Chassis component for a motor vehicle, in particular in the form of a subframe, and method of manufacturing such a chassis component

Abstract

The invention relates to a chassis component for a motor vehicle, in particular in the form of a front subframe, having at least one cast component (9) made of aluminium, magnesium or an alloy based on aluminium and / or magnesium and at least one profiled or tubular beam (4), wherein the cast component (9) has at least one spigot-shaped beam connecting element (9.4), wherein the beam (4) overlaps the beam-connecting element (9.4) and is connected to the beam-connecting element (9.4) by a weld seam (14), and wherein the cast component (9) has a shoulder at the beam-connecting element (9.4) before the weld seam (14) is produced, which shoulder defines a shoulder flank surface (16). In order to improve such a chassis component with regard to a high strength and life cycle of the welded joint, whereby the chassis component should also have a comparatively low component weight, the invention provides that the shoulder flank surface (16), viewed in the axial direction of the spigot-shaped beam connecting element (9.4) has at least two successive flank sections (16.1, 16.2) of different slope, wherein a first flank section (16.1) of the at least two flank sections, which is closer to the beam (4) than a second of the flank sections, has a greater slope than the second flank section (16.2) axially following this first flank section (16.1), wherein the first flank portion (16.1) together with an end face (17) of the beam (4) defines a groove with a wedge-shaped, U-shaped or semi-U-shaped cross-sectional profile before the weld seam (14) is produced, which groove will be or is at least partially, preferably completely, filled by material of the weld seam (14), and wherein a groove (16.1) which is assigned to the beam (4) is at least partially, preferably completely, filled by material of the weld seam (14), and wherein an edge (14.1) of the weld seam (14) facing away from the support (4) lies on the second flank section (16.2), which has a lower slope. In addition, a method for manufacturing such a chassis part is described and claimed.

Description

[0001]

[0002] August 21, 2025

[0003] Chassis component for a motor vehicle, in particular in the form of a subframe, and method of manufacturing such a chassis component

[0004] The invention relates to a chassis component for a motor vehicle, in particular in the form of a subframe, having at least one cast component made of aluminium, magnesium or an alloy based on aluminium and / or magnesium and at least one profiled or tubular beam, the cast component having at least one spigot-shaped beam connecting element, wherein the beam overlaps the beam-connecting element and is connected to the beam-connecting element by a weld seam, and wherein the cast component has a shoulder at the beam-connecting element before the weld seam is produced, which shoulder defines a shoulder flank surface.

[0005] The chassis component according to the invention can be designed in particular in the form of a front subframe. Alternatively, the chassis component according to the invention can also be designed, for example, as a vehicle main frame or as a chassis control arm.

[0006] Furthermore, the invention relates to a method for manufacturing such a chassis component, in particular in the form of a subframe, for a motor vehicle.

[0007] Subframes for motor vehicles, also known as axle carriers, are known in a wide variety of designs. They should be as light as possible with high strength and rigidity and usually have link connections (bearing mounts) for wheel guide elements and other units in order to enable the installation of complete front or rear axle modules with drive units as a pre-assembly unit. Traditionally, subframes are assembled from longitudinal members and cross members made of steel materials and welded together. Furthermore, subframes are also known whose longitudinal members and cross members are made of aluminium materials. The term "longitudinal members" is understood here to mean supporting elements or sections of supporting elements of the subframe which, in the assembled state of the subframe, extend essentially along the longitudinal axis of the motor vehicle concerned and thus essentially in the direction of travel, while "cross members" are understood to mean supporting elements or sections of supporting elements of the subframe which, in the assembled state of the subframe, extend transversely to the longitudinal axis of the motor vehicle and thus transversely to the direction of travel.

[0008] A subframe is known from EP 3 838 722 Bl, which has at least three beams, of which, in the assembled state of the subframe, at least two beams extend at a distance from each other, substantially along the longitudinal axis of the motor vehicle and at least one beam extends transversely to the longitudinal axis of the motor vehicle, at least one of the beams being an extruded beam. Furthermore, the subframe comprises at least one cast node made of aluminium, magnesium or an alloy based on aluminium and / or magnesium, wherein the cast node connects the extruded beam and at least one of the other beams to each other. For this purpose, the cast node has an armshaped beam connecting element onto which the extruded beam is attached and thus overlaps it. The cast node has a shoulder on the beam connecting element that defines a shoulder end face. The end face of the shoulder on the one hand and the extruded beam and / or the weld seam on the extruded beam on the other delimit a grooveshaped or trench-shaped recess, the average width of which is at least 2.5 times the wall thickness of the extruded beam. The extruded beam is connected to the beam connecting element by a weld seam designed as a lap welded seam. This subframe construction is characterized by a stress-reduced position of the weld seam. However, the creation of a corresponding groove-shaped or trench-shaped recess requires complex machining of the beam connecting element.

