Abstract:
The present invention relates to an interior trim component for a motor vehicle, in particular a dashboard, adapted for covering an airbag. The trim component is adapted to break along a main weakening line during deployment of the airbag, said trim component comprising an inside area relative to the main weakening line which defines a flap intended to extend over the airbag. The trim component comprises a notched element comprising a plurality of disjoint notches following one another along the main weakening line and having a generally concave shape relative to the inside area.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an interior trim component for a motor vehicle, in particular a dashboard, adapted for covering an airbag. 
       BACKGROUND OF THE INVENTION 
       [0002]    Already known to the state of the art is an interior trim component for a motor vehicle, in particular a dashboard, adapted for covering an air bag, said trim component being adapted to break along a main weakening line during deployment of the airbag, said trim component comprising an inside area relative to the main weakening line which defines a flap intended to extend over the airbag. 
         [0003]    Document DE 10 2006 062 642 B3 describes an example of such an interior trim component for a motor vehicle. Specifically, document DE 10 2006 062 642 B3 describes a dashboard covering an airbag. The dashboard comprises multiple elements forming superimposed layers. One of these elements forms the dashboard body and comprises a plurality of circular marks which form a weakening line. The dashboard defines a flap intended to extend over the airbag. When a force acts on the flap, the dashboard breaks along the weakening line and releases the airbag. This type of interior trim component is already used in vehicles and is satisfactory. However, to reduce the risk of injury to the vehicle occupants while enhancing the appearance of such a component to a vehicle passenger, the present invention aims to improve it. 
       OBJECTS AND SUMMARY OF THE INVENTION 
       [0004]    To this end, according to the invention, a trim component such as above-described comprises a notched element comprising a plurality of disjoint notches following one another along said main weakening line and having a elongated generally concave shape when viewed from the inside area of the main weakening line. 
         [0005]    With these features, the trim component breaks apart more easily when a force releasing the airbag is exerted, and in particular provides better consistency (reproducibility) in the force required to release the airbag by following the main weakening line more closely. Passenger safety is therefore increased. Indeed, the shape of the notches ensures continuity in the breaking motion along the pre-established break line and thus withdraws any risk of the trim component breaking beyond this main weakening line. In addition, the plurality of notches defines a discrete pattern that is substantially invisible to a passenger in the vehicle, and the discontinuity of the notches prevents the notches from “opening” or deviating during the lifetime of the vehicle, thus preserving the aesthetic appearance of the flap. 
         [0006]    In preferred embodiments of the invention, one or more of the following arrangements may be used: 
         [0007]    said main weakening line comprises a main portion that is substantially U-shaped comprising a base, a first side arm, and a second side arm, said first and second side arms being opposite to one another, and said plurality of notches is located at least in an interface area located in the vicinity of the base and the first side arm. The orientation of the notches in the interface area located in the vicinity of the base and the first side arm ensures continuity in the breaking motion along the weakening line and limits the risk of deviation; 
         [0008]    the U-shaped main portion of the main weakening line extends between a first weakening end which is part of the first arm and a second weakening end which is part of the second arm, said notches each include a first notch end and a second notch end, the first notch end being closer to the first weakening end than the second notch end, and said notches each extend tangentially to the main weakening line in the vicinity of their first end; 
         [0009]    the plurality of disjoint notches extends all the way to the first weakening end; 
         [0010]    the main weakening line further comprises an interface portion beveled extending between the first side arm and the base, and into which said main portion extends. The interface portion ensures a simplified propagation of the breaking motion; 
         [0011]    each of the notches comprises a first segment and a second segment forming between them in the inside area an obtuse angle that is strictly less than 1 80  degrees, and preferably between 105 degrees and 165 degrees. The notches are thus easily created on the trim component, and the angle between the first and second segments is particularly advantageous for achieving a non-abrupt change in the direction of the breaking motion; 
         [0012]    said plurality of notches includes an interface notch comprising a third segment, the first segment being arranged between the second segment and third segment, and the first segment and third segment forming a non-zero angle relative to one another and both extending along the main weakening line. The interface notch created by the three segments here again allows achieving a non-abrupt change in the direction of the breaking motion; 
         [0013]    the notches have an identical width and an identical depth in the first segment and in the second segment. They are thus easily realized by known production methods; 
         [0014]    the main weakening line is symmetric with respect to a line median plane and said plurality of notches is arranged symmetrically with respect to said line median plane along said main weakening line. This symmetry ensures regularity in the breaking motion in two different directions; 
         [0015]    the trim component further comprises a dashboard body and the notched element is formed by a motor vehicle dashboard skin covering the dashboard body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Other features and advantages of the invention will become apparent from the following description of one of its embodiments, given by way of non-limiting example with reference to the accompanying drawings. 
