CN103586738B - Finish-milling based on Integral impeller blade shape becomes feeding speed optimization method - Google Patents

Abstract

The invention discloses a kind of finish-milling based on Integral impeller blade shape and become feeding speed optimization method, comprising: according to the geometry of Integral impeller blade, generating based on Probe-radius is R _tthe accurately machined Path source file of ball head knife blade, this Path source file records the generating tool axis vector of cutter location coordinate under Cutter coordinate system and correspondence thereof, import the individual blade model of impeller, gone out the intersection of runner and blade to the Distance Judgment of impeller central by the point on blade, extract intersection and according to action such as grade, this intersection be separated into W point, and this W some composition point set U, proportion omegab is accelerated to end depth in the top of setting blade, the Path source file generated in step (1) is read line by line successively and resolved, to extract the cutter location information of whole cutting paths of the Path source file generated in (1).The present invention can overcome the technical problem that the working (machining) efficiency existed in existing method is low, crudy is poor and tool wear is serious.

Description

Finish-milling based on Integral impeller blade shape becomes feeding speed optimization method

Technical field

The invention belongs to multi-axis linkage numerical control field of machining, more specifically, relate to a kind of finish-milling based on Integral impeller blade shape and become feeding speed optimization method.

Background technology

Integral wheel mainly adopts multi-axis NC machining manufacture as high-performance complex curved surface parts, the complexity of its geometry and curve form, this kind of part is caused to adopt the link such as dedicated tool, process optimization, numerical control programming and machine tool motion planning during Multi-axis Machining very complicated, seriously constrain multiaxis NC maching quality and efficiency, and the cost of great number.Cause the working ability of these Key basic parts can not meet national Important Project demand far away.

At present, at high-performance complex curve multi-axis linkage manufacture field, the part crudy caused due to the problem of the aspects such as cutter, technique, programming and machine dynamic characteristics is poor, the low critical bottleneck having become its processing effect of restriction of working (machining) efficiency, simultaneously these problems also cause process stability and integrality bad, cause the processing usefulness of multi-shaft interlocked lathe to be not fully exerted far away.

Summary of the invention

For above defect or the Improvement requirement of prior art, the invention provides a kind of finish-milling based on Integral impeller blade shape and become feeding speed optimization method, its object is to, according to geometry and the curve form feature of impeller individual blade, the feeding of finish-milling processing Path is optimized, thus overcomes the technical problem that the working (machining) efficiency existed in existing method is low, crudy is poor and tool wear is serious.

For achieving the above object, according to one aspect of the present invention, provide a kind of finish-milling based on Integral impeller blade shape and become feeding speed optimization method, comprise the following steps:

(1) according to the geometry of Integral impeller blade, generating based on Probe-radius is R _tthe accurately machined Path source file of ball head knife blade, this Path source file records the cutter location coordinate x under Cutter coordinate system, y, z, and the generating tool axis vector i of correspondence, j, k;

(2) the Path source file generated in step (1) is read line by line successively and resolved, to extract the cutter location information of whole cutting paths of the Path source file generated in (1), and obtain the quantity N of all cutting paths in Path source file;

(3) feed speed for each cutting path in all N bar cutting paths is optimized; Be specially:

(3-1) read each cutter location information in each cutting path, comprise cutter location coordinate [x, y, z] ^q, wherein q represents q cutter location of this article of cutting path, and the generating tool axis vector that q cutter location is corresponding wherein T represents transposed matrix;

(3-2) vane thickness at the cutter location correspondence cutter-contact point place on each cutting path and outstanding length is calculated according to cutter location information;

(3-3) obtain cutter location based on the feed speed after the optimization of corresponding cutter-contact point place vane thickness, and obtain the final feeding of this cutter location according to the outstanding length at the corresponding cutter-contact point place of this feed speed and this cutter location, specifically comprise following sub-step:

(3-3-1) the feed speed F of the cutter location that cutter-contact point is corresponding in the fillet district divided is obtained _1max, and the feed speed F of cutter location corresponding to smooth area maximum gauge place _2max, obtain all the other one-tenth-value thickness 1/10s δ by linear interpolation method _q1, δ _q2δ _qs, δ _p1, δ _p2δ _prthe feed speed of the cutter location that place is corresponding, and by these feed speeds obtain each cutter location in this cutting path optimize based on corresponding cutter-contact point place vane thickness after feed speed F _q0;

