EP2527724B1 - Headlight for automobile - Google Patents

Description

The present invention relates to a headlight for a motor vehicle.

More particularly, the invention relates to the field of headlights for motor vehicles of the type comprising a reflector in which are arranged a light source producing a light beam and means for deformation of the light beam to adapt it to the circumstances of driving.

It is known to use an electrically actuated rotary cut-off strip to move, on command, from a first angular position in which it obscures part of the light beam in order to limit the range of the headlamp to that of the dipped beams so as not to not dazzle other drivers traveling in the opposite direction, at a second angular position in which it does not obscure the light beam, the range of the headlight then corresponding to that of the main beams.

There are also so-called multi-function projectors, in which the cut-off strip can adopt more than two angular positions to selectively obscure the light beam.

Such bars are actuated electrically by an actuator comprising an electric motor and a detector of the angular position of the cut-off bar.

We know in particular, from the document EP 2 088 364 A1 , a vehicle headlight device comprising a reflector in which is disposed a light source as well as a lens and a diaphragm device capable of acting on the emissions of the light source in order to obtain a given light distribution.

A detector frequently used to detect the angular position of the array is the Hall effect detector comprising a sensor and magnet.

In the headlamps of the state of the art, the magnet is placed on a magnet-holder hub located at the level of the bar. Further, the motor is connected to a first printed circuit board and the sensor is connected to a second printed circuit board.

This arrangement has a size which is detrimental to the integration of the actuator in any reflector.

The invention aims to improve the situation.

• une barrette de coupure rotative pouvant se déplacer entre au moins une première position dans laquelle elle n'intercepte pas le faisceau lumineux et une deuxième position dans laquelle elle intercepte au moins une partie du faisceau lumineux ; et
• un actionneur électrique de la barrette de coupure comprenant un moteur électrique et un détecteur de la position angulaire de la barrette à l'aide d'un capteur.

The present invention relates first of all to a headlight for a vehicle automobile comprising a reflector in which are arranged a light source producing a light beam and means for deformation of the light beam, said deformation means comprising:

• a rotary cut-off bar capable of moving between at least a first position in which it does not intercept the light beam and a second position in which it intercepts at least part of the light beam; and
• an electric actuator of the cut-off bar comprising an electric motor and a detector of the angular position of the bar using a sensor.

The headlight of the invention is characterized by the fact that the motor and the sensor are mounted on a single electronic circuit support.

Remarkably, thanks to the connection of the motor and of the position detector on the same support, the actuator of the invention is more compact than the actuators of the state of the art. This allows it to be integrated into any reflector, making it universal.

According to a preferred embodiment, the angular position detector is a Hall effect detector.

The use of a Hall effect detector makes it possible to know precisely, at each instant, an angle of rotation of the bar relative to a reference angle.

Advantageously, the detector comprises a sensor and a magnet placed on the bar.

Unlike the actuators of the state of the art, it is not necessary to provide a magnet-bearing hub. This makes it possible to further improve the saving of space in the headlight of the invention.

Preferably, the electric motor is a step-by-step motor.

This motor makes it possible to have great precision in the rotational movement of the bar caused by this motor.

Advantageously, the support is a printed circuit board, preferably located on the motor and on which the sensor can advantageously be mounted. Thus, not only can the length of the bar be dispensed with, but the whole of the actuator can be placed on the same side of the reflector.

Preferably, said actuator comprises an electrical connector located at a part of the headlight centered with respect to the light beam, called the central part. In this way, it is possible to connect the connecting wires to the electrical connector in the center of the harness and therefore in the center of the headlight. These wires will therefore not interfere with horizontal rotation of the projector, in particular rotation along an axis centered with respect to the beam and perpendicular to the horizontal plane defined by the direction of extension of the cut-off bar and a direction of extension of the beam. Rotating the headlight along this axis does not risk disconnecting the connecting wires from the electrical connector.

Preferably, the electronic circuit support extends longitudinally in a manner substantially perpendicular to the light beam. In this way, the size of the actuator is reduced.

Advantageously, the electronic circuit support extends at least at the level of a part of the headlight centered with respect to the light beam, called the central part. In this way, the connector can be placed directly on the electronic circuit support so as to reduce the size of the actuator.

According to a preferred embodiment, the actuator comprises a temperature sensor connected to the support. The temperature sensor is, in particular, connected to the electrical connector. This temperature sensor makes it possible, in particular, to measure the temperature inside the headlight and to control the motor, for example, when this temperature exceeds a threshold, in order to adapt the operation of the motor and thus prevent it from happening. 'gets too hot.

