Vehicle lamp

Abstract

To provide a vehicle lamp capable of efficiently circulating an airflow ventilated by a fan along an inner surface of an outer lens.SOLUTION: A vehicle lamp comprises: a lamp body 4 composed of a housing 2 with an open front, and an outer lens 3 covering the opening of the housing 2; a light source unit 5 that is arranged inside the lamp body 4, and emits light forward; an extension 6 surrounding the front of the light source unit 5; a fan 8 that generates an airflow to cool a heat generating unit 7 of the light source unit 5; and a duct 9 that guides the airflow F ventilated by the fan 8 between the light source unit 5 and the extension 6.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle lamp. [Background technology]

[0002] Conventionally, in vehicle lighting fixtures such as vehicle headlights (headlamps), a breathing hole has been provided in the lamp body, which is composed of a housing with an opening at the front and an outer lens that covers the opening of the housing, and ventilation is carried out through this breathing hole, allowing moisture inside the lamp body to be released to the outside and preventing fogging on the inner surface of the outer lens.

[0003] In recent years, the number of vehicle lighting fixtures using light-emitting diodes (LEDs) as light sources has been gradually increasing as LEDs have become brighter and cheaper. LEDs have the advantages of a long lifespan and low power consumption.

[0004] On the other hand, when LEDs get too hot, their light-emitting efficiency decreases and their lifespan shortens, so it is necessary to use a heat sink or cooling fan to efficiently dissipate the heat generated by the LED to the outside.

[0005] However, in vehicle lighting fixtures that use LEDs as the light source, the amount of infrared light emitted, which is absorbed by the outer lens and moisture and turns into heat, is smaller than that of conventional light sources such as halogen lamps and HID lamps, making the inner surface of the outer lens more susceptible to fogging.

[0006] Therefore, when the light source is turned on, the airflow (wind) generated by the cooling fan described above is circulated along the inner surface of the outer lens to prevent fogging on the inner surface of the outer lens (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2017-228417 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the above-mentioned conventional vehicle lamp, the airflow generated by the cooling fan must pass through a narrow gap within the lamp body before reaching the inner surface of the outer lens.

[0009] As a result, there is a large pressure loss when the airflow travels from the cooling fan to the inner surface of the outer lens, making it difficult to efficiently circulate the airflow along the inner surface of the outer lens.

[0010] The present invention has been proposed in consideration of the above-mentioned conventional circumstances, and aims to provide a vehicle lamp that enables the airflow blown by the fan to be efficiently circulated along the inner surface of the outer lens. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention provides the following means. [1] A lamp body comprising a housing with an opening at the front and an outer lens covering the opening of the housing; a light source unit disposed inside the lamp body and emitting light forward; an extension that covers the periphery of the front of the light source unit; a fan that generates an airflow for cooling a heat-generating portion of the light source unit; a duct that guides the airflow blown by the fan to between the light source unit and the extension. [2] The vehicle lamp according to [1], wherein the duct has an outlet for ejecting airflow from between the light source unit and the extension. [3] The vehicle lamp according to [2], wherein the outlet is provided at a position surrounding the periphery in front of the light source unit. [4] The vehicle lamp according to [1], wherein the duct has a passage opening through which light emitted from the light source unit passes. [5] The fan is disposed in a position facing the heat generating portion, The duct surrounds the heat generating portion and has a shape that guides the airflow blown by the fan to between the light source unit and the extension. [6] The vehicle lamp according to [1], wherein the duct is provided integrally with the light source unit. [7] The extension is arranged to divide the inside of the lamp body into a space on the housing side and a space on the outer lens side, The vehicle lamp described in [1] is characterized in that the air flow that flows out from the duct into the space on the outer lens side flows along the inner surface of the outer lens and then flows into the space on the housing side. [8] The extension has an opening that communicates a space on the housing side with a space on the outer lens side, The vehicle lamp according to [7], wherein the opening is disposed on at least one end side in the direction in which the extension extends. [9] The light source unit has a light source, The vehicle lamp according to [1], wherein the heat generating portion is the light source.

