JPH09291621A - Fitting structure of fire-resistant panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fitting structure of fire-resistant panels excellent in the waterproof property, to constitute a fireresistant structure. SOLUTION: A plurality of fire-resistant panel strips A in which a noncombustible sheet 4 is formed on a metallic panel strip 3 with a nearly inverted T-shaped section are fixed at a fixed pitch. A fire-resistant panel B formed as a fitting structure (spline Joint structure) by forming a core material 6 made of plastic foam 15 between the front face material 5 and the rear face material 7 and inserting a noncombustible board C between both ends, is fixed on the whole wall face between the fire-resistant panel strips A by fastening tools β. And fitting tools E are fixed on the ends of fire-resistant panels B by fastening tools β1 . And further, the fitting part 30 of the joint cover F is fitted to the fixing part 23 of the fitting tools E to integrally form them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to construction,
It can be used as an exterior wall material, roof material, ceiling material, floor material, partition material, fire door, etc., and has no deformation such as swelling or warpage after production, and has excellent fire resistance, fire resistance, and mechanical strength. The present invention relates to a panel mounting structure.

[0002]

2. Description of the Related Art In general, many fireproof panels in which a core material made of a synthetic resin foam (for example, phenol foam) is sandwiched between a thin plate-shaped surface material and a back surface material have been invented, invented and put on the market. Typical mounting structures include, for example, Japanese Utility Model Laid-Open No. 3-35137, Japanese Utility Model Laid-Open No. 3-93535, and the like.

[0003]

However, in the above-mentioned mounting structure, the joint portion formed by connecting the panels is inferior in fire resistance, and for example, the core material of the panel is made of a phenol foam excellent in fireproofness. Even if used, in the fire resistance test, the backside temperature of the joint portion rises above the specified value,
It was not possible to obtain a fireproof 30-minute structure.

[0004]

In order to eliminate such drawbacks, the present invention fixes a plurality of fire resistant pavement plates having a non-combustible sheet formed on a metal pavement plate having a substantially inverted T-shaped cross section at a constant pitch. Then, a core material made of plastic foam is formed between the front surface material and the back surface material, and a non-combustible board is inserted between the end parts to form a mating structure fireproof panel with a fixture on all wall surfaces between fireproof tiles. Fix and fix the fixture on the fixed part between the fireproof panels with the fixture, and further attach the engaging part of the joint cover to the locking part of the fixture to mount the fireproof panel integrally formed. It provides the structure.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a fireproof panel mounting structure according to the present invention. That is, FIG. 1 is a partially cutaway perspective view showing the mounting structure of the fireproof panel, and FIG. 2 is a sectional view showing the mounting structure of the fireproof panel, where α is a frame, β is a fixture, and β1 is a fixture. The head of β, A is a fireproof floorboard, B is a fireproof panel, C is a non-combustible board, D is a cover material consisting of a fixture E and a joint cover F, and G is a joint.

More specifically, as shown in FIG. 3, the fireproof flooring sheet A has a substantially flat T-shaped cross section from a horizontal fixed piece 1 and a rising piece 2 projecting upward from approximately the center of the fixed piece 1. It is a long sheet made of a metal sheet 3 formed on the sheet and a non-combustible sheet 4 formed on the surface side in the figure of the sheet 3, and a metal sheet is formed by roll forming or extrusion forming. A non-combustible sheet 4 is integrated with the molded sheet 3 with an adhesive or the like. 1a is a tongue piece for enhancing waterproofness and preventing danger.

As shown in FIG. 1, the fireproof panel A is formed on the back surface of the joint G of the fireproof panel B to prevent infiltration of rainwater, flame, etc. from the space between the fireproof panels B to the frame α side. It functions as a guide or the like when fixing the panel B.

The non-combustible sheet 4 is, for example, a sheet of inorganic fiber, and is made of one or more of rock wool felt, ceramic wool, glass wool, and the like.

As shown in FIG. 4, the refractory panel B has a hat-shaped cross section and a long surface material 5, and a surface material 5.
The core material 6 having a hat-shaped cross section formed on the back surface of the core material 6 and the back surface material 7 covering at least the back surface in the longitudinal direction of the core material 6 are formed into a sandwich structure.

