| 摘要 |
PURPOSE:To enable a driving direction at the forced propulsion of a pilot pipe to be detected simply and accurately. CONSTITUTION:Each of the specified numbers of pilot pipes 4 is connected to a pilot head 3 performing the compression and removal or excavation of earth and sand, and two illuminants 23, 27 are set up in an inner part of one of these pilot pipes 4 separately in two spots in the axial direction as varying their setup modes. At the forced propulsion of the pilot pipes 4, each position of both these illuminants 23, 27 is recognized by a camera means positioned in a starting shaft, and the driving direction is controlled as detecting the extent of dislocation between both these illuminants 23, 27 and a pipe buried planning line. |
