JP2011175920A - Headlight for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a headlight for a vehicle improved in forward visibility of one's own vehicle without dazzling an oncoming vehicle and a preceding vehicle by changing light distribution characteristics of the one's own vehicle in response to a state of a vehicle travelling in front of the one's own vehicle, and capable of obtaining a light distribution pattern having excellent cut-off lines. <P>SOLUTION: A shade mechanism 15 includes: a first shade 20 having an upper edge 21, which forms a whole horizontal region of a light distribution generating part for generating a light distribution pattern for a low beam and which is arranged at a shut-off position positioning near a rear focus point F of a projection lens 8, and having a light transmitting part opened downward except, at least, the upper edge 21; a plate-like second shade 23 capable of opening/closing the light transmitting part; and an actuator 30 for moving the second shade 23 to a closing position, in which the light transmitting part is closed, and an opening position, in which the light transmitting part is opened. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicular headlamp, and more particularly to a projector-type vehicular headlamp having a variable light distribution function capable of changing the light distribution of the headlamp in accordance with the traveling state of the vehicle.

  Conventionally, light from a light source bulb arranged on an optical axis extending in the longitudinal direction of the vehicle is condensed and reflected by the reflector toward the front of the optical axis, and this reflected light is provided on the front of the reflector. There is known a vehicular headlamp that includes a projector-type lamp unit that is configured to irradiate through a lamp.

When such a projector-type lamp unit is used, a shade capable of shielding a part of the reflected light from the reflector is provided between the projection lens and the reflector, for example, a required light distribution such as a passing light distribution pattern. By blocking unnecessary portions according to the pattern, a cut-off line can be formed at the upper end of the desired light distribution pattern.
However, in a configuration in which a single shade is fixed, the light distribution pattern that can be formed is single, for example, the upper end edge of the shade forms a light distribution generation unit for generating a light distribution pattern (low beam light distribution pattern). When this shape is set, the lamp unit can be used only for the passing beam and cannot be used for switching with the traveling beam (high beam light distribution pattern).

  Therefore, the shade is a movable shade that can be moved between the low beam position and the traveling beam position, and when it is set to the low beam position, its upper edge is positioned at the rear focal point of the projection lens, and when it is set to the traveling beam position, its upper edge. There has been proposed a vehicular headlamp that can obtain an optimum light distribution characteristic for both a passing beam and a traveling beam by appropriately deviating the edge from the rear focus of the projection lens.

  By the way, in a normal vehicle headlamp, the light distribution characteristic of the passing beam is set to a light distribution characteristic that irradiates only the front region limited as much as possible so as not to dazzle the oncoming vehicle and the preceding vehicle. For this reason, switching to the passing beam when there is a forward vehicle without distinguishing between the oncoming vehicle and the preceding vehicle, for example, even if there is only a preceding vehicle ahead of the host vehicle, the passing beam will also take into account the dazzling of the oncoming vehicle. It will be switched. As a result, there is a problem that the irradiation area in front of the own vehicle is restricted more than necessary, and the visibility of the driver is lowered.

Therefore, for example, Patent Document 1 describes a vehicle lamp (vehicle headlamp) including a shade that is divided into a left divided shade and a right divided shade at a position deviated in the left-right direction with respect to the lamp optical axis. Has been.
The left divided shade and the right divided shade are independently tilted by individual actuators, so that the left divided shade and the right divided shade can be changed independently.
Therefore, by changing the light distribution characteristics of the lamp according to the difference between the oncoming vehicle and the preceding vehicle, or the difference between the own vehicle, the front visibility of the own vehicle is improved without dazzling the oncoming vehicle and the preceding vehicle. be able to.

JP 2009-211193 A

  By the way, in the configuration of the vehicle lamp disclosed in Patent Document 1, the left divided shade and the right divided shade are separated because the shade divided into the left divided shade and the right divided shade is independently tilted. There will be a gap between the two. Therefore, in order to close the gap, the dividing edges are inclined surfaces inclined in the plate thickness direction, and the inclined surfaces are configured to overlap each other in the optical axis direction. It was necessary to prevent light leakage by providing an additional member for wrapping the light.

