. Solve the problems of difficult demolding, low demolding efficiency, and low yield of large-taper composite material poles by utilizing the curing shrinkage characteristics to achieve natural loosening and rapid demolding;

[0014] 5. Achieve simultaneous improvement in product mechanical properties and production efficiency, form a mature process solution that can be scaled up and promoted, and meet the high-standard application requirements of power grid and communication engineering.

[0015] To achieve the above-mentioned objectives, the present invention is implemented through the following technical solution:

[0016] (I) Low-deflection composite material pole structure

[0017] The low-deflection composite material pole of the present invention is an integral conical rotating body structure with a larger diameter at the larger end than at the smaller end and a taper range of 1:75 to 1:40. The pole body includes an inner lining layer, a structural reinforcement layer and an outer protective layer from the inside to the outside. The pole body is provided with an integral three-pronged (Y-shaped) through-branch reinforcing rib. The reinforcing rib and the pole body wall are integrally cured and formed by resin matrix, without splicing interface and secondary bonding interface.

[0018] To quantify the low-deflection design principle, based on the bending mechanics model of a cantilever beam, the deflection at the top of the beam can be calculated using the following formula:

[0019]

[0020] In the formula: The deflection at the top of the rod is in mm. The effective length of the pole is in mm. Distance from root end Bending moment at the cross section, in N·mm; E is the longitudinal elastic modulus of the composite material structural layer, in MPa; Distance from root end Equivalent moment of inertia at the cross section, in mm 4 .

[0021] For a hollow conical rod, its moment of inertia of the tube wall section for:

[0022]

[0023] In the formula: for Outer diameter of the rod at the cross-section, in mm; for The structural layer wall thickness at the cross-section, in mm.

[0024] Moment of inertia of composite section with built-in three-pronged stiffener Calculated based on the parallel axis shifting formula:

[0025]

[0026] In the formula: The moment of inertia of a single rib about its own centroidal axis, in mm. 4 ; The cross-sectional area of ​​a single rib is expressed in mm². The distance from the center of the airfoil to the central axis of the rod is in mm.

[0027] The total equivalent moment of inertia of the rod is Under the same bending moment load, stiffeners can increase the moment of inertia of the section by more than 40%, thereby significantly reducing the top deflection and achieving the design goal of deflection-to-span ratio ≤ 1 / 150.

[0028] Furthermore, the inner lining is made of glass fiber surface felt or chopped fiber felt impregnated with resin and wound, with a thickness of 0.5~2mm and a resin content of 60%~70% by mass. The inner lining has high density and can block the penetration of external water vapor and saline-alkali media, thereby improving the corrosion resistance of the inner wall of the rod.

[0029] The structural reinforcement layer is formed by continuously reinforcing fibers impregnated with resin and wound at a designed angle, employing a gradient wall thickness design. The wall thickness at the larger end is 8~25mm, and at the smaller end it is 4~12mm. The wall thickness transitions linearly along the axial direction, precisely matching the bending moment distribution pattern of the pole. For cantilever poles subjected to uniformly distributed wind loads, the bending moment distribution pattern along the axial direction is as follows: ,in To achieve uniform wind load linear density, this invention employs a linear gradient wall thickness design, with the wall thickness varying along the axial direction as follows:

[0030]

[0031] In the formula: The thickness of the structural layer at the small end is in mm. The unit is the wall thickness of the structural layer at the larger end, in mm. This design ensures that the bending capacity of each section of the rod is positively correlated with the bending moment distribution, achieving optimal material usage while meeting stiffness requirements.

[0032] The reinforcing fibers can be one or more of alkali-free glass fiber, carbon fiber, and basalt fiber, or a mixture thereof. The ply angle system includes 0° longitudinal ply, ±45° diagonal ply, and 90° circumferential ply. The 0° longitudinal ply accounts for 40%–60% of the total ply and primarily bears bending loads, improving the longitudinal stiffness of the pole. The ±45° diagonal ply accounts for 25%–40% and primarily bears shear and torsional loads, improving impact resistance. The 90° circumferential ply accounts for 10%–20% and primarily bears radial loads, improving the pole's resistance to flattening and its clamping effect. Through the optimized combination of multiple ply angles, the optimal configuration of the pole's mechanical properties is achieved.

[0033] The outer protective layer is made of weather-resistant resin matrix with added ultraviolet absorbers and antioxidants, with a thickness of 0.3~1mm. It can effectively resist outdoor ultraviolet aging and damp heat aging, ensuring that the mechanical properties of the pole are retained at no less than 80% within a 30-year service life.

[0034] The integrated three-pronged reinforcing rib has a Y-shaped cross-section, with three rib wings evenly distributed circumferentially, and adjacent rib wings having an included angle of 120°. The reinforcing rib runs the entire length of the pole's axial direction, and the ends of the rib wings are completely fused with the inner wall of the pole. The reinforcing rib is made of fiber-reinforced composite material with the same resin system as the pole's structural layers, ensuring interfacial compatibility and bonding strength. The cross-sectional area of ​​the reinforcing rib decreases linearly from the larger end to the smaller end along the axial direction, matching the axial bending moment distribution of the pole, thus maximizing the pole's stiffness while achieving a lightweight design.

[0035] Mechanical verification shows that under standard rated bending moment load, the ratio of the pole top deflection to the pole length is no greater than 7 / 100, which is significantly better than the 13 / 100 required by the power industry standard, demonstrating excellent low deflection characteristics and typhoon resistance.

