DE102018215003A1 - Multi-layer component - Google Patents

Abstract

Multi-layer component (1), in particular for a motor vehicle, with a middle layer (2) and at least two outer layers (3, 3 ') arranged at least in regions on opposite main extension surfaces of the middle layer (2), the middle layer (2) using an additive manufacturing process is made.

Description

The invention relates to a multilayer component, in particular for a motor vehicle.

Multi-layer components are basically known from the prior art in a large number of different embodiments for different application purposes.

These multi-layer components - also called layer components - usually have a central layer and at least two outer layers arranged on the opposite main extension surfaces of the central layer. The multilayer structure allows the component to be given specific component properties. Due to the multi-layer structure, the production process involves effort. The weight of the multilayer components of the prior art also appears to be in need of improvement.

The invention has for its object to provide an improved multi-layer component, which in particular has lower manufacturing costs and / or a lower weight.

The object is achieved by a multi-layer component according to claim 1. The dependent claims relate to possible embodiments of the multi-layer component according to claim 1.

The multi-layer component described here has a multi-layer structure and can therefore also be referred to or regarded as a laminate. A first layer of the multi-layer component is formed by the middle layer or central layer. Two further layers, the outer layers are each arranged at least in regions on one of the two opposite main extension surfaces of the middle layer. The component can have, for example, a cuboid shape, the upper and lower sides of which form the surfaces with the greatest spread and are finally in the form of the outer layers. The outer layers can form the top and bottom of the component.

At least one outer layer, preferably both outer layers, can be connected flatly to the middle layer. A predominantly flat or full-surface connection of the outer layer or the outer layers to the middle layer is advantageous.

The essence of the invention is that the middle layer is produced by means of an additive manufacturing process. By using an additive manufacturing process it is possible to give the multilayer component a high degree of design freedom, since in particular a complex course of the surface shape of the component can also be produced in a simple manner. For example, one of the following manufacturing processes can be selected as the additive manufacturing process: Selective Laser Sintering (SLS), Multi-Jet Fusion (MJF), Continuous Liquid Interface Production (CLIP) and / or Stereolithography (SLA). An advantage of the specified methods is that, in addition to the production of prototypes, they can also be used for the production of series components and, if necessary, by changing the process parameters during or after the manufacturing process, the component properties within the component can be changed or set in a targeted or defined manner.

In an advantageous embodiment, the central layer consists of a core region and at least two surface regions arranged on opposite main extension surfaces of the core region, the surface regions of the central layer preferably having a layer-like and / or a flat shape. The outer layers can each be arranged on a surface area of the middle layer. The component or material properties of the surface areas of the middle layer can differ from the component or material properties of the core area of the middle layer. For this purpose, it is advisable to set specific component area properties in the course of the additive manufacturing process of the middle layer by means of different process parameters and / or by a different type of geometric shape of the built-up material. Typically, changeable process parameters of an additive manufacturing process, depending on the specific process, can include the following: exposure intensity, exposure speed, cooling time, change of building material and process temperature. The layer-like shape of the surface area can be flat at least in some areas. Alternatively or additionally, the layer-like shape of the surface area can have at least one curvature in at least one spatial area in at least one spatial plane. In particular, geometries with curvatures in at least two directions can be achieved for the component and / or for at least one surface area, at least in regions.

In a preferred embodiment, the middle layer produced by the additive manufacturing process consists of plastic, in particular synthetic resin. This material allows the production of a lightweight component with a high degree of design freedom for the geometry of the middle layer.

The core area can have a lattice-like structure at least in some areas, preferably the core area has a lattice-like structure that is at least in some areas regular. The grid-like structure allows the creation of cavities in the area of the middle layer and thus in the interior of the component. These voids lead to one Reduction of component weight. In a particularly stable embodiment, the lattice-like structure can also form a honeycomb structure. In other words, a lattice-like structure can be formed by a lattice with a plurality of support-like lattice elements arranged or aligned in at least two directions. The spacing of the lattice elements defines cavities which, for example, can also form a porous structure.

As an alternative or in addition, the core region can have an at least regionally irregular lattice-like structure, preferably first lattice elements of a first region of the core region being designed differently from second lattice elements of a second region of the core region, particularly preferably first lattice elements compared to the second lattice elements with regard to thickness , Length, orientation, shape and / or distance are formed differently. The irregular lattice-like structure makes it possible, through the targeted design of the irregular lattice-like structure, to “set” the material or component properties of the middle layer and thus ultimately also of the multi-layer component already in the additive manufacturing process due to the geometry of the core area. In areas with higher mechanical stresses when the component is used as intended, the grid-like structure can be reinforced in comparison to areas not stressed to this extent. That e.g. that the lattice elements of two areas of the core area have a difference in cross-sectional contour and thickness compared to each other. It can also be provided that the lattice-like structure of the core area is completely irregular, so that there is a different design of the lattice elements at each area of the core area.

