Spacing element for subframe for motor vehicle, subframe and motor vehicle

Abstract

The invention relates to a distance element for a sub-frame of a motor vehicle, a sub-frame and a motor vehicle, and particularly provides a distance element for a sub-frame of a motor vehicle, which is provided with a first channel part and a second channel part which are designed in a uniform cross-section manner, and is provided with a connecting part, and the first channel part and the second channel part are designed in a uniform cross-section manner. The first channel part is connected with the second channel part through the connecting part. The invention further relates to a sub-frame for a motor vehicle, comprising such a distance element. Such a subframe features improved join stiffness for a lateral stabilizer at the front axle.

Description

Technical Field

[0001] The invention relates to a spacer element for a subframe for a motor vehicle, a subframe for a motor vehicle and a motor vehicle. Background Art

[0002] The so-called subframe is a common component in motor vehicle construction. Here, the structural-side articulation points of the wheel suspension are fastened to the subframe, and the powertrain (aggregate) (i.e. engine, transmission and steering gear) is usually also fastened to the front subframe. The subframe can also be called suspension bracket (Fahrschemel) or axle bracket. The subframe is usually composed of a plurality of components, which are combined during the manufacture of the subframe. These components may be, for example, a so-called upper shell and a so-called lower shell, which, in simple terms, each form the upper and lower halves of the subframe. Then a complex hollow profile is obtained by combining them together. In most cases, the upper shell and the lower shell are mainly connected to each other by welding. However, other connecting elements can penetrate the upper shell and the lower shell in order to fix the attachment to the subframe or, however (oderaber, sometimes referred to as or alternatively), fix the subframe to the body-in-white. In order to prevent possible deformation of the subframe caused by this, a plurality of spacing elements or spacing retainers are usually arranged between the upper shell and the lower shell, which ensure that the set shape or the set distance between the upper and lower sides of the subframe is maintained. For this purpose, such spacing elements are designed and dimensioned according to their purpose of use so that the forces acting in the vertical direction in particular can be absorbed by the spacing elements. The spacing elements usually have a sleeve-shaped or tubular shape.

[0003] In practice, high stiffness values ​​for the subframe are generally advantageous. In particular, a large number of different forces often act simultaneously on the front axle (Vorderachse, sometimes called front axle). These are, for example, drive forces, steering forces and forces input by road conditions (e.g. road unevenness). In this case, too low a connection stiffness for the roll stabilizer at the front axle can have a negative impact on the maneuverability of the vehicle in narrow sections of the road (e.g. when driving on a highway construction site) and on the yaw stability in the linear lateral acceleration range ( Sometimes referred to as yaw linearity) has a negative impact. Likewise, low joint stiffness is generally detrimental to the intuitiveness of steering and driving behavior, making driver adaptation to the vehicle behavior difficult. Here, too, the subjective feeling of driving safety and controllability during maneuvers for accident avoidance can be negatively impacted.

[0004] It is known from the prior art to take measures to create different geometries with high rigidity while using them at a low weight. In addition to purely geometric changes, it is also known to provide additional components that are screwed (sometimes referred to as fastened with threaded fasteners) or welded to increase rigidity. This can be, for example, a strut or similar component. It is also known to use components with high sheet thickness, which themselves do not, however, need to meet the operational strength. Therefore, the known options for improving the connection rigidity of the front transverse stabilizer are often characterized by high weight and high material costs.

[0005] Special structural designs of the subframe (e.g. connecting the stabilizer as close as possible to a more rigid structure, for example at a tower of the subframe, or realizing a structure of the longitudinal support that is as rigid as possible in the body-in-white, whereby the rigidity of the connection can be positively influenced by the increased rigidity of the subframe and the longitudinal support) are often structurally complex and also cost-intensive.

[0006] EP 3369645 B1 discloses a subframe for a motor vehicle, which has longitudinal supports extending at a distance from each other, at least one transverse support connecting the longitudinal supports to each other, and a reinforcing element connected to the longitudinal supports and the transverse support and made of sheet metal. The reinforcing element is composed of a first reinforcing element and a second reinforcing element, which are designed as curved shells and have overlapping ends, wherein the overlapping ends are connected to one of the transverse support or the longitudinal support in a materially bonded manner, preferably welded.

