JP4002099B2 - Vehicle headlamp - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle headlamp including a lamp unit for low beam irradiation.
[0002]
[Prior art]
In general, a vehicle headlamp is configured to perform beam irradiation forward with a predetermined light distribution pattern by a lamp unit including a light source and a reflector that reflects light from the light source forward.
[0003]
At that time, in the lamp unit for low beam irradiation, by performing beam irradiation with a low beam light distribution pattern having a predetermined cut-off line at the upper edge, it is possible to prevent glare from the oncoming vehicle driver, etc. It is configured to ensure forward visibility as much as possible.
[0004]
[Problems to be solved by the invention]
However, under the following vehicle running conditions, there is a problem that it is difficult to obtain sufficient forward visibility by beam irradiation from a lamp unit for low beam irradiation.
[0005]
In other words, when driving at high speed, the driver of the vehicle will drive while paying attention to the distant road surface, but light irradiation with the normal low beam light distribution pattern does not irradiate light above the cut-off line height. There is a problem that the visibility of the distant road surface cannot be sufficiently ensured during high-speed driving at night.
[0006]
The present invention has been made in view of such circumstances, and in a vehicle headlamp provided with a lamp unit for low beam irradiation, the visibility of a distant road surface is sufficient when traveling at high speed in a low beam irradiation state. An object of the present invention is to provide a vehicular headlamp that can be secured.
[0007]
[Means for Solving the Problems]
The present invention is intended to achieve the above object by adopting a configuration in which a predetermined auxiliary light distribution pattern can be additionally formed using a movable shade.
[0008]
That is, the vehicle headlamp according to the present invention is
In a vehicle headlamp configured to perform beam irradiation with a low beam light distribution pattern having a predetermined cut-off line at an upper end edge by a lamp unit including a light source and a reflector that reflects light from the light source forward ,
A movable shade configured to be able to adopt a shielding position for shielding a part of light incident on the reflector from the light source and a shielding release position for releasing the shielding, and the movable shade as the shielding position and the shielding release position. A shade drive device that moves between
The shade driving device is configured to move the movable shade to the shielding position when it is below a predetermined set vehicle speed, and to move the movable shade to the shielding release position when the set vehicle speed is exceeded.
When the movable shade is in the shielding position, beam irradiation is performed with the low beam light distribution pattern. On the other hand, when the movable shade is in the shielding release position, the cutoff line is above the cutoff line of the low beam distribution pattern. The auxiliary light distribution pattern having the above is added to the low beam light distribution pattern to perform the beam irradiation ,
The auxiliary light distribution pattern is set as a high luminous intensity light distribution pattern formed so as to widen the hot zone of the low beam light distribution pattern toward the own lane side and the opposite lane side, and the auxiliary light distribution pattern is cut. The off-line is set as a cut-off line extending substantially parallel to the cut-off line in the vicinity of the upper part of the cut-off line of the low beam light distribution pattern .
[0009]
As long as the “lamp unit” includes a light source and a reflector that reflects light from the light source forward, the specific configuration is not particularly limited, and the main light distribution control is performed by the reflector. It may be configured as described above, or may be configured such that a lens is provided in front of the reflector and main light distribution control is performed by the lens.
[0010]
The specific configuration of the “light source” is not particularly limited, and may be a discharge light emitting part of a discharge bulb, an incandescent bulb filament such as a halogen bulb, or the like.
[0011]
As long as the “movable shade” is configured so as to be able to adopt the shielding position and the shielding release position, the specific configuration such as the shape and size thereof is not particularly limited.
[0012]
The specific position of the “shielding release position” is particularly limited as long as the shielding amount of light incident on the reflector from the light source can be made smaller than when the movable shade is in the shielding position. It does not necessarily have to be a position where the shielding against the light incident on the reflector from the light source can be completely released.
[0013]
The above-described “shade driving device” is not particularly limited as long as it is configured to move the movable shade between the shielding position and the shielding release position. For example, a solenoid is used. A thing using a thing or a pulse motor etc. is employable. Further, the mode of “movement” of the movable shade by the shade driving device is not particularly limited, and for example, rotation or linear reciprocation can be adopted.
