JP2015005365A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device having a heat sink structure capable of minimizing the influence of hot air, heated by heat radiated from fins, on a power supply located above the heat sink.SOLUTION: In a lighting device 10 having a heat sink 3 on which a light source is attached on the lower surface side thereof and which dissipates heat generated from the light source, an opening part is formed in the heat sink 3 so as to pass through the heat sink 3 from bottom to top. The lighting device includes a cover part 90 formed with a plurality of vent holes 71 communicating with the opening part, and attached to the heat sink 3 so as to cover the lower surface side of the heat sink 3. The cover part 90 includes an acrylic cover 6 formed with a cover opening at a portion facing the opening part, and a cover attachment plate 7 made of a metal, formed with the plurality of vent holes 71 and arranged so as to close the cover opening formed in the acrylic cover 6.

Description

  The present invention relates to a lighting fixture including a heat sink that dissipates heat generated by an LED (Light / Emitting / Diode) light source.

The LED lighting fixture employs a heat sink for heat dissipation and member attachment. In recent years, the amount of heat is increased by increasing the luminous flux of the light source and the input power, and the heat sink has been increased in size. Due to the increase in size, there are concerns about increased costs due to increased instrument mass, increased initial costs, and safety concerns (falling).
Moreover, the lighting fixture for direct attachment to the ceiling has the LED lighting power source necessary for lighting the LED light source above the LED light source that emits light due to its configuration. Therefore, the LED lighting power source is affected by the heat from the LED light source.

  Patent Document 1 discloses a lighting fixture that exposes fins of a heat sink that plays a role of heat dissipation, and increases a surface area in contact with ambient air. This lighting fixture uses a chimney effect by providing a processing hole in the sheet metal covering the heat sink so that the fin of the heat sink contacts the surrounding air to expose the heat sink, and providing a pipe-shaped heat sink in the center of the heat sink. It is configured.

Patent Document 2 discloses a lighting fixture including a heat sink that promotes natural convection by forming a metal plate in a spiral shape. The metal plate has a plurality of holes, and the heat dissipation performance is changed depending on the number of windings of the sheet metal. The metal plate is provided with a plurality of arc-shaped fins cut and raised inward in the radial direction, and the radiant heat from the fins is directed inward in the radial direction. It gradually increases toward the inner side in the direction, and is highest at the center in the radial direction. For this reason, it can be made to act on the direction which maintains the conditions of making the temperature of radial center the highest with a fin. In addition, each of the plurality of fins is cut and raised so that a line connecting both end portions extends in parallel with the central axis direction of the heat sink, and an angle formed between the surface of each fin and the tangent to the wound metal plate is an acute angle. Since it is cut and raised from the heat sink, the surface of each fin guides the convection air in the heat sink toward the radial center of the heat sink, so that the air flow velocity can be exerted in a direction that does not decelerate as much as possible. .
The lighting fixture of Patent Document 2 includes a heat sink and a printed wiring board on which a heating element is mounted on the lower surface, and the heat sink is perpendicular to the heating element on the upper surface of the printed wiring board and generates the heat. The body is mounted with the other end side in the central axis direction facing down at a position located at the center in the radial direction. Therefore, the temperature of the air in the heat sink and the heat sink can be increased in the radial center of the heat sink with respect to the radially outer side, and the temperature difference in the central axis direction at the radial center can be increased. For this reason, the chimney effect at the radial center of the heat sink can be made larger than the chimney effect at the radially outer side, the flow velocity of the ascending airflow can be increased at the center, and the pressure gradually decreases from the radially outer side toward the center. A gradient can be generated.

Special table 2010-526416 JP 2009-016674 A

  In the lighting fixture of patent document 1, when the calorie | heat amount of a light source becomes large, there exists a subject that only the height of a heat sink can be raised to a height direction. Further, in Patent Document 2, as the amount of light increases, there is a problem that convection hardly flows in the center of the instrument, and heat accumulates in the center of the instrument.

