CN101109033A - Method of controlling photospheric facula position when laser hardening on side curved surface - Google Patents

Abstract

The invention relates to a rectangular laser spot configuration control approach when laser quenching on a workpiece side curved surface on a four-axis 3 D laser machine processing machine. The approach deals with the three technical conditions when the rectangular laser spot scans along the workpiece side curved surface. Firstly, the specific rectangular spot is required to scan along the scheduled side curved surface, namely the tracking condition. Secondly the rectangular spot is required to keep the same relative tangential linear speed when it scans along the scheduled side curved surface, namely the uniform speed condition. Finally the laser beam is required to point in the normal direction of each spots along the side curved surface, namely the direction condition. To satisfy these three conditions, the invention controls the displacement x0 when the workpiece moves along the x0 axis with the laser processing machine, the angular displacement Phi when the workpiece rotates along the rotary table's axis A, the displacement z0when the laser head moves along the z0 axis and the synchronous moving speed vi when the three axis (z0, x0 and A) linkage. By controlling the above, the invention can effectively control the rectangular laser spot configuration. The implementation of the invention has opened a new applying scope of the laser quenching technique along workpiece side curved surface.

Description

The control method of photospheric facula position when laser hardening on side curved surface

Technical field

The present invention relates to a kind of on four axle linkage laser process machines during to N-Side surf laser quenching, rectangular light spot when N-Side surf scans the position and the control method of attitude (abbreviation pose).

Background technology

The major equipment that laser quenching relates to has: laser apparatus, can carry out beam treatment, obtain the specific light shape of spot light-conducting system, can be along vertical axis z ₀The laser Machining head of doing to adjust up and down, workpiece motion s system (also claiming laser process machine) and the digital control system that can control AC servo motor.

Wherein, laser process machine respectively can be along x by relative support ₀, y ₀Upper and lower worktable that axle (diaxon is vertical) moves and the compositions such as rotary table that can rotate around axle A.The rotating element of turntable has three-jaw or four-jaw chuck, is used for clamping work pieces and workpiece is rotated around the A axle.Four each by an AC servo machinery driving, and can realize any three (as x ₀, z ₀With the A axle) interlock.x ₀, y ₀And z ₀Axle is formed a right-handed coordinate system o who connects firmly with support ₀-x ₀y ₀z ₀(abbreviation lathe coordinate system).During laser quenching, can make A axle and y ₀Axle is parallel and forward is consistent, and the quenching N-Side surf of workpiece is bus and y ₀The cylinder that axle is parallel, the directrix of cylinder (following abbreviation side curve) is positioned at and x ₀o ₀z ₀In the plane of plane parallel.The workpiece that is clamped on the rotary table chuck can be done three motions in company with laser process machine: along x ₀, y ₀Axle move and around the rotation of A axle.

When adopting the uniform rectangular light spot of power density to carry out laser quenching, the method for quenching workpiece side curve is vowed and laser beam irradiation direction (z ₀Direction) coincide, the center of laser rectangular light spot is at z ₀On the axle, the length direction of rectangular light spot is all the time along y ₀Direction.When the laser process machine band workpiece and made controlled motion, laser beam just scanned required quenching zone on the workpiece side curved surface.How synchronously to control three (z ₀, x ₀With the A axle) interlock, make laser beam on the N-Side surf of workpiece, scan width and all constant uniform hardening band of layer depth is a gordian technique with theory significance and practical value.

Before in May, 2006, the applicant is the theme with " laser quenching " that speech has carried out looking into newly in all places data resource system, patent and paper retrieval, and result for retrieval is as follows:

1. update search

Retrieve 23 latest domestic scientific and technological achievements altogether.Wherein, there is not a scientific and technological achievement close with the art of this patent.

2. patent retrieval

Retrieve 8 patents of invention altogether.Wherein, there is not a patent of invention close with the art of this patent.

3. paper retrieval

Retrieve 145 pieces of relevant papers altogether.Wherein, there is not a paper close with the art of this patent.The applicant does not see the foreign literature close or identical with the art of this patent yet.

