CN103761386A - High-speed milling cutter designing method for suppressing unevenness in forced vibration wear of cutter teeth - Google Patents

Abstract

The invention discloses a high-speed milling cutter designing method for suppressing unevenness in forced vibration wear of cutter teeth, and belongs to the technical field of cutters. The high-speed milling cutter designing method particularly includes providing a process for identifying forced vibration wear behavior of a milling cutter by the aid of correlation characteristics of forced vibration of the high-speed face milling cutter and wear behavior of the cutter teeth; building a multi-tooth forced vibration wear model of the milling cutter and providing a process for predicting and judging forced vibration wear and uneven wear of the milling cutter. The high-speed milling cutter designing method has the advantages that a process for controlling the uneven wear of the milling cutter and a process for designing the milling cutter are provided, so that the problem of design conflicts among multi-tooth wear positions, wear areas and wear depth control variables of an existing milling cutter can be solved, the milling cutter with the diameter of 63mm can be designed by the high-speed milling cutter designing method, the unevenness in forced vibration wear of the cutter teeth for cutting No.45 steel at high speeds can be effectively suppressed, and the high-speed milling cutter designing method is used for designing milling cutters.

Description

A kind of high-speed milling cutter method for designing that suppresses cutter tooth forced vibration wearing and tearing unevenness

Technical field

The present invention proposes a kind of high-speed milling cutter method for designing that suppresses cutter tooth forced vibration wearing and tearing unevenness, specifically utilizes the associate feature of High-speed Face Milling Cutter forced vibration and cutter tooth abrasional behavior, provides the recognition methods of milling cutter forced vibration abrasional behavior; Set up the multiple tooth forced vibration wear model of milling cutter, propose the forecast and judge side of milling cutter forced vibration wearing and tearing and uneven wear; Control method and the design method for milling cutter of milling cutter uneven wear are proposed, solve the design conflicts problem of the multiple tooth abration position of milling cutter, wear area, wearing depth control variable, design the diameter 63mmm milling cutter that can effectively suppress No. 45 steel knife tooth forced vibrations of high-speed cutting wearing and tearing unevenness.

Background technology

In milling cutter working angles, tool wear is one of key factor affecting working angles.In actual processing, tool wear is violent, vibration cutting is obvious, machined surface is of low quality, tool failure is serious, cutter service efficiency and under serviceable life degradation problem commonplace.This has seriously increased the uncertainty that milling cutter lost efficacy, and has restricted security and the application of high-efficient milling in important spare part processing and other fields of milling cutter.

Different from common milling, the cutting parameter that high-efficient milling adopts is generally larger, and that the consequence of bringing is thus tool wear is rapid, even easily occurs micro-tipping, damaged situation.Raising to workman's safety and working (machining) efficiency all has a significant impact.Milling cutter security simultaneously declines and also can cause tooling system to produce distortion, causes the variation of chip-load, and crudy, cutter life and machine tool accuracy are had a direct impact.

Affected by workpiece hardness, improve stock-removing efficiency and very easily cause that the shock and vibration in working angles increases, and causes cutter wear aggravation.In high-speed machining process, tool wear behavior is the result of multifactor functioning.With this understanding, carry out large-scale curved high speed, high-efficient cutting processing, its consequence is milling cutter extended active duty, and safe reliability declines rapidly, not only cannot guarantee machining precision and machined surface quality, and directly cause milling cutter to lose efficacy, cause multiple safety issue, there are some researches show, follow high speed, fierceness to rub and the tool wear of generation, its form and to form mechanism not only relevant to friction pair chemistry, physics, mechanical property, and the friction pair variation causing with vibration is closely related.

After " CXK5463 water chamber head dedicated numerical control movable gantry milling-lathe machining center " carried out to detailed investigation, the rubbing wear meeting of finding cutter causes the surface that processes undesirable to a great extent, especially the vibration that milling cutter produces in working angles can have a strong impact on the surface processing, even chatter mark is obvious, do not reach processing request at all, or cause the great number of issues such as precise decreasing in lathe use procedure, and on-the-spot tool wear is violent, stop cutter tool changing situation outstanding, even when abrasion condition is not very serious, just there is the situations such as tipping in some cutters.Seriously delay the process-cycle, restricted service efficiency and the serviceable life of milling cutter.

At present, the research of domestic relevant cutter rubbing wear mainly concentrates on material, and cutting data etc. are above factor.And the present invention considers that face milling cutters are when cutting metal material, owing to being subject to the impact of cutting force and centrifugal force, produce forced vibration; First by experiment analyze two kinds of impact mechanism of milling cutter vibration behavior on cutter wear behavior and the inhomogeneous behavior of cutter wear, from controlling vibration behavior, start with, wear problem and cutter wear non-uniformity problem for single cutter tooth are effectively controlled, rather than take and reduce cutting data, reduce stock-removing efficiency and extend cutter life as cost.

Study at present the rubbing wear problem of cutter, most of researchists just study from cutting experiment method and limited element analysis technique, and very few for the wearing and tearing under effect of vibration and the research of wearing and tearing unevenness.Do not consider the impact of stress, vibration Cutter wear.Therefore, from the angle of vibration, leave for the wear problem of research milling cutter, controlling cutter wear, to improve working (machining) efficiency, extend milling cutter serviceable life be very significant.

Summary of the invention

The present invention is directed to the wearing and tearing of face milling cutters cutter tooth is solution target with face milling cutters overall wear unevenness, and a kind of high-speed milling cutter method for designing that suppresses cutter tooth forced vibration wearing and tearing unevenness is provided.

The present invention in order to solve the problems of the technologies described above taked technical scheme is:

A kind of high-speed milling cutter method for designing that suppresses cutter tooth forced vibration wearing and tearing unevenness of the present invention:

Step 1, according to the test result of milling cutter forced vibration wear test, milling cutter forced vibration behavior and cutter wear behavior are carried out to association analysis, obtained the associate feature of milling cutter forced vibration behavior and cutter wear behavior; Tool wear behavior while having analyzed facing cut Tool in Milling metal material; The cutting characteristic of milling tool processing different materials below contrast different parameters, the impact of opposite milling cutter wearing and tearing; The recognition methods of milling cutter forced vibration wearing and tearing has been proposed;

Step 2, theoretical according to vibration, has analyzed the vibration behavior of milling cutter in milling process, and has carried out parametrization sign; The feature of several main wearing and tearing forms while having analyzed face milling cutters milling metal material, and the morphogenetic position of respectively wearing and tearing, and the wearing and tearing form of face milling cutters is carried out to parametrization sign; Three kinds of milling cutter forced vibration behaviors have been illustrated machine-processed on the impact of milling cutter monodentate abrasional behavior; Analyze the impact of forced vibration behavior on cutter wear behavior; Wearing and tearing based in face milling cutters cutting process, damaged theoretical, analyze the impact on cutter wear such as cutting speed, vibration cutting and cutting force in working angles, disclose the impact mechanism of three kinds of milling cutter forced vibrations on cutter wear unevenness; Set up the multiple tooth forced vibration wear model of milling cutter, propose forecast and the evaluation method of milling cutter forced vibration wearing and tearing and uneven wear, differentiate friction pair character, classification;

Step 3, machine-processed according to above-mentioned six kinds of impacts, different mechanism control methods is different, the control method that has proposed milling cutter forced vibration wearing and tearing unevenness, discloses the impact of milling cutter forced vibration behavior on cutter wear behavior, realizes the effective control to face milling cutters forced vibration wearing and tearing;

Step 4, according to milling cutter model analysis and vibration abrasion experimental result, the accuracy of checking milling cutter control method, solve the collision of variables problem in control method, solve control loop, adopt this control method, by the design of cutter parameters, cutting parameter, the method for designing of milling cutter is proposed, adopt the mode of testing to verify feasibility, the accuracy of method for designing.

Preferred: the recognition methods of milling cutter forced vibration wearing and tearing

The forced vibration meeting of milling cutter causes milling cutter tooth to produce forced vibration wearing and tearing, comprises that milling cutter forced vibration is on milling cutter tooth abrasive nature (being rake wear or wear of the tool flank or cutting edge wearing and tearing), the abration position p(depth capacity position of wearing and tearing), the impact of the degree of wear (width b and wearing depth h wear and tear).Milling cutter forced vibration causes the behavior of a plurality of cutter tooth generation of milling cutter uneven wear, comprises that three kinds of milling cutter uneven wears form mechanism: each odontotripsis different in kind of milling cutter, abration position is inhomogeneous, the degree of wear is inhomogeneous.

For specifically studying intuitively and characterize the forced vibration wearing and tearing of milling cutter, the mode that adopts experiment herein to milling cutter the wearing and tearing under process system forced vibration measure.It is Dalian VDL-1000E lathe that experimental facilities adopts, to tooth pitch F2033.022.040.063 milling cutters such as 63mm diameter 4 teeth, in the workpiece process of No. 45 Steel materials of cutting, vibration cutting adopts eastern magnificent examining system and PCB vibration acceleration sensor to measure, and the testing tool of tool wear is the super depth-of-field microscope of KEYENCE-VHX600 type.For understanding the mutual relationship between forced vibration and tool wear, utilize gray system theory modeling software, Milling Parameters is: milling cutter feed engagement f _z=0.08～0.15mm/z, cutting linear velocity v _c=435～614m/min, cutting-in a _p=0.3～0.5mm, carries out grey correlation analysis to the vibration cutting under above parameter and wearing and tearing.Wearing and tearing width unevenness and the milling cutter Oscillation Amplitude of forward and backward cutter are in close relations, forward and backward knife face wearing depth unevenness and milling cutter vibration frequency are in close relations, this is because cutter and Workpiece vibration all present periodically, when the rotation cutting frequency of milling cutter vibration frequency and milling cutter tooth is different, the amplitude of each cutter tooth of milling cutter milling cutter when cutting is all different, and the forced vibration wearing and tearing that cause milling cutter are uneven wear.

Utilize the associate feature of face milling cutters forced vibration and cutter tooth wearing and tearing and wearing and tearing unevenness, form the physical relationship mapping of milling cutter forced vibration behavior to cutter wear behavior, can identify the behavioral parameters of milling cutter forced vibration behavioral parameters, cutter wear behavioral parameters, milling cutter uneven wear; Milling cutter forced vibration behavior affects relation to three of milling cutter tooth abrasional behavior kinds; Milling cutter forced vibration behavior affects relation to three kinds of the behavior of milling cutter uneven wear; The forced vibration control variable of milling cutter monodentate abrasional behavior and the behavior of milling cutter uneven wear.Obtain the physical relationship mapping of milling cutter forced vibration behavior to abrasional behavior, can, by the observation to vibration behavior, realize the identification of opposite cutter wear behavior in milling process.

