Fire-resistant floor hatch

Abstract

To provide a fire-resistant floor hatch that delivers sufficient fire resistance and can flexibly accommodate constraints due to a floor structure at its installation location.SOLUTION: A fire-resistant floor hatch 10 comprises: a receiving frame provided in an opening A of a floor structure 60 of a building; and an opening / closing cover 50 supported at a peripheral portion on an inner peripheral side D2 of a lower receiving frame 30 within the receiving frame, and capable of openably / closably blocking the opening A. The opening / closing cover 50 is constituted using an insulation material 56. The insulation material 56 comprises: an insulation material lower portion 56a positioned on the inner peripheral side D2 of the lower receiving frame 30; and an insulation material upper portion 56b positioned above the insulation material lower portion 56a and protruding toward an outer peripheral side D1 than the insulation material lower portion 56a to cover a gap G between the insulation material lower portion and the lower receiving frame 30. A protruding portion 56c of the insulation material upper portion 56b that protrudes toward the outer peripheral side D1 than the insulation material lower portion 56a is positioned above the peripheral portion of the inner peripheral side D2 of the lower receiving frame 30.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fire-resistant floor hatch that closes an opening in a floor structure of a building in a fire-resistant manner. [Background technology]

[0002] Floor hatches and machine hatches are used to open and close openings in floor structures of buildings and the like, and an invention for a fire-resistant floor hatch is disclosed in Patent Document 1. This floor hatch comprises an upper receiving frame provided on the upper edge of the opening in the floor structure, a lower receiving frame provided on the lower edge of the opening in the floor structure, an outer lid supported by the upper receiving frame to open and close the top of the opening, and an inner lid supported by the lower receiving frame to open and close the bottom of the opening.

[0003] This floor hatch has an inner lid that is provided with insulation to prevent heat from being transmitted to the upper floor (above floor) of the floor structure due to a fire occurring below (below floor). The inner lid is positioned vertically spaced apart from the outer lid supported by the upper support frame. In this floor hatch, the lower support frame includes a lower horizontal portion that supports the inner lid and a vertical portion that extends upward from the outer periphery of the lower horizontal portion. A bolt protrudes upward from the lower horizontal portion to secure the inner lid. The inner lid includes a frame-shaped frame supported by the lower support frame, insulation disposed within the frame, a lower cover disposed at the bottom of the frame to cover the underside of the insulation, and an upper cover disposed at the top of the frame to cover the upper side of the insulation. The inner lid is supported above the lower horizontal portion of the lower support frame. A bolt attached to the lower support frame is inserted into the inner lid, and a nut is fastened to the tip of the bolt to secure the inner lid to the lower support frame. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-158104 Summary of the Invention [Problem to be solved by the invention]

[0005] In the floor hatch of Patent Document 1, no special design has been implemented for the shape of the inner lid. In other words, the entire inner lid is supported by being placed on the lower horizontal portion of the lower receiving frame. Therefore, when using this floor hatch, the thickness of the inner lid increases the thickness of the floor structure, which can be restricted by the floor structure of the installation location. Therefore, a floor hatch structure that can flexibly accommodate restrictions, such as a restriction on the thickness of the floor structure, is desired.

[0006] The present invention has been made in consideration of such problems, and aims to provide a fire-resistant floor hatch that exhibits sufficient fire-resistant functionality and can flexibly adapt to constraints imposed by the floor structure of the installation location. [Means for solving the problem]

[0007] One aspect of the present invention is a receiving frame provided in an opening (A) of a floor structure (60) of a building; A fire-resistant floor hatch (10) comprising: an opening / closing cover (50) made of a heat insulating material (56), supported on the inner peripheral edge of the receiving frame, and capable of closing the opening, The heat insulating material is This fire-resistant floor hatch has a lower insulating material (56a) that is positioned on the inner side of the receiving frame, and an upper insulating material (56b) that is positioned higher than the lower insulating material and protrudes more toward the outer periphery than the lower insulating material, covering the gap between the lower insulating material and the receiving frame.

[0008] When the fire-resistant floor hatch of the above embodiment is installed in an opening in the floor structure, the lower part of the insulation is positioned on the inner periphery of the frame provided in the opening in the floor structure, and the upper part of the insulation covers the gap between the frame provided in the opening in the floor structure and the lower part of the insulation. With this configuration, even if heat generated under the floor structure rises through the gap between the frame provided in the opening in the floor structure and the lower part of the insulation, the upper part of the insulation makes it difficult for the rising heat to be transmitted above the opening cover. Therefore, sufficient fire resistance can be achieved.

[0009] In addition, the upper part of the insulation is disposed above the inner peripheral edge of the receiving frame provided at the opening of the floor structure. Therefore, the overall thickness of the insulation does not increase the thickness of the floor structure, and the floor structure of the installation location can be hardly restricted. Therefore, the fire-resistant floor hatch of the above-mentioned embodiment exhibits sufficient fire resistance and can flexibly accommodate even when there are restrictions due to the floor structure of the installation location.

[0010] Another aspect of the present invention is an upper receiving frame provided at an upper edge of an opening provided in a floor structure of a building; a lower receiving frame provided at a lower edge of the opening; an upper cover supported by the upper receiving frame and configured to open and close the upper portion of the opening; a lower lid that is supported by the lower receiving frame at a position spaced downward from the upper lid and that closes the lower part of the opening in an openable and closable manner; The lower cover is a fire-resistant floor hatch having a heat insulating material inside, The heat insulating material is disposed on the lower cover over a wide area from the inner periphery of the lower receiving frame toward the outer periphery, and a step recessed upward is formed on the periphery of the lower surface of the lower cover, This fire-resistant floor hatch has a step portion of the lower cover supported by the lower receiving frame, so that the inner periphery of the step portion hangs down into the opening.

[0011] In the fire-resistant floor hatch of the above-described alternative embodiment, the lower cover is provided with a wide area of ​​insulating material extending from the inner periphery of the lower support frame to the outer periphery, and a stepped portion recessed upward is formed on the peripheral edge of the lower surface of the lower cover. The lower cover is supported by the lower support frame, and the portion of the lower cover that is inwardly recessed from the stepped portion hangs down into the opening in the floor structure. The lower cover is provided with insulating material both below and above the height of the stepped portion supported by the lower support frame, so that even if the insulating material is thick enough to provide sufficient insulating function, the thickness of the floor structure does not need to be excessively thick due to the fire-resistant floor hatch. This reduces restrictions on the thickness of the floor structure in the building in which this fire-resistant floor hatch is installed. Furthermore, because the lower cover is designed to open and close and close the lower portion of the opening, a small gap is created between the portion of the lower cover that hangs down into the opening on the inner periphery of the stepped portion and the side of the opening. Because the insulation is distributed over a wide area from the inner periphery of the lower receiving frame to the outer periphery, even if heat generated under the floor structure rises through the gap between the part of the lower cover that hangs down into the opening on the inner periphery of the step and the side of the opening, the insulation prevents the rising heat from being transmitted above the lower cover. This means that the fire-resistant floor hatch will have sufficient fire resistance even if there are fewer restrictions on the thickness of the floor structure of the building in which it is installed.

[0012] In one aspect of the present invention, the receiving frame is constructed using an upper receiving frame (20) provided at the upper edge of the opening, a lower receiving frame (30) provided at a position lower than the upper edge, and connecting members (24) that connect the upper receiving frame and the lower receiving frame at multiple points in the circumferential direction (C), and the opening / closing lid is constructed as a lower lid (50) that has the insulating material and is supported by the lower receiving frame, and the fire-resistant floor hatch may further include an upper lid (40) that is supported by the upper receiving frame and closes the opening in an openable and closable manner.

