JP7727915B2 - Ceiling panels and how to remove them - Google Patents

Description

The present invention relates to a ceiling panel in which a first edge portion and a second edge portion located on both sides of the panel body in one direction are fixed to a ceiling substrate.

As shown in the conventional diagram (Figure 9) of Patent Document 1, a conventional ceiling panel has been proposed in which the fixing portions (flanges) provided on the edge of the panel body are overlapped between adjacent ceiling panels and fixed to the ceiling substrate with fasteners. Because this type of fixing structure involves overlapping flanges, the width of the joints between the panel bodies can be made small enough to be inconspicuous.

Japanese Patent Application Publication No. 5-272192

However, with the method described in the aforementioned document, when replacing a ceiling panel sandwiched between adjacent ceiling panels, not only the ceiling panel to be replaced but also the adjacent ceiling panels must be removed, which makes the work less efficient.

The present invention was proposed in consideration of these circumstances, and its purpose is to provide a ceiling panel and panel removal method that allows for a smaller joint width between ceiling panels and allows for efficient installation of ceiling panels and partial panel replacement.

In order to achieve the above-mentioned objective, the ceiling panel of the present invention has a flat panel body having a rectangular outer shape in a plan view, and a first edge portion and a second edge portion located on both sides of one direction of the panel body are fixed to a ceiling substrate, and the first edge portion of the panel body is provided with a first fixing portion that is fixed to the ceiling substrate by a fixing device along the longitudinal direction of the first edge portion, while the second edge portion of the panel body is provided with a second fixing portion that is fixed to the ceiling substrate by a fixing device along the longitudinal direction of the second edge portion. The ceiling panel is provided with a second fixing portion that is fixed to the ceiling panel, and the first fixing portion has a first protrusion whose back surface faces and is close to a portion of the second fixing portion of the adjacent ceiling panel, and a first recess that exposes a portion of the second fixing portion of the adjacent ceiling panel, while the second fixing portion has a second protrusion whose front surface faces and is close to the first protrusion of the adjacent ceiling panel and whose front surface can be exposed by the first recess of the adjacent ceiling panel, and a second recess that is blocked by the first protrusion of the adjacent ceiling panel.

The panel removal method of the present invention is a panel removal method for removing one ceiling panel from between the ceiling panel on the first edge side and the ceiling panel on the second edge side when multiple ceiling panels are attached to the ceiling substrate, and is characterized in that it includes loosening the fasteners of the first fixing portion of the ceiling panel adjacent to the second edge side of the ceiling panel to be removed, removing the fasteners of the second fixing portion of the ceiling panel to be removed, removing the fasteners of the first fixing portion of the ceiling panel to be removed, moving the first edge of the ceiling panel to be removed downward to tilt the ceiling panel, and sliding the ceiling panel diagonally downward.

Another panel removal method of the present invention is a panel removal method for removing one ceiling panel from between the ceiling panel on the first edge side and the ceiling panel on the second edge side when multiple ceiling panels are attached to the ceiling substrate, and is characterized by: detaching the fasteners of the second fixing portion of the ceiling panel to be removed; detaching the fasteners of the first fixing portion of the ceiling panel to be removed; moving the first edge portion of the ceiling panel to be removed downward to tilt the ceiling panel; and sliding the ceiling panel diagonally downward.

Furthermore, yet another panel removal method of the present invention is a panel removal method for removing one ceiling panel from between the ceiling panel on the first edge side and the ceiling panel on the second edge side when multiple ceiling panels are attached to the ceiling substrate, characterized in that the fasteners of the first fixing portion of the ceiling panel adjacent to the second edge side of the ceiling panel to be removed are loosened, the fasteners of the second fixing portion of the ceiling panel to be removed are loosened, the fasteners of the first fixing portion of the ceiling panel to be removed are removed, the first edge of the ceiling panel to be removed is moved downward to tilt the ceiling panel, and the ceiling panel is slid diagonally downward.

Furthermore, yet another panel removal method of the present invention is a panel removal method for removing one ceiling panel from between the ceiling panel on the first edge side and the ceiling panel on the second edge side when multiple ceiling panels are attached to the ceiling substrate, characterized in that the fasteners of the second fixing portion of the ceiling panel to be removed are loosened, the fasteners of the first fixing portion of the ceiling panel to be removed are removed, the first edge portion of the ceiling panel to be removed is moved downward to tilt the ceiling panel, and the ceiling panel is slid diagonally downward.

Because the ceiling panel of the present invention has the above-described configuration, the joint width between ceiling panels can be reduced, and installation of ceiling panels and partial panel replacement can be carried out efficiently.

Furthermore, because the panel removal method of the present invention follows the procedure described above, ceiling panels can be removed efficiently for partial replacement.

1 is a schematic bottom view of a separated state showing the manner in which panels of a ceiling panel according to one embodiment of the present invention are engaged with each other, and an enlarged partial bottom view of two locations. 1A and 1B are a schematic bottom view and an enlarged partial bottom view of two positions of the ceiling panel showing the engagement state between the panels of the ceiling panel. 1A is a schematic plan view of the ceiling panel in a separated state showing the manner in which the panels are engaged with each other, and FIG. 1B is an enlarged partial plan view of two locations. 3 is an enlarged longitudinal cross-sectional view corresponding to line AA in FIG. 1 (line BB in FIG. 3). 10A and 10B are schematic bottom views showing the procedure for attaching the ceiling panel. 10A and 10B are diagrams for explaining the procedure for removing the ceiling panel, in which (a) is a schematic bottom view of the ceiling panel to be removed, (b) is an enlarged view of part C in (a), and (c) is an enlarged view of part D in (a). 10A to 10C are schematic vertical cross-sectional views showing the procedure for removing the ceiling panel. 4 is an enlarged vertical cross-sectional view of a ceiling panel according to another embodiment of the present invention, corresponding to the line BB in FIG. 3. 10A to 10C are schematic vertical cross-sectional views showing the procedure for removing the ceiling panel. 10A and 10B are a schematic bottom view and an enlarged partial bottom view of a separated state showing the manner in which panels of ceiling panels according to yet another embodiment of the present invention are engaged with each other. 10A to 10C are schematic vertical cross-sectional views showing the procedure for removing the ceiling panel. 4 is an enlarged vertical cross-sectional view of a ceiling panel according to still another embodiment of the present invention, corresponding to the line BB in FIG. 3. 10A to 10C are schematic vertical cross-sectional views showing the procedure for removing the ceiling panel.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
First, the basic configuration of the ceiling panel 1 according to this embodiment will be described.

This ceiling panel 1 has a flat panel body 10 with a rectangular outer shape in a plan view, and a first edge portion 10a and a second edge portion 10b located on both sides of the panel body 10 in one direction are fixed to a ceiling substrate 70.

A first fixing portion 21 is provided on the first edge portion 10a of the panel body 10 along the longitudinal direction (side direction) of the first edge portion 10a. The first fixing portion 21 is fixed to the ceiling substrate 70 by a fastener 60. On the other hand, a second fixing portion 41 is provided on the second edge portion 10b of the panel body 10 along the longitudinal direction (side direction) of the second edge portion 10b. The second fixing portion 41 is fixed to the ceiling substrate 70 by a fastener 60.

