Prestressed steel strand pulling device

Abstract

The utility model belongs to the technical field of prestressed anchorage devices, and particularly relates to a prestressed steel strand pulling device. According to the utility model, the pre-stressed steel strands are suspended and separated through the front-end moving frame, the middle supporting frame and the tail-end limiting disc which are sequentially arranged at intervals, so that the risk of winding and crossing phenomena of the pre-stressed steel strands in the strand pulling process can be reduced; meanwhile, the prestressed steel strand is driven to penetrate through the first rolling device and the second rolling device, and friction between the prestressed steel strand and the corrugated pipe is reduced. The device is high in adaptability and good in universality and adaptability, and can be widely applied to various prestressed structure projects such as bridges and aqueducts.

Description

Technical Field

[0001] This utility model belongs to the field of prestressed anchor technology, specifically relating to a prestressed steel strand threading device. Background Technology

[0002] Prestressed technology is a crucial technique in modern construction engineering, widely applied in large-span structures, aqueducts, bridges, and other large-scale foundation structures. Prestressed technology primarily involves threading prestressed steel strands through structural openings to apply tension, thereby enhancing the structure's load-bearing capacity and stability. As the core component of prestressed structures, the quality of the strand threading process directly impacts the performance and safety of the prestressed structure.

[0003] With the increasing prevalence of building structures operating under extreme conditions, the challenges to structural safety are becoming more severe, undoubtedly placing higher demands on the stranding process of steel strands. Currently, the number of steel strands typically ranges from 3 to 27. In cases with a larger number of strands, the inner diameter of the circular plastic corrugated tubing can even reach approximately 130mm. Any errors during the stranding process can lead to strand entanglement, broken wires, insufficient prestress, and other issues, resulting in decreased structural performance and even safety accidents. Therefore, developing efficient, precise, and safe stranding methods is crucial for ensuring structural safety and improving the overall construction quality when stranding multiple steel strands.

[0004] Traditional stranding techniques often require welding multiple steel strands together and then pushing or pulling them through a corrugated pipe. This method is not only inefficient but also wastes materials as the welded sections must be removed after stranding. In structures such as ultra-long aqueducts and bridges, the steel strands, due to their inherent flexibility rather than being perfectly straight, are prone to tangling and crossing during stranding, significantly increasing safety risks. The considerable friction between the steel strands and the corrugated pipe in traditional methods reduces stranding efficiency and may also damage the steel strands.

[0005] Furthermore, Chinese patent document CN201874247U discloses a device for threading prestressed steel strands through a corrugated pipe. The device has the extension direction of the corrugated pipe to be threaded through as the axial direction and the direction facing the inner wall of the corrugated pipe as the radial direction. It includes a traction device with an internal cavity and an external connecting device, and a bundler that is embedded in the cavity and connected and fixed to the traction device. The bundler has a plurality of through holes, the diameter of which is larger than the core diameter of the prestressed steel strand to be threaded through the corrugated pipe. The radial dimensions of the traction device and the bundler are both smaller than the inner diameter of the corrugated pipe. This scheme uses a bundler to gather the steel cores of the prestressed steel strands and pass all the strands through the corrugated pipe at once, eliminating the previous cumbersome steps of bundling and pulling in batches. The threading is quick and convenient. However, this scheme does not consider how to avoid tangling and crossing of the steel strands as a whole, nor does it consider how to avoid friction between the steel strands and the corrugated pipe. After the steel cores of the prestressed steel strands pass through the through holes on the bundler, they are flattened and anchored. After the threading is completed, the exposed steel cores need to be cut off, which still results in material waste.

