CN106197274A - A kind of digital measuring has the method for the scribe line position degree of the mould of curved surface - Google Patents

Abstract

The present invention provides the method for the scribe line position degree of the mould that a kind of digital measuring has curved surface, including step: (1) uses described laser tracker to set up the spherical coordinate system of groove of mould, determines the theoretical coordinate value of the centre of sphere of spherical coordinate system；(2) by the groove of the most advanced and sophisticated alignment mould of described supplemental measurement tool, then rotate the second end of described supplemental measurement tool, obtain at least 5 different coordinate figures measuring point by reflection sphere；(3) obtain surveying sphere by software matching, calculate the coordinate figure of the centre of sphere of actual measurement sphere；And the coordinate figure of the centre of sphere of calculating compares by (4) with the theoretical coordinate value of the centre of sphere, obtain the actual deviation of scribe line position degree.

Description

A kind of digital measuring has the method for the scribe line position degree of the mould of curved surface

Technical field

The invention belongs to aircraft industry large mold manufacture and field of measuring technique, be specifically related to a kind of digital measuring and have The method of the scribe line position degree of the mould of curved surface.

Background technology

In recent years in Aircraft Tools manufacturing industry, being increasingly employed frock Digitized manufacturing, mould is from the mould in past Digitized transmission, Digital manufacturing are gradually changed in analog quantity transmission, and the manufacture of mould instead of biography in digital transfer mode The manufacture of the model analog quantity transmission of system.The molding great majority of airplane parts all pass through rubber shaping mould, skin drawing mould, Perforating die, blanking die also have material mould again, and wherein the groove on mould is the benchmark to forming part cutting parts edge, and In aircraft industry, part lot is many, the least, so mould groove is the important processing foundation that part produces.

Due to part status change frequently, in frock, part groove also must correspondingly change, cause mould manufacturing and Reprocessing middle part groove workload big, processing link increases, and error probability increases the most accordingly, so to numerical control processing mold groove Accurately detect, to ensureing high accuracy frock quality important in inhibiting.Again along with the application of multiple material mould, the curved surface of mould Becoming increasingly complex, again due to the size span of mould increasing (reaching tens meters long), the detection means being currently known more is come More can not meet its accuracy requirement.

The mould tire groove method of inspection had in the past:

1. sample plate detection method: be applicable to the mould tire curved surface (cost is big, certainty of measurement is low) of complexity, need a set of difference The model of erect-position and a large amount of auxiliary mould are (such as bigger place and large platform, angle square board, standard ruler level indicator, theodolite Deng, the model manufacturing cycle is longer.

2. loft gelatin plate method: be applicable to the mould tire (trueness error is bigger) that curved surface is flatter, needs aerofoil complexity Three-dimensional digital-to-analogue changes into the expansion shape figure of two dimension, and manpower, time put into how making needs external coordination, and the cycle is the longest, and length is little, need to be with many Open gelatin plate split, for the groove inspection that mould tire trueness error is bigger.

3. joint arm measurement method: owing to the restriction of range can only measure mould groove less between 3 meters～5 meters, have Preferably accuracy of detection, but limited by range ability, bigger cumulative errors can be caused according to turning station (leapfroging), affect its detection Precision.

4. lathe on_line detection method: establishment detection program on-line checking on lathe, it is necessary to assure in manufacturing processing fashionable dress Folder its accuracy of detection of state consistency guarantee, and mainly by visual detection, it is impossible to digital quantization, has certain restricted.

5. laser tracker detection method: laser tracker can be by measuring level to the measurement of coordinates of extraterrestrial target Angle, vertical angle and oblique distance, then be can be obtained by the three-dimensional coordinate X of spatial point, Y, Z by spherical coordinates or polar coordinate measurement principle. In spherical coordinates measurement system, if the center of rotation of tracker is O point, the central point of tested target mirror is P point, compiles by two angles Vertical angle beta and horizontal angle α of P point measured respectively by code device, draws d by the distance of laser interferometer measurement O point to P point, then P point Coordinate (X, Y, Z) be easy to be calculated by β, α and d:

But, laser tracker detection method can not detect scribe line position precision at present.

Feature and the shortcoming of above-mentioned each method are summarized as follows:

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the invention provides one and utilize homemade aid, be applied to A kind of groove detection method that mould groove is taken a little and analyzes by laser tracker detection equipment.

