DE102009002078A1 - Connecting device for connecting mudguard with e.g. door strut, has screw whose external thread is inserted via internal thread of opening in non-cutting deformation state, where screw exhibits screw head and threaded shaft - Google Patents

Abstract

The device (1) has a screw exhibiting a screw head and a threaded shaft that is provided with an external thread and a plate (2). The plate is provided with a lowering device (6), and an opening (5) is formed in the lowering device. The screw intervenes with the external thread in the opening of the plate, where the opening exhibits an internal thread. The external thread of the screw is inserted via an internal thread of the opening in a non-cutting deformation state. The lowering device is formed as a hollow truncated cone (7). An independent claim is also included for a repair set for repairing a connecting device.

Description

The The invention relates to a connecting device according to the preamble of claim 1.

For example In the bodywork of a vehicle, the problem is two thin-walled components, like two body panels or a body panel and a hollow profile, to connect with each other. A typical connection example is the connection of a car body panel, such as a fender, with a door or longitudinal spar.

In the patent US 4 659 246 B a connection device of the type mentioned is described, wherein the second plate is supported with the opening edge of its second opening in a screw thread of a Außensägegewindes. This complex connection can easily relax.

The EP 1 398 514 A1 discloses a compound of two sheets, which lie flat against each other at least in the region of their openings. In order to counteract a risk of buckling of the second sheet into the first opening, the opening edge of the second opening is elaborately reinforced.

Of the Invention is therefore based on the object, a connection device of the type mentioned above with improved strength, in particular an improved fatigue strength or fatigue strength, to design.

Of the Invention is also the object of a less expensive To provide connecting device of the type mentioned.

The Asked object is achieved by a connecting device with the Features according to claim 1 and in particular characterized solved that the second opening is an internal thread having, by means of the external thread of the screw when screwing the same in the second opening in a non-cutting forming under displacement of the second opening limiting Material is introduced into the second opening.

Under an internal thread is a complete internal thread understood with more than one thread. Preferably, the Pitch of the external thread of the screw equal or smaller than half the sheet thickness of the second sheet. Consequently can be an internal thread with at least two screw threads be introduced.

at the non-cutting introduction of the internal thread by means of the external thread in particular, it is a burrowing, curling or indenting, in which the internal thread forming material by means of the external thread displaced or pushed away. With the burial, Rolling or indenting is the material of the inner wall of the second opening in the threads of the screw pressed or can, u. a. also depending on the material pairing, under the locally elevated pressures between inner wall and screw into the threads of the external thread flow. This allows the threads almost completely in the area of the second opening or completely filled out. In certain circumstances can be elevated temperature and / or increased Pressures to local welds between external threads and internal thread lead. It can thus over the axial length of the second opening a shape and frictional and at the same time backlash-free connection between the screw shaft and the second plate are manufactured and Thus, the strength, in particular the fatigue strength, the connection can be increased.

By the curling or indenting of the internal thread becomes the material structure Advantageously less than comparatively with a cutting of a Destroys thread, which in particular a fatigue strength the connection can be increased. At one maybe occurring flow of the material during forming the material structure is advantageously minimally disturbed.

in this connection can also with the external thread chipless forming operations occur, which, however, inter alia, of a selected Material pairing external thread internal thread depends. It is advantageous for in particular the second sheet one Material with a relation to that of the screw material lower yield point to choose.

With the onset of abutment of her screw head during the connection process, the external thread with tightening the screw can dig into the already rolled or grooved internal thread further and clamped with the same. It can thus be strengthened the very tight or playless installation of the internal thread of the second opening to the external thread of the screw. There may be local temperature increases at the transition due to increased frictional forces, in particular, when internal thread and external thread tightly against each other, whereby a flow of the materials, in particular the material of the second sheet, can be facilitated. For example, due to local high pressures at the transition between external thread and internal thread flow even at low local temperatures at the transition flow, in particular of the material of the second sheet at this transition, causing the already very close concern or interlocking Of internal thread and external thread can be amplified accordingly at these locations. The external thread of the screw shaft is preferably hardened. Thus, a flow for non-cutting introduction of the internal thread at least predominantly be displaced in the material, which limits the second opening.

