A fire door and a multi-layer fire resistant composite filler construction thereof

Abstract

This invention belongs to the field of fire protection technology, specifically relating to a fire door and its multi-layer fire-resistant composite filling structure, including a door leaf and an internal frame; several elastic tie members arranged in an array are provided between the door leaf and the internal frame; a stress-relieving gap is formed between the door leaf and the internal frame to allow for thermal expansion displacement of the door leaf; stress-relieving grooves are respectively provided at the center of the mating end faces of the two internal frames, forming a cavity after splicing; a T-shaped sliding connecting plate is provided in the cavity, and an elongated hole is opened on the transverse flange of the T-shaped sliding connecting plate, which is connected to the web plate of the internal frame by a bolt passing through the elongated hole. This invention can avoid the rigid tension between the door leaf and the frame under the action of the piston wind pressure in the subway, and can also release the longitudinal thermal stress when the fire door frame is heated and expanded, preventing the frame from bending as a whole.

Description

Technical Field

[0001] This invention belongs to the field of fire protection facilities technology, specifically relating to a fire door and its multi-layer fire-resistant composite filling structure. Background Technology

[0002] Fire doors are fire-resistant partitions that can meet the requirements of fire resistance stability, integrity and heat insulation within a specified time. They are mainly used in fire compartments, evacuation stairwells, vertical shafts and other places. They are composed of door frames, door leaves and accessories such as fire-resistant hinges and door closers. According to the material, they are divided into wood, steel and steel-wood types. According to the structural type, they include categories with fire-resistant glass and with transom windows.

[0003] Problems with existing technology: In existing technologies, subway fire doors typically employ a rigid connection where the panel and frame are fully welded to ensure fire resistance. However, those skilled in the art have overlooked the alternating characteristics of subway piston wind pressure and the difference in expansion coefficients between stainless steel and channel steel during a fire. This makes the existing rigid structure highly susceptible to wind pressure bulging and thermal distortion. Specifically, when subway piston wind pressure acts on the panel, the wind pressure load acts directly on the connection point between the channel steel frame and the panel. The fully welded rigid connection is indeed highly prone to causing the door leaf to bulge, twist, or even tear the weld. Furthermore, during a fire, the thermal expansion at high temperatures causes stress concentration at the weld joints of the frame, leading to bending (bow-shaped deformation) of the entire frame and consequently causing the door leaf to jam. Summary of the Invention

[0004] The purpose of this invention is to provide a fire door and its multi-layer fire-resistant composite filling structure, which can avoid the rigid tension between the door leaf and the frame under the action of the piston wind pressure in the subway, and can also release the longitudinal thermal stress when the fire door frame is heated and expanded, preventing the frame from bending as a whole.

[0005] The specific technical solution adopted by this invention is as follows: A fire door and its multi-layer fire-resistant composite filling structure, including a door leaf and an internal frame; The fire-resistant filling structure of the fire door adopts a multi-layer composite structure, which consists of stainless steel door leaf, fireproof board, fireproof door core board, fireproof board, and door leaf from the outside to the inside. The fireproof board withstands thermal shock and blocks the transmission of high temperature to the fireproof door core board. The fireproof door core board dehydrates and absorbs heat at high temperature, thus slowing down the temperature rise. Several elastic tie members arranged in an array are provided between the door leaf and the internal frame; the elastic tie members are fixedly welded to the internal frame at one end and connected to the door leaf by bolts at the other end, forming a stress relief gap between the door leaf and the internal frame that allows for thermal expansion displacement of the door leaf. The internal frame consists of an inner frame arranged in a crisscross pattern and an outer frame arranged around the edge of the fire door; The two inner skeletons are provided with stress relief grooves at the center of their mating end faces. After splicing, they form a cavity. A T-shaped sliding connecting plate is provided in the cavity. An elongated hole is opened on the transverse flange of the T-shaped sliding connecting plate. The plate is connected to the web of the inner skeleton by a bolt passing through the elongated hole.

[0006] Furthermore, the elastic tie member is made of spring steel sheet, and the threaded end of the elastic tie member connected to the door leaf has an elongated hole. The elastic tie member is connected to the door leaf by a bolt passing through the elongated hole to provide longitudinal sliding release.

[0007] Furthermore, a polygonal bending section is provided at the junction of the welded end and the screwed end. The polygonal bending section is used to maintain the bending strength of the elastic tie under normal working conditions, and elastic deformation only occurs when the stress on the door leaf is greater than the bending strength. An inclined section is provided between the polygonal bending section and the end of the screw connection. The inclined section serves as the main section where the elastic tie member undergoes elastic deformation under stress, supporting the door leaf to undergo thermal expansion displacement within the stress release gap.

