Valve device

摘要

A valve device includes a housing (2) and a valve piston (4) axially displaceable in a piston bore (3) of housing (2). First and second load connections (A, B) can alternately be connected to a pressure connection (P) and to tank connections (T1, T2) by moving the piston from an idle position by first and second solenoids (5, 6). First and second pilot control chambers (7, 9) pressurize first and second piston back sides (8, 10) of the valve piston (4). The pressure in the pilot control chambers (7, 9) is controlled by first and second pilot control pistons (12, 13) movable by the solenoids (5, 7). The pilot control chambers (7, 9) are connected via a connection (11) to the pressure connection (P). The pilot control pistons (12, 13) open or close connections (14) between the pilot control chambers (7, 9) and the tank connections (T1, T2).

主权项

1. A valve device, comprising:
a valve housing having a piston bore therein, first and second load connections, a pressure connection and first and second tank connections; a valve piston mounted to move axially in said piston bore out of a middle rest position to connect said first load connection to said pressure connection and said second load connection to said first tank connection in a first direction and to connect said second load connection to said pressure connection and said first load connection to said second tank connection in a second direction opposite the first direction; first and second electromagnets coupled to said valve housing and acting on said valve piston to move said valve piston axially in said piston bore; a first pilot chamber in said valve housing pressurizing a first back side of said valve piston; a second pilot chamber in said valve housing pressurizing a second back side of said valve piston, said first and second pilot chambers being connected to said pressure connection via a fluid-conducting connection; and first and second pilot pistons controlling pressure in said first and second pilot chambers, respectively, and being movable by said first and second electromagnets, respectively, each said pilot piston clearing or blocking a respective opening of a respective drain line in said valve piston respectively connecting the respective pilot chamber to the respective tank connection to control flow of pressure media from said pilot chambers to said tank connections.