Method and system for secure connection in layer segment of cut layer additive part

Abstract

To provide methods and systems for secure connections in individual layer segments connected to each other from one end to the other end.SOLUTION: A method of manufacturing a part with a plurality of cut segments includes receiving a sheet of material with a machining apparatus, removing material with the machining apparatus to form a plurality of segments in the sheet of material, and forming complementary shapes in ends of two or more segments of the plurality of segments. The method further includes forming slots in the two or more segments, aligning the slots in the two or more segments to form a cavity, and inserting a connecting device to fill the cavity.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] Technical Field Aspects of the present disclosure relate to systems and methods for fabricating components. In some cases, aspects of the present disclosure relate to systems and methods for fabricating components (e.g., patterns, molds, and similar products) using techniques or processes similar to layered 3D printing processes. These techniques or processes can, at least in some embodiments, enable the production of lower cost molds or tools without the use of 3D printers. [Background technology]

[0002] background Generally, additive manufacturing techniques and processes involve the deposition of one or more materials to create net-shape or near-net-shape (NNS) objects, as opposed to subtractive manufacturing methods. While "additive manufacturing" is an industry standard term (ASTMF2792), additive manufacturing encompasses manufacturing and prototyping techniques known by various names, including freeform fabrication, 3D printing, and rapid prototyping / tooling.

[0003] Some additive manufacturing techniques use large-scale 3D printers capable of producing very large parts, molds, patterns, etc. These parts can be made from, for example, fiber-reinforced thermoplastic materials. One method for producing these parts utilizes a polymer extruder to produce a bead of molten thermoplastic material, which is then added sequentially so that the part is built one layer at a time. These layers can be modified and / or flattened into wider beads during the additive manufacturing process using devices such as pressure plates, rotors, etc. Using these methods, sometimes referred to as 3D printing, parts are made slightly larger than desired. After the part cools and hardens, it is machined to its final size and shape. The resulting part is generally a shell of a specific thickness and approximately the desired size and shape.

[0004] Another type of additive manufacturing can be referred to as "cut-layer" additive manufacturing. In some examples of cut-layer additive manufacturing, pieces can be cut from a porous material, layered on top of each other, and adhered together to create a part. In some cases, the part can be hollow and comprised of individual elements that are narrow beads that, when stacked together, form a shell or wall around the desired part's outline. In some approaches, the shell or wall is made of a porous material and infused with a catalyzed thermosetting liquid that hardens to create a rigid composite part reinforced with the porous material.

[0005] However, it may be desirable to fabricate parts from non-porous materials such as metals (e.g., aluminum). Examples of potential applications for such parts include industrial molds and tools for use in plastic molding processes such as thermoforming, blow molding, rotational molding, and reaction injection molding. Generally, aluminum molds for applications such as compression molds and injection molds are not suitable for long-term production, but may be desirable for prototyping and short-run sample production if the aluminum molds have an appropriate cost and can be produced in an appropriate timeframe.

[0006] One reason aluminum and other materials, while possessing desirable properties, are not used for at least some applications, such as molds and tooling, is that these relatively large parts require the use of large blocks of material and the time required to remove (e.g., machine) the excess material to create the desired mold cavity shape. This is especially true for large, deep parts, where more than half of the material must be removed to achieve the desired final part geometry.

[0007] Some parts, including tools, can benefit from structures with internal channels through which heated or cooled fluids can be circulated to control the tool's temperature during operation. However, machining these channels into a solid block of material requires significant time and specialized equipment, further increasing build time and costs. Also, in some cases, machining into the solid block from the outside may preclude the placement of these channels in certain areas of the mold. This can make it impractical or impossible to create channels in some locations in parts made with traditional additive manufacturing techniques.

[0008] Cut Layer Additive Manufacturing allows for the use of material in sheet form, and these sheets typically result in a lower cost per pound of final product compared to parts formed from one or more large blocks of the same material. Cut Layer Additive Manufacturing can be advantageous because it requires less material to be machined to produce the final product. Cut Layer Additive Manufacturing can also offer the ability to form heating and / or cooling channels in the cut sheets that cannot be easily machined in a solid block of material.

[0009] In certain applications, such as molds for plastics processing, it may be desirable for the surface of a cut layer structure, after assembly, to appear like a solid piece of material (such as metal) rather than a structure assembled from a series of individual parts. To facilitate assembly of parts in these applications, not only the individual layer segments but also the layer formed by these segments need to be securely connected. Summary of the Invention

[0010] overview Aspects of the present disclosure relate, inter alia, to methods and apparatus for manufacturing components by layering techniques. Each aspect disclosed herein can include one or more of the features described in connection with any of the other disclosed aspects. Objects of the present disclosure include, for example, methods for achieving tight connections between individual layer segments that are connected to each other end-to-end.

