No 7 (2017)

Articles

The device for automatic locking of inter-wheel differential of wheeled tractor

Laubach V.P., Gerashchenko V.V., Kovalenko N.A.

Abstract

The efficient operation of the wheeled tractor is largely determined by such operating property as permeability. To increase it, the automatic interlock differential locking systems are used, which block it only when the wheeled tractor turns, and in case of rectilinear motion the differential is in the unlocked state. This reduces the permeability of the wheeled tractor in severe road conditions with its rectilinear movement. The authors propose an automatic device for locking and unlocking an inter-wheel differential operating on the basis of a generalized information parameter-the difference in the frequencies of rotation of the driving wheels of one axis when the tractor moves both in straight run and during turning. It consists of a device switch, a clutch with friction discs to lock the differential; Hydraulic actuation of its operation, consisting of a tank, a pump, a reducing valve, an electromagnetic two-position spool with a winding; two speed sensors of the first and second driving wheels; adder with two inputs and an output, inputs connected to the first and second speed sensors; amplifier output connected to the coil of the spool. When it reaches the set difference of speeds of the wheels of the drive axle is generated a control voltage which is amplified and fed to the winding spool. Moving, it ensures the inclusion of the differential lock. When the difference in the rotational speeds of the driving wheels is reduced to zero, the inter-wheel differential is automatically unlocked. The use of the developed device for automatic control of interlocking and unlocking of the inter-wheel differential, in comparison with the known, provides increased permeability of the wheeled tractor.
Tractors and Agricultural Machinery. 2017;(7):3-7
pages 3-7 views

Method for determining the displacement parameters of an agricultural mobile machine

Pavlyuk A.S., Baranov A.S.

Abstract

Technologies of precision agriculture, actively used in developed countries at the present time, lead to a significant economic effect and increase the environmental friendliness of agricultural production. The basis of high-precision agriculture is the use of satellite radio navigation systems. Satellite navigation systems provide the ability to obtain data on the characteristics of the movement of an agricultural mobile machine. Satellite navigation systems provide the ability to obtain data on the characteristics of the movement of an agricultural mobile machine. However, these data without the use of base stations do not have the accuracy sufficient to perform a number of works in agricultural production. At the same time, increasing accuracy leads to an incomparable increase in costs. The authors developed a method for determining the position of a mobile machine, which can be used for agricultural land processing. The technology provides an increase in the accuracy of determining the position of the object on the ground, as well as a reduction in the cost of equipment used for these purposes. The method is realized by means of installation on the edges of the moving sector of the agricultural mobile machine of two corner reflectors. Reflectors are equipped with individual radiation filters. The light pulse transmitter and the first type sensor are mounted on an agricultural mobile machine. The transmitter emits light in the direction of the corner reflectors. The reflected light pulse enters the receiving device and is detected by a second type sensor. After recording the reflected pulses, the time between the appearance of the primary pulse and the appearance of reflected pulses is determined. At known values of the time of appearance of pulses, the distance from the agricultural mobile machine to the angle reflectors and, accordingly, the coordinates of the machine on the plane are found. The increase in the accuracy of the data obtained is associated with a decrease in the distance traveled by pulses of electromagnetic radiation. Thus, this method is recommended to be used to improve the efficiency of seeding, inter-row crop processing, fertilization and harvesting.
Tractors and Agricultural Machinery. 2017;(7):8-12
pages 8-12 views

Modeling the operation of a screw L-shaped knife of a tiller

Dranyaev S.B., Chatkin M.N., Koryavin S.M.

Abstract

During the operation, standard L-shaped knives are exposed to various loads. The shape of the L-shaped knife blades does not meet the requirement of performing sliding cutting, which leads to an increase in the energy intensity of milling the soil. To ensure optimal cutting conditions without weed-covering and knife blocking, it is necessary that in any section of the blade (in the plane of rotation) the angle of its setting у (cutting) is constant. Therefore, the blade of the knife should be made on a screw line, which will ensure its smooth entry and sliding cutting when moving in the soil. The purpose of the study is to improve the quality and reduce the energy consumption of soil cultivation by selecting a rational angle for installing the blade and optimizing the parameters of the screwed L-shaped cutter blades. To study the work and the loading process of the screw L-shaped cutter knife, the finite element method was used from the APM FEM application library of the KOMPAS-3D system. The design of the knife was broken into elements to show their movements and deformations through the displacements of the boundary points (knots) of the element, then the nodal displacements, deformations and stresses were determined. In the course of the study, the dependence of the values of linear displacements and stress values was studied depending on the angle of installation of the knife blade (у = 35° ... 60°). The results of the study showed that as the angle of the blade was increased to у = 60 °, the total linear displacements decreased by 18 % reaching 0,6978 mm, compared to у = 35 ° (0,8455 mm) at a maximum load of 2000 N. The knife with an installation angle у = 60° has safety factor values higher than a knife with у = 35° for all load stages (500, 1000, 1500 and 2000 N). The screw knife with a large installation angle is most suitable for milling soil with slip, which is typical for sod processing. As a result of the research it was proposed to use knives with a screw working surface for milling the soil with high quality.
Tractors and Agricultural Machinery. 2017;(7):13-19
pages 13-19 views

Mathematical model of the caterpillar tractor side drive during plowing

Pozin B.M., Troyanovskaya I.P., Noskov N.K.

