METHOD FOR AUTOMATICALLY PRODUCING A CONGLOMERATE STRUCTURE AND APPARATUS THEREFOR

• US 20100207288A1
• Filed: 09/17/2008
• Published: 08/19/2010
• Est. Priority Date: 09/17/2007
• Status: Active Grant

• Current Assignee: Enrico Dini
• Original Assignee: Enrico Dini
• Inventors: Dini, Enrico
• Granted Patent: US 8,337,736 B2
• Time in Patent Office: Days
• US Class Current: 264/33
• CPC Class Codes: B28B 1/001 Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00
• CPC Class Codes: B28B 7/465 Applying setting liquid to dry mixtures
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B29C 67/243 for making articles of definite length
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: E04B 1/161 with vertical and horizontal slabs, both being partially cast in situ
• CPC Class Codes: E04B 1/3505 characterised by the in situ moulding of large parts of a structure E04B1/3511, E04B1/3516, E04B1/3522, E04B1/3533, E04B1/3544, E04B1/355 take precedence

Abstract

A method and an apparatus for automatically making conglomerated structures (6). The method comprises a) modelling a building structure and a containing shell about the structure by a computer using a CAD software thus obtaining a file; b) extracting sections of modelled structure and of modelled containing shell, by means of horizontal planes spaced apart of a predetermined pitch, such that a plurality of section planes is generated, said planes being sorted from below towards above with respect to the model of the structure and of the model of the shell; c) depositing by a moving unit (3) on a ground a bottom-to-top plurality of layers of granular material (22) alternate to a binding material liquid sprayed on the layers at filled areas corresponding to filled portions of the of the structure and of the containing shell, according to a predetermined path; d) vertically raising the moving unit (3) according to a pitch between a deposited layer and the following layer; e) repeating the step of depositing granulating material and repeating the step of spraying the binding material on a granulated material at filled areas of the structure and of the shell as many times as the planar cross sections into which said structure and the containing shell have been divided, each of said times for a different and consecutive section plane until the last layer (17) is complete; f) demolishing the containing shell (5) and removing unbound granular material (7) accumulated in the shell (5), thus releasing a conglomerate structure (6) that reproduces accurately said modelled structure. The apparatus comprises a horizontal frame (1), a bridge (2) sliding on guide on the horizontal frame (1), a moving unit (3) sliding along the bridge (2) or integral to the bridge (29) and have a spraying head (20). The horizontal frame (1) is moved along uprights (4) by a step actuator. The apparatus comprises a plurality of “skirts” (10) that surround the containing shell (5) and are integral to the horizontal frame (1). Such skirts scrape the outer surface of the containing shell (5) collecting the granular material (21) deposited out of the shell (5). Such skirts (10) can comprise an brush-like edge (20) suitable for externally sweeping the containing shell (5).

Claims

1. A method for automatically building conglomerate structures, characterised in that it comprises the steps of:

modelling in a computer-aided way a building or other masonry construction structure by a CAD software, in particular by a surface- or a solid-modelling CAD software, thus obtaining a model of said structure, said model stored in a file of a computer memory;

modelling by said CAD software a containing shell about said building structure, thus obtaining a model of said containing shell, said model stored in a file of said computer memory;

extracting from said model of said structure and from said model of said containing shell a plurality of planar cross-sections on a plurality of horizontal planar cross-sections, said section planes evenly spaced at a prefixed vertical pitch, said planar cross-sections comprising filled areas and blank areas respectively corresponding to filled portions and blank portions of said structure and of said containing shell in said section planes, said planar cross-sections being sorted from below towards above;

prearranging a fixed frame on which a moving unit slides, said moving unit suitable for alternately depositing a granular material layer and spraying a binding material in a liquid form on said granular material layer;

depositing a first uniform horizontal layer of said granular material by said moving unit, said first layer having a thickness related to said prefixed vertical pitch;

spraying a predetermined amount of said binding material by said moving unit on said first layer of said granular material, said spraying being limited to said filled areas of a first planar cross-section;

vertically raising said moving unit with respect to said fixed frame according to said vertical pitch;

depositing a second uniform horizontal layer of granular material on said first layer and spraying a predetermined amount of binding material on said second layer, said spraying being limited to said filled areas of a second cross-section;

repeating said step of depositing said granular material and repeating said step of spraying a predetermined amount of binding material at said filled areas of each respective cross-section until a last layer is complete, thus obtaining at least one monolithic body corresponding to said building or other masonry construction structure, and at least one monolithic body corresponding to said containing shell, wherein the inner blank spaces are filled with loose granular material;

demolishing said containing shell and removing said loose granular material obtaining said building or other masonry construction structure.

