Multi-point guide arm

Abstract

The invention relates to a multi-point control arm for a chassis of a motor vehicle. The multi-point control arm comprises at least one pair of straight profile sections (6) which are spaced parallel to one another in their longitudinal extension and are separated from one another between their ends (8), wherein the profile sections (6) each have an open, at least substantially C-shaped or U-shaped profile cross section when viewed in cross section, wherein each end (8) of the profile section (6) is connected to a hollow cylindrical joint receptacle (7) via a welded connection (9), and wherein the ends (8) of the profile section (6) intersect the cylindrical, hood-shaped outer circumference (10) of the hollow cylindrical joint receptacle (7) at least substantially in a T-shaped manner. The invention is characterized in that the welded connection (9) between the profile section (6) and the hollow cylindrical joint receptacle (7) is respectively constructed as a fillet weld (9) with a wedge-shaped weld cross section, which is only implemented on the outer sides (11) of at least one pair of profile sections (6) facing away from each other, so that the inner sides (19) of the profile sections (6) facing each other are free of welds.

Description

Technical Field

[0001] The invention relates to a multi-point guide arm. Background Art

[0002] Axle suspensions for commercial vehicles, such as those used for commercial freight or passenger transport, typically have rigid axles guided by multi-point control arms. These rigid axles can be guided by three-point control arms, which are arranged above the rigid axles in the upper control arm level when the commercial vehicle is viewed from the side. In the lower control arm level, these rigid axles can be guided on each vehicle side by a torsion bar extending in the longitudinal direction of the vehicle. These torsion bars are two-point control arms with two end-side support areas connected to each other by a straight connecting section. Two-point control arms with end-side support areas connected by a straight connecting section are used not only for guiding rigid axles in commercial vehicles but also at other installation locations in the vehicle chassis.

[0003] DE 10 2010 013 518 A1 discloses a two-point link for a vehicle chassis, which is referred to herein as a connecting strut. The two-point link has a hinge region at each of its ends, each with a hollow cylindrical hinge receptacle for a rubber mount, wherein the rubber mount is designed as a cylindrical mount. The two hollow cylindrical hinge receptacles are connected to each other by a straight connecting section formed by two support elements spaced parallel to each other. The two support elements are welded to the two hollow cylindrical hinge receptacles at their ends and are otherwise separate from each other. Furthermore, the two support elements, which are straight profile sections, have a constant cross-section along their longitudinal extent, each being designed as an open profile cross-section in the form of a circular ring segment. The outer edges of the two support elements point away from each other. With respect to their longitudinal axes, the two support elements have low torsional rigidity and high flexural rigidity. Summary of the Invention

[0004] The object of the present invention is to provide an alternative structure of a multi-point control arm.

[0005] According to the invention, this object is achieved by a multi-point guide arm as described below.

[0006] Preferred embodiments and developments of the invention, as well as further features and details, can be found in the description and the drawings.

[0007] The present invention therefore proposes a multi-point control arm for a chassis of a motor vehicle, comprising at least one pair of straight profile sections that are spaced parallel to one another in their longitudinal extension and separated from one another at their ends. Viewed in cross section, the profile sections each have an open, at least substantially C-shaped or U-shaped profile cross section. Each end of the profile section is connected to a hollow cylindrical joint receptacle via a welded connection. The ends of the profile sections intersect the cylindrical, hood-shaped outer circumference of the hollow cylindrical joint receptacle at least substantially in a T-shape.

[0008] According to the invention, the welded connections between the profile sections and the hollow cylindrical joint receptacles are each designed as fillet welds with a wedge-shaped weld cross section. The fillet welds are only made on the outer sides of at least one pair of profile sections facing away from each other, so that the inner sides of the profile sections facing each other are free of welds.

[0009] Tests conducted by the applicant revealed the surprising result that, through fillet welds formed only on the outside of the profile segments, forces and moments acting on the multi-point control arm can be transferred to approximately the same extent as in an embodiment in which additional fillet welds are formed on the inside of the profile segments. Further tests conducted by the applicant have shown that this effect cannot be achieved if fillet welds are formed only on the inside of the profile segments. This effect cannot be achieved even when using a circumferentially closed tubular profile as the connection between two hollow cylindrical joint receptacles, as the spacing between at least one pair of straight profile segments is particularly important.

