Method for injection molding a light technology module for a lighting device of a motor vehicle

Abstract

The invention relates to a method for producing a light technology module (100) for a lighting device of a motor vehicle, wherein the module (100) comprises a support part (1) and a light outcoupling part (2). According to the invention, a connecting body (3) for establishing a retaining connection between the support part (1) and the light outcoupling part (2) is at least injection-molded onto the support part (1) by means of an injection molding method.

Description

Technical Field

[0001] The invention relates to a method for producing a lighting module for a lighting device of a motor vehicle, wherein the module has a metallic support component and a light outcoupling component. Background Art

[0002] Optical modules for light output coupling in motor vehicle lighting devices usually include a support part, in particular in the form of a frame, and a light output coupling part, such as a lens or a lens array or a light guide element, received thereon. In modules for light output coupling, in the prior art, a holding connection is usually formed between the light output coupling part and the support part by bonding or laser welding. In the case of bonded modules, the support part is preferably made of metal or a thermosetting plastic material, for laser welded modules, thermoplastics are used differently, but they have poorer thermomechanical properties than metals or many thermosetting plastics. The light output coupling part is usually made of transparent thermoplastics. In the construction of modern motor vehicle lighting devices (especially in the case of headlights), an important methodological challenge is the precise alignment of all optical modules (such as light sources, reflectors, light guides and light output coupling devices) relative to each other and to the receiving device fixed to the vehicle. Due to the manufacturing tolerances of the individual components and the tolerances when joining the individual components to the module, a long tolerance chain is generated, so that it is often impossible to directly refer to the light source when installing the various modules. Therefore, in the prior art, part of the connection and installation steps is carried out under active alignment, i.e. the light impression produced by the lighting device is observed in situ on the projection surface and optimized as required during the adjustment of the components or modules. This sequential, complex installation and adjustment process is disadvantageously very lengthy and is accompanied by a high level of personnel involvement and investment in the installation device. Summary of the invention

[0003] The object of the present invention is therefore to provide a method for producing a light module for a lighting device of a motor vehicle, by which a light module can be produced with high tolerance quality and in particular with a low-tolerance connection between a carrier element and a light outcoupling element.

[0004] This object is achieved by the method according to the invention.

[0005] The present invention includes the following technical teaching: at least a connecting body for forming a holding connection between a support component and a light outcoupling component is injection-molded onto the support component by an injection-molding method.

[0006] The idea of ​​the invention is to replace the conventional adhesive bonding or laser welding processes used in the prior art for joining support and light coupling-out components by injection molding processes with significantly lower tolerances. This allows for a separate adjustment step to be omitted when constructing the module, in which the light coupling-out component and support component are actively aligned, if necessary, even under illumination. Furthermore, the high precision of the injection molding ensures a targeted positioning of the two components relative to one another, which is fixed by the injection-molded connecting body when a retaining connection is formed.

[0007] In a first embodiment of the method according to the invention, a support part and a light outcoupling part are provided and placed in an injection mold, wherein a connecting body is then injection molded onto the support part and the light outcoupling part to form a retaining connection. The two parts to be connected, for example a support part as a purposefully shaped sheet metal part and a light outcoupling part made of glass or in particular transparent plastic, are provided separately and received in the injection mold in their intended relative positioning. Injection molding results in a retaining connection of the two parts via the injected connecting body, which in particular forms a positive connection with each of the two parts.

[0008] In an alternative embodiment, only the support part is provided and placed in the injection mold, wherein the connecting body is then injection molded onto the support part to form the holding connection, and the light outcoupling part is injection molded as a section of the connecting body. In this case, the light outcoupling part is therefore produced as an injection-molded component only during the injection molding process, i.e., in particular together with the connecting body and as a section thereof. The connecting body and the light outcoupling part are preferably constructed in one piece and of the same material.

[0009] Injection molding of the connector and / or the light coupling-out component can be performed in one cycle or in multiple cycles. For example, if the light coupling-out component is a thick-walled lens with high requirements on optical quality, at least two injection molding cycles may be required.

[0010] Preferably, a support component and / or a light outcoupling component are provided, each having at least one connecting section, wherein the connecting section is encapsulated by a connecting body while forming a positive fit to form a holding connection. Preferably, the holding connection of the two components is arranged close to the main light-technical function, i.e., close to the light outcoupling, so that in the event of thermal expansion during operation of the lighting device, the relative position changes of the components are kept small by a very short lever. The connecting section on the light outcoupling component can be designed, for example, as a circumferential flange.

[0011] It is particularly advantageous to provide a connection section of the support component and / or the light outcoupling component with at least one undercut and / or with at least one opening. This serves to form a positive connection with the injection-molded connecting body. In particular, this is necessary when using a metal support component in order to ensure a loadable and permanent connection with the connecting body injection-molded from plastic. For example, the undercut microstructure can be produced on the metal surface of the support component by laser processing, electrochemical, wet-chemical or mechanical treatment.

