JP5177103B2 - LED heat sink - Google Patents

Description

  The present invention relates to a heat sink that dissipates heat generated by light emission of an LED.

  With the progress of technology for increasing the brightness of LEDs (light emitting diodes), LEDs have been used as light sources for vehicle headlamps. Although the LED has low power, low heat generation, and long life, when the LED is used as a light source such as a vehicle headlamp that requires high output, the amount of heat generated by light emission of the LED also increases. For this reason, the device for heat dissipation is needed in order to protect LED from a heat | fever. When an LED is exposed to a high temperature, the LED element is deteriorated by heat and the luminous efficiency is lowered. Therefore, the necessity of heat radiation is incandescent bulbs (including halogen lamps) or xenon conventionally used as a vehicle headlamp. Higher than discharge lamps. In Patent Document 1, the heat dissipation effect is enhanced by attaching a heat sink to the LED.

  FIG. 5 shows a vehicle headlamp described in Patent Document 1. The light source device 80 includes an LED 81 serving as a light source, a reflector 83 that reflects light emitted from the LED 81 forward (leftward in FIG. 5), a lens 84 that distributes the light reflected by the reflector 83, and And a heat sink 82 fixed behind the reflector 83.

  The heat sink 82 includes a flat plate-shaped heat transfer portion 82a on which the LEDs 81 and 81 are mounted on the upper surface and the lower surface, and a heat dissipation portion 82b including a plurality of heat dissipation fins, and is integrally formed with a metal having high heat conductivity. Yes. The surface of the heat transfer portion 82a that comes into contact with the substrate of the LED 81 is smoothed by polishing finish, and good heat conductivity can be ensured by improving the adhesion between the LED 81 and the heat transfer portion 82a. .

  By the way, in the light source device 80 shown in FIG. 5, since it is necessary to arrange the reflector 83 at a position away from the board of the LED 81, the board fixing screw and the power supply harness, a large separation is ensured between the LED 81 and the reflector 83. Therefore, the enlargement of the reflector 83, the enlargement of the lens 84, and the reduction of the light efficiency have been problems.

  In order to solve the above problems, the inventor has put into practical use the light source device 90 shown in FIG. The heat sink 92 of the light source device 90 includes a flat plate-shaped heat transfer portion 92a having a convex portion 92c on the upper surface, and a heat radiating portion 92b having a plurality of heat radiating fins. On the other hand, the LED unit 91 includes an LED substrate 91a and an LED holder 91b with the LED substrate 91a attached above the inner peripheral surface. The concave portion 91c is formed by the lower surface of the LED substrate 91a and the inner peripheral surface of the LED holder 91b. Is formed. And the LED unit 91 is mounted in the heat sink 92 by engaging the recessed part 91c of the LED unit 91, and the convex part 92c of the heat-transfer part 92a.

  Thus, by raising the LED board 91a with the convex part 92c, the separation between the LED board 91a and the reflector 93 can be reduced, and the reflector 93 can be reduced in size and light efficiency can be improved.

JP 2008-277237 A

  Since the heat sink 92 of the light source device 90 shown in FIG. 6 is formed by die casting of aluminum, thermal distortion occurs due to cooling after casting. This thermal strain is more likely to appear in a portion where the thickness of the cross-section is greatly changed or a portion where a temperature difference between the surface and the inside is likely to occur during cooling. Therefore, there is a problem that sink marks and cast holes due to thermal distortion are likely to occur on the upper surface of the thick convex portion 92c, and that the polishing operation for smoothing the upper surface of the convex portion 92c takes time.

  The present invention has been made in view of the above circumstances, and includes a flat plate-shaped heat transfer portion having a convex portion for mounting an LED substrate on the upper surface and a heat dissipation portion having a plurality of heat radiation fins, and is formed by metal casting. An object of the present invention is to provide an LED heat sink that does not require a polishing finish for smoothing the upper surface of the convex portion on which the LED substrate is mounted.

  Hereinafter, each means suitable for solving the above-described problems will be described with additional effects and the like as necessary. In the following description, the words “horizontal” and “vertical” are used for the purpose of clarifying the extending direction of the constituent members, but the word “horizontal” is not limited to strict horizontal. Substantially horizontal is also included. Similarly, the word “vertical” includes not only exact vertical but also substantially vertical.

  (1) The LED heat sink of the present invention is an LED heat sink formed by metal casting, and includes a horizontal plate portion, and a heat transfer portion including a convex portion protruding from the surface of the horizontal plate portion, The heat transfer part and a plate-like heat dissipation base provided so as to be capable of heat transfer, and a heat dissipation part including a plurality of heat dissipation fins protruding from one surface of the heat dissipation base, the convex part contains the LED substrate An engaging projection that engages with a recess formed on the back surface of the LED unit, and an outer peripheral wall that stands along the lip of the opening formed in the horizontal plate portion, and an end portion on the protruding side of the outer peripheral wall And a box shape provided with a horizontal wall on which the LED substrate is mounted.

