PROCESSING MACHINE, WORKPIECE TABLE AND METHOD FOR PROCESSING A WORKPIECE

Abstract

The invention relates to a machine tool (10), in particular a long folding machine, for machining a workpiece (12) made of flat material such as sheet metal, comprising: a workpiece table (14) defining a supporting area (16) on which the workpiece (12) can be placed at least in sections during machining; and at least one machining unit (18) for machining the workpiece (12). The workpiece table (14) comprises at least one table assembly (20) having a base plate (22) and a swivel plate (24), the base plate (22) and the swivel plate (24) each defining a portion of the supporting area (16), wherein the swivel plate (24) is pivotably mounted relative to the base plate (22) in such a way that a swivel movement of the swivel plate (44) can be generated for turning the workpiece (12) over. The invention further relates to a workpiece table and a method for machining a workpiece made of flat material.

Claims

1. A long folding machine for machining a workpiece made of sheet metal, comprising: a workpiece table defining a supporting area on which the workpiece can be placed at least in sections during machining; and at least one machining unit for machining the workpiece while the workpiece is placed on the supporting area; wherein the workpiece table comprises at least one table assembly having a base plate and a swivel plate, the base plate and the swivel plate each defining a portion of the supporting area, and wherein the swivel plate is pivotably mounted relative to the base plate in such a way that a swivel movement of the swivel plate can be generated for turning the workpiece over.

2. The long folding machine of claim 1, further comprising a receiving area in which the workpiece can be arranged at least in sections during machining, wherein the swivel plate is arranged and/or can be arranged outside the receiving area for turnover.

3. The long folding machine of claim 1, wherein the machining unit is configured to bend a portion of the workpiece to be bent over relative to a clamped portion of the workpiece about a bending axis, and wherein the swivel movement of the swivel plate is defined by at least one swivel axis arranged parallel to the bending axis.

4. The long folding machine of claim 1, wherein the table assembly comprises a holding unit configured to keep the workpiece stationary relative to the swivel plate for turnover so that the workpiece, when held, follows a movement of the swivel plate.

5. The long folding machine of claim 4, wherein the holding unit is configured to hold the workpiece by means of negative pressure.

6. The long folding machine of claim 4, wherein the holding unit comprises at least one holding member that is movable relative to the swivel plate and configured to selectively clamp and release the workpiece on the swivel plate.

7. The long folding machine of claim 1, further comprising a movement device configured to automatically generate the swivel movement of the swivel plate.

8. The long folding machine of claim 7, wherein the movement device comprises a separate drive for the swivel plate.

9. The long folding machine of claim 7, wherein the movement device comprises a force transmission configured to transmit an actuating force for generating the swivel movement from a location away from the swivel plate to the swivel plate.

10. The long folding machine of claim 7, wherein the movement device comprises at least one force transducer that converts a generated actuating force into a force required to generate the swivel movement.

11. The long folding machine of claim 1, wherein the machining unit is configured to provide an actuating force to generate the swivel movement.

12. The long folding machine of claim 1, wherein the swivel plate is pivotable from a non-swiveled state by at least 90 degrees, preferably by at least 120 degrees and in particular by 180 degrees.

13. The long folding machine of claim 1, wherein in a state in which the swivel plate is swiveled to a maximum degree, a gap remains between the swivel plate and the base plate, in particular a gap having a thickness of at least 3 mm, preferably of at least 4 mm and particularly preferably of at least 5 mm.

14. The long folding machine of claim 1, wherein die table assembly comprises at least one coupling joint that pivotably couples the swivel plate to the base plate and that defines a movement path of the swivel plate that deviates from a circular path.

15. The long folding machine of claim 1, further comprising a machine frame, wherein the table assembly is linearly movable relative to the machine frame.

