JPH0643906U - Projection type automobile headlamp - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a projection-type automobile headlamp capable of smoothly switching the cut line in the vertical direction. [Structure] A reflector 14 having a substantially ellipsoidal shape, and a light source 12 disposed at a substantially first focus F ₁ of the reflector 14,
A projection lens 16 arranged in front of the reflector 14.
And a shade 20 for controlling light distribution, which is arranged near the second focal point of the reflector and at a substantially focal position of the projection lens, and blocks a part of the light reflected by the reflector 14 and directed to the projection lens 16. The shade 20 is formed in a shape in which the distance from the rotation center to the rotation tip portion gradually changes in the circumferential direction, and rotates around a horizontal support shaft 23 that is a rotation center eccentric to the center of gravity G of the shade. With the structure described above, the shade 20 is rotated about the horizontal support shaft 23 to vertically displace the shade apex position to control the light distribution. The shade 20 has a center of gravity of the shade. Balance weight 3 to match the center of rotation
1, 32 are provided so that the shade 20 can be smoothly rotated.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a projection type headlamp in which light reflected from a substantially ellipsoidal reflector is projected forward by a projection lens, and in particular, a projection type automotive head capable of switching light distribution by tilting a shade. Regarding the lamp.

[0002]

[Prior art]

As conventional techniques for this type of headlamp, there are Japanese Utility Model Laid-Open No. 63-41801 and Japanese Patent Laid-Open No. 1-213901. In the former, as shown in FIG. 8, a light source 3 is provided at a first focus F ₁ of a reflector 2 having a substantially ellipsoidal shape, and a shade 4 is provided at a second focus F ₂ , and a projection lens is provided in front of the shade 4. In the projection type headlamp provided with 5, the shade 4 is tilted about the horizontal support shaft 7 so that a part of the light directed to the projection lens 5 is blocked by the shade 4, and the light distribution for the sub beam and the main beam It has a structure that switches the light distribution. Reference numeral 1 is a lamp body, and reference numeral 6 is a front lens.

In the latter, although not shown, the shade tilting means is different from the former, but the configuration in which the shade is tilted to switch between the sub-beam light distribution and the main-beam light distribution is the same.

[0004]

[Problems to be solved by the device]

 In the above-mentioned conventional technique, it is possible to switch between the sub beam and the main beam in two steps, but it is not possible to form a light distribution pattern between the sub beam and the main beam, for example. In other words, at high speeds, the higher the speed, the better the visibility for the driver when the light distribution pattern of the headlamp is closer to the light distribution pattern of the main beam. However, it is dazzling for oncoming vehicles. Therefore, it is very convenient to have a light distribution pattern between the main beam and the sub beam that has good visibility and that does not cause glare for oncoming vehicles until they approach each other to some extent. However, with the conventional technology, it is possible to form a sub-beam that illuminates the front side of the vehicle widely left and right and a main beam that illuminates a distant, rather narrow area with one lamp, but other light distributions are possible. There has been a demand for a headlamp that cannot be formed and can also form a light distribution other than the main beam and the sub beam by one lamp.

Therefore, the applicant has proposed Japanese Utility Model Laid-Open No. 3-81705 in order to solve the above problems. As shown in FIG. 9, a horizontal support shaft 7 is provided at a position eccentric with respect to the central axis ◯ of the cylindrical body 4 which is a shade, and the cylindrical body 4 which is a shade is rotated around the eccentric horizontal support shaft 7. By moving it, the vertex position of the shade 4 is vertically displaced and the cut line of the light distribution pattern is changed steplessly.

However, in the above-mentioned prior art (Actual Kaihei 3-81705), since the horizontal flat shaft 7 which is the center of rotation is eccentric with respect to the center of gravity G of the cylindrical body 4 which is a shade, the center of rotation is also cylindrical. It is out of the center of gravity of the body. Therefore, there is a problem that the load acting on the motor, which is the rotating means, differs depending on the rotating position of the cylindrical body, and smooth rotation of the shade, that is, smooth switching of the light distribution pattern is impeded. The vibration of the engine is transmitted to the cylindrical body 4 which is a shade through the horizontal support shaft 7, but is transmitted because the horizontal support shaft 7 which supports the cylindrical body which is a shade does not coincide with the center of gravity. There was also the problem that the load due to the torsional torque acting on the horizontal support shaft due to vibration was large.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a projection-type automobile headlamp capable of smoothly switching the cut line in the vertical direction steplessly.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, in a projection type automobile headlamp according to the present invention, a reflector having a substantially ellipsoidal shape, a light source disposed at a substantially first focus of the reflector, and a light source disposed in front of the reflector. The projection lens and the light distribution control for blocking a part of the light that is reflected by the reflector and is directed to the projection lens, which is disposed near the second focus of the reflector and at the substantially focus position of the projection lens. The shade is formed in a shape in which the distance from the rotation center to the rotation tip gradually changes in the circumferential direction, and is a horizontal support shaft that is a rotation center eccentric to the center of gravity of the shade. A projection type automotive headlamp that is configured to rotate around and that controls the light distribution by rotating the shade about a horizontal support shaft and vertically displacing the shade apex position. Is obtained so as to provide a balance weight for matching the center of gravity of de the center of rotation of the shade.

