LUCRĂRI ŞTIINŢIFICE Vol. 54 NR. 2 SERIA HORTICULTURĂ

The laboratory test rig has the following features:
the carriage towing electric motor: 5.5 kW and 1000 rev/min;
the carriage travel: 7 m;
the carriage towing cable: D8 6x19 Seale IWR ISO 2408 (8 mm diameter,
with 6 strands, each having 19 threads);
overall dimensions of the soil channel: 0.8x0.8x10 m (width x height x length);
overall dimensions of the test rig: 2035 x 10865 x 1764 mm;
gear ration of the towing mechanism: 24.31;
RESULTS AND DISCUSSIONS
The tests were performed for two values of the soil penetration resistance:
0.2 MPa and 0.4 MPa (Neculăiasa, 1971; Şandru et al., 1983; Nedeff et al., 1997). An
electronic penetrometer (Penetrologger, Eijelkamp Holland) was used in order to
evaluate the soil penetration resistance.
In the first stage of the tests the working parameters of the test rig were
evaluated. As a result, the following parameters were obtained:
working depth: 0 – 300 mm;
the setting angle of the tillage tool: 25 0 from the average position;
maximum vertical load on the compacting roller: 500 daN;
carriage maximum towing force (at 0.55 m/s): 800 daN;
carriage maximum towing force (at 1.55 m/s): 280 daN;
cable breakdown point: 40.83 kN.
It was concluded that there were no significant differences between the
design parameters and the achieved ones.
The second stage of the experiments aimed to evaluate the working
parameters when a plough body was used as a tillage tool; the effects of the
working depth, soil penetration resistance and working speed over the towing
force and specific power consumption were evaluated. The results are presented
in table 1.
It must be emphasized that the test rig reproduces, in laboratory conditions,
the working process of a mould board plow body. The working width of the plow
body was 200 mm; only the plow body was mounted on the rig carriage.
The experimental results showed that the towing force and the specific
power consumption increased when the working speed increased.
In the meantime an increased soil penetration resistance led to a significant
increase of both the towing force and the specific power consumption (Roş, 1978;
Roş, 1984).
When considering the third working parameter (the working depth) it was
concluded that its increase led to a significant increase of the towing force
(Drăgan, 1969; Scripnic et Babiciu, 1979).
Regarding the specific power consumption it was concluded that increasing
the working depth from 100 to 150 mm led to the decrease of the specific power
consumption; the increase of the working depth from 150 to 200 mm led to the
increase of the specific power consumption. These apparent inconsistancies may
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