Specifically, the method for the scribe line position degree according to the digital measuring of the present invention with the mould of curved surface uses laser Tracker and supplemental measurement tool, described laser tracker includes reflection sphere and supports the reflection sphere pedestal of reflection sphere, described auxiliary Helping survey tool to include having cuspidated first end and have the second end of the central recess accommodating described reflection sphere pedestal, it is special Levying and be, described method includes step:

(1) use described laser tracker to set up the spherical coordinate system of groove of mould, determine the reason of the centre of sphere of spherical coordinate system Opinion coordinate figure；

(2) by the groove of the most advanced and sophisticated alignment mould of described supplemental measurement tool, described supplemental measurement tool is then rotated Second end, obtains at least 5 different coordinate figures measuring point by reflection sphere；

(3) obtain surveying sphere by software matching, calculate the coordinate figure of the centre of sphere of actual measurement sphere；And

(4) coordinate figure of the centre of sphere of calculating is compared with the theoretical coordinate value of the centre of sphere, obtain the actual inclined of scribe line position degree Difference.

Wherein, described laser tracker is Leica laser tracker.

Wherein, (a, b, c) be the sphere centre coordinate after matching to some o, and some O (A, B, C) be theory sphere centre coordinate, its large deviations For:

$L=\sqrt{{(A-a)}^2+{(B-b)}^2+{(C-c)}^2}.$

Compared with prior art, the invention has the beneficial effects as follows that realization can meet large mold (more than 10 meters) graduating accuracy The digitizing detection method required.

Accompanying drawing explanation

The further feature of the present invention and advantage are by more preferable for the preferred implementation by describing in detail below in conjunction with accompanying drawing Ground understands, wherein:

Fig. 1 shows the schematic diagram of the supplemental measurement tool that the method according to the invention used；

Fig. 2 shows the schematic diagram of the method according to the invention location survey amount point really；

Fig. 3 shows another schematic diagram of the method according to the invention location survey amount point really；

Fig. 4 shows the actual measurement sphere that the method according to the invention obtains.

Detailed description of the invention

In the specific descriptions of following preferred embodiment, by with reference to constituting the accompanying drawing appended by a present invention part.Institute Attached accompanying drawing has been illustrated by way of example and has been capable of specific embodiment.The embodiment of example is not intended as Limit is according to all embodiments of the present invention.It is appreciated that without departing from the scope of the present invention, it is possible to use other Embodiment, it is also possible to carry out the structural or amendment of logicality.

As shown in Figures 1 to 3, the method according to the invention uses laser tracker (not shown) and supplemental measurement tool. The concrete structure of laser tracker and use step to it is known to the person skilled in the art that in Fig. 1 only symbolically Show the reflection sphere 10 of laser tracker and support the reflection sphere pedestal 20 of reflection sphere 10, the Magnet in reflection sphere pedestal 20 Ensure to be supported on identical position reflection sphere 10.Supplemental measurement tool according to the present invention includes first with most advanced and sophisticated 31 End 30 and second end 40 with central recess 41, the reflection sphere pedestal 20 of laser tracker is contained in central recess 41.

1. use laser tracker to set up the spherical coordinate system of groove of mould, determine the theoretical coordinate of the centre of sphere of spherical coordinate system Value.

2., after establishment of coordinate system completes, it is installed to assist work by reflection sphere 10 and the reflection sphere pedestal 20 of laser tracker In tool, the tip 31 of aid is directed at the test point of mould groove, obtains first eyeball (such as Fig. 2).

3. with groove test point o be the center of circle rotate aid the second end, spatially obtain second eyeball (as Fig. 2).

The most in the same way, spatially obtain eyeball 1, eyeball 2, eyeball 3, eyeball 4, eyeball 5, To at least 5 group coordinate figures (such as Fig. 3).

5. because of test point o, (a, b, c) distance to each eyeball is constant, and for theory, these 5 eyeballs are just It is 5 points on a sphere, actual measurement sphere (such as Fig. 4) can be obtained by software matching, the most just obtain The coordinate of the actual measurement centre of sphere, the coordinate figure of this centre of sphere is exactly the coordinate figure of groove test point.

6. i.e. can get groove test point coordinate figure (eyeball necessary >=5) by above step, this coordinate points again with Nearest theoretical value compares and obtains scribe line position degree actual deviation L.

(a, b, c) be central coordinate of circle after matching to some o, and some O (A, B, C) is theoretical measurement point coordinates (n >=5).

The formula of least square fitting sphere is as follows, and wherein s represents calculating sample variance.

