Bridge precast hollow box girder formwork system and method of use

Abstract

The application discloses a bridge prefabricated hollow box girder formwork system and a use method, and relates to the technical field of bridge engineering. The formwork system comprises a formwork platform, supporting plates arranged on the two sides of the formwork platform, outer formwork side plate splicing units arranged on the upper ends of the two sides of the formwork platform, an outer formwork bottom plate splicing unit arranged between the two outer formwork side plate splicing units, a plurality of detachable top beams connected between the top ends of the two supporting plates, inner formwork template splicing units connected between the outer formwork bottom plate splicing unit and the detachable top beams, and a formwork removal auxiliary tool. The application is applicable to prefabricated box girders of various sizes and specifications, has low formwork removal difficulty and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, specifically to a precast hollow box girder formwork system for bridges and its application method. Background Technology

[0002] In municipal bridge construction, precast hollow box girders are widely used in bridge superstructure construction due to their advantages such as light weight, good load-bearing performance, and fast construction speed. Factory prefabrication has become the mainstream trend in bridge construction. However, existing hollow box girder precast formwork still faces many technical problems in practical applications, as follows: 1. Poor template versatility: Traditional hollow box girder templates are mostly customized rigid structures. One set of templates can only be used for one type of hollow box girder. When different spans and cross-sectional dimensions of box girders need to be prefabricated in a project, the templates need to be made again, resulting in high template production costs, low turnover efficiency, and waste of materials and costs.

[0003] 2. Difficult and inefficient formwork removal: Traditional formwork removal relies heavily on manual prying and hammering, which is difficult and labor-intensive. It can also cause deformation and damage to the formwork and may damage the already formed box girder concrete, affecting the quality of the box girder. Summary of the Invention

[0004] This invention provides a precast hollow box girder formwork system and its application method for bridges, aiming to solve the problems described in sections 1 and 2 of the background art. This invention is applicable to precast box girders of various sizes and specifications, with low demolding difficulty and high efficiency.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A precast hollow box girder formwork system for bridges includes a formwork platform, support plates on both sides of the formwork platform, outer formwork side plate splicing units on both sides of the upper part of the formwork platform, an outer formwork bottom plate splicing unit between the two outer formwork side plate splicing units, multiple detachable top beams connected between the tops of the support plates on both sides, an inner formwork splicing unit connected between the outer formwork bottom plate splicing unit and the detachable top beams, and demolding auxiliary tools.

[0006] Preferably, multiple linear slide rails are arranged laterally on the left and right sides of the upper part of the mold platform. The outer mold side plate splicing unit includes a slider, a first hydraulic cylinder, and an outer mold side plate support beam slidably connected within the linear slide rails. The bottom end of the outer mold side plate support beam is hinged to a slider, which is slidably connected to the linear slide rails. A plurality of first threaded holes are evenly arranged on the front and rear sides of the linear slide rails in the left and right directions. The front and rear ends of the slider are equipped with positioning holes that mate with the first threaded holes. The slider is fixedly connected to the linear slide rails by fixing bolts passing through the positioning holes and screwed into the first threaded holes. One end of the outer side is fixedly connected to a first hydraulic cylinder along the vertical direction. The piston rod end of the first hydraulic cylinder is hinged to the bottom of the outer mold side plate support beam. The bottom end of the first hydraulic cylinder is detachably fixed to the bottom of the linear slide rail through a fixed seat. The tilt angle of the outer mold side plate support beam is adjusted by extending and retracting the first hydraulic cylinder. The distance between the outer mold side plate support beams on both sides is adjusted by moving the position of the first hydraulic cylinder. The outer mold side plate support beam is equipped with several outer mold side plate assembly segments. Each outer mold side plate assembly segment is set along the entire length in the front-back direction. A first slot is opened on the lower surface of the outer mold side plate assembly segment to engage with the outer mold side plate support beam.

[0007] Preferably, the outer mold side plate assembly segments are provided in several models according to the difference in width, wherein the lower end of the outer mold side plate assembly segment near the bottom is provided with a horizontal surface; the outer mold side plate support beam is a round rod structure, and the round rod structure is provided with external threads and equipped with limit nuts.

[0008] Preferably, the outer mold base plate splicing unit includes a fixed outer mold base plate located in the middle between the two outer mold side plate splicing units. The two sides of the lower end of the fixed outer mold base plate are fixedly connected to the mold table via support columns. Multiple staggered second hydraulic cylinders are connected to the fixed outer mold base plate. The upper and lower ends of the cylinder barrels of the second hydraulic cylinders are respectively embedded in the mold table and the fixed outer mold base plate. The piston rods of the second hydraulic cylinders extend vertically upward. Multiple outer mold base plate support beams are distributed on both sides of the fixed outer mold base plate. One end of each outer mold base plate support beam is fixedly connected to the fixed outer mold base plate, and the other end is fixedly connected to a support block. The bottom end of the support block is fixedly connected to the mold table. The outer mold base plate support beams are configured with outer mold base plate assembly segments of various sizes and models. The bottom end of each outer mold base plate assembly segment is provided with several second slots that cooperate with the outer mold base plate support beams. The outermost outer end of the outer mold base plate assembly segment is provided with an inclined surface that matches the slope of the outer mold side plate support beam.

[0009] Preferably, the inner mold template splicing unit includes an inner mold top plate splicing sub-unit located on the upper side, an inner mold bottom plate splicing sub-unit located on the lower side, and an inner mold side plate splicing sub-unit connecting the inner mold top plate splicing sub-unit and the inner mold bottom plate splicing sub-unit on the same side; the inner mold top plate splicing sub-unit includes a fixed inner mold top plate located in the middle, and several inner mold top plate assembly segments connected to both sides of the fixed inner mold top plate; the inner mold bottom plate splicing sub-unit includes a fixed inner mold bottom plate located in the middle and inner mold bottom plate assembly segments connected to both sides of the fixed inner mold bottom plate.

