JP2008059965A - Vehicle headlamp, lighting device and heat dissipation member thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiating member, a vehicle headlamp and a lighting device which have a high heat radiating performance and can be configured easily and at low cost.
To radiate an LED light source 11, a base portion 15a to which a substrate 11a of the LED light source is thermally connected and a plurality of thin plate-like heat radiating from the base portion substantially parallel to each other. It is the heat radiating member 15 for LED light source which consists of fin 15b, Comprising: The said base part 15a and each heat radiating fin 15b are comprised separately from each other, The said base part 15a is formed by forging or casting. The heat dissipating member 15 is configured such that the heat dissipating fins 15b are formed by bending a thin plate material.
[Selection] Figure 2

Description

  The present invention relates to a vehicle headlamp and an illumination device including an LED light source using an LED element as a light source, and a heat radiating member for radiating heat from the LED light source.

In recent years, with the increase in output and brightness of white LEDs, the use range of LED lamps has been expanded from display lamps to lighting devices, and vehicular headlamps that require a greater amount of light also in vehicle lamps. The use of white LEDs for lighting is being studied.
Such a white LED generally includes, for example, a blue LED chip (InGaN) and a phosphor that is excited by blue light such as YAG and converts the wavelength to yellow light. A pseudo white light is obtained by mixing colors of light.
In addition, white LEDs using a combination of a blue LED chip and green, red, or orange phosphors, and white LEDs using a combination of an ultraviolet LED chip and RGB phosphors have already been developed.

  In order to realize the amount of light and the light intensity required for the vehicle headlamp by using the white LED, it is necessary to use a high-power white LED and supply power of about 1 W to 5 W per LED chip. And since about 80 to 90% of input electric power is converted into heat, the LED chip is in a state with a very high heat density, and usually becomes a high temperature exceeding 200 ° C.

By the way, as for white LED, luminous efficiency falls with a temperature rise. Thereby, it has the characteristic that the lifetime will become short. For this reason, when using a high-power white LED, it is desirable to suppress the so-called junction temperature of the LED chip joint to a temperature of 100 ° C. or lower.
Therefore, when using a white LED as a light source for a vehicle headlamp, it is necessary to reduce the junction temperature and the phosphor temperature by diffusing generated heat and efficiently dissipating heat.

On the other hand, when used as a vehicle headlamp, the vehicle headlamp is installed in the engine room of an automobile. Is always at a high temperature of, for example, about 70 ° C to 90 ° C. Therefore, it is difficult to say that the environment is good because high-power white LEDs are used.
For this reason, a vehicle headlamp provided with a heat dissipation mechanism that can be used at a relatively low temperature even in an engine room is known.

Such a vehicle headlamp is configured, for example, as shown in FIG.
In FIG. 17, the vehicle headlamp 1 includes an LED light source 2, a reflecting surface 3, a projection lens 4, and a shutter 5.

The LED light source 2 includes at least one LED 2b mounted on the substrate 2a, and a rear region (right side in FIG. 17) of the substrate 2a is supported by the reflecting surface 3.
And each LED2b is arrange | positioned so that the optical axis may face diagonally upward toward the light emission direction back.
Further, the LED light source 2 is attached such that the substrate 2a is thermally connected to the heat radiating member 2c.

Here, as shown in FIG. 18, the heat radiating member 2c is configured as, for example, a heat sink having a large number of heat radiating fins 2d.
And such a heat radiating member 2c is normally formed by casting and extrusion molding, such as aluminum die casting.

The reflective surface 3 is composed of an elliptical reflective surface having a light emitting point vicinity of the LED light source 2 as a first focal point (rear focal point) F1 and a long axis extending substantially horizontally toward the front in the light irradiation direction, The inner surface is formed as a reflective surface.
Here, the elliptical reflecting surface includes not only a spheroid and an elliptic cylinder but also a free-form surface based on an ellipsoid.

The projection lens 4 is composed of a convex lens, and its focal point on the light source side (rear side) is disposed in the vicinity of the second focal position F2 of the reflecting surface 3.
Thereby, the projection lens 4 collects the reflected light traveling forward from the reflecting surface 3 in the light irradiation direction and projects the light forward in the light irradiation direction.

  The shutter 5 is made of a light shielding material, and an upper end 5a thereof is disposed in the vicinity of the second focal position F2 of the reflecting surface 3.

According to the vehicle headlamp 1 having such a configuration, each LED 2b is driven and emits light when power is supplied to the LED light source 2 from the outside.
The light emitted from each LED 2b is reflected by the reflecting surface 3, proceeds toward the second focal point F2 of the reflecting surface 3, is focused by the projection lens 4, and is irradiated forward in the light irradiation direction. .
At this time, a part of the light is blocked by the shutter 5, thereby forming a cut-off line and forming a light distribution pattern of a passing beam.

In this case, heat is generated as the individual LEDs 2b of the LED light source 2 emit light. This heat is transmitted from the LED light source 2 to the heat radiating member 2c, and is radiated from the heat radiating member 2c by the airflow flowing around. The heat radiating member 2c and the LED light source 2 are air-cooled.
Accordingly, each LED 2b of the LED light source 2 can be maintained at a relatively low temperature, for example, about 95 ° C., so that each LED 2b emits light with a relatively high light emission efficiency and emits high-luminance irradiation light forward. It has become.

