Pvbz-Hs/Hd, Hitch Control Valves; General Introduction; Pvbz-Hs Basic Module (Hitch Single-Acting) - Danfoss PVG 32 Technical Information

Technical Information

PVBZ-HS/HD, hitch control valves

General introduction

PVBZ-HS basic module (hitch single-acting)

PVG 32 AG Modules
Two types of hitch valves are available for hitch or similar applications. The two valve options offered are
the PVBZ-HS, single acting and the PVBZ-HD, double acting.
The PVBZ-HS matches the market standard whereby implements are raised hydraulically and lowered
only by the pull of gravity. The PVBZ-HD has the unique ability to raise and lower either as single- or
double-acting.
The benefits of the PVBZ-HD reflect a departure from old hitch norms - increased comfort when attaching
implements due to the same speed up and down and safer detachment of heavy implements from the
driver's seat.
The full benefit of the possibilities with the PVBZ-HD is easily obtained by use of the PLUS+1® hitch core
application block. The core application block shifts the valve between single- and double-acting hitch
according to the most suitable operation.
The operator will not have to select the operation but will notice the benefits during normal operation of
the hitch. Work-modes are single-acting as it is standard today, but manual operation up and down are
double-acting to increase comfort, functionality and safety.
For further info and more details please see the Danfoss Hitch control System description, see
reference.
Single acting PVBZ-HS slice for standard hitch application.
It has its own tank port to direct the return flow directly into the tank with a minimum of back pressure.
This prevents tank-line pressure influence, especially when lowering the un-loaded (empty) hitch under
cold conditions (high oil viscosity).
Similar to the auxiliary slice, the single acting PVBZ-HS slice is a pressure-compensated valve slice with
one P/O check valve on B-port only. The same technology as in the PVBZ module is used.
Besides the flow paths, the spool is directing the pilot pressure to the pilot valve for P/O check valve
pressure release as well as to the shuttle pin in order to force the P/O popped to open under low load
conditions. This ensures a fully open flow path in lower mode.
The B-port is normally equipped with a PVLP shock valve.
PVBZ-HS incorporates a compensator with bleed-off to prevent pressure building up between the pump
gallery and the work ports.
A special 3/3 spool with optimized flow characteristics, both in meter-out as well as in meter-in direction,
has to be controlled by a high performance actuator.
Features:
•
Low leakage work port
•
Separated tank port
•
Integrated PVLP shock/anti cavitation valves
•
Can be mixed with PVB/ PVBZ with T0 gallery
•
Compensator with bleed off
•
Rear-Hitch on tractors
•
Header control on combines and harvesters
11051935 • Rev AE • Feb 2014
Literature
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