  As described above, when the convex part protruding from the surface of the horizontal plate part of the heat transfer part is solid, the thickness of the cross section of the convex part is thick, and the temperature between the surface and the inside when the convex part is cooled. Since a difference is likely to occur, thermal distortion occurs in the convex portion due to cooling after casting of the heat sink, and sink marks and cast holes due to thermal strain tend to occur on the surface of the convex portion.

  According to the structure of this invention, the convex part which protrudes from the surface of the horizontal plate part of a heat-transfer part is exhibiting the hollow box shape. That is, the back surface of the convex portion is recessed toward the protruding direction. Therefore, since the outer wall and the horizontal wall forming the protrusions are thin, a difference in temperature between the surface and the interior is less likely to occur during cooling of the outer wall and the horizontal wall. The heat distortion of is difficult to occur. Thereby, since the smoothness of the surface (surface of a horizontal wall) of the convex part in which an LED board is mounted can be ensured, the polishing finish for smoothing the surface of a convex part becomes unnecessary, and the production efficiency of a heat sink is improved. be able to.

  (2) The LED heat sink of the present invention is preferably characterized in that the outer peripheral wall of the convex portion and the horizontal wall have the same or substantially the same thickness.

  According to such a configuration, the outer peripheral wall of the convex portion and the horizontal wall have the same or substantially the same thickness, so that the thickness of the cross section does not change greatly from the outer peripheral wall toward the horizontal wall. In this way, not only reducing the thickness of the cross section of the member but also reducing the change in the thickness of the cross section of the member will further reduce the concentration of thermal strain on the local part of the member. The thermal distortion of the convex portion due to the cooling of is less likely to occur. Thereby, since the smoothness of the surface (surface of a horizontal wall) of the convex part in which an LED board is mounted can be ensured, the polishing finish for smoothing the surface of a convex part becomes unnecessary, and the production efficiency of a heat sink is improved. be able to.

  (3) In the heat sink for LED of the present invention, preferably, the heat dissipating part is disposed on one end side in the horizontal direction of the heat transfer part so that the surface direction of the heat dissipating base part is directed vertically. The rear surface of the unit includes a metal heat transfer wall that protrudes from the back surface and connects the back surface and the heat dissipation unit, and the heat transfer wall transfers heat from the rim of the opening to the heat dissipation unit. In order to disperse and transmit in the vertical direction, the projecting length of the heat transfer wall is gradually increased from the mouth edge toward the heat radiating portion.

  The heat of the LED substrate is transmitted to the edge of the opening of the horizontal plate portion via the outer peripheral wall of the convex portion. Further, this heat is transmitted to the heat radiating base via the horizontal plate portion. However, in this heat transfer path, since the surface direction of the heat radiating base portion is directed in the vertical direction with respect to the horizontal plate portion, the opening edge of the horizontal plate portion is connected to the upper and lower ends of the heat radiating portion. The long heat transfer path leads to poor heat conduction efficiency.

  Here, in the configuration of the present invention, the rear surface of the horizontal plate portion is provided with a heat transfer wall whose protruding length gradually increases from the opening edge of the horizontal plate portion toward the heat radiating portion. As a result, the heat of the lip is distributed and transmitted in the vertical direction of the heat radiating portion by the heat transfer wall, and the heat transfer path from the lip to the lower end of the heat radiating portion is shortened, so that the heat conduction efficiency is improved.

  Moreover, since the convex part of this invention exhibits a hollow box shape, compared with the case where a convex part is solid, the heat capacity of a convex part has decreased, but a heat-transfer wall is arrange | positioned in the edge vicinity. As a result, the reduction in the heat capacity of the convex portion can be compensated.

  (4) The LED heat sink of the present invention preferably includes a plurality of the heat transfer units arranged in series in a direction away from the surface of the heat dissipation base, and each of the plurality of heat transfer units includes the heat transfer unit. The heat plate is disposed so that the back surfaces of the horizontal plate portions face each other and are separated from each other, and the horizontal end portions of the heat transfer portions are connected to each other by a metal vertical plate portion so that heat can be transferred. Each of the horizontal plate portions has a metal intermediate heat transfer wall protruding from the back surface and connecting the back surface and the vertical plate portion, and the intermediate heat transfer wall In order to disperse and transmit the heat of the rim in the vertical direction of the vertical plate portion, the projecting length of the intermediate heat transfer wall gradually increases from the lip toward the vertical plate portion. Features.

