Press-formed article manufacturing method

A press-formed article manufacturing method for manufacturing a press-formed article by performing press forming with use of a press die on a blank extracted from a metal sheet having a shape variation, the press-formed article manufacturing method comprising:

• a reference press-formed article shape acquisition step of acquiring a press-formed article shape after die release as a reference press-formed article shape by performing press forming analysis to perform press forming with use of a flat blank model having a flat shape by a predetermined die model set based on a shape of a target press-formed article;
• a first actual blank press-formed article shape acquisition step of acquiring a press-formed article shape after die release as a first actual blank press-formed article shape by generating a first actual blank model based on measurement data acquired by measuring a first actual blank extracted from the metal sheet having the shape variation, and performing press forming analysis to perform press forming with use of the generated first actual blank model by the predetermined die model;
• a first actual deviation amount acquisition step of finding a deviation portion where the reference press-formed article shape and the first actual blank press-formed article shape deviate from each other, and a first actual deviation amount as a deviation amount in the deviation portion, by comparing the reference press-formed article shape with the first actual blank press-formed article shape;
• a second actual blank press-formed article shape acquisition step of acquiring a press-formed article shape after die release as a second actual blank press-formed article shape by generating a second actual blank model of at least one type based on measurement data acquired by measuring a second actual blank extracted from a portion of the metal sheet having the shape variation which portion is different from a portion from which the first actual blank is extracted, and performing press forming analysis to perform press forming with use of the generated second actual blank model by the predetermined die model;
• a second actual deviation amount acquisition step of finding a deviation portion where the reference press-formed article shape and the second actual blank press-formed article shape of the at least one type deviate from each other, and a second actual deviation amount as a deviation amount in the deviation portion, by comparing the reference press-formed article shape with the second actual blank press-formed article shape of the at least one type;
• a measures-required portion specifying step of specifying, as measures-required portions, respective portions of the press-formed article which portions correspond to a portion having a deviation amount exceeding a predetermined threshold as the first actual deviation amount and a portion having a deviation amount exceeding the predetermined threshold as the second actual deviation amount;
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• a forming accuracy improving step of correcting a shape of at least either one selected from a forming surface of an actual die as a press die to be used in manufacture of the press-formed article and an actual blank as the blank to be used in the manufacture of the press-formed article in such a manner as to reduce the deviation amounts in the measures-required portions specified in the measures-required portion specifying step.