Anti-loose flange connecting joint for iron tower and manufacturing and mounting method

Abstract

The invention relates to the technical field of iron tower installation, and discloses an anti-loose flange connecting joint for an iron tower and a manufacturing and installing method.The anti-loose flange connecting joint for the iron tower comprises an upper segment circular steel pipe and a lower segment circular steel pipe, and the outer ring of the upper segment circular steel pipe is fixedly connected with an upper flange plate; the upper flange plate is fixedly connected with a balance rib plate fixedly connected with the upper segment round steel pipe, the outer ring of the end of the lower segment round steel pipe is fixedly connected with a lower flange plate, the bottom of the lower flange plate is fixedly connected with an inclined strut fixedly connected with the lower segment round steel pipe, and a bolt is connected between the upper flange plate and the lower flange plate. According to the invention, the connection tensile bearing capacity of the iron tower flange is improved, the elastic deformation after the bolt is tensioned is increased, and the secondary bending moment borne by the bolt is reduced, so that the plastic deformation and fretting wear of the thread are reduced, the bolt pretightening force between the upper flange and the lower flange is kept at a higher level, the maintenance cost of the iron tower is reduced, and the safety of the node is improved; the device is convenient to manufacture, low in manufacturing cost, convenient to install and high in practicability.

Description

Technical Field

[0001] The invention relates to the technical field of iron tower installation, and in particular to an anti-loosening flange connection node for an iron tower and a manufacturing and installation method thereof. Background Art

[0002] In the field of steel towers, the existing single-tube towers and steel tube truss towers are mostly connected by flanges (with stiffening rib flanges). During use, due to the lack of effective maintenance for a long time, a considerable number of flange bolts have loose nuts and fallen off. While the fastening of nodes depends on manual work, if there is a lack of effective supervision, there will be major safety hazards.

[0003] The bolts that are loose mainly include the inner flange bolts of the single-tube tower, the outer flange bolts of the single-tube tower, the tower column of the steel tube truss tower and the flange bolts of the diagonal rod. The severity is mainly affected by the flange processing accuracy, the initial preload of the bolts, and the wind conditions (including wind speed and turbulence) at the location. But in essence, under the action of wind load, the flange bolts are subjected to reciprocating tension and compression alternating loads, the preload gradually decays and the nut rotates. Therefore, a flange connection node for iron towers and a manufacturing and installation method are proposed. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides an anti-loosening flange connection node for an iron tower and a manufacturing and installation method.

[0005] The present invention is implemented by the following technical scheme: an anti-loosening flange connection node for an iron tower, comprising an upper segmented circular steel pipe and a lower segmented circular steel pipe, the upper segmented circular steel pipe having an outer ring fixedly connected to an upper flange plate, the upper flange plate having a balancing stiffener fixedly connected to the upper segmented circular steel pipe, the end outer ring of the lower segmented circular steel pipe having a lower flange plate fixedly connected, the bottom of the lower flange plate having a diagonal brace fixedly connected to the lower segmented circular steel pipe, and bolts connecting the upper flange plate and the lower flange plate.

[0006] As a further improvement of the above scheme, a notch 1 is provided at the top of the balancing stiffener close to the upper segmented circular steel pipe, and a notch 2 is provided at the bottom of the balancing stiffener close to the upper segmented circular steel pipe. The notch 2 abuts against the top of the lower flange plate during installation.

[0007] As a further improvement of the above scheme, a weld 1 is provided on the top and side of the balancing stiffener, and the balancing stiffener is fixedly connected to the upper segmented circular steel pipe and the upper flange plate through the weld 1. The balancing stiffener is distributed in an array along the axis of the upper flange plate, and the balancing stiffener is located on the diameter extension line of the upper flange plate.

[0008] As a further improvement of the above solution, the top and bottom outer rings of the upper flange plate are provided with weld seams 2 connected to the upper segmented circular steel pipe.

[0009] As a further improvement of the above scheme, the top and bottom outer circles of the lower flange plate are provided with weld three connected to the lower segmented circular steel pipe, and the weld three at the top of the flange plate is polished and trimmed to be flush with the top of the lower segmented circular steel pipe, and the top and bottom of the lower flange plate are flush with the top of the lower segmented circular steel pipe.

