Design and Development of Multi Crop Cutting Machine

Abstract

In India agriculture is need to concentrate in some situation to increase the productivity and profit to reduce the cost and labor effort. This paper tends to provide the design and development of manually or mechanically operated MULTI CROPS CUTTING MACHINE. The current situation in our country the traditional use of harvesting mechanism is more tedious, time consuming and not able to develop the agriculture sector of the low farmers in economic. Depending on the problem stated through abstraction of literature and the existing reapers, to satisfy the customer needs are gathered as data has been interpreted to meet the requirement of the objective of the problem. The idea was to create a machine which is cheap and will reduce the labor required to harvest crops. Small scale farmers can use this machine. This machine is compact and capable to cut up to 2 rows of maize stalk, bajara stalk. It has a high strength cutting blade which cuts the crops in a rotary type motion. It runs on a engine of 3HP, this power from engine is provided through pulley and gear box arrangement to the cutter. A collecting mechanism is provided for the collection of crops to one side of the machine after cutting. There are some steps involved in fabricating of this machine such as fabricating the small model using suitable material and test the functioning of this machine. So the aim is to fabricate and test the performance of the small model of a manually or mechanically operated crop cutter for cutting crops. Fast cutting of crop can give more time for preparation of land for next crop planting.

This harvester is manufactured by using locally available spare parts and it is easily maintainable. This harvester might be the solution to the problem faced by a small scale farmer regarding labor implementation and cost.

Introduction

In this modern world the use of agriculture equipment is increasing continuesly. India uses only 10% agriculture equipment’s as conducted survey in year 2012. India has second rank in agriculture field. Agriculture like forestry and fisheries accounted for 13.7% of the GDP (Gross Domestic Product) in 2013, about 50% of the total manpower. The economic contribution of agriculture in India’s GDP is continuously decreasing with the country’s broad-based economic growth.Farming is most widely followed profession in India. Agriculture products contributes a major portion to our economy. Engineering science has brought enormous changes in traditional methods of agriculture like sowing, planting, irrigation, fertilizer, spraying, harvesting, etc. However to increase our economic condition, we must increase the productivity and quality of our farming activities. Nowadays only few skilled labours are available for agriculture. Because of this drawback, the farmers prefer to use reaper harvesters. These reapers are costly and only available for very large scale farming. However, agriculture groups use these available on an hourly basis for rent. But the small scale farm owners generally do not require the full-featured combine harvesters. Also, these combine harvesters are not available in all state of rural India due to financial or transportation reasons. Thus, there is a need for a smaller and efficient combine reaper which would be more accessible and also considerable cheaper. This mission is to create a portable, user-friendly and low cost mini harvester.

Taking into account the requirements of current situation, the idea was created to prepare a machine which is cheap and will reduce the labor required to cut the crops. The requirement of this model is the demand for a compact and economical reaper. This drawback is taken into consideration for this project. Taking into account the present scenario of corn harvesting we decided to prepare a model of corn reaper which will suitable for farmers having small land for agriculture. The machine prototype will be more economical and convenient for cutting corn stalks and other similar plants having same or less shear strength than corn.

Literature survey

Until the 19th century, most crops was harvested by cutting with a sickle. A sickle is a curved, hand-held agriculture tool typically used for harvesting crops before the advent of modern harvesting machinery. The inside of the curve is sharp, so that the user can swing the blade against the base of the crop, catching it in the curve slicing it at the same time. Around the start of the 20th century animal drawn machines, “combines’’, were developed that integrated cutting, threshing, and separating wheat and small crops.A reaper has been designed and fabricated at the University of Faisalabad in Pakistan. This was a 5kw gasoline engine fitted self-propelled reaper (without conveyor) can harvest a hectare in 2.5hours, and is equally effective for forage crops and wheat, rice. A tractor front mounted reaper has been developed in 1980, at agriculture Mechanization research institute (AMRI), multan Pakistan. The v-belt drive is used as a power transmitting mechanism in this is project. The mechanism is hydraulically operated through the 3 point linkage. The vertical conveyer type reaper was developed in people`s Republic of china, this was a 8.95kw diesel engine fitted reaper having a field capacity of about 0.65ha/hr. it is an engine operated, walking type harvester suitable for harvesting maize stalk and bajara stalk.

