Lock nut for fastening photovoltaic system and fastening method

Abstract

The invention provides a locknut for fastening a photovoltaic system and a fastening method, relates to the technical field of mountain photovoltaic construction, and aims to solve the problems that a traditional fastener is easy to loosen under a dynamic load, and an existing anti-loosing measure has many defects. The locknut comprises a bolt, a nut body, a jackscrew, a filling one-way valve, a glue solution bag ring and the like, mechanical locking is achieved through embedment of a bolt positioning groove and the jackscrew, precise glue injection is completed through cooperation of an inner channel of the jackscrew and a nut spiral groove, and mechanical and gluing dual protection is formed in cooperation with auxiliary sealing and looseness prevention of the glue solution bag ring. According to the fastening method, through the steps of pre-tightening, locking, glue injection, sealing and the like, it is ensured that a glue solution can controllably fill a thread gap, and the anti-loosening reliability is improved. The fastening device is convenient to mount and high in maintainability, adapts to fastening scenes such as photovoltaic panels and concrete supports, and meets the use requirements of high reliability and long service life.

Description

Technical Field

[0001] This invention relates to the field of mountain photovoltaic construction technology, specifically to an anti-loosening nut and a fastening method for photovoltaic systems. Background Technology

[0002] With the rapid development of photovoltaic power generation technology, the installation stability of photovoltaic systems has become a key factor affecting the long-term reliable operation of the system. Traditional photovoltaic support fasteners (such as bolts and nuts) are prone to fretting wear between threaded pairs under dynamic loads such as long-term wind vibration, temperature difference changes, and mechanical vibration, leading to a decrease in preload or even loosening. This can cause safety hazards such as photovoltaic panel displacement, structural failure, or reduced preload of modular concrete supports and photovoltaic brackets. Currently, common anti-loosening measures (such as spring washers, double nuts, thread sealant, etc.) have disadvantages such as easy aging, cumbersome installation, or non-reusability, making it difficult to meet the photovoltaic industry's demand for highly reliable and long-life fasteners.

[0003] In existing technologies, while mechanical locking (such as set screw fixing) can improve anti-loosening performance, the direct contact between the set screw and the thread can easily damage the thread and cannot provide additional anti-loosening compensation. While adhesive injection anti-loosening technology can enhance the bonding force of the threaded pair, the flowability of the adhesive is difficult to control precisely, and may affect disassembly and maintenance after curing. Therefore, there is an urgent need for an anti-loosening structure that combines mechanical locking and dynamic adhesive injection compensation functions, ensuring high reliability in preventing loosening while also considering ease of installation and maintainability. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an anti-loosening nut and a fastening method for fastening photovoltaic systems, so as to solve the technical problem that the bolt fastening of existing flexible photovoltaic supports in mountainous areas, such as panel fastening and concrete support fastening, is prone to loosening.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A locking nut for fastening photovoltaic systems is characterized by comprising a bolt, a nut, a set screw, and a one-way valve for injection; the nut has a through radial threaded hole on its side wall, the set screw is disposed in the radial threaded hole and can be screwed into the radial threaded hole and abut against the bolt, the set screw has a channel communicating with the radial threaded hole, and the end of the set screw is connected to the one-way valve for injection, the one-way valve being used to inject locking adhesive into the nut after the bolt and nut are tightened in place.

[0006] The bolt has several axially spaced positioning grooves at the bottom thread intervals. After the set screw is screwed into the radial thread hole, it can fit into the positioning grooves of the bolt.

[0007] In the preferred embodiment, the position of the positioning groove is calculated based on the pitch of the nut and bolt and the parameters of the set screw to ensure that when the nut is tightened to the target position, at least one positioning groove can match the tip position of the set screw.

[0008] In a preferred embodiment, the nut has a toothed disc at its bottom, an internal thread in its inner hole, a spiral groove along the internal thread that communicates with the radial threaded hole, so that the internal channel of the set screw communicates with the spiral groove after it enters.

[0009] The top of the aforementioned set screw is provided with a mating threaded hole for connecting with the filling check valve. The lower end of the mating threaded hole is connected to the filling countersunk hole inside the set screw. The lower end of the filling countersunk hole is connected to multiple lateral injection slots that penetrate the side wall of the set screw. The lateral injection slots extend downward to the top tip of the set screw. The adhesive can be injected into the threaded pair gap or / and into the spiral groove through the filling countersunk hole and the lateral injection slots.

[0010] The aforementioned one-way valve is used to connect to an external pressurization pipeline, which is connected to a pressurization pump. The pressurization pipeline pressurizes the anti-loosening adhesive and pumps it into the nut through the set screw.

[0011] The aforementioned set screw is also fitted with a threaded sealing nut. The lower end face of the sealing nut is provided with a sealing ring. The sealing nut is used to seal the set screw and the side wall of the nut to prevent the anti-loosening adhesive from overflowing from the gap between the set screw and the radial threaded hole and causing pressure loss.

