No 9 (2017)

Articles

Fuel systems for feeding mixed fuels in high-speed diesel engines

Mal'chuk V.I., Dunin A.Y., Alekseev I.V., Trofimenko Y.V., Kalinina S.M.

Abstract

The article presents the results of the assembly and testing of the fuel system variants developed at the Moscow State Automobile and Road Technical University for the supply of mixed fuel with the possibility of changing their composition during the injection process. The nozzle housing for mixed fuel differs from the housing of the serial product by the presence of two channels for supplying to the atomizer, respectively, the main fuel and additive. The nozzle is equipped with a sprayer, which also has channels for supplying diesel and alternative fuels. The supply of diesel fuel through the axial channel in the nozzle of the nebulizer is also of fundamental importance, since it inevitably falls into the gap between the needle and the body and thereby facilitates the lubrication of this precision pair. Mixing of the components of the mixture is carried out in the cavity located at the base of the locking cone of the needle. This is another principal feature of the nozzle atomizer design, intended for mixed fuel. Motor fuel mixture research was carried out on a single-cylinder engine mounted on the universal crate of IT-9 (1 Ch 10.5 / 12). It is shown that an increase in the proportion of water in a mixture with diesel fuel leads to an improvement in the composition of combustion products in diesel. Thus, with a 50 % water content, carbon emissions are reduced by almost 10 times, nitrogen oxides by a factor of 2,6, and carbon oxide by a factor of 2,5. The working capacity of the development during its operation as a part of the diesel engine (2 Ch × 10.5 / 12) is shown and the possibility of improving its ecological characteristics with a reduction in the consumption of diesel fuel by partial replacement with ethanol is demonstrated.
Tractors and Agricultural Machinery. 2017;(9):3-10
pages 3-10 views

Methodology for the development of agricultural modular aggregates

Dmitrenko A.I., Bur'yanov A.I., Goryachev Y.O.

Abstract

The territories of agricultural regions of Russia are subdivided into subzones with different climatic and soil conditions, crop rotations and technologies, annual volumes and terms of work that determine the structure and composition of machine and tractor parks. In the designs of traditional technical means, as they were improved, the application of science and technology achievements was increased, ensuring an increase in the productivity of machines with a faster growth in their prices. An increase in the annual load of modern mobile energy facilities, which could significantly reduce the cost of their work, is limited by the agrotechnical timing of their implementation. Obviously, one of the ways to improve the efficiency of technical means is to combine the functions performed by different types of machines, for example, tractor and harvesting machines in one unit based on the power tool. Implementing the potential of such units will not always succeed. This is possible only if the periods of peak loads of machines for different purposes do not coincide, taking into account the specific functioning of the machine and tractor fleet of the agricultural enterprise of a certain type of activity in a particular region. At the same time, in addition to solving traditional tasks related to the development of constructive and technological circuits for mobile power equipment of a new generation with sets of replaceable adapter modules, a whole series of new problems arise, for the solution of which it is necessary to develop a set of methods for their implementation or methodology. The subject of the article's research is the methodology for the development of modular aggregates based on frame and replacement technological systems for agricultural enterprises taking into account the specifics of the current market and zonal conditions. The purpose of the study is to systematize and disclose methodological aspects of the development of modular aggregates for machine and tractor parks. The use of modular aggregates on the example of one model of an agricultural enterprise will ensure a reduction of capital investments in the machine and tractor fleet and operating costs for its maintenance by more than 17 and 14 % respectively, while a simultaneous increase in net discounted income by more than 53 %.
Tractors and Agricultural Machinery. 2017;(9):11-21
pages 11-21 views

The rationale for the curvilinear shape of the working body for layered subsurface tillage

Parkhomenko G.G., Bozhko I.V., Gromakov A.V.

