| 摘要 |
PURPOSE:To produce a small shaped switching valve having excellent stability and high performance inspite of the use of a highly answerable piezoelectric element by transmitting the displacement of a piezoelectric actuator to a plunger through a stroke amplifying mechanism. CONSTITUTION:When applied with the some quantity of voltage, a piezoelectric element 23 elongates upward. Consequently, a plunger 31 moves downward, but since a spring 41 is pressing a rod 30, the rod 30 does not move up to a certain voltage V1, and the movement of plunger 31 transforms into the move ment of a retainer as it is. This movement is kept until a ball 29 comes into contact with the valve seat 27b of an inlet port 27a, and further when raised up to the voltage V2, this voltage brings the shoulder 31b of the plunger 31 into contact with the shoulder 30a of the rod 30. Eventually when the applied voltage V is in the condition of V1<V<V2, a drain port 35a and the inlet port 27a are simultaneously closed. In the case of V<V1, the inlet port 27a communicates with an output port 35b, and in the case of V>V2, the drain port 35a communicates with the output port 35b. |
