Lighting device

Abstract

To provide a compact lighting device.SOLUTION: In the lighting device 1 provided with a case body 3 arranged in a ceiling space in a state installed on a ceiling, a light source unit 5 housed inside the case body 3, and a cover 4 having a front glass plate 42 transmitting light from the light source unit 5 toward the inside of a room, the light source unit 5 is provided with an LED substrate mounted with a plurality of LED chips. The top plate of the casing of the light source unit 5 and the top plate 35 of the case body 3 are connected by a flat plate-like connecting bracket 7 extending in parallel to the extending direction of the top plates. This makes it possible to reduce the size of lighting apparatus 1. In addition, with the miniaturization of the lighting device 1, the weight of the lighting device 1 can be reduced, and the installation workability can be improved.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a lighting device. In particular, the present invention relates to an improvement for miniaturizing a lighting device.

Background Art

[0002] Conventionally, as a lighting device applied to a clean room, a painting booth, etc., a ceiling-embedded lighting device with increased safety and explosion protection has been known (for example, refer to Patent Document 1).

[0003] The lighting device disclosed in Patent Document 1 includes a rectangular box-shaped case body disposed in the ceiling space, and a light source unit that is housed inside the case body and irradiates light indoors. In addition, a straight tube type LED lamp is adopted as the light source unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, when installing ceiling-mounted lighting fixtures (hereinafter sometimes simply referred to as lighting fixtures), the space above the ceiling must be large enough to accommodate the fixture's case. However, until now, space-saving measures in the space above the ceiling by miniaturizing the lighting fixtures have been largely overlooked. Furthermore, when installing ceiling-mounted lighting fixtures in the ceiling of a newly constructed building, such as a new factory, the space above the ceiling must be large enough to accommodate the fixture (the fixture's case), requiring the building design to take the height of the lighting fixture into consideration. In other words, there has been the inconvenience of having to consider the external dimensions (size) of the lighting fixture when designing a new building. For this reason, there has been a demand for lighting fixtures that have been miniaturized to the point where their size hardly needs to be considered when designing a new building. Moreover, miniaturization of lighting fixtures is required not only when installing lighting fixtures in the ceiling of a new building, but also when installing new lighting fixtures in the ceiling of an existing building (replacing existing lighting fixtures with new ones) for ease of installation. Furthermore, the demand for miniaturization of such lighting devices is not limited to ceiling-mounted lighting fixtures, but is also occurring for lighting devices installed in various locations.

[0006] This invention has been made in view of the above, and its objective is to provide a miniaturized lighting device. [Means for solving the problem]

[0007] The present invention provides a solution for achieving the above objective, which is based on a lighting device comprising a case body arranged in a predetermined housing space when installed, a light source unit housed inside the case body, and a light-transmitting panel that transmits light from the light source unit toward the space to be illuminated. The lighting device is configured such that the light source unit has an LED substrate on which a plurality of LED chips are mounted, the upper end of the light source unit is close to the top plate of the case body, the lower end of the light source unit is close to the upper surface of the light-transmitting panel, the light source unit comprises a casing that houses the LED substrate, the casing has a top plate that extends parallel to the top plate of the case body, the top plate of the casing and the top plate of the case body are connected by a flat connecting bracket that extends parallel to the direction of extension of the top plates, the connecting bracket has a first connecting portion located on the upper side of the top plate of the casing and connected to the top plate by bolts, When the width direction of the lighting device is the X direction and the length direction is the Y direction, From the upper side of the top plate of the aforementioned casing In the aforementioned Y direction It is characterized by having a second connecting portion that is connected to the top plate of the case body by bolts when it is detached.

[0008] Furthermore, if the lighting device is a ceiling-mounted type, the predetermined dwelling space corresponds to the space above the ceiling of the building, and the space to be illuminated corresponds to the indoors.

[0009] As a result of the aforementioned specifications, the height of the case body can be reduced to approximately the same height as the light source unit (a light source unit that has been made thinner by having an LED board on which multiple LED chips are mounted). This makes it possible to miniaturize the lighting device. Furthermore, as the lighting device is miniaturized, its weight can also be reduced, improving ease of installation. Moreover, as the lighting device is made lighter, it is also possible to make the support brackets (such as mounting hardware) for supporting the lighting device smaller and lighter, making it possible to miniaturize and lighten the entire lighting device, including these support brackets.

[0012] Furthermore, of the case body, the light-transmitting panel, and the light source unit, only the light source unit has an explosion-proof structure.

[0013] When lighting equipment is applied to clean rooms, paint booths, etc., explosion-proof construction is generally required for the lighting equipment. In this case, by applying an explosion-proof structure (e.g., a resin-filled explosion-proof structure) to the light source unit, it becomes unnecessary to adopt an explosion-proof structure for the case body and light-transmitting panel. As a result, there are no particular restrictions on the structure, shape, material, etc. of the case body and light-transmitting panel. In other words, it becomes possible to adopt structures, shapes, materials, etc. that allow for further miniaturization and weight reduction of the case body and light-transmitting panel. Furthermore, the configuration of the case body and light-transmitting panel can be customized according to the requirements of the lighting equipment's installation location.

[0014] Furthermore, the cover, including the light-transmitting panel, is detachably attached to the case body by a spring hinge. The spring hinge comprises a coil portion supported by the cover and a locking leg portion continuous with the coil portion. When the cover is attached to the case body, the locking leg portion is locked to the spring hinge locking fitting provided on the case body by pressing against it. When removing the cover from the case body, pressure is applied to the locking leg portion in the opposite direction to the pressing direction to release the locking of the locking leg portion from the spring hinge locking fitting. A cover member made of an elastic material is attached to the tip of the locking leg portion.