[0013] By dividing the frame into an upper frame and a lower frame, and by partially connecting the upper and lower frames with connecting members, it is possible to mitigate the transfer of heat from the lower frame to the upper frame when heat generated under the floor structure rises. Also, by connecting the upper and lower frames with connecting members, it is easy to install the frame on the floor structure.

[0014] The opening / closing lid is preferably covered with a covering member that covers at least the outer peripheral portion of the insulating material in order to protect the insulating material and to easily place the insulating material in the opening of the floor structure. In particular, the opening / closing lid has a placement member (52) inside which the insulating material is placed and a lid member (51) that covers the insulating material and the placement member from above, and a protruding portion (56c) of the upper part of the insulating material that protrudes outer circumferentially beyond the lower part of the insulating material may be placed above the inner peripheral edge portion of the receiving frame while being surrounded by the placement member and the lid member.

[0015] By using the positioning member and the lid member as the covering member, it becomes easy to position the insulating material inside the covering member and to protect the insulating material. Also, by using the positioning member and the lid member, it becomes easy to surround and protect the protruding portion of the upper part of the insulating material from the bottom, outer periphery, and top. Furthermore, by positioning the protruding portion above the peripheral portion of the inner periphery of the receiving frame while being surrounded by the positioning member and the lid member, the protruding portion can appropriately cover the gap between the lower part of the insulating material and the receiving frame.

[0016] The positioning member may have an outer circumferential positioning portion (54a) that covers the outer circumferential side of the protrusion, a lower circumferential positioning portion (54b) that bends from the lower end of the outer circumferential positioning portion toward the inner circumferential side and covers the lower side of the protrusion, and an upper circumferential positioning portion (53) that bends from the upper end of the outer circumferential positioning portion toward the inner circumferential side or the outer circumferential side and is used to attach the lid member. By having the outer circumferential positioning portion, the lower circumferential positioning portion, and the upper circumferential positioning portion, the protrusion can be protected and the lid member can be attached to the positioning member appropriately.

[0017] The inner peripheral edge of the receiving frame may have an inner peripheral bent portion (34) bent upward. A seal member (35) is disposed on the outer periphery of the inner peripheral bent portion, sandwiched between the inner peripheral bent portion and the lower portion of the arrangement, thereby sealing the gap between the receiving frame and the lower portion of the arrangement. The outer peripheral edge of the cover member may have an outer peripheral bent portion (51a) bent downward. When the cover member is attached to the arrangement member and the cover member is attached to the receiving frame, the amount of compression of the seal member may be determined by the outer peripheral bent portion abutting against the receiving frame. This configuration allows the amount of compression of the seal member to be appropriately set. Using a seal member with an appropriately set amount of compression allows for an appropriate seal between the receiving frame and the protruding portion of the upper part of the insulation material disposed inside the arrangement member and the cover member.

[0018] The insulating material may be composed of a first insulating material (56a) constituting the lower insulating material and a second insulating material (56b) constituting the upper insulating material and laminated on top of the first insulating material, and the outer peripheral portion of the positioning member may have a stepped shape that covers the first insulating material and the second insulating material from the outer peripheral side. By constructing the insulating material from two types of materials, the first insulating material and the second insulating material, it is possible to easily form an insulating material having an upper insulating material and a lower insulating material. Furthermore, by forming a stepped shape in the outer peripheral portion of the positioning member, it is possible to easily position the first insulating material and the second insulating material at appropriate positions on the positioning member.

[0019] In another aspect of the present invention, a sealing member is preferably provided on the lower receiving frame at a position opposite the stepped portion. The lower cover is not supported at two positions spaced apart above and below, but is supported on the lower receiving frame so that the stepped portion on which the insulating material is disposed is pressed against the sealing member of the lower receiving frame. The sealing member then reliably seals the gap between the lower cover and the lower receiving frame. As a result, even if smoke-laden air rises from under the floor structure, the sealing member prevents the smoke-laden air from flowing out onto the floor of the floor structure, and even if water flows into the opening from above the floor structure, the water that has flowed in can be prevented from flowing out below the floor of the floor structure.

[0020] Note that the parenthesized symbols of each component shown in each aspect of the present invention indicate the correspondence with the symbols in the drawings in the embodiment, but do not limit each component to only the contents of the embodiment. [Brief explanation of the drawings]

[0021] [Figure 1] This is a plan view of a fire-resistant floor hatch according to an embodiment, showing two upper covers on the right and two lower covers on the left, with part of the lower receiving frame visible from the upper left of the lower covers. [Figure 2] 2 is a partially enlarged cross-sectional view taken along the line AA of FIG. 1, showing the fire-resistant floor hatch installed on the floor structure according to the embodiment. [Figure 3] 3 is a partially enlarged cross-sectional view of FIG. 2 showing the fire-resistant floor hatch according to the embodiment in a state before installation on the floor structure. [Figure 4] This is an explanatory diagram showing the state in which a fire-resistant floor hatch is being installed according to an embodiment, with the receiving frame installed on the floor structure. [Figure 5] This is an explanatory diagram showing the state in which the fire-resistant floor hatch according to the embodiment is being installed, with the lower cover being assembled. [Figure 6] 4 is a partially enlarged cross-sectional view corresponding to a part of FIG. 3, showing an arrangement member of another configuration according to an embodiment. [Figure 7] A cross-sectional view corresponding to Figure 2, showing a fire-resistant floor hatch in a reference embodiment. [Figure 8] A cross-sectional view corresponding to Figure 2, showing another fire-resistant floor hatch in a reference form. DETAILED DESCRIPTION OF THE INVENTION

[0022] <Embodiment> Hereinafter, one embodiment of a fire-resistant floor hatch (fire-resistant hatch or fire-resistant machine hatch) of the present invention will be described with reference to the drawings. (Overall configuration of the fire-resistant floor hatch 10) As shown in FIGS. 1 to 3 , the fire-resistant floor hatch 10 includes a frame provided at an opening A in a floor structure 60 of a building, and an openable / closable cover 50 supported by a peripheral portion of the frame on the inner circumferential side D2 of a lower frame 30 to openably and closably close the opening A. The openable / closable cover 50 is constructed using a thermal insulating material 56. The thermal insulating material 56 has a lower thermal insulating material portion 56a disposed on the inner circumferential side D2 of the lower frame 30, and an upper thermal insulating material portion 56b positioned above the lower thermal insulating material portion 56a and protruding toward the outer circumferential side D1 more than the lower thermal insulating material portion 56a to cover the gap G between the lower frame 30 and the frame 60. In this embodiment, a protruding portion 56c of the upper thermal insulating material portion 56b protruding toward the outer circumferential side D1 more than the lower thermal insulating material portion 56a is disposed above the peripheral portion of the inner circumferential side D2 of the lower frame 30.

[0023] The receiving frame of this embodiment is composed of an upper receiving frame 20 provided on the upper edge of the opening A of the floor structure 60, a lower receiving frame 30 provided at a position located below the upper edge of the opening A, and connecting members 24 connecting the upper receiving frame 20 and the lower receiving frame 30 at multiple locations in the circumferential direction C. In other words, the receiving frame has a structure connected by multiple connecting members 24 to reduce heat transfer from the lower receiving frame 30 to the upper receiving frame 20. The opening / closing cover 50 of this embodiment is composed as a lower cover 50 that has a heat insulating material 56 and is supported by the lower receiving frame 30. The fire-resistant floor hatch 10 of this embodiment also includes an upper cover 40 that is supported by the upper receiving frame 20 and closes the opening A in an openable and closable manner.