(3-3-2) the feed speed F after optimizing based on corresponding cutter-contact point place vane thickness according to each cutter location _q0with the outstanding long l at the corresponding cutter-contact point place of this cutter location _qobtain the final feeding F of this cutter location _q, be specially:

Fq=η·F _q0

Wherein η is proportionality coefficient, and

$\mathrm{\η}=\frac{(l_{\max }-l_q)\mathrm{\ω}+l_q}{l_{\max }}$

Wherein ω represents that ratio is accelerated to end depth in the top of blade, and has ω >=1;

(3-3-3) (3-3-2) step is repeated, until obtain the feed speed of all cutter locations in this cutting path.

Preferably, after method of the present invention is also included in step (1), import the individual blade model of impeller, gone out the intersection of runner and blade by the point on blade to the Distance Judgment of impeller central, extract intersection and according to action such as grade, this intersection be separated into W point, and this W some composition point set U.

Preferably, step (3-2) comprises following sub-step:

(3-2-1) calculate the cutter-contact point that in this cutting path, each cutter location is corresponding, be specially: according to the cutter location [x, y, z] in (3-1) ^qand generating tool axis vector calculate corresponding cutter heart point coordinates then by cutter heart point be projected on spoon of blade, can cutter-contact point be obtained

(3-2-2) vane thickness at the corresponding cutter-contact point place of each cutter location in this cutting path is calculated; Be specially: four the key point K first being found out this cutter-contact point collection by the distance between the adjacent cutter-contact point of calculating two ₁, K ₂, K ₃, K ₄, wherein K ₁with K ₄between line and K ₂with K ₄between line the closed curve that cutter-contact point is formed is divided into four parts, the fillet district at two ends and the smooth area of centre, then, calculate cutter-contact point K ₁with K ₄, K ₂with K ₃between distance be respectively d _k1, d _k2, then cutter-contact point K ₁with K ₄the thickness of place's blade is δ _k1=d _k1, cutter-contact point K ₂with K ₃the thickness of place's blade is δ _k2=d _k2, K ₁with K ₂between cutter-contact point be Q ₁, Q ₂q _s, wherein s is K ₁with K ₂between the sum of cutter-contact point, K ₃with K ₄between cutter-contact point be P ₁, P ₂p _r, wherein r is K ₃with K ₄between the sum of cutter-contact point;

(3-2-3) blade calculating the corresponding cutter-contact point place of each cutter location in this cutting path is outstanding long, is specially calculating cutter-contact point to the beeline l of point set U _min, and using this distance as blade at the outstanding long value l that this cutter-contact point is corresponding _q, and obtain the maximum of all cutter-contact points during the corresponding cutter-contact point place of cutter location in calculating first cutting path outstanding long and hang long l _max.

Preferably, if s=r, calculate cutter-contact point Q ₁to cutter-contact point P ₁distance d ₁, cutter-contact point Q ₂to cutter-contact point P ₂distance d ₂cutter-contact point Q _sto cutter-contact point P _sdistance d _s; Then cutter-contact point Q ₁with P ₁the thickness δ of place's blade _q1, δ _p1be equal to d ₁, cutter-contact point Q ₂with P ₂the thickness δ of place's blade _q2, δ _p2be equal to d ₂cutter-contact point Q _swith P _sthe thickness δ of place's blade _qs, δ _psbe equal to d _s, more each thickness δ simultaneously _q1, δ _q2δ _qs, δ _p1, δ _p2δ _pssize, to obtain the maximum gauge δ of all cutter locations corresponding cutter-contact point places blade in this cutting path _max;

If s ≠ r, pass through K ₁with K ₂between cutter-contact point Q ₁, Q ₂q _sstructure B-spline Curve, and by wait action method on this curve discrete go out r put Q ' ₁q ' ₂... Q ' _rand then calculation level Q ' ₁to cutter-contact point P ₁distance d ' ₁, some Q ' ₂to cutter-contact point P ₂distance d ' ₂point Q ' _rto cutter-contact point P _rdistance d ' _rblade can be obtained at K ₃with K ₄between cutter-contact point P ₁, P ₂p _rthe thickness δ of corresponding position _p1=d ' ₁, δ _p2=d ' ₂δ _pr=d ' _r; Finally by linear interpolation, obtain K ₁with K ₂between cutter-contact point Q ₁, Q ₂q _sthe thickness δ of place's blade _q1, δ _q2δ _qs; More each thickness δ simultaneously _q1, δ _q2δ _qS, δ _p1, δ _p2δ _prsize, to obtain the maximum gauge δ of all cutter locations corresponding cutter-contact point places blade in this cutting path _max.

