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(11) | EP 4 834 501 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | BENDING PRESS |
| (57) A press brake is described for bending a workpiece comprising a fixed frame; lower
bending table and an upper bending table. The press has also a first horizontal guide
mounted on the frame in front of said tables; a second horizontal guide mounted on
the frame behind said tables; and a first and second movable picker configured to
pick up tools from storage units and mount them on the tables.
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[0002] Known press brakes feature a pair of carriages that work together to set up the pressing table. A manipulator prepares a train of tools for the pair of carriages, after which one carriage inserts the head tool and the other carriage the tail tool via a respective protruding pin with which it can hook the tool. See also: https://www.youtube.com/watch?v=uTSN XXO8f8.
[0003] The two carriages are translated horizontally to drag the stacked and aligned train of tools along a horizontal guide so far as the designated bending table. Disadvantageously, the adjustment operations on the tools before dragging them on the pressing table slow down the setup speed, and the system only allows the use of single-size tools. Larger tools are formed by placing multiple tools of the same size side by side. Furthermore, this system severely limits the freedom to setup tools on the pressing table and in the tool storage unit. Consider, for example, the case wherein the tool furthest from the storage unit needs to be removed from the pressing table: all the other tools in the row must then be removed to create a clear path for retrieving that last tool. Clearly, this translates into long cycle times and/or inconvenient constraints in the arrangement of the tools on the pressing table during bending.
[0004] The main object of the invention is to eliminate or mitigate the aforementioned drawbacks by creating a different press brake.
[0005] Another object is to increase the speed of setting up the pressing tables while maintaining the flexibility of the press brake with tools of different sizes.
[0006] Another object is to reduce the setup cycle time and/or increase the freedom of arrangement of the tools on the pressing tables during bending.
[0008] In one embodiment, a press brake for bending a workpiece comprises:
- a fixed frame;
- a lower bending table which is fixed to the frame and adapted to receive one or more dies;
- an upper bending table that is
adapted to receive one or more bending punches and
movable relative to the frame towards the lower table to press the piece between a die and a punch;
- a first horizontal guide mounted on the frame in front of said tables;
- a second horizontal guide mounted on the frame behind said tables;
- a first movable picker
coupled to the first horizontal guide to move horizontally from a punch storage unit towards the upper table and
configured to pick up a punch from the punch storage unit and mount it on the upper table, or vice versa;
- a second movable picker
coupled with the second horizontal guide to move horizontally from a die storage unit towards the lower table and
configured to pick up a die from the die storage unit and mount it on the lower table, or vice versa.
[0009] With the aforementioned two pickers, the overall assembly of the tools on the tables is faster. Also the table setup is faster because the two pickers work together to assemble the dies and punches simultaneously and independently.
[0011] The particular positioning of the pickers, one in front and one behind the tables, is advantageous because it exploits all the free space available on the press brake near the tables, and creates two independent paths for the pickers, which can work without getting in each other's way.
[0012] In one embodiment, to transfer the punches and dies from their respective tables to their respective storage units and vice versa, the press comprises only said first and second picker, for efficiency.
[0013] In one embodiment the press comprises a programmed or programmable processing unit (e.g. a PC or PLC) for generating control signals for
moving the first picker along the first horizontal guide to pick a punch from the punch storage unit and mount it on the upper table, and
at the same time moving the second picker along the second horizontal guide to pick up a die from the die storage unit and mount it on the lower table.
[0014] In one embodiment the first and/or second picker is a carriage which is
slidable on the respective horizontal guide, and
provided with a head provided with a gripping member, e.g. a pin, which gripping member is
preferably horizontally retractable, and
configured to engage a corresponding through cavity in a punch or die for pick it up.
[0015] To facilitate the tool trajectories parallel to said guides, in one embodiment
said head is mounted movable on the rest of the carriage so that it can move along a vertical axis with respect to the rest of the carriage, and/or
said head is mounted movable with respect to the rest of the carriage in order to be able to move, together with the rest of the carriage, along a horizontal axis orthogonal to the longitudinal axis of the horizontal guide (i.e. orthogonal to a plane containing at least one of said tables), and/or
the first and second horizontal guides are offset horizontally, that is they lie on vertical planes that are parallel to each other, different and offset.
[0016] In one embodiment, the first and second horizontal guide are vertically offset, that is they lie on horizontal planes that are parallel to each other, different, and offset.
[0017] In particular, the first guide is mounted higher than the second guide, to be closer to the upper table and shorten the trajectories of the first picker.