In addition, a vehicle headlamp including a plurality of LED lamp units is also known, and is configured as shown in FIG. 19, for example.
In FIG. 19, a vehicle headlamp 6 has a resin housing 6a whose front surface is open, LED lamp units 7 and 8 provided in the housing 6a, and a front surface of the housing 6a. And a front lens 6b made of a translucent resin material attached to the body 6a.

The LED lamp unit 7 includes at least one LED 7b mounted on a mounting substrate 7a, and is supported with respect to the heat radiating member 7c so as to emit light forward.
Further, the LED lamp unit 7 includes a reflection surface 7d that reflects and focuses light emitted from the LEDs 7b forward, a projection lens 7e, and a shutter 7f.
Here, the reflection surface 7d, the projection lens 7e, and the shutter 7f are configured and arranged in the same manner as the reflection surface 3, the projection lens 4, and the shutter 5, respectively.

The LED lamp unit 8 includes at least one LED 8b mounted on the mounting substrate 8a, and is supported by the heat radiating member 8c so as to emit light forward.
Further, the LED lamp unit 8 includes a reflecting surface 8d that reflects and converges the light emitted from each LED 8b toward the front.
Here, the reflecting surface 8d is configured as a parabolic reflecting surface, and the LED 8b is disposed in the vicinity of the focal position.

  The heat dissipating members 7c and 8c have a heat sink structure having a large number of heat dissipating fins in the same manner as the heat dissipating member 2c described above.

According to the vehicle headlamp 6 having such a configuration, when the LED lamp units 7 and 8 are powered from the outside, the LEDs 7b and 8b of the LED lamp units 7 and 8 are driven to emit light.
And the light radiate | emitted from the said LED lamp units 7 and 8 is irradiated toward the front through the said front lens 6b.

In this case, heat is generated as the individual LEDs 7b and 8b in the LED lamp units 7 and 8 emit light, but this heat is transmitted from the LED lamp units 7 and 8 to the heat radiating members 7c and 8c. Heat is radiated from the members 7c and 8c to the air flow flowing through the housing 2, and the heat radiating members 7c and 8c and the LEDs 7b and 8b are cooled by air.
Accordingly, the individual LEDs 7b and 8b in the LED lamp units 7 and 8 can be maintained at a relatively low temperature, for example, about 95 ° C., so that each LED 7b and 8b emits light with a relatively high light emission efficiency, and high intensity irradiation light. Is emitted toward the front.

On the other hand, Patent Document 1 discloses a vehicular lamp in which a rear surface of a substrate on which an LED is mounted is configured as a heat radiating surface in a housing, and these heat radiating surfaces are provided with heat radiating fins.
According to the vehicular lamp having such a configuration, the heat generated by the LEDs is radiated from the heat radiation surface of the substrate into the housing via the heat radiation fins.

Patent Document 2 discloses a vehicular lamp in which a heat radiating portion provided in at least a part of a housing and an LED light source in the housing are thermally connected by a heat pipe.
According to the vehicular lamp having such a configuration, the heat generated by the LED is transmitted to the heat radiating portion via the heat pipe, and is radiated from the heat radiating portion to the outside.
JP 2005-150036 A JP 2006-164967 A

  By the way, in a vehicle headlamp using such an LED light source, the optical control unit can be miniaturized by using a plurality of LED lamp units 7, 8 as shown in FIG. 19, for example. . For this reason, compared with the vehicle lamp using the normal HID (High Intensity Discharge) light source etc., it can respond to the request | requirement of thickness reduction and various lamp design of a lamp. Moreover, since the infrared light component is not contained in the light from the white LED, heat transfer due to radiation is extremely small compared to other types of light sources. Therefore, the optical parts such as the reflecting surface (reflector) and the lens can be made of resin, and it is possible to easily reduce the weight and cost of the entire lamp.

However, the above-described lamp requires a heat dissipation structure for the LED light source.
Such a heat radiating structure is generally composed of a heat radiating member having a heat sink structure, and is small and light while maintaining high heat radiating performance, and is flexible enough to support various designs. It was necessary to satisfy the conditions of having a degree of freedom in design, dimensional accuracy sufficient to establish optical performance, and being able to be manufactured at low cost.

  On the other hand, the heat radiating member of the heat sink structure has heat radiating fins generally formed by casting or extrusion as described above.

  Therefore, for example, in the case of casting by aluminum die casting, it is possible to obtain a highly flexible shape at low cost. However, there are many problems in terms of shape due to problems of hot water flow and releasability based on the viscosity of the material (mainly aluminum) during casting. In particular, there are large restrictions on the length and thickness of the most important heat radiation fins that influence the heat radiation performance, and there are limits of about 40 to 50 mm in length and about 1.0 mm in thickness.

In addition, cast aluminum heat sinks have many restrictions on the type of aluminum material. For example, A1000 and A6000 materials with high thermal conductivity cannot be used, so there are many impurities and the thermal conductivity is less than half that of pure aluminum. A type of aluminum material called ADC12 is generally used. For this reason, the heat dissipation performance of the heat dissipation member is degraded.
In contrast, castable aluminum materials with high thermal conductivity have been developed recently, but such materials still have high material costs and high material viscosity, so there are significant constraints on the shape. Therefore, utilization as a heat radiating member is not progressing.

