FR2876334A1 - Air bag forming device for e.g. commercial vehicle with three front seats, has air bag with three adjoining lobes defining two hollow parts retaining passengers, where two lobes are fixed by reinforced sewing and supplied by gas diffusers - Google Patents

Abstract

The device has an inflatable air bag (16) with three adjoining lobes (20-22) defining two hollow parts (17, 18) situated in each zone joining two lobes. Each hollow part retains a passenger during an impact. Each lobe has two sidewalls and two adjoining lobes are fixed by reinforced sewing connecting the sidewalls. Two gas diffusers (26, 27) are placed at the junctions of two lobes such that each diffuser supplies two lobes with gas. The two gas diffusers (26, 27) are supplied by a gas generator (24). Independent claims are also included for the following: (A) a vehicle comprising three front seats including a driver seat, a central passenger seat and a lateral passenger seat, equipped with an air bag forming device (B) a vehicle comprising two front seats including a driver seat and a passenger seat, equipped with an air bag forming device.

Description

The invention relates to a device forming a safety cushion for

  motor vehicle, comprising at least one bag designed to inflate automatically in the event of a frontal impact to retain two occupants of the vehicle.

  The invention also relates to a vehicle equipped with such a device.

  The invention relates to devices forming a safety cushion equipping for example vehicles comprising three front seats, such as commercial vehicles, but it is not limited to this specific application and can also be applied to other types of vehicles. such as two-seater vehicles frontal.

  In the case of a vehicle with three front seats, namely a driver's seat, a passenger center seat and a passenger side seat, the safety cushion device according to the invention is provided to retain the central passenger and the passenger seat. side passenger when this air bag is inflated.

  It is known to equip such vehicles with two devices forming two independent airbags. Each device includes a gas generator and an air bag, and inflates in case of an accident, which is two cushions, one of the cushions is provided to hold the central passenger, and the other cushion is provided for hold the side passenger.

  In this case, when the two cushions are inflated, they are supported against each other, each cushion being opposite one of the passengers to hold it. However such an arrangement is not entirely satisfactory, because during inflation, the risk of interference of a bag with the other are important.

  In an unfavorable case, one of the bags inflates before the other, which prevents the other bag to position correctly in front of the corresponding passenger. Given the speed of reaction that is expected of such devices, it is not possible to synchronize satisfactorily the inflation of these two bags to avoid such interference.

  In such an unfavorable case, the two passengers do not benefit from the same level of protection, particularly if the bag retaining the central passenger does not inflate properly, the risk of injury for this passenger are greater, these risks being accentuated in that the dashboard has a high rigidity in the central area.

  It has also been envisaged solutions of dual safety cushion device called "bean".

  This solution corresponds to a device comprising a single large double inflatable bag, which occupies a space substantially equivalent to that of the two individual air bags mentioned in the previous solution.

  In this solution, the risk of interference of one bag with the other during inflation is solved. However, the size of the double bag remains limited, and once inflated it does not necessarily extend far enough towards the driver's seat.

  Thus, this solution leaves two important risks: on the one hand the central passenger can escape the safety cushion and therefore not be retained by it if it is poorly positioned or if the frontal impact pushes in an oblique direction between the conductive area and the left side of the airbag; and on the other hand, in the case where one of the passengers is offset from its nominal position, the risk of interference between the two passengers during the shock is high.

  The object of the invention is to overcome these disadvantages by proposing an airbag device solution having an increased level of safety compared to known devices.

  For this purpose, the subject of the invention is a device forming a safety cushion for a motor vehicle, comprising at least one bag designed to inflate automatically in the event of a frontal impact to hold two occupants of the vehicle, characterized in that the safety cushion has a shape with three convex lobes, each lobe extending vertically, these lobes being contiguous two by two, and defining a hollow part of the safety cushion in each zone joining two lobes, each hollow part of the safety cushion being intended to retain an occupant.

