Vehicle lamp

Abstract

In a vehicle lamp, a lamp unit is disposed on the inside of a lamp body, the lamp body is composed of a housing having an opening on the front surface and an outer lens covering the opening of the housing, the housing is provided with a plurality of ventilation ports, and at least one of the plurality of ventilation ports has a different aperture between the front surface side and the back surface side of the housing.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2024-005784 filed on January 18, 2024, the content of which is incorporated herein by reference. Technical Field

[0002] The present invention relates to a vehicle lamp. Background Art

[0003] Conventionally, there has been a vehicle lamp in which a lamp unit that irradiates light forward is disposed inside a lamp body composed of a housing having an opening on the front surface and an outer lens (cover lens) that covers the opening of the housing.

[0004] Such a vehicle lamp has a structure in which components such as a light source lamp (light source), an inner lens (light guide), a reflector, an extension part, and a bracket that constitute the lamp unit are disposed inside the lamp body, and these components are mounted inside the lamp body.

[0005] However, in a vehicle lamp, due to temperature changes such as those caused by the lighting / extinguishing of the lamp unit, sunlight irradiation, engine heat generation, etc., and temperature changes in the external environment where the lamp unit is mounted, the air inside the lamp body expands / contracts, and thus ventilation (inhalation / exhaust) is performed through a ventilation port (breathing hole) provided in the lamp body (for example, refer to Japanese Unexamined Patent Application Publication No. 2007-335292).

[0006] On the other hand, in a vehicle lamp, when the external air temperature is lower than the temperature inside the lamp body, moisture (water) inside the lamp body sometimes condenses on the inner surface of the outer lens, and fog is generated on the inner surface of the outer lens. When condensation (fogging) occurs on the inner surface of the outer lens, not only does the appearance deteriorate, but also the transmittance of the light irradiated forward from the lamp unit decreases, resulting in a reduction in the lamp function (especially illuminance).

[0007] Japanese Unexamined Patent Application Publication No. 2007-335292 discloses an anti-fog structure for a vehicle lamp that prevents fogging of the lens surface of the lamp by allowing air to pass through the lamp. The anti-fog structure for the vehicle lamp is characterized in that an introduction path and a discharge path are provided in the lamp. The introduction path is connected to a ventilation passage for discharging air in the vehicle interior to the outside of the vehicle body. The discharge path branches from the introduction path and directly discharges the air in the vehicle interior to the outside of the vehicle body. On the other hand, the front end of the introduction path opens into a lamp chamber where a bulb is provided, and the middle of the discharge path communicates with the lamp chamber, and the front end opens to the outside of the vehicle body.

[0008] According to the invention described in Japanese Patent Application Laid-Open No. 2007-335292, the air in the vehicle interior is introduced into the lamp chamber through a ventilation passage and an introduction path. A part of the air is discharged to the outside of the vehicle body through a discharge path, but most of the air flows into the lamp chamber from the front end of the introduction path. Then, the air flowing into the lamp chamber flows into the discharge path through the connection part between the discharge path and the lamp chamber, and is further discharged to the outside of the vehicle body through the discharge path. Thus, the air flows sufficiently in the lamp chamber, and fogging on the inner surface of the lens can be prevented. Summary of the Invention

[0009] However, in the invention described in Japanese Patent Application Laid-Open No. 2007-335292, a duct is required to form an introduction path for introducing the air in the vehicle interior into the lamp chamber and a discharge path for discharging the air in the lamp chamber to the outside of the vehicle body. The duct becomes a component different from the vehicle lamp, and its structure is also complicated. In addition, due to the increase in the number of components, the cost also increases.

[0010] An aspect of the present invention is to provide a vehicle lamp that can ventilate the inside of the lamp body with a simple structure and can control the flow of air inside the lamp body.

[0011] The aspect of the present invention provides the following configuration.