[0018] In one embodiment, the punch storage unit and the die storage unit coincide, for efficiency, that is, there is only one storage unit from which the pickers take tools.
[0019] In one embodiment, the punch storage unit and the die storage unit are distinct and separate components of the press brake, to increase setup speed.
[0020] In one embodiment, the press brake comprises a die storage unit containing, or adapted to contain, only a plurality of dies, the first picker being configured to pick up dies only from the die storage unit and place them on the lower table.
[0021] In one embodiment, the press brake comprises a punch storage unit containing, or adapted to contain, only a plurality of punches, the second picker being configured to pick up punches only from the punch storage unit and place them on the upper table.
[0022] In one embodiment, the press brake comprises the die storage unit and the punch storage unit, preferably integrated into the fixed frame.
[0023] To facilitate the trajectories of the pickers, in one embodiment
the die storage unit and the punch storage unit are arranged horizontally next to each other, wherein preferably the die storage unit is adjacent to the lower table, and/or
the die storage unit is placed between the punch storage unit and the lower table.
[0024] To facilitate the trajectories of the pickers, in one embodiment the gripping member of the first picker faces the second horizontal guide, and/or the gripping member of the second picker faces the first horizontal guide.
[0025] In one embodiment the die storage unit comprises:
- a plurality of linear supports, capable of storing a row of aligned dies, which are arranged in a row on a horizontal plane lying at a lower level than that of the second horizontal guide; and
- a lifting mechanism for picking up and vertically lifting one linear support of said plurality with respect to said horizontal plane in order to select one row of dies from the others and position it in front of the second picker.
[0026] In one embodiment the punch storage unit comprises:
- a portal;
- a plurality of punch racks mounted movably and in a horizontal row in the portal,
wherein
each rack comprises horizontal rows of aligned punches,
the horizontal rows of punches aligned in each rack being arranged vertically offset on a same vertical plane;
- a lifting mechanism to pick up and vertically lift a rack to select a row of punches from the others and position it in front of the first picker.
[0027] In one embodiment, in the punch storage unit the portal comprises:
- a containment structure for the racks;
- a bridge structure extending vertically from the containment structure and comprising
two vertical guides in which the opposite ends of the rack raised by the lifting mechanism
are slidable,
the containment structure comprising means for horizontally translating the plurality of racks relative to the bridge structure, and
the bridge structure comprising means for vertically translating one rack of the plurality.
[0028] A rack has a variable mass, because it can be full of tools or empty (e.g. it ranges from 200 to 400 kg). By placing said means for moving the plurality of racks in the containment structure, such means are in a lower position with respect to the bridge structure and do not induce vibrations or deformations on the raised rack. This ensures a more precise grip of the punch by the first picker.
[0029] A preferred method comprises the steps of
- releasing the punch from a tool storage unit via the first picker and
- transferring the punch to the first picker,
- moving the first picker with the punch on board as far as the upper table keeping the punch suspended at a certain horizontal distance from the upper table and/or at a certain distance below the upper table; and
- moving the punch closer to the upper table (e.g. by going up vertically); and
- mounting the punch on the upper table by transferring the punch from the first picker to the upper table, or vice versa.
[0030] To pick up a die from a tool storage unit and mount it on the lower table or vice versa, a preferred method comprises the steps of
- releasing the die from a tool storage unit via the second picker and
- transferring the die to the second picker;
- moving the second picker with the die on board as far as the lower table keeping the die suspended at a certain horizontal distance from the upper table and/or at a certain distance above the lower table, and
- moving the die closer to the lower table (e.g. by going down vertically); and
- mounting the die on the lower table by transferring the die from the second picker to the lower table, or vice versa.
[0031] In one embodiment, the method envisages
- releasing the punch from a tool storage unit via the first picker by inserting a locking pin provided in the first picker into a cavity of the punch;
- transferring the punch to the first picker by lifting the punch using a locking pin provided in the first picker;
- bringing the punch suspended to the upper table holding the punch on a locking pin provided in the first picker,
- mounting the punch on the upper table by transferring the punch from a locking pin in the first picker to the upper table.
[0032] In a preferred step, a punch is brought from a tool storage unit to a pre-established point on the upper table via the first picker with the steps of
- taking the punch from a tool storage unit;
- and, always keeping the punch suspended in the air by means of the first picker,
- moving the suspended punch orthogonally to the first guide towards the outside, or the inside, of the press to move it away from the tool storage unit;
- moving the suspended punch parallel to the first guide towards said point;
- moving the suspended punch orthogonally to the first horizontal guide towards the inside, or outside, of the press to mount it at said point.