           [0017]    In the drawings: 
           [0018]      FIG. 1  is a schematic perspective view of passenger compartment of a vehicle equipped with an interior trim component according to the invention; 
           [0019]      FIG. 2  is a schematic view of the main weakening line of the interior trim component of  FIG. 1 ; 
           [0020]      FIG. 3  is an enlarged sectional view along line III-III of  FIG. 2 ; 
           [0021]      FIG. 4  is an enlarged view of region IV of  FIG. 2 ; 
           [0022]      FIG. 5  is a schematic sectional view of an “injection molded” dashboard; 
           [0023]      FIG. 6  is a schematic sectional view of a “thermo coated” dashboard; 
           [0024]      FIG. 7  is a schematic sectional view of a “padded” dashboard. 
       
    
    
       [0025]    In the various figures, the same references are used to refer to identical or similar elements. 
       DETAILED DESCRIPTION 
       [0026]      FIG. 1  schematically represents the interior of a vehicle equipped with an interior trim component. 
         [0027]    The trim component is a dashboard  1  comprising a notched element  100 . In alternative embodiments, the interior trim component of the vehicle could be a door panel, a roof lining, a seat, or any other type of trim element equipping the inside of a vehicle. 
         [0028]    The notched element  100  of the dashboard comprises an outside surface, possibly visible to a passenger of the vehicle and facing the vehicle seating area, and an inside surface that is opposite the outside surface. As shown in  FIG. 1 , the notched element  100  of the dashboard comprises a plurality of disjoint notches following one another  10  along a main weakening line  3 , also called the line of least resistance. 
         [0029]    The main weakening line  3  forms a general U-shape and defines an inside area I relative to the main weakening line  3 , which forms a flap covering the airbag. When a force is applied, the airbag  2  deploys and the notched element  100  of the dashboard breaks along the main weakening line  3 . 
         [0030]    The main weakening line comprises a main portion that is substantially U-shaped with a base  31  and two side arms  32 ,  33 . The side arms  32 ,  33  are opposite each other, connected by the base, and the base and the two side arms  32 ,  33  define the inside area I. The U-shaped main portion extends between a first weakening end  34  and a second weakening end  35 . The first weakening end  34  is part of the first arm  32 , while the second weakening end  35  is part of the first arm  33 . In the figure, the main weakening line is symmetric about a line median plane P. 
         [0031]    In the embodiment illustrated in  FIG. 2 , the main weakening line  3  also comprises a first interface portion  36  beveled extending between the first side arm  32  and the base  31 . Symmetrically, the main weakening line  3  comprises a second interface portion  37  beveled extending between the second side arm  33  and the base  31 . In other words, the base  31  extends in a transverse direction Y, the first arm extends in a first lateral direction X 1 , and the first interface portion (also called the extension portion) extends in a first extension direction D 1 . The first extension direction D 1  forms a non-zero angle with the first lateral direction X 1  and with the transverse direction Y. Preferably, the second side arm extends in a second lateral direction X 2  parallel to the first lateral direction X 1  and perpendicular to the transverse direction Y. 