[0012] 〔1〕A vehicle lamp according to an aspect of the present invention

[0013] A lamp unit is disposed inside the lamp body, and the lamp body is composed of a housing having an opening on the front surface and an outer lens covering the opening of the housing. It is characterized in that

[0014] A plurality of ventilation openings are provided in the housing,

[0015] The diameter of at least one of the plurality of ventilation openings is different between the front side and the back side of the housing.

[0016] 〔2〕In the vehicle lamp according to the aspect 〔1〕 above, it is characterized in that

[0017] The plurality of ventilation openings include: a first ventilation opening having a smaller diameter on the back side of the housing than on the front side of the housing; and a second ventilation opening having a larger diameter on the back side of the housing than on the front side of the housing.

[0018] 〔3〕In the vehicle lamp according to the aspect 〔2〕 above, it is characterized in that

[0019] The first ventilation opening and the second ventilation opening each have a cylindrical duct on at least one of the back side and the front side of the housing,

[0020] The pipe has a hole shape in which the diameter continuously or stepwise varies between the open end on the front side and the open end on the back side.

[0021] According to an aspect of the present invention, there is provided a vehicle lamp that can ventilate the inside of the lamp body with a simple structure and can control the flow of air inside the lamp body. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view showing the structure of a vehicle lamp according to an embodiment of the present invention.

[0023] Figure 2 is a component of Figure 1 The rear view of the lamp body that forms the vehicle lamp shown.

[0024] Figure 3 is based on Figure 2 The cross-sectional view of the lamp body along the line III-III shown in.

[0025] Figure 4 It is a cross-sectional view showing a modified example of the first ventilation port and the second ventilation port.

[0026] Figure 5 The rear view of the lamp body in which the arrangement of the first ventilation port and the second ventilation port is changed.

[0027] Figure 6 It is a cross-sectional view showing a box body that imitates the lamp body in the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0029] In addition, in the drawings used in the following description, in order to easily observe each component, the scale of the dimensions may be different depending on the component, and the dimensional ratios of the components are not necessarily the same as the actual ones.

[0030] As an embodiment of the present invention, for example, Figures 1 to 5 the vehicle lamp 1 shown will be described.

[0031] In addition, Figure 1 It is a cross-sectional view showing the structure of the vehicle lamp 1. Figure 2 The rear view of the lamp body 4 that forms the vehicle lamp 1. Figure 3 is based on Figure 2 The cross-sectional view of the lamp body 4 along the line III-III shown in. Figure 4 It is a cross-sectional view showing a modified example of the first ventilation port 11 and the second ventilation port 12. Figure 5 The rear view of the lamp body 4 in which the arrangement of the first ventilation port 11 and the second ventilation port 12 is changed.

[0032] In addition, in the accompanying drawings shown below, an XYZ orthogonal coordinate system is set, the X-axis direction represents the front-rear direction (length direction) of the vehicle lamp 1, the Y-axis direction represents the left-right direction (width direction) of the vehicle lamp 1, and the Z-axis direction represents the up-down direction (height direction) of the vehicle lamp 1.

[0033] The vehicle lamp 1 of the present embodiment applies the present invention to, for example, vehicle headlamps (headlights) mounted on both corner portions on the front end side of a vehicle (not shown).

[0034] Specifically, as Figure 1 shown, the vehicle lamp 1 has the following structure: a lamp unit 5 is disposed in a space K inside a lamp body 4 composed of a housing 2 having an opening on the front surface and a transparent outer lens 3 covering the opening of the housing 2.

[0035] The lamp unit 5 includes, for example, a light source 6 that emits white light (hereinafter simply referred to as light) and a reflector 7 that reflects the light emitted from the light source 6, and is configured to irradiate the light reflected by the reflector 7 toward the front of the vehicle.

[0036] In addition, an extension portion 8 that covers the periphery of the front side of the reflector 7 (lamp unit 5) is disposed inside the lamp body 4. Moreover, a bracket (not shown) for mounting the above components inside the lamp body 4 is disposed inside the lamp body 4. In addition, the shape of the lamp body 4 can be appropriately changed in accordance with the design of the vehicle lamp 1 and the like.