[0024] Here, Fig. 1 shows the upper cover 40, lower cover 50, and lower receiving frame 30 of the fire-resistant floor hatch 10 in a plan view. Fig. 2 shows a cross section of the fire-resistant floor hatch 10 installed on the floor structure 60. Fig. 3 shows a cross section of the fire-resistant floor hatch 10 before it is installed on the floor structure 60. Note that Fig. 2 shows a cross section of the fire-resistant floor hatch 10 in Fig. 1 taken along line AA in the long side direction, but the cross section of the fire-resistant floor hatch 10 in the short side direction is also the same as Fig. 2.

[0025] More specifically, as shown in FIGS. 1 to 3, the fire-resistant floor hatch 10 of this embodiment is attached to the periphery of a large rectangular opening A provided in a floor structure 60 of a building or the like, and closes the opening A in an openable and closable manner. The fire-resistant floor hatch 10 has a double-lid structure consisting of an upper cover 40 and a lower cover 50 having a heat insulating material 56, and is configured to prevent heat from being transmitted to the upper surface of the floor structure 60 due to a fire that has broken out below the floor structure 60. The fire-resistant floor hatch 10 includes an upper receiving frame 20 provided at the upper edge of the opening A of the floor structure 60, a lower receiving frame 30 provided at the lower edge of the opening A, the upper cover 40 supported by the upper receiving frame 20 to openably close the upper part of the opening A, and a lower cover 50 supported by the lower receiving frame 30 at a position spaced downward from the upper cover 40 to openably close the lower part of the opening A.

[0026] (Circumferential direction C, outer circumferential side D1, inner circumferential side D2) In this embodiment, the circumferential direction C refers to a direction around a central axis passing through the opening A of the floor structure 60, and refers to a direction in which the periphery of the opening A of the floor structure 60 is located. The outer peripheral side D1 refers to the outside in a radial direction centered on the central axis passing through the opening A of the floor structure 60, and the inner peripheral side D2 refers to the opposite side to the outer peripheral side D1. The opening A of the floor structure 60 in this embodiment is formed along the vertical direction, and the circumferential direction C and the radial direction are located in the horizontal direction. Note that the central axis passing through the opening A may be inclined with respect to the vertical direction.

[0027] (Uses of the fire-resistant floor hatch 10, etc.) The fire-resistant floor hatch 10 is used to form access points, access points, and inspection hatches for various machines, equipment, etc. in the floor structure 60. The fire-resistant floor hatch 10 of this embodiment is also called a fire-resistant machine hatch. In particular, the fire-resistant machine hatch is used to store large machines used in buildings, vibration isolation devices used in seismically isolated buildings, etc. under the floor. The floor structure 60 may be not only a structure that forms an indoor floor surface, but also a structure that forms an outdoor floor surface.

[0028] (Upper receiving frame 20) As shown in Figures 1 to 3, the upper receiving frame 20 is provided at the upper edge of the opening A of the floor structure 60, and is generally rectangular in plan view and generally cylindrical overall. The upper receiving frame 20 has a generally L-shaped cross section, including a horizontal portion 21 extending horizontally and a vertical portion 22 rising upward from the end of the outer circumferential side D1 of the horizontal portion 21. The horizontal portion 21 and vertical portion 22 of the upper receiving frame 20 form the upper edge of the opening A of the floor structure 60. The upper receiving frame 20 is formed using a metal steel plate. An upper cover 40 is placed on the upper side of the horizontal portion 21 of the upper receiving frame 20, and horizontal movement of the upper cover 40 is restricted by the vertical portion 22. A joint material 23 is provided at the upper end of the vertical portion 22 of the upper receiving frame 20, and the joint material 23 functions as a decorative member that fills the gap between the upper end of the vertical portion 22 of the upper receiving frame 20 and the floor surface of the floor structure 60.

[0029] The upper receiving frame 20 is configured as a frame material that receives the upper lid 40. A cushioning material 25 is arranged on the upper side of the horizontal portion 21 of the upper receiving frame 20. The upper lid 40 is placed on the cushioning material 25 arranged on the horizontal portion 21. In this embodiment, the cushioning material 25 is made of a rubber sheet. The upper surface of the upper lid 40 is arranged at approximately the same height as the floor surface of the floor structure 60, and forms a floor surface on which pedestrians and the like can walk.

[0030] (Lower receiving frame 30) As shown in FIGS. 1 to 3 , the lower receiving frame 30 is provided at the lower edge of the opening A of the floor structure 60. In plan view, the lower receiving frame 30 has a generally rectangular shape smaller than the upper receiving frame 20 and a generally cylindrical shape overall. The lower receiving frame 30 has a horizontal portion 31 extending horizontally, a vertical portion 32 rising upward from the end of the horizontal portion 31 on the outer circumferential side D1, and an upper horizontal portion 33 protruding from the upper end of the vertical portion 32 toward the outer circumferential side D1 in the horizontal direction, and has a generally crank-shaped cross section. The end of the horizontal portion 31 on the inner circumferential side D2 is formed with a rising portion 34 rising lower than the vertical portion 32. In other words, the rising portion 34 is formed as an inner circumferential bent portion 34 bending upward from the horizontal portion 31 at the peripheral portion of the inner circumferential side D2 of the lower receiving frame 30. The lower receiving frame 30 is configured as a frame material that supports the lower cover 50 serving as the opening / closing cover 50. The lower receiving frame 30 is formed using a metal steel plate. The inner peripheral bent portion 34 is formed around the entire edge of the inner peripheral side D2 of the lower receiving frame 30, in other words, on the four sides of a substantially rectangular shape when viewed from above.

[0031] As shown in FIG. 3 , a seal member 35 is provided at the corner between the horizontal portion 31 and the rising portion 34 of the lower receiving frame 30 to seal between the lower receiving frame 30 and the lower cover 50. In other words, the seal member 35 is sandwiched between the lower cover 50 and the inner periphery of the bent portion 34 and disposed on the outer periphery of the lower receiving frame 30. The seal member 35 is made of sponge rubber in this embodiment and primarily functions to prevent water flowing into the opening A from above the floor of the floor structure 60 from flowing below the floor of the floor structure 60 and to prevent smoke-laden air rising from below the floor of the floor structure 60 from flowing from the opening A onto the floor of the floor structure 60. The seal member 35 is not limited to sponge rubber and may be made of rubber of other materials. In this embodiment, the rising portion 34 of the lower receiving frame 30 is disposed on the inner periphery D2 of the seal member 35. Therefore, the rising portion 34 prevents the seal member 35 from being directly exposed to the hot air rising from under the floor of the floor structure, and the effect of the hot air on the seal member 35 is reduced.

[0032] Fixing bolts 36 for fixing the lower cover 50 to the lower receiving frame 30 are provided on the horizontal portion 31 of the lower receiving frame 30. The heads 36a of the fixing bolts 36 are disposed below the horizontal portion 31, and the threaded portions 36b of the fixing bolts 36 protrude above the horizontal portion 31. In this embodiment, the fixing bolts 36 are provided at multiple locations in the circumferential direction C of the lower receiving frame 30 at predetermined intervals.

[0033] Furthermore, the connecting member 24 connecting the upper receiving frame 20 and the lower receiving frame 30 is formed as a connecting plate 24 that connects the upper receiving frame 20 and the lower receiving frame 30. The connecting plates 24 are arranged at a plurality of locations in the circumferential direction C of the upper receiving frame 20 and the lower receiving frame 30 at predetermined intervals. The connecting plate 24 is fixed to the horizontal portion 21 of the upper receiving frame 20 and the upper horizontal portion 33 of the lower receiving frame 30. The connecting plate 24 connects the upper receiving frame 20 and the lower receiving frame 30 while they are spaced apart from each other vertically. The connecting plate 24 is formed using a metal steel plate.

