| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezo-electric element and a knocking sensor using the element, containing only minor Pb and having a large piezo-electric distortion constant and excellent heat resistance. <P>SOLUTION: This piexo-electric element comprises a base substance made of a piezo-electric porcelain composition containing 0.1 wt% or less of Pb and a pair of electrodes formed on surface of the base substance containing 0.1 wt% or less of Pb. It is especially favorable to use a piezo-electric porcelain composition expressed by a specific composition formula. It is also possible to use a piezo-electric composition containing 2 wt% or less of a specific metal element oxide or a piezo-electric porcelain composition containing 2 wt% or less of a rare earth element oxide. The knocking sensor comprises the base substance made of these piezo-electric compositions, and one of the electrodes is formed on one surface of the base substance and the other on the other surface of the base substance. <P>COPYRIGHT: (C)2004,JPO |
