WO2022073813A1

WO2022073813A1 - Multi-point link for the undercarriage of a vehicle

Info

Publication number: WO2022073813A1
Application number: PCT/EP2021/076735
Authority: WO
Inventors: Andre Stieglitz; Paul Niemöller; Frank Jung; Ingolf Müller; Christoph Hoffmeister; Patrick Schiebel; Michael Petrich
Original assignee: Zf Friedrichshafen Ag
Priority date: 2020-10-06
Filing date: 2021-09-29
Publication date: 2022-04-14
Also published as: DE102020212625A1

Abstract

The invention relates to a multi-point link (10) for the undercarriage of a vehicle, comprising a body (11), which has at least two load-application regions (13) that are connected together by a connecting section (14). The body (11), which is produced by means of an additive manufacturing method and which consists of plastic, has an outer lateral surface (12) which is closed over the entire circumference, and the interior of the body (11) has a structure (18) which is designed to be porous at least in some sections, wherein the porosity of the structure (18) is specified by the load to be received by the body (11).

Description

Multipoint link for a chassis of a vehicle

The invention relates to a multipoint link for a chassis of a vehicle according to the preamble of claim 1. Furthermore, the present invention relates to a method for producing a multipoint link for a chassis of a vehicle according to claim 17.

Multi-point links, such as wishbones, trailing arms, links of multi-link axles and the like, are used in practically all wheel suspensions and axles of motor and commercial vehicles and are used for the defined movable connection or to limit the degrees of freedom of movement of the wheel relative to the vehicle chassis. In addition to wheel control tasks, links often also serve to carry out body-supporting tasks by transferring spring and damper forces. After all, links are also part of the steering and roll suspension of a vehicle, where they then connect to a steering gear or stabilizer. Depending on the number of articulation points to be connected, a link can be realized as a 2-point link, as a 3-point link, as a 4-point link or as a 5-point link.

Classically, such multi-point links are made of metal in the form of cast iron, steel or aluminum, with the steel variant in particular being characterized by high strength, rigidity and ductility. However, a significant disadvantage of multipoint links made of metal is that they are very heavy, additional post-processing is usually necessary during production and measures against corrosion must also be taken. For this reason, multi-point links are now made of fiber composite materials in order to achieve a particularly light, load-bearing construction that is also easily adaptable in terms of geometry.

For example, DE 10 2015 104656 A1 discloses a multi-point link of the type mentioned at the outset, which comprises a body made of injection-molded plastic that has at least two load application areas that are connected to one another by a connecting structure. Draw multipoint links made of plastic compared to multi-point links made of metal due to a significantly lower dead weight. The production of such a multipoint link from a plastic is carried out in large series since the costs for the provision of injection molds are high.

Based on the prior art described above, it is now the object of the present invention to further develop a multipoint link and a method for producing a multipoint link of the type mentioned above, so that a multipoint link can also be produced economically in a small series.

This object is achieved from a technical point of view starting from the preamble of claim 1 in conjunction with its characterizing features. From a procedural point of view, the task is solved based on the preamble of independent claim 17 in conjunction with its characterizing features. The dependent claims following the independent claims 1 and 17 each reflect advantageous developments of the invention.

According to the invention, a multipoint link for a chassis of a vehicle is proposed, comprising a body that has at least two load application areas that are connected to one another by a connecting section, the body made of plastic, which is constructed by an additive manufacturing process, having a completely closed outer lateral surface , and that the body has an at least partially porous structure on the inside, the porosity of the structure being predetermined by the load to be absorbed by the body.

The structure of the body using the additive manufacturing process makes it possible to produce a multipoint link of the type mentioned at low cost in small numbers. Due to the completely closed outer lateral surface of the body, deposits and contamination of the multi-point link installed in a vehicle chassis can be avoided during operation.

