JP5110578B2 - Vehicle lighting - Google Patents

Description

  The present invention relates to a vehicular lamp such as a headlamp having an AFS function using a semiconductor light emitting element as a light source.

2. Description of the Related Art Conventionally, a vehicular lamp having an AFS function that uses a semiconductor light emitting element as a light source is configured, for example, as shown in FIG.
That is, in FIG. 3, a vehicular lamp 1 is a headlight of an automobile, and a resin-made casing 2 whose front surface is open, and an AFS (Adaptive) supported in the casing 2 so that the optical axis can be changed. Front-lighting system) bracket 3, at least one light source unit 4 arranged to irradiate light forward in the light irradiation direction in the AFS bracket 3, and the front surface of the housing 2 are liquid-tightly covered. The front lens 5 is attached to the front open end of the housing 2 as described above.

The AFS bracket 3 includes a rear wall, left and right side walls, an upper wall, and a lower wall so that the front surface is open.
Further, the AFS bracket 3 is supported in the housing 2 so as to be swingable around, for example, a vertical shaft 3a.

  The light source unit 4 irradiates at least one semiconductor light emitting element 4b such as an LED mounted on the substrate 4a and the light from the semiconductor light emitting element 4b forward in the light irradiation direction (left side in the figure). And an elliptical reflecting surface 4c and a projection lens 4d in the illustrated case.

Further, the light source unit 4 includes a heat sink 4e to dissipate heat generated when the semiconductor light emitting element 4b is driven.
The heat sink 4e is attached to the front side of the upper surface with the lower surface of the substrate 4a in thermal contact with the heat conductive material 4f.
The rear end of the heat sink 4e is similarly attached to the small bracket 4g via the heat conductive material 4f.

Here, the small bracket 4g has an L-shaped cross section, and is arranged such that the rising portion faces the rear wall 3b of the AFS bracket 3 and the base portion extends forward.
At this time, the small bracket 4g is not closely attached to the AFS bracket 3 and arranged at a slight interval so as not to interfere with the AFS bracket 3 in the region of the rising portion in the above-described adjustment of the optical axis. Yes.
Further, the small bracket 4g is supported on the rear wall 3b of the AFS bracket 3 in the vicinity of the lower end of the rising portion.

Among the light source units 4, one light source unit 4 is fixedly attached to the rear wall 3 b of the AFS bracket 3 by a plurality of bosses or the like.
Further, the other light source unit 4 is attached to the rear wall 3b of the AFS bracket 3 via, for example, a ball joint 4h so that the optical axis can be adjusted to match the optical axis of the one light source unit 4. ing.

According to the vehicular lamp 1 having such a configuration, the semiconductor light emitting element 4b of the light source unit 4 is driven to emit light by supplying power to the light source units 4 from the outside.
Light L emitted from the semiconductor light emitting element 4b of the light source unit 4 is reflected by the reflecting surface 4c, converged by the projection lens 4d, and irradiated forward through the front lens 5 in the light irradiation direction.
When the optical axis is swung left and right by the AFS function, the AFS bracket 3 is swung by driving means (not shown), so that the light axis of each light source unit 4 is swung left and right, and in a desired direction. Light is irradiated.

In such a vehicular lamp 1, heat is generated as the semiconductor light emitting element 4b emits light.
In general, it is known that the semiconductor light emitting element 4b has a negative characteristic with respect to temperature, that is, the light emission efficiency decreases as the temperature increases.
Therefore, in the vehicular lamp 1, heat from the semiconductor light emitting element 4b is conducted from the substrate 4a to the heat sink 4e, the small bracket 4g, and the AFS bracket 3.
Accordingly, heat is radiated from the heat sink 4e, the small bracket 4g, and the AFS bracket 3 into the housing 2, and an increase in temperature of the semiconductor light emitting element 4b can be suppressed by air circulation by natural convection.

However, in the vehicle lamp 1 described above, the light source unit 4 including the semiconductor light emitting element 4b is surrounded by the AFS bracket 3 except for the front surface, and is thermally blocked.
Therefore, the heat from the semiconductor light emitting element 4b is conducted from the substrate 4a and the heat sink 4e to the small bracket 4g by heat conduction, and is radiated into the air in the AFS bracket 3. Thereby, the temperature of the air in the AFS bracket 3 rises.