[0011] A method according to the present disclosure begins, for example, by cutting the ends of the layer segments that will be mated together. These ends can be cut into a V-shape or other shape to prevent the two mating ends from sliding relative to each other (e.g., side-to-side) when pulled tight. Following the formation of the shaped ends, holes can be drilled or milled into each of the mating ends of the layer segments. Slots can then be milled from the holes to each end of the layer segments so that the pairs of slots align congruently with each other when the ends of the two layer segments are attached end-to-end. This creates a non-slip connection.

[0012] To facilitate this connection, a connecting device having a shape (e.g., dumbbell-shaped) that matches the shape of the two through or blind holes can be used. The connecting device can include a portion shaped to match the slot connecting the two holes. The connecting device can taper from a larger upper profile to a smaller lower profile, in which case the lower portion fits easily (e.g., with a gap) into the dumbbell-shaped holes at the ends of the two layer segments, while the upper portion of the connecting device forms an interference fit. Thus, when the connecting device is pressed into the holes, the two layer segments fit together tightly, holding the two ends together with considerable pressure.

[0013] In one aspect, a method for manufacturing a part having a plurality of cut segments may include receiving a sheet of material with a machining device, removing material with the machining device to form a plurality of segments in the sheet of material, and forming complementary shapes on ends of two or more of the plurality of segments. The method may further include forming slots in the two or more segments, aligning the slots of the two or more segments to form a cavity, and inserting a connecting device to fill the cavity.

[0014] In another aspect, a method for manufacturing a part having a plurality of cut segments can include receiving a sheet of material with a machining device, removing material with the machining device to form a plurality of segments in the sheet of material, and forming a recessed edge extending from a face of a first of two segments. The method can further include forming a protruding edge having a shape complementary to the shape of the recessed edge, inserting the protruding edge into the recessed edge, and securing the protruding edge to the recessed edge.

[0015] In yet another aspect, a system for manufacturing a part having multiple segments can include a machining device configured to receive a sheet of material and a controller configured to generate commands to control the machining device. The controller can be programmed to cause the machining device to remove material to form a plurality of segments from the sheet of material, to cause the machining device to form complementary shapes on ends of two or more of the plurality of segments, and to cause the machining device to form slots in the two or more segments.

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary aspects of the present disclosure and, together with the description, serve to explain the principles of the disclosure. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of an exemplary material removal device (e.g., a CNC machine) operable to locate layers of sheet material according to one embodiment of the present disclosure. [Figure 2A] FIG. 1 is an enlarged perspective view of an exemplary layer segment having V-shaped tapered ends that interlock with each other, with cavities formed by holes and slots at each tapered end, according to an embodiment of the present disclosure. [Figure 2B] FIG. 1 is an enlarged perspective view of an exemplary layer segment having V-shaped tapered ends that interlock with each other, with cavities formed by holes and slots at each tapered end, according to an embodiment of the present disclosure. [Figure 3] 1 is a perspective view of an exemplary connection device with a bottom that is smaller than the cavity that houses the connection device and a top that is the same size as or slightly larger than the cavity. FIG. [Figure 4] 1 is a perspective view of an exemplary connecting device inserted into a cavity of two layer segments and drawing the layer segments tightly together. FIG. [Figure 5A] 1A-1C are enlarged perspective views of exemplary ply segments with rounded and straight ends, respectively. [Figure 5B] 1A-1C are enlarged perspective views of exemplary ply segments with rounded and straight ends, respectively. [Figure 6A] 10A-10C are enlarged perspective views of different exemplary cavities in different layer segments that can be used with a matching connection device to achieve a tight end-to-end connection. [Figure 6B] 10A-10C are enlarged perspective views of different exemplary cavities in different layer segments that can be used with a matching connection device to achieve a tight end-to-end connection. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present disclosure relates, inter alia, to methods and systems for fabricating different types of components by layering techniques. Specifically, the methods and systems described herein can be connected end-to-end to fabricate layers, achieving tight connections between individual layer segments.

[0019] In contrast to some manufacturing methods that involve machining a solid block of material, aspects of the present disclosure involve assembling a part, such as a mold blank, by stacking separate layer segments cut from a sheet of material. The material may be a solid, non-porous material, such as aluminum. In some aspects, a layered mold blank is produced, which approximately matches the desired size and shape of the final mold. The layered mold blank is then machined to its final size and shape. These procedures may produce parts that are built layer by layer and are similar in structure to traditional additively manufactured parts.

