CN102728880A - Cutter shaft control method of leading line yielding track in blade helical milling process - Google Patents

Abstract

The invention provides a cutter shaft control method of a leading line yielding track in a blade helical milling process, comprising the following steps of: firstly, configuring a blade cylinder auxiliary face; secondly, taking a containing cylindrical face as an auxiliary face and constructing a leading line yielding curve; and finally, taking an outer normal vector of the cylindrical face as auxiliary information of vector interpolation of a cutter shaft of a leading line yielding track line, so as to obtain the cutter shaft vector of the leading line yielding track. The method disclosed by the invention has commonality and is suitable for spiral machining of a blade body of any blade; and the leading line yielding curve and the cutter shaft vector of a cutter site on the yielding curve can be effectively generated. Actual production verifies that the cutter shaft vector generated by the method is stable and smooth, the machining quality and the machining efficiency of the blade are improved and the service life of a machine tool and a tool is prolonged.

Description

Blade screw mills in the process edge head and dodges the cutter shaft control method of track

Technical field

The present invention relates to the blade mechanism processing technique field, be specially a kind of blade screw and mill in the process edge head and dodge the cutter shaft control method of track.

Background technology

Complex-shaped, the work under bad environment of engine blade, especially blade of aviation engine require it must have accurate dimensions, shape and strict surface integrity accurately, adopt multi-axis numerical control Milling Process process forming usually.The milling mode that adopts in the numerical control processing technology of blade has a milling, side milling method and spiral milling.Clamping times is few because helical milling has, Cutting trajectory is continuous, the working (machining) efficiency advantages of higher, receives the industry common concern.But; The edge head is that blade screw mills the topmost influence area of crudy; So all being method that adopt to reserve certain surplus, the processing of blade front and rear edge curved surface avoided cutting, in addition because in that to add the man-hour cutter location intensive relatively, the cutter shaft corner is excessive under the cutting state; Deal with very difficulty, be easy to cause and cut.To such problem, the blade high-quality and high-efficiency helical milling processing method that a kind of band edge head is dodged has been proposed in the prior art, utilize three non-uniform B-spline curve to provide the building method of dodging curve.The generating tool axis vector that this method is dodged geometric locus for the edge head all is to adopt the cutter location generating tool axis vector of blade Cutting trajectory line two-end-point to carry out the interpolation acquisition; Yet these two generating tool axis vector angles differ bigger; Even reach 180 °; This moment, the generating tool axis vector uncertainty often appearred in interpolation, needed more information just can guarantee to obtain stable generating tool axis vector, thereby made blade screw processing be able to normally carry out.

Summary of the invention

The technical problem that solves

Be to solve the problem that prior art exists, the present invention proposes a kind of blade screw and mill in the process edge head and dodge the cutter shaft control method of track, relate to blade and contain cylinder design, edge head and dodge the curve design and dodge problem such as track cutter shaft generation.

Technical scheme

This method is according to the physical dimension of blade; The face of cylinder will be contained as secondary surface in the containing face of cylinder of design blade, and structure edge head is dodged curve; And utilize the outer method on the face of cylinder to vow the supplementary of dodging trajectory generating tool axis vector interpolation as the edge head, obtain the edge head and dodge the track generating tool axis vector.

Technical scheme of the present invention is:

Said a kind of blade screw mills in the process edge head and dodges the cutter shaft control method of track, it is characterized in that: may further comprise the steps:

Step 1: structure blade cylinder secondary surface:

The blade curved surface of processed blade is a parametric surface, and the blade profile line is that v is to curve;

Step 1.1: the curve C of getting v=0.0 in the leaf pelvic curvature face ₁Curve C with v=0.0 in the blade back curved surface ₂, some a (x _a, y _a, z _a), c (x _c, y _c, z _c), e (x _e, y _e, z _e) be curve C ₁Two end points and mid point, some b (x _b, y _b, z _b), d (x _d, y _d, z _d), f (x _f, y _f, z _f) be curve C ₂Two end points and mid point, the initial tip circle center of circle that obtains the cylinder secondary surface is O _u(x _u, y _u, z _u):

