JP2007172932A - Vehicular headlight - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular headlight using an LED and having high heat dissipating effect, which can be miniaturized. <P>SOLUTION: This vehicular headlight is composed of a lamp body 2 having at least a translucent surface side opening part, a translucent cover 1 covering the translucent surface side opening part, and a lamp fixture 4 built in the lamp body 2, which contains a base part 6 made of a metal and an LED 9 installed on the base part 6, and can swivel. The lamp body 2 also has a back surface side opening part and a heat sink 11 mounted to the back surface side opening, and the base part 6 of the lamp fixture 4 has a slide surface to transmit heat by sliding with the heat sink 11. Heat generated when the LED 9 emits light is transmitted to the heat sink 11 from the slide surface of the base part 6 to be dissipated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle headlamp, and more particularly, to a vehicle headlamp using an LED as a light emitter.

  The vehicle headlamp is desired to be miniaturized for the purpose of securing other space in the engine room. For such a miniaturization, for example, a vehicle headlamp using an LED as a light emitter has been proposed. LEDs have also become increasingly bright due to technological innovation, and high-power LED lamps exceeding 1 W have been developed. However, in the case of a high-power LED lamp, high-temperature heat generation occurs when energized to emit light, and as a result, the brightness decreases due to its own heat generation (100 ° C. or higher), and the lifetime also decreases.

  Therefore, when the LED is used, it is possible to reduce the size of the light emitter, but since the LED itself generates heat and malfunctions due to the temperature rise of the LED, the LED needs to be cooled. For example, it is conceivable to attach a radiating fin to the back side of the LED in the lamp case to suppress heat generation. However, a small radiating fin raises the temperature of the fin itself, so that the effect cannot be expected. This inevitably increases the size of the heat dissipating fins, and increases the size of the lamp case itself.

Therefore, for example, in order to improve the cooling effect, the vehicle lighting device described in Patent Document 1 has a configuration in which a cover is provided outside the light emitting unit having the LED, and the outside air is guided to the LED through a gap between the cover and the light emitting unit. It is disclosed.
JP 2005-122945 A

  However, in Patent Document 1, a light emitting unit having an LED is integrated with a heat radiating fin that radiates heat. For this reason, in order to rotate the light emitting unit, it is necessary to rotate the integrated radiation fin together. Therefore, a space for allowing rotation of the heat dissipating fins is also required, which has been a problem for downsizing.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle headlamp that has a heat dissipating means using LEDs and can be further miniaturized.

Means for Solving the Problems and Effects of the Invention

  Therefore, as a result of intensive research and trial and error to solve this problem, the present inventor can fix the heat sink by structurally separating the heat sink, which is the heat dissipation part of the LED, from the swiveling lamp including the LED, It has been confirmed that the vehicle headlamp can be reduced in size by eliminating the space necessary for swiveling the heat sink, and the present invention has been completed.

  That is, the vehicle headlamp according to the present invention includes at least a lamp body having a light-transmitting surface side opening, a light-transmitting cover that covers the light-transmitting surface-side opening, and is incorporated in the lamp body and is made of metal. A vehicle headlamp comprising a base and an LED installed on the base, and capable of swiveling, wherein the lamp body further has a back side opening and the back side opening The base of the lamp has a sliding surface that is in sliding contact with the heat sink and transmits heat, and heat generated when the LED emits light is generated from the sliding surface of the base. It is characterized in that heat is transferred to the heat sink to be dissipated.

  By not disposing the heat sink in the lamp body, a space for swiveling the heat sink in the lamp body becomes unnecessary, and the lamp body can be downsized. Further, since the heat sink is provided outside the lamp body, the heat dissipation from the heat sink is improved, and the heat sink can be further reduced in size. Therefore, the vehicle headlamp can be further reduced in size.

  A plurality of the lamps may be provided. Each lamp can be swiveled in each set direction, and a predetermined light distribution pattern can be formed.

  Further, the sliding contact surface of the lamp and the heat sink are along a circle centered on an axis where the lamp is swiveled, and at least a part of the sliding contact surface is always connected to the heat sink even when the lamp is swiveled. It must be in sliding contact.

  Since at least a part of the sliding surface is always in sliding contact with the heat sink, the heat of the lamp can always be transferred to the heat sink. Further, a lubricant that can conduct heat, such as heat radiation grease, may be applied to the sliding contact surface. By applying a lubricating material capable of conducting heat to the sliding contact surface, fine irregularities on the sliding contact interface are filled, and the contact area increases and heat conduction becomes easier.

