EP0791780A1 - Vehicle headlight with a single light source for dipped and distance light - Google Patents

Abstract

The motor vehicle headlamp has a single filament bulb mounted on its reflector. The reflector is mounted at three points forming the corners of a triangle. To alter the beam height between high and low beam one of the corners of the triangle is displaced, moving between two discrete positions. There is a single displacement actuator (CR), which acts on a single mounting point (V) vertically below a fixed point (PF). The movable mounting point is also connected to an adjuster to set the initial aim of the headlamp. This may be manually operated or dynamically operated.

Description

The present invention relates generally to motor vehicle headlamps.

It relates more particularly to a headlamp capable of emitting a passing beam and a driving beam.

Document FR-A-1 461 607 already discloses in particular a headlamp comprising a single source, in this case a monofilament lamp, which cooperates with a reflector capable of tilting around a horizontal axis perpendicular to its optical axis.

In its downward tilted position, a non-dazzling passing beam is produced, while raising the mirror makes it possible to obtain a longer-range driving beam.

This known headlamp however has an implementation which is totally unsuitable for modern headlamps, and in particular those provided in addition with manual or automatic means for correcting beam orientation in elevation or in azimuth.

Also known from document DE-A-44 18 733, a projector capable of emitting with a single light source (such as a filament or an arc) and a single mirror these two types of beams. To this end, the mirror comprises a fixed part and one or more mobile parts, the movement of the mobile parts using appropriate actuators making it possible to switch from one type of beam to another.

This approach is, however, disadvantageous in that it greatly complicates the design and manufacture of the mirror, and in certain cases induces, in particular at the interfaces between fixed part and mobile part (s), light losses or optical defects. .

Finally, document DE-A-37 22 581, which teaches a headlamp in accordance with the preamble of claim 1, provides for the use of a one-piece mirror cooperating with a single source, and two or more displacement members for passing from a passing beam to a driving beam and vice versa.

The present invention proposes to achieve the same objective with simpler and less expensive means.

Another object of the present invention is to efficiently ensure the combination of a mirror tilting road crossing switching device and other beam correction devices in one and the same projector.

Thus, the present invention firstly provides a motor vehicle headlamp as defined in claim 1.

Preferred, but not limiting, aspects of this projector are set out in claims 2 to 15.

According to a second aspect, the invention proposes a set of two left or right projectors as defined in claim 16.

Finally, according to a third aspect, the invention proposes a set of two left and right projectors as defined in claim 17.

• la figure 1 est une vue schématique en perspective illustrant les trois points d'appui du miroir et l'axe optique d'un projecteur selon une première forme de réalisation de l'invention,
• la figure 2 est une vue partielle en coupe du projecteur, selon la ligne II-II de la figure 1,
• la figure 3 est une vue à échelle agrandie d'un détail de la figure 2,
• la figure 4 illustre schématiquement les contours de deux faisceaux sur un écran de projection, obtenus avec le projecteur des figures 1 à 3,
• la figure 5 est une vue schématique en perspective illustrant les trois points d'appui du miroir et l'axe optique d'un projecteur selon une deuxième forme de réalisation de l'invention,
• la figure 6 est une vue partielle en coupe du projecteur, selon la ligne VI-VI de la figure 5,
• la figure 7 est une vue partielle en coupe du projecteur, selon la ligne VII-VII de la figure 5,
• la figure 8 illustre schématiquement les contours de deux faisceaux sur un écran de projection, obtenus avec le projecteur des figures 5 à 7,
• la figure 9 est une vue schématique en perspective illustrant les trois points d'appui du miroir et l'axe optique d'un projecteur selon une troisième forme de réalisation de l'invention,
• la figure 10 est une vue partielle en coupe du projecteur, selon la ligne X-X de la figure 9,
• la figure 11 est une vue partielle en coupe du projecteur, selon la ligne XI-XI de la figure 9,
• la figure 12 illustre schématiquement les contours de deux faisceaux sur un écran de projection, obtenus avec le projecteur des figures 9 à 11,
• la figure 13 est une vue schématique en perspective illustrant les trois points d'appui des miroirs et les axes optiques de deux projecteurs, gauche et droit, selon une quatrième forme de réalisation de l'invention,
• la figure 14 illustre schématiquement les trois points d'appui d'un miroir de projecteur selon une cinquième forme de réalisation de l'invention et les contours de deux faisceaux sur un écran de projection, obtenus avec ce projecteur,
• la figure 15 illustre en vue de dessus le déplacement du miroir obtenu avec la forme de réalisation de la figure 14, et
• la figure 16 illustre en vue de dessus le déplacement du miroir obtenu avec une variante de cette forme de réalisation.

