Abstract:
The invention relates to a method for increasing the crash resistance of a motor vehicle in the vicinity of the front bodywork pillar (A-pillar), especially as regards forces which act in conjunction with an offset front impact (offset crash) on the bodywork. The invention also refers to a blocking element, as is used in such a method, and to a motor vehicle fitted with such a blocking element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a national stage filing of PCT/DE2005/000338 filed Mar. 1, 2005 claiming priority to DE 10 2004 011 786.1 filed Mar. 9, 2004. 
     
    
     TECHNICAL FIELD  
       [0002]     The invention relates to a method for increasing the crash resistance of a motor vehicle in the vicinity of the front bodywork pillar (A-pillar), especially as regards forces which act in conjunction with an offset front impact (offset crash) on the bodywork. The invention also refers to a blocking element, as is used in such a method, and to a motor vehicle fitted with such a blocking element.  
       BACKGROUND OF THE INVENTION  
       [0003]     Future requirements to be expected of motor vehicle bodywork (crash criteria), especially as regards so-called offset crash situations, assume that with constructive means, a situation will be achieved such that even persons who are not wearing seat belts on the front seats in such an accident situation cannot come into contact with the A-pillar with their heads (head crash protection). For fulfillment of this safety requirement, it must be ensured that, in a frontal impact, the A-pillars are not, or are not noticeably, deformed into the internal space. This can be achieved thus: that a practically unavoidable gap or intervening space produced during manufacture of the bodywork between a front face of a front door and an adjoining outer side of the A-pillar is bridged at least partially with a blocking element acting as a crash support, so that the A-pillar, especially in an offset frontal impact, is promptly in contact with the front face of the door after moving previously through a minimum deformation, and supported on the latter so that, in this way, a transfer of the impact forces via the door into the rear areas of the bodywork is possible. In addition, the door or doors are at the same time strengthened adequately by construction measures such as shaft reinforcement and side impact reinforcements, in order to be capable of absorbing and transferring the forces arising safely. By means of the measures described, a movement or deformation of the A-pillar, above all of its upper part, into the internal space is avoided or reduced to a minimum, so that the risk of head injuries through impact by a deformed A-pillar is decisively reduced. However, the fitting of the blocking element cited is associated with a relatively high adaptation cost, in which the blocking element frequently does not bridge the intervening space ideally and as a consequence of this a not insignificant risk of head injuries remains.  
         [0004]     The problem for the invention is to create an improved method for increasing the crash resistance of a motor vehicle in which, in an intervening space between a front face of a front door, adjoining an A-pillar and an outer side of the A-pillar facing the former, a blocking element is fitted, in which the assembly also will be significantly eased.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     According to the invention, this problem will be solved by means of such a method, which is characterized by the following steps: provision of a blocking element, having two blocking parts, which are connected with each other such that they are movable relative to each other under the action of a setting force into an initial state, whereby a longitudinal dimension of the blocking element is adjustable, and which can be fixed relative to each other (installed state), such that a force arising in an accident acting in the direction of the longitudinal direction or force absorption direction can be absorbed; attachment of the blocking element with the vehicle door open, in which one of the blocking parts is fastened to the front face of the vehicle door or to the outside of the A-pillar and in which the blocking parts are fitted relative to each other such that the blocking element has a greater longitudinal dimension than the intervening space with the vehicle door closed; closing of the vehicle door, in which the other blocking part comes into contact with the A-pillar or the vehicle door and the blocking parts are moved automatically relative to each other into an assembly position, in which they fundamentally bridge the intervening space completely with the door closed; and fixing of the blocking parts relative to each other in the assembly position.  
         [0006]     To be fit for their purpose, the blocking components fundamentally have plane outer surfaces, with which they are seated against the vehicle door and the A-pillar or stand against these with a small separation. In order to simplify the adjustment process when closing the vehicle door, it can be stipulated that the blocking part which is not fixed to the vehicle (A-pillar or vehicle door) is slightly ball-shaped on its outer surface (convex on the outside), in order that the blocking component can roll when closing the vehicle door on the opposite surface, either the vehicle door or the A-pillar, and can be moved more easily into the assembly position. In any case, it is useful if the outer surfaces of the blocking parts are fundamentally parallel.  
         [0007]     An advantageous embodiment is characterized in that the blocking parts are formed as wedges, in which the longitudinal dimension of the blocking element is adjusted while the blocking parts are moved relative to each other at an angle to the force absorption direction of the blocking element.  
         [0008]     The blocking parts can also have mutually engaging areas, along which they are moved relative to each other to adjust the longitudinal dimension of the blocking element.  
         [0009]     Preferably, it is stipulated that the blocking parts are fixed relative to each other by means of at least one screw. In this case, it is particularly beneficial if the blocking element is attached simultaneously to the vehicle door or the A-pillar with the at least one screw.  
