JP5385421B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a vehicle headlamp including a heat radiating member that radiates heat from a light source.

  Conventionally, as a vehicle headlamp using a light emitting diode as a light source, as disclosed in Patent Document 1, a projection lens, a shade, and a light source are arranged in this order from the front, and light from the light source is reflected forward. 2. Description of the Related Art A reflector is known in which a reflector is disposed facing a light source and a light source is attached to a heat radiating member that radiates heat from the light source.

  In this apparatus, the light source further includes a first light source having a first light emitting portion arranged substantially perpendicular to the optical axis in the upward direction, and a second light source arranged substantially vertically downward at a position below the optical axis. It is comprised with the 2nd light source which has a light emission part, and it is comprised so that it can irradiate with two beam patterns.

  A light emitting diode has a high heat generation density, and has a property that, when the temperature is high, the light emission efficiency is lowered and the life is shortened. When the light emitting diodes are arranged close to each other or the heat dissipation member is downsized to reduce the size of the entire apparatus, the heat generation density increases and the heat dissipation performance decreases.

  Therefore, as disclosed in Patent Document 2, an electric fan is arranged above the lamp chamber, and the air heated at the rear of the lamp chamber is sent to the front of the lamp chamber by the electric fan to force convection circulating in the lamp chamber. As shown in Patent Document 3, the coolant is caused to flow through the mounting substrate to which the light emitting element is attached to cool the light emitting element, and the refrigerant is sent to the heat radiating plate through a pipe by a pump. Also, a heat dissipation plate has been proposed that has improved heat dissipation by dissipating heat.

Japanese Patent No. 4289268 JP 2005-190825 A (paragraphs 0050 to 0054, etc.) JP 2009-147175 A

  However, in such a conventional device, forcibly cooling, an electric fan must be provided in the lamp chamber, or a pump for circulating the refrigerant must be provided. This requires a power other than the light emission for driving the device, which increases the power consumption of the entire apparatus.

  The subject of this invention is providing the vehicle headlamp which improved heat dissipation, without causing enlargement or an increase in power consumption.

In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
In the vehicle headlamp, in which a projection lens, a shade, and a light source are disposed in order from the front along the optical axis in a lamp chamber formed by a housing and a lens cover disposed in a front opening of the housing, the light source the heat from comprising a heat radiating member for radiating heat to the lamp chamber, the heat dissipation member is a plurality of plate-like radiation fins provided along the vertical direction, sequentially in the vertical direction between the radiating fins space A plurality of heat dissipating fins , and the heat dissipating fins are formed of a thin plate, and the thin plate is folded and overlapped so that the upper thickness of the heat dissipating fins is thicker than the lower thickness. By making the thickness of the upper part thicker than the lower part, the amount of heat transmitted between the upper side and the lower side of the radiating fin is changed, so that the temperature on the upper side is high and the temperature difference between the upper side and the lower side is increased. Vehicle headlamp to be that it is it.

  The vehicle headlamp according to the present invention changes the amount of heat transferred between the upper and lower sides of the radiating fin by making the thickness of the upper side of the radiating fin thicker than the thickness of the lower side. Therefore, there is an effect that the heat dissipation can be improved without increasing the flow velocity and causing an increase in size and power consumption.

It is a schematic longitudinal cross-sectional view of the vehicle headlamp as 1st Embodiment of this invention. It is AA sectional drawing of FIG. It is a B arrow line view of FIG. It is explanatory drawing of the heat radiating member of 1st Embodiment. It is other explanatory drawing of the radiation fin of 1st Embodiment. It is explanatory drawing of the other heat radiating member of 1st Embodiment. It is explanatory drawing of the heat radiating member of 2nd Embodiment. It is C arrow line view of FIG. It is explanatory drawing of the other heat radiating member of 2nd Embodiment. FIG. 10 is a DD cross-sectional view of FIG. 9. It is a schematic longitudinal cross-sectional view of the vehicle headlamp as 3rd Embodiment. It is an expansion perspective view of the mount member of 3rd Embodiment. It is a top view of the state which attached the heat radiating member to the mount member of 3rd Embodiment. It is a top view of the state which attached the heat radiating member to the other mount member of 3rd Embodiment. It is an expansion perspective view of another mount member of a 3rd embodiment. It is explanatory drawing of the heat radiation from the conventional radiation fin.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
First, a first embodiment will be described with reference to FIGS. As shown in FIG. 1, a front opening 2 is formed in the housing 1, and the periphery is closed with a wall except for the opening 2. A lens cover 4 is disposed in the opening 2 to substantially close the inside of the housing 1, and the housing 1 and the lens cover 4 form a lamp chamber 6.

