FUNCTIONAL ELEMENT, ASSEMBLY AND METHOD FOR MANUFACTURING AN ASSEMBLY

Description

[0001] The invention relates to a functional element for pressing into a workpiece, in particular into a sheet metal part, an assembly comprising a workpiece with a hole, in particular a sheet metal part, and such a functional element, as well as a method for manufacturing the assembly.

[0002] These elements typically feature a functional section that serves to attach further components. They are widely used, among other things, in automotive engineering.

[0003] Functional elements can be bolt elements, whose shaft may be threaded, or nut elements, which, for example, have an internal thread.

[0004] Functional elements are known in various designs. For example, there are rivet elements that have a rivet section which is deformed when attached to a sheet metal part to form a rivet flange and, together with the head, create an annular recess for the edge of a hole in the sheet metal part. With such rivet elements, the functional element is thus deformed when attached to the sheet metal part. Furthermore, press-fit elements are known in which the element itself is not intentionally deformed when attached to a sheet metal part; instead, the sheet metal material itself is deformed to engage with undercuts of the respective press-fit element.

[0005] A functional element suitable for press-fitting is known, for example, from US 8,734,071 B2. CN 103 382 957 A discloses a bolt element with a sealing area that is closed off by a circumferential projection. To seal connections between functional elements and workpieces, especially sheet metal parts, a coating is typically applied to parts of the functional elements that contact the workpiece. This application takes place in a separate manufacturing step, which leads to increased effort and therefore higher costs and increased time requirements. Furthermore, this solution results in increased environmental impact due to the coating.

[0006] It is an object of the present invention to provide a functional element and an assembly component with which a tight connection can be achieved with relatively little effort and with reduced environmental impact compared to previously known solutions.

[0007] This problem is solved by the subject matter of independent claims 1 and 13. Advantageous embodiments are the subject matter of dependent claims.

[0008] The functional element according to claim 1 is suitable for pressing into a workpiece, in particular into a sheet metal part, and comprises a functional section and a fastening section with a stop surface for introducing a pressing force into the functional element, a workpiece contact surface opposite the stop surface which can be brought into contact with the workpiece and is in particular designed in a flange-like manner, and a sealing area located in an axial direction and / or a radial direction of the functional element between the workpiece contact surface and the functional section for receiving displaced material of the workpiece.The sealing area forms a contact surface for the displaced material to seal a connection between the functional element and the workpiece. The mounting section has a projection that defines the axial boundary of the sealing area and has a first flank facing the sealing area and a second flank facing away from the sealing area, both of which are inclined at different angles to the axial direction. The first flank is inclined more steeply to the axial direction than the second flank, which is inclined at approximately 15° to 35° to the axial direction. The workpiece contact surface has a protrusion that, viewed in cross-section, is wedge-shaped, at least in some sections.

[0009] The projection can be provided circumferentially around the shaft of a functional element designed as a bolt element and can also be referred to as a lip. The projection preferably extends radially outwards and comprises at least the first flank and the second flank. In particular, the first flank can form at least part of the contact surface, especially the second partial surface.

[0010] The projection creates an undercut that seals the sealing area and securely holds the functional element in the workpiece. The displaced workpiece material can thus be axially trapped between the workpiece contact surface or the pressure surface on one side and the projection on the other. Simultaneously, the projection, particularly its first flank, can also form part of the pressure surface to achieve a high sealing effect.

[0011] Because the first flank is inclined more strongly to the axial direction than the second flank, the effect of the undercut, i.e. the retention of the functional element in the workpiece, is improved, and, on the other hand, the insertion of the functional element into the workpiece is made easier in the insertion direction in which the second flank protrudes.

[0012] In particular, the first flank can be inclined at approximately 50° to approximately 70°, especially approximately 60°, to the axial direction.

[0013] In a preferred embodiment, the second flank is inclined at approximately 25° to the axial direction.