[0015] When the cover is removed from the case body and the pressure applied to the locking leg of the spring hinge is released, if the restoring force that causes the locking leg to return to its original shape is large, the locking leg may elastically deform significantly toward the light-transmitting panel and collide with the light-transmitting panel. In particular, in this invention, because the lighting device is miniaturized, the space for arranging the spring hinge is limited, and when the cover is removed from the case body, there is a high possibility that the locking leg of the spring hinge must be elastically deformed significantly, and as a result, the restoring force tends to be large. In this solution, since a cover member is attached to the tip of the locking leg of the spring hinge, even if the locking leg is elastically deformed significantly toward the light-transmitting panel, the cover member will collide with the light-transmitting panel, preventing the locking leg from directly colliding with the light-transmitting panel, thus preventing damage to the light-transmitting panel.

[0016] Furthermore, the lighting device also includes the following renewal plate. In other words, the lighting device is a ceiling-mounted type, and the case body is inserted into a recessed opening formed in the ceiling panel, and includes a renewal plate used when the shape of the existing recessed opening is larger than the shape of the case body, wherein the external shape of the renewal plate is larger than the shape of the existing recessed opening, and the shape of the fitting opening provided in the renewal plate is larger than the shape of the case body and smaller than the external shape of the cover including the light-transmitting panel.

[0017] When replacing an existing lighting fixture with a new lighting fixture according to the present invention, the existing lighting fixture is larger than the new lighting fixture. Therefore, a relatively large recessed opening is formed in the ceiling panel according to the shape of the case body of the existing lighting fixture. For this reason, if one simply removes the existing lighting fixture from the ceiling panel and attempts to install the new lighting fixture, a gap may be created between the new lighting fixture and the edge of the recessed opening, or the new lighting fixture may not be able to be installed at all. In view of this, the present solution makes it possible to replace an existing lighting fixture with a new one without creating a gap between the new lighting fixture and the edge of the recessed opening by using the aforementioned renewal plate. [Effects of the Invention]

[0018] In this invention, a lighting device comprising a case body, a light source unit, and a translucent panel is configured such that the upper end of the light source unit is close to the top plate of the case body, and the lower end of the light source unit is close to the upper surface of the translucent panel. This allows for miniaturization of the lighting device. Furthermore, the miniaturization of the lighting device also allows for weight reduction, improving ease of installation. [Brief explanation of the drawing]

[0019] [Figure 1] This is a perspective view of the lighting device according to the first embodiment, seen from below. [Figure 2] This is a perspective view of the lighting device according to the first embodiment, viewed from above. [Figure 3] This is a cross-sectional view along the line III-III in Figure 2. [Figure 4] This is a cross-sectional view along the line IV-IV in Figure 2. [Figure 5] This is a cross-sectional view showing the cover suspension structure in a lighting device according to the first embodiment. [Figure 6] This figure shows a spring hinge and its surrounding parts in a lighting device according to the first embodiment. [Figure 7]It is a cross-sectional view showing the internal structure of a light source unit in a lighting device according to the first embodiment. [Figure 8] It is a perspective view showing the support structure of a light source unit in a lighting device according to the first embodiment. [Figure 9] It is a cross-sectional view showing a conventional lighting device in which a straight tube type LED lamp is adopted as a light source unit. [Figure 10] It is a view showing a spring hinge and its peripheral part in a conventional lighting device. [Figure 11] FIG. 11(a) is a view corresponding to FIG. 6 for explaining the cover removal operation, and FIG. 11(b) is a view showing an example of the deformed state of the spring hinge when the pressing force on the spring hinge is released after the cover is removed. [Figure 12] It is a perspective view of a lighting device according to the second embodiment seen from below. [Figure 13] It is a cross-sectional view taken along the line XIII-XIII in FIG. 12. [Figure 14] FIG. 14(a) is a cross-sectional view showing the support structure of the case body in a lighting device according to the second embodiment, and FIG. 14(b) is a cross-sectional view showing the support structure of the cover in a lighting device according to the second embodiment. 2] [Figure 15] It is a perspective view showing the support structure of a light source unit in a lighting device according to the second embodiment. [Figure 16] It is a perspective view for explaining the operation when replacing an existing lighting device with the lighting device according to the present invention. [Figure 17] It is a perspective view of a new lighting device to be replaced from an existing lighting device seen from above.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described based on the drawings. In this embodiment, the case where the lighting device according to the present invention is installed on the ceiling surface of a room such as a clean room will be described as an example.

[0021] -First Embodiment- First, the first embodiment will be described. Figure 1 is a perspective view of the lighting device 1 according to this embodiment, seen from below. Figure 2 is a perspective view of the lighting device 1, seen from above. Figure 3 is a cross-sectional view along line III-III in Figure 2. Figure 4 is a cross-sectional view along line IV-IV in Figure 2. Figure 5 is a cross-sectional view showing the suspension structure of the cover 4 in the lighting device 1. In the following description, as shown in Figure 1, the width direction of the lighting device 1 will be referred to as the X direction, the longitudinal direction as the Y direction, and the height direction as the Z direction.

[0022] The lighting device 1 is of the increased safety explosion-proof type. Specifically, the light source unit 5 housed inside the housing 2, which will be described later, has a resin-filled explosion-proof structure. An emergency light unit may also be housed inside the housing 2. Furthermore, the lighting device 1 is dustproof and waterproof and is configured to comply with, for example, IP65 as its protection class (IP code). The lighting device 1 is a ceiling-mounted type, and when installed on the ceiling, it is supported by suspension bolts B, B, ... (shown as dashed lines in Figure 2) on beams in the space above the ceiling and fitted into a recessed opening 101 formed in the ceiling panel 100 (see Figure 5).