In particular, in the narrow gap between the small bracket 4g and the rear wall 3b of the AFS bracket 3, convection hardly occurs and the heat dissipation effect becomes extremely low.
Accordingly, the temperature in the gap increases at an accelerated rate, and heat dissipation from the small bracket 4g is hindered.
For this reason, there is a limit to the heat dissipation effect, and in some cases, the semiconductor light emitting element 4b emits light with the heat dissipation effect lowered. As a result, the light emission efficiency of the semiconductor light emitting element 4b is further lowered, and in some cases, adverse effects such as shortening the lifetime occur.

  In view of the above, the present invention provides a vehicular lamp that ensures air circulation by natural convection in an AFS bracket and effectively suppresses a temperature rise of a semiconductor light emitting element with a simple configuration. The purpose is that.

According to the present invention, the above object is achieved by an AFS bracket supported so as to be capable of changing the optical axis in a space formed by a housing whose front is open and a front lens covering the front of the housing, and the AFS bracket. Including at least one light source unit having a semiconductor light emitting element arranged to irradiate light forward through the front surface opened from the inside in the light irradiation direction,
Each light source unit has a semiconductor light-emitting element mounted on the substrate, an optical system that irradiates light from the semiconductor light-emitting element so as to converge forward in the light irradiation direction, and a heat sink that is in thermal contact with the substrate. And a small bracket disposed opposite to the rear wall of the AFS bracket so that the heat sink is fixed to the AFS bracket and / or held so that the optical axis can be adjusted.
The small bracket has an L-shaped cross section, and includes a rising portion and a base portion, and the rising portion of the small bracket is disposed at an interval without being in close contact with the AFS bracket,
The heat sink has a rear end fixed to the base portion of the small bracket, and is spaced from the AFS bracket.
In a region opposing at least a small bracket rear wall of the AFS bracket, heat radiation opening is provided, the air between the rear end of the AFS bracket and rising portion of the small bracket, for the heat radiation by natural convection This is achieved by a vehicular lamp characterized by having a flow path toward the opening .

  In the vehicular lamp according to the present invention, preferably, the heat radiation opening is configured by a plurality of slits extending in the vertical direction.

  The vehicular lamp according to the present invention is preferably provided with an air discharge opening at least in the upper region of the upper wall of the AFS bracket above the small bracket or the heat sink.

  The vehicular lamp according to the present invention is preferably provided with an air intake opening at a lower portion of the lower wall or the rear wall of the AFS bracket.

According to the above configuration, by supplying power from the outside to the semiconductor light emitting elements of each light source unit, the individual semiconductor light emitting elements are driven to emit light.
And the light radiate | emitted from each light source unit is irradiated toward the front through the said front lens.
In this case, heat generated in the semiconductor light emitting element of each light source unit is transmitted from the substrate to the heat sink, and further transmitted from the heat sink to the small bracket and the AFS bracket.
As a result, heat is radiated from the substrate, the small bracket and the AFS bracket to the air in the housing, and the heated air is circulated through the housing by convection to dissipate heat.

At that time, according to the feature of the present invention, the air in the gap between the small bracket and the rear wall of the AFS bracket is heated by the heat dissipation and provided on the rear wall of the AFS bracket when rising by natural convection. It passes through the opening for heat dissipation, escapes to the back side of the rear wall of the AFS bracket, and flows into the housing.
As a result, heated air does not accumulate in a narrow gap between the small bracket and the rear wall of the AFS bracket, and the temperature in the gap does not increase at an accelerated rate.

Therefore, the inside of the AFS bracket is effectively radiated, and the temperature rise of the semiconductor light emitting element is suppressed.
As a result, the luminous efficiency does not decrease due to the temperature rise of the individual semiconductor light emitting elements in each light source unit, and high luminance can be maintained. Further, the lifetime of these semiconductor light emitting elements is not shortened.

  In the case where the heat radiating opening is composed of a plurality of slits extending in the vertical direction, air that is going to rise by natural convection can easily pass through these slits. For this reason, the gap between the small bracket and the rear wall of the AFS bracket can be radiated more efficiently.

  In the case where an air discharge opening is provided at least above the small bracket or the heat sink on the upper wall of the AFS bracket, the air to be raised by heating passes through the air discharge opening and passes through the AFS bracket. Exit above. Therefore, the gap between the small bracket and the rear wall of the AFS bracket can be radiated more effectively.

