DE102022203819A1 - Additive manufacturing process for producing components using melt layering of filament material - Google Patents

Abstract

Additive manufacturing method for producing components (10) by means of melt layering of filament material (15), comprising the steps: moving a print head (2) along a predetermined trajectory (20) relative to a platform (3) which has several independently heatable platform segments (31, 32, 33, 34), wherein the trajectory (20) corresponds to a projection of a trajectory of the print head (2) in a plane of the platform (3), depositing melted filament material (15) onto the platform (3 ) or on filament material (16) already placed on the platform (3) by means of the print head (2) while moving along the trajectory (20), and controlled heating of one or more of the platform segments (31, 32, 33, 34 ) depending on the trajectory (20).

Description

The present invention relates to an additive manufacturing process for producing components by means of melt layering of filament material. The invention further relates to a device for additive manufacturing using melt deposition.

Methods and devices for additive manufacturing by means of melt layering of filament material, which often consists of plastic, are known. Such a process is also known as fused deposition modeling (FDM for short) or 3D printing. The filament material is usually melted in a print head by heating and the softened or flowable filament material is discharged from an opening and placed in a caterpillar shape on a production bed or on an existing part of a component to be manufactured, where the filament material cools and solidifies. Such a production bed is often designed as a flat platform. This platform is usually heated while it is cast off. This results in high energy consumption, particularly with large platforms for the production of components with larger volumes.

It is therefore an object of the present invention to create an additive manufacturing process for producing components by means of melt layering of filament material, with which components can be manufactured in series efficiently and in an energy-saving manner. Furthermore, it is an object of the invention to provide a device for additive manufacturing by means of melt deposition, with which components can be produced in series production in an efficient and energy-saving manner.

The task is solved by a method according to claim 1, and by a device according to claim 9.

• - Bewegen eines Druckkopfes entlang einer vorgegebenen Trajektorie relativ zu einer Plattform, die mehrere unabhängig voneinander beheizbare Plattformsegmente umfasst,
• - Ablegen von geschmolzenem Filament-Material auf die Plattform oder auf bereits auf die Plattform abgelegtes Filament-Material mittels des Druckkopfes und während des Bewegens des Druckkopfes entlang der Trajektorie, und
• - gesteuertes Beheizen von einem oder mehreren der Plattformsegmente der Plattform in Abhängigkeit der Trajektorie.

Die Trajektorie entspricht dabei einer Projektion einer Bewegungsbahn des Druckkopfes relativ zur Plattform und in einer Ebene der Plattform.The additive manufacturing process according to the invention for producing components by means of melt layering of filament material comprises the following steps:

• - moving a print head along a predetermined trajectory relative to a platform that includes several independently heatable platform segments,
• - Depositing melted filament material onto the platform or onto filament material already deposited onto the platform using the print head and while moving the print head along the trajectory, and
• - controlled heating of one or more of the platform segments of the platform depending on the trajectory.

The trajectory corresponds to a projection of a movement path of the print head relative to the platform and in a plane of the platform.

In particular, the trajectory is based on predetermined manufacturing data, which define the movement of the print head during the manufacture of the components. Preferably, filament material is deposited onto the platform or onto the filament material already placed thereon at any time or alternatively along the trajectory.

In other words, the method is carried out with a segmented platform, the individual platform segments of which can be heated independently of one another. This heating is operated in a controlled manner depending on the trajectory. This means that the heating of the platform can be adapted flexibly and specifically to the production of the components. On the one hand, it can be ensured that those platform segments on which filament material is placed are specifically heated to the optimal temperature in order to ensure optimal material properties of the component to be manufactured. Furthermore, the method allows a reduction in the heating power or a switching off of the heating of platform segments on which filament material is not placed at any time during the production of the components. This makes it possible to carry out the process in a particularly energy-efficient manner. Furthermore, the targeted controllability of the heating of the platform can provide a particularly time-efficient production of the components, which means that components in series production in particular can be produced in a time-efficient and cost-effective manner.

