Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
  • B60R21/20—Arrangements for storing inflatable members in their non-use or deflated condition; Arrangement or mounting of air bag modules or components
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
  • B60R21/20—Arrangements for storing inflatable members in their non-use or deflated condition; Arrangement or mounting of air bag modules or components
  • B60R21/201—Packaging straps or envelopes for inflatable members

Definitions

• the invention relates to a front airbag device according to the preamble of Claim 1 , a front airbag module according to Claim 9 and a process for manufacturing a front airbag module according to Claim 11.
• a front airbag device which protects the passenger in case of a frontal crash or a frontal crash which is offset to the side.
• a front airbag device exhibits a front airbag module consisting of a housing, an airbag and a gas generator.
• the airbag module is connected to the instrument panel on the side facing away from the passenger.
• the housing exhibits an exit opening through which the airbag is folded into the housing during manufacture, and through which it exits from the housing if the gas generator is triggered.
• the instrument panel has a door at the location of the exit opening of the housing, so that the airbag expands through the instrument panel into the interior of the vehicle when the gas generator is triggered. This means that the area of the instrument panel on which the front airbag module is held is a part of the front airbag device.
• the exit opening is closed with a closing element which generally consists of a foil.
• a closing element which generally consists of a foil.
• a cover foil is mostly glued to or welded with the housing on the narrow sides of the exit opening, which is in most cases rectangular in shape.
• the cover foil exhibits set break lines in the form of perforations, whereby these perforations have to lie at precisely predefined locations.
• the task of the present invention is to improve a front airbag device and a front airbag module respectively of the generic type in such a way that manufacture is made easier and therefore costs can be saved.
• perforated cover foils are used in order to close the exit opening.
• the perforation is two-dimensional and forms for example a double T. This makes it necessary first to make up the cover foils, namely to cut and perforate them and then to connect them to the housing.
• a foil is used, that is isotropic in at least one first direc- tion. In other words: The foil looks the same regardless of the length one looks at it. This first direction is generally parallel to sides of the exit opening to which the cover element is fixed.
• the cover element has no set split line at all and is thus ho- mogenous.
• the foil forming the cover element can be directly wound off from a roll. The intermediate step of making up the foils is no longer needed, which makes production easier and correspondingly more cost effective.
• the cover foil now has no perforation or similar to form a set split line, other measures have to be taken which ensure that the airbag can exit from the housing through the exit opening when the gas generator is triggered.
• This is achieved in that the connection between the cover foil and the housing is in a first section such that the expanding airbag destroys the connection. This can easily be achieved, for example, if only a few weld points are present.
• means are provided in the second connection section which prevent the cover foil from detaching from the housing during expansion. This could be achieved, for example, in that the connection between cover foil and housing is formed to be considerably more robust in the second connection section than the connection in the first connection section. However, this is generally not to be preferred, as it would again somewhat increase manufacturing costs.
• the second connection section is held in clamped fashion between a cover element, which spans over the front airbag module, and the housing.
• the cover element is a part of the instrument panel.
• one split line in most cases a perforation, extends in one first direction across the entire length of the cover foil. Consequently, the foil forming the cover foil can also be rolled directly from a roll. As in the first embodiment, no making up of the cover foil is necessary. It is possible that the split line (perforation) is applied to the foil by the manufacturer of the foil so that the front section of the foil can by directly attached to the housing. This is the preferred possibility. Alternatively it would also be possible that the foil is supplied to the manufacturer without any split lines and that a continuous split line is applied to the foil after being rolled off but before being attached to the housing.
• Figure 1 A schematic representation of a front airbag module in cross-section
• Figure 2 The front airbag module from Figure 1 in a view from direction A, - A -
• FIG. 3 The front airbag module from Figure 1 , which is connected with the instrument panel of the vehicle so that the front airbag device results,
• Figure 4 The items shown in Figure 3 with deployed airbag, Figures 5-8 A schematic representation of the mounting of the cover foil on the housing of the airbag module from Figure 1 ,
• Figure 9 A second embodiment of an airbag module in a representation according to figure 2,
• Figure 10 The mounted airbag module of figure 9 in a representation according to figure 3 and
• FIG 11 The items shown in Figure 10 with deployed airbag.
• Figures 1 and 2 show a front airbag module for a front airbag device.
• Figure 1 is a sectional view and Figure 2 is a view from Direction A from Figure 1.
• the front airbag module exhibits a housing 10 with a floor 12 and a circumferential sidewall 14, a gas generator 20, an airbag 22 folded into the housing and a cover foil 30.
• Floor 12 and side walls 14 surround an accommodation area of housing 10, which exhibits exit the opening 18 on the side lying opposite to the floor 12.