[0036] (ii) Three-lobed molding core mold structure

[0037] The three-lobed mandrel used for molding the aforementioned composite material poles is composed of three independent fan-shaped lobes evenly divided along the axial direction. The three lobes have no central connecting shaft, no tie rods, no internal tensioning mechanism, and no internal connecting skeleton; they are formed solely by the tight fit of their mating surfaces to create a complete conical rotary cavity. The mandrel is conical in shape, with its outer surface serving as the pole molding cavity surface. Positioning, clamping, and rotational drive at both ends of the mandrel are achieved solely through external clamping mechanisms.

[0038] The stable winding of the mandrel in this invention relies on a "dual-force constraint balance mechanism," the mechanical equilibrium conditions of which are as follows: during the winding process, the fiber bundle applies a circumferential clamping force to the mandrel. for:

[0039]

[0040] In the formula: The total number of fiber bundles simultaneously wrapped; The tension of a single fiber bundle is expressed in nanometers (N). The fiber winding angle is expressed in degrees (°).

[0041] The circumferential clamping force acting on the surface of the conical valve body will generate a component force that causes the valve body to slide axially. :

[0042]

[0043] In the formula: The half-cone angle of the core mold taper, in degrees.

[0044] Clamping force provided by the end clamping chuck Static friction is generated at the contact surface. Used to balance the axial slip component:

[0045]

[0046] In the formula: The static friction coefficient between the chuck and the mandrel stop is given.

[0047] The mechanical conditions for stable entanglement are: Where k is the safety factor, ranging from 1.5 to 2.0. By matching the clamping force and the winding tension, stable rotation of the three-lobed body can be achieved without internal support. This is the core mechanical basis for overcoming the technical bias that "the lobed mold must have internal support" in this invention.

[0048] Furthermore, the central angle of each of the aforementioned fan-shaped petals is 120°, and the three petals are joined together to form a complete 360° conical cylinder. The joining surface of the petals is a straight surface along the axial direction or a small-angle inclined surface of 1°~3°. The joining surface is provided with a stepped stop sealing structure, so that there are no radial steps or undercut structures after joining, ensuring that the petals can be naturally released radially after curing without any jamming resistance, while preventing resin from seeping inward. The joining surface is precision machined with a flatness of ≤0.05mm, and the gap after joining is ≤0.03mm, avoiding obvious mold marks on the inner wall of the rod after molding.

[0049] The valve body is a hollow, thin-walled, reinforced structure. The inner side is a smooth, reinforced curved surface with axial reinforcing ribs to ensure the valve body's rigidity and prevent deformation during winding. The outer side of the valve body is a high-precision polished cavity surface with a surface roughness Ra≤0.8μm to ensure the smoothness of the inner wall of the product. Three shallow rib grooves are provided on the cavity surface, running axially. These three grooves are evenly distributed 120° circumferentially, their positions corresponding one-to-one with the three rib wings of the triangular reinforcing rib, used for pre-installing and positioning the axial reinforcing ribs. The depth of the grooves is 1 / 3 to 1 / 2 of the reinforcing rib thickness, and the width matches the width of the reinforcing rib rib wings, ensuring that after installation, the reinforcing rib is partially embedded in the groove for positioning and partially protrudes from the cavity surface, allowing for full wetting and fusion with the subsequently wound structural layers.

[0050] The three petals have the same axial length, flush end faces, and annular locating stops and clamping flanges on their outer circumferences. The flanges have ejection pull-out fixing holes for circumferential positioning and synchronous clamping with external clamping chucks, and are also compatible with ejection tooling connections. The coaxiality of the locating stops is ≤0.1mm, ensuring that the radial runout during core mold rotation meets the winding accuracy requirements. The petals can be made of aluminum alloy, cast steel, or fiberglass, with a hard anodized or chrome-plated surface treatment, providing high hardness, high gloss, and excellent ejection performance.

[0051] The core innovation of this core mold lies in completely eliminating all internal connecting and supporting mechanisms, relying solely on the external clamping forces at both ends and the fiber tension during the winding process to maintain the overall shape. This not only greatly simplifies the mold structure and reduces manufacturing costs, but also completely frees up the internal space of the core mold, providing installation conditions for the built-in integrated reinforcing ribs, while eliminating the influence of internal mechanisms on the molding of the inner wall of the product from the root.

[0052] The "conical shrinkage force principle" of the demolding process can be explained through mechanical decomposition: the volume shrinkage rate of the cured resin is... After curing, the uniform radial clamping pressure exerted by the inner wall of the pole on the mandrel is p, and the normal resultant force of the clamping force per unit length is... Acting on the conical surface, it can be decomposed into a radial component. axial component :

[0053]

[0054] radial component The three valves are pushed to contract towards the center, causing the outer surface of the valve to automatically separate from the inner wall of the rod, forming a 1-2mm demolding gap. Natural release can be achieved without an additional diameter reduction mechanism.

[0055] (III) Composite Material Pole Winding Molding Process

[0056] The low-deflection composite material pole winding molding process based on the above-mentioned three-lobed mandrel specifically includes the following steps:

[0057] Step 1: Mold pretreatment and assembly

[0058] Clean the cavity surfaces and mating surfaces of the three fan-shaped petals with an organic solvent to remove oil, residual resin, and impurities. After the solvent evaporates, evenly spray 1-2 coats of semi-permanent release agent, with an interval of 10-20 minutes between each coat. Allow the sprayed petals to air dry at room temperature for 20-40 minutes. Align the three dried petals circumferentially on the assembly fixture, precisely positioning them using stepped stops. Adjust the axial position of each petal to ensure that both end faces are flush and the misalignment is ≤0.5mm. After assembly, check the gaps between the mating surfaces to ensure that the gaps are ≤0.03mm along the entire axial direction, forming a complete conical core mold.

