JP2006040785A - Vehicular headlamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow an appropriate light distribution pattern to be formed even when a movable shade is moved to any position, in a projector type vehicular headlamp having the movable shade. <P>SOLUTION: This vehicular headlamp is so structured that the movable shade 32 can be moved, by a shade driving device 36, between a first shade position where its upper edge 32a is positioned on an optical axis Ax at the rear-side focal point F of a projection lens 28 and a second shade position located below it. Therefore, a light distribution pattern for a low beam and a light distribution pattern for a high bean can selectively formed even if a single light source 22a is used. In addition, the vehicular headlamp is so structured that the light source 22a can be moved, by a light source driving device 38, between a first light source position located on the optical axis Ax and a second light source position located in front of the first light source position. Four kinds of light distribution patterns can be formed by combinations of the positions of the light source 22a with the positions of the movable shade 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a so-called projector-type vehicle headlamp, and particularly to a vehicle headlamp provided with a movable shade.

  In general, a projector-type vehicle headlamp has a projection lens disposed on an optical axis extending in the longitudinal direction of the vehicle, and a light source disposed behind the rear focal point. The reflector is configured to reflect near the optical axis. When a low beam light distribution pattern is formed by the projector-type vehicle headlamp, the reflector is provided with a shade arranged so that the upper edge is positioned near the optical axis near the rear focal point of the projection lens. A part of the reflected light from the light is shielded, and a predetermined cut-off line is formed at the upper end of the low beam light distribution pattern.

  In this case, in “Patent Document 1”, as the shade, the first shade position where the upper end edge is located near the optical axis in the vicinity of the rear focal point, and the position of the upper end edge are the positions at the first shade position. A projector-type vehicular headlamp having a movable shade configured to be movable between a second shade position located below the position is described.

  Further, in “Patent Document 2”, in the projector-type vehicle headlamp provided with the shade, the light source is arranged with respect to a first light source position located near the optical axis, and the first light source position. A device including a light source driving device that moves between a second light source position located on the left side, the right side, or the lower side is described.

JP 2002-56708 A JP 2002-42516 A

  In the vehicle headlamp described in the “Patent Document 1”, a high beam light distribution pattern can be formed by moving the movable shade to the second shade position. It can be used for both low beam and high beam.

  However, in the vehicle headlamp described in “Patent Document 1”, the low beam distribution pattern and the high beam distribution pattern are formed by the reflected light from the same reflection region of the reflector. If the shape of the reflective surface is suitable for the low-beam light distribution pattern, it is not always possible to obtain a suitable light distribution pattern for the high-beam light distribution pattern. Then, there is a problem that an appropriate light distribution pattern cannot always be obtained as the low beam light distribution pattern.

  On the other hand, if a lamp configuration including a movable light source as described in “Patent Document 2” is employed, the light intensity distribution of the low beam light distribution pattern can be changed by moving the light source. It becomes possible.

  However, the vehicle headlamp described in “Patent Document 2” has a problem that a high-beam light distribution pattern cannot be obtained because the shade is fixed. Further, as described in “Patent Document 2”, the light intensity distribution of the low beam light distribution pattern can be changed only by moving the light source in the direction orthogonal to the optical axis. There is a problem that it cannot be changed.

  The above problem is not only when switching between the light distribution pattern for the low beam and the light distribution pattern for the high beam, but also the light distribution pattern for the low beam and the intermediate light distribution pattern (that is, the light distribution pattern for the low beam and the light distribution pattern for the high beam). In the case of switching to an intermediate light distribution pattern between (1) and (2), the same problem may occur.

  The present invention has been made in view of such circumstances, and in a projector-type vehicle headlamp equipped with a movable shade, an appropriate light distribution pattern regardless of where the movable shade moves to any position. It is an object of the present invention to provide a vehicular headlamp that can form a lamp.

  According to the present invention, not only the shade but also the light source is movable, and these can be linked together, and the above object is achieved by devising the moving direction of the light source.

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 rearward of the rear focal point of the projection lens, and light from this light source is reflected toward the optical axis toward the front. A vehicle headlamp comprising: a reflector to be moved; and a movable shade configured to be able to shield a part of the reflected light from the reflector.
A light source driving device for moving the light source between a first light source position located in the vicinity of the optical axis and a second light source position located in front of the first light source position;
The movable shade includes a first shade position where an upper end edge of the movable shade is located in the vicinity of the optical axis in the vicinity of the rear focal point, and a position of the upper edge is lower than a position in the first shade position. A shade driving device that moves between the second shade position,
The light source driving device and the shade driving device are configured to be driven in conjunction with each other.

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

  As long as the “second light source position” is located in front of the first light source position, the specific position is not particularly limited. It is preferable to set the position about 3 mm forward, and it is more preferable to set the position about 1.5 to 2.5 mm forward with respect to the first light source position.

  As long as the “reflector” is configured to reflect light from the light source forward and toward the optical axis, the specific configuration such as the size and the shape of the reflecting surface is not particularly limited. Absent.

