1. Field of the Invention
The present invention relates to a cutting edge-replaceable cutting tool adapted to removably mount cutting inserts on a tool body, and in particular, to a cutting edge-removable cutting tool that can be used for high-feed machining and a cutting insert for use therein.
2. Description of the Related Art
As a tool for use in cutting work of a mold or the like, a cutting edge-replaceable endmill is conventionally used in which a cutting insert is mechanically attached to a head of a generally cylindrical tool body adapted to be rotated around an axis thereof to form a cutting edge portion.
In such a cutting edge-replaceable cutting tool, the strength of the tool head required to fixedly support the insert is a major matter. Japanese Patent Laid-Open No. 2005-118965 states that the strength of the head is maintained by setting the ratio between a cross-sectional area defined by the width and thickness of the insert and a central mounting hole and a cross-sectional area defined by the height and thickness of the insert and the central mounting hole to fitting value within a predetermined range, and also setting the ratio between a thickness of a back metal in the tool head and the thickness of the insert to a predetermined value or greater.
However, a construction described in Japanese Patent Laid-Open No. 2005-118965 and adapted to increase the strength of the tool head is restricted in that there must be relations between components such as the ratio between the thickness of the back metal and the thickness of the insert, in a predetermined relation and this reduces the degree of freedom in design of the cutting tool and the insert.