[0059] Step 2: Pre-installation of reinforcing ribs

[0060] Slowly insert the prefabricated one-piece three-pronged reinforcing rib along the axial direction from the large end of the core mold, so that the three rib wings are respectively embedded in the corresponding rib grooves on the cavity surface; during the insertion process, keep the reinforcing rib coaxial with the core mold to avoid scratching the mold release agent on the cavity surface; adjust the axial position of the reinforcing rib so that its two ends extend 30~80mm beyond the end face of the core mold, and use high temperature resistant tape to temporarily fix the two ends to prevent axial movement or circumferential displacement during the winding process, and fill the joint between the rib wings and the groove with resin-based anti-torsion filler to enhance the interface bonding force.

[0061] Step 3: Core mold clamping and positioning

[0062] The assembled mandrel is hoisted to the two spindle positions of the CNC winding machine. The coaxiality of the mandrel is adjusted so that the radial runout of the entire axis is ≤0.2mm. Then, the special clamping chucks at both ends are activated to clamp and fix the positioning stops and flanges at both ends of the mandrel synchronously. The clamping chucks adopt a three-jaw self-centering structure or a ring clamping structure. The clamping force at the large end is set to 5~15kN and the clamping force at the small end is set to 3~10kN to ensure that the three parts do not rotate relative to each other or separate radially during rotation, and maintain a tight fit.

[0063] Step 4: Inner lining layer winding

[0064] Start the winding machine and set the mandrel speed to 5-15 r / min. Prepare the inner liner using a circumferential winding method. Pre-impregnate the fibers with the prepared resin solution, controlling the viscosity of the solution to 200-500 mPa·s (25℃) to ensure that the resin fully wets the fibers and adheres tightly to the cavity surface. Control the winding tension to 3-8 N / bundle to avoid excessive tension that would thin the inner liner. Stop winding the inner liner after it reaches the designed thickness and allow it to gel at room temperature for 30-60 minutes to allow the resin to reach the B-stage state, preventing the inner liner from being squeezed and displaced during subsequent structural layer winding.

[0065] Step 5: Structural reinforcement layer winding

[0066] After the inner liner layer is gelled, the structural reinforcement layer is wound. Based on the stress analysis of the pole, a layup program is pre-set, and a multi-axis linkage winding machine is used for a combination of helical and circumferential winding. The 0° longitudinal layer, ±45° oblique layer, and 90° circumferential layer are laid sequentially according to the design order. During the winding process, a gradient tension control strategy is adopted, with the inner layer winding tension at 10~15N / bundle, gradually increasing to 20~30N / bundle for the outer layer to compensate for curing shrinkage stress. The yarn feed speed is dynamically adjusted according to the mandrel diameter to ensure that the winding angle deviation of each layup is ≤±1°, while simultaneously achieving a design gradient distribution of layup thickness at the large and small ends. During the winding process, fiber tension applies a uniform clamping force to the mandrel along the circumference, and the clamping force gradually increases with the number of layups. This clamping force, together with the clamping force of the chucks at both ends, forms a stable spatial constraint system, ensuring that the three independent petals maintain a tightly fitted overall shape under high-speed rotation, completely eliminating the need for internal support mechanisms.

[0067] Step 6: Curing and Shaping

[0068] After the structural layer is wound, a release liner can be wound around the outermost layer of the rod. Then, the entire mandrel containing the product is sent into a curing oven for heating and curing according to a preset temperature-time curve. The curing process curve can be adjusted according to the resin system. A typical epoxy resin curing curve is as follows: heat to 80°C at a rate of 1~2°C / min, hold for 2 hours for initial shaping; then heat to 120°C at a rate of 1°C / min, hold for 4 hours for complete curing; after holding, cool to below 40°C in the oven before removing from the oven. During the curing process, the mandrel can be placed on a rotating support and rotated at a low speed of 0.5~2 r / min to avoid uneven wall thickness and missing resin defects caused by gravity dripping, ensuring uniform wall thickness of the rod. For room temperature curing resin systems, the product can be left to cure at room temperature after winding, without needing to be placed in an oven, further reducing production energy consumption. For thick-walled products, steam internal curing can be used to improve curing uniformity.

[0069] Step 7: Demolding

[0070] After curing and cooling to room temperature, the core mold is clamped in the demolding station, and the clamping force of the chucks at both ends is simultaneously released. Due to volume shrinkage during resin curing, the inner wall of the pole exerts a radial clamping force on the core mold. Under the action of the component force of the conical surface, the three fan-shaped petals automatically loosen radially inward and naturally separate from the inner wall of the pole, forming a gap of 1-2 mm. Subsequently, the demolding butterfly holes of the end flanges are connected to the traction fixture, and the three petals are axially pulled out from both ends of the pole, thus completing the demolding. The demolding process does not require diameter reduction or disassembly of any internal mechanisms; the three petals are pulled out independently without interference. For extra-long or large-diameter poles, a mechanically assisted demolding trolley can be used to improve work efficiency and safety.

[0071] Step 8: Post-processing and inspection

[0072] After demolding, the poles undergo edge trimming at both ends and surface grinding to ensure flat end faces and smooth appearance. Then, they are inspected according to the corresponding industry standards for dimensional deviation, appearance quality, mechanical properties, corrosion resistance, etc. Once qualified, they become finished low-deflection composite material poles.

[0073] This invention achieves several significant technological advancements through synergistic innovation in product structure, mold design, and molding process, with the following specific beneficial effects:

[0074] 1. Significantly improved mechanical properties, with industry-leading low-deflection characteristics.

[0075] This invention employs a structural design combining an integrated three-pronged through-type reinforcing rib with gradient optimized layup. The reinforcing rib is integrally cured with the pole body, eliminating interface defects and increasing the pole's moment of inertia by over 40%, significantly improving its longitudinal bending stiffness. Combined with a gradient wall thickness designed according to bending moment distribution, a precise match between strength and stiffness is achieved. Under the same pole weight, the overall bending strength of this invention's pole is more than 30% higher than conventional composite material poles, and the top deflection under rated load is reduced by more than 40%, with a deflection-to-span ratio ≤1 / 150, far exceeding industry standards. It possesses excellent typhoon resistance and deformation resistance, meeting the high-standard usage requirements of coastal areas with strong winds and high icing.

