EP3833558A1

EP3833558A1 - Multi-point link for an undercarriage of a motor vehicle

Info

Publication number: EP3833558A1
Application number: EP19755807.5A
Authority: EP
Inventors: Andre Stieglitz; Ingolf Müller
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2018-08-08
Filing date: 2019-07-10
Publication date: 2021-06-16
Also published as: WO2020030370A1; CN112601670A; US20210291603A1; US11298997B2; DE102018213321A1

Abstract

The invention relates to a multi-point link (20) for an undercarriage of a motor vehicle. The multi-point link (20) comprises at least one profile portion (21) having two bearing regions (22) arranged at opposite ends of the profile portion (21), the two bearing regions (22) being connected to one another by the profile portion (21). The multi-point link (20) is characterised in that an outer peripheral surface (25) of the profile portion (21), in order to increase the rigidity of the multi-point link (20), is provided with at least one reinforcement element (24), the reinforcement element (24) being connected integrally to the outer peripheral surface (25) of the profile portion (21).

Description

Multi-point link for a chassis of a motor vehicle

The invention relates to a multi-point link for a chassis of a motor vehicle according to the preamble of claim 1.

Multi-point links for the chassis of motor vehicles, in particular commercial vehicles, are known from the prior art. For example, axle suspensions for rigid axles of commercial vehicle chassis can have two two-point links designed as axle struts for guiding the rigid axle in a lower link plane. In an upper link level, chassis of commercial vehicles can have a three-point link or alternatively a four-point link. Axle struts usually have two end bearing areas which are connected to one another by a straight profile section. The straight profile section can have an open, for example H-shaped, cross section. When a straight two-point link is loaded with a compressive force acting in its longitudinal direction, there is a risk of failure due to the straight profile section bending out perpendicular to the longitudinal direction. The longer the straight profile section is designed, the greater this risk. From the

DE 10 2016 200 609 A1 discloses a straight two-point link with two end bearing areas which are formed in one piece with a straight and at the same time open profile section. The profile section is bulged over its extension in the longitudinal direction, with the flatness extending in the longitudinal direction having a maximum in the middle of the profile section where the danger of the profile section buckling is greatest. With such a load-oriented design of the two-point link, a small mass can be achieved.

The object of the invention is to provide an alternative design of a multi-point link with at least one profile section, in which the multi-point link also has a low component mass due to a load-oriented design of its profile section. This object is achieved according to the present invention by a generic multi-point link, which additionally has the characterizing features of claim 1.

Preferred embodiments and developments are the subject of the subclaims and the following description.

The invention accordingly provides a multi-point link for a chassis of a motor vehicle. The multi-point link has at least one profile section with two bearing areas arranged at opposite ends of the profile section. The two storage areas are connected to each other by the profile section. According to the invention, an outer circumferential surface of the profile section is provided with at least one stiffening element to increase the rigidity of the multipoint link, the stiffening element being integrally connected to the outer circumferential surface of the profile section.

The stiffening element enables the profile section to be stiffened in a load-oriented manner at the points where increased stresses can occur during ferry operation. It is therefore not necessary to design the cross section of the profile section over its entire longitudinal extent for a maximum stress which only occurs at one or more points on the profile section. In this way, over-dimensioning of the profile section can be avoided and at the same time the use of materials for the multi-point link can be minimized. In connection with the present invention, the stiffness is to be understood as the resistance of the professional lab cut to plastic deformation or to breakage, caused by a force or a torque, a bending moment or a torsional moment. The area of inertia or the section modulus of the profile section is increased by the at least one stiffening element in the area in which the stiffening element is integrally connected to the outer peripheral surface of the profile section. In this way, the profile section can be stiffened depending on the types of stresses and stress levels present in the course of its longitudinal extent. The profile section can be straight or curved over its longitudinal extent. If the profile section is designed as a straight profile section, the profile section extends in a columnar manner in particular over its entire longitudinal extent with a constant cross section. If the profile section is curved, it preferably has a constant radius of curvature. In particular, the profile section is solid, that is to say free of cavities. In particular, the profile section is designed as an open profile section. An open profile section in the sense of the present invention is to be understood as a profile section which, when viewed in cross section, has ribs, flanges or the like pointing outward from the profile. For example, a profile section with a double-T-shaped or an H-shaped or a double-E-shaped cross section is an open profile section. Alternatively, the profile section can also be designed as a closed profile section, without ribs, flanges or the like pointing to the outside of the profile and can have, for example, a rectangular or square full cross section. The profile section can also be designed as a hollow profile section and, when viewed in cross section, have one or more internal hollow chamber (s). The profile section and the at least one stiffening element can consist of the same material or of different materials.

The bearing areas are active, in particular rigid, connected to the profile section or integrally formed therewith and can introduce operating loads such as forces and / or moments into the profile section. In particular, the bearing areas each have an articulated receptacle. In particular, at least one storage area has an opening oriented perpendicular to a longitudinal direction of the profile section. The opening can be pot-shaped with an opening; for example for receiving a joint ball of a ball pin of a ball joint. Alternatively, the opening can also be designed as a through opening; for example with a cylindrical through opening for receiving a molecular joint, which is also referred to as a claw joint. In particular, the through opening has an unprocessed inner circumferential surface in the installed state. Alternatively, the storage area can have a through opening which, in its raw state, has an unprocessed inner circumferential surface and which, when installed, had a finished inner circumferential surface, in particular manufactured by machining. A steel bushing can be inserted into the through opening.