         [0032]    In another embodiment, not shown, the first lateral direction X 1  and the second lateral direction X 2  may not be parallel and may thus form a main weakening line that is substantially trapezoidal in shape. Similarly to the above, the second interface portion (also called the extension portion)  37  extends in a second extension direction D 2  forming a non-zero angle respectively with the first and second lateral directions X 1 , X 2 , the transverse direction Y, and the first extension direction D 1 . 
         [0033]    The main weakening line  3  has been described as being U-shaped, but equally advantageously it may have the shape of an H, an I, two U facing each other with a common portion or forming an envelope or any other shape appropriate for the opening of the flap covering the airbag. 
         [0034]    Each notch  10  has an elongated and substantially concave shape in the direction of the inside area I defined by the break line. More specifically, each notch has a shape that substantially curves inwards relative to the inside area I. In other words, each notch angles towards the inside area I. Each notch comprises first and second notch ends, and the first notch end is tangent to the main weakening line  3 , while the second notch end is located within the inside area I. The second notch end is closer to the base  31  than the first notch end. For example, each notch extends at least partially in a direction which is toward the inside area I. In addition, each notch  10  also extends partially along the main weakening line  3 . 
         [0035]    More particularly, as shown in  FIGS. 2 and 4 , each notch  10  comprises a first segment  11  and second segment  12 . The first and second segment together form in the inside area I a non-zero obtuse angle A that is strictly less than 180°. Preferably, the angle A is between 105° and 165°, for example about 135°. The first segment  11  is connected to the second segment  12  by a protruding edge. 
         [0036]    Alternatively, the first segment  11  may be connected to the second segment  12  by a curved portion. The first segment  11  extends along the main weakening line, while the second segment  12  is located within the inside area I. 
         [0037]    As represented in  FIG. 2 , the notches lie in succession along the break line, between the first and second weakening ends  34 ,  35 . More particularly, in the region of the first arm  32 , the notches  10  have a first segment  11  extending substantially along the first lateral direction X 1  and a second segment  12  extending substantially in a first propagation direction. As shown in  FIG. 2 , the first propagation direction is parallel to the first extension direction D 1 . The notches in the vicinity of the second arm  33  have a first segment  11  extending substantially along the second lateral direction X 2  and a second segment  12  extending substantially in a second propagation direction. 
         [0038]    As represented in  FIG. 2 , the second propagation direction is parallel to the second extension direction D 2 . The notches in the region of the base  31 , between the first intermediate portion  36  and the point of intersection of the line median plane P and the weakening line, have a first segment  11  extending substantially in the transverse direction Y and a second segment  12  extending in a direction, for example a direction parallel to the second propagation direction D 2 . 
         [0039]    By symmetry relative to the line median plane P, the notches between the second intermediate portion  37  and the point of intersection of the line median plane P and the break line  11  have a first segment extending substantially in the transverse direction Y and a second segment  12  extending in a direction that is for example parallel to the first propagation direction D 1 . As for the notches in the region of the first interface portion  36 , they have a first segment  11  extending in the extension direction D 1  and a second segment  12  extending in the transverse direction Y. 
         [0040]    In a variant embodiment, the plurality of notches  10  is located on the first intermediate portion  36  or on the second intermediate portion  37  or in the vicinity of the first intermediate portion  36  or in the vicinity of the second intermediate portion  37 . 
         [0041]    In the case represented here, the plurality of notches  10  comprises a first interface notch  101 , a second interface notch  102 , a third interface notch  103 , and a fourth interface notch  104 . The first, second, third and fourth interface notches  101 ,  102 ,  103 ,  104  are respectively arranged between the first arm  32  and the first interface portion  36 , between the second arm  3 ′ 3  and the second interface portion  37 , between the second interface portion  37  and the base  31 , and between the base  31  and the first interface portion  36 . 
