No 8 (2016)

Articles

Development of combined working organ for graded subsurface tillage

Bozhko I.V., Parkhomenko G.G., Gromakov A.V., Kambulov S.I., Rykov V.B.

Abstract

Nowadays the trend of development of combined units and devices for implementation of specified technological processes is widely spread. The use of combined working organs for graded subsurface tillage allows to reduce the energy and labor costs and to improve the technological process. Based on the comparison methods and monographic survey of existing designs of working organs, their shortcomings when using in arid conditions are revealed. It has been established that in such conditions it is advisable to apply graded subsurface tillage. The analysis of designs of working organs for graded tillage is performed, it allows to establish the advantage of curved elements for surface tillage. A number of shortcomings of subsurface cultivating working organs that have been revealed during years of researches allows for the conclusion about the prospects of replacing blades on curvilinear rippers for surface tillage. The data of content of valuable soil aggregates as a percentage of absolute dry chernozemic soil are given. Based on the analysis of the data, it is established that layer structure can be improved through the use of an element for surface tillage to the depth down to 16 cm in design of chisel working organ. The expediency of mounting of elements for deep and surface tillage on the same tine for graded subsurface tillage is proved. The scheme of a combined working organ is proposed: a chisel for deep tillage and a curvilinear ripper for surface tillage are mounted on its tine, which provides the required crumbling of layer.
Tractors and Agricultural Machinery. 2016;(8):3-6
pages 3-6 views

New means of mechanization for fruit-tree nurseries in mountain and foothill areas of the North Caucasus

Dzhibilov S.M., Gulueva L.R., Bestaev S.G., Poraeva Z.K.

Abstract

The article describes the present state of mechanization of horticulture and fruit-tree nursery, analyses the mechanization of technological process of parent bushes hilling. Production of planting material for establishing new type orchards depends on the degree of mechanization of technological processes in fruit-tree nurseries, more specifically on the availability of special equipment for work in mountain and foothill areas on stony and heavy soils. At this stage, the urgent task is to increase the efficiency of work of fruit-tree nurseries with simultaneous reduction of labour and power intensity by means of mechanization of production processes based on new technologies and technical tools for cultivation of planting material. The new type orchards, as a rule, are short-growing, high-yielding and require a 5-6 times bigger planting stock compared to old type orchards. Therefore, it is necessary to intensify the production of transplants in fruit-tree nurseries of a new type, and to lay for it the industrial foundation with the use of mechanization means for the care of parent bushes. This intensification is only possible on the basis of application of modern industrial technologies of reproduction of planting material taking into account the landscapes of the Republic of North Ossetia - Alania and the use of high-performance agricultural machinery, tractors and other equipment. The article proposes a technology and a combined unit for parent bushes hilling and row spacing cultivation, as well as a tent for budding of planting stock of fruit and berry crops when establishing the new orchards up to world standards. These devices allow to increase labour productivity under production of planting stock in conditions of mountain and foothill areas.
Tractors and Agricultural Machinery. 2016;(8):6-9
pages 6-9 views

Loading of tractor on drawbar test when pulling force is directed at the angle

Gorodetskiy K.I., Lavlinskiy A.M., Alendeev E.M.

Abstract

Foreign methods of tractor drawbar testing do not allow to evaluate the performance capabilities of movers and drive system in general with a number of other common characteristics, because of using a tar makadam as a surfacing. Methods of tractor testing used in Russia provide the experiments on real soils and aiming to a wide variety of the country's natural environments. But even these tests do not give a full picture of performance of a machine-tractor unit. Tractor is a multipurpose machine that aggregates with a variety of implements that have a wide range of draught resistance. Therefore, during aggregation it is necessary to load tractor’s axles efficiently. Tractor ballasting increases the rolling resistance force that affects negatively on the propulsive efficiency. In most cases, the front ballast is not removed and remains on a tractor permanently, which increases the fuel consumption. There is a search problem for technical solutions that would optimize the tractor performance without using front ballast. For solving this problem, it is proposed to improve the methods of drawbar testing by directing of pulling force at the angle. If this angle is controlled, it is possible to load a front axle without ballast. In this case, the rear axle is loaded, and its trailing weight is decreased. Additional loading of the rear axle is adjusted by adding ballast weights to the rear wheels or on a cross bar of lower arms. For each case of loading by pulling force, it is necessary to provide the proper rational weight distribution to achieve the highest propulsive efficiency.
Tractors and Agricultural Machinery. 2016;(8):10-14
pages 10-14 views

Simulation of the formation of vibration loading of operator workplace of industrial tractor

Berezin I.Y., Pronina Y.O., Bondar' V.N., Vershinskiy L.V., Taranenko P.A.