Abstract

The questions of the course stability of the movement of the agricultural tractor aggregate acquire the greatest urgency in the plowing, since an additional unfolding moment arises on the plow (due to the geometry of its working surfaces), which can lead the tractor aside from rectilinear motion. The tractor driver often has to correct the movement of the tractor, which contributes to its quick fatigue and, as a result, a decrease in the productivity of the work. The development of a mathematical model of the tractor's motion under the influence of an external eccentric load on the hook will allow to determine the limiting value of the shearing force. The withdrawal of the tractor under the influence of external forces (without participation from the tractor driver) is a passive turn, which currently is not paid enough attention in the theory of the curvilinear motion of the caterpillar tractor, since the theory of rotation is usually directed to the studies of active movement (under the control action of the tractor operator). The drift is a set of controlled rectilinear motion and uncontrolled shear under the action of the lateral component of force on the hook. Considering the low operating speeds of the tractor, it is possible to compile a quasistatic model of curvilinear motion during withdrawal, which consists of differential equations of motion and equilibrium conditions of external forces in the event of limiting friction. As a result of solving the system of presented equations, trajectories of the tractor's motion are obtained under different load on the hook. The developed mathematical model allows: to study the trajectory of motion on various soil backgrounds; find the optimal ratio of the weight of the tractor and the drag force on the hook; to study the influence of the parameters of the working element (the attachment point of the plow and the angle of inclination of the plow surface) on the characteristics of motion.
Tractors and Agricultural Machinery. 2017;(7):20-24
pages 20-24 views

Calculation of optimal power and energy saturation of an agricultural tractor

Samsonov V.A., Lachuga Y.F.

Abstract

Calculation of the optimum power, operating weight and energy saturation of the agricultural tractor at which the minimum fuel consumption and optimum performance are achieved is an actual task of the tractor theory. The purpose of the study is to determine the optimal power, operating weight and energy saturation of the agricultural tractor at the minimum specific energy consumption - the ratio of energy costs when processing a unit of area to the achieved productivity. Objects of research: combined arable units with wheeled and caterpillar tractors of general purpose. Initial material: nominal traction forces accepted for different traction classes; coefficients that characterize the traction-coupling properties of the tractor; the tractor's power balance equation; skidding function; computer program to minimize the function by the dichotomy method; dependences for dimensionless coefficients that take into account the increase in the specific traction resistance of the unit with an increase in operating speed. The main research method is the calculation using nonlinear programming when the energy saturation is changed by the dichotomy method. When loading with nominal tractive effort, the nominal power of a general-purpose tractor and its maximum energy saturation are determined by the specific energy costs corresponding to the operation of the arable unit with permissible operating speed and slippage. The minimum energy saturation of the tractor is determined by the ratio of the minimum operating power to the maximum operating weight of the tractor corresponding to the maximum traction efficiency. The main conclusions: the specific energy consumption of the tractor on the process operation depends on its type and the dimensionless coefficient, taking into account the increase in the specific traction resistance of the unit with increasing speed and changing in the parabola; the nominal power of the wheeled tractor is in the interval, the lower limit of which determines the minimum specific energy consumption at the maximum traction efficiency, the upper one - the specific energy consumption at the maximum permissible speed and permissible slippage; the rated power of the crawler tractor is determined by the specific energy consumption at the maximum permissible speed and permissible slippage.
Tractors and Agricultural Machinery. 2017;(7):25-31
pages 25-31 views

Investigation of viscoelastic state of soil under the influence of active surface of the tillage roller

Semenikhina Y.A.

Abstract

Universal combined tillage machines combine several processing steps. The final soil cultivation operation is performed by soil-processing machine, which works on loosened soil. Uniform compaction of the subsurface layer is able to be created by soil cultivating rollers with an active working surface. The surface of the roller, which contains elastic elements, increases the vertical load. The shock loading, characterized by intensive impact on the soil, is considered preferable. The advantage of this roller construction is the integration of external loading and automatic tuning to a rational operating mode. The study of the process of soil compaction can be carried out by analogy with the process of soil compaction. The model of the system includes the mass of the working body m, the mass of the deformed soil volume M, the soil stiffness element C, and the soil viscosity element B. The volume of soil deformed by compression is a truncated cone with a height h. Initially, there are compressive stresses in the soil volume directly at the points of contact with the working body. Then instantly, large clods of soil are destroyed, and the surface particles are displaced (compacted). Further, the crushed soil particles transfer pressure to the neighboring ones, involving more and more particles with lateral expansion. As a result of compression deformation, a compacted subsurface layer of the required density is formed. The proposed model can serve as a first approximation for further, more detailed and expanded studies of the stress-strain state of the soil with the possibility of determining the dependencies of the structural parameters and operating conditions of the soil-working compactor.
Tractors and Agricultural Machinery. 2017;(7):32-36
pages 32-36 views

Research of quality of motor fuels and oils in agricultural production of Kuban

Verbitskiy V.V.

