Архив рубрики 'Articles' summaries'

Noise in cab of a crawler agricultural tractor

    I.F. Belyy, PhD in Engineering
    I.A. Bogdanova, Engineer

    North Caucasus Machine-Testing Station, Zernograd, Russia, mis1@mail.ru

The working conditions of operator are considered as one of the most important indicators of technical level of a machine and its competitiveness in agricultural machinery market. The article presents the measuring data of noise level on operator workplace, based on the results of long-term tests of crawler agricultural tractors of 3 drawbar category for general purposes. Measurements of noise level in tractor cabs were carried out according to the requirements of state standards when performing the main type of works, namely the stubble tillage after harvesting of spiked cereals. Tractors produced by Volgograd tractor plant in 1993-2000 conformed to the sanitary regulations of tractors’ and agricultural machines’ technology and had the noise level about 78-80 dBA. Subsequent upgrading of crawler tractor’s cab led to worsening of work conditions in respect of noise. Noise level in cab of the Agromash-90TG 1040А tractor produced by Volgograd tractor plant in 2012-2015 reached 88-90 dBA. The analysis of the results of measurement of noise levels allows to make a conclusion that the main noise source in upgraded cab is the exhaust tube of engine. The construction of cab does not protect the operator against the noise of engine. Furthermore, the use of microclimate normalization system in cab of the Agromash-90TG tractor does not provide the reduction in air temperature to a comfortable level of 24-27 degrees C. Test results revealed that working conditions on the new tractor do not conform to the requirements of standards. Specialists of tractor industry organizing a new production of crawler agricultural tractors should take into account the previous experience of engineering developments in Volgograd tractor plant and results of state tests of tractors.

crawler tractor; noise level; cab; comfort conditions of work.

Experimental research of conditions of cylinder oil supply in high-speed four-stroke internal-combustion engine

    S.V. Putintsev, DSc in Engineering
    A.G. Ageev, Engineer

    N.E. Bauman Moscow State Technical University, Moscow, Russia, putintsev50@yandex.ru

The research is relevant because oil supply processes in the cylinders of four-stroke piston engines with traditional cranking mechanism and combined lubricating system are understudied. The research aims to receive the experimental data on pattern of motor oil distribution by circumference of cylinder for the specified type of internal-combustion engine. The measurement method is based on organization of drainage and following quantity control of oil that is removed by piston rings from internal surface of the cylinder. Experimental device corresponding to this method represents the low-sized high-speed four-stroke air-cooled TMZ-450D diesel engine having a cylinder with six oil-catch through holes executed in its bottom support belt and supplied with thin-walled tubes. Tests were performed under rotation of crankshaft by means of outside source (balanced engine) with nominal speed. The oil filling of any first of six tubes was considered as a moment of ending for each experience. The quantity of oil in tubes was controlled by measuring of oil column length in every tube. During cranking both with air compression and without it, experiments show that quantity of motor oil removed by piston rings from non-loaded cylinder wall side in all cases is more by 15-18% than from the loaded one. Such pattern of oil distribution by circumference of a cylinder at which non-loaded side receives more oil than the loaded one, points to the infringement of principle of coordination between lubricating and loading conditions. That increases the risk of wear and bore scuffing in cylinder-piston unit. In spite of limitation by only one method and one object, the received results show the expediency of following studies of features of cylinder oil supply for the specified type of engines to increase their work reliability.

cylinder; cylinder-piston unit; four-stroke internal-combustion engine; motor oil; oil supply.

Unmanned mobile power unit for agricultural purposes

    Z.A. Godzhaev, DSc in Engineering
    A.P. Grishin, DSc in Engineering
    A.A. Grishin, PhD in Economics
    V.A. Grishin, Engineer

    All-Russian Research Institute of Agricultural Mechanization, Moscow, Russia, vim-transport@mail.ru

