Design and manufacture of protective el=
ements
to prevent accidents in the agricultural machinery of Ecuador, two cases of
study in automotive elements.
Edison
Marcelo Castillo Cárdenas.[1]=
,
Víctor David Bravo Morocho.
[2]=
, Edison
Patricio Abarca Pérez.
[3]=
,
Edgar Fabián Sánchez Carrión.
[4]=
&
DOI: =
https://doi.org/10.33262=
/cienciadigital.v2i3.146
The present work deals with the exposure, analysis=
and
source of risks the two common work accidents and of greater impact in the
Agricultural Mechanization Centers, internal part of MAG (Ministry of Agriculture and Livest=
ock of
Ecuador) whose main machine after the tractors and the which it is the obje=
ct
of study in the present treaty is the YTO DF 15l model walking tractor: a)
blows and bruises due to the ignition system, b) trapping and bruises due to
the blades of the tillage element (rotavator). The most viable solutions are
designed, manufactured, implemented and validated from the technological and
economic point of view, the solutions were proven in the field and they are
effective, however there are problems due to the implementation of the igni=
tion
system that leads to a new mass center of the tiller and there are
maneuverability problems.
Keywords: Walking Tractor,
Incidence Index, Accidents, Blades, Ignition Sytem.
El
presente trabajo aborda la exposición, análisis y fuente de riesgos de los =
dos
accidentes laborales comunes y de mayor impacto en los Centros de Mecanizac=
ión
Agrícola, parte interna del MAG (Ministerio de Agricultura y Ganadería de
Ecuador) cuya máquina principal después de los tractores y la cual El objeto
del estudio en el presente tratado es el tractor a pie modelo 15 de YTO DF:=
a)
golpes y hematomas debidos al sistema de encendido, b) atrapamiento y hemat=
omas
debido a las cuchillas del elemento de labranza (rotav=
ator).
Las soluciones más viables se diseńan, fabrican, implementan y validan desd=
e el
punto de vista tecnológico y económico, las soluciones fueron probadas en el
campo y son efectivas, sin embargo, existen problemas debido a la implement=
ación
del sistema de ignición que conduce a una nueva centro de masa del timón y =
hay
problemas de maniobrabilidad.
Palabras
Claves:<=
span
style=3D'mso-bookmark:_Toc440896901'> Tractor
para Caminar, Índice de Incidencia, Accidentes, Cuchillas, Sistema de Encen=
dido.
Introducción .=
Crank knock of the tractor to the operator.
Blows, bruises and entrapment of the operator due to the runaway of
the tiller (inability to maneuver the device), this occurs for two fundamen=
tal
reasons: the first is that the tiller to break the ground rested only work =
in
first and second gear if mistakenly engages an upper gear runs rampaging the
operator in any direction, the second reason is that after approximately 2
hours of work there is a discontinuity in the process of transmission of
movement and the walking tractor literally starts jumping for no apparent
reason , initially a thermal fault was thought and the problem came from the
combustion engine since the problem started with an apparent overload of the
engine and it started to give off blackish smoke, but then it was found that
the effect was in the transmission system and that the shocks occurred in t=
his
area, if the operator was working in the time range described (after two ho=
urs)
there was an enormous probability that it would be dragged or lifted by the=
motocultor, dragging the operator inside and the most
dangerous: falling and being caught between the blades of the rotavator, the
exposed stage took the life of a person in the community of Achupallas,
in Chimborazo.
Wound by pieces of blades on the feet, the tiller presented the
disadvantage that in the first hours of work the blades of the milling mach=
ine or
in English known as "rotavator" broke, these pieces obviously were
buried in the ground and being impossible to see with the naked eye, then t=
he
operator or another person who walked had the chance to splinter with such
sharp pieces.
Poor posture in the driver's seat generated back pain in a short t=
ime,
which could eventually be said to generate an occupational disease.
There are few studies related to the subject in question, only refer=
ence
is made to work accidents in different spectrums of the industry, among the
relevant topics investigated and taken as reference is "Incidence of w=
ork
accidents declared in Ecuador in the period 2011-2012" [3], there are =
no
specific topics related to the subject dealt with.
The main objectives of this document are to show the design and
manufacture of elements that counteract the risks during the days of work w=
ith
agricultural machinery; implement the elements of protection in the motocultores that are part of the agricultural
mechanization centers belonging to the Ministry of Agriculture and Livestoc=
k of
Ecuador for subsequent studies to quantify the tacit reduction of work-rela=
ted
accidents in the subject.