16. The long folding machine of claim 1, further comprising a handling device configured to move the workpiece relative to the table assembly for handling before, during and/or after machining and to fix the workpiece as required, wherein the handling device comprises at least one handling member configured to mechanically act on the workpiece to advance it onto the swivel plate before turning it over.

17. (canceled)

18. A method for machining a workpiece made of sheet metal using a long folding machine, in particular using a long folding machine of claim 1, wherein the machine tool comprises a workpiece table defining a supporting area on which the workpiece can be placed at least in sections during machining, wherein the long folding machine further comprises at least one machining unit for machining the workpiece, and wherein the workpiece table comprises at least one table assembly having a base plate and a swivel plate, wherein the base plate and the swivel plate each define a portion of the supporting area, and wherein the swivel plate is pivotally mounted relative to the base plate, the method comprising: placing the workpiece onto the supporting area; machining the workpiece; generating a swivel movement of the swivel plate to turn the workpiece over; and machining the turned-over workpiece.

19. The method of claim 18, further comprising: advancing the workpiece onto the swivel plate such that the entire workpiece is pushed off the base plate before the swivel movement for turning the workpiece over is generated.

Description

[0042] Below, the present invention is described by way of example with reference to the accompanying figures. The drawing, the specification and the claims contain combinations of numerous features. The skilled person will appropriately consider the features also individually and use them in useful combinations within the scope of the claims. In the drawings:

[0043] FIG. 1 is a schematic perspective representation of a machine tool comprising a workpiece table;

[0044] FIG. 2 is a schematic side view of a section of the machine tool comprising a workpiece table in a totally non-swiveled state;

[0045] FIG. 3 is a schematic side view of a section of the machine tool comprising a workpiece table in a partially swiveled state;

[0046] FIG. 4 is a schematic side view of a section of the machine tool comprising a workpiece table in a fully swiveled state;

[0047] FIG. 5 is a schematic side view of an alternative embodiment of a table assembly of a workpiece table;

[0048] FIG. 6 is a schematic side view of a further alternative embodiment of a table assembly of a workpiece table;

[0049] FIG. 7 is a schematic top view of a section of the table assembly according to the further alternative embodiment;

[0050] FIG. 8 is a schematic representation of a section of yet another alternative embodiment of a table assembly;

[0051] FIG. 9 is a schematic representation of a section of yet another alternative embodiment of a table assembly; and

[0052] FIG. 10 is a schematic flow chart of a method for machining a workpiece made of flat material.

[0053] FIG. 1 is a schematic perspective representation of a machine tool 10 according to the invention. In this exemplary embodiment, the machine tool 10 is configured as a long folding machine. However, the specification below is to be understood as meaning that in other embodiments, the machine tool 10 can also be a press, punching machine, bending machine, etc.

[0054] The machine tool 10 is configured to machine a workpiece 12 (cf. FIG. 2). In the present case, the machine tool 10 is configured to machine a workpiece 12 made of flat material, such as sheet metal, as is known by bending it several times about a bending axis 32. The machine tool 10 has a machine frame 50. The machine tool 10 further has a workpiece table 14 defining a supporting area 16 on which the workpiece 12 can be placed during machining.

[0055] The machine tool 10 comprises a control unit 11. It may be connected to a display device that serves as a user interface or is part of such a user interface. It is understood that the functions of the machine tool 10 described below can be controlled by the control unit 11. Accordingly, the control unit 11 may comprise a computer-readable medium with suitable program code.

[0056] The machine tool 10 further comprises a clamping jaw 56 and another clamping jaw 57 which can be used to clamp the workpiece 12 in place during machining. At least one of the clamping jaws 56, 57 is movable relative to the machine frame 50. In the case illustrated, the other clamping jaw 57, configured as an upper clamping jaw, can be swiveled upwards relative to the machine frame. In addition, at least one of the clamping jaws 56, 57 can be linearly and/or pivotably movable relative to the workpiece table 14.

