CN-121615282-B - Optimal blade design method for cutter for inhibiting flutter under specific working condition

CN121615282BCN 121615282 BCN121615282 BCN 121615282BCN-121615282-B

Abstract

The invention relates to the technical field of cutter blade type design, and particularly discloses a cutter optimal blade type design method aiming at vibration suppression under specific working conditions, comprising the following steps of S1, setting a helix angle and an initial tooth pitch of a cutter as optimizing parameters; S2, calculating critical stable axial cutting depth through a critical cutting depth calculation function under a specific working condition based on the optimizing parameters, and S3, optimizing by taking the critical axial cutting depth as an adaptive function through a particle swarm algorithm, so as to find a local optimal blade type. The optimal blade type design method of the cutter aiming at the vibration suppression under the specific working condition is adopted, the complete SLD under the overall rotating speed is not required to be drawn, the calculation efficiency is greatly improved, the influence of the spiral angle and the pitch on the vibration suppression can be comprehensively considered, the blade type optimization of the cutter is carried out in a wider blade type space, and the vibration suppression requirement of the specific working condition is accurately matched.

Inventors

SHEN BIN
AI DI
WANG CHENGHAN
YUE TING
CHEN SULIN

Assignees

上海交通大学

Dates

Publication Date: 20260508
Application Date: 20260202

Claims (8)

1. The design method of the optimal blade type of the cutter for inhibiting the flutter under the specific working condition is characterized by comprising the following steps of: s1, setting a spiral angle and an initial tooth pitch of a cutter as optimizing parameters; S2, calculating critical stable axial cutting depth through a critical cutting depth calculation function under specific working conditions based on optimizing parameters, wherein the specific working conditions comprise the current rotating speed of the cutter under the milling condition of the non-ball-head cutter And radial immersion angle of milling process ; S3, optimizing by using critical axial cutting depth as an adaptive function through a heuristic algorithm, and finding out a local optimal blade shape; s2, comprehensively optimizing parameters and specific working conditions to obtain critical stable axial cutting depth through critical cutting depth calculation function calculation Critical stable axial depth of cut The calculation formula of (2) is as follows: ; Wherein, the To the total number of cutting edges on the tool involved in the cutting process, For the feature values in the dynamic cutting process, For the normal coefficient of the cutting force, Is the first The cutting angle of the individual cutting edges, The vibration frequency is the vibration frequency when the vibration occurs in the cutting process; Is the first The tooth passing period of each blade element.
2. The method for designing an optimal blade shape of a cutter for suppressing chatter vibration under a specific condition according to claim 1, wherein in S1, the method comprises the steps of Defining the point initial pitch of the cutting edges, i.e. the axial angle between each cutting edge, by The distribution of (2) defines the helix angle of each cutting edge of the tool, i.e. the angle between the normal to each edge and the arbor.
3. The method for designing an optimal blade shape of a cutter for chatter suppression under specific conditions according to claim 1, wherein in S2 Milling conditions include side milling, end milling and plunge milling.
4. The method for designing an optimal blade shape of a tool for suppressing chatter under a specific condition according to claim 3, wherein in S2, a critical stable axial cutting depth is performed Before calculation, determining the geometric shape of the cutter, the FRF frequency domain response function of the dynamic characteristic of the cutter, the cutting force coefficient and the current rotating speed of the cutter The geometry of the tool includes diameter, edge angle, edge radius and edge rake angle.
5. The method for designing an optimal blade shape of a tool for suppressing chatter under a specific condition as defined in claim 4, wherein in S2, critical stable axial cutting depth is performed Before calculation, the method also comprises the step of reading cutter cutting edge characteristic parameters from a configuration file provided by a user, wherein the cutter cutting edge characteristic parameters comprise the number of cutting edges, the discrete element length of the cutting edge, the spiral angle direction, the rotation direction, whether the cutting edge exists at the bottom or not and the distance between the starting point of the cutting edge and the blank space, the three-dimensional coordinates, the normal vector and the cutting vector of each cutting edge element, and the material and dynamics parameters comprise natural frequencies Coefficient of stiffness Damping ratio Coefficient of cutting force Angle of force 。
6. The method for designing an optimal blade shape of a cutter for suppressing chatter under a specific condition according to claim 1, wherein in S2, the axial cutting depth is stabilized at a critical point In the calculation process, definition Is the flutter factor Wherein Is the first Cutting edge number Cutting into slices with variable helix angle and different heights along the cutter shaft, and cutting into slice layers with different flutter factors With corresponding helix angle Adding and averaging cosine values of (2) to obtain critical stable axial depth of cut Denominator in calculation formula Wherein Namely, is 。
7. The method for designing optimal blade shape of cutter for vibration suppression under specific working conditions as set forth in claim 1, wherein in S3, heuristic algorithm uses initial pitch of cutter and helix angle of each blade as input of optimization algorithm, explores in parameter space, calculates critical depth of cut of each group of parameters in optimizing process by critical depth of cut calculation function, selects a group of parameters with maximum critical depth of cut as optimal parameter combination to obtain optimal helix angle And an optimal initial pitch The combination of parameters was used as the optimal blade profile.
8. The method for designing an optimal blade shape of a cutter for vibration suppression under specific working conditions according to claim 7, wherein in S3, a particle swarm optimization algorithm PSO is selected as a heuristic algorithm, each problem to be solved is regarded as a particle in a search space, and the optimizing process is as follows: initializing a population of randomly located and velocity particles; In the iterative process, each particle calculates an fitness value according to the current position of the particle, and compares the fitness value with the historical optimal position of the particle and the global optimal position of the whole population; The particle then dynamically adjusts its own forward speed and position according to its own historical optimal position and the global optimal position of the whole population; after iteration, the particle swarm finds the optimal solution of the problem.

