| 摘要 |
PURPOSE:To enhance reliability with respect to noises without a bandpass filter, by sensing the vibration of a tuning fork vibration having a resonant frequency which is approximately equal to the knocking frequency. CONSTITUTION:A case 41 is attached to the main body of the internal combustion engine by a screw part 41a. 43a and 43b which are soldered by silver are tuning fork leads and 43c is a tuning fork base. The tuning fork base 43c is fixed to the case 41. Strain sensors 42a and 42b, which transform mechanical strain to an electrical signal are bonded to the surfaces of tunig fork. 45a and 45b are terminals comprising a conductor. 46 is an insulating material which insulates said terminal from the case 41, and is surrounded and fixed by a cup shaped open edge 41b of the case 41. The engine vibration at the time of knocking is transmitted to the case 41, and to the tuning fork base 43c which is fixed to the case 41. Then resonance is generated in the tuning fork whose frequency is approximately equal to the knocking frequency. The tuning fork leads 43a and 43b and the strain sensors 42a an 42b are vibrated at the same time, and the electric output can be taken out. |