  In addition, the lamp includes a reflector that is installed on the base and reflects the light of the LED and guides the light in an irradiation direction, a projection lens that is installed on the base and projects the light reflected by the reflector, and the base. And an actuator for swiveling.

  By having a reflector and a projection lens arranged at the base, and having an actuator for swiveling the base, the light from the LED can be distributed in a set direction.

  In addition, the actuator can be swiveled in conjunction with the vehicle posture.

  The heat sink may have a fin-shaped heat radiation portion. By having a fin-shaped heat radiation part, the surface area used for heat radiation increases and heat radiation becomes easier.

  According to the vehicle headlamp of the present invention, it is possible to efficiently dissipate heat by transferring self-heat generated by light emission of the high-intensity LED to a heat sink disposed outside the lamp body. In addition, since the heat sink can be fixed outside the lamp body, it is not necessary to swivel integrally with the lamp, and it is not necessary to have the space necessary for swiveling the heat sink in the lamp body, thereby reducing the size of the lamp body. Further, since the heat sink is disposed outside the lamp body, the heat dissipation efficiency of the heat sink is improved and the heat sink itself can be downsized. Therefore, a miniaturized vehicular headlamp having a good cooling effect in a swiveling vehicular headlamp using LEDs can be realized.

  Next, the present invention will be described in more detail with reference to the drawings. The present invention is not limited to the following embodiment. The present invention can be carried out in various forms with modifications and improvements that can be made by those skilled in the art without departing from the scope of the present invention.

  FIG. 1 is a cross-sectional view of an embodiment of a vehicle headlamp according to the present invention. FIG. 2 is a perspective view of an embodiment of a vehicle headlamp according to the present invention.

  As shown in FIG. 1, the vehicle headlamp includes a lamp body 2 having a translucent surface side opening and a back surface side opening, a translucent cover 1 covering the translucent surface side opening, and the lamp. A lamp 4 incorporated in the body 2 and a heat sink 11 attached to the back side opening of the lamp body 2 are included.

  The lamp body 2 incorporates a lamp 4. It is desirable that the lamp body 2 is made as small as possible while ensuring a space for the lamp 4 to swivel. In order to reduce the weight, the lamp body 2 is preferably made of resin.

  The translucent cover 1 covers the translucent surface side opening of the lamp body 2 and is in close contact with the lamp body 2 so that the inside of the lamp body is airtight. The translucent cover is preferably made of a resin, and examples of the resin material include an epoxy resin, an acrylic resin, and a polycarbonate resin.

  The lamp 4 is provided with an LED 9 on the base 6. A plurality of LEDs 9 may be installed in the lamp 4. The base 6 is provided with a semi-dome-shaped reflector 8 provided on the upper side of the LED 9 disposed thereon and reflecting the light of the LED, and a bowl-shaped projection lens 5 for projecting the light reflected by the reflector 8 on the front side of the base. Is provided.

  The base 6 is provided with an actuator 13 for supporting the base 6 and swiveling the base 6 below the base 6. The actuator 13 can swivel the base 6 left and right according to the steering angle and the like to change the light irradiation direction of the LED left and right. The actuator 13 is not particularly limited as long as the lamp 4 can be swiveled.

  The projection lens 5 has a function of collecting and distributing the light of the LED. The reflector 8 has a function of reflecting the light of the LED and guiding it to the projection lens 5. The light of the LED guided to the projection lens 5 is distributed and reflected from the mortar-shaped extension reflector 3 that extends from the lamp body 2 to the opening side of the translucent surface of the lamp body 2 and bends inward obliquely. Led to. The extension reflector 3 has a mirror surface on which the outer surface is vapor-deposited with aluminum, and has a function of reflecting the light irradiated from the projection lens 5 and guiding it in the irradiation direction. The extension reflector 3 is installed for each lamp 4. The extension reflector 3 is not particularly limited, but is preferably made of a resin such as PMMA.

  The LED 9 is a high-brightness LED. Examples of usable LEDs include LUXEON III (trade name) manufactured by LUMILEDS. High-brightness LEDs are accompanied by high-temperature heat generation when energized and light-emitted, and thus are heated by self-heating. In general, when the temperature of a high-brightness LED approaches its maximum junction temperature, problems such as a decrease in luminous flux, a change in emission color, a decrease in luminance, and a decrease in life occur. Therefore, the LED needs to be cooled to be below the maximum junction temperature. More preferably, it is preferably cooled to 150 ° C. or lower in order to prevent thermal deterioration of the constituent resin.

