Disclosure of Invention
The invention aims to provide a flame-retardant heat-insulation color steel plate which has the advantages of good resistance, automatic flame-retardant fire extinguishing, automatic alarm and high safety performance, and solves the problems in the background art.
In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a various steel sheet of fire-retardant type heat preservation, includes two parallel arrangement's outer steel sheet, and is two sets of the front and the back of outer steel sheet distribute spacing and spacing seat of fixedly connected with, the outer wall of outer steel sheet is for buckling the structure, and is two sets of it has fire-retardant filling layer, two sets of to fill between the outer steel sheet fixedly connected with strengthening rib one between the opposite face of outer steel sheet, strengthening rib one is provided with the multiunit and is located two sets of the biggest department of outer steel sheet opposite face interval, strengthening rib one is oval structure.
Preferably, the top fixedly connected with heat transfer casing of outer steel sheet, heat transfer casing right side wall fixed mounting has the alarm, the inner wall bottom fixedly connected with water storage plate of heat transfer casing, water storage plate is hollow structure, the equal fixedly connected with sprinkler bead that carries out the water spray to the outer steel sheet surface of the bottom left and right sides of water storage plate.
Preferably, the top fixed mounting of water storage plate has the fire-retardant mechanism that three equidistance of group were arranged, fire-retardant mechanism includes fire-retardant casing, the inner wall bottom fixedly connected with mounting panel of fire-retardant casing, the front dead axle of mounting panel rotates and is connected with carousel one, the back of mounting panel is equipped with the carousel two that links firmly with a carousel is coaxial, the outer wall of carousel two is provided with four evenly distributed's of group lug.
Preferably, the eccentric position of the front surface of the first rotating disc is fixedly connected with a connecting shaft, the outer wall of the connecting shaft is fixedly connected with a first rotating plate in a rotating mode, one end of the first rotating plate, which is far away from the connecting shaft, is rotatably connected with a reversing plate which is of a V-shaped structure, the middle inflection point position of the reversing plate is rotationally connected with the front fixed shaft of the mounting plate, one end of the reversing plate far away from the first rotating plate is rotationally connected with the first movable plate, the left side wall of the flame-retardant shell is fixedly connected with a heat absorption barrel, the outer wall of the heat absorption barrel penetrates through the inner wall of the heat exchange shell and is exposed outside the heat exchange shell, the inner wall of the heat absorption cylinder is connected with a first piston in a sliding way, the right side wall of the first piston is fixedly connected with a first piston rod, the piston rod penetrates through the outer wall of the flame-retardant shell and extends to the inner cavity of the flame-retardant shell, and one end, far away from the first piston, of the piston rod is movably connected with one end, far away from the reversing plate, of the first movable plate.
Preferably, the back position of the inside of the flame-retardant shell relative to the heat absorption cylinder is fixedly connected with a heat dissipation cylinder, the inner wall of the heat dissipation cylinder is connected with a piston II in a sliding mode, a through hole is formed in the left side wall of the heat dissipation cylinder, a communicating pipe is fixedly connected with the inside of the through hole and penetrates through the outer wall of the flame-retardant shell and extends to the inner cavity of the heat absorption cylinder, the right side wall of the piston II is connected with a piston rod II in a fixed-axis rotating mode, one end, far away from the piston II, of the piston rod II is movably connected with a rotating plate II, and one end, far away from the piston rod II, of the rotating plate II is movably connected with one end, far away from the rotating plate I, of the connecting shaft.
Preferably, the eccentric position of the back surface of the second rotating disc is fixedly connected with a rotating shaft, the bottom of the inner wall of the flame-retardant shell is fixedly connected with a water pumping shell, the lower side of the outer wall of the water pumping shell is provided with a through hole and is fixedly connected with a water suction pipe through the through hole, one end of the water suction pipe, far away from the water pumping shell, is externally connected with a water storage barrel, the inner wall of the water pumping shell is movably connected with a lower valve plate relative to the position of the water suction pipe, the upper side of the outer wall of the water pumping shell is provided with a through hole and is fixedly connected with a water outlet pipe through the through hole, one end of the water outlet pipe, far away from the water pumping shell, is communicated with the inside of the water storage plate, the inner wall of the water pumping shell is slidably connected with a pressing plate, the upper surface of the pressing plate is movably connected with an upper valve plate, the upper surface of the pressing plate is provided with a through hole relative to the lower part of the upper valve plate, the middle position of the upper surface of the pressing plate is fixedly connected with a pressing rod, the top of the pressing rod penetrates through the upper surface of the water pumping shell and is movably connected with a third rotating plate, and one end of the third rotating plate, which is far away from the pressure lever, is movably connected with the outer wall of the rotating shaft.
