A special inner formwork device for building exhaust passage, flue construction and its construction method

Abstract

The application relates to a special inner formwork device for building exhaust duct and flue construction and a construction method thereof, and relates to the technical field of house building construction. The device comprises a variable-diameter form core assembly, a closing and driving mechanism, a lubricating system, a supporting and positioning assembly and a form frame assembly. The application has the effects of realizing synchronous integral pouring and forming of a flue structure, an exhaust duct well wall and a building main body shear wall and concrete wall body, making the flue structure an organic component of the building main body, realizing the same service life of structural strength, fire resistance, durability and the building main body, and fundamentally improving quality problems such as smoke leakage, odor mixing and cracking.

Description

Technical Field

[0001] This application relates to the technical field of building construction, and in particular to a special internal formwork device and construction method for the construction of building exhaust ducts and flue gas wells. Background Technology

[0002] In high-rise residential building projects, the exhaust ducts (exhaust pipes) in kitchens and bathrooms are core supporting structures that ensure indoor ventilation and exhaust gas emission. The construction quality directly affects the living quality of the residence and the durability of the building. Currently, the mainstream construction method in the industry is to use prefabricated flue construction, that is, to prefabricate thin-walled rectangular pipes with a wall thickness of about 15mm in the factory, transport them to the construction site, and then hoist, splice, and seal them to form the final shape. This traditional construction technique has many unavoidable technical defects in practical applications. First, it suffers from prominent quality problems. The thin-walled structure of prefabricated flues has extremely poor resistance to flexibility and impact, making it prone to damage and cracking during transportation, stacking, and hoisting. The sealing performance of the pipe splicing joints is poor, resulting in common smoke leakage and odor problems after the building is put into use, which seriously affects the living experience. Furthermore, the fire resistance limit of prefabricated flues is low, making it impossible to meet the requirement of having the same service life as the main building.

[0003] Secondly, the construction process is complicated. The prefabricated flue needs to be brought in and constructed a second time after the main structure of the building is completed. This process overlaps with the masonry, wall plastering, water and electricity installation and other processes, causing interference between the processes and significantly extending the overall construction period of the project.

[0004] Third, the overall structure is poor. The prefabricated flue is only connected to the main building wall by filling in the gaps later. The gaps cannot be completely eliminated. The flue is not a main load-bearing structure. Its overall stability and seismic performance are far inferior to those of cast-in-place concrete structures.

[0005] Fourth, the construction safety risks are high. The on-site hoisting of prefabricated flues is a high-altitude vertical transportation operation, and the flue installation work surface is narrow and the construction environment is harsh, which makes it very easy for safety accidents such as collisions and falls to occur. In summary, traditional prefabricated flue construction processes suffer from numerous quality risks, cumbersome procedures, poor structural integrity, low construction safety, and insufficient durability. The industry urgently needs a specialized construction template device and supporting construction method for flue gas wells that can be constructed simultaneously with the main building structure, has reliable forming quality, strong structural integrity, and can be reused. Summary of the Invention

[0006] To address the shortcomings of existing prefabricated flue gas duct construction technologies, such as smoke leakage, odor transfer, weak structural integrity, and complex secondary construction procedures, this application provides a dedicated internal formwork device and its construction method for building exhaust ducts and flue gas wells.

