EP1140570A1

EP1140570A1 - Closing system for airbag cover

Info

Publication number: EP1140570A1
Application number: EP99966969A
Authority: EP
Inventors: Ernst Johann Hauer
Original assignee: Imeco Einwegprodukte GmbH and Co KG
Current assignee: Imeco GmbH and Co KG
Priority date: 1998-12-16
Filing date: 1999-12-15
Publication date: 2001-10-10
Also published as: LU90330B1; WO2000035719A1

Abstract

The invention relates to an airbag cover (28) for the protection of an airbag, comprising a break line (30) along which the cover breaks so as to release an airbag (22) arranged inside the airbag cover in case of deployment of said airbag. According to the invention the break line has a first (32) and a second (34) row of closing members. The closing member of the first row are positioned along a first edge of an opening (36) in the airbag cover and the closing members of the second row are positioned along a second edge of the opening in the airbag cover in such a way that the closing members of the first row and those of the second row are offset in relation to each other in the direction of the break line. The closing members of the first row and the closing members of the second row interlock with a positive fit and in a zipper-like manner when the airbag cover is closed. The break line can be embodied, for example, as a zipper which is incorporated into the opening of the airbag cover.

Description

Closure system for airbag cover

The present invention relates to an airbag cover closure system for protecting an airbag.

As is known, systems for protecting the occupants are installed in motor vehicles, which are characterized in that a closed casing made of special textiles is filled with a gas by means of a gas generator. In the event of an accident, the envelope, which is referred to as the airbag, is filled with the gas very quickly, the vehicle occupants are absorbed by the airbag, the high accelerations (decelerations) are significantly reduced and the occupants are prevented from serious physical damage or this damage becomes significant decreased.

The airbags are mainly used as so-called frontal airbags, which catch the upper body and head of the occupants and have been widely used for this. The frontal airbag systems are supplemented by the so-called side airbags, which are activated in the event of an accident with a side collision.

The majority of the accidents take place as so-called offset accidents, which occur in the direction diagonally to the vehicle axis, between the side and the frontal area. With these accident sequences it is important that the body is caught in all focal points, upper body, pelvis and head center of gravity and the accelerations do not exceed certain maximum values. Consequently, airbags are installed in some vehicles today, which separate the frontal area, the lateral area and the head area of the passenger in the event of a side accident. As described, two airbags are required for side protection, the so-called side airbag that covers the center of gravity of the upper body and the head protection bag that intercepts the head area. The head protection bag is a very long part that can run from the front roof pillar, the so-called A pillar, through the B pillar to the C and D pillars of the vehicle.

BKTÄπGUNGSKOfta bag is conveniently housed in one of the columns, preferably at the airbag ends.

Further protection is required for the area of the lower extremities (legs), which are to be protected by a knee airbag and are intended to prevent the airbag and seat belt from being submerged.

By designing the front vehicle area as a so-called crunch zone and the resulting longer deformation zone, the front airbags can be filled more slowly than the side or head protection airbags arranged on the side. The front airbags have to open in a typical time of approx. 50-100 ms, while the side airbags have to open after a typical time of approx. 20-50 ms in order to protect the passenger in good time from the impact on the body parts .

All airbags must be protected against environmental influences and against access during operation, so that they can deploy in the event of an accident as quickly as possible and with the least possible energy consumption. In addition, the airbag must be enclosed as tightly and tightly as possible in order to take up as little installation space as possible. The folded airbag is protected by the airbag cover or airbag cover, also known as the airbag cover. The airbag cover normally surrounds the airbag very closely and thus protects it against any damage during processing and when installed. In the event of damage, the airbag cover tears open at a predetermined breaking line and releases the airbag so that it can develop freely. The predetermined breaking line is generally achieved by a carefully, technically precisely dimensioned weakening of the material used. This weakening of the material can take place, for example, through a perforation in which small incisions are made along the intended breaking line. In another embodiment, the predetermined breaking line is generated when the airbag cover is closed by means of a seam produced by sewing, the thread used for sewing and the stitch spacing being precisely tailored to the requirements. airbag deployment is coordinated. Alternatively, the airbag cover can also be closed by welding, for example by ultrasound welding, with precisely adapted welding patterns. In this case the weld line is the predetermined breaking line. The problem with such predetermined breaking points lies in the contradicting demands on the system. On the one hand, in the event of an impact, the predetermined breaking line has to be broken up easily and without effort in order to release the airbag within a very short time. On the other hand, the folded airbag must be securely closed to protect it from damage. Especially when manufacturing the airbags and installing them in the vehicle, the airbag cover must be able to cope with the deformations and loads that occur without being damaged, which could reduce its proper function over the required service life. In addition, the automobile manufacturers demand that any tampering with the airbag parts is visible so that in the event of improper deployment, unjustified claims for damage due to manipulated parts can be rejected.