[0008] Furthermore, each square meter of the internal frame is provided with 16-25 elastic tie members with a spacing of 200-250mm.

[0009] Furthermore, the stress relief gaps between the internal frame and the front and rear door panels are filled with fireproof boards.

[0010] Furthermore, the length of the elongated hole on the transverse flange of the T-shaped sliding connecting plate is 4-6 mm larger than the diameter of the bolt, which is used to provide longitudinal sliding release.

[0011] Furthermore, the stress relief groove is a V-shaped groove. The V-shaped grooves of the two inner skeletons are spliced ​​together to form a rhomboid cavity, which is filled with flexible fireproof material.

[0012] Furthermore, the inner frame serves as a reinforcing frame, and the frames are welded and fixed together to form a frame grid structure, with the fireproof door core panel filling the interior of the frame grid structure. The fireproof board is placed between the door leaf and the fireproof door core board as a transition layer.

[0013] Furthermore, it also includes door frame tie rods and door frame skeletons as door frame structures, and the door frame is wrapped around the surface of the door frame skeleton along the laying direction of the frame.

[0014] Furthermore, a fire-resistant expansion sealant 1 and a fire-resistant expansion sealant 2 are provided in the gap between the door leaf and the door frame. The fire-resistant expansion sealant 1 and the fire-resistant expansion sealant 2 expand and fill the gap under the high temperature of a fire.

[0015] The technical effects achieved by this invention are as follows: The fire door designed in this invention has a multi-layer composite structure for its fire-resistant filling. Even when exposed to high temperatures during a fire, the door structure can still maintain a certain structural strength and provide in-plane support, so that the fire door structure can maintain its integrity for a certain period of time even under the most unfavorable conditions.

[0016] When the wind pressure from the subway piston acts on the door leaf, the elastic tie is stretched or compressed, effectively transferring the wind pressure load to the frame and preventing the panel from bulging. In the event of a fire, when the door leaf expands due to heat, the door leaf can also cause the elastic tie to undergo slight elastic bending deformation, absorbing the expansion displacement of the door leaf and avoiding rigid pulling between the door leaf and the frame.

[0017] When the fire door frame expands longitudinally due to heat, the longitudinal thermal stress is released by the bolts at both ends of the T-shaped sliding connecting plate sliding in the corresponding elongated holes, or by the elastic deformation of the V-shaped groove under ultra-high temperature, thus preventing the frame from bending as a whole. Attached Figure Description

[0018] Figure 1 This is a plan view of the pull / sliding door surface of a fire door provided in an embodiment of the present invention; Figure 2 This is a schematic diagram showing the distribution of the internal frame of a fire door provided in an embodiment of the present invention; Figure 3 yes Figure 1 Enlarged cross-sectional view of section AA; Figure 4 yes Figure 1 Enlarged cross-sectional view of section BB in the middle; Figure 5 This is a schematic diagram of the connection between the partial inner frame and the door leaf provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the docking of two inner skeletons provided in an embodiment of the present invention.

[0019] The attached diagram lists the components represented by each number as follows: 1. Door frame; 2. Door leaf; 3. Hinges; 4. Fireproof locks; 5. Inner frame; 6. Outer frame; 7. Door frame tie rods; 8. Fireproof expansion seal 1; 9. Fireproof expansion seal 2; 10. Fireproof door core panel; 11. Fireproof board; 12. Door frame frame; 13. Elastic tie rods; 1301. Welded end; 1302. Screwed end; 14. T-shaped sliding connecting plate. Detailed Implementation

[0020] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0021] like Figures 1-6 As shown, a fire door and its multi-layer fire-resistant composite filling structure include a door leaf 2 and an internal frame; the internal frame consists of an inner frame 5 arranged in a crisscross pattern and an outer frame 6 arranged around the edge of the fire door.

[0022] Example 1: See attached document Figures 2-4 The fire-resistant filling structure of the fire door adopts a multi-layer composite structure, which consists of stainless steel door leaf 2, fireproof board 11, fireproof door core board 10, fireproof board 11, and door leaf 2 from the outside to the inside; the inner frame 5 serves as a reinforcing frame, and the frames are welded and fixed to form a frame grid structure, with the fireproof door core board 10 filling the inside of the frame grid structure; the fireproof board 11 is set between the door leaf 2 and the fireproof door core board 10 as a transition layer.

