A prestressed construction tensioning head

Abstract

This utility model relates to the field of prestressed engineering technology, specifically disclosing a prestressed strand threading traction head for prestressed construction. It includes a traction bolt connected to the steel strand and having multiple sets of mounting holes along the axial direction; a bearing seat fitted on the outside of the traction bolt and connected to it; a rotating component mounted on the bearing seat and rotatably engaged with it; and a rotating lug connected to the rotating component. One end of the rotating component passes through the bearing seat, while the other end, away from the traction bolt, is connected to the rotating lug. This utility model effectively improves construction efficiency, avoids excessively long threading times, and prevents the steel strand from rotating and tangling due to torque transmission caused by the rotation of the traction rope itself during threading, thus improving construction quality and reducing safety hazards.

Description

Technical Field

[0001] This utility model relates to the field of prestressed engineering technology, and more specifically, to a prestressed construction traction head. Background Technology

[0002] During prestressed construction, different construction methods can be used depending on the specific construction conditions. For steel strands with ducts shorter than 50m, manual threading can be used. For longer ducts, mechanical threading is used. The specific operating procedures and characteristics are as follows:

[0003] 1. Artificial threading

[0004] Workers wrap the ends of individual steel strands with tape or other soft materials to form "bullet heads," and push them one by one to the other end of the channel. They thread the strands in sequence, temporarily securing each one after it to prevent retraction. After adjusting the ends and completing the threading process, the exposed strand lengths are adjusted and aligned neatly.

[0005] The following problems exist with manual strand threading: poor economic efficiency, long threading time per strand, and high manpower requirements; low safety factor, as the elasticity of the steel strands is released during threading, which can easily cause safety accidents; poor construction quality, as there is a high probability of crossing or twisting of the steel strands during threading; and the speed control of manual threading is not precise, which can easily cause damage to the corrugated pipe and steel strands.

[0006] 2. Mechanical threading

[0007] Single-hole threading: The threading machine is fixed at the entrance of the duct. A single steel strand is clamped in the machine's fixture, and the end is wrapped. The machine is then started to push the steel strand into the duct. During the threading process, manual assistance is used to adjust the direction to prevent the steel strand from scraping against the duct wall. This method results in poor construction quality. Single-hole mechanical threading also cannot prevent the steel strand from crossing or twisting inside the corrugated pipe. Furthermore, repeatedly threading a single steel strand can easily scratch the inner wall of the corrugated pipe, increasing the duct breakage rate.

[0008] Overall stranding: A winch is used for overall stranding. Before stranding begins, multiple steel strands are arranged according to the designed quantity, tied together with a binding strap every 1.5-2 meters to maintain parallelism, and connected to the traction head at the top. The winch is fixed at the outlet end of the duct, and the traction rope passes through the duct and connects to the steel strand bundle traction head. A guide pulley is installed at the inlet end of the duct to reduce frictional resistance. The winch is started to pull at a uniform speed, while the arrangement of the steel strands is monitored simultaneously. This method of using a rotating traction rope to transmit torque to the steel strand bundle can cause the steel strands to twist and entangle, resulting in a larger deviation in the control stress value during prestressing tensioning. Utility Model Content

[0009] The technical problem to be solved by this utility model is to provide a prestressed concrete strand threading traction head that can improve construction efficiency and avoid excessively long threading time; it can also prevent the steel strand from rotating and twisting due to the torque transmission generated by the rotation of the traction rope itself during the threading process, thereby improving construction quality and reducing safety hazards;

[0010] The solution adopted by this utility model to solve the technical problem is:

[0011] A prestressed construction traction head includes a traction bolt connected to a steel strand and having multiple sets of mounting holes along the axial direction, a bearing seat fitted on the outside of the traction bolt and connected to the traction bolt, a rotating component mounted on the bearing seat and rotatably engaged with the bearing seat, and a rotating lifting lug connected to the rotating component.

[0012] One end of the rotating assembly passes through the bearing housing and is connected to the rotating lug at the end away from the traction bolt.

[0013] In use, the center wire of the steel strand is connected to the traction bolt through the mounting hole; the rotating assembly is installed in the bearing housing, and then the traction bolt is connected to the bearing housing. The end of the rotating assembly away from the traction bolt passes through the bearing housing and is connected to the rotating lug. Finally, the rotating lug is connected to the traction device through the traction rope.