  In the lamp chamber 6, a projection lens 8, a shade 10, and a light source 12 are arranged along the optical axis Z in order from the front to the rear. A reflector 14 that reflects light from the light source 12 is disposed opposite the light source 12.

  In the present embodiment, a plano-convex lens is used as the projection lens 8, and the focal point of the projection lens 8 and the focal point of the reflector 14 whose inner reflection surface is formed in a curved shape such as a paraboloid of revolution are at substantially the same position. It is arranged to be. A part of the light reflected by the reflector 14 is blocked by the shade 10, and the light not blocked by the shade 10 is irradiated forward by the projection lens 8. In the present embodiment, as shown in FIG. 2, the shade 10 also serves as a support member for the projection lens 8.

  A light emitting diode is used for the light source 12, and the light source 12 is attached to the horizontal plate portion 18 of the heat radiating member 16. The horizontal flat plate portion 18 is formed in a flat plate shape in the horizontal direction, and a vertical plate portion 20 is integrally provided at the rear end of the horizontal plate portion 18.

  The vertical plate portion 20 is substantially perpendicular to the optical axis Z and is erected in the up-down direction. A horizontal plate portion 18 is provided at substantially the center of the vertical plate portion 20 in the up-down direction. The front end side of the horizontal plate portion 18 is attached to a support member 22 erected on the bottom wall 1 a of the housing 1, and the rear end side of the shade 10 is attached to the support member 22.

  A sufficient space through which air can flow is secured between the lower end of the vertical plate portion 20 and the bottom wall 1a of the housing 1, and also between the upper end of the vertical plate portion 20 and the ceiling wall 1c of the housing 1. Sufficient space for air to flow is secured. The horizontal plate portion 18 and the vertical plate portion 20 are formed of a material having good thermal conductivity, for example, aluminum.

  As shown in FIG. 3, a plurality of heat radiation fins 24 are arranged on the back surface 20 a of the vertical plate portion 20. The heat radiating fins 24 are formed in a plate shape and extend rearward substantially perpendicularly to the back surface 20a of the vertical plate portion 20 and are provided along the vertical direction. The plurality of radiating fins 24 are arranged at a predetermined interval so that air can flow between them.

  The heat radiating fins 24 are formed to have the same length as that of the vertical plate portion 20 in the vertical direction, and are disposed so as to have a predetermined space between the rear wall 1 b of the housing 1. Between the upper side of the radiation fin 24 and the ceiling wall 1c of the housing 1, it is arranged at a predetermined interval so that air can flow.

  Each radiating fin 24 is formed with a slit 26 from the lower side to the upper side of the radiating fin 24. The slit 26 includes a vertical slit portion 26a that extends vertically from the lower end of the radiating fin 24 along the vertical plate portion 20, and an oblique slit portion 26b that extends obliquely upward from the upper end of the vertical slit portion 26a. I have.

  The upper end of the oblique slit portion 26b is formed to be approximately the same height as the lower surface of the horizontal plate portion 18 or lower than that. Further, the upper end of the oblique slit portion 26b is extended until it reaches approximately the middle of the width in the front-rear direction of the radiating fin 24.

  The heat radiating fins 24 are made of a material having good thermal conductivity, for example, an aluminum thin plate. In the first embodiment, as shown in FIG. 4, two slits 26 are formed at the center of a rectangular thin plate 28. Are formed at left and right symmetrical positions with an interval between the two radiation fins 24. Then, two radiating fins 24 are integrally formed by bending each side at a right angle along the alternate long and short dash line 25 at intervals. A plurality of sets of two radiating fins 24 are further formed, and these are attached to the back surface 20a of the vertical plate portion 20 by brazing or the like at a similar interval. Thereby, the radiation fin 24 in which the slit 26 is formed can be easily formed by pressing or the like.

