Lighting fixtures

Abstract

To provide a lighting fixture capable of protecting a light source against foreign matter, which allows ventilation between the light source and the exterior.SOLUTION: A lighting fixture 1 equipped with an inner hull 30 in which a light emitting element 15a is disposed and an outer shell 11 covering a top face 31 of the inner hull 30 includes: an opening 35a for ventilation formed on the top face 31 of the inner hull 30; a plurality of enclosure walls 33 formed so as to surround the opening 35a in a multiple manner; a plurality of inner partitions 37 for connecting the enclosure walls 33 together; and a plurality of ventilation passages A divided by the plurality of inner partitions 37. Each of the plurality of enclosure walls 33 is provided with a vent hole 34 communicating with the ventilation passage A. A space inside the opening 35a and a space outside the enclosure wall 33 communicate with each other through the vent hole 34 and the ventilation passage A. The vent holes 34 are formed at a position where they do not lie on the same line when viewed from the opening 35a.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a lighting fixture.

Background Art

[0002] Conventionally, in a lighting fixture, a light source has been housed in a highly airtight housing to protect the light source from foreign matter such as water droplets. In such a lighting fixture, since ventilation cannot be performed between the inside and outside of the housing, the air inside the housing is rapidly cooled by rainfall or the like in summer, which reduces the internal pressure of the housing, leading to the problem that rainwater or splash is sucked into the housing through seams or the like of the housing. However, in recent years, lighting fixtures have been proposed that protect the light source from foreign matter such as water droplets and enable ventilation between the light source and the outside by adopting a so-called labyrinth structure as an air passage (for example, Patent Document 1). The lighting fixture in Patent Document 1 is a vehicle lamp, and the labyrinth structure is formed by an upright wall protruding rearward from the rear surface of the housing. Since foreign matter such as water droplets that have entered the labyrinth structure moves under the action of gravity, it is easy to guide the foreign matter away from the light source and allow the foreign matter to exit the labyrinth structure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, when a labyrinth structure is employed on the upper surface, for example, in a lighting fixture that illuminates vertically downward, it becomes difficult to guide foreign matter by the action of gravity. Therefore, such a lighting fixture has had the problems that foreign matter blocks the air passage without exiting the labyrinth structure, or foreign matter moves toward the light source. The present invention aims to provide a lighting fixture that can protect the light source from foreign matter and allows ventilation between the light source and the outside. [Means for solving the problem]

[0005] One embodiment of the present invention is a lighting fixture comprising an inner enclosure in which a light-emitting element is arranged inside, and an outer shell covering the upper surface of the inner enclosure, wherein the lighting fixture has a ventilation opening formed on the upper surface of the inner enclosure, a plurality of enclosure walls formed to surround the opening in multiple layers, a plurality of intermediate partition walls connecting the enclosure walls, and a plurality of ventilation passages separated by the plurality of intermediate partition walls, each of the plurality of enclosure walls having a ventilation opening that communicates with the ventilation passage, the space inside the opening and the space outside the enclosure walls communicating via the ventilation opening and the ventilation passage, and the ventilation openings are formed at positions that do not overlap in a straight line when viewed from the opening.

[0006] One embodiment of the present invention is characterized in that, in the above-mentioned lighting fixture, a breathable ventilation filter is provided in the opening.

[0007] One embodiment of the present invention is a lighting fixture in which the ventilation passage is divided by a pair of partition walls, and the plurality of ventilation openings are formed spaced apart near one of the partition walls and near the other partition wall.

[0008] One embodiment of the present invention is characterized in that, in the above-mentioned lighting fixture, a baffle plate portion is formed near the vent to obstruct the flow within the ventilation passage.

[0009] One embodiment of the present invention is a lighting fixture in which the enclosure wall surrounds the opening in at least three layers: an inner, a middle, and an outer layer, the ventilation openings of the outer and inner enclosure walls are positioned towards one side of the ventilation passage, and the ventilation openings of the middle enclosure wall are positioned towards the other side of the ventilation passage.

[0010] One embodiment of the present invention is characterized in that, in the above-mentioned lighting fixture, the upper end of the enclosure wall is in contact with the inner surface of the outer shell.

[0011] One embodiment of the present invention is characterized in that, in the above-mentioned lighting fixture, the opening is arranged on a raised mound formed on the upper surface of the inner casing.

[0012] One embodiment of the present invention is characterized in that, in the above-mentioned lighting fixture, the hill portion and the innermost enclosure wall are arranged with a gap between them.

[0013] One embodiment of the present invention is characterized in that the upper surface of the inner casing of the above-mentioned lighting fixture is flat.

[0014] One embodiment of the present invention is characterized in that the upper surface of the inner enclosure is inclined upward toward the position of the opening. [Effects of the Invention]

[0015] According to the present invention, the light source of a lighting fixture is protected from foreign matter, and ventilation is possible between the light source and the outside. [Brief explanation of the drawing]

[0016] [Figure 1] Side view of the lighting fixture according to Embodiment 1. [Figure 2] Cross-sectional view of section II-II. [Figure 3] Cross-sectional view of the light source. [Figure 4] Plan view of the upper surface of the inner enclosure. [Figure 5] Enlarged plan view of the upper surface of the inner enclosure. [Figure 6] Top view of the modified example. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a side view of the lighting fixture 1 according to the first embodiment of the present invention.

[0018] The lighting fixture 1 is a street lamp mainly used for lighting parks, plazas, sidewalks and the like, and includes a light source unit 10, a support column 50, and a holder unit 16. The light source unit 10 is a portion that emits illumination light in the lighting fixture 1, and is disposed at an upper end of the lighting fixture 1. The light source unit 10 includes an outer shell 11 and a bottom plate 13, and emits illumination light downward from an emission port 13a that is an opening formed in the bottom plate 13.