The controlled heating is preferably carried out depending on a current position of the print head along the trajectory. This means that the individual platform segments of the platform are selectively heated depending on the position of the trajectory at which the print head is currently located. Alternatively or additionally preferably, the controlled heating is carried out depending on a movement speed of the print head along the trajectory. In particular, a current movement speed and preferably additionally a future movement speed of the print head along the trajectory are considered. For example, it can be determined exactly at what point in time the print head is at a specific position on the platform, i.e. above which platform segment. This means that the controlled heating of the individual platform segments can be carried out in a particularly targeted and simple manner in order to achieve optimal efficiency of the process.

Particularly preferably, the heating is controlled in such a way that individual platform segments, preferably each platform segment, have at least one predetermined depositing temperature within a depositing period. The deposition time period is defined starting from a start to an end of the deposition of filament material onto the corresponding platform segment. This means that the platform segment on which filament material is deposited is heated in such a way that the platform segment always has at least the predetermined depositing temperature during the entire depositing process on this platform segment. As a result, the heating of the platform can be adjusted in a particularly targeted and efficient manner in order to provide the optimal temperatures for the desired material properties of the component to be manufactured.

Preferably, the heating is controlled in such a way that individual platform segments, preferably each platform segment, have at least a predetermined keeping-warm temperature within a predetermined keeping-warm period. The keeping-warm period is temporally, in particular directly, adjacent to the putting-down period. This means that after the filament material has been placed on exactly a specific platform segment, this platform segment is kept warm at the warming temperature. This allows the hardening of the deposited filament material to be specifically influenced in order to ensure the optimal desired component properties.

The keep-warm period preferably has a duration of at least 5 seconds, preferably at least 10 seconds. More preferably, the keep-warm period has a predetermined maximum duration of, for example, 90 seconds, preferably 30 seconds, in order to enable energy-saving operation.

More preferably, the warming temperature is less than or equal to the deposition temperature. For example, the keeping temperature can be at least 20 K, preferably a maximum of 100 K, lower than the deposition temperature. Preferably, the keeping warm temperature can be kept constant during the keeping warm period. Alternatively, the keeping temperature can preferably be reduced during the keeping warm period, in particular continuously, which enables a particularly energy-saving production process.

Further preferably, the heating is controlled in such a way that the corresponding platform segment, on which the filament material is deposited during the deposition period, is heated to the predetermined deposition temperature within a predetermined preheating period. The preheating period is immediately before the depositing period. In particular, during the preheating period, the platform segment is heated in a controlled manner in such a way that this platform segment has at least the depositing temperature at the end of the preheating period, which corresponds to the beginning of the depositing period. In other words, the platform segment is heated for the duration of the preheating period before the filament material is actually deposited, so that the platform segment has the required temperature at the time when the print head first deposits part of a filament bead onto the corresponding platform segment depositing temperature. Thus, with a possible high energy efficiency of the method, it can be ensured particularly reliably that each platform segment always has the optimal temperature at the time at which the filament material is actually deposited.

The step of controlled heating preferably includes the following step: reducing a heating power for the individual platform segment, preferably for each platform segment, outside of a heating period. The heating period includes, in particular exclusively, the preheating period and the putting down period and the keeping warm period. In other words, the heating output for an individual platform segment of the platform is reduced if the deposition of the filament material onto that platform segment is more than the preheating period in the future, or more than the keeping warm period in the past. This means the process can be carried out very easily and energy-efficiently.

Particularly preferably, each platform segment is heated exclusively within the heating period, which, in particular exclusively, includes the preheating period and the depositing period and the keeping warm period. That is, outside the heating period of each platform segment, a heating output for that platform segment is reduced to zero. This enables a particularly energy-efficient process and thus cost-effective production of the components.

