A bridge external prestressed bundle tensioning device and working method

Abstract

The present invention provides a device and a working method for compensating and tensioning external prestressed bundles of a bridge, which relate to the field of bridges. Aiming at the problem that the current device for compensating and tensioning external prestressed bundles of a bridge is poor in stability and easily fails to topple due to force offset, the main slider and the guide rail screw are matched to form a screw slider mechanism, the auxiliary slider and the frame sliding guide rail are matched to form a sliding pair, the main slider and the auxiliary slider are fixedly connected by a connecting column, and the main slider, the auxiliary slider and the connecting column can move together during movement, and a transmission rod is rotatably arranged in the connecting column. The main slider serves as the main driving end, and the auxiliary slider serves as the auxiliary driving end, which jointly drive the connecting column to move horizontally from both ends of the connecting column, so that the connecting column compensates and tensions the prestressed bundle. The main slider and the auxiliary slider form a multi-point support structure for the connecting column, and the contact position of the prestressed bundle and the connecting column is always located between the main slider and the auxiliary slider, thereby reducing the risk caused by force offset.

Description

Technical Field

[0001] The present invention relates to the field of bridges, and in particular to a bridge external prestressed bundle tensioning device and a working method. Background Art

[0002] By tensioning the external prestressed tendons, the structure's load-bearing capacity and stiffness can be increased, improving its mechanical properties. Relaxation of the tendons causes the tensile stress in the tendons to gradually decrease over time, reducing the effective prestress transmitted to the structure. This reduces the structure's ability to withstand external loads and increases deformation, impacting its performance. By supplementing the tension of the external prestressed tendons, the tensile force can be increased, compensating for the loss of prestress and placing the beam in a more favorable compressive state.

[0003] A Chinese patent (publication number CN115288042A, publication date 20221104) discloses a reinforcement device and construction method for external prestressed reinforcement with precise tensioning. The device, which is permanently installed on a prestressed concrete beam, precisely controls the distance between the prestressed tendons and the bottom of the concrete beam through the combination of a worm gear and a stress control assembly. A worm gear is slidably mounted on a round rod, enabling the worm gear to move a channel assembly underneath, through which the prestressed tendons are inserted, thereby tensioning the tendons. The channel assembly can provide vertical thrust, but it cannot be adaptively adjusted in the horizontal direction perpendicular to the vertical plane of the prestressed tendons, resulting in poor stability in the horizontal direction perpendicular to the fixed concrete beam. When the prestressed tendons are offset horizontally and perpendicularly to the direction of the concrete beam, the compensating tensioning structure will be tilted and fail. Therefore, high installation accuracy requirements are placed on the entire reinforcement device, resulting in poor adaptability. Moreover, if the number of channel components is increased in the reinforcement device for external prestressed precision compensating tensioning, the channel components will be expanded in a direction perpendicular to the concrete beam, and the positions of some channel components will not be collinear with the sliding direction of the worm, forming a cantilever structure. When the channel components are pushed to move and tension the prestressed tendons, offsets will still occur, causing the compensating tensioning structure to tilt and be stressed, increasing the risk of collapse and failure. Summary of the Invention

[0004] The purpose of the present invention is to address the defects of the existing technology and provide a bridge external prestressed bundle tensioning device and working method. The main slider and the guide rail screw are combined to form a screw slider mechanism, the auxiliary slider and the frame sliding guide rail are combined to form a sliding pair, and the main slider and the auxiliary slider are fixedly connected by a connecting column. When moving, the main slider, the auxiliary slider and the connecting column can move together. The outer circumference of the connecting column can provide a larger abutment range in the axial direction, thereby expanding the working range of the driving part that abuts the prestressed bundle, improving the adaptability to the prestressed bundle, and ensuring stability during the tensioning process.

[0005] The first object of the present invention is to provide a bridge external prestressed tendon tensioning device, which adopts the following scheme:

[0006] The cam is mounted on a cam frame and is provided with a plurality of movable members, wherein the movable members include a main slider, a force transmission rod group and a sub-slider. The main slider is equipped with a guide screw to form a screw slider mechanism. The guide screw is rotatably installed on the frame. The sub-slider is equipped with a sliding guide rail installed on the frame to form a sliding pair. The force transmission rod group includes a connecting column and a transmission rod rotatably installed in the connecting column. The main slider and the sub-slider are fixedly connected by the connecting column. Racks parallel to the guide screw are respectively engaged with gears at both ends of the transmission rod. The gears at both ends of the transmission rod rotate synchronously, so that the sub-slider and the main slider move synchronously. A driving part that abuts the prestressed beam is formed outside the connecting column, and the guide screw can be acted upon by the power source and rotate.

[0007] Furthermore, both sides of the main slider are connected to auxiliary sliders through force transmission rod groups, and each auxiliary slider is slidably matched with a sliding guide rail, forming a driving part on both sides of the main slider.

