Method for manufacturing a plastic underride protection element with sheet metal elements, underride protection element, battery storage arrangement and motor vehicle with such an underride protection element

Abstract

A method (500) for manufacturing an underride protection element (10) is described, comprising the steps: providing (S501) at least one sheet metal element (20); coating (S502) both sides of the at least one sheet metal element (20) with an adhesion promoter (20h), in particular an adhesion promoter film; providing (S503) at least two cover layers (16a, 16b) made of a second fiber-reinforced thermoplastic material, in particular UD tapes or organosheet; positioning (S504) the at least one sheet metal element (20) coated with adhesion promoter (20h) on a top side (16s) of a lower cover layer (16b); covering (S505) the at least one sheet metal element (20) coated with adhesion promoter (20h) with an upper cover layer (16a);Temporarily fastening (S506) the at least one sheet metal element (20) that is located between the lower cover layer (16b) and the upper cover layer (16a), in particular by applying pressure and / or increasing the temperature; providing (S507) the temporary composite consisting of the lower cover layer (16b), the upper cover layer (16a) and the at least one sheet metal element (20) as a cover layer semi-finished product (17). Furthermore, an underride protection element (10), a battery storage arrangement and a motor vehicle are described.

Description

The invention relates to a method for manufacturing an underride protection element with a core element made of a first thermoplastic polymer material for a battery storage arrangement of a motor vehicle. The invention further relates to an underride protection element manufactured in particular according to the method, a battery arrangement with such an underride protection element, and a motor vehicle with such a battery arrangement. From DE 20 2022 106 714 U1, a lower protective plate with a metal wire unit and a unit made of non-metallic material for a battery pack is known. Furthermore, from DE 10 2022 118 581 B3, a sandwich structure is known in which metallic hollow profiles are surrounded by a textile material or by plastic. The object underlying the invention is seen as being to provide a method for manufacturing an underride protection element made of plastic, in which improved stability and improved fire protection are achieved. This problem is solved by a method and an underride protection element with the features of the respective independent patent claim. Advantageous embodiments with expedient further developments are specified in the dependent patent claims. A method for manufacturing an underride protection element with a core element made of a first thermoplastic material for a battery storage arrangement of a motor vehicle is proposed, comprising the steps of: providing at least one sheet metal element; coating both sides of the at least one sheet metal element with an adhesion promoter, in particular an adhesion promoter film; providing at least two cover layers made of a second fiber-reinforced thermoplastic material, in particular UD tapes or organosheets; positioning the at least one sheet metal element coated with adhesion promoter on a top surface of a lower cover layer; covering the at least one sheet metal element coated with adhesion promoter with an upper cover layer;Temporarily fastening the at least one sheet metal element that is sandwiched between the lower and upper cover layers, in particular by applying pressure and / or increasing the temperature; providing the temporary composite of the lower, upper, and at least one sheet metal element as a cover layer semi-finished product. By inserting one or more sheet metal elements between the lower and upper cover layers, the finished underride protection element can exhibit improved properties in terms of mechanical stability and fire protection in the areas with sheet metal elements. In this process, at least one sheet metal element can be cut to a desired sheet metal element length before or after coating with the adhesion promoter. Regarding the provision of the sheet metal element, it should be noted that it can be made of aluminum or steel. Furthermore, coating with an adhesion promoter film can be carried out, for example, in a roll-to-roll process, whereby the sheet metal element is cut to length after the adhesion promoter film has been laminated onto it. Alternatively, the sheet metal element can first be cut to length, and then the adhesion promoter can be applied to its front and back surfaces, in particular an adhesion promoter film can be applied. It is also conceivable that the adhesion promoter is applied in powder form. Furthermore, it is also conceivable that a liquid or powdered adhesion promoter is sprayed onto the sheet metal element. In