Abstract

The larger the cross-sectional area of the formation can be processed in a single pass, the less energy is needed to carry out the process. The cross-sectional area of the treated formation is determined by the perimeter of the working body. The circle of all figures of equal perimeter has the largest area. It is advisable to make the working organ ring-shaped. When designing a ring on the plane of the smallest cutting force, an ellipse is formed. From the point of view of physical mathematics, the ellipse is the best curve possessing the minimum property. The optimal shape of the working body is an elliptical ring. The parameter of the ellipse corresponds to the angle of soil displacement in the longitudinal-vertical plane. The elliptical working body carries out the crumbling and separation of the layer with the removal of more solid macroaggregates of soil on the surface and the erosion-hazardous particles that remain inside the formation in the gap between them. Stresses on the working body are determined by interaction with the soil. On the base of the ellipse, the normal stress caused by the backing of the soil layer acts, and the pressure of the cutting edges of the working body affects the cylindrical surfaces. The intensity of stresses arising on the surface of the cylinder is determined on the internal crack of an elliptical shape located in a solid body under the action of a load. The greatest intensity of stresses is localized at the ends of the minor axis of the ellipse, and the smallest at the ends of the major axis. As the cracking angle increases, the stress intensity increases, and then decreases. With an elliptical shape of the working element, the stress intensity zone is wider than that of the circular cutting edge, while deformation of stretching and bending is created in the zone of lateral rounding, which is absent in the plane, and the traction resistance is reduced by 0,5 ... 1,3 kN. The degree of crumbling of elliptical working organs is 87,1 ... 98,5 % of fractions up to 50 mm, combing 1 ... 2 cm, reduction of erosion-hazardous particles 15...22 %.
Tractors and Agricultural Machinery. 2017;(9):22-30
pages 22-30 views

The characteristic of innovations of working bodies for sowing in technology of soil-free tillage and sowing

Bespamyatnova N.M., Bespamyatnov Y.A., Kolin'ko A.A.

Abstract

The science-intensive resource-saving technology of sowing seeds of various agricultural crops with simultaneous non-contact application of seeds and fertilizers in conditions of insufficient moistening with the use of created controlled system blocks to sowing and tillage machines and aggregates has been developed. Seeds and fertilizers are placed at different depths of the embankment with the creation of a compacted soil bed for seeds, performed in the subsoil horizon in accordance with agrotechnical requirements. To reduce energy processes in soil cultivating and sowing machines, electrical or electronic analogs are introduced or completely replaced in mechanical devices, control of which is provided by subsystems of frequency control of working processes adapted to the properties of seeds and the conditions of operation of the units. In the process of sowing, the seeds, fertilizer and prepared seedbed with the given agro-technical conditions are exposed to a frequency field that changes both the boundary and the bulk forces that arise in the modes of technological processes. The working hypothesis is taken that the uniformity of the simultaneous sowing of seeds and fertilizers with different sowing rates can be achieved by bringing the density of materials to the identical view in the field of vibration, providing a stable flow of velocity of the material and the uniformity of its mass flow rate. Certain parameters of the working organs that perform agrotechnical processes with the vibration of technical systems during the sowing of materials and the creation of a compacted bed for seeds are determined. Certain parameters of the working bodies that perform agrotechnical processes with the vibration of technical systems during the sowing of materials and the creation of a compacted bed for seeds are determined. There are presented variants of the developed technological devices, both newly created and retrofitted existing batteries with spherical disks equipped with hydropneumatic cylinders, providing damping of vibrations of working elements to reduce uniformity of the seedbed. The levels of compliance of the indicators of technological processes performed by the developed devices, to agrotechnical requirements for sowing are shown.
Tractors and Agricultural Machinery. 2017;(9):31-36
pages 31-36 views

Analysis and refinement of design parameters of the machine-tractor unit based on the tractor K-744R-05

Antipin V.P., Valyazhonkov V.D., Durmanov M.Y., Kulikov V.N., Mikhaylov A.O.

Abstract

In accordance with the functional purpose of the designed tractor, the type and parameters of the transmission are selected according to the terms of reference. However, dynamic loading introduces adjustments to the parameters of the machine-tractor unit. For example, in the transport mode on the surface of the state of the amplitude-frequency characteristic of the tangential traction force of the tractor K-744P-05 at a regular speed υо = 3,6 m/s, the gear ratio of the transmission iт = 35,35, at a frequency ω = 8,0 S-1, the amplitude increases to 16.62 kN, accompanied by a «galloping» of the machine-tractor unit. The surface of the amplitude-frequency characteristic is obtained by calculation, and the transmission is adopted as a «stepless variator», limited by the gear ratio iт = 126,10 and iт = 20,30. This allows you to refine the amplitude of the oscillations between the nearest gear stages and adjust the gear ratios of iт value. The phase-frequency characteristics of the components of the dynamic component of the tangential pulling force are also calculated: inertial forces and forces from oscillations of the machine-tractor unit in the longitudinal-vertical plane. It was found that with the decrease in the center-to-center distance by 12,5 % (up to 2,8 m), the amplitude increased by 0,49 kN (2,9 %), and the amount of energy expended - up to 103,2 kJ / s, which is more by 14,46 kJ / s (14,0 %) than at the nominal interaxial distance l = 3,2 m. At the interaxial distance increased by 25 % (from 3,2 to 4,0 m), the amplitude decreased by 0,6 KN (3,6 %), and the amount of energy by 16,4 kJ / s (18,5 %). The increase in the phase delay of forces from oscillations of the machine-tractor aggregate in the longitudinally vertical plane from 45 to 59,9° reduces dynamic loading, and the reduction in the phase of inertial forces from 13,6 to 12,8° continues to support «galloping». After adjusting the transmission ratio of the transmission in the first gear of the fourth mode from iт = 35,8 to iт = 29,42, the regular component of the tangential traction force was decreased by 7,1 kN (17,9 %); total power consumption by 23,4 kW (9,7 %); hour fuel consumption by 5,2 kg / h; the oil consumption on the burn by 56 g/h. Simultaneously, the speed of movement increased by 0,77 m/s (21,6 %).
Tractors and Agricultural Machinery. 2017;(9):37-44
pages 37-44 views

