JP2007220619A - Vehicular led lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular LED lighting fixture that suppresses a temperature rise in LEDs by increasing the heat radiation properties of the self heat generation of the LEDs and securing a prescribed quantity of light irradiation by reducing a decrease in luminous efficiency in the LEDs in the vehicular LED lighting fixture with the LEDs as a light source. <P>SOLUTION: A front lens 1, a housing 2, and a rear cover 3 mainly form a lamp chamber 4. A first heat sink section 12 where a mount section 11 in which an LED light source 10 is placed is extended, and a second heat sink section 17 are arranged inside and outside the lamp chamber 4, respectively. The first and second heat sink sections 12, 17 are integrated while sandwiching the rear cover 3. Heat generated from the LED light source 10 is radiated to the outside of the lamp chamber 4 via the second heat sink section 17 and the front lens 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle LED lamp using an LED as a light source.

  A light emitting diode (hereinafter referred to as “LED”) has a characteristic that the light emission efficiency is lowered by a temperature rise. Possible causes of LED temperature rise include self-heating when the LED is turned on 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, vehicle headlamps using LEDs as light sources have been proposed and developed.

  A vehicular lamp generally has a lamp chamber formed of a front lens and a housing, and an LED serving as a light source is supported in the lamp chamber. Therefore, when the LED is turned on, the temperature of the LED itself increases due to the self-heating of the LED, and as a result, the light emission efficiency of the LED decreases, thereby reducing the amount of light emitted from the lamp and, in extreme cases, the distribution required for the lamp. There is also a possibility that the optical performance and the light distribution standard will not be satisfied.

  Accordingly, proposals have been made for vehicle headlamps that suppress the occurrence of the above problems. As shown in FIG. 3, the vehicle head includes a transparent cover 51, a lamp body 52, a vertical panel 53, a support bracket 56 in which a unit support 54 and a heat sink 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 semiconductor light emitting element 59 as a light source having the above configuration, the self-heating when the semiconductor light emitting element 59 is turned on is a unit support portion of the support bracket 56 formed of a material that is a good conductor of heat. 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).
JP-A-2005-141917

  In the conventional vehicle headlamp 50, most of the heat generated in the semiconductor light emitting device 59 is conducted from the unit support portion 54 of the support bracket 56 on which the semiconductor light emitting device 59 is mounted to the heat sink portion 55 to be heat sink. The light is dissipated outside the lamp chamber 58 at the section 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, in the case of the conventional vehicle headlamp 50, the socket cover 57 allows the heat sink portion 55 to be disposed within the socket cover 57. It will be limited. Therefore, since the size of the heat sink portion 55 is restricted, sufficient heat radiation efficiency cannot be obtained.

  Even if the socket cover 57 is not required, the degree of freedom in designing the dimensions of the heat sink portion 55 can be secured so that sufficient heat radiation efficiency can be obtained due to the restriction of the installation space of the vehicle headlamp 50. It is doubtful.

  Therefore, the present invention was devised in view of the above problems, and the object of the present invention is to secure a degree of freedom in designing a LED light source for a vehicle that uses an LED as a light source, and to provide a heat dissipation property for self-heating of the LED. An object of the present invention is to provide a vehicular LED lamp that suppresses an increase in the temperature of the LED by increasing the LED, thereby reducing a decrease in light emission efficiency of the LED and ensuring a predetermined amount of irradiation light.

  In order to solve the above-mentioned problem, in the invention described in claim 1 of the present invention, a lamp chamber is formed by at least a front lens, a housing, and a back cover, and includes at least one LED light source and the LED light source. A lamp unit having an optical system for controlling the optical path of the emitted light and a first heat sink part in which the LED light source is partially mounted is disposed inside the lamp chamber, and a second heat sink A portion is disposed outside the lamp chamber, and the first heat sink portion and the second heat sink portion are integrated with the back cover interposed therebetween.

  According to a second aspect of the present invention, in the first aspect, each of the first heat sink portion, the second heat sink portion, and the back cover is formed of a material that is a good heat conductor. It is characterized by being.

  Moreover, the invention described in claim 3 of the present invention is characterized in that, in any one of claims 1 and 2, the LED light source is one of an LED chip and an LED device including the LED chip. It is what.

  A vehicle LED lamp according to the present invention includes at least a front lens, a housing, and a back cover to form a lamp chamber, at least one LED light source, and an optical system that controls an optical path of light emitted from the LED light source; A lamp unit having a first heat sink portion on which the LED light source is partially mounted is disposed inside the lamp chamber, and a second heat sink portion is disposed outside the lamp chamber. The heat sink part and the second heat sink part were integrated with the back cover interposed therebetween.