[0007] First aspect The technical solution provided in this application for a special internal formwork device for the construction of building exhaust ducts and flue gas wells is as follows: A special internal formwork device for the construction of building exhaust ducts and flue gas wells, characterized in that it includes a variable diameter mold core assembly, a tensioning and retraction driving mechanism, a lubrication system, a support and positioning assembly, and a mold frame assembly; The core assembly is a hollow rectangular cylindrical structure, which is formed by multiple steel plate shells that are hinged together in sequence through long hinges to form a telescopic four-bar structure. Reinforcing beams are symmetrically fixed on both sides inside the core assembly. The outer contour dimensions of the core assembly in the expanded state match the inner wall dimensions of the flue gas well. The tensioning drive mechanism is located at the center of the mold core assembly and includes a transmission screw, a nut seat, and a support connecting rod. The transmission screw has a drive interface at its end. The nut seat is slidably sleeved on the transmission screw. One end of the support connecting rod is hinged to the nut seat, and the other end is hinged to the reinforcing beam. It can drive the mold core assembly to contract inward or expand outward. The lubrication system includes two oil injection pipes arranged along the height of the mold core assembly. The oil injection pipes are seamless steel pipes with micro oil outlet holes evenly distributed on the pipe walls. The top of the oil injection pipe is an oil injection port, and the bottom is sealed. The oil injection pipes are located close to the sliding contact surface of the long hinge and the template. The supporting and positioning component includes multiple frame-type metal supporting brackets, which are adapted to the size of the flue gas well opening and are fixedly installed at the opening of each flue gas well, and can support and position the core component. The mold frame assembly includes an upper mold frame and a lower mold frame. The upper mold frame is fixedly connected to the top of the mold core assembly, and the lower mold frame is a detachable independent component that is fitted onto the bottom of the mold core assembly for protection and positioning.

[0008] By adopting the above technical solution, this device can achieve synchronous and integrated casting of the flue gas well wall with the building's main shear wall and concrete wall. The flue gas well is integrated into the building's main structure, and its service life is consistent with that of the building. It can eliminate the risks of smoke leakage and odor transfer caused by splicing or damage of prefabricated flues; it eliminates the need for secondary entry and construction of flues, streamlining procedures and accelerating construction progress; it avoids high-risk flue hoisting operations, optimizes the on-site construction environment, and improves construction safety. Furthermore, this solution is equipped with a reusable, easy-to-operate, and reliable dedicated core mold; the core mold integrates telescopic forming, mechanical drive, automatic lubrication, positioning support, and frame protection structures, and uses a variable diameter structure with hinged steel plates to complete demolding, solving the problems of inconvenient demolding and inability to reuse traditional fixed templates; after the integration of multiple structures, the core mold has high forming accuracy, stable structure, and convenient assembly and disassembly. Relying on the hardware structure, it realizes the on-site construction of the flue gas well, replacing the traditional prefabricated flue assembly process and reducing overall construction costs.

[0009] Optionally, the transmission screw is arranged vertically at the center of the mold core assembly, which can control the forward and reverse rotation of the transmission screw to drive the nut seat to perform linear reciprocating motion.

[0010] By adopting the above technical solutions, the structural layout is symmetrically stressed and the driving force is uniform, which can effectively avoid problems such as unilateral displacement of the formwork, local bulging, and asynchronous opening and closing. It can significantly improve the positioning accuracy of the formwork support and the smoothness of demolding, and the manual operation torque is uniform, reducing the difficulty of on-site construction operations.

[0011] Optionally, the support frame is made of angle steel or square steel welded together and anchored to the floor slab and beam, and can bear the self-weight of the formwork and the lateral pressure and vertical load of the concrete pouring.

[0012] By adopting the above technical solutions, the problems of traditional cast-in-place formwork lacking dedicated support, being prone to sinking, running away, and displacement can be effectively solved. The verticality and axial position of the flue gas well are guaranteed to meet the design and specification requirements throughout the process, thereby improving the regularity of the structure formation.

[0013] Optionally, the long hinges are located on the inner sides of the four corners of the steel plate shell and at the connection points of adjacent panels, so that after shrinkage, the template and the concrete wall can form a 5-10mm separation gap.

[0014] By adopting the above technical solution, the formwork can be completely separated from the concrete wall without adhesion, which can effectively avoid bumping and scratching the concrete forming surface during demolding and ensure the integrity of the well wall concrete surface.

[0015] Optionally, the oil injection pipe extends and retracts synchronously with the mold core assembly, and the lubricating medium injected through the top oil injection port can seep out evenly through the micro oil outlet hole to lubricate the hinge rotation parts and the template contact surface.

[0016] By adopting the above technical solutions, problems such as concrete slurry seeping into the hinge gaps and solidifying and jamming, formwork expansion and contraction jamming, and deformation obstruction can be effectively prevented, thereby greatly improving the service life of formwork turnover and reducing equipment failure rate.