[10] The vehicle lamp according to [9], wherein the light source unit includes a heat sink for dissipating heat generated by the light source. [Effects of the Invention]

[0012] As described above, the present invention provides a vehicle lamp that allows the airflow blown by the fan to circulate efficiently along the inner surface of the outer lens. [Brief explanation of the drawings]

[0013] [Figure 1]1 is a cross-sectional view showing the configuration of a vehicle lamp according to a first embodiment of the present invention. [Figure 2] 2 is a front view of the main part of the vehicle lamp shown in FIG. 1. FIG. [Figure 3] 2 is a front view illustrating an example of the shape of the outlet of the duct shown in FIG. 1. FIG. [Figure 4] FIG. 5 is a cross-sectional view showing the configuration of a vehicle lamp according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view showing the configuration of a vehicle lamp according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional view showing the configuration of a vehicle lamp according to a fourth embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional view showing the configuration of a vehicle lamp according to a fifth embodiment of the present invention. [Figure 8] FIG. 10 is a cross-sectional view showing the configuration of a vehicle lamp according to a sixth embodiment of the present invention. [Figure 9] FIG. 11 is a cross-sectional view showing the configuration of a vehicle lamp according to a seventh embodiment of the present invention. [Figure 10] FIG. 13 is a side perspective view showing the configuration of a light source unit and a duct provided in a vehicle lamp according to an eighth embodiment of the present invention. [Figure 11] 11 is a front perspective view showing the configuration of a light source unit and a duct provided in the vehicle lamp shown in FIG. 10. FIG. [Figure 12] 11 is a front view showing the configuration of a light source unit and a duct provided in the vehicle lamp shown in FIG. [Figure 13] 11 is a bottom view showing the configuration of a light source unit and a duct provided in the vehicle lamp shown in FIG. 10. FIG. [Figure 14] 11 is a vertical cross-sectional view showing the configuration of a light source unit and a duct provided in the vehicle lamp shown in FIG. 10. FIG. [Figure 15] 11 is a cross-sectional view showing the configuration of a light source unit and a duct provided in the vehicle lamp shown in FIG. 10. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, the dimensions of the components may be shown at different scales to make them easier to see, and the dimensional ratios of the components may not necessarily be the same as in reality.

[0015] In addition, in the drawings shown below, an XYZ Cartesian coordinate system is set up, with the X-axis direction representing the front-to-rear direction (length direction) of the vehicle lamp, the Y-axis direction representing the left-to-right direction (width direction) of the vehicle lamp, and the Z-axis direction representing the up-to-down direction (height direction) of the vehicle lamp.

[0016] (First embodiment) First, as a first embodiment of the present invention, a vehicle lamp 1A shown in, for example, FIGS. 1 to 3 will be described.

[0017] Fig. 1 is a cross-sectional view showing the configuration of the vehicle lamp 1A, Fig. 2 is a view of the main part of the vehicle lamp 1A as seen from the front side, and Fig. 3 is a front view showing an example of the shape of the outlet 9b of the duct 9.

[0018] The vehicle lighting fixture 1A of this embodiment is an application of the present invention to a vehicle headlamp mounted, for example, at both corners of the front end of a vehicle (not shown) (in this embodiment, the corner on the right front end).

[0019] Specifically, as shown in Figures 1 and 2, this vehicle lamp 1A has a lamp body 4 made up of a housing 2 with an open front and a transparent outer lens 3 that covers the opening of the housing 2. The lamp body 4 is arranged with its longitudinal direction aligned with the vehicle width direction (horizontally elongated).

[0020] In the lamp body 4, the outer lens 3 has an inclined shape that is tilted in a direction that the outer side is more retracted than the inner side in the vehicle width direction, in accordance with the slanted shape given to the corner portion on the front end side of the vehicle.

[0021] The outer lens 3 is not limited to such an inclined shape, but may be curved so that the outer side is more receding than the inner side in the vehicle width direction. The shape of the lamp body 4 can be changed as appropriate to suit the design of the vehicle, etc.

[0022] The vehicle lamp 1A of this embodiment comprises a light source unit 5 arranged inside the lamp body 4, an extension 6 that covers the front periphery of the light source unit 5, a fan 8 that blows air to cool a heat generating portion 7 that generates heat when the light source unit 5 is turned on, and a duct 9 that circulates the airflow F blown by the fan 8.

[0023] The light source unit 5 includes a light source 10, for example, a light-emitting diode (LED) that emits white light, a projection lens 11 that projects the light emitted from the light source 10 forward, a substrate 12 on one side of which the light source 10 is mounted (the front side in this embodiment), and a heat sink 13 that dissipates heat emitted by the light source 10 while in contact with the other side of the substrate 12 (the rear side in this embodiment).

[0024] The light source unit 5 is not necessarily limited to this configuration, and may be configured, for example, to have a reflector (not shown) that reflects the light emitted from the light source 10 forward, and the light reflected by this reflector is projected forward by the projection lens 11.

[0025] Furthermore, the light source unit 5 may be one that forms a low beam light distribution pattern including a cutoff line at the upper end as a passing beam (low beam) by inverting and projecting the light source image defined by the front end of the shade using a projection lens, or one that forms a high beam light distribution pattern above the low beam light distribution pattern as a driving beam (high beam) by projecting light emitted from the light source using a projection lens, or one in which the light source unit that forms the low beam light distribution pattern and the light source unit that forms the high beam light distribution pattern are integrated.