Preferably, key point K ₁with K ₄between fillet district and K ₂, k ₃between fillet district in the feeding of cutter location corresponding to cutter-contact point be F _1max, the most thickness of smooth area is δ _maxthe feeding of corresponding cutter location is F _2max;

K ₁with K ₂between the cutter-contact point Q of smooth area ₁, Q ₂q _sthe feed speed of corresponding cutter location is obtained by following linear difference formula:

${F_Q}_t=\frac{({\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{\mathrm{Qt}})(F_{2\max }-F_{1\max })}{{\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{k1}}$

Wherein t ∈ N and 1≤t≤s;

K ₃with K ₄between the cutter-contact point P of smooth area ₁, P ₂p _rthe feed speed of corresponding cutter location is obtained by following linear difference formula:

$F_{\mathrm{Pw}}=\frac{({\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{\mathrm{Pw}})(F_{2\max }-F_{1\max })}{{\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{k1}}$

Wherein w ∈ N and 1≤w≤r.

Preferably, when arrive distance much smaller than arrive distance time, for key point.

In general, the above technical scheme conceived by the present invention compared with prior art, can obtain following beneficial effect:

(1) working (machining) efficiency of the present invention is high: owing to have employed according to the outstanding long method optimizing feed speed, fast near Integral impeller blade tip portion feed speed, fast near runner section feeding, while ensureing machined surface quality, also improve overall feed speed, therefore the present invention can realize high working (machining) efficiency.

(2) crudy of the present invention is good: owing to have employed based on Integral impeller blade thickness and the outstanding long feed speed optimized, thus taken into full account outstanding greatly long feature---the weak rigidity of processing of Integral impeller blade thin-walled, thus the chatter mark that causes because the weak rigidity of processing easily produces flutter can be reduced, thus improve machined surface quality.

(3) the present invention reduces tool wear: owing to have employed based on Integral impeller blade thickness and the outstanding long feed speed optimized, take into full account outstanding greatly long feature---the weak rigidity of processing of Integral impeller blade thin-walled, thus can reduce because the flutter that easily produces of weak rigidity of processing, optimize the stressing conditions of cutter in process, thus reduce tool wear, extend cutting-tool's used life.

(4) present invention reduces the cost of integral wheel processing: owing to improve working (machining) efficiency, extend the life-span of cutter, reduce time cost and the cost of charp tool, thus reduce processing cost.

(5) optimization range of the present invention is wide: from integral wheel textural classification, no matter be that axial impeller or receded disk impeller can use the inventive method to carry out feeding optimization, from the material of integral wheel, be titanium alloy, high temperature or aluminum alloy impeller be all use the inventive method to carry out feeding optimization.

Accompanying drawing explanation

Fig. 1 calculates the corresponding cutter-contact point place vane thickness of cutter location and outstanding long schematic diagram.

Fig. 2 is the flow chart of the finish-milling change feeding speed optimization method that the present invention is based on Integral impeller blade shape.

Detailed description of the invention

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.In addition, if below in described each embodiment of the present invention involved technical characteristic do not form conflict each other and just can mutually combine.

The step that impeller blade fine finishining is the most key in Impeller Machining as a whole, be also reaction China aviation Impeller Machining backward in technique in external Impeller Machining technology the most outstanding a bit.For the processing of blade finish-milling, extension and improvement can be carried out from following two aspects: the planning of Path, the choosing of cutting parameter.The present invention is directed to feed speed in cutting parameter to be optimized to improve accurately machined quality and efficiency.

Integral Thought of the present invention is by being optimized blade finish-milling processing technology path based on Integral impeller blade shape, specifically consider the thickness of each cutter location corresponding cutter-contact point place blade and outstanding length, by a scale factor, the feeding of this cutter location is optimized.

