Vehicle lamp

Abstract

To provide a vehicle lamp capable of ventilating the inside of a lighting body through a simple configuration, and further, controlling a flow air in the lighting body.SOLUTION: A vehicle lamp 1 has a lighting unit 5 disposed inside a lighting body 4 constituted by a housing 2 having an opening in a front surface of the housing and an outer lens 3 configured to cover the opening of the housing 2, a plurality of ventilation ports 11, 12 is provided in the housing 2, and at least one of the plurality of ventilation ports 11, 12 has a diameter that changes between a front surface side and a back surface side of the housing 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to vehicle lamps.

Background Art

[0002] Conventionally, there is 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 at the front and an outer lens (cover lens) that covers the opening of the housing.

[0003] Such a vehicle lamp has a structure in which members such as a light source lamp (light source), an inner lens (light guide), a reflector, an extension, and a bracket that constitute the lamp unit are arranged inside the lamp body, and these members are attached inside the lamp body.

[0004] By the way, in a vehicle lamp, for example, due to temperature changes associated with the lighting / extinguishing of the lamp unit, temperature changes caused by the external environment in which the lamp unit is mounted, such as sunlight irradiation or engine heat generation, the air inside the lamp body expands / contracts, so ventilation (intake / exhaust) is performed through a ventilation port (breathing hole) provided in the lamp body (see, for example, Patent Document 1 below).

[0005] On the other hand, in a vehicle lamp, when the outside air temperature drops below the temperature inside the lamp body, moisture (water) inside the lamp body may condense on the inner surface of the outer lens, causing fogging 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, leading to a decrease in the lamp function (especially illuminance).

[0006] Patent Document 1 below discloses a fog prevention structure for a vehicle lamp that prevents fogging of the lens surface of the lamp by passing air through the lamp. The structure includes an introduction path connected to a draft passage for discharging air in the vehicle interior to the outside of the vehicle body, and a discharge path that branches from the introduction path and directly discharges the air in the vehicle interior to the outside of the vehicle body, both of which are disposed inside the lamp. The tip of the introduction path opens into the lamp chamber provided with a valve. The discharge path communicates with the lamp chamber in the middle and its tip opens to the outside of the vehicle body. A fog prevention structure for a vehicle lamp is disclosed, characterized in that it has such a configuration.

[0007] According to the invention described in Patent Document 1 below, air in the vehicle interior is guided through the draft passage to the introduction path. A part of the air is discharged to the outside of the vehicle body through the discharge path, while most of the air flows into the lamp chamber from the tip of the introduction path. The air that has flowed into the lamp chamber then flows into the discharge path through the connection part between the discharge path and the lamp chamber, and is further discharged from the discharge path to the outside of the vehicle body. As a result, sufficient air flows through the lamp chamber, making it possible to prevent fogging of the inner surface of the lens.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, in the invention described in Patent Document 1 above, ducts are required to form an introduction path for introducing air in the vehicle interior into the lamp chamber and a discharge path for discharging air in the lamp chamber to the outside of the vehicle body. The ducts are separate parts from the vehicle lamp, and their structures become complicated. Also, the cost increases due to the increase in the number of parts.

[0010] The present invention has been proposed in view of such conventional circumstances, and an object thereof is to provide a vehicle lamp that enables ventilation inside the lamp body with a simple configuration and that can control the air flow inside the lamp body.

Means for Solving the Problems

[0011] In order to achieve the above object, the present invention provides the following means. 〔1〕 A vehicle lamp in which a lamp unit is disposed inside a lamp body constituted by a housing having an open front surface and an outer lens covering the opening of the housing, wherein a plurality of ventilation openings are provided in the housing, and at least one of the plurality of ventilation openings has a different diameter between the front side and the back side of the housing. A vehicle lamp characterized by this. 〔2〕 The vehicle lamp according to 〔1〕 above, wherein the plurality of ventilation openings include a first ventilation opening having a smaller diameter on the back side than on the front side of the housing, and a second ventilation opening having a larger diameter on the back side than on the front side of the housing. 〔3〕 The first ventilation opening and the second ventilation opening have a cylindrical duct on at least one side of the back side and the front side of the housing, and the duct has a hole shape in which the diameter continuously or stepwise varies between the front-side opening end and the back-side opening end. The vehicle lamp according to 〔2〕 above, characterized by this.

Effects of the Invention

[0012] As described above, according to the present invention, there is provided a vehicle lamp that enables ventilation inside the lamp body with a simple configuration and that can control the air flow inside the lamp body.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out 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, for the purpose of making each component easy to see, the scale of the dimensions may be made different depending on the component, and the dimensional ratios of each component are not necessarily the same as the actual ones.

