Denso develops new common-rail diesel system with world’s highest injection pressure

Kariya (Japan), June 26, 2015: Global automotive supplier Denso Corporation has developed a new diesel common rail (DCR) fuel injection system with the world’s highest injection pressure of 2,500 bar. Based on the company’s research, the new system can help increase fuel efficiency by up to 3 percent while also reducing particulate matter (PM) by up to 50 percent and nitrogen oxides (NOx) by up to 8 percent. This is compared to Denso’s previous generation system. The new DCR system will be launched later this year on passenger, commercial, agricultural and construction vehicles worldwide.

“Our new diesel common-rail system will help increase fuel efficiency and meet exhaust emissions standards that are becoming increasingly stringent around the world, particularly in Europe, Japan and the United States,” said Yukihiro Shinohara, executive director responsible for Denso's Diesel Engine Business Unit.

Improved design structure to decrease workload of fuel pump

In a common-rail system, a portion of the fuel delivered from the fuel pump to the injectors is used for purposes such as lubricating system components. That fuel is then returned back to the fuel tank, which puts an additional load on the fuel pump, instead of being injected into the engine combustion chambers.

By improving the design structure of the injector, fuel pump, and common-rail, Denso says it has significantly decreased the workload of the fuel pump by reducing the amount of fuel that was sent back to the fuel tank by about 90 percent.

Higher Injection Pressure

To generate a higher fuel injection pressure, the supplier redesigned components and used new materials. These changes allowed the fuel to atomise into finer droplets, which improved fuel ignition and combustion efficiency, resulting in increased fuel economy and cleaner exhaust emissions. Denso says it has been able to engineer and manufacture a fuel pump that is similar in size but more efficient than the previous system. This was done by reducing the workload of the fuel pump.

Denso is now working to develop and commercialise a 3,000 bar diesel common-rail system.