Ceiling panel

Abstract

To provide a ceiling panel which can make a part of rotatably connecting a panel body to a connection object on a ceiling substrate side inconspicuous, and can suppress separation from a member fixed to the connection object on the ceiling substrate side with a simple structure.SOLUTION: A ceiling panel 1 includes a panel body 10, a panel side member 21 fixed to a rear face 10a side of a first end 11 in a first direction of the panel body, and a substrate side member 25 which is fixed to a connection object 2 on the ceiling substrate side, and rotatably holds the panel side member around an axis perpendicular to the first direction, wherein the substrate side member is provided with an engagement part 27 having a part which is folded back from the end of a part suspended toward the indoor side and extends toward the ceiling substrate side, and the panel side member is provided with an engaged part 23 having an engaged piece part 23b which is folded back from the end of a part raised in the panel's thickness direction, extends to the rear face so as to suppress separation of the engagement part by the rear face of the first end, and is engaged with the engagement part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a ceiling panel.

Background Art

[0002] Conventionally, a ceiling panel such as an inspection port panel whose one end is rotatably connected to a connection target has been known. For example, in Patent Document 1 below, an engaging piece is provided upward on a plate portion inside an outer frame, and an engaging piece that is rotatably engaged with the engaging piece of the outer frame from above is provided on a plate portion outside an inner frame that is provided in an opening surrounded by the outer frame so as to be openable and closable. An attachment structure for a ceiling inspection port is disclosed. In this attachment structure, a dropout prevention claw that hits the engaging piece of the inner frame is provided on a plate portion that stands up above the outer frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the structure described in Patent Document 1 above, it is necessary to provide a dropout prevention claw on the outer frame, and the plate portions provided with the engaging pieces of the outer frame and the inner frame are largely exposed on the indoor side, and further improvement is desired.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a ceiling panel that can make the part that rotatably connects the panel body to a connection target on the ceiling base side less conspicuous and can suppress detachment from a member fixed to the connection target on the ceiling base side with a simple structure.

Means for Solving the Problems

[0006] To achieve the above objective, the ceiling panel according to this disclosure comprises a panel body, a panel-side member fixed to the back side of the first end of the panel body in the first direction, and a base-side member fixed to a connecting target on the ceiling base side and rotatably holding the panel-side member around an axis perpendicular to the first direction, wherein the base-side member is provided with an engaging portion having a portion that is folded back from the end of a portion that hangs down toward the interior and extends toward the ceiling base side, and the panel-side member has a portion that is folded back from the end of a portion that rises in the panel thickness direction and extends toward the back side of the first end to Extend toward do An engaging portion having a locking piece is provided. The locking piece is locked to the engaging portion such that the portion of the engaging portion that is received in the receiving recess of the engaging portion is prevented from detaching by the back surface of the first end. It is characterized by the following. [Effects of the Invention]

[0007] The ceiling panel relating to this disclosure, with the configuration described above, makes the part that rotatably connects the panel body to the connecting target on the ceiling substrate side less conspicuous, and prevents detachment from the member fixed to the connecting target on the ceiling substrate side with a simple structure. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic, partially broken plan view showing an example of a ceiling panel according to one embodiment of the present disclosure in an installed state. [Figure 2] This is a schematic plan view with partial breakage showing the ceiling panel in its installed state. [Figure 3] (a) is a schematic longitudinal section of a partially fractured section corresponding to the view along the line X1-X1 in Figure 1, and (b) is a schematic longitudinal section of a partially fractured section corresponding to the view along the line X2-X2 in Figure 2. [Figure 4] (a) to (c) are schematic longitudinal cross-sectional views of a partial fracture, corresponding to Figures 3(a) and (b). [Figure 5] (a) is a schematic perspective view of a partially broken section of the ceiling panel, and (b) is a schematic plan view of a partially broken section of the ceiling panel. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described below with reference to the drawings. In some of the figures, some of the detailed symbols used in other figures have been omitted. In the following embodiments, directions such as the vertical direction will be described based on the state in which the ceiling panel according to this embodiment is installed. Figures 1 to 5 schematically show an example of a ceiling panel according to this embodiment.

