Inverse Simulation of Sinking Electrical Discharge Machining with Multi-step Toolpaths

The inverse simulation of sinking electrical discharge machining (sinking EDM) is improved so that it can be applied to multi-step machining. In multi-step machining, there are various possible machining paths, but there are paths for which the solution of the inverse simulation cannot be obtained. This is the case when there is a step where a hollow space is created between the tool electrode and the workpiece. In this case, it is sufficient to add to the shape of the workpiece an area that fills the space for this step. Then, by adding a step that removes the added area at the end of the toolpath, the inverse simulation can be performed correctly, and the tool electrode shape that can machine the desired shape can be obtained. The validity of the proposed method was verified by machining experiments.