MACHINE FOR ADDITIVE MANUFACTURING AND RELATED METHOD OF ADDITIVE MANUFACTURING

Abstract

The present invention relates to a machine that enables the additive manufacturing of parts making use of high viscosity resins and which comprises a structure (1); a conveying module (2), with a movable support (3) and a displacement mechanism (5), to house and move the printing surface in a vertical direction; a light source (6), at least one reservoir (11) of material; a material supply module (8), connected to the reservoir (11) of material and intended for applying a layer of printing material on a conveyor substrate (9), which conveys the layer of printing material from the material supply module (8) to the printing surface (4), wherein it is cured; and a fastening system (10), to fasten and move the conveyor substrate.

Claims

1. A machine for additive manufacturing comprising: a structure (1); a conveying module (4), comprising a movable support (5), intended to house a printing surface (3), on which a part is printed, to move said part in a vertical direction, and a displacement mechanism (6) connected to the structure (1); at least one light source (10), fixed to the structure (1); at least one reservoir (11) of material, located in the structure (1) and intended to contain a printing material; a material supply module (12), connected to the reservoir (11) of material and intended to apply a layer of printing material on a conveyor substrate (2), which is intended for transporting the printing material from the material supply module (12) to the printing surface (3); and a fastening system (18), comprising: one or more fixing elements (19, 20), located on linear guides (26) and intended to hold the transparent conveyor substrate (2) to the structure (1), two or more rotating elements (27, 28) with respect to the structure (1) intended to serve as support points for the conveyor substrate (2), and which rotate on themselves to enable the movement of the conveyor substrate (2); one or more displacement motors (25) which move the fixing elements (19, 20) to move the conveyor substrate (2).

2. The machine for additive manufacturing according to claim 1, wherein the light source (10) is a projector, a screen or a laser.

3. The machine for additive manufacturing according to claim 1, wherein the light source (10) is of the ultraviolet or visible light type.

4. The machine for additive manufacturing according to any of the preceding claims, wherein the conveying module (4) comprises an automatic levelling mechanism, system or routine (9) with a positioning frame, which enables the positioning of the printing surface (3) to be adjusted.

5. The machine for additive manufacturing according to any one of the preceding claims, wherein the displacement mechanism (6) of the conveying module (4) comprises one or more spindles (7) that transmit a movement guided by linear guide elements (8) connected to the movable support (5).

6. The machine for additive manufacturing according to any of the preceding claims, wherein the printing surface (3) and the movable support (5) form a single element.

7. The machine for additive manufacturing according to any of the preceding claims, comprising a fixing element (34) in the fastening system (18) and four rotating elements (27, 28, 35, 36), and the substrate (2) is intended to be arranged in an O-shape, wherein the fixing element (34) is located on linear guides (37) and is intended to hold the conveyor substrate (2) at two ends to the structure (1), at an upper level and parallel to the printing surface (3), and to move on the linear guides (37) alternately, in two directions, to produce a movement in the conveyor substrate (2).

8. The machine for additive manufacturing according to claim 7, wherein the substrate (2) is connected to the central and movable fixing element (2) by means of two connecting bars (38, 39) that are fixed to the two ends of the substrate (2) and are connected to the fixing element (34) by means of two C-shaped fixing elements (40, 41).

9. The machine for additive manufacturing according to any of claims 7 and 8, further comprising a tensioning system (42) connected to the two upper rotating elements (35, 36) and intended to move the upper rotating elements (35, 36) closer to or away from each other through the movement of a central transverse spindle (43).

10. The machine for additive manufacturing according to any of claims 1 to 6, comprising two fixing elements (19, 20) in the fastening system (18) and two rotating elements (27, 28), and the substrate (2) is intended to be arranged in a U-shape, wherein the fixing elements (19, 20) comprise: a lower block (23), to engage the conveyor substrate (2) that houses a self-tensioning motor (29, 30) of the conveyor substrate (2), and an upper block (21), comprising a tilting element (22), to align the conveyor substrate (2).

11. The machine for additive manufacturing according to any of the preceding claims, wherein the at least one material supply module (12) comprises a cartridge (13) and a material supply roller (14), located tangentially to at least one of the rotating elements (27, 28) of the fastening system (18).