Other aspects, aims and advantages of the present invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of example and made with reference to the appended drawings, in which:

• FIG. 1 is a schematic perspective view illustrating the three support points of the mirror and the optical axis of a projector according to a first embodiment of the invention,
• FIG. 2 is a partial sectional view of the projector, along line II-II of FIG. 1,
• FIG. 3 is an enlarged view of a detail of FIG. 2,
• Figure 4 schematically illustrates the contours of two beams on a projection screen, obtained with the projector of FIGS. 1 to 3,
• FIG. 5 is a schematic perspective view illustrating the three support points of the mirror and the optical axis of a projector according to a second embodiment of the invention,
• FIG. 6 is a partial sectional view of the projector, along the line VI-VI of FIG. 5,
• FIG. 7 is a partial view in section of the headlight, along the line VII-VII of FIG. 5,
• FIG. 8 schematically illustrates the contours of two beams on a projection screen, obtained with the projector from FIGS. 5 to 7,
• FIG. 9 is a schematic perspective view illustrating the three support points of the mirror and the optical axis of a projector according to a third embodiment of the invention,
• FIG. 10 is a partial sectional view of the projector, along line XX of FIG. 9,
• FIG. 11 is a partial sectional view of the projector, along the line XI-XI of FIG. 9,
• FIG. 12 schematically illustrates the contours of two beams on a projection screen, obtained with the projector from FIGS. 9 to 11,
• FIG. 13 is a schematic perspective view illustrating the three support points of the mirrors and the optical axes of two projectors, left and right, according to a fourth embodiment of the invention,
• FIG. 14 schematically illustrates the three support points of a projector mirror according to a fifth embodiment of the invention and the contours of two beams on a projection screen, obtained with this projector,
• Figure 15 illustrates in top view the displacement of the mirror obtained with the embodiment of Figure 14, and
• FIG. 16 illustrates in top view the displacement of the mirror obtained with a variant of this embodiment.

It will be noted at the outset that, from one embodiment to another, identical or similar elements or parts are designated as far as possible by the same reference signs, and will not be described again each time.

Referring firstly to FIGS. 1 to 3, there is shown a headlamp which comprises, in a housing 30 closed by a crystal (not shown), a mirror 20 in which a lamp 10 is mounted.

The filament or arc lamp defines a single light source.

The mirror is mounted, conventionally per se, on three support points arranged at the three vertices of a right triangle, so as to allow the modification of the orientation of the beam in elevation (vertically) and in azimuth (horizontally) . Here, we call a "point" of support, for example a localized mounting of a rear part of the mirror, on a head forming a ball joint connected to the housing of the projector.

To this end, there is a fixed support point, denoted PF, a mobile support point H situated at the same height as the fixed support point PF and which, when it is translated in a direction essentially parallel to the optical axis xx of the mirror, ensures the azimuth adjustment of the beam, and finally a mobile support point V situated directly above the fixed point PF and which, when it is translated in a direction essentially parallel to said optical axis xx, provides beam elevation adjustment.

• un dispositif de correction manuelle, noté CM, connu en soi et destiné à être manipulé à la main pour donner au faisceau engendré par le miroir une position de référence, ou position zéro, en ayant recours à une instrumentation optique de calibration amenée en face du projecteur alors que le véhicule repose sur un sol horizontal plan; ce réglage manuel est en général un réglage en azimut et le cas échéant en site;
• un dispositif dit de correction dynamique, noté CD, également connu en soi et destiné à être commandé de façon automatique en fonction des variations d'assiette du véhicule, par exemple sur la base de signaux fournis par des capteurs au niveau des essieux, pour ajuster la hauteur du faisceau en fonction de la charge du véhicule et/ou des changements d'assiette dûs à l'état de la route;
• enfin un dispositif de commutation "croisement-route", noté CR, destiné à faire passer le miroir d'une première position, dans laquelle il engendre un faisceau de croisement convenablement positionné en site, c'est-à-dire en général avec orientation de l'axe de référence du miroir inclinée vers le bas de 1%, à une seconde position, dans laquelle le miroir est relevé pour que le faisceau engendré par le miroir, qui dans l'absolu est inchangé, puisse être utilisé comme faisceau de route, le cas échéant avec un faisceau complémentaire comme on le décrira en détail plus loin, et vice-versa.