         [0010]     Alternatively, or in addition, it can be stipulated that the blocking parts are fixed relative to each other by welding into the assembly position. One of the blocking parts could also be welded to the vehicle door or the A-pillar.  
         [0011]     To be fit for the purpose, a separator film which, for example, can be made of plastic or rubber and having a thickness of 1 mm or 2 mm (as required), is attached before fixing to the other, i.e. the unattached blocking part, and is removed after fixing, in order to guarantee a defined minimum separation of, for example, 1 mm or 2 mm between the surface of the blocking element and the adjacent painted surface (A-pillar or vehicle door).  
         [0012]     The object of the invention is also a blocking element as crash support in a motor vehicle for bridging an intervening space between a front face of a vehicle side door adjoining an A-pillar and an outer side of an A-pillar facing the former, with two blocking parts, which are connected with each other such that they can be moved relative to each other into an initial state under the action of an adjusting force, whereby a longitudinal dimension of the blocking element is adjustable, and which can be fixed relative to each other in an assembly position, so that in an initial state a force arising in a crash in the direction of the longitudinal dimension or force absorption direction can be absorbed.  
         [0013]     In one version, a pre-tensioned spring fitted between the blocking parts can be stipulated, by which the blocking parts are pre-tensioned into a position in which the blocking element has a maximum longitudinal dimension.  
         [0014]     To be fit for the purpose, the blocking parts fundamentally have plane or one plane and one slightly ball-shaped (convex on the outside) outer surface(s), with which they sit against the vehicle door and the A-pillar or are opposite these with minimum separation. To be fit for the purpose, the outer surfaces are fundamentally parallel.  
         [0015]     Preferably, it is stipulated that the blocking parts are formed as wedges, in which the longitudinal dimension of the blocking element is adjustable by lengthening the blocking parts relative to each other at an angle to the force absorption direction. Co-operating wedge-shaped surfaces or other surfaces, along which the blocking parts can be moved, can be provided with projections such as corrugations, or similar devices, in order to prevent unwanted movement after fixing.  
         [0016]     It can be useful if the blocking parts have mutually engaging areas, along which they can be moved relative to each other, whereby the longitudinal dimension of the blocking element is adjustable.  
         [0017]     Preferably, it is stipulated that the blocking parts can be fixed relative to each other in the assembly position by at least one screw. It is particularly beneficial if the blocking element can be attached simultaneously to the vehicle door or the A-pillar by means of the at least one screw.  
         [0018]     Alternatively, or in addition, it can be stipulated that the blocking parts can be fixed relative to each other in the assembly position by welding.  
         [0019]     The invention also refers to a motor vehicle with a side vehicle door fitted behind an A-pillar in which, in an intervening space between a front face of the vehicle door and an outer side of the A-pillar opposite, a blocking element bridging the intervening space when the door is closed is fitted as crash support, in which the motor vehicle is characterized by a blocking element according to the invention, in which one of the blocking parts is fixed to the front face of the vehicle door or to the outside of the A-pillar and the blocking element bridges the intervening space when the door is closed completely.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     Other advantages and features of the invention will become clear from the following description of specimen embodiments, in which reference will be made to a drawing, in which:  
         [0021]      FIG. 1  shows an isometric view of a motor vehicle which is fitted with a blocking element according to the invention as crash protection,  
         [0022]      FIG. 2  shows an isometric view of the area of the blocking element from  FIG. 1  to a larger scale,  
         [0023]      FIG. 3  shows a similar view to that in  FIG. 2 , again to a larger scale,  
         [0024]     FIGS.  4  to  6  show various views of the blocking element according to the invention depicted in FIGS.  1  to  3 ,  
         [0025]      FIG. 7  shows a version of the invention in a sectional view in the horizontal plane, and  
         [0026]      FIG. 8  shows another version of the invention in a sectional view in the horizontal plane. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]     Initially, reference is made to FIGS.  1  to  3  in which, in simplified schematic representations, a motor vehicle fitted with a blocking element according to the invention is illustrated and with the aid of which the method according to the invention will be explained.  
         [0028]      FIG. 1  shows in an isometric view a motor vehicle  1  with a side vehicle door  2  and an A-pillar  4  fitted in the frontal area, which is continued in its upper area in the form of a windscreen frame  6 . Conditioned by design, there is on all sides between the vehicle door  2  and the surrounding bodywork areas, also therefore in the vicinity of the A-pillar  4 , a gap or intervening space, which on one hand is unavoidable, in order to avoid unwanted contacts between vehicle door and bodywork and, on the other hand, is used to house seals.  
         [0029]     As  FIGS. 2 and 3  show, there is such an intervening space  14 , in the side areas of which are fitted seals  16 , between a front face  10  of the vehicle door  2  and an outer side  12  of the A-pillar  4  (facing against the direction of travel  20 ).  
