EP3816502A1 - Light module of a motor vehicle headlight and headlight with such a light module - Google Patents

Abstract

A particularly easy-to-assemble and durable light module with very good optical properties is proposed. To this end, it is proposed that a guide be present on a side of a base plate of the bundling optics facing away from the heat sink, that the guide is molded onto the base plate at a first end, that the guide is open at a second end opposite the first end, that in the Guide a screw dome is inserted, and that the screw dome is held in the guide so that it cannot rotate.

Description

The present invention relates to a light module of a motor vehicle headlight. The light module comprises at least one semiconductor light source fastened to a circuit board and with electrical contact and a bundling optics as well as a cooling body on which the board and the bundling optics are fastened. The invention also relates to a motor vehicle headlight comprising a housing and at least one light module arranged therein.

From the DE 10 2017 115 699 A1 a generic light module is known. The optically effective components of a light module (at least one Semiconductor light source and bundling optics) screwed to a heat sink. A self-tapping fastening screw is screwed directly into a base plate of the bundling optics. In order to bind the resulting dust, specially coated screws are required. The use of these special screws is expensive and carries a certain risk of errors. If uncoated screws are installed by mistake, the dust gets onto the bundling optics and worsens the optical properties of the light module or the headlight.

In addition, the tightening torque of the fastening screw must be kept within relatively narrow limits. If the tightening torque is too high, the bundling optics will be deformed and the optical quality will suffer. If the tightening torque is too small, the heat transfer between the semiconductor light source and the heat sink deteriorates. The bundling optics are preferably a reflector. It is preferably made from a thermoset, but can also be made from a thermoplastic or metal.

Starting from the described prior art, the present invention is based on the object of providing a light module that is easy to assemble and has a long service life and has very good optical properties.

To solve this problem, starting from a light module of the type mentioned at the outset, it is proposed that on a side facing away from the heat sink a Base plate of the bundling optics a guide is available that the guide is formed on a first end of the base plate, that the guide is open at a second end opposite the first end, that a screw dome is inserted in the guide, and that the screw dome in the Guide is held in a rotationally fixed manner. In connection with the invention, the term “bundling optics” includes the optical functional element, such as a reflector, and the “periphery”, such as a base plate and the guide for the screw dome adapter. The guide can be T-shaped in cross section. A screw dome can be easily inserted into the guide. The insertion of the screw dome can be done fully automatically with a handling device or lightweight robot.

Due to the non-rotatable connection between the screw dome and the guide, the torque that occurs when the fastening screw is tightened can be safely introduced into the base plate of the bundling optics without deforming the optically active surfaces of the bundling optics.

By choosing a suitable material for the screw dome and its dimensions in the area of the core hole for the screw hole, it is ensured that the fastening screw does not become loose due to vibrations or other external influences. So there is no need for special coatings on the surface of the screw that have a self-locking effect. Securing the fastening screw against unscrewing the Self-locking is realized according to the invention by the combination of fastening screw and screw dome. A commercially available screw is preferably used as the screw.
When screwing in the screw, there is no dust, rather the core hole in the center of the screw dome deforms plastically (thread grooves) when the fastening screw is screwed in, without chips and dust being created. There is no risk of soiling the bundling optics. All in all, a very reliable joining process is possible.

This joining process is possible with the help of a standard screw, without a dust-binding or self-locking coating. This reduces costs and avoids potential sources of error, such as the use of unsuitable screws. The result is a reliable, process-safe and cost-effective connection between the bundling optics, heat sink and circuit board.

In a preferred embodiment, the guide according to the invention has a prismatic guide profile in a plane running orthogonally to a longitudinal direction of the guide, while the screw dome has a cross-section complementary to the guide profile in a side view. This means that the screw dome can be pushed into the guide at the open end. This results in a form-fitting and non-rotatable connection between the screw dome and the guide.

A particularly advantageous design of the guide provides that the guide has a T-shaped cross section or has the shape of a C profile in a plane which runs orthogonally to the longitudinal direction of the guide. Such C-profiles are known as so-called "Halfen" rails from trade fair and metal construction. According to the invention, the advantages of this C-profile can also be used when connecting the circuit board, bundling optics and heat sink of a light module.

The screw dome advantageously has an elongated base body, a guide plate being formed at each end of the base body, and a width B of the guide plates corresponding to a clear width lW of the guide profile. This means that the screw dome creates a complementary and non-rotatable connection to the guide as soon as it has been pushed into the guide profile of the guide with the guide plates.

