| 摘要 |
PURPOSE:To protect an electrostriction effect element against breakdown due to positional shift upon expansion/contraction of a piezoelectric actuator by arranging a positioning board being fit to the end of the electrostriction element so that it is fit in a recess of a metallic member. CONSTITUTION:Positioning boards made of glass epoxy aluminum, for example, and performed into discs having rectangular or circular central holes having substantially same diameter as the outer diameter of the electrostriction effect element 1 are fit to the opposite ends of the electrostriction effect element 1 formed by laminating a plurality of electrostriction members and inner electrodes alternately. The positioning board is then fit, at the opposite ends thereof, into circular recesses made in a stainless steel member 3 having U-shaped cross-section and a circular stainless steel member 6 having U-shaped cross-section fixed, respectively, with lead terminals 2a, 2b. Under that state, an expanding/contracting stainless steel case 5, e.g. a bellows, is seal jointed to the metallic members 3, 6 through welding. |
