JP4795094B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a so-called projector-type vehicle headlamp, and more particularly, to a vehicle headlamp configured to be able to irradiate an overhead sign.

  Generally, a projector-type vehicle headlamp reflects light from a light source disposed on an optical axis extending in the vehicle longitudinal direction toward the front by a reflector toward the optical axis, and this reflected light is directed to the front of the reflector. It is configured to irradiate the front of the lamp through the provided projection lens.

  When this projector-type vehicle headlamp is configured for low beam (passing beam) irradiation, a portion of the reflected light from the reflector is shielded between the projection lens and the reflector so that the upward irradiation light is By providing the shade to be removed, beam irradiation is performed forward with a low beam light distribution pattern having a predetermined cutoff line.

  In such a projector-type headlamp, the upward irradiation light is almost completely removed by the shade, so that the overhead sign (OHS) installed above the road surface in front of the vehicle cannot be seen well.

  Therefore, conventionally, in order to secure irradiation light for illuminating the overhead sign (overhead sign irradiation light), a substantially elliptical curved surface in which light from the light source is incident on the lower end edge of the projection lens at the upper front end of the reflector located above the shade. In addition, a reflection surface for overhead sign is integrally formed, and a prism portion that deflects and emits light incident from the reflection surface for overhead sign is formed at the lower end edge of the projection lens so as to be emitted from the prism portion. It has been proposed to use overhead sign irradiation light for irradiating overhead sign OHS (for example, see Patent Document 1).

  Further, as shown in FIG. 9, an overhead sign reflecting surface 105 that reflects light from the light source 102 toward a position slightly ahead of the shade 103 in the vicinity of the upper front end of the reflector 101 located above the shade 103. On the other hand, on the front side of the shade 103, an overhead sign light-receiving surface 106 that reflects the reflected light B1 from the overhead sign reflection surface 105 forward and upward is provided, and is incident on the projection lens 107 from the overhead sign light-receiving surface 106. The light B2 to be used is the overhead sign irradiation light B3 that irradiates the overhead sign (for example, see Patent Document 2).

Japanese Patent No. 3223797 JP 2001-35218 A

However, in the projector-type headlamp described in Patent Document 1, since the overhead sign reflecting surface is formed with a substantially elliptic curved surface, the light incident on the prism portion from the overhead sign reflecting surface is diffused light. Become.
Therefore, the overhead sign irradiation light emitted from the prism portion is in a state where various light beams having different emission angles are intermingled, and it is difficult to equalize the illuminance in the light distribution pattern by the overhead sign irradiation light. It was.

On the other hand, in the projector-type headlamp described in Patent Document 2, the path of the reflected light B1 reflected by the overhead sign reflecting surface 105 directly projects the reflected light as in Patent Document 1, as shown in FIG. Compared with the path 109 in the case where the light is incident on the lower edge of the lens, the path is closer to the shade 103 side by the angle α, and the reflection angle on the overhead sign reflecting surface 105 must be reduced.
However, when the overhead sign reflecting surface 105 having a small reflection angle is formed by injection molding, it is difficult to give a draft to the molding die, and when the overhead sign reflecting surface 105 is integrally formed with the reflector 101, the reflector The problem was that it was difficult to mold 101.

  Accordingly, an object of the present invention is to solve the above-mentioned problems, and it is possible to make the illuminance in the light distribution pattern by the overhead sign irradiation light uniform, and even when the overhead sign reflecting surface is formed integrally with the reflector. It is an object of the present invention to provide a vehicular headlamp that can ensure draft and improve the formability of a reflector.