The surface material 5 is a horizontal surface 8, a side wall 9 that is bent at both side edges of the surface 8 inward, perpendicular to the surface 8 or inclined inward, and a lower end of the side wall 9. And a groove strip 11 in which the head portion β1 of the fixture β is recessed so that the head portion β1 of the fixture β can be stored.
A guide portion 12 in which the tip of the protruding piece 10 is inclined downward and bent, a reinforcing piece 13 in which an end edge of the guide portion 12 is bent inward in an L-shape, and the tip of the reinforcing piece is inside the core member 6. It is formed from the extension piece 14 extended to the.

The groove 11 is formed by accommodating the fixture β so that the head β1 of the fixture β to which the fireproof panel B is fixed does not get in the way when the fixture E is fixed, which will be described later. For this reason, even if the fixture E is formed in a long shape, the fixture E can be fixed after the fireproof panel B is fixed. In addition, when fixing without forming the groove 11, if the fixture E is short, the fixing portion 14 of the fireproof panel B exposed between the fixtures E may be fixed by the fixture β. Fireproof panel B when using a long one
And the fixture E had to be fixed at the same time, and there was a problem in workability. By forming the groove 11 in this manner, the mounting tool E can be reliably installed without any problem in workability regardless of whether it is long or short.

By forming the guide portion 12 so as to be inclined, it is effective to support the stabilizing piece 24 of the mounting tool E, which will be described later, as shown in FIGS. 1 and 2, and to secure the fixing position of the mounting tool E. Is.

The reinforcing piece 13 prevents the plastic foam 15 from leaking to the guide portion 12 and the surface side of the protruding piece 10 when filling the plastic foam 15 which is the raw material of the core material 6, and the side of the fireproof panel B. By improving the dimensional accuracy of the working width by improving the dimensional accuracy of the refractory panel B by making the edges straight, and by eliminating the gap between the joint portions G and improving the heat insulating property, airtightness and the like. .

Further, since the extension piece 14 is extended to the inside of the core material 6, the adhesion strength between the surface material 5 and the core material 6 is improved, and the fixture β for fixing the fireproof panel B also penetrates the extension piece 14. Therefore, the mounting strength of the fireproof panel B is improved. Further, the guide portion 12, the reinforcing piece 13, and the extension piece 14 also function as reinforcement of the refractory panel B itself.

As shown in FIG. 4, the backing material 7 mainly covers the back surface of the core material 6 and has the functions of a reinforcing material, a waterproof material, a moistureproof material, and a fireproof material, and the core material 6 directly contacts the frame α. It also serves as an isolation material to prevent the occurrence of rust.

As for the shape of the back surface material 7, the horizontal back surface decorative surface 16 and both ends of the rear surface decorative surface 16 are inwardly L-shaped.
The reinforcing piece 17 is bent in a letter shape, and the extending piece 18 is formed by extending the tip of the reinforcing piece 17 into the core 6.

Further, the reinforcing piece 17 is the reinforcing piece 1 of the surface material 5.
3, the front surface material 5 and the back surface material 7 are integrated with each other to prevent the plastic foam 15 from leaking, and
It serves to improve the edge strength of the back surface material 7.

Further, since the extension piece 18 is extended to the inside of the core material 6, the adhesion strength between the surface material 5 and the core material 6 is improved, and the fixture β for fixing the fireproof panel B also penetrates the extension piece 18. Therefore, the mounting strength of the fireproof panel B is improved.

Further, the reinforcing pieces 13 and 17 form a convex male part 19 at one end of the fireproof panel B and a concave female part 20 at the other end, and the male part 19 and the female part are formed. An insertion groove 21 is formed by recessing the middle of the portion 20 in a U shape.

When connecting the fireproof panels B to each other, the male part 19 is inserted and connected to the female parts 20 of the adjacent fireproof panels B to improve the connection strength, and the male part 19 and the female part 20 are connected. A non-combustible board C, which will be described later, is inserted and filled mainly in the insertion groove 21 having a U-shaped depression in the middle thereof for the purpose of improving the fire resistance performance of the joint portion G.

