JP2013152852A - Vehicular lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular lamp that can suitably melt snow stuck to a light-transmitting cover.SOLUTION: In a vehicular lamp, a light-transmitting cover 14 forms at least a part of a lamp chamber for storing a light-emitting element 30, and transmits light from the light-emitting element 30 as a lamp light source to make the light irradiated toward front of the lamp. A heater 40 is arranged as a heat source separately from the light-emitting element 30. A fan 42 circulates heat of the heater 40 in the lamp chamber by convection. A PTC heater is adopted as a heater 40. A duct 44 guides air blown off by the fan 42 to an upper part along an internal surface of the light-transmitting cover 14.

Description

  The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp including a translucent cover that transmits light from a lamp light source so as to irradiate light in front of the lamp.

  Appropriate irradiation of light by the vehicle headlamp is extremely important for driving safely at night by brightly illuminating the front of the vehicle. However, for example, if snow is left on the vehicle headlamp, it may be difficult to irradiate with appropriate light. For this reason, for example, a technique for melting snow using heat generated by a semiconductor light emitting element such as an LED (Light Emitting Diode) has been proposed (see, for example, Patent Document 1). For example, a vehicular lamp in which a resistance heating element is disposed in a lens of the lamp has been proposed (see, for example, Patent Document 2).

JP 2009-76323 A JP 2008-103086 A

  However, for example, the amount of heat generated by a discharge lamp or a semiconductor light emitting element may make it difficult to melt snow appropriately. Further, if the resistance heating element is disposed directly in the lens of the lamp, the light distribution pattern and the appearance of the vehicle may be affected.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicular lamp that can appropriately melt snow attached to a light-transmitting cover.

  In order to solve the above problems, a vehicle lamp according to an aspect of the present invention forms at least a part of a lamp chamber that houses a lamp light source, and transmits light from the lamp light source so as to irradiate light in front of the lamp. A translucent cover, a heat source provided separately from the lamp light source, and a fan that convects the heat of the heat source into the lamp chamber are provided. According to this aspect, even when it is difficult to melt snow with the amount of heat of the lamp light source, it is possible to appropriately melt the snow attached to the translucent cover. For this reason, the safety | security at the time of the driving | running | working at night when it snows can be improved.

  The heat source may be a PTC (Positive Temperature Coefficient) heater. According to this aspect, since snow can be melted efficiently, fuel consumption or electric power can be suppressed.

  You may further provide the duct which guides the air in a lamp chamber so that the heat of a heat source may be convected. According to this aspect, the heat of the heat source can be convected in the lamp chamber so that snow attached to the translucent cover can be removed appropriately. For this reason, more appropriate snow melting is possible.

  A duct for guiding the air blown out by the fan may be further provided. The fan is disposed in the vicinity of the lamp light source so as to dissipate heat generated by the lamp light source, the heat source is disposed closer to the translucent cover than the lamp light source, and the duct extends to guide air from the fan to the heat source. May be. According to this aspect, the convection for melting snow can be formed in the lamp chamber using the fan for dissipating the heat of the lamp light source. For this reason, compared with the case where the fan for a heat source is provided separately, cost and space can be suppressed.

  The vehicular lamp may be used as a headlamp for an electric vehicle. In the case of an electric vehicle, the environmental temperature at the place where the headlamp is installed is lower than that of a conventional gasoline vehicle, so that it may be difficult to melt snow with a normal headlamp. The vehicular lamp is particularly suitable as a headlamp for an electric vehicle because it can melt snow appropriately even when the ambient temperature at the installation site is low.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle lamp which can melt snow appropriately for the snow adhering to the translucent cover can be provided.

It is sectional drawing which shows the structure of the vehicle headlamp which concerns on 1st Embodiment. It is a figure which shows typically the structure of the vehicle headlamp which concerns on 2nd Embodiment. It is a figure which shows typically the structure of the vehicle headlamp which concerns on 3rd Embodiment. It is a figure which shows typically the structure of the vehicle headlamp which concerns on 4th Embodiment. It is a perspective view which shows the structure of a light emitting module.

  Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a vehicle headlamp 10 according to the first embodiment. The vehicle headlamp 10 includes a lamp body 12, a translucent cover 14, and a lamp unit 16. Hereinafter, the left side in FIG. 1 will be described as the front of the lamp, and the right side will be described as the rear of the lamp. FIG. 1 shows a cross section of a vehicle headlamp 10 cut by a vertical plane including the optical axis of the lamp unit 16 as viewed from the left side of the lamp. When the vehicle headlamp 10 is mounted on the vehicle, the vehicle headlamps 10 formed symmetrically with each other are provided on the vehicle left front and right front, respectively. FIG. 1 shows the configuration of the left or right vehicle headlamp 10.

  The lamp body 12 is formed in a box shape having an opening. The translucent cover 14 is formed in a bowl shape with translucent resin or glass. The translucent cover 14 is attached to the opening of the lamp body 12 at the edge. In this way, a lamp chamber is formed in an area covered by the lamp body 12 and the translucent cover 14.

  A lamp unit 16 including a light source is disposed in the lamp chamber. The translucent cover 14 transmits light from the lamp unit 16 so as to irradiate light forward of the lamp. The lamp unit 16 is fixed to the lamp body 12 by aiming screws (not shown). The lamp unit 16 includes a projection lens 18, a support member 20, a reflector 24, a light emitting module 22, and a heat sink 26. The projection lens 18 is a plano-convex aspheric lens having a convex front surface and a flat rear surface, and projects a light source image formed on the rear focal plane to the front of the lamp as an inverted image. The support member 20 supports the projection lens 18, the light emitting module 22, and the heat sink 26.

  The light emitting module 22 includes a substrate 28 and a light emitting element 30. The light emitting element 30 is configured by an LED which is a semiconductor light emitting element. In addition, the light emitting element 30 may be comprised by light emitting elements other than LED, and it replaces with the light emitting element 30, and other light sources, such as a discharge lamp and an incandescent lamp, may be used. The light emitting module 22 is disposed so that the light emitting element 30 mainly emits light upward.

  The reflector 24 reflects the light from the light emitting element 30 to form a light source image on the rear focal plane of the projection lens 18. Thus, the reflector 24 and the projection lens 18 function as an optical member that condenses the light emitted from the light emitting element 30 toward the front of the lamp. The heat sink 26 is formed of a heat radiating material having high heat radiating properties such as aluminum, and is attached to the rear surface of the support member 20. The heat sink 26 has a large number of heat radiation fins, and mainly dissipates heat generated by the light emitting element 30.

  The support member 20 may be formed with a shade (not shown). The vehicular headlamp 10 is used as a low beam light source, and the shade blocks a part of the light emitted from the light emitting element 30 and reflected by the reflector 24, so that a cut-off line in the low beam light distribution pattern is formed in front of the vehicle. Form. Since the low beam light distribution pattern is known, the description thereof is omitted. Therefore, the vehicle headlamp 10 functions as a low beam light source. The vehicle headlamp 10 may be used as a high beam light source.

  Here, when a lot of snow adheres to the translucent cover 14, it is difficult to melt snow only with the amount of heat generated by the light emitting element 30. For this reason, a heater 40 is provided in the lamp chamber of the vehicle headlamp 10. The heater 40 is provided separately from the light emitting element 30 which is a lamp light source as a heat source for melting snow. In the first embodiment, a PTC (Positive Temperature Coefficient) heater is used as the heater 40. Since the resistance value of the PTC heater increases and the current is controlled at a certain temperature, the PTC heater can generate heat quickly using electric power efficiently. Moreover, by using a PTC heater, it is possible to generate heat appropriately without performing feedback control by a temperature sensor. Needless to say, the heater 40 is not limited to a PTC heater. For example, a nichrome wire heater may be adopted as the heater 40. The heater 40 is disposed near the lower portion of the inner surface of the translucent cover 14 to be melted.

  In the first embodiment, a fan 42, which is a blowing means, and a duct 44 are further provided in the lamp chamber. The fan 42 is disposed below the heater 40. The fan 42 blows air upward along the inner surface of the translucent cover 14 through the heater 40. The duct 44 is disposed above the heater 40 so as to extend in parallel along the inner surface of the translucent cover 14, and guides the air heated by the heat of the heater 40 along the inner surface of the translucent cover 14. The duct 44 is made of a translucent resin. The duct 44 may be formed of other materials.