[0012] The aforementioned radial threaded hole sidewall has multiple radial threaded holes to avoid a single radial threaded hole facing inconveniently for installing set screws and filling check valves. Radial threaded holes without set screws are sealed with sealing screws, and sealing screws are equipped with sealing rings.

[0013] A washer is also provided below the nut. The washer is fitted onto the bolt and is located between the nut and the target fastener to enhance the sealing and cushioning performance between the nut and the target fastener.

[0014] The aforementioned nut and washer are provided with a glue bladder ring, which is sleeved on the bolt. The glue bladder ring contains glue, which gradually solidifies into a liquid upon contact with air.

[0015] The inner ring of the aforementioned adhesive bladder ring has an upwardly protruding inner edge ring. The top of the inner edge ring has multiple bladder openings. The thickness of the bladder at the bladder openings is less than that of other parts of the adhesive bladder ring, so that the bladder openings will rupture first when the nut is tightened, allowing the adhesive inside the adhesive bladder ring to be squeezed out from the inside and fill the recessed gap at the bottom of the nut, overflowing and wrapping the bottom of the nut, the washer, and the surface of the target fastener.

[0016] The depth of the positioning groove on the thread of the bolt is 0.5-2mm, the number of positioning grooves is 3-8, and the positioning grooves are evenly distributed along the circumference of the bolt.

[0017] The aforementioned set screw tip has a conical structure, and the set screw is made of high-strength alloy steel. The surface of the set screw tip has been hardened to enhance its wear resistance and compressive strength.

[0018] The gaskets mentioned above are corrugated gaskets made of stainless steel, and their surfaces are galvanized to improve their corrosion resistance.

[0019] The tightening method using the aforementioned anti-loosening nuts for photovoltaic systems includes the following steps: Step 1: Pass the bolt through the mounting hole of the target fastener, put on the washer, then screw the nut into the bolt and tighten the nut to the position corresponding to the target preload. Step 2: Screw the sealing nut into the top of the set screw; Step 3: Rotate the set screw to screw it into the radial threaded hole until the tip of the set screw is embedded in the positioning groove of the bolt, thus achieving mechanical locking; Step 4: Unscrew the sealing nut from the top of the set screw, so that the lower end face of the sealing nut fully abuts against the side wall of the nut to achieve a seal; Step 5: Seal the other radial threaded holes with sealing screws; Step 6: Connect the mating threaded hole at the top of the set screw to the injection check valve, and connect the injection check valve to the pressurization pipe. Inject pressurized anti-loosening adhesive into the set screw through the pressurization pipe. The anti-loosening adhesive is injected into the threaded joint gap and / or the spiral groove along the side injection seam until adhesive begins to overflow from the top of the nut. Stop injection, remove the pressurization pipe, and the injection check valve will shut off and seal under the pressure of the internal adhesive. After the anti-loosening adhesive gradually cools and solidifies, it will fully contact the bolt, nut, set screw, and radial threaded hole to increase the friction coefficient between the threads and prevent them from loosening.

[0020] A glue bladder ring is also inserted between the nut and the washer. The glue bladder ring is fitted onto the bolt and contains glue. The glue gradually solidifies into a liquid when it comes into contact with air. In step one, an adhesive bladder ring is placed between the nut and the washer. As the nut is tightened, the thin opening of the adhesive bladder ruptures, and the anti-loosening adhesive flows out and coats the bottom of the nut, the washer, and the surface of the target fastener.

[0021] The anti-loosening nut and fastening method for photovoltaic systems mentioned in this invention have the following beneficial effects: 1. The mechanical locking method of engaging the set screw and bolt positioning groove, combined with multi-channel pressure injection technology, forms a dual protection of "mechanical + adhesive", which greatly improves the reliability of anti-loosening under dynamic load and solves the problem of easy loosening of traditional fasteners.

[0022] 2. The set screw is hardened and the bolt positioning groove is precisely matched to enhance locking stability, avoid thread damage, and ensure the load-bearing capacity of the fastener.

[0023] 3. The spiral groove and the side injection seam fit together to ensure that the adhesive fills the thread gap evenly. The one-way valve and the sealing nut ensure stable injection pressure, prevent adhesive overflow, and improve the adhesive bonding and anti-loosening effect.

[0024] 4. The adhesive bladder ring is precisely designed to prevent adhesive leakage, and combined with a corrugated galvanized gasket, it enhances sealing and cushioning performance, resists outdoor corrosion, and extends service life.

