Abstract:
The present disclosure relates to a front structure of a vehicle body having a wheel installation strut and a side member which flanks an interior defined by the front car. The side member has a convex surface, by means of which it is fastened to an end of the wheel installation strut in multiple points. At least one point is offset relative to the other points towards the interior. As a result, a front structure with good stiffness for improved occupant protection can be provided, which can also be assembled in a simple manner.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to German Patent Application No. 102013014209.1 filed Aug. 26, 2013, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The technical field relates to a front structure of a vehicle body. 
     BACKGROUND 
     The German disclosure publication DE 10 2009 042 064 A1 shows a body front structure with a wheel installation strut and a side member connected thereto. A flat welding flange forms an interface between side member and wheel installations strut. The front frame and the wheel installation strut abut one another in the region of the welding flange and are welded to one another in a plane. If, during an accident, the front car is deformed and side member and wheel installation strut are twisted against one another in the process, the welded connection is substantially subjected to tensile loading perpendicularly to the surfaces of side member and wheel installation strut touching one another. 
     SUMMARY 
     In accordance with the present disclosure a front body structure is provided which is improved with respect to occupant protection and stability, and which can preferably also be produced in a simple manner. 
     According to a configuration of the present disclosure, a front car of a vehicle body with a wheel installation strut and a side member is provided, which flanks an interior of the front car. An end of the wheel installation strut is fastened at multiple points of a surface of the side member, the surface normals of which deviate from one another. Thus, all welding spots are never purely subjected to tensile loading simultaneously, and at least one of the welding spots is also subjected to shearing. While the tensile forces which are perpendicular to the surfaces of wheel installation strut and side member touching one another also deform the surfaces but can then concentrate on and destroy small regions of a welded connection. The surfaces are hardly deformed by the shearing forces which are parallel to these, and the loading is approximately evenly distributed over the entire extent of the welded connection so that the probability that the connection should fail is low. 
     The surface of the side member can be convex in order to accommodate the points with the surface normals deviating from one another in confined space. Offsetting at least one of the points with respect to the other one towards the interior can contribute to the stiffness of the connection of the side member to the wheel installation strut. The angles defined by the various surface normals should reach at least 90°, so that a force which subjects one of the points purely to tensile loading produces a shearing load on at least one other point. Angles of up to 180° can be practical. Preferably, the fastening in the points is a materially-joined connection, in particular a welded connection or a bonded connection. Optionally, multiple fastening types can be combined with one another. 
     According to an advantageous embodiment, at least one of the points is arranged on a top or bottom side of the side member. Because of this, torsional or bending forces can be better transmitted and the fastening points can be loaded in different directions of force application. 
     According to an advantageous embodiment, at least one of the points (in the mounted state of the side member) is arranged on an at least approximately horizontally oriented face of the side member. Preferably, the horizontal face forms a part of the top or bottom side. On the horizontal face, forces can be transmitted over a large area between the side member and the wheel installation strut. The fastening points can be parts of an extended connection, in particular welded or bonded connections. 
     According to an advantageous embodiment, the wheel installation strut includes an elongated hollow body and a structural component with a flange. 
     The previously mentioned object is also solved by a front car of a vehicle body which is embodied with a wheel installation strut and a side member. The wheel installation strut includes a structural component and an elongated hollow body. The structural component is plug-connected to the elongated hollow body and includes a flange, which is fastened to a convex surface of the side member. The sub-division into hollow body and structural component allows solely producing the structural component, in particular its flange, with a close tolerance so that it can enter into a fixed connection with the points of the side member. The hollow body can be cost-effectively produced with further tolerance. 
     According to an advantageous embodiment, the flange includes flange portions with surfaces facing one another. This makes possible a pincer-like engaging about the side member. Because of this, the fastening points can be arranged at a greater distance from one another on the outside of the side member, which supplies good stability and their surface normals can define a large angle, near 180°. 
     At least two of the flange portions can be formed through surfaces which are at least approximately oriented parallel to one another. Because of this, fastening to a top or bottom side, in particular to a horizontal face of the side member can take place in a simple manner. The flange portions can be formed as two straps located opposite one another, which in each case protrude in the direction of the longitudinal axis or in the direction of the side member and are connected to a top and/or bottom side of the side member in the at least one point. The flange preferably includes multiple facets, which are oriented at an angle to one another. Because of this, the stability of the structural component can be increased, in particular also with respect to a force acting in transverse direction (perpendicular to the driving direction), which can then be transmitted from the facets as tensile or compressive force. 
