COMPOSITE OF AT LEAST TWO COMPOSITE PARTS AND A METHOD FOR PRODUCE A FORM-FITTED AND / OR FORCE-FITTED COMPOSITE.

Description

[0001] The invention relates to a component assembly of at least two components and a method for producing a component assembly joined by form and / or force.

[0002] With the increasing use of lightweight materials in vehicle construction, such as light metals (e.g., aluminum, magnesium and their alloys) or fiber-reinforced plastics, it is becoming increasingly necessary to join components made of different materials to form composite components. This is problematic due to the differing material properties and pushes many established joining processes to their limits.

[0003] For joining aluminum and steel components, it is known from the prior art to use joining aids that are inserted into a first component in the manner of a rivet and are weldable to the material of the second component. The component assembly is then produced by joining the second component to the joining aid by resistance spot welding. For example, reference is made to patent DE 100 15 713 A1 and US 2011 / 0097142 A1. A disadvantage of this method is that the component assembly must be accessible from both sides for the welding process.

[0004] Furthermore, it is known to produce a component joint by means of force-fit or form-fit connections, such as screwing, riveting, clipping, etc. For example, EP 0 390 685 A1 discloses a component joint in which two components are riveted together through through-holes using a rivet element. DE 36 40 484 A1 discloses a method for producing a component joint in which two thin-walled components are joined together by pressing a shear pin or rivet. US 2 995 821 A discloses another rivet joint. Depending on the material of the components to be joined, these methods are also of limited use and do not achieve the required strengths.

[0005] The publication DE 10 2012 203 878 B3 shows a component connection between a first and a second component. A first male fixing element is arranged in the first component, which engages in an opening in the second component designed as a female fixing element.

[0006] Document WO 91 / 11625 A1 discloses a method for joining materials using a riveting device comprising a plug and a sleeve. The sleeve has a circumferential recess, in particular a groove, on its outer surface to form a folding zone, while the plug has a head capable of deforming the pipe end. During riveting, the circumferential recess of the sleeve protects the point of countersinking from stress, and the folding of the sleeve creates a large bearing surface in perfect contact with the materials.

[0007] CN 1 268 211 A shows a component assembly in which an joining aid is inserted into an aluminium component and connected to another component by means of a screw connection.

[0008] Against this background, the object of the present invention is to provide a method for producing a component composite that can be used for a wide variety of material combinations and is improved or at least has an advantage over the prior art.

[0009] The problem is solved by a component assembly according to claim 1 and a method according to claim 9. Further advantageous embodiments are described in the dependent claims and the following description.

[0010] A component assembly consisting of a first component and at least one second component, joined at at least one joint, is described. At the joint, a first joining aid with a retaining section is pressed into a through-hole in the first component, and a fastening receptacle is formed at the joint on the second component. The first joining aid further comprises a fastening section that engages positively and / or non-positively with the fastening receptacle of the second component.

[0011] The proposed design of the component assembly allows for maximum flexibility regarding the materials of the components to be joined. The joining aids can be largely coordinated with each other in terms of the material and shape of their fastening section or fastening receptacle, independent of the component materials. The insertion of the joining aids can be carried out independently of the actual joining process of the components. For joining the components, access from only one side may then suffice.

[0012] In an unclaimed embodiment, the fastening receptacle can be formed in the base material of the second component. According to the invention, the fastening receptacle is part of a second joining aid element, which is pressed into a through-hole in the second component at the joining point with a retaining section.

[0013] The through-hole can be formed, for example, by cutting or punching and preferably has a closed hole or cut contour. The through-hole is bounded by a border region at each of the component surfaces. The joining aid is positively and / or force-fit connected to the first component transversely to the joining axis. The hole geometry of the through-hole and the outer geometry of the joining aid are at least partially matched.

[0014] According to the invention, at least one edge region of the hole wall of the through-hole in the first component, the second component, or both components has a circumferential indentation into which the retaining section of the joining element engages and is preferably pressed in. In the area of ​​the indentation, the hole cross-section is enlarged; for example, the diameter of the through-hole is increased in the area of ​​the chamfer. The pressed-in retaining section of the joining element forms an undercut in the area of ​​the indentation, which positively secures the joining element in one direction against being pushed through the through-hole. Contrary to the assumption that the reduced component thickness in the area of ​​the indentation would adversely affect the strength of the connection, it has been shown that surprisingly high strengths can be achieved.The suspected cause is the embossing process, which results in material hardening at the edge of the indentation. This hardening is further enhanced by the subsequent pressing in of the retaining element. Furthermore, it was found that the embossing also reduces hydrogen embrittlement and counteracts edge cracking susceptibility in this area.

