1. Field of the Invention
The present invention relates to a cutting insert and an indexable endmill. More specifically, the present invention relates to a cutting insert that can be replaceably attached to a multifunctional endmill capable of drilling and an indexable endmill to which the cutting insert is attached.
2. Description of the Related Art
A number of prior-art multifunctional endmills capable of drilling have been designed. The multifunctional endmill generally includes two cutting inserts attached at a tip end of a cylindrical tool body, and is an endmill capable of performing a cutting work in both of an XY direction (lateral direction) and a Z direction (depth direction) with respect to a work material. The cutting insert attached to such a multifunctional endmill includes a peripheral cutting edge for performing cutting in the lateral direction and a face cutting edge (bottom cutting edge) for performing cutting in the depth direction.
As a cutting insert attached to the multifunctional endmill, for example, the invention disclosed in Japanese Patent Laid-Open No. H10-291115(1998) is known. The multifunctional endmill described in the Japanese Patent Laid-Open No. H10-291115(1998) is of a two-cutting-edge type, which uses two cutting inserts (first cutting insert and second cutting insert). The first cutting insert and the second cutting insert are different from each other, and each of them includes the face cutting edge and the peripheral cutting edge. The cutting work is performed by the multifunctional endmill to which the two types of such cutting inserts are attached.
In addition, as a cutting insert attached to the multifunctional endmill, the invention disclosed in Japanese Patent Laid-Open No. H11-254207(1999) is known. The multifunctional endmill described in the Japanese Patent Laid-Open No. H11-254207(1999) is of a two-cutting-edge type, which uses two cutting inserts (first cutting insert and second cutting insert). The first cutting insert and the second cutting insert are of the same type, and two of the face cutting edge and the peripheral cutting edge are paired, and two pairs of them are provided on a top surface of the cutting insert. In other words, two corners on a diagonal line can be used on the top surface of the cutting insert. On two cutting insert seat surfaces of the endmill, the cutting inserts of the same type are disposed so that different corners are used as the cutting edges involved in cutting.
As described above, according to the invention of the Japanese Patent Laid-Open No. H11-254207(1999), two cutting inserts of the same type to be attached to the endmill of a two-cutting-edge type can be used so that, when the cutting edge is abraded or damaged, the two cutting inserts can be exchanged to use another pair of cutting edges. As described above, since the cutting insert of the same type can be used in turn, manufacturing costs of the cutting inserts can be reduced, and further tool management can be facilitated.