[0010] Preferably, the detachable top beam has a plurality of first connecting holes evenly distributed along its length. The two ends of the detachable top beam are fixedly connected to the top of the support plate by high-strength bolts passing through the first connecting holes. The detachable top beam is connected to the inner mold top plate splicing sub-unit by multiple tie-down demolding screws passing through the first connecting holes. The piston rod of the second cylinder has a second threaded hole along its axial direction at its top. The fixed inner mold bottom plate has a second connecting hole opposite to the second threaded hole. The piston rod of the second cylinder is fixedly connected to the fixed inner mold bottom plate by connecting bolts passing through the second connecting hole and screwed to the second threaded hole.

[0011] Preferably, the fixed inner mold base plate has several high-strength threaded rods arranged in the left-right direction on both sides. One end of each threaded rod is screwed into a pre-set third threaded hole on the side of the fixed inner mold base plate. The length of the threaded rod can be adjusted by rotating it. The threaded rods on the left and right sides are staggered. Each threaded rod is equipped with an inner mold base plate assembly segment of various sizes for use with it. Each inner mold base plate assembly segment has several third connecting holes that pass through in the left-right direction. The outer end of each third connecting hole is enlarged to form a countersunk hole. The threaded rod passes through the third connecting hole and locks one or more inner mold base plate assembly segments to both sides of the fixed inner mold base plate.

[0012] Preferably, the fixed inner mold top plate has several sliding rods arranged on both sides in the left-right direction. One end of each sliding rod is slidably connected to a sliding hole on the side of the fixed inner mold top plate, and the other end is fixedly connected to the outer inner mold top plate. One or more quick-release sliding rod segments are provided on the sliding rod between the outer inner mold top plate and the fixed inner mold top plate. A limiting block is provided on the quick-release sliding rod segment closest to the fixed inner mold top plate. Each quick-release sliding rod segment is equipped with a quick-release inner mold top plate assembly segment, and the top of the quick-release inner mold top plate assembly segment is equipped with a third slot that mates with the quick-release sliding rod segment. The top of both the fixed inner mold top plate and the outer inner mold top plate are provided with a fourth threaded hole. The internal thread of the fourth threaded hole is of high... Made of high-strength steel, the quick-release inner mold top plate assembly segment is provided with a fourth connecting hole that runs vertically through the top and bottom. The pull-out mold release screw includes a high-strength screw body with a striking block at the top. A first limiting plate is screwed to the upper part of the screw body. Part of the screw body is used in conjunction with the fourth threaded hole, and the lower end of the remaining screw body passes through the fourth connecting hole and is screwed with a second limiting plate. The upper end of the second limiting plate abuts against the quick-release inner mold top plate assembly segment. A third limiting plate is screwed to the screw body at the upper end of the quick-release inner mold top plate assembly segment. The bottom end of the third limiting plate is fixedly connected to the top end of the quick-release inner mold top plate assembly segment. The lower end of the first limiting plate abuts against the detachable top beam.

[0013] Preferably, the inner mold side plate splicing subunit includes a lower inner mold side plate and an upper inner mold side plate. Several jacks are evenly arranged along the front-to-back direction on the lower inner mold side plate. The piston rods of the jacks are connected to pull rods. The jacks are embedded in pre-set mounting grooves in the lower inner mold side plate. The piston rods and pull rods of the jacks pass through the groove wall facing the upper inner mold side plate and are fixedly connected to the upper inner mold side plate through the ends of the pull rods. Several quick-release side templates are arranged on the pull rods between the lower and upper inner mold side plates. The quick-release side templates are fixedly connected to each other and to the adjacent upper or lower side plates of the inner mold by positioning bolts. The quick-release side templates are available in several sizes and models. The outer surface of the quick-release side templates is provided with a fourth slot that matches the size and shape of the tie rod. The inner surfaces of the upper and lower side plates of the inner mold are respectively welded with connecting plates for engaging with the bottom end of the outer top plate of the inner mold or the top end of the assembly segment of the inner mold bottom plate. The connecting plates are fixedly connected to the corresponding assembly segment of the outer top plate or the inner mold bottom plate by bolts.

[0014] Preferably, the demolding auxiliary tool includes: a U-shaped frame, rollers, wheels, electric cylinders, and pressure feet. The U-shaped frame includes a large U-shaped frame and a small U-shaped frame arranged internally and externally. The opening ends of the large and small U-shaped frames face the same direction and are connected and fixed by several crossbars. Rollers are rotatably connected to the crossbars. Two wheels are installed on each side of the U-shaped frame. Multiple electric cylinders are connected laterally to the side walls of the U-shaped frame. The fixed end of the electric cylinder is fixedly connected to the U-shaped frame, and the telescopic end is connected to the pressure foot. The electric cylinders are electrically connected to a power source via a control panel and cables.