The first fixing portion 21 comprises a first protrusion 22 whose back surface faces and is close to a portion of the second fixing portion 41 of the adjacent ceiling panel 1, and a first recess 23 that exposes a portion of the second fixing portion 41 of the adjacent ceiling panel 1. The second fixing portion 41 comprises a second protrusion 42 whose front surface faces and is close to the first protrusion 22 of the adjacent ceiling panel 1 and whose front surface can be exposed by the first recess 23 of the adjacent ceiling panel 1, and the second recess 43 that is blocked by the first protrusion 22 of the adjacent ceiling panel 1. Note that "facing and close" here means that surfaces are facing each other in a close proximity, and also includes opposing surfaces abutting each other.

Next, the details of the present ceiling panel 1 will be described with reference to Figures 1 to 4. In describing this embodiment, the up-down direction is defined based on the installed state of the ceiling panel 1. In other words, the surface of the ceiling panel 1 that is exposed to the indoor space below is the underside (bottom surface), and the back surface facing the ceiling substrate 70 is the top surface (flat surface).

Figure 1 is a schematic bottom view of the separated state showing the inter-panel engagement on the surface (underside) of ceiling panel 1, and an enlarged partial bottom view at two locations. Figure 2 is a schematic bottom view of the same engaged state and an enlarged partial bottom view at two locations. Figure 3 is a schematic plan view of the same separated state and an enlarged partial plan view at two locations. Figure 4 is an enlarged vertical cross-sectional view corresponding to A-A in Figure 1 (line B-B in Figure 3).

This ceiling panel 1 comprises a rectangular panel body 10, a first fixing piece 20 attached to the first edge 10a of the long side, a second fixing piece 40 attached to the second edge 10b of the other long side, and reinforcing pieces 65 attached to each of the short edge portions.

The first fixing piece 20, the second fixing piece 40, and the reinforcing piece 65 are all made of elongated metal material, for example, that runs along the edge and act as reinforcing members that suppress sagging and distortion of the edge of the panel main body 10 after installation. As detailed in Figure 4, the first fixing piece 20 and the second fixing piece 40 are each held and fixed by a holding piece (first holding piece 30, second holding piece 50) provided on the panel main body 10.

The retaining pieces, together with the fixing pieces, are components that maintain the strength of the ceiling panel 1. They may be made of metal, for example, but are provided with elongated holes or other lightening holes 38, 58 to reduce the overall weight of the ceiling panel 1 (see the enlarged view in Figure 3). Details of the first and second retaining pieces 30, 50 will be described later, along with an explanation of the longitudinal cross-sectional view shown in Figure 4.

The first edge 10a and second edge 10b, which are the two edge portions of the ceiling panel 1 in one direction, are arranged at corresponding positions on the ceiling substrate 70. In this embodiment, this ceiling substrate 70 is made up of multiple elongated rafters 70 arranged at equal intervals and parallel to one another. In other words, the first edge 10a and second edge 10b of the ceiling panel 1 are each fixed to the corresponding rafters 70 along their longitudinal direction.

The rafters 70 are channel steel as shown in Figure 4, and the ceiling panel 1 is attached below the rafters 70 so that it spans between the rafters 70. In other words, the short side dimension of the ceiling panel 1 corresponds to the dimension between the rafters 70, but the short side of the ceiling panel 1 may also correspond to three or more rafters 70.

The ceiling panel 1 may be fixed so that the first edge 10a and the second edge 10b are aligned perpendicular to the longitudinal direction of the joist 70. The ceiling panel 1 may also be attached to a ceiling substructure such as a T-bar instead of the joist 70.

Two adjacent ceiling panels 1 along the arrangement direction of the joists 70 are fixed to the underside of the joists 70 with fasteners 60 so that the protruding portions of the first and second fixing pieces 20, 40 that protrude outward from the panel body 10 overlap with portions of the second and first fixing pieces 40, 20 of the adjacent panels. This protruding portion serves as the first fixing portion 21 on the first fixing piece 20, and the second fixing portion 41 on the second fixing piece 40. Examples of fasteners 60 include screws such as point screws and nails.

The first fixing portion 21 has a plurality of discontinuous first protrusions 22 along the longitudinal direction of the first edge portion 10a, with first recesses 23 formed between the first protrusions 22. The second fixing portion 41 has a plurality of discontinuous second protrusions 42 along the longitudinal direction of the second edge portion 10b, with second recesses 43 formed between the second protrusions 42. As shown in Figure 1, the shapes of the protrusions of the first fixing portion 21 and the second fixing portion 41 differ from each other, and multiple types of protrusions are provided on each fixing portion.

The first protrusions 22 include two first protrusions (ends) 221 located at both longitudinal ends of the first edge portion 10a, with shorter first protrusions (short) 222 and longer first protrusions (long) 223 arranged alternately in the middle between them. The length of the first protrusions (ends) 221 is approximately half the length of the first protrusions (long) 223. In the illustrated example, the middle between the first protrusions (ends) 221 is arranged, in order from the end of the first edge portion 10a, with the first protrusions (short) 222, first protrusions (long) 223, first protrusions (short) 222, first protrusions (long) 223, and first protrusions (short) 222.

First elongated holes 22a extending perpendicular to the longitudinal direction of the first edge portion 10a are formed in one location on the first protrusion (end) 221, one location on the first protrusion (short) 222, and two locations on the first protrusion (long) 223. As shown in Figure 1, the first elongated holes 22a may be cutouts extending from the edge of the first protrusion 22 toward the panel body 10.

The first recesses 23 are formed between the first protrusions 22, and the lengths of the first recesses 23 along the longitudinal direction of the first edge portion 10a are approximately the same. These first recesses 23 are approximately isosceles trapezoidal openings between the first protrusions 22, with the portion cut out from the edge of the first fixing portion 21 (first protrusion 22) to the edge (edge) of the panel main body 10.

On the other hand, the second fixing portion 41 has two second protrusions (ends) 421 located on both ends of the second edge portion 10b and multiple second protrusions (long) 422 arranged in the middle between them, with second recesses 43 formed between the second protrusions 42. The second protrusions (long) 422 are approximately twice as long as the second protrusions (ends) 441 and are approximately the same length as each other. In the illustrated example, eight second protrusions (long) 422 are arranged in the middle between the two second protrusions (ends) 421.

The second protrusions (long) 422 include those with second elongated holes 42a extending along the longitudinal direction of the second edge portion 10b, and those without an opening such as an elongated hole. The second protrusions (end) 421 do not have elongated holes. In the illustrated example, the second protrusions (long) 422 are arranged in the following order from the end side of the second edge portion 10b: with elongated hole, with elongated hole, without elongated hole, with elongated hole, with elongated hole, without elongated hole, with elongated hole, with elongated hole.