When an air intake opening is provided in the lower wall or the lower wall of the AFS bracket, when the air between the small bracket and the rear wall of the AFS bracket is about to rise by heating, Air can be introduced from the air intake opening.
Therefore, the air in the gap can be more easily discharged to the outside through the heat radiation opening or the air discharge opening. Further, air having a relatively low temperature is introduced from the air intake opening, and the inside of the gap can be radiated more effectively.

Thus, according to the present invention, in a vehicle lamp having at least one light source unit including a semiconductor light emitting element, heat generated in the semiconductor light emitting element is conducted from the substrate to the small bracket and the AFS bracket via the heat sink. .
At this time, since the heat radiating opening is provided in the rear wall of the AFS bracket, the air in the gap between the small bracket and the rear wall of the AFS bracket passes through the heat radiating opening and the rear surface of the AFS bracket. Exit to the side.
Therefore, heat can be efficiently radiated in the gap, and a decrease in light emission efficiency of each semiconductor light emitting element of each light source unit due to a temperature rise can be suppressed, and shortening of the life of the semiconductor light emitting element can be avoided.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS.
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. As long as there is no description of the effect, it is not restricted to these aspects.

FIG. 1 shows the configuration of an embodiment of a vehicular lamp according to the present invention.
In FIG. 1, a vehicular lamp 10 is an LED headlamp for an automobile, and includes a resin casing 11 having an open front surface, and an AFS bracket 12 supported in the casing 2 so that the optical axis can be changed. The at least one (three in the illustrated example) light source unit 13 disposed in the AFS bracket 12 so as to emit light forward in the light irradiation direction and the front surface of the housing 11 are liquid-tight. The front lens 14 is attached to the front open end of the housing 11 so as to cover it.

The AFS bracket 12 includes a rear wall, left and right side walls, an upper wall, and a lower wall so that the front surface is open.
The AFS bracket 12 is supported in the casing 11 so as to be swingable around, for example, a vertical axis 12a.

Further, the AFS bracket 12 is configured to receive three light source units 13 as shown in FIG.
For this reason, the AFS bracket 12 is divided into three regions 12b1, 12b2, and 12b3 in which the rear wall 12b is aligned in the lateral direction and is displaced from each other in the front-rear direction.
Thereby, the optical unit 13 is arrange | positioned at the front side of each area | region 12b1, 12b2, 12b3, respectively.

The light source units 13 have the same configuration as each other and are configured as follows.
That is, the light source unit 13 includes at least one LED 13b mounted on the substrate 13a and an optical system for irradiating light from the LED 13b toward the front of the light irradiation direction (leftward in the figure). In this case, an ellipsoidal reflecting surface 13c and a projection lens 13d are included.

Furthermore, the light source unit 13 includes a heat sink 13e in order to dissipate heat generated by driving the LED 13b.
The heat sink 13e is attached to the front side of the upper surface with the lower surface of the substrate 13a in thermal contact with the heat conductive material 13f.
The rear end of the heat sink 13e is similarly attached to the small bracket 13g via the heat conductive material 13f.

Here, the small bracket 13g has an L-shaped cross section, and is arranged so that the rising portion faces the rear wall 12b of the AFS bracket 12 and the base portion extends forward.
At this time, the small bracket 13g is not closely attached to the AFS bracket 12 and is arranged at a slight interval so as not to interfere with the AFS bracket 12 during the optical axis adjustment described above in the region of the rising portion. Yes.
Further, the small bracket 13g is supported by the rear wall 12b of the AFS bracket 12 in the vicinity of the lower end of the rising portion.

Among the light source units 13, one light source unit 13 is fixedly attached to the rear wall 12 b of the AFS bracket 12 by a plurality of bosses or the like.
Further, the other light source unit 13 is attached to the rear wall 12b of the AFS bracket 12 via a ball joint 13h so that the optical axis can be adjusted to match the optical axis of the one light source unit 13. ing.

  The front lens 14 is made of a translucent resin material, and is attached to the housing 11 so as to liquid-tightly cover the front surface of the housing 11.

