JP4661740B2 - LED lights for vehicles - Google Patents

Description

  The present invention relates to a vehicular LED lamp using an LED (light emitting diode) as a light source, and more particularly to a technique for removing fogging on the lens inner surface of the lamp.

  For example, in a vehicular lamp such as a headlight, when an incandescent bulb, a halogen bulb, or a xenon bulb is used as a light source, air heated by far-infrared rays contained in these rays convects the lamp, The interior is ventilated and the inner surface of the lens is removed.

On the other hand, in a vehicular LED lamp that uses an LED (particularly a white LED) as a light source, the far-infrared rays are not included in the light beam, so that the fogging of the inner surface of the lens cannot be removed. Therefore, as a technique for effectively ventilating the interior of the lamp and removing the fog on the inner surface of the lens, for example, a lamp provided with a heating element (see Patent Document 1) or a fan motor is used to rotate the fan. (See Patent Document 2) has been proposed.
JP 2004-314902 A JP 2004-253325 A

  However, since the technology described in Patent Documents 1 and 2 requires a fan and a heating element, it is necessary to operate them and power consumption deteriorates. In addition, these techniques require a fan and a heating element, so that the number of parts increases and the cost of the entire lamp increases.

  Therefore, an object of the present invention is to provide a vehicular LED lamp that can remove fog on the inner surface of a lens at a low cost without using a fan or a heating element.

The vehicle LED lamp according to the present invention is warmed by the LED as the light source provided in the housing, the heat generated when the LED is turned on, and the heat taken from the LED is transferred to the surrounding air. A heat sink provided at the lowermost or uppermost part in the housing for convection of the air, a ventilation hole for air introduction and air discharge provided in the housing, and air in the housing to the inner surface of the outer lens A lower air flow path for guiding the air and an upper air flow path for guiding the air flowing upward along the inner surface of the outer lens to the ventilation hole for discharging the air, and a heat sink at the bottom of the housing In the case where the heat sink is provided, the heat sink is provided in the middle of the flow path of the outside air flowing into the housing from the ventilation hole for introducing air to the lower air flow path. In the case where the heat sink is provided at the uppermost part in the wing, the heat sink is provided in the middle of the air flow path from the upper air flow path to the air exhaust ventilation hole .

  According to the vehicle LED lamp of the present invention, the heat sink for cooling the heat generated by the lighting of the LED is provided at the lowermost part in the housing, and further, the air flow path for guiding the air in the housing to the inner surface of the outer lens is provided. Therefore, the heat existing in the periphery of the heat sink is heated by taking the heat of the LED, and air convection is generated in the lamp, and the heated air passes from the lower part of the housing through the air flow path to the inner surface of the outer lens. By raising along, the cloud of the inner surface of the outer lens can be removed. Further, according to the LED lamp for a vehicle, outside air is introduced into the lamp from one ventilation hole and the outside from the other ventilation hole by convection generated in the lamp and movement of air flowing through the air flow path. And the air in the lamp is exhausted, forming a ventilation cycle in the lamp.

  On the other hand, according to the vehicular LED lamp of the present invention, a heat sink for cooling the heat generated by the lighting of the LED is provided at the top of the housing, and an air flow path for guiding the air in the housing to the inner surface of the outer lens is provided. In addition, since the ventilation hole is provided in the housing, the air around the heat sink is warmed by the heat of the LED, and the warm air is discharged from the ventilation hole to the outside of the lamp, and convection is generated in the lamp due to the flow of the air. The air in the outer lens rises along the inner surface of the outer lens through the air flow path, so that the fog on the inner surface of the outer lens can be removed. Further, according to the LED lamp for a vehicle, outside air is introduced into the lamp from one ventilation hole and the outside from the other ventilation hole by convection generated in the lamp and movement of air flowing through the air flow path. The air in the lamp can be discharged and form a ventilation cycle in the lamp.

