| 摘要 |
PURPOSE:To prevent invasion of humidity from the outside to an electrostrictive element and to eliminate short circuit, by mounting a terminal member and a cover member on the opposite ends of a layer-built sintered body in the layer building direction, and sealing the members together with the electrostrictive element within a tube. CONSTITUTION:In a layer-built sintered body having piezoelectric ceramic sheets and internal electrode conductor sheets laid one over another alternately, the end faces of said internal electrode conductor sheets exposed on two opposed side faces of the body are insulated altenately, such that the end face of an internal electrode conductor sheet on one of said side faces of the body is insulated and the end face of the next internal electrode conductor sheet on the same side face of the body is not. The ends of the internal electrode conductor sheets not insulated are connected to external electrodes provided on said side faces. In an electrorestrictive element 1 thus constructed, a terminal member 11 having a pair of lead terminals 12 is provided on one end face of said layer-built sintered body in the layer building direction such that the lead terminals are connected with the external electrodes 2 through leads 3 and such that the assembly can be hermetically sealed by the terminal member 11. A cover member 13 is secured on the other end face. Further, a tube 14 is provided to cover a part of the side faces of the members 11 and 13 while gaps defined between the tube 14 and the members 11, 13 are filled with a sealing material 15. Thus, the electromagnetic element 1 is held within the tube. |
