Tool axis vector fairing method based on kinematics characteristics of swivel feeding shaft of machine tool

Abstract

The invention belongs to the technical field of complex surface part high-precision and high-efficiency milling, and relates a tool axis vector fairing method based on the kinematics characteristics of a swivel feeding shaft of a machine tool. The method comprises the steps: taking equal residual height as a constraint to generate a processing tool path according to the geometric features of a curved surface; building a coordinate conversion relation between a workpiece coordinate system and a machine tool coordinate system, converting a tool axis sequence corresponding to a tool contact pointinto a corner sequence of the swivel feeding shaft of the machine tool, and determining a to-be-optimized section according to the angle changes of the swivel feeding shaft of the machine tool; calculating tool axis vector coordinates corresponding to the tool contact point in the to-be-optimized section based on a quaternion method, carrying out the fairing of a corner curve of the swivel feeding shaft of the machine tool through the least square fitting method, and carrying out the interference checking and adjustment of the optimized cut axis vector. The method effectively reduces the motion abrupt changes of the swivel feeding shaft of the machine tool in a machining process, achieves the steady machining, and improves the surface machining quality.

Description

technical field The invention belongs to the technical field of high-precision and high-efficiency milling of complex curved surface parts, and relates to a tool axis vector smoothing method based on the kinematics characteristics of a rotary feed axis of a machine tool. Background technique Complex curved surface parts are widely used in various fields such as aerospace, automobiles, and ships. How to realize high-quality and efficient processing of complex curved surface parts is a hot and difficult point of current research. Compared with three-axis CNC machining, five-axis CNC machining adds two rotation axes. The contact state between the tool and the machined surface can be controlled by adjusting the included angle of the tool relative to the local coordinate system to ensure the processing quality and efficiency of the part, and at the same time avoid the gap between the tool and the workpiece. local and global interference. At present, the direction of the tool axi...

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Problems solved by technology

However, this method has a large amount of calculation and does not consider the kinematics of the machine tool's rotary feed axis during the optimization process, which has great limitations.

The literature by Zhou Bo et al. "Research on tool axis vector optimization method for five-axis CNC machining of complex curved surfaces", Chinese Journal of Mechanical Engineering, 2013, 49(7), 184-192, by inserting tool contacts in the non-interference area, in the interference area The improved C-space method is used to generate a smooth tool axis vector. This method can handle global interference and local interference, but inserting a tangential point reduces the actual feed rate and affects processing efficiency. It is not suitable for high-precision and high-efficiency processing.

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