The above configuration is the same as that of the conventional vehicle headlamp 1 shown in FIG. 3, but the vehicle headlamp 10 according to the embodiment of the present invention is configured differently in the following points.
That is, the AFS bracket 12 includes a heat dissipating slit 12c in a region of the rear wall 12b facing the small bracket 13g, and an air discharge opening 12d in an upper region of the small bracket 13g on the upper wall. Yes.

  Further, the AFS bracket 12 includes air intake openings 12e and 12f, respectively, in the vicinity of the lower end of the rear wall 12b and in the front region of the lower wall.

As shown in FIG. 2, the heat dissipating slits 12 c are configured as a plurality of slits extending in the vertical direction, and are provided in the respective regions 12 b 1, 12 b 2 and 12 b 3 of the rear wall 12 b of the AFS bracket 12.
As a result, the air in the gap between the small bracket 13g and the rear wall 12b of the AFS bracket 12 does not decrease the strength of the rear wall 12b of the AFS bracket 12, as indicated by the arrow A in FIG. The AFS bracket 12 can be pulled out through the heat dissipation slit 12c.
At that time, the air in the gap tends to rise by natural convection. As a result, the rear surface of the AFS bracket 12 can be easily removed through the heat dissipating slit 12c extending in the vertical direction.

As shown in FIG. 2, the air discharge opening 12d is provided only in the central region 12b2 of the regions 12b1, 12b2, and 12b3 of the rear wall 12b of the AFS bracket 12, and is configured by one large opening. Has been.
As a result, the air between the small bracket 13g and the rear wall 12b of the AFS bracket 12 is allowed to escape above the AFS bracket 12 through the air discharge opening 12d as shown by an arrow B in FIG. It has become.

As shown in FIG. 2, the air intake opening 12e is provided in each of the regions 12b1, 12b2, and 12b3 of the rear wall 12b of the AFS bracket 12.
Thereby, between the small bracket 13g and the rear wall 12b of the AFS bracket 12, as indicated by arrows C and D in FIG. 1, from below and from the front, through these air intake openings 12e and 12f. Air having a relatively low temperature is introduced.

The vehicular lamp 10 according to the embodiment of the present invention is configured as described above. By supplying power to the light source units 13 from the outside, the individual LEDs 13b of the light source units 13 are driven to emit light. .
The light L emitted from the LED 13b of each light source unit 13 is reflected by the reflecting surface 13c, converged by the projection lens 13d, and irradiated forward through the front lens 14 in the light irradiation direction.
Further, when the optical axis is swung left and right by the AFS function, the AFS bracket 12 is swung by driving means (not shown). Thereby, the optical axis of each light source unit 13 is shaken to right and left, and light is irradiated in a desired direction.

In this case, the heat generated by the individual LEDs 13b of each light source unit 13 is transmitted from the substrate 13a to the heat sink 13e, and further conducted from the heat sink 13e to the small bracket 13g and the rear wall 12b of the AFS bracket 12.
Thereby, heat is radiated from the heat sink 13e, the small bracket 13g, and the AFS bracket 12 into the housing 11.

  At that time, air having a relatively high temperature in the gap between the small bracket 13g and the rear wall 12b of the AFS bracket 12 is provided on the rear wall 12b of the AFS bracket 12 as shown by an arrow A in FIG. The rear surface of the rear wall 12b of the AFS bracket 12 is removed through the heat dissipation slit 12c. Therefore, heated air does not accumulate in the gap and the temperature does not increase at an accelerated rate.

Air intake openings 12e and 12f are provided below the AFS bracket 12, and an air discharge opening 12d is provided above the AFS bracket 12, respectively. As a result, as shown by arrows B, C, and D in FIG. 1, an air flow passing through the gap is generated by natural convection.
Further, along with these air flows, an air flow that flows backward from the front side of the heat sink 13e is generated as indicated by an arrow E in FIG. Thereby, the heat dissipation effect of the heat sink 13e is further improved.

For this reason, the temperature rise of LED13b of each light source unit 13 can be suppressed.
Therefore, a decrease in light emission efficiency due to a temperature increase of each LED 13b of the light source unit 13 is suppressed, and a relatively high light emission efficiency can be maintained. Further, the life of the LED 13b is not shortened.

In the embodiment described above, the light source unit 13 includes the LED 13b as a semiconductor light emitting element. However, the semiconductor light emitting element is not limited to an LED, and may be another semiconductor light emitting element such as a semiconductor laser element.
In the above-described embodiment, the three light source units 13 are provided in the AFS bracket 12. However, the present invention is not limited to this, and one, two, or four or more light source units 13 may be provided. Good.

