Prestressed self-locking type prefabricated concrete small box girder inner mold

Abstract

The application discloses a prestressed self-locking type prefabricated concrete small box girder inner mold, which comprises at least two beam body segments arranged in sequence, and the central axes of the two beam body segments are coincident; four mounting channels are arranged in each beam body segment, and the four mounting channels are arranged in the four corners of the longitudinal section of the beam body segment; the side of the adjacent two beam body segments close to each other is connected through a plurality of conical pin shafts and conical pin sleeves; for each mounting channel, a prestressed tendon is arranged in the mounting channel, one end of the prestressed tendon is fixedly connected with one end of the spliced beam body segment through a fixing piece; the other end of the prestressed tendon is coaxially fixedly connected with a threaded steel connecting rod through a connecting rod connector, the threaded steel connecting rod penetrates out of the other end of the spliced beam body segment, and a nut is threadedly connected on the threaded steel connecting rod. The concrete small box girder inner mold can be quickly assembled and disassembled, construction personnel do not need to enter the inside of the small box girder for construction, and the safety and construction efficiency of the small box girder construction are improved.

Description

Technical Field

[0001] This invention relates to the field of bridge construction formwork technology, and in particular to a prestressed self-locking type precast concrete small box girder inner formwork. Background Technology

[0002] With the rapid development of municipal highway bridge construction in China, precast small box girders are widely used due to their high load-bearing capacity, high rigidity, and economic practicality. Precast small box girders are hollow inside and require internal formwork for shaping. The limitations of height and space within the small box girder present certain challenges to the design, fabrication, and installation / disassembly of the internal formwork. Traditionally, internal formwork is typically designed and fabricated using several small panels based on the structure of each section, which are then assembled into a single formwork.

[0003] Currently, most concrete box girder internal formwork is a spliced ​​formwork, composed of several small steel formwork panels. It is generally hoisted, assembled, and fixed using manual labor and machinery. The formwork panels are connected by bolts and have numerous internal supports. During dismantling, construction workers need to enter the box girder to remove all bolts and support members, disassemble the internal formwork, and then remove it piece by piece. When needed, they must reassemble each piece, which not only increases labor intensity and production costs but also causes significant inconvenience to construction workers and easily leads to formwork deformation, affecting the appearance and quality of the concrete. Summary of the Invention

[0004] This invention provides a prestressed self-locking precast concrete box girder inner mold that enables rapid assembly and disassembly without requiring construction personnel to enter the box girder, thereby improving the safety and efficiency of box girder construction.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a prestressed self-locking type precast concrete small box girder inner mold, comprising at least two beam segments arranged sequentially, the central axes of the two beam segments coinciding; each beam segment is provided with four installation channels, and the four installation channels are respectively located in the four corners of the longitudinal section of the beam segment; the installation channels at corresponding positions of adjacent beam segments are interconnected.

[0007] It also includes multiple tapered pins and tapered pin sleeves, with each tapered pin and tapered pin sleeve corresponding to the other; two adjacent beam segments are connected on their sides by multiple tapered pins and tapered pin sleeves.

[0008] It also includes prestressed installation components, the number of which matches the number of installation channels; each prestressed installation component includes a prestressing tendon, a threaded steel connecting rod, a connecting rod connector, a fastener, a pad, and a nut;

[0009] For each of the installation channels, the prestressing tendon passes through the installation channel, and one end of the tendon is fixedly connected to one end of the spliced ​​beam segment via the fastener; the other end of the prestressing tendon is coaxially fixedly connected to the threaded steel connecting rod via the connecting rod connector, the threaded steel connecting rod passes through the other end of the spliced ​​beam segment, the nut is threadedly connected to the threaded steel connecting rod, and the washer is located between the other end of the spliced ​​beam segment and the nut.

[0010] In one possible implementation, the interconnected installation channels are one of a straight channel, a polygonal channel, or a curved channel.

[0011] In one possible implementation, each beam segment includes a left half-form and a right half-form;

[0012] The top wall of the left half mold and the top wall of the right half mold are spliced ​​together to form the top wall of the beam segment; the bottom wall of the left half mold and the bottom wall of the right half mold are spliced ​​together to form the bottom wall of the beam segment; the side wall of the left half mold and the side wall of the right half mold are respectively the two side walls of the beam segment.

