Sheet metal box cover, sheet metal box, and lighting fixture

Abstract

To provide a cover for a sheet metal box, a sheet metal box, and a lighting fixture for simplifying the work of attaching a cover for the sheet metal box to the opening of the sheet metal box body and securing the rigidity of the side face of the sheet metal box body.SOLUTION: A cover for a sheet metal box includes a side flange extending from a first end in a first direction intersecting the upper surface at each of the first ends that are two opposing sides of the upper surface, and a front flange extending from the second end in the first direction at each of the second ends that are the other two opposite sides of the upper surface. The front flange includes two first front flanges spaced apart from each other and arranged side by side, and a second front flange provided in a recess formed between the two first front flanges. Further, the outer surface portion of the second front flange is recessed toward the inner side of the upper surface portion from the outer surface portion of the first front flange in the third direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cover for a sheet metal box, a sheet metal box, and a lighting fixture. [Background technology]

[0002] Sheet metal boxes constructed from sheet metal are sometimes used as heat sinks.

[0003] For example, Patent Document 1 discloses a heat sink fan equipped with a box-shaped heat dissipation heat sink. The heat dissipation heat sink described in Patent Document 1 has an open top surface and a bottom surface that contacts a heat generating element. Furthermore, heat dissipation fins are formed on at least two opposing sides of the four side surfaces of the heat dissipation heat sink. A crossflow fan is housed inside the heat dissipation heat sink. Both ends of the rotation shaft of the crossflow fan are rotatably supported by the other two of the four side surfaces of the heat dissipation heat sink via bearings. A lid is attached to the open top surface of the box-shaped heat dissipation heat sink in a lid-like manner.

[0004] Generally, heat sinks are made of a material such as aluminum that has excellent thermal conductivity. The box-shaped heat sink for heat dissipation described in Patent Document 1 accommodates a crossflow fan inside, and therefore requires strength to support the crossflow fan. For this reason, the heat sink for heat dissipation is formed by a mold casting method such as aluminum die casting. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-161889 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, heat sinks are generally made of a material such as aluminum, which has excellent thermal conductivity. The heat sink for heat dissipation described in Patent Document 1 is formed by a mold casting method such as aluminum die casting because it needs to be strong enough to support a crossflow fan. Thus, when forming a heat sink by a mold casting method, there is a limit to how thin the heat sink can be made, making it difficult to reduce its weight.

[0007] However, depending on the type of device in which the heat sink is installed, there are cases where it is required to reduce the weight of the heat sink. In order to reduce the weight of the heat sink, it is conceivable to form the heat sink by combining thin aluminum metal sheets, for example.

[0008] Consider the case where thin aluminum metal sheets are combined to form a box-shaped heat sink with an open top, a bottom that contacts the heat generating element, and four side surfaces extending from the bottom. When attaching a cover to cover the open top, it is necessary to attach the cover while controlling all four of the side surfaces. This will be explained in detail below.

[0009] In order to improve heat dissipation, heat sinks often leave the upper edges of each side free, rather than joining adjacent sides. Because each side is made of thin sheet metal, the free upper edges are unstable and prone to movement. In particular, when thin sheet metal is formed into a U-shape or a C-shape, the two opposing free edges tend to spread apart, i.e., toward the outside of the C-shape.

[0010] Therefore, when attaching a cover to close the open top surface of a box-shaped heat sink, it is necessary to attach the cover while controlling all four upright sides. In this case, the position of the free end of the metal plate is unstable and tends to move, and each side moves independently due to individual differences in the metal plate, making the work of attaching the cover extremely difficult.

[0011] Furthermore, because the box shape is constructed from thin aluminum sheet metal, the rigidity of the side surfaces of the box shape is weak. Meanwhile, the cover is formed slightly larger than the box shape and is attached so that its outer edges are on the outside of the four side surfaces of the box shape. In this case, if an external force is applied to the four side surfaces from the outside, there is a possibility that the side surfaces will collapse toward the inside of the box because there is no support mechanism inside the box to support the side surfaces. Thus, when a box shape is constructed from thin aluminum sheet metal, the rigidity of the side surfaces of the box shape is weak, and the side surfaces cannot withstand the external force from the outside, resulting in deformation of the box shape.

[0012] The present disclosure has been made to solve such problems, and aims to provide a cover for a sheet metal box, a sheet metal box, and a lighting fixture that simplify the work of attaching them to an opening in a sheet metal box body with an open top and that can ensure the rigidity of the side surfaces of the sheet metal box body. [Means for solving the problem]

[0013] The sheet metal box cover according to the present disclosure comprises an upper surface portion formed in an overall quadrangular shape in a plan view, side flange portions extending from first ends, which are two opposing sides of four sides of the upper surface portion, toward a first direction intersecting the upper surface portion, and front flange portions extending from second ends, which are the other two opposing sides of the upper surface portion, toward the first direction, the second ends extending in a second direction intersecting the first direction, and the first ends extending in a third direction intersecting the first direction and the second direction, and the front flange portions are provided at each of the second ends. a second front flange disposed in the recess, the recess being formed between the two first front flanges arranged side by side in the second direction and spaced apart from each other at each of the second ends, and the second front flange disposed in the recess, the recess being formed in each of the second ends from a portion of the second end to which the first front flange is connected, toward the inside of the upper surface portion in the third direction, and the outer surface of the second front flange is disposed to be recessed more toward the inside of the upper surface portion in the third direction than the outer surface of the first front flange The length D1 of the first front flange portion in the first direction is shorter than the length D2 of the second front flange portion in the first direction. It is something.

[0014] The sheet metal box of the present disclosure comprises a box-shaped sheet metal box body having an opening on the top surface, and the above-mentioned sheet metal box cover that is removably attached to cover the opening of the sheet metal box body.