this process, the at least one sheet metal element can be completely covered by the lower and upper cover layers, wherein the at least one sheet metal element, and in particular all sheet metal elements arranged in the cover layer semi-finished product, have a distance of 5 cm or more from the nearest edge of the cover layers. This ensures that the sheet metal elements do not protrude or become visible from the outside during subsequent forming. In this case, the cover layer semi-finished product can have a greater thickness in the area of ​​at least one sheet metal element with respect to a cross-section than in an area where the lower cover layer and the upper cover layer lie directly on top of each other. In this process, the cover layer semi-finished product can be moved into a preheating station using vacuum grippers, with the vacuum grippers being positioned particularly in the area of ​​the at least one sheet metal element. This allows the cover layer semi-finished product to be transported safely, and the mechanical stability of the cover layer semi-finished product is particularly advantageous when the vacuum grippers are positioned in the area of ​​the sheet metal element(s). In this process, the surface layer semi-finished product can be heated above the melting temperature of the second thermoplastic material and removed from the preheating station after heating. This heating process ensures homogeneous heating of the surface layer layers and the sheet metal element, so that the surface layer semi-finished product is optimally prepared for further processing. The following can be provided for the further manufacture of the underride protection element in the process: a first heated cover layer semi-finished product as the lower cover layer; a second heated cover layer semi-finished product as the upper cover layer; wherein the first thermoplastic polymer material is applied to the lower cover layer at least section by section, in particular in the form of at least one LFT-D strand; and wherein the upper cover layer is arranged on the first thermoplastic polymer material so that it is contained between the lower cover layer and the upper cover layer; wherein an unshaped stack formed from the lower cover layer, the first thermoplastic polymer material and the upper cover layer is picked up by means of needle grippers of a transport device and arranged in a cavity of a molding tool. The needle grippers can pass through the entire stack and be arranged in such a way that the needle grippers secure the at least one sheet metal element in the lower cover layer and in the upper cover layer against slipping, wherein in particular at least one needle gripper is arranged on two sides of the at least one sheet metal element, wherein the respective needle gripper is arranged at a distance of 2mm to 10mm, in particular 5mm, from a longitudinal edge of the sheet metal element. In this process, the stacks are formed into the finished underride protection element within the mold and then removed from it. The forming of the stack typically takes place with the mold halves closed, under increased pressure and at temperatures that result in a material-bonded connection between the surface layers and the first thermoplastic material of the core element. During the forming process, it is also possible that, for example, rib-like support elements made of the first thermoplastic material are produced on one of the cover layers, especially on the upper cover layer. Also proposed is an underride protection element for a battery storage arrangement of an at least partially electrically powered motor vehicle, comprising a planar core element made of a first thermoplastic material; at least one lower and at least one upper cover layer made of a second fiber-reinforced thermoplastic material; several rib-like support elements projecting from a top cover layer for supporting the underride protection element on the battery storage arrangement; wherein at least one metal sheet element is arranged between the upper cover layer and the core element and / or between the lower cover layer and the core element, the sheet element being aligned along an adjacent support element, and wherein the underride protection element is manufactured in particular by the method according to one of the preceding claims. A battery arrangement for a motor vehicle that is at least partially electrically powered may include such an underride protection element. Furthermore, a motor vehicle with at least a partially electric drive can be equipped with such a battery arrangement or with such an underride protection element. Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures. Figure 1 shows a simplified and schematic representation of some steps of a method for manufacturing an underride protection element; Figure 2 shows a simplified and schematic representation of further steps of the method for manufacturing the underride protection element; Figure 3 shows a simplified and schematic representation of further steps of the method for manufacturing the underride protection element; Figure 4 shows a simplified and schematic top view of an underride protection element; Figure 5 shows a simplified and schematic sectional view of a battery arrangement with an underride protection element approximately corresponding to a section line VV of Figure 4. In Fig. 1, Fig. 2 to Fig. 3 a simplified and schematic method 500 for the production of an underride protection element 10 shown in Fig. 4 and Fig. 5 with a core element 14 made of a first thermoplastic plastic material for a battery storage arrangement 12 of a motor vehicle 200 is shown. In method 500, according to step S501, at least one sheet metal element 20 is provided. In the example shown, several, in particular four, sheet metal elements 20 are provided, which, however, is not to be understood as restrictive. According to step S502, at least one of the sheet metal elements 20 is coated on both sides with an adhesion promoter 20h, as illustrated by the pattern with inclined lines. The applied adhesion promoter 20h can be an adhesion promoter film. According to step S503, at least two cover layers 16a, 16b are provided from a second fiber-reinforced thermoplastic material, in particular UD tapes or organosheets. According to step S504 ( Fig. 2 ) the sheet metal elements 20 coated with adhesion promoter 20h are positioned on a top surface 16s of a lower cover layer 16b. According to step S505, the sheet metal elements 20 coated with adhesion promoter 20h are covered with an upper cover layer 16a. According to step S506, the sheet metal elements 20, which are sandwiched between the lower cover layer 16b and the upper cover layer 16a, are temporarily fastened, in particular by applying pressure and / or increasing the temperature. Temporary fastening can be achieved, for example, by passing the cover layers 16a, 16b with the sheet metal elements 20 arranged between them through a double belt press over their entire surface. Alternatively, it is conceivable that welded joints are produced locally in the area of ​​the sheet metal elements 20, in particular using an ultrasonic sonotrode. According to step S507, the temporary composite consisting of the lower cover layer 16b, the upper cover layer 16a and the at least one sheet metal element 20 is provided as cover layer semi-finished product 17. In method 500, at least one sheet metal element 20 can be cut to a desired sheet metal element length BL before or after coating with the adhesion promoter 20h, as illustrated in Fig. 1 by step S508. In method 500, the sheet metal elements 20 are positioned in particular (step S504) such that, after performing step S505, they are completely covered by the lower cover layer 16b and the upper cover layer 16a, wherein the sheet metal elements 20 have a distance AB of 5cm or more to the nearest edge 16r of the cover layers 16a, 16b. In method 500, the cover layer semi-finished product 17 can have a greater thickness in the area of ​​the at least one sheet element 20 with reference to a cross-section not shown here than in an area where the lower cover layer 16b and the upper cover layer 16a lie directly on top of each other. In method 500, according to step S509, the cover layer semi-finished product can be moved into a preheating station 52, which is only schematically indicated, by means of vacuum grippers 50, which are simplified to represent a circle with a cross, wherein the vacuum grippers 50 are positioned in particular in the area of ​​the at least one sheet metal element 20. The cover layer semi-finished product 17 can be heated in the preheating station 52 above the melting temperature of the second thermoplastic material and removed from the preheating station after heating. The method 500 can include the following further steps for the further manufacture of the underride protection element 10, which are shown in Fig. 3. According to step S510, a first heated cover layer semi-finished product 17 can be provided as the lower cover layer 17u. According to step S511, a second heated cover layer semi-finished product 17 can be provided as the upper cover layer 17t. According to step S512, the first thermoplastic polymer material 14m can be applied to the lower cover layer 17u at least section by section, in particular in the form of at least one LFT-D strand. According to step S513, the upper cover layer 17t can be arranged on the first thermoplastic material 14m, so that it is sandwiched between the lower cover layer 17u and the upper cover layer 17t. According to step S514, an unshaped stack 19 formed from the lower cover layer 17u, the first thermoplastic plastic material 14m and the upper cover layer 17t can be picked up by means of needle