Characteristics of external influences on the operation of machine-tractor units

Kambulov S.I., Rykov V.B., Bozhko I.V., Kolesnik V.V.

Abstract

The most significant feature of the operation of agricultural machine-tractor aggregates is the random nature of external influences, which determines its output indices. The main task of the theory of complex systems should be considered the development of methods that allow on the basis of their functioning to obtain the characteristics of individual elements and analyze the interaction between these elements and the external environment, to determine the characteristics of the system as a whole. The purpose of the study is to analyze the characteristics of external influences as a reaction to the operation of machine-tractor units. When solving many problems of agricultural mechanics (researching technological and production processes, building models and synthesizing the parameters of working organs and aggregates), it is necessary to take into account the external factors that determine the main regularities of various processes. The process of operation of the unit can be represented in the form of a set of states - vectors of output quantities: agrotechnical, technological, kinematic, energy-power and so on. The role of input quantities is played by external conditions and control actions, which also have a certain set of states. External influences on the unit are technological, operational and constructive factors, the number of which include soil resistance, the surface profile of the field, the physical and mechanical properties of the material being processed (soil density, soil moisture, etc.), the technical condition of the machine working bodies, and the depth of processing. As the speed of motion increases, the correlation between the sections of the random function decreases. As the speed of motion increases, the spectral density decreases, and its maximum value shifts towards higher frequencies; spread of the values of random function with respect to the mathematical expectation increases with increasing aggregate speed; by correlation functions and spectral densities, it is possible to establish the main parameters of random processes, variances, the mean square deviations prevailing in the frequency process and the corresponding periods, the dispersion distributions over frequencies that are necessary to establish the parameters of the output indicators characterizing the level of functioning of agricultural machine-tractor aggregates.
Tractors and Agricultural Machinery. 2017;(9):45-51
pages 45-51 views

Ballasting of tractors

Kut'kov G.M., Gribov I.V., Perevozchikova N.V.

Abstract

Recently, the ballasting of tractors has become widespread. Ballast is necessary to compensate for the decrease in the material consumption and excessive increase in the energy saturation of modern tractors, which arose due to the evolutionary development of their technical level. By using ballast, an artificial in-crease in weight and a decrease in the energy saturation of a new generation tractor are achieved to the level of its reference value inherent to cargo tractor. The article analyzes the application of ballast in the volume of the entire standard-sized row of tractors, the world's leading tractor-building companies. The evaluation of the main parameters of the tractor and the level of its ballasting is carried out using the con-cept of the reference energy saturation of the tractor and its specific value. The analysis showed that bal-last application is disorderly, chaotic. This is explained, on the one hand, by a large spread of energy satu-ration of tractors, on the other hand, by the lack of a unified approach to the goal of ballasting and the choice of ballast weight. Currently in the technical literature there are no generally accepted recommendations on these issues. In these conditions, the abundance in the market of varied offers makes it difficult to make the right choice when different ballast is offered to different models of tractors, identical or close to each other in terms of basic parameters. The chaotic nature of ballasting can adversely affect the economic exploitation of the potential opportunities inherent in the construction of a new generation tractor. There is an urgent need to carry out developments in the theory of engineering and the theory of technological operation of the tractor. Based on the results of the studies performed, the following recommendation is proposed. When choosing a tractor as an object of purchase, it is advisable to follow the rules: tractor with full ballast should have a reference energy saturation of 1,5 ... 1,6 kW / kN; The weight of the ballast must be equal to 25, 50 and 75 kN, so that when using it, an increase in tractive power of the tractor by 10, 20 or 30 kN, respectively (depending on the tractor traction class) is obtained. This recommendation is also valid for a set of ballast weights and tractor parameters at the stage of its creation.
Tractors and Agricultural Machinery. 2017;(9):52-60
pages 52-60 views

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