| 摘要 |
A groove (9) is formed on the outer periphery of an adapter (1) which is connected to the electric motor (3). A fluid supply line (11) is also formed on the adapter (1) so as to lead fluid to the groove (9). Openings (27) are provided at a proximal end of a shank (22), adjacent to the groove (9). Guide flutes (28) extending from the openings (27) to a tip of the shank (22) are formed at an outer periphery of the shank (22) so as to define passages for leading the fluid introduced from the openings (27) to the tip of the shank (22) to be sprayed upon the cutting debris. Exhaust ports (14) for discharging the debris and exhaust passages (15) for leading the debris through the shank (22) to the exhaust ports (14) are provided at the adapter (1). The guide flutes (28) can be formed with milling machine or the like. In use the drill or tubular saw is pressed against a material (51) while being rotated. Then, the fluid is introduced into the passages (28) betwen the shank (22) and a sleeve (29) and is sprayed upon the cutting debris. A suction is applied through a central portion of the shank (22) to remove the ctting debris. The suction is strong enough to suck granular abrasives into the drilling area from outside the drill. The abrasive effect of the abrasives promotes self sharpening of the cutting teeth. Abrasives are supplied to the drilling area when the cutting teeth (26) come into contact with reinforcing bars embedded in the concrete (51) being sawn. |
