| 摘要 |
PROBLEM TO BE SOLVED: To provide a tool inserting end portion of a rotating and/or striking tool, capable of transmitting a high rotation moment without wearing, and finely suppressing impact. SOLUTION: Stamping concave portions 5 are provided in at least three positions of 0°, 120°, 240°from radial direction dimensions R, on a cross section Ic-Ic orthogonal to an axis A of a locking area 3 at least partially extending along the axis A at the tool inserting end portion. The stamping concave portion terminates at axial both side end portions of each stamping concave portion, and at least one casting projecting portion 6 projecting from the radial direction dimensions R is provide between the two stamping concave portions 5 adjacent to each other. The sum of center anglesαexpected by the radial direction dimensions R of the stamping concave portions 5 is made to be at least 150°. When viewed from the cross section Ic-Ic, the sum of center anglesβexpected by the radial direction dimensions R of the casting projecting portion 6 is made to be smaller than 150°, and the sum total of the center expecting angles is made to be at least 15°. COPYRIGHT: (C)2005,JPO&NCIPI |
