Outer-bolt and inner-anchor type flange connecting joint

Abstract

The invention discloses an outer bolt and inner anchor type flange connection joint, and belongs to the technical field of steel structure engineering. The joint aims at solving the technical problems that equal-strength connection between a large-diameter thick-wall steel pipe and a component is difficult to achieve through traditional flange connection, and existing joint connection is low in rigidity and eccentric in stress. According to the technical scheme, the device is characterized by comprising a steel pipe end plate coaxially welded with a to-be-spliced steel pipe, the inner diameter of an annular plate structure is matched with the outer diameter of a sleeve, and the sleeve penetrates through the other side of the end plate to be welded and is provided with an internal thread; the mounting ring plate is fixedly connected with the screw rod through the center hole, the screw rod is provided with an external thread matched with the internal thread of the sleeve, and the mounting ring plate is provided with a second bolt hole; the two ends of the screw are screwed into the two symmetrical sleeves, so that the first bolt holes and the second bolt holes in the two ends are correspondingly communicated, and the high-strength bolts penetrate into the first bolt holes and the second bolt holes to achieve fastening. The joint is mainly used for splicing steel pipes in large-scale steel structure engineering, and can be manufactured in a standardized mode, installed rapidly and used repeatedly in a detachable mode.

Description

Technical Field

[0001] This invention relates to the field of steel structure engineering technology. More specifically, this invention relates to an external bolt and internal anchor flange connection node. Background Technology

[0002] In the field of steel structure engineering, steel pipe structures are widely used in large-span spatial structures, high-rise buildings, industrial plants, and bridge towers due to their excellent mechanical properties and construction efficiency. Reliable connections between steel pipes are crucial for ensuring the overall structural safety. Currently, on-site splicing of steel pipe structures mainly employs welding and flange connections.

[0003] Welding can achieve a connection of equal strength between nodes and component materials, providing high rigidity and sealing. However, welding operations require a high level of skill from the operating environment and technicians, and the quality of on-site welding is difficult to guarantee. More importantly, welding results in a non-removable, permanent connection, which cannot meet the needs of some projects requiring repeated disassembly and reversible construction.

[0004] Flange connections, as a detachable mechanical connection method, have solved the problem of ease of assembly and disassembly to some extent. However, in practical applications, it has been found that traditional flange connections have significant limitations for large-diameter, thick-walled steel pipes subjected to large tensile forces or dynamic loads. The force transmission path relies on the preload of the bolts and the friction of the flange contact surface. When the joint is subjected to axial tensile force, the load is mainly transmitted through the bolt shank. The bolt shank itself is a slender rod with limited tensile stiffness, and it is prone to significant elastic elongation under high stress, leading to increased joint deformation and making it difficult to achieve a connection with the same strength as the steel pipe component. Furthermore, significantly increasing the number of bolts or the flange plate thickness to meet strength requirements will significantly increase the weight of the joint and material costs, and also make on-site alignment and installation more difficult.

[0005] Therefore, there is an urgent need in engineering practice for a new type of steel pipe connection node. It should not only meet the stringent requirements of large-diameter thick-walled steel pipes for connection strength under high load conditions and achieve connection performance with the same or near-equal strength as the components, but also retain the convenience of detachable connection. At the same time, it should simplify on-site installation operations, reduce the difficulty of alignment and adjustment, and improve construction efficiency and accuracy. Summary of the Invention

[0006] One objective of this invention is to provide an external bolt and internal anchor flange connection node for steel pipe splicing in large steel structure projects, which can achieve standardized manufacturing, rapid installation and disassembly and reuse.

[0007] To achieve these objectives and other advantages of the present invention, according to one aspect of the present invention, an external bolt and internal anchor flange connection node is provided, comprising a steel pipe end plate, a sleeve, a bolt, and a mounting ring plate; One side of the steel pipe end plate is coaxially welded to the steel pipe to be spliced. The steel pipe end plate is a ring plate structure, and its inner diameter matches the outer diameter of the sleeve. The sleeve is coaxially inserted into and fixedly connected to the other side of the steel pipe end plate. The steel pipe end plate has multiple first bolt holes along the circumference. The inner side wall of the sleeve is provided with internal threads. The mounting ring plate has a central hole along the axis, the inner diameter of which matches the outer diameter of the screw. The screw passes through the mounting ring plate coaxially and is fixedly connected to it. The outer wall of the screw is provided with an external thread that matches the internal thread. The mounting ring plate has multiple second bolt holes along the circumference. The two ends of the screw are coaxially screwed into the sleeves of two symmetrical steel pipe end plates, and the first bolt holes on the two steel pipe end plates and the second bolt holes on the mounting ring plate are connected. High-strength bolts are inserted into the connected first and second bolt holes to achieve connection and fastening.