Preferably, the inner wall bottom fixedly connected with insulating housing of fire-retardant casing, insulating housing's inner wall bottom fixedly connected with socket, the last fixed surface of socket is connected with the spring, the top fixedly connected with and insulating housing inner wall sliding connection's of spring plug, the last fixed surface of plug is connected with the link, insulating housing's upper surface is run through at the top of link, the inner wall top swing joint of link has the gyro wheel that can laminate with the lug surface.
Preferably, a flame-retardant filling layer is filled between the two groups of outer steel plates, a second reinforcing rib is fixedly connected between opposite surfaces of the two groups of outer steel plates, the second reinforcing rib is provided with a plurality of groups and is respectively positioned at the maximum distance between the opposite surfaces of the two groups of outer steel plates, and the second reinforcing rib is of an X-shaped structure.
Compared with the prior art, the invention has the following beneficial effects:
1. the spacing of outer steel sheet outer wall is pegged graft inside the spacing seat of adjacent outer steel sheet, realizes the concatenation of the outer steel sheet of multiunit, through the fire-retardant filling layer that sets up the rock wool material, has that fire behaviour is good, does not melt when meeting fire, and the advantage of poison gas is not released to low smoke, improves the fire-retardant insulation performance of various steel sheet.
2. The phenomenon that the outer steel plate is softened and collapsed is prevented by arranging the reinforcing ribs to support the flame-retardant filling layer and the two sets of outer steel plates.
3. Power is output through the cycle that the cooling, the compression, the heat absorption and the expansion of the gas in the heat absorption cylinder and the heat dissipation cylinder are in one cycle, and the phenomenon that a circuit is burnt out and cannot automatically resist flame under the condition of indoor fire is prevented.
4. The socket can be hammered continuously through the plug to make a sound, mechanical alarm is carried out, and the phenomenon that alarm lines cannot give an alarm after being burnt out is prevented.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The first embodiment is as follows:
as shown in fig. 1 and 4, a various steel sheet of fire-retardant type heat preservation, including two parallel arrangement's outer steel sheet 1, the front and the back of two sets of outer steel sheet 1 distribute fixedly connected with spacing 2 and spacing seat 8, the outer wall of outer steel sheet 1 is the structure of buckling, it has fire-retardant filling layer 9 to fill between two sets of outer steel sheet 1, fixedly connected with strengthening rib one 10 between two sets of outer steel sheet 1's the opposite face, strengthening rib one 10 is provided with the multiunit and is located the biggest department of two sets of outer steel sheet 1 opposite face intervals respectively, strengthening rib one 10 is the oval structure.
The limiting strips 2 on the outer wall of the outer steel plate 1 are inserted into the limiting seats 8 of the adjacent outer steel plates 1 to realize the splicing of a plurality of groups of outer steel plates 1, and the flame-retardant filling layer 9 made of rock wool material has the advantages of good flame-retardant property, no melting in case of fire, low smoke and no toxic gas release, and improves the flame-retardant and heat-insulating properties of the color steel plate;
although the outer steel plates 1 and the flame-retardant filling layer 9 are all noncombustible, when the fire-retardant filling layer 9 burns at high temperature, the surfaces of the outer steel plates 1 are softened, and the middle flame-retardant filling layer 9 has the effects of fire prevention and heat insulation but does not have strength, so that the first reinforcing ribs 10 are arranged to support the flame-retardant filling layer 9 and the two groups of outer steel plates 1 and prevent the outer steel plates 1 from softening and collapsing.
As shown in fig. 1 and 3, the top of the outer steel plate 1 is fixedly connected with a heat exchange shell 3, the right side wall of the heat exchange shell 3 is fixedly provided with an alarm 4, the bottom of the inner wall of the heat exchange shell 3 is fixedly connected with a water storage plate 5, the water storage plate is of a hollow structure, and the left side and the right side of the bottom of the water storage plate 5 are fixedly connected with water spray heads 7 for spraying water on the surface of the outer steel plate 1.
