DE102005036249B4 - Assembly comprising a plastic part and a sheet metal part connected thereto - Google Patents

Abstract

Assembly comprising
a plastic part (10) and a sheet metal part (22) connected thereto, wherein the sheet metal part (22) and the plastic part (10) are joined by plastically deforming a rivet dome (12) formed integrally with the plastic part (10) Plastic part (10) passes through an opening (24) of the sheet metal part (22) along an enforcement direction (F) and engages behind with a rivet head (26) resulting from the plastic deformation, wherein an inner edge (30) of the opening (24) is defined as the closed curve with the smallest surface area circumscribing the opening (24) and lying in a plane orthogonal to the direction of enforcement (F) on a sheet metal part outer surface (22b),
characterized in that the rivet head (26) has the following characteristic surfaces:
a virtual closed inner loading surface (38) which extends from the inner edge (30) of the opening (24) in the radial direction to an opening axis (O) which contains the centroid of the opening (24) and extends in the direction of enforcement (F), and a virtual closed ...

Description

The The present invention relates generally to an assembly comprising a plastic part and a sheet metal part connected thereto, wherein the sheet metal part and the plastic part in such a way by plastic deformation one piece assembled with the plastic part formed rivet dome, that plastic material of the plastic part has an opening of the Sheet metal part along penetrated by a direction of enforcement and with one of the plastic Deformation resulting rivet head engages behind.

In industry, especially in the automotive industry such assemblies frequently encountered, in which plastic and sheet metal parts are connected together. In these assemblies can the advantageous properties of the different ones used Materials are well exploited, for example, by comparison to the plastic part higher Basic strength of a sheet metal part to provide a desired stability is used and at the same time the diverse design options of plastic parts to provide a desired complex geometry are used, of course, always be more functional requirements to be met by the individual parts can.

An assembly in which a plastic part and another component, which is not disclosed as a sheet metal part, however, are assembled by plastically deforming a rivet dome integrally formed with the plastic part is known from DE 100 38 158 A1 known. In this case, the plastic material passes through an opening of the further component and engages behind it with a resulting from the plastic deformation rivet head.

Often, in the prior art, as described above, the plastic part is formed from a thermoplastic material, in other embodiments a tubular rivet dome may protrude from the plastic part and be configured to pass through an opening in the sheet metal part, the rivet dome being plastic in the enforced state is deformed so that a rivet head resulting from the rivet dome by its deformation materially engages behind the sheet metal part with the plastic part in a form-fitting manner. The plasticizing of the plastic material required for the forming of the rivet mandrel can be carried out by heating by means of hot air, by ultrasound treatment or the like. In the DE 100 38 158 A1 the deformation of the rivet dome to a rivet head is effected, for example, by a heatable forming punch, which is lowered along the direction of penetration onto the rivet dome.

According to the procedure The prior art was that of plastic deformation itself resulting rivet head not previously the subject of detailed design investigations. Sufficient connection security was essentially provided by provision a sufficient number of joints with appropriate rivet heads generated.

It is therefore an object of the present invention, the connection between a sheet metal part and a plastic part to form an assembly of the type mentioned above to improve in order to Achieving the greatest possible Bonding strength of a single compound both the number of a total needed Connecting points for larger components as well as the material and conversion work effort to optimize at a single connection point.

These Task is done according to a First aspect of the present invention solved by a Assembly with all features of claim 1.

at the strength-oriented design of the riveted joint has it it has been shown that there are enough characteristic places to determine the rivet head and the sheet metal part and the Nietkopfgeometrie as well as the geometry of the sheet metal part opening with respect to this characteristic places to make a riveted connection with to achieve significantly better strength properties than they used to are known in the art.

to easier description of the connection of plastic part and sheet metal part be first the inner edge of the sheet metal part opening Are defined. The inner edge of the sheet metal part opening is a lying on the sheet metal part outer surface closed curve. The closed edge forming the inner edge of the opening Curve lies in a plane orthogonal to the direction of enforcement, in which plastic material passes through the opening in the sheet metal part. Here is the inner edge of the opening the one of all possible curves, which the smallest surface area having. If, for example, in a cylindrical opening of the sheet metal part, several Curves the same area should have, for the purposes of the present application, the one these curves, which are the closest is located towards the rivet head, the rivet-side inner edge of the opening and that of the curves closest to the plastic part, the plastic part side inner edge of the opening.