[0010] Since the inner sides of the parallel, spaced-apart profile sections facing each other are free of welds, the manufacturing costs of multi-point guide arms can be reduced. Furthermore, this allows for expanded design possibilities, such as relatively small parallel spacing between the two profile sections, which is not possible when the fillet welds are formed on the inner sides of the profile sections. This is because the two parallel, spaced-apart profile sections must be at a minimum distance from each other when the fillet welds are formed on the inner sides of the profile sections in order to provide access for welding the fillet welds on the inner sides. Even if such accessibility is provided, for example, for a welding head, this can only be performed uninterrupted (i.e., without removing the welding head) when the two profile sections are at a relatively large parallel spacing. This typically requires welding from both sides, which increases production time. In contrast, fillet welds formed only on the outer sides of the profile sections can be welded without any problems, without having to remove them, thus reducing production time.

[0011] In a fillet weld connection, the components to be welded together are at least essentially at right angles to one another. The weld seam has a substantially triangular cross-section, with a slight notch on the free outer side. The T-shaped intersection of the ends of the profile segments and the cylindrical, cap-shaped outer surface of the hollow cylindrical joint receptacle is also known in welding technology as a T-joint. Fillet welds can be produced, for example, by metal active gas welding (MAG), metal inert gas welding (MIG), or electrode welding.

[0012] At least one pair of straight profile sections is connected to one another, in particular at both ends, by a hollow cylindrical joint receptacle. The profile sections are, in particular, separate profile sections that exist as separate, individual parts in the initial state, i.e., before being welded to the hollow cylindrical joint receptacle. The two profile sections of at least one pair of straight profile sections are, in particular, exactly the same length, or at least substantially the same length. For the purposes of the present invention, an open profile cross section is understood to mean a profile section that, viewed in cross section, has a non-linear, non-circular, closed path. An open profile section can also be understood to mean a profile section that, viewed in cross section, has a convex side and a concave side, with the opening of the open profile section being located on the concave side. The concave side is also referred to as an open profile side.

[0013] Viewed in cross section, the profile segments are shaped, in particular, in the manner of circular ring segments. In particular, the profile segments are designed to be symmetrical, viewed in cross section. The profile segments of at least one pair are designed, in particular, symmetrically with respect to a plane spanned by the joint axis of the hollow cylindrical joint receptacle. In particular, the two profile segments are designed to be straight in their longitudinal extension in the unloaded state, so that they do not bend in the direction of their longitudinal axis. The profile segments are in particular cylindrical, i.e., they correspond to a column with an at least substantially C-shaped or U-shaped base surface, which extends perpendicularly to the base surface. Alternatively, the profile segments can also each have an open, at least substantially V-shaped or L-shaped profile cross section, viewed in cross section.

[0014] The hollow cylindrical joint receptacle has, in particular, a circumferentially closed cross-section. The hollow cylindrical joint receptacle is, in particular, substantially hollow-cylindrical in design. In particular, the hollow cylindrical joint receptacle may have slight geometric deviations from the ideal hollow cylindrical shape, for example due to a circumferential inner groove for the retaining ring and / or a circumferential stop surface for the supporting ring of the inner part of the rubber-to-metal joint. In this case, a joint receptacle with such slight geometric deviations from the ideal hollow cylindrical shape should also be considered a hollow cylindrical joint receptacle. Preferably, the hollow cylindrical joint receptacle is suitable for accommodating the inner part of a rubber-to-metal joint, in particular a molecular joint. Molecular joints are preferably used in the chassis of motor vehicles because they are maintenance-free and insensitive to dirt, salt water, and stone impacts.

[0015] Advantageously, the fillet weld extends into the gap between the end faces of the profile segment and the cylindrical, hood-shaped outer circumference of the associated hollow cylindrical joint receptacle. The further the fillet weld extends into the gap, the lower the notch stress at the base (i.e., at the point of the fillet weld that extends furthest into the gap). This is because, when a multi-point control arm is subjected to tensile or compressive loading, a biaxial stress state occurs at the base. Under this biaxial stress state, tensile and compressive stresses acting at least substantially perpendicularly to one another in the base region at least partially compensate for one another. The tensile and compressive stresses acting at least substantially perpendicularly to one another in the base region occur, on the one hand, at the ends of the profile segment and, on the other hand, at the correspondingly associated cylindrical, hood-shaped outer circumference of the hollow cylindrical joint receptacle. The profile of the end faces of the profile segment is specifically adapted to the profile of the cylindrical, hood-shaped outer circumference, so that the gap remains at least substantially geometrically constant throughout its entire longitudinal extent.