However, when an additional member that wraps the gap is provided, a color change due to a change in the thickness of the shade occurs on the cut-off line of the passing light distribution pattern irradiated forward.
In addition, if there is a step between the assembled left split shade and right split shade (difference in the height of the upper edge), a light distribution step is also generated on the cut-off line of the passing light distribution pattern irradiated forward. Causes a great sense of discomfort. Therefore, in order to eliminate such a light distribution step, it is necessary to reduce the component tolerance and increase the assembly accuracy, and there is a problem that a great number of man-hours and costs are generated.

  Accordingly, an object of the present invention is to solve the above-mentioned problems, and by changing the light distribution characteristics of the own vehicle according to the situation of the vehicle existing ahead, the oncoming vehicle and the preceding vehicle are not dazzled. An object of the present invention is to provide a vehicular headlamp capable of improving forward visibility and obtaining a good light distribution pattern of a cut-off line.

An object of the present invention is to provide a projection lens disposed on an optical axis extending in the vehicle front-rear direction in a lamp chamber formed by a lamp body and a cover, a light source disposed on the rear side of the projection lens, and the light source. A reflector that reflects the light from the front toward the optical axis, a part of the reflected light from the reflector disposed between the projection lens and the light source, and a part of the direct light from the light source A vehicular headlamp comprising a shade mechanism that shields light and forms a cut-off line of a light distribution pattern,
The shade mechanism is
An upper end edge that forms the entire horizontal region of the light distribution generation unit for generating the low beam light distribution pattern is disposed at a shielding position located in the vicinity of the rear focal point of the projection lens, and light is emitted at least below the upper end edge. A plate-like first shade having a transparent portion opened;
A plate-like second shade capable of opening and closing the light transmission part;
An actuator for moving the second shade to a closed position for closing the light transmitting portion and an open position for opening the light transmitting portion;
It is achieved by a vehicle headlamp characterized by comprising:

According to the vehicle headlamp configured as described above, when the actuator moves the second shade to the open position, only the light transmitting portion of the first shade reduces the shielding amount, and the other portions remain in the shielding position. . Therefore, the shade mechanism includes a light distribution pattern for low beam in which the light transmission portion of the first shade is closed to the second shade, and a light distribution pattern in which the light transmission portion is opened and only this portion reduces the shielding amount (for example, , One high beam light distribution pattern) can be switched by an actuator.
At this time, since the entire horizontal region of the light distribution generation unit for generating the light distribution pattern for the low beam is formed by the upper edge of the first shade, the shade is divided into the first shade and the second shade. Nevertheless, there is no light leakage, color change, or light distribution step due to division in the cut-off line of the light distribution pattern for low beam irradiated forward.

  In the vehicle headlamp configured as described above, it is desirable that the first shade can be moved to a shielding relaxation position that reduces a shielding amount with respect to the reflected light from the reflector rather than the shielding position.

  According to the vehicle headlamp having such a configuration, the shade mechanism can reduce the shielding amount of the first shade and the second shade by allowing the first shade to move to the shielding relaxation position. For example, it is possible to switch to a high beam light distribution pattern.

  Moreover, in the vehicle headlamp having the above-described configuration, it is preferable that a first reflection surface that reflects a part of light from the rear toward the front is provided at an opening edge of the light transmission portion of the first shade. .

  According to the vehicle headlamp having such a configuration, a part of the light blocked by the upper end edge of the first shade is reflected forward by the first reflecting surface provided at the opening edge, so that the light transmission portion Only light can be mitigated in the light distribution pattern that reduces the amount of shielding.

  In the vehicle headlamp configured as described above, a second reflecting surface that reflects a part of direct light from the light source toward the first reflecting surface is disposed between the reflector and the first shade. It is desirable that

  According to the vehicle headlamp having such a configuration, the second reflecting surface reflects a part of the unused direct light toward the first reflecting surface, so that the first reflecting provided at the opening edge is provided. By increasing the amount of light reflected by the surface toward the front, it is possible to prevent light leakage due to the reflected light of the reflector being blocked by the upper edge of the first shade.

  According to the vehicle headlamp of the present invention described above, by changing the light distribution characteristics of the vehicle according to the situation of the vehicle existing ahead, the vehicle's headlamp can be used without dazzling the oncoming vehicle and the preceding vehicle. While improving forward visibility, it is possible to obtain a light distribution pattern with a good cut-off line.

