Method and device for automating the layer-by-layer manufacturing of objects by using solid-solid additive manufacturing - Patents.com

Abstract

A method and apparatus for automating the layer-by-layer production of objects according to solid-solid additive manufacturing are provided. The apparatus (1) comprises a vacuum table (2) and at least one machining tool movably mounted above the table (2). The apparatus also comprises a pivoting station (4), which comprises a cross member (42), a support means (45) for a plate (M), and X and Y wedging means (21). The cross member (42) is longitudinally movable above the table (2) and vertically movable, and carries a gripping means (43) for the plate (M). The gripping means (43) is mounted so as to be rotatable about an axis parallel to the cross member (42). The support means (45) for the plate (M) is designed so that the plate can be gripped by the gripping means (43) on either of its two faces. The X and Y wedging means (21) are suitable for locating the plates (M), sets or sheets and for positioning them.

Description

Detailed Description of the Invention

[0001] The subject of the present invention is a method and an apparatus for the automation of the layer-by-layer production of objects by solid-solid additive manufacturing, such as known as Stratoconception®.

[0002] The so-called additive manufacturing process Stratoconception®, developed by the applicant, in its simplest version consists of digitizing the object to be manufactured, digitally breaking it down into a number of different complementary elementary layers, setting them together, then replicating these different layers by cutting and / or machining operations to obtain a number of sheets, and finally superimposing and / or juxtaposing, positioning, assembling and integrating said different sheets to replicate the object to be manufactured.

[0003] Additionally, depending on the complexity of the parts to be manufactured, it may be considered to add assembly elements, such as extensions or trigger guards, to the shapes produced during the manufacture of the sheets, with the intention of later removing them, so that one part can be indexed relative to another during assembly. Note that it may also be considered to use inserts that act as both locating pins and links between the sheets for indexing purposes.

[0004] Typically, the different sheets have the same thickness and are cut from one or more plates of a single material, and the placement and orientation of the different sheets on the plate is selected for optimization purposes to create the resulting set of sheets.

[0005] A further difficulty to note is that plates may not be dimensionally compliant due to inherent thickness variations, and although it is of course possible to use pre-calibrated plates or to re-calibrate the plates before use, this results in increased costs.

[0006] On the other hand, the joints created between the sheets during the gluing operation must also be taken into account, since their thickness, although calibrated during placement, can affect the final dimensions of the replicated object.

[0007] Depending on the object to be manufactured, its complexity, i.e. several different sheets, may lead not only to cutting plates, but also to carrying out 3D milling operations to create the designed and undercut parts, if necessary in conjunction with turning a set of sheets upside down.

[0008] Such manufacturing processes do not pose production problems if carried out in an artisanal way, but they do if they have to be industrialized and automated, as described in FR-A-2 789 188, which presents a layer-by-layer solid / solid additive manufacturing method, known as Stratoconception®, in an artisanal, even manual, version, without mentioning the automation of the manufacturing.

[0009] We all know that the transition from artisanal manufacturing to automation does not simply consist of replacing manual operations.

[0010] The subject of the present invention is therefore to provide a method that allows such an automation of the layer-by-layer production of objects according to solid / solid additive manufacturing, and also aims to eliminate any manual intervention.

[0011] A method for automating the layer-by-layer production of objects using solid / solid additive manufacturing is digitally decomposing the object along one or more axes and a thickness into a number of distinct sheets by digital slicing; optimally distributing the plurality of sheets as a set on a stock plate; calculating a plurality of trajectories of one or more tools for cutting and / or machining; digitally slicing the sheets and then micro-milling the front side of the sheets of the set in a finish; turning the set upside down; wedging, marking and positioning the set; micro-milling the backsides of the plurality of sheets in a set in a rough machining process; Extracting a first sheet of the set and subsequently displacing it in the so-called horizontal XY plane and angularly positioning it above the loading and finishing area; placing an adhesive on the first sheet; extracting a second sheet of the set, then displacing it along the XY plane, angularly positioning it, placing and maintaining it on the first sheet, and then repeating the bonding and extraction steps for each of the plurality of sheets not yet assembled; The present invention is characterized by comprising:

[0012] According to a further characteristic of the method according to the invention, a step of determining the nature, shape and arrangement of a number of construction elements inside or outside the object is interposed between the steps of digitally decomposing the object and optimally distributing them in a set.

[0013] According to a further feature of the method according to the invention, each operation of placing one sheet on another after adhesive application is followed by a step of micro-milling on the reverse side.

