Contour-parallel offset tool path linking method of double-ring-shaped sections

Abstract

The invention discloses a contour-parallel offset tool path linking method of double-ring-shaped sections. Offset rings are divided into CW (clockwise) type offset rings, CCW (counter clockwise) I type offset rings and CCW (counter clockwise) II type offset rings; these three kinds of offset rings are searched based on inclusion relations, so that longest main links and a plurality of branch links are obtained; intersecting points are recorded, transitional connection points on the offset rings are solved one link by one link; a tool cuts in from the main link of the CCW I type offset rings, and performs counter clockwise machining from inner layers to outer edges; when meeting CCW I type local branch links, the tool firstly cuts into the innermost layer of the branch links and performs machining from inside to outside; the main link and branch links of the CCW II type offset rings are machined in a tool-retraction manner; and the main link and branch links of the CW type offset rings are machined in a tool-retraction manner along the clockwise direction of the rings from outer layers to inner layers. According to the method of the invention, the intersecting points of the branch links and main link are recorded repeatedly, and time when the main link and the branch links are connected together can be determined correspondingly. With the method adopted, the defect of frequent tool retraction in traditional line cutting machining can be effectively avoided, and a machining process more tends to be stable, and surface machining accuracy can be improved.

Description

technical field [0001] The invention relates to a method for processing geometric figures, in particular to a method for connecting ring-cut knife rails with a lake-shaped section in an island, and belongs to the application field of numerical control processing. Background technique [0002] The circular cutting tool track matches the contour of the workpiece to be processed, which can better ensure the machining accuracy of the contour, reduce the lifting of the tool and prolong the service life of the tool. Compared with the traditional line cutting method, it has great advantages. However, the generation of ring cutting tool path is more complicated, involving two major problems of offset ring generation and connection. Existing research mainly focuses on the situation that there are multiple "islands" in the figure, and there are relatively few studies on the "island with lake" cross-section, and this kind of problem is just relatively common, such as various stamps, fo...

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Problems solved by technology

Secondly, the existing circular cutting tool rail connection methods often have the problem of repeated cutting or overcutting (such as the literature [HAO Yong-tao, JIANG Li-li. Optimal algorithm for no tool-retractions contour-parallel offset tool-path linking[J] .Chinese Journal of Mechanical Engineering,2007,20(2):21-25] and [Yang Feng, Liao Wenhe, Dai Ning, et al. Algorithm for transition connection of tool rail ring with no jumping tool point and vertical line[J]. China Mechanical Engineering , 2013, 24(19): 2592-2596]), did not follow the principle of starting from the CCW inner ring (such as the literature [DAI N, DONG G L, LIAO W H, et al.Dental restoration contour-paralleloffset tool path links based on graph model[J].The International Journal of Advanced Manufacturing Technology,2013,66(1-4):555-563])

Furthermore, existing methods need to establish a complex tool path ring relationship tree, which involves complex tree structure traversal problems (such as literature [PARK S C, CHUNG Y C, CHOIB K. Contour-parallel offset machining without tool-retractions [J] Computer -Aided Design, 2003, 35(9):841-849])

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