[0014] The first flank and the second flank can advantageously be connected by a connecting section in which the projection has a constant diameter, so that the shape of the projection can be adapted to the specific circumstances, in particular the sheet thickness of the workpiece, without impairing the function of the flanks. In this embodiment, the connecting section thus extends in the axial direction. Preferably, the connecting section can extend over approximately 20% to approximately 70%, and more particularly approximately 40%, of the axial extent of the projection.

[0015] In particular, the fastening section, e.g., the workpiece contact surface, has at least one anti-rotation feature. Preferably, several anti-rotation features are provided, which are, for example, evenly distributed in the axial and / or circumferential direction. The anti-rotation features ensure that the connection between the functional element and the workpiece can withstand a torque load subsequently applied via the functional section. The anti-rotation features can be arranged in a recess or a circumferential groove of the fastening section, in particular a head of the functional element, which comprises the stop surface and / or the workpiece contact surface.

[0016] The anti-rotation features can be designed as radially and / or axially extending ribs or grooves. In particular, the anti-rotation features are uniformly arranged and extend at equal angular intervals to each other in the radial direction.

[0017] The workpiece mounting surface can have a depression, in particular a ring depression, wherein the first partial surface can extend into and / or transition into the depression.

[0018] The workpiece contact surface has a raised section which, viewed in cross-section, is at least partially wedge-shaped. The wedge shape preferably slopes down towards the first partial surface. The first partial surface may transition into the raised section.

[0019] One function of the elevation can be to support the displacement of material from the workpiece into the sealing area when the element interacts with the workpiece.

[0020] The anti-rotation features – if present – ​​may be located in the recess and / or on the raised area.

[0021] The recess can be directed in the opposite direction to the insertion direction of the functional element, so that the material of the workpiece is, at least partially, displaced into the recess during insertion and is pressed against the first partial surface of the contact surface.

[0022] In an advantageous embodiment, the workpiece contact surface transitions into the first sub-surface.

[0023] The invention further relates to an assembly component comprising a workpiece, in particular a sheet metal part, wherein a functional element according to at least one of the embodiments described above is pressed into a hole pre-formed in the workpiece or a hole punched by the functional element. The functional element according to the invention is pressed into the hole in such a way that material from the workpiece displaced by or after pressing is received in the sealing area and lies tightly against the contact surface.

[0024] In particular, the displaced material of the workpiece lies against the projection or at least partially or completely surrounds the projection.

[0025] The thickness of the workpiece can be less than or essentially equal to the axial extent of the sealing area, at least in the area of ​​the hole. Alternatively, the thickness of the workpiece can also be greater than or essentially equal to the axial extent of the sealing area, at least in the area of ​​the hole.

[0026] According to a further aspect, the invention also relates to a method for manufacturing an assembly component according to the invention, as per claim 13, which comprises the following

[0027] The steps include: Providing a functional element according to the invention, providing a workpiece, in particular a sheet metal part, and inserting the functional element into a pre-made hole in the workpiece or into a hole punched by the functional element and introducing a pressing force into the stop surface so that the workpiece contact surface is brought into contact with the workpiece, and displacing material of the workpiece into the sealing area so that the material is pressed against the contact surface to create a tight connection between the functional element and the workpiece.

[0028] According to one embodiment, the functional element is self-punching, so that pre-punching of the workpiece is unnecessary.

[0029] The displacement of the material can be achieved by pressing a die against a surface of the workpiece facing away from the workpiece contact surface. The die is designed to displace the workpiece material into the sealing area, so that the material is pressed against the contact surface to create a tight seal between the functional element and the workpiece.

[0030] In this process, the workpiece rests on a support that includes a suitable die. The applied pressing force then also serves to displace the material. However, it is also possible to press the die against the surface of the workpiece facing away from the workpiece contact surface during or after the insertion of the functional element into the hole and / or the application of the pressing force, in order to displace material from the workpiece.

[0031] The displacement of the workpiece material can also be caused by components of the element's head during pressing.