  According to such a configuration, a plurality of heat transfer portions are connected to each other by a vertical plate portion so as to be capable of heat transfer, thereby forming an aggregate of heat transfer portions, and on the back surface of each horizontal plate portion of each heat transfer portion, An intermediate heat transfer wall is provided that gradually protrudes from the edge of each opening of the horizontal flat plate portion toward the vertical plate portion. The heat transfer path that connects the edges of the openings of the horizontal plate portions can be shortened by the intermediate heat transfer wall. Thereby, it is possible to transfer the heat transferred from the plurality of LED substrates to each convex portion of each heat transfer portion to the heat radiating portion through a short heat transfer path, and the heat conduction efficiency is improved.

  Further, since the convex portion of the present invention has a hollow box shape, the heat capacity of the convex portion is reduced as compared with the case where the convex portion is solid, but an intermediate heat transfer wall is disposed near the mouth edge. This can compensate for the decrease in the heat capacity of the convex portion.

  According to the present invention, a heat sink formed of a flat plate having a convex portion for mounting an LED substrate on the upper surface and a heat radiating portion having a plurality of heat radiating fins, and a heat sink molded by metal casting, It is possible to provide an LED heat sink that does not require a polishing finish for smoothing the upper surface of the convex portion to be mounted.

It is sectional drawing of a light source device provided with the heat sink for LED in 1st Embodiment. It is sectional drawing of a light source device provided with the heat sink for LED in 2nd Embodiment. It is a perspective view explaining the structure of the light source device provided with the heat sink for LED in 3rd Embodiment, (a) is the vehicle by which the light source device is mounted, (b) has shown the external appearance of the light source device. It is sectional drawing of a light source device provided with the heat sink for LED in 3rd Embodiment. It is sectional drawing of a light source device provided with the conventional heat sink for LED. It is sectional drawing of the light source device provided with the other conventional heat sink for LED.

  Hereinafter, embodiments of the heat sink for LED of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
FIG. 1 shows a cross-sectional view of a light source device including an LED heat sink according to this embodiment. As shown in FIG. 1, the light source device 1 includes an LED unit 2 on which an LED element 2b serving as a light source is mounted, a heat sink 3 that cools the LED unit 2, and light emitted from the LED element 2b (see FIG. 1). 2, a reflector 11 that reflects in the left direction of the paper) and a lens (not shown) that distributes the light reflected by the reflector 11. The heat sink 3 is the LED heat sink of the present invention.

  The LED unit 2 includes an LED substrate 2a, an LED element 2b, an LED element cover 2c, and an LED holder 2d.

  The LED substrate 2a has a substantially rectangular plate shape in plan view, and a pair (not shown) formed of a metal material such as gold or copper at the center on a non-conductive layer provided as a base material and having no conductivity. The conductive pattern is formed. As the nonconductive layer of the LED substrate 2a, for example, various substrates such as a ceramic substrate (aluminum nitride substrate, alumina substrate, mullite substrate, glass ceramic substrate, etc.), a glass epoxy substrate, and the like can be used.

  As the LED element 2b, for example, a light emitting diode in which a phosphor is applied in a uniform film shape is used. The LED element 2b is bonded to the center of the upper surface of the LED substrate 2a with the lower surface straddling a pair of conductive patterns formed on the LED substrate 2a.

  The LED element cover 2c has an outer surface formed in a substantially hemispherical shape, and is joined to the upper surface of the LED substrate 2a so as to cover the LED element 2b. The LED element cover 2c is made of a transparent resin material that does not block the light of the LED element 2b. The LED element cover 2c is joined to the LED substrate 2a, so that the LED element 2b is disposed in a hollow sealed region in the LED element cover 2c.

  The LED holder 2d has a rectangular parallelepiped appearance, and is formed with a box opening 2f penetrating up and down in a substantially rectangular shape having a slightly larger dimension than the LED substrate 2a. A pressing claw 2g that abuts on the upper surface of the LED substrate 2a is formed above the inner peripheral surface of the box-cutting portion 2f. The LED holder 2d is formed of, for example, a resin material such as glass-containing PBT except for a connection terminal (not shown) connected to the power supply harness and a metal part such as a wiring part (not shown) extending from the connection terminal to the LED substrate 2a side. ing.

  The LED board 2a is inserted from below the box opening part 2f of the LED holder 2d, and the LED board 2a is moved downward by a support claw (not shown) provided in the LED holder 2d at a position where the upper surface of the LED board 2a is in contact with the pressing claw part 2g. Support and fix from. In this way, the LED unit 2 including the LED substrate 2a is assembled. In this state, a recess 2e is formed by the lower surface of the LED substrate 2a and the inner peripheral surface of the LED holder 2d.

  The heat sink 3 includes a heat transfer unit 6 on which the LED unit 2 is mounted, a heat dissipating unit 9 connected to the heat transfer unit 6 so as to be capable of heat transfer, and a plurality of connecting the lower surface of the heat transfer unit 6 and the heat dissipating unit 9. The heat transfer wall 10 is provided. The heat sink 3 is integrally formed by casting with a metal having high thermal conductivity such as aluminum or copper, and particularly preferably formed by die casting of aluminum.