[0008] Furthermore, the force transmission rod groups on both sides of the main slider share the same transmission rod, which passes through the main slider, so that the main slider and the auxiliary sliders on both sides of the main slider move synchronously along the axial direction of the guide rail screw.

[0009] Furthermore, the transmission rod is rotatably connected to the main slider and the auxiliary slider respectively. The end of the transmission rod close to the auxiliary slider is a driving gear, and the driving gear engages with the driven rack through a transmission gear installed on the auxiliary slider.

[0010] Furthermore, the power input end of the guide rail screw is matched with a worm gear mechanism, the worm gear is matched with the guide rail screw, the worm is installed on the frame through a support, and one end of the worm is subjected to the action of the power source.

[0011] Furthermore, the main slider is equipped with two guide screws, which rotate synchronously at the same speed. The gear at one end of the transmission rod close to the main slider is the driving gear, which engages the driving rack. The driving gear and the driving rack are located between the two guide screws, and the driving rack runs through the main slider.

[0012] Furthermore, the force transmission rod group also includes a rotating sleeve, which is arranged outside the connecting column and is used to contact the prestressed bundle. The two ends of the rotating sleeve are respectively provided with a limiting ring protruding from the outer circumferential surface of the rotating sleeve.

[0013] Furthermore, the auxiliary slider forms a slide groove with a T-shaped cross-section, the slide groove cooperates with the sliding guide rail, and the gear at one end of the transmission rod close to the auxiliary slider and the meshed rack are located in the slide groove.

[0014] A second object of the present invention is to provide a method for operating the external prestressed tendon tensioning device for a bridge as described in the first object, comprising:

[0015] The bridge external prestressed tendon tensioning device is fixed to the bridge through a frame, with both ends of the prestressed tendon fixed to the bridge and the middle section abutting against the outside of the connecting column;

[0016] The guide screw receives the power source to rotate and drive the main slider to translate along the axial direction of the guide screw. On the one hand, the main slider drives the auxiliary 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 near the main slider engages with the rack, so that the transmission rod also rotates while it translates, thereby transmitting the torque to the gear at the end of the transmission rod near the auxiliary slider. The gear at this end engages with the rack for transmission, thereby driving the auxiliary slider; the auxiliary slider moves along the sliding guide rail, and the main slider, auxiliary slider and connecting column move synchronously;

[0017] The force transmission rod group moves axially along the guide rail screw, thereby driving the prestressed tendons to achieve tensioning and reinforce the bridge.

[0018] Furthermore, multiple external prestressed beam tensioning devices are arranged on the bridge, and the prestressed beams are sequentially abutted against the driving parts of multiple external prestressed beam tensioning devices. The external prestressed beam tensioning devices are adjusted respectively to tension the prestressed beams.

[0019] Compared with the prior art, the present invention has the following advantages and positive effects:

[0020] In order to solve the problem that the current external prestressed tensioning reinforcement device of bridge has poor stability and is prone to overturning and failure due to force offset, the main slider and the guide rail screw are combined to form a screw slider mechanism, and the auxiliary slider and the frame sliding guide rail are combined to form a sliding pair. The main slider and the auxiliary slider are fixedly connected by a connecting column, and the main slider, the auxiliary slider and the connecting column can move together during movement. The outer circumference of the connecting column can provide a larger abutment range in the axial direction, thereby expanding the working range of the driving part that abuts the prestressed beam and improving the adaptability to the prestressed beam; at the same time, a transmission rod is rotatably arranged in the connecting column, and the main slider serves as the main driving end. The transmission rod can rotate following the translation of the connecting column. After the transmission rod is close to the gear meshing rack at one end of the main slider, the transmission rod transmits torque to the other end close to the auxiliary slider, so that the gear at the auxiliary slider moves along the gear The bar moves, and a translational driving force is applied to the auxiliary slider as the auxiliary driving end, which drives the connecting column to move horizontally from both ends of the connecting column, so that the connecting column can supplement the tensioning of the prestressed beam. The main slider and the auxiliary slider form a multi-point support structure for the connecting column. The contact position of the prestressed beam and the connecting column is always between the main slider and the auxiliary slider, which reduces the risk of force offset. Compared with the unilateral cantilever drive mechanism, it reduces the risk of bending due to asynchronous movement of the two ends of the connecting column caused by uneven force; the driving part outside the connecting column can stably abut the prestressed beam, and its large range can adapt to prestressed beams in different positions, thereby ensuring the accuracy of supplementary tensioning and reducing the requirements for installation accuracy. When the prestressed beam has a horizontal offset perpendicular to the axis of the fixed beam, the prestressed beam can still be within the abutment range of the driving part, maintaining a good working state.