  The specific configuration such as the shape and size of the “movable shade” is not particularly limited. In addition, the “movable shade” is configured to shield a part of the reflected light from the reflector. At that time, the movable shade shields a part of the reflected light when in the first shade position. If it is configured, when it is in the second shade position, it may be configured to completely cancel the shielding of the reflected light, or may be configured to partially cancel the shielding of the reflected light. May be.

  The specific position of the “second shade position” is not particularly limited as long as it is located below the first shade position, but from the viewpoint of effectively releasing the shielding. The downward displacement amount is preferably set to 3 mm or more, and the downward displacement amount is more preferably set to 3.5 mm or more.

  The “light source driving device” is not particularly limited as long as the light source is configured to move the light source between the first light source position and the second light source position. For example, a solenoid or a pulse motor can be employed. Further, the movement mode of the light source by the driving of the “light source driving device” is not particularly limited, and for example, a movement method such as a rotation motion or a linear reciprocation motion can be employed.

  The above-mentioned “shade driving device” is not particularly limited as long as the movable shade is configured to move between the first shade position and the second shade position. For example, a solenoid or a pulse motor can be used. Further, the moving mode of the movable shade by the driving of the “shade driving device” is not particularly limited, and for example, a moving manner such as a rotational motion or a linear reciprocating motion can be employed.

  The “light source driving device” and the “shade driving device” may be configured to always be driven in conjunction with each other as long as they are configured to be driven in conjunction with each other. It may be configured to drive.

  As shown in the above configuration, the vehicular headlamp according to the present invention is configured as a projector-type vehicular headlamp provided with a movable shade. Between the first shade position located near the optical axis in the vicinity of the rear focal point of the projection lens and the second shade position where the position of the upper edge is located below the position at the first shade position. Since it can move, even with a single light source, a low beam light distribution pattern and a high beam light distribution pattern or an intermediate light distribution pattern can be selectively formed.

  Moreover, the vehicular headlamp according to the present invention has a light source whose first light source position is located near the optical axis by the light source driving device and a second light source position that is located forward of the first light source position. Since it is configured to be movable between the light source positions, four types of light distribution patterns can be obtained by combining the positions of the light sources and the movable shade.

  That is, when the light source is at the first light source position and the movable shade is at the first shade position, a part of the reflected light from the reflector is shielded by the movable shade, so that the upper edge of the movable shade is A first low-beam light distribution pattern having a cut-off line as a reverse image at the upper end can be obtained. From this state, if the movable shade moves to the second shade position, all or part of the shielding by the movable shade is released, so light irradiation is performed above the cutoff line of the first low beam light distribution pattern. Thus, the first high beam light distribution pattern or the intermediate light distribution pattern can be obtained.

  The intermediate light distribution pattern can be formed by setting the second shade position closer to the first shade position than when forming the high beam light distribution pattern. If the second shade position is set to a position relatively close to the first shade position, this intermediate light distribution pattern is cut off as if the cut-off line of the low beam light distribution pattern was translated upward. It can be set as the light distribution pattern which has.

  On the other hand, if the light source moves to the second light source position from the state where the light source is at the first light source position and the movable shade is at the first shade position, the rear side of the projection lens of the reflected light from the reflector The degree of light collection at the focal plane can be increased. Thus, as in the first low beam light distribution pattern, while maintaining a light distribution pattern shape having a cut-off line at the upper end portion, the overall diffusion angle is larger than that of the first low beam light distribution pattern. The second light distribution pattern for low beam having a small center and high central luminous intensity can be obtained.

  Further, if the light source is moved to the second light source position and the movable shade is moved to the second shade position from the state where the light source is at the first light source position and the movable shade is at the first shade position. The light irradiation is performed above the cut-off line of the first low beam light distribution pattern in a state in which the degree of condensing of the reflected light from the reflector on the rear focal plane of the projection lens is increased. As compared with the high beam light distribution pattern or the intermediate light distribution pattern, it is possible to obtain the second high beam light distribution pattern or the intermediate light distribution pattern having an overall small diffusion angle and a high central luminous intensity.

  If any one of these four types of light distribution patterns is appropriately selected according to the vehicle running condition, safety and comfort during night driving can be improved.

  That is, even if the light distribution pattern for the low beam is the same, the first low beam light distribution pattern that can irradiate the front of the vehicle widely when driving in an urban area or the like is selected, while distant visibility is selected when driving at a high speed. If the second low beam light distribution pattern excellent in the above is selected, the safety and comfort during night driving with the low beam can be improved.

  In addition, even if the same light distribution pattern for the high beam or the intermediate light distribution pattern is used, the first high beam light distribution pattern or the intermediate light distribution that can widely illuminate the front of the vehicle when traveling on a curved road in a mountainous area. If a second light distribution pattern or an intermediate light distribution pattern with excellent distance visibility is selected while a light pattern is selected while traveling at a high speed on a straight road, a high beam or an intermediate beam is selected. It is possible to improve safety and comfort when driving at night (that is, an intermediate beam between the low beam and the high beam).