The surface material 5 and the back surface material 7 are thin metal plates such as iron, aluminum, copper, stainless steel, titanium and aluminum.
Zinc alloy plated steel plate, galvalume steel plate, enameled steel plate, clad steel plate, laminated steel plate (PVC steel plate, etc.), sandwich steel plate (damping steel plate, etc.), vinyl chloride resin, polycarbonate resin, etc. (Of course, these are painted in various colors. A variety of shapes, including rolls, presses, extrusions, etc.
Alternatively, an inorganic material is formed into various arbitrary shapes by extrusion molding, press molding, autoclave culturing, etc., and further, aluminum vapor-deposited paper, asbestos paper, kraft paper, asphalt felt, metal foil (A
1, Fe, Pb, Cu), a synthetic resin sheet, a rubber sheet, a cloth sheet, a gypsum paper, an aluminum hydroxide paper, a glass fiber nonwoven fabric, or a laminate of two or more kinds, or a waterproof treatment, difficult It is made of a sheet-like material that has been subjected to a combustion treatment.

The core material 6 is a plastic foam 15
Made of polyurethane foam, polyisocyanurate foam, phenol foam, vinyl chloride foam, polyethylene foam,
It is made of a synthetic resin foam such as polystyrene foam or urea foam. For example, a stock solution of resol-type phenol, a curing agent and a foaming agent are mixed and discharged onto the front surface 5 or the back surface of the back material 7. It is formed by heating to react, foam, and cure. In the plastic foam 15, lightweight aggregates (perlite grains, glass beads, gypsum slag, talc stones, shirasu balloons, aluminum hydroxide, etc.), fibrous materials (glass wool, rock wool, carbon fibers, etc.) are used as various flame retardant materials. Graphite, etc.) can be mixed to improve fire resistance and fire resistance.

Further, as a concrete example of the plastic foam 15, a resol type phenol foam is mixed with a foaming agent, aluminum hydroxide (Al (OH) ₃ ), ammonium polyphosphate, graphite, a curing agent, and the like,
Foam, harden, and finish density 50-300Kg / m
^It was formed in ^3rd place. When a wall is formed by using the fireproof panel B using this plastic foam 15, JIS-A-1304 (fireproof by each fireproof performance 30
Min., Fireproof 1 hour, fireproof 2 hours). Fireproof structure of 1 hour.

Resol type phenolic foam (hereinafter,
Phenol foam) is manufactured mainly by a continuous foam molding method and has nonflammability, low smoke emission and low toxicity compared to other synthetic resin foams (plastic foam). It is. The metal siding material formed by sandwiching the phenol foam on a metal plate is JIS-A-1301 alone.
(Fire test method for wooden part of building), JIS-A-1
It has a fire protection performance that passes a fire protection structure test of 302 (fire prevention test method for a non-combustible structure portion of a building).

As the foaming agent, a stock solution of phenol foam was used.
When the amount is 0 part by weight, 2 to 50 parts by weight is mixed with the undiluted solution of the phenol foam, and examples thereof include methylene chloride and carbonate (powder).

Aluminum hydroxide is mixed in an amount of 50 to 300 parts by weight based on 100 parts by weight of the undiluted solution of phenol foam, and is useful as a flame-retardant material, a refractory material, and a heat-resistant material. Is. For example, the composition has a water content of 0 to 30%, a particle size of 10 to 100 μ, and a purity of 90% or more.

Ammonium polyphosphate is used as a reaction adjusting material and a flame retardant material, when 1 to 25 parts by weight of the phenol foam stock solution is mixed with the phenol foam stock solution. The particle size is 30-100 μ.

The graphite is mixed in an amount of 2 to 30 parts by weight based on 100 parts by weight of the phenol foam stock solution. The effect is that the phenol foam is carbonized at the time of fire and voids are formed. However, the voids are closed by the graphite expanded by heating to prevent a decrease in fire resistance performance due to thinning.

The curing agent is a phenol foam stock solution of 10 parts.
If it is 0 parts by weight, it is mixed with 10 to 50 parts by weight based on the stock solution of the phenol foam, and is an organic phosphoric acid type or a mixture of a phosphoric acid type and a PSA type.

FIG. 5 is a perspective view showing the incombustible board C.
The non-combustible board C has a long plate shape. Further, as shown in FIGS. 1 and 2, the non-combustible board C is used to enhance the fire resistance of the joint portion G, and is used for passing the fire resistant structure 1 hour test of the fire resistant structure test of JIS-A-1304. Such as calcium silicate board, calcium carbonate board, gypsum board, perlite cement board, rock wool board, slate board, ALC board, PC board, other inorganic lightweight body, inorganic lightweight foam, or composite board thereof. Of 1
Insertion groove 21 in which a refractory panel B is formed of at least one kind or ultra high density resin (high density phenol foam, etc.)
To intervene. The incombustible board C also functions as a guide when the fireproof panel B is installed.

