Vol 86, No 4 (2019)

Articles

Control of fuel sprays activity in starting and after starting warm-up periods of diesel engine

Krohta G.M.

Abstract

During starting and after-starting warm-up periods of the engine, fuel supplied to the combustion chamber by the injector heats and partially evaporates by means of compressed air exergy. In this case, mainly forms large drops, the amount of which can reach 85…90 % in the cyclic feed. Large drops can not completely evaporate, reach the cold combustion chamber walls, where they condense and don’t participate in combustion, which worsens starting qualities and increases incompleteness of combustion. Clearly that improvement of starting qualities of diesel engine and reducing of combustion incompleteness during after-starting period can be accomplished by the increasing of air charge exergy in the end of compression stroke, or increasing of fuel exergy which sprays in combustion chamber. Experimental research have shown that engines which equipped with traditional fuel system with injection pressure up to 20 MPa, fuel activation provides mainly (on 96,8 %) by means of air charge exergy. The structure of air charge exergy losses is distributed as follows: to heat the fuel to average boiling point - 75 %, evaporation - 12,5 % and 12,5 % - to heat the fuel vapor of total evaporation losses. Thus, a high level of air charge energy supply makes possible to control the quality of fuel mixture formation during starting and after-starting warm-up periods by means of changing the value of thermomechanical part of fuel spray exergy.
Tractors and Agricultural Machinery. 2019;86(4):3-11
pages 3-11 views

Load characteristics of a vehicle diesel engine using natural gas as a fuel

Lihanov V.A., Skryabin M.L., Grebnev A.V.

Abstract

The article presents the load characteristics of the D-245.7 diesel engine when working on the gas-diesel process. The graphs of changes in the indicators of the combustion process, heat release characteristics, effective indicators are given. The problem of increasing the cost of gasoline and diesel fuel, the limited natural reserves of oil push to the need to find alternative fuels for automobile transport. Among the entire list of promising fuels, natural gas has many advantages. The most important advantage is low cost. It is important to study the issues of converting diesel engines to natural gas, as diesel engine is the most common in the national economy. The most suitable way to convert diesels to natural gas is to implement a gas-diesel working process, since it does not require a significant alteration of the engine. The diesel engine D-245.7 was selected as the object of study. During the study, among other things, the load characteristics of this diesel engine were taken while working on the gas-diesel process. When analyzing the experimental data obtained in the gas-diesel process compared to the diesel one, some features were noted. At the gas-diesel process, an increase in temperature and gas pressure in the cylinder is observed. Heat dissipation happens much faster. This indicates the volumetric nature of the ignition and combustion of natural gas. Engine power during the transition to the gas-diesel process is maintained at the same level, while the consumption of diesel fuel due to the substitution of natural gas is reduced by several times.
Tractors and Agricultural Machinery. 2019;86(4):12-17
pages 12-17 views

Resource-saving technological process of cleaning the lubrication system of tractor engines from pollution

Ostrikov V.V., Vyazinkin V.S., Zabrodskaya A.V.

Abstract

The issues of cleaning the engine lubrication system from pollution by used engine oils without draining them from the crankcase are considered. It has been established that adding monoethanolamine mixed with isopropanol to the engine oil that worked in the engine allows the resins and oxidation products dissolved in the oil to be enlarged to sizes that are easily removed by cleaning agents built into the lubrication system. It was determined that the subsequent addition of dimethyl sulfoxide and white spirit to the oil gives the oil high cleaning properties. According to the results of comparative tests, it was found that the contamination of engine parts after washing the lubrication system with commercial washing oil is reduced by half. Using the developed washing process allows to reduce the contamination of the main parts by 4 times. Compression in the cylinders after washing the D-240 engine according to the developed method increased from 2 to 2,5 MPa, fuel consumption decreased from 13,9 to 11,3 l/h. The content of insoluble sediment in the oil after washing the engine with the developed method was 0,65 %, while in a special washing oil it was 0,37 %. These facts confirm the high washing properties of the composition. In general, the developed flushing technological process allows, under the conditions of agricul-tural enterprises, to clean the lubrication system and engine parts from pollution without the use of expen-sive flushing oils. Cleaning of engine parts from pollution increases the service life of equipment and reduces the cost of repair and maintenance of worn-out agricultural machinery.
Tractors and Agricultural Machinery. 2019;86(4):18-21
pages 18-21 views

Improving the design of the trolley for the manual harvesting of strawberry

Ozherelev V.N., Ozhereleva M.V., Somin V.V.