[0007] Compared to subframes which are not optimized for rigidity, the solutions known from the prior art are each characterized by a considerable excess weight and / or by increased costs, so that an improved cost-effectiveness ratio would be desirable. Summary of the invention

[0008] It is therefore an object of the present invention to provide a subframe which has increased rigidity, in particular in the region of the connection for the roll stabilizer, and which is structurally simple to produce.

[0009] The object is achieved by a spacer element for a subframe of a motor vehicle, with a first channel part of prismatic design and a second channel part of prismatic design, and with a connecting part, which connects the first channel part to the second channel part. The object is also achieved by a subframe for a motor vehicle with such a spacer element and by a motor vehicle with such a subframe and / or with such a spacer element.

[0010] The first and second distance elements hereby assume the function of known sleeve-shaped spacers. For this purpose, they can have one or more cavities which extend in the axial direction, i.e., usually in the vertical direction, in the installed state. The cavities are open at the bottom and the top of the distance elements respectively and extend in particular through the respective channel parts. The cavities can then be penetrated by threaded fasteners or by bolts. The threaded fasteners or bolts can be provided to fasten the transverse stabilizer to the subframe. The distance elements hereby absorb forces acting in the axial direction and ensure that a predetermined distance, i.e., the extension of the respective distance elements and in particular the respective channel parts in the vertical direction between the first part of the subframe and the second part of the subframe, is not fallen below.

[0011] An object of uniform cross-section is understood here in particular to be an object which has a geometry with two mutually parallel and at least substantially identical end faces and at least one circumferential surface extending perpendicularly to the end faces. The end faces can here, for example, have a generally polygonal shape, such as a quadrilateral, hexagonal or octagonal shape. Likewise, the end faces can, however, be designed as ellipses, eggs or circles. In this preferred embodiment, the uniform cross-section base body is then cylindrical ( Sometimes called a curved cylindrical) base.

[0012] According to a preferred design, it is provided that the first channel part and / or the second channel part is of cylindrical design. Conventional spacers or spacer elements are usually also of cylindrical design. The spacer element according to the invention can then be used without major adaptation (Anpassung, sometimes called adjustment) to the existing structure. In addition, such a cylindrical basic shape provides a favorable ratio of stability and weight of the spacer element.

[0013] Advantageously, it is feasible that the connecting portion has a rectangular basic shape. The connecting portion is preferably a rigid structure, which connects the first channel portion to the second channel portion and can transmit force between the first channel portion and the second channel portion. When the connecting portion has a rectangular basic shape, the length of the first edge (Kante, sometimes referred to as an edge) of the rectangular basic shape can basically or just correspond to the height of the channel portion. The length of the second edge of the rectangular basic shape can basically or just correspond to the spacing between the first channel portion and the second channel portion, especially the spacing in the horizontal direction. In particular, the length of the second edge can correspond to the spacing of the periphery of the first channel portion and the second channel portion. The corresponding spacing can correspond to the minimum possible spacing between the first channel portion and the second channel portion. But it is also feasible that the spacing is greater than the minimum possible spacing. In particular, in a preferred design, the length of the edge of the rectangular basic shape of the connecting element corresponds to the spacing between the center axis of the first channel portion and the center axis of the second channel portion. In this case, it is feasible that the connecting portion extends tangentially to the periphery of the first channel portion and the periphery of the second channel portion, respectively.

[0014] The connecting part can be designed as an at least substantially flat sheet metal part. It is then particularly possible to design the distance element in one piece. In other words, a single metal sheet is then used to produce the entire distance element or at least the base element of the distance element, which comprises the first channel part, the second channel part and the connecting part.

[0015] According to a preferred embodiment, the distance element has a first wound sheet metal section, which forms the first channel portion, and / or a second wound sheet metal section, which forms the second channel portion. The distance element can then be manufactured simply and cost-effectively and at the same time has a rigid and strong connection between the first channel portion and the second channel portion. A wound sheet metal section is understood here in particular to be a sheet metal section that is deformed from a flat shape into a curved shape. The bending radius can be significantly smaller than the length of the sheet metal and, for example, be less than 40%, less than 30% or less than 20% of the length of the sheet metal. The bending radius is preferably constant here, but can also be variable, so that a curved cross section that differs from a part-circular cross section is then obtained. The curved section can have, for example, a midpoint angle (Mittelpunktwinkel, sometimes referred to as the center angle) of between 180° and 360°, preferably between 270° and 260° and particularly preferably between 300° and 350°. It is also conceivable in principle to spirally roll up such a sheet metal section, whereby a midpoint angle of greater than 360° is similarly obtained.