An object of the present invention is to provide a projection lens disposed on an optical axis extending in the vehicle front-rear direction in a lamp chamber formed by a lamp body and a cover, and a light source disposed behind the rear focal point of the projection lens. And a reflector that reflects the direct light from the light source toward the optical axis toward the front, a part of the reflected light from the reflector disposed between the projection lens and the light source, and the light source A vehicle headlamp comprising: a shade that blocks a part of direct light to form a cut-off line of a light distribution pattern;
A reflection surface for an overhead sign that is provided in the vicinity of the reflector and reflects the light from the light source forward as substantially parallel light;
A prism part that is provided in front of the shade and that deflects and emits light from the overhead sign reflecting surface;
Equipped with a,
An opening through which light from the overhead sign reflecting surface is passed is formed below the shade,
Wherein for overhead sign reflecting surface and the prism portion is achieved by the vehicle headlamp is characterized that you have been placed on the same side with respect to the central axis of the projection lens.

According to the vehicle headlamp configured as described above, the overhead sign irradiation light for irradiating the overhead sign is formed by deflecting the light reflected by the overhead sign reflection surface to the upward light by the prism portion.
At this time, since the overhead sign reflecting surface causes the light from the light source to be incident on the prism portion as substantially parallel light, the light incident on the prism portion becomes a light beam having a uniform incident angle.
Therefore, even if the prism portion has a simple shape with a certain deflection angle, the overhead sign irradiation light emitted from the prism portion becomes a light beam bundle of light rays with uniform emission angles. Therefore, the illuminance in the light distribution pattern by the overhead sign irradiation light can be made uniform as compared with the case of a light bundle in which various light beams having different emission angles are mixed. Thereby, it becomes easy to realize overhead sign irradiation with high conformity to laws and regulations.

  The overhead sign reflecting surface sends direct light from the light source as substantially parallel light to the prism part in front of the position of the shade, so the inclination of the reflecting surface for overhead sign becomes a curved surface rising upward. When the overhead sign reflecting surface is molded integrally with the reflector, it becomes easy to secure a draft angle, and the moldability of the reflector can be improved.

In the vehicle headlamp having the above-described configuration, it is preferable that the prism portion is formed separately from the projection lens and disposed on the outer peripheral side of the projection lens.
According to the vehicle headlamp having such a configuration, the prism portion can be formed of a material having optical characteristics different from that of the projection lens, and it becomes easy to secure the deflection characteristics and the like necessary for upward illumination.

According to the vehicle headlamp according to the present invention, the overhead sign reflecting surface causes the light from the light source to enter the prism portion as substantially parallel light. Therefore, the light incident on the prism portion has a uniform incident angle. Become a bunch.
Therefore, even if the prism portion has a simple shape with a certain deflection angle, the overhead sign irradiation light emitted from the prism portion becomes a light beam bundle of light rays with uniform emission angles. Therefore, the illuminance in the light distribution pattern by the overhead sign irradiation light can be made uniform as compared with the case of a light bundle in which various light beams having different emission angles are mixed.

  The overhead sign reflecting surface sends direct light from the light source as substantially parallel light to the prism part in front of the position of the shade, so the inclination of the reflecting surface for overhead sign becomes a curved surface rising upward. When the overhead sign reflecting surface is molded integrally with the reflector, it becomes easy to secure a draft angle, and the moldability of the reflector can be improved.

Hereinafter, a preferred embodiment of a vehicle headlamp according to the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view of a vehicular headlamp according to a first embodiment of the present invention, FIG. 2 is an operation explanatory view of the lamp unit shown in FIG. 1, and FIG. 3 is a front view from the lamp unit shown in FIG. It is a figure which shows perspectively the main light distribution pattern and OHS light distribution pattern which are formed on the virtual vertical screen installed in the position of the lamp front 25m with the irradiated light.

  As shown in FIG. 1, the vehicle headlamp 10 according to the first embodiment includes a lamp body 12 and a lamp chamber 16 formed by a transparent transparent cover (cover) 14 attached to the front opening thereof. In addition, a lamp unit 18 is accommodated.