[0006] Chinese patent document CN103938874A discloses a prestressed steel strand threading and traction device and its threading method. The tail of the traction device is a bearing plate for connecting the middle wire of the traction steel strand; the middle of the traction device is an adapter nut for connecting the bearing plate and the conical traction head; the head of the traction device is a conical traction head for connecting the traction steel wire rope; the bearing plate, adapter nut, and conical traction head are connected to each other by threaded interlocking. This solution uses the middle straight wire of the steel strand to constrain the bearing plate, the conical traction head for traction, and the adapter nut for connection. The use of the middle straight wire of the steel strand for head traction effectively solves the problem of threading traditional steel strands. The working principle of this scheme is similar to that of the Chinese patent document with publication number CN201874247U mentioned above. It does not consider how to avoid entanglement and crossing of the steel strand as a whole, nor does it consider how to avoid friction between the steel strand and the corrugated pipe. The straight wires of the prestressed steel strand in this scheme are treated with head-up. After the stranding is completed, some prestressed steel strands still need to be cut. Otherwise, the prestressed steel strands cannot be separated from the stranding and traction device, which also results in material waste. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a prestressed steel strand threading device, which can reduce the risk of entanglement and crossing of prestressed steel strands during the threading process, and at the same time reduce the risk of structural performance deterioration caused by the threading of prestressed steel strands.

[0008] The technical solution adopted by this utility model to solve its technical problem is: a prestressed steel strand threading device, including a front bearing plate, a plurality of first threading holes for steel strands provided on the front bearing plate, a traction mechanism provided at the front end of the front bearing plate, the traction mechanism including at least a first traction rope, and a front moving frame, an intermediate support frame and an end limiting plate arranged sequentially at intervals. The front bearing plate is fixedly mounted on the front moving frame, the front moving frame is equipped with a first rolling device that enables it to move along the axial direction of the corrugated pipe inside the corrugated pipe, the intermediate support frame is equipped with a second rolling device that enables it to move along the axial direction of the corrugated pipe inside the corrugated pipe, the front moving frame and the intermediate support frame are connected by a connecting rope, at least one intermediate limiting plate is provided on the intermediate support frame, a plurality of second threading holes for steel strands corresponding one-to-one with the first threading holes for steel strands are provided on the intermediate limiting plate, and a plurality of third threading holes for steel strands corresponding one-to-one with the first threading holes for steel strands are provided on the end limiting plate.

[0009] A further preferred embodiment includes multiple prestressed steel strands, with each prestressed steel strand corresponding to a first pass-through hole. The end of each prestressed steel strand that passes through the first pass-through hole is rolled to form a threaded section. The threaded section is equipped with a limiting nut, which is located on the side of the front bearing plate away from the intermediate support frame to provide axial limiting for the prestressed steel strand.

[0010] A further preferred embodiment is that the traction mechanism includes a winch, a linear directional movement device, and a second traction rope. One end of the first traction rope is connected to the winch and the other end is connected to the linear directional movement device. One end of the second traction rope is connected to the linear directional movement device and the other end is connected to the front-end moving frame.

[0011] A further preferred embodiment is that at least one intermediate support plate is fixedly installed on the front-end movable frame. The intermediate support plate is located on the side of the front-end support plate facing the intermediate support frame. The intermediate support plate is provided with a plurality of fourth strand through holes corresponding one-to-one with the first strand through holes.

[0012] A further preferred embodiment is that the front-end movable frame includes a first arc-shaped groove with its opening facing the top. The length direction of the first arc-shaped groove is consistent with the axial direction of the first through hole. The first rolling device includes casters. A row of casters is provided at the middle position of the bottom surface of the first arc-shaped groove. At least one row of casters is provided on each side of the bottom surface of the first arc-shaped groove. Each row of casters includes multiple casters spaced apart along the length direction of the first arc-shaped groove. Each caster is mounted on the bottom surface of the first arc-shaped groove by a spring telescopic rod.

