| 摘要 |
FIELD: mechanical engineering; internal combustion engines. ^ SUBSTANCE: invention is designed for determining condition of internal combustion engine. According to proposed method, piston speed and acceleration are determined and indicator diagram of force acting onto piston is plotted, depending on angle of turning of crankshaft journal around its axis of rotation, or heat characteristics of internal combustion engine are taken and, basing on heat calculations, indicator diagram stated above is plotted and then inertia forces of reciprocating masses of piston and crank gear of each cylinder on internal combustion engine are determined depending on acceleration or deceleration of piston. Pressure of fuel combustion products onto piston is measured, and changes of pressure of combustion products onto piston depending on angle of turning of crankshaft journals are determined and, with due account of measured values of pressure, value of forces of reciprocating masses of piston and crank gear of internal combustion engine in direction of cylinder axis are determined and indicator diagram is plotted after which, for each turn of crankshaft, mean summary tangential force (Tm) acting onto crank depending on torque (Mtm) on crankshaft is determined: Tm=Mtm/R where R is radius of crank of crankshaft. Then mean summary forces along axis of piston and crank gear P∑ are determined depending on angle alpha of crankshaft turning and angle beta of deflection of connecting rod from cylinder axis P∑=Tm/Sin(alpha+beta)/Cosbeta. Basing on obtained results, for each half-turn of crankshaft summary value of tangential force on crank of crankshaft, summary value of pressure of combustion products of fuel mixture in cylinder, and summary inertia force of reciprocating masses of piston and crank gear for each cylinder are determined as difference between mean summary forces P∑ for mean summary tangential force Tm and summary pressures of combustion products of fuel mixture depending on angle of crankshaft turning, after which flywheel is installed on engine shaft and rotation of crankshaft at constant angular velocity is provided. Size of flywheel is determined to provide summary antitorque moment to crankshaft rotation equal to summary torque of acceleration of crankshaft under action of summary inertia force calculated as stated above. ^ EFFECT: increased efficiency of engine and its service life by optimization of operation conditions of internal combustion engine. |
