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EP-4741129-A1 - METHOD AND MACHINING CENTER FOR SHEETS

EP4741129A1EP 4741129 A1EP4741129 A1EP 4741129A1EP-4741129-A1

Abstract

A method and a numerically controlled machining center for processing sheets are disclosed, in which a large sheet is positioned on locking devices arranged on a work surface of the machining center and is then cut with a cutting tool to obtain two or more sheet portions, and in which a numerically controlled manipulator laterally moves at least one sheet portion that adheres by suction to at least one underlying locking device that slides on the work surface supported by an air cushion until it stops the sheet portion, interrupting the air cushion and activating a suction that blocks the locking device to the work surface in a desired position in which the sheet portion is further processed by removing material.

Inventors

  • GHISALBERTI, Oliviero

Assignees

  • C.M.S. S.p.A.

Dates

Publication Date
20260513
Application Date
20251110

Claims (16)

  1. Machining method in a numerically controlled machining centre (1), said method comprising the following steps: - positioning two or more locking devices (5) on a work surface (3) of said numerically controlled machining centre (1); - positioning a sheet (4) on said locking devices (5); - cutting said sheet (4) with a cutting tool (8) controlled by said numerically controlled machining centre (1) so as to divide said sheet (4) into two or more sheet portions (9) separated from each other in which each sheet portion (9) is arranged on at least one of said locking devices (5); - moving one sheet portion (9), among said two or more sheet portions (9) obtained from said cutting step, on said work surface (3) by means of moving means, wherein during said moving step a gripping suction is generated to make said sheet portion (9) adhere to the respective locking device (5), whereby the respective locking device (5) is in turn moved together with said sheet portion (9), and furthermore an air cushion is generated to facilitate sliding of the respective locking device (5) on said work surface (3); - stopping said moving so as to position said sheet portion (9) in a determined position; - blocking said sheet portion (9) in said determined position by interrupting said air cushion and making said respective locking device (5) adhere by suction to said work surface (3); - machining said sheet portion (9) in said determined position by means of a tool (11) controlled by said machining centre (1).
  2. Method according to claim 1, wherein, during said cutting step, said cutting tool (8) is carried by a work head (2) of said machining centre; during said cutting step it being provided, in particular, that said cutting tool (8) is connected to said work head (2) by means of an angular transmission.
  3. Method according to claim 2, wherein, during said moving step, said moving means is carried by said work head (2) and/or wherein, during said machining step, said tool (11) is carried by said work head (2).
  4. Method according to any one of the preceding claims, wherein during said step of positioning a sheet (4), an air cushion is generated to facilitate sliding of the sheet (4) on said locking devices (5).
  5. Method according to any one of the preceding claims, wherein, during said moving step, a gripping suction is generated to make said moving means adhere to said sheet portion (9); and/or. wherein said positioning step comprises positioning three, or four, or more than four, locking devices (5) on said work surface (3) and said cutting step comprises cutting said sheet (4) so as to divide it into three, or four, or more than four, sheet portions (9) which are separated from each other and in which each sheet portion (9) is arranged on at least one respective locking device (5); and/or wherein each sheet portion (9) is arranged on a respective locking assembly comprising one or more of said locking devices (5), each locking assembly being connected to a respective manifold (17) in turn connected to blowing means (7) generating said air cushion and to suction means (6) generating said gripping suction.
  6. Method according to any one of the preceding claims, wherein each of said locking devices (5) comprises a locking member with an upper end coupled with said sheet (4) or sheet portion (9) and a lower end coupled with said work surface (3); said locking member being connected to suction means (6) configured to generate said gripping suction; said locking member being connected to blowing means (7) configured to generate said air cushion.
  7. Method according to claim 6, wherein, during said step of positioning a sheet (4), said blowing means (7) is connected to said upper end and said suction means (6) is connected to said lower end.
  8. Method according to claim 6 or 7, wherein, during said moving step, said suction means (6) is connected to said upper end and said blowing means (7) is connected to said lower end; and/or wherein, during said cutting, blocking and machining steps, said suction means (6) is connected to said upper end and said lower end; and/or wherein said blocking step comprises the use of switching means (12) switching the connection of said lower end from a connection with said blowing means (7) to a connection with said suction means (6).
  9. Method according to any one of claims 6 to 8, wherein said lower and upper ends are operatively connected to said blowing means (7) and to said suction means (6) independently of each other.
  10. Method according to any one of the preceding claims, wherein, during said moving step, said moving means is controlled by said numerically controlled machining centre (1); said moving means comprising, in particular, a manipulator (10).
  11. Numerically controlled machining centre, comprising: - a movable work head (2) with three or more controlled axes; - a work surface (3) configured for positioning a sheet (4) to be machined by said work head (2); - two or more locking devices (5) positionable on said work surface (3) and configured to receive the sheet (4), each of which comprises a locking member with an upper end that is couplable with the sheet (4) and a lower end that is couplable with the work surface (3); - suction means (6) connected to said locking member to generate suction in said upper and lower ends; - blowing means (7) connected to said locking member to generate an air cushion at least in said lower end; - at least one cutting tool (8) associable with said work head (2) to divide the sheet (4) received by said two or more locking devices (5) into two or more sheet portions (9) separated from each other in such a way that each sheet portion (9) is arranged on at least one of said locking devices (5); - moving means configured to move at least one sheet portion (9) into which the sheet (4) has been divided by said cutting tool (8); - a tool (11) associable with said work head (2) to machine the sheet portion (9) with a typical machining operation of a machining centre, such as for example milling and/or drilling and/or grinding and/or engraving.
  12. Machining centre according to claim 11, wherein said locking member internally comprises two operative cavities (13; 14) separated from each other, each of said two operative cavities (13; 14) being connected to a respective one of said upper and lower ends.
  13. Machining centre according to claim 12, wherein said locking member comprises an air connection (15; 16) for each of said two operating cavities (13; 14), each air connection (15; 16) being connected to said suction means (6) and to said blowing means (7) by means of switching means (12) and by means of a single flexible hose usable for both blowing and suction.
  14. Machining centre according to any one of claims 11 to 13, wherein said machining centre comprises switching means (12) configured to selectively connect said lower end with said blowing means (7) and with said suction means (6); and/or wherein said lower end and said upper end are operatively connected to said suction means (6) independently of each other; and/or wherein said machining centre comprises two or more locking assemblies each of which is operably associable with a respective sheet portion (9), each of said two or more locking assemblies comprising one or more of said locking devices (5), said machining centre (1) comprising two or more manifolds (17) connected to said suction means (6) and to said blowing means (7), each of said two or more manifolds (17) being connected to a respective locking assembly such that said two or more locking assemblies are independently connected from one another to said suction means (6) and to said blowing means (7).
  15. Machining centre according to any one of claims 11 to 14, comprising electronic and programmable control means configured to control said moving means; wherein said moving means comprises, in particular, a manipulator (10); said manipulator (10) comprising, in particular, vacuum gripping means by means of the Venturi effect.
  16. Machining centre according to claim 15, wherein said manipulator (10) is an aggregate that can be removed from a tool magazine of said machining centre (1) and/or wherein said manipulator (10) is mounted on said work head (2) with the possibility of carrying out a movement with respect to said work head (2), for example by means of a slide or cursor, between a rest position and a working position, for example by means of a pneumatic movement device.