     The connection between hollow body and structural component can be established through a pin of the structural component, which is inserted into the hollow body. The pin can be formed hollow, in particular cup-like, typically with a bottom and a circumferential wall. This allows an economical production of the structural component, in particular by deep-drawing from a flat material cutting. 
     According to an advantageous embodiment, an opening is formed in the bottom. By creating the opening prior to the deep-drawing and widening it during the deep-drawing, a reduction of the wall thickness of the circumferential wall during the deep-drawing can be minimized, which benefits the load capacity, in particular the torsional strength of the structural component. The opening should not take up the entire extent of the bottom; a bottom region which annularly extends about the opening improves the stability of the structural component. 
     The pin can be tapered in order to facilitate a provisional fastening in the hollow body through clamping/wedging. The pin can have a non-round cross section in order to be able to engage in the hollow body in a torsionally fixed manner. A rectangular or trapezoidal cross-sectional shape is particularly suitable in order to fill out the free cross section of a hollow body produced in a manner that is known for conventional wheel installation struts by welding two deep-drawn sheets together along their longitudinal edges. 
     The side member can be a hydroformed part. Hydroforming makes possible producing a side member with a cross section that is variable over its length from a one-piece hollow profile portion. Because of this, the welded flanges which project at the top and bottom and which are usual with side members constructed in two parts are obsolete because of this, which render fastening the flange of the structural component more difficult or limit its extent. 
     According to an advantageous embodiment, the side member carries an anchor plate at an end. An inner hollow space of the side member is accessible through a passage of the anchor plate. Because of this, a tool, preferably a welding tool can connect both the side member to the wheel installation strut and also the anchor plate to the side member in a method step. 
     A method for assembling the front car may include the following: a) providing a hollow body; b) providing a structural component; and c) connecting the structural component to the hollow body to form a wheel installation strut. Preferably, connecting the structural component to the hollow body takes place by inserting or plugging the structural component into the hollow body, in particular a pin of the structural component is brought to lie against a corresponding inner surface area of the hollow body. Here, a reinforced end of the wheel installation strut can be formed by fastening the pin to the hollow body. 
     Preferably, a materially-joined connecting of the pin to the inner surface area, for example bonding, preferably welding, in particular spot welding in circumferentially arranged welding spots takes place following the insertion. 
     The method further includes providing a side member and fastening the structural component to the side member in multiple fastening points which are offset relative to one another and relative to an interior of the front car can take place. Preferably, connecting is effected through material joining, in particular through a joining method, e.g. by welding. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements. 
         FIG. 1 a    shows a schematic perspective view of a front car of a vehicle body; 
         FIG. 1 b    shows a schematic perspective view of a part region of the front car shown in  FIG. 1   a;    
         FIG. 1 c    shows a schematic perspective view of a part of a wheel installation strut, which forms a part of the front part shown in  FIG. 1   a;    
         FIG. 2  shows a schematic perspective view of a part region of the front car shown in  FIG. 1 a    with a structural component mounted on a wheel installation strut of the front car according to an exemplary embodiment of the present disclosure; 
         FIG. 3  shows a schematic perspective detail view of the structural component shown in  FIG. 2 ; 
         FIG. 4  shows a schematic perspective view of a part of the front car shown in FIG. la, wherein a structural component each according to an exemplary embodiment of the present disclosure is mounted between a wheel installation strut and a side member of the front car; 
         FIG. 5  shows a schematic sectional view according to the section A-A indicated in  FIG. 2  through a wheel installation strut and a structural component according to an exemplary embodiment of the present disclosure; 
         FIG. 6 a    shows a schematic sectional view according to the section B-B indicated in  FIG. 5 , with an assembly tool in a first position; 
         FIG. 6 b    shows the sectional view according to  FIG. 6A  with the assembly tool in a second position; 
         FIG. 6 c    shows a schematic sectional view according to the section C-C indicated in  FIG. 4 , with the assembly tool in a third position; and 
         FIG. 6 d    shows a schematic sectional view according to the section B-B indicated in  FIG. 5  with the assembly tool in a fourth position. 
     
    
    
     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 a    shows a front car  1  of a vehicle body, which includes a right side member  2   a  and a left side member  2   b  in travelling direction F. The front car  1  defines or delimits an interior I, in which for example an engine can be arranged. The side members  2   a ,  2   b  are each connected to a wheel installation strut  3   a ,  3   b . A lock cross member  4  is arranged together with a bumper cross member  5  in a bow region of the front car  1  and connects the two side members  2   a ,  2   b . A front wall  7  forms a boundary of the front car  1  in travelling direction F. The side members  2   a ,  2   b  or wheel installation struts  3   a ,  3   b  are each assembled with an inner sill structure  6   a ,  6   b  and a side member extensions  2   a . 1 ,  2   b . 1  respectively. The side members  2   a ,  2   b  of the front car  1  are oriented along a central longitudinal axis M, which extends in the travelling direction F (against an x-direction of the shown coordinate system). The wheel installation struts  3   a ,  3   b  are arranged at the interface to the respective side member  2   a ,  2   b  approximately perpendicularly to the central longitudinal axis M running in the y-direction of the shown coordinate system (at an angle of 75°-90°). 