[0014] During the traction process, the rotating component ensures that the traction bolts connected to the steel strands rotate in conjunction with the rotating lugs, effectively preventing the steel strands from rotating and getting tangled due to the torque transmission generated by the rotation of the traction rope itself. This improves construction quality, reduces safety hazards, and optimizes the construction process.

[0015] In some possible implementations, in order to effectively achieve the rotational engagement between the traction bolt and the rotating lug through a rotating assembly, the rotating assembly includes a pressure bearing fitted inside a bearing housing and a rotating bolt mounted on the pressure bearing and having one end passing through the pressure bearing housing and connected to the rotating lug.

[0016] In some possible implementations, the bearing housing includes a sleeve fitted around the outside of the traction bolt and screwed in, and an end plate disposed at the end of the sleeve away from the traction bolt and integrally formed with the sleeve; the end plate is provided with a through hole for the end of the rotating bolt away from the traction bolt to pass through; the through hole is coaxially arranged with the sleeve.

[0017] In some possible implementations, the traction bolt includes a threaded post that is screwed into a sleeve, and a disc disposed at the end of the threaded post away from the rotating assembly and coaxial with the threaded post; the mounting hole is disposed along the axial direction of the threaded post and passes through the traction bolt.

[0018] In some possible implementations, in order to effectively prevent the rotating bolt from moving along the sleeve axis during use, a limiting component is provided inside the sleeve to restrict the movement of the rotating bolt along the sleeve axis.

[0019] In some possible implementations, the limiting component includes an annular groove disposed within the sleeve and above the disk, and an elastic limiting piece installed within the annular groove and having elasticity; the annular groove is coaxially disposed with the sleeve.

[0020] In some possible implementations, in order to effectively install the elastic limiting piece in the original slot, the elastic limiting piece has an arc-shaped structure, including an arc-shaped thin sheet and two sets of ear pieces disposed on the thin sheet and located on the inner side of the thin sheet.

[0021] In some possible implementations, the width of the sheet is greater than the width of the annular groove.

[0022] In some possible implementations, the rotating bolt includes a nut installed inside a sleeve and located on the side of the limiting assembly away from the traction bolt, a connecting portion integrally formed with the nut and fitted inside a pressure bearing, and a connecting rod connected to the end of the connecting portion away from the nut and provided with external threads.

[0023] In some possible implementations, in order to effectively achieve the connection between the rotating lug and the connecting rod and the traction rope, the rotating lug includes a lug seat that is screwed into the connecting rod, and a connecting rod connected to the end of the lug seat away from the connecting rod; a locking screw that abuts against the outer side of the connecting rod is installed on the lug seat.

[0024] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0025] This invention uses a pressure bearing to interrupt torque transmission, ensuring a straight and smooth path for the steel strands, and preventing rotation or tangling of the steel strands and traction ropes. Compared to single-hole threading, the prestressing tension control achieves the required stress deviation and steel strand elongation.

[0026] Using this utility model as a structurally stable construction component allows for repeated use during project turnover, exhibits good durability, and reduces overall costs.

[0027] Using this invention for prestressed tendon threading not only simplifies the construction process but also saves a significant amount of manpower, effectively conserves resources, and shortens the construction period, demonstrating excellent economic efficiency. Furthermore, using this invention for one-time tendon threading avoids the safety risks associated with repeated threading in a single hole. Simultaneously, reducing construction steps effectively lowers the safety risks for operators and enhances the overall safety of the project. Attached Figure Description

[0028] Figure 1This is a schematic diagram of the structure of this utility model;

[0029] Figure 2 This is a schematic diagram of the traction bolt in this utility model;

[0030] Figure 3 This is a schematic diagram of the bearing housing structure in this utility model;

[0031] Figure 4 This is a schematic diagram of the elastic limiting piece in this utility model;

[0032] Figure 5 This is a schematic diagram of the rotating lifting lug of this utility model;

[0033] Figure 6 This is a schematic diagram of the rotating bolt in this utility model;

[0034] in:

[0035] 1. Traction bolt; 11. Threaded post; 12. Disc; 13. Mounting hole;

[0036] 2. Bearing housing; 21. Sleeve; 22. End plate; 221. Through hole; 23. Limiting assembly; 231. Annular groove; 232. Elastic limiting piece; 2321. Thin sheet; 2322. Ear piece;

[0037] 3. Rotating assembly; 31. Pressure bearing; 32. Rotating bolt; 321. Nut; 322. Connecting part; 323. Connecting rod;

[0038] 4. Rotating lug; 41. Lug seat; 42. Connecting rod. Detailed Implementation

[0039] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0040] The present invention will now be described in detail.

