WO2023169684A1

WO2023169684A1 - Method and device for additive manufacturing of workpieces with regions of heterogeneous filling structures

Info

Publication number: WO2023169684A1
Application number: PCT/EP2022/056208
Authority: WO
Inventors: Daniel Wimmer
Original assignee: Daniel Wimmer
Priority date: 2022-03-10
Filing date: 2022-03-10
Publication date: 2023-09-14

Abstract

The invention relates to a method for additive manufacturing, in particular for 3D printing, comprising the following steps: - providing topography data (11) and material parameters (15) of a template object (10); - calculating a virtual structure model (30) and a virtual strength model (40) of a three-dimensional model object (100); - modelling a three-dimensional virtual data model (50) of the model object (100); - subdividing the virtual data model (50) into at least two virtual object sections (51, 52, 53) with different component loading capacity and/or component mobility; - selecting and adjusting at least one fractal curve type (70, 71, 72, 73) of a space filling curve (60, 61, 62, 63) with a fractal dimensionality (D.70) for each virtual object section (51, 52, 53) of the virtual data model (50) on the basis of stored strength data (41, 42, 43), until a three-dimensional optimum virtual data model (90) is obtained, which comprises coordinate points (101, 102, 103) for the additive manufacturing of the model object (100); - subdividing an overall height (H.90) of the optimised three-dimensional virtual data model (90) into a number N of sequential height layers (111,112,113) of the model object (100) stacked one on top of another; - applying the N height layers (111, 112, 113) of the model object (100) layer by layer, by means of a manufacturing device for additive manufacturing, preferably with a 3D printing device, in order to manufacture the model object (100).

Description

METHOD AND DEVICE FOR THE ADDITIVE MANUFACTURING OF WORKPIECES WITH AREAS OF HETEROGENE FILLING STRUCTURES

FIELD OF THE INVENTION

The invention relates to a method for additive manufacturing, in particular for 3D printing of workpieces, in which a corresponding manufacturing device for additive manufacturing, preferably a 3D printing device, is used to produce a model object.

Furthermore, within the scope of the invention, a control for a corresponding manufacturing device for additive manufacturing and a manufacturing device with a control according to the invention are specified.

STATE OF THE ART

The term “additive manufacturing” includes all manufacturing processes in which material is applied layer by layer and three-dimensional workpieces are created. In particular, 3D printing processes are among the established additive manufacturing processes. The layer-by-layer construction is usually carried out under computer control from one or more liquid or solid materials according to specified dimensions and shapes. Physical or chemical hardening or melting processes take place during construction. Typical materials for 3D printing include plastics, synthetic resins, ceramics and specially prepared metals. metal powder.

It is known from the prior art that the additive manufacturing of components, in particular the production of 3D printed parts, is important in terms of material consumption and, as a result, in terms of production time. Optimize the duration of 3D printing. As a rule, components are made layer by layer using a so-called FFF process (short for: “Fused Filament Fabrication”; fused layer process), for example from one meltable plastic or made from molten metal are not made from a solid material, as the additive manufacturing of components from solid material is usually too time-consuming. In order to save processing time and material usage, simple filling structures with internal cavities are usually used to produce workpieces in the form of 3D printed parts to build up internal sections of such a workpiece. Depending on the area of application and the given load capacity of the workpiece, different filling structures with different filling rates of the filling material can be used.

For example, an additive manufacturing process for porous 3D structures has become known from the publication US 2012299917 Al. First, a virtual model of an object is read in, the virtual model containing both geometry data and material data such as porosity or density distribution. The model is divided into surface layers, taking into account the geometry model and the material model for each layer. For each surface layer, a single continuous, fractal, space-filling curve is generated, which is adapted as far as possible to the specified material data.

The term “space-filling curve” refers to a line that completely passes through a two-dimensional surface or a multi-dimensional space or a regular grid that describes this surface and/or this space.

The publication US 2014039659 Al shows a method and system for the structural analysis and automatic adjustment of a model for 3D printing. After reading in a source model, for example as an STL description, a preliminary filling is determined, after which the structural analysis is started, whereby critical areas are identified and the structure of the model can be automatically modified. The disadvantage of currently known methods for modeling three-dimensional workpieces for an additive manufacturing process is at least that the division of a virtual data model of the workpiece into height layers, each with one and the same, uniform layer height or uniform layer height.

Another disadvantage is that the filling structures for building internal sections of such a workpiece are usually made from a single filling material, with the one filling material for building internal workpieces each having the same, uniform material width or uniform layer width is applied. An individual adaptation to locally different component loads of the workpiece to be manufactured is only inadequately possible with the currently available methods for modeling three-dimensional workpieces for additive manufacturing processes.

OBJECT OF THE INVENTION

It is therefore an object of the invention to overcome the disadvantages of the prior art and to provide a novel method for additive manufacturing in which locally different component loads on the workpiece to be manufactured are taken into account.

Furthermore, one of the tasks according to the invention is to propose a method that is as flexible and sustainable as possible, with both template objects with simple geometry and template objects with complex geometry, for example internal recesses and / or sections with porous structures, in particular with graded porosity and / or graduated density, each can be manufactured as time-saving and material-friendly as possible and taking into account locally different component loads.

Further objects of the invention are a control for a corresponding manufacturing device for additive manufacturing and to specify a manufacturing device with a control according to the invention, which is suitable for carrying out such a novel method for additive manufacturing.

PRESENTATION OF THE INVENTION

These tasks are solved using a method according to the invention for additive manufacturing, in particular for 3D printing, the method comprising the following steps:

-a- Providing topography data of a physical three-dimensional template object;

-b- Provide material characteristics of the template object;

- c- computer-aided calculation of a virtual structural model of a three-dimensional model object depending on the topography data of the template object provided in step -a-;

-d- Computer-aided calculation of a virtual strength model of the three-dimensional model object depending on the material characteristics of the template object provided in step -b-, whereby strength data on the component load capacity and / or component mobility of the model object are obtained;

-e- Computer-assisted modeling of the virtual structural model and the virtual strength model into a three-dimensional virtual data model of the model object;

-f- Computer-aided division of the virtual data model of the model object into at least two virtual object sections with different component load capacity and/or component mobility;

-g- Selecting at least one fractal curve type of a space-filling curve with a fractal degree of dimension for each of the at least two virtual object sections of the virtual data model, wherein the at least one fractal curve type and / or the fractal degree of dimension for the respective virtual object section of the virtual data model is selected based on strength data stored in the virtual data model for component load capacity and/or component mobility or become; -h- Adjusting at least one individual curve profile and at least one individual curve width of the selected at least one fractal curve type of the space-filling curve within the respective virtual object section for each of the at least two virtual object sections of the virtual data model based on strength data on component load capacity stored in the virtual data model and/or component mobility;

-i- If necessary, repeat step -g- to select at least one fractal curve type of a space-filling curve with a fractal degree of dimension for one or more virtual object sections of the virtual data model and / or repeat step -h- to adapt the respective individual curve profile individual curve width of the at least one selected space-filling curve for one or more virtual object sections of the virtual data model until the curve courses of space-filling curves for all virtual object sections of the virtual data model are adapted to the strength data stored in the virtual data model for component load capacity and / or component mobility and a three-dimensional optimized virtual data model is obtained, which includes optimized virtual data model coordinate points for the additive manufacturing of the model object;

-j - Computer-aided division of a total height of the optimized three-dimensional virtual data model into a number N (N

2 to n) of sequentially stacked height layers of the model object, each of the N (N

2 to n) height layers of the model object correspond to a single substructure of the optimized virtual data model and include coordinate points for the additive manufacturing of the corresponding height layer of the model object, where the number N is an integer which is greater than or equal to the number 2, and where the number N (N

2 to n) is selected so that each of the N (N 2 to n) height layers each has an individual partial height adapted to the component load capacity and/or component mobility of the respective object section, whereby the sum of the N (N 2 to n) partial heights of the individual height layers correspond to the total height of the optimized three-dimensional virtual data model;

-k- layer-by-layer orders of the N (N

2 to n) sequentially stacked height layers of the model object using a manufacturing device for additive manufacturing, preferably with a 3D printing device, in order to manufacture the model object.

The specified method according to the invention is not in itself limited to a specific sequence of the individual process steps. In particular, if necessary, individual or several process steps can also be repeated several times, for example in the form of one or more partial sequences of the process, before further, subsequent process steps are carried out. Depending on the application, for example, the two process steps -a- and -c- and/or the two process steps -b- and -d- can each be carried out directly one after the other without an intermediate step.