Abstract

The main goal of the research is to identify the degree of influence of the asymmetry of the resistance forces on the rolling wheels of a trolley designed to relocate the picker in the strawberry garden plantation when hand picking berries on the stability of its straight-line movement. The theoretical hypothesis was formulated in relation to a three-wheeled cart, the front wheel of which is controllable and located in the central aisle, and the rear wheels - in two adjacent wheels. According to the results of calculations, with such an arrangement of the cart, ensuring the straightness of its movement only by varying the position of the reference point for the collector's leg when it is pushed away from the aisle surface is already difficult with a twofold increase in the resistance to rolling for one of the wheels. As a result of an experimental three-wheeled trolley test, it was found that when using wheels from a 700-mm diameter bike and its additional loading with ballast weighing 704,6 N, simulating the average weight of the picker, the triple difference between the wheel rolling forces occurs when an additional obstacle appears in front of one of they are only 13 mm high. When raising the height of an additional obstacle to 45 mm, the degree of differentiation between the forces of resistance to rolling wheels increased to 8,3 times. In this regard, it is advisable to supply the trolley with a device for additional manual adjustment of the process of its straight-line movement along the rows. In the experimental version of the trolley for this purpose, a lever was mounted on the axis of rotation of the front wheel fork, the free end of which was brought into a zone convenient for access by the assembler’s left hand.
Tractors and Agricultural Machinery. 2019;86(4):22-27
pages 22-27 views

Transformable working bodies for nonmoldboard cultivation of soil

Parhomenko G.G.

Abstract

To perform technological operations in various soil and climatic conditions the developed designs of tillage tools should be based on the principles of transformation carried out by block-modular construction and compilation them with various working bodies using a scientifically based combination of inter-changeable elements. Objective: to improve the technological process of nonmoldboard cultivation of soil and the development of new transformable working bodies for its implementation. The basis of the pro-posed new transformable working body for nonmoldboard cultivation of soil is chisel in the form of a rack curved in the longitudinal direction with a chisel welded to it. Forcibly fixing the paws at an angle of 90° relative to the rack in the transverse vertical plane, the working body is a plane cutter, when dismantling the paws it is a chisel, when the paws are hinged, it is transformed into the chisel with the paws self-installing in the transverse vertical plane at an angle of natural cleavage of the soil. The crushing of the formation by new transforming working bodies for moldless soil tillage with articulated paws is carried out along the path of least resistance due to self-installation at an angle of natural soil cleavage. A decrease in traction resistance by 9,09 % of new transformable working bodies for subsurface tillage with articulated paws is observed. The use of articulated paws has a positive effect on the dynamic characteristics of the tool since there are no peak amplitudes in the broadband spectrum of oscillations of a relatively low level, so resonance phenomena are unlikely. According to the nature of the flow of the correlation function, the oscillatory process of the functioning of new transformable working bodies with articulated legs is established, which is characterized by the appearance of a harmonic component of the oscillatory process of the moving elements of the working body. To ensure control of the required parameters of the oscillatory motion, it is necessary to equip the structure with an elastic element, adjusting its rigidity. New transformable working bodies for nonmoldboard cultivation of soil are not inferior in terms of agrotechnical indicators to modern technical means.
Tractors and Agricultural Machinery. 2019;86(4):28-36
pages 28-36 views

Design of a torque sensor on the shafts of a wheeled tractor

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

Abstract

To improve the efficiency of wheeled tractors, it is necessary to improve their fuel efficiency and patency. This can be achieved by the use of torque sensors installed on the driveshaft of the transmission on tractors, the current load value from the output of which can be used in automatic control of the tractor or subjectively by the driver. The authors propose a method of selecting the parameters of such a torque sensor, which generates a voltage proportional to the angles of the cardan shaft and, accordingly, the transmitted torque.
Tractors and Agricultural Machinery. 2019;86(4):37-42
pages 37-42 views

Vibration protection of the hydraulic suspension system of mobile vehicles using active regulation by a neural network controller

Godzhaev Z.A., Sen'kevich S.E., Kuz'min V.A.

