阅读说明：本技术 一种长轴距变直径复杂薄壁结构件的精密加工方法 (Precision machining method for long-wheelbase variable-diameter complex thin-wall structural part ) 是由 赵东国 张泽贤 于 2021-07-23 设计创作，主要内容包括：一种长轴距变直径复杂薄壁结构件的精密加工方法,包括以下步骤：S1、粗加工：包括划线标记、粗车外形、划线标记、粗铣外形；S2、应力检测处理：通过振动时效处理内应力,通过对比来验证时效处理对结构件的作用效果；S3、建立刚度分析模型：对结构件进行刚度分析,并设计专用工装；根据结构件与专用工装来建立刚度分析模型；S4、机械加工仿真：通过大量切削参数样本进行机械加工仿真,得出最优的仿真参数；本发明通过优化加工工艺流程,增加频谱谐波时效处理,有效地降低了结构件加工后的内应力；通过改善切削加工的刀具,以及优化切削加工的参数,提高了切削加工的精度以及缩短了切削加工的时间,从而提高了切削加工的效率。(A precision machining method for a long-wheelbase variable-diameter complex thin-wall structural part comprises the following steps: s1, rough machining: the method comprises marking, rough turning, marking and rough milling; s2, stress detection processing: verifying the effect of aging treatment on the structural member by performing vibratory aging treatment on the internal stress and comparing; s3, establishing a rigidity analysis model: carrying out rigidity analysis on the structural member, and designing a special tool; establishing a rigidity analysis model according to the structural part and the special tool; s4, mechanical processing simulation: performing mechanical processing simulation through a large number of cutting parameter samples to obtain optimal simulation parameters; according to the invention, the internal stress of the processed structural member is effectively reduced by optimizing the processing process flow and increasing the frequency spectrum harmonic aging treatment; by improving the cutting tool and optimizing the cutting parameters, the cutting precision is improved, the cutting time is shortened, and the cutting efficiency is improved.)

1. A precision machining method for a long-wheelbase variable-diameter complex thin-wall structural part comprises the following steps:

s1, rough machining: the method comprises marking, rough turning, marking and rough milling;

s2, stress detection processing: verifying the effect of aging treatment on the structural member by performing vibratory aging treatment on the internal stress and comparing;

s3, establishing a rigidity analysis model: carrying out rigidity analysis on the structural member, and designing a special tool; establishing a rigidity analysis model according to the structural part and the special tool;

s4, mechanical processing simulation: the machining simulation is carried out through a large number of cutting parameter samples,

obtaining optimal simulation parameters;

s5, finishing: the method comprises the steps of semi-finish turning, finish milling of the shape, finish turning of a standard, finish milling and punching, and tapping by a bench worker;

s6, structural part detection: detecting whether the processed structural part is qualified or not;

s6.1, when the structural member is detected to be unqualified, returning to the step S1 for processing again;

s6.2, when the structural member is detected to be qualified, finishing the processing.

2. The method for precisely machining the long-wheelbase variable-diameter complex thin-wall structural member as claimed in claim 1, wherein the step S2 comprises the following steps:

a1, residual stress detection: after the rough machining is finished, carrying out residual stress detection on the structural member;

a2, collecting physical parameters of the structural part: collecting physical parameters of the structural component;

a3, establishing a mechanical property model: establishing a mechanical property model through physical parameters of a structural part;

a4, vibration aging treatment: carrying out vibration aging treatment according to the mechanical property model;

a5, residual stress detection: carrying out residual stress detection on the structural member again;

a6, comparison with initial sample: comparing the sample detected in step A1 with the sample detected in step A5; when the stress effect of the vibration aging treatment is poor, returning to the step A4 to readjust the vibration parameters, and then performing the vibration aging treatment again; and when the stress effect of the vibration aging treatment is excellent, the next step is carried out.