As shown in FIG. 1, the lamp unit 18 is supported by the lamp body 12 via an aiming mechanism 22.
The aiming mechanism 22 is a mechanism for finely adjusting the mounting position and the mounting angle of the lamp unit 18. At the stage of aiming adjustment, the lens central axis (optical axis) Ax of the lamp unit 18 is It extends in the downward direction by about 0.5 to 0.6 degrees.

  The lamp unit 18 is a projector-type lamp unit as shown in FIGS. 1 and 2, and includes a projection lens 11 disposed on a lens central axis (optical axis) Ax extending in the vehicle front-rear direction, and the projection lens 11. A light source bulb 23 arranged behind the rear focal point F2, a reflector 25 for reflecting light (direct light) emitted from the light source 23a of the light source bulb 23 toward the lens center axis Ax, and projection A shade 29 that is arranged between the lens 11 and the light source 23a and shields a part of the reflected light from the reflector 25 and a part of the direct light from the light source 23a to form a cut-off line of the light distribution pattern by the main light distribution. A substantially cylindrical holder 31 interposed between the projection lens 11 and the opening edge of the front end of the reflector 25 and serving as a connecting means between them, and provided in the vicinity of the reflector 25. The overhead sign reflecting surface 25b that reflects light from the light source 23a as substantially parallel light and reflects forward from the rear focal point F2, and the parallel light from the overhead sign reflecting surface 25b that is provided in front of the shade 29 is directed upward. And a prism portion 28 that irradiates the light with a deflection.

The projection lens 11 is a plano-convex lens having a convex front surface and a flat rear surface, and projects the focal plane elephant including the rear focal point F2 forward as an inverted elephant.
The light source bulb 23 is a discharge bulb such as a metal halide bulb having a discharge light emitting portion as the light source 23a. In this embodiment, the light source bulb 23 is disposed at the rear end portion of the reflector 25 with the bulb axis aligned with the lens center axis Ax. Insertion is fixed.
A halogen bulb or the like can be used in place of the discharge bulb, and the light source bulb 23 can be inserted and fixed from the side of the reflector 25 with the bulb axis substantially intersecting the lens center axis Ax.

  Here, the concept of the “substantially intersecting direction” includes, of course, a case where the optical axis of the light source bulb 23 is arranged orthogonal to the lens center axis Ax extending in the vehicle front-rear direction. In addition, a case where the lens center axis Ax is three-dimensionally crossed and a case where the lens center axis Ax is inclined by about ± 15 ° with respect to a horizontal line in the vehicle width direction are included.

The reflector 25 has a substantially elliptical reflecting surface 25a having a lens central axis Ax passing through the light source 23a as a central axis.
The reflecting surface 25a has a cross-sectional shape including the lens center axis Ax set to a substantially elliptic curved surface in which the central position of the light source 23a is the first focus F1 and the vicinity of the rear focus F2 of the projection lens 11 is the second focus. As shown in FIG. 2, the light from the light source 23a is focused and reflected toward the lens center axis Ax toward the front. The eccentricity of the reflecting surface 25a is set to gradually increase from the vertical cross section toward the horizontal cross section.

  The shade 29 is formed integrally with the holder 31 so that the upper end edge 29a is located in the vicinity of the lens center axis Ax in the vicinity of the rear focal point F2 of the projection lens 11, and as shown in FIG. In addition, a cut-off line CL of the light distribution pattern Pm by the main light distribution is formed.

  The holder 31 is formed in a cylindrical shape extending forward from the front end opening of the reflector 25, and the lens 11 is fixedly supported on the front end of the holder 31. The rear end portion of the holder 31 is fixed to the reflector 25 with screws at a plurality of locations.

