DE102021118286B4 - Underbody protection element made of duroplastic material, manufacturing method and motor vehicle with an underbody protection element - Google Patents

Abstract

An underbody protection element (10) for a motor vehicle (200), in particular an electric vehicle, is described, having a formed core element (12) made from a duroplastic fiber matrix semi-finished product, in particular from a sheet or plate-like molding compound (SMC) and/or from a shapeless compound ( BMC), at least one reinforcement element (14c, 14d) made of a glass fiber reinforced duroplastic material, in particular a duroplastic prepreg, wherein the at least one reinforcement element (14c, 14d) is materially connected to the core element (12). It is provided that the underbody protection element (10) has a shaped, peripheral edge section (16) made of a duroplastic fiber matrix semi-finished product, the at least one reinforcement element (14c, 14d) being arranged within the area delimited by the edge section (16). . A production method for such an underbody protection element (10) and a motor vehicle with such an underbody protection element (10) are also described.

Description

The invention relates to an underbody protection element for a motor vehicle, in particular an electric vehicle, with a formed core element made from a duroplastic fiber matrix semi-finished product, in particular from sheet-like or plate-like molding compound (SMC) and/or from shapeless compound (BMC), at least one reinforcing element made from a Glass fiber reinforced duroplastic material, in particular a duroplastic prepreg, wherein the at least one reinforcement element is materially connected to the core element. Furthermore, the invention relates to a method for producing such an underbody protection element.

From the prior art, for example, an energy storage housing assembly from DE 10 2019 206 646 A1 known. An underrun protection is for example in the DE 10 2019 131 625 A1 disclosed. From the pamphlets DE 10 2019 135 323 A1 and WO 2016 201 279 A1 are known underbody protection elements made of thermoplastic materials. Furthermore, a contribution by Dr. Ralf Hoppe from 2014 with the title "The Future of Carbon Fiber Composites", which was published on www.plastverarbeiter.de.

The object on which the invention is based is seen in specifying an underbody protection element that is as light as possible but at the same time rigid, and a corresponding manufacturing method.

This object is achieved by an underbody protection element, a method for its production and a motor vehicle with the features of the respective independent patent claims. Advantageous configurations with expedient developments are specified in the dependent patent claims.

An underbody protection element for a motor vehicle, in particular an electric vehicle, is therefore proposed
a formed core element made of a duroplastic fiber matrix semi-finished product, in particular made of sheet or plate-like molding compound (SMC or Sheet Molding Compound) and/or of shapeless compound (BMC or Bulk Molding Compound),
at least one reinforcement element made of a glass fiber reinforced duroplastic material, in particular a duroplastic prepreg, wherein the at least one reinforcement element is materially connected to the core element.
It is provided that the underbody protection element has a shaped, peripheral edge section made of the duroplastic fiber matrix semi-finished product, with the at least one reinforcement element being arranged within the area delimited by the edge section.

As a result, the edge area of the underbody protection element can be configured variably, with the core element and the reinforcing element being able to be connected to the edge area in a materially bonded manner, without them themselves being or being reshaped in the edge area.

The underbody protection element has a plurality of rib-like support sections made of the duroplastic fiber matrix semi-finished product, which protrude beyond the at least one reinforcement element on at least one side of the underbody protection element. The rib-like support sections can protrude in the direction of the motor vehicle in relation to a mounted state of the underbody protection element on the motor vehicle. The support sections can be made in particular from a shapeless compound or BMC. As a result, reinforcements can be provided on the underbody protection element in a variable manner and optimized for a particular vehicle type. The rib-like elements referred to here as support sections also serve to reinforce the underbody protection element. In this respect, they can also be understood or referred to as rib-like stiffening sections.

The underbody protection element can have at least one heat protection element, which is materially connected to the core element and/or to the reinforcement element. Such a heat protection element can be made, for example, from a material with a ceramic content. Foil-like heat protection elements that are arranged and connected at corresponding points of the underbody protection element are also conceivable. In this way, in particular, a locally optimized heat dissipation can be made possible.

The underbody protection element can have at least one stiffening element which is materially connected to the core material and/or to the reinforcing element. An additional carbon fiber UD tape, for example, can be used as a stiffening element. As a result, the underbody protection element can be reinforced or stiffened locally in an optimized manner.

The underbody protection element can have a plurality of reinforcement elements which are designed in the manner of strips and are arranged at a distance from one another.

In this connection, a rib-like support section can be formed between two adjacent strip-like reinforcement elements be that Here, the underbody protection element, based on a mounted state on the motor vehicle, can have several strip-like reinforcement elements on its upper side facing the motor vehicle and on its lower side facing away from the motor vehicle.