The fact that the body has an at least partially porous structure in its interior, a particularly efficient use of material in the production achieved. The efficient use of materials is characterized in particular by a reduction in material costs and the production time when carrying out the additive manufacturing process. The material reduction thus also brings about a reduction in the occupancy time of the device for carrying out the additive manufacturing method. The additive manufacturing method can be, for example, the fused deposition modeling method (FDM method) or the poly-jet modeling (PJM method) or multi-jet modeling (MJM method). What is common to the additive manufacturing methods not listed exhaustively above is that the body is constructed by applying and curing a plastic, in particular a thermoplastic. The porosity of the structure is predetermined by the load to be absorbed by the body of the multipoint link. In particular, the porosity of the structure inside the body can vary in terms of expression and location, with the variation in the porosity of the structure being predetermined by the load to be absorbed by the body. This ensures that only as much material is used for the construction of the structure inside the body by the additive manufacturing process as is necessary for the respective load case to which the multipoint link is exposed during operation. The porosity of the structure represents the ratio of the void volume to the total volume of the body.

In particular, the structure of the body can be layered by an additive manufacturing process.

Thus, the porous structure in the interior of the body can be formed partially by building up a large number of structural elements which enclose cavities between themselves and/or the outer lateral surface. The volume of the cavities enclosed by the structural elements determines the porosity of the structure inside the body. The structural elements can have different dimensions. The structural elements can be flat elements, in particular ribs. Alternatively or additionally, the structural elements can be rod-shaped elements, in particular webs or struts. An essentially supporting structure is created by the structural elements. This is the aspect of profitability in the Production of the body by means of the additive manufacturing process is taken into account. At the same time, the lightweight effect is reinforced.

In particular, the structural elements can have a porosity, the porosity of the structural elements being predetermined by the load to be absorbed by the body. In addition to the structure having porosity, the structural elements that form the structure inside the body also have porosity. In this case, the porosity of the structural elements themselves is determined as a function of the load which is introduced into the connection section via the load introduction areas. Thus, the structure inside the body and the structural elements that form the structure can be designed to be completely porous. Within the cavities enclosed by the structural elements and/or the outer lateral surface, the structure therefore has a porosity that differs from that of the structural elements. This further minimizes the amount of material required to produce the body, without falling short of the required strength and rigidity requirements of the body.

In particular, the body can be made stiffer and stronger by varying the magnitude of the porosity along the main load directions. The internal structure of the body can - be made almost completely porous - with the exception of the outer surface. In this case, by varying the magnitude of the porosity of the internal structure and of the structural elements along the existing main load directions in the body, they can be made stiffer and stronger.

The body can preferably be divided into several load segments. By dividing the body into different load segments, the type and magnitude of the loads occurring in a respective load segment of the body can be taken into account when designing the internal structure. A load segment is defined as an area or portion of the body that is subjected to a specific type and/or magnitude of stress. Different load segments of the body differ from each other in terms of the nature and/or magnitude of the exposure. The body can be divided into at least two different load segments. The transition between the at least two load segments can be abrupt or smooth.

In particular, the porosity of the structure and/or structural elements may vary between different load segments. The porosity can vary depending on the type and/or magnitude of the loads occurring in a load segment. The porosity of the structural elements can also have the value zero, i.e. the structural elements consist of a solid material.

Furthermore, the porosity of structural elements within a load segment can be lower than the porosity of the respective structure filling the cavities in this load segment. This also serves to reduce the amount of material used in the manufacture of the body.

A first load segment can preferably lie in the respective load application area of the body. A low porosity of the internal structure of the body is required in the first load segment, which is in a load application area. The load introduced in the load introduction areas of the body can be distributed over a large area over a short distance over the cross section of the connecting section by a narrow branch due to the large number of porous structural elements and/or structural elements made of solid material. This avoids local stress peaks. Bending loads can be of at least minor importance in the load application areas due to an increased thickness of the body, i.e. a greater extension of the load application areas in the vertical direction than the connecting section.

Furthermore, a second load segment can be located in the area of at least one narrowing of the connecting section running in the vertical direction, the narrowing starting from one of the load introduction areas and forming a transition into an intermediate section of the connecting section located between the load introduction areas. A narrowing of the connecting section of the multipoint link may be necessary in order to do justice to the often limited space available in the area of the chassis. The waist means a section-by-section reduction in the expansion of the connecting section compared to the load introduction areas in the vertical direction. The waist adjoins the respective load application area and extends in sections in the longitudinal direction of the connecting section. In the one or more second load segments, ie the areas of the connecting section in which the waist is provided, the load is concentrated on a smaller cross-section than in the first load segment. The porosity of the structure and the structural elements in the respective second load segment should still be very low in order to be able to absorb the loads. Increased loads occur in particular in the tapered edge layer of the respective second load segment, which is why the edge layer should be designed with relatively thick walls.