[0013] In one possible implementation, the joints of the top wall and the bottom wall of the beam segment are both staggered at acute angles to the central axis of the beam segment.

[0014] In one possible implementation, the joints of the top walls of two adjacent beam segments are staggered.

[0015] The joints of the bottom walls of two adjacent beam segments are staggered.

[0016] In one possible implementation, the joint between the left half and the right half is a slope.

[0017] In one possible implementation, the left half-module includes an upper connecting block, a lower connecting block, a hinge shaft, and a tensioning and opening force transmission mechanism;

[0018] The upper connecting block includes the upper region of the side wall of the left half mold and the top wall of the left half mold, and the lower connecting block includes the lower region of the side wall of the left half mold and the bottom wall of the left half mold. The upper connecting block and the lower connecting block are connected by the hinge shaft.

[0019] The tensioning and releasing force transmission mechanism is connected to the upper connecting block and the lower connecting block, and is used to control the raising or lowering of the upper connecting block and the lower connecting block.

[0020] In one possible implementation, the right half of the module has the same structure as the left half of the module.

[0021] In one possible implementation, the tension-opening force transmission mechanism includes a longitudinal tie rod, a power crank, a power shaft, a shaft seat, a connecting rod shaft, a connecting rod, and a safety pin;

[0022] The longitudinal tie rod is disposed between the upper connecting block and the lower connecting block, and is disposed along the long side of the upper connecting block;

[0023] The connecting rod shafts are multiple and are spaced apart on the side of the upper connecting block and the lower connecting block that are close to each other;

[0024] The connecting rods correspond one-to-one with the connecting rod shafts, and one end of the connecting rod is rotatably connected to the connecting rod shaft, while the other end of the connecting rod is rotatably connected to the longitudinal tie rod.

[0025] A connecting plate is provided on the side of the lower connecting block near the upper connecting block, and an arc-shaped sliding groove is provided on the connecting plate, with the central angle of the arc-shaped sliding groove facing the lower connecting block;

[0026] The rotating shaft seat is fixed to the side of the lower connecting block near the upper connecting block. One end of the power rotating shaft is rotatably connected to the rotating shaft seat, and the other end is rotatably connected to the power crank. The other end of the power crank is slidably connected to the arc-shaped groove.

[0027] The safety pin is located on any one of the connecting rods at the end of the left half mold.

[0028] In one possible implementation, the top wall of the beam segment has multiple hoisting holes.

[0029] This invention provides a prestressed self-locking precast concrete small box girder inner formwork assembled from at least two beam segments. When the user needs to assemble the beam segments, the prestressing tendons and threaded steel connecting rods are pulled at both ends of the placed beam segments to compress multiple beam segments, making them tightly connected under the action of tapered pins and tapered sleeves. Finally, the nuts are tightened to fix the tightly connected beam segments. When the user needs to disassemble the assembled beam segments, simply loosen the nuts, remove all components of the prestressed installation assembly, and then disconnect the tapered pins and tapered sleeves of adjacent beam segments from the outside to disassemble the beam segments one by one. The operation is simple and convenient, enabling rapid assembly and disassembly of the concrete small box girder inner formwork without requiring construction personnel to enter the small box girder for construction, thus improving the safety and efficiency of small box girder construction. Attached Figure Description

[0030] Figure 1This is a schematic diagram of the overall structure of a prestressed self-locking precast concrete small box girder inner mold provided in an embodiment of the present invention, wherein (a) is a front view of the entire small box girder inner mold, (b) is a top view of the entire small box girder inner mold, and (c) is a partial sectional view of the small box girder inner mold used to display the prestressed installation components.

[0031] Figure 2 (a) is Figure 1 Cross-sectional view along the AA direction. Figure 2 (b) is Figure 1 A schematic diagram of the connection structure at the CC position. Figure 2 (c) is Figure 1 Schematic diagram of the connection structure at position BB in the middle;

[0032] Figure 3 This is a structural schematic diagram of one beam segment of a prestressed self-locking precast concrete small box girder inner formwork provided in an embodiment of the present invention, wherein (a) is a bottom view of the beam segment, (b) is a front view of the beam segment, (c) is a top view of the beam segment, (d) is a side view of the beam segment in direction A, and (e) is a side view of the beam segment in direction B.

