A precast beam core mold anti-floating and anti-pull-down fixing device

Abstract

This utility model discloses a precast beam core mold anti-floating and anti-pull-down fixing device, including a bottom template supported on the upper part of the precast beam platform, side templates supported by support frames on both sides of the bottom template, and a core mold supported in the internal space formed by the side templates and the bottom template. Several tie rod devices are evenly arranged between the bottom of the core mold and the bottom template to prevent the core mold from floating during pouring. The tie rod devices include threaded tie rods that penetrate the bottom template and the upper end of the core mold. The precast beam core mold anti-floating and anti-pull-down fixing device provided in this application effectively solves the problems of low construction efficiency and serious damage to the core mold caused by the traditional pressure bar fixing method by setting tie rod devices between the bottom of the core mold and the bottom template and adopting a structural design of threaded tie rods and sealing and pressing components. It has the advantages of improving construction efficiency, protecting the integrity of the core mold, improving construction operability and ensuring the dimensional accuracy of the precast beam structure.

Description

Technical Field

[0001] This utility model relates to the field of precast beam core molds, specifically to a precast beam core mold anti-floating and anti-pull-down fixing device. Background Technology

[0002] In precast beam construction, the core mold is typically installed and the top slab reinforcement is tied. Before pouring concrete, several rigid support bars are installed on the top of the box girder to fix the support bars to the outer formwork of the precast beam. Multiple support rods are welded to the support bars to hold the core mold in place and prevent it from floating (e.g., Figure 4 As shown in the figure, the installation and removal of the pressure bar during construction is cumbersome and time-consuming. The support point of the pressure bar causes serious damage to the core mold, and the damaged template needs to be replaced from time to time. After the pressure bar is installed, it forms an obstacle when pouring concrete from the top, which is very inconvenient for workers to carry out construction on the top of the precast beam. It also seriously affects the roughening of the surface finish on the top of the precast beam. Utility Model Content

[0003] To address the aforementioned problems, this utility model provides a precast beam core mold anti-floating and anti-pull-down fixing device.

[0004] This utility model is achieved through the following technical solution:

[0005] This application provides a precast beam core mold anti-floating and anti-drift fixing device, the technical solution of which is as follows: it includes a bottom template supported on the upper part of the precast beam platform, side templates supported by support frames connected to both sides of the bottom template, and a core mold is set in the internal space formed by the side templates and the bottom template. Several tie rod devices are evenly arranged between the bottom of the core mold and the bottom template to prevent the core mold from floating during pouring. The tie rod device includes a threaded tie rod that penetrates the bottom template and the upper end of the core mold. A sealed PVC sleeve is set on the outside of the threaded tie rod, and the PVC sleeve is fixed by a sealing and clamping assembly.

[0006] Furthermore, this application also proposes that the core mold base plate has a through circular hole, the bottom template has a stepped hole in the center, and the sealing and pressing assembly is set on the step inside the stepped hole.

[0007] Furthermore, this application also proposes that the sealing and clamping assembly includes a compression spring and a washer located within the stepped hole and fitted onto the threaded tie rod, with a PVC sleeve supported on the washer.

[0008] Furthermore, this application also proposes that the PVC sleeve extends upward to contact the pressure plate on the upper part of the core mold base plate, and longitudinal template ribs are provided on both sides of the lower part of the pressure plate to form a filling cavity, which is filled with foam glue to prevent leakage from the top of the PVC sleeve.

[0009] Furthermore, this application also proposes that the lower part of the threaded tie rod is threaded through a stepped hole and connected to a fixing nut at the lower end, and the fixing nut is welded and fixed to the bottom of the support channel steel provided at the lower part of the bottom template.

[0010] Furthermore, this application also proposes that the top of the threaded tie rod passes through a pressure plate disposed on the upper part of the core mold base plate, and the pressure plate is movably provided with a clamping nut that is screwed to the threaded tie rod.

