JP2008047383A - Lighting tool for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting tool for a vehicle which can control efficiently temperature rise of each of semiconductor light sources. <P>SOLUTION: In the headlight 100 provided with an LED 1, a heat sink part 2 for mounting the LED is composed of a heat pipe part 21 in which working fluid is enclosed, a housing part 23 to contact the LED and to house the heat pipe part and a heat radiating fin part 22 to be connected with the housing part. The heat pipe part is formed in an approximate L shape with a bottom side part 211 close to the LED and a perpendicular part 212 crossing at almost right angles to the bottom side part, and there is formed the heat radiating fin part close to the perpendicular part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicular lamp such as a headlamp, a fog lamp, and a tail lamp mounted on an automobile.

  In recent years, a technique for applying a high-luminance white light-emitting diode to a headlamp has been developed, and Patent Document 1 and the like have been published.

  On the other hand, light-emitting diodes with increased brightness generate a large amount of heat, and unless the temperature raised due to the heat generation is appropriately reduced, the light source luminous flux decreases or the emission color changes to function properly as a headlamp. There is a risk that it will not.

Therefore, in the vehicle headlamp of Patent Document 1, a common metal support member is attached as a heat dissipating member to the lamp units arranged in three stages of upper, middle, and lower for the low beam and the high beam. The temperature of the light emitting diode is lowered by heat dissipation.
JP 2004-31224 A

  However, since the vehicle headlamp described in Patent Document 1 described above dissipates heat by a heat dissipating member common to a plurality of lamp units, the heat of the adjacent lamp unit is transmitted by heat conduction, and the arrangement of the light emitting diodes Depending on the position, there is a possibility that it cannot be cooled sufficiently.

  In addition, the heat dissipation performance of the massive heat dissipation member increases as the volume increases, but if the volume exceeds a predetermined volume, it becomes saturated and the heat dissipation performance per volume decreases, so use a large heat dissipation member. However, the expected heat dissipation effect may not be obtained.

  Therefore, an object of the present invention is to provide a vehicular lamp that can efficiently suppress the temperature rise of each semiconductor-type light source.

  In order to achieve the above object, a vehicle lamp of the present invention is a vehicle lamp provided with a semiconductor-type light source, and a heat pipe portion to which the semiconductor-type light source is attached includes a heat pipe portion in which a working fluid is sealed, and The semiconductor-type light source is brought into contact with the housing portion and the heat pipe portion is housed, and a heat radiating fin portion connected to the housing portion.

  Here, the heat pipe part is formed in a substantially L shape by a base part close to the semiconductor light source and a vertical part substantially orthogonal to the base part, and the heat radiating fin part is formed close to the vertical part. It is preferable that it is the structure which is made.

  In the vehicular lamp of the present invention configured as described above, a heat sink is attached to each semiconductor-type light source that generates heat when light is output, and a heat fluid in which a working fluid is sealed in the accommodating portion of the heat sink. The pipe part is accommodated. The housing portion is provided with a radiating fin portion.

  That is, the heat generated in the semiconductor-type light source is input into the heat pipe part through the housing part, and is transported in a direction away from the heat source and radiated into the air from the radiation fin part connected to the housing part. The temperature rise of each semiconductor-type light source can be efficiently suppressed.

  In addition, by forming the heat pipe part in a substantially L shape and dissipating the heat input at the bottom part in the vertical part, heat transport is promoted and heat dissipation performance can be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 2 is a diagram showing a schematic configuration of the headlamp 100 as a vehicular lamp according to the present embodiment, and is a front view of the left headlamp 100 toward the vehicle.

  First, in terms of the overall configuration, the headlamp 100 according to the present embodiment covers the upper unit 100a, the middle unit 100b, the lower unit 100c, and the front side thereof, which are configured from a plurality of light source units. It is mainly composed of a transparent translucent cover 6.

  The upper unit 100a and the middle unit 100b are arranged for a low beam, and the lower unit 100c is arranged for a high beam.

  The middle unit 100b is provided with a swivel mechanism 5 that performs light distribution control in the vehicle width direction.

  FIG. 1 shows a cross section in the vehicle front-rear direction (cross section along line AA in FIG. 2) of the plurality of light source units 10,... Constituting the middle unit 100b.

