Method of manufacturing an article

Abstract

A method for manufacturing an article includes the steps of providing a base element, providing a plurality of section bars, and fixing the section bars to a surface of the base element, the method further including the steps of defining, by one or more of the section bars, a plurality of restraining elements effective along an axis perpendicular to the base element, and applying a filler material onto the base element at least at one engagement portion cooperatively defined between the surface and at least one of the restraining elements.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a semi-finished article.

[0002] In other words, the present invention relates to the technical field of manufacturing processes aimed at creating support base parts in the form of semi-finished products that can be defined as "standard articles" in the language used for the present invention. Such articles can be used in both the architectural and industrial sectors (and in some subsectors of the latter) for the construction of complex articles such as structural elements and frames. [Background technology]

[0003] In the prior art, it is well known to use a support base, which may be thick and have various shapes, after which a filler material is deposited, which, after removal operations to adjust its shape and size, makes it possible to obtain the final article.

[0004] In particular, a filler material is deposited onto this base portion by an additive manufacturing (or overmolding or sintering) process. For example, U.S. Patent No. 4,031,279 discloses a method for constructing a lightweight structural member that includes an assembly of metal strips arranged in a parallel relationship with the ends of the strips on opposite sides of the assembly. The ends of the strips on one side of the assembly can be folded to provide a smoother, continuous work surface. Point-to-point nodal bonding of linear and nested foils with adjacent strips on the opposite side of the assembly can be utilized to facilitate handling and processing and to provide lateral support. Chinese Patent Publication No. 110424623 also describes a steel composite shear wall with staggered honeycomb partition plates and its manufacturing method. The steel composite shear wall comprises two parallel-arranged outer steel plates and two honeycomb partition plate groups symmetrically arranged between the two outer steel plates, the honeycomb partition plate groups being perpendicular to the outer steel plates. The honeycomb partition plate groups are composed of a plurality of horizontally arranged partition plates, each with a group of honeycomb holes evenly spaced vertically, with the honeycomb holes formed in two adjacent partition plates being staggered. Each partition plate is composed of two partition veneers welded together, each with a group of semi-honeycomb openings evenly spaced vertically. Furthermore, U.S. Patent No. 3,368,314 discloses a heat shield comprising a brazed metal honeycomb panel base structure and an open-faced metal honeycomb core brazed to one facing sheet of the panel. The cells on the open face of the honeycomb core are provided with circumferential flanges by passing the honeycomb core through successive spaced rollers, each successively approaching the core with each pass, while supporting the wax to its final height. A fibrous potassium titanate slurry or paste is applied with a trowel to the interior and top of the flanged honeycomb core, strengthening it and holding it to the base structure through the core's flanges. However, the prior art documents cited herein do not have the features of the present invention.

[0005] Unfortunately, in the prior art it has been found that the filler material does not adhere properly to the base, and to overcome this drawback it is known to use honeycomb panels, i.e. panels comprising pairs of plates and a honeycomb structure interposed between the plates.

[0006] Honeycomb panels can be used in a wide range of applications due to their unique design, which makes them highly resistant to impacts, cracks and loads (in one direction), while being lightweight, easy to handle and install.

[0007] These panels, being lightweight and resistant due to their honeycomb structure, can be used in both the architectural and industrial sectors to construct complex articles such as structural elements and frames.

[0008] In particular, one of the plates is milled and the filler material is supplied between the honeycomb structures through the access holes obtained by milling. The material thus deposited between the cavities sinks below the upper plate and can no longer escape. Unfortunately, the honeycomb structure (which may be made of a plastic material, for example) is fixed to the plate (which is generally made of metal) by gluing.

[0009] By adhering a honeycomb structure to a surface, the fixation becomes entirely dependent on the shear or tear properties of the adhesive, which is likely to last only within a narrow temperature range, outside which even short periods of time will result in permanent loss of properties due to component slippage or degradation of adhesive properties.

[0010] On the other hand, welding a honeycomb structure to a surface would subject the inner part of the sandwich to thermal stresses that could compromise the interface between the cavity and the encasing plate, an effect that cannot be verified or quantified from a "predictive" perspective.

