| 摘要 |
This invention provides an ultrasonic sensor having a structure which can be uniformly packed with a foaming resin in a case and can realize good properties. The ultrasonic sensor (10) comprises a closed end cylindrical case (12). A piezoelectric element (18) is bonded to a bottom (12a) within the case (12). Further, a felt (22) is bonded onto the piezoelectric element (18). A lid member (24) comprising a fixed part (26) and a substrate (28) having a larger hardness than the fixed part (26) is fitted into the case (12) in its opening. Wires (38a, 38b) are connected to terminals (36a, 36b) pressed into the substrate (28), and the terminals (36a, 36b) are connected electrically to the piezoelectric element (18). Through-holes (40) are formed in the fixed part (26). A resin before foaming is poured through the through-hole (40) followed by foaming, whereby a foaming resin (42) is filled into the case (12) while pushing out excess foaming resin (42) to the outside of the case (12) through the through-hole (40). |