Furthermore, a third load segment and a fourth load segment can be provided, with the fourth load segment being arranged between two third load segments. The third load segment serves to homogenize the transmitted force over the entire cross-sectional area of the connecting section, which adjoins the respective waist, i.e. the second load segment. In the third load segment, the bending components contained in the load are increasingly relevant. The fourth load segment experiences an increased tendency to buckle transverse to the longitudinal axis of the body as a result of a compressive load. The fourth load segment can therefore be secured against bending by the design of the structural elements in the shear panel. In particular, the fourth load segment of the connection section can have a higher porosity of the structure and/or of the structural elements than the first and second load segments close to the load introduction. A specifically adjusted variation of the porosity of the inner structure and/or the structural elements can be explicitly used here in order to obtain a body of the multipoint link that is adapted to the loads.

In particular, the porosity of the structure within a load segment can vary from the first load segment to the fourth load segment. in particular In particular, the porosity of the structure may increase or decrease within one of the load segments or relative to adjacent load segments. As a result, the structure and the structural elements of adjacent load segments can flow into one another in order to achieve a locally optimal and continuously changing mechanical behavior of the connection section or of the body.

Alternatively, the load segments may be separated from one another by transverse ribs running transversely of the body. The transverse ribs can be arranged oriented perpendicularly to the center plane in the body, i.e. the transverse ribs extend in the transverse and vertical direction.

The structural elements can preferably have an inclination in the longitudinal direction and/or transverse direction of the body. The longitudinal direction designates an extension running along a longitudinal axis of the body. The body has a longitudinal extension in the longitudinal direction. The transverse direction denotes an extension running perpendicularly to the longitudinal axis of the body, which spatially lies in one plane with the longitudinal direction. The body has a width dimension in the transverse direction. The vertical direction denotes an extension running perpendicularly to the longitudinal axis of the body, which extends perpendicularly to the plane of the longitudinal and transverse directions. The body has a vertical extent in the vertical direction, which is generally much more limited by the available space than the width of the body in the transverse direction. The inclined arrangement of the structural elements in areas subject to tensile or compressive forces can be combined with an internal structure that is primarily subject to shear stress. It is therefore advantageous to arrange or form structural elements with a preferred orientation in a +/-45° direction. Structural elements can preferably have a flattening angle as the distance from a central plane of the body to the areas subjected to tensile or compressive forces increases. The median plane of the body is to be understood as an imaginary plane extending longitudinally and transversely from the midpoint of the body. The midplane can also be physically configured as one or more structural elements that are extend continuously in the longitudinal and transverse directions. As a result, the structural elements can extend from the center plane or be divided by it.

Furthermore, some of the structural elements can have a course that is radially curved in sections. The structure elements following a curved path can run at a shallow angle near the outer lateral surface, while they enclose an angle of approximately 45° with a structural element running parallel to the outer lateral surface. In particular, the structural elements following a curved path can have a parabolic profile. Due to the curved course of the structural elements, the acting shear stress in the body can be represented. Furthermore, it is conceivable that the structural elements, which are arranged in particular in the third and fourth load segment, have a substantially S-shaped course in the vertical direction of the body. The structural elements have different angles to the longitudinal axis of the body over their course. The structural elements can particularly preferably have a tangent-continuous course, i.e. a course without edges or kinks.

Furthermore, at least the structural elements arranged in the first load segment can run essentially parallel to the center plane of the body. The course of the structural elements parallel to the central plane corresponds to the orientation of the forces that are introduced into the body in the load application areas. These are primarily compressive or tensile forces.