[0014] The purpose of this micromilling operation, in addition to finishing, is to remove excess joint material resulting from gluing and, above all, to correct defects related to lamination. This operation is carried out after the lamination of each sheet in order to readjust the dimensional parameters at each level. This is based on the knowledge that, for example, 3D machining the object once at the end of the lamination operation would probably be ineffective or even impossible.

[0015] Automated machines already exist that can perform some of the tasks for performing layer-by-layer solid / solid additive manufacturing.

[0016] Such an apparatus comprises a table, preferably of the vacuum type, and a number of machining tools mounted for displacement above the table, for example via a cross member, the cross member being movable longitudinally above the table and comprising a number of machining tools movable along the cross member, such movements being managed by a central processing unit.

[0017] However, such devices are of limited use and do not allow the implementation of the entire process according to the invention.

[0018] The subject of the present application is therefore also a device which overcomes these deficiencies and makes it possible to carry out the method according to the invention.

[0019] An apparatus according to the invention allowing the automation of the layer-by-layer production of objects according to the solid / solid additive manufacturing method, comprising: a machining table held by vacuum; At least one machining tool displaceably mounted above the table; Equipped with The apparatus further comprises a rotation station, the rotation station comprising: a cross member movable longitudinally and vertically above said table, carrying a plate gripping means mounted for rotational movement about an axis parallel to said cross member; a support means for the plate, designed to enable the plate to be gripped by the gripping means on either one of its two faces; - wedging means in the X and Y directions, which may allow marking and positioning of plates, sets or sheets; The present invention is characterized by comprising:

[0020] It should be noted that while this pivot station is best suited for inverting sets, it could just as well be configured to invert sheets if desired, just as it could simply invert plates.

[0021] According to a further feature of the device according to the invention, the cross member carried by the gripping means of the pivoting station is movably mounted on two benches, while a tool holder is movably mounted along the movable cross member on the same two benches.

[0022] According to another further characteristic of the device according to the invention, the tool holder can be provided with means for gripping the cut part, as well as adhesive means or the like.

[0023] According to a variant of the device according to the invention, machining means can also be applied to the tool holder.

[0024] In fact, each of the existing devices comprises, as already mentioned, a table and a number of machining tools displaceably mounted above said table. It is possible to adapt these existing tables for the purpose of adapting them to the invention. Thus, to these existing tables capable of cutting and machining plates to obtain sets, a pivoting means is added on the one hand, as well as a tool holder and a number of tools for gripping and gluing the parts coming from the set.

[0025] In systems that do not constitute an adaptation to an existing system, the tool holder is also configured to carry cutting and machining tools.

[0026] According to another further characteristic of the device according to the invention, it further comprises cleaning means for the table, associated with the tool holder.

[0027] According to another further feature of the device according to the invention, the device comprises an assembly area, which comprises a loading table associated with an elevator capable of maintaining the object to be manufactured at a height that depends on the height of the machining table.

[0028] According to another further characteristic of the device according to the invention, the assembly area comprises means for clamping the object against the placement table during assembly and after gluing, which means cooperate with the lift of the table to perform the pressing of the object.

[0029] According to another further characteristic of the device according to the invention, said support means for a plate are retractably mounted on said machining table.

[0030] The advantages and features of the method and device according to the invention will become more apparent from the following description taken in conjunction with the attached drawings which represent several non-limiting embodiments thereof. [Brief description of the drawings]

[0031] [Figure 1] 1 shows a schematic perspective view of the different steps of building an object using the method according to the invention; [Diagram 2] 1 shows a schematic perspective view of the different steps of building an object using the method according to the invention; [Diagram 3] 1 shows a schematic perspective view of the different steps of building an object using the method according to the invention; [Figure 4] 1 shows a schematic perspective view of the different steps of building an object using the method according to the invention; [Diagram 5] 1 shows a schematic perspective view of the different steps of building an object using the method according to the invention; [Figure 6] 1 shows a schematic perspective view of the different steps of building an object using the method according to the invention; [Figure 7] 1 shows a schematic perspective view of an apparatus according to the present invention; [Figure 8] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 9] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 10] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 11] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 12] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 13] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 14] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 15] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 16] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 17] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 18] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 19] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 20] 1 shows a schematic perspective view of an apparatus for carrying out the method according to the invention in various successive steps; [Figure 21] 1 shows a schematic perspective view of a variant of the device according to the invention; [Figure 22] 1 shows a schematic perspective view of another variant of the device according to the invention; [Diagram 23] FIG. 2 shows a schematic perspective view of another variant of the device according to the invention. [Figure 24] 2 represents a schematic perspective partial view of this same variant of the device in a particular configuration of use. [Diagram 25] 2 represents a schematic perspective partial view of this same variant of the device in a particular configuration of use. [Figure 26] 2 represents a schematic perspective partial view of this same variant of the device in a particular configuration of use. [Figure 27] 2 represents a schematic perspective partial view of this same variant of the device in a particular configuration of use. [Figure 28] 2 represents a schematic perspective partial view of this same variant of the device in a particular configuration of use. [Figure 29] 2 represents a schematic perspective partial view of this same variant of the device in a particular configuration of use. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] With reference to FIG. 1 it is possible to see three steps of preparing a plate of material M for the layer-by-layer production of an object using a solid / solid additive manufacturing method such as that known as Stratoconception®.

