JPH0592904U - Anti-fog device for automobile headlamps - Google Patents

Abstract

(57) [Summary] [Object] To provide an anti-fogging device for a headlamp for an automobile, which eliminates dew condensation in the headlamp and effectively prevents fogging. A head lamp including an outer lens 6 having a dummy portion 6a wrapping around to a fender panel, a lamp system to which the outer lens 6 is attached, and a reflector 4 for the lamp system. 6
The forced dew condensation device 12 is installed at a position corresponding to a, and the moisture in the head lamp is condensed and removed by the forced dew condensation device 12 using the air convection in the head lamp. In particular, the forced dew condensation device 12 is a reflector. 4, a dew condensation part 15 provided in close contact with the low temperature side of the thermoelectric element 13, and a water drop receiver 1 installed below the dew condensation part 15.
6 and 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an anti-fogging device for a headlight of a vehicle.

[0002]

[Prior Art]

 In headlamps for passenger cars and the like, it is important to eliminate the fog on the lens surface of the outer lens in order to obtain good light distribution characteristics. FIG. 6 shows a configuration example of a headlamp having an outer lens in which a dummy part of a clearance lamp wraps around to a fender panel. In the figure, the front direction of the vehicle is indicated by an arrow Fr, and the vehicle width direction is indicated by an arrow S. In FIG. 1, 1 is a headlamp body having a bulb 1a, and 2 is a clearance lamp having a bulb 2a. These lamps 1 and 2 have reflectors 3 and 4, respectively, and are housed in a resin-molded housing 5. The surfaces of the reflectors 3 and 4 are formed as reflecting surfaces made of aluminum vapor deposition.

In the outer lens 6, a dummy part 6 a of the clearance lamp 2 is wrapped around to the fender panel 7. The dummy portion 6a does not fulfill the essential function of the headlamp, but is extremely important in terms of the external appearance of the headlamp. By the way, when the headlamp main body 1 or the clearance lamp 2 is turned on, the heat of the bulbs 1a and 2a thereof causes a particularly high temperature around them. On the other hand, the temperature of the dummy portion 6a located at a position distant from the valves 1a and 2a is lower than the temperature around the valves 1a and 2a, and is rather strongly cooled by the outside air.

[0004]

[Problems to be solved by the device]

 In the conventional headlamp described above, the air locally heated by the heat generation of the bulbs 1a and 2a flows to the dummy portion 6a in the low temperature region as described above, as shown by the solid arrow in the figure. Form air convection. The convection air is hot and humid, and is cooled when passing through the dummy portion 6a to cause dew condensation on the inner surface of the dummy portion 6a and the surface of the reflector 4. As a result, water drops adhere to the surfaces of the outer lens 6 and the reflector 4 centering on the dummy portion 6a, and a cloudy portion 8 is generated. The mist 8 does not only affect the dummy portion 6a, but significantly affects the light distribution characteristics of the headlamp. Further, when the headlamp that has been turned on is turned off, the pressure inside the headlamp drops, so that hot and humid air is drawn into the headlamp, especially in rainy weather. Such hot and humid air causes the cloud 8 as described above when the headlamp is turned on again, and this is repeated as the headlamp is turned on and off.

By the way, with respect to the problem of clouding in the headlamp as described above, it is attempted to suppress air convection to the dummy portion 6a by installing a partition plate 9 between the reflectors 3 and 4 as shown in the figure. There is a structure. However, even when such a partition plate 9 is used, the boundary between the partition plate 9 and the reflectors 3 and 4 and the housing 5 and the like is considered in terms of expansion and contraction deformation of the resin component due to heat, component accuracy and appearance. It is practically difficult to close the gap. Therefore, as shown by the dotted line in the figure, air convection is still formed to the dummy portion 6a, and it was not possible to effectively prevent the generation of the cloudy weather 8.

In view of the above problems, the present invention aims to provide an anti-fogging device for a headlamp for an automobile, which is capable of effectively preventing fogging in a headlamp of this type by preventing dew condensation. And

[0007]

[Means for Solving the Problems]

 The device for preventing fogging of a headlamp for an automobile according to the present invention comprises a headlamp including an outer lens having a dummy part wrapping around to a fender panel, a lamp system to which the outer lens is attached, and a reflector for the lamp system. In the above, a forced dew condensation device is installed at a position corresponding to the dummy part of the reflector, and the convection of air in the head lamp is used to dehumidify and remove the moisture in the head lamp. is there.

