CN103197601A - Cutter-shaft-swing five-coordinate numerical control machine tool pendulum length determination method - Google Patents

Abstract

The invention provides a cutter-shaft-swing five-coordinate numerical control machine tool pendulum length determination method. Coordinate values of a sphere center of a standard ball in the X-axis direction and the Y-axis direction of a machine coordinate system are confirmed when a swing angle of an A shape of a machine tool is theta i, and the i is 1, 2, ..., n. Variable quantity measured value and calculated value of the coordinate values of the sphere center of the standard ball in the Y-axis direction and the Z-axis direction when the swing angle of the A shaft of the machine tool is 0 degree. Then, a pendulum length parameter iteration initial value is used as an iteration codomain circle center, a machine tool spindle assembling accumulative error is used as the radius of the iteration codomain, and one tenth of processing accuracy is used as the iterative step length. Under the corresponding pendulum length parameters, n groups of variable quantity calculated values and quadratic sum of correspondence bias of the sum of the n groups of variable quantity calculated values are used as parameter indexes for judging the optimal pendulum length, and the minimum group of pendulum length parameters for judging the index values can be achieved after the iteration codomain is traversed. Compared with a general five-shaft linkage numerical control machine tool pendulum length algorithm and detection method, the method can obviously improve processing accuracy.

Description

Cutter shaft swing five-coordinate numerally controlled machine tool pendulum length assay method

Technical field

The present invention relates to the CNC processing technology field, be specially a kind of cutter shaft swing five-coordinate numerally controlled machine tool pendulum length assay method.

Background technology

Along with science and technology development and the people pursuit to high-quality product, the shape that constitutes product component becomes increasingly complex, and accuracy requirement is more and more higher.The processing of finishing as high precision complex parts such as impeller, blade, blisks that appears as of five-coordinate numerally controlled machine tool provides the necessary base guarantee.Five coordinate lathes are divided into: place revolution shaft type etc. on cutter shaft swing type, rotary table cradle-type, the rotary table, and wherein common with the cutter shaft swing type.The pendulum length of cutter shaft swing type five jig mills is defined as the handle of a knife end face to the distance of swing axis of rotation.Five-coordinate numerally controlled machine tool generally all has automatic following function, total calculate cutter by pendulum length is adding the cutter position of walking in man-hour to what is called exactly automatically.If there are deviation in pendulum length measured value and actual value, will cause skew and the distortion of machining locus, cause mismachining tolerance.

After the five coordinate lathe installations, most important link is measured pendulum length exactly.At present, traditional pendulum length measuring method is: determine pendulum length by oscillating spindle at the coordinate figure of 0 ° and 90 ° two specific position place correspondence.But the prerequisite that this method is measured is the actual centre of gyration of hypothesis main shaft to be overlapped with the theoretical centre of gyration, does not consider the biasing that revolving shaft exists in two shifting axle directions of Y, Z.And in the reality, the actual centre of gyration of main shaft and the theoretical centre of gyration often out of true overlap, and cause existing pendulum length measuring method to exist than mistake.

Summary of the invention

The technical matters that solves

For solving the problem that prior art exists, the present invention proposes a kind of cutter shaft swing five-coordinate numerally controlled machine tool pendulum length assay method, be under the different angles coordinate figure of reference point in lathe coordinate system (MCS) on the axis of swing by reading lathe turning axle A; And in conjunction with the geometric relationship of five-axis linkage machine tools each essential condition change in location in motion process, calculate the actual pendulum length of five-coordinate numerally controlled machine tool.

Technical scheme

Technical scheme of the present invention is:

Described a kind of cutter shaft swing five-coordinate numerally controlled machine tool pendulum length assay method is characterized in that: adopt following steps:

Step 1: select n different lathe A axle pendulum angle θ _i, i=1,2 ..., n, and θ _i∈ (0 °, 90) °; Described lathe A axle pendulum angle refers to that machine tool chief axis is around the pendulum angle of lathe coordinate system X-axis;

Step 2: the measured value of determining variable quantity:

Standard ball is clamped on the handle of a knife, and the ball centre of sphere that maintains the standard is put relative platen reference point and is maintained static, and measuring lathe A axle pendulum angle is 0 ° and θ _i, i=1,2 ..., during n, standard ball centre of sphere coordinate figure on Y, Z two direction of principal axis in lathe coordinate system; Calculating lathe A axle pendulum angle respectively is θ _i, i=1,2 ..., the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis during n, the variable quantity measured value of the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis when being 0 ° with lathe A axle pendulum angle

With

I=1,2 ..., n;

Step 3: the calculated value of determining variable quantity:

According to formula:

Determine that lathe A axle pendulum angle is θ _i, i=1,2 ..., the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis during n, the variable quantity calculated value of the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis when being 0 ° with lathe A axle pendulum angle

