阅读说明：本技术 车辆用灯具 (Vehicle lamp ) 是由 竹内泰斗 于 2019-07-30 设计创作，主要内容包括：车辆用灯具具备：散热器(12)；配置于散热器(12)的发光元件；以及配置于发光元件的上方且使从发光元件射出的射出光反射至前方的反射体。散热器(12)具备将发光元件配置于台座部(21)的基体部(22)；以及配置于基体部(22)的背面侧且对由发光元件产生的热进行散热的翅片部(23)。基体部(22)的背面相对低于台座部(21)倾斜。就散热器(12)的基体部(22)的厚度而言,发光元件的下方侧比基体部(22)的后方更厚。(A vehicle lamp includes: a heat sink (12); a light emitting element disposed on the heat sink (12); and a reflector disposed above the light emitting element and reflecting light emitted from the light emitting element to the front. The heat sink (12) is provided with a base portion (22) for disposing the light-emitting element on the pedestal portion (21); and a fin section (23) which is disposed on the rear surface side of the base section (22) and which dissipates heat generated by the light-emitting element. The back surface of the base portion (22) is inclined lower than the pedestal portion (21). The thickness of the base portion (22) of the heat sink (12) is greater on the lower side of the light-emitting element than on the rear side of the base portion (22).)

1. A vehicle lamp is characterized by comprising:

a heat sink;

a light emitting element disposed on the heat sink; and

a reflector disposed above the light emitting element and reflecting light emitted from the light emitting element to the front,

the radiator includes:

a base portion for disposing the light emitting element on a pedestal portion of an upper surface of the heat sink; and

a fin portion disposed on the rear surface side of the base portion and configured to dissipate heat generated by the light emitting element,

the back surface of the base portion is inclined with respect to the pedestal portion.

2. The vehicular lamp according to claim 1,

the thickness of the base portion of the heat sink is larger on the lower side of the light emitting element than on the rear side of the base portion.

3. The vehicular lamp according to claim 1,

the heat sink is further provided with heat transfer ribs,

the heat transfer rib is disposed on the same surface side as a surface on which the light emitting element is disposed in a direction from the center of the light emitting element toward the outside, and transfers heat generated by the light emitting element.

4. The vehicular lamp according to claim 1,

the fin part is provided with a heat radiation fin,

the heat radiating fins are formed by arranging plate-shaped plate fins at certain intervals along the horizontal direction,

as for the above-mentioned heat sink, it is preferable that,

the rear surface of the base portion extends in the front-rear direction below the light emitting element,

the front end of the heat radiating fin is inclined along the back surface of the base portion.

Technical Field

The present disclosure relates to a vehicle lamp.

Background

Conventionally, a vehicle lamp using a light emitting element as a light source is used as a headlamp or an auxiliary headlamp (see, for example, patent document 1). Such a vehicle lamp includes a light emitting element and a reflector, and the light emitting element is mounted on a heat sink. In the vehicle lamp, heat generated by lighting the light emitting element is dissipated by the heat sink, thereby suppressing a characteristic change caused by the heat of the light emitting element. The radiator has larger size and higher radiating effect, so the radiator is formed to be larger and has a wall thickness shape as a whole.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2008-288113

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional technology as described in patent document 1, the size of the radiator becomes a factor of increasing the weight, and the shape of the radiator is a convection stagnation from below. Therefore, the conventional technology described in patent document 1 cannot achieve weight reduction and cannot improve heat dissipation performance.

The present disclosure is made in view of such circumstances, and is directed to a heat radiating device that can be made light and improve heat radiation performance.

Means for solving the problems

A vehicle lamp according to an aspect of the present disclosure includes: a heat sink; a light emitting element disposed on the heat sink; and a reflector disposed above the light emitting element and reflecting light emitted from the light emitting element to the front, the heat sink including: a base portion for disposing the light emitting element on a pedestal portion of an upper surface of the heat sink; and a fin portion that is disposed on a back surface side of the base portion and radiates heat generated by the light emitting element, wherein the back surface of the base portion is inclined with respect to the pedestal portion.

