Subframe for motor vehicle, spacer element, and motor vehicle

Abstract

The invention relates to a sub-frame for a motor vehicle, comprising an upper component and a lower component and comprising at least one spacer element arranged between the upper component and the lower component, the spacer element having a prismatic base body, characterized in that the spacer element has a flat projection, the flat projection having a flat cross-section, the protruding part is connected with the contact face of the auxiliary frame through at least one welding part. The invention relates to a spacer element for a subframe of a motor vehicle, comprising a prismatic base body, characterized in that the spacer element has a reinforcing projection in order to facilitate the connection of other elements of the subframe, said reinforcing projection protruding from the base body.

Description

Technical Field

[0001] The invention relates to a subframe for a motor vehicle, comprising an upper component and a lower component and comprising at least one spacer element arranged between the upper component and the lower component, wherein the spacer element has a prismatic base body. The invention also relates to a spacer element for a subframe for a motor vehicle, comprising a cylindrical base body, and the invention also relates to a motor vehicle. Background Art

[0002] The so-called subframe is a common component in the structure of a motor vehicle. Here, the structural side hinge point of the wheel suspension is fixed on the subframe, and the front subframe also has various components, namely the engine, the transmission system and the steering transmission system. The subframe can also be called a center frame or axle frame. The subframe usually consists of a plurality of components, which are assembled during the manufacturing process of the subframe. Such components can be, for example, the so-called upper shell and lower shell, in short, the upper shell and the lower shell respectively constitute the upper half and the lower half of the subframe. Then assembled into a complex hollow profile. The upper shell and the lower shell are connected to each other in most cases with material bonding, usually by welding. However, other connecting elements can also penetrate the upper shell and the lower shell to fix the accessories on the subframe or the subframe on the body in white. In order to prevent deformation that may be caused by this, a plurality of spacing elements are usually arranged between the upper shell and the lower shell, and the spacing elements ensure that a predetermined shape or a predetermined spacing between the upper shell and the lower shell of the subframe is observed.

[0003] During driving, the subframe vibrates, which can be disturbing to the vehicle occupants. Therefore, a structure with the highest possible natural frequency is preferred for the subframe in order to avoid acoustic anomalies or defects that are triggered during driving due to a natural frequency of the subframe that is too low.

[0004] From the prior art, it is known to take various measures to provide various geometries with high rigidity at a low weight input. In addition to purely geometric changes, it is also known to provide additional components for increasing rigidity, which are screwed or welded. This can be, for example, a strut or other component.

[0005] Document EP 3 369 645 B1 discloses a subframe for a motor vehicle, which has longitudinal beams extending at a distance from each other, at least one crossbeam connecting the longitudinal beams to each other, and a reinforcing element, which is connected to the longitudinal beam and the crossbeam and is formed from a sheet metal part. The reinforcing element is assembled from a first reinforcing element and a second reinforcing element, which is designed as a bent shell and has overlapping ends, wherein the overlapping ends are connected to the crossbeam or one of the longitudinal beams in a materially bonded manner, preferably welded.

[0006] The solutions known from the prior art are characterized by a considerable increase in weight and / or higher costs compared to subframes which are not optimized for rigidity, so that there is a need to improve the cost-effectiveness ratio. Summary of the invention

[0007] The object of the present invention is therefore to provide a subframe which exhibits advantageous vibration characteristics and which can be produced in a structurally simple manner.

[0008] According to the invention, the technical problem is solved by a subframe of the aforementioned type, wherein the spacing element has a flat projection, which is connected to the contact surface of the subframe by means of at least one weld. In addition, the invention is also solved by a spacing element of the aforementioned type, which comprises a reinforcement projection for connecting to other elements of the subframe, wherein the reinforcement projection projects from the base body, and by a motor vehicle with such a subframe or with such a spacing element. The reinforcement projection can correspond to the aforementioned flat projection. The upper component is generally referred to below as the "upper shell", and the lower component is generally referred to below as the "lower shell".

