JP2663312B2 - Headlights for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a headlamp in which the shape of a reflecting mirror is formed asymmetrically to the left and right with respect to a vertical plane including its optical axis in accordance with streamlining of a vehicle. An object of the present invention is to provide a novel vehicle headlight device capable of obtaining a light pattern.

[0002]

2. Description of the Related Art In recent years, streamlining has been demanded from the viewpoint of aerodynamics with respect to the shape of a vehicle body.

[0003] With this tendency, the planar shape of the front nose b of the automobile a becomes curved from the center to the side edges as shown in FIG. 11, and the degree of curvature tends to increase.

A headlight c_ provided in such a vehicle
Regarding R and c_L, the reflection surfaces are not symmetrical with respect to a reference surface extending in the vertical direction through the center line in the front-rear direction of the vehicle.

[0005] In Fig. 12, (a) is a reflector d_ related to a headlight c_R located on the right side as viewed from the back of the vehicle.
R shows the front shape, and (b) shows the front shape of the reflector d_L for the headlight c_L located on the left side when viewed from the back of the vehicle.

The reflecting surfaces of these reflecting mirrors d_R and d_L are both paraboloids of revolution, and their optical axes extend in the front-rear direction through the centers of the bulb mounting holes e_R and e_L.

[0007] As shown in the figure, the reflecting mirror d_R occupies a larger area in the reflecting area located on the right side with respect to the vertical axis passing through the center of the bulb mounting hole e_R than in the reflecting area located on the left side. The other reflecting mirror d_L occupies a larger area in the reflecting area located on the left side with respect to the vertical axis passing through the center of the bulb mounting hole e_L than in the reflecting area located on the right side.

The reflecting area of the reflecting mirror d_R has a horizontal axis extending rightward through the center of the bulb mounting hole e_R, and a diagonally lower right side passing through the center of the bulb mounting hole e_R at a predetermined angle with respect to the horizontal axis. Is divided into two parts by
The area AR located above both axes contributes to the formation of a light distribution pattern related to the passing beam.

On the other hand, the reflecting area of the reflecting mirror d_L has a horizontal axis extending rightward through the center of the bulb mounting hole e_L, and a diagonally lower right side passing through the center of the bulb mounting hole e_L at a predetermined angle with respect to the horizontal axis. Is divided into two parts by
The area AL located above both axes contributes to the formation of a light distribution pattern related to the passing beam.

[0010] At this time, in forming the passing beam, the central axis of the filament is arranged along the optical axis of each reflecting mirror, and a shade is provided therebelow so as to reach the area other than the reflecting areas AR and AL. A light source (for example, an H4 bulb or the like) configured to cut the irradiation light is used.

[0011]

However, due to the left-right asymmetry of the reflecting surface described above, the headlight c_R
And c_L, there is a problem that the light distribution pattern of the passing beam is mismatched.

FIG. 11 schematically shows a light distribution pattern by headlights c_R and c_L. In the figure, the line “HH” indicates a horizontal line, and the line “VV” indicates a vertical line.

As can be seen from the figure, the light distribution pattern p_L by the headlamp c_L is formed such that the left portion of the vertical line VV is superior in area to the right portion, and the light distribution pattern p_R by the headlight c_R. On the contrary, the right side portion of the vertical line VV is formed to be superior in area compared to the left side portion. This is because the correspondence between the left and right of the reflection surface and the left and right of the light distribution pattern is reversed at the time of projection.

Since the overall pattern is formed as a combination of such different light distribution patterns, the light distribution does not conform to the standard, or the visibility is disadvantageous. Incidentally, such inconvenience can be solved by designing a lens step formed on the outer lens covering the front surface of the reflecting mirror, but when the so-called slant nose progresses with the streamlining of the vehicle body,
Accordingly, the angle formed with respect to the vertical axis of the outer lens (so-called slant angle) is so tight that it is not possible to rely on the light distribution control function of the outer lens. Can not.