The overhead sign reflecting surface 25b is integrally formed with the reflector 25 as a reflecting surface smoothly continuing to the end of the reflecting surface 25a of the reflector 25. And the upper opening edge vicinity of the reflective surface 25a of the reflector 25 is formed in the parabola type reflective surface which makes the 1st focus F1 which is the center position of the light source 23a a focus in a vertical cross section.
Accordingly, the overhead sign reflecting surface 25b continuous to the upper opening edge of the reflecting surface 25a can be easily formed into a curved surface inclined upward in the forward direction, and a draft angle during molding can be easily provided. Therefore, the overhead sign reflecting surface 25b can be integrally formed with the reflector 25, and the molded part can be simplified.

The prism portion 28 of the present embodiment is configured by a lens step formed integrally with the projection lens 11. When the reflected light B4 from the overhead sign reflecting surface 25b is received, the prism portion 28 is deflected forward and emitted. The overhead sign irradiating light B5 for irradiating the overhead sign is used.
As shown in FIG. 3, the overhead sign irradiation light B5 emitted from the prism unit 28 forms a light distribution pattern PX for overhead sign irradiation above the light distribution pattern Pm by the main light distribution.

According to the vehicle headlamp 10 of the first embodiment described above, the overhead of irradiating an overhead sign by deflecting the light B4 reflected by the overhead sign reflecting surface 25b into upward light by the prism portion 28. Sign irradiation light B5 is formed.
At that time, the overhead sign reflecting surface 25b causes the light from the light source 23a to be incident on the prism unit 28 as substantially parallel light, so that the light incident on the prism unit 28 becomes a light beam having a uniform incident angle.

  Therefore, even if the prism portion 28 has a simple shape with a certain deflection angle, the overhead sign irradiation light B5 emitted from the prism portion 28 becomes a light beam bundle of light rays with uniform emission angles. Therefore, the illuminance in the light distribution pattern Px by the overhead sign irradiation light B5 can be made uniform as compared with the case of a light bundle in which various light beams having different emission angles are mixed. Thereby, it becomes easy to realize overhead sign irradiation with high conformity to laws and regulations.

  The overhead sign reflecting surface 25b sends the direct light from the light source 23a as substantially parallel light to the prism portion 28 ahead of the position of the shade 29, so that the inclination of the overhead sign reflecting surface 25b rises forward. Therefore, when the overhead sign reflecting surface 25b is formed integrally with the reflector 25, it becomes easy to secure a draft, and the formability of the reflector 25 can be improved.

  Further, in the vehicle headlamp 10 of the present embodiment, the vicinity of the opening edge of the reflector 25 provided with the overhead sign reflection surface 25b has a parabolic reflection surface in the vertical cross section. Even when the surface 25b is a reflection curved surface that is smoothly continuous with the reflection surface 25a of the reflector 25, the overhead sign reflection surface 25b is inclined away from the lens center axis Ax toward the front of the vehicle, and has a larger draft. Thus, the moldability during injection molding can be further improved.

  4 is a longitudinal sectional view of a vehicle headlamp according to a second embodiment of the present invention, FIG. 5 is an operation explanatory view of the lamp unit shown in FIG. 4, and FIG. 6 is a front view from the lamp unit shown in FIG. It is a figure which shows perspectively the main light distribution pattern and OHS light distribution pattern which are formed on the virtual vertical screen installed in the position of the lamp front 25m with the irradiated light.

The vehicle headlamp 34 of the second embodiment uses a lamp unit 35 instead of the lamp unit 18 in the vehicle headlamp 10 of the first embodiment described above.
The lamp unit 35 is obtained by improving a part of the lamp unit 18, and the configuration other than the use of the shade 36 instead of the shade 29 shown in the first embodiment is the same as that in the first embodiment. is there. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the shade 36 of the second embodiment, the upper edge 36a is disposed in the vicinity of the rear focal point F2 of the projection lens 11 between the projection lens 11 and the light source 23a, and a part of the reflected light from the reflector 25 and the light source 23a. This is similar to the shade 29 of the first embodiment in that a part of the direct light from the light is shielded to form a cut-off line of the light distribution pattern by the main light distribution.

