Prestress-adjustable suspension tensioning limiting device

Abstract

The invention is suitable for the technical field of prestress tensioning, and provides a prestress adjustable suspension tensioning limiting device which comprises a fixing support, a limiting pressing plate and a rotating piece, the fixing support is internally provided with an axial space penetrating through the two opposite ends of the fixing support in the first direction, and the limiting pressing plate comprises a pressing plate body and an external thread part which are connected with each other; the pressing plate body is arranged in the axial space in a sliding mode in the first direction, the rotating piece is rotationally installed on the fixing support and arranged on the external thread part in a sleeving mode, and an internal thread part meshed with the external thread part is arranged on the rotating piece. The limiting pressing plate is driven to move in the first direction through rotation of the rotating part, multiple lifting adjusting structures are not needed, the multiple lifting adjusting structures do not need to be operated one by one, it can be guaranteed that the limiting pressing plate integrally and synchronously moves in the first direction, and the problem that due to local deflection of the limiting pressing plate, prestressing forces on prestressing tendons are inconsistent is solved; and the time can be saved and the tensioning operation efficiency can be improved through the overall rotating operation of the rotating piece.

Description

Technical Field

[0001] The present application relates to the technical field of prestressed tensioning, and in particular to a prestressed adjustable suspended tensioning limiting device. Background Art

[0002] Currently, in the field of prestressing, there are generally two methods: suspended tensioning and limited tensioning. In conditions where the prestressed tendon needs to be tensioned multiple times, to avoid the clamps repeatedly clamping the steel strands and affecting the stress on the steel strands, or when friction tests are required before tensioning, the clamps do not need to be anchored to the steel strands and need to be suspended. Therefore, the suspended tensioning method is suitable.

[0003] In existing suspended tensioning devices, the lifting and lowering of the limit pressure plate is controlled by arranging multiple lifting control structures around the limit pressure plate, such as multiple screws. The rotation of the multiple screws is used to achieve the lifting and suspension of the limit pressure plate. The problem with this is that it is difficult to ensure the synchronous movement of the multiple lifting control structures. For example, it is difficult to accurately control the rotation of each screw to be the same, resulting in uneven force on each screw, uneven alignment of the limit pressure plate and the anchor plate, and inability to ensure uniform tracking of the clamp. Even if multiple lifting control structures are driven by electronic control, the structure is very complex, the operation is complicated, and the cost is high. Turning multiple screws results in high operational intensity and low efficiency. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a prestressed adjustable suspended tensioning limit device, which aims to solve the technical problem of the existing suspended tensioning device that it is difficult to ensure that the limit pressure plate is flush with the anchor plate.

[0005] The embodiment of the present application is implemented as follows: a prestressed adjustable suspended tensioning limit device, comprising:

[0006] A fixed bracket, wherein the fixed bracket is provided with an axial space extending through opposite ends thereof along a first direction,

[0007] A limiting pressure plate, comprising a pressure plate body and an external threaded portion connected to each other, wherein the pressure plate body is slidably disposed in the axial space along a first direction;

[0008] The rotating member is rotatably mounted on the fixing bracket, and the rotating member is provided with an internal thread portion engaged with the external thread portion.

[0009] In one embodiment, the rotating member further includes an external gear portion, and the prestressed adjustable suspended tensioning limit device further includes a drive assembly, wherein the drive assembly includes a worm, and the worm is rotatably mounted on the fixed bracket and meshes with the external gear portion.

[0010] In one embodiment, the driving assembly further includes a power member, which is disposed on the fixed bracket and is used to drive the worm to rotate.

[0011] In one embodiment, a plurality of force-applying parts are provided on the outer circumference of the rotating part, and the force-applying parts include force-applying rods, which are fixedly connected to the outer circumference of the rotating part, or the force-applying rods are detachably inserted into grooves on the outer circumference of the rotating part.

