Bridge external prestressing tendon supplementary tensioning device and working method

Abstract

The invention provides a bridge external prestressing tendon supplementary tensioning device and a working method, relates to the field of bridges, and aims to solve the problems that an existing bridge external prestressing supplementary tensioning device is poor in stability and prone to toppling and losing efficacy due to stress deviation. The auxiliary sliding block is matched with a rack sliding guide rail to form a sliding pair, the main sliding block and the auxiliary sliding block are fixedly connected through a connecting column, the main sliding block, the auxiliary sliding block and the connecting column can move together in the moving process, meanwhile, a transmission rod is rotationally arranged in the connecting column, the main sliding block serves as a main driving end, and the auxiliary sliding block serves as an auxiliary driving end. The connecting column is jointly driven to move horizontally from the two ends of the connecting column, the connecting column conducts supplementary tensioning on the prestressing tendon, the main sliding block and the auxiliary sliding block form a multi-point supporting structure for the connecting column, the contact position of the prestressing tendon and the connecting column is located between the main sliding block and the auxiliary sliding block all the time, and the risk caused by stress deviation is reduced.

Description

Technical Field

[0001] The present invention relates to the field of bridges, and particularly to a supplementary tensioning device and working method for external prestressed tendons of bridges. Background Art

[0002] By tensioning external prestressed tendons, the bearing capacity and stiffness of the structure can be improved, and the mechanical properties of the structure can be improved. The relaxation of the prestressed tendons causes the tensile stress of the prestressed tendons to gradually decrease over time, resulting in a reduction in the effective prestress transferred from the prestressed tendons to the structure, thereby reducing the ability of the structure to resist external loads and increasing the deformation of the structure, affecting its normal service performance. By performing supplementary tensioning on the external prestressed tendons, the tension of the external prestressed tendons can be increased, the prestress loss can be compensated, and the beam body can be in a more favorable compression state.

[0003] Chinese Patent (Publication No. CN115288042A, Publication Date: November 4, 2022) discloses a reinforcement device and construction method for precise supplementary tensioning of external prestress. An external prestress supplementary tensioning and reinforcement device is provided that is long-term installed on a prestressed concrete beam. Through the combination of a worm and worm gear and a stress control component, the distance between the prestressed tendon and the bottom of the concrete beam can be precisely controlled. A worm is slidably sleeved outside a round rod, so that the worm can drive a duct component below through which the prestressed tendon passes to move, realizing the tensioning of the prestressed tendon. The duct component can provide a vertical thrust, but in the horizontal direction perpendicular to the vertical plane where the prestressed tendon is located, the duct component cannot be adaptively adjusted, resulting in poor stability along the horizontal direction perpendicular to the fixed concrete beam. When the prestressed tendon is offset in the horizontal direction perpendicular to the concrete beam, it will cause the inclination and failure of the supplementary tensioning structure. Therefore, the installation accuracy requirements for the entire reinforcement device are relatively high, resulting in poor adaptability. Moreover, if the number of duct components of the reinforcement device for precise supplementary tensioning of external prestress is increased, the duct components will expand along the direction perpendicular to the concrete beam, and the situation where the positions of some duct components are not collinear with the sliding direction of the worm will occur, forming a cantilever structure. When pushing the duct component to move and tension the prestressed tendon, there will still be an offset, resulting in the inclined stress of the supplementary tensioning structure and increasing the risk of tipping and failure. Summary of the Invention

[0004] The purpose of the present invention is to address the defects existing in the prior art and provide a supplementary tensioning device and working method for external prestressed tendons of bridges. The main slider and the guide rail screw cooperate to form a screw slider mechanism, and the secondary slider and the sliding guide rail of the frame cooperate to form a sliding pair. The main slider and the secondary slider are fixedly connected by a connecting column. When moving, the main slider, the secondary slider, and the connecting column can move together. The outer circumference of the connecting column can provide a larger abutting range in the axial direction, thereby expanding the working range of the driving part for abutting the prestressed tendon, improving the adaptability to the prestressed tendon, and ensuring the stability during the supplementary tensioning process.

[0005] The first object of the present invention is to provide a device for supplementary tensioning of external prestressed tendons of a bridge, adopting the following scheme: It includes a frame and a movable component. The movable component includes a main slider, a force transmission rod group, and a secondary slider. The main slider is combined with a guide rail screw to form a screw slider mechanism. The guide rail screw is rotatably installed on the frame. The secondary slider is combined and installed on the sliding guide rail of the frame to form a sliding pair. The force transmission rod group includes a connecting column and a transmission rod rotatably installed inside the connecting column. The main slider and the secondary slider are fixedly connected through the connecting column. Both ends of the transmission rod are respectively meshed with racks parallel to the guide rail screw through gears. The gears at both ends of the transmission rod rotate synchronously, so that the secondary slider and the main slider move synchronously in translation. A driving part for abutting against the prestressed tendon is formed outside the connecting column. The guide rail screw can receive the action of a power source and rotate.

[0006] Further, secondary sliders are respectively connected to both sides of the main slider through the force transmission rod group. Each secondary slider is respectively slidably matched with a sliding guide rail, and driving parts are respectively formed on both sides of the main slider.