[0021] Starting from the transmission of force and the coordinated movement of the structure, the design of gear rack transmission and synchronous translation of the main and auxiliary sliders is used to ensure uniform distribution of force during the tensioning process, thereby enhancing the device's ability to resist displacement; the setting of the connecting column drive part ensures stable contact with the prestressed beam, further improving the accuracy and stability of the tensioning, so that the tensioning device can work stably under complex working conditions and reduce dependence on installation accuracy.

[0022] The two sides of the main slider are connected to the auxiliary slider through a force transmission rod group, and driving parts are 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, so that the main slider and the auxiliary sliders on both sides move synchronously along the axial direction of the guide rail screw, and the two prestressed beams can be tensioned at the same time, which is in line with the actual layout of the bridge when using extracorporeal prestressing for reinforcement. The symmetrical multi-slider collaborative structure has a relatively balanced force on both sides of the main slider, avoiding the offset caused by unilateral acceptance of the main slider, and further enhancing the stability of the tensioning device during operation.

[0023] The auxiliary slider forms a slide groove with a T-shaped cross-section, and the slide groove cooperates with the sliding guide rail. The gear at one end of the transmission rod close to the auxiliary slider and the meshing rack are located in the slide groove, integrating the transmission components in the internal space of the auxiliary slider. On the one hand, it reduces the impact of external interference on the transmission system and improves the reliability of the transmission; on the other hand, the cooperation between the T-shaped slide groove and the sliding guide rail limits the movement of the auxiliary slider in the axial direction along the non-sliding guide rail, so that the auxiliary slider can only move horizontally along the predetermined sliding guide rail direction, ensuring the accuracy of the force transmission direction and improving the overall stability of the device.

[0024] The power input end of the guide screw is matched with a worm gear mechanism. The worm gear mechanism has a self-locking feature, which can keep the guide screw in a fixed state after the tensioning is completed, preventing the transmission rod from reversing due to external force after the tensioning is completed, and jointly maintaining the stability of the device after the tensioning is completed.

[0025] The rotating sleeve in the force transmission rod group is arranged outside the connecting column to contact the prestressed beam, and raised limit rings are provided at both ends of the rotating sleeve. The rotating sleeve changes the friction between the prestressed beam and the device from sliding friction to rolling friction during the tensioning process, which greatly reduces the friction force, reduces the wear on the surface of the prestressed beam, and protects the performance of the prestressed beam; the limit rings at both ends can prevent the prestressed beam from lateral deviation during the tensioning process, ensuring that the prestressed beam is always in the correct force-bearing position, and improving the accuracy and effectiveness of the tensioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] Figure 1 Schematic diagram of a bridge external prestressed tendon tensioning device in one or more embodiments of the present invention.

[0028] Figure 2 It is a side view schematic diagram of a bridge external prestressed tendon tensioning device in one or more embodiments of the present invention.

[0029] Figure 3 Schematic diagram of a driving gear meshing with a transmission gear in one or more embodiments of the present invention.

[0030] Figure 4 Schematic diagram of a worm gear mechanism in one or more embodiments of the present invention.

[0031] Figure 5 Schematic diagram of a dowel rod assembly in one or more embodiments of the present invention.

[0032] Figure 6This is a schematic diagram of an external prestressed tendon tensioning device for a bridge arranged on a bridge in one or more embodiments of the present invention.

[0033] Among them, 1. Frame; 101. Anchor bolt; 2. Side support plate; 3. Top plate; 4. Sliding guide rail; 5. Drive rack; 6. Auxiliary slider; 7. Transmission gear; 8. Driven rack; 9. Force transmission rod group; 901. Connecting column; 902. Transmission rod; 903. Drive gear; 904. Active gear; 905. Rotating sleeve; 10. Limiting ring; 11. Main slider; 12. Guide rail screw; 13. Worm gear; 14. Worm; 15. Support; 16. Bottom plate; 17. Prestressed beam; 18. Bridge deck; 19. Longitudinal beam. DETAILED DESCRIPTION

[0034] Example 1

[0035] In a typical embodiment of the present invention, Figures 1-6 As shown, a bridge external prestressed tendon tensioning device is provided.

[0036] The existing external prestressed precision tensioning and reinforcement devices have the problems of poor stability, high requirements for installation accuracy, and poor adaptability. When the working space is expanded by increasing the number of channel components, the length of the channel components in the direction perpendicular to the axis of the installed beam will increase, and some channel components will extend beyond the sliding position to form cantilevers. When these channel components are inserted into the prestressed tendons for tensioning, deviations are likely to occur, causing the tensioning structure to tilt under stress or even collapse and fail. Based on this, this embodiment provides a bridge external prestressed beam tensioning device, which adopts a structure in which the main slider 11, the connecting column 901 and the auxiliary slider 6 are connected in sequence. The main slider 11 and the guide screw 12 are combined to form a screw slider mechanism, which serves as the power input position and drives the auxiliary slider 6 to move horizontally through the connecting column 901. At the same time, the internal transmission rod 902 of the connecting column 901 can use the gear rack mechanism to form rotation during translation to drive the auxiliary slider 6. The main slider 11 and the auxiliary slider 6 drive the connecting column 901 from both ends at the same time to move. The outer circumference of the connecting column 901 can provide a larger abutment range in the axial direction, thereby expanding the working range of the driving part that abuts the prestressed beam 17, improving the adaptability to the prestressed beam 17, and ensuring stability during the tensioning process.