The cover material D comprises a fitting E and a joint cover F. The fitting E is, as shown in FIGS. 6 (a) and 6 (b),
It is a long-shaped or short-shaped metal plate material formed by bending, and includes a horizontal plane-shaped fixing portion 22 and a locking portion 23. More specifically, the fixing portion 22 has a horizontal plane shape, and is composed of a fixing member β driving portion and a stabilizing piece 24 that serves as a mark for the attachment position, which is formed by protruding the fixing portion 22 in the middle thereof downward. Of course, as shown in the drawing, the fixing holes 22a for driving the fixing tool β can be formed in the fixing portion 22 at a constant pitch P to improve the workability.

The engaging portion 23 has a rising piece 25 in which both end edges of the fixing portion 22 are bent upward, and a rising piece 25.
Is formed from a locking piece 26 that is bent outward and protrudes. The material is a metal material, for example, a color steel plate, stainless steel, or the like. Further, the locking piece 26 locks the engaging piece 29 of the joint cover F, which will be described later, and
Is to be fixed to the joint portion G between the fireproof panels B.

As shown in FIG. 7, the joint cover F is made of the above-mentioned metal thin plate material, and its shape is a horizontal surface 27 and a side wall 28 with both end edges of the surface 27 bent downward. And an engaging piece 29 bent inwardly with the tip of the side wall decorative surface 28 into a shape capable of engaging with the engaging piece 26 described above.
And the engaging portion 30 including.

More specifically, in the decorative surface portion 27, the joint cover F is fixed to the joint portion G by the fitting E as shown in FIGS.
The purpose is to cover the fixture β used when fixing it on the top so that the fixture β is not exposed to the outside.

The engaging piece 29 is the engaging piece 26 of the fixture E.
The joint cover F is fitted to the fixture E to securely fix the joint cover F on the joint portion G without detachment.

Next, a construction method for forming the fireproof panel mounting structure according to the present invention will be described. 1 and 2
In order to form the outer wall as shown in FIG. 3, the fireproof floorboard A and the fireproof panel B in which the noncombustible sheet 4 made of rock wool felt is formed on the floorboard 3 made of a thin metal plate material as shown in FIG. As shown in FIG. 4, 0.5 mm thick colored steel plates are used as the front surface material 5 and the rear surface material 7, and a raw material made of phenol foam is used as the plastic foam 15 between the front surface material 5 and the rear surface material 7. Filled in
The non-combustible board C was formed by reacting, foaming and then curing to 150 Kg / m ³ , and the non-combustible board C had a shape as shown in FIG. 5 and was made of a calcium silicate plate. The fixture E is made of stainless steel (0.6 mm thick) as shown in FIG.
As the joint cover F, the same material as the surface material 5 is roll-molded and formed as shown in FIG.

Therefore, a frame A made of C-shaped steel (lip groove type steel material) is vertically provided with a fire-resistant siding board A as shown in FIG.
A plurality of fixtures are fixed at a pitch of 0 mm by a fixture β. When the attachment (allocation) of the fire-resistant floor covering A is completed, the non-combustible board C is inserted into the insertion groove 21 of the fire-resistant floor covering A, and the groove 11 of the fire-resistant panel B is fixed to the frame α by the fixture β.
The fireproof panel B and the incombustible board C are fixed to the entire surface of the wall by continuously performing such steps.

After the joint portion G between the fireproof panels B is formed in this manner, the fixing portion 22 of the fixture E is fixed on the protruding piece 10 of the fireproof panel B by the fixture β. Fixture E
When all of the attachments are completed, the locking portion 2 of the attachment E
3, the engaging portion 30 of the elongated joint cover F as shown in FIG. 7 is fitted, the joint portion G between the fireproof panels B is covered with the joint cover F, and the construction is completed. .

[0039]

[Other Embodiments] The above description is only one embodiment of the mounting structure of the fireproof panel according to the present invention, and the fireproof siding plank A, the fireproof panel B, and the mounting tool E as shown in FIGS. The joint cover F may be used, or the mounting structure as shown in FIG. 19 may be used.

That is, FIGS. 8 (a) to 8 (f) show another embodiment of the fireproof siding plank A, and in particular, FIG. 8 (b) shows a ridge 31 for rain catching in the middle of the fixing piece 1. (C) and (d) are examples in which the gap between the rising pieces 2 is filled with the non-combustible sheet 4, (e) is an example in which the rising pieces 2 are formed of the non-combustible sheet 4, (f) The figure shows an example of a fireproof floorboard A formed by extrusion of the floorboard 3.