[0009]

[Action]

 When the shade is rotated around the horizontal support axis, the height of the vertex of the shade changes, so the light distribution pattern (clear cut line) changes vertically. In addition, since the center of gravity of the shade and the center of rotation of the shade coincide with each other due to the weight balance, the rotation of the shade is smooth, and the torsion torque that acts on the horizontal support shaft that is the shade support part due to the vibration transmitted to the shade The load is also reduced.

[0010]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 5 are projection type automobile headlamps according to an embodiment of the present invention, showing a headlamp for right-side light distribution in Europe and the United States, and FIG. 1 is a perspective view showing an internal structure of the headlamp. 2 is a left-right vertical cross-sectional view of the shade provided in the headlamp, FIG. 3 is a perspective view of the shade and the light distribution pattern created by the headlamp from the driver's side, and FIG. 4 shows the shape of the shade. FIG. 5 is a diagram for explaining (a view of the shade from the right side of FIG. 1), FIG. 5 is a diagram showing a change of a clear cut line of a light distribution pattern formed by the headlamp, and FIG. 6 is a diagram of a shade drive control mechanism. It is a block diagram.

In these figures, an optical projection unit 10 supported by an aiming mechanism (not shown) is housed in a container-shaped 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 the emission of light emitted from the light projection unit 10 by operating the aiming mechanism. The tilt direction of the optical axis L can be adjusted in the vertical and horizontal directions.

The light projection unit 10 has a structure in which a substantially ellipsoidal reflector 14 in which a bulb 12 is attached and a projection lens 16 arranged in front of the reflector 14 are integrated, and the projection lens 16 is a reflector. It is supported by a lens holder (not shown) that is screwed to the lens holder 14. Inside the reflector 14, an elliptical reflecting surface 15 formed by aluminum vapor deposition is formed, and this elliptical reflecting surface 15 has a well-known first focal point F ₁ and second focal point F ₂ and is located at the first focal point F ₁ position. Where the filament of the bulb 12 is located. At the focus position of the projection lens 16 near the second focus F ₂ , a shade 20 for blocking a part of the light reflected by the reflector 14 and directed to the projection lens 16 to form a clear cut line of the sub-beam. Is provided. Then, 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 in the front of the headlamp as substantially parallel light.

As shown in FIGS. 1 and 2, the shade 20 includes a left side (left side when viewed from the lens 16 side) shade 21 and a right side (lens 16) that are horizontally divided from right below the optical axis L. It is composed of a shade 22 and a right side when viewed from the side. Each of the shades 21 and 22 is composed of a cylindrical body having a different diameter, and is rotatably supported by a horizontal support shaft 23. The horizontal support shaft 23, which is a common rotation center of the shades 21 and 22, is provided at positions eccentric to the centers of gravity G ₁ and G ₂ , which are the axial centers of the shades 21 and 22 that are cylindrical rotating bodies, respectively. In other words, the shades 21 and 22 are provided eccentrically with respect to the horizontal support shaft 23, and the shades 21 and 22 rotate, so that the clear cut lines are shown in FIGS. 5A _{1 to} A ₂ and B ₁ to Moves up and down in the range of B ₂ . The symbols d ₁ and d _{2 in} FIG. 4 indicate the eccentric amounts of the shades 21 and 22, respectively.

Reference numerals 25a to 25d in FIG. 2 denote ball bearings, and the shades 21 and 22 are rotatably assembled to a horizontal support shaft 23 fixed to both ends of the frame F via the ball bearings 25a to 25d. ing. Reference numeral 25e is a compression coil spring for pressing the shade 21 toward the shade 22. Further, at least the relative sliding surfaces 21a and 22a of the shades 21 and 22 are made of ceramics, and the relative sliding friction is suppressed to a low level compared to the case where the relative sliding surfaces of the shades 21 and 22 are made of metal. As a result, smooth rotation of the shades 21 and 22 is ensured. Gears 27 and 28 are axially attached to the shades 21 and 22, respectively. The gears 27 and 28 are respectively engaged with drive gears 29 and 30 axially attached to the output shafts of the motors M ₁ and M _2. There is. The shades 21 and 22 driven by a motor M _1, M ₂ are each independently rotated, in the range of _{A 1 ~A 2, B 1 ~B} 2 shown in FIG. 5, the vertical on Haikosu Clean The height and shape of the clear cut line can be arbitrarily adjusted on the left and right of the axis V.

Further, reference numerals 31 and 32 are balance weights respectively integrated with the shades 21 and 22, which are for turning the shades described later by matching the centers of gravity G ₁ and G ₂ of the shades 21 and 22 with the turning center. This is to reduce the load on the motors M ₁ and M ₂ and to smoothly rotate the shades 21 and 22. That is, if the balance weights 31 and 32 are not provided, the load acting on the motors M ₁ and M ₂ is different for each rotational position of the shades 21 and 22, and the inertial load for rotating the shades 21 (22) is different. Since the shade 21 (22) is different in the circumferential position, there is a difference in the time until the shade is rotated to switch the light distribution pattern. However, if the shades 21 and 22 are kept in balance by the balance weights 31 and 32 on the lens side and the reflector side of the horizontal support shaft 23, respectively, the shade 21 (22) is the horizontal support shaft which is the center of rotation. It is balanced around 23, the load (inertial load) of the motors M ₁ and M ₂ is always almost constant, and the time required to rotate the shade is constant regardless of the shade rotation position. And, it has been shortened.

