PURPOSE: To make a piston position detectable with high accuracy at plural positions in the midway.
CONSTITUTION: A section-elliptocal cylinder tube 2 is provided with an elliptical section piston 11 turnably. In addition, a rotational displacement part 18 is supported on a storage chamber 8 rotatably and unshiftably in the axial direction. An external thread part 15 formed at the peripheral side of a piston rod 9 is screwed in an internal thread part of a nut 19 of this rotational displacement part 18. A magnet ring 21 consisting of a lot of magnetic poles formed at equi-pitches is installed at the peripheral side of the displacement part 18. An MR element 22 is installed in a position being opposed to each magnetic pole, and connected to a detector circuit part 23. In this connection, and extent of circumferential travel of each magnetic pole to the MR element to that of the piston rod 9 is satisfactorily largely set up.
KAWAMURA YUKIO
HAYASHIMOTO SHIGERU
| JPH0669406B2 | 1994-09-07 | |||
| JP63139305B | ||||
| JPH0623561A | 1994-02-01 | |||
| JPS544993B1 | 1979-03-12 |
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