[0015] The lighting fixture according to the present disclosure comprises a frame that is installed on a mounting portion, a light source unit that is arranged inside the frame and has a light source that irradiates light toward an illumination space, a movable frame that rotates the light source unit relative to the frame, a heat sink that is composed of the above-mentioned sheet metal box and dissipates heat generated by the light source unit, a power supply unit that supplies electric power, and a lighting device that supplies electric power from the power supply unit to the light source unit and causes the light source of the light source unit to emit light. [Effects of the Invention]

[0016] According to the sheet metal box cover, sheet metal box, and lighting fixture disclosed herein, the sheet metal box cover includes side flanges provided on first ends, which are two opposing sides of the top surface, and extending from the first ends in a first direction intersecting the top surface, and front flanges provided on second ends, which are the other two opposing sides of the top surface, and extending from the second ends in the first direction. The front flanges include two first front flanges arranged side by side and spaced apart from each other, and a second front flange provided in a recess formed between the two first front flanges. The outer surface of the second front flange is recessed inward of the top surface in a third direction relative to the outer surface of the first front flange. Therefore, the sheet metal box cover can be easily attached to the sheet metal box body so that the first front flange is positioned outside the opening of the sheet metal box body and the second front flange is positioned inside the opening of the sheet metal box body. Furthermore, since the second front flange of the attached sheet metal box cover supports the side portion of the sheet metal box body from the inside of the sheet metal box body, the sheet metal box has rigidity that can withstand external forces applied from the outside. Therefore, the sheet metal box cover according to the present disclosure simplifies the work of attaching the cover to the opening of the sheet metal box body, which has an opening on its top surface that corresponds to the cover. Furthermore, the sheet metal box and lighting fixture according to the present disclosure can ensure the rigidity of the side portion of the sheet metal box body. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view showing the configuration of a sheet metal box cover according to Embodiment 1. FIG. [Figure 2] 2 is a perspective view showing how the sheet metal box cover shown in FIG. 1 is attached to the sheet metal box body. FIG. [Figure 3] 2 is a perspective view showing how the sheet metal box cover shown in FIG. 1 is attached to the sheet metal box body. FIG. [Figure 4] 1. FIG. 4 is a front view schematically illustrating a state in which the lower end of the side flange of the sheet metal box cover shown in FIG. 1 is lightly in contact with the upper edge of the opening of the sheet metal box body. [Figure 5]1. FIG. 4 is a side view schematically showing a state in which the lower tip of the second front flange of the sheet metal box cover shown in FIG. 1 is lightly in contact with the upper edge of the opening of the sheet metal box body. [Figure 6] 2 is a perspective view showing a state in which the sheet metal box cover shown in FIG. 1 is attached to the sheet metal box body. FIG. [Figure 7] 2 is a front view schematically showing a state in which the sheet metal box cover shown in FIG. 1 is attached to the sheet metal box body. FIG. [Figure 8] 2 is a side view schematically showing a state in which the sheet metal box cover shown in FIG. 1 is attached to the sheet metal box body. FIG. [Figure 9] 1 is an exploded perspective view of a sheet metal box cover and a sheet metal box body according to the first embodiment. FIG. [Figure 10] 10 is a perspective view showing a state in which the sheet metal box cover shown in FIG. 9 is attached to the sheet metal box body. FIG. [Figure 11] FIG. 10 is an exploded perspective view showing the configuration of a sheet metal box body according to a second embodiment. [Figure 12] FIG. 10 is a perspective view showing the configuration of a sheet metal box cover and a sheet metal box body according to a second embodiment. [Figure 13] FIG. 11 is an exploded perspective view showing the configuration of a lighting fixture according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of a sheet metal box cover, a sheet metal box, and a lighting fixture according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the present disclosure. Furthermore, the present disclosure includes all possible combinations of the configurations shown in the following embodiments and their modifications. In each drawing, components with the same reference numerals are identical or equivalent, and this applies throughout the entire specification. Note that the relative dimensional relationships or shapes of the components in each drawing may differ from those in actuality.

[0019] In addition, in each drawing, the width direction of the sheet metal box cover and the sheet metal box is the X-axis direction, and the depth direction of the sheet metal box cover and the sheet metal box is the Y-axis direction. The X-axis direction and the Y-axis direction intersect with each other. The direction intersecting the X-axis direction and the Y-axis direction is the Z-axis direction. The Z-axis direction is the height direction of the sheet metal box cover and the sheet metal box, for example, the vertical direction. The upward direction in the Z-axis direction is referred to as the upward direction Z1, and the downward direction in the Z-axis direction is referred to as the downward direction Z2. The Z-axis direction, the X-axis direction, and the Y-axis direction may be referred to as the first direction, the second direction, and the third direction, respectively.

[0020] Embodiment 1 FIG. 1 is a perspective view showing the configuration of a sheet metal box cover according to a first embodiment. FIGS. 2 and 3 are perspective views showing how the sheet metal box cover shown in FIG. 1 is attached to a sheet metal box main body. FIG. 4 is a front view schematically showing a state in which a lower end portion of a side flange of the sheet metal box cover shown in FIG. 1 is lightly in contact with an upper edge of an opening in the sheet metal box main body. FIG. 5 is a side view schematically showing a state in which a lower end portion of a second front flange of the sheet metal box cover shown in FIG. 1 is lightly in contact with an upper edge of an opening in the sheet metal box main body. FIG. 6 is a perspective view showing how the sheet metal box cover shown in FIG. 1 is attached to the sheet metal box main body. FIG. 7 is a front view schematically showing how the sheet metal box cover shown in FIG. 1 is attached to the sheet metal box main body. FIG. 8 is a side view schematically showing how the sheet metal box cover shown in FIG. 1 is attached to the sheet metal box main body. FIG. 9 is an exploded perspective view of the sheet metal box cover according to the first embodiment and the sheet metal box main body. Fig. 10 is a perspective view showing a state in which the sheet metal box cover shown in Fig. 9 is attached to the sheet metal box body. In Fig. 10, for the sake of explanation, some components are shown in perspective with broken lines.

[0021] [Configuration of sheet metal box cover] As shown in FIG. 1 , the sheet metal box cover 1 according to the first embodiment has a flat upper surface portion 5. The upper surface portion 5 has a quadrangular shape in plan view. The quadrangular shape may be a rectangle, a rectangle with corners of curvature R, a substantially rectangular shape, a polygon such as a hexagon, a rhombus, a trapezoid, or a parallelogram. In the first embodiment, the upper surface portion 5 has a rectangular shape in plan view. The X-axis direction of the upper surface portion 5 is the longitudinal direction of the upper surface portion 5, and the Y-axis direction of the upper surface portion 5 is the lateral direction of the upper surface portion 5. The longitudinal ends of the upper surface portion 5, i.e., the lateral ends, are referred to as first ends 5a and 5b. The lateral ends of the upper surface portion 5, i.e., the longitudinal ends, are referred to as second ends 5c and 5d. While the above description describes the upper surface portion 5 as being flat, the present invention is not limited to this. For example, at least a portion of the upper surface portion 5 may be bulging upward or may be pointed. Furthermore, the upper surface portion 5 may be provided with one or more parallel ridges or protrusions formed by drawing or the like.

[0022] As shown in FIG. 1, the sheet metal box cover 1 according to the first embodiment has two side flanges 2a and 2b. The side flanges 2a and 2b extend downward in the Z2 direction from first ends 5a and 5b (i.e., both longitudinal ends) of the top surface 5. The side flanges 2a and 2b are arranged opposite each other. The side flanges 2a and 2b are each formed in a flat plate shape. Each of the side flanges 2a and 2b is provided with a screw hole 20, which is a through-hole into which a fastener 80 (see FIG. 2), such as a screw, is inserted. The side flanges 2a and 2b may be collectively referred to as the side flange 2.

