JP2008123756A - Vehicular lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular lighting fixture using an LED as an light source, capable of suppressing increase of the LED's temperature by improving the radiation performance of the self-exothermic LED while maintaining the miniaturization, the weight saving, and the reliability, thereby suppressing decrease of the luminous efficiency of the LED to thereby ensure a predetermined amount of irradiated light and to make the manufacturing cost inexpensive. <P>SOLUTION: In this vehicular lighting fixture, the LED 6 and an optical system controlling an optical path of light emitted from the LED 6 are housed in a lamp chamber 4 constituted by a front lens 4 and a housing 3 provided integrally with a fan duct 16, and radiating fins 13 for radiating heat emitted from the LED are disposed outside the lamp chamber 4. The radiating fins 13 are cooled by open air taken in through an open air intake port 14 of the fan duct 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp using a semiconductor light emitting element as a light source.

  A semiconductor light emitting element, for example, an LED has a characteristic that the light emission efficiency decreases with an increase in temperature. Possible causes of LED temperature rise include self-heating during lighting and exposure to a high temperature environment.

  On the other hand, LEDs generally have advantages such as small size, low power consumption, and long life compared to various lamps. Conventionally, LEDs have been used to make high-mount stop lamps, stop-and-tail lamps, turn signals, etc. In recent years, a vehicle headlamp using an LED as a light source has been proposed.

  In general, a vehicular lamp has a lamp chamber formed by a front lens and a housing, and an LED serving as a light source is supported in the lamp chamber. When the LED is turned on, the temperature of the LED itself rises due to the self-heating of the LED, and as a result, the light emission efficiency of the LED decreases and the amount of irradiation light of the lamp decreases, and in the extreme case due to the deterioration of the light distribution performance There is also a possibility that the light distribution standard required for the lamp will not be satisfied.

  Therefore, proposals have been made for vehicle headlamps that prevent the occurrence of the above problems. As shown in FIG. 8, the vehicle head includes a transparent cover 51, a lamp body 52, a support bracket 56 in which the vertical panel portion 53, the unit support portion 54 and the heat sink portion 55 are integrated, and a socket cover 57. A lamp chamber 58 of the lamp 50 is formed, and the vertical panel portion 53 and the unit support portion 54 of the support bracket 56 are located in the lamp chamber 58 of the headlamp 50, and the heat sink portion 55 is a lamp chamber 58 of the headlamp 50. It extends outside.

  A semiconductor light emitting element 59, a reflector 60, and a light control member 61 are fixed to the unit support portion 54 of the support bracket 56 located in the lamp chamber 58 of the headlamp 50. The light control member 61 includes a projection lens 62. I support it.

  In the vehicle headlamp 50 having the above-described configuration using the semiconductor light emitting element 59 as a light source, self-heating when the semiconductor light emitting element 59 is turned on is a unit support portion 54 of a support bracket 56 formed of a material that is a good heat conductor. Then, the heat is transferred from the heat sink portion 55 to the heat sink portion 55, and is dissipated outside the lamp chamber 58 by the heat sink portion 55. Thereby, the temperature rise of the semiconductor light emitting element 59 itself when the semiconductor light emitting element 59 is turned on is suppressed (see, for example, Patent Document 1).

In addition, air is blown to the metal board on which the LED is mounted using a fan, and the metal board is actively cooled to increase the heat dissipation of the metal board, thereby reliably suppressing the temperature rise of the LED itself when the LED is lit. The thing which made it do is proposed (for example, refer patent document 2).
JP-A-2005-141917 JP 2004-214144 A

  In the conventional vehicle headlamp 50 described in the above “Patent Document 1”, most of the heat generated in the semiconductor light emitting element 59 is the unit support portion 54 of the support bracket 56 on which the semiconductor light emitting element 59 is mounted. To the heat sink portion 55, and is dissipated outside the lamp chamber 58 by the heat sink portion 55.

  By the way, the heat sink portion 55 has a higher heat dissipation efficiency and a better heat dissipation effect as the heat dissipation area of the entire surface of the heat sink portion 55 in contact with the outside air (air) is larger. In other words, the size of the heat sink portion 55 is related to the heat dissipation efficiency. However, when the heat sink portion 55 is increased, the entire vehicle headlamp 50 is increased and the weight is also increased. For this reason, it is conceivable that the degree of freedom in designing the dimensions of the heat sink portion 50 cannot be ensured due to the mounting space and weight restrictions of the vehicle headlamp 50, and sufficient heat dissipation efficiency cannot be obtained.

  In the conventional vehicle headlamp described in the above-mentioned “Patent Document 2”, the heat dissipation of the metal substrate on which the LED is mounted is reliably improved by performing forced air cooling. In addition, the motor for driving the fins and the like increase the weight of the vehicle, and the installation space for the blower means also hinders the downsizing.