[0026] In this embodiment, the heat generating unit 7 is a light source 10. The heat generating unit 7 may also include, for example, a drive circuit (not shown) that drives the light source 10, a sensor transmitter / receiver such as a millimeter wave radar or LiDAR, a driver for the sensor, etc.

[0027] The heat sink 13 has a plurality of fins 13a that protrude rearward. The fins 13a are flat plates that extend in the left-right direction and are aligned in the up-down direction. The front of the heat sink 13 is thermally connected to the other surface of the substrate 12 via a heat transfer member (not shown). The heat sink 13 is disposed inside the duct 9 so that the airflow F blown by the fan 8 flows left-right through the gaps between the plurality of fins 13a.

[0028] The fan 8 is disposed facing the inside of the duct 9 from the rear side of the duct 9 at a position opposite the heat sink 13. The fan 8 is provided integrally with the duct 9.

[0029] As for the fan 8, any type of blower may be used, such as an axial fan, a sirocco fan, or a centrifugal fan.

[0030] The duct 9 surrounds the heat sink 13 and has a shape that guides the airflow F blown by the fan 8 to between the light source unit 5 and the extension 6. The duct 9 is provided integrally with the light source unit 5.

[0031] The duct 9 also has an intake port 9a at its rear that takes in the airflow F blown by the fan 8, an outlet port 9b at its front that ejects the airflow F from between the light source unit 5 and the extension 6, and an outlet port 9c that allows light from the light source unit 5 to pass through.

[0032] The intake port 9a is provided at a position facing the heat sink 13 on the rear side of the duct 9 and opens. The fan 8 is attached to the intake port 9a. The outlet port 9b opens in a circular ring shape in front view at a position surrounding the front periphery of the light source unit 5. The passage port 9c is located on the inner periphery of the outlet port 9b and opens in a circular shape in front view.

[0033] The light source unit 5 is disposed so that the projection lens 11 faces forward through the passage opening 9c. In this embodiment, the passage opening 9c is larger than the outer diameter of the projection lens 11.

[0034] The vehicle lamp 1A of this embodiment is equipped with an optical axis adjustment mechanism that adjusts the optical axis of light emitted forward from the light source unit 5. In this embodiment, the optical axis adjustment mechanism supports the light source unit 5 integrally with the duct 9 so that it can tilt freely. Note that the optical axis adjustment mechanism can also support the light source unit 5 separately from the duct 9 so that it can tilt freely.

[0035] In the vehicle lighting fixture 1A equipped with an optical axis adjustment mechanism, the optical axis of the light emitted from the light source unit 5 toward the front of the vehicle can be adjusted by an aiming operation that adjusts the left-right and up-down tilt of the light source unit 5.

[0036] In addition, after detecting the vehicle's longitudinal tilt, it is possible to correct fluctuations in the optical axis due to changes in the vehicle's posture by performing a leveling operation that automatically adjusts the optical axis of the light emitted from the light source unit 5 toward the front of the vehicle in the vertical direction.

[0037] The extension 6 is made of a colored (e.g., black or silver) light-blocking member, and is attached to the lamp body 4 via a fastening structure such as a mating claw or a screw. The extension 6 covers the periphery of the front side of the light source unit 5, thereby blocking light leaking from the light source unit 5. The extension 6 also plays a role in the design of the vehicle lamp 1A.

[0038] The extension 6 is arranged to divide the inside of the lamp body 4 into a space K1 on the outer lens 3 side (front side) and a space K2 on the housing 2 side (rear side). The extension 6 has an opening 6a that exposes the outlet 9b and passage opening 9c of the duct 9 forward in the light emission direction of the light source unit 5.

[0039] The opening 6a is located on the outer periphery of the outlet 9b and has a circular opening in a front view. In this embodiment, the opening 6a is larger in outer diameter than the outlet 9b. The duct 9 is disposed between the projection lens 11 of the light source unit 5 and the opening 6a of the extension 6 so that the outlet 9b faces forward.

[0040] The extension 6 has openings 6b and 6c that communicate between a space K1 on the outer lens 3 side and a space K2 on the housing 2 side. The openings 6b and 6c are open at one end side and the other end side in the longitudinal direction in which the extension 6 extends (in this embodiment, the inner and outer ends in the vehicle width direction).

[0041] In the vehicle lamp 1A of this embodiment having the above-described configuration, the airflow F blown by the fan 8 is ejected from the outlet 9b of the duct 9, and flows out to the space K1 on the front side of the extension 6, i.e., the outer lens 3 side.