[0014]
As long as the “low beam light distribution pattern” has a predetermined cut-off line at the upper edge, the cut-off line shape is not particularly limited .
[0015]
The specific position of the “predetermined set vehicle speed” is not particularly limited, and can be set to an appropriate value (for example, 70 km / hr) within a range of 60 to 80 km / hr, for example.
[0016]
[Effects of the invention]
As shown in the above configuration, the vehicle headlamp according to the present invention is configured to be able to adopt a shielding position for shielding a part of light incident on the reflector from the light source and a shielding releasing position for releasing the shielding. A movable shade, and a shade driving device that moves the movable shade to a shielding position when the vehicle speed is lower than a predetermined set vehicle speed, while moving the movable shade to a shielding release position when the set vehicle speed is exceeded. When the movable shade is in the shield release position, the cut-off line is provided above the cut-off line of the low-beam light distribution pattern. The auxiliary light distribution pattern is added to the low beam light distribution pattern to perform beam irradiation. , It is possible to obtain the following effects.
[0017]
In other words, when driving at high speed when the driver's point of interest is on the far road surface, the auxiliary light distribution pattern is added to the low beam light distribution pattern, so that the beam irradiation on the far road surface can be sufficiently performed, thereby Visibility can be improved.
[0018]
Moreover, since the auxiliary light distribution pattern has a cut-off line, even when this auxiliary light distribution pattern is added to the low beam light distribution pattern, the entire light distribution pattern has a cut-off line. This cut-off line is positioned above the cut-off line of the normal low-beam light distribution pattern, but the distance between the vehicle and the preceding vehicle is generally longer when driving at high speeds, so a large glare is applied to the driver of the preceding vehicle. Never give. In addition, since the vehicle is unlikely to pitch greatly during high-speed driving, the oncoming vehicle driver, etc. even when the cut-off line position of the auxiliary light distribution pattern is set slightly above the cut-off line of the normal low beam light distribution pattern Will never give a big glare.
[0019]
As described above, according to the present invention, in a vehicle headlamp equipped with a lamp unit for low beam irradiation, it is possible to sufficiently ensure the visibility of a distant road surface when traveling at high speed in a low beam irradiation state. As a result, traveling safety during high-speed traveling can be improved.
[0020]
In addition, in the present invention, since the auxiliary light distribution pattern is added by moving the movable shade, the auxiliary light distribution pattern can be formed with high accuracy by an inexpensive and compact configuration.
[0021]
In the above configuration, the shape of the cut-off line of the auxiliary light distribution pattern is not particularly limited as described above, but if this is set to substantially the same shape as the cut-off line of the low beam light distribution pattern, the auxiliary light distribution pattern is added. In addition, the addition cancellation can be performed without causing the driver of the vehicle to feel uncomfortable.
[0022]
Further, in the above configuration, if the configuration includes a leveling device that changes the irradiation direction of the beam irradiated from the lamp unit for low beam irradiation in the vertical direction according to the posture change of the vehicle body, the low beam light distribution pattern and It is possible to always maintain the vertical angular position of the auxiliary light distribution pattern at a substantially constant level. Therefore, the position of the cut-off line of the auxiliary light distribution pattern can be set higher by the amount that it is not necessary to consider the occurrence of glare due to the vertical movement of the light distribution pattern due to the pitching of the vehicle body. Can be further enhanced.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0024]
FIG. 1 is a plan sectional view showing a vehicle headlamp according to an embodiment of the present invention.
[0025]
As illustrated, the vehicle headlamp 10 according to the present embodiment is a lamp located on the left side of a pair of left and right four-lamp headlamps provided at the front end of the vehicle. The lamp located on the right side has the same configuration.
[0026]
The vehicular headlamp 10 includes a high beam lamp unit 16 and a low beam lamp unit 18 which are disposed adjacent to each other in the left-right direction in a lamp chamber formed by a transparent translucent cover 12 and a lamp body 14. One tilting unit 20 is provided so as to be tiltable in the vertical and horizontal directions. The vehicular headlamp 10 irradiates a low beam when the low beam lamp unit 18 is turned on, and also performs a high beam irradiation when both the lamp units 16 and 18 are turned on simultaneously.
