JP4279162B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a so-called projector-type vehicle headlamp.

  In general, a projector-type vehicle headlamp has a projection lens arranged on an optical axis extending in the vehicle front-rear direction, and a light source arranged behind the focal point on the rear side. Is reflected near the optical axis by a reflector.

  In “Patent Document 1” and “Patent Document 2”, in such a projector-type vehicle headlamp, the light source is emitted by a light-emitting portion of a light source bulb inserted and fixed to a reflector from the side of the optical axis. A so-called side-insertion type lamp configuration is described.

  Further, in “Patent Document 3”, in a normal rear-insertion type projector-type vehicle headlamp, light from the light source is reflected toward an upper reflection region of the reflector at a position obliquely forward and downward of the light source. A lamp configuration provided with an additional reflector is described.

Japanese Utility Model Publication No. 2-47704 JP 2001-229715 A Japanese Utility Model Publication No. 5-72006

  If the side-insertion type lamp configuration as described in the above-mentioned “Patent Document 1” and “Patent Document 2” is adopted, the front-and-rear length of the lamp can be shortened to achieve a compact size.

  However, in the vehicle headlamps described in “Patent Document 1” and “Patent Document 2”, the light source bulb is inserted and fixed to the reflector on the same horizontal plane as the optical axis. There is.

  That is, in a projector-type vehicle headlamp, the region on the side of the optical axis on the reflecting surface of the reflector is suitable for forming a diffusion region of the light distribution pattern, but the light source bulb is on the same horizontal plane as the optical axis. If the light source bulb is inserted and fixed in the reflector, a hole for inserting and fixing the light source bulb is formed in the optical axis side region of the reflecting surface. Therefore, the optical axis side region is effectively used for light distribution control. Therefore, there is a problem that it is difficult to ensure sufficient brightness of the diffusion region of the light distribution pattern.

  The present invention has been made in view of such circumstances, and even in the case where a side-insertion type lamp configuration is adopted in a projector-type vehicle headlamp, the diffusion region of the light distribution pattern can be reduced. It is an object of the present invention to provide a vehicular headlamp that can sufficiently ensure brightness.

  According to the present invention, the above-described object is achieved by contriving the insertion and fixing position of the light source bulb with respect to the reflector and by providing a predetermined additional reflector.

That is, the vehicle headlamp according to the present invention is
A projection lens disposed on the optical axis extending in the vehicle front-rear direction, a light source disposed behind the rear focal point of the projection lens, and light from the light source is reflected toward the optical axis toward the front A vehicle headlamp comprising a reflector to be
The light source is composed of a light emitting part of a light source bulb inserted and fixed to the reflector from the side of the optical axis at a position spaced downward from the optical axis,
An additional reflector that reflects light from the light source toward an upper reflection region located above the optical axis in the reflector is provided at a position directly below the light source .
The reflecting surface of the additional reflector has a substantially W-shaped cross-sectional shape along a vertical cross-section perpendicular to the optical axis, and a substantially U-shaped cross-sectional shape along the vertical cross-section including the optical axis. Has been
The reflecting surface of the additional reflector, ing a plurality of diffuse reflection elements formed so as to extend to the left and right obliquely rearward from the optical axis in the plan view, it is characterized in.

  The light distribution pattern formed by light irradiation from the vehicle headlamp according to the present invention may be a low-beam light distribution pattern, a high-beam light distribution pattern, or any other distribution. It may be a light pattern.

  The type of the “light source bulb” is not particularly limited, and for example, a discharge bulb, a halogen bulb, or the like can be adopted.

  The light source bulb is inserted and fixed to the reflector at a “position away from the optical axis”, but the amount of downward displacement of the insertion fixed position from the optical axis is not particularly limited. At that time, the amount of downward displacement is set to a value of 10 mm or more from the viewpoint of preventing the light from the light source bulb reflected in the region near the optical axis on the reflecting surface of the reflector from being blocked by the light source bulb. It is preferable to set the value to 15 mm or more. On the other hand, from the viewpoint of sufficiently securing the incident light beam from the light source bulb to the reflecting surface of the reflector, it is preferable to set the downward displacement to a value of 30 mm or less.

  As shown in the above configuration, the vehicular headlamp according to the present invention is configured as a projector-type vehicular headlamp, and its light source bulb is inserted into the reflector from the side of the optical axis extending in the vehicle front-rear direction. Since it is fixed, the front-rear length of the lamp can be shortened to make it compact.