[0009] By the design method according to the present invention, the reinforcement of the subframe is achieved with lower structural expenditure, and the reinforcement of the subframe in turn achieves a higher natural frequency of the subframe. The acoustic properties of the subframe are thus improved in a simple manner and method. Here, the flat protrusion establishes a physical connection between the spacing element and the contact surface or with a certain structure (a part of which is the contact surface). The structure can be a part of the upper component of the subframe, the lower component of the subframe or other components of the subframe. The spacing element is usually oriented vertically. Accordingly, it can be provided that the contact surface is oriented substantially parallel to the center axis of the prismatic base. The "contact surface is oriented substantially parallel to the center axis" should be understood in particular that the angle between the contact surface and the center axis is less than 20°, preferably less than 10°. In a special embodiment, the center axis of the prismatic base is parallel to the contact surface. In accordance with the purpose, the center axis of the prismatic base can be oriented vertically.

[0010] The term "contact surface" is sometimes used as a figurative description, and it should be understood that the term contact surface can also be used to refer to a component or a part of a component, and does not necessarily refer to a specific surface of the component. In other words, the term "contact surface" also refers to a component whose surface is the contact surface, or refers to a section of the component.

[0011] According to a preferred embodiment, the projection extends in a plane parallel to the center axis of the prismatic base body. It is possible that the projection extends radially or tangentially relative to the circumferential surface of the prismatic base body. The flat projection can establish a connection between the outer circumferential surface of the prismatic base body and the contact surface.

[0012] A prismatic base body is to be understood here in particular as a body whose geometry has two mutually parallel and at least substantially congruent end faces and at least one peripheral surface extending perpendicularly to the end faces. The end faces can, for example, have the shape of a regular polygon, such as a quadrilateral, hexagon or octagon. Likewise, the end faces can also be elliptical, oval or circular. In this preferred embodiment, the prismatic base body is a cylindrical base body.

[0013] In a specific embodiment, it is provided that the projection tapers from the prismatic base body in a trapezoidal manner. In other words, the contact area between the projection and the contact surface, viewed in a direction parallel to the longitudinal axis of the base body, has smaller dimensions than the base body. This allows material and thus weight to be saved, while at the same time substantially maintaining the positive effect on the vibration behavior.

[0014] According to the above features, the welded portion can preferably be a weld extending substantially vertically. As an alternative, of course, multiple spot welds can be provided, or other design methods that meet the purpose can be selected. When the welded portion is a weld, the weld can be a weld extending parallel to the center line of the prismatic substrate.

[0015] According to one embodiment, it is possible that a portion of the projection is passed through a slit arranged in the contact surface. In this case, the contact surface can be part of a component of the subframe made of sheet metal. The slit arranged in the contact surface can preferably be adjusted to the cross section or size of the end face of the projection. In other words, the shape of the slit can in principle correspond to the contour of the end face of the projection, but should be designed to be slightly larger, thereby allowing the projection to be introduced smoothly into the slit.

[0016] The welded portion can be arranged on the side of the contact surface facing the base body. In particular, if the subframe is designed so that the section of the projection passes through the slit arranged in the contact surface as described above, the welded portion can also be arranged on the side of the contact surface facing away from the base body. Obviously, in this case, the welded portion can also be arranged on both side surfaces of the contact surface.

[0017] According to a preferred embodiment, the spacer element is constructed in one piece. In particular, the spacer element can be designed as a partially rolled sheet metal. For this purpose, the flat sheet metal can be partially rolled up, so that the rolled section can correspond to a cylindrical base in this case. The unrolled section of the sheet metal then corresponds to a flat protrusion and is thus welded to the contact surface in the end region, for example on the end face. The cross section of the base body can correspond to a circular arc of at least 180°. Preferably, the cross section of the base body corresponds to a circular arc of an angle of 270°-360°, preferably 300°-355°.

[0018] A particularly stable construction is achieved when the bolts or pins connecting the upper subframe component to the lower subframe component extend through the spacing element. The spacing element can absorb forces acting in the axial direction and together with the bolts or pins achieve a stable connection between the upper component and the lower component.