  The heat transfer section 6 has a substantially quadrangular plate shape in plan view, the horizontal plate section 4 disposed in the horizontal direction or the substantially horizontal direction, and protrudes from the upper surface of the horizontal plate section 4, and has an LED unit at the top. And a convex portion 5 on which 2 is mounted.

  The convex portion 5 is an engaging projection that engages with the concave portion 2e formed on the back surface of the LED unit 2, and an outer peripheral wall 5a that stands along the edge of the opening 4a formed in the horizontal plate portion 4, The upper end of the outer peripheral wall 5a is closed, and a box shape having a horizontal wall 5b on which the LED substrate 2a is mounted is provided on the upper surface. That is, the back surface of the convex portion 5 is recessed upward. In addition, the outer wall 5a, the horizontal wall 5b, and the horizontal plate part 4 have the same or substantially the same thickness.

  The heat dissipating part 9 is provided integrally with the heat transfer part 6 and includes a heat dissipating base part 7 having a substantially circular plate shape in a side view and a plurality of heat dissipating fins 8 protruding from one surface of the heat dissipating base part 7. . The heat dissipating part 9 is arranged so that the surface direction of the heat dissipating base part 7 is directed in the vertical direction and the longitudinal surface direction of the heat dissipating fins 8 is directed in the vertical direction. One end side and the center part of the heat dissipation base 7 in the vertical direction are connected.

  The heat transfer wall 10 has a triangular plate shape in a side view, protrudes downward from the lower surface of the horizontal plate portion 4, and has a lower surface of the horizontal plate portion 4 and a surface of the heat radiating base portion 7 on the horizontal plate portion 4 side. It is a connecting member. In this embodiment, the side shape of the heat transfer wall 10 is a right-angled isosceles triangle, one side of the two orthogonal sides is connected to the lower surface of the horizontal plate part 4, and the other side is the heat dissipation base. 7 is connected to the surface of the horizontal plate portion 4 side. Further, the acute apex angle connected to the lower surface of the horizontal plate portion 4 is located near the mouth edge of the opening 4 a formed in the horizontal plate portion 4. That is, the projecting length of the heat transfer wall 10 is gradually increased from the edge of the opening 4 a toward the heat radiating portion 9.

  The reflector 11 is a substantially dome-shaped member disposed above the LED unit 2, is formed of a resin material, and an inner surface which is a light reflecting surface is plated by aluminum vapor deposition. When the light reflecting surface of the reflector 11 is cut in the front-rear direction (the left-right direction in FIG. 1), the cross-sectional shape has a substantially 1/4 parabolic shape. Since the LED element 2b is arranged at the position of the parabolic focal point, the light emitted from the LED element 2b is reflected by the reflecting surface of the reflector 11 and irradiated toward the front lens (not shown). .

  For assembling the LED unit 2 to the convex portion 5 of the heat sink 3, first, silicon grease containing a heat conductive filler is applied to the upper surface of the convex portion 5. And after covering LED unit 2 from the upper part of the convex part 5 so that the convex part 5 and the recessed part 2e of the LED unit 2 may engage, it fixes so that LED unit 2 may not remove | deviate by the fixing jig which is not shown in figure. In this state, the horizontal wall 5b of the convex portion 5 and the LED substrate 2a are in close contact with each other via silicon grease, and the heat generated by the light emission of the LED substrate 2a is efficiently transferred to the convex portion 5. In addition, instead of silicon grease, a heat conductive sheet made of silicon or resin having a thickness of 0.5 to 1 mm can be attached to the upper surface of the convex portion 5.

  According to such a configuration of the present embodiment, the convex portion 5 protruding from the upper surface of the horizontal plate portion 4 of the heat transfer portion 6 has a hollow box shape. Therefore, since the outer peripheral wall 5a and the horizontal wall 5b forming the convex part 5 are thin, a difference in temperature between the surface and the inner part hardly occurs when the outer peripheral wall 5a and the horizontal wall 5b are cooled, and the heat sink 3 is cast. Thermal distortion of the convex portion 5 due to subsequent cooling is unlikely to occur.

  Moreover, since the outer peripheral wall 5a and the horizontal wall 5b of the convex part 5 have the same or substantially the same thickness, the thickness of the cross section does not change greatly from the outer peripheral wall 5a toward the horizontal wall 5b. In this way, since the concentration of the thermal strain on the local portion of the member is further reduced by reducing the change in the thickness of the member cross-section rather than simply reducing the thickness of the member cross-section, the heat sink 3 casting The thermal distortion of the convex portion 5 due to the subsequent cooling is less likely to occur.