[0015]

According to the vehicle headlight device of the present invention, in order to solve the above-mentioned problem, a reflecting mirror provided on one of the lamps has a reflecting surface in a vertical plane including an optical axis. By the reflection area located on the left side when viewed from the back of the vehicle when divided, the light distribution pattern mainly forms a pattern located on the left side with respect to the vertical axis, and on the other hand, on the right side of the vertical plane when viewed from the back of the vehicle Depending on the reflective area
The light distribution pattern mainly includes a pattern located on the right side with respect to the vertical axis.

Further, regarding the reflector provided on the other lamp, the reflection area located on the left side when viewed from the back of the vehicle when the reflection surface is divided into two by a vertical plane including the optical axis, is included in the light distribution pattern. The pattern located mainly on the right side with respect to the vertical axis is mainly formed, while the reflection area located on the right side of the vertical plane when viewed from the rear of the vehicle mainly forms the pattern located on the left side with respect to the vertical axis in the light distribution pattern.

In each of the reflecting mirrors of the two lamps, when the reflecting surface is divided into two by the vertical plane including the optical axis, the reflecting region having the larger area has the cut line inclined with respect to the horizontal plane. The reflection area having the smaller area contributes to the formation of the cut line extending in the horizontal direction.

[0018]

According to the present invention, the shape of the reflectors of the headlights provided on the left and right sides of the front portion of the vehicle is asymmetrical with respect to the vertical plane including these optical axes.
There is no significant difference between the light distribution patterns of each headlamp.
This is because in the reflector provided for one headlight,
When the reflecting surface is divided into two by the vertical plane including the optical axis, the light distribution pattern is obtained as a result of the light reflected on each reflecting surface intersecting with respect to the optical axis, whereas the reflection provided on the other headlight is provided. In the mirror, when the reflecting surface is divided into two by the vertical plane including the optical axis, the light distribution pattern can be obtained without the light reflected on each reflecting surface intersecting with the optical axis. Regarding any of the reflectors, the reflection area having a larger area with respect to the vertical plane including the optical axis forms a cut line inclined with respect to a horizontal plane, and the reflection area having a smaller area has a cut line extending in a horizontal direction. Is formed.

[0019]

FIG. 1 is a diagram schematically showing the configuration of a vehicle headlight device 1 according to the present invention.

The vehicle headlight device 1 includes a headlight 2R disposed on the right side and a headlight 2L disposed on the left side when viewed from the back of the vehicle.

The reflector 3L of the headlight 2L has a paraboloid of revolution like the reflector d_L described above.

That is, the reflecting mirror 3L has its optical axis extending in the front-rear direction of the vehicle through the center of the bulb mounting hole 4L.

As shown in FIG. 2, the reflection surface 5L is larger in the reflection area 5LA located on the left side when viewed from the front with respect to the vertical axis passing through the center of the bulb mounting hole 4L than in the reflection area 5LB located on the right side. Occupies the area. The reflecting surface 5L is defined by a horizontal axis extending rightward through the center of the bulb mounting hole 4L and an axis passing the center of the bulb mounting hole 4L and extending obliquely downward to the left at a predetermined angle with respect to the horizontal axis.
When divided, the region 5LH located above both axes contributes to the formation of a light distribution pattern related to the passing beam.

Reference numeral 6L denotes a passing beam filament, the center axis of which is arranged along the optical axis KK of the reflecting mirror 3L as shown in FIG. Immediately below the filament 6L, a shade 7 is provided so as to cut off light emitted from the filament 6L to an area other than the reflection surface 5LH.
Is provided. An example of such a filament structure is a subfilament of an H4 bulb.

On the other hand, the reflecting mirror 3R of the right headlight 2R is
An elliptical paraboloid is used as a basic surface, and a new degree of freedom is given to the basic surface to provide a reflecting surface 5R that can freely design a curved shape deviating from the basic surface. The reflecting mirror already proposed in Japanese Patent Application No. Hei 3-21430 is used.

That is, the basic surface of the reflecting surface 5R has an elliptical cross section when cut by a plane perpendicular to the optical axis, and an ellipse whose cross section when cut by a plane including the optical axis has a parabolic shape. It is a parabolic surface. Then, the shape of the cross-sectional curve when the reflecting surface is cut by a plane orthogonal to the optical axis is represented by a finite-order vector algebraic expression by specifying the start point position, the end point position, and the coefficient vector between the two points. By modifying the surface, the reflection surface can have a light distribution control function.