[0027]
The high beam lamp unit 16 includes a parabolic reflector 22 having an optical axis Ax1 extending in the vehicle front-rear direction, and a halogen bulb 24 having a single filament 24a. The halogen bulb 24 is supported by the reflector 22 so that the filament 24a is positioned on the optical axis Ax1. The reflector 22 has a reflecting surface 22a in which a plurality of reflecting elements (not shown) are formed on a rotating paraboloid with the optical axis Ax1 as the central axis, and the light from the filament 24a is directed forward. And diffused and reflected.
[0028]
On the other hand, the low beam lamp unit 18 includes a parabolic reflector 26 having an optical axis Ax2 extending in the vehicle front-rear direction, a discharge bulb 28 having a discharge light emitting portion 28a (light source), and a movable shade 30 (which will be described later). It is equipped with. The discharge bulb 28 is supported by the reflector 26 via a bulb support member 38 so that the discharge light emitting portion 28a is positioned on the optical axis Ax2. The reflector 26 has a reflecting surface 26a in which a plurality of reflecting elements (not shown) are formed on a rotating paraboloid with the optical axis Ax2 as the central axis, and transmits light from the discharge light emitting unit 28a forward. It is designed to reflect diffusely deflected toward.
[0029]
The reflector 22 of the high beam lamp unit 16 and the reflector 26 of the low beam lamp unit 18 are integrally formed via a tilt unit panel 20a, thereby constituting the tilt unit 20. The tilting unit 20 is supported by the lamp body 14 via the aiming mechanisms 32 and 34 at the left and right upper ends thereof, and is supported by the lamp body 14 via the leveling device 36 at the lower end of the center thereof.
[0030]
The tilting unit 20 tilts in the vertical direction by driving the leveling device 36. Specifically, when a posture change due to pitching occurs in the vehicle body while the vehicle is running, the tilting unit 20 is tilted in the vertical direction by driving the leveling device 36, and the beams irradiated from the both lamp units 16, 18 are emitted. The irradiation direction is always kept constant.
[0031]
2 is a detailed view of the main part of FIG. 1 showing the low beam lamp unit 18 in detail, FIG. 3 is a sectional view taken along the line III-III of FIG. 2, and FIG. FIG.
[0032]
As shown in these figures, the movable shade 30 is provided so as to be able to reciprocate in the front-rear direction so as to cover the discharge bulb 28 in a cup shape from the front side. The shield release position indicated by the dotted line can be taken. When the movable shade 30 is in the shielding position, the movable shade 30 shields light incident on the left and right peripheral edge portions B and C of the reflecting surface 26a of the reflector 26 from the discharge light emitting portion 28a, and enters the central portion A of the reflecting surface 26a. While only light incidence is allowed, when it is in the shielding release position, this shielding is released to allow light incidence from the discharge light emitting portion 28a to the left and right peripheral portions B and C of the reflecting surface 26a.
[0033]
The movable shade 30 is moved by driving the shade driving device 40. The shade driving device 40 is composed of a solenoid with a built-in return spring, and is fixed to the bulb support member 38 below the discharge bulb 28 so that the plunger 40a protrudes forward. The lower end portion of the stay 30 a extending downward from the lower end portion of the movable shade 30 is fixed to the distal end portion of the plunger 40 a of the shade driving device 40.
[0034]
As shown in FIG. 3, the shade driving device 40 is driven and controlled by the control unit 50.
[0035]
That is, the detection signal from the vehicle speed sensor 52 is input to the control unit 50. The control unit 50 outputs a drive signal to the shade drive device 40 when the vehicle speed exceeds a predetermined set vehicle speed (for example, 70 km / hr) and enters a high speed running state. When this drive signal is input, the shade drive device 40 excites the solenoid to advance the plunger 40a to the two-dot chain line position and move the movable shade 30 to the shielding release position, while the drive signal is input. When there is no more (that is, when the vehicle speed is reduced to the set vehicle speed or less and the vehicle enters a low / medium speed running state), the solenoid is de-energized and the plunger 40a is moved backward to the solid line position by the elastic force of the return spring, The movable shade 30 is moved to the shielding position.