[0023] 1, the sheet metal box cover 1 according to the first embodiment has four first front flanges 3a, 3b, 3c, and 3d. The first front flanges 3a, 3b, 3c, and 3d extend downward in the Z2 direction from second ends 5c and 5d of the top surface 5 (i.e., both ends in the short direction). The first front flanges 3a, 3b, 3c, and 3d are each formed in a flat plate shape. The first front flanges 3a, 3b, 3c, and 3d have the same shape. The first front flanges 3a, 3b, 3c, and 3d may be collectively referred to as the first front flange 3.

[0024] Of the four first front flanges 3, the first front flanges 3a and 3b are provided at a second end 5c, which is one of both ends in the short direction of the top surface 5. At the second end 5c, the first front flanges 3a and 3b are arranged side by side and spaced apart from each other via a recess 5e. The recess 5e is formed in the central portion of the second end 5c. The recess 5e is formed at the second end 5c, recessed inward into the top surface 5 in the Y-axis direction from the portion where the first front flanges 3a and 3b are connected. The recess 5e has a rectangular shape in a plan view. The first front flanges 3a and 3b are each arranged closer to the end of the second end 5c in the X-axis direction.

[0025] Similarly, of the four first front flanges 3, the other first front flanges 3c and 3d are provided at a second end 5d, which is the other of both ends in the short direction of the top surface 5. At the second end 5d, the first front flanges 3c and 3d are arranged side by side and spaced apart from each other via recesses 5e. The configuration of the recesses 5e provided at the second end 5d is the same as the configuration of the recesses 5e provided at the second end 5c described above. That is, the recesses 5e are formed at the second end 5d by being recessed inward of the top surface 5 in the Y-axis direction from the portion where the first front flanges 3a and 3b are connected. The first front flanges 3c and 3d are each arranged closer to the end of the second end 5d in the X-axis direction.

[0026] As shown in FIGS. 1 and 10, the first front flange portions 3a and 3c are arranged in positions facing each other, and the first front flange portions 3b and 3d are arranged in positions facing each other.

[0027] As shown in FIG. 1, the sheet metal box cover 1 according to the first embodiment has two second front flanges 4a, 4b. The second front flanges 4a, 4b extend downward in the Z2 direction from second ends 5c, 5d of the top surface 5, i.e., from both ends in the short direction. The second front flanges 4a, 4b are each formed in a flat plate shape. The second front flanges 4a, 4b have the same shape. The second front flanges 4a, 4b may be collectively referred to as the second front flange 4.

[0028] Of the two second front flanges 4, one second front flange 4a is provided at a second end 5c, which is one of both ends in the short direction of the top surface portion 5. At the second end 5c, the second front flange 4a is disposed in a recess 5e formed between the two first front flanges 3a, 3b. The second front flange 4a extends downward in the Z2 direction from the end of the recess 5e. The second front flange 4a is disposed at the center of the second end 5c in the X-axis direction. At the second end 5c, the first front flange 3a, the second front flange 4a, and the first front flange 3b are disposed side by side in this order in the X-axis direction.

[0029] Of the two second front flanges 4, the other second front flange 4b ​​is provided at a second end 5d, which is the other of both ends in the short direction of the top surface portion 5. At the second end 5d, the second front flange 4b ​​is disposed in a recess 5e formed between the two first front flanges 3c, 3d. The second front flange 4a extends downward in the Z2 direction from the end of the recess 5e. The second front flange 4b ​​is disposed in the center of the second end 5d. At the second end 5d, the first front flange 3c, the second front flange 4b, and the first front flange 3d are arranged side by side in this order in the X-axis direction.

[0030] The outer surface portions 41 (see FIG. 5) of the second front flanges 4a and 4b are arranged parallel to the outer surface portions 31 (see FIG. 5) of the first front flanges 3a, 3b, 3c, and 3d. The outer surface portions 41 (see FIG. 5) of the second front flanges 4a and 4b are arranged closer to point O, which is the center of the upper surface portion 5, than the outer surface portions 31 (see FIG. 5) of the first front flanges 3a, 3b, 3c, and 3d. In other words, the second front flanges 4a and 4b are arranged recessed in the Y-axis direction toward point O, which is the center of the upper surface portion 5, compared to the first front flanges 3a, 3b, 3c, and 3d.

[0031] 1, the length D1 in the Z-axis direction of the first front flanges 3a, 3b, 3c, and 3d is shorter than the length D2 in the Z-axis direction of the second front flanges 4a and 4b. That is, as shown in FIG. 5, the second front flanges 4a and 4b protrude further in the downward direction Z2 than the first front flanges 3a, 3b, 3c, and 3d.

[0032] As shown in FIG. 5 , the length in the Y-axis direction from point O, which is the center of the top surface portion 5 in the Y-axis direction, to the outer surface portion 31 of the first front flange portions 3a, 3b, 3c, and 3d is defined as length L1. Similarly, the length in the Y-axis direction from point O, which is the center of the top surface portion 5 in the Y-axis direction, to the outer surface portion 41 of the second front flange portions 4a and 4b is defined as length L2. In this case, length L1 is longer than length L2. Therefore, a space is formed inside the first front flange portions 3a, 3b, 3c, and 3d that is larger in the Y-axis direction than the inside of the second front flange portions 4a and 4b by the absolute value of the difference between length L1 and length L2. It is desirable that the absolute value of the difference between length L1 and length L2 be the same as or approximately the same as the plate thickness of the side surface portion 12 of the sheet metal box main body 10.

[0033] 1, the length D3 in the Z-axis direction of the side flanges 2a, 2b is longer than the length D2 in the Z-axis direction of the second front flanges 4a, 4b. That is, the side flanges 2a, 2b protrude further in the downward direction Z2 than the second front flanges 4a, 4b. However, this is not limited to this case, and the length D3 in the Z-axis direction of the side flanges 2a, 2b may be the same as the length D2 in the Z-axis direction of the second front flanges 4a, 4b.

[0034] The sheet metal box cover 1 is made of a material with excellent thermal conductivity. The sheet metal box cover 1 is formed by bending a sheet metal with excellent thermal conductivity, such as aluminum. Therefore, the top surface 5, the side flange 2, the first front flange 3, and the second front flange 4 are integrally molded. However, this is not the only possible case. The side flange 2, the first front flange 3, and the second front flange 4 may be formed as separate pieces and then joined to the top surface 5 to form the sheet metal box cover 1.