It is a schematic longitudinal cross-sectional view of the vehicle headlamp which concerns on one Embodiment of this invention. It is sectional drawing which follows the II-II line of the lamp unit in the vehicle headlamp of FIG. It is a back side principal part perspective view of the shade mechanism shown in FIG. It is a front side principal part perspective view of the shade mechanism shown in FIG. FIG. 5 is a front perspective view of a main part of the shade mechanism shown in FIG. It is a principal part enlarged view which shows the one-high beam use state of the shade mechanism shown in FIG.

Hereinafter, a vehicle headlamp according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
The vehicular headlamp 1 according to this embodiment includes a lamp unit 5 housed in a lamp chamber 4 defined by a transparent transparent cover (cover) 2 and a lamp body 3.
The lamp unit 5 is supported by the lamp body 3 via an aiming mechanism 6 including an aiming screw 6a and an aiming nut 6b. The aiming mechanism 6 is a mechanism for finely adjusting the mounting position and the mounting angle of the lamp unit 5 by adjusting the tightening by the aiming nut 6b. At the stage of adjusting the aiming, the optical axis Ax of the lamp unit 5 is It extends in the downward direction by about 0.5 to 0.6 degrees with respect to the direction.

  The lamp unit 5 is a projector-type lamp unit, and includes a projection lens 8 disposed on an optical axis Ax extending in the vehicle front-rear direction, and a rear focal point F of the projection lens 8 with the bulb axis aligned with the optical axis Ax. Also, a light source bulb (light source) 10 such as a discharge bulb or a halogen bulb arranged on the rear side, and the light L1 and L2 emitted from the light source bulb 10 with the light source bulb 10 inserted and fixed toward the front are close to the optical axis Ax. And a reflector 13 that reflects the light beam and a rear edge F near the optical axis Ax in the vicinity of the rear focal point F, and shields a part of the reflected light from the reflector 13 and a part of the direct light from the light source bulb 10. Thus, the shade mechanism 15 that forms the cut-off line of the light distribution pattern, and the substantially cylinder that is interposed between the projection lens 8 and the opening edge of the front end of the reflector 13 and serves as a connecting means for both. And a holder 17.

In the present embodiment, the holder 17 is integrally formed with an auxiliary shade 37. The auxiliary shade 37 includes an upper auxiliary shade 37a positioned at the upper part of the holder internal space and a lower auxiliary shade 37b provided at a position lower than the optical axis Ax on the lower side of the holder internal space.
The auxiliary shade 37 shields the reflector reflected light that is about to pass under the shade mechanism 15 and shields stray light that is about to enter the projection lens 8.

  The projection lens 8 is a plano-convex lens having a convex front surface and a flat rear surface, and projects an image on the focal plane including the rear focus F forward as a reverse image.

  In the case of this embodiment, the light source bulb 10 is a metal halide bulb having a light emitting portion 10a that emits light by discharge on a bulb axis (center axis), and the optical axis is aligned with the optical axis Ax. Inserted and fixed to the reflector 13 from the rear of Ax.

As shown in FIG. 2, the reflector 13 has a reflection surface 13a having a substantially elliptical spherical shape with the optical axis Ax passing through the light emitting portion 10a as a central axis.
The reflecting surface 13a has a cross-sectional shape including the optical axis Ax set to a substantially elliptical shape with the center position of the light emitting unit 10a as the first focus (F1) and the vicinity of the rear focus F of the projection lens 8 as the second focus. The light from the light emitting unit 10a is condensed and reflected toward the optical axis Ax toward the front. The eccentricity of the reflecting surface 13a is set so as to gradually increase from the vertical cross section toward the horizontal cross section.

  Further, a second reflecting surface 14 is disposed at the lower portion of the opening end in front of the reflecting surface 13 a of the reflector 13. The second reflecting surface 14 is a reflecting surface that collects and reflects a part of the direct light from the light source bulb 10 toward a first reflecting surface 22 of the first shade 20 described later.