[0020] As shown in FIG. 1 , a cutting machine 11, such as a CNC router, can be used to cut layers from a sheet of material 12. A controller 60 can be incorporated into the machine 11 as described herein and / or can be part of a system for manufacturing a part. The controller 60 can be configured to generate commands that cause the machine 11 to remove material from the sheet 12 to form multiple layers, as also described herein. The machine 11 is configured to receive one or more sheets of material 12, where the one or more sheets 12 provide material for forming segments that, when assembled, form a complete part.

[0021] These layers can be assembled together to form a part, as opposed to a process in which layers are applied to each other during a printing process. The individual layers can be secured in place in various ways, such as by covering the assembled layers with a plastic (e.g., resin).

[0022] One or more layers of a part may include multiple individual layer segments. For example, a first layer may be formed by segments 13, 14, 15, and 16, a second layer may be formed by segments 17, 18, 19, and 20, and a third layer may be formed by segments 21, 22, 23, and 24.

[0023] In some embodiments, it may be difficult to secure the segments of a particular layer in a manner that allows plastic to be formed over the layer. Referring to Figure 2A, an exemplary approach to addressing these challenges includes machining corresponding shapes, such as matching tapers, into the ends of opposing segments.

[0024] 2A, layer segment 14 may be machined with cutting machine 11 to form complementary shapes including complementary surfaces, such as surfaces 38 and 40. These complementary shapes may include a tapered "V" shape having a recessed center that extends into the face (e.g., side edges) of layer segment 14 and protruding side edges of the face of segment 14.

[0025] By performing a machining process on the layer segments 15 in the machine 11, a mating or complementary "V" taper shape can be formed, resulting in a protruding center and recessed side ends. The ends of the segments 14 and 15 may be shaped so that, when connected, the ends of the segments 14 and 15 lock together, as shown in FIG. 2B. When abutted, as shown in FIG. 2B, the segments 14 and 15 are restricted from moving side to side relative to each other. While FIGS. 2A and 2B show exemplary tapers that form an angle (e.g., an approximately 90-degree angle measured from the two surfaces that form the legs of the "V"), other complementary shapes are also contemplated. It should also be understood that, when a "V" taper shape is used, the "V" taper shown in FIG. 2A is one example. Other examples of "V" tapers include a slight "V" taper formed by a larger angle (e.g., an obtuse angle formed by the legs of the "V"), or a deeper "V" taper formed by a narrower angle (e.g., an acute angle formed by the legs of the "V").

[0026] In at least some embodiments, first hole 25 and second hole 26 can be drilled or machined into the ends of layer segment 14 and layer segment 15. This can be done by removing material from above, using machine 11, for example, some distance from the point where the layer segments connect.

[0027] In addition to holes 25 and 26, which may be through holes or blind holes, one or more slots may be formed in segments 14 and 15. For example, a first slot 27 is formed at the end of segment 14 and a second slot 28 is formed at the end of segment 15. The width of slots 27 and 28 may be less than the diameter of holes 25 and 26. In some embodiments, the widths of slots 27 and 28 may be the same or approximately the same.

[0028] Slots 27 and 28 can be machined to extend from the ends of holes 25 and 26 to the ends of each segment 14 or 15. Thus, when two layer segments 14 and 15 are placed end-to-end and mated for assembly, as shown in FIG. 2B, slots 27 and 28 form portions of cavity 29 that, when aligned with one another, form a single continuous slot. Cavity 29 may include this continuous slot and holes 25 and 26 machined into the ends of layer segments 14 and 15. In the example shown in FIG. 2B, cavity 29 has a dumbbell shape formed by holes 25 and 26, which are wider than the continuous slot formed by slots 27 and 28.

[0029] 3, a connection device 30 can be formed for use with segments 14 and 15. In some configurations, connection device 30 can be constructed from the same material as layer segments 14 and 15, such as aluminum or other metal. However, if desired, connection device 30 can be formed from one or more different materials.

[0030] 3, the connecting device 30 may have the same general shape as the holes 25 and 26 and slots 27 and 28 formed between the layer segments 14 and 15 when the layer segments 14 and 15 are mated for assembly. As shown in the illustrated example, the connecting device 30 may have a barbell shape when viewed from above, with two generally circular sides 50 connected by a linear bridge 52.

[0031] In at least some embodiments, the connecting device 30 may have a tapered shape. This taper may be formed between the front and rear ends of the device 30. As shown in FIG. 3 , the device 30 may be tapered such that the rear end 31 is small, the front end 32 expands, and at least one wall is defined that tapers from the expanded end 32 toward the small end 31. Each end 31 and 32 may include a circular side 50 and a bridge 52 connecting the sides. The side 50 and bridge 52 of the rear end 31 of the small end may define a perimeter that is smaller than the corresponding perimeter defined by the side 50 and bridge 52 of the front end 32.