[0076] 2. The mold structure is extremely simple, significantly reducing manufacturing costs and maintenance difficulty.

[0077] The three-lobed core mold of this invention completely eliminates all complex internal components such as the central shaft, tie rods, tensioning mechanism, and internal skeleton, consisting only of three independent lobes. This reduces the number of mold parts by over 70% and manufacturing costs by over 50%. Simultaneously, the mold has no easily damaged internal moving mechanisms, resulting in a long service life. Routine maintenance only requires cleaning the mating surfaces and cavity surfaces, reducing maintenance costs by over 60%, significantly lowering equipment investment and maintenance costs for enterprises. This solution breaks through the industry's technical prejudice that "segmented molds must have internal support," demonstrating outstanding and substantial innovation.

[0078] 3. Easy and efficient demolding, significantly improving yield and production efficiency.

[0079] This invention utilizes the resin curing shrinkage characteristics and the principle of conical surface mating. After curing, the petal body naturally loosens and can be directly pulled out axially for demolding. There is no need to disassemble the internal mechanism or force the diameter to be reduced. The demolding time of a single pole is shortened from the traditional 2-4 hours to 15-30 minutes, and the demolding efficiency is increased by more than 5 times. At the same time, there is no forced external force during the demolding process, which avoids defects such as scratches and cracks on the inner wall of the product. The product yield can be increased from about 80% to more than 98%, which is very suitable for large-scale mass production.

[0080] 4. High-quality inner wall molding and strong structural integrity.

[0081] The core mold of this invention has no internal structural interference, the cavity surface is a continuous smooth curved surface, the splicing gap is extremely small and a sealing stop is set. After molding, the inner wall of the pole has no obvious mold-closing steps and no structural traces. The inner wall roughness Ra≤3.2μm, and the mechanical uniformity is good. At the same time, it can realize the built-in molding of the integrated three-pronged reinforcing rib. The reinforcing rib is completely integrated with the pole body, with no splicing or pasting interface. The overall structural continuity is far superior to the traditional splicing pole or post-glued reinforcing rib solution, and the long-term durability is stronger.

[0082] 5. Strong process compatibility and outstanding industrial application value.

[0083] This process is compatible with various resin systems such as epoxy resin, polyurethane resin, unsaturated polyester resin, and vinyl ester resin, and is also compatible with various reinforcing fibers such as glass fiber, carbon fiber, and basalt fiber. It can produce various tapered composite material poles, communication poles, and lighting poles with taper ratios of 1:75 to 1:40 and lengths of 6 to 30 meters. Furthermore, the three-part mold forming principle can also be applied to the molding of other large-tapered, large-diameter composite material rotating parts. The lightweight design reduces carbon emissions during transportation, and the long lifespan reduces resource consumption throughout the entire life cycle, aligning with green and low-carbon development guidelines. It meets the needs of major national projects such as smart grids and disaster prevention and mitigation, possessing broad industrial application value and promising prospects for promotion. Attached Figure Description

[0084] Figure 1 This is a schematic diagram of the overall structure of the low-deflection composite material pole described in this invention;

[0085] Figure 2 This is a schematic diagram of a Y-shaped reinforcing rib structure.

[0086] Figure 3 This is a flowchart of the composite material pole winding molding process described in this invention. Detailed Implementation

[0087] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art should know that the parameters, raw materials and process steps disclosed in the following embodiments are preferred specific implementations of the present invention. Those skilled in the art can make adjustments and substitutions based on the technical solutions of the present invention according to actual needs, and all such adjustments and substitutions should fall within the scope of protection of the present invention.

[0088] Example 1

[0089] This embodiment is a 12-meter-long low-deflection composite material pole for power distribution networks. It is prepared using an epoxy resin system and a heat curing process, along with the three-lobed core mold and integral winding molding process described in this invention. This is a typical implementation of this invention.

[0090] 1. Structure of utility pole products

[0091] like Figure 1 As shown, the composite material pole in this embodiment is a conical body of revolution with a diameter of φ350mm at the large end and φ190mm at the small end, a taper of 1:75, and a total length of 12m. The pole consists of an inner lining layer, a structural reinforcement layer, and an outer protective layer from the inside out. An integrated three-pronged reinforcing rib is provided inside the pole, running the entire length axially and integrally cured with the pole body.

[0092] The inner lining is made of alkali-free glass fiber surface felt (30g / ㎡) impregnated with bisphenol A type epoxy resin and wound, with a thickness of 1mm and a resin content of 65%. This layer has high density and can effectively block the penetration of soil, water vapor and saline-alkali media, thereby improving the corrosion resistance of the inner wall of the pole.

[0093] The structural reinforcement layer is formed by impregnating epoxy resin with alkali-free E-glass fiber roving (2400 tex). The wall thickness is 12 mm at the large end and 6 mm at the small end, with the wall thickness transitioning linearly along the axial direction. The layup scheme is optimized based on finite element stress analysis. The specific layup sequence from the inside out is as follows: 90° circumferential layer (1 layer), 0° longitudinal layer (3 layers), +45° diagonal layer (2 layers), -45° diagonal layer (2 layers), 0° longitudinal layer (2 layers), and 90° circumferential layer (1 layer). Calculations show that the 0° longitudinal layer accounts for 52% and mainly bears bending loads; the ±45° diagonal layer accounts for 35% and mainly bears shear and torsional loads; and the 90° circumferential layer accounts for 13% and mainly bears radial loads. This layup combination can fully utilize the performance advantages of fibers at each angle to achieve the optimal stiffness-to-weight ratio.