A first of the aforesaid characteristic surfaces used to describe the rivet head and its geometry is a virtual closed inner loading surface extending from the inner edge of the opening into a radial one Direction extends to an opening axis of the sheet metal part opening. The opening axis contains the area centroid of the opening area and extends in the direction of enforcement. Another characteristic surface is a virtual closed rivet head shear surface, which extends counter to the direction of enforcement of an outer surface of the rivet head to the, possibly rivet head side, inner edge of the opening. Orthogonal to the direction of penetration, the virtual rivet shearing surface extends along the inner edge of the opening. This virtual rivet shear surface is thus located completely inside the rivet head. Since the inner edge of the opening is a closed curve, thus also the virtual inner load surface and the virtual Nietkopf shear surface are closed.

A another surface which characterizes the rivet connection is a virtual closed sheet-metal part shear surface which along the radially outer edge the contact surface of the rivet head on an outer surface of the rivet head facing the rivet head Sheet metal part and in the direction of enforcement over the entire sheet metal thickness extends.

According to the present Invention, the rivet head is no longer as in the prior art is formed with a unitary tool but is used during forming designed such that the surface contents each of the inner load surface, the virtual rivet head shear surface and the virtual sheet metal shearing surface depending on one of the Connection of plastic part and sheet metal part exerted predetermined Burden and depending of predetermined material properties of the plastic part and of the sheet metal part are dimensioned.

This means that a plurality of different forming dies need to be present for forming the rivet dome in a rivet head, which differ in their shape geometry at least such that the rivet heads that emerge from each of them have virtual rivet head shear planes, respectively different surface contents and on the sheet metal part adjacent outer edges with have different radii. From the majority of forming dies is based on a predetermined load case as well as on based on predetermined material properties of plastic material and sheet such as tensile strength, surface pressure and shear strength etc., the most appropriate forming die selected and generated with this the rivet head.

This Although the procedure is opposite the previously used method with a unit forming stamp more expensive, but is produced by the significantly higher strength of the Rivet connection more than justified.

going assume that the geometry of the opening of the sheet metal part as the first is fixed, then the area becomes the virtual rivet shear surface only still determined by the height of the Nietkopfes in the direction of enforcement above the (nietkopfnahen) inner edge the sheet metal part opening.

As well is the outer edge the contact surface of the Nietkopfes on the outer surface facing the sheet metal part clearly defined by its radius. Through this simplification, the Classification and selection of forming dies greatly facilitated become.

The internal load area is unlike the other two mentioned characteristic surfaces not only by reshaping the rivet dome to a rivet head, but already created by inserting the rivet dome through the sheet metal part opening.

For the riveted joint are essentially two load cases of great Meaning, these are on the one hand a tensile load in the direction of enforcement and on the other hand, a thrust load orthogonal to the direction of enforcement, the latter also known as shear stress.

in the If a tensile load in the direction of enforcement, it has to be extremely beneficial proven, if the rivet head is designed such that the percentage Utilization of the tensile strength of the plastic part in the inner Loading area the percentage utilization of the shear load capacity of the plastic part in the virtual rivet shear surface and the percentage utilization the shear load capacity of the sheet metal part in the sheet metal part-shear surface substantially are the same size.

With Utilization of a specific load capacity, such as shear load capacity, is the ratio from actually occurring load of the respective type, such as shear stresses, due to material strength maximum possible load of the respective Type, about shear stress strength, in percent called.

The Utilization is intended in the sense of the present application as "essentially same size "apply when the percentage utilization of shear load in the virtual Rivet head-shaving surface and compressibility in the outer pressure surface is not more than 20%, preferably not more than 10%, more preferably do not differ more than 5%.

