3D PRINTING DEVICE HAVING A TEMPERATURE CONTROL DEVICE FOR APPLIED PRINT MATERIAL

Abstract

A 3D printing device includes at least one printing nozzle for a layer-by-layer application of a printing material provided for the production of a component to be printed along a direction of application (R). The 3D printing device has a temperature control device that is configured and provided both to cool and warm already applied printing material in the region of the printing nozzle.

Claims

1. A 3D printing device having at least one printing nozzle (10) for a layer-by-layer application of a printing material (50, 51) provided for the production of a component to be printed along a direction of application (R), characterized in that the 3D printing device (1) has a temperature control device (4) which is configured and provided both to cool and warm already applied printing material (50, 51) in the region of the printing nozzle (10).

2. The 3D printing device as claimed in claim 1, characterized in that the temperature control device (4) is configured and provided to apply new printing material by the printing nozzle (10) for warming already applied printing material (50) lying in the direction of application (R).

3. The 3D printing device as claimed in claim 1, characterized in that the temperature control device (4) is configured and provided for cooling printing material (51) applied by the printing nozzle after this printing material (51) has been applied by the printing nozzle (10).

4. The 3D printing device as claimed in claim 1, characterized in that at least one fluid flow with warmed or cooling fluid can be generated via the temperature control device (4) for the purpose of warming and/or cooling applied printing material (50, 51).

5. The 3D printing device as claimed in claim 4, characterized in that the temperature control device (4) comprises at least one support (41, 42, 43) with at least one outflow opening (41a-41e, 42a-42e, 43a-43e) for the fluid.

6. The 3D printing device as claimed in claim 5, characterized in that at least one first outflow opening (41a-41e) for generating a fluid flow provided to warm the printing material (50) and at least one second outflow opening (41a-41e) for generating a fluid flow provided to cool the printing material (50) are present on the at least one support (41, 42, 43).

7. The 3D printing device as claimed in claim 5, characterized in that the temperature control device (4) has at least two supports (41, 42, 43).

8. The 3D printing device as claimed in claim 7, characterized in that different supports (41, 42, 43) are provided on the 3D printing device for generating different fluid flows and/or for different fluids.

9. The 3D printing device as claimed in claim 4, characterized in that the temperature control device (4) has at least one valve (400) for controlling the inflow of different fluids and/or for controlling the inflow of a fluid via different fluid paths.

10. The 3D printing device as claimed in claim 9, characterized in that the temperature control device (4) is configured and provided with the at least one valve (400) to control an inflow of a warmed fluid via a different fluid path than the inflow of a cooling fluid.

11. The 3D printing device as claimed in claim 1, characterized in that the temperature control device (4) has at least one emitter (41a-41e, 42a-42e, 43a-43e) for warming already applied printing material (50).

12. The 3D printing device as claimed in claim 1, characterized in that the temperature control device (4) has an electronic control system (40) which is configured to control warming or cooling depending on the direction of application (R) in which the printing nozzle (10) is shifted.

13. A 3D printing device having at least one printing nozzle (10) for a layer-by-layer application of a printing material (50, 51) provided for the production of a component to be printed along a direction of application (R), characterized in that the 3D printing device has a temperature control device (4) which comprises a plurality of temperature control elements (41a-41e; 42a-42e; 43a-43e) provided for cooling already applied printing material (50, 51) and/or a plurality of temperature control elements (41a-41e; 42a-42e; 43a-43e) provided for warming already applied printing material (50, 51), wherein the temperature control elements (41a-41e; 42a-42e; 43a-43e) are provided on a section of a support (41, 42, 43) of the temperature control device (4) which extends at least partially around the printing nozzle (10).

14. The 3D printing device as claimed in claim 13, characterized in that the temperature control device (4) has an electronic control system (40) which is configured to employ different temperature control elements (41a-41e; 42a-42e; 43a-43e) depending on in which direction of application (R) the printing nozzle (10) is shifted.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The attached drawings illustrate by way of example possible embodiments of the proposed solution.

[0027] FIG. 1 shows a detail of a first embodiment of a proposed 3D printing device with a view of a printing nozzle on which an encircling support in the form of a ring with a plurality of temperature control elements for cooling or warming applied printing material, as required, is provided.

[0028] FIG. 2 shows a further embodiment of a proposed 3D printing device with two concentric ring-shaped supports with an optional valve control system for temperature control elements, formed as outflow openings, on the supports.

[0029] FIG. 3 shows, in a view that matches that in FIGS. 1 and 2, a further embodiment of a proposed 3D printing device with three in each case ring-shaped supports arranged concentrically relative to one another.

[0030] FIG. 4 shows schematic of a 3D printing device which may be equipped with a printing nozzle according to one of FIG. 1, 2, or 3, with a schematic illustration of a sensor system coupled to the corresponding temperature control device.