[0034] By dividing the frame into an upper frame 20 and a lower frame 30, which are partially connected by a connecting plate 24, heat transfer from the lower frame 30 to the upper frame 20 can be mitigated when heat generated under the floor structure 60 rises. More specifically, as shown in FIGS. 2 and 4 , the space between the upper frame 20 and the lower frame 30 where the connecting plate 24 is not located is filled with concrete 61 when forming the opening A of the floor structure 60. The thermal conductivity of the concrete 61, which is made of cement, water, aggregate, etc., is lower than the thermal conductivity of the metals that form the upper frame 20, the lower frame 30, and the connecting plate 24. This reduces heat transfer from the lower frame 30 to the upper frame 20, mitigating the rise of heat around the fire-resistant floor hatch 10 of the floor structure 60. Furthermore, since the upper receiving frame 20 and the lower receiving frame 30 are connected by the connecting plate 24, it is easy to install the upper receiving frame 20 on the floor structure 60 when forming the opening A in the floor structure 60.

[0035] 4 shows the state in which a receiving frame consisting of the upper receiving frame 20, the lower receiving frame 30, and the connecting plate 24 is installed on the floor structure 60 when constructing the fire-resistant floor hatch 10. As shown in FIG. 4, the opening A in the floor structure 60 is formed by installing the receiving frame on the floor structure 60 using a positioning jig or the like, and pouring concrete 61 around a formwork 71 placed on the inner periphery D2 of the receiving frame. More specifically, the receiving frame is installed using a positioning jig or the like at a position in the floor structure 60 where the opening A will be formed. At this time, fixing bolts 36 are welded to the horizontal portion 31 of the lower receiving frame 30 in an upwardly extending state, and the connecting plate 24 is fixed to the reinforcing bars protruding upward from the floor structure 60.

[0036] Next, formwork 71 is set on the inner peripheral side D2 of the receiving frame, and concrete 61 is poured around the formwork 71. After that, by separating formwork 71 from the receiving frame and concrete 61, opening A is formed in the floor structure 60 with the receiving frame embedded. In this way, as shown in FIG. 2, concrete 61 is filled in the portion between the upper receiving frame 20 and the lower receiving frame 30 where the connecting plate 24 is not arranged, and opening A in the floor structure 60 is formed with the upper receiving frame 20 positioned vertically apart from the lower receiving frame 30. In the receiving frame formed in this way, heat from the lower receiving frame 30 is less likely to be transferred to the upper receiving frame 20.

[0037] (Top lid 40) As shown in Figures 1 to 3, the upper cover 40 closes the top of the opening A in an openable and closable manner, and is placed on the horizontal portion 21 of the upper receiving frame 20. In this embodiment, the upper cover 40 is divided into four pieces in the left-right direction as shown in Figure 1. In Figure 1, the two upper covers 40 on the left side are represented by two-dot chain lines so that the planar shapes of the lower receiving frame 30 and the lower cover 50 can be seen. The upper cover 40 has a frame 41 that forms a frame-shaped side wall, and a ceiling plate 42 provided above the frame 41. The ceiling plate 42 in this embodiment is made of high-strength checkered steel plate.

[0038] (Lower lid 50) As shown in Figures 1 to 3, the lower cover 50 as the opening / closing cover 50 opens and closes a position below the position of the upper cover 40 in the opening A of the floor structure 60, and is placed on the lower receiving frame 30 at a position spaced downward from the upper cover 40. The lower cover 50 has a heat insulating material 56 inside, which makes it difficult for heat from the fire to be transmitted to the top of the floor of the floor structure 60 when a fire breaks out below the floor of the floor structure 60.

[0039] In addition to the insulating material 56, the lower cover 50 includes a positioning member 52 in which the insulating material 56 is disposed, a cover member 51 that covers the insulating material 56 and the positioning member 52 from above, and a bottom plate 57 that covers the insulating material 56 from below. The positioning member 52 is formed in a frame shape that covers the stepped insulating material 56 formed by a lower insulating material portion 56a and an upper insulating material portion 56b from the outer peripheral side D1. The horizontal outer shape of the cover member 51 is larger than the horizontal outer shapes of the positioning member 52 and the insulating material 56. The protruding portion 56c of the upper insulating material portion 56b is disposed above the peripheral portion of the inner peripheral side D2 of the lower receiving frame 30, surrounded by the positioning member 52 and the cover member 51. The positioning member 52 in this embodiment is formed in a shape that opens at the top and bottom. The bottom plate 57 is disposed at the bottom of the positioning member 52, and the cover member 51 is disposed at the top of the positioning member 52. The heat insulating material 56 is housed inside the lower cover 50 by the arrangement member 52 , the cover member 51 and the bottom plate 57 .

[0040] In other words, the lower lid 50 has a lower lid main body 51 as the lid member 51, a frame body 52 as the positioning member 52, a heat insulating material 56 arranged on the inner peripheral side D2 of the frame body 52, and a bottom plate 57. The lower lid main body 51 constitutes a ceiling plate and is formed using a metal steel plate. The frame body 52 is fixed to the lower surface of the lower lid main body 51 and is also formed using a metal steel plate. The bottom plate 57 covers the heat insulating material 56 from below and is also formed using a metal steel plate.

[0041] The lower cover body 51 of the lower cover 50, like the lower receiving frame 30, has a substantially rectangular shape in a plan view. The horizontal outer shape of the lower cover body 51 is larger than the horizontal outer shapes of the opening A of the floor structure 60 and the edge of the inner peripheral side D2 of the lower receiving frame 30. A bent portion 51a bent downward is formed on the peripheral edge of the outer peripheral side D1 of the lower cover body 51. In other words, the bent portion 51a as the outer peripheral bent portion 51a that bends downward from the lower cover body 51 is formed on the peripheral portion of the outer peripheral side D1 of the lower cover body 51 serving as the cover member 51. The bent portion 51a is a portion that abuts against the lower receiving frame 30 and is used when the lower cover 50 is attached to the lower receiving frame 30. The bent portion 51a of the lower cover body 51 is formed around the entire periphery of the end of the outer peripheral side D1 of the lower cover body 51, in other words, on the four sides of the substantially rectangular shape in a plan view.

[0042] 3, bolt insertion holes 51b are formed in the peripheral edge of the outer circumferential side D1 of the lower cover main body 51, and fixing bolts 36 protruding from the horizontal portion 31 of the lower receiving frame 30 are inserted into the bolt insertion holes 51b. When the fixing bolts 36 arranged above the lower receiving frame 30 are inserted into the bolt insertion holes 51b of the lower cover main body 51 and the nuts 37 are tightened on the fixing bolts 36, the bent portions 51a come into contact with the lower receiving frame 30, and the lower cover 50 is fixed to the lower receiving frame 30.