[0013] A further preferred embodiment is that the intermediate limiting plates are arranged at intervals, and each intermediate limiting plate is provided with a second through hole; the intermediate support frame includes a second arc-shaped groove with its opening facing the top, the length direction of the second arc-shaped groove is consistent with the axis direction of the second through hole, the second rolling device includes casters, a row of casters is provided at the middle position of the bottom surface of the second arc-shaped groove, and at least one row of casters is provided on each side of the bottom surface of the second arc-shaped groove, and a single row of casters includes multiple casters spaced apart along the length direction of the second arc-shaped groove, each caster being installed on the bottom surface of the second arc-shaped groove by a spring telescopic rod.

[0014] A further preferred embodiment is that the intermediate support frames are multiple and spaced apart, with adjacent support frames connected by connecting ropes.

[0015] A further preferred embodiment is that the end limiting plate includes a fixing plate, one side surface of which has a positioning plate that is raised, and the third through hole of the steel strand is located in the area of ​​the positioning plate; the positioning plate is used to engage with the corresponding end opening of the corrugated pipe.

[0016] In its specific implementation, this utility model includes the following steps:

[0017] First, thread the first traction rope through both ends of the corrugated pipe;

[0018] Number the prestressed steel strands with the designed length;

[0019] Connect the front movable frame and the middle support frame with connecting ropes;

[0020] The prestressed steel strands pass through the third strand-passing hole on the end limiting plate, the second strand-passing hole on the intermediate limiting plate, and the first strand-passing hole on the front bearing plate in sequence according to their numbers, so as to achieve the separation and positioning of the prestressed steel strands; if an intermediate bearing plate is provided, the prestressed steel strands also pass through the fourth strand-passing hole on the intermediate bearing plate in sequence according to their numbers.

[0021] This ensures that the end of the prestressed steel strand that passes through the first through hole of the steel strand is relatively fixed relative to the front bearing plate in the direction of the axis of the prestressed steel strand;

[0022] Connect the first traction rope to the power mechanism in the traction mechanism, apply tension to the first traction rope, and make the prestressed steel strand advance inside the corrugated pipe.

[0023] Once the prestressed steel strands have advanced to their designated positions, the front moving frame is retrieved, the intermediate support frame is then pulled out via the connecting rope, the end limiting plate is removed, and finally the prestressed steel strands are separated according to their assigned numbers.

[0024] A further preferred embodiment is that the prestressed steel strands are pre-straightened using a strand threading machine before being matched and connected with the third, second, and first strand threading holes.

[0025] The beneficial effects of this utility model are: This utility model uses a front-end moving frame, a middle support frame and an end limiting plate arranged in sequence to suspend and separate the prestressed steel strands, which can reduce the risk of entanglement and crossing of the prestressed steel strands during the threading process. At the same time, the first rolling device and the second rolling device are used to drive the prestressed steel strands through the threading process, which reduces the friction between the prestressed steel strands and the corrugated pipe.

[0026] This invention incorporates an adaptive environmental design. By installing 360° rotatable casters at the bottom of the front movable frame and the bottom of the middle support frame, and by installing the casters via spring telescopic rods, a scaling function along the diameter direction is achieved. This allows for better adaptation to the shape of the corrugated pipe, reduces the probability of rotation inside the corrugated pipe, and improves the stability of the threading process.

[0027] The front-end moving frame and the intermediate support frame of this utility model both adopt arc-shaped groove structures with openings facing the top as the main structure. The overall center of gravity of the device is low, and it is connected to the front-end moving frame through a linear directional moving device and a second traction rope. This ensures that the traction mechanism does not generate other axial torques when providing tension. These two designs effectively prevent the prestressed steel strands from deviating from the predetermined trajectory during traction and from tangling and crossing during long-distance stranding, thus improving the safety and efficiency of construction.

[0028] The prestressed steel strand of this utility model is fixed by threads. The limiting nut equipped with the threaded section of the steel strand plays an axial limiting role for the prestressed steel strand, thereby allowing the prestressed steel strand to move forward with the front moving frame without welding. At the same time, after the subsequent stranding is completed, there is no need to cut off the end of the prestressed steel strand. This not only avoids the material waste that may occur during the welding process, but also improves the stranding efficiency.