Preferred: the multiple tooth forced vibration abrasion forecasting method of milling cutter

The description of complete high-speed milling vibration signal, characterizes respectively from three directions of dynamic behavior: the behavior of line-spacing directional dynamics; Direction of feed dynamic behavior; Axial direction dynamic behavior.Comprise three direction main frequency of vibration sizes and amplitude corresponding to main frequency of vibration.

The whole forced vibration meeting of milling cutter changes milling cutter position of tool tip and changes, contact relation, the actual cut angle of cutter, the parameter of cutting layer of cutter tooth and workpiece have been changed simultaneously, for the impact of research milling cutter forced vibration and cutter tooth position relationship tool setting odontotripsis, take the round heart of cutter tooth center pit as true origin, direction of feed as X-axis, line-spacing direction sets up Descartes's rectangular coordinate system as Y-axis, major axes orientation as Z axis.Milling cutter at a time cutter tooth i participates in cutting, and now milling cutter vibration displacement is S _vibration, be equivalent to milling cutter and be rocked to dotted line position, cutter tooth i this constantly position of tool tip by J _ito J ' _i.If cutter hub threaded hole radius is r spiral shell, point width cutter hub threaded hole distance of center circle is from being l _blade, the mismachining tolerance of blade i is Δ 1 _i, the rigging error of blade on this cutter is Δ 2 _i, position of tool tip J before vibrating _icoordinate is:

If milling cutter vibration displacement is S, vibration is θ with X-axis angle _ix, with Y-axis angle be θ _iy, with Z axis angle be θ _iz, milling cutter is position of tool tip J ' after vibration _icoordinate is:

Set up cutter and workpiece contact geometry model herein, analyze the actual cut length of Tool in Cutting sword and the relation between the area of cut, in Milling Process, the actual cut length of cutter blade is main cutting edge (line segment OA) and front cutting edge (line segment EB) and line segment OE sum, it is not only relevant with tool cutting edge angle and auxiliary angle, goes back and cutting parameter (feed engagement f _zwith cutting depth a _p) relevant.

K _rfor tool cutting edge angle, k ' _rfor auxiliary angle, work as f _z>a _p(cotk _r+ cotk ' _r) time, the actual cut length of blade and the amount of feeding are irrelevant, generally, and f _z<a _p(cotk _r+ cotk ' _r), at this, we only analyze a kind of situation below, by geometric analysis, are easy to obtain the main cutting edge length l that participates in cutting _oAwith front cutting edge length l _oBexpression formula:

$\left\{\begin{array}{c}{l}_{\mathrm{OA}}=\frac{a_p}{\sin k_r}\\ l_{\mathrm{OB}}=\frac{f_z}{(\cot k_r+\cot k_r^{\&prime;})\sin k_r^{\&prime;}}\end{array}\right.---\left(4\right)$

Take point of a knife as initial point, and direction of feed is X-axis, and line-spacing direction is Y-axis, and major axes orientation is that Z axis is set up cartesian coordinate system, sets up milling cutter cutting vibration and tool cutting edge angle correlation model.The displacement that milling cutter tooth produces by vibrating is S _vibration, being equivalent to cutter tooth and swinging θ angle from initial position, tool cutting edge angle is by k _rbecome k _r1, θ _s1for S _vibrationin YOZ plane with the angle of Y-axis,, by trigonometric function relation, can be obtained:

k _r1=k _r+2θ _S1 (5)

In like manner, milling cutter anterior angle γ ₀, relief angle α ₀in XOZ plane, cutter tooth swings θ from initial position ₁angle, anterior angle is by γ ₀become γ ₀₁, relief angle is by α ₀become α ₀₁, cutting edge inclination is by λ _sbecome λ _s1, θ _s2for S _vibrationin YOZ plane with the angle of X-axis, θ _s3for S _vibrationin XOY plane, with the angle of Y-axis, by trigonometric function relation, can be obtained:

$\left\{\begin{array}{c}{\mathrm{\&gamma;}}_{01}={\mathrm{\&gamma;}}_0+{2\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">S</figure-callout>}2}\\ {\mathrm{\&alpha;}}_{01}={\mathrm{\&alpha;}}_0-{2\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">S</figure-callout>}2}\\ {\mathrm{\&lambda;}}_{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">s</figure-callout>}1}={\mathrm{\&lambda;}}_s+{2\mathrm{\&theta;}}_{S3}\end{array}\right.---\left(6\right)$

Face milling cutters when milling, cutting parameter and parameter of cutting layer: feed-speed is V _f(m/min), f _zifor arbitrary neighborhood two between cog feed engagements (mm/z), there is phasing degree in milling cutter

(i is that cutter tooth code name is from 1 to Z).

Because milling cutter cutter workpiece in milling process all exists vibration, through cutting time t, when milling cutter is f in this moment vibration frequency _itime, after milling cutter, knife face and the work piece contact point vibration abrasion degree of depth are h _after, the amplitude of cutter and workpiece is respectively A _cutter, A _workpiece:

Tool wear position is to take position of tool tip as initial point, along main cutting edge direction, is X-axis, and rake face normal direction is Z axis in the other direction, sets up rectangular coordinate system, and making P point coordinate is (x _p, y _p, z _p), therefore, P point is apart from point width from being:

$l_P=\sqrt{x_{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">p</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="y\; p"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">y</figure-callout>}}_p^{}+z_p^2}---\left(9\right)$

The position of tool wear is different, represents that the abrasive nature of cutter is different, when P point is positioned at rake face and has a segment distance apart from cutting edge, is crescent hollow abrasion, while being positioned at rear knife face, is wear of the tool flank, if occur on cutting edge, is micro-tipping.

Milling cutter vibrometer reveals the vibration characteristics being combined by low-frequency vibration and dither, this vibration characteristics of milling cutter makes to produce little amplitude to-and-fro movement between itself and work piece close contact surface, and in single cutter tooth working angles, contact interface does not have the chance exposing, and abrasive particle is difficult to the friction surface of escaping out.Therefore, in single cutter tooth working angles, between milling cutter and work piece surface in contact, not only there is unidirectional sliding frictional wear, and have the vibration abrasion under adhesive wear and the effect of abrasive wear mixing mechanism.Milling cutter vibration and vibration abrasion model thereof in cutter tooth working angles.

Through cutting time t, when milling cutter is f in i moment vibration frequency _itime, after milling cutter, after knife face and work piece contact point vibration abrasion change in depth Δ h, before rake wear wide variety Δ b, before rake wear change in depth Δ h, cutting-in is from a _pbecome a ' _p, feed engagement is by f _zbecome f ' _z, the vibration displacement of cutter and workpiece is respectively vector S cutter, S workpiece, and this moment milling cutter forced vibration behavioral parameters and milling cutter monodentate abrasional behavior parameters relationship are:

When larger cutting force produces strong forced vibration, while making a plurality of frequency multiplication of milling cutter generation of vibration, the cutter wear degree of depth will increase exponentially.With this understanding, cutter wear amount constantly increased with the cutting time, and the wearing and tearing of vibrating from milling cutter will make milling cutter and work piece contact interface under completely reserved stress effect, cause larger vibration abrasion.Milling cutter vibration frequency f _idetermined the degree of depth of milling cutter vibration abrasion, and milling cutter vibration frequency f _ibe to be n by milling cutter rotating speed, the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃determine, therefore, milling cutter rotating speed is n, and the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃it is the basic controlling variable of milling cutter forced vibration wearing and tearing.

Through identical cutting time t, the state of wear of each tooth of milling cutter is not identical, sets up the multiple tooth vibration abrasion model of milling cutter in adjacent two cutter tooth working angles of this moment.

Feed-speed is V _f(m/min), f _zifor arbitrary neighborhood two between cog feed engagements (mm/z):

Because vibration has directivity, and the vibration frequency of each direction and amplitude there are differences, and the vibration acting on each cutter tooth is also different, causes the different vibration abrasion of each cutter tooth different, produces the inhomogeneous of cutter wear.I wearing and tearing unevenness is constantly as follows:

By computation model, the influence factor of milling cutter forced vibration wearing and tearing is analyzed, and then the forecast milling cutter monodentate degree of wear, character, position and multiple tooth wearing and tearing unevenness.By the analysis to the multiple tooth forced vibration wear model of milling cutter milling cutter, illustrated the impact mechanism of spindle vibration amplitude on cutter wear width in milling cutter forced vibration; The impact mechanism of spindle vibration amplitude on milling cutter front and rear knife face abration position in milling cutter forced vibration; The impact mechanism of spindle vibration frequency on the cutter wear degree of depth in milling cutter forced vibration; Illustrated the impact mechanism of spindle vibration amplitude on cutter wear width unevenness in milling cutter forced vibration; The impact mechanism of spindle vibration amplitude on milling cutter front and rear knife face abration position unevenness in milling cutter forced vibration; The impact mechanism of spindle vibration frequency on cutter wear degree of depth unevenness in milling cutter forced vibration.Having disclosed milling cutter forced vibration is due to the contact relation that has changed milling cutter and workpiece, causes the stress intensity of milling cutter and distribution to change, and wearing and tearing width, wearing depth, the abration position of milling cutter tooth are changed; Because the cutter tooth of milling cutter distributes, cause milling cutter vibration to have phase differential, make milling cutter body vibration be applied to the vibration displacement of local each cutter tooth of milling cutter different, therefore, form the inhomogeneous of the multiple tooth wearing and tearing of milling cutter.

Preferred: the multiple tooth forced vibration Wear evaluation of milling cutter method

First, by forced vibration wear test result, calculate: the abration position unevenness of milling cutter rake face, rear knife face, cutting edge three places wearing and tearing, wearing and tearing width unevenness, wearing depth unevenness, contrast obtains three kinds of unevenness maximal values, i.e. l _{(AD) max}, b _{(AD) max}, h _{(AD) max}all occur in which position.Contact stress between milling cutter and friction of workpiece pair closes:

$\mathrm{\&sigma;}=\frac{F_c}{S}=\frac{{\mathrm{ka}}_e^p{f}_z^q{a}_p{\mathrm{Zd}}^r{n}^m}{S}---\left(15\right)$

In formula: σ is milling cutter and the secondary compressive stress, F of contacting of friction of workpiece _cfor cutting force, S is cutter wear area, a _efor milling width, k, p, q, r, m are respectively coefficient, by different materials, are determined.