  At this time, since the light source bulb is inserted and fixed at a position away from the optical axis, the area on the side of the optical axis on the reflecting surface of the reflector can be effectively used for light distribution control. Then, a diffusion region of the light distribution pattern can be formed by the reflected light from the optical axis side region, and sufficient brightness can be secured in the diffusion region.

  In addition, an additional reflector that reflects light from the light source toward the upper reflection region located above the optical axis in the reflector is provided at a position directly below the light source, thereby spreading the light distribution pattern. The area can be made brighter.

  In addition, at this time, even if the additional reflector is disposed so as to be close to the light source, the light source is disposed at a position separated downward from the optical axis, so that light incident on the reflector from the light source and reflected from the reflector are reflected. It is possible to prevent the light from being blocked by the additional reflector, so that most of the downward emitted light from the light source can be reflected by the additional reflector and used for forming a light distribution pattern.

  As described above, according to the present invention, it is possible to sufficiently ensure the brightness of the diffusion region of the light distribution pattern even when the side-insertion-type lamp configuration is adopted in the projector-type vehicle headlamp. it can.

Moreover in the present invention, as a reflective surface shape of the additional reflector, together with the cross-sectional shape along a vertical section orthogonal to the optical axis is set to substantially W-shaped, substantially the cross-sectional shape along the vertical cross section including the optical axis Since it is configured to be U-shaped, the direction of the reflected light from the additional reflector does not greatly deviate from the direction of the light directly incident on the upper reflective area of the reflector from the light source. Incident light can be incident over a wide range of the upper reflective area of the reflector. As a result, the additional light distribution pattern formed by the reflected light from the additional reflector can have a large left-right diffusion angle and a substantially uniform light intensity distribution. The brightness of the diffusion region can be increased without causing light unevenness.

In addition the present invention, the reflective surface of the additional reflector, since Tsu Do a plurality of diffuse reflection elements formed so as to extend to the left and right obliquely rearward from the optical axis in plan view, the light reflected from the additional reflector, Since the light can be made to enter the upper reflection region of the reflector in a finely diffused state, the occurrence of uneven light distribution in the light distribution pattern can be more effectively suppressed.

  By the way, when the light source bulb is a discharge bulb, the downward emission light from the light source becomes yellowish due to iodide accumulated in the lower region of the discharge vessel, so that the incident light to the additional reflector is also Some of them become yellowish. However, as described above, if the reflected light from the additional reflector is incident on the upper reflection area of the reflector in a finely diffused state, it is effective to cause color unevenness in the additional light distribution pattern. Thus, it is possible to effectively suppress the occurrence of color unevenness even in the entire light distribution pattern.

  In general, the discharge bulb has a stay extending substantially parallel to the central axis of the bulb, and the stay is rotated by a predetermined angle around the central axis of the bulb with respect to a position directly below the central axis of the bulb. If the discharge bulb is inserted and fixed to the reflector, the downward emitted light from the light source can be incident on the additional reflector without being blocked by the stay, and thereby the brightness of the diffusion region of the light distribution pattern Can be further increased. At that time, the specific value of the “predetermined angle” is not particularly limited, but is preferably set to 30 ° or more from the viewpoint of effectively avoiding shielding of downward outgoing light from the light source. More preferably, it is set to 45 ° or more.

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

  FIG. 1 is a side sectional view showing a vehicle headlamp according to an embodiment of the present invention.

  As shown in the figure, a vehicle headlamp 10 according to this embodiment includes a front and rear of a vehicle in a lamp chamber formed by a lamp body 12 and a transparent translucent cover 14 attached to a front end opening of the lamp body 12. A lamp unit 20 having an optical axis Ax extending in the direction is accommodated via an aiming mechanism 50 so as to be tiltable in the vertical direction and the horizontal direction.

  When the aiming adjustment by the aiming mechanism 50 is completed, the optical axis Ax of the lamp unit 20 extends in a downward direction by about 0.5 to 0.6 ° with respect to the vehicle front-rear direction.

  2 and 3 are side sectional views showing the lamp unit 20 as a single item, FIGS. 4 and 5 are plan sectional views showing the lamp unit 20 as a single item, and FIG. 6 is a VI-VI line arrow in FIG. FIG.

  As shown in these drawings, the lamp unit 20 is a projector-type lamp unit, and includes a light source bulb 22, a reflector 24, a holder 26, a projection lens 28, a shade 32, and an additional reflector 34. It is prepared.