[0015] A method for using a precast hollow box girder formwork system for bridges, including a method for formwork installation and a method for formwork removal; The template installation method includes the following steps: S11: According to the design dimensions of the outer mold side plate, fix the first oil cylinders on both sides in the set position and extend the first oil cylinders to the set height. At this time, the outer mold side plate support beam is located at the designed inclination angle and the outer mold side plate support beams on both sides are located at the set distance. Fix the slider to the linear slide rail. S12: Assemble the outer mold base plate assembly segments on the outer mold base plate support beams on both sides of the fixed outer mold base plate; make the inclined surface of the outermost outer mold base plate assembly segment abut against the outer mold side plate support beam; seal the adjacent outer mold base plate assembly segments and the outer mold base plate assembly segments with the fixed outer mold base plate through rubber gaskets. S13: Assemble the outer mold side plate assembly segments on the outer mold side plate support beam, wherein the horizontal plane of the bottom outer mold side plate assembly segment abuts against the top of the outermost outer mold bottom plate assembly segment. After reaching the design height, lock each outer mold side plate assembly segment with limit nuts; wherein, rubber gaskets are used to seal between adjacent outer mold side plate assembly segments and between outer mold side plate assembly segments and outer mold bottom plate assembly segments. S14: Connect and fix the fixed inner mold base plate to the second oil cylinder with connecting bolts, and raise the second oil cylinder to the set height; install the required number of inner mold base plate assembly segments on both sides of the fixed inner mold base plate so that the inner mold base plate reaches the design length; S15: Connect the fixed inner mold top plate by pulling the demolding screw, so that the outer top plate of the inner mold moves outward to a set distance, and connect and fix the outer top plate of the inner mold by pulling the demolding screw. Install the quick-release inner mold top plate assembly segment and connect the corresponding pulling demolding screw. Adjust the position of the first limit plate so that the inner mold top plate assembly sub-unit is at the required height. S16: Fix the lower side plate and upper side plate of the inner mold to the corresponding outer top plate or bottom plate of the inner mold using bolts, and install the required number of quick-release side templates. S17: Seal both ends of the template system using end templates; The demolding method includes: S21: After the box girder is formed and reaches the design strength, first remove the end formwork, then remove the quick-release inner formwork top plate assembly segment and quick-release side formwork. S22: Move the first limiting plate upward and use a rubber hammer to strike the block to loosen the contact surface between the fixed inner mold top plate, the outer inner mold top plate and the concrete. S23: Remove all tie rods and demolding bolts, start each jack to pull down the upper side plate of the inner mold, and complete the demolding of the upper side plate of the inner mold. During the downward movement of the upper side plate of the inner mold, the outer top plate of the inner mold moves towards the side of the fixed inner mold top plate; when the limit block abuts against the side end of the fixed inner mold top plate, the upper side plate of the inner mold abuts against the concrete surface, and the jacks stop. S24: Start the second hydraulic cylinder to lift the inner mold bottom plate splicing sub-unit upward, so that the inner mold bottom plate splicing sub-unit is loosened from the concrete contact surface; S25: Remove the connecting bolts to retract the second hydraulic cylinder, start the jack to lift the splicing sub-unit of the inner mold lower side plate and the inner mold bottom plate, and complete the demolding of the inner mold lower side plate; S26: Start the extension of the second hydraulic cylinder to lift the inner mold template splicing unit to a set height, then insert the demolding auxiliary tool to extend the electric cylinders on both sides of the demolding auxiliary tool, and press the pressure foot connected to the end of the electric cylinder to the inner wall of the box girder. The second hydraulic cylinder retracts and places the inner mold template splicing unit on the top of the roller of the demolding auxiliary tool. The inner mold template splicing unit is then pulled out as a whole by the dragging device. S27: The first hydraulic cylinder shortens, pulling the outer mold side plate support beam outward, and dismantling each outer mold side plate assembly segment in sequence; the vibrator inside the mold table is started to loosen the contact surface between the outer mold bottom plate splicing unit and the concrete. S28: Remove the detachable top beam, use a crane to lift the box girder segments to other construction locations, and remove the outer formwork bottom plate to assemble the segments.

[0016] The present invention provides a precast hollow box girder formwork system and its application method for bridges, which has the following beneficial effects: This invention is applicable to the prefabrication of box girders of various sizes and models, greatly improving the versatility of the molds, reducing mold usage costs, and avoiding the problems of high costs, idle molds, and even waste caused by purchasing multiple sets of molds. At the same time, while improving versatility, this invention also maximizes demolding efficiency, reduces the labor intensity of manual demolding, and avoids damage to the box girder components. Attached Figure Description

[0017] Figure 1 A front view of the present invention without the outer mold assembled; Figure 2 A front view structural diagram of the assembly of the outer mold of this invention; Figure 3 A top view of the present invention without the inner mold installed and without the outer mold assembled; Figure 4 This invention Figure 3 Top view of the structure after removing the detachable top beam; Figure 5 A top view of the structure of the present invention when the inner mold is installed; Figure 6 This invention Figure 5 Top view of the structure after removing the detachable top beam; Figure 7 A top view schematic diagram of the quick-release inner mold top plate assembly segment of the present invention; Figure 8 A side view of the inner mold side plate splicing subunit of the present invention; Figure 9 A cross-sectional schematic diagram of the connection structure of the inner mold side plate splicing subunit of the present invention; Figure 10 A cross-sectional schematic diagram of the rubber sleeve covering the pull rod of the present invention; Figure 11 A top view of the main structure of the fixed inner mold top plate of the present invention; Figure 12 Top view schematic diagram of the main structure of the fixed inner mold base plate of the present invention; Figure 13 Schematic diagram of the inner mold demolding stage of this invention Figure 1 ; Figure 14 Schematic diagram of the inner mold demolding stage of this invention Figure 2 ; Figure 15 Schematic diagram of the inner mold demolding stage of this invention Figure 3 ; Figure 16 Top view of the demolding aid tool of this invention; Figure 17 A front view schematic diagram of the demolding aid tool of this invention.

[0018] In the diagram: 1. Mold platform; 2. Outer mold side plate support beam; 3. First hydraulic cylinder; 4. Support plate; 5. Diagonal brace; 6. Fixed outer mold base plate; 7. Fixed inner mold base plate; 71. Threaded rod; 8. Second hydraulic cylinder; 9. Inner mold base plate assembly segment; 10. Inner mold lower side plate; 101. Jack; 102. Mounting groove; 103. Tie rod; 104. Rubber sleeve; 11. Inner mold upper side plate; 12. Quick-release side template; 121. Positioning bolt; 13. Fixed inner mold top plate; 14. Quick-release inner mold top plate assembly segment; 14. Third slot; 141. Fourth connecting hole; 142. Side edge plate; 143. Inner mold outer side top plate; 15. Tie-and-release mold release screw A; 16. Tie-and-release mold release screw B; 17. Second limiting plate 171; First limiting plate 172; Striking block 173; Detachable top beam 18; First connecting hole 181; Outer mold bottom plate support beam 19; Connecting plate 20; Outer mold side plate assembly segment 21; Outer mold bottom plate assembly segment 22; Support block 23; Linear slide rail 24; First threaded hole 241; Fixed seat 242; Slider 25; Slide rod 26; Limiting block 261; Quick-release slide rod segment 262; Slide rod segment 263 connected to the outer top plate of the inner mold; Large U-shaped frame 27; Small U-shaped frame 28; End crossbar 29; Crossbar 30; Roller 31; Traveling wheel 32; Electric cylinder 33; Presser foot 34; Tension spring 35.