[0025] 5. The multi-radial threaded hole design adapts to complex installation scenarios, with standardized fastening steps and a replaceable structure, balancing installation convenience and maintainability to meet the high reliability requirements of photovoltaic systems. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the anti-loosening nut tightening in this invention. Figure 1 ; Figure 2 This is a schematic diagram of the anti-loosening nut tightening in this invention. Figure 2 ; Figure 3 This is an exploded schematic diagram of the anti-loosening nut tightening in this invention; Figure 4 This is a schematic diagram of the anti-loosening nut in this invention. Figure 1 ; Figure 5 This is a schematic diagram of the anti-loosening nut in this invention. Figure 2 ; Figure 6 This is a front view of the anti-loosening nut in this invention; Figure 7 for Figure 6 Sectional view of AA; Figure 8 This is a schematic diagram of the sealing screw in this invention; Figure 9 This is a schematic diagram of the set screw structure of the present invention; Figure 10 for Figure 9 Sectional view of BB; Figure 11 This is a schematic diagram of the sealing nut structure in this invention; Figure 12 This is an exploded schematic diagram of the preferred method for tightening the anti-loosening nut in this invention; Figure 13 This is a schematic diagram of the structure of the liquid capsule in this invention; Figure 14 This is a front view of the liquid capsule in this invention. Figure 15 for Figure 14 A sectional view of CC.

[0027] Among them: bolt 1, nut 2, toothed disc 21, internal thread 22, spiral groove 23, set screw 3, lateral injection slot 301, butt threaded hole 302, injection countersunk hole 303, set screw tip 304, injection check valve 4, sealing screw 5, target fastener 6, gasket 7, sealing nut 8, radial threaded hole 9, glue bladder 10, inner edge protruding ring 101, bladder body thin opening 102, sealing ring 11. Detailed Implementation

[0028] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0029] A locking nut for fastening photovoltaic systems is characterized by comprising a bolt 1, a nut 2, a set screw 3, and a one-way valve 4; the nut 2 has a through radial threaded hole 9 on its side wall, the set screw 3 is disposed in the radial threaded hole 9 and can be screwed into the radial threaded hole 9 and abut against the bolt 1, the set screw 3 has a channel communicating with the radial threaded hole 9, and the end of the set screw 3 is connected to the one-way valve 4, the one-way valve 4 being used to inject locking adhesive into the nut 2 after the bolt 1 and the nut 2 are tightened in place.

[0030] The radial movement of the nut is prevented by the contact of the set screw. The set screw 3 has a higher hardness than the bolt 1, allowing it to fully embed into the bolt 1. Anti-loosening adhesive is injected into the nut 2 through the injection check valve 4. Under pressure, the adhesive spirals along the anti-loosening adhesive groove on the thread until the entire thread is covered with adhesive. After the adhesive solidifies, it contacts the thread contact surface of the bolt and nut in the groove, increasing the friction coefficient of the thread contact surface. This makes it more necessary to drive the nut to loosen. The check valve remains on the set screw and does not need to be removed.

[0031] The bolt 1 has several axially spaced positioning grooves at the bottom thread interval. After the set screw 3 is screwed into the radial threaded hole 9, it can fit into the positioning groove of the bolt 1.

[0032] The axial positioning groove on the bottom thread of the bolt provides an engagement point for the set screw. After the set screw is screwed in, it fits into the groove, forming a mechanical structure similar to a "buckle," which restricts the relative rotation of the nut and the bolt. Compared with simple set screw contact, the locking stability is stronger. It precisely restricts the circumferential displacement of the threaded pair, solving the problem of easy slippage when the set screw only contacts the bolt. The groove design does not compromise the overall strength of the bolt, ensuring that the load-bearing capacity of the fastener is not affected.

[0033] In the preferred embodiment, the position of the positioning groove is calculated based on the pitch of the nut 2 and the bolt 1 and the parameters of the set screw, to ensure that when the nut 2 is tightened to the target position, at least one positioning groove can match the tip position of the set screw 3.

[0034] By matching and calculating the pitch with parameters such as length and installation position of the set screw, a corresponding relationship between the positioning groove and the tip of the set screw is established. This ensures that when the nut is tightened to the target preload position, at least one groove can be precisely aligned with the set screw, eliminating the need for repeated adjustments to the nut position. This avoids the problem of the set screw failing to engage due to misalignment, improving installation efficiency; and ensures mechanical locking is achieved with each installation, guaranteeing product consistency.

[0035] In the preferred embodiment, the nut 2 has a toothed disc 21 at its bottom, an internal thread 22 in its inner hole, a spiral groove 23 along the internal thread 22 and connected to the radial threaded hole 9, so that the internal channel of the set screw 3 is connected to the spiral groove 23 after it enters.

[0036] The bottom sprocket of the nut enhances its fit with the component below, and the internal thread matches the bolt for basic fastening. A helical groove along the internal thread connects to the radial threaded hole. After the set screw enters, its internal channel forms a "passage" with the helical groove, allowing the adhesive to be evenly distributed throughout the threaded pair. The helical groove guides the adhesive to fully cover the threaded contact surface, solving the problem of localized adhesive accumulation or uneven distribution. The sprocket design improves the sealing between the nut and the component below, reducing the intrusion of external impurities.