Summary of the invention

The objective of the invention is a technical barrier in order to solve on the three-shaft linkage laser process machine to the laser quenching of workpiece side curved surface, provide a kind of control method, so that the relative workpiece of rectangular light spot scans width and all uniform high quality quenching zone of layer depth with appropriate pose on the workpiece side curved surface to the laser process machine three-shaft linkage.

@ is constant and under preconditions such as rectangular light spot inner laser power density distribution is even at laser output power, for on the N-Side surf of workpiece, scanning all constant high quality quenching zone of width and layer depth, the expection pose of rectangular light spot should satisfy three technical qualification: the length and the width of the rectangular light spot that forms on the workpiece side curved surface are constant, and the center of this rectangular light spot (can be considered a fixed point on the optical axis, is designated as G _C) must be along side curved scanning predetermined on the workpiece, this is a tracking condition; Specific rectangular light spot center G _CTangential relatively linear velocity size on workpiece during the predetermined side curved scanning is constant, and this i.e. condition at the uniform velocity; (its direction of illumination is-z laser beam ₀Direction) must be along the normal direction irradiation at predetermined side curve each point place on the workpiece, this is the direction condition.

For satisfying three technical qualification of the relative workpiece of above-mentioned rectangular light spot along side curve Pose Control, the technical scheme that we adopted is: to workpiece during in company with the laser machine bed motion along x ₀The displacement x of axle ₀With the angular displacement  that rotates around rotary table axis A, laser Machining head along z ₀The displacement z of axle ₀, and three (z ₀, x ₀With the A axle) the synchronous movement speed v in when interlock _iControl effectively.

Be located among the workpiece coordinate system zox that connects firmly mutually with plane, workpiece quenching side curve place, the parametric equation of quenching side curve l is

$\left\{\begin{array}{c}z=z\left(\mathrm{\θ}\right)\\ x=x\left(\mathrm{\θ}\right)\end{array}\right.,{\mathrm{\θ}}_0\≤\mathrm{\θ}\≤{\mathrm{\θ}}_e---\left(1\right)$

In the formula, θ ₀And θ _eBe respectively a luminous point M of laser quenching ₀With whole luminous point M _eParameter value.

Add man-hour, three (z of laser process machine beginning to quench ₀, x ₀With the A axle) displacement z ₀, x ₀All be made as zero with , then as the constant rectangular light spot center G of size _CBeing scanned up to quenching side curve l goes up arbitrfary point M and satisfies above-mentioned tracking condition and during the direction condition, the three-shaft displacement amount z of laser machine tool ₀, x ₀Can calculate by following three formulas of finding by the applicant with .

Laser Machining head is along z ₀The line shift z that axle moves ₀Calculating formula:

z ₀＝ucos(α ₀+)+vsin(α ₀+) (2)

Upper table is along x ₀The line shift x that axle moves ₀Calculating formula:

x ₀＝vcos(α ₀+)-usin(α ₀+) (3)

The calculating formula of the angular travel  that rotary table rotates around axis A:

In the formula, α ₀Be that quenching side curve l has gone up luminous point M ₀Place's per unit system is vowed Angle with z axle forward; (n _z, n _x) be that quenching side curve l goes up any point M place per unit system arrow

Coordinate in workpiece coordinate system zox;

u＝z(θ)-O _0zcos-O _0xsin

v＝-x(θ)-O _0zsin+O _0xcos``

Wherein, O ₀Z=z (θ ₀), O _0x=x (θ ₀) be luminous point M ₀At workpiece is coordinate among the zox.

Synchronous movement speed v _iDefinite method:

For satisfying the uniform speed scanning condition, should control three (z ₀, x ₀With the A axle) the synchronous movement speed v in when interlock _iv _iCan calculate by following method.At first require to determine rectangular light spot center G according to laser power and quenching layer depth etc. _CThe relative tangential linear velocity v of workpiece when quenching side curve l scans _C(abbreviation quenching velocity), according to the accuracy requirement of edge quenching side curve l scanning etc. with whole quenching side curve l from luminous point M ₀To whole luminous point M _eBe divided into n section (being called for short n is the quenching segments), point scoring M ₀, M ₁..., M _n=M _eCalculate the coordinate (z of each branch according to the equation (1) of side curve l _i, x _i) and each arc length of sub section $\mathrm{\Δ}{S}_i=\sqrt{{(z_{i+1}-z_i)}^2+{(x_{i+1}-x_i)}^2}$ , the time of then scanning each son section is Δ t _i=Δ S _i/ v _C