DETAILED DESCRIPTION

[0031] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0032] In some designs, e.g., WO 2018/039261 A1, prewarming an already applied printing material, lying in the direction of application, of a first layer before a further second layer of printing material is applied via the printing nozzle is performed. Corresponding prewarming of the already applied layer of printing material here serves to improve the adhesion of the newly applied printing material to the already present layer. WO 2018/039261 A1 describes, for example, the use of a laser or a flow of hot gas to warm the printing material which lies in the direction of application and has already been applied in advance.

[0033] FIG. 4 shows schematically a 3D printing device 1, with a printing nozzle 10, via which printing material for constructing a component or a workpiece respectively in layers may be applied to a printing platform 2. The printing nozzle 10 is hereby shifted, by way of example, in a direction of application R.

[0034] In the embodiment shown in FIG. 4, a layer of printing material 50 is already present on the printing platform, to which a second layer of printing material 51 is applied by the printing nozzle 10. The 3D printing device operates, for example, according to fused deposition modeling (FDM for short). The cooling of the applied printing material 50 begins at the same time as the first application of the printing material 50 to the printing platform 2. When the print head of the 3D printing device 1 with the printing nozzle 10 returns to the same point, the previously applied printing material 50 is significantly cooler than the new printing material 51 which is to be applied. This may have a negative effect on the connection of the two strands of material, and also on the strength of the component produced hereby.

[0035] Against this background, the embodiment in FIG. 4 provides to locally warm via a laser 4a printing material 50, lying in the direction of application R, of the previously applied layer 50. A region of the already applied printing material 50 to which the new printing material 50 is applied immediately afterward is warmed by virtue of this local warming by the laser 4a (or another emitter such as, for example, an infrared emitter or by a fluid flow with warmed fluid) and the associated input of energy into the printing material 50. As a result, the adhesion of the newly applied printing material 51 to the previously applied printing material 50 may be improved. Hybrid printing processes may also be implemented therewith in which plastic material with metallic powder is printed. As a result of the targeted input of heat, the printed metallic powder may here be subsequently fused in order, for example, to form metallic structures, for example in the form of at least one strip conductor, inside the printed plastic.

[0036] The input of energy into the already applied printing material 50 is controlled, depending on a determined temperature of the printing material 50, via a sensor system 3 which is coupled to a temperature control device 4 having the laser 4a and has one or more sensor devices. The sensor system 3 includes, for example, optical measuring devices and/or at least one temperature sensor. As an alternative or in addition to a temperature sensor, the sensor system 3 includes, for example, one or more thermal imaging cameras and is configured to calculate, in a computer-assisted fashion, a temperature of the printing material 50 in the region of the printing nozzle 10 and to actuate the laser 4a depending on this temperature determined in a computer-assisted fashion.

[0037] In an embodiment according to FIG. 1, an encircling ring-shaped support 41 is provided in the region of the printing nozzle 10. This ring-shaped support 41 is part of a temperature control device 4 via which printing material 50 of a first layer, applied in a preceding cycle, is warmed in a targeted fashion and/or via which the printing material 51 of a subsequent layer which has just been applied to the former layer may be cooled in a targeted fashion.

[0038] A plurality of temperature control elements 41a to 41e are spaced apart from one another on the support 41, e.g., spaced apart from one another equidistantly, and are provided so that they are distributed over the outer circumference of the ring-shaped support 41. Each temperature control element 41a to 41e may here be formed by an emitter for generating radiant heat or by an outflow opening for fluid such that the support 41 may be formed as an emitter ring or annular nozzle. Depending on whether printing material 50, 51 is intended to be cooled or warmed and in which direction of application R the printing nozzle 10 for applying new printing material 51 in layers is shifted, only one or only some of the temperature control elements 41a to 41e may be active.

[0039] If, for example, a plurality of outflow openings 41a to 41e are provided so that they are distributed on the circumference of the ring-shaped support, warmed fluid may, for example, flow out at outflow openings 41d and 41e lying in the direction of application R in order to locally warm, e.g., prewarm, printing material 50, of an already present layer, which lies in front of and underneath the printing nozzle 10, before printing material 51 applied at the printing nozzle 10 for a subsequent layer comes into contact with this printing material 50. Alternatively or additionally, cooling fluid may flow out at outflow openings 41a, 41b lying in the opposite direction to the direction of application R such that a cooling fluid flow may be generated in the direction of the printing material 51 which has just been applied in order to prevent deliquescence of this printing material 51. Applied printing material 50, 51 may accordingly be selectively warmed or respectively actively heated or cooled with the temperature control device 4 shown. Depending on the construction time of the current layer and/or depending on the section of the component to be produced, it may hereby be controlled in a targeted fashion whether warming or cooling is to take place and in which direction and at which point/points along the circumference of the printing nozzle 10 a fluid flow is to be generated.