9 to 12 show another embodiment of the fixture E, in particular, FIG. 9 (c) shows an example in which the stabilizing piece 24 is formed from a soft fireproof packing material 32, and FIG. 9 (e). Is an embodiment of the fixture E in which the fireproof packing material 32 is interposed on the lower surface of the fixed portion 22 to improve the waterproofness and fireproofness of the joint portion G. 11 and 12 are perspective views showing an embodiment when the attachment E is formed in a short shape.

13 and 14 show another embodiment of the joint cover F. In particular, FIG. 14 (d) shows the waterproofness of the joint portion G by interposing a fireproof packing material 32 on the surface of the side wall decorative surface 28. 2 is an example of a joint cover F having improved fire resistance.

FIGS. 15 to 18 show another embodiment of the fireproof panel B. In particular, FIG. 15C shows an example in which the non-combustible board C is interposed also at the end of the core material 6 of the fireproof panel B, FIGS. 16A to 16D are examples of the fire-resistant panel B in which various decorative ribs are formed on the surface material 5 and the back surface material 7.

FIG. 17 is a partially cutaway sectional view of the refractory panel B. FIG. 17 (a) shows a side surface of the core material 6 of one or more of the surface material 5 or the back surface material 7 with an adhesive 33 interposed therebetween. An example of the fire-resistant panel B in which the nonwoven fabric 34 is adhered to improve the adhesive force between the core material 6 and the face material, and FIG. It is an example of a fireproof panel B in which short fibers 35 are planted through 33 to improve the adhesive force between the core material 6 and the face material.

FIG. 17 (c) shows the back surface side of the surface material 5 as shown in FIG.
It is an example of the fireproof panel B in which the breathable member 36 as shown in (a) to (c) is interposed. The breathable member 36 may be any breathable member that forms a very small gap in the plastic foam 15, for example, cotton, hemp, wool, silk, etc. (vegetable fiber, animal fiber, synthetic resin fiber). , Inorganic fibers, etc.) are thin and long stretched fibers and then twisted. More specifically, the extremely small gaps formed in the air permeable member 36 are the surplus gas components (chlorine, carbon dioxide, methylene chloride, formaldehyde, water vapor, hydrogen, etc.) in the plastic foam 15, or a gas such as condensed water during the reaction. Through which air can be ventilated, and the front surface and the back surface of the fire-resistant panel B after manufacturing are not deformed by internal gas such as swelling and warping, and the fire-resistant panel B is excellent in strength and fire resistance performance.

FIG. 19 is a mounting structure showing another example of the mounting structure of the fireproof panel according to the present invention.
(A) shows that the space between the side wall 9 of the fireproof panel B and the side wall decorative surface 28 of the joint cover F is filled with the fireproof packing material 32,
Example of structure with improved waterproofness and fire resistance, FIG. 19 (b)
Is filled with a fireproof packing material 32 between the fireproof panels B,
This is an example of a structure having improved waterproofness and fire resistance. Of course,
It is possible to provide a mounting structure in which each of these members is combined.

[0047]

As described above, according to the structure for mounting a fireproof panel according to the present invention, since the structure is such that both ends of the fireproof panel are fixed, workability is excellent. Since the fixing part of the fireproof panel by the fixing tool is completely covered by the joint cover, the head of the fixing tool is not exposed to the outside. Deformation at the time of fixing the fireproof panel is covered by the joint cover, so that no skill is required for construction. One-hour fireproof structure test (JIS-A-1304) of fireproof structure test with fireproof panel alone
Can pass. Compared to ceramic and cement-based fireproof panels, it is lighter in weight and dramatically improves workability. Workability is good because it can be stretched simultaneously in either direction. Since a groove is formed in the fixed part of the fireproof panel and the fixture is formed so as to be embedded in the groove so that the head of the fixture is embedded, the fireproof panel can be formed even if the fixture is formed in a long shape. The fixture can be fixed after fixing, and the workability can be surely achieved without any problem in the workability regardless of whether the fixture is long or short. If the breathable member is formed, the decorative surface of the fireproof panel will not be deformed such as swelling or warping for many years. When the piles are flocked, the core material is firmly bonded to the front surface material and the back surface material and is not peeled off. There are features and effects such as.