[0008] Preferably, multiple ribs are welded perpendicularly along the circumference between the end of the steel pipe end plate and the outer wall of the steel pipe to be spliced.

[0009] Preferably, the steel pipe to be spliced, the steel pipe end plate, and the sleeve are fixedly connected as a whole by welding.

[0010] Preferably, the screw and the mounting ring plate are fixedly connected as one unit by welding.

[0011] Preferably, the outer side wall of the screw is evenly distributed with multiple spacer teeth along the circumference. The length of the spacer teeth along the screw axis matches the thickness of the mounting ring plate. The spacer teeth are not continuous. The mounting ring plate has a toothed groove that mates with the multiple spacer teeth along the circumference in the central hole. The screw and the mounting ring plate are screwed and fixedly connected as a whole by the matching spacer teeth and toothed groove.

[0012] Preferably, the engagement of the spacer plate and the toothed groove allows the mounting ring plate to rotate unidirectionally relative to the screw; When the mounting ring plate rotates in the first direction, the spacer tooth plate engages with the toothed groove, driving the screw to rotate synchronously; When the mounting ring plate rotates in a second direction opposite to the first direction, the spacer tooth plate disengages from the toothed groove, and the mounting ring plate can rotate independently. Its rotation angle is consistent with the included angle between the centers of two adjacent second bolt holes in the circumferential direction.

[0013] Preferably, the tooth pitch of the spacer plate is coordinated with the hole spacing of the first bolt hole and the second bolt hole.

[0014] Preferably, all the spacer plates are trapezoidal tooth structures with a tooth tip angle of 60-90°.

[0015] This invention offers at least the following beneficial effects: It provides an external bolt and internal anchor flange connection node. By embedding a sleeve inside the end plate and welding it into a whole, then screwing a bolt into the sleeve to achieve connection, and finally tightening with high-strength bolts, a force transmission mechanism combining internal anchoring and external bolting is formed. This significantly enhances the load-bearing capacity and stiffness of the node under tension, enabling the connection node to achieve a strength level similar to that of steel pipe components, while retaining detachability. By adding ribs between the end plate and the outer wall of the steel pipe, the force in the node area is more effectively distributed and transferred to the steel pipe body, improving the overall stiffness and bending resistance of the node. Welding connects the components into a whole, ensuring the connection strength and integrity of the node. The matching design of the spacer toothed plate and toothed groove allows controllable unidirectional relative rotation, solving the problem of bolt hole misalignment during installation. Its specific working mechanism allows for independent adjustment of the installation ring plate alignment after tightening the bolt, while the coordinated design of the tooth pitch and hole pitch achieves mechanical positioning, significantly improving installation accuracy and efficiency. The trapezoidal tooth profile with a specific angle optimizes the mechanical properties of the tooth root, improves shear resistance and wear resistance, and ensures the long-term reliability of the mechanism.

[0016] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the external bolt and internal anchor flange connection node in one technical solution of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the external bolt and internal anchor flange connection node in one technical solution of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the structure of the steel pipe end plate in one technical solution of the present invention. Figure 1 ; Figure 4 This is a schematic diagram of the structure of the steel pipe end plate in one technical solution of the present invention. Figure 2 ; Figure 5 This is a schematic diagram of the structure of the screw and mounting ring plate in one technical solution of the present invention. Figure 1 ; Figure 6 This is a schematic diagram of the structure of the screw and mounting ring plate in one technical solution of the present invention. Figure 2 ; Figure 7 This is a schematic diagram of the structure of the external bolt and internal anchor flange connection node in another technical solution of the present invention; Figure 8This is a schematic diagram of the screw structure in another technical solution of the present invention; Figure 9 This is a schematic diagram of the mounting ring plate in another technical solution of the present invention. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can implement it based on the description.

[0019] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0020] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0021] like Figure 1-6 As shown, the present invention provides an external bolt and internal anchor flange connection node, including a steel pipe end plate 1, a sleeve 2, a bolt 3 and a mounting ring plate 4; One side of the steel pipe end plate 1 is coaxially welded to the steel pipe to be spliced. The steel pipe end plate 1 is a ring plate structure, and its inner diameter matches the outer diameter of the sleeve 2. The sleeve 2 is coaxially inserted into and fixedly connected to the other side of the steel pipe end plate 1. The steel pipe end plate 1 is provided with a plurality of first bolt holes 11 along the circumference. The inner side wall of the sleeve 2 is provided with internal threads 22. The mounting ring plate 4 has a central hole 42 along the axis, the inner diameter of which matches the outer diameter of the screw 3. The screw 3 passes through the mounting ring plate 4 coaxially and is fixedly connected to it. The outer side wall of the screw 3 is provided with an external thread 31 that matches and screws into the internal thread 22. The mounting ring plate 4 has a plurality of second bolt holes 41 along the circumference. The two ends of the screw 3 are coaxially screwed into the sleeves 2 of two symmetrical steel pipe end plates 1, and the first bolt holes 11 on the two steel pipe end plates 1 and the second bolt holes 41 on the mounting ring plate 4 are connected. High-strength bolts 5 are inserted into the corresponding connected first bolt holes 11 and second bolt holes 41 to achieve connection and fastening.

