CN101745672B - Method for processing slots on turbine rotor for mushroom-shaped blade roots - Google Patents

Abstract

The present invention relates to a method for processing slots on a turbine rotor for mushroom-shaped blade roots. Slots for blade roots are milled by a profile milling cutter on a numerical control processing center. The numerical control processing center is provided with two rectilinear motion shafts and a rotating shaft at least. The rotating shaft is a lathe rotating table. The milling cutter is arranged on the cutter head of the main shaft of the numerical control processing center, and the milling cutter is driven by the shaft to rotate. The blade is fixed on the rotating table of the numerical control processing center, the radiant line of the blade is parallel with the main shaft and penetrates through the rotating center of the table, and the slots for blade roots are orientated to the cutter head. The milling cutter is driven by the rotating table to rotate, the blade accordingly makes circumferential motion, and interpolation compensation is made for the circumferential motion angle by the rotating table. The two rectilinear motion shafts are parallel to the central plane of the mushroom-shaped blade roots, and interpolation compensation is made for displacements of the rotating table in the direction of the rectilinear motion shafts. Thus, when the milling cutter is used for cutting any processing point on an arc curve, the cutter axial vector is always on the normal line of the processing point and points to the arc center.

Description

The processing method of slots on turbine rotor for mushroom-shaped blade roots

Technical field

The present invention relates to the processing method of turbine blade, be specifically related to the processing method of blade bacterial type blade root type groove.

Background technology

In the various blade root forms of turbine blade, the blade of bacterial type blade root is from the impeller of rotor of axially packing into, and the mating surface of blade root and impeller is unique circular arc type groove, and its cross section profile shape is seen Fig. 1, Fig. 2, and the arc radius R at bottom land point place is maximum radius.To process with special purpose machine tool at present, characteristics are: workpiece is fixed on the workbench by anchor clamps, can not move, and the main shaft that milling cutter is installed then is arranged on the rotating disk, can do circular-rotation, during clamping workpiece, adjust machined surface to the distance of pivot, make it to equal the arc radius of bacterial type blade root, during milling, main shaft rotates and with dial rotation, the movement locus of milling cutter is a circular arc, thereby processes the circular arc type groove of bacterial type blade root.

The problem that this technique exists is:

1. this is that a kind of typical circular arc mills, and external diameter (cutting edge size) requirement that circular arc mills cutter is very strict, and cutting edge slightly has wearing and tearing, and just possibility out-of-size scope can only be scrapped, therefore the cutter consumption is very large.

2. relatively poor because of the structural rigidity of lathe, therefore the rated speed of main shaft is lower, the highest only have 1400 rev/mins, therefore working (machining) efficiency is low, and the high point of speed, lathe will tremble, and affects machining accuracy and fineness.

3. the function singleness of special purpose machine tool, can only Machining Arc, other machined surface of blade root (two radial end faces and two axial ends) needs to use other machine tooling, not only so that complex technical process, process-cycle is long, and need to carry out secondary clamping, the surface that easy damage has processed, cause this blade to be scrapped, affect the yield rate of blade.

In addition, along with the technological progress of Steam Turbine, requirements at the higher level have been proposed for intensity, the heat resistance of blade root, on original blade material basis added more alloying element, such as chromium, tungsten, vanadium etc.It is more and more harder that blade becomes, and cutter has been proposed more stern challenge, and it is large that the diffusive wear of cutter becomes, and further shortened cutting-tool's used life.The milling cutter that above-mentioned technique is used is high-speed steel tool, and hardness is limited, and on the one hand, it easily weares and teares, and consumption is too large, high cost; On the other hand, can not high-speed cutting, working (machining) efficiency is low, can not satisfy the needs of blade batch production.

Summary of the invention

Purpose of the present invention, provide a kind of processing method of slots on turbine rotor for mushroom-shaped blade roots, with the method processing blade root type groove, not only working (machining) efficiency is high, can satisfy the needs of producing blade in enormous quantities, also can reduce the requirement to the cutting edge roundness size, reduce the cutter consumption, reduce production costs, can realize that also clamped one time processes all machined surfaces of blade root, avoid processing to sustain damage because of secondary clamping, improve the yield rate of blade.

