Misr J. Ag. Eng., 23(3): 509- 531
FARM MACHINERY AND POWER
CONSTRUCTION AND MANUFACTURE A SELFPROPELLED MACHINE SUITS FOR CUTTING SOME
GRAIN CROPS TO MINIMIZE LOSSES AND MAXIMIZE
EFFICIENCY
Moheb M. A. El-Sharabasy
ABSTRACT
In the absence of appropriate mechanization, harvesting of both rice and
wheat crop is a major production problem in Egyptian delta. Acute labor
shortages at harvest time cause delays in clear fields leading to high grain and
straw losses. This work describes the constructions of a new self-propelled
machine for cutting rice and wheat crops. The machine consists of four main
devices names: cutter bar, crop reel, conveyor belt and transmission system.
The new constructed machine was operated in rice and wheat fields at four
kinematic parameters and four grain moisture contents to determine the
proper operating parameters for cutting both rice and wheat crop. Results
indicated that the maximum field capacity and the lowest operating cost of
(0.452, 0.621 fed/h), (37.50, 37.26 L.E/fed) were obtained at low kinematic
parameters of (1.8, 1.45) and low grain moisture content of (21.45, 19.11 %);
maximum both field efficiency and cutting efficiency of (69.17, 82.15 %),
(86.88, 91.41 %) were obtained at high kinematic parameters of (4.67, 3.20)
and low grain moisture content of (21.45, 19.11 %); minimum fuel and energy
consumed of (1.51, 0.47 l/h), (2.97, 1.53 kW.h/fed) were obtained at kinematic
parameters of (2.33, 1.78) and grain moisture content of (22.20, 20.10 %) and
minimum grain losses and criterion cost of (1.03, 0.76 %), (72.18, 64.82
L.E/fed) were obtained at kinematic parameters of (2.33, 1.78) and grain
moisture content of (22.20, 20.10 %) for both rice and wheat crop,
respectively.
INTRODUCTION
H

arvesting and threshing represent the final field operation in the main
crops such as rice, wheat, and clover. It is the point when farmers and
labors receive the payoff from care and rearing of the crop. In many
Egyptian farms, harvesting is still done with traditional tools such as
Lecturer of Agric. Eng. Dept., Fac. of Agric., Zagazig Univ., Egypt.
Misr J. Ag. Eng., July 2006
509
sickles and scythes especially in wheat farms which require more labor days
per feddan. Because of high labor requirements and the concurrent maturity of
many rice and wheat fields, there are often difficulties in sufficient harvest
labor to ensure timely harvest and optimal yields. Also, harvest delay of grain
crops can harm the cattle production.
In Egyptian delta, most owners of small combines deny to work in wheat fields
because of its dry soils which damage combine crawlers. So that, the most
Egyptian farmers obliged to cut wheat crop manually, this consumes more
labor and time which affected to soil preparation for the next crop.
Using a self propelled cutting machine may overcome this problem, which
clear the crop in the time without more labor consumed.
Metwalli et.al (1981), fount that the total harvesting cost using self-propelled
mower was 7.00 L.E/fed for wheat and 8.17 L.E/fed for rice, while the total
cost of manual harvesting using hand sickles was 18.44 L.E/fed for wheat and
22.25 L.E/fed for rice. Therefore, the mower could save about 62 % in the case
of wheat crop and about 63 % in the case of rice crop.
Hadidi (1984), stated that, the height of crop stubbles increasing as stalks
moisture content increased and decreased with increasing of knife velocity. He
added that the percentage of wheat and rice grain losses increasing as the
machine forward speed increased. Increasing cutter bar speed leads to decrease
the percentage of grain losses. Also, increasing forward speed leads to increase
the number of uncut stalks.
Embaby (1985), found that the harvesting cost of wheat crop with tractor
mounted mower (cutter bar 180 cm) and self-propelled mower (cutter bar 127
cm) were 13.91 and 17.05 L.E/fed., respectively.
Devani and Pandey (1985), designed and developed a vertical conveyor belt
windrower for harvesting wheat crop. They concluded that, field capacity
achieved with 1.6 m wide unit was 0.269 ha/h and for 2.09 m wide unit was
0.337 ha/h. The costs of operation with tractor and power tiller models were
low as compared to manual method by 20 to 30 %. The total harvesting losses
were in the range of 4 to 6 % of grain yield when grain moisture content was 7
to 11 %. The labor requirements are reduced to 40-42 man-h/ha, one third of
manual harvesting method.
Misr J. Ag. Eng., July 2006
510
Hanna and Suliman (1986), mentioned that, the rear side mounted
reciprocating mower connected with tractor gave an average hourly production
of 1.35 feddan. The higher of crop residue after cutting process was more or
less around 6 to 7 cm above the ground.
El-Danasory (1987), evaluated the performance of single and double knife
mowers in harvesting and clearing the field off crop residuals through
determining forward speed, field capacity and height of cut when harvesting
wheat, sorghum, and cotton stalks. The average forward speed ranged from 3.4
to 4.6 km/h. The field capacity ranged from 0.88 to 1.27 fed/h. The stubble
height was as low as 4 to 9 cm.
Sahar (1988), reported that, the use of a large scale machine is inappropriate
for the following reasons:It needs high technical experience for operation and maintenance.
High capital requirements.
Low field efficiency in small holdings and losses of straw are high on
irregularly furrowed soils.
The use of small machines is appropriate for small holdings, low capital
requirements and low technical operation and maintenance experience.
Singh et.al. (1988), studied harvesting wheat crop by power reaper. They
found that average field capacity was about 0.4 ha/h with 4 % grain losses.
Labor input in mechanical reaping was about 5 man-h/ha compared to 84 manh/ha in manual harvesting operation.
