JP2632082B2 - Lens driving device for variable light distribution type automotive lighting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a variable light distribution type vehicle lamp in which one of two cylindrical lenses is driven to be displaced and a diffusion range of a luminous flux is varied in conjunction with a vehicle speed. And a lens driving device.

[Conventional technology]

Conventionally, two lenses are provided on the front optical axis of a parallel light beam, and one of the lenses is moved in the optical axis direction to converge or diffuse a light beam transmitted through both lenses, thereby changing a light distribution pattern. 2. Description of the Related Art A lens driving device for a variable-type automotive lamp is used.

[Problems to be solved by the invention]

However, in a lamp with this kind of lens driving device,
If two lenses having a large number of cylindrical lens steps are displaced in the pitch direction, the main light source of the optical axis may swing in the lateral direction. There was a problem that the stroke did not guarantee the stopping accuracy of the stroke end and even the breakage occurred.

The present invention has been made in view of the above problems,
To provide a lens driving device for a variable light distribution type automotive lighting device that has no over-stroke of a moving-side lens, eliminates mechanical damage, and can easily drive a moving lens manually from the outside when a motor fails. It is intended for.

[Means for solving the problem]

In order to achieve the above object, a lens driving device for a variable light distribution type automotive lighting device according to the present invention drives one of two cylindrical lenses provided on a front optical axis of a parallel light beam, and spreads a light beam in a diffusion range. In a variable light distribution type automotive lighting device, a movable frame in which a movable lens is fixed is mounted inside a fixed frame in which a fixed lens is fixed, and the movable frame is slidably mounted in the optical axis direction. A protrusion such as a feed roller protruding from the moving frame is slidably fitted into a feed groove formed in a sliding member screwed to a screw shaft provided in a direction perpendicular to the optical axis. A drive-side rotating unit that is rotationally connected to the screw shaft and the drive shaft of the control motor is slidably connected via a rubber belt so as to be slidable, and optical axes are provided at both ends of a moving stroke forming inclined portion of the feed groove. The structure of the forward and backward end portions extending in the orthogonal direction is It is an Abstract that was.

[Action]

According to the above configuration, since the rotating part on the drive side and the displacement side are rotationally connected via the rubber belt that can be expected to slip,
It is possible to release the driving force transmission on both rotation sides. Therefore, for example, when the displacement side reaches the stroke end and is locked, slippage occurs to the outside, and the device is not damaged. In addition, since the forward and backward end portions extending in the direction perpendicular to the optical axis are formed at both ends of the inclined portion for forming the moving stroke of the feed groove, the displacement end is not displaced in the optical axis direction at the stroke end when the displacement is controlled. The position can be secured, and as a result, the position of the moving lens can be displaced with high accuracy.

〔Example〕

Hereinafter, an embodiment of a lens driving device for a variable light distribution type vehicle lamp according to the present invention will be described with reference to the drawings.

A fixed lens 2 is inserted into a rectangular opening formed in the front of the fixed frame 1.
Are fixed so as to be orthogonal to the optical axis L, and guide grooves 3, 3 extending in parallel with the optical axis L are formed on the inner surfaces of both side walls of the fixed frame 1, and the moving frame 4 is provided in the guide grooves 3, 3. The guide rollers 5, 5... Rotatably mounted on the both side members are slidably fitted in the direction of the optical axis L and supported. The movable lens 6 is fitted in a rectangular opening formed in the front surface of the movable frame 4. It is fixed so as to be orthogonal to the optical axis L. The fixed lens 2 and the moving lens 6 constitute cylindrical convex lens steps 2a and 6a having the same pitch, and each lens step corresponds to an axial position parallel to the optical axis L. Reference numeral 7 denotes a projector lamp unit located behind the movable lens 6 on the optical axis L, and a parallel light beam is emitted from the projector lamp unit 7 along the optical axis L. A bearing protruding from the upper wall of the fixed frame 1
A screw shaft 9 orthogonal to the optical axis L is rotatably provided between 8, 8 and a pulley 11 mounted on one end of a rotary shaft 10 provided in parallel with the screw shaft 9. A pulley 12 mounted on one end of the screw shaft 9 is rotatably connected via a rubber belt 13 and a worm pinion 14 mounted on the other end of the rotary shaft 10 and a drive shaft of a control motor 15. Mesh with the worm gear 16,
A rotary drive system is configured. Reference numeral 17 denotes a sliding member having one side screwed into the male screw portion 9a of the screw shaft 9 and slidably supported on a guide bracket 18 fixed to the fixed frame 1. The feed groove 19 formed on the lower surface of the member 17 is protruded from the movable frame 4 via a guide hole 20 extending in the direction of the optical axis L formed on the upper wall of the fixed frame 1 and is rotatably mounted on the shaft. The feed roller 21 is slidably fitted. This feed groove 19
Is formed at both ends of an inclined portion 19b displaced in the direction of the optical axis L, a forward end portion 19a and a retreat side end portion 19c extending in the lateral direction, and form a moving stroke S of the moving lens 6, Limit switches 22, 22 fixed to fixed frame 1
The control motor 15 is intermittently connected to and separated from the edge of the sliding member 17. Reference numeral 23 denotes a rack 24 fixed to the side wall of the moving frame 4 in the direction of the optical axis L, and a pinion gear fixed to the input shaft.
25 is a potentiometer which meshes with the lens 25 and has a structure for detecting the amount of displacement of the moving lens 6 via the moving frame 4.

