CN103302162A - Mould positioning method based on feature distance - Google Patents

Abstract

The invention discloses a mould positioning method based on a feature distance. The method comprises the following five steps: 1, initially putting a mould, namely (1) putting a cushion block and (2) putting the mould; 2, moving equipment, namely (1) determining a coordinate, (2) reversing the equipment and (3) driving the equipment; 3, measuring and calculating, namely (1) measuring the distance and (2) geometrically calculating; 4, carrying out positioning calculation on the mould; and 5, correcting a digital control code for stretch forming. According to the method, the equipment is driven to move by motion parameters of a clamp position reversing stretch-forming machine according to equipment features of a ACB FET series digital control horizontal drawing machine, the coordinate and the space position of a mould feature point are calculated by the distance between a clamp feature point and the mould feature point, and the digital control code for the stretch forming is redesigned according to a mould position, thereby achieving accurate skin stretch forming; and due to a mould putting process in the method, the mould putting error redundancy can be increased, the mould putting time can be shortened, the use of a positioning tool can be reduced, and the production efficiency of aircraft skin stretch forming can be improved.

Description

A kind of mould localization method based on characteristic distance

(1) technical field

The present invention relates to a kind of aircraft skin part and in the stretch forming process, determine the localization method of die layout position.Be particularly related to the numerical control stretch former of use ACB FET series at the localization method that carries out cross directional stretch shaping front mold putting position.Belong to space shuttle manufacturing technology field.

(2) background technology

Skin part is the appearance part that consists of and keep Aerodynamic Configuration of Aireraft.Stretch forming (being called for short pull-shaped) is a kind of process that the coating shaping of mould is arranged, and is one of main forming mode of aircraft skin class part forming.Pull-shapedly by the equipment clamp both sides of woolen cloth are clamped, utilize the motion of mould and clamp, make woollenly to produce inhomogeneous stretcher strain and coating mould makes and woollenly fits with mould.

Pull-shaped technological parameter mainly contains woollen percentage elongation and the coating angle of clamp, by the true form of technological parameter and pull-shaped mould, calculates the movement locus (such as Fig. 1) of clamp.ACB FET series numerical controlled stretch forming machine is the horizontal stretching machine, stretching former that French ACB GEC ALSTHOM company produces, and the structural similarity of this series stretching machine, stretching former is divided into FET400, FET600, FET1200 etc. according to tonnage.It is pull-shaped that employing numerical controlled stretch forming machine carries out covering, utilizes equipment to the accurate control of clamp movement locus, realizes accurate forming process.The size of the pull-shaped mould of aircraft skin is from tens centimetres to tens meters, and the pull-shaped mold weight of large-scale skin part also reaches hundred tons.Install for large-scale pull-shaped mould, normally hang with row mould is sling, assisted simultaneously by many people again mould is installed to pull-shaped equipment assigned address produces.Mould will be placed into the position that sets in advance usually needs repeatedly to place and finely tune, and install also often to continue a few hours, and also there is relatively large deviation in final putting position.The uncertainty of die layout position becomes the uncertain factor that affects the covering forming quality, thereby affects the pull-shaped forming accuracy of covering.Therefore need a kind of method of quick jig to come the actual putting position of jig, and for die layout position at that time, revise technological parameter and numerical control code, the clamp movement locus is tallied with the actual situation, make Stretch Forming Process more accurate, guarantee the part forming quality.

(3) summary of the invention

1, purpose:

The purpose of this invention is to provide a kind of mould localization method based on characteristic distance.The method is according to the numerical controlled stretch forming equipment characteristic, utilize the accurate coordinates of characteristic point on the clamp, measure with mould on the relative distance of characteristic point, determine the site error of die layout, equipment processing numerical control code is revised, improved the accuracy of shaping and the quality of part.