[0032] The invention is explained below by way of purely exemplary descriptions using advantageous embodiments. The drawings, which schematically illustrate the exemplary embodiments, show... Fig. 1 a perspective view of a functional element designed as a press-fit bolt according to an embodiment outside the claimed scope of protection, Fig. 2 a further perspective view of the functional element made of Fig. 1 , Fig. 3a a half section of the functional element made of Fig. 1 , Fig. 3-legged detail view of area A according to Fig. 3a Fig. 4 a detailed view of a sealing area of ​​a functional element designed as a press-fit bolt according to a further embodiment outside the claimed scope of protection, Fig. 5 a detailed view of a sealing area of ​​a functional element designed as a press-fit bolt according to a further embodiment outside the claimed scope of protection, Fig. 6 a half-section of an assembly component according to an embodiment outside the claimed scope of protection, with a press-fit bolt as a functional element, Fig. 6 a detailed view of area B according to Fig. 6a , Fig. 7a a half-section of an assembly component according to a further embodiment outside the claimed scope of protection, with a press-fit bolt as a functional element, Fig. 7a a detailed view of area C according to Fig. 7a , Fig. 8a a half-section of an assembly component according to a further embodiment outside the claimed scope of protection, with a press-fit bolt as a functional element, Fig. 8a a detailed view of area D according to Fig. 8a Fig. 9 a perspective view of a functional element designed as a parent element according to an embodiment of the invention; Fig. 10 a further perspective view of the functional element made of Fig. 9 , Fig. 11a a half section of the functional element made of Fig. 9 , Fig. 11 leg detail view of area E according to Fig. 11a , Fig. 12a a half-section of an assembly component according to an exemplary embodiment with a mother element as a functional element and Fig. 12b a detailed view of area F according to Fig. 12a .

[0033] Out of Fig. 1 und 2 Each functional element 10 designed as a press-fit bolt with flange is visible, and Fig. 9 und 10 Figure 10 shows a functional element 10 designed as a mother element, which has a functional section 11 and a fastening section 13. The fastening section 13 is the section of the functional element 10 by which the functional element 10 is fastened to a workpiece 50, which will be described in more detail later. The functional elements 10 each have a head 43. The functional element 10 designed as a press-fit bolt according to Fig. 1 und 2 It also has a shaft 41 on which a thread 45 (external thread) is formed. The functional element 10, designed as a nut element, has an internal thread 45 (see Fig. 11a ) provided.

[0034] Each head 43 has a stop surface 15 for introducing an insertion force into the functional element 10 and a flange-like workpiece contact surface 17 opposite the stop surface 15. In an axial and / or radial direction of the functional element 10, a sealing area 19 is located between the workpiece contact surface 17 and the functional section 11, which has a contact surface 21 for displaced material of the workpiece 50 in order to seal a connection between the functional element 10 and the workpiece 50.

[0035] The shaft 41 of element 10 of the Fig. 1 und 2 extends from the side facing away from the stop surface 15. However, it is also possible to position the shaft at the stop surface 15 (which would then be ring-shaped for a shaft with a round cross-section). With an otherwise unchanged design of the fastening section 13, the sealing area 19 is also located between the workpiece contact surface 17 and the functional section 11 in an axial view.

[0036] The design of the contact surface 21 is clearly illustrated in Fig. 3a bis Fig. 5 This is shown. It comprises a conical first partial surface 23, which extends obliquely to the axial direction of the functional element 10 and converges in a press-in direction E of the functional element 10, and a conical second partial surface 25, located between the first partial surface 23 and the functional section 11 in the press-in direction E, which connects to the first partial surface 23 by means of a rounded transition area 27, also extends obliquely to the axial direction of the functional element 10, and diverges in the press-in direction E of the functional element 10. Specifically, the first partial surface 23 can be inclined at approximately 20° to approximately 40°, in particular approximately 30°, to the axial direction, and the second partial surface 25 can be inclined at approximately 50° to approximately 70°, in particular approximately 60°, to the axial direction. As shown, for example, in Fig. 3b and Fig. 4 As can be seen, the two sub-areas 23 and 25 can be approximately perpendicular to each other. Alternatively, the angle between the sub-areas 23 and 25 can be as shown in Fig. 5 shown, can also be larger than 90°, up to about 135°.

