| 摘要 |
PROBLEM TO BE SOLVED: To ensure a large bore diameter by shortening a standoff distance even at the time of one nozzle installed to a rod, to prevent the generation of a cutting-residue section, to select cutting and drilling in different patterns properly, to carry out cutting and drilling corresponding to the state of a cut cross section such as the presence of a steel material, etc., and to conduct operation efficiently. SOLUTION: A casing rod 2 supporting an abrasive jet nozzle 1 is rotated and/or forward moved and retreated simultaneously by a forward-retreat mechanism and a rolling mechanism while arbitrarily changing the angle of the abrasive jet nozzle 1 as a member injecting abrasive-mixed high-pressure jet water by an injection-angle changing mechanism, and cutting or drilling is performed. The angle of the abrasive jet nozzle 1 and the rotation and forward movement and retreat of the casing rod 2 at the time of cutting and drilling are selected properly in response to the state of a drilled cross section such as the presence of a steel material and the shape, etc., of the steel material, an object such as a pile is bored, and cut and drilled places are continued and the object such as the pile is cut.
|