The abration position of milling cutter has directly determined the abrasive nature of milling cutter, while considering milling cutter uneven wear, same the different cutter tooth abration positions of milling cutter and wear area are determined to the friction pair character that milling cutter and workpiece form jointly, abrasive nature under each wear area is thought same, therefore, whether whether the wear area that can produce according to two cutter tooth wearing and tearing exist the character of relation of inclusion decision content cutter tooth wearing and tearing consistent, that is:

$\frac{1}{2}{S}_i\&Subset;S_j---\left(18\right)$

In formula: i is the less i tooth of wear area, j is the larger j tooth of wear area.If formula 18 is false, the abration position of two cutters tooth is inhomogeneous, now should first adjust parameter, makes abration position identical.

If formula 18 is set up, analyze friction pair type.When contact stress is greater than yield strength [σ _s] time, milling cutter weares and teares, and sets up thus wear area criterion:

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">S</figure-callout>}}_1<\frac{F_{c1}}{\left[{\mathrm{\&sigma;}}_s\right]}\\ {\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">S</figure-callout>}}_2\&GreaterEqual;\frac{F_{c2}}{\left[{\mathrm{\&sigma;}}_s\right]}\end{array}\right.---\left(16\right)$

This formula has reflected the type of two kinds of friction pairs; Work as S ₁during establishment, friction pair contact area is little, and wear area can change along with the continuation of working angles under the condition of vibration; Work as S ₂during establishment, friction pair contact area is large, and wearing depth can change along with the continuation of working angles under the condition of vibration.

Work as S _i, S _jwhen different, belong to S ₁or S ₂time, the friction pair type of two cutters tooth is different, now should first adjust parameter, makes friction pair type identical.

Work as S _i, S _jall belong to S ₁or S ₂time, consider the cutter wear degree of depth.And the initial stage of wearing and tearing in milling cutter forced vibration, the tool surface of new sharpening is coarse, and microfissure, oxidation or decarburized layer defect, therefore the time of this one-phase is shorter, wearing and tearing are very fast, on this basis, consider whether the increase of wearing depth can cause the variation of wear area S, and then affect the stability of friction pair contact condition.Therefore, the degree of depth of milling cutter forced vibration wearing and tearing should meet:

$\left\{\begin{array}{c}{h}_i\&le;h_{\max }\\ h_i=h_j\end{array}\right.---\left(17\right)$

In formula: wearing and tearing depth capacity h _maxbe 0.05～0.10mm, the size of wear extent is relevant with grinding quality.

Preferred: tool wear unevenness control method

Utilize the impact of the above-mentioned single factor analyzing on milling cutter forced vibration wearing and tearing and wearing and tearing unevenness, control single factor, realize the control to face milling cutters forced vibration wearing and tearing and wearing and tearing unevenness.For Tool Design provides design variable.Because milling cutter exists phasing degree

(i is that cutter tooth code name is from 1 to Z), the amplitude of each cutter tooth of milling cutter is different, and i the cutter tooth of take is benchmark while contacting with workpiece, and the speed of mainshaft is n, if master blade amplitude is A _i(t), so adjacent i+1 tooth amplitude is:

In milling process, under centrifugal force and cutting force excitation, when cutting force becomes large, cutter can produce strong forced vibration, and meanwhile, workpiece also exists vibration in milling process;

Setting milling cutter rotating speed is n, and the number of teeth is Z, and vibration frequency is f ₁; Feed-speed is V _f, vibration frequency is f ₂, therefore, wait the rotation cutting frequency f of tooth pitch milling cutter tooth ₃, the spacing frequency that adjacent two cutters tooth participate in cutting is:

f ₃=nZ （20）

Because cutter and Workpiece vibration all present periodically, when milling cutter vibration frequency is f ₁rotation cutting frequency f with milling cutter tooth ₃when identical, the forced vibration of milling cutter wearing and tearing are uniform wear; Work as f ₁≠ f ₃time, the amplitude of each cutter tooth of milling cutter milling cutter when cutting is all different, causes milling cutter to produce forced vibration uneven wear;

Milling cutter vibration frequency f _idetermined the degree of depth of milling cutter vibration abrasion, and milling cutter vibration frequency f _ibe to be n by milling cutter rotating speed, the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃determine, therefore, milling cutter rotating speed is n, and the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃it is the basic controlling variable of milling cutter forced vibration wearing and tearing;

Cutter cutting vibration behavioral parameters and milling cutter tooth abrasional behavior parameter are decomposed, cutting parameter design variable is carried out to descending sequence, i.e. design sequence to the influence degree of milling cutter tooth forced vibration wearing and tearing; With cutter parameters design variable, to cutting parameter, out of contior forced vibration wearing and tearing compensate design.

Preferred: milling cutter construction design

First, by setting up the milling cutter model of the different numbers of teeth, by finite element modal analysis, study the vibration characteristics of its structure, analyze the impact of the different numbers of teeth on milling vibration.For reduction vibration cutting, raising crudy provide reference and foundation.By UG set up diameter 63mm, the different numbers of teeth etc. tooth milling cutter solid model, be respectively the tooth pitches such as 4 teeth, the 4 teeth tooth pitch milling cutter such as not.

Ansys boundary condition definition: cutter can not can not have rotation vertically and radially axially and radially play occurring or beating, thus all degree of freedom that just must restriction handle of a knife, the constraint condition of Here it is cutter.According to the actual clamping situation of milling cutter, the axial displacement of constraint milling cutter shank, shank cylindrical radial and tangential displacement.When analysis is not subject to load, different number of teeth milling cutter 1～6 rank natural frequency is not as shown in table 4.

The different number of teeth milling cutter of table 4 natural frequency (unit: Hz)

Table 4 is known, and 4 teeth do not wait six first order mode ratios of tooth milling cutter to wait tooth milling cutter little.Under the identical number of teeth, natural frequency is very approaching, is mode compact district; It is larger that natural frequency differs; Second order and three rank natural frequencys differ greatly, and are mode rarefaction.Deng tooth pitch, the variation tendency of its natural frequency is all descending variation.The tooth pitch of this explanation cutter has impact to the natural frequency of cutter, when the natural frequency of cutter approaches the excited frequency of system of processing, just likely causes the resonance of cutter, the generation of flutter, and multitoothed cutter easily vibrates when high-speed milling.

Preferred: to milling cutter construction, experimental verification is carried out in design

For further verifying above-mentioned analysis result, adopt four teeth of development not wait tooth milling cutter: diameter is 63mm, tooth pitch is respectively 88,89,91,92, carry out No. 45 steel experiments of high-speed milling with the flank of tooth milling cutter such as diameter 63mm tetra-teeth, test its vibration characteristics: experiment lathe, workpiece, cutter and experiment parameter are as shown in table 5:

Table 5 confirmatory experiment parameter

Utilize VDL-1000E lathe, to spindle vibration, cutter tooth, wearing and tearing are measured, and measurement result is as shown in table 6, wherein: X be line-spacing direction, Y for axially, Z is direction of feed.

The teeth such as table 6 four teeth vibrate and the contrast of wearing and tearing unevenness result with not waiting experiment of tooth milling cutter

When the variation of cutter parameters and cutting parameter, the forced vibration of milling cutter is occurring to change, and wherein, cutter tooth, cutting-tool angle, tooth pitch are the design variables of cutter; Determine the vibration of this cutter, also be the controlling factor that causes milling cutter forced vibration wearing and tearing to change simultaneously, from experimental result, can find out, its forced vibration and forced vibration wearing and tearing are all improved, four teeth of designing do not wait tooth milling cutter: structure of the cutter body is taper cutter hub, and cutter hub material is 40Cr, and trip bolt adopts fine thread screw, trip bolt material is 35CrMo, and blade is TiN coated cemented carbide insert; Milling cutter diameter d is 63mm, and the cutter amount of overhanging L is 36mm, and the cutter number of teeth is 4 teeth, and tool cutting edge angle is 45 °; Blade is installed anterior angle γ ₀be 2 °, cutter tooth distributes to adopt and does not wait tooth to distribute, and cutter tooth progressive error is 5 °, and diameter is 63mm, and between cog angle is 88,89,91,92; This milling cutter has changed the vibration frequency of milling cutter tooth by changing cutter tooth distribution, reduced the wearing and tearing of milling cutter tooth; Simultaneously, the adjustment to phasing degree apart from distribution by this cutter teeth, make the milling frequency of milling cutter consistent with the vibration frequency of milling cutter, reduced the unevenness of milling cutter forced vibration wearing and tearing, therefore can to milling cutter, design by changing cutter parameters, the forced vibration of milling cutter and forced vibration wearing and tearing and wearing and tearing unevenness are all produced effect, again by changing cutting parameter, when reaching the milling efficiency of processing request, do not change character and the rate of depreciation of wearing and tearing, finally make milling cutter realize the target of high life.

The present invention compared with prior art has following effect:

In face milling cutters milling process, there are three kinds of typical wearing and tearing forms in cutter tooth wearing and tearing: rake wear, wear of the tool flank and cutting edge wearing and tearing.In high-speed machining process, tool wear behavior is the result of multifactor functioning.Control variable is mainly: cutter parameters and cutting parameter; Experimental analysis shows, follows at a high speed, fierce friction and the tool wear that produces, and its form and to form mechanism not only relevant to friction pair chemistry, physics, mechanical property, and also the friction pair variation causing with wearing and tearing and forced vibration is closely related.

Cutter wear unevenness is not only relevant with the degree of wear of each cutter tooth of milling cutter, and the position also occurring with each cutter tooth wearing and tearing form, wearing and tearing is relevant; Between several tool wear forms that observe from experiment, have certain contact, vibration abrasion can cause the degree of wear of certain wearing and tearing form to change, and when the degree of wear changes to a certain degree, state of wear changes.

Realize tool setting odontotripsis control, must start with by tribology and vibration both direction, analysis and Control variable causes tool wear behavior and wearing and tearing unevenness to change on the impact of milling cutter tooth wearing and tearing and cutter wear unevenness and control variable on the impact of forced vibration.From the angle of cutter structure, by milling cutter vibration behavior is controlled, control milling cutter forced vibration wearing and tearing, formed the control method of effective milling cutter forced vibration wearing and tearing, delayed cutter life.A kind of method for designing of high life milling cutter has finally been proposed.Designed 1 four teeth are not waited to tooth milling cutter: diameter is 63mm, and tooth pitch is respectively 88,89,91,92, this milling cutter has reduced the unevenness of wearing and tearing and the milling cutter forced vibration wearing and tearing of milling cutter tooth.

