Nozzle device for a print head for a 3D printer and method for operating a print head having a nozzle device

Abstract

The invention relates to a nozzle device (80) for a print head (100) for a 3D-printer (150), wherein the nozzle device (80) is suitable for discharging a liquid phase (12) of at least one printable material, wherein the nozzle device (80) has an outlet opening (8), the cross-section of which is variably adjustable in order to change a volume flow of the liquid phase (12). The invention is characterised in that the nozzle device (80) has two nozzle bodies (61, 62) arranged concentrically one inside the other, wherein the inner nozzle body (61) is arranged within a threaded sleeve (26) in such a way that the inner nozzle body (61) is movable relative to the outer nozzle body (62) by rotating the threaded sleeve (26). The invention further relates to a method for operating a print head (100) having a nozzle device (80) according to the invention.

Description

[0001] Description

[0002] Title:

[0003] Nozzle device for a print head for a 3D printer and method for operating a print head with a nozzle device

[0004] The present invention relates to a nozzle device for a print head for a 3D printer and a method for operating a print head with a nozzle device according to the invention.

[0005] State of the art

[0006] A 3D printer for a material with variable viscosity receives a solid phase of this material as a starting material, creates a liquid phase from it, and selectively deposits this liquid phase at the locations corresponding to the object to be created. Such a 3D printer comprises a print head in which the starting material is prepared for printing. Furthermore, means are provided for generating relative movement between the print head and the work surface on which the object is to be created. This can involve moving either only the print head, only the work surface, or both the print head and the work surface.

[0007] The print head has a first operating state in which liquid material is discharged from it, and a second operating state in which no liquid material is discharged. The second operating state is entered, for example, when moving to a different position on the work surface and no material is to be dispensed along the way.

[0008] For example, the print head can be switched between the two operating states by switching the feed of the solid source material on or off.

[0009] The most common method is fused deposition modeling (FDM), in which a filament made from the starting material is melted in an electrically heated extruder nozzle and deposited layer by layer onto a platform. In this form, the starting material is very expensive.

[0010] DE 10 2021 202649 A1 discloses a print head for a 3D printer in which granules are plasticized via a piston and a heated section. When the piston presses on the granules, they are compressed, closing the nozzle of the print head.

[0011] From DE 10 2016 213439 A1 a screw extruder with an adjustable nozzle is known, whereby the nozzle can change a volume flow from the nozzle.

[0012] The invention is based on the object of providing a nozzle device for a print head for a 3D printer and a method for operating a print head with a nozzle device, which enable an optimized printing process, whereby high-quality melt is to be provided in reproducible quality.

[0013] Disclosure of the invention

[0014] Within the scope of the invention, a nozzle device for a print head for a 3D printer and a method for operating a print head with a nozzle device according to the invention were developed.

[0015] The invention relates to a nozzle device for a print head for a 3D printer, wherein the nozzle device is suitable for dispensing a liquid phase of at least one printable material, wherein the nozzle device has an outlet opening whose cross-section can be variably adjusted to change a volume flow of the liquid phase. According to the invention, the nozzle device has two nozzle bodies arranged concentrically one inside the other, wherein the inner nozzle body is arranged within a threaded sleeve in such a way that the inner nozzle body can be moved relative to the outer nozzle body by rotating the threaded sleeve. By the relative movement of the inner nozzle body to the outer nozzle body, the cross-section of the outlet opening of the nozzle device, or the nozzle cross-section, is changed in such a way that the volume flow of the liquid phase, or of a melt, changes.The two nozzle bodies arranged one inside the other thus ensure that the print head can print with different volume flow rates depending on the setting, which advantageously eliminates the need for an additional print head if multiple nozzle diameters would be required during a print job or printing process. When printing with a large opening cross-section of the outlet opening of the nozzle device, the printing process can be accelerated, particularly when areas of the component to be printed need to be filled. The nozzle device according to the invention makes it possible to avoid changing nozzles, which advantageously reduces downtime due to changeovers. This shortens the printing process. In addition, the adjustment effort required when changing the nozzle on the print head is reduced.

[0016] The component printed with the print head's nozzle assembly can also exhibit improved appearance, as, for example, the outer contour of the component is printed through a smaller cross-section of the exit opening. A smaller cross-section means a smaller nozzle diameter, or a smaller nozzle, which achieves high printing precision. The larger cross-section enables increased material throughput and thus faster filling of the component, which allows for faster filling of the component with the same print head path position.