[0007] Further, the force transmission rod groups on both sides of the main slider share the same transmission rod. The transmission rod penetrates through the main slider, so that the main slider and the secondary sliders on both sides of the main slider move synchronously along the axial direction of the guide rail screw.

[0008] Further, the transmission rod is respectively rotatably connected to the main slider and the secondary slider. The end of the transmission rod close to the secondary slider is an active gear, and the active gear is meshed with a driven rack through a transmission gear installed on the secondary slider.

[0009] Further, a worm and worm gear mechanism is combined with the power input end of the guide rail screw. The worm gear is combined with the guide rail screw. The worm is installed on the frame through a support, and one end of the worm receives the action of a power source.

[0010] Further, two guide rail screws are combined with the main slider. The two guide rail screws rotate at the same speed and synchronously. The gear at the end of the transmission rod close to the main slider is a driving gear. The driving gear is meshed with a driving rack. The driving gear and the driving rack are located between the two guide rail screws. The driving rack penetrates through the main slider.

[0011] Further, the force transmission rod group further includes a rotary sleeve. The rotary sleeve is rotatably sleeved outside the connecting column and is used for contacting the prestressed tendon. Limiting rings protruding from the outer circumferential surface of the rotary sleeve are respectively provided at both ends of the rotary sleeve.

[0012] Further, the secondary slider forms a chute with a T-shaped cross section. The chute is matched with the sliding guide rail. The gear at the end of the transmission rod close to the secondary slider and the meshed rack are located inside the chute.

[0013] The second object of the present invention is to provide a working method of the device for supplementary tensioning of external prestressed tendons of a bridge as described in the first object, including: Fix the external prestressed tendon supplementary tensioning device of the bridge to the bridge through the frame. Both ends of the prestressed tendon are fixed to the bridge, and the middle section abuts against the outside of the connecting column. The guide rail screw rod rotates under the action of the power source and drives the main slider to translate axially along the guide rail screw rod. On the one hand, the main slider drives the secondary slider to translate through the connecting column. On the other hand, when the main slider drives the transmission rod to translate, the gear connected to the end of the transmission rod close to the main slider meshes with the rack, so that the transmission rod also rotates when translating, thereby transmitting the torque to the gear at the end of the transmission rod close to the secondary slider. This end gear meshes with the rack for transmission to drive the secondary slider; make the secondary slider move along the sliding guide rail, so that the main slider, secondary slider and connecting column move synchronously. The force transmission rod group moves axially along the guide rail screw rod, thereby driving the prestressed tendon to achieve supplementary tensioning and strengthening the bridge.

[0014] Furthermore, arrange multiple external prestressed tendon supplementary tensioning devices of the bridge on the bridge. The prestressed tendons sequentially abut against the driving parts of multiple external prestressed tendon supplementary tensioning devices of the bridge, and adjust the external prestressed tendon supplementary tensioning devices of the bridge respectively to perform supplementary tensioning on the prestressed tendons.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are: Aiming at the problems of poor stability and easy tipping failure due to force offset existing in the current external prestressed supplementary tensioning and strengthening device of the bridge, the main slider and the guide rail screw rod are combined into a screw slider mechanism, and the secondary slider and the sliding guide rail of the frame are combined into a sliding pair. The main slider and the secondary slider are fixedly connected by a connecting column. When moving, the main slider, secondary slider and connecting column can move together. The outer circumference of the connecting column can provide a larger abutting range axially, thereby expanding the working range of the driving part abutting against the prestressed tendon and improving the adaptability to the prestressed tendon; at the same time, a transmission rod is rotatably arranged inside the connecting column. The main slider is the main driving end, and the transmission rod can rotate following the translation of the connecting column. After the gear at the end of the transmission rod close to the main slider meshes with the rack, the transmission rod transmits the torque to the other end close to the secondary slider, so that the gear at the secondary slider moves along the rack, applying a translational driving force to the secondary slider as the secondary driving end, and driving the connecting column to translate together from both ends of the connecting column, so that the connecting column performs supplementary tensioning on the prestressed tendon. The main slider and the secondary slider form a multi-point support structure for the connecting column. The contact position between the prestressed tendon and the connecting column is always located between the main slider and the secondary slider, reducing the risk brought by force offset. Compared with the single-sided cantilever driving mechanism, the risk of bending due to asynchronous movement of the two ends of the connecting column caused by uneven force is reduced; the driving part outside the connecting column can stably abut against the prestressed tendon, and its range is large enough to adapt to prestressed tendons at different positions, ensuring the accuracy of supplementary tensioning, reducing the requirement for installation accuracy. When the prestressed tendon has a horizontal offset perpendicular to the axis of the fixed beam, the prestressed tendon can still be within the abutting range of the driving part and maintain a good working state.

[0016] Starting from the transmission of force and the coordinated movement of the structure, through the design of gear-rack transmission and synchronous translation of the main and auxiliary sliders, it ensures the uniform distribution of force during the supplementary tensioning process, enhancing the device's ability to resist deviation; the setting of the connecting column driving part guarantees stable contact with the prestressed tendon, further improving the accuracy and stability of the supplementary tensioning, enabling the supplementary tensioning device to work stably under complex working conditions and reducing the dependence on installation accuracy.