grippers 54 of a transport device and arranged in a cavity of a molding tool 56. The needle grippers 54 can extend through the entire stack 19 and be arranged such that they secure the sheet metal elements 20 against slippage in the lower cover layer 17u and the upper cover layer 17t. In particular, the needle grippers 54 can be arranged on both sides of each sheet metal element 20, with each needle gripper 54 positioned at a distance of 2 mm to 10 mm, particularly 5 mm, from a longitudinal edge 20r of the sheet metal element 20. In process 500, according to step S515, the stack 19 can be formed in the forming tool 56 to form the finished underride protection element 10 and then removed from the forming tool 56 (S516). An underride protection element 10, produced in particular according to the method 500 described above, is described below with reference to Fig. 4 and Fig. 5. Figure 4 shows a simplified, schematic top view of an underride protection element 10. Figure 5 shows a simplified sectional view through the underride protection element 10, approximately along section line VV, and a battery storage arrangement 12. Figure 5 also illustrates a motor vehicle 200, depicted as a dashed rectangle, in which such a battery arrangement 12 with the underride protection element 10 can be arranged. The motor vehicle 200 can be at least partially electrically powered; in particular, it can be a fully electric vehicle or a hybrid vehicle. The underride protection element 10 has a planar core element 14 made of the first thermoplastic material. Furthermore, the underride protection element 10 comprises a lower and an upper cover layer 17u, 17t, which were provided as cover layer semi-finished products 17 according to the method 500 described above. Figure 5 illustrates, purely by way of example, two cover layer layers 16a, 16b for each cover layer 17u, 17t. However, this is not a mandatory requirement. Rather, more than two cover layer layers 16a, 16b may also be provided. The underride protection element 10 has several rib-like support elements 18 projecting from the uppermost cover layer 16a of the upper cover layer 17t for supporting the underride protection element 10 on the battery storage arrangement 12. Fig. 5 shows in particular that the sheet metal elements 20 are each arranged between an upper cover layer 16a and a lower cover layer 16b of the respective upper or lower cover layer 17t, 17u. From the combined view of Figs. 4 and 5, it is further evident that the sheet metal elements 20 are completely surrounded by the second plastic material, in particular by the cover layers 16a, 16b. In other words, the sheet metal elements 20 are completely surrounded by or integrated into the fiber-reinforced plastic material. The sheet metal elements 20 can be made of aluminum or steel. It should be noted that sheet metal elements 20 are shown in both the upper cover layer 17t and the lower cover layer 17u in Fig. 5. However, it is not essential that such sheet metal elements 20 are present in the lower cover layer 17u. In particular, it is conceivable that in the lower cover layer 17u the sheet metal elements 20 are arranged, for example, only in a central area of ​​the underride guard element 10 in order to improve mechanical stability in that area. Figure 5 shows that the battery arrangement 12 comprises several battery storage modules 22, each containing several battery cells (not explicitly shown). The battery storage modules 22 are housed in a battery box 24. The underride protection element 10 is arranged on the underside of the battery box 24, and is supported on the battery box 24, in particular by means of the support elements 18. In particular, the sheet metal elements 20 in the upper cover layer 17t are each arranged opposite a respective battery storage module 22. Specifically, each sheet metal element 20 is arranged opposite degassing openings 26 of the battery cells of the battery storage module 22. The sheet metal elements 20 extend along the support elements 18. In particular, the sheet metal elements 20 and the support elements 18 are essentially parallel to each other. The sheet metal elements 20 improve the stability of the underride guard element 10 and provide enhanced fire protection in the event that hot gas escapes downwards from a degassing opening 26 towards the underride guard element 10, especially the upper cover layer 17t. With regard to the arrangement of such a battery storage assembly 12 with underride protection element 10 in the motor vehicle 200, it should be noted that the underride protection element 10 has a circumferential edge section 14r (Fig. 4) which is formed integrally with the core element 14. The edge section 14r can be at least partially connected to body supports of the motor vehicle 200 (not shown). QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature DE 20 2022 106 714 U1

