Metal sheet bending machine

A bending machine for metal sheets comprising a punch assembly including an upper tool-holding crosspiece that is provided with and supports at least one set of upper bending tools provided with respective supporting pins and aligned and reciprocally positionable on said upper tool-holding crosspiece along a bending direction, said upper tool-holding crosspiece being provided with a guiding groove that is open at the bottom by a first lower opening for receiving said at least one set of upper bending tools and comprises a lateral supporting groove adapted to receive and support said supporting pins and to maintain said at least one set of upper bending tools slidably coupled to said upper tool-holding crosspiece in an assembly configuration thus preventing disengagement of said upper bending tools, wherein:

• said supporting groove comprises a single second lower opening having a definite length along said bending direction such as to allow disengaging/engaging said supporting pins from/with said supporting groove to remove/insert from/into said upper tool-holding crosspiece at the same time all the upper bending tools of said set of upper bending tools;
• said punch assembly comprises a single closing element that has said definite length along said bending direction, is connected to said upper tool-holding crosspiece and is linearly movable between a closed position, wherein said closing element closes said second lower opening of said supporting groove to keep said supporting pins engaged with, and supported by, said supporting groove, and an open position, wherein said closing element is spaced from, and does not close, said second lower opening to disengage said supporting pins.