| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of detecting an amount of displacement of a worm shaft, for accurately detecting the amount of displacement of the worm shaft displaced in a shaft direction according to input torque to an electrically operated valve, with a simple technique. <P>SOLUTION: A magnet 72 attached to the center position of an end surface of a rotary shaft 71 rotating following displacement in the shaft direction of the worm shaft 21 and a magnetic field sensor 73 disposed in a position separated in a radial direction from the center position of the end surface of the rotated shaft 71, are used. When the rotary shaft 71 is rotated following displacement in the shaft direction of the worm shaft 21, the rotational angle of the rotary shaft 71 is acquired according to the change of a magnitude of a sensing signal of the magnetic field sensor accompanying the rotation of the rotary shaft 71, and displacement of the worm shaft 21 corresponding to the rotational angle is detected. <P>COPYRIGHT: (C)2012,JPO&INPIT |
