MACHINE TYPE CUTTING DEVICE FOR UNDERWATER ENVIRONMENT AND MACHINE TYPE CUTTING METHOD FOR UNDERWATER ENVIRONMENT

摘要

PROBLEM TO BE SOLVED: To provide a small sized and lightweight machine type cutting device for an underwater environment usable in an underwater environment such as the maintenance work of a nuclear power plant, or in a narrow portion in the underwater environment by further reducing resistance received from the water of a machining blade.SOLUTION: The surface shape of a rotary disk of a machining blade is designed so as to further reduce resistance received from the water of the machining blade, or a mechanism is provided in which the water resistance is reduced. For example, a surface of the rotary disk is subjected to dimpling, or a cover subjected to dimpling is provided at the surface of the rotary disk. Alternately, a surfactant is applied to the dimpled rotary disk surface or the dimpled cover surface, or a part of the machining blade is surrounded with a casing, and gas is supplied into the casing to partially form a gaseous environment. Furthermore, a part of the machining blade is surrounded with the casing, and a water flow or a water flow containing fine air bubbles is applied in the rotation direction of the rotary disk to assist rotation.