[0037] Regarding the lamp unit 5, it is not necessarily limited to the structure that irradiates the light reflected by the reflector 7 toward the front of the vehicle. For example, it may also be a structure that irradiates the light emitted from the light source 6 toward the front of the vehicle using a light guide body such as an inner lens (not shown).

[0038] Regarding the light source 6, for example, a light source lamp such as a halogen lamp or an HID lamp can be used. In addition to the above light source lamp, light emitting elements such as light emitting diodes (LEDs) and laser diodes (LDs) can also be used. And the number of light emitting elements is not limited to one, and may also be a plurality.

[0039] However, in the vehicle lamp 1 of the present embodiment, as Figure 2 and Figure 3 shown, due to the temperature change accompanying the lighting / extinguishing of the lamp unit 5, the air inside the lamp body 4 expands / contracts, so ventilation (inhalation / exhaust) is performed through a plurality of (two in the present embodiment) ventilation openings 11, 12 provided on the back side of the housing 2 (lamp body 4).

[0040] In the vehicle lamp 1 of the present embodiment, at least one of the plurality of ventilation openings 11 and 12 has a different diameter between the front side and the back side of the housing 2.

[0041] Specifically, the vehicle lamp 1 of the present embodiment includes: a first ventilation opening 11 (a1 < a2) in which the diameter a2 on the back side of the housing 2 is smaller than the diameter a1 on the front side of the housing 2; and a second ventilation opening 12 (b1 > b2) in which the diameter b2 on the back side of the housing 2 is larger than the diameter b1 on the front side of the housing 2.

[0042] In addition, the first ventilation opening 11 is disposed on the upper side of the housing 2, and the second ventilation opening 12 is disposed on the lower side of the housing 2. That is, the first ventilation opening 11 is located at a position above the second ventilation opening 12.

[0043] The first ventilation opening 11 and the second ventilation opening 12 have pipes 21 and 22 that project in a cylindrical shape from at least one of the back side and the front side of the housing 2. In the present embodiment, the first ventilation opening 11 has a first pipe 21 that projects in a cylindrical shape from the back side of the housing 2. The second ventilation opening 12 has a second pipe 22 that projects in a cylindrical shape from the back side of the housing 2. The first ventilation opening 11 and the second ventilation opening 12 are constituted by ventilation holes (breathing holes) that penetrate the first pipe 21 and the second pipe 22.

[0044] The first pipe 21 has a straight conical hole shape in which the diameter linearly (continuously) decreases from the opening end 21a on the front side toward the opening end 21b on the back side. The second pipe 22 has a straight conical hole shape in which the diameter linearly (continuously) increases from the opening end 22a on the front side toward the opening end 22b on the back side.

[0045] Filters 31 and covers 32 that cover the first ventilation opening 11 and the second ventilation opening 12 are provided on the back side of the first pipe 21 and the second pipe 22.

[0046] The filter 31 is formed of a breathable disk-shaped member such as non-woven fabric, paper, or sponge, for example. The filter 31 is disposed in a state of being sandwiched between the opening ends 21b and 22b on the back side of the first pipe 21 and the second pipe 22 and the cover 32.

[0047] The cover 32 is fitted and installed in the first pipe 21 and the second pipe 22 so as to cover the back side of the first pipe 21 and the second pipe 22. A gap communicating with the first ventilation opening 11 and the second ventilation opening 12 is provided inside the cover 32.

[0048] In the vehicle lamp 1 of the present embodiment having the above structure, ventilation inside the lamp body 4 is performed through the above-described first ventilation opening 11 and second ventilation opening 12, thereby preventing dew condensation (fogging) from occurring on the inner surface of the outer lens 3.

[0049] Specifically, in the vehicle lamp 1 of the present embodiment, due to the pressure difference (dynamic pressure or static pressure) generated inside and outside the lamp body 4, an air flow F1 is generated on the first ventilation port 11 side from the front opening end 21a of the first duct 21 toward the back opening end 21b, and the air inside the lamp body 4 is exhausted.