According to a preferred embodiment, the connecting section can have an extent in the longitudinal direction of the body that is greater than in the vertical direction of the body, the body having an outer contour that widens continuously in the longitudinal direction of the body, the maximum extent of which is in the center of the body. The outer contour of the connecting section, which widens continuously in the longitudinal direction of the body, creates a large axial area moment of inertia in order to be able to absorb the compressive forces that are introduced without the connecting section buckling or bulging. By widening the connection section in the transverse direction, starting from the load application areas towards the center of the body, the compressive forces absorbed in the load application areas are introduced into the connection section at an early stage and distributed substantially evenly in the transverse direction. In particular, at least the fourth load segment of the connection section can have a higher porosity than the areas close to the load introduction, since the load in the area of the fourth load segment is already introduced uniformly into the inner structure and is distributed over an increased width of the connection section in the transverse direction. Preferably, the multi-point link can be designed as a 2-point link.

Furthermore, the object set at the outset is solved by a method for producing a multipoint link for a chassis of a vehicle with the features of independent claim 17 .

According to claim 17, a method for producing a multipoint link for a chassis of a vehicle is proposed, comprising the implementation of an additive manufacturing method for constructing a body from a plastic, the body being constructed with at least two load application areas which are connected to one another by a connecting section , wherein the body is constructed with a completely closed outer lateral surface, and that the body is constructed on the inside with an at least partially porous structure, the porosity of the structure being predetermined by the load to be absorbed by the body. In particular, the porosity of the structure can be varied inside the body, the variation in the porosity of the structure being predetermined by the load to be carried by the body. The porosity, ie the location of cavities inside the body, is determined by the respective type and magnitude of the load that occurs. The layered construction of the body by the additive manufacturing process makes it possible to produce a multipoint link of the type mentioned at low cost in small quantities, which is adapted to the loads to be absorbed. This is favored by the fact that the porous design of the body results in a reduction in material and thus the production time is minimized. A thermoplastic material is preferably used. In this case, the structure can be formed by building up a large number of structural elements which enclose cavities between themselves and/or the outer lateral surface. The porosity of the body can be shaped by the volume of the cavities enclosed by the structural elements and the number and dimensioning of the structural elements. This takes into account the aspect of economy in the manufacture of the body using the additive manufacturing process. At the same time, the lightweight effect is reinforced. The structural elements can be manufactured with different wall thicknesses.

Furthermore, the structural elements can be made porous at least in sections, the porosity of the structural elements being predetermined by the load to be absorbed by the body.

The body can preferably be made stiffer and stronger by varying the magnitude of the porosity of the structure and the structural elements along the main load directions.

Particularly preferably, an additive manufacturing process can be used to build up the body in layers.

An advantageous embodiment of the invention, which is explained below, is shown in the drawings. It shows:

1 shows a schematic representation of a chassis according to the prior art in a partial view;

2 shows a schematic representation of a multipoint link according to the invention in an isometric view;

3 shows a schematic representation of the multipoint link according to the invention in a sectional view along the line AA according to FIG. 2 and a detailed view; and 4 shows a schematic representation of the multipoint link in a side view (A) and a top view (B).

1 shows a schematic representation of a chassis 1 of a vehicle, in particular a commercial vehicle, according to the prior art in a partial view. The chassis 1 comprises two longitudinal beams 2, a steerable axle 3 and a steering rod 4 extending in the longitudinal direction of the vehicle (not shown). A U-shaped roll stabilizer 5 is arranged on the steerable axle 3 . The roll stabilizer 5 is connected in an articulated manner to the respective longitudinal member 2 by a two-point link 7 assigned to the roll stabilizer 5 at the end (only one of which is shown in FIG. 1). The two-point link 7 has a load introduction area 8 at each end, at which the two-point link 7 is connected in an articulated manner to the roll stabilizer 5 or the longitudinal member 2 . The two-point links 7 arranged on the roll stabilizer 5 are designed here as so-called coupling rods. Also extending in the longitudinal direction of the vehicle is a leaf spring assembly 6 which is arranged below the side member 2 and parallel to the steering rod 4 . The two-point link 7 extends in the vertical direction between the leaf spring assembly 6 and the steering rod 4 . The installation space between the leaf spring assembly 6 and the steering rod 4 that is available transversely to the longitudinal direction of the vehicle is very limited. The two-point link 7 known from the prior art is made of a metallic material so that the two-point link 7 has the necessary rigidity to prevent a buckling or bulging of a connecting section 9 due to the compressive forces to be absorbed by the two-point link 7, which are caused by the oppositely arranged Load application areas 8 are initiated in the two-point link 7.