[0029] This utility model is highly adaptable and has good versatility and adaptability, and can be widely used in various prestressed structure projects such as bridges and aqueducts. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0031] Figure 2 This is a schematic diagram of the front movable frame in the front view of this utility model;

[0032] Figure 3 This is a schematic diagram of the structural relationship between the front-end movable frame and the corrugated pipe in the radial section during the implementation of this utility model;

[0033] Figure 4 This is a schematic diagram of the installation structure of the universal wheel in this utility model;

[0034] Figure 5 This is a side view of the intermediate support frame in some other embodiments of the present invention;

[0035] Figure 6 This is a schematic diagram of the end-positioning disc in the present invention viewed from the front.

[0036] Figure 7 yes Figure 6 The left view;

[0037] Figure 8 This is a flowchart of the threading method in the implementation of this utility model.

[0038] Figures 1 to 7 The components are marked as follows: front moving frame 10, front bearing plate 11, first strand threading hole 111, middle bearing plate 12, middle support frame 20, middle limiting plate 21, second strand threading hole 211, end limiting plate 30, third strand threading hole 301, fixing plate 31, positioning plate 32, corrugated pipe 40, prestressed steel strand 50, connecting rope 60, limiting nut 70, first traction rope 81, linear directional moving device 82, second traction rope 83, caster wheel 90, spring telescopic rod 91, rolling ball 92. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0040] like Figures 1 to 7 As shown, the prestressed steel strand threading device of this utility model includes a front bearing plate 11, on which a plurality of first threading holes 111 for steel strands are provided. A traction mechanism is provided at the front end of the front bearing plate 11. The traction mechanism includes at least a first traction rope 81 and includes a front moving frame 10, an intermediate support frame 20 and an end limiting plate 30 arranged sequentially at intervals. The front bearing plate 11 is fixedly mounted on the front moving frame 10. The front moving frame 10 is equipped with a first roller that allows it to move axially within the corrugated pipe 40. The moving device, the intermediate support frame 20 is equipped with a second rolling device that enables it to move axially within the corrugated pipe 40. The front moving frame 10 and the intermediate support frame 20 are connected by a connecting rope 60. The intermediate support frame 20 is provided with at least one intermediate limiting plate 21. The intermediate limiting plate 21 is provided with a plurality of second stranding holes 211 corresponding to the first stranding holes 111 of the steel strands. The end limiting plate 30 is provided with a plurality of third stranding holes 301 corresponding to the first stranding holes 111 of the steel strands.

[0041] It is understandable that, since the front-end bearing plate 11 is fixedly mounted on the front-end moving frame 10, and the front-end moving frame 10 can move axially within the corrugated pipe 40, the overall shape and dimensions of the structure formed by the front-end bearing plate 11 and the front-end moving frame 10 should match the corrugated pipe 40. Similarly, the overall shape and dimensions of the structure formed by the intermediate limiting plate 21 and the intermediate support frame 20 should also match the corrugated pipe 40. The end limiting plate 30 serves two purposes: firstly, it provides overhead isolation for the prestressed steel strand 50; secondly, it prevents the prestressed steel strand 50 from passing over its end (i.e., it prevents the end of the prestressed steel strand 50 from entering the corrugated pipe 40). The dimensions of the end limiting plate 30 should also match the corrugated pipe 40, and the end limiting plate 30 is generally not allowed to move entirely into the corrugated pipe 40. For a simple and reliable structure, please refer to [reference needed]. Figure 6 and Figure 7 In a preferred embodiment, the end-limiting disc 30 includes a fixing disc 31. One side surface of the fixing disc 31 has a protruding positioning disc 32. The third through-hole 301 of the steel strand is located in the area of ​​the positioning disc 32. The positioning disc 32 is used to engage with the corresponding end opening of the corrugated pipe 40, preventing the end-limiting disc 30 from falling off even without other fixing measures. Since the positioning disc 32 needs to engage with the corresponding end opening of the corrugated pipe 40, it is generally designed as a circular structure. The external structure of the fixing disc 31 is generally not specifically required; in a preferred embodiment, the fixing disc 31 adopts a concentric circle structure. The fixing disc 31 is generally a solid structure, while the positioning disc can be either a solid structure or a hollow structure.