[0012] In one embodiment, the fixing bracket is further provided with a plurality of guide holes, the guide holes extending along the first direction and penetrating the inner circumferential wall and the outer circumferential wall of the fixing bracket along a second direction; the second direction is perpendicular to the first direction;

[0013] The limiting pressure plate also includes a plurality of ear plates connected to the periphery of the pressure plate body, the ear plates are provided with the external threaded portion, and each of the ear plates is slidably arranged in the guide hole along the first direction; the rotating member is sleeved with the fixed bracket.

[0014] In one embodiment, the guide hole is opened from the first axial end surface of the fixing bracket.

[0015] In one embodiment, the guide hole is opened from the first axial end face of the fixed bracket; a first limit block and a second limit block are provided on the outer wall of the fixed bracket, the first limit block and the second limit block are arranged at intervals along the first direction, and the rotating member is located at the first limit block and the second limit block; the second limit block is opened close to the first axial end face, and at least the second limit block is detachably installed.

[0016] In one embodiment, a first limit block and a second limit block are provided on the outer wall of the fixed bracket, the first limit block and the second limit block are arranged at intervals along the first direction, and the rotating member is located at the first limit block and the second limit block; at least one of the first limit block and the second limit block is detachable.

[0017] In one embodiment, the height of the ear plate along the first direction is greater than the thickness of the pressure plate body along the first direction.

[0018] In one embodiment, a height of the ear plate along the first direction is greater than a height of the rotating member along the first direction.

[0019] The prestressed adjustable suspended tensioning limiter provided in the embodiment of the present application has the following beneficial effects:

[0020] The prestressed adjustable suspended tensioning limit device provided in the embodiment of the present application has a rotating part and a limiting pressure plate that cooperate with each other in the form of a thread. The limiting pressure plate is driven to move in the first direction by the rotation of the rotating part around the fixed bracket. There is no need for multiple lifting and adjusting structures, and there is no need to operate the multiple lifting and adjusting structures one by one. It can ensure that the limiting pressure plate as a whole moves along the first direction at the same time, and the problem of inconsistent prestress on the prestressed bundle caused by local deflection of the limiting pressure plate will not occur; the rotation operation of the rotating part as a whole can save time and improve the efficiency of the tensioning operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 1 is a schematic top view of a prestressed adjustable suspended tensioning limiter provided in an embodiment of the present application;

[0023] Figure 2 yes Figure 1 Sectional view along line AA;

[0024] Figure 3 1 is a side view schematic diagram of a prestressed adjustable suspended tensioning limit device provided in an embodiment of the present application;

[0025] Figure 4 Schematic diagram of the cross-sectional structure of a fixed bracket in a prestressed adjustable suspended tensioning limit device provided in an embodiment of the present application;

[0026] Figure 5 1 is a top view schematic diagram of a limiting pressure plate in a prestressed adjustable suspended tensioning limiting device provided in an embodiment of the present application;

[0027] Figure 6 1 is a side view schematic diagram of a limiting pressure plate in a prestressed adjustable suspended tensioning limiting device provided in an embodiment of the present application;

[0028] Figure 7 Schematic diagram of the cross-sectional structure of the rotating member in the prestressed adjustable suspended tensioning limiter provided in an embodiment of the present application;

[0029] Figure 8 yes Figure 2 Enlarged view of point B in the middle;

[0030] Figure 9 This is a schematic diagram of the use of the prestressed adjustable suspended tensioning limit device provided in an embodiment of the present application.