More preferably, the movement of the print head is carried out using a robot arm. The print head is arranged on the robot arm. For example, the robot arm can be part of an industrial robot that can be moved on multiple axes. The method is therefore particularly suitable for the production of large-volume components, which are manufactured, for example, on platforms measuring several square meters.

Furthermore, the invention leads to a device for additive manufacturing using melt deposition. The device comprises a platform with a plurality of independently heatable platform segments thereby, a print head which is set up to deposit melted filament material onto the platform, and a manipulation device which is set up to move the print head relative to the platform. In addition, the device includes a control device which is set up to carry out the additive manufacturing process described. In particular, the control device is set up to actuate the manipulation device, preferably in such a way as to move the print head along the predetermined trajectory relative to the platform. Preferably, the control device is additionally set up to operate the heating of the several platform segments in a selectively controlled manner. This makes it possible to provide a device which, with a simple structure, enables particularly time- and energy-efficient production of components by melt deposition.

The manipulation device preferably comprises a robot arm, by means of which the print head can be moved relative to the platform, preferably in multiple axes. In particular, the robot arm can be part of an industrial robot, with the print head preferably being arranged at one arm end of the robot arm.

• 1 eine vereinfachte schematische Ansicht einer Vorrichtung mittels welcher ein Verfahren gemäß einem bevorzugten Ausführungsbeispiel der Erfindung durchgeführt wird,
• 2 eine vereinfachte schematische Ansicht einer Bewegung eines Druckkopfes der Vorrichtung der 1 während einer Durchführung des erfindungsgemäßen Verfahrens, und
• 3 eine vereinfachte schematische Ansicht zeitlicher Abläufe des gesteuerten Beheizens für ein einzelnes Plattformsegment während der Durchführung des erfindungsgemäßen Verfahrens.

The invention is explained in more detail below using an exemplary embodiment. Show here:

• 1 a simplified schematic view of a device by means of which a method according to a preferred embodiment of the invention is carried out,
• 2 a simplified schematic view of a movement of a print head of the device 1 while carrying out the method according to the invention, and
• 3 a simplified schematic view of the temporal sequences of controlled heating for an individual platform segment during the implementation of the method according to the invention.

A preferred exemplary embodiment of an additive manufacturing process for producing components 10 by means of melt layering of filament material 15 is described below. The focus is on the 1 until 3 Referenced. Identical or functionally identical components are always provided with the same reference numbers.

1 shows a simplified schematic view of a device 1 by means of which the additive manufacturing process according to the invention is carried out.

The device 1 includes a manipulation device 4 with a robot arm that can be moved in several axes. A print head 2 is arranged at one end of the robot arm, by means of which melted filament material can be deposited for 3D printing of components 10.

The components 10 are produced by the print head 2 depositing the melted filament material onto a platform 3.

The platform 3 includes several platform segments 31, 32, 33, 34, which can be heated independently of one another. By heating the platform segments 31, 32, 33, 34, the cooling and solidification of the deposited filament material can be influenced in order to be able to optimally adjust the desired material properties of the components 10 to be produced.

Furthermore, the device 1 comprises a control device 5, which is set up to controllably operate the manipulation device 4, the print head 2, and the platform 3.

To produce the components 10, the print head 2 is moved relative to the platform 3 while the filament material 15 is placed on the platform 3. This is in the 2 presented in simplified schematic form. 2 shows a top view of platform 3.

Like in the 2 The platform 3 can be seen in the plane on which the filament material 15 is placed, segmented into the individual platform segments 31, 32, 33, 34. In the exemplary embodiment shown, the platform 3 is segmented into a matrix of five times five, i.e. a total of 25, platform segments 31, 32, 33, 34.

Alternatively, any segmentation of the platform 3 can be provided. For example, the platform 3 can have a total of at least four, preferably at least nine, particularly preferably a maximum of 100, individual platform segments 31, 32, 33, 34.