[0036]
FIGS. 5 and 6 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 beam irradiation from the vehicle headlamp 10 according to the present embodiment. FIG. 5 is for low and medium speed travel, and FIG. 6 is for high speed travel.
[0037]
As shown in FIG. 5, in the low and medium speed traveling state, the vehicular headlamp 10 has a left light distribution as shown in FIG. 5A due to the beam irradiation from the low beam lamp unit 18 during the low beam irradiation. While the light distribution pattern for low beam P (L) is formed, the light distribution pattern for low beam P (L) as shown in FIG. A light distribution pattern in which the high beam light distribution pattern P (H) is superimposed is formed.
[0038]
The low beam light distribution pattern P (L) is a light distribution pattern formed by the reflected light from the central portion A of the reflecting surface 26a of the reflector 26 in a state where the movable shade 30 is at the shielding position, and is formed at the upper end edge thereof. It has a cut-off line composed of a horizontal cut-off line CL1 and an oblique cut-off line CL2.
[0039]
The horizontal cut-off line CL1 is formed on the opposite lane side with respect to the lamp front direction (HV), while the oblique cut-off line CL2 rises obliquely from the horizontal cut-off line CL1 toward the own lane (for example, 15 °). To stand up). An intersection (elbow point) E between the horizontal cut-off line CL1 and the oblique cut-off line CL2 is set at a position 0.5 to 0.6 ° below HV. In the low beam light distribution pattern P (L), a hot zone (high light intensity region) HZ (L) is formed in the lower left vicinity region of the elbow point E.
[0040]
The hot zone in the light distribution pattern at the time of high beam irradiation is the high beam light distribution pattern P (H) formed around the HV in the hot zone HZ (L) of the low beam light distribution pattern P (L). The hot zone HZ (H) is superimposed.
[0041]
As shown in FIG. 6, in the high-speed traveling state, auxiliary light distribution patterns P (B) and P (C) are added around the hot zone HZ (L) of the low beam light distribution pattern P (L). It has become. These auxiliary light distribution patterns P (B) and P (C) are additionally formed by reflected light from the left and right peripheral edge portions B and C of the reflecting surface 26a of the reflector 26 in a state where the movable shade 30 is at the shielding release position. Is a light distribution pattern.
[0042]
The auxiliary light distribution pattern P (B) formed by the reflected light from the peripheral edge B on the right side (left side in FIG. 4) of the reflecting surface 26a is formed so as to widen the hot zone HZ (L) toward the own lane. The upper end edge of the light distribution pattern having a relatively small luminous intensity is formed as an oblique cut-off line CLb extending substantially parallel to the oblique cut-off line CL2 in the vicinity of the upper side of the oblique cut-off line CL2.
[0043]
On the other hand, the auxiliary light distribution pattern P (C) formed by the reflected light from the peripheral edge C on the left side (right side in FIG. 4) of the reflective surface 26a extends the hot zone HZ (L) to the opposite lane side. a light distribution pattern of relatively small high intensity to be formed, the upper end edge is formed as a horizontal cut-off line CL c extending substantially parallel to the horizontal cutoff line CL1 at an upper vicinity of the horizontal cutoff line CL1.
[0044]
By combining these two auxiliary light distribution patterns P (B) and P (C), a new elbow point E ′ is formed by the horizontal cutoff line CLc and the oblique cutoff line CLb. The position is set to the position HV.
[0045]
In the present embodiment, the auxiliary light distribution patterns P (B) and P (C) are added in the high-speed running state even during high beam irradiation. Thereby, the hot zone in the light distribution pattern at the time of high beam irradiation is the hot zone HZ (L) of the low beam light distribution pattern P (L) and the hot zone HZ (H) of the high beam light distribution pattern P (H). The auxiliary light distribution patterns P (B) and P (C) are overlapped to form a hot zone that is as bright and large as possible.