Abstract

The check of compliance with legislative requirements for vibration protection of operators is carried out at the stage of certification testing of new and upgrading products. At this stage, the further development is associated with high time and material costs. The article substantiates the possibility of use of a calculation and experimental method which allows to determine at the development stage the level and frequency content of potentially dangerous sources of vibration; to develop a computer model for the system «excitation source - frame - cab - antivibration seat - operator»; to make out proposals to comply with legislative requirements by means of parametric forecasting. As an example, the problem of vibration in the low frequency range of 2-14 Hz is considered. This vibration is the result of the process of rolling of track rollers on track chain that lies on the yieldable soil foundation. According to biomedical research, the resonance frequencies of critical parts of human body are in this low frequency range, which is displayed in sanitary norms. Based on the analysis of field test results, the kinematic impact of track rollers on tractor frame is represented as stationary narrow-band random processes. Mathematical model of the system is described by a set of differential equations with random input processes. The methods of statistical dynamics are used to implement the model. The simulation results are presented as a set of transfer functions. They represent the distribution of resonance frequencies of angular and heave oscillations of the separate system elements and the spectral density functions. These results allow to obtain the quantitative estimations in the form of mean-square values of the output processes. The use of this approach allows to solve the problems of vibration protection of operator at the stages of design and testing of prototypes of road-building machinery. It is achieved by tuning-out of the system «track assembly - frame - cab - antivibration seat» from resonance phenomena and by introducing some design solutions.
Tractors and Agricultural Machinery. 2016;(8):14-18
pages 14-18 views

Basics of safe drying of seeds

Golubkovich A.V.

Abstract

In seed-production farms, the temperature of drying agent is often limited by the maximum permissible temperature of heating; the simultaneous moisture removal is 3-6%; seeds are dried to a moisture content that exceeds the normal one by 2-3%; the layer is stirred several times during drying process. All of this increases the process cost and could lead to crop losses. The paper analyzes the essential factors influencing the safe drying of seeds in dense layer. It is found that along with the maximum permissible temperature of heating, account must be taken of the rate of dehydration, the specific surface of seeds, the heat transfer coefficient and the unevenness of moisture of basic material and of a dried-up one. The estimation of parameters for safe drying of seeds is carried out on the basis of mathematical models and well-known empirical expressions of the heat resistance and maximum permissible moisture removal. The article proposes the calculation of drying agent temperature that ensures the complete safety of the process, for breeder seeds also. Permissible temperature of drying agent is calculated by the expression that takes into account the specific surface of grain, the heat transfer coefficient, the heat of vaporization and the coefficient that depends on the permissible rate of dehydration, as well as the maximum permissible temperature of seeds heating. The maximum height of the layer of seeds being dried without stirring depends on the speed of drying agent, the diameter of grain, the porosity of layer, the mass transfer coefficient and the moisture content of drying agent before and after the layer. The maximum permissible temperature of seeds heating should be calculated according to the formula of S.D. Ptitsyn, but the maximum humidity of 10% of weighed portion should be used as a basis.
Tractors and Agricultural Machinery. 2016;(8):19-22
pages 19-22 views

Influence of the shape of disk knife on the pinching of material

Kobyakov I.D., Evchenko A.V., Demchuk E.V.

Abstract

During the primary cultivation by means of general-purpose ploughs, the circular disk knives do not provide a reliable cutting; with that, the traction resistance of plough is increased, productivity and quality of its work are reduced. The purpose of the research is to increase the operational efficiency, the quality of soil cultivation and to reduce the energy intensity of general-purpose ploughs equipped with disc knives. Different designs of knives are studied in order to find the optimal shape providing a reliable pinching of plant and straw mass. A formula for determining the angle of pinching of a polygonal disc depending on the cultivation depth and number of angles in the polygon is given. The studies show that the hexagonal disk knives have the minimum angle of pinching, thus this shape is rational. The operating conditions are defined, in which the stalks of straw mass do not slip out of the knife blade when cutting. Motion paths of blades of hexagonal and circular knives at different positions of the instantaneous center of disk rotation are studied graphically. An empirical formula is obtained; dependences of pinching coefficient on the position of instantaneous center of disk rotation are constructed. It is found that with decreasing of nominal diameter of a knife the pinching coefficient is increased, and the quality of pinching of crop materials is improved. As a result of the research, the dependences are obtained showing that the areas of reliable pinching and cutting linearly depend on the kinematic parameter. With the cultivation depth of 0.08-0.12 m, the efficiency of pinching of hexagonal knife is increased by 1.8-2 times compared to the circular one.
Tractors and Agricultural Machinery. 2016;(8):22-26
pages 22-26 views

Assessment of model adequacy of the process of grain impurities separation from the fraction of light waste in settling chamber to experimental results

Saitov V.E., Suvorov A.N.