[0019] It should be noted that the above figures are all schematic diagrams and the size ratios between the various structures of the present invention should not be understood based on the scale relationships shown in the figures. The actual size ratios should be set as needed. Detailed Implementation

[0020] The following description provides a detailed explanation of the embodiments of the present invention in a step-by-step manner. This description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limiting this invention.

[0022] Example 1: A precast hollow box girder formwork system for bridges, such as Figure 1-17As shown, it includes a mold platform 1, support plates 4 on both sides of the mold platform 1, outer mold side plate splicing units (for splicing outer mold side plates) on both sides of the upper end of the mold platform 1, outer mold bottom plate splicing unit (for splicing outer mold bottom plate) between the two outer mold side plate splicing units, multiple detachable top beams 18 connected between the tops of the two support plates, inner mold template splicing unit connected between the outer mold bottom plate splicing unit and the detachable top beams, and demolding auxiliary tools (for assisting in pulling out the inner mold template splicing unit).

[0023] Example 2: like Figure 1 , 2 As shown in Figures 3 and 4, multiple linear slide rails 24 are arranged laterally on the left and right sides of the upper end of the mold table 1. The outer mold side plate splicing unit includes a slider 25 slidably connected within the linear slide rails 24, a first hydraulic cylinder 3, and an outer mold side plate support beam 2. The bottom end of the outer mold side plate support beam 2 is hinged to the slider 25. The slider 25 is slidably connected to the linear slide rails 24. Several first threaded holes 241 are evenly arranged on the front and rear sides of the linear slide rails 24 in the left and right directions. The front and rear ends of the slider 25 are equipped with positioning holes (not marked in the figure) that cooperate with the first threaded holes. The slider 25 is fixedly connected to the linear slide rails 24 by fixing bolts that pass through the positioning holes and are screwed into the first threaded holes 241. A first hydraulic cylinder 3 is vertically fixedly connected to one end of the outer side of the linear slide rail 24. The piston rod end of the first hydraulic cylinder 3 is hinged to the bottom of the outer mold side plate support beam 2. The bottom end of the first hydraulic cylinder 3 is detachably fixedly connected to the bottom of the linear slide rail 24 via a fixed seat 242. The tilt angle of the outer mold side plate support beam 2 is adjusted by extending and retracting the first hydraulic cylinder 3. The distance between the outer mold side plate support beams 2 on both sides is adjusted by moving the position of the first hydraulic cylinder 3. The outer mold side plate support beam 2 is equipped with several outer mold side plate assembly segments 21. Each outer mold side plate assembly segment 21 is arranged along the entire length in the front-to-back direction. A first slot (not shown in the figure) is opened on the lower surface of the outer mold side plate assembly segment 21 to engage with the outer mold side plate support beam 2. Figure 7 As shown, the first slot at the bottom is used to lock onto the outer template support beam 2, and multiple outer template side plate assembly segments 21 are snapped together to form the outer template.

[0024] like Figure 1-4 As shown, the outer mold side plate assembly segment 21 has several models with different widths. Among them, the lower end of the outer mold side plate assembly segment 21 near the bottom has a horizontal surface (see...). Figure 2 The outer mold side plate support beam 2 is a round rod structure, with external threads and limit nuts (such as...) on the round rod structure. Figure 2 As shown in the figure (not marked), it is used to fasten and splice the various outer mold side plate assembly segments 21.

[0025] Example 3: like Figure 1-4 As shown in Figure 12, the outer mold base plate splicing unit includes a fixed outer mold base plate 7 located in the middle between the two outer mold side plate splicing units. The two sides of the lower end of the fixed outer mold base plate 7 are respectively supported by support columns (such as...). Figure 1 , 2 As shown in the figure (not marked), it is fixedly connected to the mold table 1. Multiple staggered second hydraulic cylinders 8 are connected to the fixed outer mold base plate 7. The upper and lower ends of the cylinder barrels of the second hydraulic cylinders 8 are respectively embedded inside the mold table 1 and the fixed outer mold base plate 7. The piston rods of the second hydraulic cylinders 8 extend vertically upwards. Multiple outer mold base plate support beams 19 are distributed on both sides of the fixed outer mold base plate 7. One end of each outer mold base plate support beam 19 is fixedly connected to the fixed outer mold base plate 7, and the other end is fixedly connected to a support block 23. The bottom end of the support block 23 is fixedly connected to the mold table 1. The outer mold base plate support beams 19 are equipped with various sizes and models of outer mold base plate assembly segments 22. The bottom end of each outer mold base plate assembly segment 22 has several second slots that cooperate with the outer mold base plate support beams. The outermost outer end of the outer mold base plate assembly segment 22 has an inclined surface with the same slope as the outer mold base plate support beam 2. Figure 2 As shown, when the inclined surface cooperates with the outer mold side plate support beam 2, it can prevent the outer mold bottom plate assembly segment from loosening. At the same time, the back of the outer mold side plate support beam 2 abuts against the support plate 4, and the support plate bears the weight of the outer mold side plate. Its structure can refer to the existing technology support plate system.

[0026] Example 4: like Figure 1-12 As shown, the inner mold template splicing unit includes an inner mold top plate splicing sub-unit located on the upper side, an inner mold bottom plate splicing sub-unit located on the lower side, and an inner mold side plate splicing sub-unit connecting the inner mold top plate splicing sub-unit and the inner mold bottom plate splicing sub-unit on the same side; the inner mold top plate splicing sub-unit includes a fixed inner mold top plate 13 located in the middle, and several inner mold top plate assembly segments connected to both sides of the fixed inner mold top plate 13; the inner mold bottom plate splicing sub-unit includes a fixed inner mold bottom plate 7 located in the middle and inner mold bottom plate assembly segments 9 connected to both sides of the fixed inner mold bottom plate 7.

