Process for producing a steel component composite and steel component composite

Abstract

Method for producing a steel component composite (1), in which - a steel component (2) is provided with a predetermined breaking point (3), - the predetermined breaking point (3) of the steel component (2) is punched through to form an opening (6) by means of a press-in element (5), - the press-in element (5) is pressed into the opening (6) of the steel component (2), - a component (7) is bonded to the steel component (2) by means of a surface-applied adhesive (8), at least in overlap with the press-in element (5), and - by means of a flow drilling element - a flow hole (9) is melted through the press-in element (5) and the component (7), which flow hole extends through the press-in element (5), the steel component (2) and the component (7) in overlap.

Description

[0001] The invention relates to a method for producing a steel component composite and to a steel component composite.

[0002] WO 2016 / 096470 A1 discloses a press-hardened sheet metal component with at least one predetermined breaking point. The predetermined breaking point is an over-hardened component area designed to absorb energy by breaking during a crash load. This allows collision energy to be specifically redirected to other components. The press-hardened sheet metal component can be joined to other components in a composite component.

[0003] Furthermore, DE 10 2015 214 149 A1 discloses a method for producing a component assembly comprising at least two components, wherein the components are joined at at least one joint. Furthermore, DE 10 2013 103 719 A1 discloses a supporting structure of a motor vehicle with a flexible beam that is positively secured to a joining partner via a joining element. Furthermore, US 2015 / 0275944 A1 discloses a screw connection consisting of at least one pre-punched upper component and one unpunched lower component, an intermediate layer arranged therebetween, and a plurality of self-drilling fastening screws.

[0004] The object of the present invention is to provide a method for producing a steel component composite and a steel component composite which can be produced particularly easily and particularly quickly.

[0005] This object is achieved according to the invention by a method for producing a steel component composite and by a steel component composite having the features of the independent patent claims. Advantageous embodiments of the invention are the subject of the dependent patent claims and the description.

[0006] To create a method for producing a steel component composite by means of which the steel component composite can be produced particularly easily and particularly quickly, a steel component is provided with a predetermined breaking point and the predetermined breaking point of the steel component is punched into an opening using a press-in element. The press-in element is then pressed into the opening of the steel component and a component is glued to the steel component by means of an adhesive applied over the entire surface, at least in overlap with the press-in element. A flow drilling element is then used to melt a flow hole through the press-in element, the steel component and the component. In other words, the steel component, which is in particular a press-hardened steel component for a motor vehicle, is provided with the predetermined breaking point during a production process for the press-hardened steel component.The press-in element is then brought up to the predetermined breaking point of the steel component in such a way that pressure can be exerted on the predetermined breaking point by means of the press-in element, thereby punching the predetermined breaking point into the opening. By exerting pressure on the press-in element at least on one side perpendicular to a plane of extension of the steel component, the press-in element is pressed into the opening of the steel component, so that the opening is filled in particular with the press-in element. The adhesive is then applied flatly to the steel component and / or the component, in particular in an area of the press-in element, and the steel component is arranged so as to be in contact with the component. The steel component overlaps with the component at least in the area in which the press-in element is arranged.By means of the flow drilling element, which can in particular be a flow hole screw, the flow hole is melted through the press-in element, the steel component and the component under the influence of pressure and / or friction. In particular, the flow hole in the opening is melted through the steel component. For example, the flow drilling element is arranged in the flow hole. The press-in element can prevent the adhesive from contaminating the flow hole due to heat development when melting the flow hole, since the press-in element seals the flow hole when melting the flow hole. Due to the predetermined breaking point of the steel component, the opening can be punched directly into the steel component with the press-in element, so that no additional process step to create the opening in the steel component, such as laser cutting or punching, is necessary before inserting the press-in element.

[0007] In this context, it has proven advantageous to provide the steel component with a predetermined breaking point during hardening. This means that the predetermined breaking point is introduced into the steel component during the hardening process of the press-hardened steel component. During the hardening process, the press-hardened steel is soft and malleable, allowing the predetermined breaking point to be introduced into the steel component with very little effort.

[0008] In an advantageous embodiment of the invention, the flow hole is created during the curing process of the adhesive by means of the flow drilling element. This means that the flow hole is melted through the press-fit element, the steel component, and the component when the adhesive is still in a flowable state after its application. By means of the flow hole, in which, for example, the flow hole screw is arranged, the steel component and the component can be firmly held together, so that the adhesive fixes the steel component and the component in a fixed state by the flow hole and the flow hole screw during curing.

[0009] In a further advantageous embodiment of the invention, an aluminum frame is bonded to the steel component as the component, overlapping the press-fit element. The aluminum frame can be, for example, an aluminum base frame of the motor vehicle. Using this method, the aluminum frame can be attached to the steel component particularly firmly and with particularly precise positioning.