For affect in the external factors such as main consideration cutting parameter of factor of milling cutter vibration abrasion, take, to reduce milling cutter vibration be means in existing milling cutter vibration abrasion research, reaches the effect of the wearing and tearing of the single cutter tooth of inhibition.Adopt and have in this way three aspect problems: the one, although solved the wear problem of single cutter tooth, do not consider a plurality of cutter tooth wearing and tearing non-uniformity problems, ignored the inhomogeneous milling cutter life-span decline problem that causes of a plurality of cutter tooth wearing and tearing of milling cutter; The 2nd, this method is to reduce cutting parameter, take to reduce production efficiency and suppress the wearing and tearing of single cutter tooth as cost, but can not realize the Collaborative Control of a plurality of cutters tooth wearing and tearing; The 3rd, cannot solve cutter tooth wearing and tearing unevenness that machine vibration causes and the milling cutter problem that declines serviceable life.

This invention be take and solved milling cutter forced vibration to cause multiple tooth wearing and tearing non-uniformity problem be object, has proposed to affect the milling cutter vibration behavior recognition methods of multiple tooth wearing and tearing, discloses the forced vibration control variable of the multiple tooth wearing and tearing of milling cutter.

Set up milling cutter forced vibration wear model, illustrate the relation between milling cutter construction, error, cutting parameter, vibration behavioral parameters and cutter tooth abrasional behavior, realized the forecast of each cutter tooth abration position of milling cutter, wear area, wearing depth and effectively controlled, having solved milling cutter stock-removing efficiency and the collision problem in milling cutter life-span.

The multiple tooth forced vibration wearing and tearing unevenness control method of milling cutter and the design method for milling cutter that propose, utilize milling cutter not wait tooth pitch to distribute and can change its forced vibration behavioral trait, the impact of regulation and control lathe and milling cutter vibration tool setting odontotripsis unevenness, solves cutter tooth wearing and tearing unevenness and the milling cutter problem that declines serviceable life.

Accompanying drawing explanation

Fig. 1 is Design Milling process flow diagram; Fig. 2 is milling cutter forced vibration abrasional behavior identification process figure; Fig. 3 is cutter workpiece contact relation figure; Fig. 4 is milling cutter cutting vibration and tool cutting edge angle correlation model figure; Fig. 5 is milling cutter cutting parameter and parameter of cutting layer graph of a relation; Fig. 6 is the tool wear location drawing; Fig. 7 is milling cutter monodentate vibration abrasion illustraton of model; Fig. 8 is the multiple tooth vibration abrasion illustraton of model of milling cutter; Fig. 9 is milling cutter forced vibration Wear evaluation method flow diagram; Figure 10 is the control flow chart of milling cutter forced vibration uneven wear; Figure 11 is the inhomogeneous behavior figure of milling cutter forced vibration; Figure 12 is the teeth such as four teeth and does not wait tooth milling cutter solid model figure; Figure 13 is that diameter 63mm tetra-teeth do not wait tooth milling cutter tooth distribution plan.

Embodiment

Elaborate with reference to the accompanying drawings the preferred embodiment of the present invention below.

A kind of high-speed milling cutter method for designing concrete steps that suppress cutter tooth forced vibration wearing and tearing unevenness of present embodiment are:

1. milling cutter forced vibration wearing and tearing recognition methods

Because process system exists forced vibration in milling process, along with the continuation of working angles, because cutter and workpiece, cutter and smear metal are in contact with one another; With certain linear velocity, mutually move, generation of vibration displacement, forms a kind of Dynamic wear process of following tool cutting process, i.e. the dynamic perfromance of milling cutter forced vibration simultaneously.

The forced vibration meeting of milling cutter causes milling cutter tooth to produce forced vibration wearing and tearing, comprises that milling cutter forced vibration is on milling cutter tooth abrasive nature (being rake wear or wear of the tool flank or cutting edge wearing and tearing), the abration position p(depth capacity position of wearing and tearing), the impact of the degree of wear (width b and wearing depth h wear and tear).Milling cutter forced vibration causes the behavior of a plurality of cutter tooth generation of milling cutter uneven wear, comprises that three kinds of milling cutter uneven wears form mechanism: each odontotripsis different in kind of milling cutter, abration position is inhomogeneous, the degree of wear is inhomogeneous.

For specifically studying intuitively and characterize the forced vibration wearing and tearing of milling cutter, the mode that adopts experiment herein to milling cutter the wearing and tearing under process system forced vibration measure.It is Dalian VDL-1000E lathe that experimental facilities adopts, to tooth pitch F2033.022.040.063 milling cutters such as 63mm diameter 4 teeth, in the workpiece process of No. 45 Steel materials of cutting, vibration cutting adopts eastern magnificent examining system and PCB vibration acceleration sensor to measure, and the testing tool of tool wear is the super depth-of-field microscope of KEYENCE-VHX600 type.For understanding the mutual relationship between forced vibration and tool wear, utilize gray system theory modeling software, Milling Parameters is: milling cutter feed engagement f _z=0.08～0.15mm/z, cutting linear velocity v _c=435～614m/min, cutting-in a _p=0.3～0.5mm, carries out grey correlation analysis to the vibration cutting under above parameter and wearing and tearing.

Table 1 forced vibration and abrasional behavior parameter grey correlation analysis

Known according to table 1 interpretation of result: 1. rake wear width b _beforeclose with main shaft line-spacing amplitude, axis feeding amplitude relation; 2. rake face greatest wear degree of depth h _beforeclose with main shaft main shaft line-spacing amplitude relation; 3. axially shake frequency, axis feeding amplitude, axis feeding of rake face greatest wear depth location and main shaft axial amplitude, main shaft shakes frequently in close relations; 4. wear of the tool flank width b _afterin close relations with main shaft axial amplitude; 5. knife face greatest wear degree of depth h after _afterwith main shaft axial amplitude; 6. knife face greatest wear depth location and main shaft line-spacing amplitude, main shaft frequency, axis feeding amplitude, the axis feeding frequency that shakes that axially shakes after.

In addition, each cutter tooth of milling cutter is due to cutter structure, error and machining condition impact, each odontotripsis is different, the tool wear of wearing and tearing degree of irregularity: for the cutter with a plurality of cutters tooth, when milling, each cutter tooth participates in cutting simultaneously, but due to vibration cutting, make cutter different in the wear extent of different cutters tooth, i.e. a plurality of tool wear degrees of irregularity.Tool wear degree of irregularity can cause cutting stability variation, and machined surface quality changes.By the mean value AD size of the mean difference numerical value of the wear extent of each cutter tooth, evaluate the degree of irregularity of a plurality of cutters tooth wearing and tearing.Constantly rake wear degree of depth unevenness is as shown in Equation 1 for i:

Utilize gray system theory modeling software, above six groups of parametric vibrations and wearing and tearing unevenness experimental result are carried out to grey correlation analysis.

Table 2 forced vibration and wearing and tearing unevenness grey correlation analysis

Known according to table 2 analysis result:

1. rake wear width unevenness and main shaft line-spacing amplitude, main shaft axial amplitude, axis feeding shake frequently in close relations; 2. it is frequently in close relations that rake wear degree of depth unevenness and main shaft line-spacing shake frequently, main shaft axially shakes frequently, axis feeding shakes, and wherein main shaft line-spacing shakes frequently on its impact significantly; 3. wear of the tool flank width unevenness and main shaft line-spacing amplitude, axis feeding amplitude have relation, and wherein the impact of main shaft line-spacing amplitude significantly; 4. it is frequently relevant that wear of the tool flank degree of depth unevenness is shaken frequently with main shaft line-spacing, main shaft axially shakes frequently, axis feeding shakes, and wherein the impact of axis feeding amplitude significantly.

By above-mentioned conclusion, can be found out, wearing and tearing width unevenness and the milling cutter Oscillation Amplitude of forward and backward cutter are in close relations, forward and backward knife face wearing depth unevenness and milling cutter vibration frequency are in close relations, this is because cutter and Workpiece vibration all present periodically, when the rotation cutting frequency of milling cutter vibration frequency and milling cutter tooth is different, the amplitude of each cutter tooth of milling cutter milling cutter when cutting is all different, and the forced vibration wearing and tearing that cause milling cutter are uneven wear.

By above-mentioned association analysis, obtained the physical relationship mapping of milling cutter forced vibration behavior to abrasional behavior, can, by the observation to vibration behavior, realize the identification to face milling cutters forced vibration abrasional behavior, (see figure 2).

Adopt above-mentioned recognition methods, utilize the associate feature of face milling cutters forced vibration and cutter tooth wearing and tearing and wearing and tearing unevenness, form the physical relationship mapping of milling cutter forced vibration behavior to cutter wear behavior, can identify the behavioral parameters of milling cutter forced vibration behavioral parameters, cutter wear behavioral parameters, milling cutter uneven wear; Milling cutter forced vibration behavior affects relation to three of milling cutter tooth abrasional behavior kinds; Milling cutter forced vibration behavior affects relation to three kinds of the behavior of milling cutter uneven wear; The forced vibration control variable of milling cutter monodentate abrasional behavior and the behavior of milling cutter uneven wear.

2. the multiple tooth forced vibration abrasion forecasting method of milling cutter

From experiment, find out that the description of complete high-speed milling vibration signal characterizes respectively from three directions of dynamic behavior: the behavior of line-spacing directional dynamics; Direction of feed dynamic behavior; Axial direction dynamic behavior.Comprise three direction main frequency of vibration sizes and amplitude corresponding to main frequency of vibration.

The whole forced vibration meeting of milling cutter changes milling cutter position of tool tip and changes, contact relation, the actual cut angle of cutter, the parameter of cutting layer of cutter tooth and workpiece have been changed simultaneously, for the impact of research milling cutter forced vibration and cutter tooth position relationship tool setting odontotripsis, take the round heart of cutter tooth center pit as true origin, direction of feed as X-axis, line-spacing direction sets up Descartes's rectangular coordinate system as Y-axis, major axes orientation as Z axis.Milling cutter at a time cutter tooth i participates in cutting, and now milling cutter vibration displacement is S _vibration, be equivalent to milling cutter and be rocked to dotted line position, cutter tooth i this constantly position of tool tip by J _ito J ' _i.If cutter hub threaded hole radius is r _{spiral shell}, point width cutter hub threaded hole distance of center circle is from being l _blade, the mismachining tolerance of blade i is Δ _1i, the rigging error of blade on this cutter is Δ _2i, position of tool tip J before vibrating _icoordinate is:

If milling cutter vibration displacement is S _vibrationwith X-axis angle be θ _ix, with Y-axis angle be θ _iy, with Z axis angle be θ _iz, milling cutter is position of tool tip J ' after vibration _icoordinate is:

Cutter and the workpiece contact geometry model (see figure 3) set up herein, analyze the actual cut length of Tool in Cutting sword and the relation between the area of cut, in Milling Process, the actual cut length of cutter blade is main cutting edge (line segment OA) and front cutting edge (line segment EB) and line segment OE sum, it is not only relevant with tool cutting edge angle and auxiliary angle, goes back and cutting parameter (feed engagement f _zwith cutting depth a _p) relevant.