[0010] As shown in Figures 3(a) and (b), the ceiling panel 1 according to this embodiment comprises a panel body 10 and a panel-side member 21 fixed to the back surface (the surface facing the ceiling substrate) 10a of the first end 11 in the first direction of the panel body 10. The ceiling panel 1 is fixed to the furring strip 2 that constitutes the connection target on the ceiling substrate side and includes a substrate-side member 25 that rotatably holds the panel-side member 21 around an axis perpendicular to the first direction. With this configuration, the ceiling panel 1 can be rotatably connected to the furring strip 2 by fixing the substrate-side member 25 to the furring strip 2. This allows the second end 12 (see Figure 1) in the first direction to be easily fixed to the furring strip 2 on the ceiling substrate side while the first end 11 in the first direction is rotatably connected to the ceiling substrate side. Furthermore, as in this example, the second end of the ceiling panel 1 can be detachably held to the furring strip 2 on the ceiling substrate side and function as an inspection hatch panel that opens and closes an inspection hatch 9 (see Figure 2).

[0011] The inspection opening 9 may be partitioned by multiple other ceiling panels 4, as shown in Figure 2. This inspection opening 9 is approximately rectangular in shape when viewed in the vertical direction (panel thickness direction), which is the opening direction. The inspection opening 9 is partitioned on all four sides by two ceiling panels 4,4 spaced apart in a first direction perpendicular to the vertical direction, and two ceiling panels 4,4 spaced apart in a second direction perpendicular to both the vertical and first directions. In other words, the inspection opening 9 is partitioned on all four sides by the edges of four ceiling panels 4,4,4,4. These ceiling panels 4 may be spaced apart in a first direction and their ends in the first direction may be fixed to elongated joists 2 extending in a second direction. Fixing parts 6 may be provided at both ends of these ceiling panels 4 in the first direction, which are fixed to the joists 2. These fixing parts 6 may be provided on elongated reinforcing brackets that extend over the entire length in the second direction to reinforce each end of the panel body of the ceiling panel 4 in the first direction. Elongated reinforcing brackets 5 may be provided at both ends of these ceiling panels 4 in the second direction, which extend over the entire length in the first direction to reinforce each end of the panel body of the ceiling panel 4 in the second direction.

[0012] The ceiling panels 4 that partition the inspection hatch 9 may be the same size as general ceiling panels. These ceiling panels 4 may, for example, have dimensions of approximately 0.3m to 1.0m in the first direction and approximately 1.2m to 2.4m in the second direction. In other words, these ceiling panels 4 may be elongated in the second direction. The illustrated example shows an example in which these ceiling panels 4 partition an elongated inspection hatch 9 in the first direction, but the size and shape of the inspection hatch 9 may be appropriate from the viewpoint of enabling inspection of the space above the ceiling and miniaturizing the inspection hatch 9 and the ceiling panel 1 that opens and closes it. The panel body of the ceiling panel 4 that partitions the inspection hatch 9 may have the same layered structure as the panel body 10 of the ceiling panel 1 that constitutes the inspection hatch panel. The configuration is not limited to partitioning the inspection hatch 9 with the ends of four ceiling panels 4 as described above, and various other configurations are also possible.

[0013] The furring strips 2 may be made of wood, but they may also be made of light steel and constitute a so-called light ceiling framing (steel ceiling framing). These furring strips 2 may be in the shape of a channel steel opening upward, or they may have lip portions formed to fold back at the upper ends of both side walls. Multiple furring strips 2 are arranged in parallel in the first direction at approximately equal intervals (approximately equal pitch) to form the ceiling framing structure. These furring strips 2 may also be supported by steel furring strip supports that are elongated in the first direction and arranged in parallel in the second direction at approximately equal intervals (approximately equal pitch). The steel ceiling framing may include furring strip joints that connect adjacent furring strips 2 in the longitudinal direction, and furring strip support joints that connect adjacent furring strip supports in the longitudinal direction. Furthermore, the steel ceiling substrate may include hangers for suspending and supporting the ceiling joist hangers, and suspension bolts that are inserted through holes in these hangers and secured with nuts.