2 shows a schematic representation of a multipoint link 10 according to the invention in an isometric view. In the exemplary embodiment shown, the multi-point link 10 is designed as a two-point link and comprises a body 11 which has two load application areas 13 at the end which are connected by a connecting section 14 formed between the load application areas 13 are connected to each other. The body 11 is preferably symmetrical. The extension of the connecting portion 14 in the longitudinal direction x of the body 11 is greater than in its vertical direction z. The body 11 has a completely closed outer lateral surface 12 which is only interrupted in the load application areas 13 by a cylindrical recess 21 . The completely closed outer lateral surface 12 prevents foreign material from penetrating and depositing. A bearing mount 15 is arranged in the respective recess 21 . The respective bearing mount 15 is used to hold a joint or joint part--not shown. The respective joint can be designed as a ball joint or as an elastomer joint or as a part of the same.

Starting from the load application area 13 , the connecting section 14 has an outer contour that widens continuously in the longitudinal direction x of the body 11 , the maximum extent of which in the transverse direction y lies in the center of the body 11 . In the exemplary embodiment shown, the body 11 has an essentially elliptical outer contour. The outer contour of the body 11 can also be essentially diamond-shaped. In the load application areas 13, the connecting section 14 has a greater extension in the vertical direction z of the body 11 than an intermediate section 16 of the connecting section 14 located between the load application areas 13. A narrowing 17 forms in the transition from the respective load application area 13 to the intermediate section 16. The course of the reduction in the expansion of the body 11 in the vertical direction z or the waisting 17 essentially follows the shape of an ellipse, starting from the respective load application area 13 towards the intermediate section 16 . In particular, there is a reduction in the ratio of the Euler number, since this offers a particularly favorable introduction of force, i.e. an avoidance of stress peaks, in the intermediate section 16 of the connecting section 14.

In FIG. 2 the outer lateral surface 12 , which is completely closed per se, is shown open in an edge area of the intermediate section 16 , so that the inner structure of the body 11 can be seen in part. Inside, the body 11 has a structure 18 that is porous at least in sections. Furthermore, as Ribs executed structural elements 19 are provided, which can also be made at least partially porous. Alternatively or additionally, rod-shaped elements in the form of webs or struts can be provided as structural elements. The porous structure 18 inside the body 11 is partially formed by the structural elements 19 . The body 11 is produced by an additive manufacturing process. The body 11 is built up in layers in one direction from a plastic, in particular a thermoplastic.

The representation in Fig. 3 shows schematically the multipoint link 10 according to the invention in a sectional view along the line A-A according to Fig. 2 and a detailed view of the intermediate section 16. In the external load application areas 13, structural elements 20 designed as ribs extend essentially in the longitudinal direction x of the body 11 . The structural elements 20 are arranged essentially parallel to one another. Sections or layers with a porous structure 18, which connect the structural elements 20 to one another, are located between the structural elements 20 that run parallel and are spaced apart from one another. The porosity of the structure 18 varies within a respective section lying between two adjacent structure elements 20 . Furthermore, the arrangement of the bearing mount 15 can be seen, which is located within the recess 21 formed in the course of the manufacturing process. The integration of the bearing mount 15 takes place during the layered construction of the body 11. For this purpose, the bearing mount 15 is placed in the resulting load application areas 13 perpendicular to the direction of construction and is subsequently surrounded in layers by the structure 18 and the structural elements 20.

