Pre-pressing device and pre-pressing loading method for hanging basket for cantilever construction bridge support

Abstract

The application provides a pre-pressing device and pre-pressing loading method for a hanging basket for a cantilever construction bridge support, and belongs to the technical field of bridge construction. The pre-pressing device for the hanging basket for the cantilever construction bridge support comprises a telescopic control mechanism, a piston cylinder unit and a pressing unit. The pressing unit comprises a pressing plate, a water storage cavity is arranged on the pressing plate, a plurality of on-off doors are arranged at intervals along the water storage cavity, the on-off doors divide the water storage cavity into a main pre-pressing cavity in the middle and a plurality of auxiliary pre-pressing cavities on both sides, the lower side of the auxiliary pre-pressing cavity is provided with an opening, and the opening is closed through a flexible connecting plate. The piston cylinder unit comprises a vertical cylinder and a piston, and the upper end of the piston is connected to the telescopic control mechanism. The pre-pressing loading method for the hanging basket comprises the following steps: water is introduced into the on-off door, the water enters the auxiliary pre-pressing cavity, the telescopic control mechanism controls the hydraulic cylinder to gradually pressurize the piston, the water in the auxiliary pre-pressing cavity can force the flexible connecting plate at the bottom to expand, and then the flexible connecting plate is in contact with the hanging basket to apply pressure.

Description

Technical Field

[0001] This invention relates to a preloading device and preloading method for a hanging basket used in cantilever bridge construction, belonging to the field of bridge construction technology. Background Technology

[0002] The cantilever construction method using hanging formwork is one of the most commonly used construction methods for large-span prestressed concrete cantilever beams, continuous beams, and rigid frame bridges in the industry. The hanging formwork is the main equipment in cantilever construction, and after installation, it needs to be preloaded to test its reliability, eliminate inelastic deformation, and determine its actual deformation under different loads. Existing bridges vary in size, and the corresponding hanging formwork also differs. However, the area of ​​existing preloading devices cannot be adjusted to suit the bridge's size, resulting in poor adaptability and high design and manufacturing costs. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a preloading device and a preloading method for a hanging basket used in cantilever construction bridge support, which can change the preloading area of ​​the hanging basket according to the actual situation, thus having wider applicability and saving construction costs.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A preloading device for a hanging basket used in cantilever bridge construction includes a telescopic control mechanism, a piston cylinder unit, and a clamping unit. The clamping unit includes a pressure plate, a water storage chamber on the pressure plate along its extension direction, and several on / off gates spaced along the water storage chamber, dividing the water storage chamber into a main preloading chamber in the middle and several secondary preloading chambers on both sides. A boss is formed on the lower side of the main preloading chamber, and an opening is provided on the lower side of the secondary preloading chamber, which is closed by a flexible connecting plate. The piston cylinder unit includes a vertical cylinder and a piston. The vertical cylinder is located on the upper side of the main preloading chamber and communicates with the piston. The piston is slidably and sealed inside the vertical cylinder. The upper end of the piston is connected to the telescopic control mechanism.

[0006] Furthermore, the switch includes a fixed plate, a rotating plate, a central gear, a drive gear, and a motor. The fixed plate has a first through hole eccentrically formed, and the rotating plate has a second through hole eccentrically formed. The fixed plate is fixed to the inside of the water storage chamber. The rotating plate is rotatably and sealably disposed on one side of the fixed plate. The center of the rotating plate is fixedly connected to the central gear. The central gear meshes with the drive gear. The drive gear is driven to rotate by the motor. The rotating plate rotates relative to the fixed plate to align or offset the first through hole and the second through hole.

[0007] Furthermore, the upper side of the pressure plate is provided with an opening groove, and the edge of the central gear extends through the opening groove to the outside of the pressure plate and is connected to the motor. A sealing mechanism is provided between the central gear and the inner wall of the opening groove.