2, technical scheme:

A kind of mould localization method based on characteristic distance of the present invention, its step is as follows:

Step 1: mould is initially put

Initially putting of skin part stretch forming mold is that actual mould is placed in the coordinate system of pull-shaped equipment, is the preparation of carrying out mould location survey and Stretch Forming Process, as shown in Figure 2;

In the actual production process of factory, die layout together is placed in the coordinate system of pull-shaped equipment with cushion block on the standard cushion block.The standard cushion block is the homemade standard component of factory, distinguishes by the mold weight that height and cushion block can hold.Mould is initially put at first according to the pull-shaped die boundary dimensions of covering and quality, choice criteria cushion block; Then put cushion block and mould according to the factory technics rules, measure cushion block end face levelness, guarantee cushion block placement level.Record cushion block height H and mold feature point are apart from mould bottom surface height h.

Step 2: sports equipment

Sports equipment is that the equipment clamp with ACB FET series transverse stretching machine moves to assigned address, and it is in the same level that clamp characteristic point and mold feature point is in, and is convenient to range measurement.

(1) determines coordinate

Determine the coordinate position at clamp characteristic point place when measuring, by the height of cushion block and the mold feature point distance apart from the mould bottom surface, determine the height (Z coordinate) of mold feature point place horizontal plane; By appearance and size and the theoretical locus of putting of mould, determine the position (X coordinate) of clamp characteristic point on X-axis; According to the position of clamp characteristic point on clamp, can obtain the Y coordinate of clamp characteristic point, as shown in Figure 3;

(2) equipment is counter separates

The anti-solution of motion of ACB FET series transverse stretching machine is the coordinate position by the clamp characteristic point, solves the length of each pressurized strut on the parallel institution according to the mechanical feature of pull-shaped equipment, i.e. the kinematic parameter of equipment.The machine drawing of ACB FET series digital control horizontal is mainly used in that the aircraft skin part is horizontal to pull into shape, and the profile of stretching machine, stretching former as shown in Figure 4; This equipment is the left-right symmetry structure, a friction clamp mouth of every side clamp, and two horizontal pressurized struts, two vertical pressurized struts form two pairs of four bar parallel institutions, and schematic diagram of mechanism is as shown in Figure 5; The locus of clamp and attitude are determined jointly by the elongation of four pressurized struts; Position when measuring, in order to simplify the anti-computational process of separating of motion, set the clamp axis parallel with Y-axis, therefore only need to calculate the position of clamp in the ZX plane, namely only need to calculate the elongation of Z pressurized strut and A pressurized strut, as shown in Figure 6;

(3) driving arrangement

The elongation of each pressurized strut of stretching machine, stretching former that the anti-solution of ACB FET series transverse stretching machine is obtained, the interface driving arrangement motion of input digital control horizontal machine drawing control system makes clamp move to assigned address, is used for carrying out range measurement.

Step 3: measure and calculate

Measuring process is to measure each characteristic point of clamp to the distance of each characteristic point of mould, then calculates through how much, obtains the coordinate of characteristic point.

(1) range measurement

(X is a negative side), two characteristic points of right side (X is a positive side) two clamps difference marks are designated as P in the left side _L1, P _L2And P _R1, P _R2Two characteristic points of mark are designated as T on mould _LAnd T _RMeasure respectively P _L1, P _L2To T _LDistance and P _R1, P _R2To T _RDistance, as shown in Figure 7.Because common measuring method, such as tape measure, long rope etc., error is larger, takes more high-precision measurement means to measure, and such as three-coordinates measuring machine, laser tracker etc., can improve the mould positioning accuracy;

(2) calculate for how much

After step 2 driving arrangement motion, characteristic point and mold feature point is in the horizontal plane of sustained height on the clamp, so the mould location Calculation can utilize the method for solving of plane geometry, the coordinate of calculating mold feature point, as shown in Figure 8.

Found out by Fig. 8, take in the left side as example, mold feature point T _LConcrete coordinate can be by with P _L1Be the center of circle, L _L1For the circle of radius and with P _L2Be the center of circle, L _L2Determine for the intersection point of the circle of radius, in like manner can determine right side mold feature point T _RConcrete coordinate.

Step 4: mould location Calculation

The concrete coordinate of the mold feature point that calculates by measurement compares calculating with mold feature point theoretical coordinate, draws translation vector and rotational angle in the die top cushion block holding plane, as shown in Figure 9.

