CN107588395B

CN107588395B - Multi-part reflector for a light module of a motor vehicle headlight

Info

Publication number: CN107588395B
Application number: CN201710549358.3A
Authority: CN
Inventors: A·迈尔; S·布劳恩; C·奥托; E-O·罗森汉; R·洛伊特; M·比德尔曼; E·辛格
Original assignee: Automotive Lighting Reutlingen GmbH
Current assignee: Marelli Automotive Lighting Reutlingen Germany GmbH
Priority date: 2016-07-08
Filing date: 2017-07-07
Publication date: 2022-02-11
Anticipated expiration: 2037-07-07
Also published as: EP3270043B1; DE202016103680U1; EP3270043A1; EP3270043B9; CN107588395A

Abstract

The invention relates to a light module of a motor vehicle headlight, comprising a reflector, a heat sink and a circuit board with semiconductor light sources, wherein the reflector comprises a support shell made of a first material and a reflector shell made of a second material, which rests on the support shell, wherein the reflector shell and the circuit board have positioning structures which are complementary to one another and engage into one another, and wherein the support shell is thermally coupled to the circuit board by means of a suitable connection.

Description

Multi-part reflector for a light module of a motor vehicle headlight

Technical Field

The invention relates to a light module of a motor vehicle headlight, comprising a reflector, a heat sink and a printed circuit board with semiconductor light sources. Such light modules are known per se.

Background

Today, reflectors are usually made of plastic (e.g. thermoset, thermoplastic) or of a metallic material (e.g. aluminium). These materials are typically surface treated to meet optical requirements.

The surface precision to be achieved depends inter alia on the type of surface treatment, which has to be taken into account when designing the light module. Expensive manufacturing tools (e.g. painting equipment) are required today to prepare the reflector blanks for the final surface treatment. A process window must be set for this and the maintenance of the process window must be monitored in order to detect and limit quality fluctuations. Depending on the material used, there are restrictions on the shape of the component (due to the mold technology required for the production), for example shrinkage depressions which occur as a result of shrinkage on cooling of the cast reflector, inaccuracies as a result of geometric distortions, flash formation, etc.

Due to the tolerances of the components themselves and tolerances determined by the components, what should be taken into account when designing the efficiency loss of the entire system leads to an increase in cost and complexity.

Depending on the material, the reflector stiffness that needs to be achieved is significantly different and in the past has caused significant problems. The required quality of the optical surface to be achieved in turn greatly limits the achievement of mechanical stability of the reflector.

Furthermore, one or more additional elements are often required to remove the generated thermal energy and/or to perform mechanical fastening. For heat dissipation, efficiency is certainly deteriorated by the transmission technique. More costs are required due to increased material usage.

Disclosure of Invention

On this basis, it is an object of the present invention to provide an optical module which does not have these disadvantages or at least does so to only a small extent in any case.

This object is achieved by the features of claim 1. The light module according to the invention is characterized in that the reflector has a support shell made of a first material and a reflector shell made of a second material, which rests against the support shell, wherein the reflector shell and the circuit board have positioning structures which are complementary to one another and engage into one another, and wherein the support shell is thermally coupled to the circuit board by means of a suitable connection. Suitable connections are preferably threaded or riveted connections.

By this feature, a light module is provided which at the same time is very precise and can withstand mechanical loads with less material investment than in the prior art. The optical module according to the invention has an optimized efficiency and is also characterized by a reduced installation space requirement. In this context, efficiency is understood to mean a luminous flux which is standardized for the luminous flux of the light source and which is emitted by the light module in a solid angle of light distribution which is satisfactory for a motor vehicle.

The modular construction allows for the combination of multiple beneficial properties of a single substance for each component of the light module, thereby providing an efficient, cost-effective component with a high degree of shape accuracy that provides the required surface quality without the need for expensive and complex (reduced mass) subsequent processes. The modular construction offers the advantage that the tolerance chain within the light technology system of the light module is reduced. Another advantage is that the total weight of the light module can be reduced. Reducing capital constraints by eliminating mechanical equipment in manufacturing is achieved due to the elimination of multiple process steps in the manufacturing process to achieve the desired surface accuracy in a one-piece reflector. The lower material requirement possible reduces the installation space required for installation in the headlamp.

It is also preferred that the semiconductor light source has at least one light-emitting diode or laser diode or a region of a light-emitting diode or laser diode.

It is also preferred that the basic substance of the first material is a light metal such as aluminum or magnesium, or an alloy containing at least one of the light metals.

A further preferred embodiment is characterized in that the second material is a plastic.

It is also preferred that the supporting housing of the reflector in the light module is fixed to the swinging frame of the light module by means of suitable fixing elements, preferably by means of screws.

It is also preferred that the reflector housing is clamped and thereby fixed between the circuit board and the support housing.