[0037] As the exemplary embodiment in Fig. 11a bis 12b As clearly shown, the contact surface 21 of the functional element 10, designed as a parent element, also comprises a first sub-surface 23 and a conical second sub-surface 25, which connects to the first sub-surface 23 by means of a rounded transition area 27, runs obliquely to the axial direction of the functional element 10, and diverges when viewed in the press-in direction E of the functional element 10. In the present example, the first sub-surface 23 runs approximately parallel to the press-in direction E; however, the functional element 10 can also be designed such that the first sub-surface 23 runs obliquely to the axial direction and converges when viewed in the press-in direction E, as shown in Fig. 11b indicated by dashed lines.

[0038] The press-in direction E denotes the direction in which the functional element 10 is intended to be pressed into the sheet metal part 50. The press-in direction E runs parallel to the axial direction of the functional element 10 from the stop surface 15 towards the workpiece contact surface 17, with the stop surface 15 and the workpiece contact surface 17 being approximately perpendicular to the press-in direction E.

[0039] The contact surface 21, specifically the first sub-surface 23, extends into a (ring) recess 39 of the elements 10, which is incorporated into the head 43, according to the Fig. 1 bis 8b and transitions there into the workpiece contact surface 17. Several radially extending ribs are formed in the recess 39 as anti-rotation features 37. The recess 39 is also directed opposite to the press-in direction E of the functional element 10, so that material of the workpiece 50 can be at least partially displaced when pressed into the recess 39 and thereby conforms to the first partial surface 23.

[0040] Element 10 according to the Fig. 9 bis 11b This recess 39 does not have a recess. Instead, a wedge-shaped projection 40 is provided, which slopes radially inwards and transitions into the first partial surface 23 via a rounded transition section 28. In the illustrated embodiment, the surface 23 has anti-rotation features 37 in the form of axially distributed ribs in the circumferential direction. The projection also preferably has anti-rotation features 37, here by way of example, radially distributed grooves in the circumferential direction.

[0041] The recess 39 and the elevation 40 described above can be combined if required - also in a modified form - and implemented in both a nut element and a bolt element.

[0042] The fastening section 13 also includes a circumferentially radially outwardly extending projection 29, which axially delimits the sealing area 19. The projection 29 has a first flank 31 facing the sealing area 19, on which the second partial surface 25 of the contact surface 21 is formed, and a second flank 33 facing away from the sealing area 19. Unlike the nut element, the projection 29 of the functional element 10, designed as a press-fit bolt, also has an optional connecting section 35 that joins the two flanks 31 and 33. The diameter of the projection 29 varies along its axial extent and, viewed in the press-fit direction E, increases in the region of the first flank 31, remains constant in the region of the connecting section 35, and decreases in the region of the second flank 33. Accordingly, the flanks 31 and 33 run obliquely to the axial direction of the functional element 10.

[0043] How in particular Fig. 4 As shown, the first flank 31 can be inclined more strongly to the axial direction than the second flank 33. This results, on the one hand, in a particularly effective design of the contact surface 21 and an effective undercut by the projection 29. On the other hand, a comparatively small angle or inclination of the second flank 33 facilitates the insertion of the projection 29 into the mold hole.

[0044] Alternatively, the projection 29 can be designed approximately symmetrically, resulting in an equal inclination of the flanks 31, 33 to the axial direction (see, for example, Fig. 3b ), or the first flank 31 may be less inclined to the axial direction than the second flank 33, as for example in Fig. 5 shown. Specifically, the first flank 31 can advantageously be inclined at approximately 50° to approximately 70°, in particular approximately 60°, to the axial direction, and the second flank 33 can be inclined at approximately 15° to approximately 35°, in particular approximately 25°, to the axial direction.

[0045] The interaction of the functional element 10 with the workpiece 50 is particularly evident from Fig. 6a bis Fig. 8b and Fig. 12a und 12b The figures show an assembly component 100 according to the present invention. As shown, the workpiece 50 is in each case designed as a sheet metal part with preferably ductile properties. The workpiece 50 has a surface 51 on which the workpiece contact surface 17 of the functional element 10 rests, and a surface 53 on an opposite side of the workpiece 50. The Fig. 6a, 6b , 7a, 7b Figures 8a and 8b show workpiece 50 having increasing thicknesses T 50 to illustrate that the concept according to the invention can be used for workpieces with a wide variety of properties.