[0041] like Figures 1-6 As shown:

[0042] A prestressed construction traction head includes a traction bolt 1 connected to a steel strand and having multiple sets of mounting holes 101 along the axial direction, a bearing seat 2 fitted on the outside of the traction bolt 1 and connected to the traction bolt 1, a rotating component 3 installed in the bearing seat 2 and rotatably engaged with the bearing seat 2, and a rotating lug 4 connected to the rotating component 3.

[0043] One end of the rotating component 3 passes through the bearing seat 2 and the other end away from the traction bolt 1 and is connected to the rotating lug 4.

[0044] In use, the center wire of the steel strand is connected to the traction bolt 1 through the mounting hole 101; the rotating component 3 is installed in the bearing seat 2, then the traction bolt 1 is connected to the bearing seat 2, and the end of the rotating component 3 away from the traction bolt 1 passes through the bearing seat 2 and is connected to the rotating lug 4. Finally, the rotating lug 4 is connected to the traction device through the traction rope.

[0045] During the traction process, the rotating component 3 enables the traction bolt 1 connected to the steel strand to rotate and engage with the rotating lug 4, thereby effectively preventing the steel strand from rotating and tangling due to the torque transmission generated by the rotation of the traction rope itself, improving construction quality, reducing safety hazards, and optimizing the construction process.

[0046] In some possible implementations, such as Figure 1, Figure 3 As shown, in order to effectively achieve the rotational engagement between the traction bolt 1 and the rotating lug 4 through the rotating assembly 3, the rotating assembly 3 includes a pressure bearing 31 fitted inside the bearing housing 2, and a rotating bolt 32 mounted on the pressure bearing 31 and having one end pass through the pressure bearing 31 to connect the bearing housing 2 and the rotating lug 4.

[0047] The pressure bearing 31 is coaxially mounted in the bearing housing 2 and the outer ring of the pressure bearing 31 is interference-fitted with the bearing housing 2. The rotating bolt 32 is fitted in the inner ring of the pressure bearing 31 and the two are interference-fitted. The end of the rotating bolt 32 away from the traction bolt 1 passes through the bearing housing 2 and is connected to the rotating lug 4.

[0048] When the traction rope rotates, it will drive the rotating lug 4, the rotating bolt 32, and the inner ring of the pressure bearing 31 to rotate. Since the inner ring of the pressure bearing 31 rotates and engages with its outer ring, the bearing seat 2 and the traction bolt 1 that engage with the outer ring of the pressure bearing 31 will not rotate, thus avoiding the phenomenon of the steel strand getting tangled.

[0049] In some possible implementations, such as Figure 3 As shown, the bearing housing 2 includes a sleeve 21 that is fitted onto the outside of the traction bolt 1 and screwed together, and an end plate 22 that is disposed at the end of the sleeve 21 away from the traction bolt 1 and integrally formed with the sleeve 21; a through hole 221 is provided on the end plate 22 for the end of the rotating bolt 32 away from the traction bolt 1 to pass through; the through hole 221 is coaxially arranged with the sleeve 21.

[0050] Furthermore, the sleeve 21 is provided with an internal threaded hole for use with the traction bolt 1, and an inner hole for installing the rotating bolt 32 and coaxial with the internal threaded hole. The inner hole is coaxial with and connected to the through hole 221. The inner diameter of the internal threaded hole is larger than the inner diameter of the inner hole. The connection between the internal threaded hole and the inner hole forms a limiting contact surface. The end plate 22 is used to limit the pressure bearing 31 from sliding out of the sleeve 21 during the traction process.

