The present invention relates to a press brake with automatically variable length bending tool.
Press brakes adapted to bend metal sheets by exerting a pressure by means of a specific tool are known in the prior art. The metal sheets to be bent may have folded ends and different lengths. The bending tool must be manually varied to adapt it to the various lengths of the metal sheets.
It is the object of the present invention to provide a press brake with automatically variable length bending tool so as to adapt the tool to the different lengths of the metal sheet.
In accordance with the present invention, said object is achieved by a press brake for metal sheets comprising a tool for bending the metal sheet, said tool comprising a die and pressure means opposite to said die and adapted to pressing the metal sheet against the die to determine the bending of the metal sheet, said pressure means comprising a plurality of first segments aligned along the bending direction of the metal sheet and adapted to press said metal sheet against said die and said press brake comprises control means adapted to change the longitudinal dimension of said pressure means, said control means being adapted to individually drive each first segment for its longitudinal sliding along the bending direction of the metal sheet so that the longitudinal dimension of the pressure means corresponds to the longitudinal dimension of the fold to effectuate on the metal sheet, said pressure means comprising a plurality of second segments, said control means being adapted to individually drive each second segment for inserting it between said first segments so that the second segment is aligned to the first segments along the bending direction of the metal sheet and so that the longitudinal dimension of the pressure means comprising at least one first segment and at least one second segment corresponds to the longitudinal dimension of the fold to effectuate on the metal sheet, characterized in that said control means comprises first means adapted to determine the insertion of at least one second segment between two first segments by means of a movement transversal to the bending direction of the metal sheet, said first means comprise movement means configured to carry out a combination of a rotation movement and a translation movement of said at least one second segment for inserting said at least one second segment between two first segments.
The features and advantages of the present invention will be apparent from the following detailed description of a practical embodiment thereof, shown by way of non-limitative example in the accompanying drawings.
In the drawings:
The pressure means 12 are associated with a device 100 for changing the length thereof, i.e. the longitudinal dimension thereof, so as to make it either slightly smaller than or equal to the longitudinal dimension of the metal sheet to be bent, i.e. so that the longitudinal dimension of the pressure means 12 corresponds to the longitudinal dimension of the fold to be made on the metal sheet 9. Pressure means 12 comprise a plurality of segments 13 sliding along an upper longitudinal guide 25 and shown in greater detail in
Device 100 is adapted to drive the longitudinal sliding of segments 13 along guide 25. Each segment 13 comprises a longitudinal through hole 18 for engaging one of the half guides or longitudinal bars 14′, 14″, arranged one after the other in the bending direction of the metal sheet and longitudinally movable, and an actuator 19, which cooperate for the sliding of segment 13 along guide 25.
The control device 100 comprises a processing unit 200, arranged on the body of press brake 1 or spaced therefrom, set by a user and adapted to control means 15 and actuators 19; each actuator 19 is individually controlled by the processing unit 200 connected to the actuator by means of wires. Unit 200 may control either all the actuators 19 of segments 13 at the same time or only one or some of them adapted to engage one of bars 14′, 14″ for sliding on guide 25. In particular, each actuator 19 comprises a piston which is movable by means of a cylinder (not shown in the figures) and may be inserted into one of the holes 20 on bar 14′, 14″. Once segment 13 has been blocked on bar 14′, 14″, the bar itself may be longitudinally moved so as to longitudinally slide one of or all segments 13 (
Bars 14′, 14″ are preferably interrupted in the longitudinal direction by a central empty space 30. All elements 13 have equal length D and size.