  Further, in the case of extrusion molding, the degree of freedom of shape is small. For example, in the case of heat radiating members 7c and 8c as shown in FIG. 19, a complicated structure for attaching the LED lamp units 7 and 8 as light sources is used. It is necessary to form the shape by post-processing such as cutting, which increases the manufacturing cost. Furthermore, as in the case of casting, there are restrictions on the length and thickness of the radiating fins, making it difficult to obtain the desired heat radiating performance and to reduce the weight in a limited space inside the housing. It was.

  In addition, there is a method of forming the heat radiating member by forging. However, as in the case of casting or extrusion molding, the heat radiation performance is the same as that of casting because there are restrictions on the material and the length and thickness of the heat radiating fins. It will be about.

  On the other hand, in the vehicular lamp according to Patent Document 1, similarly, a plurality of separate heat dissipating fins are attached to the back surface of the substrate on which the LEDs are mounted, so that heat generated by the LEDs is dissipated. However, the heat radiating fin is simply configured by arranging a plurality of plate-shaped heat radiating fins, and is similar to the heat radiating fin of the heat radiating member in the vehicle headlamps 1 and 6 described above. However, it is not configured to obtain as high a heat dissipation performance as possible.

  Moreover, in the vehicle lamp according to Patent Document 2, the heat generated from the LED is transferred to the heat dissipating part constituting at least a part of the housing via the heat pipe and dissipated to the outside. However, it is not configured to enhance the heat radiation performance of the heat radiating section itself.

  In view of the above, an object of the present invention is to provide a heat dissipation member, a vehicle headlamp, and a lighting device that have high heat dissipation performance and can be easily configured at low cost.

  According to the present invention, in order to dissipate heat from the LED light source, a base part to which a substrate of the LED light source is thermally connected and a plurality of thin plate-like members that protrude substantially parallel to each other from the base part are provided. A heat radiating member for an LED light source composed of a plurality of heat radiating fins, wherein the base portion and each heat radiating fin are configured separately from each other, and the base portion is formed by forging or casting, This is achieved by a heat dissipating member, wherein each heat dissipating fin is formed by bending a thin plate material.

  In the heat radiating member according to the present invention, preferably, the base portion and the heat radiating fins are joined to each other by brazing.

  In the heat radiating member according to the present invention, preferably, some of the radiating fins have different lengths from the other radiating fins.

  In the heat radiating member according to the present invention, preferably, some of the radiating fins have a thickness different from that of the other radiating fins.

  In the radiating member according to the present invention, preferably, some of the radiating fins have a different interval from the other radiating fins.

  In the heat dissipating member according to the present invention, preferably, the base portion includes a second heat dissipating fin formed integrally at the same time during forging or casting.

  In the heat radiating member according to the present invention, preferably, a part of the base part is inclined at an angle of 20 degrees or more with respect to the other part.

  In the heat dissipation member according to the present invention, preferably, the base portion is inclined at an angle of 20 degrees or more with respect to the optical axis of the optical system including the LED light source.

  In the heat dissipating member according to the present invention, preferably, each of the heat dissipating fins is made of aluminum or copper.

  In the heat dissipating member according to the present invention, preferably, the base portion has a heat dissipating structure using a phase change of liquid and gas.

  In addition, according to the second configuration of the present invention, the object is to provide at least one LED light source having at least one LED element arranged to irradiate light forward in the light irradiation direction, and the LED. In a vehicle headlamp including a heat radiating member made of a thermally conductive material to which a light source is thermally connected, the heat radiating member is a heat radiating member having any one of the above-described configurations. This is achieved by the vehicle headlamp.

  Further, according to the third configuration of the present invention, the object is to provide at least one LED light source having at least one LED element arranged to irradiate light in the light irradiation direction, and the LED light source. And a heat radiating member made of a thermally conductive material to be thermally connected, wherein the heat radiating member is a heat radiating member having any one of the above-described configurations. Achieved.

According to the above configuration, power is supplied from the outside to the LED light source in a state where the LED light source is thermally connected to the base portion of the heat radiating member. Driven and emits light. And it radiate | emits with respect to the light irradiation direction from a LED light source.
The heat generated in each LED of the LED light source is transmitted from the substrate of the LED light source to the heat radiating fin through the base portion of the heat radiating member, and is radiated from the heat radiating fin. Thereby, each LED of the LED light source is cooled, and the junction temperature and phosphor temperature of each LED are lowered. Thereby, the fall of the luminous efficiency of each LED can be suppressed.

  In this case, the base part of the heat radiating member and the heat radiating fins are formed separately from each other, preferably joined together by brazing, and the base part is formed by forging or casting. Thereby, about the said base part, a shape with a high freedom degree is obtained at low cost.

The heat dissipating fins are formed from a thin plate material by bending. As a result, the radiating fin is not limited in length and thickness as compared with the case of the radiating fin by conventional forging or casting, and the radiating fin having a desired length and thickness is easy. The heat dissipation efficiency is improved.
Thus, according to the heat radiating member by this invention, high heat dissipation performance can be provided. Further, the heat radiating member according to the present invention is reduced in weight, can be applied to various designs, can secure dimensional accuracy sufficient to achieve optical performance, and can be manufactured at low cost.

