Contour-parallel tool path generation for three-axis mesh surface machining based on one-step inverse forming

Abstract

Recently, mesh surfaces have become the focus of considerable interest due to its simplicity for data exchange and geometric computation. However, for mesh surface machining, there are few tool path planning strategies but iso-planar method. In this article, a contour-parallel tool path method is presented for machining complicated mesh surfaces with holes or islands by introducing a so-called one-step inverse approach based on physical plastic deformation of metal materials. By rapidly simulating for the inverse forming process of sheet metal of auto-body panels, the machined surfaces are flattened into its initial flat blank on which the cutter contact points are calculated by iteratively offsetting the inner and outer contours of the blank. Then, using the mapping from the machined surfaces to the blank as a guide, the planar offset curves without self-intersection are inversely mapped onto the original mesh surfaces, forming the final contour-parallel tool paths. Benefiting the flattening method based on one-step inverse approach, the task of generating tool paths is reduced from a physical surface to a plane so that geometric computation of tool path generation is greatly simplified, especially for self-intersection elimination in offset curves. Moreover, a new data structure of offset curve is also introduced, which is used to effectively compute the self-intersections. The proposed method has been tested on several sample surfaces, and the experimental results show that the proposed method can deal with complicated mesh surfaces with holes or islands and is also more efficient compared with the traditional methods.

Process simulation for five-axis grinding machining using an analytical method

“…In this equation, P 1 c ð Þ is the generatrix illustrated in Figure 2, and N i, 3 ð Þ and P i are the basic function and control points of the B-spline curve, respectively, is the basic parameter of the B-spline curve. When the curve of the wheel is obtained, the rotational surface which is the wheel surface can be calculated using the rotational matrix, then this surface can be calculated using the equation of…”

“…Five-axis machining process is very important for key structures and workpieces with sculptured surfaces. [1][2][3] Because these parts are widely used in fields such as aerospace and mould, etc. The demands of these parts' surfaces are more and more stringent and the machining for these surfaces is more and more difficult.…”

Generating the tool path directly with point cloud for aero-engine blades repair

“…In the field of advanced machining, the technology of constructing machining trajectories directly with measured data has been gradually developed in recent years. For these methods, machining trajectories could be generated with point cloud directly, [10][11][12] including three-axis [13][14][15] and five-axis 12,16,17 tool path. The improvement could eliminate the surface fitting operation on measured data, as well as the requirement of using CAM software for creating machining trajectories.…”