[0010] In an advantageous embodiment of the invention, the predetermined breaking point is created by perforating the steel component. This means that the steel component is provided with holes forming the perforation, which delimit a defined area of the steel component so that this area, which serves as the predetermined breaking point, can be particularly easily punched through by the press-in element. For example, the perforation can be created during the hardening of the steel component. During hardening, the perforation can be created particularly easily in the steel component because the steel component is in a particularly soft state during hardening.

[0011] In an alternative advantageous embodiment of the invention, it is provided that the predetermined breaking point is created by a local material narrowing of the steel component by means of a forming element. For example, the forming element has a bulge which, during a forming process or during a hardening process of the steel component, causes an at least partial material narrowing of the steel component in the defined area. For example, the forming element can be applied to the steel component with pressure, so that the bulge of the forming element displaces material in the defined area to create the local material narrowing. If the local material narrowing is created during a manufacturing process of the press-hardened steel component, a method step for creating the opening can be saved by punching the predetermined breaking point to form the opening at the same time as inserting the press-in element.This can advantageously save time.

[0012] Alternatively, the predetermined breaking point can be created by local overheating during a hardening process of the press-hardened steel component in the defined area.

[0013] A further aspect of the invention relates to a steel component assembly, comprising a steel component having an opening created by a press-in element punching through a predetermined breaking point. Furthermore, the steel component assembly comprises the press-in element, which is pressed into the opening of the steel component. Furthermore, the steel component assembly has a component which is fastened to the steel component by means of adhesive at least in overlap with the opening, wherein the steel component assembly has a flow-drilled opening which extends through the press-in element, the steel component and the component in overlap. Advantageously, individual components of the steel component assembly are particularly firmly connected to one another, since the steel component and the component are connected to one another both by an adhesive connection and by a flow-drilled connection.

[0014] For this purpose, an advantageous development of the invention provides for a flow-drilling screw, by means of which the flow-drilling opening was created, to be arranged in the flow-drilling opening. This means that the flow-drilling screw melts the flow hole in the opening through the press-fit element, the steel component, and the component, and the flow-drilling screw remains arranged in the flow hole. As a result, the steel component and the component, which can be an aluminum base frame of a motor vehicle, are particularly firmly connected to one another. This thus results in a particularly stable steel component composite.

[0015] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own.

[0016] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. They show: Fig. 1 a schematic sectional view of a steel component with a predetermined breaking point; Fig. 2 a schematic sectional view of the steel component according to Fig. 1 with the predetermined breaking point and a press-in element which is arranged at a distance from the steel component; Fig. 3 a schematic sectional view of the steel component according to Fig. 1 with the predetermined breaking point and the press-in element, which rests on the steel component; Fig. 4 a schematic sectional view of the steel component with the press-in element arranged in an opening of the steel component; Fig. 5 a schematic sectional view of the steel component with the press-in element which is pressed into the opening of the steel component; Fig. 6 a schematic sectional view of the steel component with the pressed-in press-in element according to Fig. 5, to which a component is glued by means of an adhesive; Fig. 7 a schematic sectional view of the steel component with the press-in element arranged in the opening, to which the component is glued by means of the adhesive, and a flow-hole screw, wherein a flow hole has been melted through the press-in element by means of the flow-hole screw; Fig. 8 a schematic sectional view of the steel component with the press-in element arranged in the opening and the component bonded by means of the adhesive as well as with the flow hole screw by means of which a flow hole has been melted through the press-in element, the steel component and the component.

[0017] In a summary of the Fig. 1 to 8, a method for producing a steel component composite 1 is shown in a schematic sectional view. In Fig. Figure 1 shows a schematic sectional view of a steel component 2 with a predetermined breaking point 3. The predetermined breaking point 3 is created by a local material narrowing 4 in a defined area of the steel component 2. The steel component 2 is a press-hardened steel component for a motor vehicle. The steel component 2 is provided with the predetermined breaking point 3 during hardening. Alternatively, the predetermined breaking point 3 can be created by perforating the steel component 2.

[0018] In Fig. 2 is a schematic sectional view of how a press-in element 5 is arranged in the area of the predetermined breaking point 3 at a distance from the steel component 2. In a Fig. 3 shows how the press-in element 5 is arranged at the predetermined breaking point 3 on the steel component 2. By applying force, the predetermined breaking point 3 of the steel component 2 is punched into an opening 6 by means of the press-in element 5. As shown in Fig. As shown in Figure 4, the press-in element 5 is arranged in the opening 6 of the steel component 2 after the predetermined breaking point 3 of the steel component 2 has been punched through. By further applying a force to the press-in element 5, the press-in element 5 is, as shown in Fig. 5 is shown in a schematic sectional view, is pressed into the opening 6 of the steel component 2, so that the press-in element 5 completely fills the opening 6.