  Further, the provision of the air blowing means increases the manufacturing cost, and there is a possibility that a failure may occur in a mechanical device such as a motor.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to dissipate heat of self-heating of an LED while maintaining small size, light weight, and reliability in a vehicle lamp using an LED as a light source. The present invention provides a vehicular lamp that suppresses a rise in temperature of the LED by increasing the property, thereby suppressing a decrease in the light emission efficiency of the LED, can secure a predetermined amount of irradiation light, and has a low manufacturing cost. is there.

  In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention is characterized in that at least one semiconductor light emitting element is provided in a lamp chamber constituted by a housing in which at least a front lens and a blower duct are integrally provided. And an optical system for controlling the optical path of the light emitted from the semiconductor light emitting element, and a vehicle lamp in which heat dissipating fins for dissipating heat generated in the semiconductor light emitting element are disposed outside the lamp chamber. The air duct is located outside the lamp chamber, and the radiating fin is cooled by outside air sucked from at least one outside air inlet of the air duct.

  The invention described in claim 2 of the present invention is characterized in that, in claim 1, the outside air intake port of the air duct is directed substantially in the irradiation direction of the vehicular lamp.

  The invention described in claim 3 of the present invention is the vehicle lamp according to any one of claims 1 and 2, wherein the vehicular lamp is blown into the traveling wind intake opening opened in front of a front cowl of a motorcycle. It is attached to the front cowl of the motorcycle in a state where the outside air inlet of the duct is in communication.

  The vehicular lamp according to the present invention has heat radiation fins that dissipate heat from a semiconductor light emitting element serving as a light source outside the lamp chamber, and the outside air sucked into a blower duct that is integrally provided in a housing constituting the lamp chamber. The cooling fins were cooled by

  In particular, when mounted on a vehicle, the radiating fins are cooled by forced air cooling by running wind taken into the air duct.

  As a result, the heat dissipation efficiency of the heat dissipation fins is increased and the temperature rise of the LED is greatly suppressed, and the decrease in the light emission efficiency of the LED light source is greatly reduced, and a predetermined amount of irradiation light can be secured.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 7 (the same parts are given the same reference numerals). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  FIG. 1 is a cross-sectional view showing an embodiment of a vehicular lamp according to the present invention. In the vehicular lamp 1, a lamp chamber 4 is formed by a front lens 2 and a housing 3, and a lamp unit 5 is supported in the lamp chamber 4.

  The lamp unit 5 includes an optical system and a heat dissipation system. The optical system is connected to the mount plate 8 on which the LED 6 which is a semiconductor light emitting element serving as a light source, the LED mounting substrate 7 on which the LED 6 is mounted is placed, and the mount plate 8. The projector 9 includes a reflector 9, a lens holder 10 connected to the reflector 9, a shield 11 extending upward from the inner bottom surface of the lens holder 10, and a projection lens 12 supported by the lens holder 10, thereby forming a projector lamp.

  On the other hand, the heat dissipation system includes a mount plate 8 on which the LED mounting substrate 7 on which the LED 6 is mounted is placed, a heat dissipating fin 13 integrated with the mount plate 8 and positioned outside the lamp chamber 4, and one opening (outside air removal). The inlet 14) is directed to the heat radiating fin 13, and the other opening (outside air discharge port 15) is constituted by a blower duct 16 directed in the irradiation direction of the vehicular lamp 1.

  In this case, the lamp unit 5 is fixed to the housing 3 through the radiation fins 13, and the air duct 16 is disposed along the housing 3 integrally with the housing 3.

  Next, the state of light in the optical system and the state of heat in the heat dissipation system will be described.

  First, in the optical system, as shown in FIG. 2, when the LED 6 is turned on and emits light, the light directed from the LED 6 toward the reflector 9 is reflected by the reflector 9 toward the front projection lens 12, and a part thereof is shielded. The optical path is blocked by the body 11. On the other hand, of the light reflected by the reflector 9, the light that is not blocked by the shield 11 is guided through the lens holder 10 to reach the projection lens 12, and is controlled to a desired light distribution by the projection lens 12 to be in front. The light is irradiated in front of the vehicular lamp 1 through the lens 2.

  Next, in the heat dissipation system, as shown in FIG. 3, when the LED 6 is turned on, the LED 6 emits light and also generates heat. The heat (self-heating) generated in the LED 6 moves to the LED mounting board 7 on which the LED 6 is mounted, and is conducted through the LED mounting board 7 and moves to the mount plate 8 on which the LED mounting board 7 is placed. The heat transferred to the mount plate 8 is conducted through the mount plate 8 and moves to the radiation fins 13 integrated with the mount plate 8.