[0022] In the above technical solution, the external bolt and internal anchor flange connection node includes a steel pipe end plate 1, a sleeve 2, a bolt 3, and an mounting ring plate 4. The steel pipe end plate 1 can be a ring-shaped steel plate made of low-carbon alloy steel, with a material grade of Q345B or Q355B. The sleeve 2 can be a cylindrical component made of medium-carbon steel, with a material grade of 45 steel. The inner diameter of the steel pipe end plate 1 and the outer diameter of the sleeve 2 are interference-fitted, with a tolerance grade of H7 / k6. During assembly, the sleeve 2 is first pressed into the steel pipe end plate 1 from one side, and then continuous fillet welds are performed circumferentially, with the weld height controlled within the range of 6 mm to 10 mm. Bolt holes are evenly spaced along the circumference of the steel pipe end plate 1, with a hole diameter 1 mm to 2 mm larger than the nominal diameter of the high-strength bolt 5, and the hole spacing is 3 to 4 times the hole diameter. The sleeve 2 has a central hole 21 along the axis, and the steel pipe end plate 1 has a central hole 12 along the axis.

[0023] The mounting ring plate 4 can be made of the same material as the steel pipe end plate 1. The screw 3 can be a double-ended stud made of alloy structural steel, and the material can be 40Cr or 42CrMo. The screw 3 and the mounting ring plate 4 are connected by welding, and the weld penetration depth can be controlled between 3 mm and 5 mm. The diameter of the center hole 42 of the mounting ring plate and the outer diameter of the screw 3 adopt a transition fit, and the fit tolerance can be H7 / h6. The bolt holes on the mounting ring plate 4 correspond exactly to the bolt holes on the steel pipe end plate 1, and the hole diameter tolerance is controlled at level H13.

[0024] The wall thickness t of sleeve 2 c The wall thickness t of the connected steel pipe p Proportional relationship, specifically t c =k1×t p The proportionality coefficient k1 is an empirical constant derived from extensive mechanical analysis and experimental verification, ranging from 0.5 to 0.8. This ensures that the sleeve 2 has sufficient strength to participate in the load-bearing process, and its wall thickness is neither too thin (leading to insufficient strength or weld burn-through) nor too thick (leading to poor economy and excessive weld residual stress). The screw 3 has a diameter d. s Satisfying formula d s =k2×D p ; where D p The outer diameter of the connected steel pipe is given. The proportionality coefficient k2 is another key empirical constant, ranging from 0.08 to 0.12. This formula directly relates to the dimensions of the core force-transmitting element (screw 3) and the overall component dimensions, ensuring that the tensile stiffness of screw 3 matches the tensile stiffness of the steel pipe. This is the core design principle for achieving the goal of "equal strength connection." The thickness t of the steel pipe end plate 1 is also given. e Satisfying formula t e =k3×t pThe proportionality coefficient k3 ranges from 1.2 to 1.5. This formula ensures that the flange end plate has sufficient out-of-plane stiffness, effectively resists bending deformation under tension, ensures that pressure is evenly transmitted to the gasket, and provides stable support for the bolts.

[0025] During assembly, first screw the bolt 3 into the internal thread 22 of the sleeve 2 on one side, then align the sleeve 2 of the steel pipe end plate 1 on the other side with the bolt 3, and gradually screw the bolt 3 in by rotating the mounting ring plate 4. Once the contact surfaces of the steel pipe end plates 1 and the mounting ring plate 4 are tightly fitted, adjust the angle of the mounting ring plate 4 to align the bolt holes, and finally insert the high-strength bolt 5 and tighten it to the specified torque value. The high-strength bolt 5 can be a hexagonal head bolt with a performance grade of 8.8 or 10.9. The torque value can be calculated based on the bolt specifications and material strength, generally controlled within the range of 200 Nm to 800 Nm.