  The light source unit 10 includes an LED 1 as a semiconductor-type light source, a reflector 3 that accommodates the LED 1 in a rear bottom surface, a convex lens 4 that is disposed in a front opening of the reflector 3, and a heat sink portion 2 that performs heat dissipation of the LED 1. Consists mainly of.

  The LED 1 is a white light-emitting diode having a light-emitting chip, and heat is generated because an energization current increases in order to output high-luminance light. When the temperature of the LED 1 rises due to this heat generation, the luminance decreases or the emission color changes. Therefore, in order to suppress the temperature rise, the heat sink portions 2 described later are individually provided.

  The LED 1 is disposed on the lower surface opening 3 a of the reflector 3 in a state where the LED 1 is installed on the substrate 11 having thermal conductivity.

  That is, the reflector 3 is provided with the LED 1 in the vicinity of the first focal point of the reflection surface formed as a spheroid curved surface or a free curved surface based on the spheroid, with the light emitting part facing each other, and the lower surface opening. The light generated from the LED 1 installed in the part 3a is reflected by the reflecting surface and irradiated on the back surface of the convex lens 4 on the vehicle front side.

  The light incident from the back surface of the convex lens 4 is emitted toward the front of the vehicle, and the light passing through the translucent cover 6 illuminates the outside.

  On the other hand, on the substrate 11 of the LED 1, a heat sink 2 for heat dissipation is individually attached for each LED 1 as shown in FIG. 3 in order to suppress the temperature rise of the LED 1.

  This heat sink part 2 is mainly comprised from the tubular heat pipe part 21, the box-shaped accommodating part 23 which accommodates it, and the radiation fin part 22. As shown in FIG.

  As shown in FIG. 1, the heat pipe portion 21 is formed in a substantially L shape by a bottom portion 211 and a vertical portion 212 that extends substantially perpendicular to the bottom portion 211 and extends upward.

  The inside of the heat pipe portion 21 is decompressed and filled with a working fluid, and efficiently carries out heat transport by the heat transfer law when the working fluid expands and contracts.

  For example, by arranging a wick having a capillary structure along the inner periphery of the heat pipe portion 21, the working fluid evaporates due to heat input from the heating surface 21b to which the LED 1 is adjacent, and the LED 1 is absorbed in the latent heat. It moves in the direction of the non-heating surface 21a away from the center.

  Then, heat is radiated from the tube wall on the non-heated surface 21a, which is a low temperature portion, and the working fluid condensed into a liquid by releasing latent heat here again moves toward the heated surface 21b. Thus, if heat transport is efficiently performed through the heat pipe part 21, the generated heat can be kept away from the LED1.

  The structure of the heat pipe portion 21 may be other than that described above. For example, if a thermosiphon heat pipe using gravity is used, the capillary phenomenon is not used, so the wick is arranged in the pipe. There is no need to do.

  Moreover, water, acetone, ammonia, methanol, mercury, sodium, Freon, etc. can be used for the working fluid sealed in this heat pipe part 21. FIG.

  Further, a plurality of the heat pipe portions 21 are arranged at intervals in the vehicle width direction as shown in FIG. 3 in order to efficiently perform heat transport.

  The accommodating portion 23 accommodates the bottom portion 211 of the heat pipe portion 21 inside, and the attachment portion 231 for fixing the LED 11 by contacting the substrate 11 and the vertical portion 212 of the heat pipe portion 211 inside. The heat radiation part 232 is mainly comprised.

  A plurality of heat pipe portions 21,... Are accommodated in the housing portion 23, a partition plate (not shown) is installed between the heat pipe portions 21, 21, and a lower opening portion of the mounting portion 231 is The lid portion 233 is closed.

  Further, the inner wall surface of the heat radiating portion 232 is brought into contact with the side surface in the vehicle front-rear direction of the vertical portion 212 of the heat pipe portion 21 so that the heat conduction efficiency is improved.

  And the radiation fin part 22 is attached to the wall of this heat radiation part 232 at the vehicle rear side. The heat radiating fin portion 22 may be made of a copper, copper alloy, or other surface that is excellent in heat dissipation and subjected to corrosion prevention treatment.

  This heat radiating fin portion 22 is formed by a plurality of projecting plates 221,... Extending rearward of the vehicle connected orthogonally to the heat radiating portion 232 that extends in the vehicle width direction.