[0017] Second aspect A construction method for building exhaust ducts and flue gas wells, utilizing the aforementioned specialized internal formwork device for building exhaust ducts and flue gas wells, includes the following steps: S1. First floor positioning and support installation: Accurately lay out the lines at the flue gas well opening on the top slab of the first floor or basement, fix and install the support bracket, and simultaneously set up the formwork for the outer wall of the flue gas well, reserving the spacing of the designed well wall thickness. S2, Core mold hoisting and positioning: Adjust the inner formwork device to the retracted state, hoist it to the top of the opening with the tower crane and slowly lower it so that the bottom of the formwork sits on the support bracket, calibrate the formwork axis and verticality, and inject oil into the lubrication system through the oil injection port before the construction of S2 to complete the formwork expansion and contraction pretreatment and ensure smooth construction. S3. Template Expansion Formwork Support: By driving the transmission screw to rotate forward using the driving tool, the core assembly is driven to expand outward until the distance between the outer wall of the template and the outer template reaches the design size, thus completing the formwork support positioning. S4. Synchronous binding and pouring: The reinforcing bars around the flue gas well are bound and accepted simultaneously with the reinforcing bars of the main shear wall. They are poured and vibrated to compact simultaneously with the concrete of the main structure. They are cured according to the specifications. The thickness of the flue gas well wall is controlled at 80-100mm. Fine stone concrete is poured and vibrated in layers, with a focus on fine vibration around the formwork and at the root of the well wall. S5. Template shrinkage and demolding: After the concrete reaches the demolding strength, the transmission screw is rotated in the opposite direction to drive the core assembly to shrink inward, so that the template separates from the concrete well wall. In S5, the lubrication system provides continuous lubrication to ensure that the template shrinks without jamming, and the template and the concrete well wall form a uniform separation gap of 5-10mm. S6. Formwork turnover hoisting: Hoist the retracted formwork away from the opening, fit it into the lower formwork frame for protection, and remove or retain the supporting brackets of this floor as needed; S7. Layer-by-layer cyclic construction: Repeat steps S1-S6 at the opening of the previous layer to achieve synchronous pouring construction layer by layer; S8. Top-level finishing treatment: After the roof construction is completed and the formwork is lifted out, the air outlets are finished, rainproof hoods and sealing components are installed to complete the overall construction.

[0018] By adopting the above technical solution, the process of support positioning, template placement, mechanical formwork, synchronous pouring, shrinkage demolding, relocation hoisting, and top-level finishing is formed into a closed-loop flow. This completely eliminates all secondary processes of traditional prefabricated flue gas ducts, including secondary entry, hoisting, splicing, and sealing, enabling simultaneous construction and integrated molding of the flue gas well and the main structure. This significantly reduces the construction period, avoids interference from overlapping operations, and improves overall construction efficiency and on-site standardization.

[0019] Optionally, in S4, the thickness of the flue gas well wall is controlled to be 80-100mm, and fine stone concrete is used for layered pouring and layered vibration, with a focus on fine vibration around the template and at the root of the well wall.

[0020] By adopting the above technical solutions, the 80-100mm thick cast-in-place well wall has significantly improved structural strength and crack resistance compared to the traditional 15mm precast thin-walled flue. At the same time, layered casting and fine vibration in key areas can effectively eliminate quality defects such as honeycomb and looseness, and ensure the structural density of the flue gas well.

[0021] Optionally, in S5, continuous lubrication is achieved through a lubrication system to ensure that the template shrinks without jamming and that a uniform 5-10mm separation gap is formed between the template and the concrete well wall.

[0022] By adopting the above technical solutions, the formed concrete structure can be protected from damage, while the formwork structure can be protected from deformation, greatly increasing the turnover rate of the formwork and reducing the amortization cost of the project.

[0023] Optionally, before construction in step S2, oil is injected into the lubrication system through the oil injection port to complete the pretreatment of template expansion and contraction, ensuring smooth construction operations.

[0024] By adopting the above technical solutions, problems such as dryness and jamming of new templates, structural deformation caused by excessive resistance during initial opening and closing, and bolt damage are reduced, ensuring stable and reliable operation of each layer of construction templates and improving the construction error tolerance rate.