12. The machine for additive manufacturing according to claim 11, wherein the material supply module (12) further comprises a thickness control module (15), which comprises a runner (16), connected to the cartridge (13) and to the supply roller (14) and which moves linearly, and a supply motor (17), that drives the movement of the runner.

13. The machine for additive manufacturing according to any of the preceding claims, further comprising a material collection module (31) in addition to an excess material collection tray (32), a material filter and a recirculation conduit, which directs the collected material towards the cartridge (13) or towards the reservoir (11).

14. The machine for additive manufacturing according to claim 13, wherein the material collection module (31) comprises a spatula (33), placed near the conveyor substrate (2) so that it presses the same to recover the excess material.

15. The machine for additive manufacturing according to claim 14, wherein the material collection module (31) further comprises an activation mechanism connected to the spatula (33), which enables it to move closer to or be removed from the conveyor substrate (2).

16. The machine for additive manufacturing according to any of the preceding claims, wherein the material used is photosensitive resin with a viscosity greater than or equal to 2000 cps (mPa*s) at 25° C.

17. The machine for additive manufacturing according to any of the preceding claims, wherein the material used is photosensitive resin filled with reinforcement material.

18. The machine for additive manufacturing according to any of the preceding claims, wherein the light source (10) is located above the working surface.

19. The machine for additive manufacturing according to any of the preceding claims, further comprising a cleaning module, comprising two rollers having a soft material arranged thereon, a cleaning motor for moving the rollers and a cleaning substrate that extends over the two rollers in a circular shape, such that it can rotate continuously.

20. The machine for additive manufacturing according to claim 19, wherein the cleaning module further comprises a runner, connected to the rollers, and a linear guide, to move the rollers, the cleaning motor and the cleaning substrate, in a vertical direction.

21. The machine for additive manufacturing according to any of claim 19 or 20, wherein the cleaning module further comprises a waste collection element and a solvent material application element, to clean the printing surface (3).

22. The machine for additive manufacturing according to any of claims 19 to 21, wherein the cleaning module further comprises one or more radiation sources installed in the structure (1), to dry the printing surface (3).

23. A method of additive manufacturing that uses of the machine for additive manufacturing according to any of claims 1 to 22, comprising the steps of: a) providing a conveyor substrate placed in the fastening system (18); b) tensioning the conveyor substrate (2) by means of the fastening system (18); c) activating the light source (10); d) placing the feeding system at a distance equal to the desired layer thickness of the conveyor substrate (2); e) moving the fastening system (18), lowering a first fixing element (19) and lifting a second fixing element (20); f) supplying printing material on the conveyor substrate (2) along a working length, from a material supply module (12) located under the first fixing element (19); g) lifting the working surface to a distance from the conveyor substrate (2) equal to the thickness of produced layers plus the thickness of a new layer; h) irradiating the uncured printing material by means of the light source (10) producing a predetermined shape, curing a layer; i) lowering the conveying module (4), peeling the cured layer off the conveyor substrate (2); and j) repeating steps e) to i).

24. The method according to claim 23, wherein the printing direction is of the top-down type, and the part is printed from the lower area thereof towards the upper area.

25. The method according to any of claim 23 or 24, further comprising a step prior to activating the light source (10), of ensuring the coplanarity of the conveying module (4) with the conveyor substrate (2) by means of the automatic levelling mechanism, system or routine (9).

26. The method according to any of claims 24 to 25, wherein in the step of supplying material on the conveyor substrate (2), once the printing material has been supplied in the working area of the conveyor substrate (2), the movement of the fastening system (18) is continued without supplying more printing material.

27. The method according to any of claims 23 to 26, further comprising the step of activating the material collection module (31), removing the uncured material to reintroduce it into the material supply module (12).

28. The method according to any of claims 23 to 27, wherein a first cartridge (13) contains a first printing material and at least one second cartridge (13) comprises a second printing material, so that a printing material is alternately supplied in each movement of the conveyor substrate (2).

29. The method according to claim 28, wherein the step of moving the conveying module (4) towards the conveyor substrate (2) in the supply of the second printing material is carried out up to a distance equal to the set of thicknesses already printed, so that the second printing material is added to the same layer as the first printing material.