       FIG. 1 b    shows an inner strut  3 . 1  of the wheel installation strut shown in  FIG. 1 a   . The inner strut  3 . 1  is connected to a spring strut mounting  8 . Furthermore, a lateral front wall  9 . 1  and a lateral windshield mounting  9 . 2  are shown, each of which form part of the front car shown in  FIG. 1 a   .  FIG. 1 c    shows an outer strut  3 . 2  which is provided in order to be joined to the inner strut  3 . 1  on the outside and with it form a hollow body of the wheel installation strut. 
       FIG. 2  shows the components shown in  FIG. 1 b    and the outer strut  3 . 2  shown in  FIG. 1 c   , which is mounted to the inner strut  3 . 1  on the outside and with it forms the hollow body designated  3   e  here. A structural component  10  engages into an open front end of the hollow body  3   e . The structural component  10  can be optionally arranged initially on the inner strut  3 . 1  before the outer strut  3 . 2  is arranged on the inner strut  3 . 1 , or initially on the outer strut  3 . 2 , before the outer strut  3 . 2  is arranged on the inner strut  3 . 1 . The outer strut  3 . 2  can also be arranged on the inner strut  3 . 1  in order to subsequently introduce the structural component  10  between the two struts  3 . 1 ,  3 . 2 . Preferably, the struts  3 . 1 ,  3 . 2  are initially connected to one another in order to subsequently connect the structural component  10  to at least one of the struts  3 . 1 ,  3 . 2 , preferably to both. 
       FIG. 3  shows the structural component  10  in detail, in particular in an arrangement with respect to the travelling direction F, in which it can be connected to a wheel installation strut (not shown). The geometry of the structural component  10  can be described as a cup or hat shape, which is substantially formed by a pin  13 , in particular a circumferential wall and a flange  12 . The pin  13  forms a hat crown of the hat shape and the flange  12  forms a brim of the hat shape. 
     The pin  13  is subdivided into four wall portions  13 . 1 ,  13 . 2 ,  13 . 3 ,  13 . 4  and the flange  12  is subdivided into four flange portions  12 . 1 ,  12 . 2 ,  12 . 3 ,  12 . 4 . The individual portions merge into one another, wherein the structural component  10  is embodied as a deep-drawn part. The pin  13  is delimited by a bottom or hat lid  11 , in which an opening  11   a  is formed. The wall of the pin  13  is circumferentially formed about the longitudinal axis Y, which in the installed state of the structural component  10  extends transversely to the travelling direction F in the y-direction of the shown coordinate system. 
     Here, the flange  12  is arranged at three different angles γ 1 , γ 2 , γ 3  to a z-direction or an xz-plane. A first flange portion  12 . 1  or third flange portion  12 . 3  is arranged at an angle γ 1  to the xz-plane, a second flange portion  12 . 2  or fourth flange portion  12 . 4  at an angle γ 2 , and a protruding strap  12   a  (each at an angle γ 3 ). Here, two straps  12   a  located opposite one another are provided. The protruding straps  12   a  are arranged at least approximately parallel to the Y-longitudinal axis and extend in x-direction along the entire lateral length of the structural component  10 . Because of this, fastening points P 2  can be provided in an x-direction over a large length portion, in particular welding spots, as a result of which the connection is made stronger, in particular also with respect to torsion. The fastening points P 2  in this case are arranged in locations in which the structural component  10  has a surface normal n 2 . The exact arrangement of the fastening points P 2  on the respective face is only exemplary indicated here. 
     The brim of the hat of the structural component  10  in this case is formed by a part of the flange  12 , which is arranged between the pin  13  and the protruding straps  12   a . The protruding straps  12   a  project in a direction opposite to the hat crown or the pin  13 , i.e. facing away from the hat crown. Optionally, the protruding straps  12   a  can extend at an angle to the longitudinal axis Y and/or are oriented at least approximately in the same direction as the wall of the pin  13 . 