[0014] The ceiling panel 1 and the other ceiling panel 4 that partition the inspection hatch 9 according to this embodiment may be installed as ceilings in relatively small buildings such as residences and offices, or as ceilings in various relatively large buildings such as gymnasiums, halls, shopping malls, factories, and schools. The panel body 10 of the ceiling panel 1 is roughly rectangular in shape when viewed from above (in the thickness direction). This panel body 10 is elongated in the first direction. The dimensions of this panel body 10 along the first direction and along the second direction are such that the inspection opening 9 can be closed, corresponding to the dimensions of the inspection opening 9 along the first direction and along the second direction. The thickness of this panel body 10 depends on the layer configuration, etc., but for example, it may be around 3.0 mm to 15.0 mm. The panel body 10 may be made of gypsum board, calcium silicate board, etc., but as shown in Figure 3, it is constructed to include a foamed resin or fiber core material 14. With this configuration, the weight can be reduced compared to a configuration in which the panel body 10 is made of wood-based board or gypsum board, etc.

[0015] Examples of the foamed resin core material 14 include those formed from resin compositions such as polyurethane resin, polystyrene resin, polyethylene resin, polypropylene resin, phenol resin, and epoxy resin. Examples of the fibrous core material 14 include those formed from mineral fibers such as glass wool and rock wool. In the illustrated example, the core material 14 is a foamed resin layer. This core material 14 occupies most of the panel body 10, and for example, the thickness may be about 80% to 99% of the thickness of the panel body 10. A surface layer 15 is provided on one side in the thickness direction on the indoor side of this core material 14, and a back surface layer 16 is provided on the other side in the thickness direction on the ceiling base side of the core material 14. The surface layer 15 is provided so as to continuously cover the end faces at both ends in the first direction of the core material 14 and the back surface layer 16 at each end in the first direction. These surface layer 15 and back surface layer 16 may contain a flame-retardant layer.

[0016] The flame-retardant layer as described above may be appropriately configured so as to satisfy the technical standards regarding the performance required for non-combustible materials etc. defined in the Building Standards Law. For example, the ceiling panel 1 may be configured to satisfy the standard of "flame-retardant material" in the technical standards, preferably, it may be configured to satisfy the standard of "semi-non-combustible material", and more preferably, it may be configured to satisfy the standard of "non-combustible material". For example, the flame-retardant layer may be a metal sheet such as a thin sheet-like foil-shaped aluminum sheet. A reinforcing layer containing reinforcing fibers such as glass fibers may be provided on the surface layer 15 and the back surface layer 16. The reinforcing layer may be a reinforcing fiber sheet such as a glass cloth, or a fiber-reinforced resin layer such as a glass fiber reinforced resin layer in which a resin is impregnated in the reinforcing fiber sheet. The surface (indoor side surface) of the surface layer 15 may also be a decorative surface to which an appropriate surface decoration treatment such as attaching a decorative sheet, printing, or painting has been performed.

[0017] The panel body 10 of the ceiling panel 1 is arranged such that a semi-transparent gap is formed between it and the panel bodies of other ceiling panels 4 adjacent in the first direction. As shown in Fig. 3(b), this gap may have an appropriate dimension so that the panel body 10 of the ceiling panel 1 does not interfere with the panel bodies of other ceiling panels 4 in a hanging state rotated approximately 90 degrees with respect to the field edge 2 constituting the ceiling base. At each end portion 13, 13 of the panel body 10 in the second direction, as shown in Figs. 1 and 5(a) and (b), reinforcing metal fittings 17, 17 having end-covering pieces covering the exposed end faces of the core material 14 are provided. These reinforcing metal fittings 17, 17 are elongated in the first direction of the panel body 10 and are provided over the entire first direction. These reinforcing metal fittings 17, 17 may be substantially U-shaped (channel-shaped) when viewed in the longitudinal direction so as to define receiving grooves for receiving each end portion 13, 13 of the panel body 10 in the second direction. That is, these reinforcing metal fittings 17, 17 may be provided with side pieces extending from both side edges in the panel thickness direction of the end-covering pieces toward the panel side and covering both surfaces in the thickness direction of each end portion 13, 13 of the panel body 10. In the illustrated example, an example is shown in which a plurality of long holes having a major diameter in the first direction are provided at intervals in the first direction in the side pieces on the ceiling base side of the reinforcing metal fittings 17, 17. The reinforcing metal fitting 5 of the ceiling panel 4 partitioning the inspection opening 9 described above may have the same configuration as the reinforcing metal fitting 17.