The structural elements 20 extending essentially in the longitudinal direction x have a changing course in the transition to the area of the waist 17 . Thus, the structural elements 20 can at least partially transition into a profile that is curved at the end. The structural elements 19 of the intermediate section 14 directly or indirectly adjoin the ends of the structural elements 20 . The structural elements 19 of the intermediate section 14 have a different course due to the loads to which the body 11 is exposed in this area. While in the load application areas 13 on the bearing mounts 15 in Substantial tensile and compressive forces are introduced, an increased tendency to buckling in the vertical direction z occurs in the intermediate section 14 with increasing distance from the load application areas 13 as a result of the compressive load. This area is secured against bending by the different design of the structural elements 19 in the shear panel. This requires the arrangement of structural elements 19 subjected to tensile or compressive loads, predominantly in the outer regions, ie towards the outer lateral surface 12, which are combined with an arrangement of structural elements 19 which is predominantly subjected to shear stress. In a central plane 22 of the body 11, an arrangement of the structural elements 19 with a preferred orientation in +/−45° direction is therefore advantageous, which has a flattening angle with increasing distance from the central plane 22 towards the structural elements 19 subjected to tensile or compressive loads . The center plane 22 of the body 11 is to be understood as an imaginary plane which extends in the longitudinal direction x and the transverse direction y, starting from the center point of the body 11 .

The detailed view according to FIG. 3 illustrates the internal structure of the body 11 with its porous structure 18 and the structural elements 19. Cavities 23 are enclosed by the outer lateral surface 12 and the ribs 19 which adjoin it. A porous structure 18 which fills the cavity 23 is formed in these cavities 23 during the layered construction of the body 11 . Structure 18 is formed from thin-walled sections bonded together to enclose cavities 25 . The cavities 25 are completely closed. The porosity of the structure 18 differs from the porosity of the structural elements 19 delimiting the cavity 23 . Cavities 24 are also formed between adjacent structural elements 19 . A porous structure 18 which fills the respective cavity 24 is also formed in these cavities 24 . The porosity of the structural elements 19, 20 in the exemplary embodiment shown has the value zero, ie the ribs 19, 20 consist of a solid material. The porosity of the structural elements 19, 20 can vary depending on the type and/or magnitude of the loads that occur, ie assume a value other than zero, which results in a saving in material. The course of the structural elements 19 which adjoin the respective outer lateral surface 12 or merge into it have an essentially S-shaped course in the vertical direction z of the body 11 . Toward the center plane 22 of the body 11, the structural elements 19 have a preferred orientation in a +/-45° direction. Overall, the structural elements 19 have different angles to the longitudinal axis or center plane 22 of the body 11 over their course, at least in the vertical direction. The structural elements 19 can particularly preferably have a tangent-continuous course, ie a course without edges or kinks. In the area of the center plane of the body 11, the arrangement of the structural elements 19 or the porous structure 18 with a preferred orientation of +/−45° to the center plane 22 is advantageous. The structural elements 19 have a flattening angle as the distance from the center plane 22 increases towards the outer jacket surfaces 12 subjected to tensile and compressive loads. This arrangement of the structural elements 19 and the porous structure 18 means that they are optimally aligned in accordance with the effective shear field.

The structure 18 has a porosity which is predetermined by the load to be carried by the body 11 . This is illustrated in the detailed view according to FIG. 3 in that the structure 18 within the cavities 23 and 24 in turn encloses cavities 25 of different sizes. The structural elements 19, 20 have a porosity which is also predetermined by the load to be absorbed by the body 11.

Fig. 4 shows a schematic representation of the multipoint link in a side view (A) and a top view (B). The body 11 is divided into several load segments 26,27,28,29. By dividing the body 11 into different load segments 26, 27, 28, 29, the type and magnitude of the loads occurring in a specific load segment 26, 27, 28, 29 of the body 11 can be taken into account when designing the inner structure 18. A load segment 26, 27, 28, 29 denotes an area or a section of the body 11 which is subjected to a specific type and/or magnitude of load. Different load segments 26, 27, 28, 29 of the body 11 differ from one another with regard to the type and/or magnitude of the load that occurs. The porosity of the structure 18 and/or the structural elements 19, 20 between the different load segments 26, 27, 28, 29 vary. The respective porosity can vary depending on the type and/or magnitude of the loads occurring in a load segment 26, 27, 28, 29. The porosity of the structural elements 19, 20 can also have the value zero, ie the ribs 19, 20 consist of a solid material. In particular, the porosity of the structural elements 19, 20 within a load segment 26, 27, 28, 29 can be lower than the porosity of the structure 18 filling the cavities 23, 24 in this load segment 26, 27, 28, 29.