The secure, tight and tight wrapping, the closure of the folded airbags, the quick opening and the low energy consumption are the main requirements placed on a system that protects the airbag until damage and its proper function, the deployment of the airbag enables.

All of the above-described methods for producing the predetermined breaking line have the disadvantage that, in order to ensure safe functioning, they deliberately weaken the wrapping material and at the same time reduce manipulation security and secure closure. The predetermined breaking point can easily damage the cover during manufacture or handling when installing it in the vehicle, which causes high failure rates and high costs. In the case of head protection airbags in particular, damage to the mostly used predetermined breaking seam or perforation can occur during manufacture and installation, since these parts can be over three meters long and must be attached to the roof rails. The object of the present invention is therefore to propose a system for safer storage of the airbag which avoids the disadvantages mentioned above.

This object is achieved by an airbag cover for protecting an airbag, with a predetermined breaking line at which the airbag cover tears open in the event of the deployment of an airbag arranged in the airbag cover in order to release the airbag. According to the predetermined breaking line comprises a first and a second row of closure members, the closure members of the first row being arranged on a first edge of an opening in the airbag cover and the closure members of the second row being arranged on a second edge of the opening in the airbag cover that the fastener of the first row and the fastener of the second row are offset from each other in the direction of the predetermined breaking line, and wherein the fastener of the first row and the fastener of the second row interlock positively in the closed state of the airbag cover, such as that is realized with a zipper. The predetermined breaking line can be designed, for example, as a slide-free zipper, i.e. as a zipper, in which the closure element for producing the positive connection, the so-called slide or glider, is removed, the zipper being incorporated into the opening of the airbag cover.

It should be noted that the airbag cover is made, for example, from a suitable textile material, into which the zipper is incorporated with its side textile straps. The zipper element can be incorporated as a closure in the opening of the airbag cover, for example by sewing, ultrasonic welding or other fastening techniques. Alternatively, the zipper with its edge strips can also be so wide that it can be used directly as a closure element for the cover. In this case, the two rows of teeth of the zipper are arranged directly on both sides of a wide textile band, which forms a tube in which the airbag is arranged when it is closed. Another possible embodiment of the airbag cover comprises an extrusion or injection molding profile which is closed on three sides, the open side of which is covered with a textile cover is closed, in which the zipper is incorporated. In this case, too, the side textile strips of the zipper can be made so wide that they can function directly as a textile cover on the open side of the profile. A zipper offers considerable strength transversely to the opening direction due to the interlocking connection of the closure members, so that the airbag can be tightly enclosed by the airbag cover without hindering opening along the predetermined breaking line. Such an airbag cover therefore meets the high requirements for handling during the installation of the airbag / airbag cover system in the vehicle, so that damage to the built-in part can be largely ruled out. In addition, the system according to the invention ensures great security against manipulation.

In its longitudinal opening direction, however, a zipper can easily be opened by the so-called slider or slider in its normal use and remains open only at a low load to the point that was opened by the slider. If the glider is removed after the closure, the zipper opens when it is open at one point, with the slightest effort by opening the form-fitting closure members, which open unhindered over the entire length as soon as the two ends are pulled apart.

The described opening mechanism makes it easy to separate the interlocking of the closure members and ensures that the sheath is opened securely along the predetermined breaking line. Since only the positive locking of the closure members has to be released, very little energy is consumed here, so that the airbag is not hindered by the cover when it is deployed.

In a preferred embodiment, at least one of the rows of closure members has a gap such that the chain formed by the interlocking interlocking closure elements when the airbag cover is closed is broken through at one point and has an opening. The opening point of the closure members can also be formed thereby will be such that the first row fastener and the second row fastener do not interlock at one point. For example, these can be the starting elements of the respective rows that are not connected to one another. It should be noted that chain is used in this context as an "uninterrupted series of like".