However, the shade 36 according to the second embodiment is a separate product from the holder 31, and the shade 36 receives light B4 from the overhead sign reflecting surface 25b toward the prism portion 28 as shown in FIG. An opening 37 through which it passes is provided.
Further, the shade 36 is integrally provided with a shielding portion 38 that shields the reflected light B6 and B7 from the reflector 25 toward the opening 37.

In the vehicle headlamp 34 according to the second embodiment, as shown in FIG. 6, the upper end edge 36a of the shade 36 forms a cut-off line CL of the light distribution pattern Pm by the main light distribution.
Further, the parallel light B4 reflected by the overhead sign reflecting surface 25b is emitted upward as the overhead sign irradiation light B5 from the prism portion 28, and forms the OHS light distribution pattern PX shown in FIG.

  In this case, the OHS light distribution pattern PX is narrowed down by the opening 37 formed in the shade 36 by the reflected light B4 from the overhead sign reflecting surface 25b, and has a substantially uniform illuminance irradiation area with a contour shape corresponding to the shape of the opening 37. P2 and a low-illuminance irradiation region P1 formed around the irradiation region P2 by light diffraction.

According to the vehicle headlamp 34 of the second embodiment, the light bundle incident on the prism portion 28 is restricted to only the parallel light from the overhead sign reflecting surface 25b, and a stable light bundle with uniform incident angles is obtained. can do.
Therefore, even if the prism portion 28 has a simple shape with a certain deflection angle, the overhead sign irradiation light B5 emitted from the prism portion 28 becomes a light bundle of light beams with uniform emission angles, and is generated by the overhead sign irradiation light B5. The illuminance in the light distribution pattern can be made uniform. Thereby, it becomes easy to realize overhead sign irradiation with high conformity to laws and regulations.

In addition, since the reflected lights B6 and B7 from the reflector 25 toward the opening 37 of the shade 36 are blocked by the shielding portion 38 provided on the shade 36, the reflected lights B6 and B7 pass through the opening 37 of the shade 36 and are the projection lens. 11 to prevent glare light from entering.
Therefore, the illuminance in the OHS light distribution pattern PX by the overhead sign irradiation light B5 can be made uniform and glare can be reliably prevented.

Note that the reflection direction of the overhead sign reflecting surface 25b and the arrangement of the prism portion 28 with respect to the position of the overhead sign reflecting surface 25b are not limited to the form shown in the above embodiment.
In the above-described embodiment, the overhead sign reflecting surface 25b is disposed at a part of the opening edge of the reflector 25, and the prism portion is disposed on the side facing the lens central axis Ax with respect to the position of the overhead sign reflecting surface 25b. 28 was provided.
However, like the lamp unit 41 of the vehicle headlamp according to the third embodiment of the present invention shown in FIG. 7, an opening 47 through which the reflected light from the overhead sign reflecting surface 25b is formed below the shade 46. The overhead sign reflecting surface 25b and the prism portion 28 may be arranged on the same side with respect to the lens central axis Ax.

In such a case, the main light distribution light path incident on the projection lens 11 from the reflector 25 and the overhead sign reflecting surface 25b continuous with the lower opening edge of the reflecting surface 25a enter the prism unit 28. Since the path of the reflected light is greatly separated, there is no possibility that the reflected light of the reflector 25 will enter the prism portion 28 through the opening 47, so the equipment of the shielding portion shown in the second embodiment is omitted, The shape of the shade 46 can be simplified.
Although the overhead sign reflecting surface is desirably provided at the upper opening edge or the lower opening edge as shown in the above embodiment, it goes without saying that it can be provided at the left and right opening edges.