  As described above, the smoothness of the upper surface (the upper surface of the horizontal wall 5b) of the convex portion 5 on which the LED substrate 2a is mounted can be ensured, so that the polishing finish for smoothing the upper surface of the convex portion 5 is not required. Production efficiency can be improved.

  Further, since the heat dissipating part 9 is arranged such that the surface direction of the heat dissipating base part 7 is directed in the vertical direction and the longitudinal surface direction of the heat dissipating fin 8 is directed in the vertical direction, the heat dissipating fins 8 are arranged around the heat dissipating fins 8. Therefore, the heat dissipation effect of the heat sink 3 is improved.

  Further, a plurality of heat transfer walls 10 whose projecting length gradually increases from the lip of the opening 4a of the horizontal plate portion 4 toward the heat radiating portion 9 on the lower surface of the horizontal plate portion 4 of the heat transfer portion 6. I have. As a result, the heat of the rim is distributed and transmitted in the vertical direction of the heat radiating portion 9 by the heat transfer wall 10 and the heat transfer path from the lip to the lower end of the heat radiating portion 9 is shortened, so that the heat conduction efficiency is good. It becomes.

  Moreover, the heat-transfer wall 10 is arrange | positioned near the opening edge of the opening part 4a of the horizontal board part 4, and the reduction | decrease in the heat capacity by making the convex part 5 into the hollow box shape can be supplemented.

Second Embodiment
FIG. 2 shows a cross-sectional view of a light source device including the LED heat sink in the present embodiment. As shown in FIG. 2, the light source device 20 includes an LED unit 2 on which an LED element 2 b serving as a light source is mounted, a heat sink 23 that cools the LED unit 2, and light irradiated from the LED element 2 b (see FIG. 2). 2, a reflector 11 that reflects in the left direction of the paper) and a lens (not shown) that distributes the light reflected by the reflector 11. The heat sink 23 is the heat sink for LED of the present invention. In addition, about the member of the same structure as the light source device 2 of 1st Embodiment, while attaching | subjecting the same number also in this embodiment, description is abbreviate | omitted.

  The heat sink 23 is connected to the heat transfer part 26 on which the LED unit 2 is mounted, the heat transfer part 26 and the heat dissipating part 29 provided so as to be able to transfer heat, and the heat transfer part 26 and the heat dissipating part 29 to allow heat transfer. And a plurality of heat transfer walls 10 projecting downward from the lower surface of the heat transfer section 26.

  Similar to the first embodiment, the heat sink 23 is formed by casting with a metal having high thermal conductivity such as aluminum or copper, except for the graphite sheet 26a, and particularly preferably formed by die casting of aluminum. In the present embodiment, the heat transfer section 26 and the heat transfer wall 10 and the heat dissipation section 29 are formed as separate bodies.

  The heat transfer section 26 has a substantially rectangular plate shape in plan view, a horizontal plate section 24 arranged in the horizontal direction, and protrudes from the upper surface of the horizontal plate section 24, and the LED unit 2 is mounted on the top. And a plurality of heat transfer walls 10 described in the first embodiment are integrally formed by, for example, aluminum die casting.

  The convex portion 25 has the same shape as the convex portion 5 in the first embodiment, and an outer peripheral wall 25a standing along the edge of the opening 24a formed in the horizontal plate portion 24, and an upper end portion of the outer peripheral wall 25a. And a horizontal wall 25b on which the LED substrate 2a is mounted is provided on the upper surface.

  The connecting vertical wall portion 24b is a member that protrudes downward from the lower surface of the end portion of the horizontal plate portion 24 on the heat radiating portion 29 side, and the plurality of heat transfer walls 10 described in the first embodiment include the horizontal plate portion. The lower surface of 24 is connected to the surface of the connecting vertical wall portion 24b on the horizontal plate portion 24 side.

  The heat radiating portion 29 has the same shape as the heat radiating portion 9 in the first embodiment, and has a heat radiating base portion 27 that has a substantially circular plate shape in a side view, and a plurality of heat radiating fins 28 that protrude from one surface of the heat radiating base portion 27. For example, it is integrally formed by die-casting aluminum. The heat dissipating part 29 is arranged such that the surface direction of the heat dissipating base part 27 faces in the vertical direction and the longitudinal surface direction of the heat dissipating fins 28 faces in the vertical direction.

  The vertical wall part 24b for connection of the heat transfer part 26 and the center part in the vertical direction of the heat dissipation base part 27 are connected by a graphite sheet 26a so that heat can be transferred. The graphite sheet 26a is obtained by processing graphite into a sheet shape, and is a flexible belt-like material having a higher thermal conductivity than gold, silver, copper, or the like. The graphite sheet 26a is disposed in a sufficiently slackened state. The surface of the graphite sheet 26a is coated with, for example, a polyimide resin to prevent damage.