  An object of the present invention is to provide a luminaire having a heat sink structure that can minimize the influence of the hot air radiated from the fins on the power supply above the heat sink.

  The lighting fixture according to the present embodiment includes a heat sink that attaches a light source to the lower surface side and that dissipates heat generated from the light source, and the heat sink has a heat sink through-hole penetrating from below to above. A cover portion formed with a plurality of communication holes communicating with the heat sink through hole, the cover portion being attached to the heat sink so as to cover a lower surface side of the heat sink.

  According to the lighting apparatus according to the present invention, by providing the cover portion in which the communication hole communicating with the heat sink through hole is formed, the flow of hot air radiated from the heat sink does not collect in the center, and the power source is located above the heat sink. There is an effect that the influence of heat can be reduced.

1 is an exploded perspective view of a lighting fixture 10 according to Embodiment 1. FIG. It is an assembly drawing of the lighting fixture 10 which concerns on Embodiment 1, (a) is a perspective view, (b) is a front view. 3 is an enlarged perspective view of a cover mounting plate 7 that is attached to the heat sink 3 of the lighting fixture 10 according to Embodiment 1. FIG. FIG. 6 is a schematic diagram showing the air flow when the cover mounting plate 7 in the lighting fixture 10 according to Embodiment 1 is not used. FIG. 6 is a schematic diagram showing the air flow when the cover mounting plate 7 in the lighting fixture 10 according to Embodiment 1 is used.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the embodiments, directions such as “up”, “down”, “left”, “right”, “front”, “back”, “front”, “back” are for convenience of explanation. It is only described as such, and does not limit the arrangement or orientation of devices, instruments, parts, and the like.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view of a lighting fixture 10 according to the present embodiment. FIG. 2 is an assembly view of the lighting fixture 10 according to the present embodiment, in which (a) is a perspective view and (b) is a front view. FIG. 3 is an enlarged perspective view of the cover mounting plate 7 of the lighting fixture 10 according to the present embodiment.
The whole structure of the lighting fixture 10 which concerns on this Embodiment is demonstrated using FIGS. 1-3.

As shown in FIG. 1, the luminaire 10 includes an arm 1, a light source lighting power source 2, a heat sink 3, a light source 4, a reflector 5, a cover portion 90, and a cover mounting frame 9.
The cover part 90 includes an acrylic cover 6 (light transmissive plate part) and a cover mounting plate 7 (metal plate part).

As shown in FIGS. 2A and 2B, the arm 1 is a long metal plate bent in a U shape, and both ends of the U shape are fixed to the heat sink 3. When attaching the lighting fixture 10 to fixture mounting surfaces, such as a ceiling surface, the center part of the arm 1 is fixed to a ceiling surface.
The light source lighting power source 2 (power source device) is a power source necessary for lighting the light source 4. As shown in FIGS. 2A and 2B, the light source lighting power source 2 is disposed above the heat sink 3.
The light source 4 is, for example, an LED. The light source 4 is attached to a light source attachment surface 31 provided on the lower surface side of the heat sink 3. The light source 4 is a heating element that generates heat. The present embodiment can be applied not only to LEDs but also to light sources other than LEDs such as incandescent lamps, fluorescent lamps, and halogen lamps.

The heat sink 3 is integrally formed of a metal having high thermal conductivity, such as aluminum.
The heat sink 3 includes a light source attachment surface 31 to which the light source 4 is attached on the lower surface side. A fin 33 that radiates heat generated from the light source 4 is provided on the opposite side of the light source mounting surface 31 (upper side of the heat sink 3).
A portion of the heat sink 3 other than the fins 33 is referred to as a light source mounting portion 37. The lower surface side of the light source mounting portion 37 is a light source mounting surface 31. The upper side of the light source mounting portion 37 is a light source mounting upper portion 38 (see FIG. 2B). On the light source mounting surface 31, the light source 4 is arranged in a circle around an opening 32 described later. The heat generated from the light source 4 is transmitted from the light source mounting surface 31 to the light source mounting portion 37 and from the light source mounting portion 37 to the fins 33. The fins 33 radiate the heat transmitted from the light source mounting portion 37.