$\left[\begin{array}{c}{x}_u\\ y_u\\ z_u\end{array}\right]=\frac{1}{6}\·\left[\begin{array}{c}{x}_a+x_b{+x}_c+x_d+x_e+x_f\\ y_a+y_b+y_c+y_d+y_e+y_f\\ z_a+z_b+z_c+z_d+z_e{+z}_f\end{array}\right]$

Get the curve C of v=1.0 in the leaf pelvic curvature face ₃Curve C with v=1.0 in the blade back curved surface ₄, some α (x _α, y _α, z _α), φ (x _φ, y _φ, z _φ), γ (x _γ, y _γ, z _γ) be curve C ₃Two end points and mid point, some β (x _β, y _β, z _β),

η (x _η, y _η, z _η) be curve C ₄Two end points and mid point, the round heart in the initial end that obtains the cylinder secondary surface is O _l(x _l, y _l, z _l):

Step 1.2: the radius R of cylinder secondary surface _cBe R _c=d _Max+ ε R, wherein d _MaxBe the ultimate range of edge head region to cylinder secondary surface axial line, R is a tool radius, ε be prevent cutter when dodging with the bump adjustment coefficient of interference of blade edge head region; Cylinder secondary surface axial line is O _uO _lLine;

Step 1.3: with curve C ₁, C ₂, C ₃, C ₄The two ends end points project on the cylinder secondary surface axial line, obtain in eight subpoints two the longest some A of distance between any two ₁And A ₂To put A ₁And A ₂Move the distance that is not less than R respectively laterally along cylinder secondary surface axial line, obtain the final tip circle center of circle O ' of cylinder secondary surface _uWith the round heart O ' in the final end _l

Step 2: structure edge head is dodged curve:

P ' ₀, P ₀Penult cutter location and last cutter location for the cutter spacing trajectory on blade one N-Side surf; P ₉, P ' ₉First cutter location and second cutter location for next the bar cutter spacing trajectory on the blade opposite side curved surface;

Step 2.1: along P ' ₀P ₀Tangential direction is r with the radius ₁The structure central angle is 30 ° ~ 45 ° minor arc P ₀P ₁, minor arc P ₀P ₁Towards the blade curved surface outside, r ₁Be circular arc withdrawing radius; Along P ' ₉P ₉Tangential direction is r with the radius ₂The structure central angle is 30 ° ~ 45 ° minor arc P ₉P ₈, minor arc P ₉P ₈Towards the blade curved surface outside, r ₂Be circular arc feed radius;

Step 2.2: along P ₁The tangential direction straight line of some place circular arc extends, and obtains straightway P ₁P ₃, P ₃For extending the intersection point of straight line and cylinder secondary surface; Along P ₈The tangential direction straight line of some place circular arc extends, and obtains straightway P ₈P ₆, P ₆For extending the intersection point of straight line and cylinder secondary surface;

Step 2.3: on the cylinder secondary surface, get a P ₃And P ₆Between the shortest curved section P of arc length ₃P ₆

Step 2.4: at straightway P ₁P ₃On get a P ₂, at curved section P ₃P ₆On get a P ₄, line segment P ₂P ₃Length equal curve P ₃P ₄Arc length; At straightway P ₈P ₆On get a P ₇, at curved section P ₃P ₆On get a P ₅, line segment P ₆P ₇Length equal curve P ₅P ₆Arc length; Point P ₃, P ₄, P ₅And P ₆Be curved section P ₃P ₆On successively four points;

Step 2.5: with a P ₂, P ₃And P ₄Structure SPL P ₂P ₄, SPL P ₂P ₄With straightway P ₁P ₃With curved section P ₄P ₅Tangent; With a P ₅, P ₆And P ₇Structure SPL P ₅P ₇, SPL P ₅P ₇With straightway P ₈P ₆With curved section P ₄P ₅Tangent;

