Hollow prestressed floor filling box anti-floating device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHINA CONSTR FOURTH ENG DIV CORP LTD
- Filing Date
- 2025-05-29
- Publication Date
- 2026-06-19
Smart Images
Figure CN224379225U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of building construction technology, and in particular to an anti-buoyancy device for a hollow prestressed floor slab filling box. Background Technology
[0002] Hollow prestressed floor slab filling devices are commonly used in cast-in-place hollow floor slabs. In the construction of floor slabs or bridge concrete, prefabricated hollow prestressed floor slab filling devices are embedded in the concrete floor slab in advance to serve as inner molds. The hollow prestressed floor slab filling devices, together with frame beams, hidden beams, and prestressing, form a composite prestressed hollow floor slab.
[0003] During the cast-in-place process, the hollow prestressed floor slab filling device, located between the bottom and top reinforcement bars of the slab, is relatively light and is subject to the upward buoyancy of the concrete, which pushes the hollow prestressed floor slab filling device to move. Simply binding it with steel wire can easily cause the filling box to shift, squeezing the protective layer of the rib beam. This results in uneven thickness of the protective layer of the rib beam after the poured concrete has solidified, which greatly affects the quality of the hollow floor slab.
[0004] Therefore, existing technologies have defects and shortcomings, and need further improvement and development. Utility Model Content
[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a hollow prestressed floor slab filling box anti-buoyancy device, which aims to solve the problem that the hollow prestressed floor slab filling device in the prior art is prone to cause uneven thickness of the rib beam protective layer.
[0006] The technical solution adopted by this application to solve the technical problem is as follows: a hollow prestressed floor slab filling box anti-buoyancy device, the hollow prestressed floor slab filling box anti-buoyancy device comprising:
[0007] A filling box for filling hollow prestressed floor slabs; the filling box has an upper connecting end and a lower connecting end that are arranged opposite to each other;
[0008] A plurality of upper and lower anti-buoyancy components are detachably disposed in the filling box, and the upper and lower anti-buoyancy components are used to limit the upward floating of the filling box.
[0009] Among them, several of the upper and lower anti-buoyancy components include an upper hook and a lower hook. One end of the lower hook is fastened to the bottom reinforcement of the slab, and the other end of the lower hook is inserted from the lower connecting end and detachably connected to one end of the lower hook. The other end of the upper hook is fastened to the top reinforcement of the slab.
[0010] Optionally, the pull hook includes a lower hook and a lower cavity arranged opposite to each other. The lower hook is used to fasten the bottom reinforcement of the slab. A plurality of limiting cards are evenly arranged around the inner wall of the lower cavity. The lower cavity is provided with a tapered opening at the end opposite to the lower hook, and the tapered opening is provided with internal threads.
[0011] Optionally, the angle between the limiting card and the axis of the lower cavity is set to 30° to 60°.
[0012] Optionally, some of the limiting cards have an integrally formed arc-shaped contact segment and a main body segment, with one end of the main body segment facing away from the arc-shaped contact segment disposed on the inner wall of the fixedly disposed lower cavity; the arc surface of the arc-shaped contact segment is disposed facing away from the lower hook.
[0013] Optionally, the upper hook includes an upper bent hook and an upper screw arranged opposite to each other. The upper bent hook is used to fasten the top reinforcing bar of the slab, and the upper screw is detachably connected to the tapered opening.
[0014] Optionally, the upper screw is provided with a trapezoidal thread, and the arc-shaped contact section can abut against the trapezoidal thread.
[0015] Optionally, the filling box has a central hole in the middle and several reserved holes on the filling box, all of which are used for inserting the upper and lower anti-buoyancy components.
[0016] Optionally, the ratio of the diameter of the reserved hole to the diameter of the lower cavity is 10:6.
[0017] Optionally, friction textures are provided inside the lower hook and the upper hook, and the friction textures are used to increase friction.
[0018] Optionally, the length of the upper screw is set to 1 / 3 to 2 / 3 of the length of the lower cavity.