Step 5: revise numerical control code and carry out pull-shaped

Transformation parameter by step 4 calculates transforms to the actual mould putting position with theoretical mould, and take new die location as benchmark, the technique for applying parameter generates the equipment numerical control code that conforms to the actual mould position.With the horizontal stretching machine, stretching former of pull-shaped equipment numerical control code input ACB FET, stretching machine, stretching former is carried out no-load running, whether the checkout facility motion conforms to designed technological parameter.Check errorless after, carry out covering pull-shaped.

By above-mentioned five steps, realize the quick location of pull-shaped die space position.Revise the method for pull-shaped track by the mould physical location, allow the stretch forming process of skin part tally with the actual situation, make because the die layout position deviation is able to littlely on the impact of part forming precision, reduced the use of positioning tool, guarantee the precision that the aircraft skin part is produced.

Wherein, the coordinate that passes through the clamp characteristic point described in the step 2 is found the solution the method for equipment moving parameter, utilize the accurate control ability of equipment mechanism characteristics and numerical controlled stretch forming equipment, realized by clamp trace generator numerical control code Stretch Forming Process accurately being controlled.

Wherein, distance is determined the method for mold feature point position between the measurement characteristic point described in the step 3, by simple measurement and how much calculating, realizes the die space location positioning.The method is simple and practical, is convenient to implement.

3, advantage and effect:

The present invention is based on the pull-shaped mould localization method of a kind of aircraft skin of numerical controlled stretch forming equipment, the characteristics according to the numerical controlled stretch forming machine, obtain the coordinate of clamp characteristic point by the kinematic parameter of stretching machine, stretching former, measure the distance of clamp characteristic point and mold feature point, the coordinate that calculates mold feature point is revised the die layout position, according to revised die location, redesign pull-shaped numerical control code by technological parameter again, to realize accurate skin stretch forming.This method has been formulated the die layout flow process in the pull-shaped production process of aircraft skin, has increased the error redundancy of die layout, reduces the use of die layout time and positioning tool, has improved the pull-shaped production efficiency of aircraft skin; And by measuring die location is revised, make numerical control code more meet present case, can improve the forming quality of skin part, the rate of reducing the number of rejects and seconds makes that covering is laterally pull-shaped to be easier to realize digital production.

(4) description of drawings

The pull-shaped loading procedure sketch of Fig. 1 covering

Fig. 2 mould is placed schematic diagram

Fig. 3 clamp movement position schematic diagram

Fig. 4 ACB FET series digital control horizontal machine drawing profile schematic diagram

Fig. 5 ACB FET equipment one side schematic diagram of mechanism

The anti-schematic diagram of separating of Fig. 6 ACB FET equipment

Fig. 7 characteristic point position and dimensional measurement schematic diagram

Fig. 8 mould location feature point position calculation schematic diagram

Fig. 9 mould location transformation calculations schematic diagram

Figure 10 the method for the invention flow chart

Symbol description is as follows among the figure:

O: device coordinate system initial point X: device coordinate system X-axis Y: device coordinate system Y-axis Z: device coordinate system Z axis T _L: mould left feature point (X negative direction one side) T _R: mould right feature point (X positive direction one side) h: mold feature is put mould bottom surface distance H: cushion block height P _L: left side clamp characteristic point (X negative direction one side) P _R: right side clamp characteristic point (X positive direction one side) W: die width D: clamp and mold interval A ₀: A ₀Artis A _I: A _IArtis Y ₀: Y ₀Artis Y _I: Y _IArtis Z ₀: Z ₀Artis Z _I: Z _IArtis Z _II: Z _IIArtis X ₀: X ₀Artis X _I: X _IArtis X _II: X _IIArtis O _ZA: pressurized strut Z, A plane and grip finger intersection point O _XY: pressurized strut X, Y plane and grip finger intersection point P _L1: left side clamp characteristic point 1P _L2: left side clamp characteristic point 2P _R1: right side clamp characteristic point 1P _R2: right side clamp characteristic point 2 Dong: equipment angle ∠ O _ZAA ₁A _Oβ: equipment angle ∠ O _ZAA ₁Z ₁θ: equipment angle ∠ A _OO _ZAA ₁

: mould left feature point theoretical position

: mould right feature point theoretical position TO: mold feature point line mid point

: mold feature point line mid point theoretical position

(5) specific embodiment

Such as Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, shown in Figure 10, based on the mould localization method of characteristic distance, the implementation step of the method is as follows:

Step 1: mould is initially put

The skin part stretch forming mold is initially put signal as shown in Figure 2, and the process of putting can be divided into sequentially places cushion block and place mould.

