JP5650570B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a vehicle headlamp.

  2. Description of the Related Art Conventionally, as a vehicle headlamp such as an automobile headlight, a so-called projector type lamp is known in which light emitted from a bulb is reflected by a reflector and projected to the front of the vehicle by a projection lens.

  In this projector-type vehicle headlamp, the bulb is inserted and fixed from the rear side of the reflector with the bulb extending in the front-rear direction along the optical axis of the projection lens extending in the front-rear direction. The structure was common. In recent years, a vehicular headlamp having such a structure has a structure in which the lamp is made compact in the front-rear direction by adopting a structure in which the bulb is inserted and fixed to the reflector from the side so as to be orthogonal to the optical axis. It has been proposed (see, for example, Patent Document 1).

  By the way, the light emitted from the bulb has the largest amount of light in the direction orthogonal to the axial direction (extending direction) of the bulb, and the smallest amount of light in the axial direction. For this reason, in the structure in which the bulb is inserted into the reflector from the side, the amount of incident light on the side region located on the front side in the axial direction of the bulb on the reflecting surface of the reflector is reduced, making it difficult to ensure the brightness of the light distribution pattern. Become. In particular, when a low beam is formed as a light distribution pattern, it is more difficult to ensure brightness because part of the reflected light from the reflector is shielded by the shade.

  Therefore, in the vehicle headlamp described in Patent Document 2, as shown in FIG. 6, the bulb 82 is inserted from the side (left side) into the reflector 83 so as to be orthogonal to the optical axis Ax of the projection lens 81, A first additional reflector 85 is provided between the bulb 82 and the shade 84, and a second additional reflector 86 is provided in a side region located on the front (right side) of the bulb 82 in the axial direction of the reflecting surface 83 a of the reflector 83. ing. As indicated by the arrows in the figure, the direct light from the bulb 82 is reflected backward by the first additional reflector 85 and further reflected forward by the second additional reflector 86 to irradiate the front of the vehicle.

  With such a configuration, in the vehicle headlamp described in Patent Document 2, the side region of the reflecting surface 83a with a small amount of light that is directly incident from the bulb 82 is used as the second additional reflector 86, and the shade 84 is originally used. By effectively using the light that should be shielded by the first additional reflector 85 and the second additional reflector 86, the luminous flux used is increased to ensure the brightness of the light distribution pattern.

Japanese Utility Model Publication No. 2-47704 JP-A-2005-1000076

  However, in the vehicle headlamp described in Patent Document 2, since the first additional reflector 85 is simply disposed between the bulb 82 and the shade 84, the space around the bulb 82 becomes narrow. As a result, heat generated from the valve 82 is hardly dissipated and the temperature around the valve 82 rises.

  The present invention has been made in view of the above circumstances, and in a projector-type vehicle headlamp that forms a low beam as a light distribution pattern, even if the bulb is inserted from the side of the reflector, the light distribution pattern An object of the present invention is to provide a vehicular headlamp that can suppress the temperature rise around the bulb while ensuring the brightness of the lamp.

In order to solve the above-mentioned problem, the invention described in claim 1
A projection lens having an optical axis along the front-rear direction;
A bulb having a bulb axis disposed behind the projection lens and extending along a direction substantially perpendicular to the optical axis;
A reflector having a reflecting surface that is disposed so as to cover the bulb from the rear and reflects the light emitted from the bulb forward;
A shade that is disposed between the projection lens and the bulb and shields part of the light reflected by the reflecting surface of the reflector;
A first additional reflecting surface that is disposed in front of the bulb and reflects light emitted from the bulb forward in the axial direction of the bulb;
A second additional reflection surface that is disposed in front of the bulb in the axial direction and reflects the light reflected by the first additional reflection surface forward toward the projection lens;
In a vehicle headlamp that forms a low beam in front of the vehicle,
The shade has an upper end bent backward, and forms a cut-off line of the low beam by a rear end edge of the upper end.
The first additional reflection surface is disposed below the upper end portion of the shade and ahead of the rear end edge.

The invention according to claim 2 is the vehicle headlamp according to claim 1,
The first additional reflection surface is formed on a rear surface of the shade.

According to the present invention, a projection lens having an optical axis along the front-rear direction, a valve having a valve shaft disposed behind the projection lens and extending along a direction substantially orthogonal to the optical axis, and the valve rearward A reflector disposed so as to cover the light source, a shade disposed between the projection lens and the bulb, and a first additional reflection that is disposed in front of the bulb and reflects light emitted from the bulb forward in the axial direction of the bulb. And a second additional reflection surface that is disposed in front of the bulb in the axial direction and reflects light reflected by the first additional reflection surface to the front projection lens, so that the light emitted from the bulb toward the shade Are sequentially reflected by the first additional reflection surface and the second additional reflection surface and irradiated from the projection lens to the front of the vehicle.
As a result, the first additional reflective surface and the second additional reflective surface can be used to transmit light that should be shielded by the shade while using the axially forward region of the bulb with a small amount of light directly incident from the bulb as the second additional reflective surface. Therefore, the brightness of the light distribution pattern can be ensured by increasing the light flux used. Therefore, even if the bulb is inserted from the side of the reflector so that the bulb axis is substantially orthogonal to the optical axis, the brightness of the light distribution pattern can be ensured.