[0033] This method allows the tool to be temporarily removed from the guides and other tools coupled to the guides, allowing a tool to be removed from one row of tools or inserted between two rows of tools. This enhances the press's ability to assemble or disassemble a train of tools even by placing or moving individual tools.
[0034] The previous steps are valid only or also for a die, mutatis mutandis (i.e. using the second picker, the lower table and the second horizontal guide).
[0035] Each of the variants defined above can be implemented alone or in combination with one or each of the others.
[0036] The advantages of the invention will be further clarified by preferred embodiments described below with reference to the accompanying drawings, wherein:
- Figure 1 shows a three-dimensional view of a press brake;
- Figure 2 shows a three-dimensional view of the isolated components of the press brake;
- Figure 3 shows a three-dimensional view of a die storage unit;
- Figure 4 shows a three-dimensional view of a punch storage unit.
[0037] Equal numbers in the figures indicate equal or substantially equal parts. To avoid cluttering the drawings, identical members are sometimes left unnumbered.
[0038] Let's define a set of Cartesian directions or axes XYZ, where X and Y are horizontal directions or axes that are orthogonal to each other and Z is the vertical direction or axis that is orthogonal to the XY plane. For brevity, expressions such as "along X" mean along an axis that is coincident with or parallel to the X axis.
[0039] A press brake 10 comprises:
- a C-shaped frame 12 having a lower portion 14 and an upper portion 16 corresponding to the ends of the C;
- a fixed lower table 18 for receiving a bending die which is integral with the lower portion 14;
- an upper table 22, for receiving a bending punch, which is mounted vertically translatable on the upper portion 16 to be translated vertically along Z with respect to and toward the fixed table 18 in order to effect a bending of a workpiece placed between a punch and a die.
[0040] The table 22 is movable by a drive 28, e.g. two pneumatic cylinders, mounted on the frame 12 and connected to opposite ends of the table 22 respectively.
[0041] To equip the tables 18, 22 with the necessary tools, the press brake 10 comprises two pickers 30, 50, e.g. shuttle carriages, which are movable on respective horizontal guides 32, 52 extending along X.
[0042] The horizontal guide 32 is mounted on the frame 12 in front of the tables 18, 22 while the horizontal guide 52 is mounted on the frame 12 behind the tables 18, 22.
[0043] The first picker 30 is coupled to the guide 32 to move horizontally from a punch storage unit 70 to the upper table 22 and is configured to pick up a punch from the punch storage unit 70 and mount it on the upper table 22, or vice versa.
[0044] The second picker 50 is coupled to the guide 52 to move horizontally from a die storage unit 90 to the lower table 18 and is configured to pick up a die from the die storage unit 90 and mount it on the lower table 18, or vice versa.
[0045] With the pickers 30, 50 and the guides 32, 52 respectively in front and behind the tables 18, 22, it is possible to exploit all the free space available on the press brake near the tables 18. 22, and the paths for the pickers 30, 50 do not intersect. Therefore the pickers 30, 50 can work simultaneously and independently.
[0046] Preferably the press 10 comprises a processing unit 100 programmed or programmable for
moving the first picker 30 along the horizontal guide 32 to pick up a punch from the punch storage unit 70 and mount it on the upper table 22 and
at the same time moving the second picker 50 along the horizontal guide 52 to pick up a die from the die storage unit 90 and mount it on the lower table 18.
[0047] In one embodiment (fig. 2) one or each picker 30, 50 is a carriage, slidable on the respective horizontal guide, which is equipped with a head 24, 54 equipped with a gripping member 26, 56, e.g. a pin.
[0048] The gripping member 26, 56, which is preferably horizontally retractable, is configured to engage a corresponding through cavity in a punch or die.
[0049] The gripping member 26 of the picker 30 faces the horizontal guide 52, the gripping member 56 of the picker 50 faces the horizontal guide 32.
[0050] To allow a tool to be removed from a table and taken to the storage unit, or vice versa, in one embodiment the head 24, 54 is movable along Z with respect to the rest of the picker 30, 50; and/or said head 24, 54 is movable with respect to the rest of the picker 30, 50 along the Y axis.
[0051] To allow a tool to be removed from a table or brought to the storage unit, or vice versa, in one embodiment the horizontal guide 32 and the horizontal guide 52 are offset along Y, that is, they lie on vertical planes that are parallel to each other, different and staggered; and/or the horizontal guide 32 and the horizontal guide 52 are staggered along Z, that is, they lie on horizontal planes that are parallel to each other, different and offset.