[0015] As an embodiment of the present invention, for example, the vehicle lamp 1 shown in FIGS. 1 to 5 will be described. Note that FIG. 1 is a cross-sectional view showing the configuration of the vehicle lamp 1. FIG. 2 is a rear view of the lamp body 4 that constitutes the vehicle lamp 1. FIG. 3 is a cross-sectional view of the lamp body 4 taken along line segment A-A shown in FIG. 2. FIG. 4 is a cross-sectional view showing a modified example of the first ventilation opening 11 and the second ventilation opening 12. FIG. 5 is a rear view of the lamp body 4 in which the arrangements of the first ventilation opening 11 and the second ventilation opening 12 are changed.

[0016] Also, in the drawings shown below, an XYZ orthogonal coordinate system is set, and the X-axis direction is the front-rear direction (length direction) of the vehicle lamp 1, the Y-axis direction is the left-right direction (width direction) of the vehicle lamp 1, and the Z-axis direction is the up-down direction (height direction) of the vehicle lamp 1, and each is shown accordingly.

[0017] The vehicle lamp 1 of the present embodiment is, for example, an application of the present invention to a vehicle headlamp (headlamp) mounted on both corner portions on the front end side of a vehicle (not shown).

[0018] Specifically, as shown in FIG. 1, this vehicle lamp 1 has a structure in which a lamp unit 5 is disposed in a space K inside a lamp body 4 composed of a housing 2 with an open front surface and a transparent outer lens 3 that covers the opening of the housing 2.

[0019] 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 forward of the vehicle.

[0020] Also, inside the lamp body 4, an extension 8 that covers the periphery on the front side of the reflector 7 (lamp unit 5) is disposed. Further, inside the lamp body 4, brackets (not shown) for attaching the above-described members to the inside of the lamp body 4 are disposed. Note that the shape of the lamp body 4 can be appropriately changed according to the design of this vehicle lamp 1 and the like.

[0021] The lamp unit 5 is not necessarily limited to the configuration in which the light reflected by the above-described reflector 7 is irradiated forward of the vehicle. For example, the light emitted from the light source 6 may be irradiated forward of the vehicle using a light guide (not shown) such as an inner lens.

[0022] For 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-described light source lamps, for example, a light-emitting element such as a light-emitting diode (LED) or a laser diode (LD) can be used. Further, the number of light-emitting elements is not limited to one, and a plurality may be used.

[0023] By the way, in the vehicle lamp 1 of the present embodiment, as shown in FIGS. 2 and 3, 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 (intake / exhaust) is performed through a plurality (two in the present embodiment) of ventilation openings 11 and 12 provided on the back side of the housing 2 (lamp body 4).

[0024] 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.

[0025] Specifically, the vehicle lamp 1 of the present embodiment has a first ventilation opening 11 (a1 < a2) in which the diameter a2 on the back side 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 is larger than the diameter b1 on the front side of the housing 2.

[0026] Also, 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 above the second ventilation opening 12.

[0027] The first ventilation opening 11 and the second ventilation opening 12 have ducts 21 and 22 that project cylindrically from at least one side of the back side and the front side of the housing 2. In the present embodiment, the first ventilation opening 11 has a first duct 21 that projects cylindrically from the back side of the housing 2. The second ventilation opening 12 has a second duct 22 that projects cylindrically from the back side of the housing 2. The first and second ventilation openings 11 and 12 are constituted by ventilation holes (breathing holes) that penetrate these first and second ducts 21 and 22.

[0028] The first duct 21 has a linear tapered hole shape in which the diameter continuously decreases from the opening end 21a on the front side toward the opening end 21b on the back side. The second duct 22 has a linear tapered hole shape in which the diameter continuously increases from the opening end 22a on the front side toward the opening end 22b on the back side.

[0029] Filters 31 and caps 32 that cover the first ventilation opening 11 and the second ventilation opening 12 are provided on the back sides of the first duct 21 and the second duct 22.

[0030] The filter 31 is composed of a disc-shaped member having air permeability, such as non-woven fabric, paper, sponge, etc. The filter 31 is disposed in a state of being sandwiched between the open ends 21b, 22b on the back side of the first and second ducts 21, 22 and the cap 32.

[0031] The cap 32 is fitted to the first and second ducts 21, 22 so as to cover the back sides of the first and second ducts 21, 22. A gap communicating with the first and second ventilation openings 11, 12 is provided inside the cap 32.

[0032] In the vehicle lamp 1 of the present embodiment having the above-described configuration, ventilation inside the lamp body 4 is performed through the first ventilation opening 11 and the second ventilation opening 12 described above, thereby preventing condensation (fogging) from occurring on the inner surface of the outer lens 3.

[0033] 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 opening 11 side from the opening end 21a on the front side of the first duct 21 toward the opening end 21b on the back side, and the exhaust inside the lamp body 4 is performed.