[0037] like Figures 1-6 As shown, the bridge external prestressed tendon tensioning device mainly includes a frame 1 and a movable component, and the movable component includes a main slider 11, a force transmission rod group 9 and an auxiliary slider 6.

[0038] The frame 1 serves as the basic supporting component of the entire tensioning device and provides a platform for the installation and fixing of other components. Figure 1As 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 components are installed within the frame structure. The tops of the side support plates 2 extend beyond the top plate 3. The portions extending beyond the top plate 3 can have through-holes for fasteners such as anchor bolts 101 and expansion bolts to mount the frame 1 on the bridge. The top plate 3 and side support plates 2, and the bottom plate 16 and side support plates 2 can be connected by welding or fasteners.

[0039] like Figure 6 As shown, the frame 1 is fixed to the bridge's longitudinal beam 19 via anchor bolts 101. The spacing between the frame 1's two side support plates 2 matches the width of the bridge's longitudinal beam 19, allowing the two side support plates 2 to be fixed to either side of the longitudinal beam 19. The bridge deck 18 is laid on top of the bridge. The stable frame 1 structure ensures the stability and structural strength of the entire device, allowing each component to maintain a fixed relative position during operation and withstand the various forces generated during the tensioning process. This provides a stable support base for the device, preventing overall shaking or displacement due to an unstable foundation, which could affect the accuracy and stability of the tensioning.

[0040] The main slider 11 cooperates with the guide rail screw 12 to form a screw slider mechanism, and the guide rail screw 12 is rotatably mounted on the frame 1. Figure 1 As shown, both ends of the guide screw 12 can be mounted on the frame 1 through bearings respectively. The bearings can be tapered roller bearings, thrust ball bearings, etc. A threaded hole is provided on the main slider 11, and the guide screw 12 passes through the threaded hole and forms a threaded fit with the threaded hole. The guide screw 12 is driven by an external force to rotate around its axis, and the rotational motion is converted into a linear motion of the main slider 11. In other optional embodiments, a ball screw pair can be formed between the main slider 11 and the guide screw 12, and balls are set at the matching position of the main slider 11 and the guide screw 12, thereby improving the transmission efficiency, reducing the friction factor, and improving the smoothness of the movement. In this embodiment, the axis of the guide screw 12 is vertically distributed, and the main slider 11 is lifted and lowered vertically under the drive of the guide screw 12, so as to realize the precise control of the position of the main slider 11, thereby driving the entire movable component to move and perform tensioning operation on the prestressed bundle 17.

[0041] During the tensioning process, the power source drives the guide screw 12 to rotate, causing the main slider 11 to move smoothly along the axial direction of the guide screw 12. This not only provides power for the movement of the main slider 11, but also guides its movement. Compared to traditional drive methods, the screw-slider mechanism can provide precise displacement control, ensuring the accuracy and stability of the movement of the main slider 11. This can accurately control the tension applied to the prestressed tendon 17, improve the accuracy of the tensioning process, and solve the problem of poor tensioning effect caused by inaccurate drive in existing devices.

[0042] The auxiliary slider 6 cooperates with the sliding guide rail 4 installed on 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 auxiliary 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 component to ensure the stability and linearity of the movable component during movement. The auxiliary slider 6 works together with the main slider 11 to jointly bear the reaction force generated when the prestressed beam 17 is tensioned.

[0043] During the movement of the main slider 11, the auxiliary slider 6 slides synchronously along the sliding guide rail 4. Since the outer ring of the connecting column 901 abutting the prestressed beam 17 is located between the main slider 11 and the auxiliary slider 6, the main slider 11 and the auxiliary slider 6 support and drive the connecting column 901 from both sides, and can abut the prestressed beam 17 as a driving part along the entire axial length of the connecting column 901. Even if the prestressed beam 17 is offset along the axial direction of the connecting column 901, that is, perpendicular to the horizontal direction of the beam installed on the frame 1, it is within the abutment range of the connecting column 901, which expands the working range compared with the prior art. The two ends of the connecting column 901 connect the main slider 11 and the auxiliary slider 6 to form a multi-point support structure, which maintains the balance of the movable component and avoids the device from failing due to changes in the action position of the prestressed beam 17 or different action positions, thereby significantly improving the stability and anti-offset ability of the device.

