Bending machine for metal sheets

A bending machine for metal sheets, the bending machine comprising:

• a punching arrangement including an upper crosspiece supporting a plurality of upper bending tools aligned and reciprocally positionable along a longitudinal bending direction so as to form definite compositions of upper bending tools;
• a die arrangement including a lower crosspiece supporting a plurality of lower bending tools aligned and mutually positionable along the longitudinal bending direction so as to form respective compositions of lower bending tools;
• at least one back gauge unit that is movable inside an operating area of said bending machine and arranged to abut and position a workpiece with respect to said die arrangement, wherein said at least one back gauge unit comprises a hooking element arranged to engage at least one lower bending tool in order to move said at least one lower bending tool along the longitudinal bending direction on said lower crosspiece;
• and
• an actuating system,
• wherein said plurality of lower bending tools comprises at least one set of side lower bending tools that can be positioned, when not being used to bend the workpiece, in a respective non-operative configuration at an end portion of said lower crosspiece where a number of said side lower bending tools are positioned outside of the operating area and are unreachable by said back gauge unit,
• wherein said side lower bending tools can be selectively connected to and disconnected from one another in order to form a convoy selectable in number of side lower bending tools,
• wherein at least an innermost side lower bending tool of said side lower bending tools of said convoy positioned in the non-operative configuration is inside the operating area so that said innermost side lower bending tool can be engaged by said hooking element of said back gauge unit and moved by said back gauge unit along the longitudinal bending direction together with said convoy of side lower bending tools,
• wherein each side lower bending tool comprises a connecting assembly to engage or disengage a respective connecting assembly of an adjacent side lower bending tool in order to connect or disconnect adjacent side lower bending tools from one another and form said convoy of side lower bending tools,
• wherein said actuating system acts selectively on said connecting assemblies of said side lower bending tools to mutually engage or disengage said connecting assemblies and allow respective side lower bending tools to be connected or disconnected,
• wherein each of said connecting assemblies comprises a first connecting element and a second connecting element fixed on opposite sides of a respective side lower bending tool, and wherein said first connecting element is movable by said actuating system between a hooking position and a releasing position respectively to engage or disengage said second connecting element of an adjacent side lower bending tool, and
• wherein said actuating system comprises a plurality of actuating cylinders positioned adjacent to said lower crosspiece, and wherein each actuating cylinder is arranged to move said first connecting element of a respective side lower bending tool in order to move said first connecting element between the hooking position and the releasing position.