JPS6254201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicular headlamp, and more particularly to an improvement in a vehicular headlamp that effectively utilizes a beam emitted from a passing filament.

Conventionally, this type of vehicle headlight includes, for example,
As shown in FIG. 1, a reflecting mirror 1 having a paraboloid of rotation and a lens 2 covering the front opening of this reflecting mirror 1
A lamp unit L is formed, and a bulb 5 containing a running filament 3 and a passing filament 4 is installed in the lamp unit L.
The traveling filament 3 is placed at the focal point 6 of the reflecting mirror 1, and the passing filament 4 is placed on the main axis 7 of the reflecting mirror 1 and slightly forward of the focal point 6 of the reflecting mirror 1. (Refer to "Automotive Engineering Complete Book Volume 10, Electrical Components, Body Equipment, Engine Parts" published by Sankaido). According to this type, the beam irradiated from the traveling filament 3 is reflected by the reflector 1 and becomes a light beam approximately parallel to the main axis 7 of the reflector 1, so that it can be irradiated far in front of the vehicle body. In contrast,
The beam irradiated from the passing filament 4 is reflected by the reflecting mirror 1 and becomes a light beam directed toward the main axis 7 of the reflecting mirror 1, so that it irradiates the road surface in front of the vehicle body. A light shielding plate 8 is provided around the passing filament 4 and the traveling filament 3, and this light shielding plate 8 prevents the beams irradiated from each filament 3 and 4 from proceeding directly to the outside through the lens 2. At the same time, among the beams emitted from the passing filament 4, the light rays reflected by the lower half 1a of the reflector 1 and directed toward the main axis 7 of the reflector 1 (indicated by the dotted line in the center of FIG. This prevents dazzling light.

However, in such a conventional vehicle headlamp, the passing filament 4 is placed slightly forward of the focal point 6 of the reflecting mirror 1 so as not to block the beam emitted from the traveling filament 3. At the same time, a light shielding plate 8 is provided to prevent the generation of dazzling light to oncoming vehicles.
Since the reflection at Only the upper half 1b of the reflecting mirror 1 is used for the beam irradiated from the mirror 1, and the passing beam can only secure about half the amount of light compared to the traveling beam. For this reason, when the passing beam is used, the illuminance of the road surface in front of the vehicle body becomes low, which may give the driver a feeling of anxiety.

The present invention has been made in view of the above, and its object is to provide a reflecting mirror having a single paraboloid of rotation, and a predetermined amount of light vertically downward from the center of the main axis of the reflecting mirror. A lamp unit is formed with a lens that is deflected and covers the opening of the reflecting mirror, and the passing filament is placed behind the focal point of the reflecting mirror, and the upward direct rays emitted from the passing filament are By providing a light blocking plate, when using a passing beam, the reflection from the lower half of the reflector can be used, and at the same time, the amount of illumination to the road surface in front of the vehicle can be improved by using the direct light directed downwards in front of the vehicle. An object of the present invention is to provide a vehicle headlamp with improved performance.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

In the first embodiment shown in FIGS. 2 to 4,
A bulb 5 having a built-in filament 4 for passing is installed in a lamp unit L formed by a reflecting mirror 1 having a single paraboloid of revolution and a lens 2 covering the front opening of the reflecting mirror 1. The passing filament 4 is disposed on the main axis 7 of the reflecting mirror 1 and slightly behind the focal point 6 of the reflecting mirror 1. Here, the central axis 15 of the lens 2 is deviated vertically downward by a predetermined amount with respect to the main axis of the reflecting mirror 1, and accordingly, the reflecting mirror 1 is not a perfect paraboloid of revolution.
Only the lower half portion 1a is formed as a paraboloid of revolution, and the lower half portion 1a is formed to have a wider reflective surface than the upper half portion 1b.

A light shielding plate 10 is provided around the passing filament 4, and this light shielding plate 1
0, as shown in FIG.
2, and is arranged so as to cover the above-mentioned passing filament 4 from above. At this time,
The positional relationship between the light shielding plate 10 and the passing filament 4 is as shown in FIG. 4 when viewed from the front of the vehicle.
is completely hidden by the partition section 12. Therefore, among the beams irradiated from the passing filament 4, those directed toward the upper half 1b of the reflecting mirror 1 are directed to the light shielding plate 1 as shown in FIG.
The lens 2 is directly blocked by the cylindrical part 11 of the
The light directed toward the upper half 2b is blocked by the partition portion 12 of the light shielding plate 10.