A further preferred embodiment is characterized in that the surface-increasing structure has a rib shape in order to be able to discharge heat into the surroundings.

It is also preferred that the reflective casing and the circuit board have locating formations that are complementary to and engage into each other.

It is also preferred that the positioning structure is a projection in the reflector hood which engages without play into a recess of the circuit board corresponding thereto, i.e. matching the dimensions, or a projection on the circuit board which engages without play into a recess of the reflector hood matching the dimensions thereof.

A further preferred embodiment is characterized in that similar or identical positioning structures are also provided on or in the circuit board on its side facing the support shell and in or on the support shell, and are dimensioned such that they engage into one another without play.

It is also preferable that the support housing has, at its light exit side end portion, a protrusion portion that protrudes into an inner diameter of an opening of the light exit side end portion.

It is also preferred that the support housing has at least two such projections, one of which projects into the opening from the right and one from the left, and forms a stop in the lateral direction and a stop in the light exit direction perpendicular to the lateral direction.

A further preferred embodiment is characterized in that the support housing and the reflector housing are advantageously shaped and dimensioned to be adapted to one another in such a way that a convex rear side of the reflector housing facing away from the light exit side thereof is accommodated in a fitting manner precisely and without play by the concave surface of the support housing.

Further advantages emerge from the dependent claims, the description and the drawings.

It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or individually without departing from the scope of the present invention.

Drawings

Embodiments of the invention are illustrated in the drawings and set forth in detail in the following description. In this respect, the same reference numbers in different figures denote identical or at least functionally identical elements, respectively. Wherein, schematically shown:

fig. 1 shows a pivot frame of a motor vehicle headlight, viewed from diagonally behind, with a light module according to the invention;

FIG. 2 shows the subject of FIG. 1 from an oblique front;

fig. 3 shows a vertical section parallel to the main illumination direction in the middle of the light module, which particularly shows the fixation of the light module on the swing frame;

fig. 4 shows a cross-section of the light module parallel thereto, which cross-section is at the level of the fixing screws by means of which the circuit board is connected with the reflective housing and the support housing; and

fig. 5 shows a cross-section of a light module near a second side edge of the light module.

Detailed Description

Fig. 1 and 2 show a pivot frame 1 of a motor vehicle headlight in detail, which is a component of an exemplary embodiment of a light module 10 according to the present invention. In this regard, fig. 1 shows a perspective view of the rear side of the swing frame 1 and the optical module 10, and fig. 2 shows a perspective view of the front side of the swing frame 1 and the optical module 10.

In the exemplary embodiment shown, the pivot frame 1 has a cylindrical bearing pin 2, a ball bearing pin 3 and a ball bearing pin receptacle 4. The

bearing pins

2, 3 and the receptacles form a joint arrangement, by means of which the pivot frame is pivotably mounted in the housing of the motor vehicle headlight when it is conventionally used in motor vehicle headlights. The barrel bearing pin 2 defines with the ball bearing pin 3 a pivot axis for the illumination width adjustment, and the ball bearing pin 38 defines with the receptacle 40 a pivot axis for the turn light function. For the purposes of the invention, the

pins

2, 3 and the receptacles 4 are not critical and are only mentioned here for a better understanding of the illustrated embodiment.

In conventional use, the x-direction is generally parallel to the longitudinal axis of the vehicle, the y-direction is generally parallel to the transverse axis of the vehicle, and the z-direction is generally parallel to the vertical axis of the vehicle.

The light module 10 has a support housing 12, a reflector housing 14 and a circuit board 16 and is rigidly connected to the pivot frame 1 in the illustrated embodiment by suitable connections. Suitable connections are preferably threaded connections or riveted connections.

Fig. 2 shows the body of fig. 1 from obliquely above, so that the reflecting surface 18 of the reflective casing 14 can be seen. In the embodiment shown, the reflector housing 14 has two reflector chambers, but this is not essential to the invention. The reflector of the light module 10 according to the invention may also have only one or more than two reflector cavities.

The circuit board 16 is also visible in fig. 1 and 2. One semiconductor light source 20 for each reflector chamber can be seen on the side of the circuit board 16 visible in fig. 2 (which faces the reflection surface 18). Each semiconductor light source 20 has at least one light emitting diode or a laser diode or a region of light emitting diodes or laser diodes.

A screw hole (Schraubendohme)22 opened forward in fig. 2 is used, for example, to screw the light shielding plate unit and/or the lens fixing unit to the swing frame 1 of the optical module 10. The shading plate unit is used in particular for generating a light-dark boundary of the low beam distribution. In this embodiment, the light module according to the invention is a component of a so-called projection light module, which maps the mask edge of the mask to a sharp light-dark boundary. However, the light module can also be a direct-mapped light module, in which the reflector generates the light distribution directly from the light of the light source, without a further optical element in the form of a lens or a further reflector of the light beam emitted from the reflection surface being required for this purpose.