A profile section is to be understood in connection with the present invention in particular a section of an endless profile. If one side of the outer peripheral surface of the profile section, in particular a side facing a roadway in the installed state, is covered over its entire longitudinal extent by the stiffening element, in addition to the stiffening of the profile section, stone chip protection is provided for the profile section. If the outer circumferential surface of the tread section is completely covered by the stiffening element, the stiffening element also offers protection against small stones which are carried in a tire tread during ferry operation and are thrown onto the tread section from above. The stiffening element can be as long as the profile section or shorter than the profile section.

Due to the integral connection of the stiffening element to the outer circumferential surface of the profile section, the outer circumferential surface of the profile section can only be covered locally by the stiffening element. In this case, a contact surface of the stiffening element facing the outer peripheral surface of the profile section and separated from it only by an adhesive layer is smaller than the outer peripheral surface of the profile section. The outer peripheral surface of the profile section can also be completely covered by the stiffening element. In this case, the contact surface of the stiffening element is the same size as the outer peripheral surface of the profile section. In this latter case, depending on the specific design of the stiffening element, the main transmission of forces and / or moments can be carried out by the stiffening element alone. Alternatively, the outer peripheral surface of the profile section can also be covered locally or completely by several individual stiffening elements. The outer peripheral surface of a profile section which has no internal hollow chamber is formed from the entire outer surface of the profile section, which would be wetted if the profile section was immersed in a water bath, minus the surface of two end faces of the profile section. The stiffening element can extend in a longitudinal direction of the profile section over the entire length of the profile section or over part of the entire length. The stiffening element is preferably columnar with a constant cross section over its longitudinal extent. The stiffening element can be designed as an extruded profile, in particular an aluminum extruded profile. Alternatively, the stiffening element can also consist of a fiber composite plastic with reinforcing fibers, which can be in the form of woven fabrics, scrims or knitted fabrics and / or as continuous fibers in the form of an elongated filament bundle, which is also referred to as roving. According to a further alternative, the stiffening element can also be contoured, for example cambered, in its longitudinal direction. The stiffening element can have function-integrating elements. For example, the stiffening element can be designed as a die-cast component with an integrated holding arm for a cable or a hose. Function-integrating elements can be used, for example, to connect pipes or hoses for liquid transport or as a cable holder or as a holder for sensor or actuator elements or as a carrier for electronic components, for example for damage detection, or as a screw-on surface.

The multi-point link may be a straight two-point link, that is to say a rod-shaped link which is extended in one spatial direction and is suitable for transmitting forces and / or moments. Such a two-point link is primarily affected by tensile and / or compressive forces which are introduced into the profile section via the two bearing areas. The two-point link, which can be designed as an axle strut for guiding a rigid axle of a commercial vehicle, has in particular a profile section with a straight center line. In particular, this center line is congruent with a straight line through centers of the two storage areas. In such an arrangement, a load on the straight two-point link by a compressive force, the line of action of which is congruent with the center line, leads within the two-point link to a pure pressure and a pure buckling stress, which are not superimposed by a bending stress. Is the two-point link as an axle strut formed, can act on these, in particular caused by acceleration and deceleration processes, tensile, pressure and buckling stresses caused by rolling movements of a vehicle body, bending and torsional stresses. Alternatively, the multi-point link can also be an odd two-point link with a curved profile section, the profile section preferably having a constant radius of curvature.

The multi-point link can alternatively also be designed as a three-point link. Such a three-point link can be arranged in an upper link level of a chassis of a commercial vehicle and can be used to guide a rigid axle there. In addition, it is also conceivable to use such a three-point link as a wishbone for guiding a wheel. The three-point link preferably has two identical, straight and at the same time open profile sections that converge in a common bearing area, which can be part of a central joint of a rigid axle, for example. With such an arrangement, the two profile sections are subjected to bending, among other things, in ferry operation. The multi-point link can also be designed as a four-point link, for example with two parallel, straight and at the same time open profile sections, each with two bearing areas arranged at opposite ends of the two profile sections, or as a five-point link.

The multi-point link can be a one-piece multi-point link or a built multi-point link, ie a multi-point link assembled from several separately manufactured individual parts. This latter construction has the advantage that, for example, the at least one profile section can be made variable in length, as a result of which different variants of the multi-point link can be implemented according to a modular principle. With such a modular principle, the stiffening element can be adapted to the variable-length profile section by a stress-oriented geometric design of the stiffening element that is integrally connected to the outer circumferential surface of the profile section. It is particularly advantageous here that the bulky nature described at the outset is not, as in the prior art is known, integrally formed with the profile section, but can be placed on the outer peripheral surface of the profile section as needed. However, this advantage also applies to multi-point links in which the profile section is formed in one piece with the bearing areas. Here, a basic form of a multi-point link with a straight, columnar profile section can be prepared by placing different bulges in the form of differently designed stiffening elements for different uses with different types of loads and load levels. In the case of a multi-point link, the bearing areas can be designed as separate load introduction elements, in particular with an opening for receiving a joint.

Preferably, an adhesive layer is arranged between the profile section and the stiffening element, which materially connects the profile section and the stiffening element to one another. The stiffening element is glued to the outer peripheral surface of the profile section by the adhesive layer. The bond is in particular a full-area bond. The adhesive of the adhesive layer can be, for example, a two-component adhesive. Before the stiffening element is placed on the profile section, the adhesive can only be applied to the outer peripheral surface of the profile section or only to a contact surface of the stiffening element or to both surfaces. Alternatively, the adhesive can also be applied in the form of adhesive beads to the above-mentioned surfaces and then distributed by squeezing the stiffening element onto the profile section.