[0026] This external bolt and internal anchor flange connection achieves multiple beneficial effects through its unique structural design. The connection utilizes an internal sleeve 2, welded to the steel pipe end plate 1, forming a stable internal anchor structure. This construction significantly improves the axial tensile stiffness and load-bearing capacity of the connection, allowing the connection strength to reach a level similar to that of the steel pipe itself. Simultaneously, the threaded engagement of the bolt 3 with the sleeve 2 enables adjustable connection length, facilitating on-site installation. In terms of load-bearing performance, this connection creates a dual force transmission path. The threaded connection between the bolt 3 and the sleeve 2 bears the main tensile force, while the surrounding high-strength bolt group 5 provides additional tightening force and shear resistance. This clearly defined force transmission mechanism ensures stable mechanical properties under various load conditions. The standardized dimensions of all components ensure uniform and reliable stress distribution. During installation, the connection exhibits good construction adaptability. The threaded engagement of the bolt 3 with the sleeve 2 provides self-centering capability, reducing installation accuracy requirements. The bolt holes on the mounting ring plate 4 and the steel pipe end plate 1 are arranged at equal intervals, and the hole diameters are precisely calculated to ensure both smooth bolt insertion and sufficient contact area. The tightening sequence and torque values ​​of the high-strength bolts 5 are clearly defined, ensuring the stability of installation quality. This node also features good disassembly and reusability. The node can be easily disassembled by loosening the high-strength bolts 5 and rotating the screw 3. No permanent deformation occurs after disassembly, allowing for multiple reuses. This characteristic is particularly suitable for engineering scenarios requiring temporary assembly or later adjustments, effectively improving material utilization. In terms of manufacturing processes, all components of the node can be produced using conventional machining methods, without the need for special equipment or complex processes. The steel pipe end plate 1 can be cut using flame cutting or plasma cutting, the sleeve 2 can be machined from seamless steel pipe, and the screw 3 can be machined using standard thread processing. This manufacturing convenience helps ensure product quality stability and the feasibility of mass production.

[0027] In another technical solution, multiple ribs 6 are welded perpendicularly along the circumference between the end of the steel pipe end plate 1 and the outer wall of the steel pipe to be spliced.

[0028] In the above technical solution, the rib plate 6 can be made of low-carbon structural steel plate, and the material can be Q235B or Q345B grade. The shape of the rib plate 6 can be a right triangle or trapezoid, the thickness can be set to 8 mm to 20 mm, and the height can be controlled within the range of 80 mm to 150 mm. The rib plates 6 are evenly arranged along the circumferential direction of the back of the steel pipe end plate 1, and the number can be determined according to the pipe diameter, usually 4 to 12 pieces can be set. One right-angled side of the rib plate 6 is welded perpendicularly to the back of the steel pipe end plate 1, and the other right-angled side is welded to the outer wall of the steel pipe to be spliced.

[0029] Regarding the welding process, the connection between rib plate 6 and the steel pipe end plate 1, as well as the steel pipe to be spliced, can be achieved using manual arc welding or gas shielded welding. A double-sided fillet weld can be used, with the weld leg size controlled between 6 mm and 10 mm. A symmetrical welding sequence should be adopted during welding to reduce welding deformation. After welding, a visual inspection and non-destructive testing of the weld are required to ensure that the weld quality meets relevant standards. The weld length connecting rib plate 6 and steel pipe end plate 1 should be no less than half the height of rib plate 6.

[0030] The structure works as follows: When the node is under load, the rib 6 effectively transfers the force on the steel pipe end plate 1 to the pipe body to be spliced. The rib 6, through its in-plane stiffness, constrains the deformation of the steel pipe end plate 1 relative to the steel pipe, improving the overall stability of the node. When subjected to bending moment, the rib 6 provides additional bending stiffness, reducing stress concentration at the root of the steel pipe end plate 1. By rationally setting the size and number of ribs 6, the stress on the node can be made more uniform, avoiding excessive local stress.

[0031] This type of connection node with ribs 6 improves the overall stiffness and load-bearing capacity of the node, making it particularly suitable for applications subjected to large bending moments or dynamic loads. The addition of ribs 6 enhances the local stability of the node area and reduces the potential deformation of the steel pipe end plate 1. Simultaneously, this structure maintains the node's detachability without affecting its primary connection function. The addition of ribs 6 facilitates smoother force transmission and improves the node's stress performance.

[0032] In another technical solution, the steel pipe to be spliced, the steel pipe end plate 1, and the sleeve 2 are fixedly connected as a whole by welding.

[0033] In the above technical solution, the welding method can be a commonly used welding process such as manual arc welding, CO2 gas shielded welding, or submerged arc welding. The welding materials can be welding rods or wires with strength matching that of the base material. For the Q345B steel pipe end plate 1 and sleeve 2, E50 series welding rods or ER50-6 welding wire can be used. The welding positions are located at the butt joint circumferential weld between the steel pipe end plate 1 and the steel pipe to be spliced, and at the circumferential fillet weld between the sleeve 2 and the inner hole of the steel pipe end plate 1. Before welding, the bevel needs to be cleaned to remove oil and rust, and preheating treatment should be performed as required. The preheating temperature can be controlled between 120°C and 150°C.

[0034] Welding process parameters are determined based on plate thickness and material grade. Welding current can be set between 180 and 280 amps, and arc voltage can be controlled between 22 and 30 volts. Welding speed should be maintained within a certain range; for manual welding, it can be controlled between 150 and 250 mm / min, while for automatic welding, it can be appropriately increased. Weld leg size is determined based on the thickness of the connecting parts; for steel plates with a thickness of 20 to 50 mm, the weld leg size can be set between 8 and 12 mm. Interpass temperature needs to be controlled during welding, and should not exceed 250 degrees Celsius.

