Vol 88, No 1 (2021)
Articles
Role of the Research Institute of Engines (NIID) in the development of special transport engines
Abstract
The history of the creation and development of the head institute of the Ministry of Defense Industry of the USSR for engines - the Research Institute of Engines (nowadays JSC “NIID”) is considered. Institute participated in the development and improvement of almost all post-war engines for armored vehicles: the 5TD (6TD), V2, 2V, UTD, GTD-1000T families and its modifications. Research and development of the institute ensured the provision of comprehensive technical assistance to the factories of the industry and the creation of an advanced scientific and technical reserve.
Tractors and Agricultural Machinery. 2021;88(1):6-13
6-13
Determination of the optimal composition of mixed fuel based on the environmental performance of a diesel engine
Abstract
The use of rapeseed oil (RO) in tractor engines and other agricultural machinery in its pure form or a mixture of RO with diesel fuel (DF) imposes a number of limitations associated with some difference in physical and chemical properties. Therefore, the most promising is the use of mixed fuel (MF) consisting of DF and RO. The purpose of these studies is to determine the optimal composition of the MF, consisting of DF and RM by optimizing the approximated dependences of the environmental indicators of a diesel engine. To solve this problem, bench tests of the operation of the D-245.5S diesel engine (4ChN 11,0/12,5) were carried out. The following determined environmental performance indicators of a diesel engine are selected: soot (С), nitrogen oxides (NOx), unburned hydrocarbons (CxHy), carbon dioxide (CO2) and carbon monoxide (CO). The studies were carried out on various compositions of MF, consisting of 80 % DF and 20 % RO, 55 % DF and 45 % RO, 20 % DF and 80 % RO by weight, respectively. As a result of the bench tests, two load characteristics were obtained, the one at a speed of n = 1400 min–1 corresponding to the value of the maximum torque, and the second at a speed of n = 1800 min–1 corresponding to the value of the rated power, as well as the external speed characteristic of the D-245.5S tractor diesel engine (4ChN 11,0/12,5). The analysis of the obtained experimental data revealed the dependence of environmental indicators on the rotational speed of the diesel engine crankshaft, the average effective pressure and the addition of RO in MF by weight. Using the least squares method, the approximated mathematical dependences of the ecological indicators of a diesel engine are determined. The analysis of the obtained dependencies showed that: the increase in the crankshaft speed n, the proportion of RO in MF and a decrease in the average effective pressure pe, leads to a decrease in soot С to 4,0 %, nitrogen oxides NOx to 100,0 ppm, unburned hydrocarbons CxHy to 1,0 ppm, carbon dioxide CO2 up to 2 % and an increase in carbon monoxide CO up to 0,16 %. As a result of solving the obtained system of equations for the approximated dependences of environmental indicators, the optimal addition of RO to MF of up to 35 % by weight was determined.
Tractors and Agricultural Machinery. 2021;88(1):14-22
14-22
Digital on-board clutch tester
Abstract
The work is devoted to the creation of a digital type on-board device for diagnosing the clutch of traction vehicles (TTM) and allows to determine with high accuracy the slipping of the clutch when faults appear in it. The principle of operation of the device is based on the use of digital technology for measuring the rotational speed (number of pulses) in the digital code of the flywheel and the input shaft of the gearbox (GB). With the help of light-emitting diodes, the received digital codes are displayed, displaying the number of voltage pulses per second from the flywheel speed sensors and the gearbox primary shaft gear. The received digital codes are converted by the driver (operator) into the decimal number system. Given that the number of flywheel teeth is greater than the number of gear teeth, the number of pulses from the sensors is adjusted by dividing the number of pulses from the flywheel per revolution by the ratio of the number of flywheel teeth to the number of gear teeth. Next, the difference between the corrected number of pulses from the gear and the flywheel is determined, which is compared with the permissible number of pulses and, based on the comparison, a conclusion is made about the technical condition of the clutch. If the difference is equal to zero or less, the clutch will be considered good. The device for diagnosing the clutch includes two digital speed sensors, each of which contains an inductance coil with a magnetic core, rigidly fixed near the flywheel teeth and gears of the input shaft of the gearbox. The first differentiating circuit, with a cut-off diode at the output, the input is connected to the inductor and is made on the first and second resistors and capacitor. The second differentiating circuit with a cut-off diode at the output is made on a resistor and a capacitor, and the input is connected to the output of the self-oscillating multivibrator. The self-oscillating multivibrator is made on two logical elements NAND, two capacitors, two diodes and two resistors. The output of the second differentiating circuit is connected to the zero-setting inputs of sixteen-bit summing electronic counters. The outputs of the logical elements AND are connected by means of resistors with the counting inputs of two electronic counters, at the output of which digital codes are formed, which reflect the rotational speed of the flywheel and gears of the input shaft of the gearbox. An example of calculating the parameters of the elements of the differentiating circuit of an auto-oscillating multivibrator is given.
