Method for producing a riveted connection between a ball joint pin and a component in the form of a metal sheet and associated prefabricated subassembly

Abstract

The invention relates to a method for producing a riveted connection between a ball joint pin, having a pin longitudinal axis (BLA), and a component in the form of a metal sheet with an abutting portion surrounding a preliminary hole, in which the ball joint pin has at least one ball head portion an adjoining shank portion, a planar plate portion, having an upper side and an underside, and a rivet flange portion, in which the ball joint pin is connected to the component by deforming the rivet flange portion. Advantageously, in a first step, the ball joint pin is inserted into the preliminary hole by means of an inserting tool in such a way that the plate portion is supported at least in certain portions by its underside on the abutting portion of the component in the form of a metal sheet, preferably with surface-area contact. In a second step, the rivet flange portion, which at least in certain portions is in the form of a hollow cylinder, is subsequently deformed in a controlled manner in the direction of the component in the form of a metal sheet by of a forming tool in the form of a die, in particular a riveting punch, to produce the riveted connection.

Claims

1. A method for producing a riveted connection between a ball joint pin having a longitudinal pin axis (BLA) and a sheet metal component having a contact section that surrounds a preliminary hole, wherein the ball joint pin comprises at least a ball end section, an adjoining shaft section, a planar plate section comprising an upper side of the planar plate section and an underside of the planar plate section, and a sectionally hollow-cylindrical rivet collar section, and wherein the ball joint pin is connected to the sheet metal component by deforming the sectionally hollow-cylindrical rivet collar section, comprising the following steps in order of: (a) joining the ball joint pin into the preliminary hole using a sleeve shaped joining tool such that there is applied a controlled application of contact force and reaction force directly to the ball joint pin by the sleeve shaped joining tool for joining the ball joint pin into the preliminary hole of the sheet metal component such that the planar plate section has the underside of the planar plate section at least sectionally supported flatly on the contact section of the sheet metal component; (b) deforming the sectionally hollow-cylindrical rivet collar section in a direction of the sheet metal component in a controlled fashion by a beaded forming die or a riveting punch, while the ball joint pin is being held in place by the sleeve shaped joining tool, in order to produce the riveted connection, wherein an applied deformation force is applied to the sectionally hollow-cylindrical rivet collar section in a controlled fashion by the beaded forming die or riveting punch, and wherein a hollow portion of the sectionally hollow-cylindrical rivet collar section is pre-beaded by the beaded riveting punch forming a pre-beaded rivet collar section; (c) removing the sleeve shaped joining tool; and (d) then striking the pre-beaded rivet collar section with a processing tool to ensure that the pre-beaded rivet collar section flatly contacts an underside of the sheet metal component, wherein the sectionally hollow-cylindrical rivet collar section comprises a hollow portion and a solid portion, and the sectionally hollow-cylindrical rivet collar section is deformed without rollers in a region of the hollow portion such that an air gap remains between the sheet metal component and deformed sections of the hollow portion of the sectionally hollow-cylindrical rivet collar section and/or free ends of the sectionally hollow-cylindrical rivet collar section, and wherein the hollow portion of the sectionally hollow-cylindrical rivet collar section is outwardly deformed between 80 and 90 from the longitudinal pin axis (BLA).

2. The method according to claim 1, wherein an applied contact force (AF) is applied to the ball joint pin in a controlled fashion at least in a region of the upper side of the plate section and/or in a region of the ball end section by the joining tool.

3. The method according to claim 2, wherein an absolute value of the applied contact force (AF) is controlled by a spring unit or pneumatic spring unit that is functionally connected to the joining tool.

4. The method according to claim 1, wherein an absolute value of the applied deformation force (FF) is controlled by a spring unit or pneumatic spring unit that is functionally connected to the riveting punch.

5. The method according to claim 1, wherein the method produces a prefabricated assembly comprising a ball joint pin and a sheet metal component having a contact section surrounding a preliminary hole, wherein the ball joint pin comprises a ball end section, an adjoining shaft section, a planar plate section with an upper side and an underside and a rivet collar section, and wherein the ball joint pin is connected to the sheet metal component by deforming the rivet collar section, and wherein the rivet collar section is sectionally designed as a sectionally hollow-cylinder rivet collar section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in greater detail below with reference to exemplary embodiments illustrated in the figures. In these figures:

(2) FIG. 1 shows a schematic side view of a ball joint pin according to the invention,

(3) FIG. 2 shows a longitudinal section through a ball joint pin according to the invention,

(4) FIG. 3 shows a schematic section through a ball joint pin that is accommodated in a joining tool and connected to the sheet metal component by joining,

(5) FIG. 4 shows a schematic section through the arrangement of the ball joint pin and the sheet metal component according to FIG. 3 after the riveting process,