After the closure and removal of the slide, the opening is then preferably provided with a suitable cover, which is preferably provided with at least one predetermined breaking point or which is designed as a predetermined breaking point. For this purpose, the opening can be closed, for example, with a particularly suitable adhesive strip with predetermined breaking points.

Through the opening in the positively connected closure elements, it is achieved that the zipper opens with little effort due to the loading of the opening airbag after the predetermined breaking point has broken. This proposal exploits a normally undesirable property of the zipper, that it fails in the absence of a single or fewer of the form-fitting closure elements and opens in the process without any effort.

In an advantageous embodiment, the opening in the interlocking closure elements is arranged in a region of the closure members in which an airbag arranged in the airbag cover is first filled with inflowing gas when it is triggered and is inflated by the pressure that builds up. This type of closure therefore appears to be particularly suitable for airbags which first deploy at a precisely determined point. This appears to be particularly suitable, for example, in the case of protective head airbags or side airbags which are predominantly filled from one end and then assume an elongated shape. In these airbags, which are elongated in shape, the inflowing gas initially builds up pressure in the blowing area, by means of which the cover, which is specifically arranged in this area, prematurely destroys at its predetermined breaking point and the airbag cover, which surrounds the folded airbag, opens the positive locking elements and the cover opens without effort along the determined line. A method for producing a predetermined breaking line in an airbag cover according to the present invention accordingly comprises the following steps: a) incorporating a zipper into an opening in the airbag cover, b) closing the zipper, c) removing the slide of the zipper.

After the slide of the zipper has been removed, the chain formed by the interlocking fastener elements of the zipper is preferably broken at at least one point or the links are not connected to one another at one end, so that these fastener elements can be opened again easily.

Subsequently, the opening created in the closure members by breaking the chain or by opening the closure members is provided with a cover, the cover preferably having a predetermined breaking point or being designed as a predetermined breaking point. An embodiment of the invention will now be described below with reference to the accompanying figures. Show it:

1 shows the arrangement of a number of different types of airbag in a vehicle, in which the airbag cover according to the invention can advantageously be used; 2 shows a detail from an embodiment of an airbag cover according to the invention in the closed state;

3 the airbag cover of FIG. 2 at the moment the airbag is triggered; 4 shows a first embodiment of an airbag cover; 5 shows an alternative embodiment of an airbag cover. 1 shows the arrangement of various types of airbag in a vehicle 10. The airbag cover according to the invention can be used advantageously in all of these types.

The most common type of airbag is the frontal airbag 12. This is on the driver's side of the vehicle in the steering wheel 14 and on the passenger side in the Dashboard integrated. In the lower area of the dashboard 16, knee airbags 18 ensure that knee injuries are largely avoided.

In order to protect the vehicle occupants in the event of a side impact, so-called side airbags 22 are integrated laterally in the seats 20 and inflate between the occupant and the respective vehicle door in the event of a side impact. In addition, so-called head airbags 24 are inflated in the head area of the occupants, which can extend along the roof edge of the vehicle from the A pillar to the D pillar. The gas generators for such head airbags are preferably arranged in one of the vehicle pillars. FIGS. 2 and 3 show an embodiment of an airbag cover 28 according to the invention, FIG. 2 showing the airbag cover in the closed state and FIG. 3 the airbag cover when the airbag is triggered.

The airbag cover 28 has a predetermined breaking line 30, at which the airbag cover 28 tears open and releases it when the airbag is triggered. According to the invention, the predetermined breaking line 30 comprises a first row 32 of closure elements and a second row 34 of closure elements which are arranged on both sides along an opening 36 in the airbag cover 28 in such a way that they can interlock positively in the manner of a zipper to close the airbag cover. In the embodiment shown, the predetermined breaking line 30 is designed as a zipper, in which the slide was removed after the closure. The zipper is incorporated, for example, with its lateral textile edge strips 38 into the material of the airbag cover, which can be done, for example, by sewing in or ultrasonic welding. In order to ensure easy opening of the zipper when the airbag is triggered, the chain of the interlocking interlocking fastener elements of the zipper is preferably broken through at one point, so that an opening 39 is created in the chain. This opening 39 can be produced, for example, in that one of the rows of closures has a gap at one point. This is preferably the case in a range in which the In the event of deployment, the airbag is first filled with gas, ie in the area in which the airbag inflates first.

