OPTICAL SYSTEM WITH A MECHANISM FOR THE COMPENSATION OF THERMAL INFLUENCES

The available invention concerns an optical system with a housing, which is taken up by a photograph element, whereby in the housing at least an optical means is taken up and whereby in the connecting chain between the photograph element and the optical means at least one compensating element is arranged.

An optical system of the kind interesting here can concern for example a headlight for a motor vehicle like a passenger car or also a commercial motor vehicle. The photograph element by a framework element of the motor vehicle and the optical means are by a light module taken up in the headlight are formed. The headlight possesses a housing, which is connected by several interconnect points with the framework element of the motor vehicle. The framework element can concern for example a front cross beam, a structural construction unit or an other photograph part, which is for the arrangement of the headlight a component of the motor vehicle. Inside the housing of the headlight the light module is taken up, which is movably arranged frequently over mechanical setters. For the admission a photography module can serve, which forms mechanical connections between the light module and the housing of the headlight. Frequently light modules at the rear wall of the housing of the headlight can be arranged, whereby the photography module can cover adjusting elements, over which the situation of the light module relatively for the framework element of the motor vehicle changeable are. However the housing is connected mostly rigidly with the framework element. In the result a connecting chain between the framework element of the motor vehicle and the light module is formed, which covers at least one interconnect point between the framework element and the housing of the headlight as well as the connection of the light module with the housing of the headlight over the photography module.

Furthermore the optical system can be trained as a sensor facility with a housing, whereby the optical means is formed by a sensor element taken up in the housing. In particular the sensor facility can be applicable implemented and preferably as camera system as front camera for a motor vehicle, whereby the sensor element is formed by a picture version unit. Such cameras can be arranged vehicle-interiorlaterally at the windshield, for example behind the rear view mirror. By substantial heat entry, approximately by solar radiation, an inadmissible deviation of the situation picture version unit of the camera of the called optical means can enter, since in particular the housing forgave yourself.

From the DE 35 18 404 A1 an optical system is well-known in shape of a headlight for a motor vehicle, which exhibits an low beam screen, which is in such a manner installed that it is hung up by means of an auxiliary piece in a carrier, whereby the carrier, the low beam screen and the auxiliary piece possess relative dimensions and linear thermal expansion coefficients, so that regardless of the changes of the period of operation the upper edge of delimitation of the low beam screen maintains a constant situation regarding the horizontal. Disadvantage detention is during a such execution the very complex admission of the light module, which must be fastened in not one-piece form both front-laterally and back divided in a reflector and a projection lens to a foot. This cooperates with a mounting plate, at which the lens is arranged, whereas the reflector at the foot must be arranged. In particular a piece of auxiliary hanging up is necessary, in order to hang the screen up, which generates the light dark border, within the light module. In the result a constant position of the screen can be only achieved regarding the horizontal, whereby for example a tilting of the entire cannot become balanced made of reflector and lens existing unit in the headlight. The thermal compensation concerns from there only the components of the light module, so that arising tilting of the light module in the headlight and/or in the motor vehicle cannot be compensated.

The light module can send a headlight low beam with a light dark border, whereby it is to be noted that the light dark border may not exceed a prescribed height regarding the horizontal. In the case of an unfavorable thermal influence of the headlight however an inadmissible rise of the light dark border can develop due to the thermal expansion behavior of the materials. These materials concern the materials of the housing, the photography module and the light module. The thermal influence of the headlight concerns on the one hand a change of the ambient temperature, weather-related or due to influencing engine warmth, and the fuel enterprise of the shining means, which is operated in the light module. Thus a temperature stratification can occur within the headlight, which leads to the fact that materials within warm ranges can exhibit a stronger stretch than materials within colder ranges. It is well-known to use for the creation of the photography module of materials a substantially lower thermal expansion coefficient exhibits than for example the housing, however the unchanged situation of the light module cannot be placed relatively for the framework element of the motor vehicle alone by a favourable selection of different materials of the photography module and the housing surely.

The figures 1 and 2 show an arrangement of a headlight for a motor vehicle, whereby the headlight is shown in a warm condition in figure 1, which predominates for example by the fuel enterprise of the shining means in the light module or weather-related. Figure 2 shows however a headlight for a motor vehicle in a cooled down condition. The headlight in the figures 1 and 2 is represented schematized and possesses a housing 10, which is front-laterally in a framework element 11 of the motor vehicle integrated. The light module 12 is arranged over a photography module 13 at the rear wall of the housing 10 of the headlight. The level, which is stretched by the interconnect points 17 between the housing 10 and the framework element 11, is to the light dark border 24, available simplified as horizontal level represented, strongly bent. However the level, which is formed by the points 18 between the photography module 13 and the light module 12, is not bent and runs about perpendicularly to the light dark border 24.