In most cases, the opening in the sheet metal part will have a circular cross section, so that the axis of the opening passes through the center of the curve. However, from the present application tion openings with any cross-sectional shapes can be detected. In this case, the axis which contains the area center of gravity of the surface circumscribed by the inner edge of the opening generally applies as the opening axis.

There for safety reasons It should not be assumed that a central section of the the opening closing in the sheet metal part Plastic material in a significant way for receiving on the rivet connection acting loads is preferably only one longitudinal the opening edge running surface with radial extent to the opening axis considered, which radially but not to the opening axis extends. It has proved to be extremely advantageous here if one chooses the virtual inner load surface such that They are essentially about the half radial distance of the opening edge of the opening axis extends.

The The above object is according to a further aspect of the present invention also solved by an assembly with all features of claim 4. It has shown that a significantly increased Joining strength can be obtained when a section surrounding the opening of the sheet metal part with respect to of the surrounding sheet is angled in the direction of enforcement. This bend is hereafter referred to as "edge stop" such a bend is achieved that the opening in Sheet metal part arbitrarily selectable by an edge projecting from the sheet metal part Height edged is. This edge is advantageously encompassed by the rivet head, which significantly increases the positive locking properties of the riveted joint, especially with regard to stresses due to vibration.

For the rest above-mentioned Load case by shear load, it is advantageous to a inner pressure surface the rivet connection of the assembly as a further characteristic surface of the To use riveting, which is defined as the projection the contact surface the rivet head on the sheet metal part in a direction of enforcement orthogonal thrust load direction orthogonal to the thrust loading direction Projection plane. In the simplest case one of a sheet metal part punched opening is the inner pressure surface at a lying in a sheet metal plane Schubbelastungsrichtung then defined by the projection of half described above Circumference of the opening multiplied by the sheet metal thickness in the area of the opening.

Additionally or as an alternative to the aforementioned design of the riveted joint, it has especially in view of the load capacity of the riveted joint a thrust load proved to be advantageous when the area each of the inner pressure surface and the inner load surface dependent on from a predetermined one exerted on the connection of plastic part and sheet metal part Burden and depending of predetermined material properties of the plastic part and of the sheet metal part are dimensioned.

at a thrust load applied orthogonal to the direction of enforcement becomes this inner pressure surface strained on pressure while the aforementioned virtual load area experiences a shearing load. It It has been found that an advantageous, long-lasting, riveted joint is present when the rivet head and sheet metal part are designed in such a way that at the designated shear load the percentage utilization the permissible surface pressure of the sheet metal part in the inner pressure surface and the percentage utilization the shear load capacity of the plastic part in the virtual load area substantially are the same size. With regard to the property "im Essentially the same size "will be on top Said directed.

in this connection is to be noted that when providing a Kantenabstellung the contact surface, on which the inner pressure surface based, consists of two faces, namely a first partial area, which is formed on a surface portion facing the opening axis of the opening delimiting sheet metal section and a second partial surface, which is the first subarea in terms of opposite the opening axis on a surface portion pointing away from the opening axis on the edge stop is trained.

The inner pressure surface in the sense of the present application, in the case of a trained at the opening Edges off the sum of the designated projection of these formed two partial surfaces be.

It is in connection with the design of the rivet head given above in terms of the percentage utilization of the permissible surface pressure of the sheet metal part easy to see in the inner printing area, that by edge cutting at the same material strengths of Plastic part and sheet metal part and the same thrust load in the inner pressure surface occurring compressive stress due to the now larger area decreases, so that the percentage utilization of the permissible surface pressure decreases with increasing edge trim. Therefore, the provision of the Edge cut off as well as the choice of the height of the parked and the opening enclosing Sheet metal edge another strength of the riveted joint the assembly defining design parameters.