[0032] In some embodiments, the perimeter of connecting device 30 at bottom end 31 may be slightly smaller than the machined cavity 29 ( FIG. 2 ) between mating layer segments. Enlarged end 32 of connecting device 30 may have a perimeter that is approximately the same size as, or slightly larger than, machined cavity 29. This smaller perimeter of connecting device 30 may facilitate insertion of connecting device 30 into cavity 29. Side 50 of device 30 may be larger (e.g., diameter) than one or both of holes 25 and 26 at enlarged end 32. Additionally or alternatively, bridge 52 of enlarged end 32 may be larger (e.g., width) than one or both of slots 27 and 28.

[0033] For example, as shown in FIG. 4 , the connection device 30 can be pushed downward with sufficient force by a human or mechanical device (e.g., an assembly robot or other automated assembly system) to fully seat the connection device 30 within the two layer segments 14 and 15, securely attaching the segments 14 and 15. In some embodiments, the size of the enlarged end 32 may provide an interference fit between the cavity 29 and the connection device 30. In these embodiments, a significant downward force may be used to insert the connection device 30. Advantageously, slightly tapering the connection device 30 from end 32 to end 31 tends to pull the layer segments 14 and 15 together when the connection device is inserted into the cavity 29. This pulling force may be sufficient to eliminate any gaps that may exist between the segments 14 and 15.

[0034] While exemplary embodiments including connecting device 30 and cavity 29 are described above and illustrated in Figures 2A-4, variations on these embodiments are possible. For example, instead of providing a taper in connecting device 30, a taper can be machined into cavity 29 in layer segments 14 and 15, such that a lower end and an enlarged upper end are formed directly in segments 14 and 15. Thus, a taper may be present when viewing cavity 29 along the direction in which connecting device 30 is inserted into cavity 29. In these embodiments, a straight-walled connecting device 30 (i.e., a connecting device 30 without a taper between ends 31 and 32) may be used.

[0035] Additionally, although Figures 2A, 2B, and 4 illustrate an embodiment in which machine 11 forms "V" shaped ends, shapes other than a "V" can be used to form the ends of ply segments 14 and 15. Other shapes are possible, including the shapes shown in Figures 5A, 5B, 6A, and 6B.

[0036] As shown in FIG. 5A, in at least some embodiments, rounded ends may be used. These ends may include protruding end 44 and recessed end 42. Protruding end 44 may include a central protruding portion (the center of which is measured, for example, along the width of segment 19) facing recessed end 42. Recessed end 42 is recessed in its central portion (measured along the width of segment 17) and has protruding lateral ends. In some aspects, slots 27 and 28 may be formed at the deepest portions of the respective recesses and at the termini of the protrusions.

[0037] Some embodiments of the present disclosure include using device 30 without forming geometrically shaped joints at the ends of two or more segments. Rather, as shown in FIG. 5B , segments 21 and 23 may be formed with straight ends with flat surfaces 46 and 48, or other shapes without mating recesses and protrusions. Flat surfaces 46 and 48 may abut and contact (e.g., form a butt joint) when connecting device 30 is inserted into holes 25 and 26 and slots 27 and 28, preventing gaps from forming between ends 46 and 48.

[0038] In some embodiments, cavity 29 may be modified, although this involves modifying the protruding and recessed ends of the segments (e.g., by forming recessed end 42 and protruding end 44). For example, as shown in FIGS. 6A and 6B, the holes in cavity 29 may be formed in different shapes. As shown in FIG. 6A, holes 33 and 34 may be formed in ovals rather than substantially perfect circles. These ovals may be used with connection device 30 having similarly shaped (e.g., oval) rounded ends. As mentioned above, connection device 30 may have a tapered shape, but instead, holes 33 and 34 and / or slots 27 and 28 may be formed with a tapered shape.

[0039] In another example shown in FIG. 6B , holes may be formed as slots 35 and 36 in addition to slots 27 and 28. Slots 35 and 36 may be through holes or blind holes that intersect with slots 27 and 28, respectively. Slots 35 and 36 may have rounded ends to facilitate insertion of connecting device 30 and to avoid sharp edges or ends that may impede insertion of device 30. The openings formed by slots 35 and 36, like holes 33 and 34, can be used with connecting devices 30 of a matching shape. Suitable devices 30 have a tapered shape, and / or slots 35 and 36 and slots 27 and 28 have a tapered shape to facilitate an interference fit.