The technical solution of invention is:

A kind of processing method of slots on turbine rotor for mushroom-shaped blade roots is on numerical control machining center, with the type groove of molded line milling cutter milling blade root; Described numerical control machining center has two linear motion axis and a rotating shaft at least, and rotating shaft is rotation workbench of machine tool; Milling cutter is installed on the milling head of numerical control machining center main shaft, drives the milling cutter rotation by this axle; Described blade is fixed on the rotary table of numerical control machining center, and the radiation of blade is parallel with main shaft and by the worktable rotary center, blade root type channel opening is towards milling head; Drive blade rotation by rotary table, make the corresponding circumferential movement of leaf development, rotary table carries out Interpolation compensation to the angle of circumferential movement; Two linear motion axis are parallel with the bacterial type blade root central plane, the position degree of rotary table on this two linear axis direction carried out Interpolation compensation, make milling cutter when arbitrary processing stand cuts on the circular curve, generating tool axis vector is all on the normal of this processing stand, point to center of arc, thereby the relative movement orbit that makes workpiece and milling cutter is circular arc, and the direction of this circular arc is just in time opposite with rotary table circular arc that movement locus forms, the two phase difference of pi radian.

The concrete grammar of described Interpolation compensation is: with blade rotary table in place fixing after, measure the concrete dimensional parameters of blade root type groove, in programming software, set up bacterial type blade root type channel mould type according to parameter value, write again procedure, after program imported Digit Control Machine Tool, can process the type groove of bacterial type blade root.

The another kind of concrete grammar of described Interpolation compensation control is:

(1). set up the Mathematical Modeling of compensation control;

1.. calculate the central angle 2A of workpiece to be machined type groove according to known parameters

Pivot is to the distance L on blade root type groove circular arc summit;

The radius R of processed circular arc;

The chord length XC of processed circular arc (first letter of this chord length by name);

These parameters have following geometrical relationship:

L＝OD；R＝O ₁D＝O ₁P；XC＝CP＝2PG；2A＝∠PO ₁C；

tan(A)＝PG/GO ₁；PG＝(1/2)×(XC)；

${\mathrm{<figure-callout\; id="1"\; label="GO"\; filenames="H2009102635022E00041.png"\; state="\{\{state\}\}">GO</figure-callout>}}_1=\sqrt{O_1{P}^2-P{G}^2}=\sqrt{R^2-1/4X{C}^2};$

$A=\arctan \left(\frac{\mathrm{PG}}{{\mathrm{GO}}_1}\right)=\arctan \left(\frac{\mathrm{XC}/2}{\sqrt{R^2-1/4{\mathrm{XC}}^2}}\right)$

Therefore $2A=2\arctan \left(\frac{\mathrm{XC}/2}{\sqrt{R^2-1/4X{C}^2}}\right)---\left(1\right)$

2.. determine that arbitrfary point P on the same circular arc of workpiece to be machined arc surface is to the distance of pivot, coordinate and the initial angle E (in order to write and to read conveniently, P point just represents with X and Z at the component of X and Z-direction) of some P:

P point (being OP) component of Z direction in coordinate system is:

Z＝OG＝OD+O ₁D-O ₁G＝L+R-O ₁P cos(A)＝L+R-Rcos(A)

Be Z=L+R-Rcos (A) (2)

P point (being OP) component of directions X in coordinate system is: X=O ₁Psin (A)

Be X=Rsin (A) (3)

The value of initial angle E is: E=arctan (X/Z) (4)

The P point to the distance of pivot is:

$\mathrm{OP}=\sqrt{X^2+Z^2}---\left(5\right)$

3.. the P point transformation arrives the coordinate that P ' puts after calculating pivot anglec of rotation A:

When the P point through the rotation transformation of B axle to P ' when point, the angle of B axle rotation is A, P and P ' they are 2 points on the same circumference take O as the center of circle, therefore OP=OP ', at this moment

P ' some component of Z direction in coordinate system is: Z ₁=OP ' cos (A+E)=OPcos (A+E)

P ' some component of directions X in coordinate system is: X ₁=OP ' sin (A+E)=OPsin (A+E)

(2). set cyclic variable

If angle step K=0.1, circulation initial value N=0, until $N=\frac{2A}{K},$ Be defined in the angle of reference axis Z below for negative, then anglec of rotation B1=-A+N*K.