When producing the components 10, the print head 2 is moved along a predetermined trajectory 20 relative to the platform 3, during which movement the filament material 15 falls onto the platform 3 and/or onto filament material that has already been deposited. Material 16 is deposited. This allows the component 10 to be constructed in layers. The trajectory 20 is defined as a projection of a movement path of the print head 2 into a plane of the platform 3.

For example, the print head 3 can additionally be moved in a direction perpendicular to the platform, this movement in particular not being reflected by the trajectory 20.

When carrying out the method, the individual platform segments 31, 32, 33, 34 are heated individually in a controlled manner depending on the predetermined trajectory 20, as described in detail below.

First, a description of the controlled heating takes place based on an individual platform segment 34, namely the fourth platform segment 34, above which the print head 2 is located at the current time 65, that is, on which printing is currently taking place (cf. 2 ). In addition, attention is paid to the 3 Reference is made, which shows an exemplary timing of the controlled heating of the fourth platform segment 34 during implementation of the method.

Is shown in the 3 a total manufacturing time 50 as a timeline. The current time 65 lies within a deposition period 52, during which the filament material 15 is deposited onto the fourth platform segment 34. The deposition period 52 is limited precisely by a start 61 and an end 62 of the deposition of the filament material 15 onto the fourth platform segment 34. In particular, the beginning 61 corresponds to the point in time at which the print head 2 is moved along the trajectory 20 from another platform segment 32 to the fourth platform segment 34 (cf. 2 ). Analogously, the end 62 corresponds in particular to the point in time at which the print head 2 leaves the fourth platform segment 34 along the trajectory 20.

During the entire deposition period 52, the fourth platform segment 34 is heated in such a way that it has at least a predetermined deposition temperature. In particular, the deposition temperature is optimally adapted to the deposition and solidification of the filament material 15.

Before the depositing period, the fourth platform segment 34 is heated during a predetermined preheating period 51. The fourth platform segment 34 is heated during the preheating period 51 in such a way that it has at least the predetermined depositing temperature at the end of the preheating period 51, that is to say at the beginning 61 of the depositing period 52.

The preheating period 51 preferably has a predetermined duration, preferably at least 5 seconds, preferably at most 20 seconds. This ensures that the fourth platform segment 34 has a sufficiently high temperature at the start 61 of depositing.

The end 62 of the storage period 52 is immediately followed by a predetermined keeping-warm period 53, during which the fourth platform segment 34 is kept warm, namely at least at a predetermined keeping-warm temperature. The keeping temperature can correspond to the deposition temperature, or preferably be smaller than the deposition temperature. Particularly preferably, the keep-warm period 53 has a predetermined duration, preferably at least 5 seconds, preferably at most 60 seconds. This allows optimal solidification of the deposited filament material 16 to be ensured.

The preheating period 51 and the depositing period 52 and the keeping warm period 53 together form a heating period 55. The controlled heating of the fourth platform segment 34 is carried out in such a way that the fourth platform segment 34 is heated exclusively within the heating period 55 becomes. Alternatively, the fourth platform segment 34 can also be heated outside the heating period 55, with a heating output for the fourth platform segment 34 outside the heating period 55 being reduced, preferably by at least 50% compared to a maximum heating output within the heating period 55 This makes it possible to provide a particularly energy-efficient process.

For further explanation, a description of the controlled heating is given below 2 shown state in relation to further platform segments 31, 32, 33, 34.

This is exemplified in the 2 At the current time shown, a distinction is made between four types of platform segments: first platform segments 31, on which no filament material 15 is placed during the entire process. This means that the trajectory 20 does not run through the first platform segments 31. Second platform segments 32 are those platform segments through which the trajectory 20 runs and on which there is already deposited filament material 16, that is, on which filament material has already been deposited became. Third platform segments 33 are those platform segments through which the Trajectory 20 runs, on which there is currently no filament material 15, 16. This means that, starting from the current point in time, filament material will be deposited onto the third platform segments 33 using the print head 2 in the future. Furthermore, the fourth platform segment 34 is the one on which filament material is currently being deposited using the print head 2. This means that the print head 2 is currently above the fourth platform segment 34.