2. A method, according to claim 1, wherein, in order to perform said step of depositing said granular material and said step of spraying said binding material according to said model of said structure and of said shell, a calculation step is provided for calculating a program matrix used to actuate said moving unit, said moving unit having a plurality of electrically actuated valves for opening and closing respective distributing nozzles, said opening and closing performed by a control unit which operates according to said program matrix.

3. A method, according to claim 1, wherein a step is provided of pressing each uniform layer of said granular material, in particular by means of a pressing element associated with said moving unit, said pressing element suitable for applying a predetermined pressure on said uniform layer of said granular material, said pressing being carried out before said binding material is sprayed upon the respective layer.

4. A method, according to claim 1, wherein said containing shell has vertical or sloping portions, whose cross sections form a closed shape selected from the group comprised of:

a regular geometric shape;

an irregular geometric shape;

a shape suitable for externally contouring the plan of said structure, said shape located at a predetermined minimum distance from said plan.

5. A method, according to claim 1, wherein said binding material is a two-component inorganic binding material comprising:

a liquid component which is sprayed by said moving unit;

a catalyst.

6. A method, according to claim 5, wherein said liquid component, contains inorganic substances, in particular chlorides.

7. A method, according to claim 5, wherein the contact between said liquid component and said catalyst occurs on the deposited layer of said granular material.

8. A method, according to claim 5, wherein said catalyst is a powder solid, and is dispersed among the granular material to form a mixture.

9. A method, according to claim 8, wherein said catalyst has a granulometry finer than the granulometry of said granular material.

10. A method, according to claim 5, wherein said component has a viscosity value set between 1×

10<sup>−

3</sup> Ns/m and 2×

10<sup>−

3</sup> Ns/m and a surface tension value set between 0.07 N/m and 2 N/m.

11. A method, according to claim 5, wherein said catalyst contains metal oxides.

12. A method, according to claim 1, wherein said granular material has a granulometry set between 0.01 mm and 65 mm.

13. A method, according to claim 8, wherein a step is provided of adding high tensile strength reinforcing fibres to said mixture of said granular material and of said catalyst, said reinforcing fibres selected from the group comprised of:

glass fibres;

carbon fibres;

nylon fibres.

14. A method, according to claim 1, wherein a step is provided of laying a network of a stiff, chloride-corrosion-resistant material, in particular for reinforcing a portion of said monolithic body corresponding to a wide-span floor of said building.

15. A method, according to claim 1, wherein said step of spraying is carried out according to a predetermined path of said moving unit in a horizontal plane, said path comprising a longitudinal spraying stroke, in particular said longitudinal spraying stroke is followed by at least one further, reversely directed longitudinal spraying stroke, said reversely directed stroke preceded by a transverse shifting movement of said moving unit.

16. A method, according to claim 1, wherein said step of spraying is carried out along a whole width of the layer of the granular material, or a substantial part of said width, through a plurality of nozzles arranged adjacent to each other along said moving unit.

17. A method, according to claim 1, wherein said predetermined amount of binding material is such that the binding material penetrates the whole thickness of a layer in at least one portion of said filled areas, said portion selected from the group comprised of:

the contour of said filled areas, creating a skin with a determined thickness to fulfil the requirements for structural stability;

a cross pattern inside said filled areas, forming recesses where unbound granular material is present,

a combination thereof.

18. An apparatus for automatically building conglomerate structures is characterised in that it comprises:

a means for loading a file containing a CAD model, said CAD model comprising a model of said structure, and a model of a containing shell to be erected about said structure;

a means for extracting from said CAD a plurality of planar cross-sections on a plurality of horizontal section planes, said section planes evenly spaced at a prefixed vertical pitch, said planar cross-sections comprising filled areas and blank areas respectively corresponding to filled portions and blank portions of said structure and of said containing shell, said section planes being sorted from below towards above;

a fixed frame on which a moving unit slides, in particular a bridge crane unit having a bridge sliding on horizontal guides;

a lifting means suitable for bearing said horizontal guides and for vertically shifting said horizontal guides according to said predetermined vertical pitch;

a depositing means for depositing layers of granular material, said granular material layers having a thickness related to said prefixed vertical pitch, said depositing means associated with said moving unit;

a spraying means for spraying said binding material on each said respective layer of granular material at said filled areas of each section plane, said filled areas comprising portions of said building structure and portions of said shell, said spraying means associated with said moving unit.

