JP2017204939A - Fire protection structure, construction method of fire protection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire protection structure, and the like, excellent in workability.SOLUTION: A fire protection member 5b is a rectangular member of substantially same size as the internal size of a body 3a. The fire protection 5b is placed in the body 3a from the opening 3c of a wiring box 3, and stuck to an inner surface facing the opening 3c. A fire protection member 5a has a substantially same size as a marginal part 3b, and is a sheet-like or tabular member. The fire protection member 5a is provided with a slit 15. The slits 15 are formed along a pair of opposing sides, respectively, and a slit 15 is formed furthermore so that the opposing slits 15 are connected substantially in the center thereof. More specifically, the slits 15 are formed substantially in H-shape.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fire prevention structure in a power supply box or the like provided on a wall and a construction method thereof.

  It is necessary to prevent a part of a wall part constituting a structure, particularly a building of a certain size or more, from spreading to other sections when a fire occurs on one side of the wall part. For this reason, a fire prevention member etc. are used for a wall part.

  On the other hand, a wiring box or the like may be attached to the wall portion. In this case, it is necessary to form a through hole in the wall portion and perform wiring or the like. When such a wiring box or the like is provided in this through hole, it is necessary to prevent the fire from spreading to other sections through the wiring in the event of a fire. For this reason, it is necessary to perform a fire prevention treatment on the through hole.

  Various methods have been proposed for such a fireproofing method. For example, there is a method of attaching a thermal expansion sheet to inner and outer surfaces and edges of a wiring box (Patent Document 1).

JP 2014-239635 A

  FIG. 6 is a diagram showing a process of forming a conventional fire prevention structure. The wiring box 100 has an opening 101 on one side, and a flange-shaped edge 103 is provided on the outer periphery of the opening 101. The edge portion 103 is a portion facing the wall portion or the like. In order to fill a gap between the wiring box 100 and the wall portion, the edge portion 103 is provided with a fire prevention member 105 cut in accordance with the shape of the edge portion 103.

  The fire prevention member 105 is divided into a rectangular ring shape (shown) having a narrow width along the edge portion 103 or each side so as not to block the opening portion 101 when being attached to the edge portion 103. The four strip-shaped ones are used. Moreover, since the fireproof member 105 is a thermally expandable sheet or a plate-like putty member, it is a soft member. For this reason, the fireproof member 105 has low rigidity and is difficult to handle.

  FIG. 7 is a conceptual front view showing a state in which the fireproof member 105 is attached to the wiring box 100. As described above, the fire-proof member 105 is soft. In particular, when the fire-proof member 105 is a non-curing self-fusing type fire-proof member, the fire-proof member 105 itself sticks, so it is neatly attached at a desired position. It is difficult to attach.

  For example, wrinkles such as sticking of the fire prevention members 105 (X in the drawing), misalignment (Y in the drawing), and screw hole closing (Z in the drawing) due to this may occur. In this case, it is necessary to re-apply the fireproof member 105 and the workability is poor. Moreover, if it is attached in a state where wrinkles or misalignment occurs, it may not be possible to obtain a desired fireproof performance.

  This invention is made | formed in view of such a problem, and it aims at providing the fire prevention structure etc. which were excellent in workability.

  In order to achieve the above-described object, the first invention includes a wiring box disposed on a wall, a first fire prevention member provided at least between an edge of the wiring box and one surface of the wall, A second fire-proof member disposed on an inner surface facing at least the opening of the wiring box, and the first fire-proof member is a sheet-like or plate-like member with a notch, The fireproof structure is characterized in that a part of the first fireproof member is folded into an inner surface of the wiring box by the cut.

  The thickness of the second fireproof member is desirably thicker than the thickness of the first fireproof member.

  The first fire prevention member and the second fire prevention member are preferably made of a non-curable self-bonding putty member.

  According to the first aspect of the invention, the first fire prevention member disposed at the edge of the wiring box is a sheet-like or plate-like member, and the notch of the fire prevention member is folded, so that the first fire prevention member is positioned. Is easy and wrinkles are less likely to occur. For this reason, the pasting workability is good.

  Moreover, since the 2nd fireproof member thicker than the 1st fireproof member is arrange | positioned inside a wiring box, fireproof performance can be ensured reliably. Moreover, since the thickness of the 1st fireproof member is thin, the usage-amount of a fireproof member can be reduced.

