JP3224951B2 - Projection type automotive headlamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type headlamp for projecting and distributing reflected light from a substantially ellipsoidal reflector forward by a projection lens, and more particularly to a projection headlamp in front of the reflector and substantially at the focal point of the projection lens. The present invention relates to a projection type vehicle headlamp which adjusts a clear cut line of a light distribution pattern up and down by rotating a light distribution control shade horizontally disposed in a vehicle.

[0002]

2. Description of the Related Art As a prior art of this kind of headlamp, there is Japanese Utility Model Laid-Open No. 5-97004. This is a structure in which a shade 3 for forming a clear cut line between a reflector 1 and a projection lens 2 is horizontally disposed as shown in FIG. at a predetermined angular position, shape and the blade 4 are provided having different, by rotating the shade 3 into rotational center axis L ₁ about, is that clear-cut line of the light distribution pattern is changed. Reference symbol M is a motor for rotating the shade 3.

Another example of the prior art is disclosed in
No. 342901. This is shown in FIG.
The left and right shades 5a and 5b which are coaxial and have different diameters can be independently rotated around a common horizontal support shaft 6, and the rotation center (axis) L ₁ of the shade 5 (5a and 5b).
Is eccentric with respect to the center O ₁ , O ₂ of the outer shape (circle) of the shade 5 (5a, 5b) as shown in FIG. 10, and by rotating the shade 5 (5a, 5b), the shade 5 (5a, 5b) where the position (height) of the uppermost edge changes, whereby the clear cut line of the light distribution pattern changes vertically in the preceding vehicle and the oncoming vehicle independently. It is.

The symbols M ₁ and M ₂ are shades 5a and 5
Motors for rotating b, and symbols P ₁ and P ₂ are potentiometers for detecting the rotating positions of the shades 5a and 5b.

[0005]

However, the above-described first method
In the prior art, proper clear-cut line is formed when the blade 4 is positioned directly above the pivot center L _1, in the transient state of switching of the clear-cut line, inappropriate and blurred clear-cut Lines appear, visibility is impaired, and it is dangerous.

On the other hand, in the second prior art, various light distribution patterns can be formed because the left and right shades 5a and 5b can rotate independently of each other. However, a drive motor, a potentiometer, etc. However, there are problems that two are required, the structure becomes complicated, and the cost increases. Furthermore shade and structure cylindrical shade 5 (5a, 5b) is to be rotated around O _1, O ₂ eccentric to (offset amount d _1, d ₂₎ the rotational center (the axis) L ₁ around the circle The shade 5 which was initially on the focus of the projection lens 2
The uppermost edge position of (5a, 5b) may move along the optical axis with the rotation of the shade, and the light distribution pattern may be unclear.

The inventor has specifically examined a situation in which the clear cut line is desired to be changed according to the presence or absence of an oncoming vehicle and a preceding vehicle. At least a mode in which an oncoming vehicle exists and a case where a preceding vehicle does not exist, and a case where neither the preceding vehicle nor an oncoming vehicle exists, can be considered. Then, in traveling, at least clear cut lines corresponding to these aspects may be formed. Further, when forming the cross-sectional shape of the cylindrical shade into a predetermined shape having a different distance from the center of rotation for each predetermined rotation angle with respect to a circle, the clear cut line is a front vehicle side cut line and an oncoming vehicle side. It is common to change one of the cut lines up and down while fixing the other,
Even if the preceding vehicle-side cut line forming region (right shade) and the oncoming vehicle-side cut line forming region (left shade) of the cylindrical shade are integrally formed, shading processing is not so troublesome. Furthermore, if the outer shape of the shade is a predetermined shape based on this circle, the uppermost edge position of the shade contributing to the formation of the clear cut line may change in the optical axis direction even if the shade is rotated. The present invention has been made based on the finding that there is no such element.

