VIBRATION DETECTING SENSOR

PROBLEM TO BE SOLVED: To remove influence of temperature and noise to enable highly accurate vibration detection by fixing a piezoelectric body having a cantilever structure comprising piezoelectric elements for detecting vibration and compensating temperature, which are laminated, on an upper face of an insulation plate provided on a bottom inside a vibrator. SOLUTION: When vibration is transmitted to a vibrator 11, a free end of a piezoelectric body 13 of a cantilever structure is flexed upward and downward, a piezoelectric element 131 for detecting vibration and a piezoelectric element 132 for compensating temperature stretch relatively to each other, electric charges according to their deforming amounts occur, and they are converted into electric signals respectively via electrode layers 131a, 132a and a metallic plate material (joint electrode) 14 and inputted to an electric charge amplifier. Output voltage from the electric charge amplifier is converted into a digital rectangular wave signal via a comparator for detecting a vibration amount. Thus, a malfunctioning output signal due to a change in ambient temperature is removed by the piezoelectric element 132 for compensating temperature, while a through hole 18a with a lead 15 inserted through is filled with a glass material 18c for preventing noise from being acquired.