| 摘要 |
An apparatus for the electrohydraulic control of the parallelism of a roller (4) in a bending machine (1;10) for working metal pieces (L), comprises pump means (P1,P2) for supplying with an operating fluid first actuating means (C1) and second actuating means (C2) arranged for moving respectively a first end (11) and a second end (12) of said roller (4); position transducer means (T1,T2) connected operationally to an electronic control unit (U1) and suitable for detecting the positions of said first (11) and second (12) end; first (VP1) and second (VP2) proportional valve means that are operatively controllable by said electronic control unit (U1) to adjust the flow of said operating fluid into said first (C1) and second (C2) actuating means according to of signals of said position transducer means (T1,T2). The pump means comprises a first pump (P1) and a second pump (P2) that are operatively connected together, arranged for supplying in a dedicated manner said first (C1) and second (C2) actuating means respectively by means of a first (5) and a second (6) hydraulic circuit that are independent of one another, said first (VP1) and second (VP2) proportional valve means being located, according to a parallel configuration, along a first (13) and a second (14) conduit connected in a branched manner to a first (8) and second (18) delivery portion of said first (5) and second (6) hydraulic circuit respectively. The first (VP1) and second (VP2) proportional valve means are configured for being able to tap operating fluid from said first (8) and second (18) delivery portion to reduce the volumetric flowrate thereof towards said first (C1) and second (C2) actuating means. A corresponding method is also provided for controlling the parallelism of a roller (4) of a bending machine (1; 10). |
