Abstract: Provided is a frame member formed by hot-stamping a steel sheet. The frame member has a closed cross section portion in which a cross section perpendicular to a longitudinal direction is a closed cross section, and the closed cross section portion has at least two flat parts having a radius of curvature larger than a maximum external dimension of the cross section, and a recessed bead part formed between the two flat parts. The recessed bead part has a pair of wall portions which have a radius of curvature of 50 mm or greater, and protrude toward an inside of the closed cross section portion from end portions of the two flat parts facing each other via a pair of bent portions bent toward an inside of the closed cross section. A Vickers hardness of a thickness middle portion in the wall portion is 520 Hv or greater, a width of the wall portion is 0.5 times or greater and 2.

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: Provided is a frame member formed by hot-stamping a steel sheet. The frame member has a closed cross section portion in which a cross section perpendicular to a longitudinal direction is a closed cross section, and the closed cross section portion has at least two flat parts having a radius of curvature larger than a maximum external dimension of the cross section, and a recessed bead part formed between the two flat parts. The recessed bead part has a pair of wall portions which have a radius of curvature of 50 mm or greater, and protrude toward an inside of the closed cross section portion from end portions of the two flat parts facing each other via a pair of bent portions bent toward an inside of the closed cross section. A Vickers hardness of a thickness middle portion in the wall portion is 520 Hv or greater, a width of the wall portion is 0.5 times or greater and 2.

Abstract: The present invention has as its technical problem to provide a punching method able to stably secure a stretch-flangeability equal to or greater than the case of using a punch having a flat blade at its bottom surface. The punching method of the present invention is a method of punching a metal sheet using a punching and shearing device provided with a punch having an upper blade having a horizontal part with respect to the cutting line in part and having parts other than the horizontal part comprised of inclined parts and a die having a lower blade wherein the upper blade used for the punching process has a shape where the inclined parts first contact the metal sheet at the time of a punching process.

Abstract: The present disclosure provides a structural member comprising an edge portion T1 and an edge portion T2 opposing the edge portion T1 in plan view in height direction (Z axis direction); when an axis direction connecting the edge portion T1 and the edge portion T2 is regarded as an X axis direction, the structural member includes, along the X axis direction, a region A including the edge portion T1, and a region B located on the edge portion T2 side than the region A and including the edge portion T2; in a cross-section perpendicular to the X axis direction, the region A includes a closed cross-section portion A whose outer rim shape is one closed cross-section A; and the region B includes a closed cross-section portion B satisfying a predetermined (i) or (ii).

Abstract: A structural part includes a part body and a cylindrical bush. The part body includes a through-hole and a cylindrical flange part provided in the periphery of the through-hole. The bush is inserted into the through-hole and the flange part. When seen in a cross section including a central axis of the bush, the flange part has a height difference between a first part that contacts the bush on one side in a direction perpendicular to the central axis and a second part that contacts the bush on the other side.

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: A structural part includes a part body and a cylindrical bush. The part body includes a through-hole and a cylindrical flange part provided in the periphery of the through-hole. The bush is inserted into the through-hole and the flange part. When seen in a cross section including a central axis of the bush, the flange part has a height difference between a first part that contacts the bush on one side in a direction perpendicular to the central axis and a second part that contacts the bush on the other side.

Abstract: As a burring processed member able to suppress the formation of fatigue cracks in a burring part, one having a structure satisfying the following relations (1) to (3) is disclosed: 3?Ra?100 . . . (1), 3.0<h . . . (2), 24+r?[TS/(40+0.28×Ra)]<h . . . (3), where, “Ra” is an arithmetic mean roughness (?m) of the burring end face, “h” is a height (mm) from the first surface to the burring end face, “r” is a radius of curvature (mm) of the curved wall part, and “TS” is the tensile strength (MPa) of the sheet-shaped part.

Abstract: What is provided is an automobile body in which batteries, tires, and liquids containing water and oil are removed from a public road vehicle with superior collision safety, the public road vehicle comprising at least a steel material containing a steel sheet with a tensile strength of 1180 MPa or higher, a non-ferrous metal material, and a resin material, wherein the ratio of a mass mh (kg) of the steel sheet having a tensile strength of 1180 MPa or higher to a mass m (kg) of the automobile body is 9% or higher, and a mass m (kg) of the automobile body and a projected area s (m2) of the automobile body from an upper side satisfy a formula (1) and a formula (2) 6 < s < 11 ( 1 ) m < ( 2 ? 7 ? 2 . 3 ? 7 × s - 8 ? 3 ? 5 ) × 0 ? .98 .