The screw dome according to the invention is also very light and thin-walled; There are no larger accumulations of material. This simplifies the manufacture of the screw dome and minimizes costs. When the screw dome is manufactured by injection molding of plastic, small wall thicknesses are not only desirable because of the savings in material, but also the removal times from the mold are shorter if the wall thicknesses of the injection-molded component are as small as possible. This reduces the piece times and increases the number of pieces, all other things being equal. The inventive design is the Screw dome is very strong and resilient despite the small wall thickness and the low use of material. It can safely absorb the forces introduced by the screws.

In order to ensure the locking or fixing of the screw dome in the guide and relative to the base plate of the bundling optics, a projection can be formed at one end of the screw dome which interacts positively with a complementary recess in the baseplate of the bundling optics as soon as the screw dome is relative to the base plate has reached the desired position. This construction can of course also be reversed in that a projection is provided on the underside of the base plate of the bundling optics and a complementary recess is formed at one end of a screw dome.

The screw dome has reached the (end) position when the core hole of the screw dome lies in the extension of an opening in the base plate of the bundling optics. The fastening screw is inserted through this opening and screwed into the core hole in the screw dome. It is therefore obvious that the opening and the hole in the screw dome must be aligned in order to enable the fastening screw to be screwed in.

The screw dome is preferably made of a thermoplastic material. In particular, fiber-reinforced polybutylene terephthalate PBT-GF 10 has proven to be particularly suitable.

In order to enable the automated assembly or the joining of the screw dome with the guidance of the bundling optics, a rib is formed between the guide plates in a preferred embodiment. This rib enables the screw dome to be gripped in a defined position with the aid of a lightweight robot or some other gripper. When the screw dome has been gripped in this defined position, the screw dome is automatically pushed into the guide of the bundling optics until the screw dome and bundling optics lock together with the aid of the above-mentioned projections and depressions.

By reducing the complexity of the process of joining the circuit board, bundling optics and heat sink, it can be carried out fully automatically and with a very low error rate. This is of considerable importance in particular against the background of the very large quantities achieved in motor vehicle construction and the constantly increasing cost pressure on the part of motor vehicle manufacturers.

The heat sink is made of sheet metal that is suitably bent into a certain three-dimensional shape. In this context, suitable means that the heat sink, on the one hand, can efficiently dissipate the heat given off by the at least one semiconductor light source during operation of the light module and dissipate it to the environment, thus overheating the light source (s), even with long-term operation of the light module can be effectively and safely prevented at full power and even at high outside temperatures. Also means in a suitable manner that all optically effective components, in particular the at least one semiconductor light source and the bundling optics, can be attached to the heat sink.

According to an advantageous development of the invention, the focusing optics comprise a reflector, in particular a half-shell reflector. The reflector as an optical functional element of the bundling optics serves to bundle the light from the semiconductor light source (s) and deflect it into a light exit direction of the light module, if necessary in cooperation with an auxiliary optics arranged in the beam path of the light emitted by the at least one semiconductor light source. The semiconductor light source (s) is / are arranged relative to the reflector in such a way that their main emission direction hits the reflection surface. The reflector is preferably formed approximately parabolic in a longitudinal section which includes the main emission direction of a semiconductor light source and the light exit direction of the light module.

According to a preferred embodiment, the at least one semiconductor light source comprises a light emitting diode (LED) or laser diode. Several LEDs can be arranged one above the other and / or next to one another in the manner of a matrix, so that they form an LED array. The LEDs of a semiconductor light source can be controlled individually, in groups or all together.

According to a preferred embodiment, the movable section of the sheet metal part can be moved relative to the fixed section of the sheet metal part by means of at least one adjusting screw and can be fixed in an adjusted position relative thereto.

The adjustment screw or its shaft preferably has a longitudinal extension in the adjustment direction of the optically effective components of the light module, in particular in the vertical z-direction of the light module. According to a particularly preferred embodiment of the invention, the at least one adjusting screw is passed through a (preferably threadless) opening in the movable section of the sheet metal part and screwed into a threaded hole in the fixed section of the sheet metal part or a component attached to it (e.g. carrier element or headlight housing).

