筒内噴射ガソリンエンジン用バッテリ電圧駆動インジェクタの開発 : 第1報, バッテリ電圧駆動方法と駆動条件変化への対応 : 機械力学,計測,自動制御

The conventional fuel injector for direct-injection gasoline engines is driven by voltage step-up circuitry and current control circuitry. The voltage step-up circuitry boosts the battery voltage to near 100 volts. This conventional system is fairly large and a more compact system is preferable. We have developed a mass producible battery-voltage-driven fuel injector for direct-injection gasoline engines. The injector has a dual-coil structure that enables the injector to operate at the battery voltage, thus eliminating the need for either voltage step-up circuitry or current control circuitry. Deviation in battery voltage and changes in harness resistance are fully compensated through opening-coil energization-time control. In addition, with this control method, the injector can be used with a wide range of fuel pressures. In this paper, the design concept and the dynamic characteristics of the battery-voltage-driven fuel injector with a dual-coil structure and the opening-coil energized-time control method is discussed in detail.