K _rfor tool cutting edge angle, k ' _rfor auxiliary angle, work as f _z>a _p(cotk _r+ cotk ' _r) time, the actual cut length of blade and the amount of feeding are irrelevant, generally, and f _z<a _p(cotk _r+ cotk ' _r), at this, we only analyze a kind of situation below, by geometric analysis, are easy to obtain the main cutting edge length l that participates in cutting _oAwith front cutting edge length l _oBexpression formula:

$\left\{\begin{array}{c}{l}_{\mathrm{OA}}=\frac{a_p}{\sin k_r}\\ l_{\mathrm{OB}}=\frac{f_z}{(\cot k_r+\cot k_r^{\&prime;})\sin k_r^{\&prime;}}\end{array}\right.---\left(4\right)$

Take point of a knife as initial point, and direction of feed is X-axis, and line-spacing direction is Y-axis, and major axes orientation is that Z axis is set up cartesian coordinate system, sets up milling cutter cutting vibration and tool cutting edge angle correlation model (see figure 4).

The displacement that milling cutter tooth produces by vibrating is S _vibration, being equivalent to cutter tooth and swinging θ angle from initial position, tool cutting edge angle is by k _rbecome k _r1, θ _s1for S _vibrationin YOZ plane, with the angle of Y-axis, by trigonometric function relation, can be obtained:

k _r1=k _r+2θ _S1 (5)

In like manner, milling cutter anterior angle γ ₀, relief angle α ₀in XOZ plane, cutter tooth swings θ from initial position ₁angle, anterior angle is by γ ₀become γ ₀₁, relief angle is by α ₀become α ₀₁, cutting edge inclination is by λ _sbecome λ _s1, θ _s2for S _vibrationin YOZ plane with the angle of X-axis, θ _s3for S _vibrationin XOY plane, with the angle of Y-axis, by trigonometric function relation, can be obtained:

$\left\{\begin{array}{c}{\mathrm{\&gamma;}}_{01}={\mathrm{\&gamma;}}_0+{2\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">S</figure-callout>}2}\\ {\mathrm{\&alpha;}}_{01}={\mathrm{\&alpha;}}_0-{2\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">S</figure-callout>}2}\\ {\mathrm{\&lambda;}}_{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">s</figure-callout>}1}={\mathrm{\&lambda;}}_s+{2\mathrm{\&theta;}}_{S3}\end{array}\right.---\left(6\right)$

Set up face milling cutters when milling, cutting parameter and parameter of cutting layer relational model (see figure 5).

Feed-speed is V _f(m/min), f _zifor arbitrary neighborhood two between cog feed engagements (mm/z), there is phasing degree in milling cutter

(i is that cutter tooth code name is from 1 to Z).

Because milling cutter cutter workpiece in milling process all exists vibration, through cutting time t, when milling cutter is f in this moment vibration frequency _itime, after milling cutter, knife face and the work piece contact point vibration abrasion degree of depth are h _after, the amplitude of cutter and workpiece is respectively A _cutter, A _workpiece:

Tool wear position is to take position of tool tip as initial point, along main cutting edge direction, is X-axis, and rake face normal direction is Z axis in the other direction, sets up the rectangular coordinate system of (see figure 6), and making P point coordinate is (x _p, y _p, z _p), therefore, P point is apart from point width from being:

$l_P=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="x\; p"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">x</figure-callout>}}_p^{}+{\mathrm{<figure-callout\; id="2"\; label="y\; p"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">y</figure-callout>}}_p^{}+z_p^2}---\left(9\right)$

The position of tool wear is different, represents that the abrasive nature of cutter is different, when P point is positioned at rake face and has a segment distance apart from cutting edge, is crescent hollow abrasion, while being positioned at rear knife face, is wear of the tool flank, if occur on cutting edge, is micro-tipping.

Milling cutter vibrometer reveals the vibration characteristics being combined by low-frequency vibration and dither, this vibration characteristics of milling cutter makes to produce little amplitude to-and-fro movement between itself and work piece close contact surface, and in single cutter tooth working angles, contact interface does not have the chance exposing, and abrasive particle is difficult to the friction surface of escaping out.Therefore, in single cutter tooth working angles, between milling cutter and work piece surface in contact, not only there is unidirectional sliding frictional wear, and have the vibration abrasion under adhesive wear and the effect of abrasive wear mixing mechanism.Milling cutter vibration and vibration abrasion model (see figure 7) thereof in cutter tooth working angles:

Through cutting time t, when milling cutter is f in i moment vibration frequency _itime, knife face and work piece contact point vibration abrasion change in depth Δ h after milling cutter _after, rake wear wide variety Δ b _before, rake wear change in depth Δ h _before, cutting-in is from a _pbecome a ' _p, feed engagement is by f _zbecome f ' _z, the vibration displacement of cutter and workpiece is respectively vector S _cutter, S _workpiece, this moment milling cutter forced vibration behavioral parameters and milling cutter monodentate abrasional behavior parameters relationship are:

When larger cutting force produces strong forced vibration, while making a plurality of frequency multiplication of milling cutter generation of vibration, the cutter wear degree of depth will increase exponentially.With this understanding, cutter wear amount constantly increased with the cutting time, and the wearing and tearing of vibrating from milling cutter will make milling cutter and work piece contact interface under completely reserved stress effect, cause larger vibration abrasion.Milling cutter vibration frequency f _idetermined the degree of depth of milling cutter vibration abrasion, and milling cutter vibration frequency f _ibe to be n by milling cutter rotating speed, the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃determine, therefore, milling cutter rotating speed is n, and the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃it is the basic controlling variable of milling cutter forced vibration wearing and tearing.

Through identical cutting time t, the state of wear of each tooth of milling cutter is not identical, therefore, sets up the multiple tooth vibration abrasion model of milling cutter (see figure 8) in adjacent two cutter tooth working angles of this moment:

Feed-speed is V _f(m/min), f _zifor arbitrary neighborhood two between cog feed engagements (mm/z):

Because vibration has directivity, and the vibration frequency of each direction and amplitude there are differences, and the vibration acting on each cutter tooth is also different, causes the different vibration abrasion of each cutter tooth different, produces the inhomogeneous of cutter wear.I wearing and tearing unevenness is constantly as follows:

By computation model, the influence factor of milling cutter forced vibration wearing and tearing is analyzed, and then the forecast milling cutter monodentate degree of wear, character, position and multiple tooth wearing and tearing unevenness.By the analysis to the multiple tooth forced vibration wear model of milling cutter milling cutter, illustrated the impact mechanism of spindle vibration amplitude on cutter wear width in milling cutter forced vibration; The impact mechanism of spindle vibration amplitude on milling cutter front and rear knife face abration position in milling cutter forced vibration; The impact mechanism of spindle vibration frequency on the cutter wear degree of depth in milling cutter forced vibration; Illustrated the impact mechanism of spindle vibration amplitude on cutter wear width unevenness in milling cutter forced vibration; The impact mechanism of spindle vibration amplitude on milling cutter front and rear knife face abration position unevenness in milling cutter forced vibration; The impact mechanism of spindle vibration frequency on cutter wear degree of depth unevenness in milling cutter forced vibration.Having disclosed milling cutter forced vibration is due to the contact relation that has changed milling cutter and workpiece, causes the stress intensity of milling cutter and distribution to change, and wearing and tearing width, wearing depth, the abration position of milling cutter tooth are changed; Because the cutter tooth of milling cutter distributes, cause milling cutter vibration to have phase differential, make milling cutter body vibration be applied to the vibration displacement of local each cutter tooth of milling cutter different, therefore, form the inhomogeneous of the multiple tooth wearing and tearing of milling cutter.

3. the multiple tooth forced vibration Wear evaluation of milling cutter method

Tool wear degree of irregularity can cause cutting stability variation, and machined surface quality changes, and therefore, it is very important that milling cutter uneven wear is passed judgment on.From the friction pair of milling cutter and workpiece, start with herein, analyze cutter wear character, wear area, the degree of wear, propose the criterion of milling cutter uneven wear, define goal of regulation and control.

First, by forced vibration wear test result, calculate: the abration position unevenness of milling cutter rake face, rear knife face, cutting edge three places wearing and tearing, wearing and tearing width unevenness, wearing depth unevenness, contrast obtains three kinds of unevenness maximal values, i.e. l _{(AD) max}, b _{(AD) max}, h _{(AD) max}all occur in which position.Contact stress between milling cutter and friction of workpiece pair closes:

$\mathrm{\&sigma;}=\frac{F_c}{S}=\frac{{\mathrm{ka}}_e^p{f}_z^q{a}_p{\mathrm{Zd}}^r{n}^m}{S}---\left(15\right)$

In formula: σ is milling cutter and the secondary compressive stress, F of contacting of friction of workpiece _cfor cutting force, S is cutter wear area, a _efor milling width, k, p, q, r, m are respectively coefficient, by different materials, are determined.

The abration position of milling cutter has directly determined the abrasive nature of milling cutter, while considering milling cutter uneven wear, same the different cutter tooth abration positions of milling cutter and wear area are determined to the friction pair character that milling cutter and workpiece form jointly, abrasive nature under each wear area is thought same, therefore, whether whether the wear area that can produce according to two cutter tooth wearing and tearing exist the character of relation of inclusion decision content cutter tooth wearing and tearing consistent, that is:

$\frac{1}{2}{S}_i\&Subset;S_j---\left(18\right)$

In formula: i is the less i tooth of wear area, j is the larger j tooth of wear area.If formula 18 is false, the abration position of two cutters tooth is inhomogeneous, now should first adjust parameter, makes abration position identical.

If formula 18 is set up, analyze friction pair type.When contact stress is greater than yield strength [σ _s] time, milling cutter weares and teares, and sets up thus wear area criterion:

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">S</figure-callout>}}_1<\frac{F_{c1}}{\left[{\mathrm{\&sigma;}}_s\right]}\\ {\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HDA0000458860070000052.png"\; state="\{\{state\}\}">S</figure-callout>}}_2\&GreaterEqual;\frac{F_{c2}}{\left[{\mathrm{\&sigma;}}_s\right]}\end{array}\right.---\left(16\right)$

This formula has reflected the type of two kinds of friction pairs; Work as S ₁during establishment, friction pair contact area is little, and wear area can change along with the continuation of working angles under the condition of vibration; Work as S ₂during establishment, friction pair contact area is large, and wearing depth can change along with the continuation of working angles under the condition of vibration.