Murthy (1989), developed a simple tractor-mounted vertical conveyor reaper.
The machine can be used with any 20 hp tractor cuts the crop at 7-8 cm above
the ground and saves the straw. It has field capacity of 5-7 acres/day and can
be adjusted to (60-80) cm above the ground level for transportation.
El-Sahrigi et.al. (1992), developed a front mounted reaper. The design
features included a flat belt mechanism conveying the crop to the side of
machine, improved cutter bar, star wheel assembly to minimize clogging, a
bevel gear drive for power transmission, a robust frame, a header pipe design
that will not dig into the soil and provision to convert the flat belt conveyor
drivers to chain without frame modification.
Mahrous (1995), tested and evaluated a horizontal flat conveyor belt for
improving the efficiency of a rear mounted mower. The mower was operated
Misr J. Ag. Eng., July 2006
511
at wheat crop under forward speeds of 3, 4, 5 and 6 km/h. The average field
capacity, field efficiency, cutting efficiency and cost requirements were 1.18
fed/h, 70 %, 97 % and 6.947 L.E./fed for the developed rear-mounted mower,
respectively.
Metwalli et.al. (1995), found that increasing moisture content of cotton stalks
leads to increasing the cutting efficiency which means decreasing the power
requirements.
Morad (1995), studied the effect of kinematic parameter (Ratio of cutting
rotary speed to tractor forward speed) on fuel and energy requirements. He
found that both fuel and energy requirements decreased as the kinematic
parameter decreased.
El-Sharabasy (1997), compared four different machines (small combine
harvester, power reaper, self propelled mower and rear mounted mower) in
wheat and rice fields. He found the followings: The minimum grain loss of 1.66 % was obtained under small combine
harvester.
 The highest efficiency of 78.04 % was obtained under self propelled
mower.
 The highest field capacity of 1.64 fed/h was obtained under power reaper.
 Harvesting by self propelled mower + threshing with stationary thresher
recorded minimum energy of 25.38, kW.h/fed.
 The minimum total cost of 173.03 L.E/fed and 182.43 L.E/fed obtained
under small combine harvester for both wheat and rice crops.
Habib et.al. (2001), mentioned that increasing plant diameter needs higher
knife velocity for performing the free cutting operation. Whereas, increasing
mass of plant stalks needs low critical speed. They added that critical knife
velocity affected by both height of knife from the ground and the plant overall
length. Also, moisture content of plants materials affecting on the critical knife
velocity throwing by the cutting force, where the cutting force variation with
the moisture content.
Habib et.al. (2002), stated that the parameters affecting cutting process are
related to the cutting tool, machine specifications and plant materials
properties. They added that, the cutting energy consumed in harvesting process
Misr J. Ag. Eng., July 2006
512
is much lower than the energy consumed in crushing process due to the effect
of moisture content.
Badr (2005), compared the performance of three different combines in terms
of harvesting time, grain losses, fuel consumption, energy required and total
cost. He found that the highest field capacity of 3.02 fed/h and the lowest field
efficiency of 70.5 % were obtained at forward speed about 4.0 km/h and grain
moisture content of 22 %. Also, the highest fuel consumption of 18.25 l/fed
and the highest energy required of 50.55 kW.h/fed were obtained at forward
speed about 1.0 km/h and grain moisture content of 22 %.
In this study, a self propelled cutting machine was constructed and
manufactured to cut the main crops in Egypt (rice and wheat), and also
accumulated the cutting materials at the side of the machine by a flat conveyor
belt. This machine was evaluated to find out the proper working parameters
under rice and wheat crops.
MATERIALS AND METHODS
Field experiments were carried out on rice and wheat crops at a private farm in
Damietta governorate. The soil structure was identified as a clay soil. The field
experiments were carried out during the agricultural season 2005/2006. The
total experimental area was about 2 feddans planted with rice (Sakha-101) and
wheat (Sakha-93) crops.
- Specifications of constructed cutting machine:
 Engine
1141-E
Model
Briggs & Stratton
Type
USA
Made
12.5 hp (9.38 kW)
Power
3200 rpm
Rated speed
Benzene
Fuel
 Machine
Model
Stiga Villa
Made
Sweden
Gear box (Fast-Slow)
(5 forward & 1 reverse) speeds
Working width
140 cm
Overall length
280 cm
Misr J. Ag. Eng., July 2006
513
Overall width
Overall height
Overall weight
 Cutting device:
1- Cutter bar (single)
2- Crop reel
3- Conveyor belt
160 cm
120 cm
300 kg
140 cm (length)
125 cm (length) × 50 cm (diameter)
125 cm (length) × 48 cm (width)
1- CONSTRUCTED CUTTING MACHINE
The constructed cutting machine was manufactured and constructed to
overcome the problems which noticed clearly at harvesting grain crops using
the traditional harvesting method which consumed more time and labor and
then more cost requirements.
To overcome these problems, the developed cutting machine was constructed
and manufactured to give the minimum limit of the grain losses, high field
capacity and efficiency and also save total cost requirements. The top view and
side view of the developed cutting machine show in figs (1 and 2).
The modifications of cutting machine were as the followings:1- Cutter bar:
The cutter bar consists of a single action cutter bar, which has 28 knifes
triangular in shape located above fixed one has the same number of guards.
The cutter bar is 140 cm in length takes its reciprocating motion from the
machine engine through transmission system. As shown in fig. (3).
2Conveyor belt:
A flat conveyor belt was fixed on a special frame directly behind the cutter bar
to carry the cutting materials slightly aside the machine. This conveyor belt
consists of rubber belt which has dimensions of 125 cm for length, 48 cm for
width, and 0.2 cm for thickness. Two cylinders which have diameter of 6.0 cm,
length of 50 cm, and distance between each axis of 120 cm were used to keep
the conveyor belt always in horizontal position.
