WO2024079683A1 - Forming punching apparatus - Google Patents

Abstract

A punching apparatus (1) for forming workings on a workpiece (100) comprises a punch holder unit (2) which includes an upper support body (3) rotatable about a working axis (X), a punch holder body (4) that houses a plurality of upper forming tools (31) and an upper beating element (5) movable parallel to the working axis (X) to selectively interact with an established upper forming tool (31); a die holder unit (12) that includes a lower support body (13) rotatable about the working axis (X), a die holder body (14) that houses a plurality of lower forming tools (32) and a lower beating element (15) movable linearly along and rotatably about the working axis (X) to selectively interact with an established lower forming tool (32); the lower beating element (15) is movable linearly between an non-operative position (A), in which it is locked in rotation and does not rotate together with said lower support body (13), a first operative position (B), in which it is connected to the lower support body (13) so as to rotate together with the latter, and a second operative position (C), in which it pushes the lower forming tool (32) partially outside the die holder body (14).

Description

Forming punching apparatus

The invention concerns machine tools for working workpieces and/or sheets metal and in particular concerns a forming punching apparatus that can be associated with a punching machine for performing forming and/or deformation workings on workpieces.

Punching machines are known that are provided with a punching apparatus, called punching head, which supports and moves linearly along a working axis a tool that acts on the workpiece, typically a sheet metal, cooperating with an underlying die or counter-tool,. The die is generally fixed to a working surface of the punching machine that supports the workpiece.

A first type of punching tools comprises punches or punch inserts capable of cutting, shearing, punching the workpiece to make holes, slots, variously shaped through openings or separation contours, division cuts or capable of making deep-drawings facing the working surface (i.e., downwards). The respective dies comprise cavities having a shape almost complementary to that of the respective punches so as to receive the punches while the working is being performed.

A second type of tool comprises forming or deformation tools capable of plastically deforming the workpiece to make deep-drawings of different shapes and sizes, bridges, slits, etc., which project from the opposite side of the working surface (i.e., upwards).

The forming process can be static, keeping the workpiece stationary during working, or dynamic, moving the workpiece, typically to make elongated deformations such as steps, ribs, slits, etc. Since the deformation of the workpiece is opposite to the working surface (upforming) the dies comprise lower forming tools having a shape complementary to the shape of the upper forming tools and also movable linearly with the upper forming tools and in opposite direction. The forming tools typically comprise wheels, rollers, discs, having a suitably shaped external profile and rotatable about an axis orthogonal to the working axis. In the single-tool punching heads, the tool is mounted on a support element, called spindle, which is driven linearly along and rotary about the working axis by respective actuators. The linear movement along the working axis in the two opposite directions allows performing working and return strokes of the tool in the punching process. The rotation movement about the working axis allows the punching tool to rotate and change its angular orientation (indexing) to perform different cuts or punchings on the workpiece.

The multi-tool punching heads comprise a plurality of punching tools and a beating element, called ram element, which is moved linearly along the working axis and acts on the selected punching tool, by imparting to the latter the kinetic energy and the linear movement necessary to perform the working on the workpiece.

The punching tools or punches are housed in a tool holder device that is fixed to the punching head and is arranged between the ram element and the workpiece. The tool holder device generally comprises a rotatable drum in which the tools are slidably housed and arranged circumferentially about the drum rotation axis.

Each multi-tool punching head also comprises a multiple die, that is, provided with a plurality of dies in a number equal to the number of the respective punches and rotatable about the working axis to allow the angular orientation of the punches.

The known multi-tool punching heads cannot however mount the forming tools, as the dies are not able to receive a plurality of lower forming tools, and in particular they are not able to move such tools along and about the working axis in order to select the lower forming tool, orient it angularly, and then lift it towards the upper forming tool against the workpiece. US 2019/366411 discloses a set of punches and dies and a selecting apparatus which are configured to perform forming workings on sheet materials. The selecting apparatus can be associated with a punching machine to select a punch and a die, which must be engaged by a beating element of the punching machine, and to force or allow the movement of the unselected dies away from the sheet material so as not to impact or damage the latter while it is being worked.

