| 摘要 |
PROBLEM TO BE SOLVED: To evaluate the deterioration degree of metal molds such as punches in real time under the state, wherein a press working machine is operated. SOLUTION: At least a pair of metal moldes are compressed to a material. Thus, the deterioration degree of the metal molds is evaluated with a sound signal P generated at the deformation of the material when the press working involving cutting or bending of the material is performed. In this case, when the amplitude, the distribution width Twa and the area A of the sound signal, become large, it is judged that the metal molds are deteriorated more. The reference signal, which is obtained by averaging the sound signals sampled when the metal molds are normal, and the waveform to be measured among the sound signal P are compared. When the waveform to be measured exceeds the reference waveform by more than the specified value, it can be evaluated that the metal molds have reached the replacing time. |