[0057] The machine tool 10 defines a receiving area 26 in which the workpiece 12 is arranged at least in sections during machining. In the case illustrated, the receiving area 26 is arranged between the clamping jaws 56, 57. During machining, the workpiece partially protrudes between the clamping jaws 56, 57 from the receiving area 26. This defines a clamped portion 30 and a portion 28 of the workpiece 12 to be bent. In FIG. 2, these two portions 28, 30 each have a reference sign, wherein it is understood that bending of the workpiece 12 about the bending axis 32 has already taken place to obtain the workpiece geometry shown in FIG. 2. This means that for this purpose, the portion 28 to be bent was bent downwards relative to the clamped portion 30.

[0058] The machine tool 10 comprises a machining unit 18 and another machining unit 19. They are briefly described with reference to FIG. 2. The machining unit 18 is attached to the clamping jaw 56. The machining unit 18 comprises a base member 58. In the case illustrated, the base member 58 is wedge-shaped. The base member 58 is mounted for linear movement on a surface of the clamping jaw 56. The machining unit 18 further comprises a machining tool 60. The machining tool 60 is again mounted for linear movement on a surface of the base member 58. A movement path of the machining tool 60 can thus be generated by moving the base member 58 relative to the clamping jaw 56 and/or the machining tool 60 relative to the base member 58. DE 10 2018 000344 B3, for example, describes how such a bending unit works.

[0059] In the illustrated case, moreover, the further bending unit 19 is attached to the further clamping jaw 57. The further bending unit 19 is constructed in the same way as the bending unit 18. The two bending units 18, 19 can thus be used to bend the workpiece either upwards or downwards about the bending axis 32.

[0060] In the following, reference is made once more to FIG. 1. The workpiece table 14 comprises at least one table assembly 20 having a base plate 22 and a swivel plate 24. In the case illustrated, the workpiece table 14 comprises several table assemblies. They can be configured identically or differently. It may, in particular, be provided that only some or one of the table assemblies have a swivel plate.

[0061] The base plate 22 and the swivel plate 24 each define a portion of the supporting area 16. The swivel plate 24 is pivotably mounted relative to the base plate 22 in such a way that a swivel movement can be generated which can be used to turn the workpiece 12 over. Upon turning the workpiece 12 over, its top side is turned downwards and its bottom side is turned upwards.

[0062] The swivel plate 24 forms a front end of the table assembly 20. In other words, the swivel plate 24 defines a region at the very front of the supporting area 16. The term front refers to the side of the bending machine 10 on which the machining units 18, 19 are arranged. The machine tool 10 is loaded from this side.

[0063] In other embodiments, the swivel plate may form a back end of the table assembly. This may be the case, for example, in machines whose workpiece table is accessible from both the front and the rear. If, for example, for a specific machining operation, the workpiece is intended to be placed onto the workpiece table from a first side of the machine, the swivel plate may be arranged behind the base plate when viewed from this first side. The swivel plate may be arranged on a second side of the machine, which is opposite the first side.

[0064] The table assembly 20 is linearly movable relative to the machine frame 50. Specifically, the table assembly 20 may be movable perpendicular to the bending axis 32. The table assembly 20 may be partially moved out of the receiving area 26 and/or moved back into it.

[0065] In the case of the long folding machine illustrated, to bend the workpiece 12, the table assembly 20 is moved back to the point that only the workpiece 12 protrudes from between the clamping jaws 56, 57. A respective protruding portion to be bent can thus be bent upwards or downwards towards one of the clamping jaws without the table assembly 20 impeding the bending movement.

