JP6480117B2 - LED lighting device - Google Patents

Description

  The present invention relates to an LED lighting device having a heat dissipation structure for suppressing a temperature rise associated with light emission.

  In recent years, in place of incandescent bulbs and fluorescent lamps, lighting devices using light emitting diode elements (LEDs) as light sources have come to be used frequently. Such an LED illuminating device includes a light emitting part in which an LED is mounted and sealed on a substrate, and an apparatus main body for housing the light emitting part.

  When such an LED lighting device has a light emission luminance set according to an illumination range or an illumination purpose and becomes a high-luminance type, there are cases where LEDs are used in units of several tens. For this reason, as a result of a large amount of current flowing through the LED, the amount of heat generated by the entire light emitting unit also increases proportionally.

  With respect to the heat generation of the light emitting part, the temperature rise is suppressed by forming the apparatus main body from a material with high heat dissipation or providing a heat radiating part such as a heat sink (Patent Document 1). Moreover, in order to improve the heat dissipation in the said light emission part, there also exists what was comprised so that the temperature rise might be suppressed by applying the wind generated with the fan.

  Patent Document 2 discloses an LED light emitting device in which a cylindrical surface of a heat pipe is used as an LED mounting portion. The heat pipe can dissipate heat generated in the LED mounting portion by being connected to a heat sink.

JP 2008-306084 A JP2013-165182A

  As a heat dissipation structure for suppressing the temperature rise of the light emitting part, it is possible to obtain an effect of improving the heat dissipation efficiency by forcibly sending air from the outside by a fan, but a space for installing the fan is required. The LED lighting device cannot be downsized. In addition, the influence of noise generated when the fan is driven becomes a problem.

  On the other hand, in the heat dissipation structure using the heat pipe, the LED mounting form is limited, and an illumination effect suited to the application cannot be obtained, and the design freedom as a lighting device is limited.

  Accordingly, an object of the present invention is to provide an LED lighting device that can be incorporated in accordance with various apparatus main bodies on which a light emitting unit is mounted and can efficiently absorb and release heat generated in the light emitting unit. It is to be.

In order to solve the above problems, an LED lighting device of the present invention is an LED lighting device including a light-emitting unit and a heat-dissipating unit that releases heat generated from the light-emitting unit. A heat-insulating container having a sealed space, wherein the heat-insulating container radiates the heat transport medium that has absorbed heat generated from the light-emitting unit to the outside and stores the heat-transport medium, and as the distance from the bottom increases. An inner wall surface is provided with a side wall portion inclined inward, the light emitting portion is disposed on the outer wall surface of the bottom portion, and the side wall portion forms an outer surface of the apparatus main body .

  According to the LED lighting device according to the present invention, the heat transport medium enclosed in the heat insulating container is changed from the liquefied state to the vaporized state by the heat generated from the light emitting unit, so that the efficiency of heat absorption and heat dissipation can be increased. . Thereby, the temperature rise of the light emitting part can be kept constant. In addition, since the circulation cycle of liquefaction and vaporization of the heat transport medium is continuously generated in a sealed heat insulating container according to the heat generation amount of the light emitting unit, the temperature management of the light emitting unit can be automated.

It is a perspective view of the LED lighting apparatus of 1st Embodiment. It is sectional drawing of the LED lighting apparatus of 1st Embodiment. It is a perspective view of the LED lighting apparatus of 2nd Embodiment. It is sectional drawing of the LED lighting apparatus of 2nd Embodiment.

  1 and 2 show an LED lighting device 11 according to a first embodiment of the present invention. The LED lighting device 11 is formed in accordance with a conventional light bulb type lighting device, and includes an apparatus main body (heat radiating portion) 12 having an electrical connection portion 19 at one end, and a light emitting portion 13 mounted on the heat radiating portion 12. I have. The heat radiating part 12 has a structure for absorbing and radiating heat generated from the light emitting part 13. Further, the light emitting part 13 is covered with a hood part 17 made of translucent resin or glass. In addition, since the LED lighting apparatus 11 of this embodiment is a downlight type, as shown in FIG. 2, the electrical connection part which consists of a cap member in the connector 26 provided in various lighting fixtures, a ceiling, etc. By mounting 19, the light emitting unit 13 is attached so as to face downward.

  The heat radiating part 12 is formed by a heat insulating container 22 having a sealed space 20 in which a liquid heat transport medium 21 is enclosed. The heat insulating container 22 is formed by a bottom portion 23 on which the light emitting unit 13 is mounted and a cylindrical side wall portion 24. The bottom portion 23 is made of ceramics having high light reflectance, and is curved so as to incline toward the central portion where the light emitting portion 13 is provided. On the other hand, ceramic with high infrared emissivity is used for the side wall 24, and heat generated in the sealed space 20 can be efficiently radiated to the outside. In addition, the side wall part 24 is formed in a corrugated shape, or a fin for heat radiation is separately provided, so that the heat radiation effect can be further enhanced.