The alarm 4 is electrified to give an audible and visual alarm to outdoor people to remind people of extinguishing fire rapidly, and water flow in the external water storage tank is led into the inner cavity of the water pumping shell 29 through the water suction pipe 30 to replenish water, so that the continuous fire extinguishing function is realized.
As shown in fig. 5, three groups of flame retarding mechanisms 6 arranged at equal intervals are fixedly mounted at the top of the water storage plate 5, each flame retarding mechanism 6 comprises a flame retarding casing 11, a mounting plate 12 is fixedly connected to the bottom of the inner wall of the flame retarding casing 11, a first rotating disc 13 is rotatably connected to the front surface of the mounting plate 12 in a fixed-axis manner, a second rotating disc 14 coaxially and fixedly connected to the first rotating disc 13 is arranged on the back surface of the mounting plate 12, and four groups of lugs 15 are uniformly distributed on the outer wall of the second rotating disc 14.
As shown in fig. 5 and 7, a connecting shaft 16 is fixedly connected to the eccentric position of the front side of the first rotating disk 13, a rotating plate 17 is rotatably connected to the outer wall of the connecting shaft 16 in a fixed-axis manner, a reversing plate 18 is rotatably connected to one end of the rotating plate 17, which is far away from the connecting shaft 16, the reversing plate 18 is of a "V" shaped structure, the middle inflection point position of the reversing plate 18 is rotatably connected to the fixed-axis position of the front side of the mounting plate 12, a movable plate 19 is rotatably connected to one end of the reversing plate 18, which is far away from the rotating plate 17, a heat absorbing barrel 21 is fixedly connected to the left side wall of the flame-retardant housing 11, the outer wall of the heat absorbing cylinder 21 penetrates through the inner wall of the heat exchange shell 3 and is exposed outside the heat exchange shell 3, the inner wall of the heat absorbing cylinder 21 is connected with a first piston 32 in a sliding mode, the right side wall of the first piston 32 is fixedly connected with a first piston rod 20, the first piston rod 20 penetrates through the outer wall of the flame-retardant shell 11 and extends to the inner cavity of the flame-retardant shell 11, and one end, far away from the first piston 32, of the first piston rod 20 is movably connected with one end, far away from the reversing plate 18, of the first movable plate 19.
When the combustion starts in the chamber, a certain amount of open fire is generated, at the moment, the open fire starts to burn the outer wall of the heat absorption cylinder 21, at the moment, the gas in the inner cavity of the heat absorption cylinder 21, which is positioned on the left side of the first piston 32, starts to expand, so that the first piston 32 is pushed to slide rightwards, and at the moment, the gas in the inner cavity of the heat absorption cylinder 21, which is positioned on the right side of the first piston 32, is guided into the inner cavity of the heat dissipation cylinder 24 through the communication pipe 42;
in the initial state as shown in fig. 7, the piston rod one 20 is driven to move rightwards by the piston one 32 sliding rightwards, and then the movable plate one 19 is driven to push the reversing plate 18 to deflect clockwise by taking the middle turning point as the axis, at this time, the right end of the reversing plate 18 starts to move downwards, and then the rotating plate one 17 is pulled to move downwards, and further the rotating plate one 17 and the rotating disc one 13 are driven to rotate anticlockwise by taking the center position of the rotating disc one 13 as the axis, and the state is shown in fig. 8.
As shown in fig. 5 and 11, a heat dissipating cylinder 24 is fixedly connected to the back of the interior of the flame-retardant housing 11 relative to the heat absorbing cylinder 21, a piston two 41 is slidably connected to the inner wall of the heat dissipating cylinder 24, a through hole is formed in the left side wall of the heat dissipating cylinder 24, a communicating pipe 42 is fixedly connected to the interior of the through hole, the communicating pipe 42 penetrates through the outer wall of the flame-retardant housing 11 and extends to the inner cavity of the heat absorbing cylinder 21, a piston rod two 23 is rotatably connected to the right side wall of the piston two 41 in a fixed-axis manner, a rotating plate two 22 is movably connected to one end, away from the piston rod two 41, of the piston rod two 23, and one end, away from the rotating plate one 13, of the rotating plate two 22 and one end, away from the rotating plate one 13, of the connecting shaft 16.