The conveyor belt is powered by means of two pulleys. The first pulley which
has diameter of 6.3 cm was fixed on the power shaft which takes its motion
from the gear box; the second pulley which has diameter of 10 cm was fixed
on the drive cylinder of the conveyor belt. These two pulleys keep constant
relation between drive cylinder rotating speed and finger rotating speed of
Misr J. Ag. Eng., July 2006
514
No.
Part Name
No.of
7
8
Cutter bar
Crop reel
Conveyor belt
O-Belt
Front wheel
Rear wheel
Drive pulley
Reel pulley
1
1
1
1
2
2
1
1
1
2
3
4
5
6
All dimensions in mm
1400
1
2
50
980
400
8
4
3
5
1600
7
6
Fig.(1): The top view of the constructed cutting machine.
Misr J. Ag. Eng., July 2006
515
Misr J. Ag. Eng., July 2006
516
6
850
5
1
1
1
1
2
2
Cutter bar
Crop reel
Conveyor belt
Gear box
Front wheel
Rear wheel
500
3
2
Fig.(2): The side view of the constructed cutting machine.
4
No.of
Part Name
All dimensions in mm
1
2
3
4
5
6
No.
430
300
1
(1:1.58) to give constant relation between conveyor belt speed and machine
forward speed of (1:1.4).
3- Crop reel:
The crop reel was fixed above the cutter bar to deliver and guide the plant
stalks to the cutter bar, holding them upright during cutting operation, also
deliver the cutting plants over the conveyor belt. The reel diameter is 50 cm
while the reel width is 115 cm, and six sides in shape. The crop reel has six
metal bats fixed along the reel. The metal bat length is 115 cm; the width is 1.5
cm, and 0.3 cm in thickness.
60 tines are placed along the reel bats at an angle of 45 to the vertical, which
facilities lifting and feeding the stalks to the cutter bar. The tine length is 10
cm and the distance between two tines on the same bat is 11 cm.
The crop reel is fixed above the cutter bar on a special frame having L-shape to
be able to change the vertical distance between the reel shaft and the cutter bar,
also the horizontal distance between the reel axis and the front end of the cutter
bar. The crop reel is operated by a pulley of 10 cm in diameter and O-belt
which takes its motion from the machine ground wheel using pulley with
diameter of 10 cm.
4- Transmission system:
The power is transmitted from the machine engine to the cutter bar as shown in
fig. (3). - A 3000 rpm at engine pulley which has diameter of 11.2 cm can be
transmitted to gear box pulley having diameter of 15 cm using V-belt between
the two pulleys to be equal 2100 rpm, with reduction ratio of 10:7 or 1.43:1.
- The 2100 rpm at gear box pulley is reduced to 700 rpm in the gear box with
reduction ratio of 3:1. - The rotating speed transported from the gear box to the
power shaft through a universal joint having length of 50 cm.
2- MEASUREMENTS
● Un-cutting losses:
Un-cutting losses were optioned by collecting un-cutting crop by sickle for
each plot area. The total samples were collected and threshed manually, and
then the cleaning grains were weighted. The percentage of un-cutting losses
was calculated by using following equation:Un  cutting losses %  
Misr J. Ag. Eng., July 2006
Un  cutting losses / fed
 100 .......... ....( 1 )
Total yield / fed
517
11
10
9
90
230
8
150
Ø160
110
175
7
383
6
245
Soil surface
All dimensions in mm
5
1
1
1
1
1
1
100
12
10
11
9
8
7
No.off No.
500
3
1
1
1
1
1
1
Gear box
Gear box pulley
Machine engine
Engine shaft
Engine pulley
V-Belt
4
No.off
Part Name
2
Fig.(3): Power transmission from the machine engine to the cutter bar.
12
Ø112
Ø25
250
5
6
4
3
2
Cutter bar
Crank
Power shaft
Conveyor belt pulley
Bearing
Universal joint
Ø63
Part Name
Ø25
1
80
No.
Ø20
Misr J. Ag. Eng., July 2006
518
1
● Operating grain losses:
Operating losses were obtained by locating a frame of square meter on the
ground after cutting the crop by constructed cutting machine, and then the
grain losses in the frame represent pre-cutting and operating losses together.
Then, for indicating the operating losses only, the pre-cutting losses must be
subtracted.
The percentage of operating losses was calculated by using the following
equation:Operating grain losses %  
Operating losses / fed
 100 .......... ....( 2 )
Total yield / fed
● Operating grain losses:
Operating losses were obtained by locating a frame of square meter on the
ground after cutting the crop by constructed cutting machine, and then the
grain losses in the frame represent pre-cutting and operating losses together.
Then, for indicating the operating losses only, the pre-cutting losses must be
subtracted.
The percentage of operating losses was calculated by using the following
equation:Operating grain losses %  
Operating losses / fed
 100 .......... ....( 2 )
Total yield / fed
● Total grain losses:
The percentage of total grain losses was calculated by using the following
equation:Total grain losses = (Pre-cutting+Un-cutting+Operating) losses, (%)…..(3)
● Field capacity:
Theoretical field capacity was determined by the following equation:-
F .C th 
W V
.......... ....( 4 )
4 .2
Where:F.Cth = Theoretical field capacity, fed/h.
W = Theoretical width, m.
V = Machine speed, km/h.
Misr J. Ag. Eng., July 2006
519
Actual field capacity was the actual average rate of field coverage by the
amount of actual time (lost + productive time) consumed in the cutting
operation. It can be determined from the following equation:60
F .C act 
,  fed / h  .......... ....( 5 )
Tu  Ti
Where:F.Cact = The actual field capacity of the cutting machine.