[0016] The fillet weld preferably extends from the outside of the profile segment to the inside, thus completely filling the gap between the end face of the profile segment and the cylindrical, hood-shaped outer circumference of the associated hollow-cylindrical joint receptacle. This feature of the fillet weld provides an optimal solution for minimizing the notch stresses that occur at the base under the load of the multi-point control arm. Fillet welds that extend to the inside of the profile segment are particularly designed as so-called HV (half-V) welds. In an HV weld, only one joint part, particularly the end of the profile segment, is inclined, while the cylindrical, hood-shaped outer circumference of the other joint part, particularly the associated hollow-cylindrical joint receptacle, is straight.

[0017] The end faces of the profile segments advantageously have a chamfered edge, which is designed so that the gap between the end faces of the profile segments and the cylindrical, hood-shaped outer circumference of the hollow cylindrical joint receptacle tapers in a wedge-shaped manner from the outside of the profile segments toward the inside. This allows for easy welding of HV weld seams on the outer sides of at least one pair of profile segments facing away from each other.

[0018] According to a refinement of the present invention, the open profile sides of at least one pair of profile sections point at least substantially in the same direction as the joint axis of the hollow-cylindrical joint receptacle. The joint axis of the hollow-cylindrical joint receptacle is particularly aligned with its axis of rotation. The joint axes are oriented parallel to one another, particularly when the multi-point control arm is in the unloaded state. When installed in a motor vehicle, the joint axes are typically oriented parallel to the roadway; for example, when the multi-point control arm is designed as a torsion bar for guiding a rigid axle. In such an installation, it is advantageous for the open profile sides of the two profile sections to point in the direction of the joint axis, as this avoids bucket-shaped geometric areas where, for example, moisture, dirt, or corrosive media could undesirably accumulate.

[0019] Furthermore, the profile segments are arranged so that the open profile sides are oriented in the direction of the joint axis of the hollow cylindrical joint receptacle, creating a self-centering effect. This has a positive impact on the effort required to orient the profile segments relative to the hollow cylindrical joint receptacle before welding fillet welds, particularly HV welds. The ends of the profile segments, with their end faces, sit, in a manner similar to a rider in a saddle, on the corresponding cylindrical, circumferential outer surface of the hollow cylindrical joint receptacle. The end faces of the profile segments are particularly symmetrical with respect to a plane spanning the joint axis of the hollow cylindrical joint receptacle. This self-centering arrangement is also advantageous because, even when the multi-point guide arm is subjected to pressure, the end faces of the profile segments cannot be pushed away from the cylindrical, circumferential outer surface of the hollow cylindrical joint receptacle due to their geometry. When the multi-point guide arm is subjected to pressure, this "saddle-like arrangement" creates a symmetrical loading situation in the fillet weld. This is not the case if the open profile sides of at least one pair of profile sections are oriented perpendicularly to the joint axis of the hollow cylindrical joint receptacle. The end sides of the profile sections are in particular concave. In particular, the end sides of the profile sections are in the shape of a circular arc when viewed in the direction of the joint axis.

[0020] Advantageously, the open profile sides of at least one pair of profile sections are oriented toward each other. This creates favorable conditions for loading a multi-point control arm, as the at least one pair of profile sections is generally designed like a double-slit tube with opposing longitudinal cuts in cross section. Consequently, the corresponding single-sided fillet welds between the ends of the profile sections and the associated hollow cylindrical joint receptacles are also implemented on the outer sides of the protrusions of the profile sections in cross section. The longitudinal outer edges of the two profile sections with their open profile sides facing each other also face each other and are arranged opposite each other. The cut between the two profile sections with their open profile sides facing each other has a width that is substantially equivalent to the sheet metal thickness of the profile sections. Thus, for a profile section sheet thickness of 6.5 mm, the cut can be, for example, 10 mm wide. Alternatively, the open profile sides of at least one pair of profile sections can be oriented away from each other.