Grag et al. (1985) designed and developed a front mounted vertical conveyer reaper windrower of 1.9m cutting width, operated by a tractor of about 25hp, could effectively harvested.Hadidi et.al (1984) stated that, the height of crop stubbles increasing as stalks moisture content increased and decreased with increased of knife velocity. He added that the percentage of wheat and rice grain losses increased as the machine forward speed increased. If we Increase the cutter bar speed then it will leads to decrease the percentage of grain losses. Also, the increament of forward speed leads to increase the number of uncut stalks. Sahar (1998,reported that, the use of a large scale machine is inappropriate for the following reason –it needs high technical experience for operation and maintenance, high capital requirements.The use of small machines is appropriate for small holdings, low capital requirements and low technical operation and maintenance experience. EI-sharigi et.al(1992), developed a front mounted reaper. The design features included a flat belt mechanism conveying the crop to the side of the machine, improve cutter bar star wheel assembly to minimize clogging a bevel gear drive for power transmission,a robust frame , a header provide design that will not dig in to the soil and provisions to convert the flat belt conveyor drivers to the chain without frame modification.

Habib et al (2002) stated that the parameters affecting cutting process are related to cutting tool ,machine specifications and plant material properties .They added that cutting energy consumed in harvesting process.Badr(2005) compared the performance of the three different combines in terms of harvesting time, grain losses, fuel consumption, energy required and total cost. He found that the highest capacity of field is 3.02 acre/h and the lowest field efficiency of 70.5% were obtained at forward speed about 4.0km/h and grain moisture content of 22% D.N. Sharma and S.Mukesh, studied on the designing of handle and in that study approximate 100cm height is sufficient for pushing of any machinery. DR.U.V. Kongre (2016) Introduction a new type of modified cutter which can reduce dependent to workers which give much effect in maximizing the profit to the farmers. The work was carried out with objective to design modification and evaluate the performance of manual operated reaper. Imrul Kaes Mirza kiran (2016) Bangladesh is basically an agriculture country about 80% of the total population lives in rural areas and 95% of them are involved with agriculture activites. The largest delta in the world and is situated between 88.01 and 92.4 degree east longitudes and between 20.34 and 26.38 degree north latitudes. As the deltaic land is very fertile and the climate favourable for the production of cereal crops like paddy, wheat. So timely harvesting of the crop is very important. Crops are susceptible shattering if harvesting is delayed. The labour shortage is felt during harvesting season because time available for harvesting by sickle which quite tedious and labour intensive. During the harvesting period there is scarcity of labour and harvesting is normally delayed resulting in greater losses f crops on the field.

Methodology

Planning:

It is planned that as a solution to this problem, mechanical weeder was designed and developed will be able to fulfill the present requirement for the weed control. Accordingly, the present development is directed to an improved manual tilling, mulching and weeding control with low effective operation, low work effort and high time requirement for different types of hoe and cutlass can be overcome with the use of mechanical weeder.

Designing:

The components which are required to use in the machine are to be designed such as frame, handle, chain sprocket, blades, wheels and spring using the drawing software.

Material purchasing:

After the completion of designing the components, the material should be selected and purchased as per the required following properties for our work.

Selected material (mild steel):

• AISI 1018 mild/ low carbon steel has excellent weld ability and produces a uniform and harder case.
• It is considered as the best steel for carburized parts.
• AISI 1018 mild/low carbon steel offers a good balance of toughness, strength and ductility.
• Provided with higher mechanical properties, AISI 1018 hot rolled steel also includes improved machining characteristics and Brinell hardness.

Fabrication:

The fabrication is the process of making the required components for the machine. Frame is fabricated by cutting, drilling, and welding processes. The rectangular shaft is machined by drilling, cutting and machining in the lathe and drilling machine. Frame is manufactured by cutting and welding. Machine is fabricated as according to our comfort to multi crop cutting. Hence now all the components are fabricated which are to be used in the machine.

Assembling: Now all the fabricated components are to be assembled as per the follows;

• Frame
• Engine
• Wheels
• Chain
• Gear box
• Conveyor
• rotary blades

Design calculation

Shaft Calculation

Length of shaft = 2m =2*10^3

Power =50 kw =50 *10^3 watts

Speed =200 rpm

Ʈ= 60 mpa =60 N/mm^2

Allowable twist = 2® =2*π/180= 0.0349 radians

G= 80 *10^5 N/mm^2

Refer the value from design data book

Mt= twisting moment required N- mm

d^3 =16/π(Ʈ) ( kbmb)^2+(ktmt)^2 kb and kt values are assumed in data book

kb= combined shock and fatigue factor to mb

kt= combined shock and fatigue factor to mt

Assume kb =kt =1

d^3= 16/π(Ʈ) ( mb^2+mt^2)