[0012] Furthermore, it is advantageous if, during the injection molding of the connector, at least one reference element is injection molded onto the module for reference association on the lighting device. Due to the high precision and reproducibility of the injection molding method, a high tolerance quality of the reference of the assembly with respect to the component to be contacted, for example, a support frame of the lighting device, can be produced. In particular, this opens up the possibility of direct reference of the light outcoupling module with respect to the light source, thereby avoiding the complex process of active alignment of the assembly with respect to one another.

[0013] For example, a support component is provided with at least one hole, wherein the hole is overmolded to form the reference element. The opening thus remaining is precisely defined in diameter and position and is suitable, for example, for receiving a screw or a pin. Alternatively or additionally, a reference element in the form of a pin can be injection molded.

[0014] In a special embodiment of the method according to the invention, the light outcoupling element is provided or injection-molded in the form of a lens.

[0015] Furthermore, in a further advantageous embodiment, a connecting body is injection-molded with at least one cover segment, wherein the cover segment at least partially surrounds the support part. As a result, the connecting body performs an additional design function and conceals such a section of the in particular metallic support part which is visible outside the provided lighting device. In particular, a desired color impression can be achieved by selecting a colored plastic. Preferably, the cover segment has no additional form-locking connection points to the support part in order to decouple the corresponding thermal expansion movements as much as possible from one another.

[0016] Furthermore, the invention relates to a lighting module for a lighting device of a motor vehicle, wherein the module comprises a support element and a light outcoupling element and wherein the module is produced by a method according to one of the above-described embodiments of the invention.

[0017] Preferably, the support part of the module comprises a metal and / or a metal alloy. Compared with plastics, metals are characterized by their superior mechanical and thermomechanical properties. When the method according to the invention is implemented, the connection between the metal support part and the light outcoupling part is ensured by the connector while forming a positive fit. In particular, the support part can advantageously comprise an aluminum alloy, for example an aluminum-magnesium alloy. The advantages of aluminum alloys are their low specific weight and low thermal expansion coefficient.

[0018] It is also advantageous if the connector and / or the light outcoupling element comprises a thermoplastic. Thermoplastics are inexpensive, can be easily injection molded and are suitable for optical applications in a transparent material. Preferably, the connector and / or the light outcoupling element comprises polycarbonate and / or polymethyl methacrylate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In addition, other measures for improving the present invention are described in more detail below in conjunction with the accompanying drawings together with the description of the preferred embodiments of the present invention. In the accompanying drawings:

[0020] Figure 1a shows a cross-sectional view of a first module according to the present invention;

[0021] Figure 1b shows a cross-sectional view of a second module according to the present invention;

[0022] Figure 2 A cross-sectional view of a third module according to the invention is shown. DETAILED DESCRIPTION

[0023] Figure 1a , 1b 2 show cross-sectional views of three different embodiments of a light technology module 100 according to the invention. The modules 100 each comprise a support component 1 having a connection body 3 injection-molded on a connection section 11, which forms a holding connection between the support component 1 and a light outcoupling component 2. The three-dimensional shape of the support component 1 is essentially rotationally symmetrical about a longitudinal axis, and the light outcoupling component is each designed as a lens 20. The support component 1 is preferably made of a lightweight aluminum alloy.

[0024] Figure 1a and 1b The module 100 shown is produced according to an embodiment of the method according to the invention, wherein both the support part 1 and the light outcoupling part 2 are provided as prefabricated components and are placed in the injection mold used in a targeted orientation relative to one another. Then, in a subsequent injection molding process, the connecting body 3 (e.g., made of thermoplastic) is injection molded to form a retaining connection between the support part 1 and the light outcoupling part 2.

[0025] The connecting body 3 here forms a positive connection with the corresponding connecting sections 11, 21. The connecting section 11 extends in particular over the entire circumference along the end section of the support part 1 shown at the top of the figure and has openings 12 spaced apart from each other on the circumference, which are injection-molded in a positively locking manner by the connecting body 3. Additionally or alternatively, the surface of the connecting section 11 can be at least partially provided with a surface structure with undercuts in order to further strengthen the connection between the support part 1 and the connecting body 3. On the side of the light outcoupling component 2, a connecting section 21 is constructed in the form of a flange that is particularly circumferentially circumferential in order to form a tongue-and-groove connection with the connecting body 3. The light outcoupling component 2 is formed, for example, from optical glass, but usually from a transparent thermoplastic, wherein the connecting body 3 is preferably formed from the same plastic in order to optimize the thermomechanical properties of the connection.

[0026] exist Figure 1b In the embodiment of the module 100 shown, the connecting body 3 also has a cover section 31, which fulfills a design function of the connecting body 3 as an outer cover of the support part 1. This can be achieved in particular by using a correspondingly colored plastic to produce the connecting body 3, and is expedient when the support part 1 is visible from the outside in the lighting device provided. Preferably, no form-fit connection is formed between the support part 1 and the cover section 31, so that no undesirable interaction occurs during thermal expansion.