[0040] Each of the above-described aspects may be included in a method for manufacturing a part from a plurality of cut segments. As an example, the method may include receiving a sheet of material 12 with a machining device or cutting machine 11. The method may include removing material from the sheet of material 12 to form layer segments, such as segments 13-24 shown in FIG. 1. Additional material removal with machine 11 may form two or more segments 13-24 with complementary shapes at each end of the segments (e.g., as shown in FIGS. 2A, 2B, and 4-6B). Slots 27 and 28 may be formed by removing additional material (e.g., with machine 11) from each segment with a complementary shape.

[0041] The method of fabricating a part from the cut segments may also include aligning the slots by placing a pair of complementary shapes in contact with one another, which contact forms a cavity 29, which has a continuous shape defined by holes 25 and 26 and slots 27 and 28. A connecting device 30 may be inserted into cavity 29 to fill cavity 29 and prevent separation of the connected segments.

[0042] In some embodiments, the controller 60 may be configured to generate commands that cause the cutting machine 11 to perform at least a portion of the above-described method. For example, the controller 60 may be programmed to generate commands that cause a machining device, such as the machine 11, to remove material from the sheet of material 12 to form the segments 13-24 and the connecting device 30 described above.

[0043] It will be apparent from the foregoing detailed description that there are numerous variations, adaptations, and modifications to the present method and system that are within the purview of one of ordinary skill in the art to which the foregoing disclosure pertains. However, it is intended that all such variations that do not depart from the spirit of the disclosure be deemed to be within its scope as limited by the appended claims. [Explanation of symbols]

[0044] 13~24 segments 27 slots 28 slots 29 Cavity 30 Connection Device 42 concave end 44 Projecting end 52 Bridge

Claims

1. 1. A method for manufacturing a part having a plurality of cut segments, comprising: receiving a sheet of material at a machining device; removing material with the machining device to form a plurality of segments in the sheet of material; forming complementary shapes on ends of two or more segments of the plurality of segments; forming slots in the two or more segments; aligning the slots of the two or more segments to form a cavity; and inserting a connecting device to fill the cavity.

2. The method of claim 1 , wherein the connection device has wider sides compared to the width of a central portion of the connection device.

3. The method of claim 1 , wherein the connecting device includes a bridge connecting a pair of enlarged sides.

4. The method of claim 1 , wherein the connecting device has a wall that tapers from an enlarged end to an end that is smaller than the enlarged end.

5. The method of claim 1 , wherein the slots are formed in the ends of the two or more segments that form a butt joint.

6. The method of claim 1 , further comprising forming through holes in the two or more segments, the through holes directly connected to respective slots.

7. The method of claim 6 , wherein the through holes are formed at each end of the slot.

8. The method of claim 6 , wherein the through-holes have a generally circular or oval shape.

9. The method of claim 6 , wherein the through holes are formed as slot-shaped openings that intersect with the respective slots.

10. The method of claim 1 , wherein the complementary shape is a "V" taper.

11. 1. A method for manufacturing a part having a plurality of cut segments, comprising: receiving a sheet of material at a machining device; removing material with the machining device to form a plurality of segments in the sheet of material; forming a recessed end extending to a face of a first of said segments; forming a protruding end portion having a shape complementary to the shape of the recessed end portion; inserting the protruding end into the recessed end; and securing the protruding end to the recessed end.

12. The method of claim 11 , wherein the recessed end and the protruding end form complementary tapered shapes.

13. The method of claim 11 , wherein the recessed end and the protruding end form a complementary “V” shape.

14. The method of claim 11 , wherein the recessed end and the protruding end form complementary rounded shapes.

15. 1. A system for manufacturing a part having a plurality of segments, comprising: a machining device configured to receive a sheet of material; a controller configured to generate commands to control the machining device; The controller causing the machining device to remove material to form a plurality of segments from the sheet of material; causing the machining device to form complementary shapes on ends of two or more segments of the plurality of segments; causing the machining device to form slots in the two or more segments; A system that is programmed to perform

16. The system of claim 15 , wherein the controller is further programmed to form an enlarged portion at one or both ends of the slot of the two or more segments.

17. 16. The system of claim 15, wherein the controller is further programmed to cause the machining device to form a recessed end in one of the two or more segments and a protruding end in another of the two or more segments, the recessed end and the protruding end forming the complementary shape.

18. 20. The system of claim 17, wherein the controller is further programmed to cause the machining device to form the protruding end into a "V" shape.

19. The system of claim 17 , wherein the controller is further programmed to cause the machining device to form the protruding end into a rounded shape.

20. The system of claim 17 , wherein the controller is further programmed to form the slot through the protruding end and the recessed end.

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