Around to establish a permanent connection, only one has to be appropriate for non-cutting insertion of the internal thread suitable screw led the first opening and into the second opening be screwed. Therefore, this connection device is also very good for connecting a sheet to a hollow profile suitable.

The Screw can indirectly in the connecting position with the screw head, for example, via a washer or a spring washer, or directly with the underside pointing in the direction of insertion the screw head facing the direction of insertion Outside of the first sheet rest.

The Lowering may preferably have arched shapes. It is advantageous if the second opening through a wall is limited, which makes an angle larger Has zero to the plane of the second sheet, as this forces transmit torque-free can be. In a possible dome-like Vault shape of the lowering with the second opening in the vaulted center runs the second opening bounding wall little advantageous parallel to the plane of the second Metal sheet to the vault. Contrary runs the Wall at a truncated Rotary hyperbolic vault at an angle of up to 90 ° to the vaulting point, However, this form difficult together with the deep drawing of the second Sheet metal can be produced. As easy to produce and therefore preferred form of subsidence is a hollow frustoconical shape with parallel or substantially parallel bases, a large footprint and a small footprint, considered. This tapers in the connecting position in the insertion direction towards the small base area. The small base area can be formed by the second opening.

This can lead to a mechanical stabilization of the compound, because of the screw shaft transmitted forces immediately above and through the wall of the hollow frustoconical Lowering towards the first plate to be forwarded whereby, depending on the geometry of the cones, the wall only slightly with additional bending moments is loaded perpendicular to the insertion direction. Thus exists hardly any danger of bulging the wall. Furthermore, the forces on a radially outer radius of the second Sheet metal, d. H. to the edge of the larger footprint forwarded to the lowering, whereby the generated at this edge Bending stress can be reduced accordingly. Thus, you can the forces on a larger surface area be transferred to the second sheet or the screw on a larger area of the second sheet support and load this with less pressure. Advantageous At the same time, the lowering is generally used as a reinforcement profile. Thus, by the hollow truncated cone-like formation of the reduction the task is completely solved.

Preferably the pitch angle of the external thread is larger or equal to the angle that the mantle of the hollow truncated cone-like Lowering with the larger base area it includes the same. This supports this Internal thread primarily on the first opening pointing flank of the external thread of the screw, so that the power transmission already at this point at least with a larger component in the direction of extension of the jacket can be done and additional bending moments can be avoided. Furthermore, a material flow when introducing the internal thread against the insertion direction pointing flank relieved.

Because of the axisymmetric arrangement of the second opening in with respect to the insertion direction or with respect an opening axis of the second opening symmetrical Deepening can provide optimal symmetrical force distribution over the cross-sectional plane of the depression take place, which in turn the strength, in particular a fatigue strength of the compound increases.

Of the maximum diameters of the trough-like or vault-like Lowering at the level of the second sheet can be greater or equal to twice the minimum diameter of the second opening be. Furthermore, the maximum depth of the subsidence can be smaller or be equal to half their maximum diameter.

Both openings can be formed circular. You can be arranged in the connecting position in alignment with each other. The first opening can not be circular, but for example be designed as a slot whose smaller diameter preferably about the outer diameter of the screw shank corresponds, so the two openings in the connection position with respect to the hole width of the first opening the smaller diameter be arranged in alignment with each other. With a slot as the first opening can be during assembly a corresponding position correction of the thin-walled components relative to each other.

It can be provided that the geometries of the external thread by rolling or unraveling the internal thread is not or change only slightly.

Thereby the flank of the external thread can not or only slightly be reduced in terms of, for example, the power transmission on the flank is advantageous. This can generally be achieved be that the yield point of the material at least of external thread larger than that of the second opening bounding wall is. Also in this Context is a hardened one mentioned above External thread advantageous. It can also be a material for the second plate with a correspondingly low yield point to be selected. It may be on the inner wall of the second opening a material with reduced yield stress may be provided.

When Materials for the thin-walled components, in particular for the sheets, for example, come microalloyed steels, like ZSTE220 to ZSTE420 with different, strength enhancing Phases, such as DP450 to DP800 with ferrite and martensite or others Qualities, into consideration. This allows for example an insert for burying, curling or indenting internal threads suitable M5 or M6 screws with preferably hardened Thread, which the connecting device cost power.