Being clearly descriptive this document is about directly attacking =
the
problem that in this case is: the direct relationship between the lack of an
electric ignition system in the mentioned rototiller and its manual ignitio=
n by
means of crank generates accidents, these accidents can occur because not
having the corresponding expertise is turned on the crank and sometimes the
heat engine gives a countermaquinazo which resu=
lts in
a blow to the person who is trying to start the rototiller, another risk is
that the person does not have the right knowledge of what your position sho=
uld
be with respect to the rototiller at the moment of ignition, once it begins=
to
overcome the inertia and start working the heat engine the crank can drag t=
he
person to the floor hitting it, or alternatively the crank to the person who
lit the rototiller; This problem is solved through the implementation of an
electrical ignition system to the aforementioned walking tractor.
Another problem that was narrated was the short life of the blades of
the milling machine (main organ of tillage of the tiller), the same that wh=
en
being buried and being the result of a fracture were sharp elements for
farmers, the solution was to improve the reliability of said elements of
tillage through some tests and then the implementation of the technological
solution.
The scope of this research is directly reducing ac=
cidents
in the agricultural sector through the implementation of an electric igniti=
on
system and the solution of the problem of low reliability of the blades of =
the
tiller element of the tiller and thus attack two problems directly: improve
productivity with the reliability of the milling machine and reduce acciden=
ts
due to chipping.
Importance of the problem.
In Ecuador there is a study from the year 2011 onw=
ards
since there are no data tabulated before
at that date in the matter of work accidents decla=
red
to the IESS [3] (Ecuadorian Institute of Social Security), the ignorance of=
the
incidence rates in the workplace accidents does not allow to contribute with
efficient policies in occupational health and safety.
The incidence of occupational accidents within the
agricultural machinery is an important aspect to be taken into account in t=
he
industry is the fourth group in number of work accidents (TA) behind the
manufacturing industry, community and social service and commerce in genera=
l (
figure 1), "According to the data of the Agrifood=
Statistics Yearbook in 2009, both in the agri-food industry and in agricult=
ure,
annually more than 30,000 workers are involved in accidents during their
workday" the data is from Spain. [4].
Graphic 1.
Number of work accidents according to work activity.
Source: Gómez,
A y Suasnavas, P. Ecuador, 2015.
Methodology.
Graphic 2. Study
walking tractor
Source: Author y author. Ecuador. 2018,
The methodology that was carried out was to observe the different
positions that the farmer takes to light the rototiller and which one gener=
ates
a greater risk at the moment of lighting, it is probable that a
counter-machining occurs and the direction of rotation of the motor which w=
ill
generate a severe concussion to the person (there is a serious case of this
type that was not recorded as a Work Accident), there may be a second scena=
rio
where the base of the crank has not been well placed in the notch At the
beginning of the movement, the person may lose their balance and hit both t=
he
torso and the hands against the rototiller. These injuries are not reported
because, according to farmers' criteria, this incident is not important.
To solve the problem has been proposed and carried out the total
suppression of the old system of ignition by crank and replaced by an elect=
ric
ignition system that is very common with the ignition system of a conventio=
nal
car, ie consists of the following elements in i=
ts
ignition system: battery or accumulator, connection cables, switch or switch
and starter engine.
The inertia flywheel of the tiller was machined so that on its perip=
hery
is placed a toothed crown that is in accordance with the bendix
(cogwheel connection with the flywheel) of the starter (that the teeth of b=
oth
the ring gear as of the starter they can mesh with each other without
difficulty, which can not be too loose or too t=
ight),
as can be seen in figure 3, then the selection of the ideal starter for the
proposed equipment was made if
Graphic 3. Starter assembly and cogwheel of the
flywheel.
Source: Sánchez. Ecuador 2016.
Some critical aspects are considered at the time of selection such a=
s: environmental
conditions, electrical protection index (in this case it does not apply sin=
ce
it is direct current), installation disposition (in this case it is an
adaptation and it is probable that it does not have support devices to the
original base), nominal power (perhaps the most important since it must move
and drag a 16HP heat engine [7]), the work cycles (relatively low since it =
will
only influence the ignition of the tiller), rotation speed (in this aspect =
it
is common for starters that their torque is high but their rotation speed is
low), efforts and loads to do the job (the starter will not be subjected to
greater efforts), there is to say that both the starter motor and the
rototiller are of Chinese origin as shown in figure 4.