Tu = The utilization time per feddan in minutes.
Ti = The summation of lost time per feddan in minutes.
● Field efficiency:
Field efficiency is calculated by using the following equation:F .C act
F .E 
 100 .......... ....( 6 )
F .C th
Where:F.E = Field efficiency of the cutting machine, (%).
F.Cact = Actual field capacity of the cutting machine, (fed/h).
F.Cth = Theoretical field capacity of the cutting machine, (fed/h).
● Energy consumed:
To estimate the engine power during cutting process, the decrease in benzene
fuel level in fuel tank accurately measuring immediately after each treatment.
The following formula was used to estimate the engine power (Embaby
1985):EP   f . c  1 / 3600  PE  L.C .V  427 thb  m  1 / 75  1 / 1.36  , kW ....( 7 )
Where:f.c = The fuel consumption, (l/h).
PE = The density of fuel, (kg/l ), (for benzene = 0.72).
L.C.V = The lower calorific value of fuel, (11.000 k.cal/kg).
thb = Thermal efficiency of the engine (25% for Otto engine).
427 = Thermo-mechanical equivalent, (Kg.m/k.cal).
m = Mechanical efficiency of the engine (85% for Otto engine).
So, the Energy can be calculated as following:Engine power  1.96 f .c . , kW / h .......... .......( 8 )
So, the energy can be calculated as following:Misr J. Ag. Eng., July 2006
520
Energy requiremen t 
Engine power ,( kW )
, kW .h / fed ........( 9 )
Field capacity ,( fed / h )
● Criterion cost:
The criterion cost of cutting operation was estimated using the following
equation (Awady et. al. 1982):Criterion cost / fed= Operating cost+ Grain losses, (L.E/fed) …….…..(10)
Where:Machine cos t ( L.E / h )
, ( L.E / fed )....( 11 )
Operating cos t / fed 
Actual field capacity ( fed / h )
Machine cost was determined by using the following equation (Awady 1978):m
P1 i

.......... .......... ...( 12 )
C     t  r   0.9 W .S .F  
144
h a 2

Where:C = Hourly cost, L.E/h.
P = Price of machine, L.E.
h = Yearly working hours, h/year.
a = Life expectancy of the machine, h.
i = Interest rate/year.
t = Taxes, over heads.
r = Repairs and maintenance ratio.
0.9 = Factor accounting for lubrications.
W = Engine power, hp.
S = Specific fuel consumption, l/hp.h.
F = Fuel price, L.E/l.
m = The monthly average wage, L.E.
144 = Reasonable estimation of monthly working hours.
In this study, the cutting machine was operated in rice and wheat crops at four
average grain moisture contents of (24.60, 23.12, 22.20 and 21.45 %); (22.76,
21.23, 20.10 and 19.11 %) for rice and wheat crop. The cutter bar operated at
constant velocity of 425 rpm (5.60 km/h) and different machine forward
speeds of (1.2, 1.8, 2.4 and 3.0 km/h), which gave different kinematic
parameters (k) of (4.67, 3.11, 2.33 and 1.8) for rice crop. Also, the cutter bar
operated at constant velocity of 365 rpm (4.80 km/h) and different machine
Misr J. Ag. Eng., July 2006
521
forward speeds of (1.5, 2.1, 2.7 and 3.3 km/h), which gave different kinematic
parameters (k) of (3.2, 2.29, 1.78 and 1.45) for wheat crop.
Total grain losses, field capacity and efficiency, fuel consumption and energy
requirements were measured under rice and wheat crops; various operating
kinematic parameters; and various grain moisture contents.
Grain moisture content was determined on dry basic with the oven method at
105oC for 24 hours in laboratory of faculty of agriculture, Zagazig University.
RESULTS AND DISCUSSIONS
The performance of the constructed cutting machine is sensitive to different
parameters such as: kinematic parameter (Ratio of cutter bar velocity and
machine forward speed), grain moisture content, plant type and others.
In this study, the discussion will cover the effect of some previous parameters
on the performance of the constructed cutting machine in terms of total grain
losses, field capacity and efficiency, cutting efficiency, fuel and energy
consumed, operating cost and criterion cost requirements.
1- Effect of machine forward speed on field capacity and efficiency:
The field capacity and efficiency are very important parameters which should
be taken into consideration when we evaluate machine performance. The
actual field capacity is affected by many factors such as effective machine
width, machine forward speed, cutter bar velocity and grain moisture content.
The effect of machine forward speed on actual field capacity is shown in fig. 4.
In rice crop, increasing machine forward speed from 1.5 to 3.0 km/h increased
actual field capacity from 0.277 to 0.452, 0.251 to 0.382, 0.208 to 0.349 and
0.181 to 0.296 fed/h. at different grain moisture contents of 21.45, 22.20, 23.12
and 24.60 %, respectively.
Misr J. Ag. Eng., July 2006
522
MC1
MC2
MC3
MC4
Rice crop
0.6
Field capacity, (fed/h)
Field capacity, (fed/h)
0.6
0.5
0.4
0.3
0.2
MC1
MC2
MC3
MC4
Wheat crop
0.5
0.4
0.3
0.2
0.1
0.1
0
0
1.2
1.8
2.4
3
Forward speed, km/h
1.5
2.1
2.7
3.3
Forward speed, km/h
Fig.(4): Effect of machine forward speed on actual field capacity under
different grain moisture contents in rice and wheat crops.