  Further, if the first fire-proof member and the second fire-proof member are non-curing self-bonding types made of butyl rubber or the like, an adhesive or the like is unnecessary, and the falling off can be prevented by its own adhesive force. . For this reason, an adhesive layer or the like for holding the fireproof member is unnecessary.

  A second invention is a construction method for forming a fire prevention structure on a wall, wherein a first fire prevention member is arranged on an edge and an inner surface of a wiring box, and a first fire prevention member is arranged on an inner surface facing the opening of the wiring box. And a step of fixing the wiring box to one surface of the wall. The first fire-proof member is a sheet-like or plate-like member that has been cut in advance. And by folding a part of the first fireproof member into the inner surface of the wiring box by cutting, the first fireproof member is disposed on the edge and inner surface of the wiring box. It is the construction method of the fire prevention structure.

  According to the second aspect of the invention, the first fire prevention member can be reliably attached to the edge of the wiring box, so that the fire prevention structure can be easily constructed.

  ADVANTAGE OF THE INVENTION According to this invention, the fire prevention structure etc. excellent in workability | operativity can be provided.

Sectional drawing which shows the fire prevention structure 1. FIG. Sectional drawing which shows the fire prevention structure 1. FIG. The exploded perspective view of fire prevention members 5a and 5b. The figure which shows the process of sticking the fire prevention member 5a. The conceptual diagram which shows the thermal expansion state of the fire prevention structure 1. FIG. The disassembled perspective view which shows the conventional fire prevention structure. The front conceptual diagram which shows the affixed state of the fire prevention member 105 in the conventional fire prevention structure.

  Hereinafter, embodiments of the present invention will be described in detail. 1 and 2 are partial cross-sectional views showing a fire prevention structure 1 according to the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 1 is a cross-sectional view taken along line BB in FIG. The fire prevention structure 1 mainly includes a wall 11, a wiring box 3, fire prevention members 5a and 5b, and the like. In FIG. 1 and FIG. 2, illustration of a fixing bracket of the wiring box 3 and an assembly screw portion is omitted.

  The wall 11 is a hollow wall, for example. A through hole 13 is provided in the wall 11. On one surface of the wall 11 (inner surface of the hollow wall), the wiring box 3 is provided at the position where the through hole 13 is formed. An outlet 7 is provided on the other surface of the wall 11 so as to close the through hole 13. The wiring box 3 is fixed to a lightweight aggregate (not shown) by a fixing bracket (not shown).

  The wiring box 3 includes a main body 3a and an edge 3b. The main body portion 3a and the edge portion 3b are joined together with, for example, screws. The main body 3a is provided with an opening 3c on one side. The opening 3 c is provided so as to face the through hole 13 formed in the wall 11, and the electric wire 9 and the like are disposed in the opening 3 c and the through hole 13 and connected to the outlet 7.

  As shown in FIG. 2, the electric wire 9 passes through a hole 3 e formed in the upper and lower surfaces (inner side surfaces 3 d facing each other) of the wiring box 3 and is inserted into a conduit tube or the like outside the wiring box 3. In addition, the fire prevention structure 1 is not restricted to the example shown in figure, The number, arrangement | positioning, etc. of the electric wire 9 are set suitably.

  The edge 3b is provided in a flange shape on the outer periphery of the opening 3c. The edge 3 b is disposed on the outer peripheral portion of the through hole 13 of the wall 11. Between the edge 3b of the wiring box 3 and one surface of the wall 11, a fire prevention member 5a which is a first fire prevention member is provided. Moreover, the fire prevention member 5b which is a 2nd fire prevention member is provided in the inside of the wiring box 3, and the inner surface facing the opening part 3c.

  The fire prevention members 5a and 5b contain at least a specific binder resin, a resin balloon, and expandable graphite. The fire prevention members 5a and 5b do not contain a curable component, and their physical properties are non-curable, and are made of a self-bonding putty member. Details of the components of the fire prevention members 5a and 5b will be described later.

  As shown in FIG. 1, the fire prevention member 5 a is folded into another opposing inner side surface 3 d perpendicular to the side surface where the hole 3 e of the wiring box 3 is formed. That is, the fire prevention member 5a is continuously provided on a part of the edge 3b and the inner surface 3d of the main body 3a.