Therefore, according to the vehicle headlamp according to this embodiment, a portion of the beam emitted from the passing filament 4 is directed toward the lower half of the reflector 1, as shown by the solid line in FIG. 1a, is reflected by the paraboloid of revolution of the reflector 1, and travels in the direction of expansion from the main axis 7 of the reflector 1, illuminating the road surface in front of the vehicle body, while other parts of the vehicle are illuminated by the As shown by the dotted chain line, the light directly advances to the outside from the lower half 2a of the lens 2 and illuminates the road surface. Therefore, when the passing beam is used, not only the light reflected by the reflecting mirror 1 but also the direct light from the passing filament 4 illuminates the road surface in front of the vehicle body, and the illumination effect can be improved. Furthermore, according to the vehicle headlamp according to this embodiment, when using the passing beam, the central axis of the lens is shifted downward, so that the upper half 1b of the reflector 1, which is not used as a reflecting surface at all, is minimized as much as possible. At the same time, the lower half 1a is made wide, so that the beam irradiated from the passing filament 4 is reflected by the reflecting mirror 1.
It is possible to effectively reflect the light at the lower half 1a of the light beam, and the irradiation efficiency can be further improved. In addition, since the central axis 15 of the lens 2 is deviated downward by a predetermined amount with respect to the reflecting mirror 1 and the main axis 7, the mounting position of the bulb 5 is moved upward by the amount of deviation 1, and the mounting position of the bulb 5 is moved upward by the amount of deviation l. During maintenance, etc., work can be carried out very easily from above after opening the hood (not shown). In this embodiment, the light distribution characteristics when using the passing beam are as shown in FIG. A vertical screen is provided, and a passing beam is irradiated onto this screen, and the horizontal line H and the vertical line V are reference lines corresponding to the position where the passing filament 4 is provided. In this light distribution characteristic, there is a beam that is irradiated upward from the horizontal line H, but this is based on the shape of the light shielding plate 10 shown in FIGS. The light will not dazzle, especially for oncoming vehicles. A line 13 indicated by a dashed line in the figure corresponds to the oblique side 14 of the partition portion 12 of the light shielding plate 10.

In the above embodiment, as shown in FIG. 4, the passing filament 4 is completely hidden by the partition part 12 of the light-shielding plate 10, but the invention is not necessarily limited to this. In other words, the lowermost line S of the light shielding plate 10 is positioned below the center line C of the passing filament 4 so that the partition portion 12 of the light shielding plate 10 covers more than half of the coil diameter of the passing filament 4. All you have to do is
From the passing filament 4 to the upper half of the lens 2
It is possible and desirable to block direct light directed toward b.

As described above, the vehicle headlamp according to the present invention includes a reflector having a single paraboloid of revolution, a center of which is vertically deviated downward by a predetermined amount from the main axis of the reflector, A lamp unit is formed with a lens that covers the aperture of the reflecting mirror, and the passing filament is placed behind the focal point of the reflecting mirror, and the direct upward rays of light emitted from this passing filament are blocked. When using the passing beam, the lower half of the reflector can be used as a reflecting surface, and the lower half of the reflector can be made larger by the amount that the lens is shifted vertically downward. Among the beams, the downward beam can be used as direct light, and the amount of light of the passing beam can be increased accordingly, making it possible to significantly improve irradiation efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional vehicle headlamp, FIG. 2 is a sectional view showing a first embodiment of a vehicle headlamp according to the present invention, and FIG. 3 is shown in FIG. FIG. 4 is a perspective view showing the light shielding plate in the embodiment, FIG. 4 is a front view seen from direction A in FIG. 3, and FIG. 5 is a diagram showing light distribution characteristics by the vehicle headlamp according to the embodiment in FIG. 2. It is. L...Lamp unit, 1...Reflector, 2...
Lens, 4... Filament for passing, 6...
Focal point, 7...principal axis, 10...shading plate, 15... central axis.

Claims (1)

[Claims] 1. A reflecting mirror 1 having a single paraboloid of rotation, and a lens 2 whose center line 15 is vertically deviated downward by a predetermined amount with respect to the main axis 7 of the reflecting mirror 1, and which covers the front opening of the reflecting mirror 1. A lamp unit L is formed, and a passing filament 4 is disposed within this lamp unit L so as to be located behind the focal point 6 of the reflecting mirror 1.
A vehicle headlamp characterized in that a light shielding plate 10 is provided to block an upward beam emitted from the vehicle headlamp.