[0010] As a further improvement of the above scheme, the top and side of the diagonal brace are provided with weld four, and the diagonal brace is connected to the lower segmented round steel pipe and the lower flange plate through weld four. The diagonal brace is distributed in an array along the axis of the lower flange plate, and the diagonal brace is located on the diameter extension line of the lower flange plate.

[0011] As a further improvement of the above solution, the balancing stiffener is located directly above the diagonal brace, and the balancing stiffener and the bolts are arranged alternately.

[0012] As a further improvement of the above solution, one end of the bolt passing through the upper flange plate is connected with a washer and a nut for tightening, and the ratio of the bolt clamping distance to the bolt diameter is greater than.

[0013] A method for manufacturing an anti-loosening flange connection node for an iron tower comprises the following steps:

[0014] Step S1, preparing an upper segmented circular steel pipe, an upper flange plate, a balancing stiffener, a lower flange plate, a lower segmented circular steel pipe and a diagonal brace according to design requirements;

[0015] Step S2, welding the upper flange plate and the balance stiffener to the upper segmented round steel pipe, and welding the lower flange plate and the diagonal brace to the lower segmented round steel pipe;

[0016] Step S3, using a milling machine to mill the bottom of the balance stiffener and the bottom of the upper segmented circular steel pipe, and mill the lower flange plate and the top of the lower segmented circular steel pipe.

[0017] A method for installing a tower anti-loosening flange connection node comprises the following steps:

[0018] Step S11, transporting the processed parts and bolts to the installation site;

[0019] Step S12, use the lifting equipment to lift the upper segmented circular steel pipe to the top of the lower segmented circular steel pipe, and complete the docking operation of the lower flange plate and the upper flange plate, and then use bolts and gasket nuts to tighten and install. The bolts are constructed using the direct tensioning method, and each bolt is tensioned for at least two rounds. The loss of bolt preload during the tensioning stage needs to be calibrated through testing to ensure the stability of the initial preload of the bolt.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention arranges a balancing stiffener between the flange plate of the upper flange and the flange plate of the lower flange, and then connects the upper flange and the lower flange by bolts. The balancing stiffener lengthens the free length of the bolt (the ratio of the free length to the diameter is greater than 8), and increases the elastic deformation of the bolt after tensioning, so that when the thread of the bolt has slight plastic deformation and fretting wear during the operation stage, the influence on the preload force is small. At the same time, due to the lengthening of the free length of the bolt, the bolt line stiffness is reduced, the tensile bearing capacity of the tower flange connection is improved, the elastic deformation of the bolt after tensioning is increased, and the secondary bending moment of the bolt is reduced, thereby reducing the plastic deformation and fretting wear of the thread, so that the bolt preload force between the upper flange and the lower flange is maintained at a high level, and the maintenance cost of the tower is reduced;

[0022] 2. The present invention adopts direct tensioning method to install bolts. After installation, there is no residual torque in the bolts, which avoids the residual torque in the bolts under the tension-compression alternating state causing the nut to rotate, eliminates the internal cause of the nut rotation, keeps the nut tight, and improves the safety of the node;

[0023] 3. The present invention adopts direct tensioning method to install bolts. After installation, there is no residual torque in the bolts, and the bolt stress state is simple, which is conducive to improving the tensile ultimate bearing capacity and improving the node safety redundancy;

[0024] 4. The present invention adopts direct tensioning method to install bolts, and the pre-tightening force is almost not affected by the torque coefficient. The initial pre-tightening force of the bolt after installation is large and stable, the bolt force amplitude changes little, it is not easy to loosen and has a long service life;

[0025] 5. The present invention adopts a welded stiffening flange as the lower flange. The contact surface area of ​​the lower plate is large, and the contact surface is flattened by milling. Even if there is a small positioning error between the balancing stiffening plate and the diagonal brace 13 in the axial direction, it does not affect the transmission of the bolt preload force, and hardly affects the force of the connection node, which reduces the requirements for the welding accuracy of the upper flange, is convenient to manufacture, and has a low cost.