[0035] [Configuration of sheet metal box body 10] In the first embodiment, the sheet metal box cover 1 is attached to a box-shaped sheet metal box main body 10 having an opening 13 on the top surface. The sheet metal box cover 1 is attached so as to cover the opening 13 of the sheet metal box main body 10. The sheet metal box cover 1 is detachably attached to the sheet metal box main body 10. The sheet metal box main body 10 is made of sheet metal having excellent thermal conductivity, such as aluminum.

[0036] The sheet metal box cover 1 and the sheet metal box main body 10 constitute a sheet metal box 40 (see FIG. 10). The sheet metal box 40 is used, for example, as a heat sink for a lighting fixture 50 (see FIG. 13). In this case, as shown in FIG. 2, the side portion 12 of the box-shaped sheet metal box main body 10 is attached to the light source unit 52, which is the main body of the lighting fixture 50, by a fastener 82 such as a screw via an arm 22. Furthermore, as shown in FIG. 2, the bottom portion 11 of the box-shaped sheet metal box main body 10 is attached to the light source unit 52, which is the main body of the lighting fixture 50, by a fastener 81 such as a screw. The bottom portion 11 comes into contact with the light source unit 52, which is a heat-generating element, so that the sheet metal box 40 is thermally connected to the light source unit 52. The configuration of the lighting fixture 50 will be described later.

[0037] The box-shaped sheet metal box main body 10 has four side surfaces 12 and a bottom surface 11. The four side surfaces 12 are erected from the bottom surface 11 in the upward direction Z1. The four side surfaces 12 form the side surfaces of the sheet metal box main body 10. The bottom surface 11 has a circular or approximately circular shape in a plan view. The bottom surface 11 is provided with screw holes 110 (see FIG. 9) constituted by through holes into which fasteners 81 such as screws shown in FIG. 2 are inserted. The configuration of the bottom surface 11 will be described later. The top surface portion of the sheet metal box main body 10 is open in the upward direction Z1. Hereinafter, the open top surface portion of the sheet metal box main body 10 will be referred to as an opening 13. The outer contour of the opening 13 will be referred to as an upper edge portion 13a of the opening 13. Adjacent side surfaces 12 of the four side surfaces 12 constituting the sheet metal box main body 10 are not joined together. Therefore, each of the side surfaces 12 is fixed to the bottom surface 11 in a cantilevered manner. The upper end portions 125 (see FIGS. 5 and 11) of the side surfaces 12 are free ends. The upper end portions 125 of the side surfaces 12 form the upper edge portions 13a of the opening 13 of the sheet metal box body 10.

[0038] Of the four side surface portions 12, two opposing side surface portions 12a, 12b are provided with screw holes 121 (see FIG. 9) each formed as a through hole into which a fastener 82 such as a screw shown in FIG. 2 is inserted. Also, grooves 123 shown in FIG. 9 are provided in these side surface portions 12a, 12b. The arm 22 is attached so as to fit into the grooves 123. This makes it possible to prevent assembly errors when attaching the arm 22 to the side surface portions 12a, 12b.

[0039] [How to attach the sheet metal box cover 1] 2 to 8, a method for attaching the sheet metal box cover 1 to the sheet metal box body 10 will be described. The sheet metal box cover 1 is attached to the sheet metal box body 10 so that the side flange 2 and the second front flange 4 are positioned inside the opening 13 of the sheet metal box body 10, and the first front flange 3 is positioned outside the opening 13.

[0040] When attaching the sheet metal box cover 1 to the sheet metal box body 10, first, as shown in Fig. 2, the worker moves the sheet metal box cover 1 toward the opening 13 of the sheet metal box body 10 in the direction of arrow A. The direction of arrow A is parallel to the downward direction Z2. Note that the worker here is not limited to a human being, but also includes an assembly device, an assembly robot, etc.

[0041] Furthermore, when the sheet metal box cover 1 is brought closer to the opening 13 of the sheet metal box main body 10 in the direction of arrow A, as shown in Figure 3, the downward Z2 side tips 2aa, 2bb of the side flanges 2a, 2b of the sheet metal box cover 1 lightly come into contact with the upper edge 13a of the opening 13 of the sheet metal box main body 10.

[0042] This state is shown in FIG. 4. FIG. 4 schematically illustrates a state in which the downward Z2-side tip portions 2aa, 2bb of the side flange portions 2a, 2b of the sheet metal box cover 1 according to the first embodiment are lightly in contact with the upper edge portion 13a of the opening 13 of the sheet metal box main body 10. As shown in FIG. 4, in the sheet metal box main body 10, the opposing side portions 12a, 12b and the bottom portion 11 form a U-shape in a front view (when viewed from a direction perpendicular to the X-axis direction and the Z-axis direction). As described above, at least the upper end portions 125 of the adjacent side portions 12 of the sheet metal box main body 10 are not joined together. Therefore, the upper end portions 125 are free ends. As a result, as shown in FIG. 4, the upper end portions 125 of the side portions 12a, 12b tend to move away from each other. That is, the side portions 12a, 12b are each inclined so that the U-shape widens outward as they move upward Z1. Therefore, the tip portions 2aa, 2bb on the downward direction Z2 side of the side flange portions 2a, 2b of the sheet metal box cover 1 are inserted into the sheet metal box body 10 so as to naturally come into contact with the inner wall of the upper edge portion 13a of the opening 13 of the sheet metal box body 10. The side flange portions 2a, 2b of the sheet metal box cover 1 are guided as they are by the inner wall of the side portion 12 of the sheet metal box body 10 and inserted into the sheet metal box body 10. Therefore, when the sheet metal box cover 1 is attached to the sheet metal box body 10, the side flange portions 2a, 2b are positioned inside the sheet metal box body 10.

[0043] Furthermore, when the sheet metal box cover 1 is in the state shown in Figures 3 and 4, the downward Z2 side tip portions 4aa, 4bb of the second front flange portions 4a, 4b of the sheet metal box cover 1 successively or almost simultaneously lightly contact the upper edge portion 13a of the opening 13 of the sheet metal box main body 10.