Because the heat-dissipating cylinder 24 is positioned inside the flame-retardant shell 11, the temperature inside the flame-retardant shell 11 is lower than the temperature of indoor combustion, the heat in the hot air entering the inner cavity of the heat-dissipating cylinder 24 is transferred to the inner wall of the flame-retardant shell 11 through the heat-dissipating cylinder 24 and is conducted out through the water storage plate 5, and at the moment, the air inside the heat-dissipating cylinder 24 is cooled and begins to shrink;
at this time, the rotating plate two 22 is driven to synchronously rotate along with the counterclockwise rotation of the connecting shaft 16, so as to drive the rotating plate two 22 to swing, further drive the piston rod two 23 to move left and right, further push the piston two 41 to slide left and right on the inner wall of the heat dissipation cylinder 24, and further introduce the cold air after heat exchange in the inner cavity of the heat dissipation cylinder 24 into the heat absorption cylinder 21 through the communicating pipe 42.
As shown in fig. 6 and 10, a rotating shaft 26 is fixedly connected to the eccentric position of the back surface of the second rotating disk 14, a water pumping housing 29 is fixedly connected to the bottom of the inner wall of the flame retardant housing 11, a through hole is formed in the lower side of the outer wall of the water pumping housing 29, a water suction pipe 30 is fixedly connected to the through hole, a water storage bucket is externally connected to one end of the water suction pipe 30 away from the water pumping housing 29, a lower valve plate 40 is movably connected to the position of the inner wall of the water pumping housing 29 corresponding to the water suction pipe 30, a water outlet pipe 31 is fixedly connected to the upper side of the outer wall of the water pumping housing 29, one end of the water outlet pipe 31 away from the water pumping housing 29 is communicated with the interior of the water storage plate 5, a pressing plate 38 is slidably connected to the inner wall of the water pumping housing 29, an upper valve plate 39 is movably connected to the upper surface of the pressing plate 38, a through hole is formed in the upper surface of the pressing plate 38 corresponding to the lower portion of the upper valve plate 39, and a pressing rod 28 is fixedly connected to the middle position of the upper surface of the pressing plate 38, the top of the pressure lever 28 penetrates through the upper surface of the water pumping shell 29, the top end of the pressure lever is movably connected with a third rotating plate 27, and one end, far away from the pressure lever 28, of the third rotating plate 27 is movably connected with the outer wall of the rotating shaft 26.
The rotating shaft 26 is arranged at the eccentric position of the rotating disc II 14, when the rotating shaft 26 rotates, the top end of the rotating plate III 27 is driven to move up and down, the pressing rod 28 and the pressing plate 38 are driven to slide up and down on the inner wall of the water pumping shell 29, when the pressing plate 38 slides down, water flow in the inner cavity of the water pumping shell 29 below the pressing plate 38 is extruded, then the water flow penetrates through a through hole in the surface of the pressing plate 38 and jacks up the upper valve plate 39, the water flow is guided into the water outlet pipe 31 and is conveyed into the water storage plate 5, the water flow is sprayed out through the water spraying head 7 to cool the surface of the external steel plate 1, fire is extinguished indoors, when the pressing plate 38 moves up, the position of the inner cavity of the water pumping shell 29 relative to the bottom of the pressing plate 38 is in a negative pressure state, the lower valve plate 40 is attracted to deflect and open, and then the water flow in the external water storage tank is introduced into the inner cavity of the water pumping shell 29 through the water suction pipe 30 for water supplement, realizing the continuous fire extinguishing function.
As shown in fig. 6 and 9, an insulating housing 25 is fixedly connected to the bottom of the inner wall of the flame-retardant housing 11, a socket 33 is fixedly connected to the bottom of the inner wall of the insulating housing 25, a spring 34 is fixedly connected to the upper surface of the socket 33, a plug 35 slidably connected to the inner wall of the insulating housing 25 is fixedly connected to the top of the spring 34, a connecting frame 36 is fixedly connected to the upper surface of the plug 35, the top of the connecting frame 36 penetrates through the upper surface of the insulating housing 25, and a roller 37 capable of being attached to the surface of the bump 15 is movably connected to the top of the inner wall of the connecting frame 36.