Furthermore, for example, by combining a base part with a common part and preparing a plurality of types of heat radiation fins with different fin shapes, by combining an appropriate type of heat radiation fin with the base part, a vehicle for different vehicle types A headlamp can be constructed.
Accordingly, the common parts can be expanded to various types of vehicles, so that the cost of the heat radiating member can be reduced.

  Among each radiation fin, some radiation fins have a length or thickness different from other radiation fins, or some radiation fins among each radiation fin have a different interval from other radiation fins. If it is included, for example, when it is accommodated in a space of a limited shape such as a lamp body of a vehicle headlamp, a high heat radiation performance can be obtained by effectively using this space. .

  In the case where the base portion is provided with a second heat radiation fin that is integrally formed at the same time during forging or casting, heat is also radiated through the second heat radiation fin provided on the base portion. As a result, the heat dissipation performance is further improved.

  When a part of the base part is inclined at an angle of 20 degrees or more with respect to other parts, or the base part is at an angle of 20 degrees or more with respect to the optical axis of the optical system including the LED light source. In the case of inclination, the gap between the radiating fins extends obliquely upward, and a chimney effect is obtained with respect to the natural convection of the air due to the radiating heat of the radiating fin. Performance will be improved.

  In the case where each of the heat radiating fins is made of aluminum or copper, each of the heat radiating fins has a high heat conduction effect, and the heat radiating performance is further improved.

  In the case where the base part has a heat dissipation structure using a phase change of liquid and gas, the base part is configured by using, for example, a vapor chamber, a heat pipe, etc. The heat dissipation performance will be further improved.

  Furthermore, according to the second and third configurations of the present invention, by including the above-described heat radiating member, a vehicle headlamp and a lighting device that have high heat radiating performance and can be reduced in size and weight as a whole can be configured. become.

  Therefore, for example, in order to obtain the same heat dissipation performance as the heat dissipation member shown in FIG. 17, the heat dissipation member can be reduced in weight to about 2/3 to 1/2. The device can be reduced in weight. In addition, with the same size heat radiating member, it is possible to obtain a heat radiating performance about 1.1 to 1.3 times that of the conventional one.

  Thus, according to the present invention, it is possible to provide a heat radiating member, a vehicle headlamp, and an illuminating device that have high heat radiating performance and can be configured easily and at low cost.

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 is particularly limited in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

[Example 1]
FIG. 1 shows a configuration of a first embodiment of a vehicle headlamp provided with a heat radiating member according to the present invention.
In FIG. 1, the vehicle headlamp 10 includes an LED light source 11, a reflecting surface 12, a projection lens 13, a shutter 14, and a heat dissipation member 15.

The LED light source 11 includes at least one LED 11b mounted on a substrate 11a, and a rear (right side in FIG. 1) region of the substrate 11a is supported with respect to the reflecting surface 12.
Each LED 11b is disposed at a predetermined inclination angle so that the substrate 11a is lowered rearward so that the optical axis thereof is obliquely upward toward the rear in the light emitting direction. This inclination angle is preferably selected to be an angle of 20 degrees or more.
Further, the LED light source 11 is attached such that the substrate 11 a is thermally connected to the heat radiating member 15.

The reflection surface 12 is composed of an elliptical reflection surface in which the vicinity of the light emitting point of the LED light source 11 is a first focal point (rear focal point) F1 and the major axis extends substantially horizontally toward the front in the light irradiation direction. The inner surface is formed as a reflective surface.
Here, the elliptical reflecting surface includes not only a spheroid and an elliptic cylinder but also a free-form surface based on an ellipsoid.

The projection lens 13 is composed of a convex lens, and its focal point on the light source side (rear side) is disposed in the vicinity of the second focal position F2 of the reflecting surface 12.
Thereby, the projection lens 13 collects the reflected light traveling forward from the reflecting surface 12 in the light irradiation direction and projects the light forward in the light irradiation direction.

  The shutter 14 is made of a light shielding material, and an upper end 14a thereof is disposed near the second focal position F2 of the reflective surface 12.

As shown in FIG. 2, the heat radiating member 15 includes a base portion 15a and a plurality of heat radiating fins 15b, and is similarly inclined according to the inclination of the substrate 11a of the LED light source 11 described above. Has been placed.
The base portion 15a and the radiation fins 15b are configured separately from each other, and are thermally connected to each other by brazing.

The base portion 15a is formed from a material having high thermal conductivity such as aluminum or copper, for example, by casting or forging.
Thereby, the base part 15a can be easily provided with a low-cost and highly flexible shape. In this case, since the radiation fin 15b is a separate body, the shape of the base portion 15a is restricted due to problems such as hot water flow and releasability based on the viscosity of the material at the time of casting. In addition, it is possible to use an A1000-based or A6000-based material that is aluminum having a high thermal conductivity. Therefore, high heat dissipation performance can be obtained.