[0035] After welding, weld quality inspection is required, including visual inspection, non-destructive testing, and mechanical property testing. Visual inspection requires that the weld surface be free of defects such as cracks, porosity, and slag inclusions, and the weld reinforcement should be controlled within the range of 0 mm to 3 mm. Non-destructive testing can be performed using ultrasonic testing or radiographic testing; the inspection ratio is determined according to the importance of the structure, with important welds potentially requiring 100% inspection. Mechanical property testing can involve sampling for tensile and bending tests to verify that the weld strength is not lower than the standard value of the base material.

[0036] This welding connection method forms a unified load-bearing unit with the steel pipe to be spliced, the pipe end plate 1, and the sleeve 2, improving the integrity and rigidity of the joint. Welding ensures effective load transfer between components and avoids the loosening problems that can occur with bolted connections. Simultaneously, the welded connection offers excellent sealing and fatigue resistance, making it suitable for applications subjected to dynamic loads. Although this connection method is non-removable, it provides higher reliability and stability.

[0037] In another technical solution, the screw 3 and the mounting ring plate 4 are fixedly connected as one unit by welding.

[0038] In the above technical solution, the welding method can be a commonly used welding process such as manual arc welding, tungsten inert gas welding, or gas shielded welding. The welding materials can be welding rods or wires with strength matching that of the base material. For the 40Cr material screw 3 and the Q355B material mounting ring plate 4, E5015 welding rods or ER50-6 welding wires can be used. The welding position is located in the contact area around the end of the screw 3 and the center hole 42 of the mounting ring plate, using a full-circumference fillet weld. Before welding, the welding area needs to be cleaned to remove oil and rust, and the screw 3 needs to be preheated. The preheating temperature can be controlled within the range of 150 degrees Celsius to 200 degrees Celsius.

[0039] The weld joint design uses fillet welds, with the weld leg size determined based on the component thickness. For screws with diameters of 30 mm to 60 mm, the weld leg size can be set to 6 mm to 10 mm. The welding current can be set between 160 amps and 240 amps, and the arc voltage can be controlled between 22 volts and 28 volts. The welding speed should be maintained within an appropriate range, which can be controlled between 100 mm / min and 200 mm / min for manual welding. Interpass temperature needs to be controlled during welding, not exceeding 300 degrees Celsius. Slow cooling treatment is required after welding to prevent weld cracking.

[0040] Welding quality inspection includes visual inspection, non-destructive testing (NDT), and mechanical property testing. Visual inspection requires a uniform and smooth weld surface, free from defects such as cracks, porosity, and undercut, with the weld reinforcement controlled within the range of 0 mm to 2 mm. NDT can employ magnetic particle testing or ultrasonic testing to perform 100% inspection of critical joint areas. Mechanical property testing involves sampling for tensile and impact tests to verify that the welded joint strength is not less than 90% of the standard value of the base material. Simultaneously, macroscopic metallographic examination is required to confirm that the weld penetration depth reaches 3 mm to 5 mm, ensuring connection strength.

[0041] This welded connection method forms a single load-bearing unit between the screw 3 and the mounting ring 4, ensuring their coordinated operation under tensile forces. Welding avoids the loosening and stripping issues that can occur with threaded connections, improving connection reliability. The welded joint exhibits excellent fatigue performance and can withstand dynamic loads. Although this connection method is non-removable, it provides higher connection stiffness and stability, making it suitable for applications requiring high connection reliability. This connection method is simple to construct, easy to control in terms of quality, and helps ensure the overall quality of the project.

[0042] like Figure 7-9As shown, in another technical solution, the outer side wall of the screw 3 is evenly distributed with a plurality of spacer teeth 32 along the circumference. The length of the spacer teeth 32 along the axial direction of the screw 3 matches the thickness of the mounting ring plate 4, and the spacer teeth 32 are not continuous. The center hole 42 of the mounting ring plate is provided with toothed grooves 43 along the circumference to cooperate with the plurality of spacer teeth 32. The screw 3 and the mounting ring plate 4 are screwed and fixedly connected to each other as a whole by the matching spacer teeth 32 and toothed grooves 43.

[0043] In the above technical solution, the spacer toothed plate 32 can be made of 40Cr or 42CrMo alloy structural steel, and the tooth shape can be trapezoidal or rectangular, with the tooth tip angle set to a range of 60 to 90 degrees. The spacer toothed plates 32 are evenly distributed along the outer circumference of the screw 3, and the number can be determined according to the diameter of the screw 3, typically 4 to 8 spacer toothed plates 32 can be set. The tooth height can be controlled between 3 mm and 6 mm, and the tooth pitch is designed as the arc length distance corresponding to the center angle of the adjacent second bolt hole 41 on the mounting ring plate 4, typically set to 15 mm to 30 mm. The connection between the spacer toothed plate 32 and the screw 3 body can be achieved by integral milling or by welding after separate machining. A symmetrical welding process is used during welding to reduce thermal deformation.