In wheat crop, increasing machine forward speed from ١.٥ to 3.٣ km/h
increased actual field capacity from 0.411 to 0.621, 0.381 to 0.523, 0.331 to
0.442 and 0.291 to 0.390 fed/h. at different grain moisture contents of 19.11,
20.10, 21.76 and 22.76 %, respectively.
The effect machine forward speed on field efficiency is shown in fig. 5. In rice
crop, increasing machine forward speed from 1.2 to 3.0 km/h decreased field
efficiency from 69.17 to 45.23, 62.84 to 38.17, 52.11 to 34.88 and 45.24 to
29.60 % at different grain moisture contents of 21.45, 22.20, 23.12 and 24.60
%, respectively. In wheat crop, increasing machine forward speed from 1.5 to
3.3 km/h decreased field efficiency from 82.15 to 56.34, 75.43 to 47.18, 66.72
to 40.10 and 58.20 to 35.24 % at different grain moisture contents of 19.11,
20.10, 21.76 and 22.76 %, respectively.
Results indicated that, the field efficiency decreased by increasing grain
moisture contents, these results may attribute to the difficult of machine
operation in moist plants which consumed more time.
2- Effect of grain moisture content on total grain losses:
Field grain losses were affected by maturity, time of harvesting, field
conditions, machine forward speed, cutter bar velocity and type of crop.
The effect of grain moisture content on total grain losses is shown in fig. 6.
The results indicated that the grain moisture content of 22.20 % and 20.10 %
gave the minimum total losses of at different kinematic parameters in rice and
wheat crops.
Misr J. Ag. Eng., July 2006
523
Generally, the decrease of grain moisture content less than 22.20 % and 20.10
% leads to increase the total grain losses due to more shattering grains by
cutter bar action during cutting operation. Also, the increase of grain moisture
content more than 22.20 % and 20.10 % leads to increase the total grain losses
due to increase un-cutting plants and more lodging plants in the field.
The minimum grain losses of 1.43, 1.03, 1.75 and 2.45 %; 1.11, 0.76, 1.31 and
1.58 % were recorded at different kinematic parameters of 1.8, 2.33, 3.11 and
4.67; 1.45, 1.78, 2.29 and 3.20 in both rice and wheat crop, respectively.
MC1
MC2
MC3
MC4
Rice crop
90
90
80
80
70
Field efficiency, (%)
Field efficiency, (%)
MC1
MC2
MC3
MC4
Wheat crop
60
50
40
30
20
10
70
60
50
40
30
20
10
0
0
1.2
1.8
2.4
3
1.5
Forward speed, km/h
2.1
2.7
3.3
Forward speed, km/h
Fig.(5): Effect of machine forward speed on field efficiency under different
grain moisture contents in rice and wheat crops.
k1
k2
k3
Rice crop
5
k4
Total grain losses (%)
Total grain losses (%)
5
4
3
2
1
0
k1
k2
k3
Wheat crop
k4
4
3
2
1
0
21.45
22.2
23.12
Moisture content (% )
24.6
19.11
20.1
21.23
22.76
Moisture content (% )
Fig.(6): Effect of grain moisture content on total grain losses under different
kinematic parameters in rice and wheat crops.
3- Effect of kinematic parameter on cutting efficiency:
The effect of kinematic parameter on cutting efficiency is shown in fig. 7. The
results obtained show that the increase in kinematic parameter values lead to
increase the cutting efficiency due to increase the number of cutting times in
the unit area which cause less of remaining straw.
Misr J. Ag. Eng., July 2006
524
In rice crop, the maximum cutting efficiency of 86.88, 83.16, 74.56 and 70.00
% were recorded at high kinematic parameter of 4.67 at different grain
moisture contents of 21.45, 22.20, 23.12 and 24.60 %. While, in what crop, the
maximum cutting efficiency of 97.53, 95.35, 94.12 and 91.41 % were recorded
at high kinematic parameter of 3.20 at different grain moisture contents of
19.11, 20.10, 21.76 and 22.76 %.
M.C1
M.C2
M.C3
Rice crop
100
M.C4
95
Cutting efficiency (%)
Cutting efficiency (%)
100
90
85
80
75
70
65
60
M.C1
M.C2
M.C3
Wheat crop
M.C4
95
90
85
80
75
70
65
60
1.8
2.33
3.11
4.67
kinematic parameter (k)
1.45
1.78
2.29
3.2
kinematic parameter (k)
Fig.(7): Effect of kinematic parameter on cutting efficiency under different
grain moisture contents in rice and wheat crops.
4- Effect of kinematic parameter on energy consumed:
Fuel and energy consumption for cutting rice and wheat crops depend mainly
on field capacity and some variable parameters such as specific gravity of
grains, plant and soil moisture content at the time of cutting operation,
machine forward speed and cutter bar velocity.
Fig.(8) show that, for rice crop, the minimum energy consumed of 2.97, 3.81,
4.95 and 6.82 kW.h/fed were obtained at kinematic parameter of 2.33 under
different grain moisture contents of 21.45, 22.20, 23.12 and 24.60 %. While
the maximum energy consumed of 7.65, 9.52, 12.36 and 15.69 kW.h/fed were
obtained at kinematic parameter of 4.67 under different grain moisture
contents of 21.45, 22.20, 23.12 and 24.60 %.
On the other side, for wheat crop, the minimum energy consumed of 1.53,
2.00, 2.86 and 3.76 kW.h/fed were obtained at kinematic parameter of 1.78
under different grain moisture contents of 19.11, 20.10, 21.76 and 22.76 %.
While the maximum energy consumed of 3.59, 4.34, 5.70 and 7.45 kW.h/fed
were obtained at kinematic parameter of 3.20 under different grain moisture
contents of 19.11, 20.10, 21.76 and 22.76 %.