[0027] Figure 2 The module 100 shown is manufactured according to a second variant of the method of the invention, wherein only the support part 1 is provided as a prefabricated component and is placed in the injection mold used. The light outcoupling part 2 is formed as a section of the connecting body 3 during subsequent injection molding, wherein the connecting body 3 forms a positive locking holding connection of the type described with the support part 1. The light outcoupling part 2 is constructed in this case with the same material as the rest of the connecting body 3 and can be injection molded in one or more cycles depending on the thickness of the lens 20 or the required optical quality. For example, in multi-cycle injection molding, a punch that is movable in the injection mold can be used.

[0028] All modules shown in the three figures include a reference element 4, which is used for reference on the lighting device and is injection-molded onto the support part 1 along with the injection molding of the connecting body 3. For this purpose, a support part 1 with holes 14 is provided and these holes are formed as shown in FIG. Figure 2 The dimensions shown are precisely encapsulated and injection molded to form the reference element 4 or as shown Figure 1a and 1b The illustrated example is for an injection-molded pin 40. The reference element 4 is used during the installation of the module 100 in the associated lighting device for reference, for example on a support frame or directly on the light source.

[0029] Due to the precision and reproducibility of the injection molding method used for forming the retaining connection between the support part 1 and the light output coupling part 2 and for forming the reference element 4, the optical technology module 100 according to the present invention has a high tolerance quality and can therefore significantly simplify the installation and adjustment process when constructing the relevant motor vehicle lighting device.

[0030] The invention is not limited to the preferred embodiments described above in its implementation. On the contrary, various variants are conceivable, which can use the proposed solution even if the type of implementation is different in principle. All features and / or advantages from the claims, the description or the drawings (including design details, spatial arrangements and method steps) may be important to the invention per se and in various combinations.

[0031] Reference numerals list

[0032] 100 modules

[0033] 1 Support components

[0034] 11 Connection section

[0035] 12 Opening

[0036] 14 holes

[0037] 2 Light output coupling components

[0038] 20 Lens

[0039] 21 Connection section

[0040] 3 Connector

[0041] 31 Guard section

[0042] 4 Reference components

[0043] 40 Pins

Claims

1. A method for producing a light module (100) for a lighting device of a motor vehicle, wherein: The module (100) comprises a support component (1) and a light output coupling component (2), and is characterized in that a connecting body (3) for establishing a retaining connection between the support component (1) and the light output coupling component (2) is at least injection-molded onto the support component (1) by means of an injection molding method, and the connecting body (3) is injection-molded with at least one cover plate section (31), wherein the connecting body (3) and the cover plate section (31) of the connecting body directly contact and surround most of the outer surface of the support component (1) to form an outer cover portion of the support component (1).

2. The method according to claim 1, characterized in that: A support component (1) and a light output coupling component (2) are provided and placed in an injection molding mold, wherein a connecting body (3) is then injection molded onto the support component (1) and the light output coupling component (2) to form the retaining connection.

3. The method according to claim 1, characterized in that A support component (1) is provided and placed in an injection molding tool, wherein a connecting body (3) is then injection molded onto the support component (1) to form the holding connection, and a light outcoupling component (2) is injection molded as a section of the connecting body (3).

4. The method according to claim 3, characterized in that The injection molding of the connecting body (3) and / or the light outcoupling element (2) is performed in one cycle or in a plurality of cycles.

5. The method according to any one of claims 1 to 4, characterized in that A support component (1) and / or a light outcoupling component (2) each having at least one connecting section (11, 21) is provided, wherein the connecting section (11, 21) is encapsulated by a connecting body (3) to form a positive fit in order to form the retaining connection.

6. The method according to claim 5, characterized in that The connecting section (11, 21) of the support component (1) and / or of the light outcoupling component (2) is provided with at least one undercut and / or at least one opening (12).

7. The method according to any one of claims 1 to 4, characterized in that Along with the injection molding of the connecting body (3), at least one reference element (4) is injection molded on the module (100) for reference association on the lighting device.

8. The method according to claim 7, characterized in that The support part (1) is provided with at least one hole (14), wherein the hole (14) is overmolded to form the reference element (4).

9. The method according to claim 7, characterized in that: Reference element (4) in the form of an injection-molded pin (40).

10. The method according to any one of claims 1 to 4, characterized in that A light outcoupling component (2) in the form of a lens (20) is provided or injection molded.

11. A light module (100) for a lighting device of a motor vehicle, wherein: The module (100) comprises a support component (1) and a light outcoupling component (2), and is characterized in that the module (100) is produced by means of a method according to any one of claims 1 to 10.

12. The module (100) according to claim 11, characterized in that The support component (1) comprises a metal and / or a metal alloy.

13. The module (100) according to claim 12, characterized in that The supporting member (1) comprises an aluminum alloy.

14. The module (100) according to any one of claims 11 to 13, characterized in that The connecting body (3) and / or the light outcoupling element (2) comprise thermoplastic.

15. The module (100) according to claim 14, characterized in that The connecting body (3) and / or the light outcoupling element (2) comprise polycarbonate and / or polymethyl methacrylate.

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