  Therefore, the base 6 also has a function of transferring the self-heating of the LED 9 accompanying light emission to the heat sink 11. The base 6 is made of metal, and examples of the metal constituting the base 6 include copper and aluminum having excellent thermal conductivity. The base 6 has a sliding contact surface in sliding contact with the heat sink 11 on the back side.

  The heat sink 11 is also made of metal, and examples of the metal constituting the heat sink 11 include copper and aluminum having excellent thermal conductivity.

  The heat sink 11 is attached to the back side opening of the lamp body 2 by a packing 12 so as to protrude outside the lamp body 2. The slidable contact surface of the base 6 and the surface of the heat sink 11 on the base 6 side have a curved shape along a circle in which the lamp 4 is swiveled, and a heat dissipating grease 10 is disposed between the base 6 and the heat sink 11. Yes. The heat dissipating grease 10 can fill the fine irregularities of the sliding contact interface between the base 6 and the heat sink 11, increase the contact area, and improve the heat transfer effect.

  Even if the lamp 4 is swiveled, at least a part of the sliding surface of the base 6 and the heat sink 11 is always in sliding contact, and the heat of the base 6 is always transferred to the heat sink 11 via the heat radiating grease 10.

  FIG. 2 shows a perspective view of one embodiment of the present invention. FIG. 2 shows an embodiment in which two lamps 4 are built in the lamp body 2, but the number of the lamps 4 is not particularly limited. In addition, the heat sink 11 is configured for each lamp 4 in FIG. 2, but the number of the heat sinks 11 is not limited, and one heat sink may be in sliding contact with a plurality of lamps. In FIG. 2, the swiveled lamp 4 'is indicated by a dotted line. At least a part of the swiveled lamp 4 ′ is in sliding contact with the heat sink 11 on the sliding contact surface of the base 6.

  The heat sink 11 has a heat dissipation part. The shape of the heat dissipation part is not particularly limited, but preferably has a fin shape. The heat sink 11 radiates the heat transferred from the base 6 from the heat radiating portion to the outside of the lamp body 2. When the heat radiating portion has a fin shape, the surface area for heat radiation increases and the heat radiation efficiency is improved.

  The heat sink 11 protrudes and is fixed to the outside of the lamp body 2 by the packing 12. Therefore, the swivel movable space of the heat sink 11 is not required in the lamp body 2, and the lamp body 2 can be reduced in size by that space. Further, since the heat sink 11 is disposed outside the lamp body 2 in an airtight state, it can come into contact with the outside air, and the heat dissipation efficiency from the heat sink 11 is improved. Therefore, the heat sink 11 can be reduced in size according to its thermal efficiency.

  Although the above embodiment has been described as a vehicle headlamp, for example, the vehicle headlamp can be applied to a headlamp, a fog lamp, or the like.

It is sectional drawing of the vehicle headlamp of one Embodiment of this invention. It is a perspective view which shows the vehicle headlamp of one Embodiment of this invention.

Explanation of symbols

1, translucent cover, 2, lamp body, 3, extension reflector, 4, lamp 4 'swiveled lamp, 5, projection lens, 6, base, 7, lamp swivel shaft,
8, reflector, 9, LED, 10, heat radiation grease, 11, heat sink,
12, packing, 13, actuator.

Claims (5)

A lamp body having at least a translucent surface side opening, a translucent cover covering the translucent surface side opening, a base made of metal incorporated in the lamp body, and an LED installed on the base. A vehicle headlight comprising a lamp that can be swiveled,
The lamp body further includes a heat sink attached to the back side opening and having a back side opening,
The base of the lamp has a sliding surface that transmits heat by sliding contact with the heat sink,
The vehicle headlamp is characterized in that heat generated when the LED emits light is transferred from the sliding surface of the base to the heat sink to be dissipated.   The vehicle headlamp according to claim 1, wherein a plurality of the lamps are provided.   The sliding contact surface of the lamp and the heat sink are along a circle centered on an axis on which the lamp swivels, and at least a part of the sliding contact surface always slides on the heat sink even when the lamp is swiveled. The vehicle headlamp according to claim 1, which is in contact with the vehicle headlamp.   The lamp is installed on the base and reflects the light of the LED and guides the light in the irradiation direction, a projection lens that is installed on the base and projects the light reflected by the reflector, and swivels the base The vehicle headlamp according to any one of claims 1 to 3, further comprising an actuator to be operated. The vehicular headlamp according to any one of claims 1 to 4, wherein the heat sink has a fin-shaped heat radiation portion.

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