However, the method according to the invention is preferably carried out in the order of method steps -a- to -k- specified here in order to produce a three-dimensional object starting from a physical, three-dimensional template object using a manufacturing device for additive manufacturing, preferably with a 3D printing device to produce a model object. However, if necessary, according to step -i-, steps -g- and / or -h- can be repeated once or several times. For the sake of simplicity, the specified order of process steps -a- to -k- is followed for the further description.

The method according to the invention is applicable to all additive manufacturing techniques, such as, but not limited to, 3D printing, enamel from divorce, stereolithography, selective laser sintering, direct material deposition, or layer manufacturing (abbreviated: LM; English: "laminar manufacture") However, the specified manufacturing process is preferably intended for 3D printing. In detail, at the beginning of the method in step -a-, corresponding topography data of a physical three-dimensional template object, which serves as a template for the model object to be produced, are provided.

The concept of a physical three-dimensional template object or “3D” template objects also include so-called “2, 5D” objects, i.e. those objects and structures that are in themselves three-dimensional, but which, for example, do not have a defined lower edge and/or which can have undercuts. For example, spherical lenses used for optical applications that are rounded at their bottom edges are referred to as 2.5D objects. Such 2.5D template objects can also serve as a template for 2.5D model objects that are additively manufactured using the method according to the invention.

The term “topography data” also means information data on the position, geometry and structuring of the outer surfaces or outer contours of the template object as well as, if necessary, information data from structures located within the template object, for example porous structures, cavities, undercuts and the like. In a three-dimensional Cartesian coordinate system, for example, a template object for acquiring topography data can be aligned in such a way that a flat structural section of the template object can be specified with a length in the X-axis direction and a width in the Y-axis direction. Structure heights of a surface of the template object can also be specified a microstructure can be specified, for example, in the Z-axis direction, with the Z-axis direction serving as a height display of the template object or structures of the template object. Depressions within the template object can therefore be specified, for example, as structure depths in the negative Z-axis direction.

The next step -b- involves providing material characteristics of the template object. The term “Material characteristics” includes, for example, information data on the application area of the template object, the material properties, density, porosity, as well as the type of load and/or level of load on the template object.

The method according to the invention further comprises, according to step -c-, a computer-aided calculation of a virtual structural model of a three-dimensional model object depending on or taking into account the topography data of the template object provided in step -a-. Starting from the topography data of the template object, which is specified as a spatial data set in the form of discrete coordinate points, for example as XYZ coordinate points in Cartesian coordinates, a virtual structural model can be calculated with the aid of a computer. The term "voxel", an English combination of the abbreviation syllables "vox" for "volume" and "el" for "elements", is used in computer graphics to mean a grid point or image point in a three-dimensional grid For a spatial data set that is in discrete form in Cartesian coordinates, voxel refers to the discrete value at an XYZ coordinate of the data set.

The term “computer-assisted” here means the use of one or more computers to support the execution of calculation tasks.

In step -d-, a computer-aided calculation of a virtual strength model of the three-dimensional model object takes place depending on or taking into account the material characteristics of the template object provided in step -b-. With the help of the calculated virtual strength model, strength data on the component load capacity and/or component mobility of the model object are obtained. Depending on the application, different scenarios of component loads can be taken into account, such as basic load types using compressive loads, tensile loads, shear loads, torsional loads and/or bending loads. The selected basic load types can be used either as a single load case or as a combined one Load cases, whereby two or more load cases are superimposed accordingly, are taken into account.

This selection of a possible load case or a combination of two or more superimposed load cases serves to calculate corresponding strength data for the component load capacity and/or component mobility of the model object. Movable and/or rigid sections or Parts of the model object are taken into account in the virtual strength model. The strength data determined in this way are subsequently used to select at least one suitable fractal curve type of a space-filling curve.

In step -e-, computer-aided data from the virtual structural model and the virtual strength model are combined with one another and modeled into a three-dimensional virtual data model of the model object. The three-dimensional virtual data model therefore contains information about the structure or Topography, as well as strength data on the component load capacity and/or component mobility of the model object in question.

In step -f-, the virtual data model of the model object is divided, with computer assistance, into at least two or more virtual object sections with different component load capacity and/or component mobility. Advantageously, two or more virtual object sections, in which different requirements exist with regard to component load capacity and/or component mobility, can each be individually examined in more detail. The size, location, arrangement or Positioning of the two or more virtual object sections relative to each other and in relation to the virtual data model can be individually adapted to the respective requirements. The more detailed the subdivision of the virtual data model is, the more precisely the subsequent calculation and individual adaptation of the virtual data model for the additive manufacturing of the model object can be carried out. Preferably, regular grid structures can be used to subdivide the virtual data model into small parts, with a cube-shaped grid element, for example, corresponding to a virtual object section. Likewise, within the scope of the invention, when dividing the virtual data model, it is provided to select a virtual object section or several virtual object sections on such a small scale that a single grid point or a single voxel, corresponding to a single coordinate point with an XYZ coordinate of the model object to be manufactured, each forms its own virtual object section. In extreme cases, within the scope of the invention, the virtual data model can be divided into a number of virtual object sections, with each individual grid point or Voxel corresponds to its own virtual object section. However, the calculation effort also increases as the number of virtual object sections selected increases.

Subsequently, in step -g-, at least one fractal curve type of a space-filling curve is selected with a fractal degree of dimension for each of the at least two or more virtual object sections of the virtual data model, wherein the at least one fractal curve type and / or the fractal degree of dimension for the j respective virtual object section of the virtual data model is selected based on strength data stored in the virtual data model for component load capacity and/or component mobility or become .

As already mentioned at the beginning, the use of space-filling curves generally makes it possible to form mathematically defined, line-shaped structures that completely pass through a two-dimensional surface or a multi-dimensional space or a regular grid that describes this surface and/or this space. By adapting a suitable curve, it is possible to use a one-dimensional curve to fill a two-dimensional plane or a three-dimensional space in such a way that the space-filling curve can be drawn in one go without intersecting itself. For the sake of simplicity, curves that fill the area are also used Fill the area of a two-dimensional surface and form a two-dimensional “2D” curve, also referred to below as space-filling curves.

By definition, fractals or Fractal curves refer to those mathematical functions that describe the course of certain natural structures such as coastlines or contour lines of snowflakes, or the course of artificial structures and geometric patterns. These structures or patterns generally do not have an integer dimension in the sense of, for example, a two-dimensional "2D" curve or a three-dimensional "3D" curve, but rather have a broken or fractal dimension, where the fractal dimension does not have to be an integer. In addition, fractal curves also have a high degree of scale invariance or self-similarity. This is the case, for example, when an object consists of several reduced copies of itself. Geometric objects of this type differ from ordinary smooth figures in important aspects.

The fractal dimension can be used in surface physics to characterize surfaces and is used here to classify and compare surface structures.

When producing a fractal space-filling curve, for example by extrusion using a 3D printing process, it is advantageous that if the curve shape is correctly calculated during layer-by-layer printing, no overhangs are produced and errors in layer adhesion between the adjacent height layers printed one above the other can therefore be avoided.

When selecting whether a two-dimensional "2D" curve or a three-dimensional "3D" curve is better suited as a space-filling curve for adapting to the individual requirements with regard to the component load capacity and/or component mobility in a virtual object section of the virtual data model, can In addition, the question of the degree of freedom of the curve type selected must also be taken into account. A two-dimensional one "2D" curve as a space-filling curve has only two degrees of freedom corresponding to the two axis directions or the pair of axes that span the surface plane in which the two-dimensional "2D" curve under consideration lies. The use of a three-dimensional "3D" curve as a space-filling curve offers the advantage that such a three-dimensional "3D" curve has three degrees of freedom and can therefore be adapted particularly easily and flexibly to local requirements with regard to component load capacity and/or component mobility in a virtual object ect section of the virtual data model can be adjusted.

In step -h-, at least one individual curve profile and at least one individual curve width of the selected at least one fractal curve type of the space-filling curve are then adapted within the respective virtual object section for each of the at least two virtual object sections of the virtual data model based on the virtual Strength data stored in the data model for component load capacity and/or component mobility. Advantageously, within a virtual object section, an individual curve profile and an individual curve width of a space-filling curve or several individual curve profiles of several space-filling curves, each with individual curve widths, can be adapted to the component requirements in this virtual object section. By appropriately selecting the fractal curve type and the individual curve width of a selected space-filling curve, the individual curve course of a or Each space-filling curve within the virtual object section under consideration must be adapted to the locally required strength data of this object section.