Graphic 4. Technical data of the starter motor.
Source: Sánchez. Ecuador.2016.
When implementing the electric ignition system, it is easy to start =
the
tiller with only a key and when contact is made, the risk of knocks by countermachine and by imbalance of the operator is ta=
ngibly
reduced.
As mentioned in previous lines, another of the most pressing problem=
s is
the breaking of the blades, this problem occurs because the Chinese walking
tractor was designed exclusively to till the soil destined for rice cultiva=
tion
in its country of origin and therefore the benefits are different, the aver=
age
hardness of the soil is totally different and the working conditions are
different: while in Ecuador it has been tried to use the tiller to break the
firm soil and more or less humid the other side of the coin is in China whe=
re
these machines are used to prepare the soil with a view to planting rice. T=
he
farming organ with which the producer exports is the classic
"rotavator" or known in Spanish as a floor milling machine or sim=
ply
a milling machine, you can see its appearance in figure 5.
Graphic 5. Rotavator
with blades
Source=
: Autor y autor.
Ecuador.2018.
When the blades are designed to beat the soil in a
mixture with a humidity of 100%, the design considerations are different to=
the
conditions of tillage in Ecuador, it was designed with materials and geomet=
ry
according to its original requirement, that is why the blades They have a v=
ery
low reliability index (FI) in other working conditions, close to 0.5 in a w=
ork
day.
"The main problems are in the geometry and the materials used&q=
uot;
[8], in terms of geometry it could be said that the fastening holes become
stress concentrators, see graph 6.
Graphic 6. Stress concentrators in blades.
Fuente: Castillo-Bravo.Ecuador.2017.
After fracturing the blades of the milling machine, the residues are=
in
two parts, the first one is trapped in the milling box between two bolts and
the other part remains on the ground generating two imminent risks. The fir=
st
is the danger of cutting. sharp and sharp edges remain as can be seen in fi=
gure
7.
Graphic 7. Remains of an underground blade.
Fuente: Castillo-Bravo. Ecuador.2017.
The second danger is that in a next pass of the
machine for the place where the remains of the blades are, it can hit the
milling machine and generate more ruptures and these remains can be fired
towards the farmer.
The solution that was reached after performing both
destructive and non-destructive tests (hardness of the material, metallogra=
phy,
ultrasound, penetrating inks, simulation in CAD-CAE software) was to add
material to the critical area and was simulated in the software to know how=
was
their behavior, it was found that with the reinforcement by means of materi=
al
would not suffer, said procedure consists of two parts: a) place a piece of
commercial steel rod construction of a quarter inch in diameter convex of t=
he
blade and b) then fill it with weld bead with electrode 6011, this procedure
was chosen since it was worked in the construction of another blade in an
artisanal way but the cost benefit was low, then the exposed solution was t=
he
most viable from the point from a technological and economic point of view,
both points were very important since welding is a technology that can be u=
sed
in the middle and in terms of torque, you could use the same blades
economically and then with a reasonable investment reach a good cost-benefit
balance, you can see the new blades with the addition of material in graph =
10.
Graphic 10.
Added blades materi=
al.
Fuente:
Castillo-Bravo.Ecuador.2017.
Results.
In the first part of this section (Results of the
implementation of the Electrical System) it is important to note that
consulting various sources to verify the power range of the starter motor f=
or
the tiller system has found a work that shows table 1 [9] with the powers
required for the starter motor in relation to the size and tonnage of the
vehicle to be moved.
Table 1.
Common ranges of starting motor power.
|
Vehicle
Kind |
Potency
(CV) |
Potency
(kW) |
|
Light Vehicle |
0,5 to 1 |
0,4 to 0,8 |
|
Middle
Vehicle |
1 to 3 |
0,8 to 2,2 |
|
Heavy Vehicle |
3 to 6 |
2,2 to 5 |
Source: UTE, Ecuador.2012.
A starter has been selected after the following
deliberations: environmental conditions, protection index, installation
arrangement, nominal power, work cycles, rotation speed, efforts required to
expire; a starter motor of 3.5kW (figure 6) equivalent to approximately 4.7=
HP,
it should be noted that said engine was selected in accordance with the the=
ory
that indicates that the minimum power of a starter is equal to the sum of t=
he
power to start the thermal engine plus the power consumed by the starter, a=
lthough
this data is important is not also commercial items that are in stock,
initially selected a starter with less power and weight one of approximately
3HP but its teeth were incompatible with the cogwheel of the flywheel so th=
at
the engine of 4.7 HP was finally selected since its be=
ndix
fitted perfectly with the gear described.