[0009] With reference to a vehicle subframe, US 2012 / 0027506 Al describes a weld joint between a cast component made of an aluminium alloy and a tubular wrought material made of aluminium or an aluminium alloy. For this purpose, the cast component has a spigot-shaped connecting element onto which the tubular wrought

[0010] MY / dh 240833WO

[0011] 21 August 2025 material is attached, so that an overlapping form fit is created between the cast component and the wrought material. The cast component to be welded has a shoulder on the connecting element that defines an inclined shoulder flank surface (shoulder end face). The end face of the tubular wrought material to be welded, which defines a groove with the inclined shoulder flank surface of the cast component, is rectangular or plane. The tubular wrought material is arranged on the spigot-shaped connecting element at a distance from the inclined shoulder flank surface of the cast component, so that the groove has a flat bottom which is defined by the outer circumference of the spigot-shaped connecting element. The distance between the tubular wrought material to be welded and the inclined shoulder flank surface should be in the range of 1.0 to 1.7 times the wall thickness of the wrought material at the bottom of the groove. The pitch of the shoulder flank surface or the groove angle should be in the range of 15° to 45°. The weld seam is produced by gas metal arc welding (MIG). The finished weld seam shown in US 2012 / 0027506 Al appears to completely fill the groove and has an outwardly projecting, convexly curved outer side.

[0012] The subframes described in EP 3 838 722 Bl and US 2012 / 0027506 Al are characterized by a comparatively low weight, which is achieved by using cast components and beams or wrought material made of aluminium, magnesium or an alloy based on aluminium and / or magnesium. Such subframes must be able to withstand high loads. This applies in particular to subframes used in electrically powered vehicles, as electric vehicles usually offer a particularly high torque and are particularly heavy compared to vehicles with an internal combustion engine due to the high weight of the rechargeable drive battery. This results in high dynamic loads for the subframe.

[0013] The welding depth (penetration depth) at the butt weld joint has a significant influence on the strength and life cycle of butt weld joints. Internal investigations have shown that the life cycle of butt weld joints with a welding depth of less than 70 to

[0014] MY / dh 240833WO

[0015] 21 August 2025 80% of the maximum possible welding depth at the butt weld joint is dramatically reduced.

[0016] In order to achieve a high penetration depth at a high welding speed when butt welding thick-walled metal components, for example thick-walled metal pipes or cast components, it is known to bevel the butt faces (end faces) to be welded together so that the butt faces facing each other define a V-shaped groove, for example. Furthermore, with regard to butt joint welding of thick-walled pipes or pipe sections, it is known to form a circumferential shoulder at the end of one of the pipes or pipe sections to be welded together, resulting in a connecting spigot that can be inserted into another of the pipes or pipe sections to be welded together. This limits the maximum possible radial offset of the parts to be welded together to the radial play between the connecting spigot and the part attached to it. The connecting spigot can also prevent the weld seam from burning through or molten weld metal from escaping.

[0017] Based on this, the invention is based on the object of improving a chassis component of the type mentioned at the beginning, in particular in the form of a front subframe, with regard to a high strength and life cycle of the welded joint, whereby the chassis component should also have a comparatively low component weight.

[0018] This object is solved by a chassis component having the features specified in claim 1. Advantageous embodiments of the chassis component according to the invention are specified in the subclaims.

[0019] The chassis component according to the invention is characterized in that the shoulder flank surface has at least two successive flank sections of different slope when viewed in the axial direction of the spigot-shaped beam connecting element, a first flank section of the at least two flank sections, which is closer to the beam than a second of the flank sections, having a greater slope than the second flank section following this first flank section axially. The first flank section, together with an end

[0020] MY / dh 240833WO

[0021] 21 August 2025 face of the beam before the weld seam is produced, defines a groove with a wedge- shaped, U-shaped or semi-U-shaped cross-sectional profile, which will be or is at least partially, preferably completely, filled by material of the weld seam, so that an edge of the weld seam facing away from the beam lies on the second flank section, which has a lower slope.

[0022] The edge of the weld seam facing away from the profiled or tubular beam and lying on the second flank section can also be referred to as weld toe.

[0023] The invention is based on the idea of optimizing the fatigue strength and service life of the chassis component with regard to high or increased loads, in particular high drive loads, by positioning and designing the weld seam which connects the profiled or tubular beam, for example an extruded longitudinal or transverse beam, to the cast component, while not significantly increasing the weight of the chassis component, but rather reducing it, if possible, and this with good producibility of the chassis component. The inventors have recognized that this can be achieved by the above- mentioned characterizing features of the chassis component according to the invention. In particular, the inventors have recognized that a smoother weld seam edge position or a smoother or shallower weld seam transition can be achieved by the second flank section having a lower slope. A smoother or shallower weld seam transition reduces the notch effect at the weld seam edge, which can lead to premature failure of the relevant chassis component at the weld seam in the event of high stress on a butt joint weld seam of a chassis component. By preparing the spigotshaped beam connecting element by machining in accordance with the invention in such a way that its shoulder flank surface, viewed in the axial direction, has at least two successive flank sections of different slope prior to the welding process, namely the first flank section, which defines a relatively large slope, and the second flank section, which has a smaller slope in comparison, a weld seam with optimum penetration depth and increased seam width can be reliably and effectively realized, whereby the bending stiffness of the chassis component in the area of the welded joint is improved. The high or complete penetration depth can be ensured by the first flank

[0024] MY / dh 240833WO

[0025] 21 August 2025 section, which defines a significantly greater slope compared to the second flank section.