FIG. 4 is a front view showing an example of the reflection surface 5R.
In FIG. 4, the axis is perpendicular to the plane of the drawing. ), Six regions 5R1, 5R2,
It is divided into 5R3, 5R4, 5R5, and 5R6. That is, the three planes are an xy plane including an axis extending in the horizontal direction passing through the center of the bulb mounting hole 4R (this is referred to as “y axis”) and the x axis, and a predetermined plane with respect to the plane. , And an xz plane including an axis extending in the vertical direction passing through the center of the bulb mounting hole 4R (hereinafter referred to as “z axis”) and an x axis. .

The center of the bulb mounting hole 4R formed at a position deviated to the right (as viewed from the back) from the center of the reflecting surface 5R is selected as the origin O of the coordinate system xyz. I have.

As can be seen from the figure, when the reflecting mirror 3R is viewed from the front, a reflecting area 5RA located on the right side with respect to the z-axis.
(5R1, 5R2, 5R6) occupies a larger area than the reflection area 5RB (5R3, 5R4, 5R5) located on the left side.

Further, the filament 6 for the passing beam is used.
As shown in FIG. 5, R has its central axis arranged along the optical axis of the reflecting mirror 3R. However, in this case, the shade as in the case of the headlight 2L is not required. This is because a cut line peculiar to the passing beam can be formed by the light distribution control function of the reflecting mirror.

The regions 5R1, 5R4 are respectively located above and below the xy plane, 5R1 belongs to the region 5RA, and 5R4 belongs to the region 5RB. These regions are cut lines (or cutoffs) in the light distribution pattern.
To contribute. In other words, the region 5R1 is located immediately above the xy plane in the second quadrant (y <0, z> 0) of the yz plane, and the horizontal line H- as shown in the light distribution pattern 8R1 of FIG. A cut line CL1 having a predetermined cut line angle with respect to H is formed.

The region 5R4 is located immediately below the xy plane in the fourth quadrant (y> 0, z <0) of the yz plane, and its light distribution pattern 8R4 is a horizontal line HH. Cut line CL extending immediately below and parallel to the horizontal line
4 is formed.

The region excluding 5R1 in the upper half surface (region where z> 0) of the reflection surface 5R is divided into two regions 5R2 and 5R3 by the xz plane. right side (y <
0) Light distribution pattern 8R2 obtained by region 5R2
Is below the horizontal line HH as shown in FIG.
The pattern is located substantially on the left side with respect to V. Also,
The light distribution pattern 8R3 obtained by the region 5R3 on the left side (y> 0) with respect to the z axis has a horizontal line H as shown in FIG.
The pattern is located on the right side of the vertical line VV below −H.

In the lower half of the reflecting surface 5R (region where z <0), the region except for 5R4 is 2 x by the xz plane.
Area 5R5, 5R6. That is, the light distribution pattern 8R5 obtained by the region 5R5 on the left side (y> 0) with respect to the z-axis is substantially 1/1, which is located below the horizontal line HH and almost on the right side with respect to the vertical line VV as shown in FIG. It becomes a four-circle pattern.

The light distribution pattern 8R6 obtained by the region 5R6 on the right side (y <0) with respect to the z axis is located below the horizontal line HH and almost on the left side with respect to the vertical line VV as shown in FIG. The pattern is a substantially １ ／ elliptical horizontally long pattern.

The above patterns are combined to form an overall pattern 8R relating to the passing beam. That is,
Most of the light distribution pattern having a clear cut line CL is created by the light distribution control function of the reflection surface 5R. Note that the cut line CL has a cut line CL1 inclined at a predetermined angle with respect to the horizontal line HH,
A cut line CL4 extends in the horizontal direction immediately below the horizontal line HH.

Each of these reflection regions has an elliptical paraboloid as a basic surface, and a shape deviating from the basic surface is obtained by adjusting a shape parameter in each region or performing a curved surface operation by vector control. Surface (hereinafter, referred to as a "free-form surface") with a high degree of freedom,
Basically, the following operations are performed.

(1) By adjusting the shape parameters,
Collect the filament image below the cut line.

