CN111051765B

CN111051765B - Ceiling embedded type lighting device

Info

Publication number: CN111051765B
Application number: CN201780094494.6A
Authority: CN
Inventors: 伏江辽; 松原大介; 吉野勇人
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2017-09-07
Filing date: 2017-09-07
Publication date: 2022-02-25
Anticipated expiration: 2037-09-07
Also published as: WO2019049262A1; JP6801793B2; CN111051765A; JPWO2019049262A1

Abstract

A ceiling embedded lighting device (1A) is provided with: a light source (2); a heat sink (3) having a plurality of heat radiating fins (3a) for radiating heat generated by the light source (2); a housing (4) having a first air vent (4a) and at least partially covering the heat sink (3); and a cooling fan (5) that generates an air flow for cooling the heat sink (3). The volume of the space occupied by the cooling fan (5) is smaller than the volume of the space occupied by the radiator (3). The inner space of the housing (4) is in fluid communication with the space (200) below the ceiling (100) via a first vent (4 a). The space (300) on the back of the ceiling is a space above the top plate (100) and outside the housing (4), and the cooling fan (5) sucks air from the space (200) below the top plate (100) into the space inside the housing (4) through the first air vent (4a), and discharges the sucked air into the space (300) on the back of the ceiling.

Description

Ceiling embedded type lighting device

Technical Field

The invention relates to a ceiling embedded type lighting device.

Background

Lighting devices using light sources such as Light Emitting Diodes (LEDs) are widely used. If the temperature of the light source increases due to heat generation of the light source, energy efficiency decreases or the life of the light source becomes short. Therefore, in order to avoid an increase in the temperature of the light source, it is desirable to improve the heat dissipation property of the heat emitted from the light source.

Patent document 1 listed below discloses an invention in which, in an embedded ceiling lighting device including LEDs, heat radiating fins for radiating heat of the LEDs, ducts connected to air-cooling passages formed between the heat radiating fins, and a fan for generating an air flow in the ducts are provided.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-114806

Disclosure of Invention

Problems to be solved by the invention

In the invention of patent document 1, air on the back surface of the ceiling is supplied to the heat sink by a fan. The space behind the ceiling tends to have a higher temperature than the room. This is because a space on the back of the ceiling is provided with a device that generates heat, such as a lighting device, and the space on the back of the ceiling is narrow, so that heat is easily accumulated. In the invention of patent document 1, since the air on the ceiling back surface having such a high temperature is supplied to the heat radiating fins, it is difficult to radiate heat from the heat radiating fins, and there is a possibility that it is difficult to sufficiently cool the light source.

The present invention has been made to solve the above-described problems, and an object thereof is to provide a ceiling-embedded lighting device capable of improving the performance of a cooling light source.

Means for solving the problems

The ceiling embedded type lighting device of the invention comprises: a light source; a heat sink having a plurality of heat radiating fins for radiating heat generated by the light source; a housing having a first vent and at least partially covering the heat sink; and a cooling fan that generates an air flow for cooling the radiator, wherein a volume of a space occupied by the cooling fan is smaller than a volume of a space occupied by the radiator, an internal space of the casing is in fluid communication with a space below the ceiling through the first air vent, the space on the back of the ceiling is a space above the ceiling and outside the casing, and the cooling fan sucks air from the space below the ceiling into the internal space of the casing through the first air vent and discharges the sucked air to the space on the back of the ceiling.

Effects of the invention

According to the present invention, the performance of cooling the light source can be improved by sucking air into the internal space of the housing through the first air vent from the space below the ceiling by the cooling fan and discharging the sucked air into the space behind the ceiling.

Drawings

Fig. 1 is a perspective view of the ceiling-embedded lighting device according to embodiment 1, as viewed obliquely from below.

Fig. 2 is a sectional perspective view of the ceiling embedded lighting device of embodiment 1 as viewed from obliquely above.

Fig. 3 is a cross-sectional side view of the ceiling embedded lighting device of embodiment 1.

Fig. 4 is a sectional perspective view of the ceiling embedded lighting device of embodiment 2 as viewed from obliquely above.

Fig. 5 is a sectional perspective view of the ceiling embedded lighting device of embodiment 3 as viewed from obliquely above.

Fig. 6 is a perspective view of the ceiling-embedded lighting device according to embodiment 4, as viewed obliquely from below.

Fig. 7 is a cross-sectional side view of the ceiling embedded lighting device of embodiment 4.

Fig. 8 is a sectional perspective view of the ceiling embedded lighting device of embodiment 5 as viewed from obliquely above.

Fig. 9 is a sectional perspective view of the ceiling embedded lighting device of embodiment 6 as viewed from obliquely above.

Fig. 10 is a plan view of the ceiling embedded lighting device according to embodiment 7.

Fig. 11 is a perspective view of the ceiling-embedded lighting device according to embodiment 8, as viewed obliquely from below.

Fig. 12 is a sectional perspective view of the ceiling embedded lighting device of embodiment 8, as viewed from obliquely above.

Fig. 13 is a functional block diagram of the ceiling-embedded lighting device according to embodiment 9.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings. The same reference numerals are given to the common or corresponding elements in the drawings, and redundant description is simplified or omitted. The present disclosure can include all combinations of combinable configurations among the configurations described in the embodiments below.

Embodiment mode 1

Fig. 1 is a perspective view of a ceiling-embedded lighting device 1A according to embodiment 1, as viewed obliquely from below. Fig. 2 is a sectional perspective view of the ceiling embedded lighting device 1A of embodiment 1 as viewed from obliquely above. Fig. 3 is a cross-sectional side view of the ceiling-embedded lighting device 1A of embodiment 1. Fig. 2 and 3 correspond to cross-sectional views taken along a plane including the center line of the ceiling embedded lighting device 1A.