In accordance with the representation it is recognizable that the light dark border 24 is raised by the transition of the warm to the cold condition of the headlight. The cause for this is a deviation of the level, which are formed by the points 18. By the deviation of the level mentioned Längendifferenzen in the upper and lower wall of the housing form 10 in the comparison to the upper and lower range of the photography module 13 between the rear wall of the housing 10 and the light module 12. For constructional reasons however a parallel process of the level of the interconnect points 17 and the level is possible by the points 18 not always.

It is from there the task of the available invention to create an optical system with an optical means whereby the situation of the optical means exhibits an improved thermal stability.

This task is solved on the basis of an optical system in accordance with the generic term of the requirement 1 in connection with the characteristic characteristics. Favourable further educations of the invention are indicated in the dependent requirements.

The invention includes the technical teachings that the compensating element exhibits a conical diaphragm and a compensation body, which cooperate in such a manner with the diaphragm that in the diaphragm a thermally conditioned adjusting path is producible, over which a thermally caused change of the situation of the optical means relative to the photograph element balancable are.

The invention proceeds thereby from the thought to create an optical system with at least one compensating element which is arranged in the connecting chain between the optical means and the photograph element. By the arrangement according to invention of the compensating element with a diaphragm and a compensation body it is reached that the compensation body works in such a manner with the diaphragm together that in the diaphragm a thermally conditioned adjusting path is producible.

This adjusting path is used to adjust a thermally caused change the situation of the optical means in the photograph element as the adjusting path of the thermal misalignment of the optical means works against. On the basis of one from the state of the art admitted to compensating element, which uses the linear thermal stretch of a material with a high thermal expansion coefficient, created by the cooperation of a compensation body with the diaphragm a thermalmechanical amplifier, by which a large adjusting path one will make available can, without planning large spatial dimensions for the compensating element.

A diaphragm describes a stretch body with a flat extending in the sense of the available invention, whereby the diaphragm in its geometrical arrangement can be selected freely. Reinforcement effect used to supply large adjusting path thereby that the diaphragm in the level, in which this extends expands. The expansion of the diaphragm material in at least one direction is restrained by the compensation body, so that the diaphragm implements an evasive action, which is used for the supply of the adjusting path.

After a possible execution form the optical system can be trained as headlights with a housing for a motor vehicle, whereby the photograph element by a framework element of the motor vehicle and the optical means are formed by a light module taken up in the headlight. The housing can be connected by at least one interconnect point with the framework element of the motor vehicle, whereby at least one compensating element is arranged in the interconnect point. Furthermore can be intended to hang up the light module by the photography module over at least one point whereby that is arranged at least a compensating element in the point.

There are several meaningful positions for the compensating element from thermal view. This can be completely in the equipment inside available, affected by the there relevant interior temperature and particularly strongly affected by internal warmth a setting free operating condition of the light module. Furthermore the compensating element can be completely outside of the housing arranged, affected by the there relevant ambient temperature and to a large extent uninfluenced by whether the headlight sets internal warmth free by its enterprise. In particular the compensating element can be as part of the housing wall trained, affected by a mixture from Umgebungsund predominating there interior temperature and not uninfluenced by internal warmth a setting free operating condition of the light module.

Which temperature gives the excursion here, particularly by the convection conditions one determines, which are shapable by the equipment design again. From the interior arranged internal diaphragm surface exposes and from the outside rather convection arranged diaphragm means a predominant influence of the diaphragm by the interior temperature with strong influence by a warmth a setting free fuel enterprise of the light module.

Frequently three point photographs are intended between the housing and the framework element as well as between the light module and the housing, whereby at least an interconnect point and/or a point can cover an adjusting possibility, in order to adjust the situation of the light module relatively for the framework element of the motor vehicle. This adjustment concerns in particular the light dark border in the adjustment of the height. Due to newer creations of form of the motor vehicle front portion with a strong flattening within the range of the assembly of the headlights in the framework element the level, which is stretched by the three point admission to the arrangement of the headlight in the framework element, is strongly bent to the longitudinal direction of the vehicle. However the three point admission of the light module in the housing of the headlight can stretch one level, which runs at least essentially perpendicularly to the light withdrawal direction of the headlight or another diagonal possesses a smaller and/or generally a case, as the level, which is stretched by the three point admission of the housing of the headlight in the framework element.