  The light emitting unit 13 includes an LED unit 16 that is an assembly of a plurality of light emitting elements (not shown) and a substrate 15 on which the LED unit 16 is mounted. The substrate 15 has an electrode pattern (not shown) on which a plurality of light emitting elements are mounted and wired on a mounting surface 15a on the bottom 23 side. The substrate 15 is formed of the same ceramic as the bottom portion 23, and the surface opposite to the mounting surface 15a on which the LED portion 16 is formed becomes a heat input surface 15b toward the sealed space 20 of the heat insulating container 22. ing. In the present embodiment, the substrate 15 is formed integrally with the bottom 23 of the heat insulating container 22, but the substrate 15 may be fixed to the outer wall surface of the bottom 23.

  The heat transport medium 21 uses water, pure water, or the like that is liquid at normal temperature, and is sealed so as to accumulate in the bottom 23 centering on the light emitting section 13 as shown in FIG. The heat transport medium 21 is in a liquid state in a room temperature state where the LED unit 16 is not lit, but when the LED unit 16 is lit and reaches a predetermined temperature or higher, the heat transport medium 21 absorbs this heat and gradually becomes a gas (vapor). Become.

  In the heat insulating container 22, a power supply unit 27 is disposed on the electrical connection unit 19 side, and a wiring cable 28 is laid from the power supply unit 27 toward the substrate 15 of the light emitting unit 13. The wiring cable 28 is electrically connected to the power supply unit 27 and the electrode pattern formed on the substrate 15 through the tube 29.

  The power supply unit 27 contains an IC, a capacitor, and the like for driving the LED unit 16 to emit light. In order to protect these components from the temperature and moisture in the heat insulating container 22, heat insulation and moisture resistance are provided. It is sealed with the protective member 30 provided. Further, the tube 29 is also covered with the protective member 30 having heat insulation and moisture resistance, so that the deterioration or disconnection of the wiring cable 28 can be prevented.

  Next, the heat absorption and heat dissipation actions in the LED lighting device 11 shown in FIGS. 1 and 2 will be described. As described above, since the LED lighting device 11 is a downlight type, the heat transport medium 21 remains in a liquid state at the bottom 23 of the heat insulating container 22 before use (light emission). When electricity is supplied to the LED illumination device 11 in this state, heat is gradually generated with the light emission of the LED unit 16, and this heat is conducted to the substrate 15. Then, the heat conducted to the substrate 15 is absorbed by the liquid heat transport medium 21, and when it reaches a predetermined temperature, it gradually becomes steam and diffuses in the sealed space 20.

  The steam generated in the heat insulating container 22 is dissipated by radiating heat to the outside through the side wall 24, and the cooled steam becomes liquid again and flows back to the bottom 23 of the heat insulating container 22. The cycle between the liquefied state and the vaporized state of the heat transport medium 21 continues while the LED unit 16 emits light. In this way, by repeating the cycle in which the heat transport medium 21 transitions from liquid to vapor in the heat insulating container 22, the heat generated in the LED unit 16 can be constantly suppressed to a constant temperature range, and a stable light emission state Can be maintained. In the present embodiment, since the bottom portion 23 is inclined toward the light emitting portion 13, the heat transport medium 21 that has exchanged heat in the sealed space 20 can be naturally recovered to the bottom portion 23 side.

  In the heat insulating container 22 of the present embodiment, the inside of the bottom 23 and the side wall 24 is a flat surface. By forming a plurality of streak-shaped grooves (not shown) here, the heat transport is performed. Circulation of the medium 21 can be made smooth. In the case of providing the groove portion, it is preferable that the groove portion is formed radially or spirally from the bottom portion 23 toward the side wall portion 24 with the substrate 15 of the light emitter 13 serving as a reservoir portion of the heat transport medium 21 as a center. By forming a plurality of such streak-like groove portions, a capillary phenomenon occurs in the sealed heat insulating container 22, the flow of the heat transport medium 21 becomes smooth, and heat generated from the light emitting portion 13 is evenly absorbed without unevenness. Can do. Furthermore, by moving the heat transport medium along the groove portion, the temperature in the heat insulating container 22 can be quickly radiated to the outside, and an efficient heat radiation effect can be obtained.

  3 and 4 show the LED illumination device 41 of the second embodiment. The LED lighting device 41 includes a first sealed space 45 in which a heat insulating container 42 constituting the heat radiating unit 12 of the LED lighting device 11 according to the first embodiment includes a circular bottom portion 43 and a cylindrical side wall portion 44; The center part of the bottom part 43 has the 2nd sealed space 46 which consists of the protrusion part 50 which protruded cylindrically. Since this LED illumination device 41 is also a downlight type, the light emitting unit 13 is set downward.

  The protruding portion 50 is integrally formed of the same ceramic as the bottom portion 43, and the tip portion is a light emitting portion 47. In addition, the first sealed space 45 and the second sealed space 46 are integrated and sealed.