[0017] Both sides of the main slider are respectively connected to the auxiliary slider through a force transmission rod group, and driving parts are respectively formed on both sides of the main slider. At the same time, the force transmission rod groups on both sides of the main slider share the same transmission rod, enabling the main slider and the auxiliary sliders on both sides to move synchronously along the axial direction of the guide rail screw. It can simultaneously tension two prestressed tendons, which conforms to the layout of the actual bridge when using external prestressing for reinforcement. The symmetric multi-slider coordinated structure enables the two prestressed tendons to be tensioned under the action of two driving parts. The forces on both sides of the main slider are relatively balanced, avoiding deviation caused by unilateral force on the main slider, and further enhancing the stability of the supplementary tensioning device during the working process.

[0018] The auxiliary slider forms a T-shaped cross-section chute. The chute cooperates with the sliding guide rail. The gear at the end of the transmission rod close to the auxiliary slider and the engaged rack are located in the chute, integrating the transmission components into the internal space of the auxiliary slider. On the one hand, it reduces the influence of external interference on the transmission system and improves the reliability of the transmission; on the other hand, the cooperation between the T-shaped chute and the sliding guide rail restricts the movement of the auxiliary slider in the direction non-parallel to the axial direction of the sliding guide rail, enabling the auxiliary slider to only translate along the predetermined sliding guide rail direction, ensuring the accuracy of the force transmission direction and enhancing the overall stability of the device.

[0019] The power input end of the guide rail screw cooperates with a worm and worm gear mechanism. The worm and worm gear mechanism has a self-locking characteristic, which can keep the guide rail screw in a fixed state after the supplementary tensioning is completed, preventing the transmission rod from reversing due to external forces after the tensioning is completed, and jointly maintaining the stability of the device after the supplementary tensioning is completed.

[0020] The rotating sleeve in the force transmission rod group is rotatably sleeved outside the connecting column for contacting the prestressed tendon, and raised limiting rings are provided at both ends of the rotating sleeve. The rotating sleeve enables the friction form between the prestressed tendon and the device to change from sliding friction to rolling friction during the supplementary tensioning process, greatly reducing the frictional force, reducing the wear on the surface of the prestressed tendon, and protecting the performance of the prestressed tendon; the limiting rings at both ends can prevent the prestressed tendon from undergoing lateral deviation during the tensioning process, ensuring that the prestressed tendon is always in the correct stress position, and improving the accuracy and effectiveness of the supplementary tensioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The schematic drawings forming a part of this invention are used to provide a further understanding of this invention. The schematic embodiments of this invention and their descriptions are used to explain this invention and do not constitute an improper limitation of this invention.

[0022] Figure 1 Schematic diagram of the supplementary tensioning device for external prestressed tendons of bridges in one or more embodiments of the present invention.

[0023] Figure 2 Side view schematic diagram of the supplementary tensioning device for external prestressed tendons of bridges in one or more embodiments of the present invention.

[0024] Figure 3 Schematic diagram of the driving gear meshing with the driven gear in one or more embodiments of the present invention.

[0025] Figure 4 Schematic diagram of the worm and worm gear mechanism in one or more embodiments of the present invention.

[0026] Figure 5 Schematic diagram of the force transmission rod group in one or more embodiments of the present invention.

[0027] Figure 6 Schematic diagram of the layout of the supplementary tensioning device for external prestressed tendons of bridges on the bridge in one or more embodiments of the present invention.

[0028] Wherein, 1. Frame; 101. Anchor bolt; 2. Side support plate; 3. Top plate; 4. Sliding guide rail; 5. Driving rack; 6. Sub-slider; 7. Transmission gear; 8. Driven rack; 9. Force transmission rod group; 901. Connecting column; 902. Transmission rod; 903. Driving gear; 904. Driving gear; 905. Rotary sleeve; 10. Limit ring; 11. Main slider; 12. Guide rail screw; 13. Worm; 14. Worm gear; 15. Support; 16. Bottom plate; 17. Prestressed tendon; 18. Bridge deck; 19. Longitudinal beam. Specific embodiments

[0029] Embodiment 1 In a typical embodiment of the present invention, as Figures 1-6 shown, a supplementary tensioning device for external prestressed tendons of bridges is provided.

[0030] Existing in - vitro prestress precise supplementary tensioning and strengthening devices have problems such as poor stability, high requirements for installation accuracy, and poor adaptability. When expanding the working space by increasing the number of duct components, the length of the duct components in the direction perpendicular to the axis of the installed beam body in the plane will increase, and some duct components will extend outside the sliding position to form cantilevers. When prestressing tendons are inserted into these duct components for supplementary tensioning, it is easy to occur deviation, resulting in problems such as the supplementary tensioning structure being inclined in force or even toppling and failing. Based on this, this embodiment provides a supplementary tensioning device for in - vitro prestressed tendons of bridges, which adopts a structure in which the main slider 11, the connecting column 901, and the secondary slider 6 are connected in sequence. The main slider 11 is matched with the guide rail screw 12 to form a screw - slider mechanism, which serves as the power input position. The connecting column 901 drives the secondary slider 6 to move linearly. At the same time, the internal transmission rod 902 of the connecting column 901 can form rotation by using the gear - rack mechanism during linear movement to drive the secondary slider 6. The main slider 11 and the secondary slider 6 drive the connecting column 901 to move simultaneously from both ends of the connecting column 901. The outer circumference of the connecting column 901 can provide a larger abutting range in the axial direction, thereby expanding the working range of the driving part abutting against the prestressing tendon 17, improving the adaptability to the prestressing tendon 17, and ensuring the stability during the supplementary tensioning process.