Of the Diameter of the large base of the lowering is preferably larger than the diameter of first opening and smaller than a diameter of an investment area is in which the screw is directly or indirectly on the facing the insertion direction outside of the first sheet supported. This allows a power flow of the to the first sheet toward ongoing wall of the lowering over the first opening bounding wall of the first sheet done in the screw head, without the first sheet with additional bending moments is charged. This measure can prevent the the first opening bounding wall of the first sheet can be loaded on shear. The first opening Limiting wall can without this measure at this load forming an undesirable sink for lowering bent over. This shear stress can occur when the screw head in the insertion direction and the first sheet towards the current wall of the lowering with respect to the first opening radially outwardly spaced to the screw head against insertion on the first opening bounding wall of the first Sheet supported. To enlarge the Anlagebereiches, in which the screw head in the connecting position on the outside of the first sheet, a can Washer between screw head and outside provided be and / or the screw head in a known manner to the screw shaft towards a flange, for example in the form of a welded Washer, have.

One particular advantage is seen in that under the action of the non-cutting shaping of the internal thread, such as digging, curling or indenting the internal thread on which the second opening bounding wall in and / or against insertion direction respectively an at least partially circumferential bead is formed, in the female thread in or against insertion at least partially extends into it. By means of chipless forming can thus flow or displace the material a bulge in and / or occur against insertion, by means of which the wall thickness of the second sheet in the immediate Near the second opening and thus the axial Length of the internal thread to be increased can. Thus, the strength of the compound can be further increased become.

The non-cutting shaping of the internal thread in the wall of the second opening by means of the external thread can so far to a playless Intermeshing of internal thread and external thread, that the screw settle in the second opening can and can be difficult, the Loosen screw by means of a tool again. The Bead formation described above intensifies this process of setting.

The External thread can be designed self-locking. This proposed Measure can be the fatigue strength of the connection continue to increase. This measure can also favor a setting of the screw. As is known, is to self-locking the pitch of a thread in comparison to a pitch of a thread of a non-self-locking Screw designed smaller. The lower pitch of the Thread also allows a larger Number of threads of the internal thread at the same Sheet thickness, which in turn strength the connection can be increased.

The second opening is preferably flared in the insertion direction. Thus, the second opening may have a front edge or edge region in the insertion direction, at or in which the second opening opens into the side face of the second metal sheet pointing in the direction of insertion, and at the same time have a minimum inner diameter. As a result, the screw with the external thread can first engage at a front edge of the second opening in the direction of insertion and, with relatively little expenditure of force, cut into the second opening in the first opening in the direction of insertion form, ie dig, roll or furrow.

Generally For example, the screw shaft may have a shape that is usually for non-cutting introduction, in particular for rolling or unraveling, an internal thread is suitable, with customary here in tappers Grooves for removing the chips from the thread cutting superfluous are. The screw shaft may be a conically tapered free end with two consecutive in the insertion direction Sections, one in the insertion rear section for inserting the free end into the second opening and a front in the insertion direction section with the Have external thread.

In In another embodiment, the shaft is over the entire area of its external thread to the free end formed conically tapered. This allows the screw to Example in the case of a relaxation further under extension of the internal thread screwed in and fixed again.

The External thread can be in the rear section of the free To be continued at the end. This allows the insertion of the free end to be further facilitated, for example the screw is not exactly in the direction of insertion in the second opening is inserted and over the external thread then centered and with a force impulse can be accelerated in the insertion direction.

The External thread can face each other in the insertion direction following sections, one in the insertion direction front first section for the finished rolling of the internal thread of the second opening and a subsequent insertion in this direction second section for rolling the internal thread of the second opening include. The external thread can be one in the insertion direction rear third section with a pointed thread to its initial Engaging in the side walls of the second opening exhibit. Thus, the external thread with the pointed thread can in its third section dig into the inner wall and thereby train a leadership that ensures that the external thread continues to thread the internal thread properly the second opening rolls in or catches.

It the second section may have a trapezoidal thread, by means of which or those formed by the third section Threads are essentially widened. in this connection At the same time, a depression of the internal thread can take place. Of the first section can turn a pointed thread to the finished molding of the internal thread. Due to the process, the minimum diameter the tip thread of the first section is smaller than the maximum Be the diameter of the tip thread of the third section.