As shown in Figure 1, the finish-milling that the present invention is based on Integral impeller blade shape becomes feeding speed optimization method and comprises the following steps:

(1) according to the geometry of Integral impeller blade, generating based on Probe-radius is R _tthe accurately machined Path source file of ball head knife blade; Specifically, the fine finishining track having planned Integral impeller blade in MAX-PAC software with ball head knife is required according to the geometry of Integral impeller blade and processing technology, and the Path source file describing cutter location coordinate and generating tool axis vector is derived according to this machining locus, suffix is called .cls, and its row format is:

FEDRAT/F

GOTO/x，y，z,i,j,k

FEDRAT/F represents that ensuing one or more cutter location feed speed is first three items data x after F, GOTO/ indications, and y, z are the cutter location coordinate under Cutter coordinate system, and rear three item numbers are the generating tool axis vector of its correspondence according to i, j, k;

(2) in UG software, importing the individual blade model of impeller, gone out the intersection of runner and blade by the point on blade to the Distance Judgment of impeller central, extracting intersection also according to waiting action that this intersection is separated into W point, and this W is put and form point set U; Specifically, W is greater than the cutter location quantity in the Path source file obtained in step (1) in every bar cutting path;

(3) the Path source file generated in step (1) is read line by line successively and resolved, to extract the cutter location information of whole cutting paths of the Path source file generated in (1), and obtain the quantity N of all cutting paths in Path source file;

(4) feed speed for each cutting path in all N bar cutting paths is optimized;

Be specially:

(4-1) read each cutter location information in each cutting path, comprise the first three items parameter [x, y, z] in GOTO/ statement ^q, wherein q represents q cutter location of this article of cutting path, and rear three item number certificates: the generating tool axis vector that namely q cutter location is corresponding , wherein T represents transposed matrix;

(4-2) vane thickness at the cutter location correspondence cutter-contact point place on each cutting path and outstanding length is calculated according to cutter location information; Specifically comprise following sub-step:

(4-2-1) cutter-contact point that in this cutting path, each cutter location is corresponding is calculated;

Specifically, according to the cutter location [x, y, z] in (4-1) ^qand generating tool axis vector calculate corresponding cutter heart point coordinates computing formula is as follows:

$x_{\mathrm{dx}}^q=x_{\mathrm{dw}}^q+R_T\·i_q;$

$y_{\mathrm{dx}}^q=y_{\mathrm{dw}}^q+R_T\·j_q;$

$z_{\mathrm{dx}}^q=z_{\mathrm{dw}}^q+R_T\·k_q;$

Then by cutter heart point be projected on spoon of blade, can cutter-contact point be obtained in above formula, R _tfor the Probe-radius of ball head knife.

(4-2-2) vane thickness at the corresponding cutter-contact point place of each cutter location in this cutting path is calculated;

Specifically, first found out four key points of this cutter-contact point collection by the distance between the adjacent cutter-contact point of calculating two, namely when arrive distance much smaller than arrive distance time, assert be key point K, use method of the same race to find out four key point K ₁, K ₂, K ₃, K ₄; As shown in Figure 1, K ₁with K ₄between line and K ₂with K ₄between line the closed curve that cutter-contact point is formed is divided into four parts: the fillet district at two ends and the smooth area of centre;

Then, cutter-contact point K is calculated ₁with K ₄, K ₂with K ₃between distance be respectively d _k1, d _k2, then cutter-contact point K ₁with K ₄the thickness of place's blade is δ _k1=d _k1, cutter-contact point K ₂with K ₃the thickness of place's blade is δ _k2=d _k2;

K ₁with K ₂between cutter-contact point be Q ₁, Q ₂q _s, wherein s is K ₁with K ₂between the sum of cutter-contact point, K ₃with K ₄between cutter-contact point be P ₁, P ₂p _r, wherein r is K ₃with K ₄between the sum of cutter-contact point;

If s=r, calculate cutter-contact point Q ₁to cutter-contact point P ₁distance d ₁, cutter-contact point Q ₂to cutter-contact point P ₂distance d ₂cutter-contact point Q _sto cutter-contact point P _sdistance d _s; Then cutter-contact point Q ₁with P ₁the thickness δ of place's blade _q1, δ _p1be equal to d ₁, cutter-contact point Q ₂with P ₂the thickness δ of place's blade _q2, δ _p2be equal to d ₂cutter-contact point Q _swith P _sthe thickness δ of place's blade _qs, δ _psbe equal to d _s, more each thickness δ simultaneously _q1, δ _q2δ _qs, Q _p1, δ _p2δ _pssize, to obtain the maximum gauge δ of all cutter locations corresponding cutter-contact point places blade in this cutting path _max;