A first load segment 26 lies in the respective load introduction area 13 of the body 11. In the load introduction areas 13, a low porosity of the inner structure 18 and/or the structural elements 20, i.e. a high density of the structure 18, is required. The tensile/compressive load introduced in the load introduction areas 14 of the body 11 in the case of a multipoint link 10 designed as a two-point link is thus spread very flatly over a very short distance through a narrow branch due to the large number of ribs 20 of low porosity and/or structural elements 20 made of solid material initiated a short way into the connecting section 14. This avoids local stress peaks. Bending loads can be negligible or at least of secondary importance in the load application areas 13 due to the increased thickness of the body 11, i.e. the greater extent of the load application areas 13 in the vertical direction z than the connecting section 14.

A second load segment 27 is located in the area of the waist 17 of the connecting section 14 running in the vertical direction z, the waist 17 starting from the respective load introduction area 13 and forming a transition into the intermediate section 16 of the connection section 14 located between the load introduction areas 13. The waist 17 means a reduction in sections of the expansion of the connecting section 14 compared to the load application areas 13 in the vertical direction z. The waist 17 connects to the respective load application area 13 and extends in sections in the longitudinal direction x of the connecting section 14. In the second load segments 27, the load is concentrated on a smaller cross section than in the first load segment 26. The porosity of the structure 18 and the structural elements 19, 20 in the respective second load segment 27 is therefore very low in order to be able to absorb the loads that are introduced. Increased loads occur in particular in the tapered edge layer of the outer lateral surface 12 of the respective second load segment 27, which is why the edge layer of the outer lateral surface 12 has relatively thick walls.

Furthermore, third load segments 28 and a fourth load segment 29 are provided, with the fourth load segment 29 being arranged between the two third load segments 28 . The third load segment 28 serves to homogenize the transmitted force over the entire cross-sectional area of the connecting section 14, which adjoins the respective waist 17, i.e. the second load segment 27. In the third load segment 28, bending components contained in the load are increasingly relevant. The fourth load segment 29 experiences an increased tendency to buckle transversely to the longitudinal axis of the body 11 as a result of a compressive load introduced in the first load segment 26 . The fourth load segment 29 is therefore secured against bending by the design of the structural elements 19 in the shear panel. In particular, the fourth load segment 29 of the connecting section 14 can have a higher porosity of the structure 18 and/or the structural elements 19 than the first load segments 26 and second load segments 27 close to the load introduction. A specifically adjusted variation of the porosity of the inner structure 18 and/or the structural elements 19 can be used explicitly in this case in order to obtain a body 11 of the multipoint link 10 which is adapted to the loads.

The porosity of the structure 18 increases from the first load segment 26 to the fourth load segment 29 . This allows the structure 18 and the structural elements 19, 20 of mutually adjacent load segments 26, 27, 28, 29 to merge smoothly into one another, in order to achieve locally optimal and continuously changing mechanical behavior of the connecting section 14 or of the body 11.

The load segments 26 , 27 , 28 , 29 can also be separated from one another by transverse ribs 30 running in the transverse direction y of the body 11 . The transverse ribs 30 extend perpendicular to the center plane 22. reference sign

landing gear

side members

axis

handlebar

roll stabilizer

leaf spring package

two-point link

load application area

connection section

multipoint handlebar

Body

outer surface

load application area

connection section

stock pick-up

intermediate section

sidecut

structure

structural element

recess

midplane

cavity

First load segment

Second load segment

Third load segment

Fourth load segment 30 transverse rib

Claims

patent claims

1. Multipoint link (10) for a chassis of a vehicle, comprising a body (11) which has at least two load application areas (13) which are connected to one another by a connecting section (14), characterized in that the constructed by an additive manufacturing process , a body (11) consisting of a plastic has a completely closed outer lateral surface (12), and that the body (11) has a structure (18) that is porous at least in sections on the inside, the porosity of the structure (18) being determined by the Body (11) to be absorbed load is predetermined.