[0042] The airflow F that flows into the space K1 on the outer lens 3 side flows along the inner surface of the outer lens 3, and then flows into the rear side of the extension 6, i.e., the space K2 on the housing 2 side, through the openings 6b, 6c at both ends of the extension 6 in the longitudinal direction.

[0043] The airflow F that has flowed into the space K2 on the housing 2 side is again drawn in by the fan 8 through the intake port 9a of the duct 9, and is thereby repeatedly circulated inside the lighting body 4.

[0044] As described above, in the vehicle lamp 1A of this embodiment, the airflow F sent by the fan 8 through the duct 9 can be efficiently circulated along the inner surface of the outer lens 3. This makes it possible to prevent fogging on the inner surface of the outer lens 3.

[0045] Furthermore, in the vehicle lamp 1A of this embodiment, even when the light source unit 5 is not lit, the airflow F inside the lamp body 4 can be circulated by blowing air with the fan 8.

[0046] As a result, in the vehicle lamp 1A of this embodiment, it is possible to prevent the inner surface of the outer lens 3 from fogging up, regardless of whether the light source unit 5 is lit or not.

[0047] For example, in situations where fogging is predicted, it is possible to operate the fan 8 preventively based on information about the external environment obtained from temperature sensors, barometric pressure sensors, etc., specifically changes in temperature, barometric pressure, altitude, etc.

[0048] Furthermore, in the vehicle lamp 1A of this embodiment, the temperature of the airflow F rises due to the heat radiated from the heat generating portion 7. This reduces the relative humidity in the space K1 inside the lamp body 4, particularly on the outer lens 3 side, and raises the temperature of the outer lens 3, thereby improving the anti-fogging effect on the inner surface of the outer lens 3.

[0049] As described above, in the vehicle lamp 1A of this embodiment, by using the above-described duct 9, it is possible to efficiently guide the airflow F blown by the fan 8 to between the light source unit 5 and the extension 6. This allows the airflow F to be ejected from the outlet 9b of the duct 9 toward the outer lens 3 in front, making it possible to reduce the pressure loss of the airflow F generated by the fan 8 until it reaches the inner surface of the outer lens 3. It is also possible to increase the amount of airflow F ejected from the outlet 9b of the duct 9 toward the outer lens 3.

[0050] In addition, by providing the outlet 9b of the duct 9 at a position surrounding the front side of the light source unit 5, it is possible to eject the airflow F toward the outer lens 3 in front without the duct 9 obstructing the light irradiated forward from the light source unit 5.

[0051] Furthermore, even when adjusting the optical axis of the light emitted from the light source unit 5 toward the front of the vehicle using the above-mentioned optical axis adjustment mechanism, the light source unit 5 and the duct 9 tilt together, so that the airflow F can be ejected from the outlet 9b of the duct 9 toward the outer lens 3 in front without impeding the light distribution and optical axis adjustment.

[0052] The present invention is not necessarily limited to the configuration of the vehicle lamp 1A described above, and various modifications can be made without departing from the spirit of the present invention.

[0053] Specifically, the shape of the outlet 9b of the duct 9 is not limited to the above-mentioned one, and the outlet 9b may have any of the shapes shown in Figs. 3(A) to 3(C), for example.

[0054] 3(A) has a configuration in which a plurality of outlets 9b are arranged in a circumferential direction. In this modification, the direction of the plurality of outlets 9b can be changed to arbitrarily set the direction in which the airflow F is ejected. In addition, by changing the ratio of the openings of the plurality of outlets 9b, the flow rate and volume of the airflow F ejected from each outlet 9b can be arbitrarily set.

[0055] 3(B) is configured such that the outlets 9b are provided partially in the circumferential direction. By providing the outlets 9b partially as in this modified example, it is possible to increase the flow velocity of the airflow F ejected from the outlets 9b compared to when the outlets are provided all around the circumference.

[0056] 3(C) shows a duct 9 in which the circumferential width of the outlet 9b is changed. In this modification, the opening area of the outlet 9b in the left-right direction is increased. This makes it possible to increase the flow rate of the airflow F ejected in the left-right direction from the outlet 9b.

[0057] 3(A) to 3(C), the outlet 9b may be configured so that a plurality of small slits or holes are provided on the tip side of the duct 9. In this way, the shape, number, opening area, etc. of the outlet 9b can be appropriately changed in consideration of the anti-fogging effect, cooling effect, appearance, etc.