  As described above, according to the present invention, in the projector-type vehicle headlamp provided with the movable shade, an appropriate light distribution pattern can be formed when the movable shade is moved to any position.

  As described above, the shape of the reflecting surface of the “reflector” is not particularly limited in the above configuration. However, the reflecting surface of the reflector is projected at a point near the first light source position as the first focal point and near the optical axis. If the configuration has a substantially elliptical vertical cross-sectional shape in which the second focal point is a point located in front of the rear focal point of the lens, the following operational effects can be obtained.

  That is, the vertical cross-sectional shape of the reflecting surface of the reflector is set to be substantially elliptical, and the second focal point is set in front of the rear focal point of the projection lens, whereby the second focal point is set to the rear focal point of the projection lens. As compared with the case where the position is set to 1, the degree of condensing of the reflected light from the reflector on the rear focal plane of the projection lens can be relaxed, whereby the first light distribution pattern for low beam and the first high beam can be reduced. The light distribution pattern for use or the intermediate light distribution pattern can be a light distribution pattern having a somewhat large diffusion angle. On the other hand, when the light source moves forward from the first focal point, the convergence position of the reflected light from the reflector moves from the second focal point to the rear side thereof, so that the second focal point is located forward of the rear focal point of the projection lens. By setting, it is possible to effectively increase the degree of condensing of the reflected light from the reflector on the rear focal plane of the projection lens when the light source moves to the second light source position. As a result, as compared with the first low-beam light distribution pattern and the first high-beam light distribution pattern or the intermediate light distribution pattern, the second low-beam distribution having a small diffusion angle and a high central luminous intensity as a whole. The light pattern and the second high beam light distribution pattern or the intermediate light distribution pattern can be reliably obtained.

  In the above configuration, if the second light source position is set below the first light source position, the following operational effects can be obtained.

  That is, when the second light source position is set forward and downward with respect to the first light source position, the second light source position is set in front of the same height as the first light source position. As compared with the above, the position where the reflected light from the reflector enters the rear focal plane of the projection lens can be displaced upward. As a result, the shielding amount of the reflected light from the reflector by the movable shade can be kept small, so that the light source luminous flux can be effectively used, thereby making the second low beam light distribution pattern brighter. be able to.

  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 10 according to an embodiment of the present invention.

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

  In the vehicular headlamp 10, when the aiming adjustment by the aiming mechanism 50 is completed, the optical axis Ax of the lamp unit 20 is a downward direction of about 0.5 to 0.6 ° with respect to the vehicle longitudinal direction. It is designed to extend.

  FIG. 2 is a side sectional view showing the lamp unit 20 as a single item, and FIG. 3 is a detailed view of the main part of 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 movable shade 32, and a bulb support base. 34, a shade driving device 36, and a light source driving device 38.

  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 the image on the rear 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 the light source 22a. The light source bulb 22 is inserted into the bulb insertion portion 34a of the bulb support base 34 and fixed by the wire spring 30. 24 is inserted into the rear top opening 24b from the rear side. The light source 22a of the light source bulb 22 is disposed on the rear side of the rear focal point F of the projection lens 28. When the light source 22a is at a first light source position to be described later, the optical axis Ax is along the optical axis Ax. It is arranged to extend.

  The reflector 24 is configured to reflect the light from the light source 22a forward and toward the optical axis Ax. The reflecting surface 24a of the reflector 24 has a cross-sectional shape including the optical axis Ax set to an elliptical shape with the center of the light source 22a on the optical axis Ax as the first focal point F1, and the eccentricity is horizontal from the vertical cross section. It is set to gradually increase toward the cross section. At this time, the second focal point F2 of the ellipse that forms a vertical section including the optical axis Ax is set to a point that is located slightly in front of the rear focal point F of the projection lens 28. As a result, the reflector 24 substantially converges the light from the light source 22a reflected by the reflecting surface 24a to the second focal point F2 in the vertical cross section, and moves the converging position considerably forward in the horizontal cross section. It is designed to move.

  The holder 26 is formed so as to extend in a substantially cylindrical shape from the opening at the front end of the reflector 24 toward the front, and the reflector 24 is fixedly supported at the rear end, and the projection lens 28 is fixedly supported at the front end. ing. The holder 26 has a lower region cut out, and a plurality of aiming brackets 26 a for connecting the lamp unit 20 to the aiming mechanism 50 are formed at the peripheral edge of the rear end.

  The movable shade 32 is provided so as to be positioned in a substantially lower half portion in the internal space of the holder 26 and is rotatably supported by the holder 26 via a rotation pin 44 extending in the left-right direction. The movable shade 32 is rotated by a predetermined angle from the first shade position indicated by a solid line in FIGS. 2 and 3 and downward from the first shade position, and is indicated by a two-dot chain line in FIGS. 2 shade positions can be taken.