  In addition, the thickness of the fire prevention member 5b is thicker than the thickness of the fire prevention member 5a. The fire prevention member 5b has a thickness that allows the inside of the wiring box 3 to be filled by, for example, expansion when a fire or the like occurs.

  Next, details of the fireproof members 5a and 5b will be described.

[Binder resin]
The binder resin used for the fireproof members 5a and 5b is not particularly limited as long as it is a resin having a property capable of putting the composition into putty, and a commonly used resin can be adopted. For example, the binder resin is one or more selected from the group consisting of polybutene, polybutadiene, styrene butadiene rubber, butyl rubber, ethylene propylene (EP) rubber, ethylene propylene diene (EPDM) rubber, chloroprene rubber, and isoprene rubber. It can be set as the structure containing resin.
The binder resin more preferably contains one or more selected from the group consisting of polybutene, polybutadiene, butyl rubber, and isoprene rubber, more preferably one or two selected from the group consisting of polybutene, polybutadiene, and butyl rubber. It consists of more than seed resin.

  In the fire prevention members 5a and 5b, the content of the binder resin is preferably 15.0 to 50.0% by mass from the viewpoint of putting the composition into a putty shape and a putty having good hardness, and 18.0 to 18.0%. 45.0 mass% is more preferable, and 20.0-40.0 mass% is further more preferable. The binder resin can be obtained by synthesis by a conventional method. Moreover, you may use a commercial item.

[Resin micro-balloon]
The resin balloon used for the fire prevention members 5a and 5b is a hollow, lightweight particle having a spherical resin shell. In general, a resin is molded in a state in which a liquid gas is encapsulated, and this is heat-treated, so that it is expanded several tens of times in volume to obtain hollow spherical particles having a desired particle size. Resin balloons have moderate elasticity and are not easily destroyed by pressure or mechanical stress.
The resin balloon plays a role like a cushion against the shear stress during the kneading process at the time of manufacturing the putty composition, and exhibits an action of effectively suppressing the breakage (collapse) of the expandable graphite described later. Thereby, it can mix in the state which maintained the thermal expansion performance which expansible graphite inherently has favorable, and can prepare a putty composition.
In addition, by blending a resin balloon, it is possible to take a long time until the expandable graphite is crushed and the thermal expansion performance is deteriorated in the kneading step. Variations in the quality of the composition can be suppressed.
Moreover, when the shell of the resin balloon is torn during a fire, the liquid gas (hydrocarbon etc.) in the balloon burns, and the thermal expansion of the expandable graphite existing in the vicinity can be effectively promoted.

The resin constituting the shell of the resin balloon is not particularly limited as long as the resin balloon can be formed. For example, the resin constituting the shell of the resin balloon can be configured to include a resin selected from the group consisting of acrylonitrile resin, phenol resin, and vinylidene chloride resin. Especially, it is preferable that resin which comprises the shell of a resin balloon consists of resin chosen from the group which consists of acrylonitrile resin, a phenol resin, and vinylidene chloride resin. In the present specification, the resin selected from the group consisting of acrylonitrile resin, phenol resin, and vinylidene chloride resin is selected from the group consisting of acrylonitrile resin, phenol resin, and vinylidene chloride resin as long as the effects of the present invention are not impaired. It is meant to include a modified resin, for example, a copolymer.
When the shell of the resin balloon contains a resin selected from the group consisting of acrylonitrile resin, phenol resin, and vinylidene chloride resin, it is possible to effectively suppress the collapse of expandable graphite during pressure kneading. Further, it is considered that the shell tends to cause incomplete combustion at the time of combustion, and the generated soot acts as a binder and acts to suppress the putty of the putty after thermal expansion.

The average particle diameter of the resin balloon used for the fireproof members 5a and 5b is usually 10 to 150 μm, and more preferably 50 to 80 μm. The average particle diameter was determined by measuring the particle size distribution by a laser diffraction method (measuring instrument: SALD-2000 / Shimadzu Corporation), and was the particle diameter when the cumulative volume was 50%.
The true specific gravity of the resin balloon used for the fireproof members 5a and 5b is preferably 0.02 to 0.07. Therefore, by using a resin balloon, the putty composition can be reduced in weight, and transportability or workability can be improved.
The resin balloon may be used as it is, or a product having a true specific gravity of about 0.1 to 0.3 may be used by combining with an inorganic powder for easy handling.

