Koda and Androlia
Engine vibration sensor
 An improvement in an engine vibration sensor of the type including a vibrator set to resonate at a specific frequency of vibration of the engine to which it is attached, for example the engine knocking vibration frequency, wherein the vibration of the vibrator is converted to an electric signal representing the specific engine vibration. The improvement consists of forming the vibrator from a magnetic material and providing a magnetic field generator for applying a magnetic field of controlled intensity to the vibrator, whereby the resonant frequency of the vibrator can be adjusted by varying the intensity of the magnetic field. 
Kabushiki Kaisha Toyota Chuo Kenkyusho
G G G
G01H G01L G01P
inventional inventional inventional
Haruyoshi Masaharu
Kondo Takeuchi