[0019] After the press-in element 5 has been pressed into the opening 6 of the steel component 2, a component 7 is bonded to the steel component 2 by means of a surface-applied adhesive 8, at least overlapping the press-in element 5. In this case, the component 7 is an aluminum base frame of the motor vehicle. The adhesive 8 can be applied surface-wide to the component 7 and / or to the steel component 2. During a curing process of the adhesive 8, a flow hole 9 is melted through the press-in element 5, the steel component 2, and the component 7 by means of a flow drilling element, in this case a flow hole screw 10. Melting occurs due to friction and a resulting temperature increase in the area around the flow hole screw 10.

[0020] As in Fig. As shown in Figure 7, the flow hole screw 10 is applied to the press-in element 5 to create the flow hole 9 and is first moved through it. The flow hole 9 is then melted through the adhesive 8 and the component 7. As shown in Fig. As can be seen in a schematic sectional view in Figure 8, the press-in element 5 melts due to heat development during the creation of the flow hole 9 and thereby changes its shape. Fig. Figure 8 illustrates how the press-in element 5 melts into a layer formed by the adhesive 8, thus shielding or sealing the adhesive 8 from the flow-hole screw 10. After the flow hole 9 has been created, the flow-hole screw 10 can remain arranged in the flow hole 9 or can be removed from the flow hole 9 after the adhesive 8 has hardened and the press-in element 5 has melted due to the heat development.

[0021] In connection with the Fig. 1 to 8 are based on the finding that it is currently not possible to join press-hardened steel components using the flow-hole screw 10 and an intermediate adhesive layer without the adhesive 8 contaminating the area around the flow hole 9 on the press-hardened steel component 2 or on the component 7 due to the heat development near the flow-hole screw 10. This is remedied with the press-in element 5 by sealing this area. The press-in element 5 is intended to have relatively low strength compared to the press-hardened steel component 2, which means that inserting the press-in element 5 into the steel component 2 without a through hole is currently not possible. The problem is that the press-in element 5 is softer than the steel component 2, but is intended to pierce it.Since piercing or punching through the steel component 2 by means of the press-in element 5, which is softer than the steel component 2, is currently not possible without a through hole, an additional process step is required, which is associated with additional costs.

[0022] To avoid this additional process step, the steel component composite 1, as described in connection with the Fig.1 to 8. Similar to the closure of a beverage can or a SIM card, the predetermined breaking point 3 in the form of the opening 6 to be created later is to be introduced during the manufacturing process of the steel component 2. This predetermined breaking point 3 is created as a trench-shaped depression in the steel component 2 by a contour on one tool half, which presses into a material of the steel component 2 during the manufacturing process of the press-hardened steel component 2. This pressing in requires only a small amount of force, since the steel component 2 is almost doughy due to heating during the manufacturing process. This does not produce any chips or waste that would have to be removed. Advantageously, the additional process step, which would involve, for example, laser cutting or punching before inserting the press-in element 5, can thus be omitted. List of reference symbols 1 steel component composite 2 steel component 3 Predetermined breaking point 4 Material narrowing 5 Press-in element 6 Opening 7 Component 8 Adhesive 9 Flow hole 10 flow hole screw

Claims

[1] Method for producing a steel component composite (1), in which - a steel component (2) is provided with a predetermined breaking point (3), - the predetermined breaking point (3) of the steel component (2) is punched through to form an opening (6) by means of a press-in element (5), - the press-in element (5) is pressed into the opening (6) of the steel component (2), - a component (7) is bonded to the steel component (2) by means of a surface-applied adhesive (8), at least in overlap with the press-in element (5), and - by means of a flow drilling element - a flow hole (9) is melted through the press-in element (5) and the component (7), which flow hole extends through the press-in element (5), the steel component (2) and the component (7) in overlap. [2] Method according to claim 1, characterized by that the steel component (2) is provided with the predetermined breaking point (3) during hardening. [3] Method according to claim 1 or 2, characterized by that the flow hole (9) is created by means of the flow drilling element during a curing process of the adhesive (8). [4] Method according to one of the preceding claims, characterized by that as the component (7) an aluminum frame is glued to the steel component (2) in overlap with the press-in element (5). [5] Method according to one of the preceding claims, characterized by that the predetermined breaking point (3) is created by introducing a perforation into the steel component (2). [6] Method according to one of claims 1 to 4, characterized by that the predetermined breaking point (3) is created by a local material narrowing (4) of the steel component (2) by means of a shaped element. [7] Steel component composite (1), with a steel component (2) which has an opening (6) created by a press-in element (5) by punching through a predetermined breaking point (3), with the press-in element (5) which is pressed into the opening (6) of the steel component (2), with a component (7) which is fastened to the steel component (2) by means of adhesive (8) at least in overlap with the press-in element (5), wherein the steel component composite (1) has a flow hole (9) which extends through the press-in element (5), the steel component (2) and the component (7) in overlap. [8] Steel component composite (1) according to claim 7, characterized by that a flow hole screw is arranged in the flow hole (9), by means of which the flow hole (9) has been created.

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