Misr J. Ag. Eng., July 2006
525
M.C1
M.C2
M.C3
16
M.C4
14
12
10
8
6
4
2
0
1.8
2.33
3.11
4.67
kinematic parameter (k)
M.C1
M.C2
M.C3
Wheat crop
Energy consumed (kW.h/fed)
Energy consumed (kW.h/fed)
Rice crop
16
M.C4
14
12
10
8
6
4
2
0
1.45
1.78
2.29
3.2
kinematic parameter (k)
Fig.(8): Effect of kinematic parameter on energy consumed under different
grain moisture contents in rice and wheat crops.
Generally, the fuel and energy consumed increased rabidly by increasing the
kinematic parameter from the optimum value due to more cutting numbers by
the cutter bar per the unit area. While, the lower values of kinematic parameter
less than optimum value increase the fuel and energy consumed lightly due to
increase the cutting materials on cutter bar and the conveyor belt.
5- Effect of grain moisture content on operating cost requirements:
The operating cost for cutting operation depends on some variables such as;
machine price, engine power, specific fuel consumption, fuel price and yearly
working hours. The effect of grain moisture content on operating cost under
different kinematic parameters is shown in fig. 9.
For rice crop, the obtained data show that increasing grain moisture content
from 21.45 to 24.60 % increase operating cost rabidly from 37.50 to 57.26,
41.24 to 63.48, 45.44 to 65.70 and 61.19 to 93.65, L.E/fed at different
kinematic parameters of 1.8, 2.33, 3.11 and 4.67, respectively. Also, for wheat
crop, increasing grain moisture content from 19.11 to 22.23 % increase
operating cost rabidly from 34.26 to 54.46, 35.40 to 57.41, 41.65 to 60.69 and
51.80 to 73.24, L.E/fed at different kinematic parameters of 1.45, 1.78, 2.29
and 3.20, respectively.
Misr J. Ag. Eng., July 2006
526
k1
k2
Rice crop
k1
k2
Wheat crop
k3
120
k4
Operating cost (L.E/fed)
Operating cost (L.E/fed)
k3
100
90
80
70
60
50
40
30
20
10
0
k4
100
80
60
40
20
0
21.45
22.2
23.12
19.11
24.6
20.1
21.23
22.76
Moisture content (% )
Moisture content (% )
Fig.(9): Effect of kinematic parameter on operating cost under different grain
moisture contents in rice and wheat crops.
6- Effect of kinematic parameter on criterion cost requirements:
The criterion cost is highly affected by grain losses and its price. The results
indicated that the operating cost was about the half from criterion cost due to
grain losses as a result of cutter bar and conveyor belt action.
The effect of kinematic parameter on criterion cost is shown in fig. 10. The
data show that the lowest criterion cost of 72.18 and 64.82 L.E/fed were
recorded under kinematic parameter of 2.33 and 1.78; and grain moisture
content of 22.20 and 20.10 % for rice and wheat crop, respectively.
Also, the highest criterion cost of 164.97 and 201.68 L.E/fed was recorded
under kinematic parameter of 4.67 and 3.20; and grain moisture content of
24.60 and 22.76 % for both rice and wheat crop, respectively.
M.C1
M.C2
M.C3
M.C4
Rice crop
200
225
Criterion cost (L.E/fed)
Criterion cost (L.E/fed)
225
175
150
125
100
75
50
25
M.C1
M.C2
M.C3
Wheat crop
M.C4
200
175
150
125
100
75
50
25
0
0
1.8
2.33
3.11
4.67
kinematic parameter (k)
1.45
1.78
2.29
3.2
kinematic parameter (k)
Fig.(10): Effect of grain moisture content on criterion cost under different
kinematic parameters in rice and wheat crops.
Misr J. Ag. Eng., July 2006
527
CONCLUSION
A self propelled machine for cutting cereal crops was constructed and
manufactured by making a design allow to cut plants using single acting cutter
bar and convey cutting plants aside of the machine using flat conveyor belt.
Data from this study led to the following conclusions:
1- The highest field capacity in rice and wheat crops resulted from low
kinematic parameters and low grain moisture contents.
2- The highest field efficiency in rice and wheat crops resulted from high
kinematic parameters and low grain moisture contents.
3- The minimum grain losses in rice and wheat crops resulted from kinematic
parameter of 2.33 and 1.78; and grain moisture content of 22.20 and 20.10
%.
4- The maximum cutting efficiency in rice and wheat crops resulted from
high kinematic parameters and low grain moisture contents.
5- The lowest fuel and energy consumed in rice and wheat crop resulted from
kinematic parameter of 2.33 and 1.78; and low grain moisture content of
21.45 and 19.11 %.
6- The minimum operating cost in rice and wheat crops resulted from low
kinematic parameters and low grain moisture contents.
7- The minimum criterion cost in rice and wheat crops resulted from
kinematic parameter of 2.33 and 1.78; and grain moisture content of 22.20
and 20.10 %.
REFERENCES
Awady, M. N. (1978): Tractor and farm machinery. Text book, Faculty of
Agriculture, Ain-Shams University, pp. 164-167.
Awady, M. N; E. Y. Ghoneim and A. I. Hashish (1982): A critical
comparison between wheat combine harvesters under Egyptian
conditions. R. S. No. 1920, Ain-Shams Univ. (FAO). J.
Badr, M. M. (2005): Comparative study between some different combine
sizes in respect to unit plot area. M. Sc. Thesis. Agric. Eng. Dept.,
Faculty of Agric., Zagazig Univ. Egypt.
Misr J. Ag. Eng., July 2006
528
Devani. R. S. and M. M. Pandey (1985): Design, development and
evaluation of vertical conveyor reaper windrower. AMA, 16 (2): 4152.
