Patent attributes
The invention relates to a drive device (1) for a bending press, in particular a folding press (2), comprising a press frame (3), a press table (9) and a press beam (11) that can be adjusted relative to the press table (9) via a hydraulic system (18) comprising a hydraulic pump (47), controlled drive motor (45), switch and control means and pressure lines and at least one pressure cylinder (12) which can be supplied with at least one pressure medium. The hydraulic system (18) forms a closed system together with a ring line (44) comprising the hydraulic pump (47), control valves (39, 41, 58, 84, 86, 87, 88, 89) and a pressure store (57). The ring line comprises a first line section (51) between a pressure chamber (23) of the pressure cylinder (12) and the hydraulic pump (47) and a second line section (53) between an additional pressure chamber (22) of the pressure cylinder (12) and the hydraulic pump (47). The pressure store (57) can optionally be in fluid connection via at least one of the control valves (58, 84, 86) with the first line section (51) or the second line section (53) to take up or release a storage volume of the pressure medium.
