| 摘要 |
PURPOSE:To reduce in size a power source by operating in advance a clamping force at a plunger, and applying a driving voltage from both normal and reverse directions to piezoelectric elements. CONSTITUTION:An automatic valve B is composed of a piezoelectric actuator A. In the actuator A, an axially telescoping plunger P is mounted in a cylindrical case having front and rear walls (a), (b), and four clamping and stroke piezoelectric elements (e)-(h) are disposed on the outer periphery. The stroke elements (g), (h) are secured to the end of a stationary bridge (d), and the clamp elements (e), (f) are secured to the outer peripheries of the ends of elastic bridges (i), (j). The ends of the bridges (i), (j) are energized at brake shoes (k), (l) inwardly, and approx. 1/2 of the clamping force is operated in advance at the plunger P. Thus, a pulselike driving voltage is fed from a driver to the elements (e)-(h) to move the plunger P synchronously. |
