Denso Corporation

Very High Pressure Solenoid Fuel Injection System

When American drivers think of diesel passenger cars, few would imagine the quiet and clean performance enabled by Denso Corporation’s Very High Pressure Solenoid Fuel Injection System. Denso combined vision, mechanical engineering, materials science, and software to build a sophisticated system capable of delivering the fuel economy of diesel, while meeting stringent emissions regulations and delivering the performance, drivability and NVH of a gas powered vehicle.

Denso, one of the pioneers in diesel common rail technology, set out to expand the market for diesel passenger vehicles that would be acceptable to very large numbers of negatively biased consumers, for example, drivers in the United States. Their vision was to use the benefits of very high pressure injection together with more economical “old technology” solenoid injectors. Thus Denso was able to meet OEM needs for a lower cost diesel system which is also emissions compliant. Denso’s ability to provide multiple injection events per cycle, along with precision atomization, effectively doubled the number of vehicles that can now pass the Euro-IV emissions test without the use of expensive diesel particulate filters.

In solving the challenges of managing 1800-bar pressures, Denso achieved their low cost objectives by using less expensive solenoid injection control, and by engineering a modular pump architecture that allows a high degree of commonality between 4, 6, and 8 cylinder applications, thus reducing incremental engineering effort. One element that especially impressed the PACE Judges was Denso’s use of computer technology to test each injector, store the results in a high density 2D bar-code, and “teach” the engine controller to use these data to optimize the performance of the total system – by compensating for injector-to-injector variation.

Denso’s Very High Pressure Solenoid Fuel Injection System can be seen on Mazda, Toyota, and Isuzu vehicles, and John Deere farm implements, with additional installations planned for the future.