[0040] The temperature control device 4 includes an electronic control system 40 for the purpose of automating the process. This electronic control system 40 may also be coupled, for example, to the sensor system 3 in order to control the degree of warming and/or cooling depending on what temperature the corresponding printing material 50 or 51 has.

[0041] In an alternative embodiment, the electronic control system 40 is configured to control warming or cooling depending on the direction of application by the support 41 being rotatably mounted around the printing nozzle 10d and being capable of being rotated by the electronic control system in a targeted fashion with the direction of application (and consequently a printing path). In this way, a cooling jet may be oriented backward at all times relative to the direction of application in order to cool printing material that has just been applied. At the same time, heat may be directed in the direction of application in order to warm a region on which printing material will be applied shortly. Alternatively or additionally, the outflow openings 41a to 41e may be closed and opened in a targeted fashion, individually or in groups, in an electronically controlled fashion via valves, e.g., piezoelectric valves, in order to be able to orient cooling and/or warming in a targeted fashion, e.g., depending on a current direction of application of the printing material and hence on a printing path.

[0042] Instead of a single support 41, the alternative embodiment in FIG. 2 provides two ring-shaped supports 41 and 42 of the temperature control device 4 that encircle the printing nozzle 10 concentrically to each other. Fluid flows provided only to warm the printing material 50 are hereby generated, for example, via a support 41 situated on the inside and its outflow openings 41a to 41e. In contrast, respective fluid flows with cooling fluid are generated via outflow openings 42a to 42e of the support 42 situated on the outside. The fluid is, for example, in both cases the same fluid, e.g., air. The air may either be warmed or be conveyed to a support 41 or the other support 42 in an unwarmed or cooled state, depending on whether the air is employed for warming or cooling purposes and via which of the supports 41, 42 it is intended for this air to be blown out. The air is, for example, supplied via a compressed air connection.

[0043] A valve control system with at least one (multiport) valve 400 may optionally be present to control the inflow to the supports 41, 42. This valve 400 is then also controlled via the electronic control system 40 of the temperature control device 4.

[0044] In the embodiment in FIG. 3, three ring-shaped supports 41, 42, and 43 concentrically encircling the printing nozzle 10 are provided. An alternative process gas in addition to warm and cold air may, for example, when required flow out via an additional outer ring-shaped support 43 with outflow openings 43a to 43e. Such a process gas used for cooling and/or warming purposes may, for example, be employed when a reactive printing material (for example, a carbon fiber reinforced plastic, a glass fiber reinforced plastic, or a specific metallic powder or binding agent) is to be printed which would oxidize undesirably during cooling or warming with air.

[0045] In each of the embodiments shown in FIGS. 1, 2, and 3, the temperature control device 4 may have suitable warming and/or cooling elements in order to warm or cool, as required, a respective fluid to be used. Moreover, the use of air as the fluid for generating a warming or cooling fluid flow is of course just an example. Thus, a process gas, e.g., an inert process gas, may also be used as an alternative embodiment in FIG. 1 or 2. A fused deposition modeling process using PA66 GF35 may, for example, be readily effectively performed with the alternative embodiments shown. Hereby, on the one hand, depending on the design-specific or material-specific requirements to be produced, active heating of previously applied printing material 50 may be implemented using warm air (at a temperature of approximately 150° C.) in order to obtain good adhesion and, on the other hand, cooling of the printing material 51 which has just been applied also needs to be provided, but for example in the case of sections of the component with a small cross-section and/or a small wall thickness, in order to prevent this printing material 51 from flowing away or deliquescing. A corresponding component heating and cooling is hereby integrated, via the temperature control device 4, in the region of the printing nozzle 10 and hence at the print head of the 3D printing device, for example, according to the alternative embodiment in FIG. 2 via a plurality of supports 41, 42, 43, with in each case a plurality of outflow openings 41a-41e, 42a-42e, in the shape of rings which encircle the printing nozzle 10.

[0046] The following is a list of reference numbers shown in the Figures. However, it should be understood that the use of these terms is for illustrative purposes only with respect to one embodiment. And, use of reference numbers correlating a certain term that is both illustrated in the Figures and present in the claims is not intended to limit the claims to only cover the illustrated embodiment.

LIST OF DESIGNATIONS

[0047] 1 3D printing device [0048] 10 printing nozzle [0049] 2 printing platform [0050] 3 sensor system [0051] 4 temperature control device [0052] 40 electronic control system [0053] 41, 42, 43 support [0054] 41a-41e outflow opening/emitter (temperature control element) [0055] 42a-42e outflow opening/emitter (temperature control element) [0056] 43a-43e outflow opening/emitter (temperature control element) [0057] 4a laser [0058] 400 multiport valve [0059] 50, 51 printing material [0060] R direction of application

[0061] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.