A closed threaded mouth 24 visible in the upper half of the swing frame 1 is used to receive a screw for screwing the support shell 12 to the swing frame 1.

A closed threaded mouth 25 visible in the lower half of the swing frame 1 is used to accommodate screws for fixing another light module (for example a high beam module) and a second reflector on the swing frame 1.

Fig. 3 to 5 show vertical cross-sections, or in the case of fig. 5 a part of the vertical cross-section of the body of fig. 1 and 2.

In this regard, fig. 3 shows a sectional view in fig. 1 approximately in the middle of the light module 10 in the y direction and parallel to the x-z plane, in particular the fixing of the support shell 12 on the pendulum frame 1.

Fig. 3 shows, in particular, the support housing 12 with the reflective housing 14 and the circuit board 16 with the semiconductor light source 20. The semiconductor light source 20 is a light emitting diode, a region composed of a plurality of light emitting diodes, a laser diode, or a region composed of a plurality of laser diodes.

The support housing 12 is made of a first material and the reflective housing 14, which rests against the support housing 12, is made of a second material. The support envelope 12 and the reflective envelope 14 together form a reflector having a reflective surface 18.

The basic substance of the first material is preferably a light metal such as aluminum or magnesium or at least one alloy containing the light metal. The basic material is characterized by good mechanical strength and good heat conductivity. The surface of which forms a reflector surface or a surface of the light module 10 that is thermally efficient, i.e. absorbs heat and is discharged to the environment. The efficiency of the overall system, which is referred to herein as the efficiency of heat dissipation from the heat source and the circuit board, is increased by selecting the base material for the thermally efficient surface.

The second material is for example plastic. The plastic material then forms the basic material of the optically active reflection surface 18. By selecting the base substance, no subsequent processes, such as painting, are required. All allow in particular to distribute the component functions to different substances, avoiding the drawbacks determined by systems with reflectors made of only one material, which in the prior art have to fulfil the mechanical, thermal and optical functions.

Plug elements 26 arranged on the circuit board 16 serve for electrical contacting and energy supply of the semiconductor light sources 20. The supporting shell 12 of the reflector is fixed in the light module 10, for example on the swinging frame 1 of the light module 10, by means of screws 28.

Fig. 4 shows a cross-section of a light module 10 according to the invention, which extends parallel to the x-z plane and is situated approximately at the level of a fixing screw or a threaded opening 32 accommodating the screw, by means of which the circuit board 16 is connected to the reflector housing 14 and the support housing 12. Fig. 2 shows, in particular, a threaded opening 32 as a component of the support housing 12 and a recess 34 in the circuit board 16. The circuit board 16 is mechanically fixed to the support housing 12 by screwing in and tightening screws inserted through the recesses into the threaded openings 32. In this regard, the reflector housing 14 is clamped and then secured between the circuit board 16 and the support housing 12.

In addition to the fastening effect, a thermal coupling is also obtained between the semiconductor light source 20, the circuit board 16 and the support housing 12, by means of which heat generated in the semiconductor light source 20 is conducted from the circuit board 16 into the support housing 12, which preferably also serves as a heat sink.

In order to dissipate heat to the environment, the support housing 12 preferably has an enlarged-surface structure 36 on its rear side facing away from the reflector housing 14. The surface enlarging structures 36 preferably have a rib shape in order to be able to discharge heat to the environment. The ribs preferably extend parallel to the x-z plane. By means of this arrangement, better heat dissipation from the light-emitting diode is achieved. This alternative shape to the pin-shaped cooling structure provides the advantage of also having an additional stiffening effect, which allows the use of a light supporting envelope 12 using relatively little material.

In addition to the molded reinforcing structure 36, the support housing 12 has a fixing element 38 for fixing the circuit board 16. In the illustrated embodiment, the fastening element 38 is a threaded opening 32.

Fig. 5 shows a cross-section of a light module 10 according to the invention parallel to the x-z plane and located in the vicinity of a side edge of the light module 10 in the y-direction. In the case of fig. 5, the side edge is the left edge of the light module 10 in fig. 1. The reflector housing 14 and the circuit board 16 have complementary and mutually embedded

detent structures

38, 40, which are cut by the cutting plane of fig. 5.

Preferably, there are additional positioning geometries. It is particularly preferred that this or a similar positioning geometry is also arranged near the right edge of the light module 10.

