2-Way Proportional Throttle Valve
This combination unit, can be used as a throttle (orifice) or in conjunction with a pressure compensator for controlling high flows The applications include, for example. control systems for presses and plastic processing machines Despite the high flow rates, the unit has a fast response time.
The 2-way throttle valve is an orifice with its opening stroke determined by an electrical signal The throttle valve is supplied as a unit ready for installation with installation dimensions to DIN 24 342 The bushing (2) is screwed into the cover (t) together with the orifice spool (3) as well as the positional transducer (4) and the pilot control (5). including proportional solenoid (6).
The direction of flow is from A to B. The pilot oil port X is linked to the port A The pilot oil outlet Y should be routed to the tank at zero pressure.
At zero signal (no current applied to proportional solenoid (6)) the pressure in port A acts via the pilot line X and the control spool (10) in addition to the spring in chamber (8). The orifice spool (3) is held closed If a signal is led to the amplifier card, the command signal (external signal) is compared In the amplifier (7) with the actual signal (feedback of the transducer signal) The proportional solenoid (6) is energized with a current corresponding to the differential value.
The solenoid shifts the spool (10) against the spring (11). As the result of interaction between the throttling points (13) and (14), the pressure in the spring chamber (8) is set such that the spring-loaded orifice spool (3) assumes a position corresponding to the preset signal and therefore determines the flow.
The orifice spool closes automatically (for safety) in the case of power failure or cable breakage The components of the closed loop position control are designed such that the command signal and the stroke of the orifice spool (3) are directly proportional with respect to each other Consequently,for constant pressure differences the orifice, the flow from A to B is only dependent on the stroke of the orifice spool and the window geometry (9)
Direct proportionality between the signal and flow is applicable to the system with linear opening law (FE..C1X/L). The quadratic opening law (version FE..C1X/0) signifies a volumetric flow increasing qua-dratically with the command signal
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