  In order to effectively express the above action, the content of the resin balloon in the fire prevention members 5a and 5b is preferably 0.4 to 15.0 mass%, more preferably 2.0 to 14.0 mass%. 2.5 to 13.0 mass% is more preferable.

  The resin balloon used for the fireproof members 5a and 5b can be manufactured by a conventional method, and a commercially available product can also be used. Commercially available resin balloons include, for example, EMC40 (trade name, manufactured by Nippon Philite), Fenoset Microsphere BJO-930 (trade name, manufactured by Malayan Adhesive & Chemicals), Matsumoto Microsphere (trade name, Matsumoto Yushi Seiyaku Co., Ltd.) Manufactured).

[Expandable graphite]
The expansive graphite used for the fire protection members 5a and 5b has a thermally decomposable substance between the layers of hexagonal crystals in which the two-dimensionally spreading six-membered ring network plane layers are laminated in the C-axis direction. Intercalation compound inserted. For example, after immersing graphite in an oxidizing solution containing fuming sulfuric acid, sulfuric acid and concentrated nitric acid, various nitrates, perchloric acid, various perchlorates, chromic acid, various chromates, dichromic acid, etc., then rinse with water Manufactured by drying.
When expansive graphite is heated rapidly, the compound inserted between the layers and the compound inserted into the crystal grain boundary are thermally decomposed, and the pressure of the decomposition gas generated at that time pushes the space between the layers. Swell.

  It is preferable to use expansive graphite in powder form. From the viewpoint of effectively expressing the thermal expansibility of the thermally expansible graphite, the content of expansive graphite in the fire protection members 5a and 5b is preferably 5.0 to 40.0 mass%, and 6.0 to 35. 0 mass% is more preferable, and 7.0-30.0 mass% is further more preferable.

In the fire prevention members 5a and 5b, the ratio of the resin balloon content to the expandable graphite content (resin balloon content / expandable graphite content (volume ratio)) is preferably 0.2 to 14.0. 2.0-13.0 are more preferable, 2.1-12.0 are more preferable, and 2.3-10.0 are further more preferable.
By making the ratio of the contents of expandable graphite and resin balloon within the above preferred range, the destruction of expandable graphite during production can be more effectively suppressed, and the thermal expansion performance of the putty composition can be further enhanced.

  Expandable graphite is commercially available. For example, SS-3 (trade name, manufactured by Air Water), 955025L (trade name, manufactured by Ito Graphite Industries, Ltd.) and the like can be used.

[Inorganic filler]
The fireproof members 5a and 5b are one or more selected from the group consisting of aluminum hydroxide, magnesium hydroxide, talc, clay, calcium carbonate, inorganic balloon, aluminum oxide, magnesium oxide, and silica as inorganic fillers. In this case, it is more preferable to include one or more selected from the group consisting of aluminum hydroxide, magnesium hydroxide, talc, and calcium carbonate.
In order to allow the fire prevention members 5a and 5b to maintain a good shape during a fire without significantly increasing the specific gravity of the fire prevention members 5a and 5b, the content of the inorganic filler in the fire prevention members 5a and 5b is 50.0 mass% or less is preferable and 40.0 mass% or less is more preferable. Moreover, although the fire prevention member 5a, 5b does not need to contain an inorganic filler, it is preferable to contain 5 mass% or more of inorganic fillers in the fire prevention members 5a, 5b, and more preferably to contain 10 mass% or more. The content is preferably 15% by mass or more.

[Flame retardant (deformation inhibitor)]
The fire prevention members 5a and 5b preferably contain a flame retardant. The flame retardant has the effect of suppressing the deformation of the putty composition during a fire. The flame retardant is preferably one or more selected from the group consisting of polyphenylene ether, phosphate ester, red phosphorus, and ammonium polyphosphate, and one or two selected from ammonium polyphosphate and polyphenylene ether Is preferred.
In the fire prevention members 5a and 5b, the content of the flame retardant is preferably 40.0% by mass or less, more preferably 5.0 to 35.0% by mass, and still more preferably 10.0 to 35.0% by mass. Note that, as the content of the flame retardant increases, the effect of suppressing the deformation of the shape increases.