[0051] In some possible implementations, such as Figure 1 , Figure 2 As shown, the traction bolt 1 includes a threaded post 11 that is screwed into the sleeve 21, and a disc 12 that is disposed at the end of the threaded post 11 away from the rotating assembly 3 and coaxial with the threaded post 11.

[0052] The disc 12 will be installed on the outside of the sleeve 21; the mounting hole 101 is provided along the axial direction of the threaded post 11 and passes through the traction bolt 1;

[0053] The threaded post 11 is screwed into the internal threaded hole to connect with the sleeve 21; the mounting hole 101 is used to connect the center wire of the steel strand to the traction bolt 1.

[0054] Preferably, the multiple sets of mounting holes 101 include a central hole coaxial with the disk 12, multiple sets of holes two that are equidistant from the central hole and uniformly arranged along the circumference of the central hole, and multiple sets of holes three that are arranged outside the holes two and equidistant from the central hole; the multiple sets of holes three are uniformly arranged along the circumference of the central hole; the distance between the holes two and the central hole is less than the distance between the holes three and the central hole.

[0055] In some possible implementations, such as Figure 1 , Figure 4 As shown, in order to effectively prevent the rotating bolt 32 from moving along the axial direction of the sleeve 21 during use, a limiting component 23 is provided inside the sleeve 21 to restrict the movement of the rotating bolt 32 along the axis of the sleeve 21; the limiting component 23 is located between the rotating bolt 32 and the threaded post 11 and is located inside the inner hole.

[0056] In some possible implementations, the limiting component 23 includes an annular groove 2311 disposed within the sleeve 21 and located above the disc 12, and an elastic limiting piece 232 installed within the annular groove 2311 and having elasticity; the annular groove 2311 is coaxially disposed with the sleeve 21.

[0057] The cross-section of the annular groove 2311 is U-shaped and communicates with the inner hole; thus effectively realizing the installation of the elastic limiting piece 232;

[0058] In use, after the rotating bolt 32 passes through the through hole 221 and connects to the rotating lug 4, the elastic limiting piece 232 is installed in the annular groove 2311, thereby limiting and fixing the rotating bolt 32.

[0059] In some possible implementations, in order to effectively install the elastic limiting piece 232 in the annular groove 2311, the elastic limiting piece 232 has an arc-shaped structure, including an arc-shaped thin sheet 2321 and two sets of ear pieces 2322 disposed on the thin sheet 2321 and located on the inner side of the thin sheet 2321; the two sets of ear pieces 2322 are provided with holes.

[0060] When installing the elastic limiting piece 232, the thin piece 2321 is deformed by the use of the hole and other mating parts, so that the deformed thin piece 2321 can pass through the threaded hole and enter the inner hole. When it is moved to the corresponding position of the annular groove 2311, no force is applied to the thin piece 2321, and the thin piece 2321 will return to its initial state, thus realizing installation in the annular groove 2311.

[0061] In some possible implementations, such as Figure 4As shown, the width of the thin plate 2321 is greater than the width of the annular groove 2311. This arrangement will allow the thin plate 2321 and the end of the rotating bolt 32 near the traction bolt 1 to have a larger contact surface, thereby limiting the rotation bolt 32.

[0062] In some possible implementations, such as Figure 6 As shown, the rotating bolt 32 includes a nut 321 installed in the sleeve 21 and located on the side of the limiting component 23 away from the traction bolt 1, a connecting part 322 integrally formed with the nut 321 and fitted in the pressure bearing 31, and a connecting rod 323 connected to the end of the connecting part 322 away from the nut 321 and provided with external threads.

[0063] Preferably, a tongue and groove is provided on the side of the nut 321 near the traction bolt 1. The tongue and groove facilitates the screwing of the connecting rod and the rotating lug 4. The connecting part 322 is interference-fitted with the inner ring of the pressure bearing 31. The end of the connecting part 322 away from the traction bolt 1 is coplanar with the outer side of the end plate 22. After the connecting rod 323 is connected to the rotating lug 4, the end plate 22 and the rotating lug 4 are in a small clearance fit on the side close to each other, thereby avoiding contact friction between the two and the situation where they cannot rotate.