As already stated before, the virtual object sections can be subdivided down to individual grid points or Voxels are broken down, which is why it is possible within the scope of the method according to the invention, with a correspondingly small subdivision in step -f-, the curve width and the Curve progression individually for individual grid points or Adjust voxels.

According to step -i-, if necessary, step -g- and/or step -h- can be repeated until the curve progressions of space-filling curves for all virtual object sections of the virtual data model are adapted to the strength data stored in the virtual data model for component load capacity and/or component mobility and a three-dimensional optimized virtual data model is obtained, which includes optimized virtual data model coordinate points for the additive manufacturing of the model object. In the optimized virtual data model, the individually adapted curve profiles of the selected space-filling curves are already stored in such a way that, for example, transitions between adjacent curve sections with different curve widths are smoothed in order to simultaneously smooth local stress curves with corresponding component loads. The optimized virtual data model already contains information data required for the additive manufacturing of the model object, in particular information about coordinate points of the model object.

For the layered or However, the model object must be produced layer by layer in step -j - using computer support, the total height of the optimized three-dimensional virtual data model must be divided into a number N (N

2 to n) height layers of the model object correspond to a single substructure of the optimized virtual data model and include coordinate points for the additive manufacturing of the corresponding height layer of the model object. Advantageously, in the method according to the invention, the number N of height layers is selected so that each of the N height layers has an individual partial height adapted to the component load capacity and/or component mobility of the respective object section, the sum of the N partial heights of the individual height layers corresponds to the total height of the optimized three-dimensional virtual data model. Particularly advantageously, with the method according to the invention, both the individual curve width or Layer width of the individually selected curve of a space-filling fractal curve, as well as the individual partial heights of the individual partial structures or Elevation layers can each be flexibly adapted to the local requirements regarding the component load capacity and/or component mobility of the respective object section.

For example, particularly heavily loaded object sections with a high or maximum filling rate of the filling material - comparable to a rigid solid material. This can be achieved by increasing the local curve width or Layer width and thus the material width of the filling material in such a heavily loaded object section of the model object is selected as wide as possible. The partial height or Layer height of the substructures or Elevation layers are expediently chosen to be as low as possible in such a heavily loaded object section in order to create as many elevation layers as possible, each with the lowest possible partial height or height, by applying them layer by layer. Layer height to achieve a maximum filling material application in the loaded object section.

Conversely, lightly loaded object sections or those object sections of the model object that are intended to be movable or deformable can be designed with curves of the space-filling curves with a small local curve width or Layer width and therefore with little material application with larger part height or Layer height of the substructures or Elevation layers are carried out.

Finally, in step -k-, the N (N 2 to n) height layers of the model object are applied layer by layer using a manufacturing device for additive manufacturing, preferably with a 3D printing device, in order to manufacture the model object.

With the method according to the invention, starting from a template object, a model object is created as a workpiece or as the end product of Method obtained, wherein the model object was manufactured with an additive manufacturing device, preferably with a 3D printing device. The manufacturing data required for additive manufacturing is determined in an optimized virtual data model, with space-filling fractal curves optimized for modeling the virtual data model being adapted in sections to the respective local load requirements of the individual virtual object sections of the model object.

Model objects or Components are manufactured that are particularly flexible to specific, desired or specified load scenarios of the model object are individually adapted.

The position information used below of template objects and/or model objects as well as their components, such as the terms "top", "bottom", "above", "below", "front", "back", "side", " inside", "outside", "in the axial direction", "in the radial direction" and the like, essentially serve to better understand the invention, especially in connection with the following drawings. The position information used can possibly refer to specific positions of the method according to the invention or refer to individual views in the figures. In any case, such position information is familiar to those skilled in the art, but does not limit the present invention.

In a preferred variant of the method according to the invention, in step -h-, at least one further parameter can be selected from the group comprising: local material density, local material fill rate, local extrusion width, local material selection. The local material density parameter can be selected from 0% to 100%, where 0% material density represents a cavity and 100% material density represents a solid body or a solid material is specified in the relevant virtual object section. The choice of the local material density is therefore an important parameter, especially for modeling a porous model body. The local material density is always less than or equal to the local material filling rate. The material density depends on the material used and can be influenced, for example, by inclusions of air and/or moisture. In addition, the material density can also be influenced by the selected extrusion temperature.

Using the parameter of the local extrusion width, the component load capacity and/or component mobility of the respective object section of the model object can be adjusted. The parameter of the local extrusion width thus represents the reaction of the model object to different load cases. For components or For component sections that are intended to be more movable under load, the largest possible fractal dimension level, preferably from 3 to 6, and a small extrusion width, preferably from 0.05 mm to 1.2 mm, are selected in the virtual data model of the model object for the corresponding virtual object section . The choice of a small extrusion width for the production of movable component sections of the model object means that the flexibility of the filling material used or The printing material from which the model object is made can be better utilized.

Conversely, to model rigid component sections of the model object, the highest possible extrusion width is selected.

For the application in which two or more different filling materials can be used to produce the model object using the manufacturing device used, a selected space-filling curve can also be further adapted to the requirements of the respective virtual object section through suitable local material selection. It can be particularly advantageous in particular in the case of a template object with a complex geometry, the template object having, for example, internal recesses and/or sections with porous structures, in particular with graded porosity and/or graded density, if when carrying out the method according to the invention Step -c- to calculate the virtual structural model of the model object, a geometric contour model and a porosity model of the physical template object are created.

The division for calculating the virtual structural model of the model object into a geometric contour model and a porosity model of the physical template object increases the flexibility and precision when creating the virtual structural model. For example, a geometric contour model of the template object can contain smooth, pore-free external surfaces of the template object, which are transferred as smooth, pore-free external surfaces into the optimized virtual data model of the model object. Internal recesses and/or sections with porous structures, in particular with graded porosity and/or graded density, which may be important for the functionality of the template object and/or the model object, can thus be used to create the optimized virtual data model of the model object using the porosity model be transmitted directly. This means that model objects can be manufactured that have, for example, smooth, pore-free external surfaces and internal porous structures. Likewise, in this process variant, porous model objects, in which the outer surfaces are also provided with pores, can be recreated with particular detail from corresponding porous template objects. For example, sponge-like workpieces made of sintered metal can serve as template objects for carrying out the method according to the invention in order to produce corresponding model objects with comparable or improved strength properties compared to the template object.

It may be expedient if, in a variant of the method according to the invention, in step -f- the virtual data model of the model object is divided into at least two within the Object sections lying on the model object with different

Component load capacity and/or component mobility is divided.

Advantageously, with this method variant, only internal object sections of the model object are adapted to the respective strength requirements through appropriate selection of fractal space curves.

With a method according to the invention, the virtual data model of the model object can be adapted particularly precisely to different requirements with regard to the component load capacity and/or component mobility if, in step -f-, the virtual data model of the model object is divided using a finite element analysis, wherein the virtual data model is divided into a large number of object sections, preferably into a multiplicity of object sections arranged in a grid shape with essentially the same component volume, wherein a component calculation of the component load capacity and / or component mobility is carried out at nodes between adjacent object sections.

Using a finite element analysis, components to be analyzed are divided into small virtual object sections, preferably using a grid or Grid with the same pitch is superimposed on the component to be examined for subdivision. In this way, small cube-shaped object sections, each with the same volume, are preferably selected as the calculation grid (English: "grid"), with the respective component calculation taking place at the nodes of adjacent object sections. Depending on the selected grid size or selected volume of the cube-shaped virtual object sections The calculation accuracy of the finite element analysis can be adapted to the respective requirements of the accuracy of the virtual data model of the model object. As already mentioned before, it is also conceivable to choose the calculation grid with such a small step size that each coordinate point or each Voxel corresponds to its own cube-shaped virtual object section. With a suitable objective function, finite element analysis can be used to determine particularly precisely in which virtual object section, for example, a higher local material filling rate is appropriate when producing a space-filling curve in this object section. For example, with an average global fill rate of 20% in individual virtual object sections, it may be expedient to select a higher local material fill rate, for example of 50%.

According to a further embodiment variant, a method according to the invention can be adapted particularly flexibly to different requirements with regard to the component load capacity and/or component mobility if, in step -g-, at least a first fractal curve type of a first space-filling curve for at least a first virtual object section and at least one of the first fractal curve type of different, second fractal curve type of a second space-filling curve can be selected for at least one second virtual object section that is different from the first virtual object section.

By suitably adapting the individual curve profiles in step -h- and/or step -i-, it is possible to match the individual curve profile of a first fractal curve type of a first space-filling curve, possibly with a first curve width, in a first virtual object section to the individual curve profile of a second fractal Curve type of a second space-filling curve, if necessary with a second curve width in a second virtual object section, which, for example, directly adjoins the first virtual object section, whereby discontinuities in the transition area of the two curve courses between the two adjacent object sections are avoided. The associated calculation data of the adapted curves are stored in the optimized virtual data model.