     The first angle γ 1  here is preferably located in a range from 0 to 25 degrees, more preferably 10 to 15 degrees. The second angle γ 2  is preferably in the range from 25 to 65 degrees, more preferably 35 to 55 degrees, and in particular 45 degrees. The third angle γ 3  is preferably in the range from 65 to 90 degrees, and more preferably 80 to 85 degrees. 
     On the first and third flange portion  12 . 1  and  12 . 3  respectively, fastening points P 0  are indicated, via which the structural component  10  can be connected to a flank of a side member (not shown), in particular in a materially joined manner. The fastening points P 0  are arranged in locations in which the structural component  10  has a surface normal n 0 , which deviates from the surface normal n 2 . The exact arrangement of the fastening points P 0  on the respective face is only exemplarily indicated here. 
     Furthermore, fastening points P 1  are indicated on the fourth flange portion  12 . 4 . The fastening points P 1  are arranged in locations in which the structural component  10  has a surface normal n 1 , which deviates from the surface normal n 0  and n 2  respectively. The exact arrangement of the fastening point P 1  on the respective face is only exemplarily indicated here. 
     On the first and third flange portion  12 . 1 ,  12 . 3  respectively, a bend or a stiffening region  12   b  is provided, by means of which the structural component  10  has greater stability and strength, in particular with respect to forces acting in y-direction. Through the bend, the respective flange portion  12 . 1 ,  12 . 3  can be subdivided into multiple facets corresponding to the geometry of the side member, which make possible an arrangement of fastening points P 0  in different planes. 
     In  FIG. 4 , the side members  2   a ,  2   b  are noticeable, which are each connected by means of the structural component  10  and one of the wheel installation struts  3   a ,  3   b  respectively. The structural components  10  are each arranged in a hollow body  3   e  and the respective side member  2   a ,  2   b  laterally comes to lie against an outer surface area with a bottom side of the flange of the corresponding structural component  10 . An anchor plate  5   a  which includes a passage  5   b  is connected to the side members  2   a ,  2   b.    
       FIG. 5  shows in detail the arrangement of the structural component  10  in the wheel installation strut  3   a ,  3   b . A first, second and fourth wall portion  13 . 1 ,  13 . 2 ,  13 . 4  of the structural component  10  come to lie against an inner surface of the outer strut  3 . 2  of the wheel installation strut  3   a ,  3   b  and a third wall portion  13 . 3  comes to lie against an outer surface of the inner strut  3 . 1  of the wheel installation strut  3   a ,  3   b . The cross-sectional geometry of the hat crown  13  of the structural component  10  is trapezoidal and corresponds to the geometry of the hollow body, which is formed by the two struts  3 . 1 ,  3 . 2 . The structural component  10  merges into the hollow body on all wall portions  13 . 1 ,  13 . 2 ,  13 . 3 ,  13 . 4 . Each wall portion  13 . 1 ,  13 . 2 ,  13 . 3 ,  13 . 4  is connected to the corresponding surface of the wheel installation strut  3   a ,  3   b  in a materially joined manner, preferably each via two welding points or welding spots P 3 . The two braces  3 . 1 ,  3 . 2  are likewise connected to one another via welding spots P 5 . The structural component  10  supplies a double-walled structure, in particular a reinforced end of the wheel installation strut. The second and fourth wall portion  13 . 2 ,  13 . 4  are arranged at an angle a with respect to the x-direction. The first and third wall portion  13 . 1 ,  13 . 3  are arranged in z-direction. The angle a here corresponds at least approximately to the orientation of the portions of the wheel installation strut, on which the welding spots P 5  are provided. Because of this, a direction of force application can be defined between the side member (not shown) and the wheel installation strut. The structural component  10  thus supplies an interface with definable lines of force application. 
     In  FIG. 6 a    it is shown how a welding tool  20  can be arranged in order to connect the structural component  10  to a hollow body of the wheel installation strut  3   a ,  3   b , in order to form a reinforced end of the wheel installation strut  3   a ,  3   b . Two welding electrodes can engage about the wheel installation strut  3   a ,  3   b  and the structural component  10 , specifically the walls  13  of the structural component  10 , and place the welding spots P 3 . The welding electrode which is arranged inside in the structural component  10  in this case is guided up to the structural component  10  on the side of the brim of the hat or the flange  12 . 
       FIG. 6 b    shows a further arrangement of welding electrodes for welding a further wall portion together with the wheel installation strut  3   a ,  3   b.    
