EP3156148A1 - Method for connecting at least two components by means of a self-piercing rivet device - Google Patents

Abstract

The invention relates to a method and a punch rivet device (101) for connecting at least two components (11, 12), wherein the at least two components (11, 12) are arranged between a punch (15) and a counter holder (18) of the punch rivet device (101) be introduced, wherein between the counter-holder (18) and a counter-holder facing member (12) of the at least two components, a film (41), wherein between the punch (15) and a punch facing the component (11) of the at least two Components arranged rivet (20) by means of the punch (15) in the at least two components (11, 12) is pressed by the punch (15) is acted upon by a force (F).

Description

description

The present invention relates to a method and a punch riveting apparatus for connecting at least two components.

State of the art

Punching riveting methods are used to connect at least two components that are particularly flat in a connection region (joining partner). A punch riveting method is characterized in that a pre-punching of the components to be joined together is not required. Rather, a punch rivet is pressed by means of a punch or a punch tool in the at least two components, being ensured by a correspondingly shaped counter-holder, for example. In the form of a die, which cooperates with the punch tool, that the rivet or the components in a certain Deforming manner to produce a positive and positive connection between the components.

Furthermore, for example, from the EP 2 318 161 B1 or the DE 10 2014 203 357 A1 So-called. Ultrasonic punch riveting known, in which a vibration generator, such as. An ultrasonic generator is used to enable one or more components when connecting the components in vibration. By this vibration, for example, the expended force is reduced to push the rivet.

Disclosure of the invention

According to the invention, a method and a punch riveting apparatus for connecting at least two components with the features of the independent patent claims are proposed. Advantageous embodiments are the subject of the dependent claims and the following description.

Advantages of the invention

In the context of the invention, a film is introduced in a punch riveting process between the counter-holder and a component facing the counter-holder in order to avoid direct contact between counter-holder and component. The film used acts in particular as a sliding or protective film and in particular is sufficiently ductile or elastically deformable in order to conform to the counter-holder during the punch riveting process.

A counter-holder for a punch riveting device is usually milled or turned, hardened and possibly mechanically polished or ground. The counter-holder thus has a relatively rough surface, on which material can adhere from a component abutting the punch riveting process. This is especially the case, for example, when punching riveting soft materials such as aluminum. The introduced foil prevents direct contact between the component and the counterholder so that material can no longer adhere. The service life of the counter-holder is increased (thereby lengthening the counterholder change intervals) and the reproducibility of the rivet connections is improved by avoiding buildup in the counter-holder.

Particularly advantageous is the introduction of a film for punch riveting with a vibrator, eg. An ultrasonic generator. In such punch riveting devices, a portion of the punch riveting apparatus is vibrated during the punch riveting operation so that the rivet can be more easily pressed into the components to be connected. Just by the vibrations or the ultrasound, a relative movement can arise between the counter-holder and the component adjacent thereto, through which not only adhesions of material, but, for example, also alloys can occur in conventional counter-holders. In the invention, this is no longer or at least hardly the case. Such punch riveting have special advantages in automotive lightweight body construction, since the vibration or ultrasonic punch riveting facilitates with the appropriately designed equipment many joining tasks in the field of material mixing and new material thickness combinations possible. However, a punch riveter with vibration support may also be used to advantage in other areas (such as in the aerospace industry or in cable car and gondola construction) and / or for joining other materials. By means of punching riveting, the process forces required for the riveting process, usually very high, are considerably reduced. This results in particular process advantages (such as the improvement of the cutting process or the material separation during punching, the change, the plastic deformation capacity of material (eg Al / Mg sheet metal or die-cast) and the avoidance of collapsing rivet elements), which extends the rivetable material spectrum can be. Preferably, the film is provided as sheets (ie, singulated pieces) or as rolls (ie, endless web). A preferred punch riveting apparatus has an associated foil insertion device in order to introduce the foil sheets or foil web between the component and the counterholder.

Preferably, the foil has metal. A metal foil is relatively robust and tear-resistant and can reliably prevent direct contact between component and counter-holder. Alternatively or additionally, the film may comprise plastic (e.g., PTFE (Teflon)). Plastic is usually less expensive than metal and easier to handle due to its low density.

Particularly suitable is the use of a release-containing film, such as e.g. a ceramic or polymer based (e.g., PTFE) coated (metal) foil), which performs the function of a permanent separation of the original 'mating component' contact mating. Due to the isolation of the contact pairing between the counterholder and the component, adhesions in the counter holder are avoided.

