NOZZLE HEAD FOR HIGH-PRESSURE WATER DRILLING

摘要

PROBLEM TO BE SOLVED: To solve a problem where a conventional method for drilling a horizontal hole in an existing reinforced concrete structure by ejecting high-pressure water has extremely low workability, in particular, a difficulty in smoothly processing the horizontal hole in an axial direction.SOLUTION: A nozzle head for high-pressure water drilling has three high-pressure water ejection ports. Three high-pressure water passages connecting the high-pressure water ejection ports and high-pressure water supply pipe are inclined with respect to a shaft center of the high-pressure water supply pipe. One of the high-pressure water passages having the high-pressure water ejection port with a center thereof arranged at a position most remote from the shaft center when viewed from a front side has a larger inclination angle than the other high-pressure water passages.