Fire-resisting ceiling inspection port

Abstract

To provide a fire-resisting ceiling inspection port that can be improved in fire resistance.SOLUTION: A fire-resisting ceiling inspection port 1 is provided at an opening o formed in a ceiling T. The ceiling T comprises a ceiling joist w. The fire-resisting ceiling inspection port 1 comprises an outer frame 2, an inner frame 3, a fire-resisting member 4, and a flame guide slope 5. The outer frame 2 is arranged at an edge of the opening o. The inner frame 3 is freely opened and closed relative to the outer frame 2. The fire-resisting member 4 is provided between the ceiling joist w and outer frame 2. The flame guide slopE 5 is located between the outer frame 2 and inner frame 3. The flame guide slope 5 is inclined to be located more inside perpendicularly upward. The flame guide slope 5 guides flames from below the ceiling T while weakening them.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fire-resistant ceiling access hatch. [Background technology]

[0002] A ceiling inspection hatch is described in Patent Document 1. The ceiling inspection hatch described in Patent Document 1 includes an outer frame provided in an opening in the ceiling, and an inner frame that opens and closes relative to the outer frame.

[0003] The ceiling inspection hatch described in Patent Document 1 has a small number of parts and allows the ceiling finishing panel to be attached to the inner frame with simple work. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-308981 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the ceiling inspection hatch described in Patent Document 1 can be easily installed, like regular ceiling inspection hatches, it does not have sufficient fire resistance. Therefore, in the event of a fire, the ceiling inspection hatch described in Patent Document 1 may fall off the ceiling.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a fire-resistant ceiling inspection hatch that can improve fire resistance. [Means for solving the problem]

[0007] A fire-resistant ceiling inspection hatch according to a first aspect of the present invention is provided in an opening formed in a ceiling. The ceiling has a joist. The fire-resistant ceiling inspection hatch comprises an outer frame, an inner frame, a fire-resistant member, and a flame guide ramp. The outer frame is positioned on the edge of the opening. The inner frame is openable and closable relative to the outer frame. The fire-resistant member is provided between the joist and the outer frame. The flame guide ramp is located between the outer frame and the inner frame. The flame guide ramp is inclined relative to the vertical so that the higher it is, the more inward it is positioned. The flame guide ramp guides flames from below the ceiling while weakening them. [Effects of the Invention]

[0008] The fire-resistant ceiling inspection hatch of the present invention can improve fire resistance. [Brief explanation of the drawings]

[0009] [Figure 1A] This is a perspective view of the fireproof ceiling inspection hatch in a closed state. [Figure 1B] This is a perspective view of the fireproof ceiling inspection hatch in an open state. [Figure 2A] 1B is a cross-sectional view corresponding to FIG. 1A, showing an enlarged view of the outer frame and the inner frame. [Figure 2B] FIG. 1C is a cross-sectional view corresponding to FIG. 1B, showing an enlarged view of the outer frame and the inner frame. [Figure 3] FIG. 2B is a cross-sectional view corresponding to FIG. 2A, showing a state in which a flame is generated from below the ceiling. [Figure 4] 4 is an enlarged cross-sectional view showing the vicinity of the flame guide ramp in FIG. 3 in a further enlarged manner. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0011] In the following description, terms indicating specific positions and directions may be used, but these terms are used for convenience to facilitate understanding of the contents of the embodiments and have no relation to the directions in which the embodiments are actually implemented.

[0012] The fire-resistant ceiling inspection hatch 1 according to this embodiment will be described with reference to Figures 1A, 1B, 2A, and 2B. Figure 1A is a perspective view of the fire-resistant ceiling inspection hatch 1 in a closed state. Figure 1B is a perspective view of the fire-resistant ceiling inspection hatch 1 in an open state. Figure 2A is a cross-sectional view corresponding to Figure 1A, showing an enlarged view of the outer frame 2 and inner frame 3. Figure 2B is a cross-sectional view corresponding to Figure 1B, showing an enlarged view of the outer frame 2 and inner frame 3.