[0019] The support column 50 is a column fixed to a pole or the like extending from the ground via the holder unit 16 attached to a lower end thereof, and holds the light source unit 10 at an upper end thereof. The support column 50 is a hollow member formed of an extruded aluminum material, and supplies electric power supplied from internal wiring of a pole or the like to the light source unit 10 via power supply wiring passing through the inside of the support column 50. The holder unit 16 is a member that is fixed in a state where a lower portion thereof is inserted into a hollow pole or the like, and supports the support column 50. A support plate 16a, which is a plate-like member extending downward, is fixed to a lower end of the holder unit 16, and the support plate 16a supports a power supply device 51 and a protection device 53 respectively. The power supply device 51 converts commercial AC power supplied from internal wiring of a pole or the like into DC power, and supplies the DC power to the light source unit 10. The protection device 53 is a device including a varistor, and protects the light source unit 10 from surge current and the like.

[0020] FIG. 2 is a cross-sectional view taken along the II-II cross-section shown in FIG. 1, and shows a configuration of the light source unit 10 as viewed from below. FIG. 3 is a cross-sectional view taken along the III-III cross-section shown in FIG. 2, and shows an internal configuration of the light source unit 10.

[0021] As shown in Figure 2, in a plan view, the light source unit 10 is circular, and the support column 50 is roughly equilateral triangular in shape, with each side of the triangle curving toward the centroid. Three light outlets 13a are formed in the bottom plate 13 of the light source unit 10 along the three sides of the support column 50, and the light-emitting elements 15a are visible from each of the light-emitting elements 13a. The light-emitting elements 15a are, for example, LEDs (Light Emitting Diodes) and emit illumination light using power supplied from the power supply unit 51. In a plan view, each light-emitting element 15a is positioned inside a reflector 19. The reflector 19 is a cylindrical member with a mirrored inner surface that reflects the illumination light emitted from the light-emitting elements 15a and guides it to the light outlets 13a. The three light outlets 13a are covered by a translucent cover 17, and the illumination light passes through the cover 17 and is projected downwards. The cover 17 is a circular flat plate with an opening in the center, and the three injection ports 13a are covered by a single cover 17.

[0022] As shown in Figure 3, the light source unit 10 has an inner casing 30. The inner casing 30 is a concave member that houses a substrate 15 having a light-emitting element 15a and a reflector 19. At the lower end 38 of the inner casing 30, a flange portion 39 is formed by a recess in the side surface of the inner casing 30. The lower end 38 of the inner casing 30 is fixed to the support column 50 by bolts screwed into the flange portion 39, sandwiching the bottom plate 13. As a result, a light source chamber S2 is formed inside the inner casing 30, which is a space partitioned by the inner casing 30, the bottom plate 13, and the cover 17. The light source chamber S2 is connected to the internal space S1 of the support column 50 by a communication hole 13b, which is an opening provided in the center of the bottom plate 13, and power wiring (not shown) is drawn from the internal space S1 of the support column 50 to the light source chamber S2 via the communication hole 13b. Furthermore, as will be described in more detail later, the light source chamber S2 is configured to be able to ventilate with the ventilation space S3 through an opening 35a formed on the upper surface 31 of the inner enclosure 30.

[0023] Between each component forming the light source chamber S2, an inner circumferential packing 17a and an outer circumferential packing 17b are provided, and the joints between the components are configured to be airtight. Therefore, as shown by the dashed arrows in Figure 3, the light source chamber S2 ventilates only with the internal space S1 of the support column 50 and the ventilation space S3.

[0024] The inner circumferential packing 17a and the outer circumferential packing 17b are annular packings made of an elastic material such as rubber. The inner circumferential packing 17a is provided between the inner circumference of the cover 17 and the bottom plate 13, and is pressed against the bottom plate 13 from above by a retaining plate 14, thereby closing the joint between the cover 17 and the bottom plate 13 and gripping the inner circumference of the cover 17. The retaining plate 14 is a plate-shaped member fixed to the bottom plate 13 by fastening, and has an opening that overlaps vertically with the communication hole 13b. The outer circumferential packing 17b is provided between the outer circumference of the cover 17, the lower end 38 of the inner casing 30, and the bottom plate 13, closing the respective joints. In addition, the outer circumferential packing 17b is sandwiched between the lower end 38 of the inner casing 30 and the bottom plate 13, thereby gripping the outer circumference of the cover 17.

[0025] Furthermore, a support column packing 12 is provided between the support column 50 and the base plate 13. The support column packing 12 is a packing made of an elastic material such as rubber, and it closes the joint between the support column 50 and the base plate 13.

[0026] As shown in Figure 3, the upper surface 31 of the inner casing 30 is substantially flat, and the upper surface 31 has an enclosure wall 33 and an intermediate partition wall 37, both of which are projections that protrude upward. The outer shell 11 is fastened to the inner casing 30 such that its inner side is in contact with the upper end of the enclosure wall 33 and the upper end of the intermediate partition wall 37, and a ventilation space S3 is formed between the outer shell 11 and 30. In addition, a gap G is formed around the entire circumference between the lower end of the outer shell 11 and the outer circumference of the bottom plate 13, and the ventilation space S3 communicates with the outside of the light source unit 10 through the gap G. The gap G is located at approximately the same height as the lower end 38 of the inner casing 30 and is provided below the upper surface 31. The height dimension of the gap G is smaller than the thickness of the flange portion 39. Furthermore, the area of ​​the gap G, which is expressed by the product of the height dimension of the gap G and the length of the entire circumference of the lower end of the outer shell 11, is designed to be equal to or greater than the area of ​​the opening 35a. This eliminates the portion of the air path from the outside of the light source unit 10 to the light source chamber S2 that is smaller than the opening 35a, thereby ensuring sufficient ventilation between the light source chamber S2 and the outside. However, the specific height dimension of the gap G mentioned above is just an example, and it would be pointless to make the gap G too large and allow water to easily enter while prioritizing the above design conditions. Therefore, it is necessary to consider the above design conditions while making the dimensions of the gap G such that water cannot easily enter.