In a method according to the invention, in step -g-, at least one fractal curve type of a space-filling curve can be selected particularly flexibly from the group comprising: Hilbert 2D, Hilbert 3D, Hilbert b-Spline, Lebesgue, Lebesgue b-Spline, Koch, H-Tree, Peano 2D, Peano 3D, Peano b-Spline, Gosper, Sierpinski.

In general, the aforementioned fractal curve types are referred to as space-filling curves. Strictly speaking, such curves are only “space-filling” if their fractal dimension or fractal curve degree is infinite. Accordingly, the fractal curve types used here with a fractal dimension, for example from 2 to 6, are also referred to as “pseudo-space-filling curves”.

Depending on the chosen or given the type of load for which the model object is to be optimized, it has been shown in our own preliminary work that from the aforementioned selection of different fractal curve types, individual curve types are particularly well suited for adapting the component to specific load cases.

In order to simplify the selection of the fractal curve types that are more suitable depending on the type of load, it may be useful to compare comparative values, for example in tabular form, based on calculation results.

The dimensionless standardized error values noted in the following table depending on the type of load were obtained as follows:

For this purpose, physical three-dimensional test objects were produced, each with the same external dimensions of 80 mm x 30 mm x 30 mm, for example made of plastic. For these test objects, however, the filling rates of the space-filling curves were varied and test objects were made with different filling rates of 20%, 30% and 40%. Strain gauges were then attached to the test objects to detect any distortions or To be able to measure tensions in the material. These prepared test objects were then each subjected to known, predetermined loading forces and subjected to the usual types of loading - i.e. tension, compression, shear, torsion and bending. An appropriate measuring device was used for the examined Test objects recorded the deflections of the material for the individual load cases.

Since the absolute value of the material deflections is irrelevant for further calculations, the measurement results obtained were “normalized” to simplify further calculation. For this purpose, the individual measurement results were compared with one another. The “normalized” values obtained in this way are between -1 and +1. A standardized value of -1 means that a test object with the respective selected filling rate of the space-filling curves deforms very strongly due to the respective specified load. Conversely, a standardized value of +1 means that the respective test object with the respective selected filling rate of the space-filling curves hardly deforms due to the specified load. Due to the standardization step, the influence of the material selection of the test objects examined is also eliminated or reduced. relativized.

The following table values provide assistance in selecting the appropriate curve type depending on the type of load and the desired load scenario.

Table: standardized error values (dimensionless) depending on the type of load Negative normalized values indicate that space-filling curves can be generated with the respective curve type, which enable high deformation of the corresponding object section under the respective type of load. For example, for the production of an object section of a model object that is particularly deformable under tensile force, it may be advantageous to choose space-filling curves according to the Gosper curve type with a standardized tensile value of -0.9. Conversely, it can be useful, for example, to produce something that is as rigid or as rigid as possible under tensile force. non-deformable object section of a model object to select space-filling curves according to the Sierpinski curve type with a standardized tensile value of +0.9.

In order to avoid possible sources of error, it is advisable to use materials for the production of the test objects to be examined that will later be used in the additive manufacturing step, preferably in 3D printing, for the production of the corresponding model object.

In a further advantageous embodiment variant of the method according to the invention, which enables a particularly flexible adaptation of the individual curve profiles to the respective local requirements for component load capacity and/or component mobility, at least two individual curve profiles can be created in step -g- and in step -h- different space-filling fractal curves can be defined within one and the same virtual object section of the virtual data model.

A method according to the invention can be used in a particularly versatile manner if, in step -h-, a filling material is selected in sections in order to adapt at least one individual curve profile and at least one individual curve width of the selected at least one selected fractal curve type of the space-filling curve to the respective virtual object section, whereby a first filling material along a first curve section of the individual curve profile and a first filler material along a second curve section of the individual curve profile Filling material different, second filling material is selected. In this variant of the invention, different material properties of the different filling materials such as density, porosity, temperature resistance and the like as well as different strength properties such as tensile strength, modulus of elasticity and the like can be used for optimized strength adjustment of the component load capacity and/or component mobility of the model object. For example, object sections of the model object that are subject to higher mechanical loads can be produced from a first filling material that is of higher mechanical strength and of higher quality. Less heavily loaded object sections of the model object can, for example, be made from a second, cheaper filling material.

A method according to the invention can be carried out particularly flexibly, in which a filler material, preferably a first filler material and/or a second filler material, is applied in layers with a locally variably adjustable filler material width by means of the additive manufacturing device, with a local filler material width of the filler material, preferably the selected one first filling material and / or the selected second filling material, in a coordinate point of the model object corresponds to the curve width stored in the optimized virtual data model for this coordinate point or for a partial structure corresponding to this coordinate point. Reference is made to the previously mentioned advantages of a locally variably adjustable filling material width and the use of different filling materials for local strength optimization of object sections of the model object.

In order to be able to produce particularly precise model objects using the method according to the invention, which if possible no longer need to be reworked, it can be advantageous, according to a method variant, if in step -j - when dividing the optimized three-dimensional virtual data model into each individual substructure of the optimized virtual Data model alignment marks for the additive manufacturing of the corresponding ones Elevation layer of the model object can be specified, where in step -k- the N (N

2 to n) sequentially stacked height layers of the model object can be adjusted relative to one another without any offset during layer-by-layer application using the alignment marks stored in the individual substructures.

As part of the invention, a control according to the invention for a manufacturing device for additive manufacturing, in particular for 3D printing, is also specified, the control being set up to carry out the following method steps:

A. ) Computer-aided calculation of a virtual structural model of a three-dimensional model object depending on provided topography data of a template object;

B. ) Computer-aided calculation of a virtual

Strength model of the three-dimensional model object depending on the provided material characteristics of the template object, whereby strength data on the component load capacity and / or component mobility of the model object are obtained;

C. ) Computer-aided modeling of the virtual structural model and the virtual strength model into a three-dimensional virtual data model of the model object;

D. ) Computer-aided subdivision of the virtual data model of the

Model objects into at least two virtual object sections with different component load capacity and/or component mobility;

E. ) Select at least one fractal curve type

Space-filling curve with a fractal degree of dimension for each of the at least two virtual object sections of the virtual data model, wherein the at least one fractal curve type and / or the fractal degree of dimension for the respective virtual object section of the virtual data model based on strength data on component load capacity stored in the virtual data model and/or component mobility is selected or become;

F. ) Adjusting at least one individual curve profile and at least one individual curve width of the selected at least one fractal curve type of the space-filling curve within the respective virtual object section for each the at least two virtual object sections of the virtual data model based on strength data stored in the virtual data model for component load capacity and/or component mobility;

G. ) If necessary, repeat step E. ) for selecting at least one fractal curve type of a space-filling curve with a fractal degree of dimension for one or more virtual object sections of the virtual data model and / or repeating step F. ) for adapting the respective individual curve profile with individual curve width of the at least one selected space-filling curve for one or more virtual object sections of the virtual data model, until the curve profiles of space-filling curves for all virtual object sections of the virtual data model correspond to strength data on component load capacity stored in the virtual data model and/or component mobility are adapted and a three-dimensional optimized virtual data model is obtained, which includes optimized virtual data model coordinate points for the additive manufacturing of the model object;

H . ) Computer-aided division of a total height of the optimized three-dimensional virtual data model into a number N (N

2 to n) is selected so that each one of the N (N

2 to n) height layers each have an individual partial height adapted to the component load capacity and/or component mobility of the respective object section, whereby the sum of the N (N 2 to n) partial heights of the individual height layers corresponds to the total height of the optimized three-dimensional virtual data model; I. ) layer-by-layer application of the N (N 2 to n) height layers of the model object, stacked sequentially on top of each other, in order to manufacture the model object.

In a particularly versatile development of the control according to the invention, the control in step I. ) be set up to control the manufacturing device for additive manufacturing, in particular for 3D printing, in such a way that a filler material, preferably a first filler material and/or a second filler material, is applied in layers with a locally variably adjustable filler material width, wherein a local filler material width of the Filling material, preferably the selected first filling material and / or the selected second filling material, in a coordinate point of the model object corresponds to the curve width stored in the optimized virtual data model for this coordinate point or the stored curve width for a substructure corresponding to this coordinate point.

