A steel tube angle steel combined joint of a power transmission tower

Abstract

The utility model provides a kind of power transmission tower steel pipe angle steel combined node, including node steel pipe, two key protrusions are welded on the node steel pipe correspondingly, key protrusion is matched with the keyway of node sleeve hoop, the clamping plate being set on two node sleeve hoops is fixedly installed together by mounting bolt, vertical node plate and horizontal node plate are integrally arranged on the outer surface of each node sleeve hoop, and angle steel hole is arranged on vertical node plate and horizontal node plate;The utility model passes through the force transmission of the engagement of the key protrusion of the shape of the letter 'ten' and keyway, avoids friction failure;Radial zygomatic installation, without welding on site, improve construction efficiency;Integral node plate enhances rigidity, forms rigid whole, improves bearing capacity.

Description

Technical Field

[0001] This utility model belongs to the technical field of angle steel nodes, and particularly relates to a steel pipe angle steel combined node for transmission towers. Background Technology

[0002] In power transmission line engineering, transmission towers, as key structures supporting conductors, directly affect the safety and durability of the overall structure due to the reliability of their node connections. The combined joints of steel pipes and angle steel are the core components of the transmission tower, enabling the transfer of mechanical strength between different parts, and must simultaneously meet requirements for load-bearing capacity, ease of installation, and adaptability to maintenance.

[0003] Existing steel pipe angle steel nodes for transmission towers mainly employ two connection methods: First, on-site welding, where the node plate is directly welded to the steel pipe surface for fixation. However, this method has significant drawbacks. For example, welding quality during field construction is greatly affected by the environment (wind, rain, low temperatures), easily leading to defects such as porosity and cracks. Furthermore, welding relies on a stable power supply, making it difficult to implement in remote mountainous areas with limited construction conditions, and subsequent disassembly and replacement are extremely inconvenient. Second, integral sleeve bolt connection, where an integral sleeve is fitted over the steel pipe and then tightened with bolts. While this structure avoids on-site welding, the sleeve is often an integral design, requiring insertion from the end of the steel pipe, which severely restricts the transportation and installation sequence of components. Moreover, the load is transferred between the sleeve and the steel pipe solely through bolt friction, making them prone to relative slippage due to insufficient preload, affecting node stability.

[0004] Therefore, it is essential to invent a steel pipe angle steel combination node for transmission towers. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a steel pipe and angle steel combined node for transmission towers, including a node steel pipe, key protrusions, node sleeves, keyways, clamping plates, mounting bolts, vertical node plates, horizontal node plates, and angle steel holes. Two key protrusions are welded to the node steel pipe, and the key protrusions cooperate with the keyways of the node sleeves. The clamping plates provided on the two node sleeves are tightly fixed together by mounting bolts. The vertical node plate and the horizontal node plate are integrally provided on the outer surface of each node sleeve, and angle steel holes are provided on the vertical node plate and the horizontal node plate.

[0006] Preferably, the two key protrusions welded to the outer surface of the node steel pipe are cross-shaped structures, which are formed by the intersection of vertical and horizontal parts, and each key protrusion is engaged with the keyway of the corresponding node sleeve.

[0007] Preferably, the node sleeve has a semi-circular structure, the keyway is provided on the inner surface, and the keyway is also in the shape of a cross. Each node sleeve has a clamping plate welded to both ends, and a total of four clamping plates are provided.

[0008] Preferably, each of the clamping plates of the node sleeve has a through hole, and the corresponding clamping plates are installed together by mounting bolts.

[0009] Preferably, the vertical node plate and the horizontal node plate integrally formed on the outer surface of the node sleeve together constitute a "+" shaped node structure, and the two are intersected with each other.

[0010] Preferably, the vertical node plate and the horizontal node plate are provided with angle steel holes corresponding to the angle steels, and the angle steel holes are not provided around the intersection of the vertical node plate and the horizontal node plate.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes the interlocking of a cross-shaped key protrusion on the node steel pipe and a cross-shaped keyway on the node sleeve to form a mechanical interlocking constraint. This effectively restricts circumferential rotation and radial sliding between the node sleeve and the steel pipe, ensuring that loads (especially torque and lateral force) are directly transmitted through the key protrusion, avoiding the interruption of force transmission caused by friction failure in traditional bolt connections. Simultaneously, the connection between the cross-shaped node plate (vertical + lateral) and the angle steel is precisely positioned through the angle steel holes, allowing the angle steel load to be directly transmitted along the node plate to the sleeve and steel pipe. This clear force transmission path reduces stress concentration.

[0012] This utility model eliminates the need to insert the steel pipe from the end; it can be directly installed by radial alignment, significantly reducing the requirements for construction space and component installation sequence. The two sleeves are fastened to the installation bolts by clamping plates, eliminating the need for on-site welding throughout the process. Assembly can be completed with just bolt operation, solving the problems of difficult access to electricity and difficulty in ensuring welding quality in remote areas, and significantly improving on-site construction efficiency.