[0031] The meanings of the marks in the figure are:

[0032] 91-first anchor plate, 92-first clip, 93-second anchor plate, 94-second clip, 95-tapered hole, 96-jack, 99-prestressed tendon, 990-steel strand;

[0033] 100-Prestressed adjustable suspended tensioning limit device;

[0034] 1-fixed bracket, 10-axial space, 11-first axial end surface, 12-second axial end surface, 13-guide hole, 14-support foot;

[0035] 2-limiting pressure plate, 21-pressure plate body, 210-through hole, 22-ear plate, 220-external threaded portion;

[0036] 3-rotating member, 31-internal thread portion, 32-external gear portion;

[0037] 4-drive assembly, 41-drive member, 42-worm;

[0038] 51-first limiting block, 52-second limiting block;

[0039] 6-locking piece;

[0040] X-first direction, Y-second direction. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0042] It should be noted that when a component is referred to as being "fixed on" or "set on" another component, it may be fixed or set on the other component directly or indirectly. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of description and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this patent. The terms "first" and "second" are only used for the convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0043] In order to illustrate the technical solution described in this application, the following is a detailed description with reference to specific drawings and embodiments.

[0044] See also Figure 1 and Figure 9 As shown, an embodiment of the present application provides a prestressed adjustable suspended tensioning limit device 100, which is used in engineering construction to provide an adjustable limit pressure plate 2 when tensioning a prestressed bundle 99 (the prestressed bundle 99 includes multiple stress ropes, such as a steel strand 990), to prevent the clip (specifically the first clip 92) from being buried in the tapered hole 96 and clamping the steel strand 990 due to the limit height being too low during multiple tensioning, and the clip damaging the steel strand 990 when the steel strand 990 extends outward, or during a friction test, the clip limit height is too low, and the clip retracts and clamps the steel strand 990 when tensioning at the other end, making it impossible to measure the force on the steel strand 990.

[0045] Specifically, see Figure 2 As shown, the prestressed adjustable suspension tensioning limiting device 100 includes a fixed bracket 1, a limiting pressure plate 2 and a rotating member 3; Figure 2 and Figure 4 As shown, the fixing bracket 1 is used to be fixedly installed in the working position to keep it fixed. The fixing bracket 1 is provided with an axial space 10 running through its opposite ends along the first direction X. Figure 3 and Figure 6 As shown, the limiting pressure plate 2 includes a pressure plate body 21 and an external threaded portion 220 connected to the pressure plate body 21. The pressure plate body 21 is slidably disposed in the axial space 10 along the first direction X. Figure 7 As shown, the rotating member 3 is rotatably mounted on the fixed bracket 1 and sleeved on the external threaded portion 220. The rotating member 3 includes an internal threaded portion 31 that engages with the external threaded portion 220. The rotational axis of the rotating member 3 is parallel to the first direction X. The rotating member 3 is limited in the first direction X, and the limiting pressure plate 2 is limited in the rotational direction of the rotating member 3.

[0046] The prestressed adjustable suspended tensioning limiter 100 provided in the embodiment of the present application works as follows:

[0047] A certain force is applied to rotate the rotating member 3 , causing the internal threaded portion 31 of the rotating member 3 to engage with the external threaded portion 220 of the limiting pressure plate 2 . Since the rotating member 3 is limited in the first direction X, the limiting pressure plate 2 is also limited in the rotational direction of the rotating member 3 . Therefore, the limiting pressure plate 2 can only move along the first direction X and cannot rotate relative to the fixed bracket 1 . The rotating member 3 can only rotate relative to the fixed bracket 1 and cannot move along the first direction X. In this way, the rotation of the rotating member 3 can be converted into translation of the limiting pressure plate 2 along the first direction X.

[0048] When the limiting pressure plate 2 cooperates with the steel strand 990 , a certain prestress can be applied to the steel strand 990 as the limiting pressure plate 2 moves.

[0049] The prestressed adjustable suspended tensioning limit device 100 provided in the embodiment of the present application drives the limit pressure plate 2 to move along the first direction X by rotating the rotating part 3. It does not require multiple lifting and adjusting structures, and there is no need to operate the multiple lifting and adjusting structures one by one. It can ensure that the limit pressure plate 2 moves synchronously as a whole along the first direction X, and the problem of inconsistent prestress on the prestressed bundle 99 caused by local deflection of the limit pressure plate 2 will not occur; the overall rotation operation of the rotating part 3 can save time and improve the efficiency of the tensioning operation.

