BELARUS-1021/1021.3
Operating manual
55
4.9 Hydraulic linkage system
General information
The hydraulic linkage system is equipped
with a hydraulic lift and provides operation of
the rear hitch linkage in the following modes:
- rising the hitch and its lowering by
gravity;
- position control (automatically holding
the hitch in a set position relative to the
tractor);
- draft control (tiling depth control
depending on soil resistance);
- mixed control (tiling depth control by soil
resistance soil with limiting the maximum
depth by position control).
The position provides accurate and sensitive
control of the attached implement position above
the ground, such as spraying machine, land
leveler, etc. The position control can be used with
tillage implements on even fields. Use of the
position control on fields with uneven surfaces is
limited because of unavoidable vertical
displacements of the implement while driving the
tractor on field unevennesses.
Draft control is the most appropriate mode for
use with mounted or semi-mounted implements,
the working bodies of which are buried in the
soil. The system is sensitive to changes in
tractive force (due to changes in the soil
resistance or the tillage depth) through the central
rod of the linkage mechanism. The hydraulic
system responds to such changes by raising or
lowering the implement to support the given
tractive force at a constant level. The system
reacts to the force of compression and extension
in the central rod, thus being a dual action
system.
Mixed control.
If, due to uneven density of the soil draft
control does not let reach a constant tillage
depth, increase in depth over a set value
should be limited with position control.
Operation of a tractor equipped with a
HLL with a hydraulic lift
A HLL with a hydraulic lift is controlled
by two handles located in the cab on the right
control panel:
- the draft control handle (2);
- the position control handle (3).
Position control
1. Shift the draft control handle (2) to its
full forward position along the course of the
tractor.
2. With the postural control handle (3), set
the required implement height above the
ground.
The figure “0” on the control panel
corresponds to the RHL transport position, and
the number “10” to the minimum implement
height above the ground. If you need to limit the
maximum lifting height (for example, because
of possibility of rear PTO parts failure), use the
handle (3) to set the maximum lifting height and
move the adjustable stop (1) to it.
Draft control
Use this control method when working
with mounted implements (plows,
cultivators).
1. Shift the draft control handle (2) to its
leftmost position along the course of the
tractor (figure “10” on the panel).
2. Using the position control handle (3), link
the instrument to the RHL.
3. Upon entry into the furrow, shift the
lever (3) to its forward position and use the
handle (2) to adjust the desired tillage depth.
4. When exiting and subsequently entering
the furrow (while plowing), use only the
positional control lever (3), do not shift the draft
control handle (2).
5. If, due to uneven density of the soil a
constant tillage depth cannot be achieved, limit
the maximum depth with the draft control
handle (3)(mixed control mode), memorizing
the respective figure on the control panel.
Mixed control
The degree of mixing signals from two
sensors (draft and position) is determined by
the handles (2) and (3).
