Airbag protection device for a vehicle occupant restraint system and method of manufacturing an airbag protection device

The invention relates to an airbag protection device (10) for a vehicle occupant restraint system that includes an airbag mounting device (12). The airbag mounting device (12) includes first and second mounting members (14) which are mounted to the vehicle (100) spaced apart from each other and a cross-member (16) made of bent wire. An airbag (22) is mounted to the cross-member (16) in the folded state.

FIELD OF THE INVENTION

The invention relates to an airbag protection device for a vehicle occupant restraint system comprising an airbag mounting device and an airbag as well as to a method of manufacturing an airbag protection device.

BACKGROUND OF THE INVENTION

Airbag protection devices serve for mounting and for protecting an airbag of a vehicle occupant restraint system in a vehicle. As the designs of various types of vehicles differ from one another, the design of the airbag protection device has to be adapted to the respective type of vehicle.

It is the object of the invention to provide an airbag protection device capable of being manufactured in an inexpensive manner and of being adapted to different types of vehicles in a simple fashion as well as an inexpensive manufacturing method of an airbag protection device for a plurality of various vehicle types.

SUMMARY OF THE INVENTION

The object of the invention is achieved by an airbag protection device for a vehicle occupant restraint system according to claim1. The airbag protection device according to the invention comprises an airbag mounting device having first and second mounting members which are mounted to the vehicle spaced apart from each other, a cross-member made of bent wire and an airbag which in the folded state is mounted to the cross-member. The modular structure of the airbag mounting device enables the individual component parts to be manufactured in a simple and inexpensive manner and to be easily adapted to various vehicle types independently of each other. For instance, the mounting members can be designed as standard components irrespective of the vehicle type and differently bent cross-members can be provided for various types of vehicles.

In order to permit, on the one hand, tight mounting of the airbag to the airbag mounting device and, on the other hand, perfect deployment of the airbag, the airbag can be mounted to the cross-member by means of holding elements which can be destroyed upon activation of the vehicle occupant restraint system so that the airbag can deploy.

The airbag is preferably mounted directly to the cross-member, preferably by airbag ears through which the bent wire of the cross-member is run. In this way simple fastening of the airbag to the cross-member is permitted.

In order to permit movement of the airbag protection device upon activation of the vehicle occupant restraint system the cross-member can be movably supported, especially in a pivoting fashion, to the mounting members.

In order to move the airbag upon deployment to an advantageous position relative to the vehicle, the cross-member can be provided in a home position in the non-activated state and can be moved to an end position, especially by pivoting, upon deployment of the airbag.

In order to protect the folded airbag in a better way a flexible protective element can be provided for at least partly surrounding the folded airbag.

Preferably a flexible protective element is provided which is designed to cover an area of the vehicle adjacent to the airbag upon deployment of the airbag. In this manner, edges or surfaces of other components in the vehicle can be covered so as to protect the airbag during deployment and/or to permit more rapid deployment.

For instance, the protective element has a low friction coefficient, which facilitates sliding of the unfolding airbag on the protective element.

The cross-member is advantageously bent in the area between the mounting members spaced apart from each other so as to surround a component part of the vehicle disposed between the two mounting members. Thus especially component parts of the vehicle at which no direct mounting of the mounting members is possible can be surrounded by the cross-member.

The cross-member is bent in U-shape, for example, in the area of the mounting members, wherein the mounting member is preferably connected to both legs of the U-bent cross-member. In this way, the mounting of the cross-member to the mounting members is improved.

The object of the invention is moreover achieved by a method of manufacturing an airbag protection device for a plurality of vehicle types, the method comprising the following steps. First and second mounting members are provided, the mounting members being designed independently of the type of vehicle. A wire is bent to form a cross-member dependent on the respective type of vehicle. The cross-member is fastened to the mounting members and an airbag is fastened to the cross-member. Since the mounting members are standard components and only the cross-member formed of the bent wire has to be designed in response to the respective type of vehicle, it is possible in a simple and inexpensive manner to adapt the airbag protection device to different vehicle types. Since no particular tools are required to bend the wire for forming the cross-member for different configurations for different vehicle types, the manufacture of various embodiments of the cross-member is especially inexpensive. In particular compared to cross-members which are made as blanked or blanked and bent part, the wire configuration has considerable advantages in terms of costs. The costs of tools in the case of blanked and blanked and bent parts are definitely higher than the costs of tools for manufacturing a cross-member in the form of a bent wire.

The wire is preferably bent by a programmable bending machine which is differently programmed for different types of vehicles. This permits inexpensive manufacture, especially in series production, of differently shaped cross-members for various vehicle types by one machine only without any tools having to be exchanged.

DESCRIPTION OF THE EXAMPLE EMBODIMENTS

By way ofFIGS. 1,2and3a first embodiment of an airbag protection device10of a vehicle occupant restraint system is illustrated. In the shown embodiment the vehicle occupant restraint system is a head airbag, but the airbag protection device can also be provided for other vehicle occupant restraint systems including an airbag.

FIG. 1shows an airbag mounting device12of the airbag protection device10including first and second mounting members14which are mounted to a vehicle100spaced apart from each other. A cross-member16made of bent wire is fastened to the respective first and second mounting members14.