El-Danasory, M. M. (1987): Intensifying the use of mowers under Egyptian
conditions. M. Sc. Thesis. Agric. Eng. Dept., Faculty of Agric., Cairo
Univ. Egypt.
El-Sharabasy, M. M. A. (1997): Selecting the proper system for mechanizing
grain crops harvesting in the small holdings. M. Sc. Thesis. Agric.
Eng. Dept., Faculty of Agric., Zagazig Univ. Egypt.
El-Sahrigi, A.F; A.S. Haman and Y. F. Sharobeem (1992): Development of
tractor front mounted reaper windrower. (c. f. Samy et.al. 1997) Misr
J. Agric. Eng. 14 (1): 50-67.
Embaby, A. T. (1985): A comparison of the different mechanization systems
for cereal crop production. M. Sc. Thesis, Agric. Eng. Dept., Faculty
of Agric., Cairo Univ. Egypt.
Habib, R. A; B. S. Azzam; G. M. Nasr and A. A. Khattab (2001): A
theoretical analysis of the " Free-cutting process" of plant materials.
1St International Conference for Manufacturing Agricultural
Equipment and Machinery. 9th Conference of Misr Society of Agric.
Eng., 9-11 September.
Habib, R. A; B. S. Azzam; G. M. Nasr and A. A. Khattab (2002): The
parameters affecting the cutting process performance of agricultural
plants. Misr J. Agric. Eng. 19 (2): 361-372.
Hadidi, Y. M. (1984): A study on mechanical mowing. M. Sc. Thesis. Agric.
Eng. Dept., Faculty of Agric., Mansoura Univ. Egypt.
Hanna, G. B. and A. E. Suliman (1986): Appropriate harvesting equipment
for small Egyptian farms. Misr J. Agric. Eng. 3 (1): 58-72.
Metwalli, M. M; S. M. Sharaf; F. I. Hindy and I. A. El-Motalb (1981):
Economic performance of self propelled mower. J. Agric. Res., Tanta
Univ. 7 (1): 20-24. Egypt.
Metwalli, M. M; M. A. Helmy; S. M. Gomaa and H. A. Khateeb (1995):
Evaluation of different mechanical methods of cutting and chopping
cotton stalks. Misr J. Agric. Eng. 12 (1): 205-217.
Misr J. Ag. Eng., July 2006
529
‫‪Mahrous, A. M. (1995): Improvement of reciprocating mower efficiency‬‬
‫‪under different crops. M. Sc. Thesis. Agric. Eng. Dept., Faculty of‬‬
‫‪Agric., Zagazig Univ. Egypt.‬‬
‫‪Morad, M. M. (1995): Optimizing the rotary mower kinematic parameter for‬‬
‫‪minimum cost. Misr J. Agric. Eng., Vol. 12 No. 2, 1995.‬‬
‫‪Murthy, C.N.N. (1989): Tractor-mounted reaper for efficient wheat‬‬
‫‪harvesting. Farmers Journal. 9 (9): 32-33.‬‬
‫‪Sahar, E. A. (1988): Design of a harvester appropriate for Egyptian‬‬
‫‪Agriculture. M. Sc. Thesis, Agric. Eng. Dept., Faculty of Agric., Ain‬‬
‫‪Shams Univ. Egypt.‬‬
‫‪Singh, G; A. P. Chaudhary and D. G. Clough (1988): Performance‬‬
‫‪evaluation of mechanical reaper in Pakistan. AMA, 19 (3): 47-52.‬‬
‫الملخص العربي‬
‫تركيب وتصنيع آلة ذاتية الحركة تالئم عملية تقطيع بعض محاصيل الحبوب‬
‫لتقليل الفواقد وتعظيم الكفاءة‬
‫د‪ .‬محب محمد أنيس الشرباصي‬
‫*‬
‫يعتبر األرز والقمح من المحاصيل اإلستراتيجية الھامة في مصر‪ .‬وفي ظل التوسع األفقي للرقعة‬
‫الزراعية باستصالح أراضي جديدة وفي ظل تفتت الحيازات الزراعية في الدلتا فإن الحاجة مازالت‬
‫قائمة الستخـدام العديـد من اآلالت التي تـقوم بحصـاد محاصيل الحبوب عوضا ً عن آلة الحصـاد‬
‫والدراس )الكومباين( وخاصة في محصول القمح بأقل تكاليف ممكنة‪ .‬فاستخدام آالت الحصاد‬
‫بأنواعھا المختلفة يعطى الفرصة للمزارع بسرعة إخالء األرض وكذلك يحد كثيراً من الحصاد‬
‫اليدوي الذي يزيد فواقد الحبوب ويستھلك الجھد والمال‪.‬‬