3. The method for precisely machining the long-wheelbase variable-diameter complex thin-wall structural member as claimed in claim 1, wherein the step S3 comprises the following steps:

b1, structural member rigidity analysis and special tool design: the structural member is subjected to a rigidity analysis,

and designing a special tool;

b2, establishing a rigidity analysis model: establishing a rigidity analysis model according to the structural part and the special tool;

b3, model analysis results: the stiffness analysis model is analyzed, and the results are viewed:

b3.1, when the analysis result is poor, returning to the step B1 again to adjust the tool parameters; or returning to the step B2 again to adjust the model parameters;

b3.2, when the analysis result is excellent, the next step is carried out.

4. The method for precisely machining the long-wheelbase variable-diameter complex thin-wall structural member according to claim 1, wherein the step S4 comprises the following steps:

c1, carrying out a large number of cutting tests on the structural member to obtain a cutting parameter sample;

c2, performing machining simulation by cutting the parameter sample;

and C3, determining the optimal simulation parameters from the step C2.

5. The method as claimed in claim 4, wherein the step S4 is performed by a plurality of cutting tests to optimize the process flow and obtain the optimal cutting parameters for cutting the structural member and the optimal cutting tool for the structural member.

6. The precision machining method for the long-wheelbase variable-diameter complex thin-wall structural part according to claim 5, wherein the optimal cutting parameters of the structural part comprise cutting parameters of an inner arc surface of a large end of the structural part, cutting parameters of a lightening groove of a middle flange surface of the structural part and cutting parameters of an inner wall of a small end of the structural part; the cutting parameters of the inner arc surface of the large end of the structural part are as follows: vc is 78.5, N is 2500, F is 800, Ap is 0.25; the cutting parameters of the structural member intermediate flange surface lightening groove are as follows: vc is 78.5, N is 3250, F is 1250, Ap is 0.2; the cutting parameters of the inner wall of the small end of the structural part are as follows: vc is 78.5, N is 2500, F is 1500, Ap is 1.0.

7. The method for precisely machining the long-wheelbase variable-diameter complex thin-wall structural part according to claim 5, wherein the optimal cutting tool for the structural part comprises a cutting tool for an inner arc surface of a large end of the structural part, a cutting tool for a lightening groove on a middle flange surface of the structural part and a cutting tool for an inner wall of a small end of the structural part; the cutting tool of the arc surface at the inner side of the large end of the structural part is a 63mm cutter handle clamping 10mm milling cutter combined tool; the cutting tool of the structural member middle flange surface lightening groove is a hot-mounted lengthened damping tool; the cutting tool of the inner wall of the small end of the structural part is a T-shaped three-edge milling cutter with the diameter of 50 mmT.

8. The method for precisely machining the long-wheelbase variable-diameter complex thin-wall structural member according to claim 2, wherein the vibration aging treatment of the step A4 is a frequency spectrum harmonic aging treatment.

9. The method for precisely machining the long-wheelbase variable-diameter complex thin-wall structural member according to claim 3, wherein the special tool in the step B1 is a low-stress clamping tool.

Technical Field

The invention discloses a precision machining method for a long-wheelbase diameter-variable complex thin-wall structural part, relates to the technical field of machining, and particularly relates to a precision machining method for a long-wheelbase diameter-variable complex thin-wall structural part.

Background

The long-wheelbase variable-diameter complex thin-wall structural part in the prior art has the following problems that the casting machining allowance is large due to the complex structure of parts, the machining deformation is difficult to control, the phenomena of cutter back off, vibration and the like are easy to generate during machining, and the high-precision part is easy to be out of tolerance; the internal features are more, the structure is more complex, the feature shape and the position are not easy to process, the feature shape and the position are all thin-wall structures, the appearance has a structure with multiple diameter changes, the extending feature of the inner cavity is complex, and the clamping and the processing are easy to deform; the design precision requirement is high, a plurality of high-precision pin holes exist, the form and position and dimensional tolerance of a plurality of positions are 0.01mm, the angular precision is +/-1', and the precision is close to the self precision of a machine tool; the conventional machining method has difficulty in ensuring the machining accuracy.