[0023] As shown in Figures 1, 3, and 4, the lighting device 1 comprises a housing 2 and a light source unit 5, and is supported by the aforementioned suspension bolts B, B, ... via support brackets 35b, 35b, ... attached to the housing 2.

[0024] (Enclosure) As shown in Figures 1 to 4, the housing 2 comprises a case body 3 and a cover 4 that is detachably disposed on the lower side of the case body 3.

[0025] The case body 3 is made of, for example, steel plate and is formed in the shape of a rectangular box. The case body 3 may also be painted white. The case body 3 has a pair of side plates 31, 32 that extend in a direction perpendicular to the X direction and face each other, a pair of side plates 33, 34 that extend in a direction perpendicular to the Y direction and face each other, and a top plate 35 that spans between the upper ends of each of the side plates 31-34. As a result, the case body 3 is a rectangular box shape with an opening 36 on the bottom. Also, as shown in Figure 2, flat reinforcing panels 35a, 35a are attached to both sides of the top surface of the top plate 35 in the Y direction, and four support brackets 35b, 35b, ... are attached to the upper side of the reinforcing panels 35a by bolts B1, B1, ... which are inserted through the reinforcing panels 35a and the top plate 35. The suspension bolts B are inserted through bolt insertion holes provided in these support brackets 35b, 35b, ...

[0026] The cover 4 is detachably attached to the case body 3, and when the cover 4 is attached to the case body 3, the cover 4 is configured to close the opening 36. The cover 4 has a front frame 41 made of steel plate (for example, white painted steel plate) and a front glass plate 42 provided inside the front frame 41. The front frame 41 is not limited to steel plate, but may be made of aluminum alloy (for example, anodized) or stainless steel (for example, buffed).

[0027] The front frame 41 is provided with multiple spring hinges 43 (see Figure 6). The spring hinges 43 are provided for attaching the cover 4 to the case body 3. In this embodiment, two spring hinges 43 are provided on each side in the X direction along the Y direction (a total of four spring hinges 43 are provided). The number and position of the spring hinges 43 are not limited to this, and a configuration with three spring hinges 43 on each side in the X direction along the Y direction (a total of six spring hinges 43) is also possible. The mounting structure of the cover 4 using these spring hinges 43 will be described later.

[0028] As shown in Figure 1, the front glass panel 42 has a transparent glass portion 42a and frosted glass portions 42b, 42b. The transparent glass portion 42a is positioned opposite the light source unit 5 and is configured so that light emitted from the light source unit 5 passes through the transparent glass portion 42a. Therefore, this front glass panel 42 corresponds to the light-transmitting panel in this invention. The frosted glass portions 42b, 42b are provided on both outer sides of the transparent glass portion 42a in the direction along the Y direction and are provided to conceal a part of the interior of the case body 3. Alternatively, the entire front glass panel 42 may be made transparent without providing the frosted glass portions 42b.

[0029] Here, the mounting structure (suspension structure) of the cover 4 to the case body 3 will be explained using Figure 5. Figure 5 is a cross-sectional view (cross-sectional view along the X direction) showing the cover 4 attached to the case body 3 by a spring hinge 43.

[0030] As shown in Figure 5, the lower part of the side plate 31 of the case body 3 is provided with a first horizontal portion 31a extending horizontally outward from the lower end of the side plate 31, and a first vertical portion 31b extending slightly upward from the outer end of the first horizontal portion 31a. A packing 37 is housed in the area enclosed by the side plate 31, the first horizontal portion 31a, and the first vertical portion 31b. When the case body 3 is suspended and supported by the suspension bolts B, the first horizontal portion 31a and the first vertical portion 31b are located on the underside (indoor side) of the ceiling plate 100, and the packing 37 is in contact with the lower surface of the ceiling plate 100. This configuration is provided around the entire perimeter of the case body 3, preventing any gaps from forming between the case body 3 and the ceiling plate 100.

[0031] On the other hand, the front frame 41 has an external shape that is slightly larger than the opening shape of the recessed opening 101 in the ceiling panel 100, and when attached to the case body 3 by the spring hinge 43, the outer edge of the front frame 41 abuts against the lower surface of the ceiling panel 100.

[0032] The front frame 41 includes a second horizontal section 41a extending horizontally, an inclined section 41b extending diagonally upward from the outer end of the second horizontal section 41a, and a second vertical section 41c extending vertically upward by being folded back from the inner end of the second horizontal section 41a. A packing 44 is provided above the second horizontal section 41a, and when the cover 4 is attached to the case body 3, the packing 44 is sandwiched between the first horizontal section 31a and the second horizontal section 41a, thereby preventing a gap from forming between the case body 3 and the cover 4.

[0033] As shown in Figures 5 and 6 (views of the spring hinge 43 and its surrounding area from a direction along the X direction), a spring hinge support bracket 45 is screwed to the second vertical portion 41c. The spring hinge support bracket 45 comprises a third vertical portion 45a screwed to the second vertical portion 41c, a third horizontal portion 45b extending slightly horizontally from the lower end of the third vertical portion 45a toward the center of the cover 4, and a locking portion 45c that is continuous with the upper part of the third vertical portion 45a and engages with the coil portion 43a of the spring hinge 43. A packing 46 is disposed between the second horizontal portion 41a and the third horizontal portion 45b, and the outer periphery of the front glass plate 42 is elastically held by this packing 46.