[Plasticizer]
A plasticizer can be used for the fire prevention members 5a and 5b in order to improve the softness, adhesiveness, touch and the like of the composition. In addition, when a plasticizer is used, when the fire contact members 5a and 5b come into contact with a plastic sheath containing a plasticizer or the like, it is possible to prevent the migration of the plasticizer between them and to suppress the influence of the migration of the plasticizer. As the plasticizer, benzoic acid ester compounds, epoxy compounds, phosphoric acid ester compounds, chlorinated paraffin compounds, adipic acid compounds, phthalic acid ester compounds, and the like are suitable.
When the fire prevention members 5a and 5b contain a plasticizer, the content of the plasticizer in the fire prevention members 5a and 5b is preferably 5.0 to 20.0 mass%, and more preferably 7.0 to 16.0 mass%. .

  In the fire prevention members 5a and 5b, in addition to the above-described components, a surfactant or a lubricant may be added as a processing aid for facilitating production. Moreover, you may mix | blend an appropriate quantity with the anti-aging agent for a storage property and a weather resistance improvement, the fiber chip for the shape retention property improvement at the time of construction, etc.

The fire prevention members 5a and 5b according to the present embodiment can be obtained by kneading each raw material by a conventional method using a known kneader mixer, Banbury mixer, or the like to obtain a homogeneous putty-like composition.
The temperature during kneading is preferably 60 to 70 ° C. The kneading time is preferably 5 to 20 minutes.

  Thus, the fireproof members 5a and 5b can be easily bonded to the wiring box 3 by making the fireproof members 5a and 5b non-curing self-bonding type made of butyl rubber or the like. Moreover, the fireproof members 5a and 5b have extremely strong adhesive force, and there is no decrease in adhesive force due to deterioration. In addition, when the fireproof members 5a and 5b are not of the self-bonding type, a separate adhesive layer may be provided on the surface of the fireproof members 5a and 5b.

  Next, a construction method for forming the fire prevention structure 1 on the wall 11 will be described. FIG. 3 is an exploded perspective view of the fire prevention structure 1. The fire prevention member 5b is a rectangular member having substantially the same size as the inside size of the main body 3a. As described above, the fire prevention member 5b is inserted into the main body 3a from the opening 3c of the wiring box 3, and is attached to the inner surface facing the opening 3c.

  The fire prevention member 5a is substantially the same size as the edge 3b, and is a sheet-like or plate-like member. The fire protection member 5a is provided with a cut 15. The notches 15 are formed along a pair of opposing sides, and the notches 15 are further formed so that the opposing notches 15 are connected to each other at substantially the center of each other. That is, the cut 15 is formed in a substantially H shape.

  When affixing the fire protection member 5a to the edge 3b, as shown in FIG. 4A, a part of the fire protection member 5a is bent by the notch 15 (arrow C in the figure) to the edge 3b. Deploy. That is, the fire prevention member 5a is arranged on the edge 3b so that the substantially central vicinity of the fire prevention member 5a is pushed into the inner side of the wiring box 3.

  From this state, as shown in FIG. 4B, the vicinity of the outer peripheral portion of the fire prevention member 5a is affixed to the edge portion 3b, and the vicinity of the central portion of the fire prevention member 5a folded by the notch 15 is attached to the inner surface of the main body 3a. Paste to 3d. The fire prevention member 5a (folded in the drawing D) is easily positioned on the edge portion 3b corresponding to the inner side surface 3d to which the fire prevention member 5a is attached by folding the fire prevention member 5a and attaching the fire protection member 5a to the opposing inner side surface 3d. can do. Moreover, since the fire prevention member 5a is folded in the said part, rigidity is improved by a bending part and wrinkles etc. are hard to produce to the fire prevention member 5a.

  In addition, by attaching the fireproof member 5a to the opposing inner side surface 3d, an appropriate tension is applied to both sides of the fireproof member 5a (E in the figure) on the edge 3b on the side orthogonal thereto. For this reason, in the said site | part, wrinkles etc. are hard to generate | occur | produce in the fire prevention member 5a, and positioning is easy.

  In this manner, the fireproof member 5a is disposed on the edge 3b and the inner side surface 3d of the wiring box 3, and the fireproof member 5b is disposed on the inner surface facing the opening 3c of the wiring box 3. Thereafter, the fire prevention structure 1 is formed by fixing the wiring box 3 to one surface of the wall 11. The arrangement order of the fire prevention members 5a and 5b may be any. Moreover, the fire prevention member 5a folded into the inner side surface 3d may be attached to at least a part of the inner side surface 3d, and may not be disposed in the entire depth direction. Further, a part of the fire prevention member 5a may be disposed so as to overlap the fire prevention member 5b.