  The heat sink 3 is formed with an opening 32 (heat sink through hole) penetrating from below to above. The opening 32 penetrates the light source mounting portion 37 in the vertical direction. The opening 32 is formed in the central portion of the heat sink 3 (light source mounting portion 37) in order to promote natural convection of air. The opening 32 is a hole that penetrates from a substantially central portion of the light source attachment surface 31 of the light source attachment portion 37 to a substantially central portion of the light source attachment upper portion 38. Due to the openings 32, the heat dissipated from the fins 33 is convected by the natural convection of the air without staying at the center.

As shown in FIG. 1, the light source mounting surface 31 has a ring shape (doughnut shape, annular shape) with the opening portion 32 as a central portion. The light source 4 is annularly arranged around the opening 32. The peripheral edge of the light source mounting surface 31 forms a peripheral wall portion 36 protruding to the light irradiation direction side.
The heat sink 3 includes an opening wall portion 34 that protrudes in a cylindrical shape in the light irradiation direction at the center of the light source mounting surface 31. The opening wall portion 34 is a wall portion in which the peripheral edge of the opening portion 32 protrudes downward. The inside of the cylindrical opening wall 34 is an opening 32. The tip of the opening wall 34 on the light irradiation direction side is an entrance of the opening 32.

The reflection plate 5 reflects the light emitted from the light source 4 and enhances the illumination effect. The reflection plate 5 has a ring shape that is attached to face the light source attachment surface 31. The reflector 5 has a reflector opening 51 formed in the center.
FIG. 2A shows a state in which the acrylic cover 6 is transparent and the reflection plate 5 and the opening wall portion 34 in the back of the acrylic cover 6 are visible. As shown in FIG. 2A, the opening wall portion 34 of the heat sink 3 passes through the reflector plate opening 51.
The reflection plate 5 has a light source opening 52 formed at a position corresponding to the light source 4, and reflects light emitted from the light source 4 by a reflection portion formed at the edge of the light source opening 52.

The acrylic cover 6 is a transparent or translucent cover formed of a resin such as acrylic. The acrylic cover 6 is an annular (doughnut-shaped) plate in which a cover opening 61 (opening) is formed at a portion facing the opening 32 of the heat sink 3.
The acrylic cover 6 is a cover that covers the light source mounting surface 31 that is the lower surface side of the heat sink 3 and covers the light source 4 and the reflection plate 5 that are mounted on the light source mounting surface 31.
The acrylic cover 6 may not be plate-shaped as long as it covers the lower surface side of the heat sink 3, and may be hemispherical, spherical, bulb-shaped, or the like.
FIG. 2A shows a state where the cover is a transparent cover. In the acrylic cover 6, a cover opening 61 is formed at a portion facing the opening 32 of the heat sink 3 at the center. The edge portion of the cover opening 61 is defined as a cover opening edge portion 62. From the cover opening 61, the front end 39 of the opening wall 34 is exposed. The front end portion 39 of the opening wall portion 34 is a portion that hits the lower entrance of the opening portion 32.

  The cover mounting plate 7 is a metal plate such as aluminum, for example. In the present embodiment, the cover mounting plate 7 is a circular metal plate, but the shape may be other shapes such as a polygon or an ellipse. Further, the cover mounting plate 7 may not be made of metal, but is preferably made of a heat radiating material so that the heat radiated from the fins 33 can be further radiated.

  The cover mounting plate 7 is fixed to the heat sink 3 while pressing the acrylic cover 6 from below to the heat sink 3 side. That is, the cover mounting plate 7 has an opening wall with the cover opening edge 62 of the acrylic cover 6 sandwiched between the outer peripheral edge 73 (see FIG. 3) on the heat sink 3 side and the vicinity of the tip 39 of the opening wall 34. Screwed to the tip 39 of the portion 34.