  The upper end edge 32a of the movable shade 32 is formed in a step difference on the left and right, and extends in a substantially arc shape in the horizontal direction. When the movable shade 32 is in the first shade position, the upper edge 32a is disposed so as to pass through the rear focal point F of the projection lens 28 and extend along the rear focal plane. When moved to the second shade position, it is arranged obliquely downward and rearward than when it is in the first shade position. And in this 2nd shade position, the upper end edge 32a of the movable shade 32 is located about 4 mm below from the time of being in a 1st shade position.

  A fixed shade 40 for preventing stray light reflected by the reflector 24 from entering the projection lens 28 is integrally formed with the holder 26 in front of the movable shade 32. The fixed shade 40 includes a positioning contact portion 40a for contacting the movable shade 32 when the movable shade 32 moves to the first shade position and positioning the movable shade 32 at the first shade position, and a movable shade 32. A positioning contact portion 40b is formed for contacting the movable shade 32 when the shade 32 moves to the second shade position and positioning the movable shade 32 at the second shade position.

  The shade driving device 36 is constituted by a solenoid having a plunger 36 a extending forward, and is fixed to a device mounting portion 24 d formed on the lower surface of the bottom wall 24 c of the reflector 24. The plunger 36a of the shade driving device 36 is engaged with a stay 32b formed so as to protrude downward from the movable shade 32 at the tip end portion thereof, thereby reciprocating the plunger 36a in the front-rear direction. It is transmitted as 32 rotational movements. The shade driving device 36 is driven when a beam changeover switch (not shown) is operated to move the plunger 36a in the front-rear direction, thereby moving the movable shade 32 to the first and second shade positions. Move between them.

  The valve support base 34 is provided in the vicinity of the rear of the rear top opening 24b of the reflector 24, and is supported by the reflector 24 at the lower end thereof so as to be rotatable. That is, the valve support base 34 is connected to a tip end portion of a bracket 24e extending rearward from the device mounting portion 24d of the reflector 24 through a pivot pin 42 extending in the left-right direction in a bracket 34b formed at a lower end portion thereof. It can be turned around the turning pin 42. The rotation pin 42 is disposed at a position about 10 to 30 ° behind the light source 22a vertically below.

  The light source driving device 38 is composed of a solenoid having a plunger 38 a extending rearward, and is fixed to a device mounting portion 24 f formed on the upper portion of the reflector 24. The plunger 38 a of the light source driving device 38 is engaged with the upper end portion of the bulb support base 34 at the tip portion thereof, whereby the reciprocating motion of the plunger 38 a in the front-rear direction is transmitted as the rotational motion of the bulb support base 34. It is supposed to be. The light source driving device 38 is driven by a drive signal from a drive control means (not shown) to move the plunger 38a in the front-rear direction, thereby causing the light source 22a to move to the first focus F1 whose center is located at the first focus F1. The first light source position is moved between the first light source position and the second light source position whose center is located at a point A slightly below the front of the first focal point F1. The specific position of this point A is set to a position approximately 2 mm forward and approximately 0.5 mm below the first focal point F1.

  A positioning contact for positioning the light source 22a at the first light source position is brought into contact with the bracket 24e of the reflector 24 when the light source 22a moves to the first light source position. A portion 34c is formed. In addition, the upper part of the rear top opening 24b of the reflector 24 is brought into contact with the upper end of the bulb insertion portion 34a of the bulb support base 34 when the light source 22a moves to the second light source position. A positioning contact portion 24g for positioning at the two light source positions is formed.

  When the light source 22a is at the first light source position, the center thereof is located at the first focal point F1, so that the light from the center of the light source 22a reflected by the reflector 24 is indicated by a solid line in FIGS. Furthermore, it intersects the optical axis Ax at the second focal point F2 of the ellipse. On the other hand, when the light source 22a is at the second light source position, the center of the light source 22a is located at a point A slightly in front of the first focal point F1, so that the light from the center of the light source 22a reflected by the reflector 24 is 2 and 3, it intersects with the optical axis Ax on the rear side of the second focal point F2, as indicated by a two-dot chain line.

  At this time, since the second focal point F2 is located in front of the rear focal point F of the projection lens 28, the degree of condensing of the reflected light from the reflector 24 on the rear focal plane of the projection lens 28 is determined by the light source 22a. Is higher at the second light source position than at the first light source position. In addition, since the second light source position is not only located in front of the first light source position but also slightly lower, the condensing position on the rear focal plane of the projection lens 28. Is slightly displaced with respect to the optical axis Ax.

  4 to 7 are side sectional views of the lamp unit 20 showing the difference in the optical path depending on the combination of the position of the light source 22a and the position of the movable shade 32. FIG.

  FIG. 4 is a diagram illustrating an optical path when the light source 22a is at the first light source position and the movable shade 32 is at the first shade position, and FIG. 5 is a diagram illustrating the light source 22a at the second light source position. FIG. 6 is a diagram showing an optical path when the movable shade 32 is at the first shade position. FIG. 6 shows an optical path when the light source 22a is at the first light source position and the movable shade 32 is at the second shade position. FIG. 7 is a diagram showing an optical path when the light source 22a is at the second light source position and the movable shade 32 is at the second shade position.