[0008] Furthermore, a sealing groove is provided on the side of the central gear facing the main pre-compression chamber. The sealing mechanism includes a first arc-shaped sealing strip and a second arc-shaped sealing strip. The first arc-shaped sealing strip has a circular cross-section. The second arc-shaped sealing strip has a groove that mates with the first arc-shaped sealing strip. An arc-shaped groove for installing the second arc-shaped sealing strip is provided on the inner wall of the water storage chamber. A conical pressure port is formed between the arc-shaped groove and the back side of the second arc-shaped sealing strip. The second arc-shaped sealing strip presses the first arc-shaped sealing strip tightly within the sealing groove.

[0009] Furthermore, an annular groove is provided on one end face of the fixed plate, and an annular protrusion that mates with the annular groove is provided on the end face of the rotating plate corresponding to the fixed plate.

[0010] Furthermore, the telescopic control mechanism includes a hydraulic cylinder, a horizontal pressure rod, a central support rod, and a vertical pressure rod. The hydraulic cylinder is fixed in the middle of the bridge. The output end of the hydraulic cylinder is hinged to one end of the horizontal pressure rod, and the other end of the horizontal pressure rod is hinged to the vertical pressure rod. The vertical pressure rod is connected to a piston. The middle part of the horizontal pressure rod is hinged to the central support rod, and the central support rod is fixed to the bridge.

[0011] Furthermore, the piston includes a lower housing, an upper housing sealed to the lower housing, and a telescopic device connecting the upper housing and the lower housing. The lower housing is sealed inside a vertical cylinder, and a displacement sensor is provided at the lower end of the lower housing for calibration before pre-pressurization. The displacement sensor is used to detect the height of the lower housing, and the telescopic device adjusts the telescopic amount according to the height of the displacement sensor so that the upper housing is always at the same preset height.

[0012] A preloading method for a formwork hanging basket, utilizing the aforementioned preloading device for a formwork hanging basket used in cantilever bridge construction, includes the following steps:

[0013] Under normal conditions, all on / off valves are closed, and the pressure applied to the water by the piston cannot enter the secondary pre-pressure chamber;

[0014] When it is necessary to increase the pre-compression area, simply open the on / off gate of the corresponding area. Water flows into the on / off gate and enters the secondary pre-compression chamber. The telescopic control mechanism controls the hydraulic cylinder to gradually increase the pressure on the piston. The water in the secondary pre-compression chamber can force the flexible connecting plate at the bottom to expand and then contact the hanging basket to apply pressure.

[0015] The advantages of this invention are:

[0016] 1. The device of the present invention pre-pressurizes the hanging basket by a pressure plate. Under normal conditions, all on / off gates are closed, and the pressure applied to the water by the piston cannot enter the secondary pre-pressurization chamber. At this time, only the boss abuts against the hanging basket, pre-pressurizing the hanging basket over a small area. By gradually increasing the pressure and transmitting the pressure through water, the pressure transmission is more continuous and stable, which can effectively ensure the pre-pressurization effect.

[0017] 2. In the device of the present invention, when it is necessary to increase the pre-compression area, the corresponding on / off gate can be opened. Water flows into the on / off gate and enters the secondary pre-compression chamber. After being gradually pressurized by the piston, the water in the secondary pre-compression chamber can force the flexible connecting plate at the bottom to expand and then contact the hanging basket to apply pressure, thereby increasing the pre-compression area. Therefore, the device of the present invention can change the pre-compression area for the hanging basket according to the actual situation, and has a wider applicability to save construction costs.

[0018] Other advantages, objectives, and features of the invention will be set forth in the following description and will be apparent to those skilled in the art in some respects, or may be learned by practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0020] Figure 1 This is a schematic diagram of the pre-compression device of the present invention;

[0021] Figure 2 for Figure 1 Enlarged view at point A;

[0022] Figure 3 This is a schematic diagram showing the fit between the fixed plate and the rotating plate.

[0023] Figure 4 This is a schematic diagram of the cross-section of the pressure plate;

[0024] Figure 5 This is a structural diagram of the fixed plate;

[0025] Figure 6 This is the front view of the pre-compression device.