[0043] The positioning member 52 has an outer peripheral portion 54a that covers the outer peripheral side D1 of the protruding portion 56c of the upper insulating material 56b, a lower portion 54b that bends from the lower end of the outer peripheral portion 54a to the inner peripheral side D2 and covers the underside of the protruding portion 56c, an upper portion 53 that bends from the upper end of the outer peripheral portion 54a to the inner peripheral side D2 and covers the upper side of the protruding portion 56c, and lower portion 54c, 55 that extend downward from the end of the inner peripheral side D2 of the lower portion 54b and cover the end of the outer peripheral side D1 of the lower insulating material 56a. The lower portion 54c, 55 is formed by bending the lower outer peripheral portion 54c that covers the outer peripheral side D1 of the lower insulating material 56a and the bottom portion 55 that covers the underside of the end of the outer peripheral side D1 of the lower insulating material 56a. The cover member 51 is attached to the positioning member 52 using the upper portion 53. The outer circumferential arrangement portion 54a, the lower arrangement portion 54b, the upper arrangement portion 53, and the lower arrangement portions 54c and 55 are formed around the entire periphery of the end of the outer circumferential side D1 of the arrangement member 52, in other words, on the four sides of a substantially rectangle in a plan view. An accommodating recess 54d surrounded by the outer circumferential arrangement portion 54a, the lower arrangement portion 54b, and the upper arrangement portion 53 is formed at the end of the outer circumferential side D1 of the arrangement member 52. The protruding portion 56c of the upper insulation material 56b is accommodated in the accommodating recess 54d. Because the arrangement member 52 has the outer circumferential arrangement portion 54a, the lower arrangement portion 54b, and the upper arrangement portion 53, the protruding portion 56c can be protected and the cover member 51 can be attached to the arrangement member 52 appropriately.

[0044] The arrangement member 52 will be described in more detail below. The arrangement member 52, which is a frame body 52, has a generally cylindrical shape and is configured to interpose a heat insulating material 56 inside the lower cover 50. The frame body 52 includes a fixed portion 53 serving as an upper arrangement portion 53 fixed to the peripheral edge of the lower surface of the lower cover main body 51, a side portion 54 formed downward from the end of the outer peripheral side D1 of the fixed portion 53 and constituting an outer arrangement portion 54a, a lower arrangement portion 54b, and a lower outer arrangement portion 54c, and a bottom portion 55 extending from the lower end of the side portion 54 to the inner peripheral side D2 and supporting the bottom plate 57. The side portion 54 includes a first vertical portion 54a extending downward from the end of the outer peripheral side D1 of the arrangement portion 53, a step portion 54b extending from the lower end of the first vertical portion 54a to the inner peripheral side D2, and a second vertical portion 54c extending downward from the end of the step portion 54b on the inner peripheral side D2. The first vertical portion 54a is positioned on the outer peripheral side D1 of the rising portion 34 of the lower receiving frame 30, the second vertical portion 54c is positioned on the inner peripheral side D2 of the rising portion 34, and the step portion 54b is positioned so as to straddle the rising portion 34 between the inner peripheral side D2 and the outer peripheral side D1.

[0045] The sealing member 35, which is disposed on the outer peripheral side D1 of the rising portion 34 serving as the inner peripheral bent portion 34 of the lower receiving frame 30, is disposed in a position where it will come into contact with the step portion 54b of the frame body 52 when the lower cover 50 is placed on the lower receiving frame 30. When the lower cover 50 is placed on the lower receiving frame 30, the sealing member 35 is pressed against the horizontal portion 31 of the lower receiving frame 30 by the step portion 54b, and is brought into close contact with the lower cover 50 and the lower receiving frame 30, thereby sealing the gap between the lower cover 50 and the lower receiving frame 30.

[0046] The lid member 51 is assembled to the arrangement member 52 using a fastener 58 provided on the arrangement upper portion 53 of the arrangement member 52. The fastener 58 used when assembling the arrangement member 52 and the lid member 51 is provided on the arrangement upper portion 53 of the arrangement member 52. In this embodiment, the fastener 58 is configured as a weld nut 58 welded to the arrangement upper portion 53. A through hole 51c used for fastening by the fastener 58 is formed in the portion of the lid member 51 facing the arrangement upper portion 53. In this embodiment, the lid member 51 is assembled to the arrangement member 52 by fastening a screw 58a inserted into the through hole 51c of the lid member 51 to the weld nut 58 provided on the arrangement upper portion 53. Note that the fastener 58 may be a screw welded to the arrangement upper portion 53, and the lid member 51 may be assembled to the arrangement member 52 by fastening a nut to the screw inserted into the through hole 51c of the lid member 51.

[0047] The cover member 51, the positioning member 52, and the bottom plate 57 function as covering members to protect the insulating material 56 and facilitate placement of the insulating material 56 in the opening A of the floor structure 60. The cover member 51, the positioning member 52, and the bottom plate 57 are formed of metal steel plates. The insulating material 56 can be formed using a material that is easily deformed by being placed inside the cover member 51, the positioning member 52, and the bottom plate 57. The use of the positioning member 52 and the cover member 51 makes it easy to surround and protect the protruding portion 56c of the insulating material upper portion 56b from the bottom, outer periphery, and top. Furthermore, the protruding portion 56c of the insulating material upper portion 56b is positioned above the peripheral portion of the inner periphery D2 of the lower receiving frame 30 while surrounded by the positioning member 52 and the cover member 51, so that the protruding portion 56c can adequately cover the gap between the insulating material lower portion 56a and the lower receiving frame 56c.

[0048] (Insulation 56) 2 and 3, the heat insulating material 56 arranged in the lower cover 50 is made up of various types of heat insulating wool. Examples of heat insulating wool include AES (alkaline earth silicate wool). A bottom plate 57 is provided on the bottom 55 inside the frame 52 of the lower cover 50, and the bottom plate 57 has the function of preventing the heat insulating material 56 from being exposed below the floor of the floor structure 60 at the bottom 55 inside the frame 52. The heat insulating material 56 is arranged in the frame 52 except for the upper portion.

[0049] The heat insulating material 56 of this embodiment is composed of a first heat insulating material 56a constituting a lower heat insulating material portion 56a and a second heat insulating material 56b as an upper heat insulating material portion 56b laminated on the upper side of the first heat insulating material 56a. The protruding portion 56c of the upper heat insulating material portion 56b is formed by an end portion of the second heat insulating material 56b on the outer peripheral side D1, which protrudes from the end portion of the first heat insulating material 56a on the outer peripheral side D1 toward the outer peripheral side D1. The thickness of the second heat insulating material 56b is smaller than that of the first heat insulating material 56a. More specifically, the thickness of the first heat insulating material 56a is 50 to 80 mm, and the thickness of the second heat insulating material 56b is 20 to 30 mm. By constructing the heat insulating material 56 from two types of materials, the first heat insulating material 56a and the second heat insulating material 56b, the heat insulating material 56 having the upper heat insulating material portion 56b and the lower heat insulating material portion 56a can be easily formed.

[0050] The first insulating material 56a has a thickness that makes it difficult for heat from flames of a fire that occurs mainly under the floor structure 60 to be transmitted onto the floor of the floor structure 60. The second insulating material 56b has a thickness that makes it difficult for hot air from a fire that occurs under the floor structure 60 to be transmitted to the lower cover main body 51 when the hot air rises through the gap G between the second vertical portion 54c of the frame body 52 and the side surface of the inner periphery D2 of the opening A and the side surface of the inner periphery D2 of the lower receiving frame 30. The thicknesses of the first insulating material 56a and the second insulating material 56b are not limited to the above-mentioned thicknesses and may be changed as appropriate depending on the required insulation performance.

[0051] The portion of the outer peripheral side D1 of the frame 52 serving as the arrangement member 52 has a stepped shape that covers the first insulating material 56a and the second insulating material 56b from the outer peripheral side D1. This stepped shape is formed by an outer peripheral arrangement portion 54a (first vertical portion 54a), a lower arrangement portion 54b (step portion 54b), and a lower outer peripheral arrangement portion 54c (second vertical portion 54c). The stepped shape of the frame 52 makes it possible to appropriately set the arrangement locations of the first insulating material 56a and the second insulating material 56b relative to the frame 52 and to appropriately maintain the shapes of the first insulating material 56a and the second insulating material 56b.