[0033] According to the method of the invention, the object to be replicated is previously digitally decomposed into different sheets along one or more axes, but in this example only one axis, and along the thickness. These sheets are arranged as a set P on a plate M, while multiple trajectories of one or more tools for cutting and machining are defined.

[0034] In FIG. 1, step A corresponds to slicing and micro-milling the front side R of plate M in 3D finishing, step B corresponds to flipping plate M upside down to expose the back side V to the tool, and step C corresponds to micro-milling a set of back sides of multiple sheets, in this example five sheets S1, S2, S3, S4, and S5, in 2D roughing.

[0035] In FIG. 2, sheet S1 is extracted from set P and positioned while undergoing 3D finishing micro-milling and adhesive application to its upper edge.

[0036] In FIG. 3, sheet S2 is removed from set P and placed, positioned and assembled to sheet S1 followed by 3D finish micro-milling of the entire sheet and application of adhesive to the top edge of sheet S2.

[0037] In FIG. 4, sheet S3 is removed from set P and placed, positioned and assembled to sheet S2, followed by micro-milling the entire assembly, removing joint excess in 3D finishing and applying adhesive to the top edge of sheet S3.

[0038] In FIG. 5, sheet S4 is removed from set P and placed, positioned and assembled to sheet S3, followed by micro-milling the entire assembly, removing excess material at the joints in a 3D finish, and applying adhesive to the top edge of sheet S4.

[0039] Finally, in FIG. 6, sheet S5 is extracted from set P, placed and assembled to sheet S4, and then subjected to 3D finish micro-milling in its entirety to obtain object O.

[0040] It should be noted that at each stage, micro-milling also makes it possible to correct defects along the so-called vertical Z-axis, perpendicular to the XY plane, associated with potential variations in the thickness of each plate and joint.

[0041] With reference now to FIG. 7, there can be seen a device 1 according to the invention, making it possible to automatically carry out the method described above.

[0042] The apparatus 1 comprises a table 2, preferably a vacuum table, and a Cartesian gantry 3, which comprises two benches 30 and 31 adjacent to the table 2 laterally and longitudinally. A movable cross member is longitudinally movable on the Cartesian gantry 3, along which a tool holder 33 is movably mounted. Meanwhile, at one end of the table 2, a number of tools 34 intended to be applied to the tool holder 33 are stored.

[0043] It should be noted that the representation of the device is not limiting and the device may for example be designed such that the longitudinal movement is performed at the level of the base.

[0044] The device 1 also comprises a loading / swiveling station 4 cooperating with the two benches 30 and 31, comprising two transport parts 40 and 41 displaceable on the benches 30 and 31 respectively, and a cross member 42 movable up and down on the transport parts 40 and 41 and pivotable, carrying a gripping means 43. The swiveling station 4 also comprises a console 44 arranged at the end of the table 2 opposite the side on which the tools 34 are stored, the console 44 essentially comprising two brackets 45 spaced apart from each other to form a central space through which the gripping means 43 can pass.

[0045] In an alternative arrangement, the two brackets 45 can be replaced by a number of fork tines 46 that are retractable within the table 2, as shown in FIG.

[0046] Now, with reference to FIGS. 8 to 19, each step of the manufacturing method carried out using the apparatus 1 will be described.

[0047] In FIG. 8, the gripping means 43 has removed a material plate M from storage for placement on the table 2, the positioning in the so-called horizontal XY plane being achieved in this example by pressing and wedging it against a number of studs 21.

[0048] In FIG. 9, to create the set P, the front side R of the plate M is sliced ​​using a tool 34 and machined in a 3D finish.

[0049] Figures 10 to 14 relate to the upside-down turning of the set P. In Figure 10, the plate M is gripped by the gripping means 43, then in Figure 11 it is placed with its back side V down on the console 44, then in Figure 12 the gripping means 43 is positioned below the plate M between the brackets 45 in order to grip the plate M with its back side V, and finally in Figure 13 the plate M is turned upside-down and placed with its front side R down on the table 2, as shown in Figure 14.

