| 摘要 |
PROBLEM TO BE SOLVED: To perform a precise detection by mounting an air-fuel ratio sensor for detecting the air-fuel ratio of burnt gas and controlling fuel injection quantity so as to have an intended air-fuel ratio on an engine side member made of a material different from the sensor. SOLUTION: An air-fuel ratio sensor 73 arranged within a reaction chamber 71a has a detecting part 73a arranged in a right-angled direction to a cylinder shaft and provided on the tip, a male screw part 73g and a polygonal engaging part 73d provided in the middle part, and a harness 73b formed of a hater power supplying power source line which is drawn from the upper end, and the harness 73b is connected to a battery power source and a control device. The reaction chamber 71a is allowed to communicate with the cylinder through a throttle part 71b, a gas passage 71c, an exhaust gas inlet passage 75a within a heat insulating pipe 75, and an exhaust gas inlet port 81. The pipe 75 is formed of stainless steel, ceramics or the like having a heat conductivity smaller than aluminum material, and buried in a boss thick part 22c formed so as to pierce through a water cooled jacket 76. |
