At least partially transparent optical component for use in motor vehicle
The optical components are manufactured by foam injection molding, which solves the problems of insufficient length of material flow paths and many bonding joints in the prior art, and achieves lower material consumption and greater design freedom.
Patent Information
- Application Number
- CN202510293790.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-03-18
- Filing Date
- 2025-03-13
- Publication Date
- 2025-05-13
AI Technical Summary
In the prior art, when manufacturing large-area optical components, it is difficult to achieve high flow path lengths of the material, resulting in visible bonding joints in the finished product, and an increase in material wall thickness will lead to increased material consumption, and the optical components are prone to warping, and the design freedom is limited.
Optical members are manufactured by foam injection molding, which achieves a larger flow path length by reducing melt viscosity, and reduces bonding joints and warping through smaller wall thickness and foam arranged in the interior part, increasing design freedom.
Reduced bonding seams in the functional area, reduced material consumption, reduced warpage, and greater design freedom, making the manufacturing of optical components more cost-effective.
Smart Images
Figure CN119986875A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an at least partially transparent optical component for use in a motor vehicle and to a method for producing such a component. Background Art
[0002] When manufacturing large-area optical components, such as optical lenses, by injection molding, a high flow path length of the material injected into the injection mold must be achieved. This is not easy to achieve in the case of small component thicknesses. On the other hand, due to design and optical technology, it is usually not possible to increase the wall thickness of the component. In addition, the material consumption increases due to the increase in wall thickness. Therefore, when injection molding large-area optical components with small wall thicknesses, multiple injection points are provided for the material to be injected into the injection mold. However, these multiple injection points can lead to visible joints in the finished optical component, which can be located in the functional area of the component. In addition, such components can have a high warpage. Figure 7 This prior art is shown in which an optical component 1 produced by injection molding has a plurality of joining seams 2. Figure 7 In the figure, possible injection points 3 for the material to be injected into the injection mold are also indicated by arrows.
[0003] For specific applications of optical components, such as light guides or ambient lighting, the goal of the light technology design is a uniform light distribution and a diffuse appearance. In the prior art, this is achieved by complex structures or textures introduced into the mold surface of the injection molding mold, which are molded out of the plastic during injection molding. The introduction of such structures into the mold surface of the injection molding mold is complex and cost-intensive. In addition, only very limited design freedom is given with regard to the optical design. Figure 8 An optical component 1 according to the prior art is shown, wherein an optical structure 4 is arranged on the upper boundary surface of the component 1. Light 5 passing through the component 1 is diffusely scattered by the structure 4.
[0004] Another possibility is to use so-called light-scattering materials (light-diffusing materials). In this case, the plastic used for injection molding contains additives that cause light refraction in the finished optical component, thereby creating a diffuse appearance. Fig. 9 An optical component 1 according to this prior art is shown, wherein an additive 6 within the component 1 ensures that light 5 passing through the component 1 is diffusely scattered. Summary of the invention
[0005] The problem underlying the invention is to provide an optical component of the type mentioned at the outset which can be produced cost-effectively and / or has fewer joints in functional areas and / or offers greater design freedom in terms of optical design. In addition, a method for producing such a component should be provided.
[0006] This is achieved according to the invention by an optical component of the type mentioned in the introduction having the features of claim 1 and a method of the type mentioned in the introduction having the features of claim 10. The dependent claims relate to preferred embodiments of the invention.
[0007] According to claim 1, the optical component has a length in a first direction, a width in a second direction perpendicular to the first direction, and a thickness in a third direction perpendicular to the first and second directions, wherein the length and the width are respectively significantly greater than the thickness, wherein the thickness of the component is between 0.4 mm and 4.0 mm, and wherein the component is manufactured by foam injection molding.
[0008] By using foam injection molding, the viscosity of the melt in the injection molding mold can be reduced, so that a greater flow path length can be achieved with fewer injection points and thus fewer weld seams can be achieved in the finished component. The smaller wall thickness or thickness of the component in the third direction that can be achieved by foam injection molding reduces material consumption and leads to more cost-effective production. By foam injection molding, the warping of the component can also be reduced. In addition, the weight of the component can be reduced by the smaller wall thickness and the foam arranged in the inner part of the component.
[0009] It may be provided that the length of the optical component is between 1 cm and 100 cm and / or that the width of the optical component is between 1 cm and 100 cm.