By tightening or loosening the adjusting screw, the distance between the movable section and the fixed section of the sheet metal part can be varied until the optical components of the light module that are attached to the movable section are in an adjusted position (position and / or orientation ) are located. The screw is designed to prevent automatic loosening, for example due to vibrations in the motor vehicle, so that the optical components are automatically fixed in this position after reaching the adjusted position. The spring element holds the movable section and thus also the optical components in the adjusted position and prevents vibrations or tremors of the movable section and the optical components.

The invention also relates to a motor vehicle headlight which comprises a housing and at least one light module according to the invention arranged therein. The headlight preferably has several light modules arranged next to one another and attached to a common carrier element, which is fastened to a housing of the headlight in an assembled state of the headlight, which are each individually adjustable relative to one another and with respect to the carrier element and which are jointly adjustable by adjusting the carrier element are adjustable with respect to the housing of the headlight. It would be conceivable, for example, that a light module for generating a spot light of a low beam distribution, another light module for generating a basic light of the low beam distribution and a third light module for generating a high beam distribution is provided by, for example, only providing an area above the horizontal light-dark boundary of the low beam distribution illuminates.

According to the invention, the bundling optics and screw dome adapter are two components. This means that the most suitable material can be selected for both components. As a result, the bundling optics and screw dome adapter therefore consist of different materials.
Further features and advantages of the present invention are explained in more detail below with reference to the figures.

Figur 1

verschiedene Ansichten einer Grundplatte einer Bündelungsoptik eines erfindungsgemäßen Lichtmoduls in einer bevorzugten Ausführungsform;

Figur 2

ein erfindungsgemäßer Schraubdom in einer bevorzugten Ausführungsform;

Figur 3

die Grundplatte gemäß Figur 1 mit eingesetztem Schraubdom gemäß Figur 2; und

Figur 4

einen erfindungsgemäßen Kraftfahrzeugscheinwerfer in einer bevorzugten Ausführungsform.

The features shown in the figures can also be relevant to the invention alone or in a combination other than the one shown. The figures show:

Figure 1

different views of a base plate of a focusing optics of a light module according to the invention in a preferred embodiment;

Figure 2

a screw dome according to the invention in a preferred embodiment;

Figure 3

the base plate according to Figure 1 with inserted screw dome according to Figure 2 ; and

Figure 4

a motor vehicle headlight according to the invention in a preferred embodiment.

In Figure 4 an inventive headlight of a motor vehicle is designated in its entirety with the reference number 1. The headlight 1 is arranged and fastened in a corresponding installation opening in the front area of the body of a motor vehicle.
In detail, the headlight 1 has a housing 2, which is preferably made of plastic. In a light exit direction 3, the housing 2 has a light exit opening 4 which is closed by means of a transparent cover plate 5. The cover 5 is made of glass or plastic. On the cover plate 5, optically effective elements can at least in some areas (z. B. prisms or cylinder lenses) be arranged to scatter the light passing through (so-called diffuser). However, it is also conceivable that the cover plate 5 is designed without such optically effective elements (so-called clear plate).
A light module 6 according to the invention is arranged in the interior of the housing 2. The light module 6 can serve to generate any headlight function or a part thereof. In particular, the light module 6 can serve to generate a low beam distribution, a high beam distribution, a fog light distribution or any adaptive light distribution or a part thereof. Alternatively or additionally, it would also be conceivable that the light module 6 is designed to generate a lighting function, for example a daytime running light, a limiting light and / or a flashing light or a part thereof. At least one further light module 7, which can also be designed as a light module according to the invention, can be arranged in the housing 2. The further light module 7 is used, for example, to generate a further headlight and / or light function or a part thereof.
However, it would also be conceivable that the light modules 6, 7 together generate a provided headlight or lamp function of the headlight 1. For example, the light module 7 could generate a low beam basic light distribution with a relatively wide spread and a strictly horizontal light-dark boundary. The light module 6 could then generate a low beam spot light distribution that, compared to the Low beam basic light distribution of the light module 7 is relatively highly concentrated and has an asymmetrical light-dark border on the top. The asymmetrical light-dark border shows a higher course on the own traffic side than on the opposite traffic side. A superposition of the basic light distribution and the spot light distribution results in a conventional low beam distribution. So that the quality of the low beam is as good as possible, the horizontal light-dark boundary of the basic light and the asymmetrical light-dark boundary of the spot light should be adjusted to each other, especially in the vertical direction, so that they both run at the same height. The present invention proposes a light module 6 in which an adjustment of the light module 6 or the light-dark boundary of a shielded light distribution of the light module 6, in particular in the vertical direction, can be implemented in a simple and inexpensive manner. The light module 6 according to the invention is described below with reference to FIG Figures 1 to 5 explained in more detail.
Of course, it is conceivable that, in addition to the light modules 6, 7, further light modules are arranged in the headlight housing 2, but these are not shown here. In addition, only one light module, for example the light module 6 without the light module 7, can be arranged in the headlight housing 2. Finally, at least one motor vehicle lamp can also be arranged in the housing 2, such as the lamp module 8 shown by way of example. The lamp module 8 is used to generate at least one lamp function, for example one Flashing lights, a position light, a daytime running light, etc.
Further structural details of the light module are, for example, in the DE 10 2017 115 699 A1 by the applicant, which is hereby incorporated by reference. The disclosure of this document is also made into the disclosure of the present application by this reference.