Preferably, the reflector is of the elliptical type.

This elliptical shape has the advantage of concentrating a lot of light with a low reflector height, which improves the compactness of the projector.

Advantageously, the light source is a xenon lamp or a halogen lamp or a light-emitting diode lamp.

The invention also relates to a motor vehicle equipped with a headlight according to the invention.

• la figure 1 est une vue en perspective représentant un projecteur selon un mode de réalisation de l'invention ;
• la figure 2 est une vue en perspective représentant la structure d'un actionneur d'une barrette de coupure pour un projecteur selon un mode de réalisation de l'invention ; et
• la figure 3 est un schéma représentant un exemple de connexion électrique de l'actionneur de la figure 2.

Embodiments of the invention will now be described in a more precise but non-limiting manner with regard to the appended drawing in which:

• the figure 1 is a perspective view showing a projector according to one embodiment of the invention;
• the figure 2 is a perspective view showing the structure of an actuator of a cut-off bar for a headlight according to an embodiment of the invention; and
• the figure 3 is a diagram showing an example of the electrical connection of the actuator of the figure 2 .

The figure 1 shows an embodiment of the headlight 2 for a motor vehicle according to the invention.

The projector 2 comprises an elliptical reflector 4, a light source 6 and a lens 8. A lens holder 10 secures the lens 8 to the reflector 4.

The light source 6 is of any suitable type, for example a halogen lamp or a xenon lamp or else a light-emitting diode. The light rays from the source 6 are emitted in the direction of the lens 8 after reflection on the reflector 4. These rays then form a light beam.

The light beam produced is directed along a substantially horizontal optical axis and directed towards the front of the vehicle in order to optimally illuminate a route taken. The optical axis defines the center of the light beam.

The projector 2 also comprises a cut-off bar 12 rotating about an axis 14 substantially perpendicular to the optical axis.

A cut-off bar is a cover intended to intercept at least partially, depending on its position, the light beam emitted by the source. The shape of the bar makes it possible to delimit the desired cut-off in the beam.

The cut-off strip 12 is mounted on a frame 16 integrated in the projector 2.

On command, the cut-off bar 12 can take different angular positions, including at least one so-called optically active position, that is to say a position in which it obscures a part of the light beam, so that the projector 2 emits a beam "Cut", in particular a beam of the passing or anti-fog type. The bar 12 can have one or more active positions and a so-called passive position in which it does not obscure the light beam, thus allowing the headlight 2 to emit a light beam without cutting of the high beam type.

The bar 12 shown here comprises an oblique edge 19 making it possible to obtain an oblique cut-off for the emission of a code beam.

An actuator, shown in figure 2 , makes it possible to drive the cut-off bar 12 in rotation from an active position to a passive position, with several possible active positions.

This actuator comprises an electric stepper motor 20 mounted on the frame 16. The use of a stepper motor allows great flexibility in driving the bar 12 from one position to another, this which is advantageous when the projector 2 is of the multi-function type.

The motor 20 drives in rotation a motor shaft 21 supporting a pinion 22. The pinion 22 then drives the bar 12 via a toothed transmission wheel 24 located at one end of the bar 12.

The actuator also comprises a Hall effect detector comprising a sensor 26 and a magnet 28 mounted on the toothed wheel 24, making it possible to precisely detect the angular position of the bar 12 relative to a reference angle. The magnet 28 can be replaced by a metallic element or by any other magnetic element. During the rotation of the bar 12, the sensor 26 determines a variation in the magnetic field due to the displacement of the magnet 28. It deduces therefrom the angular position of the magnet 28 and therefore that of the bar 12.

A printed circuit support 30 is located on the motor 20. This support 30 makes it possible to control the operation of the motor 20 by knowing the angular position of the bar 12 detected by the sensor 26.

Remarkably, the sensor 26 is mounted on the support 30 located on the motor 20. The motor 20 and the sensor 26 are thus connected to a single electronic circuit support 30. The motor 20 is, in particular, welded to the support 30. The direct contact between the motor 20 and the support 30 thus makes it possible to reduce the size of the actuator.