  Further, as shown in FIG. 5 (a), the corners of the aluminum thin plate 29 are cut into triangles, and the opposite corners are cut according to the slits 26. The heat dissipating fins 24 may be formed. The plurality of heat radiating fins 24 may be attached to the back surface 20a of the vertical plate portion 20 by brazing or the like at intervals.

  Further, as shown in FIG. 5 (b), the aluminum thin plate 30 is cut to form the shape shown in FIG. 5 (a) symmetrically at intervals. Then, both sides are bent 180 degrees along the alternate long and short dash line 31, and further, two radiating fins 24 are formed by folding each side at right angles along the alternate long and short dash line 33 with a gap in the center. You may attach to 20a by brazing etc. at intervals. Further, the slit 26 is not limited to being formed in a straight line shape, and as shown in FIG. 6, a curved slit 32 may be formed upward from the lower end of the radiation fin 24.

  On the other hand, as shown in FIG. 1, the lead wire 34, one end of which is connected to the light source 12, is led out from the rear wall 1 b of the housing 1 and connected to the drive circuit 38 via the connector 36. The drive circuit 38 is a well-known circuit that controls power supply to the light source 12.

Next, the operation of the vehicle headlamp according to the first embodiment will be described.
When the light source 12 is turned on as the vehicle is driven, the light emitted from the light source 12 is reflected by the reflector 14, and part of the light reflected by the reflector 14 is blocked by the shade 10. The light that is not blocked is irradiated forward by the projection lens 8.

  Heat from the light source 12 is transmitted from the horizontal plate portion 18 to the vertical plate portion 20, and is transmitted from the vertical plate portion 20 to the plurality of heat radiation fins 24. Due to heat radiation from the heat radiation fins 24, the air around the heat radiation fins 24 is warmed and expanded, and the density of the air is lowered.

  The air that has become lighter due to expansion rises between the plurality of heat radiation fins 24 toward the ceiling wall 1 c of the housing 1. Due to the heat radiation from the plurality of heat radiation fins 24, the air between the plurality of heat radiation fins 24 is warmed and the air rises continuously.

  The raised air flows toward the front lens cover 4 along the ceiling wall 1c of the housing 1 as indicated by an arrow in FIG. The warmed air exchanges heat with the rear wall 1b, the ceiling wall 1c and the side wall of the housing 1, and external air through the lens cover 4, and the air in the lamp chamber 6 is cooled. Is done.

  Further, the air descends along the lens cover 4, flows along the bottom wall 1 a of the housing 1 from the lower side of the lens cover 4, and passes between the bottom wall 1 a of the housing 1 and the lower side of the shade 10. Meanwhile, heat exchange is performed with the outside air via the bottom wall 1a.

  Therefore, the air rises through between the heat radiating fins 24, and during that time, the air is warmed again by heat radiation from the heat radiating fins 24 and rises toward the ceiling wall 1 c of the housing 1. In this way, the air that has been warmed through between the plurality of radiating fins 24 flows along the inside of the lens cover 4 from the ceiling wall 1c of the housing 1, is cooled, and flows along the bottom wall 1a of the housing 1. Again, a convection path flows between the plurality of heat radiation fins 24.

  In particular, when the vehicle travels, the lens cover 4 is exposed to outside air, so heat exchange between the outside air outside the lens cover 4 and the inside air is promoted, and the convection path is By being formed inside, cooling of air is promoted.

  When radiating heat from the radiating fins 24, as shown in FIG. 4, heat from the light source 12 is transmitted to the vertical plate part 20 through the horizontal plate part 18, and is transmitted from the vertical plate part 20 to the radiating fin 24. When the heat is transferred from the vertical plate portion 20 to the radiating fin 24, heat transfer is restricted by the slit 26, and the heat is once transferred from the vertical plate portion 20 to the radiating fin 24 above the slit 26.