[0037] The top of the aforementioned set screw 3 is provided with a mating threaded hole 302 for connecting with the filling check valve 4. The lower end of the mating threaded hole 302 is connected to the filling countersunk hole 303 inside the set screw 3. The lower end of the filling countersunk hole 303 is connected to a plurality of lateral injection slots 301 that penetrate the side wall of the set screw 3. The lateral injection slots 301 extend downward to the top of the set screw tip 304. The adhesive can be injected into the threaded pair gap or / and into the spiral groove 23 through the filling countersunk hole 303 and the lateral injection slots 301.

[0038] The top threaded hole of the set screw allows for a detachable connection with the injection check valve. The injection countersunk hole temporarily stores the adhesive, and multiple lateral injection slits divert the adhesive flow, ensuring it can be injected into the threaded joint gap and flow into the spiral groove. The injection slits extend to the tip of the set screw, ensuring the adhesive reaches the mating point between the set screw and the groove, enhancing the anti-loosening effect of the locking mechanism. The multi-channel injection design ensures complete adhesive coverage; the detachable connection allows for the reuse of the injection check valve, reducing costs; and the extended injection slit design strengthens the anti-loosening performance of key locking points.

[0039] The aforementioned one-way valve 4 is used to connect to an external pressurization pipeline. The pressurization pipeline is connected to a pressurization pump, which pressurizes the anti-loosening adhesive and pumps it into the nut 2 through the set screw 3.

[0040] The one-way valve, along with external pressurization pipes and a pressurization pump, forms the adhesive injection system. The pressurization pump provides stable pressure, forcing the anti-loosening adhesive through the top screw channel into the nut. The high-pressure environment causes the adhesive to quickly fill the tiny thread gaps, improving the tightness of the bond between the adhesive and the threads. High-pressure injection ensures that the adhesive fully penetrates the microscopic gaps in the threads, avoiding air bubble residue. The external pressurization equipment is adaptable to different adhesive volume requirements and suitable for various photovoltaic fastening scenarios.

[0041] The aforementioned set screw 3 is also fitted with a threaded sealing nut 8. The lower end face of the sealing nut 8 is provided with a sealing ring 11. The sealing nut 8 is used to seal the side wall of the set screw 3 and the nut 2 to prevent the anti-loosening adhesive from overflowing from the gap between the set screw 3 and the radial threaded hole 9 and causing pressure loss.

[0042] The sealing nut is threadedly connected to the set screw. Its lower end face sealing ring, after tightening, fits tightly against the nut's sidewall, forming a sealing surface. This blocks the gap between the set screw and the radial threaded hole, preventing adhesive overflow and pressure loss during injection, and ensuring stable internal injection pressure. This solves the problem of pressure loss during injection, ensuring the adhesive fills along the preset path. The sealing ring enhances sealing reliability while preventing adhesive contamination of external components, reducing cleaning difficulty.

[0043] The radial threaded hole 9 on the side wall of the aforementioned radial threaded hole 9 is provided in multiple ways to avoid a single radial threaded hole 9 facing inconveniently for installing the set screw 3 and the filling check valve 4. The radial threaded hole 9 without the set screw 3 is sealed with a sealing screw 5, and the sealing screw 5 is provided with a sealing ring 11.

[0044] Multiple radial threaded holes provide multiple installation orientation options for the set screw and the filling check valve, adapting to the complex spatial environment of photovoltaic installation sites, such as when some orientations are obstructed by brackets. Threaded holes where the set screw is not installed are sealed with sealing screws with sealing rings to ensure the overall sealing of the nut and prevent impurities from entering. This improves the product's installation flexibility and reduces on-site construction difficulty; the sealing screws, in conjunction with the sealing rings, prevent unused threaded holes from becoming weak points in the protection, ensuring the overall protective performance of the nut.

[0045] Below the aforementioned nut 2, there is also a washer 7. The washer 7 is fitted onto the bolt 1 and is located between the nut 2 and the target fastener 6, which is used to enhance the sealing and cushioning performance between the nut 2 and the target fastener 6.

[0046] The washer is fitted onto the bolt, positioned between the nut and the target fastener. Its elastic structure buffers the impact force during installation, while simultaneously filling tiny gaps between the nut and the target fastener surfaces, enhancing the seal and reducing the intrusion of external moisture and dust into the threaded joint. The corrugated structure improves cushioning performance, protecting the target fastener surface from damage; the galvanized stainless steel material enhances corrosion resistance, making it suitable for harsh outdoor photovoltaic environments and extending its service life.

[0047] A glue bladder ring 10 is provided between the nut 2 and the washer 7. The glue bladder ring 10 is sleeved on the bolt 1. The glue bladder ring 10 contains glue, which gradually solidifies into a liquid after encountering air.