Disclosure of Invention

The invention aims to provide a precision machining method for a long-wheelbase variable-diameter complex thin-wall structural member, which aims to overcome the problems in the prior art.

In order to solve the problems, the technical scheme adopted by the invention is as follows: a precision machining method for a long-wheelbase variable-diameter complex thin-wall structural part comprises the following steps:

s1, rough machining: the method comprises marking, rough turning, marking and rough milling;

s2, stress detection processing: verifying the effect of aging treatment on the structural member by performing vibratory aging treatment on the internal stress and comparing;

s3, establishing a rigidity analysis model: carrying out rigidity analysis on the structural member, and designing a special tool; establishing a rigidity analysis model according to the structural part and the special tool;

s4, mechanical processing simulation: performing mechanical processing simulation through a large number of cutting parameter samples to obtain optimal simulation parameters;

s5, finishing: the method comprises the steps of semi-finish turning, finish milling of the shape, finish turning of a standard, finish milling and punching, and tapping by a bench worker;

s6, structural part detection: detecting whether the processed structural part is qualified or not;

s6.1, when the structural member is detected to be unqualified, returning to the step S1 for processing again;

s6.2, when the structural member is detected to be qualified, finishing the processing.

As a further preferable embodiment of the present invention, the step S2 includes the following steps: a1, residual stress detection: after the rough machining is finished, carrying out residual stress detection on the structural member;

a2, collecting physical parameters of the structural part: collecting physical parameters of the structural component;

a3, establishing a mechanical property model: establishing a mechanical property model through physical parameters of a structural part;

a4, vibration aging treatment: carrying out vibration aging treatment according to the mechanical property model;

a5, residual stress detection: carrying out residual stress detection on the structural member again;

a6, comparison with initial sample: comparing the sample detected in step A1 with the sample detected in step A5; when the stress effect of the vibration aging treatment is poor, returning to the step A4 to readjust the vibration parameters, and then performing the vibration aging treatment again; and when the stress effect of the vibration aging treatment is excellent, the next step is carried out.

As a further preferable embodiment of the present invention, the step S3 includes the following steps:

b1, structural member rigidity analysis and special tool design: carrying out rigidity analysis on the structural member, and carrying out special tool design;

b2, establishing a rigidity analysis model: establishing a rigidity analysis model according to the structural part and the special tool;

b3, model analysis results: the stiffness analysis model is analyzed, and the results are viewed:

b3.1, when the analysis result is poor, returning to the step B1 again to adjust the tool parameters; or returning to the step B2 again to adjust the model parameters;

b3.2, when the analysis result is excellent, the next step is carried out.

As a further preferable embodiment of the present invention, the step S4 includes the following steps:

c1, carrying out a large number of cutting tests on the structural member to obtain a cutting parameter sample;

c2, performing machining simulation by cutting the parameter sample;

and C3, determining the optimal simulation parameters from the step C2.

As a further preferred embodiment of the present invention, in step S4, the machining process is optimized through a large number of cutting tests, and the optimal cutting parameters for cutting the structural member and the optimal cutting tool for the structural member are obtained.

As a further preferable scheme of the invention, the optimal cutting parameters of the structural member comprise cutting parameters of an inner arc surface of the large end of the structural member, cutting parameters of a lightening groove of a middle flange surface of the structural member and cutting parameters of an inner wall of the small end of the structural member; the cutting parameters of the inner arc surface of the large end of the structural part are as follows: vc is 78.5, N is 2500, F is 800, Ap is 0.25; the cutting parameters of the structural member intermediate flange surface lightening groove are as follows: vc is 78.5, N is 3250, F is 1250, Ap is 0.2; the cutting parameters of the inner wall of the small end of the structural part are as follows: vc is 78.5, N is 2500, F is 1500, Ap is 1.0.

