| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable avoidance of bending deformation and eccentricity of an injection pipe and a decrease in the strength of the injection pipe, which are caused by a reaction force based on injection pressure, while sufficiently increasing drilling efficiency of a drilled wall surface by a jetted liquid. <P>SOLUTION: A plurality of injection nozzles 10 are provided on an outer peripheral surface of a monitor mechanism 9 in such a manner that an injection port faces on the side of one of areas formed by circumferentially dividing the outer peripheral surface into two parts. The plurality of injection nozzles 10 are disposed in the state of being provided in line in an obliquely vertical direction. A rod centralizer 16 is provided to cover an outer periphery of an injection pipe 1 above the injection nozzle 10. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