[0021] Advantageously, the outer diameter of the hollow-cylindrical joint receptacle is larger than the smallest possible enveloping circle surrounding the at least one pair of profile segments, viewed in cross section. In this context, the enveloping circle refers to the smallest possible circumscribed circle. In order for fillet welds formed solely on the outer sides of the at least one pair of profile segments, facing away from each other, to be sufficient to connect the profile segments to the hollow-cylindrical joint receptacle, the ends of the profile segments must be at least substantially perpendicular to the cylindrical, mantle-like outer circumference of the hollow-cylindrical joint receptacle. If the smallest possible enveloping circle surrounding the at least one pair of profile segments were, for example, identical to the outer diameter of the hollow-cylindrical joint receptacle, the outer regions of the end faces of the profile segments would be approximately tangential to the cylindrical, mantle-like outer circumference of the hollow-cylindrical joint receptacle. In this case, the described effect of having the forces and moments that can be transmitted by fillet welds formed solely on the outer sides of the profile segments be approximately the same as in an embodiment with additional fillet welds on the inner sides of the profile segments cannot be achieved.

[0022] Furthermore, advantageously, the wall thickness of the hollow-cylindrical joint receptacle in the region of the fillet weld substantially corresponds to the sheet metal thickness of the profile segment, i.e., the distance between the outer side of the profile segment and the corresponding associated inner side. The aforementioned at least partial compensation of tensile and compressive stresses in the region of the fillet weld root can only occur if the flexibility of the two joint partners is substantially the same. If, for example, the hollow-cylindrical joint receptacle is not hollow but solid, the aforementioned at least partial compensation of tensile and compressive stresses in the region of the fillet weld root does not occur. In particular, the wall thickness of the hollow-cylindrical joint receptacle and the sheet metal thickness of the profile segment differ by less than 50%, preferably by less than 40%, and particularly preferably by less than 30%.

[0023] Preferably, the joint axis of the hollow cylindrical joint receptacle extends at least substantially perpendicularly to the longitudinal sides of the profile segments. "Substantially" is to be interpreted relatively broadly, so that joint axes which form an angle of up to + / - 45° with the longitudinal axis of the profile segments arranged in pairs also fall within this scope, as is the case, for example, with a three-point control arm.

[0024] According to a first alternative, the multi-point control arm is designed as a two-point control arm, in particular as a torsion bar, for guiding the rigid axle.

[0025] According to a second alternative, the multi-point control arm is designed as a three-point control arm, in particular for guiding a rigid axle.

[0026] Preferably, the inner portion of the rubber-metal joint is at least partially accommodated in the hollow cylindrical joint receptacle. This inner portion, together with the hollow cylindrical joint receptacle that accommodates it, forms the rubber-metal joint. The inner portion of the rubber-metal joint has a ball, which in effect serves as the axis of the rubber-metal joint. The annular intermediate space between the ball and the hollow cylindrical joint receptacle is filled with a surrounding elastomer. The elastomer is fixed in the intermediate space under preload. The elastomer can have the shape of a hollow cylinder, thereby forming a so-called cylindrical joint. The elastomer is surrounded by two supporting rings, particularly in the direction of the joint axis. In the installed state, the ball can move relative to the corresponding hollow cylindrical joint receptacle under the action of force. The material of the elastomer has restorative properties that cause the ball to return to its undeflected zero position after the force is released. When installed in a motor vehicle, the elastomer compensates for axial and / or radial and / or torsional and / or cardanic swings of the ball relative to the corresponding hollow cylindrical joint receptacle during driving by elastic deformation. In this way, a rigid axle, for example, can be connected to the vehicle frame in an articulated manner via a multi-point control arm with rubber-metal joints.

[0027] The inner part of the rubber-metal joint advantageously has a spherical joint region to enable universal motion. This inner part with a spherical joint region, together with the hollow cylindrical joint receptacle that accommodates it, forms a rubber-metal joint, also known as a molecular joint. To form the spherical joint region, the ball element has a spherical region that is annularly surrounded by an elastomer. Universal pivoting is achieved at least substantially around the spherical region of the ball element. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention is further explained below with reference to the accompanying drawings, which illustrate only exemplary embodiments, wherein identical reference numerals designate identical, similar, or functionally identical components or elements.

