Study on the Influence Factors of Common Rail System´s Injection Mass

The injection mass of common rail system is determined by rail pressure and injector energizing time. Under different rail pressure, single injection experiments have been performed; under the same rail pressure two injections (preinjection and main injection) tests with various intervals have been carried out. According to the analysis of the results, find that at the start-up and stop stages the injection rate becomes faster with increasing rail pressure and the injection characteristics for common-rail system tends to rectangular jet. When the rail pressure is low, the needle valve has slow response, and the effective flow area of the injector greatly influences the jet law. When the rail pressure is improved, the valve´s response speed will be increased remarkably and the injection rate is mainly affected by the rail pressure. During multiple injections the needle valve lift has affected on the mass of the main injection more than the rail pressure fluctuations caused by pre-injection.