[0034] As shown in Figure 6, the spring hinge 43 is constructed from a bent metal wire and comprises the aforementioned coil portion 43a and a pair of locking legs 43b, 43b that extend diagonally upward (diagonally upward toward the outside in the Y direction) from both sides (both sides in the Y direction) of the coil portion 43a. Meanwhile, a spring hinge locking fitting 47 is screwed to the side plate 31 of the case body 3. The spring hinge locking fitting 47 comprises a fourth vertical portion 47a screwed to the side plate 31, and a fourth horizontal portion 47b that extends horizontally from the lower end of the fourth vertical portion 47a toward the center of the case body 3. The central part of the fourth horizontal section 47b is provided with a notch 47c into which each locking leg 43b, 43b of the spring hinge 43 is inserted. As shown in Figure 6, when the cover 4 is attached to the case body 3, each locking leg 43b, 43b of the spring hinge 43 presses against the inner edge of the notch 47c of the spring hinge locking fitting 47. In other words, the left locking leg 43b in Figure 6 presses the inner edge of the notch 47c toward the left in the figure, and the right locking leg 43b in Figure 6 presses the inner edge of the notch 47c toward the right in the figure. This pressing force (the outward pressing force in the Y direction in Figure 6) acts as a force that pulls the cover 4 upward, thereby pressing the cover 4 toward the lower surface of the ceiling plate 100 or the case body 3, and a stable suspended support state is obtained.

[0035] (Light source unit) Figure 7 is a cross-sectional view showing the internal structure of the light source unit 5. Note that the internal structure of the light source unit 5 is not limited to that shown in Figure 7. As shown in Figure 7, the light source unit 5 includes a casing 51 having an opening 51a on its bottom side, a substrate mounting plate 52 attached to the casing 51 so as to cover the opening 51a, a case portion 53 attached to the substrate mounting plate 52, a light-emitting portion 54 housed inside the case portion 53, a power supply portion 55 housed inside the casing 51, and an outer plate portion 56 attached to the outside of the case portion 53.

[0036] The casing 51 is composed of an outer peripheral side portion 51b and a top plate 51c. The casing 51 is formed from, for example, an aluminum alloy. Each part of the casing 51 is ribbed to improve its strength.

[0037] The substrate mounting plate 52 is formed from, for example, a steel plate. The substrate mounting plate 52 is fixed to the lower end of the casing 51 by fastening members (not shown) at multiple locations on its peripheral edge.

[0038] The case portion 53 is composed of a right case portion 53a and a left case portion 53b, both formed from a light-transmitting material (for example, acrylic resin). Both the right case portion 53a and the left case portion 53b open upward and form a housing space α inside capable of accommodating the light-emitting portion 54. The right case portion 53a and the left case portion 53b are each fixed to the outer surface of the substrate mounting plate 52 at multiple locations on their peripheral edges by fastening members (not shown).

[0039] The light-emitting section 54 is composed of numerous LED chips 54b mounted on an LED substrate 54a and is housed within the housing space α of the case section 53. The energized parts of the light-emitting section 54, including the LED chips 54b, are covered with an insulating material such as a resin mold. This ensures an electrical insulation distance (e.g., insulating space distance, creepage distance, etc.) for the light-emitting section 54.

[0040] The power supply unit 55 supplies power from the commercial power source to the light-emitting unit 54 and a charging device (not shown). The power supply unit 55 includes a power supply board equipped with a power control circuit (not shown). The power supply unit 55 is fixed on both sides to the inner surface of the top plate 51c of the casing 51 by fastening members 55b via fixing brackets 55a. The energized parts of the power supply unit 55 are covered with insulating material such as resin molding. This ensures an electrical insulation distance for the power supply unit 55.

[0041] The outer panel 56 is made of a translucent material (for example, transparent glass) and is fixed to the lower end of the casing 51 by fastening members 55c via fixing brackets 56a at multiple locations on its peripheral edge. An annular sealing member 56b made of silicone sponge rubber or the like is provided between the casing 51 and the outer panel 56. The sealing member 56b prevents water, dust, etc. from entering the inside of the casing 51, ensuring the waterproof and dustproof properties of the casing 51 (for example, to the extent that it conforms to the IP65 protection rating).

[0042] As described above, the light source unit 5 has an increased safety explosion-proof structure, ensuring an electrical insulation distance between the light-emitting section 54 and the power supply section 55, as well as ensuring the waterproof and dustproof properties of the casing 51.

[0043] (Light source unit housing configuration) One of the features of this embodiment is the way in which the light source unit 5 is housed inside the housing 2.

[0044] Specifically, the upper end of the light source unit 5 is close to the top plate 35 of the case body 3, and the lower end of the light source unit 5 is close to the top surface of the front glass plate 42. This makes it possible to shorten the height dimension of the housing 2. The following describes the housing configuration of the light source unit 5 inside the housing 2.

[0045] Figure 8 is a perspective view showing the support structure of the light source unit 5 inside the case body 3. In Figure 8, the case body 3 and the reinforcing panel 35a are shown by dashed lines. Although Figure 8 shows the support structure of the light source unit 5 on one side in the Y direction, the support structure on the other side (the other side in the Y direction) is substantially the same. In this support structure on the other side, a similar support structure is employed below the terminal box TB (see Figures 2 and 3) which is located on the top plate 35 of the case body 3.

[0046] As shown in Figure 8, the top plate 51c of the casing 51 of the light source unit 5 and the top plate 35 of the case body 3 are connected via a connecting bracket 7. The connecting bracket 7 is made of metal and is flat in shape. One side in the Y direction (left side in Figure 8) is a first connecting portion 71 that connects to the top plate 51c of the casing 51 of the light source unit 5, and the other side in the Y direction (right side in Figure 8) is a second connecting portion 72 that connects to the top plate 35 and reinforcing panel 35a of the case body 3.