  The heat transferred to the radiating fin 13 is conducted through the radiating fin 13 to reach the surface of the radiating fin 13, and the heat reaching the surface of the radiating fin 13 is transferred to the air in the vicinity of the surface and moves. Is diffused out of the radiating fins 13 as a medium.

  At this time, outside air taken in from the outside air inlet (not shown) facing the irradiation direction of the vehicular lamp 1 is guided through the air duct 16 to the outside air outlet 15 facing the radiation fin 13, and the radiation fin The air is blown toward 13.

  Therefore, the heat generated by the LED 6, reaching the surface of the heat radiating fin 13, and transferred to the air near the surface of the heat radiating fin 13 is forcibly removed by the outside air from the blower duct 16. Heat from the radiation fins 13 is sequentially supplied to the air in the vicinity of the surface of the radiation fins 13, and the amount of heat radiation from the radiation fins 13 increases.

  4 to 7 are views when the vehicular lamp (two-lamp type) having the above-described configuration is mounted on a motorcycle. FIGS. 4 and 5 show the air duct 16 extending along the lower side of the housing 3. FIG. 6 and FIG. 7 show the motorcycle to which the vehicle lamp 1 having the air duct 16 arranged so as to extend along the lateral side of the housing 3 is attached. . 4 is a front view, FIG. 5 is an AA sectional view of FIG. 4, FIG. 6 is a front view, and FIG. 7 is a BB sectional view of FIG.

  In the motorcycle shown in FIGS. 4 and 5, one traveling wind inlet 18 is provided in the cowl 17 below the vehicular lamp 1 attached to the front cowl 17 on the vehicle body side. An outside air discharge port 15 of the air duct 16 extending from the communicated outside air inlet 14 along the lower side and the rear side of the vehicular lamp 1 is located in the vicinity of the radiation fin 13.

  When the LED 6 is lit while the motorcycle is stopped, the heat generated by the LED 6 and reaching the surface of the heat radiating fin 13 is transferred to the air in the vicinity of the surface of the heat radiating fin 13 to generate a rising air current. Then, the air is separated from the heat radiating fins 13, and outside air sucked from the running air intake 18 of the cowl 17 through the external air intake 14 of the air duct 16 is supplied through the air duct 16 near the surface of the heat radiating fin 13. Accordingly, in this case, heat is dissipated from the radiation fins 13 by the thermal convection of air.

  On the other hand, when the LED 6 is lit while the motorcycle is traveling, the outside air (traveling wind) having an air volume corresponding to the traveling speed of the motorcycle is taken in from the traveling wind intake 18 of the cowl 17 and passed through the air duct 16. It is forcibly supplied to the vicinity of the surface of the heat dissipating fins 13 one after another. Therefore, in this case, heat is forcibly dissipated from the heat radiation fins 13 by forced air cooling by the traveling wind.

  In the motorcycle shown in FIGS. 6 and 7, two traveling wind intakes 18 are provided in the cowls 17 on both sides of the vehicular lamp 1 attached to the front cowl 17 on the vehicle body side. An outside air discharge port 15 of the air duct 16 extending along the lateral side and the rear side of the vehicular lamp 1 from the outside air inlet 14 communicated with 18 is located in the vicinity of the radiation fin 13.

  Similarly to the case where one traveling wind inlet 18 is provided in the cowl 17 described above, when the LED 6 is lit while the motorcycle is stopped, the LED 6 is generated and reaches the surface of the radiating fin 13. The heat transferred to the air in the vicinity of the surface of the radiating fin 13 is moved away from the radiating fin 13 by generating an ascending current, and the outside of the air duct 16 is removed from the running wind inlet 18 of the cowl 17 near the surface of the radiating fin 13. Outside air sucked through the inlet 14 is supplied through the air duct 16. Accordingly, in this case, heat is dissipated from the radiation fins 13 by the thermal convection of air.

  On the other hand, when the LED 6 is lit while the motorcycle is running, the outside air (running wind) having the air volume corresponding to the running speed of the motorcycle is taken in from the running wind intake 18 of the cowl 17 in the same manner as described above. It is forcibly supplied sequentially near the surface of the radiating fin 13 through the duct 16. Therefore, in this case, heat is forcibly dissipated from the heat radiation fins 13 by forced air cooling by the traveling wind.

  Note that the two air ducts 16 extending along the lateral and rear sides of the vehicle lamp 1 from both sides of the vehicle lamp 1 may or may not be connected on the rear side, but at least the air duct. It is necessary to provide an opening 19 above the rear side of 16. The air heated by the heat radiating fins 13 is released to the outside of the air duct 16 through the openings 19.

