| 摘要 |
PROBLEM TO BE SOLVED: To provide a low cost actuator capable of attaining a simple structure of which control position accuracy is not affected by temperature. SOLUTION: This actuator includes a coil for generating a magnetic field, a magnetostrictive member for generating magnetostriction with the generated magnetic field, and a driving rod for taking out variances in the length of the magnetostrictive member by the magnetostriction. One end of the magnetostrictive member is supported by a hole side of an actuator casing into which the driving rod pierces, a flange lower surface of the driving rod is brought into contact with the other end of the magnetostrictive member, an upper surface of the flange is energized by an elastic member in a hole direction in which the driving rod of the actuator casing pierces, and a ratio of a length ranging from the driving rod flange lower surface to an end surface of the driving rod in which the hole pierces to a length of the magnetostrictive member is made equal to the ratio of the linear expansion coefficient of the magnetostrictive member to a linear expansion coefficient of the driving rod material. |
