Airbag module with luminous surface

Abstract

An airbag module comprising a housing (10) and a cover (20) is described. The cover (20) comprises a top (25) having an outer surface, and the cover (20) has a first part (30) comprising a first section (31) of the top. At least one light-emitting element (66) is located outside the accommodation space of the airbag. Furthermore, a lighting device is provided having a light emitting surface (53a) forming part of the outer surface of the top (25) such that the light emitting surface (53a) emits light when the light emitting element (66) is in its active state. The cover (20) further comprises a second part (40) and a third part (50). The second part is located outside the accommodation space and comprises a top second section (42) covering the light emitting element (66), where the top second section (42) is at least partially spaced from the top first section (31). The third component (50) is distinct from the first component (30) and comprises a third section (53) of the top (25) filling a gap between the first section (31) of the top and the second section (42) of the top and comprising a light emitting surface (53a).

Description

[0001] manual

[0002] The invention relates to an airbag module according to the preamble of claim 1 and to a method for producing an airbag module according to claim 13 .

[0003] The invention relates firstly to a so-called driver airbag module, which is designed and intended to be mounted on a steering wheel body of a vehicle steering wheel. For this purpose, reference is mainly made to such a driver airbag module, but it should be mentioned that the invention is also applicable to other types of airbag modules, in particular to so-called passenger airbag modules.

[0004] The driver airbag module usually comprises a housing and a cover, such that the housing and the cover enclose a receiving space for the airbag cushion. In addition, an inflator is provided and is usually attached to the bottom wall of the housing. The cover of course comprises a top portion across the housing, wherein the top portion has a visible outer surface. A portion of the top portion forms a door, which can be opened by the deployed airbag cushion. The door is connected to a surrounding section of the top portion by at least one dividing line and at least one hinge.

[0005] In most cases the cover also comprises side walls which are usually attached to the housing by means of a snap connection.The cover is usually an injection moulded plastic part.

[0006] In order to enhance the optical appearance of the cover, ie the top thereof, it is known to provide lighting means with a light emitting surface which forms part of the outer surface of the top of the cover.

[0007] For example, from EP 1 973 767 A1 it is known to provide a light-emitting element (which may also be referred to as a "light-generating element") outside the accommodation space for the airbag cushion and to guide the light of the light-emitting element via a light guide to a central section of the top portion having the light-emitting surface. The problem here is that the light guide is usually in the deployment path of the airbag cushion.

[0008] US 6 848 706 also shows an airbag module, the top of which has a light-emitting surface. Here, the lighting device is completely outside the accommodation space of the airbag cushion, so that the lighting device does not hinder the deployment of the airbag cushion.

[0009] Starting from this prior art, the object of the present invention is to further improve the generic airbag module.

[0010] This object is achieved by an airbag module having the features of claim 1. Claim 13 defines a method for producing such an airbag module.

[0011] The process of forming a receiving space by means of a housing and a cover while placing the airbag cushion in the receiving space is usually relatively difficult and requires special machinery. It can prove difficult to ensure that the components of the lighting device are not damaged during this process. Therefore, according to the present invention, the airbag module is designed so that the airbag module comprises a first subassembly, the first subassembly comprising the airbag cushion packaged in the receiving space and the components enclosing the receiving space, wherein the subassembly can be manufactured before any components of the lighting device are mounted thereon.

[0012] To achieve this, the cover cannot be formed by a single component (as is common in the prior art), but by at least a first component, a second component and a third component. The first component can be connected to the housing so that the first component and the housing enclose a storage space for the airbag. The first component may include a first section of the top, the first section showing at least one door, which can be opened by the deployed airbag cushion. The second component may be located outside the storage space and include a second section of the top, which covers the light-emitting element. The second section of the top may be at least partially spaced apart from the first section of the top. In addition, the cover may include a third component different from the first component. The third component may include a third section of the top, which fills the gap between the first section of the top and the second section of the top, and may include a light-emitting surface.

[0013] Since the second part of the cover usually needs to have different properties from the properties of the first and second parts (in particular, it needs to be at least partially transparent or translucent), it is usually preferred that the first part of the cover, the second part of the cover and the third part of the cover are different parts. As an alternative, the third part can be molded onto the second part.

[0014] In an optically and mechanically preferred geometry, the third section of the top can be annular and surround the first section of the top, and the second section of the top can also be annular and surround the third section of the top. In this geometry, the third section of the top can also form a seal between the first section of the top and the second section of the top.

