buletinul institutului politehnic din iaşi - Universitatea Tehnică ...

258 Iona Ţenu et al.
parameters: working depth of the tillage equipment active parts: 0...300 mm; the
setting angle of the tillage tool: -25 0 ...+25 0 (it is possible to adjust the active
part soil penetration angle with 25 degrees more or less than average angle); the
carriage speed (when towed by the cable by the 5.5 kw electric motor): 0.5…
1.55 m/s; the tyre wheel and compaction roller maximum vertical load: 500
daN; the maximum towing force (of the carriage) at the carriage speed of 0.55
m/s: 800 daN; the maximum towing force (of the carriage) at a carriage speed
of 1.55 m/s: 280 daN; the minimum breaking strength of the towing cable:
40.83 kN. It was concluded that there were no significant differences between
the design parameters and the achieved ones.
In the second stage, the laboratory rig was tested in order to evaluate the
moldboard plough body-ground interaction and tyre wheel- ground interaction
(Fig.2).
3.1. Tests under Laboratory Conditions Regvarding the Active Part-soil
Interaction
A plough body with the working width of 200 mm, mounted on the rig
carriage, was tested. In this case, the effects of the working depth, soil
penetration resistance and working speed of the plough body over the towing
force and specific power consumption were evaluated. The results of the tests
are
presented in Table 1.
The results show that the increase of plough body travelling speed leads
to a increase of the towing resistance force. At the same time, the increasing
speed of the plough body has the effect of a pronounced increase of the specific
power consumption. It may also be noted that an increased soil penetration
resistance leads to a significant increase of the towing resistance force. In the
meantime, an increased soil penetration resistance leads to a significant increase
of the specific power consumption.
It was also found that as the body plough working depth increases, there
is a notable increase of the towing resistance force.
In the meantime, the increase of the plough body working depth causes a
slight and uneven variation of the specific power consumption: increasing the
working depth from 100 mm to 150 mm leads to a slight decrease of the
specific power consumption; when further increasing the working depth from
150 mm to 200 mm, an increase of the specific power consumption was
recorded. These variations of the specific consumption of power may be thus
explained: for low working depths (bellow 15 cm), the slice of soil displaced
does not form a furrow (there is no slice roll-over), so the specific power
consumption is low; for working depths above 15 cm the conditions for the
furrow rollover are becoming better (in this situation, the torsion and inversion
of the furrow are achieved and the specific power consumption increases), so
that the specific energy consumption is getting higher.