[0052] A protruding portion 56c as an end portion of the outer peripheral side D1 of the second insulating material 56b is disposed within an accommodating recess 54d surrounded by an outer peripheral arrangement portion 54a, a lower arrangement portion 54b, and an upper arrangement portion 53 of the frame body 52 as the arrangement member 52. The second insulating material 56b may be disposed within the frame body 52 while being elastically deformed.

[0053] (Insulation of other configurations 56) The heat insulating material 56 does not necessarily have to be made of two types of material, and for example, the lower heat insulating material portion 56a and the upper heat insulating material portion 56b may be formed by cutting out a portion of the outer circumferential side D1 excluding the protruding portion 56c. In addition, the lower heat insulating material portion 56a and the upper heat insulating material portion 56b may be formed by deforming a portion of the outer circumferential side D1 excluding the protruding portion 56c, as the case may be.

[0054] (Assembly and installation of the lower cover 50) The lower cover 50 is assembled as follows. As shown in FIG. 5 , a bottom plate 57 is placed on the bottom 55 of the frame 52 serving as the arrangement member 52, and a first insulating material 56a is placed on the bottom plate 57 within the frame 52. Next, a second insulating material 56b is placed on the first insulating material 56a. At this time, the end of the outer peripheral side D1 of the second insulating material 56b is elastically deformed and placed in the accommodation recess 54d surrounded by the outer peripheral arrangement portion 54a, the lower arrangement portion 54b, and the upper arrangement portion 53. Next, the cover member 51 is fitted to the arrangement member 52 on which the first insulating material 56a and the second insulating material 56b are placed. Next, a screw 58a inserted through a through hole 51c in the lower cover main body 51 serving as the cover member 51 is tightened into a weld nut 58 on the upper arrangement portion 53 of the frame 52, thereby assembling the frame 52 and the lower cover main body 51, and the lower cover 50 is formed.

[0055] Next, as shown in FIG. 2, the lower cover 50 is attached to the lower receiving frame 30 arranged in the opening A of the floor structure 60. At this time, the fixing bolt 36 extending upward from the horizontal portion 31 of the lower receiving frame 30 is inserted into the bolt insertion hole 51b of the lower cover main body 51 of the lower cover 50. When the nut 37 is tightened around the fixing bolt 36, the sealing member 35 arranged on the outer peripheral side D1 of the inner peripheral bent portion 34 of the lower receiving frame 30 is crushed, and the bent portion 51a as the outer peripheral bent portion 51a of the lower cover main body 51 abuts against the lower receiving frame 30, thereby attaching the lower cover 50 to the lower receiving frame 30. The configuration in which the bent portion 51a abuts against the lower receiving frame 30 allows the amount of crushing of the sealing member 35 to be appropriately set. By using a sealing member 35 with an appropriate crushing amount set, the space between the protrusion 56c located inside the outer periphery 54a and lower part 54b of the placement member 52 and the lower receiving frame 30 can be properly sealed.

[0056] In this manner, when the bottom cover body 51 is attached to the frame 52 and the lower cover body 51 is attached to the lower receiving frame 30, the amount of squeezing of the seal member 35 is determined by the bent portion 51a abutting against the lower receiving frame 30. By appropriately setting the height dimension of the bent portion 51a, the amount of squeezing of the seal member 35 can be appropriately controlled. In this embodiment, when the bottom cover body 51 is attached to the frame 52 and the lower receiving frame 30, a slight gap is formed between the raised portion 34 serving as the inner circumferential bent portion 34 of the lower receiving frame 30 and the stepped portion 54b serving as the lower portion 54b of the frame 52. Alternatively, when the bottom cover body 51 is attached to the frame 52 and the lower receiving frame 30, the raised portion 34 and the stepped portion 54b may be in almost contact with each other.

[0057] (Arrangement member 52 of another configuration) The portion where the positioning member 52 and the cover member 51 are assembled may have the following configuration. Specifically, as shown in Fig. 6, the upper positioning portion 53 of the positioning member 52 may be formed by bending from the upper end of the outer peripheral positioning portion 54a toward the outer peripheral side D1, and the fasteners 58 of the upper positioning portion 53 may be provided at positions that avoid interference with the fixing bolts 36 in the circumferential direction C of the positioning member 52. This configuration makes it easy to position the upper heat insulating material 56b (second heat insulating material 56b) within the frame body 52. ​​Furthermore, it is possible to reduce the space occupied by the fasteners 58 within the frame body 52, and it is possible to reduce the space formed above the upper heat insulating material 56b.

[0058] The upper arrangement portion 53 of the arrangement member 52 having another configuration may be formed partially at a location where the fastener 58 is provided in the circumferential direction C of the arrangement member 52, or may be formed along the circumferential direction C of the arrangement member 52. When the upper arrangement portion 53 is formed along the circumferential direction C of the arrangement member 52, it is sufficient to provide an insertion hole in the upper arrangement portion 53 for inserting the fixing bolt 36 therethrough.

[0059] (Other configurations of the fire-resistant floor hatch 10) The receiving frame may be formed integrally with the upper receiving frame 20 and the lower receiving frame 30. In this case, instead of using the connecting member 24 (connecting plate 24), a plurality of holes or the like may be formed in the intermediate portion between the upper and lower parts of the receiving frame to reduce heat transfer from below to above.

[0060] (Action and effect) When the fire-resistant floor hatch 10 of this embodiment is installed in the opening A of the floor structure 60, the lower insulating material portion 56a of the insulating material 56 is disposed on the inner peripheral side D2 of the lower receiving frame 30 provided in the opening A of the floor structure 60, and the protruding portion 56c of the upper insulating material portion 56b of the insulating material 56 covers from above the gap G between the inner peripheral side D2 of the opening A and the lower receiving frame 30 and the outer peripheral side D1 of the positioning member 52 in which the lower insulating material portion 56a is disposed. With this configuration, even if heat generated under the floor structure 60 rises from the gap G between the inner peripheral side D2 of the opening A and the lower receiving frame 30 of the floor structure 60 and the outer peripheral side D1 of the positioning member 52, the positioning member 52 in which the protruding portion 56c of the upper insulating material portion 56b is disposed makes it difficult for the rising heat to be transmitted above the lower cover 50. Therefore, sufficient fire resistance can be achieved.

[0061] Furthermore, a protruding portion 56c of the upper portion 56b of the insulating material as part of the insulating material 56 is disposed above the peripheral portion of the inner circumferential side D2 of the lower receiving frame 30 provided in the opening A of the floor structure 60. Therefore, the overall thickness of the insulating material 56 does not increase the thickness of the floor structure 60, and it is possible to hardly be restricted by the floor structure 60 where it is installed. Therefore, the fire-resistant floor hatch 10 of this embodiment exhibits sufficient fire resistance and can flexibly accommodate restrictions imposed by the floor structure 60 where it is installed.

[0062] The following describes in more detail the effects of the fire-resistant floor hatch 10 of this embodiment. In the fire-resistant floor hatch 10 of this embodiment, the heat insulating material 56 arranged inside the lower cover 50 prevents the heat from being transmitted to the floor of the floor structure 60 when a fire breaks out below the floor structure 60. In this fire-resistant floor hatch 10, the heat insulating material 56 is arranged within the frame 52 of the lower cover 50 over a wide area from the peripheral edge of the inner periphery side D2 of the horizontal portion 31 of the lower receiving frame 30 to the outer periphery side D1, and a step 54b recessed upward is formed on the peripheral edge of the outer periphery side D1 of the underside of the frame 52 of the lower cover 50, and a portion located below the step 54b on the inner periphery side D2 hangs down into the opening A.

