DE102007044824B4 - Safety device for a motor vehicle seat and motor vehicle seat - Google Patents

Abstract

Safety device for a vehicle seat (1) provided with a cushion (3) with an airbag (5) which is coupled to a gas generator (6) which is activated in the presence of sensor data on an accident or an imminent accident and the airbag (5 ) filled with gas and unfolded, and with an activator (8) through which the airbag (5) is additionally repeatedly reversibly filled with gas, wherein the airbag (5) is formed as a single-chamber airbag (5), characterized in that the Airbag at least one elastic component (9) which brings the airbag (5) after filling by the activator (8) back to its original position and a tether (9) forming the elastic component, and in or on the airbag (5 ) an inelastic tether (10) is arranged, wherein the inelastic tether (10) has a greater length than the maximum length of the elastic tether (9).

Description

The invention relates to a safety device for a padded motor vehicle seat with an airbag, which is coupled to a gas generator which is activated in the presence of sensor data on an accident or an imminent accident and filled and deployed the airbag with gas, and with an activator , via which the airbag is additionally repeatedly reversibly filled with gas, wherein the airbag is designed as a single-chamber airbag. The invention also relates to a motor vehicle seat with a safety device.

Motor vehicle seats are increasingly equipped with functions that increase the comfort and safety of seat occupants. Thus, it is possible to inflate in the seat cheeks of a motor vehicle seat, so both in the seat back and in the seat cushion, depending on the particular driving situation. Thus, it is possible during cornering to inflate that seat cheek associated with the outer radius of the turn to provide a better connection of the seat occupant to the seat. In addition, the air cushion can be designed to increase the seating comfort and to adapt the seat contour to the seat occupant.

From the DE 10 2005 059 997 A1 a safety device in a motor vehicle seat is known, in which an inflatable via a gas generator airbag is additionally coupled with an activator that can repeatedly fill the airbag reversibly with gas. Due to the arrangement of the airbag in the side wall can be done with an increase in volume of the airbag through the activator better connection to the seat. The seat back is enlarged and moved in the direction of the seat occupant. In the event of an accident, a gas generator is activated which causes the airbag to exit the motor vehicle seat so that the airbag can extend between the seat occupant and a body structure.

From the EP 1 140 572 B1 is a motor vehicle seat with a padded seat part is known in which an airbag is inflated in an accident, thereby tearing a fabric at a joint seam between two fabric blanks. Between these cover fabric blanks, a strip of fabric material is used, which allows an enlargement of the side cheek of the seat. Instead of a freely deployed airbag over the seat back or the seat cushion protruding side cheeks are inflated bulging, so that the projection of the side cheeks increases. Within the side cheeks relatively stable airbags are generated over which a vehicle occupant is padded against intruding objects and stabilized in a desired seating position.

The DE 10 2006 005 137 A1 relates to a vehicle seat for motor vehicles having an airbag. This airbag can be used in addition to its use as a vehicle occupant protection, at the same time for varying the backrest width of the seat. For this purpose, the vehicle seat on a gas generator for the airbag function and an air pump for backrest width adjustment.

The EP 1 559 622 A2 relates to a vehicle occupant protection device, which may be formed for example as a side airbag. The airbag can be transferred by filling into a reversible collision preparatory state and into a collision state. In order to return the airbag from the collision preparatory state to the initial position, the device has a driving element, such as a spring or a rubber band.

The DE 197 57 533 A1 relates to a safety vehicle seat which, in the event of a rear impact, is intended to ensure that the distance between the head of an occupant and the headrest of the vehicle seat is reduced. For this purpose, a fillable with a flowable medium element in the headrest is provided, which is connected to a reservoir located in the backrest. If a force is introduced into the seat via the back of the occupant, a portion of the flowable medium is thereby displaced into the headrest.

The DE 10 2005 059 997 A1 relates to a multi-chamber airbag, wherein at least two chambers via a tear seam o.ä. connected to each other. The thereby separated smaller volume can be reversibly filled with a gas to fulfill a comfort function. In the case of an accident, the smaller volume is subjected to an internal pressure that ruptures the tear seam. As a result, in case of an accident, a larger airbag volume is available than would be necessary for the comfort functions.