ADVANTAGEOUS EFFECTS OF INVENTION

According to an aspect of the present disclosure, the weight can be reduced and the heat dissipation performance can be improved.

Drawings

Fig. 1 is a diagram showing a configuration example of a vehicle lamp to which an embodiment of the present disclosure is applied.

Fig. 2 is a front view of the heat sink 12 to which the embodiment of the present disclosure is applied.

Fig. 3 is a plan view of the heat sink 12 to which the embodiment of the present disclosure is applied.

Fig. 4 is a right side view of the heat sink 12 to which the embodiment of the present disclosure is applied.

Fig. 5 is a sectional view a-a in fig. 2 of the heat sink 12 to which the embodiment of the present disclosure is applied.

Fig. 6 is a B-B sectional view in fig. 2 of the heat sink 12 to which the embodiment of the present disclosure is applied.

Fig. 7 is a front view of a conventional heat sink 112.

Fig. 8 is a plan view of a conventional heat sink 112.

Fig. 9 is a right side view of the conventional heat sink 112.

Fig. 10 is a sectional view a-a of the conventional heat sink 112 in fig. 7.

Fig. 11 is a cross-sectional view B-B of the conventional heat sink 112 in fig. 7.

Detailed Description

Hereinafter, embodiments of a vehicle lamp to which the present disclosure is applied will be described in detail with reference to the drawings. The present disclosure is not limited to the embodiment.

(simplified Structure)

Fig. 1 is a diagram showing a configuration example of a vehicle lamp to which an embodiment of the present disclosure is applied. Fig. 2 is a front view of the heat sink 12 to which the embodiment of the present disclosure is applied. Fig. 3 is a plan view of the heat sink 12 to which the embodiment of the present disclosure is applied. Fig. 4 is a right side view of the heat sink 12 to which the embodiment of the present disclosure is applied. Fig. 5 is a sectional view a-a in fig. 2 of the heat sink 12 to which the embodiment of the present disclosure is applied. Fig. 6 is a B-B sectional view in fig. 2 of the heat sink 12 to which the embodiment of the present disclosure is applied. Fig. 1 is a view showing the respective structures of the vehicle lamp in a simple cross section and omitting a part of the lens holder 16 for easy understanding of the structures.

A vehicle lamp is used to constitute a headlamp of a vehicle such as an automobile. The headlamps are respectively mounted on the left and right sides of the front portion of the vehicle, and a vehicle lamp is provided in a lamp chamber formed by a lamp housing whose open front end is covered by an external lens. The vehicle lamp is provided in the lamp chamber via the vertical optical axis adjusting mechanism and the horizontal optical axis adjusting mechanism, and appropriately irradiates the front of the vehicle. The vehicle lamp includes a light source 11, a radiator 12, a reflector 13, a cover unit 14, a projection lens 15, a lens holder 16, and a cooling fan unit 17, and constitutes a projection-type headlamp unit. The vehicle lamp can switch the light distribution pattern by using the shade unit 14.

The light source 11 is configured by mounting a light emitting element 11b as a light emitting diode on a substrate 11 a. The substrate 11a is disposed on the pedestal portion 21 of the upper surface 12a of the heat sink 12, and a power supply holder is attached from above, and terminals of the substrate 11a are connected to terminals provided on the power supply holder and fixed to the upper surface 12 a. Therefore, the heat sink 12 functions as a stage on which the light source 11 is provided. That is, the light emitting element 11b is disposed on the heat sink 12. Therefore, the light source 11 is supplied with power from the lighting control circuit to the light emitting element 11b via the power supply socket and appropriately lighted.