In a development of the connecting device, the two sheets in the connecting position spaced at least in the region of their openings are arranged to each other. As a result, for example, a ventilation be made possible between the sheets.

The first sheet can be spaced in the connecting position to the Bleckebene the second sheet to be arranged fixed to the same. For this can the second plate at its in the connecting position the first Sheet facing side surface near or at the opening edge its second opening at least one opposite to the insertion direction have extending projection. This can at least partially extend around the second opening.

through the projection can be an advantageous stiffening of the second sheet be achieved in the region of the second opening. Intended is that the opening edge of the second opening only a small amount away from the projection. The opening edge may also be preferably integrated in the projection so that the opening edge in an upper, preferably in located at the top of the projection, with which the projection the second sheet surmounted. The projection can be a cross-sectional profile with rounded shapes, d. H. without peaks and edges.

alternative or additionally, the first sheet may be at its in the connecting position Close to the second sheet facing side surface or on the opening edge of its first opening at least a projection extending opposite to the insertion direction at least partially around the first opening is arranged. Are on both sheets such projections provided so they can in the connection position for example, tooth-like interlock or plugged into each other be. As a result, a torsional strength of the connection with respect the longitudinal axis of the screw can be achieved.

advantageously, a plurality of projections are provided with respect to an opening axis of the second opening on a Circumferential circle and are arranged on the same one behind the other. The Projections can be circumferentially equal to each other be spaced. Preferably, the circumferential distances are between projections smaller than the circumferential Extension.

There may be three, preferably in a rotational angle with respect to the insertion of 120 ° to each other or four, preferably in a rotational angle with respect to the insertion of 90 ° to each other arranged projections may be provided.

at Another embodiment of the connecting device can be Insert provided, which is the second opening and in the connecting position in or on a provided, at the insert adapted recess of the second sheet is determinable. Thus, the insert to desired Be set point in the recess of the second sheet. The insert can be stored and, for example, subsequently be inserted into the second plate, in which the recess For example, was also introduced later. Consequently the connection device can also be in case of repair, for example to replace a failed spot weld. For this purpose, the spot weld can be drilled out and can the insert in the insertion behind the second sheet arranged and with tightening the screw against the second sheet to be set. Preferably, the insert is in overlapping Edge regions of insert and recess by means of preferably Spot welding connected to the second plate. The insert may have the projection or the projections. Preferably is the thickness of the insert opposite the rest of the sheet thickness or wall thickness the second sheet or the thin-walled body increased. In the insert can Also similar to other, also stiffening acting elements the lowering and / or the projection or the projections be provided near the second opening.

The allows connection device according to the invention As stated above, a particularly strong connection of two thin-walled body in which the screw in the first opening even to the extent that can when loosening the screw by means of a tool, the internal thread and / or the external thread at least partially so far injured or can be destroyed, that a renewed screwing can only provide insufficient bond strengths. Therefore, a repair kit for repairing the connecting device according to one of the preceding embodiments be provided. This repair kit can be a component with a adapted to the second opening and the internal thread having recess and one in the installed position in the connecting device have front side surface in the insertion direction, the rear side surface in the insertion direction the second sheet in the vicinity of the second opening adapted and to the same for connection to the screw of the connecting device can be applied. The component can with against insertion with led his rear side surface against the recess be and there preferably lie. This can be the rear Side surface be shaped like the recess, so that the component in the connection position preferably also or alone at the side facing in the insertion direction side surface the first sheet or the first thin-walled component supported. The component can as a flanged nut with a disc-shaped edge be formed, wherein the edge of the front side surface of the component. The component can also be a nut be with welded edge.

additionally the repair kit may include a screw with a screw shank, whose length is designed so that the screw shaft properly screwed to the component. This screw can be a conventional preferably self-locking Have external thread.

Especially for a fastening of the first sheet to a hollow profile The repair kit can be a self-winding or self-winding screw self-tapping external thread whose outer diameter preferably larger by a standard size as the previously used in the connecting device and off the connection is loosened screw. By means of the larger ones Screw can, similarly as described in detail above, chipless then a new internal thread in the second opening be introduced.

