DE102014201871A1 - Resistance welding element with stamping rings for sealing the joint and method for producing a composite component using such resistance welding elements - Google Patents

Abstract

The invention relates to a resistance welding element (100) for producing a resistance welding connection between components (10, 20), in particular of extraneous materials, with an element shaft (110) extending axially with respect to a longitudinal central axis (L) of the resistance welding element (100), and with an element head (120) integrally formed on a shaft end and projecting beyond the element shaft (110) in the radial direction (r), wherein it is provided that the element head (120) has on its underside at least two rigid, closed circumferential bearing rings (131, 132) which protrude in the axial direction (L) from the bottom and in the radial direction (r) are spaced from each other. The invention further relates to a method for producing a component composite (10, 20), in particular for a motor vehicle body, using at least one such resistance welding element (100).

Description

The invention relates to a resistance welding element for producing a resistance welding connection between components, in particular between components made of dissimilar materials, according to the features in the preamble of claim 1.

The invention further relates to a method for producing a component composite using at least one such resistance welding element.

Resistance welding using a resistance welding member functioning as an auxiliary joining member is known in the prior art. This is represented on the representative DE 10 2004 025 492 A1 the same applicant, in which various embodiments of resistance welding elements are shown. The prior art is in addition to the DE 10 2007 036 416 A1 pointed.

The invention has for its object to provide a resistance welding element that has at least one associated with the prior art disadvantage or at least only to a reduced extent.

This object is achieved by a resistance welding element according to the invention with the features of claim 1. With a non-independent claim, the solution of the problem also extends to a method for producing a composite component using at least one resistance welding element according to the invention. Preferred developments and embodiments of the invention will become apparent analogously for both subject invention both from the dependent claims and from the following explanations.

A resistance welding element according to the invention comprises a shaft or element shaft extending axially with respect to a longitudinal center axis of the resistance welding element and a head or element head integrally formed on a shaft end of the shaft and projecting beyond the element shaft in the radial direction (that is transversely to the longitudinal center axis). The element head has at its (adjacent to the element shaft) underside at least two rigid, closed circumferential embossing rings which project in the axial direction from the bottom or project and which are spaced apart in the radial direction.

During the setting process or during setting of the resistance welding element according to the invention and / or during the subsequent resistance welding or during the subsequent resistance welding process, the rigid stamping rings formed on the underside of the element head are impressed or impressed into the surface of the head-side component. The stamping rings can also be referred to as ring collars or compression rings. The embossing rings are rigid, which means that they have sufficient rigidity or strength so that they can be impressed or impressed into the surface of the head-side component. Such rigidity can result from the material condition and / or the geometric design.

The embossed rings embossed into the surface of the head-side component on the underside of the element head (or in the annular surface surrounding the element shaft on the underside of the element head) subsequently lead to a targeted sealing of the joint. The radially outer embossing ring causes an outer seal, the example. The penetration of corrosive media such. As moisture and / or dirt in the gap (lower head gap) between the element head and head-side component prevented. The radially inner stamping ring effects an internal seal, for example the outward penetration of gases (for example so-called zinc degassing with risk of formation of zinc bubbles) during the resistance welding process (eg as a consequence of the evaporation of a galvanic coating) or an optional one used adhesive prevented. With a resistance welding element according to the invention can be achieved in a sense a double seal, both against gases and against liquids, at the joint. The seal is achieved without additional means or measures between the element head and the head-side component. As a result, the overall corrosion behavior of the joint compound is improved, whereby there is a risk of contact corrosion in the event of moisture ingress or ingress, especially in the case of extraneous materials. Another advantage is the cathodic dip coating, because the double seal also allows a non-porous coating at the joint. In particular, it is also possible to achieve a seal against phosphating solution or lye during the preceding phosphating.

The embossing rings, which are in particular circularly closed around the element shaft, can be designed with different cross-sectional geometry and are preferably designed with identical cross-sectional geometry. Preferably, a bead-like cross-sectional geometry is provided as explained in more detail below. Preferably, the embossing rings in the radial direction are uniformly spaced from each other, resulting in a concentric arrangement. Preferably, the resistance welding element according to the invention is rotationally symmetrical with respect to its longitudinal central axis, which also requires a concentric arrangement of the embossing rings.

Preferably, the radially outer embossing ring extends on the underside outer edge of the element head, d. H. along the outer contour of the element head of the resistance welding element according to the invention. The resulting sealing directly on the outer contour reliably prevents any penetration of corrosive media into a lower-head gap.