[0031] As Figures 1-6 shown, the supplementary tensioning device for in - vitro prestressed tendons of bridges mainly includes a frame 1 and a movable assembly. The movable assembly includes a main slider 11, a force - transmitting rod group 9, and a secondary slider 6.

[0032] The frame 1 serves as the basic support component of the entire supplementary tensioning device, providing an installation and fixing platform for other components. As Figure 1 shown, the frame 1 includes side support plates 2, a top plate 3, and a bottom plate 16. The two side support plates 2 are connected by the top plate 3 and the bottom plate 16 to form a frame structure. The movable assembly is installed inside the frame structure. The top of the side support plates 2 extends outside the top plate 3. Through - holes can be opened in the part extending outside the top plate 3 for cooperating with fasteners such as anchor bolts 101 and expansion bolts to install the frame 1 on the bridge. Welding connections or fasteners can be used between the top plate 3 and the side support plates 2, and between the bottom plate 16 and the side support plates 2.

[0033] As Figure 6 shown, the frame 1 is fixed on the longitudinal beam 19 of the bridge through anchor bolts 101. The distance between the two side support plates 2 of the frame 1 matches the width of the bridge longitudinal beam 19, so that the two side support plates 2 are respectively fixed on both sides of the longitudinal beam 19. The bridge deck 18 is laid on the top of the bridge. By setting a stable frame 1 structure, the stability and structural strength of the entire device are ensured, so that each component can maintain a relatively fixed position during the working process and bear various forces generated during the supplementary tensioning process. It provides a stable support foundation for the device, avoiding the overall shaking or displacement of the device caused by unstable foundation, thus affecting the accuracy and stability of the supplementary tensioning.

[0034] The main slider 11 and the guide rail screw 12 cooperate to form a screw slider mechanism. The guide rail screw 12 is rotatably installed on the frame 1. As Figure 1 shown, both ends of the guide rail screw 12 can be respectively installed on the frame 1 through bearings. The bearings can be tapered roller bearings, thrust ball bearings, etc. The main slider 11 is provided with a threaded hole, and the guide rail screw 12 passes through the threaded hole and forms a threaded fit with the threaded hole. By driving the guide rail screw 12 to rotate around its axis by an external force, the rotational motion is converted into the linear motion of the main slider 11. In other alternative embodiments, a ball screw pair can be formed between the main slider 11 and the guide rail screw 12, and balls are arranged at the mating position of the main slider 11 and the guide rail screw 12, so as to improve the transmission efficiency, reduce the friction coefficient, and improve the motion smoothness. In this embodiment, the axis of the guide rail screw 12 is vertically distributed, and the main slider 11 moves up and down vertically under the drive of the guide rail screw 12, realizing the precise control of the position of the main slider 11, and further driving the entire movable assembly to move to perform the tensioning operation on the prestressed tendon 17.

[0035] During the supplementary tensioning process, the power source drives the guide rail screw 12 to rotate, and the main slider 11 moves smoothly along the axial direction of the guide rail screw 12, which not only provides power for the movement of the main slider 11, but also can guide the movement of the main slider 11. Compared with the traditional driving method, the screw slider mechanism can provide precise displacement control, ensure the accuracy and stability of the movement of the main slider 11, thereby precisely controlling the tension applied to the prestressed tendon 17, improving the accuracy of the supplementary tensioning, and solving the problem that the existing device has poor supplementary tensioning effect due to inaccurate driving.

[0036] The secondary slider 6 is cooperatively installed on the sliding guide rail 4 of the frame 1 to form a sliding pair. The arrangement direction of the sliding guide rail 4 is parallel to the axis of the guide rail screw 12. The secondary slider 6 cooperates with the sliding guide rail 4 to provide auxiliary support and guidance. The sliding guide rail 4 and the guide rail screw 12 jointly provide support and guidance for the movable assembly, ensuring the smoothness and linearity of the movable assembly during the movement process. The secondary slider 6 and the main slider 11 work together to jointly bear the reaction force generated during the tensioning of the prestressed tendon 17.

[0037] During the movement of the main slider 11, the secondary slider 6 slides synchronously along the sliding guide rail 4. Since the outer ring of the connecting column 901 that abuts against the prestressed tendon 17 is located between the main slider 11 and the secondary slider 6, the main slider 11 and the secondary slider 6 support and drive the connecting column 901 from both sides. The prestressed tendon 17 can be abutted along the entire axial length of the connecting column 901 as the driving part. Even if the prestressed tendon 17 has an offset along the axis of the connecting column 901, that is, perpendicular to the transverse direction of the beam on which the frame 1 is installed, it is still within the abutting range of the connecting column 901. Compared with the prior art, the working range is expanded. The two ends of the connecting column 901 are connected to the main slider 11 and the secondary slider 6 to form a multi-point support structure, maintaining the balance of the moving components, avoiding the device from tipping and failing due to changes in the acting position and different acting positions of the prestressed tendon 17, and significantly improving the stability and anti-offset ability of the device.