[0029] Figure 1An axle suspension according to the prior art is shown in a top view;

[0030] Figure 2 The multi-point guide arm according to the first embodiment of the present invention is shown in a top view;

[0031] Figure 3 The cross-sectional view shows Figure 2 The multi-point guide arm according to the cutting line A–A specified therein;

[0032] Figure 4 The cross-sectional view shows Figure 3 The multi-point guide arm according to the cutting line B–B specified therein;

[0033] Figure 5 Shown in top view (through detailed view) Figure 2 Multi-point guide arm under tensile load;

[0034] Figure 6 Shown in top view (through detailed view) Figure 2 Multi-point guide arms under pressure load; and

[0035] Figure 7 A multi-point control arm according to a second embodiment of the present invention is shown in a top view. DETAILED DESCRIPTION

[0036] Figure 1 The axle suspension 1 of a rigid axle for two wheels of a motor vehicle chassis is shown. The rigid axle has a rigid axle body 2 extending in the vehicle's transverse direction, to which a multi-point link is connected. The multi-point link is designed as a three-point link 3. The three-point link 3 has two link arms that enclose an acute angle with each other and intersect at a central joint. The three-point link 3 is articulatedly connected to the rigid axle body 2 via the central joint. The free ends of the two link arms can be connected to the vehicle frame (not shown) via a rubber-metal joint 12. Laterally spaced apart from the three-point link 3 and at a lower height, offset from the three-point link 3 and extending substantially parallel to the plane of the drawing, two multi-point link arms, designed as torsion bars, are connected to the rigid axle body 2 at their ends. The torsion bars are two-point link arms 4 that extend in the vehicle's longitudinal direction, perpendicular to the vehicle's transverse direction, and are therefore also referred to as longitudinal links. The two-point control arm 4 has a molecular joint 12 at each of its ends. The axle suspension 1 also has a roll stabilizer 5 which is connected to the rigid axle body 2 in a pivotable manner.

[0037] exist Figure 2The multi-point control arm shown in FIG is constructed as a two-point control arm 4, also known as a torsion bar and suitable for use in the chassis of a motor vehicle. The two-point control arm 4 has exactly one pair of straight profile sections 6. The two profile sections 6 are spaced parallel to each other in their longitudinal extension and are also separated from each other between their ends 8. Viewed in cross section, the profile sections 6 each have an open, C-shaped profile cross section. Each end 8 of the profile section 6 is connected to the hollow cylindrical joint receptacle 7 by a MIG-welded fillet weld 9 with a wedge-shaped weld cross section. Here, the ends 8 of the profile section 6 intersect the cylindrical, hood-shaped outer circumference 10 of the hollow cylindrical joint receptacle 7 in a T-shape. The fillet welds 9 are applied only on the outer sides 11 of the two profile sections 6 facing away from each other.

[0038] As from Figure 3 As can be seen, the open profile sides 14 of the two profile sections 6 point in the same direction as the joint axis 15 of the hollow cylindrical joint receptacle 7. When the profile sections 6 are viewed in cross section, the open profile sides 14 are concave. Furthermore, the open profile sides 14 of the two profile sections 6 are oriented toward each other. The longitudinal outer edges of the two profile sections 6 also face each other and are arranged opposite each other. Viewed in cross section, the two profile sections 6 are arranged symmetrically. The cutout 16 between the two profile sections 6 has a width of 10 mm. The profile sections 6 have a sheet metal thickness 17 of 6.5 mm. The outer diameter of the hollow cylindrical joint receptacle 7 is larger than the smallest possible envelope 18 surrounding the two profile sections 6, viewed in cross section. The fillet welds 9 are applied only to the outer sides 11 of the projections of the two profile sections 6 facing away from each other, leaving the inner sides 19 of the two profile sections 6 facing each other free of welds.

[0039] exist Figure 4 As can be seen in the figure, the joint axis 15 of the hollow-cylindrical joint receptacle 7 coincides with the axis of rotation of the hollow-cylindrical joint receptacle 7. The wall thickness 20 of the hollow-cylindrical joint receptacle 7 corresponds essentially to the sheet metal thickness 17 of the profile section 6, that is, the distance between the outer side 11 of the profile section 6 and the correspondingly associated inner side 19. The wall thickness 20 of the hollow-cylindrical joint receptacle 7 is 8 mm, and the sheet metal thickness 17 of the profile section 6, as already explained, is 6.5 mm. Therefore, the wall thickness 20 of the hollow-cylindrical joint receptacle 7 is approximately 19% smaller than the sheet metal thickness 17 of the profile section 6. The joint axis 15 of the hollow-cylindrical joint receptacle 7 extends perpendicularly to the longitudinal sides of the profile section 6.