[0027] Figure 4 is a plan view of the inner enclosure 30, showing the upper surface 31 of the inner enclosure 30 as seen from above with the outer shell 11 removed. Figure 5 is an enlarged plan view of the upper surface 31. Figures 4 and 5 show arrows indicating the clockwise direction D1 and the counterclockwise direction D2, respectively, centered on the opening 35a in a plan view from above. In Figures 4 and 5, the enclosure wall 33 and the partition wall 37 are highlighted with hatching.

[0028] The top surface 31 is located in the ventilation space S3. As shown in Figure 4, a circular opening 35a is formed in the center of the top surface 31. The opening 35a is blocked from below by a ventilation filter 35b. Since the ventilation filter 35b is breathable, it prevents insects, dust, and other debris from entering the light source chamber S2, while allowing ventilation between the ventilation space S3 and the light source chamber S2. The opening 35a is also formed on a raised portion 35 of the top surface 31. The raised portion 35 is a circular, flat platform formed on the top surface 31, one level higher than the bottom of the ventilation passage A, which will be described later. An inclined portion 35c is formed on the outside of the raised portion 35, sloping downward toward the outside.

[0029] In this invention, the opening 35a and the ventilation filter 35b are provided in the light source section 10 located at the top of the lighting fixture 1. However, unlike this invention, it is also conceivable that, for example, the opening 35a be provided at the lower end of the holder section 16, and the opening 35a be designed to open to the inside of a pole or the like, and the light source chamber S2 be configured to ventilate with the inside of the pole or the like via the internal space S1 of the support column 50. In this case, rainwater or the like will not directly hit the opening 35a, and the labyrinth structure described later will not be necessary. However, in this case, since moisture from the ground is constantly supplied to the inside of the pole or the like, if the ventilation filter 35b allows moisture to pass through, there is a concern that moisture will enter the inside of the lighting fixture 1, causing malfunctions of the circuit board 15 or the like. Therefore, in this case, the ventilation filter 35b must be a filter that does not allow moisture to pass through, or the lighting fixture 1 must be equipped with a dehumidifying device. One example of a filter that prevents moisture from passing through is a dehumidifying filter using activated carbon. However, as mentioned above, in a situation where moisture is constantly supplied, the dehumidifying filter cannot release the moisture it has absorbed, so the ventilation filter 35b would need to be replaced periodically. Therefore, in the above case, the maintainability of the lighting fixture 1 deteriorates significantly, making it inconvenient to use. Furthermore, if the lighting fixture 1 is equipped with a dehumidifying device, there are problems such as the size of the lighting fixture 1 increasing and the power consumption increasing, which is not a practical configuration from the standpoint of aesthetic design and energy saving.

[0030] Taking these points into consideration, in the present invention, the opening 35a and the ventilation filter 35b are provided in the light source unit 10 located at the top of the lighting fixture 1, and a labyrinth structure, described later, is used to prevent rainwater and the like from reaching the opening 35a. With this configuration, it is possible to prevent both deterioration of the maintainability of the lighting fixture 1 due to periodic replacement of the ventilation filter 35b and failure of the circuit board 15 and the like due to moisture.

[0031] As shown in Figure 4, four enclosure walls 33 are formed in an annular shape on the upper surface 31, surrounding the central opening 35a in a quadruple fashion. Hereinafter, the four enclosure walls 33 will be defined as the first enclosure wall 33a, the second enclosure wall 33b, the third enclosure wall 33c, and the fourth enclosure wall 33d, starting from the innermost enclosure wall 33 and moving outwards. The first enclosure wall 33a is formed at a distance from the hill portion 35. Since both the hill portion 35 and the first enclosure wall 33a are formed higher than the ventilation passage A described later, a groove portion 36, which is an annular groove along the first enclosure wall 33a and the inclined portion 35c, is formed between them. As described above, the upper ends of the four enclosure walls 33 are in contact with the inside of the outer shell 11, so the four enclosure walls 33 divide the ventilation space S3 so as to separate the gap G and the opening 35a.

[0032] Furthermore, partition walls 37 are formed on the upper surface 31, extending radially from the central opening 35a and connecting the enclosure walls 33 to each other.Hereafter, the three partition walls 37 that connect the first enclosure wall 33a and the second enclosure wall 33b are defined as the first partition wall 37a.Similarly, the three partition walls 37 that connect the second enclosure wall 33b and the third enclosure wall 33c are defined as the second partition wall 37b, and the three partition walls 37 that connect the third enclosure wall 33c and the fourth enclosure wall 33d are defined as the third partition wall 37c.In this embodiment, a set of first partition walls 37a, second partition walls 37b, and third partition walls 37c are arranged on a straight line passing through the center of the opening 35a.

[0033] The first partition walls 37a, the second partition walls 37b, and the third partition walls 37c are formed at positions offset by approximately 120 degrees from each other with respect to the opening 35a. As a result, the space between the first enclosure wall 33a and the second enclosure wall 33b is divided into three equal parts by the first partition wall 37a, forming three first ventilation passages A1. Similarly, the space between the second enclosure wall 33b and the third enclosure wall 33c is divided into three equal parts by the second partition wall 37b, forming three second ventilation passages A2. In addition, the space between the third enclosure wall 33c and the fourth enclosure wall 33d is divided into three equal parts by the third partition wall 37c, forming three third ventilation passages A3. Hereafter, unless otherwise specified, the first ventilation passage A1, the second ventilation passage A2, and the third ventilation passage A3 will be collectively referred to as ventilation passage A.