The second part of this section shows the results =
of
the study of the unreliability of the blades when working in Ecuadorian soi=
l,
although in the hardness test the material had a value within the range to =
be
considered "agricultural grade" (45HRC-55HRC), however, the geome=
try
did not help as mentioned in the previous section, the specific resistance =
of
the soil was selected from the tables of the ASABE (American Society of
Agronomists and Biologists) [4] as can be seen in the table 2.
Table 2. Specific soil resistance
|
Light Floor=
|
20-30 kPa |
|
Middle Floor |
30-50 kPa |
|
Heavy Floor=
|
50-80 kPa |
Source: Ortiz-Cańavate. Espańa. 2012
With the original blades of the tiller, a deformat=
ion
of 1.9 mm is presented in the software simulation, which, extending the str=
ess
towards the stress concentrators (fixing holes), generates the fracture, as=
can
be seen in figure 11.
Gráfico 11. Simulation of the blade in normal conditions
(without adding material).
Source:
Castillo-Bravo.Ecuador.2017.
Finally, after adding mate=
rial
to the study blade as indicated in the methods section, the value of the
deformation in the most severe condition (heavy soil) is 0.25 mm; with whic=
h it
can be shown that the solution was efficient, adding to that already in the
field there were no problems and with this it was evidenced that the new
reliability index was 1.
Dis=
cussion.
The electric start system has been implemented in the tiller with wh=
ich
work accidents in the field have been completely reduced, no type of accide=
nts
or incidents of any kind have been registered in the workshops of the machi=
ning
centers. it can be asserted that the implementation has been effective.
The solution of the addition of material in the blades of the rotava=
tor
has been implemented and in the field tests carried out, no breakage has be=
en
determined so that it can be asserted that the solution was also effective,
this implies that the risk of suffering injuries for the pieces of buried
blades was eliminated.
It could be described as satisfactory results in terms of the two ca=
ses
studied, the theoretical consequences would result in the blades of the
treadmills of the model studied for import or prior to use in the country
should have a greater cross section in its convex part , it is recommended =
for
economy to add material following the described process: add a piece of
commercial metal rod and then coat it with a common weld bead; importers or
marketers of the machine are encouraged to implement the electric ignition
system.
There are no works related to the subject proposed specifically in
agricultural machinery so they can not be compa=
red or
contrasted. There are no works related to the subject proposed specifically=
in
agricultural machinery so they can not be compa=
red or
contrasted. It is indicated in the previous section, the number of tests th=
at
were carried out to validate the solutions was one English week with 8 test
hours each and one half-day rested for an average of two hours. The limitat=
ions
of the study are the following: there are many other problems in the treadm=
ill
that have only been named in this treaty but also require a solution, the
authors do not have a model of the tiller to be able to make the respective
tests, there are no statistics of the subject of the study treated.
It was tried to give the two best solutions to the main problems of =
the
described machine but in the solution of the implementation of the electric=
al
system another problem arose: the center of gravity of the tiller moved so =
it
tries to rotate forward generating in the instability driver when maneuveri=
ng.
The most relevant disadvantages at the time of giving the solutions =
were
generated in the electrical system and were the following: get commercial i=
tems
for the adaptation of parts and pieces as many parts that were used in the =
work
were old machines that spare parts are not available in stock.
The results of the present study are very valid, and clearly applica=
ble
since the respective studies were done for the two cases, no statistics have
been applied since there are no data in the subject of study and the present
writing is the solution to two specific cases of study.
This work is important because the farmers do not use the rototiller
because their blades break in the first working session, with the described
solution in addition to being economical it is practical and they will be a=
ble
to use the equipment without any doubt or danger, regarding the system
Electricity is required to work a little more in the mass transfer of the
system and in the commercialization of parts.
Conclusiones.
ˇ&nb=
sp;
The solution of the addition of material to the bl=
ades
of the tiller is effective since there was no break in the practices, it is
recommended to make an analysis of the blades in penetrating inks or magnet=
ic
particles after a month of work.