In accordance with a particularly favourable execution form the diaphragm is trichterförmig trained and can extend around an axle, so that the diaphragm exhibits one oh near inside and a oh-far exterior. The compensation body can form a torus, which encloses the diaphragm over the oh-far exterior. Therefore the trichterförmige diaphragm forms a hollow cone with a cone angle, whereby the cone angle changes with a change of the temperature of the diaphragm. The change of the cone angle is caused by a thermal expansion of the material of the diaphragm, so that the adjusting path is produced toward to the axle of the diaphragm by the inside in relation to the exterior of the diaphragm.

In order to use the adjusting path of the inside of the diaphragm relative to the exterior for the compensation of the thermally caused position change of the light module, a connecting piece can follow the inside of the diaphragm. This connecting piece can form for example a hollow cylinder, which extends likewise rotationally symmetrically around the axle. The diaphragm can favourable-proves to be rotationally symmetrically trained, however an organization of the diaphragm is likewise possible as Polygon or in form of a multiplicity of spokes, which extend between the ohnear inside and the oh-far exterior predominantly radially, so that available the Kegelform of the diaphragm is not to be understood in the mathematical sense, but rather the abstract, macroscopic form of the diaphragm describes. In particular if the diaphragm from a multiplicity of spokes is formed, are void tangential tensions in the diaphragm, which can form due to thermal stretches. If tightness of the diaphragm, for example opposite liquids or gases, should be necessary, the spokes of the diaphragm can be covered with a sealing material. Furthermore the diaphragm can exhibit a wave shape, whereby the education is likewise avoided by tangential voltages, however tightness in relation to media specified above-mentioned is attainable. The material of the diaphragm can be selected in such a manner that this exhibits a large thermal expansion coefficient, whereby the thermal expansion coefficient of the diaphragm must be larger than the thermal expansion coefficient of the torus. For example the torus from a metallic material can be trained, whereas the diaphragm can exhibit PP, PBT, Pa, PC, POM or a PMMA.

It is of advantage special, if the torus is umspritzt over the exterior of the diaphragm screwed on, shrunk, pressed on or with the material of the diaphragm. If the thermal expansion coefficient of the material of the diaphragm is substantially more highly than the thermal expansion coefficient of the torus, for example around a factor 6 to 10, then the diameter of the torus can be accepted as temperature independent. Over the exterior of the diaphragm and/or over the torus the compensating element can be taken up in the interconnect point and/or in the point, whereby the headlight casing and/or the light module is connected by the connecting piece. In order to increase the adjusting path the correction of the situation of the light module relative to the framework element, several compensating elements can be arranged mechanically in a row. Thus the single adjusting paths of the diaphragms if necessary arranged in different thermal zones can add themselves and/or overlay in an appropriate way in such a way that the influences of the entering thermal scenarios affect compensating as possible multiplicity of combinations of single temperatures in the thermal zones in the housing the adjustment of the light module.

Preferably the compensating element can be in such a manner arranged that at least on a side a convection between the diaphragm and the ambient air of the headlight is made possible for the trichterförmigen diaphragm. This possibility can be created both with a compensating element in an interconnect point between the framework element and the housing and with a compensating element in the point between the housing and the light module. From it the advantage results that the diaphragm can be accepted by convection the ambient temperature and/or be warmed up directly or cooled down by these can. In particular the compensating element can be in such a manner arranged that the diaphragm forms a part of the housing of the headlight. If the compensating element is arranged in a point between the light module and the housing, the photography module can serve as connection between the light module and the point. The photography module can arrange the light module at the rear wall of the housing, so that the compensating element in the rear wall of the housing can be integrated, and so that the connecting piece of the compensating element is brought in connection with the photography module. Furthermore the housing of the headlight can exhibit attachment arms, which are externallaterally attached at the housing and form finallaterally the interconnect point to the framework element. The interconnect points at the attachment arms of the housing can enclose for example the diaphragm, whereby the torus can be a component of the circular confinement of the interconnect point around the diaphragm.

As the highest integration level with a compensating element attached inside the outside or the internal connecting piece as well as the diaphragm from the same material are formed, from which also an anyway necessary Befestigungsoder guiing device is formed, for example POM, PBT or Pa. The compensation body is formed by the material, made of which also connection geometry of the optical system is formed, for example a Metallblech a metal casting or a BMC. Is not thus despite thermal balance function an additional construction unit which can be come necessary.

As the highest integration level with a compensating element attached outside the outside or the internal connecting piece as well as the diaphragm from the same material formed, from which also the housing is formed, for example PP, PBT, Pa or EXP. of the compensation bodies are formed by the material, made of which also an anyway necessary reinforcement element at the fastening spot is formed to the body, for example a Metallhülse, a sheet metal clip or a plastic element. Is not thus despite thermal balance function an additional construction unit which can be come necessary.