[0044] The force transmission rod group 9 includes a connecting column 901 and a transmission rod 902 rotatably mounted in the connecting column 901. The main slider 11 and the auxiliary slider 6 are fixedly connected by the connecting column 901, so that the main slider 11 and the auxiliary slider 6 can be forced to move synchronously; and the two ends of the transmission rod 902 are respectively engaged with racks through gears, and the racks are parallel to the guide screw 12. The gears at both ends of the transmission rod 902 rotate synchronously, so that the gear at one end of the transmission rod 902 close to the auxiliary slider 6 is driven, and then the auxiliary slider 6 climbs or descends along the rack, forming a secondary drive; the outside of the connecting column 901 forms a driving part that abuts the prestressed beam 17. In this embodiment, Figure 2 and Figure 5 As shown, the connecting column 901 is used to abut the prestressed bundle 17 to achieve tensioning of the prestressed bundle 17; the transmission rod 902 transmits the movement of the main slider 11 to the auxiliary slider 6 through the engagement of the gear and the rack, so that the main slider 11 and the auxiliary slider 6 move synchronously, ensuring that the two ends of the connecting column 901 are evenly stressed; the driving part can act on the prestressed bundle 17 to provide sufficient tensioning force.

[0045] Specifically, during operation, the main slider 11 moves, driving the connecting column 901 and the transmission rod 902 to move in translation. During the translation process, the transmission rod 902 forms a gear rack meshing at the position of the main slider 11, so that the transmission rod 902 also forms a rotational motion during translation, thereby transmitting torque to the gear on the auxiliary slider 6, so that the gear on the auxiliary slider 6 is driven, thereby causing the auxiliary slider 6 to move synchronously, forming a multi-point support structure for the connecting column 901. The contact position of the prestressed bundle 17 and the connecting column 901 is always located between the main slider 11 and the auxiliary slider 6. No matter how the prestressed bundle 17 is offset horizontally between the main slider 11 and the auxiliary 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 due to uneven stress. At the same time, the larger range of the driving part outside the connecting column 901 can adapt to the prestressed bundles 17 in different positions, reducing the requirements for installation accuracy. Even if the prestressed bundles 17 appear to be horizontally offset perpendicular to the axis of the beam, effective abutment and tensioning can still be guaranteed, thereby improving the adaptability of the device and the accuracy of supplementary tensioning.

[0046] like Figure 2 As shown, the main slider 11 is connected to the auxiliary sliders 6 on both sides via a force transmission rod group 9. Each auxiliary slider 6 cooperates with the sliding guide rail 4, forming a drive unit on each side of the main slider 11. The force transmission rod groups 9 on both sides share a transmission rod 902 that runs through the main slider 11, achieving synchronous movement of the main slider 11 and the auxiliary sliders 6 on both sides along the axial direction of the guide rail screw 12. This establishes a symmetrical force system, enhances the device's adaptability to the action of the prestressed beam 17 at different positions on the connecting column 901, and improves overall stability and the tensioning effect.

[0047] Compared to single-sided drive, the symmetrical multi-slider structure effectively offsets the unbalanced forces caused by offset, reducing the risk of device tilt. If the prestressed strand 17 deflects to one side, the two auxiliary sliders 6 synchronize their movement with the main slider 11, keeping the connecting column 901 in a stable stress state. This ensures precise and stable tensioning operation and improves the reliability of the device under complex working conditions.

[0048] like Figure 3 and Figure 5As shown, the transmission rod 902 is rotatably connected to the main slider 11 and the auxiliary slider 6 respectively, and a bearing is installed at the rotation connection position. A driving gear 903 is installed at the transmission rod 902 near the main slider 11. The rack engaged with the driving gear 903 is the driving rack 5. In this embodiment, the driving gear 903 is installed in the main slider 11, and the driving rack 5 is distributed along the axis parallel to the guide screw 12. When the main slider 11 is lifted and lowered along the guide screw 12, the driving gear 903 is kept engaged with the driving rack 5, and the main slider 11 is used to drive the translation of the driving gear 903 to be converted into the rotation of the driving gear 903. The force transmission rod group 9 shares a common root that runs through the main slider 1 1, the driving gear 903 is installed in the middle of the transmission rod 902, and the driving gear 904 is installed at the end of the transmission rod 902 close to the auxiliary slider 6. The driving gears 904 are respectively installed at both ends of the corresponding transmission rod 902. The rotation of the driving gear 903 is transmitted to the driving gears 904 at both ends of the transmission rod 902 through the transmission rod 902. The driving gear 904 engages with the driven rack 8 through the transmission gear 7 installed on the auxiliary slider 6. When the transmission rod 902 drives the driving gears 904 at both ends thereof to rotate, the driving gear 904 drives the transmission gear 7 to rotate, so that the transmission gear 7 engages with the driven rack 8 to drive the auxiliary slider 6 to rise or fall.