[0025] Optionally, during the S4 construction process, stirrups are set around the wall formwork, and the corners of the stirrups are welded with threaded steel bars to achieve binding, and there are no less than two stirrups in the vertical middle of the wall formwork.

[0026] By adopting the above technical solution, and through the methods of increasing the density of the perimeter stirrups, adding vertical stirrups in the middle, and fixing them with threaded steel bars, the overall rigidity, lateral pressure resistance, and structural integrity of the flue gas well wall are significantly improved. It can effectively resist the lateral pressure of concrete pouring.

[0027] In summary, this application includes at least one of the following beneficial technical effects: 1. Simplified and clear process, significantly shortened construction period. Abandoning the traditional set of independent processes for prefabricated flue production, transportation, stacking, secondary entry, hoisting and splicing, and sealing, flue gas well construction is integrated into the main structure's assembly line construction, without occupying independent construction periods. This completely avoids interference from multiple professional cross-operations, effectively reduces rework, repairs and process waiting time, and significantly improves project construction progress; 2. Safe and convenient operation with a high degree of standardization. Eliminating the high-risk work of sporadic hoisting of prefabricated flues at height, the formwork is hoisted as a whole and mechanically opened and closed, making operation simple, reducing labor intensity, and ensuring a clean and standardized on-site operation, effectively reducing the safety risks of working at height. Relying on a dedicated support and positioning structure, the formwork is precisely positioned, with uniform forming dimensions, controllable construction quality, and can be standardized and replicated, making it suitable for large-scale residential construction. 3. The structure is well-reinforced, resulting in excellent molding quality. The addition of welded stirrups effectively resists the lateral pressure of the poured concrete, preventing defects such as formwork bulging, deformation, and slippage. The well wall is smooth and dense, eliminating the need for extensive post-construction repairs, significantly reducing the workload of later decoration and rectification, and improving the overall appearance and acceptance rate of the project. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the module component according to an embodiment of this application; Figure 3 This is a schematic diagram of the support and positioning component according to an embodiment of this application.

[0029] In the diagram, 1. Mold core assembly; 11. Steel plate shell; 12. Long hinge; 13. Reinforcing beam; 2. Tensioning drive mechanism; 21. Transmission screw; 22. Support connecting rod; 23. Nut seat; 3. Lubrication system; 31. Oil injection pipe; 4. Support and positioning assembly; 41. Frame-type metal support bracket; 5. Mold frame assembly; 51. Upper mold frame; 52. Lower mold frame. Detailed Implementation

[0030] The following is in conjunction with the appendix Figure 1 -Appendix Figure 3 This application will be described in further detail below.

[0031] First aspect Reference Figure 1 , Figure 2 and Figure 3 This application discloses a special internal formwork device for the construction of building exhaust ducts and flue gas wells, including a retractable and variable diameter mold core assembly 1, a retraction and tension drive mechanism 2 for controlling the opening and closing of the formwork, a lubrication system 3 for protecting the movement of the formwork, a support and positioning assembly 4 for positioning and bearing, and a mold frame assembly 5 for protecting the ends of the formwork. The whole device is adapted to the floor-by-floor cast-in-place construction of high-rise residential buildings.

[0032] The mold core assembly 1 is a hollow rectangular cylindrical structure formed by multiple steel plate shells 11 hinged together with long hinges 12. The whole structure is a four-bar telescopic structure. The reinforcing beams 13 are symmetrically fixed on both sides inside the mold core. In the expanded state, the outer contour size is completely matched with the inner wall size of the flue gas well, which is used for concrete pouring and molding. The tensioning drive mechanism 2 is vertically and centrally arranged inside the mold core. It drives the nut seat 23 to move linearly through the forward and reverse rotation of the screw. It works with the support rod 22 to realize the expansion and contraction of the template. The lubrication system 3 is arranged along the side of the template. It expands and contracts synchronously with the template and continuously lubricates the rotating and sliding contact surfaces. The support bracket is made of angle steel and square steel welded together and anchored to each layer of opening to realize the positioning and load-bearing of the template. The upper mold frame 51 is fixed to the top of the mold core, and the lower mold frame 52 can be detachably sleeved at the bottom to realize end protection.