As the highest integration level with a compensating element attached in the housing wall the outside and internal connecting piece as well as the diaphragm from the same material formed, from which also the housing is formed, for example PP, PBT, Pa or EXP. of the compensation bodies are formed either by the material, from which also an anyway necessary adjusting element at the fastening spot is formed to the optical system, for example a metallic threaded rod. Is not thus despite thermal balance function an additional construction unit which can be come necessary. Or the compensation body is formed from an additional construction unit, which is put on preferably from the outside with the headlight assembly on the housing or already with the shaping process of the housing into the housing one integrates.

Preferably it is valid for the outside and the internal connecting piece that a change of material between diaphragm and connecting piece can be present; whereby the connecting piece is then trained preferably from the same material, made of which also the compensation body is formed. The diaphragm and the connecting piece can be formed from the same material, then the compensation body is put on on the connecting piece in the proximity of the edge of diaphragm.

If connecting piece and diaphragm consist exterior of the same material, then the outside connecting piece is hollow” implemented “; if a change of material between diaphragm and outside connecting piece is present, the connecting piece can be implemented also “substantial”. The internal connecting piece can be substantial or hollow implemented, independently of whether a change of material between connecting piece and diaphragm is present.

After a further execution form the optical system than sensor facility with a housing can be trained, whereby the optical means is formed by a sensor element taken up in the housing. The sensor facility can be implemented as camera system and be preferably used as front camera for a motor vehicle, whereby the sensor element is formed by a picture version unit. The housing of the sensor facility and the admission of the sensor element are influenceable by a compensating element in same way as also with a headlight. Therefore in the following remark examples with a headlight is only dealt, whereby the effect connections are similarly transferable to a sensor facility.

Further ones, the invention improving measures are more near represented below together with the description of a preferential remark example of the invention on the basis the figures. It shows:

Fig. 1

a headlight for a motor vehicle in a schematic representation, whereby the headlight is shown in a condition at operating temperature and the light module exhibits the intended situation,

Fig. 2

the headlight in accordance with the state of the art after figure 1, whereby the headlight is shown in the cooled down condition and is shown in a situation deviated from the intended situation the light module,

Fig. 3

a headlight for a motor vehicle with an arrangement according to invention of a compensating element between the housing and the framework element, whereby the headlight is shown in a condition at operating temperature,

Fig. 4

a representation of the headlight in accordance with Fig. 3, whereby the headlight is shown in a cooled down condition,

Fig. 5

a further remark example of a headlight in a condition at operating temperature with a compensating element between the housing and the framework element of the motor vehicle in a condition at operating temperature,

Fig. 6

a representation of the headlight in accordance with Fig. 5, whereby the headlight is shown in a cooled down condition,

Fig. 7

a further remark example of a headlight of a motor vehicle with a compensating element, which is arranged between the housing of the headlight and the light module, whereby the headlight is shown in a condition at operating temperature,

Fig. 8

a representation of the headlight in accordance with Fig. 7, whereby the headlight is shown in a cooled down condition and

Fig. 9

a detail opinion of a compensating element in accordance with the available invention.

The figures 1 and 2 show a headlight for a motor vehicle in accordance with the state of the art as managing already descriptive.

The figures 3 and 4 show a headlight for a motor vehicle with a housing 10, which is connected with a framework element 11 of the motor vehicle. A light module 12 is arranged over a photography module 13 at the rear wall of the housing 10 of the headlight. A compensating element 14 is arranged at the lower interconnect point 17 between the housing 10 and the framework element 11. Due to the diagonal of the connecting level between the housing 10 and the framework element 11 the housing 10 on the lower side exhibits a larger length than on the upper side.

Figure 3 shows the headlight in a condition at operating temperature, whereby figure 4 shows a cooled down condition of the housing 10. Since the housing 10 on the lower side exhibits a larger length than on the upper side, first on the lower side a stronger misalignment of the rear wall and therefore to take place, sees is caused for the photography module 13 of the housing 10 however according to invention figure 2. by the balance effect of the compensating element 14 an adjusting path 23, which adjusts for the difference of the geometry change of the lower Gehäuseteils opposite the upper Gehäuseteil. A comparison of the compensating elements 14 in figure 3 and figure 4 shows that the diaphragm 15 of the compensating element 14 exhibits a flatter angle after cooling. In effect connection with the compensation body 16, which encloses the diaphragm 15 externallaterally, the appropriate adjusting path 23 is produced. In the result the light dark border 24 of the light module 12 remains existing in the horizontals.