Abstract

The quality of fuel and lubricants used in agricultural production was studied in order to assess the effect of their properties on the performance of the engine. The analysis of gasoline determined the following quality indicators: density, presence of mechanical impurities, water content, acid number, the presence of mineral acids and alkalis, fractional distillation of fuel (determination of the boiling and boiling point of 10 % of fuel, 50 % of fuel and 90 % of fuel). When analyzing the properties of diesel fuel, the following indicators of its quality were determined: density, presence of mechanical impurities, water content, flash point, viscosity at 20 °С, presence of mineral acids and alkalis. The evaluation of the quality of motor oils was carried out according to the following parameters: density, viscosity at 50 °C, viscosity at 100 °C, viscosity index, flash point, presence of mineral acids and alkalis, mechanical impurities and water, acid number. The most often deviating from the standard of quality indicators of gasoline is the density, starting properties, the propensity to form in the summer of steam plugs in the power system. Sometimes this is accompanied by incompleteness of combustion. Diesel fuels are characterized by the following violations of standard quality indicators: high content of actual resins, reduced viscosity and very high (above 100 °C) flash point. The most common indicators of the quality of motor oils, the deviation from which can lead to a malfunction of the engine, are: viscosity at 100 °C, viscosity index, acid reaction, water availability, low flash point. After assessing the quality of motor oils, the most common causes of motor malfunction were identified. Most violations of the quality of oils are associated with its improper storage or deliberate mixing with cheaper components.
Tractors and Agricultural Machinery. 2017;(7):37-42
pages 37-42 views

Evaluation of design and production of ICE

Kochenov V.A., Sakharov A.N., Kazakov S.S., Zhamalov R.R., Goeva V.V., Grishin N.E., Grunin K.E.

Abstract

It is proposed the analysis of design and production of the internal combustion engine friction units in durability and wear resistance. With a variety and dispersion of factors that determine the durability and wear resistance of the internal combustion tribome, the change in wear and wear intensity during the operation has a pronounced natural character. Evaluation of the design and manufacture of ICE is based on a comparison of the indices of durability and wear resistance of the actual and theoretical tribo-conjugation. Manufacturing tolerances reflect the potential of technical production capabilities. The design coefficient shows the correspondence of the geometry of the newly manufactured friction surface to its optimal, attained parameters. The experimental data are taken from the results of road and accelerated tests of the engines GAZ and ZMZ. Reducing wear in the run-in, design and manufacturing errors is due to improved design and lower manufacturing tolerances. Reducing the intensity of wear and increasing the operating time of parts is associated with the improvement of the material of rubbing surfaces and lubricant, and improvement of roads. The change in the design coefficient indicates that there are no pronounced trends in the design and production of the geometric parameters of the tribo-conjugate. Domestic automotive industry and engine building focused mainly on the domestic market. Design and production took into account the high demand for machines, the sparseness of the larger territory of the country, i.e. low concentration of machines in these areas and the difficulty of organizing a company service that is dependent on the number of machines in the service area. As a result, many vehicles have become uncompetitive in terms of technical characteristics, in price and reliability. The course for the modernization of the production of engines presents increased requirements for design, consisting in the full use of the technical capabilities of manufacturing and determining the prospects for their further growth.
Tractors and Agricultural Machinery. 2017;(7):43-46
pages 43-46 views

Solution of the Kolmogorov system of equations for the generalized graph of states of a mobile feed hopper

Kupreenko A.I., Isaev K.M., Mikhaylichenko S.M.

Abstract

To determine the probabilistic time for feeding animals with mobile feeders on farms of cattle, it is required to solve the system of Kolmogorov equations. Because of the massive calculations, this work can be done only with the use of computer technology. However, a specific Kolmogorov system of equations is suitable only for a certain number of components in the feed mix. Depending on the chosen feeding ration, this amount can vary significantly. Solving the Kolmogorov equations for feed mixtures with a different number of components is a very laborious process. Therefore, it is required to develop a mathematical model that allows solving the problem of determining the probabilistic feeding time for multicomponent fodder mixtures. In the course of this work, the positions of the theory of random processes, the theory of graphs, and the foundations of mathematical modeling were used. To accomplish the task, Kolmogorov's system of equations for 2-, 3-, and 4-component fodder mixtures was compiled and solved. The combinations of intensities «L» were replaced by the coefficients introduced for visual perception of formulas and the possibility to reveal the patterns of their development with a change in the number of components. The observed regularities are reflected in the algorithm. The final solution of the Kolmogorov equations is also presented, and a general formula is obtained for calculating the probability of finding a mobile feed hopper in the state of distribution of feed. The formula consists of the coefficients which are calculated according to the developed algorithm. Thus, using the proposed algorithm, there is no need to compile and solve Kolmogorov's systems of equations to determine the probability of finding a mobile feed mill in the state of distribution of food. The observed regularities are conveniently implemented in an electronic environment, for example, MS Excel, which will allow modeling of the technological process of preparation and distribution of feed mixes with a different number of components.
Tractors and Agricultural Machinery. 2017;(7):47-52
pages 47-52 views

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