Because water flows in the inner cavity of the water storage plate 5 all the time, the surface temperature of the water storage plate 5 is lower, and then the hot air in the inner cavity of the heat dissipation cylinder 24 can be subjected to heat exchange, so that the device can continuously output power;
meanwhile, when the second rotary table 14 rotates, the convex blocks 15 on the surface of the second rotary table 14 intermittently press the rollers 37, so that the connecting frame 36 and the plug 35 are driven to slide up and down on the inner wall of the insulating shell 25, the spring 34 is continuously compressed, and when the plug 35 is inserted into the socket 33, the alarm 4 is powered on, so that audible and visual alarm is performed on outdoor people, and people are reminded of extinguishing fire quickly;
and plug 35 can constantly hammer socket 33 and make a sound, carries out mechanical type warning, prevents the unable phenomenon of reporting to the police after alarm 4 circuit burns out.
Example two:
as shown in fig. 12, on the basis of the first embodiment, 10 is replaced by a second reinforcing rib 101, and the specific replacement is as follows: the filling has fire-retardant filling layer 9 between two sets of outer steel sheet 1, fixedly connected with strengthening rib two 101 between two sets of outer steel sheet 1's the opposite face, and strengthening rib two 101 is provided with the multiunit and is located the biggest department of two sets of outer steel sheet 1 opposite face intervals respectively, and strengthening rib two 101 is "X" shape structure.
Although the outer steel plates 1 and the flame-retardant filling layer 9 are all noncombustible, when the fire-retardant filling layer 9 burns at high temperature, the surfaces of the outer steel plates 1 are softened, and the middle flame-retardant filling layer 9 has the fireproof and heat-insulating effects but does not have the strength, so that the reinforcing ribs two 101 are arranged to support the flame-retardant filling layer 9 and the two groups of outer steel plates 1, and the outer steel plates 1 are prevented from being softened and collapsed.
The working principle of the first embodiment of the scheme is as follows: when the flame-retardant heat-insulation color steel plate is used, the limiting strips 2 on the outer wall of the outer steel plate 1 are inserted into the limiting seats 8 of the adjacent outer steel plates 1, so that the splicing of a plurality of groups of outer steel plates 1 is realized, and the flame-retardant filling layer 9 made of rock wool material has the advantages of good flame-retardant performance, no melting in fire, low smoke and no toxic gas release, and the flame-retardant heat-insulation performance of the color steel plate is improved;
although the outer steel plates 1 and the flame-retardant filling layer 9 are noncombustible, when the outer steel plates 1 are burnt at high temperature, the surfaces of the outer steel plates 1 are softened, and the middle flame-retardant filling layer 9 has the fireproof and heat-insulating effects but does not have the strength, so that the first reinforcing ribs 10 are arranged to support the flame-retardant filling layer 9 and the two groups of outer steel plates 1 and prevent the outer steel plates 1 from softening and collapsing;
when the combustion starts in the chamber, a certain amount of open fire is generated, at the moment, the open fire starts to burn the outer wall of the heat absorption cylinder 21, at the moment, the gas in the inner cavity of the heat absorption cylinder 21, which is positioned on the left side of the first piston 32, starts to expand, so that the first piston 32 is pushed to slide rightwards, and at the moment, the gas in the inner cavity of the heat absorption cylinder 21, which is positioned on the right side of the first piston 32, is guided into the inner cavity of the heat dissipation cylinder 24 through the communication pipe 42;
as shown in fig. 7 in an initial state, the piston one 32 slides rightwards to drive the piston rod one 20 to move rightwards, so as to drive the movable plate one 19 to push the reversing plate 18 to deflect clockwise by taking the middle turning point as an axis, at the moment, the right end of the reversing plate 18 starts to move downwards, so as to pull the rotating plate one 17 to move downwards, so as to drive the rotating plate one 17 and the rotating disc one 13 to rotate anticlockwise by taking the center position of the rotating disc one 13 as an axis, and the state is shown in fig. 8;
because the heat-dissipating cylinder 24 is positioned inside the flame-retardant shell 11, the temperature inside the flame-retardant shell 11 is lower than the temperature of indoor combustion, the heat in the hot air entering the inner cavity of the heat-dissipating cylinder 24 is transferred to the inner wall of the flame-retardant shell 11 through the heat-dissipating cylinder 24 and is conducted out through the water storage plate 5, and at the moment, the air inside the heat-dissipating cylinder 24 is cooled and begins to shrink;