[0046]
As described above in detail, in the vehicle headlamp 10 according to the present embodiment, the low beam lamp unit 18 shields a part of the light incident on the reflector 26 from the discharge light emitting unit 28a and the shielding. The movable shade 30 configured to be capable of adopting the shielding release position for releasing the vehicle and the movable shade 30 is moved to the shielding position when the vehicle speed is lower than the set vehicle speed, and is moved to the shielding release position when the vehicle speed exceeds the set vehicle speed. When the movable shade 30 is in the shielding position, the beam is irradiated with a low beam light distribution pattern P (L) having a horizontal cut-off line CL1 and an oblique cut-off line CL2 on the upper edge when the movable shade 30 is in the shielding position. When the movable shade 30 is in the shielding release position, the cutoff beam of the low beam light distribution pattern P (L) The auxiliary light distribution patterns P (B) and P (C) having the cutoff lines CLb and CLc above the lines CL1 and CL2 are added to the low beam light distribution pattern P (L) to perform beam irradiation. Therefore, the following effects can be obtained.
[0047]
That is, during high-speed driving where the driver's gaze point is on the far road surface, the auxiliary light distribution patterns P (B) and P (C) are added to the low beam light distribution pattern P (L). Can be sufficiently performed, thereby improving the visibility with respect to a distant road surface.
[0048]
Moreover, since the auxiliary light distribution patterns P (B) and P (C) have cut-off lines CLb and CLc, these auxiliary light distribution patterns P (B) and P (C) are used as the low beam light distribution pattern P (L ), The entire light distribution pattern has cut-off lines CLb and CLc. The cut-off lines CLb and CLc are located above the cut-off lines CL1 and CL2 of the normal low-beam light distribution pattern P (L), but generally, the inter-vehicle distance from the preceding vehicle becomes longer during high speed running. Therefore, it does not give a big glare to the driver of the preceding car. Further, since the vehicle is unlikely to pitch greatly during high-speed traveling, the positions of the cut-off lines CLb and CLc of the auxiliary light distribution patterns P (B) and P (C) are set to the cut-off line of the normal low beam light distribution pattern P (L). Even when it is set slightly above CL1 and CL2, no large glare is given to the oncoming vehicle driver or the like.
[0049]
As described above, according to the present embodiment, it is possible to sufficiently ensure the visibility of the far road surface during high-speed traveling in the low beam irradiation state, thereby improving traveling safety.
[0050]
In addition, in the present embodiment, the auxiliary light distribution patterns P (B) and P (C) are added by moving the movable shade 30, so that the auxiliary distribution with high accuracy can be achieved with an inexpensive and compact configuration. Optical patterns P (B) and P (C) can be formed.
[0051]
In particular, in the present embodiment, the shapes of the cut-off lines CLb and CLc of the auxiliary light distribution patterns P (B) and P (C) are set to substantially the same shapes as the cut-off lines CL1 and CL2 of the low beam light distribution pattern P (L). Thus, the auxiliary light distribution patterns P (B) and P (C) can be added and released without causing the driver of the vehicle to feel uncomfortable.
[0052]
Further, in this embodiment, when a posture change due to pitching occurs in the vehicle body while the vehicle is traveling, the beam irradiated from both lamp units 16 and 18 by tilting the tilting unit 20 vertically by driving the leveling device 36. Is always kept in a fixed direction, so the cut-off lines CL1 and CL2 of the low beam light distribution pattern P (L) and the cut-off lines CLb of the auxiliary light distribution patterns P (B) and P (C), The angular position of CLc in the vertical direction can always be kept substantially constant.
[0053]
Accordingly, the positions of the cut-off lines CLb and CLc of the auxiliary light distribution patterns P (B) and P (C) are set higher as much as it is not necessary to consider the occurrence of glare due to the vertical movement of the light distribution pattern accompanying the pitching of the vehicle body. can do. In the present embodiment, the direction of the horizontal cut-off line CLc of the auxiliary light distribution pattern P (B) is set on the HH line which is a limit position where the auxiliary light distribution pattern P (B) does not face upward. And the visibility of a distant road surface can be improved further by setting in this way.