[0011] Alternatively, choosing mechanical restraint (e.g. bolting a honeycomb structure to a surface) may run the risk of severing functional components performing "critical" load-bearing / structural functions within the panel, or more generally interrupting its structural continuity.

[0012] The aforementioned joining methods therefore limit the performance and choice of materials deposited, as the connections between the components of such articles can deteriorate and the entire structure can collapse. Summary of the Invention

[0013] Therefore, the technical problem of the present invention is to provide a method for manufacturing an article, which is able to overcome the drawbacks of the prior art.

[0014] It is therefore an object of the present invention to provide a method for manufacturing an article that reduces manufacturing costs, allows for the use of a wider range of materials, and thereby prevents the filler material from "slipping" from the base.

[0015] The stated technical problem and object are substantially achieved by a method for manufacturing an article, which method comprises the technical features set forth in one or more of the appended claims. The dependent claims correspond to possible embodiments of the invention.

[0016] According to the present invention, a method for manufacturing an article, in particular a method for manufacturing a semi-finished article, is presented.

[0017] The method is carried out by providing at least one base element (preferably a layer element) and at least a plurality of section bars.

[0018] The method further includes securing section bars to one surface of the base element and defining a plurality of restraining elements along vertical axes perpendicular to the layered element by one or more of the section bars.

[0019] Finally, the method preferably includes applying, by an additive manufacturing process, a filler material onto the layer element supporting the constraining element.

[0020] According to one aspect of the invention, the filler material is applied to at least one engagement cooperatively defined between the surface and at least one of the restraining elements.

[0021] Preferably, the base element is made of metal.

[0022] Preferably, the base element has a layered or curved shape.

[0023] Preferably, the section bar is made of metal.

[0024] Preferably, the base element defines a smooth base portion.

[0025] Preferably, the section bars are arranged on the base element so as to define a grid which is subsequently welded to the base element.

[0026] Preferably, the section bar defines a series of beveled, riveted or form-welded metal strips to create undercuts for defining the aforementioned restraining elements.

[0027] Preferably, the section bars define a series of metal strips fitted into grooves cut into the base element.

[0028] Preferably, the section bar is defined by a preformed foam that is welded to or fabricated on the base element.

[0029] Preferably, the step of fixing the section bar to the base element is performed by welding or sintering the section bar.

[0030] Preferably, the base element is cut to form a plurality of grooves in said base element, and the fixing step is performed by fitting the section bars into the respective grooves.

[0031] Advantageously, the base element has a morphological and structural function.

[0032] Advantageously, the method is cost-effective compared to existing manufacturing methods of the prior art.

[0033] Advantageously, the restraining element prevents the filler material from peeling off from the layer element.

[0034] Advantageously, the particular structure made of the base element, section bar and restraining element, as well as the materials from which the different components are made, make it possible to function with different filling materials and therefore at temperatures different from those available in the prior art.

[0035] According to a further aspect of the present invention there is provided a semi-finished article made or capable of being made by the above manufacturing method.

[0036] Further features and advantages of the invention will become more apparent from the illustrative, and therefore non-limiting, description of an embodiment of a method for producing a semi-finished article. [Brief explanation of the drawings]

[0037] The following description refers to the accompanying drawings, which are provided for purposes of illustration only and not limitation. [Figure 1] 1 is a schematic representation of a semi-finished article obtained by the method object of the invention; [Figure 2A] FIG. 1 is a schematic diagram of an alternative embodiment of the article. [Figure 2B] 2B is a schematic diagram of steps of the method of the present invention with reference to the embodiment of the article of FIG. 2A. [Figure 3] 3 is a schematic diagram of a further embodiment of a semi-finished article. [Figure 4] FIG. 10 is a schematic diagram of components of a further embodiment of a semi-finished article. [Figure 5] 3 is a schematic diagram of a further embodiment of a semi-finished article. DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention relates to a method for manufacturing a semi-finished article 1 (in other words, the method aims to provide a semi-finished or finished article), which method is carried out by providing a base element 2 comprising a surface 2a (e.g., positioned to be the "upper" surface in the accompanying figures, but which can be any surface oriented in any way according to the needs at the time).

