CN110103079B - Online monitoring method for tool wear in micro-milling process - Google Patents

Online monitoring method for tool wear in micro-milling process Download PDF

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CN110103079B
CN110103079B CN201910523349.6A CN201910523349A CN110103079B CN 110103079 B CN110103079 B CN 110103079B CN 201910523349 A CN201910523349 A CN 201910523349A CN 110103079 B CN110103079 B CN 110103079B
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朱锟鹏
李斯
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Hefei Institutes of Physical Science of CAS
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q17/00—Arrangements for observing, indicating or measuring on machine tools
    • B23Q17/09—Arrangements for observing, indicating or measuring on machine tools for indicating or measuring cutting pressure or for determining cutting-tool condition, e.g. cutting ability, load on tool
    • B23Q17/0952—Arrangements for observing, indicating or measuring on machine tools for indicating or measuring cutting pressure or for determining cutting-tool condition, e.g. cutting ability, load on tool during machining
    • B23Q17/0957—Detection of tool breakage

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Abstract

The invention discloses an online monitoring method for cutter abrasion in a micro-milling process, which comprises the following steps: 1, establishing a micro-milling force model containing cutter abrasion, calibrating an abrasion coefficient in the model according to the micro-milling force measured in each milling experiment, and simultaneously recording the corresponding abrasion area of the milling cutter; 2, fitting a relational expression of the wear coefficient and the wear area of the milling cutter by adopting a numerical method according to a series of discrete data points of the wear coefficient and the wear area of the milling cutter obtained by experiments; and 3, obtaining a direct mapping relation between the micro-milling force and the wear area of the cutter according to the relation between the micro-milling force, the wear coefficient and the wear area so as to realize the on-line monitoring of the cutter wear in the micro-milling process. The invention can utilize the on-line monitoring method/technology to predict the cutter abrasion and avoid the cutter failure, thereby improving the processing efficiency and the processing quality.