Work as S _i, S _jwhen different, belong to S ₁or S ₂time, the friction pair type of two cutters tooth is different, now should first adjust parameter, makes friction pair type identical.

Work as S _i, S _jall belong to S ₁or S ₂time, consider the cutter wear degree of depth.And the initial stage of wearing and tearing in milling cutter forced vibration, the tool surface of new sharpening is coarse, and microfissure, oxidation or decarburized layer defect, therefore the time of this one-phase is shorter, wearing and tearing are very fast, on this basis, consider whether the increase of wearing depth can cause the variation of wear area S, and then affect the stability of friction pair contact condition.Therefore, the degree of depth of milling cutter forced vibration wearing and tearing should meet:

$\left\{\begin{array}{c}{h}_i\&le;h_{\max }\\ h_i=h_j\end{array}\right.---\left(17\right)$

In formula: wearing and tearing depth capacity h _maxbe 0.05～0.10mm, the size of wear extent is relevant with grinding quality.

To sum up, the evaluation method (see figure 9) of milling cutter forced vibration wearing and tearing:

4. suppress method for designing and the checking of milling cutter uneven wear

Utilize the impact of the above-mentioned single factor analyzing on milling cutter forced vibration wearing and tearing and wearing and tearing unevenness, control single factor, realize the control to face milling cutters forced vibration wearing and tearing and wearing and tearing unevenness.Control flow (see figure 10), for Tool Design provides design variable.

Because milling cutter exists phasing degree

(i is that cutter tooth code name is from 1 to Z), the amplitude of each cutter tooth of milling cutter is different, and i the cutter tooth of take is benchmark while contacting with workpiece, and the speed of mainshaft is n, if master blade amplitude is A _i(t), so adjacent i+1 tooth amplitude is:

In milling process, under centrifugal force and cutting force excitation, when cutting force becomes large, cutter can produce strong forced vibration, and meanwhile, workpiece also exists vibration (seeing Figure 11) in milling process.

Milling cutter rotating speed is n, and the number of teeth is Z, and vibration frequency is f ₁; Feed-speed is V _f, vibration frequency is f ₂.Therefore, wait the rotation cutting frequency f of tooth pitch milling cutter tooth ₃, the spacing frequency that adjacent two cutters tooth participate in cutting is:

f ₃=nZ （20）

Because cutter and Workpiece vibration all present periodically, when milling cutter vibration frequency is f ₁rotation cutting frequency f with milling cutter tooth ₃when identical, the forced vibration of milling cutter wearing and tearing are uniform wear.

Work as f ₁≠ f ₃time, the amplitude of each cutter tooth of milling cutter milling cutter when cutting is all different, causes milling cutter to produce forced vibration uneven wear.

Milling cutter vibration frequency f _idetermined the degree of depth of milling cutter vibration abrasion, and milling cutter vibration frequency f _ibe to be n by milling cutter rotating speed, the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃determine, therefore, milling cutter rotating speed is n, and the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃it is the basic controlling variable of milling cutter forced vibration wearing and tearing.

Cutter cutting vibration behavioral parameters and milling cutter tooth abrasional behavior parameter are decomposed, cutting parameter design variable is carried out to descending sequence, i.e. design sequence to the influence degree of milling cutter tooth forced vibration wearing and tearing; With cutter parameters design variable, to cutting parameter, out of contior forced vibration wearing and tearing compensate design.

First, by setting up the milling cutter model of the different numbers of teeth, by finite element modal analysis, study the vibration characteristics of its structure, analyze the impact of the different numbers of teeth on milling vibration.For reduction vibration cutting, raising crudy provide reference and foundation.By UG set up diameter 63mm, the different numbers of teeth etc. tooth milling cutter solid model (seeing Figure 12), be respectively the tooth pitches such as 4 teeth, the 4 teeth tooth pitch milling cutter such as not.

Material of cutting-tool is 40Cr, and its material parameter is as shown in table 3.

Table 3 material of cutting-tool parameter

Ansys boundary condition definition: cutter can not can not have rotation vertically and radially axially and radially play occurring or beating, thus all degree of freedom that just must restriction handle of a knife, the constraint condition of Here it is cutter.According to the actual clamping situation of milling cutter, the axial displacement of constraint milling cutter shank, shank cylindrical radial and tangential displacement.While not being subject to load, two milling cutter 1～6 rank natural frequencys, as shown in table 4.

The different number of teeth milling cutter of table 4 natural frequency (unit: Hz)

As known from Table 4,4 teeth do not wait six first order mode ratios of tooth milling cutter to wait tooth milling cutter little.Under the identical number of teeth, natural frequency is very approaching, is mode compact district; It is larger that natural frequency differs; Second order and three rank natural frequencys differ greatly, and are mode rarefaction.Deng tooth pitch, the variation tendency of its natural frequency is all descending variation.The tooth pitch of this explanation cutter has impact to the natural frequency of cutter, when the natural frequency of cutter approaches the excited frequency of system of processing, just likely causes the resonance of cutter, the generation of flutter, and multitoothed cutter easily vibrates when high-speed milling.

For further verifying above-mentioned analysis result, adopt four teeth of development not wait tooth milling cutter: diameter is 63mm, and tooth pitch is respectively 88,89,91,92, carry out No. 45 steel experiments of high-speed milling with the flank of tooth milling cutter such as diameter 63mm tetra-teeth, test its vibration characteristics, high-speed milling cutter two dimensional model (seeing Figure 13)

Experiment lathe, workpiece, cutter and experiment parameter are as shown in table 5:

Table 5 confirmatory experiment parameter

Utilize VDL-1000E lathe, to spindle vibration, cutter tooth, wearing and tearing are measured, and measurement result is as shown in table 6, wherein: X be line-spacing direction, Y for axially, Z is direction of feed:

The teeth such as table 6 four teeth vibrate and the contrast of wearing and tearing unevenness result with not waiting experiment of tooth milling cutter

When the variation of cutter parameters and cutting parameter, the forced vibration of milling cutter is occurring to change, and wherein, cutter tooth, cutting-tool angle, tooth pitch are the design variables of cutter; Determine the vibration of this cutter, also be the controlling factor that causes milling cutter forced vibration wearing and tearing to change simultaneously, from experimental result, can find out, its forced vibration and forced vibration wearing and tearing and surface quality consistance are all improved, four teeth of designing do not wait tooth milling cutter: structure of the cutter body is taper cutter hub, and cutter hub material is 40Cr, and trip bolt adopts fine thread screw, trip bolt material is 35CrMo, and blade is TiN coated cemented carbide insert; Milling cutter diameter d is 63mm, and the cutter amount of overhanging L is 36mm, and the cutter number of teeth is 4 teeth, and tool cutting edge angle is 45 °; It is 2 ° that blade is installed anterior angle γ 0, and cutter tooth distributes to adopt and do not wait tooth to distribute, and cutter tooth progressive error is 5 °, and diameter is 63mm, and between cog angle is 88,89,91,92; This milling cutter has changed the vibration frequency of milling cutter tooth by changing cutter tooth distribution, reduced the wearing and tearing of milling cutter tooth; Simultaneously, the adjustment to phasing degree apart from distribution by this cutter teeth, make the milling frequency of milling cutter consistent with the vibration frequency of milling cutter, reduced the unevenness of milling cutter forced vibration wearing and tearing, therefore can to milling cutter, design by changing cutter parameters, the forced vibration of milling cutter and forced vibration wearing and tearing and wearing and tearing unevenness (life-span) are all produced effect, again by changing cutting parameter, when reaching the milling efficiency of processing request, do not change character and the rate of depreciation of wearing and tearing, finally make milling cutter realize the target of high life.

Claims (7)

1. a high-speed milling cutter method for designing that suppresses cutter tooth forced vibration wearing and tearing unevenness, is characterized in that, the concrete steps of described design method for milling cutter are:

Step 1, according to the test result of milling cutter forced vibration wear test, milling cutter forced vibration behavior and cutter wear behavior are carried out to association analysis, obtained the associate feature of milling cutter forced vibration behavior and cutter wear behavior; Tool wear behavior while having analyzed facing cut Tool in Milling metal material; The cutting characteristic of milling tool processing different materials below contrast different parameters, the impact of opposite milling cutter wearing and tearing; The recognition methods of milling cutter forced vibration wearing and tearing has been proposed;

Step 2, theoretical according to vibration, has analyzed the vibration behavior of milling cutter in milling process, and has carried out parametrization sign; The feature of several main wearing and tearing forms while having analyzed face milling cutters milling metal material, and the morphogenetic position of respectively wearing and tearing, and the wearing and tearing form of face milling cutters is carried out to parametrization sign; Illustrated the impact mechanism of several milling cutter forced vibration behaviors on cutter wear behavior; Analyze the impact of forced vibration behavior on cutter wear behavior; Wearing and tearing based in face milling cutters cutting process, damaged theoretical, analyze the impact on cutter wear such as cutting speed, vibration cutting and cutting force in working angles, disclose the impact mechanism of milling cutter forced vibration on cutter wear and wearing and tearing unevenness; Set up the multiple tooth forced vibration wear model of milling cutter, propose forecast and the evaluation method of milling cutter forced vibration wearing and tearing and uneven wear, differentiate friction pair character, classification;

The impact mechanism of milling cutter forced vibration on cutter wear and wearing and tearing unevenness in step 3, foundation, the control method of milling cutter forced vibration wearing and tearing unevenness has been proposed, disclose the impact of milling cutter forced vibration behavior on cutter wear behavior, realize the effective control to face milling cutters forced vibration wearing and tearing;

Step 4, according to milling cutter model analysis and vibration abrasion experimental result, the accuracy of checking milling cutter control method, solve the collision of variables problem in control method, solve control loop, adopt this control method, by the design of cutter parameters, cutting parameter, the method for designing of milling cutter is proposed, adopt the mode of testing to verify feasibility, the accuracy of method for designing.

