A fastener for offshore photovoltaic masts and offshore photovoltaic mast connection system

Abstract

The utility model discloses a fastener and offshore photovoltaic pull rod connecting system for offshore photovoltaic pull rod, fastener includes: the hoop, set up the first nut of hoop one end, set up the second nut of hoop other end, first nut and second nut inner wall all are equipped with with offshore photovoltaic pull rod cooperation's inner sleeve body, set up the notch on inner sleeve body, a kind of offshore photovoltaic pull rod connecting system, including: offshore photovoltaic pull rod and secondary purlin, secondary purlin is fixed through fastener, and structure glue is injected in the glue injection hole in the fastener. The utility model solves the corrosion and reliability problem that present offshore photovoltaic support pull rod faces, and pull rod surface has no anticorrosive coating, and fastener can be directly bonded with the pull rod body, to ensure the effectiveness and reliability of connecting node.

Description

Technical Field

[0001] This utility model relates to the field of structural engineering technology, specifically to a fastener for marine photovoltaic rods and a marine photovoltaic rod connection system. Background Technology

[0002] Currently, the tie rods and connectors of offshore photovoltaic (PV) systems are generally made of steel rods connected by steel nuts. These metal structures are exposed to the high humidity and high salinity of the marine environment for extended periods, causing a liquid film to form on their surfaces. Chloride ions from the air dissolve in this film, leading to metal corrosion. Even with anti-corrosion coatings applied to the steel tie rods and nuts, the coating is susceptible to friction and damage during installation and transportation, resulting in peeling and affecting the structure's lifespan. Furthermore, under wind loads, the nuts at both ends of the steel tie rods are prone to loosening and falling off, and secondary purlins are also subject to lateral displacement due to wind loads, impacting structural stability and safety.

[0003] Existing technical solutions for offshore photovoltaic support rods and connection methods, such as Figure 1 As shown, it includes a tie rod 1, a secondary purlin 2, a washer 3, and a matching nut 4. The surface of the tie rod 1 is coated with anti-corrosion paint, and both ends of the tie rod are tapped. The secondary purlin 2 is connected and fixed to the tie rod 1 through the matching washer 3 and nut 4.

[0004] Existing tie rod solutions typically combine steel with an anti-corrosion coating. However, steel is not corrosion-resistant and is prone to rusting in marine environments, leading to reduced material strength and impacting structural safety and stability. Secondly, the tie rods are threaded at both ends and connected to secondary purlins via nuts. On the one hand, the nuts can easily damage the anti-corrosion coating at the threads during installation; on the other hand, marine structures are subject to reciprocating loads from wind suction and pressure, which can cause the nuts to loosen and fall off, affecting structural safety and stability and increasing the workload of structural maintenance and replacement during operation and maintenance. Furthermore, applying an anti-corrosion coating to the surface of round rods and screws is difficult and prone to initial defects such as coating wrinkles and localized exposure, further increasing the workload of anti-corrosion repair during construction and operation and maintenance. Utility Model Content

[0005] To address the corrosion and reliability issues faced by existing offshore photovoltaic (PV) support rods, this invention proposes a fastener and connection system for offshore PV support rods.

[0006] This utility model relates to fiber composite material fasteners. These fasteners are made from natural, corrosion-resistant fibers and weather-resistant resins, eliminating the need for additional anti-corrosion coatings on the material surface and preventing corrosion. The fasteners feature a split design, allowing for the installation of a set at one end of the tie rod and on both sides of the secondary purlin, effectively locking the secondary purlins and preventing lateral displacement. Furthermore, the fasteners are connected to the tie rod via pre-tightening and pressure injection, eliminating the need for tapping at the tie rod end, simplifying manufacturing. The adhesive bonding method is unaffected by wind vibration loads, resulting in greater stability and ensuring long-term structural stability. Since the anti-corrosion coating on steel tie rods is prone to peeling, and adhesive-bonded fasteners are susceptible to detachment along with the coating, this utility model proposes a corrosion-resistant and aging-resistant fiber composite material tie rod. This tie rod has no anti-corrosion coating, allowing the fasteners to be directly bonded to the tie rod body, ensuring the effectiveness and reliability of the connection.

[0007] A fastener for offshore photovoltaic masts includes: Hoop; The first nut is provided at one end of the clamp; The second nut is provided at the other end of the clamp; The inner walls of both the first nut and the second nut are provided with inner sleeves that cooperate with the marine photovoltaic rod; A notch is provided on the inner sleeve.

[0008] The clamp has threads at both ends.