[0058] For example, areas of the outer lens 3 that are prone to fogging may occur due to factors such as the degree of wind blowing when the lamp is traveling and the heat source inside the lamp body 4. By improving the flow rate and flow speed of the airflow F that is blown toward these areas that are prone to fogging, it is possible to efficiently prevent fogging. Furthermore, since these areas are areas where there is a large temperature difference between the outside and inside of the lamp body 4, blowing the airflow F toward these areas that are prone to fogging can be expected to improve the cooling effect of the heat-generating part 7 by lowering the temperature of the airflow F that returns to the space K2 on the housing 2 side.

[0059] Furthermore, in this embodiment, by providing the outlets 9b around the front side of the light source unit 5, the flow velocity of the airflow F is improved in the region of the outer lens 3 that overlaps with the optical path of the light emitted from the light source unit 5. This makes it possible to more effectively suppress the occurrence of fogging on the inner surface of the outer lens 3, which would hinder the light distribution by the light source unit 5.

[0060] (Second embodiment) Next, a vehicle lamp 1B shown in FIG. 4 will be described as a second embodiment of the present invention.

[0061] 4 is a cross-sectional view showing the configuration of the vehicle lamp 1B. In the following description, the same parts as those in the vehicle lamp 1A will not be described and will be denoted by the same reference numerals in the drawings.

[0062] As shown in FIG. 4, the vehicular lamp 1B of this embodiment has a configuration in which the length of the tip end side of the duct 9 is shorter than that of the vehicular lamp 1A shown in FIG.

[0063] In this configuration, the duct 9 is less visible from the opening 6a, and the external appearance and design of the lamp are less affected. Other than that, the configuration is basically the same as that of the above-described vehicle lamp 1A.

[0064] In the vehicle lamp 1B of this embodiment, it is possible to efficiently circulate the airflow F sent by the fan 8 through the duct 9 along the inner surface of the outer lens 3 while minimizing the impact on the design of the lamp. This makes it possible to prevent the inner surface of the outer lens 3 from fogging up.

[0065] (Third embodiment) Next, a vehicle lamp 1C shown in FIG. 5 will be described as a third embodiment of the present invention.

[0066] 5 is a cross-sectional view showing the configuration of the vehicle lamp 1C. In the following description, the same parts as those in the vehicle lamp 1A will not be described and will be denoted by the same reference numerals in the drawings.

[0067] As shown in Fig. 5, the vehicle lamp 1C of this embodiment has a configuration in which the length of the tip end of the duct 9 is longer than that of the vehicle lamp 1A shown in Fig. 1. In this embodiment, the tip end of the duct 9 is located at a position that protrudes forward beyond the opening 6a of the extension 6.

[0068] In this configuration, the distance from the outlet 9b of the duct 9 to the outer lens 3 can be shortened, and it is possible to improve the flow speed of the airflow F in the vicinity of the outer lens 3. Other than that, the configuration is basically the same as that of the above-described vehicle lamp 1A.

[0069] Therefore, in the vehicle lamp 1C of this embodiment, similar to the vehicle lamp 1A, the airflow F sent by the fan 8 through the duct 9 can be efficiently circulated along the inner surface of the outer lens 3. This makes it possible to prevent the inner surface of the outer lens 3 from fogging up.

[0070] (Fourth embodiment) Next, a vehicle lamp 1D shown in FIG. 6 will be described as a fourth embodiment of the present invention.

[0071] 6 is a cross-sectional view showing the configuration of the vehicle lamp 1D. In the following description, the same parts as those in the vehicle lamp 1A will not be described and will be denoted by the same reference numerals in the drawings.

[0072] 6, the vehicle lamp 1D of this embodiment is configured such that the direction of the airflow F ejected from the outlet 9b of the duct 9 is changed as desired. In this embodiment, the tip end of the duct 9 is curved diagonally forward so that a relatively large amount of the airflow F is ejected toward one side in the longitudinal direction in which the extension 6 extends (the inner side in the vehicle width direction).

[0073] With this configuration, it is possible to increase the airflow F1 flowing from the outlet 9b of the duct 9 toward the opening 6b on one side of the extension 6 relatively to the airflow F2 flowing toward the opening 6c on the other side of the extension 6 (F1>F2). This increases the airflow F1 flowing along the inner surface of the outer lens 3 from the outlet 9b toward the opening 6b on one side, thereby improving the anti-fogging effect particularly in the vicinity of the area through which the airflow F1 flows. Other than that, it has basically the same configuration as the above-described vehicle lamp 1A.

[0074] Therefore, in the vehicle lamp 1D of this embodiment, similarly to the vehicle lamp 1A, the airflow F sent by the fan 8 through the duct 9 can be efficiently circulated along the inner surface of the outer lens 3. This makes it possible to prevent the inner surface of the outer lens 3 from fogging up.