[0019] Compared with existing technologies, this application provides an anti-buoyancy device for hollow prestressed floor slab filling boxes. This device, through the structural arrangement of upper hooks engaging with the top reinforcement of the slab and lower hooks engaging with the bottom reinforcement of the slab in the upper and lower anti-buoyancy components, can effectively suppress the upward floating tendency of the filling box during concrete pouring. Compared with the technical problems in existing technologies where the filling device is displaced by buoyancy and the compression of the rib beam protective layer leads to inconsistent thickness of the upper and lower protective layers, this anti-buoyancy device for hollow prestressed floor slab filling boxes can convert the buoyancy of the filling box into tensile force between the reinforcing mesh, achieving stable positioning of the filling box within the concrete. This ensures uniform thickness of the rib beam protective layer, further improving the finished quality and construction consistency of the hollow floor slab. Attached Figure Description
[0020] Figure 1This is a top view of the anti-buoyancy device for the hollow prestressed floor slab filling box provided in this application;
[0021] Figure 2 This is a sectional view of the hollow prestressed floor slab filling box anti-buoyancy device provided in this application when assembled with the bottom and top reinforcement bars of the slab;
[0022] Figure 3 This is a cross-sectional view of the upper and lower anti-buoyancy components of the hollow prestressed floor slab filling box anti-buoyancy device provided in this application;
[0023] Figure 4 It is provided in this application Figure 3 Enlarged structural diagram at point A;
[0024] Figure 5 This is a cross-sectional view of the upper and lower anti-buoyancy components of the hollow prestressed floor slab filling box anti-buoyancy device provided in this application when they are not assembled.
[0025] Explanation of reference numerals in the attached figures:
[0026] 10. Hollow prestressed floor slab filling box anti-buoyancy device; 11. Filling box body; 111. Upper connecting end; 112. Lower connecting end; 12. Upper and lower anti-buoyancy components; 121. Upper hook; 122. Lower hook; 113. Central hole; 114. Reserved hole; 1221. Lower hook; 1222. Lower cavity; 1223. Limiting card; 1224. Gradual narrowing opening; 1225. Arc-shaped contact section; 1226. Main body section; 1211. Upper hook; 1212. Upper screw; 1213. Trapezoidal thread; 20. Bottom reinforcement of slab; 21. Top reinforcement of slab. Detailed Implementation
[0027] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0028] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, 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 this application, unless otherwise stated, "a plurality of" means two or more.
[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0030] Please refer to the following: Figures 1 to 5 This application provides a hollow prestressed concrete floor slab filling box anti-buoyancy device 10, which mainly consists of a filling box body 11 and several upper and lower anti-buoyancy components 12. The filling box body 11 is embedded in the hollow concrete floor slab, and its upper connecting end 111 and lower connecting end 112 are respectively used to cooperate with the bottom reinforcement 20 and top reinforcement 21 of the floor slab reinforcement system. Specifically, the bottom reinforcement 20 is the reinforcement located at the bottom of the formwork, and the top reinforcement 21 is the reinforcement located at the top of the formwork, which is an existing structure. Several upper and lower anti-buoyancy components 12 are inserted into the filling box body 11 through pre-reserved holes 114. Mainly through the direct interlocking of the upper and lower anti-buoyancy components 12 with the bottom reinforcement 20 and top reinforcement 21, the buoyancy of the filling box is converted into tensile force between the reinforcement mesh, forming a mechanical balance and increasing the anti-buoyancy force of the slab reinforcement on the filling box during concrete pouring; ensuring that the filling box does not shift or float during concrete pouring, thus guaranteeing the quality of the pouring.
[0031] The upper and lower anti-buoyancy components 12 include an upper hook 121 and a lower hook 122. One end of the lower hook 122 has a lower bend 1221 for securing the bottom reinforcing bar 20, and the other end is connected to a lower cavity 1222. The lower cavity 1222 has several limiting clips 1223 arranged at angles of 30° to 60° inside. Specifically, the axial angle between the limiting clips 1223 and the lower cavity 1222 is set to 30° to 60°. A tapered opening 1224 is provided at the end opposite to the lower bend 1221, and the inner wall of the tapered opening 1224 is provided with trapezoidal threads 1213. The upper hook 121 includes an upper bend 1211 and an upper screw 1212. The upper bend 1211 is secured to the top reinforcing bar 21, and the upper screw 1212 is screwed into the tapered opening 1224 of the lower cavity 1222. The outer wall of the upper screw 1212 is also provided with a trapezoidal thread 1213 that matches the lower cavity 1222, so as to achieve a reliable and detachable connection with the lower cavity 1222.