Abstract

The fullest utilization of harvested grain is an important task of agricultural production. During separation of seed grain from grain heap a large amount of grain impurities (feeble and crushed grain) being a valuable animal feed is lost. One of the effective methods of separation of grain impurities from light waste is the fractionation on aerodynamic properties. When developing and improving the devices for fractionation of light waste by means of airflow, it is necessary to carry out a large number of experiments, which is associated with time, energy and material consumption. Mathematical modeling allows to minimize the number of experiments. Before applying a mathematical model in designing of technical devices, it is necessary to assess its adequacy. The article presents the assessment of adequacy of the results of mathematical modeling of light waste fractionation process to the experimental results. Qualitative assessment of adequacy is carried out by determining whether the results of mathematical modeling are within the tolerance range of experimental data; quantitative assessment is carried out by means of statistical hypotheses testing. The results of theoretical calculations draw one sample, the results of experiments draw another. Two statistical hypotheses are considered. Each of the hypotheses is tested at 0.05 of significance level. The hypothesis that both of received samples belong to the same parent population is tested with the use of the sign test. As a result of research, the hypothesis is accepted on the selected significance level. Then a regression model is developed for each of the samples, and using the Chow test the hypothesis about the coincidence of constructed regression models is tested. As a result of research, the second hypothesis is also accepted at 0.05 of significance level. The considered mathematical model can be used in the design of technical devices for fractionation of light waste.
Tractors and Agricultural Machinery. 2016;(8):26-29
pages 26-29 views

Mitigation of effect of compacted soil lump

Sidorov S.A., Khoroshenkov V.K., Mironov D.A., Luzhnova E.S.

Abstract

The article shows the effect of compacted soil lump which forms on the blade and in front of it on the characteristics of performance and lifetime of soil cutting working organs. Facts proving the presence of compacted soil lump on the blade in process of cutting soil layer are given. The results of theoretical and experimental researches are brought, allowing to obtain the design parameters and to improve the technical level of working organs used in soil cultivating and cutting. Negative factors that affect the efficiency of parts of tillage equipment in the conditions of compacted soil lump effect are substantiated and listed. The cyclical nature of its formation on the blade cutting the soil layer is noted. The article presents a hypothetical scheme of soil lump effect on the blade of working organ with different degrees of bluntness. This scheme explains the physical meaning of negative effects that are associated with deterioration of energy and agronomic indicators of parts and equipment during the operating wear in conditions of clear-cut compacted soil lump (on relatively strong soils). The article determines the fundamental reasons for the sharp increase in resistance of soil in the presence of chamfered edge on the blade of cutting working organ, which is associated with movement of compacted soil lump under the blade. Regularities defining the values of specific loads acting on the blade are given. The differences in variation of total and specific loads on working organ under formation of compacted soil lump are noted. The article substantiates a special role of the rear face of the blade of working organ in connection with heavy conditions of loading of soil layer under it. It describes the practical design and technological methods of protection of parts against the effects of compacted soil lump. Substantiated values of the parameters of working organs of agricultural machines interacting with soil are given, that provide the increase in their operational, agronomic and life characteristics.
Tractors and Agricultural Machinery. 2016;(8):30-32
pages 30-32 views

Study and calculation of soil compaction during operation and after stopping of a wheeled tractor

Zolotarevskaya D.I.

Abstract

Based on the results of theoretical studies and field tests, the mathematical modeling is performed for the processes of soil deformation and compaction during operation and after stopping of a wheeled tractor. The purpose of the study is to develop the earlier proposed calculating method of stress-strain state and soil compaction indicators during the operation of tractor and under soil creep after its stopping. The novelty of the paper consists in the fact that calculations are performed taking into account the viscoelastic properties of soil and changes of its density depending on time and on depth of deformable layer. The impact of soil load taking into account the viscoelastic properties of soil is described by a differential equation of first order connecting the compressive stresses, the rate of their change and relative deformations of compression. Viscoelastic properties of sward-podzolic light loamy soil revealed in field tests are considered. Soil density is variable by depth of its top deformable layer. Following the results of statistical processing of experimental data, the dependence of soil density on its depth before the impact of external loads is admitted as quadratic one. Computer experiments are performed; they revealed the indicators allowing to estimate quantitatively the changes of soil deformations, stresses and density during the operation of tractor and under soil creep after its stopping. Correlation dependencies of these indicators on the time, soil density and moisture, and on the speed of initial soil deformation are obtained. The proposed calculation method allows to find the above mentioned indicators for different depths of deformable soil layer, and also the stabilization time of soil deformation.
Tractors and Agricultural Machinery. 2016;(8):33-38
pages 33-38 views

Strategy for design improvement of a combine harvester

Ozherel'ev V.N., Nikitin V.V.