[0038] The force transmission rod group 9 includes a connecting column 901 and a transmission rod 902 rotatably installed in the connecting column 901. The main slider 11 and the secondary slider 6 are fixedly connected by the connecting column 901, enabling forced synchronous movement between the main slider 11 and the secondary slider 6. Moreover, both ends of the transmission rod 902 are respectively engaged with racks through gears. The racks are parallel to the guide rail screw 12. The gears at both ends of the transmission rod 902 rotate synchronously, so that the gear at the end of the transmission rod 902 close to the secondary slider 6 is driven, and then the secondary slider 6 climbs or descends along the rack, forming a secondary drive. A driving part for abutting against the prestressed tendon 17 is formed on the outside of the connecting column 901. In this embodiment, as Figure 2 and Figure 5 shown, the connecting column 901 is used to abut against the prestressed tendon 17 to realize the tensioning of the prestressed tendon 17. The transmission rod 902 transmits the movement of the main slider 11 to the secondary slider 6 through the meshing of the gear and the rack, enabling the main slider 11 and the secondary slider 6 to move synchronously in translation, ensuring uniform force on both ends of the connecting column 901. The driving part can act on the prestressed tendon 17 to provide sufficient tensile force.

[0039] Specifically, during operation, when the main slider 11 moves, it drives the connecting column 901 and the transmission rod 902 to translate. During the translation process of the transmission rod 902, due to the formation of a gear-rack meshing at the position where it cooperates with the main slider 11, the transmission rod 902 also forms a rotational motion during translation, and then transmits the torque to the gear on the secondary slider 6, causing the gear on the secondary slider 6 to be driven, so that the secondary slider 6 moves synchronously, forming a multi-point support structure for the connecting column 901. The contact position of the prestressed tendon 17 and the connecting column 901 is always located between the main slider 11 and the secondary slider 6. Regardless of how the prestressed tendon 17 horizontally offsets between the main slider 11 and the secondary slider 6, both ends of the connecting column 901 can be evenly stressed, reducing the risk of bending or asynchronous movement of the connecting column 901 caused by uneven stress. At the same time, the large-range driving part outside the connecting column 901 can adapt to the prestressed tendons 17 at different positions, reducing the requirement for installation accuracy. Even if the prestressed tendon 17 has a horizontal offset perpendicular to the beam axis direction, effective abutment and tensioning can still be ensured, improving the adaptability of the device and the accuracy of supplementary tensioning.

[0040] As Figure 2 shown, the two sides of the main slider 11 are respectively connected to the secondary slider 6 through the force transmission rod group 9. Each secondary slider 6 cooperates with the sliding guide rail 4 to form a driving part on both sides of the main slider 11, and the force transmission rod groups 9 on both sides share a transmission rod 902 passing through the main slider 11 to realize the synchronous movement of the main slider 11 and the secondary sliders 6 on both sides along the axial direction of the guide rail screw 12. A symmetric stress system is constructed, enhancing the adaptability of the device to the action of the prestressed tendon 17 at different positions on the connecting column 901, and improving the overall stability and supplementary tensioning effect.

[0041] Compared with single-side drive, the symmetric multi-slider structure can effectively offset the unbalanced force generated by the offset and reduce the risk of device tilt. If the prestressed tendon 17 offsets to one side, the secondary sliders 6 on both sides cooperate with the main slider 11 through synchronous movement, so that the connecting column 901 is always in a stable stress state, ensuring the accuracy and stability of the supplementary tensioning operation and improving the reliability of the device under complex working conditions.

[0042] As Figure 3 and Figure 5As shown in the figure, the transmission rod 902 is respectively rotatably connected to the main slider 11 and the secondary slider 6. Bearings are installed at the rotational connection positions. A driving gear 903 is installed near the main slider 11 on the transmission rod 902. The rack engaged with the driving gear 903 is the driving rack 5. In this embodiment, the driving gear 903 is installed inside the main slider 11. The driving rack 5 is distributed along the direction parallel to the axis of the guide screw 12. When the main slider 11 moves up and down along the guide screw 12, the engagement between the driving gear 903 and the driving rack 5 is maintained. The translational motion of the main slider 11 driving the driving gear 903 is converted into the rotational motion of the driving gear 903. The force transmission rod group 9 shares a transmission rod 902 passing through the main slider 11. The driving gear 903 is installed in the middle of the transmission rod 902. Active gears 904 are installed at the ends of the transmission rod 902 near the secondary slider 6. Active gears 904 are installed at both ends of the transmission rod 902 respectively. The rotational motion of the driving gear 903 is transmitted to the active gears 904 at both ends of the transmission rod 902 through the transmission rod 902. The active gears 904 mesh with a driven rack 8 through transmission gears 7 installed on the secondary slider 6. When the transmission rod 902 drives the active gears 904 at both ends to rotate, the active gears 904 drive the transmission gears 7 to rotate, so that the transmission gears 7 mesh with the driven rack 8 to drive the secondary slider 6 to rise or fall.

[0043] As Figure 3 shown, there are multiple transmission gears 7. One of the transmission gears 7 meshes with both the driven rack 8 and the active gear 904 at the same time, and the other driven gears only mesh with the driven rack 8 for auxiliary guiding.