According to a preferred embodiment, at least one contour area of the profile section is encircled by the stiffening element in such a way that the profile section is cohesively and at the same time positively connected to the stiffening element in this contour area. In this way, in addition to the integral connection of the stiffening element to the outer peripheral surface of the profile section, a positive connection of the two aforementioned joining partners is additionally created. In particular, the contour regions of the profile section have partial surfaces of the outer peripheral surface of the profile section that extend parallel to one another. Under a positive connection in these connections to understand a connection in which forces are transmitted perpendicular to a contact plane through the shape of the components involved in the connection.

The profile section expediently has a cross section, with a web which extends in a vertical direction and a plurality of flanges which are spaced apart from one another and are connected to one another by the web, the flanges extending in a transverse direction oriented orthogonally to the vertical direction. In particular, the cross section of the profile section is formed symmetrically with respect to two planes of symmetry aligned orthogonally to one another. In particular, each flange is connected to any other flange via the web. The cross section of the profile section can be designed as an H-profile with four flanges, which extend like ribs away from the web. In particular, the cross section of the profile section is double E-shaped with a total of six flanges, of which three flanges each extend like ribs in directions offset by 180 degrees from the web. The aforementioned longitudinal direction of the profile section extends perpendicular to the vertical direction and at the same time perpendicular to the transverse direction. In particular, in an installed state, the flanges extend transversely in the chassis of a motor vehicle, in particular a commercial vehicle. In this way it is avoided that geometrical areas are created between individual flanges, in which undesired substances, such as spray water mixed with road salt, could collect.

A free end of a flange is preferably enclosed by the stiffening element. The surrounding border refers to a cross section of the profile section. The free end of the flange forms a contour region of the profile section, which is connected to the stiffening element in a cohesive and at the same time form-fitting manner, in particular by gluing. In the case of higher compressive forces acting in the longitudinal direction of the profile section, in particular the straight profile section, there is a risk, without the stiffening element, that free ends of the flanges bulge in some areas, which can lead to failure due to buckling of the profile section if the compressive forces increase further.

By enclosing the free end of the flange, this is terbunden and thereby the maximum possible pressure load of the profile section, in particular the straight profile section, increased. The free end of the flange is oriented in particular in the transverse direction. Alternatively, a flange as a whole can also be surrounded by the stiffening element. In this case, the flange forms a contour area of the profile section, which is connected to the stiffening element in a cohesive and, at the same time, form-fitting manner, in particular by gluing.

A plurality of flanges arranged parallel to one another are advantageously encompassed by the same stiffening element. In particular, the stiffening element has, depending on the number of flanges arranged parallel to one another, at least one coupling section. The coupling section rigidly connects two adjacent regions of the stiffening element, which enclose two adjacent flanges arranged parallel to one another, which further increases the stiffening effect of the stiffening element. In the case of three flanges arranged parallel to one another, the stiffening element has, for example, two coupling sections, through which the three regions of the stiffening element which surround the flanges are rigidly connected to one another. In particular, the coupling sections are formed in one piece with the stiffening element. In particular, the coupling sections extend in the vertical direction.

According to a further development of the invention, the stiffening element has wall sections of different thickness. In particular, the wall sections of different thickness are designed to be load-oriented, which makes a further contribution to minimizing the use of materials.

According to an alternative, the stiffening element is designed as a hollow profile with at least one hollow chamber. In this context, a hollow profile is to be understood as a profile which, when viewed in cross section, has at least one circumferentially closed cavity. By designing the stiffening element as a hollow profile, the area moment of inertia of the profile section provided with the stiffening element can be increased in a mass-neutral manner. The stiffening effect of the stiffening element increases in particular with increasing distance of the cavity from the cross-sectional center of the profile section.

The outer peripheral surface of the profile section is advantageously provided with a plurality of stiffening elements. In particular, the plurality of stiffening elements are arranged symmetrically to one another in any cross sections of the profile section. In particular, this symmetrical arrangement relates to a plane of symmetry which is spanned by the vertical direction and the longitudinal direction of the profile section. The plurality of stiffening elements can be an even or an odd number of stiffening elements. The multiple stiffening elements make it easy to stiffen the profile section in a stress-oriented manner.

Preferably, the plurality of stiffening elements completely surround the profile section at least at one point, in particular completely in contact. Completely enclosing the profile section has, in addition to the stiffening effect, the additional advantage that the profile section is particularly protected in the area enclosed by the several stiffening elements, for example against mechanical damage from stone chips and / or corrosive damage from road salt , Alternatively, the profile section can be completely or locally enclosed completely or by a single, annularly closed stiffening element. In this case, the one stiffening element can be circumferentially spaced from the outer peripheral surface of the profile section only by the adhesive layer.

The plurality of stiffening elements are expediently of identical design, at least in cross section. In this way, the plurality of stiffening elements can be separated inexpensively from the same rod material. The rod material can be an extruded profile or a pultruded profile. In particular, the plurality of stiffening elements are designed as identical identical parts. In addition to cost-effective production, the use of identical parts also has the advantage that component mix-ups are avoided. It is favorable if the several stiffening elements partially overlap. In this way, the stiffening effect of the plurality of stiffening elements can be increased further, in particular if the overlapping regions are connected to one another, for example by means of an adhesive. In particular, the overlapping regions of a plurality of stiffening elements lie directly against one another or are separated from one another by an adhesive layer. The overlapping areas in particular have a geometrically constant extension in the longitudinal direction of the profile section, as a result of which the stiffening elements with the overlapping areas can be produced in a simple manner from bar material.