[0049] like Figure 3 As shown, there are multiple transmission gears 7, one of which is meshed with the driven rack 8 and the driving gear 904 at the same time, and the other driven gears are only meshed with the driven rack 8 as auxiliary guides.

[0050] Combine Figure 3 and Figure 5 , the transmission rod 902 is rotatably connected to the main slider 11 and the auxiliary slider 6, and the driving gear 904 at the auxiliary slider 6 is engaged with the driven rack 8 through the transmission gear 7. In addition, Figure 1 and Figure 4 As shown, a worm gear mechanism is configured at the power input end of the guide screw 12. A worm wheel 13 cooperates with the guide screw 12, causing the worm wheel 13 and the guide screw 12 to rotate coaxially and synchronously. A worm 14 is mounted on the frame 1 via a support 15, and one end of the worm 14 is connected to a power source. Support 15 can be a rotating seat, and the worm 14 is mounted on support 15 via a bearing, etc., and support 15 is fixed to the frame 1. The power source can be an electric motor, a wrench, a hydraulic motor, etc.

[0051] The main slider 11 is coupled to two guide screws 12 that rotate synchronously at the same speed. In this embodiment, a corresponding worm gear 13 is mounted on each guide screw 12, and the same worm 14 is used to synchronously drive both worm gears 13. Utilizing the self-locking properties of the worm gear 13 and worm 14, the rotation of the worm 14 is unidirectionally transmitted to the worm gear 13, causing the worm gear 13 to rotate, while the rotation of the worm gear 13 cannot drive the worm 14 to rotate. The worm gear 13 locks the position of the guide screw 12, ensuring stable maintenance of the post-tensioning device while providing precise power transmission.

[0052] After the tensioning is complete, the worm gear mechanism automatically locks, preventing the guide screw 12 from rotating due to external forces or vibration, ensuring the fixed position of the main slider 11 and avoiding unexpected changes in the tension of the prestressed bundle 17. The self-locking effect of the worm gear mechanism prevents the prestressed bundle 17 from retracting after the tensioning is complete, ensuring a stable tensioning effect and avoiding loss of prestress due to external interference. Furthermore, the transmission ratio characteristics of the worm gear mechanism enable precise control of the guide screw 12, making the movement of the main slider 11 smoother and more precise, further improving the accuracy of the tensioning.

[0053] The main slider 11 is coupled with two guide screws 12 that rotate synchronously at the same speed. A drive gear 903 at the end of the transmission rod 902 near the main slider 11 meshes with a drive rack 5 located between the two screws. The drive rack 5 extends through the main slider 11. This enhances the smoothness and driving force of the main slider 11 and improves the device's ability to tension heavily loaded prestressed tendons 17.

[0054] Two guide screws 12, rotating synchronously at equal speeds, provide uniform and stable driving force for the main slider 11. Compared to a single-screw drive, the dual-screw structure disperses the force, reducing screw wear and extending the device's service life. Furthermore, the optimized layout of the drive gear 903 and the drive rack 5 ensures balanced force on the main slider 11 during movement, minimizing any shaking or offset caused by uneven force. This makes the tensioning operation more stable and reliable, making it particularly suitable for applications requiring high prestressing forces, such as long-span bridges.

[0055] like Figure 3 and Figure 5 As shown, the auxiliary slider 6 adopts a T-section slide groove to cooperate with the sliding guide rail 4, and the gear and meshing rack at one end of the transmission rod 902 close to the auxiliary slider 6 are arranged in the slide groove.

[0056] The T-shaped chute and guide rail 4 form multi-directional constraints on the auxiliary slider 6, limiting its non-axial movement and ensuring smooth sliding of the auxiliary slider 6 along the predetermined direction. Placing the transmission components within the chute effectively prevents the transmission system from being affected by external debris and dust, thereby improving transmission reliability. Furthermore, this layout makes the auxiliary slider 6 more compact, enhancing the overall stability and anti-interference capabilities of the device.

[0057] like Figure 5 As shown, the dowel rod assembly 9 is equipped with a rotating sleeve 905. The rotating sleeve contacts the prestressed bundle 17 outside the connecting column 901. The rotating sleeve 905 acts as a driving part to abut the prestressed bundle 17. Limiting rings 10 are provided at both ends of the rotating sleeve 905 to reduce friction between the prestressed bundle 17 and the device, protect the surface of the prestressed bundle 17, and prevent lateral deviation of the prestressed bundle 17. During the tensioning process, the rotating sleeve 905 converts sliding friction into rolling friction, significantly reducing friction, reducing wear on the surface of the prestressed bundle 17, and extending its service life. The limiting rings 10 at both ends limit the prestressed bundle 17. Even if the prestressed bundle 17 is subjected to lateral force during the tensioning process, the limiting rings 10 can prevent it from deviating from the tensioning position, ensuring that the prestressed bundle 17 is always in the correct stress-bearing position, improving the accuracy and effectiveness of the tensioning process. In other optional embodiments, the contact portion of the limiting ring 10 with the prestressed bundle 17 can be chamfered to prevent shear damage to the prestressed bundle 17.