Further, the configuration of the prism unit with respect to the projection lens is not limited to the configuration of the above embodiment.
In each of the embodiments described above, the prism portion 28 is configured by a lens step and is incorporated into a part of the outer peripheral shape of the projection lens 11.
However, in the lamp unit 42 of the vehicle headlamp according to the fourth embodiment of the present invention shown in FIG. 8, after the prism portion 48 is formed separately from the projection lens 51, the lower end outer periphery of the projection lens 51 is formed. The projection lens 51 is partly assembled and integrated with the outer periphery of the projection lens 51. Then, upon receiving the reflected light B4 from the overhead sign reflecting surface 25b, the prism portion 48 deflects forward and emits it, and becomes the overhead sign irradiated light B5 that irradiates the overhead sign.

  Therefore, in the lamp unit 42 of the present embodiment, the prism portion 48 is formed separately from the projection lens 51 and arranged on the outer peripheral side of the projection lens 51. Therefore, the prism portion 48 can be formed of a material having optical characteristics different from that of the projection lens 51, and it becomes easy to secure a deflection characteristic and the like necessary for upward irradiation, and the design of the prism portion 48 and the projection lens 51 is facilitated. The degree of freedom can be improved.

  The configurations of the lamp body, the cover, the projection lens, the light source, the reflector, the shade, the overhead sign reflecting surface, the overhead sign light receiving surface, the prism portion, and the like according to the vehicle headlamp of the present invention are the configurations of the above embodiment. Needless to say, the present invention is not limited to the above, and various forms can be adopted based on the gist of the present invention.

It is a longitudinal cross-sectional view of the vehicle headlamp which concerns on 1st Embodiment of this invention. It is operation | movement explanatory drawing of the lamp unit shown in FIG. It is a figure which shows perspectively the main light distribution pattern and OHS light distribution pattern which are formed on the virtual vertical screen installed in the position of the lamp front 25m with the light irradiated ahead from the lamp unit shown in FIG. It is a longitudinal cross-sectional view of the vehicle headlamp which concerns on 2nd Embodiment of this invention. It is operation | movement explanatory drawing of the lamp unit shown in FIG. It is a figure which shows perspectively the main light distribution pattern and OHS light distribution pattern which are formed on the virtual vertical screen installed in the position of the lamp front 25m with the light irradiated ahead from the lamp unit shown in FIG. It is a longitudinal cross-sectional view of the lamp unit of the vehicle headlamp which concerns on 3rd Embodiment of this invention. It is a longitudinal cross-sectional view of the lamp unit of the vehicle headlamp which concerns on 4th Embodiment of this invention. It is a principal part longitudinal cross-sectional view of the conventional vehicle headlamp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle headlamp 11 Projection lens 12 Lamp body 14 Transparent cover (cover)
16 lamp chamber 18 lamp unit 22 aiming mechanism 23 light source bulb 23a light source 25 reflector 25a reflecting surface 25b reflecting surface for overhead sign 28 prism portion 29 shade 29a upper end edge

Claims (2)

In a lamp chamber formed by a lamp body and a cover, a projection lens disposed on an optical axis extending in the vehicle front-rear direction, a light source disposed behind a rear focal point of the projection lens, and a direct light from the light source One of the reflected light from the reflector disposed between the projection lens and the light source, and a reflector having a substantially elliptical spherical shape with the optical axis as a central axis that reflects light toward the optical axis toward the front. A vehicular headlamp comprising: a part and a shade that forms a cut-off line of a light distribution pattern by shielding a part of direct light from the light source,
A reflection surface for an overhead sign that is provided in the vicinity of the reflector and is a parabolic reflection surface focused on the light source that reflects light from the light source forward as substantially parallel light;
A prism part that is provided in front of the shade and that deflects and emits light from the overhead sign reflecting surface;
With
An opening through which light from the overhead sign reflecting surface is passed is formed below the shade,
The vehicular headlamp, wherein the overhead sign reflecting surface and the prism portion are arranged on the same side with respect to a central axis of the projection lens. The vehicle headlamp according to claim 1 , wherein the prism portion is formed separately from the projection lens and disposed on an outer peripheral side of the projection lens.

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