The heat radiating fins 15b are formed by bending a thin plate material having high thermal conductivity such as aluminum or copper.
Accordingly, the length, thickness, height, and interval of the heat radiating fins 15b can be arbitrarily selected. Thereby, high heat dissipation performance can be easily obtained.

1 and 2, the heat dissipating fin 15b is divided into three parts with respect to the length direction (the direction of arrow A in FIG. 2), and the respective portions 15c, 15d, and 15e are respectively in the height direction (FIG. 2). Have different dimensions in the direction of arrow B).
In addition, the said radiation fin 15b may be formed so that the whole may have the same height as shown in FIG. 3 similarly to the heat radiating member in the conventional vehicle headlamp 1 shown in FIG.

According to the vehicle headlamp 10 having such a configuration, each LED 11b is driven to emit light when power is supplied to the LED light source 11 from the outside.
The light emitted from each LED 11b is reflected by the reflecting surface 12, travels toward the second focal point F2 of the reflecting surface 12, is focused by the projection lens 13, and is irradiated forward in the light irradiation direction.
At that time, a part of the light is blocked by the shutter 14 to form a cut-off line, and a light distribution pattern of a passing beam is formed.

  In this case, heat is generated with the light emission of the individual LEDs 11b of the LED light source 11, but this heat is transmitted from the LED light source 11 to the base portion 15a of the heat radiating member 15, and each heat release from the base portion 15a. The heat is transmitted to the fins 15b, and is radiated from these heat radiation fins 15b to the air flow flowing around, so that the heat radiation member 15 and the LED light source 11 are air-cooled. Thereby, since the junction temperature and fluorescent substance temperature of each LED11b fall, the fall of the luminous efficiency of each LED11b can be suppressed.

In that case, each radiation fin 15b of the said radiation member 15 is formed by the bending process of the thin plate material separately from the base part 15a. Thereby, desired length, thickness, height, and a space | interval can be provided, and higher heat dissipation performance will be provided.
Further, the heat radiation fins 15b are arranged to be inclined corresponding to the inclination of the substrate 11a of the LED light source 11. For this reason, the duct defined between the radiation fins 15b is similarly inclined and arranged. Thereby, when the air heated by the radiant heat from the radiation fin 15b flows in each duct by natural convection, a high heat radiation performance is obtained by the chimney effect.
Therefore, each LED 11b of the LED light source 11 can be reliably maintained at a relatively low temperature, for example, about 95 ° C. Thereby, each LED11b can light-emit with high luminous efficiency, and can radiate | emit high-intensity irradiation light toward the light irradiation direction front.

[Example 2]
FIG. 4 shows a configuration of a second embodiment of a vehicle headlamp provided with a heat radiating member according to the present invention.
In FIG. 4, a vehicle headlamp 20 includes a resin-made casing 21 whose front surface is open, LED lamp units 22 and 23 serving as LED light sources provided in the casing 21, and a front surface of the casing 21. A front lens 24 made of a translucent resin material attached to the housing 21 so as to cover it and heat radiating members 25 and 26 are included.

The LED lamp unit 22 includes at least one LED 22b mounted on a mounting substrate 22a, and is supported with respect to the heat dissipation member 25 so as to emit light forward.
Further, the LED lamp unit 22 includes a reflection surface 22d that reflects and focuses light emitted from the LEDs 22b forward, a projection lens 22e, and a shutter 22f.
Here, the reflection surface 22d, the projection lens 22e, and the shutter 22f are configured and arranged in the same manner as the reflection surface 12, the projection lens 13, and the shutter 14, respectively.

The LED lamp unit 23 includes at least one LED 22b mounted on the mounting substrate 23a, and is supported by the heat radiating member 26 so as to emit light forward.
Further, the LED lamp unit 23 includes a reflecting surface 23d that reflects and converges the light emitted from the LEDs 23b toward the front.
Here, the reflection surface 23d is configured as a parabolic reflection surface, and the LED 23b is disposed in the vicinity of the focal position.

  The heat radiating members 25 and 26 are formed separately from the base portions 25a and 26a and the base portions 25a and 26a, respectively, as shown in FIG. The plurality of heat radiation fins 25b and 26b are thermally connected to the base portions 25a and 26a by brazing.

In this case as well, the base portions 25a and 26a are formed from a material having high thermal conductivity such as aluminum or copper, for example, by casting or forging, in the same manner as the heat radiating members 15a and 16a described above. 25b and 26b are formed by bending from a thin plate material having high thermal conductivity such as aluminum or copper.
Therefore, the base parts 25a and 26a are easily provided with a shape having a high degree of freedom at a low cost. This also provides high heat dissipation performance. Further, the length, thickness, and interval of the heat radiation fins 25b and 26b can be arbitrarily selected. Thereby, high heat dissipation performance can be easily obtained.

In this case, as shown in FIGS. 4 and 5, the heat radiation fins 25b and 26b are divided into two parts in the length direction (the direction of arrow A in FIG. 5), and the respective parts 25c, 25d and 26c, 26d has different dimensions in the height direction (arrow B direction in FIG. 5).
Incidentally, the heat radiating fins 25b and 26b may be formed so as to have the same height as shown in FIG. 6 as in the case of the heat radiating member in the conventional vehicle headlamp 1 shown in FIG. Good.
Further, the base portion 26a of the heat radiating member 26 is provided with second heat radiating fins 26e on the back side of the portion to which the mounting substrate 23a of the LED lamp unit 23 is attached.
The second heat radiating fins 26e are formed at the same time when the base portion 26a is manufactured by casting or forging.