[0075] In addition, in the present embodiment, by reversing the direction of the jet outlet 9b of the duct 9, the airflow F2 directed toward the opening 6c on the other side of the extension 6 can be relatively increased (F1 < F2) compared to the airflow F1 directed from the jet outlet 9b of the duct 9 toward the opening 6b on one side of the extension 6. Furthermore, it is also possible to reverse the left and right directions of the jet outlet 9b of the duct 9.

[0076] (Fifth Embodiment) Next, as a fifth embodiment of the present invention, for example, a vehicle lamp 1E shown in FIG. 7 will be described.

[0077] Note that FIG. 7 is a cross-sectional view showing the configuration of the vehicle lamp 1E. In the following description, the parts equivalent to the vehicle lamps 1A and 1D described above will be omitted from the description and the same reference numerals will be given in the drawings.

[0078] As shown in FIG. 7, the vehicle lamp 1E of the present embodiment has a configuration in which, in addition to the configuration of the vehicle lamp 1D, components 50 that require cooling are arranged in the space K2 on the housing 2 side where the airflow F1 flows in from the opening 6b on one side.

[0079] The component 50 is, for example, a control circuit that controls the lighting and extinguishing of the light source unit 5, a sensor body such as a millimeter-wave radar or Lidar, and a control device.

[0080] In the case of this configuration, by increasing the airflow F1 flowing in from the opening 6b on one side described above, it is possible to efficiently cool the component 50 with the airflow F1. In addition, the airflow F is warmed by the heat transfer from the component 50, and the effect of preventing fogging inside the outer lens 3 is improved. Otherwise, it has basically the same configuration as the vehicle lamp 1D described above.

[0081] Therefore, in the vehicle lamp 1E of this embodiment, similarly to the vehicle lamps 1A and 1D, the airflow F sent by the fan 8 through the duct 9 can be efficiently circulated along the inner surface of the outer lens 3. This makes it possible to prevent the inner surface of the outer lens 3 from fogging up.

[0082] (Sixth embodiment) Next, a vehicle lamp 1F shown in FIG. 8 will be described as a sixth embodiment of the present invention.

[0083] 8 is a cross-sectional view showing the configuration of the vehicle lamp 1F. In the following description, the same parts as those in the vehicle lamp 1A will not be described and will be denoted by the same reference numerals in the drawings.

[0084] 8, the vehicle lamp 1F of this embodiment has a configuration in which the sizes of an opening 6b on one side and an opening 6c on the other side of the extension 6 are changed arbitrarily. In this embodiment, the opening 6b on one side of the extension 6 is relatively larger than the opening 6c on the other side.

[0085] With this configuration, it is possible to increase the airflow F1 flowing from the outlet 9b of the duct 9 toward the opening 6b on one side of the extension 6 relatively to the airflow F2 flowing toward the opening 6c on the other side of the extension 6 (F1>F2). This increases the airflow F1 flowing along the inner surface of the outer lens 3 from the outlet 9b toward the opening 6b on one side, thereby improving the anti-fogging effect particularly in the vicinity of the area through which the airflow F1 flows. Other than that, it has basically the same configuration as the above-described vehicle lamp 1A.

[0086] Therefore, in the vehicle lamp 1F of this embodiment, similarly to the vehicle lamp 1A, the airflow F sent by the fan 8 through the duct 9 can be efficiently circulated along the inner surface of the outer lens 3. This makes it possible to prevent the inner surface of the outer lens 3 from fogging up.

[0087] In addition, in the present embodiment, by making the opening 6c on the other side of the extension 6 relatively larger than the opening 6b on one side of the extension 6, the airflow F2 directed toward the opening 6c on the other side of the extension 6 can be relatively increased (F1 < F2) compared to the airflow F1 directed from the jet outlet 9b of the duct 9 toward the opening 6b on one side of the extension 6.

[0088] (Seventh Embodiment) Next, as a seventh embodiment of the present invention, a vehicle lamp 1G shown in FIG. 9, for example, will be described.

[0089] Note that FIG. 9 is a cross-sectional view showing the configuration of the vehicle lamp 1G. In the following description, the description of parts equivalent to those of the vehicle lamp 1A will be omitted, and the same reference numerals will be used in the drawings.

[0090] As shown in FIG. 9, the vehicle lamp 1G of the present embodiment has a peripheral wall portion 14 that restricts the gap around the opening 6a of the extension 6 and the duct 9. The peripheral wall portion 14 is provided so as to project rearward along the periphery of the duct 9 from around the opening 6a of the extension 6. Otherwise, it has basically the same configuration as the vehicle lamp 1A.