1, places cushion block

Cushion block is the homemade standard component of factory, divides according to height and the weight that can bear, and its height and top planes satisfy the required precision of process program.At first determine the cushion block model according to die boundary dimensions, quality and pull-shaped track, select cushion block.When placing cushion block, according to technological procedure cushion block is placed on the assigned address of pull-shaped equipment, makes the YZ plane parallel of symmetrical plane and the device coordinate of cushion block.After placement is finished, measure the levelness of cushion block top planes, guarantee cushion block end face level.The height H of record cushion block.

2, place mould

Place before the mould, at first the Measurement die characteristic point is apart from the height h of mould bottom surface, and checks characteristic point position, compare with the theoretical digital-to-analogue of mould, guarantee that actual mould is consistent with digital-to-analogue, prevent that mould from changing because of other reason, change not such as mould remodeling, mold stiffness etc.Then mould is placed on the cushion block, make the coordinate center that is placed on pull-shaped equipment of mould, and the mold feature plane is as far as possible parallel with the coordinate plane of equipment as far as possible.After putting mould and finishing, Measurement die bottom surface height and mould bottom surface levelness guarantee that mold height and levelness meet the requirements.

Step 2: sports equipment

Sports equipment is that the equipment clamp with ACB FET series transverse stretching machine moves to assigned address, and it is in the same level that clamp characteristic point and mold feature point is in, and is convenient to range measurement.At first determine stretching machine, stretching former clamp position coordinate, then according to the anti-stretching machine, stretching former kinematic parameter that solves of clamp position, drive again the stretching machine, stretching former motion clamp is moved to assigned address.

1, determines coordinate

According to the signal of Fig. 3, determine the required coordinate position that moves to of left and right sides clamp characteristic point.If the characteristic point of left and right sides clamp is respectively By the surveying record of step 1, the Z coordinate of clamp characteristic point is that cushion block height and mold feature point are apart from mould bottom surface height sum, that is: as can be known

${Z_P}_L={Z_P}_L=H+h---\left(1\right)$

If die width is W, suppose that mould is to put between two parties, clamp position is D apart from mould two lateral extents, namely has:

${x_P}_L=-(\frac{W}{2}+D),{X_P}_R=(\frac{W}{2}+D)---\left(2\right)$

Obtained the coordinate of clamp characteristic point by formula (1), (2).

2, equipment is counter separates

To calculate and measure in order to simplify, when making range measurement the attitude of clamp for parallel with Y-axis, as shown in Figure 5, i.e. P _L1, O _ZA, O _XY, P _L2X identical with the y coordinate, pressurized strut Z is identical with the X elongation, pressurized strut A is identical with the Y elongation.

Carry out that equipment is counter separates that to calculate be according to known O _ZAPoint coordinates calculates the elongation that equipment is made cylinder, is that X negative direction one side is as example, as shown in Figure 6 take the equipment left side.Analysis institution's sketch, find out:

(1) known O _ZA, A ₀And Z ₀Coordinate.

(2) A _IWith O _ZADistance be a constant S _A, A _IWith Z _IDistance be a constant S _Z

(3) A _IThe joint is coaxial connection, and namely ∠ α and ∠ β immobilize.

At first calculate the elongation of making cylinder A, at △ A ₀A ₁O _ZAMiddle application sine is as follows:

${\∠O}_{\mathrm{ZA}}{A}_0{A}_1={\sin }^{-1}\left(\frac{{|O}_{\mathrm{ZA}}{A}_1|}{{|}_{A0}{O}_{\mathrm{ZA}}|}\sin \mathrm{\α}\right)---\left(3\right)$

$\∠\mathrm{\θ}=\mathrm{\π}\∠\mathrm{\α}-{\∠O}_{\mathrm{ZA}}{A}_0{A}_1---\left(4\right)$

Obtained the value of ∠ θ in the equipment mechanism by formula (3), (4).