[0052] In one embodiment, the punch storage unit 70 and the die storage unit 90 coincide, that is, there is only one storage unit from which the pickers 30, 50 pick up the respective tools.
[0053] To speed up setup, in one embodiment the punch storage unit 70 and the die storage unit 90 are distinct and separate components of the press brake (as illustrated in the figures).
[0054] In one embodiment, the die storage unit 90 is adapted to hold only a plurality of dies, and the picker 30 is configured to pick dies only from the die storage unit 90 and place them on the lower table 18.
[0055] In one embodiment, the punch storage unit 70 is adapted to hold only a plurality of punches, and the picker 50 is configured to pick punches only from the punch storage unit 70 and place them on the upper table 22.
[0056] In one embodiment, the die storage unit 90 and the punch storage unit 70 are integrated into the fixed frame of the press 10, for compactness.
[0057] In one embodiment, the die storage unit 90 and the punch storage unit 70 are arranged along X next to each other, and preferably the die storage unit 90 is adjacent to the lower table 18. This facilitates the movement of the pickers and/or their trajectories.
[0058] In one embodiment (fig. 3) the die storage unit 90 comprises a plurality of linear supports 92 for storing a row of aligned dies.
[0059] The linear supports 92 are arranged in a row along Y and are on a plane lying at a lower level than the horizontal guide 52.
[0060] A lifting mechanism 94 mounted in the die storage unit 90 is adapted to pick up and lift along Z a linear support 92 to select a row of dies from the others and position it in front of the picker 50.
[0061] In one embodiment (fig. 4) the punch storage unit 70 comprises a portal 72 and a plurality of punch racks 74 mounted movable and in a horizontal row in the portal 72. Each rack 74 comprises horizontal rows of aligned punches which are arranged staggered along Z on the same vertical plane.
[0062] A lifting mechanism 76 mounted in the punch storage unit 70 is adapted to pick up and lift along Z a rack 74 to select a row of punches from the others and position it in front of the picker 30.
[0063] In one embodiment the punch storage unit 70 comprises
a containment structure 78 for the racks 74 and
a bridge structure 80 extending along Z from the containment structure 78.
[0064] The bridge structure 80 comprises two vertical guides 82 in which the opposite ends of the rack 74 lifted by the lifting mechanism 76 are slidable.
[0065] The containment structure 78 comprises means for translating the plurality of racks 74 along Y with respect to the bridge structure 80, and the bridge structure 80 comprises means for translating one rack 74 of the plurality along Z, so as to isolate a rack 74 for the picker.
[0066] A rack 74 has a variable mass since it can be full of tools or empty (e.g. it varies from 200 to 400 kg). By placing said means for translating the plurality of racks 74 in the containment structure 78, such means are in a lowered position with respect to the portal 72 and do not induce vibrations or deformations on the raised rack. This ensures a more precise grip of the punch by the picker. 30.
[0067] The means for moving and/or lifting may be any known means, e.g. an assembly of drives, guides, or electric motors.
[0068] Operation:
From the above it is understood that to equip the press brake 10:
the picker 30 picks up a punch from a raised rack 74 and then, by moving it on the horizontal guide 32, mounts it on the lower table 18, while
the picker 50 picks up a die from a raised linear support 92 and then, by translating on the horizontal guide 52, mounts it on the upper table 22. These movements occur simultaneously and independently.
- a fixed frame;
- a lower bending table which is fixed to the frame and adapted to receive one or more dies;
- an upper bending table which is
adapted to receive one or more bending punches and
movable relative to the frame towards the lower table to press the workpiece between a die and a punch;
- a first horizontal guide mounted on the frame in front of said tables;
- a second horizontal guide mounted on the frame behind said tables;
- a first movable picker
coupled to the first horizontal guide for moving horizontally from a punch storage unit towards the upper table and
configured to pick up a punch from the punch storage unit and mount it on the upper table, or vice versa;
- a second movable picker
coupled to the second horizontal guide for moving horizontally from a die storage unit to the lower table and
configured to pick up a die from the die storage unit and mount it on the lower table, or vice versa.
move the first picker along the first horizontal guide to pick up a punch from the punch storage unit and mount it on the upper table and
simultaneously move the second picker along the second horizontal guide to pick up a die from the die storage unit and mount it on the lower table.