Proportional Pressure Reducing Valve 3DREE-7X

The three-way pilot-operated proportional pressure reducing valve 3DREE-7X is an upgraded or modified model of the valve 3DRE series, with higher control accuracy or additional functions (such as integrated electronic control module). Its core function of this proportional valve is to adjust the outlet pressure proportionally through electrical signals, and to achieve pressure control and unloading through the three-way design (P→A, A→T), which is suitable for hydraulic systems that require dynamic and high-precision pressure regulation.

Product parameter of Proportional Pressure Reducing Valve 3DRE-7X

Product parameter of Proportional Pressure Reducing Valve 3DREE-7X

Features:

▶3-way version

▶Operation by means of proportional solenoid with rotatable coil

▶For subplate mounting

▶Porting pattern according to ISO 4401

▶Maximum pressure limitation, optional

▶Valve and control electronics from a single source

▶Integrated electronics(OBE)(type HD-3DRE(M)E):

- Little manufacturing tolerance of the command value pressure characteristic curve

▶External control electronics(type HD-3DRE(M)

▶Linear command value pressure characteristic curve

Application:

Proportional pressure reducing valve 3DREE-7X is mainly used in industrial automation and machine tools, excavators/loaders, hydraulic component test benches, wind power generation pitch systems.

Function and Section of Proportional Pressure Reducing Valve 3DREE-7X

Function, section

The valve types 3DRE(M) and 3DRE(M)E are electrically pilot-operated 3-way pressure reducing valves with pressure limitation of the actuator.

They are used for reduction (P to A) and limitation (A to T) of a system pressure.

Set-up

The valves consist of two main assemblies:

▶Pilot control valve (1) with proportional solenoid (2), optionally with maximum pressure limitation (15)

▶Main valve (3) with main control spool(4)

Function

▶Command value-dependent setting of the pressure to be reduced in port A via the pilot control valve(1).

▶With depressurized port P, the springs (5) and (6) hold the main control spool (4) in its central position.

In this way, a start-up jump at the actuator is prevented.

▶Pilot fluid flows from bore(7) via the flow controller (8), via the control chamber (11) to the throttle gap (9), via line (10) to port Y. This connection is to be led into the tank at zero pressure.

Pressure reduction

▶Build-up of the pilot pressure in the control chamber(11) as a function of the command value.

▶Pressure build-up in the spring chamber (13) via nozzle(12) and movement of the main control spool(4) to the right.

Hydraulic fluid flows from P to A.

▶The actuator pressure in port A is available in the spring chamber(14).

▶Increase in the pressure in port A to the set pressure of the pilot control valve (1) leads to the movement of the main spool (4) to the left. Pressure in port A is almost identical with the set pressure at the pilot control valve (1).

Pressure limitation

▶If the pressure in port A exceeds the set pressure of the pilot control valve (1), the main control spool(4) is moved further to the left.

▶This opens the connection from A to T and limits the pressure pending in port A to the set command value.

Type HD-3DREE and HD-3DREME(with integrated electronics (OBE))

With regard to function and set-up, these valves correspond to types HD-3DRE and HD-3DREM.At the pilot control valve, there is moreover a housing (17) with the control electronics.

Supply and command value voltage are applied to the connector(18).

At the factory, the command value pressure characteristic curve is adjusted with little manufacturing tolerance . For more information, see page 9.