The manufacturing device for the additive manufacturing of a model object, with which the control according to the invention corresponds or is expediently. which is controlled by the control according to the invention, equipped with at least one print head which is used for the application of filling material with an adaptive layer width or Filling material width is suitable and with which filling curves with different curve widths can be printed. In the preferred embodiment with a manufacturing device that is suitable for manufacturing a model object from two or more different filling materials, each individual filling material is preferably assigned its own print head with an adaptive layer width or locally adjustable width of the respective filling material application is provided.

Model objects can be manufactured particularly precisely if, in a further variant, the control according to the invention is used in step H. ) is set up to assign alignment marks for additive manufacturing to the corresponding height layer of the model object when dividing the optimized three-dimensional virtual data model in each individual substructure of the optimized virtual data model specify, where in step I. ) the N (N

The advantages and advantageous effects of such a control according to the invention, which is suitable for controlling and carrying out the method described at the beginning, correspond correspondingly to the previously mentioned advantages of the method according to the invention. Reference is therefore made at this point to the comments on the advantageous method.

Furthermore, within the scope of the invention, a manufacturing device for additive manufacturing, in particular for 3D printing, is specified, the manufacturing device comprising a control according to the invention.

Such a manufacturing device can be particularly advantageously set up to carry out a method according to the invention.

The advantages and advantageous effects of such a manufacturing device for additive manufacturing, in particular a 3D printing device, which includes a control according to the invention and which is suitable for controlling and carrying out the method according to the invention described at the outset, correspond correspondingly to the advantages of the method according to the invention mentioned above. Reference is therefore also made to the explanations of the advantageous method with regard to the advantageous manufacturing device.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail using exemplary embodiments. The schematic drawings are exemplary and are intended to explain the idea of the invention, but in no way represent it in a restrictive or even conclusive manner.

Show: Fig. 1 an isometric view of a three-dimensional template object;

Fig. 2 a two-dimensional representation of fractal curve progressions using the example of a Koch curve, with views a) to d) each showing Koch curves with different degrees of fractal dimension;

Fig. 3 a two-dimensional representation of fractal curves using the example of a Hilbert curve, with views a) to d) each showing Hilbert curves with different degrees of fractal dimension;

Fig. 4 to Fig. 7, each in isometric views, a virtual structural model of the one shown in Fig. 1 illustrated template object, in each case a curve of a fractal Hilbert 3D curve, each with a different degree of fractal dimension, is drawn as a space-filling curve within the virtual structural model;

Fig. 8 a two-dimensional representation of a fractal curve using the example of a Hilbert b-spline curve;

Fig. 9 is an isometric view of a virtual structural model of the one shown in FIG. 1 illustrated template object, whereby a curve of a fractal Hilbert b-spline 3D curve is drawn as a space-filling curve within the virtual structural model;

Fig. 10 to Fig. 12 each in isometric views of a virtual strength model of the one shown in Fig. 1 illustrated template object, whereby different strength data for the component load capacity are calculated using a fractal space-filling curve of the Hilbert 3D type;

Fig. 13 is a top view of a virtual structural model of the one shown in FIG. 1 shown three-dimensional template object;

Fig. 14 is a top view of a virtual data model based on the one shown in FIG. 13 shown structural model, divided into virtual object sections with different component loads, the strength data for the component load being obtained from a previously calculated virtual strength model;

Fig. 15 is a top view of the one shown in FIG. 14 shown virtual data model with a first fractal space-filling curve of the Pseudo-Hilbert type after grid-like division into virtual object sections of the same size;

Fig. 16 is a top view of the one shown in FIG. 15 shown virtual data model after overlay with the ones in Fig. 14 shown strength data for different component loads;

Fig. 17 a top view of an optimized virtual data model with curve progressions of fractal space-filling curves, which are already adapted to the strength data for component load capacity stored in the virtual data model;

Fig. 18 an isometric view of the optimized virtual data model for producing a three-dimensional model object based on the one shown in FIG. 1 shown template object;

Fig. 19 a two-dimensional representation of a fractal curve using the example of a Hilbert curve in a first virtual object section, which is connected to an H-tree curve in a second virtual object section;

Fig. 20 a two-dimensional representation of a fractal curve using the example of a Hilbert curve with different curve widths in sections;

Fig. 21 a two-dimensional representation of a fractal curve using the example of a Hilbert curve with different curve widths in sections and with different fractal dimensions; 22 shows a sectional view from above of the model object produced during the 3D printing process;

Fig. 23 is a top view of a first height layer of the model object shown in Fig. 22;

24 shows a top view of a first partial structure of an optimized virtual data model of a further three-dimensional model body;

25 shows a top view of a further, second partial structure according to the optimized virtual data model of the model body shown in FIG. 24;

26 is an isometric view obliquely from above according to the optimized virtual data model of the three-dimensional model body shown in FIGS. 24 and 25;

27 is a side view of the division of the optimized virtual data model of the three-dimensional model body shown in FIG. 26 into substructures of the data model, which substructures correspond to individual height layers during the production of the model object.

WAYS OF CARRYING OUT THE INVENTION

Fig. 1 shows an isometric view of a physical three-dimensional template object 10, here for example a cube-shaped template object 10, with topography data 11 or geometry data of the template object 10 such as the structure and dimensions of the outer surfaces 12 of the template object 10 being recorded for carrying out the method according to the invention. This corresponds to the first method step -a-, in which topography data 11 of the template object 10 such as the information on the width B.10, the height H.10 and the length L.10 of the template object 10 are provided.

According to the second process step -b- are also additional

Material characteristics 15 of the template object 10 of interest, such as for example, its material properties, density, porosity and the like, as well as information data regarding the material load on the template object 10 during its use. These material characteristics 15 are advantageously already available for different internal sections 21 to 25 of the template object 10, which are each symbolized in FIG. 1 as cube-shaped sections 21 to 25 with dash-dotted contour edges.

Fig. 2 shows a two-dimensional representation of space-filling curves 60 of a fractal curve type 70 a first space-filling curve 61 with a fractal curve using the example of a first fractal curve type 71, a Koch curve, with views a) to d) each having Koch curves show different fractal dimensions D.70. In Fig. 2a) a fractal dimension D.70 of 1 is selected. The Koch curve shown in Fig. 2b) has the fractal dimension degree D.70 of 2, that in Fig. 2c) has the degree 3, and the Koch curve shown in Fig. 2d) has a fractal dimension degree D.70 of 4 on.

Fig. 3 shows a two-dimensional representation of space-filling curves 60 of a fractal curve type 70 a second space-filling curve 62 with a fractal curve using the example of a second fractal curve type 72, a Hilbert curve, with views a) to d) each having Hilbert curves show different fractal dimension degrees D.70, namely in Fig. 3a) with degree 1, in Fig. 3b) with degree 2, in Fig. 3c) with degree 3, and in Fig. 3d) a Hilbert curve a fractal dimension level D.70 of 4.

4 shows an isometric view of a virtual structural model 30 of the template object 10 illustrated in FIG. 1, which is calculated in step -c- of the method according to the invention. For the subsequent modeling of the virtual structural model 30 in method step -e-, the adaptation of a curve course of a space-filling curve 60 to the geometric conditions or outer contours of the virtual structural model 30 is already carried out here for the virtual structural model 30 began. Here, for example, the calculation of a third space-filling curve 63 with a third fractal curve type 73, namely a fractal Hilbert 3D curve, for example with a fractal dimensional degree D.70 of 1 as a space-filling curve within the virtual structural model 30, begins.

5 shows - comparable to FIG. 4 - an isometric view of a virtual structural model 30 of the template object 10 illustrated in FIG. which the virtual structural model 30 already fills more space than is the case with the Hilbert 3D curve shown in FIG. 4 with a fractal dimension level D.70 of 1.

6 shows - comparable to FIGS. 4 and 5 - an isometric view of a virtual structural model 30 of the template object 10 illustrated in FIG. Curve with a fractal dimension D.70 of 3 is drawn. This selected spatial curve fills the virtual structural model 30 even more space than is the case with the Hilbert 3D curve shown in FIG. 5 with a fractal dimension D.70 of 2.

7 also shows - comparable to FIGS. 4 to 6 - an isometric view of a virtual structural model 30 of the template object 10 illustrated in FIG -Curve with a fractal dimension D.70 of 4 is drawn. This selected spatial curve fills the virtual structural model 30 in a particularly space-filling manner and more densely than is the case with the Hilbert 3D curve shown in FIG. 6 with a fractal dimension level D.70 of 3.