[0023] See attached document Figures 3-4 It also includes a door frame tie rod 7 and a door frame skeleton 12 as the door frame structure, and the door frame 1 is wrapped around the surface of the door frame skeleton 12 along the frame laying direction; the door leaf 2 and the door frame 1 are hinged together by hinges 3 installed on the edge, and a fireproof lock 4 is installed on the sliding surface of the door leaf 2; a fireproof expansion seal 1 8 and a fireproof expansion seal 2 9 are provided in the gap between the door leaf 2 and the door frame 1, and the fireproof expansion seal 1 8 and the fireproof expansion seal 2 9 expand and fill the gap under the high temperature of the fire.

[0024] According to the above structure, during a fire, the temperature of the 1.5mm stainless steel door leaf 2 on the fire side rises rapidly, the material's yield strength decreases, and the door leaf 2 undergoes thermal expansion. Constrained by the internal frame, it generates compressive stress, which far exceeds the yield strength, causing the door leaf 2 to undergo plastic deformation. Next, the 10mm fireproof board 11 acts to block the transmission of high temperature to the fireproof door core board 10 and withstands thermal shock, generating thermal cracks while maintaining integrity. Furthermore, the 73mm fireproof door core board 10, primarily made of magnesium oxide, has a low thermal conductivity. The core material can dehydrate and absorb heat at high temperatures, delaying the temperature rise, shrinking in volume, and generating shrinkage stress. In summary, even when facing high temperatures during a fire, the door structure can still maintain a certain structural strength, providing in-plane support, allowing the fireproof door structure to maintain its integrity for a certain period even under the most unfavorable conditions.

[0025] Example 2: See attached document Figure 5 Several elastic tie members 13 arranged in an array are provided between the door leaf 2 and the internal frame; the elastic tie members 13 are fixedly welded to the internal frame through a welding end 1301 at one end, and the screw end 1302 at the other end is connected to the door leaf 2 by bolts, forming a stress relief gap between the door leaf 2 and the internal frame that allows the thermal expansion displacement of the door leaf 2; fireproof boards 11 are filled in the stress relief gap between the internal frame and the front and rear door leaves 2. See attached document Figure 5 The elastic tie member 13 is made of spring steel sheet, and the threaded end 1302 of the elastic tie member 13 connected to the door leaf 2 has an elongated hole. The elastic tie member 13 is connected to the door leaf 2 by a bolt passing through the elongated hole to provide longitudinal sliding release. 16-25 elastic tie members 13 are arranged in the internal frame per square meter, with a spacing of 200-250mm. See attached document Figure 5 A polygonal bend is provided at the junction of the welded end 1301 and the screwed end 1302. The polygonal bend is used to maintain the bending strength of the elastic tie member 13 under normal working conditions, and elastic deformation only occurs when the stress on the door leaf 2 is greater than the bending strength. An inclined section is provided between the polygonal bend and the end of the screwed end 1302. The inclined section is the main section where the elastic tie member 13 undergoes elastic deformation under stress, and supports the door leaf 2 to undergo thermal expansion displacement within the stress release gap.

[0026] According to the above structure, in scenario one: the elastic tie member 13 has high support stiffness in the direction perpendicular to the door leaf 2. When the door leaf 2 is under the high frequency alternating positive and negative pressure generated by the subway train entering and leaving the station, when the wind pressure acts on the door leaf 2, the dense elastic tie member 13, like several miniature springs, effectively disperses and transmits the uniform wind pressure on the door leaf 2 to the internal frame, namely the channel steel-shaped inner frame 5 and outer frame 6, to prevent the door leaf 2 from being locally dented or bulging. Scenario 2: During a fire, the heating rate and thermal expansion coefficient of the 1.5mm stainless steel door leaf 2 are different from those of the thick internal channel steel frame. The elastic tie member 13 itself has a large elastic deformation margin. When the door leaf 2 is heated and expands longitudinally, it causes the flexible connection end of the elastic tie member 13 to undergo slight bending or stretching deformation, converting the rigid displacement of thermal expansion into the elastic potential energy of the elastic tie member 13. In addition, the bolt hole connecting the elastic tie member 13 to the door leaf 2 is set as an elongated oval hole, which allows the bolt to slide slightly in the elongated oval hole when the door leaf 2 expands, completely releasing thermal stress and achieving flexible yielding.