[0015] The indentation can be unilateral. The indentation can extend, for example, up to 20% of the depth of the through-hole, up to 40%, or up to half the depth of the through-hole. It can also be advantageous if the indentation extends more than 50%, and particularly more than 60%, of the depth of the through-hole.

[0016] It has proven particularly advantageous if, in one embodiment, the indentation is designed as a circumferential chamfer. In the chamfered area, the hole wall is inclined relative to the longitudinal axis of the through-hole, and the diameter of the through-hole increases continuously towards the edge of the through-hole in the chamfered area. In the chamfered area, the hole wall can be inclined, for example, at an angle relative to the longitudinal axis of the through-hole, which lies in the range of 30 to 60 degrees or in the range of 40 to 50 degrees, and can particularly be 45 degrees.

[0017] According to the invention, this effect is utilized on both sides of the component(s), for which purpose a circumferential indentation or chamfer is embossed on both edge regions of the hole wall, into which the retaining section of the joining aid engages. The indentations or chamfers can be symmetrically formed, so that identical indentations or chamfers are formed on both sides of the through-hole, or they can be asymmetrically formed, i.e., with different shapes or angles and / or over different depths.

[0018] The through-hole and / or indentation can, for example, have a circular cross-section or alternative cross-sections. For instance, the application of an adhesive can be facilitated if the cross-section of the hole and / or indentation has a serrated or polygonal shape, or if the through-hole with indentation is crown-shaped.

[0019] The retaining section of the joining element is defined as that section of the joining element which can transmit a force to the component under load. Advantageously, the thickness of the retaining section in the pressed-in state can be less than or essentially equal to the thickness of the component. The phrase "essentially equal" in this context means that the thickness of the retaining element after pressing in can be equal to the thickness of the component or, due to manufacturing processes, for example, a few tenths of a millimeter thicker than the component thickness. The through-hole with indentation or embossed chamfer allows the retaining element to be fixed in the component in a form-fit and force-fit manner along the joining axis, so that the retaining section can, for example, be designed without a head, i.e., without a section projecting laterally beyond the diameter of the through-hole.Advantageously, the holding section can have a geometry that is easy to manufacture and can, for example, be cylindrical.

[0020] In In one embodiment, the retaining section of the first joining aid, the retaining section of the second joining aid, or both retaining sections are completely enclosed within the through-hole, meaning that force transmission between the respective component and the retaining section occurs exclusively at the wall of the through-hole. For this purpose, the retaining section can, for example, end flush with the component surfaces or be recessed into the through-hole relative to them.

[0021] Furthermore, when pressing the joining aid element into the component, an additional intermediate layer element, e.g. a film to prevent contact corrosion or an adhesive layer, can be inserted between the holding section and the hole wall.

[0022] The joining aid element can also be materially bonded to the intermediate layer element and / or the component into which it is pressed.

[0023] The force-fit or form-fit connection between the components is achieved indirectly via the fastening section and the fastening receiving section, which are in engagement with each other. InIn one embodiment, the fastening section of the first joining element and the fastening receiving section of the second joining element act as connecting partners in the manner of a clip connection. When joining a clip connection, one or both of the connecting partners are typically elastically deformed so that they can move past each other and then snap into place. Such a connection is very stable and can nevertheless be designed to be detachable. Advantageously, joining a clip connection does not require special tools but can be achieved, for example, by a movement that brings the components together.

[0024] InIn an alternative embodiment, the fastening section of the first joining element is permanently pressed into the fastening receptacle of the second joining element. "Permanently" means that the component connection can only be separated by destroying or damaging the joining elements or components. The fastening section can be pressed in, for example, using a suitable pressing tool, similar to riveting. For this purpose, the fastening section can be designed, for example, as a pin-shaped element or a compression tube, and the fastening receptacle, for example, as a recess with an undercut. It is also possible that an adhesive bond or similar bonding mechanism is provided. The fastening section and fastening receptacle can be formed, for example, before the pressing process or during the pressing process using a suitably shaped pressing tool.