[0044] This state is shown in FIG. 5. FIG. 5 schematically illustrates a state in which the downward Z2-side tip portions 4aa, 4bb of the second front flange portions 4a, 4b of the sheet metal box cover 1 according to the first embodiment are lightly in contact with the upper edge portion 13a of the opening 13 of the sheet metal box main body 10. As shown in FIG. 5, in the sheet metal box main body 10, the opposing side surface portions 12c, 12d and the bottom surface portion 11 form a U-shape in a side view (when viewed from a direction perpendicular to the Y-axis direction and the Z-axis direction). As described above, at least the upper end portions 125 of the adjacent side surface portions 12 of the sheet metal box main body 10 are not joined together. Therefore, the upper end portions 125 are free ends. As a result, as shown in FIG. 5, the upper end portions 125 of the side surface portions 12c, 12d tend to move away from each other. That is, the side surface portions 12c, 12d are each inclined toward the outside of the U-shape as they move upward Z1. Therefore, the downward Z2-side tip portions 4aa, 4bb of the second front flange portions 4a, 4b of the sheet metal box cover 1 are naturally inserted into the sheet metal box body 10 so as to come into contact with the inner wall of the upper edge portion 13a of the opening 13 of the sheet metal box body 10. The second front flange portions 4a, 4b of the sheet metal box cover 1 are guided as they are by the inner wall of the side portion 12 of the sheet metal box body 10 and inserted into the sheet metal box body 10. Therefore, when the sheet metal box cover 1 is attached to the sheet metal box body 10, the second front flange portions 4a, 4b are positioned inside the sheet metal box body 10.

[0045] On the other hand, the first front flanges 3a, 3b, 3c, and 3d are each disposed outside the sheet metal box body 10 when the sheet metal box cover 1 is attached to the sheet metal box body 10. The attachment and arrangement of the first front flanges 3a, 3b, 3c, and 3d will be described below.

[0046] 3 and 4, the sheet metal box cover 1 is further moved closer to the opening 13 of the sheet metal box body 10 in the direction of arrow A. Then, the downward Z2-side tips 3aa, 3bb, 3cc, and 3dd of the first front flanges 3a, 3b, 3c, and 3d of the sheet metal box cover 1 are guided by the outer wall of the upper edge 13a of the opening 13 of the sheet metal box body 10 and fitted into the sheet metal box body 10. At this time, as shown in FIG. 5, the upper ends 125 of the side surfaces 12c and 12d are each inclined toward the outside of the U-shape. Therefore, if necessary, the worker gently pushes the side surfaces 12c and 12d toward the inside of the U-shape in the direction of arrow B in FIG. 5. This allows the sheet metal box cover 1 to be easily fitted to the sheet metal box body 10 so that the first front flanges 3a, 3b, 3c, and 3d of the sheet metal box cover 1 are positioned outside the side surfaces 12c and 12d. Thus, as shown in Fig. 6, the side flanges 2a and 2b and the second front flanges 4a and 4b of the sheet metal box cover 1 are fully inserted into the sheet metal box body 10, and the first front flanges 3a, 3b, 3c, and 3d of the sheet metal box cover 1 are positioned outside the sheet metal box body 10. In this state, as shown in Fig. 8, the upper edge 13a of the opening 13 of the sheet metal box body 10 abuts against the inner surfaces of the first front flanges 3a, 3b, 3c, and 3d. This restricts movement of the sheet metal box cover 1 in the direction of arrow A.

[0047] As a result, the first front flanges 3a, 3b and the second front flange 4a of the sheet metal box cover 1 cooperate to sandwich the side surface 12c of the sheet metal box main body 10 and support the side surface 12c from both the outside and the inside. Similarly, the first front flanges 3c, 3d and the second front flange 4b ​​of the sheet metal box cover 1 cooperate to sandwich the side surface 12d of the sheet metal box main body 10 and support the side surface 12d from both the outside and the inside.

[0048] 6, the position of the screw hole 120 formed from a through-hole provided in the side surface portion 12 of the sheet metal box main body 10 coincides with the position of the screw hole 20 (see FIG. 1) provided in the side surface flange portions 2a, 2b of the sheet metal box cover 1. Therefore, the sheet metal box cover 1 is attached to the sheet metal box main body 10 by inserting and fastening a fastener 80 such as a screw into the screw hole 120 and the screw hole 20. When a screw is used as the fastener 80, the screw holes 20 and 120 are provided with a female thread.

[0049] This state is shown schematically in FIGS. 7 and 8.

[0050] As shown in FIG. 7 , the side flanges 2a and 2b of the sheet metal box cover 1 are disposed inside the sheet metal box body 10 and secured by fasteners 80, such as screws. As a result, the side surfaces 12a and 12b, which had previously been inclined toward the outside of the U-shape, are reoriented so that they are perpendicular to the bottom surface 11. In other words, as the fasteners 80 are tightened, the inclination of the side surfaces 12a and 12b gradually changes to a perpendicular orientation relative to the bottom surface 11. Furthermore, even if an external force C is applied to the side surfaces 12a and 12b from the outside, the side flanges 2a and 2b disposed inside the sheet metal box body 10 function as a support mechanism for supporting the side surfaces 12a and 12b from the inside. This increases the rigidity of the side surfaces 12 of the sheet metal box body 10 after the sheet metal box cover 1 is attached to the sheet metal box body 10. As a result, resistance to external force C applied to the side surface portion 12 from the outside is ensured, and deformation of the sheet metal box body 10 can be prevented.

[0051] 8, the second front flanges 4a, 4b of the sheet metal box cover 1 are disposed inside the sheet metal box body 10, while the first front flanges 3a, 3b, 3c, 3d of the sheet metal box cover 1 are disposed outside the sheet metal box body 10. Therefore, the upper end portions 125 of the side portions 12c, 12d of the sheet metal box body 10 are supported from both the outside and the inside by the first front flanges 3a, 3b, 3c, 3d and the second front flanges 4a, 4b, as shown in FIG. 8. As a result, the arrangement of the side portions 12c, 12d, which had been inclined toward the outside of the U-shape, is corrected so that they are perpendicular to the bottom portion 11. Furthermore, even when an external force C is applied to the side surface portions 12c, 12d from the outside, the second front flange portions 4a, 4b arranged inside the sheet metal box body 10 act as a support mechanism that supports the side surface portions 12c, 12d from the inside. This makes it possible to further increase the rigidity of the side surface portions 12 of the sheet metal box body 10 after the sheet metal box cover 1 is attached to the sheet metal box body 10. As a result, resistance to the external force C applied to the side surface portions 12 from the outside is ensured, and deformation of the sheet metal box body 10 can be prevented.

[0052] [Detailed description of the configuration of the sheet metal box body 10] Next, the configuration of the sheet metal box body 10 will be described in detail using Figures 9 and 10. The sheet metal box body 10 is made of a material with excellent thermal conductivity. The sheet metal box body 10 is formed by bending a sheet metal with excellent thermal conductivity, such as aluminum.

[0053] 9, the sheet metal box body 10 is composed of a first U-shaped member 10A and a second U-shaped member 10B. The first U-shaped member 10A and the second U-shaped member 10B are each formed by bending sheet metal such as aluminum into a U-shape.