The second recesses 43 are formed between the second protrusions 42, and the lengths of the second recesses 43 along the longitudinal direction of the second edge portion 10b are approximately the same. These second recesses 43 are approximately isosceles trapezoidal openings between the second protrusions 42, with a notch extending from the edge of the second fixing portion 41 (second protrusions 42) to the edge (edge) of the panel main body 10.

These two types of first fixing portions 21 and second fixing portions 41 are arranged such that, between adjacent ceiling panels 1, the portion where the first elongated hole 22a of the first protrusion 22 is formed corresponds to the second recess 43 of the adjacent panel, and the portion where the second elongated hole 42a of the second protrusion 42 is formed corresponds to the first recess 23 of the adjacent panel. Furthermore, a portion of the portion where the first elongated hole 22a of the first protrusion 22 is not formed corresponds to a portion of the portion where the second elongated hole 42a of the second protrusion 42 is not formed. In other words, between two adjacent ceiling panels 1 after installation, the second fixing portions 41 and the first fixing portions 21 are arranged in an up-down relationship, but due to the recesses, i.e., the fasteners, there are portions where they do not overlap.

The first fixing portion 21 and the second fixing portion 41 are engaged to overlap and are fixed to the joist 70. More specifically, the first fixing portion 21 is arranged below so as to overlap the surface (lower surface) of the second fixing portion 41. As a result, as shown in Figures 1 to 3, the second protrusion 42 and the first protrusion 22 partially overlap vertically, with the portion with the first elongated hole 22a overlapping the second recess 43 and the portion with the second elongated hole 42a overlapping the first recess 23.

In other words, there is no second fixing piece 40 above the first elongated hole 22a, and there is no first fixing piece 20 below the second elongated hole 42a. In other words, the first fixing portion 21 and the second fixing portion 41 overlap between two adjacent ceiling panels 1, but the fastener 60 is attached to the joist 70 via the fixing portion of one of the panels.

Note that the view shown in Figure 4 is an enlarged vertical cross-sectional view taken along line B-B in Figure 3 (corresponding to line A-A in Figure 1), and as shown in Figure 4, at the position of line B-B, the second protrusion 42 and the first protrusion 22 are closely stacked one on top of the other.

Next, the detailed configuration of the first fixed piece 20 and the second fixed piece 40, and the manner in which the first fixed piece 20 and the second fixed piece 40 are fixed to the panel main body 10, will be described with reference to the enlarged vertical cross-sectional view of Figure 4.

The panel body 10 comprises a substrate 11, a surface layer 12 provided on the surface side of the substrate 11, and a back layer 13 provided on the back side of the substrate. The substrate 11 is made of, for example, a foamed resin or fiber material, as shown in Figure 4.

The first fixing piece 20 is held and fixed by a first holding piece 30 provided on the panel body 10. This first holding piece 30 comprises a first base portion 31 fixed to the back surface of the panel body 10, and a first fitting piece portion 32 formed to extend toward the edge beyond the first base portion 31 and curve and bulge. The first base portion 31 is fixed to the panel body 10 by a connecting member 34.

The first fixed piece 20 comprises a first fixed portion 21, a first base portion 25 extending inward (toward the panel body 10) from the first fixed portion 21 in a flat plate-like shape, and a first inclined piece portion 26 extending from the first base portion 25 at a downward incline toward the rear surface of the panel body 10. The first fixed piece 20 further comprises a first upright piece portion 24 extending from the boundary between the first fixed portion 21 and the first base portion 25 toward the rear surface of the panel body 10 in a direction perpendicular to the first base portion 25. Two ribs 25a are formed on the upper surface of the first base portion 25.

A space is formed between the first upright piece 24, the first base 25, and the first inclined piece 26, and this space serves as the first mating recess 27 into which the first mating piece 32 of the first holding piece 30 fits.

With the first fitting recess 27 of the first fixing piece 20 fitted into the first fitting piece 32 of the first holding piece 30, the lower end of the first upright piece 24 abuts against the rear surface of the panel body 10, and the inner surface of the first inclined piece 26 closely overlaps the outer surface of the flat portion of the first fitting piece 32. In this state, the first inclined piece 26 and the flat portion of the first fitting piece 32 are fixed together with the fixing device 36, whereby the first fixing piece 20 is fixed to the panel body 10 so that the first fixing portion and the first base 25 are parallel to the panel body 10.
The second fixed piece 40 is fixed in a manner similar to that of the first fixed piece 20 .

The second fixing piece 40 is held and fixed by a second holding piece 50 provided on the panel body 10. This second holding piece 50 comprises a second base portion 51 fixed to the back surface of the panel body 10, and a second fitting piece portion 52 formed to extend further toward the edge than the second base portion 51 and curve and bulge. The second base portion 51 is fixed to the panel body 10 by a connecting member 54.

The second fixed piece 40 comprises a second fixed portion 41, a second base portion 45 that extends inward (toward the panel body 10) from the base end of the second fixed portion 41 via a step (at the lower step) in a flat plate-like shape, and a second inclined piece portion 46 that extends downwardly from the second base portion 45 toward the back surface of the panel body 10. The second fixed piece 40 further comprises a second upright piece portion 44 that extends from the boundary between the second fixed portion 41 and the second base portion 45 toward the back surface of the panel body 10 in a direction perpendicular to the second base portion 45. A single rib 45a is formed on the upper surface of the second base portion 45.

A space is formed surrounded by the second upright piece 44, the second base 45, and the second inclined piece 46, and this space serves as the second mating recess 47 into which the second mating piece 52 of the second holding piece 50 fits.

When the second fitting recess 47 of the second fixing piece 40 is fitted into the second fitting piece 52 of the second holding piece 50, the lower end of the second upright piece 44 abuts against the back surface of the panel main body 10, and the inner surface of the second inclined piece 46 closely overlaps the outer surface of the flat portion of the second fitting piece 52. In this state, the second inclined piece 46 and the flat portion of the second fitting piece 52 are fixed together with the fixing device 56, and the second fixing piece 40 is fixed to the panel main body 10 so that the second fixing piece 41 and second base 45 are parallel to the panel main body 10.

As mentioned above, the ceiling panel 1 has a fixed structure in which the first fixing portion 21 is arranged between adjacent ceiling panels 1 so as to overlap the underside of the second fixing portion 41 of the adjacent ceiling panel 1. Therefore, the first and second fixing pieces 20, 40 are formed such that the second fixing portion 41 is positioned higher than the first fixing portion 21 by a step, as explained in Figure 4.

The siding 70 to which the ceiling panel 1 is attached comprises a base portion 71 and side plate portions 74 rising from both widthwise ends of the base portion 71. The base portion 71 has two reinforcing ribs 73 in the longitudinal direction, with a plate-shaped central base portion 72 between them. The second and first fixing portions 41, 21 of two adjacent ceiling panels 1, which overlap one another above the other, are fixed to this central base portion 72 with fasteners 60.

As explained in Figures 1 to 4, the ceiling panel 1 is attached to the joist 70 so that its fixed portion overlaps the fixed portion of the adjacent ceiling panel 1. Therefore, the joint width between the ceiling panels 1 (panel body 10) corresponds to the width dimension of one fixed portion, so the joint width dimension does not become too large, and it is possible to avoid the aesthetic appearance being impaired by the joints.