Description

Optimal blade design method for cutter for inhibiting flutter under specific working condition Technical Field The invention relates to the technical field of cutter blade type design, in particular to a cutter optimal blade type design method aiming at vibration suppression under specific working conditions. Background As a problem that the machining field is most complicated and affects the machining quality most, the problem of chatter during machining has been paid attention to by the machining field scholars. Chatter is generated by the mutual excitation process of cutting thickness and cutting force, which are changed in the cutting process, and the current suppression method for chatter can be mainly divided into active suppression and passive suppression, and the essence of the two suppression modes is that the regeneration mechanism of the mutual excitation is destroyed by some means. In the aspect of passive inhibition, the main method at present is to collect signals in the processing process, such as force signals, acoustic signals, acceleration signals and the like, analyze the signals to judge whether chatter occurs in the processing process, and modify process parameters if the chatter occurs so as to achieve the purpose of eliminating the chatter. The limitation of this approach is that only post-chatter suppression can be performed, and the process design cannot be performed before machining to prevent chatter during machining. In the aspect of active inhibition, the current main method is to actively improve the critical axial cutting depth of the chatter by means of modifying the rotating speed, adding a damper, modifying the blade of a cutter and the like, so that the processing efficiency is improved while the surface quality is ensured. The current working condition can be in a higher critical stable cutting depth by referring to SLD, however, the rotating speed is changed when the working condition is changed, so that the requirements on the performance of the machine tool are higher, different cutters have different recommended rotating speeds, if the actual rotating speed is far away from the recommended rotating speed, the abrasion or collapse of the cutters can be accelerated, the damper is additionally arranged to pull the numerical value of the critical axial cutting depth at the global rotating speed, but the damper is additionally arranged to the machine tool spindle, the dynamic characteristic of the machine tool spindle is damaged, the SLD is influenced, the critical stable cutting depth of the cutter blade type can be improved at the specific rotating speed, other influences are not brought to the dynamic characteristic of the machine tool spindle, and no special requirements are brought to the performance of the machine tool, so that a plurality of students can put into the study of inhibiting the chatter by modifying the cutter blade type. At present, the optimal design of the cutter blade type is mainly focused on the design of tooth pitch, and partial scholars consider the cutter helix angle and the cutter tooth pitch to carry out cutter design at the same time, but the optimization is carried out by deep learning or heuristic algorithm, and the physical mechanism behind the cutter blade type is not explained. In addition, when the flutter frequency of the cutter is changed after the blade type is changed, the new flutter frequency needs to be searched in an iterative mode, and the critical axial depth under the specific rotating speed can be obtained by completely drawing the SLD under all the rotating speeds, so that the process is tedious and time-consuming. Disclosure of Invention The invention aims to provide a method for designing an optimal blade type of a cutter for inhibiting flutter under a specific working condition, which designs a critical axial cutting depth calculation function of any blade type without drawing a complete SLD of a global rotating speed, and performs optimization by using a particle swarm algorithm based on the function, so as to design the optimal flutter inhibiting blade type of a comprehensive helix angle and a comprehensive pitch under the specific working condition. In order to achieve the above purpose, the invention provides a design method of an optimal blade type of a cutter aiming at the inhibition of flutter under a specific working condition, which comprises the following steps: s1, setting a spiral angle and an initial tooth pitch of a cutter as optimizing parameters; S2, calculating critical stable axial cutting depth through a critical cutting depth calculation function under specific working conditions based on optimizing parameters, wherein the specific working conditions comprise the current rotating speed of the cutter under the milling condition of the non-ball-head cutter And radial immersion angle of milling process; And S3, optimizing by using the critical axial cutting depth as an adaptive function through a heurist