Ball joint for a chassis

Abstract

A ball joint having a ball pin and a housing. The ball pin together with the ball is accommodated in the housing to move in a rotational and pivotal manner. The ball is at least partially surrounded by a structural component. The structural component is essentially formed from a fiber-plastic composite structure and at least partially forms the housing.

Claims

1. A ball joint comprising: a ball pin defining an axis, a housing defining an axis, the ball pin and the housing, when coaxially aligned, define a longitudinal axis of the ball joint, the ball pin together with a ball being accommodated within a hole in the housing such that the ball pin and the ball are rotatable and pivotable in the housing relative to the longitudinal axis of the ball joint, the ball being at least partially surrounded by a structural component, the structural component being formed primarily from a fiber-plastic composite structure and at least partially forming the housing of the ball joint, and the structural component only extending from the housing in a plane that is perpendicular to the longitudinal axis of the ball joint, and the structural component having a plurality of further holes extending therethrough.

2. The ball joint according to claim 1, wherein the structural component is produced from a preform structure.

3. The ball joint according to claim 1, wherein the further holes being located in a region of the structural component radially spaced from the ball, and the further holes are arranged in a circular arc pattern that is concentric with a center of the ball.

4. The ball joint according to claim 3, wherein the further holes have at least one of a circular shape and an elliptical shape.

5. The ball joint according to claim 1, wherein the housing is designed as at least first and second housing parts, at least the first housing part, being a lower housing part, is formed from the structural component, and at least the second housing part, being an upper housing part, is formed from either a fiber composite material or a light metal.

6. The ball joint according to claim 5, wherein the at least the first and the second housing parts are joined by at least one of gluing, injection, riveting, thermoplastic injection molding and thermosetting injection molding.

7. The ball joint according to claim 5, wherein a bearing shell made of plastic, either mounted to the ball or inserted by injection, is present between the ball and the structural component and at least one of the first and the second housing parts.

8. The ball joint according to claim 7, wherein either a thermoplastic or a thermosetting plastic is injected between at least one of a bearing shell and a bearing cage and either at least one of the first and the second housing parts or the structural part.

9. The ball joint according to claim 5, wherein a bearing cage made of a metal is formed between the ball and the structural component and at least one of the first and the second housing parts.

10. The ball joint according to claim 1, wherein the plurality of further holes being arranged in the planar region of the structural component in a circular arc pattern that is concentric with a center of the ball.

11. A process of manufacturing a ball joint having a ball pin and a housing, the ball pin together with a ball being rotationally and pivotally movably accommodated in the housing, and the ball being at least partially surrounded by a structural component and the structural component is formed primarily from a fiber-plastic composite structure and at least partially forming the housing, the method comprising the steps of: manufacturing and providing the structural component from a preform structure including forming either a hole or a ball-cup type recess for receiving the ball pin; introducing either further holes or interruptions into the structural component that extend therethrough and are arranged in a circular arc pattern that is concentric with a center of the hole or the ball-cup type recess for receiving the ball pin; providing the ball pin; positioning the provided structural components; and joining the provided structural components by at least one of gluing, penetrating injection, riveting, and injection molding by thermoplastic encapsulation or thermosetting encapsulation.

12. The process according to claim 11, further comprising providing at least one further housing part before positioning of the structural components for forming a multipart housing.

13. The process according to claim 11, further comprising either mounting a bearing shell on the ball pin after providing the ball pin or mounting a bearing shell on the ball pin before providing the ball pin.

14. The process according to claim 11, further comprising providing a bearing cage after providing the ball pin.

15. The process according to claim 11, further comprising introducing either the further holes or the interruptions, facing away from a seat of the ball, during the manufacture of the structural component from a preform structure, and the further holes or the interruptions being produced by at least one of drifting, drilling, by designing fiber structures accordingly during manufacture of the preform structure.