  The heater 40 is provided so as to be able to generate heat using electric power of a battery provided in the vehicle by turning on a headlamp heater switch provided in the vehicle compartment. On the other hand, the fan 42 also has a function of dissipating the heat generated by the light emitting element 30, and thus is provided to start air blowing when the lamp switch is turned on. For this reason, even when snow melting is not required, fogging of the translucent cover 14 can be suppressed.

  When the headlight heater switch is turned on, the air heated by the heater 40 is blown upward by the fan 42. Thereby, the air warmed along the inner surface of the translucent cover 14 is guided by the duct 44, and snow attached to the surface of the translucent cover 14 can be melted appropriately. The air that has passed through the duct 44 convects in the lamp chamber so as to pass around the heat sink 26 and return to the fan 42 again. This air convection can dissipate heat generated by the light emitting element 30 through the heat sink 26.

  The heater 40 and the fan 42 may be installed not only in the vicinity of the lower part of the inner surface of the translucent cover 14 but also on the left and right sides of the lamp chamber. Further, it is not necessary to melt snow on the entire surface of the translucent cover 14, and for example, the heater 40 and the fan 42 may be arranged so that snow can be melted only in a portion necessary for forming the light distribution pattern.

(Second Embodiment)
FIG. 2 is a diagram schematically showing the configuration of the vehicle headlamp 60 according to the second embodiment. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The vehicle headlamp 60 also includes a translucent cover 14, a lamp body 12, and a lamp unit 16. Also in the second embodiment, the vehicle headlamp 60 includes the heater 40 and the fan 42. However, in the vehicle headlamp 60, the heater 40 is disposed above the heat sink 26. The fan 42 is disposed below the heat sink 26. When the headlamp heater switch described above is turned on, the heater 40 starts to generate heat, and the fan 42 starts to blow upward so that air passes through the heat sink 26 and the heater 40.

  As a result, the air heated by passing through the heat sink 26 and the heater 40 flows downward along the inner surface of the translucent cover 14 and convects in the lamp chamber so as to return to the fan 42 again. By arranging the heater 40 in the vicinity of the heat sink 26 in this way, first, air can be blown relatively strongly to the inner surface of the translucent cover 14. For this reason, the snow adhering to the surface of the translucent cover 14 can be melted appropriately. Further, by configuring the air to circulate in the lamp chamber, the fan for dissipating the heat of the heat sink 26 can be eliminated, and the cost can be reduced as compared with the case where a fan is provided in each of the heat sink 26 and the heater 40. Can be suppressed. A fan for dissipating heat from the heat sink 26 may be provided separately from the fan 42.

(Third embodiment)
FIG. 3 is a diagram schematically showing the configuration of a vehicle headlamp 80 according to the third embodiment. Hereinafter, the same portions as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The vehicle headlamp 80 also includes a translucent cover 14, a lamp body 12, and a lamp unit 16. Also in the third embodiment, the vehicle headlamp 80 includes the heater 40 and the fan 42. The heater 40 is disposed near the lower portion of the inner surface of the translucent cover 14 to be melted. However, in the vehicle headlamp 80, the fan 42 is disposed below the heat sink 26. When the headlamp heater switch described above is turned on, the heater 40 starts to generate heat, and the fan 42 starts to blow upward so that air passes through the heat sink 26 and the heater 40.

  As a result, the air that has passed through the heat sink 26 flows below the inner surface of the translucent cover 14, and further passes through the heater 40, flows downward along the inner surface of the translucent cover 14, and returns to the fan 42 again. Convection through the lamp chamber. In this way, by configuring the air to flow from the fan 42 that dissipates heat from the heat sink 26 to the heater 40, the air can be blown relatively strongly to the heat sink 26. For this reason, it can avoid that the heat dissipation of the light emitting element 30 which falls by snow melting falls. Further, by configuring the air to circulate in the lamp chamber using the air blown from the fan 42 for dissipating the heat of the heat sink 26, the fan for the heater 40 can be eliminated. In addition, the cost can be reduced compared to the case where a fan is provided in each of the heaters 40. In addition to the fan 42, a fan that blows air directly onto the heater 40 may be provided.