Abstract

Most of the time of operation, wheeled agricultural tractors work in fields with different soil back-grounds and in transport on dirt roads or even off-road. Under these conditions, a suspension system is needed to ensure the smoothness ride and effective vibration protection of the operator. Purpose of the study. To develop a new sliding mode controller based on radial basis functions in a neural network (RBFNN), implemented for an active suspension system of ¼ of a part of a mobile energy facility (MF). Materials and methods. The control algorithm is based on radial basis functions and combines the advantage of an adaptive control system and slip mode control. The adaptation rule is used to regulate basic functions based on information about a given sliding surface in real time. Since this approach has the ability to learn, its implementation can be started without any initial RBFNN values. It is proposed to use the neural network to control the parameters of the sliding mode. Results and discussion. To control the active MF suspension system, an adaptive RBFNN sliding mode controller is proposed. The adjustable parameter for the RBFSS controller is selected as gs = 8,5 to cover the range of Gaussian functions. Conclusions. A new controller for the sliding mode of a hydraulically active suspension system based on a neural network is proposed. Simulation results show that due to the use of this neural network controller, the suspension system quite effectively reduces the vibrational activity of the oscillatory system of the studied MF from road irregularities.
Tractors and Agricultural Machinery. 2019;86(4):43-49
pages 43-49 views

Improving the design of the tractor seat

Dmitrieva E.V., Myakishev A.A.

Abstract

Nowadays the fundamental and most important task of the development of agriculture in the country is to create safe working conditions that could ensure maximum efficiency and effectiveness of agricultural work. Undoubtedly, without observing labor protection, the risk to the life and health of rural workers, especially tractor drivers, increases and this translates into a significant increase in the percentage of occupational diseases. A serious problem when working on tractors is the general vibration (vibration transmitted to the tractor driver through the tractor seat), which level exceeds the permissible limit. In order to improve working conditions when working on a tractor, an improved design of the tractor seat is proposed. Its use due to the installation of a hydraulic shock absorber and an additional spring will allow maximum damping of vibrations acting on the seat and directly on the tractor driver when driving off-road.
Tractors and Agricultural Machinery. 2019;86(4):50-53
pages 50-53 views

Influence of angular damping coupling on the vibrations of a triaxial two-section non-suspension wheeled vehicle

Novikov V.V., Pozdeev A.V.

Abstract

This article is devoted to the study of the influence of angular damping coupling (АDС) on the vibrations of a triaxial two-section non-suspension wheeled vehicle. To assess the effect of the damper in the articulation unit on the vibrations of such a vehicle, three options for combining the parameters of the suspension system and the ADC are considered: wheeled articulated vehicle with suspension and without ADC; wheeled articulated vehicle without suspension and without ADC; wheeled articulated vehicle without suspension and with ADC. Based on the generally accepted assumptions of the linear theory of suspension, a calculation scheme and a mathematical model of the angular oscillations of a triaxial two-section non-suspension wheeled vehicle with ADC in the articulation unit are presented. During finding analytical solution, expressions for the gain of oscillations for the folding angle of identical sections were found and their maximum values in resonance were determined. For the considered options, the ratios of the amplification coefficients of the angular oscillations in resonance and the expressions for the relative damping coefficient of the oscillations along the folding angle of the sections are determined. The calculated amplitude-frequency characteristics (AFC) of the folding angle of the sections for various combinations of ADC parameters in the presence and absence of suspension of the vehicle sections are presented. It is established that the introduction of ADC for a wheeled non-suspension vehicle allows one to reduce the amplitude of angular oscillations in resonance by 10 times. And, when using wheels, the rigidity of which is equal to the stiffness of the suspension, for non-suspension articulated vehicles, an even greater decrease in angular oscillations to a dynamic coefficient of 1,7 is possible. At the same time, the angular damper for the non-suspension vehicle, the inelastic resistance of which is equal to the total power of all 8 shock absorbers of the sprung vehicle, provides smaller angular oscillations in the entire frequency range of the kinematic disturbance on the side of the road. It is advisable to use the proposed articulated layout arrangement of non-suspension vehicle with UDS for developing promising wheeled vehicles, for example, tractors and heavy vehicles with large-diameter wheels.
Tractors and Agricultural Machinery. 2019;86(4):54-61
pages 54-61 views

Performance assessment of motor oils by the wetting angle

Vahrushev V.V., CHerepahin S.O.

Abstract

The problems associated with improving the reliability and durability of internal combustion engines largely depend on the quality of the fuel and lubricants used. One of the indicators of the quality of working engine oil is the wetting angle. It allows to assess the contamination of the oil with insoluble products and the ability of oils to disperse them. The method consists in determining the dispersing-stabilizing properties of a working engine oil, the degree of oil pollution by the contact angle of oil wetting on the surface of the substrate. Motor oil is a colloidal fluid that is layered. At the top of the drop is an additive that coagulates solid pollutants, at the bottom there is the base oil with a liquid pollutant. This method provides an unambiguous assessment of the dispersing and stabilizing properties of working oils, since the wetting angle in different layers of a drop of motor oil is taken into account. Contamination of engine oil with mechanical impurities, characterizing the dispersing properties of working engine oil, is determined by the angle in the upper layer of engine oil. Assessment of the wetting angle is to determine the boundaries of the spreading of motor oil on the surface of the substrate. Experimental studies have shown that: the wetting angle of a working motor oil on surfaces varies within: on a steel substrate from 5,36 to 20,62°; on a copper substrate from 7,45 to 20,39°; on a plain bearing substrate from 6,62 to 11,73 °. However, according to the results of the study, it was revealed that the substrate made of a plain bearing is wetted at any content of contaminants. From which it follows that substrates based on steel (cast iron) and copper should be taken as a criterion for the wetting angle, since they more closely reflect the diag-nostic feature.
Tractors and Agricultural Machinery. 2019;86(4):62-68
pages 62-68 views

