Abstract:
A body for a motor vehicle that encompasses a windshield and has an A-column flanking the windshield is provided. The body includes at least one expandable element mounted on the A-column along the edge of the windshield. The body also includes and a cover that covers an installation space of the at least one expandable element and tightly adjoins the windshield.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to German Patent Application No. 10 2011 118 122.2, filed Nov. 10, 2011, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a body with an element that can expand during an accident, so as to dampen the potential impact of a pedestrian on the body. 
     BACKGROUND 
     Known from DE 103 53 447 A1 is to design the A-column of a motor vehicle body as a shell-like longitudinal profile sealed by a movable cover, whose inner cavity incorporates an expandable element. When the latter expands during an accident, the cover is pressed away from the A-column, so as to potentially cushion and decelerate the head of a pedestrian before it reaches the A-column. 
     The A-column of a motor vehicle should itself be as slim as possible so as not to unnecessarily limit the visual field of the driver. This requirement is difficult to satisfy with the conventional structure mentioned above, since space must be provided inside the groove not only for the expandable element, but also for connecting elements that prevent the cover from being flung away by the expansion of the expandable element, and the cover projects over the edges of the groove on both sides. 
     Accordingly, it may be desirable to provide a body of a motor vehicle in which a pedestrian is effectively protected during an impact with the A-column on the one hand, while not unnecessarily enlarging the cross section of the A-column on the other. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background. 
     SUMMARY 
     In one of various exemplary embodiments, a motor vehicle body is provided with an A-column flanking a windshield, at least one expandable element mounted on the A-column along the edge of the windshield and a cover that covers an installation space of the expanding element by having the cover tightly adjoin the windshield. As a consequence, by having the cover simultaneously perform the functions of a sealing profile conventionally mounted along the edge of the windshield, the overall cross section of the A-column can be kept small, minimizing any visual limitation of the driver. In addition, this simplifies assembly and decreases costs by reducing the number of individual parts integrated into the body. 
     The cover is generally anchored to the A-column on an edge facing away from the windshield. Given an expansion of the expandable elements, the edge of the cover facing the windshield can thus be pressed away, and the expandable element can get out into the open through the resultant gap. 
     To let the expandable element through, a principal part of the cover can generally be swiveled around an axis adjacent to the averted edge by expanding the expandable element. 
     To enable the swiveling motion, generally at least regions of the cover can be reversibly deformed. Thanks to the reversibility, the cover can again be placed in its original position at the edge of the windshield after the expandable element has expanded, and need not be replaced at a high cost. 
     If the deformability is elastic too, the cover can at least largely, if not completely, return to its normal position of its own accord after expansion, which also helps to simplify repairs. 
     The edge of the cover facing the windshield on the one hand generally exhibits a sealing lip that abuts against the outside of the windshield, and on the other a retaining lip that abuts against a narrow side or interior side of the windshield and fixes the cover in place in its normal position. 
     On its part, the expandable element generally exhibits a membrane that is reversibly extensible, so that it returns to its normal configuration after expansion is complete and can be reused. The membrane is also generally elastic, so that it can return to its normal configuration without any outside action, which further diminishes repair outlays after an expansion. 
     In one exemplary embodiment, the membrane extends along the A-column like a tube. In another exemplary embodiment, the membrane has a single layer, and has edges tightly secured on the A-column, acting in conjunction with the latter to form a chamber that can be charged with a propellant fluid to expand the expandable element, in one example with a propellant gas from a gas generator. 
     The expandable element and a gas generator for supplying the latter are generally secured on two sides of a support plate of the A-column. 
     This support plate can be a constituent, in one example a one-piece constituent, in the outer wall of the A-column; as an alternative, however, the support plate can be joined with the at least one expandable element and the at least one generator to yield a removable assembly. 
     A person skilled in the art can gather other characteristics and advantages of the disclosure from the following description of exemplary embodiments that refers to the attached drawings, wherein the described exemplary embodiments should not be interpreted in a restrictive sense. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
         FIG. 1  is a view of an exemplary motor vehicle according to various teachings of the present disclosure; 
         FIG. 2  is a schematic cross section through an A-column of the vehicle from  FIG. 1  according to an exemplary embodiment of the present disclosure; 
         FIG. 3  is a cross section analogous to  FIG. 2  according to another exemplary embodiment; 
         FIG. 4  is a cross section analogous to  FIG. 3  according to another exemplary embodiment; 
         FIG. 5  is a cross section analogous to  FIG. 2  according to another exemplary embodiment; and 
         FIG. 6  is a cross section analogous to  FIG. 2  according to another exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or the application and uses of the present disclosure. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. 
       FIG. 1  shows a perspective view of a motor vehicle  1  with a windshield  4  bordered laterally by A-columns  2  and from below by a hood. The A-column  2  on the right hand side as viewed by an observer is depicted in the normal state; a freestanding section  5  of an outer wall of the A-column  2  passes over downwardly into a front fender  6  and upwardly into a roof area  7 . An elastic cover  8  extends between the freestanding section  5  and windshield  4 . Concealed inside the A-column  2  under the cover  8  is an expandable element, e.g., in the form of a rubber hose, which is hooked up to gas generators, in one example pyrotechnic generators, so as to be expanded during an accident. 
     The expandable element here marked  9  is shown in the expanded state on the A-column  2  on the left hand side as viewed by an observer. In the course of its expansion, it has pressed the cover  8  to the side, and now extends substantially cylindrically over the entire length of the A-column  2 , covering the latter. 
     The illustration on  FIG. 1  is not entirely realistic, since a case in which only one of the two expandable elements  9  has expanded is not encountered in practice. Rather, both expandable elements  9  in conjunction with passenger protection systems, which are known in the art and thus not explained in any greater detail here, and actuators for lifting up the hood  3  are coupled to a shared control unit, which simultaneously activates all of these devices upon the detection of an accident. 