[0044] Combined Figure 3 with Figure 5 the figure, the transmission rod 902 is rotatably connected to the main slider 11 and the secondary slider 6. The active gear 904 at the secondary slider 6 meshes with the driven rack 8 through the transmission gear 7. Additionally, as Figure 1 shown Figure 4 in the figure, a worm and worm gear mechanism is configured at the power input end of the guide screw 12. The worm wheel 13 cooperates with the guide screw 12 to make the worm wheel 13 and the guide screw 12 rotate coaxially and synchronously. The worm 14 is installed on the machine frame 1 through a support 15. One end of the worm 14 is connected to a power source. The support 15 can adopt a rotating seat. The worm 14 is installed on the support 15 through bearings, etc., and the support 15 is fixed on the machine frame 1. The power source can adopt a motor, a wrench, a hydraulic motor, etc.

[0045] The main slider 11 is fitted with two guide screw rods 12 that rotate at the same speed synchronously. In this embodiment, corresponding worm wheels 13 are installed on each guide screw rod 12, and the same worm 14 is used to drive the two worm wheels 13 synchronously. Utilizing the self-locking characteristic of the worm wheel 13 and worm 14, the rotation of the worm 14 can be transmitted unidirectionally to the worm wheel 13 to make the worm wheel 13 rotate, while the rotation of the worm wheel 13 cannot drive the worm 14 to rotate. The position of the guide screw rod 12 is locked by the worm wheel 13 to achieve the stable retention of the device after supplementary tensioning, and at the same time provide precise power transmission.

[0046] After the supplementary tensioning is completed, the worm and worm wheel mechanism locks automatically to prevent the guide screw rod 12 from rotating due to external force or vibration, ensuring that the position of the main slider 11 is fixed and avoiding accidental changes in the tension of the prestressed tendon 17. Through the self-locking effect of the worm and worm wheel mechanism, it is possible to prevent the prestressed tendon 17 from retracting after the supplementary tensioning is completed, ensuring the stability of the tensioning effect and avoiding prestress losses caused by external force interference. In addition, the transmission ratio characteristic of the worm and worm wheel mechanism can achieve precise control of the guide screw rod 12, making the movement of the main slider 11 smoother and more precise, and further improving the accuracy of the supplementary tensioning.

[0047] The main slider 11 is fitted with two guide screw rods 12 that rotate at the same speed synchronously. The driving gear 903 at one end of the transmission rod 902 close to the main slider 11 meshes with the driving rack 5 located between the two screw rods, and the driving rack 5 penetrates through the main slider 11. The smoothness and driving force of the movement of the main slider 11 are enhanced, and the supplementary tensioning ability of the device for large-load prestressed tendons 17 is improved.

[0048] The two guide screw rods 12 that rotate at the same speed synchronously provide uniform and stable driving force for the main slider 11. Compared with single-screw drive, the double-screw structure can disperse the force, reduce the wear of the screw rod, and extend the service life of the device. At the same time, the layout of the driving gear 903 and the driving rack 5 is optimized to ensure that the main slider 11 is evenly stressed during the movement process, reducing the shaking or deviation caused by uneven stress, making the supplementary tensioning operation more stable and reliable, especially suitable for scenarios with high prestress requirements such as long-span bridges.

[0049] As Figure 3 and Figure 5 shown, the secondary slider 6 is fitted with a T-shaped cross-section chute and a sliding guide rail 4, and the gear and meshing rack at one end of the transmission rod 902 close to the secondary slider 6 are arranged in the chute.

[0050] The cooperation of the T-shaped chute and the sliding guide rail 4 forms multi-directional constraints on the secondary slider 6, restricting its non-axial movement and ensuring that the secondary slider 6 slides smoothly along the predetermined direction. Placing the transmission components in the chute can effectively avoid the influence of external sundries, dust, etc. on the transmission system and improve the transmission reliability. In addition, this layout makes the structure of the secondary slider 6 more compact, enhancing the overall stability and anti-interference ability of the device.

[0051] AsFigure 5 As shown in the figure, a rotary sleeve 905 is added to the force transfer rod group 9. The rotating sleeve contacts the prestressed tendon 17 outside the connecting column 901. The rotary sleeve 905 acts as a driving part to abut against the prestressed tendon 17. Limit rings 10 are arranged at both ends of the rotary sleeve 905 to reduce the friction between the prestressed tendon 17 and the device, protect the surface of the prestressed tendon 17, and prevent the lateral displacement of the prestressed tendon 17 at the same time. During the supplementary tensioning process, the rotary sleeve 905 converts sliding friction into rolling friction, greatly reducing the frictional force, reducing the wear on the surface of the prestressed tendon 17, and prolonging its service life. The limit rings 10 at both ends play a limiting role on the prestressed tendon 17. Even if the prestressed tendon 17 is subjected to a lateral force during the tensioning process, the limit ring 10 can prevent it from deviating from the tensioning force-bearing position, ensuring that the prestressed tendon 17 is always in the correct force-bearing position, improving the accuracy and effectiveness of the supplementary tensioning. In other alternative embodiments, the part of the limit ring 10 in contact with the prestressed tendon 17 can be chamfered to prevent shear damage to the prestressed tendon 17.

