R901358691 Bosch Rexroth Proportional pressure relief valve

The pilot-operated proportional pressure relief valves of type (Z)DBE are actuated by a proportional solenoid. The valves are used for system pressure limitation. Dependent on the electric command value, these valves can be used to steplessly set the system pressure to be limited. These valves basically consist of a pilot control stage and a main stage. The pilot control component consists of a proportional solenoid (1), the poppet (2), and the valve seat (3). The main stage consists of the housing (4) and the main spool insert assembly (5). The proportional solenoid converts the electric current proportionally into mechanical force. An increase of the current results in a correspondingly higher solenoid force. The system pressure is set in a command value-dependent form via the proportional solenoid (1). The pressure in channel P applied by the system acts on the right side of the main spool insert assembly (5). Simultaneously, the system pressure acts via the control line (7) which is equipped with the nozzle (6) on the spring-loaded side of the spool. Via the valve seat in the pilot line (3), the pressure at the poppet (2) in the spring chamber acts against the force of the proportional solenoid (1). When the pressure has reached the pre-set value, the poppet (3) is lifted off the seat. The pilot oil can now (depending on the version) drain externally via port A (Y) or internally into the tank, which results in a limitation of the pressure on the spring-loaded side of the main spool (5). If the system pressure continues to rise slightly, the higher pressure on the right hand side of the spool will push the spool to the left into the control position P to T. At a minimum control current (corresponds to a command value of zero), the minimum set pressure will be set. Notice! The tank lines should be prevented from running empty. With corresponding installation conditions, a preload valve (preload pressure approx. 1 bar) must be installed. Type DBE The pilot-operated proportional pressure relief valves of type (Z)DBEE are actuated by a proportional solenoid. The valves are used for system pressure limitation. Dependent on the electric command value, these valves can be used to steplessly set the system pressure to be limited. These valves basically consist of a pilot control stage and a main stage. The pilot control component consists of a proportional solenoid (1), the poppet (2), and the valve seat (3). On the proportional solenoid, there is moreover a housing (10) with the control electronics. Supply and command value voltage are applied at the connector (11). At the factory, the command value pressure characteristic curve is adjusted with little manufacturing tolerance. The main stage consists of the housing (4) and the main spool insert assembly (5). The proportional solenoid converts the electric current proportionally into mechanical force. An increase of the current results in a correspondingly higher solenoid force. The system pressure is set in a command value-dependent form via the proportional solenoid (1). The pressure in channel P applied by the system acts on the right side of the main spool insert assembly (5). Simultaneously, the system pressure acts via the control line (7) which is equipped with the nozzle (6) on the spring-loaded side of the spool. Via the valve seat in the pilot line (3), the pressure at the poppet (2) in the spring chamber acts against the force of the proportional solenoid (1). When the pressure has reached the pre-set value, the poppet (3) is lifted off the seat. The pilot oil can now (depending on the version) drain externally via port A (Y) or internally into the tank, which results in a limitation of the pressure on the spring-loaded side of the main spool (5). If the system pressure continues to rise slightly, the higher pressure on the right hand side of the spool will push the spool to the left into the control position P to T. At a minimum control current (corresponds to a command value of zero), the minimum set pressure will be set. Notice! The tank lines should be prevented from running empty. With corresponding installation conditions, a preload valve (preload pressure approx. 1 bar) must be installed. Type DBEE