Description

Online monitoring method for tool wear in micro-milling process
Technical Field
The invention relates to the field of micro-milling, in particular to an online monitoring method for cutter abrasion in a micro-milling process.
Background
With the adjustment of industrial structures in China, numerically-controlled machine tools are developing towards high precision, high speed, high efficiency, flexibility and intellectualization. In the high-end precision manufacturing field, for example, the processing of many key parts in modern national defense equipment, the processing of aeroengine blades, speed reducers, crankshaft parts and the like, because the structure is complex, the material processability is poor, the precision requirement is high, when the parts are processed by adopting the traditional numerical control machine, the geometric precision and the surface integrity are poor, and the quality is difficult to ensure.
The micro milling has the advantages of diversity of processing materials and capability of realizing complex three-dimensional curved surface processing, and has wide application prospect in the fields of processing of micro and ultra-precise instruments and the like. However, when the micro milling cutter performs discontinuous cutting at an ultrahigh rotating speed, the grinding damage of the cutter is rapid and difficult to monitor, the machining precision and the product quality are seriously affected, and the online monitoring of the grinding damage of the cutter is always a difficult point for controlling the micro milling process.
In the aspect of tool wear detection technology, researchers use the wear amount of a front tool face or a rear tool face to represent the wear degree of a cutting edge, and on the basis of the wear degree, a micro-milling force model considering tool wear is established, the wear degree of the tool is judged in advance, and the residual service life of the tool is predicted. However, in the actual production process, some problems still need to be solved:
firstly, the abrasion state of the cutter is difficult to measure in real time due to the high-speed rotation of the main shaft of the precision machine tool and the small diameter of the micro milling cutter; secondly, the existing micro-milling force model lacks a direct mapping relation between the milling force and the tool wear amount, and the tool wear degree cannot be judged by monitoring the micro-milling force in real time.
Disclosure of Invention
The invention provides an on-line monitoring method for cutter abrasion in the micro-milling process to overcome the defects of the prior art, so that the cutter abrasion can be predicted by using the on-line monitoring method/technology, the cutter failure can be avoided, and the machining efficiency and the machining quality can be improved.
In order to achieve the purpose, the invention provides the following technical scheme:
the invention discloses an online monitoring method for cutter abrasion in a micro-milling process, which is characterized by comprising the following steps:
step 1, establishing a micro-milling force model containing cutter abrasion, calibrating an abrasion coefficient in the model according to the micro-milling force measured in each milling experiment, and simultaneously recording the corresponding abrasion area of the milling cutter;
step 2, fitting a relational expression of the wear coefficient and the wear area of the milling cutter by adopting a numerical method according to a series of discrete data points of the wear coefficient and the wear area of the milling cutter obtained by experiments;
and 3, obtaining a direct mapping relation between the micro milling force and the wear area of the cutter according to the relation between the micro milling force, the wear coefficient and the wear area so as to realize the on-line monitoring of the cutter wear in the micro milling process.
The method for monitoring the cutter abrasion on line in the micro-milling process is also characterized in that a micro-milling force model F containing the cutter abrasion in the step 1 is established by using a formula (1):
F＝KwFC(1)
in the formula (1), KwTo the coefficient of wear, FCA micro-milling force model without considering tool wear.
The micro-milling force model without considering tool wear is a milling force calculation model established according to micro-milling mechanical characteristics.
The wear area of the milling cutter in the step 1 is obtained by measuring the wear area on the end surface when the cutter is turned upside down after one process is finished.
Any one discrete data point in the step 2 consists of a calibrated wear coefficient and a measured tool wear area after the micro-milling force of each process is measured.
In the step 2, a relational expression of the wear coefficient and the wear area of the milling cutter is fitted by using the expression (2):
Sw＝f(Kw) (2)
in the formula (2), SwF (-) represents a function of the mapping relationship for the milling cutter wear area.
In the step 3, a direct mapping relation between the micro milling force and the wear area is obtained by using the formula (3):
F＝g(Sw) (3)
in the formula (3), g (-) represents a function of the mapping relationship.
Compared with the prior art, the invention has the beneficial effects that:
1. the method can evaluate the wear state of the cutter and predict the residual life of the cutter by monitoring the micro-milling force on line, thereby providing a feasible theoretical method for ensuring the processing quality.
2. The tool wear amount is defined according to the wear area on the end plane of the micro milling cutter, and compared with the traditional method of representing the wear amount by adopting the wear length on the back cutter surface or the front cutter surface, the tool wear amount can be comprehensively represented by adopting the wear area.
3. The method can obtain the direct mapping relation between the micro-milling force and the tool abrasion loss, not only provides a feasible technical support for monitoring the tool abrasion state on line, but also lays a scientific theoretical basis for analyzing the tool abrasion mechanism, prolonging the service life of the tool, optimizing milling parameters and improving the processing efficiency.
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FIG. 1 is a schematic view of the micro-milling cutter wear of the present invention;
FIG. 2 is a schematic diagram of the present invention for establishing a micro-milling force to tool wear area mapping relationship;
FIG. 3 is a flow chart of the on-line monitoring method of the present invention.
Detailed Description
In the embodiment, the method for monitoring the cutter abrasion in the micro-milling process on line is a method combining theory and experiment, and the quantitative relation between the micro-milling force and the cutter abrasion in the micro-milling process is determined. Firstly, establishing a micro-milling force model containing a wear coefficient; secondly, obtaining the wear area of the micro milling cutter and the mapping relation between the micro milling force and the wear coefficient through experiments; finally, the direct mapping relation of the micro milling force and the tool wear area is obtained according to the relation of the micro milling force, the wear coefficient and the wear area, so that the defect that the tool wear cannot be evaluated on line according to a milling force dynamic signal when the tool wear is predicted in the prior art is overcome, the defect of accumulated errors caused by repeated installation and tool unloading when the tool wear is measured is avoided, the defects that the tool fails to be predicted and the machining quality is reduced are overcome. Specifically, as shown in fig. 3, the method includes the steps of:
(1) establishing a micro-milling force model containing cutter abrasion, calibrating an abrasion coefficient in the model according to the micro-milling force measured in each milling experiment, and simultaneously recording the corresponding abrasion area of the milling cutter, wherein the method comprises the following steps:
1) according to the characteristics of micro-milling, establishing a micro-milling force model containing cutter wear factors:
I) according to the micro-milling theory, establishing a milling force model F containing undetermined parameters by using the formula (1)C：
FC＝(Ft,Fr)＝f(h,K(Kmt,Kmr,Ket,Ker)) (1)
In the formula (1), Ft、FrRespectively tangential cutting force and radial cutting force; h is the instantaneous cutting thickness; kmt、KmrRespectively the tangential and radial cutting coefficients; ket、KerRespectively tangential and radial cutting edge coefficients.
a) During micro-milling, the size effect caused by the sharp reduction of the blunt radius of the cutting edge will cause the effective rake angle to change into a negative rake angle and a minimum cutting thickness. In the milling force model, the parameters representing the micro milling size effect are the cutting thickness h:
Figure BDA0002097395660000031
in the formula (2), D is the diameter of the milling cutter, N is the number of teeth,
Figure BDA0002097395660000032
Is the tooth space angle, β is the helix angle, reIs the radius of the blunt circle of the cutting edge hminTo a minimum cutting thickness, apIs the cutting depth, b is the cutting width, ftFeeding is performed for each tooth, and n is the rotating speed of the main shaft.
b) In the cutting process, when the instantaneous cutting thickness h is less than the minimum cutting thickness, the cutting process does not generate cutting, and at the interface formed by the blade and the material, the rubbing and plowing action occurs intermittently instead of the cutting process. Therefore, the cutting and plowing phenomena need to be considered separately when building the milling force model:
Figure BDA0002097395660000033
it is noted that in establishing the micro-milling force model, different micro-milling force models may be established by taking into account different micro-milling characteristics or parameters. The formula (4) is a cut thickness model:
Figure BDA0002097395660000041
in the formula (4), θ represents a cutting angle of the cutter teeth.
And (3) substituting the formula (4) for the formula (5) to obtain the micro-milling force analysis model. The actual measured milling forces are usually expressed in a rectangular coordinate system (F)x,Fy) Therefore, the milling force needs to be converted by equation (5):
Figure BDA0002097395660000042
besides the related micro-milling characteristics or parameters listed in the embodiment, the micro-milling force model can be established by considering tool bounce, tool nose track and the like, and other modeling modes can be found in the literature; for example:
1. jumboc, Lekoc, Meitao, Shiyunjao micro milling force modeling research progress 2016,52(17):20-34.http:// www.cjmenet.com.cn/Jwk _ jxgcxb/CN/10.3901/JME.2016.17.020;
2.B.Boswell,M.N.Islam,I.J.Davies.International JournalofAdvancedManufacturing Technology,2018,94(1-4):789-806.https://doi.org/10.1007/s00170-017-0912-y；
3.D.Carou,E.M.Rubio,J.Herrera,C.H.Lauro,J.P.Davim.Latest advancesinthemicro-milling oftitanium alloys:areview.ProcediaManufacturing,2017,13:275-282.https://doi.org/10.1016/j.promfg.2017.09.071。
II) in the cutting process, the cutter abrasion can obviously influence the cutting process, and the milling force acting on the front and back tool surfaces is increased along with the increase of the cutter abrasion, so the influence of the cutter abrasion needs to be considered when a milling force model is established. Because wear is present across the entire edge, it is often plausible to use a "dimension" on a scale (e.g., using rake or flank wear, fig. 1) alone to represent the extent of wear of the edge. Therefore, the wear area on the edge is defined herein as the amount of tool wear and the wear coefficient K is usedwTo reflect the degree of influence of tool wear on the milling force:
F＝KwFC(6)
it should be noted here that the tool wear is a spatial concept, and for the convenience of characterization, the tool wear area projected onto the end plane of the micro-milling cutter is used to represent the tool wear, as shown in fig. 1. In addition, taking the schematic diagram of the two-tooth micro milling cutter in fig. 1 as an example (the milling cutter may be a single tooth, 3 teeth, or other teeth), the wear area on each tooth of the milling cutter is separately measured/calculated, and then the average wear area of the two teeth is defined as the wear amount of the milling cutter.
2) And calibrating parameters in the micro-milling force model according to the micro-milling force data obtained by the experiment, and simultaneously recording the cutter abrasion area corresponding to each procedure.
(2) Fitting a relation between the wear coefficient and the wear area of the milling cutter by a numerical method according to a series of discrete data points of the wear coefficient and the wear area of the milling cutter obtained by experiments, and comprising the following steps of:
1) data points for wear coefficient versus wear area are plotted.
2) Selecting a proper model according to the data distribution rule to fit a relation between the wear coefficient and the wear area:
Sw＝f(Kw) (7)
in the formula (7), SwF (-) represents a function of the mapping relationship for the milling cutter wear area.
It should be noted here that fitting the functional relation to the data can take many forms. Assume the data point is (K)w1,Sw1),(Kw2,Sw2),…(Kwi,Swi) E.g. by fitting an exponential function, then Sw＝aexp(bKw+ c), wherein a, b, c are coefficients to be fitted; if a polynomial function fitting is adopted, taking a cubic polynomial as an example, then
Figure BDA0002097395660000051
Wherein a, b, c and d are coefficients to be fitted. And the actual condition is selected according to the data distribution rule, and the fitting effect is optimal when various function rules are met.
(3) According to the relationship among the micro-milling force, the wear coefficient and the wear area, obtaining a direct mapping relationship between the micro-milling force and the wear area of the cutter, so as to realize the online monitoring of the cutter wear in the micro-milling process, as shown in fig. 2, the method comprises the following steps:
1) relationship between micro-milling force and wear coefficient:
F＝u(Kw) (8)
in the formula (8), u (-) is a mapping relation function of the micro milling force and the wear coefficient.
2) In combination with equations (7) and (8), a direct mapping of the micro-milling force and the tool wear area can be determined using equation (9):
F＝g(Sw) (9)
it is noted that the micro-milling force is a periodically varying value related to the position of the milling cutter, while the measured wear area of the tool is a determined value. In order to enable the two methods to directly correspond to each other, a statistical value (root mean square value RMS) of the micro-milling force in 10 cycles before the last second in each machining process (time and cycle are not selected uniquely and can be selected in a time period before the milling cutter exits from a workpiece, and other cycle numbers such as 12 cycles, 15 cycles and the like can be selected in the milling cycle) is used as an indication value of the micro-milling force (the statistical value is the root mean square value, variance, mean value, skewness coefficient, warping coefficient and the like in a time domain, even is a corresponding statistical value in a frequency domain, one or more groups with obvious characteristics can be selected to represent the micro-milling force), and the mapping relation between the micro-milling force and the tool wear area is represented in formulas (8) and (9).
The method can determine the quantitative relation between the micro milling force and the cutter abrasion loss, overcomes the defect that the cutter abrasion cannot be estimated on line according to a milling force dynamic signal when the cutter abrasion is predicted in the prior art, avoids the defect of accumulated error caused by repeated installation and unloading of the cutter when the cutter abrasion is measured, overcomes the defects of cutter failure and reduced processing quality caused by the fact that the cutter abrasion cannot be predicted, and provides a feasible theoretical method for estimating the cutter abrasion state and predicting the residual service life of the cutter by monitoring the micro milling force on line so as to ensure the processing quality.