  The projection lens 28 is a plano-convex lens having a convex front surface and a flat rear surface, and is disposed on the optical axis Ax. The projection lens 28 projects an image on the focal plane including the rear focal point F forward as a reverse image.

  The light source bulb 22 is a discharge bulb such as a metal halide bulb having a discharge light emitting portion as a light source 22a. The light source 22a is configured as a line light source extending in the direction of the bulb central axis Ax1, and is substantially the same as the bulb central axis Ax1. The stay 22b extends in parallel.

  The light source bulb 22 is located behind the focal point F of the projection lens 28 and away from the optical axis Ax (for example, a position away from the optical axis Ax by about 20 mm) at the optical axis Ax. Are inserted and fixed to the reflector 24 from the right side. This insertion and fixing is performed in a state where the valve center axis Ax1 is set so as to extend in the horizontal direction in a vertical plane orthogonal to the optical axis Ax, and the stay 22b is positioned relative to the position directly below the valve center axis Ax1. The light emission center of the light source 22a is positioned vertically below the optical axis Ax while being rotated forward about 60 ° around the central axis Ax1.

  The reflector 24 has a reflecting surface 24a that reflects light from the light source bulb 22 forward and toward the optical axis Ax. The reflecting surface 24a has a substantially elliptical cross-sectional shape, and its eccentricity is set to gradually increase from the vertical cross section toward the horizontal cross section. As a result, as shown in FIGS. 2 and 4, the light from the light source 22a reflected by the reflecting surface 24a is substantially converged in the vicinity of the rear focal point F in the vertical section, and is converged in the horizontal section. The position is moved forward considerably.

  In the reflector 24, a valve insertion fixing portion 24 b is formed in the lower right region of the reflection surface 24 a so as to protrude from the reflection surface 24 a, and a valve insertion hole 24 c is formed in the left side surface portion of the valve insertion fixing portion 24 b. Is formed. The reflector 24 is supported by the lamp body 12 via an aiming mechanism 50 in aiming brackets 24d formed at the three locations.

  The holder 26 is formed so as to extend in a substantially cylindrical shape from the front end opening of the reflector 24 toward the front. The holder 26 is fixedly supported by the reflector 24 at the rear end and fixedly supports the projection lens 28 at the front end. is doing.

  The shade 32 is formed integrally with the holder 26 so as to be positioned in a substantially lower half portion in the internal space of the holder 26. The shade 32 is formed so that its upper edge 32 a passes through the rear focal point F of the projection lens 28, thereby blocking a part of the reflected light from the reflection surface 24 a of the reflector 24, thereby projecting the projection lens 28. Most of the upward light emitted forward from is removed.

  The additional reflector 34 is provided at a position directly below the light source 22 a and is supported by a support bracket portion 24 e formed at the lower end portion of the reflector 24. The reflection surface 34a of the additional reflector 34 is formed at a position approximately 20 to 30 mm away from the light source 22a, and the surface shape thereof is set to a substantially W-shaped cross-sectional shape along a vertical cross section orthogonal to the optical axis Ax. In addition, the cross-sectional shape along the vertical cross-section including the optical axis Ax is set to a substantially U-shape.

  As a result, as shown in FIGS. 3, 5 and 6, the additional reflector 34 does not greatly deviate the direction of the reflected light from the direction of the light directly incident on the upper reflection area of the reflector 24 from the light source 22 a. In addition, the reflected light from the additional reflector 34 is incident on a wide range of the upper reflection region located above the optical axis Ax on the reflection surface 24a of the reflector 24.

  At this time, the reflection surface 34a of the additional reflector 34 is composed of a plurality of diffuse reflection elements 34s formed so as to extend diagonally rearward from the optical axis in the plan view, whereby reflected light from the additional reflector 34 is reflected. Is made to enter the upper reflection region of the reflector 24 in a state where the light is diffused finely.

  FIG. 7 is a perspective view showing a light distribution pattern formed on a virtual vertical screen arranged at a position 25 m ahead of the lamp by light emitted forward from the vehicle headlamp 10.

  As shown in the figure, this light distribution pattern is a left light distribution low beam light distribution pattern PL, which has a horizontal cut-off line CL1 at its upper edge and a predetermined angle (for example, about 15 °) from the horizontal cut-off line CL1. The elbow point E, which is the intersection of both the cut-off lines CL1, CL2, is located at 0.5 to 0.6 ° of HV, which is the vanishing point in the front direction of the lamp. The position is set to a lower position. In the low beam light distribution pattern PL, a hot zone HZ which is a high luminous intensity region is formed so as to surround the elbow point E.