The projector also comprises various means for moving the two mobile support points in order to modify the orientation of the beam, namely:

• a known manual correction device, denoted CM, in itself and intended to be manipulated by hand to give the beam generated by the mirror a reference position, or zero position, by using optical calibration instrumentation brought in front of the projector while the vehicle is resting on a horizontal ground plan; this manual adjustment is generally an azimuth and, where appropriate, an elevation adjustment;
• a so-called dynamic correction device, denoted CD, also known per se and intended to be controlled automatically as a function of variations in attitude of the vehicle, for example on the basis of signals supplied by sensors at the axles, for adjusting the height of the beam as a function of the vehicle load and / or of the attitude changes due to the road condition;
• finally a "crossing-road" switching device, noted CR, intended to pass the mirror from a first position, in which it generates a passing beam suitably positioned in elevation, that is to say in general with orientation from the reference axis of the mirror inclined downwards by 1%, to a second position, in which the mirror is raised so that the beam generated by the mirror, which in absolute terms is unchanged, can be used as a beam of route, if necessary with a complementary beam as will be described in detail later, and vice-versa.

In this embodiment, the devices CD and CR both operate at point V, and there are two manual correction devices CM operating at point H and at point V, respectively.

Thus the manual correction devices allow a reference adjustment both in elevation and in azimuth.

The CD device conventionally allows dynamic adjustment in elevation, while the CR device, by acting on the fulcrum V, makes it possible to selectively generate the beam F1 or the beam F2 illustrated in FIG. 4.

It will be observed here that the beam F1 is a conventional beam with a so-called "V" cut, in accordance with European regulations on the subject.

Advantageously, the mirror 20 is designed to be able to generate this type of cut beam without having to use a concealment cup, and those skilled in the art will refer to earlier patents in the name of the applicant on this subject.

Furthermore, it is preferable that the mirror 20 is designed, as also described in the aforementioned patents, to generate a beam having the required width without the use of prisms or spreading streaks on the closing glass. This ice can therefore be smooth or very slightly deviating.

In this way, when the beam is moved from the "crossing" position (F1) to the "road" position (F2), the ice remaining immobile, the disturbance phenomena which would be generated if such prisms or streaks were expected.

In this embodiment, the beam F2 is simply raised vertically with respect to the beam F1, thereby lighting the road at a greater distance in front of the vehicle. If necessary, the F2 beam can be supplemented by a narrower F3 beam concentrated on the axis of the road. This additional beam can be produced with a second projector. But given the fact that the amount of light it has to provide is very significantly reduced compared to a conventional road projector, it can be of both horizontal and vertical dimensions extremely small, and not clutter the front of the vehicle.

For example, one can use an additional projector having a height and a width of a few centimeters to ten centimeters.

Figure 3 schematically illustrates an example of realization of the combination of the CM, CD and CR devices at the support point V. It includes a single linear actuator 55 with multiple positions for the functions of the CD and CR devices, which controls the translation of a rod 51 whose front end is threaded in 51a. By appropriate electronic control of the linear actuator 55, the passage from passing beam to driving beam and vice versa is simultaneously ensured and, in the crossing mode, the dynamic correction function as a function of variations in attitude.

The manual corrector CM located at point V comprises a control button 54 driving a set of pinions 53 which rotates the rod 51, the latter having at this level a section, for example square, and being able to slide axially with respect to the pinion with which it is in engagement. The threaded part 51a is engaged with a part 52 trapped in a cage 21 formed at the rear of the mirror 20 and simultaneously forming a ball and nut for said threaded part. In this way, it is possible to give the threaded rod 51 and the mirror a mutual reference position, the dynamic correction and the crossing-road switching being effected from this reference.