[0050] On the other hand, on the second ventilation port 12 side, an air flow F2 is generated from the back opening end 22b of the second duct 22 toward the front opening end 22a, and the air inside the lamp body 4 is sucked in. In addition, inside the lamp body 4, an air flow F3 is generated from the lower second ventilation port 12 toward the upper first ventilation port 11.

[0051] Thus, in the vehicle lamp 1 of the present embodiment, while controlling the flow directions of the air flows F1, F2, and F3 generated due to the pressure difference inside and outside the lamp body 4, the air inside the lamp body 4 is circulated (convected). In addition, by circulating (convecting) the air along the inner surface of the outer lens 3, fogging on the inner surface of the outer lens 3 can be prevented.

[0052] In addition, the pressure difference inside and outside the lamp body 4 is not limited to the expansion / contraction of the air inside the lamp body 4 accompanying the above-mentioned temperature change inside the lamp body 4, and this pressure difference is also generated due to the air flow (traveling wind, etc.) flowing outside the lamp body 4 during vehicle travel.

[0053] Therefore, in the vehicle lamp 1 of the present embodiment, not limited to the temperature change inside the lamp body 4, due to the pressure difference inside and outside the lamp body 4 generated during vehicle travel, the above-mentioned air circulation (convection) inside the lamp body 4 also occurs, and thus fogging on the inner surface of the outer lens 3 can be prevented.

[0054] Moreover, in the vehicle lamp 1 of the present embodiment, when the air inside the lamp body 4 expands, the air circulation (convection) inside the lamp body 4 is promoted, and thus the anti-fogging effect on the inner surface of the outer lens 3 can be improved.

[0055] In addition, in the vehicle lamp 1 of the present embodiment, the heated air inside the lamp body 4 becomes the rising air flow F3, so a strong air flow F3 is generated from the lower second ventilation port 12 toward the upper first ventilation port 11, and the flow rate of this air flow F3 increases. Thereby, the heat dissipation effect inside the lamp body 4 can be improved, and the temperature inside the lamp body 4 can be efficiently reduced.

[0056] Furthermore, the present invention is not necessarily limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.

[0057] Specifically, the above-mentioned first ventilation port 11 and second ventilation port 12 are not limited to the structures of the above-mentioned first duct 21 and second duct 22, and for example, they can also beFigure 4 The structure shown in parts (A) to (D).

[0058] Among them, Figure 4 The first ventilation openings 11 and the second ventilation openings 12 shown in part (A) have a structure in which the first ducts 21A and the second ducts 22A are curved cones (continuously) with different diameters between the opening ends 21a, 22a on the front side and the opening ends 21b, 22b on the back side.

[0059] On the other hand, Figure 4 The first ventilation openings 11 and the second ventilation openings 12 shown in part (B) have a structure in which the first ducts 21B and the second ducts 22B have different diameters stepwise between the opening ends 21a, 22a on the front side and the opening ends 21b, 22b on the back side.

[0060] On the other hand, Figure 4 The first ventilation openings 11 and the second ventilation openings 12 shown in part (C) have a first duct 21C and a second duct 22C that project cylindrically from the front side of the housing 2.

[0061] On the other hand, Figure 4 The first ventilation openings 11 and the second ventilation openings 12 shown in part (D) omit the first ducts 21 and the second ducts 22, and have a structure in which the diameters are different between the opening ends 21a, 22a on the front side of the housing 2 and the opening ends 21b, 22b on the back side of the housing 2.

[0062] In addition, regarding the above-mentioned first ventilation openings 11 and second ventilation openings 12, for example, as shown in part (A) of Figure 5 and part (B) of Figure 5 , it is possible to appropriately change their arrangements and quantities in accordance with the space K in the lamp body 4 and optimize them.

[0063] Among them, Figure 5 The lamp body 4 shown in part (A) has a structure with one first ventilation opening 11 on the upper side and two second ventilation openings on the lower side. On the other hand, Figure 5 The lamp body 4 shown in part (B) has a structure with two first ventilation openings 11 on the upper side and two second ventilation openings on the lower side.