(3). workpiece type groove circular curve is resolved into several processing stands, calculate coordinate figure and the anglec of rotation of obtaining each processing stand according to above-mentioned model.

(4) .. makes the NC program with coordinate figure and the anglec of rotation of above-mentioned each processing stand according to the model of lathe, imports the control system of numerical control machining center, just can process bacterial type blade root circular arc type groove.

Described molded line milling cutter is the carbide alloy profile milling cutter.

Technique effect of the present invention:

With the inventive method processing bacterial type blade root type groove, not only working (machining) efficiency is high, can satisfy the needs of producing blade in enormous quantities, also can reduce the requirement to the cutting edge roundness size, reduce the cutter consumption, reduce production costs, can realize that also clamped one time processes all machined surfaces of blade root, avoid processing to sustain damage because of secondary clamping, improve the yield rate of blade.Especially above-mentioned parameter compensation method has versatility, can process the bacterial type blade root type groove of various sizes, needn't programme separately to the blade of a certain concrete specification, and working (machining) efficiency significantly improves.

The below describes the present invention in detail to process blade root type groove at the horizontal digital-control machining center as example.

Description of drawings

Fig. 1 is bacterial type blade root type groove structure schematic diagram

Fig. 2 is that the K of Fig. 1 is to view

Coordinate transform and the angle step schematic diagram of processing stand a when Fig. 3 is compensation control

Coordinate transform and the angle step schematic diagram of processing stand b when Fig. 4 is compensation control

Workpiece circular arc and turntable rotated the corresponding relation schematic diagram of circular arc when Fig. 5 was compensation control

Fig. 6 is the geometrical relationship schematic diagram of compensation control mathematical model

Fig. 7 is the compensation control programming flow diagram of this method

The specific embodiment

Cut or owe to cut phenomenon in order to guarantee the accuracy of bacterial type blade root type grooved line, not produce, necessary strict guarantee cutter is consistent with blade root arc surface contact point place's generating tool axis vector and cambered surface normal direction in the working angles, that is: generating tool axis vector is pointed to the cambered surface center of circle constantly.In the lathe that cutter can not swing, can only realize this requirement by the rotation of workpiece and the Linear-moving of cutter.That is: when the flex point of Tool in Cutting circular curve, tool axis overlaps with the normal of this point, when other of Tool in Cutting circular curve, the normal parallel of tool axis and this point, because the cutter that the rotation of workpiece causes and the change in location of cambered surface contact point, compensated by the Linear-moving of cutter.Equidistantly behind the interpolation cambered surface molded line, the method vector of each interpolation point can be calculated by interpolation point and cambered surface molded line circle center line connecting.The method vector of each contact point is free vector on the cambered surface, therefore, the anglec of rotation of workbench can be calculated by the method vector, and the position of each interpolation point in machining coordinate system can be obtained through rotation transformation by the coordinate figure of each interpolation point on the former camber line on the camber line after workpiece rotates.Be each interpolation point of neutral line interpolation and synchronous rotary blade root cambered surface at machining coordinate, just can process the type groove of turbine blade bacterial type blade root.