[0016] According to an advantageous embodiment, the connecting part has a recess. The recess can be arranged in particular at an edge of the connecting part, for example at the lower edge, and can be open towards the edge. In other words, the connecting part can have a region with a reduced extension in the vertical direction. This design prevents components of the subframe or the motor vehicle extending between the first channel part and the second channel part from coming into contact with the spacing element or being interfered with by it. In particular, the free space created by the recess can be filled or penetrated by a transverse stabilizer part of the motor vehicle.

[0017] A suitable embodiment provides that the first center axis of the first channel part and the second center axis of the second channel part are oriented parallel to one another. In a special embodiment, the distance element can also be designed at least approximately mirror-symmetrically with respect to an axis of symmetry extending through the connecting part. Accordingly, in particular the first channel part can be designed in the same way as the second channel part. This is especially the case, but not only, when such an axis of symmetry exists.

[0018] Advantageously, it is feasible that the connecting portion is parallel to the first center axis of the first channel portion and / or parallel to the second center axis of the second channel portion. The connecting portion can be designed in a planar manner. Accordingly, the first side surface and the second side surface of the connecting portion can be designed flat. When the connecting portion is designed as a plate element, the upper edge and the lower edge of the connecting portion can extend substantially or precisely horizontally. Accordingly, the third edge and the fourth edge of the connecting portion can extend vertically. The third edge can be connected to the first channel portion and / or the fourth edge can be connected to the second channel portion. It is feasible that the third edge and / or the fourth edge exist only as an imaginary limit of the connecting portion in a geometric sense. In particular, when the spacing element is designed in one piece, the connecting portion can seamlessly transition into the first channel element and / or the second channel element without constructing a physical edge. In other words, it is feasible that the peripheral surface of the first channel portion and / or the peripheral surface of the second channel portion continuously transition into the side of the connecting portion. It is feasible to take measures to improve the rigidity of the connecting portion and / or to reduce the weight of the connecting portion. Thus, the connecting part can have, for example, weight-reducing recesses and / or reinforcing ribs or beads for reinforcement.

[0019] It is possible that the first center axis of the first channel part and the second center axis of the second channel part extend outside the plane determined by the planar section of the connecting part. In the top view, the spacing element may have an opera goblet-shaped shape. In this case, the connecting part may extend along the tangent of the circumference of the first channel part and / or the second channel part. When the connecting part extends simultaneously parallel to the connecting line between the center axis of the first channel part and the center axis of the second channel part, the opera goblet-shaped design described above is obtained. It is also possible that the connecting part does not extend parallel to the connecting line between the center axis of the first channel part and the center axis of the second channel part. Then the connecting part may intersect with the connecting line. In this case, an S-shaped cross section of the spacing element is obtained in the case of sectioning parallel to the horizontal plane. When the channel part consists of a wound sheet section, the deformation directions of the two end sections are opposite in this case. Then one section is bent or wound toward the front side of the sheet, and the other section is bent or wound toward the back side of the sheet.

[0020] It is possible that the first channel section and / or the second channel section and / or the connecting section consists of a metal sheet or a section of a metal sheet with a thickness of 1 mm to 5 mm, preferably 2 mm to 3 mm. This results in a favorable ratio of rigidity, strength and weight. The connecting section can have a smaller material thickness than the channel section. Such a design has a weight advantage over a design with a constant material thickness. In an alternative design, it is also possible that the connecting section has a greater material thickness than the channel section.

[0021] A preferred embodiment provides that the spacing element is fastened to a part of the subframe by means of a welded connection. The welded connection can consist of a weld, a spot welded connection, or of a plurality of spot welded connections or welds. The welded connection can connect the horizontally extending side or edge of the spacing element and in particular the connecting portion to the subframe and in particular the surface of an element of the subframe. The welded connection can preferably extend horizontally. Accordingly, the surface of the element of the subframe to which the connecting portion is connected also usually extends horizontally. The welded connection can be designed as a weld with different lengths. For example, the length of the weld can be greater than 50% of the length of the connecting section and / or less than 85% of the length of the connecting section. It is also feasible that the length of the weld is greater than 85% of the length of the connecting section and in particular 100% of the length of the connecting section.