  Therefore, according to the vehicular LED lamp of the present invention, it is possible to efficiently remove the fog on the inner surface of the outer lens with a simple configuration using heat generated by the lighting of the LED without using a fan or a heating element. Can do.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

“Embodiment 1”
FIG. 1 is a cross-sectional view of the vehicular LED lamp of the first embodiment, and FIG. 2 is a diagram showing the air flow in the vehicular LED lamp of the first embodiment. The present embodiment is an example in which a vehicular LED lamp using an LED as a light source is applied to a headlight.

  As shown in FIG. 1, the vehicular LED lamp according to the first embodiment includes a housing 2 to which an outer lens 1 is mounted, a heat sink 3 provided at the lowermost portion of the housing 2, and a heat sink 3 in proximity to the housing 2. The LED 4 as a light source provided, the upper ventilation hole 5 for introducing air and the lower ventilation hole 6 for discharging air provided in the housing 2, and the air in the housing 2 are guided to the inner surface 1a of the outer lens 1. An air flow path 7, a reflector 8 that emits light from the LED 4 to the outside of the lamp, a light shielding plate 9 (cut line shade), and a lens 10 are provided.

  The outer lens 1 is mounted so as to cover the front surface of the housing 2 that houses the heat sink 3, the LED 4, the reflector 8, the light shielding plate 9, and the lens 10. The heat sink 3 is a cooling device that cools the LED itself by dissipating heat generated when the LED 4 is turned on. The heat sink 3 is disposed at the lowermost position in the housing 2 in order to transfer the heat taken from the LED 4 to the surrounding air to heat it and convect the warm air in the lamp. The heat sink 3 is provided with a plurality of radiating fins 11 on the bottom side in order to increase the cooling efficiency.

  The LED 4 is fixed to the upper surface 3 a of the heat sink 3. It is preferable to apply and fix the sheet | seat, grease, etc. which were excellent in thermal conductivity, in order for LED4 to transfer the heat | fever which generate | occur | produced by lighting to the heat sink 3 efficiently. In addition, fixing the LED 4 to the upper surface 3 a of the heat sink 3 improves the thermal conductivity to the heat sink 3.

  The reflector 8 is formed as an elliptic parabolic shape, and is provided so as to cover the upper part of the LED 4. The reflector 8 collects the light emitted from the LED 4 and focuses the focal point 12 at a predetermined position in the housing 2. The light shielding plate 9 forms a cut line between the lens 10 and the reflector 8 to narrow the irradiation range on the driver's seat side. The lens 10 emits the light from the LED 4 whose focal point 12 is formed by the reflector 8 to the outside of the lamp as a light distribution suitable for traveling of the vehicle.

  The vehicle LED lamp is provided with an air flow path 7 for guiding the air heated by the heat exchange between the LED 4, the heat sink 3 and the surrounding air to the front inner surface 1 a of the outer lens 1. It has been. The air flow path 7 is composed of a bottom surface 1b of the outer lens 1 and a lower inner panel 13A. Between the bottom surface 1b of the outer lens 1 and the inner panel 13A, the front surface of the outer lens 1 from the heat sink 3 is formed. It is comprised as a flow path which flows air to the part inner surface 1a.

  In addition, the air flow path 7 is configured to incline upward from the housing 2 side toward the front inner surface 1a side of the outer lens 1 so that the heat around the heat sink heated by the LED 4 smoothly flows to the outer lens. 1 to the front inner surface 1a. The inlet end side portion 7 </ b> A, which is one end side of the air flow path 7, is provided in the vicinity of the radiating fin 11 provided at the lower portion of the heat sink 3. On the other hand, the outlet end side portion 7B which is the other end side of the air flow path 7 rises along the front inner surface 1a of the outer lens 1 from the gap between the front inner surface 1a of the outer lens 1 and the inner panel 13A. It is provided to do.

  The upper ventilation hole 5 is provided at the upper part of the rear surface 2a of the housing 2, and the lower ventilation hole 6 is provided at the lower part of the rear surface 2a of the housing 2 similarly. In particular, the lower ventilation hole 6 is provided at a position further lower than the inlet end side portion 7 </ b> A of the air flow path 7. From the upper ventilation hole 5, the air in the lamp is discharged to the outside of the lamp, and from the lower ventilation hole 6, the outside air flows into the lamp.