The ceiling embedded type lighting device 1A shown in these figures is installed to be embedded in a ceiling, and illuminates an indoor space below the ceiling by emitting light downward. The ceiling embedded lighting device 1A can be installed on a ceiling of a commercial facility, a business office, a house, or the like, for example, and used. In the following description, the up and down directions are determined based on the posture when the ceiling-embedded illumination device 1A is used. Fig. 2 and 3 show a state in which the ceiling-embedded illumination device 1A is installed on the ceiling board 100. The top panel 100 forms a ceiling of a room. Fig. 1 shows a state in which a ceiling embedded lighting device 1A is installed in front of a ceiling.

The ceiling-embedded lighting device 1A includes a light source 2, a heat sink 3, a housing 4, and a cooling fan 5. The light source 2 emits light downward from the ceiling embedded illumination device 1A. The light source 2 in the present embodiment includes a Chip On Board (COB) type LED package. According to the present embodiment, the light source 2 includes a COB type LED package, and the following effects can be obtained. Since the mounting area of the LEDs can be reduced, the ceiling-embedded illumination device 1A can be reduced in size and weight as a whole. For example, the light source 2 may include a COB type LED package that emits white light, in which a plurality of bare blue LED chips are arranged and sealed with a resin material in which a yellow phosphor is mixed.

As a modification, the light source 2 may include a light emitting element other than a COB type LED package. For example, the light source 2 may include at least one of a surface mount type LED package, a shell type LED package, an LED package with a light distribution lens, and an LED packaged in a chip size. By dispersing and arranging a plurality of LED packages necessary for obtaining a desired light flux, it is possible to obtain a lighting device with higher efficiency by suppressing an increase in the temperature of the light source. The light source 2 is not limited to the LED, and may include an organic Electroluminescence (EL) element, a semiconductor laser, or the like.

The heat sink 3 cools the light source 2 by dissipating heat generated by the light source 2. As shown in fig. 2, the heat sink 3 includes a plurality of fins 3a and a base 3b that supports the root portions of the fins 3 a. The base 3b has a substantially plate-like shape as a whole. The base 3b has an upper surface and a lower surface. When the ceiling embedded type lighting device 1A is used, the upper surface and the lower surface of the base 3b are substantially horizontal. As shown in fig. 2 and 3, the light source 2 is disposed below the base 3 b. The light source 2 is disposed so as to be thermally conductive with respect to the lower surface of the base 3 b. Heat generated by the light source 2 is conducted toward the base 3 b. The light source 2 may be in contact with the lower surface of the base 3b via a heat conductive material. The upper surface of a light source substrate (not shown) having the light source 2 mounted on the lower surface thereof may be in contact with the lower surface of the base 3b directly or via a thermally conductive material. The thermally conductive material may be any of thermally conductive grease, a thermally conductive sheet, a thermally conductive adhesive, and a thermally conductive double-sided adhesive tape, for example. The light source substrate on which the light source 2 is mounted and the base 3b may be integrally formed.

A plurality of fins 3a are arranged above the base 3 b. The heat radiation fins 3a protrude upward from the upper surface of the base 3 b. The heat radiation fins 3a are perpendicular with respect to the upper surface of the base 3 b. The heat radiation fins 3a in the present embodiment have a plate-like shape. The plurality of fins 3a are arranged in parallel with each other. Heat generated by the light source 2 is conducted to the base 3b, and further conducted from the base 3b to the heat sink 3 a. Heat is radiated from the surfaces of the base 3b and the heat sink 3a into the air. By increasing the surface area with the base 3b and the heat sink 3a, the heat generated by the light source 2 can be efficiently dissipated. As a result, the temperature of the light source 2 can be reduced, and thus the energy efficiency, i.e., the light emission efficiency, of the light source 2 can be improved, and the lifetime of the light source 2 can be extended. As a modification, a heat pipe that moves the heat of the light source 2 to the heat sink 3a may be provided.

The heat sink 3 is preferably made of a metal material that is light in weight and high in thermal conductivity. Examples of such a metal material include aluminum, aluminum-based alloys, copper-based alloys, and stainless steel. The heat radiation fins 3a of the present embodiment are made of sheet metal. This can reduce the weight. The method of fixing the fin 3a to the base 3b may be any method such as caulking, screwing, bonding, welding, or brazing. The base 3b and the heat sink 3a may be integrally formed by, for example, die casting.

The housing 4 at least partially covers the heat sink 3. The case 4 is provided to be embedded in a hole formed in the top plate 100. The housing 4 has a first vent 4a and a second vent 4 b. The cooling fan 5 generates an air flow that cools the radiator 3. The cooling fan 5 discharges air sucked from below upward. In the present embodiment, the cooling fan 5 is disposed inside the second air vent 4 b.

In the present embodiment, the cooling fan 5 is an axial fan including a propeller fan and a motor for rotating the propeller fan. The center line of the cooling fan 5 is perpendicular to the top plate 100. The rotation axis of the propeller fan of the cooling fan 5 is perpendicular to the top plate 100. As a modification, instead of the axial flow fan as in the present embodiment, a centrifugal fan, a diagonal flow fan, a cross flow fan, or the like may be used as the cooling fan 5. The cooling fan 5 may be any fan as long as it is a fan of a forced air cooling system.

The inner space of the housing 4 is in fluid communication with the indoor space 200, which is a space below the ceiling (top plate 100), via the first vent 4 a. The space 300 behind the ceiling is a space above the ceiling (top plate 100) and outside the housing 4. The internal space of the housing 4 is in fluid communication with the space 300 behind the ceiling via the second vent 4 b.