  Thus, the heat radiating part 29 is provided so as to be able to transfer heat with the heat transfer part 26 via the graphite sheet 26a. Therefore, from the viewpoint of heat conduction, the heat sink 23 is an integral structure, and the distinction between which member constituting the heat sink 23 belongs to a heat transfer member and which member belongs to a heat dissipation member. Absent. In the above description, for convenience, the connecting vertical wall portion 24b is defined as one member of the heat transfer portion 26. However, the connecting vertical wall portion 24b, the graphite sheet 26a, and the heat radiating portion 29 are considered as one body. Thus, the connecting vertical wall portion 24 b can be defined as one member of the heat radiating portion 29.

  Each member of the light source device 20 excluding the heat radiating portion 29 is covered with a resin housing H from the rear (the right direction in FIG. 2), and the inside of the housing H is kept waterproof. The heat radiating portion 29 is disposed on the rear outer side of the housing H, and an opening formed at the rear of the housing H is closed by the heat radiating base portion 27 of the heat radiating portion 29.

  Since the assembly of the LED unit 2 to the convex portion 25 of the heat sink 23 is the same as that of the first embodiment, the description thereof is omitted.

  According to the configuration of this embodiment, the heat radiating portion 29 of the heat sink 23 is disposed outside the housing H, and the heat radiating portion 29 is in contact with the outside air. Therefore, since the warm air around the heat radiating portion 29 is easily diffused into the outside air, the heat radiating effect of the heat radiating portion 29 is improved.

  Further, since the heat transfer section 26 and the heat dissipation section 29 are connected by a flexible graphite sheet 26a, for example, by rotating the heat transfer section 26 in the housing H, it is possible to adjust the light irradiation direction. It becomes. Other functions and effects are the same as in the first embodiment.

<Third Embodiment>
This embodiment is an embodiment in which the heat sink for LED of the present invention is embodied as a heat sink for a vehicle headlamp using an LED as a light source. FIG. 3A shows an appearance of a vehicle on which a light source device including an LED heat sink according to this embodiment is mounted, and FIG. 3B shows an appearance of the light source device. Moreover, sectional drawing of the light source device provided with the heat sink for LED in this embodiment is shown in FIG.

  As shown to Fig.3 (a), the headlamps L and L are arrange | positioned in the left-right front of the vehicle. The headlamp L includes a high beam that illuminates the distance of the vehicle and a low beam that illuminates the periphery of the vehicle, and the light source device 30 is used as a low beam.

  As shown in FIGS. 3B and 4, the light source device 30 includes two upper and lower LED units 2 and 2 on which LED elements 2 b serving as light sources are mounted, and a heat sink 33 that cools the LED units 2 and 2. An upper reflector 40 that reflects light emitted from the upper LED element 2b forward (leftward in FIG. 4), a lens 50 that distributes the light reflected by the upper reflector 40, and a lower LED A lower reflector 41 that reflects light emitted from the element 2b forward. The heat sink 33 is the LED heat sink of the present invention. In addition, about the member of the same structure as the light source device 2 of 1st Embodiment, while attaching | subjecting the same number also in this embodiment, description is abbreviate | omitted.

  The heat sink 33 includes an upper heat transfer portion 36 on which the LED unit 2 is mounted on the upper portion, a lower heat transfer portion 36 on which the LED unit 2 is mounted on the lower portion, and end portions of the upper and lower heat transfer portions 36 and 36. A vertical plate part 36a that couples the heat transfer parts to each other and a heat radiation part 39 that is connected to the upper heat transfer part 36 so as to be capable of heat transfer are provided. Further, the heat sink 33 includes a plurality of heat transfer walls 10 connecting the lower surface of the upper heat transfer section 36 and the heat radiating section 39, and the back surfaces of the upper and lower heat transfer sections 36, 36 (the lower surface of the upper heat transfer section 36 is the lower surface). The lower heat transfer section 36 has an upper surface) and a plurality of intermediate heat transfer walls 10a that connect the vertical plate section 36a.

  Similar to the first embodiment, the heat sink 33 is integrally formed by casting with a metal having high thermal conductivity such as aluminum or copper, and is particularly preferably formed by die casting of aluminum.

  The heat transfer section 36 has a substantially square plate shape in plan view, and projects from the horizontal plate section 34 arranged in the horizontal direction and the surface of the horizontal plate section 34, and the LED unit 2 is mounted on the projecting side. The convex part 35 to be provided is provided. The upper and lower heat transfer portions 36 and 36 are arranged in series in a direction away from the surface of the heat radiating base 37 described later of the heat radiating portion 39, and the back surfaces of the horizontal plate portions 34 and 34 of the heat transfer portions 36 and 36 are connected to each other. It arrange | positions so that it may oppose and space apart. Since the shape of the convex part 35 is the same as the convex part 5 in 1st Embodiment, description is abbreviate | omitted.