[0034] Furthermore, each of the four enclosure walls 33 is provided with three ventilation openings 34, which are gaps formed at positions offset by approximately 120 degrees from the opening 35a. Of the ventilation openings 34, those provided in the first enclosure wall 33a, the second enclosure wall 33b, the third enclosure wall 33c, and the fourth enclosure wall 33d are defined as the first ventilation opening 34a, the second ventilation opening 34b, the third ventilation opening 34c, and the fourth ventilation opening 34d, respectively. The three first ventilation openings 34a are connected via a groove 36 formed between the hill portion 35 and the first enclosure wall 33a.

[0035] As shown in Figure 4, one first ventilation passage A1 and one second ventilation passage A2 are connected by one second vent 34b, and one second ventilation passage A2 and one third ventilation passage A3 are connected by one third vent 34c. Furthermore, one first ventilation passage A1 is connected to the space inside the first enclosure wall 33a by one first vent 34a, and one third ventilation passage A3 is connected to the space outside the fourth enclosure wall 33d by one fourth vent 34d. As a result, the opening 35a and the space outside the fourth enclosure wall 33d are connected to each other. At this time, the space from the first vent 34a to the fourth vent 34d that are connected to each other is defined as a ventilation labyrinth. The ventilation labyrinth is a space with a complex and intricate shape, forming a so-called labyrinth structure. In this embodiment, three ventilation mazes are formed. Each ventilation maze does not intersect with another, and each ventilation maze independently connects the space inside the first enclosure wall 33a with the space outside the fourth enclosure wall 33d. Therefore, even if one of the ventilation mazes is blocked by rainwater or debris, ventilation between the light source room S2 and the outside can be continued through the other ventilation mazes. In addition, by providing two or more ventilation mazes, rainwater that enters any of the ventilation mazes can easily escape to the outside.

[0036] Furthermore, as shown in Figure 4, a first ventilation opening 34a, which connects one first ventilation passage A1 to the space inside the first enclosure wall 33a, is formed near the first intermediate partition wall 37a that partitions the clockwise direction D1 side of the first ventilation passage A1. Specifically, the first ventilation opening 34a is positioned such that the angle between the straight line connecting the nearby first intermediate partition wall 37a and the center of the opening 35a, and the straight line connecting the center of the first ventilation opening 34a and the center of the opening 35a is 30°. Also, a second ventilation opening 34b, which connects one first ventilation passage A1 to one second ventilation passage A2, is formed near the first intermediate partition wall 37a that partitions the counterclockwise direction D2 side of the first ventilation passage A1. Specifically, the second vent 34b is positioned such that the angle between the straight line connecting the center of the nearby first partition wall 37a and the center of the opening 35a, and the straight line connecting the center of the second vent 34b and the center of the opening 35a is 20°. In this way, the two vents 34 arranged in one ventilation passage A do not overlap on a straight line when viewed from the opening 35a, and are arranged spaced apart from each other in the vicinity of the pair of partition walls 37 that divide the ventilation passage A.

[0037] Furthermore, the third ventilation opening 34c, which connects one second ventilation passage A2 and one third ventilation passage A3, is formed near the second partition wall 37b that separates the clockwise direction D1 side of the second ventilation passage A2. Specifically, the third ventilation opening 34c is positioned such that the angle between the straight line connecting the nearby second partition wall and the center of the opening 35a and the straight line connecting the center of the third ventilation opening 34c and the center of the opening 35a is 20°. In other words, the second ventilation opening 34b, which is provided in the intermediate second enclosure wall 33b among the first enclosure wall 33a, the second enclosure wall 33b, and the third enclosure wall 33c, is formed closer to the counterclockwise direction D2 side (the other side) of the first ventilation passage A1 and the second ventilation passage A2. On the other hand, the third ventilation opening 34c and the first ventilation opening 34a, which are provided in the outer third enclosure wall 33c and the inner first enclosure wall 33a, are positioned so as to be on the side (one side) of the second ventilation passage A2 and the first ventilation passage A1 in the clockwise direction D1. As a result, in one ventilation labyrinth, the space between the first ventilation opening 34a and the third ventilation opening 34c has a structure that folds back along the second enclosure wall 33b.

[0038] In addition, as shown in Figure 5, the first ventilation opening 34a, which connects one first ventilation passage A1 to the opening 35a, is formed with a small gap between it and the first partition wall 37a that partitions the clockwise direction D1 side of the first ventilation passage A1. Therefore, the first enclosure wall 33a forms a first baffle portion 32a that protrudes slightly counterclockwise in the direction D2 from each of the first partition walls 37a. Similarly, the second enclosure wall 33b forms a second baffle portion 32b that protrudes slightly clockwise in the direction D1 from each of the second partition walls 37b. Furthermore, the third enclosure wall 33c forms a third baffle portion 32c that protrudes slightly counterclockwise in the direction D2 from each of the third partition walls 37c. Hereinafter, the first obstruction plate portion 32a, the second obstruction plate portion 32b, and the third obstruction plate portion 32c will be collectively referred to as the obstruction plate portion 32.

[0039] The operation of the lighting fixture 1, which is configured as described above, will now be explained. In the part of the lighting fixture 1 that is exposed to the outside, the joints other than the gap G between the outer shell 11 of the light source unit 10 and the bottom plate 13 are sealed with gaskets to maintain airtightness. Therefore, air is ventilated between the inside of the lighting fixture 1, such as the light source chamber S2, and the outside of the lighting fixture 1 through the gap G.

