Papers by Author: Yuuya Masaki

Abstract: This paper describes for verification of bending effect on the performance of the heightwise-asymmetric plunge cutting method, which was composed of an upper-wedge blade and a lower-wedge blade embedded in the lower-counter plate, in order to apply this cutting method for a polycarbonate (PC) thick sheet. By varying the tip angle α_U and the tip thickness w_U of lower blade embedded in the counter plate, and combining a standard steel cutting rule of 42° center bevel blade, the sheared profile of two kinds of PC worksheet (the thickness of which was chosen as t=0.5, 1.0 mm) was experimentally investigated. Through this experiment, it was found that the sheared profile (the necked height η_n, the upper inclination angle β, the lower inclination angle β_U) of PC worksheet was primarily characterized by the normalized lower tip thickness w_U/t. The difference of sheared profile was explained using the Prandtls punching solution for two kinds of PC worksheet. Furthermore, by varying the heightwise position of lower blade tip, the bending effect on sheared profile of worked sheet was experimentally verified.

Abstract: Asymmetric plunge cutting by using grooved knife edge plate was proposed for advanced die cutting of a polycarbonate (PC) sheet. By varying the tip angle U and the tip thickness wU of knife edge in the counter plate, and combining a standard steel cutting rule of 42° center bevel blade, a cutting load response of PC sheet was investigated and also that deformation was observed by a CCD camera. Through this works, the followings were found: 1) there were two deformation modes of sheared profile. 2) The tip thickness wU was a primary factor, compared to the tip angle of U. 3) The equivalent wedge angle effect was revealed with respect to the upper/lower angles  and U, while the PC sheet was bent up by the lower knife indentation.