A Method of Equal Error Tool Path Generation for Five-axis Machining of Parametric Curved Surface with Flat Bottom Tool

Abstract

The invention discloses a method for generating equal-error tool tracks for five-axis machining of parametric curved surface flat-bottomed knives. First, the curved surface model to be processed is imported, and parameter information such as the processing tool, the maximum allowable value of the approach error, and the line distance are set; and then the knife is planned according to the line distance. The contact curve, the tool contact curve calculates the initial step size according to the linear error, obtains the discrete tool contact and calculates the tool position point and the tool axis vector of the tool contact point; the tool movement between adjacent tool position points The envelope surface and the tool contact trajectory are replaced by discrete tool bottom circles and tool contact sets, and a calculation method for the approximation error of two adjacent tool positions is proposed; the approximation error is compared with the maximum allowable value, and the step size is adjusted so that The approach error between adjacent tool positions is within the set range, so that equal error tool paths are obtained.

Description

technical field [0001] The invention belongs to the technical field of computer aided manufacturing (Computer Aided Manufacturing, CAM), and in particular relates to a method for generating equal-error tool paths for five-axis machining of parametric curved surface flat-bottomed knives. Background technique [0002] As a typical free-form surface, parametric surfaces are widely used in the design of products with complex shapes, such as covering parts and molds. Different from the commonly used parametric surface tool path generation methods such as the parameter method and the equal step method, the equal error tool path makes the approach error equal to the maximum allowable value or within the set interval by controlling the distance between adjacent tool contacts, so that Maximize the step length, minimize the number of tool contacts / tool ​​points, and effectively reduce the number of redundant tool paths. [0003] The equal-error CNC machining tool path has obvious adv...

AI Technical Summary

Problems solved by technology

The geometric characteristics of the approach error of the five-axis flat bottom knife are relatively complex, and the calculation of the equal error knife contact is difficult, and each knife contact needs to be calculated one by one based on the previous knife contact.

[0004] The invention patent with the Chinese patent application number CN201910839404.2 discloses a nonlinear error control method based on eight-parameter five-axis linear interpolation, which is used to solve the nonlinear error of the linear trajectory of the tool contact during five-axis linear interpolation. control problem

The actual approximation error in five-axis machining is determined by both nonlinear error and linear error, but it is not simply superimposed, but needs to obtain the real tool motion envelope and local surface information for calculation, because these two invention patents are based on the existing There is an optimization process for the nonlinear error of the tool path, so it cannot be used for the calculation of the approximation error and the generation of the equal error tool path

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