[0027] like Figure 3As shown, the detachable top beam 18 has a plurality of first connecting holes 181 evenly distributed along its length. The two ends of the detachable top beam 18 are fixedly connected to the top of the support plate 4 by high-strength bolts passing through the first connecting holes. The detachable top beam 18 is connected to the inner mold top plate splicing subunit by multiple tie-down demolding screws 16 / 17 passing through the first connecting holes. The piston rod of the second cylinder 8 has a second threaded hole along its axial direction at its top end. The fixed inner mold bottom plate 7 has a second connecting hole opposite to the second threaded hole. The piston rod of the second cylinder 8 is fixedly connected to the fixed inner mold bottom plate 7 by connecting bolts passing through the second connecting hole and screwed to the second threaded hole.

[0028] like Figure 12 As shown, the fixed inner mold base plate 7 has several high-strength threaded rods 71 ​​arranged along the left-right direction on both sides. One end of each threaded rod 71 is screwed into a pre-set third threaded hole (not shown in the figure) on the side end of the fixed inner mold base plate 7. The length of the threaded rod 71 can be adjusted by rotating it. The threaded rods 71 ​​on the left and right sides are staggered. Each threaded rod 71 is equipped with an inner mold base plate assembly segment 9 of various sizes for use with it. The inner mold base plate assembly segment 9 has several third connecting holes (not shown in the figure) that pass through in the left-right direction. The outer end of the third connecting hole is enlarged to form a countersunk hole (a common structure, not shown in the figure). The threaded rods 71 ​​pass through the third connecting holes and lock one or more inner mold base plate assembly segments 9 to both sides of the fixed inner mold base plate. It should be noted that, since this invention is an assembly structure, all gaps can be sealed to ensure the sealing of the mold.

[0029] like Figure 1-11 As shown, several sliding rods 26 arranged along the left-right direction are arranged on both sides of the fixed inner mold top plate 13. One end of each sliding rod 26 is slidably connected to a sliding hole on the side of the fixed inner mold top plate 13, and the other end is fixedly connected to the outer inner mold top plate 15. One or more quick-release sliding rod segments 262 are provided on the sliding rod between the outer inner mold top plate 15 and the fixed inner mold top plate 13. A limiting block 261 is provided on the quick-release sliding rod segment 262 closest to the fixed inner mold top plate. The quick-release sliding rod segment is equipped with a quick-release inner mold top plate assembly segment 14, such as... Figure 7As shown, the top of the quick-release inner mold top plate assembly segment 14 is equipped with a third slot 141 that mates with the quick-release sliding rod segment 262; the top of the fixed inner mold top plate 13 and the top of the outer inner mold top plate 15 are both provided with a fourth threaded hole (not shown in the figure). The internal thread of the fourth threaded hole is made of high-strength steel. The quick-release inner mold top plate assembly segment 14 is provided with a fourth connecting hole 142 that runs vertically through the upper and lower parts. The pull-out mold release screw includes a high-strength screw body. The top of the screw body is provided with a striking block 173. A first limiting plate 172 is screwed onto the upper part of the screw body. Part of the screw body is used in conjunction with the fourth threaded hole. The lower end of the remaining screw body passes through the fourth connecting hole and is screwed with a second limiting plate 171. The upper end of the second limiting plate 171 abuts against the quick-release inner mold top plate assembly segment 14. A third limiting plate (e.g., ...) is screwed onto the screw body at the upper end of the quick-release inner mold top plate assembly segment 14. Figure 1 As shown in the figure (not marked), the bottom end of the third limiting plate is fixedly connected to the top end of the quick-release inner formwork top plate assembly segment 14, and the lower end of the first limiting plate 172 abuts against the detachable top beam 18. When dismantling the formwork, rotating the first limiting plate upwards and then striking the striking block allows the quick-release inner formwork top plate assembly segment 14 to quickly detach from the concrete contact surface, achieving rapid formwork dismantling; (refer to...) Figure 10 As shown, the third slot 141 can cooperate with the quick-release slide bar segment 262 through the rubber sleeve 104, which can achieve a sealing effect and effectively protect the quick-release slide bar segment 262. The rest of the similar structures are analogous.

[0030] like Figure 1-12 As shown, the inner mold side plate splicing subunit includes a lower inner mold side plate 10 and an upper inner mold side plate 11. Several jacks 101 are evenly arranged along the front-to-back direction on the lower inner mold side plate 10. A pull rod 103 is connected to the piston rod end of each jack 101. The jacks 101 are embedded in a pre-set mounting groove 102 in the lower inner mold side plate 10. The piston rod and pull rod of the jacks 101 pass through the groove wall facing the upper inner mold side plate 11 and are fixedly connected to the upper inner mold side plate 11 through the end of the pull rod 103. Several quick-release side templates 12 are arranged on the pull rod 103 between the lower inner mold side plate 10 and the upper inner mold side plate 11. The quick-release side templates 12 are fixedly connected to each other and to adjacent upper inner mold side plates 11 or lower inner mold side plates 10 by positioning bolts. Figure 9 As shown, the quick-release side template 12 is available in several sizes, and the outer surface of the quick-release side template 12 is provided with a fourth slot that matches the size and shape of the pull rod 103, such as... Figure 10Subsequently, the fourth slot is connected to the pull rod 103 via a rubber sleeve 104. Connecting plates 20 (which can be used for temporary welding) are welded to the inner surfaces of the upper side plate 11 and the lower side plate 10 of the inner mold, respectively, to mate with the bottom end of the outer top plate 15 of the inner mold or the top end of the assembly segment of the inner mold bottom plate. These connecting plates are fixedly connected to the corresponding outer top plate 15 of the inner mold or the assembly segment of the inner mold bottom plate via bolts. Figure 1 As shown. When removing the quick-release side template 12, it is necessary to unscrew the positioning bolts that fix it, and then pull the handle on its surface outward. Since the fourth slot is located on the outside, it will not be constrained by the pull rod.

