Fastener, arrangement and method

Abstract

The invention relates to a connecting element for insertion into a through-opening of a component, wherein the through-opening has at least one widening section, wherein the connecting element has an annular expansion collar projecting from an underside of the connecting element, wherein the expansion collar is designed such that it can be expanded in the radial direction by means of plastic deformation.

Description

The invention relates to a connecting element for insertion into a through-opening of a component. The invention also relates to an arrangement with a connecting element. The invention further relates to a method for producing a through-opening in a component and to a method for inserting a connecting element into a through-opening of a component.The invention is intended to improve a connecting element, an arrangement with a connecting element, a method for producing a through-opening in a component and a method for inserting a connecting element into a through-opening of a component.According to the invention, a connecting element having the features of claim 1, an arrangement having the features of claim 5, a method for producing a through-opening in a component having the features of claim 14 and a method for inserting a connecting element into a through-opening of a component having the features of claim 19 are provided for this purpose. Advantageous refinements of the invention are specified in the respective dependent claims.A connecting element for insertion into a through-opening of a component, wherein the through-opening has at least one widening section, has an annular expansion collar projecting from an underside of the connecting element, wherein the expansion collar is designed such that it can be expanded in the radial direction by means of plastic deformation. By simply spreading the spreading collar, the connecting element can thereby be securely anchored in the through-opening. For example, electrical connection points, welding points, generally connecting elements, can thereby be anchored to a component. A very important advantage of the connecting element according to the invention is that the preparation of the through-opening in the component can be carried out easily and quickly. For secure anchoring of the connecting element to the annular expansion collar, a through-opening with at least one expanding section is sufficient. The widening section advantageously extends as far as the end of the through-opening, so that the end of the widening section with a large diameter therefore also forms the end of the through-opening. In particular, no beads, depressions or other impressions surrounding a through-opening are required in the component, as are required, for example, when setting rivets or the like, if the underside of the connecting element is intended to be flush with the underside of the component. The deforming of the expansion collar takes place to only a small extent, so that the deforming forces can be kept low and the material load of the connecting element in the region of the deformed expansion collar can also be kept low. The component itself has the through-opening widening at least in sections and does not have to be formed. As a result, the connecting element according to the invention can also be used in components which consist of a material of comparable strength to the connecting element itself. As a rule, one joining partner must be harder than the other, not as according to the invention. If, for example, rivets are inserted into a component, the component must always be formed from harder material in order to enable a clean shaping of the rivet without deforming the component itself too much. The connecting element according to the invention is inserted into an expanding section of the through-opening by means of plastic deformation of the expansion collar. The component itself is not deformed in this case. The component and the connecting element can consequently consist of the same material, consist of different materials, wherein the material of the component can be harder or softer than the material of the connecting element. The connecting element according to the invention can thus be used in an extremely flexible manner.In a further development of the invention, as seen in cross section, an outer contour of the expansion collar is circular, elliptical, polygonal, in particular hexagonal, or polygonal with rounded corners.In a further development of the invention, as seen in cross section, an inner contour of the expansion collar is circular, elliptical, polygonal, in particular hexagonal, or polygonal with rounded corners.In a further development of the invention, the connecting element consists, at least in the region of the expansion collar, of a plastically deformable metallic material, in particular aluminum.A wall thickness of the annular spreading collar can be constant, but according to the invention this is not necessarily the case. In this way, the connecting element can be produced in a simple manner, for example by cold forming. In particular, the annular spreading collar has a rectangular cross section in a sectional plane containing the central longitudinal axis of the spreading collar. Viewed in a direction parallel to a central longitudinal axis of the expansion collar, the latter can be of circular ring-shaped design.If, in addition, security against twisting of the connecting element in the through-opening is required, the circumference of the expansion collar can, however, also deviate from a circular shape, for example elliptical, rectangular, in the form of a regular polygon or similar.An arrangement according to the invention with a connecting element and at least one component connected to the connecting element is characterized in that the connecting element has an annular expansion collar projecting from an underside of the connecting element and in that the component has a through-opening, wherein the through-opening has at least one widening section, wherein the expansion collar of the connecting element extends into the through-opening and abuts at least in sections against