[0040] Air flowing into the ventilation space S3 from gap G flows into one of the ventilation labyrinths described above through one of the three fourth ventilation openings 34d and reaches opening 35a. At opening 35a, the air flowing into opening 35a and the air in the light source chamber S2 and the internal space S1 of the support column 50 are exchanged with each other via the ventilation filter 35b. Furthermore, the air near opening 35a enters one of the ventilation labyrinths again from the first ventilation opening 34a and flows out to the outside of the outer shell 11 through the ventilation space S3 and gap G. As a result, the internal pressure of the light source chamber S2 and the internal space S1 is kept approximately equal to atmospheric pressure. Therefore, for example, even if the lighting fixture 1 is heated by direct sunlight and then cooled by sudden rain, the internal pressure of the light source chamber S2 and the internal space S1 is kept approximately equal to atmospheric pressure. Therefore, in the lighting fixture 1, it is possible to suppress the suction of external rainwater into the light source chamber S2, for example, from the joint between the outer perimeter packing 17b and the lower end portion 38 of the inner casing 30.

[0041] Through the gap G, not only air but also rainwater and other liquids can enter the ventilation space S3. In most cases, rainwater and other liquids enter the ventilation space S3 through the gap G formed near the lower end 38 of the inner enclosure 30, and then flow out of the lighting fixture 1 through the gap G again due to gravity without reaching the upper surface 31 of the inner enclosure 30. However, if the lighting fixture 1 is exposed to heavy rain accompanied by strong winds, such as during a typhoon, rainwater may reach the upper surface 31. Most of the rainwater that reaches the upper surface 31 is blocked by the fourth enclosure wall 33d, but rainwater and other liquids that enter through the gap G near the fourth vent 34d, for example, may enter the ventilation labyrinth through the fourth vent 34d.

[0042] Figure 5 shows the flow of rainwater that reaches the top surface 31 and enters one ventilation labyrinth from the fourth vent 34d, indicated by dashed arrows. The following describes the case where rainwater passes through the ventilation labyrinth from the fourth vent 34d to the first vent 34a, but the inventor's experiments have confirmed that in most cases, rainwater only penetrates to the middle of the ventilation labyrinth, such as the second ventilation passage A2. The inventor conducted an IPX5 waterproof test on the lighting fixture 1 as specified in JIS C 0920, but water only penetrated to the vicinity of the third vent 34c at most, and did not adversely affect the operation of the lighting fixture 1.

[0043] As described above, the fourth vent 34d and the third vent 34c, which are located in one third ventilation passage A3, do not overlap in a straight line when viewed from the opening 35a. Therefore, rainwater that enters the ventilation labyrinth collides with the third enclosure wall 33c and is bent approximately perpendicular to its direction of travel in either a clockwise direction D1 or a counterclockwise direction D2, and then flows through the third ventilation passage A3. At this time, the force of the rainwater is attenuated.

[0044] Rainwater flowing through the third ventilation passage A3 flows into the second ventilation passage A2 via the third vent 34c. The third vent 34c is formed between it and the third partition wall 37c via a third baffle plate 32c. Therefore, rainwater flowing clockwise D1 through the third ventilation passage A3 cannot directly pass through the third vent 34c along the third partition wall 37c after reaching it. Unlike this embodiment, if the third baffle plate 32c were absent, the rainwater would easily pass through the third vent 34c along the third partition wall 37c, and thus would flow into the second ventilation passage A2 with momentum. In other words, in this embodiment, within the third ventilation passage A3, the flow of rainwater toward the third vent 34c is obstructed by the third baffle plate 32c. Subsequently, the rainwater flows mainly along the third baffle plate section 32c in a counterclockwise direction D2, and then passes through the third vent opening 34c. At this point, the rainwater is deflected in the opposite direction of its flow, its momentum is greatly reduced, and it flows into the second ventilation passage A2.

[0045] Rainwater flowing into the second ventilation passage A2 collides with the second enclosure wall 33b, where it is deflected almost perpendicularly to its direction of travel, reducing its momentum, and it flows counterclockwise in the second ventilation passage A2. Rainwater flowing counterclockwise in the second ventilation passage A2 in the direction of travel D2 is deflected clockwise in the direction of travel D1 mainly along the second intermediate partition wall 37b and the second baffle plate section 32b, further reducing its momentum. After that, the rainwater passes through the second vent 34b and flows into the first ventilation passage A1.

[0046] As described above, the second vents 34b and third vents 34c that open into each of the second ventilation passages A2 are located near the second partition wall 37b that separates the counterclockwise and clockwise sides of the second ventilation passage A2, respectively. Therefore, rainwater flows through the second ventilation passage A2 over almost its entire length, and the force of the rainwater is attenuated by friction.

[0047] Rainwater flowing into the first ventilation passage A1 collides with the first enclosure wall 33a, where it is deflected almost perpendicularly to its direction of travel, reducing its momentum, and it flows clockwise in direction D1 through the first ventilation passage A1. As the rainwater flows along almost the entire length of the first ventilation passage A1, its momentum is reduced by friction, and it flows to the first intermediate partition wall 37a. Upon reaching the first intermediate partition wall 37a, the rainwater is deflected counterclockwise in direction D2 along the first intermediate partition wall 37a and the first baffle plate section 32a, further reducing its momentum. After that, the rainwater passes through the first ventilation opening 34a.

[0048] As described above, rainwater flows counterclockwise in the direction D2 along almost the entire length of the second ventilation channel A2, and then flows clockwise in the direction D1 along almost the entire length of the first ventilation channel A1. Therefore, the rainwater flows in a U-turn through the ventilation labyrinth, effectively attenuating the force of the rainwater.

[0049] Rainwater that has passed through the first vent 34a flows down the inclined section 35c toward the opening 35a. The opening 35a is formed on a hill 35 which is one level higher than the bottom of the first ventilation passage A1, and the inclined section 35c has an upward slope toward the hill 35. As described above, the force of the rainwater is attenuated as it passes through the ventilation labyrinth, so the rainwater does not rise up the inclined section 35c to the hill 35, but flows down along the inclined section 35c.