  Further, the first additional reflection surface arranged in front of the bulb is below the upper end of the shade bent rearward and ahead of the rear edge of the upper end forming the low beam cut-off line. Therefore, the first additional reflective surface is more integrated with the shade than the conventional case where the first additional reflector (first additional reflective surface) is simply disposed between the bulb and the shade. can do. Therefore, compared with the prior art, a large space can be secured between the bulb and the shade, and therefore, heat dissipation from the bulb can be promoted and temperature rise around the bulb can be suppressed.

It is a perspective view of the vehicle headlamp in an embodiment. It is a top view of the vehicle headlamp in the embodiment. It is sectional drawing in the ABCDEF line of FIG. It is a rear view of the shade in an embodiment. It is sectional drawing which shows another example of the vehicle headlamp in embodiment. It is sectional drawing in the top view of the conventional vehicle headlamp.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a vehicle headlamp 1 according to the present embodiment, FIG. 2 is a top view of the vehicle headlamp 1, and FIG. 3 is a cross-sectional view taken along the ABCDEF line in FIG. is there.
In the following description, unless otherwise specified, the descriptions of “front”, “rear”, “left”, “right”, “upper”, and “lower” refer to the direction viewed from the vehicle headlamp 1, It shall be used corresponding to the description in the drawing.

As shown in FIGS. 1 to 3, a vehicle headlamp 1 is a projector type that is mounted on a vehicle (not shown) and forms a low beam as a light distribution pattern in front of the vehicle, and includes a projection lens 2 and a bulb 3. A reflector 4, a shade 5, and a sub-reflector 6.
Among these, the projection lens 2 is a plano-convex lens having a convex front surface, and has an optical axis Ax along the front-rear direction. The projection lens 2 reversely projects an image on the focal plane including the rear focal point f1 on the optical axis Ax forward.

  The bulb 3 is a halogen lamp having a filament 31 and is arranged such that the bulb axis Ax1 extends substantially along the left-right direction. More specifically, the bulb 3 is located from the right side so that the rear focal point f1 of the projection lens 2 is behind and below the optical axis Ax, and the filament 31 is located directly below the optical axis Ax. It is inserted into the reflector 4 along the left-right direction, and is fixed to a later-described valve support 42 provided on the reflector 4. In the valve 3, the amount of emitted light in the direction orthogonal to the valve axis Ax1 is larger than the amount of emitted light in the direction along the valve axis Ax1.

  The reflector 4 has, for example, a curved concave plate shape that opens forward, and is disposed so as to cover the bulb 3 from the rear. A valve support 42 that supports the base end of the bulb 3 is provided on the right side below the optical axis Ax in the front surface of the reflector 4. Further, the reflector 4 has a shape in which a portion located in front of the direction along the valve axis Ax1 of the bulb 3 (hereinafter referred to as the valve axis Ax1 direction), that is, a left side portion below the optical axis Ax is cut away. Is formed.

  Of the front surface of the reflector 4, a portion excluding the right side portion where the valve support portion 42 is provided is a reflection surface 41 based on a spheroid. The reflection surface 41 reflects the light emitted from the bulb 3 forward toward the focal plane including the rear focal point f1 of the projection lens 2.

  The shade 5 is a light shielding plate erected so as to be orthogonal to the optical axis Ax, and is disposed between the projection lens 2 and the bulb 3 in a state where the vertical position of the upper end edge is substantially coincident with the optical axis Ax. ing. As for this shade 5, the upper end part 51 of the center in the left-right direction is bent back. The upper end 51 has the rear focal point f1 of the projection lens 2 in the vicinity of the rear end edge 51a, and the rear end edge 51a extends along the focal plane including the rear focal point f1 of the projection lens 2 along the optical axis. As it moves away from Ax to the left and right sides, it is curved so as to be positioned forward. With such a configuration, the shade 5 blocks part of the light reflected by the reflecting surface 41 of the reflector 4 and forms a cut-off line at the upper edge of the low beam as an inverted image of the rear edge 51a.

FIG. 4 is a rear view of the shade 5.
As shown in FIGS. 3 and 4, a first additional reflection surface 52 is formed on the rear surface (back surface) of the shade 5 in a portion slightly to the left and right. The first additional reflection surface 52 is formed in a spheroid shape in which the vicinity of the filament 31 is a first focal point f2 and a predetermined position between the shade 5 and the sub reflector 6 is a second focal point f3. The first additional reflection surface 52 reflects the light emitted from the bulb 3 obliquely leftward and backward toward the front of the bulb 3 in the direction of the bulb axis Ax1. Further, the first additional reflection surface 52 is disposed below the upper end portion 51 of the shade 5 and ahead of the rear end edge 51a. Thereby, since the first additional reflection surface 52 is disposed more integrally (compactly) with respect to the substantially flat shade 5, a wide space between the bulb 3 and the shade 5 can be secured. .