[0025] The components can preferably be made of sheet metal, such as steel, aluminum, or magnesium, or of a sheet-like material, such as fiber-reinforced plastic (e.g., carbon, glass, or aramid fiber reinforced), or they can be organosheets. In principle, they can also be cast parts or profiles with a sheet-like finish at the joint. The component connection described above is particularly suitable, for example, for material thicknesses in the range of 0.5 mm to 5 mm, and especially for thin sheets or sheet metal with a thickness of 2.99 mm or less.

[0026] In an advantageous embodiment, the first and / or second component is made of a lightweight material, such as aluminum (alloy) or fiber-reinforced plastic, and the joining aids are made of steel.

[0027] According to the invention, the components are part of a vehicle body. Preferably, the component assembly is a prefabricated component (sandwich component). However, it can also be, for example, a chassis component or an interior component.

[0028] The component assembly can have a single joining point; however, the components are preferably joined at several joining points. These joining points can be identical or different.

[0029] The component assembly may also include a third or further components, which are also joined using the described method or by means of other known joining methods.

[0030] Furthermore, a method for producing a component composite of at least two components joined at at least one joint is described. The method comprises the steps in the following order: Creating a through-hole at at least one joining point in a first component, pressing a first joining aid element into the through-hole in the first component such that a retaining section of the first joining aid element is connected to the hole wall by force and / or form locking, wherein the joining aid element further comprises a fastening section, inserting a fastening receiving section into at least one joining point in a second component, positioning and aligning the first component relative to the second component, and bringing together the fastening section and the fastening receiving section so that they interlock by force and / or form locking.

[0031] In an unstressed configuration, the fastening receptacle can be formed directly in the base material of the second component, e.g. by creating a recess or similar.

[0032] According to the invention, inserting the fastening receptacle into the second component comprises the following further steps: Creating a through hole at at least one joining point in the second component, pressing a second joining aid element into the through hole in the second component such that a retaining section of the second joining aid element is connected to the hole wall by force and / or form locking, wherein the second joining aid element further comprises the fastening receiving section.

[0033] The through-hole can be formed, for example, by punching or cutting. If the component is made of fiber-reinforced plastic (FRP), the through-hole can also be formed during the component manufacturing process, for example, during the pressing of the component blank.

[0034] According to the invention, an indentation or chamfer is embossed in an edge region of the through-hole in the first component, the second component, or both components. The embossing can be carried out, for example, using a suitably shaped embossing tool. This can be done simultaneously with the creation of the through-hole or in a separate manufacturing step, for example, before or after the creation of the through-hole. In the case of a fiber-reinforced composite (FRP) component, the indentation can, for example, be formed during the manufacturing of the FRP component, e.g., during the compression molding of the component blank. Such an indentation also achieves the described strengthening due to an increased fiber volume fraction in the edge region of the through-hole.

[0035] If the through-hole is formed in a metal component, it can be advantageous in one embodiment if the indentation or chamfer is formed before the through-hole itself. The indentation or chamfer creates a notch in the metal component, whereby any existing component coating or oxide layer on the notch surfaces is at least partially retained.

[0036] Furthermore, when pressing the joining aid into the component, an additional protective layer, e.g. a film to prevent contact corrosion, can be inserted between the joining aid and the hole wall.

[0037] With this method, the components can be pre-attached and then further joined using additional joining methods. It is also possible for the component assembly to be formed solely by the method described above, with the components preferably being joined at multiple points.

[0038] If an additional layer is introduced between the joining aid and the component (e.g., for electrochemical separation or an adhesive layer), a material-bonded connection can be achieved through pressing and / or heat treatment. The heat treatment can be performed before, during, or after the pressing-in process.

[0039] The joining aid is pressed in, for example, using a suitable tool, such as a press tool or C-clamp. For this purpose, the retaining section is inserted into the corresponding through-hole and pressed in place, whereby the material of the retaining section is permanently deformed and pressed firmly against the hole wall. Furthermore, in one embodiment, the material of the retaining section may also flow into the embossed or chamfered area, forming an undercut there. The joining aid is thus also positively fixed in the component along the joining axis F.