By vector

The ∠ θ that turns clockwise can get vectorial

Direction, S again _ABe vector

Length, determine vector

Can obtain an A _ICoordinate.Specifically be calculated as follows:

$\stackrel{\&RightArrow;}{O_{\mathrm{ZA}}{A}_1}=\left[\begin{array}{cc}\cos \mathrm{\&theta;}& \sin \mathrm{\&theta;}\\ -\sin \mathrm{\&theta;}& \cos \mathrm{\&theta;}\end{array}\right]\frac{\stackrel{\&RightArrow;}{{\mathrm{<figure-callout\; id="0"\; label="O\; ZA\; A"\; filenames="HDA00003347509500051.png"\; state="\{\{state\}\}">O</figure-callout>}}_{\mathrm{ZA}}{A}_{}{}_0}}{\left|{\mathrm{<figure-callout\; id="0"\; label="O\; ZA\; A"\; filenames="HDA00003347509500051.png"\; state="\{\{state\}\}">O</figure-callout>}}_{\mathrm{ZA}}{A}_{}{}_0\right|}{S}_A---\left(5\right)$

$\stackrel{\&RightArrow;}{A_1}=\stackrel{\&RightArrow;}{O_{\mathrm{ZA}}}+\stackrel{\&RightArrow;}{O_{\mathrm{ZA}}{A}_1}---\left(6\right)$

In like manner, calculate Z _ICoordinate, as follows:

$\stackrel{\&RightArrow;}{A_1{Z}_1}=\left[\begin{array}{cc}\cos \mathrm{\&beta;}& -\sin \mathrm{\&beta;}\\ \sin \mathrm{\&beta;}& \cos \mathrm{\&beta;}\end{array}\right]\frac{\stackrel{\&RightArrow;}{A_1{O}_{\mathrm{ZA}}}}{S_A}{S}_Z---\left(7\right)$

$\stackrel{\&RightArrow;}{Z_1}=\stackrel{\&RightArrow;}{A_1}+\stackrel{\&RightArrow;}{A_1{Z}_1}---\left(8\right)$

Calculate equipment mechanism artis A by formula (5), (6), (7), (8) _IAnd Z _ICoordinate.

By the symmetry of equipment, in like manner solve the body joint point coordinate of equipment opposite side.So far all body joint point coordinate of ACB FET equipment are found the solution, finish that mechanism is counter to separate.Making the cylinder elongation can be calculated by the difference of artis to the distance of the pressurized strut hinge support length during with the pressurized strut zero-bit.

3, driving arrangement

To calculate each pressurized strut elongation input ACB FET stretching machine, stretching former control panel of ACB FET series transverse stretching machine, the driving arrangement motion makes clamp move to assigned address, and clamp position is checked, determines to coincide with the Theoretical Design position.

Step 3: measure and calculate

1, range measurement

After checking that clamp and die location are errorless, measure the distance of clamp characteristic point and mold feature point, as shown in Figure 7.According to directions X mould and clamp being divided into the left side is that X negative direction one side and right side are X positive direction one side.Measure respectively two characteristic point P of left side clamp _L1, P _L2Characteristic point T to mould left side one end _LTwo characteristic point P of distance and right side clamp _R1, P _R2Characteristic point T to mould right side one end _RDistance, and will record measuring distance.

2, calculate for how much

As shown in Figure 8, according to the coordinate of known clamp characteristic point and the distance that measures, calculate the coordinate of mold feature point, computational methods are as follows:

Mould left feature point $T_L{({x_T}_L,{y_T}_L,{Z_T}_L)}^T:$

With $P_{L1}{({x_P}_{L1},{y_P}_{L1},{Z_P}_{L1})}^T$ Be the center of circle, L _L1For the equation of the circle of radius is

${(T_L-P_{L1})}^T(T_L-P_{L1})={L_{L1}}^2---\left(9\right)$

With $P_{L2}{({X_P}_{L2},{y_P}_{L2},{Z_P}_{L2})}^T$ Be the center of circle, L _L1For the equation of the circle of radius is

Owing to putting P _L1, P _L2, T _LBe in the sustained height plane, that is:

${Z_T}_L={Z_P}_{L1}={Z_P}_{L2}---\left(11\right)$

Simultaneous equations obtain about point

Two solutions, get

Larger solution is true solution, i.e. the solution of mould left feature point.