The heat sink 12 is a heat radiating member that radiates heat generated by the light source 11 provided on the upper surface 12a to the outside, and includes a base portion 22 and a fin portion 23, and is molded by die casting, for example. The detailed configuration will be described later, but the base portion 22 is a member in which the light emitting element 11b is disposed on the pedestal portion 21 of the upper surface 12a of the heat sink 12. The light emitting element 11b disposed on the base 21 is mounted with a power supply socket, not shown, by using screw holes 12b and 12c and by using a screw upper side. The fin portion 23 is disposed on the back side of the base portion 22, and dissipates heat generated by the light emitting element 11b, as will be described in detail later. The heat sink 12 is held by the lamp housing via a bracket, not shown, so as to be vertically and horizontally adjustable. The heat sink 12 includes a first light-shielding sheet 27. The first light-shielding sheet 27 is formed such that an end portion of the front side of the upper surface 12a partially protrudes and extends in the width direction. The first light-shielding sheet 27 shields direct light from the light-emitting element 11b by an end portion located on the front side of the heat sink 12.

The reflector 13 is disposed above the light emitting element 11b, and reflects the light emitted from the light emitting element 11b to the projection lens 15 in front. The reflector 13 is positioned and fixed to the heat sink 12 by being screwed into the screw holes 25a provided in the heat transfer ribs 25. The front direction means the same direction as the front direction of the vehicle. The same meaning will be used in the following description.

The projection lens 15 projects the outgoing light reflected by the reflector 13 to the front of the vehicle, and forms a light distribution pattern in cooperation with the reflector 13. The projection lens 15 is positioned with respect to the light source 11 and the reflector 13 by being supported by the lens holder 16. The shade unit 14 switches the light distribution of the projection light projected by the projection lens 15 to a low beam light distribution pattern and a high beam light distribution pattern. The globe unit 14 includes: a carrier plate 31; a shade 32 that is displaced in position for switching light distribution; a solenoid 33 as a driving unit for displacing the position of the globe 32; and a torsion coil spring 54 for transmitting the operation of the solenoid 33 to the globe 32. The carriage plate 31 rotatably supports the rotary shaft 37. The shade 32 shields a part of the emitted light emitted from the light source 11 and forms a cutoff line of the light distribution pattern. The globe 32 is configured such that a first thin plate-shaped globe cover 42 and a second thin plate-shaped globe cover 43 are attached to the rotating base 41. The rotation base 41 is provided with a bearing piece 44, and the rotation shaft 37 is inserted into the shaft hole. The rotation base 41 includes a first positioning piece 46, a second positioning piece 47, and a transmission piece 48. The transmission piece 48 is formed by bending a portion cut in a U shape at the center of the rotation base 41 in the width direction. The opening 49 is formed at a position where the transmitting piece 48 before being bent is cut into a U shape at the center of the rotation base 41 in the width direction.

The first lamp cover portion 42 is mounted on the upper portion of the rotating base portion 41. The second cover part 43 is attached to the first cover part 42 with a certain interval from the first cover part 42. The shade 32 includes a second light shielding sheet 28 formed above the opening 49 so as to project toward the light source 11. The second shade 28 is formed by bending the lower end of the first shade portion 42. The second light-shielding sheet 28 passes through the rotating shaft 37 and the opening 49 from the upper portion of the reflector 13 and is positioned on the path to the projection lens 15. The solenoid 33 includes a coil 51, a yoke 52 having the coil 51 built therein, and a plunger 53 advancing and retreating from the yoke 52, and the yoke 52 is configured to be fixed to the front surface of the carriage plate 31. One end of a torsion coil spring 54 is attached to a distal end portion of the plunger 53. The other end of the torsion coil spring 54 is attached to the transmission plate 48. Therefore, the plunger 53 that advances and retracts by the energization and non-energization of the coil 51 displaces the position of the globe 32.

The cooling fan unit 17 is provided below the heat sink 12, and is configured such that a cooling fan is rotatably provided in a rectangular parallelepiped housing. When the light source 11 emits light, the cooling fan is driven by the motor to rotate, and convection F1 is generated, whereby the cooling fan unit 17 cools the lower side of the heat sink 12, and a problem due to heat generated by the light source 11 is prevented.