19. An apparatus, according to claim 18, wherein said moving unit comprises a plurality of nozzles for distributing said binding material, said nozzles matrix-like arranged according to a prefixed number of rows and to a prefixed number of columns, in particular said nozzles actuated independently from one another.

20. An apparatus, according to claim 19, wherein said rows of said matrix are spaced apart at a distance from each other in order to form an overall distance substantially equal to the print width covered by each nozzle.

21. An apparatus, according to claim 18, wherein said lifting means comprises a step motor, each step equal to said predetermined vertical pitch.

22. An apparatus, according to claim 18, wherein said lifting means comprises an hydraulic linear actuator, said actuator operating step by step according to said predetermined vertical pitch, said actuator associated with a plurality of pins which may be inserted/extracted in/from respective transversal holes of said upright.

23. An apparatus, according to claim 18, comprising a plurality of containing elements, or “

skirts”

, said skirts externally surrounding said containing shell, said skirts integral to said horizontal frame, wherein said skirts scrape the outer surface of said containing shell while said containing shell is being built, and collect the granular material falling outside said containing shell.

24. An apparatus, according to claim 23, wherein said skirts comprise a substantially horizontal portion or a portion sloping towards said granular material containing shell and a substantially vertical portion which stabilises said containing shell during the hardening of said containing shell.

25. A method for automatically building conglomerate structures, characterised in that it comprises the steps of:

modelling in a computer-aided way a building structure by a CAD software, in particular by a surface- or a solid-modelling CAD software, thus obtaining a model of said structure, said model stored in a file of a computer memory;

extracting from said model of said structure a plurality of planar cross-sections on a plurality of horizontal section planes, said section planes evenly spaced at a prefixed vertical pitch, said planar cross-sections comprising filled areas and blank areas respectively corresponding to filled portions and blank portions of said structure in said section planes, said section planes being sorted from below towards above;

prearranging a fixed frame on which a moving unit slides, said removable unit suitable for alternately depositing a layer of a granular material homogeneously mixed with a catalyst in the form of a powder, said removable unit suitable for spraying a binding material in a liquid form on said granular material layer according to said filled areas of said structure;

depositing by said moving unit a uniform horizontal first layer of said granular material homogeneously mixed with said catalyst in the form of a powder, said first layer having a thickness related to said prefixed vertical pitch;

spraying by said moving unit a first layer of a liquid component suitable for chemically reacting with said catalyst in the form of a powder, upon said first layer of said granular material, said spraying being limited to said filled areas of a first section plane, according to a prefixed path;

vertically raising said moving unit with respect to said fixed frame according to said vertical pitch to form a further layer of said granular material and of said binding material;

repeating said step of depositing said granular material and said catalyst and repeating on said deposited granular material and said catalyst said step of spraying said liquid component at said filled areas as many times as the planar cross sections into which said structure has been divided, each of said times for a different and consecutive section plane until a last layer is complete;

removing unbound granular material releasing the obtained conglomerate structure, which reproduces accurately said modelled structure.

26. A method for automatically building conglomerate structures comprising the steps of:

modelling in a computer-aided way a building structure by a CAD software, in particular by a surface- or a solid-modelling CAD software, thus obtaining a model of said structure, said model stored in a file of a computer memory;

extracting from said model of said structure a plurality of planar cross-sections on a plurality of horizontal section planes, said section planes evenly spaced at a prefixed vertical pitch, said planar cross-sections comprising filled areas and blank areas respectively corresponding to filled portions and blank portions of said structure in said section planes, said section planes being sorted from below towards above;

prearranging a fixed frame on which a moving unit slides;

depositing by said moving unit a uniform horizontal first layer of said granular material, said first layer having a thickness related to said prefixed vertical pitch;

spraying by said moving unit a first layer of a liquid component upon said first layer of said granular material, said spraying being limited to said filled areas of a first section plane, according to a prefixed path;

vertically raising said moving unit with respect to said fixed frame according to said vertical pitch to form a further layer of said granular material and of said binding material;

repeating said step of depositing said granular material and said catalyst and repeating on said deposited granular material and said catalyst said step of spraying said liquid component at said filled areas as many times as the planar cross sections into which said structure has been divided, each of said times for a different and consecutive section plane until a last layer is complete;

removing unbound granular material releasing the obtained conglomerate structure, which reproduces accurately said modelled structure,

characterized in that said binding material is a two-component inorganic binding material comprising;

a liquid component containing inorganic substances, in particular chlorides;

a catalyst containing metal oxides.