• Floor 12 is of basically rectangular shape, so that the exit opening is also rectangular and is framed by the front surfaces 16 of the side walls 14.
• the circumferen- tial side wall 14 has two short first sides 14a and two long second sides 14b. From the short first sides 14a, fixing flanges 19 with fixing holes 19a extend and flush with front surfaces 16.
• Cover foil 30 is connected with front surface 16 of side wall 14 along two connec- tion sections 32a, 32b.
• the two connection sections 32 basically extend over the entire length of the front surface of short first sides 14a.
• connection sections 32 are welded connections between cover foil 30 consisting of plastic and housing 10 consisting of plastic.
• glued connections are also possi- ble.
• the cover foil 30 is homogenous and in particular does not exhibit any perforation or similar weakened locations along which cover foil 30 could tear open during expansion of the airbag 22.
• the connection sections 32 are equally made, so that they cannot withstand the force during expansion of airbag 32, so that cover foil 30 would completely detach from the housing during expansion of the airbag without further measures.
• complete detachment of the cover foil during expansion of the airbag is not desired, and therefore means are provided which have the function of preventing complete detachment.
• this function is taken over by a cover element, which spans over the exit opening of the housing.
• the cover element is a part of the instrument panel.
• Figure 3 shows a complete front airbag device, which consists of the front airbag module just described and a section of the instrument panel 40.
• the front airbag module is connected with the inner side of instrument panel 40 by means of screws 50.
• a door 42 is located above the exit opening of the housing; this door is delineated by a basically U-shaped set break line 44 and a hinge 46.
• the cover foil is held in clamped fashion between the front surface 16 of housing 10 and the instrument panel 40 serving as cover element here, while the cover foil 30 lies open in relation to instrument panel 40 in the area of second connection section 32a.
• the gas generator is triggered, the airbag 20 enters into the interior space of the vehicle. In this process the airbag detaches the cover foil
• FIGs 5 to 8 show how cover foil 30 is preferably applied to the housing 10.
• a piece of foil is wound off from the foil roll 70, so that a front section 70a of this foil comes to lie on the housing 10 (see Figures 5 and 6).
• this front section of the foil which is still wound on, is connected with the housing 10 along the connection sections, for example welded in such a way as is indicated in Figure 7 in schematic form.
• the front section is separated off ( Figure 8), so that the front section 70a forms the cover foil 30. It can be seen that it is not necessary to make up the foil in advance, and that the foil is utilised almost completely without wastage.
• the figures 9 to 11 show a second embodiment of the invention.
• the cover foil 30 is not completely homogenous but isotropic in one direction, namely the longitudinal direction L of the foil.
• isotropic in one direction the following fact is meant:
• the cover foil looks the same regardless the longitudinal po- sition.
• two longitudinal positions U and b are marked with the first edge 34a of the cover foil 30 as reference point.
• This property also as translation invariance.
• the cover foil 30 is attached - for example glued or welded - to the housing via connecting sections 32a ,32b.
• a perforation 35 serving as a split line extends from the first edge 34a of the cover foil 30 to the second edge 34b of the cover foil 30 lying opposite to the first edge 34a of the cover foil. This perforation extend parallel to the connecting sections 32a,32b and thus parallel to the third and fourth edge 34c,34d of the cover foil 30. Consequently this perforation can be a part of the supplied foil and does not need to be created during the manufacture of the airbag module.
• the process of manufacture is the same as described in the first embodiment (figures 5 to 8) with the exception that it is possible to create both connecting sections that strong that they can withstand the forces occurring during deployment of the airbag.
• Another difference to the manufacturing process described for the first embodiment is that the connecting sections extend parallel to the longitudinal direction of the foil but it needs to be emphasised that this would also be possible in the first embodiment.
• the connecting sections 32a, 32b extend parallel to the longitudinal direction of the foil and thus to the perforation 35 forming the split line.
• the figures 10 and 11 show the airbag module of the second embodiment in a representation according to figures 3 and 4 of the first embodiment.
• the figure 10 shows a sectional view along plane B-B of the airbag module of figure 9 with the airbag module being mounted to an instrument panel 40.
• figure 11 which shows the items of figure 10 during the deployment of the airbag, one can see that both connecting sections remain intact and that the cover foil is broken along the perforation.
• connection sections 32a,32b should remain intact during deployment of the airbag, it would also be possible to clamp the third and/or the fourth edge of the cover foil 30 between the front sur- face 16 of the housing 10 and the instrument panel 40.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Air Bags (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (6)

Family Cites Families (3)

• 2007
  • 2007-12-05 DE DE102007058546.4A patent/DE102007058546B4/de not_active Expired - Fee Related
• 2008
  • 2008-12-04 WO PCT/EP2008/010313 patent/WO2009071306A1/en active Application Filing
  • 2008-12-04 EP EP08857877A patent/EP2231443A1/de not_active Withdrawn

Patent Citations (6)

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