Patent ID: 9115730
Filing Date: 2015-08-25
Classification: F15B,F16K,Y10T

Abstract:
1. A valve device, comprising: a valve housing having a piston bore, a first load connection, a second load connection, a pressure connection and first and second tank connections therein; first and second electromagnets coupled at opposite axial ends of said valve housing; a valve piston axially movable in said piston bore from a centered middle rest position to a first position connecting said first load connection to said pressure connection and said second load connection to said second tank connection in a first direction and to a second position connecting said second load connection to said pressure connection and said first load connection to said first tank connection in a second direction opposite to said first direction; a pilot control unit having a first pilot chamber pressurizing a first piston back side of said valve piston and having a second pilot chamber pressurizing a second piston back side of said valve piston, said pilot control unit being a spool valve, said first and second pilot chambers having first and second fluid-conducting connections connectable to said first and second tank connections, respectively, said first and second fluid-conducting connections being narrow longitudinal channels from the respective pilot chamber with first and second radial branch ducts, respectively, that are short in length: first and second pilot pistons coupled to and clearing and blocking said first and second fluid-conducting connections between said first and second pilot chambers and said first and second tank connections, respectively; first and second ring channels on outer peripheral surfaces of said first and second pilot pistons controlling said first and second fluid-conducting connections between said first and second pilot chambers and said first and second tank connections, respectively, said first and second radial branch ducts leading to said first and second ring channels, respectively; and third and fourth branch ducts and third and fourth longitudinal channels being opposite said first and second branch ducts in said valve housing leading to said first and second tank connections and being downstream of said first and second pilot chambers and said first and second fluid-conducting connections, respectively.