(6) FIG. 5 shows a schematic section through a ball joint pin that is accommodated in an alternative joining tool and connected to the sheet metal component by joining,

(7) FIG. 6 shows a schematic section through the arrangement of the ball joint pin and the sheet metal component according to FIG. 5 after the riveting process,

(8) FIG. 7 shows a schematic section through an alternative arrangement of the ball joint pin and the sheet metal component after the riveting process,

(9) FIG. 8 shows a schematic section through a riveted connection between a ball joint pin and a sheet metal component produced in accordance with the invention after a subsequent processing of a pre-beaded rivet section by means of restriking,

(10) FIG. 9 shows a schematic section through a riveted connection between a ball joint pin and a sheet metal component produced in accordance with the invention with reinforced contact sections, and

(11) FIG. 10 shows a schematic section through a riveted connection between a ball joint pin and a sheet metal component produced in accordance with the invention with a reinforcing element.

DETAILED DESCRIPTION OF THE INVENTION

(12) FIG. 1 shows an example of a ball joint pin 1 according to the invention that is preferably realized in one piece. For example, the ball joint pin 1 is made of metal or a metal alloy.

(13) The ball joint pin 1 according to the invention extends along a longitudinal pin axis BLA and comprises at least one ball end section 1.1, an adjoining shaft section 1.2, which is followed by a planar plate section 1.3 with an upper side and an underside 1.31, 1.32 and an at least sectionally hollow-cylindrical rivet collar section 1.4 adjoining the plate section along the longitudinal pin axis BLA. In a preferred embodiment, the rivet collar section 1.4 comprises a hollow portion 1.41 and a solid portion 1.42. FIG. 2 shows a schematic longitudinal section through the ball joint pin 1.

(14) The shaft section 1.2 is preferably configured to be conical, i.e. the shaft section 1.2 has a circular cross section and a diameter D that increases along the longitudinal pin axis BLA, wherein the diameter D particularly increases along the longitudinal pin axis BLA from a first diameter D1 at the ball end section 1.1 to a second diameter D2 at the plate section 1.3. In one embodiment, the second diameter D2 in the region of the plate section 1.3 approximately corresponds to or is designed to be larger than the ball diameter KD of the ball end section 1.1. The second diameter D2 of the shaft section 1.2 in the region of the plate section 1.3 may lie, for example, between the ball diameter KD of the ball end section 1.1 and 1.2-times this ball diameter. For example, the first diameter D1 lies between 0.5 mm and 1.4 mm and the second diameter D2 lies between 0.8 and 1.4 mm. A ball diameter KD between 0.8 mm and 1.2 mm is preferably provided. The dimensions of the ball end section 1.1, particularly its ball diameter KD, are largely standardized and therefore defined.

(15) The plate section 1.3 is configured to be discoidal such that the upper side and the underside 1.31, 1.32 of the plate section 1.3 extend parallel to one another and respectively form surfaces or contact surfaces that annularly surround the shaft section 1.2 and the rivet section 1.4. The upper side and the underside 1.31, 1.32 respectively extend in a plane that lies perpendicular to the longitudinal pin axis BLA. For example, the plate diameter TD of the plate section 1.3 lies between 1.5-times and 2-times the ball diameter KD, preferably between 1.2 mm and 2.5 mm. The plate thickness TS of the plate section 1.3 along the longitudinal pin axis BLA lies, for example, between 1.5 mm and 5.0 mm.

(16) The at least sectionally hollow-cylindrical rivet collar section 1.4 preferably has an outside diameter ND that is smaller than the second diameter D2 of the shaft section 1.2. For example, the hollow portion 1.41 of the rivet collar section 1.4 extends at least over half the length L of the rivet collar section 1.4 facing away from the plate section 1.3, i.e. the hollow portion extends over at least half of the rivet collar section 1.4. In this context, the length L is dependent on the sheet thickness BS of the sheet metal component 2. For example, the sheet thickness BS lies between 0.7 mm and 5.0 mm.

(17) The wall thickness S of the rivet collar section 1.4 in the region of the hollow portion 1.41 lies between 0.5 mm and 2.5 mm. In this case, the hollow-cylindrical rivet collar section 1.4 extends concentrically to the longitudinal pin axis BLA. For example, the hollow portion 1.41 extends over of the length L and the remaining solid portion 1.42 of the rivet collar section 1.4 extends over at least of the length L. In an advantageous embodiment, the longitudinal dimension of the solid portion 1.42 of the rivet collar section 1.4 approximately corresponds to the sheet thickness BS of the sheet metal component 2, with which the riveted connection should be produced. It is particularly preferred that the longitudinal dimension of the solid portion 1.42 is smaller than or equal to the sum of the wall thickness S of the rivet collar section 1.4 in the region of the hollow portion 1.41 and the sheet thickness BS minus the height of a forming die, particularly a riveting punch 4.