[0033] Second aspect This application also discloses a construction method for building exhaust ducts and flue gas wells, utilizing a special internal formwork device for building exhaust ducts and flue gas wells as described in Example 1.

[0034] S1. First floor positioning and support installation: Accurately lay out the lines at the flue gas well opening on the top slab of the first floor or basement, fix and install the support bracket, and simultaneously set up the formwork for the outer wall of the flue gas well, reserving the spacing of the designed well wall thickness. S2. Core mold hoisting and positioning: Adjust the inner formwork device to the retracted state, hoist it to the top of the opening with the tower crane and slowly lower it so that the bottom of the formwork sits on the support bracket, and calibrate the formwork axis and verticality; S3, Template Expansion Formwork Support: By driving the transmission screw 21 to rotate forward using the driving tool, the mold core assembly 1 is driven to expand outward until the distance between the outer wall of the template and the outer template reaches the design size, thus completing the formwork support positioning; S4. Synchronous binding and pouring: The reinforcing bars around the flue gas well and the reinforcing bars of the main shear wall are bound and accepted simultaneously, and poured and vibrated to compact simultaneously with the concrete of the main structure. They are then cured according to the specifications. During the construction of S4, stirrups are set around the wall formwork, and the corners of the stirrups are welded with threaded steel bars to achieve the binding of the stirrups. There are no less than two stirrups in the vertical middle of the wall formwork. S5. Template shrinkage and demolding: After the concrete reaches the demolding strength, rotate the transmission screw 21 in the opposite direction to drive the core assembly 1 to shrink inward, so that the template separates from the concrete well wall. S6. Formwork turnover hoisting: Hoist the retracted formwork away from the opening, fit it into the lower formwork frame 52 for protection, and remove or retain the supporting brackets of this layer as needed; S7. Layer-by-layer cyclic construction: Repeat steps S1-S6 at the opening of the previous layer to achieve synchronous pouring construction layer by layer; S8. Top-level finishing treatment: After the roof construction is completed and the formwork is lifted out, the air outlets are finished, rainproof hoods and sealing components are installed to complete the overall construction.

[0035] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A specialized internal formwork device for the construction of building exhaust ducts and flue gas wells, characterized in that, It includes a variable diameter mold core assembly (1), a tensioning drive mechanism (2), a lubrication system (3), a support and positioning assembly (4), and a mold frame assembly (5). The core assembly (1) is a hollow rectangular cylindrical structure, which is formed by multiple steel plate shells (11) being hinged together in sequence by long hinges (12) to form a telescopic four-bar structure. Reinforcing beams (13) are symmetrically fixed on both sides inside the core assembly (1). The outer contour size of the core assembly (1) in the expanded state matches the inner wall size of the flue gas well. The tensioning drive mechanism (2) is located at the center of the mold core assembly (1), and includes a transmission screw (21), a nut seat (23) and a support connecting rod (22). The transmission screw (21) has a drive interface at its end. The nut seat (23) is slidably sleeved on the transmission screw (21). One end of the support connecting rod (22) is hinged to the nut seat (23) and the other end is hinged to the reinforcing beam (13), which can drive the mold core assembly (1) to contract inward or expand outward. The lubrication system (3) includes two oil injection pipes (31) arranged along the height direction of the mold core assembly (1). The oil injection pipes (31) are seamless steel pipes with micro oil outlet holes evenly opened on the pipe wall. The top of the oil injection pipe (31) is an oil injection port and the bottom is sealed. The oil injection pipes (31) are set close to the long hinge (12) and the sliding contact surface of the template. The supporting and positioning component (4) includes multiple frame-type metal supporting brackets (41), which are adapted to the size of the flue gas well opening and are fixedly installed at the opening of each flue gas well, and can support and position the core component (1). The mold frame assembly (5) includes an upper mold frame (51) and a lower mold frame (52). The upper mold frame (51) is fixedly connected to the top of the mold core assembly (1). The lower mold frame (52) is a detachable independent component that is fitted onto the bottom of the mold core assembly (1) for protective positioning.

