One of the ways to increase the fatigue strength and wear resistance of parts is defamation of the surface layer of the working surfaces of the parts as a whole and in stress concentration zones. Plastic deformation takes place when the load increases, which is higher than the elastic strength of the material, as the metal strengthens during the deformation process. The bulk of industrial alloys have a polycrystalline structure. During the deformation of polycrystals, there is no sliding stage, the deformation of the grains begins immediately along several sliding systems and is accompanied by bending and twisting of the sliding planes. The total deformation is small and amounts to 1%, the grains are deformed heterogeneously due to their different orientation in relation to the applied loads. As the deformation changes, the difference between the grains of the material decreases and the microstructure changes: the metal grains are gradually pulled out in the direction of the plastic flow, which leads to a change in the grains of the crystal lattice of the metal with an increase in the density of defects. The reliability of machine parts primarily depends on their strength, wear resistance, vibration resistance, heat resistance, etc. These criteria for the reliability of machine parts are provided by various methods and measures during their manufacture, such as: material selection and various methods of increasing strength and wear resistance - heat treatment, treatment by various physical methods of the surface of the part and areas of stress concentration, etc. The introduction of modern methods and tools in the development of mechanical engineering ensures an increase in the reliability of parts and products in general, as well as a reduction in the cost of production. This article analyzes the types and designs of known vibration equipment and vibration exciters used in mechanical engineering. The structural diagram of vibration equipment production is considered. Determination of the main advantages and disadvantages of vibration equipment and vibration exciters.

Annual emissions of more than 6 million tons of pollutants and carbon dioxide into Ukraine. Mostly polluting industrial enterprises. However, with the increase in the number of cars on the roads, the number of harmful emissions into the atmosphere has increased. Over the past few years, the amount of exhaust gas entering the air in major cities has increased by 50-70%. More than half of the pollutants are emitted by private cars: in 2019, 1.7 million tonnes of harmful substances fell on them, while the total amount of all car emissions was 2.3 million tonnes. This article highlights the problem of environmental pollution by the exhaust gases of diesel internal combustion engines. Ways to improve environmental performance are presented. The composition of the exhaust gases and their effects on the environment are analyzed. The standards of Euro - 1 Euro - 6, on the reduction of harmful substances in diesel fuel are considered. The modern environmental standards of Stage and Tier and the regulation of smoke by standards are given. A formula for the determination of harmful substances in the exhaust gases of cars and a formula for the determination of the smoke of gases are proposed. The ways of neutralizing the toxicity of the exhaust gases with the help of neutralizers and the reduction of soot by means of the diesel particulate filter are considered. Common Rail DRNR systems, EGR and Selective Neutralization (SCR) systems using Adblu reagent, its advantages and disadvantages are described. The comparative characteristics of EGR and SCR systems are presented. Gasoline engines are not considered in this article.

Mechanization of labor on small farms and individual farms is a very important issue of modern agriculture. The use of small agricultural machinery with a capacity of up to 16 kW is quite relevant today. Small-sized machinery is divided into: small 4-wheeled tractors, 2-wheeled motoblocks, cultivators, machines and equipment. With the help of this technique perform various agricultural and other types of work in crop production, horticulture, gardening on small plots, livestock and more. Despite its rather small size, small equipment also has various mechanisms that fail over time. Most often, the parts of the internal combustion engine fail. In general, the cost of repairing the internal combustion engine during operation may exceed the total cost of the engine by 5-6 times. Thus, there is a question of improving the system of technical service of engines of small tractors. This article considers the issue of increasing the efficiency of operation of internal combustion engines for small tractors, due to the effective conduct of after-sales or post-repair running-in and improving the maintenance system. Types of small-sized equipment are presented. The analysis of possible loading and speed modes of cold and hot running-in of internal combustion engines and means for their realization is carried out. Technical means for running-in and testing of internal combustion engines are analyzed. The following formulas are given for determination: smoke of exhaust gases at running-in of engines; light transmission of exhaust gases; speed control range; load torque; the content of harmful substances (Q) in the exhaust gases on the j-th components. The necessity of bench running-in of engines of small-sized agricultural machinery is substantiated. The functional scheme of the stand for running-in and testing of internal combustion engines is considered. The stages of cold and hot running-in of small-sized engines are described. With the help of the received information, the results are made and the analysis of methods of running-in of internal combustion engines of small-sized agricultural machinery is carried out.

It is known that when processing plastic materials by cutting, chip grinding is a serious problem. The formation of a stable, strong draining chip is a sign of low machinability of the material of the part and requires the use of special means and methods that would ensure the separation of the chip or allowance that is cut. This issue is especially relevant in the case of cutting drawing as a low-speed process, which is characterized by intensive overgrowth and a high coefficient of chip shrinkage, and therefore the strength of the latter. Today, there are a number of original developments of several scientific schools, which implement the idea of preliminary division of the allowance during drawing by creating a network of technological chip-splitting grooves. The process of internal drawing, in particular drawing of round deep holes, must necessarily take place under conditions of forced chip separation or allowance. At the same time, the so-called transverse division of the chips, i.e., division along the perimeter of the hole, is usually carried out due to structural elements on the broach teeth and today is not too difficult a problem. However, there are certain reserves in this direction as well, in particular those related to increasing the stability of the tool. This article considered the technological function of the reliefs, which consists in the forced division of the cut allowance with contour grooves. An analysis of the advantages and disadvantages of the most common processes for obtaining round holes in hollow blanks and parts is carried out. The essence of the group (progressive, variable) stretching scheme is described. Typical combined extension tools are considered. Given formulas for calculating the dimensions of chip grooves. The first component р of the change in the diameter of the hole and the outer diameter of the workpiece after each of the combined drawing operations is characterized.

The mechanics of chip fracture when cutting the allowance of pre-divisible technological grooves was studied for the first time, and the relationship between the profile and depth of the latter and the characteristics of the stress-strain state in the chip formation zone (relative shear, chip shrinkage, shear angle, front angle, contact processes . This article discusses a more complex problem - the longitudinal division of chips or allowance. Most researchers are inclined to believe that this problem should be solved by pre-dividing the allowance by a network of special chip-splitting ring or screw grooves. The depth of these grooves should be 0.6… 0.95 of the amount of rise on a single tooth of the broach. The results of the study of the mechanics of chip destruction are described when the tool meets the process groove in the drawing process. The connection between the structure of the pipe and the intensively deformed state in the zone of chip formation is shown. From the obtained results the following follows. Preliminary deformation hardening by means of deforming drawing allows to increase hardness of OM twice (steel 10), to 60% (steel 35), to 50% (steel 45) and to 25% (aluminum alloy AK6). This significantly reduces the shrinkage coefficient of chips (respectively 2; 1.4; 1.4 and 1.3 times) and the actual previous angle (at a sharpening angle γ = 15⁰, respectively: from 36⁰ to 18⁰; from 25⁰ to 17⁰; from 21⁰ to 16⁰ and from 22⁰ to 17⁰). All this indicates a decrease in the intensity of the cutting process with increasing intensity of the previous HPD The following minimum values of the groove profile angle for the investigated materials 2φmin were determined: 80⁰ (steel10); 60⁰ (steel 35); 50⁰ (steel 45 and alloy AK6). It is established that the minimum depth of the chip-splitting groove hC is determined from the condition of chip destruction when the tangential stresses in the shear zone are exceeded above the shear resistance of the processed material. The following values of the minimum depth of the chip-splitting groove for the studied materials were obtained: hCmin = (0.4… 0.55) Sz - steels 35 and 45; hCmin = (0.55 (0.6) Sz - AK6 alloy.