[0010] It is possible that the component has two outer edge layers that lie opposite one another, which extend in a plane formed by the first and second directions and delimit the component in a third direction, wherein the edge layers do not have a foam structure. It can be provided that the two edge layers lie against one another in the third direction, or that a core layer having a foam structure with a plurality of foam cells is arranged between the two edge layers in the third direction.
[0011] One goal here can be to reduce the wall thickness or thickness of the component until the foam expansion is suppressed to such an extent that a light-technically effective structure is produced. When the two edge layers are placed against one another, a very small thickness is produced, wherein additionally no foam structure is present, so that light passing through the component is not scattered at the foam cells.
[0012] It may be provided that the foam cells have a size between 10 μm and 100 μm. In this case, a foam cell with a size of 10 μm is a relatively small cell, while a foam cell with a size of 100 μm is a relatively large cell.
[0013] It is possible that the foam cells have such dimensions that the light passing through the component is at least partially diffusely scattered. In this way, in particular relatively large foam cells can assume the functions of the optical structures known from the prior art on the boundary surfaces of the component and / or of the scattering additives within the component. In contrast to the prior art, such a design with foam cells offers greater design freedom in terms of the optical design.
[0014] As an alternative, the foam unit may be dimensioned so that the light passing through the component is not diffusely scattered but can pass through the component relatively unimpeded. Thus, the foam unit does not or only insignificantly interferes with the light passing through the component, so that the optical component can achieve the intended light function.
[0015] It can be stipulated that the density of the foam unit is 10 4 Units / cm 3 Up to 10 8 Units / cm 3 By selecting the density of the foam cells, the optical properties of the component can be influenced.
[0016] Possibility exists is that component is configured as optically transparent optical lens or optically diffuse transparent optical lens or light guide.Here, component can be arranged for use in the lighting device of motor vehicle, for example, is used in headlight or taillight or in the lamp of the interior space of motor vehicle.
[0017] According to claim 10 , the optical component is produced by foam injection molding.
[0018] It is possible that the foam injection molding process is carried out by physical foaming with a blowing agent, in particular with a blowing gas such as nitrogen or carbon dioxide. As an alternative, there is the possibility of carrying out the foam injection molding process by chemical foaming with a carrier gas masterbatch. The properties of the foam structure and thus the optical effect can be influenced on the one hand by the wall thickness finally achieved and on the other hand by the blowing agent content and the process control of the foam injection molding process.
[0019] It can be provided that injection molding is performed after or during foam injection molding, in particular wherein the molding direction of the injection molding is implemented as a compression stroke and / or an expansion stroke. By combining with the method of injection molding, another possibility of influencing the foam structure and thus the component properties is provided.
[0020] There is the possibility of varying, in particular cyclically varying, the temperature of the mold used for the foam injection molding during the foam injection molding process. This results in another possibility of influencing the flowability of the material injected into the mold.
[0021] It can be provided that a gas counterpressure is used during the foam injection molding, thereby being able to influence the structure of the component.
[0022] The structure of the component can also be influenced by an insulating layer introduced into the mold. The insulating layer can be, for example, a coating on the mold surface or a film placed in the cavity of the mold.
[0023] It is also possible that the foam injection molding method is combined with another injection molding method within the scope of the multi-component injection molding method. For example, the optical lens produced by the foam injection molding method can be at least partially encapsulated by a black component in another cycle, for example. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention is explained in detail below with reference to the accompanying drawings.
[0025] Figure 1 A cross-sectional view showing a first embodiment of an optical component according to the present invention;
[0026] Figure 2 A cross-sectional view showing a second embodiment of an optical component according to the present invention;
[0027] Figure 3 A sectional view showing a third embodiment of the optical component according to the present invention;
[0028] Figure 4 A cross-sectional view showing a fourth embodiment of an optical component according to the present invention;
[0029] Figure 5 A perspective view showing a fifth embodiment of an optical component according to the present invention;
[0030] Figure 6 A perspective view showing a sixth embodiment of an optical component according to the present invention;
[0031] Figure 7 A perspective view showing an optical component according to the prior art;
[0032] Figure 8 A cross-sectional view showing an optical component according to the prior art;
[0033] Fig. 9 A cross-sectional view of an optical component according to the prior art is shown. DETAILED DESCRIPTION
[0034] In the figures, identical or functionally identical parts are provided with the same reference numerals. For better orientation, a rectangular coordinate system is drawn in some of the figures.