[0039] The base element 2 can be in the form of a flat or curved layer element, but more generally the base element 2 can have any shape suitable for obtaining the final semi-finished article 1 .

[0040] The base element 2 may for example be made of metal or other material, so that the method may advantageously comprise a first step in which a metal base part is provided.

[0041] The base element 2 has a smooth surface 2a (or in any case has a predetermined surface roughness by suitable surface machining, also using the method), which is suitable for receiving the remaining structural components provided by the invention in an engaging manner with the required degree of restraint reaction occurring. For this purpose, the method also includes providing a plurality of section bars 3.

[0042] The section bar 3 is to be understood as a wall or a straight or curved (e.g. sinusoidal) element with a constant or variable cross section. According to a further embodiment of the invention, the section bar 3 may also be understood as a foam (e.g. a so-called "metal foam").

[0043] In general, the section bar 3 according to the invention is any element having a certain shape or length suitable for producing the article 1 .

[0044] According to the present invention, the section bars 3 may be arranged so that they define grid elements that "interconnect" (or cross each other to form a matrix pattern), as shown, for example, in the embodiment of Figures 2A and 2B.

[0045] The section bars 3 can be arranged to define a honeycomb structure having any topology and / or spatial shape according to the needs of the time. By way of non-limiting example, the honeycomb structure can have a plurality of spherical, i.e. spherical, hemispherical or essentially spherical cavities.

[0046] In other words, different shaped section bars 3 can be connected together or side by side to define a particular shape.

[0047] In operation, the step of providing the section bars 3 defines a plurality of containment cells 3 a. The term "containment cell" 3 a is therefore understood as a portion of the "empty" space defined between the various section bars 3, each containment cell 3 a therefore having a parallelepiped or cylindrical shape or any other shape defined by the arrangement of the section bars 3.

[0048] The method further comprises the step of fixing a section bar 3 to the upper surface 2a of the layer element 2, which fixing thus defines together with the base element 2 the bottom of each containment cell 3a.

[0049] The method also includes a step of fixing the section bars 3 to the base element 2 by interlocking, welding or sintering, for example this step of fixing the section bars 3 to the base element 2 is carried out by welding the section bars 3 to the upper surface 2a of the layer element 2 (in other words the method steps described so far make it possible to obtain a grid welded to a smooth base part).

[0050] In one embodiment of this method, a step of cutting the base element 2 to create a plurality of grooves in its surface 2a can be provided. In this way, the step of fixing the section bars 3 to the layer element 2 is carried out by fitting the section bars 3 into respective grooves defined in its upper surface 2a (thus, in this embodiment, an article 1 is produced that is defined by a series of metal strips fitted into grooves cut in the base element 2).

[0051] According to the method, following the cutting and fitting step, a step of welding the section bar 3 to the base element 2 can be provided. If the section bar 3 is defined by foam, the foam can be pre-formed and welded or can be made directly on the base element 2.

[0052] The method further comprises defining, by one or more of the section bars 3, a plurality of restraining elements 4 along a vertical axis "Z" transversely, e.g. perpendicular to, the base element 2. In this way, the restraining elements 4 are thus effective at least along the vertical axis "Z", in other words the method comprises providing restraining elements 4 which have the function of retaining the filler material 6, as will become clearer below.

[0053] To this end, the method comprises creating a cooperatively defined engagement between the surface 2 a and at least one of the restraining elements 4, such that the restraining element 4 defines a retention effect and / or function along an axis perpendicular to the upper surface 2 a of the base element 2.

[0054] In a possible embodiment of the present invention, the step of defining a plurality of restraining elements 4 is carried out by locally deforming one or more section bars 3, for example (but without being limited thereto), the deformation of the section bars 3 is carried out by drawing, or indenting, or bending, or calendaring said section bars 3.

