Vol 7, No 4 (2021)

The influence of cut’s depth on residual stresses distribution and an endurance limit under bending of hollow cylindrical specimens made of steel 20 with external diameter 50 mm and interior diameter 40 mm after outstripping superficial plastic deforming by roller strengthening of two regimes has been examined. It’s been stated that the value of compressive residual stresses in a dangerous section of specimens decreases on cut’s depth increase. As a result, an endurance limit increment of hardened specimens with cuts diminishes. In order to preserve the effect of hardening by increasing the endurance limit under outstripping superficial plastic deforming with an increase in a cut’s depth, it is necessary to increase the thickness of a smooth part with compressive residual stresses layer. It’s been shown that in order to estimate the increase in the endurance limit of hardened specimens, one should use not residual stresses at the bottom of a cut, but average integral residual stresses through the part’s dangerous section surface layer thickness that equal a critical depth of a non-propagating fatigue crack.

Purpose of work: the purpose of the work is to improve the accuracy of fuel dosing during cyclic supply and reduce toxic emissions of exhaust gases into the atmosphere of an internal combustion engine. The method relates to power and transport engineering and is intended for ground-based power plants and vehicles. The method consists in cyclic fuel supply through the injectors, while measuring the fuel pressure at its inlet during the calibration work of the internal combustion engine electronic control system, by measuring the fuel pressure in front of each injector, the integral value of its drop during the open state of the valve of each injector is determined, depending on crankshaft speed and load on the internal combustion engine and record it in the non-volatile memory of the electronic control unit of the internal combustion engine, and during its operation, before opening the valve of each injector, the fuel pressure at its inlet is increased by the corresponding integral value of its drop during the valve open period injector recorded in the non-volatile memory of the electronic control unit. Due to the correction of the fuel pressure in front of the injector and the correction of the cyclic fuel supply of each individual injector, the accuracy of its dosing is increased, which reduces the toxicity of the exhaust gases of the internal combustion engine.

The purpose of the work is to increase the stability of the process of movement and braking, as well as to increase the wear resistance of the equipment of the locomotive and the rail track, by developing and improving adaptive systems that maintain optimal adhesion of the wheel to the working surface of the rail.

The theoretical conclusions obtained and the results of model studies show the effectiveness of the proposed adaptive control method for adaptive systems and the possibility of building a simple microprocessor control system for the brake and sand feeding, supplementing the regular system of the locomotive, aimed at eliminating the loss of adhesion.