The use of hardness testing to assess the technical condition of common rail fuel lines

Sveshchinskij V.O.

Abstract

High pressure fuel lines are one of the most important components of the fuel supply systems of internal combustion engines. The development in Russia of its own production and maintenance system for engines with fuel equipment such as Common Rail is still taking place in conditions of insufficient regulatory and technical base. To date, only one technical specification has been developed for the supply of rolled products and GOST, which is, in fact, an authentic translation of the ISO international standard that regulates the technical requirements for seamless steel pipes. There are no standardized requirements directly on products, including methods for their testing and diagnostics. At the same time, the high pressure fuel lines of Common Rail systems have significant differences from their predecessors - the fuel lines of mechanical systems. However, the methodological foundations for assessing the technical condition and durability of Common Rail components have not yet been developed. At the same time, there is a great scientific and technical reserve in the field of research of pipelines of the fuel and energy complex, including oil and gas transportation systems. Numerous standards, developed, for example, at PJSC GAZPROM, and regulating important issues of design, diagnostics, and assessment of the technical condition of oil and gas pipelines, are quite effective. It seems logical and reasonable to use, with appropriate modification and refinement, the experience of specialists in this field to create a regulatory framework for high pressure fuel pipelines of Common Rail systems. A prerequisite for the diagnosis of common rail fuel lines in operation is to maintain the integrity of the fuel lines, i.e. non-destructive testing. Taking into account the availability of technical equipment, the most effective control method should be hardness testing. An attempt is made to review the well-known works on the use of hardness measurement for studying pipelines of the fuel and energy complex with an assessment of their possible application for common rail pipelines.
Tractors and Agricultural Machinery. 2019;86(4):69-79
pages 69-79 views

Increase in rust resistance of farm vehicles at storage due to use of new protective lubricant

Stepanov N.V., Shukhanov S.N.

Abstract

Innovative development of agro-industrial complex assumes not only perfecting of the existing technical means and technologies of mechanization of agriculture, but also creation new devices, which meet modern requirements. The key part in manufacturing of the village products is assigned to its hardware. Particular importance has the smooth operation of farm vehicles. Because of seasonal nature of work in the agrarian sector the important place is taken by storage of vehicles, which usually happens at the open areas. The objective of the study was to expand the ability to increase the corrosion resistance of metal parts of agricultural machines when stored in open areas through the use of new additives. The use of used engine oils of autotractor engines; the saponified tall pitch - the waste formed by production of paper and cardboard. This problem is achieved by the fact that the proposed lubricant containing used engine oil, emulsifier, additive and water contains saponified tall pitch as an emulsifier, nitric acid as an additive in the following ratio, wt.%: Used engine oil - 20-40; saponified tall pitch - 2,0-4,0; nitric acid - 0,15-0,45; water is the rest Tests have confirmed that the use of a lubricant of this composition eliminates the corrosion of metal parts of agricultural machinery when stored in open areas due to high adhesion. This lubricant doesn’t demand heating. The use of used motor oils eliminates the use of expensive oil-based petroleum compounds for lubricants.
Tractors and Agricultural Machinery. 2019;86(4):80-84
pages 80-84 views

The use of combined convection-microwave processing line for drying fruits and vegetables

Korolev A.A., Prokopenko A.V.

Abstract

The article presents the experience of operating microwave drying plants, which are used in the technology of processing agricultural raw materials. The technological solutions for the development and use of microwave conveyor drying plants for drying plant materials were proposed. The obtained parameters of energy consumption and dynamics of the drying process allowed to determine close to the optimal transition boundary of the energy supply. The optimum value of transient humidity (at the boundary of the microwave and convective modules) is determined to be in the range from 28 to 35 %. The use of the combined energy supply method in drying technologies for fruits and vegetables allows to reduce the energy consumption of the process by 20-30 %. The examples of successful implementation of the proposed drying method in the food industry are given.
Tractors and Agricultural Machinery. 2019;86(4):85-90
pages 85-90 views


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