[0009] The inner wall of the clamp is provided with a direct current channel, and the direction of the direct current channel is consistent with the axial direction of the clamp.

[0010] The inner wall of the clamp is provided with a threaded flow channel, which is connected to the direct flow channel.

[0011] The inner walls at both ends of the clamp are provided with neck grooves, which are connected to the threaded flow channels.

[0012] The clamp is provided with an injection hole and an exhaust hole, both of which are connected to the DC channel.

[0013] The outer wall of the clamp is provided with a hexagonal protrusion.

[0014] The clamp is divided into two halves, and both the first and second halves are provided with locking keyways and chamfered keyways that cooperate with each other.

[0015] The inner wall of the clamp is provided with an inner cavity reinforcing bar.

[0016] A marine photovoltaic (PV) mast connection system includes: a marine PV mast and secondary purlins installed on the marine PV mast. The secondary purlins are fixed by fasteners installed on the marine PV mast. Structural adhesive is injected into the fasteners through injection holes. The fasteners are the fasteners used for marine PV masts.

[0017] Furthermore, a fiber composite fastener and its connection method include: Fiber composite material clamps; Fiber composite nut for use with clamps; Fiber composite material marine photovoltaic tie rod; This invention employs a novel fiber composite material fastener and pressure injection method to connect the marine photovoltaic strut and secondary purlin. Firstly, the new fiber composite material fastener is made of natural corrosion-resistant fibers and weather-resistant resin, eliminating the need for an additional anti-corrosion coating and preventing corrosion. Secondly, the fastener features a split-type design; one set includes one clamp and two matching nuts. One set of fasteners can be installed at each end of the connection between the strut and secondary purlin, thereby locking the secondary purlin and preventing lateral displacement. Furthermore, the fastener is connected to the strut body via pre-tightening and pressure injection, eliminating the need for tapping at the strut end, simplifying manufacturing. The fastener includes injection holes, vent holes, and injection channels, ensuring more uniform adhesive distribution. The adhesive bonding method is unaffected by wind vibration loads, resulting in a more stable and reliable structure and ensuring long-term stable operation. This fastener, used in conjunction with fiber composite tie rods, solves the problem of difficult tapping at the ends of fiber composite tie rods, retains the full strength of the fiber composite tie rods, has a simple installation process, reliable installation effect, improved installation efficiency, and extends the service life of the structure.

[0018] The aforementioned fiber composite fasteners and their connection methods are used to connect and lock the marine photovoltaic tie rods and secondary purlins, preventing lateral displacement of the secondary purlins and ensuring structural stability.

[0019] The composite material fasteners (i.e., fastener clamps, first nuts, second nuts, inner sleeves, etc.) are made of chopped glass fiber or chopped basalt fiber, epoxy resin, and UV stabilizer. The fiber weight percentage is 55%~65%, the epoxy resin weight percentage is 30%~43.5%, and the UV stabilizer content is about 1.5%. The composite material is a natural corrosion-resistant material. After a salt spray corrosion test of 3000 hours, the material strength retention rate is 85%, the service life is not less than 30 years, no anti-corrosion coating is required, and maintenance is required during the operation and maintenance period.

[0020] The composite material fastener consists of one set of clamps and two matching nuts, and is a split structure that is easy to assemble and disassemble.

[0021] The aforementioned fiber composite fastener consists of one set of clamps, comprising two semi-circular clamps. One semi-clamp includes upper and lower threaded sections, an injection hole, a locking keyway, a chamfered keyway, an inner cavity injection pipe, a central groove, an inner cavity clamping rib, a neck groove, and a hexagonal boss. The other semi-clamp includes upper and lower threaded sections, a vent hole, a locking keyway, a chamfered keyway, an inner cavity injection pipe, a central groove, an inner cavity clamping rib, a neck groove, and a hexagonal boss.

[0022] The nut that matches the fiber composite fastener is a hexagonal nut with internal threads. One end of the nut has a round hole, and an inner sleeve extends from the round hole to pass through the round rod-shaped tie rod.

[0023] The fiber composite fastener is connected to the tie rod via a "pre-tightening and pressure injection" method. After the fastener is tightened with a nut, a certain pre-tightening force is generated, which initially fixes the tie rod and the fiber composite fastener. Then, a certain amount of structural adhesive is injected through the injection hole of the fastener clamp. Air inside the clamp is expelled through the vent hole. The adhesive injection pipeline inside the clamp cavity facilitates the uniform diffusion of the structural adhesive until the clamp cavity is filled. A small amount of structural adhesive overflows from the vent hole. After the structural adhesive cures, it further strengthens the connection strength between the fastener and the tie rod, ensuring the performance of the structure at the connection node.