[0026] The machining preparation of the spigot-shaped beam connecting element, with which the second flank section with a lower slope is produced in addition to the first flank section with a relatively large slope, is also advantageous in terms of improving the surface quality of the chassis component in question. This is because metal casting features, such as protruding casting protrusions (e.g. risers and gates) on the surface of the cast component, can be removed during the machining preparation of the spigot-shaped beam connecting element, saving both time and money.

[0027] An advantageous embodiment of the invention provides that the first flank section defines a gradient angle in the range from 20° to 40°, preferably in the range from 25° to 35°. The first flank section preferably extends to the outside of the spigot-shaped beam connecting element, which is, for example, essentially hollow-cylindrical or almost hollow-cylindrical. In other words, the first flank section and the outside of the spigot-shaped beam connecting element define a circumferential groove. The said gradient angle refers to an axis or plane aligned with the outside of the spigot-shaped beam connecting element. The resulting weld groove angle can, for example, be in the range of 50° to 70°, in particular in the range of 55° to 65°, if the profiled or tubular beam to be welded to the cast component has an end face with right-angled edges. The welding groove is at least partially filled with filler material, for example filler wire made of aluminium, magnesium or an alloy based on aluminium and / or magnesium, when the cast component is welded to the profiled or tubular support.

[0028] A further advantageous embodiment of the invention provides that the second flank section defines a gradient angle in the range from 5° to 20°, preferably in the range from 10° to 15°. This gradient angle relates to an axis or plane which is substantially parallel to the aforementioned axis or plane, which is aligned with the outside of the spigot-shaped beam connecting element, and extends from the lower start of the second flank section or intersects this start of the second flank section.

[0029] MY / dh 240833WO

[0030] 21 August 2025 The end face of the profiled or tubular beam facing the cast component can also be beveled by machining. In combination with the cast component designed according to the invention, this then results in a weld groove with a V-shaped cross-section, for example. According to a preferred and advantageous embodiment of the invention, however, the end face of the profiled or tubular beam facing the cast component is not beveled. This saves the effort of machining the end face of the beam accordingly. In this embodiment of the invention, the end face of the profiled or tubular beam facing the cast component is defined by substantially right-angled edges. This embodiment thus requires that substantially only the cast component is machined in the area of the spigot-shaped beam connecting element. The weld groove, which is defined by the first flank portion of the cast component having a greater slope and the substantially flat end face of the profiled or tubular beam, may be somewhat more difficult to weld with filler material (e.g. filler wire) than a V-shaped weld groove with respect to the angle of attack of the welding torch tip, but said embodiment of the invention requires less filler material to fill the weld groove with filler material. An angle of attack of the welding torch tip which is as large as possible for simple or convenient guidance of the welding torch tip is obtained in said embodiment of the invention by reducing the slope of the first flank portion of the spigot-shaped beam connecting element, wherein the slope of the first flank portion, as mentioned above, may be in the range from 20° to 40°, in particular in the range from 25° to 35°. Where appropriate, this embodiment of the invention includes a slight deburring of the right-angled edges of the end face of the profile-shaped or tubular beam. Such deburring may be limited to less than 10%, preferably less than 5% of the wall thickness of the profiled or tubular beam.

[0031] A further advantageous embodiment of the invention provides that the first flank section ends at a distance in the range from 3 mm to 6 mm, preferably in the range from 3.8 mm to 5 mm, from the end face of the beam. This makes it easier to achieve an optimized result with regard to simple or convenient guidance of the welding torch tip, low filler material consumption for filling the welding groove and an optimum penetration depth of the weld seam.

[0032] MY / dh 240833WO

[0033] 21 August 2025 According to a further advantageous embodiment of the invention, the distance at which the first flank section ends from the end face of the beam is shorter than the distance at which the second flank section ends from the first flank section. This embodiment can contribute to improved fatigue strength of the chassis component in and around the weld seam. To this end, a particularly preferred embodiment of the invention provides that the distance at which the second flank section ends from the first flank section is in the range of 1.5 times to 4 times the distance at which the first flank section ends from the end face of the beam.

[0034] A further advantageous embodiment of the invention is characterized in that the edge of the weld seam facing away from the beam is deeper than the outer surface of the beam adjacent to the weld seam, the depth of said edge of the weld seam relative to the outer surface of the beam adjacent to the weld seam being less than 0.4 times, preferably less than 0.3 times, particularly preferably less than 0.2 times the wall thickness of the beam, measured in the overlap region of the beam and beamconnecting element. This embodiment is favourable to achieve optimized fatigue strength of the chassis component in and around the weld seam, and this with comparatively low filler material consumption for producing the weld seam.

[0035] The weld seam of the welded joint according to the invention is preferably designed in such a way that it has a convexly curved outer side when viewed in cross-section. As a result, the weld seam offers in particular a high bending strength with comparatively low filler material consumption.

[0036] A further advantageous embodiment of the invention provides that the weld seam lies with a weld seam part width on the second flank section having a lower slope, wherein this weld seam part width is more than 3% and less than 40%, preferably less than 30%, particularly preferably less than 25% of the average weld seam width. This configuration is particularly advantageous with regard to reducing the notch

[0037] MY / dh 240833WO

[0038] 21 August 2025 effect mentioned above, whereby the filler material consumption on the second flank section is relatively low.