In like manner solve the solution of mould right feature point $T_R{({x_T}_R,{y_T}_R,{Z_T}_R)}^T.$

Step 4: mould location Calculation

Obtain the mold feature point coordinates by previous step $T_L{({X_T}_L,{y_T}_L,{Z_T}_L)}^T$ With $T_R{({x_T}_R,{y_T}_R,{Z_T}_R)}^T,$ Compare by the theoretical value with mold feature point, calculate theoretical die location to the transformation relation between the actual mould position, as shown in Figure 9.Die location conversion planar is by a translation and rotation transformation realization, and transformation parameter is calculated as follows:

T _LWith T _RLine mid point T _OCoordinate:

${({x_T}_O,{y_T}_O,{Z_T}_O)}^T=[{({x_T}_L,{y_T}_L,{Z_T}_L)}^T+{({x_T}_R,{y_T}_R,{Z_T}_R)}^T]/2$

With

The line mid point

Coordinate:

${({x_T^0}_O,{y_T^0}_O,{Z_T^0}_O)}^T=[{({x_T^0}_L,{y_T^0}_L,{Z_T^0}_L)}^T+{({x_T^0}_R,{y_T^0}_R,{Z_T^0}_R)}^T]/2$

Translation vector

$\stackrel{\&RightArrow;}{T}=\stackrel{\&RightArrow;}{T_O{T}_{\mathrm{<figure-callout\; id="0"\; label="O"\; filenames="HDA00003347509500051.png"\; state="\{\{state\}\}">O</figure-callout>}}^0}---\left(14\right)$

Anglec of rotation θ:

$\mathrm{\&theta;}={\cos }^{-1}\left(\frac{\stackrel{\&RightArrow;}{T_L{T}_R.}\stackrel{\&RightArrow;}{T_L^O{T}_R^O}}{|\stackrel{\&RightArrow;}{T_L{T}_R|}*|\stackrel{\&RightArrow;}{T_L^O{T}_R^O}|}\right)---\left(15\right)$

The rotating shaft vector

$\stackrel{\&RightArrow;}{R}=\stackrel{\&RightArrow;}{T_L^O{T}_R^O}\&times;\stackrel{\&RightArrow;}{T_L{T}_R}---\left(16\right)$

Step 5: revise numerical control code and carry out pull-shaped

Transformation parameter by previous step calculates transforms to the actual mould putting position with theoretical mould, and take new die location as benchmark, the technique for applying parameter generates the equipment numerical control code that conforms to the actual mould position.With the horizontal stretching machine, stretching former of pull-shaped equipment numerical control code input ACB FET, stretching machine, stretching former is carried out no-load running, whether the checkout facility motion conforms to designed technological parameter.Check errorless after, carry out covering pull-shaped.

Claims (3)

1. mould localization method based on characteristic distance, its step is as follows:

Step 1: mould is initially put

Initially putting of skin part stretch forming mold is that actual mould is placed in the coordinate system of pull-shaped equipment, is the preparation of carrying out mould location survey and Stretch Forming Process;

Die layout together is placed in the coordinate system of pull-shaped equipment with cushion block on the standard cushion block, and the standard cushion block is the homemade standard component of factory, distinguishes by the mold weight that height and cushion block can hold; Mould is initially put at first according to the pull-shaped die boundary dimensions of covering and quality, choice criteria cushion block; Then put cushion block and mould according to the factory technics rules, measure cushion block end face levelness, guarantee cushion block placement level, record cushion block height H and mold feature point are apart from mould bottom surface height h;

Step 2: sports equipment

Sports equipment is that the equipment clamp with ACB FET series transverse stretching machine moves to assigned address, and it is in the same level that clamp characteristic point and mold feature point is in, and is convenient to range measurement;