[0047] Specifically, the X-direction dimension of the first connecting portion 71 is set to be slightly shorter than the X-direction dimension of the second connecting portion 72. The X-direction dimension of this first connecting portion 71 is approximately the same as the X-direction dimension of the top plate 51c of the casing 51 of the light source unit 5. Bolt insertion holes are formed at two locations on both sides of the X-direction of this first connecting portion 71, and the top plate 51c of the casing 51 of the light source unit 5 is connected to the first connecting portion 71 by inserting bolts B2, B2 through these bolt insertion holes. More specifically, the portion of the top plate 51c of the casing 51 of the light source unit 5 on which the first connecting portion 71 of the connecting bracket 7 is placed does not have ribs, and this portion is flat. A flat connecting plate 73 is placed on top of this flat portion, and bolts B2, B2 are inserted through bolt insertion holes formed in the top plate 51c of the casing 51, the connecting plate 73, and the first connecting portion 71, thereby connecting the top plate 51c of the casing 51 of the light source unit 5 to the first connecting portion 71.

[0048] Furthermore, bolt insertion holes are formed in the second connecting portion 72 at two locations on both sides in the X direction, and the second connecting portion 72 is connected to the top plate 35 and reinforcing panel 35a of the case body 3 by inserting bolts B3 through these bolt insertion holes.

[0049] Because the top plate 51c of the casing 51 of the light source unit 5 and the top plate 35 of the case body 3 are connected via such a flat connecting bracket 7, there is only a gap between the top plate 51c of the casing 51 of the light source unit 5 and the top plate 35 of the case body 3 that is approximately the thickness of the connecting bracket 7. Also, as mentioned above, the lower end of the light source unit 5 is located close to the upper surface of the front glass plate 42.

[0050] With this configuration, the height of the case body 3 can be reduced to approximately the same height as the light source unit (a light source unit that has been made thinner by having an LED board 54a on which multiple LED chips 54b are mounted) 5. Therefore, the lighting device 1 can be made smaller.

[0051] Figure 9 is a cross-sectional view (corresponding to Figure 3) showing a conventional lighting device a that employs a straight-tube LED lamp b as a light source unit. As is clear from Figures 3 and 9, the lighting device 1 according to this embodiment has a significantly shorter height dimension of the housing 2 compared to the conventional lighting device a. For example, it is about 50% shorter than the conventional lighting device a (for example, about 100 mm). This value is not limited to this. In addition, the length dimension of this embodiment is shorter in both the X and Y directions compared to the conventional lighting device a. For example, the length dimension of the lighting device 1 according to this embodiment in the Y direction is about 30% shorter than the length dimension of the conventional lighting device a in the Y direction (for example, the length dimension in the Y direction is about 1000 mm, and the length dimension in the X direction is about 350 mm). This value is not limited to this. Along with the reduction in height and length, the lighting device 1 has also been made lighter. Specifically, the lighting device 1 according to this embodiment is about 40% lighter than the conventional lighting device a (for example, about 22 kg). This value is not limited to this. As a result of the weight reduction of the lighting device 1, it is also possible to reduce the size and weight of the brackets (the support bracket 35b mentioned above) that support the lighting device 1, thereby making the entire lighting device 1, including these brackets, smaller and lighter. Furthermore, by adopting an LED substrate 54a on which LED chips 54b are mounted as the light source, it is possible to improve the intrinsic energy consumption efficiency by about 30% compared to conventional lighting device a which uses a straight-tube LED lamp b as the light source. This value is not limited to this.

[0052] (Protective structure of the front glass panel) Another feature of this embodiment, as shown in Figure 6, is that each of the locking legs 43b, 43b of the spring hinge 43 is fitted with a cover member 43c, 43c made of an elastic material. This cover member 43c is made of rubber or resin and is molded, for example, into a bottomed cylindrical shape, and is fitted so as to cover at least the tip of each locking leg 43b, 43b. This is to prevent the front glass plate 42 from being damaged by the tips of the locking legs 43b, 43b directly colliding with the front glass plate 42 when removing the cover 4 from the case body 3. A detailed explanation follows below.

[0053] Figure 10 shows the spring hinge c and its surrounding area in a conventional lighting device a. In the conventional lighting device a, the height dimension of the case body d was relatively large, so sufficient space could be secured for the installation of the spring hinge c, and the inclination angle of the locking leg e of the spring hinge c with respect to the vertical was also relatively small. When removing the cover f from the case body d, the worker presses the locking legs e, e inward (towards the opposite locking leg e) (see arrow F in Figure 10), and with the distance between the pair of locking legs e, e shortened, the locking legs e, e are pulled out from the notch of the spring hinge locking fitting g. In this case, in the conventional lighting device a, since the inclination angle of the locking legs e with respect to the vertical is relatively small, the amount of deformation due to the pressing is small, and even when the pressing is released, the restoring force that causes the locking legs e, e to return to their original shape is small. In other words, the locking legs e,e do not undergo significant elastic deformation toward the front glass plate h.