[0042] In the embodiment shown in the accompanying drawings of this utility model, 15 bundles of 17.8mm prestressed steel strands 3 are used as an example, and the post-tensioning method is adopted for tensioning. The inner diameter of the corrugated pipe 40 is 120mm. The positioning plate 32 is a hollow cylindrical structure. The outer diameter of the positioning plate 32 is 5mm smaller than the inner diameter of the corrugated pipe 40. The wall thickness of the positioning plate 32 is 2mm, and the axial length (i.e., the protrusion height relative to the fixed plate 31) is 5cm. The positioning plate 32 is a solid disc with a thickness of 1cm and a diameter 3cm larger than the inner diameter of the corrugated pipe 40. The front bearing plate 11 and the middle limiting plate 21 are both circular structures with a diameter 2cm smaller than the inner diameter of the corrugated pipe.

[0043] To better provide overhead isolation for the prestressed steel strands 3, in a preferred embodiment, at least one intermediate bearing plate 12 is fixedly installed on the front-end movable frame 10. The intermediate bearing plate 12 is located on the side of the front-end bearing plate 11 facing the intermediate support frame 20, and the intermediate bearing plate 12 is provided with a plurality of fourth steel strand through holes corresponding one-to-one with the first through holes 111 of the steel strands. Figure 1 and Figure 2In the preferred embodiment shown, a middle support plate 12 is fixedly installed on the front-end moving frame 10. The front-end support plate 11 and the middle support plate 12 are located at the two ends of the front-end moving frame 10 in the length direction, respectively. The net space distance between the front-end support plate 11 and the middle support plate 12 in the horizontal direction is designed to be 20cm.

[0044] In a specific implementation, this utility model includes multiple prestressed steel strands 50, each prestressed steel strand 50 corresponding to a first through hole 111. A preferred limiting and fixing scheme for the prestressed steel strands 50 is as follows: (See attached diagram) Figure 1 and Figure 2 Each prestressed steel strand 50 has a threaded section formed at one end through the first threading hole 111. The threaded section is equipped with a limiting nut 70, which is positioned on the side of the front bearing plate 11 away from the intermediate support frame 20 to axially limit the prestressed steel strand 50. This not only improves threading efficiency but also avoids material waste (after threading, only the limiting nut 70 needs to be unscrewed; the end of the prestressed steel strand 50 does not need to be cut off). When the space on the front bearing plate 11 is insufficient, the limiting nuts 70 can be staggered. The first set of limiting nuts 70 directly contacts the end face of the front bearing plate 11, while the second set contacts the end face of the first set. In some alternative embodiments, the limiting and fixing scheme of the prestressed steel strand 50 may also refer to the Chinese patent documents mentioned in the background art (CN201874247U and CN103938874A).

[0045] In a preferred embodiment, the traction mechanism includes a winch, a linear directional moving device 82, and a second traction rope 83. One end of the first traction rope 81 is connected to the winch, and the other end is connected to the linear directional moving device 82. One end of the second traction rope 83 is connected to the linear directional moving device 82, and the other end is connected to the front-end moving frame 10. The linear directional moving device 82 is a conventional technology and can generally be used as a walking mechanism by setting directional wheels. This ensures that the traction mechanism does not generate other axial torques when providing tension, effectively preventing the prestressed steel strands 50 from deviating from the predetermined trajectory during traction and from tangling and crossing during long-distance threading, thus improving the safety and efficiency of construction.