An object of the present invention is to improve the known punching apparatuses, in particular the forming punching apparatuses.

Another object is to carry out a punching apparatus provided with a plurality of upper and lower forming tools that can be selected, angularly oriented and activated quickly and efficiently.

A further object is to carry out a punching apparatus that allows a plurality of different forming or deformation workings to be optimally performed, with the workpiece stationary or moved.

Another object is to provide a forming punching apparatus having a simple and compact structure and small dimensions.

These and other objects are achieved by a punching apparatus according to one or more of the claims reported below. The invention can be better understood and implemented with reference to the attached drawings, which illustrate an exemplary and non-limiting embodiment, in which: figure l is a front view of a punch holder unit of the punching apparatus of the invention; figure 2 is a longitudinal section along the line II-II of figure 1 wherein a selected upper forming tool is in a retracted non-operative position; figure 3 is a perspective view of the punch holder unit of figure 1; figure 4 is a bottom plan view of the punch holder unit of figure 1 ; figure 5 is an exploded view of the punch holder unit of figure 1; figure 6 is a front view of a die holder unit of the punching apparatus of the invention; figure 7 is a longitudinal section along the line VII- VII of the die holder unit of figure 6 and of driving means of the punching apparatus; figure 8 is a perspective view of the die holder unit of figure 6; figure 9 is a top plan view of the die holder unit of figure 6; figure 10 is an exploded view of the die holder unit of figure 6; figure 11 is a longitudinal sectional view of the punching apparatus of the invention associated with a workpiece; figures 12 to 14 are longitudinal sectional views illustrating a lower beating element of the die holder unit of the punching apparatus of the invention driven by the driving means in respective different operative configurations.

With reference to figures 1 to 14, a punching apparatus 1 according to the invention is shown that is associable with a punching machine, of known type and not illustrated, and is arranged to perform forming and/or deformation workings on workpieces 100, in particular sheets metal.

The punching apparatus 1, illustrated in section in figure 11, comprises a punch holder unit 2 provided with a plurality of upper forming tools or forming punches 31, for example three, and a die holder unit 12 provided with a plurality of lower forming tools or forming dies 32, for example in number equal to that of the upper forming tools 31.

The punch holder unit 2 comprising an upper support body 3 rotatable about a working axis X, a punch holder body 4 rotatably connected to the upper support body 3 and arranged to slidably house the plurality of upper forming tools 31 and an upper beating element 5. The upper beating element 5 is slidably supported by the upper support body 3 and is movable parallel to the working axis X to selectively interact with an established upper forming tool 31 so as to partially push it outside the punch holder body 4 so as to interact with the underlying workpiece 100, as better explained in the following description.

The die holder unit 12 comprising a lower support body 13 rotatable about the working axis X, a die holder body 14 fixed to the lower support body 13 and arranged to slidably house the plurality of lower forming tools 32, and a lower beating element 15.

The lower beating element 15 is housed in the lower support body 13 and is movable linearly along, and rotatably about, the working axis X to selectively interact with an established lower forming tool. The lower beating element 15 is movable linearly between an nonoperative position A, in which it is locked in rotation by first stop means 21 and does not rotate together with the lower support body 13, an operative position B, in which it is connected by second stop means 22 to the lower support body 13 so as to rotate together with the latter about the working axis X, and a second operative position C in which the lower beating element 15 pushes the established lower forming tool 32 partially outside the die holder body 14 so as to interact with the overlying workpiece 100.

With particular reference to figures 6 to 11, the die holder body 14 comprises a plurality of lower seats 16 each of which is adapted to receive a lower tool holder element 34 to which a respective lower forming tool 32 is associated. Each lower tool holder element 34 comprises, in particular, a first end 34a configured to receive and support the respective lower forming tool 32 and a second end 34b suitable to interact with the lower beating element 15.

In the illustrated embodiment, the lower forming tools 32 comprise shaped wheels or rollers that are mounted on respective lower tool holder elements 34 and are idly rotatable about respective first rotation axes Yl, nearly orthogonal to the working axis X.