• au point d'appui fixe PF, un premier élément du dispositif de commutation croisement-route CR;
• au point d'appui mobile V, un dispositif de correction dynamique CD et le second élément du dispositif de commutation croisement-route CR; et
• au point d'appui mobile H, un dispositif de correction manuelle CM.

Referring now to Figures 5 to 7, there is shown a headlamp comprising:

• at the fixed support point PF, a first element of the crossing-road switching device CR;
• at the mobile support point V, a dynamic correction device CD and the second element of the crossing-road switching device CR; and
• at the mobile support point H, a manual correction device CM.

In this embodiment, manual correction therefore only concerns the reference setting of the beam in azimuth.

The dynamic correction on site is done here again, conventionally, at point V.

On the other hand, the crossing-road switching takes place at two points, PF and V, so as to obtain, in order to pass from the crossing beam F1 to the driving beam F2, the combination of an upward displacement and a lateral displacement, as shown in figure 8.

More precisely, the angle of raising of the beam is chosen so as to provide illumination of the road in the distance, with sufficient intensity (typically a bearing of 1.5%), while the angle of lateral offset is chosen so as to center the spot of concentration of the passing beam F1 in the axis of the road. It should be known in fact that a conventional passing beam has a spot of concentration which is decentered towards the aisle of the road, so as to favor the illumination of this aisle, and the purpose of the offset is to bring back this spot of concentration in the axis. The value of this angular displacement, which therefore takes place to the left for a right-hand traffic direction, is for example 3%.

Concretely, this is achieved by using the switching devices CR so that they cause two different translation values of the support points PF and V, with a greater value at point V. The translation at point PF gives the lateral component of the displacement, and the difference between the translations at points PF and V gives the vertical component of the displacement.

It is understood here that what is called the "fixed point" PF is not strictly speaking in this embodiment, since it moves during the crossing-road switching. However, we continue to call it this because it takes the place of a fixed point during manual and dynamic corrections in one or the other of the two positions.

Referring now to Figures 9 to 12, there is shown a projector which differs from the preceding, first of all, by the fact that the right triangle of support points is reversed, the point V being here above the point PF, the points PF and H being swapped and the triangle being rectangle at the point PF.

• au point d'appui PF, le dispositif de commutation croisement-route CR;
• au point d'appui H, un premier dispositif de correction manuelle CM; et
• au point d'appui V, un second dispositif de correction manuelle CM ainsi que le dispositif de correction dynamique CD.

We find :

• at the point of support PF, the crossing-road switching device CR;
• at the fulcrum H, a first manual correction device CM; and
• at the fulcrum V, a second manual correction device CM as well as the dynamic correction device CD.

The two manual correction devices allow beam reference adjustment both in elevation (action at point V) and in azimuth (action at point H).

The dynamic correction device acts, conventionally, at point V.

The crossing-road switching device is remarkable in this embodiment in that it acts at a single point, namely the fixed point PF, to rotate the mirror around an axis passing through the diagonal of the right triangle, which joins the moving points H and V.

In this way, the upward and lateral offset of the passing beam F1 is produced simultaneously to form the driving beam F2.

More precisely, if the angle of the hypotenuse HV with respect to the horizontal is noted α, then the angle of the direction of movement of the beam in the projection plane will be of this same value α, but relative to the vertical (see Figure 12).

Thus, the location of the three points PF, H and V at the rear of the mirror is chosen so as to obtain the desired displacement obliquity.

Thanks to this embodiment, the crossing-road switching can be carried out with a single CR device.

Referring now to Figure 13, there is shown the arrangement of headlights / crossover switches on the left and right headlights of a vehicle.

The left projector has an optical axis x _G x _G and three support points PF _G , H _G and V _G. The right headlamp has an optical axis x _D x _D and three support points PF _D , H _D and V _D. As can be seen, the two right triangles whose respective support points define the vertices are symmetrical with respect to a median vertical plane of the vehicle.

• aux points d'appui fixes PF_G, PF_D, respectivement des dispositifs de correction manuelle,
• aux points d'appui H_G, H_D, respectivement des premiers éléments de dispositif de commutation croisement/route CR, et
• aux points d'appui V_G, V_D, respectivement des seconds éléments de dispositif de commutation croisement/route CR et des dispositifs de correction dynamique CD.

