卷 84, 编号 1 (2017)

Following the results of the international Agrosalon 2016 exhibition both quantitative, and qualitative indicators of the domestic market of farm tractors are estimated. Dynamics of the market of new tractors in physical calculation is provided by statistics of the last nine years. Quality assessment of the market was carried out on indicators: propeller type, rated power and nominal towing force based on the models of: universal, row crop and general purpose tractors presented at the market and offered in advertizing documents. New approach to market research of tractors is distribution of set of models not only on capacity as it is accepted everywhere, but also on towing classes. The last allows to estimate not only power, but also towing opportunities of tractors that it is important as the tractor is mainly the towing machine. The following features of the domestic market of tractors are noted. The prevalence of wheel tractors 4K4a which was outlined in to and post-crisis years remains. The maximum tractor size in it to group - the tractor power of 300 kW and a towing class 5 (Claas Axion 950). In group 4K4b tractors capacity 50-90 kW (a towing class 1,4), St. 90-130 kW (a towing class 2), St. 130-180 kW (a towing classes 2,3,4) prevail. Interest of participants of the market to powerful wheel 4K4b (power to 450-480 kW, traction classes 6 and 8) and to caterpillar (power to 400-460 kW, towing class 8 and more) tractors increased. It is noted that general rule of creation of constructive tractors ranks of the leading firms is the engine capacity, and devlopment of ranks goes with an advancing growth of driving function over towing. The overview of the models of tractors provided or advertized by firms with indication of features of a design is provided. It is emphasized that the Salon showed not decreasing activity of the largest manufacturers of farm tractors in the market of the Russian Federation.

The studies were performed to improve workflow of hydraulic automatic control systems of the tillage units. Tillage quality should not deteriorate. Working bodies of tillage machines have to be moved automatically. Automated devices can be separated into two groups: direct and indirect action. It is preferable to indirect action. The article presents analysis of automatic devices used into tillage machines. Automatic control systems can be hydraulic, electro-hydraulic and pneumatic. Mechanical systems are not effective. Hydraulic systems are cheaper electric and pneumatic. They provide best of energy and quality indicators of technological process of tillage. Automatic control systems are uses draft forces, hitch position, depth of the implement, speed, acceleration and other sensors. Method of computer modeling and optimization of hydraulic automatic control systems of tillage units was developed. Results of computer modeling of hydraulic automatic control systems help to select direction of improving quality and energy indicators of technological process of tillage. Optimized combine implement depth and draft control system of arable unit allow reducing deviation the draft force of the plow; deviation of the depth of plowing is equal to or smaller than agro-technical requirements. Deviation of the draft force was decreased to 13.5 % for deviation specific soil resistance - 20 %, depth of plowing - 0.21 m, deviation of the depth of plowing - 0.019 m (9 %). Deviation of the depth of plowing may be decreased to 0.010 m (4,8 %), but deviation of the draft force shell be increased up to 16.2%. Optimized hydraulic automatic control system of garden tiller with a trapezoidal mechanism leaves smaller untreated soil area from 1.37-1.46 times.

The paper considers approach to optimization of automotive transport movements for transportation of billets, semifinished and finished goods between shop floors and warehouses of large machine-building enterprises. For the normal functioning of the production process a developed system of transportation and storage of billets, semi-finished and finished goods is needed. In large enterprises shop floors and warehouses are usually significantly separated in space and for transportation of billets, semi-finished and finished goods the automotive transport is used. Time needed to move of billets, semi-finished and finished goods between shop floors and warehouses in the enterprise is useless and increases production costs. Therefore, optimization of the movements of automotive transport when moving billets, semi-finished and finished goods between shop floors and warehouses will reduce the time of technological processes for products manufacturing produced by the machine building enterprise, and thus to optimize the production process. Thus, the search for the optimal route movement of automotive transport on the territory of the enterprise is a very important task. The problem of finding the optimal route is in the field of combinatorial optimization, as well as considered in the theory of operations research and is known under the general name as "traveling salesman problem". Traveling salesman problem is one of the transcomputational. All effective (reducing the exhaustive search) methods for solving the traveling salesman problem are heuristic. In most of heuristic methods not the most efficient route is obtained, and its approximate solution is a basic route. The next step is to improve the approximate solution. The article presents the results of a comparative analysis of a number of methods (algorithms) for solving the traveling salesman problem on the basis of which to solve the problem of optimization of automotive transport of large machine-building enterprises is proposed to use either the Little algorithm or ant colony algorithm. The statement of the problem of optimization of automotive transport movement during its work for manufacturing process of large machine-building enterprises is given, the procedure of calculations to solve the problem is shown, an example of solving a particular problem with the help of the developed "traveling salesman problem" procedure of calculation and the computer program (developed on Pascal in Delphi 7). The proposed approach to solving the problem of optimizing automotive transport movements during its work in the production process of large machine-building enterprises can reduce the time for transportation of billets, semifinished and finished goods between shop floors and warehouses, which means that it is possible to reduce the time of subsidiary operations, and as a consequence, increase productivity and reduce production costs. In addition, the reduction of the displacement route of automotive transport reduces the operating costs of automobiles maintenance.

Methane, as an alternative to traditional motor fuels, is the most perspective for the incoming decades of the current century. The most widely spread method of the modification of diesel engines for operating with methane is a conversion of a basic model by changing both the way of ignition - compulsory spark ignition instead of self-ignition by compression, and the method of power control - quantitative, with the help of a throttle in case of a gas version, instead of qualitative in a diesel version. The main task of such conversion is to achieve the best possible energy and economic performance of the engine. Moreover, the peculiarity of the operation procedure of the gas engine, the necessity to avoid detonation combustion, should be taken into account. Consequently, in the process of converting a diesel engine into a gas one manufacturers have to decrease both the compression ratio and boost pressure, which leads to decline in engine efficiency. The authors found out, that there is a potential possibility to achieve much better eco-nomic and power characteristics of gas engines by applying Miller cycle to the operation procedure. In this case it becomes possible having very high geometric compression ratio and corresponding high val-ues of gas expansion to obtain relatively low values of actual compression ratio. This is the value that can lead to detonation combustion. The program of calculating the characteristics of operation procedure of Miller-cycle gas engines was worked out. The authors suggested a system of calculation, according to which detonation behavior is estimated on the basis of actual data of a particular model of the engine. Due to such analyses of the particular model of the engine we found out actual maximum values of compression pressure and compression temperature, which do not lead to the onset of detonation. So it may be stated that the parameter value that significantly increases the overall efficiency of the Miller-cycle gas engine, created on the base of Kamaz engines, is found.