Patent ID: 8296110
Filing Date: 2012-10-23
Classification: B21D

Abstract:
1. A forming condition determination method for determining a forming speed of a pressing machine, comprising: a test press-forming step of providing a plurality of measurement points on a sheet material to conduct press-forming of the sheet material with the pressing machine at a predetermined forming speed; a strain distribution chart plotting step of plotting a strain state at each of the measurement points on the press-formed sheet material on a forming limit diagram including a forming limit curve of the sheet material to produce a strain distribution chart; and a forming speed determination step of defining a closest point plotted on the strain distribution chart to the forming limit curve as a specific measurement point, decreasing the forming speed to be slower than the predetermined forming speed when the specific measurement point is located in a bulge region, and increasing the forming speed to be faster than the predetermined forming speed when the specific measurement point is located in a draw region.