Note that the support can be a box or a card as shown in figure 2 . The support 30 extends longitudinally perpendicular to the beam, that is to say perpendicular to the optical axis. It extends in particular at the level of a part of the headlight centered relative to the light beam, called the central part. The support 30 extends here from a lateral side of the projector to the central part. As shown, the central part is included inside the frame 16. It is defined, in a plane perpendicular to the beam, as extending in a direction, called the first direction, parallel to a direction of longitudinal extension of the beam. cut-off strip 12 and around a axis, called the vertical axis, perpendicular to the previous direction and passing through the optical axis. In other words, the vertical axis crosses the central part. Its extension in the first direction is preferably between 30% and 50% of the length of the frame 16 measured along the direction of longitudinal extension of the cut-off bar. The central part is located, in particular, below the optical axis of the projector.

The sensor 26 is located opposite the magnet 28. It is located on the support 30 and extends in particular perpendicular to the support 30. It is located at the lateral side of the projector from which s 'extends support 30.

The mounting of the sensor 26 on the support 30 makes it possible to dispense with the length of the bar 12 and to have the whole of the actuator on the same side of the reflector 4. In this way, the bulk of the device is reduced. the actuator and therefore the headlight.

The actuator also comprises an electrical connector 31. This electrical connector 31 is, for example, carried by the support 30 and, in particular, connected to the latter. It can also be carried by the motor 20. This particular arrangement allows, again, a saving in size of the actuator.

The figure 3 schematically illustrates the electrical connections of the support and the associated connector 31, by way of example.

According to this example, the connector 31 comprises 8 connection channels. A first channel 32 is intended to be connected to ground.

Two input channels 34, 36 are intended to be connected to the sensor 26.

A third input channel 38 is also provided to be connected to a temperature sensor, not shown.

Four output channels 40, 42, 44, 46 are intended to be connected to the motor 20 to manage its operation.

Due to the fact that the support 30 extends at least at the level of the central part, it is possible, thanks to the invention, to arrange the electrical connector 31 in this central part.

As shown, the electrical connector 31 extends perpendicular to the plane in which the support 30 extends. Connecting wires (not shown) serving, in particular, for connection to the motor 20, are inserted into the connector 31. and are thus oriented perpendicular to the plane in which the support 30 extends.

The projector can be mounted to rotate around a vertical axis, that is to say perpendicular to the extension of the cut-off strip 12 and to the optical axis. Due to the central position of the electrical connector 31 and its orientation, the connecting wires are oriented perpendicular to the axis of rotation of the projector and in a centered manner with respect to the latter. The rotation of the projector is then facilitated by the fact that the connecting wires do not exert any constraint hindering this rotation. This prevents, for example, that a rotation of the projector does not lead to disconnection of the connecting wires.

Of course, still other embodiments can be envisaged, such as, for example, a direct current motor.

Claims (12)

1. Headlight (2) for automobile comprising a reflector (4) wherein are arranged a light source (6) producing a light beam and means for deforming the light beam, said deformation means comprising:

   - a rotating disconnecting strip (12) which can be moved between at least one first position wherein it does not intercept the light beam and a second position wherein it intercepts at least one portion of the light beam; and

   - an electrical actuator of the disconnecting strip (12) comprising an electric motor (20) and a detector of the angular position of the strip using a sensor (26),

   characterised by the fact that the motor (20) and the sensor (26) are mounted on one single electronic circuit support (30).
2. Headlight (2) according to claim 1, characterised by the fact that the detector of angular position is a Hall effect detector (26, 28).
3. Headlight (2) according to claim 2, characterised by the fact that the detector comprises a magnet (28) arranged on the strip (12).
4. Headlight (2) according to one of claims 1 to 3, characterised by the fact that the electric motor (20) is a stepper motor.
5. Headlight (2) according to one of claims 1 to 4, characterised by the fact that the electronic circuit support (30) extends at least at the level of a portion of the headlight (2) centred with respect to the light beam.
6. Headlight (2) according to one of claims 1 to 5, characterised by the fact that the electronic circuit support (30) extends longitudinally substantially perpendicular to the light beam.
7. Headlight (2) according to one of claims 1 to 6, characterised by the fact that said actuator comprises an electric connector (31) situated at the level of a portion of the headlight (2) centred with respect to the light beam.
8. Headlight (2) according to one of claims 1 to 7, characterised by the fact that the support is a printed circuit board (30).
9. Headlight (2) according to one of claims 1 to 8, characterised by the fact that the actuator comprises a temperature sensor connected to the support.
10. Headlight (2) according to one of claims 1 to 9, characterised by the fact that the reflector (4) is of the elliptic type.
11. Headlight (2) according to one of claims 1 to 10, characterised by the fact that the light source (6) is a xenon lamp or a halogen lamp or an LED lamp.
12. Automobile equipped with a headlight (2) according to one of claims 1 to 11.

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