[0018] At the second end portion 12 of the panel body 10 in the first direction, a held piece portion 18 that is detachably held by the field edge 2 is provided. This held piece portion 18 is elongated in the second direction of the panel body 10 and is provided over the entire second direction, and constitutes a reinforcing metal fitting for reinforcing the second end portion 12 of the panel body 10. This held piece portion 18 is provided so as to extend outward in the first direction from the end face of the second end portion 12. This held piece portion 18 may be fixed to the field edge 2 so as to be partially overlapped with the fixing portion 6 of another ceiling panel 4 adjacent in the first direction. This held piece portion 18 may be fixed to the second end portion 12 via a fixing piece portion fixed along the back surface 10a of the second end portion 12 of the panel body 10. In the illustrated example, an example is shown in which a plurality of long holes having a major diameter in the second direction are provided at intervals in the second direction in the fixing piece portion. The retained piece 18 is detachably held by a retaining part 3 provided on the ceiling joist 2. The retaining part 3 may be a female threaded portion into which a screw is threaded through an insertion hole provided in the retained piece 18 that penetrates in the panel thickness direction. In the illustrated example, an example is shown in which an insertion hole for a screw is provided approximately in the center of the retained piece 18 in the second direction.

[0019] The retaining part 3 may be a so-called turn nut, in which a female threaded part is rotatably provided with a female screw hole into which the screw is screwed, and which is rotated by a screw inserted into an insertion part that is inserted through an insertion hole provided in the indoor side panel of the ceiling joist 2. With such a configuration, the female threaded part can be easily added to the ceiling joist 2 as an add-on. The retaining part 3 is not limited to a turn nut, but may also be an insert nut or a nut attached to the ceiling joist 2 by crimping or welding. Furthermore, the retaining part 3 that detachably holds the second end side of the ceiling panel 1 is not limited to a female threaded part into which the screw is screwed, but may also be a locking part that engages with a locking piece provided on the retained piece 18, or various other configurations may be used.

[0020] The retained piece 18 is provided with a temporary retaining portion 19 for temporarily holding the second end side of the ceiling panel 1 to the ceiling joist 2. The illustrated example shows an example in which temporary retaining portions 19, 19 are provided on both ends of the retained piece 18 in the second direction. These temporary retaining portions 19, 19 may be magnets that are attracted to the ceiling joist 2. The magnets constituting these temporary retaining portions 19, 19 may be configured to hold (temporarily retain) the ceiling panel 1 by attraction to the ceiling joist 2. Such magnets may be neodymium magnets, which have a relatively large magnetic force. The temporary holding portion 19 for temporarily securing the second end of the ceiling panel 1 to the ceiling joist 2 may be replaced with, or in addition to, such a magnet, a hook-and-loop fastener or adhesive material, or furthermore, the configuration may not have such a temporary holding portion 19 at all.

[0021] As shown in Figures 3 and 4, the panel-side member 21 fixed to the first end 11 of the panel body 10 and the base-side member 25 fixed to the ceiling joist 2 constitute a rotatable connecting member that rotatably connects the first end of the ceiling panel 1 to the ceiling joist 2. The substrate-side member 25 is provided with an engaging portion 27 having an extended portion 27b that is folded back from the end of a hanging portion 27a that forms a portion that hangs down toward the interior and extends toward the ceiling substrate side. The panel-side member 21 is provided with an engaged portion 23 having a rising portion 23a that forms a portion that rises in the panel thickness direction. This engaged portion 23 is folded back from the end of the rising portion 23a and extends toward the back surface 10 so as to prevent the engaging portion 27 from coming loose by contacting the back surface 10a of the first end portion 11, and has a locked portion 23b that is locked to the engaging portion 27. With this configuration, the ceiling panel 1 can be rotatably connected to the furring strip 2 by engaging the hook-shaped engaging portion 27 of the substrate-side member 25 with the hook-shaped engaged portion 23 of the panel-side member 21, improving productivity compared to hinges and the like. Furthermore, since the engaging portion 27 of the base material member 25 engages with the engaging portion 23, which is fixed to the back surface 10a side of the first end 11 of the panel body 10 and located on the back surface 10a side, these engaging portion 27 and engaging portion 23 become less conspicuous on the interior side. In addition, the detachment of the engaging portion 27 can be suppressed by the back surface 10a of the first end 11 of the panel body 10 and the locking piece 23b, thus simplifying the structure compared to a configuration in which a separate anti-detachment claw is provided.