2. Multipoint link (10) according to claim 1, characterized in that the structure (18) is partially formed by the construction of a plurality of structural elements (19, 20), which cavities (23, 24) between them and / or the outer surface ( 12) include.

3. Multipoint link (10) according to claim 2, characterized in that the ribs (19, 20) have a porosity, the porosity of the structural elements (19, 20) being predetermined by the load to be absorbed by the body (11).

4. Multipoint link (10) according to claim 1 or 3, characterized in that the body (11) is made stiffer and stronger by varying the magnitude of the porosity along the main load directions.

5. Multipoint link (10) according to any one of claims 1 to 4, characterized in that the body (11) is divided into a plurality of load segments (26, 27, 28, 29).

6. Multipoint link (10) according to claim 5, characterized in that the porosity of the structure (18) and/or the structural elements (19, 20) varies between different load segments (26, 27, 28, 29).

7. Multipoint link (10) according to claim 5 or 6, characterized in that the porosity of structural elements (19, 20) within a load segment (26, 27, 28, 29) is less than the porosity of the respective structure (18) in this load segment (26, 27, 28, 29).

8. Multi-point link (10) according to any one of claims 5 to 7, characterized in that a first load segment (26) is located in the respective load introduction region (13) of the body (11).

9. Multi-point link (10) according to claim 8, characterized in that a second load segment (27) in the region of at least one waist (17) of the connecting section (14) running in the vertical direction (z), the waist (17) of one of the load introduction areas (13) and forms a transition into an intermediate section (16) of the connecting section (14) located between the load introduction areas (13).

10. Multipoint link (10) according to claim 9, characterized in that a third load segment (28) and a fourth load segment (29) are provided, wherein the fourth load segment (29) is arranged between two third load segments (28).

11. Multipoint link (10) according to claim 10, characterized in that the porosity of the structure (18) varies within a load segment (26, 27, 28, 29) starting from the first load segment (26) towards the fourth load segment (29).

12. Multipoint link (10) according to one of claims 5 to 11, characterized in that the load segments (26, 27, 28, 29) are separated from one another by transverse ribs (30) running in the transverse direction (y) of the body (11).

13. Multipoint link (10) according to any one of claims 2 to 12, characterized in that the structural elements (19, 20) partially have an inclination in the longitudinal direction (x) and / or transverse direction (y) of the body (11).

14. Multipoint link (10) according to any one of claims 2 to 13, characterized in that the structural elements (19, 20) partially have a radially curved course in sections.

15. Multipoint link (10) according to any one of claims 2 to 14, characterized in that at least the in the first load segment (26) arranged structural elements (20) have a to the central plane (22) of the body (11) substantially parallel course.

16. Multipoint link (10) according to one of claims 1 to 15, characterized in that the connecting section (14) has an extension in the longitudinal direction (x) of the body (11) which is greater than in the vertical direction (z) of the body (11). and that the body (11) has an outer contour that widens continuously in the longitudinal direction (x) of the body (11), the maximum extent of which lies in the middle of the body (11).

17. Method for producing a multipoint link (10) for a chassis of a vehicle, comprising carrying out an additive manufacturing method for constructing a body (11) from a plastic, wherein the body (11) is constructed with at least two load application areas (13) which are connected to one another by a connecting section (14), the body (11) being constructed with a completely closed outer lateral surface (12), and that the body (11) is constructed on the inside with a structure (18) which is at least partially porous, wherein the porosity of the structure (18) is predetermined by the load to be absorbed by the body (11).

18. The method according to claim 17, characterized in that the structure (11) is formed by building up a plurality of structural elements (19, 20) which include cavities (23, 24) between themselves and/or the outer lateral surface (12).

19. The method according to claim 18, characterized in that the ribs (19, 20) are made porous at least in sections, the porosity of the structural elements (19, 20) being predetermined by the load to be absorbed by the body (11).

20. The method according to any one of claims 17 to 19, characterized in that the body (11) is made stiffer and stronger by varying the magnitude of the porosity along main load directions.

21. The method according to any one of claims 17 to 20, characterized in that an additive manufacturing process for building up the body (11) in layers is used.