[0026] The following are labeled in the attached diagram: 1. Pressure plate, 2. Water storage chamber, 3. Switch valve, 4. Main pre-pressure chamber, 5. Secondary pre-pressure chamber, 6. Boss, 7. Opening, 8. Flexible connecting plate, 9. Vertical cylinder, 10. Piston, 11. Fixed plate, 12. Rotating plate, 13. Central gear, 14. Drive gear, 15. Motor, 16. First through hole, 17. Second through hole, 18. Opening groove, 19. Sealing groove, 20. First arc-shaped sealing strip, 21. Second arc-shaped sealing strip, 22. Embedded groove, 23. Arc-shaped groove, 24. Pressure port, 25. Annular groove, 26. Annular protrusion, 27. Hydraulic cylinder, 28. Horizontal pressure rod, 29. Central support, 30. Vertical pressure rod, 31. Lower housing, 32. Upper housing, 33. Telescopic device. 34. Displacement sensor. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] like Figures 1-6 As shown, a preloading device for a hanging basket used in cantilever bridge construction includes a telescopic control mechanism, a piston cylinder unit, and a clamping unit. The clamping unit includes a pressure plate 1, and a cylindrical water storage chamber 2 is provided on the pressure plate 1 along its extension direction. Several on / off gates 3 are arranged at intervals along the water storage chamber 2, dividing the water storage chamber 2 into a central main preloading chamber 4 and several secondary preloading chambers 5 on both sides. The secondary preloading chambers 5 are arranged sequentially along the longitudinal direction. A boss 6 is formed on the lower side of the main preloading chamber 4. Under normal circumstances, only the boss 6 contacts the hanging basket, and the lower side of the secondary preloading chambers 5 cannot contact the surface of the hanging basket. The lower side of the secondary pre-pressure chamber 5 is provided with an opening 7, which is closed by a flexible connecting plate 8. When water pressure is applied, the flexible connecting plate 8 can expand and contact the hanging basket, so that it can play the role of applying pressure. The flexible connecting plate 8 is made of rubber material. The piston cylinder unit includes a vertical cylinder 9 and a piston 10. The vertical cylinder 9 is located on the upper side of the main pre-pressure chamber 4 and is connected to the main pre-pressure chamber 4. The piston 10 is slidably sealed inside the vertical cylinder 9. The upper end of the piston 10 is connected to the telescopic control mechanism. The telescopic control mechanism can be a conventional telescopic device, such as a hydraulic cylinder or a linear displacement motor.

[0029] In this embodiment, the switch gate 3 includes a fixed plate 11, a rotating plate 12, a central gear 13, a drive gear 14, and a motor 15. The fixed plate 11 has an eccentrically formed first through hole 16, and the rotating plate 12 has an eccentrically formed second through hole 17. The first through hole 16 and the second through hole 17 are the same size. When they are aligned, the valve is opened; when they are misaligned, the valve is closed. The fixed plate 11 is fixed inside the water storage chamber 2. The rotating plate 12 is rotatably and sealably disposed on one side of the fixed plate 11. The center of the rotating plate 12 is fixedly connected to the central gear 13. The central gear 13 meshes with the drive gear 14. The drive gear 14 is driven to rotate by the motor 15. The rotating plate 12 rotates relative to the fixed plate 11 to align or misalign the first through hole 16 and the second through hole 17, thereby opening or closing the valve. Closing by rotation can reduce the influence of water pressure on the valve, making control more convenient and faster.

[0030] In this embodiment, the upper side of the pressure plate 1 is provided with an opening groove 18. The edge of the central gear 13 extends through the opening 7 to the outside of the pressure plate 1 and is connected to the motor 15. A sealing mechanism is provided between the central gear 13 and the inner wall of the opening groove 18. The motor 15 is located on the outside of the pressure plate 1 to facilitate maintenance and replacement and improve the life of the device.

[0031] In this embodiment, a sealing groove 19 is provided on the side of the central gear 13 facing the main pre-compression chamber 4. The sealing mechanism includes a first arc-shaped sealing strip 20 and a second arc-shaped sealing strip 21. The cross-section of the first arc-shaped sealing strip 20 is circular. The second arc-shaped sealing strip 21 has a groove 22 that mates with the first arc-shaped sealing strip 20. The inner wall of the water storage chamber 2 has an arc-shaped groove 23 for installing the second arc-shaped sealing strip 21. A conical pressure port 24 is formed between the arc-shaped groove 23 and the back side of the second arc-shaped sealing strip 21. The second arc-shaped sealing strip 21 presses the first arc-shaped sealing strip 20 into the sealing groove 19, which can achieve a better sealing effect.