The underbody protection element has a plurality of contact sections, at which the underbody protection element can be connected to a body of the motor vehicle. The contact sections can also be referred to as load introduction elements. The contact sections or load introduction elements can usually have a fastening opening formed by a sleeve, through which a screw shank is guided and connected to the body.

In the case of the underbody protection element, the contact sections can be distributed in the edge section. In particular, the contact sections can be arranged adjacent to one another along the circumference of the underbody protection element but with a respective spacing between two contact sections.

The underbody protection element has a plurality of support sections running in a longitudinal direction and a plurality of support sections running in a transverse direction of the underbody protection element, with contact sections being arranged in crossing regions of the support sections. As a result, the underbody protection element can be connected to the body at crossing points of support sections that are designed to be particularly stable or stiff.

1. a) Anordnen von wenigstens einem Kernmaterialvolumen aus einem duroplastischen Faser-Matrix-Halbzeug, insbesondere aus blatt- oder plattenartiger Formmasse (SMC) oder/und aus formloser Masse (BMC) auf einer Verarbeitungsplattform;
2. b) Umformen des wenigstens einen Kernmaterialvolumens, so dass das wenigstens eine Kernmaterialvolumen zum einstückigen Kernelement mit rippenartigen Abstützabschnitt und mit umlaufendem Randabschnitt umgeformt wird;
3. c) Anordnen von wenigstens einem Verstärkungselement aus einem glasfaserverstärkten duroplastischen Material, insbesondere einem duroplastischen Prepreg, oder von einem Materialvolumen für ein Verstärkungselement, insbesondere einer aufgespritzten Materialmischung aus geschnittenen Glasfasern und einem Kunststoff, an oder auf dem umgeformten Kernelement;
4. d) materialschlüssiges Verbinden des wenigstens einen Verstärkungselements mit dem Kernelement oder Nasspressen des wenigstens einen Verstärkungselements zur materialschlüssigen Verbindung mit dem Kernelement.

A method for producing an underbody protection element (without cover layers) comprises the steps:

1. a) Arranging at least one core material volume made of a duroplastic fiber matrix semi-finished product, in particular made of sheet or plate-like molding compound (SMC) and/or of shapeless compound (BMC) on a processing platform;
2. b) reshaping of the at least one volume of core material, so that the at least one volume of core material is reshaped to form the one-piece core element with a rib-like support section and with a peripheral edge section;
3. c) arranging at least one reinforcement element made of a glass fiber reinforced duroplastic material, in particular a duroplastic prepreg, or of a material volume for a reinforcement element, in particular a sprayed-on material mixture of cut glass fibers and a plastic, on or on the formed core element;
4. d) Material-locking connection of the at least one reinforcement element to the core element or wet pressing of the at least one reinforcement element for material-locking connection to the core element.

The arrangement of a material volume for a reinforcement element, in particular a sprayed-on material mixture of cut glass fibers and a plastic, can take place in particular according to the principle or method of long fiber injection (Long Fiber Injection LFI).

In step c) of the method, the at least one reinforcement element can be arranged between two rib-like support sections.

In the method, the duroplastic materials can be formed in a forming tool at a temperature of about 120°C. up to 165°C. be performed.

A motor vehicle, in particular an electrically powered motor vehicle, can be designed with an underbody protection element as described above.

• 1 in den Teilfiguren A) bis E) ein Beispiel eines Unterbodenschutzelements in einer vereinfachten und schematischen Draufsicht und in verschiedenen Schnittdarstellungen;
• 2 ein Verfahren zur Herstellung von einem Unterbodenschutzelement, das in 1 gezeigt ist;
• 3 eine schematische und vereinfachte Darstellung eines Kraftfahrzeugs mit einem Unterbodenschutzelement gemäß 1.

Further advantages and details of the invention result from the following description of embodiments with reference to the figures. It shows:

• 1 in sub-figures A) to E) an example of an underbody protection element in a simplified and schematic plan view and in various sectional views;
• 2 a method for the production of an underbody protection element, which in 1 is shown;
• 3 a schematic and simplified representation of a motor vehicle with an underbody protection element according to FIG 1 .

1 shows an underbody protection element 10 in a schematic and simplified representation 1 1 shows the underbody protection element 10 for a motor vehicle 200, which is only indicated here as a dashed rectangle, in particular a (partially) electrically driven motor vehicle, shown in a simplified and schematic manner in a type of plan view. The underbody protection element 10 is described below with simultaneous reference to the plan view of FIG 1A and the sectional views of the 1B until 1E described, with the cuts in the 1B until 1 E about the intersection line BB the 1A correspond, even if only the 1 B the embodiment of the 1A shows on average.

