| 摘要 |
PURPOSE: To enable the states of the inside of a combustion chamber (whether or not ignition has occurred, ignition timing, air-fuel ratio, etc.) to be detected with high precision. CONSTITUTION: A laser beam source 12 is made to emit a laser beam the wavelengths of which are selectively absorbed by gasoline. After the laser beam is made to pass through a space within a combustion chamber 5 by a pair of opposite optical elements 10, 11 arranged to face the inside of the combustion chamber 5, it is introduced into a photoelectric conversion element 14. Since the laser beam is absorbed depending on the concentration of gasoline present in the space between the pair of optical element 10, 11 and thus the intensity of the transmitted beam impinging on the photoelectric conversion element 14 varies, the concentration of gasoline in the mixture, i.e., the air-fuel ratio within the combustion chamber 5 can be detected through the detection of this variation. Also, since the air-fuel ratio is suddenly leaned by ignition, the observation of variations in the air-fuel ratio allows determining whether or not ignition has occurred. Also, ignition timing and ignition delay can be detected through the detection of a crank angle position at the time of ignition. |