The DE 197 46 387 A1 relates to an airbag device which is disposed within the seat back of a motor vehicle. The airbag is located in a module housing which has a cover and tear lines. If, as a result of an accident, the lid can not open, for example, due to a blockage, the pressure of the airbag leads to a rupture of the housing at the tear lines.

The WO 01/49 535 A1 relates to an airbag device in a vehicle seat, wherein the device has a tether, which ensures that the airbag a designated position relative to the Vehicle seat occupies and this gives more stability in the position.

The US 2006/01137767 A1 relates to a vehicle seat assembly including an airbag guide that causes the airbag to expand in a given direction when inflated.

The object of the present invention is to provide an improved motor vehicle seat, with which a multi-stage, situation-adapted filling of the airbag is facilitated.

According to the invention this object is achieved by a safety device having features of claim 1 and a motor vehicle seat having the features of claim 10. Advantageous embodiments and further developments of the invention are listed in the subclaims.

The safety device according to the invention for a padded motor vehicle seat with an airbag, which is coupled to a gas generator, which is activated in the presence of sensor data on an accident or an imminent accident and filled and deployed the airbag with gas, and with an activator on the airbag is additionally repeatedly reversibly filled with gas, wherein the airbag is designed as a one-chamber airbag, provides that the airbag has at least one elastic component that brings the airbag after filling by the activator back to its original position and a tether the elastic component is formed, and that in or on the airbag, an inelastic tether is arranged, wherein the inelastic tether has a greater length than the maximum length of the elastic tether. By this arrangement and configuration of the airbag, it is possible that in a motor vehicle seat three functions can be realized in a simple manner. To increase the side guide, for example, when driving on a winding road, the airbag can be inflated with a small volume of air through the activator in a comfort function. This increases the rigidity, in particular of the side cheeks, so that an improved lateral support of the seat occupant is achieved. Likewise, by alternately inflating and venting compressed air from the airbag, a massage function can be realized within the framework of the comfort function. If the sensors detect an impending accident within the vehicle safety system, a larger amount of air in relation to the comfort function is introduced into the airbag via the activator. In particular, the backrest contours change, preferably on both sides, in order to provide an improved connection of the seat occupant to the vehicle seat. As a result, the relative movements between the seat occupant and the seat are restricted, which leads to increased safety and improved positional stability of the seat occupant on the seat. If the pre-crash state does not result in an accident, simply by switching off the activator by contracting the elastic component, the compressed air can be forced out of the airbag without the activator having to pump out the air. If an accident occurs, in addition to the activator, a gas generator is ignited, which fills the already pre-filled airbag with deployment gas so that it can escape from the motor vehicle seat and extend between a vehicle structure and the seat occupant. In the context of the comfort and pre-crash function, an elastic deflection of the airbag and an expansion of the elastic component can occur, which is reversible, so that the starting position is taken again without further action after switching off the activator.

In an embodiment not encompassed by the invention, it is provided that the airbag material forms the elastic component, for example in that a part of the airbag material is elastic or the airbag cover is provided with an elastic strip. The entire airbag may be made of an elastic material.

According to the invention, however, it is provided that at least one elastic tether forms the elastic component. This tether is preferably arranged inside the airbag and pulls the airbag back to its original position after completion of the pre-crash function or the comfort function.

Preferably, the airbag is designed as a side airbag and is located in a side wall of the vehicle seat, for example in a side cheek of the seat back or the seat cushion.

In order to allow the airbag to emerge more easily from the upholstery or the motor vehicle seat, a predetermined tear point or a predetermined tear seam is arranged in the upholstery cover, by means of which a defined exit point and a predetermined, rough orientation of the exit direction is provided.

The activator is designed as an electric pump and may be reversible, in order to suck the compressed gas from the airbag again, if necessary. Alternatively, the activator is designed as a compressed gas storage of metal, plastic or a reinforced rubber hose with a control valve.