[0033] Figure 4 This is a schematic diagram of the internal structure of one beam segment of a prestressed self-locking precast concrete small box girder inner mold provided in an embodiment of the present invention. (a) is a schematic diagram of the internal structure of the beam segment when the tensioning and opening force transmission mechanism is supported, and (b) is a schematic diagram of the internal structure of the beam segment when the tensioning and opening force transmission mechanism is released.

[0034] Figure 5 A perspective view of the left half of the inner mold of one beam segment of a prestressed self-locking precast concrete small box girder, provided for an embodiment of the present invention;

[0035] Figure 6 A perspective view of the left and right halves of one beam segment of a prestressed self-locking precast concrete small box girder inner mold provided in an embodiment of the present invention, after being spliced ​​together;

[0036] Figure 7 This is a perspective view of the upper connecting block of the left half of the inner mold of a prestressed self-locking precast concrete small box girder, provided as an embodiment of the present invention.

[0037] Figure labels and descriptions:

[0038] 1. Support section; 2. Transition section; 3. Beam body section; 4. Prestressed installation assembly; 4-1. Prestressed tendon; 4-2. Fixture; 4-3. Threaded steel connecting rod; 4-4. Nut; 4-5. Connecting rod connector; 4-6. Pad; 5. Upper connecting block of the left half mold; 6. Lower connecting block of the left half mold; 7. Upper connecting block of the right half mold; 8. Lower connecting block of the right half mold; 9. Hinge shaft; 10. Tensioning and closing force transmission mechanism; 10-1. Longitudinal tie rod; 10-2. Power crank; 10-3. Power shaft; 10-4. Shaft seat; 10-5. Connecting rod shaft; 10-6. Connecting rod; 10-7. Safety pin; 11. Ring locking pin; 12. Tapered pin; 13. Tapered pin sleeve; 14. Plastic steel strip; 15. Lifting hole; 16. Lifting hook. Detailed Implementation

[0039] 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.

[0040] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more. Furthermore, the use of "based on" or "according to" implies openness and inclusiveness, because processes, steps, calculations, or other actions "based on" or "according to" one or more of the stated conditions or values ​​may in practice be based on additional conditions or beyond the stated values.

[0041] In existing technologies, the inner formwork of concrete box girders is mostly a spliced ​​formwork, composed of several small steel formwork panels. It is generally hoisted, assembled, and fixed using manual labor and machinery. The formwork panels are connected by bolts, and numerous internal supports are installed. During the assembly and disassembly of the inner formwork, construction personnel must enter the confined cavity of the inner formwork to tighten or loosen the connecting bolts of the longitudinal and circumferential joints. The problems with this operation are as follows:

[0042] First, the narrow space inside the steel structure model cavity makes operation difficult, and construction personnel have difficulty controlling the connection quality of the template.

[0043] Secondly, the demolding of the steel structure internal formwork is carried out when the concrete of the small box girder reaches a certain strength. In summer, the temperature inside the internal formwork cavity can reach 50-60℃, posing a high safety risk to construction workers.

[0044] Third, the slow speed of disassembling or installing bolts results in long construction time and low efficiency.

[0045] like Figures 1-2 As shown, this embodiment of the invention provides a prestressed self-locking precast concrete small box girder inner mold, comprising at least two beam segments arranged sequentially, with the central axes of the two beam segments coinciding.

[0046] The beam segment comprises a support segment 1, a transition segment 2, and a beam body segment 3. The beam body segment 3 is coaxially positioned between two support segments 1, and the transition segment 2 is positioned between the support segment 1 and the beam body segment 3. The support segment 1 and the beam body segment 3 have uniform thickness along their length, while the thickness of the transition segment 2 can be uniform or gradually varied along its length, serving to create a transition between the support segment 1 and the beam body segment 3. The thickness of the transition segment 2 near the support segment 1 is the same as the thickness of the support segment 1, and the thickness near the beam body segment 3 is the same as the thickness of the beam body segment 3.

[0047] In this embodiment, when prefabricating a 30-meter-long, 1-meter-wide precast concrete box girder, the required thickness of the support section 1 of the inner formwork of the precast concrete box girder is uniform, and the length is 2315mm; the thickness of the beam section 3 is uniform, and the length is 24770mm; the thickness of the transition section 2 gradually increases, and the length is 300mm.

[0048] Therefore, in the actual assembly of the precast concrete box girder inner formwork, the length of support section 1 is determined to be 2500mm, two support sections 1 are used, and the ends of support sections 1 are exposed 285mm from the beam end of the concrete box girder; the length of transition section 2 is determined to be 2635mm, two transition sections 2 are used; and the length of beam body section 3 is determined to be 2900mm, seven beam body sections 3 are used.