2. a kind of design method for milling cutter that suppresses cutter tooth forced vibration wearing and tearing unevenness according to claim 1, is characterized in that: the recognition methods of milling cutter forced vibration wearing and tearing

The forced vibration meeting of milling cutter causes milling cutter tooth to produce forced vibration wearing and tearing, comprises that milling cutter forced vibration is on milling cutter tooth abrasive nature (being rake wear or wear of the tool flank or cutting edge wearing and tearing), the abration position p(depth capacity position of wearing and tearing), the impact of the degree of wear (width b and wearing depth h wear and tear); Milling cutter forced vibration causes the behavior of a plurality of cutter tooth generation of milling cutter uneven wear, comprises that three kinds of milling cutter uneven wears form mechanism: each odontotripsis different in kind of milling cutter, abration position is inhomogeneous, the degree of wear is inhomogeneous;

For specifically studying intuitively and characterize the forced vibration wearing and tearing of milling cutter, the mode that adopts experiment herein to milling cutter the wearing and tearing under process system forced vibration measure; It is Dalian VDL-1000E lathe that experimental facilities adopts, to tooth pitch F2033.022.040.063 milling cutters such as 63mm diameter 4 teeth, in the workpiece process of No. 45 Steel materials of cutting, vibration cutting adopts eastern magnificent examining system and PCB vibration acceleration sensor to measure, and the testing tool of tool wear is the super depth-of-field microscope of KEYENCE-VHX600 type; For understanding the mutual relationship between forced vibration and tool wear, utilize gray system theory modeling software, Milling Parameters is: milling cutter feed engagement f _z=0.08～0.15mm/z, cutting linear velocity v _c=435～614m/min, cutting-in a _p=0.3～0.5mm, carries out grey correlation analysis to the vibration cutting under above parameter and wearing and tearing; Wearing and tearing width unevenness and the milling cutter Oscillation Amplitude of forward and backward cutter are in close relations, forward and backward knife face wearing depth unevenness and milling cutter vibration frequency are in close relations, this is because cutter and Workpiece vibration all present periodically, when the rotation cutting frequency of milling cutter vibration frequency and milling cutter tooth is different, the amplitude of each cutter tooth of milling cutter milling cutter when cutting is all different, and the forced vibration wearing and tearing that cause milling cutter are uneven wear;

Utilize the associate feature of face milling cutters forced vibration and cutter tooth wearing and tearing and wearing and tearing unevenness, form the physical relationship mapping of milling cutter forced vibration behavior to cutter wear behavior, can identify the behavioral parameters of milling cutter forced vibration behavioral parameters, cutter wear behavioral parameters, milling cutter uneven wear; Milling cutter forced vibration behavior affects relation to three of milling cutter tooth abrasional behavior kinds; Milling cutter forced vibration behavior affects relation to three kinds of the behavior of milling cutter uneven wear; The forced vibration control variable of milling cutter monodentate abrasional behavior and the behavior of milling cutter uneven wear; Obtain the physical relationship mapping of milling cutter forced vibration behavior to abrasional behavior, can, by the observation to vibration behavior, realize the identification of opposite cutter wear behavior in milling process.

3. a kind of high-speed milling cutter method for designing that suppresses cutter tooth forced vibration wearing and tearing unevenness according to claim 2, is characterized in that: the multiple tooth forced vibration abrasion forecasting method of milling cutter;

The description of complete high-speed milling vibration signal, characterizes respectively from three directions of dynamic behavior: the behavior of line-spacing directional dynamics; Direction of feed dynamic behavior; Axial direction dynamic behavior; Comprise three direction main frequency of vibration sizes and amplitude corresponding to main frequency of vibration;

The whole forced vibration meeting of milling cutter changes milling cutter position of tool tip and changes, contact relation, the actual cut angle of cutter, the parameter of cutting layer of cutter tooth and workpiece have been changed simultaneously, for the impact of research milling cutter forced vibration and cutter tooth position relationship tool setting odontotripsis, take the round heart of cutter tooth center pit as true origin, direction of feed as X-axis, line-spacing direction sets up Descartes's rectangular coordinate system as Y-axis, major axes orientation as Z axis; Milling cutter at a time cutter tooth i participates in cutting, and now milling cutter vibration displacement is S _vibration, be equivalent to milling cutter and be rocked to dotted line position, cutter tooth i this constantly position of tool tip by J _ito J ' _i; If cutter hub threaded hole radius is r spiral shell, point width cutter hub threaded hole distance of center circle is from being l _blade, the mismachining tolerance of blade i is Δ 1 _i, the rigging error of blade on this cutter is Δ 2 _i, position of tool tip J before vibrating _icoordinate is:

If milling cutter vibration displacement is S, vibration is θ with X-axis angle _ix, with Y-axis angle be θ _iy, with Z axis angle be θ _iz, milling cutter is position of tool tip J ' after vibration _icoordinate is:

Set up cutter and workpiece contact geometry model herein, analyze the actual cut length of Tool in Cutting sword and the relation between the area of cut, in Milling Process, the actual cut length of cutter blade is main cutting edge (line segment OA) and front cutting edge (line segment EB) and line segment OE sum, it is not only relevant with tool cutting edge angle and auxiliary angle, goes back and cutting parameter (feed engagement f _zwith cutting depth a _p) relevant;

K _rfor tool cutting edge angle, k ' _rfor auxiliary angle, work as f _z>a _p(cotk _r+ cotk ' _r) time, the actual cut length of blade and the amount of feeding are irrelevant, generally, and f _z<a _p(cotk _r+ cotk ' _r), at this, we only analyze a kind of situation below, by geometric analysis, are easy to obtain the main cutting edge length l that participates in cutting _oAwith front cutting edge length l _oBexpression formula:

Take point of a knife as initial point, and direction of feed is X-axis, and line-spacing direction is Y-axis, and major axes orientation is that Z axis is set up cartesian coordinate system, sets up milling cutter cutting vibration and tool cutting edge angle correlation model; The displacement that milling cutter tooth produces by vibrating is S _vibration, being equivalent to cutter tooth and swinging θ angle from initial position, tool cutting edge angle is by k _rbecome k _r1, θ _s1for S _vibrationin YOZ plane with the angle of Y-axis,, by trigonometric function relation, can be obtained:

k _r1=k _r+2θ _S1 (5)

In like manner, milling cutter anterior angle γ ₀, relief angle α ₀in XOZ plane, cutter tooth swings θ from initial position ₁angle, anterior angle is by γ ₀become γ ₀₁, relief angle is by α ₀become α ₀₁, cutting edge inclination is by λ _sbecome λ _s1, θ _s2for S _vibrationin YOZ plane with the angle of X-axis, θ _s3for S _vibrationin XOY plane, with the angle of Y-axis, by trigonometric function relation, can be obtained:

Face milling cutters when milling, cutting parameter and parameter of cutting layer: feed-speed is V _f(m/min), f _zifor arbitrary neighborhood two between cog feed engagements (mm/z), there is phasing degree in milling cutter

(i is that cutter tooth code name is from 1 to Z);

Because milling cutter cutter workpiece in milling process all exists vibration, through cutting time t, when milling cutter is f in this moment vibration frequency _itime, after milling cutter, knife face and the work piece contact point vibration abrasion degree of depth are h _after, the amplitude of cutter and workpiece is respectively A _cutter, A _workpiece:

Tool wear position is to take position of tool tip as initial point, along main cutting edge direction, is X-axis, and rake face normal direction is Z axis in the other direction, sets up rectangular coordinate system, and making P point coordinate is (x _p, y _p, z _p), therefore, P point is apart from point width from being:

The position of tool wear is different, represents that the abrasive nature of cutter is different, when P point is positioned at rake face and has a segment distance apart from cutting edge, is crescent hollow abrasion, while being positioned at rear knife face, is wear of the tool flank, if occur on cutting edge, is micro-tipping;

Milling cutter vibrometer reveals the vibration characteristics being combined by low-frequency vibration and dither, this vibration characteristics of milling cutter makes to produce little amplitude to-and-fro movement between itself and work piece close contact surface, and in single cutter tooth working angles, contact interface does not have the chance exposing, and abrasive particle is difficult to the friction surface of escaping out; Therefore, in single cutter tooth working angles, between milling cutter and work piece surface in contact, not only there is unidirectional sliding frictional wear, and have the vibration abrasion under adhesive wear and the effect of abrasive wear mixing mechanism; Milling cutter vibration and vibration abrasion model thereof in cutter tooth working angles;

Through cutting time t, when milling cutter is f in i moment vibration frequency _itime, after milling cutter, after knife face and work piece contact point vibration abrasion change in depth Δ h, before rake wear wide variety Δ b, before rake wear change in depth Δ h, cutting-in is from a _pbecome a ' _p, feed engagement is by f _zbecome f ' _z, the vibration displacement of cutter and workpiece is respectively vector S cutter, S workpiece, and this moment milling cutter forced vibration behavioral parameters and milling cutter monodentate abrasional behavior parameters relationship are:

When larger cutting force produces strong forced vibration, while making a plurality of frequency multiplication of milling cutter generation of vibration, the cutter wear degree of depth will increase exponentially; With this understanding, cutter wear amount constantly increased with the cutting time, and the wearing and tearing of vibrating from milling cutter will make milling cutter and work piece contact interface under completely reserved stress effect, cause larger vibration abrasion; Milling cutter vibration frequency f _idetermined the degree of depth of milling cutter vibration abrasion, and milling cutter vibration frequency f _ibe to be n by milling cutter rotating speed, the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃determine, therefore, milling cutter rotating speed is n, and the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃it is the basic controlling variable of milling cutter forced vibration wearing and tearing;

Through identical cutting time t, the state of wear of each tooth of milling cutter is not identical, sets up the multiple tooth vibration abrasion model of milling cutter in adjacent two cutter tooth working angles of this moment;

Feed-speed is V _f(m/min), f _zifor arbitrary neighborhood two between cog feed engagements (mm/z):

Because vibration has directivity, and the vibration frequency of each direction and amplitude there are differences, and the vibration acting on each cutter tooth is also different, causes the different vibration abrasion of each cutter tooth different, produces the inhomogeneous of cutter wear; I wearing and tearing unevenness is constantly as follows:

By computation model, the influence factor of milling cutter forced vibration wearing and tearing is analyzed, and then the forecast milling cutter monodentate degree of wear, character, position and multiple tooth wearing and tearing unevenness; By the analysis to the multiple tooth forced vibration wear model of milling cutter milling cutter, illustrated the impact mechanism of spindle vibration amplitude on cutter wear width in milling cutter forced vibration; The impact mechanism of spindle vibration amplitude on milling cutter front and rear knife face abration position in milling cutter forced vibration; The impact mechanism of spindle vibration frequency on the cutter wear degree of depth in milling cutter forced vibration; Illustrated the impact mechanism of spindle vibration amplitude on cutter wear width unevenness in milling cutter forced vibration; The impact mechanism of spindle vibration amplitude on milling cutter front and rear knife face abration position unevenness in milling cutter forced vibration; The impact mechanism of spindle vibration frequency on cutter wear degree of depth unevenness in milling cutter forced vibration; Having disclosed milling cutter forced vibration is due to the contact relation that has changed milling cutter and workpiece, causes the stress intensity of milling cutter and distribution to change, and wearing and tearing width, wearing depth, the abration position of milling cutter tooth are changed; Because the cutter tooth of milling cutter distributes, cause milling cutter vibration to have phase differential, make milling cutter body vibration be applied to the vibration displacement of local each cutter tooth of milling cutter different, therefore, form the inhomogeneous of the multiple tooth wearing and tearing of milling cutter.

