| 摘要 |
<p>PURPOSE:To accurately detect a position through a magnetostrictive metallic plate is not preliminarily magnetized, by providing plural fixed electromagnetic coils, which magnetize radially the area of the magnetostrictive metallic plate, near the end part of this metallic plate. CONSTITUTION:A fixed electromagnetic coil 13 is placed at the coordinate origin on a magnetostrictive metallic plate 10, and three similar fixed coils are arranged as shown in the figure. A pulse is generated to magnetize a moving electromagnetic coil 11 when the coil 11 is moved and is placed on an coordinate point on the metallic plate 10, and then, a momentary magnetostrictive wave is generated at this point on the metallic plate 10 and is propagated radially with this point as the center. Each of fixed electromagnetic coils 12-15 detects arrival of this wave, and the time required for propagation is stored in a storage circuit of a processor. The processor operates four stored times to calculate the coordinate value of this point.</p> |