Furthermore, it has proven to be advantageous if at least a first surface area of the central layer closes at least 50% of a first main extension surface of the core area, preferably closes at least 90% of a first main extension surface of the core area, particularly preferably completely closes a first main extension surface of the core area. The surface area of the middle layer can also be understood as an area with the function of connecting the middle layer as well as possible to the adjacent outer layer. In this case, for example, a minimum contact area for the flat connection of the outer layer and middle layer can be sought. In the case of a core area which is designed like a grid in its interior, the at least area-wise closing, covering or closing off the grid-like edge area, i.e. the surface area of the middle layer, can provide a connection-promoting minimum contact area of the middle layer for the connection to the outer layer.

This can also be applied analogously to the second surface area, so that at least a second surface area of the central layer closes at least 50% of a second main extension surface of the core region opposite the first main extension surface, preferably at least 90% of a second main extension surface of the core region opposite the first main extension surface , particularly preferably completely closes a second main extension surface of the core region opposite the first main extension surface.

In a further advantageous embodiment, the at least one outer layer has fiber-reinforced plastic, glass and / or metal, the outer layer preferably having reinforcing fibers and a plastic matrix, where (a) the reinforcing fibers: glass fibers, carbon fibers, ceramic fibers and / or aramid fibers, and / or (b) the plastic matrix has a thermoset or thermoplastic matrix, in particular polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polysulfone (PSU), polyether imide (PEI) and / or polytetrafluoroethylene (PTFE). By using fiber-reinforced plastic, glass and / or metal for the at least one outer layer, preferably for both outer layers, the mechanical strength of the component and in particular the strength and flexural strength can be increased with a low component weight. This can essentially result in a separation of functions, according to which the outer layer (s) have a high strength and the middle layer has a lower strength. The bending strength of the component itself can be achieved by a preferably large separation distance between the two outer layers. The separation distance is achieved through the shape of the middle layer, which essentially "bridges" the separation distance. It can also be advantageous if the reinforcing fibers are designed as a unidirectional layer. A unidirectional layer is a layer of a fiber-plastic composite in which at least predominantly, preferably all, fibers are oriented in a single direction.

If the plastic matrix is designed as a thermoset matrix, it can consist of epoxy resin (EP), unsaturated polyester resin (UP), vinyl ester resin (VE), phenol-formaldehyde resin (PF), diallyl phthalate resin (DAP), methacrylate resin (MMA), polyurethane (PUR), amino resins , Melamine resin (MF / MP) and / or urea resin (UF) can be formed.

It can further be provided that all outer layers of a component have the same reinforcing fibers, preferably have the same fiber-reinforced plastic.

The at least one outer layer can be attached to the middle layer in a material, non-positive or positive manner, preferably the at least one outer layer is integrally connected to the middle layer, i.e. e.g. by welding and / or gluing. Welding in particular is advantageous because there is no longer any need for an intermediate layer. An at least cohesive connection of the middle layer with at least one outer layer can also be achieved through the targeted use of an intermediate product status of the middle layer within its additive manufacturing process. For example, in a SLA process, the middle layer can first be produced in a first stage, forming its essential geometric shape (also referred to as green body). In a second stage, the middle layer or green body is subjected to post-curing. The post-curing takes place, for example, by applying thermal and / or UV light to the central layer or the green body, so that the finished central layer is then present. In the status of the green compact, the middle layer can have at least one surface that is not yet fully hardened and has a sticky property. This sticky surface property of the green compact can be used for at least materially connecting the middle layer to at least one outer layer. Provision can also be made for the green compact to be subjected to a cleaning process prior to post-curing. With this cleaning process, the sticky property is at least reduced on the cleaned areas. Advantageously, the areas of the middle layer that are not in contact with at least one outer layer are advantageously cleaned in the cleaning process, so that the sticky property of the middle layer present as a green body is available for connecting the at least one outer layer. Advantageously, the cleaning prior to post-curing can be limited to at least parts of the core area.

