1997 年 47 巻 7 号 p. 378-384
The process of CNC incremental forming is suitable for small-lot production of thin shell parts, since a variety of forming configurations can be realized by changing only the tool-path contour. A suitable tool-path schedule has been found for cylindrical shell having non-uniform wall-thickness, but has not been illuminated previously for those having uniform wall-thickness. In order to produce the cylindrical shell having uniform wall-thickness, a new tool-path schedule in which a cylindrical shell is formed from a flat blank by means of conical stretch-expanding with a single tool-path at first stage and subsequent incremental forming with parallel multi tool-path at second stage is proposed and its possibility is experimentally investigated using blanks of 1100 commercially pure aluminum sheet. It is found that the cylindrical shell having uniform wall-thickness could be formed from the aluminum blank by means of the proposed tool-path schedule. Experimental results also shows that the success of the process depends much on the condition of moving direction of tool at the second stage.