Practical Feasibility of Measuring Pressure Waves in Common Rail Injection Systems by Magneto-Elastic Sensors

In modern Common Rail injection systems five injections per combustion cycle are state of the art and this number trends to increase. Due to the fast opening and closing of the injectors pressure waves are excited on the pipe between rail and injector. These pressure waves influence the amount of injected fuel mass of subsequent injections. A non-invasive pressure sensor is introduced which allows to measure the pressure on the pipe with little effort and costs. With this sensor it is possible to measure the frequency and, with some limitations, the amplitude of the oscillations. Based on the information delivered by this sensor fuel mass deviations caused by the pressure waves may be compensated in series production vehicles.