[0050] Rainwater flowing down from the inclined section 35c flows into the groove section 36. The rainwater that flows down from the inclined section 35c loses momentum and accumulates in the groove section 36. Also, for example, if a large amount of rainwater flows in from one first vent 34a, the rainwater accumulated in the groove section 36 is pushed out by the subsequent rainwater and flows into the first vents 34a of two different ventilation mazes, which are different from the ventilation maze that was the entry path for the rainwater. In this way, even if a large amount of rainwater flows from the ventilation maze into the inside of the first enclosure wall 33a, the rainwater escapes through the groove section 36 to a ventilation maze different from the entry path and is then drained outside the ventilation maze.

[0051] As described above, this embodiment provides the following effects.

[0052] A lighting fixture 1 comprises an inner enclosure 30 in which a light-emitting element 15a is arranged inside, and an outer shell 11 covering the upper surface 31 of the inner enclosure 30. The lighting fixture 1 has a ventilation opening 35a formed on the upper surface 31 of the inner enclosure 30, a plurality of enclosure walls 33 formed to surround the opening 35a in multiple layers, a plurality of intermediate partition walls 37 connecting the enclosure walls, and a plurality of ventilation passages A separated by the plurality of intermediate partition walls 37. Each of the plurality of enclosure walls 33 has a ventilation opening 34 that communicates with the ventilation passages A. The space inside the opening 35a and the space outside the enclosure walls 33 are connected via the ventilation openings 34 and the ventilation passages A, and the ventilation openings 34 are formed at positions that do not overlap in a straight line when viewed from the opening 35a. As a result, the interior of the inner casing 30 of the lighting fixture 1 can be ventilated between the space outside the enclosure wall 33 via the ventilation opening 34 and the ventilation passage A. Therefore, the internal pressure of the inner casing 30 becomes approximately equal to atmospheric pressure, and even if the air inside the inner casing 30 is rapidly cooled, for example, the inner casing 30 will be less likely to absorb water. Furthermore, since the ventilation opening 34 is formed in a position that does not overlap with the opening 35a in a straight line, rainwater entering from the space outside the enclosure wall 33 passes through the ventilation opening 34 while curving along the ventilation path A. As a result, the force of foreign matter such as rainwater is attenuated, making it difficult for foreign matter to reach the opening 35a. Consequently, the light-emitting element 15a is protected from foreign matter.

[0053] Furthermore, according to this embodiment, a breathable ventilation filter 35b is provided in the opening 35a. This prevents insects, dust, and other debris from entering the inner enclosure 30 through the ventilation opening 34. Therefore, the light-emitting element 15a is protected from foreign matter.

[0054] Furthermore, according to this embodiment, the ventilation passage A is divided by a pair of partition walls 37, and the multiple ventilation openings 34 are formed spaced apart near the partition wall 37 on the counterclockwise direction D2 side and near the partition wall on the clockwise direction D1 side. As a result, foreign matter such as rainwater flows along almost the entire length of the ventilation channel A, increasing the path for the foreign matter to reach the opening 35a. Therefore, it becomes more difficult for foreign matter to reach the opening 35a, and the light-emitting element 15a is protected from foreign matter.

[0055] Furthermore, according to this embodiment, a baffle plate portion 32 that obstructs the flow within the ventilation passage A is formed near the ventilation opening 34. As a result, foreign matter such as rainwater flowing through the ventilation passage A is less likely to enter the ventilation opening 34. Therefore, foreign matter is less likely to reach the opening 35a, and the light-emitting element 15a is protected from foreign matter.

[0056] Furthermore, according to this embodiment, the enclosure wall 33 surrounds the opening 35a in at least three layers: inner, middle, and outer. The third outer enclosure wall 33c and the third ventilation opening 34c and first ventilation opening 34a of the inner first enclosure wall 33a are positioned towards the side of the second ventilation passage A2 and the first ventilation passage A1 in the counterclockwise direction D2, while the second ventilation opening 34b of the middle second enclosure wall 33b is positioned towards the side of the first ventilation passage A1 and the second ventilation passage A2 in the clockwise direction D1. As a result, foreign matter such as rainwater flows through the second ventilation passage A2 in a clockwise direction D1, and then flows through the first ventilation passage A1 in a counterclockwise direction D2. Therefore, the foreign matter flows in a U-turn manner, its momentum is reduced, and it becomes difficult for it to reach the opening 35a. Thus, the light-emitting element 15a is protected from foreign matter.

[0057] Furthermore, according to this embodiment, the upper end of the enclosure wall 33 contacts the inner surface of the outer shell 11. As a result, the heat generated by the light-emitting element 15a located inside the inner enclosure 30 is directly conducted from the enclosure wall 33 to the outer shell 11. Therefore, the light-emitting element 15a can be protected from foreign matter such as rainwater, and the heat dissipation performance of the lighting fixture 1 is improved.

[0058] The opening 35a is positioned on a mound 35 formed on the upper surface 31 of the inner enclosure 30, which is higher than the bottom of the ventilation passage A. As a result, even if foreign matter such as rainwater reaches the inside of the enclosure wall 33, any foreign matter that cannot climb from the ventilation passage A to the hill portion 35 will not reach the opening 35a. Therefore, it becomes difficult for foreign matter to reach the opening 35a, and the light-emitting element 15a is protected from foreign matter.