[0050] When the driving member 41 rotates in the forward direction, it can drive the limiting pressure plate 2 to translate in the forward direction. When the driving member 41 rotates in the reverse direction, it can drive the limiting pressure plate 2 to translate in the reverse direction. Therefore, the prestressed adjustable suspended tensioning limiting device 100 provided in the embodiment of the present application can achieve reciprocating adjustment of the position of the limiting pressure plate 2 by rotating the driving member 41 in different directions. It is suitable for use in situations where the prestressed bundle 99 needs to be tensioned multiple times or repeatedly.

[0051] In addition, when the rotating member 3 rotates one circle, the translation distance of the limiting pressure plate 2 along the first direction X is equal to the pitch of its external thread portion 220. The prestressed adjustable suspended tensioning limiting device 100 provided in this application also improves the translation control accuracy of the limiting pressure plate 2.

[0052] For one example, see Figure 3 and Figure 4 As shown, the fixing bracket 1 is further provided with a plurality of guide holes 13, which extend along a first direction X and pass through the inner and outer peripheral walls of the fixing bracket 1 along a second direction Y. The second direction Y is perpendicular to the first direction X. Figure 5 and Figure 6 As shown, the limiting pressure plate 2 further includes a plurality of lugs 22 distributed around the periphery of the pressure plate body 21. Each lug 22 protrudes relative to the pressure plate body 21 in the second direction Y. Each lug 22 is slidably disposed within the guide hole 13 along the first direction X. The lugs 22 are provided with external threads 220. In the second direction Y, each lug 22 protrudes relative to the outer peripheral wall of the fixed bracket 1, thereby enabling the rotating member 3 to be sleeved on the fixed bracket 1.

[0053] This arrangement aims to limit the position of the limiting pressure plate 2 relative to the fixed bracket 1 in the rotational direction of the rotating member 3 by restricting the guide hole 13 with the ear plate 22, thereby reducing the need for a limiting structure. Furthermore, the ear plate 22 can maintain at least partial overlap and alignment with the pressure plate body 21 in the first direction X, thereby reducing the size of the limiting pressure plate 2 in the first direction X and making the overall size of the prestressed adjustable suspended tensioning limiting device 100 smaller.

[0054] It should be noted that to ensure the fit between the internal threaded portion 31 of the rotating member 3 and the external threaded portion 220 of the limiting pressure plate 2, the common points of the external threaded portions 220 of the multiple lugs 22 must be located on the same circumference. However, the lengths of the multiple lugs 22 along the first direction X can be equal or unequal, the pressure plate body 21 can be circular or non-circular, and the cross-section of the axial space 10 can be circular or non-circular, as long as the shape of the pressure plate body 21 matches the cross-sectional shape of the axial space 10.

[0055] In one embodiment, the pressing plate body 21 is circular, and the cross section of the axial space 10 is circular. The lengths of the plurality of lugs 22 along the first direction X are equal. This helps ensure that the strength of the lugs 22 is uniform during processing.

[0056] Optionally, a plurality of lugs 22 are evenly distributed along the periphery of the pressure plate body 21. In this case, the limiting pressure plate 2 is a rotationally symmetrical structure as a whole.

[0057] The first direction X is the axial direction of the fixing bracket 1 , and the second direction Y is the radial direction of the fixing bracket 1 . The rotation center axis of the rotating member 3 may coincide with the center axis of the fixing bracket 1 .

[0058] The number of the lugs 22 is not limited. The number of the lugs 22 is preferably set to ensure that the rotating member 3 can form a stable engagement with the external threaded portion 220. Specifically, in some embodiments, the number of the lugs 22 can be three or four (see Figure 1 and Figure 5 shown), five, six, etc.

[0059] See also Figure 5 As shown, the pressing plate body 21 is provided with a plurality of through holes 210 along the first direction X. The inner dimensions of the through holes 210 are set to be smaller than the outer dimensions of the steel strands 990 to allow the steel strands 990 to slide in the through holes 210 .