[0054] However, in the lighting device 1 according to this embodiment, as mentioned above, the height dimension of the case body 3 is shortened, so sufficient space (space in the vertical direction) for arranging the spring hinge 43 cannot be secured. For this reason, the inclination angle of the locking legs 43b, 43b of the spring hinge 43 with respect to the vertical direction is large (extending in a direction closer to the horizontal direction compared to conventional ones). Specifically, the overall height dimension of the spring hinge 43 is shortened by bending a part of the locking legs 43b, 43b outward (outward in the Y direction). In addition, the tip portions of the locking legs 43b, 43b are provided with a bent portion 43d for suspending the cover 4 in a state where it is locked to the case body 3 (locked to the spring hinge locking fitting 47). Therefore, when removing the cover 4 from the case body 3, it is necessary to pull the cover 4 down from the case body 3 and temporarily lock the bent portion 43d to the fourth horizontal portion 47b of the spring hinge locking fitting 47, and then have the worker deform the locking legs 43b, 43b inward significantly (by the pressing force shown by arrow F in Figure 11(a)) to shorten the distance between the pair of locking legs 43b, 43b, and then pull the locking legs 43b, 43b out from the notch portion 47c of the spring hinge locking fitting 47. In this case, since the amount of deformation due to the pressing is large, when the pressing on the locking legs 43b, 43b is released after the cover 4 is removed from the case body 3, the restoring force of the locking legs 43b, 43b to return to their original shape is large, so the tips of the locking legs 43b, 43b (the tips of the bent portions 43d) may elastically deform significantly toward the front glass plate 42 and collide with the front glass plate 42. In this embodiment, since cover members 43c, 43c are attached to the tips (bent portions 43d) of each locking leg 43b, 43b of the spring hinge 43, even if the locking legs 43b, 43b are elastically deformed significantly toward the front glass plate 42, as shown in Figure 11(b), the cover members 43c will collide with the front glass plate 42 (because the tips of the metal locking legs 43b, 43b will not directly collide with the front glass plate 42), thus preventing damage to the front glass plate 42.

[0055] (Effects of the embodiment) As described above, in this embodiment, the upper end of the light source unit 5 and the top plate 35 of the case body 3 are in close proximity, and the lower end of the light source unit 5 and the upper surface of the front glass plate 42 are in close proximity. This makes it possible to shorten the height dimension of the housing 2 and to miniaturize the lighting device 1. As a result, space in the ceiling space can be saved. In addition, with the miniaturization of the lighting device 1, the weight of the lighting device 1 can also be reduced, improving ease of installation.

[0056] Furthermore, in this embodiment, cover members 43c, 43c made of elastic material are attached to the tips of each locking leg portion 43b, 43b of the spring hinge 43. As a result, even if the locking legs 43b, 43b undergo significant elastic deformation toward the front glass plate 42 when the cover 4 is removed from the case body 3, the cover members 43c will collide with the front glass plate 42, thereby preventing damage to the front glass plate 42.

[0057] Furthermore, in this embodiment, since the light source unit 5 is fitted with an explosion-proof structure (resin-filled explosion-proof structure), it is no longer necessary to adopt an explosion-proof structure for the housing 2. As a result, there are no particular restrictions on the structure, shape, material, etc. of the case body 3 and cover 4 that constitute the housing 2. In other words, it becomes possible to adopt a structure, shape, material, etc. that allows for further miniaturization and weight reduction of the case body 3 and cover 4. In addition, the configuration of the housing 2 can be customized according to the requirements of the installation location of the lighting device 1, thereby expanding the range of applications for the lighting device 1.

[0058] -Second Embodiment- Next, a second embodiment will be described. In this embodiment, the support structures of the case body 3 and cover 4 in the lighting device 1 differ from those of the first embodiment described above. Specifically, the case body 3 is bolted to the ceiling plate 100, and the cover 4 is bolted to the case body 3. The other configurations are substantially the same as those of the first embodiment described above, so here we will mainly describe the differences from the first embodiment.

[0059] Figure 12 is a perspective view of the lighting device 1 according to this embodiment, taken from below. Figure 13 is a cross-sectional view along the line XIII-XIII in Figure 12. Figure 14(a) is a cross-sectional view showing the support structure of the case body 3, and Figure 14(b) is a cross-sectional view showing the support structure of the cover 4. Figures 14(a) and 14(b) differ in the position of the cross-section in the Y direction. In this embodiment, the support structure of the case body 3 shown in Figure 14(a) is provided at multiple locations (for example, 6 locations) along the Y direction on both sides of the lighting device 1 in the X direction, and the support structure of the cover 4 shown in Figure 14(b) is provided at multiple locations (for example, 4 locations) along the Y direction on both sides of the lighting device 1. In each figure, the same reference numerals are used for components that are the same as those in the first embodiment described above, and their descriptions are omitted.

[0060] As shown in Figure 14(a), the lower part of the side plate 31 of the case body 3 is provided with a first horizontal section 31a and a first vertical section 31b, similar to the first embodiment described above. In addition, a fifth vertical section 31c extends upward from the middle section of the first horizontal section 31a in the X direction.

[0061] A reinforcing bracket 102 with an L-shaped cross section is positioned along the opening edge of the recessed opening 101 of the ceiling panel 100 on the upper surface of the opening edge of the recessed opening 101. A bolt B4 is inserted from below through bolt insertion holes formed in the first horizontal section 31a of the case body 3, the ceiling panel 100, and the reinforcing bracket 102, and the bolt B4 is screwed into a nut N provided on the upper part of the reinforcing bracket 102, thereby attaching the case body 3 to the ceiling panel 100. A packing 37 is housed in the area enclosed by the side plate 31, the first horizontal section 31a, and the fifth vertical section 31c, and when the case body 3 is attached to the ceiling panel 100, the packing 37 is sandwiched between the ceiling panel 100 and the first horizontal section 31a. This configuration is provided around the entire perimeter of the case body 3, preventing any gaps from forming between the case body 3 and the ceiling panel 100.

[0062] On the other hand, as shown in Figure 14(b), the front frame 41 includes a second horizontal section 41a extending horizontally, a sixth vertical section 41d extending upward from the outer end of the second horizontal section 41a, and a seventh vertical section 41e extending upward from the inner end of the second horizontal section 41a. Reinforcement members 41f and 41g are joined to the second horizontal section 41a and the sixth vertical section 41d, respectively. A packing 48 is provided between the sixth vertical section 41d and the reinforcement member 41g, and this packing 48 abuts against the lower surface of the ceiling panel 100, preventing a gap from forming between the ceiling panel 100 and the front frame 41. A packing 49 is also provided between the seventh vertical section 41e and the reinforcement member 41f, and this packing 49 elastically holds the outer periphery of the front glass panel 42.