Tractors and Agricultural Machinery. 2021;88(1):23-28
23-28
Synthesis of a system of inertial dynamic stabilization with control according to a set of parameters measured on board a self-propelled vehicle
Abstract
The work is devoted to the development of the direction of inertial dynamic damping and stabilization of self-propelled transport and technological machines with a mounted working body. The necessity and possibility of improving the previously developed control equations for the stabilization system has been substantiated. The description of the approach for the synthesis of the control system is given and the application of integral criteria for the formation of requirements for the transient processes of the control system is substantiated. A model of optimal control is proposed, for providing the information field of which a set of parameters measured on board the self-propelled vehicle is determined. The algorithm of the control system is adaptive, automatically reconfiguring the gain in the system depending on the change in its inertial parameters. On the example of the kinematic diagram of the drive by the mobility of the adapter of a modern forage harvester, a design diagram is presented for recalculating the values of the required stabilizing moments into the force developed by a hydraulic cylinder or other executive drive. The requirements for the information field of the stabilization system are given in the form of a set of measured parameters, the range of their measurements, the locations of the sensors and the permissible measurement errors. A set of criteria for the effectiveness and efficiency of the stabilization system is proposed. On the basis of numerical experiments, the values of the tuning coefficients of the stabilization system were selected and the transient processes of changes in the angles of the longitudinal inclination and the longitudinal angular velocity of the body were constructed under a single shock loading of the machine. It is shown that the proposed approach provides asymptotic stability of the considered oscillatory system. In order to assess the performance on the basis of simulation modeling, oscillograms of changes in the angles of rotation of the adapter and the forces on the rod of the hydraulic cylinder when the combine moves with the stabilization system turned on on a dirt road and asphalt concrete at different speeds are constructed. The evaluation of the development efficiency is given. The conditions for the modernization of the existing generation of combines for their equipping with the proposed stabilization system are formulated. Conclusions are formulated and directions for further research are determined.
Tractors and Agricultural Machinery. 2021;88(1):29-39
29-39
Evaluation of methods for experimental and analytical determination of the contour area of the contact patch of a pneumatic tire with a support base
Abstract
The results of experiments on the estimation of the error of methods of experimental and calculated determination of the contour area for the ecological assessment of a mobile energy device are presented. There was used the example of modern radial tires 360/70R24 of Bel-89 and 18.4R34 of F-11 agricultural tractor MTZ-1025.2. in modes of non-nominal loading at nominal load on tires and changes in tire pressure within the range recommended for field work. assess the possibility of improving the computational method for determining the contour area of the contact patch of the tire tread of a pneumatic wheel based on the mathematical model of V.L. Biederman. The assessment was carried out for four ways of determining the area of the tire contact patch: 1) directly measuring the area using a digital photograph of the tire contact patch in Kompas-3D V13 software with the determination of the scaling and method error using a square from 100x100 mm graph paper; 2) calculation by the formula of the area of an ellipse, using the length and width of the tire contact patch, measured with a tape measure directly from the obtained print; 3) by calculation, determined from the digital photograph in Kompas-3D V13 software; 4) by calculation, determined by calculation using the parameters of the universal tire characteristic (UTC).
As a result of the experiments, it was found that for modern radial tractor tires, the static deformation of which does not exceed 18–22 %, the method of theoretical determination of the contour area of the tire contact patch using the UTC parameters can be applied with sufficient (for engineering practice) accuracy. Full convergence of the calculated and experimental contour areas of the tire contact patch can be provided by the coefficient of their ratio. The carried out assessment of the possibility of using methods for calculating the conditional contour area of the tire showed that these methods can be well used for a comparative assessment of the technogenic mechanical impact of propellers on the soil.