an inner wall of the widening section of the through-opening.By simply spreading the spreading collar open and by plastically deforming the spreading collar during the expansion until it abuts in sections against an inner wall of the widening section of the through-opening, the connecting element can thereby be securely anchored to the component. The component does not have to be prepared in a complicated manner for this purpose; only a through-opening with an expanding section is required. In particular, no beads, depressions or depressions are required on the component in order to be able to anchor the connecting element securely.In a development of the invention, the through-opening has a first, cylindrical section, wherein the widening section adjoins the first section.The widening section forms an undercut, to which the spreading collar can be anchored. By providing the first, cylindrical section, components with a large thickness, for example metal sheets with a large metal sheet thickness, can also be provided in a simple manner with a through-opening which allows the secure anchoring of the connecting element by means of the expansion collar.In a further development of the invention, the widening section is of frustoconical or frustopyramidal configuration.In a further development of the invention, as seen in cross section, the widening section is circular, elliptical, polygonal, in particular hexagonal, or polygonal with rounded corners.In a further development of the invention, an angle (X) which a wall of the widening section assumes with respect to the central longitudinal axis of the through-opening is greater than or equal to eight degrees and less than or equal to 45 degrees.The angle of the wall of the widening section is selected to be as large as possible in order to form a large undercut. A limit for the size of the angle of the wall lies in the deformability of the expansion collar, angles between approximately ten degrees and 45 degrees have proven to be extremely advantageous.In a further development of the invention, the spreading collar abuts the inner wall of the passage opening over the entire length of the passage opening.In this way, a secure anchoring of the connecting element in the through-opening of the component is achieved. As has been stated, after the insertion of the connecting element into the through-opening, the expansion collar is expanded in the radial direction by means of plastic deformation until the expansion collar bears against the inner wall of the through-opening over the entire length of the through-opening.In a development of the invention, a free end of the expansion collar is arranged within the through-opening or arranged flush with an underside of a section of the component surrounding the through-opening.In this way, it can be achieved that the connecting element and in particular the expansion collar do not protrude beyond the underside of the component. This is achieved without the component having to be provided with impressions or the like. Nevertheless, the connecting element can be securely anchored in the through-opening of the component by means of the expansion collar.In a development of the invention, the through-opening has a large surface roughness at least in the region of the widening section.In this way, a pull-out force of the connecting element can be substantially increased and the connecting element is also reliably secured against rotation. In the assembled state of the connecting element, the expansion collar bears against the inner wall of the through-opening at least in the region of the expanding section. A large surface roughness, which entails small depressions and small elevations in the inner wall, then leads during the plastic deformation of the expansion collar to the material of the expansion collar engaging into the depressions of the inner wall of the through-opening. The anchoring of the connecting element in the through-opening can thereby also resist very large pull-out forces and torques.In a development of the invention, the through-opening has a first cylindrical section, wherein the widening section adjoins the first section, wherein one of the surface roughness in the region of the widening section is greater, in particular is more than twice as great as the surface roughness in the first cylindrical section.Decisive for the achievable pull-out force of the connecting element is the anchoring of the expansion collar on the expanding section of the through-opening. A large surface roughness in the widening portion consequently ensures reliable anchoring of the connecting element.In a method according to the invention for producing a through-opening in a component, wherein the through-opening is provided for inserting a connecting element according to the invention and the through-opening has at least one widening section, the formation of the through-opening during the production of the component is provided by means of punching, by means of forming, in particular by means of 3D printing, casting or injection molding, by forming the through-opening by means of chip-removing methods, in particular drilling and / or milling, or by forming the through-opening by means of chip-less methods.In a development of the invention, provision is made for the production of a first, cylindrical section and an expanding section adjoining the first section during the formation of the through-opening, wherein the cylindrical section starts from the beginning of the through-opening and the expanding section extends as far as the end of the through-opening.When producing the through-opening, an angle which a wall of the widening section assumes with respect to the central longitudinal axis of the through-opening is set to a value between 8° and 45°.In a development of the invention, the passage opening is formed by means of punching using a punch and a die, wherein the component is accommodated in sections between the punch and the die and wherein a cutting gap between the die and the punch is 7.5% to 20%, in particular 10% to 15%, of the component thickness of the component in the region of the passage opening.A cutting gap between