Justification of the Coefficient of Use of the Working Time of the Unit Change for Harrowing Winter Crops with Simultaneous Top Dressing

The dependences of the coefficient of use of the working time of the change of the proposed multifunctional unit for harrowing winter crops with simultaneous additional fertilizing with solid mineral fertilizers are theoretically justified. In the conditions of agriculture of Krasnodar Territory, with an increase in the working speed of the unit, a significant decrease in this coefficient was found for various ruts and capacities of the fertilizer silo. For the proposed unit, all components of the cycle time spent on performing two working and two idle passes through the field with the shuttle method of movement, as well as the number of cycles per shift, the actual duration of the shift time and its utilization rate are calculated. With an increase in the working speed of the unit, all other things being equal, the value of the shift time coefficient decreases. 1 Material and methods of research In order to achieve an increase in grain yield, it is necessary to improve the system and methods of tillage, use the most advanced machines. These include multifunctional units (MFUs) and machines. The use of such units and machines will allow the most rational use of capabilities of tractors with constant limits of the working width and working speed [1]. The simplest solution for creating such a MFU and combining several operations into one is to connect two or more single operating tools in a sequence that corresponds to the technological process [2]. If it is necessary, each of its machines can be used as an independent one to perform a specific operation. It is also possible to create a multifunctional unit in another way by placing several working bodies to perform a certain number of technological operations on one common frame [3, 4]. 2 Results of research We have proposed a new multifunctional unit that combines the operations of fertilizing and simultaneous harrowing of crops [5]. The dependence of the coefficient of time change * Corresponding author: sasha2008_9191@mail.ru MATEC Web of Conferences 346, 03005 (2021) ICMTMTE 2021 https://doi.org/10.1051/matecconf /202134603005 © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/). use of the multifunctional unit on its work is necessary to calculate the productivity of such a unit and the need for them (for example: the size of fields, the capacity of the fertilizer hopper), taking into account the change in the working speed, which determines the purpose of this article. 2 p оc rp t t n = , (1) where оc t – time spent on technological stops of the unit per cycle, h; p t – duration of stop for filling the tank of the fertilizer hopper, h; 0,064h p t = . rp n – the number of working passes from refueling to filling the machine with fertilizers. 4 10 b рп ag r V n НB L λρ = , (2) where b V – capacity of the fertilizing hopper, m3; λ – degree of hopper’s filling ( 0,85 0,90 λ = − ); ρ – density of fertilizers, kg/m3 890 ρ = kg/m3; Н – fertilizer application rate, kg/hа; ag B – width of the unit's gripping, m; r L – rut’s length, m. Substituting the obtained data from formula (2) into formula (1), we get: 4 4 2 0,064 35 4,5 10 0,67 890 10 596 ag r ag r оc b b B L B L t V V ⋅ ⋅ ⋅ ⋅ ⋅ ⋅ = = ⋅ ⋅ ⋅ ⋅ ⋅ , (3) The cycle time c t is also determined by the well-known dependence [6]: c оc rc hc t t t t = + + , (4) where , rc hc t t – the time taken for the units to perform two working and two idle passes through the field, respectively, h; 2 1000 r rc r L t V = и 2 1000 h hc h l t V = , (5) where r V and h V – accordingly, the operating speed of the unit and the idle speed, km/h (when working with one mounted device 5 h V = km/h) [6]; h l – idling length of the unit, km. For the shuttle mode of movement h l , it is determined by [6]: 6 2 h l R е = + , (6) where R – the radius of the unit’s turn, m; е – length of the unit movement, m, including the kinematic length of the tractor (for MTZ-80 in our case 1,2 Т l = m) and the unit ( 1,0 m l = m). So, 2, 2 Т m е l l = + = m. R аг R K B = ⋅ , (7) where КR – coefficient for calculation of the radius of turn of the unit, (КR = 1,0) [6]. Now from formulas 6 and 7 it follows: 6,0 1,0 2 2,2 6 4,4 h ag ag l B B = ⋅ ⋅ + ⋅ = + , MATEC Web of Conferences 346, 03005 (2021) ICMTMTE 2021 https://doi.org/10.1051/matecconf /202134603005


Material and methods of research
In order to achieve an increase in grain yield, it is necessary to improve the system and methods of tillage, use the most advanced machines. These include multifunctional units (MFUs) and machines. The use of such units and machines will allow the most rational use of capabilities of tractors with constant limits of the working width and working speed [1]. The simplest solution for creating such a MFU and combining several operations into one is to connect two or more single operating tools in a sequence that corresponds to the technological process [2]. If it is necessary, each of its machines can be used as an independent one to perform a specific operation. It is also possible to create a multifunctional unit in another way by placing several working bodies to perform a certain number of technological operations on one common frame [3,4].

Results of research
We have proposed a new multifunctional unit that combines the operations of fertilizing and simultaneous harrowing of crops [5]. The dependence of the coefficient of time change use of the multifunctional unit on its work is necessary to calculate the productivity of such a unit and the need for them (for example: the size of fields, the capacity of the fertilizer hopper), taking into account the change in the working speed, which determines the purpose of this article.
where оc t -time spent on technological stops of the unit per cycle, h; p t -duration of stop for filling the tank of the fertilizer hopper, h; 0, 064h rp n -the number of working passes from refueling to filling the machine with fertilizers.
The cycle time c t is also determined by the well-known dependence [6]: where , rc hc t t -the time taken for the units to perform two working and two idle passes through the field, respectively, h; 2 1000 where r V and h V -accordingly, the operating speed of the unit and the idle speed, km/h (when working with one mounted device 5 h l -idling length of the unit, km. For the shuttle mode of movement h l , it is determined by [6]: R аг where К R -coefficient for calculation of the radius of turn of the unit, (К R = 1,0) [6]. Now from formulas 6 and 7 it follows: 6, 0 1, 0 The number of cycles per shift (7 hours) is determined by: The actual duration of the shift time is: In Fig. 1, 2, 3, the theoretical dependences of the utilization factor τ of the MFU shift time on the working speed of the unit movement at different values of the hopper volume and the length of the rut for a rotary hoe with a grip of 6.7 m are constructed.

Conclusion
As a result of obtained dependences, it was found that the values of the utilization factor of the working time of the MFU shift for the MTZ-80+MRN-6 unit vary in the range τ = 0.59-0.80 with the length of the rut of 500-1500 m with the hopper b V = 0,7 m 3 , with the length of the rut of 1000 m depending on the capacity of the hopper 0.5-0.9 m 3 τ varies in the range of 0.66-0.79, and with the length of the rut of 1000 m depending on the width of the gripτ , it changes in the range of 0.49-0.80.