The plurality of stiffening elements are preferably connected to one another in a circumferential manner by snap, snap or clip connections. Due to the snap, snap or clip connections, the stiffening elements can be glued to the outer peripheral surface of the profile section in a simple manner and without additional aids, such as, for example, tensioning devices. In particular, the plurality of stiffening elements are connected to one another in a circumferential manner in common overlap regions, in which the plurality of stiffening elements partially overlap, by means of the latching, snap-in or clip connections. The latching, snap or clip connections in particular have a geometrically constant extension in the longitudinal direction of the profile section, as a result of which the stiffening elements with the latching, snap or clip connections can be produced in a simple manner from bar material.

The profile section is preferably designed as a pultruded profile section made of a continuous fiber reinforced plastic. In this way, a particularly light multi-point link can be represented. In the present case, a pultruded profile section is to be understood as a profile section produced in a pultrusion process. The pultrusion process is a process for the cost-effective production of fiber-reinforced plastic profiles in a continuous process. In particular, the profile section has reinforcing fibers which are distributed over the entire profile cross section and which extend in the longitudinal direction of the profile section, as a result of which high rigidity and strength are brought about in this direction. Advantage- relatively large proportions of stretched fibers are arranged in the edge areas of the profile cross section and at the same time also extend in the longitudinal direction of the profile for the design of the profile section against buckling and / or bulges. In particular, all fibers are oriented in the longitudinal direction of the profile section. In a preferred embodiment, the pultruded profile section has a fiber volume content of approximately. 65 percent in order to achieve high stiffness in the longitudinal direction of the profile and at the same time high bending stiffness, as well as good power transmission of fibers in the profile section. In general, a fiber volume content between 50 percent and 75 percent is possible.

Both carbon fibers, glass fibers, aramid fibers or natural fibers, each of which is embedded in a plastic matrix, can be used in the profile section. The matrix system advantageously consists of a vinyl ester resin, since this can be processed well in the pultrusion process with very good chemical and mechanical properties. In addition, vinyl ester resin has good adhesion in combination with adhesives. Alternatively, an epoxy resin, a polyester resin, phenol resin or polyurethane resin can be used as the matrix material. The continuous fiber-reinforced plastic is, in particular, a fiber-plastic composite (FKV) which is formed from a plastic matrix with reinforcing fibers embedded therein, the reinforcing fibers being designed as continuous fibers. The fiber-plastic composite can be designed, for example, as a glass fiber reinforced plastic composite (GRP) or carbon fiber reinforced plastic composite (CFRP) or as an aramid fiber reinforced plastic composite (AFK). Alternatively, the profile section can also be designed as an extruded profile section, for example made of aluminum or an aluminum alloy.

It is advantageous if at least one bearing area has splines and the splines and an end section of the profile section engage in one another in a common connecting section and are at the same time glued to one another. With this type of connection, a relatively large adhesive surface can be realized, which accommodates the load-bearing capacity of the connection between the spline and the end section of the profile section. In particular, the spline has teeth that are at least essentially in one Extend the longitudinal direction of the profile section, in particular the straight profile section. In the area of the splines, the bearing area is not solid, but is reduced by the volume of gaps between the teeth. In addition to the teeth of the spline, only the associated end section of the profile section and adhesive is located in the connecting section. In particular, the connecting section is at least substantially free of air pockets. In particular, the end section of the profile section and the splines in the connection section engage at least essentially in a form-fitting manner.

In particular, the stiffness of the bearing area in the longitudinal direction of the profile section, in particular the straight profile section, is reduced. In the event of a tensile load on the profile section, in particular the straight profile section, tensile forces attempt to pull the end section of the profile section out of the spline in the longitudinal direction thereof. The reduction in stiffness of the bearing area in the area of the spline is due to the fact that the teeth of the spline are subjected to an elastic elongation in the longitudinal direction of the profile section, in particular the straight profile section, during tensile stress than is the case with a massive design of the bearing area in the area of the Splines would be the case. In particular, the splines are penetrated by lattice-like through grooves that extend perpendicularly to the longitudinal direction of the profile section and at the same time, at least partially, intersect. In particular, the teeth of the splines have a length that is essentially at least twice as large as a maximum width of the teeth, which provides a relatively high elastic expansion capacity of the splines in the longitudinal direction of the profile section both under tensile and compressive loads , The relatively thin teeth make it possible to reduce the stresses that occur in the adhesive layer, particularly when the profile section with its two bearing areas is subjected to tensile stress. This is also due to the fact that a relatively large number of teeth can achieve a relatively large connection area between the profile section and the respectively assigned storage area. In particular, the teeth are formed in one piece with the bearing area. In particular, the storage area is designed as a separate load introduction element. In particular, the teeth of the spline have a rectangular or square full cross-section over their longitudinal extent in the longitudinal direction of the end section of the load introduction element. In particular, the through grooves at least partially have a straight course in the longitudinal direction of the profile section. This means that some through grooves can be straight and others cannot. In particular, the teeth of the splines delimit at least two through four longitudinal sides extending through grooves in the longitudinal direction of the profile section. In particular, the teeth can have two, three or four longitudinal sides extending in the longitudinal direction of the profile section on through-grooves. The wording, according to which the end section of the load introduction element is penetrated by through-grooves, which extend perpendicular to the longitudinal direction of the connecting section and which at the same time intersect, at least in part, is intended to express that not every through-groove has to cut each of the remaining through-grooves ,

Advantageously, the through-grooves extending perpendicular to the longitudinal direction of the profile section have a constant width in a first direction and a varying width in a second direction extending perpendicular to the first direction. In particular, all through grooves that extend perpendicular to the longitudinal direction of the connecting section in the same direction are of the same design; thus have a constant or a variable width. In particular, the through grooves of constant width have a machined, preferably machined, in particular milled, surface. In particular, the through grooves with varying width have an unprocessed, in particular extruded, surface, as a result of which no machining costs are incurred. In particular, the through grooves with varying widths in the area of tooth bases and / or in the area of free ends of the teeth which face the profile section have an increased width.