In this embodiment, a shade 20 for forming a right-side light distribution of European and American specifications is disclosed, and a clear cut line formed by the left-side shade 21 is shown in FIG. 4 in which the position indicated by reference numeral 21a is the uppermost position. In the case where the height of the shade 21 is the lowest, the position is A _1, and when the shade 21 is rotated from this position, the clear cut line is gradually lowered, and the position indicated by the reference numeral 21b is the uppermost position ( In the case where the shade 21 has the highest height, the position is A ₂ . On the other hand, regarding the right shade 22, in the mode shown in FIG. 4 in which the position indicated by reference numeral 22a is the uppermost position (the mode in which the height of the shade 22 is the shortest), it is the B ₁ position, and the position indicated by the reference numeral 22b is the uppermost end. In this mode (the mode in which the height of the shade 22 is the highest), the position is B ₂ .

FIG. 6 shows a shade drive control mechanism. Reference numeral 40 is a control unit for controlling the drive amount of the motors M ₁ and M ₂ , and this control unit 40 is provided with the rotational positions of the shades 21 and 22. Shade rotation position information from the position meters P ₁ and P ₂ that are respectively detected is input, and various types of traveling beams such as a traveling beam, a passing beam, a left bending beam, a right bending beam, etc. according to traveling conditions are input. Rotation angle data θ ₁ and θ ₂ of the shades 21 and 22 for forming the light distribution pattern are stored in advance as table data. Then, in the control unit 40, when a signal V corresponding to the traveling condition is input from a sensor 42 such as a means for detecting a steering direction and a steering amount of a steering wheel or a means for detecting a passing beam, the input signal V from the table data is input. The output that matches the above is selected and output to the motor drive circuits 45 and 46, and the motors M ₁ and M ₂ are driven to rotate the shades 21 and 22 by a predetermined amount to obtain a light distribution pattern optimal for the running condition. It is designed to come up.

FIG. 7 is a view showing a cross section of a shade rotating mechanism which is an essential part of the second embodiment of the present invention. In the above-described embodiment, the left and right shades 21 and 22 are configured to rotate independently of each other, but in the present embodiment, the left and right shades are integrated, and one drive motor M _{1 is used.} The shade 20 rotates forward and backward around the horizontal support shaft 23, and the cut line of the light distribution pattern is displaced vertically. Others are the same as those in the first embodiment, and the same reference numerals are given to omit duplicated description.

[0019]

As is apparent from the above description, according to the projection type automobile headlamp of the present invention, when the shade is rotated around the horizontal support shaft, the height of the apex of the shade changes, so that The light pattern (clear cut line) changes up and down, and various light distribution patterns can be adjusted steplessly.

Further, since the center of gravity of the shade and the center of rotation of the shade coincide with each other due to the weight balance, the rotation of the shade is smooth, and the vibration transmitted to the shade acts on the horizontal support shaft that is the shade support portion. The load such as torsion torque is also reduced.

[Brief description of drawings]

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

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 created by a shade and a headlamp from the side of a driver on board.

FIG. 4 is a diagram illustrating the shape of a shade.

FIG. 5 is a diagram showing a change in a clear cut line of a light distribution pattern formed by the headlamp.

FIG. 6 is a block diagram of a shade drive control mechanism.

FIG. 7 is a left-right vertical sectional view of a shade, which is a main part of a second embodiment of the present invention.

FIG. 8 is a vertical sectional view of a conventional projection-type automobile headlamp.

FIG. 9 is a vertical cross-sectional view of the projection type headlamp for an automobile, which is the previous proposal.

[Explanation of symbols]

12 Discharge valve which is a light source 14 Reflector 16 Projection lens 20 Shade for light distribution control 21 Left divided shade 22 Right divided shade 23 Horizontal spindle 31, 32 Balance weight M ₁ , M ₂ Drive motor G ₁ , G ₂ Center of gravity of shade Position F ₁ reflector first focus F ₂ reflector second focus

Claims (1)

[Scope of utility model registration request] 1. A reflector having a substantially ellipsoidal shape, a light source arranged at a substantially first focus of the reflector, a projection lens arranged in front of the reflector, and a vicinity of a substantially second focus of the reflector. And a shade for controlling light distribution, which is arranged at a substantially focal position of the projection lens and blocks a part of the light reflected by the reflector and directed to the projection lens. Is formed in a shape that gradually changes in the circumferential direction, and is structured to rotate about a horizontal spindle that is a center of rotation that is eccentric to the center of gravity of the shade. A headlamp for a projection type automobile for displacing a position vertically to control light distribution, wherein the shade is provided with a balance weight for aligning a center of gravity of the shade with a rotation center of the shade. A projection-type automobile headlamp characterized by being eclipsed.