  As shown in FIGS. 4 and 5, when the movable shade 32 is in the first shade position, the reflected light from the reflector 24 is the same regardless of whether the light source 22 a is in the first or second light source position. A part is shielded by the movable shade 32, and the rest enters the projection lens 28. On the other hand, as shown in FIGS. 6 and 7, when the movable shade 32 is at the second shade position, the reflected light from the reflector 24 is reflected regardless of whether the light source 22 a is at the first or second light source position. The substantially entire amount is incident on the projection lens 28 without being shielded by the movable shade 32.

  Further, as shown in these figures, in the case where the movable shade 32 is in either the first or second shade position, the light source 22a is in the second light source position than when the light source 22a is in the first light source position. In some cases, the degree of concentration of the reflected light from the reflector 24 on the rear focal plane of the projection lens 28 is higher.

  FIGS. 8 and 9 are perspective views showing a light distribution pattern formed on a virtual vertical screen arranged at a position 25 m ahead of the lamp by light irradiated forward from the vehicle headlamp 10.

  A light distribution pattern PL1 shown in FIG. 8A is a low beam light distribution pattern formed when the light source 22a is at the first light source position and the movable shade 32 is at the first shade position. The light distribution pattern PL2 shown in (b) is a low-beam light distribution pattern formed when the light source 22a is at the second light source position and the movable shade 32 is at the first shade position.

  A light distribution pattern PH1 shown in FIG. 9A is a high beam light distribution pattern formed when the light source 22a is at the first light source position and the movable shade 32 is at the second shade position. A light distribution pattern PH2 shown in FIG. 6B is a high beam light distribution pattern formed when the light source 22a is at the second light source position and the movable shade 32 is at the second shade position.

  A low beam light distribution pattern PL1 shown in FIG. 8A is a left light distribution light beam distribution pattern, and has upper and lower cut-off lines CL1 and CL2 at its upper edge. The cut-off lines CL1 and CL2 extend in the horizontal direction at the left and right steps with the VV line passing through the HV, which is a vanishing point in the front direction of the lamp, in the vertical direction, and are on the right side of the VV line. The opposite lane side portion is formed as a lower cut-off line CL1, and the own lane side portion on the left side of the VV line is formed as an upper cut-off line CL2 that rises from the lower cut-off line CL1 through an inclined portion. Is formed. In this low beam light distribution pattern PL1, the position of the elbow point E that is the intersection of the lower cut-off line CL1 and the VV line is set to a position about 0.5 to 0.6 ° below HV. A hot zone HZL, which is a high luminous intensity region, is formed so as to surround the elbow point E slightly to the left.

  The low-beam light distribution pattern PL1 is an image of the light source 22a formed on the rear focal plane of the projection lens 28 by the light from the light source 22a reflected by the reflection surface 24a of the reflector 24. It is formed by projecting as a reverse projection image on the screen, and the cut-off lines CL1 and CL2 are formed as a reverse projection image of the upper edge 32a of the movable shade 32.

  The low-beam light distribution pattern PL2 shown in FIG. 8B is exactly the same as the low-beam light distribution pattern PL1 with respect to the cut-off lines CL1 and CL2, but the overall diffusion angle is the low-beam light distribution pattern. The hot zone HZL is slightly smaller than that in the case of PL1 and brighter than that in the case of the low beam light distribution pattern PL1. This is because the concentration of the reflected light from the reflector 24 on the rear focal plane of the projection lens 28 is higher when the light source 22a is at the second light source position than when the light source 22a is at the first light source position. It is due to what has become.

  The high beam light distribution pattern PH1 shown in FIG. 9A has a shape in which the low beam light distribution pattern PL1 is expanded to the region above the cut-off lines CL1 and CL2, and is centered on HV. A hot zone HZH is formed. This is because the shielding of the reflected light from the reflector 24 by the movable shade 32 is released by the movement of the movable shade 32 from the first shade position to the second shade position.

  The high beam light distribution pattern PH2 shown in FIG. 9B has a shape obtained by enlarging the low beam light distribution pattern PL2 to a region above the cut-off lines CL1 and CL2. The overall diffusion angle of the high beam light distribution pattern PH2 is slightly smaller than that of the high beam light distribution pattern PH1, and the hot zone HZH is brighter than that of the high beam light distribution pattern PH1. .

  As described in detail above, the vehicular headlamp 10 according to the present embodiment is configured as a projector-type lamp unit in which the lamp unit 20 includes the movable shade 32. The movable shade 32 is a shade. By the driving device 36, the first shade position where the upper end edge 32a is located on the optical axis Ax at the rear focal point F of the projection lens 28, and the position of the upper end edge 32a are lower than the position at the first shade position. Since it is configured to be movable between the second shade position, the low-beam light distribution pattern PL1, PL2 and the high-beam light distribution pattern PH1, PH2 can be selectively formed.