  As shown in FIGS. 3 to 5, the shade mechanism 15 of the present embodiment has an upper edge 21 that forms the entire horizontal region of the light distribution generation unit for generating the low beam light distribution pattern in the vicinity below the optical axis Ax. Is disposed at a shielding position located near the rear focal point F of the projection lens 8 and has a plate-like first shade 20 having a rectangular light transmitting portion 55 opened on the left side of the vehicle below the upper edge 21 and light. A rectangular plate-like second shade 23 capable of opening and closing the transmission part 55; an actuator 30 for sequentially moving the second shade 23 from a closed position for closing the light transmission part 55 to a first opening position and a second opening position; And an interlocking portion 23a provided on the second shade 23 so as to move the first shade 20 from the shielding position to the shielding relaxation position when the second shade 23 moves to the second opening position.

As shown in FIGS. 3 and 4, the first shade 20 is a plate shade formed of a horizontally-long rectangular plate member erected along a surface substantially perpendicular to the optical axis Ax. The upper edge 21 has a shape that forms the entire horizontal region of the light distribution generation unit for generating a low beam light distribution pattern (uneven horizontal cut-off line). In addition, the first shade 20 has a rectangular light transmission portion 55 opened on the left side of the vehicle below the upper edge 21.
In addition, although the light transmission part 55 of this embodiment is opened on the left side of the vehicle so as to irradiate the front of the host vehicle when using a single high beam, the right side of the vehicle is opened to irradiate the front of the oncoming vehicle when using the high beam. You may comprise as follows.

The first shade 20 and the second shade 23, which are arranged so as to overlap in the front-rear direction (plate thickness direction) along the optical axis Ax, are separated from the optical axis Ax by the support pins 40 that penetrate the holder 17 in the vehicle width direction. It is supported so as to be rotatable about the same rotation center line Hx parallel to the orthogonal horizontal line.
Note that the upper edge of the second shade 23 that closes the light transmitting portion 55 of the first shade 20 passes through the upper edge 21 of the first shade 20, and the light irradiated forward cuts the low beam light distribution pattern. It is set lower than the upper edge 21 so that a color change due to a plate thickness change does not occur on the offline.

The first shade 20 can be tilted forward only by a stopper 42A provided on the rear surface side, and the second shade 23 whose rear surface is in contact with the first shade 20 is rotated at a predetermined rotation angle by a stopper 42B provided on the front surface side. It can be tilted forward only within the range.
Further, as shown in FIG. 3, the first shade 20 is urged to rotate backward by a return spring 41 which is an elastic urging member. The return spring 41 is a metal torsion coil spring. One end of the return spring 41 is locked to the back surface of the first shade 20, and the other end is locked to the holder 17 so that the first shade 20 is rotated rearward. It is energized.

  The second shade 23 is urged to rotate backward by a return spring 43 that is an elastic urging member. The return spring 43 is a metal tension coil spring. One end of the return spring 43 is locked to the interlocking portion 23a extending from the back surface of the second shade 23, and the other end is locked to the holder 17 side. 23 is urged to rotate backward.

  Therefore, the first shade 20 that is urged to rotate backward by the return spring 41 abuts against the stopper 42A and is restricted from rotating, so that the first shade 20 is in a substantially vertical state. Further, the second shade 23 that is urged to rotate backward by the return spring 43 is brought into a substantially vertical state because the back surface thereof is in contact with the first shade 20 and is restricted from rotating (see FIG. 3).

  The actuator 30 of the present embodiment is composed of a rotary motor such as a step motor, and rotationally drives the second shade 23 via a reduction gear mechanism 50. The actuator 30 is driven and controlled by a control unit (not shown) in accordance with a vehicle traveling state or a beam switching switch operation.

As shown in FIG. 4, the reduction gear mechanism 50 includes a flat gear 51 fixed to the left end of the second shade 23 concentrically with the support pin 40, and a pinion gear 53 fixed to the rotation drive shaft of the actuator 30. Prepare. The spur gear 51 can be rotated integrally with the second shade 23 by fitting a fitting protrusion 51 a provided on one side surface into a fitting hole 23 b provided in the left end of the second shade 23. Is done.
Then, by switching the rotation direction of the actuator 30, the second shade 23 is configured to tilt forward from the lamp until it comes into contact with the stopper 42B from the vertical state.

