After the scandals around the fake emission values in recent months car builders have to ensure real engine efficiency and low emissions throughout the vehicle’s life. Especially in the highly dynamic driving conditions of the next emission regulations and real world driving.
One way to improve efficiency and reduce the release of harmful emissions is through more precise control of the fuel injection system. Diesel injectors can spray fuel up to 10 times during each engine cycle, so very precise control of each individual injection event helps further improve fuel economy and reduce emissions as well as engine noise over the life of the engine.
UK automotive parts manufacturer Delphi developed an injector closed-loop control technique involving hardware and a software control strategy to maintain maximum injection performance over time. The technique relies on an additional electrical wire inside the injector that uses a needle as an “electrical switch”, as the company told. This process offers real-time control data that is more precise and more cost-effective than other existing closed loop solutions.
By sending an electric current through the needle, the system detects when the nozzle needle touches the seat, the lift stop or is traveling in-between. This process allows the system to constantly recalibrate all fueling events over the lifetime of the vehicle as well as compensate for any part-to-part variation.
Combining the electric switch technology with a new control strategy creates a solution that maintains multiple injection accuracy. This function works independently of injection and combustion settings, as well as complex engine or drivetrain designs.
According to Delphi, the integration of the switch in the injector and the new strategy in the Electronic Control Unit allows to provide an emissions-lowering solution to a difficult engineering challenge.