Patent ID: 11264770

Abstract:
A crimping die including a first die piece having a recess portion and a second die piece having a protrusion portion is provided. An inner wall surface of the recess portion has a bottom wall surface and recess-side lateral end surfaces. An outer surface of the protrusion portion has a top end surface and protrusion-side lateral end surfaces. The bottom wall surface has a recess-side projection portion, a recess-side concave portion, and a recess-side curvature changing portion. The top end surface has a protrusion-side projection portion, a protrusion-side concave portion, and a protrusion-side curvature changing portion. A sign of curvature of the bottom wall surface changes at a boundary portion in the recess-side curvature changing portion with respect to the recess-side concave portion. A sign of curvature of the top end surface changes at a boundary portion in the protrusion-side curvature changing portion with respect to the protrusion-side concave portion.