[0039] Furthermore, the weld seam of the welded joint according to the invention is preferably designed as a circumferential weld seam, preferably a circumferential butt weld seam. This also contributes to an optimized fatigue strength of the chassis component according to the invention, in particular the subframe.

[0040] The cast component of the chassis component according to the invention is, for example designed as a cast node, with the cast component connecting the at least one profiled or tubular beam to at least one further profiled or tubular beam.

[0041] According to a further advantageous embodiment of the chassis component according to the invention, the respective profiled or tubular beam is an extruded beam made of aluminium, magnesium or an alloy based on aluminium and / or magnesium. As a result, the weight of the chassis component according to the invention and thus the overall weight of the motor vehicle concerned can be reduced with regard to reduced fuel or energy consumption and with regard to optimized driving properties of the motor vehicle.

[0042] As mentioned above, the chassis component according to the invention can be designed in particular in the form of a front subframe. Alternatively, the chassis component according to the invention can also be designed, for example, as a vehicle main frame (also called chassis frame) or as a chassis control arm (also called transverse control arm).

[0043] If the chassis component according to the invention is a front or rear subframe for a motor vehicle, then, according to a preferred embodiment, it has at least three beams, of which, in the assembled state of the subframe, at least two beams extend at a distance from one another, substantially along the longitudinal axis of the motor vehicle, and at least one beam extends transversely to the longitudinal axis of the

[0044] MY / dh 240833WO

[0045] 21 August 2025 motor vehicle, at least one of these beams being designed in accordance with the profile-shaped or tubular beam specified in one of the embodiments indicated above.

[0046] A further advantageous embodiment of the invention provides that the chassis component is designed in the form of a subframe, preferably a front subframe, wherein the subframe has at least four beams, of which at least two beams extend at a distance from one another substantially along the longitudinal axis of the motor vehicle when the subframe is mounted, and at least two beams extend at a distance from one another transversely to the longitudinal axis of the motor vehicle, wherein the two beams extending substantially along the longitudinal axis of the motor vehicle and / or the two beams extending substantially transversely to the longitudinal axis of the motor vehicle are designed in accordance with the profile-shaped or tubular beam specified in one of the above-mentioned embodiments, wherein at least four cast components corresponding to said cast component are present, which are each designed as cast nodes and define a closed frame structure with the beams. This embodiment has the advantage that the subframe can absorb high dynamic forces, in particular driving forces, and this with significantly reduced weight compared to conventional subframes with a closed frame structure.

[0047] Furthermore, the above-mentioned object underlying the invention is solved by a method for manufacturing a chassis component for a motor vehicle, in particular in the form of a subframe, in particular according to at least one of the above-mentioned embodiments, with the features specified in claim 15.

[0048] In the method according to the invention, the cast component is worked by machining (i.e. metal cutting) in such a way that the spigot-shaped beam connecting element is created or profiled on the cast component, so that the cast component has a shoulder on the beam connecting element which defines a shoulder flank surface, which, viewed in the axial direction of the beam-connecting element, has at least two successive flank sections of different slope, a first surface section of the at least two surface sections, which is closer to a front end of the beam-connecting element than a

[0049] MY / dh 240833WO

[0050] 21 August 2025 second of the flank sections, having a greater slope than the second flank section axially following this first flank section. The profiled or tubular beam is then connected to the beam connecting element created or profiled on the cast component in an overlapping manner, so that the first flank section together with an end face of the beam defines a groove with a wedge-shaped, U-shaped or semi-U-shaped cross- sectional profile. Subsequently, the beam is connected to the beam connecting element by a weld seam in such a way that the groove is at least partially, preferably completely, filled by material of the weld seam, so that an edge (or a toe) of the finished weld seam facing away from the beam lies on the second flank section, which has a smaller slope.

[0051] The method according to the invention offers the same advantages that were explained above in relation to the chassis component according to the invention and its embodiments. To avoid repetition, reference is therefore made in particular to the preceding description of the chassis component according to the invention and its embodiments.

[0052] In the following, the invention is explained in more detail with reference to a drawing illustrating several embodiments. In the drawing,

[0053] Fig. 1 shows a chassis component according to the invention in the form of a subframe for a motor vehicle, in a perspective view;

[0054] Fig. 2 shows a side member section of the subframe from Fig. 1 with partially illustrated cast components in the form of so-called cast nodes, in a perspective view;

[0055] Fig. 3 shows the longitudinal beam section from Fig. 2 with the partially illustrated cast nodes, in a perspective vertical sectional view;

[0056] MY / dh 240833WO

[0057] 21 August 2025 Fig. 4 shows an enlarged section of one of the cast nodes with a section of the longitudinal member, again in a perspective vertical sectional view, compared to Fig. 3;

[0058] Fig. 5a shows a section of one of the cast nodes with a section of one of the profiled or tubular beams, for example longitudinal beams, in a schematic vertical sectional view;