[0013] This utility model integrates the node sleeve with the vertical and horizontal node plates, avoiding the weak points in the connection of traditional welded node plates and improving the overall rigidity of the node. The full contact fit between the "+" shaped key protrusion and the keyway, combined with the preload generated by the bolt clamping, makes the node sleeve and the steel pipe form a rigid whole, which can effectively resist the deformation of the transmission tower under wind load and seismic load, and improve the ultimate bearing capacity of the node. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is an exploded structural diagram of the present invention.

[0016] In the picture: Node steel pipe 1, key protrusion 2, node sleeve 3, keyway 4, clamping plate 5, mounting bolt 6, vertical node plate 7, horizontal node plate 8, angle steel hole 9. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0018] In the description of the embodiments, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present utility model based on the specific circumstances.

[0019] As attached Figure 1 To be continued Figure 2 As shown: This utility model provides a steel pipe and angle steel combined node for a transmission tower, comprising a node steel pipe 1, key protrusions 2, node sleeves 3, keyways 4, clamping plates 5, mounting bolts 6, vertical node plates 7, horizontal node plates 8, and angle steel holes 9. Two key protrusions 2 are welded to the node steel pipe 1, and the key protrusions 2 cooperate with the keyways 4 of the node sleeves 3. The clamping plates 5 provided on the two node sleeves 3 are tightly fixed together by the mounting bolts 6. The vertical node plates 7 and horizontal node plates 8 are integrally provided on the outer surface of each node sleeve 3, and angle steel holes 9 are provided on the vertical node plates 7 and horizontal node plates 8.

[0020] Furthermore, two symmetrical cross-shaped key protrusions 2 are welded radially to the outer surface of the node steel pipe 1. These key protrusions 2 are made of Q345B high-strength steel plate, with their vertical and horizontal sections intersecting at 90° angles. The center of the intersection is collinear with the axis of the node steel pipe 1, and their overall height matches the wall thickness of the node sleeve 3. The connection between the key protrusions 2 and the node steel pipe 1 uses double-sided fillet welds, and the welds undergo visual inspection and ultrasonic testing to ensure there are no defects such as incomplete penetration or porosity. The vertical and horizontal sections of each key protrusion 2 form a clearance fit with the corresponding cross-shaped keyway 4 on the inner side of the node sleeve 3 (the fit clearance is controlled within 0.5-1mm). This mechanical interlocking structure restricts the circumferential rotation and radial sliding of the node sleeve 3 relative to the node steel pipe 1, providing a basic constraint for load transfer.

[0021] Furthermore, the node sleeve 3 is made of Q345B steel plate that matches the material of the node steel pipe 1. It is semi-circular in shape, and its inner arc radius is consistent with the outer radius of the node steel pipe 1. The inner surface of the node sleeve 3 is milled with a cross-shaped keyway 4 by a CNC machine tool. The width and depth of the keyway 4 are adapted to the cross-sectional dimensions of the key protrusion 2 (the depth is 0.5mm larger than the height of the key protrusion 2, and the width is 1mm larger than the width of the key protrusion 2), ensuring that the key protrusion 2 can be smoothly embedded. Each node sleeve 3 has a clamping plate 5 vertically welded to both ends. The clamping plate 5 is a rectangular Q345B steel plate, and four are symmetrically arranged. The connection between the clamping plate 5 and the node sleeve 3 adopts a full-circumference continuous fillet weld. The weld height is not less than the plate thickness of the clamping plate 5. After welding, the surface of the clamping plate 5 needs to be ground to ensure its flatness to accommodate the bolt connection.

[0022] Furthermore, each node sleeve 3 has 2-4 through holes symmetrically drilled vertically on the clamping plates 5 at both ends. The through holes are CNC drilled and the hole diameter is designed according to the specifications of the mounting bolts 6. After the two semi-circular node sleeves 3 are aligned with the node steel pipe 1, the corresponding clamping plates 5 on both sides (two sets in total, two in each set) are fastened together by the mounting bolts 6. The mounting bolts 6 are high-strength large hexagonal head bolts with a performance grade of 10.9, and are equipped with high-strength nuts and spring washers. During installation, a torque wrench is used to tighten them to the designed preload. The preload of the bolts makes the two node sleeves 3 fit tightly against the node steel pipe 1, forming a double constraint of "positioning + fastening" with the cooperation of the key protrusion 2-keyway 4.

[0023] Furthermore, the outer surface of the node sleeve 3 is integrally provided with a vertical node plate 7 and a horizontal node plate 8 along the axial direction. Both are made of Q345B steel plate and are integral structures of the same material as the node sleeve 3 (they are welded together with the sleeve after forging or CNC cutting, and the welding adopts a section weld to ensure the connection strength). The vertical node plate 7 and the horizontal node plate 8 intersect at 90° perpendicularly, and the center of the intersection is collinear with the axis of the node sleeve 3, forming a "+" shaped node plate structure. The width (e.g., 120mm) and thickness (e.g., 12mm) of the node plate are designed according to the specifications of the connecting angle steel and the load requirements. The length of the vertical node plate 7 extends along the axial direction of the node steel pipe 1, and the length of the horizontal node plate 8 extends along the radial direction. The edges of both are chamfered (chamfer radius 5mm) to reduce stress concentration.