[0066] The machine tool 10 or the workpiece table 14 further comprises a handling device 52. It is configured to move the workpiece 12 relative to the table assembly 20. In the case illustrated, several handling devices 52 are present, only one having a reference sign. The handling device 52 has a handling member 50 configured to mechanically act on the workpiece 12. For example, the handling member 50 is pivotable towards the surface of the workpiece 12 and/or can be lifted away from it, which makes it possible to selectively hold the workpiece 12 on the supporting area 16. In addition, the handling member 50 may be movable relative to the table assembly 20, which makes the workpiece 12 movable in the supporting area 16. Using the handling device 52, the workpiece 12 can be pushed forwards or pulled backwards on the table assembly 20, for example to move it out of the receiving area 26. The handling device 52 may further be used to hold the workpiece 12 on the supporting area 16 during machining.

[0067] FIG. 2 to FIG. 4 illustrate a section of the machine tool 10. The representations serve to illustrate turnover of the workpiece 12. In FIG. 2 to FIG. 4, some reference signs have been omitted for the sake of clarity.

[0068] Before turnover, the workpiece 12 is completely pushed forwards onto the swivel plate 24. Then, it no longer rests on the portion of the supporting area 16 defined by the base plate 22. This may be performed when the table assembly 20 is retracted, for example with the handling device 52.

[0069] The table assembly 20 comprises a holding unit 34. The holding unit 34 comprises one or more holding members 36, only one having a reference sign for the sake of clarity. The holding members 36 are configured on or in the swivel plate 24. In the embodiment shown, the holding members 36 are suction cups. They are connected to a negative pressure generator, e. g. a vacuum pump or the like, via compressed air lines (not illustrated) running through the swivel plate 24 and the base plate 22. The negative pressure generator is arranged, for example, on the machine frame 50.

[0070] In other embodiments, a movable clamping device that can selectively fix the workpiece 12 to the swivel plate 24 mechanically may serve as the holding member. According to the invention, switchable and/or magnetic holding members may also be used.

[0071] Irrespective of the exact design of the holding member 36, it is configured to either keep the workpiece 12 stationary relative to the swivel plate 24 or to release it. When held, the workpiece 12 moves with the swivel plate 24 when the latter is swiveled. The swivel movement of the swivel plate 24 may thus serve as a turnover movement for the workpiece 12. When released, on the other hand, the workpiece 12 is movable relative to the swivel plate 24.

[0072] Starting from the totally non-swiveled state of the swivel plate 24 as shown in FIG. 2, in which the workpiece 12 is fully advanced onto the swivel plate, the swivel plate 24 is swiveled about a swivel axis 33. As a result, a bottom side of the workpiece 12, which rests on the swivel plate 24, becomes the new top side of the workpiece 12 while a top side of the workpiece 12 rests on the base plate 22, being the bottom side after turnover. The swivel axis 33 is arranged parallel to the bending axis 32.

[0073] As can be seen in FIG. 7, a gap 46 is formed between the base plate 22 and the swivel plate 24 when the swivel plate 24 is fully swiveled. This gap 46 can be several millimeters thick so that the workpiece 12 may be accommodated in the gap 46 when the swivel plate 24 is fully swiveled. The swivel movement of the swivel plate 24 may thus be performed to such an extent that the workpiece 12 is completely turned over before being released by the holding unit 34. In the case illustrated, a maximum swivel angle of 180? is provided.

[0074] In other embodiments, the gap 46 may be omitted and/or the maximum swivel angle may be smaller.

[0075] Turning the workpiece 12 over may include the workpiece 12 being released by the holding unit 34 and the workpiece 12 subsequently sliding and/or falling onto the base plate 22. This may occur if the entire available swivel angle is not utilized or even if the maximum swivel angle is less than 180?.

[0076] In the following, reference is made once more to FIG. 1. The machine tool 10 comprises a movement device 38 configured to automatically generate the swivel movement of the swivel plate 24. The movement device 38 may be connected to the control unit 11. In the case illustrated, the movement device 38 comprises a separate drive 40. The movement device 38 and the separate drive 40 are only shown schematically. Various drives can be used, such as hydraulic cylinders, air cylinders, threaded spindles, gearboxes with various drives, linear actuators, etc.