Connect minor arc P successively ₀P ₁, straightway P ₁P ₂, SPL P ₂P ₄, curved section P ₄P ₅, SPL P ₅P ₇, straightway P ₇P ₈With minor arc P ₈P ₉Obtain constructing the edge head and dodge curve;

Step 3: generate the edge head and dodge the curve cutter location:

Step 3.1: even discrete curve section P ₄P ₅, obtain curved section P ₄P ₅On the point of a knife point; With curved section P ₄P ₅Go up the generating tool axis vector of the outer direction of normal of each point of a knife point on the cylinder secondary surface, obtain curved section P as each point of a knife point ₄P ₅Cutter location;

Step 3.2: segmentation discrete curve group P ₀P ₁P ₂P ₄, obtain curve group P ₀P ₁P ₂P ₄On point of a knife point set Q={Q _i| i=0 ..., N}, wherein Q _OWith P ₀Overlap Q _NWith P ₄Overlap;

Step 3.3: adopt the plain interpolation of quaternary to obtain Q={Q _i| i=1 ..., the generating tool axis vector at N-1} point place:

Step 3.3.1: calculate P ₀P ₁P ₂P ₄The length overall ts of curved section:

$\mathrm{ts}=\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}\left|Q_k{Q}_{k+1}\right|$

Wherein | Q _kQ _K+1| expression point Q _kAnd Q _K+1Between the length of line segment;

Step 3.3.2: calculate from starting point Q _OTo Q _iPath length ds _i:

${\mathrm{ds}}_i=\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left|Q_k{Q}_{k+1}\right|$

Step 3.3.3:Q={Q _i| i=1 ..., the generating tool axis vector of each point is among the N-1}:

$v_i=\frac{\sin (1-t_i)\mathrm{\θ}}{\sin \mathrm{\θ}}{v}_0+\frac{\sin t_i\mathrm{\θ}}{\sin \mathrm{\θ}}{v}_4.(i=1,\·\·\·,N-1)$

T wherein _i=ds _i/ ts, v ₀Be P ₀The unit generating tool axis vector at some place, v ₄Be the P that obtains in the step 3.1 ₄The unit generating tool axis vector at some place, θ=arccos (v ₀V ₄);

Step 3.4: confirm curve group P according to the method in step 3.2 to the step 3.3 ₅P ₇P ₈P ₉Cutter location.

Said a kind of blade screw mills in the process edge head and dodges the cutter shaft control method of track, it is characterized in that: line segment P ₆P ₇Length the line is busy the section P ₆P ₈The ratio of length and line segment P ₂P ₃The line is busy the section P ₁P ₃The ratio of length is identical, is 5% ~ 30%.

Said a kind of blade screw mills in the process edge head and dodges the cutter shaft control method of track, it is characterized in that: curve group P ₀P ₁P ₂P ₄It is curve group P that the upper slitter cusp is concentrated the arc length of adjacent point of a knife point ₀P ₁P ₂P ₄5% of path length; Curve group P ₅P ₇P ₈P ₉It is curve group P that the upper slitter cusp is concentrated the arc length of adjacent point of a knife point ₅P ₇P ₈P ₉5% of path length.

Beneficial effect

The method that the present invention proposes has versatility, is suitable for the situation of any blade blade spiral processing, can effectively generate the generating tool axis vector that the edge head is dodged curve and dodged cutter location on the geometric locus.Through the actual production checking, the generating tool axis vector light stable that this method generates is suitable, has improved processing of leaves quality and working (machining) efficiency, has prolonged the service life of lathe and cutter.

Description of drawings

Fig. 1: sketch map is calculated in the initial tip circle center of circle;

Fig. 2: blade cylinder secondary surface organigram;

Fig. 3: the edge head is dodged the curve construction sketch map;

Fig. 4: dodge curve cutter location generating tool axis vector among the embodiment and distribute;

Fig. 5: generating tool axis vector variable angle among the embodiment.

Wherein: 1, rafter plate; 2, blade curved surface.