In order to achieve a good connection between the middle layer and the outer layer, it has proven to be advantageous if at least one surface area of the core area has at least one receiving area for receiving at least a part of the outer layer, preferably the receiving area is designed as a recess. The receiving area or the recess can be a contact area of the middle layer with the outer layer, which deviates from a flat shape or from a superordinate body contour (e.g. a regular superordinate geometrical body contour), preferably through the surface area of the middle layer. Generally speaking, the surface area of the middle layer can be enlarged by means of highlights and / or recesses in order to achieve a larger contact area between the middle layer and the outer layer. These highlights can be present, for example, as a regular or irregular surface structure at least in some areas on the surface area of the middle layer. This surface structure can preferably have a low height (extension perpendicular to the main extension plane of the component) of, for example, in the range from one twentieth to half the layer thickness of the outer layer. This measure, which enlarges the contact area of the middle layer and outer layer or of the surface area of the middle layer and outer layer, reinforces the adherence or the fastening. The receiving area and / or the recess can be designed in such a way that at least the material of the outer layer received in the receiving area and / or in the recess is arranged in a layer-like, strand-like and / or band-like manner as strand or strip material. The material introduced into the receiving area can also be present as strand and / or strip material during its attachment. Furthermore, it has proven to be advantageous if the receiving area of the central layer has at least one undercut area. The undercut area is to be understood as an area that is not exposed in a direction perpendicular to the main extension plane of the central layer, i.e. that this area for inserting an element with the joining direction is not exposed in the direction perpendicular to the main extension plane of the central position. In a preferred embodiment, an area of the middle layer on the surface area of the middle layer is provided with one, in particular several, L, T or mushroom-shaped element which forms at least one cavity or undercut area. For example, the outer layer can be formed as a fiber material such that the fiber material is placed on the surface of the middle layer. Resin in liquid form, for example, is added as a matrix of this outer layer, which also penetrates into the undercut areas and, after it has hardened, thus forms a middle layer consisting of fibers and matrix, which acts as a cohesive connection component in the z direction (perpendicular to the main extension plane of the middle layer) has the connection between the middle layer and the outer layer.

The receiving area and / or the recess can also be arranged in a transition area and this transition area can be arranged in the area of the transition from the central position to an outer layer, the outer layer covering a main extension surface of the component at least in regions, in particular over the entire surface. By providing a transition area, a good connection of, for example, full-surface layers of the External position reached with the middle layer. A transition area designed in this way results in a type of toothing and / or, at least in part, a type of positive connection for the connection of the middle layer and the outer layer.

The multi-layer component is preferably installed in a motor vehicle and can be specifically adapted to meet crash requirements, in particular in its design of the outer layer and central position, in particular in the design of the lattice-like structure of the core area. For example, the component can be used as a frame component, a partition component between the engine compartment and the passenger compartment and / or as a door or flap component.

• - Bereitstellen einer in einem additiven Fertigungsverfahren hergestellten Mittellage,
• - Bereitstellen zweier Außenlagen,
• - Verbinden der beiden Außenlagen an je einer der sich gegenüberliegenden Haupterstreckungsoberflächen der Mittellage.

The following process steps have proven to be advantageous for producing a multilayer component:

• Provision of a middle layer produced in an additive manufacturing process,
• - provision of two outer layers,
• - Connect the two outer layers on one of the opposite main extension surfaces of the middle layer.

The outer layers can preferably be produced in a different production process from the production process of the middle layer. The different manufacturing processes can differ in terms of the manufacturing method, the manufacturing material and / or the manufacturing parameters.

• 1 eine schematische Prinzipdarstellung eines mehrlagigen Bauteils gemäß einer ersten Ausführungsform;
• 2 eine schematische Prinzipdarstellung eines mehrlagigen Bauteils gemäß einer weiteren Ausführungsform;
• 3 eine schematische Prinzipdarstellung eines mehrlagigen Bauteils gemäß einer weiteren Ausführungsform.

The invention is described in more detail using exemplary embodiments in the drawings. It shows:

• 1 a schematic diagram of a multi-layer component according to a first embodiment;
• 2 a schematic diagram of a multi-layer component according to another embodiment;
• 3 is a schematic diagram of a multi-layer component according to another embodiment.

1 shows a multilayer component 1 comprising a middle layer produced in an additive manufacturing process 2 and two, on opposite main extension surfaces of the middle layer 2 arranged outer layers 3 . 3 ' ,

The middle layer 2 has a first surface area on a first main extension surface 4 , and on the opposite main extension surface a second surface area 4 ' on. Between the two surface areas 4 . 4 ' shows the middle layer 2 a core area 5 on. The core area 5 the middle position 2 has a grid-like structure and includes grid elements 6 , Between the grid elements 6 points out the core area 5 Cavities 7 on.