If s ≠ r, pass through K ₁with K ₂between cutter-contact point Q ₁, Q ₂q _sstructure B-spline Curve, and by wait action method on this curve discrete go out r put Q ' ₁, Q ' ₂q ' _r, and then calculation level Q ' ₁to cutter-contact point P ₁distance d ' ₁, some Q ' ₂to cutter-contact point P ₂distance d ' ₂point Q ' _rto cutter-contact point P _rdistance d ' _r, blade can be obtained at K ₃with K ₄between cutter-contact point P ₁, P ₂p _rthe thickness δ of corresponding position _p1=d ' ₁, δ _p2=d ' ₂δ _pr=d ' _r; Finally by linear interpolation, obtain K ₁with K ₂between cutter-contact point Q ₁, Q ₂q _sthe thickness δ of place's blade _q1, δ _q2δ _qs; More each thickness δ simultaneously _q1, δ _q2δ _qs, δ _p1, δ _p2δ _prsize, to obtain the maximum gauge δ of all cutter locations corresponding cutter-contact point places blade in this cutting path _max.

(4-2-3) blade calculating the corresponding cutter-contact point place of each cutter location in this cutting path is outstanding long;

Specifically, as shown in Figure 1, cutter-contact point is calculated to the beeline l of point set U _min, and using this distance as blade at the outstanding long value l that this cutter-contact point is corresponding _q, and obtain the maximum of all cutter-contact points during the corresponding cutter-contact point place of cutter location in calculating first cutting path outstanding long and hang long l _max;

(4-3) obtain cutter location based on the feed speed after the optimization of corresponding cutter-contact point place vane thickness, and obtain the final feeding of this cutter location according to the outstanding length at the corresponding cutter-contact point place of this feed speed and this cutter location;

Specifically,

(4-3-1) in the fillet district first divided in obtaining step (4-2-2), cutter-contact point (comprises K ₁, K ₂, K ₃, K ₄) the feed speed F of corresponding cutter location _1max, and (thickness is δ at smooth area maximum gauge place _max) the feed speed F of corresponding cutter location _2max, obtain all the other one-tenth-value thickness 1/10s δ by linear interpolation method _q1, δ _q2δ _qs, δ _p1, δ _p2δ _prthe feed speed of the cutter location that place is corresponding;

Specifically, K ₁with K ₄between fillet district (comprise K ₁, K ₄) and K ₂, K ₃between fillet district (comprise K ₂, K ₃) in the feeding of cutter location corresponding to cutter-contact point be F _1max, (thickness is δ at smooth area maximum gauge place _max) feeding of corresponding cutter location is F _2max;

K ₁with K ₂between the cutter-contact point Q of smooth area ₁, Q ₂q _sthe feed speed of corresponding cutter location is obtained by following linear difference formula:

${F_Q}_t=\frac{({\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{\mathrm{Qt}})(F_{2\max }-F_{1\max })}{{\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{k1}}$

Wherein t ∈ N and 1≤t≤s;

K ₃with K ₄between the cutter-contact point P of smooth area ₁, P ₂p _rthe feed speed of corresponding cutter location is obtained by following linear difference formula:

$F_{\mathrm{Pw}}=\frac{({\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{\mathrm{Pw}})(F_{2\max }-F_{1\max })}{{\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{k1}}$

Wherein w ∈ N and 1≤w≤r;

Resulting in each cutter location in this cutting path optimize based on corresponding cutter-contact point place vane thickness after feed speed F _q0.

(4-3-2) the feed speed F after optimizing based on corresponding cutter-contact point place vane thickness according to each cutter location _q0with the outstanding long l at the corresponding cutter-contact point place of this cutter location _qobtain the final feeding F of this cutter location _q, be specially:

F _q=η·F _q0

Wherein η is proportionality coefficient, and

$\mathrm{\η}=\frac{(l_{\max }-l_q)\mathrm{\ω}+l_q}{l_{\max }}$

Wherein ω represents that ratio is accelerated to end depth in the top of blade, and has ω >=1;

(4-3-3) (4-3-2) step is repeated, until obtain the feed speed of all cutter locations in this cutting path.