[0024] The fiber composite material fasteners are installed on both the inner and outer sides of the connection node between the photovoltaic tie rod and the secondary purlin. After fixing, they can lock the secondary purlin and prevent it from lateral displacement.

[0025] The fiber composite fasteners, when used in conjunction with fiber reinforced composite smooth round tie rods, can achieve optimal fixing performance and avoid tapping the ends of the fiber reinforced composite tie rods.

[0026] Compared with the prior art, the present invention has the following advantages: 1. The fiber composite fasteners used are made of natural corrosion-resistant fibers and weather-resistant resin materials. Compared with steel nuts, they are lightweight, high-strength, and corrosion-resistant, avoiding the initial defects and later maintenance problems that may be caused by anti-corrosion coatings, and improving the service life of the structure.

[0027] Second, the fiber composite fasteners are connected using a "bolt pre-tightening + pressure injection" method, eliminating the need for tapping at the ends of the tie rod. This preserves the full strength of the tie rod body and avoids structural damage or coating peeling at the threads. The processing technology is simple and low-cost. Furthermore, compared to traditional threaded connections, adhesive bonding offers higher connection strength and wind vibration resistance, better adapting to the complex and variable marine environment and ensuring the long-term stability and safety of the photovoltaic support structure.

[0028] Third, the fastener adopts a split structure design, which facilitates assembly and disassembly, greatly improves construction efficiency and maintenance convenience, and reduces maintenance costs.

[0029] Fourth, the fastener can be installed at one end of the tie rod and on both sides of the secondary purlin to lock the secondary purlin, prevent it from lateral displacement, and improve the overall rigidity and stability of the photovoltaic support structure.

[0030] Fifth, in addition, the design of this fastener also takes into account the uniform distribution of structural adhesive. By setting up injection holes, vent holes and injection channels, it is ensured that the structural adhesive can evenly and fully fill the inner cavity of the clamp, forming a firm bond with the tie rod, further enhancing the reliability and durability of the connection.

[0031] VI. This fastener performs best when used with fiber-reinforced composite tie rods. Firstly, both are based on epoxy resin, and when combined with epoxy structural adhesive, the interfacial bonding performance of the same material is optimal, resulting in higher connection strength. Secondly, the tie rod has no anti-corrosion coating, allowing the fastener to be directly bonded to the rod body, fully utilizing the performance of the structural adhesive.

[0032] VII. In addition, fiber composite materials use natural basalt as raw material, and the production process is green, environmentally friendly and pollution-free. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of steel tie rods and their connection methods in the prior art; Figure 2 This is a schematic diagram of the composite material fastener of this utility model; Figure 3 This is a schematic diagram of the fiber composite fastener clamp of this utility model; Figure 4 This is a schematic diagram of the fiber composite fastener nut of this utility model. Detailed Implementation

[0034] The embodiments of the novel fiber composite fastener and its connection method of this utility model are described in detail below with reference to the accompanying drawings.

[0035] like Figure 2 As shown, the fiber composite fastener and its connection method include the following components: nut 1-1 of composite fastener, clamp 1-2 of composite fastener, secondary purlin 1-3, and tie rod 1-4.

[0036] like Figure 3As shown, the composite material fastener consists of two semi-circular clamps 1-2. The clamp 1-2 includes the following components: upper threaded section 2-1, locking keyway 2-2, chamfered keyway 2-3, hexagonal boss 2-4, center groove 2-5, inner cavity clamping rib 2-6, inner cavity glue injection pipe 2-7 (including straight channel and threaded flow channel), glue injection hole 2-8, neck glue groove 2-9, lower threaded section 2-10, and vent hole 2-11.