As a further preferable scheme of the invention, the optimal cutting tool of the structural member comprises a cutting tool of an inner arc surface of a large end of the structural member, a cutting tool of a lightening groove of a middle flange surface of the structural member and a cutting tool of an inner wall of a small end of the structural member; the cutting tool of the arc surface at the inner side of the large end of the structural part is a 63mm cutter handle clamping 10mm milling cutter combined tool; the cutting tool of the structural member middle flange surface lightening groove is a hot-mounted lengthened damping tool; the cutting tool of the inner wall of the small end of the structural part is a T-shaped three-edge milling cutter with the diameter of 50 mmT.

As a further preferable embodiment of the present invention, the vibration aging treatment of step a4 is a spectral harmonic aging treatment.

As a further preferable scheme of the present invention, the special tool in step B1 is a low-stress clamping tool.

Compared with the prior art, the invention provides a precision machining method for a long-wheelbase variable-diameter complex thin-wall structural part, which has the following beneficial effects:

according to the method, the internal stress of the processed structural member is effectively reduced by optimizing the processing process flow and increasing the frequency spectrum harmonic aging treatment; by improving the cutting tool and optimizing the cutting parameters, the cutting precision is improved, the cutting time is shortened, and the cutting efficiency is improved.

Drawings

FIG. 1 is a schematic view of a process flow of the present invention;

FIG. 2 is a schematic view of a stress detection process according to the present invention;

FIG. 3 is a schematic flow chart of establishing a stiffness analysis model according to the present invention;

FIG. 4 is a schematic view of a structural member of the present invention;

FIG. 5 is a schematic view of the special tool of the present invention;

fig. 6 is a schematic view of the clamping of the structural member of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Referring to fig. 1-5, the invention provides a precision machining method for a long-wheelbase variable-diameter complex thin-wall structural member, which comprises the following steps:

s1, rough machining: the method comprises marking, rough turning, marking and rough milling;

by marking the surface of the structural part, a processing boundary line and a reference can be determined; the most of blank allowance can be removed by roughly turning and roughly milling the appearance of the structural member;

s2, stress detection processing: verifying the effect of aging treatment on the structural member by performing vibratory aging treatment on the internal stress and comparing;

through vibration aging treatment on the structural member, the internal stress of the workpiece can be eliminated, the structure and the size are stabilized, and the mechanical property is improved;

s3, establishing a rigidity analysis model: carrying out rigidity analysis on the structural member, and designing a special tool; establishing a rigidity analysis model according to the structural part and the special tool;

s4, mechanical processing simulation: performing mechanical processing simulation through a large number of cutting parameter samples to obtain optimal simulation parameters;

s5, finishing: the method comprises the steps of semi-finish turning, finish milling of the shape, finish turning of a standard, finish milling and punching, and tapping by a bench worker;

s6, structural part detection: detecting whether the processed structural part is qualified or not;

s6.1, when the structural member is detected to be unqualified, returning to the step S1 for processing again;

s6.2, when the structural member is detected to be qualified, finishing the processing.

As a further preferable embodiment of the present invention, the step S2 includes the following steps:

a1, residual stress detection: after the rough machining is finished, carrying out residual stress detection on the structural member;

a2, collecting physical parameters of the structural part: collecting physical parameters of the structural component;

a3, establishing a mechanical property model: establishing a mechanical property model through physical parameters of a structural part;

a4, vibration aging treatment: carrying out vibration aging treatment according to the mechanical property model;

a5, residual stress detection: carrying out residual stress detection on the structural member again;

a6, comparison with initial sample: comparing the sample detected in step A1 with the sample detected in step A5; when the stress effect of the vibration aging treatment is poor, returning to the step A4 to readjust the vibration parameters, and then performing the vibration aging treatment again; and when the stress effect of the vibration aging treatment is excellent, the next step is carried out.