[0002] DE 10 2022 118 581 B3

[0002]

Claims

Method (500) for manufacturing an underride protection element (10) with a core element (14) made of a first thermoplastic material (14m) for a battery storage arrangement (12) of a motor vehicle (200), comprising the steps: providing (S501) at least one sheet metal element (20); coating (S502) both sides of the at least one sheet metal element (20) with an adhesion promoter (20h), in particular an adhesion promoter film; providing (S503) at least two cover layers (16a, 16b) made of a second fiber-reinforced thermoplastic material, in particular UD tapes or organosheet; positioning (S504) the at least one sheet metal element (20) coated with adhesion promoter (20h) on a top side (16s) of a lower cover layer (16b); covering (S505) the at least one sheet metal element (20) coated with adhesion promoter (20h) with an upper cover layer (16a);Temporarily fastening (S506) the at least one sheet metal element (20) that is received between the lower cover layer (16b) and the upper cover layer (16a), in particular by applying pressure and / or increasing the temperature; providing (S507) the temporary composite of the lower cover layer (16b), the upper cover layer (16a) and the at least one sheet metal element (20) as a cover layer semi-finished product (17). Method (500) according to claim 1, wherein the at least one sheet metal element (20) is cut to a desired sheet metal element length (BL) before or after coating with the adhesion promoter (20h) (S508). Method (500) according to claim 1 or 2, wherein the at least one sheet metal element (20) is completely covered by the lower cover layer (16b) and the upper cover layer (16a), wherein the at least one sheet metal element (20), in particular all sheet metal elements (20) arranged in the cover layer semi-finished product (17), have a distance (AB) of 5cm or more to a nearest edge (20r) of the cover layers (16a, 16b). Method (500) according to one of the preceding claims, wherein the cover layer semi-finished product (17) has a greater thickness with respect to a cross-section in the area of ​​the at least one sheet element (20) than in an area where the lower cover layer (16b) and the upper cover layer (16a) lie on top of each other. Method (500) according to one of the preceding claims, wherein the cover layer semi-finished product (17) is moved into a preheating station (52) by means of vacuum grippers (50) (S509), wherein the vacuum grippers (50) are positioned in particular in the area of ​​the at least one sheet metal element (20). Method (500) according to claim 5, wherein the cover layer semi-finished product (17) is heated above the melting temperature of the second thermoplastic polymer and is removed from the preheating station (52) after heating. Method (500) according to claim 6, wherein the following are provided for the further manufacture of the underride protection element (10): a first heated cover layer semi-finished product (17) as lower cover layer (17u) (S510); a second heated cover layer semi-finished product (17) as upper cover layer (17t) (S511); wherein the first thermoplastic polymer material (14m) is applied at least sectionally to the lower cover layer (17u) (S512), in particular in the form of at least one LFT-D strand; and wherein the upper cover layer (17t) is arranged on the first thermoplastic material (14m) (S513), so that the latter is held between the lower cover layer (17u) and the upper cover layer (17t); wherein an unshaped stack (19) formed from the lower cover layer (17u), the first thermoplastic material (14m) and the upper cover layer (17t) is picked up by means of needle grippers (54) of a transport device and is arranged in a cavity of a molding tool (56) (S514). Method (500) according to claim 7, wherein the needle grippers (54) extend through the entire stack (19) and are arranged such that the needle grippers (54) secure the at least one sheet metal element (20) in the lower cover layer (17u) and in the upper cover layer (17t) against slipping, wherein in particular at least one needle gripper (54) is arranged on two sides of the at least one sheet metal element (20), wherein the respective needle gripper (54) is arranged at a distance of 2mm to 10mm, in particular 5mm, from a longitudinal edge (20r) of the sheet metal element (20). Method (500) according to claim 7 or 8, wherein the stack (19) is formed in the forming tool (56) to form the finished underride protection element (10) (S515) and is subsequently removed from the forming tool (56) (S516). Underride protection element (10) for a battery storage arrangement (12) of an at least partially electrically powered motor vehicle (200), comprising a planar core element (14) made of a first thermoplastic material (14m); at least one lower and at least one upper cover layer (17u, 17t) made of a second fiber-reinforced thermoplastic material; several rib-like support elements (18) projecting from an uppermost cover layer (16a) for supporting the underride protection element (10) on the battery storage arrangement (12); wherein at least one metal sheet element (20) is arranged between the upper cover layer (17t) and the core element (14) and / or between the lower cover layer (17u) and the core element (14), which is aligned along an adjacent support element (18), wherein the underride protection element is manufactured in particular by the method (500) according to one of the preceding claims.

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