[0032] The working process of the device is as follows: After the floor slab formwork and reinforcing steel are laid, the filling box 11 is placed on the bottom reinforcing steel 20 of the slab. The reserved hole 114 is used to guide the installation of the upper and lower anti-buoyancy components 12. The worker inserts the lower pull hook 122 through the lower connecting end 112 of the filling box 11; then inserts the upper pull hook 121 from the upper connecting end 111, and rotates the upper screw 1212 to make its trapezoidal thread 1213 part screwed into the internal thread of the lower cavity 1222. The tension between the upper pull hook 121 and the lower pull hook 122 is adjusted by the spiral push method. When the tension meets the actual needs, the lower pull hook 122 is fixed to the bottom reinforcing steel 20 of the slab by the lower hook 1221, and the upper hook 1211 is hooked onto the top reinforcing steel 21 of the slab. The lateral length of the lower hook 1221 is much larger than the diameter of the reserved hole 114. The limiting card 1223 in the lower cavity 1222 gradually provides axial limiting and rotational anti-slip functions during the thread engagement with the upper screw 1212. The arc-shaped contact section 1225 abuts against the trapezoidal thread 1213 to prevent loosening or deflection due to vibration, thereby ensuring the stability of the anti-buoyancy force during concrete pouring.
[0033] To enhance the stability and anti-detachment capability of the device, the part of the hook that contacts the reinforcing bar is equipped with a friction texture. Specifically, the friction texture can be arranged in a dotted pattern to increase contact protrusions, or it can be set as an anti-slip texture; this increases the friction between the hook and the reinforcing bar, thereby improving the overall anti-buoyancy performance of the device. The diameter of the reserved hole 114 is set to a ratio of 10:6 with the diameter of the lower cavity 1222 to achieve assembly gap control and enhance the guiding role of the anti-buoyancy component during installation. The length of the upper screw 1212 is controlled within the range of 1 / 3 to 2 / 3 of the length of the lower cavity 1222.
[0034] The hollow prestressed floor slab filling box anti-buoyancy device 10, with the filling box body 11 and the upper and lower anti-buoyancy components 12 working in coordination, utilizes the upper hook 121 and lower hook 122 to engage the top reinforcement 21 and bottom reinforcement 20 of the slab, and uses the axial tension generated by the screw adjustment to counteract the buoyancy force on the filling box body 11 during concrete pouring. Specifically, the transverse diameter of the upper hook 1211 is much larger than the diameter of the reserved hole 114, and the upper surface of the filling box body 11 abuts against the upper hook 1211, converting the buoyancy of the filling box into the tension between the reinforcement mesh. By replacing the upper hook 1211 with different sizes, the distance between the filling box body 11 and the top reinforcement of the slab can be effectively controlled, effectively preventing the floating problem of the filling box body 11 and ensuring that the thickness of the rib beam protective layer is consistent from top to bottom.