[0040] In an unclaimed embodiment, the through-hole and / or the indentation is not created in a separate step, but rather by the insertion of the joining aid itself. The through-hole can be created, for example, by driving a self-tapping joining aid into the component, e.g., by rotary impact. Likewise, the joining aid can be a pre-formed element, e.g., in the form of a threaded bushing or Helicoil.

[0041] If a circumferential indentation or chamfer is embossed on both edges of the hole wall in a given design, it can be produced as described for the first indentation or chamfer. When the retaining section is pressed into the through-hole, the retaining section then forms an undercut at both indentations or chamfers, which secures it in the through-hole.

[0042] The positioning, alignment and joining of the components can preferably be automated, e.g. with a suitably programmed handling device.

[0043] The process is used to produce the component composite described above, so that the same technical effects and advantages are achieved as described therein.

[0044] The invention has, among other things, the following advantages: The process enables the cost-effective and reproducible production of component composites and assemblies, particularly in hybrid construction. The component composite can be designed to be detachable. Joining the component composite is possible even with access from only one side. The thickness of the component composite can be reduced to the thickness of the components to be joined. The component connection can be weight-neutral or weight-advantageous compared to known joining methods. The joining method according to the invention is particularly suitable for thin sheet metal connections. It enables simple joining of components in the press shop.

[0045] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more easily understood with reference to the drawing and in conjunction with the following description of exemplary embodiments. Where the term "may" is used in this application, it refers to both the technical possibility and the actual technical implementation.

[0046] The following are examples of implementation explained with reference to the accompanying drawings. These show, in schematic representation: Figure 1 shows a sectional view of a first exemplary component assembly. Figure 2A, 2 shows the procedure for manufacturing the component assembly, and Figures 3 to 7 show sectional views of further exemplary component assemblies.

[0047] Figure 1Figure 1 shows a cross-sectional view of the joining point of a component assembly 1, which comprises two components 2 and 3. The component assembly 1 is manufactured using the method according to the invention. The component assembly 1 can have several such joining points, which may be identical or different in design.

[0048] The first component 2 is made of an aluminum sheet. The term "aluminum" also includes the corresponding aluminum alloys. The second component 3 is also made of an aluminum sheet. The two components 2 and 3 are indirectly joined at the joint by means of a first joining element 4, which is pressed into the first component 2, and a second joining element 5, which is pressed into the second component 3. The two joining elements 4 and 5 are connected to each other by a force-fit and form-fit connection. The first and second joining elements 4 and 5 are made of a steel material.

[0049] Figure 2a and2b show steps in the manufacturing process.

[0050] In the first component 2 and the second component 3, a through hole 6, 7 is formed at the joint. In the edge regions of the hole wall, a circumferential indentation 8, 9 or 10, 11 in the form of a chamfer is embossed.

[0051] The first joining aid 4 is pressed into the first component 2. The first joining aid 4 has a headless retaining section 12 with a cylindrical shape and a fastening section 13. The retaining section 12 secures the first component 2, while the fastening section 13 serves for subsequent connection to the second joining aid 5 in the second component 3.

[0052] The cylindrical retaining section 12 is inserted into the first through-hole 6 and pressed in place with a suitable pressing tool, whereby the material of the retaining section 12 is permanently deformed and pressed firmly against the hole wall. In addition, the material of the retaining section 12 flows into the chamfered area and forms an undercut 14, 15 there (see figure). Figure 2B The first joining aid 4 is thus also positively fixed in the first component 2 in the direction of the joining axis F. A cylindrical metal slug is used as an example as the second joining aid 5. The cylinder wall forms the holding section 16, and the fastening receiving section 17 is formed by a recess projecting into the interior of the metal slug with a recess 18.

[0053] The pressing of the second joining aid 5 into the second component 3 is carried out as described above for the first joining aid 4. Two undercuts 19, 20 are also formed, which positively lock the second joining aid 5 in the joining direction F in the second component 3.