The operation principle of numerical control machining center processing bacterial type blade root: milling head can not be made arc swing, can only do to move with axial (being Y-axis, Z-direction) up and down, therefore the point of processed curve can only in the accuracy of normal direction (being that direction is parallel with main shaft) processing guarantee molded line, be avoided cutting and interfering.When on the processing molded line circular arc except flex point during the arbitrfary point, its normal direction position will guarantee parallel with major axes orientation, point is along with the rotation of workbench on the processed blade bacterial type blade root circular arc, variation has occured in its position, therefore these points all need to compensate.Its principle is as follows:

1) when processing a point, see Fig. 3:

Because milling head can only axially-movable, therefore the point of a on the workbench needs after the anglec of rotation A, a1-a12 is just parallel with main shaft, and milling head just can be finished the milling that a is ordered.

2) when processing b point, see Fig. 4:

Because milling head can only axially-movable, therefore the point of the b on the workbench needs after the anglec of rotation B, b1-b12 is just parallel with main shaft, and milling head just can be finished the milling that b is ordered.

The unlimited five equilibrium of work circular arc, each point rotates corresponding angle, makes its normal parallel with main shaft, and when the turntable of lathe moved to A ' from A, milling cutter just can process the circular arc aa ' of bacterial type blade root, saw Fig. 5.As can be seen from Figure 5 will process the circular arc aa ' of bacterial type blade root, the lathe turntable will rotate orthodrome AA ' and could realize.

The interface of 3) calculating and exporting the NC program sees the following form 1.

The interface of the NC program of a certain concrete specification blade of table 1

Compensation control has following dual mode:

One, conventional compensation way

With blade rotary table in place fixing after, measure the concrete dimensional parameters of blade root type groove, in programming software, set up bacterial type blade root type channel mould type according to parameter value, write again procedure, program is imported Digit Control Machine Tool after, can process the type groove of bacterial type blade root.

But there is following problem in this mode, and namely the bacterial type blade root of each specification all needs to write the NC program behind the Independent modeling again, can't be general, and operation is loaded down with trivial details, affects working (machining) efficiency, therefore recommendation not.

Two, parametrization compensation way, concrete steps are:

(1). set up the Mathematical Modeling of compensation control, see Fig. 6;

1.. calculate the central angle 2A of workpiece to be machined type groove according to known parameters

Pivot is to the distance L on blade root type groove circular arc summit;

The radius R of processed circular arc;

The chord length XC of processed circular arc (first letter of this chord length by name);

These parameters have following geometrical relationship:

L＝OD；R＝O ₁D＝O ₁P；XC＝CP＝2PG；2A＝∠PO ₁C；

tan(A)＝PG/GO ₁；PG＝(1/2)×(XC)；

${\mathrm{<figure-callout\; id="1"\; label="GO"\; filenames="H2009102635022E00041.png"\; state="\{\{state\}\}">GO</figure-callout>}}_1=\sqrt{O_1{P}^2-P{G}^2}=\sqrt{R^2-1/4X{C}^2};$

$A=\arctan \left(\frac{\mathrm{PG}}{{\mathrm{GO}}_1}\right)=\arctan \left(\frac{\mathrm{XC}/2}{\sqrt{R^2-1/4{\mathrm{XC}}^2}}\right)$

Therefore $2A=2\arctan \left(\frac{\mathrm{XC}/2}{\sqrt{R^2-1/4X{C}^2}}\right)---\left(1\right)$

2.. determine on the workpiece to be machined arc surface on the same circular arc that arbitrarily processing stand P is to the distance of pivot, coordinate and the initial angle E (in order to write and to read conveniently, the P point just represents with X and Z at the component of X and Z-direction) of processing stand P:

P point (being OP) component of Z direction in coordinate system is:

Z＝OG＝OD+O ₁D-O ₁G＝L+R-O ₁P cos(A)＝L+R-Rcos(A)

Be Z=L+R-Rcos (A) (2)

P point (being OP) component of directions X in coordinate system is: X=O ₁Psin (A)

Be X=Rsin (A) (3)

The value of initial angle E is: E=arctan (X/Z) (4)

Workpiece to be machined arbitrfary point (on the same circular arc) to the distance of pivot is:

$\mathrm{OP}=\sqrt{X^2+Z^2}---\left(5\right)$

3.. the P point transformation arrives the coordinate that P ' puts after calculating pivot anglec of rotation A:

When the P point through the rotation transformation of B axle to P ' when point, the angle of B axle rotation is A, P and P ' they are 2 points on the same circumference take O as the center of circle, therefore OP=OP ', at this moment

P ' some component of Z direction in coordinate system is: Z ₁=OP ' cos (A+E)=OPcos (A+E)

P ' some component of directions X in coordinate system is: X ₁=OP ' sin (A+E)=OPsin (A+E)

(2). set cyclic variable

If angle step K=0.1, circulation initial value N=0, until $N=\frac{2A}{K},$ Be defined in the angle of reference axis Z below for negative, then anglec of rotation B1=-A+N*K.

(3). workpiece type groove circular curve is resolved into several processing stands, calculate coordinate figure and the anglec of rotation of obtaining each processing stand according to above-mentioned model.

(4). coordinate figure, the anglec of rotation of above-mentioned each processing stand are weaved into the NC program according to the model of lathe, import the control system of numerical control machining center, just can process bacterial type blade root circular arc type groove.

Add man-hour, rough mill first, just process the end point D (seeing Fig. 6) of removing from mould groove when rough milling, take end point D as benchmark, with the blade clamping on rotary table.Finish-milling is rotated by the main shaft drives milling cutter again; Drive blade rotation by rotary table, make the corresponding circumferential movement of leaf development, the axial width of the corresponding blade root of circumferential movement radian, by X-axis the position degree of rotary table on X-direction carried out Interpolation compensation, by Z axis the position degree of rotary table on Z-direction carried out Interpolation compensation, by the B axle angle of rotary table circumferential movement is carried out Interpolation compensation, make milling cutter when arbitrary processing stand cuts on the circular curve, generating tool axis vector is all on the normal of this processing stand, point to center of arc, thereby the relative movement orbit that makes workpiece and milling cutter is circular arc, the direction of this circular arc is just in time opposite with rotary table circular arc that movement locus forms, the two phase difference of pi radian., can find out from Fig. 3, Fig. 4, Fig. 5, turntable need rotate the circular arc aa ' that orthodrome AA ' could process the removing from mould groove.Milling cutter is selected the carbide alloy profile milling cutter, so just can improve the rotating speed of main shaft, thereby improves working (machining) efficiency.After processing the type groove, will not pull down other faces that just can process blade root by workpiece, so just avoid the damage of secondary clamping to machined surface.

Referring to Fig. 7, the flow process of specifically programming is as follows:

1) analyzes processing object (bacterial type blade root), workbench (pivot, clamping workpiece method), find out pivot B to the distance L on processed bacterial type blade root circular arc summit, the radius R of processed bacterial type blade root and chord length XC.

2) set up corresponding data relationship by these given datas, because be to obtain a lot of points with the convergence method, when processing stand infinitely segmented, therefore the chord length of adjacent processing stand can realize the arc machining of bacterial type blade root also with regard to the convergence arc length.

＜a 〉, determine first that according to the required precision of bacterial type blade root the step-length of worktable rotary is the program cycle parameter.

The precision K of hypothesis bacterial type blade root is 0.1um now, and the central angle of processed bacterial type blade root is J=2A=2 ∠ PO ₁D, the angle that is defined in the Z axis below is negative value, so have:

J=360/ (2*PI) * 2*Atn ((XC/2)/Sqr (R*R-(XC/2) * (XC/2)))=2A, loop parameter N=J/K then, therefore

Pz＝L+R-R*Cos((-A)*(2*PI/360)+N*K*(2*PI/360))

Px＝R*Sin((-A)*(2*PI/360)+N*K*(2*PI/360))

$\mathrm{OP}=\sqrt{\mathrm{px}*\mathrm{px}+\mathrm{pz}*\mathrm{pz}}$

OP＝M

$M=\sqrt{\mathrm{px}*\mathrm{px}+\mathrm{pz}*\mathrm{pz}}$

∠POD＝E＝360/(2*PI)*arctan(Px/Pz)

∠P’OD＝E-A+N*K

∠P’OD＝B

B＝E-A+N*K

P’ _ZI＝M*Cos(B*(2*PI)/360)

P’ _XI＝M*Sin(B*(2*PI)/360)

＜b〉establish the initial value of cycle values N=0, carry out a secondary program, cycle values N just adds 1, until during cycle values N=J/K, circulation finishes, with all some output.