The interlocking portion 23a according to the present embodiment is a protrusion extending radially outward from the bearing portion of the second shade 23, and when the second shade 23 is rotated forward by a predetermined angle from a substantially vertical state. The first shade 20 is configured to contact the back surface of the first shade 20.
Therefore, when the second shade 23 is tilted forward of the lamp by a predetermined angle or more, the first shade 20 is also pushed by the interlocking portion 23a and tilts forward of the lamp against the spring force of the return springs 41 and 43.

  In the first shade 20 of the present embodiment, the upper end edge 21 is disposed at a shielding position located in the vicinity of the rear focal point F of the projection lens 8, and the light transmitting portion 55 is closed by the second shade 23 (see FIG. 3 and FIG. 3). In the state illustrated in FIG. 4, a low-beam light distribution pattern is formed, and in a state where the light transmission portion 55 of the first shade 20 is opened (the state illustrated in FIG. 5A), the single high-beam light distribution pattern is formed. In the state where the first shade 20 and the second shade 23 are tilted forward and the upper end edge 21 is not positioned near the rear focal point F of the projection lens 8 (the state shown in FIG. 5B), it is for high beam use. A light distribution pattern is formed.

  That is, in the vehicle headlamp 1 of the present embodiment, when the actuator 30 is driven one step and the spur gear 51 of the reduction gear mechanism 50 is rotated by a predetermined angle in one direction (counterclockwise direction in FIG. 3), As shown in FIG. 5A, the second shade 23 is tilted forward and is moved from the closed position where the light transmitting portion 55 is closed to the first open position. At this time, the first shade 20 that is urged to rotate backward by the return spring 41 abuts against the stopper 42A and remains in the shielding position. Therefore, a single high beam light distribution pattern is formed by the light emitted forward from the vehicle headlamp 1.

  Further, when the actuator 30 is driven in two stages and the spur gear 51 is further rotated by a predetermined angle in one direction, the second shade 23 is tilted forward as shown in FIG. To the second open position. At this time, the first shade 20 pushed by the interlocking portion 23a is also moved to the shielding relaxation position where the shielding amount is reduced by being tilted forward against the spring force of the return spring 41. Therefore, a high beam light distribution pattern is formed by the light emitted forward from the vehicle headlamp 1.

When the actuator 30 is rotated in the reverse direction and the spur gear 51 of the reduction gear mechanism 50 is rotated in the other direction (clockwise direction in FIG. 3), the first shade 20 and the second shade 23 are shown in FIG. Is moved to the shielding position. Further, even when the energization of the actuator 30 is interrupted, the first shade 20 and the second shade 23 are moved to the shielding position by the spring force of the return springs 41 and 43.
Therefore, a light distribution pattern for low beam is formed by light irradiated forward from the vehicle headlamp 1.

  That is, according to the vehicle headlamp 1 of the present embodiment, when the actuator 30 moves the second shade 23 to the first open position, only the light transmitting portion 55 reduces the shielding amount of the first shade 20. The other parts remain in the shield position. Further, when the actuator 30 moves the second shade 23 to the second opening position, the first shade 20 is also moved to the shielding relaxation position where the shielding amount is reduced.

Therefore, the shade mechanism 15 includes a low-beam light distribution pattern in which the light transmission portion 55 of the first shade 20 is closed by the second shade 23, and a piece that reduces the shielding amount only when this portion is opened. The high beam light distribution pattern and the high beam light distribution pattern in which the shielding amount of the first shade 20 is reduced can be switched by one actuator 30.
At this time, since the entire horizontal region of the light distribution generation unit for generating the low beam light distribution pattern is formed by the upper edge 21 of the first shade 20, the shade is divided into the first shade 20 and the second shade 23. In spite of being divided, there is no light leakage, color change, or light distribution step due to the division in the cut-off line of the light distribution pattern for low beam irradiated forward.

  Therefore, the vehicle headlamp 1 according to the present embodiment drives and controls the actuator 30 according to the situation of the vehicle existing ahead by a control unit (not shown) and rotates the second shade 23 according to the vehicle running situation. By changing the light distribution characteristic of the own vehicle formed by light irradiation from the lamp unit 5, the forward visibility of the own vehicle is enhanced without dazzling the oncoming vehicle and the preceding vehicle, and the cut-off line is excellent. A light distribution pattern can be obtained.