In addition, provision is made in this embodiment:

• at fixed support points PF _G , PF _D , respectively manual correction devices,
• at the support points H _G , H _D , respectively of the first elements of the crossing / road switching device CR, and
• at the support points V _G , V _D , respectively of the second elements of the crossing / road switching device CR and of the dynamic correction devices CD.

So that the offset of the passing beams in order to form the driving beams is identical in the two cases, it is understood that the switching devices CR located at the points V _G , V _D must act in the same direction, while the correctors CR located at points H _G , H _D must act in opposite directions.

Referring now to Figures 14 to 16, there is shown another alternative embodiment of the invention.

FIG. 14 shows in the lower part three support points PF, H and V, with two elements of the crossing-road switching device CR provided respectively at points H and V.

In this embodiment, as illustrated in FIG. 15, the displacement stroke D of the switching element CR placed at the fulcrum H must be large, up to 20 mm in some cases. This implies a possibility of significant movement of the mirror 20 in the housing 30, and therefore an oversizing of the housing.

To alleviate this problem, this variant provides for crossing-road switching by adding a third element CR 'to the support point PF, and by giving the switching movements at points PF and H opposite directions but of the same amplitude, at know an amplitude D / 2 equal to half that required at point H in the embodiment of FIG. 14.

In this way, and as illustrated in FIG. 16, it follows that the amplitude of movement at the bearing points concerned is reduced, and the oversizing of the housing is less significant.

We will give below additional explanations valid for all embodiments where a dynamic correction device CD and a crossing-road switching element CR operate on the same fulcrum, taking as an example the case where this combination , denoted CD + CR1, intervenes at the fulcrum V, while the fulcrum H has another crossing-road switching element CR2 at the H point.

Typically, the stroke of the dynamic corrector is 8 mm. The travel of the CR1 switch will for example be 4 mm, while the travel of the CR2 switch will be 3 mm.

• déconnecter obligatoirement les informations de correction dynamique fournies par les capteurs d'assiette du véhicule; le calculateur ne délivre alors au dispositif CD qu'une information statique, pour le figer dans la position à laquelle il se trouve; en effet, la correction dynamique d'assiette dans le mode route n'est pas obligatoire;
• expédier obligatoirement à l'élément CR1 l'information de déplacement sur 4 mm, et à l'élément CR2 l'information de déplacement sur 3 mm, pour ainsi effectuer à proprement-parler le passage de faisceau de croisement (F1 par exemple sur la figure 8) à faisceau de route (F2 sur cette même figure);
• le cas échéant, si un projecteur complémentaire est prévu pour la position route (faisceau F3), allumer la lampe de celui-ci; et
• enfin, dans le cas où la lampe est complétée par un occulteur de faisceau de croisement, formant notamment cache de lumière directe ou encore coupelle d'occultation (du type de celui du filament antérieur d'une lampe normalisée H4) en coopération avec un miroir parabolique, escamoter cet occulteur pour accroître le flux lumineux.

When passing from the driving beam to the driving beam, conventionally carried out on the vehicle's commodo, an electronic computer is suitable for:

• necessarily disconnect the dynamic correction information provided by the attitude sensors of the vehicle; the computer then delivers to the device CD only static information, to freeze it in the position at which it is located; in fact, the dynamic attitude correction in the road mode is not compulsory;
• send the displacement information over 4 mm to the CR1 element, and to the CR2 element the displacement information over 3 mm, so as to strictly speaking pass from the passing beam (F1 for example in FIG. 8) to the driving beam (F2 in this same figure);
• if necessary, if an additional headlamp is provided for the road position (harness F3), switch on the lamp; and
• finally, in the case where the lamp is completed by a passing beam concealer, in particular forming a cache of direct light or an obscuring cup (of the type of that of the anterior filament of a H4 standard lamp) in cooperation with a mirror parabolic, retract this blackout to increase the luminous flux.

Naturally, these operations are carried out simultaneously, and the reverse operations are carried out for the return from driving beam to passing beam.