[0059] Fig. 5b shows an illustration corresponding to Fig. 5a, whereby in Fig. 5b, however, a state is shown during the manufacture of the chassis component (subframe), in which the cast node and the profiled or tubular beam are positively connected to each other but not yet welded together;

[0060] Fig. 5c shows a section of the cast node with a section of the beam welded to it, whereby in Fig. 5c, in contrast to Fig. 5a, it is taken into account and shown schematically that the weld seam extends beyond the boundary surfaces of the original weld groove due to the melting of filler material introduced into the weld groove as well as the material areas to be welded together and bounding the weld groove;

[0061] Fig. 6a - 6b show a further embodiment of weld grooves for producing a welded joint according to the invention of a cast component, preferably a cast node, with at least one profiled or tubular beam, in each case in schematic vertical sectional view; and

[0062] Fig. 7a - 7b show an additional embodiment of weld grooves for producing a welded joint according to the invention of a cast component, preferably a cast node, with at least one profiled or tubular beam, in each case in schematic vertical sectional view.

[0063] MY / dh 240833WO

[0064] 21 August 2025 Fig. 1 shows an embodiment of a subframe 1 according to the invention, which has two opposing profiled or tubular beams 3, 4, also called longitudinal beams, extending essentially along the longitudinal axis of a motor vehicle and thus in the direction of travel V, and two opposing profiled or tubular beams 6, 7, also called transverse beams, extending transversely to the longitudinal axis of the motor vehicle. The beams 3, 4, 6, 7 are connected to each other via cast components in the form of so-called cast nodes 9, 10, 11, 12, whereby the cast nodes 9, 10, 11, 12 together with the beams 3, 4, 6, 7 define a closed frame structure. The reference numeral 13 designates a further optional cross member, which is connected to the cast nodes 11, 12 at the rear in the direction of travel V.

[0065] The cast nodes 9, 10, 11, 12 are provided with bushing-like connecting elements 9.1, 10.1, 11.1, 12.1, which serve to accommodate bolts, so that the subframe 1 can be mounted on a vehicle body by means of screw connections. The cast nodes 9, 10 located at the front in the direction of travel V also have bushing-like connecting elements 9.2, 9.3, 10.2, 10.3 for connecting wheel guide elements (not shown), also known as chassis or transverse control arms, and also brackets 9.8, 10.8 for connecting an engine or other drive unit.

[0066] The cast nodes 9, 10, 11, 12 are cast from aluminium, magnesium or an alloy based on aluminium and / or magnesium. Furthermore, in the embodiment shown in Fig. 1, at least the longitudinal beams 3, 4 are manufactured as extruded beams in the form of extruded profiles made of aluminium, magnesium or an alloy based on aluminium and / or magnesium. Preferably, the cross members 6, 7 are also manufactured as extruded profiles from a corresponding light metal or a corresponding light metal alloy.

[0067] Both the front casting nodes 9, 10 and the rear casting nodes 11, 12 have spigotshaped beam connecting elements onto which the extruded beams, in this embodiment the profiled or tubular longitudinal beams 3, 4, are fitted so that the respective end of the longitudinal beam 3, 4 overlaps the associated beam connecting

[0068] MY / dh 240833WO

[0069] 21 August 2025 element. The spigot-shaped beam connecting elements 9.4, 11.4 of the front cast node 9 and the rear cast node 11 can be seen, for example, in Fig. 3 and Figs. 4 and 5a-5c. The beam connecting elements 9.4, 11.4 are designed in the form of pipe sockets. For permanent fixing of the longitudinal beams 3, 4 to the associated casting nodes 9, 10, 11, 12, the respective longitudinal beam 3, 4 is welded to the beam connecting element of the respective casting node 9, 10, 11, 12 by a weld seam 14.

[0070] To create these welded joints, the respective cast component 9, 10, 11, 12 has a shoulder on the respective beam connecting element before the weld seam 14 is produced, which defines a shoulder flank surface. Such a welded joint, which can also be referred to as a component joint, is shown in Figures 4, 5a and 5c, for example, with regard to the cast component 9 and the longitudinal beam 4. It can be seen that a shoulder was created on the cast component 9 before the weld seam 14 was produced in the area of the previously manufactured beam connecting element 9.4, which defines a shoulder flank surface 16. The beam connecting element 9.4 and the shoulder flank surface 16 are preferably produced by machining. An end face of the beam connecting element 9.4 is designated 9.41.

[0071] The shoulder flank surface 16 has at least two successive flank sections 16.1, 16.2 of different slopes when viewed in the axial direction of the spigot-shaped beam connecting element 9.4, whereby the first flank section 16.1 of these flank sections, which is closer to the beam 4 than the second flank section 16.2, has a greater slope than the second flank section 16.2 following it axially.

[0072] Before the weld seam 14 is produced (cf. Fig. 5b), the first flank section 16.1 of the shoulder flank surface 16 of the cast component, together with the end face 17 of the profiled or tubular beam 4 facing the first flank section 16.1, defines a groove (weld groove) which will be at least partially, preferably completely, filled by welding material of the weld seam 14. The groove may, for example, have a wedge-shaped, in particular V-shaped, or a U-shaped or semi-U-shaped cross-sectional profile. The groove is preferably designed as a circumferential groove.