The The present invention will be described below with reference to several in one Drawing illustrated embodiments closer explained. In the drawing show:

1a to 1c Longitudinal sectional views of a first embodiment of a connecting device in three steps of a connecting process,

2 a longitudinal sectional view of a second embodiment of the connecting device,

3a a plan view of an inserted into a sheet insert as part of a third embodiment of the connecting device and

3b a sectional view of the inserted into the sheet insert according to 3a ,

In the 1 and 2 is in each case an embodiment of a connecting device 1 for thin-walled bodies or sheets 2 . 3 shown. The connection device 1 includes two openings, a first opening 4 in a first sheet 2 and a second opening 5 in a second sheet 3 , which are arranged in the connecting position at least in alignment and axially spaced from each other. The second sheet 3 has one from the first opening 4 arching lowering 6 with a hollow cone dull 7 formed form, these two parallel bases, a large footprint 8th and a small footprint 9 , Includes and in connection position in the insertion direction v to the small footprint 9 rejuvenated. The second opening 5 forms the small base 9 , A screw 10 with an external thread 11 having screw shank 12 and a screw head 13 is with the screw shaft 12 in the insertion direction v through both openings 4 . 5 guided, with the screw with its screwing into the second opening 5 by means of its external thread 11 under non-cutting forming an internal thread 14 in the wall of the second opening 5 brings. In the in 1c and 2 shown connection position is the screw 10 with her screw head 13 on the outside facing the insertion direction 15 of the first sheet 2 at. The second opening 5 is conically widened in insertion direction v.

The external thread 11 the screw 10 is hardened here. The sheets 2 . 3 are made of ZSTE220, a micro-alloyed steel.

In 1a to 1c is the connection process in particular under the aspect of introducing the internal thread 14 in the wall of the second opening 5 by means of the external thread 11 the screw 10 shown in the second opening 5 is screwed in. Clearly the 1a and 1b It can be seen that the free end 16 of the screw shaft 12 in the insertion v here non-linear tapers. Similarly, the core diameter d _{1 of} the screw shaft decreases 12 , where in 1 the core diameter d _{1 is shown} with its maximum extent. In 1a is the screw 10 already with the screw shaft 12 so far through the two openings 4 . 5 led that her external thread 11 with a front in the insertion v section 17 begins, for non-cutting introduction of the internal thread 14 in the wall of the second opening 5 intervene, whereby the rejuvenation of the free end 16 in a rear section in the insertion direction v 18 previously as an insertion aid in the second opening 5 has acted. In the embodiment of the connecting device shown here 1 extends the external thread for easy insertion over the entire free end 16 ,

The front section 17 here has three successive in the insertion direction sections 19 - 21 in which, while displacing the second opening 5 limiting material, the internal thread is rolled or caught in the wall. In a third section 19 in which the external thread 11 is designed as a pointed thread, is a first thread 22 buried, which also serves as a guide. Because the second opening 5 opens conically, is from the external thread 15 in the third section, only an edge region at the opening edge is gripped by the external thread, which can already be torn away under lower deformation forces ( 1a ).

In 1b is the burial of the internal thread 14 already advanced by the threads 22 in a second section 20 of external thread 11 dull and widened. The external thread 11 is designed trapezoidal. Since at the same time the core diameter d _{1 of} the screw shaft 12 increases, also the diameter d _{2 of} the second opening 5 extended. Thus, burial builds pressures on the inner wall of the second opening 5 on, through which the material begins to flow and under pushing away or pushing away tight attachment to the external thread 11 rests and ridges 23 on both sides of the second opening 5 training. As in 1b clearly recognizable, the internal thread sits down 14 in the beads 23 continues and enlarges. With the beads 23 Thus, at the same time the sheet thickness of the second sheet 3 in the area of the second opening 5 increased. The second opening 5 relies elephant foot-like on the external thread 11 from. Thus, under displacement and flow of the second opening 5 limiting material a very tight, seamless meshing of internal thread 14 and external thread 11 and an axial extension of the internal thread 14 in the beads 23 achieved.

