A post-processing method for free-form surface double-tool machining

Abstract

The invention discloses a post-processing method for twin-cutter machining of free-form surfaces, and the method comprises the following steps of arranging a first cutter and a second cutter on both sides of a workpiece to be processed, and laying out the cutters; separating cutter location files into cutting contact point positions and cutter axis vector information on the corresponding surfacesof the cutters; establishing a kinematic chain of the twin cutters of the machine tool, and establishing forward kinematics equations and cutter attitude and position expressions of the first cutter and the second cutter in the machine tool; calculating rotation angles of the workpiece rotary axis and the cutter pendulum axis, and the displacement of the corresponding linear axes of the first cutter and the second cutter to obtain the position relative to the processing coordinate system; continuously reading the cutter location files to form a numerical control program for the machine tool processing, and making the cutters complete the processing on both surfaces of the workpiece. The method provided by the invention solves the difficulty in generating a twin-cutter machining numerical control program at the rotation angle of the workpiece by converting the cutter location files into angular metric of two rotating axes and displacement of six linear axes of the machine tool, and converting the data into a machine tool-recognizable numerical control machining program.

Description

technical field [0001] The invention relates to the technical field of multi-axis numerical control machining of free-form surfaces, in particular to a post-processing method for double-knife machining of free-form surfaces. Background technique [0002] In the double-knife machining method, two tools process the curved surfaces on both sides of the workpiece at the same time, which is equivalent to reducing the cutting force of each tool on the workpiece, thereby reducing the deformation of the workpiece caused by the cutting force, which is conducive to improving the workpiece Machining quality, especially for free-form surfaces with complex shapes and thin walls, has a significant effect, and double-knife can improve processing efficiency compared with single-knife, but how to convert the tool position file of double-knife into NC code that can be recognized by the machine tool is a double-knife machining process prerequisite for realization. [0003] Because the two too...

AI Technical Summary

Problems solved by technology

At the same time, the two sides of the free-form surface are not symmetrical, which leads to the inconsistency of the contact point information on the two sides of the tool position file. It is necessary to ensure that the two tools and the two surfaces of the workpiece establish an accurate and unique correspondence.

[0004] However, the two tools of the double-tool machining free-form surface share the same workpiece rotation angle, and only the first tool has a swing angle, resulting in asymmetric degrees of freedom for the two tools; at the same time, the two tools share two rotation axes and six A linear axis, the corresponding relationship and calculation method between its tangent point and the angle of the rotary axis and the displacement of the linear axis have become problems that must be solved in the generation of NC codes for double-knife machining.

In addition, the free-form surface of complex shape has irregularities, which leads to the asymmetry of the tangent point information on both sides of the surface, and the tangent point information of a single tool cannot be used to calculate or map the displacement of all axes

None of the existing technologies can provide a solution to convert double-cut contact information into executable NC codes for double-knife machining

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