According to the vehicle headlamp 20 having such a configuration, when the LED lamp units 22 and 23 are supplied with power from the outside, the LEDs 22b and 23b of the LED lamp units 22 and 23 are driven to emit light.
Light emitted from the LED lamp units 22 and 23 is irradiated forward in the light irradiation direction through the front lens 24.

In this case, heat is generated as the individual LEDs 22b and 23b in the LED lamp units 22 and 23 emit light. This heat is generated from the LED lamp units 22 and 23 to the base portions 25a and 25a of the heat radiation members 25 and 26, respectively. 26a, transmitted from the base portions 25a, 26a to the radiation fins 25b, 26b, 26e, radiated from the radiation fins 25b, 26b to the air flow flowing around, and by the chimney effect of natural convection of air The heat dissipating members 25 and 26 and the LEDs 22b and 23b are air-cooled.
Thereby, the junction temperature and phosphor temperature of each LED22b, 23b in LED lamp unit 22,23 fall. Thereby, the fall of the luminous efficiency of each LED22b and 23b can be suppressed.

At that time, the individual heat radiation fins 25b, 26b of the heat radiation members 25, 26 are formed by bending a thin plate material separately from the base portions 25a, 26a. For this reason, it will be provided with desired length, height, thickness, and space | interval, and it has higher heat dissipation performance.
For example, the thickness of the heat radiation fins 25b and 26b can be reduced to, for example, about 0.1 mm. Thereby, the number of the radiation fins 25b and 26b can be increased, and the heat radiation performance can be easily improved.

Furthermore, the radiation fins 25b and 26b are formed by folding. For this reason, every other tip at the tip opposite to the base portions 25a and 26a, a bridge portion for connecting the heat radiation fins 25b and 26b is formed, and the surface area of the heat radiation fins 25b and 26b is increased. By further increasing, the heat dissipation performance can be enhanced.
Moreover, according to the shape of the housing | casing 21 of the vehicle headlamp 20, the radiation fins 25b and 26b can be set to partially different height. For this reason, a freedom degree becomes large regarding the layout of the radiation fins 25b and 26b in the housing | casing 21. FIG.
Therefore, the LEDs 22b and 23b of the LED lamp units 22 and 23 can be reliably maintained at a relatively low temperature, for example, about 95 ° C. Thereby, each LED22b and 23b can light-emit with high luminous efficiency, and can radiate | emit high-intensity irradiation light toward the front of a light irradiation direction.

In the vehicle headlamp 20 described above, with respect to the heat radiating member 26 attached to the lower LED lamp unit 23, the base portion 26a is fixed and held inclined with respect to the horizontal direction, that is, the optical axis direction of the vehicle headlamp. As a result, the air passage by the heat radiating fins 26b is inclined by 20 degrees or more from the horizontal direction, and in the illustrated case, extends substantially in the vertical direction. As a result, as indicated by an arrow C in FIG. 5, a chimney effect by natural convection occurs, and the heat dissipation performance is further improved.
The heat dissipating member 26 further includes second heat dissipating fins 26e on the surface of the base portion 26a. The radiating fins 26e are formed at the same time when the base portion 26a is formed by casting or forging.
Thereby, the heat dissipation performance by the heat radiating member 26 is further improved.

Furthermore, in the vehicle headlamp 20 described above, since the heat radiation fins 25b and 26b are divided into two parts and arranged in a step shape, the air from the heat radiation fins 25b and 26b is shown in the step region. As indicated by an arrow at 5, it is discharged to the outside step by step.
Accordingly, the entire base portions 25a and 26a of the heat radiating members 25 and 26 are radiated more uniformly, and the temperature distribution in the entire base portions 25a and 26a becomes more uniform.

7 and 8 show the configuration of the first modification of the heat dissipating members 25 and 26 in the vehicle headlamp 20 described above.
In FIG. 7, the heat dissipating members 25 and 26 have heat dissipating fins 25b and 26b divided into two in the length direction, and each of the divided parts is half of the distance between the individual heat dissipating fins 25b and 26b in the lateral direction. They are offset by a certain amount.
According to the heat radiating members 25 and 26 having such a configuration, the air flowing between the heat radiating fins 25b and 26b is generally a so-called laminar flow due to the chimney effect as shown in FIG. As described above, the upper and lower divided parts are shifted from each other. For this reason, as shown in FIG. 9B, turbulence occurs near the boundary between the upper and lower divided portions.
Thereby, the air which contacts the surface of the radiation fins 25b and 26b will increase, and the heat radiation performance will be further improved.

FIG. 10 shows a configuration of a first modification of the heat dissipation members 25 and 26 in the vehicle headlamp 20 described above.
In FIG. 10, the heat dissipating members 25 and 26 have heat dissipating fins 25b and 26b which are divided into two in the length direction, and the upper part of the heat dissipating members is inclined leftward at a predetermined inclination angle obliquely upward. So that it is arranged. In this case, the inclination angle is preferably selected to be an angle of 20 degrees or more.