  When there are two outside air intakes 14, the airflow of the traveling air taken into the air duct 16 is doubled as compared with the case where there is one, and the cooling effect of forced air cooling is enhanced accordingly. Therefore, particularly in a vehicular lamp having a large calorific value such as a plurality of lamp units 5 housed in the lamp chamber 4, an excellent effect is exhibited.

  The reflector 9 can also be formed of a material having high thermal conductivity, for example, any metal material among Al, Al alloy, Cu, and Cu alloy. Furthermore, it is possible to form a heat sink on the reflector 9 with a material having high thermal conductivity, for example, any one of Al, Al alloy, Cu, and Cu alloy.

  It is also possible to provide a heat sink on the mount plate 8 on which the LED mounting substrate 7 is placed with a material having high thermal conductivity, for example, any one of Al, Al alloy, Cu, and Cu alloy. .

  In this way, it is possible to further improve the cooling efficiency by forming the constituent members of the lamp unit 5 with a material having a high thermal conductivity and providing each of them with a heat radiating member such as a heat sink.

  As described above, the vehicular lamp according to the present invention has a lamp unit that uses an LED as a light source in a lamp chamber of the vehicular lamp, and has a heat dissipating fin integrated with a mount plate on which an LED mounting board is mounted. It was placed outside the lamp room of the lighting fixture. And the temperature rise of LED was suppressed by cooling a radiation fin with the external air taken in via the ventilation duct integrated with the vehicle lamp.

  As a result, since the cooling means for the radiating fins only includes the air duct, the necessary space is small, and the space for mounting the vehicle lamp can be reduced.

  In addition, since the air duct can be integrally formed with the housing, an increase in manufacturing cost including material costs and assembly costs can be suppressed.

  Further, since the cooling means does not have a movable mechanism, there is no fear of failure, and the reliability is not lowered by providing the cooling means.

  Further, since the heat radiation efficiency of the heat radiating fins is improved, it is possible to ensure sufficient heat radiating performance even if the size of the heat radiating fins is reduced, and the vehicle lamp can be reduced in size and weight.

  Therefore, it is possible to achieve a reduction in size and weight while ensuring the heat dissipation efficiency of the entire lamp, and it is possible to ensure a degree of design freedom even if restrictions are imposed on the installation space and weight of the lamp.

  Further, by directing the outside air inlet of the air duct toward the front of the vehicle, the traveling wind during traveling is taken into the air duct, and the radiating fin is cooled by forced cooling by the traveling air. As a result, the heat dissipation efficiency of the heat dissipation fins is increased and the temperature rise of the LED is greatly suppressed, and the decrease in the light emission efficiency of the LED light source is greatly reduced, and a predetermined amount of irradiation light can be secured.

  The LED serving as the light source may be an LED chip (bare chip) or an LED device in which the LED chip is mounted on a package.

It is sectional drawing of the vehicle lamp of this invention. It is a fragmentary sectional view of the vehicular lamp of the present invention. Similarly, it is a fragmentary sectional view of the vehicular lamp of the present invention. 1 is a front view of a motorcycle equipped with a vehicle lamp of the present invention. It is AA sectional drawing of FIG. 1 is a front view of a motorcycle equipped with a vehicle lamp of the present invention. It is BB sectional drawing of FIG. It is sectional drawing of the conventional vehicle lamp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle lamp 2 Front lens 3 Housing 4 Light chamber 5 Lamp unit 6 LED
DESCRIPTION OF SYMBOLS 7 LED mounting board 8 Mount plate 9 Reflector 10 Lens holder 11 Shielding body 12 Projection lens 13 Radiation fin 14 Outside air inlet 15 Outside air outlet 16 Air blow duct 17 Cowl 18 Running wind inlet 19 Opening part

Claims (3)

  At least one semiconductor light emitting element and an optical system for controlling the optical path of the light emitted from the semiconductor light emitting element are housed in a lamp chamber formed of a housing in which at least a front lens and an air duct are integrally provided, A vehicular lamp in which heat dissipating fins that dissipate heat generated in the semiconductor light emitting element are disposed outside the lamp chamber, wherein the air duct is located outside the light chamber, and at least the air duct A vehicular lamp characterized in that the radiating fin is cooled by outside air sucked from one outside air inlet.   The vehicular lamp according to claim 1, wherein the outside air intake port of the blower duct faces a substantially irradiation direction of the vehicular lamp.   The vehicular lamp is attached to the front cowl of the motorcycle in a state in which the outside air intake port of the air duct is in communication with a traveling wind intake port that opens in front of a front cowl of the motorcycle. The vehicular lamp according to any one of claims 1 and 2.

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