[0046] In a preferred embodiment, the front-end moving frame 10 includes a first arc-shaped groove with its opening facing the top. The length direction of the first arc-shaped groove is consistent with the axial direction of the first through hole 111. The front-end support plate 11 and the middle support plate 12 are preferably designed as circular structures and are respectively fixedly disposed at the two end faces of the first arc-shaped groove. The outer circular surface of the first arc-shaped groove is preferably flush with the outer circular surfaces of the front-end support plate 11 and the middle support plate 12, that is, the three are located on the same cylindrical surface. By adopting the above-mentioned structural design of the first arc-shaped groove, the center of gravity of the front-end moving frame 10 can be lowered, reducing the risk of the front-end moving frame 10 rotating inside the bellows 40. The first rolling device includes casters 90. A row of casters 90 is provided at the middle position of the bottom surface of the first arc-shaped groove, and at least one row of casters 90 is provided on each side of the bottom surface of the first arc-shaped groove. Each row of casters 90 includes multiple casters 90 spaced apart along the length direction of the first arc-shaped groove. Each caster 90 is mounted on the bottom surface of the first arc-shaped groove by a spring telescopic rod 91. The "spring telescopic rod 91" is a conventional assembly, typically consisting of a fixed rod and a telescopic rod slidably mounted coaxially. A return spring is positioned between the fixed rod and the telescopic rod. External force overcomes the spring force of the return spring, compressing it and shortening the overall length of the "spring telescopic rod 91." When the external force disappears, the return spring's restoring force extends the overall length of the "spring telescopic rod 91." The caster wheel 90 includes a traveling wheel and a mounting bracket supporting it. The caster wheel 90 is mounted via the spring telescopic rod 91, meaning its mounting bracket is connected to one end of the spring telescopic rod 91. The "spring telescopic rod 91" can be a single set with its axis passing through the center of the caster wheel 90, or two sets can be provided, corresponding to opposite sides of the caster wheel 90. With this structural design, the caster wheel 90 can rotate 360°. When the front moving frame 10 rotates slightly, gravity automatically adjusts its direction, allowing the front moving frame 10 to move forward in a predetermined direction. In addition, the caster wheel 90 is set by a spring telescopic rod 91, which allows the caster wheel 90 to extend and retract and move freely in the axial direction of the spring telescopic rod 91. This is because the bellows 40 is not a complete circle and has a certain degree of non-circularity. The spring telescopic rod 91 can prevent the device from getting stuck in the bellows 40, thereby adapting to the uneven environment inside the bellows 40.

[0047] In some preferred embodiments, the specific structure of the intermediate support frame 20 can be designed with reference to the front moving frame 10. For example, there can be multiple intermediate limiting plates 21 arranged at intervals, and each intermediate limiting plate 21 is provided with a second through hole 211. The intermediate support frame 20 includes a second arc-shaped groove with its opening facing the top, and the length direction of the second arc-shaped groove is consistent with the axial direction of the second through hole 211. Figure 1In the illustrated embodiment, an intermediate limiting plate 21 is fixedly provided at each of the two ends of the second arc-shaped groove. The intermediate limiting plate 21 is preferably circular, and the outer circular surface of the second arc-shaped groove is preferably designed to be flush with the outer circular surface of the intermediate limiting plate 21.

[0048] Similarly, the second rolling device can also be designed with reference to the first rolling device. The second rolling device includes casters 90. A row of casters 90 is provided at the middle of the bottom surface of the second arc-shaped groove. At least one row of casters 90 is provided on each side of the bottom surface of the second arc-shaped groove. A single row of casters 90 includes multiple casters 90 spaced apart along the length of the second arc-shaped groove. Each caster 90 is mounted on the bottom surface of the second arc-shaped groove by a spring telescopic rod 91.

