| 摘要 |
PURPOSE:To simultaneously attempt improvement of combustion, increase of output and improvement of thermal efficiency by attempting increase of the density of air through a process of efficiently decreasing the temperature of air to be filled in a cylinder when an exhaust valve is closed. CONSTITUTION:An exhaust turbosupercharger 8, a cooler 9, a first air passage composed of a scavenging chamber 7 for storing primary air and a second turbosupercharger composed of a compressor 10a, an intermidiate cooler 10b, an expander 10c and a turbine 10d for partially converting primary air branched downstream from the cooler 9 into low-temperature and high-density secondary air are provided. Moreover, the scavenging system is provided with a second air passage composed of a sub scavenging chamber for storing secondary air, a scavenging air introducing part 12 arranged in the part extended over two scavenging chambers, and communicated with scavenging holes, and provided with upper and lower scavenging air introducing ports communicated with the scavenging chamber, a scavenging pipe control valve 13 for opening and closing the scavenging introducing ports and an actuator 14 for operating the pipe control valve 13. |