In addition, in this embodiment, the first fixing portion 21 has a first recess 23, and the second fixing portion 41 has a second recess 43. However, due to the overlapping of the two fixing portions, a protrusion exists above or below the recess. As a result, the surface (underside) of the joist 70 is not exposed due to the presence of the recess, and the joist 70 is covered by one or two protrusions. This prevents the surface color of the joist 70, such as its metallic color, from blending with the surface color of the fixing portion and becoming exposed to the outside.

Furthermore, the fixing pieces (first fixing piece 20, second fixing piece 40) have a stepped (protruding rearward) cross section as shown in Figure 4, and are positioned further back than the rear surface of the panel body 10, so the boundary between the first fixing piece 21 and the second fixing piece 41 and the fastener 60 are not individually noticeable. Note that the decorative surfaces may be a dark color such as black to make the surfaces (undersides) of the first fixing piece 21 and the second fixing piece 41 less noticeable.

Furthermore, each ceiling panel 1 is arranged so that the first fixing portion 21 supports the second fixing portion 41 of the adjacent panel from below, and the second fixing portion 41 is supported from below by the first fixing portion 21 of the other adjacent panel. As a result, the dependency between adjacent ceiling panels 1 is approximately the same for all ceiling panels 1, preventing only some ceiling panels 1 from becoming easily displaced downward.

Furthermore, the first fixing portion 21 and the second fixing portion 41 are each individually fixed to the joist 70 with fasteners 60, so that each ceiling panel 1 is securely attached to the joist 70. In other words, between ceiling panels 1, not only the lower first fixing portion 21 but also the second fixing portion 41 are fixed to the joist 70 with fasteners 60, ensuring robust installation of the ceiling panels 1.

In addition, in this embodiment, multiple pairs of first protrusions 22 and first recesses 23 are provided alternately on the first edge portion 10a, and multiple pairs of second protrusions 42 and second recesses 43 are provided on the second edge portion 10b, thereby ensuring secure and firm attachment of the ceiling panel 1 to the sill 70.

Furthermore, in this embodiment, a second recess 43 is formed at the location where the first protrusion 22 is fixed to the soffit 70 using the fastener 60, and a first recess 23 is formed at the location where the second protrusion 42 is fixed to the soffit 70 using the fastener 60. As a result, there is no need to provide one through-hole for the fastener 60 on each side of the fixing portion, corresponding to the same longitudinal position on the edge portion. This eliminates the need for position (hole) alignment, allowing for efficient installation.

In other words, the second recess 43 in the second fixing portion 41 acts as a clearance hole for fastening the first protrusion 22 of the first fixing portion 21 of the adjacent panel with the fastener 60. Meanwhile, the first recess 23 of the first fixing portion 21 acts as a recess for avoiding contact with the head of the fastener 60 attached to the second protrusion 42 of the second fixing portion 41 of the adjacent panel. Note that in this embodiment, the first recess 23 and the second recess 43 are both notched recesses, but the first recess 23 may be a hole large enough to avoid contact with the head of the fastener 60, and the second recess 43 may be a hole large enough to allow the fastener 60 to pass through.

As such, the first fixing portion 21 and the second fixing portion 41 of the adjacent panel have a mixture of overlapping and non-overlapping portions, and the balance between these depends on the number of portions to be fastened using the fasteners 60. Increasing the number of fastening portions using the fasteners 60 increases the individual fastening strength of each ceiling panel 1, but the overlapping area becomes smaller, reducing the degree of dependency on adjacent panels. Conversely, reducing the number of fastening portions using the fasteners 60 decreases the individual fastening strength of each ceiling panel 1, but the overlapping area becomes larger, increasing the degree of dependency on adjacent panels.

For example, in this embodiment, a second elongated hole 42a may be formed in the second protrusion (long) 422 (see Figure 1) where no second elongated hole 42a is formed, and a new first recess 23 may be provided in the middle of the first protrusion (long) 223 at a corresponding position. In this way, the number of fastening locations using the fastener 60 increases, but the overlapping area between the first fixing portion 21 and the second fixing portion 41 of the adjacent panel decreases, reducing the degree of dependency between them.

As described above, the first fixing portion 21 and the second fixing portion 41 have not only protrusions but also recesses, which provides various benefits, such as improved installation efficiency through fastening with fasteners 60. In particular, providing the first recess 23 and second recess 43, which are cutout-shaped and significantly larger than the screw insertion holes, also contributes to reducing the weight of the ceiling panel 1.

Figures 5(a) and 5(b) are schematic bottom views showing the procedure for installing ceiling panels 1. Adjacent ceiling panels 1 are installed so that the second fixing portion 41 abuts against the base portion 71 of the joist 70, and the first fixing portion 21 abuts against the second fixing portion 41. The fasteners 60 are attached to the first and second protrusions 22, 42, respectively, in positions where the protrusions do not overlap. In this way, the ceiling panels 1 can be installed one by one in order. In the example of Figures 1 to 3, the ceiling panels 1 can be installed in the order left, then right.

First, place the first fixing portion 21 of the ceiling panel 1 to be attached underneath the second fixing portion 41 of the previously fixed ceiling panel 1, and temporarily fix it by passing the fastener 60 through the first elongated hole 22a of the first protrusion 22 (see part X1 in Figure 5(a)).

Next, the second fixing portion 41 of the ceiling panel 1 to be attached is aligned with the second elongated hole 42a of the second protrusion 42 on the base portion 71 of the joist 70, and the second fixing portion 41 is permanently fixed to the joist 70 using the fastener 60 (see part X2 in Figure 5(b)). In this case, because the first fixing portion 21 is temporarily fixed, fine adjustments can be made to the ceiling panel 1 in the direction of alignment with the joist 70 before the second fixing portion 41 is permanently fixed to the joist 70.

Figure 5(b) shows a state in which, due to fine adjustment, the first fixing portion 21 is slightly misaligned with the second fixing portion 41 of the already fixed ceiling panel 1. Once the position is determined, the fastener 60 is properly fixed in that state (see part X3 in Figure 5(b)). In this way, the first fixing portion 21 is fixed even if it is slightly misaligned with the second fixing portion 41 of the adjacent ceiling panel 1, but the first protrusion 22 is partially overlapping the second protrusion 42 of the adjacent ceiling panel 1 (see Figure 5(b)).
In this way, the multiple ceiling panels 1 are attached to the joists 70 one by one in order.

Next, we will explain how to remove a ceiling panel 1 sandwiched between adjacent ceiling panels 1 for purposes such as partial replacement, with reference to Figures 6 and 7. Figure 6(a) is a schematic bottom view including the ceiling panel 1 to be removed, (b) is an enlarged view of section C in (a), and (c) is an enlarged view of section D in (a). Figures 7(a) to (c) are schematic vertical cross-sectional views showing the procedure for removing the same ceiling panel 1.

