FLUID POWER
iVT International Off-Highway 2020 69
but it can be a costly solution in terms of
operating costs. e downside is that the
LS signal is always boosted regardless of the
ow demands from the auxiliary hydraulics.
is consumes additional fuel and heats the
uid unnecessarily.
New approach
To address the problems of poor performance
due to low margin and poor e ciency from the
traditional boost valve, HydraForce engineers
have developed a new, patent-pending, Dynamic
Load Sense Boost Valve. e LSB08-30 is a threeported
dynamic pressure boost valve with an
adjustable threshold. It has the unique ability to
dynamically boost the load-sensing signal
according to the desired margin pressure, and the
ow demand from the system. is is a
completely mechanical solution that requires no
expensive and complicated sensors, electronics,
controllers or programming. It provides more
ow to the auxiliary hydraulics in times of high
demand, but when demand is low saves energy by
dynamically reducing the boost value to zero.
is means fuel savings at the tractor and
increased performance from towed implements.
How it works
e LSB08-30 allows agricultural manufacturers
to set a minimum margin pressure or threshold
of operation for the load-sensing boost feature.
When ow demands are low, margin pressure
will be above the set threshold and no boosting
occurs. When ow demands are at their highest,
pressure in the load sensing line can drop below
the needed margin. is would normally signal
the pump that additional ow is not required.
e pump will not be able to provide the full
available ow to the system, slowing down
operation of the working hydraulics on the
implement. As the pressure in the load-sensing
line drops to the set threshold, or minimum
margin pressure, the LSB08-30 begins boosting
the LS pressure dynamically. is increases the
available margin signaling the pump stroke and
displace more uid.
A dynamic boost
Boosting allows the system to recover high
pressure drops that would normally degrade the
margin pressure available for accurate pump
control. Dynamically boosting saves fuel because
it operates only when a boost is required.
Traditional load sense boosters aren’t able to
operate dynamically and boost the signal
continually. During times of low ow demand,
the additional boost wastes fuel and causes the
pump to work harder when it isn’t needed. iVT
Author: Ben Dupré, senior technical writer, Hydraforce
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LEFT: Conceptual illustration:
High pressure drop caused by
long plumbing runs and other
factors prevents the power
beyond hydraulic system from
delivering at full capacity.
RIGHT: Dynamically boosting
the load sense signal allows
the system to deliver full fl ow
as needed to all parts of the
implement regardless of the
distance from the coupling
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20
15
10
5
5 10 15
BELOW: HydraForce
LSB08-30 Dynamic
Load Sense Boost
Valve
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