[0048] The adhesive bladder ring is fitted onto the bolt, sandwiched between the nut and the washer. The adhesive inside gradually solidifies upon contact with air. When the nut is tightened, the adhesive bladder ring is compressed, causing the adhesive to overflow and fill the gap at the bottom of the nut, forming an additional adhesive sealing layer. This helps enhance the sealing performance at the bottom of the nut and, together with the internal adhesive injection into the threaded assembly, creates a "double adhesive bond" both inside and out. The air-solidification property of the adhesive prevents premature curing and ensures its activity during installation.

[0049] The inner ring of the aforementioned adhesive bladder ring 10 has an upwardly protruding inner edge ring 101. The top of the inner edge ring 101 has multiple bladder openings 102. The thickness of the bladder at the bladder opening 102 is less than that of other parts of the adhesive bladder ring 10, so that the bladder opening 102 will break first when the nut 2 is tightened, so that the adhesive inside the adhesive bladder ring 10 will be squeezed out from the inside and fill the concave gap at the bottom of the nut 2 and overflow to wrap around the bottom of the nut 2, the washer, and the surface of the target fastener 6.

[0050] The raised inner ring structure on the inner side of the adhesive bladder concentrates pressure at the top of the raised ring when the nut is tightened. The thin opening of the bladder, less thick than other parts, becomes a weak point under stress, causing it to rupture preferentially. This ensures that the adhesive is directionally extruded from the inside, precisely filling the concave gap at the bottom of the nut and wrapping the critical contact surfaces. Controlling the direction and range of adhesive extrusion prevents disorderly overflow and waste. The thin opening design ensures precise timing of rupture, synchronized with the tightening action of the nut, improving installation convenience.

[0051] The depth of the positioning groove on the thread of the bolt 1 is 0.5-2mm, the number of positioning grooves is 3-8, and the positioning grooves are evenly distributed around the circumference of the bolt 1.

[0052] A positioning groove depth of 0.5-2mm ensures stable engagement of the set screw while avoiding excessive weakening of the bolt thread strength; 3-8 evenly distributed circumferential grooves ensure that the nut can find a suitable groove at different rotation angles, improving installation flexibility. Balancing bolt strength and locking stability prevents bolt breakage due to excessively deep grooves; the evenly distributed design reduces installation alignment difficulty and improves construction efficiency.

[0053] The aforementioned set screw tip 304 has a conical structure. The set screw 3 is made of high-strength alloy steel, and the surface of the set screw tip 304 has been hardened to enhance its wear resistance and compressive strength.

[0054] The conical tip of the set screw facilitates precise insertion into the positioning groove, reducing alignment difficulty; the high-strength alloy steel material ensures the set screw's impact resistance and wear resistance, and the quenching treatment further enhances the hardness of the set screw tip, preventing deformation or wear during insertion into the groove. This extends the service life of the set screw and ensures good locking performance even after multiple disassemblies; the conical structure improves the tightness of the fit and enhances the mechanical locking effect.

[0055] The aforementioned gasket 7 is a corrugated gasket made of stainless steel, and its surface is galvanized to improve its corrosion resistance.

[0056] The elastic structure of the corrugated gasket provides continuous preload compensation force after installation, mitigating the problem of preload reduction under dynamic loads. The stainless steel material itself has a certain degree of corrosion resistance, and the galvanizing treatment forms an additional protective layer, resisting the erosion of outdoor rain and dust. This improves the fatigue resistance of fasteners, adapting to the long-term dynamic load environment of photovoltaic systems; the corrosion-resistant design extends the service life of the gasket, reducing the frequency of later maintenance and replacement.

[0057] The tightening method using the aforementioned anti-loosening nuts for photovoltaic systems includes the following steps: Step 1: Pass the bolt 1 through the mounting hole of the target fastener 6, put on the washer 7, then screw the nut 2 into the bolt 1 and tighten the nut 2 to the position corresponding to the target preload. Step 2: Screw the sealing nut 8 into the top of the set screw 3; Step 3: Rotate the set screw 3 so that it is screwed into the radial threaded hole 9 until the tip of the set screw 304 is embedded in the positioning groove of the bolt 1 to achieve mechanical locking. Step 4: Unscrew the sealing nut 8 from the top of the set screw 3 so that the lower end face of the sealing nut 8 fully abuts against the side wall of the nut 2 to achieve a seal; Step 5: Seal the other radial threaded holes 9 with sealing screws 5; Step 6: Connect the mating threaded hole 302 at the top of the set screw 3 to the injection check valve 4. Connect the injection check valve 4 to the pressurization pipe. Inject pressurized anti-loosening adhesive into the set screw 3 through the pressurization pipe. The anti-loosening adhesive is injected into the threaded pair gap and / or into the spiral groove 23 along the side injection seam 301 until adhesive begins to overflow from the top of the nut 2. Stop injection and remove the pressurization pipe. The injection check valve 4 is shut off and sealed under the pressure of the internal adhesive. After the anti-loosening adhesive gradually cools and solidifies, it fully contacts the bolt 1, nut 2, set screw 3, and radial threaded hole 9 to increase the friction coefficient between the threads and prevent them from loosening.