[0063] In the lower cover 50, insulation material 56 is disposed both below and above the height position of the step portion 54b of the frame body 52 supported by the lower receiving frame 30, and even if the insulation material 56 is thick enough to provide sufficient insulation function, there is no need to make the thickness of the floor structure 60 excessively thick due to the fire-resistant floor hatch 10. This reduces restrictions on the thickness of the floor structure 60 of the building in which this fire-resistant floor hatch 10 is installed. In addition, because the lower cover 50 is configured to openably and closably close the lower part of the opening A of the floor structure 60, a small gap G is created between the second vertical portion 54c located on the inner periphery D2 of the step portion 54b of the lower cover 50 and the side surface of the opening A. Since the heat insulating material 56 is disposed over a wide range on the outer peripheral side D1 from the rising portion 34 at the end of the inner peripheral side D2 of the horizontal portion 31 of the lower receiving frame 30, even if heat generated under the floor of the floor structure 60 rises from the gap G between the second vertical portion 54c of the frame body 52 of the lower cover 50 and the side surface of the opening A, the heat insulating material 56 at the position of the step portion 54b makes it difficult for the rising heat to be transmitted above the lower cover 50. As a result, the fire-resistant floor hatch 10 will have sufficient fire resistance even if there are fewer restrictions on the thickness of the floor structure 60 of the building in which the fire-resistant floor hatch 10 is installed.

[0064] Furthermore, in the fire-resistant floor hatch 10 of this embodiment, the lower receiving frame 30 is provided with a seal member 35 at a position facing the step portion 54b of the lower cover 50. The lower cover 50 is not supported at multiple positions spaced apart vertically, but is supported on the lower receiving frame 30 so that the step portion 54b of the frame body 52, on which the heat insulating material 56 is arranged, is pressed against the seal member 35 of the lower receiving frame 30, thereby ensuring a seal against the lower receiving frame 30 by the seal member 35. As a result, even if smoke-laden air rises from below the floor structure 60, the seal member 35 prevents the smoke-laden air from flowing out onto the floor of the floor structure 60, and even if water flows into the opening A from above the floor structure 60, the flowing water can be prevented from flowing out below the floor of the floor structure 60. In this embodiment, the rising portion 34 of the lower receiving frame 30 is provided on the inner peripheral side D2 of the sealing member 35, so that the sealing member 35 is not directly exposed to the hot air rising from under the floor of the floor structure, and heat is indirectly transmitted to the sealing member 35 via the rising portion 34. This reduces the impact of the hot air rising from under the floor of the floor structure on the sealing member 35. Furthermore, the lower cover 50 is not supported at multiple positions spaced apart vertically, and only the step portion 54b of the frame body 52, on which the heat insulating material 56 is disposed, is supported by the lower receiving frame 30. As a result, even if the lower cover 50 is provided with sufficient fire resistance and waterproofing, a large area for arranging the upper receiving frame 20 and the lower receiving frame 30 is not required around the periphery of the opening A of the floor structure 60, as in the fire-resistant floor hatch 200 shown in FIG. 8, which will be described later.

[0065] (Reference form) 7 shows a reference form of a fire-resistant floor hatch 100 having a fire-resistant function. This fire-resistant floor hatch 100 includes an upper receiving frame 110 provided at the upper edge of the opening A of the floor structure 60, a lower receiving frame 120 provided at the lower edge of the opening A of the floor structure 60, an upper lid (outer lid) 130 supported by the upper receiving frame 110 and closing the upper part of the opening A in an openable and closable manner, and a lower lid (inner lid) 140 supported by the lower receiving frame 120 and closing the lower part of the opening A in an openable and closable manner.

[0066] The lower cover (intermediate cover) 140 of the fire-resistant floor hatch 100 shown in Figure 7 includes a lower cover body 141 larger in shape than the lower receiving frame 120, a roughly cylindrical frame body 142 attached to the underside of the lower cover body 141, a heat insulating material 143 disposed within the frame body 142, and a bottom plate 144 disposed below the heat insulating material 143 in the lower part of the frame body 142. The frame body 142 includes a fixing portion 142a fixed to the peripheral part of the lower surface of the lower cover body 141, a vertical frame portion 142b extending downward from the outer end of the fixing portion 142a and fitted into the opening A of the floor structure 60, and a support portion 142c extending inward from the lower part of the vertical frame portion 142b and supporting the bottom plate 144.

[0067] The lower cover body 141 of the lower cover 140 is supported by the lower receiving frame 120 at the lower edge of the opening A, and the frame body 142, inside which the insulating material 143 is arranged, hangs down from the underside of the lower cover body 141 into the opening A of the floor structure 60. Therefore, compared to a structure in which an intermediate cover (lower cover) with the insulating material 143 arranged inside is placed on top of the lower receiving frame and supported, there is no need to separate the lower receiving frame 120 below the upper receiving frame 110 by more than the thickness of the insulating material 143, and this fire-resistant floor hatch 100 can be installed in buildings where the floor structure 60 is not thick (high).

[0068] However, because the lower cover 140 is supported by the lower receiving frame 120 of the opening A of the floor structure 60 so as to be able to open and close, a small gap G is formed between the frame 142 of the lower cover 140 and the side surface of the opening A of the floor structure 60. When a fire breaks out under the floor structure 60, hot air from the fire rises through the gap G formed between the frame 142 of the lower cover 140 and the side surface of the opening A of the floor structure 60. The hot air rising through the gap G between the frame 142 of the lower cover 140 and the side surface of the opening A of the floor structure 60 heats the lower cover body 141 of the lower cover 140, which is not provided with the insulating material 143. Therefore, there is a risk that the hot air that has heated the lower cover body 141 will be transmitted to above the floor of the floor structure 60, and there is room for improvement in order for this fire-resistant floor hatch 100 to exhibit sufficient fire-resistant functionality.

[0069] 8 shows a reference form of a fire-resistant floor hatch 200 having a fire-resistant function. This fire-resistant floor hatch 200 includes an upper receiving frame 210 provided at the upper edge of the opening A of the floor structure 60, a lower receiving frame 220 provided at the lower edge of the opening A of the floor structure 60, an upper lid (outer lid) 230 supported by the upper receiving frame 210 and closing the upper part of the opening A in an openable and closable manner, and a lower lid (inner lid) 240 supported by the upper receiving frame 210 and the lower receiving frame 220 and closing the lower part of the opening A in an openable and closable manner.

[0070] The upper receiving frame 210 of the fire-resistant floor hatch 200 shown in Figure 8 includes an upper lid placing portion 211 on which the upper lid 230 is placed, and a lower lid support portion 212 that is disposed below the upper lid placing portion 211 and supports a lower lid main body 241 that constitutes the upper part of the lower lid 240. The lower receiving frame 220 is disposed below the upper receiving frame 210 and supports the lower part of the lower lid 240. The lower lid (intermediate lid) 240 includes a lower lid main body 241 having a bent portion 241a bent downward at the outer peripheral edge portion, a substantially cylindrical frame body 242 attached to the lower side of the lower lid main body 241, a heat insulating material 243 disposed within the frame body 242, and a bottom plate 244 disposed below the heat insulating material 243 at the lower part of the frame body 242. The frame body 242 includes a fixing portion 242a fixed to the peripheral edge of the lower surface of the lower lid main body 241, a vertical frame portion 242b extending downward from the outer peripheral end of the fixing portion 242a and fitted into the opening A of the floor structure 60, and a support portion 242c extending inward from the lower part of the vertical frame portion 242b and supporting the bottom plate 244. In addition, a seal member 213 is provided on the lower lid support portion 212 of the upper receiving frame 210 at a position facing the lower surface of the lower lid main body 241, and the seal member 213 prevents water that has entered the opening A from above the floor of the floor structure 60 from flowing out below the floor of the floor structure 60.