(Main part Structure)

The heat sink 12 will be specifically described below. The radiator 12 is a member in which the rear surface of the base portion 22 is inclined from the front to the rear with respect to the upward pedestal portion 21. That is, the back surface of the base portion 22 is a planar structure, and is provided with an inclination in the upward direction as it goes toward the rear. Therefore, the thickness of the base portion 22 of the heat sink 12 is larger on the lower side of the light emitting element 11b than on the rear side of the base portion 22. As described above, when the projection type headlamp unit is configured, the globe 32, the projection lens 15, and the like are attached to the front side of the radiator 12. Assuming that the rear surface of the base portion 22 is inclined upward from the rear toward the front, the convection current F1 generated by the cooling fan unit 17 also flows into the space inside the reflector 13 and where the globe 32 is mounted, and therefore the convection current F1 is blocked by the reflector 13 and the globe 32. However, since the rear surface of the base portion 22 is inclined upward from the front to the rear, the convection current F1 flows from below the heat sink 12 toward the reflector 13 along the rear surface of the heat sink 12 and flows outside the reflector 13, and thus convection current occurs in one direction.

The heat sink 12 is provided with heat transfer ribs 25. The heat transfer rib 25 is disposed on the same surface side as the surface on which the light emitting element 11b is disposed, in a direction from the center of the light emitting element 11b toward the outside. That is, the heat transfer ribs 25 are arranged radially from the center of the light emitting element 11b and linearly through the center of the light emitting element 11 b. According to such a configuration, the heat transfer ribs 25 efficiently transfer heat generated by the light emitting element 11b to the outside of the light emitting element 11 b. The heat transfer ribs 25 are integrally formed with the base portion 22 and the fin portions 23 by die casting.

The fin unit 23 includes heat dissipation fins 23 a. The heat dissipating fins 23a are plate-like plate fins arranged at regular intervals in the horizontal direction. The heat sink 12 has a back surface of the base portion 22 extending in the front-rear direction below the light emitting element 11b, and the front end sides of the heat radiation fins 23a are inclined along the back surface of the base portion 22. According to such a configuration, since the back surface side of the base portion 22 and the distal end side of the heat radiating fins 23a are substantially parallel to each other, the height of the heat radiating fins 23a can be set to the maximum height within the moldable range in consideration of the height restriction of the heat radiating fins 23a by the mold. The inclination angle α of the heat radiation fins 23a from the horizontal direction toward the upper side on the distal end side is preferably inclined by 5 ° or more. In addition, the inclination angle alpha is only required to be 5-20 degrees, and 10-15 degrees is the best range.

(Effect)

The following describes the operational effects of the vehicle lamp according to the present embodiment, in comparison with conventional examples. Fig. 7 is a front view of a conventional heat sink 112. Fig. 8 is a plan view of a conventional heat sink 112. Fig. 9 is a right side view of the conventional heat sink 112. Fig. 10 is a sectional view a-a of the conventional heat sink 112 in fig. 7. Fig. 11 is a cross-sectional view B-B of the conventional heat sink 112 in fig. 7. The conventional heat sink 112 includes a base portion 122 and a fin portion 123 including heat radiating fins 123a, and the first light-shielding sheet 127 is also provided on the upper surface 112a of the base portion 122. In addition, the upper surface 112a is provided with a pedestal portion 121, a screw hole 112b, a screw hole 112c, and a screw hole 125a in addition to the first light-shielding piece 127. In such a configuration, the upper surface 112a of the base portion 122 is formed horizontally with the rear surface side of the base portion 122. Therefore, when the pedestal portion 121 is provided, the entire size becomes large, and therefore the thickness of the base portion 122 becomes thick as a whole. Therefore, the weight of the radiator 112 becomes large, and therefore, weight reduction cannot be achieved. Even if convection F11 occurs from below the base portion 122, convection F11 occurs in each of the front and rear directions of the base portion 122, and therefore a part of convection F11 flows into the space inside the reflector 13 and where the globe 32 is attached. As a result, the convection current F11 stagnates, and the heat radiation performance decreases.