In particular, the free ends of the teeth facing the profile section perpendicular to the longitudinal direction of the profile section have a minimal cross-sectional area. che on. This means that teeth of the splines, based on their course in the longitudinal direction of the profile section, have the smallest cross-sectional area at their free ends. As a result, the teeth have an additionally reduced rigidity in the longitudinal direction of the profile section at their free ends. In particular, the free ends of the teeth facing the profile section perpendicular to the longitudinal direction of the profile section are at a greater distance from one another at least in one direction of extension than is the case in at least one other area in the longitudinal direction of the profile section. This is due in particular to the fact that the through grooves of varying width have an increased width in the region of the free ends of the teeth. In particular, the adhesive, by means of which the splines are connected to the end section of the profile section, at least partially has an increased layer thickness in the region of the free ends of the teeth. As a result of the increased adhesive layer thickness, tensions in the adhesive layer can be locally reduced and distributed more evenly over the entire connecting section.

In particular, the teeth of the splines on teeth feet, at which the teeth merge into solid material of the bearing area, are at least partially tapered to further reduce the rigidity of the splines in the longitudinal direction of the profile section. In particular, tooth feet are tapered on their long sides, which border on through grooves of variable width. Since the profile section has a constant cross section over its longitudinal extent, an at least partially thickened adhesive layer results in the region of the tooth feet. In particular, widened interdental spaces in the area of the tooth feet, which result from the tapered tooth feet, are filled with adhesive. As a result of the increased adhesive layer thickness, local stresses in the adhesive layer are reduced and distributed more evenly over the entire connecting section.

In particular, at least one tooth of the spline is continuously tapered over its longitudinal extent towards the profile section. This is to be understood in such a way that the at least one tooth on its tooth base is a maximum Cross-sectional area that continuously decreases towards its free end in order to finally have a minimum at its free end. Thus, the at least one tooth perpendicular to the longitudinal direction of the profile section also has a stiffness that is continuously reduced toward its free end

Longitudinal direction of the common connecting section. The continuous tapering of the at least one tooth also contributes to a continuous transition of the stiffness conditions in the longitudinal direction of the profile section. In particular, the at least one tooth that tapers continuously toward the profile section is a canine tooth with two longitudinal sides that extend in the longitudinal direction of the profile section and that adjoin through grooves.

In particular, the bearing area, in particular the load introduction element, is designed as a profile piece, in particular an extruded profile piece, with unprocessed outer circumferential surfaces and / or inner circumferential surfaces that extend in a longitudinal direction of the profile. This has the advantage that relatively inexpensive bar material can be used as the starting material for the storage area. As an alternative to the extruded profile piece, a cold drawn or rolled profile piece is also possible, for example. In this context, the outer circumferential surfaces of the profile piece can be all surfaces that are wetted when the profile piece is completely immersed in a water bath, with any existing cavities being sealed beforehand. Inner circumferential surfaces are, if there are cavities extending in the longitudinal direction of the profile piece, the remaining surfaces. In the context of the present invention, a profile piece is to be understood as a piece of an endless profile. In particular, the profile piece has a constant cross-sectional geometry over its longitudinal extent.

The profile section can be inserted into the spline in its longitudinal direction up to the stop or can be spaced from this maximum position. The splines are particularly advantageous for tensile and / or compressive loads; but also favorable for torsion and / or bending stress. In particular, the length of the connecting section essentially corresponds to an external dimension of the cross section of the profile section. This gives the connecting section a relatively long length. This is particularly effective when the profile section with its two bearing areas or load introduction elements at higher temperatures if the adhesive softens somewhat under the influence of temperature and thereby becomes more elastic. In this case, the adhesive connection is also stressed in the area of a tooth base when the profile section and the two bearing areas are subjected to tensile stress. This is due to the fact that the adhesive has a lower strength and rigidity at higher temperatures, as a result of which tensile stresses are shifted in the direction of the tooth feet.

The relatively long length of the connection section thus represents a resilience reserve at relatively high ambient temperatures. A significantly longer length of the connection section no longer significantly increases the load-bearing capacity of the connection between the storage area and the profile section. A significantly shorter length of the connecting section leads to a reduction in the load-bearing capacity. The formulation that the splines and the end section of the profile section “at least essentially” interlock positively with one another is intended to express that the two end regions do not lie directly against one another - at least not over the full area, but are at a slight distance from one another, whereby this slight distance is filled up by an adhesive, in particular distributed over a voltage area. The glued plug connection has in particular an epoxy adhesive. Alternatively, other adhesives, such as methyl methacrylate adhesives, can also be used.

As already stated, the spline is particularly advantageous in connection with the profile section, because by gluing the teeth of the spline to the outer peripheral surfaces of the end section of the profile section and, if appropriate, also to the inner peripheral surfaces of hollow chambers (s) of the profile section, a relatively large adhesive surface can be achieved , The spline is also advantageous in the manufacture of the multi-point link, because excess glue can be easily removed through the through grooves. When the end section of the profile section is pushed into the spline, air is displaced from the through grooves. This displaced air can also escape through the through-grooves without any problems, causing air pockets in the common connecting section of profile section and load introduction element are at least largely avoided.