[0017] Furthermore, the use of the nozzle device can improve component properties, such as strength, because a higher density can be achieved between the printed layers due to the improved fill density. Furthermore, a print head with the nozzle device has a compact design, which can reduce the weight of the print head. In a further development of the invention, the threaded sleeve can be controlled by an actuator of the nozzle device.

[0018] The threaded sleeve, controlled by the actuator, ensures the relative movement of the inner nozzle body to the outer nozzle body, which changes the nozzle cross-section and thus the volume flow of the liquid phase or melt. The threaded sleeve ensures the stroke and rotation of the inner nozzle body.

[0019] In a further development of the invention, the outer nozzle body has a recess on its inner wall and the inner nozzle body has a lateral opening at the level of the recess of the outer nozzle body.

[0020] In a further development, in a first operating state of the print head, the outlet opening of the nozzle device is formed by a nozzle opening of the inner nozzle body.

[0021] This results in a smaller nozzle diameter, which allows printing into fine outer contours, which advantageously have an improved appearance.

[0022] In a further development, in further operating states of the print head, the outlet opening of the nozzle device is formed by an opening cross-section, which results from the relative movement of the inner nozzle body to the outer nozzle body.

[0023] This allows for a variable nozzle diameter, allowing wider contours to be printed or areas of the component to be filled as needed. This can advantageously accelerate the printing process.

[0024] Furthermore, the invention relates to a method for operating a print head with a nozzle device according to the invention.

[0025] Further measures improving the invention are described in more detail below, together with the description of the preferred embodiments of the invention, with reference to the figures. Brief description of the drawing

[0026] They show:

[0027] Fig. 1 is a sectional view of a nozzle device according to the invention of a print head of a 3D printer;

[0028] Fig. 2 is a sectional side view of the nozzle device according to the invention in a first operating state;

[0029] Fig. 3 is a sectional drawing in a plan view of the nozzle device according to the invention in a first operating state;

[0030] Fig. 4 is a sectional drawing in a side view of the nozzle device according to the invention in a second operating state and

[0031] Fig. 5 is a sectional view of the nozzle device according to the invention in a second operating state.

[0032] Examples of implementation

[0033] Fig. 1 shows a sectional drawing of a nozzle device 80 according to the invention of a print head 10 of a 3D printer 150. The nozzle device 80 is suitable for dispensing a liquid phase 12 of at least one printable material, wherein the nozzle device 80 has an outlet opening 8 whose cross section is variably adjustable to change a volume flow of the liquid phase 12.

[0034] The nozzle device 80 has two nozzle bodies 61, 62 arranged concentrically one inside the other, wherein the inner nozzle body 61 is arranged within a threaded sleeve 26 such that the inner nozzle body 61 can be moved relative to the outer nozzle body 62 by rotating the threaded sleeve 26. The relative movement of the inner nozzle body 61 to the outer nozzle body 62 changes the cross-section of the outlet opening 8 of the nozzle device 80, or the nozzle cross-section, in such a way that the volume flow of the liquid phase 12, or of a melt, changes. The two nozzle bodies 61, 62 arranged one inside the other thus ensure that the print head 100 can print with different volume flows depending on the setting. The melt 12 is fed in via a channel 51. The fed melt 12 can be pressed into the nozzle device 80 via the channel 51 by an extruder (not shown).

[0035] The threaded sleeve 26 can be controlled by an actuator 6 of the nozzle device 80. A transmission device 85, driven by the actuator 6, between the actuator 6 and the threaded sleeve 26 ensures a lifting and rotating movement of the inner nozzle body 61 relative to the outer nozzle body 62.

[0036] The entry of liquid melt 12 upwards towards the actuator 6 is secured by an actuator cooling 7.

[0037] Fig. 2 shows a sectional drawing in a side view of the nozzle device 80 according to the invention in a first operating state and Fig. 3 shows a sectional drawing in a plan view.

[0038] The outer nozzle body 62 has a recess 65 on its inner wall 87, and the inner nozzle body 61 has a lateral opening 63 at the level of the recess 65 of the outer nozzle body 62. In the first operating state of the print head 100 shown here, the lateral opening 63 of the inner nozzle body 61 is closed by the inner wall 87 of the outer nozzle body 62, so that the outlet opening 8 of the nozzle device 80 is formed by a nozzle opening 81 of the inner nozzle body 61. This results in a small nozzle diameter of the nozzle device 80. The melt 12 is pressed through a channel 86 arranged in the inner nozzle body 61 to the nozzle opening 81 of the inner nozzle body 61.