[0054] As shown in FIG. 9, the first U-shaped member 10A has opposing side surfaces 12a and 12b among the four side surfaces 12 of the sheet metal box main body 10. The first U-shaped member 10A also has a bottom surface 11a. The bottom surface 11a has a circular or approximately circular shape in a plan view. The bottom surface 11a is arranged so as to be parallel to the X-axis direction and the Y-axis direction. Opposing side surfaces 12a and 12b are respectively erected upward in the upward direction Z1 from both ends of the bottom surface 11a in the X-axis direction. The bottom surface 11a is sometimes referred to as a first heat sink base. The side surfaces 12a and 12b are sometimes referred to as first heat sink fins.

[0055] As shown in FIG. 9, the second U-shaped member 10B has opposing side surfaces 12c and 12d among the four side surfaces 12 of the sheet metal box body 10. The second U-shaped member 10B also has a bottom surface 11b. The bottom surface 11b has a rectangular or substantially rectangular shape in a plan view. The bottom surface 11b is arranged parallel to the X-axis direction and the Y-axis direction. Opposing side surfaces 12c and 12d are erected from both ends of the bottom surface 11b in the Y-axis direction, respectively, facing upward in the Z1 direction. The bottom surface 11b is sometimes referred to as a second heat sink base. The side surfaces 12c and 12d are sometimes referred to as second heat sink fins.

[0056] The sheet metal box body 10 is formed into a box shape by placing the bottom surface 11b of the second U-shaped member 10B on the bottom surface 11a of the first U-shaped member 10A. Therefore, the bottom surface 11 of the sheet metal box body 10 is configured by stacking the bottom surface 11a and the bottom surface 11b.

[0057] 9, the side surfaces 12a and 12b of the first U-shaped member 10A and the side surfaces 12c and 12d of the second U-shaped member 10B are arranged in directions perpendicular to each other. In other words, the width direction of the side surfaces 12a and 12b of the first U-shaped member 10A is the Y-axis direction, and the width direction of the side surfaces 12c and 12d of the second U-shaped member 10B is the X-axis direction, and the respective width directions are arranged in directions intersecting each other.

[0058] The side surfaces 12a and 12b of the first U-shaped member 10A and the side surfaces 12c and 12d of the second U-shaped member 10B are arranged so that their upright directions face the same direction, resulting in an open top surface of the box shape.

[0059] In this way, when assembling the sheet metal box body 10, the bottom surface 11b of the second U-shaped member 10B is placed on the bottom surface 11a of the first U-shaped member 10A. As a result, when the first U-shaped member 10A and the second U-shaped member 10B are combined to form the box shape shown in Fig. 10, the side surfaces 12a and 12b of the first U-shaped member 10A and the side surfaces 12c and 12d of the second U-shaped member 10B are positioned adjacent to each other. In addition, the top surface of the box shape is open.

[0060] In the first embodiment, the sheet metal box body 10 is formed by combining a first U-shaped member 10A and a second U-shaped member 10B made of sheet metal. Fig. 10 shows a sheet metal box 40 formed by combining the first U-shaped member 10A and the second U-shaped member 10B. Fig. 10 also shows the sheet metal box 40 with a sheet metal box cover 1 attached to the sheet metal box body 10. The sheet metal box cover 1 is sometimes called a heat sink cover.

[0061] As described above, according to the first embodiment, the sheet metal box cover 1 is configured to position the side flanges 2a, 2b inside the side flanges 12a, 12b by utilizing the characteristic that the side flanges 12a, 12b of the sheet metal box body 10 expand in a direction away from each other. That is, when the sheet metal box cover 1 is attached to the sheet metal box body 10, as shown in FIG. 4 , the upper ends 125, which are the free ends of the side flanges 12a, 12b of the sheet metal box body 10, expand in a direction away from each other. Therefore, the side flanges 2a, 2b of the sheet metal box cover 1 are naturally guided by the inner walls of the side flanges 12a, 12b of the sheet metal box body 10 and inserted into the sheet metal box body 10. Therefore, the side flanges 2a, 2b of the sheet metal box cover 1 can be easily inserted into the sheet metal box body 10.

[0062] Furthermore, the sheet metal box cover 1 is configured to position the second front flanges 4a, 4b inside the side surfaces 12c, 12d of the sheet metal box body 10, taking advantage of the fact that the side surfaces 12c, 12d of the sheet metal box body 10 expand in a direction away from each other. That is, when the sheet metal box cover 1 is attached to the sheet metal box body 10, as shown in FIG. 5 , the upper ends 125, which are the free ends of the side surfaces 12c, 12d of the sheet metal box body 10, expand in a direction away from each other. Therefore, the second front flanges 4a, 4b of the sheet metal box cover 1 are naturally guided by the inner walls of the side surfaces 12c, 12d of the sheet metal box body 10 and inserted into the sheet metal box body 10. This allows the second front flanges 4a, 4b of the sheet metal box cover 1 to be easily inserted into the sheet metal box body 10.

[0063] In this way, the sheet metal box cover 1 is attached to the sheet metal box body 10, so that the sheet metal box cover 1 can be easily attached to the sheet metal box body 10.

[0064] Furthermore, when the sheet metal box cover 1 is attached to the sheet metal box body 10, the side flanges 2a, 2b are fixed to the side surfaces 12a, 12b that constitute the sheet metal box body 10 with fasteners 80 such as screws. Therefore, as shown in Fig. 7, even when an external force C is applied to the side surfaces 12a, 12b that constitute the sheet metal box body 10, the side flanges 2a, 2b act as a support mechanism that supports the side surfaces 12a, 12b from the inside. This ensures the rigidity of the side surfaces 12a, 12b and prevents deformation of the side surfaces 12a, 12b.

[0065] 5, the length L1 from point O, which is the center of the top surface portion 5, to the outer surface portions 31 of the first front flanges 3a, 3b, 3c, and 3d is longer than the length L2 from point O, which is the center of the top surface portion 5, to the outer surface portions 41 of the second front flanges 4a and 4b. The absolute value of the difference between length L1 and length L2 is the same as the plate thickness of the side surfaces 12c and 12d that constitute the sheet metal box body 10. Therefore, when the sheet metal box cover 1 is attached to the sheet metal box body 10, the upper ends 125 of the side surfaces 12c and 12d are sandwiched between the first front flanges 3a, 3b, 3c, and 3d and the second front flanges 4a and 4b, as shown in FIG. That is, the upper end portions 125 of the side portions 12c and 12d are supported from the outside by the first front flanges 3a, 3b, 3c, and 3d, and from the inside by the second front flanges 4a and 4b. Therefore, as shown in FIG. 8, even when an external force C is applied to the side portions 12c and 12d constituting the sheet metal box body 10, the second front flanges 4a and 4b act as a support mechanism that supports the side portions 12c and 12d from the inside. Furthermore, the first front flanges 3a, 3b, 3c, and 3d act as a support mechanism that supports the side portions 12c and 12d from the outside. This ensures the rigidity of the side portions 12c and 12d, preventing deformation of the side portions 12c and 12d.