[0034] On the other hand, on the second ventilation opening 12 side, an air flow F2 is generated from the opening end 22b on the back side of the second duct 22 toward the opening end 22a on the front side, and the intake inside the lamp body 4 is performed. Also, inside the lamp body 4, an air flow F3 is generated from the lower second ventilation opening 12 toward the upper first ventilation opening 11.

[0035] Thereby, in the vehicle lamp 1 of the present embodiment, while controlling the flowing directions of the air flows F1, F2, F3 generated by the pressure difference inside and outside the lamp body 4, the circulation (convection) of the air inside the lamp body 4 is performed. Also, by performing the circulation (convection) of the air along the inner surface of the outer lens 3, it is possible to prevent fogging from occurring on the inner surface of the outer lens 3.

[0036] In addition, the pressure difference between the inside and outside of the lamp body 4 is not limited to the expansion / contraction of the air inside the lamp body 4 accompanying the temperature change inside the lamp body 4 described above, but also occurs due to the air flow (such as running wind) flowing outside the lamp body 4 when the vehicle is running.

[0037] Therefore, in the vehicle lamp 1 of the present embodiment, not only the temperature change inside the lamp body 4, but also the pressure difference between the inside and outside of the lamp body 4 generated when the vehicle is running causes the above-described air circulation (convection) inside the lamp body 4, so it is possible to prevent fogging from occurring on the inner surface of the outer lens 3.

[0038] Furthermore, 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, so it is possible to enhance the anti-fogging effect on the inner surface of the outer lens 3.

[0039] Also, in the vehicle lamp 1 of the present embodiment, since the air heated inside the lamp body 4 described above becomes the upward air flow F3, a strong air flow F3 is generated from the lower second ventilation port 12 toward the upper first ventilation port 11, and the flow velocity of this air flow F3 increases. Thereby, the heat dissipation effect inside the lamp body 4 can be enhanced, and the temperature inside the lamp body 4 can be efficiently lowered.

[0040] Note that the present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0041] Specifically, the above-described first and second ventilation ports 11 and 12 are not limited to the configurations of the above-described first and second ducts 21 and 22, and may be configured as shown in FIGS. 4(A) to 4(D), for example.

[0042] Among these, the first and second ventilation ports 11 and 12 shown in FIG. 4(A) have a configuration having first and second ducts 21A and 22A in a curved taper shape with different diameters in a curved (continuous) manner between the front-side opening ends 21a and 22a and the back-side opening ends 21b and 22b.

[0043] On the other hand, the first and second ventilation openings 11 and 12 shown in FIG. 4(B) are configured to have first and second ducts 21B and 22B with gradually different diameters between the front-side opening ends 21a and 22a and the back-side opening ends 21b and 22b.

[0044] On the other hand, the first and second ventilation openings 11 and 12 shown in FIG. 4(C) are configured to have first and second ducts 21C and 22C protruding cylindrically from the front side of the housing 2.

[0045] On the other hand, the first and second ventilation openings 11 and 12 shown in FIG. 4(D) are configured such that the first and second ducts 21 and 22 are omitted, and the diameters are different between the front-side opening ends 21a and 22a of the housing 2 and the back-side opening ends 21b and 22b of the housing 2.

[0046] Also, for the first and second ventilation openings 11 and 12, as shown in FIGS. 5(A) and 5(B) for example, it is possible to appropriately change and optimize their arrangements and numbers according to the space K in the lamp body 4.

[0047] Among these, the lamp body 4 shown in FIG. 5(A) is configured to have one first ventilation opening 11 on the upper side and two second ventilation openings on the lower side. On the other hand, the lamp body 4 shown in FIG. 5(B) is configured to have two first ventilation openings 11 on the upper side and two second ventilation openings on the lower side.

[0048] Note that in the present invention, it is sufficient that 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, and the configuration may include a ventilation opening having the same diameter between the front side and the back side of the housing 2.

[0049] Also, the front-side diameter a1 and the back-side diameter a2 of the first ventilation opening 11, the front-side diameter b1 and the back-side diameter b2 of the second ventilation opening 12, and the lengths of the first and second ducts 21 and 22 are not particularly limited and can be appropriately changed.

[0050] On the one hand, when the diameter a2 on the back side of the first ventilation opening 11 is made to match 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.

[0051] Moreover, the above-described first and second ventilation openings 11 and 12 are not limited to the configuration arranged in the vertical direction as described above, and may be arranged in the horizontal direction. By configuring the first ventilation opening 11 side as an exhaust port and the second ventilation opening 12 side as an intake port, ventilation inside the lamp body 4 can be performed through these first ventilation opening 11 and second ventilation opening 12.

[0052] In the above embodiment, the case where the present invention is applied to a vehicle headlamp (headlamp) is illustrated. However, the vehicle lamps to which the present invention is applied are not limited to the above-described front-side vehicle lamps, and the present invention can also be applied to rear-side vehicle lamps such as rear combination lamps.