  Moreover, in the vehicle headlamp 10 according to the present embodiment, the light source 22a is moved forward of the first light source position by the light source driving device 38 on the optical axis Ax and the first light source position. Since it is configured to move between the second light source position, four types of light distribution patterns can be formed by combining the position of the light source 22a and the position of the movable shade 32.

  That is, when the light source 22a is at the first light source position and the movable shade 32 is at the first shade position, a part of the reflected light from the reflector 24 is shielded by the movable shade 32. Thus, it is possible to obtain a low beam light distribution pattern PL1 having cut-off lines CL1 and CL2 as inverted images of the upper end edge 32a of 32 at the upper end. From this state, if the movable shade 32 moves to the second shade position, the shielding by the movable shade 32 is released, so that light irradiation is performed above the cut-off lines CL1 and CL2, thereby causing the high beam. A light distribution pattern PH1 can be obtained.

  On the other hand, if the light source 22a is moved to the second light source position from the state where the light source 22a is at the first light source position and the movable shade 32 is at the first shade position, the reflected light from the reflector 24 is projected. The degree of light collection at the rear focal plane of the lens 28 can be increased. As a result, while maintaining the light distribution pattern shape having the cut-off lines CL1 and CL2 at the upper end portion as in the low beam light distribution pattern PL1, the overall diffusion angle is larger than that of the low beam light distribution pattern PL1. A low beam light distribution pattern PL2 having a small central luminous intensity can be obtained.

  Further, the light source 22a is moved to the second light source position from the state where the light source 22a is at the first light source position and the movable shade 32 is at the first shade position, and the movable shade 32 is moved to the second shade position. , The light irradiation is performed above the cutoff lines CL1 and CL2 in a state in which the degree of condensing of the reflected light from the reflector 24 on the rear focal plane of the projection lens 28 is increased. It is possible to obtain a high beam light distribution pattern PH2 having a small diffusion angle and a high central luminous intensity as compared with the pattern PH1.

  Then, if any one of these four types of light distribution patterns PL1, PL2, PH1, and PH2 is appropriately selected according to the vehicle running condition, safety and comfort during night driving can be improved. it can.

  That is, even if the light distribution pattern for the same low beam is selected, the low beam light distribution pattern PL1 that can irradiate a wide range of the front of the vehicle when traveling in an urban area is selected, while the distance visibility is excellent when traveling at a high speed. If the low beam light distribution pattern PL2 is selected, safety and comfort during night driving with the low beam can be improved.

  Further, even when the light distribution pattern for the same high beam is used, a high beam light distribution pattern PH1 that can irradiate a wide range of the front of the vehicle is selected when traveling on a curved road in a mountainous area, while at a high speed traveling on a straight road. For example, if the light distribution pattern PH2 for high beam excellent in distance visibility is selected, safety and comfort during night driving with a high beam can be improved.

  At this time, switching between the low beam light distribution patterns PL1 and PL2 and the high beam light distribution patterns PH1 and PH2 is performed by driving the shade driving device 36 by operating a beam changeover switch (not shown). Switching between the pattern PL1 and the low-beam light distribution pattern PL2 and switching between the high-beam light distribution pattern PH1 and the high-beam light distribution pattern PH2 are performed by driving the light source driving device 38 by a drive signal from a drive control means (not shown). Since this drive control means is operated automatically by manual operation or in accordance with the vehicle running condition, an optimal light distribution pattern can be selected.

  Thus, according to the present embodiment, in the projector-type vehicle headlamp 10 including the movable shade 32, an appropriate light distribution pattern can be formed when the movable shade 32 moves to any position. it can.

  At that time, in the vehicle headlamp 10 according to the present embodiment, the reflecting surface 24a of the reflector 24 has the first light source position as the first focus F1 and is ahead of the rear focus F on the optical axis Ax. Since it has an elliptical vertical cross-sectional shape with the second focal point F2 as the point located at, the following operational effects can be obtained.

  That is, the vertical cross-sectional shape of the reflecting surface 24a of the reflector 24 is set to be elliptical, and the second focal point F2 is set in front of the rear focal point F of the projection lens 28, thereby projecting the second focal point F2. Compared with the case where the position is set to the rear focal point F of the lens 28, the degree of condensing of the reflected light from the reflector 24 on the rear focal plane of the projection lens 28 can be relaxed, and thereby the light distribution for the low beam. The pattern PL1 and the high beam light distribution pattern PH1 can be light distribution patterns having a somewhat large diffusion angle. On the other hand, when the light source 22a moves forward from the first focal point F1, the convergence position of the reflected light from the reflector 24 moves from the second focal point F2 to the rear side thereof, so that the second focal point F2 is moved to the rear side of the projection lens 28. By setting the position in front of the focal point F, the degree of concentration of the reflected light from the reflector 24 on the rear focal plane of the projection lens 28 when the light source 22a moves to the second light source position is effective. Can be enhanced. As a result, the low-beam light distribution pattern PL2 and the high-beam light distribution pattern PH2 that have a small diffusion angle and a high central luminous intensity as compared with the low-beam light distribution pattern PL1 and the high-beam light distribution pattern PH1 are ensured. Obtainable.