[0060] Please refer to Figure 5 and Figure 6 As shown, the thickness of the pressure plate body 21 along the first direction X is less than the height of the lug plate 22 in the first direction X. This configuration is intended to minimize the thickness of the pressure plate body 21 while ensuring that it does not deform due to prestressing, thereby reducing its weight and material costs. The greater height of the lug plate 22 along the first direction X also facilitates the production of a sufficient number of precisely defined external threads 220 to meet the requirements for meshing with the internal thread 31 of the rotating member 3, thereby preventing the lug plate 22 from skewing relative to the first direction X.

[0061] See also Figure 3 and Figure 4As shown, the guide hole 13 extends along the first direction X, and its size along the first direction X is smaller than that of the fixing bracket 1 .

[0062] In one embodiment, to facilitate the processing and manufacturing of the guide hole 13 and to facilitate the insertion of the lug plate 22 into the guide hole 13, the guide hole 13 extends to one axial end surface of the fixing bracket 1. That is, in the first direction X, the guide hole 13 is a hole with one end open, and in the second direction Y, the guide hole 13 is a through hole 210.

[0063] In the circumferential direction of the fixing bracket 1, two parts divided by a guide hole 13 constitute the support legs 14. In other words, the guide hole 13 is defined by the spacing between the support legs 14.

[0064] In practical applications, the guide hole 13 can also be used as an observation window for staff to observe and grasp the height of the limiting pressure plate 2 in real time.

[0065] See also Figure 7 As shown, in one embodiment, an external gear portion 32 is provided on the outer circumference of the rotating member 3. The prestressed adjustable suspended tensioning limiter 100 further includes a drive assembly 4, which includes a worm 42. The worm 42 is rotatably mounted on the fixed bracket 1 and meshes with the external gear portion 32. In this case, the rotating member 3 is a worm gear.

[0066] In this way, the worm 42 is driven to rotate, and the cooperation between the worm 42 and the rotating member 3 can drive the rotating member 3 to rotate.

[0067] Furthermore, the coordination of the worm gear 42 and the worm gear 42 enables a relatively large transmission ratio. Firstly, it saves effort, as a relatively small torque can be inputted into the worm gear 42, generating a relatively large torque on the rotating member 3 to drive the movement of the limit pressure plate 2. Secondly, it allows for the slow and precise control of the movement of the limit pressure plate 2, preventing damage to the structure caused by rapid movement or excessive displacement of the limit pressure plate 2. Thirdly, the coordination of the worm gear and the worm gear 42 enables self-locking, keeping the limit pressure plate 2 stably in place, which helps maintain stable prestress during the tensioning and testing processes.

[0068] In one embodiment, the worm 42 may be driven automatically.

[0069] like Figure 2 and Figure 3 As shown, in one embodiment, the driving assembly 4 further includes a power member, which is provided on the fixed bracket 1 and is used to drive the worm 42 to rotate. The power member can be a motor.

[0070] In this way, by controlling the forward rotation, reverse rotation or stop of the motor through current, the position limiting pressing plate 2 can be moved in the forward direction, moved in the reverse direction or kept at a certain position.

[0071] In one embodiment, the worm 42 may be driven manually.

[0072] In other words, the aforementioned power member is eliminated. When the rotating member 3 needs to rotate, a handheld tool is used to rotate the worm 42. The tool can be a wrench, such as a manual wrench or an electric wrench. This tool does not need to be fixed to the fixed bracket 1 like the power member, but can be connected to or removed from the worm 42 at any time.

[0073] Alternatively, the manual drive of the worm 42 is achieved in the following manner:

[0074] The outer circumference of the rotating member 3 is provided with a plurality of force-applying portions (not shown), which may include force-applying rods. Because the force-applying rods protrude relative to the outer circumference of the rotating member 3 in the second direction Y, they function as force-applying handles. By holding the force-applying handles, an operator applies a tangential force to the rotating member 3, causing the rotating member 3 to rotate.