The underbody protection element 10 of 1 has a formed core element 12 made of a duroplastic fiber matrix semi-finished product, in particular made of sheet-like or plate-like molding compound (SMC) and/or of shapeless compound (BMC). However, the core element 12 is not held between cover layers, but rather has a plurality of reinforcement elements 14c made of a glass fiber-reinforced duroplastic material, in particular a duroplastic prepreg. The reinforcement elements 14c are materially connected to the core element 12 .

A shaped, peripheral edge section 16 is provided in the underbody protection element 10 , with the reinforcement elements 14c being arranged within the area delimited by the edge section 16 . With regard to the edge section 16, it is pointed out that this can be made of the same material as the core element 12. In other words, the core element 12 and the edge section 16 can form a formed unit.

From the 1 It can also be seen that the underbody protection element 10 has a plurality of rib-like support sections 18 made of a duroplastic fiber matrix semi-finished product, which protrude beyond the reinforcing element 14c at least on one side of the underbody protection element 10 . The rib-like support sections 18 can protrude in the direction of the motor vehicle (upwards) in relation to a mounted state of the underbody protection element 10 on the motor vehicle 200 .

Optionally, the underbody protection element 10 can have at least one heat protection element 20 which is materially connected to the core element 12 and/or to the reinforcement element 14c.

The underbody protection element 10 can have at least one reinforcement element 22 which is materially connected to the core material 12 and/or to at least one reinforcement element 14c.

The underbody protection element 10 comprises a plurality of rib-like support sections 18. The support sections 18 are connected to the core element 12. The reinforcement elements 14c are accommodated or arranged in a web-like manner between respectively adjacent support sections 18 .

Regarding the sectional view of the 2C it is pointed out that reinforcement elements 14d are shown there by way of example, which are connected to the core element 12 on a lower side of the underbody protection element 10 .

According to the example of 2D Reinforcement element 14c, 14d can be provided on the upper side and the underside of the underbody protection element 10.

Furthermore shows 2E an example in which a reinforcing member 14d continuous in the transverse direction QR is connected to the core member 12. With such an embodiment of the reinforcement element 14d, a surface located inside the circumferential edge section 16 is essentially completely covered with the reinforcement element 14d.

The underbody protection element 10 can also be designed in such a way that several reinforcement elements 14c, as in 2 B provided, and on the underside a (continuous) reinforcing element 14d like 2E provided, are arranged.

The underbody protection element 10 of 1 has a plurality of contact portions 24 on which the underbody protection element 10 with a in the 1 not shown body of the motor vehicle 200 is connected. The contact sections 24 are distributed in particular in the edge section 16, not all possible contact sections 24 being shown. It is also conceivable that contact sections 24 can be arranged in the support sections 18 .

It is pointed out that a plurality of support sections 18 can be arranged in a longitudinal direction LR and in a transverse direction QR of the underbody protection element. this is in 1 illustrated only by a further support section running in the transverse direction QR. This results in crossing areas 26 of the stiffening sections 18 running longitudinally or transversely, it being possible for contact sections 24 to be arranged in crossing areas 26 of the support sections 18 .

From the 1 Thus, an underbody protection element 10 can be seen which is made from a combination of the following materials: reinforcement elements 14c or 14d made from a duroplastic prepreg. A core layer or a core element 12 made from an SMC semi-finished product or from a BMC molding compound. Support sections 18 and edge sections 16 made of a BMC molding compound. Regarding making a related to the 1 The underbody protection member 10 described above will be referred to later description of a manufacturing method with reference to FIG 2 referred.

2 shows simplified possible method steps of a method 600 for producing a 1 shown underbody protection element 10. Such a manufacturing method 600 includes the steps listed below.

According to a step S601, at least one core material volume made from a duroplastic fiber matrix semi-finished product, in particular from sheet-like or plate-like molding compound (SMC) and/or formless compound (BMC) is arranged on a processing platform. A processing platform can already be part of a mold or a kind of preparation table. According to step S602, the at least one volume of core material is reshaped, so that the at least one volume of core material is reshaped to form the one-piece core element 12 with rib-like support sections 18 and with a peripheral edge section 16. Subsequently, according to step S603, at least one reinforcement element 14c or 14d made of a glass fiber-reinforced duroplastic material, in particular a duroplastic prepreg, or a material volume for a reinforcement element 14c or 14d, in particular a sprayed-on material mixture of cut glass fibers and a plastic, on or on the formed core element 12. According to step S604, the at least one reinforcement element 14c or 14d and the formed core element 12 are materially connected to one another or the at least one is wet-pressed Reinforcement element 14c, 14d for the material connection with the core element 12.

In method 600, in step S603, the at least one reinforcement element 14c or 14d can be arranged between two rib-like support sections 18.

But it is also conceivable how this 2E it is shown by way of example that the reinforcement element 14d is designed essentially over the entire surface, in particular if it is provided on the underside of the underbody protection element 10, from which no rib-like support sections 18 protrude or on which no such support sections 18 are provided or formed.