[0035] Please refer to the following: Figures 1 to 3 In some embodiments, the hollow prestressed floor slab filling box anti-buoyancy device 10 includes a filling box 11 and a plurality of upper and lower anti-buoyancy components 12; the filling box 11 is used to fill the hollow prestressed floor slab; the filling box 11 has an upper connecting end 111 and a lower connecting end 112 arranged opposite to each other; the plurality of upper and lower anti-buoyancy components 12 are detachably arranged in the filling box 11, and the upper and lower anti-buoyancy components 12 are used to restrict the filling box 11 from floating upward; wherein, each of the plurality of upper and lower anti-buoyancy components 12 includes an upper hook 121 and a lower hook 122, one end of the lower hook 122 is fastened to the bottom reinforcement 20 of the slab, the other end of the lower hook 122 is inserted from the lower connecting end 112 and detachably connected to one end of the lower hook 122, and the other end of the upper hook 121 is fastened to the top reinforcement 21 of the slab. Furthermore, through the structural arrangement of the upper hook 121 engaging with the top reinforcement 21 and the lower hook 122 engaging with the bottom reinforcement 20 in the upper and lower anti-buoyancy components 12, the upward tendency of the filling box 11 can be effectively suppressed during concrete pouring. Compared with the technical problems in the prior art where the filling device is pushed by buoyancy and shifts, and the compression of the rib beam protective layer leads to inconsistent thickness of the upper and lower protective layers, the hollow prestressed floor slab filling box anti-buoyancy device 10 can convert the buoyancy of the filling box 11 into the tension between the steel mesh, realizing the stable positioning of the filling box 11 inside the concrete, thereby ensuring the uniform thickness of the rib beam protective layer and further improving the finished quality and construction consistency of the hollow floor slab.
[0036] Please refer to the following: Figures 1 to 3In some embodiments, the pull-down hook 122 includes a lower hook 1221 and a lower cavity 1222 arranged opposite to each other. The lower hook 1221 is used to hold the bottom reinforcing bar 20 of the slab. A plurality of limiting cards 1223 are evenly arranged around the inner wall of the lower cavity 1222. The end of the lower cavity 1222 opposite to the lower hook 1221 is provided with a tapered opening 1224, and the tapered opening 1224 is provided with internal threads. Thus, the lower hook 1221 can firmly hold the bottom reinforcing bar 20 of the slab, enhancing the load-bearing capacity and anti-detachment performance of the anti-buoyancy component. The limiting cards 1223 can form an anti-rotation and anti-displacement function with the upper threaded structure. The tapered opening 1224 and the threaded upper screw 1212 structure can realize the adjustable connection of the upper hook 121, which is convenient for installation and adjustment according to different slab thicknesses during construction, improving adaptability and construction efficiency.
[0037] Please refer to the following: Figures 3 to 4 In some embodiments, the angle between the limiting card 1223 and the axis of the lower cavity 1222 is set to 30° to 60°. Specifically, the limiting card 1223 can be made of 3mm stainless steel plate and can be staggered vertically along the interior of the lower cavity 1222, specifically, there can be 4, 6, or 8 of them. Furthermore, by setting the angle between the limiting card 1223 and the axis of the lower cavity 1222 to 30° to 60°, it helps to generate an oblique clamping force during the screwing of the upper screw 1212, which not only enhances the radial support of the screw but also improves the overall seismic resistance and anti-loosening ability. During concrete pouring and vibrator operation, it can effectively prevent the threaded structure from loosening or disengaging, further ensuring the stability of the filling box 11 and the uniformity of the overall floor structure.
[0038] Please refer to the following: Figure 4 In some embodiments, several of the limiting cards 1223 have an integrally formed arc-shaped contact section 1225 and a main body section 1226. One end of the main body section 1226 facing away from the arc-shaped contact section 1225 is disposed on the inner wall of the lower cavity 1222. The arc surface of the arc-shaped contact section 1225 faces away from the lower hook 1221. This utilizes an integrally formed arc-shaped contact section 1225 and main body section 1226. The arc-shaped contact section 1225 better conforms to the contour of the trapezoidal thread 1213 on the upper screw 1212, forming a more stable surface contact friction force during screwing, thus improving locking performance. The main body section 1226 is fixed to the inner wall of the lower cavity 1222, providing structural support. The integral molding simplifies the manufacturing process and ensures integrity and resistance to deformation under stress.
[0039] Please refer to the following: Figure 2In some embodiments, the upper hook 121 includes an upper bent hook 1211 and an upper screw 1212 arranged opposite to each other. The upper bent hook 1211 is used to hold the top reinforcing bar 21 of the slab, and the upper screw 1212 is detachably connected to the tapered opening 1224. The upper bent hook 1211 achieves a rigid connection with the upper reinforcing bar, increasing the anti-buoyancy stability of the filling box 11; the upper screw 1212 is threadedly connected to the lower cavity 1222, forming an adjustable structure that allows for flexible adjustment of the anti-buoyancy component length under different construction heights or reinforcing bar position errors.