Further, in the above-described embodiment, the rear wall 12b of the AFS bracket 12 is provided with a plurality of heat radiation slits 12c extending in the vertical direction as heat radiation openings. It may be a plurality of slits extending in the lateral direction, or one or more large openings.
In the case of a plurality of slits extending in the lateral direction, the strength of the rear wall 12b of the AFS bracket 12 can be ensured, but it is somewhat resistant to the passage of air flow by natural convection, and the heat dissipation effect is slightly reduced. .
In the case of one or a plurality of large openings, the heat dissipation effect is excellent, but the strength of the rear wall 12b of the AFS bracket 12 is slightly reduced.
Therefore, as the heat radiation opening, the form of a plurality of heat radiation slits 12c extending in the vertical direction in the embodiment is desirable.

Further, in the above-described embodiment, in order to promote natural convection in the gap between the small bracket 13g and the rear wall 12b of the AFS bracket 12, air discharge openings 12c are provided above and below the AFS bracket 12, respectively. The air intake openings 12e and 12f are provided, but these may be omitted.
Even in this case, since the heat dissipating slit 12c is provided in the rear wall 12b of the AFS bracket 12, air having a relatively high temperature in the gap can be easily passed from the gap to the outside via the slit 12c. Can be discharged.

  Although the vehicular lamp 10 according to the present invention is configured as an automotive LED headlamp, the present invention is not limited thereto, and the present invention is applied to other types of vehicular lamps including auxiliary headlamps such as fog lamps and driving lamps. Is possible.

  As described above, according to the present invention, an extremely excellent vehicle that ensures air circulation by natural convection in the AFS bracket and effectively suppresses the temperature rise of the semiconductor light emitting device with a simple configuration. A lighting fixture could be provided.

It is a schematic sectional drawing which shows the structure of one Embodiment of the vehicle lamp by this invention. It is the schematic perspective view seen from the back of the AFS bracket in the vehicle lamp of FIG. It is a schematic sectional drawing which shows the structure of the conventional vehicle lamp.

Explanation of symbols

10 Lamp 11 Housing 12 AFS Bracket 12a Vertical Axis 12b Rear Wall 12c Heat Dissipation Slit (Heat Dissipation Opening)
12d Air discharge opening 12e, 12f Air intake opening 13 Light source unit 13a Substrate 13b LED (semiconductor light emitting element)
13c Reflective surface 13d Projection lens 13e Heat sink 13f Thermal conductive material 13g Small bracket 13h Ball joint 14 Front lens

Claims (4)

Light is irradiated through an AFS bracket that is supported so that the optical axis can be changed, and a front surface that is open from the inside of the AFS bracket, in a space formed by a housing that is open at the front and a front lens that covers the front of the housing. And at least one light source unit having a semiconductor light emitting element arranged to irradiate light forward in the direction,
Each light source unit has a semiconductor light-emitting element mounted on the substrate, an optical system that irradiates light from the semiconductor light-emitting element so as to converge forward in the light irradiation direction, and a heat sink that is in thermal contact with the substrate. And a small bracket disposed opposite to the rear wall of the AFS bracket so that the heat sink is fixed to the AFS bracket and / or held so that the optical axis can be adjusted.
The small bracket has an L-shaped cross section, and includes a rising portion and a base portion, and the rising portion of the small bracket is disposed at an interval without being in close contact with the AFS bracket,
The heat sink has a rear end fixed to the base portion of the small bracket, and is spaced from the AFS bracket.
In a region opposing at least a small bracket rear wall of the AFS bracket, heat radiation opening is provided, the air between the rear end of the AFS bracket and rising portion of the small bracket, for the heat radiation by natural convection A vehicular lamp characterized by having a flow path toward an opening .   The vehicular lamp according to claim 1, wherein the heat radiation opening includes a plurality of slits extending in a vertical direction.   The vehicular lamp according to claim 1, wherein an air discharge opening is provided at least in a region above the small bracket or the heat sink on the upper wall of the AFS bracket.   The vehicular lamp according to any one of claims 1 to 3, wherein an air intake opening is provided in a lower portion of the lower wall or the rear wall of the AFS bracket.

Images