[0075] The force rod may be fixedly connected to the outer circumference of the rotating member 3. For example, the force rod may be integrally manufactured on the rotating member 3, or may be manufactured separately from the rotating member 3 and connected to the rotating member 3 by welding or the like.

[0076] Alternatively, the force applying rod may be detachably provided on the rotating member 3. For example, a plurality of grooves are provided on the outer circumference of the rotating member 3, and the force applying rod is detachably inserted into each groove.

[0077] The purpose of such a configuration is to facilitate the separate processing and manufacturing of the force application rod and the rotating member 3, and to allow the force application rod to be disassembled and stored when it is no longer needed.

[0078] It will be appreciated that in some embodiments, to ensure that the rotating member 3 remains in the desired position for a certain period of time, a limiting structure may be provided to prevent the rotating member 3 from returning to its original position. The limiting structure may take any form, as long as it can circumferentially limit the position of the rotating member 3. For example, the limiting structure may be removably connected to the force application rod and secure the force application rod; alternatively, the limiting structure may be removably connected to the rotating member 3 and secure the rotating member 3.

[0079] For one example, see Figure 2 and Figure 8As shown, the height of the rotating member 3 in the first direction X is less than the height of the lug plate 22 in the first direction X. This arrangement is intended to allow the external gear portion 32 of the rotating member 3 to mesh with the worm 42. Therefore, the height of the rotating member 3 in the first direction X can be roughly equal to the diameter of the worm 42. Furthermore, the lug plate 22 has a greater height in the first direction X, which facilitates the production of a sufficient number of precisely defined external threads 220 to meet meshing requirements with the internal thread portion 31 of the rotating member 3, thus avoiding the problem of the lug plate 22 skewing relative to the first direction X.

[0080] Next, see Figure 2 and Figure 8 As shown, the outer wall of the fixed bracket 1 is provided with a first stopper 51 and a second stopper 52 spaced apart along a first direction X. The rotating member 3 is positioned between the first stopper 51 and the second stopper 52 and rotates. The provision of the first stopper 51 and the second stopper 52 ensures that the rotating member 3 does not move in the first direction X and can only rotate.

[0081] Multiple first limit blocks 51 and second limit blocks 52 can be provided. Multiple first limit blocks 51 are spaced apart and distributed around the circumference of the fixed bracket 1, and can be evenly distributed. Multiple second limit blocks 52 are spaced apart and distributed around the circumference of the fixed bracket 1, and can be evenly distributed. Optionally, one first limit block 51 and one second limit block 52 are arranged as a group, aligned and spaced along the first direction X, see Figure 8 shown.

[0082] In one embodiment, in order to facilitate the installation and removal of the rotating member 3 on the fixed bracket 1, at least one of the first limit block 51 and the second limit block 52 is detachably installed so that the rotating member 3 can be installed and removed from one axial end of the fixed bracket 1.

[0083] like Figure 4 As shown, the fixing bracket 1 has two axial end faces arranged along the first direction X, which are defined as the first axial end face 11 and the second axial end face 12. Optionally, the guide hole 13 extends to one of the axial end faces of the fixing bracket 1, for example, the first axial end face 11. For details, please refer to Figure 4 shown.

[0084] In one embodiment, please refer to Figure 8 As shown, at least the second limiting block 52 disposed near the first axial end face 11 is detachable. In this way, the rotating member 3 and the limiting pressure plate 2 are both installed and removed from the first axial end face 11 side.

[0085] Specifically, see Figure 8As shown, in an optional embodiment, the second limit block 52 close to the first axial end face 11 is detachably connected to the fixing bracket 1 through a locking member 6, and the locking member 6 can specifically be a bolt, a buckle, etc.

[0086] The first limiting block 51 away from the first axial end face 11 can be fixedly connected to the fixing bracket 1, such as by welding or integrally manufactured, or can be detachably connected to the fixing bracket 1 via, for example, a locking member 6.