[0040] Please refer to the following: Figure 4 In some embodiments, the upper screw 1212 is provided with a trapezoidal thread 1213, and the arc-shaped contact section 1225 can abut against the trapezoidal thread 1213. Specifically, the pitch of the trapezoidal thread 1213 is set to 2mm, the tooth angle is 30°, and the tooth profile is an isosceles trapezoid. Compared with a triangular thread with a tooth angle of 60°, the transmission efficiency is increased by 25%. The arc-shaped contact section 1225 has a certain degree of elasticity and can engage and lock into the groove of the trapezoidal thread 1213. This allows it to cooperate with the contact interface of the arc-shaped contact section 1225. Compared with ordinary triangular threads, the trapezoidal thread 1213 has higher transmission efficiency and a larger contact surface, thus enabling more precise adjustment of the distance between the upper hook 1211 and the lower hook 1221 during screwing. The trapezoidal thread 1213 also has stronger shear resistance, which helps to maintain structural stability during concrete pouring vibration.
[0041] Please refer to the following: Figure 1 In some embodiments, a central hole 113 is provided in the middle of the filling box 11, and a plurality of reserved holes 114 are provided on the filling box 11. These reserved holes 114 are used for inserting the upper and lower anti-buoyancy components 12. Specifically, the distance between the reserved holes 114 on both sides and the side wall can be set to 120mm to 140mm. Furthermore, the uniform spacing of the reserved holes 114 ensures that the anti-buoyancy components are evenly arranged and the force transmission path is reasonable, thereby avoiding the problem of localized buoyancy concentration causing the filling box to tilt.
[0042] Please refer to the following: Figure 1 In some embodiments, the diameter ratio of the reserved hole 114 to the diameter of the lower cavity 1222 is 10:6. Furthermore, by optimizing the ratio between the diameter of the reserved hole 114 and the diameter of the lower cavity 1222, a proper fit between the hole and the anti-buoyancy component is achieved. This facilitates insertion and alignment during construction, and also provides sufficient clamping and support during concrete pouring to prevent the anti-buoyancy component from loosening or shifting, thus contributing to the stable fixation of the filling box 11 under complex working conditions.
[0043] In some embodiments, friction textures are provided inside the lower hook 1221 and the upper hook 1211, and these textures are used to increase friction. Furthermore, the friction textures inside the lower hook 1221 and the upper hook 1211 help enhance the surface contact friction between the hook and the rebar. This not only prevents the hook from slipping due to construction vibration or rebound, but also improves the overall stability of the connection. Simultaneously, the friction textures also act like an interlocking mechanism on the surface of the rebar, changing the adhesion of the anti-buoyancy device to the rebar from point contact to surface friction, thus enhancing the force transmission and fixation effect.
[0044] Please refer to the following: Figure 2 In some embodiments, the length of the upper screw 1212 is set to 1 / 3 to 2 / 3 of the length of the lower cavity 1222. This ensures that the upper screw 1212 can fully enter the lower cavity 1222 to form an effective connection, while avoiding excessive length that could cause interference in assembly space or conflict with upper components. Controlling the length within this proportional range achieves a balance between structural strength and ease of installation, improving the practicality of the hollow prestressed floor slab filling box anti-buoyancy device 10.
[0045] Please refer to the following: Figure 5 , Figure 5 Another upper and lower anti-buoyancy component 12 is provided. The lower hook 1221 is provided with a lower screw at its end. The lower screw can be adjusted by screwing it into the lower cavity 1222, thereby adjusting the length of the lower hook 1221 and the lower cavity 1222.
