| 摘要 |
PURPOSE:To realize knocking detection with high accuracy, by detecting in an AC way the responsive working of a magnetic diaphragm to the cooling water pressure and then detecting only the pulsating pressure corresponding to the knocking. CONSTITUTION:A magnetic diaphragm 202 is vibrated and displaced with application of the composite pressure of the pressure of the static cooling water and the pulsating pressure of the cooling water according to knocking. Thus a gap G between the diaphragm 202 and a center magnetic path 206 varies. As a result, an AC type change is caused to the magnetic flux produced at a magnetic path comprising a magnet 203, a magnetic matter 205, the diaphragm 202, the magnetic path 206, a magnetic matter plate 204, etc. Thus only the AC displacement corresponding to the pulsating pressure of the diaphragm 202 is detected via a coil 207. Then only the AC component corresponding to the pulsating pressure is detected. In such constitution, the knocking is detected with high accuracy. |