Abstract: The present disclosure provides a structural member comprising an edge portion T1 and an edge portion T2 opposing the edge portion T1 in plan view in height direction (Z axis direction); when an axis direction connecting the edge portion T1 and the edge portion T2 is regarded as an X axis direction, the structural member includes, along the X axis direction, a region A including the edge portion T1, and a region B located on the edge portion T2 side than the region A and including the edge portion T2; in a cross-section perpendicular to the X axis direction, the region A includes a closed cross-section portion A whose outer rim shape is one closed cross-section A; and the region B includes a closed cross-section portion B satisfying a predetermined (i) or (ii).

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: As a burring processed member able to suppress the formation of fatigue cracks in a burring part, one having a structure satisfying the following relations (1) to (3) is disclosed: 3?Ra?100 . . . (1), 3.0<h . . . (2), 24+r?[TS/(40+0.28×Ra)]<h . . . (3), where, “Ra” is an arithmetic mean roughness (?m) of the burring end face, “h” is a height (mm) from the first surface to the burring end face, “r” is a radius of curvature (mm) of the curved wall part, and “TS” is the tensile strength (MPa) of the sheet-shaped part.

Abstract: An electronic wind instrument includes a breath sensor, an operating element, a speaker, and an acoustic tube. The operating element receives an instruction related to a pitch. The speaker outputs a sound based on musical performance information obtained from at least one of the breath sensor and the operating element. The speaker has an inner space therein. The acoustic tube that has an inner space therein. The inner space of the acoustic tube is continuous with the inner space of the speaker. The acoustic tube extends in a direction away from the speaker.

Abstract: A strength flanging method which improves the method of stretch flanging by press forming so as to disperse strain generated during a forming operation in a blank and in turn prevent the formation of cracks at the center of an arc part, which strength flanging method performs stretch flanging using a stretch flanging tool provided with a top surface part having a protruding part in a top view, straight wall parts, a main slanted wall part between the top surface part and the straight wall parts positioned forming an angle with the top surface part of more than 0° and less than 90° and with the straight wall parts of 10° or more and less than 90° and having two intersecting ridgelines at the straight wall part sides, a first sub slanted wall part sharing one ridgeline among the two ridgelines with the main slanted wall part and positioned forming angles with the top surface part and a straight wall part of more than 0° and less than 90°, and a second sub slanted wall part sharing the other ridgeline among the

Abstract: This manufacturing method of a structural member includes an intermediate step and a bending step. A height difference is provided on a bottom wall of a groove part between an intermediate position and both end positions sandwiching the intermediate position therebetween in a longitudinal sectional view in an extending direction of the groove part by the pressing in the intermediate step, and thereby at least one of a first curved part which has a concave curved shape in a plan view and a convex curved shape in the longitudinal sectional view and a second curved part which has a convex curved shape in the plan view and a concave curved shape in the longitudinal sectional view is formed on the bottom wall.

Abstract: This manufacturing method of a structural member includes an intermediate step and a bending step. A height difference is provided on a bottom wall of a groove part between an intermediate position and both end positions sandwiching the intermediate position therebetween in a longitudinal sectional view in an extending direction of the groove part by the pressing in the intermediate step, and thereby at least one of a first curved part which has a concave curved shape in a plan view and a convex curved shape in the longitudinal sectional view and a second curved part which has a convex curved shape in the plan view and a concave curved shape in the longitudinal sectional view is formed on the bottom wall.

Abstract: The present invention has as its technical problem to provide a punching method able to stably secure a stretch-flangeability equal to or greater than the case of using a punch having a flat blade at its bottom surface. The punching method of the present invention is a method of punching a metal sheet using a punching and shearing device provided with a punch having an upper blade having a horizontal part with respect to the cutting line in part and having parts other than the horizontal part comprised of inclined parts and a die having a lower blade wherein the upper blade used for the punching process has a shape where the inclined parts first contact the metal sheet at the time of a punching process.

Abstract: An electronic wind instrument includes a breath sensor, an operating element, a speaker, and an acoustic tube. The operating element receives an instruction related to a pitch. The speaker outputs a sound based on musical performance information obtained from at least one of the breath sensor and the operating element. The speaker has an inner space therein. The acoustic tube that has an inner space therein. The inner space of the acoustic tube is continuous with the inner space of the speaker. The acoustic tube extends in a direction away from the speaker.