Finally, the above object is also achieved by a further aspect an assembly with all features of claim 8. It is advantageous if the rivet head is designed such that it has its maximum extent in the direction of enforcement with respect to an orthogonal to the enforcement direction reference plane, such as the plane of the opening of the inner edge, above the inner edge of the opening and in that it furthermore has its maximum extent orthogonal to the direction of penetration in the contact surface on the side of the sheet-metal part facing the rivet head. Under these conditions, the rivet head is obtained with the least cost of materials either for a given strength, or it is obtained at a given for the formation of the rivet head available material of the rivet head with the greatest strength.

Preferably are to avoid preferential directions of the rivet head and thus also the sheet metal part opening formed rotationally symmetrical. In this case, the above specified design of the riveted joint can be further simplified by instead of the characteristic areas only their characteristic dimensions in a rotational symmetry axis of the rivet head containing Longitudinal section plane be used. In rotationally symmetrical rivet heads falls the Enforcement direction with the direction of the rotational symmetry axis together. In this case, it is easy to see that all the characteristic surfaces the longitudinal plane of symmetry containing the rotational symmetry axis orthogonal along a cut each cutting line. The cut lines obtained in this way represent the above characteristic dimensions and can then for determining the design of the rivet head the aforementioned surfaces replace.

to further material savings, the plastic part on his vom Nietkopf side facing away in the region of the opening have a recess.

As already mentioned above, the undeformed rivet dome is in the Connection preparation often as a tubular component trained, such as by injection molding or pressing. It is in the prior art, the opening inside the tubular rivet dome Occasionally continuous in the extension direction of the rivet dome. hereby can leak and strength problems on the assembly result in interconnected plastic part and sheet metal part. For example Moisture can pass through the channel formed by the rivet dome one side of the module to the other. This can be done prevents the plastic part from being formed in such a way that that the opening of the Sheet metal part of plastic material of the connected to the sheet metal part Plastic part is closed. Apart from the thus achieved Tightness becomes such in the connection area of plastic part and Sheet metal part obtained by continuous plastic surface, giving the strength the plastic part as a whole, but especially in the field of Connection, increased.

The The present invention will be described below with reference to the attached Drawings closer explained become. It shows:

1 a plastic part with undeformed rivet dome molded onto it,

2 an embodiment of a riveted connection between the plastic part of 1 and a sheet metal part by plastic deformation of the rivet dome of 1 , and

3 a plan view of a section of the rivet connection along one on the sheet metal part surface 22a lying sectional plane III-III.

In 1 is a plastic part made of thermoplastic generally with 10 designated. The plastic part 10 has an integrally formed on him undeformed rivet dome 12 on. The rivet dome is rotationally symmetric around the plane of the drawing 1 lying rotational symmetry axis R formed. The floor 14 of the rivet dome 12 is closed, leaving the plastic part 10 a continuous plastic surface 10a forms. In the area of the rotational symmetry axis R, the plastic part has 10 a depression 16 which is also rotationally symmetrical with respect to the axis R is formed.

The thickness d of the rivet dome at its front end is about 90% of the thickness D of the substantially flat plastic part 10 , Due to draft, the thickness d of the rivet dome increases 12 along the axis R to the plastic part 10 slightly too.

In 2 is finally an assembly 20 from the plastic part of 1 and a sheet metal part connected thereto 22 to see.

The plastic material of the plastic part 10 passes through an opening 24 of the sheet metal part 22 in the direction of enforcement F, which is equal to the direction of the rotational symmetry axis R.

By plastic deformation of the rivet dome 12 from 1 is the in 2 in longitudinal section shown rivet head 26 emerged.

This rivet head 26 lies on a rivet head 26 facing outer surface 22a of the sheet metal part 22 at. Furthermore, there is the plastic part 10 on an opposite outer surface facing the plastic part 22b of the sheet metal part 22 at. Of the rivet head 26 thus provides a positive connection of the plastic part 10 with the sheet metal part 22 ago.

The sheet metal part 22 is in its near-mouth area to form a border of the opening 24 angled in the direction of enforcement F and thus forms by edging an enclosure 28 the opening 24 , This surround 28 forms a cylindrical edge portion of the opening 24 , The in the drawing plane of 2 rotational symmetry axis R nearest edge of the enclosure 28 forms the inner opening edge 30 the opening 24 ,

From the outside surface 26a of the rivet head 26 from runs opposite to the enforcement direction F about the rotational symmetry axis R circumferential virtual closed Nietkopf shear surface 32 to the inner edge 30 the opening 24 , This virtual rivet head shear surface 32 is subjected to shear or thrust at a tensile load along the rotational symmetry axis R.