Claims (1)

1. An on-line monitoring method for tool wear in a micro-milling process is characterized by comprising the following steps:
step 1, establishing a micro-milling force model F containing cutter abrasion by using the formula (1), calibrating an abrasion coefficient in the model according to the micro-milling force measured in each milling experiment, and simultaneously recording the corresponding abrasion area of the milling cutter; the wear area of the milling cutter is obtained by measuring the wear area on the end part plane when the cutter is turned upside down after each procedure is finished;
F＝KwFC(1)
in the formula (1), KwTo the coefficient of wear, FCThe method comprises the following steps of (1) establishing a micro-milling force model without considering tool wear according to micro-milling mechanical characteristics;
step 2, obtaining a series of discrete data points of the wear coefficient and the wear area of the milling cutter according to experiments, wherein any one discrete data point consists of the wear coefficient calibrated after the micro-milling force of each process is measured and the measured wear area of the cutter;
fitting a relational expression of the wear coefficient and the wear area of the milling cutter by adopting a numerical method shown in the formula (2);
Sw＝f(Kw) (2)
in the formula (2), SwF (-) represents a function of the mapping relation for the wear area of the milling cutter;
step 3, obtaining a direct mapping relation between the micro-milling force and the wear area of the cutter by using the formula (3) according to the relation between the micro-milling force, the wear coefficient and the wear area so as to realize the online monitoring of the cutter wear in the micro-milling process;
F＝g(Sw) (3)
in the formula (3), g (-) represents a function of the mapping relationship.
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CN110842648A (en) * 2019-11-28 2020-02-28 南京科技职业学院 Online cutter wear prediction and monitoring method
CN111007800B (en) * 2019-12-20 2020-10-30 常州先进制造技术研究所 Universal method for wear prediction and machining parameter optimization of flat-head micro-milling cutter
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Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4918427A (en) * 1989-03-27 1990-04-17 General Electric Company Multi-level tool break detection using multi-mode sensing
DE102008015004A1 (en) * 2008-03-19 2009-09-24 Mtu Aero Engines Gmbh Method of displaying changes to a drilling tool
CN106002487B (en) * 2016-07-30 2018-03-09 湖北知本信息科技有限公司 A kind of wear of diamond cutter monitoring method based on cutting Force Model
CN108356606B (en) * 2018-03-19 2020-05-01 西北工业大学 Tool wear online monitoring method based on wavelet packet analysis and RBF neural network
CN109746765A (en) * 2018-11-01 2019-05-14 北京理工大学 A kind of tool failure state monitoring method based on accumulation and control theory
CN109605127A (en) * 2019-01-21 2019-04-12 南京航空航天大学 A kind of cutting-tool wear state recognition methods and system

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