[0049] Figure 1 In (a), X represents the state where two adjacent beam segments are not spliced, that is, the circumferential joint between two adjacent beam segments is not closed; Figure 1 In (a), Y represents the state after two adjacent beam segments are spliced ​​together, that is, the state after the circumferential joint between two adjacent beam segments is closed.

[0050] Each beam segment has four installation channels, which are located at the four corners of the longitudinal section of the beam segment. The installation channels at corresponding positions of adjacent beam segments are interconnected.

[0051] The installation channel is a straight through hole set in the four side walls of the beam segment.

[0052] It also includes multiple tapered pins 12 and tapered pin sleeves 13, with each tapered pin 12 and tapered pin sleeve 13 corresponding to the other; two adjacent beam segments are connected on the side that is close to each other by multiple tapered pins 12 and tapered pin sleeves 13.

[0053] Among them, the number and position of the tapered pins 12 and tapered pin sleeves 13 on the side of two adjacent beam segments that are close to each other are matched.

[0054] In this embodiment, as Figure 2 As shown in (b) and (c), multiple tapered pins 12 are installed at intervals on the end of the beam segment on the right, and tapered pin sleeves 13 are installed on the end of the beam segment on the left, corresponding to those on the right. When the central axes of the two beam segments coincide, they are pressed towards each other, causing the tapered pins 12 and tapered pin sleeves 13 to be locked together. In the figure, N represents the area where the end plates of the two beam segments overlap.

[0055] Taking the beam segment on the right as an example, in this embodiment, five tapered pins 12 are equally spaced at the end of the top wall of the beam segment, three tapered pins 12 are equally spaced at the end of the bottom wall, and two tapered pins 12 are spaced at the end of each of the two side walls.

[0056] To make the connection between support section 1 and transition section 2, and between transition section 2 and beam section 3 more robust, the number of tapered pins 12 or tapered pin sleeves 13 needs to be increased at the end of transition section 2 and at the end of support section 1 or beam section 3 to which it is assembled. Flat round positioning bushing assemblies are also needed for further reinforcement. An annular locking pin buckle 11 is installed at a position about 430mm from the end face of transition section 2 near the end face of beam section 3 for further reinforcement.

[0057] It also includes a prestressed installation assembly 4, the number of which matches the number of installation channels; each prestressed installation assembly 4 includes a prestressed tendon 4-1, a threaded steel connecting rod 4-3, a connecting rod 10-6 connector 4-5, a fastener 4-2, a pad 4-6, and a nut 4-4;

[0058] For each installation channel, the prestressing tendon 4-1 is inserted into the installation channel, and one end of it is fixedly connected to one end of the spliced ​​beam segment through the fastener 4-2; the other end of the prestressing tendon 4-1 is coaxially fixedly connected to the threaded steel connecting rod 4-3 through the connector 4-5 of the connecting rod 10-6, the threaded steel connecting rod 4-3 extends out of the other end of the spliced ​​beam segment, the nut 4-4 is threadedly connected to the threaded steel connecting rod 4-3, and the pad 4-6 is located between the other end of the spliced ​​beam segment and the nut 4-4.

[0059] In this embodiment, the prestressing tendon 4-1 is a 15.2mm diameter prestressing tendon 4-1. The anchoring points of the fixing member 4-2 and the nut 4-4 are located approximately 455mm inside the end face of the support section 1. The fixing member 4-2 includes a fixing anchor and a clamp, and the prestressing tendon 4-1 is detachably connected to the support section 1 through the fixing anchor and the clamp. One end of the fixing member 4-2 is the passive tensioning end during the prestressing tensioning process, and one end of the threaded steel connecting rod 4-3 is the active tensioning end during the prestressing tensioning process.

[0060] This invention provides a prestressed self-locking precast concrete small box girder inner mold formed by splicing at least two beam segments. When the user needs to splice the beam segments, the prestressing tendons 4-1 and threaded steel connecting rods 4-3 are pulled at both ends of the placed beam segments to compress multiple beam segments, making them tightly connected under the action of tapered pins 12 and tapered pin sleeves 13. Finally, the nuts 4-4 are tightened to fix the tightly connected beam segments. When the user needs to disassemble the spliced ​​beam segments, they only need to loosen the nuts 4-4, remove all parts of the prestressed installation assembly 4, and then disconnect the tapered pins 12 and tapered pin sleeves 13 of two adjacent beam segments from the outside to disassemble the beam segments one by one.