[0050] What is noteworthy, as can be seen in FIG. 13, is that during the stage of inverting the plate M, cleaning of the table 2 is performed during the masking period, with the tool holder 33 holding a cleaning means 35, such as a scraper or vacuum cleaner, which moves over the surface to push or suck machining residues off the table 2, in this example into a container 20.

[0051] In FIG. 15 the back side V of plate M is machined in a 2D rough machining, while in FIG. 16 layer S1 is removed from set P and in FIG. 17 placed on table 2 alongside plate M in the placement / lamination area.

[0052] It should be noted that the placement / lamination and machining areas shown in the figures may be interchangeable, as shown for example in Figure 22. In Figure 18, sheet S2 is removed from the set and placed alongside sheet S1, while in Figure 19, sheet S3 is removed from the set and placed on top of the machined sheets S1 and S2, which are then glued together.

[0053] In FIG. 20 the finished object O can be seen whilst the tool holder 33 and cleaning means 35 expel the residues.

[0054]

[00113] Referring now to Figure 21, a variation of the device according to the present invention, and more particularly an application to an existing device, can be seen.

[0055] The existing apparatus comprises a table 5 associated with a movable gantry 6 having two lateral struts 60 and 61 movable along the table 5 and a cross member 62 connecting them, the cross member 62 therefore being movable above the table 5 and also movable along the cross member 62 a tool holder 63 capable of gripping a machining tool 64 stored at the end of the table 5.

[0056] According to the invention, the existing table 5 is complemented by the addition of a gantry 3 and a swivel station 4 in order to be able to reproduce the method according to the invention. The gantry 3 comprises two benches 30 and 31 and a movable cross member 32 intended to move a tool holder 33. The tool holder 33 is dedicated to the tasks of gripping, gluing and pressing the sheets as well as cleaning the table 5. The swivel station 4 comprises two transports 40 and 41, a cross member 42, a gripping means 43 and a console 44.

[0057] In the embodiment shown, the device is externally associated with a machining station 7, which is capable of carrying out finishing operations, i.e., but not limited to, removal of extensions or trigger guards used for indexing.

[0058] It should be noted that station 7 can advantageously be replaced by a tool holder with two rotation axes for machining in five axes, or by associating a machining tool with the tool holder 33 via a bi-rotary head. Such an arrangement thus makes it possible to integrate all functions in the same device.

[0059] 22, another variation can be seen, namely a variation of the device shown in FIG.

[0060] The machine includes the addition of a further movable cross member 8 with associated tool holder 80 dedicated to gluing and handling multiple sheets for assembly, allowing separation of the machining / cleaning and gluing / lamination functions. This separation allows for more efficient processing during masking.

[0061] Referring now to FIG. 23 and to FIGS. 24, 25, 26, 27, 28 and 29, one can see a variant of the device making it possible to carry out the method according to the invention automatically, in which the various stations dedicated to one or more tasks are designed differently from those described above.

[0062] And in FIG. 23, which shows the device as a whole, it can be seen that it comprises a table 2, a mobile gantry 6 with a tool holder 63, a loading / rotating station 4 for several plates M, consisting of a mobile gantry with two mobile columns 47 between which a gripping plate 48 can be moved, and finally an assembly area 9 dedicated to placing the objects to be manufactured.

[0063] As can be seen in more detail in Figures 24 and 25, the assembly area 9 comprises a loading table 90 which is associated with a lift so that the object being loaded can be lowered progressively, so that the last assembled sheet can always be at the same level as the machining table 2.

[0064] Furthermore, the mounting table 90 cooperates with a number of lifting studs 91 which can penetrate the mounting table 90 through a number of holes 92 so as to allow extraction of the assembled object.

[0065] 26, it can be seen that the loading table 90 can be associated with its elevator and with the gripping plate 48 of the loading / rotating station 4 to facilitate a post-gluing pressing operation.

[0066] The gripping plate 48 is then turned upside down onto a stack of freshly glued sheets (not shown) placed on a loading table 90, while a number of flanges 93 included in the assembly area clamp the gripping plate 48 at the periphery of the loading table 90, while the loading table 90 associated with its elevator presses the stack from below up.

[0067] Advantageously, this pressing force is received by a number of flanges 93 and not by the gantry of the loading / rotating station 4 .