[0046] The functional element 10 is pressed into a shaped hole provided in the workpiece 50, for example, a bore or a pre-punched hole, so that displaced material from the workpiece 50 is received in the sealing area 19 and – if present – ​​in the recess 39, and rests tightly against the contact surface 21. This is simplified by the inclined arrangement of the first partial surface 23, since the material does not have to be pressed as deeply into the sealing area 19 to achieve full contact. Depending on the thickness T 50 of the workpiece 50, the displaced material of the workpiece 50 rests against the projection 29 ( Fig. 6b , Fig. 8b , Fig. 12b ) or even completely encloses it ( Fig. 7b ). This enables the functional element 10 according to the invention to produce excellently sealed assembly parts 100, regardless of the thickness T 50 of the respective workpiece 50.

[0047] To produce the in Fig. 6a bis Fig. 7b The assembly of the components 100 shown can be carried out in particular as follows: First, a functional element 10 according to the invention and a workpiece 50, in particular a sheet metal part in which a shaped hole is provided. Then the functional element 10 is inserted into the shaped hole so that the workpiece contact surface 17 faces the surface 51.

[0048] An induction force is introduced into the stop surface 15, causing the workpiece contact surface 17 to come into contact with the workpiece 50. This induction force can be used to force material from the workpiece 50 into the sealing area 19 and press it against the contact surface 21. For this purpose, a die (not shown in the figures) can be provided on the surface 53 facing away from the workpiece contact surface 17. The induction force presses a punch of the die into the surface 53, forming an annular groove 55 in an area of ​​the workpiece 50 adjacent to the hole. Pressing the punch of the die into the workpiece 50 in an area adjacent to the hole thus displaces material from the workpiece 50, which flows into the sealing area 19 and thereby conforms to the contact surface 21.

[0049] In principle, it is also conceivable to first introduce the element 10 into the workpiece 50 and to effect the step of displacing the material by means of the die in a separate and / or subsequent step.

[0050] In the assembly part 100 of the Fig. 8a, 8ab The displacement of the material is not effected by a die with a punch, but rather the surface 53 of the workpiece 50 rests on a support surface that is essentially flat in the area around the hole. The displacement of the material is achieved here by partially pressing the head 43 into the surface 51. Due to the flat support surface, the material cannot move downwards and is therefore forced into the sealing area 19 until it is in full contact with the first partial surface 23, thus creating a tight seal.

[0051] For assembly part 100 according to the Fig. 12a, 12ab The displacement of the material is effected by the protrusion 40. The head 43 is not pressed into the workpiece 50, but only against its surface 51 until the workpiece contact surface 17 rests against it. In doing so, the protrusion 40 penetrates the workpiece 50. Its radially inwardly sloping wedge shape supports a directed displacement of the material into the sealing area 19.

[0052] It is understood that the above-described concepts of material displacement can be combined if this is useful in the respective application.

[0053] The embodiments shown and described here have in common that they provide a functional element or assembly component which enables a tight connection of an assembly component with minimal effort and without additional sealant. By appropriately selecting the design, in particular the spatial arrangement, extent and / or inclination of the first and second sub-surfaces, the first and second flanks, the transition section and / or the connecting section, the functional element can be adapted to the specific conditions at hand.

[0054] The above embodiments relate to functional elements that can be inserted into pre-drilled workpieces. However, it is also possible for these elements to be self-punching, in particular nut elements or bolt elements whose shank extends from the stop surface. For this purpose, their fastening section can be provided with a punching edge facing the workpiece. Bezugszeichenliste

[0055] 10 Functional element 11 Functional section 13 Mounting section 15 Stop surface 17 Workpiece contact surface 19 Sealing area 21 Contact surface 23 First partial surface 25 Second partial surface 27 Transition area 29 Projection 28 Transition section 31 First flank 33 Second flank 35 Connecting section 37 Anti-rotation feature 39 Recess 40 Raise 41 Shank 43 Head 45 Thread 50Workpiece 51Surface 53Surface 55Ring groove 100 assembly part Press-in direction T 50 Workpiece thickness