The specific embodiment

Below in conjunction with specific embodiment the present invention is described:

Present embodiment is processed as example with five endless knife of aero-engine model blade, and according to the cutter location track of second order Taylor approximate algorithm calculating blade curved surface area, wherein, the endless knife radius R is 8mm.

The cutter shaft control method that the edge head is dodged track in the present embodiment may further comprise the steps:

Step 1: structure blade cylinder secondary surface:

It is the instrument that realization edge head is dodged curve that blade contains the cylinder secondary surface, confirms that face of cylinder key is the tip circle center of circle, the round heart in the end and cylindrical radius, shown in accompanying drawing 1.The blade curved surface of processed blade (leaf pelvic curvature face, blade back curved surface) is a parametric surface, and the blade profile line is that v is to curve; The limit parameter at blade tip place is v=0.0.

Step 1.1: the curve C of getting v=0.0 in the leaf pelvic curvature face ₁Curve C with v=0.0 in the blade back curved surface ₂, some a (x _a, y _a, z _a), c (x _c, y _c, z _c), e (x _e, y _e, z _e) be curve C ₁Two end points and mid point, some b (x _b, y _b, z _b), d (x _d, y _d, z _d), f (x _f, y _f, z _f) be curve C ₂Two end points and mid point, the initial tip circle center of circle that obtains the cylinder secondary surface is O _u(x _u, y _u, z _u):

$\left[\begin{array}{c}{x}_u\\ y_u\\ z_u\end{array}\right]=\frac{1}{6}\·\left[\begin{array}{c}{x}_a+x_b{+x}_c+x_d+x_e+x_f\\ y_a+y_b+y_c+y_d+y_e+y_f\\ z_a+z_b+z_c+z_d+z_e{+z}_f\end{array}\right]$

Get the curve C of v=1.0 in the leaf pelvic curvature face ₃Curve C with v=1.0 in the blade back curved surface ₄, some α (x _α, y _α, z _α), φ (x _φ, y _φ, z _φ), γ (x _γ, y _γ, z _γ) be curve C ₃Two end points and mid point, some β (x _β, y _β, z _β),

η (x _η, y _η, z _η) be curve C ₄Two end points and mid point, the round heart in the initial end that obtains the cylinder secondary surface is Ol (x _l, y _l, z _l):

Step 1.2: the radius R of cylinder secondary surface _cBe R _c=d _Max+ ε R, wherein d _MaxBe the ultimate range of edge head region to cylinder secondary surface axial line, R is a tool radius, ε be prevent cutter when dodging with the bump adjustment coefficient of interference of blade edge head region; Cylinder secondary surface axial line is O _uO _lLine;

Step 1.3: with curve C ₁, C ₂, C ₃, C ₄The two ends end points project on the cylinder secondary surface axial line, obtain in eight subpoints two the longest some A of distance between any two ₁And A ₂To put A ₁And A ₂Move the distance that is not less than R respectively laterally along cylinder secondary surface axial line, obtain the final tip circle center of circle O ' of cylinder secondary surface _uWith the round heart O ' in the final end _lShown in accompanying drawing 2.

Step 2: structure edge head is dodged curve:

The edge head is dodged curve through cutting out blade curved surface, idle stroke, three processes of incision blade opposite side curved surface.This method is dodged curve with the edge head and is divided into seven sections trajectories, shown in accompanying drawing 3.

P ' ₀, P ₀Penult cutter location and last cutter location for the cutter spacing trajectory on blade one N-Side surf; P ₉, P ' ₉First cutter location and second cutter location for next the bar cutter spacing trajectory on the blade opposite side curved surface;

Step 2.1: along P _O' P _OTangential direction is r with the radius ₁The structure central angle is 30 ° ~ 45 ° minor arc P ₀P ₁, minor arc P ₀P ₁Towards the blade curved surface outside, r ₁Be circular arc withdrawing radius; Along P ₉' P ₉Tangential direction is r with the radius ₂The structure central angle is 30 ° ~ 45 ° minor arc P ₉P ₈, minor arc P ₉P ₈Towards the blade curved surface outside, r ₂Be circular arc feed radius;