At the one in the 2 In the state shown as an example, the second platform segments 32 are therefore within the warm-keeping period 53, since filament material 16 has already been placed on the second platform segments 32. The fourth platform segment 34 is, as already described, within the deposition period 52. The third platform segments 33 are within the preheating period 53, since filament material 15 will shortly be deposited onto these third platform segments 33.

The first platform segments 31 can preferably not be heated at all during the entire process in order to provide a particularly energy-efficient process.

The method according to the invention and the device according to the invention thus allow a particularly energy-efficient and therefore cost-effective production of components 10 from filament material 15 in a simple manner. In particular, a particularly time-efficient production process can also be provided through the time-optimized heating. Overall, this enables very efficient production of components 10 in series, with optimal material properties always being provided.

Reference symbol list

1

contraption

2

Printhead

3

platform

4

Robot arm

5

Control device

10

Component

15

Filament material

16

deposited filament material

20

Trajectory

31, 32, 33, 34

Platform segments

50

Manufacturing time

51

Preheat period

52

Laying time period

53

Keep warm period

55

Heating period

61

Start of casting off

62

End of casting off

65

current point in time

Claims (10)

Additive manufacturing process for producing components (10) by means of melt layering of filament material (15), comprising the steps: - moving a print head (2) along a predetermined trajectory (20) relative to a platform (3), which comprises a plurality of independently heatable platform segments (31, 32, 33, 34), - wherein the trajectory (20) corresponds to a projection of a movement path of the print head (2) into a plane of the platform (3), - Depositing melted filament material (15) onto the platform (3) or onto filament material (16) already deposited onto the platform (3) by means of the print head (2) while moving along the trajectory (20), and - controlled heating of one or more of the platform segments (31, 32, 33, 34) depending on the trajectory (20). Additive manufacturing process Claim 1 , wherein the controlled heating is carried out depending on a current position of the print head (2) and / or a movement speed of the print head (2) along the trajectory (20). Additive manufacturing process according to one of the preceding claims, - wherein the heating is controlled in such a way that individual platform segments (31, 32, 33, 34) have at least one predetermined depositing temperature within a depositing period (52), - Wherein the depositing period (52) is defined by a start (61) and an end (62) of depositing filament material (15) onto the corresponding platform segment (31, 32, 33, 34). Additive manufacturing process according to Claim 3 , wherein the heating is controlled in such a way that individual platform segments (31, 32, 33, 34) have at least a predetermined keeping-warm temperature within a predetermined keeping-warm period (53) after the depositing period (52). Additive manufacturing process according to Claim 4 , whereby the keeping temperature is less than or equal to the storage temperature. Additive manufacturing process according to Claim 4 or 5 , wherein the heating is controlled in such a way that the corresponding platform segment (31, 32, 33, 34) is heated to the predetermined depositing temperature within a predetermined preheating period (51) before the depositing period (52). Additive manufacturing process according to Claim 6 , wherein the controlled heating includes: reducing, in particular deactivating, a heating power of the individual platform segment (31, 32, 33, 34) outside of a heating period (55), which includes the preheating period (51) and the depositing period (52 ) and the keep-warm period (53). Additive manufacturing method according to one of the preceding claims, wherein the movement of the print head (2) is carried out by means of a robot arm (4) on which the print head (2) is arranged. Device for additive manufacturing using melt deposition, comprising: - a platform (3) with several independently heatable platform segments (31, 32, 33, 34), - a print head (2) for depositing melted filament material (15), - a manipulation device (4), which is set up to move the print head (2) relative to the platform (3), and - A control device (5) which is set up to carry out a method according to one of the preceding claims. Device according to Claim 9 , wherein the manipulation device (4) comprises a robot arm which is set up to move the print head (2), in particular in multiple axes, relative to the platform (3).

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