[0077] In the exemplary embodiment according to FIG. 1, the separate drive 40 is arranged at a distance from the swivel plate 24. The movement device 38 hence comprises a force transmission such as a Bowden cable, a hydraulic line, a compressed air line, a belt, a chain, a gearbox or the like to transmit an actuating movement generated by the separate drive 40 to the swivel plate 24.

[0078] Alternatively, a separate drive may be provided directly on and/or in the swivel plate 24. For example, an electric motor may be provided directly in the area of an articulated connection of the swivel plate 24 to the base plate 22, which can optionally be supplied with electrical energy to generate the swivel movement of the swivel plate 24.

[0079] Further variants relating to the generation of the swivel movement of the swivel plate 24 are described below with reference to FIG. 6 to FIG. 9.

[0080] FIG. 5 shows a further embodiment of a table assembly 120. It may be used as an alternative to the table assembly 20 described above. Similarly, the table assembly 120 comprises a base plate 122 and a swivel plate 124. The table assembly 120 comprises a coupling joint 148 that pivotably couples the swivel plate 124 to the base plate 122 and that defines a movement path of the swivel plate 124 that deviates from a circular path. The coupling joint 148 is only shown schematically, and its individual joints are not shown in detail. The coupling joint 148 may be configured in any suitable manner and may include a plurality of rigid members connected by joints. The coupling joint 148 may be a spatial mechanism. A complex swivel movement may thus be defined, including, for example, a sweeping movement preventing the workpiece 12 from being pinched at an edge during turnover.

[0081] In one embodiment, the coupling joint 148 is adjustable so that the movement path is variable. This may be automated or manual. The swivel movement may thus be adjustable to the geometry of a workpiece to be turned over so that it can be turned over in a targeted and/or damage-free manner even if it has already been machined and has one or more bending points, for example.

[0082] FIG. 6 and FIG. 7 illustrate another embodiment. This embodiment uses a table assembly 220 having a base plate 222 and a swivel plate 224 mounted on it so as to swivel about a swivel axis 233. The table assembly 220 comprises a movement device 238 with a force transmission 242 configured to transmit an actuating force for generating the swivel movement from a location away from the swivel plate 224 to the swivel plate 224. The force transmission 242 is shown by way of example only and may be configured to transmit a tensile force and/or a compressive force. As mentioned above, any suitable force transmission may be used. In general, according to the invention it may also be provided that the swivel plate 224 is spring-biased, in particular damped, and automatically returns into its totally non-swiveled state, for example if there is no actuating force, or automatically moves into a state in which it is sviveled to a maximum degree if there is no actuating force.

[0083] As in the embodiment described above, the movement device 238 may comprise a separate drive. An actuating force provided by the separate drive may then be transmitted to the swivel plate 224 through the force transmission 242.

[0084] In the embodiment according to FIG. 6 and FIG. 7, the movement device 238 further comprises a force transducer 244. Such force transducer 244 converts an actuating force for generating the swivel movement of the swivel plate 224. In the example illustrated, the force transducer 244 is a lever. It is formed by the swivel plate 244 itself. The force transducer 244 protrudes beyond the swivel axis towards the base plate 222. This protrusion may be used as a lever as the force transmission 242 engages it. As schematically illustrated in FIG. 7, there may be several protrusions, for example if force is to be transmitted to the swivel plate 224 at several points.

[0085] In certain embodiments, the machining unit 18 and/or the machining unit 19 may be configured to provide an actuating force to generate the swivel movement. It is understood that this may also be the case for other types of machine tools and correspondingly differently configured machining units. For this purpose, a movement device may be designed in such a way that a movement provided by the corresponding machining unit is transmitted to the swivel plate. In the implementations according to FIG. 6 and FIG. 7, for example, the machining unit 18 may act on an end of the force transmission 242 that is not shown.