[0055] Alternatively, the step of defining the plurality of restraining elements 4 is performed by molding the section bar 3 to create undercuts. For example, FIG. 5 shows possible shapes of the section bar 3 for creating restraining elements 4 under which the filler material 6 can penetrate and then be held. For example, the section bar 3 can be molded to define T-shaped or inverted L-shaped restraining elements. Alternatively, the section bar 3 can be molded to have an "accordion" shape, or can be embossed or characterized by a surface (along the vertical axis "Z") that exhibits protrusions whose size is less than half the distance between one section bar and the other and greater than 0.5 mm, i.e., in the range of the shrinkage of the polymer during cooling, and these protrusions function as restraining elements.

[0056] The restraining element 4 may be defined at the top of the section bar 3 (i.e. the most distal part of the section bar 3 relative to the base element 2) or at the middle part of the section bar 3 (i.e. the part interposed between the surface 2a and the most distal part), i.e. along a vertical surface as described in the paragraph above.

[0057] In other words, the restraining element 4 is made by riveting the section bar 3 together so that a portion is formed which intercepts a vertical axis "Z" perpendicular to the upper surface 2a.

[0058] The aforementioned step of defining a plurality of restraining elements 4 may be performed by defining one or more holes in at least one section bar 3. In other words, the method involves creating through holes in one or more section bars 3, such that the "channels" thus created define restraints along axes perpendicular to the upper surface 2a.

[0059] When these holes are present, the filler material penetrates into the through holes and prevents the remaining material deposited within each containment cell 3a from moving along the vertical axis "Z".

[0060] According to a further possible embodiment of the method, the step of defining a plurality of constraint elements 4 is performed by arranging one or more section bars 3 at a predetermined inclination angle "A" relative to the surface 2a. In other words, the inclined section bars 3 define the constraint elements 4 by intercepting the vertical axis "Z".

[0061] According to one aspect of the invention, the section bars 3 can be inclined (with respect to the normal direction emerging from the surface 2a) to facilitate the insertion of filler material. In this geometric / topological possibility, the inclined section bars 3 can also be arranged alternately with non-inclined section bars 3 (thus parallel to the vertical axis "Z") along the extension direction of the base element 2.

[0062] Quantitatively speaking, the inclined section bar 3 may be inclined at an angle comprised between 45° and 90° relative to the base element 2 (i.e. relative to the vertical axis "Z").

[0063] As regards the step of defining a plurality of restraining elements 4, this may be performed by intersecting the section bars 3 with a plurality of inserts 5 fixed to the top or middle of each section bar 3, as shown by way of example in Figure 4. The inserts 5 may be fixed before or after the step of welding the section bars 3 to the base element 2 (the accompanying figure shows by way of example that the inserts 5 give the section bars 3 a substantially T-shaped shape, each insert 5 intercepting the vertical axis "Z").

[0064] Each confinement cell 3a contains at least one restraining element 4, and in this respect the step of defining the restraining element 4 may be a combination of the steps described above (in other words, a single article 1 may exhibit restraining elements 4 created by deformation, bevelling or perforation of the section bar 3 and / or the addition of inserts 5).

[0065] The method further comprises applying, preferably by an additive manufacturing process or an overmolding process, a filler material 6 onto the base element 2 bearing the constraining elements 4. The filler material 6 is applied to the engagement jointly defined between at least the surface 2 a of the base element 2 and at least one of the constraining elements 4.

[0066] In other words, the filling material 6 (which may be, for example, a polymer material) is deposited in the confinement cells 3a and penetrates into the constraining elements 4 (if they are in the form of through holes) or underneath the constraining elements 4 (if they are defined by deformation or tilting of the section bars 3 or by the addition of inserts 5). In this way, the filling material 6 "sticks" to the constraining elements 4 and its movement along the vertical axis "Z" is prevented by the constraining elements 4.

[0067] Advantageously, the method provides for creating undercuts through which the filler material 6 adheres, thereby preventing it from sliding along the vertical axis "Z", and thus the article 1 produced by the method ensures that material deposited on the interface structure is not removed therefrom.