Calculate by above-mentioned formula (2)～formula (4) and to scan arbitrary branch M _I+1The time three-shaft displacement amount z _{0, i+1}, x _{0, i+1}And  _I+1And from M _iSpot scan is to M _I+1Three-shaft displacement increment Delta z during point _i=z _{0, i+1}-z _{0, i}, Δ x _i=x _{0, i+1}-x _{0, i}, Δ  _i= _I+1- _i, then during three-shaft linkage from M _iSpot scan is to M _I+1Need the synchronous translational speed of control in the point process $v_i=\sqrt{{\mathrm{\Δz}}_i^2+{\mathrm{\Δx}}_i^2}/{\mathrm{\Δt}}_i$ (i＝0，1，...，n-1)。

In fact, realize satisfying the three-shaft linkage of above-mentioned three technical qualification on general laser process machine, width and all constant high quality quenching zone of layer depth are very complicated motion control problems on the workpiece side curved surface to obtain.The present invention has successfully solved this difficult problem theoretically with in the practice, has filled up a blank in the laser quenching technology.

Description of drawings

Fig. 1 is a light spot posture during laser quenching control method operational flowchart of the present invention.

Embodiment

Further specify method of the present invention below in conjunction with accompanying drawing.

As shown in Figure 1, the concrete implementation step of the inventive method is:

1, three-shaft displacement increment Delta z _i, Δ x _i, Δ  _iWith synchronous movement speed v _iCalculating;

2, the digitizing of numerical control program programming;

3, the optical position setting is installed and risen to workpiece;

4, hardening step, executive control program.

The 1st step three-shaft displacement increment of flow process and the computation process of synchronous translational speed are:

1) in workpiece coordinate system zox, writes out the parametric equation of quenching side curve l;

2) require to have determined luminous point M according to quench requirement, continuous quenching etc. ₀With whole luminous point M _e,, calculated luminous point M with computer advanced language (as formula translation etc.) factorization ₀Coordinate (O _0z, O _0x), per unit system is vowed

Coordinate (n _0z, n _0x),

Angle α with z axle forward ₀

3) require to determine quenching velocity v according to laser power, quenching hardness and quenching layer depth etc. _C, according to definite quenching segments n such as accuracy requirement of edge quenching side curve l scanning, point scoring M ₀, M ₁..., M _n=M _e, calculate the coordinate (z of each branch with program _i, x _i), arc length of each son section $\mathrm{\Δ}{S}_i=\sqrt{{(z_{i+1}-z_i)}^2+{(x_{i+1}-x_i)}^2}$ And the required time Δ t of each son section of scanning _i=Δ S _i/ v _C

4), calculate from luminous point M with program according to formula (2)～formula (4) ₀Scan arbitrary branch M _I+1The time three-shaft displacement amount z _{0, i+1}, x _{0, i+1}And  _I+1And from M _iSpot scan is to M _I+1Three-shaft displacement increment Delta z during point _i=z _{0, i+1}-z _{0, i}, Δ x _i=x _{0, i+1}-x _{0, i}, Δ  _i= _I+1- _i, and during three-shaft linkage from M _iSpot scan is to M _I+1Need the synchronous translational speed of control in the point process $v_i=\sqrt{{\mathrm{\Δz}}_i^2+{\mathrm{\Δx}}_i^2}/{\mathrm{\Δt}}_i$ (i＝0，1，...，n-1)；

5) with Δ z _i, Δ x _i, Δ  _iAnd v _i(i=0,1 ..., value n-1) is stored in the two-dimensional array.

The process of the digitizing programming of the 2nd step number control program of flow process is:

According to being provided with of special-purpose language, prescribed form and the digital control system of aforementioned calculation result, G code etc., directly utilize the aforementioned calculation program with textual form output Δ z _i, Δ x _i, Δ  _iAnd v _i(i=0,1 ..., value n-1) also generates the G code numerical control program automatically.