[0026] 6. In the present invention, all the work that needs to control quality and precision is completed in the factory, and only the bolts need to be tensioned on site, which is convenient for installation and has high feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the assembly diagram of the connected nodes;

[0028] Figure 2 The exploded structure diagram for the connection nodes;

[0029] Figure 3 It is a schematic diagram of the structure after the upper segmented round steel pipe is welded;

[0030] Figure 4 This is a schematic diagram of the structure after the lower segment circular steel pipe is welded.

[0031] Description of main symbols:

[0032] 1. Upper segmented circular steel pipe; 2. Upper flange plate; 3. Balance stiffener; 4. Lower flange plate; 5. Lower segmented circular steel pipe; 6. Bolts; 7. Weld 2; 8. Weld 3; 9. Weld 1; 10. Weld 4; 11. Notch 1; 12. Notch 2; 13. Diagonal brace. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0034] Embodiment 1:

[0035] Please combine Figure 1-Figure 4 The present embodiment provides an anti-loosening flange connection node for an iron tower, comprising an upper segmented circular steel pipe 1 and a lower segmented circular steel pipe 5, wherein the upper segmented circular steel pipe 1 is fixedly connected to an upper flange plate 2 on its outer ring, the upper flange plate 2 is fixedly connected to a balancing stiffener 3 fixed to the upper segmented circular steel pipe 1, the end outer ring of the lower segmented circular steel pipe 5 is fixedly connected to a lower flange plate 4, the bottom of the lower flange plate 4 is fixedly connected to a diagonal brace 13 fixed to the lower segmented circular steel pipe 5, and bolts 6 are connected between the upper flange plate 2 and the lower flange plate 4.

[0036] A notch 11 is provided at the top of the balancing plate 3 close to the upper segmented circular steel pipe 1 , and a notch 2 12 is provided at the bottom of the balancing plate 3 close to the upper segmented circular steel pipe 1 . The notch 2 12 abuts against the top of the lower flange plate 4 during installation.

[0037] The top and side of the balancing stiffener 3 are both provided with welds 9, and the balancing stiffener 3 is fixedly connected to the upper segmented round steel pipe 1 and the upper flange plate 2 through the welds 9. The balancing stiffener 3 is distributed in an array along the axis of the upper flange plate 2, and the balancing stiffener 3 is located on the diameter extension line of the upper flange plate 2.

[0038] The top and bottom outer rings of the upper flange plate 2 are provided with weld seams 7 connected to the upper segmented round steel pipe 1 .

[0039] The top and bottom outer circles of the lower flange plate 4 are provided with weld seams 8 connected to the lower segmented circular steel pipe 5, and the weld seams 8 at the top of the flange plate 4 are polished and trimmed to be flush with the top of the lower segmented circular steel pipe 5, and the top and bottom of the lower flange plate 4 are flush with the top of the lower segmented circular steel pipe 5.

[0040] The top and side of the diagonal brace 13 are provided with weld seams 10, and the diagonal brace 13 is connected to the lower segmented round steel pipe 5 and the lower flange plate 4 through the weld seams 10. The diagonal brace 13 is distributed in an array along the axis of the lower flange plate 4, and the diagonal brace 13 is located on the diameter extension line of the lower flange plate 4.

[0041] The balancing stiffener 3 is located directly above the diagonal brace 13 , and the balancing stiffener 3 and the bolts 6 are alternately arranged.

[0042] One end of the bolt 6 passing through the upper flange plate 2 is connected with a washer and a nut for tightening, wherein the balancing stiffener 3 is rectangular, and the height of the balancing stiffener 3 is designed based on the ratio of the clamping distance of the bolt 6 to the bolt diameter being greater than 8, thereby increasing the elastic deformation and strain energy of the bolt 6 and reducing the loss of the bolt preload force of the bolt 6 during the tensioning stage and the use stage.

[0043] Weld 1 9, weld 2 7, weld 3 8, weld 4 10 are any one of the T-shaped connection welds or fillet welds.