[0022] As already indicated above, it is possible to arrange the distance element in the region of the subframe in which the transverse stabilizer of the motor vehicle extends when the subframe is installed in the motor vehicle. It is possible here that the first channel section and the second channel section are arranged on mutually opposite sides of the channel region for the transverse stabilizer, as viewed in the direction of travel. It is also possible here that an imaginary connecting line between the first channel element and the second channel element extends parallel to the direction of travel. For example, the imaginary connecting line can be oriented horizontally and connect the center axis of the first channel element and the center axis of the second channel element to each other.

[0023] Different measures can be taken to achieve weight saving. For example, the channel part and / or the connecting part can have a notch or a hole-shaped recess, such as a channel aperture. Not only the channel part but also the connecting part can have such a notch or multiple notches, such as at least 2, at least 3 or at least 5 notches respectively. The notch can be designed, for example, in a circular or oblong shape. When a channel part or two channel parts have a notch in the form of an oblong hole or a slit, the notch mentioned preferably extends parallel to the central axis of the channel part, which usually corresponds to a vertical line. Multiple oblong holes or slits can exist distributed on the periphery of the respective channel parts. A channel part or two channel parts can have one or more lines extending horizontally along the periphery of the respective channel parts, respectively, and the lines are respectively provided with multiple notches spaced apart from each other. In this case, the notch can also be designed, for example, in a circular shape.

[0024] The connecting part can also have such a row or such horizontally extending rows of, for example, circular recesses. Alternatively or additionally, the connecting part can have horizontally extending slots or horizontally extending slots. In order to increase the rigidity of the connecting part in particular, a beading or embossing of the connecting part can be provided. The beading or embossing can preferably be oriented horizontally. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Embodiments of the present invention are explained in more detail with reference to the accompanying drawings and the following description.

[0026] Figure 1 A first embodiment of a subframe is shown in a perspective view,

[0027] Figure 2 shows a part of a subframe according to the prior art,

[0028] Figure 3 A detail of a first exemplary embodiment of a subframe 2 with a distance element according to the invention is shown in a perspective view.

[0029] Figure 4 A portion of a first embodiment is shown in a perspective view,

[0030] Figure 5 A portion of the first embodiment is shown in perspective view, and

[0031] Figure 6 A perspective view of the first embodiment as viewed obliquely from below is shown. DETAILED DESCRIPTION

[0032] Figure 1 A first embodiment of a subframe 2 is shown in a perspective view with two distance elements according to the invention which are not visible in the presented view. The subframe 2 consists of three main components in total, namely an upper shell 4, a lower shell 6 and a body 8. The three main components mentioned are respectively three-dimensionally formed metal parts which are connected to one another and together with further three-dimensionally formed sheet metal parts (such as, for example, a tower shell, a transverse support, etc.) form the subframe 2. In addition, in Figure 1 1 shows a transverse stabilizer 10 which is connected to the subframe 2. This connection is usually achieved by means of a clamp which is not visible in the illustration shown. The area drawn in dashed lines corresponds approximately to the detail shown in the subsequent figures.

[0033] Figure 2 A section of a subframe 2 according to the prior art is shown. The subframe also consists of an upper shell 4 and a lower shell 6. For the sake of clarity, the upper shell 4 and the lower shell 6 are not fully presented so that details can be seen, which are otherwise covered by the side walls of the upper shell 4 or the lower shell 6, for example. The upper shell 4 and the lower shell 6 are connected to each other at multiple locations by threaded fasteners, which are used to fix other components to the subframe 2 or to fasten the subframe 2 to the body-in-white of the motor vehicle. For this purpose, in the example presented, two threaded fasteners are screwed from below through the lower shell 6 into nuts arranged at the upper shell 4. Two spacing elements 12 ensure that the two components to be connected do not fall below the set distance and do not cause deformation of the upper shell 4 and / or the lower shell 6. The spacing elements 12 are designed as sleeves or as tube sections. They are made of metal and have a cylinder-shaped or hollow cylinder-shaped basic shape.

