Аnalytical research on determining the coefficient of use of changeover time during use of surface planning machine

ABSTRACT

The article presents theoretical attempts to determine performance of surface planning machine depending on coefficient of use of changeover time. Dependence of coefficient of use of changeover time on some factors, i.e. speed of unit movement, length of field working sections and time spent on elimination of technical defects is given.

АННОТАЦИЯ

В статье представлены теоретические попытки определения производительности планировщика в зависимости от коэффициента использования времени смены. Дано зависимость коэффициента использования времени смены на некоторых факторов: скорость движения агрегата, длина рабочих участков поля и затраты времени на устранение технических неисправностей.

Keywords: changeover time, length of working stroke and grasp width, translational working speed of the planning unit, operative time of changing the tractive power of the tractor, specific soil resistance

Ключевые слова: время смены, длина рабочего хода и ширина захвата, поступательная рабочая скорость планировочного агрегата, оперативное время смены тяговой мощности трактора,  удельное сопротивления почвы

World and domestic farming practices have proved that planning or leveling field surfaces are the main reclamation measure aimed to eliminate the roughness in the form of various heights and lowlands in the sown areas.

Planning of the land surface creates the basis on which irrigated agriculture can develop properly with a steady increase in crop yields [1, 2,3].

Planning of the land is an integral operation, both in reclamation and agricultural production. It is one of the effective agricultural measures ensuring increase of yield of all agricultural crops, reduction of water consumption during irrigation and improvement of working conditions during subsequent operation of agricultural machinery. As known, irrigation farming is based on surface watering methods that require careful planning. During operation, the surface of the earth is subjected to deformations under the influence of various factors, which must be eliminated by the so-called operational planning.

Long-phase planners of various brands and modifications are widely used for its implementation. The performance and quality of the planning unit mainly depends on the speed of movement, the length of the run of the section and the correct selection of the movement scheme.

As we know, the maximum productivity of long-base planners depends on the speed of movement, the grasp width of the unit, the length of run, the specific resistivity of the soil and the tractive power of tractor.

The performance of the long-base planner per hour of changeover time is less than the theoretical productivity and depends on the total coefficient of use of changeover time. [1, 4]

The amount of coefficient of use of changeover time is influenced by many factors, the main of which are:

- speed of unit movement, length of working sections of field, time spent on elimination of technical defects, etc.

In order to consider the impact of these factors, we will express the coefficient of use of changeover time through the net operation time Т_р and the total time Т_га to the assigned hectare of treated area. i.e:

                                                                      (1)

The net operation time is determined as:

                                                          (2)

where, W_m- theoretical productivity per hour of net operation, ha / hour.

The total treatment time of one ha (Т_га) can be expressed as:

                                                             (3)

where Т_{оп га} - operational time for processing 1 ha/hour:

Т_см – changeover time, hour;

Т_оп – operative changeover time, hour.

Time Т_{оп га} is determined as:

Т_{оп га} = Т _{р га} + Т _{пов га}+ Т _{пер га}+ Т _{то га}                                                  (4)

Here Т _р , Т _пов , Т _пер  – accordingly, the elements of the time spent on processing 1 ha of operational time, turnover time, movement time and maintenance. The operational changeover time is determined as:

Т _роп = Т _см – (Т _то+ Т _физ)                                                  (5)

where Т_то, Т_физ - time during the changeover spent on maintenance and physiological needs, which are not directly dependent on the area being processed. [4, 5]

After substituting in equation (1) the values coming from equation (2) and (3), we obtain:

By replacing the incoming values with their values from equations (4) and (5) we have:

                                  (6)

In the obtained equation, the time Т_{р га} is determined by equation (2). And time of turns Т_{пов га} per one ha can be expressed by the time of one turn t_noв, grasp width B and length of working stroke L by the following dependence:

In this case the equation (6) has the following form:

After the conversion, the resulting equation will slightly change:

                                        (7)

where - coefficients taking into account the time spent on maintenance and physiological needs during changeover [3].

Т_то and Т_физ – proportional durations of the changeover.

V - progressive working speed of the planning unit, km/h;

t_noв - duration of one turn, sec;

L, В- length of working stroke and grasp width, m;

Т_перга - travel time per one ha, sec.

The analysis of works /6/ shows that along with the main parameters of the long-base planner, the volume of work performed during the season (year) can affect the effectiveness of its use. Aggregates with a large grasp width at a small annual load can be less economically efficient relative to units with a smaller grasp width. Thereby, the selection of economically optimal parameters of a long-base planner requires a comprehensive approach, which will be considered in the subsequent part of this section.

References:

1. Norov, S. N., Abrorov, A. S., Hamroeva, M. F., Muxamedjanova, S. F., & Zaripov, G. B. (2020). Research of the screw working element working jointly with the planner’s bucket. Journal of Physics: Conference Series, 1515(4). https://doi.org/10.1088/1742-6596/1515/4/042016
2. Khasanov I.S. et al. “Theoretical preconditions for determining some parameters of the screw working jointly with the planner bucket”. Journal “Agrarian science”, Moscow, 2015
3. Norov S.N., Hamraeva M.F. Analytical research of determining the maximum efficiency of planning machines. International Journal of Advanced Research in Science, Engineering and Technology Vol. 6, Issue 6, June 2019 361-362 p.
4. . Norov S.N «Research and development of a machine system for complex mechanization of precultival treatment of agricultural conditions in the bukhara region» Монография “Lambert Akademic Publishing”  Germaniya 2019. ISBN 978-620-0-22740-9
5. Vasiliev B.A. et al. “Land reclamation machines”. Moscow, “Kolos”, 1980
6. Khikmatov P.G. “Research of qualitative and technological performance indicators of the long-base planner in order to substantiate the optimal grasp width and movement speed”. Abstract for the candidate of technical sciences. Tashkent, 1978