[0058] Step one ensures the foundation's tightness through pre-tightening; steps two through four achieve a smooth connection between the set screw locking and sealing through the installation and adjustment of the sealing nut; step five seals any excess threaded holes to ensure the injection pressure; step six uses pressurized injection to fill the adhesive along a preset path, with a one-way valve ensuring no leakage before the adhesive cures, ultimately forming a stable and anti-loosening structure. Standardized procedures ensure consistent installation quality; the criteria for judging when adhesive overflow is intuitive and easy to operate, lowering the construction threshold; the one-way valve is retained without disassembly, providing the possibility for secondary injection during later maintenance.

[0059] A glue bladder ring 10 is also inserted between the nut 2 and the washer 7. The glue bladder ring 10 is sleeved on the bolt 1. The glue bladder ring 10 contains glue, which gradually solidifies into a liquid after encountering air. In step one, an adhesive bladder ring 10 is placed between the nut 2 and the washer 7. As the nut 2 is tightened, the thin opening 102 of the adhesive bladder 10 is ruptured, and the anti-loosening adhesive flows out and wraps around the bottom of the nut 2, the washer, and the surface of the target fastener 6.

[0060] In step one, an adhesive bladder is added between the nut and the washer. The pressure of tightening the nut causes the bladder's thin opening to rupture, allowing the adhesive to flow out and coat the bottom of the nut, the washer, and the surface of the target fastener, forming an external sealing layer. This, combined with the internal thread adhesive injection, creates "double protection from both inside and outside." This enhances overall sealing performance, preventing external moisture and impurities from entering the threaded joint. The adhesive also coats key contact surfaces, further improving anti-loosening performance and making it suitable for humid and dusty outdoor photovoltaic environments.

[0061] Example 1: In this embodiment, the anti-loosening nuts for fastening the photovoltaic system are used to fasten the modular concrete support to the photovoltaic bracket. The parameters of each component are as follows: 1. Component parameter selection Bolt 1: M18 high-strength bolt, material is 35CrMo, surface Dacromet treatment; 6 axial positioning grooves are machined at the bottom thread, the groove depth is 1.2mm, evenly distributed along the circumference of the bolt, the axial spacing between adjacent grooves is 6mm, and the groove cross section is semi-circular.

[0062] Nut 2: Matches M18 bolt, made of the same material as the bolt, with an M18 internal thread 22 in the inner hole, and a spiral groove 23 with a width of 2mm and a depth of 1mm along the internal thread; three through radial threaded holes 9 with a diameter of 10mm are opened on the side wall, with a hole spacing of 120°, and the internal thread of the threaded holes is M10.

[0063] Set screw 3: The material is 40Cr, the surface is hardened, and the whole is an M10 external thread structure; the top mating thread hole 302 is M8 and the depth is 15mm; the filling countersunk hole 303 has a diameter of 5mm and a depth of 25mm; there are 4 side injection slots 301, each 1mm wide and 0.8mm deep, extending to the conical set screw tip 304.

[0064] 4. Filling one-way valve: Select a miniature brass one-way valve with an M8 external thread adapter to the set screw threaded hole. Rated working pressure is 0-3MPa, allowing adhesive to flow in one direction.

[0065] The adhesive bladder ring 10 is made of aging-resistant nitrile rubber with an inner diameter of 18mm, an outer diameter of 30mm, and a thickness of 5mm. The inner edge protrusion ring 101 is 2mm high, and the top has 4 bladder openings 102, which are filled with anaerobic thread-locking adhesive.

[0066] Other components: The sealing nut 8 is an M12 stainless steel nut with a fluororubber sealing ring 11 on the lower end face; the sealing screw 5 is an M10 internal hexagonal stainless steel screw with a sealing ring of the same specification on the head; the gasket 7 is a stainless steel corrugated gasket with galvanized surface treatment.

[0067] 2. Tightening procedures Step 1: Pre-tightening installation: Pass the bolt 1 through the mounting hole of the photovoltaic concrete support, put on the washer 7 and the adhesive bladder ring 10 in sequence, and then screw in the nut 2; use a torque wrench to tighten the nut to the pre-tightening force. At this time, the adhesive bladder ring 10 is squeezed, the thin opening 102 of the bladder body breaks, and the adhesive overflows and wraps around the bottom of the nut, the washer and the surface of the support.

