Machining of complex-shaped parts with guidance curves

TL;DR

This paper introduces a guidance curve strategy for high-speed machining of complex-shaped parts, improving tool path stability and surface quality by decomposing features based on curvature analysis and intermediate guidance curves.

Contribution

It proposes a novel method for defining guidance curves using intermediate curves and a four-step process to enhance machining of complex shapes.

Findings

Guidance curve strategy improves tool path stability.

Decomposition based on curvature enhances surface integrity.

Experimental validation shows better performance with the proposed method.

Abstract

Nowadays, high-speed machining is usually used for production of hardened material parts with complex shapes such as dies and molds. In such parts, tool paths generated for bottom machining feature with the conventional parallel plane strategy induced many feed rate reductions, especially when boundaries of the feature have a lot of curvatures and are not parallel. Several machining experiments on hardened material lead to the conclusion that a tool path implying stable cutting conditions might guarantee a better part surface integrity. To ensure this stability, the shape machined must be decomposed when conventional strategies are not suitable. In this paper, an experimental approach based on high-speed performance simulation is conducted on a master bottom machining feature in order to highlight the influence of the curvatures towards a suitable decomposition of machining area. The decomposition is achieved through the construction of intermediate curves between the closed boundaries of the feature. These intermediate curves are used as guidance curve for the tool paths generation with an alternative machining strategy called "guidance curve strategy". For the construction of intermediate curves, key parameters reflecting the influence of their proximity with each closed boundary and the influence of the curvatures of this latter are introduced. Based on the results, a method for defining guidance curves in four steps is proposed.