JPS6114081Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a headlamp for a vehicle. More specifically, the present invention relates to the structure of a vehicle headlamp in which a shielding plate is attached to a movable reflector.

A lamp chamber is formed by a plastic housing and a transparent lens covering the front opening of the housing, and a reflector to which a light source bulb is bonded is supported in the lamp chamber so as to be tiltable so as to adjust the projection angle. Vehicle headlights are commonly used. This type of front light is called a "movable reflector" headlight. This reflector is made of plastic and has a reflective surface in the shape of a paraboloid of revolution on its inner wall.The surface of the reflective surface is covered with a reflective film such as aluminum coating by vapor deposition, etc., and the light source bulb is The light is reflected by a reflective film and projected forward.

FIG. 1 shows a cross-sectional perspective view of an example of such a movable reflector headlamp. As seen in the figure,
A lens 2 is attached via a gasket 3 to cover the front opening of a plastic housing 1 to form a box-shaped light chamber, and a plastic reflector 5 with a bulb 4 mounted inside the light chamber can be tilted. (tilting mechanism not shown). Generally, the reflector 5 has a rear wall 6 formed as the substantially paraboloid of revolution reflecting surface due to its shape (particularly in the case of a rectangular headlamp as shown in the illustrated example), and an upper wall 7 and a lower wall 8 that are continuous with the rear wall 6. is formed into a substantially horizontal flat plate shape. In a reflector with such a configuration, since the distance from the light source bulb 4 to the upper and lower walls is short, the upper and lower wall portions (especially the upper wall 7) may be deformed or exposed to heat from the light source. It also deteriorates and discolors when exposed to light. Furthermore, this thermal influence extends to the reflective surface 6 of the rear wall, lowering the reflective efficiency and inhibiting the light projection performance of the headlamp.

In order to eliminate such problems, reflector 5
Metal heat shields are also installed inside. However, the conventional mounting structure for the shielding plate is such that a rail-shaped guide piece having an L-shaped cross section or the like is protruded from inside the upper wall 7 of the reflector, and the metal heat shielding plate is held by the guide piece. It was hot. Since the structure is such that the guide piece protrudes inside the reflector and the heat shield plate is attached to it, the protruding guide piece must be continuous to the reflective surface of the rear wall 6 due to the design of the mold for forming the plastic reflector. Moreover, since the heat shield plate is provided to protrude inside the reflector, the effective reflection surface of the reflector is forced to become narrow, which adversely affects light distribution and reduces light projection performance. Furthermore, the guide piece may be deformed due to the thermal influence of the light source, causing the heat shield plate to fall off.

The present invention solves the above-mentioned problems and can effectively eliminate the heat influence on the reflector.
Furthermore, the present invention is intended to provide a structure for a vehicle headlamp that does not impede light projection performance. That is, the present invention provides a movable reflector headlamp as described above, in which a notch is provided in the portion of the upper wall of the reflector that faces the bulb, and a metal heat shield plate is provided between the upper wall of the reflector and the upper wall of the housing. The main point is that the

The configuration of the present invention will be explained below based on the drawings.

FIG. 2 is a cross-sectional perspective view showing one embodiment of the vehicle headlamp of the present invention, and FIG. 3 is a side cross-sectional view of the same. FIG. 4 is a perspective view of a reflector used in the present invention. As seen in the figure, the upper wall 7 of the reflector 5 formed by the housing 1 and the lens 2,
A notch 9 is provided in a portion facing the valve 4. This is a cutout of the part of the upper wall 7 of the reflector 5 that reaches the highest temperature during lighting and is affected by heat.
Although it is a slightly elongated notch extending from the front edge toward the rear wall 6, it can also be a round hole.

Reflector top wall 7 and housing 1 top wall 10
A heat shield plate 11 made of a metal plate is arranged at a position corresponding to the notch 9 between the two.
This heat shield plate 11 is for preventing the influence of the heat dissipated to the outside of the reflector 5 through the notch 9 on the housing 1 . In the figure, the heat shield plate 11 is arranged along the inner surface of the upper wall 10 of the housing 1, but it can also be provided along the outer surface of the upper wall 7 of the reflector 5. However, the notch 9
The larger the distance between the reflector and the heat shield plate 11, the better the heat dissipation effect due to convection, and the temperature inside the reflector can be lowered.

FIG. 5 shows an example of how the heat shield plate 11 is attached. In this example, L-shaped guides 12, 12 are made to protrude from the inner surface of the housing upper wall 10, and a heat shield plate 1
1 is held here. Heat shield plate 11
As shown in the plan view of FIG. 6, it may be a metal flat plate with a simple shape such as a rectangular shape, but the side edges of the metal plate may be provided with locking protrusions 13 to prevent it from coming off as shown in the side view of FIG. It is preferable to provide a stopper 14 on 13 or 13a, 13a and its edge. Note that the heat shield plate 11 is located at the notch 9 of the reflector.
It goes without saying that it is better to have a larger area.

The present invention is constructed as explained above, and since the part of the reflector where the temperature rises the most is cut out, there is no risk of thermal deformation of the plastic reflector, deterioration due to heat and light, discoloration, and deterioration of the surface treatment material. , peeling etc. can be avoided. Further, since heat is dissipated to the outside of the reflector through the notch, the temperature inside the reflector decreases, and the above effect is further aggravated. The influence of the heat dissipated outside the reflector on the plastic housing is prevented by the position of the heat shield. The metal heat shield plate has an extremely simple shape and can be easily manufactured by press working, etc., and the cutout portion of the reflector can be formed during molding, so there is no particular increase in manufacturing costs. Furthermore, there is no problem with cutting out a part of the upper wall of the reflector since that part is ineffective in terms of light distribution as a lamp; on the contrary, it is better to cut out a heat shield plate inside the reflector as in the conventional product. Since it is not installed, it has superior effects compared to conventional products in both light distribution performance and heat dissipation effect.
As described above, the present invention has many practical advantages and is extremely useful.

[Brief explanation of the drawing]

Figure 1 shows a vehicle headlight with a movable reflector.
FIG. 2 is a cross-sectional perspective view showing one embodiment of the vehicle headlamp of the present invention, FIG. 3 is a side cross-sectional view thereof, and FIG. 4 is one of the reflectors of the present invention. FIG. 5 is a front view showing the mounting structure of the heat shield plate according to the present invention, FIG. 6 is a plan view of the heat shield plate, and FIG. 7 is a side view of the heat shield plate. 1...Housing, 2...Lens, 3...Packskin, 4...Bulb, 5...Reflector, 6...
... Rear wall, 7 ... Upper wall, 8 ... Lower wall, 9 ... Notch, 10 ... Housing upper wall, 11 ... Heat shield plate,
12... L-shaped guide, 13, 13a... Locking protrusion, 14... Stopper.

Claims (1)

[Scope of utility model registration request] A vehicle headlamp comprising a reflector having a bulb attached thereto is tiltably supported in a lamp chamber formed by a housing and a lens covering a front opening thereof, wherein a notch is provided in a portion of the upper wall of the reflector facing the bulb. What is claimed is: 1. A headlamp for a vehicle, characterized in that a metal heat shield plate is disposed between the reflector top wall and the housing top wall.