According to the invention it is provided that in or on the airbag, an inelastic tether is arranged, which may be provided as a control aid and deployment limitation. Because the elastic Section is formed as an elastic tether, it is provided that the inelastic tether has a greater length than the maximum length of the elastic tether, so that the inelastic tether is effective only after destroying the elastic tether.

The airbag may be covered by a dimensionally stable cap and is preferably housed in a shell. The visible, dimensionally stable cap makes it easier to assemble the entire safety device. Alternatively, it is provided that the airbag is arranged in a soft envelope, which has a certain flexibility or elasticity, so that the airbag can perform the corresponding volume changes.

The airbag and the gas generator and the activator are preferably arranged on a seat frame, wherein the activator and the gas generator form different components. The airbag may be gas-tight in order to refill after filling with compressed gas through the activator no or only a small amount of gas. The gas-tightness may be achieved by a corresponding coating or insert disposed in an airbag fabric, for example a plastic elastic bag.

• 1- eine Schnittansicht durch einen Teil eines Kraftfahrzeugsitzes in einer Ausgangsstellung;
• 2 - eine Schnittdarstellung eines Teils eines Kraftfahrzeugsitzes mit aktivierter Komfortfunktion;
• 3 - einen Teil eines Kraftfahrzeugsitzes mit aktivierter Pre-Crash-Funktion; sowie
• 4 - einen vollständig entfalteten Airbag.

Hereinafter, an embodiment of the invention will be explained in more detail with reference to the accompanying figures. Show it:

• 1 - A sectional view through a part of a motor vehicle seat in a starting position;
• 2 a sectional view of a part of a motor vehicle seat with activated comfort function;
• 3 - A part of a motor vehicle seat with activated pre-crash function; such as
• 4 - a fully deployed airbag.

In the 1 is a part of a motor vehicle seat 1 shown in a schematic sectional view. The part of the vehicle seat 1 may be formed both as a seat back and a seat cushion and has a seat frame 2 on top of a cushion 3 is surrounded. The seat frame 2 is arranged in the region of a seat cheek, which projects beyond a seat or a backrest. The supernatant of the seat cheeks ensures a certain amount of lateral guidance of the seat occupant at lateral accelerations.

On the seat frame 2 is an airbag 5 together with a gas generator 6 arranged. About the gas generator 6 In the case of an accident based on sensor data, deployment gas is released into the airbag 5 initiated. In addition to the gas generator 6 is the airbag 5 in fluid communication with an activator 8th , in this case an electric pump, via the compressed gas, preferably ambient air, via a supply line 14 in the airbag 5 can be initiated. In the reference 4 of the motor vehicle seat may be a Sollrissnaht or a Sollrissstelle be formed by the directed leakage of the airbag 5 is enabled in the deployment state.

To increase the comfort, for example to realize a massage function or to increase the stiffness of the seat back, air can through the activator 8th in the airbag 5 be pumped into it. This comfort feature is in the 2 shown in which it can be seen that the airbag 5 assumed a larger volume, but the outer contour of the seat back has not or only slightly changed. The seat back has been only stiffened. Due to the increase in volume became an elastic tether 9 , which serves as an elastic component, elongated and elastically deformed. Inside the airbag 5 is another catch strap 10 arranged from an inelastic material. The elastic tether 9 and the inelastic tether 10 have different lengths, the function of the inelastic tether 10 will be explained later.

After completion of the comfort function is by the elastic component 9 , in the present case by the tether 10 , the airbag 5 back to its starting position according to 1 withdrawn.