Preferably, the stamping rings are formed edge-free, which in particular succeeds by Übergangsverrundungen (entry and / or Auslaufradien) or bevels on the ring base and / or by rounding or chamfering on the annular end face. The edge-free formation of the embossing rings can prevent or at least reduce the occurrence of notch stresses. Furthermore, the flow of material on the head-side component is less impeded during the setting of the resistance-welding element and / or during the subsequent resistance welding process, so that the material of the head-side component can form-fit around the embossing rings by plastic deformation, whereby the desired sealing is improved. A heating occurring during the resistance welding process, in particular in combination with an electrode force, can improve the achievable seal.

The stamping rings preferably have a minimum height (protrusion from the underside of the element head in the axial direction) of 0.2 mm and in particular 0.3 mm. The minimum height of the embossing rings ensures a reliable seal at the joint, even if the element head is not flat on the surface of the head-side component rests, which, for example, the result of tolerance-related axial skew (of, for example. Up to 3 °) when setting and / or resistance welding can be. The minimum height of the embossing rings thus also allows a tilting tolerance.

The stamping rings preferably have a maximum height of 0.5 mm and in particular 0.4 mm. The maximum height of the embossing rings limits the press-in or embossing depth in the surface of the head-side component and also allows for easier manufacturability of a resistance welding element according to the invention, in particular by reshaping production, as explained in more detail below.

The element shaft of a resistance welding element according to the invention may be formed at its free end facing away from the element head with a punching edge (or the like), for generating a through opening in the head-side component by separating out a punching waste or -butzens, and / or with a Schweißbuckel (or the like).

A resistance welding element according to the invention is preferably produced in one piece (that is, in one piece or in one piece). This is preferably produced by forming a metal material and in particular a steel material. The resistance-welding element according to the invention is thus preferably a forming part which has been produced, for example, by extrusion or cold-forging.

• – Bereitstellen (wenigstens) eines ersten blechartigen Bauteils, das insbesondere aus einem Nicht-Eisen-Werkstoff, wie bspw. Aluminium oder CFK, gebildet ist;
• – Setzen wenigstens eines erfindungsgemäßen Widerstandsschweißelements durch vorzugsweise vorlochfreies Einpressen in das erste Bauteil an einer vorgesehenen Fügestelle (der Elementkopf des Widerstandsschweißelements dient hierbei zum Aufbringen der Setz- bzw. Einpresskraft), wobei dessen Elementschaft das erste Bauteil an der vorgesehenen Fügestelle (vollständig) durchdringt und die Unterseite des Elementkopfs in Anlage mit der außenseitigen bzw. kopfseitigen Oberfläche des ersten Bauteils gelangt und sich hierbei die Prägeringe an der Unterseite des Elementkopfs in diese Oberfläche am ersten Bauteil einprägen bzw. eindrücken; und
• – Positionieren und Ausrichten des ersten Bauteils relativ zu wenigstens einem zweiten Bauteil und Widerstandsverschweißen (durch Ausführen eines Widerstandsschweißvorgangs, wobei der Elementkopf des Widerstandsschweißelements zur direkten oder indirekten Anlage einer Schweißelektrode dienen kann) des vom Elementkopf wegweisenden freiliegenden Schaftendes mit dem zweiten, insbesondere aus einem Eisen-Werkstoff gebildeten, Bauteil, wobei sich (in bekannter Weise) eine Schweißlinse zwischen den Bauteilen ausbildet und eine stoffschlüssige Verbindung zwischen dem Widerstandsschweißelement und dem zweiten Bauteil herbeigeführt wird und das erste Bauteil durch einen mit dem Elementkopf herbeigeführten Form- und Kraftschluss fixiert wird.

The method according to the invention for producing a component composite, in particular for a motor vehicle body, comprises at least the following steps:

• - Providing (at least) a first sheet-like component, which is in particular made of a non-ferrous material, such as. Aluminum or CFRP, is formed;
• - Setting at least one resistance welding element according to the invention by preferably pre-hole-free pressing into the first component at a designated joint (the element head of the resistance welding element serves to apply the setting or pressing force), wherein its element shaft, the first component at the intended joint (completely) penetrates and the underside of the element head comes into abutment with the outside or head-side surface of the first component and in this case impress or press the embossing rings on the underside of the element head into this surface on the first component; and
• Positioning and alignment of the first component relative to at least one second component and resistance welding (by performing a resistance welding operation, wherein the element head of the resistance welding element can serve for direct or indirect abutment of a welding electrode) of the exposed shaft end facing away from the element head with the second, in particular iron -Material formed component, wherein (in a known manner) forms a weld nugget between the components and a cohesive connection between the resistance welding element and the second component is brought about and the first component is fixed by a brought about with the element head positive and frictional connection.

