Hydraulic valve device with multiple working sections with pump control system

Abstract

Modular directional valve with two or more crossing elements (E 1 . . . En) fed by a variable displacement (PA), negative control or load sensing pump. A pressure regulator ( 5 ) is placed in the entry side and only on the bypass line and upstream of the first element (E 1 . . . En). In the single drive, it makes the flow rate to the utility independent of the load and allows setting a maximum flow rate at the end of the stroke; in multiple drives, it ensures that the sum of the required flow rates is independent of the loads.

1 . A modular directional valve device, fitted with one or more elements or sections (E 1 , E 2 , . . . En) and for controlling a variable displacement pump (PA); said valve device being arranged for connection to the pump (PA) through at least one delivery line (P 1 ) and at least one load line, a fitting for the connection of the tank to the low pressure line (T) into which the return flow rates of utilities and valves flow, a choke arranged on a crossing line or bypass (LC) and downstream of the last element (En); a line (N) for connection, direct or indirect, to the control signal line of the pump (PA); said line (N) adapted to draw the control on the bypass line (LC) between the last element (En) and the choke; wherein a pressure regulator is provided on just the bypass line (LC) and upstream of the first element (E 1 ); the regulator is configured so as to impose a constant pressure drop along just the bypass line (LC) and through the elements (E 1 , En). 
     
     
         2 . The valve device according to  claim 1 , wherein the bypass line (LC) is connectable to the tank (T) through a fitting (C), said fitting (C) independent of the fitting into which the return flow rates of utilities and valves flow. 
     
     
         3 . The valve device according to  claim 1 , wherein the pump (PA) is a variable displacement pump with negative control system. 
     
     
         4 . The valve device according to  claim 1 , wherein the pump (PA) is a variable displacement pump of the load sensing type. 
     
     
         5 . The valve device according to  claim 1 , comprising a choke of a proportional opening drawer along the load line. 
     
     
         6 . The valve device according to  claim 1 , comprising a choke of a proportional opening drawer along the line (P 1 ) before the junction that divides the bypass line (LC) and the load line. 
     
     
         7 . The valve device according to  claim 1 , wherein said control signal (N) is configured to open, in an inversely proportional manner, the choke of said drawer; a signal (LS) from the load line downstream of said choke subsequently arrives to the pump (PA). 
     
     
         8 . The valve device according to  claim 2 , comprising a choke of a proportional opening drawer along the load line. 
     
     
         9 . The valve device according to  claim 3 , comprising a choke of a proportional opening drawer along the load line. 
     
     
         10 . The valve device according to  claim 4 , comprising a choke of a proportional opening drawer along the load line. 
     
     
         11 . The valve device according to  claim 2 , comprising a choke of a proportional opening drawer along the line (P 1 ) before the junction that divides the bypass line (LC) and the load line. 
     
     
         12 . The valve device according to  claim 3 , comprising a choke of a proportional opening drawer along the line (P 1 ) before the junction that divides the bypass line (LC) and the load line. 
     
     
         13 . The valve device according to  claim 4 , comprising a choke of a proportional opening drawer along the line (P 1 ) before the junction that divides the bypass line (LC) and the load line. 
     
     
         14 . The valve device according to  claim 2 , wherein said control signal (N) is configured to open, in an inversely proportional manner, the choke of said drawer; a signal (LS) from the load line downstream of said choke subsequently arrives to the pump (PA). 
     
     
         15 . The valve device according to  claim 3 , wherein said control signal (N) is configured to open, in an inversely proportional manner, the choke of said drawer; a signal (LS) from the load line downstream of said choke subsequently arrives to the pump (PA). 
     
     
         16 . The valve device according to  claim 4 , wherein said control signal (N) is configured to open, in an inversely proportional manner, the choke of said drawer; a signal (LS) from the load line downstream of said choke subsequently arrives to the pump (PA).