The present invention has been made on the basis of the above-mentioned problems of the prior art and the above-mentioned knowledge of the inventor, and an object of the present invention is to provide a simple structure with a clear cut line of a light distribution pattern adapted to the running condition of an automobile. It is an object of the present invention to provide a projection type vehicle headlamp which can be made appropriate and clear.

[0009]

According to a first aspect of the present invention, there is provided a projection-type automotive headlamp comprising: a substantially ellipsoidal reflector; and a light source disposed at a first focal point of the reflector. And a projection lens disposed in front of the reflector, and a coaxial preceding vehicle-side clear cut line horizontally disposed across the reflector near the second focal point of the reflector and substantially at the focal point of the projection lens. And a cylindrical shade for forming an oncoming vehicle-side clear cut line,
In a projection-type automotive headlamp in which the clear cut line of the light distribution pattern is adjusted up and down by rotating the shade around a rotation center axis, the shade is integrated, and the outer cross-sectional shape of each shade To
It is a predetermined irregular circular shape whose distance from the center of rotation is different in the circumferential direction. According to claim 2, in the projection type headlamp for a vehicle according to claim 1,
The center of rotation of the shade is made to substantially coincide with the center of gravity of the cross section of the shade.

[0010]

When the shade having a circular cross section and a circular shape is rotated around the rotation center axis, the uppermost edge position of the shade immediately above the center of rotation of the shade hardly changes in the optical axis direction and continuously in the vertical direction. And the clear cut line of the light distribution pattern changes continuously in the vertical direction while maintaining sharpness. The outer shape of the cross section of the left and right shades is different from each other, and it is a predetermined distorted circular shape that can form the optimal clear cut line according to the presence of the preceding vehicle and the oncoming vehicle, so that the light distribution pattern clear cut The line can be changed according to the presence or absence of the preceding vehicle and the oncoming vehicle. According to the second aspect, since the center of rotation of the shade substantially coincides with the center of gravity of the distorted circle serving as the outer shape of the shade, the (inertial) weight of the shade becomes a torque around the center axis of rotation and acts on the shade rotating mechanism. I can't. That is, as shown in FIG. 10, when the center of gravity and the rotational center (the axis) L ₁ of the shade 5 is that (the eccentricity and d) an eccentric includes a shade 5
The torque (wd) due to the weight w of the eccentric shade 5 (5a, 5b) always acts as a load on the output shaft of the motor for rotating the (5a, 5b), and furthermore, the driving of the automobile and the engine. Vibration caused by vibration is transmitted,
Torque w ₁ · d (> w ·) due to the inertial weight w ₁ of the shade
d) also acts as a load and may hinder the smooth rotation of the shade, but there is no such problem in claim 2.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 7 show a headlamp for a projection type vehicle according to an embodiment of the present invention, which is used for a left-hand vehicle in Japan and the like. FIG. 1 shows the internal structure of the headlamp. FIG. 2 is a left-right vertical sectional view of a shade provided in the headlamp, FIG. 3 is a perspective view of a light distribution pattern made by the shade and the headlamp from the driver side, and FIG. FIG. 5 is a side view, FIG. 5 is a diagram for explaining the shape of the shade, (a) is a diagram showing the outer shape of the left shade, and (b) is a diagram showing the outer shape of the right shade. 6 (a) to 6 (f) are diagrams showing a change of a clear cut line of a light distribution pattern formed by the head lamp, and FIG. 7 is a configuration diagram of a control device for controlling rotation of a shade.

In these figures, a light projection unit 10 supported by an aiming mechanism (not shown) is accommodated in a container-like lamp body (not shown).
Although not described in detail, the light projection unit 10 is supported by an aiming mechanism so as to be tiltable around a horizontal axis and a vertical axis (not shown), and emission of light emitted from the light projection unit 10 by operating the aiming mechanism. The direction, that is, the irradiation axis (optical axis) L of the headlamp, can be tilted and adjusted vertically and horizontally.

