Method and Apparatus for Treating Parts

Abstract

To treat parts printed by means of 3D printing from the powder bed, they are inserted into a trough belt conveyor which transports and circulates the parts and in which the parts are acted on by a fluid jet during the transport.

Claims

1.-15. (canceled)

16. A method for treating parts printed by means of 3D printing from a powder bed, said method comprising the following steps: inserting the parts into a trough belt of a trough belt conveyor that is provided with entrainers and that extends in its longitudinal direction between an inlet and an outlet; transporting the parts in the longitudinal direction through the trough belt from the inlet to the outlet by moving the trough belt in a direction of revolution; and circulating the parts within the trough belt during the transport, wherein the parts are acted on by at least one fluid jet during the transport.

17. The method in accordance with claim 16, wherein the trough belt conveyor extends horizontally between the inlet and the outlet.

18. The method in accordance with claim 16, wherein the fluid jet is introduced into the interior of the trough belt conveyor through at least one nozzle that is moved to and fro in at least one of the longitudinal direction and transversely thereto during the action.

19. The method in accordance with claim 16, wherein the fluid jet is introduced into the interior of the trough belt conveyor through at least one nozzle whose spacing from the base of the trough belt is varied during the action.

20. The method in accordance with claim 16, wherein, during the action, an air curtain is produced transversely to the longitudinal direction in the region of at least one of the outlet and the inlet.

21. The method in accordance with claim 20, wherein the air flow used for the air curtain is ionized.

22. The method in accordance with claim 16, wherein the revolving trough belt is held in a stationary manner in a horizontal position during the insertion of the parts and during the action.

23. The method in accordance with claim 16, wherein the fluid jet includes a blasting medium that is separated from powder after the action and that is used again for the action.

24. The method in accordance with claim 16, wherein the trough belt conveyor is used in a closed transport circuit for the transport and the treatment of parts.

25. An apparatus comprising a trough belt conveyor having a revolving trough belt that extends in a longitudinal direction, which extends between an inlet and an outlet, wherein the trough belt has a transport device to transport parts in the longitudinal direction from the inlet to the outlet through the trough belt conveyor and to circulate them in so doing, and a blasting device for applying at least one fluid jet to the parts during the transport.

26. The apparatus in accordance with claim 25, wherein the apparatus is configured to carry out a method of treating parts printed by means of 3D printing from a powder bed, said method comprising the following steps: inserting the parts into the trough belt of the trough belt conveyor that is provided with entrainers; transporting the parts in the longitudinal direction through the trough belt from the inlet to the outlet by moving the trough belt in a direction of revolution; and circulating the parts within the trough belt during the transport; wherein the parts are acted on by at least one fluid jet during the transport.

27. The apparatus in accordance with claim 25, wherein the revolving trough belt extends horizontally between the inlet and the outlet.

28. The apparatus in accordance with claim 25, wherein an input chute, which is inclined downwardly with respect to the horizontal in the direction of the inlet, is provided at the inlet of the trough belt.

29. The apparatus in accordance with claim 25, wherein a discharge chute, which is provided with guide vanes, is provided at the outlet of the trough belt.

30. The apparatus in accordance with claim 29, wherein the peripheral contour of the discharge chute is adapted to the contour of the outlet of the trough belt.

31. The apparatus in accordance with claim 25, wherein the blasting device has at least one nozzle that is movable to and fro in the longitudinal direction and/or transversely thereto and/or whose spacing from the base of the trough belt is variable during the action.

32. The apparatus in accordance with claim 31, wherein an image capture apparatus is provided that controls a movement of the nozzle.

33. The apparatus in accordance with claim 25, wherein the revolving trough belt, viewed in cross-section, is formed symmetrically with respect to a vertical extending through a central axis of the belt trough and is held in a stationary manner in the horizontal.

34. The apparatus in accordance with claim 25, wherein it is assembled on a transportable base frame and has a maximum height of 2095 mm and a maximum depth of 1555 mm.

Description

[0023] The present invention will be described in the following purely by way of example with reference to an advantageous embodiment and to the enclosed drawings.