[0054] The retaining sections 12 and 16 are fully integrated into the first component 2 and the second component 3, respectively; that is, they do not rest on a surface of the component, but only on the hole wall within the component. The fastening section 13 protrudes from the first component 2. The fastening section 13 and the fastening receptacle section 17 can be formed before pressing in, or alternatively, they can be formed during the pressing in of the joining aid element 4 or 5, for example, by deforming part of the retaining section.

[0055] To create the component assembly, the components are brought together so that the fastening section 13 and the fastening receptacle section 17 engage with each other. With reference to Figure 2B The pin-shaped fastening section 13 is pressed into the fastening receiving section 17 and plastically deformed, forming an undercut at the recess 18 for a permanent positive connection of the components 2, 3.

[0056] Figure 3 Figure 1 shows an alternative embodiment of the component assembly 1. The fastening receptacle in the second joining aid 5 is designed as a through-opening, and the fastening section 13A of the first joining aid 4 projects through the second joining aid 5. During pressing, the fastening section 13A forms a head section 21 on the exit side, which projects laterally beyond the through-opening and creates a positive fit.

[0057] In a further embodiment, the component assembly 1 can also be designed such that the fastening section 13B is flush with the second joining aid element 5, as shown in Figure 4 depicted.

[0058] Instead of the one in the Figures 1 to 4 The component assembly 1 can also be formed by a type of clip connection using the fastening section 13, 13A, 13B shown, which is deformed by pressing. For this purpose, for example, the fastening section 13C can be used, as shown in Figure 5 The clip connection is shown to be designed with two arms 22, 23 which initially deform elastically when inserted into the mounting section 17 and engage in the recess 18 in their final position. Such a clip connection has the advantage that it can be designed as a detachable connection. The clip connection can be flush with the component surface or project beyond it.

[0059] To form an unstressed component composite, the fastening receiving section can also be formed directly in the base material of the second component; then the introduction of a second joining aid element can be dispensed with. Figure 6 shows an example of such a component assembly 1, in which the second component 3 has a fastening receptacle section 17D. In The form of a through hole is formed and the fastening section 13D of the joining aid element 4 in the first component 2 protrudes through the through hole 17D and is pressed into it in a form-fit and force-fit manner.

[0060] The shape of the indentation is not limited to the chamfer geometry shown; rather, variations are possible, such as the one in Figure 7 The dome-shaped or trough-shaped indentations 24, 25 and 26, etc., are shown. The retaining section can flow into the indentations by pressing, as shown in Figure 7shown for component 3, or already have a shape before pressing that lies undercut against the indentation, such as the one shown in Figure 7 The joining aid element 4 shown has a widened head section 27 in the area of ​​the holding section.

[0061] Components 2 and 3 can also be made of other materials, such as a different lightweight material like a fiber-reinforced plastic, or of steel. Similarly, other materials can be used for the joining elements 4 and 5. The component assembly can connect components made of the same material or components made of different materials. Furthermore, the component assembly can comprise more than the two components shown. For example, two components can first be joined together using a joining element in the manner of a rivet connection, and then the described component assembly can be created with another component using a further joining element. Additional components can also be joined to the component assembly in other ways. For example, another component, such as a steel component, can be connected to the first or second joining element using resistance spot welding.

[0062] The distance shown between the components is not required. In a component assembly, the components can also rest directly on top of each other.

[0063] In contrast to conventional component assemblies with joining aids, a significantly lower height of the component assembly can be achieved, since the joining aids can be flush with the workpiece surfaces if required.

[0064] Similarly, when pressing the joining aid element into the component, an additional protective layer (not shown), e.g. a film to prevent contact corrosion, can be inserted between the joining aid element and the hole wall.

[0065] Although the figures show two symmetrical chamfers, the chamfers can be asymmetrical.

[0066] For illustrative purposes, the figures depict the contour of the hole wall as if the inclined hole wall transitions directly into a vertical hole wall section in the chamfer area. In reality, however, a collar-shaped, circumferential plateau may be formed between the inclined wall section and the vertical wall section, due to the geometry of the die.