[0094] The outer protective layer is an epoxy resin layer with a thickness of 0.5mm, containing 2% UV absorber UV-531 and 0.5% antioxidant 1010. This layer can effectively absorb ultraviolet rays, delay resin aging, and ensure the performance stability of the pole for long-term outdoor use.

[0095] The integrated three-pronged stiffener has a Y-shaped cross-section, with three flanges evenly distributed circumferentially, and adjacent flanges having an included angle of 120°. The stiffener's cross-sectional dimensions change linearly along the axial direction: the flange width at the larger end is 30mm and the thickness is 8mm, while the flange width at the smaller end is 15mm and the thickness is 4mm, perfectly matching the axial bending moment distribution of the rod, thus improving stiffness while avoiding material waste. The stiffener is made using the same epoxy resin matrix and glass fiber prepreg as the structural layer, ensuring a perfect bond with the rod interface and eliminating the risk of delamination.

[0096] Based on the formula calculation, the equivalent moment of inertia of the pole's large end section in this embodiment is 1.87 × 10⁻⁶. 8 mm 4 Compared to poles of the same wall thickness without reinforcing ribs, this represents a 46.2% improvement. According to tests conducted by a third-party organization in accordance with GB / T23147 standards, the pole in this embodiment exhibits a top deflection of 72mm and a deflection-to-span ratio of 1 / 166.7 under a rated bending moment of 12kN·m, which is far superior to the industry standard requirement of 1 / 100. The pole's breaking moment can reach 36kN·m, with a safety factor of 3.0, meeting the requirements for 10kV distribution network lines in areas experiencing a Category 12 typhoon.

[0097] 2. Three-lobed core mold structure

[0098] The three-lobed core mold used to form the pole in this embodiment is composed of three independent fan-shaped lobes 5 with a central angle of 120°. There are no internal connecting components between the three lobes, and they are formed into a complete conical cylinder by the close contact of the splicing surfaces.

[0099] Each fan-shaped petal is cast from 6061 aluminum alloy and precision machined on a five-axis machine tool. The overall shape is a 120° fan-shaped cone with a total axial length of 12.2m and 100mm clamping allowance at each end. The outer side of the petal is a high-precision polished cavity surface 53 with a surface roughness Ra≤0.8μm. The taper of the cavity surface is consistent with the inner taper of the pole, which is 1:75. There are three shallow rib grooves running through the cavity surface along the axis. The rib grooves are evenly distributed at 120° around the circumference, with a groove depth of 3mm and a groove width of 30mm. The grooves are precisely matched with the dimensions of the three-pronged reinforcing ribs and are used for the installation and positioning of the reinforcing ribs.

[0100] The valve body's mating surface is a straight surface along the axial direction, featuring a single-stage stepped stop sealing structure. Precision grinding ensures a flatness of ≤0.05mm, and the overall axial gap after mating is ≤0.03mm. The absence of radial steps and undercut structures ensures smooth radial release of the valve body after curing, without any jamming resistance. The inner side of the valve body is a smooth, reinforced curved surface with three axial reinforcing ribs, significantly improving the valve body's bending stiffness and preventing deformation due to fiber tension during winding.

[0101] The outer circumference of both ends of the petal body is provided with annular positioning stops and clamping flanges. The diameter of the stop at the large end is φ360mm, and the diameter of the stop at the small end is φ200mm. The width of the stop is 50mm, and the coaxiality of the stop is ≤0.1mm. Six demolding butterfly holes are evenly arranged on the flange for positioning and clamping with an external three-jaw chuck to ensure rotational accuracy.

[0102] The core mold in this embodiment weighs approximately 1.2 tons, which is only 40% of the weight of a traditional three-lobed core mold with an internal tensioning mechanism. The manufacturing cost of a single core mold is approximately 45% of that of a traditional core mold. Furthermore, it has no easily damaged moving parts, and daily maintenance only requires surface cleaning. The annual maintenance cost is less than 30% of that of a traditional mold.

[0103] 3. Molding process

[0104] The low-deflection composite material pole winding molding process in this embodiment is as follows: Figure 3 As shown, the specific steps are as follows:

[0105] Step S1: Mold pretreatment and assembly

[0106] First, use a lint-free cloth soaked in anhydrous ethanol to wipe the cavity surfaces and mating surfaces of the three fan-shaped petals clean, thoroughly removing oil, residual resin, and dust impurities. After the ethanol has completely evaporated, evenly spray two coats of semi-permanent fluorinated mold release agent, with a 15-minute interval between each coat. The spray thickness should be uniform, without any missed areas or drips. After spraying, allow to dry at room temperature for 30 minutes before use. Place the three dried petals on a horizontal assembly fixture and align them circumferentially. Use the stepped stop for precise alignment, and gently tap with a copper hammer to adjust the axial position of each petal, ensuring that the end faces are flush and the misalignment is ≤0.5mm. After assembly, use a feeler gauge to check the gaps on the mating surfaces along the entire axis, ensuring that the maximum gap is ≤0.03mm, forming a complete conical core mold.

[0107] Step S2: Pre-installation of reinforcing ribs

[0108] Slowly insert the pre-cured, one-piece three-pronged reinforcing rib axially from the large end of the mandrel, keeping the reinforcing rib coaxial with the mandrel during the process, so that the three rib wings are accurately embedded in their corresponding rib slots; fill the gaps between the rib wings and the slots with epoxy resin-based filler to eliminate interface gaps; after inserting it into place, adjust the axial position of the reinforcing rib so that both ends extend 50mm beyond the end face of the mandrel, and use high-temperature resistant polyimide tape to temporarily fix the reinforcing rib to the mandrel at both ends, fixing it at 3 points at each end to prevent axial movement or circumferential displacement during subsequent winding.