2. The special internal formwork device for the construction of building exhaust ducts and flue gas wells according to claim 1, characterized in that, The transmission screw (21) is arranged vertically at the center of the mold core assembly (1), and can control the forward and reverse rotation of the transmission screw (21) to drive the nut seat (23) to perform linear reciprocating motion.

3. A special internal formwork device for the construction of building exhaust ducts and flue gas wells according to claim 1, characterized in that, The support frame is made of angle steel or square steel welded together and anchored to the floor slabs and beams. It can bear the self-weight of the formwork and the lateral pressure and vertical load of the concrete pouring.

4. A special internal formwork device for the construction of building exhaust ducts and flue gas wells according to claim 1, characterized in that, The long hinge (12) is located on the inner side of the four corners of the steel plate shell (11) and at the connection of adjacent panels. After shrinkage, the template and the concrete wall can form a 5-10mm separation gap.

5. A special internal formwork device for the construction of building exhaust ducts and flue gas wells according to claim 1, characterized in that, The oil injection pipe (31) extends and retracts synchronously with the mold core assembly (1). The lubricating medium injected through the top oil injection port can seep out evenly through the micro oil outlet hole to lubricate the hinge rotation part and the template contact surface.

6. A construction method for building exhaust ducts and flue gas wells, implemented based on the special internal formwork device according to any one of claims 1-5, characterized in that, The construction steps include the following: S1. First floor positioning and support installation: Accurately lay out the lines at the flue gas well opening on the top slab of the first floor or basement, fix and install the support bracket, and simultaneously set up the formwork for the outer wall of the flue gas well, reserving the spacing of the designed well wall thickness. S2. Core mold hoisting and positioning: Adjust the inner formwork device to the retracted state, hoist it to the top of the opening with the tower crane and slowly lower it so that the bottom of the formwork sits on the support bracket, and calibrate the formwork axis and verticality; S3, Template Expansion and Formwork Support: By driving the transmission screw (21) to rotate forward, the core assembly (1) is driven to expand outward until the distance between the outer wall of the template and the outer template reaches the design size, thus completing the formwork support and positioning; S4. Synchronous binding and pouring: The reinforcing bars around the flue gas well are bound and inspected simultaneously with the reinforcing bars of the main shear wall, and poured and vibrated to compact the concrete of the main structure at the same time, and cured in accordance with the specifications. S5. Template shrinkage and demolding: After the concrete reaches the demolding strength, rotate the transmission screw (21) in the opposite direction to drive the core assembly (1) to shrink inward, so that the template separates from the concrete well wall; S6. Formwork turnover hoisting: Hoist the retracted formwork away from the opening, put it into the lower formwork frame (52) for protection, and remove or retain the support bracket of this layer as needed; S7. Layer-by-layer cyclic construction: Repeat steps S1-S6 at the opening of the previous layer to achieve synchronous pouring construction layer by layer; S8. Top-level finishing treatment: After the roof construction is completed and the formwork is lifted out, the air outlets are finished, rainproof hoods and sealing components are installed to complete the overall construction.

7. The construction method according to claim 6, characterized in that: The wall thickness of the flue gas well in S4 is controlled at 80-100mm. Fine stone concrete is poured and vibrated in layers, with a focus on fine vibration around the formwork and at the root of the well wall.

8. The construction method according to claim 6, characterized in that: In the S5, the lubrication system (3) provides continuous lubrication to ensure that the template shrinks without jamming and that the template and the concrete well wall form a uniform separation gap of 5-10mm.

9. The construction method according to claim 6, characterized in that: Before construction of S2, oil is injected into the lubrication system (3) through the oil injection port to complete the pretreatment of template expansion and contraction, ensuring smooth construction operations.

10. The construction method according to claim 6, characterized in that: During the S4 construction process, stirrups are set around the wall formwork, and the corners of the stirrups are welded with threaded steel bars to achieve the binding of the stirrups. There are no less than two stirrups in the vertical middle of the wall formwork.

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