In 1c are screw 10 and sheets 2 . 3 is the connection position 1 in which the screw head 13 with a disc-shaped edge 24 on the outside 15 of the first sheet 2 is applied. The non-cutting shaping of the internal thread 14 is closed. The internal thread 14 claws with tightening the screw 10 further into the external thread 11 , in which, thanks to the hollow frustoconical form of lowering 6 , especially on the first opening 4 facing flank 24 supported by the external thread. For this purpose, the pitch angle β of the external thread 11 is greater than the angle α, the coat 25 the lowering 6 and the big footprint 8th or the first sheet 2 lock in. In 1c are reproduced qualitatively power relations, after a bolt force K _s by tightening the screw 10 on the internal thread 14 and according to the angle α on the mantle 25 acts, so that the screw force K _s by means of the shell 25 is derived as Kraft K _m pointed vault-like, which stabilizes the compound. It should be noted that here is the coat 25 is shown as a section, the distribution of forces but spatially according to the Hohlkegelstumpfform.

The regarding the plant to the outside 15 effective diameter d _{3 of} the edge 24 larger than the diameter d _{4 of} the large base area 8th the lowering 6 ie the diameter d _{3 of} the rim 24 is larger than the diameter d _{4 of} the large base area 8th the lowering 6 and this in turn larger than the diameter d _{5 of} the first opening 4 , Thus occurs from the edge of the large footprint 8th over the wall of the first sheet 2 at this point an immediate force transfer to the screw head 13 towards, without additional force moments are generated, for example, can cause the opening edge of the first opening 4 in the lowering 6 is involved.

Because the screw 10 with the external thread 11 under non-cutting shaping of the internal thread 14 and training of the beads 23 almost fixed in the second opening, the screw can be solved under circumstances only with at least partial destruction of the internal thread by means of a tool, such as screwdrivers. Therefore, in this embodiment, the diameter d _{5 of} the first opening 4 chosen so large that for renewal of the connection another larger, designed for rolling or Einfurchen an internal thread screw can be screwed, which then forms a new internal thread in the second opening without cutting. Therefore, a corresponding repair set can be provided, which is not shown in the drawing.

In 2 is a second embodiment of the connecting device 1 shown differing from the in 1 shown in particular differs in that the two sheets 2 . 3 are spaced apart from each other in the connection position shown here. Here are the second sheet 3 introduced four tabs 26 provided at equal distances from each other circumferentially around the lowering 6 are arranged, wherein the first sheet 2 upper side on the projections 26 supported.

3 gives a further embodiment of the connecting device 1 again, with only a second sheet 3 with a recess 27 is reproduced, at the overlapping an insert 28 by spot welding 29 is fixed in position. The insert 28 indicates the lowering 6 with the second opening 5 on. The illustration of the first sheet has been omitted here for the sake of clarity.

1

connecting device

2

first sheet

3

second sheet

4

first opening

5

second opening

6

lowering

7

Hollow frustum

8th

size Floor space

9

small Floor space

10

screw

11

external thread

12

screw shaft

13

screw head

14

inner thread

15

outside

16

free The End

17

front section

18

rear section

19

first section

20

second section

21

third section

22

thread

23

bead

24

edge

25

coat

26

head Start

27

recess

28

insert

29

spot welding

α

angle

β

lead angle

d ₁

core diameter

d ₂

diameter second opening

d ₃

diameter edge

d ₄

diameter large footprint

d ₅

diameter first opening

K _s

bolt force

K _m

force

v

insertion

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 4659246 B [0003]
• - EP 1398514 A1 [0004]

Claims (15)