[0086] FIG. 8 and FIG. 9 schematically show embodiments in which a machining unit serves to provide the actuating force for the swivel plate. Each of the figures shows a portion of a base plate 322, 422 of a table assembly 320, 420. A swivel plate is connected to each of them, as described above in connection with other implementations.

[0087] In the embodiment according to FIG. 8, a movement device 338 comprises a force introduction member 362 configured to enable the introduction of force from a machining unit. In the case illustrated, the force introduction member 362 is configured as a lever on which a machining tool 360 of a machining unit not shown in more detail can act. The force introduction member 362 is mounted on the base plate 322 such that it can be swiveled in two directions. Moving the force introduction member 362 in a first direction causes the swivel plate to swivel towards the base plate 322 while moving it in the opposite direction causes the swivel plate to swivel back into its totally non-swiveled state. The schematically illustrated force transmission 342 may, for example, be a linkage. However, one or more hydraulic lines, Bowden cables, belts, chains, etc. may also be used, in combination if applicable.

[0088] In the embodiment according to FIG. 9, a movement device 438 comprises a force introduction 442 comprising two force introduction members 462, 464. Each of them is configured as a hydraulic cylinder and connected to a separate hydraulic line leading to the swivel plate not shown and connected to an actuating mechanism for the swivel plate. It may also be provided that each of the force introduction members is a lever actuating a linkage or the like. Furthermore, the force introduction members may be connected to Bowden cables. The force introduction members 462, 464 are each arranged and configured such that a machining tool 460 of a machining unit not shown in more detail can act on them. Actuation of a first force introduction member 462 causes the swivel plate to swivel towards the base plate 422. Actuation of a second force introduction member 462 causes the swivel plate to swivel back into its totally non-swiveled state. The force introduction members 462, 464 may optionally be configured to react to a compressive force or a tensile force applied by the machining tool 460.

[0089] Instead of the machining unit acting on a force introduction member, one or more stops acting on a force introduction member upon movement of the table assembly 20 relative to the machine frame 50 may be provided. The swivel movement is then generated by moving the table assembly 20. The corresponding force introduction member may be arranged either directly on the swivel plate 24 or on a force transmission's end spaced from it.

[0090] FIG. 10 is a schematic flow chart of a method for machining a workpiece made of flat material. Below, the method is explained by way of example for implementation using the machine tool 10 described above. However, it is understood that the method can also be performed using another machine tool having a corresponding workpiece table.

[0091] In method step S1, the workpiece 12 is placed onto the supporting area 16.

[0092] In method step S2, the workpiece 12 is machined. For example, the workpiece 12 is bent downwards about the bending axis 32.

[0093] In an optional method step S3, the workpiece 12 is advanced onto the swivel plate 24 such that the entire workpiece is pushed off the base plate 22. This is performed with the handling device 52, for example. Alternatively or additionally, the optional method step S3 may include extending the table assembly 20.

[0094] In an optional method step S4, the workpiece 12 is temporarily fixed to the swivel plate 24. This can be done, for example, with the holding unit 34 described above.

[0095] In method step S5, a swivel movement of the swivel plate 24 is generated to turn the workpiece 12 over. The swivel plate 24 may be arranged outside the receiving area 26. The workpiece 12 can thus be swiveled completely outside the receiving area 26. If the workpiece 12 is temporarily fixed to the swivel plate 24, it completely follows the movement of the swivel plate 24. In other variants, it may also be provided that the workpiece 12 can move relative to the swivel plate 24. For example, the workpiece 12 can then be turned over by resting one of its edges against a holding member spaced from the swivel plate 24 and thus ensuring that the workpiece 12 slides relative to the swivel plate 24 rather than being moved in an uncontrolled manner.

[0096] In an optional method step S6, the workpiece 12 is partially retracted or pushed back onto the base plate 22 as required. Alternatively or additionally, the optional method step S6 may include retracting the table assembly 20.

[0097] In method step S7, the turned-over workpiece 12 is finally machined.