(18) The method according to the invention relates to the production of riveted connections between such a ball joint pin 1 and a sheet metal component 2, preferably a metal sheet or formed metal sheet that is preferably part of a prefabricated subassembly. Such a prefabricated subassembly is used, for example, in the series production of products, for example automobiles in order to reduce the depth of production, to shorten the production time and to thereby achieve cost savings. The method according to the invention makes it possible to already incorporate the ball joint pin 1 into the sheet metal component 2 during its manufacturing process, particularly during the forming process of the sheet metal component 2, i.e. the method for producing the riveted connection is integrated into the manufacturing or forming process of the sheet metal component into a prefabricated subassembly such that enormous cost savings can be achieved.

(19) A preliminary hole 2.1, which is surrounded by a contact section 2.2, is produced in the sheet metal component 2 having an upper side and an underside 2, 2 in order to install the ball joint pin 1. The contact section 2.2 is preferably designed planar and/or for flatly contacting the underside 1.32 of the plate section 1.3. The diameter of the preliminary hole 2.1 is preferably smaller than the outside diameter ND of the rivet collar section 1.4.

(20) According to the invention, the ball joint pin 1 is in a first step joined into the at least one preliminary hole 2.1 in the sheet metal component 2 by means of a joining tool 3 such that the planar plate section 1.3 provided between the shaft section 1.2 and the rivet collar section 1.4 is preferably supported flatly on the contact section 2.2 of the sheet metal component 2 with its underside 1.32 and thereby presses the pin against the upper side 2 of the sheet metal component with a contact force AF. In a second step, the at least sectionally hollow-cylindrical rivet collar section 1.4 is deformed in a controlled fashion in the direction of the sheet metal component 2 by means of a forming die, particularly a riveting punch 4, in order to produce the riveted connection, wherein the riveting punch 4 is for this purpose particularly moved in the direction of the rivet collar section 1.4 in a controlled fashion along the longitudinal pin axis BLA. A controlled displacement of the sheet metal component 2 with the ball joint pin 1 joined therein would alternatively also be conceivable. As a result, the rivet collar section 1.4 is acted upon with a deformation force FF that can be adjusted, for example, by means of a spring unit 5, 6, particularly a pneumatic spring unit. The spring unit 5, 6 may be functionally connected to the riveting punch 4 and/or the joining tool 3.

(21) FIGS. 3 and 4 show examples of the first and the second step of the method according to the invention, namely the joining of the ball joint pin 1 into the preliminary hole 2.1 in the sheet metal component 2 along the longitudinal pin axis BLA extending perpendicular to the upper side 2 of the sheet metal component 2. The deformation of the rivet collar section 1.4 then takes place in the second step due to a controlled application of the deformation force FF by means of the spring unit 5 in such a metered fashion that the formation of microcracks R can be effectively prevented in the region of the shaft section 1.2 of the ball joint pin 1, namely while the contact force AF is maintained by supporting the ball joint pin 1 at least in the region of the upper side 1.31 of the plate section 1.3, the underside 1.32 of which contacts the upper side 2 of the sheet metal component 2 in the contact section 2.2. Particularly the tensions in the shaft section 1.2 of the ball joint pin 1 resulting from the deviating lines of force of the contact force AF and the deformation force FF are effectively reduced due to the controlled application of the deformation and/or contact forces AF, FF in accordance with the invention.

(22) The ball joint pin 1 is joined into the preliminary hole 2.1 of the sheet metal component 2 without noteworthy deformation of the contact section 2.2 of the component 2, i.e. without sinking the plate section 1.3 of the ball joint pin 1 into the planar contact section 2.2 of the sheet metal component 2.

(23) The application of the contact force AF by means of the joining tool 3 may alternatively or additionally take place in a controlled fashion, for example, by means of a spring unit 6 that is functionally connected to the joining tool 3.

(24) FIGS. 5 and 6 show an alternative embodiment of the joining tool 3, in which the contact force AF is not only applied to the ball joint pin 1 in a controlled fashion in the region of the upper side 1.31 of the plate section 1.3, but also in the region of the ball end section 1.1. For this purpose, the joining tool 3 is designed in a sleeve-like fashion at least in the region functionally connected to the ball joint pin 1 and is supported on the upper side 1.31 of the plate section 1.3 with the free end regions, as well as on the ball end section 1.1 with the inner sleeve surface. The controlled application of the contact force AF to the ball joint pin 1 by means of the joining tool 3 for joining the ball joint pin into the preliminary hole 2.1 of the sheet metal component 2 is realized with the aid of a spring unit 6. In the present exemplary embodiment according to FIGS. 5 and 6, two spring units 5, 6 are respectively provided. However, it goes without saying that only one of the spring units 5 or 6 may alternatively be used for realizing the controlled application of the contact force AF and/or the deformation force FF in accordance with the invention.