In the 3 is the state shown in the presence of sensor data that indicate an imminent accident. The airbag 5 is compared to 2 much more inflated, the elastic tether 9 is tense, preferably so taut that further elastic stretching can not occur. By appropriate selection of the elastic component 9 It is possible to limit the maximum extent in the pre-crash function by changing the resistance to the gas pressure of the activator 8th is determined. In this way it is possible to easily control the activator 8th provide that does not require a sensor for a maximum pressure. The maximum expansion is via the elastic component 9 or the elastic components limited by the activator 8th a pressure below the restoring force of the elastic component 9 supplies, so that about the design of the elastic component 9 or the tether 9 the maximum extent of the airbag 5 is set in a pre-crash function. In the comfort as well as in the pre-crash function there is only an elastic deformation of the tether 9 instead, so that always a provision to the starting position according to 1 can be done. Alternatively to one inside the airbag 5 arranged tether 9 can also strip of material inside the airbag 5 that are part of the airbag cover, or the airbag 5 be elastic as a whole. It is also possible that the airbag 5 on the outside of one or more elastic elements, e.g. B. elastic bands, which is on the frame 2 are attached. These elastic bands then the airbag 5 back to the starting position according to 1 pushed back. The volume changes for the comfort function and for the pre-crash function are reversible.

If an accident scenario is sensed, the separate gas generator 6 activated, either without activation of the activator 8th or, if already the pre-crash state is detected, after a previous filling of the airbag 5 with a relatively small amount of compressed gas. This prefill becomes a quick reaction of the airbag 5 , which is preferably designed as a side airbag, guaranteed.

In the 4 is a deployed airbag 5 after ignition of the gas generator 6 shown. The airbag 5 is inflated to a maximum volume that is significantly above the volume according to the pre-crash function 3 lies. The 4 it can be seen that the elastic component 9 about the maximum elastic strain according to 3 was lengthened so that the material fails and the tether 9 torn. This may cause the airbag 5 further forward from the upholstery 3 and by the reference 4 through in the desired direction. The essentially inelastic trained second tether 10 limits the maximum extent in the main deployment direction of the airbag 5 and at the same time contributes to some stabilization and orientation of the deployed airbag 5 at. While the states according to 2 and 3 are reversible, after activation of the gas generator 6 a part of the seat cheek and the seat cover 4 destroyed, as is the elastic component 9 changed irreversibly, so that after an accident, an exchange of the seat or the seat component has to be made.

With the illustrated embodiment, it is possible with only one chamber or only one airbag 5 to cover three different functions, namely the reversible comfort and pre-crash functions and the accident function with an escaping airbag 5 , There are no additional components required for the comfort or pre-crash functions, which reduces material and assembly costs. Also, by the elastic component 9 a counterforce against the filling pressure of the activator 8th provided, via which the maximum deployment volume for the reversible states can be controlled.

Claims (10)

Safety device for a vehicle seat (1) provided with a cushion (3) with an airbag (5) which is coupled to a gas generator (6) which is activated in the presence of sensor data on an accident or an imminent accident and the airbag (5 ) filled with gas and unfolded, and with an activator (8) through which the airbag (5) is additionally repeatedly reversibly filled with gas, wherein the airbag (5) is formed as a single-chamber airbag (5), characterized in that the Airbag at least one elastic component (9) which brings the airbag (5) after filling by the activator (8) back to its original position and a tether (9) forming the elastic component, and in or on the airbag (5 ) an inelastic tether (10) is arranged, wherein the inelastic tether (10) has a greater length than the maximum length of the elastic tether (9). Safety device after Claim 1 , characterized in that the airbag (5) is designed as a side airbag. Safety device after Claim 1 or 2 , characterized in that in a cushion cover (4) is arranged a predetermined tear point or Sollrissnaht. Safety device according to one of the preceding claims, characterized in that the activator (8) is designed as an electric pump or as a memory made of metal, plastic or a reinforced rubber hose with a control valve. Safety device according to one of the preceding claims, characterized in that the airbag (5) is covered by a dimensionally stable cap. Safety device after Claim 5 , characterized in that the airbag (5) is partially housed in a shell. Safety device according to one of Claims 1 to 4 , characterized in that the airbag (5) is arranged in a soft wrapping. Safety device according to one of the preceding claims, characterized in that the airbag (5) and the gas generator (6) are fastened to a seat frame (2). Safety device according to one of the preceding claims, characterized in that the airbag (5) is formed from a gas-tight material. Motor vehicle seat with a safety device according to one of the preceding claims.

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