It is shown that the basis of robotic technologies in plant cultivation is an unmanned mobile power unit for agricultural purposes on wheeled or tracked platform with hybrid power plant, motion control and machine vision equipment. Description of software algorithm and schematic circuit diagram of motion control are given. It is noted that machine vision is an integral part of working organs, because much of the information about the state of plants (growth rate, maturity degree, disease) is received through visual contact, as well as through systems of motion control and precise positioning. This information allows the robotic working organs to find the technological solutions and implement the required operations, and the unmanned mobile power unit to move on process route. Another fundamental function of unmanned mobile power unit is positioning and motion control on required trajectory. A brief analysis of implementation of this function by means of satellite navigation or ground facilities of positioning including machine vision and target indication is given. Satellite navigation systems provide positioning and identification on large areas, but do not work indoors. Network wireless system of local positioning allows to control the location and motion of objects and reliably identify them both outside and inside the premises. Combined application of such systems allows to extend the motion control of vehicles and agricultural machines to areas not directly visible for satellites: covered yards, buildings. That creates additional opportunities for control of local movements of products and personnel in industrial and non-industrial premises of closed and open type.

robotics; unmanned mobile power unit; machine vision; technological robotic modules.

of abrasive wear resistance of parts by means of variation of welding technique of double-layer coatings with hard surface

    I.V. Kozarez, PhD in Engineering
    M.A. Mikhal’chenkova, Engineer
    V.I. Lavrov, Engineer
    N.V. Sinyaya, PhD in Engineering

    Bryansk State Agrarian University, Kokino, Bryansk region, Russia, spo@bgsha.com

The double-layer welding applied for restoration of parts of construction, road and tillage machinery allows to create a coating that resists shock loading and prevents abrasive wear. It is determined by significant differences between the properties of the lower layer that is relatively soft and the upper hard layer. Known researches of this method do not consider the influence of welding technology on the wear resistance of obtained coating in an environment with high content of abrasive inclusions. The aim of the paper is to determine the degree of influence of technological methods of double-layer coatings formation on the wear of parts used in soil medium. The welding was carried out manually during restoration of ploughshares with ray-shaped wear according to four variants of technology. The wear was controlled by weight loss. Experiments reveal that the wear in function of operating time is in straight-line dependence for all technology variants. Operating time before reaching the steady state mode of wear and the limit state depends on welding technique. The influence of methods of coating formation technology on abrasive wear resistance that is due to the difference of thermal influences on weld metal is considered. The optimal technology variant for maximum wear resistance of coating is cooling of each bead by applying both first and second layers. The implementation of such welding technology allows to increase the abrasive wear resistance by 30% in comparison with other methods. The use of double-layer welding technology increases the resource of restored ploughshare by two times in comparison with a factory-made one.

double-layer welding; wear resistance; welding technique; thermal regime; abrasive wear; operating time; service life.

Universalization of plow-bottom surface of working organ of a plow

    V.V. Blednykh (1), DSc in Engineering
    P.G. Svechnikov (1), DSc in Engineering
    I.P. Troyanovskaya (1), (2), DSc in Engineering

    (1) South Ural State Agrarian University, Chelyabinsk, Russia, mail@csaa.ru
    (2) South Ural State University, Chelyabinsk, Russia, tripav63@mail.ru

Economical cultivation of different soils on different speeds requires working organs with different parameters. Using plows with optimal parameters of plow-bottom surface will allow to minimize the cost of tillage with no loss in quality. Such parameters of working surfaces as setting angles of plowshare, bend of mouldboard and others are considered. Adjustment of working organ of a plow by rotating and offsetting will provide the most useful type of plow-bottom surface and better quality of tillage with the use of a single working organ for different soils and speeds. The paper presents a newly developed way to compare the topology of two plow-bottom surfaces with the use of criterial filter-function, as well as original methods to input the data on the topology of plow-bottom surfaces and to approximate these data by polynomial dependencies for smoothing and providing the unimodality of objective function of optimization when using the Hooke and Jeeves method. The optimal angles of rotation (12 degrees) are obtained whereby the deviations of a comparison plow-bottom surface and a basic one are minimal. According to the agrotechnical and technological requirements on the overlap of operating widths between the working organs, the first working organ of plow should be attached without offset, the second one depending on the realized speed should have an offset of 70 mm, the third – of 140 mm, the fourth – of 210 mm. The practical results of using the developed method for universalization of plow-bottom surface are presented.

universalization; plow-bottom surface; spatial turn; topology; alignment of normal lines; agrotechnical requirements.

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