         [0042]    Each interface notch, as represented in  FIG. 2 , comprises a third segment  13 , the first segment  11  being arranged between the second segment  12  and the third segment  13 . The first and third segments  11 ,  13  form a non-zero angle relative to each other, preferably an obtuse angle strictly less than 180°. For example, the third segment  13  of the first interface notch  101  extends in the first lateral direction X 1 , the third segment  13  of the second interface notch  102  extends in the second lateral direction X 2 , the third segment  13  of the third interface notch  103  extends in the second extension direction D 2 , and the third segment  13  of the fourth interface notch  104  extends in the first extension direction D 1 . 
         [0043]    The notches  10  are made in the inside area of the notched dashboard element  100 . The notches  10  are preferably made by a temperature-controlled heated blade that is pressed into the notched dashboard element  100 . The blade is discontinuous to correspond to the notches described above and represented in  FIG. 2 . Alternatively, the notches  10  are made using a laser beam or a similar method. The notches are made within the thickness of the dashboard element and have a constant width and depth along their entire length. 
         [0044]      FIG. 3  schematically represents a portion of the dashboard element (or notched element)  100  in a sectional view. The notched element has a total thickness E and the notch has a depth (or thickness) p. The depth p is of course less than the total thickness E. In addition, a residual thickness e is defined by the difference between the total thickness E and the depth p. Preferably, the depth p represents between 50% and 100% of the total thickness E, advantageously between 70% and 90% of the total thickness E. As represented in  FIG. 3 , the residual thickness e is not zero. In an alternative embodiment, the residual thickness e could be zero and the depth p of the notch is the same as the total thickness of the dashboard. Advantageously, the residual thickness e is less near the line median plane than near the first and second side arms  32 ,  33 . Thus, the breakage of the trim component preferably occurs at the line median plane P and propagates along the main weakening line to the first and second weakening ends  34 ,  35  as represented in  FIG. 2  by arrows R1 and R2. 
         [0045]    In a preferred embodiment, and as represented in  FIG. 7 , the dashboard is of the “padded” type and comprises a dashboard body  40  forming a rigid support layer, a foam layer  50 , and a skin  60  covering the foam layer  50 . The airbag safety system  2  (see  FIG. 1 ) is housed under the dashboard body  40 . The dashboard body is then for example made by injection molding and is made of thermoplastic material, for example such as polypropylene PP with or without reinforcing fibers or inorganic filler depending on the rigidity desired. The foam layer is made of polyurethane for example, and the dashboard element (or skin) is for example of polyvinyl chloride (PVC), thermoplastic polyolefin (TPO), polyurethane (PU), leather, or leather substitute. In this embodiment, the notched element  100  corresponds to the skin  60 . In the embodiment illustrated, the dashboard body has a continuous notch. However, in alternative embodiments, the dashboard body could comprise the notched element  100 , as described above, in addition to or instead of the skin  60 . 
         [0046]    In a first variant embodiment, and as represented in  FIG. 5 , the dashboard is an “injection molded” dashboard consisting of a dashboard body  40  which constitutes the sole element of the dashboard. In this variant embodiment, the notched element  100  corresponds to the dashboard body  40 . 
         [0047]    In a second variant embodiment, and as represented in  FIG. 6 , the dashboard is a “thermo coated” dashboard comprising a dashboard body  40 , the dashboard further comprising a self-splitting skin  60  covering the dashboard body. In this second variant, the notched element  100  corresponds to the dashboard body  40 . The residual thickness e is zero and the notch depth p is the same as the total thickness E of the dashboard body. In this case, the notch passes through the thickness of the notched element and extends from the inside surface to the outside surface of said element. This variant embodiment is advantageous in the case of a skin made of “self-sealing” material, for example PVC, covering the dashboard body. 
         [0048]    Of course, the invention is not limited to the embodiment described by way of illustration and not of limitation. In particular, instead of being formed of segments, the notches may have an elongated shape that is entirely or partially curved, of constant or variable curvature, instead of being formed of straight sections as illustrated in  FIGS. 2 and 4 . However, in the invention, the notches do not have any reversal of curvature (or inflection point).