[0073] MY / dh 240833WO

[0074] 21 August 2025 In the embodiment shown schematically in Figs. 5a - 5c, the end face 17 of the profiled or tubular beam 4 is substantially defined by right-angled edges. Accordingly, the first flank section 16.1 of the shoulder flank surface 16 of the cast component 9, together with the end face 17 of the beam 4, defines a wedge-shaped groove that has a half-V- shaped cross-sectional profile before the weld seam 14 is produced. After the weld seam 14 has been produced using filler material, e.g. welding wire, the groove is at least partially, preferably completely, filled by the material of the weld seam 14, whereby an edge of the weld seam 14 facing away from the beam 4 lies on the second flank section 16.2 of the shoulder flank surface 16 of the cast component 9, which has a lower slope.

[0075] In Fig. 5c, it has been taken into account that the weld seam 14 extends beyond the boundary surfaces 16.1, 17 of the original weld groove due to the melting of filler material introduced into the weld groove as well as the material areas to be welded together and bounding the weld groove. This is shown schematically in Fig. 5c by a dashed outline and a hatched cross-sectional area of the weld seam 14.

[0076] The first flank section 16.1 extends to the outside of the spigot-shaped beam connecting element 9.4, which is preferably substantially hollow-cylindrical or almost hollow-cylindrical. The first flank section 16.1 and the outside of the spigot-shaped beam connecting element 9.4 thus define a circumferential groove. Furthermore, the first flank section 16.1 defines a gradient angle a, which is, for example, in the range of approx. 20° to 40°, preferably in the range of approx. 25° to 35°. The said gradient angle a refers to a plane or axis 18 aligned with the outside of the spigot-shaped beam connecting element 9.4. The second flank section 16.2, which is adjacent to the first flank section 16.1 and has a lower slope, defines a gradient angle p in the range of, for example, approx. 5° to 20°, preferably in the range of approx. 10° to 15°. This gradient angle p refers to a plane or axis 19 that runs substantially parallel to the aforementioned plane or axis 18, which is aligned with the outside of the spigotshaped beam connecting element 9.4, and extends from the lower start of the second flank section 16.2 or intersects this start of the second flank section 16.2 (cf. Fig. 5c).

[0077] MY / dh 240833WO

[0078] 21 August 2025 Before the weld seam 14 is produced, the profile- or tube-shaped beam 4 is positioned on the spigot-shaped beam connecting element 9.4 of the cast component (cast node) 9 in such a way that its inner end edge 17.1 is adjacent or in direct contact with the groove defined by the spigot-shaped beam connecting element 9.4 and the adjoining first flank section 16.1 of the shoulder flank surface 16 (cf. Fig. 5b). The shoulder flank surface 16, which has different slopes, is designed in such a way that the first flank section 16.1 adjacent to the groove ends at a distance Al in the range from 3 mm to 6 mm, preferably in the range from 3.8 mm to 5 mm, from the end face 17 of the beam 4. Furthermore, it can be seen in Fig. 5c that the shoulder flank surface is designed such that the distance Al at which the first flank section 16.1 ends from the end face 17 of the beam 4 is shorter than the distance A2 at which the second flank section 16.2 ends from the first flank section 16.1. The shoulder flank surface 16 can, for example, be designed such that the distance A2 at which the second flank section ends from the first flank section 16.1 is in the range of 1.5 times to 4 times the distance Al at which the first flank section 16.1 ends from the end face 17 of the beam 4.

[0079] The distance A2 at which the second flank section 16.2 ends from the first flank section 16.1 can have different measures on one and the same cast component 9, depending on the shape and contour of the cast component 9. In Figures 5b and 5c, for example, the distance A2 is drawn so that it ends at a point at which a plane or axis 20 aligned with the outside of the beam 4 intersects the second flank section 16.2.

[0080] The weld seam 14 is executed on the shoulder flank surface 16 formed according to the invention in such a way that the toe or edge 14.1 of the weld seam 14 facing away from the beam 4 is lower than the outer surface 22 of the beam 4 adjacent to the weld seam 14 (cf. Fig. 5c). The depth Jd of said toe or edge 14.1 of the weld seam 14 is less than 0.4 times, preferably less than 0.3 times and particularly preferably less than 0.2 times the wall thickness Rt of the beam 4, measured in the overlap area of the beam 4 and the beam connecting element 9.4. In addition, the weld seam 14 is preferably

[0081] MY / dh 240833WO

[0082] 21 August 2025 designed such that it has a convexly curved outer side 14.2 when viewed in crosssection.

[0083] The proportion of the weld seam width W1 with which the weld seam 14 lies on the flank section 16.2 of the shoulder flank surface 16, which has a lower slope, is significantly smaller than the proportion of the weld seam width W1 which extends substantially from the end face 17 of the beam 4 to the end of the first flank section 16.1 of the shoulder flank surface 16 facing away from this end face 17. In other words, the weld seam 14 lies with a partial weld seam width Wl.l on the second flank section 16.2, which has a smaller slope, wherein this partial weld seam width Wl.l is, for example, more than 3% and less than 40%, preferably less than 30%, particularly preferably less than 25% of the average weld seam width W1 (see Fig. 5c).