[0064] It should be noted that in the present invention, as long as at least one of the plurality of ventilation openings has different diameters between the front side and the back side of the housing 2, it can be configured to include ventilation openings with the same diameter between the front side and the back side of the housing 2.

[0065] In addition, the diameter a1 on the front side and the diameter a2 on the back side of the first ventilation opening 11, the diameter b1 on the front side and the diameter b2 on the back side of the second ventilation opening 12, and the lengths of the first duct 21 and the second duct 22 are not particularly limited and can be appropriately changed.

[0066] On the other hand, when the diameter a2 on the back side of the first ventilation opening 11 is made to coincide with the diameter b2 on the back side of the second ventilation opening 12 (a2 = b2), the inflow of air into the lamp body 4 can be suppressed to a low level, and the outflow of air from the lamp body 4 can be promoted.

[0067] In addition, the above-mentioned first ventilation opening 11 and second ventilation opening 12 are not limited to the structure arranged in the vertical direction as described above, and may also be a structure arranged in the horizontal direction. The side of the first ventilation opening 11 constitutes an exhaust port, and the side of the second ventilation opening 12 constitutes an intake port, whereby ventilation inside the lamp body 4 can be performed via the above-mentioned first ventilation opening 11 and second ventilation opening 12.

[0068] In addition, in the above embodiment, the case where the present invention is applied to a vehicle headlamp (headlight) is illustrated. However, regarding the vehicle lamp to which the present invention is applied, it is not limited to the above-mentioned front vehicle lamp, and for example, the present invention can also be applied to a rear combination lamp or other rear vehicle lamps.

[0069] [Examples]

[0070] Hereinafter, the effects of the present invention will be further clarified by examples. In addition, the present invention is not limited to the following examples and can be appropriately modified and implemented within the scope of not changing its gist.

[0071] (First Embodiment)

[0072] In the first embodiment, as Figure 6 shown in parts (A) to (C) of [], two ventilation openings 101 and 102 are provided on the upper side and the lower side of the back surface of the box body 100 imitating the lamp body, and the flow of the air flow F generated in the box body 100 due to the different hole shapes of these ventilation openings 101 and 102 is obtained by simulation.

[0073] Among them, Figure 6 the box body 100 shown in part (A) of [] is a case where the diameter of the upper ventilation opening 101 is constant and the diameter of the lower ventilation opening 102 is constant.

[0074] On the other hand, Figure 6 the box body 100 shown in part (B) of [] is a case where the diameter of the upper ventilation opening 101 becomes smaller toward the back side and the diameter of the lower ventilation opening 102 becomes larger toward the back side.

[0075] On the other hand, Figure 6The casing 100 shown in part (C) is such that the diameter of the upper ventilation opening 101 becomes larger toward the back side, and the diameter of the lower ventilation opening 102 becomes smaller toward the back side.

[0076] In addition, a partition wall 104 that separates between the upper ventilation opening 101 and the lower ventilation opening 102 is provided inside the casing 100.

[0077] Regarding these Figure 6 For the casings shown in parts (A) to (C) of these, while making the wind flow in the direction from the front side of the paper surface toward the inside at a constant wind speed, the direction of the air flow F generated inside the casing 100 when a pressure difference is applied between the inside and outside of the casing is obtained.

[0078] As a result, inside the casing 100 shown in part (A) of Figure 6 these, air flows F in the same direction are generated from the upper ventilation opening 101 and the lower ventilation opening 102 toward the outside.

[0079] On the other hand, inside the casing 100 shown in part (B) of Figure 6 these, an air flow F from the lower ventilation opening 102 toward the inside, an air flow F from the upper ventilation opening 101 toward the outside, and an air flow F from the lower ventilation opening 102 toward the upper ventilation opening 101 are generated.

[0080] On the other hand, inside the casing 100 shown in part (C) of Figure 6 these, an air flow F from the upper ventilation opening 101 toward the inside, an air flow F from the lower ventilation opening 102 toward the outside, and an air flow F from the upper ventilation opening 101 toward the lower ventilation opening 102 are generated.