The light projection unit 10 includes a substantially elliptical reflector 14 into which a bulb 12 as a light source is inserted.
The projection lens 16 is supported by a lens holder 18 fixed to the reflector 14 with a screw, in a structure in which the projection lens 16 disposed in front of the reflector 14 is integrated. Inside the reflector 14 ellipsoidal reflective surface 15 which is aluminized is formed, the elliptical reflecting surface 15 has a a first focus F ₁ of the known and the second focus F _2, the focus F ₁
In this position the filament of the bulb 12 is located. Further, near the second focal point F _{2 and} at the focal position of the projection lens 16, a shade 20 for blocking a part of the light reflected by the reflector 14 and traveling toward the projection lens 16 to form a clear cut line of the sub beam is provided. Is provided. The light emitted from the bulb 12 is reflected by the elliptical reflecting surface 15 and guided forward, and is projected and distributed by the projection lens 16 into substantially parallel light in front of the headlamp.

As shown in the figure, the shade 20 has a left side (reflector 15) made of a cylindrical body having substantially the same size.
Shade 21 and right side (reflector 1)
The shade 22 is formed integrally and concentrically and is rotatably supported by a horizontal support shaft 23 which is supported by a pair of frames 25 and extends horizontally. Reference numerals 23a and 23a denote a horizontal support shaft 23 and a shade 2
This is a bearing that is interposed between 0 and supports both ends of the shade 20.

The gear 27 is axially attached to both ends of the shade 20, the gear 27 is in mesh with a driving gear 29 axially mounted on the output shaft of the motor M _1, the shade 20 is rotating by the driving of the motor M ₁ Move. Rotation center O of shade 20
Is substantially coincident with the center of gravity of the shade 20, the motor M
_The load applied to _one output shaft is small, and the shade 20 can be smoothly and appropriately rotated.

The other gear 28 meshes with a gear 29a which is mounted on an input shaft of a rotation angle detector 40 such as a rotary encoder or a potentiometer, and the rotational position of the shade 20 is determined by the rotation angle detector 40. It is detected and output to the control unit (microcomputer) 50 (see FIG. 7). The outer shape of the cross section of the left shade 21, as shown in FIGS. 4 and FIG. 5 (a), the one circumferential position of the circle C is divided in the circumferential direction 8, etc. of the radius R (P ₀ ~P _7), P ₃ ,
Located in P ₆ position only on a circle C, the region of toward the position shown by P ₁ to P ₃ from the position shown by symbol P ₀ is larger than the outer shape of the circle C, also areas of over the P ₃ to P ₆ position Yen C
It is formed in an unusual circle smaller than the outer shape of. The rotation center O (horizontal support shaft 23) of the shade 21 is the shade 2
1 and the optical axis L of the headlamp.
The rotation center O (horizontal support shaft 23) of the shade 21 is located at a position R below the center. When Accordingly shade 21 is rotated, the oncoming vehicle side of the clear-cut line CL ₁ in the light distribution pattern becomes highest position than the horizontal line H (Fig. 6
6 (e) and (f)) (see FIG. 6)
(See (a), (b) and (c)).

On the other hand, the outer shape of the cross section of the right shade 22
Is, as shown in FIG. 4 and FIG.
Circumferential position (P₀~ P₇)of
Of which, P_Two~ P_Four, P₆~ P₀The area indicated by is placed on the circle C
And the symbol P₀~ P _TwoArea and P_Four
~ P₆The area indicated by is chamfered radially inward
It is formed in a circle. Also, the rotation center O of the shade 22
(The horizontal support shaft 23) coincides with the center of gravity of the shade 22
The optical axis of the light reflected by the reflector 14 (head run)
Center of rotation of the shade 22 at a position R below the optical axis of L)
O (horizontal support shaft 23) is located. Shade for this
When the pivot 22 rotates, the preceding vehicle in the light distribution pattern is closed.
Rear cut line CL_TwoIs higher than the horizontal line H
(See FIGS. 6B and 6F).
Positions corresponding to the horizontal line H (FIGS. 6 (a), (c),
(See (d) and (e)).

