| 摘要 |
<p>PURPOSE:To reduce the number of magnetic sensors and to enhance the detecting accuracy by fixing a magnetic field detector comprised of two magnetic sensors intersecting with predetermined angles to a rotary shaft of a motor at a predetermined position of an underground excavator. CONSTITUTION:A magnetic field detector 21 is constituted of two magnetic sensors 211, 212 which intersect, for example, at 90 deg.. The magnetic field detector 21 is fixed to a rotary shaft 11 of a pulse motor 10. The motor 10 is built in a front rod of a boring machine of small diameter of a consolidation type provided at the veference position of the underground excavator. By rotating an stopping the motor 10, the position of the magnetic field detector 21 is freely set in the horizontal and vertical directions. In this manner, even if the boring machine is rotated, the relation of the magnetic field detector 21 in the horizontal and vertical directions can be maintained as desired by rotating and adjusting the motor 10. Since there are two sensors, the detecting accuracy is improved.</p> |