(25) In the alternative embodiment according to FIG. 7, the joining tool 3 is in fact also realized in a sleeve-like fashion, but the inner sleeve surface is not supported on the ball end section 1.1. In addition, the contact force AF is also applied without a spring unit 6. Consequently, the applied forces AF, FF are exclusively controlled by means of the spring unit 5 that is functionally connected to the riveting punch 4.

(26) In another embodiment that is not illustrated in the figures, a spring-loaded support of the ball joint pin 1 by means of a correspondingly designed two-part joining tool 3 may also be realized in the region of the ball end section 1.1 only, i.e., the support in the region of the upper side 1.32 of the plate section 1.3 is not realized in a spring-loaded fashion.

(27) According to the invention, the rivet collar section 1.4 is deformed without rollers in such a way that an air gap remains between the underside 2 of the sheet metal component 2 and the deformed sections of the rivet collar section 1.4, namely at least between the free end regions 1.4, 1.4 of the rivet collar section 1.4 and the underside 2 of the sheet metal component 2. In this case, the free end regions 1.4, 1.4 of the rivet collar section 1.4 are oriented outward and point away from the underside 2 of the sheet metal component 2. In the method according to the invention, the rivet collar section 1.4 is outwardly deformed by up to 90, preferably between 80 and 90, referred to the longitudinal pin axis BLA and the hollow portion 1.41 of the rivet collar section 1.4 is thereby expanded.

(28) In a preferred embodiment, the rivet collar section 1.4 is in the second step of the inventive method initially pre-beaded and the pre-beaded rivet collar section 1.4 is subsequently restruck by means of a suitable processing tool 7 in order to ensure that the pre-beaded section of the rivet collar section 1.4 flatly contacts the underside 2 of the sheet metal component 2.

(29) FIG. 8 shows a section through a prefabricated subassembly comprising a sheet metal component 2 that is riveted to a ball joint pin 1 in accordance with the invention, wherein the pre-beaded sections of the rivet collar section 1.4 of said ball joint pin are restruck by means of the processing tool 7. The aforementioned deformation steps may be realized by means of one or more forming stations.

(30) In an embodiment that is not illustrated in the figures, the contact section 2.2 around the preliminary hole 2.1 may be at least slightly curved upward or downward referred to the upper side or underside 2, 2 of the sheet metal component 2 before the inventive method is carried out. The grommet of the contact section 2.2 surrounding the preliminary hole 2.1 is transferred into the planar state again after the joining and riveting processes have been carried out such that the underside 1.32 of the plate section 1.3 once again flatly contacts the upper side 2 of the sheet metal component 2.

(31) When using particularly thin sheet metal components 2, for example, with a sheet thickness BS between 0.7 mm and 1.5 mm, the contact section 2.2 is reinforced by doubling the sheet metal thickness BS, namely by correspondingly beading or folding over the sheet metal component in the contact section 2.2 in accordance with FIG. 9 such that a reinforced contact section 2.2 is formed. Beading of the contact section 2.2 is carried out, for example, if the sheet thickness BS is smaller than 1.5 mm, namely in dependence on the forces to be transmitted.

(32) It would alternatively be possible to use an additional discoidal reinforcing element 8 such as, for example, a reinforcing metal sheet that is inserted between the deformed sections of the rivet collar section 1.4 and the underside 2 of the sheet metal component 2. The discoidal reinforcing element 8 preferably has a thickness of at least 1 mm.

(33) The invention was described above with reference to exemplary embodiments. It goes without saying that numerous variations and modifications are possible without thereby deviating from the scope of the invention.

REFERENCE LIST

(34) 1 Ball joint pin

(35) 1.1 Ball end section

(36) 1.2 Shaft section

(37) 1.3 Plate section

(38) 1.31 Upper side

(39) 1.32 Underside

(40) 1.4 Rivet collar section

(41) 1.41 Hollow portion

(42) 1.42 Solid portion

(43) 1.4, 1.4 Free end regions

(44) 2 Sheet metal component

(45) 2 Upper side

(46) 2 Underside

(47) 2.1 Preliminary hole

(48) 2.2 Contact section

(49) 2.2 Reinforced contact section

(50) 3 Joining tool

(51) 4 Riveting punch

(52) 5 Spring unit

(53) 6 Spring unit

(54) 7 Processing tool

(55) 8 Reinforcing element

(56) AF Contact force

(57) BLA Longitudinal pin axis

(58) BS Sheet thickness

(59) D Diameter

(60) D1 First diameter

(61) D2 Second diameter

(62) FF Deformation force

(63) L Length

(64) ND Outside diameter

(65) S Wall thickness

(66) TS Plate thickness

(67) TD Plate diameter

(68) R Microcracks