In addition to the end section of the profile section, at least one stiffening element preferably also engages in the splines within the connecting section. In particular, a part of the stiffening element or stiffening elements located within the splines is glued in the area of the connecting section to the bearing area or load introduction element. In this embodiment, the stiffening element (s) can extend over the entire length of the profile section. Alternatively, the stiffening elements can engage in the connecting sections and at the same time extend from these by 5 to 35 millimeters, preferably 10 to 30 millimeters. In this way, at the point at which the profile section and the stiffening element emerge from the connection section, favorable stress conditions can be achieved for the joining partners involved, in particular if the splines and the stiffening element are made of aluminum and the profile section is made of continuous-fiber-reinforced plastic are formed.

If the entire outer circumferential surface of the profile section is enclosed by stiffening elements that are integrally connected to it, the profile section can be designed as a foam core, in particular if the individual stiffening elements overlap circumferentially. In this case, the stiffening elements themselves generate sufficient buckling rigidity due to a high moment of inertia or moment of resistance. An embodiment in which, in addition to the end section of the profile section, a stiffening element or a plurality of stiffening elements in the connecting section also engage in the splines can be particularly advantageous if the load introduction element is designed as a section of an extruded profile and extruded through grooves having. Since extruded through grooves have to have a minimum width due to the process, a profile section made of aluminum with wall thicknesses that fill the extruded through grooves is usually oversized and thus heavier than necessary. However, the profile section consists of an endless fiber-reinforced plastic and the stiffening element consists of an aluminum Umprofil, a non-oversized version can be represented, in which the end section of the profile section and the stiffening element, lying one above the other, fill the extruded through grooves of the splines.

It is advantageous if both bearing areas each have splines and the outer circumferential surface of the profile section between the two splines is completely covered by the at least one stiffening element. In particular, two stiffening elements extend continuously between the two splines, which together at least substantially circumferentially enclose the part of the profile section lying between the two splines. This provides effective stone chip protection, especially if the two stiffening elements are made of aluminum. If the profile section is made of continuous fiber-reinforced plastic and the at least one stiffening element is made of aluminum, it is also possible to easily identify possible damage to the multi-point link by external influences. Such damage can be caused, for example, by placing a jack on the profile section of an axle strut and can be recognized by traces of deformation on the stiffening element made of aluminum.

In the following, the invention will be explained in more detail with reference to drawings which only show exemplary embodiments, the same reference numerals referring to the same, similar or functionally identical components or elements. It shows:

Figure 1 is a perspective view of a chassis arrangement according to the prior art.

2 shows a perspective view of a multi-point link according to a first embodiment of the invention;

3 shows a sectional view of the multi-point link according to FIG. 2 according to the section A - A given there; 4 shows a sectional view of the chassis control arm according to FIG. 2 in accordance with the section course BB indicated there;

5 shows a perspective view of a multi-point link according to a second embodiment of the invention;

6 shows a perspective illustration of a load introduction element of the multi-point link according to FIG. 5;

Figure 7 is a perspective view of a multi-point link according to a third embodiment of the invention.

8 is a perspective view of a profile section of a multi-point link according to a fourth embodiment of the invention;

9 is a perspective view of part of a multi-point link according to a fifth embodiment of the invention;

10 is a sectional view of a stiffening element according to an alternative embodiment;

Figure 1 1 in a sectional view of a stiffening element according to a further alternative embodiment.

12 shows a sectional illustration of stiffening elements according to a further alternative embodiment;

13 shows a cross-sectional view of stiffening elements according to a further alternative embodiment;

14 is a perspective view of a multi-point link according to a sixth embodiment of the invention and 15 is a perspective view of a multi-point link according to a seventh embodiment of the invention.

1 shows a part of a chassis 1 which is part of a motor vehicle, in the present case a commercial vehicle 2, the chassis 1 having two axle struts 3 arranged in a lower link plane. The two axle struts 3 are each connected at one end by a molecular joint to a vehicle axle designed as a rigid axle 5. At the other end, the axle struts 3 are each indirectly connected to a vehicle frame 6, also by means of a molecular joint. In addition to the two axle struts 3, the rigid axle 5 is guided by a one-piece four-point link 7, which is arranged in an upper link level and is essentially X-shaped. The four-point link 7 combines the functions of a three-point link and a separate roll stabilizer in one component. The four-point link 7 is connected in a frame-side bearing area 4 to the vehicle frame 6 by two molecular joints and in an axle-side bearing area 10 by two molecular joints to the rigid axle 5. Two of the total of four molecular joints are covered by a side member of the vehicle frame 6. As already indicated, the four-point link 7 could be replaced by a three-point link if the undercarriage 1 additionally had a roll stabilizer.

FIG. 2 shows a multi-point link 20 for a chassis of a motor vehicle, wherein the multi-point link 20 is designed as a straight two-point link. The two-point link 20 is a built axle strut. The two-point link 20 has a straight and at the same time open profile section 21 with two bearing areas 22 arranged at opposite ends of the profile section 21. The two bearing areas 22 each have an opening 23 for receiving a molecular joint (not shown). Furthermore, the two bearing areas 22 are designed as separate load introduction elements, which are each glued to the profile section 21. The two bearing areas 22 are connected to one another by the straight and at the same time open profile section 21, which extends in a longitudinal direction x. To increase the rigidity of the two-point link 20, there are two Stiffening elements 24 glued to an outer peripheral surface 25 of the profile section 21.

3 that the profile section 21, when viewed in cross section, has a web 26 extending in a vertical direction z and a plurality of flanges 27 spaced parallel to one another and connected by the web 26. The flanges 27 extend in a transverse direction y oriented orthogonally to the vertical direction z and each have a free end 28 which extends away from the web 26. Specifically, the cross section of the profile section 21 is double-E-shaped with a total of six flanges 27, of which three flanges 27 each extend like ribs in directions offset by 180 degrees from the web 26. The straight and at the same time open profile section 21 is designed as a pultruded profile section 21 made of an endless fiber reinforced plastic and extends over its entire longitudinal extent in the longitudinal direction x continuously with a constant cross section.