  In the radiating fin 24, part of the heat transferred to the radiating fin 24 is transferred to the upper side of the radiating fin 24 through a linear heat transfer path as shown by a thin line arrow in FIG. Is a curvilinear heat transfer path that bypasses the slit 26, and is transmitted to the radiation fins 24 below the slit 26.

  When the air rises through between the heat radiation fins 24, the air is warmed by heat radiation from the heat radiation fins 24. At that time, since the heat is transferred through the heat transfer path that bypasses the slit 26 to the lower side of the radiation fin 24, the heat transfer path becomes longer.

  Even while heat is transferred through the long heat transfer path, the heat is dissipated to the air passing between the heat dissipation fins 24, and the amount of heat reaching the lower side of the heat dissipation fin 24 at the end of the long heat transfer path is reduced. The temperature of the upper side of the heat dissipating fin 24 through which heat is transmitted is higher than that of the lower side of the heat dissipating fin 24 through which heat is transmitted through a long heat transfer path. Thereby, a temperature deviation occurs between the upper side and the lower side of the radiating fin 24.

  At the lower side of the radiating fin 24, the temperature rise of the air warmed by the heat radiation is small, and when the air warmed at the lower side rises and is warmed by the heat radiating on the upper side of the radiating fin 24, the air from the lower side And the temperature difference between the upper temperature of the heat dissipating fins 24 and the temperature above. Therefore, since a large temperature difference is obtained, the air is warmed by heat radiation from the upper side of the radiation fins 24, the temperature of the air is increased, and the density of the air is further decreased.

  By providing the slit 26, a temperature deviation occurs between the upper side and the lower side of the radiating fin 24, the air density on the upper side of the radiating fin 24 becomes lower, and the flow velocity of the air between the radiating fins 24 becomes larger.

  For example, as shown in FIG. 16, in the case of the radiating fin 110 that does not form the slit 26, heat is transferred from the vertical plate portion 20 where the horizontal plate portion 18 is provided to the radiating fin 110 through a radial heat transfer path. . Therefore, heat is transmitted to the radiating fins 110 substantially uniformly throughout the entire radiating fins 110, and there is little difference in the amount of heat transmitted over the entire radiating fins 110, and there is little temperature deviation across the entire radiating fins 110.

  Therefore, the air that enters between the radiation fins 110 and rises through the radiation fins 110 from the lower side of the radiation fins 110 is first warmed by the heat radiation from the lower side of the radiation fins 110 and the temperature rises. As the temperature further rises above the radiation fins 110, the temperature of the air rises due to heat radiation from the radiation fins 110. However, since the temperature is substantially uniform throughout the radiation fins 110, the air is heated below the radiation fins 110. The temperature difference between the temperature of the air and the temperature above the radiating fin 110 is small. Therefore, since the temperature difference is small, the temperature rise of the air is small, the decrease of the air density is small, and the flow velocity of the air between the radiating fins 24 is small.

  On the other hand, in the first embodiment, by providing the slit 26, a temperature deviation occurs between the upper side and the lower side of the radiating fin 24, and the air flow rate between the radiating fins 24 increases. Thereby, more air passes between the radiation fins 24, the heat dissipation performance of the radiation fins 24 is improved, and the temperature rise of the air in the lamp chamber 6 can be suppressed, so the temperature rise of the light source 12 and the heat radiation member 16 is suppressed. it can. As a result, heat dissipation can be improved without increasing the size and power consumption.

  Further, by forming a convection along the lens cover 4 from the ceiling wall 1c of the housing 1 and along the bottom wall 1a of the housing 1, snow is placed outside the lens cover 4 when the vehicle travels in a cold region. In some cases, ice or ice may adhere, but by warming the inside of the lens cover 4, the snow and ice on the outside of the lens cover 4 are melted, and the forward light irradiation is performed well. Since a forward air flow is generated, the horizontal plate portion 18, the shade 10, the reflector 14, the projection lens 8, and the like are also cooled by this air flow.

  Next, a second embodiment (embodiment corresponding to the present invention) different from the first embodiment described above will be described with reference to FIGS. The same members as those in the first embodiment described above are denoted by the same reference numerals and detailed description thereof is omitted. The same applies below.