The attachment of the rivet head 26 on the outside surface 22a the sheet metal part takes place more precisely in a contact surface surrounding the rotational symmetry axis R. 34 of the rivet head 26 in the form of a circumferential annular surface. Due to the Kantenabstellung this outer contact surface 34 graduated.

Another characteristic surface of the riveted joint is a virtual sheet metal shear surface 35 , which are along an outer edge 27 of the rivet head 26 in the contact area 34 and parallel to the direction of enforcement F over the height of the sheet metal part 22 extends.

Another characteristic surface is an inner pressure surface 37 , The inner pressure surface 37 consists of two partial surfaces 37a and 37b , This inner pressure surface 37 plays a role in the load of the shown rivet joint by thrust in a shear loading direction S in the drawing plane of 2 orthogonal to the rotational symmetry axis R. In this case, the inner pressure surface is based 37 on those surface sections 36a and 36b of the sheet metal part 22 , with which plastic material of the plastic part 10 is in plant whose normal vector continues to have a parallel to the direction S of the thrust component and in which the thrust force to a pressure load of the sheet metal part 22 in the contact area leads. This is in the in 2 and 3 shown example in the assumed load by the thrust S, the substantially semi-cylindrical part surface 36a on the inner circumference of the opening boundary as well as the likewise substantially semi-cylindrical partial surface 36b on the outer circumference of the edge stop. As it is not necessary to calculate the pressure load on the curvature of the respective partial surfaces 36a and 36b arrives, these are considered partial surfaces 37a and 37b the inner pressure surface 37 in the projection in the direction of the thrust force direction S on a projection plane orthogonal to this considered. The projection plane of the inner printing surface 37 is in 2 dashed line with PE1 indicated.

Finally, in the design and description of the rivet head 26 considered another characteristic area, namely the virtual load area 38 , This is orthogonal to the direction of enforcement F and extends from the inner edge 30 the opening 24 radially inward to the axis of rotation R identical opening axis O out. The ring-shaped virtual load surface has 38 a radial extent which is approximately half the radial extent of the opening 24 equivalent. For safety reasons, it is assumed that the rotationally symmetric region of the opening 24 occlusive plastic material does not significantly contribute to the absorption and transmission of loading forces.

For reasons of clarity, the surfaces 32 . 34 . 35 . 36 and 38 only in each case with a section line with the plane of the 2 shown. However, it should be emphasized once again that it is the surfaces 32 . 34 . 35 and 38 around closed, about the rotational axis of symmetry R circumferential surfaces. The surfaces 34 and 38 are essentially annular, the surfaces 32 and 35 are cylindrical. The area 36 is approximately composed of two cylindrical half shells.

The rivet head 26 is designed such that at a predetermined tensile load of the module 20 , or the rivet connection, in the direction of the opening axis O, the percentage utilization of the maximum tensile strength of the plastic material in the virtual load surface 38 , the percentage utilization of the maximum shear resistance of the plastic material in the virtual rivet shear surface 32 and the percentage utilization of the shear strength of the sheet metal part 22 in the virtual sheet metal shear area 35 not more than 20%, preferably not more than 10%, more preferably not more than 5%, differ. The limits for the differences in the percentage utilization of the maximum material loadings of 20%, preferably 10%, particularly preferably 5%, apply in pairs for all surfaces of the virtual rivet head shear surface 32 , the virtual sheet metal shear plane 35 and the virtual load area 38 ,

When percentage utilization of maximum material strength is thereby The relationship from actually occurring load to material-specific maximum possible Load of the same kind in percent.