30. The method according to any of claim 28 or 29, further comprising the step of activating the cleaning module, to avoid contamination of the materials.

Description

DESCRIPTION OF THE DRAWINGS

[0063] As a complement to the description provided herein, and for the purpose of helping to make the features of the invention more readily understandable, in accordance with a preferred practical exemplary embodiment thereof, said description is accompanied by a set of drawings constituting an integral part of the same, which by way of illustration and not limitation, represent the following:

[0064] FIG. 1 shows a schematic view of a preferred embodiment of the machine of the invention.

[0065] FIG. 2 shows a schematic view of a preferred embodiment of the conveying module.

[0066] FIG. 3 shows a front view of a preferred embodiment of the conveying module.

[0067] FIG. 4 shows a schematic view of a preferred embodiment of the material supply module.

[0068] FIG. 5 shows a schematic view of a preferred embodiment of the fastening system.

[0069] FIG. 6 shows a front view of a preferred embodiment of the fastening system.

[0070] FIG. 7 shows a schematic view of a preferred embodiment of the material collection module.

[0071] FIG. 8 shows a schematic view of a preferred embodiment of the method of additive manufacturing of the invention.

[0072] FIG. 9 shows a schematic view of a second preferred embodiment of the machine of the invention.

[0073] FIG. 10 shows a schematic view of a second preferred embodiment of the fastening system of the invention.

PREFERRED EMBODIMENT OF THE INVENTION

[0074] The invention relates to a machine that enables the additive manufacturing of parts layer by layer. The printer of the invention enables the consumption of conveyor substrate (2) and printing material to be reduced due to the configuration thereof, which will be explained below by means of preferred exemplary embodiments shown in FIGS. 1 to 10.

[0075] FIG. 1 shows a schematic view of the machine as a whole. The printer has a structure (1), on which different modules are mounted that enable parts to be produced by means of additive manufacturing.

[0076] In particular, the machine comprises a conveying module (4), an ultraviolet light source (10), two reservoirs (11) of material, two material supply modules (12), a fastening system (18) and a material collection module (31).

[0077] The operation thereof is based on the use of a conveyor substrate (2) that is responsible for transferring a printing material to the part, layer by layer.

[0078] FIG. 2 shows a schematic view of the conveying module (4) of the machine of the invention.

[0079] The conveying module (4) in turn comprises a movable support (5), a printing surface (3) and a displacement mechanism (6). Thus, the part to be built will be produced layer by layer on the printing surface (3), which is moved by means of the displacement mechanism (6).

[0080] The displacement mechanism (6) is connected to the movable support (5), and produces an upward and downward movement in the same. Moreover, the movable support (5) is intended to house the printing surface (3). Thus, when the movable support (5) moves by means of the displacement mechanism (6), the printing surface (3) also moves, in order to place it in position to receive a new layer of printing material on the part that is being produced on said printing surface (3).

[0081] The conveying module (4), therefore, produces a vertical movement on the printing surface (3) in order to enable the part to be produced layer by layer and said printing surface (3) to be removed during a material supply process, in order to do it safely.

[0082] The displacement mechanism (6) has four spindles (7) through which four guide elements (8) which hold the movable support (5) of the conveying module (4) move. The guide elements (8) of the displacement mechanism (6) enable the movement of the movable support (5) and the printing surface (3).

[0083] FIG. 3 shows a front view of the conveying module (4), which further comprises an automatic levelling mechanism (9). The automatic levelling mechanism (9) is intended to enable the fine adjustment in the positioning of the printing surface (3) with respect to the conveyor substrate (2).

[0084] The ultraviolet light source (10) is, in this case, a DLP projector and is intended to produce a light beam with a predetermined shape in order to cure the printing material on the part to be built. In this case, the printing material is high viscosity photosensitive resin, with a viscosity greater than 2000 cps (mPa*s) at 25° C., curable by means of ultraviolet light.

[0085] The projector is attached to the structure (1) by means of a support that enables the movement thereof in the three directions of space, in order to correctly calibrate the focus of the light beam produced. In this way, high precision is achieved in the production of each layer of the part to be built.

[0086] The machine shown in FIG. 1 further comprises two reservoirs (11) of material that are each intended to contain a printing material, which can be the same, or, preferably, different. The reservoirs (11) of material are fixed to the structure (1) and are refillable.

