Simplified accelerometer sensor for detecting automobile engine misfire vibration (pinking), uses piezoelectric washer surrounded by two electrodes and isolated from seismic annular block

摘要

The sensor includes a piezoelectric washer.(6') surrounded by two annular electrodes (71', 72') and a seismic annular block (9') with a tubular support (17) for them all. a part (19) isolates the washer from the annular block. The support and isolating part are formed from one piece (15) of an isolating material. The support and isolating part (15) includes: (a) a tubular part (17) receiving the washer (19) and annular block (9'), and; an annular part (19) connected to the part (17) and inserted between the washer (6') and block (9') The part (17) extends axially from the washer and has a shoulder (21) to retain the washer. The part (19) has means for positioning connections (25) for the electrodes (7'). The whole assembly is covered by a plastic material. An Independent claim Is also included for a method of fabrication.