The dotted line with arrows in fig. 3 indicates a part of the flow of air when the cooling fan 5 is operating. When the cooling fan 5 is operated, the following is performed. Air is sucked into the internal space of the casing 4 through the first air vent 4a from the indoor space 200 below the top plate 100. The sucked air is discharged to the space 300 behind the ceiling through the second air vents 4 b. The air flowing from the first air vent 4a to the second air vent 4b flows along the surfaces of the heat sink 3a and the base 3b, and the heat sink 3 is cooled. This enables the heat of the light source 2 to be dissipated more efficiently, and the temperature of the light source 2 to be further reduced.

The temperature of the space 300 behind the ceiling is likely to be higher than the temperature of the indoor space 200. That is, the air in the indoor space 200 is often cooler than the air in the space 300 behind the ceiling. According to the present embodiment, the radiator 3 can be cooled by the low-temperature air taken in from the indoor space 200. Therefore, a good cooling performance can be obtained, which is advantageous in reducing the temperature of the light source 2. As a result, the light source 2 can be made more efficient, longer in life, and more highly luminous.

The air heated by the heat of the radiator 3 is discharged to the space 300 behind the ceiling. Therefore, the heated air can be reliably prevented from flowing into the housing 4 again from the first air vent 4 a. Since the heated air can be prevented from being mixed with the air in the indoor space 200, the temperature of the air sucked through the first air vent 4a can be maintained low.

Since the heat sink 3 can be cooled by the forced convection of the cooling fan 5, the heat sink 3 can be made smaller and lighter than a case without the natural convection of the cooling fan 5. In particular, since the cooling is performed by the low-temperature air from the indoor space 200, the size of the radiator 3 can be further reduced. This also enables the ceiling-embedded illumination device 1A to be reduced in size as a whole, and thus can be easily installed even when the ceiling back space 300 is narrow.

In the present embodiment, a space 11 is formed between the first vent 4a and the base 3 b. A part of the lower surface of the base 3b is exposed to the space 11. A part of the airflow flowing in from the first air vent 4a flows along the lower surface of the base 3b in the space 11. This can promote heat dissipation from the lower surface of the base 3b, and thus can further improve cooling performance.

In the present embodiment, the volume of the space occupied by the cooling fan 5 is smaller than the volume of the space occupied by the heat sink 3. The "volume of the space occupied by the cooling fan 5" corresponds to, for example, the volume of one mass body surrounded by a smooth surface along the contour of the cooling fan 5. The "space occupied by the heat sink 3" corresponds to, for example, the volume of one mass body surrounded by a smooth surface along the contour of the heat sink 3.

According to the present embodiment, the volume of the space occupied by the cooling fan 5 is smaller than the volume of the space occupied by the heat sink 3, and the following effects can be obtained. Since the cooling fan 5 is relatively small in size, the size of the entire ceiling-embedded illumination device 1A can be reduced, and the ceiling-embedded illumination device can be easily installed even when the ceiling back space 300 is narrow. Since the radiator 3 can be cooled by relatively cool air taken in from the indoor space 200, a sufficiently good cooling performance can be obtained even if the cooling fan 5 having a relatively small size is used.

In the present embodiment, the case 4 covers the entire heat sink 3. The radiator 3 and the space 300 behind the ceiling are all partitioned by the casing 4 except for the second air vent 4 b. Since the air flow is blown out from the second air vent 4b to the space 300 behind the ceiling, the warm air in the space 300 behind the ceiling does not flow into the inside of the casing 4. With such a configuration, warm air in the space 300 behind the ceiling can be reliably prevented from contacting the radiator 3, and therefore the radiator 3 can be cooled more efficiently.

In the present embodiment, the cooling fan 5 is disposed on the downstream side of the radiator 3 in the path of the air flow, but as a modification, the cooling fan 5 may be disposed on the upstream side of the radiator 3. For example, the cooling fan 5 may be disposed in the flow path between the first air vent 4a and the heat sink 3.

As shown in fig. 2, the ceiling-embedded illumination device 1A further includes a reflector 6. The reflector 6 forms a reflecting surface around the light source 2. The reflecting surface is formed in a conical surface shape around the light emitting surface of the light source 2. The reflecting surface of the reflector 6 reflects light emitted laterally from the light source 2 downward. This can increase the amount of light emitted downward from the ceiling-embedded illumination device 1A. At least the reflecting surface of the reflector 6 is preferably made of a white material or a white-coated material having a high reflectance and a low absorptance. The reflector 6 may be fixed to the housing 4 or may be fixed to the base 3 b.

The ceiling-embedded lighting device 1A further includes a translucent cover 7. The light-transmitting cover 7 is fixed to the housing 4. The light-transmissive cover 7 covers the entirety of the light source 2 and the reflector 6. The light from the light source 2 and the light reflected by the reflector 6 are transmitted through the translucent cover 7 and emitted to the outside of the ceiling-embedded illumination device 1A. The light-transmissive cover 7 reliably protects the light source 2 and the reflector 6 from dirt, water, or the like. By providing the light-transmissive cover 7, deterioration or failure of the light source 2 can be reliably prevented. The light-transmissive cover 7 is preferably made of a transparent material that allows directional transmission of light. Alternatively, the light-transmitting cover 7 may diffuse light. The light-transmitting cover 7 may be made of a resin material such as polycarbonate resin, acrylic resin, or polystyrene resin, or a glass material. The surface of the light-transmitting cover 7 may be subjected to a coating treatment, such as a hard coating treatment, which is advantageous for suppressing the deterioration with age. The light-transmitting cover 7 may also have waterproofness. A waterproof seal or adhesive may be provided at the joint between the translucent cover 7 and the housing 4. The sealing material or the adhesive may be made of, for example, a soft resin material, a silicone-based sealing material, a rubber-based material, or the like. As a modification, a lens for light distribution control may be used instead of the reflector 6 and the translucent cover 7, so that the amount of light emitted downward from the ceiling-embedded illumination device 1A can be increased. The lens is preferably made of a transparent material that allows directional transmission of light. Alternatively, the lens may diffuse light.

