Patent ID: 8584496

Claim:
A press-forming device comprising: a punch; a mold, configured to move relative to the punch, and form a product having at least one curved surface from a workpiece placed between the punch and the mold; and a strain sensor, arranged in the mold, the strain sensor configured for measuring strain on the mold generated by press-forming the workpiece, wherein the strain sensor is positioned at a press-direction side relative to a radius end of a die shoulder on a material flow-out side when the mold is positioned at a lower dead point of press-forming, wherein a measurement point of the strain sensor is positioned within a region between surfaces which (i) intersect respective end portions of the curved surface of the mold, and (ii) are inclined away from the curved surface by 45 degrees relative to normal lines at the respective end portions if the curved surface of the mold is convex, or are inclined towards the curved surface by 45 degrees relative to normal lines at the respective end portions if the curved surface of the mold is concave, and wherein the strain sensor extends in the direction perpendicular to the press direction, and the strain sensor is configured to detect a friction force between the workpiece and the mold.