The die holder unit 12 further comprises a plurality of lower thrust elements 17 that are slidably connected to the die holder body 14 and arranged to support respective lower tool holder elements 34 of the lower forming tools 32. Each lower thrust element 17 can be abutted and moved along the working axis X by the lower beating element 15 so as to move the respective lower tool holder element 34 and therefore the corresponding lower forming tool 32, as better explained in the following description.

Each lower thrust element 17 has a substantially prismatic shape and comprises two opposite and parallel abutment walls, in particular almost orthogonal to the working axis X, and intended respectively to abut the second end 34b of the lower tool holder element 34 (to support the lower tool holder element and the lower deformation tool 32 associated therewith) and to be abutted by the lower beating element 15.

The lower beating element 15 is slidable within a cavity 23 of the lower support body 13 and has a main body 15c of almost cylindrical shape.

The lower beating element 15 is slidably connected to the die holder body 14 by a first guide pin 20 having a first upper end 20a fixed to the die holder body 14 and a second lower end 20b that is slidably coupled to a seat 27 of the lower beating element 15. The first guide pin 20 is substantially coaxial to the working axis X.

First elastic means 28 are interposed between the lower beating element 15 and the die holder body 14 and are configured to elastically keep said lower beating element 15 spaced apart from said die holder body 14 in the non-operative position A.

The first elastic means 28 comprise, for example, a respective cylindrical helical spring mounted on the first guide pin 20.

The lower beating element 15 also comprises a first abutment portion 15a that extends from the main body 15c and is configured to abut an established thrust element 17 so as to move the corresponding lower forming tool 32.

The die holder unit 12 comprises second elastic means 18 interposed between each lower thrust element 17 and the die holder body 14 and configured to elastically keep said lower thrust elements 17 spaced apart from the die holder body 14 in a respective non-operative position E when not abutted and pushed by the lower beating element 15. Each lower thrust element 17 is slidably connected to the die holder body 14 by one or more, for example two, second guide pins 19 on which the first elastic means 18 are mounted that comprise respective cylindrical helical springs.

The first stop means 21 comprise a first tab configured to engage a longitudinal groove 24, in particular parallel to the working axis X, made on an external wall of the lower beating element 14. The first tab 21 is for example connected to support means 80 of the punching machine on which the die holder unit 12 is mounted.

The second stop means 22 comprise a second tab fixed to the second support body 13 and configured to engage the longitudinal groove 24 of the lower beating element 15.

The punching apparatus 1 also comprises driving means 25, 26 acting on the lower beating element 15 to move it linearly in the operative positions B, C along a thrust direction F, in particular towards the overlying punch holder unit 2. In particular, driving means 25, 26 abut and act on a second abutment portion 15b of the lower beating element 15 opposite to the first abutment portion 15a.

In the illustrated embodiment, the driving means 25, 26 comprise a first linear actuator 25 adapted to move the lower beating element 15 between the non-operative position A and the first operative position B and a second linear actuator 26 adapted to move the lower beating element 15 between said first operative position B and the second operative position C.

Alternatively, the driving means may comprise a single linear actuator capable of controllably moving the lower beating element 15 between the non-operative position A and the first operative position B and between the first operative position B and the second operative position C.

In particular, the driving means 25, 26 can be integrated into the punching machine on which the punching apparatus 1 is mounted.

The die holder body 14 comprises an upper wall 14a adapted to abut and support a workpiece 100. In the upper wall 14a there are the plurality of lower seats 16 in which the lower tool holder elements 34 to which the respective lower forming tools 32 are associated are housed. With particular reference to figures 1 to 6, the punch holder body 4 of the punch holder unit 2 comprises a plurality of upper seats 6 each of which is adapted to receive a respective upper thrust element 7 and an upper tool holder element 33 to which a corresponding upper forming tool 31 is associated. Each upper thrust element 7 is interposed between the upper beating element 5 and the respective upper tool holder element 33.

In particular, each upper thrust element 7 comprises an abutment end 7a configured to interact with a respective beating portion 5a of the upper beating element 5 and a connecting end 7b that is coupled to the upper tool holder element 33.