[0091] In this configuration, by providing the peripheral wall portion 14 that restricts the above-described gap, the flow path of the gap between the duct 9 and the extension 6 is extended, and the resistance of this gap increases. As a result, the outflow of the airflow F from the opening 6a of the extension 6 to the space K2 on the housing 2 side can be restricted, and the flow rate of the airflow F to the space K1 on the outer lens 3 side can be increased. Otherwise, it has basically the same configuration as the vehicle lamp 1A.

[0092] Therefore, in the vehicle lamp 1G of the present embodiment, similarly to the vehicle lamp 1A, the airflow F blown by the fan 8 through the duct 9 can be efficiently circulated along the inner surface of the outer lens 3. As a result, it is possible to prevent the occurrence of fogging on the inner surface of the outer lens 3.

[0093] (Eighth embodiment) Next, a vehicle lamp 1H shown in, for example, FIGS. 10 to 15 will be described as an eighth embodiment of the present invention.

[0094] FIG. 10 is a side perspective view showing the configuration of the light source unit 5 and duct 9 provided in the vehicle lamp 1H. FIG. 11 is a front perspective view showing the configuration of the light source unit 5 and duct 9 provided in the vehicle lamp 1H. FIG. 12 is a front view showing the configuration of the light source unit 5 and duct 9 provided in the vehicle lamp 1H. FIG. 13 is a bottom view showing the configuration of the light source unit 5 and duct 9 provided in the vehicle lamp 1H. FIG. 14 is a vertical cross-sectional view showing the configuration of the light source unit 5 and duct 9 provided in the vehicle lamp 1H. FIG. 15 is a horizontal cross-sectional view showing the configuration of the light source unit 5 and duct 9 provided in the vehicle lamp 1H. In the following description, parts equivalent to those in the vehicle lamp 1A will not be described again and will be denoted by the same reference numerals in the drawings.

[0095] 10 to 15, the vehicle lamp 1H of this embodiment has a structure in which a fan 8 and a duct 9 are integrally attached to a light source unit 5 disposed inside a lamp body 4. Other than that, the vehicle lamp 1H has basically the same configuration as the above-described vehicle lamp 1A. Therefore, the lamp body 4 and the extension 6 are not shown in the drawings.

[0096] Specifically, the light source unit 5 has a light source 10 consisting of an LED that emits white light, a reflector 15 that reflects the light emitted from the light source 10 forward, a frame 16 on one side (the upper side in this embodiment) of which the light source 10 is mounted, and a heat sink 13 located on the other side (the lower side in this embodiment) of the frame 16 and that dissipates heat emitted by the light source 10.

[0097] The heat sink 13 has a plurality of fins 13a that protrude in a flat plate shape and are aligned in one direction (the front-to-rear direction in this embodiment) from the underside of the frame 16. The heat sink 13 is disposed inside the duct 9 so that the airflow F blown by the fan 8 circulates in the left-right direction through the gaps between the plurality of fins 13a.

[0098] The reflector 15 is made of a reflective material such as aluminum die-cast. The reflector 15 is attached to the upper surface of the frame 16 so as to cover the light source 10 from above with the front open. This makes the surface (inner surface) of the reflector 15 facing the light source 10 serve as the reflective surface 15a. The reflective surface 15a of the reflector 15 is curved so as to describe an elliptical surface with the center (light emitting point) of the light source 10 as one of its foci.

[0099] The fan 8 is disposed facing the inside of the duct 9 from the lower surface side of the duct 9 at a position opposite the heat sink 13. The fan 8 is also integrally attached to the lower surface side of the frame 16 via a bracket 17.

[0100] The duct 9 surrounds the heat sink 13 and has a shape that guides the airflow F sent by the fan 8 to between the light source unit 5 and the extension 6. The duct 9 is attached integrally to the frame 16.

[0101] In addition, the duct 9 has an outlet 9b on its front side that ejects airflow F from between the light source unit 5 and the extension 6, and a passage 9c located in front of the light source unit 5 that allows light from the light source unit 5 to pass through.

[0102] The outlet 9b opens in a circular ring shape in front view at a position surrounding the periphery of the front side of the light source unit 5. The passage opening 9c is located on the inner periphery side of the outlet 9b and opens in a circular shape in front view.

[0103] The duct 9 has an inner nozzle portion 9d that forms a passage port 9c, and an outer nozzle portion 9e that forms an ejection port 9b together with the inner nozzle portion 9d.

[0104] In the vehicle lamp 1H of this embodiment having the above-described configuration, the airflow F blown by the fan 8 is ejected from the outlet 9b of the duct 9, and flows out to the space K1 on the front side of the extension 6, i.e., the outer lens 3 side.

[0105] The airflow F that flows into the space K1 on the outer lens 3 side flows along the inner surface of the outer lens 3, and then flows into the back side of the extension 6, i.e., the space K2 on the housing 2 side, through the openings 6b, 6c at both ends of the extension 6 in the longitudinal direction.

