| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a stroke amount detecting device with enhanced robustness a magnetic circuit of which is reduced in size with respect to a detection range of a stroke amount. <P>SOLUTION: A first magnet 21 and a second magnet 22 have the same magnetic properties, and shapes and magnetization directions thereof are arranged so as to be symmetrical with respect to a reference point O. A first yoke 31 and a second yoke 32 have the same magnetic properties, and shapes thereof are arranged so as to be symmetrical with respect to the reference point O. The first yoke 31 and the second yoke 32 are connected to the first magnet 21 and the second magnet 22, respectively, and transmit magnetic fluxes generated by the first magnet 21 and the second magnet 22. The second yoke 32 is opposite to the first magnet 21 and the first yoke 31 is opposite to the second magnet 22. A Hall element 5 relatively moves on a straight axis x that passes through the reference point O and detects the stroke amount of an object to be detected by a magnetic flux change detected by a magnetic sensing surface 5a. Thus, a detection range of the stroke amount can be efficiently secured by two magnets. Furthermore, robustness with respect to displacement of the Hall element 5 is enhanced. <P>COPYRIGHT: (C)2013,JPO&INPIT |