[0061] This invention is simple and convenient to operate, enabling rapid assembly and disassembly of the inner formwork of concrete small box girders without requiring construction personnel to enter the interior of the small box girder, thus improving the safety and efficiency of small box girder construction.

[0062] Furthermore, the interconnected installation channels can be one of the following: a straight channel, a broken line channel, or a curved channel.

[0063] Specifically, after all the beam segments are neatly arranged, the shape of the interconnected installation channels is not specifically restricted, as long as the prestressing tendons 4-1 can pass through from one end of the inner membrane to the other end.

[0064] like Figure 3 , Figure 4 As shown, each beam segment further includes a left half-form and a right half-form;

[0065] The top walls of the left and right half-forms are joined together to form the top wall of the beam segment; the bottom walls of the left and right half-forms are joined together to form the bottom wall of the beam segment; the side walls of the left and right half-forms are respectively the two side walls of the beam segment.

[0066] To facilitate the production, storage, and transportation of beam segments, the beam segments are made into separate templates, which are then assembled before use.

[0067] Before splicing multiple beam segments, the left and right halves of the formwork need to be spliced ​​into a single beam segment using plastic steel strip 14.

[0068] Furthermore, the joints on the top and bottom walls of the beam segments are staggered at acute angles to the central axis of the beam segments. The joints on the top and bottom walls of the beam segments are denoted by M in the figure.

[0069] In other words, the angle between the joint of the top wall of the beam segment and the joint of the bottom wall of the beam segment and the central axis of the beam segment is an acute angle. That is, the top wall of the beam segment is wedge-shaped through the joint of the top wall of the beam segment, and the bottom wall of the beam segment is wedge-shaped through the joint of the bottom wall of the beam segment.

[0070] In this embodiment, the average deviation angle between the joints at the top and bottom of the beam segment and the straight line mapped to the central axis on the top or bottom wall is 80 mm.

[0071] like Figure 1 As shown in (b), furthermore, the joints of the top walls of two adjacent beam segments are staggered.

[0072] The joints of the bottom walls of two adjacent beam segments are staggered.

[0073] In practical applications, staggering the positions of the top wall joints and bottom wall joints of multiple beam segments can further increase the strength of the inner membrane.

[0074] like Figure 2 or Figure 3 As shown, further, the joint between the left and right halves of the mold is a slope.

[0075] Compared to a vertical cut, setting the splicing as a bevel makes the connection between the left and right halves of the mold more secure.

[0076] like Figure 4 , Figure 5 and Figure 6 As shown, both the left and right half molds further include an upper connecting block, a lower connecting block, a hinge shaft 9, and a tensioning and force transmission mechanism 10.

[0077] Specifically, the left half mold includes the upper connecting block 5 of the left half mold, the lower connecting block 6 of the left half mold, the hinge shaft 9, and the tension and opening force transmission mechanism 10.

[0078] The upper connecting block 5 of the left half mold includes the upper region of the side wall of the left half mold and the top wall of the left half mold. The upper connecting block 5 of the left half mold includes the lower region of the side wall of the left half mold and the bottom wall of the left half mold. The upper connecting block 5 of the left half mold and the lower connecting block 6 of the left half mold are connected by a hinge pin 9.

[0079] The tension transmission mechanism 10 is connected to the upper connecting block 5 and the lower connecting block 6 of the left half mold, and is used to control the lifting or loosening of the upper connecting block 5 and the lower connecting block 6 of the left half mold.

[0080] Furthermore, the right half of the mold has the same structure as the left half.

[0081] Specifically, the right half mold includes the upper connecting block 7, the lower connecting block 8, the hinge shaft 9, and the tension and opening force transmission mechanism 10.

[0082] The upper connecting block 7 of the right half mold includes the upper region of the side wall of the right half mold and the top wall of the right half mold. The upper connecting block 7 of the right half mold includes the lower region of the side wall of the right half mold and the bottom wall of the right half mold. The upper connecting block 7 of the right half mold and the lower connecting block 8 of the right half mold are connected by a hinge 9.