As shown in fig. 2, the housing 4 includes a cylindrical portion 4c having a cylindrical shape and a top surface portion 4d formed at an upper end of the cylindrical portion 4 c. The top surface portion 4d is formed with a second vent 4 b. The housing 4 includes a flange portion 4e protruding outward from the lower end of the cylindrical portion 4 c. The flange portion 4e is formed over the entire circumference of the lower end of the cylindrical portion 4 c. The lower surface of the top plate 100 is in contact with the upper surface of the flange portion 4 e. The edge of the hole formed in the top plate 100 contacts the corner between the outer surface of the cylindrical portion 4c and the flange portion 4 e. The cylindrical portion 4c of the housing 4 protrudes upward beyond the upper surface of the top plate 100. As a modification, the case 4 may have a prismatic cylindrical portion such as a quadrangular cylindrical portion, a pentagonal cylindrical portion, a hexagonal cylindrical portion, or an octagonal cylindrical portion, instead of the cylindrical portion 4 c.

The housing 4 includes an annular frame portion 4f and a plurality of connection portions 4 g. The frame 4f supports the outer periphery of the translucent cover 7. The frame portion 4f is provided inside the lower end of the cylindrical portion 4 c. The plurality of connecting portions 4g connect the lower end of the cylindrical portion 4c and the frame portion 4 f. The plurality of connecting portions 4g are provided at partially equal intervals in the circumferential direction of the cylindrical portion 4 c. Each connecting portion 4g protrudes inward from the lower end of the cylindrical portion 4c and is connected to the frame portion 4 f. The outer peripheral portion of the reflector 6 may be supported by the frame 4 f.

The first vent 4a corresponds to a hole surrounded by the lower end of the cylindrical portion 4c, the frame portion 4f, and the connecting portion 4 g. As shown in fig. 1, the first air vent 4a is located outside the reflector 6. By providing the first air vent 4a on the outer peripheral side of the reflector 6, loss of light emitted from the light source 2 can be prevented. In contrast, in the case where the reflector 6 is provided with the first air vent 4a, or in the case where the first air vent 4a is provided on the inner peripheral side of the reflector 6, light enters the first air vent 4a, and there is a possibility that loss of light increases as stray light.

The plurality of first vents 4a are arranged along the circumferential direction of the ceiling embedded lighting device 1A over the entire circumference. This can increase the total opening area of the first air vents 4a, and can more efficiently suck air from the indoor space 200 into the casing 4.

The case 4 is preferably made of a metal material having light weight and high thermal conductivity. Examples of such a metal material include aluminum, aluminum-based alloys, copper-based alloys, and stainless steel.

As shown in fig. 2, the heat sink 3 is coupled to the case 4 via a plurality of heat sink brackets 8. The radiator support 8 is provided locally at a plurality of positions in the circumferential direction of the cylindrical portion 4 c. Each radiator support 8 connects the base 3b to the inner surface of the cylindrical portion 4 c. The heat sink 3 is fixed with respect to the housing 4 by a heat sink bracket 8. The fixing method between these members may be any method such as caulking, screwing, bonding, welding, or brazing. In addition, when the heat sink 3 and the case 4 are integrally manufactured by, for example, an aluminum die casting method, it is not necessary to provide the heat sink holder 8 as a separate member.

A gap 9 through which an air flow can pass is formed between the inner surface of the cylindrical portion 4c and the base 3b of the heat sink 3 except for the position of the heat sink holder 8. The air sucked through the first air vent 4a can move upward of the base 3b through the gap 9.

A fixing member 10 is provided between the edge of the second air vent 4b of the casing 4 and the cooling fan 5. The cooling fan 5 is fixed to the housing 4 by a fixing member 10. The fixing member 10 has an effect of suppressing vibration and noise of the cooling fan 5. The fixing member 10 is preferably made of an elastic material such as a rubber material. This improves the vibration-proof performance of the fixing member 10 and reduces the weight.

The ceiling-embedded lighting device 1A is connected to a power supply device (not shown). The power supply device includes a light source drive circuit for lighting the light source 2 and a fan drive circuit for driving the cooling fan 5. The light source driving circuit includes a power supply circuit that converts ac power supplied from an ac power supply outside the ceiling-embedded lighting device 1A into dc power. The power supply circuit may include a switching power supply using a semiconductor switching element, for example. The ac power supply is typically a commercial power supply. The fan drive circuit supplies electric power to the motor of the cooling fan 5. The power supply device may be electrically and structurally connected to the ceiling-embedded lighting device 1A. The power supply device may be provided inside the ceiling-embedded illumination device 1A. Alternatively, the power supply device provided at a separate location may be connected to the ceiling-embedded lighting device 1A by wiring.

In the present embodiment, the second vent 4b is formed in the top portion of the housing 4, whereby the following effects can be obtained. The resistance to passage of the air flow inside the casing 4 can be reduced, and the ventilation volume can be increased.

In the present embodiment, the cooling fan 5 is disposed above the heat sink 3, whereby the following effects can be obtained. The ceiling embedded lighting device 1A can be reduced in overall diameter and can be easily installed in a hole formed in the top plate 100.

L1 in fig. 3 indicates the height of the heat sink 3. L2 indicates the distance between the inner surface of the case 4 and the heat sink 3 in the direction perpendicular to the top plate 100. That is, L2 represents the shortest distance between the inner surface of the top surface portion 4d of the case 4 and the upper end of the heat sink 3. L3 indicates the distance between the inner surface of the case 4 and the heat sink 3 in the direction parallel to the top plate 100. That is, L3 represents the shortest distance between the inner surface of the cylindrical portion 4c corresponding to the side surface portion of the case 4 and the heat sink 3. In this embodiment, L1 is greater than L2. L1 is greater than L3. This can provide the following effects. In the limited inner space of the housing 4, the heat sink 3 can be sufficiently enlarged. Since a passage for an airflow of an appropriate size is formed between the inner surface of the housing 4 and the heat sink 3, the airflow can be efficiently brought into contact with the heat sink 3.

