DEVICE FOR INFLUENCING THE VOLUMETRIC FLOW OF EXTRUDED PLASTICALLY DEFORMABLE MATERIAL

Abstract

A device for influencing the volume flow of extruded plastically deformable material conveyed to an outlet nozzle. A flange arranged between an extrusion unit and an outlet nozzle and is connected to the extrusion unit and the outlet nozzle. A duct from the extrusion unit and the outlet nozzle is incorporated in the flange. A piston is mounted in the flange to be rotatable perpendicular to the longitudinal axis of the duct and is located through the duct. In the piston there is a hole which opens into a bypass duct routed to a bypass nozzle. On the outer lateral surface of the piston there is at least one groove in the region of the duct so that, depending on the angular positions of the piston, material can be conveyed through the at least one groove to the outlet nozzle or through the hole to the bypass nozzle.

Claims

1. A device for influencing the volume flow of extruded plastically deformable material, which is fed to an outlet die during the additive manufacturing of components, comprising a flange, which is arranged between an extrusion unit and an outlet die and connected to the extrusion unit and the outlet die, wherein a channel that, proceeding from the extrusion unit, is formed up to the outlet die is introduced into the flange; and a piston is mounted in the flange so as to rotate perpendicularly to a longitudinal axis of the channel and is guided the channel; and a borehole is formed in the piston in the region of the channel, the borehole opening into a bypass channel that runs through the piston to a bypass die; and in addition to the borehole, at least one groove is formed in a region of the channel on an outer lateral face of the piston, which is arranged in a different angular range than the borehole or located around the borehole, so that extruded plastically deformable material can be fed, as a function of angular positions of the piston, through the at least one groove in the direction of the outlet die or through the borehole and the bypass channel out of the bypass die.

2. The device according to claim 1, wherein the at least one groove is formed in an outer lateral face of the piston across an angular range of at least 180° in the direction of rotation of the piston.

3. The device according to claim 1, wherein the at least one groove has a free cross-section that varies in a stepped or continuous manner across the length thereof, through which extruded plastically deformable material can be fed to the outlet die, when the piston has been rotated into an appropriate angular position.

4. The device according to claim 1, wherein multiple grooves are formed in angular ranges that are offset from one another, in and outer lateral face of the piston.

5. The device according to claim 1, wherein the piston is connected to a rotary drive controllable by open-loop or closed-loop control.

Description

DESCRIPTION OF THE DRAWINGS

[0029] The invention will be described by way of example hereafter.

[0030] In the drawings:

[0031] FIG. 1 shows a schematic sectional illustration of an example of a device according to the invention in a position in which the fed volume flow can be influenced; and

[0032] FIG. 2 shows the example shown in FIG. 1 in a position in which the feeding of extruded plastically deformable material to the outlet die is interrupted.

DETAILED DESCRIPTION OF THE INVENTION

[0033] FIG. 1 shows a flange 1, which at what here is the vertically upper side is connected to an extrusion unit, which is not shown. The extrusion unit feeds extruded plastically deformable material 6 in a channel 10, which runs through the flange 1, to the outlet die 3, which is clarified by the arrows.

[0034] A borehole is formed through the flange 1, perpendicularly to the longitudinal axis of the channel 10, or a hollow cylinder is inserted there. A piston 2 is rotatably mounted in the borehole or the hollow cylinder. In addition, seals are present, which are to prevent extrudate from leaking.

[0035] It is also apparent from FIG. 1 that a groove 2.1 is formed in the outer lateral face of the piston 2, through which the extruded plastically deformable material 6 can be fed to the outlet die 3 for additive manufacturing. A borehole 8 also is present on the outer lateral face of the piston 1 and runs into the interior of the piston 1 to a bypass channel 9, which, in turn, opens into a bypass die 5 (see FIG. 2).

[0036] The borehole 8 and the groove 2.1 are arranged in the example shown in FIG. 1 so that the groove 2.1 is guided in an arc around the borehole 8.

[0037] In the angular position of the piston 2 shown in FIG. 1, the borehole 8 does not communicate with the channel 10, so that extruded plastically deformable material 6 can be exclusively fed through the groove 2.1 to the outlet die 3.

[0038] When the piston 2 is rotated, in a manner not shown in FIG. 1, into an angular position in which plastically deformable material 6 can also find its way into the borehole 8, then through the bypass channel 9, and the bypass die 5, into a collection receptacle 4, only a portion of the entire volume flow of extruded plastically deformable material 6 which is fed from the extrusion unit is fed through the groove 2.1 to the outlet die 3. In this way, the volume flow of extruded plastically deformable material 6 which is provided for manufacturing in this angular position of the piston 2 can be influenced.

[0039] FIG. 2 shows a position of the piston 2 in which the pistons has been rotated into an angular position in which the groove 2.1 does not communicate with the channel 10. As a result, no connection exists between the extrusion unit and the outlet die 3.

[0040] Extruded plastically deformable material fed from the extrusion unit into the channel 10 is fed entirely into the borehole 8, from there through the bypass channel 9 to the bypass die 5, and from there, in this example, into the collection receptacle 4, where it can be temporarily stored as waste 7 or for reuse.