[0084] The execution of the invention is not limited to the embodiment outlined in Figures 1 to 5c. Rather, numerous variants are conceivable which also make use of the invention claimed in the appended claims in embodiments deviating from the embodiment outlined in Figures 1 to 5c. For example, it is also within the scope of the invention if the first flank section 16.1 of the shoulder flank surface 16 on the spigot-shaped beam connecting element of the cast component, together with an end face 17 of the profileshaped or tubular beam, defines a groove with a semi-U-shaped or U-shaped cross- sectional profile before the weld seam 14 is produced, which will be at least partially, preferably completely, filled by material of the weld seam during the production of the weld seam 14. Corresponding designs are outlined in Figs. 6a and 6b and in Figs. 7a and 7b. In Fig. 6a and Fig. 7a, respectively, a state during the manufacture of the chassis component (e.g. subframe) according to the invention is shown, in which the cast node and the profiled or tubular beam are positively connected to each other but not yet welded together. In Fig. 6b and Fig. 7b, respectively, the weld seam 14 is shown schematically by a dashed outline and a hatched cross-sectional area. Here again it has been taken into account that the weld seam 14 extends beyond the boundary surfaces 16.1’, 17; 16.1’, 17’ of the original weld groove due to the melting of

[0085] MY / dh 240833WO

[0086] 21 August 2025 filler material introduced into the weld groove as well as the material areas to be welded together and bounding the weld groove.

[0087] In the embodiment shown in Figs. 6a and 6b, the first flank section 16.1' of the shoulder flank surface 16 is concave when viewed in the axial direction of the spigotshaped beam connecting element 9.4, while the second flank section 16.2 following the first flank section 16.1' axially is again essentially straight when also viewed in the axial direction. In this embodiment, the slope of the first flank section 16.1' increases steadily from the spigot-shaped beam connecting element 9.4 or the deepest point of the groove in the direction of the second flank section 16.2. The maximum gradient of the first flank section 16.1' corresponds to the gradient of the secant, which begins at the deepest point of the groove and ends at the edge or the transition between the first flank section 16.1' and the following second flank section 16.2. The maximum slope of the first flank section 16.1' is significantly greater than the (maximum) slope of the second flank section 16.2.

[0088] The embodiment sketched in Figs. 7a and 7b differs from the embodiment shown in Figs. 6a and 6b in that the end face 17' of the profiled or tubular beam 4 was machined before the weld seam 14 was produced, so that the end face 17' is concavely chamfered and, together with the first flank section 16.1' of the shoulder flank face 16 of the cast component 9, defines a groove with a U-shaped cross-sectional profile before the weld seam 14 is produced.

[0089] MY / dh 240833WO

[0090] 21 August 2025

Claims

August 21, 2025C l a i m s1. Chassis component for a motor vehicle, in particular in the form of a subframe Cl], with at least one cast component (9, 10, 11, 12) made of aluminium, magnesium or an alloy based on aluminium and / or magnesium and with at least one profiled or tubular beam (3, 4), wherein the cast component (9, 10, 11, 12) has at least one spigot-shaped beam connecting element (9.4), wherein the beam (3, 4) overlaps the beam-connecting element (9.4) and is connected to the beam-connecting element (9.4) by a weld seam (14), and wherein the cast component (9, 10, 11, 12) has a shoulder on the beam connecting element (9.4) before the weld seam (14) is produced, which shoulder defines a shoulder flank surface (16), characterized in that the shoulder flank surface (16) has at least two successive flank sections (16.1, 16.2; 16.1', 16.2) of different slope when viewed in the axial direction of the spigot-shaped beam connecting element (9.4), wherein a first flank section (16.1; 16.1') of the at least two flank sections (16.1, 16.2; 16.1', 16.2), which is closer to the beam (4) than a second of the flank sections (16.1, 16.2; 16.1', 16.2), has a greater slope than the second flank section (16.2) axially following this first flank section (16.1; 16.1'), wherein the first flank section (16.1; 16.1') together with an end face (17; 17') of the beam (4) defines a groove with a wedge-shaped, U-shaped or semi-U-shaped cross-sectional profile before the weld seam (14) is produced, which groove will be or is at least partially, preferably completely, filled by material of the weld seam (14), so that an edge (14.1) of the weld seam (14) facing away from the support (4) lies on the second flank section (16.2) having a smaller slope,wherein the first flank section (16.1; 16.1') defines a gradient angle (a) in the range from 20° to 40°, and wherein the second flank section (16.2) defines a gradient angle (P) in the range from 5° to 20°.

2. Chassis component according to claim 1, characterized in that the first flank section (16.1; 16.1') defines a gradient angle (a) in the range from 25° to 35°.

3. Chassis component according to claim 1 or 2, characterized in that the second flank section (16.2) defines a gradient angle (P) in the range from 10° to 15°.

4. Chassis component according to any one of claims 1 to 3, characterized in that the end face (17) of the beam (4) is defined by right-angled edges.