The left shade 21 and the right shade 22
Is a single aluminum die-cast shade 20
And the position P at 45 degree intervals in the circumferential direction₀
~ P _FiveAre positioned directly above the shade rotation center O
When it comes, the clear cut line CL of the light distribution pattern
Are shown in FIGS. 6A to 6F. That is, FIG.
(A) is the P of the shade 20₀Position is directly above the rotation center O
When the vehicle comes to
This is the reference pattern used when FIG. 6 (b)
Shade 20 P₁When the position is directly above the rotation center O
If the preceding vehicle does not exist and there is an oncoming vehicle,
It is a pattern in the case. FIG. 6C shows the shade 20.
P_TwoPattern when the position is right above the rotation center O
Thus, the reference pattern similar to the pattern shown in FIG.
is there. FIG. 6D shows the P of the shade 20._ThreePosition is rotating
The pattern when it is right above the heart O.
When there is a car but the oncoming car is far away,
It is. FIG. 6E shows the P of the shade 20._Fourthe position is
This is the pattern when it is just above the center of rotation O.
Only the clear cut line is above the horizontal line H,
Pattern when there is a preceding vehicle but no oncoming vehicle
It is. FIG. 6F shows the P of the shade 20._Fivethe position is
This is the pattern when it is right above the rotation center O.
And the clear cut line of the preceding vehicle is above the horizontal line H
When there are no oncoming and preceding vehicles,
Pattern. Note that the symbol R in FIG.₁Is a she
2 shows the horizontal position of the rotation center O of the card 20.

FIG. 7 shows the overall configuration of the shade rotation control device. The automobile is provided with a laser radar S which is an inter-vehicle distance measuring sensor for measuring an inter-vehicle distance with a preceding vehicle (an oncoming vehicle and a preceding vehicle).
Is output to a control unit (microcomputer) 50 which is a shade rotation control device. The control unit 50 differentiates the distance information sequentially sent from the laser radar S with respect to time. For example, if the differentiated value is equal to or more than a predetermined value, the preceding vehicle is an oncoming vehicle, and if As a preceding vehicle, it is determined whether the preceding vehicle is an oncoming vehicle or a preceding vehicle.

The control unit 50 also includes a shade rotation position (shade rotation for forming a pattern corresponding to FIGS. 6A to 6F) which is an optimum clear cut line according to the presence or absence of an oncoming vehicle and a preceding vehicle. Is stored as table data, the distance information (inter-vehicle distance) provided from the laser radar S, the rotation angle detector 40 (40R for the right-side headlamp shade rotation angle detector, 40R for the left headlamp) Shade rotation angle detector is 40L)
And the current rotation angle position information θ ₀ (θ ₀ R, θ ₀ L) of the shade 20 obtained from the
The required rotation amount (Δθ = θ−θ ₀ ) of the shade 20 is calculated based on the table data relating to the optimum rotation position θ of 0, and the motor drive circuit 51 is set so that the shade 20 is at the optimum rotation position θ. Output, which allows the shade 20
(The respective shades 20 in the left and right headlamps) are rotated, and the clear cut line does not cause glare to the eyes of the driver of the preceding vehicle (oncoming vehicle and preceding vehicle), and the driver of the own vehicle has visibility. The position is adjusted to an optimal position (one of FIGS. 6A to 6F) that becomes favorable.

Reference numeral 45 denotes a switch for fixing the shade at a shade rotation position where the clear cut line is located at the uppermost position in order to improve visibility in a distant place.
This is effective when there is no oncoming vehicle or preceding vehicle at the front. Further, the rotation of the shade 20 (switching of the clear cut line) may be performed manually,
With 0, automatic switching and manual switching based on the inter-vehicle distance information from the laser radar S can be selected.