Figures 4 to 7 are intended to illustrate how the curve shape of a space-filling curve 60 can be created by appropriately selecting the fractal curve type 70 and the fractal dimension D.70 can be adapted to the requirements of the respective model object. The in the previous description of Figures 4 to 7 and in the following description of Fig. 9, according to which the scheme of selecting at least one fractal curve type and the adaptation of the selected at least one fractal curve type to the local requirements of the model object is illustrated using the virtual structural model 30, only serves to simplify the representation and does not contradict the method according to the invention. In fact, the selection according to the method (according to method step -g-) takes place at least one suitable fractal curve type 70 of a space-filling curve 60 with a fractal degree of dimension D. 70 and adapting (according to method step -h-) the at least one suitable fractal curve type 70 based on a three-dimensional virtual data model 50, which was previously obtained in method step -e- by computer-assisted modeling of the virtual structural model 30 with strength data of a virtual strength model 40.

Fig. 8 shows a two-dimensional representation of a fractal curve of a further, fourth space-filling curve 64 with a fourth fractal curve type 74 using the example of a Hilbert b-spline curve with a fractal degree of dimension D. 70 out of 4.

Fig. 9 shows an isometric view of a virtual structural model 30 of the one shown in FIG. 1 illustrated template object, for example a curve of a further, fifth fractal curve type 75, a fractal Hilbert b-spline 3D curve with a fractal degree of dimension D. 70 of around 3, as a space-filling curve 65 within the virtual structural model 30 is drawn.

Fig. 10 shows an isometric view of a virtual strength model 40 of the one shown in FIG. 1 illustrated template object 10, where strength data 41 for component stress are calculated using a fractal space-filling curve 63 with a fractal curve type 73, for example a Hilbert 3D curve. Fig. 11 shows an isometric view of a virtual strength model 40 of the one shown in FIG. 1 illustrated template object 10, with 3D strength data 42 for component shear being calculated using a fractal space-filling curve 63 of the Hilbert type.

Fig. 12 shows an isometric view of a virtual strength model 40 of the one shown in FIG. 1 illustrated template object 10, with strength data 43 for component expansion being calculated using a fractal space-filling curve 63 of the Hilbert type 3D curve.

Figures 10 to 12 symbolize process step -d-.

Fig. 13 represents a top view of a virtual structural model 30 of the one shown in FIG. 1 three-dimensional template object 10 shown.

Strength data 41, 42, 43 on the component load capacity and/or component mobility of the model object 100 to be produced, which are obtained in method step -d- by calculating the virtual strength model 40, are obtained according to method step -e- by computer-assisted modeling of the virtual structural model 30 and the virtual strength model 40 combined into a three-dimensional virtual data model 50 of the model object.

Fig. 14 shows a top view of such a virtual data model 50 based on the one shown in FIG. 13 shown structural model 30. According to method step -f-, the virtual data model 50 is already divided into two virtual object sections 51, 52 with different component loads, with the strength data 41, 42, 43 for the component load being obtained from the calculated virtual strength model 40. In Fig. 14 is the upper virtual object section 51 in the picture with a comparatively increased component load, which component load F. 40 by power arrows F. 40 is symbolized. A finite element analysis is expediently used to calculate the virtual strength model 40 in order to identify those virtual object sections 51 in which, for example, due to locally increased component stress A higher material filling rate must be taken into account when producing the corresponding space-filling curves.

Fig. 15 shows a top view of the one shown in FIG. 14 shown virtual data model 50 with a fractal space-filling curve 62 with a fractal curve type 72, for example of the Hilbert type with a fractal dimension degree D. 70 of 4 after grid-shaped division into virtual object sections 53 to 55 of the same size.

Fig. 16 shows a top view of the one shown in FIG. 15 shown virtual data model 50 after superposition with the ones shown in Fig. 14 shown virtual object sections 51 and 52 with different component loads.

Fig. 17 shows a top view of an optimized virtual data model with curve progressions 80 of fractal space-filling curves, which are already adapted to the strength data 41, 42, 43 for component load capacity stored in the virtual data model. In the virtual object section 51 with increased component load, here is a curve 80 of a space-filling curve 62 with a second fractal curve type 72, for example a Hilbert curve with a fractal dimension D. 70 of 4, to the locally increased requirements for component resilience or. Component mobility of this virtual object section 51 adjusted.

In the virtual object section 52, which is to be designed for a comparatively lower component load, a different curve shape 80 of a space-filling curve 63 different from the second fractal curve type 72 is used with a third fractal curve type 73, for example a pseudo-Hilbert curve with a fractal dimension degree D . 70 of 3, selected. The two different curve types 72, 73 also differ from each other in their different curve widths 81, 82.

Fig. 18 shows an isometric view of the optimized virtual data model 90 according to method step -i- for producing a three-dimensional model object based on the one shown in FIG. 1 shown template object 10 or. based on the one before modeled virtual data model 50 of the model object to be produced.

The curve progressions 80 and the curve widths 81,82,83 of the adapted space-filling curves 60,61,62,63 - where the selected curve widths correspond to the local filling material widths 81,82,83 - are already in this optimized virtual data model 90 for all virtual object sections 51 ,52,53,54,55 of the virtual data model 50 is adapted to strength data 41,42,43 stored in the virtual data model 50 for component load capacity and/or component mobility. The component volume 59 of each virtual object section 51,52,53,54,55 is expediently chosen to be as large as possible. The three-dimensional optimized virtual data model 90 already contains coordinate points 101,102,103 for the additive manufacturing of the model object to be produced.

19 shows a two-dimensional representation of a fractal curve progression of a first space-filling curve 61 using the example of a Hilbert curve 71 in a first virtual object section 51, the first space-filling curve 61 having a second space-filling curve 62, for example of the type H-tree curve 72 in a second virtual object section 52 is connected. The two space-filling curves 61, 62 in the virtual object sections 51, 52 each have the same curve width 81. The boundary between the two virtual object sections 51 and 52 is indicated by a dash-dotted line.

Fig. 20 shows a two-dimensional representation of a fractal curve of a first space-filling curve 61 using the example of a Hilbert curve 71 with different curve widths 81, 82, 83 in sections. The fractal dimension D.70 of the Hilbert curve 71 shown here is approximately the value 3. The curve shape of the Hilbert curve 71 in the first virtual object section 51 on the left in the picture has a first, comparatively small curve width 81, which has a comparatively small local Filling material width is accompanied. In the second virtual object section 52 at the top right of the image, the curve of the Hilbert curve 71 has a second, comparatively large curve width 82. In the third virtual Object section 53 at the bottom right of the picture, the curve of the Hilbert curve 71 has a third, average curve width 83, with this average curve width 83 lying between the small curve width 81 and the large curve width 82. The boundaries between the virtual object sections 51, 52, 53 are each indicated by dash-dotted lines.

Fig. 21 shows a two-dimensional representation of a fractal curve of space-filling curves 61,62 using the example of Hilbert curves 71,72 with different curve widths 81,82,83 in sections and with different fractal dimension degrees D.70 with values of approximately 3 or of approximately 4. The curve shape of the Hilbert curve 71 in the first virtual object section 51 on the left in the image has a first, comparatively small curve width 81, which is accompanied by a comparatively small local filling material width. In the second virtual object section 52 at the top right of the image, the curve of the Hilbert curve 71 has a second, comparatively large curve width 83 or a comparatively large local filling material width. A curve width 82 at the transition between the first virtual object section 51 and the second virtual object section 52 lies between the small curve width 81 and the large curve width 83. The curve shape of the space-filling curve 61 using the example of a Hilbert curve 71 in the first and in the second virtual object section 51 .52 each has a fractal dimensionality D.70 of approximately 3.

In the third virtual object section 53 at the bottom right of the image, the curve of the Hilbert curve 72 again has a small curve width 81, this small curve width 81 being smaller than the large curve width 83 in the second virtual object section 52. A curve width 82 at the transition between the second virtual object section 52 and the third virtual object section 53 lies between the small curve width 81 and the large curve width 83. The curve shape of the space-filling curve 62 using the example of a Hilbert curve 72 has a fractal in the third virtual object section 53 Dimensional grade D.70 of approximately 4. The boundaries between the virtual object sections 51, 52, 53 are each indicated with dash-dotted lines.

22 shows a sectional view from above of the manufactured model object 100 during the 3D printing process. Coordinate points 101,102,103 of the three-dimensional optimized virtual data model 90 are manufactured into physical coordinate points 101,102,103 of the model object 100.

23 shows a top view of a first height layer 111 of the model object 100 shown in FIG to recognize.

24 shows a top view of a first partial structure 91 of an optimized virtual data model 90 of a further three-dimensional model body, which here, for example, has a rectangular base area with a centrally arranged circular recess. In this first substructure 91, an optimized curve shape of a space-filling curve 62 of a specific fractal curve type 72 can be seen. A first filling material 121 is provided as filling material 120 for producing the space-filling curve 62 in this first partial structure 91.