Alternatively or additionally, the rivet head 26 and the sheet metal part 22 be formed by Kantenabstellung such that at pure shear load orthogonal to the opening axis O, the percentage utilization of the permissible surface pressure of the sheet metal part 22 in the inner pressure surface 37 and the percentage utilization of shear strength of the plastic material in the virtual load area 38 not more than 20%, preferably not more than 10%, more preferably not more than 5%, differ.

The rivet head 26 indicates its on the surface 22a of the sheet metal part 22 adjoining outer edge 27 its largest radial extent starting from the opening axis O on. Furthermore, the rivet head 26 in the direction of enforcement F over the inner edge 30 its greatest extent in the direction of enforcement with respect to an orthogonal to the opening axis O reference plane. The reference plane used in the example shown is the plane of the surface 22a of the sheet metal part 22 ,

Due to the predetermined design of the rivet head 26 a uniform as possible loading of the entire rivet head is achieved, so that the rivet described here at the same load, compared with a riveted joint from the prior art, has a significantly higher life.

Through the depression 16 becomes the riveted joint for the manufacture of the assembly 20 manufactured with the least possible cost of materials. By completely closing the opening 24 With plastic material is on the one hand, a tightness of the component 20 reached at the junction. Furthermore, the bending strength is in the vicinity of the opening axis A of the component 20 elevated.

3 shows a plan view of a section through the rivet connection of the assembly 2 along in the plane of the sheet metal part surface 22a lying sectional plane III-III in 2 , In particular, the extension of the contact surface 36 the plastic part 10 on the sheet metal part 22 and their subareas 36a . 36b ,

Claims (11)