[0015] To simplify the assembly process, it may be preferred that the third part of the cover is snap-connected to at least one of the first part of the cover or the second part of the cover, preferably to both the first part of the cover and the second part of the cover.

[0016] As already mentioned, the third section of the top may comprise a light emitting surface. To this end, the third component may preferably be or may comprise a light diffuser. A preferred material for the light diffuser is silicone, in particular silicone with a Shore hardness between 30 Shore A and 90 Shore A. This further simplifies the assembly process and provides a tight seal.

[0017] Since the third component does not generate light, the lighting device usually comprises a light receiving surface for receiving light from the light emitting element. Although it is in principle possible to feed the light generated by the light emitting element directly into the third component of the cover, for geometric reasons and in order to optimize the light diffusion uniformity, it may usually be preferred that the lighting device also comprises a different light guiding element for guiding light from the light emitting element to the third component of the cover, wherein the light guiding element comprises the light receiving surface. The light guiding element may, for example, consist of silicone, polymethyl methacrylate (PMMA) or polycarbonate (PC).

[0018] As already mentioned, the housing, the first part of the cover and the airbag may be part of a first subassembly. The first subassembly may additionally include an inflator. The second part of the cover, the third part of the cover and the light-emitting element may be part of a second subassembly attached to the first subassembly. If a light-guiding element is used, this light-guiding element may also be part of the second subassembly.

[0019] In a preferred method for manufacturing an airbag module, assembly of the first subassembly can be completed before the second subassembly or a portion of the second subassembly is mounted on the first subassembly, so as to avoid damaging a portion of the second subassembly. Preferably, the entire second subassembly can be assembled before being mounted on the first subassembly.

[0020] The present invention will now be described in detail with the aid of preferred embodiments according to the accompanying drawings. The accompanying drawings show:

[0021] Figure 1 : all elements of the first subassembly of said embodiment of the airbag module;

[0022] Figure 2 : all elements of the second subassembly of said embodiment of the airbag module;

[0023] Figure 3 : a completely installed first subassembly and a completely installed second subassembly in a state where the second subassembly has not yet been installed on the first subassembly;

[0024] Figure 4 : Fully assembled airbag module ( Figure 3 The first subcomponent and Figure 3 a second subassembly mounted on the first subassembly);

[0025] Figure 5 : Figure 4 Detail D of , but airbag cushion not shown; and

[0026] Figure 6 : Perspective view of the airbag module.

[0027] The main concept of the present invention is that the airbag module comprises two subassemblies, one of which (the first subassembly) comprises all the elements necessary to form a "conventional" airbag module. Figure 1 It shows:

[0028] The housing 10 and the first part 30 of the cover define a housing for an airbag cushion 80 that can be deployed by a gas generator 70. As known in the art, the gas generator 70 is attached to the bottom wall 11 of the housing 10. The space enclosed by the housing 10 and the first part 30 of the cover is also preferably used as a housing space for the airbag cushion.

[0029] The majority of the housing 10 is formed like a conventional housing, which means that it comprises housing side walls 14 and the just mentioned bottom wall 11. A hole 12 for the inflator is arranged in the center of the bottom wall 11. In addition, a plurality of holes 13 for the hooks of the first part of the cover are arranged in the radially outer section of the bottom wall 11. In the embodiment shown, the gas generator 70 comprises a body 72 and a mounting flange 74 for attaching the gas generator 70 to the bottom wall 11.

[0030] The mounting section 15 extends radially outward from the upper end of the side wall 14. Instead of providing one annular mounting section 15, a plurality of mounting sections 15 can also be provided.

[0031] Like a common cover, the first part 30 of the cover comprises a side wall 34 and a top section, namely a top first section 31. The top first section 31 is substantially flush with the side wall 34.

[0032] Mounting hooks 36 extend from the lower edge of the side wall 34 as is generally known in the art.

[0033] Figure 2 All elements of the second subassembly of the airbag module are shown. In the embodiment described, the second subassembly has the following elements: a second part 40 of the cover and a third part 50 of the cover are provided. In this embodiment, the second part 40 of the cover exclusively forms the second section 42 of the top, and the third part 50 of the cover exclusively forms the third section 53 of the top. For this purpose, the terms "second part of the cover" and "second section of the top" are used interchangeably, and the terms "third part of the cover" and "third section of the top" are also used interchangeably.