[0054]
By the way, like the vehicle headlamp 10 according to the present embodiment, the reflector 22 of the high beam lamp unit 16 and the reflector 26 of the low beam lamp unit 18 are integrally formed via the tilting unit panel 20a. In this case, in order to improve the visibility of the distant road surface, it is impossible to change only the direction of the low beam lamp unit 18 upward, and the direction of the reflector 26 may be partially changed. It's not easy. In this respect, in the present embodiment, since the movable shade 30 is used, it is possible to easily perform beam irradiation for improving the visibility of the far road surface.
[0055]
In the present embodiment, in the high-speed traveling state, the auxiliary light distribution patterns P (B) and P (C) are added even during high beam irradiation. Although the hot zone in the light pattern can be bright and large, at the time of high beam irradiation, the hot zone HZ (L) of the low beam light distribution pattern P (L) and the hot zone HZ of the high beam light distribution pattern P (H) Since a certain degree of brightness can be secured by superimposing with (H), the auxiliary light distribution patterns P (B) and P (C) should not be added during high-beam irradiation even in a high-speed traveling state. May be.
[Brief description of the drawings]
FIG. 1 is a plan sectional view showing a vehicle headlamp according to an embodiment of the present invention. FIG. 2 is a detailed view of a main part of FIG. 1, showing a low beam lamp unit of the vehicle headlamp in detail. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a view taken in the direction of arrow IV in FIG. 3. FIG. 5 is 25 m ahead of the lamp due to beam irradiation from the vehicle headlamp when traveling at low and medium speeds. FIG. 6 is a perspective view showing a light distribution pattern formed on a virtual vertical screen arranged at the position of FIG. 6; FIG. 6 shows the position 25 m ahead of the lamp due to beam irradiation from the vehicle headlamp when traveling at high speed. The figure which shows the light distribution pattern formed on the virtual vertical screen arrange | positioned in FIG.
DESCRIPTION OF SYMBOLS 10 Vehicle headlamp 12 Transparent cover 14 Lamp body 16 High beam lamp unit 18 Low beam lamp unit 20 Tilt unit 20a Tilt unit panel 22, 26 Reflector 22a Reflecting surface 24 Halogen bulb 24a Filament 28 Discharge bulb 28a Discharge light emitting part (light source) )
30 Movable shade 30a Stay 32, 34 Aiming mechanism 36 Leveling device 38 Valve support member 40 Shade drive device 40a Plunger 50 Control unit 52 Vehicle speed sensor A Center portion Ax1, Ax2 Optical axis B Right peripheral portion C Left peripheral portion CL1, CLb Horizontal cut-off line CL2, CLc Oblique cut-off line E, E 'Elbow point HZ (L), HZ (H) Hot zone P (B), P (C) Auxiliary light distribution pattern P (H) High beam light distribution pattern P ( L) Light distribution pattern for low beam

Claims (2)

In a vehicle headlamp configured to perform beam irradiation with a low beam light distribution pattern having a predetermined cut-off line at an upper end edge by a lamp unit including a light source and a reflector that reflects light from the light source forward ,
A movable shade configured to be able to take a shielding position for shielding a part of light incident on the reflector from the light source and a shielding release position for releasing the shielding, and the movable shade at the shielding position and the shielding release position. A shade drive device that moves between
The shade driving device is configured to move the movable shade to the shield position when the shade speed is equal to or lower than a predetermined set vehicle speed, and to move the movable shade to the shield release position when the set vehicle speed is exceeded.
When the movable shade is in the shielding position, beam irradiation is performed with the low beam light distribution pattern. On the other hand, when the movable shade is in the shielding release position, the cutoff line is above the cutoff line of the low beam distribution pattern. The auxiliary light distribution pattern having the above is added to the low beam light distribution pattern to perform beam irradiation ,
The auxiliary light distribution pattern is set as a high luminous intensity light distribution pattern formed so as to widen the hot zone of the low beam light distribution pattern toward the own lane side and the opposite lane side, and the auxiliary light distribution pattern is cut. The vehicular headlamp , wherein the off-line is set as a cut-off line extending substantially parallel to the cut-off line in the vicinity of the upper part of the cut-off line of the low beam light distribution pattern . Becomes provided with a leveling device for varying the vertical direction in accordance with the irradiation direction of the beam emitted from the lamp unit to the vehicle body attitude change, the vehicle headlamp according to claim 1, wherein a.

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