[0037] like Figure 3 As shown, threaded sections 2-1 and 2-10 are used to connect with nut 1-1; the locking keyway 2-2 is designed with a concave-convex shape, which allows the two semi-circular clamps to be locked together to prevent them from falling off; the chamfered keyway 2-3 is a sloped design, mainly used as a transition section at the joint of the locking keyways of the two clamps, making them fit more tightly and preventing structural adhesive from overflowing; the hexagonal boss 2-4 serves as a fixing force point when screwing nut 1-1 into clamp 1-2, and can be used with a wrench, which can avoid damaging the clamp body structure and facilitates installation; a central groove 2-5 is designed on one side of the two semi-circular clamps, offset from the chamfered keyway 2-3, and a corresponding protruding glue injection pipe 2-7 is designed on the other side. When the two semi-circular clamps are closed, the protruding glue injection pipe of the other half of the clamp can be embedded in the central groove 2-5, further preventing structural adhesive from overflowing from the side. The overflow design ensures better sealing. The inner cavity clamping rib 2-6 has a protruding design; when the two semi-circular clamps are closed, their diameter is the same as that of the tie rod 1-4. This strengthens the clamping structure and secures the tie rod, preventing it from slipping. The inner cavity injection pipe 2-7 consists of a central flow channel and an annular flow channel running through the top and bottom. During pressure injection, structural adhesive is injected through the injection hole 2-8. The inner cavity injection pipe 2-7 allows the structural adhesive to quickly and evenly fill the inner cavity. Air in the inner cavity is discharged through the vent hole 2-11. When the structural adhesive fills the vent hole 2-11, the injection is stopped, ensuring that the clamp 1-2 and the tie rod 1-4 are fully bonded, and there are no gaps in the inner cavity. The neck adhesive groove 2-9 allows the structural adhesive to flow into the upper threaded section 2-1 and the lower threaded section 2-10, ensuring that the structural adhesive fills the entire inner cavity of the clamp and fully bonds with the tie rod.

[0038] like Figure 4 As shown, the composite material fastener nut 1-1 includes the following components: thread 3-1, round hole 3-2, inner sleeve 3-3, and V-shaped notch 3-4. The diameter of the round hole 3-2 is 0.15 mm larger than the diameter of the pull rod 1-4, ensuring that the pull rod 1-4 can be inserted into the nut 1-1 of the new fiber composite material fastener; the inner sleeve 3-3 connects to the round hole 3-2 and extends downwards, with the diameter at the closing point being 0.2 mm smaller than that of the pull rod 1-4, to tighten the pull rod 1-4; the function of the V-shaped notch 3-4 is to appropriately expand the inner sleeve when the pull rod 1-4 is inserted into the inner sleeve 3-3, ensuring that the inner sleeve can undergo a certain amount of deformation.

[0039] like Figure 2 As shown in Figures 3 and 4, the two nuts 1-1 of the fiber composite fastener and one set of clamps 1-2 are pre-assembled into a whole. During this process, the nuts 1-1 are only screwed into the upper thread section 2-1 and the lower thread section 2-10 by half a screw. Then, the two pre-assembled sets of new fiber composite fasteners are installed into the tie rod 1-4, so that it is located between the two secondary purlins and close to the secondary purlin 1-3. The end of the tie rod 1-4 is passed through the web hole of the secondary purlin 1-3, so that... The secondary purlin 1-3 is initially connected to the tie rod 1-4; then, the other two sets of pre-assembled new fiber composite material fasteners are installed at the end of the tie rod 1-4, close to the position of the secondary purlin 1-3; finally, the clamp 1-2 and nut 1-1 are tightened in sequence to initially fix the tie rod 1-3 and the secondary purlin 1-4; a certain amount of structural adhesive is injected through the glue injection hole 2-7 using an electric glue gun or a pneumatic glue gun for secondary reinforcement, and the strength of the connection node is mainly provided by the structural adhesive.

[0040] Composite material fasteners (i.e., fastener clamps, first nuts, second nuts, inner sleeves, etc.) are made of chopped glass fiber or chopped basalt fiber with epoxy resin and UV stabilizer. The fiber accounts for 61% of the weight, the epoxy resin accounts for 37.5% of the weight, and the UV stabilizer content is about 1.5%. The composite material is a natural corrosion-resistant material. After a salt spray corrosion test of 3000 hours, the material strength retention rate is 85%, the service life is not less than 30 years, no anti-corrosion coating is required, and maintenance is required during the operation and maintenance period.

[0041] The tie rods 1-4 used in this invention are made of fiber-reinforced composite material, which is produced by pultrusion molding of glass fiber or basalt fiber, epoxy resin, and UV stabilizer. The glass fiber content is 78%, the polyurethane content is 20.5%, and the UV stabilizer content is about 1.5%. The material has a tensile strength of up to 1200 MPa and a compressive strength of up to 1000 MPa. After 3000 hours of UV and salt spray aging tests, the material retains more than 85% of its strength, has a service life of no less than 30 years, requires no anti-corrosion coating, and is maintenance-free during the operation and maintenance period.

[0042] The composite material fastener has a total height of 66mm and consists of one clamp and two matching nuts. It adopts a split design for easy assembly and disassembly.