The pressure means 12 comprise another plurality of segments 21; the length of each segment 21 is different from the other segments 21 of the plurality, i.e. segments 21 have different lengths D1, D2 . . . Dn. A single segment 21 or several segments 21 may be inserted between segments 13; in particular, the insertion of one of or more segments 21 occurs in the central space 30 of the plurality of segments 13. Each segment 21 is either shorter or longer than each segment 13. One or more segments 21 are inserted between part or all of segments 13, if the metal sheet to be bent, in particular the part of the metal sheet to be bent, has a length L which is not a whole multiple of the length D of segment 13, i.e. L=n*D+e, where “n” is an integer and “e” is a real number complementary to length L. In such as case, one or more elements 21 should be inserted to cover the missing distance “e”; e.g. for a metal sheet of length L1, L1=n1*D+Dx where “n1” is an integer and “Dx” is the length of a specially made segment 21.
Each segment 21 has a cross section of the lower part equal to the cross section of the lower part of segments 13 and is inserted into space 30 so as to be longitudinally aligned with the other segments 13.
Each segment 21 is connected to movement means 40 which allow it to be inserted into the central space 30 or moved away from the central space 30. The movement means 40, controlled by the unit 200 and better seen in
Movement means 40, movement means 15 and actuators 19 belong to device 100, which is adapted to change the length, i.e. the longitudinal dimension, of the pressure means 12. In particular, device 100 is adapted to change the length of the pressure means 12 in accordance with the length of the metal sheet 9, thus allowing whether inserting one or more segments 21 or not, and providing for moving some segments 13 in the longitudinal direction from the central part 50 where the metal sheet 9 to be bent is arranged.
For example, considering that the pressure means 12 comprise eighteen segments 13 of length D and three segments 21 of different lengths D1, D2 and D3, different combinations are possible according to the length of the metal sheet 9 to be bent, as shown in
For example, if the length of the metal sheet, i.e. the part of metal sheet to be bent, is L1=18*D+D2, the situation shown in
If the length of the metal sheet, i.e. the part of the metal sheet to be bent, is L2=10*D+D2, the situation shown in
If the length of the metal sheet, i.e. the part of the metal sheet to be bent, is L3=3*D+D2, the situation shown in
If the length of the metal sheet, i.e. the part of the metal sheet to be bent, is L4=2*D+D1 the situation shown in
If the length of the metal sheet 9, i.e. the part of the metal sheet to be bent, is L5=n5*D, i.e. the length of the metal sheet is an exact multiple of the length D of segment 13, only the necessary segments 13 will be moved, i.e. six segments if n5=6, towards the central space 30, i.e. three segments carried by bar 14′ and three segments carried by bar 14″, until the segments 13 carried by a bar 14′, 14″ are adjacent to the segments carried by the other bar 14′, 14″ to totally cover the central space 30; said movement is implemented by controlling the actuators 19 of the only six segments 13 for the connection to bars 14′, 14″ and the following longitudinal movement of bars 14′, 14″ towards the central space 30 by means of the movement means 15 controlled by the central unit 200. The side interruptions 51, 52 are again made in the plurality of segments 13.
If the edges of the metal sheet to be bent have a sequence of U-shaped profile folds on the previously bent adjacent sides, as shown in
The metal sheet 9 is then inserted, as usual in the working position, under the bending tool so as to obtain a metal sheet 90 with length L90 and U-folded edges.
The bending tool is released once the U shaped edges have been made (
Segment 21 having length D2 is then moved away from the central space 30 by the movement means 40 controlled by unit 200. Arm 43 thus slides downwards on arm 41 with a downward translation of segment 21 (
Six segments 13 then move towards the central space 30, i.e. three segments carried by bar 14′ and three segments carried by bar 14″, until the length of the pressure means given by the six segments 13 is shorter than the distance between the opposite ends of the folded edges of the metal sheet 90. Said movement is implemented by controlling the actuators 19 of the only six segments 13 for the connection to bars 14′, 14″ and the following longitudinal movement of bars 14′, 14″ towards the central space 30 by means of the movement means 15 controlled by the central unit 200 (
The metal sheet 90 may thus be removed (
Number | Date | Country | Kind |
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MI2010A 000405 | Mar 2010 | IT | national |