  The low beam light distribution pattern PL is formed as a combined light distribution pattern of the basic light distribution pattern P0 and the additional light distribution pattern Pa.

  The basic light distribution pattern P0 is a light distribution pattern that forms the basic shape of the low-beam light distribution pattern PL, and is formed by light from the light source 22a that is reflected by the reflector 24 and transmitted through the projection lens 28. Yes. The horizontal and oblique cut-off lines CL1 and CL2 are formed in the basic light distribution pattern P0 as a reverse projection image of the upper end edge 32a of the shade 32. In the basic light distribution pattern P0, a plurality of curves formed substantially concentrically with the contour curve are isoilluminance curves, and the light distribution pattern gradually increases from the outer periphery toward the hot zone HZ. It shows brightening.

  On the other hand, the additional light distribution pattern Pa is a light distribution pattern that is additionally formed to reinforce the brightness of the diffusion region of the basic light distribution pattern P0, and is sequentially reflected by the additional reflector 34 and the reflector 24 and projected. It is formed by the light from the light source 22 a that has passed through the lens 28. At this time, since the reflected light from the additional reflector 34 enters the upper reflection area of the reflector 24 as diffused light over a wide range, the additional light distribution pattern Pa has a large left-right diffusion angle and a substantially uniform luminous intensity distribution. It becomes a light pattern.

  As described in detail above, the vehicle headlamp 10 according to the present embodiment is configured as a projector-type vehicle headlamp that performs light irradiation for forming the low beam light distribution pattern PL. Since the light source bulb 22 is inserted and fixed to the reflector 24 from the side of the optical axis Ax extending in the vehicle front-rear direction, the front-rear length of the lamp can be shortened to make it compact.

  At that time, since the light source bulb 22 is inserted and fixed at a position away from the optical axis Ax, the side area of the optical axis in the reflecting surface 24a of the reflector 24 is effectively used for light distribution control. Can do. Then, a diffusion region of the low beam distribution pattern PL can be formed by the reflected light from the region on the side of the optical axis, and sufficient brightness can be secured in this diffusion region.

  Further, an additional reflector 34 for reflecting the light from the light source 22a toward the upper reflection area located above the optical axis Ax in the reflector 24 is provided at a position directly below the light source 22a. By forming the light distribution pattern Pa, the diffusion region of the low beam light distribution pattern PL can be further brightened.

  At this time, the additional reflector 34 is disposed at a position close to the light source 22a. However, since the light source 22a is disposed at a position separated downward from the optical axis Ax, the light incident on the reflector 24 from the light source 22a. In addition, the light reflected from the reflector 24 can be prevented from being shielded by the additional reflector 34. As a result, most of the downward emitted light from the light source 22a can be reflected by the additional reflector 34, so that the additional light distribution pattern Pa can be made sufficiently bright.

  As described above, according to the present embodiment, the brightness of the diffusion region of the low-beam light distribution pattern PL is sufficiently increased even when the side-insertion-type lamp configuration is employed in the projector-type vehicle headlamp. Can be secured.

  In particular, in the present embodiment, the reflecting surface of the additional reflector 34 is set to have a substantially W-shaped cross section along the vertical cross section orthogonal to the optical axis Ax, and a cross section along the vertical cross section including the optical axis Ax. Since the shape is set to be substantially U-shaped, the direction of the reflected light from the additional reflector 34 is prevented from greatly deviating from the direction of light directly incident on the upper reflection area of the reflector 24 from the light source 22a. Thus, the light can be incident over a wide range of the upper reflection region of the reflector 24. Then, since the additional light distribution pattern Pa can have a large right-and-left diffusion angle and a substantially uniform light intensity distribution, the light distribution pattern for low beam PL does not cause a large light distribution unevenness. The brightness of the diffusion region can be increased.

  Moreover, in the present embodiment, the reflection surface 34a of the additional reflector 34 is composed of a plurality of diffuse reflection elements 34s formed so as to extend obliquely rearward from the optical axis Ax in plan view. The reflected light can be incident on the upper reflection region of the reflector 24 in a state of being finely diffused. As a result, the luminous intensity distribution of the additional light distribution pattern Pa can be made more uniform, and the occurrence of uneven light distribution in the low beam light distribution pattern PL can be more effectively suppressed.