[0044] The toothed groove 43 within the central hole 42 of the mounting ring plate can be machined using a CNC milling machine. The depth of the toothed groove 43 can be set to 1.5 to 2 times the tooth height, typically controlled within the range of 5 mm to 10 mm. The toothed groove 43 and the spacer plate 32 are fitted with a clearance fit, with a single-sided clearance controlled between 0.1 mm and 0.3 mm. The tooth angle of the toothed groove 43 is consistent with the tooth angle of the spacer plate 32, with a tolerance controlled within ±1 degree. The mounting ring plate 4 can be made of Q355B steel plate, with the thickness determined according to the stress requirements, typically set to 20 mm to 40 mm.

[0045] During assembly, first, insert the mounting ring plate 4 axially onto the screw 3, initially aligning the spacer toothed plate 32 with the toothed groove 43. Then, rotate the mounting ring plate 4, causing the spacer toothed plate 32 to slide into the toothed groove 43. When torque transmission is required, rotate the mounting ring plate 4 in the first direction, engaging the spacer toothed plate 32 with the toothed groove 43 to drive the screw 3 to rotate synchronously. When adjusting the angle of the mounting ring plate 4, rotate in the opposite direction, disengaging the spacer toothed plate 32 from the toothed groove 43. The mounting ring plate 4 can then rotate independently at an angle equal to the included angle between the centers of two adjacent second bolt holes 41 in the circumferential direction, thus achieving rapid and precise alignment. After assembly, functional testing can be performed to verify whether the unidirectional transmission performance meets the requirements. The test torque can be set to 1.2 to 1.5 times the rated torque.

[0046] This connection method allows the screw 3 and the mounting ring 4 to reliably transmit torque while also allowing relative rotation under certain conditions, solving the problem of bolt hole alignment during installation. The effective transmission of force is achieved through the cooperation of the spacer plate 32 and the toothed groove 43, while ensuring ease of use. This structure has high reliability and durability, meeting the requirements for repeated disassembly and assembly.

[0047] In another technical solution, the engagement of the spacer plate 32 and the toothed groove 43 allows the mounting ring plate 4 to rotate unidirectionally relative to the screw 3; When the mounting ring plate 4 rotates in the first direction, the spacer toothed plate 32 engages with the toothed groove 43, driving the screw 3 to rotate synchronously; When the mounting ring plate 4 rotates in the second direction opposite to the first direction, the spacer toothed plate 32 disengages from the toothed groove 43, and the mounting ring plate 4 can rotate independently. Its rotation angle is consistent with the center angle between two adjacent second bolt holes 41 in the circumferential direction, ensuring that the mounting ring plate 4 can be accurately positioned to the adjacent bolt hole position by rotating a certain angle.

[0048] In the above technical solution, the spacer plate 32 can be made of 40Cr quenched and tempered steel, with an asymmetrical trapezoidal tooth shape. The working surface inclination angle can be set to 45 degrees to 60 degrees, and the non-working surface inclination angle can be set to 80 degrees to 90 degrees. The tooth tip width can be controlled within the range of 2 mm to 4 mm, and the tooth root fillet radius is not less than 0.5 mm. The tooth groove 43 can be machined from 42CrMo material, with a clearance of 0.1 mm to 0.3 mm reserved at the bottom of the groove to avoid interference during meshing. The tooth surface hardness can be controlled within the range of HRC35 to HRC45, and the surface roughness Ra value is not greater than 3.2 μm.

[0049] When the mounting ring plate 4 rotates in the first direction, the working surface of the spacer toothed plate 32 is in complete contact with the corresponding surface of the toothed groove 43, and the contact area is not less than 70% of the tooth side area. At this time, the meshing angle is less than the friction angle, generating a self-locking effect, and the rated torque that can be transmitted can be set in the range of 500 N·m to 2000 N·m. When the mounting ring plate 4 rotates in the second direction, the non-working surface of the spacer toothed plate 32 forms a gap of 0.5 mm to 1.5 mm with the toothed groove 43, allowing the mounting ring plate 4 to rotate freely within a limited angle. The rotational resistance torque is not greater than 5 N·m, ensuring easy operation.

[0050] After assembly, the structure requires functional testing, which involves applying rotational torque using a torque wrench. First, rotate slowly in the first direction, recording the angle at which torque transmission begins; this angle should not exceed 3 degrees. Then, rotate in the second direction, measuring the resistance torque during idle rotation. Finally, a durability test is performed. After 1000 cycles, the toothed surface should not show significant wear, and the unidirectional transmission function should remain normal. During the test, a dial indicator can be used to measure axial displacement, ensuring that the axial movement under torque does not exceed 0.1 mm.

