GUIDE PART DISPOSITION STRUCTURE AND GUIDE PART DISPOSITION METHOD FOR TIP TOOL FOR CUTTING WORK

摘要

The purpose of the present invention is to dispose a third guide part in an appropriate position in which an operation effect is stably obtained and the degree of freedom is higher in a guide part disposition structure and a guide part disposition method which are designed to dispose the third guide part in a predetermined position of a tip tool for cutting work and stably maintain the posture during cutting of the tip tool and the straight advance movement operation of the tip to thereby achieve a favorable surface condition of a worked hole inner circumference. A disposition structure for a guide part which, in a tip tool for performing cutting work while being supplied with cutting oil, receives cutting force of a blade part while being in contact with a hole inner surface of a material to be cut at the outer periphery of the tip tool to form a clearance for passing the cutting oil therethrough, wherein the guide part is configured by disposing three guide parts provided at the outer periphery of the tip tool, the three guide parts being: a first guide part the position of a section of which remotest from a tool rotation center of the guide part in a tool diameter direction is within an angle range of 80°-100° on the retard side in the rotation direction of the blade part with the cutting edge position of the blade part as 0°; a second guide part the position of a section of which remotest from the tool rotation center is within an angle range of 170°-190°; and a third guide part the position of a section of which remotest from the tool rotation center is within at least one angle range among angle ranges of 1°-34°, 146°-179°, and 326°-359°.