A non-interference tool path generation method for machining transitional surfaces with flat end mills

Abstract

The invention discloses a method for generating interference-free flat-end milling cutter process path along the ridge direction of transitional surfaces. The method comprises the following steps: (1) initial machining tool path is set, a tool is processing along the ridges of transitional surfaces, a current tool contact is calculated to obtain effective curvature of the machining tool at the tool contact; (2) curvature interference analysis of transitional surface machining is carried out according to the effective curvature of the machining tool at the tool contact, tool bottom interference is analyzed, and the angle of the tool is deflected at the tool contact to obtain interference-free tool posture; (3) parameter calculation is carried out on the adjusted tool path so as to obtain step-length and cut row distance; and (4) adjacent tool path lines are calculated, including calculation of adjacent tool contacts and calculation of tool location data, and interference-free tool path is finally obtained. By the method, automatic planning of interference-free tool path can be realized; large cut row distance is obtained; cutting efficiency is high; machining surface roughness is low; surface fairness is good; and problems of low cutting efficiency, poor machining surface quality and the like by machining of a ball-end milling cutter are solved.

Description

technical field [0001] The invention belongs to the technical field of curved surface processing, and in particular relates to a method for generating tool tracks, which is suitable for numerical control processing of transitional curved surfaces. Background technique [0002] Some special transition surfaces are often involved in the design of curved surface products such as automobile bodies and aerospace vehicles, which play the role of beautiful decoration or enhanced rigidity to meet the requirements of product shape design. These special transition surfaces are divided into two types: equal-radius transition surfaces and variable-radius transition surfaces according to whether the curvature radii of each cross-section along the ridge are equal. The key to the processing of such transition surfaces lies in the generation of non-interfering tool paths in the transition area of ​​the surface. . Compared with three-axis machining, five-axis machining has more advantages d...

AI Technical Summary

Problems solved by technology

Compared with three-axis machining, five-axis machining has more advantages due to two more rotation axes, such as: better flexibility of tool movement, faster material removal rate and higher processing efficiency, etc. , but because of the constant change of the tool direction, the local interference phenomenon between the tool and the transition surface may occur at any time. It is of great significance to find an efficient method for generating non-interference tool paths in five-axis machining

[0003] At present, most of the processing methods for such transitional surfaces are three-axis CNC machining based on ball-end milling cutters. Since the effective cutting radius of each point of the ball-end milling cutter is the same, the cutting speed varies with the position of the tool contact on the blade. , the cutting speed at the end of the ball-end cutter is zero, the cutting performance is poor, the smoothness of the curved surface is also poor, the processing tool paths are very dense, and the processing efficiency of the ball-end cutter is low

At present, the main CAM commercial software such as UG, PowerMILL, etc. carry out tool path planning for surface processing, and the output tool position files cannot guarantee no interference. Instead, the interference checking part is put into the processing simulation for processing. If there is interference, it must be restarted. Adjusting or re-planning the tool trajectory generally requires multiple iterations to obtain the non-interference tool trajectory, which greatly reduces the processing efficiency and increases the processing cost

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