Precision machine tool dynamic performance optimization method based on frequency response calculation

Abstract

The invention relates to a precision machine tool dynamic performance optimization method based on frequency response calculation. The method comprises the following steps: establishing models of structural parts of a machine tool in three-dimensional designing software, and establishing a frequency-domain dynamic cutting force model; selecting structural feature dimensions that need to be optimized as optimization input parameters, so as to obtain frequency response functions of key parts of the machine tool under initial parameter conditions; simplifying frequency-domain dynamic cutting forces, and obtaining a simplified calculation equation, so as to achieve a calculation solution of frequency responses under a dynamic excitation force; calculating a dynamic cutting force under each rotation speed condition within a selected rotation speed range, further carrying out frequency response function response calculation to obtain vibration responses in sensitive directions of the machinetool at each rotation speed, and obtaining RMS values of vibration response functions through the discretization mode; and carrying out loop optimization calculation by using a vibration RMS within acertain rotation speed range as an optimization target and structural parameters as optimization variables, and finally obtaining a dynamic performance optimization result of the machine tool or a key component structure of the machine tool when the RMS is reduced to a preset target.

Description

technical field [0001] The invention relates to a method for optimizing the dynamic performance of a precision machine tool, in particular to a method for dynamic performance of a machine tool structure based on frequency domain vibration response calculation. Background technique [0002] The dynamic performance of the machine tool determines the vibration resistance of its processing, and even determines the application prospect of high-speed precision machining technology. High-performance CNC machine tools require good dynamic performance, and dynamic performance optimization technology can improve the dynamic performance by improving the parameters of the structure. The previous dynamic performance optimization methods mainly considered a single index such as mass, dynamic stiffness, and modal frequency as the optimization target. The optimization results can only reflect the improvement effect of the inherent characteristic parameters, and cannot directly reflect the p...

AI Technical Summary

Problems solved by technology

However, there are obvious defects: (1) With the modal frequency as the optimization target, the overall improvement level of its dynamic performance is limited, and the overall reduction of vibration cannot be achieved; (2) The dynamic excitation of precision machine tools cannot reflect the vibration of different speed ranges (3) The optimization result is only the improvement of the modal frequency, and it is difficult to reflect the improvement effect of the dynamic performance of the machine tool process

The disadvantages of this method are: (1) The harmonic response analysis does not fully consider the influence of the dynamic excitation force on the entire frequency domain; (2) The premise of the optimal design is based on regularity analysis, which cannot be quantified; (3) The weak link Optimize the main driven stiffness level, which cannot correspond to the vibration of the processing technology

The obvious disadvantages of this method are: (1) it is mainly aimed at lightweight operation, and the dynamic performance improvement of precision machine tools is limited; (2) the optimized method and results cannot effectively reduce the vibration of the machining process

[0010] 2. The optimization method is aimed at a specific frequency, or the specific speed of the vibrating machine tool, and the influence of the optimization method on the entire frequency (speed) range cannot be considered

[0011] 3. The optimization method improves the vibration resistance to a certain extent, but lacks the overall improvement of the vibration in the process

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