Tractors and Agricultural Machinery. 2021;88(1):40-50
40-50
Development of the design of an internal combustion engine cooling system with a pre-starting heating function
Abstract
The main topic of the article is the development of an effective design for a pre-starting heating system for an internal combustion engine for conditions of limited power supply. The work to improve the design of light wheeled all-terrain vehicles on low pressure pneumatics is done at Pacific National University. Prototypes of light wheeled off-road vehicles are used mainly in agriculture and for forestry production. There are prerequisites for their use in oil and gas fields in the Far North conditions. This vehicle is operated all year round, in the absence of power supply, it is stored in the open air, so the problem of starting a cold engine is quite important, and the topic of creating a design for a pre-starting heating system for an internal combustion engine under conditions of limited or complete absence of power supply is relevant. The purpose of the work is to develop and study the efficiency of the pre-starting heating system for an internal combustion engine with liquid cooling for conditions of limited power supply. Our own design of the cooling system with a pre-starting heating function based on a gasoline burner was developed. To assess the efficiency of the engine warm-up process, the circuit was assembled on a light wheeled all-terrain vehicle. The experimental studies were carried out to determine the regularity of changes in the temperature of the engine coolant during pre-starting heating at different ambient temperatures. The results of the experiment indicate the high efficiency of the developed system based on a gasoline burner. The average heating rate of the engine coolant during the warm-up process was 2.1 - 2.8 оС per minute, which indicates an intensive pace of pre-starting heating.
Tractors and Agricultural Machinery. 2021;88(1):51-56
51-56
Features of the operation of engine oils in a combined lubrication system “engine-gearbox”
Abstract
The paper presents the results of studies on the possibility of recycling part of the heat dissipated by the engine lubrication system into the environment. To increase the efficiency of using waste heat, a contact method of heat exchange is proposed. Studies showed that this method, despite the efficiency of heat and mass transfer processes, the simplicity of devices for its implementation can not always be applicable. With the contact method, there is a direct mixing of two coolants: hot and cold, as a result of which the circulation rate is reduced by more than three times. This contributes to a decrease in the severity of the oil operating conditions in the “engine-gearbox” system. The hot coolant in this case is the engine oil of the running engine, and the cold one is the same oil located in the tractor gearbox. Physicochemical analysis of oil samples taken during operational tests of tractors showed that when extending the service life of the oil in the integrated lubrication system, the main indicators do not go beyond the limit states. It should be noted a slight excess of the content of mechanical impurities relative to their amount in the gearbox of a serial tractor, which is much less than the limiting value of 3%.
Tractors and Agricultural Machinery. 2021;88(1):57-63
57-63
Analysis of the effectiveness and the possibility of creating an auxiliary braking system for an electronically controlled vehicle of the utility patent No. 153 247
Abstract
The paper notes that electronic control of work processes in vehicle units and systems is one of the most effective and modern ways to improve their operational parameters. The means of electronics make it possible to increase the average speed of vehicles, reduce fuel consumption, improve controllability, stability, passability and smooth driving, improve braking performance and safety, and facilitate driving. All modern vehicle electronic systems are digital, data transfer rate is up to 1 megabit per second. This allows each sensor to be used for several systems. Dimensions of sensors are gradually decreasing, their speed, reliability, and accuracy are increasing. One perspective way to improve vehicles is the use of an internal combustion engine with electronic control of its braking torque as an auxiliary braking system. The analysis of the patent № 153 247 for useful model "Auxiliary braking system of vehicle with electronic control" is considered and its analysis using the valve timing diagrams. The errors made in the description of the patent were revealed. The description of the intake and exhaust strokes does not take into account the increase in the cylinder volume by the manifold volume due to the opening of the respective valves and the fact that the pressure in the exhaust tract is limited by the preloading force of the engine exhaust brake springs. The electromagnetic valve must have speed by an order of magnitude greater than the regular valves and the same capacity, its springs must have a large pre-pressure so that it does not open under the pressure in the receiver of the regular brake system. For fast pressure release, the electromagnetic valve must open a large flow cross-section as quickly as possible, overcoming the force of the high pressure acting on its disc in the cylinder (7.5 MPa) plus the force of pre-pressure of the valve springs. The formulas for determination of the valve throughput capacity of the valve, analysis of which showed that to ensure a given capacity of the valve by reducing its opening time it is necessary to proportionally increase the height of the rise of electro-magnetic valve or the average diameter that is not always possible. The analysis carried out in the article showed that the efficiency of the proposed system is lower than the declared one, and its creation is impossible because there is no electromagnetic air valve satisfying the requirements for it in this design.