[0087] FIG. 4 shows a front view of the material supply modules (12). Each material supply module (12) of the machine is responsible for supplying the printing material, the photosensitive resin, towards the conveyor substrate (2). The material supply module (12) comprises in this case a cartridge (13) and a supply roller (14).

[0088] Each material supply module (12) is connected to one of the two reservoirs (11), so that the printing material contained in the reservoir (11) is supplied to the cartridge (13) of the material supply module (12).

[0089] Once in the cartridge, the printing material is dosed on the conveyor substrate (2) by using the supply roller (14) of the material supply module (12). As it rotates, the supply roller (14) supplies a layer of printing material in a continuous and controlled manner to the conveyor substrate (2).

[0090] FIG. 5 shows the fastening system (18) of the machine of the invention in a preferred embodiment. The fastening system (18) is intended to hold the conveyor substrate (2) in position.

[0091] For this, it comprises two fixing elements (19, 20), two rotating elements, in this case, fixed rollers (27, 28) and two displacement motors (25). In this case, the fixing elements (19, 20) comprise an upper block (21) and a lower block (23).

[0092] FIG. 6 shows a front view of the fastening system (18) and, in particular, of the upper block (21) and lower block (23) of the fixing elements (19, 20). The upper block (21) of each fixing element (19, 20) is of the clamp type and enables the conveyor substrate (2) to be held by means of an adjustable screw (24).

[0093] In the lower block (23), each fixing element (19, 20) houses one of the self-tensioning motors (29, 30) of the fastening system (18) that enables the movement of the fixing elements (19, 20) and, therefore, of the conveyor substrate (2). Additionally, the lower block (23) also houses a self-tensioning motor (29, 30) that enables the necessary tension to be automatically provided on the conveyor substrate (2). Furthermore, in the lower block (23) a tilting element (22) is further arranged in order to align the conveyor substrate (2).

[0094] The fixing elements (19, 20) are intended to move each of the two ends of the conveyor substrate (2), in order to produce movement in the same. Thus, in the movement of said fixing elements (19, 20), if one of the two is lifted, the other is lowered the same distance and vice versa. The movement of the fixing elements (19, 20) is carried out along two linear guides (26).

[0095] Moreover, the fixed rollers (27, 28) of the fastening system (18) serve as support points in the path of the conveyor substrate (2). To do this, they are fixed to the structure (1), so that the only degree of freedom of movement thereof is the rotation on themselves. Then, the conveyor substrate (2) rests on both fixed rollers (27, 28) and when the fixing element (19) located on the left side is lowered, and therefore the fixing element (20) located on the right side is lifted, the fixed rollers (27, 28) rotate on themselves anticlockwise in order to enable the smooth movement of the conveyor substrate (2), maintaining a U-shape in the placement thereof with respect to the structure (1).

[0096] FIG. 1 also shows the relative position of the material supply module (12) with respect to the fixed roller (27, 28) of the fastening system (18). Thus, the supply roller (14) of the material supply module (12) is located tangentially to the fixed roller (27, 28) of the fastening system (18) and moved with respect to it a distance equal to the desired layer thickness to be placed on the conveyor substrate (2) by means of the material supply module (12). Thus, as the supply roller (14) rotates, it supplies a layer of material with a controlled thickness on the conveyor substrate (2).

[0097] In order to vary the thickness of the layer of material supplied to the conveyor substrate (2), the material supply module (12) further comprises a thickness control module (15) which in turn comprises a runner (16) and a supply motor (17). The runner (16) is connected to the supply roller (14) and moves linearly by means of the supply motor (17), in a horizontal direction, thus modifying the thickness of the layer of material supplied.

[0098] FIG. 7 shows a front view of the material collection module (31), which is coupled with the material supply module (12). The material collection module (31) comprises a material collection tray (32), a spatula (33), a recirculation conduit and a filter. The spatula (33) of the material collection module (31) moves closer to the surface of the conveyor substrate (2) once the curing of one layer of the part to be built has been completed. Thus, the movement of the conveyor substrate (2) forces the uncured printing material to come into contact with the spatula (33) which removes it from the conveyor substrate (2) and enables it to fall onto the material collection tray (32). Once in the material collection tray (32), the excess material is directed towards the recirculation conduit and is filtered, by means of the filter. The recirculation conduit conveys the excess material to the cartridge (13) or the reservoir (11) in order to reuse it later.

