摘要
欧美国家对通用小型汽油机排放法规不断加严,目前中国生产的不同批次通用小型汽油机排放性能差异较大已是行业共有的技术难题.油气混合气浓度对通用小型汽油机排放影响很大,利用作者开发的通用小型汽油机进排气系统稳流试验台,对不同汽油机气缸盖进排气道、空滤器等进行稳流试验,对试验数据进行分析,得出进排气系统流通特性的差异和不同批次的生产波动是批量生产小型汽油机混合气浓度改变和排放性能差异的主要原因.研究结果还表明:通用小型汽油机采用压铸气缸盖,进排气道结构受压铸工艺的限制,流通系数偏低,影响发动机性能的提高,进一步提高进排气系统性能是优化通用小型汽油机性能的一个重要途径.
Euramerican laws for emission of non-road spark-ignition small engines become more rigorous continuously. Now, the great difference among the non-road spark-ignition small en- gines which is made in China of different batches has become the common technology problem in industry. The density of gas mixture exerts a tremendous influence on the emission of engine. Using developmental steady flow test rig for intake and exhaust system of non-road spark-ignition small engines, testing the intake and exhaust port in cylinder head, air filter and analyzing the test data, it was gotten that the difference of the flow character about the intake-exhaust system and the product waviness of different batches was the main reason for the change of density of gas mixture and the difference of the emission performance. The result shows that intake and exhaust port of such engines using casting cylinder head are affected largely by the casting technique, and the flow coefficient is low, which makes the engine performance hard to be improved. Improving the flow character of the intake and exhaust system is an important way to optimize the engine oerformance.
出处
《工程设计学报》
CSCD
北大核心
2011年第4期270-274,292,共6页
Chinese Journal of Engineering Design
基金
江苏省科技厅科技成果转化项目资助(BA2007086)
关键词
通用小型汽油机
进排气系统
流通系数
稳流试验台
排放
non-road spark-ignition small engine
intake and exhaust system
flow coefficient
steady flow test rig
emission