[0106] The airflow F that has flowed into the space K2 on the housing 2 side is again drawn in by the fan 8 through the intake port 9a of the duct 9, and is thereby repeatedly circulated inside the lighting body 4.

[0107] As described above, in the vehicle lamp 1H of this embodiment, the airflow F sent by the fan 8 through the duct 9 can be efficiently circulated along the inner surface of the outer lens 3. This makes it possible to prevent fogging on the inner surface of the outer lens 3.

[0108] Therefore, in the vehicle lamp 1H of this embodiment, similarly to the vehicle lamp 1A, the airflow F sent by the fan 8 through the duct 9 can be efficiently circulated along the inner surface of the outer lens 3. This makes it possible to prevent the inner surface of the outer lens 3 from fogging up.

[0109] In the above embodiment, the duct 9 is configured not to block the light emitted from the light source unit 5, but it may also have an optical function. For example, in addition to the function of guiding the airflow F blown by the fan 8 to between the light source unit 5 and the extension 6, it may also have an optical function such as a reflector or shade, thereby preventing glare and improving the light distribution contrast.

[0110] The present invention is not necessarily limited to the first to eighth embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

[0111] Specifically, in the above first to eighth embodiments, the present invention is exemplified as being applied to a vehicle headlamp, but the vehicle lighting fixtures to which the present invention can be applied are not limited to the front vehicle lighting fixtures described above, and the present invention can also be applied to rear vehicle lighting fixtures, such as rear combination lamps.

[0112] Furthermore, in addition to the LED described above, light emitting elements such as laser diodes (LDs) can be used for the light source 10. Light sources such as halogen lamps and HID lamps can also be used. The color of the light emitted by the light source 10 can be changed appropriately depending on the application of the light source unit, such as red light, white light, or orange light. A configuration including multiple light source units is also possible.

[0113] In addition to the design role described above, the extension 6 can also be modified in shape and inclination as appropriate to control the airflow F circulating along the inner surface of the outer lens 3.

[0114] Furthermore, the openings 6b and 6c of the extension 6 are not limited to being provided at both ends of the extension 6 as described above, but may be provided at any position on the extension 6. Furthermore, the openings 6b and 6c of the extension 6 may be configured to have a plurality of small slits or holes. In this case, it is possible to make the openings 6b and 6c less noticeable from a design perspective. [Explanation of symbols]

[0115] 1A to 1H... Vehicle lamp 2... Housing 3... Outer lens 4... Lamp body 5... Light source unit 6... Extension 6a, 6b, 6c... Opening 7... Heat generating part 8... Fan 9... Duct 10... Light source 11... Projection lens 12... Circuit board 13... Heat sink 14... Peripheral wall 15... Reflector 16... Frame 17... Bracket F, F1, F2... Air flow K1... Space on outer lens side K2... Space on housing side

Claims

1. a lamp body including a housing with an opening at the front and an outer lens covering the opening of the housing; a light source unit disposed inside the lamp body and emitting light forward; an extension that covers the periphery of the front of the light source unit; a fan that generates an airflow for cooling a heat-generating portion of the light source unit; a duct that guides the airflow blown by the fan to between the light source unit and the extension.

2. 2. The vehicle lamp according to claim 1, wherein the duct has an outlet for blowing out an airflow from between the light source unit and the extension.

3. 3. The vehicle lamp according to claim 2, wherein the air outlets are provided at positions surrounding a front periphery of the light source unit.

4. 2. The vehicle lamp according to claim 1, wherein the duct has a passage opening through which the light emitted from the light source unit passes.

5. the fan is disposed at a position facing the heat generating portion, 2. The vehicle lamp according to claim 1, wherein the duct surrounds the heat generating portion and has a shape that guides the airflow blown by the fan to between the light source unit and the extension.

6. 2. The vehicle lamp according to claim 1, wherein the duct is provided integrally with the light source unit.

7. the extension is arranged to divide the inside of the lamp body into a space on the housing side and a space on the outer lens side, 2. The vehicle lamp according to claim 1, wherein the airflow flowing out from the duct into the space on the outer lens side flows along the inner surface of the outer lens and then flows into the space on the housing side.

8. the extension has an opening that communicates a space on the housing side with a space on the outer lens side, 8. The vehicle lamp according to claim 7, wherein the opening is disposed on at least one end side in the direction in which the extension extends.

9. the light source unit has a light source, 2. The vehicle lamp according to claim 1, wherein the heat generating portion is the light source.

10. 10. The vehicle lamp according to claim 9, wherein the light source unit includes a heat sink for dissipating heat generated by the light source.

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