[0109] In this embodiment, the axial slip component under the maximum winding clamping force is approximately 2.8 kN, the end clamping friction force is approximately 6 kN, and the safety factor is 2.14, which meets the requirements for stable winding.

[0110] Step S4: Inner liner winding

[0111] Start the winding machine and set the mandrel speed to 8 r / min. Prepare the inner liner using a circumferential winding method. Pre-prepare the epoxy resin solution with the following mass ratio: bisphenol A type epoxy resin E-51: methyltetrahydrophthalic anhydride curing agent: accelerator DMP-30 = 100:80:0.5. After thorough mixing, perform vacuum degassing treatment and adjust the viscosity of the solution to 300 mPa·s at 25°C. Impregnate the glass fiber surface mat with the resin solution and then wind it. Control the winding tension to 5 N / bundle to ensure the resin fully wets the fiber and adheres tightly to the cavity surface. Stop winding the inner liner when it reaches a thickness of 1 mm and allow it to gel at room temperature for 45 minutes to reach a B-stage semi-cured state, preventing the inner liner from being squeezed and displaced during subsequent structural layer winding.

[0112] Step S5: Winding of structural reinforcement layer

[0113] After the inner liner layer is gelled, the structural reinforcement layer winding begins. 2400tex alkali-free glass fiber roving is used, with gradient tension control: the inner 3 layers have a tension of 15N / bundle, the middle 4 layers have a tension of 20N / bundle, and the outer 3 layers have a tension of 25N / bundle. The winding machine operates automatically according to the preset layup program, winding layers at various angles sequentially. During winding, the yarn feed speed is adjusted in real time according to the mandrel diameter to ensure that the winding angle deviation of each layup is ≤±1°. By controlling the number of winding layers at different axial positions, a gradient wall thickness of 12mm at the large end and 6mm at the small end is achieved. During winding, the circumferential tension of the fiber creates a uniform clamping effect on the mandrel, with the clamping force gradually increasing with the number of layups, forming a stable constraint system together with the clamping force of the chucks at both ends. When the mandrel speed increases to 20r / min, the three independent petals remain tightly fitted, without any relative displacement or radial opening, requiring no internal support mechanism.

[0114] Step S6: Curing and Molding

[0115] After the structural layer is wound, a layer of polypropylene release fabric is wound onto the outermost layer of the rod to improve the smoothness of the cured outer surface. Then, the entire mandrel with the product is removed from the winding machine and smoothly fed into a hot air circulating curing oven. The following curing process curve is followed for programmed temperature increase and curing: First stage: The temperature is increased from room temperature to 80℃ at a rate of 1.5℃ / min and held for 2 hours to allow the resin to initially cross-link and solidify, preventing excessive resin sagging at high temperatures; Second stage: The temperature is increased to 120℃ at a rate of 1℃ / min and held for 4 hours to allow the resin to fully cross-link and cure, achieving the highest mechanical properties; Third stage: After the holding period, the heating system is turned off, and the furnace is allowed to cool naturally to below 40℃ before the mandrel is removed from the oven. During curing, the mandrel is placed on a rotating support inside the oven and rotated at a low speed of 1 r / min to prevent resin from sagging downwards due to gravity, ensuring uniform circumferential wall thickness of the rod.

[0116] Step S7: Demolding

[0117] After the core mold, having cured, cools to room temperature, it is re-clamped into a dedicated demolding station. Simultaneously, the three-jaw chucks at both ends are released, completely releasing the clamping force. At this point, due to the approximately 2% volume shrinkage rate during epoxy resin curing, the inner wall of the pole exerts a radial clamping force on the core mold. Under the influence of the component force from the conical inclined surface, the three fan-shaped segments automatically release radially inward, naturally separating from the inner wall of the pole, forming a uniform gap of approximately 1.5mm. Subsequently, a dedicated traction fixture is used to connect to the demolding butterfly hole of the end flange. One segment is slowly extracted from the larger end, and then the pole is rotated to extract the other two segments in sequence. Because the segments are completely separated from the inner wall, the extraction process involves minimal resistance, and the total demolding time for a single pole is approximately 20 minutes. The demolded inner wall of the pole is smooth and flat, with only extremely fine joining lines, no obvious mold-closing steps or mechanical traces, and the inner wall molding quality is far superior to products formed using traditional core molds.

[0118] Step S8: Post-processing and finished product inspection

[0119] After demolding, the poles are hoisted to the post-processing station, where excess burrs and excess material at both ends are removed using a diamond cutter to ensure flat end faces and length deviations within ±10mm. Then, the pole surface is lightly sanded to remove burrs and drip marks. Finally, a full inspection is conducted according to GB / T23147-2008 "Composite Material Pole Towers for Overhead Transmission Lines," including dimensional deviations, appearance quality, Barcol hardness, bending resistance, and corrosion resistance. Once the inspection is passed, the pole is considered a finished low-deflection composite material pole.

[0120] In this embodiment, the production cycle for a single pole is approximately 12 hours, with a yield rate of 98.5%. Compared to the traditional two-part mold process, the production efficiency is increased by more than 4 times, the yield rate is increased by 18 percentage points, and the overall production cost is reduced by 25%, resulting in significant economic benefits.

[0121] Example 2

[0122] This embodiment is a low-deflection composite material pole for an 18-meter-long communication base station, which uses an unsaturated polyester resin room temperature curing process to verify the compatibility and applicability of the technical solution of the present invention to different resin systems and products of different specifications.