[0083] The tension transmission mechanism 10 is connected to the upper connecting block 7 and the lower connecting block 8 of the right half mold, and is used to control the lifting or loosening of the upper connecting block 7 and the lower connecting block 8 of the right half mold.

[0084] Furthermore, the tension and connection force transmission mechanism 10 includes a longitudinal tie rod 10-1, a power crank 10-2, a power shaft 10-3, a shaft seat 10-4, a connecting rod 10-6, a shaft 10-5, a connecting rod 10-6, and a safety pin 10-7.

[0085] The longitudinal tie rod 10-1 is set between the upper connecting block and the lower connecting block, and is set along the long side of the upper connecting block.

[0086] There are multiple connecting rods 10-6 and rotating shafts 10-5, which are spaced apart and located on the side of the upper connecting block and the lower connecting block that are close to each other.

[0087] Connecting rod 10-6 corresponds one-to-one with connecting rod 10-6 pivot 10-5, and one end of connecting rod 10-6 is rotatably connected to connecting rod 10-6 pivot 10-5, while the other end of connecting rod 10-6 is rotatably connected to longitudinal tie rod 10-1.

[0088] In this embodiment, there are 6 connecting rods 10-6, of which 3 are used to connect the longitudinal tie rod 10-1 to the top wall of the right half mold or the left half mold, and the other 3 are used to connect the longitudinal tie rod 10-1 to the bottom wall of the right half mold or the left half mold.

[0089] A connecting plate is provided on the side of the lower connecting block near the upper connecting block, and an arc-shaped groove is provided on the connecting plate, with the central angle of the arc-shaped groove facing the lower connecting block.

[0090] The rotating shaft seat 10-4 is fixed on the side of the lower connecting block near the upper connecting block. One end of the power rotating shaft 10-3 is rotatably connected to the rotating shaft seat 10-4, and the other end is rotatably connected to the power crank 10-2. The other end of the power crank 10-2 is slidably connected to the arc-shaped slide groove.

[0091] The safety pin 10-7 is set on any one of the connecting rods 10-6 at the end of the left half mold.

[0092] Specifically, to facilitate the user's insertion and removal of the safety pin 10-7, the safety pin 10-7 is set on a connecting rod 10-6 near the end of the beam segment.

[0093] like Figure 3 and Figure 7 As shown, furthermore, the top wall of the beam segment has multiple hoisting holes 15.

[0094] In this embodiment, the top of the beam segment is rectangularly provided with four lifting holes 15. The lifting holes are long and box-shaped structures. The lifting holes 15 are connected to the top wall of the beam segment. The hook 16 is an anchor hook structure. After the anchor hook passes through the lifting hole 15, it can be rotated 90 degrees to hook onto the top wall of the beam segment.

[0095] In this invention, multiple beam segments of the prestressed self-locking precast concrete small box girder inner mold are connected in series by prestressed installation components 4. Adjacent beam segments are connected by annular locking pins 11, tapered pins 12, and tapered pin sleeves 13. The joints of each beam segment are wedge-shaped, achieving boltless connection of the entire inner mold. The connection quality is reliable and precise. By pulling the prestressed tendons 4-1 and threaded steel connecting rods 4-3 at both ends of the placed beam segments, the splicing between multiple beam segments can be achieved.

[0096] In this invention, the left and right halves of the prestressed self-locking precast concrete box girder inner mold are connected by a tensioning force transmission mechanism 10. Only one force F needs to be applied to the power crank 10-2, and the power crank 10-2 can drive multiple connecting rods 10-6 to support it through the longitudinal tie rod 10-1, thereby realizing the assembly and fixing of the left or right half mold. Not only is the structure simple and easy to operate, but the longitudinal tie rod 10-1 mechanism can also reasonably distribute F according to the displacement of the inner mold.

[0097] The prestressed self-locking precast concrete small box girder inner formwork of the present invention eliminates the need for construction personnel to enter the narrow cavity of the inner formwork during formwork assembly and disassembly, thereby improving the connection quality of the inner formwork, improving the working environment, reducing operational safety risks, and increasing construction efficiency.

[0098] The prestressed self-locking precast concrete small box girder inner mold of the present invention can meet the needs of industrial production of precast concrete small box girders and has good economic, technological and social benefits.