The invention relates to the screw connection of a heat sink with a circuit board and bundling optics. In the Figure 1 a base plate 9 of a bundling optics is shown in different views. The base plate 9 has an opening 10. A fastening screw (not shown) is inserted through the opening 10, with which the heat sink and circuit board are connected.

A guide 12 is integrally formed on an underside 11 of the base plate 9. As already mentioned, the term “bundling optics” includes the optical functional element, such as a reflector 13, and its “periphery”, such as a base plate 9 and a guide 12 for the screw dome adapter.

In the top right of the Figure 1 a view from the front of the base plate 9 with the guide 12 is shown. In this side view, the guide 12 extends perpendicular to the plane of the drawing. The guide 12 has a prismatic cross section which is designed similar to a T-slot.

From the longitudinal section at the top left in the Figure 1 it can be seen that the guide 12 is open at one end, while it is connected to the base plate 9 at the other end. The guide 12 and the base plate 9 are one component and are produced by plastic injection molding or another suitable shaping process. In the open end of the guide profile of the guide 12 is a screw dome, as it is in the Figure 2 is shown, inserted.

From the top view of the base plate 9 (bottom right in the Figure 1 ) there are further geometric properties of the guide 12 according to the invention. Because the guide 12 is located on the underside of the base plate 9, the lines which represent the guide 12 in plan view are shown as broken lines.

A recess 14 is formed on the underside 11 of the base plate, which is used for the screw dome adapter according to FIG Figure 2 to be positively latched and locked in a defined position.

In the Figure 2 an inventive screw dome 15 is shown in a side view and a view from above. The screw dome has a profile that is complementary to the guide 12 in the side view. This means that it can be pushed through the open end into the guide 12 and is thereby positively and non-rotatably connected to the guide 12 or the base plate 9. The Screw dome 15 comprises an elongated or cylindrical base body 16 in the center of which a (core hole) bore 17 is present. A thread-forming or grooving fastening screw is screwed into the bore 17 if the bundling optics are to be screwed to a circuit board and a heat sink.

The diameter of the bore 17 is matched to the fastening screw to be screwed in such that the screw forms an internal thread when it is screwed into the screw dome 15. Essentially, the bore 17 is plastically deformed when the screw is screwed in. However, there remains a certain elastic component that takes on the function of a screw locking device.

At an in Figure 1 The upper end of the cylindrical base body 16 is a first guide plate 18 and a second guide plate 19 is formed on the lower end of the base body 16. The guide plates 18 and 19 are spaced apart and dimensioned in such a way that they can be inserted into the guide profile of the guide 12.

This creates a form-fitting connection between the guide 12 and the screw dome 15, which prevents the screw dome 15 from rotating relative to the base plate 9. In this exemplary embodiment, this is achieved in that a width B of at least one of the guide plates 18 and 19 is matched to a clear width lW of the guide 12.

The same applies to the distance between the guide plates 18 and 19 and the height of the guide 12.

As can be seen from the Figure 2 results, a rib 20 is formed between the guide plates 18 and 19. This rib 20 has several functions. It is used to stiffen the screw dome 15 and can absorb torques that occur during screwing. On the other hand, it is very well suited for automatically gripping the screw dome 15 with the aid of a gripper, for example with the aid of a robot arm, and introducing it in the correct position into the guide 12 of the bundling optics.