  As described above, the cover unit 90 includes the acrylic cover 6 that covers the light source 4 and the cover mounting plate 7 that is disposed so as to close the cover opening of the acrylic cover 6.

As shown in FIG. 3, the cover mounting plate 7 has four screw holes 72 and a plurality of air holes 71 (communication holes) other than the four screw holes 72. The air hole 71 is a hole communicating with the opening 32 (heat sink through hole).
As shown in FIG. 3, a line connecting two opposing screw holes 72 is a BB line. Further, a line that is substantially orthogonal to the BB line and connects two opposing screw holes 72 is defined as a CC line.
Two opposing screw holes 72 formed in the vicinity of the outer peripheral edge are formed on the BB line. Two opposing screw holes 72 formed in the vicinity of the outer peripheral edge and four air holes 71 formed on the CC line inside the screw hole 72 are formed on the CC line. ing. The four air holes 71 formed on the CC line are formed two by two with the central portion (central region 74) of the cover mounting plate 7 interposed therebetween.

A central region 74 in which neither the screw hole 72 nor the air hole 71 is formed is provided at the center of the cover mounting plate 7. In addition, on the BB line, a closed region 76 in which neither the screw hole 72 nor the air hole 71 is formed is provided outside the central region 74. Twelve air holes 71 are formed in each fan region 75 of the four fan regions 75 divided by the BB line and the C-C line, avoiding the central region 74 and the blocking region 76. Yes. Therefore, the air holes 71 in the four fan-shaped regions 75 are 48 (12 × 4), and the air holes 71 on the CC line are four, so that 52 air holes 71 are formed as a whole. Yes.
However, the number and arrangement of the screw holes 72 and the air holes 71 are not limited to the above and can be changed as appropriate.

  The cover attaching plate 7 is fixed to the heat sink 3 by attaching the screw 8 to the heat sink 3 through the screw hole 72. At this time, since the outer peripheral edge 73 of the surface of the cover mounting plate 7 on the heat sink 3 side and the cover opening edge 62 of the cover opening 61 of the acrylic cover 6 are overlapped, the central portion of the acrylic cover 6 is covered by the cover mounting plate 7. Is fixed. In this way, the acrylic cover 6 is attached to the heat sink 3.

The cover mounting frame 9 is fixed to the edge 35 of the heat sink 3 with the peripheral edge of the acrylic cover 6 sandwiched between the cover mounting frame 9 and the edge 35 of the heat sink 3 on the light irradiation direction side. The peripheral edge portion of the acrylic cover 6 is fixed by the cover mounting frame 9.
As described above, the cover mounting plate 7 radiates heat transmitted from the heat sink 3 by being fixed to the heat sink 3, and also provides new convection to the hot air flowing through the central portion of the heat sink 3 through the plurality of air holes 71. Can be given.

Next, the flow of air in the lighting fixture 10 according to the present embodiment will be described.
FIG. 4 is a schematic diagram showing the air flow when the cover mounting plate 7 is not used in the lighting fixture 10 according to the present embodiment. FIG. 5 is a schematic diagram showing an air flow when the cover mounting plate 7 in the lighting apparatus 10 according to the present embodiment is used.
4 and 5, the temperature change stage is indicated by six levels T1 to T6.

As shown in FIG. 4, when the cover mounting plate 7 is not used, that is, when the air hole 71 is not provided in the cover portion 90, the heat radiated from the fins 33 flows upward in a high temperature state. . As a result, high-temperature air reaches the light source lighting power source 2 above the fins 33.
As shown in FIG. 4, air at a temperature of T6 level is mainly in contact with the lower portion of the light source lighting power source 2.