  Further, in the vehicle headlamp 10 according to the present embodiment, the second light source position is set forward and downward with respect to the first light source position, so the second light source position is the first light source position. Compared with the case where the position is set in front of the light source at the same height, the position where the reflected light from the reflector 24 enters the rear focal plane of the projection lens 28 can be displaced upward. As a result, the amount of light reflected from the reflector 24 by the movable shade 32 can be reduced, so that the light source luminous flux can be effectively used, thereby making the low beam light distribution pattern PL2 brighter. be able to.

  Next, a modification of the above embodiment will be described.

  FIG. 10 is a view similar to FIG. 2 showing the lamp unit 120 according to this modification. As shown in the figure, the lamp unit 120 has the same basic configuration as the lamp unit 20 according to the above embodiment, but the configuration of the shade driving device 136 is different from that in the above embodiment.

  That is, the shade drive device 136 of this modification is similar to the shade drive device 36 of the above embodiment in that it is configured by a solenoid having a plunger 136a extending forward, but the plunger 136a moves forward. The amount is set to a smaller value than in the case of the shade driving device 36 of the above embodiment. And thereby, the 2nd shade position of the movable shade 32 when this plunger 136a moves ahead is set to the position nearer the 1st shade position than the case of the said embodiment. Specifically, the second shade position in the present modification is set to be about 0.3 to 0.4 mm below the first shade position. The shade driving device 136 is driven by operating a beam changeover switch (not shown) as in the shade driving device 36 of the above embodiment.

  FIG. 11 is a perspective view of a light distribution pattern formed on a virtual vertical screen disposed at a position 25 m ahead of the lamp by light irradiated forward from a vehicle headlamp including the lamp unit 120 according to the present modification. FIG.

  A light distribution pattern PM1 shown in FIG. 5A is an intermediate light distribution pattern formed when the light source 22a is at the first light source position and the movable shade 32 is at the second shade position. The light distribution pattern PM2 shown in (b) is an intermediate light distribution pattern formed when the light source 22a is at the second light source position and the movable shade 32 is at the second shade position.

  The light source 22a is at the first light source position and the low beam distribution pattern formed when the movable shade 32 is at the first shade position and the light source 22a are at the second light source position, and the movable shade 32 is The low beam light distribution pattern formed when in the first shade position is exactly the same as in the above embodiment.

  The intermediate light distribution pattern PM1 shown in FIG. 11A has a shape in which the low beam light distribution pattern PL1 is slightly enlarged upward.

  That is, the intermediate light distribution pattern PM1 has cut-off lines CL3 and CL4 at the upper end, and a hot zone HZM is formed so as to surround the elbow point E slightly to the left. The cut-off lines CL3 and CL4 of the intermediate light distribution pattern PM1 are slightly above (specifically, about 0.34 °) above the cut-off lines CL1 and CL2 of the low-beam light distribution pattern PL1. Further, the hot zone HZM of the intermediate light distribution pattern PM1 has a shape in which the hot zone HZL of the low beam light distribution pattern PL1 is expanded upward to the positions of the cut-off lines CL3 and CL4.

  In the intermediate light distribution pattern PM2 shown in FIG. 11B, the positions of the cut-off lines CL3 and CL4 are exactly the same as those of the intermediate light distribution pattern PM1, but the overall diffusion angle is the intermediate light distribution pattern. The hot zone HZM is slightly smaller than that of the pattern PM1 and brighter than that of the intermediate light distribution pattern PM1. This is because the concentration of the reflected light from the reflector 24 on the rear focal plane of the projection lens 28 is higher when the light source 22a is at the second light source position than when the light source 22a is at the first light source position. It is due to what has become.

  When the lamp unit 120 of this modification is adopted, the movable shade 32 is moved between the first and second shade positions, so that the low beam distribution is achieved even though the light source 22a is single. The light patterns PL1 and PL2 and the intermediate light distribution patterns PM1 and PM2 can be selectively formed.

  That is, when the light source 22a is at the first light source position and the movable shade 32 is at the first shade position, the low beam light distribution pattern PL1 is obtained. From this state, the movable shade 32 is moved to the second shade. If moved to the position, the shielding by the movable shade 32 is somewhat relaxed, so that it is possible to obtain an intermediate light distribution pattern PM1 suitable for high speed traveling and mountainous traveling.

  In the intermediate light distribution pattern PM1, the hot zone HZM expands upward with respect to the hot zone HZL of the low beam light distribution pattern PL1, so that the visibility of a long-distance region on the road surface in front of the vehicle can be improved. However, at this time, the shield by the movable shade 32 is not completely released, but the cut-off lines CL3 and CL4 are left, so that a large glare can be prevented from being given to an oncoming vehicle driver or the like.

