Пропорциональный редукционный клапан, пилотного управления DRE(M) 10, DRE(M) 20

Description Size 10, 25 Component series 6X Max. operating pressure 315 bar Flow, max. 300 l/min Features Valve for reducing a system pressure Operation by means of a proportional solenoid Proportional solenoid with rotatable and detachable coil For subplate mounting: porting pattern according to ISO 5781 Third way A to Y (Ø 7.5 mm) Linearized pressure/command value characteristic curve Good transient response Optional check valve between A and B Optional maximum pressure limitation Product description Valves of type DRE(M) are pilot-operated pressure reducing valves. They are used for operating pressure reduction. These valves basically consist of a pilot control valve (1) with proportional solenoid (2), a main valve (3) with main spool insert (4), as well as an optional check valve (5). Type DRE... The pressure in channel A is set in a command value-dependent form via the proportional solenoid (2). In rest position – no pressure in channel B –, the spring (17) holds the main spool (4) in its initial position. The connection from channel B to A is closed. A start-up jump is thereby prevented. The pressure in channel A acts on the surface (7) of the main spool via the bore (6). The pilot oil is taken from channel B and flows through the bore (8) to the constant-current control (9) that keeps the pilot flow constant independent of the pressure drop between channel A and B. From the constant-current control (9), the pilot flow flows in den spring chamber (10), through the bores (11) and (12) via the valve seat (13) into channel Y (14, 15, 16) and from there to the return flow. The pressure required in channel A is preset at the related amplifier. The proportional solenoid moves the valve poppet (20) in the direction of the valve seat (13) and limits the pressure in the spring chamber (10) to the set value. If the pressure in channel A is lower than the preset command value, the higher pressure in the spring chamber (10) moves the main spool to the right. The connection from B to A is opened. If the set pressure in A is reached, the forces at the main spool are balanced – the main spool is in control position. Pressure in channel A • Spool face (7) = pressure in spring chamber (10) • Spool face – spring force (17) If in a standing hydraulic fluid column (e. g. cylinder piston at stop), the pressure in A is to be reduced, (e. g.) a lower command value is preset at the control electronics and in this way a lower pressure is preselected which is present immediately in the spring chamber (10). The higher pressure in A which acts on the surface (7) of the main spool pushes the main spool to the stop against the plug screw (18). The connection A to B is blocked and A to Y is open. The force of the spring (17) now counteracts the hydraulic force acting on the surface (7) of the main spool. In this main spool position, the hydraulic fluid can flow from channel A via the control edge (19) to Y into the return flow. When the pressure in A has dropped to the p