  According to the vehicular LED lamp configured as described above, since the heat sink 3 for cooling the heat generated from the LED 4 is provided at the bottom of the housing 2, the air around the heat sink 3 is transferred to the heat sink 3. As a result of being warmed by the heat taken away in step 2, convection is generated in the lamp. Further, the warmed air flows to the front inner surface 1a of the outer lens 1 through the air flow path 7 inclined upward from the inlet end side portion 7A toward the outlet end side portion 7B. Since it rises along the inner surface 1a, the fog on the inner surface of the outer lens is removed.

  And the air which flowed above the outer lens 1 is discharged | emitted out of a lamp from the upper side ventilation hole 5 provided in the upper part of the housing 2. FIG. Due to the movement of the air, outside air flows into the lamp from the lower ventilation hole 6. Thus, according to the vehicle LED lamp of the present embodiment, the lower ventilation hole 6, the heat sink 3, the air flow path 7, the front inner surface 1a of the outer lens 1 and the upper ventilation hole 5 are routed in this order. A ventilation cycle is formed, and air is always supplied to the inner surface of the outer lens, so that the clouding can be efficiently removed with a simple configuration without using a fan or a heating element.

  Further, according to the vehicle LED lamp of the present embodiment, since the air flow path 7 is inclined upward from the housing 2 side toward the front inner surface 1a side of the outer lens 1, the heat around the heat sink is heated. Air can be smoothly guided to the front inner surface 1 a of the outer lens 1.

  Further, according to the vehicular LED lamp of the present embodiment, the air flow path 7 is constituted by the bottom surface 1b of the outer lens 1 and the inner panel 13A disposed at a predetermined distance from the bottom surface 1b. As a result, it is possible to use existing parts without using dedicated parts for forming the air flow path, and to reduce the cost of the apparatus.

  Moreover, according to the vehicle LED lamp of the present embodiment, the housing 2 is provided with the ventilation holes (the upper ventilation hole 5 and the lower ventilation hole 6), so that the air in the lamp can be efficiently convected. Become.

  Further, according to the vehicle LED lamp of the present embodiment, since the heat sink 3 is provided in the housing 2, the heat sink 3 is not directly exposed to the high-temperature air even when the air outside the lamp becomes high temperature. The temperature influence on the LED 4 by the outside air of the lamp can be reduced.

  Further, according to the vehicle LED lamp of the present embodiment, the LED 4 itself is not heated forcibly using the heating element, but the LED 4 itself is not heated.

  Moreover, according to the LED lamp for vehicles of this Embodiment, since the heat sink 3 which is a thermal radiation part exists in the vicinity of LED4 which is a heat generating part, LED4 can be cooled effectively.

“Embodiment 2”
FIG. 3 is a sectional view of the vehicular LED lamp according to the second embodiment. The second embodiment is an example in which the air flow path 7 is configured by providing the air flow path configuring member 14 as a separate part on the lower inner panel 13A.

  In the first embodiment, the air flow path 7 is formed between the lower inner panel 13A itself and the bottom surface 1b of the outer lens 1 by extending the lower inner panel 13A itself to a position where the heat sink 3 is provided. The air flow path 7 is formed by attaching the air flow path constituting member 14 which is a separate part to the inner panel 13A.

  If the air flow path 7 is configured as a separate part in this way, the existing inner panel 13A can be used as it is, and the air flow path 7 can be used without adding much cost by adding only the air flow path constituting member 14. Can be configured.

“Embodiment 3”
FIG. 4 is a cross-sectional view of the vehicular LED lamp of the third embodiment, and FIG. 5 is a diagram showing the air flow in the vehicular LED lamp of the third embodiment. In the third embodiment, the heat sink 3 is arranged on the top of the housing 2 and the LED 4 is provided on the lower surface of the heat sink 3. The other parts are basically the same as in the first embodiment.

