| 摘要 |
<p>This aims to provide a multi-layer piezoelectric element, which is made excellent in durability and suppressed in the reduction of a displacement degree, even if the element is largely displaced or driven at a high speed, and an injection device and a fuel injection system using the element. The multi-layer piezoelectric element comprises a stacked body comprising a plurality of ceramic layers and a plurality of internal electrode layers, each of the plurality of internal electrode layers being sandwiched between ceramic layers of the plurality of ceramic layers that are located opposite to each other. The plurality of ceramic layers comprises a plurality of piezoelectric layers, and a low-rigidity ceramic layer which has a rigidity lower than that of the plurality of piezoelectric layers and that of the plurality of internal electrode layers. The low-rigidity ceramic layer comprises a plurality of ceramic portions which are apart from each other via a void , and a covering layer which covers at least a part of an outer surface of the plurality of ceramic portions.</p> |