[0034] The second part 40 of the cover is typically an injection molded part made of opaque standard airbag module cover material, such as thermoplastic olefin (TPO) and / or thermoplastic elastomer (TPE), but another material can be used since the second part 40 of the cover is outside the housing space that receives the airbag cushion 80.

[0035] The third part 50 of the cover (also called diffuser) is composed of a translucent diffusing material which preferably has a certain elasticity. According to the prior art, the preferred material for this third part 50 is silicone.

[0036] The second component 40 and the third component 50 are both annular, so that the second component 40 forms an outer ring and the third component 50 forms an inner ring. Connecting features are provided so that the third component 50 can be attached to the second component 40, wherein it is preferred that these attachment features work without any glue or the like. In this embodiment, the attachment features are protrusions 43 at the second component 40 and grooves 54 in the third component 50. In an alternative, the second component 40 can be overmolded onto the third component 50, or vice versa.

[0037] The third component 50 also has attachment features for attaching the third component 50 to the first component 30 of the cover.

[0038] When the airbag module is fully assembled, the upper surface of the third component 50 forms the light emitting surface 53a of the top of the cover of the airbag module. Since the third component 50 does not generate light, an illumination subassembly 60 is provided for providing light to the third component 50. In the embodiment shown, the illumination subassembly 60 includes three elements:

[0039] - For generating light, an electronic unit 65 is provided, which comprises an annular printed circuit board (PCB) 64 and a plurality of light emitting diodes (LEDs) 66 as light emitting elements (which may also be referred to as light generating elements). The LEDs 66 are mechanically and electrically connected to the PCB 64.

[0040] - In order to transmit the light generated by the LED 66 to the third part 50 of the cover (diffuser), a light guiding element 68 is provided, which has a tubular section with a light receiving surface 68a.

[0041] Finally, the mounting element 62 with the flange section 62a and the tube section 62b serves for mounting the electronic unit 65 and the light guiding element 68 on the mounting section 15 of the housing side wall.

[0042] Figure 3 Shown by Figure 1 The first subassembly is composed of the components shown and Figure 2It is noteworthy that the two subassemblies can be assembled completely independently of each other, so that the first subassembly (including the first part 30 of the cover, the housing 10, the airbag cushion 80 and the gas generator 70) is completely free of any light generating components, light guiding components or light emitting components. The first subassembly is assembled like a conventional airbag module, so that no further explanation is required.

[0043] Regarding the second subassembly: the third component 50 is mounted to the tube section 62b of the mounting element 62 and the upper end of the light guiding element 68, so that the third component 50 contacts or is in close proximity to the upper end of the light guiding element 68, so that light entering the light guiding element 68 at the light receiving surface 68a is guided to the third component 50 so that it can be emitted by the light emitting surface 53a. The LED 66 is close to the light receiving surface 68a of the light emitting element 68. As described above, the second component 40 of the cover is attached to the third component 50 of the cover at its upper end, and is attached to the flange section 62a of the mounting element 68 at its lower end.

[0044] The LED 66 is completely enclosed by the second part 40 of the cover and the flange section 62a so that light generated by the LED 66 can only leave the enclosure via the light emitting surface 53a of the third part 50 .

[0045] Figure 4 The fully assembled airbag module is shown after the second subassembly has been mounted to the first subassembly.During this final assembly step, the flange section 62a is attached to the mounting section 15 and the third part 50 of the cover is snapped to the first part 30 of the cover.

[0046] Figure 5 Shows Figure 4 Detail D of the top portion is shown, but the airbag cushion 80 is not shown. It can be seen that the light emitting surface 53a, the outer surface 25a of the top portion and the second section 42 of the top portion are flush and form a single continuous externally visible surface.

[0047] Figure 6 The airbag module is shown again, and in particular its top 25. The annular structure of the third part 50 and the second part 40 can be seen. In particular, it can be seen that the third part of the cover (third section 53 of the top) fills and seals the gap between the first section 31 of the top and the second section 42 of the top.

[0048] The light emitting elements (LEDs 66) are hidden beneath the top second section 42, but when they are in their active light emitting state, at least a portion of this light is emitted by the light emitting surface 53a.