FIG. 4 shows that between the profile section 21 and the two stiffening elements 24 there is in each case an adhesive layer 29 applied over the entire surface, which connects the profile section 21 and the two stiffening elements 24 to one another in a cohesive manner. It can also be seen that not only the free ends 28 of the flanges 27, but also the complete flanges 27 are enclosed by the two stiffening elements 24. As a result, a plurality of contour regions of the profile section 21, namely both the free ends 28 of the flanges 27 and the flanges 27 themselves, are encompassed by the stiffening element 24 in such a way that the profile section 21 in these contour regions is cohesive and at the same time form-fitting with the stiffening element 24 is connected. In this case, three flanges 27, which are arranged parallel to one another and each extend in the same direction away from the web 26, are surrounded by the same stiffening element 24. For this purpose, the two stiffening elements 24, which are identical parts, each have two coupling sections 30. Each of the two coupling sections 30 rigidly connects two adjacent regions of the stiffening element 24, which enclose two adjacent flanges 27 arranged parallel to one another. A two-point link 20 shown in FIG. 5 with a straight and at the same time open profile section 21 has a total of four stiffening elements 24, each of which is glued over the entire surface to an outer peripheral surface 25 of the profile section 21. The profile section 21 is almost completely enclosed by two of the four stiffening elements 24 at two points spaced apart in the longitudinal direction x of the profile section 21. The two-point link 20, which is an axle strut, has two bearing regions 22 arranged at opposite ends of the profile section 21, which are not formed in one piece with the profile section 21, but are present as separate load introduction elements. The two load introduction elements 22 each have a spline 31. The two splines 31 mutually engage one another with an associated end section 32 of the profile section 21 in a common connection section 33. The two splines 31 are each glued to one of the two end sections 32 of the profile section 21.

In FIG. 6 it can be seen that the splines 31 of the load introduction element 22 are penetrated by grid-like through grooves 34 which extend perpendicularly to the longitudinal direction x of the profile section 21 and at the same time partially intersect. Thus, the load introduction element 22 is not solid in the area of the spline 31, but has a volume reduced by the volume of the through grooves 34. Due to the grid-like arrangement of the through grooves 34, the spline 31 has teeth 35 with a rectangular cross-section, which extend in the longitudinal direction x of the profile section 21. The load introduction element 21 consists of an aluminum alloy and is designed as a section of an extruded profile. The through grooves 34, which extend in an extrusion direction running in the transverse direction y, are part of the extrusion profile and are installed without further reworking. The teeth 35 of the spline 31 are tapered on the tooth feet on which the teeth 35 merge into solid material of the load introduction element 22 to reduce the longitudinal rigidity of the spline 31. Also to reduce the longitudinal stiffness, ie the stiffness in the longitudinal direction x of the profile section 21, sen the free, the profile section 21 facing ends of the teeth 35 perpendicular to the longitudinal direction x of the profile section 21 to a minimum cross-sectional area.

FIG. 7 shows a two-point link 20 in which two bearing areas 22, which are designed as separate load introduction elements, each have a spline 31. An outer peripheral surface 25 of a profile section 21, which connects the two load introduction elements 22 to one another, is completely covered between the two splines 31 by two stiffening elements 24.

8 shows a profile section 21 for a multi-point link 20 in which an outer peripheral surface 25 of the straight and at the same time open profile section 21 is completely covered by a single stiffening element 24. In this case, the stiffening element 24 surrounds the profile section 21 in the manner of a sheet metal sleeve that lies completely against it. For the purposes of the present invention, when viewed in cross section, the open profile section 21 has six ribs 27 pointing outward like a rib and two internal hollow chambers.

9 shows one half of a two-point link 20, in which, in addition to an end section 32 of a profile section 21, a stiffening element 24 within a connecting section 33 engages in a spline 31 of a bearing area 22, which is designed as a load introduction element. Here, a part of the stiffening element 24 located within the spline 31 is glued to the load introduction element 22 in the region of a connecting section 33. The stiffening element 24 engages essentially up to the stop in the spline 31 and at the same time extends 20 millimeters out of this in the direction of a second load introduction element 22, not shown.

A stiffening element 24 shown in FIG. 10 has three solid ribs 36 with free ends pointing towards the outside of the profile in order to increase a moment of inertia or a section modulus of a profile section 21, not shown. Three recesses 39 extending in the transverse direction y serve to enclose flanges 27. The inner circumferential surfaces of the recesses 39 form contact surfaces 40 which, in the assembled state of the multipoint steering core 20 face an outer peripheral surface 25 of a profile section 21 and are spaced therefrom only by an adhesive layer 29. The recesses 39 have wall sections 38 which extend in the transverse direction y and which are thinner than two coupling sections 30 which extend in the vertical direction z. FIG. 11 shows a stiffening element 24, which differs from the stiffening element 24 shown in FIG. 10 in that it is designed as a hollow profile with two hollow chambers 37.

12 shows an arrangement of two stiffening elements 24, which are designed as identical identical parts and enclose a profile section 21, not shown. The two stiffening elements 24 are each connected to one another by an adhesive 43 in two common overlap regions 41 in which the two stiffening elements 24 overlap. In this way, the two stiffening elements 24 act like a hollow profile. 13 shows two stiffening elements 24, which are likewise designed as identical identical parts and enclose a profile section 21, not shown. The two stiffening elements 24 are connected to one another by two latching connections 42.