Tractors and Agricultural Machinery. 2021;88(1):64-72
64-72
Evaluation of the efficiency of transport services for forage harvesters when harvesting maize for silage in Novosibirsk region
Abstract
An assessment of the efficiency of the enterprise for harvesting corn for silage through positioning and monitoring of vehicles was carried out. The calculation of the required power of the forage harvester for the smooth operation of service vehicles, that are responsible for the transportation of green mass, was done. An inconsistency was revealed between the departures of loaded vehicles and the arrivals of empty vehicles. The lack of positioning and monitoring tools negatively affects the productivity of the harvesting and transport process. As a result of the research, it was found that the actual performance of the forage harvester when harvesting maize for silage is significantly lower than the theoretical performance. Through experiments, the downtime of forage harvesters in the field due to improper organization of transport services was revealed. When analyzing the state of the park of forage harvesters and vehicles, the requirements of new approaches in solving transport problems were revealed. These contribute to a radical improvement of the transport process when harvesting silage crops. The obtained calculations and patterns of change in technical and technological parameters can be used for the design of new, special agricultural vehicles, as well as in the harvesting and transport process to determine the required number of transport units, when transporting chopped green mass. On the basis of experimental data the regularities of changes in the volume of the vehicle bed on the mass of the trailer and the dependence of the change in the volume of the vehicle bed on the mass of the trailer during transportation of green mass were obtained.
Tractors and Agricultural Machinery. 2021;88(1):73-80
73-80
Reducing the energy consumption of the aerodynamic heating dryer
Abstract
A promising direction in the development of drying plants in the technologies of processing fruit and berry raw materials is the use of aerodynamic heating dryers. They implement the principle of transformation of electrical energy consumed to drive a centrifugal fan into thermal energy due to mutual friction of air flows circulating in a closed chamber. In this case, the overwhelming part of the electrical energy supplied to the rotor is spent on overcoming aerodynamic losses in the flow path of the impeller and in the drying chamber. To reduce the energy consumption of the drying process by reducing the energy consumption for heating the drying agent in the drying chamber, it is proposed to utilize the heat of the spent drying agent by equipping the dryer with a combined heat exchanger. It combines a plate heat exchanger and a solar air collector. The aim of the study was to analyze the efficiency of using a combined heat exchanger to reduce the energy consumption of an aerodynamic dryer when drying apples. The operation of the drying plant was investigated with and without a combined heat exchanger. To record the parameters of the drying agent, the environment, and the consumption of electric energy, an eight-channel TRM-138 thermoregulator meter with thermal resistance sensors and an electric energy meter with current transformers were used. An eight-channel TRM-138 thermoregulator meter with thermal resistance sensors and an electric energy meter with current transformers was used to record the parameters of the drying agent, the environment, and the consumption of electric energy. The research results showed that the use of a combined heat exchanger made it possible to increase the temperature of the drying agent entering the drying chamber by an average of 20 ºС relative to the ambient air temperature. A more intensive increase in the temperature of the drying agent when using a combined heat exchanger made it possible to reduce the drying time by 3 hours. At the same time, electricity consumption decreased by 27.4%.
Tractors and Agricultural Machinery. 2021;88(1):81-87
81-87
Energy intensity of chopping fructified raspberry stems
Abstract
The article analyzes the results of measuring the force required for the destruction of a dried raspberry stem by means of transverse action on it. There was used as a variant of the experiment the cutting of stem with support at one and two points, as well as breaking it with a distance between the supports of 30 and 54 mm. It was found that the force on the working body linearly depends on the diameter of the stem. The essential dependence of the required force on the method of action on the material was confirmed. It was revealed that the effort to cut a dried stem is significantly higher than the effort required to break it. To implement the breaking process, a working body in the form of a pair of horizontal twelve-blade rotors mounted with a radial overlap between them by an amount approximately equal to the distance between the outer edges of the adjacent blades is proposed. In this case, the rotors should have a diameter of about 200-210 mm. In addition, they must be equipped with a synchronous drive and shifted in phase by an angle of 150. As a result of modeling the phases of the destruction of the stem by transverse fracture, the force and energy parameters of the process were obtained. With a rotor length of one meter and simultaneous crushing of 25 stems, the average power required to drive is 9.3 kW, with a probability of peak values of 16.4 kW. When calculating the strength, it should be taken into account that a distributed load of up to 12,400 N acts on the rotor shaft in the vertical plane and a distributed load of 2,750 N acts in the horizontal plane. A prototype grinder was tested and proven to work.
Tractors and Agricultural Machinery. 2021;88(1):88-95
88-95
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