(Fourth embodiment)
FIG. 4 is a diagram schematically showing the configuration of the vehicle headlamp 100 according to the fourth embodiment. Hereinafter, the same portions as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The vehicle headlamp 100 includes a lamp body 12, a translucent cover 14, and a lamp unit 110. The lamp unit 110 includes a lamp body 12, a reflector 24, a light emitting module 114, a shade 118, and a duct 119. The light emitting module 114 includes a light emitting element 120. The light emitting element 120 is configured by an LED that is a semiconductor light emitting element. In addition, the light emitting element 120 may be comprised by light emitting elements other than LED, and it replaces with the light emitting element 120, and other light sources, such as a discharge lamp and an incandescent lamp, may be used.

  The shade 118 has a plane including the lamp optical axis Ax1, and forms a cut-off line near the horizontal line of the low beam light distribution pattern. Note that the shape of the shade 118 is well known, and the description thereof is omitted.

  FIG. 5 is a perspective view showing a configuration of the light emitting module 114. The light emitting module 114 includes a package 130, a heat sink 132, an attachment 116, a fan 136, a cover 140, and a control circuit unit 142. The package 130 includes the light emitting element 120. The control circuit unit 142 controls lighting of the light emitting element 120. In the present embodiment, the control circuit unit 142 includes a printed wiring board and electrical components and elements mounted on the printed wiring board.

  The heat sink 132 is formed of a heat dissipation material having high heat dissipation properties such as aluminum. The heat sink 132 includes heat radiating fins 132 a and dissipates heat generated by the light emitting element 120 and the control circuit unit 142. The heat sink 132 may be separated into a first heat sink that dissipates heat from the light emitting element 120 and a second heat sink that dissipates heat from the control circuit unit 142. The attachment 116 is attached to the upper surface of the heat sink 132 to attach the package 130 to the upper surface of the heat sink 132.

  The heat radiation fins 132 a of the heat sink 132 are provided below the heat sink 132. The radiation fins 132a are provided so as to extend in a direction parallel to the lamp optical axis Ax1. For this reason, the radiation fin 132a also functions as a guide for guiding the air blown to the heat sink 132 in a direction parallel to the lamp optical axis Ax1. The fan 136 is attached to the heat sink 132 below the heat radiating fins 132a so that air can be blown to the heat radiating fins 132a to dissipate heat generated by the light emitting element 120. In addition, the lamp rear side of the radiation fin 132a may be shielded. Thereby, the air sprayed on the heat sink 132 is guided forward of the lamp by the heat radiating fins 132a.

  A fixed connector 117 is integrally fixed to the attachment 116 by integral molding with resin. The fixed connector 117 is provided so that a wire connector can be coupled thereto. Further, the attachment 116 is provided with a circuit accommodating portion that is recessed downward to accommodate the control circuit portion 142. The control circuit unit 142 is housed in this circuit housing unit. After the control circuit unit 142 is accommodated, the cover 140 is attached to the attachment 116.

  In the control circuit unit 142, the length in the direction perpendicular to the lamp optical axis Ax1 is longer than the length in the direction parallel to the lamp optical axis Ax1. The attachment 116 is attached to the heat sink 132, whereby the package 130 is sandwiched between the attachment 116 and the heat sink 132, and the package 130 is attached. As described above, the light emitting module 114 is configured integrally with the light emitting element 120 that is a light source and the control circuit unit 142 that controls the lighting of the light emitting element 120. The heat sink 132 dissipates not only the light emitting element 120 but also the heat generated by the control circuit unit 142.

  One fixed connector 117 is provided on each of the left and right side surfaces of the attachment 116. In the region below the upper surface of the shade 118, the fixed connector 117 is provided with a coupling portion for coupling the wire connector so that the fixed connector 117 can be moved vertically upward to couple the wire connector. Thereby, it can avoid that the flow of air is inhibited by the fixed connector 117.

