Operating_Instructions_RPE3-062x/xS3_14087_1en_05/2022
Page 4
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Glossary of technical terms used
›
A hydraulic mechanism
is one in which energy is transmitted via the compressive energy of the working fluid.
›
The volumetric flow rate Q
s the amount of liquid in volume units that flows through a given flow cross-section per unit time
(SI unit is m
3
s
-1
, in practice the unit
l/min
is used)
›
The control solenoid
is designed to reposition the valve spool that interconnects or closes the channels in the body. The solenoid consists of
an excitation coil which, by passing an electric current through the winding, generates a magnetic field which exerts a force on the armature of
the mechanical control system.
›
The valve connection pattern
describes the relative position of the channel orifices and the holes for the connection bolts at the base
of the valve body, as defined by ISO 4401.
›
Directional control valves
are spool valves that change the connection of the channels in the body by movement of the spool. They are
used in hydraulic circuits to change the movement direction of a piston in a cylinder or the direction of rotation of the output shaft of a
rotary hydraulic motor, or to dam the flow of fluid and stop appliances.
›
Spool position sensor
is a non-contact inductive sensor that responds to the presence of a ferromagnetic core that is mechanically fixed
to the spool.
›
Valve size
(DN) indicates the flow rate of the valve, which corresponds to the flow rate of a straight pipe of the specified inside diameter
(DN). For example, valve size of DN 06 means that a pipe with an internal diameter of d = 6 mm should be used for its connection.
›
Directional control valve spool
is the key control element moving in the valve body chamber. The spool closes/opens the individual channels.
›
Pressure
is the force acting per area unit (SI unit
Pascal
(1 Pa = Nm
-2
), in practice the unit used is
bar
(1bar = 0,1MPa)
›
Performance
in hydraulics is calculated as the product of the pressure and the volumetric flow rate. The performance limit curves
indicate the limit combinations of pressure and volume flow at which reliable valve operation is still ensured.
›
4/2
is the abbreviated designation of the valve description. Four means that it is a four-way valve, i.e. it has four ports (P-pressure,
T-return, leading to the tank, A and B leading to the appliance). Two means that it is a two-position valve, where the spool has only two
positions. The basic position in which it is held by springs and the working position, in which it is moved by the force of the electromagnet.
1. Use of product
The RPE3-06x/xS3 valve
is a hydraulic four-way two-position spool valve with body, directly solenoid operated, designed for connection to a plate
with connection pattern DN 06 according to ISO 4401. The product is designed to control the movement direction of the appliance output compo-
nent or to stop it.
Valve with certified functional safety SIL 3, respectively PL d,
in accordance with the series of standards ČSN EN 61508 and ČSN EN ISO 13849,
is designed for use in systems with increased requirements for reliability and safety, e.g. control hydraulic circuits of presses, plastic injection moulding
machines, forming machines, construction machines, etc.
A prerequisite for using the safety function of the valve
is the correct connection to the hydraulic circuit and its integration into the machine
control system. The basic rule is that the spool is in the safety position when the solenoid is switched off. This condition corresponds to a malfunction
of the control system or a failure of the electrical power supply to the machine.
Examples of safe connection
Example of valve connection with sensor, providing functional safety Pl. d
Example of redundant connection of two valves to achieve functional safety Pl. e
machine
control system
machine
control system
spool position
signal
spool position
signal
spool position
signal
directional control valve
directional control valve
supply voltage of solenoid
supply voltage of solenoid (directional control valve)
supply voltage of solenoid (directional valve, poppet type, blocking)
controlled equipment (cylinder)
controlled equipment (cylinder)
Suitable redundant connection
of another, for example
blocking poppet, valve, can achieve an increase in functional safety.