In method 600, the thermoset materials are formed (step S602) in a forming tool at a temperature of about 120°C. up to 165°C. carried out.

Finally, on 3 referred, from the simplified and schematic motor vehicle 200 can be seen with an underbody protection element 10. In the representation of 3 is an underbody protection element 10 of 1E shown having a continuous reinforcing member 14d and the edge portions 16. It is clear that a motor vehicle 200 alternatively, an underbody protection element 10 of 1A until 1D may have, even if this is not explicitly shown.

The underbody protection elements 10 described here are connected to one another in a monolithic manner by appropriate provision and arrangement of the thermoset materials in a single forming step. The materials used allow for a light but very stable design and structure of the underbody protection element, which overall leads to a weight reduction for motor vehicle 200 while maintaining the stability required to protect electrical components, in particular the high-voltage battery of motor vehicle 200.

Claims (11)

Underbody protection element (10) for a motor vehicle (200), in particular an electric vehicle, with a formed core element (12) made from a duroplastic fiber matrix semi-finished product, in particular from a sheet or plate-like molding compound (SMC) and/or from a shapeless compound (BMC), at least one reinforcement element (14c, 14d) made of a glass fiber reinforced duroplastic material, in particular a duroplastic prepreg, the at least one reinforcement element (14c, 14d) being materially connected to the core element (12), characterized in that the underbody protection element (10) has a formed , peripheral edge section (16) made of the duroplastic fiber matrix semi-finished product, wherein the at least one reinforcement element (14c, 14d) is arranged within the area delimited by the edge section (16) in such a way that there are several rib-like elements in a longitudinal direction (LR) and Support sections (18) running in a transverse direction (QR) of the underbody protection element (10) from de m duroplastic fiber matrix semi-finished product, which protrudes beyond the at least one reinforcement element (14c, 14d) on at least one side of the underbody protection element (10), and that it has a plurality of contact sections (24) on which the underbody protection element (10) is connected with a Body of the motor vehicle (200) can be connected, contact sections (24) being arranged in crossing areas (26) of the support sections (18). Underbody protection element (10) according to claim 1 , characterized in that the rib-like support sections (18) relative to an assembled state of the underbody protection lements (10) on the motor vehicle (200) in the direction of the motor vehicle (200) protrude. Underbody protection element (10) according to claim 1 or 2 , characterized in that it has at least one heat protection element (20) which is materially connected to the core element (12) and/or to the reinforcing element (14c, 14d). Underbody protection element (10) according to one of the preceding claims, characterized in that it has at least one stiffening element (22) which is materially connected to the core element (12) and/or to the reinforcing element (14c, 14d). Underbody protection element (10) according to one of the preceding claims, characterized in that it has a plurality of reinforcing elements (14c, 14d) which are designed in the manner of strips and are arranged at a distance from one another. Underbody protection element (10) according to claim 5 , characterized in that between two adjacent strip-like reinforcement elements (14c, 14d) a rib-like support section (18) is formed. Underbody protection element (10) according to claim 5 or 6 , characterized in that it has, based on a mounted state on the motor vehicle (200), on its upper side facing the motor vehicle (200) and on its lower side facing away from the motor vehicle (200) a plurality of strip-like reinforcing elements (14c, 14d). Underbody protection element (10) according to one of the preceding claims, characterized in that contact sections (24) are distributed in the edge section (16). Method (600) for producing an underbody protection element (10) according to one of the preceding claims, comprising the steps: a) arranging (S601) at least one core material volume made of a duroplastic fiber matrix semi-finished product, in particular of sheet-like or plate-like molding compound (SMC) and/or of shapeless compound (BMC) on a processing platform; b) Reshaping (S602) of the at least one core material volume, so that the at least one core material volume forms the one-piece core element (12) with a plurality of rib-like support sections (18) running in the longitudinal direction (LR) and transverse direction (QR) of the underbody protection element (10) and with a circumferential edge portion (16) is reshaped; c) arranging (S603) at least one reinforcement element (14c, 14d) made of a glass fiber reinforced duroplastic material, in particular a duroplastic prepreg, or of a material volume for a reinforcement element, in particular a sprayed-on material mixture of cut glass fibers and a plastic, on or on the formed core element (12) between two support sections (18); d) material-locking connection of the at least one reinforcement element (14c, 14d) to the core element (12) or wet pressing of the at least one reinforcement element (14c, 14d) for material-locking connection to the core element (12). Method (600) according to claim 9 , wherein the forming (S602) of the duroplastic materials in a forming tool at a temperature of about 120 ° C. up to 165°C. is carried out. Motor vehicle (200), in particular an electrically driven motor vehicle with an underbody protection element (10) according to one of Claims 1 until 8th .

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