[0034] Figure 3 A section of a first embodiment of a subframe 2 with a spacing element 14 according to the invention is shown. The subframe 2 consists of at least an upper shell 4 and a lower shell 6 in a known manner. The upper shell 4 and the lower shell 6 are traversed in the section shown by two threaded fasteners which are not visible in the figure. The two threaded fasteners penetrate the spacing element 14 here. The spacing element 14 has a first cylindrical channel part 16 and a second cylindrical channel part 18 and a connecting part 20. The first end faces of the first channel part 16 and the second channel part 18 are in contact with the surface of the lower shell 6, respectively. On the opposite side, the second end faces of the first connecting part 16 and the second connecting part 18 are in contact with the surface of the upper shell 4, which is not shown in the figure. Not only the upper shell 4 but also the lower shell 6 have passage holes for the threaded fasteners at the subordinate points. There are two nuts on the surface of the upper shell 4 opposite to the spacing element 14, into which the threaded fasteners are screwed. In addition, a welded connection 22 is shown, which is implemented as a weld seam and connects the spacing element 14 to a part of the subframe 2. In the embodiment presented, the portion to which the distance element 14 is connected is the underside of the upper shell 4. The weld connection 22 thus connects the upper edge of the connecting portion 20 to the underside of the upper shell 4.

[0035] Figure 4 Similar to Figure 3 The view of FIG. 1 shows a first embodiment, wherein only the upper shell 4 and the transverse stabilizer 10 are shown in this view. It can be seen that the area in which the spacing elements not visible in this view are arranged is the box-shaped section 24 of the upper shell 4. Two nuts 28 can be seen on the upper side of the upper shell 4, into which threaded fasteners are screwed for connecting the upper shell 4 to the lower shell 6 (not shown) and for mounting the transverse stabilizer 10. It can also be seen that the upper shell 4 has a free space 26 in the area of ​​the transverse stabilizer 10, through which the transverse support 10 extends. The free space 26 is realized in particular by a partially circular, approximately semicircular recess in the side wall of the box-shaped section 24. The free space 26 between the transverse stabilizer 10 and the upper shell 4 is filled by the geometry of the rubber mounting for supporting the transverse stabilizer 10. A clamp (not shown in the figure) extends around this rubber geometry, which is used to fix the transverse stabilizer 10 on the subframe 2. The connecting part of the distance element, which is not visible in the figure, has a similar recess through which the transverse stabilizer 10 can extend. The recess in the connecting part can have a shape similar to the recess in the side wall in the upper shell 4 or exactly the same.

[0036] Figure 5 It also shows the Figure 4. However, in this view, the upper shell 4 is only partially visible, so that the distance element 14 is visible. The distance element 14 is placed on the upper side of the lower shell 6 at its lower side, in particular with the lower end sides of the first channel section 16 and the second channel section 18. At the upper side or upper edge of the connecting section 20, the connecting section 20 is also in contact with the upper shell 4. A welding area 30 is formed in this area, in which a welded connection to a part of the subframe, in this case therefore to the upper shell 4, is arranged in the assembled state. The connecting section 20 of the distance element 14 has an arc-shaped edge 32 at its downwardly pointing end side, which makes it possible to provide the previously described free space for the transverse stabilizer 10 and its support. It can also be seen that the two channel sections 16, 18 are composed of bent sections of a sheet metal, which forms the distance element 14 and is brought from a flat shape to the shape of the distance element 14 by partially rolling up the end sections. The flat initial shape of the sheet metal corresponds here to a rectangle with a relatively large length-to-width ratio. In other words, the length of the long side of the rectangle is therefore a multiple of the length of the short side of the rectangle. The short side of the rectangle corresponds to the height of the distance element 14 in the installed state. In contrast to the rectangle, the sheet metal has partially circular sections in its initial shape, which form free spaces with curved edges 32 in the deformed state.