  In addition, the vehicle headlamp 1 according to the present embodiment is biased to the shielding position by the return springs 41 and 43 when a failure such as interruption of the power supply to the actuator 30 occurs during the traveling single high beam or high beam irradiation. Since the first shade 20 and the second shade 23 that have been rotated and returned until the first shade 20 is locked to the stopper 42A, the glare to the oncoming vehicle can be prevented by automatically returning to the low beam irradiation. Can do.

  Furthermore, as shown in FIG. 6, the second opening disposed at the lower end of the opening end of the reflector 13 is located at the upper opening edge (opening edge) of the light transmitting portion 55 of the first shade 20 according to the shade mechanism 15 of the present embodiment. A first reflecting surface 22 is provided that reflects a part of the direct light from the light source bulb 10 condensed and reflected by the reflecting surface 14 toward the front.

That is, instead of the part L3 of the reflected light of the reflector 13 that is blocked by the upper edge 21 of the first shade 20, the second reflecting surface 14 directs a part L4 of the direct light that is not used toward the first reflecting surface 22. The first reflection surface 22 is configured to reflect the light L4 from the rear toward the front.
Therefore, the light reflected from the reflector 13 is blocked by the upper edge 21 of the first shade 20, so that light leakage occurring in the one-high beam light distribution pattern can be prevented, and a good light distribution pattern in which the driver does not feel uncomfortable is obtained. Can do.

In addition, the specific configurations of the first shade, the light transmission unit, the second shade, the actuator, the first reflection surface, the second reflection surface, and the shade mechanism in the above embodiment are not limited to the above embodiment. If the required light distribution switching operation can be obtained, the design can be changed as appropriate.
For example, in the shade mechanism 15 of the above-described embodiment, a pulse motor is used as the actuator 30, but a configuration in which the second shade is sequentially moved by a two-stage solenoid is also possible.
Furthermore, in the shade mechanism 15 of the above embodiment, the first shade and the second shade are moved using one actuator 30, but the first shade and the second shade can be moved by using two actuators. It is also possible to adopt a configuration in which they are moved independently.

1 Vehicle headlamp 2 Transparent cover (cover)
3 Lamp body 5 Lamp unit 8 Projection lens 10 Light source bulb (light source)
DESCRIPTION OF SYMBOLS 10a Light emission part 13 Reflector 14 2nd reflection surface 15 Shade mechanism 17 Holder 20 1st shade 21 Upper end edge 22 1st reflection surface 23 2nd shade 30 Actuator 55 Light transmission part

Claims (4)

In a lamp chamber formed by a lamp body and a cover, a projection lens disposed on an optical axis extending in the vehicle front-rear direction, a light source disposed on the rear side of the projection lens, and light from the light source directed forward A reflector that reflects near the optical axis, and a light distribution pattern that is disposed between the projection lens and the light source to shield a part of the reflected light from the reflector and a part of the direct light from the light source. A vehicle headlamp having a shade mechanism that forms a cut-off line of
The shade mechanism is
An upper end edge that forms the entire horizontal region of the light distribution generation unit for generating the low beam light distribution pattern is disposed at a shielding position located in the vicinity of the rear focal point of the projection lens, and light is emitted at least below the upper end edge. A plate-like first shade having a transparent portion opened;
A plate-like second shade capable of opening and closing the light transmission part;
An actuator for moving the second shade to a closed position for closing the light transmitting portion and an open position for opening the light transmitting portion;
A vehicle headlamp characterized by comprising:   2. The vehicular headlamp according to claim 1, wherein the first shade is movable to a shielding relaxation position that reduces a shielding amount with respect to reflected light from the reflector more than the shielding position.   3. The vehicle according to claim 1, wherein a first reflection surface that reflects a part of light from the rear toward the front is provided at an opening edge of the light transmission portion of the first shade. Headlight.   The second reflection surface that reflects a part of direct light from a light source toward the first reflection surface is disposed between the reflector and the first shade. Vehicle headlamps.

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