In particular, the above-mentioned forced dew condensation device is preferably a thermoelectric element mounted on the back surface of the reflector, a dew condensation part provided in close contact with the low temperature part side of the thermoelectric element, and a water drop receiver provided below the dew condensation part. And the above-mentioned dew condensation part is arranged in the air convection inside the headlamp. In addition, it is preferable that the dew condensation portion is composed of a plurality of mesh slits.

[0009]

[Action]

 According to this invention, the air inside the headlamp is dehumidified and heated by dehumidifying and removing the moisture inside the headlamp with the forced dew condensation device, thereby preventing the clouding of the lens surface of the outer lens. can do.

That is, the air is locally heated by the heat generated by the headlamps that are turned on, and the heated air flows to the dummy portion. A forced dew condensation device is installed on the back side of the reflector of the dummy part, and the hot and humid air is cooled and condensed when passing through the dew condensation part of the forced dew condensation device at a low temperature. The water droplets generated by this dew condensation are collected by the water droplet receiver and discharged to the outside of the headlamp. In this way, the air that has passed through the dew condensation section is dehumidified. Further, the dehumidified air passes through the surface side of the reflector, which has a high temperature, so that the dehumidified air is heated and its humidity is further reduced. As described above, since the air inside the headlamp is dehumidified and heated, no clouding occurs on the lens surface of the outer lens. Further, by forming the dew condensation part of the forced dew condensation device with a plurality of reticulated slits, the convection air smoothly flows therethrough, so that the air convection in the headlamp can be effectively used.

[0011]

【Example】

 An embodiment of an anti-fog device for an automobile headlamp according to the present invention will be described below with reference to FIGS. FIG. 1 shows the overall structure of a headlamp, and a headlamp body 1, a clear lamp 2 and a fog lamp 10 constitute a lamp system. The fog lamp 10 has a bulb 10a, and the housing 5 is provided with a breathing port 11 for communicating the inside and the outside of the headlamp. In the outer lens 6, the dummy portion 6a of the clear lamp 2 goes around to the fender panel 7. A forced dew condensation device 12 is installed at the corresponding position of the dummy portion 6a of the reflector 4.

As shown in FIGS. 2 and 3, the forced dew condensation device 12 is provided in close contact with the thermoelectric element 13 mounted on the back surface of the reflector 4 and the low temperature side of the thermoelectric element 13 via the cooling surface 14. The dew condensation part 15 and the water drip pan 16 installed below the dew condensation part 15 are provided.

Still referring to FIG. 4, the thermoelectric element 13 has a high temperature surface 13 a and a low temperature surface 13 b, and the high temperature surface 13 a is bonded to the bonding portion 4 a of the reflector 4. A lead wire 17 is connected to the thermoelectric element 13. In this example, the dew condensation portion 15 is composed of a plurality of mesh slits 15a, and each mesh slit 15a is arranged in a row on the cooling surface 14 made of a steel plate so as to close the gap between the reflector 4 and the housing 5 (see FIG. 3). Has been done. The cooling surface 14 is adapted to be bonded to the low temperature surface 13b of the thermoelectric element 13. The water drop receiver 16 is fixed to the mounting portion 4b of the reflector 4 by a method such as spot welding and has an area capable of covering at least the size of the dew condensation portion 15. Then, it is connected to a drain pipe 18 for removing water droplets collected from the dew condensation part 15 to the outside of the headlamp.

Here, FIG. 5 shows a configuration example of a drive control circuit of the forced dew condensation device 12. In the figure, 19 is a power source such as a battery mounted on the vehicle, 20 is a fuse, and 21 is an ignition switch. The forced dew condensation device 12 is appropriately ON / OFF driven and controlled by such a control circuit.