  The heat dissipating part 39 is provided integrally with the upper heat transfer part 36, and includes a heat dissipating base part 37 that has a substantially circular plate shape in a side view, and a plurality of heat dissipating fins 38 that protrude from one surface of the heat dissipating base part 37. ing. The heat dissipating part 39 is arranged so that the surface direction of the heat dissipating base part 37 faces in the up-and-down direction, and the longitudinal surface direction of the heat dissipating fins 38 faces in the up-and-down direction, and the horizontal plate part 34 of the upper heat transfer part 36 is horizontal. One end side in the direction is connected to the central portion in the vertical direction of the heat dissipation base 37.

  The intermediate heat transfer wall 10a has a triangular plate shape when viewed from the side, and each rear surface of each of the horizontal plate portions 34, 34 of the upper and lower heat transfer portions 36, 36 (the lower heat transfer portion 36 and the lower heat transfer portion 36 in the upper heat transfer portion 36). It is a member that protrudes from the upper surface of the heat portion 36 and connects the back surfaces of the horizontal plate portions 34 and 34 to the surface of the vertical plate portion 36a. In the present embodiment, the side shape of the intermediate heat transfer wall 10 is a right-angled isosceles triangle, one side of two orthogonal sides is connected to the back surface of the horizontal plate portion 34, and the other side is It is connected to the surface of the vertical plate portion 36a. Further, the acute apex angle connected to the back surface of the horizontal plate portion 34 is located in the vicinity of the mouth edge of the opening 34 a formed in the horizontal plate portion 34. That is, the protruding length of the intermediate heat transfer wall 10 is gradually increased from the edge of the opening 34a toward the surface of the vertical plate portion 36a.

  The upper reflector 40 is a substantially dome-shaped member disposed above the upper LED unit 2, is formed of a resin material, and an inner surface which is a light reflecting surface is plated by aluminum vapor deposition. When the light reflecting surface of the upper reflector 40 is cut in the front-rear direction (the left-right direction in FIG. 4), the cross-sectional shape has a substantially 1/4 elliptical shape. By arranging the upper LED element 2b at the position of the first focal point on the rear side of the elliptical shape, the light emitted from the LED element 2b is reflected by the reflection surface of the upper reflector 40 and is reflected on the lens 50. Irradiated towards. In addition, a shade (not shown) is disposed at the position of the second focal point on the front side of the elliptical shape, and this shade forms a cut-off line of light irradiated forward from the lens 50.

  The lens 50 is a plano-convex lens having a curved front surface and a flat rear surface. The lens 50 covers the cylindrical portion 40a in front of the upper reflector 40 and covers a ring-shaped fixing frame 51 from the front of the lens 50. Fixed. The light incident from the plane side of the lens 50 is converted into light that is nearly parallel by the lens 50 and is irradiated forward from the curved surface side of the lens 50 to illuminate the periphery in front of the vehicle.

  The lower reflector 41 is a curved member disposed below the lower LED unit 2, is formed of a resin material, and an inner surface which is a light reflecting surface is plated by aluminum vapor deposition. When the light reflecting surface of the lower reflector 41 is cut in the front-rear direction (the left-right direction in FIG. 4), the cross-sectional shape has a substantially 1/4 parabolic shape. Since the lower LED element 2b is arranged at the position of the parabolic focus, the light emitted from the LED element 2b is reflected by the reflecting surface of the reflector 41 and irradiated forward without passing through the lens. Illuminate the area near the front of the vehicle.

  Since the assembly of the LED unit 2 to the convex portion 35 of the heat sink 33 is the same as in the first embodiment, the description thereof is omitted.

  According to such a configuration of the present embodiment, the upper and lower heat transfer portions 36 and 36 are connected to be able to transfer heat by the vertical plate portion 36a, and the horizontal plate portions 34 and 34 of the heat transfer portions 36 and 36 are connected. On the back surface, a plurality of intermediate heat transfer walls 10a are provided, the protruding lengths of which gradually increase from the edges of the openings 34a, 34a of the horizontal plate portions 34, 34 toward the vertical plate portion 36a. The intermediate heat transfer wall 10a can shorten the heat transfer path that connects the edges of the openings 34a, 34a of the horizontal plate portions 34, 34. As a result, the heat transferred from the upper and lower LED units 2 and 2 to the convex portions 35 and 35 of the heat transfer portions 36 and 36 can be transferred to the heat radiating portion through a short heat transfer path. The heat conduction efficiency is improved.

  Further, by arranging the intermediate heat transfer wall 10a in the vicinity of the mouth edge of the opening portions 34a, 34a of the horizontal plate portions 34, 34, the reduction in heat capacity due to the convex portion 35 having a hollow box shape is compensated. Can do. Other functions and effects are the same as in the first embodiment.