Step 2.2: along P ₁The tangential direction straight line of some place circular arc extends, and obtains straightway P ₁P ₃, P ₃For extending the intersection point of straight line and cylinder secondary surface; Along P ₈The tangential direction straight line of some place circular arc extends, and obtains straightway P ₈P ₆, P ₆For extending the intersection point of straight line and cylinder secondary surface;

Step 2.3: on the cylinder secondary surface, get a P ₃And P ₆Between the shortest curved section P of arc length ₃P ₆

Step 2.4: at straightway P ₁P ₃On get a P ₂, at curved section P ₃P ₆On get a P ₄, line segment P ₂P ₃Length equal curve P ₃P ₄Arc length; At straightway P ₈P ₆On get a P ₇, at curved section P ₃P ₆On get a P ₅, line segment P ₆P ₇Length equal curve P ₅P ₆Arc length; Point P ₃, P ₄, P ₅And P ₆Be curved section P ₃P ₆On successively four points;

Line segment P ₆P ₇Length the line is busy the section P ₆P ₈The ratio of length and line segment P ₂P ₃The line is busy the section P ₁P ₃The ratio of length is identical, is 5% ~ 30%, gets 5% in the present embodiment;

Step 2.5: with a P ₂, P ₃And P ₄Structure SPL P ₂P ₄, SPL P ₂P ₄With straightway P ₁P ₃With curved section P ₄P ₅Tangent; With a P ₅, P ₆And P ₇Structure SPL P ₅P ₇, SPL P ₅P ₇With straightway P ₈P ₆With curved section P ₄P ₅Tangent;

Connect minor arc P successively ₀P ₁, straightway P ₁P ₂, SPL P ₂P ₄, curved section P ₄P ₅, SPL P ₅P ₇, straightway P ₇P ₈With minor arc P ₈P ₉Obtain constructing the edge head and dodge curve;

Step 3: generate the edge head and dodge the curve cutter location:

Step 3.1:P ₄P ₅Curved section is to be positioned on the cylinder secondary surface, evenly discrete curve section P ₄P ₅, obtain curved section P ₄P ₅On the point of a knife point; With curved section P ₄P ₅Go up the generating tool axis vector of the outer direction of normal of each point of a knife point on the cylinder secondary surface, obtain curved section P as each point of a knife point ₄P ₅Cutter location, realize the generating tool axis vector smooth change on the cylinder secondary surface;

Step 3.2: segmentation discrete curve group P ₀P ₁P ₂P ₄, obtain curve group P ₀P ₁P ₂P ₄On point of a knife point set Q={Q _i| i=0 ..., N}, wherein Q _OWith P ₀Overlap Q _NWith P ₄Overlap; Get curve group P in the present embodiment ₀P ₁P ₂P ₄It is curve group P that the upper slitter cusp is concentrated the arc length of adjacent point of a knife point ₀P ₁P ₂P ₄5% of path length is to guarantee at P ₀Point is to P ₄Cutter shaft evenly slowly changes on the point curve section;

Step 3.3: adopt the plain interpolation of quaternary to obtain Q={Q _i| i=1 ..., the generating tool axis vector at N-1} point place:

Step 3.3.1: calculate P ₀P ₁P ₂P ₄The length overall ts of curved section:

$\mathrm{ts}=\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}\left|Q_k{\mathrm{<figure-callout\; id="1"\; label="Q\; k\; +"\; filenames="HDA00001877770200011.png"\; state="\{\{state\}\}">Q</figure-callout>}}_{k+}\right|$

Wherein | Q _kQ _K+1| expression point Q _kAnd Q _K+1Between the length of line segment;

Step 3.3.2: calculate from starting point Q _OTo Q _iPath length ds _i:

${\mathrm{ds}}_i=\underset{k=0}{\overset{i-1}{\mathrm{\&Sigma;}}}\left|Q_k{\mathrm{<figure-callout\; id="1"\; label="Q\; k\; +"\; filenames="HDA00001877770200011.png"\; state="\{\{state\}\}">Q</figure-callout>}}_{k+}\right|$