[0068] Step 2: Pre-installation of sealing nut: Screw the sealing nut 8 into the top of the set screw 3 to ensure that the sealing ring 11 is not deformed by pressure, so as to facilitate subsequent installation and adjustment of the set screw.

[0069] Step 3: Set screw mechanical locking: Select one of the radial threaded holes 9, screw the set screw 3 into the hole, and slowly tighten it with a torque wrench until the set screw tip 304 is fully embedded in the bolt positioning groove. At this time, shake the nut by hand and there should be no obvious displacement.

[0070] Step 4: Seal adjustment: Rotate the sealing nut 8 in the opposite direction to make the sealing ring 11 on its lower end face fit tightly against the side wall of the nut 2, and continue to tighten the sealing nut to ensure there is no gap.

[0071] Step 5: Seal the extra holes: Tighten the other two radial threaded holes 9 without set screws with sealing rings using sealing screws 5 to complete the sealing of the nut sidewalls.

[0072] Step Six: Pressurized Injection: Screw the injection check valve 4 into the threaded hole 302 of the set screw. Connect the other end of the check valve to the pressurization pipe, which is connected to a manual pressurization pump. Inject the anti-loosening adhesive into the pump and slowly pressurize to 1.5 MPa. Continue injecting adhesive until adhesive overflows from the top of nut 2. Turn off the pressurization pump, disconnect the pipe, and the injection check valve will automatically shut off and seal under the internal adhesive pressure. Let it sit at room temperature for 20 minutes to allow the adhesive to fully cure.

[0073] 3. Implementation effect verification Anti-loosening performance: Dynamic vibration test shows that the preload attenuation rate is ≤5%, which is much lower than that of traditional double nuts.

[0074] Sealing performance: After 500 hours of salt spray testing, there was no rust inside the threaded pair and no moisture intrusion at the part wrapped by the adhesive ring.

[0075] Maintainability: After softening the adhesive layer with a heating gun, the set screw and nut can be easily removed without damage to the parts, and they can be reused after re-applying adhesive.

Claims

1. A locking nut for fastening photovoltaic systems, characterized in that, Includes bolt (1), nut (2), set screw (3), and injection check valve (4); the nut (2) has a through radial threaded hole (9) on its side wall, the set screw (3) is disposed in the radial threaded hole (9), and the set screw (3) can be screwed into the radial threaded hole (9) and abut against the bolt (1), the set screw (3) has a channel that communicates with the radial threaded hole (9), and the end of the set screw (3) is connected to the injection check valve (4). The injection check valve (4) is used to inject anti-loosening adhesive into the nut (2) after the bolt (1) and nut (2) are tightened in place.

2. The anti-loosening nut for photovoltaic system fastening according to claim 1, characterized in that, The bolt (1) has several axially spaced positioning grooves at the bottom thread interval. After the set screw (3) is screwed into the radial thread hole (9), it can fit into the positioning groove of the bolt (1).

3. The anti-loosening nut for photovoltaic system fastening according to claim 2, characterized in that, The position of the positioning groove is calculated based on the pitch of the nut (2) and the bolt (1) and the parameters of the set screw, to ensure that when the nut (2) is tightened to the target position, at least one positioning groove can match the tip position of the set screw (3).

4. The anti-loosening nut for photovoltaic system fastening according to claim 1, characterized in that, The nut (2) is provided with a toothed disc (21) at the bottom and an internal thread (22) in the inner hole of the nut (2). A spiral groove (23) is provided along the internal thread (22) and is connected to the radial thread hole (9), so that the internal channel of the set screw (3) is connected to the spiral groove (23) after it enters.

5. The anti-loosening nut for photovoltaic system fastening according to claim 4, characterized in that, The top of the set screw (3) is provided with a mating threaded hole (302) for connecting with the filling check valve (4). The lower end of the mating threaded hole (302) is connected to the filling countersunk hole (303) in the set screw (3). The lower end of the filling countersunk hole (303) is connected to a plurality of lateral injection slots (301) that penetrate the side wall of the set screw (3). The lateral injection slots (301) extend downward to the top tip of the set screw (304). The adhesive can be injected into the threaded pair gap or / and into the spiral groove (23) through the filling countersunk hole (303) and the lateral injection slots (301).

6. The anti-loosening nut for photovoltaic system fastening according to claim 5, characterized in that, The filling check valve (4) is used to connect to an external pressurization pipeline. The pressurization pipeline is connected to a pressurization pump. The pressurization pipeline pressurizes the anti-loosening adhesive and pumps it into the nut (2) through the set screw (3).

7. The anti-loosening nut for photovoltaic system fastening according to claim 6, characterized in that, The set screw (3) is also fitted with a threaded sealing nut (8). The lower end face of the sealing nut (8) is provided with a sealing ring (11). The sealing nut (8) is used to seal the side wall of the set screw (3) and the nut (2) to prevent the anti-loosening adhesive from overflowing from the gap between the set screw (3) and the radial threaded hole (9) and causing pressure loss.