First, loosen the fasteners 60 attached to the first elongated holes 22a of all of the first protrusions 22 of the first fixing portion 21 of the ceiling panel 1 adjacent to the second edge portion 10b of the ceiling panel 1 to be removed (see Figures 6(a) and (b) and part Y1 in Figure 7(a)). This creates a space S.

Next, the fasteners 60 attached to the second elongated holes 42a of all second projections 42 of the second fixing portions 41 located on the second edge portion 10b of the ceiling panel 1 to be removed are removed (see Figures 6(a) and (c) and part Y2 in Figure 7(b)). When all the fasteners 60 for the second projections 42 have been removed in this manner, the second projections 42 of the ceiling panel 1 to be removed are detached from the sill 70. However, the second projections 42 are positioned in the space S created between the sill 70 and the first projections 22 of the adjacent panel, which are now hanging down due to the loosening of the fasteners 60, and are held by the first projections 22 from below (see Figure 7(b)).

Next, remove the fasteners 60 attached to the first elongated holes 22a of all first protrusions 22 of the first fixing portion 21 located on the first edge portion 10a of the ceiling panel 1 to be removed (see Figures 6(a) and (b) and part Y3 in Figure 7(b)).

When all of the fasteners 60 on the first protrusion 22 are removed in this way, the first fixing portion 21 of the ceiling panel 1 to be removed comes off the sill 70. Because the first fixing portion 21 is located below the second fixing portion 41 of the ceiling panel 1 adjacent to the first edge portion 10a, the first edge portion 10a of the ceiling panel 1 to be removed becomes movable downward.

Then, the first edge portion 10a of the ceiling panel 1 to be removed is moved downward to tilt the ceiling panel 1, and the ceiling panel 1 can be removed by sliding it diagonally downward (see Figure 7(c)).

The above panel removal method can be summarized as follows:
Loosen the fastener 60 of the first fixing portion 21 of the ceiling panel 1 adjacent to the second edge portion 10b side of the ceiling panel 1 to be removed.
Remove the fasteners 60 from the second fixing portions 41 of the ceiling panel 1 to be removed.
Remove the fasteners 60 from the first fixing portions 21 of the ceiling panel 1 to be removed.
The first edge portion 10a of the ceiling panel 1 to be removed is moved downward to tilt the ceiling panel 1, and the ceiling panel 1 is then slid diagonally downward.

As such, because this ceiling panel 1 has an overlapping engagement structure as described above in relation to adjacent ceiling panels 1, it can be easily removed without having to remove the adjacent ceiling panels 1 on either side.

More specifically, although the second fixing portion 41 and first fixing portion 21 of adjacent panels partially overlap vertically, the second protrusion 42 and first protrusion 22 are individually fixed to the joist 70 with fasteners 60. Therefore, when removing one ceiling panel 1, it is sufficient to remove only the fasteners 60 of that ceiling panel 1.

Since the adjacent ceiling panels 1 are individually secured with fasteners 60, removing the ceiling panel 1 to be removed will have little effect on the adjacent ceiling panels 1. As explained in Figures 6 and 7, it is only necessary to loosen the fasteners 60 for the first securing portion 21 of the ceiling panel 1 adjacent to the second edge portion 10b, and there is no need to loosen the fasteners 60 for the second securing portion 41 of the ceiling panel 1 adjacent to the first edge portion 10a.

To install a new ceiling panel 1 in the same location as the one removed in this manner, simply reverse the removal procedure described above in Figures 6 and 7.

Specifically, first, tilt the ceiling panel 1 to be attached, and insert its second fixing portion 41 into the space S created between the first fixing portion 21 of the adjacent ceiling panel 1 on the second edge portion 10b side and the joist 70.

Next, the first fixing portion 21 of the ceiling panel 1 to be attached is attached to the joist 70 using the fastener 60, and then the second fixing portion 41 is also attached to the joist 70 using the fastener 60.

Then, the first fixing portion 21 of the ceiling panel 1 adjacent to the second edge portion 10b of the ceiling panel 1 to be attached, whose fastener 60 was loosened when the ceiling panel 1 was removed, is permanently fixed to the joist 70.

In this way, when replacing a ceiling panel 1, installing a new one can be done easily and efficiently.

When replacing a ceiling panel 1 like this, it is desirable to attach the fastener 60 to the second fixing portion 41 of the new ceiling panel 1 at a different position in the second elongated hole 42a than the removed ceiling panel 1, i.e., at a different position on the joist 70. This avoids attaching the fastener 60 to an existing hole in the joist 70, thereby preventing the ceiling panel 1 from shifting or falling.

Furthermore, the first fixing portion 21 may be provided with a mixture of a first elongated hole 22a, which allows for fine adjustment, and a long elongated hole (third elongated hole) (not shown) that extends along the edge, similar to the second elongated hole 42a.

By doing this, as with the second fixing portion 41, when replacing the ceiling panel 1 with a new one, it is possible to avoid attaching the fastener 60 to the hole in the existing sill 70, even in the first edge portion 10a. In cases where such a third elongated hole is provided, the fastener 60 can be attached to the third elongated hole when the fastener 60 is finally attached to the first elongated hole 22a (X3 in Figure 5(b)).

The first protrusion 22 may also be provided with multiple first elongated holes 22a, including a spare first elongated hole 22a, for fastening a new replacement ceiling panel 1 with a fastener 60.

In this way, by providing the first fixing part 21 with a third elongated hole and a spare first elongated hole 22a, it is possible to avoid attaching the fastener 60 to an existing hole in the sill 70, just as with the second fixing part 41.

In this embodiment, the fastener insertion holes provided in the first protrusion 22 and the second protrusion 42 are elongated holes (first elongated hole 22a, second elongated hole 42a) that allow for fine adjustments and changes to the insertion position, but this is not limited to this and they may also be round holes that do not allow for fine adjustments or changes to the insertion position.

In the embodiment illustrated in Figures 1 to 7, when the ceiling panel 1 is installed, the first protrusion 22 and the second protrusion 42 abut and no gap is formed between the first fixing portion 21 and the second fixing portion 41, but a small gap (clearance) may also be formed. For example, the ceiling panel 1 may have a longitudinal cross section as shown in Figure 8. The longitudinal cross section of Figure 8 corresponds to line B-B in Figure 3.

The ceiling panel 1 shown in Figure 8 differs from that shown in Figure 4 in terms of the shape of the first fixing piece 20 and second fixing piece 40, particularly in the vertical cross-sectional shape. Note that the planar shape, specifically the planar positions and number of the first protrusion 22, first elongated hole 22a, first recess 23, second protrusion 42, second elongated hole 42a, and second recess 43, are the same as those shown in Figures 1 to 3, so bottom and plan views are omitted.

In the example shown in Figure 8, the shape of the first base 25, including the rib strip 25a, on the panel body 10 side of the first fixing portion 21 of the first fixing piece 20 differs from that shown in Figure 4. Two protrusions 25b, 25c are formed on the first base 25, and the ceiling panel 1 is attached so that both of these abut against the underside of the base portion 71 of the joist 70. These protrusions 25b, 25c also function as rib strips.