Step 3.3.3:Q={Q _i| i=1 ..., the generating tool axis vector of each point is among the N-1}:

$v_i=\frac{\sin (1-t_i)\mathrm{\&theta;}}{\sin \mathrm{\&theta;}}{v}_0+\frac{\sin t_i\mathrm{\&theta;}}{\sin \mathrm{\&theta;}}{\mathrm{<figure-callout\; id="4"\; label="v"\; filenames="HDA00001877770200013.png"\; state="\{\{state\}\}">v</figure-callout>}}_4.(i=1,\&CenterDot;\&CenterDot;\&CenterDot;,N-1)$

T wherein _i=ds _i/ s, v ₀Be P ₀The unit generating tool axis vector at some place is because P ₀Point is last cutter location of blade one N-Side surf, so its unit generating tool axis vector can be known v ₄Be the P that obtains in the step 3.1 ₄The unit generating tool axis vector at some place, θ=arccos (v ₀V ₄);

Step 3.4: confirm curve group P according to the method in step 3.2 to the step 3.3 ₅P ₇P ₈P ₉Cutter location:

Segmentation discrete curve group P ₅P ₇P ₈P ₉, obtain curve group P ₅P ₇P ₈P ₉On point of a knife point set U={U _i| i=0 ..., M}, wherein U ₀With P ₉Overlap U _MWith P ₅Overlap; Get curve group P in the present embodiment ₅P ₇P ₈P ₉It is curve group P that the upper slitter cusp is concentrated the arc length of adjacent point of a knife point ₅P ₇P ₈P ₉5% of path length is to guarantee at P ₉Point is to P ₅Cutter shaft evenly slowly changes on the point curve section;

Adopt the plain interpolation of quaternary to obtain U={U _i| i=1 ..., the generating tool axis vector at M-1} point place:

Step 3.4.1: calculate P ₅P ₇P ₈P ₉The length overall ks of curved section:

$\mathrm{ks}=\underset{k=0}{\overset{M-1}{\mathrm{\&Sigma;}}}\left|U_k{U}_{k+1}\right|$

Wherein | U _kU _K+1| expression point U _kAnd U _K+1Between the length of line segment;

Step 3.4.2: calculate from starting point U ₀Path length ls to Ui _i:

${\mathrm{ls}}_i=\underset{k=0}{\overset{i-1}{\mathrm{\&Sigma;}}}\left|U_k{U}_{k+1}\right|$

Step 3.4.3:U={U _i| i=1 ..., the generating tool axis vector of each point is among the M-1}:

$v_i=\frac{\sin (1-o_i)\mathrm{\&theta;}}{\sin \mathrm{\&theta;}}{v}_9+\frac{\sin o_i\mathrm{\&theta;}}{\sin \mathrm{\&theta;}}{\mathrm{<figure-callout\; id="5"\; label="v"\; filenames="HDA00001877770200021.png,HDA00001877770200022.png"\; state="\{\{state\}\}">v</figure-callout>}}_5,(i=1\&CenterDot;\&CenterDot;\&CenterDot;,M-1)$

O wherein _i=ls _i/ ks, v ₉Be P ₉The unit generating tool axis vector at some place is because P ₉Point is first cutter location of blade opposite side curved surface, so its unit generating tool axis vector can be known v ₅Be the P that obtains in the step 3.1 ₅The unit generating tool axis vector at some place,

$\mathrm{\&theta;}=\arccos (v_9\&CenterDot;v_5).$

Obtain the edge head thus and dodge the cutter location of curve; The adjacent cutter spacing trajectory that is chosen in the present embodiment on the blade curved surface parameter v=0.3 curve is analyzed; It dodges the curve cutter location and the projection of generating tool axis vector on XOY plane is as shown in Figure 4; The two-end-point generating tool axis vector angle that the edge head is dodged trajectory is 177.8 °, and it is as shown in Figure 5 that the edge head is dodged the generating tool axis vector variable angle of curve.