By carrying out two times of residual stress detection at the same position, the effect of frequency spectrum harmonic aging on the structural member can be verified.

As a further preferable embodiment of the present invention, the step S3 includes the following steps:

b1, structural member rigidity analysis and special tool design: carrying out rigidity analysis on the structural member, and carrying out special tool design;

b2, establishing a rigidity analysis model: establishing a rigidity analysis model according to the structural part and the special tool;

b3, model analysis results: the stiffness analysis model is analyzed, and the results are viewed:

b3.1, when the analysis result is poor, returning to the step B1 again to adjust the tool parameters; or returning to the step B2 again to adjust the model parameters;

b3.2, when the analysis result is excellent, the next step is carried out.

As a further preferable embodiment of the present invention, the step S4 includes the following steps:

c1, carrying out a large number of cutting tests on the structural member to obtain a cutting parameter sample;

c2, performing machining simulation by cutting the parameter sample;

and C3, determining the optimal simulation parameters from the step C2.

As a further preferred embodiment of the present invention, in step S4, the machining process is optimized through a large number of cutting tests, and the optimal cutting parameters for cutting the structural member and the optimal cutting tool for the structural member are obtained.

Due to insufficient rigidity of the cutter, the violent impact when the cutter cuts into a workpiece induces cutter vibration, the vibration changes the thickness of chips, the cutting force changes, the vibration of a processing system is aggravated, the thickness of the chips is increased continuously, and cutting parameters and the cutting cutter are optimized according to the phenomenon; and (4) verifying through cutting comparison, and preferably selecting machining parameters and a machining tool.

As a further preferable aspect of the present invention, the optimal cutting parameters of the structural member include cutting parameters of an inner arc surface of a large end of the structural member, cutting parameters of a middle flange surface relief groove of the structural member, and cutting parameters of an inner wall of a small end of the structural member.

The cutting parameters of the inner arc surface of the large end of the structural part are as follows: vc is 78.5, N is 2500, F is 800, Ap is 0.25.

The cutting parameters of the structural member intermediate flange surface lightening groove are as follows: vc is 78.5, N is 3250, F is 1250, Ap is 0.2, and the processing precision of the surface is improved from ra6.3 to ra 1.6.

The cutting parameters of the inner wall of the small end of the structural part are as follows: vc is 78.5, N is 2500, F is 1500, Ap is 1.0.

As a further preferable aspect of the present invention, the optimal cutting tool for the structural member includes a cutting tool for an inner arc surface of a large end of the structural member, a cutting tool for a lightening groove of a middle flange surface of the structural member, and a cutting tool for an inner wall of a small end of the structural member.

The cutting tool of the arc surface at the inner side of the large end of the structural part is changed from a 20mm integral alloy milling cutter into a cutting tool with a 63mm cutter handle and a 10mm milling cutter combined tool; on the premise of ensuring the processing quality, the trial cutting processing vibration after the trial cutting is obviously improved, the cutting time is reduced from 3 hours to 1.8 hours, and the processing efficiency is improved by 40 percent.

The cutting tool of the lightening groove on the flange surface in the middle of the structural part is changed from a common lengthened tool to a hot-mounted lengthened damping tool; on the premise of ensuring the processing quality, the processing efficiency after the modification is shortened to 30min from the original 50min, and the processing efficiency is improved by 40%.

The cutting tool of the inner wall of the small end of the structural part is changed from an original inner milling head into a T-shaped three-edge milling cutter with the diameter of 50 mmT; on the premise of ensuring the processing quality, the processing time after the modification is shortened from 65min to 43min, and the processing efficiency is improved by 33.8%.

As a further preferable aspect of the present invention, the vibration aging treatment of step a4 is a frequency spectrum harmonic aging treatment; the method for carrying out full-automatic vibration treatment on the workpiece by utilizing the frequency spectrum analysis can completely replace three methods of natural aging, thermal aging and sub-resonance aging in the aspect of stress relief.