[0052] Embodiment 2 In another typical embodiment of the present invention, as Figures 1-6 shown, a working method of an external prestressed tendon supplementary tensioning device for a bridge is given, using the external prestressed tendon supplementary tensioning device for a bridge as in Embodiment 1.

[0053] A working method of an external prestressed tendon supplementary tensioning device for a bridge includes: Fix the external prestressed tendon supplementary tensioning device for a bridge to the bridge through the frame 1. Both ends of the prestressed tendon 17 are fixed to the bridge, and the middle section abuts against the outside of the connecting column 901; The guide screw 12 rotates under the action of the power source and drives the main slider 11 to translate axially along the guide screw 12. On the one hand, the main slider 11 drives the secondary slider 6 to translate through the connecting column 901. On the other hand, when the main slider 11 drives the transmission rod 902 to translate, the gear connected to the end of the transmission rod 902 close to the main slider 11 meshes with the rack, so that the transmission rod 902 also rotates during translation, thereby transmitting the torque to the gear at the end of the transmission rod 902 close to the secondary slider 6. The gear at this end meshes with the rack for transmission to drive the secondary slider 6; make the secondary slider 6 move along the sliding guide 4, so that the main slider 11, the secondary slider 6 and the connecting column 901 move synchronously; The force transfer rod group 9 moves axially along the guide screw 12, thereby driving the prestressed tendon 17 to achieve supplementary tensioning and strengthening the bridge.

[0054] The supplementary tensioning device is firmly installed on the bridge, providing a stable foundation for subsequent tensioning operations. The device also has a steering function, reliably transmitting the prestress generated by the prestressed tendon 17 to the bridge. Moreover, according to the designed external prestress reinforcement scheme, the device can determine the height of the steering of the prestressed tendon 17 by adjusting the height of the connecting column 901. At the same time, the prestressed tendon 17 is accurately in contact with the connecting column 901 of the device, ensuring that the supplementary tensioning force can be effectively transmitted to the prestressed tendon 17. The device is firmly fixed at a specific position on the bridge by using the frame 1, preventing the device from shifting or shaking during the supplementary tensioning process and affecting the tensioning effect. By fixing both ends of the prestressed tendon 17 and making the middle section abut against the connecting column 901, the stress points and action range of the prestressed tendon 17 are determined, enabling the supplementary tensioning device to accurately apply tension to the prestressed tendon 17, preventing problems such as uneven stress and tensioning failure of the prestressed tendon 17 caused by insecure installation or poor contact, and improving the reliability and accuracy of the supplementary tensioning operation.

[0055] The power source drives the guide screw 12 to rotate. The main slider 11 makes an axial translation under the action of the screw-slider mechanism, driving the secondary slider 6 to move synchronously through the connecting column 901, forming a stable overall movement trend. At the same time, the transmission rod 902 makes a translation driven by the main slider 11. Since a gear-rack meshing is formed at the position where the main slider 11 is fitted, the transmission rod 902 also forms a rotational motion during translation and transmits torque to the gears at both ends, further driving the secondary slider 6 to ensure that the secondary slider 6 is at the same movement height as the main slider 11. As Figure 2 shown, when the external prestressed tendon 17 becomes slack, the main slider 11 and the secondary slider 6 jointly drive the position of the connecting column 901 to drop, thereby performing supplementary tensioning on the prestressed tendon 17 abutted by the driving part of the connecting column 901, effectively solving problems such as uneven stress and device inclination caused by asynchronous driving of existing devices, enabling the force transmission rod group 9 to stably and evenly apply tension to the prestressed tendon 17, and improving the accuracy of supplementary tensioning and the stability of the device.

[0056] As Figure 6 shown, multiple supplementary tensioning devices for external prestressed tendons of bridges can also be arranged on the bridge. The prestressed tendon 17 abuts against the driving parts of multiple supplementary tensioning devices for external prestressed tendons of bridges in sequence, and the supplementary tensioning devices for external prestressed tendons of bridges are adjusted respectively to perform supplementary tensioning on the prestressed tendon 17. For a relatively long or stress-complex prestressed tendon 17, through the coordinated operation of multiple devices, segmented and accurate supplementary tensioning of the prestressed tendon 17 is achieved, ensuring uniform stress of the entire prestressed tendon 17 and improving the bridge reinforcement effect.

[0057] As Figure 1As shown in the figure, positioning holes are provided in the protruding part on the outer side of the sliding guide rail 4, and positioning holes are also provided on the secondary slider 6. The positioning holes on the secondary slider 6 are threaded holes, which can cooperate with positioning bolts. After the secondary slider 6 is adjusted to the required position, the positioning bolt is adjusted so that the positioning bolt passes through the positioning hole on the secondary slider 6 and extends into the positioning hole on the sliding guide rail 4 to lock the relative positions of the secondary slider 6 and the sliding guide rail 4.

[0058] In addition, the positioning holes provided on the sliding guide rail 4 are arranged at intervals in sequence along the axial direction of the sliding guide rail 4, and it is ensured that the holes of the sliding guide rail 4 and the secondary slider 6 can fit. After the supplementary tensioning is completed, the positioning bolt can be tightened to ensure that the positioning hole on the secondary slider 6 corresponds to the positioning hole on the sliding guide rail 4 and lock the position of the secondary slider 6.

