JP2014075209A - Vehicular lighting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular lighting fixture capable of efficiently cooling a light source with a simple configuration without causing increase in size and cost.SOLUTION: In a vehicular lighting fixture (headlamp) 1 in which at least an LED (light source) 2 is housed in a lamp chamber 4 defined by a housing 2 and a lens 3 covering the opening of the housing, a heat sink (first heat dissipation means) 11 and a metallic plate (second heat dissipation means) 12 for dissipating the heat generated by the LED 5 are arranged vertically, and at least the metallic plate 12 and the LED 5 are connected by a heat pipe 13. Here, the heat sink 11 and the metallic plate 12 are arranged inside the lamp chamber 4 or outside the lamp chamber 4. The metallic plate 12 may have a plurality of holes.

Description

  The present invention relates to a vehicular lamp in which two heat dissipating means for dissipating heat generated by a light source accommodated in a lamp chamber are arranged vertically.

  In recent years, LEDs (light-emitting diodes) are being adopted as light sources for vehicle lamps such as headlamps in place of conventional bulbs. The LED has the features of high brightness, long life, and power saving, but has a drawback that most of the input electric power becomes heat and the luminous efficiency and life are reduced by the heat generated by itself. Therefore, in a vehicular lamp using an LED as a light source, how to cool the LED is an important issue.

  Therefore, for example, Patent Document 1 proposes a forced water-cooled vehicle headlamp as shown in FIG.

  That is, FIG. 7 is a side sectional view of the vehicle headlamp proposed in Patent Document 1. In the vehicle headlamp 101 shown in the figure, a housing 102 and a lens 103 covering the front opening are defined. Housed in the lamp chamber 104 are two upper and lower LEDs 105 and 106 and heat receiving jackets 107 and 108 for transmitting heat generated by the LEDs 105 and 106 to the cooling water. A radiator 109 and a fan 110 are disposed on the back side of the housing 102 outside the lamp chamber 104. The radiator 109 and the heat receiving jackets 107 and 108 are connected by a cooling water pipe 111 to form a closed loop of cooling water. A circular circulation path is formed, and a pump 112 and a reservoir tank 113 are provided in this circulation path.

  When the vehicle headlamp 101 configured as described above is turned on, the fan 110 and the pump 112 are driven to circulate the cooling water through the circulation path, and the heat generated by the light emission of the LEDs 105 and 106 is the heat receiving jackets 107 and 108. The cooling water that has been transmitted to the cooling water at the temperature and has been heated to receive the heat is cooled by heat dissipation by heat exchange with the cooling air sent from the fan 110 at the radiator 109, and the cooled cooling water is cooled to the heat receiving jackets 107, The heat generated by the LEDs 105 and 106 is received again, and the LEDs 105 and 106 are forcibly water-cooled by the cooling water by continuously repeating the same operation.

JP 2006-226794 A

  However, in the vehicle headlamp 101 shown in FIG. 7 proposed in Patent Document 1, the LEDs 105 and 106 are effectively cooled by forced water cooling, while the heat receiving jackets 107 and 108 for realizing forced water cooling. , A radiator 109, a fan 110, a cooling water pipe 111, a pump 112, a reserve tank 113, and the like are required, which increases the number of parts, increases the complexity of the structure, and increases the cost. In addition to the increase in size, there is a problem that power consumption increases because the fan 110 and the pump 112 need to be driven.

  The present invention has been made in view of the above problems, and the object of the present invention is to provide a vehicular lamp that can efficiently cool a light source with a simple configuration without causing an increase in size and cost. It is in.

  In order to achieve the above object, according to the first aspect of the present invention, in a vehicular lamp comprising at least a light source housed in a lamp chamber defined by a housing and a lens covering the opening, heat generated by the light source is generated. A first heat radiating means and a second heat radiating means for dissipating heat are arranged above and below, and at least the second heat radiating means and the light source are connected by a heat pipe.

  According to a second aspect of the present invention, in the first aspect of the invention, the first heat radiating means and the second heat radiating means are arranged outside the lamp chamber.

  According to a third aspect of the present invention, in the first aspect of the invention, the first heat radiating means and the second heat radiating means are arranged in the lamp chamber.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the first heat radiating means is a heat sink, and the second heat radiating means is a metal flat plate installed substantially horizontally. It is characterized by comprising.

  According to a fifth aspect of the present invention, in the fourth aspect of the invention, a plurality of holes are formed in the metal flat plate.

  According to the first aspect of the present invention, the heat generated by the light source in the lamp chamber is conducted to the first heat radiating means and the second heat radiating means, and is radiated by the first and second heat radiating means. The light source is cooled and the temperature rise is suppressed, but air is directed toward the first heat radiating means by the convection of the air generated by the heat radiating in the second heat radiating means arranged below the first heat radiating means. Since it flows, the heat radiation performance of the first heat radiation means is enhanced and the light source is more effectively cooled. In this case, since many parts and power consuming devices are not required as in the case of adopting the forced water cooling method as the cooling means, the number of parts is reduced, the cost is reduced, the vehicle lamp is reduced in size, and Power saving can be achieved.