Claims

1. A functional element (10) for pressing into a workpiece (50), in particular into a sheet metal part, said functional element (10) comprising a functional section (11); and a fastening section (13) having an abutment surface (15) for introducing a press-in force into the functional element (10); a workpiece contact surface (17) which is disposed opposite the abutment surface (15), which can be brought into contact with the workpiece (50), and which is in particular of a flange-like design; and a sealing region (19) for receiving displaced material of the workpiece (50), said sealing region (19) being disposed between the workpiece contact surface (17) and the functional section (11) in an axial direction and / or a radial direction of the functional element (10) and forming a contact surface (21) for the displaced material to seal a connection between the functional element (10) and the workpiece (50), wherein the fastening section (13) has a projection (29) which bounds the sealing region (19) in the axial direction and which has a first flank (31) facing the sealing region (19) and a second flank (33) which is remote from the sealing region (19) and which extends obliquely and inclined to different degrees with respect to the axial direction, and wherein the first flank (31) is more inclined with respect to the axial direction than the second flank (33), characterized in that the second flank (33) is inclined approximately 15° to approximately 35° with respect to the axial direction, the workpiece contact surface (17) has an elevated portion (40) which is at least sectionally of wedge-shaped design viewed in a crosssection.

2. A functional element (10) according to claim 1, characterized in that the second flank (33) is inclined approximately 25° with respect to the axial direction.

3. A functional element (10) according to claim 1 or 2, characterized in that the first flank (31) is inclined approximately 50° to approximately 70°, in particular approximately 60°, with respect to the axial direction.

4. A functional element (10) according to any one of the claims 1 to 3, characterized in that the first flank (31) and the second flank (33) are connected to one another by a connection section (35) in which the projection (29) has a constant diameter.

5. A functional element (10) according to any one of the claims 1 to 4, characterized in that the first flank (31) forms at least a part of the contact surface (21).

6. A functional element (10) according to any one of the claims 1 to 5, characterized in that the workpiece contact surface (17) has a recess (39), in particular a ring recess.

7. A functional element (10) according to claim 6, characterized in that the first part surface (23) extends into the recess (39).

8. A functional element (10) according to any one of the claims 1 to 7, characterized in that the first part surface (23) merges into the elevated portion (40).

9. A functional element (10) according to any one of the claims 1 to 8, characterized in that the workpiece contact surface (17) merges into the first part surface (23).

10. A component assembly (100) which has a workpiece (50), in particular a sheet metal part, and a functional element (10) according to any one of the claims 1 to 9, wherein the functional element (10) is pressed into a hole prefabricated in the workpiece or into a hole punched by the functional element (10) such that material of the workpiece (50) displaced by the pressing in or after the pressing in is received in the sealing region (19) and tightly contacts the contact surface (21).

11. A component assembly according to claim 10, characterized in that the displaced material of the workpiece (50) contacts the projection (29) or at least partly or completely surrounds the projection (29).

12. A component assembly according to claim 10 or 11, characterized in that a thickness (T50) of the workpiece (50) is smaller than or substantially equal to an axial extent of the sealing region (19) at least in the region of the hole or the thickness (T50) of the workpiece (50) is greater than or substantially equal to an axial extent of the sealing region (19) at least in the region of the hole.

13. A method of manufacturing a component assembly (100) according to any one of the claims 10 to 12, comprising the steps: - providing a functional element (10) according to any one of the claims 1 to 9; - providing a workpiece (50), in particular a sheet metal part; - inserting the functional element (10) into a prefabricated hole in the workpiece or into a hole punched by the functional element (10) and introducing a press-in force into the abutment surface (15) such that the workpiece contact surface (17) is brought into contact with the workpiece (50); and - displacing material of the workpiece (50) into the sealing region (19) such that the material is pressed against the contact surface (21) to establish a sealed connection between the functional element (10) and the workpiece (50).