[0037] Figure 6 1 shows a perspective view of the embodiment of the subframe 2 with the spacing element 14 described above, viewed obliquely from below. In the presented view, only the upper shell 4 is presented, but the lower shell 6 is not presented. In addition, the upper shell 4 and the spacing element 14 are together relative to each other. Figure 4 and 5 The view in FIG. 4 is rotated 90°. In addition to the upper shell 4, the spacing element 14 can be seen, which is composed of a first channel portion 16, a second channel portion 18 and a connecting portion 20. The connecting portion 20 has a bonding Figure 5 The arcuate edge 32 already described. The welded connection 22 connecting the connection part 20 to the surface of the upper shell 4 can also be seen. The first channel part 16 has a central cavity 34, through which the threaded fastening part, which is not shown, extends. Similarly, the second channel part 18 has a central cavity 36, through which the threaded fastening, which is also not shown, extends. It can also be seen that although the channel parts 16, 18 basically have a hollow cylinder-shaped basic shape, they are not completely closed at the circumference. The channel parts 16, 18 therefore each have a gap 38, 40 or a slit extending in the vertical direction, which forms a free space between the respective end faces of the respective end sections of the sheet metal parts (the channel parts 16, 18 are formed by the respective end sections) and the respective transition areas between the first channel part 16 or the second channel part 18 and the connection part 20.

[0038] All features of different embodiments that are not mutually exclusive in terms of logical thinking can of course be combined with one another. In the embodiments, a preferred example of a cylinder-shaped design of the matrix of the channel portion is described. Other equal-section basic shapes, such as square ( Sometimes referred to as a rectangular parallelepiped) base body, but it is also easy to imagine and offers the same advantages as a cylinder-shaped base body in terms of strength and rigidity. Other modifications are also conceivable. Thus, for example, the spacing element 14 can be relative to the Figure 5 The embodiment presented in FIG. 1 is installed in the subframe 2 in a manner rotated by 180°. In other words, then relative to Figure 5 , the upper and lower edges of the distance element 14 are interchanged. The curved edge can then point toward the upper shell of the subframe 2. The welding region 30 can then be oriented downward toward the lower shell 6 in this embodiment. The horizontally extending edge of the distance element 14 can then contact the upper side of the lower shell 6. If this edge has the welding region 30, a material-fitting connection, for example a welded connection, can occur between the distance element 14 and the lower shell. The distance element 14 can thus be welded to the subframe 2 and in particular to the lower shell 6 with the welding region 30.

[0039] Reference Numbers List

[0040] 2 sub-frames

[0041] 4 Upper shell

[0042] 6 Lower shell

[0043] 8 Main Body

[0044] 10. Lateral stabilizer

[0045] 12 Pitch Elements

[0046] 14 pitch elements

[0047] 16 First channel section

[0048] 18 Second channel section

[0049] 20Connection

[0050] 22 Welding connection

[0051] 24 box sections

[0052] 26 Free space for lateral stabilizer

[0053] 28 Nut

[0054] 30 welding area

[0055] 32 curved edges

[0056] 34 Cavity

[0057] 36 Cavity

[0058] 38 Gap

[0059] 40 Clearance

Claims

1. A spacing element (14) for a subframe (2) of a motor vehicle, comprising a first channel portion (16) of uniform cross-section design and a second channel portion (18) of uniform cross-section design, and comprising a connecting portion (20) which connects the first channel portion (16) to the second channel portion (18).

2. The distance element (14) according to claim 1, characterized in that The first channel portion (16) and / or the second channel portion (18) are of cylinder-shaped design.

3. The distance element (14) according to any one of the preceding claims, characterized in that The connecting portion (20) is designed as an at least substantially flat sheet metal portion.

4. The distance element (14) according to any one of the preceding claims, characterized in that The distance element (14) is designed in one piece.

5. A distance element (14) according to any one of the preceding claims, characterized in that A first coiled sheet section forms the first channel portion (16), and a second coiled sheet section forms the second channel portion (18).

6. The distance element (14) according to any one of the preceding claims, characterized in that A first center axis of the first channel portion (16) and a second center axis of the second channel portion (18) extend outside a plane defined by a planar section of the connecting portion (20).

7. A distance element (14) according to any one of the preceding claims, characterized in that The peripheral surface of the first channel portion (16) and / or the peripheral surface of the second channel portion (18) transitions continuously into the side surface of the connecting portion (20).

8. A subframe (2) for a motor vehicle having a distance element (14) according to any one of the preceding claims.

9. The subframe (2) according to claim 8, characterized in that: The distance element (14) is fastened to a portion of the subframe (2) by means of a welded connection (22).

10. A motor vehicle having a distance element (14) according to any one of claims 1 to 7 and / or having a subframe (2) according to any one of claims 8 to 9.

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