  The storage box of the present invention is not limited to the first to third embodiments described above, and various modifications, improvements, etc. that can be made by those skilled in the art without departing from the gist of the present invention. It can be implemented in the form.

  For example, by rotating the heat sinks 3, 23, and 33 described in the first to third embodiments in an arbitrary direction, the light irradiation direction can be freely set.

  In the first to third embodiments, the heat sinks 3, 23 and 33 are integrally formed as much as possible. However, some of the members constituting the heat sink are separately formed and screwed or the like. Integration can also be achieved by bonding. For example, of the members constituting the heat sink 33 shown in the fourth embodiment, the heat transfer wall 10 and the intermediate heat transfer wall 10a are formed separately, and screwed or the like to fix the horizontal plate portion 34 and the vertical plate portion 36a. It can also be joined to the heat radiating base 37.

  Moreover, in 1st-3rd embodiment, although arrange | positioned so that the longitudinal surface direction of the radiation fins 8, 28, and 38 may face an up-down direction, it is not restricted to this, The longitudinal surface of the radiation fins 8, 28, and 38 The direction can be directed in various directions. For example, the heat dissipating base portions 7, 27 and 37 are rotated 90 degrees around the center of the surface of the heat dissipating base portions 7, 27 and 37, so that the longitudinal surface directions of the heat dissipating fins 8, 28 and 38 are arranged in the horizontal direction. be able to.

  Further, for example, by connecting the end portions of the horizontal plate portions 4 and 34 and the end portions of the heat dissipating base portions 7 and 37 with the surface direction of the heat dissipating base portions 7 and 37 oriented in the horizontal direction, the heat dissipating fins 8 and 38 are connected. It can arrange | position so that the longitudinal surface direction may face the front-back direction. In this case, the heat transfer wall 10 is not disposed.

DESCRIPTION OF SYMBOLS 1,20,30 ... Light source device 2 ... LED unit 2a ... LED board 2e ... Concave part 3,23,33 ... Heat sink 4,24,34 ... Horizontal plate part 4a, 24a, 34a ... Opening part 5,25,35 ... Convex Part 5a, 25a ... Outer peripheral wall 5b, 25b ... Horizontal wall 6, 26, 36 ... Heat transfer part 7, 27, 37 ... Heat release base 8, 28, 38 ... Heat release fin 9, 29, 39 ... Heat release part 10 ... Heat transfer Wall 10a: Intermediate heat transfer wall 36a: Vertical plate

Claims (4)

A heat sink for LED formed by metal casting,
A heat transfer part comprising a horizontal flat plate part and a convex part protruding from the surface of the horizontal plate part;
A plate-like heat dissipating base provided to be able to transfer heat with the heat transfer part, and a heat dissipating part comprising a plurality of heat dissipating fins protruding from one surface of the heat dissipating base,
The convex portion is an engaging projection that engages with a concave portion formed on the back surface of the LED unit that incorporates the LED substrate, and an outer peripheral wall that stands along the edge of the opening formed in the horizontal plate portion; An LED heat sink characterized by presenting a box shape including an end portion of the outer peripheral wall on the protruding side and a horizontal wall on which the LED substrate is mounted.   The heat sink for LED according to claim 1, wherein the outer peripheral wall of the convex portion and the horizontal wall have the same or substantially the same thickness. The heat dissipating part is arranged on one end side in the horizontal direction of the heat transfer part so that the surface direction of the heat dissipating base part faces the up and down direction,
On the back surface of the horizontal plate portion, a metal heat transfer wall that protrudes from the back surface and connects the back surface and the heat radiating portion is provided.
Since the heat transfer wall disperses and transfers the heat of the rim of the opening in the vertical direction of the heat radiating portion, the projecting length of the heat transfer wall gradually increases from the lip toward the heat radiating portion. The LED heat sink according to claim 1, wherein the LED heat sink is longer. A plurality of the heat transfer units arranged in series in a direction away from the surface of the heat dissipation base,
The plurality of heat transfer portions are arranged so that the back surfaces of the horizontal plate portions of the heat transfer portions face each other and are separated from each other, and the horizontal ends of the heat transfer portions are made of metal. It is connected so that heat can be transferred by the vertical plate part made of,
On the back surface of each horizontal plate portion, a metal intermediate heat transfer wall that protrudes from the back surface and connects the back surface and the vertical plate portion is provided.
The intermediate heat transfer wall disperses and transfers the heat of the lip of the opening in the vertical direction of the vertical plate portion from the lip toward the vertical plate portion of the intermediate heat transfer wall. 4. The heat sink for LED according to claim 1, wherein the protruding length is gradually increased.

Images