[0032] In this embodiment, an annular groove 25 is provided on one end face of the fixed plate 11, and an annular protrusion 26 that cooperates with the annular groove 25 is provided on the end face of the rotating plate 12 corresponding to the fixed plate 11. The fixed plate 11 and the rotating plate 12 are rotatably engaged. An axial limiting device can also be provided between the rotating plate 12 and the inner wall of the pressure plate 1 to stabilize its structure.

[0033] In this embodiment, the telescopic control mechanism includes a hydraulic cylinder 27, a horizontal pressure rod 28, a central support rod 29, and a vertical pressure rod 30. The hydraulic cylinder 27 is fixed in the middle of the bridge. The output end of the hydraulic cylinder 27 is hinged to one end of the horizontal pressure rod 28, and the other end of the horizontal pressure rod 28 is hinged to the vertical pressure rod 30. The vertical pressure rod 30 is connected to the piston 10. The middle part of the horizontal pressure rod 28 is hinged to the central support rod 29, and the central support rod 29 is fixed on the bridge.

[0034] In this embodiment, the piston 10 includes a lower housing 31, an upper housing 32 sealed to the lower housing 31, and a telescopic device 33 connecting the upper housing 32 and the lower housing 31. Both the upper housing 32 and the lower housing 31 are cylindrical. The lower housing 31 is sealed inside the vertical cylinder 9. A displacement sensor 34 is provided at the lower end of the lower housing 31 for calibration before pre-pressing. The displacement sensor 34 is used to detect the height of the lower housing. The telescopic device adjusts the telescopic amount according to the height of the displacement sensor so that the upper housing is always at the same preset height. This allows for more accurate control of the hydraulic cylinder 27 and ensures that the standard of the subsequent pre-pressing process is consistent.

[0035] A preloading method for a formwork hanging basket, utilizing the aforementioned preloading device for a formwork hanging basket used in cantilever bridge construction, includes the following steps:

[0036] Under normal conditions, all on / off valves 3 are closed, and the pressure applied to the water by piston 10 cannot enter the secondary pre-pressure chamber 5;

[0037] When it is necessary to increase the pre-compression area, simply open the corresponding on / off gate 3. Water flows into the on / off gate 3 and enters the secondary pre-compression chamber 5. The telescopic control mechanism controls the hydraulic cylinder 27 to gradually increase the pressure on the piston 10. The water in the secondary pre-compression chamber 5 can force the flexible connecting plate 8 at the bottom to expand and then contact the hanging basket to apply pressure.

[0038] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A preloading device for a hanging basket used in cantilever bridge construction, characterized in that, It includes a telescopic control mechanism, a piston cylinder unit and a pressing unit; the pressing unit includes a pressure plate (1), and a water storage chamber (2) is provided on the pressure plate (1) along the extension direction of the pressure plate (1). Several on / off gates (3) are provided at intervals along the water storage chamber (2). The on / off gates (3) divide the water storage chamber (2) into a main pre-pressurization chamber (4) in the middle and several secondary pre-pressurization chambers (5) on both sides. A boss (6) is formed on the lower side of the main pre-pressurization chamber (4). An opening (7) is provided on the lower side of the secondary pre-pressurization chamber (5). The opening (7) is closed by a flexible connecting plate (8). When water does not enter the secondary pre-pressurization chamber (5), only the boss (6) contacts the hanging basket. The lower side of the secondary pre-pressurization chamber (5) cannot contact the surface of the hanging basket. When water enters the secondary pre-pressurization chamber (5) and pressure is applied, the flexible connecting plate (8) can expand and contact the hanging basket. The piston cylinder unit includes a vertical cylinder (9) and a piston (10). The vertical cylinder (9) is located on the upper side of the main pre-compression chamber (4) and communicates with the main pre-compression chamber (4). The piston (10) is slidably sealed inside the vertical cylinder (9). The upper end of the piston (10) is connected to the telescopic control mechanism. The telescopic control mechanism includes a hydraulic cylinder (27), a horizontal pressure rod (28), a central support rod (29), and a vertical pressure rod (30). The hydraulic cylinder (27) is fixed in the middle of the bridge. The output end of the hydraulic cylinder (27) is hinged to one end of the horizontal pressure rod (28), and the other end of the horizontal pressure rod (28) is hinged to the vertical pressure rod (30). The vertical pressure rod (30) is connected to the piston (10). The middle part of the horizontal pressure rod (28) is hinged to the central support rod (29), and the central support rod (29) is fixed on the bridge. The switch (3) includes a fixed plate (11), a rotating plate (12), a central gear (13), a drive gear (14), and a motor (15). The fixed plate (11) has an eccentric first through hole (16), and the rotating plate (12) has an eccentric second through hole (17). The fixed plate (11) is fixed inside the water storage chamber (2). The rotating plate (12) is rotatably and sealably disposed on one side of the fixed plate (11). The center of the rotating plate (12) is fixedly connected to the central gear (13). The central gear (13) meshes with the drive gear (14). The drive gear (14) is driven to rotate by the motor (15). The rotating plate (12) rotates relative to the fixed plate (11) to achieve alignment or misalignment of the first through hole (16) and the second through hole (17).