[Brief description of drawings]

FIG. 1 is a perspective view showing a mounting structure for a fireproof panel according to the present invention.

FIG. 2 is a sectional view showing a mounting structure for a fireproof panel according to the present invention.

FIG. 3 is an explanatory diagram showing an example of a fireproof seam board.

FIG. 4 is an explanatory diagram showing an example of a fireproof panel.

FIG. 5 is an explanatory diagram showing an example of a non-combustible board C.

FIG. 6 is an explanatory view showing an example of a fixture.

FIG. 7 is an explanatory diagram illustrating an example of a joint cover.

FIG. 8 is an explanatory view showing another embodiment of the fireproof seam board.

FIG. 9 is an explanatory view showing another embodiment of the fixture.

FIG. 10 is an explanatory view showing another embodiment of the attachment.

FIG. 11 is an explanatory view showing another embodiment of the fixture.

FIG. 12 is an explanatory view showing another embodiment of the fixture.

FIG. 13 is an explanatory view showing another embodiment of the joint cover.

FIG. 14 is an explanatory view showing another embodiment of the joint cover.

FIG. 15 is an explanatory view showing another embodiment of the fireproof panel.

FIG. 16 is an explanatory view showing another embodiment of the fireproof panel.

FIG. 17 is an explanatory view showing another embodiment of the fireproof panel.

FIG. 18 is an explanatory view showing the breathable member used in FIG. 17.

FIG. 19 is a cross-sectional view showing another embodiment of the fireproof panel mounting structure according to the present invention.

[Explanation of symbols]

α Frame β Fixing device β ₁ Head A Fireproof flooring board B Fireproof panel C Non-combustible board D Cover material E Fixture F Joint cover G Jointing part 1 Fixing piece 1a Tongue piece 2 Standing piece 3 Flooring board 4 Nonflammable sheet 5 Surface Material 6 Core material 7 Back material 8 Decorative surface 9 Side wall 10 Projecting piece 11 Groove 12 Guide part 13 Reinforcing piece 14 Extension piece 15 Plastic foam 16 Back decorative surface 17 Reinforcing piece 18 Extension piece 19 Male part 20 Female part 21 Insert Groove 22 Fixing part 22a Fixing hole 23 Locking part 24 Stabilizing piece 25 Stabilizing piece 26 Locking piece 27 Decorative surface part 28 Side wall decorative surface 29 Engaging piece 30 Engaging part 31 Protrusion 32 Fireproof packing material 33 Adhesive 34 Nonwoven fabric 35 Short Fiber 36 Breathable member

Claims (1)

[Claims] 1. A siding plate comprising a horizontal flat fixing piece and a rising piece projecting upward from a substantially central portion of the fixing piece,
A fireproof floorboard made of a non-combustible sheet formed on the floorboard,
A horizontal plane decorative surface, a side wall in which both ends of the decorative surface are bent inward, a projecting piece projecting outward at the tip of the side wall substantially parallel to the decorative surface, and a concave groove formed on the projecting piece. A surface member composed of a guide portion whose tip is bent inward and inclined, and a reinforcing piece whose tip is bent inward in an L-shape, a horizontal back surface, and a back surface. And a back material made of reinforcing pieces bent inward at both ends in a L shape. The reinforcing pieces of the surface material and the back material are overlapped with each other, and a convex male portion is provided at one end. In addition to forming a concave female part, and forming an insertion groove in which the male part and the female part are dented in a U shape, sandwiched by filling plastic foam inside. A fire-resistant panel, a horizontal fixing portion, a rising piece in which both end edges of the fixing portion are bent upward, and a tip of the rising piece. A fitting having a locking portion formed of a locking piece that is bent outward and protruding, a horizontal surface-shaped decorative surface portion, a side wall decorative surface in which both end edges of the decorative surface portion are bent downward, and a side wall decorative surface Equipped with a long joint cover with the tip bent inward and protruding from the engaging piece, and a long joint joint cover that is fixed to multiple cores at a fixed pitch. By inserting it between the plywood boards and fixing the groove at the end in the width direction to the base with a fixture, it is formed without gaps on all wall surfaces, and a noncombustible board is inserted in the insertion groove between the fireproof panels. The fixture is fixed linearly on the protruding piece between the fireproof panels by a fixture,
Further, the joint cover is integrally formed by fitting an engaging portion of the joint cover to a locking portion of the fixture.