Kazuyoshi Kondo

Development of a New Burr-Free Shearing Process Utilizing Necking Deformation.

Removal of burrs is necessary because they cause several problems during service. However, neither deburring processes nor existing burr-free shearing processes have been applied succesfully to thin sheet metals. In order to solve this problem, a new burr-free shearing method is proposed. It is based on the idea that the burr-side edge will roll over by necking deformation when the partially sheared material is pulled apart. This paper describes realization of this principle and its application to thin steel sheets. Three methods were attempted for 0.2-mm-thick alminium sheets and 0.14-mm-thick steel sheets. Deformation behavior, application range, and quality of the sheared edge were investigated. As a result, it was found that the method utilizing stretching by a conical die is the most desirable one for practical use.