Those skilled in the art will readily understand; the foregoing is only preferred embodiment of the present invention; not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (5)

1. the finish-milling based on Integral impeller blade shape becomes a feeding speed optimization method, it is characterized in that, comprises the following steps:

(1) according to the geometry of Integral impeller blade, generating based on Probe-radius is R _tthe accurately machined Path source file of ball head knife blade, this Path source file records the cutter location coordinate x under Cutter coordinate system, y, z, and the generating tool axis vector i of correspondence, j, k;

(2) the Path source file generated in step (1) is read line by line successively and resolved, to extract the cutter location information of whole cutting paths of the Path source file generated in (1), and obtain the quantity N of all cutting paths in Path source file;

(3) feed speed for each cutting path in all N bar cutting paths is optimized; Be specially:

(3-1) read each cutter location information in each cutting path, comprise cutter location coordinate [x, y, z] ^q, wherein q represents q cutter location of this article of cutting path, and the generating tool axis vector that q cutter location is corresponding ${\left[\begin{array}{ccc}i& j& k\end{array}\right]}_q^T,$ Wherein T represents transposed matrix;

(3-2) vane thickness at the cutter location correspondence cutter-contact point place on each cutting path and outstanding length is calculated according to cutter location information; This step comprises following sub-step:

(3-2-1) calculate the cutter-contact point that in this cutting path, each cutter location is corresponding, be specially: according to the cutter location [x, y, z] in (3-1) ^qand generating tool axis vector ${\left[\begin{array}{ccc}i& j& k\end{array}\right]}_q^T$ Calculate corresponding cutter heart point coordinates then by cutter heart point be projected on spoon of blade, can cutter-contact point be obtained ${[x,y,z]}_{\mathrm{dc}}^q;$

(3-2-2) vane thickness at the corresponding cutter-contact point place of each cutter location in this cutting path is calculated; Be specially: four the key point K first being found out this cutter-contact point collection by the distance between the adjacent cutter-contact point of calculating two ₁, K ₂, K ₃, K ₄, wherein K ₁with K ₄between line and K ₂with K ₄between line the closed curve that cutter-contact point is formed is divided into four parts, the fillet district at two ends and the smooth area of centre, then, calculate cutter-contact point K ₁with K ₄, K ₂with K ₃between distance be respectively d _k1, d _k2, then cutter-contact point K ₁with K ₄the thickness of place's blade is δ _k1=d _k1, cutter-contact point K ₂with K ₃the thickness of place's blade is δ _k2=d _k2, K ₁with K ₂between cutter-contact point be Q ₁, Q ₂q _s, wherein s is K ₁with K ₂between the sum of cutter-contact point, K ₃with K ₄between cutter-contact point be P ₁, P ₂p _r, wherein r is K ₃with K ₄between the sum of cutter-contact point;

(3-2-3) blade calculating the corresponding cutter-contact point place of each cutter location in this cutting path is outstanding long, is specially calculating cutter-contact point to the beeline l of point set U _min, and using this distance as blade at the outstanding long value l that this cutter-contact point is corresponding _q, and obtain the maximum of all cutter-contact points during the corresponding cutter-contact point place of cutter location in calculating first cutting path outstanding long and hang long l _max;

(3-3) obtain cutter location based on the feed speed after the optimization of corresponding cutter-contact point place vane thickness, and obtain the final feed speed of this cutter location according to the outstanding length at the corresponding cutter-contact point place of this feed speed and this cutter location, specifically comprise following sub-step:

(3-3-1) the feed speed F of the cutter location that cutter-contact point is corresponding in the fillet district divided is obtained _1max, and the feed speed F of cutter location corresponding to smooth area maximum gauge place _2max, obtain all the other one-tenth-value thickness 1/10s δ by linear interpolation method _q1, δ _q2δ _qs, δ _p1, δ _p2δ _prthe feed speed of the cutter location that place is corresponding, and by these feed speeds obtain each cutter location in this cutting path optimize based on corresponding cutter-contact point place vane thickness after feed speed F _q0;