[0040] The fillet weld 9 extends into the gap 21 between the end face 22 of the profile section 6 and the cylindrical hood-shaped outer circumference 10 of the hollow cylindrical joint receptacle 7 and completely fills the gap 21. Thus, the fillet weld 9, which is designed here as an HV weld, extends in its transverse extent in the direction of the joint axis 15 from the outer side 11 of the profile section 6 to the inner side 19 of the profile section. The end face 22 of the profile section 6 is adapted in its course to the contour of the cylindrical hood-shaped outer circumference 10, so that the gap 21 is designed to remain at least substantially geometrically constant over its entire longitudinal extent along the outer circumference of the hollow cylindrical joint receptacle 7. The end sides 22 of the profile section 6 each have a chamfered corner 23 which is designed such that the gap 21 in its transverse extension between the end sides 22 of the profile section 6 and the cylindrical, hood-shaped outer circumference 10 of the hollow cylindrical joint receptacle 7 tapers in a wedge-shaped manner from the outer side 11 of the profile section 6 to the inner side 19 of the profile section 6 .

[0041] The inner portion 24 of the rubber-metal joint 12 is accommodated in the hollow-cylindrical joint receptacle 7. Together with the hollow-cylindrical joint receptacle 7 that accommodates it, the inner portion 24 forms the rubber-metal joint 12. The inner portion 24 has a ball 25, which serves as a shaft for the rubber-metal joint 12. The annular space between the ball 25 and the inner wall of the hollow-cylindrical joint receptacle 7 is filled with a surrounding elastomer 26, which is fixed in the space under preload. The ball 25 has a central spherical region that is annularly surrounded by the elastomer 26. Thus, the rubber-metal joint is designed as a modular joint 12 with a spherical joint region 27. The universal pivoting of the modular joint 12 occurs at least substantially around the spherical joint region 27. The elastomer 26 is surrounded by two support rings in the direction of the joint axis 15. The hollow cylindrical joint receptacle 7 has an inner groove for the locking ring and a stop surface for the supporting ring and therefore has slight geometric deviations from the ideal hollow cylindrical shape.

[0042] Figure 5 This explains why, by forming the fillet weld 9 only on the outer sides 11 of the pair of profile sections 6 facing away from each other, a tensile force F acting on the two-point control arm 4 of approximately the same magnitude can be transmitted as in an embodiment in which an additional fillet weld is formed on the inner sides 19 of the pair of profile sections 6. Zug The two-point guide arm 4 is loaded with a tensile force F. ZugThe stresses occurring in the region of the fillet weld 9, which is formed only on the outer side 11 of the profile section 6, are shown. Two arrows pointing away from each other (with three dots drawn between them) represent tensile stresses, while two arrows pointing toward each other (with three dots drawn between them) represent compressive stresses. In the region of the base 28, that is, at the point where the fillet weld 9 extends furthest into the gap 21 between the end face 22 of the profile section 6 and the cylindrical, hood-like outer surface 10 of the hollow-cylindrical joint receptacle 7, tensile and compressive stresses intersect at right angles. This intersection of tensile and compressive stresses creates a biaxial stress state in the region of the base 28, in which the intersecting tensile and compressive stresses partially compensate for each other in their effects, resulting in a reduction in notch stresses in the region of the base 28. The further the fillet weld 9 extends into the gap 21, the lower the notch stresses at the base 28.

[0043] The effect already explained above, according to which forces and moments of approximately the same magnitude can be transmitted by the fillet weld 9 formed only on the outer side 11 of the profile section 6 as in the embodiment with an additional weld on the inner side 19 of the profile section 6, is also achieved in that the straight profile sections 6 - which in the unloaded state of the two-point control arm 4 are spaced parallel to each other in their longitudinal extension and at the same time separated from each other between their ends 8 - are loaded with a tensile force F Zug The width of the cutout 16 is designed so that the profile section 6 is still exposed to the maximum permissible tensile force F when the two-point control arm 4 is in contact with each other. Zug In order to achieve the described effect, it is also necessary that the wall thickness 20 of the hollow cylindrical joint receptacle 7 corresponds at least substantially to the sheet metal thickness 17 of the profile section 6 .