[0011] Compared with existing technologies, the beneficial effects of this utility model are as follows: The precast beam core mold anti-floating and anti-pull-down fixing device provided in this application, by setting a tie rod device between the bottom of the core mold and the bottom template, and adopting a structural design of threaded tie rod and sealing and pressing components, effectively solves the problems of low construction efficiency and serious damage to the core mold caused by the traditional pressure bar fixing method. It has the advantages of improving construction efficiency, protecting the integrity of the core mold, improving construction operability and ensuring the dimensional accuracy of the precast beam structure. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] Figure 2 yes Figure 1 Enlarged view of the partial structure marked A;

[0014] Figure 3 yes Figure 1 Enlarged view of the local structure marked B;

[0015] Figure 4 This is a schematic diagram of the prior art of this utility model;

[0016] In the diagram: 1. Precast beam platform; 2. Side formwork; 3. Support frame; 4. Bottom formwork; 5. Core mold; 6. Pressure bar; 61. Support rod; 7. Tie rod device; 8. Round hole; 9. Stepped hole; 10. Threaded tie rod; 11. Longitudinal formwork rib; 12. Pressure plate; 13. Pressure nut; 14. Support channel steel; 15. Fixing nut; 16. Washer; 17. Compression spring; 18. PVC sleeve. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0018] like Figure 1-3 As shown, this application proposes a precast beam core mold anti-floating and anti-pull-down fixing device, including a bottom template supported on the upper part of the precast beam platform, side templates supported by support frames connected to both sides of the bottom template, and a core mold supported in the internal space formed by the side templates and the bottom template. The core mold is supported on the steps at both ends of the bottom template to form a supported state. Several tie rod devices are evenly arranged between the bottom of the core mold and the bottom template to prevent the core mold from floating during pouring. The tie rod device includes a threaded tie rod that penetrates the bottom template and the upper end of the core mold. A sealed PVC sleeve is provided on the outside of the threaded tie rod. The PVC sleeve is fixed by a sealing and clamping assembly.

[0019] The threaded tie rods can be made of precision-rolled threaded steel, and their diameter can be adjusted according to the size of the mandrel and the concrete pouring pressure, for example, M12-M20 threaded steel. The PVC sleeves are preferably made of corrosion-resistant rigid PVC material with a wall thickness of 2-3mm, and their length is longer than the mandrel thickness to ensure complete coverage of the threaded tie rods. The sealing and clamping assembly can be a combination of rubber gaskets and metal pressure plates, with the rubber gaskets recommended to have a Shore hardness of 60-80. The tie rod arrangement is typically spaced 2.5 meters apart, but can be evenly distributed according to the length of the mandrel. The bottom template and support frame can be connected by bolts, and the support frame is preferably made of angle steel or channel steel.

[0020] This technical solution effectively solves the problem of core mold floating by replacing the traditional top pressure bar with a tie rod device at the bottom. The threaded tie rod, combined with the sealing and clamping assembly, provides continuous downward tension during concrete pouring, preventing core mold displacement. The PVC sleeve ensures both airtightness and facilitates later disassembly. Compared with existing technologies, this device avoids the space occupation caused by the top pressure bar, simplifies the installation process, improves construction efficiency, and reduces damage to the formwork. Specifically, the tie rod device's method of fixing the core mold from the bottom makes the concrete pouring process smoother, provides more operating space for workers, and helps ensure the quality of the precast beam.

[0021] Furthermore, this application also proposes that the core mold base plate has a through circular hole, the bottom template has a stepped hole in the center, and the sealing and pressing assembly is set on the step inside the stepped hole.

[0022] The round hole is used to pass through the threaded tie rod, while the stepped hole design facilitates the installation of the sealing and clamping assembly and forms a stable support structure. The sealing and clamping assembly achieves axial positioning through the limiting effect of the stepped hole, while also providing installation space for the preload of the subsequent compression spring. Specifically, the stepped hole can adopt a multi-stage countersunk hole structure, and the stepped surface is machined to ensure flatness. The coaxiality error between the round hole and the stepped hole is controlled within 0.1mm to ensure the perpendicularity of the tie rod.