die and punch between 7.5% and 20% of the component thickness is enlarged compared to a cutting gap customary in punching. This achieves a punching with a first, cylindrical section of the through-opening and an expanding, in particular frustoconical, section in a second section of the through-opening, wherein the expanding second section is produced by a forced fracture of the material of the component during the punching. The enlargement of the cutting gap compared to cutting gap sizes customary during punching consequently leads to the surprising result that a formation of the through-opening which is undesirable during punching of through-openings is obtained, but which is ideal for the insertion of a connecting element with expansion collars. When punching through-openings, it is always desirable to achieve a through-opening which is cylindrical over its entire length. By suitable selection of the cutting gap, in particular of a narrow cutting gap, the formation of a forced fracture during punching is minimized and at least largely avoided. The inventors have surprisingly found that a poor punching according to the technical rules results in the formation of a through hole comprising a first cylindrical portion and a second widening portion ideally suitable for anchoring a connection element with expansion collars. As has been stated, the widening section is automatically produced during the punching of the through-opening by a forced fracture of the material of the component in the second section. The cutting gap is defined as half the difference in diameters between the punch and die.In a development of the invention, the formation of a rough surface structure on the inner wall of the through-opening is provided at least in the region of the frustoconically widening section, in particular by means of generating a forced fracture in the region of the frustoconically widening section during the punching of the through-opening.The intentional acceptance of a forced fracture of the material of the component during the punching of the through-opening produces not only an expanding section of the through-opening, but also a rough surface structure on the inner wall of the through-opening in the region of the expanding section. Here too, the intentional purchase of a forced fracture of the material of the component during punching, which usually is to be completely or largely avoided during punching of through-openings, leads to a formation of the through-opening which is ideally suitable for anchoring a connecting element according to the invention with expansion collars.In a method according to the invention for inserting a connecting element into a through-opening of a component, wherein the connecting element has an annular expansion collar projecting from an underside of the connecting element, wherein the expansion collar is designed such that it can be expanded in the radial direction by means of plastic deformation and wherein the through-opening has at least one expanding section, the following steps are provided: inserting the expansion collar of the connecting element into the through-opening in the component, such that the expansion collar is arranged at least in sections radially within the expanding section of the through-opening, and expanding the expansion collar until an outer side of the expansion collar bears circumferentially against a wall of the expanding section of the through-opening.In the method according to the invention, the expansion collar is used in such a way that the free end of the expansion collar lies on the side of the widening section with the largest diameter of the through-opening. When the expansion collar is expanded in the radial direction, an undercut of the expansion collar is thereby formed when it bears against the inner wall of the through-opening. As a result, the connecting element can be securely anchored in the through-opening of the component.In a development of the invention, the production of the through-opening in the component by means of punching using a punch and a die is provided, wherein a cutting gap between the punch and die is between 7.5% and 20%, in particular between 10% and 15%, of the thickness of the component in the region of the through-opening to be produced.The selection of a cutting gap between the punch and die which is dimensioned in this manner leads, as has already been explained above, to the formation of a forced fracture of the material of the component during punching in a second section of the punched through-opening, which section is passed through the component in the direction of movement of the punch. Such a force fracture causes not only a frustoconically widening section of the through-opening, wherein the frustoconical section widens in the punching direction, but also the formation of a rough surface in the region of the force fracture, that is to say in the region of the frustoconically widening section. By selecting a cutting gap which is larger than is usually set when punching through openings, the through opening is thereby given an ideal shape for the secure anchoring of the connection element according to the invention with a plastically deformable expansion collar.In a further development of the invention, the stamping of an annular depression by means of the die into an underside of the component facing the die and into an underside of the expansion collar facing the die is provided, wherein the depression is stamped along a contact line between connecting element and component on the underside of component and expansion collar.By means of the die, the expansion collar is expanded in the radial direction until it bears against the inner wall of at least the frustoconically widening section of the through-opening. By means of the die, by further advancing the die in the direction of the component, after the radially spreading open of the spreading collar by means of an annular projection on the die, the annular depression is still impressed. This leads to additional toothing of the component and the expansion collar and thus leads to a sealed configuration of the connection between the connecting element and