With

Wherein $L=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="L\; y"\; filenames="HDA00002880820200011.png,HDA00002880820200022.png"\; state="\{\{state\}\}">L</figure-callout>}}_y^{}+{\mathrm{<figure-callout\; id="2"\; label="L\; z"\; filenames="HDA00002880820200011.png,HDA00002880820200022.png"\; state="\{\{state\}\}">L</figure-callout>}}_z^{}},$ $\mathrm{\&beta;}=\mathrm{arctg}\left(\frac{L_y}{L_z+H}\right),$ H is machine tool length, L _yAnd L _zBe the pendulum length parameter, concrete L _yFor main shaft gyration center line on the lathe coordinate system Z-direction to the distance of main shaft gyration axis, L _zFor shank end face on the lathe coordinate system Y direction to the distance of main shaft gyration axis;

Step 4: determine pendulum length parameter iteration initial value:

Be axially perpendicular under the state of worktable upper surface at five coordinate machine tool chief axis, the cutter end face contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Z direction is Z ₁, cutter Y-direction cylinder contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Y-direction is Y ₁In under the state of worktable upper surface, the cutter cylinder contacts with the worktable reference point at five coordinate machine tool chief axis axially parallels, and machine tool numerical control system shows that the reading of Z direction is Z ₂The cutter end face contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Y-direction is Y ₂, obtain pendulum length parameter iteration initial value L _Z0With L _Y0For:

$L_{Z0}=\frac{1}{2}(Z_0+Y_0),$ $L_{y0}=\frac{1}{2}(Z_0-Y_0)$

Z wherein ₀=| (Z ₁-H)-(Z ₂-R) |, Y ₀=| (Y ₁-R)-(Y ₂-H) |, R is the machine tool radius;

Step 5: the pendulum length parameter iteration is optimized:

The pendulum length parameter iteration initial value that obtains with step 4 is the iteration codomain center of circle, with the radius of machine tool chief axis assembly accumulation error as the iteration codomain, with machining precision 1/10th as iteration step length, under corresponding pendulum length parameter, n group variable quantity calculated value

With

With n group variable quantity calculated value With The quadratic sum of corresponding deviation obtains one group of pendulum length parameter of judging quota value minimum for passing judgment on optimum pendulum length parameter index after the traversal iteration codomain.

Beneficial effect

A kind of cutter shaft swing five-coordinate numerally controlled machine tool pendulum length assay method that the present invention proposes shows that by cutter shaft digital control system under different pendulum angles relatively the variation (measured value) of Z axle and Y-axis coordinate figure measures with the variation (calculated value) that calculates by actual pendulum length and cutter shaft pendulum angle and determine five number of coordinates control milling machine pendulum lengths.This method can obviously improve machining precision than general 5-shaft linkage numerical control lathe pendulum length algorithm and detection method.

Description of drawings

Fig. 1: 5-shaft linkage numerical control lathe pendulum length parameter synoptic diagram;

Fig. 2: pendulum length synoptic diagram;

Fig. 3: pendulum length computational data measuring method synoptic diagram;

Fig. 4: pendulum length parameter detecting process flow diagram;

Fig. 5: pendulum length calculation of parameter process flow diagram;

Fig. 6: the pendulum length initial parameter value is determined synoptic diagram;

Wherein: 1 be machine tool chief axis 2 for main shaft gyration axle 3 for spindle centerline 4 for cutter 5 for worktable 6 for standard ball 7 for datum mark 8 for spindle swing to 0 ° 9 for the spindle swing angle to arbitrarily angled

Embodiment

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

By the geometric position variation relation of physical construction in the lathe machine motion process, accurately determine the swing axial length of 5-shaft linkage numerical control lathe in the present embodiment, can reach the arbitrary accuracy requirement of regulation.This method can judge easily whether the pendulum length parameter satisfies requirement on machining accuracy simultaneously.

The 5-shaft linkage numerical control lathe has shifting axle X, Y, Z and turning axle A, C, and worktable rotates to be the C axle around the Z axle; Main shaft is the A axle around the X-axis swing.Keep tool length (being called for short the long H of cutter) and cutter heart point (or centre of sphere point) invariant position, in A axle hunting range (0 °～90 °), get n non-0 ° and non-90 ° angle, each non-0 ° and non-90 ° corresponding standard ball centre of sphere of angle be when coordinate figure is rocked to 0 ° with respect to the A axle on Y, Z two direction of principal axis, and the variable quantity of coordinate figure is designated as Δ Y, Δ Z on each non-0 ° and the non-90 ° of corresponding standard ball centre of sphere of angle Y, Z two direction of principal axis.