Abstract

Promising directions of design improvement of combine harvester by means of the maximal adaptation of algorithm of its impact on plants with different physical and mechanical properties are presented. The technological algorithm of work with grain heap is optimized. It is proposed to separate previously the light impurities directly in the stripper header, the rear wall of which should be equipped with inertial tilted-plate separator. The light impurities are removed along with excessive airflow from the stripper header, but heavier free grain and tailings remain inside. In the terms of design, such technical effect is achieved due to the fact that the separator is formed by a set of longitudinal plates mounted with overlapping and imbedding of greater part of the cross section of each of them into the body of stripper header. The cross section of the plate has a curved surface, and its concavity is oriented towards the rear wall of the body. Remaining grain heap (tailings and free grain) is subjected to the secondary separation on perforated bottom of grain conveyor. Elongated holes are made in bottom; they have a particular cross-sectional shape and are inclined from the motion direction of conveyor flights on acute angle. As a result, the awns of spikes do not catch hold of the rear edge of the hole, and climb up the angled surface to the level of bottom of grain conveyor. Implementation of set of these technical solutions in the design of modern combine harvester will increase its performance when stripping of standing plants with eliminating the possibility of free grain crushing by working organs of the threshing device.
Tractors and Agricultural Machinery. 2016;(8):39-43
pages 39-43 views

Analysis of design quality of tillage machines for agricultural engineering small-scale mechanization means of 0.2 tractive class

Devyanin S.N., Sapozhnikov I.I., Shmonin V.A.

Abstract

Such operational parameters of small-scale mechanization means as grasp width and motion speed of a unit equally affect the machine performance and thereby determine its complex quality. The improvement of machine performance due to the extension of grasp width is reached by the use of three-, five-, six- and eight-furrow ploughs. This direction requires the constant increasing of traction force of power vehicles due to the increasing of engine power and trailing weight, which finally change the operational qualities of machine. Other direction of performance improvement is due to the increasing of operation speed; it is more complicated because when the speed increases, the traction resistance of working organs of tillage machines rises sharply, and the quality indicators of ploughed soil structure worsen. The transition to higher speeds of tillage requires a complex solution of such scientific and technical problem as development, creation and introduction of essentially new tillage machines for small-scale mechanization means. Special attention should be payed to a method for improvement of the engine power use by means of its transferring to working organs of the machine not through a hook but through a power shaft. Soil reaction to the active working organs is directed towards the power vehicle motion, therefore the trailing weight loses its functional necessity. It will allow to reduce the metal consumption of construction of small-scale mechanization means.
Tractors and Agricultural Machinery. 2016;(8):44-47
pages 44-47 views

Increasing the calorific value of motor fuels

Vorob'ev Y.V., Dunaev A.V.

Abstract

The results of the studies of mechanochemical activation of motor fuels aimed to increase their calorific value and reduce their consumption in automotive internal combustion engines are summarized. Traditionally, the improvement in fuel efficiency and environmental friendliness of such engines is achieved by high-tech modernization of fuel systems. But it can also be achieved by modification of fuels that changes their properties and increases the calorific value. By means of methods of mechanochemistry, using the equipment with low power consumption and a simple process, the mixtures and separate oil fractions are destroyed with the formation of low molecular homologs, as well as hydrogen and carbon. The degradation of saturated hydrocarbons is the breaking of chains, and unsaturated ones are destroyed through the formation of saturated products. The hydrogenation by degradation products of the starting material is possible. The mechanochemistry of fuels is investigated on the example of a combined static mixer-activator. The activator in the form of cylinder of 150 mm length and 30-50 mm diameter is used for modifying motor fuels; it has three serial camera, embeds in any of the fuel systems of internal combustion engine, does not require the drive, is free of chemical substances, does not affect the performance of gasoline, diesel fuel, aviation kerosene, fuel oil, does not reduce the engine lifetime. The tests were performed on a test bench with YaMZ-236 diesel engine using three different diesel fuels, at first with installation of activator in the fuel supply line of fuel high pressure pump, and then in its main drain line. When idling of diesel engine with engine speed of 900-1300 rpm, the reduction of activated fuel consumption on average by 26.3% is revealed in eleven tests. The methods for improving the calorific value of fuels by different impacts are reviewed.
Tractors and Agricultural Machinery. 2016;(8):48-51
pages 48-51 views

Gold medalists of AGROSALON Innovation contest

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Tractors and Agricultural Machinery. 2016;(8):52
pages 52 views

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