[0019] According to a specific design, it is possible that the projection has an end section which forms an angle of 10° to 60°, preferably 20° to 40° with the main section of the projection. In other words, the projection has a displacement or deformation in the end section, so that the projection has a slight bend 34. Preferably, the projection can be designed in this case so that the lateral surface of the projection is in contact with the contact surface between a section located in the end region of the projection. This makes it possible to achieve an increased contact area between the projection and the contact surface, so that greater stability and correspondingly higher rigidity can be achieved. Depending on the design, the projection can be in contact with the contact surface using the end face or using a section of the lateral face.

[0020] According to an optional improvement of the present invention, the projection has a recess for weight saving. By cleverly designing the recess, for example, designing the recess as an elongated hole that can be oriented in the vertical direction, significant weight saving can be achieved with only a small influence on the rigidity of the component.

[0021] According to another optional design, the projection has a groove. That is to say, the projection can have one or more pits. In this way, the rigidity is further increased. Similar to the weight reduction by means of the hollow, the rigidity-to-weight ratio can also be improved in this way.

[0022] The material thickness of the spacer element in the region of the base body is expediently between 0.5 mm and 10 mm, preferably between 2 and 6 mm, and particularly preferably between 2 mm and 4 mm. In other words, the sheet metal thickness of the sheet metal part forming the spacer element can be between 0.5 mm and 10 mm, preferably between 2 and 6 mm, and particularly preferably between 2 mm and 4 mm.

[0023] It is possible that different material thicknesses or thicknesses, for example sheet metal thicknesses, can be used for different components of the spacer element. It is possible, for example, that the material thickness of the spacer element in the region of the projection is smaller than the material thickness of the spacer element in the region of the base body. In this way, different requirements for different sections of the spacer element are met. In this case, the base body usually has to absorb greater forces in the axial direction, while the projection is designed to reinforce the subframe and can therefore usually be designed to be slightly less rigid. Moreover, weight savings can be achieved in this way. It is also possible that, in the opposite case, the material thickness of the spacer element in the region of the projection is greater than the material thickness of the spacer element in the region of the base body. In this way, the spacer element can be adjusted to the special requirements of the respective purpose of use.

[0024] The reinforcement projection of the spacer element according to the invention can preferably be designed flat, wherein the surface normal of the main surface of the reinforcement projection can be at least approximately perpendicular to the center axis of the base body of the spacer element. Preferably, the base body of the spacer element is designed as a rolled sheet metal section. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Embodiments of the present invention are further explained with reference to the accompanying drawings and the following description. In the accompanying drawings:

[0026] Figure 1 : shows a first embodiment of a subframe according to the present invention,

[0027] Figure 2 : shows a section of a subframe according to a first embodiment of the present invention,

[0028] Figure 3 : A top view showing a section of a subframe according to a first embodiment,

[0029] Figure 4 : Another perspective view showing the region with the spacing element of the first embodiment,

[0030] Figure 5 : shows a partial side view of the second embodiment,

[0031] Figure 6 : A schematic top view showing a portion of a third embodiment of a subframe according to the present invention,

[0032] Figure 7 : shows possible ways of carrying out welding,

[0033] Figure 8 : shows another possible design of the spacer element,

[0034] Fig. 9 : A schematic top view shows a part of a sixth embodiment of a subframe according to the present invention,

[0035] Fig.10 : A partial perspective view showing a seventh embodiment of a subframe according to the present invention,

[0036] Fig.11 : Another stereoscopic view showing the seventh embodiment,

[0037] Fig.12 : A partial perspective view showing an eighth embodiment of a subframe according to the present invention,

[0038] Fig.13 : shows a top view of a ninth embodiment of a subframe according to the present invention, and

[0039] Fig.14 : Another stereoscopic view showing the ninth embodiment. DETAILED DESCRIPTION

[0040] Figure 1 A first embodiment of a subframe 2 according to the invention is shown. The subframe 2 of the embodiment shown consists of three structural basic elements on the main axis, which together form the subframe 2. For orientation, the driving direction F of the vehicle, a part of which may be the subframe 2, is marked. The basic elements, namely the upper shell 4, the lower shell 6 and the main body 8, are composed of three-dimensionally formed metal parts. In the assembled state, the subframe 2 has a plurality of hollow profile-shaped sections, which are designed to enable efficient force transmission, in particular from the wheels suspended on the subframe 2 to the remaining components of the motor vehicle. The upper shell 4 and the lower shell 6 of the subframe 2 are connected to each other at a plurality of locations by bolts, which are used to fix other components to the subframe 2 or to fix the subframe 2 to the body in shell. At some locations, the bolts extend in the vertical direction through the spacer element 12, which is constructed as a relatively simple metal sleeve. However, according to the invention, at least one spacer element 10 is implemented in a different form from a simple metal sleeve, and this will be described in more detail below. Figure 1 The marked part is Figure 2 Shown enlarged.