Therefore, in the present embodiment, the back surface of the base portion 22 is inclined with respect to the pedestal portion 21. Therefore, the thickness of the base portion 22 can be reduced by the amount of inclination, and weight reduction can be achieved. The direction of the convection current F1 is a direction that flows upward from the front to the rear due to the upward flow of heat generated by the light-emitting element 11b and the inclination of the rear surface of the base portion 22. Therefore, the convection current F1 is not drawn into the space inside the reflector 13 from the front of the base portion 22 through the upper side of the light emitting element 11b, and therefore the convection current F1 is not obstructed by the reflector 13 and the like. As described above, the vehicle lamp can be made lightweight and have improved heat dissipation performance.

In the present embodiment, the thickness of the base portion 22 of the heat sink 12 is larger on the lower side of the light emitting element 11b than on the rear side of the base portion 22. Therefore, the heat capacity on the lower side of the light emitting element 11b serving as a heat source is large, and therefore the temperature rise rate around the light emitting element 11b can be made slow. Therefore, the characteristic change of the light-emitting element 11b due to heat can be suppressed.

In the present embodiment, the heat transfer rib 25 is disposed on the same surface side as the surface on which the light emitting element 11b is disposed in the direction from the center of the light emitting element 11b toward the outside, and transfers heat generated by the light emitting element 11 b. Therefore, radiant heat generated by the light emitting element 11b can be efficiently transmitted to the outside of the light emitting element 11b as conductive heat. Therefore, the temperature around the light-emitting element 11b can be efficiently transmitted to the heat sink 12, and therefore, an increase in the temperature of the light-emitting element 11b can be suppressed, and a change in characteristics such as a decrease in light emission efficiency due to heat of the light-emitting element 11b can be prevented.

In the present embodiment, the distal ends of the heat dissipating fins 23a are inclined along the back surface of the base portion 22. Therefore, the height of the heat radiating fins 23a can be maximized in consideration of the height restriction of the heat radiating fins 23a by the mold. Therefore, the heat radiation area of the heat radiation fins 23a can be increased to the maximum within the range of the formability, and the heat radiation effect can be promoted.

The vehicle lamp to which the present disclosure is applied has been described above based on the embodiments, but the present disclosure is not limited thereto, and modifications may be made without departing from the scope of the present disclosure.

For example, although an example in which the heat radiation fins 23a are plate-shaped plate fins has been described, the present invention is not particularly limited thereto. For example, the heat radiation fins 23a may be formed of corrugated fins.

Further, for example, an example in which the cooling fan unit 17 is provided and the convection F1 is generated by forced convection using the air volume supplied from the cooling fan unit 17 has been described, but the present invention is not particularly limited thereto. For example, the cooling fan unit 17 may not be provided, and the convection F1 may be generated by natural convection.

For example, although an example in which the back surface of the base portion 22 is flat and the inclination is provided has been described, the present invention is not particularly limited thereto. For example, the back surface of the base 22 may be curved and inclined. That is, the back surface of the base portion 22 may be entirely inclined upward from the front toward the rear, or may be partially different in shape.

Description of the symbols

11-a light source, 11 a-a substrate, 11 b-a light emitting element, 12, 112-a heat sink, 12a, 112 a-an upper surface, 12b, 12c, 112b, 112 c-a screw hole, 13-a reflector, 14-a cover unit, 15-a projection lens, 16-a lens holder, 17-a cooling fan unit, 21, 121-a base portion, 22, 122-a base portion, 23, 123-a fin portion, 23a, 123 a-a heat dissipating fin, 25-a heat transfer rib, 25a, 125a screw hole, 27, 127-a first light shielding sheet, 28-a second light shielding sheet, 31-a carrier plate, 32-a cover, 33-a solenoid, 37-a rotating shaft, 41-a rotating base portion, 42-a first cover portion, 43-a second cover portion, 44-a bearing sheet, 46-a first positioning sheet, 47-a second positioning sheet, 48-a transmission sheet, 49-an opening portion, 51-a coil, 52-a yoke, 53-a plunger, 54-a torsion coil spring, f1, F11-convection, α -tilt angle.