전자 제어 연료 분사 방식의 4행정 50㏄급 소형 이륜차 엔진 개발

In recent years, the applied engineering solutions in small engines have been extended down to 50 ㏄ displacement engines to satisfy the more stringent emission regulation and increasing customer demands. The existing small engines, such as air-cooled 2 stroke or 4 stroke engines with carburetor system, have to enhance their mixture preparation and also have to call for the implementation of enhanced engine technologies into small engine category, which is as well known for automotive applications. In this paper, water-cooled 4 stroke 50 ㏄ small engine with electronic control fuel injection system were developed to enhance fuel economy and to meet EURO Ⅲ emission regulations. The engine power of 4 stroke with EMS was equivalent to 2 storke engines while the maximum torque increased due to extended engine speed. In the CVS 40 mode test, more than 50% enhancement of fuel consumption rate compared to carburetor system was obtained with lower emission level due to accurate closed loop air fuel ratio control.