＜c〉these parameter values are weaved into the NC program according to the model of lathe, import the control system of numerical control machining center, just can get the circular arc type groove to bacterial type blade root and process.

One section NC program code the when the below processes a certain concrete size workpiece for using this compensation method:

T2

M06

N0G0G90G40G94G17G21G10G53

G00Z500.0

N4G0G90G15H1X-116.556 Y0B7.064

S120M3

N5G56Z200H2

M8

N6G1Z127.425 F100

M16

Z127.425 X-116.556 B7.064

Z127.627 X-114.915 B6.964

Z127.826 X-113.273 B6.864

Z128.023 X-111.63 B6.764

Z128.216 X-109.988 B6.664

Z128.407 X-108.344 B6.564

Z128.594 X-106.701 B6.464

Z128.779 X-105.057 B6.364

Z128.961 X-103.413 B6.264

Z129.140 X-101.769 B6.164

Z129.316 X-100.124 B6.064

Z129.490 X-98.479 B5.964

Z129.660 X-96.834 B5.864

Z129.828 X-95.188 B5.764

Z129.992 X-93.543 B5.664

Z130.154 X-91.896 B5.564

Z130.313 X-90.25 B5.464

Z130.469 X-88.603 B5.364

Z130.622 X-86.956 B5.264

Z130.773 X-85.309 B5.164

Z130.920 X-83.662 B5.064

Z131.065 X-82.014 B4.964

Z131.206 X-80.366 B4.864

Z131.345 X-78.718 B4.764

Z131.481 X-77.069 B4.664

Z131.614 X-75.42 B4.564

Z131.744 X-73.771 B4.464

Z131.872 X-72.122 B4.364

Z131.996 X-70.473 B4.264

Z132.118 X-68.823 B4.164

Z132.236 X-67.173 B4.064

Z132.352 X-65.523 B3.964

Z132.465 X-63.873 B3.864

Z132.575 X-62.223 B3.764

Z132.682 X-60.572 B3.664

Z132.787 X-58.921 B3.564

Z132.888 X-57.27 B3.464

Z132.987 X-55.619 B3.364

Z133.082 X-53.968 B3.264

Z133.175 X-52.316 B3.164

Z133.265 X-50.665 B3.064

Z133.352 X-49.013 B2.964

Z133.436 X-47.361 B2.864

Z133.517 X-45.709 B2.764

Z133.595 X-44.057 B2.664

Z133.671 X-42.404 B2.564

Z133.743 X-40.752 B2.464

Z133.813 X-39.099 B2.364

Z133.880 X-37.447 B2.264

Z133.944 X-35.794 B2.164

Z134.005 X-34.141 B2.064

Z134.063 X-32.488 B1.964

Z134.118 X-30.835 B1.864

Z134.171 X-29.181 B1.764

Z134.220 X-27.528 B1.664

Z134.267 X-25.875 B1.564

Z134.310 X-24.221 B1.464

Z134.351 X-22.567 B1.364

Z134.389 X-20.914 B1.264

Z134.424 X-19.26 B1.164

Z134.456 X-17.606 B1.064

Z134.486 X-15.952 B.964

Z134.512 X-14.299 B.864

Z134.536 X-12.645 B.764

Z134.556 X-10.991 B.664

Z134.574 X-9.337 B.564

Z134.589 X-7.683 B.464

Z134.601 X-6.029 B.364

Z134.610 X-4.375 B.264

Z134.616 X-2.721 B.164

Z134.619 X-1.067 B.064

Z134.620 X.588 B-.036

Z134.617 X2.242 B-.136

Z134.612 X3.896 B-.236

Z134.604 X5.55 B-.336

Z134.593 X7.204 B-.436

Z134.579 X8.858 B-.536

Z134.562 X10.512 B-.636

Z134.542 X12.166 B-.736

Z134.519 X13.82 B-.836

Z134.494 X15.474 B-.936

Z134.465 X17.127 B-1.036

Z134.434 X18.781 B-1.136

Z134.400 X20.435 B-1.236

Z134.363 X22.089 B-1.336

Z134.323 X23.742 B-1.436

Z134.280 X25.396 B-1.536

Z134.234 X27.049 B-1.636

Z134.185 X28.703 B-1.736

Z134.134 X30.356 B-1.836

Z134.079 X32.009 B-1.936

Z134.022 X33.662 B-2.036

Z133.962 X35.315 B-2.136

Z133.899 X36.968 B-2.236

Z133.833 X38.621 B-2.336

Z133.764 X40.273 B-2.436

Z133.692 X41.926 B-2.536

Z133.618 X43.578 B-2.636

Z133.540 X45.231 B-2.736

Z133.460 X46.883 B-2.836