  Thus, since the non-heated surface 21a of the heat pipe portion 21 is cooled earlier than other portions by the heat radiation by the heat radiating fin portion 22, the temperature difference with the heated surface 21b of the heat pipe portion 21 is increased to increase the efficiency of heat transport. Can be raised.

  In the headlamp 100 of this embodiment configured as described above, the heat sink portion 2 is attached to each LED 1 that generates heat when outputting light, and the working fluid is enclosed in the housing portion 23 of the heat sink portion 2. The heat pipe portion 21 is accommodated.

  And the radiation fin part 22 is connected to this accommodating part 23. FIG.

  That is, the heat generated in the LED 1 is input to the heat pipe portion 21 through the housing portion 23, transported in a direction away from the heat source, and radiated into the air from the radiation fin portion 22 connected to the housing portion 23. Therefore, the temperature rise of each LED 1 can be efficiently suppressed.

  As described above, if heat is transported by the heat pipe portion 21 and then radiated by the heat radiating fin portion 22, heat saturation hardly occurs in the heat radiating fin portion 22, and efficiency is improved even if the amount of heat generated by the LED 1 increases. Heat can be released.

  Further, when the heat pipe portion 21 is formed in a substantially L shape and heat is input at the bottom portion 211, the working fluid whose density has been reduced by evaporation is smoothly directed toward the upper end of the vertical portion 212 above the bottom portion 211. Flows out.

  Then, the working fluid is cooled by conducting heat from the vertical portion 212 that tends to be the low temperature portion at the farthest position from the LED 1 to the radiating fin portion 22, is cooled down, returns to the bottom portion 211 again.

  In this way, if the L-shaped heat pipe portion 21 is erected with the vertical portion 212 facing upward, it is easy to dissipate heat in the vertical portion 212, and heat can be efficiently transported.

  Moreover, the heat sink part 2 can be reduced in size by bend | folding the heat pipe part 21 in L shape. Furthermore, since the vertical portion 212 of the heat pipe portion 21 is accommodated on the vehicle rear side of the reflector 3, an arrangement space can be easily secured.

  In addition, by using the heat radiation fin portion 22 with a moderate gap formed instead of the bulky heat sink, the weight can be reduced, and the light distribution control can be performed by the swivel mechanism 5 even with a small driving force. .

  Although the best embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are possible. Are included in the present invention.

  For example, in the above-described embodiment, the case where the present invention is applied to the headlamp 100 as a vehicle lamp has been described. However, the present invention is not limited to this, and the present invention may be applied to a vehicle lamp such as a fog lamp and a tail lamp. .

  Furthermore, although LED1 was demonstrated as a semiconductor type light source in the said embodiment, it is not limited to this, It is a semiconductor type light source and semiconductor laser (LD) using organic semiconductors, such as organic EL (electroluminescence). May be.

  Moreover, although the substantially L-shaped heat pipe part 21 was demonstrated in the said embodiment, it is not limited to this, For example, the non-heating surface 21a which becomes a low-temperature part diagonally from the base part 211 like a square shape, for example May be extended, or a linear heat pipe without a bent portion may be used.

It is sectional drawing explaining the structure of the light source unit arrange | positioned at the headlamp of the best embodiment of this invention. It is a front view explaining schematic structure of the headlamp of the best embodiment of this invention. It is a perspective view explaining the structure of a heat sink part.

Explanation of symbols

100 Headlamp (vehicle lamp)
1 LED (semiconductor light source)
2 heat sink part 21 heat pipe part 211 bottom side part 212 vertical part 22 radiation fin part 23 accommodation part

Claims (2)

A vehicle lamp equipped with a semiconductor-type light source,
The heat sink part to which the semiconductor type light source is attached includes a heat pipe part in which a working fluid is sealed, an accommodating part that contacts the semiconductor type light source and accommodates the heat pipe part, and a radiating fin connected to the accommodating part The vehicle lamp characterized by having a part.   The heat pipe portion is formed in a substantially L shape by a bottom portion close to the semiconductor light source and a vertical portion substantially orthogonal to the bottom portion, and the heat radiating fin portion is formed close to the vertical portion. The vehicular lamp according to claim 1.

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