[0022] The gap G between the tip 23c of the locking piece 23b and the back surface 10a of the first end 11 is smaller than the dimension W along the panel thickness direction of the portion of the engaging portion 27 that is received in the receiving recess 24 of the engaging portion 23 through this gap G. With this configuration, it is possible to effectively suppress the disengagement of the portion of the engaging portion 27 that is received in the receiving recess 24 of the engaging portion 23 through the gap G between the tip 23c of the locking piece 23b and the back surface 10a of the first end 11. The gap G between the tip 23c of the locking piece 23b and the back surface 10a of the first end 11, and the dimension T of the portion of the engaging portion 27 inserted into this gap G along the panel thickness direction, may be approximately the same dimension. With this configuration, the detachment of the engaging portion 27 received in the receiving recess 24 of the engaging portion 23 can be more effectively suppressed. Furthermore, since the portion of the engaging portion 27 inserted into the gap G between the tip 23c of the locking piece 23b and the back surface 10a of the first end 11 can be sandwiched between the tip 23c of the locking piece 23b and the back surface 10a of the first end 11, movement of the panel body 10 along the panel thickness direction relative to the engaging portion 27 can be suppressed.

[0023] When the panel body 10 is displaced between a horizontal state that constitutes the ceiling surface and an intermediate rotation state, as shown in Figures 3(a) and 4(a) and (b), the bottom 28a of the receiving recess 28 of the engaging portion 27 becomes a first rotational pivot point 7 that supports the tip 23c of the locked piece 23b. When the panel body 10 is displaced between an intermediate rotation state and a hanging state rotated approximately 90 degrees relative to the ceiling substrate, as shown in Figures 3(b) and 4(b) and (c), the tip 27c of the extended piece 27b of the engaging portion 27 becomes a second rotational pivot point 8 that supports the middle portion of the locked piece 23b. With this configuration, the engaging portion 27 and the engaged portion 23 are made hook-shaped as described above to suppress detachment from each other, while the panel body 10 can be rotated to approximately 90 degrees relative to the ceiling substrate. Here, approximately 90 degrees is not limited to 90 degrees, but may include 80 to 100 degrees. The hanging portion 27a of the engaging portion 27 is formed in an arc shape to suppress interference with the tip portion 23c of the locked portion 23b which rotates around the second pivot point 8. With this configuration, when the panel body 10 is displaced between a rotating state and a hanging state, the tip portion 23c of the locked portion 23b interferes with the hanging portion 27a of the engaging portion 27, which can cause abnormal noise or deformation of the engaging portion 27, thus enabling the panel body 10 to rotate smoothly.

[0024] Specifically, as shown in Figure 1, the panel-side member 21 is elongated in the second direction of the panel body 10 and is provided over substantially the entire length in the second direction, constituting a reinforcing fitting that reinforces the first end 11 of the panel body 10. With this configuration, reinforcing fittings (reinforcing fittings 17, 17, the retained piece 18, and the panel-side member 21) are provided at the four perimeter ends 11, 12, 13, 13 of the panel body 10, thereby reinforcing the four perimeter ends 11, 12, 13, 13 of the panel body 10. The panel-side member 21 is provided with a fixing piece 22 that is fixed along the back surface 10a of the first end 11 of the panel body 10. The fixing piece 22 is plate-shaped with its thickness direction being the same as the panel thickness direction. The fixing piece 22 is provided with a plurality of elongated holes that are spaced apart in the second direction and have a long axis in the second direction.

[0025] At the four corners of the panel body 10, there are fixing members 20,20,20,20 that fix the panel body 10 with the ends of the reinforcing brackets 17,17, the retained piece 18, and the panel side member 21 overlapping at the four corners (see also Figures 5(a) and (b)). These fixing members 20 may be fixed to the panel body 10 by fastening a fastener to a piece inserted into the layer of the panel body 10 at the point where the ends of the retained piece 18 and the panel side member 21 overlap with the ends of the reinforcing brackets 17,17, via a piece on the ceiling substrate side. In the illustrated example, the reinforcing brackets 5 and fixing parts 6 around the four perimeters of the ceiling panel 4 that partitions the inspection opening 9 are shown to be fixed to the panel body with similar fixing members. The reinforcing brackets 17,17, the fixing piece of the retained piece 18, and the fixing piece 22 of the panel side member 21 may be fixed to the panel body 10 with an appropriate adhesive or adhesive material in addition to the fixing members 20.