[0099] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A prestressed self-locking type precast concrete small box girder inner mold, characterized in that, It includes at least two beam segments arranged sequentially, with the central axes of the two beam segments coinciding; each beam segment is provided with 4 installation channels, and the four installation channels are respectively located in the four corners of the longitudinal section of the beam segment; the installation channels at corresponding positions of adjacent beam segments are interconnected. It also includes multiple tapered pins and tapered pin sleeves, with each tapered pin and tapered pin sleeve corresponding to the other; two adjacent beam segments are connected on their sides by multiple tapered pins and tapered pin sleeves. It also includes prestressed installation components, the number of which matches the number of installation channels; each prestressed installation component includes a prestressing tendon, a threaded steel connecting rod, a connecting rod connector, a fastener, a pad, and a nut; For each of the installation channels, the prestressing tendon passes through the installation channel, and one end of the tendon is fixedly connected to one end of the spliced ​​beam segment via the fastener; the other end of the prestressing tendon is coaxially fixedly connected to the threaded steel connecting rod via the connecting rod connector, the threaded steel connecting rod passes through the other end of the spliced ​​beam segment, the nut is threadedly connected to the threaded steel connecting rod, and the washer is located between the other end of the spliced ​​beam segment and the nut.

2. The inner formwork for a small concrete box girder according to claim 1, characterized in that, The installation channels, when interconnected, can be one of a straight channel, a broken line channel, or a curved channel.

3. The inner formwork for a concrete small box girder according to claim 1, characterized in that, Each beam segment includes a left half-form and a right half-form; The top wall of the left half mold and the top wall of the right half mold are spliced ​​together to form the top wall of the beam segment; the bottom wall of the left half mold and the bottom wall of the right half mold are spliced ​​together to form the bottom wall of the beam segment; the side wall of the left half mold and the side wall of the right half mold are respectively the two side walls of the beam segment.

4. The inner formwork for a small concrete box girder according to claim 3, characterized in that, The joints of the top wall and the bottom wall of the beam segment are both staggered at acute angles with the central axis of the beam segment.

5. The inner mold for a small concrete box girder according to claim 3 or 4, characterized in that, The joints of the top walls of two adjacent beam segments are staggered. The joints of the bottom walls of two adjacent beam segments are staggered.

6. The inner formwork for a small concrete box girder according to claim 3, characterized in that, The joint between the left half and the right half is a slope.

7. The inner formwork for a concrete small box girder according to claim 3, characterized in that, The left half mold includes an upper connecting block, a lower connecting block, a hinge shaft, and a tensioning and opening force transmission mechanism; The upper connecting block includes the upper region of the side wall of the left half mold and the top wall of the left half mold, and the lower connecting block includes the lower region of the side wall of the left half mold and the bottom wall of the left half mold. The upper connecting block and the lower connecting block are connected by the hinge shaft. The tensioning and releasing force transmission mechanism is connected to the upper connecting block and the lower connecting block, and is used to control the raising or lowering of the upper connecting block and the lower connecting block.

8. The inner formwork for a concrete small box girder according to claim 7, characterized in that, The right half of the mold has the same structure as the left half of the mold.

9. The inner formwork for a small concrete box girder according to claim 7, characterized in that, The tension and opening force transmission mechanism includes a longitudinal tie rod, a power crank, a power shaft, a shaft seat, a connecting rod shaft, a connecting rod, and a safety pin; The longitudinal tie rod is disposed between the upper connecting block and the lower connecting block, and is disposed along the long side of the upper connecting block; The connecting rod shafts are multiple and are spaced apart on the side of the upper connecting block and the lower connecting block that are close to each other; The connecting rods correspond one-to-one with the connecting rod shafts, and one end of the connecting rod is rotatably connected to the connecting rod shaft, while the other end of the connecting rod is rotatably connected to the longitudinal tie rod. A connecting plate is provided on the side of the lower connecting block near the upper connecting block, and an arc-shaped sliding groove is provided on the connecting plate, with the central angle of the arc-shaped sliding groove facing the lower connecting block; The rotating shaft seat is fixed to the side of the lower connecting block near the upper connecting block. One end of the power rotating shaft is rotatably connected to the rotating shaft seat, and the other end is rotatably connected to the power crank. The other end of the power crank is slidably connected to the arc-shaped groove. The safety pin is located on any one of the connecting rods at the end of the left half mold.

10. The inner formwork for a small concrete box girder according to claim 1, characterized in that, The top wall of the beam segment has multiple hoisting holes.

Images