  Then, heat generated by the LED light source is sequentially passed through the first heat sink portion and the back cover, and is then dissipated from the second heat sink portion to the outside of the lamp chamber, and from the first heat sink portion to the lamp chamber. Two channels of heat channels are provided which are diffused and conducted through the front lens and dissipated outside the lamp chamber.

  As a result, even if the amount of heat energy generated from the LED light source and dissipated from the second heat sink portion to the outside of the lamp chamber is restricted, there is heat energy dissipated from the lamp chamber to the outside of the lamp chamber through the housing. Therefore, it is possible to sufficiently ensure the heat radiation efficiency of the entire lamp, and by suppressing the temperature rise of the LED light source, it is possible to reduce a decrease in the light emission efficiency of the LED light source and to secure a predetermined irradiation light amount. Become.

  Therefore, it is possible to reduce the size of the second heat sink part while ensuring the heat dissipation efficiency of the entire lamp, and even if restrictions are imposed on the installation space of the lamp, the design freedom of the dimension can be maintained while maintaining the heat dissipation performance. It became possible to secure.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIG. 1 and FIG. 2 (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 according to a vehicle LED lamp of the present invention. In the present embodiment, the lamp chamber 4 is mainly formed by three members of the front lens 1, the housing 2 and the back cover 3. In the front lens 1 and the housing 2, a seal leg 6 provided at the peripheral end of the front lens 1 is inserted into a seal groove 5 provided at one front opening end of the housing 2, and the seal groove 5 and the seal leg are inserted. 6 is locked in a state in which the elastic sealing material 7 is filled in a gap with the gap 6.

  In this embodiment, the seal groove portion is provided on the housing side and the seal leg portion is provided on the front lens side. However, the seal groove portion may be provided on the front lens side and the seal leg portion on the housing side. As long as a locking portion having a sealing effect is formed by the housing and the housing, the structure of the locking portions, the locking means and the like are not particularly limited.

  The housing 2 and the back cover 3 are supported by a cover holder 8 formed of a flexible material.

  A lamp unit 9 is supported in the lamp chamber 4, and the lamp unit 9 has a first heat sink portion 12 having a mount portion 11 on which an LED light source 10 is mounted, a reflector 13, a shield 14, and the like. A lens holder 15 and a projection lens 16 are provided.

  Further, a second heat sink portion 17 is disposed outside the lamp chamber 4, and the first heat sink portion 12 of the lamp unit 9 supported in the lamp chamber 4 and the first heat sink portion 12 disposed outside the lamp chamber 4 are disposed. The two heat sink parts 17 are integrally fixed via a fixing screw with the back cover 3 interposed therebetween.

  When the LED light source for vehicles having the above-described configuration is turned on, the light emitted from the LED light source 10 includes an optical system including the reflector 13, the shield 14, the lens holder 15, and the projection lens 16. Through the front lens 1, the light is irradiated in front of the vehicle LED lamp.

  At the same time, as described in “Background Art”, the LED light source 10 self-heats when it is turned on, and the temperature of the LED itself rises due to the self-heating, resulting in a decrease in the luminous efficiency of the LED. The amount of irradiation light is reduced.

  Therefore, in the present invention, means for suppressing the temperature rise when the LED light source is turned on is provided, and will be described in detail with reference to FIG.

  First, when the LED light source 10 is turned on, the heat generated by the LED light source 10 extends from the first heat sink portion 12 and moves to the mount portion 11 on which the LED light source 10 is mounted. The first heat sink portion 12 is formed of a material that is a good conductor of heat, and the heat that has moved from the LED light source 10 to the mau mount portion 11 is conducted through the mount portion 11 and moves to the first heat sink portion 12.

  The first heat sink part 12 is provided with a plurality of heat radiation fins 19 arranged in parallel with a predetermined distance from each other, and the heat transferred to the first heat sink part 12 is conducted inside each heat radiation fin 19. It reaches the end of the first heat sink part 12 and moves to the back cover 3 via a contact interface 20 between the end of the first heat sink part 12 and one surface of the back cover 3.

  The back cover 3 is also made of a material that is a good heat conductor, and heat transferred from one surface of the back cover 3 into the back cover 3 is conducted inside the back cover 3 and reaches the other surface of the back cover 3. Then, it moves to the second heat sink portion 17 via the contact interface 21 between the other surface of the back cover 3 and the end portion of the second heat sink portion 17.

  The second heat sink portion 17 is also formed of a material that is a good heat conductor, and includes a plurality of heat radiation fins 22 arranged in parallel at a predetermined interval from each other. The heat transferred into the heat sink portion 17 is conducted through the inside of each radiation fin 22 and reaches the surface of each radiation fin 22.