[0066] From the above, according to the sheet metal box cover 1 of embodiment 1, the work of attaching it to the sheet metal box main body 10 can be simplified and the rigidity of the side portions 12a, 12b, 12c, and 12d of the sheet metal box main body 10 can be ensured.

[0067] The sheet metal box 40 according to the first embodiment has the sheet metal box cover 1 described in the first embodiment, and therefore has the same effects as those described above. That is, the sheet metal box 40 according to the first embodiment simplifies the work of attaching the sheet metal box cover 1 to the sheet metal box body 10, and ensures the rigidity of the side surface portions 12a, 12b, 12c, and 12d of the sheet metal box body 10.

[0068] Embodiment 2 Fig. 11 is an exploded perspective view showing the configuration of a sheet metal box main body according to embodiment 2. Fig. 12 is a perspective view showing the configuration of a sheet metal box cover and a sheet metal box main body according to embodiment 2. The configuration of the sheet metal box cover 1 in embodiment 2 is the same as that in embodiment 1, so it is indicated by the same reference numerals and its description will be omitted here.

[0069] As shown in FIG. 11, the sheet metal box body 10 according to the second embodiment is a modified example of the sheet metal box body 10 according to the first embodiment. As in the first embodiment, the sheet metal box body 10 according to the second embodiment has a bottom surface 11 and four side surfaces 12 extending upward from the bottom surface 11 in the Z1 direction. Therefore, as shown in FIG. 12, the sheet metal box body 10 has a box-like shape with an opening 13 on the top surface. Also, as shown in FIG. 12, the sheet metal box cover 1 is attached so as to cover the top surface of the sheet metal box body 10. The difference between the first embodiment and the second embodiment is the number and shape of the members constituting the sheet metal box body 10. This will be explained in detail below.

[0070] As shown in FIG. 11, the sheet metal box body 10 is made up of four members: a first U-shaped member 10C, two L-shaped members 10D, and a second U-shaped member 10E.

[0071] In the second embodiment, the sheet metal box cover 1 and the sheet metal box body 10 are made of a material with excellent thermal conductivity, as in the first embodiment. The sheet metal box cover 1 and the sheet metal box body 10 are formed by bending a sheet metal with excellent thermal conductivity, such as aluminum.

[0072] As shown in FIG. 11, the second U-shaped member 10E has opposing mounting portions 12e and 12f. The second U-shaped member 10E also has a bottom surface portion 11c. The bottom surface portion 11c has a circular or approximately circular shape in a plan view. The bottom surface portion 11c is arranged so as to be parallel to the X-axis direction and the Y-axis direction. Opposing mounting portions 12e and 12f are erected from both ends of the bottom surface portion 11c in the X-axis direction, respectively, facing upward in the Z1 direction. The bottom surface portion 11c is sometimes referred to as a first heat sink base. The mounting portions 12e and 12f are fixed to the light source unit 52 of the lighting fixture 50 by means of an arm 22 (see FIG. 2) and fasteners 82 (see FIG. 2), such as screws.

[0073] As shown in FIG. 11 , the first U-shaped member 10C has opposing side portions 12g and 12h. The side portions 12g and 12h form the side portion 12 of the sheet metal box main body 10. The first U-shaped member 10C also has a bottom portion 11d. The bottom portion 11d has a rectangular or substantially rectangular shape in a plan view. The bottom portion 11d is arranged parallel to the X-axis direction and the Y-axis direction. Opposing side portions 12g and 12h extend upward in the Z1 direction from both ends of the bottom portion 11d in the X-axis direction. The bottom portion 11d is sometimes referred to as a second heat sink base. The side portions 12g and 12h are sometimes referred to as first heat sink fins.

[0074] As shown in FIG. 11, the pair of L-shaped members 10D have opposing side surfaces 12i and 12j. The side surfaces 12i and 12j, together with the side surfaces 12g and 12h, form the side surface 12 of the sheet metal box body 10. Each of the L-shaped members 10D also has a bottom surface 11e. The bottom surface 11e has a rectangular or substantially rectangular shape in a plan view. The bottom surface 11c is disposed parallel to the X-axis direction and the Y-axis direction. The side surfaces 12i and 12j each extend upward in the Z1 direction from one end of the bottom surface 11e in the Y-axis direction. The bottom surface 11e is sometimes referred to as a third heat sink base. The side surfaces 12i and 12j are sometimes referred to as second heat sink fins.

[0075] 11, bottom surface portions 11d and 11e are placed on bottom surface portion 11c. At this time, side surface portions 12g and 12h of first U-shaped member 10C are positioned inside mounting portions 12e and 12f of second U-shaped member 10E in the X-axis direction. In addition, side surface portions 12i and 12d of a pair of L-shaped members 10D are positioned in a direction perpendicular to side surface portions 12g and 12h of first U-shaped member 10C.

[0076] In the second embodiment, the bottom surface portions 11c, 11d, and 11e constitute the bottom surface portion 11 of the sheet metal box body 10. The side surface portions 12g, 12h, 12i, and 12j constitute the side surface portion 12 of the sheet metal box body 10.

[0077] Thus, in the second embodiment, the sheet metal box main body 10 is formed by combining a first U-shaped member 10C, two L-shaped members 10D, and a second U-shaped member 10E. In addition, with the bottom surface portions 11d and 11e placed on the bottom surface portion 11c, the bottom surface portions 11d and 11e are fixed to the bottom surface portion 11c with fasteners such as screws (not shown), thereby forming the sheet metal box main body 10 as shown in FIG.

[0078] As shown in an example in embodiment 2, the sheet metal box body 10 is not limited to the configuration shown in embodiment 1, and may have other configurations as long as it has a box-like shape with an open top. Even in such cases, the sheet metal box cover 1 shown in embodiment 1 can be used in common. In this way, the sheet metal box cover 1 shown in embodiment 1 can be applied to boxes of other configurations as long as it has a box-like shape with an open top, and is therefore versatile. Furthermore, in either case, the sheet metal box cover 1 and the sheet metal box 40 having it can achieve the same effects as those of embodiment 1.

[0079] Embodiment 3 Fig. 13 is an exploded perspective view showing the configuration of a lighting fixture according to embodiment 3. As shown in Fig. 13, lighting fixture 50 has frame 51, light source unit 52, movable frame 53, a heat sink formed from sheet metal box 40, a power supply unit (not shown), and a lighting device (not shown).