‫ويھدف ھذا البحث إلى تصنيع آلة ذاتية الحركة تقوم بتقطيع العديد من المحاصيل الحقلية واسعة‬
‫االنتشار في مصر وھى األرز والقمح وذلك بغرض تعظيم الفائدة من ھذه اآللة وجعلھا أكثر‬
‫استخداما ً طوال العام باإلضافة إلى تقليل فواقد الحبوب والقش في كالً من محصولي األرز والقمح‬
‫وتعظيم كفاءة القطع لتوفير تكاليف الحصاد اليدوي وإيجاد البديل المناسب آللة الحصاد والدراس‬
‫)الكومباين( وخاصة عند حصاد محصول القمح‪.‬‬
‫ھذه اآللة تتركب من أربع أجزاء رئيسية ھي‪:‬‬
‫‪ -١‬قضيب القطع‪ :‬طوله ‪ ١٤٠‬سم وھو من النوع الفردي الفعل ويحتوي على ‪ ٢٨‬سكين مثلث الشكل‬
‫يتحرك فوق قضيب ثابت يحتوي على نفس العدد من السكاكين‪.‬‬
‫*مدرس – قسم الھندسة الزراعية ‪ -‬كلية الزراعة – جامعة الزقازيق –‬
‫‪530‬‬
‫‪Misr J. Ag. Eng., July 2006‬‬
‫‪ -٢‬الدرفيل‪ :‬طوله ‪ ١١٥‬سم وھو سداسي األوجه به ‪ ٦‬عوارض مركب عليھا ‪ ٦٠‬شوكة تساعد على‬
‫رفع ومسك النباتات أثناء القطع وكذلك نقل النباتات المقطوعة إلى السير الناقل‪.‬‬
‫يركب الدرفيل على إطار على شكل حرف )‪ (L‬إلمكانية التحكم في المسافة بين المحور الطولي‬
‫للدرفيل وقضيب القطع وكذلك التحكم في ارتفاع الدرفيل عن قضيب القطع‪ ،‬ويأخذ الدرفيل حركته‬
‫من العجلة األرضية لآللة عن طريق سير وطارتين‪.‬‬
‫‪ -٣‬السير الناقل‪ :‬طوله ‪ ١٢٥‬سم وعرضه ‪ ٤٨‬سم ويركب خلف قضيب القطع مباشرةً على‬
‫اسطوانتين قطر كل منھما ‪ ٨‬سم وطولھا ‪ ٥٠‬سم ويتحرك أفقيا ً لنقل النباتات المقطوعة على جانب‬
‫اآللة‪ .‬يستمد السير الناقل حركته من عمود القدرة الخارج من المحرك عن طريق سير وطارتين‪.‬‬
‫‪ -٤‬جھاز نقل الحركة‪ :‬يتركب ھذا الجھاز من صندوق تروس وطارتين وسير ووصلة مرنة وعمود‬
‫نقل القدرة إلى قضيب القطع المتحرك‪ .‬يقوم ھذا الجھاز بنقل الحركة من المحرك إلى قضيب القطع‬
‫بنسبة تخفيض )‪ (١ :٤.٢٨‬ويتم تحويل الحركة الدورانية لعمود القدرة إلى حركة ترددية على قضيب‬
‫القطع بواسطة عمود مرفق قطر ركبته ‪ ٧‬سم ھي المسافة بين السكاكين على قضيب القطع‪.‬‬
‫أظھرت النتائج المتحصل عليھا ما يلي‪-:‬‬
‫ أعلى سعة حقلية وأقل تكاليف تشغيل لآللة تحققت عند المعامل الكينماتيكي المنخفض وھو )‪،١.٨٠‬‬‫‪ (١.٤٥‬ورطوبة الحبوب المنخفضة أيضا ً وھي )‪ (٪ ١٩.١١ ،٢١.٤٥‬لمحصولي األرز والقمح‪،‬‬
‫على الترتيب‪.‬‬
‫ أعلى كفاءة حقلية وكفاءة قطع لآللة تحققت عند المعامل الكينماتيكي المرتفع وھو )‪(٣.٢٠ ،٤.٦٧‬‬‫ورطوبة الحبوب المنخفضة وھي )‪ (٪ ١٩.١١ ،٢١.٤٥‬لمحصولي األرز والقمح‪ ،‬على الترتيب‪.‬‬
‫ أقل فواقد للحبوب تحققت عند المعامل الكينماتيكي المنخفض وھو )‪ (١.٧٨ ،٢.٣٣‬ورطوبة‬‫الحبوب المنخفضة وھي )‪ (٪ ٢٠.١٠ ،٢١.٤٥‬لمحصولي األرز والقمح‪ ،‬على الترتيب‪.‬‬
‫ أعلى كفاءة قطع لآللة تحققت عند المعامل الكينماتيكي المرتفع وھو )‪ (٣.٢٠ ،٤.٦٧‬ورطوبة‬‫الحبوب المنخفضة وھي )‪ (٪ ١٩.١١ ،٢١.٤٥‬لمحصولي األرز والقمح‪ ،‬على الترتيب‪.‬‬
‫ أقل استھالك للوقود والطاقة لآللة تحقق عند المعامل الكينماتيكي )‪ (١.٧٨ ،٢.٣٣‬ورطوبة الحبوب‬‫المنخفضة وھي )‪ (٪ ١٩.١١ ،٢١.٤٥‬لمحصولي األرز والقمح‪ ،‬على الترتيب‪.‬‬
‫ أقل تكاليف حرجة لآللة تحققت عند المعامل الكينماتيكي )‪ (١.٧٨ ،٢.٣٣‬ورطوبة الحبوب‬‫)‪ (٪ ٢٠.١٠ ،٢٢.١٠‬لمحصولي األرز والقمح‪ ،‬على الترتيب‪.‬‬
‫ وبالتالي فإن أنسب العوامل لتشغيل ھذه اآللة والتي تعطي أقل تكاليف حرجة ھي‪:‬‬‫السرعة األمامية لآللة )‪ ٢.٧٠ ،٢.٤٠‬كم‪/‬س( والسرعة الترددية لسكين القطع )‪٤.٨٠ ،٥.٦٠‬‬
‫كم‪/‬س( التي تعطي معامل كينماتيكي )‪(١.٧٨ ،٢.٣٣‬؛ ونسبة رطوبة للحبوب أثناء القطع )‪،٢٢.٢٠‬‬
‫‪ (٪ ٢٠.١٠‬لمحصولي األرز والقمح‪ ،‬على الترتيب‪.‬‬
‫‪531‬‬
‫‪Misr J. Ag. Eng., July 2006‬‬