Each upper thrust element 7 is slidably engaged in a first guide portion 6a of the respective upper seat 6 while the upper tool holder element 33 connected thereto is slidably engaged in an underlying second guide portion 6b of the upper seat 6.

The upper thrust element 7 comprises an upper part 70, which includes the abutment end 7a, having an almost cylindrical pin shape and a lower part 71, which includes the connecting end 7b having a prismatic shape. The cylindrical wall of the upper part 71 has a longitudinal flattening 70c that prevents the rotation of the upper thrust element 7 about its longitudinal axis inside the first guide portion 6a of the respective upper seat 6.

In the illustrated embodiment, the upper forming tools 31 comprise respective wheels or shaped rolls or discs, mounted on the upper tool holder elements 33 and idly rotatable about respective second rotation axes Y2 almost orthogonal to the working axis X.

The punch holder unit 2 comprises a closing disc 35 fixed to a lower portion of the punch holder body 4 and provided with through openings 35a that allow the upper forming tools 31 to exit.

The punch holder unit 2 also comprises an abutment element 8 slidably connected to the upper support body 3 and to which the upper beating element 5 is fixed. The abutment element 8 is configured to interact with a ram element, of known type, of the punching machine on which the punching apparatus 1 is mounted.

The abutment element 8 is slidably connected to the upper support body 3 by one or more, for example four, third guide pins 39 on which third elastic means 38 are mounted that comprise respective cylindrical helical springs.

The third elastic means 38 are interposed between the abutment element 8 and the upper support body 3 and are configured to elastically keep said abutment element 8 spaced apart from said upper support body 3 in a respective non-operative position G, when not pushed by the ram element of the punching machine.

The upper support body 3 also comprises a through seat 9 suitable for receiving and slidably guiding the upper beating element 5 having for example the shape of a cylindrical pin.

The operation of the forming punching apparatus 1 of the invention comprises in an initial step selecting the upper 31 and lower 32 forming tools to perform a required forming or deformation working on a workpiece 100, for example a sheet metal, which is positioned on the upper wall 14a of the die holder body element 14 of the die holder unit 12.

In order to select the upper forming tool 31, for example, the upper support body 3 is rotated about the working axis X with respect to the punch holder body 4, which is kept stationary so that the upper beating element 5 is aligned and superimposed on the selected upper forming tool 31. More precisely, after selection, the respective beating portion 5a of the upper beating element 5 faces the abutment end 7a of the upper thrust element 7 connected to the upper tool holder element 33 that houses and supports the selected upper forming tool 31.

Alternatively, the punch holder body 4 can be rotated about the working axis X with respect to the upper support body 3 which is kept stationary.

Upper support body 3 or punch holder body 4 is rotated with respect to each other about the working axis X by suitable first driving means, of known type and not described in further detail, of the punching machine on which the punching apparatus 1 of the invention is mounted.

In order to angularly orient the upper forming tool 31 with respect to the working axis (indexing) the entire punch holder unit 2 can be rotated about the working axis X.

The punch holder unit 2 is rotated about the working axis X by suitable second driving means of the punching machine, of known type and not described in further detail.

In order to select the lower forming tool 32 complementary to the selected upper forming tool 31, the lower support body 13 is rotated about the working axis X and therewith the die holder body 14, while the lower beating element 15 is kept stationary in the non-operative position A by the first tab 21, engaged in the longitudinal groove 24. In this way, it is possible to align and superimpose the desired lower forming tool 32 to the respective beating portion 15a of the lower beating element 15. More precisely, after selection, the beating portion 15a of the lower beating element 15 faces the lower thrust element 17 that supports the lower tool holder element 34 that houses and supports the selected lower forming tool 32 (figure 12).

The lower support body 13 is rotated about the working axis X by suitable third driving means of the punching machine, of known type and not described in further detail.

