Magnetostriction type actuator

A magnetostriction type actuator comprising:

• displacement generating means formed of a magnetic substance having magnetostriction;
• magnetic field generating means comprising first magnetic field generating means for a displacement in said displacement generating means and second magnetic field generating means for applying a magnetic bias;
• detection means for detecting a factor which influences a strain variation in said displacement generating means;
• and
• control means, connected to the detection means, for controlling a magnetic field applied from the magnetic field generating means to said displacement generating means, on the basis of a detection signal supplied from the detection means.

A magnetostriction type actuator comprising:

• displacement generating means formed of a magnetic substance having magnetostriction;
• magnetic field generating means, provided around said displacement generating means, for applying a magnetic field to said displacement generating means;
• detection means for detecting a magnetic characteristic of said displacement generating means, said detection means including a coil wound around said displacement generating means and surrounded by said magnetic field generating means;
• and
• control means, connected to the detection means, for controlling a magnetic field applied from the magnetic field generating means to said displacement generating means, on the basis of a detection signal supplied from the detection means.

A magnetostriction type actuator comprising:

• displacement generating means formed of a magnetic substance having magnetostriction;
• a movable member fixed to said displacement generating means, said movable member being movable in the direction of displacement of said displacement generating means;
• magnetic field generating means comprising at least two components, provided around said displacement generating means, for applying magnetic field to said displacement generating means;
• and
• a magnetic circuit component for constituting, along with said movable member, a main part of a closed magnetic circuit, within which said magnetic circuit component, said displacement generating means and said magnetic field generating means are stored.