25 shows a top view of a further, second partial structure 92 according to the optimized virtual data model 90 of the three-dimensional model body shown in FIG. 24. Here different virtual object sections 51 to 55 can be seen with different optimized curve progressions of different space-filling curves 60 to 65, which can also differ in their fractal curve type 70 to 75 and in their curve width 81, 82, 83. The curve progressions of the space-filling curves 60 to 65 in virtual object sections 52, 53 that are subject to higher mechanical loads are intended here, for example, for production from a second, particularly robust filling material 122. The space-filling curves 60 to 65 in virtual ones with less mechanical load Object sections 54, 55 are intended for production from the first filling material 121.

26 shows an isometric view obliquely from above according to the optimized virtual data model 90 of the three-dimensional model body shown in FIGS. 24 and 25. A total height H.90 of the optimized virtual data model 90 corresponds to the total height of the model object to be produced.

27 shows a side view of the division of the optimized virtual data model 90 of the three-dimensional model body shown in FIG correspond to individual height layers 111,112,113 during the additive manufacturing of the model object 100 (in Fig. 27 on the right in the picture).

According to method step -j-, a total height H.90 of the optimized three-dimensional virtual data model 90 is divided into a number N (N

2 to n) of sequentially stacked height layers 111,112,113 of the model object 100, each of the N (N

2 to n) height layers 111,112,113 of the model object 100 corresponds to a single substructure 91,92,93 of the optimized virtual data model 90 and includes coordinate points 101,102,103 for the additive manufacturing of the corresponding height layer 111,112,113 of the model object 100. The number N is chosen as an integer which is greater than or equal to the number 2, and where the number N (N

2 to n) is selected so that each of the N (N

2 to n) height layers 111,112,113 each have an individual partial height H. Ill, H.112, H.113 adapted to the component load capacity and/or component mobility of the respective object section 51,52,53. The sum of the N (N

2 to n) Partial heights H. Ill, H.112, H.113 of the individual height layers 111, 112, 113 correspond to the total height H.90 of the optimized three-dimensional virtual data model 90.

In Fig. 27 on the right of the picture, the process step -k- is schematically illustrated, with a layer-by-layer application of the N (N 2 to n) sequentially stacked height layers 111, 112, 113 of the model object 100 by means of a manufacturing device for additive manufacturing, here for example with a 3D printing device, with which the model object 100 is manufactured.

It is particularly advantageous if, as illustrated in FIG. where the N (N

2 to n) sequentially stacked height layers 111, 112, 113 of the model object 100 can be adjusted relative to one another with as little offset as possible during layer-by-layer application using the alignment marks 109 stored in the individual substructures 91, 92, 93. A complex post-processing of the manufactured model object 100, for example by smoothing the surfaces, can therefore be omitted.

A model object 100 produced in this way using a method according to the invention is optimized with regard to its strength requirements and can then immediately be used for the respective application.

REFERENCE SYMBOL LIST

10 three-dimensional template object

11 Topography data or geometry data of the template object

12 Outer surface of the template object

15 material characteristics of the template object

B.10 Width of the template object

H.10 Height of the template object

L.10 Length of the template object

21 (first, inner) section of the template object

22 (second, internal) section of the template object

23,24,25 (further or nth) section of the template object

30 virtual structural model b.30 width of the virtual structural model h.30 height of the virtual structural model

1.30 Length of the virtual structural model

40 virtual strength model

41 strength data for component tension

42 strength data for component shear

43 strength data for component elongation

F.40 Component load (force arrow)

50 three-dimensional virtual data model

51 (first) virtual object section

52 (second) virtual object section

53,54,55 (further or nth) virtual object section

59 component volume of a virtual object section

60 Space-filling curve

61 (first) space-filling curve

62 (second) space-filling curve

63,64,65 (further or nth) space-filling curve

70 fractal curve type

71 (first) fractal curve type

72 (second) fractal curve type

73,74,75 (further or nth) fractal curve type

D.70 fractal dimension level

80 curve course

81,82,83 curve width; local filling material width REFERENCE SYMBOL LIST (continued)

90 optimized three-dimensional virtual data model

91 (first) substructure of the data model

92 (second) substructure of the data model

93 (further or Nth) substructure of the data model

H.90 Total height of the optimized virtual data model

100 three-dimensional model object

101 (first) coordinate point of the model object

102 (second) coordinate point of the model object

103 (additional) coordinate point of the model object

109 alignment mark

111 (first) elevation layer of the model object

112 (second) elevation layer of the model object

113 (additional or Nth) elevation layer of the model object

H.lll Partial height of a (first) height layer of the model object

H.112 Partial height of a (second) height layer of the model object

H.113 Partial height of a (further) elevation layer of the model object

120 Fill material of the model object

121 first filling material

122 second filling material

Claims

EXPECTATIONS . Method for additive manufacturing, in particular for 3D printing, the method comprising the following steps:

-a- Providing topography data (11) of a physical three-dimensional template object (10);

-b- Providing material characteristics (15) of the

template object (10) ;

— c~ Computer-aided calculation of a virtual

Structural model (30) of a three-dimensional model object (100) depending on the topography data (11) of the template object (10) provided in step -a-;

-d- Computer-aided calculation of a virtual

Strength model (40) of the three-dimensional model object (100) as a function of the material characteristics (15) of the template object (10) provided in step -b-, with strength data (41,42,43) relating to the component load capacity and/or component mobility of the model object (100) be obtained;

-e- Computer-aided modeling of the virtual

Structural model (30) and the virtual strength model (40) to a three-dimensional virtual data model (50) of the model object (100);

-f- Computer-assisted subdivision of the virtual

Data model (50) of the model object (100) into at least two virtual object sections (51,52,53) with different component load capacity and/or component mobility;

-g- Select at least one fractal curve type

(70,71,72,73) a space-filling curve (60,61,62,63) with a fractal degree of dimension (D.70) for each of the at least two virtual object sections (51,52,53) of the virtual data model (50) , wherein the at least one fractal curve type (70,71,72,73) and/or the fractal dimension level (D.70) for the respective virtual object section (51,52,53) of the virtual data model (50) based on in the virtual data model (50) stored strength data (41,42,43) for component load capacity and/or component mobility is or are selected; -h- Adjust at least one individual curve profile

(80) and at least one individual curve width (81,82,83) of the selected at least one fractal curve type (70,71,72,73) of the space-filling curve

(60,61,62,63) within the respective virtual object section (51,52,53) for each of the at least two virtual object sections (51,52,53) of the virtual data model (50) based on those stored in the virtual data model (50). Strength data (41,42,43) on component load capacity and/or component mobility;

-i- If necessary, repeat step -g- to select at least one fractal curve type (70) of a space-filling curve with a fractal degree of dimension (D.70) for one or more virtual object sections (51,52,53) of the virtual data model (50) and/or repeating step -h- to adapt the respective individual curve profile (80) with individual curve width (81,82,83) of the at least one selected space-filling curve

(60,61,62,63) for one or more virtual object sections (51,52,53) of the virtual data model (50) until the curves (80) of space-filling curves

(60,61,62,63) for all virtual object sections (51,52,53) of the virtual data model (50) are adapted to strength data (41,42,43) stored in the virtual data model (50) for component load capacity and / or component mobility and a three-dimensional optimized virtual data model (90) is obtained, which comprises optimized virtual data model (90) coordinate points (101,102,103) for the additive manufacturing of the model object (100);

-j- Computer-aided division of a total height (H.90) of the optimized three-dimensional virtual data model (90) into a number N (N

2 to n) of sequentially stacked height layers (111,112,113) of the model object (100), each of the N (N

2 to n) height layers (111,112,113) of the model object (100) corresponds to a single substructure (91,92,93) of the optimized virtual data model (90) and coordinate points (101,102,103) for the additive manufacturing of the corresponding Elevation layer (111,112,113) of the model object (100), where the number N is an integer which is greater than or equal to the number 2, and where the number N (N

2 to n) is selected so that each of the N (N

2 to n) height layers (111,112,113) each have an individual partial height (H. Ill, H.112, H.113) adapted to the component load capacity and / or component mobility of the respective object section (51,52,53), whereby the sum of N (N

2 to n) partial heights (H. Ill, H.112, H.113) of the individual height layers (111,112,113) correspond to the total height (H.90) of the optimized three-dimensional virtual data model (90);