When the ceiling panel 1 is installed, these protrusions 25b, 25c abut against the underside of the base portion 71 of the joist 70, avoiding the recessed ridges on the back side created by the reinforcing ribs 73 of the base portion 71. Because the first fixing portion 21 (first protrusion 22) is not positioned to abut against the second fixing portion 41 of the adjacent panel, for a more stable arrangement, it is desirable to provide two protrusions 25b, 25c, as shown in the illustration, and install them wider than the width of the joist 70. Note that in the illustration, the protrusion 25b on the first inclined piece 26 side is wider than the protrusion 25c on the first fixing portion 21 side.

Alternatively, instead of being separated like protrusions 25b and 25c, a single protrusion may be provided, meaning that the first base 25 may be thick enough to include the thickness of protrusions 25b and 25c. Furthermore, protrusions 25b and 25c may abut against the bottom surface of the recessed strip on the back side of the reinforcing rib 73 or fit into the recessed strip.

Furthermore, the first fixing portion 21 is not formed at the same height level as the first base portion 25. Rather, it is formed slightly lower than the first base portion 25, with a step formed via the protruding portion 25c on the first fixing portion 21 side. As shown in Figure 8, due to the height position of the first fixing portion 21 and the protruding height of the protruding portions 25b and 25c, a gap S1 is formed between the first fixing portion 21 and the second fixing portion 41 of the adjacent ceiling panel 1 (the ceiling panel 1 on the left side in Figure 8).

On the other hand, the second fixed piece 40 has a protrusion 45b formed on the second inclined piece portion 46 side of the second base portion 45. This protrusion 45b is formed in approximately the same position as the rib strip 45a shown in Figure 4, but like the second fixed piece 41 (second protrusion 42), it abuts against the underside of the base portion 71 of the joist 70 to attach the ceiling panel 1. In other words, the second fixed piece 40 has the second fixed piece 41 (second protrusion 42) and protrusion 45b abut against the base portion 71 of the joist 70, providing a stable arrangement relative to the joist 70. Furthermore, like the protrusion 25b on the first inclined piece portion 26 side of the first fixed piece 20, the protrusion 45b is wide.

When two ceiling panels 1 are attached adjacent to the joist 70 in this way, a gap S1 is formed between the first fixing portion 21 (first protrusion 22) and the second fixing portion 41 (second protrusion 42). In other words, the protrusions in this case do not abut each other but face each other in close proximity with the gap S1 (clearance) interposed between them. In other words, this ceiling panel 1 has protrusions 25b, 25c on the panel body 10 side of the first fixing portion 21 that abut against the ceiling substrate (joist) 70 and maintain the distance between the first fixing portion 21 and the ceiling substrate 70 at a dimension that exceeds the thickness of the second protrusion 42.

After this ceiling panel 1 has been installed, if it is necessary to remove the ceiling panel 1 sandwiched between adjacent ceiling panels 1 for purposes such as partial replacement, it can be removed using the steps shown in Figures 9(a) to (c).

Figure 9(a) shows the ceiling panel 1 in its installed state. Here, the fastener 60 does not need to be removed or loosened for the first fixing portion 21 of the ceiling panel 1 adjacent to the second edge portion 10b of the ceiling panel 1 to be removed (the central ceiling panel 1 in the figure).

First, remove the fasteners 60 attached to the second elongated holes 42a of all second protrusions 42 of the second fixing portions 41 located on the second edge portion 10b of the ceiling panel 1 to be removed (see part Y11 in Figure 9(b)).

When all of the fasteners 60 for the second protrusion 42 are removed in this way, the second protrusion 42 of the ceiling panel 1 to be removed comes off the rafter 70. However, the second protrusion 42 remains held between the rafter 70 and the first protrusion 22 of the adjacent panel. When all of the fasteners 60 for the second protrusion 42 are removed, the gap S1 formed during installation disappears, the first protrusion 22 and the second protrusion 42 come into contact, and instead another gap is formed between the second protrusion 42 and the rafter 70.

Next, remove the fasteners 60 attached to the first elongated holes 22a of all first protrusions 22 of the first fixing portion 21 located on the first edge portion 10a of the ceiling panel 1 to be removed (see part Y12 in Figure 9(b)).

When all of the fasteners 60 on the first protrusion 22 are removed in this manner, the first fixing portion 21 of the ceiling panel 1 to be removed comes off the sill 70. The first fixing portion 21 is positioned below the second fixing portion 41 of the ceiling panel 1 adjacent to the first edge portion 10a, and the second fixing portion 41 is positioned with a gap between the sill 70 and the first fixing portion 21. Because the ceiling panel 1 to be removed is positioned in this manner, the first edge portion 10a can be easily moved downward.

Then, the first edge portion 10a of the ceiling panel 1 to be removed is moved downward to tilt the ceiling panel 1, and the ceiling panel 1 can be removed by sliding it diagonally downward (see Figure 9(c)).

The above panel removal method can be summarized as follows:
Remove the fasteners 60 from the second fixing portions 41 of the ceiling panel 1 to be removed.
Remove the fasteners 60 from the first fixing portions 21 of the ceiling panel 1 to be removed.
The first edge portion 10a of the ceiling panel 1 to be removed is moved downward to tilt the ceiling panel 1, and the ceiling panel 1 is then slid diagonally downward.

As such, with this ceiling panel 1, when removing the ceiling panel 1 to be removed, there is no need to remove or loosen the fasteners 60 of the first fixing portion 21 of the adjacent ceiling panel 1 on the second edge portion 10b side (see Figures 9(a) and 7(a)). In other words, the gap S1 formed between the second fixing portion 41 and the first fixing portion 21 of the adjacent panel in the installed state acts in the same way as the space S created by removing the fasteners 60 of the adjacent panel in Figure 7, allowing for easier and more efficient removal.

In this embodiment, as with Figures 1 to 7, the second fixing portion 41 (second protrusion 42) is provided with a second elongated hole 42a as a fastener insertion hole. However, the second protrusion 42 may be provided with a round hole or a notched open hole 42b (see Figure 10) instead of the second elongated hole 42a. In these cases, the ceiling panel 1 can be removed using the same procedure as in Figure 9. Removal is even easier when an open hole 42b is provided. This is explained below.

Figure 10 is a schematic bottom view and an enlarged partial bottom view showing the separated state of a ceiling panel 1 according to yet another embodiment, in which, instead of the second elongated hole 42a, an open hole 42b is provided, where the edge of the second peripheral portion 10b is opened in a notched shape. Figure 10 also shows an enlarged partial bottom view of the second fixing portion 41 (second protrusion 42) and the first fixing portion 21 of the adjacent panel in both the separated state and the engaged state. The ceiling panel 1 of this embodiment has the longitudinal cross-sectional shape shown in Figure 8.

In the example shown in Figure 10, the open hole 42b has a shape symmetrical to the first elongated hole 22a (see Figures 2 and 10). However, unlike the first elongated hole 22a, it does not have to be an elongated hole extending in a direction perpendicular to the longitudinal direction of the second edge portion; it is sufficient if at least the end face is open and the fastener 60 can be inserted through it.