[0123] In this embodiment, the pole has a diameter of φ430mm at the large end and φ190mm at the small end, with a taper of 1:60 and a total length of 18m. The pole structure also consists of an inner lining layer, a structural reinforcement layer, and an outer protective layer, with an integrated three-pronged reinforcing rib. The structural reinforcement layer is made of medium-alkali glass fiber winding, with a wall thickness of 16mm at the large end and 7mm at the small end. In the layup design, the longitudinal fiber ratio is increased to 55%, further improving the bending stiffness of the long pole and reducing the problem of increased deflection caused by the slenderness ratio.

[0124] The three-lobed mandrel structure used is completely consistent with the principle of Example 1, with only the size adjusted accordingly. Due to the increase in mandrel length, the lobes are made of cast steel to improve the overall rigidity of the large-size mandrel and prevent winding deformation. The end clamping force is increased by 30%, with the large end clamping force being 14kN and the small end being 10kN, which meets the stable winding requirements of the long mandrel.

[0125] The main difference between the molding process in this embodiment and that in Embodiment 1 lies in the resin system and curing method: Phthalic unsaturated polyester resin is used as the matrix, combined with methyl ethyl ketone peroxide curing agent and cobalt naphthenate accelerator. The gel time of the adhesive at room temperature is controlled at 40-60 minutes. After the structural layer is wound, it does not need to be placed in a curing oven; it can be cured at room temperature (25°C) for 24 hours to achieve the required demolding strength. Further performance can be improved by post-treatment at 80°C as needed. The demolding process also employs a method of natural release after unclamping and extraction piece by piece, resulting in smooth demolding and good inner wall quality.

[0126] Tests showed that the pole in this embodiment had a top deflection of 112 mm and a deflection-to-span ratio of 1 / 160.7 under a rated bending moment of 20 kN·m, which also met the low deflection design requirements. It can be used in outdoor high-load scenarios for communication base stations, and the room temperature curing process further reduces the investment in production equipment and energy consumption costs.

[0127] Example 3

[0128] This embodiment is a 15-meter carbon-glass hybrid composite material pole designed for high wind pressure areas along the coast. It adopts a hybrid reinforcement system of vinyl ester resin and carbon fiber-glass fiber to further improve specific strength and corrosion resistance.

[0129] In this embodiment, the pole has a diameter of φ480mm at the large end and φ210mm at the small end, with a taper of 1:50 and a total length of 15m. The structural reinforcement layer is made of a hybrid of T700 carbon fiber and E glass fiber, with carbon fiber accounting for 30% of the volume, mainly distributed in the 0° longitudinal layup to improve bending stiffness. The wall thickness at the large end is 14mm, and the wall thickness at the small end is 7mm, increasing the proportion of the 0° longitudinal layup to 58%. The reinforcing ribs are made of carbon-glass hybrid prepreg, with a rib flange height of 35mm at the large end, and the moment of inertia of the section is increased by 28% compared to pure glass fiber reinforcing ribs.

[0130] In the molding process, the winding tension is set differently according to the fiber type: 18N for a single bundle of carbon fiber and 22N for a single bundle of glass fiber. Curing employs a stepped temperature increase process: 60℃ for 2 hours, 90℃ for 2 hours, and 120℃ for 3 hours to ensure full resin cross-linking. Testing showed that the pole in this embodiment exhibits a top deflection of 89mm under a rated bending moment of 30kN·m, with a deflection-to-span ratio of 1 / 168.5, meeting the requirements for power transmission lines in areas experiencing Category 14 typhoons.

[0131] Comparison and performance verification

[0132] To further verify the technical advantages of the present invention, two sets of comparative examples were set up for comparative testing: Comparative Example 1: A 12-meter composite material pole of the same specification was formed using a traditional three-lobed core mold with an internal hydraulic tensioning mechanism, without built-in reinforcing ribs, and with a uniform wall thickness of 9mm. Comparative Example 2: A 12-meter composite material pole was formed using an integral metal core mold, and after forming, a three-pronged reinforcing rib was attached using epoxy adhesive, with the gradient wall thickness consistent with Example 1.

[0133] The core performance data is as follows, based on the unified testing conducted according to the GB / T23147-2008 standard:

[0134] sheet

[0135] Deflection-to-span ratio under rated bending moment 1 / 166.7 1 / 92 1 / 118 Ultimate flexural capacity (kN·m) 36 24.5 29.2 Interfacial shear strength (MPa) Seamless interface - 8.7 Demolding time (min) 20 145 35 (Integral mold ejection) Finished product yield (%) 98.5 79 86 Inner wall roughness Ra (μm) 2.1 6.5 1.8

[0136] Test results show that the present invention has significant advantages in deflection control, overall mechanical properties, demolding efficiency and yield. Although Comparative Example 2 has better inner wall quality, the reinforcing rib interface strength is low, and it is easy to debond under long-term alternating load. In addition, the overall mold has high demolding resistance and is easy to damage the product. The present invention achieves simultaneous improvement of multiple properties through synergistic innovation of structure, mold and process.

[0137] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-deflection composite material pole, characterized in that: The pole is an integral conical rotating structure with a larger diameter at the larger end than at the smaller end and a taper of 1:75 to 1:

40. The pole body consists of an inner lining layer, a structural reinforcement layer, and an outer protective layer from the inside out. The pole body is equipped with an integral three-pronged through-branch reinforcing rib, which runs through the entire length of the pole body along the axial direction. The reinforcing rib and the pole body wall are integrally cured and formed with a resin matrix, without splicing interfaces or secondary bonding interfaces. Under the rated bending moment load, the ratio of the top deflection to the pole length shall not exceed 7 / 100.