[0031] Example 5: like Figure 16 , 17 As shown, the demolding auxiliary tool includes: a U-shaped frame, rollers 31, traveling wheels 32, electric cylinders 33, and pressure feet 34. The U-shaped frame includes a large U-shaped frame 27 and a small U-shaped frame 28 arranged inside and outside. The opening ends of the large U-shaped frame 27 and the small U-shaped frame 28 face the same direction and are connected and fixed by several crossbars 30. Rollers 31 are rotatably connected to the crossbars 30. Two traveling wheels 32 are installed on each side of the U-shaped frame. Multiple electric cylinders 33 are connected laterally on both side walls of the U-shaped frame. The fixed end of the electric cylinder 33 is fixedly connected to the U-shaped frame, and the telescopic end is connected to the pressure feet 34. The electric cylinders are electrically connected to a power source through a control panel and cables. The U-shaped frame is designed to avoid the piston rod of the second hydraulic cylinder when inserted into the inner hole of the box girder. The electric cylinder drives the pressure feet to abut against the side wall of the inner hole of the box girder, thereby fixing the demolding auxiliary tool. The rollers are used to contact the bottom of the inner mold, so that the reduced inner mold can be removed as a whole by pulling.

[0032] Example 6: Based on the above embodiments, this embodiment discloses a method for using a precast hollow box girder formwork system for bridges, such as... Figure 1-17 As shown, this includes methods for installing and removing the template; The template installation method includes the following steps: S11: According to the design dimensions of the outer mold side plate, fix the first oil cylinders on both sides in the set position and extend the first oil cylinders to the set height. At this time, the outer mold side plate support beam is located at the designed inclination angle and the outer mold side plate support beams on both sides are located at the set distance. Fix the slider to the linear slide rail. S12: Assemble the outer mold base plate assembly segments on the outer mold base plate support beams on both sides of the fixed outer mold base plate; make the inclined surface of the outermost outer mold base plate assembly segment abut against the outer mold side plate support beam; seal the adjacent outer mold base plate assembly segments and the outer mold base plate assembly segments with the fixed outer mold base plate through rubber gaskets. S13: Assemble the outer mold side plate assembly segments on the outer mold side plate support beam, wherein the horizontal plane of the bottom outer mold side plate assembly segment abuts against the top of the outermost outer mold bottom plate assembly segment. After reaching the design height, lock each outer mold side plate assembly segment with limit nuts; wherein, rubber gaskets are used to seal between adjacent outer mold side plate assembly segments and between outer mold side plate assembly segments and outer mold bottom plate assembly segments. S14: Connect and fix the fixed inner mold base plate to the second oil cylinder with connecting bolts, and raise the second oil cylinder to the set height; install the required number of inner mold base plate assembly segments on both sides of the fixed inner mold base plate so that the inner mold base plate reaches the design length; S15: Connect the fixed inner mold top plate by pulling the demolding screw, so that the outer top plate of the inner mold moves outward to a set distance, and connect and fix the outer top plate of the inner mold by pulling the demolding screw. Install the quick-release inner mold top plate assembly segment and connect the corresponding pulling demolding screw. Adjust the position of the first limit plate so that the inner mold top plate assembly sub-unit is at the required height. S16: Fix the lower side plate and upper side plate of the inner mold to the corresponding outer top plate or bottom plate of the inner mold using bolts, and install the required number of quick-release side templates. S17: Seal both ends of the template system with end templates (this is a common technique, which can be achieved by bolt connection to prevent grout leakage at the front and rear ends of the template system). The demolding method includes: S21: After the box girder is formed and reaches the design strength, first remove the end formwork, and then remove the quick-release inner formwork top plate assembly segment and quick-release side formwork. S22: Move the first limiting plate upward and use a rubber hammer to strike the block to loosen the contact surface between the fixed inner mold top plate, the outer inner mold top plate and the concrete. S23: Remove all tie rods and demolding bolts, start all jacks, and pull down the upper side plate of the inner mold to complete the demolding of the upper side template of the inner mold. During the downward movement of the upper side plate of the inner mold, the outer top plate of the inner mold moves towards the side of the fixed inner mold top plate. When the limit block abuts against the side end of the fixed inner mold top plate, the upper side template of the inner mold abuts against the concrete surface, and the jacks are stopped. S24: Start the second hydraulic cylinder to lift the inner mold bottom plate splicing sub-unit upward, so that the inner mold bottom plate splicing sub-unit is loosened from the concrete contact surface; S25: Remove the connecting bolts to retract the second hydraulic cylinder, start the jack to lift the splicing sub-unit of the inner mold lower side plate and the inner mold bottom plate, and complete the demolding of the inner mold lower side plate; S26: Start the extension of the second hydraulic cylinder to lift the inner mold template splicing unit to a set height, then insert the demolding auxiliary tool to extend the electric cylinders on both sides of the demolding auxiliary tool, and press the pressure foot connected to the end of the electric cylinder to the inner wall of the box girder. The second hydraulic cylinder retracts and places the inner mold template splicing unit on the top of the roller of the demolding auxiliary tool. The inner mold template splicing unit is then pulled out as a whole by the dragging device. S27: The first hydraulic cylinder shortens, pulling the outer mold side plate support beam outward, and dismantling each outer mold side plate assembly segment in sequence; the vibrator inside the mold table is started to loosen the contact surface between the outer mold bottom plate splicing unit and the concrete. S28: Remove the detachable top beam, use a crane to lift the box girder segments to other construction locations, and remove the outer formwork bottom plate to assemble the segments.

Claims

1. A precast hollow box girder formwork system for bridges, characterized in that: it includes a formwork platform, support plates on both sides of the formwork platform, outer formwork side plate splicing units on both sides of the upper end of the formwork platform, an outer formwork bottom plate splicing unit between the two outer formwork side plate splicing units, multiple detachable top beams connected between the top ends of the support plates on both sides, an inner formwork splicing unit connected between the outer formwork bottom plate splicing unit and the detachable top beams, and demolding auxiliary tools.