Whole calculating and programming can be carried out off-line programing on computers with High-Level Language.In the G code numerical control program that generates automatically, need not call any built-in function in the G code, do not do any calculating, directly carry out numerical control program, just can realize real-time control to the workpiece compound movement.This programmed method is called the digitizing programming method.

The action that the optical position setting was installed and risen to the 3rd step workpiece of flow process is:

1) numerical control program is sent in the internal memory of laser process machine digital control system by the RS232 interface; A mark workpiece coordinate system zox and a luminous point M on workpiece ₀The position;

2) workpiece is installed

Workpiece is clamped with the chuck on the rotary table, the initial point that guarantees workpiece coordinate system zox on the axis A of rotary table, the y of A axle and lathe coordinate system ₀Axle is parallel and forward is consistent, the y of plane, workpiece quenching side curve l place (being the zox plane) and lathe coordinate system ₀Axle is perpendicular;

3) playing optical position sets

Rotate rotary table, make the x axle of workpiece coordinate system zox and the x of lathe coordinate system ₀Axle is parallel and point to consistent; Make rotary table reverse α around its axis A ₀Angle has made luminous point M ₀Per unit system vow

Optical axis z with lathe ₀Axle is parallel; To play luminous point M at last ₀Move to optical axis z ₀On the axle, and the upper-lower position of adjustment laser Machining head, satisfy the defocusing amount of stipulating.This moment optical axis z ₀On the axle with play a luminous point M ₀The rectangular light spot center that coincides is above-mentioned described G _CThe point.

The action of the 4th step hardening step of flow process is:

After laser output power reached set(ting)value, executive control program just can make rectangular light spot scan width and all constant high quality quenching zone of layer depth on the N-Side surf of workpiece, finishes whole laser quenching process.

Implement example

Be example with the laser quenching of eccentric elliptic cam profile curved surface below, further illustrate above-mentioned three-shaft displacement increment and the calculating of translational speed synchronously and the method for digitizing programming.

If the parametric equation of the oval side curve of cam is:

$\left\{\begin{array}{c}z=a\cos \mathrm{\θ}+c\\ x=b\sin \mathrm{\θ}+d\end{array}\right.0\≤\mathrm{\θ}\≤2\mathrm{\π}$

Wherein, get semi-major axis α=110.0mm, minor semi-axis b=80.0mm, elliptical center coordinate c=50.0mm, d=20.0mm.

Get and play luminous point M surely ₀: θ ₀=0, whole luminous point M _e: θ _e=2 π, segments n=180, sweep velocity v _C=900mm/min.

According to above-mentioned digitizing programming process, earlier the program of working out with the Fortran language is calculated above-mentioned eccentric elliptic cam profile curve, must table 1 shown in the result.Wherein, the 2nd classifies the value of parameter θ as, and the 3rd, the 4th classifies the coordinate figure of each branch on the elliptical profile as, and (z, x), the 5th classifies the relative starting position of laser Machining head as along z ₀The line shift that axle moves, the 6th classifies the relative starting position of laser process machine as along x ₀The line shift that axle moves, the 7th classifies the angular travel that rotary table rotates around the A axle relative to the starting position as.According to the three-shaft displacement amount shown in the table 1, calculate three then corresponding to a M _I+1Displacement increment Δ z _i, Δ x _i, Δ  _iSynchronous movement speed v during with three-shaft linkage _i, and with Δ z _i, Δ x _i, Δ  _iAnd v _iValue be stored in the two-dimensional array (i=0,1 ..., n-1).

Table 2 is according to the three-shaft displacement increment Delta z that has tried to achieve _i, Δ x _i, Δ  _iSynchronous movement speed v during with three-shaft linkage _i(i=0,1 ..., the G code numerical control program that the cam profile curved surface is carried out laser quenching that value n-1) automatically generates with computation program: ELLIPSE.Wherein, the numeral of Z, X and A back is corresponding points M _I+1Displacement increment Δ z _i(mm), Δ x _i(mm) and Δ  _i(°) value, the numeral of F back is the synchronous movement speed v of required control _i(mm/min) (i=0,1 ..., n-1).