The cross-member16has two end portions18in which the cross-member16has several U-shaped bends, the cross-member16being connected to the mounting members14at said end portions18. It is also possible, as a matter of course, that the cross-member16is connected to at least one mounting member14in a central portion of the cross-member16.

The vehicle100includes a component part110in the area between the first and second mounting members14. In the illustrated embodiment, the component part110is a passage of a venting system of the vehicle100at which no direct mounting of the airbag protection device10is possible. The component part110is surrounded by a lining120in the area below the airbag protection device10.

The cross-member16is furthermore bent in a central portion20between the mounting members14spaced apart from each other so as to surround the component part110of the vehicle100.

In the shown embodiment the wire of the cross-member16has a circular cross-section. However, also different cross-sections could be provided.

FIG. 2shows the airbag protection device10including an airbag22. The airbag22has plural ears by which the airbag22is fastened directly to the cross-member16. The bent wire of the cross-member16is run through the ears at the airbag22. The ears of the airbag22for fastening to the cross-member16are not visible inFIG. 2.

In the folded state the airbag22is moreover fastened to the cross-member16by holding elements24. The holding elements24are destroyed upon activation of the vehicle occupant restraint system so that the airbag22can be deployed. In the shown embodiment the holding elements24are adhesive tapes that break upon activation of the vehicle occupant restraint system.

It is also possible that the airbag22is fastened to the cross-member16exclusively by means of the destroyable holding elements24prior to activation of the vehicle occupant restraint system.

As it is clearly visible fromFIG. 1, the cross-member16is connected to the mounting member14by a U-bent section of the end portion18of the wire. The lower leg of the U-shaped wire is rotatably supported in a bearing19in the mounting member14, whereby the cross-member16is allowed to pivot about the axis of rotation of the lower leg of the U-shaped section. The upper leg of the U-shaped section is connected to the mounting member14by a holding element24in the form of an adhesive tape and fixes the cross-member16in a home state of the airbag protection device10.

Upon activation of the vehicle occupant restraint system the holding element24is destroyed and the cross-member16carries out a swivel movement from its home position shown inFIGS. 1 and 2to an end position shown inFIG. 3upon deployment of the airbag. The swivel movement is marked by the arrows26inFIG. 3. The airbag protection device10is arranged at the vehicle such that the central portion20of the cross-member16is provided at the end position of the cross-member in the area of the edge of the lining120of the component part110of the vehicle100.

The swivel movement of the cross-member16enables the airbag protection device10to require, with the cross-member in its home position, as little construction space as possible in the vehicle when the airbag22is folded, whereas upon activation of the vehicle occupant restraint system and deployment of the airbag22the cross-member16is disposed at an end position advantageous to the deployment of the airbag22.

TheFIGS. 4 and 5illustrate a second embodiment of an airbag protection device10. For the sake of clarity, in each case the airbag protection device10is shown without an airbag22. Compared to the first embodiment, the second embodiment additionally includes a flexible protective element28which is a sliding fabric in the shown embodiment. The protective element28is made of a material having a low friction coefficient or is provided with a coating having a low friction coefficient.

As is evident inFIG. 4, the flexible protective element28surrounds the airbag22. The protective element28is chosen in the shown embodiment so that the width of the protective element28corresponds to the width of the lining120of the component part110of the vehicle having a projection30on both sides of the lining120.

FIG. 5illustrates the airbag protection device10ofFIG. 4, the cross-member16being pivoted into its end position according to the arrows26. The flexible protective element28is unrolled by the deploying airbag22and covers the edge as well as parts of the surface of the lining120of the component part110of the vehicle100. This is to prevent the airbag22, upon deployment, from being caught at the edge of the lining120, and the airbag22can slide more easily and rapidly over the lining120projecting into the interior of the vehicle.

Hereinafter a manufacturing method of the airbag protection device10shall be illustrated. The manufacturing method permits the manufacture of an airbag protection device10for a plurality of different types of vehicles in a simple manner.

In a first method step the mounting members14are provided. The mounting members14are designed independently of the vehicle type and can be mounted at appropriate positions of the different vehicle types.

In a second method step a wire is shaped by bending to form the cross-member16. The cross-member16is designed differently depending on the vehicle type, for instance in response to the fastening positions of the mounting members14or the specific design of the component part110and the lining120thereof.

Since only one tool is required to bend a wire independently of the respective final shape, inexpensive manufacture of the airbag protection device10is possible. The mounting members14can be used as standard parts for different types of vehicles.

In the preferred method variant the wire is bent by a programmable bending machine which is differently programmed for different types of vehicles. One single CNC bending machine of this type thus permits the series production of airbag protection devices10having differently shaped cross-members16for a plurality of different types of vehicles.

In further method steps the cross-member16is fastened to the mounting members14and the airbag22is fastened to the cross-member16. To this end, the lower legs of the U-shaped sections of the end portions18of the cross-member16are rotatably supported in a bearing19of the mounting members14and the upper legs of the U-shaped sections are fixed to the mounting members14by the holding elements24.