Claims (3)

1. a blade screw mills in the process edge head and dodges the cutter shaft control method of track, it is characterized in that: may further comprise the steps:

Step 1: structure blade cylinder secondary surface:

The blade curved surface of processed blade is a parametric surface, and the blade profile line is that v is to curve;

Step 1.1: the curve C of getting v=0.0 in the leaf pelvic curvature face ₁Curve C with v=0.0 in the blade back curved surface ₂, some a (x _a, y _a, z _a), c (x _c, y _c, z _c), e (x _e, y _e, z _e) be curve C ₁Two end points and mid point, some b (x _b, y _b, z _b), d (x _d, y _d, z _d), f (x _f, y _f, z _f) be curve C ₂Two end points and mid point, the initial tip circle center of circle that obtains the cylinder secondary surface is O _u(x _u, y _u, z _u):

$\left[\begin{array}{c}{x}_u\\ y_u\\ z_u\end{array}\right]=\frac{1}{6}\&CenterDot;\left[\begin{array}{c}{x}_a+x_b{+x}_c+x_d+x_e+x_f\\ y_a+y_b+y_c+y_d+y_e+y_f\\ z_a+z_b+z_c+z_d+z_e{+z}_f\end{array}\right]$

Get the curve C of v=1.0 in the leaf pelvic curvature face ₃Curve C with v=1.0 in the blade back curved surface ₄, some α (x _α, y _α, z _α), φ (x _φ, y _φ, z _φ), γ (x _γ, y _γ, z _γ) be curve C ₃Two end points and mid point, some β (x _β, y _β, z _β),

η (x _η, y _η, z _η) be curve C ₄Two end points and mid point, the round heart in the initial end that obtains the cylinder secondary surface is O _l(x _l, y _l, z _l):

Step 1.2: the radius R of cylinder secondary surface _cBe R _c=d _Max+ ε R, wherein d _MaxBe the ultimate range of edge head region to cylinder secondary surface axial line, R is a tool radius, ε be prevent cutter when dodging with the bump adjustment coefficient of interference of blade edge head region; Cylinder secondary surface axial line is O _uO _lLine;

Step 1.3: with curve C ₁, C ₂, C ₃, C ₄The two ends end points project on the cylinder secondary surface axial line, obtain in eight subpoints two the longest some A of distance between any two ₁And A ₂To put A ₁And A ₂Move the distance that is not less than R respectively laterally along cylinder secondary surface axial line, obtain the final tip circle center of circle O ' of cylinder secondary surface _uWith the round heart O ' in the final end _l

Step 2: structure edge head is dodged curve:

P ' ₀, P ₀Penult cutter location and last cutter location for the cutter spacing trajectory on blade one N-Side surf; P ₉, P ' ₉First cutter location and second cutter location for next the bar cutter spacing trajectory on the blade opposite side curved surface;

Step 2.1: along P ' ₀P ₀Tangential direction is r with the radius ₁The structure central angle is 30 ° ~ 45 ° minor arc P ₀P ₁, minor arc P ₀P ₁Towards the blade curved surface outside, r ₁Be circular arc withdrawing radius; Along P ' ₉P ₉Tangential direction is r with the radius ₂The structure central angle is 30 ° ~ 45 ° minor arc P ₉P ₈, minor arc P ₉P ₈Towards the blade curved surface outside, r ₂Be circular arc feed radius;

Step 2.2: along P ₁The tangential direction straight line of some place circular arc extends, and obtains straightway P ₁P ₃, P ₃For extending the intersection point of straight line and cylinder secondary surface; Along P ₈The tangential direction straight line of some place circular arc extends, and obtains straightway P ₈P ₆, P ₆For extending the intersection point of straight line and cylinder secondary surface;

Step 2.3: on the cylinder secondary surface, get a P ₃And P ₆Between the shortest curved section P of arc length ₃P ₆