The outer locations 3 . 3 ' are formed in the illustrated embodiment as a fiber-reinforced material that is on the middle layer 2 applied after their manufacture as a layer-like and / or flat material and with the middle layer 2 is connected. The fibers of the fiber-reinforced material are schematic on the cross-sectional area 8th of the component 1 as points 9 shown.

In the transition from the middle position 2 to the outer locations 3 . 3 ' can be seen that still within the middle position 2 the lattice-like structure changes into a closed, flat structure. The first surface area 4 the middle position 2 can, for example, 50% of a first main extension surface 11 of the core area 5 lock or cover. The same applies to that of the first main extension surface 11 opposite main extension surface 11 ' the middle position 2 , for example, at least 50% of the second surface area 4 ' is completed or covered. In other words, the lattice-like, with cavities 7 provided structure of the core area 5 to the edges or to the outer layers 3 . 3 ' contacting surface areas 4 . 4 ' closed at least in some areas, in order to find a suitable size of the contact surface for the middle layer 2 with the outer layers 3 . 3 ' to show.

The outer locations 3 . 3 ' are by welding and / or gluing to the middle layer 2 connected.

According to the in 1 The embodiment shown are the two surface areas 4 . 4 ' the middle position 2 essentially flat and preferably flat. In this case it has proven to be advantageous if the at least two surface areas 4 . 4 ' the middle position 2 one by a maximum of the factor 5 different layer thickness 13 . 13 ' have, preferably a layer thickness different by a maximum of 2.5 times 13 . 13 ' have, particularly preferably a layer thickness different by a maximum of a factor of 1.25 13 . 13 ' exhibit. It can also be provided that the layer thicknesses 13 . 13 ' of the two essentially flat surface areas 4 . 4 ' an essentially identical layer thickness 13 . 13 ' exhibit. As a layer thickness 13 . 13 ' is the thickness of the surface area extending perpendicular to the main extension surface 4 . 4 ' to understand.

With regard to the design of the surface areas 4 . 4 ' relative to the core area 5 it has proven to be advantageous if the layer thickness 13 . 13 ' of the surface area 4 . 4 ' to the layer thickness 14 of the core area 5 has a maximum of a ratio of 1.0, preferably a maximum of a ratio of 0.1, particularly preferably a maximum of a ratio of 0.01.

For the dimensioning of the outer layer 3 . 3 ' relative to the surface area 4 . 4 ' the middle position 2 it has proven to be advantageous if the layer thickness 13 . 13 ' of the surface area 4 . 4 ' the middle position 2 to the layer thickness 10 . 10 ' the outside location 3 . 3 ' has a ratio in the range from 0.1 to 10, preferably a ratio in the range from 0.5 to 5, particularly preferably has a ratio in the range from 0.75 to 2.5.

In 2 the top has an intermittent (broken areas 15 . 15 ' ) provided external location 3 on. The areas interrupted in the flat surface 15 . 15 ' are due to the material of the middle layer 2 filled. The bottom of the component 1 has one due to the outside location 3 ' closed surface, analogous to the embodiment of 1 , Alternatively or additionally, the underside can have an interrupted outer layer 3 ' how the top of the component 1 the 2 , exhibit.

The broken area 15 . 15 ' the outside location 3 can also be used as a highlighted area of the middle layer 2 be interpreted. Between the highlights of the middle layer 2 become reception areas 12 . 12 ' to accommodate at least part of the outer layer 3 educated. As shown, the recording area can 12 . 12 ' a recess in the middle layer 2 form. The recording area 12 . 12 ' or the recess of the middle layer 2 increases the contact area between the outer layer 3 and the middle layer 2 , for example in the area of the arrow 16 the material of the outer layer arranged there 3 from three sides of the material of the middle layer 2 surround. As a result, the effective area for a material connection between the outer layer increases 3 and middle position 2 , The middle layer 2 has band-like or groove-like receiving areas in the illustrated embodiment 12 or recesses by the material of the outer layer 3 is filled. For example, the groove-like receiving areas 12 or recesses selected such that a band-like and / or strip-like outer layer material can be inserted. By filling in the cross-sectional area 8th crenellated structure becomes a better connection of middle layer 2 and outside location 3 reached. At least in the X direction for the connection of the middle layer 2 and outside location 3 also a positive locking component.