After this ceiling panel 1 has been installed, if it is necessary to remove the ceiling panel 1 sandwiched between adjacent ceiling panels 1 for purposes such as partial replacement, it can be removed using the steps shown in Figures 11(a) to (c).

Figure 11(a) shows the ceiling panel 1 in its installed state. Here, the fastener 60 does not need to be removed or loosened for the first fixing portion 21 of the ceiling panel 1 adjacent to the second edge portion 10b of the ceiling panel 1 to be removed (the central ceiling panel 1 in the figure).

First, loosen the fasteners 60 attached to the open holes 42b of all second projections 42 of the second fixing portions 41 located on the second edge portion 10b of the ceiling panel 1 to be removed (see part Y21 in Figure 11(b)). At this time, the gap S1 formed in the installed state becomes smaller, the second projections 42 come closer to abutting the first projections 22, and instead another gap is formed between the second projections 42 and the joist 70.

Next, remove the fasteners 60 attached to the first elongated holes 22a of all first protrusions 22 of the first fixing portion 21 located on the first edge portion 10a of the ceiling panel 1 to be removed (see part Y22 in Figure 11(b)).

When all of the fasteners 60 on the first protrusion 22 are removed in this way, the first fixing portion 21 of the ceiling panel 1 to be removed comes off the sill 70. The first fixing portion 21 is positioned below the second fixing portion 41 of the ceiling panel 1 adjacent to the first edge portion 10a, and the second fixing portion 41 is positioned with a gap between the sill 70 and the first fixing portion 21. Because the ceiling panel 1 to be removed is positioned in this state, the first edge portion 10a becomes movable downward.

Then, the first edge portion 10a of the ceiling panel 1 to be removed is moved downward to tilt the ceiling panel 1, and the ceiling panel 1 can be removed by sliding it diagonally downward (see Figure 11(c)).

The above panel removal method can be summarized as follows:
Loosen the fasteners 60 of the second fixing portions 41 of the ceiling panel 1 to be removed.
Remove the fasteners 60 from the first fixing portions 21 of the ceiling panel 1 to be removed.
The first edge portion 10a of the ceiling panel 1 to be removed is moved downward to tilt the ceiling panel 1, and the ceiling panel 1 is then slid diagonally downward.

As such, with this ceiling panel 1, when removing the ceiling panel 1 to be removed, there is no need to remove or loosen the fasteners of the first fixing portion of the ceiling panel 1 adjacent to the second edge portion 10b (see Figure 11(a)). Furthermore, it is only necessary to loosen the second fixing portion 41 of the ceiling panel 1 to be removed, allowing for even more efficient removal than in the case of Figure 9.

In the second fixing portion 41, as shown in Figure 10, it is desirable to make all fastener insertion holes open holes 42b in order to facilitate smooth removal, but some fastener insertion holes may be second elongated holes 42a (see Figure 1). In that case, it goes without saying that when removing the ceiling panel 1, the fasteners 60 inserted into the second elongated holes 42a must of course be removed as shown in Figure 9.

As described above, Figures 1 to 7 show an engagement pattern between adjacent panels in which portions of the second fixing portion 41 and the first fixing portion 21 abut against each other and the fastener insertion hole in the second fixing portion 41 is an elongated hole. Also, Figures 8 and 9 show an engagement pattern in which there is a gap S1 between the second fixing portion 41 and the first fixing portion 21 and the fastener insertion hole in the second fixing portion 41 is an elongated hole. Furthermore, Figures 8, 10, and 11 show an engagement pattern in which there is a gap S1 between the second fixing portion 41 and the first fixing portion 21 and the fastener insertion hole in the second fixing portion 41 is an open hole 42b.

Another engagement mode may be one in which portions of the second fixing portion 41 and the first fixing portion 21 abut against each other, as shown in Figure 12, and the fastener insertion hole of the second fixing portion 41 is an open hole 42b, similar to that shown in Figure 10. In this embodiment, the ceiling panel 1 in which the second fixing portion 41 and the first fixing portion 21 abut against each other between adjacent panels may be as shown in Figure 4, but here we will explain the configuration shown in Figure 12, which has a different vertical cross-sectional shape from that shown in Figure 4.

The ceiling panel 1 shown in Figure 12, like that shown in Figure 8, has a first fixed piece 20 with two protrusions 25b and 25c, and a second fixed piece 40 with one protrusion 45b. These protrusions 25b, 25c, and 45b all abut against the base portion 71 of the joist 70 when adjacent panels are engaged with each other. In this state, the first fixed portion 21 and the second fixed portion 41 abut against each other.

In other words, in the example shown in Figure 12, the protruding height of the protrusions 25b, 25c of the first fixing portion 21 roughly matches the thickness of the second fixing portion 41 (second protrusion 42), and the height position of the protrusion 45b of the second fixing portion 41 roughly matches the height position of the second fixing portion 41 (second protrusion 42). In this way, when the ceiling panel 1 is installed, as in Figure 8, both the first fixing portion 20 and the second fixing portion 40 are more stably positioned relative to the joist 70.

After this ceiling panel 1 has been installed, if it is necessary to remove the ceiling panel 1 sandwiched between adjacent ceiling panels 1 for purposes such as partial replacement, it can be removed using the steps shown in Figures 13(a) to 13(c).

First, loosen the fasteners 60 attached to the first elongated holes 22a of all first protrusions 22 of the first fixing portion 21 of the ceiling panel 1 adjacent to the second edge portion 10b of the ceiling panel 1 to be removed (see part Y31 in Figure 13(a)). This creates a space S.

Next, loosen the fasteners 60 attached to the open holes 42b of all second projections 42 of the second fixing portions 41 located on the second edge portion 10b of the ceiling panel 1 to be removed. When all of the fasteners 60 of the second projections 42 have been loosened in this manner, the second fixing portions 41 move downward in the space S and are held from below by the first fixing portions 21 of the adjacent panel that have already been loosened (see part Y32 in Figure 13(b)).

Then, remove the fasteners 60 attached to the first elongated holes 22a of all first protrusions 22 of the first fixing portions 21 located on the first edge portion 10a of the ceiling panel 1 to be removed (see part Y33 in Figure 13(b)).

When all of the fasteners 60 on the first protrusion 22 are removed in this manner, the first fixing portion 21 of the ceiling panel 1 to be removed comes off the sill 70. The first fixing portion 21 is positioned below the second fixing portion 41 of the ceiling panel 1 adjacent to the first edge portion 10a, and the second fixing portion 41 is positioned with a space S between the sill 70 and the first fixing portion 21. Because the ceiling panel to be removed is positioned in this manner, the first edge portion 10a becomes movable downward.

Then, the first edge portion 10a of the ceiling panel 1 to be removed is moved downward to tilt the ceiling panel 1, and the ceiling panel 1 can be removed by sliding it diagonally downward (see Figure 13(c)).