[0068] In particular, as can be seen, for example, in FIG. 2B, the filler material 6 is held by respective restraining elements 4 which prevent it from peeling off from the base element 2 .

[0069] The method may further include a milling step to produce the standard article 1, or through this method a support base for the filler material 6 may be created, which may be defined by a grid welded to a smooth base, a series of welded metal strips angled or riveted to a "base plate" (or more generally base element 2), a series of metal strips fitted into grooves cut into the base support and then optionally welded, or a preformed foam welded or fabricated onto the base element or plate 2.

[0070] In an alternative embodiment, the method includes the possibility of using a metal powder sintered to a base metal surface (or the possibility of using a weld bead made without an assist gas), which creates a superstructure with a "cellular" or more generally "open cell" topology on the base surface 2a, inside which the polymer can slip.

[0071] Advantageously, the substrates produced using this method have a unique morphology and at the same time exhibit a unique structural function which, in relation to this methodology, gives the article 1 as a whole particularly advantageous properties in terms of the ability of the polymeric material to interpenetrate (and therefore to establish significant overall restraint). According to the invention, this interpenetration ability is far superior to that achieved with the above-mentioned known methodologies, in which the polymeric material, again for various reasons mentioned above, is unable to reach all of the pre-determined internal spaces, i.e., reaches and fills them, but in an incomplete manner, i.e., does not reach "deep" into the honeycomb structure.

[0072] Advantageously, the methods disclosed and described herein make it possible to produce a wide range of products in a particularly efficient manner. The present invention therefore also consists in an article 1 made by the above-described method and / or the following claims.

Claims

1. A method for manufacturing an article (1), comprising: - providing a base element (2); - providing a plurality of section bars (3); - fixing said section bar (3) to a surface (2a) of said base element (2), preferably to its upper surface; In a method comprising: - defining, by one or more of said section bars (3), a number of restraining elements (4) which are effective at least along a vertical axis (Z) transverse to, and preferably perpendicular to, said base element (2); - applying a filler material (6) onto said base element (2) at least in one engagement jointly defined between said surface (2a) and at least one of said restraining elements (4); The method further comprising:

2. 2. The method according to claim 1, wherein the step of defining the plurality of restraining elements (4) is performed by locally deforming one or more section bars (3).

3. 3. The method according to claim 2, wherein the local deformation of one or more section bars (3) is performed by drawing, or indenting, or bending, or calendering, or forming.

4. The method according to any one of claims 1 to 3, wherein the step of defining a plurality of restraining elements (4) is performed by defining one or more holes in at least one section bar (3).

5. 5. The method according to any one of claims 1 to 4, wherein the step of defining the plurality of restraining elements (4) is performed by arranging one or more section bars (3) at a predetermined inclination angle (A) relative to the surface (2a).

6. 6. The method according to claim 5, wherein the inclination angle (A) is comprised between 45° and 90°.

7. 7. The method according to any one of claims 1 to 6, wherein the step of defining the plurality of restraining elements (4) is carried out by crossing the section bars (3) with a plurality of inserts (5) that are or can be fixed to the top or middle of each section bar (3).

8. 8. The method according to any one of claims 1 to 7, wherein the step of providing the section bars (3) is performed such that the section bars (3) define grid elements to which the section bars (3) connect.

9. The method according to any one of claims 1 to 8, wherein the step of providing the section bars (3) is performed such that the section bars (3) define a honeycomb structure.

10. 10. The method according to claim 8 or 9, wherein the step of providing the section bar (3) defines a plurality of containment cells (3a) and the step of defining a plurality of restraining elements (4) is performed such that each containment cell (3a) includes at least one restraining element (4).

11. The method according to any one of claims 1 to 10, wherein the step of fixing the section bar (3) to the base element (2) is performed by welding or sintering the section bar (3) to the base element (2).

12. The method according to any one of claims 1 to 11, comprising a step of cutting the base element (2) to create a plurality of grooves in the base element (2), and the fixing step is performed by fitting the section bars (3) into the respective grooves.

13. The method according to any one of claims 1 to 12, further comprising a milling step to produce the article (1).

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