  The second embodiment is different in configuration from the heat dissipating fins 24 in which the slits 26 of the first embodiment are formed, and the heat dissipating fins 54 of the second embodiment do not form the slits 26 as shown in FIG. In addition, a rectangular thin plate 56 made of aluminum is formed by folding the upper side 1/3 indicated by a one-dot chain line 57 in FIG.

  As a result, the lower half 58 of the lower half of the radiating fin 54 is formed with a thickness of one sheet 56, and the upper half 60 of the upper half is formed with a thickness of two sheets of the thin plate 56. The heat capacity is different between the upper side and the upper side.

  As shown in FIG. 8, a plurality of the radiating fins 54 are arranged on the vertical plate portion 20 in the left-right direction and attached by brazing or the like. A step 62 corresponding to the plate thickness is formed at the center of the radiating fin 54 in the vertical direction and at the boundary between the lower portion 58 and the upper portion 60.

  When the heat radiation fins 54 are used, the air passing between the heat radiation fins 54 is first warmed by heat radiation from the lower portions 58 of the heat radiation fins 54, and rises between the heat radiation fins 54, and the upper portions 60 of the heat radiation fins 54. It is further warmed by heat radiation from and rises toward the ceiling wall 1c.

  At this time, since the heat capacity of the lower portion 58 is small and the heat capacity of the upper portion 60 is large, the amount of heat transferred to the lower portion 58 of the radiating fin 54 is small, and the amount of heat transferred to the upper portion 60 of the radiating fin 54 is large. Therefore, due to heat radiation to the air passing between the heat radiation fins 54, the temperature of the air in the lower portion 58 is low, and the temperature of the air in the upper portion 60 is higher than that in the lower portion 58. A temperature deviation occurs between the lower portion 58 and the upper portion 60.

  At the lower part 58 of the radiating fin 54, the temperature rise of the air warmed by the heat radiation is small, and when the air warmed at the lower side rises and is warmed by the heat radiation at the upper part 60 of the radiating fin 54, A temperature difference between the temperature of the air and the temperature of the upper portion 60 of the radiating fin 54 is obtained. Therefore, since a large temperature difference is obtained, the air is warmed by heat radiation from the upper portion 60 of the radiation fin 54, the temperature of the air is increased, and the density of the air is further decreased.

  By changing the thickness between the lower part 58 and the upper part 60 of the radiating fin 54, a temperature deviation occurs between the upper side and the lower side of the radiating fin 54, and the air density on the upper side of the radiating fin 54 becomes lower. The air flow rate between 54 increases.

  Therefore, as in the first embodiment, more air passes between the heat radiating fins 54, the heat radiating performance of the heat radiating fins 54 is improved, and the temperature rise of the air in the lamp chamber 6 can be suppressed. The temperature rise of the member 16 can be suppressed. As a result, heat dissipation can be improved without increasing the size and power consumption.

  Further, since the thickness is different between the lower portion 58 and the upper portion 60 of the radiating fin 54, the interval between the radiating fins 54 is narrower on the lower side and narrower on the upper side, so that the passage becomes narrower as the air rises. Therefore, due to the chimney effect, the air flow rate is increased and heat dissipation is improved.

  Furthermore, in the second embodiment, since the step 62 is provided between the radiating fins 54, the air rising through the radiating fins 54 hits the step 62, and the flow is disturbed, so that the turbulent flow is generated. Occurs and the air is agitated.

  Around the radiating fin 54, due to heat transfer from the radiating fin 54 to the air, a temperature boundary layer is formed in which the surface temperature of the radiating fin 54 is the highest and the temperature decreases as the distance from the surface of the radiating fin 54 increases.

  And the temperature boundary layer around the radiation fin 54 is disturbed by the generation of turbulent flow. Thereby, the low temperature air contacts the surface of the radiation fin 54, and since the difference between the air and the surface temperature is large, heat exchange is promoted and heat dissipation is improved.

  The heat dissipating fins 64 are not limited to the heat dissipating fins 54 described above. As shown in FIG. 9, the heat dissipating fins 64 are cut in advance in the middle of the upper half of the thin plate 66 made of aluminum and indicated by a one-dot chain line 67 in FIG. Is formed diagonally. Then, it is folded 180 degrees at the middle one-dot chain line 67 and overlapped on the lower side. Further, the heat dissipating fin 64 may be formed by the one-dot chain line 69 in the middle of the folded upper half and the lower side of the notch 68 folded back by 180 degrees and overlapped on the upper side.