[0024] There are shown:

[0025] FIG. 1 a sectioned side view of an apparatus for treating parts;

[0026] FIG. 2 a cross-sectional view through the apparatus of FIG. 1;

[0027] FIG. 3 a sectioned perspective view of the apparatus of FIG. 1 and

[0028] FIG. 2; and

[0029] FIG. 4 a further sectioned perspective view of the apparatus of FIG. 1 to FIG. 3.

[0030] FIG. 1 shows an apparatus for treating parts that are printed by means of 3D printing, for example, for unpacking parts from a powder bed. The apparatus is assembled on a transportable base frame 10 and has a trough belt conveyor 12 having a trough belt 14 that is guided in a manner known per se via a plurality of deflection rollers 16 (FIG. 2) and guides 18 such that a belt trough 20 (FIG. 2) is formed by the trough belt 14. For this purpose, the trough belt comprises a plurality of bars which are connected in parallel with one another and at which entrainers (not shown) are located that are fastened to the outer sides of the bars so that they project into the interior of the belt trough 20 on the revolution of the trough belt. The trough belt 14 is driven in a revolving manner via a drive not shown in more detail.

[0031] As in particular FIG. 1 and FIG. 2 illustrate, the trough belt 14 extends in a horizontal and stationary manner in the longitudinal direction between an inlet 22 and an outlet 24. In the case of a revolving trough belt, parts which have been conveyed through the inlet 22 into the interior of the belt trough 20 are conveyed through the trough belt conveyor 12 in the longitudinal direction L so that the longitudinal direction L simultaneously also represents the transport direction of the parts in which said parts are conveyed from the inlet 22 to the outlet 24 through the trough belt conveyor and are circulated in so doing.

[0032] A tubular input chute 26 is provided at the inlet 22 of the trough belt 14, the peripheral contour of said tubular input chute 26 being adapted to the circular contour of the trough belt 14 in the region of the belt trough, wherein the input chute 26 is inclined downwardly with respect to the horizontal in the direction of the inlet 22. Thus, the input chute 26 extends upwardly from the inlet of the trough belt 14 against the transport direction L.

[0033] A discharge chute 28, whose peripheral contour is likewise adapted to the contour of the outlet 24 of the trough belt 14, is furthermore provided at the outlet 24 of the trough belt 14. Accordingly, the discharge chute 28 has the shape of a tubular socket whose diameter corresponds to the diameter of the belt trough 20 formed by the trough belt 14. At its inner wall, the discharge chute 28 is provided with a plurality of guide vanes 30 that are inclined downwardly in an approximately helical manner starting from the outlet 28 and that ensure that parts which have been lifted slightly by the trough belt conveyor 12 do not fall directly downwardly after leaving the trough belt conveyor 14, but are conveyed in a guided manner in the direction of a collection space 32.

[0034] As FIG. 2 illustrates, the contour of the peripheral trough belt 14, viewed in cross-section, is formed symmetrically, and indeed with respect to a vertical plane extending through a central axis M of the belt trough 20. Furthermore, the trough belt 14 can indeed revolve, but it is overall held in a stationary manner and fixed in the horizontal within the base frame 10.

[0035] In the region of the upper opening of the belt trough formed by the trough belt 14, a blasting device 34 is provided that comprises a plurality of nozzles 36 that are fastened to a longitudinal support 38. The longitudinal support 38 is again suspended in an oscillating manner and can be moved to and fro in and against the transport direction L (to the right and left in FIG. 1) by means of a drive, not shown. At the same time, the longitudinal support 38 with the nozzles 36 fastened thereto can also be lifted in the direction of the base of the trough belt 14 and against this direction by means of a lifting device 40.

[0036] Finally, the nozzles 36 at the support 38 can also have a separate drive to move said nozzles 36 to and fro, in particular transversely to the transport direction L, and/or to rotate them along a path.

[0037] In accordance with an embodiment, to control the movement of the individual nozzles or also of the support 38 in the longitudinal direction L and/or transversely thereto, a control device can be provided in the vertical that is coupled to an image capture apparatus that captures the interior of the belt trough 20. A targeted movement of the nozzles 36 can then be achieved with the aid of image recognition software to treat the individual parts with a fluid jet.