p = 2πNT ( mt) /60

50 *10 ^3 =2 π * 200 *mt /60

Mt =397.88 *10 ^3 N-mm= 16 /π ( 60 ) ( 275 * 10 ^3) + ( 397.88 *10 ^ 3) ^2

d^2 = 41055.9

d= 34.4 mm

According to R20 series select the nearest highest value

Dia of the shaft = 35 mm

Diameter of angle in twist

Mt/J = G ϴ / l

Mt = 397.887 *10 N-mm

J = π/ 32 d^4

G = 80 * 10 ^3 N/mm^2

ϴ = 0.0349 radians

l =2m =2*10 mm

( 397.887 *10 ^3 / (d) ^4 = 80 *10 ^3 0.0349/ 2*10 ^3)

d= 41.27 mm

select shaft diameter = 45 mmchain drive calculation

P=3KW

N1=100RPM

N2=42RPM

C=1.2M

Design load for the given power

Q=p.ks.knv

Ks= service factor

Ks=k1.k2.k3.k4.k5.k6

Ks=1.25*1.0*1.0*1.25*1.0*1.25

Ks=1.95=(2)say

Transmission ratio i=N1/N2=100/42=2.4

For i=2.4 choose Z1=25

Z2=i*Z1=2.4*25

Z2=60

Hence kn=7.8 (for ks 1,Z1=25,and N1=100rpm)

Assume the centre distance

a= 40P

P=a/40

P=1200/40

P=30mm

Next standard pitch valve P= 31.75

Chain velocity V=P*Z1*N1/60*1000

V= 31.75*25*100/60*1000

V=1.32m/s

Hence the design breaking load

q=p*ks*kn/V

q= 3000*2*7.8/1.32

q=35455N checking for actual factor of safety

Actual factor of safety (kn)= q/

Where, =Ft+Fc+FsNow;Ft= tangential force due to power transmission=P/v=3000/1.32

Ft=22.73NFc= centrifugal tension=wv^2/g=38*1.32^2/9.81=6.75NFs= tension due to chain=k*w*a =2*38*1.2

Fs=91.2N=2273+6.75+91.2=2371N

Hence (kn)=Q/=88500/2371=373Since the actual factor of safety is more than adopted M.valve. The chain selection is correct.

Checking for induced bearing stress= P.ks/a*v=3000*2/262*1.32=17.3N/mm^2

This induced stress is less than the allowed bearing stress

Hence the chain select is correct.

Pitch diameter of the sprocket: For pinion d1= p/sin(180/Z1)= 31.75/sin(180/25)=253mm

For wheel d2= p/ sin(180/Z2)= 31.75/sin(180/60)=607mm

Tip diameter of sprockets

For pinion = da1= p/tan (180 /z1)+0.6p= 31.75/tan(180/25)+(60 *31.75)= 270mm

For wheel =da2= p/tan (180 /z2) +0.6p= 31.75/tan(180/60)+(0.6*31.75)= 625mm

Minimum centre distance= (da1+da2/2) +40=270 +625/2 +40= 488mm

Maximum centre distance=80 p= 80*31.75= 2540mm

Length of chain multiplies of pitch Lp= 2ap+( Z1+ Z2/2)+( (Z2+Z1)/2π)^2/ap ap= ao/p= 1200/31.75=37.5

Lp = 2*38 +( 25+60/2) +((60-25)/2π)^2/ 38=120 pitches

Length of the chain L= Lp*p= 120 * 31.75= 3810mm

a=(e+ e^2-8m)/4*p

e=Lp- (Z1+Z2/2)= 120-(25+60/2)= 77.5

M=(Z2-Z1/2π)^2= (60-25/2π)^2= 31

a= (77.5 + 77.5^2 -8 *31/4 )* 31.75=1218mm

Centre distance decrement = 0.5= 0.5*0.02*a= 0.5*0.02*1218=12mm

Required centre distance = a = 1218-12= 1206mm

Force on Worm Wheel

For worm and worm wheelZ1= Number of starts on the worm=3Z2= Number of teeth on the worm wheel= 15q= Diameter quotient=10m=module=10mmd1= diameter of worm wheeld1= q.md1= 10*10= 100mmd2= diameter of worm= z2*md2=15*10d2= 150mm

Conclusion

This multicrop cutting machine which will counter the problem of cutting corn plants manually for small scale farms. It can be concluded that the machine is comparatively small in size and easy to handle. This machine is able to run off field effortlessly and efforts of farmer are reduced. The operational cost using this machine is considerably less as compared to manual reaping. The reaper available in market are suitable for large farms so this can be best reaper for the farmers with small field.