[0064] In some possible implementations, such as Figure 5 As shown, in order to effectively connect the rotating lug to the connecting rod 323 and the traction rope, the rotating lug 4 includes a lug 41 that is screwed into the connecting rod 323, and a connecting rod 42 that is connected to the end of the lug 41 away from the connecting rod 323; a locking screw that abuts against the outer side of the connecting rod 323 is installed on the lug 41; a connecting hole for connecting the traction rope is provided on the connecting rod 42; a screw hole for screwing into the connecting rod is provided on the lug 41, and an opening for use with the locking screw and communicating with the screw hole, the axis of the opening being perpendicular to the axis of the screw hole.

[0065] Furthermore, the pressure bearing is a FAG 33005 type pressure bearing, with a rated static load of 4.8 tons and a dynamic load of 3.2 tons, far exceeding the load-bearing capacity of traditional traction heads (usually ≤2 tons). Through the integrated design of the pressure bearing and the traction bolt, this device can withstand an axial pressure of more than 4 tons, making it suitable for large-tonnage steel strand bundles. When used with a strand threading machine and a winch, it can meet the one-time strand threading requirements of ultra-long ducts (L>100m), ensuring the stability and safety of construction.

[0066] The method was used in the construction of a bridge project, where the prestressed strand threading operation was carried out in two hours, which greatly reduced the construction time (the traditional method requires 4.5 hours). The steel strands did not cross or entangle, and the tension stress deviation was ≤2%.

[0067] This invention is not limited to the specific embodiments described above. This invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A prestressed tendon traction head for prestressed construction, characterized in that, It includes a traction bolt connected to the steel strand and having multiple sets of mounting holes along the axial direction, a bearing housing fitted on the outside of the traction bolt and connected to the traction bolt, a rotating assembly mounted on the bearing housing and rotatingly engaged with the bearing housing, and a rotating lifting lug connected to the rotating assembly. One end of the rotating assembly passes through the bearing housing and is connected to the rotating lug at the end away from the traction bolt.

2. The threading head for use in prestressed construction according to claim 1, characterized in that The rotating assembly includes a pressure bearing housed within a bearing housing and a rotating bolt mounted on the pressure bearing, with one end passing through the pressure bearing housing and connected to a rotating lug.

3. The threading head for use in prestressed construction according to claim 2, characterized in that The bearing housing includes a sleeve fitted on the outside of the traction bolt and screwed together, and an end plate disposed at the end of the sleeve away from the traction bolt and integrally formed with the sleeve; the end plate is provided with a through hole for the end of the rotating bolt away from the traction bolt to pass through; the through hole is coaxially arranged with the sleeve.

4. The threading head for use in prestressed construction according to claim 3, characterized in that The traction bolt includes a threaded post that is screwed into the sleeve, and a disc located at the end of the threaded post away from the rotating component and coaxial with the threaded post; the mounting hole is located along the axial direction of the threaded post and passes through the traction bolt.

5. The threading head for use in prestressed construction according to claim 3, characterized in that A limiting component is provided inside the sleeve to restrict the movement of the rotating bolt along the sleeve axis.

6. A prestressed tendon traction head for prestressed construction according to claim 5, characterized in that, The limiting component includes an annular groove disposed inside the sleeve and above the disc, and an elastic limiting piece installed inside the annular groove and having elasticity; the annular groove is coaxially arranged with the sleeve.

7. A prestressed tendon traction head for prestressed construction according to claim 6, characterized in that, The elastic limiting piece has an arc-shaped structure, including an arc-shaped thin sheet and two sets of ear pieces disposed on the thin sheet and located on the inner side of the thin sheet.

8. A prestressed tendon traction head for prestressed construction according to claim 7, characterized in that, The width of the thin sheet is greater than the width of the annular groove.

9. A prestressed tendon traction head for prestressed construction according to claim 5, characterized in that, The rotating bolt includes a nut installed inside the sleeve and located on the side of the limiting assembly away from the traction bolt, a connecting part integrally formed with the nut and fitted inside the pressure bearing, and a connecting rod connected to the end of the connecting part away from the nut and provided with external threads.

10. A prestressed tendon traction head for prestressed construction according to claim 9, characterized in that, The rotating lug includes a lug seat that is screwed into the connecting rod, and a connecting rod that is connected to the end of the lug seat away from the connecting rod; a locking screw that abuts against the outer side of the connecting rod is installed on the lug seat.

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