  According to the second aspect of the present invention, since the first heat radiating means and the second heat radiating means are arranged outside the lamp chamber, heat exchange between the first and second heat radiating means with low temperature outside air is promoted. The light source is cooled more effectively and the temperature rise is kept low.

  According to the invention described in claim 3, since the first heat radiating means and the second heat radiating means are arranged in the lamp chamber, the vehicle lamp can be further miniaturized.

  According to the fourth aspect of the present invention, air convection is generated in the vicinity of the metal flat plate by the heat conducted from the light source to the metal flat plate through the heat pipe, and the upward air flow by the air convection is generated in the upper heat sink. In order to improve the heat dissipation performance of the heat sink by flowing toward the heat source, the light source is effectively cooled and the temperature rise is kept low.

  According to the fifth aspect of the present invention, air convection is generated in the vicinity of the metal flat plate, and the air passes through the plurality of holes formed in the metal flat plate to improve the heat dissipation of the metal flat plate. Is more effectively cooled and the temperature rise is kept low.

It is a sectional side view of the vehicle lamp which concerns on Embodiment 1 of this invention. It is the sectional view on the AA line of FIG. (A), (b) is a figure of the arrow B direction of FIG. It is a sectional side view of the vehicle lamp which concerns on Embodiment 2 of this invention. It is a sectional side view of the vehicle lamp which concerns on Embodiment 3 of this invention. It is CC sectional view taken on the line of FIG. It is a sectional side view of the vehicle headlamp proposed in Patent Document 1.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
1 is a side sectional view of a vehicular lamp according to Embodiment 1 of the invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIGS. 3 (a) and 3 (b) are views in the direction of arrow B in FIG. The vehicle lamp 1 according to the present embodiment is a headlamp disposed on the left and right of the front end of the vehicle. Since the basic configuration of the left and right headlamps 1 is the same, only one headlamp 1 will be illustrated and described below.

  As shown in FIG. 1, the headlamp 1 has a light source LED 5, a light source LED 5, and a light chamber 4 defined by a resin housing 2 and a transparent resin lens 3 covering the front opening of the resin housing 2. It includes a reflector 6 that reflects light toward the front of the vehicle (left side in FIG. 1), an aiming mechanism 7 for finely adjusting the light irradiation direction, and the like.

  The LED 5 and the reflector 6 are fixed on a support portion 8b that protrudes horizontally from the middle height position of a vertical main body portion 8a of a rectangular flat plate-shaped holder 8 made of a metal having high thermal conductivity. ing. Then, horizontal aiming bolts 9 and 10 are threadedly inserted into a total of four locations (only two locations at the top and bottom are shown in FIG. 1) of the main body 8a of the holder 8, respectively. The aiming mechanism 7 is constituted by the aiming bolts 9 and 10.

  Thus, in the present embodiment, as shown in FIG. 1, the heat sink 11 constituting the first heat radiating means is fixed to the upper half of the back surface of the housing 2. The rectangular metal flat plate 12 which comprises a 2nd thermal radiation means is arrange | positioned horizontally. The metal flat plate 12 and the LED 5 (more precisely, the support portion 8b of the holder 8) are connected by a heat pipe 13. Here, the heat pipe 13 extends vertically downward from a position where the LED 5 of the support portion 8 b of the holder 8 is fixed, and then is bent at a right angle near the bottom surface of the housing 2 to penetrate the housing 2. The metal flat plate 12 is attached to the end protruding outside the housing 2.

  Although not shown, the heat sink 11 is formed by arranging a plurality of thin rectangular plate-like heat radiation fins that are long in the vertical direction on the back surface of a vertical flat plate-like base plate in the horizontal direction (perpendicular to the plane of FIG. 1) at appropriate intervals. This is integrally formed by aluminum die casting or the like having high thermal conductivity. The metal flat plate 12 is made of a metal such as aluminum or copper having a high thermal conductivity, which is solid as shown in FIG. 3 (a) or shown in FIG. 3 (b). A plurality of such circular holes 14 are used. In addition, it is desirable to perform surface treatment for increasing the emissivity on the surface of the metal flat plate 12, particularly on the upper surface facing the heat sink 11. Moreover, it is desirable to use the heat pipe 13 having a top heat specification that is advantageous for heat conduction from the upper part to the lower part.

  Thus, in the headlamp 1 configured as described above, when the LED 5 that is the light source is energized and the LED 5 emits light, the light is reflected to the front of the vehicle by the reflector 6, and this reflected light is combined with direct light. The light passes through the lens 3 and is irradiated forward of the vehicle. The LED 5 generates heat simultaneously with light emission, and part of this heat is conducted from the holder 8 through the air in the lamp chamber 4 and the housing 2 to the heat sink 11 and from the heat sink 11 to the outside air. Heat is dissipated. The other heat is conducted from the holder 8 through the heat pipe 13 to the metal flat plate 12 and is radiated from the metal flat plate 12 to the outside air. Thus, since the heat generated by the LED 5 is radiated to the outside air by the heat sink 11 and the metal flat plate 12, the LED 5 is cooled and its temperature rise is suppressed to a low level, and the luminous efficiency and life of the LED 5 are reduced. It is prevented.