[0035] Figures 1 to 6The embodiment of the optical component 10 according to the present invention shown is manufactured by foam injection molding. The component 10 has a length L in a first direction X. In addition, the component 10 has a width B in a second direction Y perpendicular to the first direction X. In addition, the component 10 has a thickness D in a third direction Z perpendicular to the first direction X and the second direction Y (see FIG. Figure 6 ). Here, the length L and the width B are each significantly greater than the thickness D. For example, the length L and / or the width B of the optical component 10 may be between 1 cm and 100 cm, and the thickness D of the component 10 may be between 0.4 mm and 4.0 mm.
[0036] Figures 1 to 3 The component 10 shown comprises two outer edge layers 11 opposite one another, which extend in a plane formed by a first direction X and a second direction Y. The edge layers 11 limit the component 10 in a third direction Z, wherein the edge layers 11 do not have a foam structure. In the third direction Z, a core layer 12 is arranged between the edge layers 11, which core layer comprises a foam structure with a plurality of foam cells 13.
[0037] The size of the foam cell 13 can be between 10 μm and 100 μm. Here, the foam cell 13 is relatively small when the size is 10 μm, and is relatively large when the size is 100 μm. The density of the foam cell 13 can be between 10 μm and 100 μm. 4 Units / cm 3 Up to 10 8 Units / cm 3 between.
[0038] exist Figure 1 In the first embodiment shown, the component 10 has a relatively large thickness D and relatively coarse-celled foam cells 13. The light 14 passing through the component 10 is subjected to relatively strong scattering by the relatively large foam cells 13. In particular, the foam cells 13 are dimensioned in this case such that the light 14 passing through the component 10 is at least partially diffusely scattered. Thus, the foam cells 13 can assume the function of the optical structures on the boundary surfaces of the component and / or of the scattering additives within the component, which are known from the prior art.
[0039] exist Figure 2In the second embodiment shown, the component 10 has a relatively small foam unit 13 and a thickness D, which corresponds to the thickness D of the first embodiment. Due to the relatively small foam unit 13, the light 14 passing through the component 10 is subject to relatively little scattering. In particular, the foam unit 13 has such a size that the light 14 passing through the component 10 is not diffusely scattered, but can pass through the component 10 relatively unhindered. In this case, the foam unit 13 does not interfere with the light 14 passing through the component 10, or only interferes insignificantly, so that the optical component 10 can realize the provided optical function, wherein in particular Figure 2 A uniform light distribution can be achieved on the upper exit side.
[0040] exist Figure 3 In the third embodiment shown, the component 10 has a foam unit 13, which corresponds to the foam unit of the second embodiment in terms of size. In addition, the thickness D of the third embodiment is smaller than the thickness D of the first and second embodiments. Since the edge layer 11 in the second and third embodiments is the same size, the smaller thickness D of the optical component 10 of the third embodiment results in a smaller thickness of the core layer 12 with a foam structure. Since the optical path in the core layer 12 is shorter for this reason, the influence of the foam unit 13 on the light 14 passing through the component 10 is further reduced.
[0041] exist Figure 4 In the fourth embodiment shown, the thickness D of the component 10 is even smaller than the thickness D of the third embodiment. In this case, the thickness D is so small that the two edge layers 11 are adjacent to each other in the third direction Z and do not contain a core layer 12 with a foam structure in between. As a result, the light 14 passing through the component 10 can no longer be scattered at the foam unit 13, so that the component 10 has the optical properties of a transparent plate.
[0042] The wall thickness or thickness D of the component 10 and, if necessary, the size of the foam unit 13 can be influenced within the scope of the foam injection molding method by suitable method parameters. In particular, a reduction or at least partial suppression of the foam structure can be achieved by the foaming agent content and the injection molding performed after or during the foam injection molding, in particular, the molding direction of the injection molding can be implemented as a compression stroke and / or an expansion stroke. Another possibility for influencing the thickness of the edge layer 11, the surface properties of the component 10 and the size of the foam unit 13 is to cyclically change the temperature of the mold used for foam injection molding. In addition, the structure of the component 10 can be influenced by the gas back pressure during the foam injection molding and / or by suitable additives in the plastic used for foam injection molding.
[0043] Furthermore, the structure of the component 10 can be influenced by means of a barrier layer introduced into the mold. The barrier layer can be, for example, a coating on the mold surface or a film placed in a cavity of the mold.
[0044] There is also the possibility of combining the foam injection molding method within the scope of the multi-component injection molding method with another injection molding method. For example, a component 10 manufactured by the foam injection molding method and designed as a light lens can be at least partially encapsulated by a black component in another cycle, for example.