In order to angularly orient the lower forming tool 32 with respect to the working axis X (indexing) in accordance with the angular orientation of the selected upper forming tool 31, in a first step the lower beating element 15 is moved by the driving means 25, 26 from the non-operative position A to the first operative position B (figure 13). More precisely, the first linear actuator 25 is driven so as to raise the lower beating element 15 so that the first stop means 21 (first tab) are disengaged from the longitudinal groove 24, which is instead engaged by the second stop means 22 (second tab 22). The lower beating element 15 is therefore coupled and integral in rotation with the lower support body 13.

In a second step, the lower support body 13 is rotated about the working axis X together with the die holder body 14 and the lower beating element 15 so as to orient the selected lower forming tool 32.

It is then possible to proceed with the forming and/or deformation working of the workpiece 100 by simultaneously moving the upper forming tool 31 and the lower forming tool 32 towards each other along the working axis X. For this purpose, the upper beating element 5 is moved (for example with impulsive motion) by a ram element (not illustrated) of the punching machine so as to hit and move the thrust element 7 and therefore the punch holder element 33 connected to the latter and supporting the selected upper forming tool 31, which thus partially exit from the punch holder body 4 to interact with the workpiece 100.

Similarly, the lower beating element 15 is moved (for example also with impulsive motion) by the driving means 25, 26 from the first operative position B to the second operative position C (figure 14). More precisely, the second linear actuator 26 is driven to further raise the lower beating element 15 such that the respective beating portion 15a abuts and pushes upwards the lower thrust element 17 supporting the lower tool holder element 34 which in turn supports the selected lower forming tool 32. Thus the lower forming tool partially exits from the die holder body 14 to interact with the workpiece 100.

It should be noted that the upper and lower forming tools 31, 32 (punch and forming die) can act on the workpiece 100 that is kept stationary, for example to make deep-drawings of different shapes and sizes, such as bridges, slits, etc., which project upwards, or by moving the workpiece in the two directions orthogonal to the working axis X (i.e., horizontally) to make elongated deformations such as steps, ribs, slits, etc. which project upwards.

Thanks to the punching apparatus 1 of the invention, it is therefore possible to optimally perform a plurality of different forming and/or deformation workings on a workpiece 100 using a plurality of upper and lower forming tools 31, 32, without the need to stop the punching machine on which the punching apparatus 1 is mounted to replace the tools.

In particular, the punching apparatus 1 of the invention allows to quickly and precisely select and angularly orient two upper and lower forming tools necessary to perform a specific forming working, in particular selected from the plurality of upper forming tools 31 and the plurality of lower forming tools 32 which are mounted respectively on the punch holder unit 2 and on the die holder unit 12.

The punching apparatus 1 also allows a plurality of different forming or deformation workings to be performed, with the workpiece 10 stationary or moved along two mutually orthogonal and substantially horizontal directions.

The punching apparatus 1 comprises a punch holder unit 2 and a die holder unit 12 having a simple and compact structure and small dimensions.

The invention further concerns a punching machine comprising at least one punching apparatus 1 of the invention as described above and illustrated in figures 1 to 14.

Claims

CLAIMS . Punching apparatus (1) for forming and/or deformation workings on a workpiece (100) and associable with a punching machine, comprising:

- a punch holder unit (2) which includes an upper support body (3) rotatable about a working axis (X), a punch holder body (4) that is rotatably connected to said upper support body (3) and arranged to slidably house a plurality of upper forming tools (31), and an upper beating element (5) that is slidably supported by said upper support body (3) and is movable parallel to said working axis (X) to selectively interact with an established upper forming tool (31) so as to partially push it outside the punch holder body (4) to interact with said workpiece (100);

