The damages of corn grain during threshing depend on many factors, the main of which is timely removal of grain from the threshing chamber what depends on the design of the deck. The functional parameters of the deck in self-propelled combines and stationary threshers used for threshing of seed corn have been studied. Studies of factors affecting the separation process of a mixture consisting of grain and other parts of corn cobs in the threshing chamber were carried out. It has been proved that the shape, size and layout of the deck holes have the greatest impact on the timeliness of the output of the threshed corn grain from the threshing chamber. In this case the deck should consist of three parts of different lengths: 1) a part of the deck of the chamber of the primary damage of the integrity of the cob grain structure; 2) the deck part of the main threshing chamber; 3) the deck part of the finish threshing chamber. The evaluation criteria for choosing the lengths of the deck parts are the average of the double ratio of the linear dimensions of the corn grain of the six main subspecies and the maximum length and diameter of the cobs of 65 main varieties cultivated in Russia. The ratio of the lengths of the first two sections of the deck should correspond to the Fibonacci golden section-1.618 and the double ratio of the linear dimensions of all three sections-1.29. The studies have evaluated the effect of the shape of the holes: round, round lunate, square, rectangular, and hexagonal. At the same time, the pattern of holes on the hexagon and the square and the square holes, additionally, at an angle 45 º to the rotor axis was studied. The feasibility of using round holes in the deck with a diameter of at least 10…14 mm has been established. As a result of using the deck of the proposed design, the conditions for timely removal of threshed grain from the threshing chamber with a reduced probability of damage are created.
Based on an overview of methods for hardening and restoring parts of agricultural machines, it has been found that the methods currently used are highly labour intensive and are not well suited for hardening the cutting edge of tillage machine discs. A method of electromechanical hardening of ploughshare discs due to simultaneous thermal action and plastic deformation is disclosed. Electromechanical hardening modes are justified on the example of standard cylindrical samples. The developed technique contains the following stages: determining the steel grade of a part; planning of the experiment based on the plan of the full two-factor three-level experiment with selection of influences and response function; experimental hardening of laboratory samples at the installation; microstructural analysis of hardened samples; numerical processing of experiment results. Based on the optical emission analysis, it was found that the samples are made of steel 65G. The factors of influence are: current strength X1(Ir) = 800...1200 A on the reinforcing tool in the form of a roller and the pressing force X2(Fk) = 100...300 N of the tool to the part. The hardness of the surface layer Y(HRC) is adopted as the response function. Microstructural analysis showed that a layer consisting of several zones was formed on the hardened surface of the sample: white, light non-flowing and dark martensitic, passing into the ferrite-pearlite structure of the base. On the basis of multiple regression analysis, an empirical mathematical model is obtained and its graphical interpretation in the studied area of factors values is given. According to the criterion of providing wear resistance of working edges of disks, maximum hardness is achieved at current strength X1(Ir) = 1060 A and force X2(Fk) = 210 N in the contact zone. Developed technique and tested modes of electromechanical hardening are suitable for development of process of hardening of disk ploughshares of grain-grass seeders.
The way of solving the problem of surface wear of products from cast iron due to development of technological processes of its strengthening treatment is offered in this article. Receiving the hardened skins is reached by purposeful formation of the set structural condition of metal by methods of surface impregnation, i.e., modifying. Results of researches on thermochemical treatment of cast irons of grades EN-GJL-250, EN-JS1060 are presented The micro-structural analysis showed that with rising the saturation temperature and increasing the process duration the layer depth cartbonitration increases. Studying the samples for wear resistance carried out on stand ММ 295 showed that for grade EN-GJL-250 it increased 2,2 times, and for grade EN-JS1060 – 3 times as compared to the initial (non-modified) state. Experimental-industrial tests of products of cast iron (model accessory, parts of homogenizing pumps) after carbonitration permitted to state 2-4 times of its surface.
The quality of agricultural engineering education and the ability to innovation activity determine the prestige and competitiveness of universities, the possibility to attract intellectual and material resources and therefore to create the necessary conditions for training of agricultural engineering personnel. An analysis of workforce needs shows that manufacturing enterprises need specialists with a high level of practical skills. Universities are trying to cancel for this effect by implementing practical aspects of agricultural engineering education as a basic criterion for acquisition of general professional and professional competencies. The competencies of graduates of agricultural engineering direction have been determined on the basis of the analysis of existing methods of education, the modern state of technologies and equipment of the agro-industrial complex. They require strengthening of practical training in the process of education. It has been experimentally confirmed that the possibility of obtaining additional working professions during the training period not only strengthens the practical component, but also contributes to increasing interest and general motivation to improve professional skills. A training methodology has been developed. It has been tested on the disciplines "Perspective Geometry. Engineering Graphics" and "Material Science and Construction Material Technology" based on the application of practical-oriented forms of interactive training in the form of round tables, master classes and trainings. The methodology is recommended for wide application in universities of the system of agrarian education of the Russian Federation in the field of education 35.03.06 "Agricultural engineering". Research prospects are conditioned by the need to continue programs in the sections of the disciplines "Mechanics", "Metrology, Standardization and Certification", "Machine Elements and Principles of Design" and extension of the present experience within the framework of international cooperation.
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