[0071] Because the lower part of the lower cover 240 is supported by the lower receiving frame 220, the lower part of the gap formed between the frame body 242 of the lower cover 240 and the side surface of the opening A of the floor structure 60 is blocked by the frame body 242 of the lower cover 240 being in close contact with the lower receiving frame 220. For this reason, like the fire-resistant floor hatch 100 shown in FIG. 7, hot air caused by a fire occurring under the floor structure 60 is unlikely to rise up through the gap between the frame body 242 of the lower cover 240 and the side surface of the opening A of the floor structure 60. However, the upper cover 230 is supported by the upper cover placing portion 211 of the upper receiving frame 210, the upper part of the lower cover 240 is supported by the lower cover support portion 212 on the inner circumferential side of the upper cover placing portion 211 of the upper receiving frame 210, and further, the lower part of the lower cover 240 is supported by the lower receiving frame 220 on the inner circumferential side of the lower cover support portion 212 of the upper receiving frame 210. The upper cover 230 and the lower cover 240 are supported at three different points in the vertical direction on the periphery of the opening A of the floor structure 60. For this reason, a large area is required on the periphery of the opening A of the floor structure 60 to arrange the upper receiving frame 210 and the lower receiving frame 220, and installing this fire-resistant floor hatch 200 places restrictions on the area around the opening A of the floor structure 60 of the building.

[0072] Furthermore, the upper part of the lower lid 240 is supported by the lower lid support part 212 of the upper receiving frame 210, and the lower part of the lower lid 240 is placed on and supported by the lower receiving frame 220, but it is not easy to support the lower lid 240 with high precision on both the lower lid support part 212 of the upper receiving frame 210 and the lower receiving frame 220. If a state were to occur in which the upper part of the lower lid 240 is supported by the lower lid support part 212 but the lower part of the lower lid 240 is not placed on the lower receiving frame 220, a gap could be created between the lower part of the lower lid 240 and the lower receiving frame 220.

[0073] On the other hand, if the lower part of the lower cover 240 is placed on the lower receiving frame 220 and the lower cover main body 241 constituting the upper part of the lower cover 240 is not in a state of sufficiently pressing the sealing member 213, there is a risk that the gap between the lower cover main body 241 of the lower cover 240 and the lower cover support part 212 of the upper receiving frame 210 will not be sealed by the sealing member 213. As such, in the fire-resistant floor hatch 200 shown in Figure 8, not only is a wide area required to arrange the upper receiving frame 210 and the lower receiving frame 220 around the periphery of the opening A of the floor structure 60, but it is not easy to support the lower cover 240 accurately on the upper receiving frame 210 and the lower receiving frame 220.

[0074] The present invention is not limited to the embodiments, and further different embodiments can be configured within the scope of the gist of the present invention. The present invention also includes various modifications, modifications within the scope of equivalents, etc. Furthermore, various combinations of components, forms, etc. envisioned from the present invention are also included in the technical spirit of the present invention. [Explanation of symbols]

[0075] 10 Fire-resistant floor hatch 20 Upper receiving frame 21 Horizontal section 22 Vertical section 23 Joint sealant 24 Connecting member (connecting plate) 25 Cushioning material 30 Lower receiving frame 31 Horizontal section 32 Vertical section 33 Upper horizontal part 34 Inner bend (rising part) 35 Sealing material 36 Fixing bolt 36a head 36b Threaded part 37 Nut 40 Top lid 41 frames 42 Ceiling Panel 50 Opening / closing lid (lower lid) 51 Lid member (lower lid body) 51a Outer periphery bending part (bending part) 51b Bolt insertion hole 51c through hole 52 Placement member (frame) 53 Placement upper part (fixed part) 54 Side part 54a Outer periphery (first vertical section) 54b Lower part of arrangement (stepped part) 54c Lower-arranged outer peripheral section (second vertical section) 55 Bottom 54d Recessed storage area 56 Insulation 56a Lower part of insulation (first insulation) 56b Upper part of insulation (second insulation) 56c protrusion 57 Bottom plate 58 Fixtures 58a Bis 60 Floor structure 61 Concrete 71 Formwork A Opening C circumferential direction D1 Outer circumference D2 Inner side G Gap

Claims

1. A receiving frame provided in an opening (A) of a floor structure (60) of a building; A fire-resistant floor hatch (10) comprising: an opening / closing cover (50) made of a heat insulating material (56), supported on the inner peripheral edge of the receiving frame, and capable of closing the opening, The heat insulating material is A fire-resistant floor hatch having a lower insulation material (56a) arranged on the inner side of the receiving frame, and an upper insulation material (56b) located above the lower insulation material and protruding toward the outer periphery more than the lower insulation material, covering the gap between the lower insulation material and the receiving frame.

2. The receiving frame is configured using an upper receiving frame (20) provided at the upper edge of the opening, a lower receiving frame (30) provided at a position located below the upper edge, and connecting members (24) that connect the upper receiving frame and the lower receiving frame at multiple points in the circumferential direction (C), The opening and closing cover is configured as a lower cover (50) that has the heat insulating material and is supported by the lower receiving frame, The fire-resistant floor hatch according to claim 1, further comprising an upper cover (40) supported by the upper receiving frame to openably and closably close the opening.

3. The opening / closing lid has a placement member (52) in which the heat insulating material is placed, and a lid member (51) that covers the heat insulating material and the placement member from above, A fire-resistant floor hatch as described in claim 1 or 2, wherein the protruding portion (56c) of the upper part of the insulation material, which protrudes more radially outward than the lower part of the insulation material, is positioned above the inner peripheral edge portion of the receiving frame while being surrounded by the positioning member and the cover member.

4. A fire-resistant floor hatch as described in claim 3, wherein the positioning member has an outer peripheral positioning portion (54a) that covers the outer peripheral side of the protrusion, a lower peripheral positioning portion (54b) that bends from the lower end of the outer peripheral positioning portion toward the inner peripheral side to cover the lower side of the protrusion, and an upper peripheral positioning portion (53) that bends from the upper end of the outer peripheral positioning portion toward the inner peripheral side or the outer peripheral side to attach the cover member.

5. An inner peripheral bent portion (34) bent upward is formed on the inner peripheral edge portion of the receiving frame, a seal member (35) is disposed on the outer periphery of the inner periphery bent portion, and is sandwiched between the inner periphery bent portion and the lower portion of the arrangement to seal the gap between the receiving frame and the lower portion of the arrangement; A peripheral bent portion (51a) bent downward is formed on the peripheral edge portion of the outer periphery of the cover member, A fire-resistant floor hatch as described in claim 4, wherein when the cover member is attached to the positioning member and the cover member is attached to the receiving frame, the amount of compression of the sealing member is determined by the outer peripheral bending portion abutting against the receiving frame.

6. The heat insulating material is composed of a first heat insulating material (56a) constituting the lower part of the heat insulating material and a second heat insulating material (56b) constituting the upper part of the heat insulating material and laminated on the upper side of the first heat insulating material, A fire-resistant floor hatch as described in any one of claims 3 to 5, wherein the outer peripheral portion of the placement member has a stepped shape that covers the first insulating material and the second insulating material from the outer peripheral side.

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