  The safety cushion has a shape that allows to maintain, in the holding phase, each occupant in a part dedicated to it, namely one of the hollow parts. In addition, two contiguous lobes are protuberances that direct the corresponding passenger in the hollow portion located between these two lobes, including in the case where the passenger is offset from the hollow portion.

  According to one embodiment of the invention, each lobe comprises two flanks, and two contiguous lobes are supported against each other by their respective flanks, when they are inflated.

  According to one embodiment of the invention, each lobe comprises a base constituting an inflation opening, and the three lobes are joined at their base to form the same inflatable bag.

  According to one embodiment of the invention, two contiguous lobes are sewn together by reinforced seams.

  According to one embodiment of the invention, the device comprises two gas diffusers for inflating the bag, each gas diffuser being positioned so as to supply gas to two contiguous lobes, and the two diffusers are powered by the same gas generator. to inflate the bag.

  The invention also relates to a vehicle comprising three front seats including a driver's seat, a central passenger seat and a side passenger seat, equipped with a device as defined above, and configured to retain the central passenger and the side passenger.

  The invention also relates to a vehicle comprising two front seats including a driver's seat, and a passenger seat, equipped with a device as defined above, shaped to hold the driver and the passenger.

  The invention will now be described in more detail and with reference to the accompanying drawings which illustrate an embodiment thereof by way of non-limiting example.

  - Figure 1 is a schematic representation of an airbag device of the state of the art; - Figure 2 schematically shows an airbag device according to the invention.

  Figure 1 schematically shows a front part 1 of a passenger compartment of a motor vehicle equipped with three front seats in which three occupants are positioned. These three front seats include a driver's seat 2, a central passenger seat 3 and a lateral passenger seat 4.

  References 2, 3 and 4 correspond to the seat backs of these seats, the corresponding occupants being marked by 5, 6 and 7. The place of the driver 5 is equipped with a conventional air bag device 8 which is mounted in the flywheel 9, and which is here shown in an inflated state.

  This vehicle also comprises another safety cushion device 10 provided for retaining the central passenger 6 and the lateral passenger 7 in the event of an impact. This device mainly comprises an air bag 11 and a gas generator 12 which acts in the event of shock detection.

  As shown diagrammatically in this figure, this device 10 is positioned on the dashboard substantially facing the space between the central square 3 and the side square 4. The bag 11 has a form called bean, which is deployed symmetrically with respect to the gas generator 12, so that it constitutes a cushion having a left portion in the figure for retaining the central passenger 6, and a straight portion 7 for retaining the lateral passenger 7.

  As can be seen in this figure, in the event of frontal impact in an oblique direction, there is a significant risk that the central passenger 6 is directed between the two cushions 8 and 11 and is therefore not retained.

  On the other hand, the risk of interference between the two passengers 6 and 7 when they are projected towards the cushion 11 is important, especially since the central part of the cushion 11 may comprise a central hollow zone towards which converge the two passengers.

  Figure 2 shows the safety cushion device according to the invention, which is marked 15. This device is implanted in the dashboard 13 substantially at the same location as the device 10 of the state of the art.

  According to the invention, this air cushion device comprises at least one bag 16, inflatable, which constitutes the airbag when inflated, this cushion having a shape including two hollow portions 17 and 18 which respectively correspond to parts intended to receive respectively the two passengers 6 and 7.

  In the event of impact, the risk of interference between the two passengers 6 and 7 is significantly reduced because two contiguous lobes constitute protuberances which direct and accompany the corresponding passenger in the hollow part situated between these two lobes, including in the case where this passenger is offset from the hollow part.

  In addition, when it is retained by the cushion, each passenger is held in position in the corresponding hollow part, because of the distribution of the forces involved by this hollow part.

  The airbag device may comprise, for example, three contiguous airbags constituting three vertical lobes, such that each zone joining two contiguous bags constitutes a hollow area of the airbag.

  Advantageously, the device comprises a single inflatable bag 16 which constitutes three contiguous vertical lobes, marked by 20, 21 and 22 also defining the two hollow portions 17 and 18 located in each zone joining two vertical lobes.