[0013] As shown in Figures 1A and 1B, the ceiling T has a joist w. The joist w is made of a combustible material (for example, wood). As shown in Figure 1B, the ceiling T has an opening o. A fire-resistant ceiling inspection hatch 1 is provided in the opening o of the ceiling T. Hereinafter, the side closer to the center c of the opening o will be referred to as the "inside," and the side away from the center c of the opening o will be referred to as the "outside."

[0014] The fire-resistant ceiling inspection hatch 1 comprises an outer frame 2 and an inner frame 3. The outer frame 2 is disposed on the edge of the opening o. The inner frame 3 can be opened and closed relative to the outer frame 2.

[0015] As shown in FIG. 2A, the fire-resistant ceiling inspection hatch 1 further includes a fire-resistant member 4 and a flame guide ramp 5. The fire-resistant member 4 is provided between the joist w and the outer frame 2. The flame guide ramp 5 is located between the outer frame 2 and the inner frame 3. The flame guide ramp 5 is inclined relative to the vertical V so that the higher it is, the more inward it is positioned. The flame guide ramp 5 guides flames from below the ceiling T while weakening them.

[0016] Therefore, the flame is guided upwards by the flame guide ramp 5, weakening it as it moves inward. The guided flame also moves away from the joist w and is blocked by the fire-resistant material 4 between the joist w and the joist w. As a result, the fire-resistant ceiling inspection hatch 1 suppresses damage to the joist w due to heat, thereby improving fire resistance.

[0017] 2A and 2B, the flame guide ramp 5 is formed by closing the inner frame 3 against the outer frame 2. This makes it easy to adjust the flame guide ramp 5.

[0018] The fire-resistant ceiling inspection hatch 1 further includes a locking mechanism (not shown). The locking mechanism maintains the inner frame 3 closed relative to the outer frame 2. The locking mechanism is, for example, an opening / closing cam such as a coin lock.

[0019] Hereinafter, the details of the fire-resistant ceiling inspection hatch 1 will be described with reference to Figures 3 and 4. Figure 3 is a cross-sectional view corresponding to Figure 2A showing a state in which a flame is breaking out from below the ceiling T. Figure 4 is an enlarged cross-sectional view further enlarging the vicinity of the flame guide ramp 5 in Figure 3.

[0020] As shown in FIG. 3, the ceiling T further includes a ceiling board p. The upper surface of the ceiling board p and the lower surface of the rough joist w are in surface contact. The ceiling board p is made of a fire-resistant material. The fire-resistant material is a material that has fire resistance and fire prevention properties. An example of the fire-resistant material is reinforced gypsum board defined by the Japanese Industrial Standards (JIS). In other words, reinforced gypsum board is gypsum board mixed with inorganic fibers, etc.

[0021] The fire-resistant member 4 is made of the same fire-resistant material as the ceiling panel p. The underside of the fire-resistant member 4 and the upper surface of the ceiling panel p are in surface contact. Since the upper surface of the ceiling panel p is in surface contact with both the undersides of the fire-resistant member 4 and the joist w, the fire-resistant member 4 and the joist w are flush on their undersides. The upper surface of the fire-resistant member 4 is located higher than the upper surface of the joist w. Therefore, the fire-resistant ceiling inspection hatch 1 can further enhance its fire resistance because the fire-resistant member 4 further suppresses damage to the joist w caused by heat.

[0022] The horizontal thickness of the fire-resistant member 4 is preferably 9.5 mm, 12 mm, or 15 mm (each of which includes an error of ±10%). By making the horizontal thickness 9.5 mm, 12 mm, or 15 mm, the fire-resistant ceiling inspection hatch 1 can be made smaller while still improving its fire resistance.

[0023] The fire-resistant ceiling inspection hatch 1 further includes an inner board material 6. The inner board material 6 is disposed inside the area surrounded by the inner frame 3. The inner board material 6 is made of the same fire-resistant material as the ceiling panel p and the fire-resistant member 4.

[0024] The inner frame 3 has an inner bottom portion 31, an inner inclined portion 32, an inner vertical portion 33, and an outer top portion 34. The inner bottom portion 31 supports the inner board material 6. The inner inclined portion 32 is inclined so that it is positioned more inward as it moves upward from the outer end of the inner bottom portion 31. The inner vertical portion 33 extends upward from the upper end of the inner inclined portion 32. The outer top portion 34 protrudes outward from the upper end of the inner vertical portion 33.