         [0030]     As  FIG. 3  shows particularly clearly, there is in the intervening space  14  a blocking element  18  according to the invention, which is adapted such that its longitudinal dimension L (measured in the direction of travel  20 ) practically equals the corresponding longitudinal dimension L 1  of the intervening space  14 , i.e. L 1  is equal to L plus a defined smaller space d of approximately 1 to 2 mm, so that the blocking element  18  bridges the intervening space  14  in the longitudinal direction or in the direction of travel  20  almost completely, and is on one hand in contact with the front face  10  of the vehicle door  2  and on the other hand almost in contact with the outside  12  of the A-pillar  4 , when the vehicle door  2  is closed. This guarantees that, in an accident, the forces arising and acting against the direction of travel  20  (force absorption direction  22 ) can be transferred directly via the blocking element to the vehicle door  2  and thus can be captured, so that the A-pillar fundamentally maintains its upright position.  
         [0031]     To explain the blocking element  18 , reference is made to FIGS.  4  to  6 , in which are depicted various views of one embodiment.  FIG. 4  shows a plan view in the direction IV in  FIG. 3 , whereas  FIG. 5  shows a side elevation in the direction V in  FIGS. 3 and 4 , and  FIG. 6  shows an isometric view corresponding to  FIG. 3 .  
         [0032]     The blocking element  18  consists of two blocking parts  24  and  26 , having mutually engaging wedge-shaped areas  24   a ,  26   a  and capable of being fixed to each other and relative to each other with a fixing screw  28 , as well as capable of being fixed to the front face  10  of the vehicle door  2 . As is clear from  FIG. 4 , the blocking parts  24 ,  26  can be moved relative to each other in the direction of the arrows  30 ,  32  into an initial state with a slackened or slightly tightened fixing screw  28 , whereby the mutual separation of the outer surfaces  34 ,  36 , which corresponds to the longitudinal dimension L, can be increased. Vice versa, by pushing the blocking parts apart against the directions  30 ,  32 , the mutual separation of the outer surfaces (longitudinal dimension) can be reduced, until the state depicted in  FIG. 4  with the smallest dimension L is achieved. In any movement position, the set longitudinal dimension L can be fixed by tightening the fixing screw(s)  28  (installed state), in which, by means of the wedge-shaped design and, if need be, projections such as corrugations or similar devices on the wedge-shaped surfaces, it is ensured that even large forces acting in the force absorption direction  22  on the outer surfaces  34 ,  36  can be safely absorbed, without any fresh movement of the blocking parts relative to each other occurring.  
         [0033]      FIG. 4  shows by way of a hint a spring  38 , which acts between the blocking parts and pre-tensions these in a position in which the blocking element assumes its maximum longitudinal dimension, but in any case a longitudinal dimension which is greater than L 1  or at least equal in size.  
         [0034]     As is hinted in  FIG. 1 , it is useful to house the blocking element  18  in the area between an upper and a lower door hinge, in order first to achieve as high a fitting position as possible, because the forces to be expected can be best absorbed higher up above the door breasting. A height H of the blocking element  18 , as hinted in  FIG. 6 , should therefore correspond to as great a portion as possible of the total door height, for example, 50%, 60%, or even 75% or more.  
         [0035]     The blocking element  18  according to the invention is installed in a vehicle as follows. Before installing the blocking element, the vehicle door  2  is installed in the body shell and its join matched to the body shell. The blocking element is then pre-fitted on the front face  10  of the vehicle door in the initial state, i.e. the fixing screw(s)  28  is (are) tightened slightly, so that the blocking parts are attached to the door, but can still be moved relative to each other by a certain setting force ( FIG. 4 ) acting in the force absorption direction  22 . As an alternative to a slight tightening of the screw(s)  28 , a spring  38  can be provided. A separator strip  40  ( FIG. 4 ) is attached to the exposed outside  36  of the blocking part  26 .  
         [0036]     At the same time, a longitudinal dimension L is set, which is larger than the corresponding longitudinal dimension L 1  of the intervening space  14 . The vehicle door  2  is then closed, in which the blocking part  26  facing the A-pillar  4  comes into contact with its outer surface  36  or the separator strip  40  against the outside  12  of the A-pillar  4  before the door is completely closed. By closing the door further, an adjusting force is produced acting in the force absorption direction  22 , by which the blocking part  26  is moved against the direction of the arrow  30  shown in  FIG. 4  relative to the blocking element  24  connected with the door and the longitudinal dimension L of the blocking element (including the separator strip if relevant) is reduced automatically, until it almost exactly equals the longitudinal dimension L 1  of the intervening space  14  with the door closed completely.  