the component. Such a sealed embodiment of the connection can be important, for example, in battery applications in which it must be ensured that the connection between the connecting element and the component is gas-tight.In a development of the invention, the materially integral connection of the connecting element and the component is provided in the region of the annular depression.For example, the expansion collar and component are soldered or welded in the region of the annular depression in order to provide a sealed connection. For example, the annular depression can also be filled with adhesive or sealing compound in order to provide a sealed connection between connecting element and component in the same way.Further features and advantages of the invention are evident from the claims and the following description of preferred embodiments of the invention in conjunction with the drawings. Individual features of the different, illustrated and described embodiments can be combined with one another in any desired manner without exceeding the scope of the invention. This also applies to the combination of individual features without further individual features with which they are illustrated and / or described in connection.In the drawings, there are shown: FIG. 1 shows a partially cut side view of a connecting element according to the invention, FIG. 2 shows a sectional view of a component with a through-opening for inserting the connecting element of FIG. 1, FIG. 3 is an enlarged partial view of the detail III of FIG. 2, FIG. 4 shows a further sectional view of the component of FIG. 2, an angle X being drawn in, FIG. 5 shows a schematic illustration of the component of FIG. 2 during the punching of the through-opening, FIG. 6 shows a partial sectional view of an arrangement with a connecting element according to the invention and a component, FIG. 7 shows a partially cut-away view of a component and of a connecting element according to the invention during the insertion of the connecting element into the through-opening of the component in a first state, FIG. 8 shows a partially cut-away view of a connecting element according to the invention and of a component during the insertion of the connecting element into the through-opening of the component in a second state, FIG. 9 shows a detail of an arrangement similar to FIGS. 7 and 8 during the insertion of the connecting element into the through-opening according to a further embodiment, FIG. 10 shows a sectional view of a component, produced by primary forming or machining, with a through opening according to a first embodiment, FIG. 11 shows a sectional view of a component, produced by punching, with a through opening according to a second embodiment, FIG. 12 shows a sectional view of a component, produced by primary forming or machining, with a through opening according to a third embodiment, FIG. 13 shows a sectional view of a component, produced by punching, with a through opening according to a fourth embodiment, FIG. 14 shows a sectional view of a component, produced by primary forming or machining, with a through opening according to a fifth embodiment, and FIG. 15 shows a sectional view of a component, produced by punching, with a through opening according to a sixth embodiment.FIG. 1 shows a connecting element 10 according to the invention. The connecting element 10 has a cylindrical upper part 12, a likewise cylindrical main part 14 and an annular spreading collar 16 extending from a lower side of the main part 14.FIG. 1 shows a side view of the connecting element 10 in the left half. It can be clearly seen in the side view that an outer diameter of the expansion collar 16 corresponds to the outer diameter of the upper part 12. Within the scope of the invention, there is no dependence between the outer diameter of the expansion collar 16 and the outer diameter of the upper part 12.In the right-hand half of the illustration of FIG. 1, the connecting element 10 is illustrated in section. It can be seen that the upper part 12 is provided on the upper side with a frustoconical depression 18. The upper part 12 has a circular cylindrical outer wall. A shoulder is disposed between the upper part 12 and the main part 14, since the main part 14 has a larger outer diameter than the upper part 12.A shoulder is likewise arranged between the main part 14 and an outer wall of the expansion collar 16, since the outer diameter of the expansion collar 16 is smaller than the outer diameter of the main part 14. A shoulder between the main part 14 and the expansion collar 16 is advantageous within the scope of the invention, since the connecting element 10 can then be placed with the underside of the main part 14 on an upper side of the component, see FIG. 6, and the position of the connecting element 10 relative to the component is thereby positioned in the insertion direction of the connecting element 10.The expansion collar 16 has a rectangular cross section in the sectional view of FIG. 1. The wall thickness of the spreading collar 16 is consequently constant over its entire length. An outer wall of the expansion collar 16 is longer than an inner wall of the expansion collar, wherein it is possible to deviate therefrom within the scope of the invention. When radially spreading the spreading collar 16, the outer wall of the spreading collar is therefore not spread open or is spread open only very little in the radial direction in the upper section in FIG. 1. A deformation of the expansion collar during expansion therefore takes place mainly in the region of the rectangular cross section of the expansion collar 16.FIG. 2 shows a component 20 with a through-opening 22, which is provided for inserting the connecting element 10 of FIG. 1.It can be seen in FIG. 2 that the through-opening 22 has an inlet section which extends in a rounded manner and then has a first section 24 which is of cylindrical design, see FIG. 3.The enlarged representation of the detail III in FIG. 3, wherein FIG. 3 only represents a partial representation of the detail III, reveals that the through-opening 22 has a total of three sections. Starting from an upper side of the component 20, wherein