In the present embodiment, by disposing the cooling fan 5 inside the second air vent 4b, the size of the entire ceiling-embedded illumination device 1A can be reduced, and the airflow generated by the cooling fan 5 can be used without waste. As a modification, the cooling fan 5 may be disposed inside or outside the casing 4, and the cooling fan 5 and the second air vent 4b may be connected by a duct.

In the present embodiment, the case 4 covers the entire heat sink 3, but as a modification, a part of the heat sink 3 may not be covered by the case 4. In this case, the case 4 may not include the second vent 4 b.

Embodiment mode 2

Next, embodiment 2 will be described with reference to fig. 4, focusing on differences from embodiment 1 described above, and the description of the same or corresponding portions will be simplified or omitted. Fig. 4 is a sectional perspective view of the ceiling embedded lighting device 1B of embodiment 2 as viewed from obliquely above. Fig. 4 corresponds to a cross-sectional view taken along a plane including the center line of the ceiling-embedded lighting device 1B.

The ceiling-embedded lighting device 1B shown in fig. 4 includes a heat sink 3B instead of the heat sink 3 of embodiment 1. The plurality of plate-shaped fins 3d provided in the heat sink 3B are arranged radially. That is, each fin 3d is disposed so as to extend radially outward from the center of the heat sink 3B.

According to embodiment 2, the following effects can be obtained in addition to the effects similar to embodiment 1. With the arrangement of the radial fins 3d as in the heat sink 3B, the pressure loss during operation of the cooling fan 5 is reduced because the resistance to airflow is smaller than that with the arrangement of the parallel fins 3a as in the heat sink 3. As a result, a larger air volume can be sucked into the ceiling-embedded illumination device 1B. This can further reduce the temperature of the light source 2.

Embodiment 3

Next, embodiment 3 will be described with reference to fig. 5, focusing on differences from embodiment 1 described above, and the description of the same or corresponding portions will be simplified or omitted. Fig. 5 is a sectional perspective view of the ceiling embedded lighting device 1C of embodiment 3 as viewed from obliquely above. Fig. 5 corresponds to a cross-sectional view taken along a plane including the center line of the ceiling-embedded lighting device 1C.

The ceiling-embedded lighting device 1C shown in fig. 5 includes a heat sink 3C instead of the heat sink 3 of embodiment 1. The heat sink 3C includes a plurality of fins 3e having pin shapes.

According to embodiment 3, the following effects can be obtained in addition to the effects similar to embodiment 1. According to the pin-shaped heat radiation fins 3e of the heat sink 3C, the pressure loss during operation of the cooling fan 5 is reduced because the resistance to passage of the air flow is smaller than that of the plate-shaped heat radiation fins 3a of the heat sink 3. As a result, a larger air volume can be sucked into the ceiling-embedded illumination device 1C. This can further reduce the temperature of the light source 2.

Embodiment 4

Next, embodiment 4 will be described with reference to fig. 6 and 7, focusing on differences from the above-described embodiments, and the description of the same or corresponding portions will be simplified or omitted. Fig. 6 is a perspective view of the ceiling-embedded lighting device 1D according to embodiment 4, as viewed obliquely from below. Fig. 7 is a cross-sectional side view of the ceiling embedded lighting device 1D of embodiment 4. Fig. 6 and 7 correspond to cross-sectional views taken along a plane including the center line of the ceiling embedded lighting device 1D.

The ceiling-embedded lighting device 1D shown in these figures includes a heat sink 3D instead of the heat sink 3 of embodiment 1. The heat sink 3D includes a plurality of pin-shaped fins 3e and a base 3b that supports the root portions of the fins 3 e. An opening 3f is formed in the base 3 b. As shown in fig. 6, the plurality of openings 3f are arranged in the circumferential direction at positions away from the center of the base 3 b. As shown in fig. 7, at least a part of the airflow flowing in from the first vent 4a passes through the opening 3f of the base 3 b. The airflow passing through the opening 3f flows along the surface of the heat sink 3e, and is then discharged to the space 300 behind the ceiling through the cooling fan 5 and the second air vent 4 b. The opening 3f is preferably provided at a position capable of more efficiently cooling the light source 2 in conformity with the shape of the heat sink 3 e.

According to embodiment 4, the following effects can be obtained in addition to the effects similar to embodiment 1. By providing the opening 3f of the base 3b, the air sucked through the first air vent 4a can more smoothly pass through the internal space of the housing 4, and therefore, the pressure loss can be further reduced. This can further improve the cooling of the light source 2. The base 3b can be made lightweight according to the amount of the opening 3f formed. The heat sink 3D can be reduced in weight by eliminating the fins 3e directly above the opening 3 f. As a modification, the opening 3f may be formed in the base 3B of the

heat sink

3 or 3B having the plate-like

heat radiating fins

3a or 3d as in embodiment 1 or 2.

Embodiment 5

Next, embodiment 5 will be described with reference to fig. 8, focusing on differences from embodiment 1 described above, and the description of the same or corresponding portions will be simplified or omitted. Fig. 8 is a sectional perspective view of the ceiling embedded lighting device 1E of embodiment 5 as viewed from obliquely above. Fig. 8 corresponds to a cross-sectional view taken along a plane including the center line of the ceiling-embedded lighting device 1E.

The ceiling-embedded lighting device 1E shown in fig. 8 includes a heat sink 3E and a housing 4E instead of the heat sink 3 and the housing 4 of embodiment 1. The heat sink 3E includes a plurality of fins 3E having pin shapes. An opening 3f is formed in the base portion 3b of the heat sink 3E. As a modification, the heat sink 3E may include plate-shaped fins.