[0044] The implementation principle of an anti-loosening flange connection node for an iron tower in the embodiment of the present application is as follows: the pre-tightening force of the bolt 6 is converted into a tightening force between the upper segmented circular steel pipe 1 and the lower segmented circular steel pipe 5, the balancing stiffening plate 3 and the diagonal brace 13 through the lower flange plate 4. The force transmission path is clear and the force transmission is efficient. When the pre-tightening force of the bolt is accurate, it is ensured that the flange contact surface is not disengaged under normal use conditions, the bolt force amplitude changes little, and it is not easy to loosen; the balancing stiffening plate 3 is provided with a notch 11 and a notch 2 12 near the upper flange plate 2 and the upper segmented circular steel pipe 1 to facilitate the passage of the weld 2 7 and avoid the intersection of the weld 2 7 with the weld 1 9. The balancing stiffening plate 3 is provided with a notch 2 12 on the contact surface with the lower flange plate 4, so that the upper flange and the lower flange are in point contact in each bolt sector, which is easier to tighten each other, ensuring a good flange contact state, so that the actual force condition of the connection node maintains a high degree of consistency with the calculation model.

[0045] Embodiment 2:

[0046] A method for manufacturing an anti-loosening flange connection node for an iron tower comprises the following steps:

[0047] Step S1, preparing an upper segmented circular steel pipe 1, an upper flange plate 2, a balancing stiffener 3, a lower flange plate 4, a lower segmented circular steel pipe 5 and a diagonal brace 13 according to design requirements;

[0048] Step S2, welding the upper flange plate 2 and the balance stiffener 3 to the upper segmented round steel pipe 1, and welding the lower flange plate 4 and the diagonal brace 13 to the lower segmented round steel pipe 5;

[0049] Step S3, using a milling machine to mill the bottom of the balance stiffener 3 and the bottom of the upper segmented circular steel pipe 1, and mill the lower flange plate 4 and the top of the lower segmented circular steel pipe 5.

[0050] Embodiment 3:

[0051] A method for installing a tower anti-loosening flange connection node comprises the following steps:

[0052] Step S11, transporting the processed parts and bolts 6 to the installation site;

[0053] Step S12, use the lifting equipment to lift the upper segmented circular steel pipe 1 to the top of the lower segmented circular steel pipe 5, and complete the docking operation of the lower flange plate 4 and the upper flange plate 2, and then use the bolts 6 and gasket nuts to tighten and install. The bolts 6 are constructed using the direct tensioning method. Each bolt 6 is tensioned for at least two rounds. The preload loss of the bolt 6 during the tensioning stage needs to be calibrated through experiments to ensure the stability of the initial preload of the bolt.

[0054] The present invention arranges a balancing stiffener between the flange plate of the upper flange and the flange plate of the lower flange, and then connects the upper flange and the lower flange by bolts. The balancing stiffener lengthens the free length of the bolt (the ratio of the free length to the diameter is greater than 8), and increases the elastic deformation of the bolt after tensioning, so that when the thread of the bolt has slight plastic deformation and micro-wear during the operation stage, the influence on the preload force is small. At the same time, due to the lengthening of the free length of the bolt, the tensile bearing capacity of the tower flange connection is improved, the elastic deformation of the bolt after tensioning is increased, and the bolt line stiffness is reduced, and the secondary bending moment of the bolt is reduced, thereby reducing the plastic deformation and micro-wear of the thread, so that the bolt preload force between the upper flange and the lower flange is maintained at a high level, and the maintenance cost of the tower is reduced;

[0055] The bolts are installed by direct tensioning method. After installation, there is no residual torque in the bolts, which avoids the residual torque in the bolts under the tension-compression alternating state causing the nut to rotate. The internal cause of the nut rotation is eliminated, so that the nut remains tight and the safety of the node is improved.

[0056] The direct tensioning method is used to install bolts. After installation, there is no residual torque in the bolts, and the bolt stress state is simple, which is conducive to improving the ultimate tensile bearing capacity and improving the safety redundancy of the node;

[0057] The bolts are installed by direct tensioning method, and the preload force is almost unaffected by the torque coefficient. The initial preload force of the bolts after installation is large and stable, the bolt force amplitude changes little, it is not easy to loosen and has a long service life;

[0058] The welded stiffening flange is used as the lower flange. The contact surface area of ​​the lower plate is larger, and the contact surface is flattened by milling. Even if there is a small positioning error between the balancing stiffening plate and the diagonal brace 13 in the axial direction, it does not affect the transmission of the bolt preload force, and hardly affects the force of the connection node, which reduces the requirements for the welding accuracy of the upper flange, is convenient to manufacture, and has a low cost.