[0025] The outer frame 2 has an outer bottom 21, an outer vertical portion 23, and an inner top portion 24. The outer bottom 21 is positioned to receive the ceiling panel p. The outer vertical portion 23 extends upward from the inner end of the outer bottom 21. The outer vertical portion 23 has through holes 28 for fixing to the fire-resistant member 4 and the joist w. The inner top portion 24 protrudes inward from the upper end of the outer vertical portion 23. The inner top portion 24 is located higher than the inner frame 3 when it is closed.

[0026] The outer frame 2 and the inner frame 3 are made of metal. The outer frame 2 and the inner frame 3 are preferably made of a metal having a melting point higher than that of aluminum. The outer frame 2 and the inner frame 3 are made of, for example, steel.

[0027] The fire-resistant ceiling inspection hatch 1 further includes an airtight material 7, a fixing screw 8, and a mounting member 9.

[0028] The airtight material 7 comprises, in order from the inside out, a first airtight material 71, a second airtight material 72, and a third airtight material 73. The first airtight material 71 is arranged between the inner bottom 31 of the inner frame 3 and the inner board material 6. The second airtight material 72 is arranged on the underside of the inner top portion 24 of the outer frame 2. The second airtight material 72 receives the outer top portion 34 of the inner frame 3 when the inner frame 3 is closed against the outer frame 2. The third airtight material 73 is arranged between the outer bottom 21 of the outer frame 2 and the ceiling board p.

[0029] The fixing screws 8 are attached to the joist w through the through holes 28 in the outer vertical portions 23 and the fire-resistant members 4. In other words, the fixing screws 8 fix the outer frame 2 to the joist w. The fixing screws 8 have, from the inside out, a head 81, a cylindrical portion 82, and a threaded portion 83. The head 81 is located on the inside of the outer vertical portions 23, the cylindrical portion 82 passes through the through holes 28, and the threaded portion 83 reaches the joist w.

[0030] As shown in Figure 4, the mounting member 9 is attached to the inner surface of the outer vertical portion 23 by a mounting pin 90. The mounting member 9 has, from bottom to top, an outer inclined portion 91, a curved horizontal portion 92, and a mounting portion 93. The outer inclined portion 91 is inclined so that it is positioned more inward as it goes upward. The outer inclined portion 91 forms a flame guide ramp 5 together with the inner inclined portion 32 of the inner frame 3. The curved horizontal portion 92 connects the outer inclined portion 91 and the mounting portion 93. The mounting portion 93 abuts against the outer vertical portion 23 of the outer frame 2. The mounting portion 93 and the outer vertical portion 23 have a mounting hole 99. The mounting pin 90 passes through the mounting hole 99.

[0031] The mounting member 9 is not limited to being attached to the outer frame 2, but may be attached to the inner frame 3, or may be attached to a location other than the outer frame 2 and the inner frame 3. The portion connecting the outer inclined portion 91 and the mounting portion 93 is not limited to the curved horizontal portion 92, but may be a member with a shape other than a curved shape, such as a bending member.

[0032] When the lower surface of the outer inclined portion 91 is referred to as the upper inclined surface 59 and the upper surface of the inner inclined portion 32 is referred to as the lower inclined surface 53, the flame guide ramp 5 is defined by the upper inclined surface 59 and the lower inclined surface 53. The upper inclined surface 59 and the lower inclined surface 53 are arranged with a space between them. The upper inclined surface 59 and the lower inclined surface 53 are parallel to each other.

[0033] Therefore, the flame guide ramp 5 is a parallel space, which further weakens the flame guided therethrough. As a result, the fire-resistant ceiling inspection hatch 1 further suppresses damage to the joist w due to heat, thereby further improving fire resistance.

[0034] The spacing between the upper and lower slopes 59, 53 is preferably less than 1.0 mm, more preferably less than 0.7 mm, and most preferably less than 0.5 mm, because the preferred spacing of the flame guide ramp 5 further attenuates the flame being guided therethrough.