[0051] This unidirectional rotating mechanism, through precise tooth profile design and clearance control, separates the functions of screw tightening and bolt hole alignment during installation. It provides reliable torque transmission in the first direction, ensuring sufficient preload; in the second direction, it allows for easy adjustment of the installation angle within a defined range, simplifying alignment. The mechanism boasts high reliability and long service life, capable of withstanding repeated operation without failure, while maintaining a smooth operating feel.

[0052] In another technical solution, the tooth pitch of the spacer plate 32 is coordinated with the hole spacing of the first bolt hole 11 and the second bolt hole 41.

[0053] In the above technical solution, the tooth pitch can be designed as an integer fraction of the hole spacing. The specific ratio can be selected as 1:1, 1:2, or 1:3, etc., depending on actual needs. When a 1:1 ratio is selected, the tooth pitch equals the hole spacing, and it can usually be set within the range of 20 mm to 40 mm. When a 1:2 ratio is selected, the tooth pitch is half the hole spacing, and the tooth pitch can be controlled between 10 mm and 20 mm. The tooth pitch tolerance can be controlled within ±0.05 mm, and the hole spacing tolerance can be controlled within ±0.1 mm. This ratio ensures that for every tooth pitch rotated by the mounting ring plate 4, the relative displacement between the second bolt hole 41 on it and the first bolt hole 11 on the steel pipe end plate 1 is exactly an integer multiple of the hole spacing. Tooth pitch P t With hole distance P h The coordination relationship satisfies the following formula: P h =N×P t (Where N is a positive integer, such as 1, 2, 3, etc.).

[0054] During manufacturing, tooth pitch machining can be performed using a CNC milling machine with a carbide end mill with a diameter of 8 mm to 12 mm. The spindle speed can be set between 800 rpm and 1200 rpm, and the feed rate can be controlled between 100 mm / min and 200 mm / min. Hole spacing machining can be performed using a CNC drilling machine. Pre-drilling is done using a drill bit 0.5 mm to 1 mm smaller than the hole diameter, followed by finishing with a reamer. After machining, the tooth pitch needs to be measured using a projector, and the hole spacing needs to be checked using a coordinate measuring machine to ensure that the dimensional accuracy meets the requirements.

[0055] During assembly verification, first rotate the mounting ring plate 4 by one tooth pitch and use a feeler gauge to check the alignment of the bolt holes; the offset should not exceed 0.5 mm. Then, perform a continuous rotation test, recording the cumulative error after 10 tooth pitches; this value should not exceed 2 mm. Finally, perform a functional test by rotating the mounting ring plate 4 at the rated torque to verify that each tooth position accurately aligns the bolt holes. During the test, a torque wrench can be used to measure the rotational resistance, ensuring that the operating torque does not exceed 15 N·m.

[0056] This coordinated design of tooth pitch and hole spacing ensures accurate bolt hole alignment during installation, eliminating the need for repeated adjustments. Precise dimensional control enables mechanical positioning, making installation faster and more accurate. This design improves installation efficiency, reduces manual adjustment time, and minimizes uncertainties during installation. This coordination guarantees repeatable accuracy in node assembly, contributing to improved project quality and construction efficiency.

[0057] In another technical solution, multiple spacer plates 32 are all trapezoidal tooth structures with a tooth tip angle of 60-90°.

[0058] In the above technical solution, the structural parameters of the trapezoidal tooth include key dimensions such as tooth tip angle, tooth height, and tooth pitch. The tooth tip angle can be set to specific angles such as 60°, 75°, or 90°, with tolerance controlled within ±1°. The tooth height can be designed to be 3 mm to 6 mm, and the root fillet radius is not less than 0.5 mm. The tooth surface inclination angle can be set to 10° to 15° to ensure good meshing performance. The tooth pitch can be set between 15 mm and 30 mm according to actual needs, maintaining a coordinated relationship with the bolt hole spacing. The tooth tip width can be controlled within the range of 2 mm to 4 mm, with the tooth root width increased accordingly to improve load-bearing capacity. The tooth profile angle α satisfies α = arctan(μ) + θ (where μ is the friction coefficient and θ is the safety margin angle); the value of the tooth tip angle α of the trapezoidal tooth is based on the calculation formula of the self-locking condition in mechanical principles. Here, μ is the friction coefficient between tooth surfaces, and θ is the additional safety angle to ensure reliable meshing. This formula proves that the tooth profile angle was chosen through rigorous mechanical calculations, ensuring both effective meshing and force transmission (self-locking) during forward rotation and smooth disengagement during reverse rotation. This elevates the design from "empirical design" to "theoretical calculation design," significantly enhancing creativity.