In the first embodiment, the left shade 21 and the right shade 22 are integrated as an aluminum die-cast shade 20, but the separately molded left shade 21 and right shade 22 are welded. It may be integrated by bonding, bonding, bolt and nut fastening, or other joining means. In the embodiment described above, the shade 21 for specifying the clear cut line is used.
(22) Although the upper positions P _{0 to} P ₅ are provided at intervals of 45 degrees in the circumferential direction, the specific position of the clear cut line is
It is also possible to finely dispose them at an interval of 30 degrees or 30 degrees, and control them by more clear cut line patterns.

[0023]

As is apparent from the above description, according to the projection type vehicle headlamp of the present invention, the shade area for forming the front vehicle side clear cut line and the shade area for forming the oncoming vehicle side clear cut line are formed. A very simple structure that adjusts the rotation of a single shade, each of which has a circular cross section with a predetermined circular shape, about the rotation center axis, making it the optimal clear cut line according to the presence or absence of a preceding vehicle and an oncoming vehicle. Can be formed. Also, the top edge of the shade that contributes to the formation of the clear cut line changes in the vertical direction but hardly changes in the optical axis direction, so the clear cut line of the light distribution pattern continues in the vertical direction while maintaining sharpness Thus, the clear cut line suitable for the running condition can always be obtained without the disadvantage that the clear cut line suddenly changes or the clear cut line becomes inappropriate in a transitional transition situation. According to the second aspect, since the center of rotation of the shade substantially coincides with the center of gravity of the shade, the (inertia) weight of the shade does not act on the shade rotating mechanism as torque around the rotation center axis. , Smooth and proper rotation of the shade is guaranteed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the internal structure of an automobile headlamp according to one embodiment of the present invention.

FIG. 2 is a left-right vertical sectional view of a shade provided on the headlamp (a view from the front side of the headlamp).

FIG. 3 is a perspective view of a light distribution pattern created by a shade and a headlamp from the driver side of the boarding;

FIG. 4 is a side view of a shade.

FIG. 5A is a diagram showing an outer shape of a left shade. FIG. 5B is a diagram showing an outer shape of a right shade.

FIG. 6 is a diagram showing a change of a clear cut line of a light distribution pattern formed by the headlamp.

FIG. 7 is a configuration diagram of a control device that controls rotation of a shade.

FIG. 8 is a perspective view showing the internal structure of a headlamp according to a first prior art.

FIG. 9 is a perspective view showing the internal structure of a headlamp according to a second prior art.

FIG. 10 is a side view of a light distribution control shade.

[Explanation of symbols]

10 is an optical projection unit 12 light source bulb 14 reflector 16 projection lens 18 lens holder 20 first focal point F ₂ reflector rotational center F ₁ reflector shade 21 left shade 22 right shade 23 horizontal support shaft O shade light distribution control the second focal point M ₁ drive motor

Continuation of front page (56) References JP-A-5-342901 (JP, A) JP-A-6-139802 (JP, A) JP-A-6-267304 (JP, A) JP-A-7-29403 (JP) , A) JP 6-43906 (JP, U) JP 6-15205 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F21S 8/12 F21S 8/10 F21V 11/00 F21V 13/00

Claims (2)

(57) [Claims] 1. A reflector having a substantially ellipsoidal shape, a light source disposed at a first focal point of the reflector, a projection lens disposed in front of the reflector, and a projection lens located near a second focal point of the reflector. And a cylindrical shade for forming a front vehicle-side clear cut line and a cylindrical shade for forming an oncoming vehicle-side clear cut line which are horizontally disposed across the reflector at substantially the focal point of the vehicle. In a projection type automotive headlamp in which a clear cut line of a light distribution pattern is adjusted up and down by rotating about a dynamic center axis, the shades are integrated, and the outer shape of the cross section of each shade is A headlamp for a projection-type vehicle, wherein the predetermined distance from the center of movement is a circular shape that is different in a circumferential direction. 2. The projection type headlamp according to claim 1, wherein the center of rotation of the shade substantially coincides with the center of gravity of the cross section of the shade.