2. The preloading device for a hanging basket used in cantilever bridge construction according to claim 1, characterized in that, The upper side of the pressure plate (1) is provided with an opening groove (18), and the edge of the central gear (13) extends through the opening (7) to the outside of the pressure plate (1) and is connected to the motor (15). A sealing mechanism is provided between the central gear (13) and the inner wall of the opening groove (18).

3. The preloading device for a hanging basket used in cantilever bridge construction according to claim 2, characterized in that, A sealing groove (19) is provided on the side of the central gear (13) facing the main pre-compression chamber (4). The sealing mechanism includes a first arc-shaped sealing strip (20) and a second arc-shaped sealing strip (21). The cross-section of the first arc-shaped sealing strip (20) is circular. The second arc-shaped sealing strip (21) has a groove (22) that mates with the first arc-shaped sealing strip (20). The inner wall of the water storage chamber (2) has an arc-shaped groove (23) for installing the second arc-shaped sealing strip (21). A conical pressure port (24) is formed between the arc-shaped groove (23) and the back side of the second arc-shaped sealing strip (21). The second arc-shaped sealing strip (21) presses the first arc-shaped sealing strip (20) into the sealing groove (19).

4. The preloading device for a hanging basket used in cantilever bridge construction according to claim 1, characterized in that, An annular groove (25) is provided on one end face of the fixed plate (11), and an annular protrusion (26) that cooperates with the annular groove (25) is provided on the end face of the rotating plate (12) corresponding to the fixed plate (11).

5. A preloading device for a hanging basket used in cantilever bridge construction according to any one of claims 1-4, characterized in that, The piston (10) includes a lower housing (31), an upper housing (32) sealed to the lower housing (31), and a telescopic device (33) connecting the upper housing (32) and the lower housing (31). The lower housing (31) is sealed inside the vertical cylinder (9). A displacement sensor (34) is provided at the lower end of the lower housing (31) and is calibrated before pre-pressurization. The displacement sensor (34) is used to detect the height of the lower housing (31). The telescopic device (33) adjusts the telescopic amount according to the height of the displacement sensor (34) so ​​that the upper housing (32) is always at the same preset height.

6. A method for preloading a hanging basket, characterized in that, The preloading device for a hanging basket used in cantilever bridge construction as described in any one of claims 1-4 includes the following steps: Under normal conditions, all on / off valves (3) are closed, and the pressure applied to the water by the piston (10) cannot enter the secondary pre-pressure chamber (5); When it is necessary to increase the pre-compression area, simply open the corresponding on / off gate (3). Water flows through the on / off gate (3) and enters the secondary pre-compression chamber (5). The telescopic control mechanism controls the hydraulic cylinder (27) to gradually increase the pressure on the piston (10). The water in the secondary pre-compression chamber (5) can force the flexible connecting plate (8) at the bottom to expand and then contact the hanging basket to apply pressure.

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