[0041] Figure 2A section of a subframe 2 according to a first embodiment is shown. The upper shell 4 and the lower shell 6 are still shown. A spacer element 10 is arranged between the upper shell 4 and the lower shell 6. The spacer element 10 has a cylindrical base body 14 and a projection 16. In the embodiment shown, the projection 16 is constructed integrally with the base body 14. In addition, the base body 14 also has a hollow cylindrical basic structure. A spacer 18 is molded on the upper shell 4 above the base body 14, for example welded. Bolts can extend from below through holes in the lower shell 6 (not shown in the figure) through the middle cavity of the base body 14 and through the spacer 18, and thereby apply a force that pulls the upper shell 4 and the lower shell 6 together, which is absorbed by the spacer element 10 to prevent deformation of the subframe 2.

[0042] The projection 16 has a substantially flat, flat basic shape. The projection 16 is fixed to the other part of the subframe 2 by means of an edge. In the exemplary embodiment shown, this part of the subframe 2 is a contact surface 20. Here, the contact surface 20 is again a surface belonging to the body, which in the exemplary embodiment shown is oriented substantially vertically. The projection 16 can be connected to the contact surface or to other elements of the subframe 2 by means of a weld, for example, by means of a weld seam or by means of a plurality of weld points.

[0043] Figure 3 A top view of a section of a subframe according to a first embodiment is shown. The lower shell 6, the main body 8 and the spacer element 12 are shown here. It can be seen that the spacer element 12 is composed of a shaped sheet metal. Here, the base body 14 is formed by sections of the sheet metal, and other sections form the projections 16. In the embodiment shown, the spacer element 12 is composed of an originally flat sheet metal, that is, it has been partially rolled up, so that the base body 14 is formed by the rolled sheet metal sections. In the embodiment shown, a gap 26 in the form of a gap remains between the edge that terminates the base body 14 and the flat section of the spacer element 12. In the embodiment shown, the flat section corresponds to the projection 16.

[0044] The projection 16 rests with its end opposite to the base body 14 on the contact surface 20 of the main body 8. In addition, the projection 16 is fixed to the contact surface 20 or the main body 8 by means of a weld 22. The weld 22 is shown simplified here as having a triangular cross section. The weld 22 can be configured as a weld seam, for example. The spacer element 10 is arranged so that it is centered by a hole 24 arranged in the lower shell 6. The hole 24 has a diameter that is smaller than the inner diameter of the base body 14. Bolts or pins can be guided through the hole and the inner cavity of the base body 14 so that the subframe 2 is fixed to the body or body-in-white of the motor vehicle.

[0045] Figure 4Another perspective view of the region of the subframe according to the invention with the spacer element 10 is shown. The lower shell 6, the main body 6 and the spacer element 10 with the base 14 and the projection 16 are shown again. It can be seen that the projection 16 tapers from the base 14 in a trapezoidal manner, so that the length of the weld 22, in other words the axial dimension of the projection 16 along the edge that terminates the projection 16, is smaller than the axial dimension of the base 14. In the embodiment shown, the axial direction coincides with the vertical direction.

[0046] In the embodiment shown, the projection 16 has a central recess 28. To achieve weight reduction, one such recess 28, similar recesses or a plurality of such recesses can be provided. The recess 28 has the shape of an oval slot, wherein the long sides of the slot are oriented parallel to the vertical direction. In addition, the base body has, for example, a semicircular recess 30 at the upper edge. This recess 30 also reduces weight and, in the assembled state, enables gas exchange between the interior of the base body 14 and its surroundings.

