# Effects of Valve, Armature, and Armature Pin Guidance on Diesel Injector Performance
## 3 Results and Discussion
### Injector Function Results
Because backflow occurs in the injector even when there is no energizing, the majority of it depends on the flow between the armature and armature pin. This finding aligns with the study by [PERSON] et al. (2020) regarding backflow during the static state. The increase in injector spray amount as the clearance between the armature and armature pin increases is attributed to higher backflow rates, resulting in earlier needle rise and prolonged needle opening during the  
Figure 12: Backflow rate results comparison of injector experiment vs. simulation at _maxP_. defined time interval. Consequently, increased clearance between the valve, armature, and armature pin leads to increased injection amounts. This phenomenon primarily occurs because of the accelerated deterioration of hydraulic pressure balance and the extended needle opening time within the triggering period arising from the earlier rise of the injector needle. The injection amount is influenced by three key factors:  
* armature opening closing time;
* injector needle opening and closing time;
* nozzle hole flow amount. The opening and closing times of the armature are influenced by factors such as the clearance between the armature and armature pin, magnetic trigger timing, armature geometry, and the spring force acting on the armature. Except for the armature and armature pin, all factors and sub-parts remain constant. The impact of the clearance between the armature and armature pin on the injector spray and backflow rate has been previously analyzed. The closing time of the armature is evaluated in Figures 13 and 14. The opening and closing times of the injector needle depend on the valve, armature, armature pin, backflow amount, needle geometry, and spring force acting on the needle. Similarly, all variables except the valve, armature, and armature pin are considered constant. Figure 14: Armature closing time at _minP_. Figure 13: Armature closing time at _maxP_. Figure 13 reveals negligible variance in armature closing times among groups 1, 2, 3, and 4 at _maxP_. However, in the fifth group, characterized by the highest clearance between the armature and armature pin, the armature closing time also reaches its peak. This occurrence is attributed to the armature elevating earlier owing to the same magnetic trigger initiation. Subsequently, upon completion of magnetic triggering, the armatures across all groups revert to their original positions simultaneously, driven by the spring force. Notably, an armature that opens earlier remains open for a longer overall duration. In the sixth group, the closing time of the armature was prolonged in two injectors, deviating from the norm. This deviation could be attributed to variations in the physical properties of the magnetic coil or a partially premature trigger initiation. Further investigation is needed to elucidate this result, potentially forming a basis for subsequent studies. Figure 14 reveals that the armature closing time in the fifth group at the _minP_ value is shorter compared to the _maxP_ value. This discrepancy arises because of the reduced back pressure force exerted by the fuel on the armature at _minP_ compared to _maxP_. During the initiation of triggering, the fuel pressure force propels the armature upwards, and upon triggering cessation, the armature swiftly returns to its closing position. Consequently, the total duration of openness is abbreviated. The data presented in Figure 15 illustrate the duration required for the injector needle to overcome the spring force and reach its fully open position. This metric is crucial for assessing the influence of components beyond the valve, armature, and armature pin, such as nozzle geometry and needle spring force, during the period following the disruption of hydraulic balance. The durations depicted in the figure exhibit proximity across all groups. As previously mentioned, the specialized production, measurement, and control of sub-parts, excluding the valve, armature, and armature pin, contribute to this outcome.