ˇ&nb=
sp;
The solution for the implementation of the electric
ignition system is effective, since the risks of knocks and bruises are com=
pletely
eliminated, it is recommended to make a dynamic analysis of the tiller as it
varies the center of mass and is generated in problems of maneuverability of
the walking tractor
ˇ&nb=
sp;
There are no data on accidents at work or the
incidence of them in the area of agricultural machinery and /=
or
related fields except for a referenced work done in the years 2011 and 2012,
and without it can not be compared with global =
data
and Latin Americans related to the issue so important to make decisions at =
the
governmental level to reduce accidents at work.
ˇ&nb=
sp;
There is not enough stock of implements to carry o=
ut
the assembly of the ignition system so that it could not be done to the ent=
ire
trellis plant in Ecuador.
=
Referencias
bibliográficas.
https://www.agricultura.gob.ec/los-centros-de-servicios-mecanizados-transf=
orman-la-agricultura/.[2].
Gomez-García,
A. (2015). Incidencia de Accidentes de Trabajo reportados en Ecuador en el
período 2011-2012. Scielo.Ciencia y Trabajo.
Ortiz-Cań=
avate.(2012). Las Máquinas Agrícolas y su Aplicación. Madri=
d,
Espańa: Ediciones Mundi-Prensa. [4].
Sánchez,J. (2016). Diseńo e Implementación de un
Sistema de arranque eléctrico para un motocultor modelo YTO DF 15l del MAGA=
P de
la provincia de Chimborazo. R<=
span
style=3D'letter-spacing:-.05pt'>ecuperado
de http://
http://dspace.espoch.edu.ec/handle/123456789/6260 =
.[5].
Aulla, A, Morejón, H. (2016). Estudio de los
factores que inciden en la baja fiabilidad del elemento de labranza de un
motocultor YTO DF 15l. Recuperado de http://dspace.espoch.edu.ec/bitstream/123456789/5630/1/65T00188.pdf
.[6]
YTO. (2000). Manual de usuario del motocultor YTO =
df 15l. China.[7].
Castillo.M,Bravo, D. (2017).Diseńo y construcció=
n de
una máquina de desgaste acelerado para homologación de maquinaria agrícola =
en
motocultores para suelos típicos de la región centro del Ecuador: caso de
estudio aspas del motocultor YTO DF-15. Recuperado
de http:// http://bibdigital.epn.=
edu.ec/handle/15000/17119.
[8].
UTE. 20=
12. Curso de Electricidad del Automo=
vil.
Estudio del Motor de Arranque. <=
/span>[En
línea] 2012. [Citado el: 26 de 01 de 2017.] http://www.stodomingo.ute.edu.ec/content/101688-153-20-2-6-17/Curso%20de%2=
0electricidad%20del%20automovil%20-%20Estudio%20del%20Motor%20de%20arranque=
.pdf
[9]
Para
citar el artículo indexado.
Castillo E., Bravo V., Abarca E., Sánchez E. &
Montúfar P. . (2018). Design and manufacture of protective el=
ements
to prevent accidents in the agricultural machinery of Ecuador, two cases of
study in automotive elements. Revista
electrónica Ciencia Digital 2(3), 193-208. Recu=
perado
desde: http://cienciadigital.org/revistacienciad=
igital2/index.php/CienciaDigital/article/view/146/131
El
artículo que se publica es de exclusiva responsabilidad de los autores y no
necesariamente reflejan el pensamiento de la Revista Ciencia Digital.
El
articulo queda en propiedad de la revista y, por tanto, su publicación parc=
ial
y/o total en otro medio tiene que ser autorizado por el director de la Revista Ciencia Digital.
[1] Escuela Superior
Politécnica de Chimborazo, Chimborazo, Ecuador, edison.castillo@espoch.edu.=
ec
[2] Escuela Superior
Politécnica de Chimborazo, Chimborazo, Ecuador, victor.bravo@espoch.edu.ec<=
/span>
[3] Escuela Superior
Politécnica de Chimborazo, Chimborazo, Ecuador, edison.abarca@espoch.edu.ec=
[4] E=
scuela
Superior Politécnica de Chimborazo, Chimborazo, Ecuador, esanchez_c@espoch.edu.ec
[5] Escuela Superior
Politécnica de Chimborazo, Chimborazo, Ecuador, esanchez_c@espoch.edu.ec
www.cienciadigital.org Vol. 2, N°3, p. 19=
3-208,
Julio - Septiembre, 2018<=
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