High performance bending machine with reduced energy dispersion

Abstract

A bending machine comprises a bending unit moved by hydraulic actuators controlled by a variable displacement hydraulic pump provided with an electronic closed-loop flow rate, pressure and power control system including an electrically controlled proportional valve. The valve includes a valve spool for the control of the swivel angle of the pump and a proportional solenoid for moving the valve spool to a position corresponding to a desired swivel angle of the pump. The control system includes an inductive position transducer, a pump swivel angle transducer, a pump pressure transducer and a programmed electronic control unit which receives position, swivel angle and pressure signals from said transducers and predefined pressure, power and flow rate commands and supplies a control signal to said proportional solenoid.

1 . Bending machine comprising a bending unit which is moved by hydraulic actuators controlled by a hydraulic pump, characterised in that the hydraulic pump is a variable displacement pump provided with an electronic closed-loop flow rate, pressure and power control system including an electrically controlled proportional valve.  
     
     
         2 . Bending machine according to  claim 1 , characterized in that said valve includes a valve spool for the control of the swivel angle of the pump and a proportional solenoid for moving the valve spool to a position corresponding to a desired swivel angle of the pump.  
     
     
         3 . Bending machine according to  claim 2 , characterized in that said control system includes an inductive position transducer associated with the valve spool for detecting the position thereof, a swivel angle transducer associated with the pump for detecting the swivel angle thereof, a pressure transducer arranged on the pump delivery for detecting thereof and a programmed electronic control unit which receives position, swivel angle and pressure signals from said transducers and predefined pressure, power and flow rate commands and supplies a control signal to said proportional solenoid.  
     
     
         4 . Bending machine according to  claim 1 , characterized in that the power delivered by the pump is adjustable by acting on the power command.