[0063] A support bracket 38 for supporting the front frame 41 is welded to the lower surface of the first horizontal section 31a. A bolt B5 is inserted from below through bolt insertion holes formed in the horizontal section 38a and the second horizontal section 41a, which are located at the bottom of the support bracket 38. The front frame 41 is attached to the case body 3 by screwing the bolt B5 into a nut N1 provided on the horizontal section 38a. As a result, the head of the bolt B5 faces into the room (see Figures 12 and 13), and the cover 4 can be removed from the case body 3 by removing the bolt B5.

[0064] In this embodiment as well, the upper end of the light source unit 5 and the top plate 35 of the case body 3 are in close proximity, and the lower end of the light source unit 5 and the upper surface of the front glass plate 42 are in close proximity, thereby making it possible to shorten the height dimension of the housing 2.

[0065] Figure 15 is a perspective view showing the support structure of the light source unit 5 inside the case body 3. In Figure 15, as in Figure 8 mentioned above, the case body 3 and the reinforcing panel 35a are shown by dashed lines. Also, although Figure 15 shows the support structure of the light source unit 5 on one side in the Y direction, the support structure on the other side (the other side in the Y direction) is substantially the same.

[0066] As shown in Figure 15, the top plate 51c of the casing 51 of the light source unit 5 and the top plate 35 of the case body 3 are connected via a connecting bracket 7. The connecting bracket 7 is made of metal and is flat in shape. One side in the Y direction (left side in Figure 15) is a first connecting portion 71 that connects to the top plate 51c of the casing 51 of the light source unit 5, and the other side in the Y direction (right side in Figure 15) is a second connecting portion 72 that connects to the top plate 35 and reinforcing panel 35a of the case body 3. The connection structure between the first connecting portion 71 and the top plate 51c of the casing 51 of the light source unit 5 is the same as in the first embodiment described above, so its explanation is omitted here. Similarly, the connection structure between the second connecting portion 72 and the top plate 35 and reinforcing panel 35a of the case body 3 is the same as in the first embodiment described above, so its explanation is omitted here.

[0067] Because the top plate 51c of the casing 51 of the light source unit 5 and the top plate 35 of the case body 3 are connected via such a flat connecting bracket 7, there is only a gap between the top plate 51c of the casing 51 of the light source unit 5 and the top plate 35 of the case body 3 that is approximately the thickness of the connecting bracket 7. In addition, the lower end of the light source unit 5 is located close to the upper surface of the front glass plate 42.

[0068] With these configurations, even in this embodiment, the height dimension of the case body 3 can be shortened to approximately match the height dimension of the light source unit 5. Therefore, the lighting device 1 can be miniaturized.

[0069] -Replacing lighting fixtures- The lighting devices 1 according to each embodiment described above can be installed on the ceilings of newly constructed buildings such as new factories, but they can also be used as lighting devices newly installed on the ceilings of existing buildings (lighting devices that replace existing lighting devices).

[0070] The following describes the procedure for replacing an existing lighting device with the lighting device 1 according to the above embodiment (a miniaturized lighting device; hereinafter referred to as the newly installed lighting device).

[0071] The existing lighting fixture is larger than the new lighting fixture, and a relatively large recessed opening 101 is formed in the ceiling panel 100 according to the shape of the existing lighting fixture's case. Therefore, if one simply attempts to remove the existing lighting fixture from the ceiling panel 100 and install the new lighting fixture, a gap may be created between the new lighting fixture and the edge of the recessed opening 101, or the new lighting fixture may not be able to be installed at all.

[0072] In light of this, when replacing such lighting fixtures, a renewal plate is used to seal the gap.

[0073] Figure 16 is a perspective view illustrating the process of replacing an existing lighting device 1' with a new lighting device (lighting device according to the present invention; the one shown in Figure 16 is a lighting device according to the first embodiment) 1. The renewal plate 8 is made of, for example, metal and is a rectangular flat plate, with an opening (recessed opening) 81 for embedding the lighting device provided in its center. The external dimensions (width and length) of the renewal plate 8 are set to be slightly larger than the external dimensions (width and length) of the recessed opening 101 into which the existing lighting device 1' was embedded. In other words, if the model of the existing lighting device 1' is known in advance, the corresponding external dimensions of the recessed opening 101 are also known, and a renewal plate 8 of a suitable size is prepared. Furthermore, the shape of the opening 81 provided in the renewal plate 8 is set to be slightly larger than the shape (plan view shape) of the case body 3 of the new lighting device (lighting device according to the present invention) 1 and slightly smaller than the shape (plan view shape) of the front frame 41 of the new lighting device 1.

[0074] Then, in the replacement work of the lighting devices 1',1, as shown in Figure 16, after removing the existing lighting device 1' from the ceiling panel 100 (see arrow A shown by the dashed line in Figure 16), the renewal plate 8 is attached to the position in the ceiling panel 100 corresponding to the recessed opening 101 (see arrow B shown by the dashed line in Figure 16). If the strength of the ceiling panel 100 is sufficiently high, the renewal plate 8 may be bolted directly to the ceiling panel 100. Alternatively, a reinforcing bracket (a reinforcing bracket 102 similar to that shown in Figure 14(a)) may be placed on the upper surface of the opening edge of the recessed opening 101 in the ceiling panel 100, and the renewal plate 8 may be bolted across this reinforcing bracket 102 and the ceiling panel 100.

[0075] In this manner, after attaching the renewal plate 8 to the ceiling panel 100, the newly installed lighting device 1 is fitted into the opening 81 of the renewal plate 8 in the same manner as in the embodiment described above (see arrow C shown by the dashed line in Figure 16). In other words, the opening 81 provided in the renewal plate 8 is treated in the same way as the recessed opening 101 in the embodiment described above when installing the newly installed lighting device 1.