(3-3-2) the feed speed F after optimizing based on corresponding cutter-contact point place vane thickness according to each cutter location _q0with the outstanding long l at the corresponding cutter-contact point place of this cutter location _qobtain the final feeding F of this cutter location _q, be specially:

F _q＝η·F _q0

Wherein η is proportionality coefficient, and

$\mathrm{\η}=\frac{(l_{\max }-l_q)\mathrm{\ω}+l_q}{l_{\max }}$

Wherein ω represents that ratio is accelerated to end depth in the top of blade, and has ω >=1;

(3-3-3) (3-3-2) step is repeated, until obtain the feed speed of all cutter locations in this cutting path.

2. finish-milling according to claim 1 becomes feeding speed optimization method, it is characterized in that, after being also included in step (1), import the individual blade model of impeller, gone out the intersection of runner and blade to the Distance Judgment of impeller central by the point on blade, extract intersection and according to action such as grade, this intersection be separated into W point, and this W some composition point set U.

3. finish-milling according to claim 2 becomes feeding speed optimization method, it is characterized in that,

If s=r, calculate cutter-contact point Q ₁to cutter-contact point P ₁distance d ₁, cutter-contact point Q ₂to cutter-contact point P ₂distance d ₂cutter-contact point Q _sto cutter-contact point P _sdistance d _s; Then cutter-contact point Q ₁with P ₁the thickness δ of place's blade _q1, δ _p1be equal to d ₁, cutter-contact point Q ₂with P ₂the thickness δ of place's blade _q2, δ _p2be equal to d ₂cutter-contact point Q _swith P _sthe thickness δ of place's blade _qs, δ _psbe equal to d _s, more each thickness δ simultaneously _q1, δ _q2δ _qs, δ _p1, δ _p2δ _pssize, to obtain the maximum gauge δ of all cutter locations corresponding cutter-contact point places blade in this cutting path _max;

If s ≠ r, pass through K ₁with K ₂between cutter-contact point Q ₁, Q ₂q _sstructure B-spline Curve, and by wait action method on this curve discrete go out r put Q ' ₁, Q ' ₂q ' _r, and then calculation level Q ' ₁to cutter-contact point P ₁distance d ' ₁, some Q ' ₂to cutter-contact point P ₂distance d ' ₂point Q ' _rto cutter-contact point P _rdistance d ' _r, blade can be obtained at K ₃with K ₄between cutter-contact point P ₁, P ₂p _rthe thickness δ of corresponding position _p1=d ' ₁, δ _p2=d ' ₂δ _pr=d ' _r; Finally by linear interpolation, obtain K ₁with K ₂between cutter-contact point Q ₁, Q ₂q _sthe thickness δ of place's blade _q1, δ _q2δ _qs; More each thickness δ simultaneously _q1, δ _q2δ _qs, δ _p1, δ _p2δ _prsize, to obtain the maximum gauge δ of all cutter locations corresponding cutter-contact point places blade in this cutting path _max.

4. finish-milling according to claim 2 becomes feeding speed optimization method, it is characterized in that,

Key point K ₁with K ₄between fillet district and K ₂, K ₃between fillet district in the feeding of cutter location corresponding to cutter-contact point be F _1max, the most thickness of smooth area is δ _maxthe feeding of corresponding cutter location is F _2max;

K ₁with K ₂between the cutter-contact point Q of smooth area ₁, Q ₂q _sthe feed speed of corresponding cutter location is obtained by following linear difference formula:

$F_{\mathrm{Qt}}=\frac{({\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{\mathrm{Qt}})(F_{2\max }-F_{1\max })}{{\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{k1}}$

Wherein t ∈ N and 1≤t≤s;

K ₃with K ₄between the cutter-contact point P of smooth area ₁, P ₂p _rthe feed speed of corresponding cutter location is obtained by following linear difference formula:

$F_{\mathrm{Pw}}=\frac{({\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{\mathrm{Pw}})(F_{2\max }-F_{1\max })}{{\mathrm{\δ}}_{\max }-{\mathrm{\δ}}_{k1}})$

Wherein w ∈ N and 1≤w≤r.

5. finish-milling according to claim 4 becomes feeding speed optimization method, it is characterized in that, when arrive distance much smaller than arrive distance time, for key point.