(1) determines coordinate

Determine the coordinate position at clamp characteristic point place when measuring, by the height of cushion block and the mold feature point distance apart from the mould bottom surface, the height of determining mold feature point place horizontal plane is the Z coordinate; By appearance and size and the theoretical locus of putting of mould, determine that the position of clamp characteristic point on X-axis is the X coordinate; According to the position of clamp characteristic point on clamp, can obtain the Y coordinate of clamp characteristic point;

(2) equipment is counter separates

The anti-solution of motion of ACB FET series transverse stretching machine is the coordinate position by the clamp characteristic point, solves the length of each pressurized strut on the parallel institution according to the mechanical feature of pull-shaped equipment, i.e. the kinematic parameter of equipment; The machine drawing of ACBFET series digital control horizontal is used for that the aircraft skin part is horizontal to pull into shape; This equipment is the left-right symmetry structure, a friction clamp mouth of every side clamp, and two horizontal pressurized struts, two vertical pressurized struts form two pairs of four bar parallel institutions; The locus of clamp and attitude are determined jointly by the elongation of four pressurized struts; Position when measuring, in order to simplify the anti-computational process of separating of motion, set the clamp axis parallel with Y-axis, therefore only need to calculate the position of clamp in the ZX plane, namely only need to calculate the elongation of Z pressurized strut and A pressurized strut;

(3) driving arrangement

The elongation of each pressurized strut of stretching machine, stretching former that the anti-solution of ACB FET series transverse stretching machine is obtained, the interface driving arrangement motion of input digital control horizontal machine drawing control system makes clamp move to assigned address, is used for carrying out range measurement;

Step 3: measure and calculate

Measuring process is to measure each characteristic point of clamp to the distance of each characteristic point of mould, then calculates through how much, obtains the coordinate of characteristic point;

(1) range measurement

In the left side, two clamps in right side, two characteristic points of mark respectively, be designated as P _L1, P _L2And P _R1, P _R2; Two characteristic points of mark are designated as T on mould _LAnd T _R; Measure respectively P _L1, P _L2To T _LDistance and P _R1, P _R2; To T _RDistance;

(2) calculate for how much

After the motion of step 2 driving arrangement, characteristic point and mold feature point is in the horizontal plane of sustained height on the clamp, so the mould location Calculation can be utilized the method for solving of plane geometry, the coordinate of calculating mold feature point;

Take in the left side as example, mold feature point T _LConcrete coordinate can be by with P _L1Be the center of circle, L _L1For the circle of radius and with P _L2Be the center of circle, L _L2Determine for the intersection point of the circle of radius, in like manner can determine right side mold feature point T _RConcrete coordinate;

Step 4: mould location Calculation

The concrete coordinate of the mold feature point that calculates by measurement compares calculating with mold feature point theoretical coordinate, draws translation vector and rotational angle in the die top cushion block holding plane;

Step 5: revise numerical control code and carry out pull-shaped

The transformation parameter that is calculated by step 4, theoretical mould is transformed to the actual mould putting position, take new die location as benchmark, the technique for applying parameter generates the equipment numerical control code that conforms to the actual mould position, with the horizontal stretching machine, stretching former of pull-shaped equipment numerical control code input ACB FET, stretching machine, stretching former is carried out no-load running, whether the checkout facility motion conforms to designed technological parameter, check errorless after, carry out covering pull-shaped;

By above-mentioned five steps, realize the quick location of pull-shaped die space position, revise the method for pull-shaped track by the mould physical location, allow the stretch forming process of skin part tally with the actual situation, make and be able to little on the impact of part forming precision because of the die layout position deviation, reduce the use of positioning tool, guaranteed the precision that the aircraft skin part is produced.

2. a kind of mould localization method based on characteristic distance according to claim 1, it is characterized in that: the method for finding the solution the equipment moving parameter at the coordinate that passes through the clamp characteristic point described in the step 2, utilize the accurate control ability of equipment mechanism characteristics and numerical controlled stretch forming equipment, realized by clamp trace generator numerical control code Stretch Forming Process accurately being controlled.

3. a kind of mould localization method based on characteristic distance according to claim 1, it is characterized in that: distance is determined the method for mold feature point position between the measurement characteristic point described in the step 3, by simple measurement and how much calculating, realize the die space location positioning, the method is simple and practical, is convenient to implement.

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