The

positioning structures

38, 40 secure the circuit board 16 and in particular the semiconductor light sources 20 arranged on the circuit board 16 relative to the reflector 12, which is composed of the supporting envelope 12 and the reflecting envelope 14, with a precision defined by the manufacturing precision of the

positioning structures

38, 40. The positioning structure is preferably a projection 38 in the reflector housing 14, which engages without play into a recess 40 of the circuit board 16 corresponding to the projection, i.e. matched in size. Conversely, the positioning structure can also be a projection on the circuit board 16, which engages without play into a recess of the reflector casing 14, which recess is matched to the dimensions of the projection.

Similar or identical positioning structures are also preferably arranged in or on the circuit board 20 on its side facing the support housing 12 and in or on the support housing 12. The positioning structures engage into one another without play, so that the support housing 12 is fixed with high precision relative to the circuit board 16 and thus relative to the light source 20.

Such a positioning structure is also preferably arranged in the vicinity of the left edge of the light module in fig. 1.

Fig. 2 shows that the support housing 12 has, on its light exit-side end, a projection 44 which projects into the inner diameter of the opening of the light exit-side end. Each such projection 44 forms a stop for the light exit side edge of the reflector housing 14 when the reflector housing 14 is inserted into the support housing 12. Preferably, the support housing has at least two such projections 44, one of which projects into the opening from the right and one from the left and forms a stop in the lateral direction (y-direction and counter-direction) and a stop in the light exit direction (x-direction).

In the present invention, the supporting shell 12 and the reflector shell 14 are shaped and dimensioned to be adapted to one another such that the convex rear side of the reflector shell 14 facing away from the light exit side thereof is accommodated in a precisely fitting manner and without play, preferably with a low pre-tension, by the concave surface of the supporting shell.

This connection of the reflector housing 14, the circuit board 16 to the light source 20 and the support housing 12 can reduce the tolerance chain within the light engineering system.

Claims

1. Light module (10) of a motor vehicle headlight, comprising a reflector, a heat sink and a circuit board (16) having semiconductor light sources (20), wherein the reflector comprises a supporting shell (12) made of a first material and a reflecting shell (14) made of a second material and attached to the supporting shell (12), wherein the reflective casing (14) and the circuit board (16) have positioning structures that are complementary to each other and engage into each other, and wherein the support housing (12) is thermally coupled to the circuit board (16) by a suitable connection, characterized in that the supporting shell (12) and the reflecting shell (14) are shaped and dimensioned to match each other, so that the convex rear side of the reflective coating (14) facing away from the light exit side thereof is received in a fitting manner precisely and without play by the concave surface of the support coating (12).

2. The light module (10) according to claim 1, characterized in that the semiconductor light source (20) has at least one light emitting diode or laser diode or a region of light emitting diodes or laser diodes.

3. Optical module (10) according to claim 1 or 2, characterized in that the basic substance of the first material is a light metal or an alloy comprising at least one of said light metals.

4. The light module (10) according to claim 3, characterized in that the light metal is aluminum or magnesium.

5. The light module (10) according to claim 1 or 2, characterized in that the second material is plastic.

6. Light module (10) according to claim 1 or 2, characterized in that in the light module (10) the supporting housing (12) of the reflector is fixed by means of suitable fixtures on the swinging frame (1) of the light module (10).

7. The light module (10) according to claim 1 or 2, characterized in that the reflective enclosure (14) is clamped and in turn fixed between the circuit board (16) and the support enclosure (12) or also fixed in the reflective enclosure.

8. The light module (10) according to claim 1 or 2, characterized in that the support housing (12) has an enlarged-surface structure (36) on its rear side facing away from the reflective housing (14).

9. The light module (10) according to claim 8, characterized in that the surface increasing structure (36) has a cooling rib shape or a pin shape.

10. The light module (10) according to claim 1 or 2, characterized in that the reflective casing (14) and the circuit board (16) have positioning structures (38, 40) complementary to each other and engaging into each other.

11. The light module (10) according to claim 10, characterized in that the positioning structure is a projection (38) in the reflector housing (14) which engages without play into a corresponding, i.e. size-matched, recess (40) of the circuit board (16) or a projection on the circuit board (16) which engages without play into a size-matched recess of the reflector housing (14).

12. The light module (10) according to claim 11, characterized in that the same positioning structures are also provided on or in the circuit board (16) on its side facing the support housing (12) and in or on the support housing (12) and are dimensioned such that they engage into one another without play.

13. The light module (10) according to claim 1 or 2, characterized in that the support housing (12) has, at its light exit side end, a protrusion (44) that protrudes into the inner diameter of the opening of the light exit side end.

14. The light module (10) according to claim 13, characterized in that the support housing has at least two such projections (44), one of which protrudes from the right side and one from the left side into the opening and forms a stop in the lateral direction and a stop in the light exit direction perpendicular to the lateral direction.

15. Light module (10) according to claim 1 or 2, characterized in that the suitable connection is a threaded connection or a riveted connection.