Delphi Launches Electronic Unit Pump For Heavy-Duty Diesel Engines.
Following the hunch last month of its E1 Advanced Fuel System featuring an electronic unit injector (EUI) with the actuator incorporated into the body of the injector (see September 2000, Diesel Progress), Delphi Diesel Systems announced a new electronic unit pump, the EUP 200. Whereas the E1 is a self-contained unit integrated into the engine cylinder head, the new EUP 200 pump is sited remotely from the injector and is therefore particularly suited to engines with cylinder block mounted camshafts.
The new pump is offered as an alternative to the electronic unit injector and is essentially the same technology. The individual EUP units, one per cylinder, are driven from an additional lobe on the camshaft and are arranged along the engine to allow for short equal length high-pressure pipes between the EUP and its corresponding injector.
Like the EUI, each injector is fed fuel by an actuator situated in the body of the EUP. This actuator is controlled by an electronic control unit (ECU) which receives continuous signals from various sensors situated around the engine. This precisely parallels the working method of the EUI in that the information received is compared with optimum values stored within the ECU memory. The appropopriate signal is then sent to the actuator, enabling it to deliver the precise amount of fuel at the exact timing point required by the engine.
The EUI and EUP strategies accommodate the two basic types of camshaft location positions currently found on diesel engines. While overhead camshaft engines are generally more efficient, low camshaft engines are chosen for various reasons -- primarily where a low engine profile is required. The EUP 200 system is Delphi's response to this market demand.
The system has a peak injection pressure of 29,000 psi to enable engines to meet emissions regulations. That peak pressure has the effect of atomizing the fuel into finer droplets which promotes a better fuel-air mixture and more efficient combustion. Delphi pointed out that the system enables the engine comfortably to meet US. Tier 2 and Euro III emissions regulations, with a potential for Euro IV.
One advantage in favor of the EUP approach is that although both models of fuel injection system can be developed to suit the respective engine type, the EUP is more readily applied to existing engines because the majority of the fuel systems are remote from the cylinder head.
The EUP 200 comes in two models, with respective plunger diameters of 10 and 11 mm and strokes of l7 and 18 mm. These are suitable for engines with capacides up to 2.5 L per cylinder, Delphi said. Like the El Advanced Fuel System, the EUP 200 system can be designed for injection rate shaping using two-stage lift and pilot injection, as well as cylinder balancing for idling and low load refinement. Full diagnostic capability is also provided.