[0059] The hill portion 35 and the innermost first enclosure wall 33a are spaced apart. As a result, a groove 36 is formed between the hill portion 35 and the first enclosure wall 33a, which is recessed to a position lower than the hill portion 35 and the first enclosure wall 33a. Therefore, even if a large amount of foreign matter such as rainwater flows into the inside of the first enclosure wall 33a from one ventilation opening 34, the foreign matter can escape through another ventilation opening 34 via the groove. Consequently, it becomes difficult for foreign matter to reach the opening 35a, and the light-emitting element 15a is protected from foreign matter.

[0060] Furthermore, according to this embodiment, the upper surface 31 of the inner enclosure 30 is flat. This makes it easier to form the inner casing 30 and simplifies the configuration of the lighting fixture 1. Furthermore, the appearance of lighting fixture 1 can be made simple.

[0061] (modified version) It should be noted that the first embodiment described above is merely one aspect of the present invention, and can be arbitrarily modified and applied without departing from the spirit of the present invention.

[0062] In the first embodiment, an inner enclosure 30 with a substantially flat upper surface 31 was described as an example of the inner enclosure 30, but the upper surface 31 does not have to be substantially flat. For example, the upper surface 31 of the inner enclosure 30 may be configured to slope upward toward the position of the opening 35a. As a result, foreign matter such as rainwater will have its force attenuated by the upward slope of the upper surface 31 before it reaches the opening 35a. Therefore, it becomes more difficult for rainwater to reach the opening 35a, and the light-emitting element 15a is protected from foreign matter.

[0063] In the first embodiment, the first vent 34a was described as being located near the first partition wall 37a that partitions the clockwise direction D1 side of the first ventilation passage A1. The second vent 34b was described as being located near the first partition wall 37a that partitions the counterclockwise direction D2 side of the first ventilation passage A1. Furthermore, the third vent 34c was described as being located near the second partition wall 37b that partitions the clockwise direction D1 side of the second ventilation passage A2. In the first embodiment, the positional relationship when the vent 34 is located near the partition wall 37 was described using the angle between the straight line connecting the center of the partition wall 37 and the center of the opening 35a, and the straight line connecting the center of the vent 34 and the center of the opening 35a, but this is only one example. For the ventilation opening 34 to be located "near" the partition wall 37, the width of the ventilation opening 34 and the amount of protrusion of the baffle plate portion 32 should be set based on the width of the ventilation passage A, as described below.

[0064] The width of the vent opening 34 is set to be approximately the same as the width of the standard ventilation passage A. If the width of the vent opening 34 is smaller than the width of ventilation passage A, water that enters the ventilation labyrinth will have difficulty reaching the opening 35a, but the water that enters the ventilation labyrinth will have difficulty draining, and the ventilation labyrinth will be more likely to become blocked. Conversely, if the width of the vent opening 34 is larger than the width of ventilation passage A, water that enters the ventilation labyrinth will drain easily, but it will also be more likely to reach the opening 35a. In addition, the amount of protrusion of the baffle plate portion 32 is set to be equal to or less than the width of the standard ventilation passage A. As a result, rainwater that enters the ventilation labyrinth flows along almost the entire length of the ventilation passage A, so the force of the rainwater is efficiently attenuated. Even if the amount of protrusion of the baffle plate portion 32 is equal to or less than the width of the ventilation passage A, the baffle plate portion 32 can obstruct the flow of rainwater in the ventilation passage A, and it is possible to suppress rainwater from flowing directly into the ventilation opening 34 along the partition wall 37. For example, in the first embodiment, the amount of protrusion of the baffle plate portion 32 is about half the width of the ventilation passage A. In this way, by making the width of the vent 34 approximately the same as the width of the ventilation passage A, and by making the protrusion amount of the baffle plate portion 32 equal to or less than the width of the ventilation passage A, the vent 34 is positioned "near" the partition wall 37.

[0065] The width of the ventilation passage A, which serves as the basis for the width of the ventilation opening 34 and the protrusion amount of the baffle plate portion 32 as described above, is determined from the area of ​​the gap G and the area of ​​the opening 35a. The width of the ventilation passage A is set such that the product of the number of ventilation labyrinths and the cross-sectional area of ​​one ventilation passage A is greater than the area of ​​the gap G, and the cross-sectional area of ​​one ventilation passage A is greater than the area of ​​the opening 35a. As a result, if the ventilation labyrinth is not blocked by foreign matter, the portion of the airflow path between the gap G and the opening 35a with a cross-sectional area smaller than the opening 35a can be removed, thereby ensuring sufficient ventilation between the light source chamber S2 and the ventilation space S3. Furthermore, even if all but one of the ventilation labyrinths are blocked by rainwater, the cross-sectional area of ​​the airflow path will be larger than the area of ​​the opening 35a, allowing sufficient air to flow in from the unblocked ventilation labyrinth. This makes it less likely for the drainage of rainwater from the blocked ventilation labyrinth to be obstructed.

[0066] Furthermore, while the configurations shown in Figures 4 and 5 illustrate an example of the enclosure wall 33, ventilation opening 34, partition wall 37, and ventilation passage A formed on the upper surface 31, the configuration of the upper surface 31 is not limited to these. Examples of modified configurations of the upper surface 31 are given below.

[0067] Figure 6 is a schematic diagram of the top surface 31 in a modified example, showing the top surface 31 in a plan view. Figure 6(A) shows the configuration of the enclosure wall 33, vents 34, partition wall 37, and ventilation passage A shown in Figure 4, from the first vent 34a to the third vent 34c, in order to show the correspondence between the plan view and the schematic diagram of the top surface 31. For the sake of explanation, the enclosure wall 33 is shown as being formed in three layers in Figure 6, but the enclosure wall 33 only needs to be formed in two or more layers.

[0068] As shown in Figure 6(B), the number of ventilation mazes formed on the upper surface 31 may be more than three. For example, Figure 6(B) has four ventilation mazes. However, if there are not two or more ventilation mazes, rainwater that enters the ventilation mazes will have difficulty escaping to the outside, so it is desirable to provide two or more ventilation mazes. Also, as the number of ventilation mazes formed increases, the length of the path per ventilation maze decreases, so it is desirable that the number of ventilation mazes formed be between two and four.