The housing 4E has a second vent 4 h. The second air vent 4h is formed in a side surface portion of the housing 4. The second vent 4h is a hole or opening formed in a side wall of the cylindrical portion 4c of the housing 4. No vent is formed in the top surface 4d of the case 4.

The cooling fan 5 is disposed adjacent to the side of the radiator 3E. The cooling fan 5 is disposed inside the casing 4. The cooling fan 5 faces the second air vent 4 h. The center line of the cooling fan 5 is parallel to the top plate 100. The rotation axis of the propeller fan of the cooling fan 5 is parallel to the top plate 100. The cooling fan 5 may be fixed to the base 3b of the heat sink 3E. The cooling fan 5 may also be fixed to the housing 4.

When the cooling fan 5 operates, air is taken in from the first air vent 4 a. At least a part of the airflow flowing in from the first vent 4a passes through the opening 3f of the base 3 b. After passing between the fins 3E of the radiator 3E, the airflow passes through the cooling fan 5 and the second air vent 4h, and is discharged to the space 300 behind the ceiling.

According to embodiment 5, the following effects can be obtained in addition to the effects similar to embodiment 4. The cooling fan 5 is not disposed above the heat sink 3E, but is disposed adjacent to the side of the heat sink 3E, whereby the overall height of the ceiling-embedded lighting device 1E can be kept low. Therefore, the ceiling-back space 300 having a small height dimension can be easily provided. If the range X in which the cooling fan 5 is present and the range Y in which the radiator 3E is present are configured to overlap at a position in the direction perpendicular to the top plate 100, effects similar to the above-described effects can be obtained.

By forming the second air vent 4h in the side surface portion of the housing 4, the following effects can be obtained. The direction of the airflow blown out from the second air vent 4h is substantially parallel to the top plate 100. In the space 300 behind the ceiling having a small size in the height direction, the airflow blown out from the second air vent 4h does not collide with the top inner surface of the space 300 behind the ceiling. Therefore, the pressure loss during operation of the cooling fan 5 can be reduced, and a larger air volume can be drawn into the ceiling-embedded illumination device 1E. This can further reduce the temperature of the light source 2.

Embodiment 6

Next, embodiment 6 will be described with reference to fig. 9, focusing on differences from the above-described embodiments, and the description of the same or corresponding portions will be simplified or omitted. Fig. 9 is a sectional perspective view of the ceiling embedded lighting device 1F of embodiment 6 as viewed from obliquely above. Fig. 9 corresponds to a cross-sectional view taken along a plane including the center line of the ceiling-embedded lighting device 1F.

The ceiling-embedded lighting device 1F shown in fig. 9 has the same configuration as the ceiling-embedded lighting device 1E of embodiment 5, except that it further includes the power supply device 12. The power supply device 12 has a light source drive circuit for lighting the light source 2. The power supply device 12 may further include a fan drive circuit that drives the cooling fan 5. In the example shown in fig. 9, the power supply device 12 includes a rectangular parallelepiped housing and a circuit board disposed inside the housing. In fig. 9, a cross section of the power supply device 12 is shown simplified. The power supply device 12 is fixed to the housing 4 via a bracket, not shown. The electronic circuit board of the power supply device 12 includes, for example, electric components that generate heat, such as a semiconductor element, a reactor, a resistor, and a capacitor.

According to embodiment 6, the following effects can be obtained in addition to the effects similar to embodiment 5. The power supply device 12 is disposed at a position in contact with the airflow generated by the cooling fan 5. This enables the power supply device 12 to be cooled using the airflow generated by the cooling fan 5. As a result, the temperature of the heat-generating electrical components of the power supply device 12 can be reduced, and the efficiency of the power supply device 12 can be improved.

In the illustrated example, the power supply device 12 is disposed outside the casing 4, but the power supply device 12 may be disposed inside the casing 4. In the illustrated example, the power supply device 12 is disposed on the downstream side of the cooling fan 5, but as a modification, the power supply device 12 may be disposed on the upstream side of the cooling fan 5. For example, the power supply device 12 may be disposed between the heat sink 3E and the cooling fan 5 on the path of the air flow.

Embodiment 7

Next, embodiment 7 will be described with reference to fig. 10, focusing on differences from embodiment 1 described above, and the description of the same or corresponding portions will be simplified or omitted. Fig. 10 is a plan view of the ceiling-embedded lighting device 1G according to embodiment 7.

The ceiling-embedded illumination device 1G of embodiment 7 has the same configuration as the ceiling-embedded illumination device 1E of embodiment 5, except that a heat sink 3G is provided instead of the heat sink 3E. Fig. 10 shows a state in which the housing 4E of the ceiling-embedded lighting device 1G is removed. The dotted line with arrows in fig. 10 indicates a part of the flow of air when the cooling fan 5 is operating.

As shown in fig. 10, the heat sink 3G includes a plurality of plate-shaped fins 3G and a base 3b that supports the root portions of the fins 3G. An air passage 3h is formed between the fins 3 g. An opening 3f is formed in the base portion 3b of the heat sink 3G. The air having passed through the opening 3f passes through the air passage 3h, is sucked into the cooling fan 5, and is discharged into the space 300 behind the ceiling. Each air passage 3h has a first end located closer to opening 3f than cooling fan 5 and a second end located closer to cooling fan 5 than opening 3 f. The air flows from the first end toward the second end of each air passage 3 h. The width of each air passage 3h decreases from the first end toward the second end. The "width of the air passage 3 h" is a length in a direction perpendicular to the air flow direction and parallel to the base 3 b.

According to embodiment 7, the following effects can be obtained in addition to the effects similar to embodiment 5. By forming the heat radiation fins 3G to function as air guide plates, the pressure loss during operation of the cooling fan 5 can be reduced, and a large air volume can be drawn into the ceiling-embedded illumination device 1G. This can further reduce the temperature of the light source 2.