[0023] This technical solution, by incorporating a stepped hole structure, precisely positions the sealing and clamping component at a predetermined location, effectively solving the leakage problem caused by inaccurate installation of the sealing component in traditional pressure bar methods. Compared to the top pressure bar installation method in the prior art, this structure eliminates the need for an additional pressure bar during pouring, avoiding construction obstacles at the top. Simultaneously, the mechanical limiting effect of the bottom stepped holes ensures the stability of the sealing component under concrete pouring pressure, reducing the risk of seal failure due to vibration. Therefore, it simplifies the construction process and improves the reliability of the anti-floating structure.

[0024] Furthermore, this application also proposes that the sealing and clamping assembly includes a compression spring and a washer located within the stepped hole and fitted onto the threaded tie rod, with a PVC sleeve supported on the washer.

[0025] The compression spring can be made of stainless steel, and its elastic coefficient is determined based on the weight of the mandrel and the concrete pouring pressure. The outer diameter of the spring is slightly smaller than the inner diameter of the stepped hole to maintain vertical movement. The gasket is a ring-shaped metal sheet with an inner diameter that fits the threaded tie rod with a clearance, and an outer diameter larger than the outer diameter of the PVC sleeve to form a support surface. The PVC sleeve is made of rigid PVC material with a wall thickness of 2-3mm. Its length is determined based on the distance between the mandrel and the bottom template. The lower end of the sleeve is bonded to the gasket with hot melt adhesive.

[0026] This technical solution achieves dynamic sealing through spring preload. When the concrete pouring generates buoyancy, the spring compression keeps the gasket firmly against the bottom of the PVC sleeve, ensuring both sealing and allowing for slight displacement. Compared with existing technologies, the split sealing structure reduces the requirements for processing precision, and the spring compensation mechanism can adapt to pressure changes under different pouring conditions, while avoiding the formwork damage problems caused by traditional welded supports.

[0027] Furthermore, this application also proposes that the PVC sleeve extends upward to contact the pressure plate on the upper part of the core mold base plate, and longitudinal template ribs are provided on both sides of the lower part of the pressure plate to form a filling cavity, which is filled with foam glue to prevent leakage from the top of the PVC sleeve.

[0028] Specifically, the PVC sleeve extends upwards to the pressure plate on the upper part of the core mold base plate, forming a sealing contact surface. The longitudinal template ribs on both sides of the lower part of the pressure plate, together with the pressure plate, constitute a filling cavity structure. Foam adhesive can be injected into the filling cavity through pre-reserved injection holes; after curing, the foam adhesive forms an elastic sealing layer. The longitudinal template ribs can be fixed to the lower part of the pressure plate by welding, with the rib spacing controlled within the range of 50-100mm. Polyurethane foam material is preferred for the foam adhesive, with a foaming ratio controlled at 3-5 times to ensure sealing and compressibility.

[0029] Therefore, this technical solution effectively solves the sealing problem at the top of the PVC sleeve by setting longitudinal template ribs to form a filling cavity and filling it with foam adhesive. After curing, the foam adhesive maintains its elasticity and compressibility while completely filling the cavity gaps, preventing concrete slurry from seeping in. Compared with the existing technology that simply relies on pressure plates for direct sealing, this solution significantly improves sealing reliability and avoids seal failure caused by construction vibration. The cavity filling structure design allows for more uniform and complete foam adhesive filling and facilitates construction operations.

[0030] Furthermore, this application also proposes that the lower part of the threaded tie rod is threaded through a stepped hole and connected to a fixing nut at the lower end, and the fixing nut is welded and fixed to the bottom of the support channel steel provided at the lower part of the bottom template.