According to the heat radiating members 25 and 26 having such a configuration, the air flowing between the heat radiating fins 25b and 26b generally flows upward due to the chimney effect as shown in FIG. However, it will be induced | guided | derived to a horizontal direction according to the inclination of the upper part of the radiation fin 25b, 26b.
Thereby, the heat dissipation direction of the heat radiating members 25 and 26 can be controlled. Thereby, when a plurality of LED light sources, which are heat generation sources, are arranged, mutual thermal influences of the LED light sources can be suppressed.

FIG.11 and FIG.12 has shown the modification of the heat radiating member 26 for the LED lamp unit 23 in the vehicle headlamp 20 shown in FIG.
11 and 12, the heat dissipating member 26 has a heat dissipating fin 26b divided into three parts in the length direction, and each part has a different size in the height direction, thereby providing a stepped outer shape. Yes.

  By providing such a stepped outer shape, the heat radiating member 26 has heat radiating fins 26b having as large a heat radiating surface as possible in a relatively narrow space below the heat radiating member 25 of the LED lamp unit 22. Higher heat dissipation performance can be obtained.

In the vehicle headlamps 10 and 20 described above, the base portions 15a, 25a, and 26a of the heat dissipation members 15, 25, and 26 are arranged so as to be inclined with respect to the horizontal direction. The duct defined between 25b and 26b is inclined and arranged. Thereby, the chimney effect by the natural convection of the air by this inclination arises, and the thermal radiation performance improves.
When the heat radiation performance due to such a duct inclination was experimented in a case where the inclination angle of the base portion 15a of the heat radiating member 15 according to FIG. 3 was variously changed by simulation, results as shown in FIG. 13 were obtained.
That is, when the inclination angle of the base part is changed to 0 degrees, 20 degrees, 45 degrees, and 90 degrees, the temperature of the air directly below the LED light source, above the base parts 15a, the heat radiation fins 15b, and the heat radiation member 15 is As indicated by reference numerals T1, T2, T3, and T4 in FIG. 13, it was found that the greater the inclination angle, the greater the cooling effect by the heat dissipation performance.
That is, it was confirmed that the heat radiation performance was improved by about 3% at an inclination angle of 20 degrees, about 5% at an inclination angle of 45 degrees, and about 10% at an inclination angle of 90 degrees.

FIG. 14 shows a modification of the heat dissipation member shown in FIG.
In FIG. 14, the heat radiating members 25 and 26 are divided into two with respect to the length direction of the heat radiating fins 25b and 26b, and the respective divided portions are shifted from each other by the distance between the individual heat radiating fins 25b and 26b. Has been placed.
According to the heat radiating members 25 and 26 having such a configuration, the air flowing between the heat radiating fins 25b and 26b is below the duct between the heat radiating fins 25b and 26b near the boundary between the upper and lower divided portions. The air flowing through the leftmost duct is released to the outside. Further, the air flowing through the uppermost rightmost duct is taken in from the outside.
Thus, by separating and guiding the air flowing through the upper part duct and the lower part duct, the influence of the temperature of the air flowing through the lower part duct on the heat radiation performance of the upper part duct can be suppressed.

FIG. 15 shows a modification of the heat dissipation member shown in FIG.
In FIG. 15, the heat radiating members 25 and 26 have their heat radiating fins 25b and 26b divided into three parts with respect to the length direction, and the center part of each divided part is inclined downward to the left. It arrange | positions so that it may remove | deviate completely from the upper end of a lower part.
According to the heat radiating members 25 and 26 having such a configuration, the air flowing between the heat radiating fins 25b and 26b does not enter the central and upper part of the duct from the upper part of the duct. In addition, relatively cool air outside can be introduced into the duct in the central portion.
Thus, by separating and guiding the air flowing through the upper part duct and the lower part duct, the influence of the temperature of the air flowing through the lower part duct on the heat radiation performance of the upper part duct can be suppressed.

FIG. 16 shows a modification of the heat dissipation member shown in FIG.
In FIG. 16, the heat radiating members 25 and 26 have their heat radiating fins 25b and 26b divided into three parts with respect to the length direction, and the central part of each of the divided parts is inclined leftward toward the upper side. For this reason, it arrange | positions so that it may remove | deviate completely from the lower end of an upper part.
According to the heat radiating members 25 and 26 having such a configuration, the air flowing between the heat radiating fins 25b and 26b is guided to the left by the air flow discharged from the upper end of the duct in the lower part through the duct in the central part. Is done. For this reason, it does not enter into the duct of the upper part, and external relatively low temperature air can be introduced into the duct of the upper part.
Thus, by separating and guiding the air flowing through the upper part duct and the lower part duct, the influence of the temperature of the air flowing through the lower part duct on the heat radiation performance of the upper part duct can be suppressed.

In the above-described embodiment, the vehicle headlamps 10 and 20 using the LED light source 11 or the LED lamp units 22 and 23 have been described. However, the present invention is not limited to this, and other LED lamps using the LED light source, particularly lighting devices. It is clear that the present invention can be applied to a heat dissipation member that is thermally connected to the LED light source.
Moreover, in the vehicle headlamp 20 shown in FIG. 4, although the heat radiating members 25 and 26 are provided with respect to the LED lamp units 22 and 23, respectively, it is not restricted to this, Both LED lamp units 22, One common heat radiating member may be provided for 23.