  Thereby, the upper part 70 of the radiation fin 64 is formed to have a thickness of three sheets, the middle portion 72 of the middle triangle is formed to have a thickness of two sheets, and the lower part 74 of the radiation fin 64 is a single sheet. The heat capacity is different between the upper portion 70, the intermediate portion 72, and the lower portion 64 of the radiating fin 64.

  As shown in FIG. 10, a plurality of the heat radiating fins 64 are arranged on the vertical plate portion 20 in the left-right direction and attached by brazing or the like. In the vertical direction of the radiating fin 64, a step 76 having a thickness is formed at the boundary between the lower portion 74 and the intermediate portion 72, and a step 78 having a thickness is formed at the boundary between the intermediate portion 72 and the upper portion 70. Is done. Further, a step 80 corresponding to two plate thicknesses is formed at the boundary between the lower portion 74 and the upper portion 70.

  When using the radiation fins 64, the air passing between the radiation fins 64 is first warmed by heat radiation from the lower portions 74 of the radiation fins 64, and rises between the radiation fins 64, so It is warmed by heat radiation from 72. And if the said air rises further, it will be heated further by the thermal radiation from the upper part 70, and will rise toward the ceiling wall 1c.

At this time, since the heat capacity of the lower part 74 is small and the heat capacity of the upper part 70 is large, the temperature of the lower part 74 is low and the temperature of the upper part 70 is higher than that of the lower part 74. A temperature deviation occurs between the lower portion 74, the intermediate portion 72, and the upper portion 70, and a large temperature difference is obtained, so that the air density further decreases at the upper portion 70.

  By changing the thickness between the lower part 74, the intermediate part 72, and the upper part 70 of the radiating fin 64, a temperature deviation occurs between the upper side, the middle part and the lower side of the radiating fin 64, and the air density on the upper side of the radiating fin 64 is reduced. It becomes lower and the flow velocity of the air between the radiation fins 64 becomes larger.

  Therefore, as in the first embodiment, more air passes between the heat radiating fins 64, the heat radiating performance of the heat radiating fins 64 is improved, and the temperature rise of the air in the lamp chamber 6 can be suppressed. The temperature rise of the member 16 can be suppressed. As a result, heat dissipation can be improved without increasing the size and power consumption.

  Further, since the thicknesses of the lower portion 74, the intermediate portion 72, and the upper portion 70 of the radiating fin 64 are different, the interval between the radiating fins 64 is wide on the lower side and narrower on the upper side, so that the passage becomes narrower as the air rises. . Therefore, due to the chimney effect, the air flow rate is increased and heat dissipation is improved.

  Further, since the steps 76, 78, 80 are provided between the radiating fins 64, the air rising through the radiating fins 64 hits the steps 76, 78, 80, and the flow is disturbed and disturbed. A stream is generated and stirred.

  Due to the generation of turbulent flow, the temperature boundary layer around the radiating fin 64 is disturbed. Thereby, the low temperature air contacts the surface of the radiation fin 64, and since the difference between the air and the surface temperature is large, heat exchange is promoted and heat dissipation is improved.

Subsequently, a third embodiment different from the above-described embodiment will be described with reference to FIGS.
In the first and second embodiments described above, the light source 12 is attached to the horizontal plate portion 18 and the horizontal plate portion 18 is attached to the vertical plate portion 20, but in the third embodiment, as shown in FIG. The light source 12 is attached to a prismatic mount member 88, and the vertical plate portion 20 of the heat dissipation member 16 is attached to the mount member 88. A drive circuit 90 that controls power supply to the light source 12 is disposed on the mount member 88.

  As shown in FIG. 12, the mount member 88 is formed in a quadrangular prism shape. The light source 12 is attached to the upper surface of the mount member 88 with screws 92, and the drive circuit 90 is inserted therein. The drive circuit 90 and the light source 12 are connected by a lead wire 94, and the drive circuit 90 and the power source 94 are connected by a lead wire 96 and a connector 36.

