METHOD OF DETERMINATION OF ANGLE AT WHICH HPFP SECTION STARTS FUEL INJECTION

FIELD: motors and pumps.SUBSTANCE: invention relates to the field of testing and adjustment of diesel fuel systems. Proposed method for determining the angle at which high pressure fuel pump (HPFP) section starts fuel injection is that the HPFP is mounted on the bench, the fuel supply control rail is transferred to the position corresponding to the maximum feed rate and the HPFP cam shaft is rotated first in the direction of its rotation and then in the opposite direction. Determination of the angle at which HPFP section starts fuel injection is performed on the operating bench at a drive shaft rotation frequency of 70 min, according to the change in the value of the fuel pressure in injection chamber 1 mounted on outlet nozzle 12 of the HPFP section and equipped with pressure sensor 2. Moment of closing of inlet port 26 of the sleeve of HPFP section by the end of plunger 20 is recorded according to the moment when the fuel pressure in injection chamber 1 begins to increase relative to the value of the set overpressure therein. Values of the angles of rotation of cam shaft 14 corresponding to the opening moments of cut-off opening 37 (fuel cut-off point), when the upper edge of the cut-off groove of the plunger reaches the lower edge of the cut-off opening of the sleeve, are determined by the moment when the fuel pressure in injection chamber 1 is reduced to the set value. Value of the angle at which HPFP section starts fuel injection is determined as the difference between the average angle values over one hundred measurement cycles corresponding to the initial reference point and the moment of closing of inlet port 26 of the HPFP section sleeve by the end of plunger 20 when the pump shaft rotates.EFFECT: invention is aimed at automating the measurement process and increasing the accuracy of determining the angle at which HPFP section starts fuel injection.1 cl, 1 dwg Изобретение относится к области испытания и регулировки топливных систем дизелей. Изобретение направлено на автоматизацию процесса измерений и повышение точности определения угла начала нагнетания топлива секцией топливного насоса высокого давления (ТНВД). Предложенный способ определения угла начала нагнетания топлива секцией ТНВД заключается в том, что устанавливают ТНВД на стенд, переводят рейку управления подачей топлива стенда в положение, соответствующее максимальной подаче, и вращают кулачковый вал ТНВД вначале по направлению его вращения, а затем - против. Определение угла начала нагн