the component 20 is realized in the form of a sheet metal, the through-opening starts with the rounded inlet section 28. The cylindrical first section 24 adjoins the inlet section 28, which then merges into the second section 26 widening in the shape of a truncated cone. The frustoconical second section 26 extends as far as the lower end of the through-opening 22, as shown in FIG. 3, wherein the largest diameter of the frustoconical section 26 and of the through-opening 22 is also arranged at the lower end of the through-opening 22.The frustoconically widening portion 26 widens in a direction from the upper side of the component 20 in FIG. 3 toward the lower side of the component 20. When the connecting element 10 of FIG. 1 is inserted into the through-opening 22, an undercut can thereby form between the component 20 and the spreading collar 16 or connecting element 10 when the spreading collar 16 is radially spread open, in order to anchor the connecting element 10 securely in the through-opening 22.An inner wall of the tapered widening portion 26 is shown dotted in FIG. 3. This is intended to symbolise that the inner wall of the section 26 has a greater surface roughness than the cylindrical section 24.FIG. 4 shows a further sectional view of the component 20 of FIG. 2 with the through opening 22, and an angle of the frustoconically widening section 26 is indicated by X in FIG. 4. The angle X results during the punching of the through-opening 22 on the basis of the size of a cutting gap and the material properties of the component 20.FIG. 5 shows an arrangement for producing the through-opening 24 in the component 20 by means of punching. The component 20 is shown in FIG. 5 without the through-opening 22. A punch 30 for punching the through-opening 22 rests on an upper side of the component 20 in the state of FIG. 5. An underside of the component 20 rests on a die 32, wherein the die 32 has an opening 34, into which a punched-out slug from the component 20 can enter when the through-opening 22 is stamped and into which the punch 30 can move in sections during the stamping.The punch 30 has an outer diameter smaller than an inner diameter of the opening 34 in the die 32. This cutting gap is denoted by the reference symbol S in FIG. 5. The cutting gap is circumferential when the punch and die are correctly positioned.The through-opening 22 in the component 20, as is illustrated in FIGS. 2, 3 and 4, is formed by means of punching, as explained using the punch 30 schematically illustrated in FIG. 5 and the die 32 which is likewise schematically illustrated. The cutting gap S is selected here to be larger within the scope of the invention than is customary when punching out through-openings. When punching through-openings, it is usually attempted that the resulting through-opening is cylindrical over the major part of its length. At the beginning of the through-opening and at the end of the through-opening, deviations from the cylindrical form of the through-opening can result. Usually, when punching through-openings, the cutting gap S is selected to be as small as possible in order to still achieve a clean punching effect and thus a shape of the through-opening that is as cylindrical as possible, in particular in the last section of the punching process, i.e. before the punched-out slug is completely released from the component 20.Within the scope of the invention, this usual procedure is deviated by selecting a cutting gap between the opening 34 of the die 32 and the punch 30 to be larger than usual, so that the cutting gap amounts to 7.5% to 20%, in particular 10% to 15%, of the component thickness of the component 20. The cutting gap is thereby enlarged compared to a cutting gap customary during punching. This leads to a forced fracture of the material of the component 20 during the punching process. Specifically, when the punch 30 is pressed into the component 20, the first portion 28 of the through-opening 22 is first formed, see FIG. 3 ; in this case, the surface of the component 20, which is arranged under the punch 30, is pressed into the component 20 to a certain extent, resulting in the rounded formation of the inner wall of the entry portion 28. If the punch 30 is then pressed in further in the course of the punching process, the material of the component 20 is sheared off by the outer edges of the punch 30, so that the cylindrical first section 24 is formed. The cutting gap S, which is enlarged according to the invention, causes a forced fracture of the material of the component 20 in the course of the punching process. This is because the cutting gap S is too large to achieve a cutting or punching action up to the bottom of the component 20. As a result, the slug is pressed out by the punch 30 and the portions of the material of the component 20 which still connect the slug to the component 20 break off during the further advancement of the punch 30. This is referred to as force rupture during punching. Such a forced fracture during punching results in the conically widening second section 26 of the through-opening, see FIG. 3, which not only has a rougher surface structure compared to the cylindrical section 24, as symbolized in FIG. 3, but widens in the feed direction of the punch 30, that is to say from the upper side of the component 20 toward the lower side of the component 20, in the shape of a truncated cone with the angle X, see FIG. 4.It has been found within the scope of the invention that such a forced fracture, which is actually undesirable during the punching of through-openings, leads to a formation of the punched through-opening 22, which is ideal for anchoring the connecting element 10 according to the invention by radially spreading the spreading collar 16. The targeted enlargement of the cutting gap compared to rules accepted by the skilled person during punching leads to a reinforced formation of a forced fracture and a longer frustoconically widening section 26. This leads to a different configuration of the through-opening 22 during punching, in particular to different aspect ratios of the cylindrical section 24 and of the frustoconically widening section 26.Within the scope of