Z133.376 X48.535 B-2.936

Z133.290 X50.187 B-3.036

Z133.201 X51.838 B-3.136

Z133.109 X53.49 B-3.236

Z133.015 X55.141 B-3.336

Z132.917 X56.792 B-3.436

Z132.816 X58.443 B-3.536

Z132.713 X60.094 B-3.636

Z132.606 X61.745 B-3.736

Z132.497 X63.395 B-3.836

Z132.385 X65.046 B-3.936

Z132.270 X66.696 B-4.036

Z132.152 X68.346 B-4.136

Z132.032 X69.995 B-4.236

Z131.908 X71.645 B-4.336

Z131.782 X73.294 B-4.436

Z131.652 X74.943 B-4.536

Z131.520 X76.592 B-4.636

Z131.385 X78.24 B-4.736

Z131.247 X79.889 B-4.836

Z131.106 X81.537 B-4.936

Z130.962 X83.185 B-5.036

Z130.816 X84.832 B-5.136

Z130.666 X86.479 B-5.236

Z130.514 X88.126 B-5.336

Z130.359 X89.773 B-5.436

Z130.200 X91.42 B-5.536

Z130.039 X93.066 B-5.636

Z129.876 X94.712 B-5.736

Z129.709 X96.358 B-5.836

Z129.539 X98.003 B-5.936

Z129.367 X99.648 B-6.036

Z129.191 X101.293 B-6.136

Z129.013 X102.937 B-6.236

Z128.832 X104.581 B-6.336

Z128.648 X106.225 B-6.436

Z128.461 X107.869 B-6.536

Z128.272 X109.512 B-6.636

Z128.079 X111.155 B-6.736

Z127.884 X112.797 B-6.836

Z127.685 X114.439 B-6.936

Z127.484 X116.081 B-7.036

G0 G90G15H0Z500.0

M09

M05

M30

When with vertical numerical control Cutter Body Processing with Machining Center blade root type groove, two linear motion axis are Y-axis and Z axis, and rotating shaft is the A axle.Only need that above-mentioned parameter is done corresponding conversion and still can process blade root circular arc type groove, its principle is consistent.

Claims (4)

1. the processing method of a slots on turbine rotor for mushroom-shaped blade roots on numerical control machining center, is used the type groove of molded line milling cutter milling blade root; Described numerical control machining center has two linear motion axis and a rotating shaft at least, and rotating shaft is rotation workbench of machine tool; Milling cutter is installed on the milling head of numerical control machining center main shaft, drives the milling cutter rotation by this axle; Described blade is fixed on the rotary table of numerical control machining center, and the radiation of blade is parallel with main shaft and by the worktable rotary center, blade root type channel opening is towards milling head; Drive blade rotation by rotary table, make the corresponding circumferential movement of leaf development, rotary table carries out Interpolation compensation to the angle of circumferential movement; Two linear motion axis are parallel with the bacterial type blade root central plane, the position degree of rotary table on this two linear axis direction carried out Interpolation compensation, make milling cutter when arbitrary processing stand cuts on the circular curve, generating tool axis vector is all on the normal of this processing stand, point to center of arc, thereby the relative movement orbit that makes workpiece and milling cutter is circular arc, and the direction of this circular arc is just in time opposite with rotary table circular arc that movement locus forms, the two phase difference of pi radian.