[0043] A single set of fiber composite fastener clamps has a height of 56mm and consists of two semi-circular clamps. The clamp includes upper and lower threaded sections (9mm high, 2 rounds of arc-shaped coarse threads), an injection hole (5.5mm in diameter), a locking keyway (2mm wide), a chamfered keyway, an inner cavity injection pipeline (inner annular groove-shaped flow channel diameter 14.4mm~15mm, inner straight channel width 3mm), a center groove (6.25mm in length, 2mm in depth), an inner cavity clamping rib (12mm in diameter), a neck glue groove, a vent hole (5.5mm in diameter), and a hexagonal boss.

[0044] The nut for the fiber composite fastener is 15mm high and is a hexagonal nut with an internal thread 3-1. One end of the nut has a round hole 3-2 (outer diameter of the round hole is 3mm). An inner sleeve 3-3 (length 9.3mm, diameter at the tapered end 12mm, thickness 0.7mm) extends from the round hole inward. The end of the inner sleeve has four V-shaped notches 3-4 (depth 3.4mm, opening width 2mm, notch width 0.8mm). The inner sleeve 3-3 is used to pass through and clamp the round tie rod.

[0045] The fiber composite fastener connection method is "bolt pre-tightening and pressure injection". After the fastener is tightened by the nut 1-1 to the clamp 1-2, a pre-tightening force of about 3KN is generated, which initially fixes the tie rod 1-4. Then, structural adhesive (with a strength of 20MPa) is injected through the injection hole 2-8 of the clamp 1-2. The air inside the clamp will be discharged through the vent hole 2-11. The injection pipe 2-7 in the inner cavity of the clamp and the adhesive groove 2-9 in the neck are channels for the uniform diffusion of structural adhesive inside. After the structural adhesive cures, it will further strengthen the connection strength between the fastener and the tie rod (the maximum tensile strength can reach 41.4KN, which is higher than the maximum tensile strength of the tie rod body of 13.5KN), ensuring the safety of the structure at the connection node.

[0046] Fiber composite fasteners are installed on both the inner and outer sides of the connection node between the photovoltaic tie rod and the secondary purlin. After fixing, they can lock the secondary purlin and prevent it from shifting laterally.

[0047] Tie rods 1-4 are fiber-reinforced composite material tie rods (12mm in diameter), made of glass fiber and epoxy resin, with a fiber content of 78% and a resin content of 32%. They are combined with fiber composite material fasteners, which can avoid tapping the ends of the fiber-reinforced composite material tie rods and retain 100% of the tie rod strength (tensile strength 1200MPa).

Claims

1. A fastener for marine photovoltaic tie rods, characterized in that, include: Hoop; The first nut is provided at one end of the clamp; A second nut is provided at the other end of the clamp; The inner walls of both the first nut and the second nut are provided with inner sleeves that cooperate with the marine photovoltaic rod; A notch is provided on the inner sleeve.

2. The fastener for marine photovoltaic rods according to claim 1, characterized in that, The clamp has threads at both ends.

3. The fastener for marine photovoltaic rods according to claim 1, characterized in that, The inner wall of the clamp is provided with a direct current channel, and the direction of the direct current channel is consistent with the axial direction of the clamp.

4. The fastener for marine photovoltaic rods according to claim 3, characterized in that, The inner wall of the clamp is provided with a threaded flow channel, which is connected to the direct flow channel.

5. The fastener for marine photovoltaic rods according to claim 4, characterized in that, The inner walls at both ends of the clamp are provided with neck grooves, which are connected to the threaded flow channels.

6. The fastener for offshore photovoltaic rods according to claim 4, characterized in that, The clamp is provided with an injection hole and an exhaust hole, both of which are connected to the DC channel.

7. The fastener for marine photovoltaic rods according to claim 1, characterized in that, The outer wall of the clamp is provided with a hexagonal protrusion.

8. The fastener for marine photovoltaic rods according to claim 1, characterized in that, The clamp is divided into two halves, and both the first and second halves are provided with locking keyways and chamfered keyways that cooperate with each other.

9. The fastener for marine photovoltaic booms according to claim 1, characterized in that, The inner wall of the clamp is provided with an inner cavity reinforcing bar.

10. A marine photovoltaic rod connection system, comprising: A marine photovoltaic (PV) mast and a secondary purlin mounted on the marine PV mast, characterized in that the secondary purlin is fixed by fasteners mounted on the marine PV mast, the fasteners are filled with structural adhesive through injection holes, and the fasteners are the fasteners for marine PV masts as described in any one of claims 1 to 9.

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