직접 분사식 가솔린 인젝터의 내구 평가 시스템 개발 = Development of Durability evaluation system for injectors in direct injection gasoline engines

다국어 초록 (Multilingual Abstract)

The performance and efficiency in gasoline engines have been improved by adopting direct fuel injection system, and the fuel injection pressure is demanded to keep increasing in order to improve the atomization of fuel and in-cylinder mixing characteristics. Recently, the fuel injection pressure increased up to 200 bar and more. Therefore, various evaluation systems are needed for development of high pressure fuel injector. One of them is durability evaluation system. In this study, a new system has been developed. This system can evaluate injectors at the similar engine operating conditions. This system is able to control fuel temperature from 35 to 80.... injection pressure up to 250 bar, and operate injector at the engine speed of 40,000rpm maximum. Moreover, this durability evaluation system is equipped with an emergency function, which can detect the unexpected increase in temperature and pressure and stop the system. High pressure injectors of GDI engine were evaluated with this system. Static flow rate, dynamic flow rate, and leakage of the injector were analyzed at the before and after of durability evaluation. As a result, it is possible to evaluate a high pressure injector of a direct injection engine with this system.