Connecting device for thin-walled bodies or sheets, in particular for a connection of a first sheet ( 2 ) with a second sheet ( 3 ), with a screw ( 10 ), which has a screw head ( 13 ) and a screw shaft ( 12 ) with external thread ( 11 ) and a second plate ( 2 ), which is a subsidence ( 6 ), in which a second opening ( 5 ) is arranged, wherein the screw ( 10 ) with the external thread ( 11 ) forcefully into the second opening ( 5 ) of the second sheet ( 3 ) engages and the screw head ( 13 ) against the direction of lowering ( 6 ), characterized in that the second opening ( 5 ) an internal thread ( 14 ), which by means of the external thread ( 11 ) of the screw ( 10 ) when screwing it into the second opening ( 5 ) in a non-cutting forming under displacement of the second opening ( 5 ) limiting material in the second opening ( 5 ) is introduced. Connecting device according to claim 1, characterized in that the lowering ( 6 ) as a hollow truncated cone ( 7 ) is formed. Connecting device according to claim 2, characterized in that the pitch angle ( 13 ) of the external thread ( 11 ) is greater than or equal to the angle (α) that the shell ( 25 ) of the hollow frustoconical depression ( 6 ) with their larger footprint ( 8th ). Connecting device according to one of the preceding claims, characterized in that the diameter (d ₄ ) of the large base ( 8th ) of lowering ( 6 ) greater than the diameter (d ₅ ) of the first opening ( 4 ) and smaller than a diameter (d ₃ ) of a contact area, in which the screw ( 10 ) indirectly or directly on the outer side facing the insertion direction (v) ( 15 ) of the first sheet ( 2 ) is supported. Connecting device according to one of the preceding claims, characterized in that under the action of the non-cutting introduction or digging of the internal thread ( 14 ) at the second opening ( 5 ) limiting wall in and / or against insertion (v) in each case an at least partially circumferential bead ( 23 ) is formed, in which the internal thread ( 14 ) extends at least partially into or against the insertion direction (v). Connecting device according to one of the preceding claims, characterized in that the second opening ( 5 ) is conically widened in the insertion direction (v). Connecting device according to one of the preceding claims, characterized in that the screw shaft ( 12 ) a conically tapering free end ( 16 with a section following in the insertion direction (v), a rear section in the insertion direction (v) ( 18 ) for introducing the free end ( 16 ) into the second opening ( 5 ) and in the insertion (v) front section ( 17 ) with the external thread ( 11 ) having. Connecting device according to claim one of the preceding claims, characterized in that the external thread ( 11 ) two in the insertion direction (v) successive sections, one in the insertion direction (v) front first section ( 19 ) for the finished burying of the internal thread ( 14 ) into the second opening ( 5 ) with a pointed thread and in the insertion (v) adjoining second section ( 20 ) for pre-burying the internal thread ( 14 ) in the wall of the second opening ( 5 ) having a trapezoidal thread or a round thread. Connecting device according to claim 8, characterized in that the external thread ( 11 ) in the insertion (v) rear third section ( 21 ) with a pointed thread for its first engagement in the wall of the second opening ( 5 ) having. Connecting device according to one of the preceding claims, characterized in that the two sheets ( 2 . 3 ) are arranged spaced apart in the connection position. Connecting device according to one of the preceding claims, characterized in that the second plate ( 3 ) at its in the connecting position the first sheet ( 2 ) facing side surface near or at the opening edge of the second opening ( 5 ) at least one projection extending counter to the direction of insertion (v) ( 26 ), which extends at least partially around the second opening ( 5 ). Connecting device according to claim 11, characterized in that a plurality of projections ( 26 ) are provided on a circumferential circle and on the same one behind the other around the second opening ( 5 ) are arranged. Connecting device according to one of the preceding claims, characterized in that an insert piece ( 28 ) with the second opening ( 5 ) provided in or on one of the intended pieces ( 28 ) adapted recess ( 27 ) of the second sheet ( 3 ) is determinable. Repair kit for repairing a connecting device ( 1 ) according to one of claims 1 to 13, wherein the connecting device ( 1 ) in a second sheet ( 3 ) a second opening ( 5 ) with egg internal thread ( 14 ), which is defective in the event of repair, characterized in that it has a component with a to the second opening ( 5 ) adapted opening with the internal thread ( 14 ) and in an installed position in the connecting device ( 1 ) in the insertion direction (v) has front side surface which in the insertion direction (v) rear side surface of the second sheet ( 3 ) in the vicinity of the second opening ( 5 ) and to the same for connection to the screw of the connecting device ( 1 ) can be applied, and / or a screw with self-indenting, self-curling or selbsteinfurchenden external thread whose outer diameter by a standard size larger than that in the connecting device ( 1 ) is previously related. Repair kit according to claim 14, characterized that the component as a flanged nut with a disc-shaped Edge is formed, wherein the edge of the front side surface having.