  Further, in the present embodiment, air convection is generated near the metal flat plate 12 due to heat dissipation, and an updraft due to the air convection flows toward the upper heat sink 11 as indicated by an arrow in FIG. In order to enhance the heat dissipation performance of the heat sink 11, the LED 5 is cooled more effectively, and the temperature rise is suppressed to a low level. In this case, if a plurality of holes 14 are formed in the metal flat plate 12 as shown in FIG. 3B, air passes through the plurality of holes 14 in the metal flat plate 12 by convection generated in the vicinity of the metal flat plate 12. For this reason, the heat dissipation of the metal flat plate 12 is enhanced, whereby the LED 5 is more effectively cooled, and the temperature rise is suppressed low.

  In particular, in the present embodiment, since the heat sink 11 and the metal flat plate 12 are disposed outside the lamp chamber 4, the heat dissipation of the heat sink 11 and the metal flat plate 12 is promoted by heat exchange with the outside air having a low temperature. Is more effectively cooled.

  And in the headlamp 1 which concerns on this Embodiment, since components, such as a fan and a pump which consume many components and electric power like the case where a forced water cooling system is employ | adopted as a cooling means, become unnecessary, the number of parts is reduced. As a result, the cost can be reduced, the headlamp 1 can be reduced in size, and power can be saved. Further, since there is no need to provide moving parts such as a fan and a pump, generation of vibrations and noises can be prevented.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIG.

  FIG. 4 is a side sectional view of a vehicular lamp (headlamp) according to Embodiment 2 of the present invention. In FIG. 4, the same elements as those shown in FIG. The re-explanation about them is omitted.

  The present embodiment is characterized in that, in the headlamp 1 according to the first embodiment, the LED 5 (more precisely, the support portion 8b of the holder 8) and the heat sink 11 are connected by a heat pipe 15. Is the same as that of the first embodiment.

  Thus, in this embodiment, since the LED 5 and the heat sink 11 are also connected by the heat pipe 15, the heat generated by the LED 5 is conducted to the heat sink 11 through the heat pipe 15, so that the amount of heat conduction to the heat sink 11 increases. As a result, the LED 5 can be cooled more effectively. In addition, the same effects as those of the first embodiment can be obtained in the present embodiment.

<Embodiment 3>
Next, a third embodiment of the present invention will be described below with reference to FIGS.

  5 is a side sectional view of a vehicular lamp (headlamp) according to a third embodiment of the present invention, and FIG. 6 is a sectional view taken along the line CC of FIG. 5, which is also shown in FIG. The same elements are denoted by the same reference numerals, and description thereof will be omitted below.

The present embodiment is characterized in that a heat pipe 11 that is a first heat radiating means, a metal flat plate 12 that is a second heat radiating means, and a heat pipe 13 that connects the LED 5 and the metal flat plate 12 are arranged in the lamp chamber 4. The heat sink 11 is fixed in close contact with the back surface of the holder 8. The rest of the configuration is the same as that of the first embodiment. Thus, the same effects as those of the first embodiment can be obtained in this embodiment, but in this embodiment, the heat sink 11 and the metal flat plate are obtained. Since 12 and the heat pipe 13 are arranged in the lamp chamber 4, the effect of further miniaturizing the headlamp 1 can be obtained.

  Also in this embodiment, the LED 5 and the heat sink 11 may be connected by a heat pipe (not shown), and a plurality of holes 14 may be formed in the metal flat plate 12 as shown in FIG. .

  By the way, although the form which applied this invention with respect to the headlamp was demonstrated above, of course, this invention is applicable similarly to arbitrary vehicle lamps other than a headlamp. In the above embodiment, an example in which an LED is used as a light source has been described. However, a vehicular lamp using a light emitting element such as an LD (laser diode), a conventional bulb, or the like as a light source is also applicable to the present invention. Of course, it is included.

1 Headlamp (vehicle lamp)
2 Housing 3 Lens 4 Light chamber 5 LED (Light source)
6 Reflector 7 Aiming mechanism 8 Holder 8a Holder body 8b Holder support 9, 10 Aiming bolt 11 Heat sink (first heat dissipation means)
12 Metal flat plate (second heat dissipation means)
13 Heat pipe 14 Hole 15 Heat pipe

Claims (5)

In a vehicle lamp comprising at least a light source housed in a lamp chamber defined by a housing and a lens that covers the opening,
Vehicle oil characterized in that first heat radiating means and second heat radiating means for radiating heat generated by the light source are arranged above and below, and at least the second heat radiating means and the light source are connected by a heat pipe. Light fixture.   2. The vehicular lamp according to claim 1, wherein the first heat radiating means and the second heat radiating means are arranged outside the lamp chamber.   2. The vehicular lamp according to claim 1, wherein the first heat dissipating means and the second heat dissipating means are disposed in the lamp chamber.   The vehicular lamp according to any one of claims 1 to 3, wherein the first heat dissipating means is constituted by a heat sink, and the second heat dissipating means is constituted by a metal plate installed substantially horizontally. 5. The vehicular lamp according to claim 4, wherein a plurality of holes are formed in the metal flat plate.

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