In the embodiment shown, the opening 39 in the interlocking interlocking members is made such that the end members 40 of the rows of interlocking members do not engage. In contrast to a normal zipper, in which the end members are hooked into one another to prevent the zipper from opening behind the slider, the two end members 40 of the present fastening system are accordingly not connected to one another. This enables the predetermined breaking line to be opened easily when the two rows of fasteners are pulled apart laterally. Such a relative movement of the two rows of fasteners occurs precisely at the point in time when the airbag is deployed when, as shown, it is filled with gas at one end by a gas generator and inflates. After the zipper has been closed and the slider has been removed, the opening 39 is preferably provided with a suitable cover 42, which is preferably provided with at least one predetermined breaking point 44 or which is designed as a predetermined breaking point. For this purpose, the opening can be closed, for example, with a particularly suitable adhesive strip with predetermined breaking points. In this way, the predetermined breaking line is normally protected against unintentional tearing open. In the event of deployment, however, the cover 42 tears open at its predetermined breaking point 44 and thus enables the airbag cover to be opened unhindered.

It should be noted that the airbag cover, which is shown in FIGS. 2 and 3, is produced, for example, from a suitable textile material, into which the zipper with its side textile bands 38 is incorporated. Such a configuration is also shown in a cross section in FIG. 4. Alternatively, the zipper with its edge strips can also be made so wide that it can be used directly as an airbag cover. In this case the two rows of teeth of the zipper are directly on both sides arranged a wide textile band, which forms a tube when closing, in which the airbag 45 is arranged.

Another possible configuration of the airbag cover is shown in FIG. 5. This configuration comprises an extrusion or injection molding profile closed on three sides, the open side of which is closed with a textile cover 48 into which the zipper is incorporated. In this case, too, the lateral textile strips 38 of the zipper can be made so wide that they can function directly as a textile cover on the open side of the profile.

Claims

claims

1. Airbag cover for protecting an airbag, with a predetermined breaking line, at which the airbag cover tears open in the event of the triggering of an airbag arranged in the airbag cover to release the airbag, characterized in that the predetermined breaking line comprises a first and a second row of closure members, the Closure members of the first row are arranged at a first edge of an opening in the airbag cover and the closure members of the second row are arranged at a second edge of the opening in the airbag cover such that the closure members of the first row and the closure members of the second row in the direction of the predetermined breaking line are offset with respect to one another, and the closure members of the first row and the closure members of the second row engage in a form-fitting manner in the closed state of the airbag cover.

2. Airbag cover according to claim 1, characterized in that the predetermined breaking line is designed as a slide-free zipper, which is incorporated into the opening of the airbag cover.

3. Airbag cover according to one of claims 1 or 2, characterized in that at least one of the rows of closure members has a gap, so that the chain formed in the closed state of the airbag cover by the interlocking closure members is broken at one point and has an opening.

4. Airbag cover according to one of claims 1 or 2, characterized in that the closure members of the first row and the closure members of the second row do not engage in one another at one point, so that the chain formed at this point by the interlocking closure members when the airbag cover is closed is broken and one

Has opening.

5. Airbag cover according to claim 4, characterized in that the opening in the chain formed by the interlocking interlocking links is arranged in a region of the chain in which one in the Airbag envelope arranged airbag is inflated when triggered first.

6. Airbag cover according to one of claims 3 to 5, characterized in that the opening of the chain formed by the interlocking closure members is provided with a cover.

7. Airbag cover according to claim 6, characterized in that the cover is provided with a predetermined breaking point or is designed as such.

8. Airbag system with at least one airbag and at least one airbag cover according to one of claims 1 to 6.

9. A method for producing a predetermined breaking line in an airbag cover, characterized by the steps a) incorporating a zipper into an opening in the airbag cover, b) closing the zipper, c) removing the slide of the zipper.

10. The method according to claim 9, characterized in that after removing the slide of the zipper, the chain formed by the interlocking closure members of the zipper is broken at at least one point.

11. The method according to claim 10, characterized in that an opening generated by the breaking of the chain in the chain is then provided with a cover which is designed as a predetermined breaking point.