[0035] The angle θ between the upper inclined surface 59 and the lower inclined surface 53 and the vertical V is preferably 20° or more and less than 45°, more preferably 25° or more and less than 40°, and most preferably 30° or more and less than 35°. This is because the flame guide ramp 5 has a preferred angle θ, which further weakens the flame guided therethrough.

[0036] The flame guide ramp 5 may be formed on one side of the opening o which constitutes the four sides in a plan view, or on all four sides (all around). Of course, it is preferable that the flame guide ramp 5 is formed on the entire periphery of the opening o, as this further weakens the guided flame. [Example]

[0037] The above-described fire-resistant ceiling inspection hatch 1 was specifically manufactured as an example, and a heating test was carried out for 60 minutes in accordance with the Japanese Industrial Standards (JIS).

[0038] The dimensions of the opening o formed in the ceiling T were a square of 606 mm x 606 mm. The heating area was a square of 800 mm x 800 mm concentric with the opening o.

[0039] The interior board material 6 and the ceiling board p are both made of reinforced gypsum board with a vertical thickness of 15 mm.

[0040] Reinforced gypsum board with a thickness of 15 mm in the left-right direction was used for the fire-resistant member 4. The height of the fire-resistant member 4 was 50 mm, and the height of the joist w was 30 mm. The joist w had a horizontal thickness of 40 mm.

[0041] The fixing screws 8 were stainless steel round wood screws (φ4.1×40). The number of fixing screws 8 was eight in total, with two on each side of the opening o.

[0042] The outer frame 2 and inner frame 3 were both made of steel. The distance between the upper inclined surface 59 and the lower inclined surface 53 of the flame guide ramp 5 was 1 mm. The angle θ formed between the upper inclined surface 59 and the lower inclined surface 53 and the vertical V was 33°. The flame guide ramp 5 was formed on all four sides (all around) of the opening o. The ratios of the dimensions of the outer frame 2 and inner frame 3 to the dimensions of the other components were the same as those shown in Figures 2A to 4.

[0043] As a result of the 60-minute heating test, the fire-resistant ceiling inspection hatch 1 according to the embodiment did not fall off from the rough joist w. The results of the heating test also showed that the fire-resistant ceiling inspection hatch 1 according to the embodiment had improved fire resistance.

[0044] The embodiments and examples of the present invention have been described above with reference to the drawings. However, the embodiments and examples are illustrative in all respects and are not limiting. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications equivalent to the claims and within the scope thereof. Of the configurations described in the embodiments and examples, those other than those described as the invention of the first aspect in "Means for Solving the Problems" are optional configurations and may be deleted or modified as appropriate.

[0045] In the above-described embodiment and examples, the flame guide ramp 5 has been described as a space. The flame guide ramp 5 may be a space into which a heat-resistant material is inserted. This is because the heat-resistant material weakens the guided flame. [Industrial Applicability]

[0046] The present invention provides a fire-resistant ceiling inspection hatch and has industrial applicability. [Explanation of symbols]

[0047] T ceiling w Noen о Opening 1 Fireproof ceiling inspection hatch 2 Outer frame 3 Inner frame 4. Fire-resistant materials 5. Flame Guide Ramp 59 Upper Slope 53 Lower Slope

Claims

1. A fire-resistant ceiling inspection hatch provided in an opening formed in a ceiling equipped with a rough frame, an outer frame disposed on the edge of the opening; an inner frame that can be opened and closed relative to the outer frame; A fire-resistant member provided between the siding and the outer frame; Between the outer frame and the inner frame, a flame guide ramp inclined so as to be positioned inward as it goes up relative to the vertical; Equipped with The flame guide ramp is a fire-resistant ceiling inspection hatch that guides flames from below the ceiling while weakening them.

2. 2. A fire-resistant ceiling inspection hatch as described in claim 1, wherein the upper surface of the fire-resistant member is located above the upper surface of the joist.

3. The flame guide ramp is defined by an upper slope and a lower slope arranged with a space between them, 3. The fire-resistant ceiling inspection hatch according to claim 1, wherein the upper slope and the lower slope are parallel to each other.

4. 3. The fire-resistant ceiling inspection hatch according to claim 1, wherein the flame guide ramp is formed around the entire periphery of the opening between the outer frame and the inner frame.

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