[0046] In summary, this application provides an anti-buoyancy device for a hollow prestressed floor slab filling box. The device includes: a filling box for filling a hollow prestressed floor slab; the filling box has an upper connecting end and a lower connecting end arranged opposite to each other; and a plurality of upper and lower anti-buoyancy components, which are detachably disposed within the filling box and used to limit the upward floating of the filling box. Each of the upper and lower anti-buoyancy components includes an upper hook and a lower hook. One end of the lower hook is fastened to the bottom reinforcement of the slab, and the other end of the lower hook is inserted from the lower connecting end and detachably connected to one end of the lower hook. The other end of the upper hook is fastened to the top reinforcement of the slab. Furthermore, through the structural arrangement of the upper hook engaging with the top reinforcement and the lower hook engaging with the bottom reinforcement of the slab in the upper and lower anti-buoyancy components, the upward floating tendency of the filling box can be effectively suppressed during concrete pouring. Compared to existing technologies where the filling device is displaced by buoyancy and the compression of the rib beam protective layer leads to inconsistent thickness of the upper and lower protective layers, the hollow prestressed floor slab filling box anti-buoyancy device can convert the buoyancy of the filling box into the tension between the steel mesh, achieving stable positioning of the filling box inside the concrete, thereby ensuring uniform thickness of the rib beam protective layer and further improving the finished quality and construction consistency of the hollow floor slab.
[0047] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A hollow prestressed floor filling box anti-floating device, characterized in that, include: A filling box for filling hollow prestressed floor slabs; the filling box has an upper connecting end and a lower connecting end that are arranged opposite to each other; A plurality of upper and lower anti-buoyancy components are detachably disposed in the filling box, and the upper and lower anti-buoyancy components are used to limit the upward floating of the filling box. Among them, several of the upper and lower anti-buoyancy components include an upper hook and a lower hook. One end of the lower hook is fastened to the bottom reinforcement of the slab, and the other end of the lower hook is inserted from the lower connecting end and detachably connected to one end of the lower hook. The other end of the upper hook is fastened to the top reinforcement of the slab.
2. The anti-buoyancy device for the hollow prestressed floor slab filling box according to claim 1, characterized in that, The pull hook includes a lower hook and a lower cavity arranged opposite to each other. The lower hook is used to fasten the bottom reinforcement of the slab. A number of limiting cards are evenly arranged around the inner wall of the lower cavity. The lower cavity has a tapered opening at the end opposite to the lower hook, and the tapered opening is provided with internal threads.
3. The hollow prestressed floor filling box anti-floating device according to claim 2, characterized in that, The angle between the limiting card and the axis of the lower cavity is set to 30° to 60°.
4. The anti-buoyancy device for the hollow prestressed floor slab filling box according to claim 2, characterized in that, The limiting cards have an integrally formed arc-shaped contact section and a main body section. One end of the main body section facing away from the arc-shaped contact section is disposed on the inner wall of the lower cavity. The arc surface of the arc-shaped contact section is facing away from the lower hook.
5. The hollow prestressed floor infill box anti-floating device according to claim 4, characterized in that, The upper hook includes an upper bent hook and an upper screw rod arranged opposite to each other. The upper bent hook is used to fasten the top reinforcing bar of the slab, and the upper screw rod is detachably connected to the tapered opening.
6. The hollow prestressed floor infill box anti-floating device according to claim 5, characterized in that, The upper screw is provided with a trapezoidal thread, and the arc-shaped contact section can abut against the trapezoidal thread.
7. The anti-buoyancy device for the hollow prestressed floor slab filling box according to claim 4, characterized in that, The filling box has a central hole in the middle and several reserved holes on the filling box, all of which are used for inserting the upper and lower anti-buoyancy components.
8. The anti-buoyancy device for the hollow prestressed floor slab filling box according to claim 7, characterized in that, The ratio of the diameter of the reserved hole to the diameter of the lower cavity is 10:
6.
9. The anti-buoyancy device for the hollow prestressed floor slab filling box according to claim 5, characterized in that, The lower and upper hooks are provided with friction textures, which are used to increase friction.
10. The anti-buoyancy device for the hollow prestressed floor slab filling box according to claim 9, characterized in that, The length of the upper screw is set to 1 / 3 to 2 / 3 of the length of the lower cavity.