In the drawing, reference numeral 26 denotes a tension pulley for constantly applying an appropriate tension to the rubber belt 13 rotatably connected between the pulleys 11 and 12, and 27 denotes a coupling 9b formed at one end of the screw shaft 9. This is a manual driver that has a coupler 27a that fits with and is fitted and connected to rotate during manual adjustment.

The lens driving apparatus for a variable light distribution type automotive lighting device having the above-described structure drives the control motor 15 in the forward and reverse directions to rotate the fixed lens 2.
The worm pinion 14 meshed with the worm gear 16 is rotated by the rotational drive of the control motor 15, and is rotated through the rotation shaft 10, the pulley 11, the rubber belt 13, and the pulley 12. The screw shaft 9 is rotated. Since the sliding member 17 is screwed into the male screw portion 9a of the screw shaft 9, when the screw shaft 9 rotates, the sliding member 17 moves and displaces in the axial direction of the screw shaft 9. Then, the sliding member 17
Since the feed groove 19 is displaced (arrow A) with the feed roller 21 fitted, the feed roller 21 slides along the forward end portion 19a, the inclined portion 19b, and the retreat side end portion 19c of the feed groove 21 (guide). The displacement in the direction of arrow A is regulated by the hole 20)
The moving frame 4 on which the moving lens 6 is fixed via the feed roller 21 is displaced in the direction of the optical axis L within the range of the stroke S.

At the time of the above displacement drive, the feed groove 19 in which the feed roller 21 is fitted forms a forward end portion 19a and a retreat side end portion 19c on both sides of the inclined portion 19b, which are not displaced in the stroke S direction. The displacement width of 17 is regulated by limit switches 22 and 22, and the displacement position at the displacement limit is always constant even if the control motor 15 overruns, and the stop position accuracy must be mechanically guaranteed. Can be.
Further, if the rotation shaft 10 continues to rotate while the screw shaft 9 is in the locked state for some reason such as a failure of the control motor 15, the rubber belt 13 slips between the pulleys 11 and 12,
The driving force is released, and damage to the screw portion and the like can be prevented.

If the control motor 15 fails, the coupler 27a of the manual driver 27 is fitted to the coupling 9b formed at one end of the screw shaft 9 to rotate, and the movable lens 6 is manually moved.
The position can be adjusted. At this time, both pulleys 11,1
Since the rubber belt 13 slides between the two, there is no problem even if the rotating shaft 10 is locked.

〔The invention's effect〕

Since the lens driving device of the variable light distribution type automotive lamp according to the present invention is configured as described above, the driving / rotating side is rotated through a structure that performs rotation / linear motion conversion by a screw action and a rubber belt that can be expected to slip. Due to the connection, the driving force can be released, and damage to the device at the time of an accident can be eliminated. In addition, the position of the movable lens can be adjusted with high precision, and the movable lens can be manually adjusted from the outside when the control motor is out of order. The effect obtained by implementing the present invention is extremely large. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a lens driving device for a variable light distribution type automotive lighting device according to the present invention in a partially transparent state, FIG. 2 is a front view in which the same part is cut away, and FIG. FIG. 4 is a cross-sectional plan view of the essential part. DESCRIPTION OF SYMBOLS 1 ... Fixed frame 2 ... Fixed lens 3 ... Guide groove 4 ... Moving frame 5 ... Guide roller, 6 ... Moving lens 7 ... Projector lamp unit 9 ... Screw shaft, 10 ... Rotation Shaft 11, 12 Pulley, 13 Rubber belt 17 Sliding member, 19 Feed groove 21 Feed roller, 23 Potentiometer 27 Manual driver

Claims (1)

(57) [Claims] 1. A variable light distribution type automotive lighting device in which one of two cylindrical lenses provided on a front optical axis of a parallel light beam is driven to change a diffusion range of the light beam, wherein a fixed lens is fixed. A movable frame in which the movable lens is fixed to the fixed frame is slidably mounted in the optical axis direction, and the sliding frame is screwed to a screw shaft provided in a direction perpendicular to the optical axis with respect to the fixed frame. A drive-side rotating part rotatably connected to a feed groove formed in the member and slidably fitted with a protruding member such as a feed roller protruding from the moving frame and a driving shaft of the control shaft and the screw shaft. Are slidably connected via a rubber belt, and the structure of the forward and backward end portions extending in the direction orthogonal to the optical axis is continuously formed at both ends of the moving stroke forming inclined portion of the feed groove. Characteristic Variable light distribution type lens driving device for automotive lighting.