Assembly comprising a plastic part ( 10 ) and a sheet metal part connected thereto ( 22 ), wherein the sheet metal part ( 22 ) and the plastic part ( 10 ) so by plastically deforming one piece with the plastic part ( 10 ) formed rivet dome ( 12 ) are joined together that plastic material of the plastic part ( 10 ) an opening ( 24 ) of the sheet metal part ( 22 ) along an enforcement direction (F) and penetrated with a resulting from the plastic deformation rivet head ( 26 ), wherein an inner edge ( 30 ) of the opening ( 24 ) is defined as the opening ( 24 ) circumscribing and in a plane orthogonal to the direction of enforcement (F) on a sheet metal part outer surface ( 22b ) lying closed curve with the smallest surface area, characterized in that the rivet head ( 26 ) has the following characteristic surfaces: a virtual closed inner load surface ( 38 ), which extend from the inner edge ( 30 ) of the opening ( 24 ) extends in the radial direction to an opening axis (O), which the center of gravity of the opening ( 24 ) and in the direction of enforcement (F), and a virtual closed rivet head shear surface ( 32 ), which are opposite to the direction of enforcement (F) of an outer surface ( 26a ) of the rivet head ( 26 ) to the inner edge ( 36 ) of the opening ( 24 ) and orthogonal to the direction of penetration (F) along the inner edge ( 30 ) of the opening ( 24 ), and wherein the sheet metal part has the following characteristic area: a virtual closed sheet-metal part shear surface ( 35 ) extending along the radially outer edge ( 27 ) of the contact surface ( 34 ) of the rivet head ( 26 ) at the rivet head ( 26 ) facing outer surface ( 22a ) of the sheet metal part ( 22 ) and in the direction of enforcement (F), wherein the rivet head ( 26 ) is formed such that the surfaces of each of the inner load surface ( 38 ), the rivet shear surface ( 32 ) and the sheet metal part shear surface ( 35 ) depending on one on the connection of plastic part ( 10 ) and sheet metal part ( 22 ) exerted predetermined load and in dependence on predetermined material properties of the plastic part ( 10 ) and the sheet metal part ( 22 ) are dimensioned. An assembly according to claim 1, characterized in that the opening ( 24 ) of the sheet metal part ( 22 ) is closed by plastic material An assembly according to claim 1 or 2, characterized in that in an enforcement direction (F) on the assembly ( 20 ) applied tensile load the percentage utilization of tensile strength of the plastic part ( 10 ) in the inner load surface ( 38 ), the percentage utilization of the shear load capacity of the plastic part ( 10 ) in the virtual rivet head shear surface ( 32 ), and the percentage utilization of the shear load capacity of the sheet metal part ( 22 ) in the sheet metal part shear surface ( 35 ) are substantially the same size. Assembly comprising a plastic part ( 10 ) and a sheet metal part connected thereto ( 22 ), wherein the sheet metal part ( 22 ) and the plastic part ( 10 ) so by plastically deforming one piece with the plastic part ( 10 ) formed rivet dome ( 12 ) are joined together that plastic material of the plastic part ( 10 ) an opening ( 24 ) of the sheet metal part ( 22 ) along a passage tion direction (F) interspersed and with a resulting from the plastic deformation rivet head ( 26 ) engages behind, characterized in that a the opening ( 24 ) bordering section ( 28 ) of the sheet metal part ( 22 ) with respect to the surrounding sheet in the direction of enforcement (F) is angled (edge stop). Assembly according to claim 4 with the features at least one of the claims 1 to 3. An assembly according to claim 4 or 5, wherein an inner edge ( 30 ) of the opening ( 24 ) is defined as the opening ( 24 ) circumscribing and in a plane orthogonal to the direction of enforcement (F) on a sheet metal part outer surface ( 22b ) lying closed curve with the smallest surface area, characterized in that the assembly comprises as characteristic surfaces: an inner pressure surface ( 37 ), which is defined as the projection of the contact surface ( 36 ) of the rivet head ( 26 ) on the sheet metal part ( 22 ) in a Schubbelatungsrichtung (S) on a Schubbelastungsrichtung (S) orthogonal projection plane (PE1) and a virtual closed inner load surface ( 38 ), which extend from the inner edge ( 30 ) of the opening ( 24 ) extends in the radial direction to an opening axis (O), which the center of gravity of the opening ( 24 ) and in the direction of enforcement (F), wherein the rivet head ( 26 ) and the sheet metal part are formed such that the surfaces of each of the inner pressure surface ( 37 ) and the internal load surface ( 38 ) depending on one on the connection of plastic part ( 10 ) and sheet metal part ( 22 ) exerted predetermined load and in dependence on predetermined material properties of the plastic part ( 10 ) and the sheet metal part ( 22 ) are dimensioned. An assembly according to claim 6, characterized in that at an orthogonal to the direction of enforcement (F) on the assembly ( 20 ) applied shear load the percentage utilization of the shear load capacity of the plastic part ( 10 ) in the virtual load area ( 38 ) and the percentage utilization of the permissible surface pressure of the sheet metal part ( 22 ) are substantially the same size in the inner pressure surface. Assembly comprising a plastic part ( 10 ) and a sheet metal part connected thereto ( 22 ), wherein the sheet metal part ( 22 ) and the plastic part ( 10 ) so by plastically deforming one piece with the plastic part ( 10 ) formed rivet dome ( 12 ) are joined together that plastic material of the plastic part ( 10 ) an opening ( 24 ) of the sheet metal part ( 22 ) along an enforcement direction (F) and penetrated with a resulting from the plastic deformation rivet head ( 26 ), wherein an inner edge ( 30 ) of the opening ( 24 ) is defined as the opening ( 24 ) circumscribing and in a plane orthogonal to the direction of enforcement (F) on a sheet metal part outer surface ( 22b ) lying closed curve with the smallest surface area, characterized in that the rivet head ( 26 ) its maximum extent in the direction of enforcement (F) over the inner edge ( 30 ) of the opening ( 24 ) and its maximum extent orthogonal to the direction of enforcement (F) in the contact surface ( 34 ) at the rivet head ( 26 ) facing side ( 22b ) of the sheet metal part ( 22 ) having. Assembly according to claim 8 with the features at least one of the claims 1 to 7. Assembly according to one of the preceding claims, characterized in that the rivet head ( 26 ) is rotationally symmetric. Assembly according to one of the preceding claims, characterized in that the plastic part ( 10 ) on his from the rivet head ( 26 ) facing away in the region of the opening ( 24 ) a recess ( 16 ) having.