[0059] All work that requires quality and precision control is completed in the factory, and only the bolts need to be tensioned on site. The installation is convenient and has high feasibility.

[0060] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A tower anti-loosening flange connection node, characterized in that: It includes an upper segmented circular steel pipe and a lower segmented circular steel pipe. The upper segmented circular steel pipe is fixedly connected to an upper flange plate on its outer ring, and the upper flange plate is fixedly connected to a balancing stiffener fixed to the upper segmented circular steel pipe. The end outer ring of the lower segmented circular steel pipe is fixedly connected to a lower flange plate, and the bottom of the lower flange plate is fixedly connected to a diagonal brace fixed to the lower segmented circular steel pipe. Bolts are connected between the upper flange plate and the lower flange plate.

2. The anti-loosening flange connection node for an iron tower as claimed in claim 1, characterized in that: The balance stiffener is provided with a first notch at the top of one side close to the upper segmented circular steel pipe, and a second notch is provided at the bottom of one side close to the upper segmented circular steel pipe. The second notch contacts the top of the lower flange plate during installation.

3. The anti-loosening flange connection node for an iron tower as claimed in claim 1, characterized in that: The top and side of the balancing stiffener are both provided with weld seams 1, and the balancing stiffener is fixedly connected to the upper segmented round steel pipe and the upper flange plate through weld seams 1. The balancing stiffener is distributed in an array along the axis of the upper flange plate, and the balancing stiffener is located on the diameter extension line of the upper flange plate.

4. The anti-loosening flange connection node for an iron tower as claimed in claim 1, characterized in that: The top and bottom outer rings of the upper flange plate are provided with weld seams 2 connected to the upper segmented circular steel pipe.

5. The anti-loosening flange connection node for an iron tower as claimed in claim 1, characterized in that: The top and bottom outer rings of the lower flange plate are provided with weld seams three connected to the lower segmented circular steel pipe, and the weld seams three at the top of the flange plate are polished and trimmed to be flush with the top of the lower segmented circular steel pipe, and the top and bottom of the lower flange plate are flush with the top of the lower segmented circular steel pipe.

6. The anti-loosening flange connection node for an iron tower as claimed in claim 1, characterized in that: The top and side of the diagonal brace are both provided with weld seams 4, and the diagonal brace is connected to the lower segmented round steel pipe and the lower flange plate through the weld seams 4. The diagonal brace is distributed in an array along the axis of the lower flange plate, and the diagonal brace is located on the diameter extension line of the lower flange plate.

7. The anti-loosening flange connection node for an iron tower as claimed in claim 1, characterized in that: The balancing stiffener is located directly above the diagonal brace, and the balancing stiffener and the bolts are arranged alternately.

8. The anti-loosening flange connection node for an iron tower as claimed in claim 1, characterized in that: One end of the bolt passing through the upper flange plate is connected with a washer and a nut for tightening, and the ratio of the bolt clamping distance to the bolt diameter is greater than.

9. A method for manufacturing a tower anti-loosening flange connection node according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S1, preparing an upper segmented circular steel pipe, an upper flange plate, a balancing stiffener, a lower flange plate, a lower segmented circular steel pipe and a diagonal brace according to design requirements; Step S2, welding the upper flange plate and the balance stiffener to the upper segmented round steel pipe, and welding the lower flange plate and the diagonal brace to the lower segmented round steel pipe; Step S3, using a milling machine to mill the bottom of the balance stiffener and the bottom of the upper segmented circular steel pipe, and mill the lower flange plate and the top of the lower segmented circular steel pipe.

10. A method for installing a tower anti-loosening flange connection node according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S11, transporting the processed parts and bolts to the installation site; Step S12, use the lifting equipment to lift the upper segmented circular steel pipe to the top of the lower segmented circular steel pipe, and complete the docking operation of the lower flange plate and the upper flange plate, and then use bolts and gasket nuts to tighten and install. The bolts are constructed using the direct tensioning method, and each bolt is tensioned for at least two rounds. The loss of bolt preload during the tensioning stage needs to be calibrated through testing to ensure the stability of the initial preload of the bolt.

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