         [0037]     The vehicle door is then opened and the installed state produced, i.e. the fixing screw(s)  28  is/are tightened firmly. Should a noticeable reduction of the longitudinal dimension L of the blocking element  18  be produced during this process as a result of play existing between the blocking parts  24 ,  26 , it can be stipulated that the vehicle door  2  shall not be closed completely during the adjustment, in which in this way, if necessary, a small excess in the longitudinal dimension of the blocking element compared with that of the intervening space can also be produced, so as to achieve an absolutely play- or gap-free bridging of the intervening space  14  with the door closed completely. The separator film or separator strip  40  is then removed, in order to obtain a minimum gap of approximately 1 to 2 mm (according to requirement) which prevents damage to paintwork and a build-up of noise.  
         [0038]     By means of the automatic adjustment of the longitudinal dimension of the blocking element during assembly, a significant time saving will be achieved, as this circumvents a costly measurement and adjustment process in production.  
         [0039]     As an alternative to the aforementioned embodiment of a blocking element of height H, the fitting of a number of shorter blocking elements could be stipulated, which can be particularly useful if the longitudinal dimension L 1  of the intervening space  14  changes in height. It could also be stipulated that in addition to a blocking element fitted between the door hinges, a supplementary blocking element is to be fitted above the upper door hinge, which can be tenable throughout owing to the assembly according to the invention being labor-saving.  
         [0040]      FIG. 7  shows an adaptation of a blocking element  18  according to the invention, in which the front blocking part  26  facing the A-pillar  4  does not have a plane outer surface, but a ball-shaped outer surface  36 . The reason for this is that the swiveling axis of the vehicle door  2 , about which this is rotated while closing, i.e. during the adjustment process for the blocking element  18 , is relatively close to the blocking element  18 , so that unfavorable relationships of the outer surface  36  can occur, if this is formed parallel to the outer face  34  of the blocking part  24  fastened to the vehicle door  2 , as this is depicted in FIGS.  2  to  6 . The ball-shaped, outward-facing convex form of the outer surface  36  in accordance with  FIG. 7  thus represents a compromise between good adjustability and large surfaces available against the A-pillar  4 .  
         [0041]      FIG. 8  shows, in a view corresponding to that in  FIG. 7 , another version of the blocking element  18  according to the invention, in which, differently from the embodiments described earlier, not a straight line but a rotating movement of both blocking parts is stipulated. A first blocking part  24  is connected, in a way which is not depicted in detail, for example by means of screws or by welding, with the front face  10  of the vehicle door  2 , while a second blocking part  26  is connected via a hinged axis  44  (at right angles to the plane of the illustration) which can be swiveled with the first blocking part  24 . By means of a clockwise swiveling movement, the outer surface  36  of the second hinged element  26  can clearly be moved closer to the door  2  or the outer surface  34  of the first blocking part  24  and the aforementioned longitudinal dimension L of the blocking element  18  reduced accordingly, whereas a swiveling movement anticlockwise enlarges the longitudinal dimension L.  
         [0042]     The second blocking part  26  has a fixing joint  46 , which is provided with an inner surface in the form of a cylindrical jacket  48 , in which the axis of the cylinder coincides with the axis of the hinge  44 .  
         [0043]     A locking wedge  50  is introduced movably by means of a guiding strip  52  with a T-shaped cross-section into a corresponding guide groove  54  of the first blocking part  24  in a vertical direction (at right angles to the direction of travel), having an outer surface  56  extending upwards in the form of a cone so that, by introducing the locking wedge in a vertical direction downwards from above, a clamping and locking effect between outer surface  56  and inner surface  48  and thus between second blocking part, locking wedge and first blocking part is achievable.  
         [0044]     Advantageously, safety screws  58 , the longitudinal axis of which runs tangentially to the hinge axis  44  and which can be moved against a securing surface  60  of the locking wedge  50  running tangentially to the hinge axis  44 , are provided in the second blocking part  26 .  
         [0045]     A spring element, which is not illustrated, can also be provided, in order to press the blocking parts  24 ,  26  apart in the direction of maximum longitudinal dimension, i.e. in order to pre-stress the second blocking part  26  in  FIG. 8  anticlockwise relative to the first blocking part  24 .  
         [0046]     For assembly of the blocking element  18  depicted in  FIG. 8 , the vehicle door  2  is closed with the blocking element  18  present in the attached, pre-fitted and initial state, in which there can also be in this case a separator film on the outer surface  36  of the second blocking element  26 . The locking wedge  50  can then be placed in the guide groove  54  and driven in from above to such a distance that a firm blocking effect is achieved between both blocking parts. The securing screws  58 , which were slackened in the initial state, are rotated and brought into contact with the safety surface  60 , so that there is an additional security against unwanted backward movement of the blocking part  26  in the event of a crash.