[0044] Figure 6 This explains why, by forming the fillet weld 9 only on the outer sides 11 of the pair of profile sections 6 facing away from each other, approximately the same pressure force F acting on the two-point control arm 4 can be transmitted as in the embodiment in which an additional fillet weld is formed on the inner sides 19 of the pair of profile sections 6. Druck The load pressure F for the two-point guide arm 4 is shown symbolically. Druck The stresses that occur in the area of the fillet weld 9 formed only on the outer side 11 of the profile section 6 are shown here. Here too, two arrows pointing away from each other (with three points drawn between them) represent tensile stresses, while two arrows pointing towards each other (with three points drawn between them) represent compressive stresses. In the area of the base 28, the tensile and compressive stresses meet again at right angles and also partially compensate for each other in their effects. However, the tensile and compressive stresses are shown here in the same way as in the case of the two-point control arm 4 described above, which is subjected to the tensile force F. ZugLoading situation Different situations converge.

[0045] The two-point guide arm 4 is subjected to the pressure F Druck When loaded, the straight profile sections 6, which in the unloaded state of the two-point control arm 4 are spaced parallel to one another in their longitudinal extension and at the same time separated from one another between their ends 8, move away from one another in the region of their longitudinal center. This effect is shown exaggerated here to illustrate the behavior of the profile sections 6 under compressive load. In order to partially compensate for the tensile and compressive stresses in the region of the base 28, it is also necessary for the wall thickness 20 of the hollow cylindrical joint receptacle 7 to correspond substantially to the sheet metal thickness 17 of the profile sections 6.

[0046] Figure 7 A multi-point control arm for a motor vehicle chassis is shown, wherein the multi-point control arm is configured as a three-point control arm 3 for guiding a rigid axle. The three-point control arm 3 has two pairs of straight profile sections 6. The two pairs of profile sections 6 are spaced parallel to each other in their longitudinal extension and separated from each other at their ends 8. Viewed in cross section, the profile sections 6 each have an open, C-shaped profile cross section. Each end 8 of the profile section 6 is connected to a hollow cylindrical joint receptacle 7 via a welded connection 9. Here, the ends 8 of the profile section 6 intersect the cylindrical, hood-shaped outer surface 10 of the hollow cylindrical joint receptacle 7 in some cases in a tight fit and in other cases in a substantially T-shaped manner. The inner portion 24 of the rubber-metal joint 12 is accommodated in the hollow cylindrical joint receptacle 7. Together with the hollow cylindrical joint receptacle 7 that accommodates it, the inner portion 24 forms the rubber-metal joint 12. The welded connections 9 between the profile segments 6 and the hollow-cylindrical joint receptacles 7 are each designed as fillet welds 9 with a wedge-shaped weld cross-section. The fillet welds 9 are each made only on the outer sides 11 of the two pairs of profile segments 6 facing away from each other. The two pairs of profile segments 6 converge at an acute angle and meet in one of the hollow-cylindrical joint receptacles 7, which, together with the associated inner portion 24, is also referred to as a central joint. A total of four ends 8 of the two pairs of profile segments 6 are welded to the cylindrical, hood-shaped outer circumference 10 of the hollow-cylindrical joint receptacle 7 at angles other than 90 degrees.

[0047] Reference Signs List

[0048] 1 Axle suspension

[0049] 2 Rigid shaft

[0050] 3Multi-point guide arm, three-point guide arm

[0051] 4Multi-point guide arm, two-point guide arm, torsion bar

[0052] 5 Roll Stabilizer

[0053] 6 profile sections

[0054] 7 Hollow cylindrical joint receptacle

[0055] 8 End of profile section

[0056] 9Welded joints, fillet welds

[0057] 10. Cylindrical outer surface

[0058] 11 Outer side of profile section

[0059] 12 Rubber-metal joints, molecular joints

[0060] 14 open profile side

[0061] 15 The joint axis of the hollow cylindrical joint receiving portion

[0062] 16 incision

[0063] 17 Plate thickness

[0064] 18 Enveloping Circle

[0065] 19 Inside of profile section

[0066] 20 Wall thickness of the hollow cylindrical hinge receiving portion

[0067] 21 Gap

[0068] 22 End side of profile section

[0069] 23 Bevel Chamfer

[0070] 24 Inner part of the rubber-metal joint

[0071] 25 spherical parts

[0072] 26 Elastomer

[0073] 27 Spherical joint area

[0074] 28 foundation

[0075] F Zug pull

[0076] F Druck pressure.