  Further, in the above-described embodiment, the base portions 15a, 25a, and 26a of the heat dissipation members 15, 25, and 26 are made of a material having high thermal conductivity such as aluminum and copper, but are not limited thereto. Instead, a heat dissipation structure using a phase change between liquid and gas, for example, a heat pipe or a vapor chamber may be provided.

  The heat dissipating members 15, 25 and 26 according to the present invention dissipate the LED light sources of the vehicle headlamps 10 and 20, respectively. However, the present invention is not limited to this, and other types of vehicle lamps and LED lamps, for example, It can also be used to dissipate the LED light source for the lighting device.

  Thus, according to the present invention, it is possible to provide an extremely excellent heat radiating member, vehicle headlamp, and lighting device that have high heat radiating performance and can be easily configured at low cost. .

It is a schematic sectional drawing which shows the structure of 1st embodiment of the vehicle headlamp by this invention. It is a schematic perspective view which shows the heat radiating member in the vehicle headlamp of FIG. It is a schematic perspective view which shows the modification of the heat radiating member of FIG. It is a schematic sectional drawing which shows the structure of 2nd embodiment of the vehicle headlamp by this invention. It is a schematic perspective view which shows the heat radiating member in the vehicle headlamp of FIG. It is a schematic perspective view which shows the modification of the heat radiating member of FIG. It is a schematic perspective view which shows the modification of the heat radiating member of FIG. It is a top view which shows the heat radiating member of FIG. It is explanatory drawing which shows the airflow which flows through the inside of the duct in the heat radiating member of FIG. It is a schematic perspective view which shows the modification of the heat radiating member of FIG. It is a schematic side view which shows the modification of the downward heat radiating member in the vehicle headlamp of FIG. It is a schematic perspective view which shows the heat radiating member of FIG. It is a graph which shows the simulation result of the inclination angle in the heat radiating member of FIG. 3, and the temperature of each part. It is a schematic sectional drawing which shows the modification of the radiation fin of the thermal radiation member of FIG. It is a schematic sectional drawing which shows the modification of the radiation fin of the thermal radiation member of FIG. It is a schematic sectional drawing which shows the modification of the radiation fin of the thermal radiation member of FIG. It is a schematic sectional drawing which shows the structure of an example of the vehicle headlamp by the conventional LED. It is a schematic perspective view which shows the heat radiating member in the vehicle headlamp of FIG. It is a schematic sectional drawing which shows the structure of the other example of the vehicle headlamp by the conventional LED.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20 Vehicle headlamp 11 LED light source 12 Reflecting surface 13 Projection lens 14 Shutter 15 Heat radiating member 15a Base part 15b Radiation fin 21 Case 22, 23 LED lamp unit (LED light source)
24 Front lens 25, 26 Radiation member 25a, 26a Base part 25b, 26b Radiation fin 26e Second radiation fin

Claims (12)

In order to radiate the LED light source, an LED light source comprising a base portion to which a substrate of the LED light source is thermally connected and a plurality of thin plate-like heat radiating fins protruding substantially parallel to each other from the base portion. A heat dissipating member,
The base part and each radiating fin are configured separately from each other,
The base part is formed by forging or casting,
Each of the heat dissipating fins is formed by bending a thin plate material.   The heat radiating member according to claim 1, wherein the base portion and each heat radiating fin are joined to each other by brazing.   3. The heat radiating member according to claim 1, wherein a part of the heat radiating fins has a length different from that of the other heat radiating fins.   3. The heat radiating member according to claim 1, wherein a part of the heat radiating fins has a thickness different from that of the other heat radiating fins.   3. The heat radiating member according to claim 1, wherein some of the heat radiating fins have an interval different from that of the other heat radiating fins.   The heat radiating member according to claim 1, wherein the base portion includes a second heat radiating fin that is integrally formed at the same time during forging or casting.   The heat radiation member according to any one of claims 1 to 6, wherein a part of the base part is inclined at an angle of 20 degrees or more with respect to another part.   The heat radiating member according to claim 1, wherein the base portion is inclined at an angle of 20 degrees or more with respect to an optical axis of an optical system including an LED light source.   9. The heat radiating member according to claim 1, wherein each of the heat radiating fins is made of aluminum or copper.   The heat radiating member according to claim 1, wherein the base portion has a heat radiating structure using a phase change between a liquid and a gas. At least one LED light source having at least one LED element arranged to irradiate light forward in the light irradiation direction, and a heat dissipation member made of a thermally conductive material to which the LED light source is thermally connected; In vehicle headlamps, including
A vehicle headlamp, wherein the heat dissipating member is a heat dissipating member according to any one of claims 1 to 10.   At least one LED light source having at least one LED element arranged to irradiate light toward the light irradiation direction, a heat radiating member made of a thermally conductive material to which the LED light source is thermally connected, and The illuminating device comprising: the radiating device according to any one of claims 1 to 10, wherein the radiating member is a radiating member according to any one of claims 1 to 10.

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