2. The low-deflection composite material pole according to claim 1, characterized in that: The cross-section of the integrated three-pronged reinforcing rib is Y-shaped, with the three rib wings evenly distributed circumferentially, and the included angle between adjacent rib wings is 120°. The cross-sectional area of ​​the reinforcing rib decreases linearly from the large end to the small end along the axial direction. The reinforcing ribs are made of fiber-reinforced composite materials using the same resin system as the reinforcing layer of the rod structure, and the ends of the rib wings are completely fused with the inner wall of the rod.

3. The low-deflection composite material pole according to claim 1, characterized in that: The structural reinforcement layer is formed by continuously reinforcing fibers impregnated with resin and wound at a designed angle. It adopts a gradient wall thickness design, with a wall thickness of 8~25mm at the large end and 4~12mm at the small end, and the wall thickness is linearly transitioned along the axial direction. The structural reinforcement layer comprises 0° longitudinal ply, ±45° diagonal ply and 90° circumferential ply, wherein the 0° longitudinal ply accounts for 40% to 60% of the total number of ply, the ±45° diagonal ply accounts for 25% to 40% of the total number of ply, and the 90° circumferential ply accounts for 10% to 20% of the total number of ply.

4. A three-lobed molding core mold for molding the low-deflection composite material pole according to any one of claims 1-3, characterized in that, The core mold is composed of three independent sector-shaped lobes that are evenly divided along the axial direction. The central angle of each sector-shaped lobe is 120°. The three lobes are assembled to form a complete 360° conical cylinder. There is no central connecting shaft, no tie rod, no internal tensioning mechanism, and no internal connecting skeleton between the three valves. They are formed by the close fitting of the splicing surfaces to form a complete conical rotary cavity. The two ends of the core mold are positioned, clamped, and rotated only through external clamping mechanisms. The cavity surface of the flap body is provided with three shallow rib grooves that run through the axial direction. The three rib grooves are evenly distributed 120° around the circumference and their positions correspond one-to-one with the three rib wings of the triangular reinforcing rib. They are used for pre-installing and positioning the axial reinforcing rib.

5. The three-lobed molding core mold according to claim 4, characterized in that, The splicing surface of the valve body is a straight surface along the axial direction or a small-angle inclined surface of 1° to 3°. The splicing surface is provided with a stepped stop sealing structure, and there are no radial steps or undercut structures after splicing. The splicing surfaces are precision machined, with a flatness of ≤0.05mm and a gap of ≤0.03mm after splicing.

6. The three-lobed molding core mold according to claim 4, characterized in that, The depth of the rib groove is 1 / 3 to 1 / 2 of the thickness of the reinforcing rib, and the width matches the width of the reinforcing rib flange, ensuring that the reinforcing rib is partially embedded in the groove and positioned after installation, and partially protrudes from the cavity surface. The outer cavity surface of the valve body is a high-precision polished surface with a surface roughness Ra≤0.8μm; the valve body is a hollow thin-walled reinforced structure with axial reinforcing ribs on the inner side.

7. The three-lobed molding core mold according to claim 4, characterized in that, The outer circumference of both ends of the petal body is provided with annular positioning stops and clamping flanges. The flanges are provided with demolding pull-out fixing butterfly holes, which are used to cooperate with external clamping chucks to achieve circumferential positioning and synchronous clamping, and are adapted to demolding tooling connections. The coaxiality of the positioning stop is ≤0.1mm.

8. A winding molding process for a low-deflection composite material pole, characterized in that, The implementation based on the three-lobed molding core mold according to any one of claims 4-7 includes the following steps: Step 1: Assemble the three sector-shaped petals to form a complete conical core mold. Step 2: Insert the prefabricated one-piece three-pronged reinforcing rib into the core mold along the axial direction, so that the three rib wings are respectively embedded in the corresponding rib slots on the cavity surface, and temporarily fix them. Step 3: Mount the assembled core mold onto the winding machine and clamp it simultaneously using the external clamping chucks at both ends; Step 4: Wrap the inner liner layer onto the core mold surface to the designed thickness, and proceed to the next step after gelation; Step 5: Perform structural reinforcement layer winding. Use a multi-axis linkage winding machine to lay up the layers at each angle in the designed layup sequence. During the winding process, a gradient tension control strategy is adopted. The inner layer winding tension is 10~15N / bundle, and the outer layer tension is gradually increased to 20~30N / bundle. Step Six: After the structural layer is wound, it is cured and molded. Step 7: After curing, release the clamping force of the chucks at both ends. The three fan-shaped petals will naturally loosen radially inward. Then, pull the three petals out axially from both ends of the pole to complete the demolding.

9. The winding molding process for low-deflection composite material poles according to claim 8, characterized in that, In step five, during the winding of the structural reinforcement layer, the fiber tension applies a uniform clamping force to the mandrel in the circumferential direction. This clamping force, together with the clamping force of the chucks at both ends, forms a spatial constraint system, ensuring that the three independent petals remain tightly fitted during rotation. In step three, the clamping force at the large end is set to 5~15kN, and the clamping force at the small end is set to 3~10kN, satisfying the mechanical conditions for stable winding. ,in The static friction force generated by the clamping force. The axial slip component is generated by the circumferential clamping force. For safety factors, the value is 1.5 to 2.

0.

10. The winding molding process for low-deflection composite material poles according to claim 8, characterized in that, In step six, the curing process adopts a stepped temperature rise curve: the temperature is increased to 80°C at a rate of 1~2°C / min and held for 2 hours; then the temperature is increased to 120°C at a rate of 1°C / min and held for 4 hours. After the heat preservation period, the furnace is cooled to below 40°C before being removed from the furnace. During the curing process, the core mold rotates at a low speed of 0.5~2 r / min; In step seven, the curing shrinkage creates a 1-2mm demolding gap between the inner wall of the pole and the core mold, and the demolding time for a single pole is 15-30 minutes.

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