Sensing Fuel Injection Start and Stop Timings of Diesel Solenoid Injector Using Photo and Shock Sensors

The start and end timings of a controlled fuel injection in a diesel solenoid injector were measured using photo and shock sensors. The photo sensor was installed near the tip of the injector nozzle to measure the spray. The shock sensor was installed outside the injector body to detect the movement of the injector needle. It was confirmed that the fuel injection start timing could be accurately measured by both the photo and shock sensors, while the fuel injection end timing could be measured only by the photo sensor. Two types of fuel injection patterns, namely single and pilot injections, were investigated. In the single injection, the fuel rail pressure was controlled at values of 45, 75, and 105 MPa. On the other hand, in the pilot injection, the pressure was set to 75 MPa. To aid in the statistical processing, the measurements were repeated 35 times under one experimental condition. For the uncertainty analysis, a normal distribution was assumed for the error distribution function.