The frequency spectrum harmonic aging technology is used for carrying out frequency spectrum analysis on a metal workpiece by a Fourier analysis method to find dozens of harmonic frequencies of the workpiece, and then, five harmonic frequencies with the best effect are selected for processing, so that the purpose of multi-dimensionally eliminating residual stress is achieved, the dimensional accuracy and stability are improved, the deformation and cracking of the workpiece are prevented, and the workpiece is widely applied to casting, forging and welding of the metal workpiece in the mechanical manufacturing industry and residual stress and homogenization after processing.

As a further preferable scheme of the present invention, the special tool in step B1 is a low-stress clamping tool, and the low-stress clamping tool has the characteristics of high precision, general purpose, and rapid positioning.

High precision: the precision of the tool design corresponds to the precision of the pin hole of the structural part; the roundness of a positioning hole in the center of the tool is within 0.005, and the angular precision of the positioning pin is within 30'; the processing requirement of the angular precision 1' of the structural part is met.

General type: the tool base plate is suitable for processing and using two cylindrical structural members, and a positioning structure and a clamping device for the two structural members are designed on the tool base plate.

And (3) quick positioning: when the tool bottom plate is used, the center of the bottom plate is used as an axis, the positioning pin hole is used as an angular reference, rapid and efficient positioning is achieved, the average time is 5 minutes, and the positioning efficiency is improved by about 95%.

As a specific embodiment of the present invention:

referring to fig. 1-5, the structural member is rough machined: marking on the surface of the structural part, determining a processing boundary line and a reference, and then roughly turning the appearance of the structural part to remove most blank allowance; marking the line again after the rough turning is finished, then roughly turning the outline of the structural component, and carrying out the next step after the rough machining is finished.

And (3) stress detection treatment: firstly, carrying out residual stress detection on the structural member, and recording; then, collecting physical parameters of the structural part, and establishing a mechanical property model according to the physical parameters of the structural part; after the mechanical property model is established, carrying out internal stress on the frequency spectrum harmonic aging treatment structural part, and then carrying out residual stress detection again; comparing the data samples of the two stress detections to observe the internal stress condition of the structural part after the frequency spectrum harmonic ageing treatment; when the internal stress treatment effect of the structural member is not ideal, returning to the step of frequency spectrum harmonic aging treatment, adjusting parameters, performing repeated aging treatment again after the parameters are adjusted, detecting and observing the internal stress condition of the structural member, and repeating the step to obtain appropriate aging treatment parameters until the internal stress treatment effect of the structural member is good; and when the internal stress treatment effect of the structural part is excellent, carrying out the next step.

Establishing a mechanical model: carrying out rigidity analysis on the structural member, and designing a special tool; establishing a rigidity analysis model according to the structural part and the special tool, and checking a model analysis result; when the analysis result is poor, returning to the previous step to adjust the parameters of the rigidity analysis model, or returning to the special tool design step to adjust the parameters of the special tool, performing model analysis again, and checking the model analysis result until a good analysis result is obtained; when the analysis result is excellent, the next step is performed.

And (3) mechanical processing simulation: performing a large number of cutting tests on the structural member to obtain a cutting parameter sample, and performing machining simulation on the cutting parameter sample to determine an optimal simulation parameter; the optimal cutting parameters and the optimal cutting tool can be obtained through a cutting test, so that the cutting time can be effectively shortened, and the processing efficiency is improved; after obtaining the optimal simulation parameters, performing finish machining; clamping the structural part by using a special tool, then carrying out semi-finish turning, finish milling of the appearance, finish turning of a benchmark, finish milling of a hole and tapping by a bench worker, and after the steps are completed, detecting whether the structural part is qualified; when the structural member is unqualified during detection, returning to the previous step for processing again; and when the structural member is detected to be qualified, finishing the processing.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.