The basic elliptical paraboloid is the above-mentioned x−
In a yz rectangular coordinate system, the focal length is f, the y axis is
It can be expressed by Equation 1 using two parameters α _y and α _z that define the shape of the ellipse in the z-axis direction.

[0040]

(Equation 1)

In order to direct the reflected light obliquely downward and forward with respect to the horizontal plane, the value of the parameter α _z may be changed.

This is easy considering that the variable operation of the parameter α _z is equivalent to the operation on the focal length of the cross-sectional shape (parabola) when the elliptical paraboloid is cut along the xy plane. Will be understood.

According to the same concept, it is understood that the horizontal spread of the reflected light can be freely changed by changing the value of α _y .

(2) By imposing an orthogonal condition on the tangent vector at the end point, an operation is performed such that the central axis in the longitudinal direction of the filament image is arranged with an orientation parallel to the cut line.

The cross-sectional shape of the free-form surface when cut along a plane including the optical axis is expressed by a quadratic equation, and the cross-sectional shape when cut perpendicular to the optical axis is generally expressed by an N-order equation. Is defined as such a curved surface.

For simplicity, it is assumed that N = 3, two parameters (t and u) and coefficient vectors a ₀ , a ₁ , a ₂ , a ₃
Is used, a vector function representing a free-form surface is expressed as F (u,
When t), the equation of the curved surface can be expressed as the following equation.

[0047]

(Equation 2)

The vector i in the equation (2) is a unit vector in the x-axis direction.

The parameter t is a radial radius around the x-axis, and a value obtained by multiplying the vector function f (u) of the parameter u by t represents a cross-sectional curve when the curved surface is cut perpendicular to the x-axis.

The coefficient vectors a ₀ , a ₁ , a ₂ , and a ₃ are obtained from position vectors and tangent vectors at the start and end points of the cross-sectional curve. Note that such a curve is represented by "F
ergoson curve ".

Now, as shown in the yz diagram of FIG.
(1), each tangent vector V (1), P (2) at P (2)
In (2), the curve 9 is constrained so as to be orthogonal to the direction vectors t1 and t2 directed from the origin O to the end points P (1) and P (2), respectively, and an operation is performed on the curved surface shape.

FIG. 8 shows the geometrical optical action of this operation. Reference numerals 10, 10,... Indicate filament images projected on a distant screen after light emitted from the filament is reflected at different reflection points when the filament is assumed to be cylindrical. It can be clearly understood that in these rectangular filament images 10, 10,..., All the central axes extending in the longitudinal direction coincide.

In the figure, "UP-LW" indicates a relative vertical axis for each filament image, and "LH-RH"
Indicates a relative horizontal line orthogonal to this. this
The reason for imposing such orthogonal conditions is that there are no restrictions
An ellipsoidal paraboloid that is not
FIG. 13 shows the arrangement tendency of the lament image.
The center axis extending in the longitudinal direction of each filament image is not
Because they are aligned, the longitudinal direction of each filament image
This is because it becomes difficult to align the side edges in the.

(3) An operation is performed by applying a twist to the curved surface so that the central axes in the longitudinal direction of the filament images are aligned with each other.

As shown in the yz diagram of FIG.
= T ² ₀ / 4f When the intersection line 11 is cut by a plane of x = t ² ₁ / 4f using a vector function f ₀ to represent the intersection line 11 as expressed by the following equation (3). Is represented by the following equation (4) using the vector function f ₁ .

[0056]

(Equation 3)

[0057]

(Equation 4)

The vector function f ₀ is obtained by calculating the coordinate values of the end points P ₀ (1) and P ₀ (2) of the intersection line 11 and the tangent vectors V ₀ (1) and V ₀ (2) at the two points. And the vector function f ₁ is defined by the end points P ₁ (1), P ₁
(2) Coordinate values and respective tangent vectors V ₁ at both points
(1), defined by V ₁ (2).

In order to add a torsion to a curved surface, for example, an equation of the curved surface may be established by linearly combining the vector functions f ₀ and f ₁ as shown in Expression 5.

[0060]

(Equation 5)

FIG. 10 illustrates the geometrical optical action of this operation. It can be seen that the filament images 13, 13,... Projected on the distant screen are arranged such that all the upper edges in the longitudinal direction coincide.