the invention, the through-opening 22 can also be produced in a manner other than by punching, for example by primary forming, in particular by means of 3D printing, casting or injection molding, or by means of machining methods, in particular drilling, lowering and / or milling. By such methods, the angle X and the length of the frusto-conical widening portion 26 can then be adjusted to the requirements of the particular application. Through-openings which are produced by means of forming or machining processes are illustrated in FIGS. 10, 12 and 14. By means of forming or machining methods, the through-opening 22, for example in a metal sheet, can also be formed exclusively conically or in the shape of a truncated cone without a cylindrical section.FIG. 6 shows a sectional sectional view of an arrangement with the connecting element 10 according to the invention of FIG. 1 and the component 20 according to the invention, wherein the connecting element 10 has already been inserted into the through-opening 22 of the component 20 and has been anchored in this through-opening 22.It can be seen from FIG. 6 that the connecting element 10 has been placed with the underside of the main part 14 on the upper side of the component 20 and that the expansion collar 16 has subsequently been expanded in the radial direction, so that an outer wall of the expansion collar 16 bears against the inner wall of the through-opening 22. It can be seen in FIG. 6 that the outer wall of the expansion collar 16 bears against the inner wall of the passage opening 22 substantially over the entire length of the passage opening 22. Only in the lowest part of the through-opening 22 in FIG. 6 is a gap, triangular in cross section, visible between the inner wall of the through-opening 22 and the outer wall of the expansion collar 16. This gap can optionally be used to arrange a sealing means, for example adhesive or sealing compound, in order to achieve a sealed connection between connecting element 10 and component 20. This is useful, for example, when the component 20 forms a cover plate for a battery and the connection between the connecting element 10 and the component 20 is to be embodied in a watertight and gas-tight manner. The triangular gap between the outer wall of the expansion collar 16 and the inner wall of the through-opening 22 in the component 20, however, can also be filled with solder, for example, or can be used to weld the expansion collar 16 and the component 20 to one another in this region in order to obtain a sealed connection.FIG. 7 shows a partially cut-away view of an arrangement after the insertion of the connecting element 10 into the through-opening of the component 20, but before the radial spreading open of the spreading collar 16 of the connecting element 10.The spreading of the spreading collar 16 in the radial direction is effected by means of a die 40 which is illustrated in FIG. 7 below the underside of the component 20 and which has a frustoconical elevation 42 on its upper side which is matched to the dimensions of the spreading collar 16. A holding-down device above the connecting element 10 is not shown for the sake of clarity.The enlarged detail in FIG. 7 shows that after the insertion of the connecting element 10, the expansion collar 16 is still cylindrical and is arranged with its lower end in FIG. 7 flush with an underside of the component 20. The flush arrangement is not obligatory within the scope of the invention; ideally, the lower end of the expansion collar will protrude slightly with respect to the underside of the component 20. The frustoconical elevation 42 on the upper side of the die 40 extends a certain distance into the expansion collar 16 before the start of the deformation. Upon a further advance of the die 40 in the direction of the underside of the component 20, the frustoconical elevation 42 will penetrate into the central recess which is surrounded by the expansion collar 16 and, in the process, press the expansion collar 16 radially outwards by means of its frustoconical outer wall. The expansion collar 16, in particular the entire connecting element 10, is made of a plastically deformable material, in particular a plastically deformable metal, for example aluminum, so that the radial expansion of the expansion collar 16 results in a plastic deformation of the expansion collar 16, so that the connecting element 10 is then permanently anchored in the through-opening 22 of the component 20.FIG. 8 shows the state of the arrangement of FIG. 7, in which the die 40 has been moved so far against the underside of the component 20 that an upper side of the die 40 surrounding the frustoconical elevation 42 of the die bears against an underside of the component 20. FIG. 8 thus shows the state in which the die 40 has arrived at the end of the delivery path in the direction of the component 20. As can be seen from FIG. 8, the frustoconical projection 42 has in this state spread the spreading collar 16 radially outwards and at the same time plastically deformed. A plastic deformation of the expansion collar can also be seen from the fact that in FIG. 8 the expansion collar 16 is now thinner at the lower end than at its upper end. An outer wall of the expansion collar 16 now rests on the inner wall of the passage opening 22 substantially over the entire length of the passage opening 22. Only in the rounded entry section of the through-opening 22 starting from the top side of the component 20 is a small intermediate space between the connecting element 10 and the component 20. By appropriate configuration of the through-opening 22, of the connecting element 10 and / or of the die 40 and, if appropriate, of a counterholder not illustrated in FIGS. 7 and 8, this intermediate space can be completely avoided.At the end of the through-opening 22, i.e. shortly before the transition of the inner wall of the through-opening 22 into the underside of the component 20, the inner wall of the through-opening 22 is exposed. In the embodiment shown in FIG. 8, the expansion collar 16 has intentionally been selected to be somewhat shorter than the thickness of the component 20 or the length of the inner wall