In an analogous manner, a plurality of superimposed first sheet-like components can be joined with at least one second component, which should be included in the inventive method.

The invention will be further described by way of example and not limitation with reference to the schematic and not to scale figures. The features shown in the figures and / or explained below may, regardless of the illustrated and / or explained combinations of features, be general features of the invention.

1 shows a sectional view of a joint connection or resistance welded connection produced by the method according to the invention.

2 shows in a sectional view that for the joint of the 1 used resistance welding element according to the invention.

3 shows in a sectional view another embodiment of a resistance welding element according to the invention.

1 shows one with the inventive method and using a resistance welding element according to the invention 100 manufactured resistance weld between two components 10 and 20 , The rotationally symmetrical resistance welding element 100 has an elemental 110 which is relative to a longitudinal center axis L of the resistance welding element 100 extends axially, and an integrally formed on the upper end of the shaft element head 120 on, with the element head 120 the elementary 110 projected transversely to the longitudinal central axis L in the radial direction r. The element head 120 is designed as a flat head.

The elementary system 110 the resistance welding element 100 penetrates or passes through the upper component 10 and is at its bottom, from the element head 120 groundbreaking end foot side with the lower component 20 welded. It is a point welded joint. The welding zone is designated S. The upper head-side component is preferably used 10 around an aluminum sheet metal part and at the lower foot-side component 20 around a sheet steel part. Between the components 10 and 20 Optionally an adhesive layer 30 to be available. Furthermore, at least one of the components 10 and or 20 , Especially in the contact area with the other component, a coating, such as, for example, a galvanic corrosion protection coating, have.

According to the invention at the top of the component 10 facing bottom of the element head 120 two closed circumferential rings 131 and 132 formed in the axial direction L and in the extension direction of the shaft 110 protrude from the bottom or protrude and are spaced apart in the radial direction r. The stiff or difficult to deform deformed embossing rings 131 and 132 have during setting or pressing the resistance welding element 100 and / or in the subsequent resistance welding in the outside surface 11 of the upper component 10 imprinted and cause a seal of the joint. The radially outer stamping ring 132 causes over its entire circumference an outer seal, which prevents the penetration of corrosive media (as illustrated by the arrow A) in the lower head gap. The radially inner stamping ring 131 causes over its entire circumference an inner seal, for example, the outward-penetration of gases and / or adhesive (as illustrated by the arrow B) prevents.

2 shows the resistance welding element 100 of the 1 in unwelded condition. The two stamping rings 131 and 132 are formed with identical bead-like cross-sectional geometry. The stamping rings 131 and 132 may also be formed with a different cross-sectional geometry and / or with different cross-sectional geometries. The elementary system 110 is at its free end or foot side with a molded Schweißbuckel 117 (or the like) formed. The circumferential outer edge 115 at the lower free shaft end is formed as a cutting or punching edge.

The radially outer stamping ring 132 runs essentially along the outer contour of the element head 120 , The radial position of the radially inner stamping ring 131 is only an example. The radially inner stamping ring 131 Therefore, it can also be closer to the radially outer stamping ring 132 or closer to the elementary 110 are located. The head-side circular ring surface between the inner stamping ring 131 and the elementary 110 serves as a flat stop or contact surface when setting the resistance welding element 100 ,

The concentric stamping rings 131 and 132 at the bottom of the element head 120 have a height h2 of 0.2 mm to 0.5 mm (this corresponds to the maximum embossing depth) and are provided at their ring bases with transition roundings in the form of inlet and outlet radii R1. The rounding radius R1 is, for example, 0.05 mm to 0.15 mm and in particular about 0.1 mm. The ring end faces are also provided with fillets. The rounding radius R2 for the annular end faces is, for example, 0.15 mm to 0.25 mm and in particular approximately 0.2 mm. Also the transition between the elementary 110 and the bottom of the element header 120 is formed with a rounding, wherein the rounding radius R3 in particular corresponds to the rounding radius R2 at the annular end faces.