This makes it possible to insert the screw dome 15 in the correct position into the guide 12 of the base plate 9 and to establish a form-fitting and rotationally fixed connection between the screw dome 15 and the base plate 9 of the bundling optics.

In the area of the first guide plate 18, a projection 21 is formed which protrudes beyond the first guide plate 18. When the screw dome 15 has reached the correct position in the guide 12, the projection 21 and the recess 14 on the underside 11 of the base plate 9 result in a further form-fitting connection. As a result, the screw dome 15 is locked in the correct position relative to the opening 10 of the base plate 9 of the bundling optics.

The correct position is reached when the longitudinal axis of the bore 17 and the center of the opening 10 in the base plate 9 coincide, so that a screw through the opening 10 can be inserted into the bore 17 and screwed in.

A further form-locking element 22 is formed on the underside of the second guide plate 19. It improves the form fit and the torque transmission between the screw dome 15 and the guide 12.

As a result, the connection between the base plate 9 and the screw dome 15 according to the invention by means of the guide 12 according to the invention can be very resilient and can be joined very easily in an automated manner.

In the Figure 3 the situation is shown that a screw dome 15 according to Figure 2 in the guide 12 according to Figure 1 is used.

The unit consisting of bundling optics and screw dome 15 connected to it in a form-fitting manner can, in a further production step, be very well combined with a circuit board and a heat sink, as it is from the aforementioned DE 10 2017 115 699 A1 is known to be connected by screws.

List of reference symbols

1

Headlights

2

casing

3

Direction of light emission

4th

Light exit opening

5

transparent cover panel

6th

Light module

7th

further light module

8th

Luminaire module

9

Base plate of the bundling optics 13

10

opening

11

bottom

12th

guide

13th

Reflector / optical functional surface of the bundling optics

14th

deepening

15th

Screw dome

16

Base body

17th

drilling

18th

first guide plate

19th

second guide plate

20th

rib

21

Form-fit element

Claims (13)

A light module (6) of a motor vehicle headlight (1), comprising at least one semiconductor light source fastened and electrically contacted on a circuit board and a bundling optics and a cooling body, the circuit board, the bundling optics and the cooling body being screwed together, the cooling body and a base plate (9) of the bundling optics each have an opening (10), characterized in that on a side (11) facing away from the heat sink) on the base plate (9) there is a guide (12) that the guide (12) at a first end to the The base plate (9) is molded so that the guide (12) is open at one of the second end opposite the first end, that a screw dome (15) is inserted in the guide (12) and that the screw dome (15) is in the guide ( 12) is held non-rotatably. Light module (6) according to claim 1, characterized in that the guide (12) has a guide profile in a plane extending orthogonally to a longitudinal direction of the guide (12), and that the screw dome (15) has a cross-section complementary to the guide profile in a side view Has. Light module (6) according to Claim 1 or 2, characterized in that the guide (12) has a T-shaped cross section in a plane running orthogonally to a longitudinal direction of the guide (12). Light module (6) according to claim 2 or 3, characterized in that the screw dome (15) has an elongated base body (16), that a guide plate (18, 19) is formed at each end of the base body (16), and that one Width (B) of the guide plates (18, 19) corresponds to a clear width (lW) of the guide profile (12). Light module (6) according to one of the preceding claims, characterized in that a projection (21) is formed on a first guide plate (18), and that a recess (14) complementary to the projection (21) is provided on the base plate (9) is. Light module (6) according to one of Claims 1 to 4, characterized in that a projection is formed on the base plate (9) and a recess complementary to the projection is provided in a first guide plate (18). Light module (6) according to one of the preceding claims, characterized in that a rib (20) is formed between the guide plates (18, 19). Light module (6) according to one of the preceding claims, characterized in that the screw dome (15) has a bore (17) into which a screw is screwed. Light module (6) according to one of the preceding claims, characterized in that the screw dome (15) consists of a thermoplastic material. Light module (6) according to one of the preceding claims, characterized in that the focusing optics comprise a reflector (13). Light module (6) according to one of the preceding claims, characterized in that the semiconductor light source comprises at least one light-emitting diode or a laser diode. Light module (6) according to one of the preceding claims, characterized in that the bundling optics are made from a thermoset with or without fiber reinforcement, a thermoplastic with or without fiber reinforcement or metal. Motor vehicle headlight (1) comprising a housing (2) and at least one light module (6) arranged therein, characterized in that the light module (6) is designed according to one of Claims 1 to 11.

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