Commatoze

Got this off of today's Autotech Daily, and thought I'd share it....


BOSCH PIEZO COMMON RAIL INJECTORS CAN HELP CUT EMISSIONS 20%
Robert Bosch GmbH says its new piezo common rail diesel injection system lowers emissions within an engine by up to 20% vs. current solenoid or competitive piezoelectric injectors. The supplier is launching the technology on the V-6 equipped Audi A8 this fall. The system is Bosch’s third generation common rail injector and the first to use piezo actuation. Previous designs used a magnetic coil with a piston rod transmitting the hydraulic force required to open or close the injector to the nozzle needle. Rival Siemens VDO Automotive, which introduced such technology two years ago, is the only other supplier to offer piezo actuation, although Delphi and Denso plan to do so in coming years. With piezo systems, a package of several hundred tiny crystals is placed in an electrical field. The rapid expansion of the crystals results in actuation in less than ten-thousandths of a second—half the time required by a magnetic switch. In Bosch’s inline injector, the actuator is integrated into the injector body, and the movement of the piezo package is transferred to the nozzle needle without mechanical parts or friction. The design provides more precise dosing and an improved atomization of the injected fuel mixture within the combustion chamber vs. solenoid and other piezo injectors, according to Bosch. And a higher switching speed of the injector means the intervals between individual fuel injections can be reduced and controlled more precisely. Bosch says one or two pre-injections of fuel prevent the emission of white and blue smoke just after a cold start. A supplementary injection immediately after the main event lowers soot particulates, and a further injection can regenerate particulate filters. In addition to lower emissions, Bosch’s latest common rail system promises to reduce engine noise by 3 dB at startup and boost engine output by up to 7%. Fuel economy also is improved because the return flow of fuel that is not required for injection is very small for an inline injector, the supplier claims. This allows engineers to reduce the delivery rate and the energy requirement of the high-pressure pump. In a common rail design, returned fuel is generated by the dissipation of the energy used to pressurize the rail. While optimizing other aspects of the system, Bosch chose to maintain the 23,200 psi pressure rate currently used on the solenoid-based second-generation unit for the new piezo actuator. The increased hydraulic speed of the system comes from the closeness of the piezoelectric actuator to the nozzle needle in the injector tip. Through integration, engineers also were able to cut the number of moving parts on the nozzle from four to one and the system’s moving mass by 75%. Bosch expects to introduce a 26,100 psi unit in 2005 and possibly boost this to 29,000 psi a year later. The supplier plans to produce 300,000 inline injectors next year and 2 million units in 2005. Already under development, Bosch’s fourth-generation system features a variable injector nozzle. Existing injectors use a single line of five to seven nozzle holes and a single switching stage to distribute the fuel in the cylinder's combustion chamber. The variable nozzle has two lines of nozzle holes that can be activated in two steps for more precise fuel delivery.

CCM591

Very interesting. Sounds promising! Thanks for posting.

dodgeman01

sounds $$$$$$$ there goes Cummins being the cheapest to BOMB :-
DM01

MCummings

Um, Italy had this technology, and had widespread use when the '98.5 ISB was introduced here in the States.

The motors they are using over sea's now make the ISB-e look like a Ford 6.9 IDI.

Merrick

Holsteinman

Sounds cool, but $$$