- a die holder unit (12) comprising a lower support body (13) rotatable about said working axis (X), a die holder body (14) fixed to said lower support body (13) and arranged to slidably house a plurality of lower forming tools (32), and a lower beating element (15) housed in said lower support body (13) and movable linearly along and rotatably about said working axis (X) to selectively interact with an established lower forming tool (32), said lower beating element (15) being movable linearly between an non-operative position (A), in which said lower beating element (15) is locked in rotation by first stop means (21) and does not rotate with said lower support body (13), a first operative position (B), in which said lower beating element (15) is connected by second stop means (22) to said lower support body (13) so as to rotate together with the lower support body about said working axis (X), and a second operative position (C), in which said lower beating element (15) pushes said established lower forming tool (32) partially outside the die holder body (14) so as to interact with said workpiece (100). Punching apparatus (1) according to claim 1, wherein said die holder body (14) comprises a plurality of lower seats (16) each of which being suitable to receive a lower tool holder element (34) to which a respective lower forming tool (32) is associated, said lower tool holder element (34) comprising a first end (34a) configured to receive and support said respective lower forming tool (32) and a second end (34b) suitable to interact with said lower beating element (15). Punching apparatus (1) according to claim 1 or 2, wherein said lower beating element (15) is slidably connected to said die holder body (14) by means of a first guide pin (20) having a first upper end (20a) fixed to said die holder body (14) and a second lower end (20b) that is slidably coupled to a seat (27) of said lower beating element (15), in particular said first guide pin (20) being substantially coaxial to said working axis (X). Punching apparatus (1) according to any preceding claim, comprising first elastic means (28) interposed between said lower beating element (15) and said die holder body (14) and configured to elastically keep said lower beating element (15) spaced apart from said die holder body (14) in said non-operative position (A). Punching apparatus (1) according to any preceding claim, wherein said die holder unit (12) comprises a plurality of lower thrust elements (17) that are slidably connected to said die holder body (14) and arranged to support respective lower tool holder elements (34) of said lower forming tools (32), wherein each lower thrust element (17) can be abutted and moved along said working axis (X) by said lower beating element (15) so as to move the respective lower tool holder element (34) and the relative lower forming tool (32). Punching apparatus (1) according to claim 5, wherein said die holder unit (12) comprises second elastic means (18) interposed between each lower thrust element (17) and said die holder body (14) and configured to keep said lower thrust elements (17) elastically spaced apart from said die holder body (14) in a respective non-operative position (E) when said lower thrust elements are not abutted and pushed by said lower beating element (15). Punching apparatus (1) according to any preceding claim, wherein said first stop means (21) comprise a first tab configured to engage a longitudinal groove (24), in particular parallel to said working axis (X), made on an external wall of said lower beating element (15) and wherein said second stop means (22) comprise a second tab fixed to said second support body (13) and configured to engage said longitudinal groove (24). Punching apparatus (1) according to any preceding claim, comprising driving means (25, 26) acting on said lower beating element (15) to move it linearly in said operative positions (B, C) along a thrust direction (F). Punching apparatus (1) according to claim 8, wherein said driving means (25, 26) comprise a first linear actuator (25) adapted to move said lower beating element (15) between said non-operative position (A) and said first operative position (B) and a second linear actuator (26) adapted to move said lower beating element (15) between said first operative position (B) and said second operative position (C). Punching apparatus (1) according to claim 1, wherein said die holder body (14) comprises an upper wall (14a) adapted to abut and support said workpiece (100), wherein in said upper wall (14a) there are a plurality of lower seats (16) each of which being adapted to receive a lower tool holder element (34) to which a respective lower forming tool (32) is associated. Punching apparatus (1) according to any preceding claim, wherein said punch holder body (4) comprises a plurality of upper seats (6) each of which is adapted to receive a respective upper thrust element (7) and an upper tool holder element (33) associated with a corresponding upper forming tool (31), said upper thrust element (7) being interposed between said upper beating element (5) and said upper tool holder element (33). Punching apparatus (1) according to claim 11, wherein each upper thrust element (7) comprises an abutment end (7a) configured to interact with a respective beating portion (5a) of said upper beating element (5) and a connecting end (7b) that is coupled to said upper tool holder element (33). Punching apparatus (1) according to any preceding claim, wherein said punch holder unit (2) comprising an abutment element (8) slidably connected to said upper support body (3) and to which said upper beating element (5) is fixed, in particular said abutment element (8) being configured to interact with a ram element of the punching machine. Punching apparatus (1) according to any preceding claim, wherein said upper support body (3) comprises a through seat (9) suitable for receiving and slidably guiding said upper beating element (5). Punching machine comprising a punching apparatus (1) according to any preceding claim.