The New Denso Common Rail Diesel Solenoid Injector

The new-generation of solenoid injectors equipped with pressure-balanced pilot valves for energy saving and dynamic response improvement

“…21, where the forces were evaluated with the electromagnetic submodel given by Eq. (6). The determined force values are in line with those found in the literature [12].…”

“…A high-pressure pump driving power of more than 1 kW can be induced by injector static leakages for a 4-cylinder engine running under a nominal rail pressure close to 2000 bar. These pressure levels can occur in the low end torque area or at rated power conditions [6]. In general, it has been shown that, thanks to the injector clearance leakage reduction (injector clearance leakages include pilot-valve static leakage, static leakage at the sliding control piston and static leakage at the sliding needle), about a 1% fuel consumption diminution is possible for both passenger car and heavy duty applications over the whole map area [7].…”

“…In fact, the pressure can easily be maintained in the rail for several minutes after the engine stops, and the fuel for the injectors becomes available directly from the rail for the next startup. Furthermore, the increase in injector clearance leakages can augment the risk of fuel deterioration, due to the high local temperatures in the fuel return lines [6]. Finally, a control of injector leakages is mandatory in order to increase the maximum pressure level beyond 2000 bar [7].…”

“…The pressure-balanced pilot-valve, which has been introduced recently into solenoid injectors [12], is an effective way of accomplishing these objectives in terms of reduced fuel static leakage and multiple injection control. Different injection apparatus suppliers, such as Denso [6], Delphi [13] and Bosch [12], have recently proposed new generation solenoid injectors with pressure-balanced pilot valve layouts. However, there is still a lack of data and analyses in the scientific literature about this innovative typology of injectors.…”

Comparison of the Emissions, Noise, and Fuel Consumption Comparison of Direct and Indirect Piezoelectric and Solenoid Injectors in a Low-Compression-Ratio Diesel Engine

“…In this regard, not only can the particular driving technology (piezo or solenoid) play an important role, but also the hydraulic layout and the mechanical setup of each injector [19]. If a solenoid-driven injector features an innovative pressure-balanced pilot-valve layout, its static leakage can be reduced significantly, by up to 25% less than similar injectors featuring standard pilot valves [20,21]. Moreover, a further reduction, of up to 50%, may be obtained if the innovative pressure-balanced pilot-valve is coupled with an integrated Minirail [22].…”