  As shown in FIG. 13 (a), a vertical plate portion 20 erected in the vertical direction is attached to the back surface of the mount member 88, and a plurality of radiating fins 24 are attached to the vertical plate portion 20 side by side. It has been.

  Further, the present invention is not limited to the case where one set of the vertical plate portion 20 and the plurality of radiating fins 24 is attached to the mount member 88, and as shown in FIG. The heat radiating fins 24 may be attached, and two sets may be attached to the mount member 88.

  Furthermore, as shown in FIG. 14, the mount member 88 may be formed in a hexagonal column shape, and similarly, the drive circuit 90 may be built in the mount member 88. Then, the vertical plate portion 20 and the plurality of heat radiating fins 24 may be attached to the three side surfaces of the mount member 88, respectively, and three sets may be attached to the mount member 88.

  Since heat is also generated from the drive circuit 90, the vertical plate portion 20 and the heat radiation fin 24 can be used as a heat radiation plate of the drive circuit 90 by disposing the drive circuit 90 on the mount member 88. At this time, by disposing the light source 12 and the drive circuit 90 so as to be distant from each other, the drive circuit 90 is not affected by the heat from the light source 12, and the heat from the light source 12 passes through the mount member 88. The heat is transmitted to the vertical plate portion 20 and the heat radiating fins 24 and radiated from the heat radiating fins 24.

  Further, the mount member 88 is not limited to a rectangular column shape or a hexagonal column shape, and as shown in FIG. 15, an upper wall portion 96 to which the light source 12 is attached, and a back wall portion 98 extending vertically downward from the upper wall portion 96. And a mount member 104 including a bottom wall portion 100 extending horizontally forward from the lower end of the back wall portion 98, and a front wall portion 102 extending from the bottom wall portion 100 to the upper wall portion 96. . The vertical plate portion 20 and the plurality of radiating fins 24 are attached to the back wall portion 98, respectively.

  The drive circuit 90 is disposed inside the upper wall portion 96, the back wall portion 98, the bottom wall portion 100, and the front wall portion 102. A gap 106 may be secured between the upper wall portion 96 and the front wall portion 102, and heat from the drive circuit 90 may be released through the gap.

  The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Opening part 4 ... Lens cover 6 ... Light chamber 8 ... Projection lens 10 ... Shade 12 ... Light source 14 ... Reflector 16 ... Radiation member 18 ... Horizontal board part 20 ... Vertical board part 24,54,64,110 ... Radiation fins 26, 32 ... slit 26a ... vertical slit portion 26b ... oblique slit portion 28, 29, 30, 56, 66 ... thin plate 38, 90 ... drive circuit 62, 76, 78, 80 ... step 88, 104 ... mount member

Claims (5)

In a vehicle headlamp in which a projection lens, a shade, and a light source are arranged in order from the front along the optical axis in a lamp chamber formed by a housing and a lens cover arranged in the front opening of the housing.
A heat radiating member for radiating heat from the light source into the lamp chamber;
The heat dissipation member is a plurality of plate-like radiation fins provided along the vertical direction, a plurality of heat radiation fins constituting the continuous space in the vertical direction between the heat radiating fins,
The radiating fin is formed of a thin plate, and the thin plate is folded and overlapped so that the upper thickness of the radiating fin is thicker than the lower thickness,
By making the thickness of the upper side of the radiating fin thicker than the thickness of the lower side, the amount of heat transferred between the upper side and the lower side of the radiating fin is changed, so that the temperature on the upper side is high and the temperature difference between the upper side and the lower side is changed. A vehicular headlamp characterized by an increase in size. The vehicle headlamp according to claim 1, wherein a step is formed in the heat radiating fin. The vehicle headlamp according to claim 1 or 2 , wherein the light source is attached to the heat dissipation member via a mount member, and a drive circuit for the light source is disposed on the mount member. The vehicle headlamp according to claim 3 , wherein a plurality of the heat radiating members are attached to the mount member. The vehicle headlamp according to claim 3 or 4 , wherein the drive circuit is attached to a position of the mount member away from the light source.

Images