[0058] Example 2

[0059] In another typical embodiment of the present invention, Figures 1-6 As shown, a working method of a bridge external prestressed beam tensioning device is provided, using the bridge external prestressed beam tensioning device as in Example 1.

[0060] A working method of a bridge external prestressed tendon tensioning device, comprising:

[0061] The bridge external prestressed beam tensioning device is fixed to the bridge through the frame 1, with both ends of the prestressed beam 17 fixed to the bridge and the middle section abutting against the outside of the connecting column 901;

[0062] The guide screw 12 receives the power source to rotate and drive the main slider 11 to translate along the axial direction of the guide screw 12. On the one hand, the main slider 11 drives the auxiliary 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 engages 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 auxiliary slider 6. The gear at this end engages with the rack for transmission, thereby driving the auxiliary slider 6; the auxiliary slider 6 moves along the sliding guide rail 4, so that the main slider 11, the auxiliary slider 6 and the connecting column 901 move synchronously;

[0063] The force transmission rod group 9 moves axially along the guide rail screw 12, thereby driving the prestressed bundle 17 to achieve tensioning and reinforce the bridge.

[0064] The supplementary tensioning device is securely mounted on the bridge, providing a stable foundation for subsequent tensioning operations. The device also functions as a steering mechanism, reliably transferring the prestress generated by the prestressed bundle 17 to the bridge. Furthermore, the device can adjust the height of the connecting column 901 according to the designed external prestressing reinforcement scheme to determine the steering height of the prestressed bundle 17. At the same time, the prestressed bundle 17 is precisely contacted with the device's connecting column 901, ensuring that the supplementary tensioning force can be effectively transferred to the prestressed bundle 17. The device is securely fixed to a specific location on the bridge using a frame 1 to prevent displacement or shaking during the supplementary tensioning process, which could affect the tensioning effect. By fixing both ends of the prestressed bundle 17 and abutting its midsection against the connecting column 901, the force points and range of action of the prestressed bundle 17 are determined, enabling the supplementary tensioning device to accurately apply tension to the prestressed bundle 17. This prevents problems such as uneven force on the prestressed bundle 17 and tensioning failure caused by loose installation or poor contact, thereby improving the reliability and accuracy of the supplementary tensioning operation.

[0065] The power source drives the guide screw 12 to rotate, and the main slider 11 moves axially under the action of the screw slider mechanism, driving the auxiliary slider 6 to move synchronously through the connecting column 901, forming a stable overall movement trend. At the same time, the transmission rod 902 moves horizontally under the drive of the main slider 11. Due to the gear rack meshing formed at the position of the main slider 11, the transmission rod 902 also forms a rotational movement while moving horizontally, and transmits torque to the gears at both ends, further driving the auxiliary slider 6, ensuring that the movement of the auxiliary slider 6 and the main slider 11 are highly synchronized. Figure 2 As shown, when the extracorporeal prestressed bundle 17 relaxes, the main slider 11 and the auxiliary slider 6 jointly drive the connecting column 901 to descend, thereby compensating and stretching the prestressed bundle 17 abutted by the driving portion of the connecting column 901, effectively solving the problems of uneven force and device tilt caused by asynchronous driving in the existing device, so that the force transmission rod group 9 can stably and evenly apply tension to the prestressed bundle 17, thereby improving the accuracy of compensating and stretching and the stability of the device.

[0066] like Figure 6 As shown, multiple external prestressed tendon tensioning devices can also be deployed on the bridge. The prestressed tendon 17 sequentially abuts the drive units of these devices, and each device is adjusted to tension the prestressed tendon 17. For long or complexly stressed prestressed tendons 17, multiple devices can work together to achieve segmented and precise tensioning of the prestressed tendon 17, ensuring uniform stress across the entire prestressed tendon 17 and improving the bridge reinforcement effect.

[0067] like Figure 1As shown, a positioning hole is provided on the outer protruding part of the sliding guide rail 4, and a positioning hole is also provided on the auxiliary slider 6. The positioning hole on the auxiliary slider 6 is a threaded hole that can be matched with a positioning bolt. After the auxiliary slider 6 is adjusted to the desired position, the positioning bolt is adjusted so that the positioning bolt passes through the positioning hole on the auxiliary slider 6 and penetrates into the positioning hole on the sliding guide rail 4, thereby locking the relative position of the auxiliary slider 6 and the sliding guide rail 4.