$s^2=\frac{{\mathrm{\Σ}}_{i=1}^n{(R_i-\stackrel{\‾}{R})}^2}{n-1}$

$\left(\begin{array}{c}\sqrt{{\mathrm{\ΔX}}_1^2+{\mathrm{\ΔY}}_1^2+{\mathrm{\ΔZ}}_1^2}=R_1\\ .\\ .\\ .\\ .\\ .\\ .\\ .\\ .\\ .\\ \sqrt{{\mathrm{\ΔX}}_n^2+{\mathrm{\ΔY}}_n^2+{\mathrm{\ΔZ}}_n^2}=R_n\end{array}\right.$

$\left(\begin{array}{c}\mathrm{\Δ}{X}_n=X_n-a\\ \mathrm{\Δ}{Y}_n=Y_n-b\\ \mathrm{\Δ}{Z}_n=Z_n-c\end{array}\right)$

Deviation

Accuracy of detection: the accuracy of detection of the present invention mainly by the precision of laser tracker, the accuracy of manufacture of aid and The error of fitting precision composition that manual measurement brings.If getting rid of the interference factor of external environment, tool operation, span 10 meters is long Mould, its groove accuracy of detection can reach ± 0.09mm, can meet large mold scribe line position required precision.

1. laser tracker certainty of measurement: depend on following Individual accuracy: angular surveying, reflecting mirror, measurement distance.

A. angular surveying: as a example by Leica laser tracker, coded circle is the glass being carved with 18000 interval division lines Glass disk, uses photoelectrically balanced potentiometer scanning, and angular resolution reaches 0.14 ".

B. reflecting mirror precision.

2. detection instrument precision: affect accuracy of detection because have axiality and Aperture deviation, meet under drawing requirement, its Largest cumulative error precision is 0.005+0.009=0.014mm (± 0.007mm).

3. fitting precision (by analysis verification): owing to fit sphere needs multiple eyeballs to complete, the essence after matching The error that degree depends entirely on the repeatability precision of measurement and manual measurement fit sphere brings, can be by analyzing ball after matching After the sphericity in face and matching, the radius of sphere judges quality.

Example: the object ball radius of matching is 55mm, owing to actual spot of measurement exists error, after causing matching, spherical radius is 55.002mm, maximum eyeball deviation fit sphere is 0.0163mm, and minimum deflection is-0.0016m, therefore sphericity is 0.0163+ , there is less deviation in 0.0016=0.0179mm.

Compared with prior art, the invention has the beneficial effects as follows that realization can meet large mold (more than 10 meters) graduating accuracy The digitizing detection method required.

More than have revealed that technology contents and the technical characterstic of the specific embodiment of the present invention, it being understood, however, that at this Under bright creative ideas, those skilled in the art can be to various features disclosed above and the feature not being explicitly illustrated at this Combination make various changes and improve, but broadly fall into protection scope of the present invention.The description of above-described embodiment be exemplary and Not being restrictive, protection scope of the present invention is determined by claim.

Claims (3)

1. a digital measuring has the method for scribe line position degree of mould of curved surface, it is characterised in that described method uses Laser tracker and supplemental measurement tool, described laser tracker includes reflection sphere and supports the reflection sphere pedestal of reflection sphere, institute State supplemental measurement tool and include having cuspidated first end and there is the second end of the central recess accommodating described reflection sphere pedestal, It is characterized in that, described method includes step:

(1) use described laser tracker to set up the spherical coordinate system of groove of mould, determine the theoretical seat of the centre of sphere of spherical coordinate system Scale value；

(2) by the groove of the most advanced and sophisticated alignment mould of described supplemental measurement tool, the second of described supplemental measurement tool is then rotated End, obtains at least 5 different coordinate figures measuring point by reflection sphere；

(3) obtain surveying sphere by software matching, calculate the coordinate figure of the centre of sphere of actual measurement sphere；And

(4) coordinate figure of the centre of sphere of calculating is compared with the theoretical coordinate value of the centre of sphere, obtain the actual deviation of scribe line position degree.

Digital measuring the most according to claim 1 has the method for the scribe line position degree of the mould of curved surface, and its feature exists In, described laser tracker is Leica laser tracker.

Digital measuring the most according to claim 1 has the method for the scribe line position degree of the mould of curved surface, and its feature exists In, some o (a, b, c) be the sphere centre coordinate after matching, and some O (A, B, C) be theory sphere centre coordinate, and its large deviations is:

$L=\sqrt{{(A-a)}^2+{(B-b)}^2+{(C-c)}^2}.$