[0099] FIG. 8 shows a diagram of a preferred embodiment of the method of additive manufacturing of the invention.

[0100] FIG. 8 shows the conveyor substrate (2) placed on the fixed rollers (27, 28) of the fastening system (18) and tensioned in order to move with the movement of the fixing elements (19, 20).

[0101] The ultraviolet light source (10) is activated in order to enable the printing material to cure.

[0102] Then the position of the material supply module (12) is calibrated in order to set the layer thickness to be supplied, moving the outer surface of the supply roller (14) of the material supply module (12) closer to or away from the fixed roller (27, 28) of the corresponding fastening system (18).

[0103] Then, the movement of the conveyor substrate (2) is started, in this case the fixing element (19) on the left side being lowered and the fixing element (20) on the right side being lifted. At the same time, the supply roller (14) is activated, which begins to rotate on itself supplying a layer of printing material with controlled thickness on the conveyor substrate (2).

[0104] Once the layer of printing material has been supplied on the conveyor substrate (2), along a previously determined working length, the printing surface (3) moves upwards by means of the conveying module (4), being at a distance from the conveyor substrate (2) equal to the set of thicknesses already produced in the part plus the thickness of the new layer supplied on the conveyor substrate (2).

[0105] When the printing surface (3) is located in the position thereof, the printing material from the conveyor substrate (2) is irradiated in order to cure it in a certain way. Then, the printing surface (3) is separated by moving it downwards by means of the conveying module (4).

[0106] The movement of the conveyor substrate (2) resumes in the same direction as in the case of the material supply and the material collection module (31) is activated at the same time, which, by means of the spatula (33) enables the uncured material to be removed from the conveyor substrate (2), directing it towards the material collection tray (32) and, finally, sending it back to the reservoir (11).

[0107] FIG. 9 shows a schematic view of a second preferred embodiment of the machine of the invention, in which the conveyor substrate (2) is positioned in an O-shape. Thus, the fastening system (18) comprises a central and movable fixing element (34) and four rotating elements (27, 28, 35, 36), two upper rotating elements (35, 36) and two lower ones (27, 28).

[0108] The central and movable fixing element (34) of the fastening system (18) is located on linear guides (37) and holds the conveyor substrate (2) at two ends to the structure (1) at an upper level and parallel to the working surface (3). The fixing element (34) moves on the linear guides (37) alternately, in two directions, left and right, to produce a movement in the conveyor substrate (2).

[0109] In this case, the substrate (2) is connected to the central and movable fixing element (34) by means of two connecting bars (38, 39) that are fixed to the two ends of the substrate (2) by means of a clip, and they are connected to the fixing element (34) by means of two C-shaped fixing elements (40, 41).

[0110] Thus, from the central and movable fixing element (34), the conveyor substrate (2) extends in a horizontal direction towards a first rotating element (35), changes direction by resting on said first rotating element (35), and extends in a vertical direction, downwards, with a certain inclination towards a second rotating element (27), the substrate (2) resting on said second rotating element (27), changes direction once more and extends in a horizontal direction going across the working surface (3) towards a third rotating element (28), resting on this rotating element (28), changes direction and extends upwards in a vertical direction with a certain inclination, symmetrical to the downward inclination, and rests on a fourth rotating element (36) and extends in a horizontal direction to be held by a second end to the central and movable fixing element (34).

[0111] FIG. 10 shows a schematic view of a second preferred embodiment of the fastening system (18) of the invention. This figure shows a tensioning system (42) comprised by the machine, connected to the two upper rotating elements (35, 36). The tensioning system (42) is, in this case, a scissor-type mechanism (44) that enables the upper rotating elements (35, 36) to move closer to or away from each other through the movement of a central transverse spindle (43). Thus, the tensioning system (18) is compressed when placing the conveyor substrate (2), that is, the rotating elements (35, 36) are brought closer together, and once the substrate (2) is placed, they move away until the desired tension is reached, preferably until motor step losses are detected.