[0081] Based on the above, by making the diameters different in opposite directions between the upper ventilation opening 101 and the lower ventilation opening 102, the pressure loss varies. In addition, due to the pressure loss, the flow velocity (dynamic pressure) of the air flow varies, and the direction of the air flow is determined by the generated dynamic pressure difference. Thus, it was confirmed that the flow of the air flow F generated inside the casing 100 can be controlled.

[0082] (Second Embodiment)

[0083] In the second embodiment, by simulation, the flow of the air flow F generated inside the casing 100 when a heat source Q1 having a constant temperature of 100 °C is disposed inside the casings shown in parts (A) and (B) of the above Figure 6 is obtained. In addition, the heat source Q1 is disposed at a position perpendicular to the partition wall 104.

[0084] As a result, in Figure 6In the case of the airtight container 100 shown in part (A), an air current F directed outward is generated from the upper ventilation opening 101, and the maximum value of its flow velocity is 14.38 cm / s. On the other hand, an air current F directed inward is generated from the lower ventilation opening 102, and the maximum value of its flow velocity is 13.77 cm / s.

[0085] In contrast, Figure 6 In the airtight container 100 shown in part (B), an air current F directed outward is generated from the upper ventilation opening 101, and the maximum value of its flow velocity is 17.17 cm / s. On the other hand, an air current F directed inward is generated from the lower ventilation opening 102, and the maximum value of its flow velocity is 15.30 cm / s.

[0086] Based on the above, it was confirmed that by making the diameters of the upper ventilation opening 101 and the lower ventilation opening 102 different in the reverse direction from each other, when the temperature in the airtight container 100 rises, the flow velocity of the air current F generated in the airtight container 100 increases.

[0087] (Third Embodiment)

[0088] In the third embodiment, by simulation, the temperature change from room temperature in the airtight container 100 was obtained when a heat source Q2 with a constant output of 2 W was arranged in the airtight container 100 shown in parts (A) and (B) above. In addition, the heat source Q2 is arranged at a position parallel to the partition wall 104. Figure 6 As a result,

[0089] the temperature in the airtight container 100 shown in part (A) rose to 57.27°C. In contrast, Figure 6 the temperature in the airtight container 100 shown in part (B) rose to 55.10°C. Figure 6

[0090] Based on the above, it was confirmed that by making the diameters of the upper ventilation opening 101 and the lower ventilation opening 102 different in the reverse direction from each other, when the temperature in the airtight container 100 rises, the circulation (convection) of the air in the airtight container 100 is promoted.

[0091] In particular, Figure 6 in the airtight container 100 shown in part (B), the diameter of the upper ventilation opening 101 is configured to become smaller toward the back side, and the diameter of the lower ventilation opening 102 is configured to become larger toward the back side. In the case of this structure, the air heated inside the airtight container 100 becomes an upward air current, and thus a strong air current F is generated from the lower ventilation opening 102 toward the upper ventilation opening 101, and the flow velocity of this air current F increases. As a result, it was confirmed that the heat dissipation effect inside the airtight container 100 is improved, and the temperature inside the airtight container 100 is efficiently reduced.​

Claims

1. A vehicle lamp, in which a lamp unit is disposed inside a lamp body, and the lamp body is composed of a housing having an opening on a front surface and an outer lens covering the opening of the housing, characterized in that, a plurality of ventilation openings are provided in the housing, at least one of the plurality of ventilation openings has a different diameter between the front side and the back side of the housing.

2. The vehicle lamp according to claim 1, characterized in that, the plurality of ventilation openings include: a first ventilation opening having a smaller diameter on the back side of the housing than on the front side of the housing; and a second ventilation opening having a larger diameter on the back side of the housing than on the front side of the housing.

3. The vehicle lamp according to claim 2, characterized in that, the first ventilation opening and the second ventilation opening each have a cylindrical pipe portion on at least one of the back side and the front side of the housing, and the pipe portion has a hole shape in which the diameter continuously or stepwise varies between the opening end on the front side and the opening end on the back side.

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