[0087] Alternatively, in one embodiment, at least the first limiting block 51 away from the first axial end face 11 is configured to be detachable to allow the rotating member 3 to be detached from the second axial end face 12 . This is also possible.

[0088] See also Figure 9 As shown, the prestressed adjustable suspended tensioning limit device 100 provided in the embodiment of the present application can work in the following manner.

[0089] The first direction X is taken as an example to be described as a vertical direction.

[0090] The first one: Friction coefficient test of prestressed tendon 99.

[0091] See also Figure 9 As shown, the first anchor plate 91 is fixedly arranged, such as being fixed to a concrete member. The fixing bracket 1 is fixedly installed in a predetermined working position, with the first anchor plate 91 located at its lower end. A plurality of steel strands 990 pass through the first anchor plate 91. On the side of the first anchor plate 91 near the fixing bracket 1, a first clip 92 is also provided on the steel strands 990. The first clip 92 is configured to be able to move on the steel strands 990 toward the first anchor plate 91, but not to move in the opposite direction. The first clip 92 is wedge-shaped and gradually tapers toward the first anchor plate 91. The first anchor plate 91 is provided with a corresponding tapered hole 95, and the size of the first clip 92 is larger than the size of each through hole 210 in the pressure plate body 21. At the upper end of the fixed bracket 1, a lifting drive mechanism, such as a jack 96, is fixedly provided. The output end of the jack 96 is fixedly connected to the second anchor plate 93. The steel strand 990 passes through the second anchor plate 93 at the same time, and on the side of the second anchor plate 93 facing away from the fixed bracket 1, a second clip 94 is provided on the steel strand 990. The configuration of the second clip 94 is the same as that of the first clip 92.

[0092] When testing the coefficient of friction between the prestressed strand 99 and the hole wall, the jack 96 lifts the second anchor plate 93 upward. Due to the limiting effect of the second clamp 94 and the second anchor plate 93, the steel strand 990 is driven upward. At this time, the limiting pressure plate 2 abuts against the top of the first clamp 92. By adjusting the height of the limiting pressure plate 2 in the first direction X, a suspended state is achieved between the first clamp 92 and the first anchor plate 91.

[0093] At the other end of steel strand 990, a similar prestressed, adjustable suspended tensioning and limiting device 100, along with a first anchor plate 91, a second anchor plate 93, a first clamp 92, a second clamp 94, and a jack 96, is installed. The difference in pressure readings on the two jacks 96 represents the difference in tension at each end of steel strand 990. This difference in tension is the friction between steel strand 990 and the hole wall. This provides the coefficient of friction between prestressed strand 99 and the hole wall.

[0094] The second type: tensioning of prestressed tendon 99.

[0095] Adjust the height of the limiting pressure plate 2 in the first direction X so that the distance between the pressure plate body 21 and the first anchor plate 91 is as close as possible to (and can be slightly larger than) the height difference between the tapered hole 95 and the first clip 92. Activate the jack 96 to lift the second anchor plate 93 upward. Due to the setting of the second clip 94, the steel strand 990 is pulled upward. At the same time, due to the restriction of the limiting pressure plate 2 on the first clip 92, the first clip 92 remains in a position close to the first anchor plate 91. The steel strand 990 passes through the first anchor plate 91 and is pulled upward. The first clip 92 unidirectionally restricts the steel strand 990 from returning downward. In this way, the portion of the steel strand 990 located below the first anchor plate 91 is tensioned. After removing the jack 96, the predetermined prestress can be obtained on the steel strand 990.

[0096] The prestressed adjustable suspended tensioning limiter 100 provided in the embodiment of the present application has the following advantages:

[0097] 1. The rotation of the rotating member 3 is converted into the translation of the limiting pressure plate 2 along the first direction X, which can achieve the parallelism of the limiting pressure plate 2 as a whole relative to the anchor plates (the first anchor plate 91 and the second anchor plate 93). In addition, the clamping pieces (the first clamping piece 92 and the second clamping piece 94) are evenly stressed and move synchronously, which is conducive to ensuring the accuracy of the prestressing and the consistency of the prestress on different steel strands 990.