As shown in FIG. 5, when the cover mounting plate 7 is used, the temperature of the air reaching the light source lighting power source 2 is lower than that in the case of FIG. Air at a temperature of T4 to T5 level is mainly in contact with the lower part of the light source lighting power supply 2, and air at a temperature of T6 level is not in contact therewith.
This is because the heat radiated from the fins 33 and flowing to the center of the heat sink 3 is further radiated by the cover mounting plate 7 which is a metal plate. Further, the plurality of air holes 71 formed in the cover mounting plate 7 generate new convection in the air inside and around the heat sink 3 to lower the temperature of the air flowing upward.

As described above, the plurality of air holes 71 of the cover mounting plate 7 communicate with the cover opening 61 of the acrylic cover 6 and also with the opening 32 of the heat sink 3. Depending on the number or arrangement of the holes 71, the heat flow to the light source lighting power supply 2 arranged above the fins 33 can be freely set.
In FIG. 3, the air hole 71 is not formed in the central region 74 of the cover mounting plate 7, but the air hole 71 may be formed uniformly in the entire cover mounting plate 7.
Alternatively, the air hole 71 may be formed in a circular shape near the periphery of the cover mounting plate 7, and the air hole 71 may be formed in a further circular shape inside the circular shape.
Any number or arrangement of the air holes 71 to be processed in the cover mounting plate 7 may be used as long as new air convection is generated in and around the heat sink 3.

  As described above, the lighting fixture according to the present embodiment increases the heat radiation area by applying additional processing to the cover mounting plate 7 attached to the heat sink 3 for the method of dissipating the heat of the light source 4 that is a heat source. The flow of air radiated from the lighting fixture can be changed. This cover mounting plate 7 (metal plate) mounted on the heat sink 3 makes it possible to reduce the influence of heat on the light source lighting power source 2 without collecting the flow of hot air radiated in the center. The cover mounting plate 7 serves as a member for mounting the acrylic cover 6 and a member for preventing thermal influence that changes the air flow. Therefore, it is possible to reduce the influence of the heat on the power supply device without increasing the number of parts.

  In the present embodiment, the lighting fixture 10 having the circular light source mounting surface 31 has been described. However, the present embodiment can be applied to a lighting fixture having a long light source mounting surface, an elliptical light source mounting surface, and the like. It is.

  1 arm, 2 light source lighting power source, 3 heat sink, 4 light source, 5 reflector, 6 acrylic cover, 7 cover mounting plate, 8 screws, 9 cover mounting frame, 10 lighting fixture, 31 light source mounting surface, 32 opening, 33 Fin, 34 Opening wall part, 35 Edge part, 36 Peripheral wall part, 37 Light source attaching part, 38 Light source attaching upper part, 39 Tip part, 51 Reflecting plate opening, 52 Light source opening, 61 Cover opening, 62 Cover opening edge part, 71 Air hole, 72 Screw hole, 73 Outer peripheral edge part, 74 Center area, 75 Fan-shaped area, 76 Blocking area, 90 Cover part.

Claims (3)

In a luminaire comprising a heat sink that attaches a light source to the lower surface side and dissipates heat emitted from the light source,
In the heat sink, a heat sink through-hole penetrating from below to above is formed,
An illumination apparatus comprising: a cover part formed with a plurality of communication holes communicating with the heat sink through hole, the cover part being attached to the heat sink so as to cover a lower surface side of the heat sink. The cover part is
A light transmissive plate portion having an opening formed in a portion facing the heat sink through hole;
2. The metal plate portion in which the plurality of communication holes are formed, and the metal plate portion is disposed so as to close the opening formed in the light transmissive plate portion. Lighting fixtures. The heat sink is
An opening wall portion in which a peripheral edge of the heat sink through hole protrudes toward the cover portion side,
The metal plate part is
Between the outer peripheral edge portion on the heat sink side and the distal end portion of the opening wall portion, the edge portion of the opening of the light transmissive plate portion is sandwiched and fixed to the distal end portion of the opening wall portion. The lighting fixture according to claim 2.

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