[0026] The engaged portion 23 is provided so as to be connected to the fixing piece portion 22 on the first outer side in the first direction. The engaged portion 23 is provided so as to be located inward in the first direction from the end face of the first end 11 of the panel body 10 (towards the first center in the horizontal state of the panel body 10) so that the engaging portion 27 that engages with it does not protrude outward in the first direction from the end face of the first end 11 of the panel body 10. The receiving recess 24 of the engaged portion 23 opens toward the back surface 10a of the panel body 10 and is provided in a groove shape along the entire length of the panel side member 21. As shown in Figure 3(a), the rising piece 23a constituting the engaged portion 23 is provided to rise from the first outer end of the fixing piece 22. This rising piece 23a is provided to rise substantially perpendicular to the back surface 10a of the panel body 10. The locking piece 23b constituting the engaged portion 23 is provided to extend from the upward-facing tip of the rising piece 23a toward the back surface 10a of the panel body 10 via a bent portion. The bent portion is formed in an arc shape that protrudes toward the ceiling substrate side. The locking piece 23b is provided in a slightly inclined shape so that it is slightly outward in the first direction as it approaches the back surface 10a of the panel body 10.

[0027] The gap G between the tip 23c of the locking piece 23b and the back surface 10a of the panel body 10, and the dimension T of the portion of the engaging piece 27 inserted into the gap G along the panel thickness direction, are not necessarily exactly the same dimension. The dimension T of the portion of the engaging piece 27 inserted into the gap G along the panel thickness direction may be understood as the thickness dimension of the piece constituting the engaging piece 27. In this case, the gap G and the dimension T of the portion of the engaging piece 27 inserted into the gap G along the panel thickness direction may include cases where the gap G is 1 to 2 times the thickness dimension of the piece constituting the engaging piece 27. Preferably, the gap G is such that, when the piece of the engaging piece 27 is inserted into the gap G, the tip 23c of the locking piece 23b and the back surface 10a of the panel body 10 come into contact with both sides of that piece. Furthermore, the gap G may be less than the thickness dimension of one side of the engaging portion 27 when one side of the engaging portion 27 is not inserted through the gap G. For example, when one side of the engaging portion 27 is not inserted through the gap G, the tip 23c of the locking portion 23b may be in close proximity to or in contact with the back surface 10a of the panel body 10.

[0028] As shown in Figures 1 and 5, the base-side member 25 is elongated in the second direction of the panel body 10 and is provided over substantially the entire length in the second direction. The base-side member 25 is provided with a fixing piece 26 that is fixed to the ceiling joist 2. As shown in Figure 3(a), the fixing piece 26 is plate-shaped with its thickness direction being the same as the panel thickness direction when the panel body 10 is in a horizontal position. The fixing piece 26 is provided so as to extend outward in the first direction on the ceiling base side of the first end 11 when the panel body 10 is in a horizontal position. The fixing piece 26 is provided with an insertion hole for a fastener that is fastened to the ceiling joist 2. The fixing piece 26 may be fixed to the ceiling joist 2 in such a way that it partially overlaps with the fixing piece 6 of another ceiling panel 4 adjacent in the first direction.

[0029] The engaging portion 27 is provided so as to be connected to the fixing piece portion 26 on the inside in the first direction. The receiving recess 28 that receives the locking piece portion 23b of the engaging portion 27 opens toward the ceiling substrate side and is provided in a groove shape along the entire length of the substrate side member 25. This receiving recess 28 is provided so as to open at an angle so as to be slightly inward in the first direction. The hanging piece 27a constituting the engaging portion 27 is provided so as to hang down from the first inner end of the fixing piece 26. This hanging piece 27a comprises an inclined portion that extends diagonally outward in the first direction relative to the fixing piece 26, and an arc-shaped portion that is connected to the lower side of the inclined portion and protrudes outward in the first direction. As shown in Figure 3(a), when the panel body 10 is in a horizontal position, the arc-shaped portion of the engaged portion 23 abuts against the inclined portion of the hanging piece 27a, thereby suppressing the outward movement of the panel-side member 21 in the first direction relative to the base-side member 25 (and the furring strip 2 to which it is fixed). The arc portion of the hanging piece 27a is formed such that the concave curved surface facing inward in the first direction abuts against or is close to the tip portion 23c of the locking piece 23b, which rotates around the second pivot point 8.