[0039] The small cross-section means a small nozzle diameter 81 or a smaller nozzle, whereby a high level of printing precision is achieved. In this operating state, a seal is achieved between the two nozzle bodies 61, 62 by the outer surface or lateral surface 68 of the inner nozzle body 61 to the outer nozzle body 62 in the region of the outlet opening 8. Fig. 4 shows a sectional drawing in a side view of the nozzle device 80 according to the invention in a second operating state and Fig. 5 shows a plan view. The outlet opening 8 of the nozzle device 80 is formed in the operating state shown here by an opening cross-section 82 which results from the relative movement of the inner nozzle body 61 to the outer nozzle body 62.In this operating state, the transmission device 85 between the actuator 6 and the threaded sleeve 26, driven by the actuator 6, ensures a lifting and rotating movement of the inner nozzle body 61 relative to the outer nozzle body 62. The inner nozzle body 61 was rotated by 180° and the simultaneous upward lifting movement ensures a gap 66 between the inner nozzle body 61 and the outer nozzle body 62. In the second operating state of the print head 100 shown here, the lateral opening 63 of the inner nozzle body 61 is aligned with the recess 65 of the outer nozzle body 62, whereby a connection is established between the opening 63 and the recess 65.

[0040] The outlet opening 8 of the nozzle device 80 is thus formed by a nozzle opening 82, which is formed by the resulting gap 66 between the inner nozzle body 61 and the outer nozzle body 62.

[0041] Depending on the rotation and stroke of the inner nozzle body 61 through the threaded sleeve 26, a variable nozzle diameter 8 can be achieved, whereby the lateral opening 63 of the inner nozzle body 61 is either closed and sealed by the inner wall 87 of the outer nozzle body 62 or kept open, depending on the position. This is regulated by the stroke and the additional rotation of the inner nozzle body 61 via the threaded sleeve 26.

[0042] When the inner nozzle body 61 is lifted, the melt 12 exits through the nozzle opening 82 formed by the gap 66 due to the lower resistance, instead of continuing to exit through the narrower nozzle opening 81 of the inner nozzle body 61. Before this, the melt 12 fills the recess 65 and flows around the tip of the inner nozzle body 61, completely filling the gap 66, so that the melt 12 can subsequently be discharged through the nozzle opening 82.

[0043] In addition, the volume flow or mass flow of the melt 12 can be controlled depending on the position of the opening 63 of the inner nozzle body 61 in relation to the recess 65 of the outer nozzle body 62.

Claims

Claims 1. Nozzle device (80) for a print head (100) for a 3D printer (150), wherein the nozzle device (80) is suitable for dispensing a liquid phase (12) of at least one printable material, wherein the nozzle device (80) has an outlet opening (8) whose cross-section is variably adjustable to change a volume flow of the liquid phase (12), characterized in that the nozzle device (80) has two nozzle bodies (61, 62) arranged concentrically one inside the other, wherein the inner nozzle body (61) is arranged within a threaded sleeve (26) such that the inner nozzle body (61) is movable relative to the outer nozzle body (62) by rotating the threaded sleeve (26).

2. Nozzle device (80) according to claim 1, characterized in that the threaded sleeve (26) can be controlled by an actuator (6) of the nozzle device (80).

3. Nozzle device (80) according to one of the preceding claims, characterized in that the outer nozzle body (62) has a recess (65) on its inner wall and the inner nozzle body (61) has a lateral opening (63) at the level of the recess (65) of the outer nozzle body (62).

4. Nozzle device (80) according to one of the preceding claims, characterized in that in a first operating state of the print head (100) the outlet opening (8) of the nozzle device (80) is formed by a nozzle opening (81) of the inner nozzle body (61).

5. Nozzle device (80) according to one of the preceding claims, characterized in that in further operating states of the print head (100), the outlet opening (8) of the nozzle device (80) is formed by an opening cross-section (82) which results from the relative movement of the inner nozzle body (61) to the outer nozzle body (62).

6. Method for operating a print head (100) having a nozzle device (80) according to one of the preceding claims.

Images