[0027] Example 3: See attached document Figure 6 The two inner frame frames 5 are respectively provided with stress relief grooves at the center of their mating end faces. After splicing, they form a cavity. A T-shaped sliding connection plate 14 is provided in the cavity. The stress relief groove is a V-shaped groove. After splicing the V-shaped grooves of the two inner frame frames 5 mating end faces, they form a rhomboid cavity. The rhomboid cavity is filled with flexible fireproof material. See attached document Figure 6 The T-shaped sliding connecting plate 14 has an elongated hole on its transverse flange, which is connected to the web of the inner frame 5 by a bolt 2 passing through the elongated hole. The length of the elongated hole on the transverse flange of the T-shaped sliding connecting plate 14 is 4-6 mm larger than the diameter of the bolt 2, which is used to provide longitudinal sliding release.

[0028] According to the above structure, in scenario one: when under positive pressure, the inner frame 5 transmits the wind pressure stress it bears along the web of the channel steel. When it is transmitted to the T-shaped sliding connection plate 14, the flange of the T-shaped sliding connection plate 14 bears shear force and transmits the load to the next channel steel inner frame 5, then to the four sides of the door frame 1, and finally disperses it to the tunnel structure; conversely, when under negative pressure, the door leaf 2 undergoes outward bending deformation, the elastic tie member 13 is stretched, and provides reverse support force, which is the same as the positive pressure condition but in the opposite direction. Scenario 2: During a fire, in the initial stage of temperature rise, the channel steel inner frame 5 begins to expand linearly, and the stainless steel door leaf 2 expands due to heat. According to the expansion coefficient, its expansion speed is faster than that of the channel steel. A temperature difference and expansion difference are generated between the door leaf 2 and the inner frame 5. The bolts at both ends of the T-shaped sliding connecting plate 14 begin to slide slightly in the elongated holes. The V-shaped groove wall of the diamond-shaped cavity begins to bear compressive stress, but is within the range of elastic deformation. As the fire enters a high-temperature state, the temperature of the channel steel inner frame 5 rises rapidly, and the bolts slide fully in the elongated holes. The left and right sides slide simultaneously to release the expansion amount. In addition, the remaining expansion amount is released through the following means: ① elastic deformation of the diamond-shaped cavity, with the V-shaped groove wall expanding outward; ② bending deformation of the entire door leaf 2, slightly bending towards the low-pressure side; ③ the reserved installation gap at the connection between the door leaf 2 and the door frame 1 absorbs the remaining expansion amount.

[0029] The working principle of this invention is as follows: During a fire, the temperature of the 1.5mm stainless steel door leaf 2 on the fire side rises rapidly, the material's yield strength decreases, and the door leaf 2 undergoes thermal expansion. Constrained by the internal frame, it generates compressive stress, which far exceeds the yield strength, causing the door leaf 2 to undergo plastic deformation. Next, the 10mm fireproof board 11 is used to block the transmission of high temperature to the fireproof door core board 10 and withstands thermal shock, generating thermal cracks but maintaining integrity. In addition, the 73mm fireproof door core board 10 has a low thermal conductivity, and the core material can dehydrate and absorb heat at high temperatures, delaying the temperature rise, shrinking in volume, and generating shrinkage stress. Regarding the channel steel inner frame 5, which serves as a reinforcing skeleton, the yield strength decreases due to the fire temperature, and the skeleton undergoes uneven thermal expansion. The longitudinal expansion stress is released through the T-shaped sliding connection plate 14. Specifically, the bolts at both ends of the T-shaped sliding connection plate 14 slide in the elongated holes, thereby releasing the expansion stress of the skeleton; at the same time, it bears shear force to ensure structural continuity; finally, the fireproof expansion seal 8 and the fireproof expansion seal 9 located at the edge of the fire door expand and fill the gaps under the high temperature of the fire, preventing flames and smoke from penetrating. When the most unfavorable working condition is reached, i.e. when a fire occurs, the subway train happens to pass through the section. Door 2 is simultaneously subjected to the high temperature of the fire and the piston wind pressure. Specifically, the high temperature causes a softening effect, reduces the material strength, reduces the structural stiffness and increases the deformation. The expansion stress of the channel steel inner frame 5 is released through the sliding of the T-shaped sliding connection plate 14, but the sliding causes the connection stiffness to decrease. The decrease in stiffness causes the load to concentrate in the non-slip area, and the wind pressure load is redistributed. The elastic tie 13 deforms to absorb part of the wind pressure energy. In addition, it provides support through the fireproof board 11 and the fireproof door core board 10. With the help of the fireproof door core board 10's characteristic of maintaining a certain strength at high temperature, it provides in-plane support to prevent the door leaf 2 from bulging. Eventually approaching equilibrium, most of the thermal stress is released through the sliding connection plate 14, while the wind pressure is supported by the elastic tie member 13, the fireproof board 11, and the fireproof door core plate 10. The fireproof door structure can maintain its integrity for a certain period of time even under the most unfavorable working conditions.