Example

[0053] Hereinafter, the effects of the present invention will be made clearer by examples. The present invention is not limited to the following examples, and can be appropriately modified and implemented without changing the gist thereof.

[0054] (First Embodiment) In the first embodiment, as shown in FIGS. 6(A) to 6(C), two ventilation openings 101 and 102 are provided on the upper side and the lower side of the back surface of a box 100 imitating a lamp body, and the flow of the air current F generated in the box 100 due to the difference in the hole shapes of these ventilation openings 101 and 102 is obtained by simulation.

[0055] Among these, the box 100 shown in FIG. 6(A) 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.

[0056] On the one hand, in the case of the box 100 shown in FIG. 6(B), 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.

[0057] On the other hand, in the case of the box 100 shown in FIG. 6(C), 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.

[0058] Also, inside the box 100, a partition wall 104 is provided that partitions the space between the upper ventilation opening 101 and the lower ventilation opening 102.

[0059] For the boxes shown in FIGS. 6(A) to (C), while flowing air at a constant wind speed in the direction from the near side to the far side of the paper surface, the direction of the air flow F generated inside the box 100 when a pressure difference is applied between the inside and outside of the box was obtained.

[0060] As a result, inside the box 100 shown in FIG. 6(A), air flows F in the same direction were generated from the upper ventilation opening 101 and the lower ventilation opening 102 toward the outside.

[0061] On the one hand, inside the box 100 shown in FIG. 6(B), 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 were generated.

[0062] On the other hand, inside the box 100 shown in FIG. 6(C), 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 were generated.

[0063] From the above, by making the diameters different in opposite directions between the upper ventilation opening 101 and the lower ventilation opening 102, a difference in pressure loss occurs. Also, due to the pressure loss, a difference occurs in the flow velocity (dynamic pressure) of the air current, and the direction in which the air current flows is determined by the generated dynamic pressure difference. Thus, it was confirmed that the flow of the air current F generated within the box 100 can be controlled.

[0064] (Second Embodiment) In the second embodiment, the flow of the air current F generated within the box 100 when a heat source Q1 with a constant temperature of 100°C was arranged within the box 100 shown in FIGS. 6(A) and 6(B) above was obtained by simulation. Note that the heat source Q1 was arranged at a position orthogonal to the partition wall 104.

[0065] As a result, in the box 100 shown in FIG. 6(A), an air current F flowing outward from the upper ventilation opening 101 was generated, and the maximum value of its flow velocity was 14.38 cm / s. On the other hand, an air current F flowing inward from the lower ventilation opening 102 was generated, and the maximum value of its flow velocity was 13.77 cm / s.

[0066] In contrast, in the box 100 shown in FIG. 6(B), an air current F flowing outward from the upper ventilation opening 101 was generated, and the maximum value of its flow velocity was 17.17 cm / s. On the other hand, an air current F flowing inward from the lower ventilation opening 102 was generated, and the maximum value of its flow velocity was 15.30 cm / s.

[0067] From the above, by making the diameters different in opposite directions between the upper ventilation opening 101 and the lower ventilation opening 102, it was confirmed that when the temperature within the box 100 rises, the flow velocity of the air current F generated within the box 100 improves.

[0068] (Third Embodiment) In the third embodiment, the temperature change from room temperature within the box 100 when a heat source Q2 with a constant output of 2W was arranged within the box 100 shown in FIGS. 6(A) and 6(B) above was obtained by simulation. Note that the heat source Q2 was arranged at a position parallel to the partition wall 104.

[0069] As a result, the temperature inside the box 100 shown in Fig. 6(A) rose to 57.27°C. In contrast, the temperature inside the box 100 shown in Fig. 6(B) rose to 55.10°C.

[0070] From the above, it was confirmed that by making the diameters different in opposite directions between the upper ventilation opening 101 and the lower ventilation opening 102, when the temperature inside the box 100 rises, the circulation (convection) of the air inside the box 100 is promoted.

[0071] In particular, in the box 100 shown in Fig. 6(B), 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. In the case of this configuration, the air warmed inside the box 100 becomes an upward airflow, so a strong airflow F is generated from the lower ventilation opening 102 toward the upper ventilation opening 101, and the flow velocity of this airflow F increases. As a result, it was confirmed that the heat dissipation effect inside the box 100 is enhanced and the temperature inside the box 100 decreases efficiently.

Description of Reference Numerals

[0072] 1... Vehicle lamp 2... Housing 3... Outer lens 4... Lamp body 5... Lamp unit 6... Light source 7... Reflector 8... Extension 11... First ventilation opening 12... Second ventilation opening 21, 21A to 21D... First duct 22, 22A to 22D... Second duct 31... Filter 32... Cap F1, F2, F3... Airflow

Claims

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

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

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

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