       FIG. 2  presents a schematic section through one of the A-columns  2  according to an exemplary embodiment of the present disclosure. The cutting plane substantially extends perpendicular to the longitudinal direction of the A-column  2 . The A-column  2  encompasses several metal sheets welded together along their longitudinal edges, including the in part freestanding outer wall  11  between the windshield  4  and a door portal  10 , an inner wall  12  facing the passenger cabin, along with a support wall  13  that here extends between the walls  11 ,  12 . 
     The freestanding section  5  of the outer wall  11  is here bordered from the front or toward the windshield  4  by a flat step  14 . The latter is adjoined by a support plate  16 , which extends toward the passenger cabin and faces a narrow side  15  of the windshield  4 , and is in turn adjoined by an edge web  17  oriented substantially parallel to the windshield  4 . This edge web  17  is welded with corresponding edge webs of the walls  12 ,  13 , and carries the lateral edge of the windshield  4 . 
     The expandable element  9  is secured to the outside of the support plate  16  facing the windshield  4 .  FIG. 2  depicts this element  9  in cross section in an unexpanded state, and as a dashed outline in an expanded state. Its walls are here tubular, and comprise an elastically extensible material, such as natural rubber or synthetic rubber. In the unexpanded state, it is concealed by the cover  8  so as not to be visible from outside. 
     The cover  8  encompasses an outer edge section  18  anchored to the step  14 , e.g., through adhesive bonding, an arced primary section  19  that bridges the intermediate space between the step  14  and narrow side  15  of the windshield  4 , a highly flexible articulated section  20  between the sections  18 ,  19 , as well as an inner edge section facing the windshield  4  with two lips arranged like a V, a sealing lip  21  that abuts against the outside of the windshield  4 , and a retaining lip  22  that engages the narrow side  15 . The sealing lip  21  is kept elastically tensioned through contact between the retaining lip  22  and narrow side  15 , so that it abuts the windshield so as to form a rainproof seal. 
     If a gas generator  23  that is mounted on the inside of the support plate  16  and communicates with the expandable element  9  is triggered during an accident, the element  9  starts to expand, and in so doing presses from inside against the primary section  19 . This causes the retaining lip  22  to glide off the narrow side  15  of the windshield  4 , and the primary section  19  and lips  21 ,  22  swivel around the hinged section  20  into a position depicted on  FIG. 2  as a dashed outline, in which they clear the way for the expandable element  9  to get out into the open. As a result, the expandable element  9  ultimately forms an expanded pad in front of the A-column  2 , which can cushion and decelerate an impacting body several centimeters in front of the A-column  2 . 
     Once the expandable element  9  has carried out its function, and the gas has once again been drained from its interior, its elasticity causes it to return to the normal configuration shown in cross section on  FIG. 2 . The cover  8  also flips back in the direction of its idle configuration once again, but does not reach it automatically, since the retaining lip  22  hits the outside of the windshield  4  beforehand. By shifting the sealing lip  21  against the elastic resistance of the primary section  19  in the direction of the support plate  16 , the retaining lip  22  can be forced back behind the narrow side  15 , and latch itself in there, so that the original configuration of the cover  8  can also be easily and quickly restored once again. Only the gas generators  23  expended during activation have to be changed out in order to restore the operational capability of the system again. For this purpose, openings  24 ,  25  can be carved into the partition  13  and interior wall  12 , through which access can be gained to the gas generators  23  in the A-columns from the passenger cabin after removing a lid  26  that normally seals the opening  25 . 
     As shown on  FIG. 3 , the support plate  16  can be oriented toward the front instead of face the edge  15  of the windshield  4 , so as to facilitate an expansion of the expandable element  9  against the traveling direction. The shape of the cover  8  is adjusted to the altered orientation of the support plate  16  by having its retaining lip  22  be slightly curved, and engage not just the narrow side  15 , but also the rear side of the windshield  4 . 
     In the exemplary embodiment of  FIG. 4 , the orientation of the support plate  16  again corresponds to the one shown in  FIG. 2 , but as opposed to the exemplary embodiment of  FIG. 2 , the support plate  16  here is not a one-piece constituent of the outer wall  11 ; rather, the outer wall  11  is molded into a back-cut groove  27 , on whose inwardly directed projections  28 ,  29  the elastically flexible support plate  16  is anchored. Following an activation, the support plate  16  along with the expandable element  9  and expended gas generator  23  can be removed from the groove  27 , and reinserted after replacing the gas generator  23 . 
       FIG. 5  shows another modification of the exemplary embodiment of  FIG. 2 , in which the tubular, expandable element  9  is replaced by a simple, one-layer membrane  30 , which is tightly joined along its edges with the support plate  16 . For example, such a tight connection  31  can be an adhesive bond or, if at least the surface of the support plate  16  comprises a material suitable for this purpose, a vulcanized bond. In order to replace the gas generator  23 , openings can be cut out of the walls  12 ,  13 , as described with reference to  FIG. 2 . 
     The exemplary embodiment of  FIG. 6  combines features from the exemplary embodiments of  FIGS. 4 and 5 . As in the case of  FIG. 4 , the outer wall is molded into a back-cut groove  24 , which positively incorporates the elastic support plate  16 . An adhesive or vulcanized bond  31  of the membrane  27  on the support plate  16  can here be confined to the narrow sides of the support plate  16 , on which the membrane  27  is additionally secured by clamping between the support plate  16  and walls of the groove  24 . 
     While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the present disclosure as set forth in the appended claims and their legal equivalents.