  As shown in FIGS. 1 to 3, the sub-reflector 6 is arranged on the left side of the reflector 4 and substantially in front of the valve 3 in the direction of the valve axis Ax <b> 1. ing. The second additional reflection surface 61 has a vertical cross-sectional shape orthogonal to the left-right direction, the second focus f3 of the first additional reflection surface 52 being the first focus, and the vicinity of the rear end edge 51a of the shade 5 being the second focus. The horizontal cross-sectional shape which is formed in an elliptical shape and is orthogonal to the vertical direction is formed in a parabolic shape having a focus in the vicinity of the second focal point f3 of the first additional reflection surface 52. Therefore, the second additional reflection surface 61 reflects the light reflected by the first additional reflection surface 52 forward so as to be condensed near the rear end edge 51a of the shade 5 in the vertical direction, and slightly in the horizontal direction. The light is reflected forward so as to be diffused light and directed toward the projection lens 2. The light reflected forward by the second additional reflection surface 61 is irradiated forward of the vehicle through the projection lens 2 and contributes to the formation of a light distribution pattern (low beam).

  As described above, according to the vehicle headlamp 1, the light emitted from the bulb 3 toward the shade 5 is sequentially reflected by the first additional reflection surface 52 and the second additional reflection surface 61, and is then emitted from the projection lens 2. Irradiated to the front of the vehicle. As a result, light that should be shielded by the shade 5 while originally using the region in front of the bulb 3 in the direction of the bulb axis Ax1 of the bulb 3 with a small amount of light incident directly from the bulb 3 is used as the first additional reflection surface. 52 and the second additional reflection surface 61 can be used effectively, so that the luminous flux used can be increased to ensure the brightness of the light distribution pattern (low beam). Therefore, even if the bulb 3 is inserted from the side of the reflector 4 so that the bulb axis Ax1 is substantially orthogonal to the optical axis Ax, the brightness of the light distribution pattern can be ensured.

  Also, the first additional reflection surface 52 formed on the rear surface of the shade 5 is below the upper end portion 51 of the shade 5 bent rearward, and the rear end edge of the upper end portion 51 that forms a low beam cut-off line. Since the first additional reflector corresponding to the first additional reflection surface 52 is simply arranged between the bulb and the shade, the first addition is made to the shade 5 because it is arranged in front of the 51a. The reflecting surface 52 can be disposed more integrally. Therefore, compared with the prior art, a wider space between the valve 3 and the shade 5 can be ensured, and therefore, heat dissipation from the valve 3 can be promoted to prevent an increase in temperature around the valve 3.

  Further, since the first additional reflection surface 52 is formed on the rear surface of the shade 5, the number of parts is larger than that of the conventional case where the first additional reflector corresponding to the first additional reflection surface 52 is provided separately from the shade. In addition, the positioning process of the first additional reflection surface 52 can be omitted (integrated with the positioning process of the shade 5), and the assembly work can be simplified.

  The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the first additional reflection surface 52 is integrally formed on the rear surface of the shade 5, but the first additional reflection surface 52 and the shade 5 may be separate. Specifically, as shown in FIG. 5, the second sub reflector 7 having the first additional reflection surface 52 may be provided separately from the shade 5. In this case, the first additional reflection surface 52 (second sub-reflector 7) is a predetermined region that is in front of the bulb 3, below the upper end portion 51 of the shade 5, and ahead of the rear end edge 51a. What is necessary is just to be arrange | positioned in R. However, it is preferable that the first additional reflection surface 52 (second sub-reflector 7) is as close as possible to the shade 5 in terms of securing a wider space around the bulb 3.

DESCRIPTION OF SYMBOLS 1 Vehicle headlamp 2 Projection lens Ax Optical axis 3 Valve | bulb 31 Filament Ax1 Valve | bulb axis | shaft 4 Reflector 41 Reflecting surface 42 Valve support part 5 Shade 51 Upper end part 51a Rear end edge 52 First additional reflective surface 6 Sub reflector 61 Second addition Reflective surface 7 Second sub-reflector

Claims (2)

A projection lens having an optical axis along the front-rear direction;
A bulb having a bulb axis disposed behind the projection lens and extending along a direction substantially perpendicular to the optical axis;
A reflector having a reflecting surface that is disposed so as to cover the bulb from the rear and reflects the light emitted from the bulb forward;
A shade that is disposed between the projection lens and the bulb and shields part of the light reflected by the reflecting surface of the reflector;
A first additional reflecting surface that is disposed in front of the bulb and reflects light emitted from the bulb forward in the axial direction of the bulb;
A second additional reflection surface that is disposed in front of the bulb in the axial direction and reflects the light reflected by the first additional reflection surface forward toward the projection lens;
In a vehicle headlamp that forms a low beam in front of the vehicle,
The shade has an upper end bent backward, and forms a cut-off line of the low beam by a rear end edge of the upper end.
The vehicle headlamp according to claim 1, wherein the first additional reflection surface is disposed below the upper end portion of the shade and ahead of the rear end edge.   The vehicle headlamp according to claim 1, wherein the first additional reflection surface is formed on a rear surface of the shade.

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