[0059] When supplementary tensioning is required, the positioning bolt can be rotated in the reverse direction to release the lock. When multiple external prestressed tendon supplementary tensioning devices for bridges are arranged on the bridge, the positions of the positioning holes where the secondary slider 6 is connected to the sliding guide rail 4 are kept consistent, so as to assist in controlling the heights of the abutted prestressed tendons 17 to be consistent.

[0060] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A device for supplementary tensioning of external prestressed tendons of a bridge, characterized in that, It includes a frame and a movable component. The movable component includes a main slider, a force transmission rod group, and a secondary slider. The main slider is engaged with a guide rail screw to form a screw-slider mechanism. The guide rail screw is rotatably installed on the frame. The secondary slider is engaged and installed on the sliding guide rail of the frame to form a sliding pair. The force transmission rod group includes a connecting column and a transmission rod rotatably installed within the connecting column. The main slider and the secondary slider are fixedly connected through the connecting column. Both ends of the transmission rod are respectively engaged with racks parallel to the guide rail screw through gears. The gears at both ends of the transmission rod rotate synchronously, causing the secondary slider and the main slider to translate synchronously. A driving portion for abutting against the prestressed tendon is formed outside the connecting column. The guide rail screw can receive the action of a power source and rotate.

2. The device for supplementary tensioning of external prestressed tendons of a bridge according to claim 1, characterized in that, The secondary sliders are respectively connected to both sides of the main slider through the force transmission rod group. Each secondary slider is respectively slidably engaged with a sliding guide rail, and driving portions are respectively formed on both sides of the main slider.

3. The device for supplementary tensioning of external prestressed tendons of a bridge according to claim 2, characterized in that, The force transmission rod groups on both sides of the main slider share the same transmission rod. The transmission rod penetrates through the main slider, causing the main slider and the secondary sliders on both sides of the main slider to move synchronously along the axial direction of the guide rail screw.

4. The device for supplementary tensioning of external prestressed tendons of a bridge according to claim 2, characterized in that, The transmission rod is respectively rotatably connected to the main slider and the secondary slider. The end of the transmission rod close to the secondary slider is an active gear, and the active gear is engaged with a driven rack through a transmission gear installed on the secondary slider.

5. The device for supplementary tensioning of external prestressed tendons of a bridge according to claim 4, characterized in that, The power input end of the guide rail screw is engaged with a worm and worm gear mechanism. The worm is engaged with the guide rail screw. The worm is installed on the frame through a support, and one end of the worm receives the action of a power source.

6. The device for supplementary tensioning of external prestressed tendons of a bridge according to claim 1, characterized in that, The main slider is engaged with two guide rail screws. The two guide rail screws rotate at the same speed and synchronously. The gear at the end of the transmission rod close to the main slider is a driving gear. The driving gear is engaged with a driving rack. The driving gear and the driving rack are located between the two guide rail screws. The driving rack penetrates through the main slider.

7. The device for supplementary tensioning of external prestressed tendons of a bridge according to claim 6, characterized in that, The force transmission rod group further includes a rotary sleeve. The rotary sleeve is rotatably sleeved outside the connecting column for contacting the prestressed tendon. Limiting rings protruding from the outer circumferential surface of the rotary sleeve are respectively provided at both ends of the rotary sleeve.

8. The device for supplementary tensioning of external prestressed tendons of a bridge according to claim 1, characterized in that, The secondary slider forms a chute with a T-shaped cross-section. The chute is engaged with the sliding guide rail. The gear at the end of the transmission rod close to the secondary slider and the engaged rack are located within the chute.

9. A working method of a device for supplementary tensioning of external prestressed tendons of a bridge, using the device for supplementary tensioning of external prestressed tendons of a bridge according to any one of claims 1-8, characterized in that, It includes: Fix the external prestressed tendon supplementary tensioning device of the bridge to the bridge through the frame. Both ends of the prestressed tendon are fixed to the bridge, and the middle section abuts against the outside of the connecting column. The guide rail screw receives the action of the power source and rotates, driving the main slider to translate along the axial direction of the guide rail screw. On the one hand, the main slider drives the secondary slider to translate through the connecting column. On the other hand, when the main slider drives the transmission rod to translate, through the engagement of the gear connected to the end of the transmission rod close to the main slider with the rack, the transmission rod also rotates during translation, thereby transmitting the torque to the gear at the end of the transmission rod close to the secondary slider. The gear at this end is engaged with the rack for transmission to achieve the drive of the secondary slider. Cause the secondary slider to move along the sliding guide rail, making the main slider, the secondary slider, and the connecting column move synchronously. The force transmission rod group moves along the axial direction of the guide rail screw, thereby driving the prestressed tendon to achieve supplementary tensioning and strengthening the bridge.

10. The working method of a device for supplementary tensioning of external prestressed tendons of a bridge according to claim 9, characterized in that, Arrange multiple external prestressed tendon supplementary tensioning devices of the bridge on the bridge. The prestressed tendons sequentially abut against the driving portions of multiple external prestressed tendon supplementary tensioning devices of the bridge, and respectively adjust the external prestressed tendon supplementary tensioning devices of the bridge to perform supplementary tensioning on the prestressed tendons.

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