Furthermore, suitable lubricant films (for example, (metal) film systems with graphite, wax or oil coating) on the contact pair between counter-holder and component provide additional sliding assistance and thereby achieve a friction reduction coupled with a Fügekraftreduktion.

Preferably, each film section (ie, during the joining of the at least two components with the counter-holder in contact portion of the film) is used only for a single punch riveting operation. In this way you can prevent a through a punch riveting operation, possibly damaged or contaminated film section is reused and leads to damage or contamination of the component and / or the counter-holder.

In a further embodiment, the film can also be used as corrosion protection on the product, i. the portion of the film remains on the component. As an example, a thin stainless steel foil (e.g., No. 1.4301 or 1.4303 or 1.4567), with about 25 μm film thickness) or another corrosion resistant foil could be used.

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

The invention is illustrated schematically with reference to an embodiment in the drawing and will be described in detail below with reference to the drawing.

figure description

FIGS. 1a to 1d

show a punch riveting apparatus at various stages of a punch riveting operation.

FIG. 2

shows schematically in a side view a section of a punch riveting device according to a first embodiment of the invention with a foil sheet.

FIG. 3

shows schematically in a side view a section of a punch riveting device according to a second embodiment of the invention with a film roll.

Detailed description of the drawing

In the FIGS. 1a to 1d a punch riveting apparatus 10 is shown at various stages of performing a punch riveting process. The punch riveting apparatus 10 has a punch 15, which for example has a round cross section.

The punch 15 is radially surrounded by a sleeve-shaped hold-down 16 and arranged movable relative to this in the longitudinal direction. In particular, the punch 15 is coupled to a drive, not shown here, for example a hydraulic or pneumatic drive, which serves to apply a force F required to press a rivet 20 into the two components 11, 12.

Also, the hold-down 16 is adapted to press against the surface of the die 15 facing member 11 with a hold-down force. For this purpose, for example, a separate drive can be provided. However, the hold-down can also be coupled to the drive of the punch 15, for example by means of a spring.

On the stamp 15 and the hold-down 16 opposite side of the two components 11, 12 is an inventive counter-holder 18, which acts as a die here, arranged. The punch 15 and the die 18 are movable relative to each other in the direction of a longitudinal axis 19, in the direction of which also the hold-down 16 are arranged to be movable. The hold-down 16 and the die 18 serve to clamp or compress the two components 11, 12 between the hold-down 16 and the die 18 during processing by the punch 15. The die 18 has, on the side facing the component 12, a region 21 with a flat surface, from which a trough-shaped or recess 22 extends.

In the Figures 2 and 3 is shown between the component 12 and the die 18 introduced film.

The rivet 20 preferably consists of a material which is harder than the materials of the two components 11, 12, at least in the region of the rivet shank 24. The planar top side 26 facing away from the component 11 is arranged in operative connection with the ram 15, which is secured to the top side 26 of FIG Rivet 20 is flat.

The punch 15 is operatively connected to a vibration generator 30 for generating vibrations. In particular, by means of the vibration generator 30, ultrasonic vibrations with an amplitude (distance between maximum positive and negative amplitude of a vibration) between 10 .mu.m and 110 .mu.m (or an amplitude between 5 .mu.m and 55 .mu.m) and a frequency between 15 kHz and 35 kHz are generated.

These vibrations are coupled by the vibrator 30 via the punch 15 in the rivet 20. The coupling-in direction of the vibrations of the vibration generator 30 can take place, for example, parallel to the longitudinal axis 19, that is to say parallel to the joining direction of the rivet 20 into the components 11, 12

In the FIG. 1a Phase shown represents a beginning of the Stanznietverfahrens in which the rivet shank 24 comes into operative connection with the top of the component 11. In this case, the punch 15 is pressed with the force F against the stamp 15 facing member 11.

In an in FIG. 1b shown further phase, ie during the course of the riveting process and under support of the vibrations coupled into the components 11, 12, the rivet shank 24 initially cuts or punches into the component 11. In this case, the two components 11, 12 are plastically deformed, wherein the recess 22 facing the component 12 is pressed in the corresponding areas in the recess 22.

During the further movement path or the further downward movement of the rivet 20 according to the Figure 1c the rivet shank 24 is spread outwards in the region of the recess 22, whereby the two components 11, 12 are securely connected to each other in the axial direction in a positive and non-positive manner.