[0068] 27 and 28, it can be seen that the table 2 incorporates a fork 22 which can be withdrawn from the table 2 to lift a plate M (not shown) after it has been machined on its front side, thereby allowing a gripping plate 48 to pass underneath to grip the plate M by its back side, which is not machined, with a view to turning the plate M upside down. Gripping by the back side, which is not machined, makes it easier to grip the plate M.

[0069] With reference to FIG. 29, it can be seen that the gantry 6 is equipped with a gripping section 65 having three gripping points 66, and is capable of gripping a plurality of sheets in a very stable manner.

[0070] The device shown in these figures is of a more compact and rigid design, yet is capable of carrying out the method of the present invention in the same manner as the devices described above.

Claims

1. 1. An apparatus allowing the automation of the layer-by-layer production of an object using solid / solid additive manufacturing, the apparatus comprising: a machining table (2;5) maintained by vacuum; at least one machining tool displaceably mounted above the machining table; Equipped with The apparatus further comprises a turning station (4), which turning station a cross member (42) movable longitudinally and vertically above said machining table (2; 5), carrying gripping means (43; 48) for a plate (M) mounted for rotational movement along an axis parallel to said cross member (42); a support means (45; 46; 22) for the plate (M) designed to enable said plate (M) to be gripped by said gripping means (43) on one of its two faces (R, V); Wedging means (21) in the X and Y directions, which may allow the marking and positioning of plates (M), sets (P) or sheets (S), Equipped with the cross member (42) carrying the gripping means (43) of the swivel station (4) is movably mounted on two benches (30, 31), while a tool holder (33; 80) is movably mounted along a movable cross member (32; 8) on the same two benches.

2. 2. Apparatus according to claim 1, wherein said gripping means (48) of the plate (M) are carried by two movable columns (47).

3. 3. Apparatus according to claim 1 or 2, wherein the tool holder (33; 80) is provided with means for gripping the cut part as well as with adhesive means.

4. 4. Apparatus according to any one of claims 1 to 3, wherein machining means (34) are also applicable to said tool holder (33).

5. 5. Apparatus according to any one of the preceding claims, further comprising cleaning means (35) for the machining table (2; 5), applicable to the tool holder (33).

6. 6. An apparatus according to any one of claims 1 to 5, comprising an assembly area (9) comprising a loading table (90) associated with a lifting device capable of maintaining the object (O) to be manufactured at a height dependent on the height of the machining table (2).

7. 7. The device according to claim 6, wherein the assembly area comprises means (93) for clamping the object (O) against the placing table (90) during assembly and after gluing, said means cooperating with the lift of the placing table (90) to perform pressing of the object (O).

8. 8. Apparatus according to claim 6 or 7, wherein the support means (45; 46) for the plate (P) are retractably mounted on the machining table (2).

9. A method for automating layer-by-layer manufacturing of the object using solid / solid additive manufacturing, using an apparatus according to any one of claims 1 to 8, comprising the steps of: - digitally decomposing said object along one or more axes and a thickness into a number of different sheets (S, S1, S2, S3, S4, S5) by digital slicing; Optimally distributing the plurality of different sheets (S, S1, S2, S3, S4, S5) as sets (P) on a stock plate (M); - calculating a plurality of trajectories of one or more tools for cutting and / or machining; digital slicing of the plurality of different sheets (S, S1, S2, S3, S4, S5) followed by micro-milling in finishing the front side of the plurality of different sheets (S, S1, S2, S3, S4, S5) of the set (P); turning the set (P) upside down; wedging, marking and positioning the set; micro-milling the backsides of the different sheets (S, S1, S2, S3, S4, S5) in a set in a rough machining process; Extraction of a first sheet (S1) of said set (P) followed by displacement in the so-called horizontal XY plane and angular positioning of said first sheet (S1) on the loading and finishing area; placing an adhesive on the first sheet (S1); extracting a second sheet (S2) of said set (P), then displacing it along said horizontal XY plane, angularly positioning said second sheet (S2), placing and maintaining it on top of said first sheet (S1), and then repeating the bonding and extraction steps for each of said different sheets not yet assembled; A method for providing the above.

10. 10. The method of claim 9, wherein a step of determining the nature, shape and location of a plurality of construction elements inside or outside the object is interposed between the steps of digitally decomposing the object and optimally distributing them in sets.

11. 11. The method according to claim 9 or 10, wherein each operation of placing one sheet (S, S1, S2, S3, S4, S5) on another sheet after the application of adhesive is followed by a step of micro-milling on the reverse side for the purposes of finishing, removing excess material at the joints due to the adhesive and correcting defects related to the stacking.

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