Step 2.4: at straightway P ₁P ₃On get a P ₂, at curved section P ₃P ₆On get a P ₄, line segment P ₂P ₃Length equal curve P ₃P ₄Arc length; At straightway P ₈P ₆On get a P ₇, at curved section P ₃P ₆On get a P ₅, line segment P ₆P ₇Length equal curve P ₅P ₆Arc length; Point P ₃, P ₄, P ₅And P ₆Be curved section P ₃P ₆On successively four points;

Step 2.5: with a P ₂, P ₃And P ₄Structure SPL P ₂P ₄, SPL P ₂P ₄With straightway P ₁P ₃With curved section P ₄P ₅Tangent; With a P ₅, P ₆And P ₇Structure SPL P ₅P ₇, SPL P ₅P ₇With straightway P ₈P ₆With curved section P ₄P ₅Tangent;

Connect minor arc P successively ₀P ₁, straightway P ₁P ₂, SPL P ₂P ₄, curved section P ₄P ₅, SPL P ₅P ₇, straightway P ₇P ₈With minor arc P ₈P ₉Obtain constructing the edge head and dodge curve;

Step 3: generate the edge head and dodge the curve cutter location:

Step 3.1: even discrete curve section P ₄P ₅, obtain curved section P ₄P ₅On the point of a knife point; With curved section P ₄P ₅Go up the generating tool axis vector of the outer direction of normal of each point of a knife point on the cylinder secondary surface, obtain curved section P as each point of a knife point ₄P ₅Cutter location;

Step 3.2: segmentation discrete curve group P ₀P ₁P ₂P ₄, obtain curve group P ₀P ₁P ₂P ₄On point of a knife point set Q={Q _i| i=0 ..., N}, wherein Q _OWith P ₀Overlap Q _NWith P ₄Overlap;

Step 3.3: adopt the plain interpolation of quaternary to obtain Q={Q _i| i=1 ..., the generating tool axis vector at N-1} point place:

Step 3.3.1: calculate P ₀P ₁P ₂P ₄The length overall ts of curved section:

$\mathrm{ts}=\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}\left|Q_k{Q}_{k+1}\right|$

Wherein | Q _kQ _K+1| expression point Q _kAnd Q _K+1Between the length of line segment;

Step 3.3.2: calculate from starting point Q _OTo Q _iPath length ds _i:

${\mathrm{ds}}_i=\underset{k=0}{\overset{i-1}{\mathrm{\&Sigma;}}}\left|Q_k{Q}_{k+1}\right|$

Step 3.3.3:Q={Q _i| i=1 ..., the generating tool axis vector of each point is among the N-1}:

$v_i=\frac{\sin (1-t_i)\mathrm{\&theta;}}{\sin \mathrm{\&theta;}}{v}_0+\frac{\sin t_i\mathrm{\&theta;}}{\sin \mathrm{\&theta;}}{v}_4.(i=1,\&CenterDot;\&CenterDot;\&CenterDot;,N-1)$

T wherein _i=ds _i/ ts, v ₀Be P ₀The unit generating tool axis vector at some place, v ₄Be the P that obtains in the step 3.1 ₄The unit generating tool axis vector at some place, θ=arccos (v ₀V ₄);

Step 3.4: confirm curve group P according to the method in step 3.2 to the step 3.3 ₅P ₇P ₈P ₉Cutter location.

2. mill in the process edge head according to the said a kind of blade screw of claim 1 and dodge the cutter shaft control method of track, it is characterized in that: line segment P ₆P ₇Length the line is busy the section P ₆P ₈The ratio of length and line segment P ₂P ₃The line is busy the section P ₁P ₃The ratio of length is identical, is 5% ~ 30%.

3. mill in the process edge head according to claim 1 or 2 said a kind of blade screws and dodge the cutter shaft control method of track, it is characterized in that: curve group P ₀P ₁P ₂P ₄It is curve group P that the upper slitter cusp is concentrated the arc length of adjacent point of a knife point ₀P ₁P ₂P ₄5% of path length; Curve group P ₅P ₇P ₈P ₉It is curve group P that the upper slitter cusp is concentrated the arc length of adjacent point of a knife point ₅P ₇P ₈P ₉5% of path length.

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