  Next, the fireproof performance of the fireproof structure 1 will be described. As shown in FIG. 5 (a), when a fire occurs on the wall 11 at the outlet 7 side, heat is transferred from the outlet 7 side to the wiring box 3 (F in the figure). At this time, the portion in the vicinity of the opening 3c of the fireproof member 5a attached to the inner side surface 3d starts to expand first (G in the figure). Thereby, the opening 3c is slightly blocked.

  Further, as shown in FIG. 5B, when heat is transferred to the inside of the wiring box 3, the fire prevention member 5b starts to expand (I in the figure). At this time, since the fireproof member 5a is expanded, a part of the inside of the main body 3a is filled, so that the fireproof member 5b can be expanded so as to fill the whole of the main body 3a in a short time. Therefore, it is possible to fill the internal space of the wiring box 3 in a short time and prevent the fire from spreading.

  As described above, according to the present embodiment, the fire prevention member 5 a can be easily disposed on the edge 3 b of the wiring box 3. For this reason, it is hard to produce a wrinkle, position shift, etc. to the fire prevention member 5a, and workability | operativity is favorable. Further, for example, it is not necessary to cut each of the sides in a strip shape, and since the fire prevention member 5a is integrated, there is no gap between the members, and the pasting operation can be performed only once.

  Moreover, since the fireproof members 5a and 5b are self-bonding types, the fireproof members 5a and 5b can be fixed by simply attaching the fireproof members 5a and 5b to each part of the wiring box 3. Further, since no adhesive or the like is used, there is no decrease in adhesive force due to deterioration, and the fire-proof members 5a and 5b can be prevented from falling off.

  Moreover, since the fire prevention member 5b has sufficient thickness, the fire prevention member 5a can be made thin and fire prevention performance can be ensured with the minimum amount of use of the thermal expansion member.

  For 10 wiring boxes, the time for attaching the fireproof member to the edge was measured. In the example, the work was performed by the method shown in FIGS. In the comparative example, the fireproof member was cut into four pieces and pasted on four sides. In addition, the number of failures that occurred in each operation was measured. The results are shown in Table 1.

  In the comparative example, since the number of fire-proof members used increased, it took time to peel off the release paper, and it was difficult to handle, and many wrinkles and misalignment occurred. Furthermore, the screw position blockage which closed the screw hole in the front edge part of a wiring box generate | occur | produced because the position shifted. As a result, re-attachment of the fireproof member occurred, which took more time.

  On the other hand, in the example, since one fireproof member was bent from the notch according to the wiring box shape, the position was easily determined, and no positional deviation occurred. In addition, the construction time can be shortened because one piece of construction is possible.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1 ......... Fire prevention structure 3 ......... Wiring box 3a ......... Body part 3b ......... Edge part 3c ......... Opening part 3d ......... Inner side surface 3e ......... Hole 5a, 5b ......... Fire prevention member 7 ......... Outlet 9 ...... Wire 11 ......... Wall 13 ......... Through hole 15 ......... Incision 100 ......... Wiring box 101 ......... Opening 103 ...... Edge 105 ...... Fireproof member

Claims (4)

A wiring box placed on the wall,
A first fire prevention member provided at least between an edge of the wiring box and one surface of the wall;
A second fireproof member disposed on an inner surface facing at least the opening of the wiring box;
Comprising
The first fire prevention member is a sheet-like or plate-like member into which a cut is made, and a part of the first fire prevention member is folded into an inner surface of the wiring box by the cut. Fire prevention structure characterized by that.   2. The fire prevention structure according to claim 1, wherein a thickness of the second fire prevention member is larger than a thickness of the first fire prevention member.   3. The fire prevention structure according to claim 1, wherein the first fire prevention member and the second fire prevention member are made of a non-curable self-bonding putty member. 4. A construction method for forming a fire prevention structure on a wall,
Arranging the first fire prevention member on the edge and the inner surface of the wiring box, and arranging the second fire prevention member on the inner surface facing the opening of the wiring box;
Fixing the wiring box to one side of the wall;
Comprising
The first fireproof member is a sheet-like or plate-like member that has been cut in advance, and by cutting a part of the first fireproof member into the inner surface of the wiring box, A construction method for a fireproof structure, wherein a first fireproof member is disposed on an edge and an inner surface of the wiring box.

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