| 摘要 |
PROBLEM TO BE SOLVED: To increase an engaging strength of a tool and a connection member without occurrence of breakage of a tool body and a punch.SOLUTION: In a state that a cylindrical fitting part 21 of a connection member 2 made of a metallic material having a hardness lower than that of a tool body 1 made of a hard metal, cermet and ceramic is inserted in a mounting hole 16 having a recess 17 on an inner peripheral surface of the tool body 1 and an outer peripheral surface of the fitting part 21 is engaged with the recess 17 while being stuck onto an inner peripheral surface of the mounting hole 16, the tool body 1 and the connection member 2 are joined with each other. The recess 17 has a first wall surface 17a which approaches an outer peripheral side as approaching an insertion direction F side of the fitting part 21, and a second wall surface 17b which approaches an inner peripheral side as approaching the insertion direction F side opposite to the first wall surface 17a, a first tilt angle α, which is formed with respect to a flat surface S perpendicular to a center line of the mounting hole 16 at a position at which the first wall surface 17a intersects the inner peripheral surface of the mounting hole 16, is so made as to be smaller than a second tilt angle β which is formed with respect to the flat surface S at a position at which the second wall surface 17b intersects the inner peripheral surface of the mounting hole 16.SELECTED DRAWING: Figure 6 |