of the through-opening 22, which ensures that the underside of the expansion collar 16 is still located within the through-opening 22 or is at most flush with the underside of the component 20.FIG. 9 shows the state of the arrangement of FIG. 8 in enlarged detail when using a die 140 according to a further development of the invention. In contrast to the die 40 of FIGS. 7 and 8, the die 140 has an annular projection 144 which surrounds the frustoconical elevation 42 on the upper side of the die 140. The annular protrusion 144 is formed to present an annular groove in the underside of the assembly of the component 20 and the connector 10. The annular depression then lies partially in the material of the component 20 and partially in the material of the connecting element 10 or of the expansion collar 16. This annular depression leads to an additional plastic deformation of the component 20 and of the expansion collar 16 in the region of the contact surface between connecting element 10 and component 20. The annular depression can also be filled with a sealant or an adhesive or can be used to braze or weld the connecting element 10 and the component 20 to one another in the region of the annular depression in order to obtain a sealed connection.FIGS. 10 to 15 show different embodiments of a through-opening in the component 20. The through-openings of FIGS. 11, 13 and 15 were produced by means of non-cutting processes, in particular punching.FIG. 10 shows that the through-opening 22 in the component 20 has a convexly rounded inlet section starting from the upper side of the component 20 and then merges into a cylindrical section 24. The frustoconically widening section 26 adjoins the cylindrical section 24. The frustoconical portion 26 is longer than the entrance portion and the cylindrical portion 24 together. Within the scope of the invention, the cylindrical section 24 and also the rounded inlet section can be omitted when forming the through-opening. The frustoconical widening section 26 is essential for anchoring the connecting element 10. A surface roughness of the through hole 22 is the same over its entire length and in all sections 24, 26.FIG. 12 shows a component 20 with a through-opening 22, which has been formed identically to the through-opening 22 of FIG. 10, i.e. by means of forming during the production of the component or by means of a subsequent machining process. In contrast to the through-opening 22 of FIG. 10, the through-opening 22 of FIG. 12 has a longer cylindrical section 24 and a correspondingly shorter, frustoconically widening section 26. In the embodiment of FIG. 12, the convexly rounded input portion and the cylindrical portion 24 together are about the same length as the frustoconically widening portion 26.FIG. 14 shows a component 20 with a through-opening 22, which has been formed in the same way as the through-openings 22 of FIGS. 10 and 12, for example by means of forming during the production of the component 20 or by means of a subsequent machining process. The through-opening 22 has a convexly rounded inlet section and a cylindrical section 24 and, adjoining the cylindrical section 24, the frustoconically widening section 26. The frustoconical portion 26 is shorter than the cylindrical portion 24 and consequently also shorter than the added length of the convex rounded entrance portion and the cylindrical portion 24.Depending on the intended application, the material of the component 20 and the material of the connecting element 10, the passage opening 22 can be formed in different ways, as was explained with reference to FIGS. 10, 12 and 14.FIGS. 11, 13 and 15 each show the component 20 with differently formed through-openings 22.FIG. 11 shows the component 20 with the through-opening 22, which has already been explained with reference to FIG. 3. The formation of a comparatively large cutting gap between the punch 30 and the opening 34 in the die 32, see FIG. 5, leads to the formation of the through opening 22 with the convexly rounded entry section 28, the cylindrical first section 24 and the frustoconically widening second section 26 having a rough surface structure. It can be seen from Figures 11 and 3 that the cylindrical portion 24 is substantially shorter than the frusto-conical widening portion 26 and is only about one third of the length of the frusto-conical widening portion 26. The frustoconical portion 26 is longer than the entrance portion 28 and the cylindrical portion 24 together. A surface roughness is greater in section 26, in particular twice as great as in sections 24, 28.Figure 13 shows the component 20 having a through-opening 22 in which the frusto-conical widening portion 26 is shorter than in the embodiment of Figure 11. As already explained, the conically widening section 26 with a rough surface structure is produced by producing a forced fracture of the material of the component 20 during the punching of the through-opening 22, The frustoconically widening section 26 which is shorter compared to the embodiment of FIG. 11 is achieved by a reduction of the cutting gap S, see FIG. 5. Compared to the cutting gap S when producing the through-opening 22 of FIGS. 3 and 11, a smaller cutting gap is thus selected when producing the through-opening 22 of FIG. 13. A surface roughness is greater in section 26, in particular twice as great as in sections 24, 28.Within the scope of the invention, the deviating configuration of the through-opening 22 can of course also be achieved by a different material of the component 20. With the same cutting gap, a more brittle material of the component 20 generally results in a greater force fracture, i.e. a longer frustoconical widening section 26.FIG. 15 shows the component 20 having a through hole 22 formed such that the frustoconical widening portion 26 is shorter than the cylindrical portion 24. the frustoconical portion 26 has been formed by a forced fracture of the material of the component 20 when punching the through hole 22. Compared to the through-openings of FIGS. 3, 11 and 13, a smaller cutting gap S was selected for the same material of the component 20 for forming the through-opening 22 of FIG. 15, see FIG. 5.

