Abstract: An impact absorbing structure includes: a first member composed of a metallic material; and a second member extending in an axial direction of the first member, wherein: a shape of the first member is a cylindrical shape; a length of the second member in the axial direction is a length of 15 to 75% of a length in the axial direction of the first member; when a distance between end portions of the first member and the second member is set as D, a maximum curvature radius of the first member is set as R, and a sheet thickness of the first member is set as t, D<0.40Rt is satisfied; and a joint line, extending along a direction different from a circumferential direction of the first member, of the first member and the second member is present.

Abstract: A suspension arm includes a main body. The main body includes a curved portion curved along a longitudinal direction and has a closed section. The main body includes an inner side wall, an outer side wall, a first side wall, and a second side wall. The inner side wall corresponds to an inner side of a curve of the curved portion. The outer side wall corresponds to an outer side of the curve of the curved portion. A thickness of the inner side wall is larger than a thickness of the outer side wall. In sectional view of the main body perpendicular to the longitudinal direction, each of a length of the first side wall and a length of the second side wall is longer than each of a length of the inner side wall and a length of the outer side wall.

Abstract: Provided is a burring processing method, which is a method for forming a buffing processed portion including a raised portion and a curved portion in a metal component having a pilot hole formed therein, the method being characterized by including: a preforming step of enlarging a diameter of the pilot hole, moving an edge portion of the pilot hole relative to the metal component in a first direction of a thickness direction of the metal component in a first range around the pilot hole of the metal component, and forming the whole first range into a preformed portion raised from the metal component in the first direction; and a main forming step of deforming the preformed portion in a second direction opposite to the first direction, forming a second range on an outer diameter side of the preformed portion to have the same height as the first range in the first direction, and forming part of a third range on an inner diameter side of the preformed portion from the second range to be part of the curved portion

Abstract: A die includes a first die and a second die, and at least one of the first die or the second die includes: a bottom portion having a plate shape; a top portion having a plate shape and is provided apart from the bottom portion; and a stiffening member having one end directly connected to the bottom portion and another end connected to the top portion, the stiffening member extending in an inclined manner from a connection portion with the bottom portion toward a side at which a center of the top portion is located as the stiffening member extends from the bottom portion side toward the top portion side.

Abstract: An automobile structural member being a hollow automobile structural member having: a top wall part; a bottom wall part facing the top wall part; and a first heightwise wall part and a second heightwise wall part being a pair of heightwise wall parts that connect to the top wall part and the bottom wall part, the automobile structural member including: a first reinforcing part having one end portion joined to the top wall part and the other end portion joined to the bottom wall part; and a second reinforcing part having one end portion joined to either the first heightwise wall part or the second heightwise wall part, and the other end portion joined to the first reinforcing part, in which a plurality of the second reinforcing parts are provided along a height direction of the heightwise wall part.

Abstract: An automobile structural member being a hollow automobile structural member having: a top wall part; a bottom wall part facing the top wall part; and a pair of heightwise wall parts that connect to the top wall part and the bottom wall part, the automobile structural member including a first corrugated reinforcing member being inside the automobile structural member, wherein: a bottom portion and a top portion of the first corrugated reinforcing member extend in a direction from the top wall part toward the bottom wall part; and the bottom portion of the first corrugated reinforcing member is joined to an inner surface of the heightwise wall part of either of a pair of the heightwise wall parts.

Abstract: An automobile structural member being a hollow automobile structural member having: a top wall part; a bottom wall part facing the top wall part; and a pair of heightwise wall parts that connect to the top wall part and the bottom wall part, the automobile structural member including a first corrugated reinforcing member being inside the automobile structural member, wherein: a bottom portion and a top portion of the first corrugated reinforcing member extend in a direction from the top wall part toward the bottom wall part; and the bottom portion of the first corrugated reinforcing member is joined to an inner surface of the heightwise wall part of either of a pair of the heightwise wall parts.

Abstract: An automobile structural member being a hollow automobile structural member having: a top wall part; a bottom wall part facing the top wall part; and a first heightwise wall part and a second heightwise wall part being a pair of heightwise wall parts that connect to the top wall part and the bottom wall part, the automobile structural member including: a first reinforcing part having one end portion joined to the top wall part and the other end portion joined to the bottom wall part; and a second reinforcing part having one end portion joined to either the first heightwise wall part or the second heightwise wall part, and the other end portion joined to the first reinforcing part, in which a plurality of the second reinforcing parts are provided along a height direction of the heightwise wall part.