[0049] See Figure 5 In some alternative embodiments, the second rolling device can be implemented using rolling balls 92, with multiple rolling balls 92 spaced circumferentially on the outer peripheral surface of the intermediate limiting plate 21, each rolling ball 92 correspondingly disposed within a spherical groove on the intermediate limiting plate 21. In some alternative embodiments, the universal wheel 90 and the rolling ball 92 can also be combined.

[0050] Depending on the length of the prestressed steel strand 50, one or more intermediate support frames 20 can be designed accordingly. When there are multiple intermediate support frames 20 that are spaced apart, adjacent support frames 20 are connected by connecting ropes 60.

[0051] A further preferred embodiment is that the end limiting plate 30 includes a fixing plate 31, and one side surface of the fixing plate 31 has a positioning plate 32 that is raised. The third through hole 301 of the steel strand is located in the area where the positioning plate 32 is located. The positioning plate 32 is used to be engaged in the corresponding end opening of the corrugated pipe 40.

[0052] Further reading Figure 8 The present invention includes the following steps in its specific implementation:

[0053] First, the first traction rope 81 is threaded through both ends of the corrugated pipe 40; in a preferred embodiment, the first traction rope 81 can be in the form of steel strand, and the steel strand is threaded through both ends of the corrugated pipe 40 by a threading machine.

[0054] The prestressed steel strands 50 with the designed length are numbered, which means that the length of the prestressed steel strands 50 has been estimated and cut before they are threaded.

[0055] Connect the front movable frame 10 and the intermediate support frame 20 with a connecting rope 60; the connecting rope 60 can generally be a fiber braided rope.

[0056] The prestressed steel strands 50 pass through the third strand-passing hole 301 on the end limiting plate 30, the second strand-passing hole 211 on the intermediate limiting plate 21, and the first strand-passing hole 111 on the front bearing plate 11 in sequence according to their numbers, thereby achieving the separation and positioning of the prestressed steel strands 50; in the preferred embodiment where an intermediate bearing plate 12 is provided, the prestressed steel strands 50 also pass through the fourth strand-passing hole on the intermediate bearing plate 12 in sequence according to their numbers.

[0057] The end of the prestressed steel strand 50 that passes through the first through hole 111 is fixed relative to the front bearing plate 11 in the axial direction of the prestressed steel strand 50. In a preferred embodiment, the end of the prestressed steel strand 50 that passes through the first through hole 111 is rolled to form a threaded section of the steel strand, and the limiting nut 70 provides axial limiting for the prestressed steel strand 50.

[0058] The first traction rope 81 is connected to the power mechanism in the traction mechanism, and a tension is applied to the first traction rope 81 so that the prestressed steel strand 50 advances in the corrugated pipe 40; in the preferred embodiment, the power mechanism is generally a winch.

[0059] After the prestressed steel strand 50 has advanced to the correct position (generally, the winch can be shut down when the front moving frame 10 passes through the corrugated pipe 40 and exceeds the pipe opening position of the corrugated pipe 40 by 0.8m), the front moving frame 10 is retrieved, and then the intermediate support frame 20 is pulled out through the connecting rope 60. The end limit plate 30 is removed, and finally the prestressed steel strand 50 is separated according to the number.

[0060] In a preferred embodiment, the prestressed steel strand 50 is pre-straightened by a stranding machine before being matched and connected with the third stranding hole 301, the second stranding hole 211 and the first stranding hole 111.

[0061] The above description is only a part of the preferred embodiments of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A prestressed steel strand threading device, comprising a front end bearing plate (11), a plurality of steel strand first threading holes (111) are arranged on the front end bearing plate (11), a traction mechanism is arranged at the front end of the front end bearing plate (11), the traction mechanism at least comprises a first traction rope (81), characterized in that: The device comprises a front end moving frame (10), a middle support frame (20) and a terminal limiting disc (30) arranged in sequence, a front end bearing plate (11) is fixedly arranged on the front end moving frame (10), the front end moving frame (10) is provided with a first rolling device enabling the front end moving frame (10) to move axially in a bellows (40), the middle support frame (20) is provided with a second rolling device enabling the middle support frame (20) to move axially in the bellows (40), the front end moving frame (10) and the middle support frame (20) are connected through a connecting rope (60), at least one middle limiting plate (21) is arranged on the middle support frame (20), a plurality of steel strand second through holes (211) corresponding to the steel strand first through holes (111) are arranged on the middle limiting plate (21), and the terminal limiting disc (30) is provided with a plurality of steel strand third through holes (301) corresponding to the steel strand first through holes (111).