[0031] By welding the fixing nut to the supporting channel steel, a rigid fixation of the lower end of the threaded tie rod is achieved. The supporting channel steel not only provides a welding base but also enhances the overall rigidity of the bottom formwork. Furthermore, due to the limited space under the pedestal, a wrench is not needed when tightening the bolts. The fixing device is located below the formwork, which does not interfere with the pouring of the top concrete, improving construction convenience. The compression spring compensates for volume changes during concrete setting, preventing structural cracking caused by stress concentration.

[0032] Furthermore, this application also proposes that the top of the threaded tie rod passes through a pressure plate disposed on the upper part of the core mold base plate, and the pressure plate is movably provided with a clamping nut that is screwed to the threaded tie rod.

[0033] Specifically, the pressure plate is a metal sheet with a thickness of 5-10mm, preferably 8mm. A through hole is located in the center of the pressure plate, with a diameter slightly larger than that of the threaded tie rod to allow it to pass freely. The clamping nut is a standard hexagonal nut made of Q235 steel, and it uses a standard thread to mate with the threaded tie rod.

[0034] Therefore, this technical solution achieves reliable fixation of the core mold through the cooperation of the pressure plate and the clamping nut. When concrete is poured, the core mold is subjected to an upward buoyancy force. At this time, the clamping nut, through the pressure plate, presses the core mold downward, effectively preventing the core mold from floating. Compared with the existing technology that uses a pressure bar for fixation, this solution eliminates the need for a pressure bar at the top, avoiding the occupation of construction space and damage to the core mold, simplifying the construction process and improving construction efficiency. At the same time, the pressure plate and clamping nut have a simple structure, are easy to install and disassemble, and can be reused, reducing construction costs.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A precast beam core mold anti-floating and anti-pull-down fixing device, comprising a bottom template (4) supported on the upper part of a precast beam platform (1), side templates (2) supported by support frames (3) connected to both sides of the bottom template (4), and a core mold (5) supported in the internal space formed by the side templates (2) and the bottom template (4), characterized in that: Several tie rod devices (7) are evenly arranged between the bottom of the core mold (5) and the bottom template (4) to prevent the core mold (5) from floating during casting. The tie rod device (7) includes a threaded tie rod (10) that penetrates the bottom template (4) and the upper end of the core mold (5). A sealed PVC sleeve (18) is provided on the outside of the threaded tie rod (10), and the PVC sleeve (18) is fixed by a sealing and pressing assembly.

2. The precast beam core mold anti-floating and anti-pull-down fixing device according to claim 1, characterized in that: The core mold (5) has a through circular hole (8) on its bottom plate, and the bottom template (4) has a stepped hole (9) in the center. The sealing and pressing assembly is set on the step inside the stepped hole (9).

3. The precast beam core mold anti-floating and anti-pull-down fixing device according to claim 2, characterized in that: The sealing and clamping assembly includes a compression spring (17) located within the stepped hole (9) and fitted onto a threaded tie rod (10) and a gasket (16), on which a PVC sleeve (18) is supported.

4. The precast beam core mold anti-floating and anti-pull-down fixing device according to claim 3, characterized in that: The PVC sleeve (18) extends upward and contacts the pressure plate (12) on the upper part of the core mold (5). The pressure plate (12) has longitudinal template ribs (11) on both sides of its lower part and forms a filling cavity. The filling cavity is filled with foam glue to prevent leakage from the top of the PVC sleeve (18).

5. The precast beam core mold anti-floating and anti-pull-down fixing device according to claim 3, characterized in that: The threaded tie rod (10) is threaded through a stepped hole (9) at the bottom and connected to a fixing nut (15) at the bottom. The fixing nut (15) is welded and fixed to the bottom of the support channel steel (14) at the bottom of the bottom template (4).

6. The precast beam core mold anti-floating and anti-pull-down fixing device according to claim 5, characterized in that: The top of the threaded tie rod (10) passes through the pressure plate (12) provided on the upper part of the bottom plate of the core mold (5), and the pressure plate (12) is movably provided with a clamping nut (13) that is screwed to the threaded tie rod (10).

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