  In the present embodiment, since the discharge bulb is used as the light source bulb 22, the downward emitted light from the light source 22a becomes yellowish due to iodide accumulated in the lower region of the discharge vessel. As described above, by causing the reflected light from the additional reflector 34 to enter the upper reflection region of the reflector 24 in a finely diffused state, it is possible to effectively suppress the occurrence of color unevenness in the additional light distribution pattern Pa. can do. Thereby, it is possible to effectively suppress the occurrence of color unevenness even in the low-beam light distribution pattern PL.

  Since the light source 22a of the light source bulb 22 is configured as a line light source extending in the direction of the bulb center axis Ax1, the light beam having the highest luminous intensity in the direction orthogonal to the bulb center axis Ax1 is directly below the light source 22a. The incident light can be incident on the additional reflector 34 that is positioned, whereby the additional light distribution pattern Pa can be made brighter.

  The light source bulb 22 has a stay 22b extending substantially parallel to the bulb central axis Ax1, and the stay 22b is arranged around the bulb central axis Ax1 with respect to a position directly below the bulb central axis Ax1. Since it is inserted and fixed to the reflector 24 in a state rotated about the front side, the downward emitted light from the light source 22a can be incident on the additional reflector 34 without being blocked by the stay. The brightness of the diffusion region of the light pattern can be further increased.

  Similar effects can be obtained when the stay 22b is rotated backward instead of rotating the stay 22b in this manner.

  In the above-described embodiment, the light source bulb 22 is described as being inserted from the sideways direction with respect to the reflector 24. However, even if the insertion angle is slightly deviated from the sideways direction, the light source bulb 22 is up or down or front and back. If the deviation in direction is about 30 ° or less, substantially the same effect as the above embodiment can be obtained.

Side sectional view which shows the vehicle headlamp which concerns on one Embodiment of this invention The side view which shows the lamp unit of the said vehicle headlamp with the single item, Comprising: The figure which shows the optical path of the light reflected with the reflector It is a sectional side view which shows the said lamp unit as a single item, Comprising: The figure which shows the optical path of the light reflected with the additional reflector It is a plane sectional view showing the above-mentioned lamp unit by a single item, and is a diagram showing an optical path of light reflected by a reflector It is a plane sectional view showing the above-mentioned lamp unit by a single item, and is a diagram showing an optical path of light reflected by an additional reflector The front view which shows the said lamp unit separately, Comprising: The figure which shows the optical path of the light reflected with the additional reflector The figure which shows transparently the light distribution pattern formed on the virtual vertical screen arrange | positioned in the position of the lamp front 25m with the light irradiated ahead from the said vehicle headlamp

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle headlamp 12 Lamp body 14 Translucent cover 20 Lamp unit 22 Light source bulb 22a Light source 22b Stay 24 Reflector 24a Reflective surface 24b Valve insertion fixing part 24c Valve insertion hole 24d Aiming bracket 24e Support bracket part 26 Holder 28 Projection lens 32 Shade 32a Upper edge 34 Additional reflector 34a Reflecting surface 34s Diffuse reflecting element 50 Aiming mechanism Ax Optical axis Ax1 Valve central axis CL1 Horizontal cut-off line CL2 Oblique cut-off line E Elbow point F Rear focus HZ Hot zone PL Low beam light distribution pattern PO Basic Light distribution pattern Pa Additional light distribution pattern

Claims (3)

A projection lens disposed on the optical axis extending in the vehicle front-rear direction, a light source disposed behind the rear focal point of the projection lens, and light from the light source is reflected toward the optical axis toward the front A vehicle headlamp comprising a reflector to be
The light source is composed of a light emitting part of a light source bulb inserted and fixed to the reflector from the side of the optical axis at a position spaced downward from the optical axis,
An additional reflector that reflects light from the light source toward an upper reflection region located above the optical axis in the reflector is provided at a position directly below the light source .
The reflecting surface of the additional reflector has a substantially W-shaped cross-sectional shape along a vertical cross-section perpendicular to the optical axis, and a substantially U-shaped cross-sectional shape along the vertical cross-section including the optical axis. Has been
The reflective surface of the additional reflector, ing a plurality of diffuse reflection elements formed so as to extend to the left and right obliquely rearward from the optical axis in a plan view, a vehicle headlamp, characterized in that. It said light source bulb is a discharge bulb, claim 1 vehicle headlamp, wherein the. The discharge bulb has a stay extending substantially parallel to the bulb central axis of the discharge bulb, and the stay is rotated by a predetermined angle around the bulb central axis with respect to a position directly below the bulb central axis. The vehicle headlamp according to claim 2 , wherein the vehicle headlamp is inserted into and fixed to the reflector.

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