2. The pre-stressed steel strand threading device of claim 1, wherein: The device comprises a plurality of prestressed steel strands (50), the prestressed steel strands (50) correspond to the steel strand first through holes (111) one by one, and each prestressed steel strand (50) is used for passing through one end of the steel strand first through hole (111) to form a steel strand threaded section through rolling, the steel strand threaded section is provided with a limiting nut (70), and the limiting nut (70) is arranged on the side of the front end bearing plate (11) away from the middle support frame (20) to play an axial limiting role on the prestressed steel strand (50).

3. The pre-stressed steel strand threading device of claim 1, wherein: The traction mechanism comprises a winch, a linear directional moving device (82) and a second traction rope (83), one end of the first traction rope (81) is connected with the winch, the other end is connected with the linear directional moving device (82), one end of the second traction rope (83) is connected with the linear directional moving device (82), and the other end is connected with the front end moving frame (10).

4. The pre-stressed steel strand threading device of claim 1, wherein: At least one middle bearing plate (12) is fixedly arranged on the front end moving frame (10), the middle bearing plate (12) is located on the side of the front end bearing plate (11) facing the middle support frame (20), and a plurality of steel strand fourth through holes corresponding to the steel strand first through holes (111) are arranged on the middle bearing plate (12).

5. The pre-stressed steel strand threading device of claim 1, wherein: The front end moving frame (10) comprises a first arc-shaped groove body with an opening facing the top, the length direction of the first arc-shaped groove body is consistent with the axis direction of the first through hole (111), the first rolling device comprises universal wheels (90), a row of universal wheels (90) are arranged at the middle position of the bottom surface of the first arc-shaped groove body, at least one row of universal wheels (90) are arranged at both sides of the bottom surface of the first arc-shaped groove body, and each row of universal wheels (90) comprises a plurality of universal wheels (90) arranged at intervals along the length direction of the first arc-shaped groove body.

6. The pre-stressed steel strand threading device of claim 1, wherein: The intermediate limiting plates (21) are arranged at intervals, each of the intermediate limiting plates (21) is provided with a second bundle passing hole (211) correspondingly; the intermediate support frame (20) comprises a second arc-shaped groove body with an opening facing the top, the length direction of the second arc-shaped groove body is consistent with the axis direction of the second bundle passing hole (211), the second rolling device comprises universal wheels (90) and rolling balls (92), a row of universal wheels (90) are arranged at the middle position of the bottom surface of the second arc-shaped groove body, at least one row of universal wheels (90) are arranged at the two side positions of the bottom surface of the second arc-shaped groove body, the single row of universal wheels (90) comprises a plurality of universal wheels (90) arranged at intervals along the length direction of the second arc-shaped groove body, and each universal wheel (90) is installed on the bottom surface of the second arc-shaped groove body through a spring telescopic rod (91).

7. The pre-stressed steel strand threading device of claim 1, wherein: The intermediate support frames (20) are arranged at intervals, and two adjacent support frames (20) are connected through a connecting rope (60).

8. The pre-stressed steel strand threading device of claim 1, wherein: The end limiting disc (30) comprises a fixed disc (31), one side surface of the fixed disc (31) is provided with a positioning disc (32) in a convex manner, and a steel strand third bundle passing hole (301) is arranged in the area where the positioning disc (32) is located; the positioning disc (32) is used for being clamped in the corresponding end pipe opening of the corrugated pipe (40).

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