[0030] The extended piece 27b constituting the engaging portion 27 is bent relative to the downward-facing tip of the hanging piece 27a and is provided to extend diagonally inward in the first direction. The bent portion between the hanging piece 27a and the extended piece 27b becomes the bottom 28a of the receiving recess 28. This extended piece 27b is provided to be substantially parallel to the inclined portion of the hanging piece 27a. When the panel body 10 rotates between a horizontal state and a hanging state, this extended piece 27b is always located within the receiving recess 24 of the engaged portion 23. When the panel body 10 is in a horizontal position, the bent portion connected to the base end of the extended piece 27b is positioned to be sandwiched in the gap G between the tip 23c of the locking piece 23b of the engaged portion 23 and the back surface 10a of the panel body 10. Also, when the panel body 10 is in a horizontal position, the extended piece 27b is located within the receiving recess 24 of the engaged portion 23. In other words, when the panel body 10 is in a horizontal position, the dimension of the extended piece 27b along the panel thickness direction is equal to the dimension W of the portion of the engaged portion 27 within the receiving recess 24 of the engaged portion 23 along the panel thickness direction.

[0031] When the panel body 10 is in a hanging position, as shown in Figure 3(b), the boundary between the arc portion and the inclined portion of the hanging piece 27a is positioned to be sandwiched in the gap G between the tip portion 23c of the locking piece 23b of the engaged portion 23 and the back surface 10a of the panel body 10. Also, when the panel body 10 is in a hanging position, a portion of the arc portion of the extended piece 27b and the hanging piece 27a connected thereto is located within the receiving recess 24 of the engaged portion 23. In other words, the dimension of a portion of the arc portion of the extended piece 27b and the hanging piece 27a connected thereto along the panel thickness direction becomes the dimension W of the portion of the engaging portion 27 within the receiving recess 24 of the engaged portion 23 along the panel thickness direction. Furthermore, when the panel body 10 is in a hanging position, the tip portion 27c of the extended piece 27b abuts against the locking piece 23b of the engaged portion 23, and the bent portion connected to the base end of the extended piece 27b abuts against or comes close to the rising piece 23a of the engaged portion 23. This suppresses the vertical movement of the panel body 10 relative to the base member 25.

[0032] When the panel body 10 is rotated (opened) from a horizontal position (inspection hatch 9 closed), as shown in Figures 3(a) and 4(a) and (b), the locking piece 23b of the panel-side member 21 rotates around the first pivot point 7 of the base-side member 25. In the intermediate rotation state where the panel body 10 is half-open (in the example shown, rotated about 30 degrees from the horizontal position), the locking piece 23b of the panel-side member 21 aligns with the extended piece 27b of the base-side member 25. If the panel body 10 is rotated further from this state, as shown in Figures 4(c) and 3(b), the pivot point supporting the locking piece 23b shifts from the first pivot point 7 to the second pivot point 8, and the panel body 10 hangs down (inspection hatch 9 fully open). Conversely, when rotating (closing) the panel body 10 from a hanging position, as shown in Figures 3(b) and 4(c), the locking piece 23b of the panel-side member 21 rotates around the second pivot point 8 of the base-side member 25. As shown in Figures 4(b), 4(a), and 3(a), if the panel body 10 is rotated further from the intermediate rotation position, the pivot point supporting the locking piece 23b shifts from the second pivot point 8 to the first pivot point 7, and the panel body 10 becomes horizontal (inspection opening 9 closed).