Table 1 calculation result table

I	θ (o)	z(mm)	x(mm)	z 0(mm)	x 0(mm)	 (o)
							0 1 2 3 4 5 6 7 8 9 10 … 171 172 173 174 175 176 177 178 179 180	.00000D+00 .20000D+01 .40000D+01 .60000D+01 .80000D+01 .10000D+02 .12000D+02 .14000D+02 .16000D+02 .18000D+02 .20000D+02 … .34200D+03 .34400D+03 .34600D+03 .34800D+03 .35000D+03 .35200D+03 .35400D+03 .35600D+03 .35800D+03 .36000D+03	.16000D+03 .15993D+03 .15973D+03 .15940D+03 .15893D+03 .15833D+03 .15760D+03 .15673D+03 .15574D+03 .15462D+03 .15337D+03 … .15462D+03 .15574D+03 .15673D+03 .15760D+03 .15833D+03 .15893D+03 .15940D+03 .15973D+03 .15993D+03 .16000D+03	.20000D+02 .22792D+02 .25581D+02 .28362D+02 .31134D+02 .33892D+02 .36633D+02 .39354D+02 .42051D+02 .44721D+02 .47362D+02 … -.47214D+01 -.20510D+01 .64625D+00 .33671D+01 .61081D+01 .88662D+01 .11638D+02 .14419D+02 .17208D+02 .20000D+02	.00000D+00 .84206D+00 .14470D+01 .18152D+01 .19498D+01 .18567D+01 .15446D+01 .10243D+01 .30817D+00 -.58960D+00 -.16540D+01 … -.16906D+02 -.14364D+02 -.11948D+02 -.96765D+01 -.75682D+01 -.56396D+01 -.39061D+01 -.23813D+01 -.10764D+01 .00000D+00	.00000D+00 .49048D+01 .98245D+01 .14728D+02 .19586D+02 .24368D+02 .29048D+02 .33601D+02 .38004D+02 .42237D+02 .46284D+02 … -.38758D+02 -.35216D+02 -.31439D+02 -.27442D+02 -.23242D+02 -.18859D+02 -.14317D+02 -.96409D+01 -.48588D+01 .00000D+00	.00000D+00 -.27490D+01 -.54921D+01 -.82234D+01 -.10937D+02 -.13628D+02 -.16292D+02 -.18923D+02 -.21518D+02 -.24073D+02 -.26586D+02 … -.33593D+03 -.33848D+03 -.34108D+03 -.34371D+03 -.34637D+03 -.34906D+03 -.35178D+03 -.35451D+03 -.35725D+03 -.36000D+03

Table 2 numerical control program

％_N_ELLIPSE_MPR

；$PATH＝/_N_MPF_DIR

N 5 G1 G91 G64

N 8 M7 M20

N 11 Z.84206 X 4.90478 A-2.749006 F1603.7475

N 12 Z.60498 X 4.91976 A-2.743064 F1595.6627

N 13 Z.36816 X 4.90379 A-2.731285 F1579.6311

N 14 Z .13456 X 4.85759 A-2.713876 F1555.9698

N 15 Z -.09304 X 4.78243 A-2.691135 F1525.1622

N 16 Z -.31209 X 4.68008 A-2.663441 F1487.8339

N 17 Z -.52038 X 4.55273 A-2.631240 F1444.7250

N 18 Z -.71609 X 4.40288 A-2.595025 F1396.6587

N 19 Z -.89777 X 4.23327 A-2.555327 F1344.5099

N 20 Z-1.06440 X 4.04676 A-2.512689 F1289.1743

………………………………………………………………

N181 Z 2.64981 X 3.29633 A-2.512689 F1303.0192

N182 Z 2.54225 X 3.54214 A-2.555327 F1354.6381

N183 Z 2.41596 X 3.77676 A-2.595025 F1403.7513

N184 Z 2.27112 X 3.99711 A-2.631240 F1449.4221

N185 Z 2.10833 X 4.20012 A-2.663441 F1490.7228

N186 Z 1.92863 X 4.38278 A-2.691135 F1526.7649

N187 Z 1.73349 X 4.54230 A-2.713876 F1556.7318

N188 Z 1.52481 X 4.67613 A-2.731285 F1579.9109

N189 Z 1.30490 X 4.78217 A-2.743064 F1595.7235

N190 Z 1.07637 X 4.85875 A-2.749006 F1603.7498

N200 M21 M9

N999 M2

Claims (5)