[0076] Since the lighting device (newly installed lighting device) 1 according to the present invention has a shorter height dimension compared to the existing lighting device 1', it may not be possible to support it using suspension bolts B, B, ... with support brackets 35b, 35b, ... as shown in Figure 2. In other words, when installing a new lighting device 1 as in the embodiment described above, it is possible to support the lighting device 1 by providing dedicated suspension bolts B, B, ... for the lighting device 1 (see Figure 2). However, when replacing an existing lighting device 1' with a new lighting device 1, the positions of the suspension bolts used to support the existing lighting device 1' may not match the positions of the support brackets 35b, 35b, ..., so it may not be possible to support it by inserting the suspension bolts (the suspension bolts previously used to support the existing lighting device 1') into the bolt insertion holes of the support brackets 35b, 35b, .... Therefore, in this embodiment, as shown in Figure 17 (perspective view of the newly installed lighting device 1 from above), a support frame 6 is placed across opposing support brackets 35b, 35b in the Y direction. Bolt insertion holes are provided in the support frame 6 corresponding to the positions of the suspension bolts (the suspension bolts previously used to support the existing lighting device 1'), and the newly installed lighting device 1 is supported by inserting the suspension bolts B through these bolt insertion holes. This support frame 6 is designed according to the shape of each support bracket 35b, 35b, ... and the positions of the suspension bolts previously used to support the existing lighting device 1'.

[0077] By interposing the renewal plate 8 between the ceiling panel 100 and the newly installed lighting device 1 in this way, it becomes possible to replace the existing lighting device 1' with the new lighting device 1 without creating a gap between the new lighting device 1 and the edge of the recessed opening 101.

[0078] -Other Embodiments- Furthermore, the present invention is not limited to the embodiments described above, and all modifications and applications are possible within the scope of the claims and equivalents thereof.

[0079] For example, in each of the above embodiments, the case in which the present invention is applied to a ceiling-mounted lighting device 1 was described. However, the present invention is not limited to this and can be applied to lighting devices installed in various locations.

[0080] Furthermore, in each of the above embodiments, the connecting bracket 7 that connects the top plate 51c of the casing 51 of the light source unit 5 and the top plate 35 of the case body 3 was a flat plate-shaped member with a uniform thickness throughout. The present invention is not limited to this, and may also be a flat plate-shaped member with an uneven thickness, or a plate-shaped member with a shape that is partially bent in the thickness direction. In other words, any configuration that can contribute to miniaturizing the lighting device 1 by bringing the upper end of the light source unit 5 and the top plate 35 of the case body 3 close together when the top plate 51c of the casing 51 of the light source unit 5 and the top plate 35 of the case body 3 are connected is acceptable. [Industrial applicability]

[0081] This invention is applicable to ceiling-mounted lighting devices that are designed to be explosion-proof with increased safety features. [Explanation of Symbols]

[0082] 1. Lighting device 3. Case body 35 Top plate 4 Covers 42 Front glass panel (translucent panel) 43 Spring hinge 43a Coil section 43b Locking leg 43c Cover component 47 Spring hinge locking mechanism 5 Light source units 51 Casing 51c Tabletop 54a LED board 54b LED chip 7 Connecting Brackets 8. Renewal Plate 81. Opening (Inset opening) 100 Ceiling boards 101 Recessed opening

Claims

1. In a lighting device comprising a case body that is placed in a predetermined housing space when installed, a light source unit housed inside the case body, and a light-transmitting panel that transmits light from the light source unit toward the space to be illuminated, The light source unit is configured to have an LED substrate on which multiple LED chips are mounted, The upper end of the light source unit and the top plate of the case body are in close proximity, and the lower end of the light source unit and the upper surface of the light-transmitting panel are in close proximity. The light source unit comprises a casing housing the LED substrate, the casing having a top plate extending parallel to the top plate of the case body, and the top plate of the casing and the top plate of the case body being connected by a flat connecting bracket extending parallel to the direction of extension of the top plates. The lighting device is characterized in that the connecting bracket has a first connecting portion located on the upper side of the top plate of the casing and connected to the top plate by bolts, and a second connecting portion located off the upper side of the top plate of the casing in the Y direction when the width direction of the lighting device is the X direction and the longitudinal direction is the Y direction, and connected to the top plate of the case body by bolts.

2. In the lighting device according to Claim 1, A lighting device characterized in that, of the case body, the light-transmitting panel, and the light source unit, only the light source unit has an explosion-proof structure.

3. In the lighting device according to claim 1 or 2, The cover, including the light-transmitting panel, is detachably attached to the case body by a spring hinge. The spring hinge comprises a coil portion supported by the cover and a locking leg portion continuous with the coil portion. When the cover is attached to the case body, the locking leg portion is locked to the spring hinge locking fitting provided on the case body by pressing against it. When removing the cover from the case body, pressure is applied to the locking leg portion in the opposite direction to the pressing direction to release the locking of the locking leg portion from the spring hinge locking fitting. A lighting device characterized in that a cover member made of an elastic material is attached to the tip of the locking leg portion.

4. In the lighting device according to claim 1 or 2, The lighting device is a ceiling-mounted type, The lighting device is characterized in that the case body is inserted into a recessed opening formed in a ceiling panel, and includes a renewal plate used when the shape of the existing recessed opening is larger than the shape of the case body, the outer shape of the renewal plate is larger than the shape of the existing recessed opening, and the shape of the fitting opening provided in the renewal plate is larger than the shape of the case body and smaller than the outer shape of the cover including the light-transmitting panel.

Images