Embodiment 8

Next, embodiment 8 will be described with reference to fig. 11 and 12, focusing on differences from the above-described embodiments, and the description of the same or corresponding portions will be simplified or omitted. Fig. 11 is a perspective view of the ceiling-embedded lighting device 1H according to embodiment 8, as viewed obliquely from below. Fig. 12 is a sectional perspective view of the ceiling embedded lighting device 1H of embodiment 8 as viewed from obliquely above. Fig. 12 corresponds to a cross-sectional view taken along a plane including the center line of the ceiling-embedded lighting device 1H. The ceiling-embedded lighting device 1H shown in these figures has the same configuration as the ceiling-embedded lighting device 1A of embodiment 1, except that the housing 4H is provided instead of the housing 4.

The housing 4H includes a first vent hole 4i and a flange 4m instead of the first vent hole 4a and the flange 4e, as compared with the housing 4 of embodiment 1. When the ceiling-embedded illumination device 1H is viewed from directly below, the hole 4k that becomes the entrance of the first vent 4i is not visible. As shown in fig. 11, the flange portion 4m protrudes outward from the lower end of the cylindrical portion 4 c. The outer peripheral surface 4n of the flange portion 4m is parallel to the center line of the ceiling-embedded lighting device 1H. The outer peripheral surface 4n is perpendicular to the top plate 100. A hole 4k serving as an inlet of the first air vent 4i is formed in the outer peripheral surface 4 n. Therefore, when the ceiling-embedded illumination device 1H is viewed from directly below, the hole 4k that becomes the entrance of the first vent 4i is not visible.

According to embodiment 8, the following effects can be obtained in addition to the effects similar to embodiment 1. When the ceiling-embedded illumination device 1H is viewed from directly below, the hole 4k that becomes the entrance of the first air vent 4i is not visible, and therefore, it is possible to reliably prevent the observer from feeling discomfort. That is, the design of the ceiling-embedded illumination device 1H can be improved.

As shown in fig. 11, the hole 4k that becomes the inlet of the first vent 4i has an elongated shape extending along the circumferential direction of the flange portion 4 m. The case 4 has a bottom surface portion 4 p. A light-transmitting cover 7 is disposed inside a circular opening formed in the center of the bottom surface portion 4 p. The bottom surface portion 4p is smoothly connected to the lower surface of the flange portion 4m without any step. As shown in fig. 12, the bottom surface portion 4p covers a hole serving as an outlet of the first vent 4i from below. Therefore, when the ceiling-embedded lighting device 1H is viewed from directly below, the hole that becomes the outlet of the first vent 4i is not visible.

Embodiment 9

Next, with reference to fig. 13, embodiment 9 will be described focusing on differences from the above-described embodiments, and the description of the same or corresponding portions will be simplified or omitted. Fig. 13 is a functional block diagram of the ceiling-embedded illumination device 1J of embodiment 9. The ceiling embedded illumination device 1J of embodiment 9 has a mechanical structure similar to that of any of the ceiling embedded illumination devices 1A to 1H described above, and therefore, a drawing showing the mechanical structure is omitted. In the following description, the ceiling embedded lighting device 1J has a mechanical structure similar to that of the ceiling embedded lighting device 1A of embodiment 1.

In embodiment 9, the cooling fan 5 can be operated in the first mode and the second mode. For example, in the first mode, the cooling fan 5 rotates in the forward direction, and in the second mode, the cooling fan 5 rotates in the reverse direction. When the cooling fan 5 is operated in the first mode, air is taken in from the indoor space 200 below the top plate 100 into the internal space of the casing 4 through the first ventilation port 4a, and the taken-in air is discharged into the space 300 behind the ceiling through the second ventilation port 4 b. The airflow when the cooling fan 5 is operated in the first mode is the same as that in embodiment 1.

When the cooling fan 5 is operated in the second mode, air is taken in from the space 300 behind the ceiling through the second air vent 4b into the internal space of the casing 4, and the taken-in air is discharged through the first air vent 4a into the indoor space 200 below the top plate 100. That is, the airflow when the cooling fan 5 is operated in the second mode flows in the opposite direction to that in embodiment 1.

As shown in fig. 13, the ceiling-embedded illumination device 1J includes a power supply device 13. The power supply device 13 includes a light source drive circuit 13a that supplies a current for lighting the light source 2, a fan drive circuit 13b that supplies a current for driving the cooling fan 5, and a control unit 13 e. The control section 13e drives the light source 2 via the light source driving circuit 13 a. The control unit 13e drives the cooling fan 5 via the fan drive circuit 13 b. The control unit 13e includes a processor 13f and a memory 13 g. Typically, the control unit 13e has a structure including a microcomputer.

The light source driving circuit 13a causes a current to flow into the light source 2. The light source driving circuit 13a includes a power supply circuit that converts ac power supplied from an external ac power supply 500 into dc power. The power supply circuit may include a switching power supply using a semiconductor switching element, for example. The ac power supply 500 is typically a commercial power supply. The light source driving circuit 13a adjusts the current flowing in the light source 2 in accordance with a command from the control unit 13e, and can adjust the light beam emitted from the light source 2. Thereby, the illuminance and brightness of the ceiling-embedded illumination device 1J can be adjusted.

The fan drive circuit 13b supplies electric power to the motor of the cooling fan 5 in accordance with a command from the control unit 13 e. The fan drive circuit 13b operates the cooling fan 5 in the first mode or the second mode in accordance with a command from the control unit 13 e. The fan drive circuit 13b may adjust at least one of the current, voltage, and frequency of the electric power supplied to the motor of the cooling fan 5, thereby adjusting the rotation speed of the cooling fan 5.