It can be seen that according to the Figure 1d , which shows the end position of the rivet 20, the rivet shank 24 does not protrude from the component 12 or does not completely penetrate it.

After the rivet 20 in the Figure 1d has reached the end position, in which the top 26 of the rivet 20 at least approximately flush with the top of the component 11, then the punch 15 is again moved by the components 11, 12 in the opposite direction upwards.

In the Figures 2 and 3 two preferred embodiments of a punch riveting device according to the invention are shown in fragmentary form in a schematic side view or sectional view and designated by 101 and 102, respectively. The elements corresponding to those of the punch riveting device 10 FIG. 1 correspond, are provided with the same reference numerals and will not be explained again at this point.

The punch riveting devices 101 and 102 are shown in a state in which the die 18 is shown downwardly from each of the components 11 and 12 to be connected. Usually, however, the die is not movable relative to a frame (for example, pliers) of the punch riveting apparatus, but the punch and the downholder.

In each case between the die 18 facing the component 12 and the die 18, a film 41 and 42 is introduced. In the punch riveting apparatus 101, the film 41 is provided as sheet goods, whereas in the punch riveting apparatus 102, the film 42 is provided as a roll product.

In the punch riveting device 101, separated film sheets 41 are accordingly introduced between component 12 and die 18, in order to avoid direct contact between component 12 and die 18 during the punch riveting process. For the film sheets 41, a film insertion device 411 is provided, which introduces the separated film sheets, for example by means of rollers or gripping arms between the component 12 and the die 18.

In contrast to this, the punch riveting device 102 has a film insertion device 421 which, in the example shown, has a plurality of rollers over which the web-shaped film (film web) 42 is guided. Specifically, an unwind roll 422, two idler rolls 423, and a take-up roll 424 are shown.

The illustrated embodiments have in common that a respective foil section, which comes into contact with the die 18 in a punch riveting operation, is used only for a single punch riveting operation and after this punch riveting operation the foil section between the component 12 and the die 18 is removed again. In the punch riveting apparatus 101, the portion A may each comprise an entire foil sheet 41, in the punch riveting apparatus 102, the portion each comprises a portion A on the foil web 42.

Claims (11)

Method for connecting at least two components (11, 12) by means of a punch rivet device (101, 102), wherein the at least two components (11, 12) are arranged between a punch (15) and a counter holder (18) of the punch rivet device (101, 102) be introduced, wherein between the counter-holder (18) and a counter-holder facing member (12) of the at least two components, a film (41, 42), wherein between the punch (15) and a punch facing the component (11) at least two components arranged rivet (20) by means of the punch (15) in the at least two components (11, 12) is pressed by the punch (15) is acted upon by a force (F). The method of claim 1, wherein the foil (41, 42) comprises metal and / or plastic. A method according to claim 1 or 2, wherein the film (41, 42) is provided as sheets or rolls. Method according to one of the preceding claims, wherein a section (A) of the film (41, 42) which is in contact with the counter-holder (18) during the joining of the at least two components (11, 12) is used only for a single stamped riveting operation. Method according to claim 4, wherein the portion (A) of the film (41, 42) remains on the component (12) of the at least two components facing the counter-holder (18). Method according to one of the preceding claims, wherein the film (41, 42) on one or both sides separating and / or lubricant-afflicted. Method according to one of the preceding claims, wherein at least one component (11, 12, 15, 18, 20) involved in pressing in of the rivet (20), in particular the punch (15), is vibrated when pressed in by means of a vibration generator (30) , Method according to Claim 7, wherein a sound generator, in particular an ultrasound generator, is used as the vibration generator (30). Punching riveting device (101, 102) for connecting at least two components (11, 12), with a punch (15) and a counter-holder (18), wherein the at least two components (11, 12) between the punch (15) and the counter-holder ( 18) can be arranged with a Folieneinbringeinrichtung (411, 412) which is adapted to a film (41, 42) between the counter-holder (18) and a counter-holder facing component (12) of the at least two components to bring. A punch riveting apparatus (101, 102) according to claim 9, wherein the film inserting means (411, 412) is further adapted to re-form the film (41, 42) between the backstop (18) and the backstop member (12) of the at least two components to remove. A punch riveting apparatus (101, 102) according to claim 9 or 10, further comprising a vibrator (30) adapted to receive the punch (15), the counterholder (18) and / or at least one of the at least two components (11, 12). to vibrate.

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