2. the processing method of slots on turbine rotor for mushroom-shaped blade roots according to claim 1, it is characterized in that, the concrete grammar of described Interpolation compensation is: with blade rotary table in place fixing after, measure the concrete dimensional parameters of blade root type groove, in programming software, set up bacterial type blade root type channel mould type according to parameter value, write again procedure, program is imported Digit Control Machine Tool after, can process the type groove of bacterial type blade root.

3. the processing method of slots on turbine rotor for mushroom-shaped blade roots according to claim 1 is characterized in that, the concrete grammar of described control and compensation comprises step:

(1). set up the Mathematical Modeling of compensation control;

1.. calculate the central angle 2A of workpiece to be machined type groove according to known parameters

Pivot is to the distance L on blade root type groove circular arc summit;

The radius R of processed circular arc;

The chord length XC of processed circular arc;

These parameters have following geometrical relationship:

L＝OD；R＝O ₁D＝O ₁P；XC＝CP＝2PG；2A＝∠PO ₁C；

tan(A)＝PG/GO ₁；PG＝(1/2)×(XC)；

$G{O}_1=\sqrt{O_1{P}^2-P{G}^2}=\sqrt{R^2-1/4X{C}^2};$

$A=\arctan \left(\frac{\mathrm{PC}}{G{O}_1}\right)\arctan \left(\frac{\mathrm{XC}/2}{\sqrt{R^2-1/4X{C}^2}}\right)$

2.. determine that arbitrfary point P on the same circular arc of workpiece to be machined arc surface is to the distance of pivot, coordinate and the initial angle E of some P:

P point (being OP) component of Z direction in coordinate system is:

Z＝OG＝OD+O ₁D-O ₁G＝L+R-O ₁Pcos(A)＝L+R-Rcos(A)

Be Z=L+R-Rcos (A) (2)

P point (being OP) component of directions X in coordinate system is: X=O ₁Psin (A)

Be X=Rsin (A) (3)

The value of initial angle E is: E=arctan (X/Z) (4)

The P point to the distance of pivot is:

$\mathrm{OP}=\sqrt{X^2+Z^2}---\left(5\right)$

3.. the P point transformation arrives the coordinate that P ' puts after calculating pivot anglec of rotation A:

When the P point through the rotation transformation of B axle to P ' when point, the angle of B axle rotation is A, P and P ' they are 2 points on the same circumference take O as the center of circle, therefore OP=OP ', at this moment

P ' some component of Z direction in coordinate system is: Z ₁=OP ' cos (A+E)=OPcos (A+E)

P ' some component of directions X in coordinate system is: X ₁=OP ' sin (A+E)=OPsin (A+E)

(2). set cyclic variable

If angle step K=0.1, circulation initial value N=0, until $N=\frac{2A}{K},$ Be defined in the angle of reference axis Z below for negative, then anglec of rotation B1=-A+N*K;

(3). workpiece type groove circular curve is resolved into several processing stands, calculate coordinate figure and the anglec of rotation of obtaining each processing stand according to above-mentioned model;

(4). coordinate figure and the anglec of rotation of above-mentioned each processing stand are made the NC program according to the model of lathe, import the control system of numerical control machining center, just can process bacterial type blade root circular arc type groove.

4. the processing method of slots on turbine rotor for mushroom-shaped blade roots according to claim 1 is characterized in that, described milling cutter is the carbide alloy profile milling cutter.

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