Claims

1. A multi-point control arm for the chassis of a motor vehicle, comprising at least one pair of straight profile sections (6) which are spaced apart parallel to one another in their longitudinal extension and which are separated from one another between their ends (8), -in, The profile sections (6) each have an open, at least substantially C-shaped or U-shaped profile cross section when viewed in cross section. wherein each end (8) of the profile section (6) is connected to the hollow cylindrical joint receptacle (7) via a welded connection (9), and wherein the end (8) of the profile section (6) intersects the cylindrical, hood-shaped outer circumference (10) of the hollow cylindrical joint receptacle (7) at least essentially in a T-shape, It is characterized by: The welded connection (9) between the profile section (6) and the hollow cylindrical joint receptacle (7) is each designed as a fillet weld (9) with a wedge-shaped weld cross section, which is only implemented on the outer sides (11) of the at least one pair of profile sections (6) facing away from each other, so that the inner sides (19) of the profile sections (6) facing each other are free of welds. wherein the open profile sides (14) of the at least one pair of profile sections (6) are oriented facing each other, and The open profile sides (14) of the at least one pair of profile sections (6) are oriented at least substantially in the same direction as the joint axis (15) of the hollow cylindrical joint receptacle (7).

2. The multi-point guide arm according to claim 1, characterized in that: The fillet weld (9) extends into a gap (21) between the end face (22) of the profile section (6) and the cylindrical, hood-shaped outer circumference (10) of the associated hollow-cylindrical joint receptacle (7).

3. The multi-point guide arm according to claim 2, characterized in that: The fillet weld (9) extends from the outer side (11) of the profile section (6) to the inner side (19) of the profile section (6) and thus completely fills the gap (21) between the end side (22) of the profile section (6) and the cylindrical hood-shaped outer circumference (10) of the associated hollow cylindrical joint receptacle (7).

4. The multi-point guide arm according to claim 2, characterized in that: The end side (22) of the profile section (6) has a chamfer (23) which is designed so that a gap (21) between the end side (22) of the profile section (6) and the cylindrical hood-shaped outer circumference (10) of the hollow cylindrical joint receptacle (7) tapers in a wedge shape from the outer side (11) of the profile section (6) towards the inner side (19) of the profile section (6).

5. The multi-point guide arm according to claim 3, characterized in that: The end side (22) of the profile section (6) has a chamfer (23) which is designed so that a gap (21) between the end side (22) of the profile section (6) and the cylindrical hood-shaped outer circumference (10) of the hollow cylindrical joint receptacle (7) tapers in a wedge shape from the outer side (11) of the profile section (6) towards the inner side (19) of the profile section (6).

6. The multi-point guide arm according to any one of claims 1 to 5, characterized in that: The outer diameter of the hollow cylindrical joint receptacle (7) is larger than the smallest possible envelope circle (18) surrounding the at least one pair of profile sections (6) viewed in cross section.

7. The multi-point guide arm according to any one of claims 1 to 5, characterized in that: In the region of the fillet weld (9), the wall thickness of the hollow cylindrical joint receptacle (7) corresponds essentially to the sheet metal thickness (17) of the profile section (6), i.e., the distance between the outer side (11) and the correspondingly assigned inner side (19) of the profile section (6).

8. The multi-point guide arm according to any one of claims 1 to 5, characterized in that: The joint axis (15) of the hollow cylindrical joint receptacle (7) extends at least substantially perpendicularly to the longitudinal sides of the profile section (6).

9. The multi-point guide arm according to any one of claims 1 to 5, characterized in that: The multi-point guide arm is configured as a two-point guide arm (4) for guiding a rigid shaft.

10. The multi-point guide arm according to claim 9, characterized in that: The two-point guide arm (4) is a torsion bar.

11. The multi-point guide arm (3) according to any one of claims 1 to 5, characterized in that: The multi-point guide arm is configured as a three-point guide arm (3) for guiding a rigid shaft.

12. The multi-point guide arm according to any one of claims 1 to 5, characterized in that: The inner part (24) of the rubber-metal joint (12) is at least partially accommodated in the hollow-cylindrical joint receptacle (7).

13. The multi-point guide arm according to claim 12, characterized in that: The inner part (24) of the rubber-metal joint (12) has a spherical joint area (27) to enable universal movement.

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