16. The process according to claim 11, further comprising integrating the ball joint in a chassis rod made from a fiber-plastic composite preform structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described below on the basis of preferred embodiments with reference to the drawings. In the drawings:

(2) FIG. 1 shows a perspective view of a ball joint installed in a multi-point rod

(3) FIG. 1a shows a partial sectional view of a ball joint in accordance with FIG. 1

(4) FIG. 2 shows a partial sectional view through a ball joint

(5) FIG. 3 a detailed view of the ball joint with a structural component

(6) FIGS. 4a, 4a1 show views of an embodiment of the ball joint

(7) FIGS. 4b, 4b1, 4b2 show views of a further embodiment of the ball joint

(8) FIG. 5 shows a sequence of the process steps according to the invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) FIG. 1 shows a control arm of a motor vehicle in the form of a three-point rod, which is produced from a fiber-plastic composite structure. The control arm 1 is made from a multilayer, flat preform structure, which has been brought into its illustrated form by folding approximately around axis A shown in FIG. 1. A ball joint 1 is introduced at one end of the rod 12. As illustrated in the sectional view in FIG. 1a, the ball joint has a structural part 4, which encompasses the ball pin 3 and the bearing shell 5. The structural part 4 and the bearing shell 5 are encompassed by a housing 2. The ball joint 1 consisting of the above-mentioned components, is introduced here as a pre-assembled ball joint cartridge 1. The housing 2 can be made of plastic or is injection-molded from plastic and accommodates the ball pin 3 with the bearing shell 5 enclosing the ball. The structural part 4 encompasses the cartridge and/or the ball pin and is also held by the plastic of the injection molding. For protection against external influences and corrosion, the ball joint 1 is sealed by a bellows 13 on the side of the pivot, which encompasses the ball pin 3 and the housing 2 in a form-locking manner. The structural part 4, which is completely enclosed by the fiber-plastic composite structure, is provided for establishing the interconnection between the ball joint 1 and the rod 12. As can be seen in FIG. 3, the structural part 4 has an approximately planar form, which flattens towards the side of the end of the structural part (wedge-shaped) facing away from the ball joint 1. The structural part 4 is also penetrated by holes 9, which are arranged approximately concentrically at different radii around the longitudinal axis of the ball joint 1. The structural part 4 itself can be made of a metal material or also of a fiber-plastic composite material. Due to the fact that the structural part 4 is completely enclosed by the fiber-plastic composite structure, a homogeneous bond between the ball joint 1 and the control arm 12 itself results. The holes 9 contribute to a particularly strong bond during the consolidation process because the rod material and/or the matrix material penetrate(s) into the holes 9 during consolidation and the structural part 4 is additionally held in a form-locking manner. During manufacture, a primer or the like may be provided, depending on the material of the structural part or of the housing 2, to provide, depending on the material which is provided for the structural part, in addition to the form fit, a tightly bonded connection between the preform structure and the fiber-plastic composite structure and the structural part.

(10) In the manufacture of a ball joint 1, consisting of at least one ball pin 3 and a housing 2 or a bearing shell 5 enclosing the ball of the ball pin 3, in principle an annealing process during the manufacture of the ball joint or downstream of the manufacture process is necessary. During annealing, the ball joint is heated for a certain period of time to permit the bearing shell material or the structure between the ball pin and the housing to settle. This is required to adjust the breakaway torque of the ball pin inside the housing. This can be dispensed with, as during the manufacture of the rod in the tool temperatures occur, which are sufficient for tempering the ball joint. This results in further possible savings, as during the manufacture of the ball joint or of the cartridge, there is no need for annealing, instead annealing can also be done in the shaping tool during the manufacture of the rod.

(11) FIG. 2 shows the integration of a ball joint 1 into a preformed fiber-plastic composite structure 2b. To do so, a housing made of metal, preferably an upper housing part made of aluminum 2a, has a ball pin 3 having a preassembled bearing shell 5 and the preformed fiber-plastic composite structure 2b (e.g. a preform structure made of TFP) are placed in an injection molding tool, and they are thermoplastically (T-RTM) or duroplastically (HD-RTM) injection-molded. The connection to the housing 2 can be effected both by means of an adhesive bond 11 and tightly bonded connection or form-locking engagement by means of injection molding 8 forming a rivet, or by a combination of the two options. By integrating the aluminum semi-housing into the fiber-plastic composite structure to form a multi-material design, it is ensured that high forces acting on the ball pins, such as the forces shown in FIG. 2 are F.sub.A(extraction) or F.sub.D(compression), can be realized in the case of a control arm made from a fiber-plastic structure, which would alternatively be achievable by possibly complicated, difficult-to-produce fiber orientation.