2. The precast hollow box girder template system for bridges as described in claim 1, characterized in that: multiple linear slide rails are arranged horizontally on the left and right sides of the upper end of the template platform, and the outer template side plate splicing unit includes a slider, a first oil cylinder, and an outer template side plate support beam that are slidably connected in the linear slide rails, and the bottom end of the outer template side plate support beam is hinged to a slider. The slider is slidably connected to the linear slide rail. The linear slide rail has several first threaded holes evenly arranged on its front and rear sides along the left and right directions. The slider is equipped with positioning holes that cooperate with the first threaded holes at its front and rear ends. The slider is fixedly connected to the linear slide rail by fixing bolts that pass through the positioning holes and are screwed into the first threaded holes. A first hydraulic cylinder is fixedly connected to one end of the outer side of the linear slide rail along the vertical direction. The piston rod end of the first oil cylinder is hinged to the bottom of the outer mold side plate support beam. The bottom end of the first oil cylinder is detachably fixed to the bottom of the linear slide rail through a fixed seat. The tilt angle of the outer mold side plate support beam is adjusted by extending and retracting the first oil cylinder. The distance between the outer mold side plate support beams on both sides is adjusted by moving the position of the first oil cylinder. The outer mold side plate support beam is equipped with several outer mold side plate assembly segments. Each outer mold side plate assembly segment is set along the entire length in the front-to-back direction. A first slot is opened on the lower surface of the outer mold side plate assembly segment to engage with the outer mold side plate support beam.

3. The precast hollow box girder formwork system for bridges as described in claim 2, characterized in that: The outer mold side plate assembly segments are available in several models depending on their width. Among them, the lower end of the outer mold side plate assembly segment closest to the bottom has a horizontal surface. The outer mold side plate support beam is a round rod structure with external threads and a limit nut.

4. The precast hollow box girder formwork system for bridges as described in claim 3, characterized in that: The outer mold base plate splicing unit includes a fixed outer mold base plate located in the middle between the two outer mold side plate splicing units. The two sides of the lower end of the fixed outer mold base plate are fixedly connected to the mold table by support columns. Multiple staggered second oil cylinders are connected to the fixed outer mold base plate. The upper and lower ends of the cylinder of the second cylinder are respectively embedded in the mold table and the fixed outer mold base plate. The piston rod of the second cylinder extends vertically upward. Multiple outer mold base plate support beams are distributed on both sides of the fixed outer mold base plate. One end of the outer mold base plate support beam is fixedly connected to the fixed outer mold base plate, and the other end is fixedly connected to a support block. The bottom end of the support block is fixedly connected to the mold table. The outer mold base plate support beam is equipped with outer mold base plate assembly segments of various sizes and models. The bottom end of the outer mold base plate assembly segment is provided with several second slots that cooperate with the outer mold base plate support beam. The outermost outer end of the outer mold base plate assembly segment is provided with an inclined surface that is consistent with the slope of the outer mold base plate support beam.

5. The precast hollow box girder formwork system for bridges as described in claim 4, characterized in that: The inner mold template splicing unit includes an inner mold top plate splicing sub-unit located on the upper side, an inner mold bottom plate splicing sub-unit located on the lower side, and an inner mold side plate splicing sub-unit connected between the inner mold top plate splicing sub-unit and the inner mold bottom plate splicing sub-unit on the same side. The inner mold top plate splicing subunit includes a fixed inner mold top plate located in the middle and several inner mold top plate assembly segments connected to both sides of the fixed inner mold top plate; the inner mold bottom plate splicing subunit includes a fixed inner mold bottom plate located in the middle and inner mold bottom plate assembly segments connected to both sides of the fixed inner mold bottom plate.

6. The precast hollow box girder formwork system for bridges as described in claim 5, characterized in that: The detachable top beam has several first connecting holes evenly distributed along its length, and both ends of the detachable top beam are fixedly connected to the top of the support plate by high-strength bolts passing through the first connecting holes. The detachable top beam is connected to the inner mold top plate splicing subunit by multiple tie-down demolding screws passing through the first connecting hole. The piston rod of the second cylinder is provided with a second threaded hole along the axial direction at its top end. The fixed inner mold bottom plate is provided with a second connecting hole opposite to the second threaded hole. The piston rod of the second cylinder is fixedly connected to the fixed inner mold base plate by a connecting bolt that passes through the second connecting hole and is screwed into the second threaded hole.

7. A precast hollow box girder formwork system for bridges as described in claim 6, characterized in that: several high-strength threaded rods are arranged on both sides of the fixed inner formwork base plate along the left and right directions; One end of the threaded rod is screwed into the third threaded hole pre-set on the side of the fixed inner mold base plate. The length of the threaded rod can be adjusted by rotating the threaded rod. The threaded rods on the left and right sides are staggered. The threaded rod is equipped with inner mold base plate assembly segments of various sizes for use with it. The inner mold base plate assembly segment is provided with several third connecting holes that run through the left and right directions. The outer end of the third connecting hole is enlarged to form a countersunk hole. The threaded rod passes through the third connecting hole and locks one or more inner mold base plate assembly segments to both sides of the fixed inner mold base plate.

8. The precast hollow box girder formwork system for bridges as described in claim 7, characterized in that: The fixed inner mold top plate has several sliding rods arranged on both sides in the left-right direction. One end of the sliding rod is slidably connected to the sliding hole at the side end of the fixed inner mold top plate, and the other end is fixedly connected to the outer inner mold top plate. One or more quick-release sliding rod segments are provided on the sliding rod between the outer inner mold top plate and the fixed inner mold top plate. A limiting block is provided on the quick-release sliding rod segment closest to the fixed inner mold top plate. The quick-release slide bar segment is equipped with a quick-release inner mold top plate assembly segment, and the top of the quick-release inner mold top plate assembly segment is equipped with a third slot that cooperates with the quick-release slide bar segment. The fixed inner mold top plate and the outer inner mold top plate are both provided with a fourth threaded hole. The internal thread of the fourth threaded hole is made of high-strength steel. The quick-release inner mold top plate assembly segment is provided with a fourth connecting hole that runs vertically through the top and bottom. The pull-out mold release screw includes a high-strength screw body. The top of the screw body is provided with a striking block. A first limiting plate is screwed to the upper part of the screw body. Part of the screw body is used in conjunction with the fourth threaded hole. The lower end of the remaining screw body passes through the fourth connecting hole and is screwed with a second limiting plate. The upper end of the second limiting plate abuts against the quick-release inner mold top plate assembly segment. A third limiting plate is screwed to the screw body at the upper end of the quick-release inner mold top plate assembly segment. The bottom end of the third limiting plate is fixedly connected to the top of the quick-release inner mold top plate assembly segment. The lower end of the first limiting plate abuts against the detachable top beam. The inner mold side plate splicing sub-unit includes an inner mold lower side plate and an inner mold upper side plate. Several jacks are evenly arranged on the inner mold lower side plate along the front-back direction. The piston rod end of the jack is connected to a pull rod. The jacks are embedded in the preset installation groove of the inner mold lower side plate. The piston rod and pull rod of the jack pass through the groove wall facing the inner mold upper side plate and are fixedly connected to the inner mold upper side plate through the end of the pull rod. Several quick-release side templates are arranged on the pull rod between the inner mold lower side plate and the inner mold upper side plate. The quick-release side templates are fixedly connected to each other and to adjacent upper or lower inner mold side plates by positioning bolts. The quick-release side templates are available in several sizes and models. The outer surface of the quick-release side templates is provided with a fourth slot that matches the size and shape of the tie rod. The inner surfaces of the upper and lower inner mold side plates are respectively welded with connecting plates for engaging with the bottom end of the outer top plate of the inner mold or the top end of the inner mold bottom plate assembly segment. The connecting plates are fixedly connected to the corresponding outer top plate or inner mold bottom plate assembly segment by bolts.