[0045] exist Figures 1 to 4 In the figure, the injection points 15 for injecting the material into the injection mold are indicated by arrows. Figures 1 to 4 In the embodiment of FIG. 1 , there is only one injection point, which is arranged on the left end side of the component 10 .
[0046] Figure 5 A fifth embodiment of an optical component 10 is shown, in which the foam injection molding is performed via two injection points 15 , so that the component 10 has a joining seam 16 . The injection points 15 are arranged on the underside of the component 10 here.
[0047] Figure 6 A sixth embodiment of an optical component 10 is shown, in which the foam injection molding takes place via only one injection point 15 arranged on the underside of the component 10 , so that the component 10 has no joining seam 16 .
[0048] Reference numerals list
[0049] 1Optical components
[0050] 2 Joint seam
[0051] 3 Injection Points
[0052] 4 Optical structure
[0053] 5Light passing through components
[0054] 6 Additives inside components
[0055] 10Optical components
[0056] 11. Edge layer of components
[0057] 12 core components
[0058] 13 Foam units
[0059] 14Light passing through the component
[0060] 15 injection points
[0061] 16 Joint seams
[0062] X first direction
[0063] Y second direction
[0064] Z Third direction
[0065] The length of the L member
[0066] Width of B member
[0067] D Thickness of component
Claims
1. An at least partially transparent optical component (10) for use in a motor vehicle, wherein: The component (10) has a length (L) in a first direction (X), a width (B) in a second direction (Y) perpendicular to the first direction (X), and a thickness (D) in a third direction (Z) perpendicular to the first direction (X) and the second direction (Y), wherein the length (L) and the width (B) are respectively significantly greater than the thickness (D), wherein the thickness (D) of the component (10) is between 0.4 mm and 4.0 mm, and the component (10) is a component (10) manufactured by a foam injection molding method.
2. The optical component (10) according to claim 1, characterized in that The length (L) of the optical component (10) is between 1 cm and 100 cm, and / or the width (B) of the optical component (10) is between 1 cm and 100 cm.
3. The optical component (10) according to any one of claims 1 or 2, characterized in that: The component (10) has two outer edge layers (11) facing each other, which extend in a plane formed by a first direction (X) and a second direction (Y) and limit the component (10) in a third direction (Z), wherein the edge layers (11) do not have a foam structure.
4. The optical component (10) according to claim 3, characterized in that The two edge layers (11) are placed against each other in a third direction (Z), or a core layer (12) is arranged between the two edge layers (10) in the third direction (Z), the core layer comprising a foam structure having a plurality of foam cells (13).
5. The optical component (10) according to claim 4, characterized in that The foam cells (13) have a size between 10 μm and 100 μm.
6. The optical component (10) according to any one of claims 4 or 5, characterized in that: The foam unit (13) has a size such that light (14) passing through the component (10) is at least partially diffusely scattered, or the foam unit (13) has a size such that light (14) passing through the component (10) is not diffusely scattered but can pass through the component (10) relatively unimpeded.
7. The optical component (10) according to any one of claims 4 to 6, characterized in that The density of the foam unit (13) is about 10 4 Units / cm 3 Up to 10 8 Units / cm 3 between.
8. The optical component (10) according to any one of claims 1 to 7, characterized in that: The component (10) is designed as an optically transparent optical lens, an optically diffusely transparent optical lens or a light guide.
9. The optical component (10) according to any one of claims 1 to 8, characterized in that: The component (10) is provided for use in a lighting device of a motor vehicle, for example in a headlight, a taillight or a light for the interior of a motor vehicle.
10. Method for producing an optical component (10) according to any one of claims 1 to 9, characterized in that The optical component (10) is manufactured by a foam injection molding method.
11. The method according to claim 10, characterized in that Foam injection molding is accomplished by physical foaming with a blowing agent, in particular a blowing gas such as nitrogen or carbon dioxide.
12. The method according to claim 10, characterized in that Foam injection molding is achieved by chemical foaming using a carrier gas masterbatch.
13. The method according to any one of claims 10 to 12, characterized in that After or during the foam injection molding, injection molding is performed, in particular wherein the molding direction of the injection molding is implemented as a compression stroke and / or an expansion stroke.
14. The method according to any one of claims 10 to 13, characterized in that During the foam injection molding process, the temperature of the mold used for the foam injection molding is varied, in particular cyclically varied.
15. The method according to any one of claims 10 to 14, characterized in that Gas back pressure is used during foam injection molding.