[0030] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A fire door and its multi-layer fire-resistant composite filling structure, comprising a door leaf (2) and an internal frame, characterized in that: The fire-resistant filling structure of the fire door adopts a multi-layer composite structure, which consists of stainless steel door leaf (2), fireproof board (11), fireproof door core board (10), fireproof board (11), and door leaf (2) from the outside to the inside. The fireproof board (11) withstands thermal shock and blocks the transmission of high temperature to the fireproof door core board (10). The fireproof door core board (10) dehydrates and absorbs heat at high temperature, thus delaying the temperature rise. The door leaf (2) and the internal frame are provided with a number of elastic tie members (13) arranged in an array; the elastic tie member (13) is fixedly welded to the internal frame through a welding end (1301) at one end, and the screw end (1302) at the other end is connected to the door leaf (2) by bolts, forming a stress relief gap between the door leaf (2) and the internal frame that allows the thermal expansion displacement of the door leaf (2); The internal frame consists of an inner frame (5) arranged in a crisscross pattern and an outer frame (6) arranged around the edge of the fire door; The two inner skeletons (5) are provided with stress relief grooves at the center of their mating end faces. After splicing, they form a cavity. A T-shaped sliding connecting plate (14) is provided in the cavity. An elongated hole is provided on the transverse flange of the T-shaped sliding connecting plate (14). The plate is connected to the web of the inner skeleton (5) by a bolt passing through the elongated hole.

2. The fire door and its multi-layer fire-resistant composite filling structure according to claim 1, characterized in that: The elastic tie member (13) is made of spring steel sheet, and the threaded end (1302) of the elastic tie member (13) connected to the door leaf (2) has an elongated hole. The elastic tie member (13) is connected to the door leaf (2) by a bolt passing through the elongated hole to provide longitudinal sliding release.

3. The fire door and its multi-layer fire-resistant composite filling structure according to claim 2, characterized in that: The junction between the welded end (1301) and the screwed end (1302) is provided with a polygonal bending section. The polygonal bending section is used to maintain the bending strength of the elastic tie member (13) under normal working conditions, and only produces elastic deformation when the stress on the door leaf (2) is greater than the bending strength. An inclined section is provided between the polygonal bending section and the end of the screw connection (1302). The inclined section serves as the main section where the elastic tie member (13) undergoes elastic deformation under stress, supporting the door leaf (2) to undergo thermal expansion displacement within the stress release gap.

4. The fire door and its multi-layer fire-resistant composite filling structure according to claim 3, characterized in that: The internal skeleton is arranged with 16-25 elastic tie members (13) per square meter, with a spacing of 200-250mm.

5. The fire door and its multi-layer fire-resistant composite filling structure according to claim 4, characterized in that: The stress relief gaps between the internal frame and the front and rear door panels (2) are filled with fireproof boards (11).

6. The fire door and its multi-layer fire-resistant composite filling structure according to claim 1, characterized in that: The length of the elongated hole on the transverse flange of the T-shaped sliding connecting plate (14) is 4-6 mm larger than the diameter of the bolt, which is used to provide longitudinal sliding release.

7. The fire door and its multi-layer fire-resistant composite filling structure according to claim 6, characterized in that: The stress relief groove is a V-shaped groove. The V-shaped grooves of the two inner skeletons (5) are spliced ​​together to form a rhomboid cavity, which is filled with flexible fireproof material.

8. The fire door and its multi-layer fire-resistant composite filling structure according to claim 1, characterized in that: The inner frame (5) serves as a reinforcing frame, and the frames are welded and fixed to form a frame grid structure. The fireproof door core panel (10) is filled inside the frame grid structure. The fireproof board (11) is placed between the door leaf (2) and the fireproof door core board (10) as a transition layer.

9. The fire door and its multi-layer fire-resistant composite filling structure according to claim 1, characterized in that: It also includes a door frame tie rod (7) as a door frame structure and a door frame skeleton (12), and the door frame skeleton (12) is wrapped with a door frame (1) on its surface along the frame laying direction.

10. The fire door and its multi-layer fire-resistant composite filling structure according to claim 9, characterized in that: Fire-resistant expansion seal 1 (8) and fire-resistant expansion seal 2 (9) are provided in the gap between the door leaf (2) and the door frame (1). The fire-resistant expansion seal 1 (8) and fire-resistant expansion seal 2 (9) expand and fill the gap under high temperature in a fire.

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