(12) FIGS. 4a, 4a1 and 4b, 4b1 and 4b2 show further variants of ball joints, which are also suitable for integration in a fiber-plastic composite rod.

(13) FIGS. 4a and 4a1 show a ball joint 1 having a ball pin 3 and a bearing shell 5, the ball pin 3 with enclosing bearing shell 5 being embedded in a metal housing 2 or bearing cage 6. A structural component 4, which encloses the metal housing or the bearing cage 6, is also visible. In other words, the metal housing or the bearing cage is inserted into the structural component 4 in a form-locking manner resulting in the peripheral edge resting against the hole in the structural component 4. The housing 2 encloses the aforementioned components in such a way that the ball pin 3 has the pivoting and rotational mobility typical for ball joints. The housing 2 is inserted by injection molding or encloses the structural component 4 and the bearing cage 6 into a solid composite. The structural part can be made from organic sheets or also using a preform structure produced, for instance, using the TFP method. For an embodiment made of organic sheets, this can be deep-drawn for shaping purposes.

(14) FIGS. 4b and 4b2 show a slightly modified alternative compared to FIGS. 4a and 4a1. In this case, the housing 2 is designed as a second part. The lower part 2b of the housing is designed like the structural part 4 according to FIG. 4a1, no hole being provided, but a spherical indentation or bead 14 being provided, which accommodates the bearing shell 5 or the ball 3a of the ball pin 3 at least in part, preferably half of it. The upper part 2a of the housing 2 or the part 2a of the housing 2 on the side of the pivot 2a is formed by a conical ring 2a, which is connected in a form-locking or tightly bonded manner to the lower part of the housing 2b. As a result, the ball pin 3 with the bearing shell 5 is held in the ball joint 1. As already described with reference to FIG. 2, the connection between the upper housing part 2a and the lower housing part 2b can be provided by adhesive bonding or, as also shown here, by injection molding. The conical ring can be made from deep drawn organic sheets or from a TFP structure. To produce the rod, the component preassembled in this way is inserted into the shaping tool in such a manner that the upper and lower parts of the housing are then enclosed by the fiber composite material or the structure and the injected plastic matrix in the consolidation process. Alternatively, the upper part 2a and the lower part 2b can be joined by injection molding 7 as shown in FIG. 4b.

(15) A sufficient strength of the ball joint with regard to the compressive forces (F.sub.D) or tensile forces (F.sub.A) acting through the ball pin to prevent the ball pin from being extracted by these forces is thus obtained.

(16) FIG. 5 shows a sequence of the process steps according to the invention. In a first step PS, a preform structure is manufactured, e.g. a flat fabric semi-finished product, which is produced by means of the TFP method using hybrid yarns sewn onto the fiat fabric. In a further step PS-<W, the workpiece is introduced into a shaping tool by means of a handling robot. In this step, a ball bearing having a bearing shell mounted thereon is also inserted and positioned into the tool. Then the tool is closed. In a subsequent step, the component is consolidated. A plastic is injected to form the housing. Likewise, a matrix material in the form of a resin is injected into the tool surrounding the knitted fabric. In doing so, a temperature adapted to the materials used and a predetermined pressure are generated in and/or using the tool and maintained for a specific time. The housing and the composite of housing with structural component are produced in this way. Then the ball joint is finished and can be removed from the tool, which again is done by means of a handling robot (step F/W-<K),

(17) It goes without saying that the above-mentioned features of the invention cannot only be used in the respective combination indicated, but also in other combinations or stand-alone, without leaving the scope of the invention. It is likewise within the scope of the invention to effect a mechanical reversal of the functions of the individual mechanical elements of the invention.

REFERENCE NUMERALS

(18) 1 ball joint, cartridge 2 housing 2a upper housing part 2b lower housing part 3 ball pin 3a ball 4 structural component 5 bearing shell 6 bearing cage 7 plastic, injection molding 8 rivet connection, injection molding 9 hole, receptacle, recess 10 hole 11 bond 12 control arm 13 bellows 14 bead F.sub.A extracting force F.sub.D compressive force