[0038] A respective air curtain 42 is provided both in the region of the inlet 22 and in the region of the outlet 24 and extends substantially over the total cross-sectional surface of the inlet or the outlet, wherein the air curtain emits ionized air that serves as a barrier to prevent an exit of powder and/or blasting medium from the region of the trough belt conveyor.

[0039] The fluid jet which is applied to the parts within the trough belt conveyor can comprise pure compressed air. However, other known blasting media such as glass beads, plastic balls, corn meal or the like can also be used. Such a blasting medium can be stored in a blasting medium storage container 44 (FIG. 4) and can be supplied to the nozzles 36 from there. To reuse the blasting medium for an application, it is collected in a collection hopper 46 (FIGS. 2 and 3) at whose base a screw conveyor 48 is provided that conveys the blasting medium into a return channel 50 that is in turn connected to a cyclone (not shown) to clean the blasting medium of powder residues. After exiting from the cyclone, the blasting medium is once again guided through a vibrating screen, wherein a subsequent blasting medium dosing with blasting medium from the blasting medium container 44 can also take place in this region. The reference numeral 52 in FIG. 1 designates a container for separated powder residues.

[0040] In the interior of the blasting chamber 54, in which the trough belt conveyor 12 is located, an air suction 56 is provided by which powder dust is sucked from the blasting chamber 54 and is fed to a filter 60 by means of a fan 58. The filter contents can be fed to a residual powder container 62 at regular intervals. The air suction can also be designed such that a suction of dust and excess blasting medium takes place from the region of the inlet and/or outlet.

[0041] As in particular FIG. 3 and FIG. 4 illustrate, the apparatus described above is extremely compact in design and has a maximum height H of 2095 mm and a maximum depth T of 1555 mm. The apparatus assembled on the base frame 10 can be transported in a simple manner by means of a forklift truck or a lift truck whose forks can be inserted into two reception openings 64 and 66 provided at the lower side. The apparatus is provided with a housing that is closed at all sides and that is provided with an access flap 68 at the front side to reach the nozzles 36 from outside. A further flap 70 is provided beneath the access flap 68 to grant access to the blasting medium recirculation and to a screen drawer. The doors 72 enable access to the residual powder container 52 and to the blasting medium storage container 44.

[0042] A further access flap 74 (FIG. 3) is provided at the rear side of the apparatus and provides access to the filter 60. An access door is also provided at the rear side, enables access to the present pneumatics and the blast hoses, and enables a screen change.

[0043] A cover 76 at the upper side of the housing enables access to the fan 58. A further cover 78 at the upper side of the housing enables a repair and maintenance of the nozzle lifting unit.

[0044] Finally, two further openings for a workpiece removal are provided in the region of the discharge hopper 28. A pivot flap 80, through which the unpacked parts can be manually removed from the front, is provided at the front side of the housing. An outlet opening 82, through which the workpieces can automatically be laterally discharged, is likewise provided at the adjacent side wall of the housing. In this way, the apparatus can be used in a closed transport circuit for a transport and the treatment of parts.

[0045] In the operation of the apparatus described above, the parts to be treated are first transported manually or automatically via the input chute 26 to the inlet 22 of the trough belt conveyor 12 whose trough belt 14 is driven in a revolving manner. The parts conveyed into the interior of the belt trough are hereby transported in the longitudinal direction L through the trough belt, and indeed from the inlet 22 to the outlet 24, wherein the parts are indeed circulated during the transport, but do not accumulate. At the same time, the parts are subjected to blasting media, which exit from the nozzles 36, by fluid jets during the transport. In this respect, the parts are treated, for example unpacked or deburred or roughened, and are removed from the region of the belt conveyor 12 via the discharge chute 28 after the passing through of the belt trough 20 through the outlet 24. The air curtains in the region of the inlet and the outlet prevent an exiting of powder dust in this respect. The nozzles 36 can be moved both in and against the transport direction L and also transversely thereto or can also be rotated. A movement of the nozzles 36 in a vertical direction is also possible. An optimized application of blasting medium to the parts can thus take place.

[0046] In the circuit, the blasting medium itself is returned and cleaned via the screw conveyor 48 and is then returned to the circuit again.