[0098] 2. The worm wheel and the worm 42 cooperate to enable the limit pressure plate 2 to stop at any position and remain suspended, thereby preventing the limit pressure plate 2 from moving due to its own gravity or other factors, thereby avoiding affecting the prestress;

[0099] 3. The combination of the worm wheel and the worm 42 can reduce the input force during tensioning and accurately control the moving speed and distance of the limit pressure plate 2;

[0100] 4. The translation of the limit pressure plate 2 can be achieved by simply operating the rotating member 3, which is simple to operate, low in strength and high in efficiency.

[0101] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A prestressed adjustable suspended tensioning limit device, characterized in that: include: A fixed bracket, wherein the fixed bracket is provided with an axial space extending through two opposite ends thereof along a first direction, A limiting pressure plate, comprising a pressure plate body and an external threaded portion connected to each other, wherein the pressure plate body is slidably disposed in the axial space along a first direction; The rotating member is rotatably mounted on the fixed bracket, and the rotating member is provided with an internal thread portion meshing with the external thread portion.

2. The prestressed adjustable suspended tensioning limit device according to claim 1, characterized in that: The rotating member further includes an external gear portion, and the prestressed adjustable suspension tensioning limit device further includes a driving assembly, wherein the driving assembly includes a worm, and the worm is rotatably mounted on the fixed bracket and meshes with the external gear portion.

3. The prestressed adjustable suspended tensioning limiter according to claim 2, characterized in that: The driving assembly also includes a power piece, which is arranged on the fixed bracket and is used to drive the worm to rotate.

4. The prestressed adjustable suspended tensioning limiter according to claim 1, characterized in that: A plurality of force-applying parts are arranged on the outer circumference of the rotating member, and the force-applying parts include force-applying rods, which are fixedly connected to the outer circumference of the rotating member, or the force-applying rods are detachably inserted into grooves on the outer circumference of the rotating member.

5. The prestressed adjustable suspended tensioning limiter according to any one of claims 1 to 4, characterized in that: The fixing bracket is also provided with a plurality of guide holes, the guide holes extending along the first direction and penetrating the inner peripheral wall and the outer peripheral wall of the fixing bracket along the second direction; the second direction is perpendicular to the first direction; The limiting pressure plate also includes a plurality of ear plates connected to the periphery of the pressure plate body, the ear plates are provided with the external threaded portion, and each of the ear plates is slidably arranged in the guide hole along the first direction; the rotating member is sleeved with the fixed bracket.

6. The prestressed adjustable suspended tensioning limit device according to claim 5, characterized in that: The guide hole is opened from the first axial end surface of the fixing bracket.

7. The prestressed adjustable suspended tensioning limiter according to claim 6, characterized in that: The guide hole is opened from the first axial end face of the fixed bracket; a first limit block and a second limit block are provided on the outer wall of the fixed bracket, the first limit block and the second limit block are arranged at intervals along the first direction, and the rotating member is located at the first limit block and the second limit block; the second limit block is opened close to the first axial end face, and at least the second limit block is detachably installed.

8. The prestressed adjustable suspended tensioning limiter according to claim 5, characterized in that: A first limit block and a second limit block are provided on the outer wall of the fixed bracket, the first limit block and the second limit block are arranged at intervals along the first direction, and the rotating member is located at the first limit block and the second limit block; at least one of the first limit block and the second limit block is detachable.

9. The prestressed adjustable suspended tensioning limiter according to claim 6, characterized in that: The height of the ear plate along the first direction is greater than the thickness of the pressing plate body along the first direction.

10. The prestressed adjustable suspended tensioning limiter according to claim 6, characterized in that: A height of the ear plate along the first direction is greater than a height of the rotating member along the first direction.

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