TIC Liner 3000 with Communicator Individual functions Description of function: No volume flow flowing, the solenoid valve is not actuated Due to the two face-end pressure springs, the spool is positioned so that the ports P and the consumer ports are blocked (see diagram). Oil supply is available, but the control unit is not yet actuated The volume flow enters the control unit via channel P. It flows to the spool through the orifice plate of flow controller (767-4). Since the spool prevents continued flow, a pressure is built up which acts on the right-hand face end of flow controller (767-4) and also in the spring space.
Now equal forces act on the flow controller (767-4) and the pressure spring pushes it to its stop position. Example: Solenoid valve (Y162) is actuated The solenoid coil (Y162) actuates the spool to the left against the pressure spring. The connection from the pump (P) to the left-hand consumer port and the connection of the right-hand consumer port to the tank (T) are opened. In this position, the flow controller (767-4) controls the volume flow to 20l/min ± 0.5 l. This happens even when the load pressure of the consumer changes. Control behaviour of the flow controller When volume flow flows through the flow controller (767-4), different pressures result:
- The pump pressure acts upstream of the orifice plate (3a) - The load pressure acts downstream of the orifice plate (3a) Since the pressure downstream of the orifice plate is lower than the pressure upstream of the orifice plate, a pressure difference results. The flow controller keeps this pressure difference constant even when the load pressure of the consumer (in the spring space) changes. At a constant pressure difference, the volume flow to the consumer is also constant. 12/03 Med-h-Kap2 2-7