| 摘要 |
PURPOSE:To easily detect whether a fault exists or not, by detecting ignition and explosion sounds of each cylinder by an acoustic pressure detector, and displaying them together with a periodical signal of an engine. CONSTITUTION:An acoustic pressure detector 7 is prepared by providing a plate 3 so a to be opposed to a sound receiving surface 2 of a moving coil 1, fixing a probe 4 to the plate 3, and forming a structure which has fixed the adjacent part of the base part of the probe 4 to a housing 6 so that it can be vibrated microscopically by an elastic body 5. A pulse output of the primary side of an ignition coil 10 is detected, is amplified by a buffer amplifier BUF1 and an amplifier AMP1, and after that, is displayed on a CRT. On the other hand, ignition and explosion sounds to be transferred are detected by bringing the acoustic pressure detector 7 into press-contact with the outside wall of the cylinder, are superposed on the display of an ignition coil output signal and are displayed on the CRT through a volume 12, a buffer amplifier BUF2 and an amplifier AMP2. |
