Provided is a manufacturing method for a cylindrical portion in a cylindrical shape protruding in a plate thickness direction of a plate-like portion made of metal, the cylindrical portion being formed integrally with the plate-like portion. The manufacturing method uses a manufacturing device including: a first metal mold provided with an inner circumferential surface that comes in contact with an outer circumferential surface of the cylindrical portion; a second metal mold coming in contact with a protruding tip of the cylindrical portion; and a third metal mold coming into press contact with a workpiece toward a side of the second metal mold. The third metal mold is displaced toward the side of the second metal mold and a portion of the workpiece undergoes plastic flow toward the inner circumferential surface, whereby the portion that underwent the plastic flow comes into press contact with the inner circumferential surface.

Provided is a manufacturing method for a cylindrical portion in a cylindrical shape protruding in a plate thickness direction of a plate-like portion made of metal, the cylindrical portion being formed integrally with the plate-like portion. The manufacturing method uses a manufacturing device including: a first metal mold provided with an inner circumferential surface that comes in contact with an outer circumferential surface of the cylindrical portion; a second metal mold coming in contact with a protruding tip of the cylindrical portion; and a third metal mold coming into press contact with a workpiece toward a side of the second metal mold. The third metal mold is displaced toward the side of the second metal mold and a portion of the workpiece undergoes plastic flow toward the inner circumferential surface, whereby the portion that underwent the plastic flow comes into press contact with the inner circumferential surface.

A drawn body for a vehicle structural member has a tensile strength of 980 MPa or more, radii of curvature of two first convex ridge portions, a second convex ridge portion, and a concave ridge portion are each 30 mm or less, a corner radius of a corner wall is 30 mm or less, and a forming depth which is a separation distance between a top sheet portion and an outwardly-extending flange is 40 mm or more.

A drawn body for a vehicle structural member has a tensile strength of 980 MPa or more, radii of curvature of two first convex ridge portions, a second convex ridge portion, and a concave ridge portion are each 30 mm or less, a corner radius of a corner wall is 30 mm or less, and a forming depth which is a separation distance between a top sheet portion and an outwardly-extending flange is 40 mm or more.

A method for manufacturing a press-formed product includes a first step and a second step. In the first step, a concavity is press formed in a blank by use of a punch and a first die. The punch has a shape corresponding to the shape of the entire press-formed product. The first die has a shape corresponding to at least the shape of the concavity. In the second step, a vertical wall and an edge portion are press formed in the blank by use of the punch and a second die. The second die is located adjacent to the first die. The second die has a shape corresponding to at least the shape of the vertical wall and the edge portion. The first step is completed after the second step is completed. The method allows production of a press-formed product which is excellent in fatigue resistance.

A method for manufacturing a press-formed product includes a first step and a second step. In the first step, a concavity is press formed in a blank by use of a punch and a first die. The punch has a shape corresponding to the shape of the entire press-formed product. The first die has a shape corresponding to at least the shape of the concavity. In the second step, a vertical wall and an edge portion are press formed in the blank by use of the punch and a second die. The second die is located adjacent to the first die. The second die has a shape corresponding to at least the shape of the vertical wall and the edge portion. The first step is completed after the second step is completed. The method allows production of a press-formed product which is excellent in fatigue resistance.

A pneumatic chamber 20 is configured to include a first pneumatic chamber 21 pressurizing a first piston 11 and a second pneumatic chamber 22 pressurizing a second piston 12. The first pneumatic chamber 21 and the second pneumatic chamber 22 communicate with each other through a communication hole 87 formed via the inside of a retaining bolt 17. The second pneumatic chamber 22 is formed in a hydraulic pressure generating unit 55 moving in a thrust direction in a cylinder 2 and is separable from the first pneumatic chamber 21. In addition, the communication hole 87 is also separated into a communication hole 87a and a communication hole 87b with the corresponding separation, a rod portion 50 of the first piston 11 is also separated into a rod portion 50a and a rod portion 50b, and the communication hole 87b and the rod portion 50b are formed to be movable along with the hydraulic pressure generating unit 55 in the thrust direction.

A manufacturing method of a press-formed article includes: forming a specified shape in a plate-like member made of metal; forming a convex portion in a portion that does not undergo deformation by the forming of the specified shape in the plate-like member; and flattening the convex portion.

A method for manufacturing a press formed product is disclosed. The method for manufacturing a press formed product includes: when a metal sheet is press formed to manufacture a product having a product shape of a hat-shaped cross-section, in which a top plate part and a flange part are continuous in a width direction through a side wall part and the top plate part and the flange part curve convexly or concavely toward the top plate part along a longitudinal direction, a first step of manufacturing an intermediate component by press forming into a component shape having a hat-shaped cross-section, in which a curve of each of the top plate part and the flange part along the longitudinal direction has a second curvature radius smaller than a curvature radius in the product shape; and a second step of press forming the intermediate component into the product shape.

This method for manufacturing a panel-like formed article has preparing a blank material made of a metal sheet having a tensile strength of 390 MPa or more and 980 MPa or less; and press-forming the blank material in a cold manner using a pressing apparatus to form the blank material into the panel-like formed article, in the press-forming, a blank holder, a first punch, and a second punch are relatively moved with respect to a die, thereby pressing the first punch and the second punch to the blank material, and pressing of the second punch to the blank material is completed before pressing of the first punch to the blank material.