[0047] exist Figure 5 1 shows a detail of a side view of a second embodiment. Here, the upper shell 4, the lower shell 6, the body 8 and the spacing element 10 are shown, wherein a section of the upper shell 4 is not shown so that the spacing element 10 can be shown. In the perspective view shown, only the base body 14 is visible, while the projection is located behind the base body 14. Likewise, the contact surface 20 of the body 8 can be seen. The contact surface 20 extends essentially in the vertical direction here.

[0048] Figure 6 A schematic top view of a portion of a third embodiment of a subframe according to the present invention is shown. Figure 5 Sectional view of center line AA. In the embodiment shown, the contact surface 20 or the part of the subframe having the contact surface 20 has a recess 32, through which the end section of the projection 16 passes. The recess 32 can be configured as a slit, for example. In addition, the recess 32 is matched to the projection 16 or the cross section of the projection 16 in terms of its size. And the projection 16 is connected to the contact surface 20 by a weld 22. In the embodiment shown, the weld is arranged on the side of the contact surface 20 opposite to the base 14 of the spacer element 10. However, it is also possible that the weld 22 is arranged on the side of the contact surface 20 facing the spacer element 10. In the embodiment shown, the weld 22 is arranged on the side of the projection 16 facing the base 14. However, it is also possible that the weld 22 is arranged on the side of the projection 16 facing away from the base 14. It is also possible to use multiple welds. The weld can be arranged in two, three or all four possible aforementioned positions.

[0049] Figure 7Other possible ways of implementing the weld 22 are shown. The fourth exemplary embodiment shown corresponds in principle to the second exemplary embodiment, wherein a recess 32 is present in the form of a slit in the contact surface 20, through which the end section of the projection 16 passes. In this case, the weld 22 or the brazing material used for the weld 22 covers the end side of the projection 16 almost completely or completely. The weld 22 is provided here from the side of the contact surface 20 facing away from the base body.

[0050] Figure 8 Another possible design of the spacer element 10 and thus another schematic partial view of a fifth embodiment of the subframe according to the invention are shown. The projection 16 of the spacer element 10 has a deflection or bend 34 in this case, so that the end section of the projection 16 extends at least approximately parallel to the contact surface 20. The end section of the projection 16 extends at an angle of, for example, less than 90°, for example, 60° to 100° relative to the main section of the projection 16. The projection 16 is in turn fixed to the contact surface 20 by means of a weld 22. In the embodiment shown, the end side 36 of the projection 16 is fixed to the contact surface 20 by the weld 22.

[0051] Fig. 9 A schematic top view shows a detail of a sixth embodiment of a subframe according to the invention. Figure 3 The spacing element of the first embodiment shown in FIG. Fig. 9 In the embodiment shown, the protrusion 16 is designed to be thinner than the base body 14. In other words, the protrusion 16 has a smaller material thickness than the base body 14 at least in certain areas. This allows further weight reduction. The material thickness a of the base body 14 can be, for example, 3 mm to 4 mm, and / or the material thickness b of the protrusion 16 can be 2 mm to 3 mm. In a specific exemplary embodiment, the material thickness a of the base body 14 can be 3.5 mm, and the material thickness b of the protrusion 16 can be 2.7 mm.

[0052] Fig.10 A perspective view of a detail of a seventh exemplary embodiment of a subframe according to the invention is shown. In this case, the spacer element 10 has a plurality of recesses 38. The recesses 38 are located in the base body 14 of the spacer element 10 and have the shape of elongated holes. For example, there may be at least two or exactly two, at least three or exactly three, at least four or exactly four recesses 38 or more than four recesses 38. The recesses may, for example, occupy 5% to 40% of the surface or circumferential surface of the base body 14 overall.

[0053] Fig.11The seventh embodiment is shown in another perspective view. It can be seen that a total of five slot-shaped recesses 38 are arranged in the base body 14 of the spacing element 10. In addition, the projection 16 also has a recess 28 in the form of a through hole. The recess 28 has smaller dimensions than the recess 38. In addition, the weld 22 can be seen, which connects the projection 16 to the contact surface 20. In the embodiment shown, the weld 22 consists of a plurality of small spot welds.