[0068] In addition, the positioning holes provided on the sliding guide rail 4 are arranged in a sequentially spaced order along the axial direction of the sliding guide rail 4, and ensure that the sliding guide rail 4 and the holes of the auxiliary slider 6 can fit together. After the tensioning is completed, the positioning bolts can be tightened to ensure that the positioning holes on the auxiliary slider 6 correspond to the positioning holes on the sliding guide rail 4, locking the position of the auxiliary slider 6.

[0069] When additional tensioning is required, the positioning bolts can be reversed to unlock them. When multiple external prestressed beam tensioning devices are deployed on a bridge, the positioning holes connecting the auxiliary slider 6 and the sliding guide rail 4 are kept in the same position, thereby helping to maintain the same height of the prestressed beams 17 they abut against.

[0070] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A bridge external prestressed tendon tensioning device, characterized in that: The movable assembly includes a main slider, a force transmission rod group and a secondary slider. The main slider is matched with a guide screw to form a screw slider mechanism. The guide screw is rotatably mounted on the frame. The secondary slider is matched with a sliding guide rail mounted on the frame to form a sliding pair. The force transmission rod group includes a connecting column and a transmission rod rotatably mounted in the connecting column. The main slider and the secondary slider are fixedly connected by the connecting column. Racks parallel to the guide screw are respectively engaged with gears at both ends of the transmission rod. The gears at both ends of the transmission rod rotate synchronously, so that the secondary slider and the main slider move synchronously. A driving part that abuts the prestressed beam is formed outside the connecting column. The guide screw can receive the action of the power source and rotate. The two sides of the main slider are connected to the auxiliary sliders through the force transmission rod group, and each auxiliary slider is slidably matched with a sliding guide rail, forming a driving part on both sides of the main slider; The force transmission rod groups on both sides of the main slider share the same transmission rod, which runs through the main slider, so that the main slider and the auxiliary sliders on both sides of the main slider move synchronously along the axial direction of the guide rail screw.

2. The bridge external prestressed tendon tensioning device according to claim 1, characterized in that: The transmission rod is rotatably connected to the main slider and the auxiliary slider respectively. The end of the transmission rod close to the auxiliary slider is a driving gear, and the driving gear meshes with the driven rack through the transmission gear installed on the auxiliary slider.

3. The bridge external prestressed tendon tensioning device according to claim 2, characterized in that: The power input end of the guide rail screw is matched with a worm gear mechanism, the worm gear is matched with the guide rail screw, the worm is installed on the frame through a support, and one end of the worm is subjected to the action of the power source.

4. The bridge external prestressed tendon tensioning device according to claim 1, characterized in that: The main slider is equipped with two guide screws, which rotate synchronously at the same speed. The gear on the transmission rod close to one end of the main slider is the driving gear, which engages the driving rack. The driving gear and the driving rack are located between the two guide screws, and the driving rack runs through the main slider.

5. The bridge external prestressed tendon tensioning device according to claim 4, characterized in that: The force transmission rod group also includes a rotating sleeve, which is arranged outside the connecting column and is used to contact the prestressed bundle. The two ends of the rotating sleeve are respectively provided with a limiting ring protruding from the outer circumferential surface of the rotating sleeve.

6. The bridge external prestressed tendon tensioning device according to claim 1, characterized in that: The auxiliary slider forms a slide groove with a T-shaped cross section, the slide groove cooperates with the sliding guide rail, and the gear at one end of the transmission rod close to the auxiliary slider and the meshed rack are located in the slide groove.

7. A method for operating a bridge external prestressed tendon tensioning device, using the bridge external prestressed tendon tensioning device according to any one of claims 1 to 6, characterized in that: include: The bridge external prestressed tendon tensioning device is fixed to the bridge through a frame, with both ends of the prestressed tendon fixed to the bridge and the middle section abutting against the outside of the connecting column; The guide screw receives the power source to rotate and drive the main slider to translate along the axial direction of the guide screw. On the one hand, the main slider drives the auxiliary 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 near the main slider engages with the rack, so that the transmission rod also rotates while it translates, thereby transmitting the torque to the gear at the end of the transmission rod near the auxiliary slider. The gear at this end engages with the rack for transmission, thereby driving the auxiliary slider. The auxiliary slider moves along the sliding guide rail, so that the main slider, auxiliary slider and connecting column move synchronously; The force transmission rod group moves axially along the guide rail screw, thereby driving the prestressed tendons to achieve tensioning and reinforce the bridge.

8. The operating method of the bridge external prestressed tendon tensioning device according to claim 7, characterized in that: A plurality of external prestressed beam tensioning devices for the bridge are arranged on the bridge, and the prestressed beams are sequentially abutted against the driving parts of the plurality of external prestressed beam tensioning devices for the bridge, and the external prestressed beam tensioning devices for the bridge are adjusted respectively to tension the prestressed beams.

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