Further in the in 3 embodiment shown the component 1 to 2 an outer outer layer 17 on an interrupted outer layer 18th upset. The outer layer 17 and the broken outer layer 18th together form the outer location 3 , The interrupted outer layer 18th forms a strong material connection with the other outer layer 17 due to the uniformity of the material. Due to the interrupted outer layer 18th and their good connection with the middle layer 2 will also be an overall good combination of middle layer 2 and outside location 3 reached. In other words, the area of the interrupted outer layer layer 18th , that is the area covering the recording area 12 and / or has the recess as a transition region 19 be designated. The transition area 19 is essentially in the area of the transition from the middle position 2 to the outside location 3 arranged, the outer layer 3 a main extension surface of the component, at least in regions, in particular over the entire surface 1 covers.

Claims (14)

Multi-layer component (1), in particular for a motor vehicle, with a central layer (2) and at least two outer layers (3, 3 ') arranged at least in regions on opposite main extension surfaces of the central layer (2), characterized in that the central layer (2) is produced by means of an additive manufacturing process. Multi-layer component (1) after Claim 1 characterized in that the central layer (2) consists of a core region (5) and at least two surface regions (4, 4 ') arranged on opposite main extension surfaces of the core region (5), the surface regions (4, 4') of the central layer ( 2) preferably have a layer-like and / or a flat shape. Multi-layer component (1) after Claim 1 or 2 , characterized in that the middle layer (2) produced by the additive manufacturing process consists of plastic, preferably the middle layer (2) consists of synthetic resin. Multi-layer component (1) according to one of the preceding claims, characterized in that the core region (5) has a lattice-like structure at least in regions, preferably the core region (5) has a regular lattice-like structure at least in regions. Multi-layer component (1) after Claim 4 , characterized in that the core region (5) has an at least regionally irregular lattice-like structure, preferably the first Lattice elements (6) of a first area of the core area (5) are designed differently in comparison to second lattice elements of a second area of the core area (5), with first lattice elements (6) being particularly preferred in terms of thickness, length, orientation, in comparison to the second lattice elements. Shape and / or distance are different. Multi-layer component (1) after Claim 5 , characterized in that at least a first surface area (4) of the central layer (2) closes at least 50% a first main extension surface of the core area (5), preferably closes at least 90% a first main extension surface of the core area (5), particularly preferably completely one completes the first main extension surface of the core region (5). Multi-layer component (1) according to one of the Claims 5 or 6 , characterized in that at least a second surface area (4 ') of the central layer (2) closes at least 50% of a second main extension surface of the core region (5) opposite the first main extension surface, preferably at least 90% of a second main extension surface opposite the first main extension surface of the core region (5), particularly preferably completely, closes a second main extension surface of the core region (5) opposite the first main extension surface. Multi-layer component (1) according to one of the preceding claims, characterized in that the at least one outer layer (3, 3 ') comprises fiber-reinforced plastic, glass and / or metal, the outer layer (3, 3') preferably having reinforcing fibers and a plastic matrix , wherein - the reinforcing fibers: glass fibers, carbon fibers, ceramic fibers and / or aramid fibers, and / or - the plastic matrix is a thermoset or thermoplastic matrix, in particular polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polysulfone (PSU), polyetherimide (PEI) and / or have polytetrafluoroethylene (PTFE). Multi-layer component (1) according to one of the preceding claims, characterized in that the at least one outer layer (3, 3 ') is attached to the central layer (2) in a material, non-positive or positive manner, preferably the at least one outer layer (3, 3 ') connected to the middle layer (2) by welding and / or gluing. Multi-layer component (1) according to one of the Claims 2 to 9 , characterized in that at least one surface area (4, 4 ') of the core area (5) has at least one receiving area (12) for receiving at least a part of the outer layer (3, 3'), preferably the receiving area (12) is designed as a recess . Multi-layer component (1) after Claim 10 , characterized in that the receiving region (12) and / or the recess is arranged in a transition region (19) and the transition region (19) is arranged in the region of the transition from the middle layer (2) and an outer layer (3), the Outer layer (3) covers a main extension surface of the component (1) at least in some areas, in particular over the entire surface. Multi-layer component (1) according to one of the preceding claims, characterized in that the middle layer (2) is produced by means of one of the following production processes: selective laser sintering (SLS), a multi-jet fusion (MJF), a continuous liquid interface production ( CLIP) and / or a stereolithography (SLA). Motor vehicle, with a multi-layer component (1) according to one of the Claims 1 to 12 , Method for producing a multilayer component (1), in particular according to one of the Claims 1 to 12 , comprising the following process steps: - providing a middle layer (2) produced in an additive manufacturing process, - providing two outer layers (3, 3 '), - connecting the two outer layers (3, 3') to one of the opposite main extension surfaces of the middle layer ( 2).

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