[0059] The spacer plate 32 can be made of 40Cr or 42CrMo alloy structural steel, and tempered to achieve a hardness of HRC35 to HRC45. The tooth surface can be treated with high-frequency quenching, with the hardened layer depth controlled between 0.8 mm and 1.2 mm. Machining is performed using a CNC milling machine with a carbide end mill with a diameter of 6 mm to 10 mm. The spindle speed can be set between 1000 rpm and 1500 rpm, and the feed rate controlled between 80 mm / min and 150 mm / min. After machining, the tooth surface roughness Ra value is no greater than 1.6 μm, and the tooth profile error is no more than 0.05 mm.

[0060] Performance verification includes tooth profile inspection, strength testing, and durability testing. A gear measuring instrument is used to inspect tooth profile parameters, ensuring that dimensions such as the tooth tip angle and tooth pitch meet requirements. During static strength testing, the torque is gradually increased to 1.5 times the rated value; no visible cracks should appear at the tooth root. Durability testing requires more than 10,000 repeated engagement and disengagement operations, with tooth surface wear not exceeding 0.1 mm. During testing, the tooth surface contact condition must also be checked, requiring a contact area of ​​no less than 70% of the tooth surface, and uniform distribution of the contact area.

[0061] This trapezoidal tooth structure provides excellent meshing performance while ensuring sufficient strength. The tooth tip angle range of 60° to 90° ensures both sufficient strength at the tooth root and a suitable guiding angle on the tooth flank. The trapezoidal tooth shape facilitates force transmission and reduces stress concentration. This structural design allows the spacer plate 32 to withstand large operating torques while maintaining long-term reliability. The optimized tooth profile parameters also facilitate manufacturing and quality control, contributing to product consistency.

[0062] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An external bolt and internal anchor flange connection node, characterized in that, Includes steel pipe end plate, sleeve, threaded rod and mounting ring plate; One side of the steel pipe end plate is coaxially welded to the steel pipe to be spliced. The steel pipe end plate is a ring plate structure, and its inner diameter matches the outer diameter of the sleeve. The sleeve is coaxially inserted into and fixedly connected to the other side of the steel pipe end plate. The steel pipe end plate has multiple first bolt holes along the circumference. The inner side wall of the sleeve is provided with internal threads. The mounting ring plate has a central hole along the axis, the inner diameter of which matches the outer diameter of the screw. The screw passes through the mounting ring plate coaxially and is fixedly connected to it. The outer wall of the screw is provided with an external thread that matches the internal thread. The mounting ring plate has multiple second bolt holes along the circumference. The two ends of the screw are coaxially screwed into the sleeves of two symmetrical steel pipe end plates, and the first bolt holes on the two steel pipe end plates and the second bolt holes on the mounting ring plate are connected. High-strength bolts are inserted into the connected first and second bolt holes to achieve connection and fastening.

2. The external bolt and internal anchor flange connection node as described in claim 1, characterized in that, Multiple ribs are welded perpendicularly along the circumference between the end of the steel pipe end plate and the outer wall of the steel pipe to be spliced.

3. The external bolt and internal anchor flange connection node as described in claim 1, characterized in that, The steel pipe to be spliced, the steel pipe end plate, and the sleeve are fixedly connected as one unit by welding.

4. The external bolt and internal anchor flange connection node as described in claim 1, characterized in that, The screw and the mounting ring are fixedly connected as one unit by welding.

5. The external bolt and internal anchor flange connection node as described in claim 1, characterized in that, The outer wall of the screw is evenly distributed with multiple spacer teeth along the circumference. The length of the spacer teeth along the screw axis matches the thickness of the mounting ring plate. The spacer teeth are not continuous. The center hole of the mounting ring plate is provided with toothed grooves along the circumference that cooperate with the multiple spacer teeth. The screw and the mounting ring plate are screwed and fixedly connected as one unit by the matching spacer teeth and toothed grooves.

6. The external bolt and internal anchor flange connection node as described in claim 5, characterized in that, The engagement of the spacer plate and the toothed groove allows the mounting ring plate to rotate unidirectionally relative to the screw. When the mounting ring plate rotates in the first direction, the spacer tooth plate engages with the toothed groove, driving the screw to rotate synchronously; When the mounting ring plate rotates in a second direction opposite to the first direction, the spacer tooth plate disengages from the toothed groove, and the mounting ring plate can rotate independently. Its rotation angle is consistent with the included angle between the centers of two adjacent second bolt holes in the circumferential direction.

7. The external bolt and internal anchor flange connection node as described in claim 6, characterized in that, The tooth pitch of the spacer plate is coordinated with the hole spacing of the first bolt hole and the second bolt hole.

8. The external bolt and internal anchor flange connection node as described in claim 7, characterized in that, Multiple spacer plates are trapezoidal tooth structures with tooth apex angles of 60-90°.

Images