  On the other hand, when the light source 22a is at the second light source position and the movable shade 32 is at the first shade position, the overall diffusion angle is small and the central luminous intensity is high compared to the low beam light distribution pattern PL1. Although the low beam light distribution pattern PL2 is obtained, if the movable shade 32 is moved to the second shade position from this state, the degree of condensing of the reflected light from the reflector 24 on the rear focal plane of the projection lens 28 is increased. In this state, the shielding by the shade 32 is somewhat relaxed, so that it is possible to obtain an intermediate light distribution pattern PM2 having a small diffusion angle and a high central luminous intensity as compared with the intermediate light distribution pattern PM1. This can be made more suitable for high speed running.

  Then, if any one of these four kinds of light distribution patterns PL1, PL2, PM1, and PM2 is appropriately selected according to the vehicle running condition, safety and comfort during night driving can be improved. it can.

  In the above-described embodiment and its modifications, the lamp units 20 and 120 are configured to form the left-beam distribution pattern for the low beam as the low-beam distribution patterns PL1 and PL2. Even when configured to form a light distribution pattern for low beam distribution, it is possible to obtain the same operational effects by adopting the same configuration as that of the above-described embodiment and its modification.

Side sectional view which shows the vehicle headlamp which concerns on one Embodiment of this invention Side sectional view which shows the lamp unit of the vehicle headlamp as a single item Detailed view of the main part of FIG. Side sectional view showing an optical path when the light source is in the first position and the movable shade is in the second position in the embodiment. Side sectional view showing an optical path when the light source is in the second position and the movable shade is in the first position in the embodiment. Side sectional view showing an optical path when the light source is in the first position and the movable shade is in the second position in the embodiment. Side sectional view showing an optical path when the light source is in the second position and the movable shade is in the second position in the embodiment. It is a figure which shows in perspective the low beam 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, ) Is a diagram when the light source is at the first light source position and the movable shade is at the first shade position, and FIG. 5B is a diagram showing the light source at the second light source position and the movable shade is at the first shade position. Figure when there is FIG. 5 is a perspective view showing a high beam light distribution pattern formed on the virtual vertical screen by light irradiated forward from the vehicle headlamp, in which FIG. The figure when the movable shade is at the second shade position at the light source position, and FIG. 6B is the figure when the light source is at the second light source position and the movable shade is at the second shade position. The figure similar to FIG. 2 which shows the lamp unit which concerns on the modification of the said embodiment. FIG. 7 is a diagram transparently showing an intermediate light distribution pattern formed on the virtual vertical screen by light irradiated forward from a vehicle headlamp including the lamp unit according to the modified example. FIG. 5A is a view when the light source is at the first light source position and the movable shade is at the second shade position, and FIG. 5B is a view when the light source is at the second light source position and the movable shade is the second shade. Figure when in position

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle headlamp 12 Lamp body 14 Translucent cover 20, 120 Lamp unit 22 Light source bulb 22a Light source 24 Reflector 24a Reflective surface 24b Rear top opening 24c Bottom wall 24d, 24f Device mounting part 24e, 34b Bracket 24g, 34c, 40a, 40b Positioning contact portion 26 Holder 26a Aiming bracket 28 Projection lens 30 Wire spring 32 Movable shade 32a Upper edge 32b Stay 34 Valve support base 34a Valve insertion portion 36, 136 Shade drive device 36a, 38a, 136a Plunger 38 Light source Drive unit 40 Fixed shade 42, 44 Rotating pin 50 Aiming mechanism A point Ax Optical axis CL1, CL3 Lower cut-off line CL2, CL4 Upper cut-off line E Elbow point F Rear focus F1 First focus F2 second focus HZH, HZL, HZM hot zone PH1, PH2 light distribution pattern PL1 for high beam, for PL2 low beam light distribution pattern PM1, PM2 intermediate light distribution pattern

Claims (3)

A projection lens disposed on the optical axis extending in the vehicle front-rear direction, a light source disposed rearward of the rear focal point of the projection lens, and light from this light source is reflected toward the optical axis toward the front. A vehicle headlamp comprising: a reflector to be moved; and a movable shade configured to be able to shield a part of the reflected light from the reflector.
A light source driving device for moving the light source between a first light source position located in the vicinity of the optical axis and a second light source position located in front of the first light source position;
The movable shade includes a first shade position where an upper end edge of the movable shade is located in the vicinity of the optical axis in the vicinity of the rear focal point, and a position of the upper edge is lower than a position in the first shade position. A shade driving device that moves between the second shade position,
The vehicle headlamp, wherein the light source driving device and the shade driving device are configured to be able to be driven in conjunction with each other.   A substantially elliptical vertical shape in which the reflecting surface of the reflector has a point near the first light source position as a first focal point and a point located in front of the rear focal point near the optical axis as a second focal point. The vehicle headlamp according to claim 1, wherein the vehicle headlamp has a cross-sectional shape.   3. The vehicle headlamp according to claim 1, wherein the second light source position is set below the first light source position.

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