  The heat that reaches the surface of each radiating fin 22 is transferred to the air in the vicinity of the surface, moves, and is dissipated into the atmosphere using air as a medium.

  As described above, in the configuration of the vehicular LED lamp according to the present invention, until it is emitted from the entire surface of the heat radiation fin 22 of the second heat sink portion 17 generated by the LED light source 10 and disposed outside the lamp chamber 4 to the atmosphere. In addition to this, a part of the heat generated by the LED light source 10 and moved to the first heat sink portion 12 is part of the entire surface of the radiation fin 19 of the first heat sink portion 12. The heat is transferred from the lamp to the nearby air and diffused into the lamp chamber 4.

  By the way, a lamp mounted on a vehicle generally forms a boundary surface with the atmosphere outside the vehicle via a front lens, and maintains a thermal equilibrium state when a temperature difference occurs between the inside of the lamp chamber 4 and the outside of the lamp chamber 4. In order to do this, heat is conducted through the front lens and moves from the high temperature side to the low temperature side. Therefore, in the above case, the inside of the lamp chamber 4 is in a high temperature state with respect to the atmosphere 23 outside the lamp chamber 4, and the heat in the lamp chamber 4 is conducted through the front lens 1 and the front lens outside the lamp chamber 4. It moves to the air in the vicinity of 1 and is diffused into the atmosphere 23 through the air.

  That is, the heat generated in the LED light source 10, moved to the first heat sink portion 12, transferred from the entire surface of the radiation fin 19 of the first heat sink portion 12 to the nearby air, and dissipated in the lamp chamber 4. However, it will be dissipated in the air | atmosphere 23 outside a vehicle via the front lens 1, and a favorable heat dissipation effect will be exhibited.

  As described above, the vehicular LED lamp according to the present invention has second self-heat generated when the LED light source 10 is turned on and moved to the second heat sink 17 and self-heat dissipated in the lamp chamber 4. The heat radiation effect was obtained by radiating the entire surface of the heat radiating fins 22 of the heat sink 17 and the front lens 1 to the outside of the lamp chamber 4.

  As a result, even if the amount of thermal energy generated from the LED light source and dissipated from the heat radiation fins 22 of the second heat sink portion 17 to the outside of the lamp chamber 4 is restricted, the lamp is lit from the lamp chamber 4 through the housing 1. Since there is thermal energy dissipated outside the room 4, it is possible to sufficiently ensure the heat dissipation efficiency of the entire lamp, and by suppressing the temperature rise of the LED light source 10, the light emission efficiency of the LED light source 10 is reduced. As a result, the predetermined irradiation light quantity can be secured.

  Therefore, it is possible to reduce the size of the second heat sink portion 17 while ensuring the heat radiation efficiency of the entire lamp, and it is possible to ensure the degree of freedom in designing the dimensions even if there is a restriction on the mounting space of the lamp. It becomes.

  In addition, the shape and dimension of the radiation fin formed in each of the 1st heat sink part and the 2nd heat sink part are set in consideration of various conditions, such as the space which can be arrange | positioned and heat radiation efficiency.

  The LED light source may be an LED bare chip (LED chip) or an LED device on which the LED chip is mounted.

It is sectional drawing of the LED lamp for vehicles of this invention. Similarly, it is a reference view showing the process of heat transfer of the LED lamp for vehicles of the present invention. It is sectional drawing of the conventional vehicle lamp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front lens 2 Housing 3 Back cover 4 Lamp chamber 5 Seal groove part 6 Seal leg part 7 Seal material 8 Cover holder 9 Lamp unit 10 LED light source 11 Mount part 12 First heat sink part 13 Reflector 14 Light shield 15 Lens holder 16 Projection lens 17 Second heat sink part 18 Fixing screw 19 Radiation fin 20 Contact interface 21 Contact interface 22 Radiation fin 23 Atmosphere

Claims (3)

  A lamp chamber is formed by at least a front lens, a housing, and a back cover, and at least one LED light source, an optical system that controls an optical path of light emitted from the LED light source, and the LED light source are mounted in part. A lamp unit having a first heat sink portion provided therein is disposed inside the lamp chamber, a second heat sink portion is disposed outside the lamp chamber, and the first heat sink portion and the first heat sink portion A vehicle LED lamp characterized in that a second heat sink portion is integrated with the back cover interposed therebetween.   2. The vehicular LED lamp according to claim 1, wherein each of the first heat sink portion, the second heat sink portion, and the back cover is formed of a material that is a good conductor of heat.   3. The vehicular LED lamp according to claim 1, wherein the LED light source is one of an LED chip and an LED device including the LED chip. 4.

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