[0049] Reference numerals list

[0050] 10 Housing

[0051] 11 bottom wall

[0052] 12 holes for inflator

[0053] 13 holes for cover hooks

[0054] 14 Shell side wall

[0055] 15 Mounting section of housing side wall

[0056] 20 Cover

[0057] 25 Top

[0058] 25a External surface of top

[0059] 30 First part of the cover

[0060] 31 First section at the top

[0061] 31a The outer surface of the first section of the top

[0062] 34 Side wall of the first part of the cover

[0063] 36 Mounting hook

[0064] 40 Second part of cover

[0065] 42 Second section from top

[0066] 42a The outer surface of the second section of the top

[0067] 43 Nose

[0068] 50 The third part of the cover (diffuser)

[0069] 53The third section from the top

[0070] 53a Outer surface / light emitting surface of the third section at the top

[0071] 54 Grooves

[0072] 60 Lighting subassembly

[0073] 62 Mounting components

[0074] 62a Flange section

[0075] 62b Pipe section

[0076] 63 Screws

[0077] 64PCB

[0078] 65 electronic units

[0079] 66LED (light emitting element)

[0080] 68 Light guiding element

[0081] 68a Light receiving surface

[0082] 70 Gas Generator

[0083] 72 Gas generator body

[0084] 74 Mounting flange

[0085] 80 airbag cushion

Claims

1. An airbag module, the airbag module comprising: Housing (10); A cover (20) comprising a top portion (25) having an outer surface, the cover (20) having a first component (30) comprising a first section (31) of the top portion; An airbag cushion (80) is located in the housing (10). and / or within a receiving space enclosed by the first component (30) of the cover; an inflator, the inflator being used to inflate the airbag cushion; at least one light emitting element (66), the at least one light emitting element being located outside the accommodation space, the light emitting element (66) having an active state, in which the light emitting element emits light; and a lighting device having a light emitting surface (53a) forming part of the outer surface of the top (25), such that when the light emitting element (66) is in its active state, the light emitting surface (53a) emits light to the outside of the module, Characterized in that the cover (20) further comprises: a second component (40), the second component being located outside the accommodation space and comprising a second section (42) of the top, the second section covering the light emitting element (66), the second section (42) of the top being at least partially spaced apart from the first section (31) of the top; a third component (50), the third component being different from the first component (30), The third component (50) includes a third section (53) of the top portion (25), The third section fills a gap between the first section (31) of the top and the second section (42) of the top, and includes the light emitting surface (53a).

2. The airbag module according to claim 1, characterized in that: The first part (30) of the cover (20), the second part (40) of the cover (20), and the third part (50) of the cover (20) are different parts.

3. The airbag module according to any one of claims 1 or 2, characterized in that: The third section (53) of the top is annular and surrounds the first section (31) of the top.

4. The airbag module according to claim 3, characterized in that: The second section (42) of the top is annular and surrounds the third section (53) of the top.

5. Airbag module according to any one of the preceding claims, characterized in that The third part (50) of the cover is snap-connected to at least one of the first part (30) of the cover or the second part (40) of the cover, preferably snap-connected to both the first part (30) of the cover and the second part (40) of the cover.

6. An airbag module according to claim 1 or any one of the preceding claims, characterized in that The third component (50) is a diffuser or includes a diffuser.

7. The airbag module according to claim 6, characterized in that: The diffuser is composed of silicone and preferably has a Shore hardness between 30 Shore A and 90 Shore A.

8. An airbag module according to any one of the preceding claims, characterized in that The lighting device further includes a light receiving surface (68a) for receiving light from the light emitting element (66).

9. The airbag module according to claim 8, characterized in that: The lighting device further comprises a light guiding element (68) for guiding light from the light emitting element (66) to the third component (50) of the cover, the light guiding element (68) comprising the light receiving surface (68a), and the light guiding element (66) is different from the third component (50) of the cover.

10. The airbag module according to claim 8, characterized in that: The light guiding element is composed of silicone, polymethyl methacrylate (PMMA) or polycarbonate (PC).

11. The airbag module according to any one of claims 1 to 10, characterized in that: The housing (10), the first part (30) of the cover (20) and the airbag cushion (80) are part of a first subassembly, which preferably also includes the inflator, and the second part of the cover, the third part (40) of the cover and the light-emitting element (66) are part of a second subassembly attached to the first subassembly.

12. Airbag module according to any one of claims 9 or 10 and according to claim 11, characterized in that The light directing element is also part of the second subassembly.

13. A method for manufacturing an airbag module according to claim 11 or claim 12, wherein assembly of the first subassembly is completed before the second subassembly or part of the second subassembly is mounted to the first subassembly.

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