Claims

Connecting element for insertion into a through-opening of a component, wherein the through-opening has in particular at least one widening section, characterized byan annular expansion collar projecting from an underside of the connecting element, wherein the expansion collar is designed such that it can be expanded in the radial direction by means of plastic deformation.Connecting element according to Claim 1, characterized in that the connecting element consists, at least in the region of the expansion collar, of a plastically deformable metallic material, in particular aluminium.Connecting element according to claim 1 or 2, characterised in that, viewed in cross-section, an outer contour of the expansion collar is circular, elliptical, polygonal, in particular hexagonal, or polygonal with rounded corners.Connecting element according to claim 1, 2 or 3, characterised in that, viewed in cross-section, an inner contour of the expansion collar is circular, elliptical, polygonal, in particular hexagonal, or polygonal with rounded corners.Arrangement with a connecting element, in particular according to one of the preceding claims, and at least one component connected to the connecting element, characterized in that the connecting element has an annular expansion collar projecting from an underside of the connecting element, and in that the component has a through-opening, wherein the through-opening has at least one widening portion, wherein the expansion collar of the connecting element extends into the through-opening and abuts at least in portions against an inner wall of the widening portion of the through-opening.Arrangement according to claim 5, characterised in that the through-opening has a first, cylindrical section, wherein the widening section adjoins the first section.Arrangement according to claim 5 or 6, characterised in that the widening section is of frustoconical or frustopyramidal configuration.Arrangement according to claim 5, 6 or 7, characterised in that, viewed in cross-section, the widening section is circular, elliptical, polygonal, in particular hexagonal, or polygonal with rounded corners.Arrangement according to Claim 5, 6, 7 or 8, characterized in that an angle (X) which a wall of the widening section assumes with respect to the central longitudinal axis of the through-opening is greater than or equal to eight degrees and less than or equal to 45 degrees.Arrangement according to one of the preceding claims 5 to 9, characterised in that the expansion collar bears against the inner wall of the passage opening over the entire length of the passage opening.Arrangement according to one of the preceding claims 5 to 10, characterised in that a free end of the expansion collar is arranged within the through-opening or is arranged flush with an underside of a section of the component surrounding the through-opening.Arrangement according to one of the preceding claims 5 to 11, characterised in that the through-opening has a large surface roughness at least in the region of the widening section.Arrangement according to Claim 12, characterized in that the through-opening has a first, cylindrical section, the widening section adjoining the first section, a surface roughness in the region of the widening section being greater, in particular being more than twice as great as the surface roughness in the first, cylindrical section.Method for producing a through-opening in a component, wherein the through-opening is provided for inserting a connecting element according to Claim 1, 2, 3 or 4, wherein the through-opening has at least one widening section, characterized byincreating the through-opening during the production of the component by means of punching, by means of forming, in particular by means of 3D printing, casting or injection molding, by forming the through-opening by means of chip-removing methods, in particular drilling and / or milling, or by forming the through-opening by means of chip-less methods.The method of claim 14, characterized bycomprising a first cylindrical portion and an expanding portion adjacent to the first portion when forming the through hole, the cylindrical portion extending from the beginning of the through hole and the expanding portion extending to the end of the through hole.Method according to claim 14 or 15, characterised in that an angle (X) which a wall of the widening section assumes with respect to the central longitudinal axis of the through-opening is greater than or equal to eight degrees and less than or equal to 45 degrees.Method according to claim 14, 15 or 16, characterised byengaging the through-opening by means of punching using a punch and a die, wherein the component is accommodated in sections between the punch and the die and wherein a cutting gap between the die and the punch is 7.5% to 20%, in particular 10% to 15%, of the component thickness.Method according to claim 17, characterised bycalculating a rough surface structure on the inner wall of the through-opening at least in the region of the widening section, in particular by means of producing a forced fracture in the region of the frustoconical widening section during punching of the through-opening.Method for inserting a connecting element into a through-opening of a component, wherein the connecting element has an annular expansion collar projecting from an underside of the connecting element, wherein the expansion collar is designed such that it can be expanded in the radial direction by means of plastic deformation, wherein the through-opening has at least one expanding section, characterized bythe steps: inserting the expansion collar of the connecting element into the through-opening in the component, such that the expansion collar is arranged at least in sections radially within the expanding section of the through-opening, and expanding the expansion collar until an outer side of the expansion collar abuts circumferentially at least in sections against a wall of the expanding section of the through-opening.Method according to claim 19, characterised byengaging the through-opening in the component by means of punching using a punch and a die, wherein a cutting gap between the punch and die is between 7.5% and 20%, in particular between 10% and 15%, of the thickness of the component in the region of the through-opening to be produced.Method according to claim 19 or 20, characterised by stamping an annular depression by means of the die into an underside of the component facing the die and into an underside of the expansion collar facing the die, wherein the depression is stamped along a contact line between connecting element and component on the underside of component and expansion collar.Method according to claim 21, characterised by-material-bonding of the connecting element and the component in the region of the annular depression.

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