Above-mentioned variable quantity can obtain by two kinds of methods:

Method one: at first, read the lathe display panel when the A axle swings to except 0 ° and 90 ° arbitrarily angle, the coordinate figure of Y, Z two direction of principal axis; Corresponding coordinate figure asks poor when being rocked to 0 ° with the A axle again.Method two: ask for by the geometric relationship that the machine tool mechanical structure motion is followed.What method one drew is measured value; What method two drew is calculated value.If when calculating is asked for, the pendulum length of employing equates with actual value or is very approaching that then measured value and calculated value should be in very little error ranges.Present embodiment principle is accordingly measured pendulum length.Ignoring under the situation of measuring error, in the machine tool mechanical structure actual motion process, the geometric relationship that A gets the interior pendulum length of [0 °, 90 °-β] scope and machine coordinate values variation satisfies following identical relation:

ΔZ＝L _z+H-L·sin(90°-θ-β)

ΔY＝L·cos(90°-θ-β)-L _Y

Wherein The measured value of coordinate figure variable quantity on Z axle, Y direction when formula equal sign left end is rocked to 0 ° for coordinate figure on the A axle the is rocked to arbitrarily angled back Z-direction with respect to the A axle; And the result of calculation of right of formula correspondence calculated value of coordinate figure variable quantity on Z axle, the Y direction when coordinate figure is rocked to 0 ° with respect to the A axle on the A axle is rocked to arbitrarily angled back Z axle, the Y direction.

In theory, the centre of gyration line of main shaft should be crossed main shaft gyration axle axle.But the mismachining tolerance when making owing to lathe often causes the center line of machine tool chief axis apart from the main shaft gyration axis certain distance to be arranged.Therefore, use the main shaft gyration center line on the distance (being defined as Lz) of main shaft gyration axis and the Z-direction of shank end face on the Y direction to describe pendulum length to the distance (being defined as Ly) of main shaft gyration axis, these two distance values are called as the pendulum length parameter.All be provided with the both direction parameter such as advanced digital control systems such as SIEMENS840D at pendulum length, to improve machine finish.

Concrete steps in the present embodiment are:

Step 1: select n different lathe A axle pendulum angle θ _i, i=1,2 ..., n, and θ _i∈ (0 °, 90) °; Described lathe A axle pendulum angle refers to that machine tool chief axis is around the pendulum angle of lathe coordinate system X-axis; Get θ in the present embodiment _i=10 °, 25 °, 40 °, 55 °, 70 °.

Step 2: the measured value of determining variable quantity:

Standard ball is clamped in (error is less than 0.005 ㎜) on the handle of a knife, and the ball centre of sphere that maintains the standard is put relative platen reference point and is maintained static, and measuring lathe A axle pendulum angle is 0 ° and θ _i, i=1,2 ..., during n, standard ball centre of sphere coordinate figure on Y, Z two direction of principal axis in lathe coordinate system; Calculating lathe A axle pendulum angle respectively is θ _i, i=1,2 ..., the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis during n, the variable quantity measured value of the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis when being 0 ° with lathe A axle pendulum angle

With

I=1,2 ..., n;

A axle pendulum angle θ in the present embodiment _i=10 °, 25 °, 40 °, 55 °, 70 ° is that 0 ° measured value table is as shown in the table with A axle pendulum angle:

The measured value table

Step 3: the calculated value of determining variable quantity:

According to formula:

Determine that lathe A axle pendulum angle is θ _i, i=1,2 ..., the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis during n, the variable quantity calculated value of the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis when being 0 ° with lathe A axle pendulum angle

With

Wherein $L=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="L\; y"\; filenames="HDA00002880820200011.png,HDA00002880820200022.png"\; state="\{\{state\}\}">L</figure-callout>}}_y^{}+{\mathrm{<figure-callout\; id="2"\; label="L\; z"\; filenames="HDA00002880820200011.png,HDA00002880820200022.png"\; state="\{\{state\}\}">L</figure-callout>}}_z^{}},$ $\mathrm{\&beta;}=\mathrm{arctg}\left(\frac{L_y}{L_z+H}\right),$ H is machine tool length, L _yAnd L _zBe the pendulum length parameter, concrete L _yFor main shaft gyration center line on the lathe coordinate system Z-direction to the distance of main shaft gyration axis, L _zFor shank end face on the lathe coordinate system Y direction to the distance of main shaft gyration axis;

Step 4: determine pendulum length parameter iteration initial value:

Be axially perpendicular under the state of worktable upper surface at five coordinate machine tool chief axis, the cutter end face contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Z direction is Z ₁, cutter Y-direction cylinder contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Y-direction is Y ₁In under the state of worktable upper surface, the cutter cylinder contacts with the worktable reference point at five coordinate machine tool chief axis axially parallels, and machine tool numerical control system shows that the reading of Z direction is Z ₂The cutter end face contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Y-direction is Y ₂, obtain pendulum length parameter iteration initial value L _Z0With L _Y0For:

$L_{Z0}=\frac{1}{2}(Z_0+Y_0),$ $L_{y0}=\frac{1}{2}(Z_0-Y_0)$

Z wherein ₀=| (Z ₁-H)-(Z ₂-R) |, Y ₀=| (Y ₁-R)-(Y ₂-H) |, R is the machine tool radius;

Pendulum length parameter iteration initial value is as shown in the table in the present embodiment:

Pendulum length initial parameter value list Wei ㎜

Then in the present embodiment, when the pendulum length parameter is got initial value, A axle pendulum angle θ _i=10 °, 25 °, 40 °, 55 °, 70 ° is that 0 ° calculated value table is as shown in the table with A axle pendulum angle:

Pendulum length initial parameter value check list position ㎜

Step 5: the pendulum length parameter iteration is optimized:

The pendulum length parameter iteration initial value that obtains with step 4 is the iteration codomain center of circle, with the radius of machine tool chief axis assembly accumulation error as the iteration codomain, with machining precision 1/10th as iteration step length, under corresponding pendulum length parameter, n group variable quantity calculated value

With

With n group variable quantity calculated value

With

The quadratic sum of corresponding deviation obtains one group of pendulum length parameter of judging quota value minimum for passing judgment on optimum pendulum length parameter index after the traversal iteration codomain.

Recording used five coordinate lathe iteration radiuses in the present embodiment is 0.03 ㎜, and iteration step length is 0.001 ㎜.Iterative computation is as a result shown in the following table:

Interative computation is Dan Wei ㎜ as a result

Claims (1)

1. a cutter shaft is swung five-coordinate numerally controlled machine tool pendulum length assay method, it is characterized in that: adopt following steps:

Step 1: select n different lathe A axle pendulum angle θ _i, i=1,2 ..., n, and θ _i∈ (0 °, 90 °); Described lathe A axle pendulum angle refers to that machine tool chief axis is around the pendulum angle of lathe coordinate system X-axis;

Step 2: the measured value of determining variable quantity:

Standard ball is clamped on the handle of a knife, and the ball centre of sphere that maintains the standard is put relative platen reference point and is maintained static, and measuring lathe A axle pendulum angle is 0 ° and θ _i, i=1,2 ..., during n, standard ball centre of sphere coordinate figure on Y, Z two direction of principal axis in lathe coordinate system; Calculating lathe A axle pendulum angle respectively is θ _i, i=1,2 ..., the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis during n, the variable quantity measured value of the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis when being 0 ° with lathe A axle pendulum angle

With

I=1,2 ..., n;

Step 3: the calculated value of determining variable quantity:

According to formula:

Determine that lathe A axle pendulum angle is θ _i, i=1,2 ..., the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis during n, the variable quantity calculated value of the coordinate figure of the standard ball centre of sphere on lathe coordinate system Y, Z two direction of principal axis when being 0 ° with lathe A axle pendulum angle

With

Wherein $L=\sqrt{L_y^2+L_z^2},$ $\mathrm{\&beta;}=\mathrm{arctg}\left(\frac{L_y}{L_z+H}\right),$ H is machine tool length, L _yAnd L _zBe the pendulum length parameter, concrete L _yFor main shaft gyration center line on the lathe coordinate system Z-direction to the distance of main shaft gyration axis, L _zFor shank end face on the lathe coordinate system Y direction to the distance of main shaft gyration axis;

Step 4: determine pendulum length parameter iteration initial value:

Be axially perpendicular under the state of worktable upper surface at five coordinate machine tool chief axis, the cutter end face contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Z direction is Z ₁, cutter Y-direction cylinder contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Y-direction is Y ₁In under the state of worktable upper surface, the cutter cylinder contacts with the worktable reference point at five coordinate machine tool chief axis axially parallels, and machine tool numerical control system shows that the reading of Z direction is Z ₂The cutter end face contacts with the worktable reference point, and machine tool numerical control system shows that the reading of Y-direction is Y ₂, obtain pendulum length parameter iteration initial value L _Z0With L _Y0For:

$L_{Z0}=\frac{1}{2}(Z_0+Y_0),$ $L_{y0}=\frac{1}{2}(Z_0-Y_0)$

Z wherein ₀=| (Z ₁-H)-(Z ₂-R) |, Y ₀=| (Y ₁-R)-(Y ₂-H) |, R is the machine tool radius;

Step 5: the pendulum length parameter iteration is optimized:

The pendulum length parameter iteration initial value that obtains with step 4 is the iteration codomain center of circle, with the radius of machine tool chief axis assembly accumulation error as the iteration codomain, with machining precision 1/10th as iteration step length, under corresponding pendulum length parameter, n group variable quantity calculated value

With

With n group variable quantity calculated value

With

The quadratic sum of corresponding deviation obtains one group of pendulum length parameter of judging quota value minimum for passing judgment on optimum pendulum length parameter index after the traversal iteration codomain.

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