The figures 5 and 6 show a further remark example of a headlight of a motor vehicle with a photography module 13, which is divided into a photography module 13 ' and a photography module 13 ". The photography module 13 ' possesses a material with a low thermal expansion coefficient, whereby the photography module 13 exhibits " a material with a high thermal expansion coefficient. Due to the Längendifferenz between the upper and lower range of the photography module 13 ' and 13 " a cooling of the headlight would lead first to a sinking of the light dark border 24. In order to work against this sinking, the compensating element 14 is in such a manner trained that an adjusting path 23 on the housing 10 is given, that the thermal behavior of the housing 10 on the upper and on the lower side, under the Längendifferenz, further supported. A comparison of the diaphragms 15 in the figures 5 and 6 makes clear that the angle of the diaphragm opens 15 with cooling. In accordance with the representation the housing 10 at the compensation body 16 or coupled at the oh-far exterior 21 is, whereby the compensating element 14 over the connecting piece 22 at the framework element 11 is arranged. Therefore results an adjusting path 23, which moves the lower range of the housing 10 toward to the framework element 11. Since the material of the photography module 13 possesses ' a lower thermal expansion coefficient than the material of the photography module 13 " and there the length of the photography module is larger 13 ' on the upper side than on the lower side, without the adjusting path 23 the light module 12 was tilted and the light dark border 24 would drop. This misalignment can become balanced with the arrangement according to invention of the compensating element 14.

The figures 7 and 8 show a further remark example of a headlight with a housing 10, which likewise exhibits a larger length on the lower side than on the upper side. Over the photography module the light module 12 again back arranged 13 ' and 13 " at the housing 10 is, whereby a compensating element 14 between the photography module 13 is arranged and the housing 10 and whereby the arrangement of the compensating element 14 in the point 18 takes place. Available the point can do 18 both between the light module 12 and the photography module 13 (13 ', 13 ") and between the photography module 13 (13 ', 13 ") and the rear wall of the housing 10 to be understood. By the compensating element 14 again dumps of the light module 12 and thus the light dark border 24 is avoided, since an adjusting path 23 is formed, which adjusts the larger length of the lower photography module 13 " with high thermal expansion coefficient. In accordance with the representation only a compensating element 14 intended between the light module 12 is and the housing 10, whereby a further compensating element 14 between the photography module 13 can be preferably planned ' on their lower surface and the light module 12, so that the adjusting paths 23 of the compensating elements 14 can add themselves.

Figure 9 shows a detailed opinion of the compensating element 14 in a situation taken up in the housing 10. The compensating element 14 is formed from a diaphragm 15, which possesses a Kegelform and rotationally symmetrically around the axle 19 is trained. The Kegelform can possess an opening angle from for example 120° to 140°, whereby the cone opening angle of the diaphragm 15 as a function of the temperature can change. The broken representation of the diaphragm 15 and the connecting piece 22 shows the compensating element 14 at a increased temperature, whereby the pulled through body edges represent the compensating element 14 at a lower temperature. If the temperature within a range changes, as this can occur between an enterprise and a state of rest of a headlight and/or a motor vehicle, then the opening angle of the diaphragm changes for example from 140° on 120°. Itself the adjusting path 23 devoted from it can exhibit a factor 10 of the change of the radial length of the diaphragm 15, so that a thermalmechanical amplifier is formed.

The diaphragm 15 exhibits one oh near inside 20 and a oh-far exterior 21, whereby the diaphragm 15 by a torus 16 over the exterior 21 is enclosed. The torus 16 possesses a thermal expansion coefficient, which is smaller than the thermal expansion coefficient of the diaphragm 15. In order to prevent that the diaphragm 15 expands when heating up radially and pulls together with cooling toward to the ohnear inside 20 again, the torus works 16 as compensation body 16, in order to keep the outside diameter of the diaphragm 15 constant. In the result the adjusting path 23 is produced, which is finallaterally at the connecting piece 22 drawn.

The invention is limited its execution to that managing not indicated preferential remark example. Rather a number of variants is conceivable, which from the represented solution with in principle differently constituted remarks use makes. All from the requirements, the description or the designs coming out characteristics and/or advantages, including features of design, spatial arrangements and process steps, can be invention substantial both for itself and in the most diverse combinations.

10

Housing

11

Framework element

12

Light module

13

Photography module

13 '

Photography module, material with low thermal expansion coefficient

13 "

Photography module, material with high thermal expansion coefficient

14

Compensating element

15

Diaphragm

16

Compensation body

17

Interconnect point

18

Point

19

Axle

20

oh near inside

21

oh-far exterior

22

Connecting piece

23

Adjusting path

24

Light dark border