[0067] Very high strengths are achieved through the embossed chamfer in the through-hole and the pressed-in joining element. For example, in a test, a through-hole with a diameter of 12 mm was formed in the core of a 2.5 mm thick sheet of 5000 series aluminum alloy (basic strength of 120 to 140 N / mm²). A chamfer was embossed at the edges at a 45-degree angle with an embossing depth of 0.7 mm and a plateau width of 0.4 mm. A cylindrical sheet metal plug made of S355 steel, 4 mm thick and with a diameter of 11.7 mm before pressing, was pressed into the through-hole. After pressing, the pull-out forces for the plug ranged from 8.5 to 12.6 kN on each side.

[0068] The exemplary embodiments are not to scale and are not limiting. Variations within the scope of the invention, as defined by the claims, are possible.

Claims

1. Component assembly which is part of a vehicle body, of at least two components (2, 3) which are joined at at least one joining point, comprising: a first component (2), wherein at the joining point a first auxiliary joining element (4) with a retaining portion (12) is pressed into a through-hole (6) in the first component (2), and a second component (3), in which at the joining point a fastening receiving portion (17) is formed, wherein the first auxiliary joining element (4) further comprises a fastening portion (13) which engages in a form-fitting and / or force-fitting manner in the fastening receiving portion (17) of the second component (3), and wherein the fastening receiving portion is part of a second auxiliary joining element (5) which is pressed at the joining point with a retaining portion (16) into a through-hole (7) in the second component, wherein the through-hole (6, 7) in the first component (2) and / or in the second component (3) is widened in at least one edge region by a circumferential impression (8, 9, 10, 11) into which the retaining portion (12) of the auxiliary joining element (4, 5) is pressed, and wherein the through-hole is widened in both edge regions by one impression (8, 9, 10, 11) each.

2. Component assembly according to claim 1, wherein the impression (8, 9, 10, 11) is formed as a chamfer.

3. Component assembly according to one of the preceding claims, in which the retaining portion (12, 16) of the first auxiliary joining element (4) and / or of the second auxiliary joining element (5) is completely received in the through-hole (6, 7).

4. Component assembly according to one of the preceding claims, wherein between retaining portion (12; 16) and the component (2, 3) into which the retaining portion is pressed, an intermediate layer element is further introduced.

5. Component assembly according to one of the preceding claims, wherein the retaining portion (12; 16) is additionally connected in a materially bonded manner to the intermediate layer element and / or the component (2, 3) into which the retaining portion is pressed.

6. Component assembly according to one of the preceding claims, wherein the fastening portion (13C) and the fastening receiving portion (17) cooperate in the manner of a clip connection.

7. Component assembly according to one of the preceding claims, wherein the fastening portion (13) is pressed in a non-releasable manner into the fastening receiving portion (17).

8. Component assembly according to claim 7, wherein the first and / or second component (2, 3) are formed from a lightweight construction material and the auxiliary joining elements (4, 5) are formed from steel.

9. Method for producing a component assembly (1) which is part of a vehicle body, of at least two components (2, 3) which are joined at at least one joining point, with the following steps in the following sequence: a) producing a through-hole (6) at at least one joining point in a first component (2), b) pressing a first auxiliary joining element (4) into the through-hole (6) in the first component (2) such that a retaining portion (12) of the first auxiliary joining element (4) is connected in a force-fitting and / or form-fitting manner to the hole wall, wherein the auxiliary joining element (4) further comprises a fastening portion (13), d) introducing a fastening receiving portion (17) at at least one joining point in a second component (3), wherein producing the fastening receiving portion (17) in the second component further comprises the steps: c1) producing a through-hole (7) at at least one joining point in the second component (3), c2) pressing a second auxiliary joining element (5) into the through-hole (7) in the second component (3) such that a retaining portion (16) of the second auxiliary joining element (5) is connected in a force-fitting and / or form-fitting manner to the hole wall, wherein the second auxiliary joining element (5) further comprises the fastening receiving portion (17), d) positioning and aligning the first component (2) relative to the second component (3), and e) bringing together fastening portion (13) and fastening receiving portion (17) such that they engage in a force-fitting and / or form-fitting manner with one another, wherein before pressing the respective auxiliary joining element (4, 5) into the first component (2) and / or the second component (3), a circumferential impression is produced such that the respective through-hole (6, 7) is widened in at least one edge region and the retaining portion (12, 16) of the auxiliary joining element (4, 5) is pressed into the impression and after pressing forms an undercut (14, 15, 19, 20) at the impression (8, 9, 10, 11).