| 摘要 |
PURPOSE:To make it possible to effectively prevent shortcircuit even if a crack is generated in a piezoelectric element, by interposing a ring shaped soft metal plate between an electrode plate and a pressure receiving plate. CONSTITUTION:In the title washer shaped pressure sensor, ring shaped pressure receiving plate 4a, 4b made of stainless steel are arranged concentrically in opposed relation to each other and ring shaped piezoelectric elements 7a, 7b made of ceramic are arranged between said pressure receiving plates 4a, 4b and an electrode plate 8 is further interposed between the above-mentioned piezoelectric elements 7a, 7b. Said electrode plate 8 is formed as a flat ring shape and a signal take-out terminal 10 is provided to a part of the outer peripheral edge thereof so as to be protruded to the outside. Because metal plates 16a, 16b and 16c, 16d comprising a relatively soft metal such as steel are laminated to both surfaces of the piezoelectric elements 7a, 7b in a closely adhered state, even if a crack is generated in the piezoelectric elements, the shortcircuit accompanied by said crack can be effectively prevented. |