       FIG. 6 c    shows a further arrangement of the welding electrodes for welding the flange  12  together with the side members  2   a ,  2   b . Here, the wheel installation strut  3   a ,  3   b  already includes the structural component  10 , which is arranged in a reinforced end or the hollow body  3   e  of the wheel installation strut. One of the welding electrodes or welding tongs is arranged within the side member  2   a ,  2   b . Here, the side member  2   a ,  2   b  can come to lie against a bottom side of the flange  12 . In this way, both the straps  12   a  as well as the flange portions  12 . 2 ,  12 . 4  can be welded together with the side member  2   a ,  2   b . A flank  2 . 2  of the side member  2   a ,  2   b  includes two flank portions  2 . 2   a ,  2 . 2   b , which are arranged at an angle γ 1  to the xz-plane, i.e. to one another at an angle which is twice as large as the angle γ 1 . The angle γ 1  is indicated, for the sake of better clarity, on the opposite side of the flank  2 . 2  but the side member  2   a ,  2   b  need not necessarily be embodied symmetrically. The subdivision of the flank  2 . 2  into two flank portions  2 . 2   a ,  2 . 2   b  arranged at an angle to one another supplies good stiffness of the side member in the transverse direction (y-direction). 
     A flank here is to mean a surface portion of the side member, which is located opposite the hollow body  3   e  and faces a wheel housing. If the side member for example is a profile that is octagonal in cross section with eight individual surface portions, the flank is formed by that surface portion which faces towards the wheel installation strut and is arranged closest to the wheel installation strut. 
     The wall of the pin  13  extends at an assembly angle β to the longitudinal axis Y. The assembly angle β is plotted in  FIG. 6 c    between an axis, which is oriented parallel to the longitudinal axis Y, and an axis or plane arranged in a respective wall portion  13 . 2 ,  13 . 4 . The assembly angle β can optionally also amount 0 degrees, but preferably, depending on the extension of the pin  13  in y-direction, is preferably in the range for example of 1 to 5 degrees. Because of this, plug-connecting up to a predetermined insertion depth can also take place without an additional shoulder or a butt edge being provided for this purpose. 
     The side member  2   a ,  2   b  on the one hand is connected (in each case in a plane which is not shown here) with its flank  2 . 2  assigned to the wheel installation strut to the first and third flange portion of the structural component  10 , in addition to this, however, also to an offset butt face  2 . 3  and an offset upper and lower face  2 . 4 . The offset butt face  2 . 3  is welded together with the second flange portion  12 . 2  and the fourth flange portion  12 . 4 , and the offset upper and lower face  2 . 4  in each case is welded to one of the straps  12   a . Two butt faces  2 . 3  are provided which extend in planes which intersect in the hollow body  3   e . By way of the butt faces  2 . 3 , transverse forces transversely to the longitudinal extension of the side member  2   a ,  2   b  can be absorbed or transmitted. 
     The points P 1 , P 2 , in which welding together takes place, are offset towards the inside in the direction of an engine centrally arranged in the region of the central longitudinal axis of the vehicle body (i.e. with this arrangement of the wheel installation strut this means against the y-direction). One or multiple of the points P 1  arranged on the offset butt face  2 . 3  are offset by a first inner offset y 1 , and one or multiple of the points P 2  arranged on the offset upper or lower face  2 . 4  are offset by a second inner offset y 2 . The points P 1 , P 2  can for example be individual welding spots or part of a weld seam. Preferably, the second inner offset y 2  has an amount which is in the range of half the width (extension in y-direction) of the side member. Because of this, good strength of the connection can be achieved. Optionally, the amount of the second inner offset y 2  is also greater than half of the width of the side member, in particular in order to further increase the stability. 
     In  FIG. 6 d   , it is shown that the flange or the straps  12   a  formed on the flange can be connected to the side member  2   a ,  2   b  via multiple welding spots P 2 , specifically on the offset upper or lower face  2 . 4 . Through the multiple welding spots P 2  which are spaced from one another in x-direction good stiffness or strength can be achieved, in particular also with respect to torsion about the y-axis of the indicated coordinate system. A welding electrode of the welding tool  20  engages through a front opening  2 . 1  of the side member  2   a ,  2   b  in such a manner that the side member  2   a ,  2   b  and the flange  12  of the structural component  10  are arranged between the two welding electrodes of the welding tool  20 . This can also take place if on the side member  2   a ,  2   b  an anchor plate  5   a  is already provided. The anchor plate  5   a  is inserted into the side member  2   a ,  2   b  and has a passage  5   b  and can be fixed on the side member  2   a ,  2   b  by means of the welding electrodes, in particular after the side member  2   a ,  2   b  has been welded together with the structural component  10 . The welding tool  5   b  can be guided through the passage  5   b . Here it is not required to remove the welding tool but the anchor plate  5   a  can be directly welded on after the structural component  10  has been welded on. 
     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 is only an example, 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.