The fogging preventing device for an automobile headlamp according to the present invention is configured as described above, and its operation will be described below. When the lamp system including the headlamp body 1, the clearance lamp 2 and the fog lamp 10 is turned on, heat generated from the bulbs 1a, 2a and 10a locally heats the surrounding air. Then, the heated air flows to the dummy portion 6a to form air convection as indicated by an arrow in FIG. Here, the forced dew condensation device 12 is installed on the back surface side of the reflector 4 of the dummy part 6 a, and the hot and humid air passes through the dew condensation part 15 of this forced dew condensation device 12. In this case, by driving the strong dew condensation device 12 and turning on the thermoelectric element 13, the dew condensation part 15 that is in close contact with the low temperature surface 13b of the thermoelectric element 13 via the cooling surface 14 is cooled to a low temperature. Is becoming Therefore, when the hot and humid air passes through the dew condensation part 15, it is cooled and condensed by the dew condensation part 15. Water droplets are generated by this dew condensation and adhere to the dew condensation portion 15. The water drops fall from the dew condensation part 15, are collected by the water drop receiver 16, and are further discharged to the outside of the headlamp by the drain pipe 17.

The convective air that has passed through the dew condensation portion 15 in this way is dehumidified. Further, the dehumidified air then passes through the surface side of the reflector 4. In this case, the surface side of the reflector 4 is heated by the high temperature surface 13a of the thermoelectric element 13 and therefore has a high temperature. Therefore, the dehumidified air passes through the surface side of the reflector 4 and is heated, and the humidity thereof is further reduced. As described above, since the air inside the headlamp is dehumidified and heated by the forced dew condensation device 12 during the convection, it is possible to prevent clouding on the lens surface of the outer lens 6 or the like. In the above case, by forming the dew condensation part 15 of the forced dew condensation device 12 with a plurality of mesh slits 15a, a smooth air convection is formed without disturbing the convection air flowing therethrough. Air convection can be effectively used.

On the other hand, when the headlamp that has been turned on is turned off, the pressure inside the headlamp decreases, so hot and humid air is drawn into the headlamp through the breathing port 11. Then, as described above, the hot and humid air is dehumidified and heated by turning on the headlamp again. Therefore, also in this case, it is possible to prevent the occurrence of fogging.

[0018]

[Effect of the device]

 As described above, according to the present invention, it is possible to prevent the deterioration of the lamp performance such as the illuminance by effectively preventing the clouding in this type of headlamp. Then, it is possible to improve the quality of the vehicle by improving the appearance of the headlamp without clouding. Further, it has advantages that the restriction on the mounting position of the water droplet deposition device is eliminated and that an excellent effect can be exhibited especially when the vehicle is stopped.

[Brief description of drawings]

FIG. 1 is a plan view showing an overall configuration of a headlamp in an embodiment of an automobile headlamp fogging preventing device according to the present invention.

FIG. 2 is a perspective view of a forced dew condensation device according to the haze prevention device of FIG.

FIG. 3 is a partial plan view of a headlamp provided with the anti-fogging device shown in FIG.

FIG. 4 is an exploded perspective view of a forced dew condensation device according to the haze prevention device of FIG.

5 is a drive control circuit diagram in the anti-fogging device in FIG.

FIG. 6 is a plan view showing the overall configuration of a conventional automobile headlamp.

[Explanation of symbols]

 1 Head Lamp 1a Bulb 2 Clearance Lamp 2a Bulb 3 Reflector 4 Reflector 5 Housing 6 Outer Lens 7 Fender Panel 10 Fog Lamp 10a Bulb 11 Breathing Port 12 Forced Condensing Device 13 Thermoelectric Element 13a High Temperature Surface 13b Low Temperature Surface 14 Cooling Surface 15 Condensation Part 15a 16 Water drop receiver 17 Lead wire 18 Drain pipe

Claims (3)

[Scope of utility model registration request] 1. A headlamp comprising: an outer lens having a dummy part extending around to a fender panel; a lamp system to which the outer lens is attached; and a reflector for the lamp system, wherein the dummy part of the reflector is provided. A fog-prevention device for automobile headlamps, in which a forced dew condensation device is installed at the corresponding position, and the moisture in the lamp is condensed and removed by the above-mentioned forced dew condensation device using the air convection in the lamp. 2. The forced dew condensation device includes a thermoelectric element attached to the back surface of the reflector, a dew condensation part provided in close contact with a low temperature side of the thermoelectric element, and a water drop receiver installed below the dew condensation part. The anti-fog device for a headlamp for a vehicle according to claim 1, wherein the dew condensation part is arranged in air convection in the lamp. 3. The fog-preventing device for an automobile headlamp according to claim 2, wherein the dew condensation part is composed of a plurality of mesh slits.