[0024] Furthermore, both the vertical node plates 7 and the horizontal node plates 8 have through-holes 9 along their length. The diameter of the angle steel holes 9 matches the diameter of the bolt holes connecting the angle steel, and the hole spacing is designed according to the steel structure bolt arrangement specifications. A punching process is used to ensure smooth hole walls. To avoid weakening the core load-bearing area at the intersection of the node plates, angle steel holes 9 are not provided within 50mm of the intersection center of the vertical node plate 7 and the horizontal node plate 8, ensuring the structural integrity and rigidity of this area. The number of angle steel holes 9 is designed according to the connection length of the angle steel (usually 2-3 holes per side), and the hole position error is controlled within ±0.5mm to achieve precise connection with the angle steel and bolt tightening.

[0025] The working principle is as follows: First, the node steel pipe 1, as the core load-bearing component of the transmission tower, has a key protrusion 2 pre-welded to its outer surface, providing a precise positioning reference for subsequent node assembly and establishing an initial mechanical interface for load transfer. Second, the two semi-circular node sleeves 3 cooperate with the key protrusion 2 on the node steel pipe 1 through the keyway 4 on their inner sides. By utilizing the mechanical interlocking relationship between the key protrusion 2 and the keyway 4, the circumferential rotation and radial sliding of the node sleeves 3 relative to the node steel pipe 1 are directly restricted, achieving initial positioning and force transmission constraint between the two.

[0026] Secondly, after the two node sleeves 3 are aligned, the clamping plates 5 at both ends fit together, and the pre-tightening force generated by the tightening action of the mounting bolts 6 tightly presses the node sleeves 3 onto the surface of the node steel pipe 1. This, together with the key protrusion 2 and keyway 4, forms a dual constraint of "positioning + tightening," making the node sleeves 3 and the node steel pipe 1 a rigid whole. Then, the vertical node plate 7 and the horizontal node plate 8 integrally set on the outer surface of the node sleeves 3 form a "+" shaped connection structure. The angle steel holes 9 on their surfaces provide connection interfaces for the angle steel components of the transmission tower, and the angle steel can be firmly connected to the node plate by bolts.

[0027] Finally, when the angle steel is subjected to external loads such as wind and icing, the load is first transferred to the vertical node plate 7 and the horizontal node plate 8, then transferred to the key protrusion 2 through the node sleeve 3, and finally the key protrusion 2 transmits the load to the node steel pipe 1, completing the entire load transfer process of the node and ensuring the stability of the transmission tower structure.

[0028] Any technical solution that achieves the above-mentioned technical effects by utilizing the technical solution described in this utility model, or by designing a similar technical solution inspired by the technical solution described in this utility model, falls within the protection scope of this utility model.

Claims

1. A steel pipe and angle steel composite node for a transmission tower, characterized in that, The system includes a node steel pipe (1), a key protrusion (2), a node sleeve (3), a keyway (4), a clamping plate (5), mounting bolts (6), a vertical node plate (7), a horizontal node plate (8), and angle steel holes (9). Two key protrusions (2) are welded to the node steel pipe (1). The key protrusions (2) cooperate with the keyway (4) of the node sleeve (3). The clamping plates (5) on the two node sleeves (3) are tightly fixed together by mounting bolts (6). The vertical node plate (7) and the horizontal node plate (8) are integrally provided on the outer surface of each node sleeve (3). Angle steel holes (9) are provided on the vertical node plate (7) and the horizontal node plate (8).

2. The transmission tower steel pipe angle steel composite node as described in claim 1, characterized in that: The two key protrusions (2) welded to the outer surface of the node steel pipe (1) are in the shape of a cross, which is composed of a vertical part and a horizontal part. Each key protrusion (2) is matched with the keyway (4) of the corresponding node sleeve (3).

3. The transmission tower steel pipe angle steel composite node as described in claim 2, characterized in that: The node sleeve (3) has a semi-circular structure, and the keyway (4) is set on the inner surface. The keyway (4) is also in the shape of a cross. The clamping plate (5) is welded to both ends of each node sleeve (3). There are four clamping plates (5) in total.

4. A transmission tower steel pipe angle steel composite node as described in claim 3, characterized in that: Each of the node sleeves (3) has a through hole on its clamping plate (5), and the corresponding clamping plates (5) are installed together by mounting bolts (6).

5. A transmission tower steel pipe angle steel composite node as described in claim 4, characterized in that: The vertical node plate (7) and the horizontal node plate (8) integrally set on the outer surface of the node sleeve (3) together form a "+" shaped node structure, and the two are intersected with each other.

6. A steel pipe angle steel composite node for a transmission tower as described in claim 5, characterized in that: The vertical node plate (7) and the horizontal node plate (8) are provided with angle steel holes (9) corresponding to the angle steels, but the angle steel holes (9) are not provided around the intersection of the vertical node plate (7) and the horizontal node plate (8).

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