Piezoelectric acoustic device e.g. for buzzer has insulator cap held with adhesive to diaphragm

摘要

The device has a diaphragm (1) comprising a rectangular piezoelectric plate (2) and a metal plate (3) connected to piezoelectric plate. An insulator cap (4) has two holding parts (4c) for holding the diaphragm inside the cap on the cap's inside walls. Two of the sides of the diaphragm are held with adhesive to the holding parts. A gap between the other two sides of the diaphragm and the cap is filled with elastic sealing material. An acoustic chamber is defined between the diaphragm and the upper wall (4a) of the cap. An Independent claim is included for a piezoelectric acoustic device.