[0033] The panel-side member 21 and the base-side member 25 configured as described above may be assembled by sliding the extended piece 27b of the base-side member 25 in the second direction through an opening on one side in the second direction of the receiving recess 24 of the panel-side member 21, which is fixed to the back surface 10a of the panel body 10. As shown in Figures 5(a) and (b), retaining portions 17a, 17a are provided on both ends in the second direction of the first end 11 of the panel body 10 to prevent the extended portion 27b of the base-side member 25, which is inserted into the receiving recess 24 of the panel-side member 21, from coming out in the second direction. In the illustrated example, the retaining portions 17a, 17a are shown as rising portions provided so as to rise up from the first end in the first direction of the reinforcing fittings 17, 17, but the example is not limited to this. The reinforcing fittings 17, 17 provided around the four sides of the panel body 10, the retained piece portion 18, and the panel side member 21 and the base side member 25 may each be formed in a continuous manner from an appropriate metal-based material by extrusion molding, pressing, bending, or the like.

[0034] In the example described above, an arc-shaped portion is provided on the hanging piece 27a of the engaging portion 27, but a configuration without such an arc-shaped portion is also possible. In the example described above, the pivot point supporting the locking piece 23b shifts between the first rotational pivot point 7 and the second rotational pivot point 8 when the panel body 10 rotates, but the example is not limited to this. In the example described above, both the panel-side member 21 and the base-side member 25 are provided over substantially the entire second direction of the panel body 10. However, one or both of these may be provided at multiple locations spaced apart in the second direction. In the example described above, the ceiling panel 1 is shown as an inspection panel in which the second end is detachably held to the joist 2, but it may also be a ceiling panel in which the second end is fixed to the joist 2 in a non-detachable manner. The configuration of each part of the ceiling panel 1 according to the above embodiment is not limited to the above-described form, and various other modifications are possible. [Explanation of symbols]

[0035] 1 Ceiling panel 7. First pivot point 8. Second pivot point 10 Panel Body 10a Reverse side 11 First end (first end in first direction) 21 Panel side member 23 Engaged portion 23a Rising section (part that rises in the direction of the panel thickness) 23b Locked piece 23c Tip 24 Receiving recess 25 Substrate side member 27 Engaging part 27a Hanging portion (the part that hangs down toward the interior) 27b Extended portion (part that extends toward the ceiling substrate) 27c Tip 28 Receiving recess 28a bottom 2. Ceiling joists (to be connected) G Gap between the tip of the locking piece and the back surface The dimension of the portion of the engaging part inserted into the gap T, along the panel thickness direction. W The dimension of the portion of the engaging part that is received in the receiving recess of the engaging part, along the panel thickness direction.

Claims

1. The system comprises a panel body, a panel-side member fixed to the back side of the first end of the panel body in the first direction, and a base-side member fixed to the connecting object on the ceiling base side, which rotatably holds the panel-side member around an axis perpendicular to the first direction. The ceiling panel is characterized in that the substrate-side member is provided with an engaging portion having a portion that is folded back from the end of a portion that hangs down toward the interior and extends toward the ceiling substrate side, and the panel-side member is provided with an engaging portion having a locking piece that is folded back from the end of a portion that rises in the panel thickness direction and extends toward the back surface of the first end, and the locking piece is locked to the engaging portion such that the detachment of the portion of the engaging portion that is received in the receiving recess of the engaging portion is suppressed by the back surface of the first end.

2. In claim 1, A ceiling panel characterized in that the gap between the tip of the locking piece and the back surface of the first end is smaller than the dimension along the panel thickness direction of the portion of the engaging part that is received in the receiving recess of the engaging part through the gap.

3. In claim 2, A ceiling panel characterized in that the gap between the tip of the locking piece and the back surface of the first end and the dimension of the portion of the engaging part inserted into the gap along the panel thickness direction are substantially the same.

4. In any one of claims 1 to 3, A ceiling panel characterized in that, when the panel body is displaced between a horizontal state that constitutes the ceiling surface and an intermediate rotation state, the bottom of the receiving recess that receives the locked piece of the engaging portion becomes a first pivot point that supports the tip of the locked piece, and when the panel body is displaced between the intermediate rotation state and a hanging state rotated approximately 90 degrees with respect to the ceiling substrate, the tip of the portion of the engaging portion that extends toward the ceiling substrate becomes a second pivot point that supports the middle portion of the locked piece.

5. In claim 4, The ceiling panel is characterized in that the portion of the engaging part that hangs down toward the interior side is formed in an arc shape to suppress interference with the tip of the locking piece that rotates around the second pivot point.

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