Vibration sensor for an automotive vehicle

摘要

A vibration sensor for an automotive vehicle having a multi-peak vibration characteristic of wider responsiveness and of a higher S/N ratio. The vibration sensor comprises a plurality of piezoelectric vibrators so arranged that the piezoelectric voltage signals from the vibrators are synthesized in reverse polarity between two elements having two adjacent resonant frequencies, when the element are deformed in the same direction. Therefore, the voltages are synthesized in the same polarity, when engine knocking frequency lies between two adjacent sensor resonant frequencies, because a vibrator is 180 degrees out of phase with another adjacent vibrator.