9. A precast hollow box girder formwork system for bridges as described in claim 8, characterized in that: The demolding auxiliary tools include: U-shaped frame, rollers, traveling wheels, electric cylinder, and presser foot. The U-shaped frame includes a large U-shaped frame and a small U-shaped frame set inside and outside. The opening ends of the large U-shaped frame and the small U-shaped frame face the same direction and are connected and fixed by several crossbars. Rollers are rotatably connected to the crossbar. Two wheels are installed on each side of the U-shaped frame. Multiple electric cylinders are connected laterally on both sides of the U-shaped frame. The fixed end of the electric cylinder is fixedly connected to the U-shaped frame, and the telescopic end is connected to a pressure foot. The electric cylinder is electrically connected to the power supply through a control panel and cables.

10. The method of using the precast hollow box girder formwork system for bridges as described in claim 9, characterized in that, This includes methods for installing and removing the template; The template installation method includes the following steps: S11: According to the design dimensions of the outer mold side plate, fix the first oil cylinders on both sides in the set position and extend the first oil cylinders to the set height. At this time, the outer mold side plate support beam is located at the designed inclination angle and the outer mold side plate support beams on both sides are located at the set distance. Fix the slider to the linear slide rail. S12: Assemble the outer mold base plate assembly segments on the outer mold base plate support beams on both sides of the fixed outer mold base plate; make the inclined surface of the outermost outer mold base plate assembly segment abut against the outer mold side plate support beam; seal the adjacent outer mold base plate assembly segments and the outer mold base plate assembly segments with the fixed outer mold base plate through rubber gaskets. S13: Assemble the outer mold side plate assembly segments on the outer mold side plate support beam, wherein the horizontal plane of the bottom outer mold side plate assembly segment abuts against the top of the outermost outer mold bottom plate assembly segment. After reaching the design height, lock each outer mold side plate assembly segment with limit nuts; wherein, rubber gaskets are used to seal between adjacent outer mold side plate assembly segments and between outer mold side plate assembly segments and outer mold bottom plate assembly segments. S14: Connect and fix the fixed inner mold base plate to the second oil cylinder with connecting bolts, and raise the second oil cylinder to the set height; install the required number of inner mold base plate assembly segments on both sides of the fixed inner mold base plate so that the inner mold base plate reaches the design length; S15: Connect the fixed inner mold top plate by pulling the demolding screw, so that the outer top plate of the inner mold moves outward to a set distance, and connect and fix the outer top plate of the inner mold by pulling the demolding screw. Install the quick-release inner mold top plate assembly segment and connect the corresponding pulling demolding screw. Adjust the position of the first limit plate so that the inner mold top plate assembly sub-unit is at the required height. S16: Fix the lower side plate and upper side plate of the inner mold to the corresponding outer top plate or bottom plate of the inner mold using bolts, and install the required number of quick-release side templates. S17: Seal both ends of the template system using end templates; The demolding method includes: S21: After the box girder is formed and reaches the design strength, first remove the end formwork, then remove the quick-release inner formwork top plate assembly segment and quick-release side formwork. S22: Move the first limiting plate upward and use a rubber hammer to strike the block to loosen the contact surface between the fixed inner mold top plate, the outer inner mold top plate and the concrete. S23: Remove all tie rods and demolding bolts, start each jack to pull down the upper side plate of the inner mold, and complete the demolding of the upper side plate of the inner mold. During the downward movement of the upper side plate of the inner mold, the outer top plate of the inner mold moves towards the side of the fixed inner mold top plate; when the limit block abuts against the side end of the fixed inner mold top plate, the upper side plate of the inner mold abuts against the concrete surface, and the jacks stop. S24: Start the second hydraulic cylinder to lift the inner mold bottom plate splicing sub-unit upward, so that the inner mold bottom plate splicing sub-unit is loosened from the concrete contact surface; S25: Remove the connecting bolts to retract the second hydraulic cylinder, start the jack to lift the splicing sub-unit of the inner mold lower side plate and the inner mold bottom plate, and complete the demolding of the inner mold lower side plate; S26: Start the extension of the second hydraulic cylinder to lift the inner mold template splicing unit to a set height, then insert the demolding auxiliary tool to extend the electric cylinders on both sides of the demolding auxiliary tool, and press the pressure foot connected to the end of the electric cylinder to the inner wall of the box girder. The second hydraulic cylinder retracts and places the inner mold template splicing unit on the top of the roller of the demolding auxiliary tool. The inner mold template splicing unit is then pulled out as a whole by the dragging device. S27: The first hydraulic cylinder shortens, pulling the outer mold side plate support beam outward, and dismantling each outer mold side plate assembly segment in sequence; the vibrator inside the mold table is started to loosen the contact surface between the outer mold bottom plate splicing unit and the concrete. S28: Remove the detachable top beam, use a crane to lift the box girder segments to other construction locations, and remove the outer formwork bottom plate to assemble the segments.

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