Ocena mo?liwo?ci pomiaru przebiegu i dawki wtrysku za pomoc? indykatora z komor? o powi?kszonej obj?to?ci

摘要

Artyku? jest po?wi?cony pomiarom: nat??enia wyp?ywu paliwa z rozpylacza oraz dawki, podawanych przez wtryskiwacz silnika o zap?onie samoczynnym. Oceniono mo?liwo?ci wyznaczania przebiegu wtrysku pojedynczej i dzielonej dawki przy wtrysku do komory indykatora o powi?kszonej obj?to?ci. W pomiarach wykorzystano wtryskiwacz samochodu ci??arowego ?redniej ?adowno?ci. Przy ocenie wyników przyj?to, ?e ró?nice mi?dzy warto?ciami zmierzonymi a obliczonymi nie powinny przekracza? ± 4%. Tak wyznaczony zakres stosowania indykatora obejmuje dawki o obj?to?ciach od 10 do ok. 52 mm~3/wtrysk. Poza nim wyst?puj? przypadki obj?te dopuszczalnym przedzia?em b??du, jednak istnieje prawdopodobieństwo wyst?pienia pomiarów, których wynik nie b?dzie si? mie?ci? w przyj?tym przedziale.%The paper deals with measurements of the fuel dose and injection rate for a diesel engine injector. Possibility of measuring the single and multiple fuel injection rate was estimated. The investigations were performed for an electromagnetic common rail injector during fuel injection to the indicator chamber of enlarged volume. Such injectors are usually used in engines of medium carrying capacity trucks. The amplified pressure signal from the indicator was recorded by means of a digital oscilloscope. The equation for calculation of the injection rate results from the mass conservation law (2). For each measurement point (Tab. 1) the relative difference between the injection dose measured and calculated was determined (3) (Figs. 4, 6 and 10) for both single and multiple injection. The relative approximation errors were determined, too (Figs. 1 and 2). Comparison of the measured and calculated injection dose as a function of the rail pressure for both single and multiple injection is presented in Figs. 3 and 5. Fig. 7 shows the measured and calculated injection dose as a function of the dwell time for multiple injection. It was assumed that the differences between the measured and calculated values should not exceed ± 4%. Hence, the indicator should be used within the range of fuel supply from 10 for 52 mm~3/cycle. Outside the assumed range, the error can be less than or equal to ± 4%, but it also it can be greater.