It will be observed that the combination of the first two operations described above makes it possible to avoid having to use a separate plate for mounting the CD and CR1 devices, which can both be mounted directly on the case and share the same electric motor.

On the other hand, when a manual correction device CM and a dynamic correction device CD are provided at the same fulcrum, it is necessary to fix the device CM on the housing, and to fix the device CD on a movable movable stage by the CM corrector.

In practical terms, the crossing-road switching elements, the function of which is that of linear actuators with two discrete positions, can be constituted by electromagnets with two positions, by torque-locked motors or by motors. step by step.

Finally, it will be observed that the principle of displacement of the passing beam to form a driving beam in accordance with the present invention can also be implemented in projectors where the mounting of the mirror on the housing is carried out by means other than a triplet of support points.

Claims (17)

Motor vehicle headlamp, comprising a single light source (10), a single mirror (20) receiving the lamp and mounted on three support points (PF, H, V) arranged at the three vertices of a triangle, and means movement controlled to selectively move in translation at least one of the support points in one of an assembly limited to two discrete positions, namely a first position corresponding to a passing beam (F1) and a second position ( F2), raised, corresponding to a main beam, characterized in that the displacement means comprise a single displacement member (CR) acting at a single bearing point (V; PF). Projector according to claim 1, characterized in that it comprises a member (CR) for translational movement of a fulcrum (V) situated directly above a fixed point (PF). Projector according to claim 2, characterized in that it further comprises at said support point (V) situated directly above the fixed point (PF) at least one device (CM, CD) for correcting beam orientation in site. Projector according to claim 3, characterized in that said correction device is a manual device (CM). Headlamp according to claim 3 or 4, characterized in that said correction device is a dynamic correction device (CD) according to variations in the attitude of the vehicle. Headlamp according to claim 1, characterized in that the single displacement member (CR) is capable of picking up the beam and shifting it laterally opposite the side of the road. Projector according to claim 6, characterized in that the single displacement member (CR) is located at a support point (PF) opposite to one side (HV) of the oblique triangle with respect to the horizontal and with respect to the vertical. Projector according to claim 7, characterized in that it further comprises a dynamic correction device (CD) according to the variations in attitude of the vehicle, provided at a support point (V) located at the plumb of said support point (PF) opposite an oblique side of the triangle. Projector according to one of claims 7 and 8, characterized in that it further comprises at least one device (CM) for manual beam correction located at a support point (H, V) different from said point support (PF) opposite an oblique side of the triangle. Projector according to one of Claims 7 to 9, characterized in that the inclination (α) of said oblique side (HV) of the triangle relative to the horizontal is chosen to be equal to the inclination of the direction of movement of the beam by compared to the vertical. Projector according to one of claims 6 to 10, characterized in that the ratio between the angle of lateral offset of the beam and its angle of lifting is of the order of 2: 1. Projector according to one of claims 1 to 11, characterized in that it comprises a mirror (20) capable of forming by itself a very wide crossing beam, and in that the glass is smooth or slightly deflecting. Projector according to claim 5, characterized in that the displacement member (CR) and the dynamic correction device (CD) share the same motor. Projector according to one of claims 1 to 13, characterized in that the displacement member (CR) is chosen from the group comprising two-position electromagnets, locked torque motors and stepper motors. Projector according to one of claims 1 to 14, characterized in that it further comprises means (CD) for effecting a dynamic correction of the orientation of the mirror as a function of variations in attitude of the vehicle, and means for inactivate said means when switching to a driving beam. Left or right assembly of two motor vehicle headlamps, characterized in that it comprises a first headlamp according to one of claims 1 to 15 and a second headlamp of smaller dimensions, capable of being switched on when the beam emitted by the first headlamp is brought into its high beam position (F2). Set of two left and right headlights of a motor vehicle, characterized in that it comprises two headlights according to one of claims 1 to 15, in that the support points (PF _G , H _G , V _G ) d ' a projector are symmetrically arranged support points (PF _D , H _D , V _C ) of the other projector relative to a vertical median plane of the vehicle, and in that the member for translational movement (CR) of a fulcrum (H _G ) of one of the headlights and the member for translational displacement (CR) of a point of support (H _D ) homologous to the other projector act in opposite directions with respect to each other.

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