  In the vehicular LED lamp according to the third embodiment, the heat sink 3 is disposed on the uppermost portion of the housing 2, and the LED 4 is disposed on the lower surface 3 c of the heat sink 3. In addition, the difference from Embodiment 1 is that light is distributed only by the reflector 8 having an elliptical paraboloid shape without using the lens 10 and the light from the LED 4 is emitted to the outside of the lamp. The air flow path constituting member 14 attached to the inner panel 13A is formed with the air flow path 7 and the upper side between the upper inner panel 13B provided on the upper part of the lamp and the top surface 1c of the outer lens 1. The air flow path 15 is formed.

  In the vehicular LED lamp according to the third embodiment, the heat sink 3 is disposed on the upper portion of the housing 2, so that the heat generated by the LED 4 being turned on is taken away by the heat sink 3, and the surrounding air is warmed up. As the air is discharged from the ventilation hole 5 to the outside of the lamp, outside air is introduced into the lamp from the lower ventilation hole 6 by the movement of the air, and passes through the lower air flow path 7 to the front portion of the outer lens 1. A ventilation cycle that rises along the inner surface 1a and flows through the upper air flow path 15 is formed.

  According to the vehicle LED lamp of the third embodiment, air can be supplied to the inner surface of the outer lens by generating convection in the lamp without using a fan or a heating element, as in the first embodiment. Therefore, the fog can be removed efficiently with a simple configuration.

  Although specific embodiments to which the present invention is applied have been described above, the above-described embodiments are merely examples of the present invention and are not limited to the above-described embodiments.

1 is a cross-sectional view of a vehicle LED lamp according to a first embodiment. FIG. 3 is a diagram showing the flow of air in the vehicle LED lamp according to the first embodiment. It is sectional drawing of the LED lamp for vehicles of Embodiment 2. 6 is a cross-sectional view of a vehicle LED lamp according to Embodiment 3. FIG. FIG. 6 is a diagram showing the flow of air in the vehicular LED lamp of the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer lens 1a ... Front part inner surface of outer lens 2 ... Housing 3 ... Heat sink 4 ... LED (light source)
5 ... Upper ventilation hole (ventilation hole)
6 ... Lower ventilation hole (ventilation hole)
7, 15 ... Air flow path 8 ... Reflector 9 ... Shading plate (cut line shade)
DESCRIPTION OF SYMBOLS 10 ... Lens 11 ... Radiation fin 13A, 13B ... Inner panel 14 ... Air flow path structural member 15 ... Air flow path

Claims (6)

A housing for mounting an outer lens;
An LED which is a light source provided in the housing;
A heat sink provided at the lowermost or uppermost part in the housing for radiating heat generated when the LED is lit and transferring heat taken from the LED to the surrounding air to convect warm air ; ,
A ventilation hole for air introduction and air discharge provided in the housing;
A lower air flow path for guiding the air in the housing to the inner surface of the outer lens;
An upper air flow path that guides the air flowing upward along the inner surface of the outer lens to the ventilation hole for air discharge;
In the case where the heat sink is provided at the lowermost part in the housing, the heat sink is placed in the middle of the flow path of outside air flowing into the housing from the ventilation hole for introducing air to the lower air flow path. Provided,
When the heat sink is provided at the uppermost part in the housing, the heat sink is provided in the middle of the air flow path that flows from the upper air flow path to the ventilation hole for air discharge. LED lighting for vehicles. The LED lamp for a vehicle according to claim 1,
The lower air flow path is inclined upward from the housing side toward the front inner surface side of the outer lens. The vehicle LED lamp according to claim 2,
The lower air flow path is configured by a bottom surface of the outer lens and an inner panel or a member connected to the inner panel that is disposed above the bottom surface at a predetermined distance. LED lamp for vehicles. The LED lighting device for a vehicle according to any one of claims 1 to 3,
At least one or more ventilation holes are provided in the upper part of the housing. The vehicle LED lighting device according to any one of claims 1 to 4,
At least one or more ventilation holes are provided in the lower part of the housing. The LED lamp for vehicles according to any one of claims 1 to 5,
The LED as the light source is provided in the vicinity of the heat sink.

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