8. The anti-loosening nut for photovoltaic system fastening according to claim 1, characterized in that, The radial threaded hole (9) on the side wall of the radial threaded hole (9) is provided with multiple radial threaded holes (9) to avoid a single radial threaded hole (9) facing the direction that is not convenient for installing the set screw (3) and the filling check valve (4). The radial threaded hole (9) without the set screw (3) is sealed with a sealing screw (5), and a sealing ring (11) is provided on the sealing screw (5).

9. The anti-loosening nut for photovoltaic system fastening according to claim 1, characterized in that, A washer (7) is provided below the nut (2). The washer (7) is fitted on the bolt (1) and is located between the nut (2) and the target fastener (6) to enhance the sealing and buffering performance between the nut (2) and the target fastener (6).

10. The anti-loosening nut for photovoltaic system fastening according to claim 9, characterized in that, A glue bladder ring (10) is provided between the nut (2) and the washer (7). The glue bladder ring (10) is sleeved on the bolt (1). The glue bladder ring (10) contains glue, which gradually solidifies into liquid after encountering air.

11. The anti-loosening nut for photovoltaic system fastening according to claim 10, characterized in that, The inner ring of the adhesive bladder ring (10) is provided with an upwardly protruding inner edge ring (101). The top of the inner edge ring (101) is provided with multiple bladder openings (102). The thickness of the bladder at the bladder opening (102) is less than that of other parts of the adhesive bladder ring (10), so that the bladder opening (102) breaks first when the nut (2) is tightened, so that the adhesive inside the adhesive bladder ring (10) is squeezed out from the inside and fills the recessed gap at the bottom of the nut (2) and overflows to wrap the bottom of the nut (2), the washer and the surface of the target fastener (6).

12. The anti-loosening nut for photovoltaic system fastening according to claim 2, characterized in that, The positioning groove on the thread of the bolt (1) has a depth of 0.5-2mm, the number of positioning grooves is 3-8, and the positioning grooves are evenly distributed along the circumference of the bolt (1).

13. The anti-loosening nut for photovoltaic system fastening according to claim 5, characterized in that, The set screw tip (304) is a conical structure. The set screw (3) is made of high-strength alloy steel, and the surface of the set screw tip (304) has been quenched to enhance its wear resistance and compressive strength.

14. The anti-loosening nut for photovoltaic system fastening according to claim 9, characterized in that, The gasket (7) is a corrugated gasket. The gasket (7) is made of stainless steel and its surface is galvanized to improve its corrosion resistance.

15. A fastening method using the anti-loosening nut for photovoltaic system fastening as described in claim 7, characterized in that, Includes the following steps: Step 1: Pass the bolt (1) through the mounting hole of the target fastener (6), put on the washer (7), then screw the nut (2) into the bolt (1) and tighten the nut (2) to the position corresponding to the target preload. Step 2: Screw the sealing nut (8) into the top of the set screw (3); Step 3: Rotate the set screw (3) to screw the set screw (3) into the radial threaded hole (9) until the tip of the set screw (304) is embedded in the positioning groove of the bolt (1) to achieve mechanical locking; Step 4: Unscrew the sealing nut (8) from the top of the set screw (3) so that the lower end face of the sealing nut (8) fully abuts against the side wall of the nut (2) to achieve a seal; Step 5: Seal the other radial threaded holes (9) with sealing screws (5); Step 6: Connect the mating threaded hole (302) at the top of the set screw (3) to the injection check valve (4), and connect the injection check valve (4) to the pressurization pipe. Inject pressurized anti-loosening adhesive into the set screw (3) through the pressurization pipe. The anti-loosening adhesive is injected into the threaded pair gap or / and into the spiral groove (23) along the side injection seam (301) until adhesive begins to overflow from the top of the nut (2). Stop the injection, remove the pressurization pipe, and the injection check valve (4) is shut off and sealed under the pressure of the internal adhesive. After the anti-loosening adhesive gradually cools and solidifies, it fully contacts the bolt (1), nut (2), set screw (3), and radial threaded hole (9) to increase the friction coefficient between the threads and prevent them from loosening.

16. The fastening method for the anti-loosening nut for photovoltaic system fastening according to claim 15, characterized in that, A glue bladder ring (10) is also inserted between the nut (2) and the washer (7). The glue bladder ring (10) is sleeved on the bolt (1). The glue bladder ring (10) contains glue, which gradually solidifies into liquid after encountering air. In step one, an adhesive bladder ring (10) is placed between the nut (2) and the washer (7). When the nut (2) is tightened, the thin opening (102) of the adhesive bladder (10) is broken, and the anti-loosening adhesive flows out and wraps the bottom of the nut (2), the washer and the surface of the target fastener (6).

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