[0054] Fig.12 A partial perspective view of an eighth embodiment of the subframe according to the invention is shown. In this embodiment, there is also a recess through the base body 14. In the embodiment shown, the recess 38 is circular and is arranged on a plurality of horizontally oriented lines at different heights around the base body 14. The projection 16 also has a recess 28. In the embodiment shown, the recess 28 is oval in shape. As an alternative, the recess 28 can also be designed as a circular shape. It is possible that the projection 16 also has a plurality of recesses. The recesses can have the same shape or shapes that are different from each other. For example, there is a second recess, which has the shape of an elongated hole.

[0055] exist Fig.13 and Fig.14 A ninth embodiment of the subframe according to the invention is shown in FIG. In this ninth embodiment, the protrusion 16 has a recess 40 which increases the stability and rigidity of the protrusion 16. Fig.13 , a top view is shown in FIG. 1 , in which it can be seen that the recess 40 protrudes from the side of the protrusion 16 from the side. Fig.14 , it can be seen that the recess 40 is formed by shaping the protrusion 16, so that the recess 40 forms a groove when viewed from one side of the protrusion 16, and the recess 40 becomes a raised portion on the other side of the protrusion 16. The recess preferably extends horizontally along the protrusion 16.

[0056] All features of the different embodiments can of course be combined with one another if they are not logically mutually exclusive. Thus, different types of welds 22 can be combined with different designs of the spacer element 10, such as the presence of recesses or other details, without hindrance. In the illustrated embodiment, a preferred embodiment of a cylindrical base body has been described. However, other prismatic basic shapes, such as a cubic base body, are also conceivable and offer the same advantages as a cylindrical base body in terms of strength and rigidity.

[0057] List of Reference Numerals

[0058] 2 Subframe

[0059] 4 Upper shell

[0060] 6 Lower shell

[0061] 8 Main Body

[0062] 10 Spacer element

[0063] 12 Spacer elements

[0064] 14 Matrix

[0065] 16 protrusion

[0066] 18 Spacer

[0067] 20 Contact surface

[0068] 22 Welding Department

[0069] 24 holes

[0070] 26 Gap

[0071] 28 hollow

[0072] 30 hollow

[0073] 32 hollow

[0074] 34 Bend

[0075] 36 End side

[0076] 38 Concave (flat base)

[0077] 40 pit

[0078] F Driving direction

[0079] a Plate thickness

[0080] b Plate thickness

Claims

1. A subframe (2) for a motor vehicle, comprising an upper member and a lower member and comprising at least one spacing element (10) arranged between the upper member and the lower member, wherein: The spacer element (10) has a prismatic base body (14) and is characterized in that the spacer element (10) has a flat projection (16) which is connected to a contact surface (20) of the subframe (2) by means of at least one weld (22).

2. The subframe (2) according to the above claim, characterized in that The projection (16) extends in a plane parallel to the center axis of the base body (14).

3. The subframe (2) according to any one of the preceding claims, characterized in that The weld (22) is a weld seam extending parallel to the center axis of the base body (14).

4. A subframe (2) according to any one of the preceding claims, characterised in that The spacer element (10) is designed in one piece.

5. The subframe (2) according to any one of the preceding claims, characterized in that The spacer element (10) is designed as a partially rolled sheet metal part.

6. The subframe (2) according to any one of the preceding claims, characterized in that A section of the projection (16) passes through a slot arranged in the contact surface (20).

7. The subframe (2) according to any one of the preceding claims, characterized in that The material thickness of the spacer element (10) in the region of the projection (16) is smaller than the material thickness of the spacer element (10) in the region of the base body (14).

8. A spacer element (10) for a subframe (2) of a motor vehicle, comprising a prismatic base body (14), characterized in that: The spacer element has a reinforcement projection to facilitate connection with other elements of the subframe, wherein the reinforcement projection projects from the base body (14).

9. The spacing element (10) according to claim 8, characterized in that The reinforcing projection is flat in design and a surface normal of a main surface of the reinforcing projection is at least approximately perpendicular to a center axis of a base body (14) of the spacer element (10).

10. A motor vehicle comprising a subframe (2) or a spacing element (10) according to any one of the preceding claims.

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