1. posture control method of rectangular light spot when on four axle linkage laser process machines the workpiece side curved surface being carried out laser quenching is characterized in that three technical qualification that rectangular light spot expection scanning pose should satisfy are:

(1) the center G of specific big or small rectangular light spot _CMust be along predetermined side curved scanning, i.e. tracking condition on the workpiece;

(2) specific rectangular light spot center G _CTangential relatively linear velocity size on workpiece during the predetermined side curved scanning is constant, i.e. condition at the uniform velocity;

(3) laser beam must be along the normal direction irradiation at predetermined side curve each point place on the workpiece, i.e. direction condition.

2. rectangular light spot posture control method during laser quenching according to claim 1 is characterized in that concrete step is:

(1) three-shaft displacement increment Delta z _i, Δ x _i, Δ  _iWith synchronous movement speed v _iCalculating;

(2) digitizing of numerical control program programming;

(3) the optical position setting is installed and risen to workpiece;

(4) hardening step, executive control program.

3. the rectangular light spot posture control method is characterized in that described three-shaft displacement increment Delta z during according to claim 1,2 described laser quenchings _i, Δ x _i, Δ  _iWith synchronous movement speed v _iMethod of calculation be:

(1) in workpiece coordinate system zox, writes out the parametric equation of quenching side curve;

(2) determine to rise on the quenching curve light starting point M ₀, whole luminous point M _eCoordinate, calculated luminous point M ₀Per unit system vow

Angle α with z axle forward ₀

(3) determine quenching velocity v _CWith quenching segments n, calculate the coordinate of each scanning spot and scan the time Δ t of each height section _i

(4) calculate from luminous point M ₀Scan arbitrary branch M _I+1The three-shaft displacement amount _{Z0, i+1}, x _{0, i+1}And  _I+1, from M _iSpot scan is to M _I+1The three-shaft displacement increment Delta z that when point is required _i=z _{0, i+1}-z _{0, i}, Δ x _i=x _{0, i+1}-x _{0, i}, Δ  _i= _I+1- _i, and the synchronous translational speed of required control during three-shaft linkage $v_i=\sqrt{\mathrm{\Δ}{z}_i^2+\mathrm{\Δ}{x}_i^2}/\mathrm{\Δ}{t}_i$ (i=0,1 ..., n-1); And with the three-shaft displacement increment and synchronously the value of translational speed be stored in the two-dimensional array.

4. rectangular light spot posture control method during according to claim 1,2 described laser quenchings is characterized in that the process of digitizing programming is:

With other computer advanced languages (as formula translation etc.) factorization, calculate three-shaft displacement increment Delta z _i, Δ x _i, Δ  _iWith synchronous movement speed v _i(i=0,1 ..., value n-1) and with textual form output calculation result; And, directly utilize this program to generate the G code numerical control program automatically according to the setting and the aforementioned calculation result of the special-purpose language of G code, prescribed form, digital control system.

5. rectangular light spot posture control method during according to claim 1,2 described laser quenchings is characterized in that the step that workpiece is installed and an optical position is set is:

(1) workpiece is installed---the chuck of workpiece with rotary table clamped, the initial point that guarantees workpiece coordinate system zox on turret axis A, the y of A axle and lathe coordinate system ₀Axle is parallel and forward is consistent, the y of plane, workpiece quenching side curve place (being the zox plane) and lathe coordinate system ₀Axle is perpendicular;

(2) playing optical position sets---and rotate rotary table, make the x axle of workpiece coordinate system zox and the x of lathe coordinate system ₀Axle is parallel and point to unanimity, makes rotary table reverse α around its axis A ₀Angle makes and plays luminous point M on the workpiece side curve ₀The per unit system at place is vowed

Z with lathe coordinate system ₀Axle is parallel; To play luminous point M at last ₀Move to optical axis z ₀On the axle, and the upper-lower position of adjustment laser Machining head, required rectangular light spot obtained.

Images