-k- layer-by-layer orders of the N (N

2 to n) sequentially stacked height layers (111,112,113) of the model object (100) using a manufacturing device for additive manufacturing, preferably with a 3D printing device, in order to manufacture the model object (100). . Method according to claim 1, characterized in that in step -h- for adapting at least one individual curve profile (80) and at least one individual curve width (81,82,83) of the at least one fractal curve type (70,71,72,73). Space-filling curve (60,61,62,63) to the respective virtual object section (51,52,53) at least one further parameter is selected from the group comprising: local material density, local material filling rate, local extrusion width, local material selection (120,121,122) . . Method according to claim 1 or 2, characterized in that in step -c- for calculating the virtual structural model (30) of the model object (100), a geometric contour model and a porosity model of the physical template object (10) are produced. . Method according to one of claims 1 to 3, characterized in that in step -f- the virtual data model (50) of the model object (100) is divided into at least two object sections (51, 52, 53) located within the model object (100). different component load capacities and/or

Component mobility is divided. Method according to one of claims 1 to 4, characterized in that in step -f- the division of the virtual data model (50) of the model object (100) is carried out by means of a finite element analysis, the virtual data model (50) being divided into one A plurality of object sections (51,52,53,54,55), preferably divided into a plurality of object sections (51,52,53,54,55) arranged in a grid shape with essentially the same component volume (59), wherein a component calculation of the Component load capacity and/or component mobility is carried out at junction points between adjacent object sections (51,52,53). Method according to one of claims 1 to 5, characterized in that in step -g- at least a first fractal curve type (71,72) of a first space-filling curve (61,62) for at least a first virtual object section (51) and at least one of first fractal curve type (71,72) different, second fractal curve type (73,74) of a second space-filling curve (63,64) can be selected for at least one second virtual object section (52) that is different from the first virtual object section (51). Method according to one of claims 1 to 6, characterized in that in step -g- at least one fractal curve type (70,71,72,73,74,75) of a space-filling curve (60,61,62,63,64,65 ) is selected from the group comprising: Hilbert 2D, Hilbert 3D, Hilbert b-Spline, Lebesgue, Lebesgue b-Spline, Koch, H-Tree, Peano 2D, Peano 3D, Peano b-Spline, Gosper, Sierpinski. Method according to one of claims 1 to 7, characterized in that in step -g- and in step -h- at least two individual curve profiles (80) of two different space-filling curves (60,61,62,63,64,65) within one and the same virtual object section (51) of the virtual data model (50). Method according to one of claims 1 to 8, characterized in that in step -h- for adapting at least one individual curve profile (80) and at least one individual curve width (81,82) of the selected at least one selected fractal curve type (70,71,72 ,73) of the space-filling curve (60,61,62,63) on the respective virtual object section (51,52,53) a filling material (120,121,122) is selected in sections, a first filling material being along a first curve section of the individual curve profile (80). (121) and along a second curve section of the individual curve profile (80) a second filling material (122) that is different from the first filling material (121) is selected. Method according to claim 9, characterized in that by means of the device for additive manufacturing a filler material (120), preferably a first filler material (121) and/or a second filler material (122), in layers with a locally variably adjustable filler material width (81,82,83 ) is applied, wherein a local filling material width (81,82,83) of the filling material (120), preferably of the selected first filling material (121) and / or the selected second filling material (122), in a coordinate point (101) of the model object (100 ) corresponds to the curve width (81,82,83) stored in the optimized virtual data model (90) for this coordinate point (101) or to the curve width (81,82,83) stored for a substructure (91) corresponding to this coordinate point (101). Method according to one of claims 1 to 10, characterized in that in step -j- when dividing the optimized three-dimensional virtual data model (90) in each individual substructure (91,92,93) of the optimized virtual data model (90) alignment marks (109) for the additive manufacturing of the corresponding height layer (111,112,113) of the model object (100) are specified, wherein in step -k- the N (N 2 to n) sequentially stacked height layers (111,112,113) of the model object (100) during the layer-by-layer application based on the in the individual sub-structures (91, 92,93) stored alignment marks (109) can be adjusted relative to each other without any offset. . Control for a manufacturing device for additive manufacturing, in particular for 3D printing, characterized in that the control is set up to carry out the following process steps:

A.) Computer-aided calculation of a virtual

Structural model (30) of a three-dimensional model object (100) depending on provided topography data (11) of a template object (10);

B.) Computer-aided calculation of a virtual

Strength model (40) of the three-dimensional model object (100) as a function of provided material characteristics (15) of the template object (10), whereby strength data (41,42,43) on the component load capacity and/or component mobility of the model object (100) are obtained;

C.) Computer-aided modeling of the virtual

D.) Computer-aided subdivision of the virtual

E.) Select at least one fractal curve type

(70,71,72,73) a space-filling curve (60,61,62,63) with a fractal degree of dimension (D.70) for each of the at least two virtual object sections (51,52,53) of the virtual data model (50) , wherein the at least one fractal curve type (70,71,72,73) and/or the fractal dimension level (D.70) for the respective virtual object section (51,52,53) of the virtual data model (50) based on in the virtual Data model (50) stored strength data (41,42,43) for component load capacity and/or component mobility is or are selected;

F.) Adjusting at least one individual curve profile

(80) and at least one individual curve width (81,82,83) of the selected at least one fractal curve type (70,71,72,73) of the space-filling curve (60,61,62,63) within the respective virtual object section (51, 52,53) for each of the at least two virtual object sections (51,52,53) of the virtual data model (50) based on strength data (41,42,43) stored in the virtual data model (50) regarding component load capacity and/or component mobility;

G.) If necessary, repeat step E.) to select at least one fractal curve type (70) of a space-filling curve with a fractal degree of dimension (D.70) for one or more virtual object sections (51,52,53) of the virtual data model (50) and/or repeating step F.) to adapt the respective individual curve profile (80) with individual curve width (81,82,83) of the at least one selected space-filling curve (60,61,62,63) for one or more virtual object sections ( 51,52,53) of the virtual data model (50) until the curve progressions (80) of space-filling curves (60,61,62,63) for all virtual object sections (51,52,53) of the virtual data model (50) are at im strength data (41,42,43) stored in the virtual data model (50) are adapted to the component load capacity and/or component mobility and a three-dimensional optimized virtual data model (90) is obtained, which has optimized virtual data model (90) coordinate points (101,102,103) for the additive manufacturing of the Model object (100);

H.) Computer-aided division of a total height (H.90) of the optimized three-dimensional virtual data model (90) into a number N (N 2 to n) of sequentially stacked height layers (111,112,113) of the model object (100), each of the N (N 2 to n) height layers (111,112,113) of the model object (100) of a single one Partial structure (91,92,93) of the optimized virtual data model (90) corresponds and includes coordinate points (101,102,103) for the additive manufacturing of the corresponding height layer (111,112,113) of the model object (100), where the number N is an integer which is greater than or is equal to the number 2, and where the number N (N

2 to n) is selected so that each of the N (N

2 to n) height layers (111,112,113) each have an individual partial height (H. Ill, H.112, H.113) adapted to the component load capacity and/or component mobility of the respective object section (51,52,53), whereby the sum of N (N

I.) layer-by-layer application of the N (N

2 to n) sequentially stacked height layers (111,112,113) of the model object (100) in order to produce the model object (100). . Control according to claim 12, characterized in that the control in step I.) is set up to control the manufacturing device for additive manufacturing, in particular for 3D printing, such that a filling material (120), preferably a first filling material (121) and/or a second filler material (122), is applied in layers with a locally variably adjustable filler material width, wherein a local filler material width of the filler material (120), preferably of the selected first filler material (121) and/or the selected second filler material (122), in one Coordinate point (101) of the model object (100) of the curve width (81,82,83) stored in the optimized virtual data model (90) for this coordinate point (101) or the stored curve width (81,82,83) for one with this coordinate point (101 ) corresponding substructure (91). . Control according to claim 12 or 13, characterized in that the control in step H.) is set up to divide the optimized three-dimensional virtual Data model (90) in each individual substructure (91,92,93) of the optimized virtual data model (90) to specify alignment marks (109) for the additive manufacturing of the corresponding height layer (111,112,113) of the model object (100), in step I.) the N (N

2 to n) sequentially stacked height layers (111,112,113) of the model object (100) can be adjusted relative to one another without any offset during the layer-by-layer application using the alignment marks (109) stored in the individual substructures (91,92,93). Manufacturing device for additive manufacturing, in particular for 3D printing, comprising a control according to one of claims 12 to 14. Manufacturing device according to claim 15, characterized in that the manufacturing device is set up to carry out a method according to one of claims 1 to 11.