Description

Background of the invention The invention concerns a machining method and a machining center for processing sheets, particularly for processing sheets of marble or other stone materials, but also for glass sheets (for example, for cutting and grinding laminated glass) or sheets of metal, composite materials, wood, etc. Specifically, but not exclusively, the invention can be applied in the kitchen and/or furniture manufacturing sector in general. Prior art It is known that, in order to obtain all the pieces needed for the production of kitchen furniture or furnishings in general, two separate machines are used: a bridge saw to divide a large sheet of stone material using a cutting disc into various portions or sections of the sheet, which are then machined in a numerically controlled machining center with three or more machining axes to perform the typical machining operations of a machining center, such as milling, drilling, grinding, engraving, etc. The prior art, however, has some limitations and drawbacks. First, especially for small manufacturers with a relatively small work volume, purchasing two machines (a bridge saw and a machining center) may not be cost-effective, due to the impossibility of reaching or even approaching saturation of production capacity, leaving one or both machines unused even for long periods of the week. Second, installing two separate machines, in addition to being expensive, requires relatively large amounts of space and could also lead to greater complications in the production process. Another area that could be improved is reducing operator intervention in the production process by increasing its automation. Summary of the invention An object of the invention is to provide a method and a machining center capable of overcoming one or more of the aforementioned limitations and drawbacks of the prior art. An object is to perform operations typical of a bridge saw and a machining center within the same machine. An advantage is to allow saturation of production capacity even in the case of relatively small work volumes. An advantage is to provide a method and a machining center for performing various operations with high precision and efficiency. Other advantages are to enable a production process with a considerable degree of automation and considerable versatility of use, as well as to make it possible to install the machinery necessary to perform a variety of operations while occupying little space and with a relatively small investment. These objects and advantages, and others, are achieved by a method and a machining center according to one or more of the claims listed below. In one example, a machining method comprises: positioning a sheet on a plurality of locking devices arranged on a work surface of a numerically controlled machining center; cutting the sheet using a numerically controlled cutting tool to obtain two or more sheet portions, each of which is arranged on one or more locking devices; moving laterally at least one of the sheet portions thus obtained using a numerically controlled manipulator by making the sheet portion adhere by suction to each locking device underneath the sheet portion and by sliding each underlying locking device on the work surface thanks to the generation of an air cushion until the sheet portion is stopped, interrupting the air cushion and activating a suction that blocks each underlying locking device on the work surface in a desired position in which the sheet portion will be further machined by removing material. The proposed solution allows the use of a 3 or 4 or 5-axis controlled machining centre as if it were, in practice, a real bridge milling machine (equipped, in particular, with a manipulator), with the possibility of carrying out (in particular, with an automatic work cycle, with practically no intervention by personnel) both the cutting or sectioning of a sheet using a cutting tool (for example a disc), and the processes normally carried out by a numerically controlled machine (drilling, milling, boring, grinding, engraving, threading, etc.). In particular, it is possible to use a cutting disc with a relatively small diameter, for example, a diameter of approximately 200 mm, which has sufficient cutting capacity to effectively process sheets with thicknesses from 10 mm to 60 mm. The cutting tool may be mounted on the work head of the numerically controlled machining center using an angular transmission. Depending on the proposed solution, the machining center may include, in particular, two, or three, or four, or more than four manifolds for supplying vacuum to the various locking devices (suction cups) that serve to secure the sheet to be machined on the work surface by suction. Each manifold may be configured, in particular, to supply pressurized air to the various locking devices to generate an air cushion (at the lower end of each locking device, i.e., between each locking device and the work surface) to facilitate, wh