[0069] Furthermore, as shown in Figure 6(C), the first intermediate partition wall 37a and the second intermediate partition wall 37b may be configured not to overlap on a straight line. In addition, as shown in Figure 6(D), in the ventilation maze, the first vent 34a may be provided on the clockwise direction D1 side of the first ventilation passage A1, and the second vent 34b and third vent 34c may be provided on the counterclockwise direction D2 side of the first ventilation passage A1 and the second ventilation passage A2, respectively. In the configuration shown in Figure 6(D), rainwater flows in the clockwise direction D1 in both the first ventilation passage A1 and the second ventilation passage A2, so the rainwater does not make a U-turn in the ventilation maze. Even in this configuration, the force of the rainwater that enters the ventilation maze is sufficiently attenuated by the baffle plate portion 32 before flowing into the first vent 34a and does not reach the opening 35a formed in the hill portion 35.

[0070] Furthermore, as shown in Figures 6(E) and (F), a single ventilation labyrinth may be configured to include multiple first ventilation passages A1 and multiple second ventilation passages A2. In this case, the ventilation labyrinth is bent in a zigzag pattern, and the force of rainwater is attenuated as it flows alternately through the first ventilation passages A1 and the second ventilation passages A2. In these two modified examples, the structure does not have such that the first ventilation opening 34a, the second ventilation opening 34b, and the third ventilation opening 34c all overlap in a straight line when viewed from the opening 35a. Note that in these two modified examples, the force of rainwater is attenuated efficiently, but it is difficult for rainwater that has entered the ventilation labyrinth to escape to the outside.

[0071] Furthermore, the top surface 31, the enclosure wall 33, the hill portion 35, and the opening 35a may have shapes other than circular. For example, as shown in Figure 6(G), the top surface 31, the enclosure wall 33, the hill portion 35, and the opening 35a may be approximately square in plan view. Also, the shapes of the top surface 31, the enclosure wall 33, the hill portion 35, and the opening 35a are not limited to circular or square, but may be any shape such as a triangle, ellipse, or other polygon. Furthermore, the enclosure wall 33, hill portion 35, and opening 35a, which are approximately square as shown in Figure 6(G), may be formed on a circular top surface 31, and the shapes of each element can be combined arbitrarily. [Explanation of Symbols]

[0072] 1 Lighting fixtures 11 Outer shell 15a Light-emitting element 30 Inner Enclosure 31 Top surface 32 Obstacle board section 33 Enclosure wall 34 Ventilation holes 35 Hill 35a opening 35b Ventilation filter 36 Groove 37 Partition wall 38 Lower end A ventilation channel

Claims

1. In a lighting fixture comprising an inner enclosure in which a light-emitting element is arranged inside, and an outer shell covering the upper surface of the inner enclosure, It has a ventilation opening formed on the upper surface of the inner enclosure, a plurality of enclosure walls formed to surround the opening in multiple layers, a plurality of intermediate partition walls connecting the enclosure walls, and a plurality of ventilation passages separated by the plurality of intermediate partition walls. Each of the aforementioned enclosure walls has a ventilation opening that communicates with the ventilation passage. The system comprises a plurality of independent ventilation labyrinths that connect the space inside the innermost enclosure wall and the space outside the outermost enclosure wall, which are formed by the aforementioned ventilation passages and ventilation openings. The multiple vents constituting one of the aforementioned ventilation labyrinths are formed in positions that do not overlap in a straight line when viewed from the opening. A lighting fixture characterized by the following features.

2. The lighting fixture according to claim 1, characterized in that a breathable ventilation filter is provided in the opening.

3. In a lighting fixture comprising an inner enclosure in which a light-emitting element is arranged inside, and an outer shell covering the upper surface of the inner enclosure, It has a ventilation opening formed on the upper surface of the inner enclosure, a plurality of enclosure walls formed to surround the opening in multiple layers, a plurality of intermediate partition walls connecting the enclosure walls, and a plurality of ventilation passages separated by the plurality of intermediate partition walls. Each of the multiple enclosure walls has a ventilation opening that communicates with the ventilation passage, and the space inside the opening and the space outside the enclosure wall are connected via the ventilation opening and the ventilation passage, and the ventilation openings are formed in positions that do not overlap in a straight line when viewed from the opening, The lighting fixture is characterized in that the ventilation passage is divided by a pair of partition walls, and the multiple ventilation openings are formed spaced apart near one of the partition walls and near the other partition wall.

4. The lighting fixture according to claim 3, characterized in that a baffle plate portion is formed near the vent to obstruct the flow within the ventilation passage.

5. The lighting fixture according to claim 1, characterized in that the enclosure wall surrounds the opening in at least three layers: inner, middle, and outer, and the vents of the outer and inner enclosure walls are positioned towards one side of the ventilation passage, and the vents of the middle enclosure wall are positioned towards the other side of the ventilation passage.

6. The lighting fixture according to claim 1, characterized in that the upper end of the enclosure wall is in contact with the inner surface of the outer shell.

7. The lighting fixture according to claim 1, characterized in that the opening is positioned on a mound formed on the upper surface of the inner casing, which is one level higher than the bottom of the ventilation passage.

8. The lighting fixture according to claim 7, characterized in that the hill portion and the innermost enclosure wall are arranged with a gap between them.

9. The lighting fixture according to any one of claims 1 to 8, characterized in that the upper surface of the inner enclosure is flat.

10. The lighting fixture according to any one of claims 1 to 8, characterized in that the upper surface of the inner enclosure is inclined upward toward the position of the opening.

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