The above-described curved surface operations (2) and (3) are performed on the reflection area that contributes to the formation of the cut line. That is, the cut line CL1 formed by the region 5R1 and the cut line C formed by the region 5R4
L4 is based on such an operation.

FIG. 1 shows a light distribution pattern finally obtained through the respective outer lenses (shown by broken lines in FIG. 1) of the headlights 2R and 2L.

That is, with respect to the light distribution pattern 14L obtained by the left headlight 2L, the reflection area 5LB of the reflection surface 5L mainly contributes to the formation of the light distribution pattern located on the right side of the vertical axis VV. The reflection area 5LA mainly contributes to the formation of the light distribution pattern located on the left side of the vertical axis VV. That is, when the reflecting surface is divided into two parts by a vertical plane including the optical axis, the light reflected by each of the reflecting regions intersects with each other with respect to the optical axis.

Then, in the light distribution pattern 14L,
The left side portion of the vertical line V-V is formed to have an area superior to the right side portion.

On the other hand, with respect to the light distribution pattern 14R obtained by the right headlight 2R, the reflection area 5RA (5R1, 5R2, 5R6) of the reflection surface 5R corresponds to the vertical line VR.
−V mainly contributes to the formation of the light distribution pattern located on the left side of the -V, and the reflection region 5RB (5R3, 5R4, 5R5)
It mainly contributes to the formation of the light distribution pattern located on the right side of the vertical axis V-V. In other words, in this case, when the reflecting surface is bisected by a vertical plane including the optical axis, the light reflected by each reflecting region does not intersect with each other with respect to the optical axis.

Then, in the light distribution pattern 14R,
The shape parameter α _y is variably set by the above-described operation (1) so that the left side portion of the vertical line VV is formed to be superior in area to the right side portion.

Therefore, in the headlight 2R, the pattern shape can be adjusted to the same shape as the light distribution pattern 14L of the headlight 2L by adjusting the horizontal spread of the light distribution pattern.

What can be said in common for both reflecting mirrors is that
Reflection region 5R having a larger area with respect to vertical line VV
A, 5LA, a cut line inclined with respect to the horizontal line HH is formed, and the reflection area 5R having the smaller area is formed.
B, 5LB means that a horizontally extending cut line is formed.

The two patterns obtained in this way have high matching with each other, and the combination of these becomes the final light distribution pattern.

Therefore, the light distribution patterns of the left and right headlights become irregular, and the luminous intensity distribution does not conform to the standard,
Inconveniences such as reduced visibility are eliminated.

[0072]

As is apparent from the above description, according to the present invention, the shape of the light distribution pattern between the left and right headlights is significantly different, and the unintended light distribution and There is no such thing as becoming.

The above-described embodiment is merely an embodiment of the present invention, and the technical scope of the present invention should not be construed as being narrow only by this embodiment. For example, in the example above,
Of the two reflecting mirrors, one reflecting mirror has a free-form reflecting surface and the other reflecting mirror has a rotating parabolic reflecting surface. However, the present invention is not limited to this. about,
The reflection surface may be formed as a free-form surface (however, light reflected by left and right reflection regions intersects with respect to a vertical plane including the optical axis).

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a relationship between respective headlights constituting a vehicle headlight device according to the present invention and respective light distribution patterns.

FIG. 2 is a front view of a rotating parabolic reflector provided in one headlight according to the present invention.

FIG. 3 is a perspective view showing a positional relationship between a reflecting mirror and a filament in FIG. 2;

FIG. 4 is a front view for explaining a light distribution control section of a reflector provided in the other headlight according to the present invention.

FIG. 5 is a perspective view showing an arrangement of filaments and a projection pattern for the reflecting mirror of FIG. 4;

6 is a diagram showing an entire light distribution pattern obtained by the reflecting mirror of FIG.

FIG. 7 is a yz diagram illustrating orthogonal conditions imposed on tangent vectors.

FIG. 8 is a diagram showing an arrangement of filament images for explaining a geometrical optical effect when a tangent vector is constrained by orthogonal conditions.

FIG. 9 is a yz diagram for describing an operation of giving a twist to a curved surface.