In the resistance welding element 100 it is in particular a one-piece formed from steel material formed part, which can be inexpensively, for example. Made of a wire starting material piecefall on a forming machine. The head diameter D of the shown resistance welding element 100 is, for example, 4.0 mm to 15.0 mm. The head height h1 is, for example, 0.3 mm to 3.0 mm. The elementary or nominal diameter d is, for example, 1.5 mm to 10.0 mm. The total height or axial length H is, for example, 1.8 mm to 8.0 mm. These are possible range indications within which the dimensions in question can preferably be dimensioned.

In the 3 shown embodiment possibility of a resistance welding element according to the invention 100 has a third embossing ring 133 on, which is approximately in the middle between the radially inner stamping ring 131 and the radially outer ferrule 133 is arranged. Notwithstanding the in 2 embodiment shown have the stamping rings 131 . 132 and 133 a rounded or optionally also chamfered wedge or trapezoidal cross-sectional geometry, as can be seen from the enlarged detail. The elementary system 110 is at its free end or foot side also with a molded Schweißbuckel 117 and a circumferential punching or cutting edge 115 educated.

LIST OF REFERENCE NUMBERS

10

Upper (head-side) component

11

outside surface

20

lower (foot-side) component

30

adhesive

100

Resistance welding element

110

element shaft

115

punching edge

117

weld projection

120

element head

131

inner stamping ring

132

outer stamping ring

133

middle stamping ring

A

outer seal

B

inner seal

D

Head diameter

H

axial height

L

Longitudinal central axis

R1

Rounding radius

R2

Rounding radius

R3

Rounding radius

S

welding zone

d

Shaft diameter

r

radial direction

h1

head height

h2

Ferrule height

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004025492 A1 [0003]
• DE 102007036416 A1 [0003]

Claims (10)

Resistance welding element ( 100 ) for producing a resistance welding connection between components ( 10 . 20 ), in particular of dissimilar materials, with an elementary shaft ( 110 ), which with respect to a longitudinal center axis (L) of the resistance welding element ( 100 ) extends axially, and with an integrally formed on a shaft end element head ( 120 ), the elementary ( 110 ) in the radial direction (r) dominated, characterized in that the element head ( 120 ) on its underside at least two rigid, closed circumferential embossing rings ( 131 . 132 . 133 ) which project in the axial direction (L) from the underside and in the radial direction (r) are spaced from each other. Resistance welding element ( 100 ) according to claim 1, characterized in that this is rotationally symmetrical with respect to its longitudinal central axis (L). Resistance welding element ( 100 ) according to claim 1 or 2, characterized in that the radially outer embossing ring ( 132 ) along the outer contour of the element head ( 120 ) runs. Resistance welding element ( 100 ) according to one of the preceding claims, characterized in that the stamping rings ( 131 . 132 . 133 ) are formed edge-free. Resistance welding element ( 100 ) according to one of the preceding claims, characterized in that the stamping rings ( 131 . 132 . 133 ) have a minimum height of 0.2 mm. Resistance welding element ( 100 ) according to one of the preceding claims, characterized in that the stamping rings ( 131 . 132 . 133 ) have a maximum height of 0.5 mm. Resistance welding element ( 100 ) according to any one of the preceding claims, characterized in that the elementary ( 110 ) at its from the element head ( 120 ) groundbreaking free shaft end with a punched edge ( 115 ) and / or with a welding hump ( 117 ) is trained. Resistance welding element ( 100 ) according to one of the preceding claims, characterized in that it is made in one piece. Resistance welding element ( 100 ) according to one of the preceding claims and in particular according to claim 8, characterized in that this is produced by deforming production of a metal material and in particular a steel material. Method for producing a component composite, in particular for a motor vehicle body, comprising the following steps: - providing a first sheet-like component ( 10 ); - setting at least one resistance welding element ( 100 ) according to one of the preceding claims by being pressed into the first component ( 10 ) at an intended joint, the elementary body ( 110 ) the first component ( 10 ) penetrates and the underside of the element head ( 120 ) in contact with the outside surface ( 11 ) of the first component ( 10 ) and thereby the stamping rings ( 131 . 132 . 133 ) at the bottom of the element head ( 120 ) into this surface ( 11 ) imprint; and - positioning and aligning the first component ( 10 ) relative to at least one second component ( 20 ) and resistance welding of the element head ( 120 ) groundbreaking exposed shaft end with the second component ( 20 ).

Images