14 shows a multi-point link 20 which is designed as a built three-point link. The three-point link 20 has two identical, straight and at the same time open profile sections 21, which are designed as pultruded profile sections 21 made of an endless fiber reinforced plastic. The profile sections 21 converge in a common bearing area 22 which is designed as a separate load introduction element and at the same time is part of a central joint of a rigid axle. In the sense of the present invention, this is to be understood in such a way that each of the two profile sections 21 has at this point a storage area 22 which coincides with the respective other storage area 22. At free ends facing away from the common bearing area 22, the profile sections 21 each have a bearing area 22 which is designed as a separate load introduction element and has a molecular joint. All load introduction elements 22 have splines 31 which are aligned with the associated ends of the profile sections 21. Since the profile sections 21 of the three-point link 20 in the ferry operation ter are subjected to bending, the two profile sections 21 each have a stiffening element 24 approximately in the center.

A multi-point link 20 shown in FIG. 15 is designed as a four-point link which has two profile sections 21 spaced apart from one another and which are fixedly connected to one another by a coupling element 44. Each profile section 21 is encircled on three sides by a stiffening element 24 in a central region of its longitudinal extent and glued to it. On the fourth circumferential side of the profile sections 21, these are each connected to the coupling element 44. Each stiffening element 24 has two tabs spaced parallel to one another, the four tabs meeting in the middle between the two profile sections 21 in pairs. The tabs are thus U-shaped when viewed in cross section. The tabs, which are glued to the entire surface of the coupling element 44 facing away from one another, represent function-integrating elements of the stiffening elements 24. The tabs serve to reinforce the firm connection between the profile sections 21 and the coupling element 44. A bearing area 22 with a molecular joint is arranged at each end of the two profile sections 21 of the four-point link 20.

Reference symbol chassis

Motor vehicle, commercial vehicle

Oh, right there

frame-side storage area

Vehicle axle, rigid axle

vehicle frame

Four-point link

multi-point link, two-point link, three-point link, four-point link section section

Storage area, load transfer element

opening

stiffener

Outer peripheral surface of the profile section

web

flange

free end of the flange

adhesive layer

coupling section

splines

end

connecting portion

through groove

Tooth of the splines

rib

hollow

wall section

recess

contact area

overlap area 42 snap-in connection

43 bonding

44 coupling element x longitudinal direction y transverse direction z vertical direction

Claims

claims

1 . Multi-point link (20) for a chassis of a motor vehicle, the multi-point link (20) having at least one profile section (21) with two bearing areas (22) arranged on opposite ends of the profile section (21), the two bearing areas (22) by the professional Lab Cut (21) are connected to each other, characterized in that an outer peripheral surface (25) of the profile section (21), to increase the rigidity of the multi-point link (20), is provided with at least one stiffening element (24), the stiffening element (24 ) is integrally connected to the outer peripheral surface (25) of the profile section (21).

2. Multi-point link (20) according to claim 1, characterized in that between the profile section (21) and the stiffening element (24) an adhesive layer (29) is arranged, the profile section (21) and the stiffening element (24) integrally with each other combines.

3. Multi-point link (20) according to claim 1 or 2, characterized in that at least one contour area (27, 28) of the profile section (21) is encircled by the stiffening element (24) such that the profile section (21) in it Contour area (27, 28) is integrally and at the same time positively connected to the stiffening element (24).

4. Multi-point link (20) according to any one of the preceding claims, characterized in that the profile section (21) has a cross section, with a web (26) extending in a vertical direction (z) and several spaced apart and parallel to one another the web (26) interconnected flanges (27), the flanges (27) extending in a transverse direction (y) oriented orthogonally to the vertical direction (z).

5. Multi-point link (20) according to claim 4, characterized in that at least one free end (28) of a flange (27) is surrounded by the stiffening element (24).

6. Multi-point link (20) according to claim 4 or 5, characterized in that a plurality of flanges (27) arranged parallel to one another are surrounded by the same stiffening element (24).

7. Multi-point link (20) according to one of the preceding claims, characterized in that the stiffening element (24) has wall sections (30, 38) of different thickness.

8. Multi-point link (20) according to any one of the preceding claims, characterized in that the stiffening element (24) is designed as a hollow profile with at least one hollow chamber (37).

9. Multi-point link (20) according to one of the preceding claims, characterized in that the outer peripheral surface (25) of the profile section (21) is provided with several stiffening elements (24).

10. Multi-point link (20) according to claim 9, characterized in that the several stiffening elements (24) surround the profile section (21) at least at one point completely, in particular completely.

1 1. Multi-point link (20) according to claim 9 or 10, characterized in that the plurality of stiffening elements (24) are identical, at least in cross section.

12. Multi-point link (20) according to one of claims 9 to 1 1, characterized in that the several stiffening elements (24) partially overlap.

13. Multi-point link (20) according to one of claims 9 to 12, characterized in that the plurality of stiffening elements (24) are circumferentially connected to one another by snap, snap or clip connections (42).

14. Multi-point link (20) according to any one of the preceding claims, characterized in that the profile section (21) is designed as a pultruded profile section (21) made of an endless fiber-reinforced plastic.

15. Multi-point link (20) according to one of the preceding claims, characterized in that at least one bearing area (22) has a spline (31) and the spline (22) and an end section (32) of the professional lab section (21 ) intermesh in a common connection section (33) and at the same time are glued to one another.

16. Multi-point link (20) according to claim 1 5, characterized in that in addition to the end section (32) of the profile section (21) also engages at least one stiffening element (24) within the connecting section (33) in the splines (22).

17. Multi-point link (20) according to claim 1 5, characterized in that both bearing areas (22) each have a spline (22) and that the outer peripheral surface (25) of the profile section (21) between the two splines (22) is completely covered by the at least one stiffening element (24).