at this time, the rotating plate II 22 is driven to synchronously rotate along with the anticlockwise rotation of the connecting shaft 16, so that the rotating plate II 22 is driven to swing, the piston rod II 23 is driven to move left and right, the piston II 41 is pushed to slide left and right on the inner wall of the heat dissipation cylinder 24, and the cold air after heat exchange in the inner cavity of the heat dissipation cylinder 24 is guided into the heat absorption cylinder 21 through the communicating pipe 42;
when the connecting shaft 16 rotates to the position shown in the state of fig. 8, due to the action of the rotational inertia and the gas pressure of the first rotating disc 13, the first piston 32 starts to slide leftwards at the moment, the volume of the gas is minimum at the moment, and as the heat absorbing cylinder 21 continues to be heated, the gas in the heat absorbing cylinder 21 expands after being heated to drive the first piston 32 to move rightwards again, so that the first piston 32 moves leftwards and rightwards circularly, and the first rotating disc 13 is driven to rotate anticlockwise periodically;
the power is output through the cycle of cooling, compressing, absorbing heat and expanding the gas in the heat absorption cylinder 21 and the heat dissipation cylinder 24 into one cycle, so that the phenomenon that the circuit is burnt out and cannot automatically resist flame under the condition of indoor fire is prevented;
the rotating shaft 26 is arranged at the eccentric position of the rotating disc II 14, when the rotating shaft 26 rotates, the top end of the rotating plate III 27 is driven to move up and down, the pressing rod 28 and the pressing plate 38 are driven to slide up and down on the inner wall of the water pumping shell 29, when the pressing plate 38 slides down, water flow in the inner cavity of the water pumping shell 29 below the pressing plate 38 is extruded, then the water flow penetrates through a through hole in the surface of the pressing plate 38 and jacks up the upper valve plate 39, the water flow is guided into the water outlet pipe 31 and is conveyed into the water storage plate 5, the water flow is sprayed out through the water spraying head 7 to cool the surface of the external steel plate 1, fire is extinguished indoors, when the pressing plate 38 moves up, the position of the inner cavity of the water pumping shell 29 relative to the bottom of the pressing plate 38 is in a negative pressure state, the lower valve plate 40 is attracted to deflect and open, and then the water flow in the external water storage tank is introduced into the inner cavity of the water pumping shell 29 through the water suction pipe 30 for water supplement, realizing the continuous fire extinguishing function;
because water flows in the inner cavity of the water storage plate 5 all the time, the surface temperature of the water storage plate 5 is lower, and then the hot air in the inner cavity of the heat dissipation cylinder 24 can be subjected to heat exchange, so that the device can continuously output power;
meanwhile, when the second rotary table 14 rotates, the convex blocks 15 on the surface of the second rotary table 14 intermittently press the rollers 37, so that the connecting frame 36 and the plug 35 are driven to slide up and down on the inner wall of the insulating shell 25, the spring 34 is continuously compressed, and when the plug 35 is inserted into the socket 33, the alarm 4 is powered on, so that audible and visual alarm is performed on outdoor people, and people are reminded of extinguishing fire quickly;
and plug 35 can constantly hammer socket 33 and make a sound, carries out mechanical type warning, prevents the unable phenomenon of reporting to the police after alarm 4 circuit burns out.
The principle of the second embodiment is different from that of the first embodiment in that the first reinforcing rib 10 is replaced by a second reinforcing rib 101, and the working principle of the second embodiment is as follows: although the outer steel plates 1 and the flame-retardant filling layer 9 are all noncombustible, when the fire-retardant filling layer 9 burns at high temperature, the surfaces of the outer steel plates 1 are softened, and the middle flame-retardant filling layer 9 has the fireproof and heat-insulating effects but does not have the strength, so that the reinforcing ribs two 101 are arranged to support the flame-retardant filling layer 9 and the two groups of outer steel plates 1, and the outer steel plates 1 are prevented from being softened and collapsed.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.