  The light emitting portion 47 is formed by an LED portion 49 that is an assembly of a plurality of light emitting elements, and a substrate 48 on which the LED portion 49 is mounted. The substrate 48 forms a tip surface of the protrusion 50 with ceramics. It is also possible to form up to the tip end surface of the protruding portion 50 from a single piece of ceramic and to fix the substrate 48 separately. As described above, by providing the protruding portion 50, the LED portion 49 can be set at a position close to the top of the hood portion 17. Further, since the bottom of the second sealed space 46 is the back surface of the substrate 48, the liquid heat transport medium 21 is intensively retained on the back surface side of the substrate 48 that generates the largest amount of heat. And the endothermic effect can be further enhanced. Also in this embodiment, since the bottom 43 of the heat insulating container 42 has a curved shape that inclines toward the protrusion 50, the heat transport medium can be naturally refluxed into the protrusion 50.

  Next, the heat absorption and heat dissipation action in the present embodiment will be described with reference to FIG. When the LED portion 49 is caused to emit light, the liquid heat transport medium 21 accumulated in the protruding portion 50 is heated by the heat accompanying the light emission, and gradually becomes steam while absorbing the heat. The steam flows from the second sealed space 46 into the first sealed space 45 and is radiated by the side wall 44. By repeating such a cycle, the temperature rise of the light emitting unit 47 that continuously emits light can be effectively suppressed.

  In the above embodiment, the light emitting portion 47 is provided at the bottom of the protruding portion 50. However, the outer peripheral surface of the protruding portion 50 can be used as the mounting surface of the light emitting element. As a result, it is possible to illuminate all directions, and the heat transport medium 21 that fills the inside of the protrusion 50 absorbs heat generated from the bottom portion and the outer peripheral surface, and the side wall portion of the first sealed space 46 is absorbed. The heat can be efficiently radiated by 44. The light emitting unit 47 is driven to emit light by a current supplied from the power supply unit 27 provided in the first sealed space 45 through the tube 29 and the wiring cable 28 provided along the outer peripheral surface of the protruding portion 50. . The power supply unit 27 and the tube 29 provided in the first sealed space 45 are sealed by a protection member 30 having moisture resistance and heat insulation.

  In addition, a plurality of streak-like grooves (not shown) are formed from the inner wall surface of the protruding portion 50 to the inner wall surfaces of the bottom portion 43 and the side wall portion 44, so that the heat transport medium heated by the light emitting portion 47 is second. While being easily vaporized and diffused from the sealed space 46 to the first sealed space 45, it becomes liquid and easily recirculates to the bottom of the protrusion 50.

  In the said embodiment, although the lamp-type heat radiating part was formed as a heat insulating container having a sealed space, by changing the shape of this heat insulating container, the LED lighting device having a straight tube type heat radiating part such as a fluorescent lamp can be used. It can also be applied to.

  As described above, in the LED lighting device according to the present invention, the light emitting unit composed of the light emitting element constitutes a part of the heat insulating container in which the heat transport medium is enclosed, or is arranged so as to be in contact with the heat insulating container. Therefore, it is possible to efficiently absorb the heat generated from the light emitting part by the heat transport medium that moves in the heat insulating container and suppress the temperature rise. In addition, the shape and arrangement configuration of the heat insulating container can be set according to the form of the heat insulating part and the light emitting part provided in the main body of the device, ensuring a degree of freedom in design to suit various lighting applications. However, an LED lighting device with high heat dissipation efficiency can be provided.

DESCRIPTION OF SYMBOLS 11 LED illuminating device 12 Heat radiation part 13 Light emission part 15 Board | substrate 15a Mounting surface 15b Heat radiation surface 16 LED part 17 Hood part 19 Electrical connection part 20 Sealed space 21 Heat transport medium 22 Heat insulation container 23 Bottom part 24 Side wall part 26 Connector 27 Power supply part 28 Wiring Cable 29 Tube 30 Protective member 41 LED lighting device 42 Thermal insulation container 43 Bottom 44 Side wall 45 First sealed space 46 Second sealed space 47 Light emitting unit 48 Substrate 49 LED unit 50 Projection

Claims (4)

In the LED lighting device including the light emitting unit and the heat radiating unit that emits heat emitted from the light emitting unit,
The heat radiating portion includes a heat insulating container having a sealed space in which a heat transport medium is enclosed,
The heat insulating container includes a bottom portion for storing the heat transport medium, and a side wall portion that radiates the heat transport medium that has absorbed heat generated from the light emitting portion to the outside, and an inner wall surface is inclined inward as the distance from the bottom portion increases. Prepared,
The LED lighting device , wherein the light emitting portion is disposed on an outer wall surface of the bottom portion, and the side wall portion forms an outer surface of the device main body . 2. The LED lighting device according to claim 1 , wherein the inner wall surface of the side wall portion of the heat insulating container is formed with a plurality of streak-like groove portions for refluxing the vaporized heat transport medium from the side wall portion to the bottom portion by capillary action. It said bottom of the insulated container is adapted to have a cylindrical projecting portion for storing the heat transport medium in the center portion, LED lighting device according to claim 1 which is inclined toward the central portion. The LED lighting device according to claim 1 , wherein the heat insulating container is made of ceramics.

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