The transmission unit 60 transmits first information relating to the temperature of the indoor space 200 below the ceiling board 100 and second information relating to the temperature of the space 300 behind the ceiling to the control unit 13 e. The transmitter 60 may be configured by a first temperature sensor and a second temperature sensor (both not shown) provided in the ceiling-embedded lighting device 1J. In this case, the first temperature sensor may be configured to detect the air temperature in the indoor space 200, and the second temperature sensor may be configured to detect the air temperature in the space 300 behind the ceiling. Alternatively, a controller different from the ceiling-embedded illumination device 1J may include the transmission unit 60. For example, when a controller (not shown) of a lighting control system that controls a plurality of lighting devices including the ceiling-embedded lighting device 1J is connected to the control unit 13e by wired communication or wireless communication, the control unit 13e may receive the first information and the second information from the transmission unit 60 provided in the controller via a communication means.

The control unit 13e switches the first mode and the second mode of the cooling fan 5 based on the first information and the second information received from the transmission unit 60. For example, the following is also possible. When the temperature of the indoor space 200 is lower than the temperature of the space 300 behind the ceiling, the controller 13e operates the cooling fan 5 in the first mode. When the temperature of the space 300 behind the ceiling is lower than the temperature of the indoor space 200, the controller 13e operates the cooling fan 5 in the second mode.

In general, the temperature of the indoor space 200 is often lower than the temperature of the space 300 behind the ceiling. However, in the case of using heating in winter or the like, the temperature of the space 300 behind the ceiling may be lower than the indoor space 200. When the temperature of the space 300 behind the ceiling is lower than that of the indoor space 200, if the cooling fan 5 is operated in the second mode, the low-temperature air in the space 300 behind the ceiling is sucked into the internal space of the casing 4 through the second air vent 4b, and therefore the radiator 3 can be cooled efficiently. Instead of the configuration in which the control unit 13e automatically switches the first mode and the second mode of the cooling fan 5, the first mode and the second mode of the cooling fan 5 may be switched by a manual switch.

Description of the reference numerals

1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1J ceiling embedded lighting, 2 light source, 3B, 3C, 3D, 3E, 3G heat sink, 3a, 3D, 3E, 3G heat sink, 3B base, 3F opening, 3G heat sink, 3H air path, 4E, 4H housing, 4a, 4i first vent, 4B, 4H second vent, 5 cooling fan, 6 reflector, 7 light transmissive cover, 12, 13 power supply, 100 ceiling, 200 indoor space, 300 ceiling back space.

Claims

1. A ceiling embedded lighting device, wherein,

the ceiling embedded type lighting device comprises:

a light source;

a heat sink having a plurality of heat radiating fins for radiating heat generated by the light source;

a housing having a first vent and at least partially covering the heat sink;

a cooling fan that generates an air flow for cooling the heat sink; and

a control part connected with the cooling fan,

the volume of the space occupied by the cooling fan is smaller than the volume of the space occupied by the heat sink,

the inner space of the housing is in fluid communication with the space below the ceiling via the first air vent,

the space behind the ceiling is a space above the ceiling and outside the housing,

the cooling fan sucks air from a space below the ceiling into the inner space of the housing through the first air port, and discharges the sucked air to the space behind the ceiling,

the cooling fan is operable in a first mode and a second mode,

when the cooling fan is operated in the first mode, air is taken in from a space below the ceiling to the internal space of the housing through the first air vent, and the taken-in air is discharged to the space behind the ceiling,

when the cooling fan is operated in the second mode, air is sucked from the space behind the ceiling into the internal space of the housing, and the sucked air is discharged into the space below the ceiling through the first air vent,

the control unit switches the first mode and the second mode based on first information relating to a temperature of a space below the ceiling and second information relating to a temperature of a space behind the ceiling.

2. The ceiling buried lighting apparatus of claim 1,

the ceiling embedded type lighting device is provided with a reflector for reflecting the light from the light source,

the first vent hole is located outside the reflector.

3. The ceiling buried lighting apparatus of claim 1 or 2,

the housing has a second vent opening therein,

the interior space of the housing is in fluid communication with the under-ceiling space via the second vent,

the cooling fan discharges the air drawn in to the space behind the ceiling through the second air vent.

4. The ceiling buried lighting apparatus of claim 3,

the second vent is formed in the top of the housing.

5. The ceiling buried lighting apparatus of claim 3,

the second vent is formed in a side surface portion of the housing.

6. The ceiling buried lighting apparatus of claim 3,

the cooling fan is disposed inside the second air vent.

7. The ceiling buried lighting apparatus of claim 1 or 2,

the heat sink includes a base for supporting the root portions of the plurality of fins,

the base is provided with an opening, and the opening is arranged on the base,

air flowing in from the first vent passes through the opening of the base.

8. The ceiling buried lighting apparatus of claim 1 or 2,

the cooling fan is disposed adjacent to the heat sink.

9. The ceiling buried lighting apparatus of claim 1 or 2,

the range in which the cooling fan is present and the range in which the radiator is present have an overlap at a position in a direction perpendicular to the ceiling.

10. The ceiling buried lighting apparatus of claim 1 or 2,

the cooling fan is disposed above the heat sink.

11. The ceiling buried lighting apparatus of claim 1 or 2,

the ceiling embedded lighting device is configured such that, when the ceiling embedded lighting device is viewed from directly below, the hole that becomes the inlet of the first air vent is not visible.

12. The ceiling buried lighting apparatus of claim 1 or 2,

the ceiling embedded type lighting device is provided with a power supply device, the power supply device is provided with a light source driving circuit for lighting the light source,

the power supply device is disposed in a position in contact with the airflow generated by the cooling fan.

13. The ceiling buried lighting apparatus of claim 1 or 2,

the height of the heat sink is greater than the distance between the inner surface of the housing and the heat sink.