  The inflatable bag 16 of FIG. 2 is for example formed by three distinct lobes which are sewn together at their base, so as to constitute a single bag having a common inlet capable of receiving gas emitted by a gas generator which is indicated by 24 in FIG.

  The three lobes 20, 21, 22 each have a convex, oblong shape extending vertically, and defining for each lobe two side surfaces or lateral flanks extending substantially in a longitudinal vertical plane relative to the entire vehicle. As can be seen in FIG. 2, the contiguous lobes 20 and 21 have their lateral flanks, respectively right and left, resting against each other, which defines the hollow portion 17 in the form of a recess or a re-entrant angle. .

  The hollow surface 18 is similarly defined by two lateral flanks of the lobes 21 and 22 which are also supported against each other.

  Advantageously, the lobes are fixed to each other by reinforced seams binding the flanks of two contiguous lobes, to ensure the transverse retention of these lobes in case of accident, which helps to ensure that the lateral positioning of each hollow portion remains accurate in case of shock.

  The bag with three lobes which is represented in FIG. 2 is supplied with gas by two separate diffusers marked by 26 and 27 and which are each positioned substantially in line with the junction between two lobes, so that each diffuser supplies two gases with gas. lobes, which guarantees a uniform inflation of the entire bag in the event of an accident.

  These two diffusers may optionally be each powered by an independent gas generator. But advantageously, as shown in the example of Figure 2, these two diffusers are connected to the same common gas generator which feeds both gas during inflation.

  The choice of a common gas generator for the two diffusers is all the more interesting that the volume of the inflated bag of the device according to the invention is significantly lower than the volume of a conventional double bag such as that of FIG. Therefore, it is possible to implement a gas generator having a footprint smaller than those known in the state of the art for double bags.

  Typically, the volume of a lobster bag is about half that of a double bag, so-called bean, so that a single-passenger airbag device gas generator is sufficient.

  As shown in the figures, the invention applies to the case of vehicles with three front seats, but it can equally well apply to the case of vehicles having just two front seats, so as to retain the driver and passenger of such a vehicle in case of accident.

Claims (8)

  1. Device (1) forming a motor vehicle safety cushion, comprising at least one bag (16) intended to inflate automatically in the event of an impact to retain two occupants (6, 7) of the vehicle, characterized in that the cushion of security has a shape with three convex lobes (20, 21, 22), each lobe (20, 21, 22) extending vertically, these lobes (20, 21, 22) being contiguous in pairs, and defining a hollow portion (17, 18) of the safety cushion in each zone joining two lobes (20, 21, 22), each hollow portion (17, 18) of the safety cushion being intended to retain an occupant (6, 7).   2. Device according to claim 1, wherein each lobe (20, 21, 22) comprises two flanks, and wherein two contiguous lobes (20, 21; 21, 22) are supported against each other by their respective flanks, when inflated.   3. Device according to claim 1 or 2, wherein each lobe (20, 21, 22) comprises a base constituting an inflation opening, and wherein the three lobes (20, 21, 22) are joined at their base to constitute the same inflatable bag (16).   4. Device according to one of the preceding claims, wherein two contiguous lobes (20, 21; 21, 22) are sewn to each other by reinforced seams.   5. Device according to one of the claims   preceding, comprising two gas diffusers (26, 27) for inflating the bag (16), each gas diffuser being positioned to supply gas to two contiguous lobes (20, 21; 21, 22).   6. Device according to claim 5, wherein the two gas diffusers (26, 27) are fed by the same gas generator (24).   7. Vehicle comprising three frontal seating positions (2, 3, 4) including a driver's seat (5), a central passenger seat (6) and a side passenger seat (7), equipped with a device (1) according to one of the preceding claims configured to retain the central passenger (6) and the lateral passenger (7).   8. Vehicle comprising two front seats including a driver's seat, and a passenger seat, equipped with a device (1) according to one of the preceding claims configured to retain the driver and the passenger.