The above panel removal method can be summarized as follows:
Loosen the fastener 60 of the first fixing portion 21 of the ceiling panel 1 adjacent to the second edge portion 10b side of the ceiling panel 1 to be removed.
Loosen the fasteners 60 of the second fixing portions 41 of the ceiling panel 1 to be removed.
Remove the fasteners 60 from the first fixing portions 21 of the ceiling panel 1 to be removed.
The first edge portion 10a of the ceiling panel 1 to be removed is moved downward to tilt the ceiling panel 1, and the ceiling panel 1 is then slid diagonally downward.

As such, in the case of the ceiling panel 1 shown in Figure 12, unlike the ceiling panel removal methods shown in Figures 9 and 11, it is necessary to loosen the fasteners 60 of the first fixing portion 21 of the adjacent panel. However, there is no need to remove the fasteners 60 of the second fixing portion 41 of the ceiling panel 1 to be removed; they only need to be loosened, allowing for efficient removal.

In the ceiling panel 1 shown in Figure 8, the height position of the protrusions 25b, 25c that abut against the base portion 71 of the joist 70 has a predetermined height relationship relative to the height position of the first fixing portion 21 in order to form the gap S1. However, the other protrusions 45b shown in Figure 8 and the protrusions 25b, 25c, and 45b shown in Figure 12 do not have to abut against the base portion 71, and may not be present at all. In particular, in the embodiments shown in Figures 12 and 13, the ceiling panel 1 of Figure 4 may be used instead of the ceiling panel 1 of Figure 12.

Of course, in order to stably attach the ceiling panel 1 to the joist 70, it is desirable to use a ceiling panel 1 in which the protrusions 25b, 25c, and 45b have fixing pieces that abut against the joist 70, as shown in Figures 8 and 12.

REFERENCE SIGNS LIST 1 Ceiling panel 10 Panel body 10a First edge portion 10b Second edge portion 20 First fixing piece 21 First fixing portion 22 First protruding piece 22a First elongated hole (notch)
23 First recess 25b, 25c Protruding portion 40 Second fixing piece 41 Second fixing portion 42 Second protruding piece 42a Second elongated hole 42b Open hole 43 Second recess 45b Protruding portion 60 Fixing member 65 Reinforcing piece 70 Ceiling underlayment (rough joist)

Claims (12)

A ceiling panel having a flat panel body having a rectangular outer shape in a plan view, and a first edge portion and a second edge portion located on both sides of one direction of the panel body being fixed to a ceiling substrate,
The first edge portion of the panel body is provided with a first fixing portion that is fixed to the ceiling substrate by a fastener along the longitudinal direction of the first edge portion,
a second fixing portion that is fixed to the ceiling substrate by a fastener along the longitudinal direction of the second edge portion of the panel body;
The first fixing portion includes a first protruding piece whose back surface faces and is close to a part of the second fixing portion of the adjacent ceiling panel, and a first recess that exposes a part of the second fixing portion of the adjacent ceiling panel,
The second fixing portion is characterized by comprising: a second protrusion having a surface that faces and is close to the first protrusion of an adjacent ceiling panel and a surface that can be partially exposed by the first recess of the adjacent ceiling panel; and a second recess that is blocked by the first protrusion of the adjacent ceiling panel. In claim 1,
A ceiling panel characterized in that multiple pairs of the first protrusions and the first recesses are alternately provided on the first edge portion, and multiple pairs of the second protrusions and the second recesses are provided on the second edge portion. In claim 1 or 2,
The ceiling panel is characterized in that the first protrusion and the second protrusion are disposed at a height position on the rear side of the panel body. In any one of claims 1 to 3,
A ceiling panel characterized in that a first long hole for inserting a fastener is provided in the first protrusion at a position corresponding to the second recess of the ceiling panel adjacent to the first edge portion, the first long hole extending in a direction perpendicular to the longitudinal direction of the first edge portion. In any one of claims 1 to 4,
A ceiling panel characterized in that a second elongated hole for inserting a fastener is provided in the second protrusion at a position corresponding to the first recess of the ceiling panel adjacent to the second edge portion, the second elongated hole extending along the longitudinal direction of the second edge portion. In any one of claims 1 to 5,
A ceiling panel characterized in that the first fixing portion has a protrusion on the panel body side that abuts against the ceiling substructure and maintains the distance between the first fixing portion and the ceiling substructure at a dimension that exceeds the thickness of the second protrusion. In any one of claims 1 to 4,
A ceiling panel characterized in that an open hole for inserting a fastener is provided in the second protruding piece at a position corresponding to the first recess of the ceiling panel adjacent to the second edge portion. In claim 7,
A ceiling panel characterized in that a protrusion is provided on the panel body side of the first fixing portion, which abuts against the ceiling substructure and maintains the distance between the first fixing portion and the ceiling substructure at a dimension that exceeds the thickness of the second protrusion. A panel removal method for removing one ceiling panel from between a ceiling panel on the first edge side and a ceiling panel on the second edge side when a plurality of ceiling panels according to any one of claims 1 to 5 are attached to the ceiling substrate,
Loosen the fastener of the first fixing portion of the ceiling panel adjacent to the second edge portion side of the ceiling panel to be removed;
Remove the fastener of the second fixing portion of the ceiling panel to be removed;
Remove the fastener of the first fixing portion of the ceiling panel to be removed;
A panel removal method, comprising: moving the first edge portion of the ceiling panel to be removed downward to tilt the ceiling panel, and then sliding the ceiling panel diagonally downward. A panel removal method for removing one ceiling panel from between the ceiling panel on the first edge side and the ceiling panel on the second edge side when a plurality of ceiling panels according to claim 6 are attached to the ceiling substrate, comprising:
Remove the fastener of the second fixing portion of the ceiling panel to be removed;
Remove the fastener of the first fixing portion of the ceiling panel to be removed;
A panel removal method, comprising: moving the first edge portion of the ceiling panel to be removed downward to tilt the ceiling panel, and then sliding the ceiling panel diagonally downward. A panel removal method for removing one ceiling panel from between the ceiling panel on the first edge side and the ceiling panel on the second edge side when a plurality of ceiling panels according to claim 7 are attached to the ceiling substrate, comprising:
Loosen the fastener of the first fixing portion of the ceiling panel adjacent to the second edge portion side of the ceiling panel to be removed;
Loosen the fastener of the second fixing portion of the ceiling panel to be removed;
Remove the fastener of the first fixing portion of the ceiling panel to be removed;
A panel removal method, comprising: moving the first edge portion of the ceiling panel to be removed downward to tilt the ceiling panel, and then sliding the ceiling panel diagonally downward. A panel removal method for removing one ceiling panel from between the ceiling panel on the first edge side and the ceiling panel on the second edge side when a plurality of ceiling panels according to claim 8 are attached to the ceiling substrate, comprising:
Loosen the fastener of the second fixing portion of the ceiling panel to be removed;
Remove the fastener of the first fixing portion of the ceiling panel to be removed;
A panel removal method, comprising: moving the first edge portion of the ceiling panel to be removed downward to tilt the ceiling panel, and then sliding the ceiling panel diagonally downward.