Common Rail System

Friday, November 28, 2008

The purpose of the MCM Common Rail System Bench, is to actuate a complete diesel common rail fuel system as it would on the engine and measure its performance. As this machine was designed for product development, it is also capable of mapping all of the fuel system to reveal problem areas of operation. Measured parameters for six injectors are discharge (up to five splits), reaction time, bypass flow, bypass temperature and bypass pressure. Measured parameters for pumps are speed, output flow, output pressure, bypass flow, bypass temperature and bypass pressure. Typical calibration fluid is Viscor 1487 (ISO 4113)

A common rail, diesel fuel system is different from a unit injector fuel system in that the high pressure required at the nozzle of the injector is provided by a pump and maintained in a cast iron vessel called a rail that feeds each of the injectors in the fuel system. Each injector is individually fired to allow the pressure from the rail to reach the tip of the injector. This high pressure fuel overcomes the spring on a check and exits the injector as atomized fuel into the engine cylinder. Our machine measures the discharge from the injector and the time from the moment the solenoid is commanded to the moment that the discharge is detected.