[0080] Lighting fixture 50 is a recessed lighting device that is fixed to a mounting portion such as a ceiling. A frame 51 of lighting fixture 50 is fixed to a mounting portion such as a ceiling with a mounting fixture 54 such as a mounting spring. Frame 51 is formed in a circular ring shape. Lighting fixture 50 is not limited to a recessed lighting device that is fixed to a mounting portion, and may be any lighting device that has a heat dissipation member that dissipates heat generated from light source unit 52.

[0081] The light source unit 52 is disposed inside the frame 51 and includes a light source that emits light toward the illumination space and a reflector. The light source is, for example, an LED element. The illumination space is, for example, an indoor space. A portion of the light emitted from the light source is emitted directly toward the illumination space and illuminates the illumination space. Another portion of the light emitted from the light source is reflected by the reflector and then illuminates the illumination space. The reflector is, for example, formed in a truncated cone shape.

[0082] The movable frame 53 allows the light source unit 52 to rotate relative to the frame 51. The movable frame 53 causes the light source unit 52 to rotate in the direction of arrow D, that is, in the circumferential direction of the frame 51. The movable frame 53 is formed in an annular shape.

[0083] The heat sink is configured from the sheet metal box 40 described in the first and second embodiments. The heat sink dissipates heat generated by the light source unit 52.

[0084] Inside the heat sink, there are arranged a power supply unit that supplies electric power, and a lighting device that supplies electric power from the power supply unit to the light source unit 52 to cause the light source of the light source unit 52 to emit light. However, this is not the only case, and at least one of the power supply unit and the lighting device may be arranged inside the heat sink.

[0085] Lighting fixture 50 according to the third embodiment includes sheet metal box 40 as described in the first and second embodiments, and therefore provides the same effects as those of the first and second embodiments. [Explanation of symbols]

[0086] 1 Cover for sheet metal box, 2 Side flange, 2a Side flange, 2aa tip, 2b Side flange, 2bb Tip, 3 1st front flange, 3a 1st front flange, 3aa tip, 3b 1st front flange, 3bb Tip, 3c 1st front flange, 3cc tip, 3d 1st front flange, 3dd tip, 4 2nd front flange, 4a 2nd front flange, 4aa tip, 4b 2nd front flange, 4bb tip, 5 top surface, 5a 1st end, 5b 1st end, 5c 2nd end, 5d 2nd end, 5e recess, 10 sheet metal box body, 10A 1st U-shaped member, 10B 2nd U-shaped member, 10C 1st U-shaped member, 10D L-shaped member, 10E Second U-shaped member, 11 bottom surface portion, 11a bottom surface portion, 11b bottom surface portion, 11c bottom surface portion, 11d bottom surface portion, 11e bottom surface portion, 12 side surface portion, 12a side surface portion, 12b side surface portion, 12c side surface portion, 12d side surface portion, 12e mounting portion, 12f mounting portion, 12g side surface portion, 12h side surface portion, 12i side surface portion, 12j side surface portion, 13 opening portion, 13a upper edge portion, 20 screw hole, 22 arm, 31 outer surface portion, 40 sheet metal box, 41 outer surface portion, 50 lighting fixture, 51 frame, 52 light source portion, 53 movable frame, 54 mounting fixture, 80 fixing fixture, 81 fixing fixture, 82 fixing fixture, 110 screw hole, 120 screw hole, 121 screw hole, 123 Groove, 125 upper end, A arrow, B arrow, C external force, D arrow, Z1 upward, Z2 downward.

Claims

1. An upper surface portion formed in a rectangular shape as a whole in a plan view; side flanges extending from first ends, which are two opposing sides of the four sides of the top surface portion, toward a first direction intersecting the top surface portion; a front flange portion extending from each of second ends, which are two other opposing sides of the top surface portion, toward the first direction; and Equipped with the second end extends in a second direction intersecting the first direction, and the first end extends in a third direction intersecting the first direction and the second direction; The front flange portion is Two first front flanges are spaced apart from each other and arranged side by side in the second direction at each of the second ends; At each of the second ends, a recess is formed between the two first front flanges arranged side by side in the second direction, and a second front flange is arranged in the recess; and the recessed portion is formed in each of the second end portions so as to be recessed inward of the upper surface portion in the third direction from a portion of the second end portion to which the first front flange portion is connected, an outer surface portion of the second front flange portion is recessed inwardly of the upper surface portion in the third direction relative to an outer surface portion of the first front flange portion; A length D1 of the first front flange portion in the first direction is shorter than a length D2 of the second front flange portion in the first direction. Sheet metal box cover.

2. The length D2 of the second front flange portion in the first direction is shorter than or equal to the length D3 of the side flange portion in the first direction. The cover for a sheet metal box according to claim 1.

3. An upper surface portion formed in a rectangular shape as a whole in a plan view; side flanges extending from first ends, which are two opposing sides of the four sides of the top surface portion, toward a first direction intersecting the top surface portion; a front flange portion extending from each of second ends, which are two other opposing sides of the top surface portion, toward the first direction; and Equipped with the second end extends in a second direction intersecting the first direction, and the first end extends in a third direction intersecting the first direction and the second direction; The front flange portion is Two first front flanges are spaced apart from each other and arranged side by side in the second direction at each of the second ends; At each of the second ends, a recess is formed between the two first front flanges arranged side by side in the second direction, and a second front flange is arranged in the recess; and the recessed portion is formed in each of the second end portions so as to be recessed inward of the upper surface portion in the third direction from a portion of the second end portion to which the first front flange portion is connected, an outer surface portion of the second front flange portion is recessed inwardly of the upper surface portion in the third direction relative to an outer surface portion of the first front flange portion; The length D2 of the second front flange portion in the first direction is shorter than or equal to the length D3 of the side flange portion in the first direction. Sheet metal box cover.

4. The outer surface of the first front flange portion and the outer surface of the second front flange portion are arranged to be parallel to each other. The cover for a sheet metal box according to any one of claims 1 to 3.

5. a box-shaped sheet metal box body having an opening on its top surface; The sheet metal box cover according to any one of claims 1 to 4, which is detachably attached to cover the opening of the sheet metal box body; Equipped with Sheet metal box.

6. a frame installed on the mounting portion; a light source unit disposed inside the frame and having a light source that irradiates light toward an illumination space; a movable frame that rotates the light source unit relative to the frame; a heat sink configured as the sheet metal box according to claim 5, which dissipates heat generated by the light source unit; a power supply unit that supplies power; a lighting device that supplies power from the power supply unit to the light source unit to cause the light source of the light source unit to emit light; A lighting fixture equipped with

Images