5. Chassis component according to any one of claims 1 to 4, characterized in that the first flank section (16.1; 16.1') ends at a distance in the range from 3 mm to 6 mm, preferably in the range from 3.8 mm to 5 mm, from the end face (17; 17') of the beam (4).

6. Chassis component according to any one of claims 1 to 5, characterized in that the distance (Al) at which the first flank portion (16.1; 16.1') ends from the end face (17; 17') of the beam (4) is shorter than the distance (A2) at which the second flank portion (16.2) ends from the first flank portion (16.1; 16.1').

7. Chassis component according to any one of claims 1 to 6, characterized in that the distance (A2) at which the second flank section (16.2) ends from the first flank section (16.1; 16.1') is in the range of 1.5 times to 4 times the distance (Al) at which the first flank section (16.1; 16.1') ends from the end face (17; 17') of the beam (4).MY / dh 240833WO21 August 20258. Chassis component according to any one of claims 1 to 7, characterized in that the edge (14.1) of the weld seam (14) facing away from the beam (4) lies deeper than the outer surface (22) of the beam (4) adjacent to the weld seam (14), the depth (Jd) of said edge (14.1) of the weld seam (14) relative to the outer surface (22) of the beam (4) adjacent to the weld seam is less than 0.4 times, preferably less than 0.3 times, particularly preferably less than 0.2 times the wall thickness (Rt) of the beam (4), measured in the overlap region of the beam (4) and the beam connecting element (9.4).

9. Chassis component according to any one of claims 1 to 8, characterized in that the weld seam (14) has a convexly curved outer side (14.2) when viewed in cross-section.

10. Chassis component according to any one of claims 1 to 9, characterized in that the weld seam (14) lies with a partial weld seam width on the second flank section (16.2) having a smaller slope, this partial weld seam width being more than 3% and less than 40%, preferably less than 30%, particularly preferably less than 25% of the mean weld seam width (Wl).

11. Chassis component according to any one of claims 1 to 10, characterized in that the cast component (9, 10, 11, 12) is designed as a cast node and connects the at least one beam (3, 4) to at least one further profile-shaped or tubular beam (6, 7).

12. Chassis component according to any one of claims 1 to 11, characterized in that the respective profiled or tubular beam (3, 4; 6, 7) is an extruded beam made of aluminium, magnesium or an alloy based on aluminium and / or magnesium.

13. Chassis component according to any one of claims 1 to 12, characterized in that the chassis component is designed in the form of a subframe (1), preferably a front subframe, the subframe (1) having at least three beams (3, 4, 6, 7), of which at least two beams (3, 4) extend at a distance from one another, substantiallyMY / dh 240833WO21 August 2025along the longitudinal axis of the motor vehicle, and at least one beam (6, 7) extends transversely to the longitudinal axis of the motor vehicle, at least one of these beams (3, 4, 6, 7) being designed in accordance with the profile-shaped or tubular beam (4) specified in any one of the preceding claims 1 to 12.

14. Chassis component according to any one of claims 1 to 13, characterized in that the chassis component is designed in the form of a subframe (1), preferably a front subframe, the subframe (1) having at least four beams, of which at least two beams (3, 4) extend at a distance from each other, substantially along the longitudinal axis of the motor vehicle in the assembled state of the subframe (1), and at least two beams (6, 7) extend at a distance from each other, transversely to the longitudinal axis of the motor vehicle, wherein the two supports (3, 4) extending substantially along the longitudinal axis of the motor vehicle and / or the two supports (6, 7) extending substantially transversely to the longitudinal axis of the motor vehicle are designed in accordance with the profile-shaped or tubular beam (4) specified in any one of the preceding claims 1 to 12, wherein at least four cast components (9, 10, 11, 12) corresponding to said cast component (9) are present, each designed as a cast node and defining a closed frame structure with the beams (3, 4, 6, 7).

15. Method for manufacturing a chassis component for a motor vehicle, in particular in the form of a subframe (1), according to any one of claims 1 to 14, in which the cast component (9) is worked by machining in such a way that the spigot-shaped beam connecting element (9.4) is created or profiled on the cast component (9), so that the cast component (9) has a shoulder on the beam connecting element (9.4) which defines a shoulder flank surface (16) which, viewed in the axial direction of the beam-connecting element (9.4), has at least two successive flank sections (16.1, 16.2; 16.1', 16.2) of different slope, a first surface section (16.1; 16.1') of the at least two surface sections, which is closer to an end face (9.41) of the beam connecting element (9.4) than a second of the flank sections, has a greater slope than the second flank section (16.2), in which the profiled orMY / dh 240833WO21 August 2025tubular beam (4) is connected to the beam connecting element (9.4) created or profiled on the cast component (9) in an overlapping manner, so that the first flank section (16.1; 16.1') together with an end face (17, 17') of the beam (4) defines a groove with a wedge-shaped, U-shaped or semi-U-shaped cross- sectional profile, and in which subsequently the beam (4) is connected to the beam-connecting element (9.4) by a weld seam (14) in such a way that the groove is at least partially, preferably completely, filled by material of the weld seam (14), so that an edge (14.1) of the finished weld seam (14) facing away from the beam (4) lies on the second flank section (16.2) having a smaller slope.MY / dh 240833WO21 August 2025

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