FIG. 10 is a diagram showing an arrangement of filament images for explaining a geometrical optical effect of an operation of applying a twist to a curved surface.

FIG. 11 is a diagram schematically showing a relationship between respective headlights constituting a conventional vehicle headlight device and respective light distribution patterns.

12A is a front view showing a headlight reflector disposed on the right side of the front of the vehicle as viewed from behind the vehicle, and FIG. 12B is a front view of the headlight disposed on the left side of the front of the vehicle. It is a front view which shows a reflecting mirror.

FIG. 13 Projected by an elliptical parabolic surface
FIG. 4 is a diagram showing an example of the arrangement of filament images.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle headlamp apparatus 2R First lamp 2L Second lamp 3R Reflector (of first lamp) 3L Reflector (of second lamp) 5R Reflector (of first lamp) 5L (first lamp) 2 Reflector surface 6R Filament 9 Cross-sectional curve 10 Filament image 11, 12 Cross-sectional curve 13 Filament image 14R Light distribution pattern (for first lamp) 14L Light distribution pattern (for second lamp) CL Cut line CL1 Incline Cut line CL4 Cut line extending in the horizontal direction

Claims (2)

(57) [Claims] 1. A vehicle headlight device comprising a pair of lamps provided at a front portion of a vehicle for irradiating a low beam, wherein (a) the shape of a reflecting mirror constituting each lamp is the light (2) Regarding the reflecting mirror provided in the first lamp,
When the reflecting surface is divided into two by the vertical plane including the optical axis,
The reflection area located on the left side of the vertical plane when viewed from the back of the vehicle mainly contributes to the formation of the pattern located on the left side with respect to the vertical axis in the light distribution pattern formed by the total reflection surface, and on the other hand, from the back of the vehicle The reflection region located on the right side of the vertical plane when viewed, mainly contributes to the formation of the pattern located on the right side with respect to the vertical axis in the light distribution pattern,
(C) With respect to the reflecting mirror provided in the second lamp, when the reflecting surface is divided into two parts by the vertical plane including the optical axis, the reflecting area located on the left side of the vertical plane when viewed from the back of the vehicle is entirely The light distribution pattern formed by the reflection surface mainly contributes to the formation of the pattern located on the right side with respect to the vertical axis, while the reflection area located on the right side of the vertical plane when viewed from the back of the vehicle is one of the light distribution patterns. Mainly contributing to the formation of the pattern located on the left side with respect to the vertical axis,
(D) Regarding the reflecting mirrors provided in the first and second lamps, when the reflecting surface is divided into two by a vertical plane including the optical axis, the reflecting area having the larger area is positioned with respect to the horizontal plane. A headlamp device for a vehicle, characterized in that the reflection region having a smaller area contributes to the formation of a cut line extending in the horizontal direction. 2. The vehicle headlight device according to claim 1, wherein the reflector of the first lamp has an elliptical cross-sectional shape whose basic surface is cut by a plane perpendicular to the optical axis. And the cross section taken along a plane including the optical axis is a parabolic elliptical paraboloid, and the central axis of the filament is arranged along the optical axis. The length of the major axis or minor axis is specified for the shape of the ellipse that is the cross-sectional curve when the surface is cut by a plane perpendicular to the optical axis.
The horizontal or vertical direction of the light distribution pattern
The spread is defined, (c) reflecting surface, cross-sectional curve when cut along a plane perpendicular to this optical axis N the following formula (N is an integer) is represented by, perpendicular to the primary surface to the optical axis The end of the section curve when cut in a plane
By specifying a point and a coefficient vector of Nth order,
The shape of the profile curve is defined, with respect to cross-sectional curve of the reflecting surface of the (d) (iii), for the profile curve belonging to the reflective region involved in the formation of the cut line, the position of the tangent vector end point at the end point Vector
By defining the coefficient vector to be orthogonal to
Therefore, the longitudinal direction of each filament image projected forward
The central axes coincide, the coefficient of (e) Further to the profile curve of the (d) (iii) Baie
By twisting the surface according to the
The longitudinal direction of each filament image projected forward.
Match the side edges with each other and collect these side edges to cut
A headlight device for a vehicle , wherein a line is formed .