  Returning to FIG. The lamp unit 110 is provided with a duct 119. The duct 119 guides the air that is blown and discharged to the heat radiation fins 132a of the heat sink 132 by the fan 136 to the front of the lamp. The duct 119 is fixed to the end of the shade 118 on the projection lens 18 side. The duct 119 is inclined so as to descend from the end of the shade 118 as it approaches the projection lens 18 and extends to the vicinity of the lower end of the projection lens 18.

  The duct 119 has an opening near the lower end of the projection lens 18. A heater 40 is attached to the opening. Therefore, the heater 40 is disposed at a position closer to the translucent cover 14 than the light emitting element 120, and the duct 119 extends so as to guide air from the fan 136 to the heater 40.

  As a result, the air that has passed through the heat sink 132 is guided to the duct 119, warmed through the heater 40 provided near the translucent cover 14, and discharged. When a PTC heater is used as the heater 40, a configuration for forcibly blowing air to the PTC heater using the duct 119 as in the present embodiment is suitable. If the heat generated by the heater 40 cannot be efficiently transferred to the air, the temperature of the air that convects the inner surface of the translucent cover 14 is lowered. Further, the heater 40 may stop generating heat due to its own temperature rise. The discharged air flows upward along the inner surface of the translucent cover 14. Thereby, the snow adhering to the translucent cover 14 can be melted. The air that has reached the upper side of the translucent cover 14 convects in the lamp chamber so as to return to the fan 136 again.

  As described above, even in the vehicle headlamp 100 having the light emitting module 114 in which the light emitting element 120 and the control circuit unit 142 are integrally formed, snow attached to the surface of the translucent cover 14 using the heater 40 is appropriately used. Can be melted into In the fourth embodiment, not only the heat of the light emitting element 120 but also the heat of the control circuit unit 142 can be used for melting snow. For this reason, compared with the case where the control circuit part 142 is provided outside the lamp chamber, the snow melting effect can be enhanced.

  The vehicle headlamp 100 described above may be used as a headlamp for an electric vehicle. In the case of a conventional gasoline vehicle, a radiator or an engine is usually present near the headlight installation location. On the other hand, in the case of an electric vehicle, there are a motor and an inverter near the headlight installation location, but since the amount of heat generation is smaller than that of a radiator or engine, the environmental temperature of the headlight installation location is relatively low. The vehicle headlamp 100 according to the present embodiment is particularly suitable as a headlamp for an electric vehicle because it can melt snow appropriately even if the environmental temperature at the installation location is low.

  The present invention is not limited to the above-described embodiments, and an appropriate combination of the elements of each embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and embodiments to which such modifications are added can also be included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 Vehicle headlamp, 12 Lamp body, 14 Translucent cover, 16 Lamp unit, 18 Projection lens, 20 Support member, 22 Light emitting module, 24 Reflector, 26 Heat sink, 28 Substrate, 30 Light emitting element, 40 Heater, 42 Fan 44 duct, 60, 80, 100 vehicle headlamp, 110 lamp unit, 114 light emitting module, 116 attachment, 117 fixed connector, 118 shade, 119 duct, 120 light emitting element, 130 package, 132 heat sink, 132a heat radiation fin, 136 fan, 140 cover, 142 control circuit part.

Claims (5)

A light-transmitting cover that forms at least a part of a lamp chamber that houses the lamp light source, and transmits light from the lamp light source to irradiate light in front of the lamp;
A heat source provided separately from the lamp light source;
A fan that convects the heat of the heat source into the lamp chamber;
A vehicular lamp characterized by comprising:   The vehicular lamp according to claim 1, wherein the heat source is a PTC (Positive Temperature Coefficient) heater.   The vehicular lamp according to claim 1, further comprising a duct that guides air in the lamp chamber so as to convect heat of the heat source. A duct for guiding the air blown out by the fan;
The fan is disposed in the vicinity of the lamp light source so as to dissipate heat generated by the lamp light source.
The heat source is disposed at a position closer to the translucent cover than the lamp light source,
4. The vehicular lamp according to claim 1, wherein the duct extends so as to guide air from the fan to the heat source. 5.   The vehicular lamp according to claim 1, wherein the vehicular lamp is used as a headlamp of an electric vehicle.

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