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Idiomas disponibles
Idiomas disponibles
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Bosch Rexroth AG
Function, section: Type Z4WEH
3.2
8
2
9
Valves of type Z4WEH are directional spool valves with elec-
trohydraulic actuation. They control the start and stop of a
flow.
These directional valves basically consist of the main valve
with housing (1), main control spool (2), one or two return
springs (3.1 and 3.2), and pilot valve (4).
Main control spool (2) in the main valve is held by the springs
in the zero or initial position. In the initial position, the two
spring chambers (6) and (8) are connected pressureless to
tank via pilot valve (4). The pilot valve is supplied with pilot
oil via pilot channel (7). The pilot oil supply can be provided
internally or externally (externally via port X in the sandwich
plate, see page 10).
When the pilot valve is operated, e.g. solenoid "a", pilot spool
(5) is pushed to the left, and consequently spring chamber (8)
is pressurized to pilot pressure. Spring chamber (6) remains
pressureless.
The pilot pressure acts on the left side of main control spool
(2) and pushes it against spring (3.1). As a result of this, the
connections on the component side and on the plate side are
opened according to the relevant symbols.
Hydraulics
A
1
A
2
"b"
B
4
P
2
B
1
B
2
TB
2
"a"
A
5
When the solenoid is de-energized, pilot spool (5) returns to
the initial position. Pressure chamber (8) is unloaded to the
tank.
The pilot oil is drained from spring chamber (8) internally via
pilot valve (4) into channel T (Y).
An optional manual override (9) allows pilot spool (5) to be
moved without energization of the solenoid.
Throttle insert
The use of throttle insert (11) is required, if the pilot oil supply
in channel P of the pilot valve is to be limited.
Throttle insert (11) is to be installed in channel P of the pilot
valve.
P
Z4WEH; Z4WH
RE 24753/08.08
3.1
1
6
7
9
① = component side
② = plate side
11
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