4. a kind of high-speed milling cutter method for designing that suppresses cutter tooth forced vibration wearing and tearing unevenness according to claim 3, is characterized in that: the multiple tooth forced vibration Wear evaluation of milling cutter method;

Tool wear degree of irregularity can cause cutting stability variation, and machined surface quality changes, and therefore, it is very important that milling cutter uneven wear is passed judgment on; ; From the friction pair of milling cutter and workpiece, start with, analyze cutter wear character, wear area, the degree of wear, propose the criterion of milling cutter uneven wear, define goal of regulation and control;

First, by forced vibration wear test result, calculate: the abration position unevenness of milling cutter rake face, rear knife face, cutting edge three places wearing and tearing, wearing and tearing width unevenness, wearing depth unevenness, contrast obtains three kinds of unevenness maximal values, i.e. l _{(AD) max}, b _{(AD) max}, h _{(AD) max}all occur in which position; Contact stress between milling cutter and friction of workpiece pair closes:

In formula: σ is milling cutter and the secondary compressive stress, F of contacting of friction of workpiece _cfor cutting force, S is cutter wear area, a _efor milling width, k, p, q, r, m are respectively coefficient, by different materials, are determined;

The abration position of milling cutter has directly determined the abrasive nature of milling cutter, while considering milling cutter uneven wear, same the different cutter tooth abration positions of milling cutter and wear area are determined to the friction pair character that milling cutter and workpiece form jointly, abrasive nature under each wear area is thought same, therefore, whether whether the wear area that can produce according to two cutter tooth wearing and tearing exist the character of relation of inclusion decision content cutter tooth wearing and tearing consistent, that is:

in formula: i is the less i tooth of wear area, j is the larger j tooth of wear area; If formula 18 is false, the abration position of two cutters tooth is inhomogeneous, now should first adjust parameter, makes abration position identical;

If formula 18 is set up, analyze friction pair type; When contact stress is greater than yield strength [σ _s] time, milling cutter weares and teares, and sets up thus wear area criterion:

This formula has reflected the type of two kinds of friction pairs; Work as S ₁during establishment, friction pair contact area is little, and wear area can change along with the continuation of working angles under the condition of vibration; Work as S ₂during establishment, friction pair contact area is large, and wearing depth can change along with the continuation of working angles under the condition of vibration;

Work as S _i, S _jwhen different, belong to S ₁or S ₂time, the friction pair type of two cutters tooth is different, now should first adjust parameter, makes friction pair type identical;

Work as S _i, S _jall belong to S ₁or S ₂time, consider the cutter wear degree of depth; And the initial stage of wearing and tearing in milling cutter forced vibration, the tool surface of new sharpening is coarse, and microfissure, oxidation or decarburized layer defect, therefore the time of this one-phase is shorter, wearing and tearing are very fast, on this basis, consider whether the increase of wearing depth can cause the variation of wear area S, and then affect the stability of friction pair contact condition; Therefore, the degree of depth of milling cutter forced vibration wearing and tearing should meet:

In formula: wearing and tearing depth capacity h _maxbe 0.05～0.10mm, the size of wear extent is relevant with grinding quality.

5. a kind of design method for milling cutter that suppresses cutter tooth forced vibration wearing and tearing unevenness according to claim 4, is characterized in that: the control method of milling cutter forced vibration uneven wear

Utilize the impact of the above-mentioned single factor analyzing on milling cutter forced vibration wearing and tearing and wearing and tearing unevenness, control single factor, realize the control to face milling cutters forced vibration wearing and tearing and wearing and tearing unevenness; For Tool Design provides design variable; Because milling cutter exists phasing degree

i be cutter tooth code name from 1 to Z, the amplitude of each cutter tooth of milling cutter is different, i the cutter tooth of take is benchmark while contacting with workpiece, the speed of mainshaft is n, if master blade amplitude is A _i(t), so adjacent i+1 tooth amplitude is:

In milling process, under centrifugal force and cutting force excitation, when cutting force becomes large, cutter can produce strong forced vibration, and meanwhile, workpiece also exists vibration in milling process;

Setting milling cutter rotating speed is n, and the number of teeth is Z, and vibration frequency is f ₁; Feed-speed is V _f, vibration frequency is f ₂, therefore, wait the rotation cutting frequency f of tooth pitch milling cutter tooth ₃, the spacing frequency that adjacent two cutters tooth participate in cutting is:

f ₃=nZ （20）

Because cutter and Workpiece vibration all present periodically, when milling cutter vibration frequency is f ₁rotation cutting frequency f with milling cutter tooth ₃when identical, the forced vibration of milling cutter wearing and tearing are uniform wear; Work as f ₁≠ f ₃time, the amplitude of each cutter tooth of milling cutter milling cutter when cutting is all different, causes milling cutter to produce forced vibration uneven wear;

Milling cutter vibration frequency f _idetermined the degree of depth of milling cutter vibration abrasion, and milling cutter vibration frequency f _ibe to be n by milling cutter rotating speed, the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃determine, therefore, milling cutter rotating speed is n, and the number of teeth is Z, and the rotation of milling cutter tooth cutting frequency f ₃it is the basic controlling variable of milling cutter forced vibration wearing and tearing;

Cutter cutting vibration behavioral parameters and milling cutter tooth abrasional behavior parameter are decomposed, cutting parameter design variable is carried out to descending sequence, i.e. design sequence to the influence degree of milling cutter tooth forced vibration wearing and tearing; With cutter parameters design variable, to cutting parameter, out of contior forced vibration wearing and tearing compensate design.

6. a kind of design method for milling cutter that suppresses cutter tooth forced vibration wearing and tearing unevenness according to claim 4, is characterized in that: milling cutter construction design

First, by setting up the milling cutter model of the different numbers of teeth, pass through finite element modal analysis, study the vibration characteristics of its structure, analyze the impact of the different numbers of teeth on milling vibration, for reducing vibration cutting, improve crudy provide with reference to and foundation, by UG set up diameter 63mm, the different numbers of teeth etc. tooth milling cutter solid model, be respectively the tooth pitches such as 4 teeth, the 4 teeth tooth pitch milling cutter such as not;

Ansys boundary condition definition: cutter can not can not have rotation vertically and radially axially and radially play occurring or beating, thus all degree of freedom that just must restriction handle of a knife, the constraint condition of Here it is cutter; According to the actual clamping situation of milling cutter, the axial displacement of constraint milling cutter shank, shank cylindrical radial and tangential displacement, when analysis is not subject to load, different number of teeth milling cutter 1～6 rank natural frequency is not as shown in table 4;

The different number of teeth milling cutter of table 4 natural frequency (unit: Hz)

As known from Table 4,4 teeth do not wait six first order mode ratios of tooth milling cutter to wait tooth milling cutter little, and under the identical number of teeth, natural frequency is very approaching, is mode compact district; It is larger that natural frequency differs; Second order and three rank natural frequencys differ greatly, and for mode rarefaction, wait tooth pitch, and the variation tendency of its natural frequency is all descending variation; The tooth pitch of this explanation cutter has impact to the natural frequency of cutter, when the natural frequency of cutter approaches the excited frequency of system of processing, just likely causes the resonance of cutter, the generation of flutter, and multitoothed cutter easily vibrates when high-speed milling.

7. a kind of design method for milling cutter that suppresses cutter tooth forced vibration wearing and tearing unevenness according to claim 6, is characterized in that: to milling cutter construction, experimental verification is carried out in design

For further verifying above-mentioned analysis result, adopt four teeth of development not wait tooth milling cutter: diameter is 63mm, tooth pitch is respectively 88,89,91,92, carry out No. 45 steel experiments of high-speed milling with the flank of tooth milling cutter such as diameter 63mm tetra-teeth, test its vibration characteristics: experiment lathe, workpiece, cutter and experiment parameter are as shown in table 5:

Table 5 confirmatory experiment parameter

Utilize VDL-1000E lathe, to spindle vibration, cutter tooth, wearing and tearing are measured, and measurement result is as shown in table 6, wherein: X be line-spacing direction, Y for axially, Z is direction of feed:

The teeth such as table 6 four teeth vibrate and the contrast of wearing and tearing unevenness result with not waiting experiment of tooth milling cutter

When the variation of cutter parameters and cutting parameter, the forced vibration of milling cutter is occurring to change, and wherein, cutter tooth, cutting-tool angle, tooth pitch are the design variables of cutter; Determine the vibration of this cutter, also be the controlling factor that causes milling cutter forced vibration wearing and tearing to change simultaneously, from experimental result, can find out, its forced vibration and forced vibration wearing and tearing and surface quality consistance are all improved, four teeth of designing do not wait tooth milling cutter: structure of the cutter body is taper cutter hub, and cutter hub material is 40Cr, and trip bolt adopts fine thread screw, trip bolt material is 35CrMo, and blade is TiN coated cemented carbide insert; Milling cutter diameter d is 63mm, and the cutter amount of overhanging L is 36mm, and the cutter number of teeth is 4 teeth, and tool cutting edge angle is 45 °; Blade is installed anterior angle γ ₀be 2 °, cutter tooth distributes to adopt and does not wait tooth to distribute, and cutter tooth progressive error is 5 °, and diameter is 63mm, and between cog angle is 88,89,91,92; This milling cutter has changed the vibration frequency of milling cutter tooth by changing cutter tooth distribution, reduced the wearing and tearing of milling cutter tooth; Simultaneously, the adjustment to phasing degree apart from distribution by this cutter teeth, make the milling frequency of milling cutter consistent with the vibration frequency of milling cutter, reduced the unevenness of milling cutter forced vibration wearing and tearing, therefore can to milling cutter, design by changing cutter parameters, the forced vibration of milling cutter and forced vibration wearing and tearing and wearing and tearing unevenness (life-span) are all produced effect, again by changing cutting parameter, when reaching the milling efficiency of processing request, do not change character and the rate of depreciation of wearing and tearing, finally make milling cutter realize the target of high life.

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